Abstract:
An ejector apparatus wherein, in mounting a lift core to a slide base, and in mounting an ejector core to an ejector plate, it is easy to mount the lift and ejector cores to the slide base and the ejector plate, and simultaneously perform adjustment that allows for thermal expansion of the cores. The ejector apparatus includes a lift core extending through a core constituting a mold and movably installed in a longitudinal direction of the lift core with respect to a surface of the core; an ejector plate arranged between the core and a base plate, and being capable of moving up and down, the base plate being arranged below and spaced from the core; and an adjustment coupling constructed such that a lower end portion of the lift core is supported to expand and contract in a longitudinal direction of the lift core relative to the ejector plate.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an ejector apparatus for moving a lift core which extends through a core constituting a component of a resin molding mold to form an undercut portion in a molded piece and which is installed so as to be capable of moving obliquely with respect to the core surface and in the longitudinal direction.  
         [0003]     2. Description of the Related Art  
         [0004]     An apparatus for moving a lift core which extends obliquely through a core constituting a component of a resin molding mold to form an undercut portion in a molded piece and which is movable in the longitudinal direction, is called an ejector apparatus, an example of which is disclosed, for example, in JP 10-95019 A.  
         [0005]      FIG. 1  schematically shows the construction of the ejector apparatus as disclosed in JP 10-95019 A.  
         [0006]      FIG. 1  shows a conventional ejector apparatus  20 , which was created by the present inventor. In the apparatus shown, a slide base  33  is arranged in a slide path  32  formed in a vertically movable ejector plate  26 , and the slide base  33  is forced to slide as the ejector plate  26  moves up and down, whereby an appropriate axial operating force is imparted to a lift core  28 .  
         [0007]      FIG. 2  shows the overall configuration of a resin molding mold A equipped with this ejector apparatus  20 . The general construction of this mold is as follows: a core  21   b  is arranged under a mold main body  21   a , with the mold main body  21   a  and the core  21   b  defining a resin molding space  22  ( FIG. 1 ).  
         [0008]     Below the core  21   b , there is arranged a base plate  23 , and, between the core  21  and the base plate  23 , there is arranged a spacer  24  on either side, thus defining a chamber  25  between the spacers  24  under the core  21   b . In this chamber  25 , the ejector plate  26  is arranged so as to be vertically movable. Note that  FIG. 1  is a partial sectional view, taken along the line I-I, of the resin molding mold A shown in  FIG. 2 .  
         [0009]     In this resin molding mold A, there is provided a lift core  28  which is passed through an angle setting hole  27  (inclined by an angle K) of the core  21   b  constituting the resin molding mold A to form an undercut portion in a molded piece formed in the above-mentioned resin molding space  22  and which extends obliquely and is longitudinally movable.  
         [0010]     The upper end portion of this lift core  28  functions as a mold portion  28   a  which cooperates with the core  21   b  to form a molded piece, and, by the side of this upper portion, there is formed a protrusion  28   b  for integrally forming an L-shaped flange portion (which also constitutes a part of the undercut portion) in the molded piece.  
         [0011]     This lift core  28  is passed through a guide hole  31   a  formed obliquely in a guide plate  31  which is fitted into a recess  29  formed in the lower surface of the core  21   b  and which is fastened to the core  21   b  by bolts  30 , with the lift core  28  extending downwardly from the core  21   b.    
         [0012]     This guide plate  31 , which allows smooth longitudinal sliding of the lift core  28  due to the guide hole  31   a  formed in the guide plate  31  at a predetermined angle K, functions as a bearing. Since the inclination angle K is determined by the angle setting hole  27  formed in the core  21   b , the guide hole  31   a  may be a loose fit or clearance hole.  
         [0013]     This lift core  28  is caused to slide vertically in the angle setting hole  27  of the core  21   b  by the ejector apparatus  20 . The ejector apparatus  20  used for this purpose includes an ejector plate  26  composed of two plates  26   a  and  26   b  superimposed one upon the other.  
         [0014]     Formed in the lower plate  26   b  of the ejector plate  26  is the slide path  32 , which extends in the direction in which the lower end of the lift core  28  makes relative horizontal movement when it ascends and descends. The slide base  33  is slidably arranged in this slide path  32 , and the lower end portion  28   d  of the lift core  28  is retained by one end portion of the slide base  33  with respect to the sliding direction of the lift core  28 .  
         [0015]     Further, the ejector apparatus  20 , which raises and lowers the lift core, is equipped with an angular guide rod (hereinafter simply referred to as the guide rod)  38  which is adjacent to the lift core  28  and which is parallel thereto. At either end of this guide rod  38 , there is formed a V-shaped cutout  39 . The upper end portion of the guide rod  38  is supported by engaging one cutout  39  thereof with a pin  40  mounted across a through hole  31   b  formed in the guide plate  31 .  
         [0016]     Incidentally,  FIG. 3  is an overall view of the slide base  33  slidably provided in the ejector plate  26 . This slide base  33  includes a base main body  34  having at its ends with respect to the sliding direction thereof forked portions  34   a  and  34   b  that are U-shaped in plan view. In one forked portion  34   a  of this base main body  34 , there is arranged a shaft coupling  35 , and, in the other forked portion  34   b , there is arranged a guide bush  36 .  
         [0017]     The shaft coupling  35  arranged in the forked portion  34   a  is rotatably mounted to opposed wall surfaces by means of pins or the like.  FIG. 4  is an enlarged view of the forked portion  34   a  of the base main body  34  where the shaft coupling  35  is mounted.  
         [0018]     As is apparent from  FIGS. 1 through 4 , formed at the upper end of the shaft coupling  35  is a recess or seat  35   a  for receiving the lower end portion of the lift core  28 . Further, the shaft coupling  35  is equipped with a through-hole  35   b  having a central axis perpendicular to the rotation axis of the shaft coupling  35  and matched with the center line of the recess  35   a  mentioned above.  
         [0019]     The lower end portion of the lift core  28  is fitted into the recess  35   a  at the upper end of the shaft coupling  35  rotatably mounted to one forked portion  34   a  of the base main body  34 , and the end portion of a bolt  37  inserted into the through-hole  35   b  from the lower end of the shaft coupling  35  as shown in  FIG. 1  is threadedly engaged with a tapped hole formed in the lower end surface of the lift core  28 , whereby the lower end portion of the lift core  28  is firmly secured to the coupling  35 .  
