Patent Publication Number: US-2019168976-A1

Title: Multistage conveyance method, multistage conveyance apparatus, and multistage press apparatus for sheet materials to be treated

Description:
FIELD OF THE INVENTION 
     The indention relates to a multistage conveyance method, a multistage conveyance apparatus, and a multistage press apparatus for a sheet material to be treated. 
     DESCRIPTION OF THE RELATED ART 
     A horizontal multistage press of a type in which a plurality of veneer sheets in a standing state with their fiber directions aligned in the vertical direction are lifted upward with respect to a heating plate (hot plate) to be carried in and out is known (see, for example, Patent Document 1 below). 
     CITATION LIST 
     Patent Document 
     [Patent Document 1] Japanese Patent No. 5590928 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the horizontal multistage press described in the above Patent Document 1, there are problems that there is a need to provide a large space and a large-scale lifting mechanism above the hot plate, the horizontal multistage press is increased in size as a whole, and a large driving force is needed to carry veneer sheets between hot plates. 
     An object of the invention is to provide a multistage conveyance apparatus., a multistage press apparatus, and a multistage conveyance method for a sheet material to be treated in which there is no need to provide a large space or a large-scale lifting mechanism above the hot plate for conveying the sheet material to be treated typified by a veneer sheet, and further, the driving force for carrying in the sheet material, to be treated can also be small. 
     Means for Solving the Problem and Effects of the Invention 
     In order to solve the above problems, the multistage conveyance for a sheet material to be treated in the invention includes: 
     a multistage conveyance method for a sheet material to be treated, the multistage conveyance method for: 
     carrying out while holding in parallel along a conveying direction a plurality of sheet materials to be treated held in a standing state in a first treatment step positioned on an upstream side in a conveying direction, and 
     carrying the plurality of sheet materials to be treated in a standing state into a predetermined press position in which a second treatment step of sandwiching and pressurizing each sheet material to be treated from both sides with a contact plate is configured to be performed, the press position positioned on a downstream side in a conveying direction, 
     the multistage conveyance method for a sheet material to be treated including: 
     an upstream side carry-out step of carrying out a sheet material to be treated with an upper part of a sheet material to be treated gripped and suspended after the first treatment step; and 
     a downstream side carry-in step of carrying a sheet material to be treated into a press position of the second treatment step with a gripping position of a sheet material to be treated shifted from an upper part to a lower part and supported. 
     In this case, for example, a back side carry-out step of carrying out the sheet material to be treated to a predetermined standing position for performing a third treatment step capable of unloading the sheet material to be treated to the outside with the lower part of the sheet material to be treated gripped and supported after the second treatment step, and a back side carry-in step of carrying the sheet material to be treated into the standing position of the third treatment step with the gripping position of the sheet material to be treated shifted from the lower part to the upper part, and the upper part gripped and supported can be included. In addition, in order to solve the above problems the multistage conveyance apparatus for a sheet material to be treated in the invention includes: 
     a multistage conveyance apparatus for a sheet material to be treated, the multistage conveyance apparatus for: 
     carrying out while holding in parallel along a conveying direction a plurality of sheet materials to be treated held in a standing state in a first treatment device positioned on an upstream side in a conveying direction, and 
     carrying the plurality of sheet materials to be treated in a standing state into a press position of a second treatment device configured to sandwich and pressurize each sheet material to be treated from both sides with a contact plate, the press position positioned on a downstream side in a conveying direction, 
     the multistage conveyance apparatus for a sheet material to be treated including: 
     an upstream side conveyance body configured to carry out a sheet material to be treated with an upper part of a sheet material to be treated gripped and suspended from the first treatment device; and 
     a downstream side conveyance body configured to carry a sheet material to be treated into a press position of the second treatment device with a gripping position of a sheet material to be treated shifted from an upper part to a lower part and supported. In addition, in order to solve the above problems, the multistage press apparatus for a sheet material to be treated in the invention includes: 
     a multistage press apparatus for a sheet material to be treated including: 
     a preceding conveying device including the upstream side conveyance body and the downstream side conveyance body when the first treatment device is a loader device for loading a plurality of sheet materials to be treated for drying, and the second treatment device is a hot press device for pressurizing and heating by sandwiching from both sides each sheet material to be treated with a first contact plate; and 
     a subsequent conveyance device including the upstream side conveyance body and the downstream side conveyance body when the first treatment device is an open transpiration device for evaporating water vapor from both surfaces of each sheet material to be treated, and the second treatment device is a temperature control press device for pressurizing and temperature-controlling by sandwiching from both sides each sheet material to be treated with a second contact plate. The loader device, the hot press device, the open transpiration device, and the temperature control press device are arranged in this order from an upstream side in a conveying direction. The preceding conveyance device is positioned over the loader device and the hot press device, and the subsequent conveyance device is positioned over the open transpiration device and the temperature control press device. 
     The multistage conveyance method, the multistage conveyance apparatus, and the multistage press apparatus for sheet material to be treated in the invention have a configuration of gripping the upper part of the sheet material to be treated in the standing state and conveying the sheet material to be treated to the middle (first half), and then holding the sheet materiel to be treated with the gripping position shifted to the lower part and performing the second half of the conveyance. Therefore, a large space and a large-scale lifting mechanism above the hot plate are unnecessary for conveying the sheet material to be treated, and the driving force for carrying in the sheet material to be treated can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a main part of a horizontal multistage press apparatus to which the invention is applied. 
         FIG. 2  is a front view of  FIG. 1 . 
         FIG. 3  is a plan view of  FIG. 1 . 
         FIG. 4A  is an enlarged front view of a loader device shown in  FIG. 2 . 
         FIG. 4B  is a schematic diagram showing a modified example of a loader shelf in  FIG. 4A . 
         FIG. 5  is a side view showing a state after the ascent of a loader unit conveyor in  FIG. 4A . 
         FIG. 6  is a plan view of  FIG. 4A . 
         FIG. 7A  is a front view showing an example of a veneer sheet as a sheet material to be treated. 
         FIG. 7B  is an explanatory diagram showing a state in which the veneer sheet in  FIG. 7A  is supported by a roller. 
         FIG. 7C  is a front view showing another example of a veneer sheet as a sheet material to be treated. 
         FIG. 7D  is an explanatory diagram showing a state in which the veneer sheet in  FIG. 7C  is supported by a roller. 
         FIG. 7E  is an explanatory diagram showing a state in which the veneer sheet is supported by a belt conveyor. 
         FIG. 8  is an enlarged front view of a gripping member used in each device in  FIG. 1 . 
         FIG. 9  is a side view of  FIG. 8 . 
         FIG. 10A  is a bottom view of  FIG. 8 . 
         FIG. 10B  is an operation state diagram of  FIG. 10A . 
         FIG. 11  is an enlarged front view of the hot press device shown in  FIG. 2 . 
         FIG. 12  is a side view of  FIG. 11 . 
         FIG. 13A  is an enlarged side view when the hot plate in  FIG. 12  is in an open state in a configuration using a spring member. 
         FIG. 13B  is an enlarged side view when the hot plate in  FIG. 13A  is in a closed state. 
         FIG. 13C  is an enlarged side view when the hot plate in  FIG. 12  is in an open state in a configuration using a link. 
         FIG. 13D  is a cross-sectional view taken along the line XIIID-XIIID in  FIG. 13C . 
         FIG. 13E  is an enlarged side view when the hot plate in  FIG. 13C  is in a closed state. 
         FIG. 14  is a block diagram showing the electrical configuration of the horizontal multistage press apparatus shown in  FIG. 1 . 
         FIG. 15  is a flowchart showing veneer sheet drying treatment executed by the control board in  FIG. 14 . 
         FIG. 16  is a flowchart showing the contents of the initial setting in step S 1  in  FIG. 15 . 
         FIG. 17  is a flowchart showing the contents of the loader step in step S 2  in  FIG. 15 . 
         FIG. 18  is a flowchart shewing the contents of a first conveyance step in step S 3  in  FIG. 15 . 
         FIG. 19  is a flowchart showing the contents of a second conveyance step in step S 5  in  FIG. 15 . 
         FIG. 20  is a flowchart showing the contents of a third conveyance step in step S 7  in  FIG. 15 . 
         FIG. 21  is a flowchart showing the contents of a fourth conveyance step in step S 9  in  FIG. 15 . 
         FIG. 22  is a flowchart showing the contents of an unloader step in stop S 10  in  FIG. 15 . 
         FIG. 23  is a 3D image explanatory diagram corresponding to the contents of the loader treatment in  FIG. 17 . 
         FIGS. 24 to 35  are 3D image explanatory diagrams corresponding to the contents of the first conveyance treatment in  FIG. 18 . 
         FIGS. 36 to 40  are 3D image explanatory diagrams corresponding to the contents of the second conveyance treatment in  FIG. 19 . 
         FIGS. 41 to 47  are 3D image explanatory diagrams corresponding to the contents of the third conveyance treatment in  FIG. 20 . 
         FIGS. 48 to 53  are 3D image explanatory diagrams corresponding to the contents of the fourth conveyance treatment in  FIG. 21 . 
         FIG. 54  is a 3D image explanatory diagram corresponding to the contents of the unloader treatment in  FIG. 22 . 
         FIG. 55  is a front view showing a main part of a horizontal multistage press apparatus according to another example of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the invention will tea described with reference to the drawings. 
     EXAMPLE 1 
       FIGS. 1 to 3  show main parts of a horizontal multistage press apparatus  1  to which a multistage conveyance apparatus and a multistage press apparatus for a sheet material to he treated according to the invention are applied. The horizontal multistage press apparatus  1  has a function of treating to pressurize and dry a rectangular plate-shaped veneer sheet W 1  as a sheet material to be treated (see  FIGS. 7A and 7C ; hereinafter referred to as “veneer sheet W 1 ”). It should be noted that the sheet material to be treated is not limited to a veneer sheet, and for example, a laminated material, plywood, a decorative laminated sheet or the like can be used. 
     The horizontal multistage press apparatus  1  includes: a loader device  10  for loading a plurality of veneer sheets W 1  for drying, a hot press device  20  for sandwiching each veneer sheet W 1  from both sides with a hot plate  24  (first contact plate) to pressurize and heat the corresponding veneer sheet W 1 , an open transpiration device  40  for evaporating water vapor from the surface of each veneer sheet W 1 , a temperature control press device  50  for sandwiching each veneer sheet W 1  from both sides with a temperature control plate  54  (second contact plate) to pressurize, temperature-control, and keep the corresponding veneer sheet W 1  at a desired finished temperature, and an unloader device  60  for unloading a plurality of temperatures-controlled veneer sheets W 1 , in this order from the upstream side in the conveying direction. 
