TWI584935B - Injection molding machine - Google Patents

Description

Injection molding machine

The present invention relates to an injection molding machine.

The injection molding machine has a mold clamping device that performs mold closing, mold clamping, and mold opening of the mold device. The mold clamping device has a plurality of tie bars extending corresponding to the mold clamping force (for example, refer to Patent Document 1). The clamping force is applied to a plurality of tie bars so that the tie bars extend. The force that resists the extension of the tie rod is referred to as the axial force.

When there is a difference in the effective lengths of the plurality of tie bars, a difference in axial force is generated between the tie bars having a shorter effective length and the tie bars having a longer effective length. Here, the effective length of the tie rod means the interval between the members joined by the tie rods, for example, in a state where the mold clamping force does not function.

Since the tie rod is formed of a metallic material, the effective length of the tie rod varies depending on the temperature of the tie rod. The higher the temperature of the tie rod, the longer the effective length of the tie rod. By adjusting the temperature of the tie rod, the effective length of the tie rod can be adjusted and the balance of the axial force can be adjusted.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-249637

Conventionally, since the heat applied to the tie rod is gradually moved, the time until the temperature of the entire mold clamping device is stabilized is long, and the time until the balance of the axial force is stabilized is long.

The present invention has been made in view of the above problems, and a main object thereof is to provide an injection molding machine capable of shortening the time until the balance of the axial force is stabilized.

In order to solve the above problems, according to the present invention, there is provided an injection molding machine comprising: a plurality of tie bars extending in accordance with a mold clamping force; a heater for heating the tie bars; and heating by the heating The cooler is cooled by the heated tie rod, and the cooler is disposed on both axial sides of the tie rod via the heater.

According to the same aspect of the present invention, an injection molding machine capable of shortening the time until the balance of the axial force is stabilized is provided.

10‧‧‧Molding device

12‧‧‧Fixed platen

13‧‧‧ movable platen

16‧‧‧ tied

25‧‧‧heater

26‧‧‧cooler

27‧‧‧ Temperature detector

28‧‧‧Axial force detector

30‧‧‧Molding device

32‧‧‧Fixed mode

33‧‧‧ movable mold

70‧‧‧Operator

80‧‧‧ display device

90‧‧‧ Controller

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.

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

Fig. 3 is a view showing the positional relationship of the tie bars of the injection molding machine according to the embodiment, and is a view of the fixed pressure plate as seen from the movable platen side.

In the following, the embodiments of the present invention will be described with reference to the accompanying drawings.

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. Fig. 2 is a view showing a state at the time of mold clamping of the injection molding machine according to the embodiment. The injection molding machine has a frame Fr, a mold clamping device 10, an operation device 70, a display device 80, a controller 90, and the like.

The controller 90 has a CPU (Central Processing Unit) 91 and a memory medium 92 such as a memory. The controller 90 controls the mold clamping device 10, the operation device 70, the display device 80, and the like by executing a program stored in the memory medium 92 on the CPU 91.

The controller 90 is connected to the operating device 70 and the display device 80. The operation device 70 and the display device 80 can be constituted by, for example, a touch panel and integrated. The operating device 70 accepts an input operation performed by the user, and will input and lose The corresponding signal is output to the controller 90. The display device 80 displays an operation screen corresponding to the input operation in the operation device 70 under the control of the controller 90. The operation screen can be used for settings of the injection molding machine and the like. A plurality of operation screens are prepared to perform switching display or overlapping display. The user operates the operation device 70 while observing the operation screen displayed on the display device 80 to set the injection molding machine and the like.

Further, although the operation device 70 and the display device 80 of the present embodiment are integrated, they can be provided independently. Further, a plurality of operating devices 70 may be provided.

The mold clamping device 10 performs mold closing, mold clamping, and mold opening of the mold device 30. The mold clamping device 10 has a fixed platen 12, a movable platen 13, a rear platen 15, a tie rod 16, a toggle mechanism 20, and a mold clamping motor 21. In the following, the moving direction of the movable platen 13 at the time of mold closing (the right direction in the first drawing and the second drawing) is set to the front, and the moving direction of the movable platen 13 at the time of mold opening (in the first drawing and the second drawing) The left direction is set to the rear for explanation.

