Ejector apparatus

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.

This application claims the benefit of Japanese Application 2003-294404, filed Aug. 18, 2003, the entirety of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

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.

2. Description of the Related Art

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.

FIG. 1schematically shows the construction of the ejector apparatus as disclosed in JP 10-95019 A.

FIG. 1shows a conventional ejector apparatus20, which was created by the present inventor. In the apparatus shown, a slide base33is arranged in a slide path32formed in a vertically movable ejector plate26, and the slide base33is forced to slide as the ejector plate26moves up and down, whereby an appropriate axial operating force is imparted to a lift core28.

FIG. 2shows the overall configuration of a resin molding mold A equipped with this ejector apparatus20. The general construction of this mold is as follows: a core21bis arranged under a mold main body21a, with the mold main body21aand the core21bdefining a resin molding space22(FIG. 1).

Below the core21b, there is arranged a base plate23, and, between the core21and the base plate23, there is arranged a spacer24on either side, thus defining a chamber25between the spacers24under the core21b. In this chamber25, the ejector plate26is arranged so as to be vertically movable. Note thatFIG. 1is a partial sectional view, taken along the line I—I, of the resin molding mold A shown inFIG. 2.

In this resin molding mold A, there is provided a lift core28which is passed through an angle setting hole27(inclined by an angle K) of the core21bconstituting the resin molding mold A to form an undercut portion in a molded piece formed in the above-mentioned resin molding space22and which extends obliquely and is longitudinally movable.

The upper end portion of this lift core28functions as a mold portion28awhich cooperates with the core21bto form a molded piece, and, by the side of this upper portion, there is formed a protrusion28bfor integrally forming an L-shaped flange portion (which also constitutes a part of the undercut portion) in the molded piece.

This lift core28is passed through a guide hole31aformed obliquely in a guide plate31which is fitted into a recess29formed in the lower surface of the core21band which is fastened to the core21bby bolts30, with the lift core28extending downwardly from the core21b.

This guide plate31, which allows smooth longitudinal sliding of the lift core28due to the guide hole31aformed in the guide plate31at a predetermined angle K, functions as a bearing. Since the inclination angle K is determined by the angle setting hole27formed in the core21b, the guide hole31amay be a loose fit or clearance hole.

This lift core28is caused to slide vertically in the angle setting hole27of the core21bby the ejector apparatus20. The ejector apparatus20used for this purpose includes an ejector plate26composed of two plates26aand26bsuperimposed one upon the other.

Formed in the lower plate26bof the ejector plate26is the slide path32, which extends in the direction in which the lower end of the lift core28makes relative horizontal movement when it ascends and descends. The slide base33is slidably arranged in this slide path32, and the lower end portion28dof the lift core28is retained by one end portion of the slide base33with respect to the sliding direction of the lift core28.

Further, the ejector apparatus20, which raises and lowers the lift core, is equipped with an angular guide rod (hereinafter simply referred to as the guide rod)38which is adjacent to the lift core28and which is parallel thereto. At either end of this guide rod38, there is formed a V-shaped cutout39. The upper end portion of the guide rod38is supported by engaging one cutout39thereof with a pin40mounted across a through hole31bformed in the guide plate31.

Incidentally,FIG. 3is an overall view of the slide base33slidably provided in the ejector plate26. This slide base33includes a base main body34having at its ends with respect to the sliding direction thereof forked portions34aand34bthat are U-shaped in plan view. In one forked portion34aof this base main body34, there is arranged a shaft coupling35, and, in the other forked portion34b, there is arranged a guide bush36.

The shaft coupling35arranged in the forked portion34ais rotatably mounted to opposed wall surfaces by means of pins or the like.FIG. 4is an enlarged view of the forked portion34aof the base main body34where the shaft coupling35is mounted.

As is apparent fromFIGS. 1 through 4, formed at the upper end of the shaft coupling35is a recess or seat35afor receiving the lower end portion of the lift core28. Further, the shaft coupling35is equipped with a through-hole35bhaving a central axis perpendicular to the rotation axis of the shaft coupling35and matched with the center line of the recess35amentioned above.