     The loader device  10  functions as a carry-in unit, causes the veneer sheet W 1  to stand from a substantially horizontal state (including inclined range of about ±45° with respect to the horizontal plane), and holds the veneer sheet W 1  in a standing state to carry the veneer sheet W 1  into the hot press device  20 . The hot press device  20  functions as a pressurizing and heating unit, pressurizes and heats the veneer sheet W 1  in the standing state one by one for a predetermined time with the veneer sheet W 1  sandwiched between the hot plates  24  (for example, held for 5 to 10 minutes in a state where the hot plate temperature is 180° C.), and carries the heated and dried veneer sheet W 1  into the open transpiration device  40 . 
     The open transpiration device  10  functions as an open section unit (atmospheric release unit), promotes evaporation of surplus moisture remaining inside the veneer sheet W 1  to the atmosphere (for example, holding for a few minutes in a state where the veneer sheet temperature is 90° C.) while holding each veneer sheet W 1  in a standing state, and carries the evaporated veneer sheet W 1  into the temperature control press device  50 . The temperature control press device  50  functions as a pressurizing and temperature-control unit, pressurizes and temperature-controls the veneer sheet W 1  in the standing state one by one for a predetermined time with the veneer sheet W 1  sandwiched between the temperature control plates  54  (for example, held tor a few minutes in a state where the temperature-control plate temperature is 25 to 35° C.), and carries the temperature-controlled veneer sheet W 1  into the unloader device  60 . 
     The unloader device  60  functions as a carry-out unit, returns the veneer sheet W 1  after the drying treatment to a substantially horizontal state, and carries the veneer sheet W 1  out of the device  60 . In the following, each device will be described in more detail below. It should be noted that in the following description, the left-right direction in  FIG. 2  is defined as the left-right direction in the horizontal multistage press apparatus  1 , the up-down direction in  FIG. 2  is defined as the up-down direction in the horizontal multistage press apparatus  1 , and the front-back direction in  FIG. 2  is defined as the front-back direction in the horizontal multistage press apparatus  1 . 
     First, the loader device  10  will be described. As shown in  FIGS. 4A to 6, 23 , and the like, the loader device  10  includes a lower frame  11  serving as a base and a gate-shaped upper frame  12  erected on the lower frame  11 . The lower frame  11  includes a pair of beams  11   a  extended in the front-back direction and a pair of beams  11   b  extended in the left-right direction. These beams  11   a  and  11   b  are connected in a form intersecting at right angles in a plan view. If should be noted that in  FIG. 23  and the like, some members constituting the loader device  10  are omitted. 
     On the upper part of the beam  11   a,  a chain conveyor  13  is installed. A loader shelf  14  is connected to the chain conveyor  13  via a connecting member  13   a  at predetermined pitches. The loader shelf  14  has a substantially U-shaped plate shape, receives a veneer sheet W 1  from a feed mechanism (not shown) in a substantially horizontal position D 1  (see  FIG. 6 ) on the front side of the loader device  10  along with the rotation of the chain conveyor  13  by the forward rotation drive of the chain conveyor motor  203  (sea  FIG. 14 ) described below, and causes the veneer sheet W 1  to completely stand in the standing position D 2  while supporting and gradually raising the veneer sheet W 1  along with the further forward rotation drive of the chain conveyor  13 . Each veneer sheet W 1  reaching the standing position D 2  is held in the standing state due to contact with the front and rear leader shelves  14 . The number of the veneer sheets W 1  to be accommodated in the standing position D 2  by the loader shelves  14  can be set to, for example, about 10 to 200. 
     The loader unit conveyor  15  is supported by the beam  11   b  so as to be movable up and down along the guide  17  by the conveyor elevating cylinder  16 . The conveyor elevating cylinder  16  is provided on a beam  11   c  built parallel to the beam  11   b  (see  FIG. 4A ). When the loader unit conveyer  15  includes a plurality of rollers  15   a , a plurality of cutouts  14   a  are formed in the base end portion corresponding to the U-shaped bottom side of the loader shelf  14 . Each cutout  14   a  is provided corresponding to the roller  15   a  of the loader unit conveyer  15 . 
     The loader unit conveyor  15  is in the descent position (original position, see  FIG. 4A ) during the forward rotation drive of the chain conveyor  13 , and is in the ascent position (operation position, see  FIG. 5 ) during the drive stop of the chain conveyor  13  and the forward rotation drive of the loader unit conveyor  15 . When the loader unit conveyor  15  is in the ascent position (operation position), the roller  15   a  of the loader unit conveyor  15  is set so that the roller  15   a  is positioned in the corresponding cutout  14   a,  and a conveying surface F 1  (see  FIG. 28 ) horizontally continuous with the conveying surface F 2  of the hot press unit roller conveyor  31  described below is formed. 
     In this state, the roller  15   a  of the loader unit conveyor  15  is at the same height position as the rollers  31   a  to  31   c  (see  FIG. 11 ) of the hot press unit roller conveyor  31  of the hot press device  20  described below, and is made to be carried into the hot press device  20  along with the rotation of the roller  15   a  due to the forward rotation drive of a loader unit conveyor motor  204  described below (see  FIG. 14 ) without each veneer sheet W 1  (indicated by two-dot chain lines in  FIGS. 4A and 5 ) in the standing position D 2  being interfered by the chain conveyor  13 . 
     It should be noted that as shown in  FIG. 4B , if the shape of the cutout  14   a  of the loader shelf  14  is changed to a rectangular cutout  14   b  and the loader unit conveyor  15  is made into a belt conveyor  150  using a belt material having a high friction coefficient, the lower end of the veneer sheet W 1  can be placed on the conveyor more reliably. That is, for example, as in the veneer sheet W 2  shown in  FIG. 7A , as long as the veneer sheet W 2  is obtained by joining plate pieces so that the fiber direction is in a direction orthogonal to the longitudinal direction of the veneer sheet W 2  (width direction), when the veneer sheet W 2  is erected so that its width direction is the up-down direction, even if the veneer sheet W 2  comes into contact with the roller  15   a , it is possible to avoid the lower end thereof from being rounded due to the strength of the veneer sheet itself (see  FIG. 7B ). As a result, the lower end of the veneer sheet W 2  can be reliably placed on the roller  15   a.    
     However, for example, as in the veneer sheet W 3  shown in  FIG. 7C , if the fiber direction is parallel ho the longitudinal direction of the veneer sheet W 3 , when the veneer sheet W 3  comes into contact with the roller  15   a,  the lower end thereof tends to be rounded due to vibrations or the like when the veneer sheet W 3  is sent from the roller  15   a  to the roller  15   a  (see  FIG. 7D ). This tendency to be rounded occurs particularly conspicuously in a veneer sheet in which the fiber direction is parallel to the longitudinal direction of the veneer sheet W 3  or in a wet state before drying, and as a result, it is highly likely that the veneer sheet W 3  is clogged between the rollers  15   a . Thus, changing the roller conveyor to the belt conveyer  150  (see  FIG. 7E ) allows the veneer sheet to be conveyed more reliably regardless of the type and nature of the veneer sheet in which the veneer sheet W 3  is clogged between the rollers  15   a . Therefore, in the loader device  10 , a conveyor for supporting and conveying the lower end of the veneer sheet W 1  may be replaced with the belt conveyor  150  from the rollers  15   a  to be adopted. In this case, in the base end portion corresponding to the U-shaped bottom side of the loader shelf  14 , a rectangular cutout  14   b  in which the belt conveyor  150  can intervene is formed in place of a plurality of cutouts  14   a  (see  FIG. 4B ). 
     The lower frame  11  is provided with a loader unit conveyor  15 , while the upper frame  12  is provided with a loader unit gripping body  70 A. The loader unit gripping body  70 A includes a traveling body  71  supported by laterally extended three beams  12   a  constituting the constituent members of the upper frame  12 , the traveling body  71  movable along the beams  12   a,  a traveling body motor  72  with a speed reducer for driving the traveling body  71 , a gripping member  73  capable of gripping the veneer sheet W 1 , and a pair of gripping member elevating cylinders  74  for supporting and connecting the gripping member  73  so as to be movable up and down with respect to the traveling body  71 . 
     The beams  12   a  each are arranged in parallel with each other at equal intervals. Guide rails  70   a  are laid on the upper surfaces of the beams  12   a  on both sides and a rack gear  70   b  is laid on the upper surface of the middle beam  12   a.  The traveling body  71  is placed on the guide rail  70   a  via the slide guide  71   a , and the traveling body motor  72  is gear-coupled to the rack gear  70   b  via the intermediate drive shaft  72   a  and the pinion gear  72   b . Thus, the traveling body  71  laterally moves along the guide rail  70   a  along with the forward sad reverse drive of the traveling body motor  72 . 
     It should be noted that the drive means of the traveling body  71  is not limited to the one adopting the traveling body motor  72 , and in addition to or instead of thin, for example, a drive system mainly including a fluid cylinder (hydraulic pressure or pneumatic pressure) may be adopted. The drive transmission means of the traveling body  71  is not limited to the one adopting the gear coupling, and in addition to or instead of this, for example, a drive transmission system mainly including a pulley and a timing belt may be adopted. 
     As shown in  FIGS. 4A, 5, 26 , and the like, the gripping member  73  includes a rectangular frame-shaped main body  73   a  arranged so as to extend in the front-back direction on the lower side of the beam  12   a.  A protruding portion  73   a   1  protruding upward is formed or the upper surface of each and portion in the front-back direction of the main body  73   a  and a tip of the piston rod  74   a  of the corresponding gripping member elevating cylinder  74  is connected to each protruding portion  73   a   1 . On the lower surface of the main body  73   a,  three guide rails  73   b ,  73   c,  and  73   b  are arranged in parallel and at equal intervals as shown in  FIGS. 8 to 10A and 10B . 
     On the respective guide rails  73   b  on both sides, outer gripping piece blocks  75  are suspended via the slide guides  73   d,  and on the middle guide rail  73   c,  an inner gripping piece block  76  is suspended via the slide guide  73   e . The outer gripping piece blocks  75  are connected to each other on one and side to form a substantially U shape and the inner gripping piece block  76  is arranged inside the U shape in the outer gripping piece blocks  75 . A tip of the piston rod  77   a  of the gripping piece cylinder  77  is connected to one end portion corresponding to the bottom side of the U shape of the outer gripping piece blocks  73 , and an and of the piston rod  78   a  of the gripping piece cylinder  78  is connected to the and portion of the inner gripping piece block  76  corresponding to the tip side of the U shape of the outer gripping piece blocks  75 . 
