Abstract:
A chip conveyor (K) which receives chips delivered from a machine tool (MC) in a receiving area (R 1 ) transfers chips to a delivery position a specified distance apart from the receiving area, and is provided with an endless carrier ( 18 ) rotatably in a specified direction to deliver chips at the delivery position, characterized in that a passage ranging from the receiving area to the delivery position is used as a go route (R 2 ) for the carrier, a passage ranging from the delivery position back to the receiving position is used as a return route (R 3 ) for the carrier, and a separating device ( 25 ) which separates chips from the carrier by allowing liquid to act on the chips adhering to the carrier which passes the delivery position so that their adhesiveness is reduced or eliminated is installed in the return route, whereby the residual chips can be removed efficiently from the carrier so as to increase the durability of the carrier and a drive mechanism.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a chip conveyor, which conveys cutting chips produced in the operation of a machine tool, such as a lathe or the like, from a receiving position to a discharge position, and a chip-separating/recovery apparatus used with the chip conveyor. 
     As a conventional chip conveyor, the chip conveyor disclosed in Japanese Unexamined Utility Model Publication No. Sho 59-55645 has been proposed. This chip conveyor includes a circulating conveying member and a bucket removably located at the discharge position of the chips. Chips containing cutting oil are conveyed by the conveying member to the discharge position, and just after the chips reach the discharge position, they are received by the bucket. A number of small holes for filtering the cutting oil are provided in the bottom portion of the bucket. 
     Further, air is sprayed from the outlet of nozzle on the lower surface of the conveying member so that chips that have adhered to the lower surface of the conveying member fall into the bucket. The cutting oil adhered to the chips is recovered through an oil recovery pipe from the number of small holes of the bucket. 
     However, in the above-mentioned chip conveyor, since the air sprayed through the nozzle has insufficient peel force, the chips adhered to the lower surface of the conveying member by oil cannot be reliably separated or recovered. Although the chips can be separated from the conveying member by increasing the air pressure through the nozzle, not only is a special structure for preventing the flying of chips is needed, but also a supply source for a high-pressure fluid is needed. 
     On the other hand, the present applicant proposed a chip conveyor disclosed in Japanese Unexamined Patent Publication No. Sho 63-123656. In this chip conveyor, an endless type mesh belt is provided inside a horizontal frame and an inclined frame. The horizontal frame is arranged in a chip-receiving region, and chips from a machine tool are introduced onto the horizontal frame. Then, the conveyor belt is circulated within and along the horizontal frame and the inclined frame and the chips introduced onto the horizontal frame are conveyed to the upper end of the inclined frame, and the chips are discharged from the chip conveyor. 
     Further, a spraying member is arranged between the upper and lower traveling portions of the mesh belt in the horizontal frame. By spraying coolant toward the lower traveling portion of the mesh belt, the lower traveling portion of the mesh belt is cleaned. A recovery tank for recovering the coolant adhered to the belt and fine chips is arranged on the inclined frame. 
     However, in this chip conveyor also, the chips cannot be reliably removed by only spraying the coolant on the mesh belt. Further, not only is a special structure for preventing the flying of coolant and chips needed, but also a supply source for a high-pressure fluid is needed. 
     Even when the conveying member of the belt and the like passes through the chip-discharge position, if a piece of a chip is adhered to the conveying member, the chip can enter between sliding parts forming the conveying member to wear the parts. Further, the chip can enter between sliding parts of a mechanism that drives the conveying member, which will decrease the life of the driving mechanism. Moreover, when the remaining chips fall and accumulate in the receiving position, the accumulated chips must be manually removed, which is troublesome. 
     Further, Japanese Unexamined Utility Model Publication No. Sho 61-191849 describes a cutting-water separation apparatus used for a machine tool. This separation apparatus includes a tank for receiving chips from the machine tool, a chip conveyor for discharging the chips from the tank, a supporting plate, which receives cutting water dropping from the vicinity of a head pulley of the chip conveyor, and a pipe for recovering the cutting water dropped on the supporting plate. 
     When the endless conveying member of the chip conveyor is moved along a forward route from the tank to the head pulley, it conveys chips from the tank to the head pulley and drops the chips from the head pulley. Further, when the endless conveying member is moved along a return route from the head pulley to the tank, cutting water, which drops from the head pulley, is returned back to the tank through the supporting plate, the pipe, and the hose. 