The fixed platen 12 is fixed to the frame Fr. A fixed die 32 is attached to the opposing surface of the fixed platen 12 and the movable platen 13.

The movable platen 13 is freely movable along a guide (for example, a guide rail) 17 laid on the frame Fr, and is movable forward and backward with respect to the fixed platen 12. A movable mold 33 is attached to the opposing surface of the movable platen 13 and 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 pressure plate 15 is coupled to the fixed pressure plate 12 at intervals, and is opened along the mold. The closed direction is movably placed on the frame Fr. In addition, the rear platen 15 can also move freely along the guides laid on the frame Fr. The guide of the rear platen 15 can be used in common with the guide 17 of the movable platen 13.

Further, in the present embodiment, the fixed platen 12 is fixed to the frame Fr, and the rear platen 15 is movable in the mold opening and closing direction with respect to the frame Fr. However, the rear platen 15 may be fixed to the frame Fr, and the fixed platen 12 may be fixed relative to the frame. Fr moves freely along the mold opening and closing direction.

The tie rod 16 connects the fixed pressure plate 12 and the rear pressure plate 15 at intervals. A plurality of tie rods 16 can be used. Each of the tie bars 16 is parallel to the mold opening and closing direction and extends in accordance with the mold clamping force.

The toggle mechanism 20 is disposed between the movable platen 13 and the rear platen 15. The toggle mechanism 20 is composed of a crosshead 20a, a plurality of links 20b, 20c, and the like. One of the links 20b is swingably attached to the movable platen 13, and the other link 20c is swingably attached to the rear platen 15. The links 20b and 20c are coupled to each other by a pin or the like so as to be expandable and contractible. By advancing and retracting the crosshead 20a, the plurality of links 20b, 20c expand and contract, and the movable platen 13 advances and retracts relative to the rear platen 15.

The mold clamping motor 21 is attached to the rear pressure plate 15, and the movable platen 13 is advanced and retracted by advancing and retracting the crosshead 20a. Between the mold clamping motor 21 and the crosshead 20a, a motion conversion mechanism that converts the rotational motion of the mold clamping motor 21 into a linear motion and transmits it to the crosshead 20a is provided. The motion conversion mechanism is constituted by, for example, a ball screw mechanism.

The action of the mold clamping device 10 is controlled by the controller 90. The controller 90 controls the mold closing process, the mold clamping process, and the mold opening process.

In the mold closing process, the movable platen 13 is advanced by driving the mold clamping motor 21, thereby bringing the movable mold 33 into contact with the fixed mold 32.

In the mold clamping process, the mold clamping force is generated by further driving the mold clamping motor 21. When the mold is closed, a cavity space is formed between the movable mold 33 and the fixed mold 32, and the cavity space can be filled with a liquid molding material. The molding material in the cavity space is solidified to become a molded article.

In the mold opening process, the movable mold plate 13 is retracted by driving the mold clamping motor 21, thereby separating the movable mold 33 from the fixed mold 32.

In the mold clamping device 10 of the present embodiment, the mold clamping motor 21 is provided as a drive source for moving the movable platen 13, but a hydraulic cylinder may be provided instead of the mold clamping motor 21. Further, the mold clamping device 10 may have a linear motor for mold opening and closing, or may have an electromagnet for mold clamping.

Fig. 3 is a view showing the positional relationship of the tie bars of the injection molding machine according to the embodiment, and is a view of the fixed pressure plate as seen from the movable platen side. The injection molding machine has four tie bars 16. When viewed from the mold opening and closing direction, the four tie bars 16 are arranged vertically symmetrically about the horizontal line L1, and are disposed symmetrically about the vertical line L2. The upper side than the horizontal line L1 is referred to as the top side, and the lower side than the horizontal line L1 is referred to as the bottom side. Further, the side closer to the operation device 70 than the vertical line L2 is referred to as the operation side, and the side opposite to the operation device 70 from the vertical line L2 is referred to as the opposite side of the operation side.