The lower end portion of the lift core28is fitted into the recess35aat the upper end of the shaft coupling35rotatably mounted to one forked portion34aof the base main body34, and the end portion of a bolt37inserted into the through-hole35bfrom the lower end of the shaft coupling35as shown inFIG. 1is threadedly engaged with a tapped hole formed in the lower end surface of the lift core28, whereby the lower end portion of the lift core28is firmly secured to the coupling35.

The guide bush36mounted to the other forked portion34bof the base main body34has a passing hole36aextending along an axis perpendicular to the rotation axis of the guide bush36, and the above-mentioned guide rod38is slidably passed through this passing hole36a.

The guide rod38, which is supported at its upper end by the guide plate31and which is passed through the passing hole36aof the guide bush36of the slide base33, extends toward the base plate23through a clearance hole41formed in the lower plate26b, and the cutout39at its lower end is engaged with a pin43of a holder bush42mounted to the base plate23, whereby the lower end of the guide rod is supported and secured.

This holder bush42is inserted into an opening44formed in the base plate23and is secured in position by bolts45. As described above, the guide rod38is arranged so as to be parallel to the lift core28, that is, inclined by the same angle as the lift core28. As is apparent fromFIG. 1, the distance between the core21band the base plate23(that is, the height of the spacers24) is fixed, so that the setting of the angle of the guide rod38depends upon the horizontal positional relationship, that is, the distance, between the pin40provided in the guide plate31and the pin43provided in the holder bush42.

In this conventional ejector apparatus20, when the ejector plate26ascends, the slide base33arranged in the slide path32formed in the ejector plate26also ascends, and a vertical moving force is imparted to the lift core28, whose lower end is connected to the slide base33.

In this process, as a result of its ascent, the slide base33receives a horizontal component of a moving force biasing it to move along the guide rod38, which is mounted at the same inclination angle as the lift core28. As a result, a moving force to push up the lift core28in the longitudinal and axial directions is imparted to the lift core28. Descent of the ejector plate26results in an operation contrary to the above, and the lift core28is pulled down in the longitudinal direction thereof through the slide base33.

Incidentally, the inclination angle K (SeeFIG. 5A) of the lift core28in this ejector apparatus is changeable to an arbitrary angle according to the molded piece22to be obtained, and the inclination angle K of this lift core28is determined by the user who is going to produce the molded piece22by using this ejector apparatus20Thus, as for the longitudinal length of the lift core28, additional setting is required on the part of the user who has purchased the ejector apparatus20.

In view of this, in the conventional ejector apparatus, when fixing the lower end portion28dof the lift core28to the slide base33, (1) the lift core28, prepared in a relatively large length, is temporarily incorporated, and (2) the amount á by which the protrusion28bof the lift core28protrudes on the molded piece side (SeeFIG. 5B) is measured, determining the corrected set value of the rod length of the lift core28from this measurement value á. And, the lift core28has to be pulled out for additional machining to adjust the rod length thereof before incorporating it again.

Further, in the operation of assembling the ejector apparatus, when effecting threaded engagement of the slide base33through the lower end surface of the lift core28and the shaft coupling35, the base plate23is removed as shown inFIG. 1or a hexagonal wrench hole is formed in the base plate23, thus making the lift core28detachable. Further, since the lift core28is vertically movable, and the slide base33is 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 core28. In this way, the additional setting of the lift core28in the longitudinal direction by the user is not only a bother but also involves extreme difficulty in achieving a predetermined machining accuracy.

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 core28sticks 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 plate26is raised together with the slide base33connected to the lift core28, and due to displacement of all the components installed in this plate, the design consistency suffers, or the mounting screw37may be broken.

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 base33and the slide path32, has to be performed while taking into account the thermal expansion of the lift core28.

Thus, there is a demand for an improvement in terms of the operational efficiency in assembling these components, i.e., the slide base33and the lift core28.

SUMMARY OF THE INVENTION

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.

The present invention relates to an ejector apparatus and has the following structures in order to solve the above-described technical objects.

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.

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.

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.

In this construction, the setting of the thermal expansion amount can be effected based on the reversing amount of the adjusting screw.

