JPH05261737A - Mold clamping device of molding machine - Google Patents

Abstract

PURPOSE:To miniaturize the above mold clamping device, save the energy, enhance the cycle of a molding process and enhance the molding accuracy. CONSTITUTION:The moving frame 16 arranged so as to be held between the fixed frame 12 and support frame 14 connected by a tie bar 18 can be moved in the axial direction by the tie bar 18 piercing the end part of the frame 16 and a friction type clamp device 26 capable of clamping the moving frame 16 and the tie bar 18 is provided to the tie bar piercing hole part of the frame 16. A cylinder hole 27 for a connection piston and a cylinder hole 35 for a mold clamping cylinder are formed to the moving frame 16 and respectively have the connection piston 28 and the mold clamping piston 36 movable in the axial direction. The connection piston 28 is connected to the pressure receiving plate 32 having the moving mold 42 arranged in opposed relation to the fixed mold 44 of the fixed frame 12 and the mold clamping piston 36 can press the pressure receiving plate 32. A mold opening and closing cylinder 22 having a piston rod 24 capable of moving the moving frame 16 in the axial direction is provided to the support frame 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for a molding machine.

[0002]

2. Description of the Related Art A conventional mold clamping device for a molding machine is basically mounted on a fixed frame by directly compressing a moving frame by a dedicated large cylinder although there are differences in mechanism and structure. It has a structure to clamp the mold. As an example, FIG. 2 shows a mold clamping device having a horizontal structure. The upper half of this figure shows the state during mold clamping, and the lower half shows the maximum retracted state after mold opening. Cylinder frame 5 to the left and right of moving frame 50
2 and the fixed frame 54 are arranged. Four tie bars 56 are inserted through the ends of these frames, and nuts 58 are provided at both ends of the tie bars 56 protruding from the end surfaces of the cylinder frame 52 and the fixed frame 54, so that each frame and the tie bar 56. And are combined. These form a mold clamping frame portion. A cylinder hole is formed in the cylinder frame 52, and a piston 64 is fitted into the cylinder hole, whereby the cylinder hole is divided into a mold clamping side oil chamber 62 and a mold opening side oil chamber 67. The cylinder claim 52 and the piston 64 form a mold clamping cylinder. An oil supply port 60 is formed at the left end of the cylinder frame 52 in the figure, and pressure oil can be supplied from this to the mold clamping side oil chamber 62. An oil supply port 65 is formed at the right end of the hydraulic cylinder 62 in the figure, and pressure oil can be supplied from this to the mold opening side oil chamber 67.
A moving die 66 is provided on the surface of the moving frame 50 facing the fixed frame 54.
A fixed mold 68 is provided on the surface facing the moving frame 50. During mold clamping, pressure oil is supplied from the oil supply port 60 to the mold clamping side oil chamber 62, and this hydraulic pressure causes the piston 64 to generate a force in the right direction in the drawing. As a result, the moving frame 50 moves toward the fixed frame 54, and the moving die 6 moves.
6 and the fixed mold 68 come into close contact (mold closing). After the mold is closed, pressure oil is continuously supplied from the oil supply port 60 to the mold clamping side oil chamber 62, and the pressure is raised to a predetermined pressure to move the movable mold 66 and the fixed mold 68.
Is tightened with a predetermined force (mold clamping). When the mold is opened, the pressure oil is released from the oil supply port 60 to an oil tank (not shown), the pressure oil is supplied from the oil supply port 65 to the mold opening side oil chamber 67, and the piston 64 is opened.
A hydraulic pressure is applied to the moving frame 50 to move the moving frame 50 toward the cylinder frame 52. Thereby, the mold closing, mold clamping, and mold opening operations can be performed.

[0003]

However, in the mold clamping device of the conventional molding machine described above, since the same mold clamping cylinder is used for moving the moving frame 50 at the time of mold clamping and mold opening, the moving frame 50 is moved. A large amount of pressure oil is required for moving the mold at a high speed, and a large amount of oil in the mold clamping cylinder requires a lot of time for pressurization until completion of mold clamping and depressurization after mold clamping. For this reason, there is a problem that the hydraulic system becomes large-sized and one molding cycle time becomes long. Further, after the mold clamping, the amount of compressed oil in the mold clamping cylinder is large at the time of molding load, so that the amount of piston retreat is large due to the oil damper effect, and the load acts over the entire length of the tie bar 56, so that the amount of expansion is large. Become. As a result, there is a problem that the mold opening is promoted and the molding accuracy of the molded product is deteriorated. The present invention aims to solve the above problems.

