JPH0224650B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold, and more specifically, the present invention relates to a mold, and more particularly, it is possible to control the temperature of the mold with excellent stability, responsiveness, and economy by controlling only the insert having a cavity. The present invention relates to a molding die which is suitable for use in molding a wide variety of small quantities in which inserts are frequently exchanged.

In recent years, with the diversification of the uses of molded products and the reduction in the amount of molded product inventory, there has been a need for high-variety, low-volume production.In response to this demand, only the inserts are replaced, reducing mold change time. , reduction of mold costs,
Efficient use of mold stock space is being achieved by downsizing the mold.

On the other hand, in conventional mold temperature control, a temperature control circuit is provided in the mold body, and the temperature of the insert is indirectly controlled by heat conduction to the mold body.

However, because the mold body has a large heat capacity, it takes time for the mold to reach a predetermined temperature when the insert is replaced due to high-mix, low-volume production as described above, and it is difficult to adjust the insert's temperature to the responsiveness. It is not possible to precisely control the temperature, and furthermore, it is not desirable from an economic point of view to control the temperature of the entire mold.

The present inventors believed that it would be effective to directly control the temperature of the insert in order to overcome the drawbacks of the conventional mold temperature control, and therefore installed a temperature control circuit inside the insert. I installed it and tried supplying a heat medium.

Although such an insert can easily control the temperature of the insert, it becomes extremely complicated to connect the heat medium supply/discharge port to the temperature control circuit of the insert when replacing the insert. For this reason, it has been found that the insert cannot withstand industrial use unless the heat medium supply/discharge port can be easily connected when replacing the insert.

The present invention has been made in view of the above circumstances, and its purpose is to control the temperature of only the insert using a heating medium, thereby improving the stability and responsiveness of the temperature control of the mold.
It is an object of the present invention to provide a molding die which is not only economically efficient but also allows a heating medium supply/discharge port to be easily connected to a temperature control circuit of the insert when replacing the insert.

The feature is that in a mold consisting of a mold body in which a nest insertion recess is formed and an insert in which a cavity is formed and is positioned and fixed in the insert insertion recess, the wall surface of the insert insertion recess is A mold body that forms a part of the mold body and is provided with a fixture that is movable forward and backward relative to the wall surface of the mold and that presses the mold to position and fix the mold in the mold insertion recess; a temperature control circuit which is disposed inside and has an inlet/outlet for a heating medium formed on a wall surface of the insert corresponding to the moving direction of the fixing tool; a wall surface of the insert insertion recess corresponding to the moving direction of the fixing tool and the insert; A connecting part is provided on the wall surface and connects a heat medium supply/exhaust port to the inlet/outlet of the insert, and a heat insulating layer is formed on the mold body and covers around the insert inserted into the insert insertion recess. There is something to do.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a plan view showing the parting surface of one of the split molds, and the other mold is constructed in the same manner.

1 is a mold body, and 1a is a guide bar. A substantially square recess 1b is formed in the parting surface of the mold body 1, into which a insert to be described later is inserted. Also, of the inner walls of this recessed portion 1b, the lower inner wall in FIG. 1 has been removed and is open downward. Incidentally, among the inner walls of the recess 1b, the upper inner wall 1c and the left inner wall 1d serve as reference surfaces when fixing the insert.

Reference numeral 2 denotes a nest, which is formed into a substantially square shape that is slightly smaller than the recess 1b, and has a cutout at the lower right corner of FIG. 1 to press the insert 2 against the reference surface of the recess 1b. A pressing surface 2a is formed for this purpose. Further, this pressing surface 2a is an inclined surface that spreads outward from the parting surface toward the bottom surface, and prevents the insert 2 from lifting off from the parting surface when pressing this pressing surface 2a.

Note that this pressing surface 2a is preferably formed so that the bisectors of the interior angle formed by the reference surface are perpendicular to each other, but this is not necessarily the case. It is fine as long as it is on the same side.

