TWI595996B - Injection molding machine and injection molding method - Google Patents

Description

Injection molding machine and injection molding method

The present invention relates to an injection molding machine and an injection molding method.

The injection molding machine performs mold closing, mold clamping, and mold opening of the mold apparatus. The mold device is composed of, for example, a fixed mold and a movable mold. A cavity space is formed between the fixed mold and the movable mold in the mold clamping state, and the molding material is filled in the cavity space. The molding material filled in the cavity space is hardened and ejected as a molded article after the mold is opened.

The injection molding machine has a mold clamping force generating portion that generates a mold clamping force by an adsorption force of an electromagnet (for example, see Patent Document 1). The mold clamping force generation unit includes a first block and a second block in which the suction force acts. When the mold is closed, a gap is formed between the first block and the second block, and the first block and the second block are not in contact with each other.

(previous technical literature) (Patent Literature)

Patent Document 1: International Publication No. 2005/090052

In order to suppress deformation when a moment is generated by the adsorption force, the support member of the first block and the support member of the second block have high rigidity.

The present invention has been made in view of the above circumstances, and a main object thereof is to provide an injection molding machine capable of reducing rigidity of at least one of a support member of a first block and a support member of a second block.

In order to solve the above problems, according to the present invention, there is provided an injection molding machine comprising: a mold clamping force generating portion that generates a mold clamping force by an adsorption force of an electromagnet, wherein the mold clamping force generating portion includes the aforementioned suction force In the first block and the second block, the first block has a contact portion that contacts the second block at least in a part of the opposing portion of the second block.

According to the same aspect of the invention, an injection molding machine capable of reducing rigidity of at least one of the support member of the first block and the support member of the second block is provided.

10‧‧‧ Injection molding machine

11‧‧‧Frame

12‧‧‧Fixed platen

13‧‧‧ movable platen

15‧‧‧ rear platen

15a‧‧‧Contacts

15b‧‧‧ Non-contact department

18‧‧‧Adsorption plate

18a‧‧‧Contacts

18b‧‧‧ Non-contact department

19‧‧‧ Connecting rod

21‧‧‧Linear motor

24‧‧‧Molding force generation department

25‧‧‧Electromagnet

26‧‧‧Adsorption Department

27‧‧‧ coil

28‧‧‧ slots

29‧‧‧ magnetic core

Fig. 1 is a view showing a state at the time of completion of mold opening of the injection molding machine according to the embodiment of the present invention.

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

Fig. 3 is a view showing a state at the time of mold clamping of the injection molding machine according to the embodiment of the present invention.

Fig. 4 is a view showing a state at the time of mold clamping of the mold clamping force generating portion of the first modification.

Fig. 5 is a view showing a state at the time of mold clamping of the mold clamping force generating portion of the second modification.

Fig. 6 is a view showing a state at the time of mold clamping of the mold clamping force generating portion of the third modification.

In the following, the embodiments of the present invention will be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same or corresponding elements, and the description is omitted. In addition, the moving direction of the movable platen at the time of mold closing is set to the front, and the moving direction of the movable platen at the time of mold opening is set to the rear.

Fig. 1 is a view showing a state at the time of completion of mold opening of the injection molding machine according to the embodiment of the present invention. Fig. 2 is a view showing a state at the time of completion of mold closing of the injection molding machine according to the embodiment of the present invention. Fig. 3 is a view showing a state at the time of mold clamping of the injection molding machine according to the embodiment of the present invention.

The injection molding machine 10 has a frame 11, a fixed platen 12, a movable platen 13, a rear platen 15, an adsorption plate 18, a link 19, and a linear motor 21 as a die opening and closing drive unit. The rear platen 15 corresponds to the one described in the patent application scope. The fixing member and the suction plate 18 correspond to the movable member described in the patent application.

The fixed platen 12 is placed on the frame 11 in a retractable manner via the fixed platen support member 42. A fixed mold 32 is attached to a surface of the fixed platen 12 that faces the movable platen 13.

