JPS61228914A - Molding die - Google Patents

Abstract

PURPOSE:To contrive to shorten the molding cycle by a method wherein the temperature distribution of a cavity bushing is made freely controllable by heating or cooling some portion, in which material with the thermal conductivity better than that of the base material of the bushing is embedded or integrally joined, of the cavity bushing. CONSTITUTION:A cavity 1, which is formed in a shape same as that of a molded part, consists of a back plate 2, a core plate 3 and cavity bushings 4a and 4b. A hollow having a nearly T-shape in cross section is formed in the cavity bushing 4a. Material 9, the thermal conductivity of which is better than that of the base material of the cavity bushing 4a, is cast in said hollow to be made into an integral body with the cavity bushing 4a. In addition, some portion of the material 9 is protruded in an annular passage 7. The controlling of temperature even at the portion near the surface of the cavity 1 is possible by circulating temperature controlling medium 8 in the annular passage 7 through the material 9 with better thermal conductivity. Consequently, the temperature of the cavity 1 can be quickly controlled. Accordingly, the shortening of the molding cycle is possible.

Description

Detailed Description of the Invention (Technical field to which the invention pertains) This invention relates to a mold for forming at least a part of a cavity in a mold used for injection molding, transfer molding, press or die casting, etc. This invention relates to a molding die in which the temperature distribution of the cavity insert can be adjusted arbitrarily.

(Prior Art) Conventionally, molds for injection molding, die casting molds, etc. in which a part or all of the cavity is formed by a cavity insert are known. As shown in the figure, a temperature regulating annular passage 7 is formed in the cavity insert 4 m + 4 b, and a temperature regulating medium 8 for heating or cooling is circulated within the passage to regulate the temperature.

(Problems with the prior art) The conventional cavity inserts 4m and 4b are entirely made of the same material, and even if the arrangement of the annular passage 7 is appropriately selected, the temperature can be adjusted to an arbitrary temperature distribution**. In addition, since the inside of each cavity 1 is pressurized during molding, the annular passage 7 for temperature regulation cannot be provided too close to the surface of the cavity 1, so the temperature H of the cavity 1 is
Problems such as slowing down of heating or cooling speed and lengthening of the molding cycle were inevitable.

(Means for Solving the Problems) This invention provides injection acid formation in a part of a cavity insert 4 forming at least a part of a cavity l for molding a molded product by die casting or the like. A material (for example, aluminum, #F, silver, or an alloy thereof) 9 with better thermal conductivity than the base material (usually iron or iron alloy) is embedded by casting, welding, close fitting, screwing, etc. Or, by joining them together and heating or cooling a part of them with a temperature control medium such as water or oil or a heater, etc., it is possible to achieve an arbitrary green density IIRtIj of the cavity insert 4, and to adjust the shape or material of the molded product. (Example) Figure 1 shows the present invention. This shows an example implemented in an injection mold. 1 is a cavity formed in the same shape as the molded product, and the cavity 1 is formed by a batter plate 2, a core plate 3, and a cavity insert 4ml 4b. ing.

The pack plate 2 is attached to a fixed platen (not shown), and an injection device (not shown) is connected to the platen.

The cavity inserts 4 a * 4 b are combined with each other and formed integrally, and an annular seal 6 such as an O-ring is provided on the combined surface 1, and an annular passage 7 is provided on the combined surface sandwiched by the annular seal 6. The passage 7 is connected to a temperature regulating medium source (not shown), and the temperature regulating medium 8 is circulated therethrough.

Moreover, among the cavity inserts 4 a e 4 b,
A cavity having a substantially T-shaped cross section is formed in the cavity insert 4a on the side facing the cavity IK, and a material having higher thermal conductivity than the base material (for example, iron or iron alloy) of the cavity insert 4a is formed in this cavity. good materials (e.g. a.

Luminium, #! , silver, or an alloy thereof) 9 is integrally formed by casting, and a portion of this material 9 protrudes into the annular passage 7 .

The cavity inserts 4a, 4b are partially engaged with a cavity plate 5 provided on the outside thereof, and are integrally fixed to the pack plate 2 via the plate 5 with bolts or the like.

Furthermore, the core plate 3 is provided on the opposite side of the pack plate 2 with the cavity plate 5 interposed therebetween,
It forms one surface of the cavity L, and is connected to a movable platen (not shown), and by operating a mold R (not shown) and a closing mechanism, an interface P between the core plate 3 and the cavity inserts 4 a e 4 b is formed. Therefore, according to this embodiment, by circulating the temperature regulating medium 8 in the annular passage 7, the parting surface is used as a parting surface to open and close the mold, and the parting surface is used as a parting surface to open and close the mold. It is possible to control the temperature even in the part, and rapid temperature control (heating or cooling) of the cavity l is possible, and by appropriately selecting the shape of the material 9, the temperature distribution of the cavity insert 4a can also be adjusted to the shape of the molded product. Alternatively, it can be arbitrarily adjusted depending on the material.

