JPS6222277Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to improvement of a molding die.

In conventional molding molds, oil 2' is sprayed into the mold from a nozzle 1' outside the mold, as shown in FIG. 4, in order to prevent the molded product from sticking to the mold.

However, in the above method, there is a risk that oil may be sprayed not only on necessary parts of the mold but also on unnecessary parts, and in that case, the unnecessary parts are contaminated.

On the other hand, if the above method is used to prevent oil from adhering to the unnecessary parts of the mold, there is a risk that the oil will not adhere to the necessary parts of the mold, and in that case, the molded product will bite into the mold. It was attached.

The present invention solves the above-mentioned problems, and allows oil supplied from outside the mold to flow to at least one of the circumferential surface of the extruded member whose lower edge is chamfered and the circumferential surface of the hole. By forming an oil groove extending downward, oil is deposited throughout the inside of the mold to prevent the molded product from sticking to the mold.

An embodiment of the present invention will be described below.

In FIG. 1, 1 is a mold, and the mold 1 is roughly composed of an upper mold 1a and a lower mold 1b.The lower mold 1b is fixed to a base 2, and the lower mold 1b is fixed to a vertically movable base 3. The upper mold 1a is designed to fit together,
When the two molds 1a and 1b are fitted together, a cavity 4 is formed inside by the upper mold 1a and the lower mold 1b. As a result, the product P is molded.

A hole 5 is formed in the upper die 1a, with one end facing the base 3 and the other end facing the cavity 4.
is composed of a hole 5a that extends downward from the base 3 with a constant diameter and a hole 5b that is narrower than the diameter of the hole 5a in the middle, and the hole 5a and the hole 5
The size of the diameter with respect to b forms a stepped portion 5c.

An extrusion member 6 is inserted into the hole 5 so as to be vertically movable, and an elastic urethane rubber 7 is interposed between the extrusion member 6 and the base 3. It acts as a buffer material.

Further, an oil supply hole 8 is formed in the upper mold 1a so that one end opens to the outside of the mold and the other end opens to the hole 5a, and one end of the oil supply hole 8 outside the mold has an oil reservoir (not shown). An oil supply hose 9 extending from (omitted) is connected.

As shown in FIGS. 2 and 3, the extrusion member 6 has a shape in which a disk portion 6a having approximately the same diameter as the hole portion 5a and a cylindrical portion 6b having approximately the same diameter as the hole portion 5b are integrated. , and the disc part 6a and step part 5c
The engagement with this serves as a stopper. A plurality of (four in the figure) oil grooves 6c are formed in parallel on the cylindrical portion 6b of the extrusion member 6 in the longitudinal direction of the circumferential surface, and a chamfer is formed on the periphery at the end of the extrusion member 6 on the cavity 4 side. A chamfered portion 6d is formed.

A hole 10 is formed in the lower mold 1b, facing the hole 5 of the upper mold 1a and also continuous with the base 2. An extrusion member 11 is inserted into the hole 10 so as to be movable up and down. A urethane rubber 12 is interposed between the extrusion member 11 and the base 2, and the urethane rubber 12 serves as a cushioning material for the extruded member 11.

Next, the operation of the above configuration will be explained.

Before extrusion, as shown on the right side of FIG. 1, the chamfered portion 6d is inside the cavity 4 and is not in contact with the peripheral wall of the cavity 4. Further, the stepped portion of the hole 5 and the stepped portion of the extruding member 6d are in contact with each other, so that the opening of the oil supply hole 8 is closed by the circumferential surface of the extruding member 6d.

The left side of the figure shows the state during extrusion, where a gap is formed between the step of the hole 5 and the step of the extrusion member 6d, and the opening of the oil supply hole 8 is not closed. Further, the chamfered portion 6d is in contact with the peripheral wall of the cavity 4.

Therefore, oil is not supplied to the peripheral wall of the cavity 4 before extrusion, but during extrusion it is supplied as described below.

First, oil in an oil reservoir (not shown) is supplied to the hole 5a through the oil supply hose 9 and the oil supply hole 8 by the position head.

The oil supplied to the hole 5a is carried downward through a plurality of oil grooves 6c, and the oil is conveyed downward through the chamfered portion 6d of the extrusion member 6.
reach. Incidentally, the oil supplied to the hole 5a can also be forcibly pushed out into the plurality of oil grooves 6c as the pushing member 6 moves downward. The oil that has reached the chamfered portion 6d wraps around the entire circumference of the chamfered portion 6d due to surface tension, and then moves downward from the chamfered portion 6d due to gravity and spreads uniformly throughout the mold.

Thereafter, the product P is produced by performing molding as before, and the product P is extruded from the upper and lower molds 1a and 1b using the extrusion members 6 and 11.

The present invention is not limited to the above embodiments, but also includes the following.

The oil groove 6c is formed by the hole 5a instead of the extrusion member 6.
Alternatively, it may be formed in both the hole portion 5a and the columnar portion 6b.

The oil groove 6c may be inclined or formed in a spiral shape. As a result, the length of the oil groove 6c extending to the cavity 4 is increased, so that oil is well distributed to the contact surface between the hole portion 5b and the cylindrical portion 6b, and the vertical movement of the extrusion member 6 is smoothed.

The cross section of the hole is not limited to a circle, but may also be a polygon such as a square or rectangle, or a circular shape.

Instead of supplying oil from an oil sump via a position head, a forced transport means such as an oil pump may be provided.

As is clear from the above description, the present invention can reliably prevent the product from sticking to the mold because the oil spreads uniformly over the necessary parts of the mold.

In addition, the oil supply hole opens only during extrusion, and the chamfered portion contacts the peripheral wall of the cavity only during extrusion, and these movements are brought about by the vertical movement of the extrusion member, so the minimum amount of oil required is automatically supplied. will be supplied to

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a front view showing the extrusion member, Fig. 3 is a side view of Fig. 2, and Fig. 4 is a conventional embodiment. FIG. 1a... Upper die, 1b... Lower die, 4... Cavity, 5... Hole, 6... Extrusion member, 6c... Oil groove, 6d... Chamfered portion, 8... Oil supply hole.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of an upper mold and a lower mold, the upper mold has a hole formed with a stepped portion extending vertically from outside the mold into the inside of the mold. In a molding die in which an extrusion member having a movable step is inserted and a gap is formed between the step of the hole and the step of the extrusion member during extrusion, an opening is formed in the upper die into the hole from outside the mold. An oil supply hole is provided for supplying oil into the gap between the step parts during extrusion, and a peripheral edge of the lower end of the extrusion member is chamfered, and a circumferential surface of the extrusion member and a circumferential surface of the hole are chamfered. An oil groove extending downward is formed in at least one of the extrusion members, and the chamfered portion of the extrusion member is located within the cavity in which the product is installed before extrusion,
A molding die characterized by being in contact with the peripheral wall of a cavity during extrusion. (2) The utility model claimed in claim 1, in which a plurality of the oil grooves are formed. (3) The oil groove according to any one of claims 1 to 2 of the utility model registration claim is formed at an angle.