JPH0574820U - Die plate mounting structure - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a die plate mounting structure capable of easily and securely mounting a resin tie bar bush to a die plate without using accessories such as a retainer ring. [Constitution] A concave groove is formed in the inner peripheral surface (33) of the insertion hole (32) of the die plate (3) provided with the molding die in the circumferential direction.
(34) is formed, on the other hand, the resin-made tie bar bush (1) fitted into the tie bar (4) is provided with a concave groove (34) of the die plate (3) on the outer peripheral surface in the middle of its length direction. Forming a convex portion (2) having a substantially saw-tooth cross section to be engaged, and a concave groove (34) and a convex portion (2)
The die plate (3) is attached to the tie bar (4) so as to engage with.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure for attaching a die plate provided with a molding die to a tie bar.

[0002]

[Prior Art]

 The molds of various molding machines such as an injection molding machine are usually provided on a fixed die plate and a movable die plate to be opened and closed. These die plates are inserted into and supported by the tie bars, and in particular, the movable die plates are configured to slide on the tie bars so as to be able to move toward and away from the fixed die plate. Each of the die plates is usually inserted and fixed to a tie bar bush which is slidably inserted in the tie bar.

By the way, making the tie bar bush oil-free has been solved by making the bush a synthetic resin. However, when a resin tie bar bush is attached to the die plate, if it is squeezed like a metal bush, it will be deformed at the time of driving, and if it is cooled and fitted, it will not completely return to the original size once it contracts due to the nature of the resin, Since the holding force of the bush is very weak because the longitudinal elastic modulus is smaller than that of metal, as shown in Fig. 6, the end of the tie bar insertion hole (b) of the moving die plate (a) is It was necessary to fit the tie bar bush (d) in the shape of which the flange (c) was provided in the opening, and then press the flange (c) from the outside with the retainer ring (e).

[0004]

[Problems to be solved by the device]

 An object of the present invention is to provide a die plate mounting structure in which a resin tie bar bush can be easily and surely mounted on a die plate without using accessories such as a retainer ring.

[0005]

[Means for Solving the Problems]

 Thus, according to the invention of “Claim 1” of the present application, the “die plate provided with the molding die is attached to the tie bar (4) through the resin tie bar bush fitted in the tie bar (4). A mounting structure of a die plate which is inserted and slidably supported, wherein a concave groove (34) is formed in a circumferential direction on an inner peripheral surface (33) of the insertion hole (32) of the die plate (3). At the same time, the resin tie bar bush (1) has, on its outer peripheral surface in the longitudinal direction, a convex portion (2) having a substantially saw-shaped cross section that engages with the concave groove (34) of the die plate (3). ) Is formed, and a die plate mounting structure ”is provided.

In the mounting structure of the present invention, the recessed groove (34) of the inner peripheral surface (33) of the insertion hole of the die plate may be provided in the shape of a ring that makes one round in the circumferential direction, or may be interrupted in the middle. It may be provided in an arc shape. The cross-sectional shape of the concave groove (34) is preferably a rectangular cross-section having a width and depth substantially equal to the substantially saw-tooth shape of the convex portion (2) provided on the resin tie bar bush (1) described later. It can be mentioned as a bad thing.

In the mounting structure of the present invention, the convex portion (2) provided on the resin tie bar bush (1) has a substantially saw-tooth cross section which engages with the concave groove (34) provided on the die plate (3). It is provided in a shape. The section having a substantially saw-toothed shape means that one side has an inclined surface (21) for smoothly inserting and inserting the die plate, and the other side has a concave groove (34) after being engaged with the concave groove (34). ) It means a shape having an inclined surface or a vertical surface (22) that does not slip out of it.

In the present invention, a plurality of resin tie bar bushes (1) may be used for one tie bar (4). In this case, it is preferable that the convex portions (2) provided in each tie bar bush (1) and having a substantially sawtooth cross section are provided so as to face each other.

As the resin constituting the resin tie bar bush (1), a resin having a friction coefficient as small as possible is preferably selected, and examples thereof include polyacetal resin and PPS resin.

[0010]

[Action]

 According to the present invention, when the die plate (3) is inserted into the resin tie bar bush (1) fitted in the tie bar (4), it is provided on the outer peripheral surface of the resin tie bar bush (1). The inner peripheral surface (33) of the insertion hole of the die plate (3) slides along one inclined surface (21) of the convex section (2) with a substantially saw-tooth section, and eventually the convex section (2) is inserted. It fits and engages with the concave groove (34) of the hole inner peripheral surface (33). After the engagement, the other surface (22) of the convex portion (2) having a substantially saw-tooth cross section is firmly in contact with the wall surface of the concave groove (34) and does not slide out, which causes the resin tie bar bush (1). And the die plate (3) will be fixed.

[0011]

【Example】

 Hereinafter, the present invention will be described in detail according to illustrated embodiments, but the present invention is not limited thereto. Embodiment 1 FIG. 1 is a schematic side view of a main part of a mold opening / closing device to which the present invention is applied, and FIG. 2 is an enlarged view of part A of FIG. The mold opening / closing device (10) of FIG. 1 includes a fixed die plate (5) having a fixed mold (51) attached thereto, a movable die plate (3) having a movable mold (31) attached thereto, and the movable die plate. It is mainly composed of four tie bars (4) into which (3) is slidably attached and a toggle mechanism (6) for driving the moving die plate (3). A roller (7) mechanism is attached to both sides of the lower part of the moving die plate (3) to facilitate sliding by the toggle mechanism (6). In the mold opening / closing device (10), the moving die plate (3) is attached to each tie bar (4) by enlarging the part A in the same figure as shown in FIG. ) Is done through.