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.

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.

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.

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.

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.

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.

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.

In this construction, the setting of the thermal expansion amount can be effected based on the reversing amount of the adjusting screw.

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.

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.

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.

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.

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.

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.

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.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of an ejector apparatus for a resin molding mold of the present invention will now be described in detail.

FIRST EMBODIMENT

FIG. 7shows an ejector apparatus100for a resin molding mold according to a first embodiment of the present invention.

First, a resin molding mold A equipped with this ejector apparatus100will be described. As shown inFIG. 2, the general construction of this mold is as follows: a core21bis arranged under a mold main body21a, with the mold main body21aand the core21bdefining a resin molding space11(FIG. 7).

Below the core21b, there is arranged a base plate23, and, between the core21band the base plate23, there is arranged a spacer24on either side, thus defining a chamber25between the spacers24under the core21b. In this chamber25, an ejector plate1is arranged so as to be vertically movable. Note thatFIG. 7is a partial sectional view, taken along the line I—I, of the resin molding mold A shown inFIG. 2.

In this resin molding mold A, there is provided a lift core5which is passed through an angle setting hole12(inclined by an angle K) of the core21bconstituting the resin molding mold A to form an undercut portion in a molded piece formed in the above-mentioned resin molding space11and which extends obliquely and is longitudinally movable.

The upper end portion of this lift core5functions as a mold portion5awhich cooperates with the core21bto form a molded piece, and, by the side of this upper portion, there is formed a protrusion5bfor integrally forming an L-shaped flange portion (which also constitutes a part of the undercut portion) in the molded piece. This lift core5is passed through a guide hole formed obliquely in the core21b, extending downwardly from the core21b.

This lift core5is caused to slide vertically in the angle setting hole12of the core21bby the ejector apparatus100. The ejector apparatus100used for this purpose includes the ejector plate1composed of two plates1aand1bthat are superimposed one upon the other.

Formed in the lower plate1bof the ejector plate1is a slide path32, which extends in the direction in which the lower end of the lift core5makes relative horizontal movement when it ascends and descends. A slide base33is slidably arranged in this slide path32, and the lower end portion5dof the lift core5is retained by one end portion of the slide base33with respect to the sliding direction thereof.

Further, the ejector apparatus100, which raises and lowers the lift core5, is equipped with an angular guide rod (hereinafter simply referred to as the guide rod)8which is adjacent to the lift core5and which is parallel thereto. At either end of this guide rod8, there is formed a V-shaped cutout39. The upper end portion of the guide rod8is supported by engaging one cutout39thereof with a pin40.

Incidentally,FIG. 14is an overall view of the slide base33slidably provided in the above-mentioned ejector plate1.

This slide base33includes a base main body34having at its ends with respect to the sliding direction of the slide base33forked portions34aand34bthat are U-shaped in plan view. In one forked portion34aof this base main body34, there is arranged a shaft coupling36, and in the other forked portion34b, there is arranged a guide bush36.

The lower end portion5dof the lift core5is supported by an adjustment coupling110so as to be extendable in the longitudinal direction and rotatable in the inclining direction with respect to the base main body34.

Further, the guide bush36rotatably mounted to the other forked portion34bof the base main body34has a passing hole36aextending along an axis perpendicular to the rotation axis of the guide bush36, and the above-mentioned guide rod38is slidably passed through this passing hole36a.

The guide rod38, which is supported at its upper end by a guide holder39and which is passed through the passing hole36aof the guide bush36of the slide base33, extends toward the base plate23through a clearance hole41formed in the lower plate26b, and the cutout39at its lower end is engaged with a pin43of a holder bush42mounted to the base plate23, whereby the lower end of the guide rod is supported and secured.

This holder bush42is inserted into an opening44formed in the base plate23and is secured in position by bolts45. As described above, the guide rod38is arranged so as to be parallel to the lift core5, that is, inclined by the same angle as the lift core5. As is apparent fromFIG. 7, the distance between the core21band the base plate23(that is, the height of the spacers24(SeeFIG. 2)) is fixed, so that the setting of the angle of the guide rod38depends upon the horizontal positional relationship, that is, the distance, between the pin40provided in the guide holder39and the pin43provided in the holder bush42. InFIG. 7, the intersection points (axial center points)39cand4cof the guide rod38and the intersection points (axial center points)5cand6cof the lift core5form a parallelogram.