In addition, the fixed platen 12 may be fixed to the guide block via the fixed platen support member 42, and the guide block may be freely movable along the guide member laid on the frame 11. The guide of the fixed platen 12 can be shared with the guide of the movable platen 13. At this time, the fixed platen 12 and the movable platen 13 are freely movable along the guide.

The movable platen 13 is fixed to the guide block 14 via the movable platen supporting member 43, and the guide block 14 is freely movable along a guide (for example, a guide rail) 17 laid on the frame 11. Thereby, the movable platen 13 can move forward and backward with respect to the fixed platen 12. A movable mold 33 is attached to a surface of the movable platen 13 that faces the fixed platen 12.

The mold closing, the mold clamping, and the mold opening are performed by advancing and retracting the movable platen 13 with respect to the fixed platen 12. The mold device 30 is constituted by the fixed mold 32 and the movable mold 33.

The rear platen 15 is coupled to the fixed platen 12 by a plurality of (for example, four) tie rods 16. The rear platen 15 is disposed between the movable platen 13 and the suction plate 18, and is fixed to the frame 11 via the rear platen support member 45. A through hole is formed in a central portion of the rear platen 15, and a link 19 is inserted through the through hole. The link 19 connects the movable platen 13 and the suction plate 18.

Further, in the present embodiment, the fixed platen 12 is fixed relative to the frame 11 The rear platen 15 is fixed relative to the frame 11, but the rear platen 15 can be moved forward and backward with respect to the frame 11, and the fixed platen 12 is fixed relative to the frame 11.

The suction plate 18 is coupled to the movable platen 13 by the link 19, and moves together with the movable platen 13. The suction plate 18 is fixed to the slide base 20 via the suction plate support member 48, and the slide base 20 is freely movable along the guide 17 laid on the frame 11. Thereby, the adsorption plate 18 can move forward and backward further than the rear platen 15.

The linear motor 21 moves the movable platen 13 and the suction plate 18 connected by the link 19 with respect to the frame 11. The linear motor 21 is disposed, for example, between the suction plate 18 and the frame 11, and the urging force generated by the linear motor 21 is transmitted to the movable platen 13 via the adsorption plate 18.

Further, the linear motor 21 may be disposed between the movable platen 13 and the frame 11, and the urging force generated by the linear motor 21 may be transmitted to the adsorption plate 18 via the movable platen 13.

The linear motor 21 includes a stator 22 and a rotor sub 23 . The stator 22 is formed on the frame 11, and the rotor 23 is formed on the slide base 20. When a predetermined current is supplied to the coil of the rotor 23, the rotor 23 can advance and retreat by the interaction of the magnetic field formed by the current flowing through the coil and the magnetic field formed by the permanent magnet of the stator 22. As a result, the suction plate 18 and the movable platen 13 advance and retreat with respect to the frame 11, thereby performing mold closing and mold opening. Alternatively, the arrangement of the coil and the permanent magnet may be interchanged, and other coils may be used instead of the permanent magnet.

In addition, as the mold opening and closing drive unit, for example, it is also possible to use rotation including The motor and the fluid pressure cylinder that converts the rotary motion of the rotary motor into a linear motion ball screw or a hydraulic cylinder are used instead of the linear motor 21.

The mold clamping force generating portion 24 is composed of a rear pressure plate 15 and an adsorption plate 18, and generates a mold clamping force by the adsorption force of the electromagnet 25. One of the rear platen 15 and the suction plate 18 corresponds to the first block described in the patent application, and the other corresponds to the second block described in the patent application. The first block and the second block are relatively easy to move forward and backward.

A predetermined portion of the suction surface (rear end surface) of the rear platen 15, for example, a groove 28 for accommodating the coil 27 of the electromagnet 25 is formed around the link 19, and a magnetic core 29 of the electromagnet 25 is formed inside the groove 28. The adsorption unit 26 is formed in a predetermined portion surrounding the adsorption surface (front end surface) of the adsorption plate 18, for example, the link 19, and is opposed to the electromagnet 25. When a current is supplied to the coil 27 of the electromagnet 25, an adsorption force is generated between the electromagnet 25 and the adsorption portion 26, and a mold clamping force is generated. The magnetic core 29 and the adsorption portion 26 may be formed of a magnetic material such as iron.