Figures 2 to 4 show other embodiments in which the present invention is applied to injection molding molds, which are basically the same as the embodiment shown in Figure 1, so the same components have the same structure. We will omit detailed explanations and only explain the differences.

In the embodiment shown in FIG. 2, a cavity with a diamond-shaped cross section is formed in the cavity insert 4a, and a material 9 having better thermal conductivity than the base material of the cavity insert 4a is integrally cast into the cavity. Temperature control (heating or cooling) at the center in the horizontal direction shown in the diagram
This embodiment is different from the embodiment shown in FIG. 1 in that the temperature distribution of the cavity insert 4a is changed so that the temperature is faster and becomes slower toward the left and right ends.

Further, in the embodiment shown in FIG. 3, the cavity insert 4a is further
A modified T-shaped cavity is formed on the divided surface of the divided parts and combined with each other, and in this cavity there is a material having higher thermal conductivity than the base material of the cavity 4a having the same cross-sectional shape as the cavity. It is made of a good material 9 and joined together by welding, close fitting, screwing, etc., and as in the above two embodiments, a blind cavity is formed in the cavity insert 4a, and the Instead of casting the material 9 into the cavity, a groove of a desired shape is formed in advance on the dividing surface of the cavity inserts 4a and 4m', and when they are combined together, a modified T-shaped cavity is formed. Therefore, it is possible to form an accurate cavity, and since the material 9 to be integrally joined (embedded) in this cavity can be tightly fitted by combining the materials 9 that have been accurately molded in advance, the temperature distribution of the cavity insert 4a can be improved. It is possible to control accurately, and it can also be manufactured only by machining without going through a casting process.

Furthermore, in the embodiment shown in FIG. 4, a cavity having a deformed T-shape in cross section is formed in the cavity insert 43, and a material 9 having better thermal conductivity than the base material of the cavity insert 4a is cast into the cavity, and the material is integrally formed. At the same time, part of the material 9 is formed into the cavity insert 4.
The annular heater 1 is made to protrude into the annular passage 7 formed by K and is wound around the end thereof, and there is no need to circulate the Kl conditioning medium 8 in the Kll-shaped passage 7 as in the third embodiment. .

There is no need for a temperature control medium source or a seal 6, etc., which simplifies the structure of the mold and facilitates maintenance.

(Effects of the Invention) According to the present invention, a part of the cavity insert forming at least a part of the cavity is made of a material having better thermal conductivity than the base material of the cavity insert. Since it can be embedded or bonded to a part close to the cavity surface without being isolated from the cavity surface for a certain period of time like a temperature control medium passage, it is possible to quickly control the temperature of the cavity and shorten the molding cycle. 1. By selecting this shape appropriately, the temperature distribution of the cavity insert can be controlled arbitrarily, so the temperature distribution can be controlled to the optimum temperature depending on the shape or material of the molded product, so precision molding is also possible. have

[Brief explanation of the drawing]

1 to 4 are schematic cross-sectional views showing embodiments of the present invention in injection molding molds. FIG. 2 is a schematic cross-sectional view showing an example of a conventional mold. 1: Cavity 4 m + 4 b' Cavity member 7: Annular passage 8: Temperature control medium 9: Material with better thermal conductivity than the nesting base material lO: Heater Figure 1 Procedure Amendment (Method) 1985 July 5th, Manabu Shiga, Commissioner of the Japan Patent Office1, Indication of the case, Patent Application No. 1988-700222, Name of the invention, Forming Venus 3, Relationship with the person making the amendment Patent applicant address: Chiyoda-ku, Tokyo Otemachi 2-2-1 name
Name (210) Sumitomo Heavy Industries, Ltd. (and 1 other person) 4, Agent address: 2-2-1 Otemachi, Chiyoda-ku, Tokyo Sumitomo Heavy Industries, Ltd. June 25, 1985, 6, amended Subject 4, brief explanation of the drawing

Claims (1)

[Claims] A material with better thermal conductivity than the insert base material is embedded or integrally bonded to a part of the cavity insert that forms at least a part of the cavity for molding the molded product, and the part is heated or A mold for molding, characterized in that the temperature distribution of the cavity insert can be arbitrarily adjusted by cooling.