By thus forming a parallelogram, it is possible to force the ejector plate1to move vertically and to force the slide base33to move horizontally, with the axial center points39c,4c,5c, and6cof the guide rod38and the lift core5maintaining the same inclination angle (that is, keeping these components parallel to each other). That is, even when the slide base33simultaneously receive horizontal and vertical moving forces and a force to rotate the slide base33within the slide path32is exerted, the slide base33can be kept parallel to the slide path due to the self-alignment function which enables the four axial center points to form a parallelogram.

Next, the adjustment coupling110will be described with reference toFIGS. 7,8, and14.

The adjustment coupling110is composed of the shaft coupling6which is a support member supporting the lower end portion5dof the lift core5on the base main body34and rotatable in the inclining direction, an adjusting screw53abutting the lower end portion5dof the lift core5, a bolt member (also referred to as cap bolt)51and a washer (spacer collar)52for fastening the adjusting screw53and the lower end portion5dof the lift core5to each other, and a lock nut55to be threadedly engaged with the outer peripheral surface of the adjusting screw53until it abuts the other end portion of the shaft coupling6.

The shaft coupling6arranged in the forked portion34ais rotatably mounted to opposing wall surfaces by means of pins or the like. Further, the shaft coupling6is equipped with a through-hole6bin 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-hole6b.

As shown inFIG. 8, the adjusting screw53is formed as a hollow cylinder having a threaded portion53aon its outer peripheral surface. Further, the adjusting screw53, which is formed as a hollow cylinder, has an inner hexagonal wrench hole54in the inner peripheral surface at one end thereof. The adjusting screw53is threadedly passed through the through-hole6bof the shaft coupling6and abuts the lower end portion5dof the lift core5.

The adjusting screw53and the lower end portion5dof the lift core5are fastened together by the cap bolt51after completion of fine adjustment of the axial length of the lift core5(SeeFIGS. 13B and 13C). When fastening with the cap bolt51, the spacer collar52is inserted between the cap bolt51and the adjusting screw53. This is done for the purpose of preventing the hexagonal hole of the adjusting screw53from being crushed.

The locknut55is formed as a hollow cylinder having a threaded portion56ain an inner peripheral surface thereof. Further, the lock nut55, which is formed as a hollow cylinder, has an inner hexagonal wrench hole56in the inner peripheral surface at one end thereof.

Next, the assembly procedures for the adjustment coupling110will be described with reference toFIGS. 9 through 14.

As shown inFIG. 9A, the lock nut55is threadedly engaged with an outer peripheral surface of the adjusting screw53beforehand. That is, the adjusting screw53is screwed into the lock nut55from one end thereof until the forward end of the adjusting screw53appears at the other end of the lock nut55(SeeFIG. 9B). While the lock nut55and the adjusting screw53provide a sufficient slackness restraining force with normal fastening, when a still firmer fastening is required, the forward screw thread of the adjusting screw53is previously saturated with several drops of locking agent.

As shown inFIG. 9D, when threadedly passing the adjusting screw53through the through-hole6bof the shaft coupling6, the forward end of a hexagonal wrench70is threadedly engaged with the inner hexagonal wrench hole54from below the ejector apparatus100, thus threadely engaging the adjusting screw53with the shaft coupling6.

Next, as shown inFIG. 10A, the hexagonal wrench70is temporarily pulled out, and the lift core5is inserted into the shaft coupling6.

The hexagonal wrench70is brought into a state in which it is inserted into a hollow hexagonal wrench (hexagonal sleeve wrench)71(SecFIG. 10B), and the forward end portion of the hexagonal wrench70is engaged with the inner hexagonal wrench hole54of the adjusting screw53. Next, the adjusting screw53is threadedly passed through the shaft coupling6again through turning with the hexagonal wrench70(SeeFIG. 10C).

