KR20130103416A - Injection molding machine and driving apparatus - Google Patents

Abstract

PURPOSE: An injection molding machine and a driving device are provided to miniaturize a driving circuit by commonly using a single driving part to be connected to one side of two electromagnets. CONSTITUTION: An injection molding machine comprises an electromagnet for generating a mold clamping force and a driving device for driving the electromagnet. The driving device includes first and second driving parts (101,102). The first driving part is installed in each electromagnet by being connected to one end of the electromagnet. The second driving part is commonly connected to the other end of each electromagnet. [Reference numerals] (63) Current command calculating unit; (64) Current control unit; (65) PWM signal generating unit; (66) AD converting unit; (AA) Command

Description

[0001] Injection molding machine and driving apparatus [0002]

The present application claims priority based on Japanese Patent Application No. 2012-051301 filed on March 8, 2012. The entire contents of which are incorporated herein by reference.

The present invention relates to a driving apparatus for driving a plurality of electromagnets and an injection molding machine having the same.

Conventionally, in an injection molding machine, a resin is injected from an injection nozzle of an injection apparatus, filled in a cavity space between a stationary mold and a movable mold, and solidified to obtain a molded article. Then, a mold clamping device is arranged to perform mold closing, mold clamping and mold opening by moving the movable mold with respect to the stationary mold.

The mold clamping device includes a hydraulic type mold clamping device driven by supplying oil to the hydraulic cylinder and an electric mold clamping device driven by the electric motor. The electric mold clamping device has high controllability and does not contaminate the periphery , And is also widely used because of its high energy efficiency. In this case, a thrust is generated by rotating the ball screw by driving the electric motor, and the thrust is enlarged by the toggle mechanism to generate a large mold clamping force.

In the electromechanical mold clamping apparatus of this configuration, since the toggle mechanism is used, it is difficult to change the mold clamping force due to the characteristics of the toggle mechanism, the response and stability are poor, and the mold clamping force can not be controlled during molding. Therefore, there is provided a mold clamping device capable of directly using a thrust generated by a ball screw as a mold clamping force. In this case, since the torque of the electric motor and the clamping force are proportional, the clamping force can be controlled during molding.

However, in the conventional mold clamping apparatus, the ball screw has low resistance to load, can not generate a large mold clamping force, and the mold clamping force fluctuates in accordance with the torque ripple generated in the motor. Further, in order to generate the mold clamping force, it is necessary to always supply the electric current to the electric motor, so that the electric power consumption and the heat generation amount of the electric motor become large, so that the rated output of the electric motor needs to be increased as much as possible, and the cost of the mold clamping apparatus becomes high.

Therefore, a mold clamping apparatus using a linear motor for mold opening / closing operation and using the attraction force of electromagnet for mold clamping operation is considered (for example, Patent Document 1).

WO 05/090052 Pamphlet

However, for example, in the case of driving a plurality of electromagnets, a driving unit is required for each electromagnet, so that the driving unit having such a driving unit is enlarged, and further, the injection molding machine having the driving unit becomes large.

Therefore, it is an object of the present invention to provide an injection molding machine and a driving apparatus in which a driving section for driving a plurality of electromagnets is miniaturized.

In order to achieve the above object,

A plurality of electromagnets for generating a mold clamping force, and a drive device for driving the electromagnets,

The drive device,

A first driving part provided for each of the electromagnets and connected to one end of each electromagnet,

And a second driving unit commonly connected to the other ends of the electromagnets.

According to another aspect of the present invention,

A driving device for driving a plurality of electromagnets,

A first driving part provided for each of the electromagnets and connected to one end of each electromagnet,

And a second drive unit commonly connected to the other end of the electromagnet.

According to the present invention, the driving unit for driving the plurality of electromagnets can be downsized.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a mold clamping device in an injection molding machine according to an embodiment of the present invention. Fig.
Fig. 2 is a view showing the mold-starting state of the mold clamping apparatus in the injection molding machine according to the embodiment; Fig.
Fig. 3 is a plan view of the rear platen on which the coils are disposed, as viewed from the adsorption plate side in the mold-clamping direction.
4 is a cross-sectional view along line CC of Fig.
5 is a configuration example of a driving apparatus according to an embodiment.
6 is a configuration example of a driving apparatus according to an embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described according to drawing. However, in the present embodiment, the moving direction of the movable platen when mold closing is referred to as the forward direction and the moving direction of the movable platen when the mold opening is performed is referred to as the rear direction, The moving direction of the screw at the time of injection is referred to as forward and the direction of movement of the screw at the time of metering is referred to as rear.

