JPH01202414A - Resin molding device - Google Patents

Abstract

PURPOSE:To constitute the title device so that clogging at a sliding part of a plunger with dregs is not generated, by a method wherein a manifold having a second cylinder coaxial with a first cylinder communicating with a cavity is provided on a template freely elevatably. CONSTITUTION:A pot 4a (first cylinder) communicating with a cavity 3 through a passage 6 is formed on a bottom force 2c facing on a top force 1c. A manifold 9 which is freely elevatable to the bottom force 2c is mounted on an ejector plate 10 which is freely elevated by a driving device. A pot 11 (second cylinder) which is coaxial with a pot 4a is formed on the manifold 9. The pot 11 is communicated with a low pressure hydraulic pressure source for pressure control through a hydraulic pressure circuit 12 and the pot 4a and pot 11 which are coaxial with each other are fitted slidably with a plunger 5a in common with them. As inner pressure within the first cylinder is set at a constant value, pressure to be applied to resin become constant, the stroke of a piston is long and clogging with dregs on the inside of the pot is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin molding device that injects resin into a cavity formed between a pair of upper and lower templates to mold the resin.

[Prior art]

2 and 3 are front sectional views showing a conventional resin molding apparatus.

In the case of the apparatus shown in FIG. 2, cavities 3.3. ... is formed to form a cylindrical bot 4. The resin contained in the plunger 58
By injecting the resin into the cavity 3 through the passage 6, the resin is molded according to the shape of the cavity 3.

In this case, the resin molded product is produced by retracting the upper mold 11 upward and retracting the lower mold 28 downward.
It is ejected from both molds by being pushed by an eject pin 7 or by ejection using a hydraulic ejector.

Furthermore, in the conventional resin molding apparatus shown in FIG.
I, bot set up in [l'J4. A pot similar to the above is also formed in the lower mold 2t, and a plunger 5t for pressure adjustment is installed inside this pot. This plunger 5b is supported so as to be biased with a pressing force lower than the pressure of the plunger 58, and adjusts the pressure change of the resin in the bond 41 due to the pressing force of the plunger +51, and adjusts the pressure inside the pot 41. It is supported so that it can be raised and lowered by a small amount to keep it constant.

In this case, in order to take out the molded resin product,
The upper mold II and the plunger 5 are released upward, and the resin molded product is extruded by the plunger 56 with the lower mold 2b fixed.

In reality, the cavities 3 and bonds 48 described above are often constructed as a multi-plunger type in which a large number of them are provided in one upper or lower mold as shown in FIG. It is necessary to eliminate variations in pressure, and 51. is for that purpose.

[Problem to be Solved by the Invention] Among the conventional resin molding devices described above, in the one shown in FIG. 2, the plunger is ll[! jL is not necessary, and it is organized into a simplified device that is low in cost.
As mentioned above, especially the multi-plunger type,
Bond 4. The disadvantage is that the pressure inside cannot be adjusted when it is necessary to adjust it.

Furthermore, in the conventional device shown in FIG.
1.51+ are required, and two pots are also required to accommodate the plungers, and these plungers and pots are made of expensive materials such as B hard alloy to prevent wear. There is a problem of high cost. In addition, since the plunger 5 for pressure adjustment only moves by a minute amount in response to pressure fluctuations inside the pot 4&, as described above, slag of the resin material is deposited on the sliding end 8 of the plunger 5b with respect to the pot 4a. There is a problem in that the inside of the pot 4 □ must be cleaned frequently because of stickiness and clogging of the plunger 5 .

Therefore, it is an object of the present invention to provide a resin molding device which reduces costs by omitting plungers and pots as much as possible, and which is easy to maintain and does not cause clogging of slag in the sliding portion of the plunger. That's true.

[Means to solve the problem]

In order to achieve the above object, the main means adopted by the present invention is that in a resin molding device that molds by injecting resin into a cavity formed between a pair of upper and lower templates, A first cylinder communicating with the cavity is formed in the mold plate, and a manifold having a second cylinder coaxial with the first cylinder is provided so as to be movable up and down with respect to the mold plate, and the first cylinder A common piston is slidably attached to the first and second cylinders, and the manifold is raised by the lifting drive means! 1', and the piston is urged toward the mold plate by hydraulic means with a driving force smaller than the driving force of the elevating driving means.

[Effect]

When the manifold is raised in the direction of the template by the lifting means while keeping the pressure in the second cylinder at a predetermined pressure,
The piston rises in response to the internal pressure within the second cylinder. Since the piston is installed coaxially within the first cylinder, as the piston moves upward, the resin contained within the first cylinder is injected into the cavity, and resin molding is performed.

Even if the manifold is moved toward the template more than necessary due to the force of the elevating drive means, the pressure applied to the resin remains constant because the internal pressure in the first cylinder that pushes the piston is adjusted to be constant.