Next, the apex portion of the lift core5is pressed axially downwards, and further, the adjusting screw53is threadedly passed through the shaft coupling6again through turning with the hexagonal wrench70. Then, the lower end portion of the lift core5abuts the adjusting screw53, and when the adjusting screw53is further advanced, a “stop” state can be observed in which the slide base33abuts the bottom surface of the slide path2the clearance of which has been set beforehand (SeeFIG. 10D).

As shown inFIG. 11A, while keeping the forward end of the hexagonal wrench70inserted into the inner hexagonal wrench hole54, the adjusting screw53is fixed so that it may not turn with the locknut55. Next, the forward end of the hexagonal sleeve wrench71is engaged with the inner hexagonal wrench hole56of the lock nut55and fastened manually. Through this manual fastening, the end surface of the shaft coupling6is engaged with the lock nut55.

Next, through reversal and retraction of the adjusting screw53by an amount corresponding to an angle that can be known from the screw thread pitch of the adjusting screw53(SeeFIG. 11B), it is possible to perform fine adjustment of thermal expansion absorption for the axial length of the lift core5. Thus, regarding the axial length of the lift core5, 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.

Next, the forward end portion of the hexagonal wrench70is inserted into the inner hexagonal wrench hole54, and, as shown inFIG. 12A, the adjusting screw53is fixed so as not to turn with the lock nut55, and the forward end portion of the hexagonal sleeve wrench71is engaged with the inner hexagonal wrench hole56of the lock nut55to be fastened manually. Next, the hexagonal wrench70is drawn out (SeeFIG. 12B), and the hexagonal wrench70is passed through the side hole at the end of the hexagonal sleeve wrench71to turn the hexagonal sleeve wrench71, and the adjusting screw53and the lock nut55are retightened, with the lock nut55being engaged with the end surface of the shaft coupling6(SeeFIG. 12C). In this way, the lock nut55serves as a so-called W-nut, functioning to effect locking for the adjusting screw53. After the completion of the retightening, the hexagonal sleeve wrench71and the hexagonal wrench70are removed (SeeFIG. 13A).

Next, after the completion of the fine adjustment of the axial length of the lift core5, the adjusting screw53and the lower end portion5dof the lift core5are fastened together by the cap bolt51(SeeFIGS. 13B and 13C). When fastening them with the cap bolt51, the spacer collar52is inserted between the cap bolt51and the adjusting screw53. This is done for the purpose of preventing the hexagonal hole of the adjusting screw53from being crushed. After the fastening of the adjusting screw53and the lift core5, the hexagonal wrench70is removed to complete the assembly of the adjustment coupling110.

Next, the operation of the ejector apparatus100for the resin molding mold A of the first embodiment will be described.

After forming a molded piece by using the mold A, the ejector plate1is raised. When the ejector plate1is raised, a vertical raising force is applied to the lower end portion of the lift core5through the slide base33arranged in the slide path32of the upper and lower plates1aand1b.

However, in this slide base33, the guide rod38is slidably passed through the guide bush36mounted to the base main body34, so that, simultaneously with the rise of the slide base33, it is forced to move horizontally along the guide rod38. The inclination angle of this guide rod38is the same as that of the lift core5.

As a result, the slide base33simultaneously receive upward and horizontal moving forces and is forced to move along the guide rod38. Thus, a longitudinal moving force is imparted to the lift core5whose lower end portion5dis firmly attached to the shaft coupling6of the slide base33, and neither a bending force nor a moment that would generate friction is imparted to the angle setting hole12of the core21b.

Conversely, when the ejector plate1descends, the slide base33is forced to move along the guide rod38, whereby a longitudinal pull-down force is imparted to the lift core5. As a result, also at the time of descent of the ejector plate1, neither a bending force nor a moment for the lift core5is generated, so that it is possible to completely avoid friction with the angle setting hole12.

According to the first embodiment, the rod of the lift core5produced based on the design value allows assembly setting within the adjustment range for the adjustment coupling110without 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 base33, thereby facilitating the assembly.

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.

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

Furthermore, according the first embodiment, the setting of thermal expansion amount can be determined by the reversal amount of the adjusting screw.

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.

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).