Fig. 1 is a view showing a state of a mold clamping apparatus in an injection molding machine 1 according to an embodiment of the present invention when the mold clamping apparatus is closed. Fig. 2 is a cross- Fig. However, in Figs. 1 and 2, the hatched member shows a main cross section.

Reference numeral 10 denotes a mold clamping apparatus; Fr, a frame of the injection molding machine 1; Gd, a guide movable relative to the frame Fr; 11, Fr is a fixed platen which is spaced apart from the stationary platen 11 and is opposed to the stationary platen 11 so that the rear platen 13 And four tie bars 14 (only two of the four tie bars 14 are shown in the figure) are arranged between the stationary platen 11 and the rear platen 13. [ However, the rear platen 13 is fixed with respect to the frame Fr.

A screw portion (not shown) is formed at the front end portion (the right end portion in the drawing) of the tie bar 14 and the nut n1 is screwed to the threaded portion to tighten the front end portion of the tie bar 14, (11). The rear end portion of the tie bar 14 is fixed to the rear platen 13.

The movable platen 12 is arranged so as to be able to move forward and backward in the mold opening / closing direction so as to face the fixed platen 11 along the tie bar 14. [ As a result, the movable platen 12 is fixed to the guide Gd, and a guide (not shown) for passing the tie bar 14 through the movable platen 12 at a position corresponding to the tie bar 14 A hole is formed. However, instead of the guide hole, a cutout may be formed. However, the suction plate 22 to be described later is also fixed to the guide Gd.

The fixed platen 11 is fixed to the fixed platen 15 and the movable platen 12 is fixed to the movable platen 12. The movable platen 12 is movable relative to the stationary mold 15 The mold 16 is connected and separated, and mold closing, mold clamping, and mold clamping are performed. A cavity not shown is formed between the stationary mold 15 and the movable mold 16 and the unillustrated resin injected from the injection nozzle 18 of the injection apparatus 17 is injected into the cavity The space is charged. The mold apparatus 19 is constituted by the stationary mold 15 and the movable mold 16.

The attracting plate 22 is fixed to the guide Gd in parallel with the movable platen 12. As a result, the attracting plate 22 can move forward and backward from the rear platen 13. The attracting plate 22 may be formed of a magnetic material. For example, the attracting plate 22 may be constituted by an electromagnetic laminated steel sheet formed by laminating a thin plate made of a ferromagnetic material. Alternatively, the adsorption plate 22 may be formed by casting.

The linear motor 28 is installed in the guide Gd to move the movable platen 12 forward and backward. The linear motor 28 includes a stator 29 and a mover 31. The stator 29 is mounted on the frame Fr in parallel with the guide Gd and on the movable platen 12 and the mover 31 is formed to face the stator 29 at the lower end of the movable platen 12 and over a predetermined range.

The mover (31) has a core (34) and a coil (35). The core 34 has a plurality of magnetic pole teeth (magnetic pole teeth) 33 protruding toward the stator 29 and formed at a predetermined pitch, and the coils 35 are wound around the magnetic pole teeth 33 . However, the stimulating teeth 33 are formed parallel to each other in a direction perpendicular to the moving direction of the movable platen 12. [ The stator 29 has a core (not shown) and a permanent magnet (not shown) extending on the core. The permanent magnet is formed by alternately magnetizing the magnetic poles of the N pole and the S pole. When the linear motor 28 is driven by supplying a predetermined current to the coil 35, the movable member 31 is advanced and retreated, whereby the movable platen 12 is advanced and retracted by the guide Gd, It is possible to perform mold opening.

However, in the present embodiment, the permanent magnet is arranged in the stator 29 and the coil 35 is arranged in the mover 31, but a coil may be arranged in the stator and a permanent magnet may be arranged in the mover. In this case, since the coil does not move as the linear motor 28 is driven, wiring for supplying electric power to the coil can be easily performed.

The movable platen 12 and the attracting plate 22 are not limited to the structure in which the movable platen 12 and the attracting plate 22 are fixed to the guide Gd. As shown in Fig. The mold opening / closing mechanism is not limited to the linear motor 28, and may be a hydraulic type or an electric type.

