JP2008087399A - Ejector pin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ejector pin removably attached to an ejector plate at a low cost. <P>SOLUTION: The ejector pin 1 is provided with a pin main body 4 having one end 2 and the other end 3, a bolt-shaped base member 5, and a holder 6 installed on the base member 5 and free removably holding the one end 2 or the other end 3 of the pin main body 4. The holder 6 is equipped with split nails 61 divided into four by incising the sleeve 53, a thread part 54 formed on the outer peripheral surface of the sleeve 53, and a fastening nut 62 screwed on the thread part 54. when the pin main body 4 breaks or wears in excess of the service limit, the pin main body 4 can easily be replaced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ejector pin for extruding a molding object molded by a mold from the mold.

  Conventionally, ejector pins (extrusion pins) have been used to extrude a molded object molded in a cavity of a mold from the cavity. 4A and 4B show an ejector pin 40 made of a steel rod having a flat tip 2. The rear end 3 of the ejector pin 40 is formed with a male screw portion 30 that is screwed into the mounting hole 71 of the ejector plate 7, and a hexagonal barrel portion 50 for hooking a spanner or the like is formed in the vicinity thereof.

Patent Document 1 discloses an ejector pin in which a front end is abutted against a workpiece and a flange is formed at a rear end. The ejector pin is attached to the ejector plate in a state where the flange is sandwiched between two steel plates constituting the ejector plate.
Japanese Utility Model Publication No. 57-160851

  The male screw part, the hexagonal body part, or the flange described above is indispensable for attaching the ejector pin to the ejector plate. However, the man-hours required to form these portions on the ejector pins are the cause of raising the manufacturing cost of the ejector pins. For this reason, if the ejector pin is replaced every time the ejector pin is broken or worn, there arises a problem that the running cost of the mold increases.

  Accordingly, an object of the present invention is to provide an ejector pin that is detachably attached to an ejector plate at a low cost.

  The present invention relates to an ejector pin for extruding an object to be formed by a mold from the mold in accordance with an operation of an ejector plate, wherein one end is directed in a direction in which the object is extruded and the other end is the ejector. A pin main body facing the plate, a base member joined to the ejector plate, and a holder provided on the base member for detachably holding the other end of the pin main body.

  Further, the holder protrudes from the base member in the direction in which the molding is pushed out, and a split claw in which a notch is provided in a sleeve into which the pin body is removably inserted, and an outer peripheral surface of the sleeve And a fastening nut having a throttle hole screwed into the threaded portion and having a taper that is in sliding contact with the split claw and provided on the inner surface, and the fastening nut is fastened to the threaded portion. Thus, the split claw is squeezed according to the taper of the throttle hole.

  According to the ejector pin according to the present invention, a holder is provided on the base member joined to the ejector plate, and the pin body can be detachably gripped on the holder, so that when the pin body is broken or worn beyond the limit of use. Such a pin body can be easily replaced. In addition, when replacing the pin main body, it is not necessary to remove the base member from the ejector plate, so that the work can be performed efficiently.

  Also, if a problem such as wear of one end of the pin body occurs, the direction of one end and the other end of the pin body is reversed, one end of the pin body is held by a holder, and the other end of the pin body is pushed out by the molding. Turn in the direction to be. In this state, if the pin body moves in the direction of extruding the molding object together with the ejector plate, the other end of the pin body comes into contact with the molding object, and the molding object can be extruded from the mold. Accordingly, after one end of the pin body is worn, the same pin body can be used until the other end is worn, so that the service life of the pin body can be extended.

  In addition, the pin body applicable to the ejector pin only needs to be a rod body having a predetermined mechanical strength, and it is not necessary to form a threading or a flange as in the conventional case, so that the unit price of the pin body can be reduced. Can do. For this reason, even if the replacement of the pin body is repeated, the running cost of the mold can be minimized.

