JPH0486206A - Compression mold - Google Patents

Abstract

PURPOSE:To make it possible to economically realize high quality and dimensionailly accurate joining molding of large-sized crosslinked molding material by a method wherein vacuumizing means, which vacuumizes a joining molding part, are provided adjacent to the joining molding part of the molding grooves of molds, which are vertically divided. CONSTITUTION:Molding materials M, which are joining molded together at a joining molding part 2a, are charged at the central part of the molding groove 2A of the bottom force 10A of a mold 10. In succession, the forces are clamped. At this time, vacuumizing is started through deaerating holes 7 and 8 of deaerating parts 6 and 6 and pipe 9. When sealing members provided at the side peripheries of the deaerating parts 6 are brought into contact with a top force 10B by mold clamping, deaeration is performed intensively on the molding groove 2A side so as to vacuumize the joining molding part 2a. Molding materials M, which are softened by being heated up for the predetermined period of time and then compressed, flow after the shape of the molding groove 2A and is crosslinked and molded. At this time, since the air entrapped in the joining molding part 2a and the gas developed from the molding materials M at high temperature crosslinking are efficiently vacuumized by a deaerating means A, the molding materials M fully flow after the molding groove 2A and then pressed, resulting in preventing voids, buckling and poor external appearance from developing.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a compression molding tool for economical pressure molding of doll waterproof frames, O-rings, etc. made of cross-linked materials such as rubber by joint molding. It's about type.

[Conventional technology]

Conventionally, in order to economically mold large waterproof frames, O-rings, etc. using relatively small molds, each end of a cross-linked molded material was divided into multiple preformed parts as shown in Figure 3. The parts are overlapped at a connecting molding part in the middle of the molding groove of a compression molding mold, and are integrated by pressure and heat molding to form a large crosslinked molded product.

FIG. 3 shows an example of a conventional compression molding die for performing joint molding of rubber molded materials.

In Fig. 783, 1 is a compression molding mold (hereinafter referred to as a mold), IA is a mold 1, IB is also a mold 1, 2 is a molding groove of gold Qljl, and 3 is a surplus. A relief groove of the comb, 4 a mounting bolt hole for fixing the mold 1 to a compression molding press (not shown), and 5 a kite pin. M is a rubber molding phase which is preformed and jointly molded in the mold 1.

In configurations north of this point, when performing joint molding, the rubber molded material (
Hereinafter referred to as molding material. ) M is pressed into the molding groove 2a in the center of the molding groove 2a of the lower mold IA of the mold 1 divided on the plate, overlapping as shown in the CC cross-sectional view of FIG. 4, and loading. Alternatively, it is loaded into the molding groove 2 by abutting against the stepped joints, and then pressurized and heated in the mold 1. At this time, the molding material M
The joint molding part 2a becomes in a fluid state at the stage of crosslinking, and is pressurized by the tightening compression of the lower mold IA and the upper mold IB, and the excess molding material in the joint molding part 2a of the molding material M flows into the relief groove 3. As it overflows, pressure is also applied in the axial direction of the molded material M, that is, in the direction of the arrow D-D in FIG. 1'', the molded material M moves toward both ends of the mold L, causing positional deviation.

[Problem to be solved by the invention]

In the conventional example, the rubber molding material M is jointly molded as described above, and during the joint molding, the rubber molding material M becomes a fluid state due to pressure and heating in the joint molding section 2a, and the axis of the molding groove 2 Not only does this cause misalignment in the direction, the dimensions of the molded product vary, and the dimensional accuracy decreases, but also the quality of the joint molded product is affected due to insufficient pressure in the joint molding part 2a and the generation of bubbles and backlint due to the gas generated during crosslinking. There were problems such as a decrease in

This invention was made in order to solve the problems of the conventional methods as described above, and is a compression molding method that can economically perform bond molding of large cross-linked molded materials with high quality and size grain size. The purpose is to provide molds.

