JP2951944B1 - Press molding method and press molding equipment - Google Patents

Abstract

An uncured paste is dispersed in an ideal state in molding chambers of various shapes. A press molding method includes filling a molding chamber 2 of a pair of dies 1 with an uncured paste, clamping the dies 1 to form them into a predetermined shape in the molding chamber 2, and then forming the dies 1 Open and remove the molded product. In the press molding method, the uncured paste P is uniformly dispersed throughout the molding chamber 2 by inclining the pair of molds 1 relatively, and then the mold 1 is clamped and molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for injecting uncured paste such as molten plastic, uncured rubber and cement mortar into a mold and press-molding the same.

[0002]

2. Description of the Related Art FIG. 1 schematically shows the steps of a press molding method in which a molten plastic is injected into a mold and then pressed and molded. In this molding method, plastic is molded in the following steps. The plastic is heated and melted to form a molten plastic, which is an uncured paste, and is injected into the molding chamber 2 of the mold 1. Close mold 1
The uncured paste P is pressed and formed in the forming chamber 2.
The mold 1 is held in a clamped state, and the uncured paste P
To cool. The mold 1 is opened, and the cooled and cured plastic molded product S is taken out.

[0003] The press forming method for forming in the above steps is as follows.
Compared to injection molding in which molten plastic is pressed into a clamped mold, plastic can be molded at low cost. This is because the injection pressure of the molten plastic injected into the mold can be considerably reduced as compared with injection molding. In particular, since the injection pressure can be reduced, it is suitable for molding large plastic products. In addition, this method uses rubber,
It can also be used for molding mortar, concrete, etc.

[0004]

According to the above press molding method, when a molten plastic as an uncured paste is injected, a mold is moved in parallel to widen a molding chamber. This is because the uncured paste is smoothly injected into the molding chamber. In the apparatus of FIG. 1, after injecting the uncured paste P into the molding chamber 2, the upper mold 1 is lowered in parallel and clamped,
The uncured paste P is formed in the forming chamber 2. At this time,
It is necessary to design the mold 1 in consideration of the flow balance of the uncured paste P so that the uncured paste P can be uniformly filled in the entire molding chamber 2. However, in practice, it is difficult to always inject an uncured paste into a molding chamber having various shapes in an ideal state. In particular, it is extremely difficult to uniformly inject uncured paste into a large molding chamber or a long molding chamber. If the mold is forcibly clamped without uniformly filling the uncured paste in the molding chamber, the filling will be partially insufficient, and the filling will be excessive, resulting in warping and shrinkage due to residual stress and the like.

[0005] In order to improve the flow balance of the uncured paste injected into the molding chamber, a method has been developed in which the pressure of the paste injected into the molding chamber is detected, and the injection speed is controlled by this paste pressure. However, even with this method, uncured paste cannot be injected into molding chambers of various shapes in an ideal state.

Further, as described in Japanese Patent Application Laid-Open No. 5-301256, a technique has been developed in which a gate nozzle for injecting molten plastic into a molding chamber is improved. This gate nozzle has a structure in which molten plastic injected into a molding chamber is dispersed from a gate to the periphery. Even with this structure, it is extremely difficult to uniformly inject molten plastic into molding chambers of various shapes under ideal conditions.

[0007] The present invention has been developed for the purpose of solving such disadvantages. An important object of the present invention is to provide a press molding method and a press molding apparatus which can disperse an uncured paste in an ideal state in molding chambers of various shapes.

[0008]

According to the press molding method of the present invention, an uncured paste is filled in a molding chamber 2 of a pair of dies 1, and the dies 1 are clamped by a clamping cylinder 3 to form a molding chamber. This is an improved press molding method in which the mold 1 is opened and the molded product is released after molding and curing into a predetermined shape in 2.
In the press molding method according to the first aspect of the present invention, the uncured paste P is uniformly dispersed in the entire molding chamber 2 by relatively inclining the pair of molds 1, and then the mold is clamped and molded. I do.

Further, the press forming method according to claim 1 of the present invention.
The method is based on the uncured paste P injected into the molding chamber 2 and
Float the mold 1A and pour the uncured paste P
When entering, pull up the upper mold 1A and open the mold 1
Open cylinder 17 or back of mold cylinder 3
The pressure is controlled by the control valve 12 to control the pressure on the upper mold 1A.
By controlling the rise, the upper mold 1A is tilted at a predetermined inclination.
The uncured paste P
By controlling the movement, the molding chamber 2 is uniformly filled.

