JPH07186215A - Die-clamping device - Google Patents

Abstract

PURPOSE:To ensure that the closing stroke of a die can be established adequately long without necessitating a boost cylinder having a long action stroke, and at the same time, the thickness of the die can be adjusted remarkably without the use of large-scale hydraulic device. CONSTITUTION:A die clamping device is equipped with a fixed die plate 1 which holds a fixed die 5, and a movable die plate 3 which holds a movable die 7, and is further equipped with a die-feeding means which moves the movable die plate 3 into a direction in which the plate 3 leaves and comes into contact with the fixed die plate 1 to perform the opening/closing operation of the die. In this die-clamping device activating the clamping of the die by a die clamping means, the movable die plate 3 is formed using a conductor, and electromagnetic coils 21, 23 are provided which give an electromagnetic repulsive force to the movable die plate 3 by instantaneous energization as a die feed means. The opening/closing action of the die is performed by the electromagnetic repulsive force generated by the electromagnetic coils 21, 23.

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 used in an injection molding machine, a die cast machine or the like.

[0002]

2. Description of the Related Art As a mold clamping device used in an injection molding machine, a die casting machine or the like, a fixed die plate for holding a fixed die and a movable die plate for holding a movable die are used. Cylinder (boost re-cylinder) moves the movable die plate in the direction of moving away from and in contact with the fixed die plate to close and open the mold, and the mold clamping hydraulic cylinder directly clamps the mold. A well-known type and a toggle type that perform all mold opening / closing movement and mold clamping of a moving die plate by a toggle link mechanism driven by a hydraulic cylinder or the like are well known.

[0003]

SUMMARY OF THE INVENTION A direct pressure type mold clamping device is
The mold opening / closing stroke can be set longer than that of the toggle type, but a boost cylinder having an operation stroke corresponding to the mold opening / closing stroke is required, and it is relatively coupled with the driving of the mold clamping hydraulic cylinder. A large hydraulic system is required, and the entire system becomes large.

In the toggle type mold clamping device, due to the motion of the link mechanism, the mold opening / closing stroke cannot be lengthened so much.
Moreover, the mold thickness controllability is lacking.

In any of the mold clamping devices, a tie bar fixed at one end to a fixed die plate is used as a reaction member to apply a mold clamping force between the movable die plate and the fixed die plate. Support,
The die plate and the like are required to have sufficient mechanical strength, and it is necessary to construct the entire device into a highly rigid structure. This causes an increase in size and weight of the entire apparatus, which hinders the compactness and weight reduction of the mold clamping device.

The present invention has been made by paying attention to the above-mentioned problems in the conventional mold clamping device, and the mold opening / closing stroke is sufficiently long without requiring a boost cylinder having a long operation stroke. It can be set and has excellent mold thickness adjustability, does not require a large-scale hydraulic device, etc., and the mold opening / closing speed can be made faster than before, and there is no need for the entire device to have a highly rigid structure. The object of the present invention is to provide a mold clamping device that has a high degree of freedom in designing a compact and lightweight structure.

[0007]

In order to achieve the above-mentioned object, a mold clamping device according to the present invention has a fixed die plate for holding a fixed die and a movable die plate for holding a movable die, In the mold clamping device, in which the movable die plate is moved in a direction in which the movable die plate is moved toward and away from the fixed die plate by the mold feeding means to close and open the mold, and the mold is clamped by the mold clamping means, the movable die plate is a conductor. And an electromagnetic coil for applying an electromagnetic repulsive force to the moving die plate by momentary energization as the mold feeding means, and at least one of a mold closing operation and a mold opening operation is performed by the electromagnetic repulsive force by the electromagnetic coil. It is characterized by doing.

Further, in the mold clamping device according to the present invention, the electromagnetic coils are arranged at each of the stroke end portion on the die opening side and the stroke end portion on the die closing side of the movable die plate, and the electromagnetic repulsive force by each electromagnetic coil causes The detailed feature is to perform the mold closing operation and the mold opening operation.