Further, although the electromagnet 25 of the present embodiment is formed as a part of the rear platen 15, it may be formed separately from the rear platen 15. Further, the adsorption unit 26 of the present embodiment is formed as a part of the adsorption plate 18, but may be formed separately from the adsorption plate 18. Further, the arrangement of the electromagnet 25 and the adsorption unit 26 may be interchanged. That is, the electromagnet 25 can be formed on the side of the adsorption plate 18, and the adsorption portion 26 can be formed on the side of the rear platen 15. Further, an electromagnet may be formed on both sides of the rear platen 15 side and the suction plate 18 side. Further, a plurality of electromagnets may be formed on at least one of the rear platen 15 side and the suction plate 18 side. The plurality of electromagnets constituting the mold clamping force generating portion can be separately entered Line control.

Next, an injection molding method using the injection molding machine 10 having the above configuration will be described. The injection molding method has a mold closing process, a mold clamping process, and a mold opening process.

In the mold closing process, the linear motor 21 is driven to advance the movable platen 13. As shown in Fig. 2, the mold closing is completed by the movable mold 33 coming into contact with the fixed mold 32. At the time when the mold closing is completed, a predetermined gap δ can be formed between the rear platen 15 and the adsorption plate 18, that is, between the electromagnet 25 and the adsorption portion 26.

In the mold clamping process, the electromagnet 25 is driven to generate an adsorption force between the electromagnet 25 and the adsorption portion 26. By the suction force, a mold clamping force is generated between the movable platen 13 and the fixed platen 12. A cavity space is formed between the fixed mold 32 and the movable mold 33 in the mold clamping state, and a molding material (for example, molten resin) is filled in the cavity space. The molding material filled in the cavity space is hardened to become a molded article.

In the mold opening process, the linear motor 21 is driven to retract the movable platen 13. After the mold opening is completed, the molded article is ejected from the mold device 30.

Next, the mold clamping force generation unit 24 will be described in detail with reference to FIGS. 1 to 3 again. The rear platen 15 and the suction plate 18 are disposed on one side of the frame 11 (upper side in Fig. 3).

The magnetic flux of the electromagnet 25 is easily passed through one side. Since the frame 11 has a magnetic permeability higher than that of air, the balance of the magnetic flux density is broken, thereby breaking the balance of the adsorption force. Specifically, between the rear platen 15 and the adsorption plate 18, the adsorption force of the upper portion is stronger than the adsorption force of the lower portion. by Thus, a moment is generated in the rear platen 15 and the suction plate 18.

Therefore, the rear platen 15 has the contact portion 15a which is in contact with the adsorption plate 18 at least at the time of mold clamping only in a portion of the portion opposite to the adsorption plate 18. The contact portion 15a is formed only at an end portion (upper end portion in Fig. 3) on the opposite side of the frame 11 from the suction plate 18 in the rear platen 15. The rear platen 15 has a non-contact portion 15b at the remaining portion of the portion opposite to the suction plate 18.

Similarly, the suction plate 18 has a contact portion 18a which is in contact with the rear platen 15 at least at the time of mold clamping only in a portion of the portion opposite to the rear platen 15. The contact portion 18a is formed only at an end portion (upper end portion in Fig. 3) opposite to the frame 11 in the opposing portion of the suction plate 18 and the rear platen 15. The suction plate 18 has a non-contact portion 18b at the remaining portion of the portion opposite to the rear platen 15.

According to the present embodiment, the first block and the second block are in contact at the time of mold clamping, and the contact portion 15a of the rear platen 15 and the contact portion 18a of the suction plate 18 are in contact with each other at the time of mold clamping. Therefore, a repulsive force is generated, so that the moment generated by the equilibrium imbalance of the adsorption force can be cancelled. Thereby, the burden applied to the rear platen supporting member 45 and the suction plate supporting member 48 is small, so that the rigidity of the rear platen supporting member 45 and the suction plate supporting member 48 can be reduced. Moreover, the imbalance of the adsorption force is difficult to cause the balance of the mold clamping force to be unbalanced, and it is easy to maintain the balance of the mold clamping force.