According to a second aspect of the present invention, an uncured paste is injected into a pair of molds, a mold clamping cylinder for clamping the molds, and a molding chamber of the mold. And an injection device 4 for performing the injection. In this press molding apparatus, the uncured paste P is injected into the molding chamber 2 of the mold 1 by the injection device 4, and the mold 1 into which the uncured paste P has been injected is clamped by the mold cylinder 3 to form the mold. I do. Furthermore, the press-molding apparatus, the mold clamping cylinder 3, it is connected so as to be pressed in a posture of tilting the mold 1.

[0011] Furthermore, the press molding apparatus of the present invention comprises:
The uncured paste P injected into the molding chamber 2 is used for the upper mold 1
Float A and inject uncured paste P
Using the control valve 12 to raise the upper mold 1A to be raised,
Mold opening cylinder that opens the mold 1 by pulling up the upper mold 1A
17 or controlled by back pressure of mold cylinder 3
To control the upper mold 1A to a predetermined inclination
Floating while controlling the flow of uncured paste P
The molding chamber 2 is uniformly dispersed and filled while controlling.

The press forming apparatus according to a third aspect of the present invention includes a position sensor 10 for detecting the positions of the pair of dies 1 in the pressing direction. The back pressure of the plurality of mold clamping cylinders 3 is controlled by the signal of the position sensor 10 to incline the mold 1 to a predetermined position.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. However, the following examples illustrate a press molding method and a press molding apparatus for embodying the technical idea of the present invention, and the present invention does not specify the method and apparatus as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”. However, the members described in the claims are not limited to the members of the embodiments.

The press forming apparatus shown in FIG.
And a lower mold 1B, a mold clamping cylinder 3 for clamping the mold 1, a hydraulic device 5 for supplying a pressurized oil pressure to the mold clamping cylinder 3, and a mold 1 And an injecting device 4 for injecting the uncured paste into the molding chamber 2. The uncured paste is a plastic that has been heated and melted. However, the present invention does not specify an uncured paste as a molten plastic. As the uncured paste, any paste that is cured in an uncured state, such as uncured rubber, cement, and mortar, can be used.

The mold 1 can be clamped by directly pressing the mold with the mold clamping cylinder 3. However, the apparatus shown in the figure employs the upper mold 1 A on the slide frame 6 and the lower mold 1 B on the fixed frame 7. , And the mold is clamped through the slide frame 6 and the fixed frame 7.

A pair of dies 1 including an upper die 1A and a lower die 1B have a molding chamber 2. The molding chamber 2 includes the upper mold 1
A is provided between the lower surface of A and the upper surface of lower mold 1B. The upper mold 1A and the lower mold 1B are not clamped, in other words, in a state where the upper mold 1A is slightly raised from the mold clamping position, the uncured paste P injected into the molding chamber 2 is exposed to the outside. The structure does not leak. For this reason, it has a structure in which the peripheral edge of the lower mold 1B is slid without any gap on the inner surface of the molding chamber 2 of the upper mold 1A. However, the sliding surfaces of the upper mold 1A and the lower mold 1B are designed as gaps that allow the internal air to be discharged when the uncured paste P is injected into the molding chamber 2 and when the mold is clamped.

In the mold 1 shown in the figure, a supply port 8 for injecting the uncured paste P is opened at the center of the lower mold 1B. The lower mold 1B is fixed to the fixed frame 7 such that the supply port 8 is connected to the resin hole 9 of the fixed frame 7.

The slide frame 6 has an upper mold 1A on the lower surface.
And the lower end of the mold clamping cylinder 3 is connected to the upper surface. As shown in the plan view of FIG. 3, the slide frame 6 balances and connects the four mold clamping cylinders 3 to the upper surface. It is not always necessary to provide four mold clamping cylinders 3. This is because the slide frame can be pressed by two mold clamping cylinders. However, since a single clamping cylinder cannot support or press the slide frame in a state of being inclined at a predetermined angle, at least two, that is, a plurality of clamping cylinders 3 are connected to the slide frame 6. . Although not shown, the upper end of the mold clamping cylinder 3 is connected to the main body frame of the press forming apparatus.

The fixed frame 7 is fixed horizontally to the main body frame. The fixed frame 7 connects the resin hole 9 to the injection device 4.

The hydraulic device 5 has a position sensor 10 for detecting the position of the upper mold 1A via the slide frame 6, and a control for controlling the back pressure and the pressing pressure of the mold clamping cylinder 3 by the signal of the position sensor 10. The circuit includes a circuit 11, a control valve 12 controlled by the control circuit 11, and a hydraulic pump 13 for supplying a hydraulic pressure of a predetermined pressure to the control valve 12. The illustrated hydraulic device 5 controls the pressure of the mold clamping cylinder 3 by using a servo valve as the control valve 12,
As the control valve 12, a high-speed on / off valve, an electromagnetic proportional valve, a control valve, or the like can be used instead of the servo valve.