     On the lower surfaces of the outer gripping piece block  75  and the inner gripping piece block  76 , a plurality of gripping places  81  and  82  are respectively provided downward in a protruding manner at predetermined intervals (for example, the length about the thickness of the loader shelf  14 ) in the longitudinal direction of the gripping piece block. The gripping pieces  81  and  82  are provided so as to be associated with each veneer sheet W 1  (in  FIG. 10A , a case where ten gripping pieces  81  in all (five on each side) and five gripping pieces  82  are provided is illustrated). The gripping piece  81  is, for example, formed of a resin that can be bent and deformed, and the gripping piece  82  is, for example, formed of a flat spring made of steel. Nonslip portions  81   a  and  82   a  are respectively formed in the tip portions of the gripping pieces  81  and  82  by, for example, rubber adhesion. 
     Along with the drive of the gripping piece cylinders  77  and  78 , the outer gripping piece block  75  and the inner gripping piece block  76  approach and leave each other. Then, when the gripping member  73  approaches the veneer sheet W 1  held in the standing state by the loader shelf  14 , in a state where the outer gripping piece block  75  and the inner gripping piece block  76  ere separated as shown in  FIG. 10A , the gripping pieces  81  and  82  are allowed to freely enter and exit between the respective veneer sheets W 1 . 
     When the gripping piece cylinders  77  and  78  are driven with the gripping pieces  81  and  82  entering between the respective veneer sheets W 1 , as shown in  FIG. 10B , the outer gripping piece block  75  and the inner gripping piece block  76  approach each other, and each veneer sheet W 1  is gripped in the upper position by the sandwiching operation between the pair of gripping pieces  81  approximately side-by-side in the left-right direction and the gripping piece  82  in the middle. It should be noted that not only in the mode of driving both of the gripping piece cylinders  77  and  78  but also in the configuration in which only one of the gripping piece cylinders  77  and  78  is driven, it is possible to grip or release the veneer sheet W 1  in the same manner as described above. 
     Then, with the upper part of the veneer sheet W 1  gripped by the gripping member  73  and the lower part of the veneer sheet W 1  supported by the belt conveyor  150  (roller  15   a ), the gripping member  73  and the loader unit conveyor  15  of the loader unit gripping body  70 A are configured to move in synchronization with the upper and lower parts. 
     In the first example, the loader device  10  corresponds to a first treatment device, the loader unit gripping body  70 A corresponds to an upper part gripping body, and the leader unit, conveyer  15  corresponds to a first conveyance body. In addition, the loader unit gripping body  70 A and the loader unit conveyor  15  correspond to an upstream side conveyance body. 
     Next, the hot press device  20  will be described. As shown in  FIGS. 11, 12, 28 , and the like, the hot press device  20  includes base frames  21 F and  21 B erected as a pair in the front-back direction, and a pair of beams  22 L and  22 R in the left-right direction built at the upper ends of the base frames  21 F and  21 B. Each of the base frames  21 F and  21 B includes a rectangular main body wall portion  21   a  and a pair of leg portions  21   b . Between the main body wall portions  21   a,  a pair of pressing plates  23 F and  23 B in the front-back direction, and multistage hot plates  24  between the pressing plates  23 F and  23 B are arranged. It should be noted that in  FIGS. 11, 28 , and the like, some members constituting the hot press device  20  such as the base frame  21 F and the pressing plate  23 F are omitted. 
     At the lower end of each of the beams  22 L and  22 R, a flange portion  22   a  is formed so as to horizontally protrude in the left-right direction, and rails  22   b  and  22   c  are respectively laid on the outer side and inner side upper surfaces of the flange portion  22   a.  The pressing plates  23 F and  23 B are suspended and supported by the outer rail  22   b  via the bracket  25  including the support roller  25   a,  and each hot plate  24  is suspended and supported by the inner rail  22   c  via the bracket  26  including the support roller  26   a.    
     A plurality of press cylinders  27  (for example, hydraulic cylinders; three press cylinders are illustrated in  FIG. 11 ) are inserted at predetermined intervals in the left-right direction in the central part of the main body wall portion  21   a  of the base frame  21 F, and the tip of the ram  27   a  is attached to the pressing plate  23 F. It should be noted that in the first example, the back side pressing plate  23 B is configured to be fixed to the main body wall portion  21   a  of the base frame  21 B, and only the front side pressing plate  23 F is configured to more in accordance with the expansion and contraction operation of the press cylinder  27 . 
     Between adjacent hot plates  24  and between the hot plates  24  at the front and back ends and the pressing plates  23 F and  23 B, a space regulating member  28  for preventing the spreading not less than a predetermined interval during the press opening is interposed (see FIG.  12 ; specifically, see Japanese Patent No. 4781168, JP S60-259402 A, and the like). In addition, as shown in  FIGS. 13A and 13B , between adjacent hot plates  24 , a spring member  29  is interposed so that adjacent hot plates  24  approach each other by approximately the same distance during the press closing by the pressing plates  23 F and  23 B, and the distance between adjacent hot plates  24  is kept approximately the same while being changed. 
     The spring member  29  interposed between the adjacent not plates  24  allows simultaneous pressing on the veneer sheets W 1  (closing each veneer sheet W 1  simultaneously by pressing the pressing plates  23 F and  23 B) to be performed, prevents the breakage due to pressure concentration on a specific veneer sheet W 1 , and allows the thickness of each veneer sheet W 1  to be satisfactorily made uniform. 
     In addition, instead of the coiled spring member  29 , it is also possible to adopt a configuration using a chain CH as shown in  FIGS. 13C to 13E , for example. In this configuration, a pair of bearings  24   a  is mounted to both sides of the upper part of the hot plate  24  so as to protrude upward at predetermined intervals, and one end portion of a pair of links  124  is interposed between the bearings  24   a  and is pivotally mounted by a fixing pin  125  inserted between the bearings  24   a.  The other and portion of the link  124  is connected by an intermediate pin  126  to the other and portion of the link pivotally mounted at one and to the adjacent hot plate  24 , and each hot plate  24  is connected by a chain CH including a pair of links  124  as a unit body. 
     From the beginning to the and of this chain CH, a linear spring  127  is wound around a pivotally mounting portion by the fixing pin  125  of each link  124  as a unit body and a connecting portion by the intermediate pin  126 , and the connecting portion of each link  124  by the intermediate pin  126  is configured to protrude outward (upward) by substantially the same amount when the front and back hot plates  24  are contracted and closed (see  FIG. 13E ). When the front and back hot plates  24  expand from this state, the connection portion of each link  124  by the intermediate pin  126  descends by substantially the same amount toward the inside (downward), the angle with the intermediate pin  126  as an apex in the triangle formed by the intermediate pin  126  and one and portion of each link  124  changes from an acute angle to an obtuse angle, and each link  124  is configured to be substantially linear when the free and of the space regulating member  28  is locked to the bracket to reach the press opening (see  FIG. 13C ). Even when this chain CH is used, simultaneous pressing on each veneer sheet W 1  becomes possible, breakage due to pressure concentration on a specific veneer sheet W 1  can be prevented, the thickness of each veneer sheet W 1  can be made well uniform. 
     Below the hot plate  24 , a hot press unit roller conveyor  31  for supporting the veneer sheet W 1  in a standing state from the lower side, capable of carrying in the veneer sheet W 1  from the loader device  10  to the hot press device  20 , and furthermore, from the hot press device  20  toward the open transpiration device  40  is arranged. The hot press unit roller conveyor  31  includes a plurality of rollers  31   a  to  31   c  having a roller length over all the veneer sheets W 1  between, the hot plates  24  in order to carry in the veneer sheet W 1  (in  FIG. 11 , a total of 5 rollers are illustrated). 
     It should be noted that in a state where the veneer sheet W 1  is supported by the rollers  31   a  to  31   c  of the hot press unit roller conveyor  31 , the lower part of the veneer sheet W 1  protrudes from the lower end of the hot plate  24  in a suspended state (see  FIGS. 28 and 30 ). The protruding portion of the veneer sheet W 1  is a portion to be gripped by the gripping pieces  81  and  82  of the gripping member  73  of the hot press unit gripping body  70 B described below. Then, since the protruding portion of the veneer sheet W 1  cannot be pressurized and heated by the hot plate  24 , the protruding portion is finally cut off. 
     The rollers  31   a  to  31   c  are arranged at the same height position so as to form a horizontal conveyance surface F 1 , and the rollers  31   b,    31   a,    31   c,    31   a,  and  31   b  are arranged in this order from the left to the right. Of the rollers  31   a  to  31   c,  the rollers  31   a  and  31   b  are of a fixed type, while the roller  31   c  is configured to be able to reciprocate along the conveying direction between the rollers  31   a  adjacent in the left-right direction. 
     Specifically, the roller  31   a  is supported on both main body wall portions  21   a  of the base frames  21 F and  21 B by bearings fixed to the upper surface of the frame-shaped bracket  21   c.  In addition, beams  21   d  are respectively built on the opposing leg portions  21   b  on the left side and the opposing leg portions  21   b  on the right side of the base frames  21   f  and  21 B, and a long plate-shaped bracket  21   e  is erected on the upper surface of each beam  21   d . The roller  31   b  is supported by a bearing fixed to the upper and of the bracket  21   e . The roller  31   c  will be described below. 
     Below the hot press unit roller conveyor  31 , a hot press unit gripping body  70 B is provided. Three beams  21   f  extend in the left-right direction on the upper surfaces of the beams  21   d  arranged on the left and right sides. The hot press unit gripping body  70 B is configured in the same manner as the loader unit gripping body  70 A. Therefore, in the following description, in the hot press unit gripping body  70 B shown in  FIGS. 11, 12, 20 , and the like, the same reference numerals are denoted to the members performing the same functions as the members constituting the loader unit gripping body  70 A and the description will be omitted, and differences from the loader unit gripping body  70 A will be mainly described. 
     The loader unit gripping body  70 A and the hot press unit gripping body  70 B are different in that: due to the difference in the basic structure that the loader unit gripping body  70 A is configured to be capable of gripping the upper part of the veneer sheet W 1 , whereas the hot press unit gripping body  70 B is configured to be capable of gripping the lower part of the veneer sheet W 1 ; in the loader unit gripping body  70 A, the slide guide  73   d  of the gripping member  73  is suspended on the guide rail  73   b,  whereas in the hot press unit gripping body  70 B, the slide guide  73   d  of the gripping member  73  is placed on the guide rail  73   b;  and the loader unit gripping body  70 A is configured not to include rollers contributing to the conveyance of the veneer sheet W 1 , whereas the hot press unit gripping body  70 B is configured to include the roller  31   c  contributing to the conveyance of the veneer sheet W 1 . 