     However, in this separation apparatus, it is hardly possible to recover chips that adhere to the conveying member. The supporting plate and pipe are used for recovery of only a small amount of cutting water, and the cutting water dropped on the supporting plate is collected into the pipe along the inclination of the supporting plate. The cutting water is not used for the separation of remaining chips adhered to the conveying member. 
     All of the chips put on the chip conveyor from the tank in the receiving position are not dropped into a recovery box from the chip conveyor in the discharge position, and some of the chips adhere to the conveyor by liquid crosslinking adhesion and are returned to the receiving position. The returned chips accumulate in the tank in the receiving position. In a case of aluminum machining, the rate of returned chips is more than 50%, which is a large amount, and the tank is immediately filled with the chips. In this case, after the operation of the machine tool is stopped and the cutting water is drained from the machine tool, the chips must be removed from the tank, which is troublesome. 
     In addition, since the chips accumulated in the tank are discharged, it is possible to use a screw conveyor. However, since the tank is usually provided on the ground, it is necessary to form an underground pit by an excavating operation to install the screw conveyor, which greatly increases the operating cost. 
     To prevent the provision of an underground pit, the tank may be located at a position higher than the ground. However, in this case, the machine tool itself, other than the tank, must also be located at a position higher than the ground, which also increases costs greatly. Further, the working position of workpieces becomes higher than necessary and the operation becomes inconvenient. 
     This invention has been made to solve the abovementioned problems. The object of the present invention is to provide a chip conveyor that can separate and recover chips remaining on a conveying member in the forward route so that the durability of the conveying member and the driving mechanism is improved, which improves the degree of freedom in locating the remaining chip separation apparatus to simplify the provision of the separation apparatus. 
     Further, in addition to the above object, another object of the present invention is to provide a chip separation/recovery apparatus the construction of which is simplified so that attachment and detachment operations with respect to a discharge portion of the chip conveyor is simplified. 
     BRIEF SUMMARY OF THE INVENTION 
     To attain the above-mentioned object, in a preferred embodiment of the present invention, a chip conveyor is provided, in which chips discharged from a machine tool are received in a receiving region, the chips are conveyed to a discharge position spaced by a predetermined distance from the receiving region, and an endless conveying member is located for discharging the chips at the discharge position such that the conveying member can be circulated in a predetermined direction. In this chip conveyor a path from the receiving region to the discharge position is defined as a forward route of the conveying member. A path from the discharge position where returned to the receiving region is defined as a return route of the conveying member. A separation apparatus for separating chips from the conveying member is provided in the return route, and the separation apparatus causes a liquid to act on chips adhered to the conveying member after passing through the discharge position to reduce or remove the adhesion. 
     In another embodiment of the present invention, a chip separation/recovery apparatus used in the chip conveyor is provided. The apparatus includes a liquid storage tank containing a liquid, through which a conveying member passes on the return route of the conveying member, and a mechanism, which is provided in the liquid storage tank and which causes the conveying member to detour. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a cross-sectional view showing a chip separation/discharge apparatus in which this invention is embodied; 
     FIG. 2 is a cross-sectional view taken along the line  2 — 2  of FIG. 1; 
     FIG. 3 is a cross-sectional view taken along the line  3 — 3  of FIG. 2; 
     FIG. 4 is a cross-sectional view showing an entire chip conveyor; 
     FIG. 5 is a schematic front view showing another embodiment; 
     FIG. 6 is a schematic front view showing another embodiment; 
     FIG. 7 is a main portion cross-sectional view showing another embodiment; 
     FIG. 8 is a main portion cross-sectional view showing another embodiment; 
     FIG. 9 is a main portion cross-sectional view showing another embodiment; 
     FIG. 10 is a main portion cross-sectional view showing another embodiment; 
     FIG. 11 is a main portion front view showing another embodiment; 
     FIG. 12 is a main portion front cross-sectional view showing another embodiment; 
     FIG. 13 is a perspective view of a discharge tube used in the embodiment of FIG. 12; 
     FIG. 14 is a perspective view showing a modified example of the discharge tube; 
     FIG. 15 is a perspective view showing a modified example of the discharge tube; 
     FIG. 16 is a main portion cross-sectional view showing another embodiment; 
     FIG. 17 is a schematic front view showing another embodiment; 
     FIG. 18 is a main portion cross-sectional view showing another embodiment; 
     FIG. 19 is a cross-sectional view taken along the line  19 — 19  of FIG. 18; 
     FIG. 20 is a perspective view of a nozzle showing another embodiment; and 
     FIG. 21 is a schematic front view showing another embodiment. 