A temperature control circuit 2b, which is a flow path for a heat medium, is formed inside the insert 2, and a heat medium is supplied to and discharged from the temperature control circuit 2b on the lower side of the insert 2 in FIG. A connecting tool 2c is provided to protrude.

Reference numeral 3 denotes a fixture for pressing and fixing the insert 2 into the recess 1b, and a hydraulic cylinder 3a attached to the mold body 1 causes the opening of the mold body 1 to be directed toward the insert 2. You can freely advance and retreat. On the surface of the fixture 3 facing the insert 2, a pressing portion 3b is located corresponding to the pressing surface 2a and comes into contact with the pressing surface 2a.
A connector 3c for connecting an external temperature controller or the like (not shown) is provided at a position corresponding to the connector 2c.

4 is a heat insulating layer made of asbestos, etc.;
As shown in the figure, it is provided in each mold body 1 of the split mold. This heat insulating layer 4 is formed on the mold body 1 by a block 4b fixed to the mold body 1 with bolts 4a so that the insert 2 does not come into direct contact with it. Note that the recess 1b is formed by the inner wall surface of the block 4b.

Then, the fixture 3 is moved back downwards,
Insert the insert 2 into the recess 1b so that its pressing surface 2a is at the lower right position, and then insert the hydraulic cylinder 3 into the recess 1b.
When the fixture 3 is raised by a, the pressing part 3b of the fixture 3 presses the pressing surface 2a of the insert 2, presses and fixes the insert 2 to the upper left corner of the recess 1b,
The fixture 3 and the connectors 3c and 2c of the insert 2 are connected, and the heat medium circulates in the temperature control circuit 2b, so that only the insert 2 is temperature-controlled.

Also, after filling the cavity with molten resin,
When cooling and solidifying the molten resin, the molten resin can be quickly cooled by circulating a cooling medium instead of a heat medium through the nested temperature control circuit 2b.

Even when such forced cooling is performed, the area around the insert is insulated by a heat insulating layer, so the insert can be cooled efficiently and other parts of the mold are not affected. influence can be prevented.

In this way, according to the present invention, a temperature control circuit is provided inside the insert and heat conduction between the insert and the mold body is cut off, so that the insert can be replaced frequently. However, the stability, responsiveness, and economic efficiency of the temperature control of the insert can be improved.

In addition, fittings for connecting the heating medium supply/discharge port to the temperature control circuit of the insert are provided on the wall surface of the insert and the pressing surface of the fixing device, so when replacing the insert, it is necessary to connect the heat medium supply/discharge port. can be easily performed, and replacement of nests can be easily performed.

Therefore, the molding die of the present invention can sufficiently withstand industrial use and can be suitably applied to a wide variety of small-lot production.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a parting surface of a molding die according to the present invention, and FIG. 2 is a sectional view taken along line AA. 1... Mold body, 1a... Guide bar, 1b...
... recess, 1c... upper inner wall, 1d... left inner wall,
2... Insert, 2a... Pressing surface, 2b... Temperature control circuit, 2c... Connecting tool, 3... Fixing tool, 3a... Hydraulic cylinder, 3b... Pressing part, 3c... Connecting tool,
4...Insulating layer, 4a...Bolt, 4b...Block.

Claims (1)

[Scope of Claims] 1. A molding die comprising a mold body in which a nest insertion recess is formed and an insert in which a cavity is formed and is positioned and fixed in the insert insertion recess, comprising: a mold body that forms a part of the wall surface of the insert, is movable forward and backward relative to the insert wall surface, and is provided with a fixture that presses the insert to position and fix the insert within the insert inserting recess; A temperature control circuit that is disposed inside the insert and has an inlet and an outlet for a heat medium on a wall surface of the insert that corresponds to the moving direction of the fixture, and a wall surface of the insert insertion recess that corresponds to the moving direction of the fixture. and a connection part provided on the wall surface of the insert and connecting the heat medium supply/exhaust port to the input/outlet of the insert, and a heat insulating layer formed on the mold body and covering around the insert inserted into the insert insertion recess. A molding die characterized by comprising: