JP2001300950A - Vacuum casting silicon mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum casting silicon mold having effectively extended life and capable of coping with multikind production. SOLUTION: The vacuum casting silicon mold 10 consists of a pair of splittable molds 11, 12 joined by joining parts 13. A molding material is injected in a cavity 14 to be subjected to insert molding. A screw part setting part 20 threaded with a screw part to be subjected to insert molding is provided to the predetermined region of the cavity 14 in a detachable manner. This screw part setting part 20 includes the fixing collar 23 fitted in the mounting hole 16 provided to the predetermined region of the cavity 14, the female screw collar 24 fitted in the fixing collar 23 in a detachable manner and male screw parts 21, 22 threaded with the female screw collar 24. The screw sizes of the female screw collar 24 and the male screw parts are variable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded product used in various industrial products, and more particularly to a silicon mold for vacuum casting suitable for molding an insert molded product.

[0002]

2. Description of the Related Art FIG. 10 shows an example of a conventional silicon mold for vacuum casting. In the silicon mold 100, a pair of molds 101 and 102 that can be split are joined at a joining portion 103, and a cavity 104 (see FIG. 12) is formed inside. A molding material is injected into the cavity 104 from a material injection port 105.

[0003] In this type of silicon mold, particularly in the molding of an insert molded product, an example of manufacturing an insert molded product W as shown in FIG. The molded article W may be a resin part or the like used for a passenger car or the like, and a screw part (such as a screw or a bolt) 106
Is inserted. First, as shown in FIG. 11 (B), a mold is formed using the molded product W as a model (ie, a silicon flow). Thus, a silicon mold 100 'is formed.

Next, the silicon mold 100 'is divided as shown in FIG. Thereby, a pair of molding dies 101,
102 is obtained. A cavity 104 is formed on the opposing surfaces of the pair of molding dies 101 and 102 as shown in the figure, and a portion divided into two forms a joining portion 103. The mold is divided in this manner, and a molded product W as a model is taken out.
After the molded product W is taken out, the screw or bolt 106 to be inserted is inserted into the screw hole 107 of one molding die 102 formed by this molding (see FIG. 13). Then, the silicon mold 100 as shown in FIG. 10 is obtained as described above by matching the pair of molds 101 and 102 again.

[0005]

However, in the conventional silicon mold 100, the screw hole 107 is particularly deteriorated (sagged) during repeated casting many times. In some cases, resin (molding material) was covered on the screw portion. For this reason, in order to maintain the quality of the molded product W as a product, the silicon mold 100 has to be remade many times. In the conventional silicon mold 100, the number of screws or bolts 106 to be inserted is limited to one type (especially, screw size).

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a vacuum casting silicon mold capable of effectively extending the mold life and responding to multi-product production.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method in which a pair of split molds are joined at a joint, and a molding material is injected into a cavity to perform insert molding. A silicon mold for vacuum casting, characterized in that it has a screw component set portion in which a screw component to be insert-molded is detachably attached to a predetermined portion of the cavity.

In the silicon mold for vacuum casting according to the present invention, preferably, the screw part set portion is fixedly fitted in a mounting hole provided in a predetermined portion of the cavity, and is detachably fitted in the fixed collar. And a male screw part screwed into the female screw collar.
In the silicon mold for vacuum casting according to the present invention, it is preferable that the screw sizes of the female screw collar and the male screw part are variable.

In the silicon mold for vacuum casting according to the present invention, preferably, the externally threaded component has a head portion or a base portion inserted into a molded product. It is preferable that the male screw part is screwed detachably from the molded product.

According to the present invention, the predetermined portion of the cavity is provided with the screw component set portion formed by screwing the screw component to be insert-molded. This screw component set portion is configured to be detachable via a fixed collar as a separate object from the mold. Therefore, when a thread portion such as a female thread collar is deteriorated, only the portion can be easily replaced, and as a result, the life of the mold can be effectively extended.
Further, by using a screw component set portion corresponding to the size of the screw or bolt to be inserted, it is possible to effectively cope with a change in the screw size.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a silicon mold for vacuum casting according to the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a silicon mold for vacuum casting in this embodiment. The silicon mold 10 is formed by joining a pair of molds that can be split, that is, an upper mold 11 and a lower mold 12 to the joint 1.
3 and a cavity 14 is formed inside as shown. A molding material is injected into the cavity 14 from a gate 15.