         [0020]     The guide bush  36  mounted to the other forked portion  34   b  of the base main body  34  has a passing hole  36   a  extending along an axis perpendicular to the rotation axis of the guide bush  36 , and the above-mentioned guide rod  38  is slidably passed through this passing hole  36   a.    
         [0021]     The guide rod  38 , which is supported at its upper end by the guide plate  31  and which is passed through the passing hole  36   a  of the guide bush  36  of the slide base  33 , extends toward the base plate  23  through a clearance hole  41  formed in the lower plate  26   b , and the cutout  39  at its lower end is engaged with a pin  43  of a holder bush  42  mounted to the base plate  23 , whereby the lower end of the guide rod is supported and secured.  
         [0022]     This holder bush  42  is inserted into an opening  44  formed in the base plate  23  and is secured in position by bolts  45 . As described above, the guide rod  38  is arranged so as to be parallel to the lift core  28 , that is, inclined by the same angle as the lift core  28 . As is apparent from  FIG. 1 , the distance between the core  21   b  and the base plate  23  (that is, the height of the spacers  24 ) is fixed, so that the setting of the angle of the guide rod  38  depends upon the horizontal positional relationship, that is, the distance, between the pin  40  provided in the guide plate  31  and the pin  43  provided in the holder bush  42 .  
         [0023]     In this conventional ejector apparatus  20 , when the ejector plate  26  ascends, the slide base  33  arranged in the slide path  32  formed in the ejector plate  26  also ascends, and a vertical moving force is imparted to the lift core  28 , whose lower end is connected to the slide base  33 .  
         [0024]     In this process, as a result of its ascent, the slide base  33  receives a horizontal component of a moving force biasing it to move along the guide rod  38 , which is mounted at the same inclination angle as the lift core  28 . As a result, a moving force to push up the lift core  28  in the longitudinal and axial directions is imparted to the lift core  28 . Descent of the ejector plate  26  results in an operation contrary to the above, and the lift core  28  is pulled down in the longitudinal direction thereof through the slide base  33 .  
         [0025]     Incidentally, the inclination angle K (See  FIG. 5A ) of the lift core  28  in this ejector apparatus is changeable to an arbitrary angle according to the molded piece  22  to be obtained, and the inclination angle K of this lift core  28  is determined by the user who is going to produce the molded piece  22  by using this ejector apparatus  20  Thus, as for the longitudinal length of the lift core  28 , additional setting is required on the part of the user who has purchased the ejector apparatus  20 .  
         [0026]     In view of this, in the conventional ejector apparatus, when fixing the lower end portion  28   d  of the lift core  28  to the slide base  33 , (1) the lift core  28 , prepared in a relatively large length, is temporarily incorporated, and (2) the amount á by which the protrusion  28   b  of the lift core  28  protrudes on the molded piece side (See  FIG. 5B ) is measured, determining the corrected set value of the rod length of the lift core  28  from this measurement value á. And, the lift core  28  has to be pulled out for additional machining to adjust the rod length thereof before incorporating it again.  
         [0027]     Further, in the operation of assembling the ejector apparatus, when effecting threaded engagement of the slide base  33  through the lower end surface of the lift core  28  and the shaft coupling  35 , the base plate  23  is removed as shown in  FIG. 1  or a hexagonal wrench hole is formed in the base plate  23 , thus making the lift core  28  detachable. Further, since the lift core  28  is vertically movable, and the slide base  33  is horizontally slidable, the assembly operation is rather difficult to perform. Furthermore, in addition to the corrected core rod length set value determined, it is necessary, depending upon the assembly system, to take into consideration the thermal expansion amount due to the temperature rise during molding operation of the rod of the lift core  28 . In this way, the additional setting of the lift core  28  in the longitudinal direction by the user is not only a bother but also involves extreme difficulty in achieving a predetermined machining accuracy.  
         [0028]     The following problems are to be taken into account: (1) when the additional setting of the lift core lower end surface results in an excessive length, the lift core  28  sticks out on the resin molded piece side, resulting in fluctuation due to molding pressure and a damaged product appearance; and (2) when the additional setting results in too small a length, the ejector plate  26  is raised together with the slide base  33  connected to the lift core  28 , and due to displacement of all the components installed in this plate, the design consistency suffers, or the mounting screw  37  may be broken.  
         [0029]     That is, in setting the length of the lift core, problems are involved whether the lift core is too long or too short, and, to determine the setting range, a very severe and difficult operation, which is contingent on the limited clearance between the slide base  33  and the slide path  32 , has to be performed while taking into account the thermal expansion of the lift core  28 .  
         [0030]     Thus, there is a demand for an improvement in terms of the operational efficiency in assembling these components, i.e., the slide base  33  and the lift core  28 .  
       SUMMARY OF THE INVENTION  
       [0031]     The present invention has been made with a view toward solving the above problems in the prior art. It is an object of the present invention to provide an ejector apparatus for use in a resin molding mold, in which, in mounting the lift core, which is to be installed in an inclined state, to the slide base, there is no need for the user to perform any machining operation, making it possible to easily mount the lift core to the slide base regardless of the inclination angle of the lift core.  
         [0032]     The present invention relates to an ejector apparatus and has the following structures in order to solve the above-described technical objects.  
         [0033]     That is, according to the present invention, there is provided an ejector apparatus for forming an undercut portion in a molded piece, characterized by including: a lift core extending through a core that constitutes a resin molding mold and installed so as to be movable in a longitudinal direction of the lift core with respect to a surface of the core; an ejector plate arranged between the core and a base plate so as to be capable of moving up and down, the base plate being arranged below the core while being spaced apart from the core; and an adjustment coupling constructed such that a lower end portion of the lift core is supported so as to be capable of expanding and contracting in a longitudinal direction of the lift core with respect to the ejector plate.  
         [0034]     In this construction, the assembly setting for the rod of the lift core manufactured based on the design value can be effected after assembly within the adjustment range for the adjustment coupling without performing any machining to diminish its length. Further, it is possible to absorb the thermal expansion of the rod of the lift core.  