  In addition, since the ejector pin is tightened with a fastening nut on the threaded portion of the sleeve, the split claw is squeezed according to the taper of the throttle hole, so that the pin body fitted in the sleeve can be firmly joined to the base member. . Further, since the pin body can be removed from the sleeve simply by loosening the fastening nut, the replacement of the pin body can be performed quickly and easily.

  An ejector pin 1 shown in FIG. 1 includes a round bar-shaped pin body 4 having one end 2 and the other end 3, a bolt-shaped base member 5, and the other end 3 of the pin body 4 provided on the base member 5. And a holder 6 for gripping. FIG. 2 shows an example in which the ejector pin 1 is attached to an ejector plate 7 equipped in some type.

  The terms “one end 2” and “the other end 3” of the pin body 4 are designations for relatively distinguishing both ends of the pin body 4. The cross section and the outer diameter of each of the one end 2 and the other end 3 of the pin body 4 are formed to be equal to each other as shown in FIG. Further, the cross section of the pin body 4 is not limited to a circle but may be an ellipse or a polygon. The base member 5 is formed by integrally forming a shaft portion 51 with a male screw cut and a hexagonal head portion 52 that can be hooked with a spanner or the like. The base member 5 is formed in the mounting hole 71 of the ejector plate 7 shown in FIG. By fastening the portion 51, it is fixed to the ejector plate 7. A sleeve 53 is formed integrally with the head 52 of the base member 5 so as to protrude to the opposite side of the shaft 51.

  As described above, in a state where the base member 5 is fixed to the ejector plate 7, the sleeve 53 has its tip directed in the direction indicated by the arrow P. The arrow P coincides with the direction in which the workpiece is extruded from the mold according to the operation of the ejector plate 7. A taper is provided on the outer peripheral surface in the vicinity of the tip of the sleeve 53 so that the outer diameter becomes smaller in the direction indicated by the arrow P. The inner diameter of the sleeve 53 is such a size that the one end 2 or the other end 3 of the pin body 4 can be removably inserted by an operator.

  The holder 6 is screwed into the split claw 61 divided into four parts by providing cuts at a pitch of 90 ° in the sleeve 53, the screw part 54 formed on the outer peripheral surface of the sleeve 53, and the screw part 54 of the sleeve 53. And a fastening nut 62. The fastening nut 62 has a screw hole 63 in which an internal thread is cut. A taper is provided on the inner surface in the vicinity of the mouth edge 64 directed in the direction indicated by the arrow P of the screw hole 63 so that the inner diameter is reduced toward the mouth edge 64. This portion 65 becomes a throttle hole described below.

  In order to hold the pin body 4 with the holder 6, first, the pin body 4 is placed in a posture in which one end 2 thereof is pointed by the arrow P, and the other end 3 of the pin body 4 is fitted into the sleeve 53. Subsequently, when the fastening nut 62 is fastened to the thread portion 54 of the sleeve 53, the fastening nut 62 moves toward the head 52 of the base member 5 in this process. In other words, the four split claws 61 move relatively toward the mouth edge 64 of the screw hole 63. Thereby, the space | interval of the split claws 61 which oppose each other on both sides of the pin main body 4 among the split claws 61 divided into four is gradually narrowed according to the taper of the aperture hole 65. Further, when the fastening nut 62 is strongly tightened to the threaded portion 54 of the sleeve 53, the other end 3 of the pin body 4 is firmly fixed to the base member 5. On the contrary, if the fastening nut 62 is loosened with a spanner or the like, the other end 3 of the pin body 4 can be easily extracted from between the split claws 61 divided into four.

