TW201325868A - Injection molding machine - Google Patents

Abstract

To provide an injection molding machine that enables mounting of a mold apparatus in a state where the current supply to the electromagnet coil under the control of a control device is stopped. The injection molding machine includes a mold clamping force generation mechanism that generates the mold clamping force by the attractive force by the electromagnet 49. The mold clamping force generation mechanism contains a current supply part 100 that supplies the current to the coil 48 of the electromagnet 49, and the control device 60 that controls the current supply part 100. There is provided an electric circuit 200 that supplies the current to the coil 48 in the state where the current supply to the coil 48 by the current supply part 100 under the control by the control device 60 is stopped.

Description

Injection molding machine

The present invention relates to an injection molding machine.

The injection molding machine is formed into a molded article by ejecting molten resin from an injection device, filling it in a cavity of the mold device, and solidifying it. The mold device is composed of a fixed mold and a movable mold. The mold closing, mold clamping, and mold opening of the mold apparatus are performed by a mold clamping device.

As a mold clamping device, a driving source such as a motor and a toggle mechanism are widely used. However, in the characteristics of the toggle mechanism, it is difficult to change the clamping force, and the responsiveness or stability is poor. Further, when the toggle mechanism is operated, a bending moment is generated, and the mounting surface of the mounting die device may be distorted.

For this reason, a mold clamping device that uses an adsorption force of an electromagnet for a mold-locking operation is proposed (for example, see Patent Document 1). In the mold clamping device, a current is supplied to the coil of the electromagnet under the control of the control device.

(previous technical literature) (Patent Literature)

Patent Document 1: International Publication No. 05/090052

The mold device is replaced according to the type of the molded article. When a new mold device is installed, the mold device is temporarily fixed to the mounting surface by bolts, the mold is closed, and the bolt is further tightened in the mold clamping state to be formally fixed. It is also possible to use a hydraulic or magnetic clamping device or the like instead of the bolt.

Since the main fixing operation is performed by opening the door provided on the injection molding machine cover, in order to eliminate the malfunction due to the control device, the supply of current to the mold clamping device is stopped while the door is opened.

In this state, the clamping force generated in advance can be maintained by using the toggle mechanism, but the clamping force cannot be maintained by using an electromagnet. This is because the current supply to the coil of the electromagnet based on the control device is cut off. Therefore, in the method of using an electromagnet, it is difficult to perform a formal fixing operation.

The present invention has been developed in view of the above problems, and an object of the invention is to provide an injection molding machine capable of mounting a mold device while stopping supply of current to a coil of an electromagnet under the control of a control device.

In order to achieve the above object, an injection molding machine according to another aspect of the present invention includes: a first fixing member to which a fixed mold is attached; a first movable member to which a movable mold is attached; and a second movable member to which The first movable member moves together; the second fixed member is disposed between the first movable member and the second movable member; and the clamping force generating mechanism is based on the adsorption force of the electromagnet a clamping force is generated between the fixing member and the second movable member, the clamping force generating means includes a current supply portion for supplying a current to the coil of the electromagnet, and a control device for controlling the current supply portion, wherein the injection molding machine is provided There is an electric circuit that supplies a current to the coil in a state where the current is supplied to the coil by the current supply unit under the control of the control device.

According to the present invention, it is possible to provide an injection molding machine capable of mounting a mold device while stopping the supply of current to the coil of the electromagnet under the control of the control device.

In the following, the embodiments for carrying out the invention will be described with reference to the drawings, and the same or corresponding components will be denoted by the same or corresponding elements in the drawings, and the description will be omitted. In addition, the moving direction of the movable platen when the mold is closed is set to the front, and the moving direction of the movable platen when the mold is opened is set to the rear.

Fig. 1 is a view showing a state in which the injection molding machine according to the embodiment of the present invention is closed. Fig. 2 is a view showing a state at the time of mold opening of the injection molding machine according to the embodiment of the present invention. Fig. 3 is a view showing a circuit for supplying a current to a coil of an electromagnet in an injection molding machine according to an embodiment of the present invention.