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     One embodiment, in which the present invention is embodied in a chip conveyor used in a machine tool, will now be described with reference to FIGS. 1 to  4 . 
     FIG. 4 shows an entire chip conveyor K. A machine tool MC is located on a side of the chip conveyor. When a cutting operation of an article is carried out by the machine tool, chips are produced. The chip conveyor K is mounted on a floor surface so that the chips can be recovered from the machine tool and conveyed to another position. 
     At a chip receiving position, a recovery tank  11  within which a water-soluble or oily coolant liquid C is stored. The lower horizontal portion of a conveyor body  12  is provided in the recovery tank  11 . A trough  13  of the conveyor body  12  includes a recovery portion  14 , which extends horizontally in the recovery tank  11 , a raised portion  15 , which extends obliquely upward from the recovery portion  14 , and a discharge portion  16 , which extends substantially horizontally from the upper end of the raised portion  15  to a discharge position. 
     Sprocket wheels  17   a  and  17   b  are rotatably supported in the recovery portion  14  and the discharge portion  16  of the trough  13 , respectively, and an endless type conveying member  18  is looped between the sprocket wheels  17   a  and  17   b . A plurality of conveying scrapers  19  are provided on the outer surface of the conveying member  18  and spaced apart by predetermined distances. 
     As shown in FIG. 4, a motor  39  is fixed to the upper surface of the discharge portion  16 , and on the output shaft  39   a  of the motor  39 , a drive sprocket wheel  45   a  is provided. On a supporting shaft  24 , which supports the sprocket wheel  17   b , a driven sprocket wheel  45   a  is provided. A chain  45   c  is looped over the drive sprocket wheel  45   a  and the driven sprocket wheel  45   b . The conveying member  18  is driven by the motor  39  and the conveying member  18  counterclockwise along the recovery portion  14 , the raised portion  15  and the discharge portion  16 , as shown by an arrow in FIG.  4 . 
     Above the conveying member  18 , a separation apparatus  20  is provided on the recovery portion  14  of the trough  13 . A lower opening  21   a  of the casing  21  forming the separation apparatus  20  communicates with an upper opening  14   a  of the recovery portion  14 . An introduction inlet  21   b  of the casing  21  is formed in the side wall on an upstream side of the casing  21 , and into the introduction inlet  21   b  is inserted the downstream end of a trough  22  extending from the machine tool into the casing  21 . A coolant liquid C containing the chips  23  discharged from the machine tool flows into the casing  21  through the trough  22 . The chips  23  include heavy chips  23   a , which fell into the lower portion from the liquid level W of the coolant in the casing  21 , and light chips, which floats on the liquid level W of the coolant. The floating chips  23   b  are recovered by the conveying member  18  at a position a where the conveying member  18  in the raised portion  15  crosses the coolant liquid level W. Further, the fallen chips  23   a  are recovered by the conveying member  18  at a position β where the conveying member  18  faces the trough  22 . 
     A separation/recovery apparatus attached to the lower side of the discharge portion  16  will now be described. 
     In this embodiment, as shown in FIG. 4, the chips  23  are discharged into the recovery tank  11  located relative to the machine tool MC from the machine tool through the trough  22 . The receiving region of the chips  23  extends horizontally along the machine tool MC and is set to a given length. A part of the conveying member  18  is arranged on the receiving passage in this receiving region R 1 . Further, the forward route R 2  of the conveying member  18  includes a region from a point E 1 , which is located at an end of the receiving passage where the discharge of chips is started from the recovery tank  11 , to a point E 2 , where the conveying member  18  is turned back by the sprocket wheel  17   b . Further, a region where the conveying member  18  is turned back from the turning point E 2  to the starting point E 3  of the receiving passage is defined as a return route R 3 . The forward route R 2  and the return route R 3  are substantially parallel. 
     The discharge portion  16  includes a pair of side walls  26 ,  26 , which support a supporting shaft  24  of the sprocket wheel  17   b , and the respective ends and the lower sides of the both side walls  26 ,  26  are opened. Some of the chips conveyed by the conveying member  18  fall down from the conveying member  18  as it turns at the opening of the end portion as shown by an arrow in FIG. 1, and are recovered by the recovery box B 1  shown in FIG.  4 . 