         [0035]     Also, in the ejector apparatus according to the present invention, the adjustment coupling is provided on an ejector plate side and is equipped with: a support member which has an insertion hole allowing insertion of the lower end portion of the lift core, the insertion hole having a threaded portion, the lower end portion of the lift core inserted from one end of the insertion hole being supported on the ejector plate side; an adjusting screw formed as a hollow cylinder having a threaded portion on its outer peripheral surface and adapted to be threadedly inserted from the other end of the insertion hole of the support member to abut the lower end portion of the lift core; a lock nut serving as a locking means; and a bolt member for fastening together the adjusting screw and the lower end portion of the lift core.  
         [0036]     In this construction, the setting of the thermal expansion amount can be effected based on the reversing amount of the adjusting screw.  
         [0037]     Further, according to the present invention, there is provided an ejector apparatus for forming an undercut portion in a molded piece, characterized by including: a lift core extending through a core constituting a resin molding mold, the lift core being installed so as to be movable obliquely with respect to a surface of the core and in a longitudinal direction of the lift core; an ejector plate arranged between the core and a base plate so as to be capable of moving up and down, the base plate being arranged below the core while being spaced apart from the core; a slide path formed in the ejector plate so as to extend in a direction in which a lower end of the lift core makes relative horizontal movement at a time of ascent and descent of the lift core; a slide base movably arranged in the slide path; a guide bush supported on the slide base so as to be pivotable in an inclining direction of the lift core; and a guide rod that serves to force the slide base to slide horizontally by sliding along the guide bush at a time of ascent and descent of the ejector plate, the ejector apparatus being characterized in that the slide base is equipped with: a slide base main body; and an adjustment coupling constructed such that a lower end portion of the lift core is supported so as to be capable of expanding and contracting in a longitudinal direction of the lift core with respect to the sliding base main body.  
         [0038]     In this construction, the assembly setting for the rod of the lift core manufactured based on the design value can be effected after assembly within the adjustment range for the adjustment coupling without performing any machining to diminish its length. Further, no sliding of the slide base due to the guide rod (release guide) occurs, thus facilitating the assembly.  
         [0039]     Further, in the ejector apparatus according to the present invention, the adjustment coupling is constructed such that the lower end portion of the lift core is supported so as to be pivotable in an inclining direction of the lift core with respect to the sliding base main body in such a way that an inclination angle of the guide rod is the same as an inclination angle of the lift core.  
         [0040]     In this construction, the base main body is equipped with the guide bush pivotable in the inclining direction of the lift core and the adjustment coupling pivotable in the inclining direction, whereby it is possible to forcibly move the ejector plate up and down and forcibly move the slide base in the horizontal direction while maintaining the same inclination angle for the axes of the guide rod and the lift core (i.e., keeping them parallel to each other). That is, the slide base simultaneously receives a horizontal moving force and an upward or downward moving force, and a force which would cause rotation in the slide path is exerted. However, in the present invention, as long as the slide base has been assembled so as to be parallel to the longitudinal direction of the slide path, even if a force that would cause the slide base to rotate within the slide path is exerted, it is possible to keep the slide base parallel to the slide path. Thus, the slide base can always remain parallel to the slide surface of the slide path. As a result, in the present invention, it is possible to completely avoid, with a simple structure, hindrance to sliding, without performing any additional machining on the lift core and the slide base, thus realizing smooth sliding movement.  
         [0041]     Further, according to the present invention, there is provided an ejector apparatus for forming an undercut portion in a molded piece, characterized by including: a lift core extending through a core constituting a resin molding mold, the lift core being installed so as to be movable obliquely with respect to a surface of the core and in a longitudinal direction of the lift core; an ejector plate arranged between the core and a base plate so as to be capable of moving up and down, the base plate being arranged below the core while being spaced apart from the core; a slide path formed in the ejector plate so as to extend in a direction in which a lower end of the lift core makes relative horizontal movement at the time of ascent and descent of the lift core; a slide base movably arranged in the slide path; an adjustment coupling constructed such that a lower end portion of the lift core is supported so as to be capable of expanding and contracting in a longitudinal direction of the lift core and rotatable in an inclining direction of the lift core with respect to the sliding base main body; a guide bush supported on the slide base so as to be pivotable in an inclining direction of the lift core; and a guide rod that serves to force the slide base to slide horizontally by sliding along the guide bush at the time of ascent and descent of the ejector plate, the being characterized in that the adjustment coupling is endowed with an alignment function by which an intersection point where the guide rod and the core cross each other, an intersection point where the guide rod and the guide bush cross each other, an intersection point where the lift core and the core cross each other, and an intersection point where the lift core and the adjustment coupling cross each other, are capable of forming a parallelogram.  
         [0042]     In this construction, it is possible to forcibly move the ejector plate up and down and forcibly move the slide base in the horizontal direction while maintaining the same inclination angle for the intersection points for the guide rod and the lift core (i.e., keeping them parallel to each other). That is, even if the slide base simultaneously receives a horizontal moving force and an upward or downward moving force, it is possible to keep the slide base parallel to the slide path due to the alignment function by which the four intersection points are capable of forming a parallelogram.  
         [0043]     Further, in the above-mentioned ejector apparatus according to the present invention, the adjustment coupling is provided on a slide base side, and is equipped with: a support member which has an insertion hole allowing insertion of the lower end portion of the lift core, the insertion hole having a threaded portion, the lower end portion of the lift core inserted from one end of the insertion hole being supported on the slide base; an adjusting screw formed as a hollow cylinder having a threaded portion on its outer peripheral surface and adapted to be threadedly inserted from the other end of the insertion hole of the support member to abut the lower end portion of the lift core; a lock nut serving as a locking means; and a bolt member for fastening together the adjusting screw and the lower end portion of the lift core.  
         [0044]     In this construction, the setting of the thermal expansion amount can be effected based on the reversing amount of the adjusting screw.  
         [0045]     Further, according to the present invention, there is provided an ejector apparatus, characterized in that the adjusting screw and/or the lock nut has an inner hexagonal wrench hole.  
         [0046]     In this construction, a minimum hole allows insertion of the hexagonal wrench and provides rotation space, thus allowing space saving in terms of the area occupied inside the ejector apparatus itself. Further,a minimum hole allows insertion of a hollow wrench (hexagonal sleeve wrench) and provides rotation space, thus making it possible to achieve a reduction in the size of the ejector apparatus itself.  
         [0047]     Further, the hexagonal wrench, which always undergoes integral threaded insertion in assembling the adjusting screw, is inserted into the hollow of the hollow wrench, thus allowing assembly of two coaxial components (i.e., the adjusting screw and the lock nut). Further, a hexagonal wrench is inserted into the hollow wrench (the hexagonal sleeve wrench), which undergoes integral threaded insertion in assembling the lock nut, thus allowing assembly of two coaxial components.  
         [0048]     Further, according to the present invention, there is provided an ejector apparatus characterized in that respective screws of the adjusting screw and the lock nut exhibit a screw fit length allowing locking without involving any stress relaxation due to fastening pre-tension.  
         [0049]     Further, according to the present invention, there is provided an ejector apparatus characterized in that the adjusting screw and the lock nut each have a hexagonal wrench hole structure for a hollow hexagonal wrench with a round hole for fastening the lock nut and for a hexagonal wrench to be inserted into a hollow of the hollow hexagonal wrench with a round hole to fasten the adjusting screw, and that the base plate and the ejector plate each have a space portion in which the hexagonal wrenches are turned around an axis of the hexagonal wrench hole structure.  
         [0050]     Further, according to the present invention, there is provided an ejector characterized in that the adjustment coupling is equipped with a clearance setting portion that serves to set a predetermined clearance in an axial length of the lift core through reversal of the adjusting screw by an amount corresponding to an angle that can be known from the pitch of the screw portion after abutting the adjusting screw against the lower end portion of the lift core.  
         [0051]     As described above, in the ejector apparatus for a resin molding mold of the present invention, the rod of the lift core prepared based on the design value allows assembly setting within the adjusting range for the adjustment coupling after the assembly, without having to perform any machining to diminish the length thereof. Further, it is possible to absorb the thermal expansion of the rod of the lift core. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0052]     In the accompanying drawings:  
         [0053]      FIG. 1  is a sectional view of a conventional ejector apparatus for a resin molding mold;  
         [0054]      FIG. 2  is an overall perspective view of a resin molding mold equipped with the ejector apparatus as shown in  FIG. 1 ;  
         [0055]      FIG. 3  is an overall perspective view of a slide base constituting the ejector apparatus shown in  FIG. 1 ;  
         [0056]      FIG. 4  is an enlarged perspective view of one forked portion of a slide base main body constituting the slide base shown in  FIG. 3 , in which a shaft coupling is mounted;  
         [0057]      FIGS. 5A and 5B  are explanatory views illustrating the assembling of a lift core of an ejector apparatus;  
         [0058]      FIGS. 6A and 6B  are explanatory views illustrating the assembling of the lift core of an ejector apparatus, of which  FIG. 6A  shows a slide base when a shaft coupling is used, and  FIG. 6B  shows a slide base when no shaft coupling is used;  
         [0059]      FIG. 7  is a sectional view of an ejector apparatus for a resin molding mold according to a first embodiment of the present invention;  
         [0060]      FIG. 8  is a longitudinal sectional view of an adjustment coupling;  
         [0061]      FIGS. 9A through 9D  are diagrams illustrating assembly procedures for an adjustment coupling;  
         [0062]      FIGS. 10A through 10D  are diagrams illustrating assembly procedures for an adjustment coupling;  
         [0063]      FIGS. 11A through 11C  are diagrams illustrating assembly procedures for an adjustment coupling;  
         [0064]      FIGS. 12A through 12   c  are diagrams illustrating assembly procedures for an adjustment coupling;  
         [0065]      FIGS. 13A through 13E  are diagrams illustrating assembly procedures for an adjustment coupling;  
         [0066]      FIG. 14  is a longitudinal sectional view of a slide base and an adjustment coupling;  
         [0067]      FIG. 15  is an explanatory view of an ejector apparatus according to a second embodiment of the present invention, showing an adjustment coupling when no slide base is used;  
         [0068]      FIG. 16  is a longitudinal sectional view of an adjustment coupling according to the second embodiment;  
         [0069]      FIGS. 17A through 17F  are diagrams illustrating assembly procedures for the adjustment coupling of the second embodiment;  
         [0070]      FIGS. 18A through 18D  are diagrams illustrating assembly procedures for the adjustment coupling of the second embodiment;  
         [0071]      FIGS. 19A through 19D  are diagrams illustrating assembly procedures for the adjustment coupling of the second embodiment;  
         [0072]      FIGS. 20A through 20E  are diagrams illustrating assembly procedures for the adjustment coupling of the second embodiment; and  
         [0073]      FIG. 21  is a perspective view of an adjustment coupling according to another embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0074]     Embodiments of an ejector apparatus for a resin molding mold of the present invention will now be described in detail.  
         [heading-0075]     [First Embodiment] 
         [0076]      FIG. 7  shows an ejector apparatus  100  for a resin molding mold according to a first embodiment of the present invention.  
         [0077]     First, a resin molding mold A equipped with this ejector apparatus  100  will be described. As shown in  FIG. 2 , the general construction of this mold is as follows: a core  21   b  is arranged under a mold main body  21   a , with the mold main body  21   a  and the core  21   b  defining a resin molding space  11  ( FIG. 7 ).  
         [0078]     Below the core  21   b , there is arranged a base plate  23 , and, between the core  21   b  and the base plate  23 , there is arranged a spacer  24  on either side, thus defining a chamber  25  between the spacers  24  under the core  21   b . In this chamber  25 , an ejector plate  1  is arranged so as to be vertically movable. Note that  FIG. 7  is a partial sectional view, taken along the line I-I, of the resin molding mold A shown in  FIG. 2 .  
         [0079]     In this resin molding mold A, there is provided a lift core  5  which is passed through an angle setting hole  12  (inclined by an angle K) of the core  21   b  constituting the resin molding mold A to form an undercut portion in a molded piece formed in the above-mentioned resin molding space  11  and which extends obliquely and is longitudinally movable.  
         [0080]     The upper end portion of this lift core  5  functions as a mold portion  5   a  which cooperates with the core  21   b  to form a molded piece, and, by the side of this upper portion, there is formed a protrusion  5   b  for integrally forming an L-shaped flange portion (which also constitutes a part of the undercut portion) in the molded piece. This lift core  5  is passed through a guide hole formed obliquely in the core  21   b , extending downwardly from the core  21   b.    
         [0081]     This lift core  5  is caused to slide vertically in the angle setting hole  12  of the core  21   b  by the ejector apparatus  100 . The ejector apparatus  100  used for this purpose includes the ejector plate  1  composed of two plates  1   a  and  1   b  that are superimposed one upon the other.  