In the mold clamping device according to the present invention, the electromagnetic repulsive force of one of the electromagnetic coils arranged at each of the stroke end portion on the die opening side and the stroke end portion on the die closing side of the movable die plate. Is applied to the moving die plate as a driving force for the mold closing operation or the mold opening operation, and the electromagnetic repulsive force of the other electromagnetic coil is applied to the moving die plate as a braking force for decelerating and stopping. It has detailed features.

In order to achieve the above-mentioned object, the mold clamping device according to the present invention comprises magnetic field generating means for selectively magnetically attracting the fixed die plate and the movable die plate to each other by the mold clamping means. It is characterized by being. In this case, the magnetic field generating means may form a magnetic loop using a yoke including a mold as a magnetic path.

Further, the mold clamping device according to the present invention is a mechanical lock for removably fixing the movable die plate to the fixed die plate at a predetermined mold clamping start position which approaches or abuts the fixed die plate. Have means,
The mold clamping means is constituted by a mold clamping fluid pressure cylinder provided between the movable die plate and the movable mold or between the fixed die plate and the fixed mold.

[0012]

According to the above-described structure, the electromagnetic coil is instantaneously energized to generate an instantaneous strong magnetic field, which induces an eddy current in the moving die plate, thereby causing the electromagnetic coil to move. An electromagnetic repulsive force acts between the movable die plate and the movable die plate, and the electromagnetic repulsive force accelerates the movable die plate to move the movable die plate at high speed to open and close the mold, thereby performing a mold closing operation or a mold opening operation.

Further, at the time of opening / closing the die of the moving die plate by the electromagnetic repulsive force of one of the electromagnetic coils disposed at the stroke end portion on the die opening side and the stroke end portion on the die closing side of the moving die plate. When the other electromagnetic coil is momentarily energized, an electromagnetic repulsive force acts between this electromagnetic coil and the moving die plate as a braking force to decelerate and stop the moving die plate. The plate stops at a predetermined position, the mold is closed, and the mold opening is properly completed.

Clamping is performed by magnetic field generating means after completion of mold closing.
Alternatively, it is performed by the mold clamping fluid pressure cylinder in a state where the movable die plate is fixed to the fixed die plate at a predetermined mold clamping start position where the movable die plate approaches or abuts the fixed die plate by the mechanical locking means.

[0015]

Embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 show a first embodiment of the mold clamping device according to the present invention. In these drawings, reference numeral 1 indicates a fixed fixed fixed die plate, and reference numeral 3 indicates a movable die plate that is movable in the left-right direction in the drawings.

Fixed die plate 1 and movable die plate 3
Are arranged to face each other, and the fixed mold
And the movable die 7 are fixedly mounted.

One end of each of a plurality of linear shafts 9 is fixedly connected to the fixed die plate 1. Each of the linear shafts 9 extends in parallel with each other in the mold opening / closing direction (left-right direction in the drawing), and the other end thereof is fixedly connected to the cross end plate 11.

The movable die plate 3 is made of a conductor, is supported by a linear guide member 13 so as to be movable in the axial direction from the linear shaft 9, and is guided by the linear shaft 9 so that the fixed die plate 1 and the cross end plate 11 are joined together. Move between mold opening and closing.

A yoke member 15 is embedded in the supporting portion of the movable die 7 on the movable die plate 3, and the yoke member 15 is attached to both sides of the movable die 7 on the surface facing the fixed die plate 1. It has exposed magnetic bonding surfaces 17 and 19.

Electromagnetic coils 21 and 23 are fixed to the mutually facing surface portions of the fixed die plate 1 and the cross end plate 11, in other words, to the stroke end on the die closing side and the stroke end on the die opening side of the movable die plate 3, respectively. It is installed.

Yoke members 25 and 27 are embedded and mounted on the fixed die plate 1 at positions aligned with the magnetic bonding surfaces 17 and 19 on both sides of the support portion of the fixed die 5, respectively. 27 has magnetic bonding surfaces 29, 31 exposed at the surface facing the moving die plate 3 at one end.