In the figure, 10 is a clamping device, and Fr is a frame of the injection molding machine. Gd is a guide composed of two rails laid on the frame Fr, and 11 is a fixed platen (first fixing member). The fixed platen 11 can be disposed on the bottom plate Ba that is positionally movable along the guide member Gd that extends in the mold opening and closing direction (the horizontal direction in the drawing). In addition, the fixed platen 11 can also be placed on the frame Fr.

A movable platen (first movable member) 12 is disposed opposite to the fixed platen 11. The movable platen 12 is fixed to the movable bottom plate Bb, and the movable bottom plate Bb can advance on the guide Gd. Thereby, the movable platen 12 can be moved in the mold opening and closing direction with respect to the fixed platen 11.

A rear platen (second fixing member) 13 is disposed in parallel with the fixed platen 11 at a predetermined interval from the fixed platen 11. The rear platen 13 is fixed to the frame Fr via the leg portion 13a.

Four connecting rods 14 (only two of the four connecting rods 14 are shown in the drawing) are bridged between the fixed platen 11 and the rear platen 13. The fixed platen 11 is fixed to the rear platen 13 via a connecting rod 14. The movable platen 12 is disposed to be retractable along the connecting rod 14. A guide hole (not shown) through which the connecting rod 14 is inserted is formed in a portion of the movable platen 12 corresponding to the connecting rod 14. In addition, a notch portion may be formed instead of the guide hole.

A screw portion (not shown) is formed at a distal end portion (right end portion in the drawing) of the connecting rod 14, and the distal end portion of the connecting rod 14 is fixed to the fixed platen 11 by screwing the nut n1 to the screw portion. . The rear end portion of the connecting rod 14 is fixed to the rear pressure plate 13.

The fixed mold 15 and the movable mold 16 are respectively mounted on the fixed pressing plate 11 and the movable pressing plate 12, and the fixed mold 15 and the movable mold 16 are accompanied by the movable pressing plate 12 The advancement and retreat are contact and separation, thereby performing mold closing, mold clamping and mold opening. Further, as the mold clamping is performed, a cavity space (not shown) is formed between the fixed mold 15 and the movable mold 16, and molten resin (not shown) which is emitted from the injection nozzle 18 of the injection device 17 is filled in the cavity space. The mold device 19 is constituted by the fixed mold 15 and the movable mold 16.

The suction plate 22 (second movable member) is disposed in parallel with the movable platen 12. The suction plate 22 is fixed to the slide bottom plate Sb via a mounting plate 27, and the slide bottom plate Sb can travel on the guide Gd. Thereby, the suction plate 22 can move forward and backward more than the rear pressure plate 13. The adsorption plate 22 can also be formed by a magnetic material. Alternatively, the mounting plate 27 may be omitted. At this time, the suction plate 22 is directly fixed to the sliding bottom plate Sb.

The rod 39 is disposed to be coupled to the suction plate 22 at the rear end portion and coupled to the movable platen 12 at the front end portion. Therefore, the rod 39 advances with the advancement of the suction plate 22 at the time of mold closing, and advances the movable platen 12, and retreats with the retraction of the suction plate 22 at the time of mold opening, and the movable platen 12 is retracted. Therefore, a hole 41 through which the rod 39 is inserted is formed in the central portion of the rear platen 13.

The linear motor 28 is a mold opening and closing drive unit for moving the movable platen 12 forward and backward, and is disposed between, for example, the suction plate 22 and the frame Fr that are coupled to the movable platen 12. Further, the linear motor 28 may be disposed between the movable platen 12 and the frame Fr.

The linear motor 28 includes a stator 29 and a movable member 31. The stator 29 is formed to be parallel to the guide Gd on the frame Fr and to correspond to the range of movement of the slide base Sb. The movable member 31 is at the lower end of the sliding bottom plate Sb and the stator 29 is formed and is formed over a predetermined range.

The movable member 31 is provided with a core material 34 and a coil 35. Further, the core member 34 includes a plurality of magnetic pole teeth 33 that protrude toward the stator 29 and are formed at a predetermined pitch, and the coils 35 are wound around the respective magnetic pole teeth 33. Further, the magnetic pole teeth 33 are formed to be parallel to each other in a direction perpendicular to the moving direction of the movable platen 12. Further, the stator 29 includes a core material (not shown) and a permanent magnet (not shown) formed by extending the core material. The permanent magnet is formed by alternately magnetizing the magnetic poles of the N pole and the S pole. A position sensor 75 that detects the position of the movable member 31 is disposed.

