JPH0244971Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to molds, and more specifically, aims to improve the dimensional stability of molded products and reduce manufacturing costs in molds using low-viscosity resin materials such as liquid silicone rubber as the molding material. The aim is to give what you get.

Conventionally, this type of mold is known to be made by injection molding using a press machine or by casting, but although the former method of molding using an injection molding machine has excellent quality stability of the molded product (product), In addition to expensive press equipment, the cycle of use of the press equipment depends on the curing time of the resin material, resulting in low productivity and increased processing costs. In the case of the latter casting method, only a resin injection device is required and, although it has an excellent economical advantage, it has the disadvantage that the quality stability of the molded article (product) is poor.

In view of the above points, the present invention has developed a first tube having a substantially cylindrical shape.
It has a mold, and a substantially lid-shaped second mold and a third mold that are detachably attached to both open ends of the through hole of the first mold, and the second mold and the third mold have tightening guides that are close to each other and face each other. A mold clamping mechanism using spring means for firmly clamping each of these molds is provided at the proximal end of both clamping guides, thereby satisfying both quality stability of molded products and economical efficiency. The purpose is to provide molds.

Hereinafter, one embodiment of the mold of the present invention will be explained with reference to the drawings.The mold has a low viscosity material such as liquid silicone rubber on the outer peripheral surface of the insert b which is inserted and fixed onto the core rod shown in the figure a. The resin material c is molded and fixed to obtain a molded product consisting of the core rod a, the insert b, and the resin material c. To explain the structure in detail, 1 has a substantially cylindrical shape and has an injection port 2 for molding material at one end in the axial direction.
A second mold 4 and a third mold, each of which has a substantially lid-like shape at both open ends 3a and 3b of the internal through hole 3 of the first mold 1.
The mold 5 is removably fitted. The second mold 4 and the third mold 5 also have through holes 6 and 7 in their axes to allow the core rod a to pass therethrough for positioning. O-rings 8 and 9 are interposed between the end and the insert b to prevent the molding material from flowing out to the outside before solidification. One end of each of the two tightening guides 10, 10 is fixed to a 180 degree symmetrical position on the outer peripheral surface of the second mold 4 with a hexagon socket head bolt 11 and a parallel pin 12, and similarly fixed to the third mold 5. 2 pairs (1
A mold clamping mechanism 14 (only a pair shown) is constructed.
The mold clamping mechanism 14 has a locking end 15 formed protruding outward (upward in the figure) at the proximal end of the second mold 4.
and an actuating part 16 provided on the third mold 5 side, and the actuating part 16 includes a lever 17 pivotally attached to the proximal end of the third mold 5 side, and a lever 17 near the base of the lever 17. A spring holder 19 is pivotally attached to the spring holder 19 with a pin 18, and a substantially T-shaped holder pin 20 is slidably inserted into a hooked end 19a formed at the tip of the spring holder 19. , the hooked end 19a and the holder pin 20
A coil spring 21 and a spacer 22 are inserted between the T-shaped ends. 23 is the holder pin 20
Nut 24 screwed onto the other end is a washer.

The mold having the above configuration incorporates the core rod a and the insert b which is inserted and fixed to the core rod a into the mold, and inserts the second
After the mold is clamped by the mold clamping mechanism 14 connected to the mold 4 and the third mold 5, the molding material is poured from the injection port 2 into the cavity between the insert b and the first mold 1 to perform molding. To operate the mold clamping mechanism 14, as shown in FIG. The mold is clamped by pulling it down in the direction of the clamping guide 13 on the mold 5 side (in the direction of arrow B), and while the lever 17 is being pulled down, the T-shaped end of the holder pin 20 engages with the locking end 15, and then Next, coil spring 21
is compressed against its elasticity, and each mold 1, 4, 5 is compressed by using the elastic return force of the coil spring 21.
It is something that tightens the gap. Therefore, the clamping force depends on the elastic force of the coil spring 21, and the mold clamping force can be adjusted by appropriately selecting and using the coil spring 21 or the spacer 22. Further, as shown in FIG. 4, if a male thread is provided on the entire surface of the pillar part of the holder pin 20 and a nut 25 is screwed in place of the spacer 22, the holder pin 20 of the nut 25
It becomes possible to adjust the mold clamping force due to the elasticity of the coil spring 21 by simply changing the screwing position.

When a molding material is injected into the clamped mold after adjusting the clamping force of the coil spring 21 in this way, the pressure of the injected molding material (cavity internal pressure) is applied to the coil spring 21.
If the tightening force is greater than the
Between the first type 1 and the second type 4 or between the first type 1 and the third type 5
Either or both of the molding materials are pushed open by the pressure, and an excess amount of molding material flows out. After that, the mold is again clamped by the coil spring 21, and as a result, the inside of the cavity is The pressure is always maintained at a constant pressure during several molding cycles, and the dimensional stability of the molded product can be improved.

As explained above, the present invention provides at least two substantially lid-shaped second and third types that are removably attached to both open ends of a first type of through-hole that is approximately cylindrical and are closely opposed to each other. A pair of tightening guides are arranged in series, and a mold clamping mechanism using spring means is provided at the proximal end of both clamping guides, and the pressure in the cavity is made constant by clamping the mold using the elasticity of the spring means, Excellent effects can be obtained in improving the dimensional stability of molded articles (products). Further, the mold of the present invention has features such as eliminating the need for a press device and reducing processing costs, and the practical effects of the present invention are extremely large.

[Brief explanation of the drawing]

The drawings show an embodiment of the mold according to the present invention, and FIG. 1 is a partially cutaway front view of the mold, and FIG.
FIG. 3 is an explanatory diagram showing how the mold is attached in a clamped state to the second mold, FIG. 3 is an explanatory diagram showing the operation of the mold, and FIG. 4 is a sectional view of the main part of the mold clamping mechanism. 1... 1st type, 2... Inlet, 3, 6, 7...
Through hole, 3a, 3b... open end, 4... second type,
5...3rd type, 8, 9...O ring, 10, 13
...Tightening guide, 14...Mold tightening mechanism, 15
... Locking end, 16 ... Actuation part, 17 ... Lever,
19... Spring holder, 20... Holder pin, 21... Coil spring, 23, 25...
Nut, a... Core rod, b... Insert, c...
resin material.

Claims (1)

[Scope of utility model registration request] A second type and a third type having a substantially lid shape are detachably attached to both open ends of the first type through hole having a substantially cylindrical shape.
1. A molding die characterized in that each of the molds is provided with at least two pairs of clamping guides facing each other in close proximity, and a mold clamping mechanism using spring means is provided at the proximal end of both clamping guides.