     The roller  31   c  is integrally attached to the traveling body  71  via a long plate-shaped linkage bracket  71   b.  That is, along with the traveling body  71  moving left and right along the guide rail  70   a,  the traveling body  71  and the roller  31   c  synchronously move in the conveying direction (left direction) while holding the veneer sheet W 1  gripped by the gripping member  73  integrally at predetermined intervals. Thus, the roller  31   c  is not a fixed type unlike the rollers  31   a  and  31   b , but functions in the same manner as the rollers  31   a  and  31   b  in that the lower end surface of the veneer sheet W 1  is supported from the lower side, and greatly contributes to stably carrying in the veneer sheet W 1 . 
     It should be noted that in the first example, no driving means for driving the roller  31   c  is provided, but a driving means for the roller  31   c  may be provided and the roller  31   c  may be configured to be driven. Moreover, in addition to or to place of providing the mechanism including the roller  31   c  and the linkage bracket  71   b  on the left side (forward moving aide) of the gripping member  73 , for example, a mechanism having a similar configuration may be provided on the right side (backward moving side) of the conveyance member  73 . 
     In the first example, the hot press device  20  corresponds to a second treatment device, the hot press unit gripping body  70 B corresponds to a lower part gripping body, and the hot press unit roller conveyor  31  corresponds to a second conveyance body. In addition, the hot press unit gripping body  70 B and the hot press unit roller conveyor  31  correspond to a downstream side conveyance body. Furthermore, the traveling body  71 , the linkage bracket  71   b,  and the like of the hot press unit gripping body  70 B correspond to a linkage mechanism, and the roller  31   c  of the hot press unit roller conveyor  31  corresponds to an auxiliary conveyance body. 
     Next, the open transpiration device  40  will be described. As shown in  FIGS. 2, 3, 36, 39 , and the like, the open transpiration device  40  includes a frame  41 . It should be noted that in  FIG. 36, 39 , and the like, a part of members of the open transpiration device  40  is omitted. The frame  41  includes a pair of beams  41   a  extended in the front-back direction and a pair of beams  41   b  extended in the left-right direction. On the upper part of the beam  41   a , a plurality of open shelves  42  are erected in a standing state at the same intervals as those between the hot plates  24  during the opening in the hot press device  20 . The plurality of veneer sheets W 1  are accommodated between the open shelves  42  one by one, and water vapor can be evaporated from both surfaces in a standing state. 
     In the upper part of the beam  41   b,  an open transpiration unit roller conveyor  43  for supporting the veneer sheet W 1  in a standing state from the lower side, capable of carrying in the veneer sheet W 1  from the hot press device  20  to the open transpiration device  40 , and furthermore, from the open transpiration device  40  toward the temperature control press device  50  is arranged. The open transpiration unit roller conveyor  43  includes a plurality of rollers  43   a  having a roller length over all the veneer sheets W 1  between the open shelves  42 . The open transpiration unit roller conveyor  43  has a conveyance surface F 2  at the same height as the hot press unit roller conveyor  31 . 
     Each veneer sheet W 1  is prevented from falling down due to contact with the corresponding open shelf  42 , and each lower end thereof is supported so as to be conveyable by a roller  43   a , and is held in a standing state in the open shelf  42 . It should be noted that in the open transpiration device  40 , since each veneer sheet W 1  only has to be held for only a certain period of tine, unlike the loader unit conveyor  15 , the open transpiration unit roller conveyor  43  is not configured to be capable of going up and down. 
     An open transpiration unit gripping body  70 C is provided above the open shelf  42 . While being supported by the three beams  41   c  extended to the left and right over the beam  22 L of the hot press device  20  and the beam  22 R of the temperature control press device  50 , the open transpiration unit gripping body  70 C is movable along these beams  41   c.  The open transpiration unit gripping body  70 C is configured in the same manner as the loader unit gripping body  70 A. 
     However, as described above, since the open transpiration cult roller conveyor  43  is not configured to be movable up and down, the gripping member elevating cylinder  74  of the open transpiration unit gripping body  70 C is not driven, and only the traveling body motor  72  of the open transpiration unit gripping body  70 C is driven. That is, the open transpiration unit gripping body  70 C moves only in the left-right direction along the beam  41   c . Since the other configuration is the same as that of the loader unit gripping body  70 A, in the open transpiration unit gripping body  70 C shown in  FIGS. 2, 36, 39 , and the like, the same reference numerals are denoted to the members performing the same functions as the members constituting the loader unit gripping foody  70 A, and the description thereof is omitted. 
     In the first example, the open transpiration device  40  corresponds to a first treatment device, the open transpiration unit gripping body  70 C corresponds to an upper part gripping body, and the open transpiration unit roller conveyor  43  corresponds to a first conveyance body. In addition, the open transpiration unit gripping body  70 C and the open transpiration unit roller conveyor  43  correspond to the upstream side conveyance body. 
     The temperature control press device  50  is configured in the same manner as the hot press device  20 . Therefore, in the temperature control press device  50  shown in  FIGS. 2, 3, 42 , and the like, the same reference numerals are denoted to the members performing the same functions as those of the hot press device  20 , the description thereof is omitted, and differences from the hot press device  20  will be described. It should be noted that in  FIG. 42  and the like, some members constituting the temperature control press device  50  are omitted. 
     Due to the difference in the basic structure that the hot press device  20  is configured to pressurize and heat the veneer shear W 1 , whereas the temperature control press device  50  is configured to pressurize and temperature-control the veneer sheet W 1 , the hot plate  24  (first contact plate) of the hot press device  20  is configured to supply and discharge a heating medium such as high temperature steam or hot oil in order to contact-heat and dry the veneer sheet W 1  and to maintain the temperature of the heating medium according to the type of the veneer sheet W 1 . In contrast, both are different in that the temperature control plate  54  (second contact plate) of the temperature control press device  50  is configured to control the veneer shoot W 1  dried due to providing and discharging of a temperature control medium such as wafer, hot water, and hot oil, energization, or the like to a desired finished temperature (for example, a veneer sheet temperature is 25° C. to 35° C.). 
     The temperature control press device  50  includes a temperature control press unit roller conveyor  31  having a conveyance surface F 2  at the same height as the open transpiration unit roller conveyor  43 . Below the temperature control press unit roller conveyor  31 , e temperature control press unit gripping body  70 D is provided. The temperature control press unit gripping body  70 D is configured in the same manner as the hot press unit gripping body  70 B. Therefore, in the temperature control press unit gripping body  70 D shown in  FIGS. 2, 3, 42 , and the like, the same reference numerals are denoted to the members performing the same functions as those of the members constituting the hot press unit gripping body  70 B, and the description thereof is omitted. 
     In the first example, the temperature control press device  50  corresponds to a second treatment device, the temperature control press unit gripping body  70 D corresponds to a lower part gripping body, and the temperature control press unit roller conveyor  31  corresponds to a second conveyance body. In addition, the temperature control press unit gripping body  70 D and the temperature control press unit roller conveyor  31  correspond to a downstream side conveyance body. Furthermore, the traveling body  71 , the linkage bracket  71   b , and the like of the temperature control press unit gripping body  70   b  correspond to a linkage mechanism, and the roller  31   c  of the temperature control press unit roller conveyor  31  corresponds to an auxiliary conveyance body. 
     In addition, in the first example, the loader unit gripping body  70 A, the loader unit conveyor  15 , the hot press unit gripping body  70 B, and the hot press unit roller conveyor  31  correspond to preceding conveyance devices, and the open transpiration unit gripping body  70 C, the open transpiration unit roller conveyor  43 , the temperature control press unit gripping body  70 D, and the temperature control press unit roller conveyor  31  correspond to subsequent conveying devices. 
     In addition, the unloader device  60  is configured in the same manner as the loader device  10  except that the unloader device  60  includes an unloader shelf  64  instead of the leader shelf  14 . Therefore, in the unloader device  60  shown in  FIGS. 2, 3, 48 , and the like, the same reference numerals are denoted to the members performing the same functions as those of the members constituting the loader device  10 , and the description thereof is omitted. It should be noted that in  FIG. 48  end the like, some members constituting the unloader device  60  are omitted. The unloader device  60  corresponds to a third treatment device. 
     Next, the conveyance paths R 1  to R 4  of the first example will be described. As shown in  FIGS. 2 and 3 , the conveyance paths R 1  to R 4  are arranged in a straight line in a plan view. The conveyance path R 1  is a path positioned over the loader device  10  and the hot press device  20 , the path for carrying out a plurality of veneer sheets W 1  set in a standing state by the loader device  10  while holding them in parallel along the conveying direction and for carrying the plurality of veneer sheets W 1  into the press position of the hot press device  20  (predetermined position between the hot plates  24 ) with the plurality of veneer sheets W 1  being in the standing state. The conveyance steps of the veneer sheet W 1  in the conveyance path R 1  are performed by the drive control of the loader unit gripping body  70 A, the loader unit conveyor  15 , the hot press unit gripping body  70 B, and the hot press unit roller conveyor  31 . The conveyance path R 1  corresponds to a first conveyance path. 
     The conveyance path R 2  is a path positioned over the hot press nee ice  20  and the open transpiration device  40 , the path for carrying out a plurality of veneer sheets W 1  released from pressure due to the hot plate  24  from the press position of the hot press device  20  in a standing state and for carrying the plurality of veneer sheets W 1  in a standing state into the open transpiration position (predetermined position between the open shelves  42 ) of the open transpiration device  40  while holding the plurality of veneer sheets W 1  in parallel along the conveying direction. The conveyance steps of the veneer sheet W 1  in the conveyance path R 2  are performed by the drive control of the hot press unit gripping body  70 B, the hot press unit roller conveyor  31 , the open transpiration unit gripping body  70 C, and the open transpiration unit roller conveyor  43 . The conveyance path R 2  corresponds to a second conveyance path. 
     The conveyance path R 3  is a path positioned over the open transpiration, device  40  and the temperature control press device  50 , the path for carrying out a plurality of veneer sheets W 1  from which water vapor is evaporated from the open transpiration position of the open transpiration device  40  in a standing state and for carrying the plurality of veneer sheets W 1  in a standing state into the press position (predetermined position between the temperature control plates  54 ) of the temperature control press device  50  while holding the plurality of veneer sheets W 1  in parallel along the conveying direction. The conveyance steps of the veneer sheet W 1  in the conveyance path R 3  are performed by the drive control of the open transpiration unit gripping body  70 C, the open transpiration unit roller conveyor  43 , the temperature control press unit gripping body  70 D, and the temperature control press unit roller conveyor  31 . The conveyance path R 3  corresponds to a third conveyance path. 
     The conveyance path R 4  is a path positioned over the temperature control press device  50  and the unloader device  60 , the bath for carrying out a plurality of veneer sheets W 1  released from pressure due to the temperature control plate  54  from the press position of the temperature control press device  50  in a standing state and for carrying the plurality of veneer sheets W 1  in a standing state into the unloader position (predetermined position between the unloader shelves  64 ) of the unloader device  50  while holding the plurality of veneer sheets W 1  in parallel along the conveying direction. The conveyance steps of the veneer sheet W 1  in the conveyance path R 4  are performed by the drive control of the temperature control press unit gripping body  70 D, the temperature control press unit roller conveyor  31 , the unloader unit gripping body  70 E, and the unloader unit roller conveyor  15 . The conveyance path R 4  corresponds to a fourth conveyance path. 
