JP5897933B2 - Injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine.

  An injection molding machine manufactures a molded product by filling molten resin into a cavity space of a mold apparatus and solidifying the resin. The mold apparatus includes a fixed mold and a movable mold, and a cavity space is formed between the fixed mold and the movable mold when the mold is clamped. Mold closing, mold clamping, and mold opening of the mold apparatus are performed by a mold clamping apparatus. As a mold clamping device, an apparatus using a linear motor for mold opening / closing operation and an electromagnet for mold clamping operation has been proposed (for example, see Patent Document 1).

WO05 / 090052 pamphlet

  Conventionally, reduction of power consumption of a linear motor has been demanded. Linear motors tend to consume more power during acceleration and deceleration than during constant speed travel.

  The present invention has been made in view of the above problems, and an object thereof is to provide an injection molding machine capable of reducing power consumption of a linear motor.

In order to solve the above problems, an injection molding machine according to an aspect of the present invention is provided.
A stationary platen to which a stationary mold is attached;
A movable platen to which a movable mold is attached;
A movable member that moves with the movable platen;
A fixed member disposed between the movable platen and the movable member;
A rod penetrating the fixed member and connecting the movable platen and the movable member;
The movable platen, the movable member that moves together with the movable member and the rod, and a stator that includes a linear motor that performs mold opening and closing operations.
The movable member and the fixed member constitute a mechanism for generating a clamping force by an attractive force of an electromagnet,
A plurality of elastic bodies that are elastically deformed by the attraction force of the electromagnet are disposed symmetrically about the rod ,
When the attraction force of the electromagnet is released, the mover is accelerated in the mold opening direction by the elastic restoring force of the plurality of elastic bodies .

  ADVANTAGE OF THE INVENTION According to this invention, the injection molding machine which can reduce the power consumption of a linear motor is provided.

It is a figure which shows the state at the time of mold closing completion of the injection molding machine by 1st Embodiment of this invention. It is a figure which shows the state at the time of the mold opening completion of the injection molding machine by 1st Embodiment of this invention. It is explanatory drawing of the deceleration mechanism of the injection molding machine by 1st Embodiment. It is explanatory drawing of the deceleration mechanism of the injection molding machine by 2nd Embodiment. It is explanatory drawing of the deceleration mechanism of the injection molding machine by 3rd Embodiment. It is explanatory drawing of the acceleration mechanism of the injection molding machine by 4th Embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each of the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and description thereof will be omitted. Further, a description will be given assuming that the moving direction of the movable platen when performing mold closing is the front and the moving direction of the movable platen when performing mold opening is the rear.

[First Embodiment]
FIG. 1 is a view showing a state at the completion of mold closing of the injection molding machine according to the first embodiment of the present invention. FIG. 2 is a view showing a state when the mold opening of the injection molding machine according to the first embodiment of the present invention is completed.

  In the figure, 10 is an injection molding machine, Fr is a frame of the injection molding machine 10, Gd is a guide composed of two rails laid on the frame Fr, and 11 is a fixed platen. The fixed platen 11 may be provided on a position adjustment base Ba that is movable along a guide Gd that extends in the mold opening / closing direction (left-right direction in the drawing). The fixed platen 11 may be placed on the frame Fr.

  A movable platen 12 is disposed facing the fixed platen 11. The movable platen 12 is fixed on the movable base Bb, and the movable base Bb can run on the guide Gd. Thereby, the movable platen 12 is movable in the mold opening / closing direction with respect to the fixed platen 11.

  A rear platen 13 is disposed in parallel to 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.

  Between the fixed platen 11 and the rear platen 13, four tie bars 14 (only two of the four tie bars 14 are shown in the figure) are installed as connecting members. The fixed platen 11 is fixed to the rear platen 13 via the tie bar 14. A movable platen 12 is disposed along the tie bar 14 so as to freely advance and retract. A guide hole (not shown) for penetrating the tie bar 14 is formed at a position corresponding to the tie bar 14 in the movable platen 12. In addition, you may make it form a notch part instead of a guide hole.

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

  A fixed mold 15 is attached to the fixed platen 11, and a movable mold 16 is attached to the movable platen 12. The fixed mold 15 and the movable mold 16 are brought into contact with and separated from each other as the movable platen 12 advances and retreats. Closing, mold clamping and mold opening are performed. As the mold clamping is performed, a cavity space (not shown) is formed between the fixed mold 15 and the movable mold 16, and the cavity space is filled with molten resin. A mold apparatus 19 is configured by the fixed mold 15 and the movable mold 16.