[Failure to solve the problem]

Therefore, the compression molding mold according to the present invention is a compression molding mold that connects and molds mutual ends of a crosslinked molded material, and includes:
- The above objective is achieved by providing a vacuum degassing means for depressurizing and deaerating the joint molding part adjacent to the joint molding part of the molding groove of the mold that is divided into F. be.

[Effect]

In the compression molding mold according to the present invention configured as described above, in the connecting molding part of the molding groove of the mold which is divided under L,
When the ends of the cross-linked molded material are connected and molded, the ends of the cross-linked molded material become fluid due to the pressure and heat of the compression mold. At this time, since the joint molding part of the molding groove is degassed under reduced pressure by the vacuum degassing means, the air in the joint molding part and the gas generated during crosslinking are quickly degassed, and the joint molding part is brought to an extremely low pressure. This promotes the flow of the cross-linked molding material into the molding groove, suppressing residual air and the generation of bubbles and backlint, and also preventing the occurrence of misalignment of the cross-linked molding material in the molding groove in the axial direction. It is effectively suppressed by the pressure difference with the external pressure.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

(Structure) FIG. 1 is an exploded perspective view of a compression molding die showing an embodiment of the present invention, and FIG. 2 is the same (an enlarged sectional view of the section BB).

In FIGS. 1 and 2, 2A and 2B are molding grooves with a semicircular cross-sectional shape, and these molding grooves 2A and 2B are the lower mold 10A of the compression molding mold (hereinafter referred to as the mold) 10.
- The lower mold 2A and the upper mold 2B are provided with the same desired curvature R with respect to the dividing surface of the mold 10B.

Escape grooves 3A, 3A for surplus cross-linked molding material (hereinafter referred to as molding material) M are provided on both sides of the molding groove 2A of the upper mold 10A, and the molding groove 2A located in the center of the lower mold 10A is connected. Rectangular reduced pressure degassing parts (hereinafter referred to as degassing parts) 6, 6 are provided on both sides of the part 2a with partition walls W at a desired interval interposed therebetween. Depressurization deaeration holes 7, 7 are bored from the outer bottom surfaces of the degassing parts 6, 6 to a predetermined depth, and a depressurization hole 7.7 is made in communication with the vacuum deaeration holes 7.7 to reach one side of the upper mold 10A. Deaeration holes (hereinafter referred to as deaeration holes).

) 8 is provided, and this deaeration hole 8 is connected to a vacuum pump (not shown) by a reduced pressure deaeration piping (hereinafter referred to as piping) 9.

In addition, the deaeration parts 6, 6, the molding groove 2A and the relief groove 3A,
3A is separated by a partition wall W having a desired width, and the other peripheral side of the degassing section 6 is separated by a groove 11 at a desired interval.
is provided on the king side, and a seal part old S with an O-shaped cross section made of a heat-resistant rubber elastic material such as fluororubber or silicone rubber is attached to this dovetail groove 11, except for the side surface with respect to the molding groove 2A. It has a structure that prevents air from being sucked into the deaeration section 6 during continuous molding from the three circumferential sides including the relief groove 3A, and thereby the depressurization deaeration function during depressurization is performed on the molding groove 2A. It is configured to be concentrated in the joint forming part 2a.

And a degassing section 6. Deaeration hole 7.8, piping 9, and a vacuum pump (not shown) constitute depressurization deaeration means A.

(motion) The operation will be explained based on the above configuration.

First, the molding material M to be jointly molded in the center part of the molding groove 2A of the toe mold 10A of the mold 10, that is, in the joint molding part 2a, is loaded into the molding groove 2A with a predetermined overlap, as in the conventional example. Subsequently, a pressure molding press (not shown) is operated to clamp the mold. At this time, a limit switch (not shown) is activated, a vacuum pump (not shown) is driven, and vacuum degassing is started from the degassing sections 6, 6 via the degassing holes 7.8 and the piping 9. Due to mold clamping, the seal member S around the side of the degassing section 6 is attached to the upper mold 1.
When it comes into contact with 0B, degassing is concentrated on the molding groove 2A side, and the joint molding part 2a is degassed and depressurized. When the molded member M is pressurized and heated for a predetermined period of time, the heated and softened molding material M flows following the shape of the molding groove 2A and is crosslinked. At this time, the air brought into the joint molding section 2a and the gas generated from the molding phase M during high-temperature crosslinking are efficiently depressurized and degassed by the depressurizing degassing means A, so that the molding material M sufficiently flows following the molding a2A. This prevents voids, backlint, and poor appearance from occurring.