When the linear motor 28 is driven by supplying a predetermined current to the coil 35, the movable member 31 advances and retracts. As a result, the suction plate 22 and the movable platen 12 advance and retreat, thereby enabling mold closing and mold opening. The linear motor 28 is feedback-controlled in accordance with the detection result of the position sensor 75 so that the position of the movable member 31 becomes a set value.

Further, in the present embodiment, the permanent magnet is disposed on the stator 29, and the coil 35 is disposed on the movable member 31. However, the coil can be disposed on the stator and the permanent magnet can be disposed on the movable member. On the child. At this time, since the coil does not move with the driving of the linear motor 28, the wiring for supplying electric power to the coil can be easily performed.

Further, instead of the linear motor 28, a rotary motor and a ball screw mechanism that converts the rotational motion of the rotary motor into a linear motion may be used as the mold opening and closing drive unit.

The electromagnet unit 37 generates a clamping force between the rear platen 13 and the suction plate 22 by the adsorption force based on the electromagnet. The adsorption force is transmitted via the rod 39 It is delivered to the movable platen 12.

Further, the mold clamping device 10 is constituted by the fixed platen 11, the movable platen 12, the rear platen 13, the suction plate 22, the linear motor 28, the electromagnet unit 37, the rod 39, and the like. Further, the electromagnet unit 37 or the like constitutes a mold clamping force generating mechanism. The clamping force generating mechanism includes a current supply unit 100 that supplies a current to the coil 48 of the electromagnet 49 (see FIG. 3) and a control device 60 that controls the current supply unit 100.

The electromagnet unit 37 is composed of an electromagnet 49 formed on the side of the rear platen 13 and an adsorption portion 51 formed on the side of the adsorption plate 22. The adsorption portion 51 is formed at a predetermined portion of the front end surface of the adsorption plate 22, for example, a portion of the adsorption plate 22 that surrounds the rod 39 and faces the electromagnet 49. Further, at a predetermined portion of the rear end surface of the rear platen 13, for example, a groove 45 is formed around the rod 39, a coil 46 is formed inside the groove 45, and a yoke 47 is formed outside the groove 45. And in the groove 45, the coil 48 is wound around the core material 46.

Further, in the present embodiment, the electromagnet 49 is formed separately from the rear platen 13, and the adsorption portion 51 is formed separately from the adsorption plate 22. However, an electromagnet may be formed as a part of the rear platen 13, and an adsorption portion may be formed as a part of the adsorption plate 22. Further, the electromagnet and the adsorption portion may be arranged in reverse. For example, the electromagnet 49 can be provided on the side of the adsorption plate 22, and the adsorption portion 51 can be provided on the side of the rear platen 13.

In the electromagnet unit 37, when a current is supplied to the coil 48, the electromagnet 49 is driven to adsorb the adsorption portion 51, and a clamping force can be generated.

The drive of the linear motor 28 and the electromagnet 49 of the mold clamping device 10 is controlled by the control device 60. The control device 60 includes a CPU, a memory, and the like. The current is supplied to the coil 35 of the linear motor 28 or the coil 48 of the electromagnet 49 as a result of the CPU calculation. A load detector 55 is connected to the control unit 60. The load detector 55 is disposed at a predetermined position (predetermined position between the fixed platen 11 and the rear platen 13) of at least one of the connecting rods 14 in the mold clamping device 10, and detects the load applied to the connecting rod 14. The load detector 55 includes, for example, a sensor that detects the amount of elongation of the connecting rod 14. The load detected by the load detector 55 is transmitted to the control device 60.

As shown in FIG. 3, the control device 60 is connected to a current supply unit (driver) 100 that supplies a current to the coil 48 of the electromagnet 49 to control the current supply unit 100. The current supply unit 100 is controlled by a mode locking processing unit 62 which will be described later.

The current supply unit 100 is connected to a DC power source (for example, a charger) PW, and supplies a current of a current value corresponding to a control signal from the control device 60 to the coil 48 of the electromagnet 49. The current supply unit 100 includes, for example, a power module or the like.