Further, the cause of the imbalance in the adsorption force in the present embodiment is the presence of the frame 11, but the reason may be various. For example, when the adsorption force acts between the rear platen 15 and the adsorption plate 18, due to the adsorption plate branch Since the lower end portion of the stay member 48 is restricted, the upper end portion of the suction-plate supporting member 48 may be displaced forward with respect to the lower end portion of the suction-plate supporting member 48, and the suction-plate supporting member 48 may be tilted forward. As a result, the adsorption plate 18 is tilted forward, and the gap between the adsorption plate 18 and the rear pressure plate 15 becomes uneven, so that the balance of the adsorption force is unbalanced. For the same reason, there is also a situation in which the balance of the adsorption force is unbalanced due to the backward tilting of the rear platen 15. The same applies to the first to third modifications described below.

The contact portion 15a of the rear platen 15 and the contact portion 18a of the suction plate 18 may be contacted at the time of mold clamping, and may not be in contact at the end of mold closing. When the mold closing is completed, the adsorption surface of the rear platen 15 and the adsorption surface of the adsorption plate 18 may be perpendicular to the mold opening and closing direction. Due to the imbalance of the adsorption force, at least one of the rear platen 15 and the adsorption plate 18 (the adsorption plate 18 in Fig. 3) is deformed, whereby the contact portion 15a and the contact portion 18a can make contact.

The gap δ at the end of the mold closing can be set narrowly so as to bring the contact portion 15a of the rear platen 15 into contact with the contact portion 18a of the suction plate 18 at the time of mold clamping. The narrower the gap δ, the smaller the magnetic resistance, and the ability to generate a prescribed mold clamping force with less power.

On the other hand, a gap is formed between the non-contact portion 15b of the rear platen 15 and the non-contact portion 18b of the suction plate 18 at the time of mold clamping. Since only a part of the adsorption surface is in contact, the repulsive force generated by the contact is smaller than the adsorption force, and a predetermined mold clamping force can be generated.

Further, in the present embodiment, the contact portion 15a of the rear platen 15 and the contact portion 18a of the suction plate 18 are not in contact at the end of the mold closing, but they may be in contact at the end of the mold closing. For example, there may be an adsorption plate support member 48 It is deflected by the gravity acting on the adsorption plate 18, so that the adsorption plate 18 is tilted forward. Therefore, a part of the suction plate 18 and a part of the rear pressure plate 15 can also be contacted at the end of the mold closing. Similarly, the rear platen 15 is tilted backward by the deflection of the rear platen support member 45, so that a portion of the rear platen 15 and a portion of the suction plate 18 can also be brought into contact. The same applies to the first to third modifications described below.

Further, the contact portion 15a of the present embodiment is formed as a part of the rear platen 15, but may be formed separately from the rear platen 15. At this time, the rear platen 15 and the contact portion 15a constitute a fixed block, and the fixed block corresponds to any one of the first block and the second block described in the patent application. At this time, the contact portion 15a may be formed of any one of a magnetic material such as iron or a non-magnetic material such as a resin. The same applies to the first to third modifications described below.

Similarly, the contact portion 18a of the present embodiment is formed as a part of the adsorption plate 18, but may be formed separately from the adsorption plate 18. At this time, the adsorption plate 18 and the contact portion 18a constitute a movable block, and the movable block corresponds to any one of the first block and the second block described in the patent application. At this time, the contact portion 18a may be formed of any one of a magnetic material and a non-magnetic material. The same applies to the first to third modifications described below.

However, according to the present embodiment, the contact portion 15a of the rear platen 15 is formed only at the end of the rear platen 15. Similarly, the contact portion 18a of the suction plate 18 is formed only at the end of the suction plate 18. A repulsive force is generated at a position away from the center of the moment, thereby easily canceling the moment. The center of the moment and the center of the link 19 may be the same height from the frame 11.

Further, in the present embodiment, the rear platen 15 and the suction plate 18 are large. The same size is obtained, so that the ends of the rear platen 15 and the suction plate 18 are in contact with each other when the mold is closed, but when the rear platen 15 and the suction plate 18 are of different sizes, one of the ends can be in contact with the other part. . The same applies to the first to third modifications described below.