     To the lower end portions of the side walls  26 ,  26  is attached the separation/recovery apparatus  25 , which separates and recovers chips  23  that adhere to the conveying member  18  and have not fallen. The separation/recovery apparatus  25  includes a liquid storage tank  28 . To the outsides of the side walls  26 ,  26  are fixed flange metal fittings  27 ,  27  by welding or the like. To the liquid storage tank  28  are welded flange metal fittings  29 ,  29 . In addition, the liquid storage tank  28  is fixed to the side walls  26 ,  26  by fastening the flange metal fittings  27 ,  27  and the flange metal fittings  29 ,  29  with a bolt  30  and a nut  31 . 
     The liquid storage tank  28  has a laterally elongated triangular tubular shape, and the top surface of the liquid storage tank  28  is opened toward the lower surface of the discharge portion  16 . The lower portion of the liquid storage tank  28  is focused to a triangular (tapered) shape in cross section and the lower end thereof is arcuate in cross section. 
     To the liquid storage tank  28  is rotatably supported a support shaft  33  through bearings  34 ,  34 , and to this support shaft  33  are attached a pair of sprocket wheels  35 ,  30   35  for routing the conveying member into the liquid storage tank  28 . On the inside surface of the side walls  26 ,  26  are provided guide flanges  36 ,  37  for guiding the circulation of the side edges of the conveying member  18 . It is noted that in this embodiment a detouring mechanism of the conveying member  18  is formed by the support shaft  33 , bearings  34 ,  34 , and sprocket wheels  35 ,  35 . 
     The coolant liquid C is stored in the internal space  38  of the liquid storage tank  28 . Chips  23  adhered to the conveying member  18  are separated by immersing the conveying member in the coolant liquid C while detouring the conveying member  18  therein. Separated chips  23  fall to the bottom portion of the liquid storage tank  28 . As a device for discharging the fallen chips, a screw conveyor  40  is attached to an arcuate portion on the lower end of the liquid storage tank  28 . 
     The conveyor  40  will be described. A discharge trough  28   a  is formed on the lower portion of the liquid storage tank  28  parallel to the support shaft  33 . A rotating shaft  42  is supported on one side wall  28   b  of the liquid storage tank  28  relative to this trough  28   a , and an impeller wheel  44  is fixed to the outer periphery of a mounting shaft tube  43 , which is fitted to the rotating shaft  42  by welding. A pin  45  connects the rotating shaft  42  and the mounting shaft tube  43 . To the outer end of the support shaft  33  is mounted a drive sprocket wheel  46  and to the outer end of the rotating shaft  42  is fitted and fixed a driven sprocket wheel  47 . A chain is looped over the sprocket wheels  46 ,  47 . 
     An outer periphery of the end portion of the impeller wheel  44  for the screw conveyor  40  is restricted in terms of the position by an inner peripheral surface of a discharge tube  50  having a cylindrical cross section. 
     On the outside wall of the liquid storage tank  28  is an auxiliary liquid storage tank  49  for housing the sprocket wheels  46 ,  47 , the chain  48  and the like. On the opposite side of the auxiliary liquid storage tank  49 , the discharge tube  50  is attached to extend obliquely upward to an outer side wall of the liquid storage tank  28 , and the discharge tube  50  is connected to the discharge trough  28   a . The level of an opening of the end of this discharge tube  50  is higher than the liquid level of the coolant liquid C in the liquid storage tank  28 . 
     As shown in FIG. 2, the internal space  38  of the liquid storage tank  28  communicates with the internal space  51  of the auxiliary liquid storage tank  49  through an opening  28   c  formed in the side wall  28   b . A cleaner  54  is provided in the recovery tank  11 . The coolant liquid in the recovery tank  11  is cleaned by the cleaner  54 , and supplied from a pump  52 , which is a liquid replenishing device, and a pipe  53  to the internal space  51  of the auxiliary liquid storage tank  49 . 
     As shown in FIG. 1, a discharge trough  56  that extends substantially horizontally bridges between a chute  55  forming the raised portion  15  and the liquid storage tank  28  for discharging the coolant liquid C in the liquid storage tank  28 . When the coolant liquid C is returned to the recovery tank  11 , the discharge trough  56  is used as a precipitating/recovery apparatus, which removes fine chips  23  contained in the coolant liquid on the bottom of the discharge trough  56  and also recovers them. 