         [0082]     Formed in the lower plate  1   b  of the ejector plate  1  is a slide path  32 , which extends in the direction in which the lower end of the lift core  5  makes relative horizontal movement when it ascends and descends. A slide base  33  is slidably arranged in this slide path  32 , and the lower end portion  5   d  of the lift core  5  is retained by one end portion of the slide base  33  with respect to the sliding direction thereof.  
         [0083]     Further, the ejector apparatus  100 , which raises and lowers the lift core  5 , is equipped with an angular guide rod (hereinafter simply referred to as the guide rod)  8  which is adjacent to the lift core  5  and which is parallel thereto. At either end of this guide rod  8 , there is formed a V-shaped cutout  39 . The upper end portion of the guide rod  8  is supported by engaging one cutout  39  thereof with a pin  40 .  
         [0084]     Incidentally,  FIG. 14  is an overall view of the slide base  33  slidably provided in the above-mentioned ejector plate  1 .  
         [heading-0085]     [Slide Base  33 ] 
         [0086]     This slide base  33  includes a base main body  34  having at its ends with respect to the sliding direction of the slide base  33  forked portions  34   a  and  34   b  that are U-shaped in plan view. In one forked portion  34   a  of this base main body  34 , there is arranged a shaft coupling  36 , and in the other forked portion  34   b , there is arranged a guide bush  36 .  
         [0087]     The lower end portion  5   d  of the lift core  5  is supported by an adjustment coupling  110  so as to be extendable in the longitudinal direction and rotatable in the inclining direction with respect to the base main body  34 .  
         [heading-0088]     [Guide Rod  38 ] 
         [0089]     Further, the guide bush  36  rotatably mounted to the other forked portion  34   b  of the base main body  34  has a passing hole  36   a  extending along an axis perpendicular to the rotation axis of the guide bush  36 , and the above-mentioned guide rod  38  is slidably passed through this passing hole  36   a.    
         [0090]     The guide rod  38 , which is supported at its upper end by a guide holder  39  and which is passed through the passing hole  36   a  of the guide bush  36  of the slide base  33 , extends toward the base plate  23  through a clearance hole  41  formed in the lower plate  26   b , and the cutout  39  at its lower end is engaged with a pin  43  of a holder bush  42  mounted to the base plate  23 , whereby the lower end of the guide rod is supported and secured.  
         [0091]     This holder bush  42  is inserted into an opening  44  formed in the base plate  23  and is secured in position by bolts  45 . As described above, the guide rod  38  is arranged so as to be parallel to the lift core  5 , that is, inclined by the same angle as the lift core  5 . As is apparent from  FIG. 7 , the distance between the core  21   b  and the base plate  23  (that is, the height of the spacers  24  (See  FIG. 2 )) is fixed, so that the setting of the angle of the guide rod  38  depends upon the horizontal positional relationship, that is, the distance, between the pin  40  provided in the guide holder  39  and the pin  43  provided in the holder bush  42 . In  FIG. 7 , the intersection points (axial center points)  39   c  and  4   c  of the guide rod  38  and the intersection points (axial center points)  5   c  and  6   c  of the lift core  5  form a parallelogram.  
         [0092]     By thus forming a parallelogram, it is possible to force the ejector plate  1  to move vertically and to force the slide base  33  to move horizontally, with the axial center points  39   c ,  4   c ,  5   c , and  6   c  of the guide rod  38  and the lift core  5  maintaining the same inclination angle (that is, keeping these components parallel to each other). That is, even when the slide base  33  simultaneously receive horizontal and vertical moving forces and a force to rotate the slide base  33  within the slide path  32  is exerted, the slide base  33  can be kept parallel to the slide path due to the self-alignment function which enables the four axial center points to form a parallelogram.  
         [heading-0093]     [Adjustment Coupling  110 ] 
         [0094]     Next, the adjustment coupling  110  will be described with reference to  FIGS. 7, 8 , and  14 .  
         [0095]     The adjustment coupling  110  is composed of the shaft coupling  6  which is a support member supporting the lower end portion  5   d  of the lift core  5  on the base main body  34  and rotatable in the inclining direction, an adjusting screw  53  abutting the lower end portion  5   d  of the lift core  5 , a bolt member (also referred to as cap bolt)  51  and a washer (spacer collar)  52  for fastening the adjusting screw  53  and the lower end portion  5   d  of the lift core  5  to each other, and a lock nut  55  to be threadedly engaged with the outer peripheral surface of the adjusting screw  53  until it abuts the other end portion of the shaft coupling  6 .  
         [0096]     The shaft coupling  6  arranged in the forked portion  34   a  is rotatably mounted to opposing wall surfaces by means of pins or the like. Further, the shaft coupling  6  is equipped with a through-hole  6   b  in alignment with the center axis thereof which is perpendicular to the rotation axis thereof. A threaded portion is formed in the inner peripheral surface of the through-hole  6   b.    
         [0097]     As shown in  FIG. 8 , the adjusting screw  53  is formed as a hollow cylinder having a threaded portion  53   a  on its outer peripheral surface. Further, the adjusting screw  53 , which is formed as a hollow cylinder, has an inner hexagonal wrench hole  54  in the inner peripheral surface at one end thereof. The adjusting screw  53  is threadedly passed through the through-hole  6   b  of the shaft coupling  6  and abuts the lower end portion  5   d  of the lift core  5 .  
         [0098]     The adjusting screw  53  and the lower end portion  5   d  of the lift core  5  are fastened together by the cap bolt  51  after completion of fine adjustment of the axial length of the lift core  5  (See  FIGS. 13B and 13C ). When fastening with the cap bolt  51 , the spacer collar  52  is inserted between the cap bolt  51  and the adjusting screw  53 . This is done for the purpose of preventing the hexagonal hole of the adjusting screw  53  from being crushed.  
         [0099]     The locknut  55  is formed as a hollow cylinder having a threaded portion  56   a  in an inner peripheral surface thereof. Further, the lock nut  55 , which is formed as a hollow cylinder, has an inner hexagonal wrench hole  56  in the inner peripheral surface at one end thereof.  
         [0100]     Next, the assembly procedures for the adjustment coupling  110  will be described with reference to  FIGS. 9 through 14 .  