[0004]

The present invention solves the above problems by moving a moving frame by means of a fluid pressure cylinder device dedicated to mold opening and closing, and by performing mold clamping by means of a mold clamping piston other than this. .. That is, the mold clamping device of the molding machine of the present invention includes a fixed frame fixed to a fixed portion, a support frame arranged at a predetermined distance from the fixed frame, a tie bar connecting the fixed frame and the support frame, a fixed frame and a support. A movable frame which is arranged between the frames and is movable in the axial direction of the frame by being guided by a tie bar penetrating the end, a fixed mold fixed to the fixed frame, and a movement arranged at a position facing the fixed mold. In the one having a mold, a friction type clamp device is provided in the tie bar through hole portion of the moving frame, and the friction type clamp device switches the moving frame to move the tie bar. A pressure receiving plate having a connecting piston mounting hole is provided between the moving frame and the moving mold. In the moving frame, a cylinder hole for a connecting piston and a cylinder hole for a mold clamping cylinder are formed on the side of the moving frame facing the moving mold, and the moving frame is fitted in the cylinder hole for the connecting piston so as to be movable in the axial direction. And a mold clamping piston that is fitted in the cylinder hole for the mold clamping cylinder so as to be movable in the axial direction.The connecting piston is provided on the opposite side of the moving frame fitting side. A connecting portion is formed at the end, the connecting piston is connected to the pressure receiving plate by this connecting portion, the moving die is fixed to the pressure receiving plate, and the fluid pressure cylinder device is The force is capable of opening and closing the mold, but the size is set so that mold clamping is impossible.

[0005]

When the moving frame is advanced to close the mold, the friction clamp device is released, and pressure oil is supplied to the mold closing side oil chamber of the fluid pressure cylinder device connected to the moving frame. This causes the moving frame to move forward. For mold clamping, the friction type clamp device is operated to fasten the moving frame and the tie bar, pressure oil is supplied to the mold clamping cylinder cylinder hole of the moving frame, and the mold clamping piston is advanced to press the pressure receiving plate. This is performed by pressing the moving mold provided on this and the fixed mold provided on the fixed frame. When retracting the moving frame to open the mold, reduce the hydraulic pressure in the cylinder hole for the mold clamping cylinder to retract the mold clamping piston to eliminate the pressing force on the pressure receiving plate and release the friction clamp device. Supplying pressure oil to the mold opening side oil chamber of the fluid pressure cylinder device. This causes the moving frame to retract. Accordingly, the mold opening, mold clamping, and mold opening operations can be performed at high speed.

[0006]

EXAMPLE FIG. 1 shows an example of the present invention. In the figure, the upper half shows the state at the time of mold clamping, and the lower half shows the state at the maximum retracted position after mold opening. The fixed frame 12 and the support frame 14 are fixed on the base 10 (fixed portion) with a predetermined space. Fixed frame 12 and support frame 14
A moving frame 16 is provided between and, and four tie bars 18 are inserted through these frames so as to pass through the four corners of each. Each tie bar 1
Nuts 20 are provided at both ends of the tie bar 18, and thereby the tie bar 18 is fixed to the fixed frame 12 and the support frame 14, respectively. A die opening / closing cylinder 22 (fluid pressure cylinder device) for moving the moving frame 16 is fixed to the support frame 14. The piston rod 24 of the mold opening / closing cylinder 22 is connected to the moving frame 16. A sleeve-type friction clamp device 26 is provided in a through hole portion of the moving frame 16 through which the tie bar 18 penetrates. The friction type clamp device 26 can fasten and release the moving frame 16 and the tie bar 18.
A cylinder hole 27 for a connecting piston is formed inside the moving frame 16. Cylinder hole for connecting piston 2
A connecting piston 28 is fitted on the shaft 7 so as to be movable in the axial direction. A connecting portion 30 is formed at an end of the connecting piston 28 opposite to the side where the moving frame 16 is fitted. The connecting portion 30 is engaged with a connecting piston mounting hole 33 formed in a pressure receiving plate 32 that is adjacent to the surface of the moving frame 16 that faces the fixed frame 12 and is parallel to the surface. .. Connecting piston 2
8 is operable by an accumulator 34. A ring-shaped cylinder hole 35 for the mold clamping cylinder is formed in the center of the moving frame 16, and a mold clamping piston 36 is fitted in the ring-shaped cylinder hole 35 for the mold clamping cylinder. The mold clamping piston 36 can press the pressure receiving plate 32. The cylinder hole 35 for the mold clamping cylinder is provided with a hydraulic pump 4 through a valve 38.
It is connected to 0. The movable die 42 is provided on the surface of the pressure receiving plate 32 facing the fixed frame 12, and the fixed die 44 is provided on the surface of the fixed frame 12 facing the pressure receiving plate 32.