The position sensors 10 are arranged at four corners of the slide frame 6 as shown by solid lines in FIG. 3, or at both ends as shown by chain lines. In FIG. 3, the four sets of position sensors 10 arranged at the four corners can three-dimensionally detect the vertical and horizontal inclinations of the slide frame 6, that is, the horizontal attitude of the slide frame 6. Two sets of position sensors 10 provided at both ends detect only the left and right inclinations of the slide frame 6 in FIG.

The position sensor 10 detects a relative inclination between the upper mold 1A and the lower mold 1B. The illustrated position sensor 10
Detects the inclination of the upper mold 1A via the slide frame 6. The position sensor 10 can also directly detect the inclination of the upper mold 1A. Further, the relative inclination between the upper mold 1A and the lower mold 1B can be detected. The position sensors 10 are preferably arranged at four corners of the slide frame 6 as shown by solid lines in FIG. 3 to detect inclinations of the upper mold 1A and the lower mold 1B in the x-axis direction and the y-axis direction. I do. As indicated by the chain line, the position sensors 10 provided at both ends of the slide frame 6 can detect the inclination of the slide frame 6 in the x-axis direction, but cannot detect the inclination of the slide frame 6 in the y-axis direction.

The press forming apparatus of the present invention does not necessarily need to detect the inclination of the upper mold 1A and the lower mold 1B in the x-axis direction and the y-axis direction. For example, in FIG. 3, the mold 1 in the molding chamber 2 symmetrical with respect to the x-axis as a center line can uniformly fill the molding chamber 2 with the uncured paste P by controlling only the inclination in the x-axis direction. .

The position sensor 10 includes a slide frame 6
And anything that can detect the movement of the position of the upper mold 1A, etc.
For example, Magnescale (registered trademark) or the like can be used.

When injecting the uncured paste P into the molding chamber 2 or after injecting the uncured paste P into the molding chamber 2, the control circuit 11 controls the upper mold 1 A via the slide frame 6 in advance. The control valve 12 is switched so as to incline at the set angle.

The control circuit 11 determines that the gap between the upper mold 1A and the lower mold 1B becomes narrower in a portion where more uncured paste P is supplied, and that the upper mold is hardly injected with the uncured paste P. The pressing force of the mold clamping cylinder 3 is controlled via the control valve 12 so as to increase the distance between the mold 1A and the lower mold 1B.

In the illustrated control valve 12, the positions A, B and C of the plunger 12A are connected to the mold clamping cylinder 3. When the position A of the plunger 12A is connected to the mold clamping cylinder 3, the mold clamping cylinder 3 is connected to the oil tank 14 to reduce the back pressure of the mold clamping cylinder 3. Therefore, when the plunger 12A is at this position, the slide frame 6 is pushed up by the uncured paste P injected into the molding chamber 2. Plunger 12A
When the position B is connected to the mold clamping cylinder 3, the mold clamping cylinder 3 does not move, and the lifting of the slide frame 6 is stopped. Further, when the C position of the plunger 12A is connected to the mold clamping cylinder 3, the mold clamping cylinder 3 is connected to the hydraulic pump 13 and is pushed down.

Therefore, the control valve 12 shown in FIG.
Frame 6 with uncured paste P injected into
When raising the upper mold 1A and the plunger 12A
To the A position. Slide frame 6 and upper mold 1
When stopping A, the plunger 12A is switched to the B position. When the slide frame 6 and the upper mold 1A are lowered to press the uncured paste P in the molding chamber 2, the plunger 12A is switched to the C position. Therefore, the control circuit 11 switches the position of the plunger 12A to the position A, B, C to control the mold clamping cylinder 3, and the slide frame 6 and the upper mold 1 are controlled by the mold clamping cylinder 3.
The vertical position with respect to A is controlled.

The injection device 4 injects the uncured paste into a molding chamber 2 by heating and melting the plastic. The illustrated injection device 4 is an apparatus for injecting molten plastic. The injection device 4 heats the cylinder 15 with a heater (not shown) to melt the plastic, and extrudes the uncured paste P with a screw 16 arranged in the cylinder 15 to obtain a fixed amount of uncured paste. Is injected into the molding chamber 2. However, the injection device can also dispose a plunger in a cylinder to extrude a fixed amount of uncured paste. A cement or mortar injection device, which becomes an uncured paste without heating, does not require a heating mechanism.

