JPS6325137Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a molded product ejection mechanism in a mold for compression molding a thermosetting resin.

In the compression molding method for thermosetting resins, a molding material is put into a heated mold cavity and pressurized by a press, thereby melting and hardening the material and molding the product. After molding, the upper and lower molds are opened and the ejector mechanism releases the molded product.

To illustrate and explain the conventional ejection mechanism, Fig. 1 is a plan view of the lower die of the mold, Fig. 2 is a vertical sectional view taken along the - arrow in Fig. 1, with the upper die indicated by a broken line, and Fig. 3. is an exploded perspective view of the upper plate of the protrusion plate and part of the protrusion pin, viewed from below. 1 and 2, 10 is a lower mold mounting plate, 12 is a spacer block, 14 is a lower mold mother mold, 16 is a lower mold insert, 18
is Cavitei, 20 is Cavity Bushiyu, 22
2 is an upper mold mother mold, and 24 is an upper mold mounting plate. The lower mold insert 16 is provided with heating means, such as a steam passage 26, for heating the lower mold insert to the molding temperature. The lower mold insert 16 is fitted into the recess of the lower mold matrix 14. The dimensions of the lower mold insert 16 are determined by the reference surface of the mother mold as shown in the figure during cooling.
Although it only contacts AA and BB, it is designed so that when heated to the molding temperature, it will thermally expand and come into contact with surfaces CC and DD as well.

As shown in FIG. 2, a protruding plate consisting of an upper plate 28 and a lower plate 30 fixed to each other is arranged in the space defined by the lower die mounting plate 10, the spacer block 12, and the lower die matrix 14. has been done. A guide pin bush 3 is connected to a translation mechanism (not shown) such as this projecting plate and a double-acting piston cylinder, and is slidably fitted to the guide pin 32.
4, and can move up and down while being guided by a guide pin 32. For example, three protruding pins 36 are attached to the protruding plate.
A boss portion 38 is integrally formed at the lower end of each protruding pin 36. As can be seen from FIGS. 2 and 3, a through hole 40 consisting of a stepped bore is provided in the upper plate 28 of the ejector plate in correspondence with each ejector pin, and the ejector pin 36 is inserted into the through hole 40. After inserting the upper plate 28 and the lower plate 30 from below, the upper plate 28 and the lower plate 30 are fixed to each other by bolting or the like, so that the lower end of the ejecting pin, that is, the boss portion, is moored to the ejecting plate.
At this time, the boss portion 38 has a horizontal shoulder portion 46 between the small diameter bore 42 and the large diameter bore 44 of the through hole 40;
It is held between the upper surface of the lower plate 30 and the upper surface of the lower plate 30.

The upper part of the ejecting pin 36 is aligned on the same axis as the through hole 40 and inserted into through holes 48 and 50 formed in the lower mold matrix 14 and the lower mold insert 16.
The upper end of the through hole 50 has a reduced diameter, and the upper end of the protruding pin 36 is slidably and precisely fitted into this part. Therefore, when the protruding plate moves up and down,
The ejecting pin 36 moves in and out of the lower mold insert 16 while being guided near the upper end by the reduced diameter portion of the through hole 50 to eject the molded product within the cavity 18 . Ejecting pin 36
The upper end surface is aligned with the surface of the lower mold insert and defines a portion of the lower surface of the molded article. Therefore, it is undesirable for this ejector pin to rotate about its axis. Therefore, as shown in FIGS. 2 and 3, a detent pin 52 is driven into the boss portion 38 of the ejecting pin 36 in the radial direction, and the free end of the detent pin 52 is connected to the large diameter bore of the through hole 40. Rotation of the ejector pin 36 is prevented by engaging it in a notch 54 provided in the ejector plate upper plate 28 adjacent to the ejector pin 44 . In this conventional anti-rotation structure, no particular consideration is given to the direction of the anti-rotation pins 52, and each anti-rotation pin is arranged, for example, in the direction indicated by the arrow in FIG.

However, in the conventional ejecting mechanism described above, the vicinity of the upper end of the ejecting pin 36 is guided by the reduced diameter portion of the through hole 50 of the lower mold insert 16, so that when the lower mold insert 16 is heated, its thermal expansion occurs. According to plane CC and plane
Although it is displaced toward DD (FIG. 1), its lower end, that is, the boss portion 38, is moored to a protruding plate that is less affected by heat, so the displacement is small. As a result, the upper and lower ends of the ejector pin became eccentric, causing deformation of the ejector pin and causing sliding failure when ejecting the molded product.

The present invention was devised in view of the above-mentioned problems of the prior art, and it is an object of the present invention to provide an ejection mechanism that can avoid sliding defects of the ejection pin.