The yoke members 25 and 27 are connected to the permanent magnet 3 at the other end.
They are opposed to each other with 3 in between. The permanent magnet 33 is a magnetic field generating means for clamping the mold, is attached to the rotation shaft 37 of the motor 35 and is rotatably supported by the rotation shaft 37, and is non-magnetic as shown in FIG. It is selectively located in either the operating position or the magnetic operating position as shown in FIG.

Next, the operation of the mold clamping device having the above structure will be described.

In the mold open state shown in FIG. 1, the movable die plate 3 is in contact with the stopper surface portion 11a of the cross end plate 11 and is in the initial position facing the electromagnetic coil 23 with a small gap, and Permanent magnet 33
Is in a non-magnetic operating position.

At the time of molding, in the mold opening state described above,
First, the electromagnetic coil 23 is momentarily energized. This energization causes the electromagnetic coil 23 to generate a momentary strong magnetic field, which induces an eddy current in the moving die plate 3,
A repulsive force is generated between this eddy current and the current flowing through the electromagnetic coil 23. Thereby, an electromagnetic repulsive force acts between the electromagnetic coil 23 and the movable die plate 3, and the electromagnetic repulsive force accelerates the movable die plate 3 to the fixed die plate 1 side to move the mold closing movement at a high speed.

The moving die plate 3 is the fixed die plate 1.
The electromagnetic coil 21 is momentarily energized at the stage of approaching. Due to this energization, the electromagnetic coil 21 instantaneously generates a strong magnetic field, and the strong magnetic field induces an eddy current in the moving die plate 3 to generate a repulsive force between the eddy current and the current flowing through the electromagnetic coil 21. Thereby, the electromagnetic coil 21
Electromagnetic repulsive force acts between the moving die plate 3 and the moving die plate 3, and the moving die plate 3 decelerates and stops due to the electromagnetic repulsive force.
The moving die 7 is prevented from colliding violently with the fixed die 5, and the die closing is completed.

Next, as shown in FIG.
This causes the permanent magnet 33 to rotationally move to the magnetic operating position.
As a result, the magnetic flux of the permanent magnet 33 causes the yoke members 25, 15,
27 to form a closed loop M having a magnetic path, and a magnetic bonding surface 29
, 17, 19 and 31 are magnetically attracted to each other, and the magnetic attraction force causes the fixed die plate 1 and the movable die plate 3 to be attracted to each other at their joint surface portions to perform mold clamping.

When the mold is opened after the completion of molding, first the motor 3
5, the permanent magnet 33 is returned to the non-magnetic operating position, whereby the closed loop M of the magnetic path due to the magnetic flux of the permanent magnet 33 is opened, and the mold clamping due to the magnetic attraction force is released.

Next, the electromagnetic coil 21 is instantaneously energized, and between the eddy current induced in the moving die plate 3 by the instantaneous strong magnetic field generated in the electromagnetic coil 21 by this energization and the current flowing in the electromagnetic coil 21. A repulsive force is generated, and an electromagnetic repulsive force acts between the electromagnetic coil 21 and the moving die plate 3. Due to this electromagnetic repulsive force, the moving die plate 3 is accelerated toward the cross end plate 11 side and moves to open the mold at a high speed.

When the moving die plate 3 approaches the cross end plate 11, the electromagnetic coil 23 is momentarily energized. A repulsive force is generated between the eddy current induced in the moving die plate 3 and the current flowing through the electromagnetic coil 23 by the instantaneous strong magnetic field generated in the electromagnetic coil 23 due to this energization, and the repulsive force is generated between the electromagnetic coil 23 and the moving die plate 3. Electromagnetic repulsion acts on. Due to this electromagnetic repulsive force, the movable die plate 3 is decelerated and stopped, and the movable die 7 is completely opened without colliding with the cross end plate 11 violently.

FIG. 3 shows a second embodiment of the mold clamping device according to the present invention. In FIG. 3, the parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals as those in FIGS. 1 and 2.

In this embodiment, a ring-shaped electromagnet 39 is used as the magnetic field generating means for clamping the mold. The electromagnet 39 is composed of an electromagnetic coil 41 and a yoke member 43, is embedded in the fixed die plate 1 so as to surround the fixed die 5 of the fixed die plate 1, and is exposed on the surface facing the moving die plate 3. It has a magnetic bonding surface 45.