         [0101]     As shown in  FIG. 9A , the lock nut  55  is threadedly engaged with an outer peripheral surface of the adjusting screw  53  beforehand. That is, the adjusting screw  53  is screwed into the lock nut  55  from one end thereof until the forward end of the adjusting screw  53  appears at the other end of the lock nut  55  (See  FIG. 9B ). While the lock nut  55  and the adjusting screw  53  provide a sufficient slackness restraining force with normal fastening, when a still firmer fastening is required, the forward screw thread of the adjusting screw  53  is previously saturated with several drops of locking agent.  
         [0102]     As shown in  FIG. 9D , when threadedly passing the adjusting screw  53  through the through-hole  6   b  of the shaft coupling  6 , the forward end of a hexagonal wrench  70  is thereadedly engaged with the inner hexagonal wrench hole  54  from below the ejector apparatus  100 , thus threadely engaging the adjusting screw  53  with the shaft coupling  6 .  
         [0103]     Next, as shown in  FIG. 10A , the hexagonal wrench  70  is temporarily pulled out, and the lift core  5  is inserted into the shaft coupling  6 .  
         [0104]     The hexagonal wrench  70  is brought into a state in which it is inserted into a hollow hexagonal wrench (hexagonal sleeve wrench)  71  (See  FIG. 10B ), and the forward end portion of the hexagonal wrench  70  is engaged with the inner hexagonal wrench hole  54  of the adjusting screw  53 . Next, the adjusting screw  53  is treadedly passed through the shaft coupling  6  again through turning with the hexagonal wrench  70  (See  FIG. 10C ).  
         [0105]     Next, the apex portion of the lift core  5  is pressed axially downwards, and further, the adjusting screw  53  is threadedly passed through the shaft coupling  6  again through turning with the hexagonal wrench  70 . Then, the lower end portion of the lift core  5  abuts the adjusting screw  53 , and when the adjusting screw  53  is further advanced, a “stop” state can be observed in which the slide base  33  abuts the bottom surface of the slide path  2  the clearance of which has been set beforehand (See  FIG. 10D ).  
         [0106]     As shown in  FIG. 11A , while keeping the forward end of the hexagonal wrench  70  inserted into the inner hexagonal wrench hole  54 , the adjusting screw  53  is fixed so that it may not turn with the locknut  55 . Next, the forward end of the hexagonal sleeve wrench  71  is engaged with the inner hexagonal wrench hole  56  of the lock nut  55  and fastened manually. Through this manual fastening, the end surface of the shaft coupling  6  is engaged with the lock nut  55 .  
         [0107]     Next, through reversal and retraction of the adjusting screw  53  by an amount corresponding to an angle that can be known from the screw thread pitch of the adjusting screw  53  (See  FIG. 11B ), it is possible to perform fine adjustment of thermal expansion absorption for the axial length of the lift core  5 . Thus, regarding the axial length of the lift core  5 , its value is determined at the design stage, and fine adjustment thereof is performed by the above-mentioned angle to be known, whereby there is no need to perform gauging at the time of assembly.  
         [0108]     Next, the forward end portion of the hexagonal wrench  70  is inserted into the inner hexagonal wrench hole  54 , and, as shown in  FIG. 12A , the adjusting screw  53  is fixed so as not to turn with the lock nut  55 , and the forward end portion of the hexagonal sleeve wrench  71  is engaged with the inner hexagonal wrench hole  56  of the lock nut  55  to be fastened manually. Next, the hexagonal wrench  70  is drawn out (See  FIG. 12B ), and the hexagonal wrench  70  is passed through the side hole at the end of the hexagonal sleeve wrench  71  to turn the hexagonal sleeve wrench  71 , and the adjusting screw  53  and the lock nut  55  are retightened, with the lock nut  55  being engaged with the end surface of the shaft coupling  6  (See  FIG. 12C ). In this way, the lock nut  55  serves as a so-called W-nut, functioning to effect locking for the adjusting screw  53 . After the completion of the retightening, the hexagonal sleeve wrench  71  and the hexagonal wrench  70  are removed (See  FIG. 13A ).  
         [0109]     Next, after the completion of the fine adjustment of the axial length of the lift core  5 , the adjusting screw  53  and the lower end portion  5   d  of the lift core  5  are fastened together by the cap bolt  51  (See  FIGS. 13B and 13C ). When fastening them with the cap bolt  51 , the spacer collar  52  is inserted between the cap bolt  51  and the adjusting screw  53 . This is done for the purpose of preventing the hexagonal hole of the adjusting screw  53  from being crushed. After the fastening of the adjusting screw  53  and the lift core  5 , the hexagonal wrench  70  is removed to complete the assembly of the adjustment coupling  110 .  
         [0110]     Next, the operation of the ejector apparatus  100  for the resin molding mold A of the first embodiment will be described.  
         [0111]     After forming a molded piece by using the mold A, the ejector plate  1  is raised. When the ejector plate  1  is raised, a vertical raising force is applied to the lower end portion of the lift core  5  through the slide base  33  arranged in the slide path  32  of the upper and lower plates  1   a  and  1   b.    
         [0112]     However, in this slide base  33 , the guide rod  38  is slidably passed through the guide bush  36  mounted to the base main body  34 , so that, simultaneously with the rise of the slide base  33 , it is forced to move horizontally along the guide rod  38 . The inclination angle of this guide rod  38  is the same as that of the lift core  5 .  
         [0113]     As a result, the slide base  33  simultaneously receive upward and horizontal moving forces and is forced to move along the guide rod  38 . Thus, a longitudinal moving force is imparted to the lift core  5  whose lower end portion  5   d  is firmly attached to the shaft coupling  6  of the slide base  33 , and neither a bending force nor a moment that would generate friction is imparted to the angle setting hole  12  of the core  21   b.    
         [0114]     Conversely, when the ejector plate  1  descends, the slide base  33  is forced to move along the guide rod  38 , whereby a longitudinal pull-down force is imparted to the lift core  5 . As a result, also at the time of descent of the ejector plate  1 , neither a bending force nor a moment for the lift core  5  is generated, so that it is possible to completely avoid friction with the angle setting hole  12 .  
         [0115]     According to the first embodiment, the rod of the lift core  5  produced based on the design value allows assembly setting within the adjustment range for the adjustment coupling  110  without having to perform machining for a reduction in length after assembly. Further, due to the guide rod (release guide)  38 , there occurs no sliding of the slide base  33 , thereby facilitating the assembly.  