  The suction plate 22 is disposed in parallel with the movable platen 12. The suction plate 22 is fixed to the slide base Sb via the mounting plate 27, and the slide base Sb can travel on the guide Gd. As a result, the suction plate 22 can move back and forth behind the rear platen 13. The adsorption plate 22 may be formed of a soft magnetic material. The attachment plate 27 may not be provided, and in this case, the suction plate 22 is directly fixed to the slide base Sb.

  The rod 39 is connected to the suction plate 22 at the rear end portion and is connected to the movable platen 12 at the front end portion. Therefore, the rod 39 is moved forward as the suction plate 22 moves forward when the mold is closed to move the movable platen 12 forward, and is retracted and moved backward as the suction plate 22 moves back when the mold is opened. Retreat. For this purpose, a rod hole 41 for penetrating the rod 39 is formed in the central portion of the rear platen 13.

  The linear motor 28 is a mold opening / closing drive unit for moving the movable platen 12 forward and backward, and is disposed, for example, between the suction plate 22 connected to the movable platen 12 and the frame Fr. 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 mover 31. The stator 29 is formed on the frame Fr in parallel with the guide Gd and corresponding to the movement range of the slide base Sb. The mover 31 is formed at a lower end of the slide base Sb so as to face the stator 29 and over a predetermined range.

  The mover 31 includes a core 34 and a coil 35. The core 34 includes a plurality of magnetic pole teeth 33 that protrude toward the stator 29. The plurality of magnetic pole teeth 33 are arranged at a predetermined pitch in a direction parallel to the mold opening / closing direction. The coil 35 is wound around each magnetic pole tooth 33.

  The stator 29 includes a core (not shown) and a plurality of permanent magnets (not shown) provided on the core. The plurality of permanent magnets are arranged at a predetermined pitch in a direction parallel to the mold opening / closing direction, and the magnetic poles on the side of the mover 31 are alternately magnetized into N and S poles.

  When a predetermined current is supplied to the coil 35 of the mover 31, the mover 31 is advanced and retracted by the interaction between the magnetic field formed by the current flowing through the coil 35 and the magnetic field formed by the permanent magnet. Accordingly, the suction plate 22 and the movable platen 12 are moved back and forth, and the mold closing and mold opening are performed. The linear motor 28 is feedback-controlled based on the detection result of the position sensor 53 that detects the position of the mover 31 so that the position of the mover 31 becomes a target value.

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

  The electromagnet unit 37 generates an attracting force between the rear platen 13 and the attracting plate 22. This suction force is transmitted to the movable platen 12 via the rod 39, and a mold clamping force is generated between the movable platen 12 and the fixed platen 11.

  The electromagnet unit 37 includes an electromagnet 49 formed on the rear platen 13 side and a suction portion 51 formed on the suction plate 22 side. The suction portion 51 is formed in a predetermined portion of the suction surface (front end surface) of the suction plate 22, for example, a portion surrounding the rod 39 in the suction plate 22 and facing the electromagnet 49. A groove 45 for accommodating the coil 48 of the electromagnet 49 is formed around a predetermined portion of the attracting surface (rear end surface) of the rear platen 13, for example, around the rod 39. A core 46 is formed inside the groove 45. A coil 48 is wound around the core 46. A yoke 47 is formed at a portion other than the core 46 of the rear platen 13.

  In the present embodiment, the electromagnet 49 is formed separately from the rear platen 13 and the attracting part 51 is formed separately from the attracting plate 22, but the electromagnet is part of the rear platen 13 and the attracting part is part of the attracting plate 22. May be formed. Moreover, the arrangement of the electromagnet and the attracting part may be reversed. For example, the electromagnet 49 may be provided on the suction plate 22 side, and the suction portion 51 may be provided on the rear platen 13 side. Moreover, the number of the coils 48 of the electromagnet 49 may be plural.