Therefore, in the ejection mechanism of the above-described structure, the lower end of the ejection pin is attached to the ejection plate so as to be movable along a plane parallel to the ejection plate, and the detent pin is used for heating and cooling the mold. It is characterized in that the upper end of the protruding pin is oriented in the direction in which it is displaced as the lower die insert thermally expands and contracts. With this configuration, it is possible to slide the lower end of the ejector pin within the ejector plate following the expansion and contraction of the lower mold insert, and to always align the axis of the lower end with the axis of the upper end.

Next, embodiments of the present invention will be described with reference to the drawings from FIG. 4 onwards. Components common to those shown in FIGS. The detailed explanation will be omitted.

4 is a plan view similar to FIG. 1, FIG. 5 is a vertical sectional view taken along the - arrow in FIG. 4, and FIG. 6 is an enlarged view of the portion inside the broken line circle in FIG. As shown in FIG.
A through hole 40' having a larger size than the hole 40' is provided, and an annular slide plate 56 is interposed between the boss portion 38 and a shoulder portion 46' of the through hole 40'. The distance between the outer circumferential surface of the slide plate 56 and the inner circumferential surface of the large diameter bore 44' is set to be larger than the maximum displacement of the lower mold insert 16 due to thermal expansion. Further, the distance between the shoulder portion 46' and the lower plate 30 is the same as that between the boss portion 38 and the slide plate 56.
Shoulder portion 46'
The boss portion 38 and the slide plate 56 are allowed to slide laterally between the lower plate 30 and the lower plate 30.

Although the detent pin 52' is driven into the slide plate 56 in this embodiment, it may be fixed to the boss portion 38 as in the conventional example. Each detent pin 5
The free end of 2' is engaged in a notch 54' in the top plate 28. Each notch 54' is oriented in the direction in which the upper end of the ejector pin 36 is displaced as the lower die insert 16 thermally expands, as indicated by the arrow in FIG. They therefore extend in the same direction as the corresponding cutouts for the detent pins housed within them. The angle θ of each notch 54' with respect to the reference plane BB of the lower mold matrix 14 is equal to the angle that a line connecting the intersection O of the reference planes AA and BB and each ejecting pin makes with the reference plane BB.

When the lower mold insert is heated during molding, the lower mold insert thermally expands around point O in FIG. 4, and the upper end of each ejector pin is displaced in the direction of the arrow in FIG. 4. Therefore, a lateral biasing force acts on the lower end of the protruding pin in the direction of displacement of the upper end, and the sliding plate 56
Then, slide the boss portion 38 to align the upper and lower ends of the ejector pins. Each detent pin 52' is oriented in the direction of displacement of the upper end of the ejector pin, so that said sliding movement is not impeded.

As is clear from the above, in the present invention, the lower end of the ejector pin is movably mounted along a plane parallel to the ejector plate, and the detent pin is oriented in the direction of displacement of the upper end of the ejector pin due to heating and cooling of the mold. Since this is determined, the lower end can be displaced following the displacement of the upper end of the ejector pin, and the axes of the upper and lower ends of the ejector pin can always be aligned. Therefore, the ejector pin can be smoothly operated when the mold is heated.

[Brief description of the drawings]

Fig. 1 is a plan view of a lower mold with a conventional ejection mechanism, Fig. 2 is a vertical sectional view taken in the direction of - arrow in Fig. 1, and Fig. 3 is a view of a part of the ejection plate and ejection pin from below. FIG. 4 is a plan view of the lower die equipped with the ejection mechanism of the present invention, FIG. It is an enlarged view of a part. 10...Lower die mounting plate, 12...Spacer block, 14...Lower die matrix, 16...Lower die insert, 1
8... Cavity, 20... Cavity butsuyu,
22...Upper mold mother mold, 24...Upper mold mounting plate, 26
... Heating means, 28, 30 ... Projection plate, 28...
... Upper plate of the protruding plate, 30... Lower plate of the protruding plate, 3
2...Guide pin, 34...Guide pin bushing,
36...Ejection pin, 38...Boss part, 40,4
0'...Through hole, 42, 42'...Small diameter bore, 44,
44'...Large diameter bore, 46, 46'...Shoulder, 4
8, 50... Through hole, 52, 52'... Rotating pin, 54, 54'... Notch, 56... Slide plate.

Claims (1)

[Scope of utility model registration request] a protruding plate that is movable up and down within a space defined by a lower mold matrix carrying a lower mold insert, a lower mold mounting plate, and a spacer block held between the two;
Includes an ejector pin whose lower end is attached to the ejector plate and whose upper end vicinity is slidably supported by the lower mold insert, and a detent pin for preventing relative rotation of the ejector pin with respect to the ejector plate. In the ejection mechanism for a compression molding mold, the lower end of the ejection pin is attached to the ejection plate so as to be movable along a plane parallel to the ejection plate, and the detent pin is attached to the ejection plate during heating and cooling of the mold. An ejecting mechanism for a compression molding mold, characterized in that the ejecting pin is oriented in a direction in which the upper end of the ejecting pin is displaced as the lower mold insert thermally expands and contracts.