JPH0976236A - Mold structure - Google Patents

Abstract

(57) [PROBLEMS] To provide a mold structure in which both an ejector pin and a temperature control fluid passage can be provided in a mold for molding a molded product having a bag-shaped portion. SOLUTION: This is a mold structure in which a temperature control fluid is circulated inside a mold member 9 which constitutes a mold 20, and ejector pins 5 for releasing a molded product 1 from the mold 20 and ejector pins 5 are provided. And a first fluid passage 7 that is formed in the interior of the container for allowing the temperature control fluid to flow therethrough.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold structure for circulating a temperature control fluid inside a mold member that constitutes a mold.

[0002]

2. Description of the Related Art Generally, a mold for molding a plastic product is constructed as shown in FIG. In FIG. 5, a mold 20 is provided with a support plate 15 that supports the mold as a whole, and the support plate 15 and the movable side mold plate 1.
0 is moved up and down to perform the mold clamping and the mold opening, the movable side mold plate 10 placed on the upper and lower same mechanism 17, and the lower side arranged in the movable side mold plate 10. Pattern piece 9,
A fixed-side mold plate 13 arranged on the movable-side mold plate 10;
An upper mold piece 14 arranged inside the fixed-side mold plate 13 and an upper plate 16 that supports the fixed-side mold plate 13 are roughly configured. A cavity 19 for molding molten plastic is formed between the upper mold piece 14 and the lower mold piece 9, and the lower mold piece 9 and the movable side mold plate 10 are penetrated into the cavity 19. An ejector pin 5 is provided so as to be able to move in and out so that the molded product can be released from the mold. The ejector pin 5 is supported by the ejector plates 3 and 4. The lower mold piece 9 is formed with a conduit 18 for circulating a temperature control fluid for controlling the temperature of the mold.

In the conventional die having such a structure, for example, when a bag-shaped molded product as shown in FIG. 1 is formed, the round ejector pin 5 protruding from the bag-shaped bottom plate portion and the die It is difficult in terms of space to simultaneously provide a pipeline for circulating the temperature control fluid for controlling the temperature, and as shown in Fig. 5, the temperature control was abandoned (that is, the temperature control fluid is not contained in the bag-shaped portion). The mold design was performed with priority to the mold release (no pipeline was provided). Further, when temperature control is prioritized, a method has been adopted in which the tips 1a of the ribs forming the bag shape are projected with a square ejector pin, and a thin tube baffle, a heat pipe, or the like is provided in the shape portion 1b that becomes the bag.

[0004]

However, when a mold design giving priority to mold release is performed, the temperature of the bag-shaped portion cannot be controlled sufficiently, so that the temperature unbalance with other temperature controlled portions is not achieved. However, there is a problem in that the deformation occurs, the deformation becomes large, and the molding time becomes long.

Further, in order to balance the temperature, when the tips 1a of the ribs forming the bag shape are projected by a square ejector pin and a thin tube baffle or heat pipe is arranged in the shape portion 1b which becomes the bag, the baffle diameter becomes small. If it becomes too much, the temperature control medium will not flow sufficiently and the expected temperature control effect will not be obtained, or a large number of corner ejector pins will be arranged to guide the temperature control fluid to the baffle and heat pipe. There was a problem that it could not be secured easily.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object thereof is to provide both a ejector pin and a temperature control fluid passage in a mold for molding a molded product having a bag-shaped portion. It is to provide a mold structure that can be provided.

[0007]

In order to solve the above problems and achieve the object, a mold structure according to the present invention is a mold structure in which a temperature control fluid is circulated inside a mold member constituting a mold. And a ejector pin for releasing a molded product from the mold, and a first fluid passage formed inside the ejector pin for circulating the temperature control fluid. There is.

Further, the mold structure according to the present invention is characterized by further including a second fluid passage provided between the die member and the ejector pin and communicating with the first fluid passage. .

Further, in the mold structure according to the present invention, the second fluid passage is open to the outside of the mold.

Further, the mold structure according to the present invention further comprises a third fluid passage communicating with the second fluid passage, and the temperature control fluid is provided through the third fluid passage to the mold. It is characterized by being guided to the outside of.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the following embodiments, the structure of the mold has many parts in common with the conventional mold shown in FIG. 5, so the corresponding parts are designated by the same reference numerals and the description thereof is omitted.

(First Embodiment) FIGS. 2 and 3 are partial sectional views showing a structure near a cavity 19 in a mold structure according to this embodiment. The mold shown in FIGS. 2 and 3 is for performing the molding process of the molded product 1 having the bag-shaped portion as shown in FIG.