         [0116]     Further, according to the first embodiment, the rod of the lift core produced based on the design value allows assembly setting within the adjustment range of the adjustment coupling without having to perform machining for a reduction in length after assembly. Further, thermal expansion of the rod of the lift core can be absorbed.  
         [0117]     Further, according to the first embodiment, the rod of the lift core produced based on the design value allows assembly setting within the adjustment range of the adjustment coupling without having to perform machining for a reduction in length after assembly. Further, due to the guide rod (release guide), there occurs no sliding of the slide base, thereby facilitating the assembly  
         [0118]     Furthermore, according the first embodiment, the setting of thermal expansion amount can be determined by the reversal amount of the adjusting screw.  
         [0119]     Furthermore, according to the first embodiment, a minimum hole allows insertion of the hexagonal wrench and provides rotation space, making it possible to achieve space saving in terms of the area it occupies within the ejector apparatus itself. Further, a minimum hole allows insertion of the hollow wrench (hexagonal sleeve wrench) and provides rotation space, making it possible to achieve a reduction in the size of the ejector apparatus itself.  
         [0120]     Further, in assembling the adjusting screw, the hexagonal wrench is always inserted into the hollow wrench (hexagonal sleeve wrench) for the lock nut for integral threaded insertion, thus allowing assembly of the two coaxial components (i.e., the adjusting screw and the lock nut).  
         [0121]     Furthermore, in the ejector apparatus of the present invention, the adjusting screw and the lock nut are always fitted integrally, so that both have a hexagonal wrench hole structure, coaxially providing a wrench area of minimum rotation space. The hexagonal wrench for the adjusting screw allows fastening through insertion into the hollow hexagonal wrench with a round hole (hexagonal sleeve wrench) for the lock nut, thus needing no socket as in the case of an outer hexagonal screw nor rotation space for a spanner wrench.  
         [0122]     Furthermore, according to the first embodiment, the adjusting screw is once brought into contact with the lower end portion of the lift core and is then reversed by an amount corresponding to an angle that can be known from the screw thread pitch, whereby it is possible to set the requisite clearance (absorption of thermal expansion coefficient) in the lift core length.  
         [0123]     Note that, in the above-described first embodiment the adjustment coupling  110  is designed such that the lower end portion of the lift core  5  is supported on the base main body  34  so as to be pivotable in the inclining direction thereof so that the inclination angle of the guide rod  38  may be the same as that of the lift core  5 . However, the present invention is not restricted to the construction in which the adjustment coupling  110  is supported so as to be pivotable in the inclining direction.  
         [0124]     For example, the present invention also covers a structure as shown in  FIG. 21 , which shows a slide base  33 A having a support member  33 B that is not supported so as to be pivotable in the inclining direction of the lift core  5 , the slide base simply having an insertion hole allowing insertion of the lower end portion of the lift core  5 , with the insertion hole having a threaded portion.  
         [heading-0125]     [Second Embodiment] 
         [0126]     While in the above-described first embodiment the slide path allowing sliding of the slide base is provided in the ejector plate, and there is provided the guide rod that serves to force the slide base to slide horizontally, the present invention also covers a case where there is provided no slide path or guide rod.  
         [0127]     Next, a second embodiment of the present invention, in which there is no slide path or guide rod, will be described with reference to  FIGS. 15 through 20 .  
         [0128]     Unlike the first embodiment, the second embodiment adopts a construction in which a core rod standing vertically on an ejector plate (which corresponds to the lift core of the first embodiment) is caused to move up and down without using any guide rod or slide path (slide base). Therefore, here, a construction in which, unlike the first embodiment, the core rod is caused to move up and down by the ejector plate will be described in detail, and a description of any other construction will be omitted.  
         [0129]      FIG. 15  shows an ejector apparatus  200  for a resin molding mold according to a second embodiment of the present invention.  
         [0130]     As shown in  FIG. 2 , the general construction of a resin molding mold A equipped with this ejector apparatus  200  is as follows: a core  221   b  is arranged under a mold main body  221   a , with the mold main body  21   a  and the core  221   b  defining a resin molding space  211  ( FIG. 15 ).  
         [0131]     In this resin molding mold A, there is provided a core rod  205  which is passed through the core  221   b  constituting the resin molding mold A to form a molded piece formed in the above-mentioned resin molding space  211  and which is longitudinally movable.  
         [0132]     The upper end portion of this core rod  205  functions as a mold portion  205   a  which cooperates with the core  221   b  to form a molded piece. This core rod  205  is passed through a guide hole  221   c  formed in the core  221   b , extending downwardly from the core  221   b.    
         [0133]     This core rod  205  is caused to slide vertically in an guide hole  221   c  of the core  221   b  by the ejector apparatus  200 . The ejector apparatus  200  used for this purpose includes an ejector plate  201  composed of two plates  201   a  and  201   b  that are superimposed one upon the other. The lower end portion  205   d  of the core rod  205  is held between the plates  201   a  and  201   b  through the intermediation of a retainer collar  250 . An adjustment coupling  210  according to the present invention is used in this joint portion.  
         [0134]     As shown in  FIG. 16 , the upper plate  201   a  constituting the ejector plate  201  is equipped with a hole  202   a  for the core rod  205 . Further, there are provided stepped holes  202   b  and  202   c , which are coaxial with the hole  202   a . Of the stepped holes  202   b  and  202   c , the large diameter hole  202   c  is a hole into which the retainer collar  250  is to be inserted. The small diameter hole  202   b  serves as a clearance hole for an adjusting screw  253 .  
         [heading-0135]     [Adjustment Coupling  210 ] 
         [0136]     Next, an adjustment coupling  210  will be described with reference to FIGS.  16  to  20 .  
         [0137]     As shown in  FIG. 16 , the adjustment coupling  210  is composed of an adjusting screw  253  abutting the lower end portion  205   d  of the core rod  205 , a bolt member (also referred to as cap bolt)  251  and a washer (spacer collar)  252  for fastening the adjusting screw  253  and the lower end portion  205   d  of the core rod  205  to each other, and a lock nut  255  to be threadedly engaged with the outer peripheral surface of the adjusting screw  253  until it abuts the other end portion of the retainer collar  250 .  