  When an electric current is supplied to the coil 48 in the electromagnet unit 37, the electromagnet 49 is driven to attract the attracting part 51 and generate a mold clamping force. The electromagnet unit 37 is feedback-controlled so that the mold clamping force becomes a target value based on the detection result of the mold clamping force sensor 55 that detects the mold clamping force. The mold clamping force sensor 55 may be, for example, a strain sensor that detects distortion (elongation amount) of the tie bar 14 that expands according to the mold clamping force. As the mold clamping force sensor 55, for example, a load sensor such as a load cell that detects a load applied to the rod 39 or a magnetic sensor that detects the magnetic field of the electromagnet 49 can be used. It may be.

  The control unit 60 includes, for example, a CPU and a memory, and controls operations of the linear motor 28 and the electromagnet 49 by processing a control program recorded in the memory by the CPU.

  Next, the operation of the injection molding machine 10 configured as described above will be described. Various operations of the injection molding machine 10 are performed under the control of the control unit 60.

  The controller 60 controls the mold closing process. When the control unit 60 supplies a predetermined current to the coil 35 of the linear motor 28 in the state of FIG. 2 (when the mold opening is completed), the mover 31 starts to move forward from the retracted limit position. The mover 31 is accelerated to the set speed, then moves forward at the set speed, is then decelerated, and stops at the forward limit position. At this time, the fixed mold 15 and the movable mold 16 come into contact with each other, and the mold closing process is completed. At this time, a gap δ is formed between the rear platen 13 and the suction plate 22, that is, between the electromagnet 49 and the suction portion 51. Note that the force required for mold closing is sufficiently reduced compared to the mold clamping force.

  Subsequently, the control unit 60 controls the mold clamping process. The controller 60 supplies a direct current to the coil 48 of the electromagnet 49 in the state shown in FIG. 1 (the state when the mold closing is completed). If it does so, a magnetic field will arise in the coil 48 with the direct current which flows through the coil 48, the core 46 will be magnetized, and a magnetic field will be strengthened. Then, an attracting force is generated between the electromagnet 49 and the attracting part 51 facing each other with a predetermined gap, and this attracting force is transmitted to the movable platen 12 via the rod 39, and the movable platen 12 and the fixed platen 11 are Clamping force is generated between them. The cavity space of the mold apparatus 19 in the mold-clamped state is filled with molten resin, cooled and solidified to form a molded product.

  Next, the control unit 60 controls the mold opening process after stopping the power supply to the coil 48 of the electromagnet 49. When the control unit 60 supplies a predetermined current to the coil 35 of the linear motor 28, the movable platen 12 starts to move backward from the forward limit position. After the movable element 31 is accelerated to the set speed, the mover 31 moves backward at the set speed, then decelerates, stops at the retreat limit position, and the mold opening process is completed. After completion of the mold opening process, the molded product is ejected from the movable mold 16 by an ejector device (not shown), and the molded product is obtained.

  FIG. 3 is an explanatory diagram of the speed reduction mechanism of the injection molding machine according to the first embodiment. FIG. 3A shows a state in which the mover moving in the mold opening direction is traveling at a constant speed, and FIG. 3B shows a state in which the mover is decelerated.

  In order to reduce the power consumption of the linear motor 28, the injection molding machine 10 absorbs at least a part of the kinetic energy of the mover 31 that is moving in the mold opening direction (left direction in the figure) and decelerates the mover 31. A reduction mechanism 70 is provided. For example, as shown in FIG. 3, the speed reduction mechanism 70 includes a spring 71 as an elastic body.

  The deceleration mechanism 70 not only moves the movable element 31 but also moves with the movable element 31 (for example, the slide base Sb, the suction plate 22, the rod 39, the movable platen 12, and the like) when decelerating the movable element 31. The kinetic energy of the movable mold 16) may also be absorbed.

  The spring 71 is, for example, a coil spring, and the expansion / contraction direction of the spring 71 is parallel to the mold opening / closing direction. The spring 71 is disposed between a slide base Sb as a first movable member that moves together with the mover 31 and a fixed member 77, and either one of the slide base Sb and the fixed member 77 (in FIG. 3, the fixed member). 77) only. The fixing member 77 is provided behind the slide base Sb and is fixed to the frame Fr.

  When a predetermined current is supplied to the coil 35 of the linear motor 28 in the state where the mold clamping process is completed, the mover 31 starts moving from the forward limit position toward the rear, and mold opening is started. The mover 31 is accelerated to the set speed and then moves backward at the set speed. At this time, as shown in FIG. 3A, the slide base Sb is not in contact with the spring 71, and the spring 71 is in a natural state and is not elastically deformed.