Further, according to the present embodiment, the contact portion 15a of the rear platen 15 is formed only at the upper end portion of the rear platen 15. Similarly, the contact portion 18a of the suction plate 18 is formed only at the upper end portion of the suction plate 18. Since the repulsive force is generated on one side of the link 19, the mold clamping force is less reduced due to the repulsive force than when the repulsive force is generated symmetrically around the link 19. Most of the adsorption force can be used as a mold clamping force, and the utilization efficiency of the adsorption force is good.

Further, in the present embodiment, the upper end portion of the rear platen 15 is in contact with the upper end portion of the suction plate 18, but the contact portion can be appropriately changed depending on the balance of the adsorption force. For example, the lower end portion of the rear platen 15 may be brought into contact with the lower end portion of the suction plate 18. Further, the side end portion of the rear platen 15 may be brought into contact with the side end portion of the suction plate 18. Further, the outer peripheral portion of the rear platen 15 and the outer peripheral portion of the suction plate 18 may be brought into contact with each other. The same applies to the first to third modifications described below.

Fig. 4 is a view showing a state at the time of mold clamping of the mold clamping force generating portion of the first modification. The adsorption surface of the adsorption plate 18A of the first modification has a step, and has a contact portion 18Aa and a non-contact portion 18Ab via a step. The contact portion 18Aa and the non-contact portion 18Ab can be divided by the step. The contact portion 18Aa and the non-contact portion 18Ab may be surfaces that are perpendicular to the mold opening and closing direction at the end of mold closing. The contact portion 18Aa is formed at an end portion opposite to the frame 11 in the opposing portion of the suction plate 18A from the rear platen 15 (in FIG. 4 is Upper end).

According to the present modification, the contact portion 15a of the rear platen 15 and the contact portion 18Aa of the suction plate 18A are in contact at least at the time of mold clamping. Therefore, the same effects as those of the above embodiment can be obtained.

Further, in the present modification, a step is formed on the adsorption surface of the adsorption plate 18A, and no step is formed on the adsorption surface of the rear platen 15, but a step may be formed on the two adsorption surfaces or only on the adsorption surface of the rear platen 15. At this time, the rear platen 15 may have the contact portion 15a and the non-contact portion 15b with a step difference therebetween. The contact portion 15a and the non-contact portion 15b can be divided by the step.

Fig. 5 is a view showing a state at the time of mold clamping of the mold clamping force generating portion of the second modification. The adsorption surface of the adsorption plate 18B of the second modification has a vertical portion that is perpendicular to the mold opening and closing direction at the end of mold closing, and an inclined portion that is inclined with respect to the mold opening and closing direction at the end of mold closing, and has a contact portion 18Ba at the inclined portion. Since the contact portion 18Ba is formed in a line shape or a dot shape and is in line contact or point contact, the contact area is small, the repulsive force is small, and the mold clamping force is large as compared with the case of the surface contact. The contact portion 18Ba is formed at an end portion (upper end portion in Fig. 5) on the opposite side of the frame 11 from the opposing portion of the suction plate 18B and the rear platen 15. The non-contact portion 18Bb is formed in a part of the inclined portion and a vertical portion.

According to the present modification, the contact portion 15a of the rear platen 15 and the contact portion 18Ba of the suction plate 18B are in contact at least at the time of mold clamping. Therefore, the same effects as those of the above embodiment can be obtained.

Further, the adsorption surface of the adsorption plate 18B of the present modification partially has an inclined portion, but may have only an inclined portion. Including the inclined portion of the contact portion 18Ba It can be formed separately from the adsorption plate 18B.

Further, the suction surface of the rear platen 15 of the present modification has only a vertical portion perpendicular to the mold opening and closing direction at the end of the mold closing, but may have an inclined portion that is inclined with respect to the mold opening and closing direction at the end of the mold closing, and may be inclined at the inclined portion. There is a contact portion 15a. When the adsorption surface of the rear platen 15 has an inclined portion, the adsorption surface of the adsorption plate 18B may have no inclined portion or may have only a vertical portion.