  According to the ejector pin 1 described above, the other end 3 of the pin body 4 can be detachably held by the holder 6, so that when the pin body 4 is broken or worn beyond the use limit, such a pin body 4 can be easily replaced with a new one. In addition, when a problem such as wear of the one end 2 of the pin body 4 occurs, the other end 3 of the pin body 4 is pointed by the arrow P by reversing the direction of the one end 2 and the other end 3 of the pin body 4. The one end 2 of the pin body 4 is gripped by the holder 6 in the above-described manner. In this state, if the pin main body 4 moves together with the ejector plate 7 in the direction indicated by the arrow P, the other end 3 of the pin main body 4 comes into contact with the molding object, and the molding object can be pushed out of the mold. Therefore, after the one end 2 of the pin body 4 is worn, the same pin body 4 can be used until the other end 3 is worn, so that the service life of the pin body 4 can be extended.

  Moreover, the pin body 4 applicable to the ejector pin 1 is not particularly limited in terms of its material, shape, dimensions, etc., as long as it is a rod body having a predetermined mechanical strength. Etc. are not necessary. While manufacturing a conventional ejector pin requires about 1,000 [yen / piece], the pin body 4 can be manufactured at about 100 [yen / piece]. Thus, since the manufacturing cost of the pin body 4 can be significantly reduced, the running cost of the mold can be minimized even if the pin body 4 is repeatedly replaced.

  It should be noted that the present invention can be implemented in variously modified, modified, or modified forms based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

  For example, as shown in FIG. 3, a plurality of split claws 61 may be formed integrally with the fastening nut 62. In this case, the circumferential groove 66 is formed around the split claw 61, while the cylindrical projection 67 is formed on the head 52 of the base member 5, and the inner periphery of the circumferential groove 66 is formed on the outer peripheral surface of the cylindrical projection 67. A screw portion 54 that can be screwed onto the surface is formed. A taper is provided on the inner side of the cylindrical convex portion 67 so that the inner diameter is reduced toward the inner side. This part becomes the throttle hole 65.

  When the fastening nut 62 is fastened to the threaded portion 54 of the cylindrical convex portion 67, the fastening nut 62 moves toward the head 52 of the base member 5 in this process. The interval between the split claws 6 facing each other with the main body 4 interposed therebetween is narrowed according to the taper of the throttle hole 65. As a result, the pin body 4 is fixed to the base member 5.

  Moreover, the structure which attaches the base member 5 to the ejector plate 7 is not limited at all. For example, the base member 5 may be directly welded to the ejector plate 7. Alternatively, when the ejector plate is a laminate of two steel plates, a flange may be formed on the shaft portion 51 of the base member 5, and this flange may be sandwiched between the two steel plates.

  The present invention is a technique that can be applied to all types of molds in addition to a core mold, a compression mold, or a plastic injection mold.

The disassembled perspective view of the ejector pin which concerns on embodiment of this invention. Sectional drawing which shows the example which attached the ejector pin which concerns on embodiment of this invention to the ejector plate. The side view which fractured the ejector pin concerning other embodiments of the present invention. (A) is sectional drawing which shows the example which attached the conventional ejector pin to the ejector plate, (b) is the sectional view on the AA line.

Explanation of symbols

1: Ejector pin 2: One end 3: Other end 4: Pin body 5: Base member 6: Holder 7: Ejector plate 53: Sleeve 54: Screw part 61: Split claw 62: Fastening nut 65: Restriction hole

Claims (2)

An ejector pin for extruding a molding object molded by the mold from the mold according to the operation of the ejector plate,
A pin main body with one end facing in the direction in which the molding is pushed and the other end facing the ejector plate, a base member joined to the ejector plate, and the other end of the pin main body provided on the base member An ejector pin comprising a holder that can be freely gripped. The holder protrudes in a direction in which the molding is pushed out from the base member, and a split claw provided with a notch in a sleeve into which the pin body is removably inserted; and
A threaded portion formed on the outer peripheral surface of the sleeve;
A fastening nut having a throttle hole screwed into the threaded portion and provided with a taper in sliding contact with the split claw;
2. The ejector pin according to claim 1, wherein when the fastening nut is fastened to the threaded portion, the split claw is squeezed according to a taper of the throttle hole.

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