FIGS. 4 and 5 show a press forming apparatus according to another embodiment. In the press forming apparatus shown in these figures, the injection device 4 is connected to the lower mold 1B without the intermediation of the fixed frame 7. Further, the apparatus shown in this figure is a mold opening cylinder 17 for lifting the mold 1 when removing the molded product.
Are connected to the upper surface of the slide frame 6. In this device, it is not necessary to lift the upper mold 1A with the mold clamping cylinder 3 and open the mold 1. The apparatus shown in FIG. 2 lifts the slide frame 6 with the mold clamping cylinder 3, opens the molding chamber 2, and removes the mold.

Further, in the apparatus shown in these figures, an opening / closing valve 18 is provided at the supply port 8 for injecting the uncured paste provided in the lower mold 1B. The on-off valve 18 is a lower mold 1
The supply port 8 is opened and closed by moving the valve body up and down by the opening and closing cylinder 19 provided in B. When the on-off valve 18 is opened, the uncured paste P is injected into the molding chamber 2, and when the on-off valve 18 is closed, the supply of the uncured paste P is stopped.

The above press forming apparatus forms an uncured paste in the following steps. The uncured paste P is injected into the molding chamber 2 of the mold 1 by the injection device 4. Molding room 2
The uncured paste P injected into the mold floats the upper mold 1A. At this time, the upward movement of the upper mold 1A is controlled by the mold clamping cylinder 3, and the upper mold 1A is controlled to float at a predetermined inclination, and the molding chamber is controlled while controlling the flow of the uncured paste P. 2. Fill uniformly. The back pressure of the mold clamping cylinder 3 is controlled by the control valve 12,
The upper mold 1A is controlled to have a predetermined inclination. The inclination of the upper mold 1A is detected by the position sensor 10. Therefore, the control circuit 11 controls the control valve 12 with a signal input from the position sensor 10, and controls the upper mold 1 </ b> A with the mold clamping cylinder 3 to a predetermined inclination.

When the position B of the plunger 12A is connected to the mold clamping cylinder 3, the control valve 12
To prevent the upper mold 1A from rising. When the position A of the plunger 12A is connected to the mold clamping cylinder 3, the back pressure decreases,
The upper mold 1A is raised. Therefore, the control valve 12
By connecting the position A or B of the plunger 12A to the mold clamping cylinder 3, the elevation of the upper mold 1A can be controlled. The control valve 12 is controlled by the control circuit 11 so that the plunger 12
Switch the position of A.

The inclination of the upper mold 1A can be controlled by a plurality of mold opening cylinders 17 instead of the mold clamping cylinders 3. The mold opening cylinder 17 is a mold clamping cylinder 3
To control the inclination of the upper mold 1A.

The above devices, the floating of the upper mold 1A is elevated in uncured paste P is injected, is controlled by the back pressure of the mold clamping cylinder 3, adjust the inclination of the upper mold 1A .

The uncured paste P is uniformly placed in the molding chamber 2.
After dispersing and injecting, the mold 1 is clamped by the mold clamping cylinder 3, and the uncured paste P is pressed and molded in the molding chamber 2. When clamping the mold 1, the control valve 12 connects the C position of the plunger 12 </ b> A to the clamping cylinder 3.

[0038] The mold 1 is held in a mold-clamped state to cure the uncured paste P, and then the mold 1 is opened,
Take out the molded product such as cured plastic.

In the above press molding method and press molding apparatus, the uncured paste P is uniformly injected into the molding chamber 2 by inclining the upper mold 1A with respect to the lower mold 1B. Although not shown, the lower mold may be inclined with respect to the upper mold, and the uncured paste may be uniformly injected into the molding chamber. Furthermore, it is also possible to inject the uncured paste uniformly into the molding chamber by tilting both the upper mold and the lower mold to control the relative inclination angle of both molds.

Further, in the above-described press forming method and press forming apparatus, the inclination of the mold 1 is controlled by the cylinder, and the inclination of the mold 1 is replaced with the cylinder as shown in FIGS. 6 and 7. Alternatively, it can be controlled by the cam 20 or the crank 21. The press forming apparatus shown in FIGS.
And the rotation angle of the crank 21 is controlled by a servo motor,
The inclination of the upper mold 1A is controlled.