When the resin molding is completed, the upper mold is opened upward, and the manifold is raised while keeping the oil pressure of the second cylinder constant, thereby pushing up the piston and taking out the resin molded product. After removal, the manifold is lowered and the oil pressure of the second cylinder is returned to the set oil pressure.

〔Example〕

Next, an embodiment embodying the present invention will be described with reference to FIG. 1 to provide an understanding of the present invention. FIG. 1 is a front sectional view of a resin molding apparatus according to an embodiment of the present invention.

In the following description of the embodiment, the same reference numerals are used for elements common to those shown in FIGS. 2 and 3.

Further, the following examples are merely examples embodying the present invention, and are not intended to limit the technical scope of the present invention.

In the embodiment shown in FIG. 1, the lower mold 2 facing the upper mold IC
The bot 4 communicates with the cavity 3 through the passage 6.
(first cylinder) is formed. The manifold 9, which can be raised and lowered with respect to the lower die 2c, is placed f2 on an ejector plate 10 that is driven up and down by a lifting drive means (not shown). The manifold 9 has the bot 41
A cylinder 11 (second cylinder) coaxial with the cylinder is formed.

11 is in communication with a low pressure hydraulic source for pressure adjustment through a hydraulic circuit 12.

Said coaxial bot4. and bot 11 have a plunger 5. is slidably attached.

Further, a plurality of guide pins 13, 13. ... is slidably attached to the manifold 9, and the manifold 9 is attached to the lower mold 2C.
This is intended to guide you. A return spring 14 is provided between the lower mold 2C and the manifold 9 to bias the manifold 9 in a direction away from the lower mold 2c.

When performing resin molding in the resin molding apparatus A as described above, first, the upper mold IC and the lower mold 2c are closed as shown in the figure, and the pressure in the bond 11 is set to a predetermined pressure, and in that state, as shown in the figure. The ejector plate 10 is raised by a lifting drive means such as a hydraulic cylinder or a screwdriver, and the manifold 9
push up.

This allows plunger 5. bot 4 due to the hydraulic pressure in bond 11. It slides inside and rises. The resin in the bond 41 is injected into the cavity 3 through the passage 6 as the plunger 51 rises, and is molded.

When the resin molding is completed, the upper mold 1c is retracted upward, and the manifold 9 is further raised by raising the ejector plate IO while keeping the oil pressure of the bot 11 constant. This allows plunger 5. The resin product is extruded from the lower mold 2c and taken out of the mold.
Next, by moving the ejector plate IO downward, the manifold 9 is returned to its original position by the spring 14.

At this time, the hydraulic fixation of the bot 11 is also released.

In the above embodiment, the manifold 9 was moved upward in order to take out the resin molded product, but the plunger 5 was moved by the hydraulic pressure inside the bot 11 while the manifold 9 remained fixed
．． Alternatively, the resin molded product may be taken out by raising the temperature.

〔Effect of the invention〕

As described above, the present invention provides a resin molding apparatus that performs molding by injecting resin into a cavity formed between a pair of upper and lower templates, in which a first cylinder communicating with the cavity is connected to one of the templates. A manifold having a second cylinder coaxial with the first cylinder is provided so as to be movable up and down with respect to the mold plate, and a piston common to the first cylinder and the second cylinder is slidably movable. The manifold is driven up and down by an up/down driving means, and the piston is urged toward the template by a hydraulic means with a driving force smaller than the driving force of the up/down driving means. Since this is a resin molding device, only one piston and one bot are required for one set of cavities, so there is no increase in cost, and since the pressure of the piston can be adjusted, the pressure inside the bot can be adjusted. can be adjusted appropriately, and variations in molded products can be absorbed. In addition, since the piston is used not only to adjust the internal pressure inside the pot as described above, but also to inject resin and take out molded products, its stroke is large, causing problems such as slag clogging in the pot. was also resolved.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a resin molding device according to an embodiment of the present invention, FIGS. 2 and 3 are front sectional views of a conventional resin molding device, and FIG. 4 is a multi-plunge type resin molding device. FIG. 2 is a schematic plan view showing the concept of FIG. [Explanation of symbols] IC... Upper die 2c... Lower die (template plate) 41... Pot (first cylinder) 3... Cavity 5,... Plunger (piston) 9... Manifold 11... Pot (second cylinder) 10... Ejector plate 12... Hydraulic circuit 13... Guide pin 14... Return spring. Applicant: Zaiyo Seisakusho Co., Ltd.

Claims (1)

[Scope of Claims] A resin molding device for molding by injecting resin into a cavity formed between a pair of upper and lower templates, wherein a first cylinder communicating with the cavity is formed in one of the templates, A manifold having a second cylinder coaxial with the first cylinder is provided so as to be movable up and down with respect to the template, and a common piston is slidably attached to the first cylinder and the second cylinder, The resin molding is characterized in that the manifold is driven up and down by an up/down drive means, and the piston is urged in the direction of the template by a hydraulic means with a driving force smaller than the driving force of the up/down drive means. Device.