In FIGS. 2 and 3, 2 is a nipple attached to the mold side for supplying low temperature air from the outside, 3 is a lower ejector plate, 4 is an upper ejector plate, and 5 is a molded product 1. It is an ejector pin for releasing. 6 is processed into the lower ejector plate 3, and the nipple 2 serves as an inlet for low temperature air.
Is a low temperature air flow path connecting the ejector pin 5 with the ejector pin 5.
A vertical hole communicating with the flow path 6 is formed in the ejector pin 5 as a flow path 7 for low-temperature air up to a position close to the molded product 1, and the tip end thereof communicates with the horizontal hole 8. A clearance 11 is provided between the ejector pin 5 and the lower mold piece 9 and the movable side mold plate 10, and the low temperature air flowing into the ejector pin 5 through the flow path 7 passes through the lateral hole 8. , Is jetted into the clearance 11. As a result, the lower mold piece 9 existing in the bag-shaped portion 1b of the molded product 1
Part is cooled. The lower end of the clearance 11 is open to the atmosphere as shown in FIG. 3, and the low temperature air jetted into the clearance 11 is released into the atmosphere.

In the above structure, the low-temperature air flowing in from the nipple 2 flows to near the molded article 1 through the flow paths 6 and 7, so that the ejector pin 5 is formed.
Is cooled to the tip thereof, and the ejector pin 5 and the lower mold piece 9 fitted thereto are also cooled at the same time, so that the bag-shaped portion of the molded product 1 can efficiently remove heat. That is, the temperature imbalance between the molded product 1 and a portion other than the bag-shaped portion can be eliminated.

Although the cooled low-temperature air is released into the atmosphere through the clearance 11, in the case of this embodiment, since the low-temperature air is used as the cooling medium,
There is no effect if this leaks outside. Therefore, it is not necessary to use a sealing material such as an O-ring and it is not necessary to collect the medium, so that the mold structure can be simplified.

(Second Embodiment) FIG. 4 is a view showing the mold structure of the second embodiment. In the second embodiment, a liquid such as oil is used as the temperature control medium. In contrast to the first embodiment in which air is used as the temperature control medium, liquid is used as the temperature control medium, so the medium must be leaked and recovered. Therefore, as shown in FIG. 4, 0 ring 1
The structure 2 prevents the medium from leaking, and allows the medium to escape from the movable-side mold plate 10 to the outside of the mold to collect the medium. With such a structure, it can be applied even when a liquid is used as the medium.

Further, in the first and second embodiments,
It is also possible to forcibly suck the temperature control medium from the nipple 2. Especially when liquid is used as the medium as in the second embodiment, the force suction does not require a leak prevention member such as an O-ring. It can also be a structure.

The present invention can be applied to a modified or modified version of the above embodiment without departing from the spirit of the present invention.

[0019]

As described above, according to the present invention,
In contrast to the mold structure where it is difficult to control the temperature due to the ejector pin, by using a structure that allows the temperature control medium to flow through the ejector pin itself, no extra space is required and the mold release and mold temperature control It is possible to satisfy the key at the same time.

In particular, when a gas is used as the temperature control medium for cooling the mold, it is not necessary to prevent the medium from leaking and to recover the medium, so that the mold structure is very simple.

By thus sharing the temperature control circuit with the ejector pin, there is no mold release defect and the temperature distribution of the mold can be made uniform, which is very effective in shortening the molding cycle and preventing deformation of the molded product.

[0022]

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a molded product having a bag-shaped portion.

FIG. 2 is a partial cross-sectional view showing a structure near a cavity in the mold structure according to the first embodiment.

FIG. 3 is a partial cross-sectional view showing a structure in the vicinity of a cavity in the mold structure according to the first embodiment.

FIG. 4 is a partial cross-sectional view showing a structure near a cavity in the mold structure according to the second embodiment.

FIG. 5 is a schematic view showing a conventional mold structure.

[Explanation of symbols]

 1 Molded product 3 Lower ejector plate 4 Upper ejector plate 5 Ejector pin 9 Lower mold piece 10 Movable side mold plate 13 Fixed side mold plate 14 Upper mold piece 15 Support plate 16 Upper plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Nodera 347 Tomo, Ina-cho, Tsukuba-gun, Ibaraki

Claims (4)

[Claims] 1. A mold structure for circulating a temperature control fluid inside a mold member constituting a mold, comprising an ejector pin for releasing a molded product from the mold, and an ejector pin formed inside the ejector pin. And a first fluid passage for circulating the temperature control fluid. 2. The mold structure according to claim 1, further comprising a second fluid passage provided between the die member and the ejector pin and communicating with the first fluid passage. . 3. The mold structure according to claim 2, wherein the second fluid passage is open to the outside of the mold. 4. A third fluid passage further communicating with the second fluid passage, wherein the temperature control fluid is guided to the outside of the mold through the third fluid passage. The mold structure according to claim 2.