The clamping force is applied to the four tie bars 16 such that the tie bars 16 extend. The force that resists the extension of each tie rod 16 is referred to as an axial force. When there is a difference in the effective lengths of the four tie bars 16, a difference in axial force is generated between the tie bars 16 having a shorter effective length and the tie bars 16 having a longer effective length. Here, the tie rod The effective length of 16 means the interval between the fixed platen 12 and the rear platen 15 joined by the tie rod 16, and can be measured, for example, in a state where the mold clamping force does not function.

By adjusting the effective length of the tie rod 16, the balance of the axial force can be adjusted. The balance of the axial force is set, for example, such that the surface pressure of the fixed mold 32 and the movable mold 33 becomes a target distribution at the time of mold clamping. The distribution of the target may be either one of uniform distribution and uneven distribution, and may be set according to circumstances. Can reduce molding defects.

Since the tie rod 16 is formed of a metallic material, the effective length of the tie rod 16 may vary due to the temperature of the tie rod 16. The higher the temperature of the tie rod 16, the longer the effective length of the tie rod 16. By adjusting the temperature of the tie rod 16, the effective length of the tie rod 16 can be adjusted and the balance of the axial force can be adjusted.

Therefore, as shown in FIGS. 1 and 2, the heater 25, the cooler 26, the temperature detector 27, the axial force detector 28, and the like are attached to the respective tie bars 16. The mold clamping device 10 includes a heater 25, a cooler 26, a temperature detector 27, an axial force detector 28, and the like.

The heater 25 heats the tie rod 16 in order to adjust the effective length of the tie rod 16. The portion of the tie rod 16 heated by the heater 25 is referred to as a heating portion. The heater 25 is constituted by, for example, an electric heater such as a heater. Further, the heater 25 is not limited to the electric heater, and may be constituted, for example, by a warm water jacket or the like.

The cooler 26 cools the tie rod 16 heated by the heater 25. The portion of the tie rod 16 that is cooled by the cooler 26 is referred to as a cooling portion. The cooler 26 is composed, for example, of a water-cooled jacket. In addition, the cooler 26 is not limited The water-cooling jacket is set, for example, by a cooling fan or the like. The cooling method of the cooling fan may be either a forced air cooling method using a cooling fan or a natural air cooling method.

The cooler 26 is disposed on both axial sides of the tie rod 16 via the heater 25. The heating range of the tie rod 16 by the heater 25 can be defined. Thereby, the movement of the heat applied to the tie rod 16 from the heater 25 can be restricted, and the time until the temperature of the entire mold clamping device 10 is stabilized can be shortened, and the time until the balance of the axial force is stabilized can be shortened. Further, it is possible to manage the thermal expansion range of the tie rod 16 and to accurately manage the amount of change in the effective length due to the temperature change of the tie rod 16, and to adjust the axial force with high precision.

The temperature detector 27 detects the temperature of the tie rod 16 which is heated and cooled by the heater 25 and the cooler 26. For example, the temperature detector 27 is disposed in the vicinity of the heater 25 and detects the temperature of the heating portion of the tie rod. The temperature detector 27 outputs the detection result to the controller 90.

The controller 90 controls the heater 25 so that the actual value of the temperature of the heating portion of the tie rod 16 becomes a set value. Control can be either feedback control or feedforward control.

Further, the controller 90 of the present embodiment controls the heater 25 without controlling the cooler 26, but the cooler 26 can also be controlled. At this time, the controller 90 can control the cooler 26 so that the actual value of the temperature of the cooling portion of the tie rod 16 becomes the set value. The temperature of the cooling portion of the tie rod 16 is detected by a temperature detector different from the temperature detector 27. The temperature detector is disposed in the vicinity of the cooler 26.

The axial force detector 28 detects the axial force of the tie rod 16 that is heated and cooled by the heater 25 and the cooler 26. The axial force detector 28 is, for example, a strain ritual that detects the axial force of the tie rod 16 by detecting the strain of the tie rod 16.

Further, the axial force detector 28 of the above embodiment is a strain ceremony, but may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type or the like.

The axial force detector 28 outputs the detection result to the controller 90. The controller 90 can set the heating temperature of the tie rod 16 heated by the heater 25 so that the actual value of the axial force detected by the axial force detector 28 becomes the set value.