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.

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.

Note that, in the above-described first embodiment the adjustment coupling110is designed such that the lower end portion of the lift core5is supported on the base main body34so as to be pivotable in the inclining direction thereof so that the inclination angle of the guide rod38may be the same as that of the lift core5. However, the present invention is not restricted to the construction in which the adjustment coupling110is supported so as to be pivotable in the inclining direction.

For example, the present invention also covers a structure as shown inFIG. 21, which shows a slide base33A having a support member33B that is not supported so as to be pivotable in the inclining direction of the lift core5, the slide base simply having an insertion hole allowing insertion of the lower end portion of the lift core5, with the insertion hole having a threaded portion.

SECOND EMBODIMENT

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.

Next, a second embodiment of the present invention, in which there is no slide path or guide rod, will be described with reference toFIGS. 15 through 20.

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.

FIG. 15shows an ejector apparatus200for a resin molding mold according to a second embodiment of the present invention.

As shown inFIG. 2, the general construction of a resin molding mold A equipped with this ejector apparatus200is as follows: a core221bis arranged under a mold main body221a, with the mold main body21aand the core221bdefining a resin molding space211(FIG. 15).

In this resin molding mold A, there is provided a core rod205which is passed through the core221bconstituting the resin molding mold A to form a molded piece formed in the above-mentioned resin molding space211and which is longitudinally movable.

The upper end portion of this core rod205functions as a mold portion205awhich cooperates with the core221bto form a molded piece. This core rod205is passed through a guide hole221cformed in the core221b, extending downwardly from the core221b.

This core rod205is caused to slide vertically in an guide hole221cof the core221bby the ejector apparatus200. The ejector apparatus200used for this purpose includes an ejector plate201composed of two plates201aand201bthat are superimposed one upon the other. The lower end portion205dof the core rod205is held between the plates201aand201bthrough the intermediation of a retainer collar250. An adjustment coupling210according to the present invention is used in this joint portion.

As shown inFIG. 16, the upper plate201aconstituting the ejector plate201is equipped with a hole202afor the core rod205. Further, there are provided stepped holes202band202c, which are coaxial with the hole202a. Of the stepped holes202band202c, the large diameter hole202cis a hole into which the retainer collar250is to be inserted. The small diameter hole202bserves as a clearance hole for an adjusting screw253.

Next, an adjustment coupling210will be described with reference toFIGS. 16 to 20.

As shown inFIG. 16, the adjustment coupling210is composed of an adjusting screw253abutting the lower end portion205dof the core rod205, a bolt member (also referred to as cap bolt)251and a washer (spacer collar)252for fastening the adjusting screw253and the lower end portion205dof the core rod205to each other, and a lock nut255to be threadedly engaged with the outer peripheral surface of the adjusting screw253until it abuts the other end portion of the retainer collar250.

As shown inFIG. 17A, the retainer collar250is formed as a cylinder the side surface of which exhibits two flat faces formed by cutting. Due to this two-face cutting, the retainer collar250makes no axial rotation with in the large diameter hole202c. Further, the retainer collar250is equipped with a through-hole in alignment with the center axis. A threaded portion250ais formed in the inner peripheral surface of the through-hole.

The adjusting screw253is formed as a hollow cylinder having a threaded portion253aon its outer peripheral surface. Further, the adjusting screw253, which is formed as a hollow cylinder, has an inner hexagonal wrench hole254in the inner peripheral surface at one end thereof. The adjusting screw253is threadedly passed through the through-hole of the retainer collar250and abuts the lower end portion205dof the core rod205(SeeFIG. 16).

The adjusting screw253and the lower end portion205dof the core rod205are fastened together by the cap bolt251after completion of fine adjustment of the axial length of the core rod205(SeeFIGS. 20B and 20C). When fastening with the cap bolt251, the spacer collar252is inserted between the cap bolt251and the adjusting screw253.

The locknut255is formed as a hollow cylinder having a threaded portion256ain the inner peripheral surface thereof. Further, the lock nut255, which is formed as a hollow cylinder, has an inner hexagonal wrench hole256in the inner peripheral surface at one end thereof.