When the movable platen 12 is advanced and the movable mold 16 comes into contact with the stationary mold 15, the mold is closed and the mold is continuously formed. Between the rear platen 13 and the attracting plate 22, an electromagnet unit 37 for casting is disposed. A center rod rod 39 extending through the rear platen 13 and the attracting plate 22 and connecting the movable platen 12 and the attracting plate 22 is arranged to be movable forward and backward. The center rod 39 moves and retracts the attracting plate 22 in conjunction with the advancing and retreating movement of the movable platen 12 at the time of mold closing and mold starting to move the attracting force generated by the electromagnet unit 37 To the platen (12).

It should be noted that the mold clamping device 11 may be formed by the stationary platen 11, the movable platen 12, the rear platen 13, the attracting plate 22, the linear motor 28, the electromagnet unit 37, 10).

The electromagnet unit 37 has an electromagnet 49 formed on the side of the rear platen 13 and a suction portion 51 formed on the suction plate 22 side. Further, a coil groove 45 is formed around a predetermined portion of the rear end surface of the rear platen 13, in this embodiment, around the center rod 39. Then, the coil 48 is wound around the core 46 in the coil groove 45. However, the rear platen 13 may be constituted by an integrated structure of castings, or may be constituted by an electronic laminated steel sheet formed by laminating a thin plate made of a ferromagnetic material.

In this embodiment, the electromagnet 49 may be formed separately from the rear platen 13, and the adsorption portion 51 may be formed separately from the adsorption plate 22. The electromagnet 49 may be formed as a part of the rear platen 13, The adsorption section may be formed as a part of the adsorption plate 22. The arrangement of the electromagnet and the attracting portion may be reversed. For example, an electromagnet 49 may be provided on the suction plate 22 side and a suction portion may be provided on the rear platen 13 side. The electromagnet 49 may be provided on both the rear platen 13 side and the attracting plate 22 side. When the electromagnet is provided on the attracting plate 22 side, the coil constituting the electromagnet may be disposed in the coil groove formed on the attracting plate 22, for example.

In the electromagnet unit 37, when an electric current is supplied to the coil 48, the electromagnet 49 is driven, and the attracting portion 51 is attracted to generate a mold clamping force.

The center rod 39 is connected to the attracting plate 22 at the rear end and is connected to the movable platen 12 at the front end. Thus, the center rod 39 is advanced together with the movable platen 12 to advance the attracting plate 22 when the mold is closed, and retracted together with the movable platen 12 to retract the attracting plate 22 at the mold start . Thereby, in the central portion of the rear platen 13, a hole 41 for penetrating the center rod 39 is formed.

The driving of the linear motor 28 and the electromagnet 49 of the mold clamping apparatus 10 is controlled by the control section 60. [ The control unit 60 includes a CPU and a memory and includes a circuit diagram for supplying current to the coil 35 of the linear motor 28 and the coil 48 of the electromagnet 49 in accordance with the result calculated by the CPU Respectively. A load detector 55 is also connected to the control unit 60. [ The load detector 55 detects the load of the tie bar 14 at a predetermined position (a predetermined position between the stationary platen 11 and the rear platen 13) of the at least one tie bar 14 in the mold- And a load applied to the tie bar 14 is detected. In the figure, an example in which the load detector 55 is installed on the upper and lower tie bars 14 is shown. The load detector 55 is constituted by, for example, a sensor for detecting the amount of elongation of the tie bars 14. The load detected by the load detector 55 is sent to the control unit 60. However, the control unit 60 is omitted in FIG. 2 for the sake of convenience.

Next, the operation of the mold clamping apparatus 10 will be described.

The mold closing process is controlled by the mold opening / closing processing unit 61 of the control unit 60. 2, the mold opening / closing processing unit 61 supplies a current to the coil 35. In the state shown in Fig. Subsequently, the linear motor 28 is driven, the movable platen 12 is advanced, and the movable mold 16 is brought into contact with the stationary mold 15 as shown in Fig. At this time, a gap delta is formed between the rear platen 13 and the attracting plate 22, that is, between the electromagnet 49 and the attracting portion 51. [ However, the force required for mold closing is sufficiently small compared with the mold clamping force.