  Subsequently, when the slide base Sb comes into contact with the spring 71, the spring 71 is sandwiched between the slide base Sb and the fixing member 77 as shown in FIG. Then, at least a part of the kinetic energy of the slide base Sb and the movable element 31 is converted into the elastic energy of the spring 71, and the slide base Sb and the movable element 31 are decelerated. Therefore, the current flowing through the coil 35 of the linear motor 28 for the deceleration of the mover 31 can be reduced. While the mover 31 is decelerated, the energization to the coil 35 of the linear motor 28 may be cut off.

  Thereafter, the mover 31 stops at the retreat limit position, and the mold opening process is completed. At this time, the spring 71 is in the most contracted state, and the elastic restoring force of the spring 71 is the highest. Due to the elastic restoring force of the spring 71, the slide base Sb, the movable element 31, and the movable mold 16 are urged in the mold closing direction (right direction in the figure).

  After the mold opening process is completed, the control unit 60 stops the movable element 31 by supplying current to the coil 35 of the linear motor 28 in order to stop the movable mold 16 while ejecting the molded product from the movable mold 16 by the ejector device. Let The time for stopping the mover 31 is short, and the mold closing process is started immediately after the molded product protrudes.

  At the start of the mold closing process, the mover 31 is accelerated in the mold closing direction by the elastic restoring force of the spring 71. Therefore, the current flowing through the coil 35 of the linear motor 28 for accelerating the mover 31 can be reduced. Until the length of the spring 71 returns to the natural length, the energization to the coil 35 of the linear motor 28 may be cut off.

  As described above, according to the present embodiment, when the mover 31 is turned back at the retreat limit position, the mover 31 is decelerated and accelerated by the reduction mechanism 70, so that the power consumption of the linear motor 28 can be reduced. Here, the electrical energy that can be reduced by the speed reduction mechanism 70 is sufficiently larger than the electrical energy required to stop the mover 31, and a total power saving is possible. The spring constant of the spring 71 is optimized so as to increase the power saving efficiency.

  Since the spring 71 is attached to only one of the fixed member 77 and the slide base Sb, the spring 71 is elastically deformed to decelerate the mover 31 only when the mover 31 is in the vicinity of the retreat limit position. ,To accelerate. Therefore, the constant speed travel of the mover 31 is stabilized.

  In this embodiment, the slide base Sb is used as the first movable member. However, for example, the suction plate 22 or the movable platen 12 may be used.

  Further, the spring of this embodiment is disposed between the first movable member and the fixed member 77, but may be disposed between the movable element 31 and the fixed member 77.

  In this embodiment, a coil spring is used as the spring 71, but an air spring may be used, and the configuration of the spring is not particularly limited. Further, instead of the spring 71, rubber may be used as an elastic body.

[Second Embodiment]
The spring 71 of the first embodiment is disposed between the movable element 31 or the first movable member that moves together with the movable element 31 and the fixed member 77, and is attached to only one of them.

  On the other hand, the spring of this embodiment is different in that it is arranged between the second movable member that moves together with the movable mold 16 and the movable element 31 and connects the two. Hereinafter, the difference will be mainly described.

  FIG. 4 is an explanatory diagram of the speed reduction mechanism of the injection molding machine according to the second embodiment. 4A shows a state when the mold opening is completed, and FIG. 4B shows a state when the mover is decelerated after the mold opening is completed.

  The reduction mechanism 170 absorbs at least a part of the kinetic energy of the mover 31 that is moving in the mold opening direction (left direction in the drawing), and decelerates the mover 31. The speed reduction mechanism 170 includes a spring 171 and the like.

  The spring 171 is, for example, a coil spring, and the expansion / contraction direction of the spring 171 is parallel to the mold opening / closing direction. The spring 171 is arranged between a slide base Sb as a second movable member that moves together with the movable mold 16 and a movable element 31 disposed in front of the slide base Sb. The slide base Sb and the movable element 31 are provided. And A stopper 177 that defines the retreat limit position of the slide base Sb is provided behind the slide base Sb and is fixed to the frame Fr.

  When a predetermined current is supplied to the coil 35 of the linear motor 28 in the state where the mold clamping process is completed, and the movable element 31 starts to move backward from the forward limit position, the spring 171 is moved between the movable element 31 and the slide base Sb. It is pinched and elastically shrinks. In this state, when the mover 31 is further moved rearward, the slide base Sb moves backward and mold opening is started.