A ring-shaped yoke member 47 is embedded and mounted on the movable die plate 3 so as to surround the movable die 7. The yoke member 47 has a ring-shaped magnetic bonding surface 49 exposed at a surface facing the fixed die plate 1 at a position aligned with the magnetic bonding surface 45.

In this embodiment, by energizing the electromagnetic coil 41, the electromagnetic coil 41 is excited, and a closed loop M having the yoke members 43 and 47 as magnetic paths is formed around the electromagnetic coil 41. .

As a result, the magnetic joining surfaces 45 and 49 magnetically attract each other, and the magnetic attraction force causes the fixed die plate 1 and the moving die plate 3 to attract each other at their joining surface portions, thereby performing mold clamping. Be seen.

The mold clamping is released by stopping the power supply to the electromagnetic coil 41.

Also in this embodiment, the mold closing operation and the mold opening operation of the movable die plate 3 are performed by the electromagnetic action of the electromagnetic coils 21 and 23 as in the above-described embodiments.

When the magnetic field generating means for clamping the die is the electromagnet 39, as shown in FIG. 4, the fixed die 5 and the movable die 7 form a part of the yoke, and the fixed die 5 and the movable die. Type 7
A closed loop M may be formed around the electromagnetic coil 41 so as to magnetically connect the and the yoke members 43 and 47.

In this case, a magnetic field acts on the cavity formed by the fixed mold 5 and the movable mold 7, and the plastic magnet having anisotropy (the magnetic powder added to the resin) is molded specially. It is performed without the need for anisotropy imparting means.

FIG. 5 shows a third embodiment of the mold clamping device according to the present invention. Note that, also in FIG. 5, portions corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIGS. 1 and 2.

In this embodiment, a mold clamping hydraulic cylinder 51 is provided on the movable die plate 3. The mold clamping hydraulic cylinder 51 is moved by the pistun rod 53 to move the mold 7.
Is movably supported in the mold clamping direction, and the cylinder chamber 5
The hydraulic pressure applied to the piston 5 urges the piston rod 53 against the spring force of the return spring 57 in the mold clamping direction (right side in the drawing).

A mechanical lock device 59 is attached to the movable die plate 3. The mechanical lock device 59 includes a cylinder member 61 fixed to the movable die plate 3, two pistun rods 63 provided back to back on the cylinder member 61, and a toothed engagement block 65 attached to the tip of the pistun rod 63. Have

In this mechanical lock device 59, hydraulic pressure is supplied to the cylinder chamber 67 so that the two pistun rods 63 move in a direction in which they are separated from each other against the spring force of the return spring 69, that is, in the vertical direction in the figure. , Under the completion of mold closing indicated by a virtual line in the figure,
The toothed engagement block 65 meshes with the tooth portion 71 formed on the linear shaft 9.

In this embodiment, similarly to the above-mentioned embodiments, the moving die plate 3 is moved by the energization of the electromagnetic coil 23 to close the die, and the moving die plate 3 is closed by the phantom line in the drawing. When the completion position is reached, hydraulic pressure is supplied to the cylinder chamber 67 of the mechanical lock device 59, so that the two pistun rods 63 move in directions away from each other against the spring force of the return springs 69, and the toothed engagement is achieved. The block 65 meshes with and engages with the tooth portion 71 of the linear shaft 9. As a result, the movable die plate 3 is fixedly connected to the linear shaft 9 and the fixed die plate 1.

In this state, hydraulic pressure is supplied to the cylinder chamber 55 of the mold clamping hydraulic cylinder 51 to urge the movable mold 7 in the mold clamping direction to perform mold clamping.

When the mold is opened after the completion of molding, first, the cylinder chamber 55 of the mold clamping hydraulic cylinder 51 is drained to release the mold clamping, and then the cylinder chamber 67 of the mechanical lock device 59 is drained to release the return spring 69. By the spring force of, the toothed engagement block 65 is separated from the tooth portion 71 of the linear shaft 9 to separate the moving die plate 3 from the linear shaft 9. After that, by energizing the electromagnetic coil 21, the moving die plate 3 moves to open the mold and returns to the original state.