The axial force detector 28 is disposed on the opposite side of the heater 25 with the cooler 26 as a reference. An axial force detector 28 is disposed outside the heating range of the heater 25. The temperature rise of the axial force detector 28 can be suppressed, and the measurement error of the axial force detector 28 can be reduced.

For example, as shown in FIGS. 1 and 2, the axial force detector 28 is disposed on the rear side of the cooler 26, and the cooler 26 is disposed on the rear side of the heater 25. Further, the axial force detector 28 may be disposed on the front side of the cooler 26, and the cooler 26 is disposed on the front side of the heater 25.

Further, the axial force detector 28 of the present embodiment is disposed on the opposite side of the heater 25 with respect to the cooler 26, but may be disposed at a position overlapping the cooler 26. At this time, it is also possible to suppress the temperature rise of the axial force detector 28 and reduce the measurement error of the axial force detector 28.

The embodiment of the injection molding machine has been described above, but this The invention is not limited to the above-described embodiments and the like, and various modifications and improvements can be made within the scope of the gist of the invention described in the claims.

For example, in the above embodiment, the heater 25, the cooler 26, the temperature detector 27, the axial force detector 28, and the like are attached to all the tie bars 16, but they may be attached only to a part of the tie bars 16. For example, in the case where the controller 90 adjusts the axial force balance in the vertical direction (hereinafter referred to as "vertical axial force balance") and the axial force balance in the horizontal direction, it may be only four Three of the tie rods 16 are equipped with a heater 25, a cooler 26, and a temperature detector 27. Further, when the controller 90 adjusts only the vertical axial force balance, the heater 25, the cooler 26, and the temperature detector 27 may be attached only to the tie rod 16 on one of the top side and the bottom side. Further, when the controller 90 adjusts only the vertical axial force balance, the axial force detector 28 may be attached to one of the two tie bars 16 on the top side and one of the two tie bars 16 on the bottom side. .

Further, the mold clamping device 10 of the above-described embodiment is a horizontal mold clamping device in which the mold opening and closing direction is horizontal, but a vertical mold clamping device in which the mold opening and closing direction is a vertical direction may be used. The vertical mold clamping device has a lower platen as a fixed platen, an upper platen as a movable platen, a toggle joint, a toggle mechanism, and a tie rod. A lower die is mounted on the lower platen, and an upper die is mounted on the upper platen. The mold device is composed of a lower mold and an upper mold. The lower die can be mounted to the lower platen via a turntable. The elbow seat is disposed below the lower platen and is raised and lowered together with the upper platen. The toggle mechanism is disposed between the toggle seat and the lower platen. The tie rod is parallel to the vertical direction and extends through the lower pressure plate to join the upper pressure plate and the toggle seat. The number of tie rods is usually three. In addition, the number of tie bars is not particularly limited.

10‧‧‧Molding device

12‧‧‧Fixed platen

13‧‧‧ movable platen

15‧‧‧ rear platen

16‧‧‧ tied

17‧‧‧ Guides

20‧‧‧Toggle mechanism

20a‧‧‧ crosshead

20b‧‧‧ Connecting rod

20c‧‧‧ connecting rod

21‧‧‧Molded motor

25‧‧‧heater

26‧‧‧cooler

27‧‧‧ Temperature detector

28‧‧‧Axial force detector

30‧‧‧Molding device

32‧‧‧Fixed mode

33‧‧‧ movable mold

70‧‧‧Operator

80‧‧‧ display device

90‧‧‧ Controller

91‧‧‧CPU

92‧‧‧Memory Media

Fr‧‧ frame

Claims (3)

An injection molding machine comprising: a plurality of tie bars extending corresponding to a mold clamping force; a heater for heating the tie bars; and cooling for cooling the tie bars heated by the heater The cooler is disposed on both axial sides of the tie rod via the heater. The injection molding machine according to claim 1, further comprising: a temperature detector that detects a temperature of the tie rod heated by the heater; and the aforementioned detection by the temperature detector The actual value of the temperature of the tie rod controls the controller of the aforementioned heater. The injection molding machine according to claim 1 or 2, further comprising: an axial force detector for detecting an axial force of the tie rod heated and cooled by the heater and the cooler, the shaft The force detector is disposed at a position opposite to the heater or a position overlapping the cooler, with reference to the cooler.