  The mover 31 is accelerated to the set speed and then moves backward at the set speed. Thereafter, when the slide base Sb comes into contact with the rear stopper 177, as shown in FIG. 4A, the movable mold 16 stops and the mold opening process is completed.

  After the mold opening process is completed, as shown in FIG. 4B, the spring 171 is pressed toward the slide base Sb by the inertial force of the mover 31 and further contracts. At least a part of the kinetic energy of the mover 31 is converted into elastic energy of the spring 171, and the mover 31 is decelerated. Therefore, the current flowing through the coil 35 of the linear motor 28 for the deceleration of the mover 31 can be reduced. While the mover 31 decelerates, the energization to the coil 35 of the linear motor 28 may be cut off.

  When the deceleration of the mover 31 is completed, the spring 171 is in the most contracted state, and the elastic restoring force of the spring 171 is the highest. Due to the elastic restoring force of the spring 171, the mover 31 is biased in the mold closing direction (right direction in the figure).

  Subsequently, the mover 31 is accelerated in the mold closing direction by the elastic restoring force of the spring 171. Therefore, the current flowing through the coil 35 of the linear motor 28 for accelerating the mover 31 can be reduced. The energization of the coil 35 of the linear motor 28 may be cut off until the length of the spring 171 returns to the natural length.

  When the mover 31 further advances, the slide base Sb moves away from the stopper 177 and the mold closing process is started. Between the completion of the mold opening process and the start of the mold closing process, the molded product is taken out from the stopped movable mold 16.

  In the present embodiment, similarly to the first embodiment, when the movable element 31 is turned back at the retreat limit position, the deceleration and acceleration of the movable element 31 are performed by the deceleration mechanism 170, so that the power consumption of the linear motor 28 is reduced. it can.

  In the present embodiment, unlike the first embodiment, there is time for the slide base Sb and the movable mold 16 to stop while the mover 31 is decelerated or accelerated, during which the molded product protrudes from the movable mold 16. It can be performed. Therefore, it is not necessary to energize the coil 35 of the linear motor 28 for stopping the movable mold 16.

  In this embodiment, the slide base Sb is used as the second movable member, but for example, the suction plate 22 or the movable platen 12 may be used. When the movable platen 12 is used, the movable element 31 is disposed in front of the movable platen 12.

  In the present embodiment, a coil spring is used as the spring 171, but an air spring may be used, and the configuration of the spring is not particularly limited. Further, instead of the spring 171, rubber may be used as an elastic body.

[Third Embodiment]
The speed reduction mechanism 70 of the first embodiment absorbs at least a part of the kinetic energy of the mover 31 moving in the mold opening direction by the spring 71 and decelerates the mover 31.

  On the other hand, the speed reduction mechanism of the present embodiment is different in that at least a part of the kinetic energy is absorbed by the damper and the mover 31 is decelerated. Hereinafter, the difference will be mainly described.

  FIG. 5 is an explanatory view of the speed reduction mechanism of the injection molding machine according to the third embodiment. FIG. 5A shows a state in which the mover moving in the mold opening direction is traveling at a constant speed, and FIG. 5B shows a state in which the mover is decelerated.

  The speed reduction mechanism 270 absorbs at least a part of the kinetic energy of the mover 31 that is moving in the mold opening direction (left direction in the drawing), and decelerates the mover 31. The speed reduction mechanism 270 includes a damper 271 and the like.

  The deceleration mechanism 270 not only moves the mover 31 but also moves with the mover 31 (for example, the slide base Sb, the suction plate 22, the rod 39, the movable platen 12, The kinetic energy of the movable mold 16) may also be absorbed.

  The damper 271 is arranged between a slide base Sb as a third movable member that moves together with the movable element 31 and the fixed member 277, and either one of the slide base Sb and the fixed member 277 (in FIG. 5, the fixed member). 277) only. The fixing member 277 is provided behind the slide base Sb and is fixed to the frame Fr.