     Next, with reference to  FIG. 14 , the electrical configuration of the conveyance control of this example will be described. The control board  100  for functioning as a control unit of the horizontal multistage press apparatus  1  mainly includes a CPU  101  being an arithmetic device, a ROM  102  being a read only memory device, a RAM  103  being a readable/writable main memory and used as a work area, and an input/output interface (I/O)  104 . These devices ate connected to each other by a bus  105  so as to be capable of mutual transmission and reception. The ROM  102  stores in advance a control program  102   a  for executing conveyance treatment, a setting table  102   b  fox initially setting the size of a surface to be pressurized of the veneer sheet W 1 , and the like. 
     To the input/output interface  104 , a setting switch  201  and a plurality of photoelectric sensors  202   a  to  202   h  are connected so as to function as input means. In addition, the gripping piece cylinders  77  and  78  via the electromagnetic switching valves  211 A to  211 E, the gripping member elevating cylinder  74  via the electromagnetic switching valves  212 A to  212 E, the traveling body motor  72  via the drive circuits  215 A to  215 E, and the conveyor motor  204  via the drive circuits  216 A to  216 E are connected to the input/output interface  104  for each device  10 ,  20 ,  40 ,  50 , and  60  so as to function as output means. 
     In addition, the conveyor elevating cylinder  16  via the electromagnetic switching valves  213 A and  213 E, and the chain conveyor motor  203  via the drive circuits  217 A and  217 E are connected to the input/output interface  104  for each device  10  and  60  so as to function as output means. Furthermore, the press cylinder  27  is connected to the input/output interface  104  via the electromagnetic switching valves  214 B and  214 D for each of the devices  20  and  50  so as to function as an output means. 
     It should be noted that the electromagnetic switching valves  211 A to  211 E are normally switched to the grip releasing position. Therefore, each of the gripping piece cylinders  77  and  78  is normally in the contracted state, and the gripping pieces  81  and  82  of the gripping member  73  are in the expanded state (grip releasing state). When each of the electromagnetic switching valves  211 A to  211 E is switched to the gripping position, the corresponding gripping place cylinders  77  and  78  are in an elongated state, and the gripping pieces  81  and  82  of the gripping member  73  are in a shrunk state (gripping state). 
     The setting switch  201  is an electrostatic type touch switch displayed on, for example, a push button or a touch panel, and is used when information on the veneer sheet W 1  such as the number of sheets to be treated of the veneer sheet W 1  and the size of the surface to be pressurized, the temperature setting of the temperature control plate  54 , and the like are input into the control board  100 . For setting the temperature of the temperature control plate  54 , in the method of supplying and discharging the temperature control medium such as water, hot water, hot oil, and the like into the temperature control plate  54 , according to the outside air temperature during temperature control, water is adopted in the summer season, and hot water, hot oil, and the life are adopted in the winter season, and when the energization type temperature control plate  54  is used, a desired temperature is input. That is, when the veneer sheet W 1  is accommodated in a standing state between the open shelves  42  and water vapor is evaporated from both surfaces thereof, in the winter, there are cases where the veneer sheet temperature (for example, the veneer sheet temperature is 25° C. to 10° C.) is lower than the desired finished temperature (for example, the veneer sheet temperature is 25° C. to 35° C.), and in this case, on the contrary, in the method of supplying and discharging the temperature control medium to raise the temperature of the veneer sheet W 1 , hot water, hot oil, and the like will be adopted. 
     The photoelectric sensor  202   a  detects that the loader unit gripping body  70 A reaches the operation position (grip releasing position) in the loader device  10  (that a part of the veneer sheet W 1  is carried into between the hot plates  24 ). The photoelectric sensor  202   b  detects that the open transpiration unit gripping body  70 C reaches the operation position (grip releasing position) in the open transpiration device  40  (that a part of the veneer sheet W 1  is carried into between the temperature control plates  54 ). The photoelectric sensor  202   c  detects that the unloader unit gripping body  70 E reaches the operation position (grip releasing position) in the unloader device  60  (that the veneer sheet W 1  is carried into the unloader shelf  64 ). 
     The photoelectric sensor  202   d  detects that the veneer sheet W 1  is held in the loader shelf  14 . The photoelectric sensor  202   e  detects that the veneer sheet W 1  is held in the hot press device  20 . The photoelectric sensor  202   f  detects that the veneer sheet W 1  is held in the open shelf  42 . The photoelectric sensor  202   g  detects that the veneer sheet W 1  is held in the temperature control press device  50 . The photoelectric sensor  202   h  detects that the veneer sheet W 1  is held in the unloader shelf  64 . A plurality of photoelectric sensors  202   a  to  202   h  are prepared for each position where a corresponding one of the sensors is provided, and an optimum one is selected according to the size of the veneer sheet W 1 . It should be noted that not limited to a transmission non-contact type detector such as a photoelectric sensor, for example, a contact type or reflective type non-contact type detector may be used. 
     Next, a procedure for drying the veneer sheet W 1  using the horizontal multistage press apparatus  1  having the above-described configuration will be described with reference to the 3D image explanatory diagram schematically representing a main part of the horizontal multistage press apparatus  1  as shown in  FIGS. 23 to 54 . In this case, the control board  100  executes the program indicating the veneer sheet drying treatment as the main routine shown in the flowchart in  FIG. 15 . It should be noted that the flowchart in  FIG. 15  corresponds to one of the respective control programs  102   a  stored in the ROM  102  of the control board  100 . 
     In the veneer sheet drying treatment program in  FIG. 15 , the loader step S 2 , the hot press step S 4 , the open transpiration step S 6 , the temperature control press step S 8 , and the unloader step S 10  respectively correspond to the flow of treatment in the loader device  10 , the hot press device  20 , the open transpiration device  40 , the temperature control press device  50 , and the unloader device  60 . Meanwhile, the first conveyance step S 3 , the second conveyance step S 5 , the third conveyance step S 7 , and the fourth conveyance step S 9  respectively correspond to the flow of treatment in the conveyance paths R 1  to R 4 . 
     Then, in the initial setting S 1 , the loader step S 2 , and the unloader step S 10 , an initial setting program in  FIG. 16 , a loader treatment program in  FIG. 17 , and an unloader treatment program in  FIG. 22  as subroutines are respectively executed. In addition, in the first conveyance step S 3 , the second conveyance step S 5 , the third conveyance step S 7 , and the fourth conveyance step S 9 , the first conveyance treatment program in  FIG. 18 , the second conveyance treatment program in  FIG. 19 , the third conveyance treatment program in  FIG. 20 , and the fourth conveyance treatment program in  FIG. 21  as subroutines are respectively executed. In this case, each subroutine is designed to be independently executed. 
     In the initial setting S 1  in  FIG. 15 , the control board  100  executes the initial setting treatment program shown in the flowchart in  FIG. 16 . Specifically, the control board  100  inputs veneer sheer information on the number of treatment sheets of the veneer sheet W 1  from the setting switch  201  and the size of the surface to be pressurized. Based on the input contents, the setting table  102   b  of the ROM  102  is referred and the photoelectric sensors  202   a  to  202   h  in the optimum position are selected according to the size of the veneer sheet W 1 . In addition, the movement between the original position and the operation position of each traveling body  71  in the loader unit gripping body  70 A, the hot press unit gripping body  70 B, the open transpiration unit gripping body  70 C, the temperature control press unit gripping body  70 D, and the unloader unit gripping body  70 E is set as, for example, the forward/reverse drive amount of the traveling body motor  72  (S 11 ). 
     In the loader step S 2  in  FIG. 15 , the control board  100  executes the leader treatment program shown in the flowchart in  FIG. 17 . In S 21 , it is determined whether or not a predetermined number of veneer sheets W 1  (sheet material to be treated) are held in the loader shelf  14 . If S 21  is executed first, since no veneer sheet W 1  is held in the loader shelf  14  (see  FIG. 23 ), “NO” is determined in S 21 , and in S 22 , it is determined whether or not the loader unit gripping body  70 A and the loader unit conveyor  15  are in the original positions. This is because when the chain conveyor  13  is driven in a state in which the loader unit gripping body  70 A and the loader unit conveyor  15  are in the operation positions (ascent position), the veneer sheet W 1  interferes with the loader unit conveyor  15 . 
     If the loader unit gripping body  70 A and the loader unit conveyor  15  are in the operation positions (“NO” in S 21 ), after the loader unit gripping body  70 A and the loader unit conveyor  15  are returned to their original positions (S 24 ), the chain conveyor  13  is driven by only a predetermined rotation amount (S 23 ), and the veneer sheets W 1  are sent one by one into the loader shelf  14 . Thereafter, the treatment in S 21 , S 22  (determined as “YES”), and S 23  is repeatedly executed in this order, and on the condition that a predetermined number of veneer sheets W 1  are held in the loader shelf  14  (“YES” in S 21 ), the loader treatment is ended. The loader step S 2  corresponds to a first treatment step. 
     The control. board  100  executes the first conveyance treatment program shown in the flowchart in  FIG. 18  in the first conveyance step S 3  In  FIG. 15 . If a predetermined number of veneer sheets W 1  (sheet material to be treated) are held in the loader shelf  14  (“yes” in S 31 ), no veneer sheet W 1  is detected in the hot press device  20  by the photoelectric sensor  202   e  (“NO” in S 32 ), and the loader unit gripping body  70 A is in its original position (gripping position) (see  FIG. 24 , “YES” in S 33 ), the control board  100  switches the electromagnetic switching valve  212 A to the descent position, and lowers the gripping member  73  along with the elongation operation of the gripping member elevating cylinder  74 . 
     Thus, as shown in  FIG. 25 , the gripping pieces  81  and  82  of the gripping member  73  enter the gap between the plurality of veneer sheets W 1  held in the loader shelf  14  in a standing state (gripping position). After the gripping member  73  is lowered, the electromagnetic switching valve  211 A is switched to the gripping position, and along with the elongation operation of the gripping piece cylinders  77  and  78 , the gripping pieces  81  and  82  are made to grip both side surfaces in the upper part of each of the plurality of veneer sheets W 1  (see S 35  and  FIG. 26 ). It should be noted that if the loader unit gripping body  70 A is not in the original position (“NO” in S 33 ), the traveling body motor  72  is driven in the reverse direction to return the loader unit gripping body  70 A to the original position (S 34 ). 