     The discharge trough  56  is provided with an end-plate  56   a , which prevents the fine chips  23  from moving toward the chute  55 . A dish-shaped concave portion  56   b  is provided on the bottom portion of the discharge trough  56 , as shown by a chain line in FIG. 1, whereby the amount of fallen chips  23  can be increased. 
     As shown in FIG. 1, a guide  57  is arranged between the liquid storage tank  28  and the sprocket wheel  17   b , and the side edges of the guide  57  are fixed to the side walls  26 ,  26  by welding or the like. The distal edge of the guide  57  is shifted from the sprocket wheel  17   b  toward the liquid storage tank  28  to be located under the conveying member  18 . Thus, the guide  57  leads chips  23  and coolant liquid C that have passed through the sprocket wheel  17   b  and fallen through the conveying member  18  into the liquid storage tank  28 . 
     Although the position of the distal edge of the guide  57  may be as shown by a solid line in FIG. 1, the distal edge may be located in the vicinity of a vertical line passing through the turning point E 1  of the conveying member  18 , as shown by a chain line. In this case, a larger amount of coolant liquid C can be led to the liquid storage tank  28  along the guide  57 , and the amount of coolant liquid that falls into the recovery box B 1  is decreased. 
     Next, the operations of the chip conveyor constructed as mentioned above will be described. 
     As shown in FIG. 4, when the coolant liquid C containing chips  23  flows into the casing  21  through the trough  22  from the machine tool, heavy chips  23   a  fall in the vicinity of the receiving position β and are recovered between the respective scrapers  19 . On the other hand, light chips  23   b  float on the coolant liquid at the liquid level W. When the conveying member  18  is raised from the liquid level W, the light chips  23   b  are collected by the scraper  19 . Then, the heavy chips  23   a  and light chips  23   b  are conveyed by the conveying member  18  and they are moved upward in the raised portion  15  to reach the opening of the discharge portion  16 . When the conveying member  18  passes through the sprocket wheel  17   b  and returns, comparatively heavy chips  23   a  fall down from the conveying member  18  and are recovered by the recovery box B 1 . 
     Further, even when the conveying member  18  passes around the sprocket wheel  17   b , some of the heavy chips  23   a  and light chips  23   b  are moved into the liquid storage tank  28  of the separation/recovery apparatus  25  while adhering to the conveying member  18  and are immersed in the coolant liquid C. Here, the chips  23  are separated by the coolant liquid C and fall to the discharge trough  28   a.    
     On the other hand, as shown in FIG. 2, since the support shaft  33  is rotated by the circulation of the conveying member  18 , the impeller wheel  44  of the screw conveyor  40  is rotated through the drive sprocket wheel  46 , the chain  48 , the driven sprocket wheel and the rotating shaft  42 . The impeller wheel  44  transports the chips  23  within the discharge trough  28   a  toward the discharge tube  50 . The chips  23  that have fallen from the discharge tube  50  are recovered in the recovery box B 2  shown in FIG.  4 . 
     The chip separation/recovery apparatus  25  constructed as described above has the following effects. 
     (1) In the above-mentioned embodiment, in the return route R 3  of the conveying member  18 , the liquid storage tank  28  is attached to the lower portion of the discharge portion  16 , a liquid such as the coolant liquid C or the like is stored in the liquid storage tank  28 , and the conveying member  18  is configured to be advanced into the liquid. Thus, the liquid in the liquid storage tank  28  acts on chips adhered to the conveying member  18  so that the adhesion is decreased or removed, and the chips  23  are efficiently separated from the surface of the conveying member  18  in the liquid storage tank  28 . 
     Further, since the liquid storage tank  28  and screw conveyor  40  are provided in the return route R 3  of the conveying member  18 , as compared with a case where they are provided under the recovery tank  11 , an excavated underground pit is not required. Therefore, the degree of freedom in locating the separation/recovery apparatus is improved and the installation thereof can be easily carried out. 