Subsequently, the mold-shape processing section 62 of the control section 60 controls the mold-clamping process. The mold clamping processing unit 62 supplies current to the coil 48 and sucks the attracting unit 51 by the attracting force of the electromagnet 49. [ As a result, the mold clamping force is transmitted to the movable platen 12 through the attracting plate 22 and the center rod 39, and mold clamping is performed. When the mold clamping force is changed, for example, at the start of mold clamping, the mold clamping unit 62 sets the value of the normal current necessary for generating the target mold clamping force in the normal (steady) state as a target to be obtained by the change And supplies it to the coil 48.

However, the mold clamping force is detected by the load detector 55. The detected mold clamping force is sent to the control unit 60. In the control unit 60, the current supplied to the coil 48 is adjusted so that the mold clamping force becomes the set value, and the feedback control is performed. During this time, the molten resin in the injection apparatus 17 is injected from the injection nozzle 18, and is filled in the cavity of the mold apparatus 19. [

When the resin in the cavity space is cooled and solidified, the mold opening / closing processor 61 controls the mold opening process. The mold clamping processing unit 62 stops the supply of current to the coil 48 in the state of Fig. As a result, the linear motor 28 is driven and the movable platen 12 is retracted, so that molds are performed as shown in Fig.

Hereinafter, the characteristic configuration of the present invention will be described with reference to FIG. 3 and subsequent figures.

3 is a plan view of the rear platen 13 on which the coils 48 are arranged, as viewed from the adsorbing plate 22 side in the mold-clamping direction. 4 is a cross-sectional view taken along line C-C of Fig.

As shown in Fig. 4, a plurality of coils 48 are stacked and arranged in the coil groove 45. As shown in Fig. However, the lamination direction corresponds to the depth direction Y of the coil groove 45. In the example shown in Fig. 4, two coils 48a and 48b are provided. The coil groove 45 is formed in a rectangular shape so as to surround the core 46. The two coils 48a and 48b are arranged in a rectangular shape so as to surround the core 46 by being stacked on the rectangular coil grooves 45. [

The electromagnet 49 is constituted by two electromagnets 49A and 49B. The electromagnet 49A is configured so as to include a core 46 and a coil 48a wound around the core 46. The electromagnet 49B includes a core 46 and a coil 46 wound around the core 46. [ (48b) are included.

However, the surface of the outer peripheral portion 47a of the core 46 and the rear platen 13 (the surface on the suction plate 22 side) may extend in the same plane to define a gap surface. The coil groove 45 has a bottom surface offset by a depth from the gap surface.

Fig. 5 is a configuration example of the control unit 60 shown in Fig. The control unit 60 is an embodiment of the driving apparatus of the present invention. The control unit 60 includes a converter 74, a DC link 80, a drive circuit 90, current sensors 67A and 67B, and a mold-

The converter 74 converts AC power flowing in the power supply line 75 into DC power and supplies the converted DC power to the DC link 80. The power supply line 75 is a wiring for connecting between the power supply 70 and the converter 74 and is constituted by three current paths of U, V, W, for example. The power source 70 is an AC power source installed outside the injection molding machine 1, such as a factory facility. The converter 74 may be, for example, a three-phase bridge circuit composed of six power transistors or a rectifier composed of a three-phase diode bridge including six diodes.

The DC link 80 is a DC power supply path portion provided between the DC output side of the converter 74 and the DC input side of the drive circuit 90. The DC link 80 includes a pair of DC power supply lines 81A and 81B and a smoothing capacitor 82, . The DC power supply lines 81A and 81B are transmission paths of DC current flowing between the converter 74 and the drive circuit 90 and the smoothing capacitor 82. [ The smoothing capacitor 82 is a capacitor for smoothing the DC voltage of the DC power supply lines 81A and 81B. As a concrete example of the smoothing capacitor 82, an electrolytic capacitor can be mentioned. The DC link voltage Vdc of the DC link 80 corresponds to the voltage across the smoothing capacitor 82.

The drive circuit 90 drives a plurality of electromagnets. In the drawing, two electromagnets 49A and 49B are illustrated. The drive circuit 90 controls the DC drive currents flowing through the respective coils constituting the plurality of electromagnets so as to independently adjust the magnitudes of the mold clamping forces that can be generated by the plurality of electromagnets, And controls the driving voltage of the applied direct current.