Next, the assembly procedures for the adjustment coupling210will be described with reference toFIGS. 17 through 20.

As shown inFIG. 17B, the lock nut255is threadedly engaged with the outer peripheral surface of the adjusting screw253beforehand. That is, the adjusting screw253is screwed into the locknut255from one end thereof until the forward end of the adjusting screw253appears at the other end of the lock nut255(SeeFIG. 17C). While the lock nut255and the adjusting screw253provide a sufficient slackness restraining force with normal fastening, when a still firmer fastening is required, the forward screw thread of the adjusting screw253is previously saturated with several drops of locking agent.

As shown inFIG. 17E, when threadedly passing the adjusting screw253through the through-hole of the retainer collar250, the forward end of a hexagonal wrench70is threadedly engaged with the inner hexagonal wrench hole254from below the ejector apparatus200, thus threadely engaging the adjusting screw253with the retainer collar250.

Next, as shown inFIG. 17F, the hexagonal wrench70is temporarily pulled out, and the core rod205is inserted into the retainer collar250.

The hexagonal wrench70is brought into a state in which it is inserted into a hollow hexagonal wrench (hexagonal sleeve wrench)71(SeeFIG. 18A), and the forward end portion of the hexagonal wrench70is engaged with the inner hexagonal wrench hole254of the adjusting screw253. Next, the adjusting screw253is threadedly passed through the retainer collar250again through turning with the hexagonal wrench.70(SeeFIG. 18B).

Next, the apex portion of the core rod205is pressed axially downwards, and, further, the adjusting screw253is threadedly passed through the shaft coupling6again through turning with the hexagonal wrench70. Then, the lower end portion of the core rod205abuts the adjusting screw253, and, when the adjusting screw253is further advanced, a “stop” state is to be observed in which the retainer collar250abuts the bottom surface of the plate201the clearance of which has been set beforehand (SeeFIG. 18C).

As shown inFIG. 18D, while keeping the forward end of the hexagonal wrench70inserted into the inner hexagonal wrench hole254, the adjusting screw253is fixed so that it may not turn with the lock nut255. Next, the forward end of the hexagonal sleeve wrench71is engaged with the inner hexagonal wrench hole56of the lock nut255and fastened manually. Through this manual fastening, the end surface of the retainer collar250is engaged with the lock nut255.

Next, through reversal and retraction of the adjusting screw253by an amount corresponding to an angle that can be known from the screw thread pitch of the adjusting screw253(SeeFIG. 1C) it is possible to perform fine adjustment of thermal expansion absorption for the axial length of the core rod205. Thus, regarding the axial length of the core rod205, 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.

Next, the forward end portion of the hexagonal wrench70is inserted into the inner hexagonal wrench hole54, and, as shown inFIG. 19B, the adjusting screw253is fixed so as not to turn with the lock nut255, and the forward end portion of the hexagonal sleeve wrench271is engaged with the inner hexagonal wrench hole256of the lock nut255to be fastened manually. Next, the hexagonal wrench70is drawn out (SeeFIG. 19C), and the hexagonal wrench70is passed through the side hole at the end of the hexagonal sleeve wrench71to turn the hexagonal sleeve wrench71, and the adjusting screw53and the lock nut55are retightened, with the lock nut255being engaged with the end surface of the retainer collar250(SeeFIG. 19D). In this way, the lock nut55serves as a so-called W-nut, functioning to effect locking for the adjusting screw253. After the completion of the retightening, the hexagonal sleeve wrench71and the hexagonal wrench70are removed (SeeFIG. 20A).

Next, after the completion of the fine adjustment of the axial length of the core rod205, the adjusting screw253and the lower end portion205dof the core rod205are fastened together by the cap bolt251(SeeFIGS. 20B and 20C). When fastening them with the cap bolt251, the spacer collar252is inserted between the cap bolt251and the adjusting screw253. This is done for the purpose of preventing the hexagonal hole of the adjusting screw253from being crushed. After the fastening of the adjusting screw253and the core rod205, the hexagonal wrench70is removed to complete the assembly of the adjustment coupling210(SeeFIGS. 20D and 20E)