The current supply unit 100 may include an opening/closing monitoring switch (not shown) that is in an ON state in which current is allowed to be supplied to the coil 48 of the electromagnet 49 only when the door provided on the cover of the injection molding machine is closed. When the opening/closing monitoring switch is turned off, the current supply to the coil 48 of the electromagnet 49 by the current supply unit 100 is cut off.

Further, the opening and closing monitoring switch may be connected to the control device 60 and not included in the current supply unit 100. At this time, when the state of the opening and closing monitoring switch is turned off, the control device 60 cuts off the current supply to the coil 48 of the electromagnet 49 by the current supply unit 100.

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

The mold closing process is controlled by the mold opening and closing processing unit 61 of the control device 60. In the state (opening state) of Fig. 2, the mold opening and closing processing unit 61 supplies a current to the coil 35 to drive the linear motor 28. As shown in Fig. 1, the movable platen 12 advances and the movable die 16 abuts against the fixed die 15. At this time, a gap δ is formed between the rear platen 13 and the adsorption plate 22, that is, between the electromagnet 49 and the adsorption portion 51. In addition, the force required to close the mold is very small compared to the clamping force.

Next, the mold clamping processing unit 62 of the control device 60 controls the mold clamping process. The mold clamping processing unit 62 supplies a current to the coil 48 of the electromagnet 49, and adsorbs the adsorption unit 51 to the electromagnet 49. Accordingly, the clamping force is transmitted to the movable platen 12 via the suction plate 22 and the rod 39, thereby performing mold clamping.

The clamping force is detected by the load detector 55. The detected clamping force is sent to the control device 60, and the mode locking processing unit 62 controls the current supply unit 100 so that the clamping force becomes a set value, and the current supplied to the coil 48 is adjusted, and feedback control is performed. During this period, the molten resin melted in the injection device 17 is emitted from the injection nozzle 18 and filled in the cavity space of the mold device 19.

When the resin in the cavity space is cooled and solidified, the die opening and closing processing portion 61 controls the mold opening process. In the state of Fig. 1, the mold clamping processing unit 62 stops supplying current to the coil 48 of the electromagnet 49. Accordingly, the linear motor 28 is driven, and the movable platen 12 is retracted. As shown in Fig. 2, the movable mold 16 is retracted to perform mold opening.

Next, the mold thickness adjustment when the mold device 19 is replaced will be described.

When the new mold clamping device 19 is mounted as the mold changing device 19 is replaced, the thickness of the mold device 19 is changed, and the gap δ formed between the rear pressure plate 13 and the suction plate 22 at the end of the mold closing is changed.

Therefore, the injection molding machine includes the mold thickness adjusting device 70 that adjusts the gap δ in accordance with the thickness of the mold device 19. The mold thickness adjusting device 70 includes a mold thickness adjusting motor 71, a gear 72, a nut 73, a rod 39, and the like. The rod 39 penetrates the central portion of the suction plate 22, and the thread 43 is formed at the rear end portion of the rod 39. The thread 43 is screwed to the nut 73 that is rotatably supported by the suction plate 22. The outer peripheral surface of the nut 73 is formed with a large-diameter gear (not shown) that meshes with the small-diameter gear 72 attached to the output shaft 71a of the mold thickness adjusting motor 71. The nut 73 and the thread 43 constitute a movement direction changing portion in which the rotational motion of the nut 73 is converted into the linear motion of the rod 39.

When the movable mold thickness adjusting motor 71 is driven in accordance with the thickness of the mold device 19 and the nut 73 is rotated by a predetermined amount with respect to the screw 43, the position of the rod 39 with respect to the suction plate 22 is adjusted, and the suction plate 22 is opposed to the fixed platen. The position of the movable platen 12 and the movable platen 12 are adjusted so that the gap δ can be optimized. That is, the mold thickness is adjusted by changing the distance between the movable platen 12 and the suction plate 22 in the mold opening and closing direction (the horizontal direction in the drawing).