The damper 271 includes, for example, a cylinder 272, a piston 273 that can reciprocate within the cylinder 272, and a rod 274 coupled to the piston 273. The internal space of the cylinder 272 is divided into a front chamber 275 and a rear chamber 276 by a piston 273, and each of the front chamber 275 and the rear chamber 276 is filled with a liquid such as oil. The piston 273 is provided with an orifice hole 273a . When the piston 273 is pushed rearward, the liquid in the rear chamber 276 moves to the front chamber 275 through the orifice hole 273a, and the force pushing the piston 273 backward is absorbed by the flow resistance generated at that time. The axial direction of the rod 274 is parallel to the mold opening / closing direction. One end of the damper 271 (for example, the cylinder 272) is attached to the fixing member 277.

  In a state where the mold clamping process is completed, a predetermined current is supplied to the coil 35 of the linear motor 28, the mover 31 starts moving from the forward limit position toward the rear, and mold opening is started. The mover 31 is accelerated to the set speed and then moves backward at the set speed. At this time, as shown in FIG. 5A, the slide base Sb is not in contact with the other end of the damper 271 (for example, the rod 274).

Subsequently, when the slide base Sb comes into contact with the rod 274 and the piston 273 is pushed backward, the liquid in the rear chamber 276 moves to the front chamber 275 through the orifice hole 273a , and heat is generated by the flow resistance generated at that time. Arise. At least a part of the kinetic energy of the slide base Sb and the mover 31 is converted into liquid thermal energy, and the slide base Sb and the mover 31 are decelerated. Therefore, the current flowing through the coil 35 of the linear motor 28 for the deceleration of the mover 31 can be reduced. While the mover 31 is decelerated, the energization to the coil 35 of the linear motor 28 may be cut off.

  Thereafter, the mover 31 stops at the retreat limit position, and the mold opening process is completed. After the mold opening process is completed, the molded product is ejected from the movable mold 16 by the ejector device. While the molded product is projected, the energization to the coil 35 of the linear motor 28 is cut off.

  Next, a predetermined current is supplied to the coil 35 of the linear motor 28, the movable element 31 is accelerated in the mold closing direction, and mold closing is started. Between the start of mold closing and the start of the next mold opening, the position of the piston 273 is returned to the original position.

  In the present embodiment, when the mover 31 is turned back at the retreat limit position, the mover 31 is decelerated by the speed reduction mechanism 270, so that the power consumption of the linear motor 28 is reduced as in the first embodiment. Can do.

  Since the damper 271 is attached to only one of the fixing member 277 and the slide base Sb, the damper 271 decelerates the mover 31 only when the mover 31 is in the vicinity of the retreat limit position. Therefore, the constant speed travel of the mover 31 is stabilized.

  In the present embodiment, the slide base Sb is used as the third movable member, but for example, the suction plate 22 or the movable platen 12 may be used.

  The damper 271 is arranged between the fourth movable member that moves together with the movable mold 16 and the movable element 31 similarly to the spring 171 in the second embodiment, and the fourth movable member and the movable element 31. And may be linked. As the fourth movable member, for example, the slide base Sb, the suction plate 22, or the movable platen 12 may be used.

  In addition, although the damper 271 of this embodiment is an oil damper, an air damper may be sufficient and the structure of the damper 271 is not specifically limited.

[Fourth Embodiment]
The injection molding machine according to the first embodiment includes a speed reduction mechanism that absorbs at least part of the kinetic energy of the mover 31 moving in a predetermined direction by the spring 71 and decelerates the mover 31.

  In contrast, the injection molding machine of the present embodiment includes an acceleration mechanism that accelerates the mover in a predetermined direction by the elastic restoring force of the spring. Hereinafter, the difference will be mainly described.

  FIG. 6 is an explanatory view of an acceleration mechanism of an injection molding machine according to the fourth embodiment. FIG. 6A shows a state during mold clamping, and FIG. 6B shows a state during mold opening.

  The acceleration mechanism 370 includes a spring 371 as an elastic body, and accelerates the mover 31 in the mold opening direction by the elastic restoring force of the spring 371. When accelerating the mover 31, the acceleration mechanism 370 also accelerates members that move with the mover 31 (for example, the slide base Sb, the suction plate 22, the rod 39, the movable platen 12, and the movable mold 16).

  The spring 371 is, for example, a coil spring, and the expansion / contraction direction of the spring 371 is parallel to the mold opening / closing direction. The spring 371 is disposed between the suction plate 22 that moves together with the mover 31 and the rear platen 13, and is attached to only one of the suction plate 22 and the rear platen 13 (the rear platen 13 in FIG. 6).