     Here, the principle of separating chips  23  from the surface of the conveying member  18 , will be explained. It is assumed that the chips  23  are aluminum particles, and the aluminum particles are adhered to the surface of the conveying member  18  through an oil component contained in the coolant liquid. In this state, liquid crosslinking adhesion by oil and van der Waals force act between the conveying member  18  and the aluminum particles, so that the aluminum particles are adhered to the conveying member  18  by both forces. The liquid crosslinking adhesion is significantly larger than the van der Waals force with respect to the entire particle diameters. Thus, when the entire aluminum particles are exposed to the coolant liquid, the liquid crosslinking adhesion is eliminated and the particles can be in a state where they are adhered to, the conveying member by only the Van der Waals force. The van der Waals force is likely to be influenced by the surrounding environment, and the magnitude of the var der Waals force is further significantly reduced when the surrounding environment is air rather than liquid. As described above, the aluminum particles are efficiently separated from the conveying member  18  by exposing the aluminum particles to the coolant liquid., 
     (2) In the embodiment, as the discharge device for discharging chips  23  fallen on the lower portion of the liquid storage tank  28 , the screw conveyor  40  was provided. Therefore, the chips  23  can be automatically discharged. 
     (3) In the embodiment, the circulating movement of the conveying member  18  is used as the driving force of the screw conveyor  40 . Thus, it is not necessary to additionally provide an exclusive driving source, and the structure can be simplified. 
     (4) In the embodiment, the discharge trough  56  was provided between the liquid storage tank  28  and chute  55 . Thus, in a process where the coolant liquid is discharged from the liquid storage tank  28  to the chute  55  through the discharge trough  56 , fine chips  23  contained in the coolant liquid fall on the bottom surface of the discharge trough  56  by setting the flow rate of the liquid at about 0.1 to 1 m/min. As a result, the recovery of fine chips  23  can be carried out, and at the same time no clogging of the cleaner  54 , which separates the coolant liquid in the recovery tank  11 , occurs, and the maintenance can be easily conducted. It is noted that the slower the flow rate of the coolant liquid is, the more reliably the falling of fine chips is carried out. 
     (5) In the embodiment, the distal end portion of the discharge portion  16  is opened and the chips  23  are caused to fall naturally. The chips  23  that do not fall are separated by the chip separation/recovery apparatus  25 . Accordingly, the supply of the coolant liquid C supplied to the liquid storage tank  28  can be set to the minimum necessity. 
     (6) In the embodiment, the auxiliary liquid storage tank  49  is attached to the side portion of the liquid storage tank  28 , and the auxiliary liquid storage tank  49  communicates with the liquid storage tank  28 . Therefore, the storage volume of the coolant liquid C is increased. Further, the sprocket wheels  46 ,  47  and the bearings  34 ,  41  are located in the auxiliary liquid storage tank  49 . Thus, it is not necessary to exclusively provide a seal structure in the bearings  34 ,  41 , and the structure can be simplified. 
     (7) In the embodiment, the coolant liquid C is supplied to the auxiliary liquid storage tank  49 , and clean coolant liquid is supplied into the auxiliary liquid storage tank  49 . Thus, the durability of the present apparatus is improved since chips do not enter the driving mechanism of the screw conveyor  40 . 
     (8) In the embodiment, the level of the end opening of the discharge tube  50  is higher than the level of the coolant liquid C in the liquid storage tank  28 . Thus, the amount of coolant liquid adhered to chips  23  discharged from the discharge tube  50  is reduced. 
     (9) In the embodiment, the chip separation/recovery apparatus  25  includes the liquid storage tank  28  containing liquid in which the conveying member  18  is immersed and passes through in the return route, and the sprocket wheels  35 ,  35  provided in the liquid storage tank  28  are used as a detour mechanism which detours the conveying  30  member  18  to reverse movement. In addition, the chip separation/recovery apparatus  25  is removably located under the discharge portion  16 . Therefore, the configuration of the chip separation/recovery apparatus  25  is simplified and the attachment and detachment operations are easily carried out. 
     The embodiment can be modified and embodied as follows. In the following embodiments, members having the same functions in the above-mentioned embodiment are denoted with the same reference numerals, and explanations thereof will be omitted. 
     As shown in FIG. 5, the conveying member  18  is substantially horizontal and the recovery tank  11  is located under the receiving region R 1 , so that the separation/recovery apparatus  25  for chips  23  may be attached in the vicinity of the discharge portion and spaced from the receiving region R 1 . In this case, the same effects as in the above-mentioned embodiment are also obtained. 
     The recovery tank  11 , which stores the coolant liquid, is omitted and cutting oil and chips are caused to directly fall on the upper surface of the conveying member  18 , so that the chips may be conveyed to the discharge position. In this case, it is not necessary to provide the chip separation/recovery apparatus  25 , thus the degree of freedom in locating the entire apparatus is increased. 