The mold thickness adjustment motor 71 may be a servo motor or may include an encoder portion 71b. The encoding unit 71b detects the amount of rotation or the like of the output shaft 71a of the mold thickness adjustment motor 71, and transmits the detection result to the control device 60. The control device 60 feedback-controls the mold thickness adjusting motor 71 so that the gap δ becomes a set value.

Next, the mounting of the mold device 19 will be described.

When the new mold device 19 is mounted, the mold device 19 is temporarily fixed to the fixed platen 11 by bolts while being suspended by a crane or the like. Thereafter, the movable platen 12 is advanced to come into contact with the mold device 19, and then the mold device 19 is mold-locked. In the mold clamping state, the fixed mold 15 and the movable mold 16 are respectively fixedly fixed to the fixed platen 11 and the movable platen 12 by bolts. It is also possible to use a hydraulic or magnetic clamping device or the like instead of the bolt.

Since the main fixing operation is performed by opening the door provided on the cover of the injection molding machine, the state in which the current is supplied to the coil 48 of the electromagnet 49 by the current supply unit 100 (hereinafter also referred to as "stop state") is stopped. This formal fixing operation is performed. This is to eliminate the erroneous actuation based on the control device 60.

The stop state is a servo-off state in which the drive control that is feedback-controlled (for example, the electromagnet 49, the linear motor 28, and the mold thickness adjustment motor 71) is automatically stopped according to the detection result of the various detectors.

The injection molding machine of the present embodiment includes an electric circuit 200 that supplies a current to the coil 48 of the electromagnet 49 in a stopped state.

As shown in FIG. 3, the electric circuit 200 is connected to the coil 48 of the electromagnet 49 and a DC power source (for example, a charger) PW, and supplies current to the electromagnet 49 independently of the current supply unit 100. Unlike the current supply unit 100, the electric circuit 200 is not connected to the control device 60 and is not controlled by the control device 60.

The electric current is supplied to the coil 48 of the electromagnet 49 by the electric circuit 200, Thereby, the electromagnet 49 adsorbs the adsorption portion 51. Accordingly, the clamping force is transmitted to the movable platen 12 via the suction plate 22 and the rod 39, thereby performing mold clamping. Thereby, the mold clamping force can be generated in the stopped state, and the mold fixing operation can be performed.

The electric circuit 200 is constituted by, for example, a manual switch 202, a gap monitoring switch 204, a variable resistor 206, and the like. When both the manual switch 202 and the gap monitoring switch 204 are in an ON state in which current is supplied to the coil 48, a current corresponding to the resistance value of the variable resistor 206 is supplied to the coil 48 of the electromagnet 49, and the electromagnet 49 The adsorption unit 51 is adsorbed.

The manual switch 202 is a switch for manually switching the ON state and the OFF state in which the current is supplied to the coil 48 of the electromagnet 49. The current supply based on the electric circuit 200 can be started and ended according to the user's idea.

Gap monitor switch 204 only formed in the gap between the electromagnet 49 and the attraction portion 51 δ δ 0 is a predetermined value or less is supplied to an allowable current of the ON state, and when the gap exceeds a predetermined value δ 0 [delta], the inhibited The off state of the supply current. Since the current supply by the electric circuit 200 is allowed only when the gap δ is equal to or smaller than the predetermined value δ 0 , when the electromagnet 49 adsorbs the adsorption portion 51 , the adsorption plate 22 , the movable platen 12 , the movable mold 16 , and the like can be restricted from advancing. The predetermined value δ 0 is set, for example, in the range of 1.0 mm to 1.5 mm.

The gap monitoring switch 204 may be an operation switch provided on the side of the rear platen 13 and operated by an operation piece provided on the side of the adsorption plate 22. Moreover, the gap monitoring switch 204 can also be switched to operate according to the operation switch. Electromagnetic contactors, etc., in an on state and an off state.

Further, the operation switch and the operation piece may be disposed oppositely, and the operation switch may be disposed on the suction plate 22 side and the operation piece may be disposed on the rear pressure plate 13 side. Also, a non-contact proximity switch can be used instead of the operation switch.

The variable resistor 206 sets the current value of the current supplied to the coil 48 of the electromagnet 49 to be variable, and manually changes the resistance value. The lower the resistance value, the higher the current value, and the stronger the adsorption force of the electromagnet 49. Thereby, the clamping force can be adjusted using the variable resistor 206.