FIG. 6 shows a modification of the embodiment shown in FIG. In this embodiment, the movable die 7 is fixedly mounted on the movable die plate 3, the fixed die plate 1 is provided with a mold clamping hydraulic cylinder 51, and the pistun rod 53 is attached with the fixed die 5.

Further, the mechanical lock device 59 is fixedly arranged at a fixed portion substantially integrated with the fixed die plate 1, and the toothed engagement block 65 is provided with a die closing position shown by a phantom line in the drawing, The movable die plate 3 is meshed with and engaged with the tooth portion 71 formed on the movable die plate 3.
Is fixedly connected to the fixed die plate 1.

Therefore, also in this embodiment, the same operation and effect as those of the embodiment shown in FIG. 5 can be obtained.

In the above, the present invention has been described in detail with respect to specific embodiments, but the present invention is not limited to these, and various embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

[0052]

As can be understood from the above description, according to the mold clamping apparatus of the present invention, the movable die plate is accelerated by the electromagnetic repulsive force of the electromagnetic coil, and the movable die plate moves to open and close the mold to perform the mold closing operation. Alternatively, since the mold opening operation is performed, the mold opening / closing stroke can be set sufficiently long without the need for a boost cylinder with a long operating stroke, and excellent mold thickness adjustment is obtained, and a large-scale hydraulic system is also required. There is nothing to do. Further, the mold opening / closing speed can be further increased as compared with the conventional one, and the higher mold opening / closing speed can improve the production efficiency such as molding.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a mold clamping device according to the present invention in a mold open state.

FIG. 2 is a schematic configuration diagram showing a first embodiment of the mold clamping device according to the present invention in a mold closed state.

FIG. 3 is a schematic configuration diagram showing a second embodiment of the mold clamping device according to the present invention in a mold closed state.

FIG. 4 is a schematic configuration diagram showing a modified example of the second embodiment of the mold clamping device according to the present invention in a mold closed state.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the mold clamping device according to the present invention in a mold open state.

FIG. 6 is a schematic configuration diagram showing a modified example of the third embodiment of the mold clamping device according to the present invention in a mold open state.

[Explanation of symbols]

 1 Fixed Die Plate 3 Moving Die Plate 5 Fixed Die 7 Moving Die 21, 23 Electromagnetic Coil 33 Permanent Magnet 39 Electromagnet 51 Clamping Hydraulic Cylinder 59 Mechanical Lock Device

Claims (4)

[Claims] 1. A fixed die plate for holding a fixed die and a movable die plate for holding a movable die, wherein the movable die plate is moved by a die feeding means in a direction in which the movable die plate is brought into contact with and separated from the fixed die plate. In the mold clamping device for performing mold closing and mold opening, and performing mold clamping by the mold clamping means, the movable die plate is composed of a conductor, and electromagnetic waves are applied to the movable die plate by momentary energization as the mold feeding means. A mold clamping device comprising an electromagnetic coil for applying a repulsive force, wherein at least one of a mold closing operation and a mold opening operation is performed by an electromagnetic repulsive force by the electromagnetic coil. 2. The electromagnetic coil is arranged at each of a stroke end portion on a mold opening side and a stroke end portion on a mold closing side of the movable die plate, and a mold closing operation and a mold opening operation are performed by an electromagnetic repulsive force of each electromagnetic coil. The mold clamping device according to claim 1, wherein 3. The electromagnetic repulsive force of one of the electromagnetic coils disposed at each of the stroke end portion on the mold opening side and the stroke end portion on the mold closing side of the movable die plate is used to perform a mold closing operation or a mold opening operation. The mold according to claim 2, wherein the moving die plate is applied as a driving force for operation, and the electromagnetic repulsive force of the other electromagnetic coil is applied to the moving die plate as a braking force for decelerating and stopping. Fastening device. 4. The mold clamping means is constituted by magnetic field generating means for selectively magnetically attracting the fixed die plate and the movable die plate to each other. The mold clamping device described.