     Next, as shown in  FIG. 27 , the electromagnetic switching valve  213 A is switched to the ascent position, and along with the elongation operation of the conveyor elevating cylinder  16 , the loader unit conveyor  15  is made to rise to the operation position. At this time, the drive of the gripping member elevating cylinder  74  is synchronized with the drive of the conveyor elevating cylinder  16 , and simultaneously with the ascent of the loader unit conveyor  15 , the gripping member  73  is raised (S 36 ). In this state, while both side surfaces in the upper part of each of the plurality of veneer sheets W 1  are suspended by the gripping pieces  81  and  82 , the lower end of each of the veneer sheets W 1  is lifted by the belt conveyor  150  (roller  15   a ) of the leader unit conveyor  15 . 
     As described above, in the first example, using a simple control method of synchronous drive between the conveyor elevating cylinder  16  and the gripping member elevating cylinder  74  causes the conveyance surface F 1  of the loader unit conveyer  15  to coincide with the conveyance surface F 2  of the hot press unit roller conveyor  31 . Thus, the chain conveyor  13  for causing the veneer sheet W 1  to stand up and the loader unit conveyor  15  for carrying the veneer sheet W 1  into the hot press device  20  from the loader device  10  are made compatible. 
     Next, as shown in  FIG. 28 , the traveling body motor  72  of the loader unit gripping body  70 A is driven to rotate forward and the traveling body  71  is made to move forward to the operation position (grip releasing position). At this time, the drive of the loader unit conveyor motor  204  is synchronized with the drive of the traveling body motor  72 , and the belt conveyor  150  (the roller  15   a ) is rotated for a predetermined time in accordance with the moving speed of the traveling body  71  (S 37 ). Thus, the plurality of veneer sheets W 1  enter between the hot plates  24  of the hot press device  20  along the respective approach paths. 
     At this time, as shown in  FIG. 29 , for example, the hot press unit gripping body  70 B is in a standby state with the position where the upper and of the gripping member  73  is opposed to the lower end of the left end portion (starting and portion) of the veneer sheet W 1  as its original position. The roller  31   c  supports and guides the lower end of the veneer sheet W 1  entering between the hot plates  24  together with the rollers  31   a  and  31   b.    
     After execution of the treatment in S 37 , on the condition that the loader unit gripping body  70 A reaching the operation position (grip releasing position) is detected by the photoelectric sensor  202   a,  the electromagnetic switching valve  212 B is switched to the ascent position, and along with the elongation operation of the gripping member elevating cylinder  74  of the hot press unit gripping body  70 B, the gripping member  73  is made to ascend. The gripping pieces  81  and  82  of the gripping member  73  in the expanded state enter the gap between the plurality of veneer sheets W 1  held in the standing state between the hot plates  24 . After the gripping member  73  is raised, the electromagnetic switching valve  211 B is switched to the gripping position, and along with the elongation operation of the gripping piece cylinders  77  and  78 , the gripping pieces  81  and  82  are made to grip both side surfaces in the lower part of each of the plurality of veneer sheets W 1  (see S 38  and  FIG. 30 ). 
     Next, the electromagnetic switching valve  211 A is switched to the grip releasing position, and the gripping pieces  81  and  82  of the loader unit gripping body  70 A are brought into the grip releasing state. That is, switching the electromagnetic switching valve  211 B to the gripping position and switching the electromagnetic switching valve  211 A to the grip releasing position shift the gripping position of the veneer sheet W 1  from the upper part to the lower part to support the veneer sheet W 1 . Thereafter, as shown in  FIG. 31 , the traveling body motor  72  of the hot press unit gripping body  70 B is driven to rotate forward and the traveling body  71  is made to move forward to the operation position (S 39 ). This operation position is sat to a position where the roller  31   c  comes into contact with the roller  31   a  or a position near the roller  31   a.    
     It should be noted that when the photoelectric sensor  202   d  detect, that no veneer sheet W 1  remains in the loader shell  14 , the control board  100  reversely drives the traveling body motor  72  of the loader unit gripping body  70 A at the timing, tor example, when the loader device  10  receives a new veneer sheet W 1  from the feed mechanism and returns the loader unit gripping body  70 A to the original position. At this time, the electromagnetic switching valve  213 A is switched to the descent position, and along with the contraction operation of the conveyor elevating cylinder  16 , the loader unit conveyor  15  is made to descend. Thereafter, the loader treatment in  FIG. 17  is executed in the loader device  10  in the same manner as described above. 
     If the traveling body  71  reaches the operation position once, and the veneer sheet W 1  reaches the press position (predetermined pressurizing position) of the hot press device  20 , the process proceeds to S 41  according to the determination of “YES” in S 40 , and if the traveling body  71  reaches the operation position only once, and the veneer sheet W 1  does not reach the press position (predetermined pressurizing position) of the hot press device  20  (“NO” in S 40 ), feed control by the traveling body  71  is performed according to the length of the veneer sheet W 1  so that the veneer sheet W 1  is fed to its press position. For example, the electromagnetic switching valve  211 B is switched to the grip releasing position, the gripping pieces  81  and  82  of the hot press unit gripping body  70 B are brought into the grip releasing state, the traveling body  71  is made to return by the necessary amount according to the length of the veneer sheet W 1 , and then, as shown in  FIG. 32 , the electromagnetic switching valve  211 B is switched to the gripping position, and the gripping pieces  81  and  82  of the hot press unit gripping body  70 B are caused to grip the lower part of the veneer sheet W 1  again. In this state, as shown in  FIG. 33 , the traveling body motor  72  is driven to rotate forward and the traveling body  71  is again made to move forward to the operation position (S 39 ). Thus, the veneer sheet W 1  is fed to the press position of the hot press device  20 . 
     If the veneer sheet W 1  is fed to the press position of the hot press device  20  (“YES” in S 40 ), the electromagnetic switching valve  211 B is switched to the grip releasing position, and the gripping pieces  81  and  82  of the hot press unit gripping body  70 B are brought into the grip releasing state, and then, the electromagnetic switching valve  212 B is switched to the descent position, and along with the contraction operation of the gripping render elevating cylinder  74 , the gripping member  73  is made to descend. In this state, the traveling body motor  72  of the hot press unit gripping body  70 B is driven to rotate reversely and the traveling body  71  is made to return to its original position (see S 41  and  FIGS. 35 and 36 ). After execution of the treatment in S 41 , the first conveyance treatment is ended. In the first example, the treatment from S 35  to S 37  in  FIG. 18  corresponds to the upstream side carry-out step, and the treatment in S 38  and S 39  corresponds to the downstream side carry-in step. 
     Returning to  FIG. 15 , in the hot press step in S 4 , the control board  100  switches the electromagnetic switching valve  214 B to the closing position, and closes the plurality of hot plates  24  simultaneously along with the elongation operation of the press cylinder  27  of the hot press device  20 . Pressurizing and heating are performed for a predetermined time according to the type of the veneer sheet W 1 , and then the electromagnetic switching valve  214 B is switched to the open position, and along with the contraction operation of the press cylinder  27  of the hot press device  20 , the plurality of hot plates  24  are simultaneously opened. The hot press step in S 4  corresponds to a second treatment step. 
     The control. board  100  executes the second conveyance treatment program shown in the flowchart in  FIG. 19  in the second conveyance step in  5 S in  FIG. 10 . In S 51 , the photoelectric sensor  202   f  determines whether or not the veneer sheet W 1  (sheet material to be treated) is held in the open shelf  42 . When S 51  is executed first, since the veneer sheet W 1  is not held in the open shelf  42  (see  FIG. 36 ), “NO” is determined in S 51 , on the condition that the hot press step is ended (“YES” in S 52 ), the electromagnetic switching valve  212 B is switched to the ascent position, and along with the elongation operation of the gripping member elevating cylinder  74 , the gripping member  73  of the hot press unit gripping body  70 B in the original position is made to ascend. Thus, as shown in  FIG. 37 , the gripping pieces  81  and  32  of the gripping member  73  enter the gap between the plurality of veneer sheets W 1  held in the hot plates  24  in a standing state. After the ascent of the gripping member  73 , the eiectromagnetic switching valve  211 B is switched to the gripping position, and the gripping pieces  81  and  82  or the hot press emit gripping body  70 B are caused to grip the lower part of the veneer sheet W 1  (S 53 ). 
     In this state, as shown in  FIG. 38 , the traveling body motor  72  of the hot press unit gripping body  70 B is driven to rotate forward and the traveling body  71  is made to move forward to the operation position (S 54 ). At this time, the drive of the hot press unit conveyor motor  204  is synchronized with the drive of the traveling body motor  72 , and the rollers  31   a  and  31   b  are rotated for a predetermined time in accordance with the moving speed of the traveling body  71  (S 54 ). Since the open transpiration unit gripping body  70 C is normally on standby in the original position, and moreover, the gripping pieces  81  and  82  of the gripping member  73  are in the expanded state, the plurality of veneer sheets W 1  enter between the open shelves  42  of the open transpiration device  40  along each approach path while the upper part of the plurality of veneer sheets W 1  passes through the gripping pieces  81  and  82 . 
     When the photoelectric sensor  202   e  detects that the hot press unit gripping body  70 B reaches the operation position, the electromagnetic switching valve  211 C is switched to the gripping position, and along with the elongation operation of the gripping piece cylinders  77  and  78  of the open transpiration unit gripping body  70 C, the gripping pieces  81  and  82  are made to grip both side surfaces in the upper part of each of the plurality of veneer sheets W 1 . At the same time, the electromagnetic switching valve  211 B is switched to the grip releasing position, and the gripping pieces  81  and  82  of the hot press unit gripping body  70 B are brought into the grip releasing state (S 55 ). That is, switching the electromagnetic snitching valve  211 C to the gripping position and switching the electromagnetic switching valve  211 B to the grip releasing position shift the gripping position of the veneer sheet W 1  from the lower part to the upper part to support the veneer sheet W 1 . 
     Thereafter, as shown in  FIG. 39 , the traveling body motor  72  of the open transpiration unit gripping foody  70 C is driven to rotate forward and the traveling body  71  is caused to move forward to the operation position (S 56 ). At this time, the drive of the open transpiration unit conveyor motor  204  is synchronized with the drive of the traveling body motor  72 , and the roller  43   a  is rotated for a predetermined time in accordance with the moving speed of the traveling body  71 . Thus, each of the plurality of veneer sheets W 1  is held in the open transpiration position (atmospheric release position) at predetermined intervals in the open shelf  42 , which allows water vapor to evaporate from both surfaces in the standing state into the atmosphere. 