Next, a mounting method (official fixing operation) of the mold device 19 using the injection molding machine having the above configuration will be described.

First, after the temporary fixing operation, the linear motor 28 is driven to bring the movable platen 12 into contact with the movable die 16. At this time, the gap δ (>0) formed between the electromagnet 49 and the adsorption unit 51 is equal to or lower than a predetermined value δ 0 , and the gap monitoring switch 204 is turned on. The distance between the suction plate 22 and the movable platen 11 may be adjusted by the mold thickness adjusting device 70 after or before the linear motor 28 is driven so that the gap δ becomes a predetermined value δ 0 or less.

Next, when the door of the injection molding machine is opened, the injection molding machine is stopped, and the current supply to the coil 48 of the electromagnet 49 by the current supply unit 100 is cut off.

Next, a current is supplied to the coil 48 of the electromagnet 49 by the electric circuit 200. First, the manual switch 202 is set to the ON state, and then the resistance value of the variable resistor 206 is gradually decreased, and the current value flowing to the coil 48 is gradually increased to the set value. Thereby, the electromagnet 49 adsorbs the adsorption portion 51, and the clamping force is transmitted to the movable platen 12 via the adsorption plate 22 and the rod 39. , thus performing mode locking. Therefore, the formal fixing operation can be performed in the mold clamping state.

The embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications or substitutions may be made to the above embodiment without departing from the scope of the invention.

For example, the electric circuit 200 of the above-described embodiment may include a switch that allows current to be supplied to the coil 48 of the electromagnet 49 when the injection molding machine is in a stopped state, and prohibits supply of current to the coil 48 when the stop state is released. Thereby, it is possible to prevent both the electric circuit 200 and the current supply unit 100 from simultaneously supplying current to the coil 48 of the electromagnet 49.

10‧‧‧Clamping device

11‧‧‧Fixed platen (1st fixing member)

12‧‧‧ movable platen (1st movable member)

13‧‧‧ Rear platen (2nd fixing member)

15‧‧‧Fixed mode

16‧‧‧ movable mold

22‧‧‧Adsorption plate (2nd movable member)

37‧‧‧Electromagnetic unit (clamping force generation mechanism)

48‧‧‧ coil

49‧‧‧Electromagnet

60‧‧‧Control device

100‧‧‧ Current Supply Department

200‧‧‧Electrical circuit

204‧‧‧Gap monitoring switch

206‧‧‧Variable resistor

Fig. 1 is a view showing a state in which the injection molding machine according to the embodiment of the present invention is closed.

Fig. 2 is a view showing a state at the time of mold opening of the injection molding machine according to the embodiment of the present invention.

Fig. 3 is a view showing a circuit for supplying a current to an electromagnet in an injection molding machine according to an embodiment of the present invention.

48‧‧‧ coil

60‧‧‧Control device

100‧‧‧ Current Control Department

200‧‧‧Electrical circuit

202‧‧‧Manual switch

204‧‧‧Gap monitoring switch

206‧‧‧Variable Resistor

PW‧‧‧DC power supply

Claims (3)

An injection molding machine comprising: a first fixing member to which a fixed mold is attached; a first movable member to which a movable mold is attached; a second movable member that moves together with the first movable member; and a second fixed member a member disposed between the first movable member and the second movable member; and a clamping force generating mechanism between the second fixed member and the second movable member by an adsorption force of the electromagnet Generating a clamping force, the clamping force generating mechanism includes a current supply unit that supplies a current to the coil of the electromagnet, and a control device that controls the current supply unit, wherein the injection molding machine is provided with an electric circuit that is stopped based on the control device Under the control, the current is supplied to the coil in a state where the current is supplied to the coil. The injection molding machine according to claim 1, wherein the electric circuit includes a variable resistor that changes a current value of a current supplied to the coil. The injection molding machine according to the first or second aspect of the invention, wherein the electric circuit includes a switch, wherein a gap formed between the electromagnet and the adsorption portion adsorbed to the electromagnet is a predetermined value or less It is allowed to supply a current to the coil, and when the gap exceeds a predetermined value, supply of current to the coil is prohibited.