     As shown in FIG. 6, the discharge portion  16  the distal end portion of the conveying member  18  can be housed in the liquid storage tank  28  of the chip separation/recovery apparatus  25 . In this case, all chips  23  on the conveying member  18  can be recovered in the liquid storage tank  28 , and the structure shown in FIG. 6 can be further simplified as compared with that of the embodiment shown in FIG.  4 . 
     As shown in FIG. 7, a cover  61  is rotatably supported by a shaft  62  in the distal end portion of the discharge portion  16 , and the rotation position of the cover  61  is controllably supported, so that the size of the opening may be controlled by the cover  61 . In this case, when separation and recovery of chips which are difficult to fall down naturally from the conveying member  18  are performed, the cover is closed, and when chips which are easy to fall down naturally are discharged, or maintenance therefor is conducted, the cover  61  can be opened. 
     As shown in FIG. 8, a configuration in which the discharge portion  16  is sealed tightly and the discharge portion  16  is provided with the chip separation/recovery apparatus  25 , may be used. In this case, all chips  23  on the conveying member  18  are recovered in the liquid storage tank  28 , and the structure of the apparatus is further simplified as compared with the embodiment in FIG.  4 . 
     As shown in FIG. 9, the chip separation/recovery apparatus  25  may be attached to the middle of the raised portion  15 . In this case, space under the raised portion  15  can be effectively utilized. 
     As shown in FIG. 10, a supply nozzle  71  for the coolant liquid C is arranged so that liquid C is directed both perpendicular to and in the movement direction of the conveying member  18  in the liquid storage tank  28 , so that a circulating flow is produced in the liquid storage tank  28 , and the coolant liquid C in the liquid storage tank  28  is agitated. Alternatively, the coolant liquid C may be agitated by a screw. In this case, kinetic energy is applied to the coolant liquid C in the liquid storage tank. Thus, a shearing force is imparted to the oil that adheres aluminum particles to the conveying member, and the separation of aluminum particles from the conveying member  18  is reliably performed. 
     As shown in FIG. 11, another sprocket wheel  72 , which is different from the driven sprocket wheel  45   b , is fitted to the outer end portion of the supporting shaft  24 , and the chain  48  may be looped over the sprocket wheel  72  and the sprocket wheel  47 . Alternatively, the drive sprocket wheel  45   a  is changed to double wheels, and the chain may be looped over one of the double wheels and the driven sprocket wheel  47 , as shown by a chain line in FIG.  11 . In any case, the rotation of the screw conveyor  40  is properly conducted in synchronization with the rotation movement of the motor  39 . As a result, the discharge operation of chips is smoothly carried out. 
     Further, since a common motor  39  can be used for the conveying member  18  and the screw conveyor  40 , when an overload acts on the motor  39  through the conveying member  18  and the screw conveyor  40 , safety mechanisms to remove the overload can be unified and the configuration of the control circuit of the motor  39  can also be simplified. 
     The screw conveyor  40  may be driven by an independent, exclusive motor. In this case, the discharge operation of the chips  23  can be properly effected by an actuating signal of the control device according to the amount of discharged chips. 
     In place of the discharge tube  50  shown in FIG. 2, an elbow-shaped discharge tube  50  may be used as shown in FIGS. 12 and 13. The elbow-shaped discharge tube  50  includes a first portion  50   a  extending horizontally and a second portion  50   b  extending obliquely upward from the first portion  50   a . The second portion  50   b  is formed in a bugle shape so that the distal end has a larger passage surface area. A chip guide plate  50   c  is attached to an opening edge of the second portion  50   b  and is arranged above the recovery box B 1 . Thus, in this case, it is not necessary to provide the recovery box for the conveying member  18  and the screw conveyor  40 , respectively, and the chips  23  discharged from the discharge tube  50  and conveying member  18  can be recovered by a single recovery box B 1 , and the recovery box B 2  can be omitted. 
     In place of the discharge tube  50  shown in FIG. 13, an elbow-shaped discharge tube shown in FIG. 14 may be used. This discharge tube has an elbow-shaped portion  50   e , and a distal end opening of the elbow-shaped portion  50   e  is provided with a trough portion  50   d . Alternatively, as shown in FIG. 15, a polygonal, elbow-shaped discharge tube  50  formed by welding a plurality of band plates, may be used. 