[0041]

The press-forming method and press-forming apparatus of the present invention have a feature that the uncured paste can be dispersed in a molding chamber of various shapes in an ideal state. The reason is that the press molding method and the press molding apparatus of the present invention uniformly disperse the uncured paste injected into the molding chambers of the pair of molds by relatively inclining the molds. is there.
A relatively inclined mold is used to inject the uncured paste into the molding chamber when injecting the uncured paste into the molding chamber, or by injecting the uncured paste into the molding chamber after inclining. And can be uniformly dispersed without unevenness. Therefore, the molding method and apparatus of the present invention
Even in molding chambers of various shapes, the uncured paste is uniformly injected into the whole, effectively preventing partial underfilling or overfilling, and realizing high-quality plastic molded products.

Further, the press forming apparatus according to claim 5 is provided with a position sensor for detecting the position of the pair of dies in the pressing direction, and the signals of the position sensors control a plurality of mold clamping cylinders to form the dies. It is inclined to a predetermined position. Therefore, the relative inclination of the mold is accurately detected by the position sensor, and the plurality of mold cylinders are controlled more accurately.
The feature is that the mold can be tilted to the ideal state.

[Brief description of the drawings]

FIG. 1 is a schematic process diagram showing a conventional press molding method.

FIG. 2 is a schematic sectional view of a press forming apparatus according to an embodiment of the present invention.

FIG. 3 is a plan view of the press forming apparatus shown in FIG. 2;

FIG. 4 is a partial cross-sectional front view of a press forming apparatus according to another embodiment of the present invention.

FIG. 5 is a plan view of the press forming apparatus shown in FIG.

FIG. 6 is a partial cross-sectional front view showing another example of the mechanism for controlling the inclination of the mold.

FIG. 7 is a partial cross-sectional front view showing another example of the mechanism for controlling the inclination of the mold.

[Explanation of symbols]

1: Mold 1A: Upper mold 1B:
Lower mold 2 ... Molding chamber 3 ... Molding cylinder 4 ... Injection device 5 ... Hydraulic device 6 ... Slide frame 7 ... Fixed frame 8 ... Supply port 9 ... Resin hole 10 ... Position sensor 11 ... Control circuit 12 ... Control valve 12A ... Plunger 13 ... Hydraulic pump 14 ... Oil tank 15 ... Cylinder 16 ... Screw 17 ... Opening cylinder 18 ... Open / close valve 19 ... Open / close cylinder 20 ... Cam 21 ... Crank P ... Uncured paste S ... Plastic molded product

Claims (3)

(57) [Claims] An uncured paste is filled in a molding chamber (2) of a pair of molds (1), and the mold (1) is clamped by a mold clamping cylinder (3) to form an uncured paste. This is a press molding method in which a mold (1) is opened and a molded product is released after molding and curing into a predetermined shape in a chamber (2), and a pair of molds (1) are relatively inclined. In the press molding method of uniformly dispersing the uncured paste (P) in the molding chamber (2) and then clamping and molding, the uncured paste injected into the molding chamber (2) (P), upper mold
Float (1A) and inject uncured paste (P)
The upper mold (1A) and open the mold (1)
Open the cylinder of the mold opening cylinder (17) or the mold clamping cylinder (3).
Control pressure with the control valve (12) to control the upper mold (1A).
By controlling the rise, the upper mold (1A) is tilted at a predetermined angle.
Flow of uncured paste (P)
Press molding method characterized by uniformly filling the molding chamber (2) while controlling the pressure. 2. An uncured paste is injected into a pair of molds (1), a mold clamping cylinder (3) for clamping the mold (1), and a molding chamber (2) of the mold (1). An uncured paste (P) is injected into the molding chamber (2) of the mold (1) by the injecting device (4), and the uncured paste (P) is injected. In a press forming apparatus configured to mold the mold (1) with the mold clamping cylinder (3) to form an uncured paste and to cure the paste, the mold clamping cylinder (3) is connected to the mold (1). ) Are connected so that they can be pressed in an inclined position, and are not injected into the molding chamber (2).
When the upper mold (1A) is floated with the hardening paste (P),
Then, uncured paste (P) is injected and raised
When the mold (1A) rises, the upper mold (1A) is pulled by the control valve (12).
Mold opening cylinder (17) or mold to lift and open mold (1)
Control with the back pressure of the tightening cylinder (3)
The mold (1A) is controlled to a predetermined inclination and
And molding while controlling the flow of the uncured paste (P)
A press molding apparatus characterized in that the chamber (2) is configured to be uniformly dispersed and filled . 3. A position sensor (10) for detecting a position of a pair of dies (1) in a pressing direction.
Back pressure of multiple clamping cylinders (3)
3. The press molding apparatus according to claim 2 , wherein the mold is tilted to a predetermined position by controlling the mold.