  A plurality of springs 371 may be arranged around the rod 39 at an equal pitch. For example, as shown in FIG. 6, a pair of upper and lower springs 371 may be provided across the rod 39. Inclination of the suction plate 22 and the rear platen 13 by the elastic restoring force of the spring 371 can be reduced.

  When a predetermined current is supplied to the coil 35 of the linear motor 28 in the mold closing process, the mover 31 starts to move forward from the retreat limit position. The mover 31 is accelerated to the set speed and then advances at the set speed. Thereafter, when the mover 31 is decelerated and stopped, the gap between the suction plate 22 and the rear platen 13 becomes a set value. When the mover 31 stops, (1) the suction plate 22 may be in contact with the spring 371, the spring 371 may be elastically deformed, or (2) the suction plate 22 is not in contact with the spring 371. The spring 371 may be in a natural state and not elastically deformed. In the case of (1), the transition from the stop of the mover 31 of the linear motor 28 to the mold closing and clamping by the electromagnet 49 can be performed smoothly. On the other hand, in the case of (2), the current supplied to the linear motor 28 can be reduced, and the consumption of electric energy can be reduced.

  Subsequently, a predetermined current is supplied to the coil 48 of the electromagnet 49, and the attracting plate 22 is attracted to the rear platen 13 by the attracting force of the electromagnet 49, and the mold is closed and the mold is clamped.

In the state at the time of mold clamping, as shown in FIG. 6A, the spring 371 is sandwiched between the suction plate 22 and the rear platen 13 and is elastically contracted. The elastic restoring force of the spring 371 is sufficiently smaller than the attractive force by the electromagnet 49.

  In the mold opening process, when the energization of the electromagnet 49 to the coil 48 is interrupted, the suction plate 22 and the movable element 31 are accelerated in the mold opening direction by the elastic restoring force of the spring 371 as shown in FIG. Is done. Therefore, the current flowing through the coil 35 of the linear motor 28 for accelerating the mover 31 can be reduced. The energization of the coil 35 of the linear motor 28 may be cut off until the length of the spring 371 returns to the natural length.

  Since the spring 371 is attached to only one of the suction plate 22 and the rear platen 13 (the rear platen 13 in FIG. 6), the spring 371 is elastically deformed only when the movable element 31 is in the vicinity of the forward limit position. Therefore, the constant speed travel of the mover 31 is stabilized.

In the present embodiment, the spring 371 is elastically deformed by the attractive force of the electromagnet 49 that generates the mold clamping force . However, the spring 371 may be elastically deformed by driving the linear motor 28.

  The first to fourth embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation and inversion are possible.

  For example, the speed reduction mechanisms 70 to 270 of the above-described embodiment are mechanisms that absorb at least part of the kinetic energy of the mover 31 moving in the mold opening direction and decelerate the mover 31, but move in the mold closing direction. It can also be used as a mechanism that absorbs at least a part of the kinetic energy of the inner movable element 31 and decelerates the movable element 31. Further, both the speed reduction mechanisms may be provided in one injection molding machine.

DESCRIPTION OF SYMBOLS 10 Injection molding machine 15 Fixed mold 16 Movable mold 19 Mold apparatus 22 Suction plate 28 Linear motor 29 Stator 31 Movable element 35 Coil 60 Control part 70 Deceleration mechanism 71 Spring (elastic body)
77 Fixing member 271 Damper Sb Slide base

Claims (3)

A stationary platen to which a stationary mold is attached;
A movable platen to which a movable mold is attached;
A movable member that moves with the movable platen;
A fixed member disposed between the movable platen and the movable member;
A rod penetrating the fixed member and connecting the movable platen and the movable member;
The movable platen, the movable member that moves together with the movable member and the rod, and a stator that includes a linear motor that performs mold opening and closing operations.
The movable member and the fixed member constitute a mechanism for generating a clamping force by an attractive force of an electromagnet,
A plurality of elastic bodies that are elastically deformed by the attraction force of the electromagnet are disposed symmetrically about the rod ,
An injection molding machine , wherein when the attraction force of the electromagnet is released, the mover is accelerated in the mold opening direction by elastic restoring forces of the plurality of elastic bodies .   2. The injection molding machine according to claim 1, wherein the plurality of elastic bodies are not elastically deformed when mold closing is completed and elastically deformed when the mold is clamped. The injection molding machine according to claim 1, wherein the plurality of elastic bodies are elastically deformed when mold closing is completed.

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