The drive circuit 90 has drive portions 101 and 102 as first drive portions provided for each electromagnet and connected to one end of each electromagnet. The driving portion 101 is connected to the end portion 111 of the coil 48a of the electromagnet 49A and the driving portion 102 is connected to the end portion 113 of the coil 48b of the electromagnet 49B. The drive circuit 90 has a drive unit 103 as a second drive unit commonly connected to the other end of each of the plurality of electromagnets (the end not connected to the first drive unit). The driving portion 103 is commonly connected to the end portion 112 of the coil 48a of the electromagnet 49A and the end portion 114 of the coil 48b of the electromagnet 49B.

The driving unit 101 includes a high side switch unit 91 connected to the high potential side DC power supply line 81A and a low side switch unit 94 connected to the low potential side DC power supply line 81B in series It has connected circuit. The intermediate node 97 to which the high side switch portion 91 and the low side switch portion 94 are connected is connected to the end portion 111 of the coil 48a through the current path 117. [

The driving unit 102 includes a high side switch unit 92 connected to the high potential side DC power supply line 81A and a low side switch unit 95 connected to the low potential side DC power supply line 81B in series It has connected circuit. The intermediate node 98 to which the high side switch portion 92 and the low side switch portion 95 are connected is connected to the end portion 113 of the coil 48b through the current path 118. [

The driving unit 103 is connected to the high side switch unit 93 connected to the high potential side DC power supply line 81A and the low side switch unit 96 connected to the low potential side DC power supply line 81B in series Circuit. The intermediate node 99 to which the high side switch part 93 and the low side switch part 96 are connected is connected to the end part 112 of the coil 48a and the end part of the coil 48b 114 are connected to the common node 115. [

Specific examples of the high side switch portions 91, 92, and 93 and the low side switch portions 94, 95, and 96 include N-channel type or npn type transistors and the like. Specific examples of the transistor include a MOSFET, an IGBT, and a bipolar transistor.

The current sensor 67A is a current detection unit that detects a drive current flowing through the coil 48a of the electromagnet 49A in the current path 117 and outputs detection data Iufb corresponding to the current value of the drive current. The current sensor 67B is a current detection unit that detects a drive current flowing through the coil 48b of the electromagnet 49B in the current path 118 and outputs detection data Ivfb corresponding to the current value of the drive current.

The mold clamping processing unit 62 performs switching operations of the driving units 101, 102, and 103 constituting the driving circuit 90 so that the sizes of the mold clamping forces that can be generated by the electromagnets 49A and 49B can be independently adjusted . The mold shape processing unit 62 includes a current command calculation unit 63, an AD conversion unit 66, a current control unit 64, and a PWM signal generation unit 65, for example.

The current command calculator 63 converts an operation command of the electromagnet 49A received from the outside into a current command value necessary for realizing the contents of the operation command with the electromagnet 49A and outputs the current command value to the electromagnet 49B, To the current command value necessary for realizing the contents of the operation command with the electromagnet 49B.

The AD conversion section 66 converts the detection data Iufb supplied from the current sensor 67A into the current detection value of the drive current of the electromagnet 49A and outputs the detection data Ivfb supplied from the current sensor 67B, Into the current detection value of the drive current of the electromagnet 49B.

The current control unit 64 determines the error of the drive current of the electromagnet 49A based on the error between the current command value supplied from the current command calculation unit 63 and the current detection value supplied from the AD conversion unit 66 The control command value Vuw for converging the control command value Vuw. The control command value Vuw is a voltage command between the current paths 117 and 119 (between the intermediate nodes 97 and 99). Likewise, the current control unit 64, based on the error between the current command value supplied from the current command calculation unit 63 and the current detection value supplied from the AD conversion unit 66 with respect to the drive current of the electromagnet 49B, (Vvw) to converge to zero. The control command value Vvw is a voltage command between the current paths 118 and 119 (between the intermediate nodes 98 and 99).

The PWM signal generating unit 65 generates a PWM signal based on the control command values Vuw and Vvw for the drive currents of the electromagnets 49A and 49B supplied from the current control unit 64, (101, 102, 103). The drive circuit 90 is driven by a drive current of any size and direction through the coil 48a of the electromagnet 49A and the coil 48b of the electromagnet 49B by the drive units 101, The magnitude of the voltage applied to both ends of the coil 48a and the coil 48b and the direction of the polarity can be controlled.

Therefore, according to the present embodiment, since the driving units to be connected to one side of each of the two electromagnets 49A and 49B are common to one driving unit 103, the driving circuit 90 can be downsized. As a result, the control section 60 and the injection molding machine 1 can be downsized.