Fig. 6 is a view showing a state at the time of mold clamping of the mold clamping force generating portion of the third modification. In the third modification, the pressure plate 15C includes a pressure plate main body having an adsorption surface, and a contact portion 15Ca attached to the rear pressure plate main body. The contact portion 15Ca is formed at an end portion (upper end portion in FIG. 6) on the opposite side of the frame 11 from the suction plate 18C in the rear platen 15C. The non-contact portion 15Cb is the entire adsorption surface of the rear platen body.

Further, the adsorption plate 18C according to the third modification includes an adsorption plate main body having an adsorption surface, and a contact portion 18Ca attached to the adsorption plate main body. The contact portion 18Ca is formed at an end portion (upper end portion in FIG. 6) on the opposite side of the frame 11 from the opposing portion of the rear platen 15C in the suction plate 18C. The non-contact portion 18Cb is the entire adsorption surface of the adsorption plate main body.

According to the present modification, the contact portion 15Ca of the rear platen 15C and the contact portion 18Ca of the suction plate 18C are in contact at least at the time of mold clamping. Therefore, the same effects as those of the above embodiment can be obtained.

Although the embodiment of the injection molding machine has been described above, the present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope of the gist of the invention.

For example, the injection molding machine according to the above embodiment is a horizontal type in which the mold opening and closing direction is horizontal, but may be a vertical type in which the mold opening and closing direction is the vertical direction.

10‧‧‧ Injection molding machine

11‧‧‧Frame

12‧‧‧Fixed platen

13‧‧‧ movable platen

14‧‧‧Guiding block

15‧‧‧ rear platen

15a‧‧‧Contacts

15b‧‧‧ Non-contact department

16‧‧‧ tied

17‧‧‧ Guides

18‧‧‧Adsorption plate

18a‧‧‧Contacts

18b‧‧‧ Non-contact department

19‧‧‧ Connecting rod

20‧‧‧Sliding base

21‧‧‧Linear motor

22‧‧‧ Stator

23‧‧‧Rotor

24‧‧‧Molding force generation department

25‧‧‧Electromagnet

26‧‧‧Adsorption Department

27‧‧‧ coil

28‧‧‧ slots

29‧‧‧ magnetic core

30‧‧‧Molding device

32‧‧‧Fixed mode

33‧‧‧ movable mold

42‧‧‧Fixed plate support members

43‧‧‧ movable platen support member

45‧‧‧ Rear platen support member

48‧‧‧Adsorption plate support member

Claims (6)

An injection molding machine, comprising: a fixed pressure plate to which a fixed mold is mounted; a movable pressure plate on which a movable mold is mounted; a movable member that moves together with the movable pressure plate; and a fixing between the movable member and the movable pressure plate And a clamping force generating portion that generates a clamping force by an adsorption force of the electromagnet, wherein the clamping force generating portion includes the first block and the second block in which the adsorption force acts, and the first block is only in the foregoing A part of the opposing portion of the second block has a contact portion that contacts the second block at least during mold clamping, and one of the movable member and the fixing member is the first block, and the other is the second block. The injection molding machine according to the first aspect of the invention, wherein the contact portion is formed at an end portion of the first block facing the second block. The injection molding machine according to claim 2, wherein the injection molding machine has a frame in which the first block and the second block are disposed, and the contact portion is formed in the first block and the first Among the two opposing portions, the end portion on the opposite side to the aforementioned frame. An injection molding method, characterized in that: a fixed pressure plate mounted with a fixed mold; a movable platen to which a movable mold is attached; a movable member that moves together with the movable platen; and a fixing member that is disposed between the movable member and the movable platen, and has a space between the first block and the second block a mold clamping process for generating an clamping force of the electromagnet to generate a mold clamping force, and at least a part of the facing portion of the first block and the second block are in contact with each other, at least one of the movable member and the fixing member The first block and the other block are the aforementioned second block. The injection molding method according to claim 4, wherein at least the end portion of the first block facing the second block is brought into contact with the second block at the time of mold clamping. The injection molding method according to claim 5, wherein the first block and the second block are disposed in a frame, and at least a part of the first block is opposed to the second block at the time of mold clamping. The end opposite to the frame is in contact with the second block.