     When the photoelectric sensor  202   b  detects that the open transpiration unit gripping body  70 C reaches the operation position, the electromagnetic switching valve  211 C is switched to the grip releasing position, and along with the contraction operation of the gripping piece cylinders  77  and  78 , the gripping pieces  81  and  82  are brought into the grip releasing state, and then the traveling body motor  72  of the open transpiration unit gripping body  70 C is reversely driven, and the traveling body  71  is made to return to its original position (see S 57  and  FIG. 40 ). After the execution of the treatment in S 57 , the second conveyance treatment is ended. 
     Returning to  FIG. 15 , in the open transpiration step in S 6 , the control beard  100  holds each veneer sheet W 1  in a standing state in the open shelf  42  for a predetermined time, for example, until the pressing and heating time in the hot press device  20  of the next veneer sheet W 1  elapses. The moisture contained in each veneer sheet W 1  is evaporated into the atmosphere while steaming from both surfaces of each veneer sheet W 1 . The open transpiration step in S 6  corresponds to a first treatment step. 
     The control beard  100  executes the third conveyance treatment program shown in the flowchart in  FIG. 20  in the third conveyance step S 7  in  FIG. 15 . In S 61 , the photoelectric sensor  202   g  determines whether or not the veneer sheet W 1  (sheet material to be treated) is held in the temperature control press device  50 . When S 61  is executed first, since the veneer sheet W 1  is not held in the temperature control press device  50  (see  FIG. 40 ), “NO” is determined in S 61 , and on the condition that the open transpiration step is ended in S 62  (“YES” in S 62 ), the treatment in S 63  is executed. 
     In S 63 , the electromagnetic switching valve  211 C is switched to the gripping position, and along with the elongation operation of the gripping piece cylinders  77  and  78 , the gripping pieces  81  and  82  of the open transpiration unit gripping body  70 C in the original position are made to grip both side surfaces in the upper part of each of the plurality of veneer sheets W 1 . In this stats, as shoes in  FIG. 41 , the traveling body motor  72  of the open transpiration unit gripping body  70 C is driven to rotate forward and the traveling body  71  is caused to move forward to the operation position. At this time, the drive of the open transpiration unit conveyor motor  204  is synchronized with the drive of the traveling body motor  72 , and the roller  43   a  is rotated for a predetermined time in accordance with the moving speed of the traveling body  71  (S 63 ). Thus, the plurality of veneer sheets W 1  enter between the temperature control plates  54  of the temperature control press device  50  along the respective approach paths. 
     At this time, as shown in  FIG. 42 , for example, the temperature control press unit gripping body  70 D is in a standby state with the position where the upper end of the gripping portion  73  is opposed to the lower end of the left end portion (starting and portion) of the veneer sheet W 1  as its original position. The roller  31   c  of the temperature control press unit roller conveyor  31  supports and guides the lower end of the veneer sheet W 1  entering between the temperature control plates  54  together with the: rollers  31   a  and  31   b.    
     After execution of the treatment in S 63 , on the condition that the open transpiration unit gripping body  70 C reaching the operation position (grip releasing position) is detected by the photoelectric sensor  202   b , the electromagnetic switching valve  212 D is switched to the ascent position, and along with the elongation operation of the gripping member elevating cylinder  74  of the temperature control press unit gripping body  70 D, the gripping member  73  is made to ascend. The gripping pieces  81  and  82  of the gripping member  73  in the expanded state enter the gap between the plurality of veneer sheets W 1  held in the standing state between the temperature control plates  54 . After the gripping member  73  is raised, the electromagnetic switching valve  211 D is switched to the gripping position, and along with the elongation operation of the gripping piece cylinders  77  and  78 , the gripping pieces  81  and  82  are made to grip both side surfaces in the lower part of each of the plurality of veneer sheets W 1  (see S 64  and  FIG. 43 ). 
     Next, the electromagnetic switching valve  211 C is switched to the grip releasing position, and the gripping pieces  81  and  82  of the open transpiration unit gripping body  70 C are brought into the grip releasing state. That is, switching the electromagnetic switching valve  211 D to the gripping position and switching the electromagnetic switching valve  211 C to the grip releasing position change the gripping position of the veneer sheet W 1  from the upper part to the loner part to support the veneer sheet W 1 . Thereafter, as shown in  FIG. 44 , the traveling body motor  72  of the temperature control press unit gripping body  70 D is driven to rotate forward and the traveling body  71  is caused to move forward to the operation position (S 65 ). 
     This operation position is set to a position where the roller  31   c  comes into contact with the roller  31   a  or a position near the roller  31   a.  It should be noted that when the photoelectric sensor  202   f  detects that no veneer sheet W 1  is left in the open shelf  42 , the control board  100  executes the second conveyance treatment in  FIG. 19  in the open transpiration device  40  in the same manner as described above. 
     If the traveling body  71  reaches the operation position once, and the veneer sheet W 1  reaches the press position (predetermined pressurizing position) of the temperature control press device  50 , the process proceeds to S 67  according to the determination of “YES” in S 66 , and if the traveling body  71  reaches the operation position only once, and the veneer sheet W 1  does not reach the press position (predetermined pressurizing position) of the temperature control press device  50  (“NO” in S 66 ), feed control by the traveling body  71  is performed according to the length of the veneer sheet W 1  so that the veneer sheet W 1  is fed to its press position. For example, the electromagnetic switching valve  211 D is switched to the grip releasing position, the gripping pieces  81  and  82  of the temperature control press unit gripping body  70 D axe brought into the grip releasing state, the traveling body  71  is made to return by the necessary amount according to the length of the veneer sheet W 1 , and then, as shown in  FIG. 45 , the electromagnetic switching valve  211 D is switched, and the gripping pieces  81  and  82  of the temperature control press unit gripping body  70 D are caused to grip the lower part of the veneer sheet W 1  again. In this state, as shown in  FIG. 46 , the traveling body motor  72  is driven to rotate forward and the traveling body  71  is again made to move forward to the operation position (S 65 ). Thus, the veneer sheet W 1  is fed to the press position of the temperature control press device  50 . 
     If the veneer sheet W 1  is fed to the press position of the temperature control press device  50  (“YES” in S 66 ), the electromagnetic switching valve  211 D is switched to the grip releasing position, and the gripping pieces  81  and  81  of the temperature control press unit gripping body  70 D are brought into the grip releasing state, and then, the electromagnetic switching waive  212 D is switched to the descent position, and along with the contraction operation of the gripping member elevating cylinder  74  or the temperature control press unit gripping body  70 D, the gripping member  73  is made to descend. In this state, the traveling body motor  72  of the temperature control press unit gripping body  70 D is driven to rotate reversely and the traveling body  71  is made to return to its original position (see S 67  and  FIG. 47 ). After the execution of the treatment in S 67 , the third conveyance treatment is ended. In the first example, the treatment in S 63  in  FIG. 20  corresponds to the upstream side carry-out step, and the treatment in S 64  and S 65  corresponds to the downstream side carry-in step. 
     Returning to  FIG. 15 , in the temperature control press step in S 8 , the control board  100  switches the electromagnetic switching valve  214 D to the closing position, and closes the plurality of temperature control plates  54  simultaneously along with the elongation operation of the press cylinder  27  of the temperature control press device  50 . The temperature control plate  54  is set to a temperature according to the outside air temperature or the like by the supply and discharge of the temperature control medium such as water, hot water, and hot oil, or by energization or the like, and is pressurized and temperature-controlled for a predetermined time according to the type of the veneer sheet W 1 , and then the electromagnetic switching valve  214 D is switched to the open position, and along with the contraction operation of the press cylinder  27  of the temperature control press device  50 , the plurality of temperature control plates  54  are made to simultaneously open. The temperature control press step in S 8  corresponds to a second treatment step. 
     The control board  100  executes the fourth conveyance treatment program shown in the flowchart in  FIG. 21  in the fourth conveyance step in S 9  in  FIG. 15 . If the photoelectric sensor  202   h  does not detect the veneer sheet W 1  (sheet material to be treated) in the unloader shelf  64  (“NO” in S 71 ), and if the temperature control step is ended (“YES” in S 72 ), and the unloader unit roller conveyor  15  is in the operation position, a conveyance surface F 3  horizontally continuous with the conveyance surface F 2  of the temperature control press unit roller conveyor  31  is formed (see  FIG. 48 ), and on the condition that the unloader unit gripping body  70 E returns to the original position (gripping position) (“YES” in S 74 ), the control board  100  switches the electromagnetic switching valve  212 E to the descent position, and along with the elongation operation of the gripping member elevating cylinder  74 , makes the gripping member  73  to descend (see S 76  and  FIG. 49 ). 
     Thereafter, the feed control by the traveling body  71  of the temperature control press unit gripping body  70 D is performed according to the length of the veneer sheet W 1  so that the veneer sheet W 1  is carried into the unloader shelf  64  with one forward movement operation by the unloader unit gripping body  70 E. For example, from the state shown in  FIG. 50 , the electromagnetic switching valve  211 D is switched to the grip releasing position, the gripping pieces  81  and  82  of the temperature control press unit gripping body  70 D are brought into the grip releasing state, the traveling body  71  is made to return by the necessary amount according to the length of the veneer sheet W 1 , and then, as shown in  FIG. 51 , the electromagnetic switching valve  211 D is switched, and the gripping places  81  and  82  of the temperature control press unit gripping body  70 D are caused to grip the lower part of the veneer sheet W 1  again. Thus, the veneer sheet W 1  is fed by a predetermined amount to the unloader shelf  64  side, the upper part of the left end portion (starting end portion) of the veneer sheet W 1  is guided into between the expanded gripping pieces  81  and  82 , and the lower end of the left end portion (starting end portion) of the veneer sheet W 1  is supported and guided on the unloader unit roller conveyor  15  (see S 76  and  FIG. 52 ). The treatment in S 76  corresponds to a back side carry-out step. 
     After the treatment in S 76 , the electromagnetic switching valve  211 E is switched to the gripping position, and along with the elongation operation of the gripping piece cylinders  77  and  78 , the gripping pieces  81  and  82  are made to grip both side surfaces in the upper part of each of the plurality of veneer sheets W 1 . At the same time, the electromagnetic switching valve  211 D is switched to the grip releasing position, and the gripping pieces  81  and  82  of the temperature control press unit gripping body  70 D are brought into the grip releasing state (S 77 ). That is, switching the electromagnetic switching valve  211 E to the gripping position and switching the electromagnetic switching valve  211 D to the grip releasing position shift the gripping position of the veneer sheet W 1  from the lower pert to the upper part 
     to support the veneer sheet W 1 . 
     Next, the traveling body motor  72  of the unloader unit gripping body  70 E is driven to rotate forward and the traveling body  71  is made to move forward to the operation position (grip releasing position). At this time, the drive of the unloader unit conveyor motor  204  is synchronized with the drive of the traveling body motor  72 , one the roller  15   a  is rotated for a predetermined time in accordance with the moving speed of the traveling body  71  (S 78 ). Thus, the plurality of veneer sheets W 1  enter the standing position in the unloader shelf  64  along the respective approach paths. The treatment In S 77  and S 78  corresponds to a back side carry-in step. 