As shown in FIG. 3, the resin tie bar bush (1) is provided with a flange-shaped convex portion (2) near the end of the outer peripheral surface. This convex portion (2) is formed in a saw-tooth shape in cross section, and one is formed on the tapered surface (21) and the other is formed on the vertical surface (22) from the ridge line connecting the tops. .. When forming the convex portion (2), it is preferable that the degree of protrusion (that is, a in the figure) is about 0.3 to 0.5% of the outer diameter. The size of the portion shown in FIG. 5B is set appropriately, but if it is too short, the taper surface (21) becomes steep, making it difficult to insert the die plate (3). The resin tie bar bush (1) is preferably made of polyacetal resin, PPS resin or the like as a raw material, and the coefficient of friction can be set to about 0.02 to 0.03, and the sliding property on the tire (4) is very high. It will be good.

On the other hand, as shown in FIG. 4, each corner of the moving die plate (3) is provided with an insertion hole (32) into which the resin tie bush (1) is inserted. The diameter of this insertion hole is adjusted to be approximately the same as the outer diameter (L2) of the resin tie bar bush (1). On the inner peripheral surface (33) of the insertion hole (32), a concave groove (34) having a rectangular cross section is formed in a ring shape in the circumferential direction. The depth of the concave groove (34) is preferably about 0.4 to 0.7% of the diameter of the insertion hole (= outer diameter L2 of the resin tie bar bush). For other dimensions, refer to the one shown in the figure.

When the resin tie bar bush (1) configured as described above is inserted into each insertion hole (32) of the moving die plate (3) from the taper surface (21) side of the convex portion (2), The tapered surface (21) having a very small friction coefficient slides smoothly on the inner peripheral surface (33) of the insertion hole and fits into the concave groove (34) formed on the inner peripheral surface (33), and the moving die plate ( Resin tie bush (1) is fixed to 3). Then, by inserting the moving die plate (3) to which the resin tie bar bush (1) is fixed into the tie bar (4), the attachment of the moving die plate (3) to the tie bar (4) is completed, The structure is shown in FIG. In the engaged state shown in the figure, when sliding in the (→) direction of FIG. 1, the vertical surface (22) of the convex portion (2) is firmly in contact with the side surface of the concave groove (34) so that the sliding surface does not slide. Therefore, the resin tie bar bush (1) and the moving die plate (3) are not separated.

Embodiment 2 Another example of the mounting structure of the present invention is shown in FIG. In the structure shown in the figure, two resin tie bar bushes (1) are inserted into each insertion hole (32) provided in the movable die plate (3). That is, the length of the resin tie bar bush (1) is about half that of the first embodiment, and the taper surfaces (21) and (21) of the convex portions (2) and (2) face each other. The movable die plate (3) is provided with each insertion hole (32), and the two inner grooves (33) of the movable die plate (3) are provided with two concave grooves (34) (34). Except for this, the configuration is similar to that of the first embodiment.

In the case of such a mounting structure, since the vertical surfaces (22) of the convex portions (2) alternately serve as stoppers in any sliding direction, the moving die plate (3) and the resin are not in contact with each other. The detachment from the tie bar bush (1) made can be prevented more effectively.

[0017]

[Effect of the device]

 According to the present invention, a resin tie bar bush can be attached to a movable die plate inexpensively, easily and securely without using a conventional accessory such as a retainer ring. Further, since the retainer ring is not used, it is possible to mount the molds with the tie bar spacing as large as possible without narrowing the mold mounting area of the die plate as in the conventional case.

[Brief description of drawings]

FIG. 1 is a schematic side view of a main part of a mold opening / closing device to which a mounting structure of the present invention is applied.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a schematic sectional view of an example of a resin tie bar bush used in the present invention.

FIG. 4 is a schematic sectional view of a main part of a moving die plate.

FIG. 5 is a schematic cross-sectional view of a main part of another example of the mounting structure of the present invention.

FIG. 6 is a schematic cross-sectional view of a main part of a mounting structure of a conventional die plate and a resin tie bar bush.

[Explanation of symbols]

(1)… Resin tie bar bush (2)… Convex part (3)… Moving die plate (4)… Tie bar (5)… Fixed die plate (6)… Toggle mechanism (7)… Roller mechanism (10)… Mold opener (21)… Tapered surface (22)… Vertical surface (32)… Insertion hole (33)… Inner peripheral surface (34)… Concave groove

Claims (1)

[Scope of utility model registration request] 1. A die plate mounting structure for slidably supporting a die plate provided with a molding die through the tie bar via a resin tie bar bush fitted in the tie bar. A groove is formed in the inner peripheral surface of the insertion hole of the die plate in the circumferential direction, and the resin tie bar bush is engaged with the groove of the die plate on the outer peripheral surface in the middle in the length direction. A die plate mounting structure in which a convex portion having a substantially sawtooth cross section is formed.