     As shown by solid lines in FIG. 16, a spray nozzle  81  (liquid supply device) for the coolant liquid C is provided inside the conveying member  18 , and the coolant liquid C is sprayed onto the back of the conveying member  18  through the spray nozzle  81 , and the coolant liquid C may be then caused to fall into the liquid storage tank  28 . Alternatively, as shown by a chain line in FIG. 16, the spray nozzle  81  may be provided outside the conveying member  18 . 
     Before and after the conveying member  18  enters the liquid storage tank  28  in the return route R 3 , the nozzles  81  spray coolant liquid C on the conveying member  18  and cause the coolant liquid C to flow toward the liquid storage tank  28 . Thus, in place of the spray nozzle  81  a nozzle from which coolant drops may be used. 
     In this case, some of chips  23  adhered to the conveying member  18  before it enters the liquid storage tank  28  are removed, and chips  23  that are not removed in the liquid storage tank  28  are removed from the conveying member outside of the liquid storage tank so that the chips  23  fall into the liquid storage tank  28 . As a result, the recovery efficiency is improved and at the same time the replenishment of coolant liquid C into the liquid storage tank  28  is performed. 
     As shown in FIG. 17, the liquid storage tank  28  may be provided in the vicinity of the recovery tank  11 . In this case, a pipe necessary for conducting the coolant liquid C in the recovery tank  11  can be shortened, and the installation of the apparatus is facilitated. 
     In other embodiments shown in FIGS. 18 and 19, a device that reduces or removes the liquid crosslinking adhesion for adhering chips to the conveying member  18  is different from that of the embodiment of FIG.  1 . That is, the embodiment of FIG. 1 has a system that causes the conveying member  18  to enter the liquid storage tank  28 . However, in this embodiment, the conveying member  18  passes through the upper portion of the liquid storage tank  28  without entering it. A plurality of pipes  91  facing each other are provided on the upper and lower sides of the conveying member  18  above the liquid storage tank  28 . The coolant liquid C flows out of an outlet  91   a  of each pipe  91  toward the conveying member  18 , and the liquid crosslinking adhesion is reduced or removed by the contact with the coolant liquid C. 
     In place of the pipes  91 , a flat hollow body  92  provided with a number of outlets  92   a  shown in FIG. 20, may be used. In the embodiments of FIG.  18  and FIG. 20 the configuration to detour the conveying member  18  in the liquid storage tank  28  is not necessary, and the structure of the apparatus is simplified and the production and assembly operations can be easily performed. 
     As shown in FIG. 21, an inclined trough  93  is provided to form a path that is parallel with the inclined portion of the return route R 3 , so that the conveying member  18  passes through the interior of the inclined trough  93 . Then, the coolant liquid C is pumped by a pump  94  from the recovery tank  11  through the cleaner  54  and is caused to flow in the inclined trough  93  so that the movement speed of the coolant liquid C becomes substantially the same as that of the conveying member  18 . Thus, the chips adhered to the conveying member  18  are separated and recovered in the liquid storage tank  28 . In this case, since the time during which the conveying member  18  is immersed in the coolant liquid C is greater, the separation efficiency of chips is improved. 
     Further, the discharge trough is deep, and a small discharge device, like the above-described screw conveyor  40  and discharge tube  50 , can be provided at the bottom of the discharge trough  56 . This discharge device is driven in cooperation with the circulating movement of conveying member  18 . In this case, fine chips, which fall in the discharge trough  56 , can be automatically discharged. 
     In place of the coolant liquid C, for example water, cleaning fluid or the like can be used. 
     Further, in place of the screw conveyor  40 , a scraping mechanism employing a scraper, a belt conveyor, or a bucket conveyor can be used. 
     The discharge tube  50  may be flexible so that a discharge direction of the chips may be changed. 
     The sprocket wheels  35  and the screw impeller wheels  44  may be alternately provided in the liquid storage tank  28 . 
     Industrial Applicability 
     According to the present invention, liquid acts on chips that remain adhered to the conveying member by the liquid crosslinking adhesion due to an oil component, and the liquid crosslinking adhesion is reduced or removed. Thus, the chips that remain adhered are efficiently removed and the durability of the conveying member and the driving mechanism is improved. Further, the degree of freedom in installing the apparatus for separating the chips that adhere is increased and the installation of the entire apparatus can be easily carried out.