JPH0222257Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a mold base used when molding is performed by injecting and filling a molten material such as plastic, glass, rubber, or die-casting into a mold.
In particular, the present invention relates to a guide device that performs positioning between a stationary template and a movable template.

For example, when molding plastics, etc., a mold base that incorporates auxiliary means such as a resin distribution structure and a molded product ejection mechanism in addition to the cavity (female mold) and core (male mold) to form an integrated mold set is used. used. This mold base consists of a main mold set consisting of movable side and fixed side templates on which the cavity core is formed, a receiving plate as an auxiliary plate, and a receiving plate as an auxiliary plate.
It is an assembly of a movable side mounting plate, a fixed side mounting plate, a spacer block, an ejector plate, etc., and is constructed as shown in FIGS. 1a and 1b, for example.

FIG. 1a is an exploded perspective view showing the general structure of a mold base, which is of a general structure, and FIG. 1b is a sectional view of the main part thereof. Here 1
and 2 are a fixed side mounting plate and a movable side mounting plate for attaching the mold base to the platen of a molding machine, and 3 and 4 are a fixed side mold plate and a movable side mold plate into which the cavity and core are engraved or fitted, respectively. Further, 5 is the movable side template 4
This is a receiving plate that receives the resin pressure applied to the resin. and,
A pair of spacer blocks 6 are sandwiched between the receiving plate 5 and the movable side mounting plate 2, thereby ensuring a movable space for the ejector plate (not shown).
Further, as a guide device for aligning the movable side template 4 and the fixed side template 3, a guide bush 9 is press-fitted and fixed to the movable side template 4, and a guide pin 10 is press-fitted and fixed to the fixed side template 3. The mounting plates 1 and 3 on the fixed side and the mold plates 2 and 4, the receiving plate 5, and the spacer block 6 on the movable side are fixed by bolts 11, respectively. 12 is a molded product made of the cavity and core.

The gap between the guide bush 9 and the guide pin 10, that is, the clearance is usually measured in diameter.
It is said to be around 20μm, and the smaller this clearance, the better the mold matching accuracy.
If the clearance is made small, problems such as difficulty in attaching and detaching the templates 3 and 4 to each other and a tendency for galling and seizing to occur will occur.

In other words, the movable template 4 and the fixed template 3 are as follows:
Until the mold is completed or when repairing the cavity core, attachment and detachment are repeated frequently, but if you do not move the template plates parallel to each other, the guide pin 1
0 and guide bush 9 become twisted and difficult to move. This tendency is exacerbated as the clearance between the guide pin and the guide bush becomes smaller, and there is a problem in that the burden on the operator increases each time.

Or guide pin 1 implanted in templates 3 and 4
0. Galling and seizure are likely to occur due to manufacturing pitch errors in the position of the guide bushing 9, irregular movement accuracy of the movable platen of the molding machine, poor maintenance of the guide pin 10 and guide bushing 9, etc., but this is due to the guide device. The smaller the clearance, the more severe it becomes. However, if the clearance between the guide pin 10 and the guide bush 9 is large, even if the cavity core is formed at the correct position on the templates 3 and 4, the mold will be misaligned by the clearance, resulting in a highly accurate molded product. I can't.

Furthermore, the high pressure during resin injection may cause uneven thickness when the side surface projected areas S ₁ and S ₂ of the molded product 12 are asymmetrical, as shown in FIG. 2a. In other words, the mold plates 3 and 4 receive a lateral shearing force which is the product of the side surface projected area difference S ₁ −S ₂ of the molded product 12 and the mold internal pressure, so they move within the clearance of the guide device, and the side surface projected area is reduced. The larger one has a larger wall thickness, and the smaller one has a smaller wall thickness. Therefore, in order to eliminate the above-mentioned drawbacks, conventionally, the clearance of the guide device has been increased by forming a spigot part F as shown in FIG. 2b or by embedding taper locators 13 and 14 as shown in FIG. I was trying to get rid of it. However, forming such a pilot part F or taper locators 13, 14 reduces the effective area of the mold plates 3, 4, and also reduces the parting of the mold with the clearance completely eliminated. The lines had to match exactly, so achieving both required precision work and a lot of effort, which was a problem.