Next, the operation of this embodiment will be described.
When the mold clamping device is stopped in the mold open position shown in the lower half of the figure, the friction clamping device 26 is released.
When the mold is clamped, pressure oil is supplied to a mold closing side oil chamber (not shown) of the mold opening / closing cylinder 22, and the pressure oil is supplied to the piston rod 2
4 to move the moving frame 16 toward the fixed frame 12 from the mold open position shown in the lower half of the figure.
The moving frame 16 is moved by the piston rod 24 to a position where the moving mold 42 and the fixed mold 44 come into contact (mold closing). At this time, the pressure receiving plate 32 moves integrally with the moving frame 16. When the movable mold 42 and the fixed mold 44 are closed, the friction type clamp device 26 operates to fasten the movable frame 16 and the tie bar 18, and the valve 3
The pressure oil of the hydraulic pump 40 adjusted by 8 is supplied to the cylinder hole 35 for the mold clamping cylinder. As a result, the pressure receiving plate 32 is pushed toward the fixed frame 12 by the mold clamping piston 36. Therefore, as shown in the upper half of the figure, the pressure receiving plate 32 moves away from the moving frame 16 toward the fixed frame 12, whereby the moving mold 42 and the fixed mold 44 are clamped. At this time, the connecting piston 28 operated by the accumulator 34 moves in accordance with the amount of movement of the pressure receiving plate 32 pressed by the mold clamping piston 36, so that the pressure receiving plate 32 is always in a parallel positional relationship with the moving frame 16. Move while maintaining. In this state, a predetermined molding is injection-molded by injecting a molten molding material into a mold from an injection device (not shown). Next, when the moving frame 16 is retracted to open the mold, the hydraulic pressure in the mold clamping cylinder cylinder hole 35 is reduced to release the force with which the mold clamping piston 36 presses the pressure receiving plate 32 toward the fixed frame 12. At the same time, the connecting piston 28 is operated by the accumulator 34 to move the pressure receiving plate 32 toward the moving frame 16. As a result, the pressure receiving plate 32 moves in the direction of the moving frame 16 while always maintaining a positional relationship parallel to the moving frame 16, and a gap is formed between the moving mold 42 and the fixed mold 44. After that, the friction clamp device 26 is released, and the piston rod 24 is moved toward the support frame 14 by supplying hydraulic pressure to the die opening side oil chamber (not shown) of the die opening / closing cylinder 22. The moving frame 16 is retracted to the position shown in the lower half of the figure.

In the above embodiment, the connecting piston 28
Although the mold clamping piston 36 and the mold clamping piston 36 are separately provided, the present invention is not limited to this, and a single structure may be used for both.

[0009]

According to the present invention, mold opening and closing and mold clamping are performed by dedicated cylinders, respectively, and fastening and releasing of the moving frame and the tie bar are performed by the friction type clamp device. For this reason, a large cylinder that doubles as the mold opening / closing and the mold clamping is unnecessary, and the frictional resistance between the moving frame and the tie bar can be reduced. This makes it possible to downsize the cylinder for opening and closing the mold,
Therefore, the hydraulic power source can be downsized. Also,
It is possible to speed up the movement of the moving frame, that is, the mold opening / closing. The mold clamping is performed by the mold clamping piston built in the movable frame after the moving frame is moved and the tie bar is clamped, so that the mold clamping time can be shortened. Also,
Since the mold clamping force can be supported by two frames, the movable frame and the fixed frame, the mold clamping frame part can be downsized and the deformation amount of the mold clamping frame part at the time of mold clamping and molding can be reduced. You can do this
The molding accuracy can be improved. Therefore, it is possible to reduce the size of the mold clamping device and save energy, and to achieve a high cycle of the molding process and high accuracy of molding.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional example.

[Explanation of symbols]

 12 fixed frame 14 support frame 16 moving frame 18 tie bar 22 type opening / closing cylinder (fluid pressure cylinder device) 26 friction type clamp device 27 connecting piston cylinder hole 28 connecting piston 30 connecting portion 32 pressure receiving plate 33 connecting piston mounting hole 35 mold clamping cylinder Cylinder hole 36 Mold clamping piston 42 Moving mold 44 Fixed mold

Claims (1)

[Claims] 1. A fixed frame (12) fixed to a fixed portion (10), a support frame (14) arranged at a predetermined interval from the fixed frame (12), and the fixed frame (12) and the support frame (14) are connected to each other. A movable frame (16) that is disposed between the fixed tie bar (18) and the fixed frame (12) and the support frame (14) and is guided by the tie bar (18) that penetrates the end thereof and is movable in the axial direction thereof.
And a fixed mold (4
4) and a moving mold (4
2) and a mold clamping device for a molding machine, wherein the moving frame (16) is provided with a friction type clamp device (26) in a tie bar through hole portion thereof, and the friction type clamp device (26) is provided. Switch the moving frame (16) to move the tie bar (18).
A pressure receiving plate (32) having a connecting piston mounting hole (33) is provided between the moving frame (16) and the moving mold (42). (16) has a cylinder hole (27) for the connecting piston on the side facing the moving mold (42).
And a cylinder hole (35) for the mold clamping cylinder, respectively, and a connecting piston (28) fitted in the cylinder hole (27) for the connecting piston so as to be movable in the axial direction.
And a mold clamping piston (36) fitted in the cylinder hole (35) for the mold clamping cylinder so as to be movable in the axial direction, and the connecting piston (28) has a moving frame (16) for the same. ) A coupling portion (30) is formed at the end opposite to the mating side, and the coupling piston (2
8) is a pressure receiving plate (32) by the connecting part (30) of this.
The movable die (42) is connected to the pressure receiving plate (3
2) fixed to the above fluid pressure cylinder device (2
2) is a mold clamping device for a molding machine in which the force by which the mold can be opened and closed, but the mold clamping is not possible.