     After the execution of the treatment in S 78 , on the condition that the photoelectric sensor  202   c  detects the unloader unit gripping body  70 E reaching the operation position (grip releasing position), the electromagnetic switching valve  211 E is switched to the grip releasing position, arid the gripping pieces  81  and  82  of the unloader unit gripping body  70 E are brought into the grip releasing state. Next, the electromagnetic switching valve  212 E is switched to the ascent position, the gripping member  73  of the unloader unit gripping body  70 E is made to ascend, and then, the unloader unit gripping body  70 E is made to return to the original position (gripping position). Thereafter, the electromagnetic switching valve  213 E is switched to the descent position, and along with the contraction operation of the conveyor elevating cylinder  16 , the unloader unit roller conveyor  15  is made to descend to the original position (S 79 ). Thus, along with the descent of the unloader unit roller conveyor  15 , the plurality of veneer sheets W 1  descend while the respective lower ends are supported by the roller  15   a  of the unloader unit roller conveyor  15  (see  FIG. 7B ). Since the veneer sheet W 1  having undergone the open transpiration step and the temperature control press step is hardened by moisture escape, as shown in  FIG. 7B , the lower end is not rounded when supported by the roller  15   a . After the execution of the treatment in S 79 , the fourth conveyance treatment is ended. 
     In the unloader step in S 10  in  FIG. 15 , the control beard  100  executes the unloader treatment program shown in the flowchart in  FIG. 22 . In S 81 , it is determined whether or not the unloader unit roller conveyor  15  is in the original position. If the unloader unit roller conveyor  15  is in the original position (“YES” in S 81 ), and the gripping member  73  of the unloader unit gripping body  70 E ascends (“YES” in S 82 ), the chain conveyor  13  is driven by a predetermined rotation amount (S 84 ), and the veneer sheet W 1  is pulled out one by one from the unloader shelf  64  (see  FIG. 54 ). If the gripping member  73  of the unloader unit gripping body  70 E does not ascend (“NO” in S 82 ), the electromagnetic snitching valve  212 E is switched to the ascent position, the gripping member  73  of the unloader unit gripping body  70 E is made to ascend (S 83 ), and then the chain conveyor  13  is driven by a predetermined rotation amount. The pulled out veneer sheet W 1  is taken out to the outside of the unloader device  60  by a carry-out mechanism (not shown). If the treatment in S 84  and S 85  (determined as “YES”) are repeatedly executed in this order, and the veneer sheet W 1  disappears in the unloader shelf  64  (“NO” in S 85 ), the electromagnetic switching valve  213 E is switched to the ascent position, and along with the elongation operation of the conveyor elevating cylinder  16 , the unloader unit roller conveyor  15  is made to ascend to the operation position (S 86 ). Thereafter, the unloader treatment is ended. The unloader step corresponds to a third treatment step. 
     As is apparent from the above description, in the horizontal multistage press apparatus  1  and the multistage conveyance method using the same in the first example, the eager part of the veneer sheet W 1  (sheet material to be treated) in a standing state is gripped to be conveyed to the middle (first half), that is, conveyed to the operation position of each of the loader unit gripping body  70 A and the open transpiration unit gripping body  70 C, and then the gripping position is shifted to the lower part and the conveyance in the second half, that is, the conveyance to the operation position of each of the hot press unit gripping body  70 B and the temperature control press unit gripping body  70 D is performed. Thus, a. large space and a large-scale lifting mechanism above the hot plate  24  or the temperature control plate  54  are unnecessary for conveying the veneer sheet W 1 , and the driving force for carrying in the veneer sheet W 1  can be reduced. 
     In addition, in the first example, in the conveyance path R 1 , the gripping position is shifted from the loader unit gripping body  70 A for gripping the upper part of the veneer sheet W 1  to convey the veneer sheet W 1  to the hot press unit gripping body  70 B for gripping the lower part of the veneer sheet W 1  to convey the veneer sheet W 1 , and in the conveyance oath R 3 , the gripping positron is shifted from the open transpiration unit gripping body  70 C for gripping the upper part of the veneer sheet W 1  to convey the veneer sheet W 1  to the temperature control press unit gripping body  700  for gripping the lower part of the veneer sheet W 1  to convey the veneer sheet W 1 . 
     Meanwhile, in the conveyance path R 2 , the gripping position is shifted from the hot press unit gripping body  70 B for gripping the lower part of the veneer sheet W 1  to convey the veneer sheet W 1  to the open transpiration unit gripping body  70 C for gripping the upper part of the veneer sheet W 1  to convey the veneer sheet W 1 , and in the conveyance path R 4 , the gripping position is shifted from the temperature control press unit gripping body  70 D for gripping the lower part of the veneer sheet W 1  to convey the veneer sheet W 1  to the unloader unit gripping body  70 E for gripping the upper part Of the veneer sheet W 1  to convey the veneer sheet W 1 . 
     Thus, since in the hot press device  20  and the temperature control press device  50 , any of the devices effectively utilize the spaces below the insides of the respective devices, and are respectively provided with the hot press unit gripping body  70 B and the temperature control press unit gripping body  70 D, it is possible to satisfactorily avoid interference with existing facilities such as fluid pipes for heating or temperature control provided in the upper space. 
     Here, when the horizontal multistage press apparatus  1  is designed to have specifications to be applicable to various sires of veneer sheets W 1 , in the hot press device  20  and the temperature control press device  50 , it can be considered that the region of the non-pressurized part where pressurization by the hot plate  24  and the temperature control plate  54  is impossible can be set smaller in the method of gripping the lower part of the veneer sheet W 1  to convey the veneer sheet W 1  than in the method of gripping the upper part of the veneer sheet W 1  to convey the veneer sheet W 1 . 
     That is, even if the veneer sheet W 1  is small, in order for the upper part to be gripped by the gripping pieces  81  and  82 , it is necessary to set the original position of the gripping body to be provided in the upper part lower to some extent. This means that the region of the non-pressurized part protruding from the hot plate  24  and the temperature control plate  54  in the upper part or the veneer sheet W 1  becomes larger. This non-pressurized part is a region with high moisture content and eventually becomes a part to be removed. In addition, in particular, in the hot press device  20 , since adhesive substances such as resin transpiring during the opening of the hot plate  24  after completion of the hot press step are likely to adhere to the device, providing a gripping body in the upper part of the veneer sheet W 1  may invite malfunction of the traveling body  71 . 
     In contrast, in the first example, any of the hot press unit gripping body  70 B corresponding to the hot press device  20  in the conveyance paths R 1  and R 2  and the temperature control press unit gripping body  70 D corresponding to the temperature control press device  50  in the conveyance paths R 3  and R 4  are configured to grip the lower part of the veneer sheet W 1  to convey the veneer sheet W 1 . Thus, the region of the non-pressurized part can be set small, and eventually the removal part of the veneer sheet W 1  can be reduced. In addition, malfunction of the traveling body  71  can he favorably prevented. 
     It should be noted that in the first example, the case where the invention is applied to a horizontal multistage press apparatus  1  of the type in which the loader device  10 , the hot press device  20 , the open transpiration, device  40 , the temperature control press device  50 , and the unloader device  60  are arranged in this order from the upstream side in the conveying direction is described, but the invention is not limited to this, and for example, it is possible to omit the temperature control press step. That is, the case is where in an environment where the material and thickness of the veneer sheet W 1 , the weather conditions during drying, the use of the veneer sheet W 1 , and the like, and furthermore, the outside air temperature are substantially constant, or in an environment where the temperature in the factory is substantially constantly controlled, only executing the open transpiration step obtains the same effect as the effect obtained when the temperature control step is performed on the veneer sheet W 1 . Alternatively, for example, as shown in  FIG. 55 , the invention can also be applied to a horizontal multistage press apparatus  1 B of the type in which the open transpiration device  40  and the temperature control press device  50  are omitted, and the loader device  10 , the hot press device  20 , arid the unloader device  60  are arranged in this order from the upstream side in the conveying direction. That is, the invention only has to include at least one set of carry-out and carry-in steps including an upstream side carry-out step of carrying out the sheet material to be treated from the first device with the upper part of the sheet material to be treated gripped and suspended, and a downstream side carry-in step of carrying the sheet material to be treated into the second device with the gripping position of the sheet material to be treated shifted from the upper part to the lower part and supported, and the invention is not limited to the mode having two sets of carry-out and carry-in steps as in the first example. In any of the horizontal multistage press apparatus  1  and  1 B, it is decided whether to use the upper part gripping body or the lower part gripping body to conform to the structural characteristics of each device  10 ,  20 , and the like, and smooth conveyance of the veneer sheet W 1  in the standing state is secured. 
     In addition, in the loader unit conveyor  15 , the hot press unit roller conveyor  31 , the temperature control press unit roller conveyor  31 , and the unloader unit roller conveyor  15 , a non-drive idling roller may be adopted in place of some or all of the drive rollers. According to this, the driving force during conveying the veneer sheet W 1  can be further reduced. 
     In addition, the invention is not limited to the above-described example and modifications thereof, and can be implemented in various modified forms without departing from the spirit of the invention. 
     REFERENCE SIGNS LIST 
       1 ,  1 B horizontal multistage press apparatus (multistage conveyance apparatus, multistage press apparatus) 
       10  loader device (first treatment device) 
       15  loader unit conveyor (first conveyance body, preceding conveyance device) 
       20  hot press device (second treatment device) 
       31  hot press unit roller conveyor (downstream side conveyance body, second conveyance body, preceding conveyance device) 
       31  temperature control press unit roller conveyor (downstream side conveyance body, second conveyance body, subsequent conveyance device) 
       24  hot plate (first contact plate) 
       40  open transpiration device (first treatment device) 
       43  open transpiration unit roller conveyer (first conveyance body, subsequent conveyance device) 
       50  temperature control press device (second treatment device) 
       54  temperature control plate (second contact plate) 
       60  unloader device 
       70 A loader unit gripping body (upstream side conveyance body, upper part gripping body, preceding conveyance device) 
       70 B hot press unit gripping body (downstream side conveyance body, lower part gripping body, preceding conveyance device) 
       70 C open transpiration unit gripping body (upstream side conveyance body, upper part gripping body, subsequent conveyance device) 
       70 D temperature control press unit gripping body (downstream, side conveyance body, lower part gripping body, subsequent conveyance device) 
       100  control board (control unit) 
     W 1  veneer sheet (sheet material to be treated) 
     R 1  to R 4  conveyance path (first to fourth conveyance paths) 
     F 1  to F 3  conveyance surface