Therefore, we focused on the fact that the positional relationship of the guide device was already precisely machined, and formed a tapered part on a part of the guide pin that becomes narrower from the base side to the distal side, and a part of the guide hole. Some attempts have been made to solve the above-mentioned problems by forming a tapered hole portion in contact with the tapered portion.

With this taper pin method, if the taper on the guide pin side and the taper on the bushing side can be perfectly matched, it will be effective in improving and maintaining mold matching accuracy, but in reality, the taper angle of both It is quite difficult to achieve this completely, and the taper of the guide pin and the taper of the bush tend to contact only partially, and the above-mentioned lateral load is generated between the templates 3 and 4. If this occurs, the guide pin or bush may become partially deformed, making it impossible to maintain machining accuracy.
There is a problem.

The present invention was developed in view of the above-mentioned circumstances, and utilizes the advantages of the taper pin method described above, and is also easy to process and creates a mold base that reduces deformation at the contact surface between the guide pin and the bushing. The object of the present invention is to provide a guide device.

Hereinafter, an embodiment of a mold base guide device according to the present invention will be described with reference to the drawings.

FIGS. 3a and 3b are cross-sectional views showing essential parts of an embodiment of the guide device according to the present invention, and parts having the same functions as those of the conventional device shown in FIG. 1 are given the same reference numerals. It is shown. In this embodiment, the fixed side template 3
A guide pin 110 is implanted in the guide pin 110, and the guide pin 110 has a large diameter embedded base 110a and a small diameter guide part 110b.
A curved tapered portion 15 is formed at the boundary between the guide portion 10a and the guide portion 110b, and is tapered toward the distal end and has at least a portion formed into a curved surface.
16 is a retaining flange formed at the other end of the embedded base 110a, and 17 is an oil groove formed in the guide portion 110b. Thus, the embedded base 110a is fitted into the embedded hole 3a formed in the stationary template 3, and the guide portion 110b including the curved tapered portion 15 is fixed and held in a state protruding from the lower surface of the template 3. has been done.

On the other hand, a guide bush 109 is press-fitted into the embedded hole 4a of the movable template 4, and the inner hole of the guide bush 109 is connected to the guide pin 11.
0 is a guide hole 18 into which the guide hole 18 is slidably inserted. The opening 18a of the guide hole 18 has a tapered hole portion 19 that comes into contact with the curved tapered portion 15 of the guide pin 110 when the mold is closed.
A retaining flange 20 is formed on the outer periphery of the other end of the guide bush 109 where the tapered hole 19 is formed.

In this case, the relationship between the curved taper portion 15 and the tapered hole portion 19 is such that the maximum diameter of the portion forming the curved surface of the curved taper portion 15 is
It is preferable to form a curved surface so that the curved taper portion 15 comes into contact with the tapered hole portion 19 at approximately the center thereof.

In this manner, in the guide device of the present invention, the guide pin 110 and guide bush 109 are aligned using the curved tapered portion 15 and the tapered hole portion 19, so there is no need for alignment of the tapered surfaces.

That is, since the curved taper part 15 can be formed to have a predetermined diameter in the tapered hole part 19 whose inner circumferential surface has been machined into a tapered shape, the machining of both parts becomes extremely easy. Further, it is preferable that the taper angle of the tapered hole portion 19 is set within a range of 10° to 15° with respect to the vertical on each side.

Next, a method for attaching the above-mentioned guide device to each template 3, 4 will be described. In this case, first, the length from the upper end of the guide pin 110 to the lower end of the guide bush 109 when the curved tapered part 15 and the tapered hole part 19 are in contact with each other is longer than the thickness T of the main mold shown in FIG. 3b. The guide pins 110 and guide bushes 109 are attached to each template 3 and 4 so that they are slightly larger. At this time, guide pin 1
Since the combined length of the guide pin 10 and the guide bush 109 is larger than the thickness T of the main mold, when this is placed on a flat surface, the flange 1 of the guide pin 110
b or flange 20 of guide bush 109
The side end portion of
It will become more prominent. If this protruding portion is polished off, the combined length of the guide pin 110 and guide bush 109 will match the thickness T of the main mold. By adjusting this length, a gap t is created between the flange 20 and the buried portion 4a, as shown in FIG. 3b, for example.
Since the guide bush 109 exists in the direction opposite to the direction of the force that the guide bush 109 receives when the space between the two ends is closed, there is no problem in operation.