For example, in order to drive two electromagnets, four transistors and eight transistors are required, but in the configuration of Fig. 5 of this embodiment, three transistors and six transistors can be used.

The voltage Vdc of the smoothing capacitor 82 of the DC link 80 can be independently applied to each of the coils 48a and 48b so that the electromagnet unit 37 having the electromagnets 49A and 49B can be used, It is possible to increase the responsiveness of the system.

Although the preferred embodiments of the present invention have been described in detail, it is to be understood that the present invention is not limited to the above-described embodiments, but may be modified and changed without departing from the scope of the present invention. , Combinations and permutations can be added.

For example, in the embodiment described above, the case of driving two electromagnets is exemplified, but the present invention can also be applied to the case of driving three or more electromagnets. 6, the driving units 121, 122 and 123 are connected to one end of the corresponding one of the three electromagnets 149A, 149B and 149C, and the driving unit 124 is connected to one end of the electromagnets 149A, 149B and 149C And the other end thereof.

3 and 4, a plurality of electromagnets are formed by laminating a plurality of coils in one coil groove. However, one coil may be disposed in each of the plurality of coil grooves A plurality of electromagnets may be formed by arranging a plurality of coils in each of the plurality of coil grooves.

As described above, for example, an electromagnet 49 may be provided on the suction plate 22 side and a suction portion may be provided on the rear platen 13 side. When the electromagnet 49 is provided on the attracting plate 22 side as described above, the above-described coil lamination structure can be realized on the attracting plate 22 side.

Although the injection molding machine 1 and the mold clamping apparatus 10 having a specific configuration are exemplified in the above description, the injection molding machine 1 and the mold clamping apparatus 10 may be any configuration as long as they are molded using an electromagnet do.

However, in the above-described embodiments, the "first fixing member" in the claims corresponds to the fixed platen 11, and the "first movable member" in the claims is the movable platen (12). The "second fixing member" in the claims corresponds to the rear platen 13, and the "second movable member" in the claims corresponds to the suction plate 22. [

Fr frame
Gd Guide
1 Injection molding machine
10-shaped device
11 stationary platen
12 operation platens
13 Rear Platen
14 Tie bars
15 stationary mold
16 Operation mold
17 Injection device
18 Injection nozzle
19 Mold equipment
22 suction plate
28 Linear Motors
29 Stator
31 mover
33 stimulus value
34 cores
35 coils
37 electromagnet unit
39 center rod
41 holes
45 coil home
46 cores
46a center portion
46b intermediate core portion
48, 48a, 48b coils
49, 49A, 49B, 149A, 149B, 149C Electromagnet
51 adsorption part
55 Load detector
60 control unit
61 type opening /
The 62-
74 converter
80 DC link
90 drive circuit
91, 92, 93 High side switch section
94, 95, 96 Low side switch section
97, 98, 99 intermediate nodes
101, 102, 103, 121, 122, 123, 124,

Claims (8)

A plurality of electromagnets for generating a mold clamping force, and a drive device for driving the electromagnets,
The driving device includes:
A first driving part provided for each of the electromagnets and connected to one end of each electromagnet,
And a second driving part connected in common to the other ends of the electromagnets. The method according to claim 1,
Wherein the second driver comprises:
A high side switch portion and a low side switch portion,
And intermediate nodes to which the high side switch unit and the low side switch unit are connected are connected in common to the other ends. The method according to claim 1 or 2,
Wherein the first driving unit includes:
A high side switch portion and a low side switch portion,
And an intermediate node to which said high side switch portion and said low side switch portion are connected is connected to said one end. The method according to any one of claims 1 to 3,
A first fixing member on which the stationary mold is mounted,
A second fixing member disposed to face the first fixing member,
A first movable member mounted with a movable mold,
And a second movable member connected to the first movable member and moving together with the first movable member,
Wherein the second fixing member and the second movable member generate a mold clamping force by an attraction force by the electromagnet. The method of claim 4,
Wherein the electromagnet is disposed on at least one of the second fixed member and the second movable member. The method according to claim 5,
Wherein the coil constituting the electromagnet is disposed in a groove formed in at least one of the second fixing member and the second movable member. The method of claim 6,
Wherein the coil is disposed in a laminated manner in the groove. A driving device for driving a plurality of electromagnets,
A first driving part provided for each of the electromagnets and connected to one end of each electromagnet,
And a second driving unit commonly connected to the other ends of the electromagnets.

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