In addition to this, due to the pressure difference caused by the reduced pressure in the degassing section 6 and the curvature R of the molding groove 2A, the pressure in the molding groove 2A toward both ends of the mold 10 due to fluidization of the molding material M is increased. The partial pressure is reduced, the displacement of the molding material M due to the pressurized flow in the axial direction of the molding groove 2A is kept low, and the excess molding material M overflows into the degassing section 6 and the escape groove 3A, compared to the conventional method. Large O-rings with high dimensional accuracy can be joint-molded with excellent quality.

In this example, the depressurizing and degassing means A was provided only in the single mold 10A, but it may be provided in the upper mold 10B or both, and the molding groove 2A was provided with a curvature R. It is not limited to this, and it may be linear,
Molding grooves 2 generated toward both ends of the mold 10 during crosslinking molding
It may be set to an appropriate shape that reduces the component force in the axial direction of A. Furthermore, the shape and size of the deaeration section 6 and the shape of the partition wall W are not limited to this embodiment, and the shape of the molded material M is not limited to the zero cross section, but the cross-sectional shape and size of the molded material M. During the joint forming, the joint forming part 2a
The thickness of the partition wall W can maintain the pressure necessary for degassing under reduced pressure and crosslinking of the molded material M, and the shape of the degassing section 6 is sufficient to perform the necessary degassing.

The dimensions may be set appropriately.

Furthermore, the seal members S on the three side peripheries of the deaeration section 6 are not limited to the 0-shaped cross section, but seal members having an appropriate cross-sectional shape with an appropriate crushing allowance may be installed in appropriate mounting grooves. Just set it like this.

In addition, although this example describes the case where a cross-linked molded material that is preformed by being divided into a plurality of pieces is formed, the present invention is not limited to this, and an endless molded product having a large cross-sectional area is formed. When integrally molded in a large mold, a vacuum degassing means is installed adjacent to the joint of the molding groove of the mold where the ends of the extruded molding base material are loaded so that they overlap or are not stepped. If this is done, the quality of the molded product can be significantly improved, and the bonding process before crosslinking can be omitted, increasing production by +1.

〔Effect of the invention〕

As explained above, according to the present invention, a vacuum degassing means for depressurizing and deaerating the link molding part is provided adjacent to the link molding part of the molding groove of the compression molding mold used for link molding, By configuring the joint molding part to be deaerated at a reduced rate, it is possible to prevent voids and huck lint that occur in the joint molding part of the molded product during joint molding, and to prevent appearance defects due to residual air. This effectively suppresses the axial displacement of the molding groove that occurs due to the fluidization of the crosslinked molded material, and reduces the variation in dimensions of the joint molded product, resulting in large crosslinking with excellent quality and dimensional accuracy. Molded products can be obtained at low prices.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of a compression molding die showing an embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view of the same <B-B section, and Fig. 3 is an exploded perspective view of a compression molding die showing an example of a conventional example. FIG. 4 is an exploded perspective view of the mold. FIG. 4 is a sectional view showing a state in which the section CC in FIG. 3 is loaded into the mold. 1.10 is compression molding mold, IA, IOA are f type, IB
, IOB is 1D type, 2 and 2A are molding grooves, 2a is a connecting molding part, 3 and 3A are relief grooves, 6 is a vacuum degassing part, 7 and 8 are vacuum degassing holes, 9 is a vacuum degassing pipe, A is a vacuum degassing means, M
is a crosslinked molded material. In addition, in the figures, the same or corresponding parts are represented by the same reference numerals.

Claims (1)

[Claims] This is a compression molding mold for joining and molding mutual ends of a cross-linked molded material, and the mold is divided into upper and lower molding grooves. A compression molding mold characterized by being provided with a degassing means.