When the mold is closed, as shown in an enlarged view in FIG. The clearance between the portion 110b and the guide hole 18 can be relatively large, and the positioning work can be performed with high precision.

Therefore, the templates 3 and 4 can be easily attached and detached, and there is less risk of galling or seizure.

Furthermore, the guide pin 110 and the guide bush 1
09 is received by the curved surface, there is less risk of damage to the abutting surfaces of the two. In addition, it is possible that an extremely large lateral shearing force may occur between the templates 3 and 4, which may cause some deformation at the contact surface between the curved tapered portion 15 and the tapered hole portion 19. Since the deformation acts to rapidly increase the contact area between the two, it becomes possible to sufficiently resist the lateral shear force. Therefore, since a large load is not locally applied to the abutting portion of the two, which has a particularly small area, deformation of the abutting surface between the curved tapered portion 15 and the tapered hole portion 19 is extremely small.
This means that high alignment accuracy can be maintained.

By the way, in the embodiment described above, the guide post 1
Although an example in which a curved taper portion is formed on the 10 side is shown, a curved taper portion may be formed on the guide bush 109 side.

That is, as shown in FIG.
By forming a tapered part 15a between the embedded base part 110a of No. 10 and the guide part 110b, and forming the tapered hole part 19a near the upper end of the guide bushing 109 into a curved tapered shape as shown in the figure, the two are brought into contact with each other. It is also possible to perform alignment.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with various modifications without changing the gist thereof.

As explained above, according to the guide device of the present invention, a tapered portion that becomes thinner from the base side toward the distal end side is formed in a part of the guide pin, and
A tapered hole is also formed in a part of the guide hole, a part of either of the two tapers is formed into a curved surface, and positioning is performed by bringing this curved surface into contact with the other taper. It is something.

Therefore, it has the feature of being able to perform high-precision mold matching without reducing the clearance of the guide device, and as a result, even if the templates are repeatedly attached and detached, there is no risk of seizure or galling in the guide device. There is no risk of this occurring. Furthermore, since there is no need to use other members such as locators, there is no risk of reducing the effective area of the template. Furthermore, the processing of the guide device becomes extremely easy, and the only high-precision positioning work required during mold assembly is the work of attaching the guide device, resulting in extremely large effects such as a significant improvement in work efficiency.

In addition, in the guide device of the present invention, the load applied between the guide post and the guide bush can be received by the curved surface, so there is less deformation at the contact area between the two, which is excellent in terms of maintaining mold matching accuracy. That's what you get.

[Brief explanation of the drawing]

FIGS. 1a and 1b are an exploded perspective view and a sectional view for explaining the schematic structure of a conventional mold base,
Figures 2a and b are explanatory cross-sectional views for explaining the problems of conventional molds, and Figures 3a and b are cross-sectional views of essential parts showing an embodiment of the mold base guide device according to the present invention. FIG. 4 is an enlarged sectional view of the main part of the same embodiment, and FIG. 5 is a sectional view of the main part showing another embodiment of the guide device according to the invention. 3... Fixed side template, 4... Movable side template, 110... Guide pin, 18... Guide hole, 15... Curved tapered part, 19... Tapered hole part.

Claims (1)

[Scope of utility model registration request] A guide device comprising a guide pin and a guide bush for guiding and positioning between each template of a main mold set consisting of a fixed template and a movable template in which a cavity core is formed, the guide pin and A tapered part is provided in a part of the guide hole of the guide bushing, and one part of the tapered part is formed into a curved shape, and this curved part comes into contact with the other tapered part. A guide device for a mold base, characterized in that it has a configuration in which templates are aligned.