FIG. 2 shows an example of an insert molded product W to which the present invention is applied. 2A shows the front side, and FIG. 2B shows the back side. The molded product W may be a resin component or the like used for a passenger car or the like, and a screw component (a screw, a bolt, or the like) is inserted into a predetermined portion (A 'portion or the like).

The silicon mold 10 has a screw part setting part formed by screwing a screw part to be insert-molded so as to be detachably attached to a predetermined part of the cavity 14 (A part corresponding to the A 'part of the molded product W). 20. In this embodiment, a screw 22 having a straight bolt 21 as shown in FIG. 3 and a head or base 22a inserted into a molded product W as shown in FIG. Is used selectively. Bolt 2
1 is used when forming a concave screw W1 in the molded product W as shown in FIG. 8, and the screw 22 is used when being inserted into the molded product W as shown in FIG.

In the silicon mold 10 for vacuum casting, the screw component setting section 20 includes a fixing collar 23 which fits into a mounting hole 16 provided in a predetermined portion of the cavity 14 as shown in FIG. And a female screw collar (bolt 21 or screw 22) screwed into the female screw collar 24 so as to be removably fitted inside.

Next, a method of forming the screw component setting section 20 and the like will be described. 6 and 7 show main steps for forming the screw component setting section 20 in order.
The fixed collar 23 is formed in a predetermined shape and size by machining with a lathe or the like in advance. That is, as shown in FIG. 5, the fixing collar 23 is typically made of metal, and has an inner hole 23a into which the female screw collar 24 is inserted and a retaining projection 23b formed to protrude from the outer peripheral surface. are doing.

FIG. 6 shows mainly the main steps for forming the female screw collar 24 in order. In FIG. 6A, the fixing collar 23 is placed on the resin plate 1 and the screw 2 is inserted from below. In addition, this screw 2
The screw size is the same as that of the insert-molded screw component (bolt 21 or screw 22). Next, in FIG. 6B, each part is set and fixed using an adhesive 3 or the like.
Subsequently, as shown in FIG. 6C, a silicon material m is injected into the inner hole 23a of the fixed collar 23. And FIG.
As shown in (D), the adhesive 3 of each part is removed, and the female screw collar 24 is taken out from the fixed collar 23. A female screw portion 24a is formed by the screw 2 inside the female screw collar 24 thus formed.

FIG. 7 shows mainly the main steps for forming the bolt 21 in order. In this case, the bolt 21
It is assumed that the female screw collar 24 already formed is used as a molding die for. First, in FIG. 7A, a female screw collar 2 is placed on a resin plate 4 on which a double-sided tape 5 is stuck.
4 and insert the screw 6 from below. next,
In FIG. 7B, each part is set and fixed. Subsequently, as shown in FIG. 7C, the silicon material m is injected into the female screw portion 24a of the female screw collar 24. Then, as shown in FIG. 7D, the silicon bolt 21 is taken out from the female screw collar 24.

In the above-described configuration, for example, when a molded product W having a concave screw W1 at a predetermined position is formed, a bolt 21 is fixed to the screw component setting section 20 via a fixing collar 23 and a female screw collar 24 as shown in FIG. Is set. Then, the upper mold 11 and the lower mold 12 are aligned so as not to be displaced, and a molding material is injected from the gate 15. After the injected molding material is solidified, the mold is opened and a molded product W as shown in FIG. 2 is taken out from the inside. At this time, by removing the bolt 21 from the molded product W, a concave screw W1 is formed in the molded product W as shown in FIG. A screw W2 may be screwed onto the concave screw W1 at the product stage.