         [0138]     As shown in  FIG. 17A , the retainer collar  250  is formed as a cylinder the side surface of which exhibits two flat faces formed by cutting. Due to this two-face cutting, the retainer collar  250  makes no axial rotation with in the large diameter hole  202   c . Further, the retainer collar  250  is equipped with a through-hole in alignment with the center axis. A threaded portion  250   a  is formed in the inner peripheral surface of the through-hole.  
         [0139]     The adjusting screw  253  is formed as a hollow cylinder having a threaded portion  253   a  on its outer peripheral surface. Further, the adjusting screw  253 , which is formed as a hollow cylinder, has an inner hexagonal wrench hole  254  in the inner peripheral surface at one end thereof. The adjusting screw  253  is threadedly passed through the through-hole of the retainer collar  250  and abuts the lower end portion  205   d  of the core rod  205  (See  FIG. 16 ).  
         [0140]     The adjusting screw  253  and the lower end portion  205   d  of the core rod  205  are fastened together by the cap bolt  251  after completion of fine adjustment of the axial length of the core rod  205  (See  FIGS. 20B and 20C ). When fastening with the cap bolt  251 , the spacer collar  252  is inserted between the cap bolt  251  and the adjusting screw  253 .  
         [0141]     The locknut  255  is formed as a hollow cylinder having a threaded portion  256   a  in the inner peripheral surface thereof. Further, the lock nut  255 , which is formed as a hollow cylinder, has an inner hexagonal wrench hole  256  in the inner peripheral surface at one end thereof.  
         [0142]     Next, the assembly procedures for the adjustment coupling  210  will be described with reference to  FIGS. 17 through 20 .  
         [0143]     As shown in  FIG. 17B , the lock nut  255  is threadedly engaged with the outer peripheral surface of the adjusting screw  253  beforehand. That is, the adjusting screw  253  is screwed into the locknut  255  from one end thereof until the forward end of the adjusting screw  253  appears at the other end of the lock nut  255  (See  FIG. 17C ). While the lock nut  255  and the adjusting screw  253  provide a sufficient slackness restraining force with normal fastening, when a still firmer fastening is required, the forward screw thread of the adjusting screw  253  is previously saturated with several drops of locking agent.  
         [0144]     As shown in  FIG. 17E , when threadedly passing the adjusting screw  253  through the through-hole of the retainer collar  250 , the forward end of a hexagonal wrench  70  is thereadedly engaged with the inner hexagonal wrench hole  254  from below the ejector apparatus  200 , thus threadely engaging the adjusting screw  253  with the retainer collar  250 .  
         [0145]     Next, as shown in  FIG. 17F , the hexagonal wrench  70  is temporarily pulled out, and the core rod  205  is inserted into the retainer collar  250 .  
         [0146]     The hexagonal wrench  70  is brought into a state in which it is inserted into a hollow hexagonal wrench (hexagonal sleeve wrench)  71  (See  FIG. 18A ), and the forward end portion of the hexagonal wrench  70  is engaged with the inner hexagonal wrench hole  254  of the adjusting screw  253 . Next, the adjusting screw  253  is treadedly passed through the retainer collar  250  again through turning with the hexagonal wrench.  70  (See  FIG. 18B ).  
         [0147]     Next, the apex portion of the core rod  205  is pressed axially downwards, and, further, the adjusting screw  253  is threadedly passed through the shaft coupling  6  again through turning with the hexagonal wrench  70 . Then, the lower end portion of the core rod  205  abuts the adjusting screw  253 , and, when the adjusting screw  253  is further advanced, a “stop” state is to be observed in which the retainer collar  250  abuts the bottom surface of the plate  201  the clearance of which has been set beforehand (See  FIG. 18C ).  
         [0148]     As shown in  FIG. 18D , while keeping the forward end of the hexagonal wrench  70  inserted into the inner hexagonal wrench hole  254 , the adjusting screw  253  is fixed so that it may not turn with the lock nut  255 . Next, the forward end of the hexagonal sleeve wrench  71  is engaged with the inner hexagonal wrench hole  56  of the lock nut  255  and fastened manually. Through this manual fastening, the end surface of the retainer collar  250  is engaged with the lock nut  255 .  
         [0149]     Next, through reversal and retraction of the adjusting screw  253  by an amount corresponding to an angle that can be known from the screw thread pitch of the adjusting screw  253  (See  FIG. 1C ) it is possible to perform fine adjustment of thermal expansion absorption for the axial length of the core rod  205 . Thus, regarding the axial length of the core rod  205 , its value is determined at the design stage, and fine adjustment thereof is performed by the above-mentioned angle to be known, whereby there is no need to perform gauging at the time of assembly.  
         [0150]     Next, the forward end portion of the hexagonal wrench  70  is inserted into the inner hexagonal wrench hole  54 , and, as shown in  FIG. 19B , the adjusting screw  253  is fixed so as not to turn with the lock nut  255 , and the forward end portion of the hexagonal sleeve wrench  271  is engaged with the inner hexagonal wrench hole  256  of the lock nut  255  to be fastened manually. Next, the hexagonal wrench  70  is drawn out (See  FIG. 19C ), and the hexagonal wrench  70  is passed through the side hole at the end of the hexagonal sleeve wrench  71  to turn the hexagonal sleeve wrench  71 , and the adjusting screw  53  and the lock nut  55  are retightened, with the lock nut  255  being engaged with the end surface of the retainer collar  250  (See  FIG. 19D ). In this way, the lock nut  55  serves as a so-called W-nut, functioning to effect locking for the adjusting screw  253 . After the completion of the retightening, the hexagonal sleeve wrench  71  and the hexagonal wrench  70  are removed (See  FIG. 20A ).  
         [0151]     Next, after the completion of the fine adjustment of the axial length of the core rod  205 , the adjusting screw  253  and the lower end portion  205   d  of the core rod  205  are fastened together by the cap bolt  251  (See  FIGS. 20B and 20C ). When fastening them with the cap bolt  251 , the spacer collar  252  is inserted between the cap bolt  251  and the adjusting screw  253 . This is done for the purpose of preventing the hexagonal hole of the adjusting screw  253  from being crushed. After the fastening of the adjusting screw  253  and the core rod  205 , the hexagonal wrench  70  is removed to complete the assembly of the adjustment coupling  210  (See  FIGS. 20D and 20E )