When molding a molded product W into which the screw 22 is inserted at a predetermined position, the screw component setting section 20
Next, as shown in FIG.
Then, the screw 22 is set via 4. Similarly, after the injected molding material is solidified, the mold is opened and a molded product W as shown in FIG. 2 is taken out from the inside. In this case, the screw 22 is inserted into the molded product W as shown in FIG. This screw 22
Then, the nut W3 may be screwed at the product stage.

As described above, the screw component setting section 20 is configured to be detachable via the fixing collar 23 as a separate object from the mold. Then, by screwing the bolt 21 or the screw 22 to the screw component setting portion 20, the molded product W having the concave screw W1 or the molded product W into which the screw 22 is inserted can be selectively molded. Thus, a plurality of types of molded articles W of different types can be obtained.

In these cases, when the thread portion of the female screw collar 24 or the like is deteriorated, only the portion can be easily replaced, and as a result, the life of the mold can be substantially extended. That is, by removing the female screw collar 24 from the fixed collar 23 and replacing it with a new one, it is possible to always perform an appropriate molding process and to guarantee the quality of the product without recreating the entire silicon mold 10.

The size of the bolt 21 or the screw 22 set in the screw component setting section 20 can be changed as required. It is possible to cope with various screw sizes simply by replacing the female screw collar 24.

The arrangement and number of the screw component setting sections 20 in the above embodiment can be changed as necessary.

[0024]

As described above, according to the present invention, in this type of vacuum casting, the life of the mold can be effectively extended, and it is possible to cope with multi-product production. In this case, there are advantages that the quality of the product is maintained and that it is possible to immediately respond to a change in the type of the product.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a silicon mold for vacuum casting in an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an insert molded product according to the embodiment of the present invention.

3A and 3B are a perspective view and a cross-sectional view illustrating an example of a screw component setting section according to the embodiment of the present invention.

FIG. 4 is a perspective view and a cross-sectional view showing another example of the screw component setting section in the embodiment of the present invention.

5A and 5B are a perspective view and a cross-sectional view illustrating a configuration example of a screw component setting section according to the embodiment of the present invention.

FIG. 6 is a view sequentially showing main processes for forming a screw component set portion in the embodiment of the present invention.

FIG. 7 is a view sequentially showing main steps for forming a screw component set portion in the embodiment of the present invention.

FIG. 8 is a perspective view showing an example of a molded product according to the embodiment of the present invention.

FIG. 9 is a perspective view showing another example of a molded product according to the embodiment of the present invention.

FIG. 10 is a perspective view showing an example of a conventional silicon mold for vacuum casting.

FIG. 11 is a view showing a mold making process in a conventional silicon mold for vacuum casting.

FIG. 12 is a view showing a mold making process in a conventional silicon mold for vacuum casting.

FIG. 13 is a view showing a mold making process in a conventional silicon mold for vacuum casting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin plate 2 Screw 3 Adhesive 4 Resin plate 5 Double-sided tape 6 Screw 10 Silicon mold 11 Upper mold 12 Lower mold 13 Joining part 14 Cavity 15 Gate 16 Mounting hole 20 Screw part set part 21 Bolt 22 Screw 23 Fixed collar 23a Inner hole 23b Retaining projection 24 Female thread collar 24a Female thread W Molded product W1 Concave screw

Claims (5)

[Claims] 1. A vacuum casting silicon mold in which a pair of molds that can be split are joined at a joining portion, and a molding material is injected into a cavity to perform insert molding. A silicon mold for vacuum casting, comprising: a screw component set portion in which a screw component to be insert-molded is detachably attached to the screw component. 2. The screw component set portion includes: a fixed collar that fits into a mounting hole provided in a predetermined portion of the cavity; a female screw collar that is removably internally fitted to the fixed collar; The silicone mold for vacuum casting according to claim 1, further comprising a male screw part to be combined. 3. The silicon mold for vacuum casting according to claim 2, wherein the screw sizes of the female screw collar and the male screw component are variable. 4. The silicon mold for vacuum casting according to claim 2, wherein said male screw component has a head portion or a base portion inserted into a molded product. 5. The silicon mold for vacuum casting according to claim 2, wherein the male screw part is detachably screwed from a molded product.