JPH08244083A - Method for selecting clamping of toggle type clamping device and its apparatus - Google Patents

Abstract

PURPOSE: To provide a method for selecting a clamping device of a toggle type clamping device and its apparatus wherein locked condition of the clamping device is made into unlocked condition in accordance with the application when the electric source is shut down, e.g. when the electric current is cut off. CONSTITUTION: The amt. S of offset of a toggle link mechanism 13 of a toggle type clamping device is set by means of a setting tool 27 to select the clamping device 11 in such a way that it becomes either locked or unlocked condition with the electric current is cut off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping selection method for a toggle type mold clamping device of an injection molding machine and a device therefor.

[0002]

2. Description of the Related Art In a conventional toggle type mold clamping device for an injection molding machine, when the power is cut off due to a power failure or the like in the mold clamping state,
The toggle link mechanism of the toggle mold clamping device holds the mold clamping lock state.

[0003]

In the toggle link mechanism of the conventional toggle type mold clamping device, if the mold clamping lock state is continuously maintained due to a power failure or the like, the toggle link mechanism will be opened even if the power failure ends and the mold is opened. The mold sometimes did not open due to the oil film running out of the toggle bush of the mechanism.

The present invention has been made to solve the above problems, and an object thereof is to lock a mold clamping lock state to an unlock state according to the application at the time of power interruption such as power failure. To provide a mold clamping selection method and device for a toggle type mold clamping device.

[0005]

According to the method for selecting a mold clamping device of a toggle type mold clamping device of an injection molding machine according to the present invention, an offset amount of a toggle link mechanism of the toggle type mold clamping device is set by a setting device, and power is shut off. At this time, the mold clamping device is selected such that the mold clamping state is either a locked state or an unlocked state.

It is preferable to set the offset amount as the position of the crosshead.

In the mold clamping selection device of the toggle type mold clamping device of the injection molding machine according to the present invention, the mold clamping selection device of the toggle type mold clamping device which expands and contracts the toggle link mechanism by the motor sets the offset amount of the toggle link mechanism. A controller having a setting device for controlling the motor, a driver amplifier for driving the motor in response to a command signal from the controller, and a pulse encoder for detecting the offset amount according to the rotation speed of the motor. It is characterized by holding.

It is preferable to set the offset amount as the position of the crosshead.

[0009]

[Function] When the offset amount is set by the setter and the mold clamping device is selected to be in the locked state or the unlocked state when the power is cut off, the command signal from the setter is output to the driver amplifier, The mold clamping motor rotates a predetermined number of revolutions to maintain the mold clamping state. The pulse encoder attached to the motor detects the predetermined rotation speed.

When the power supply is cut off and the lock state is selected, the mold continues to be in the mold clamping state. If you select the unlocked state, the motor rotates in the loosening direction,
The toggle link mechanism moves and stops so that the offset amount increases. Therefore, even if it is left for a long time, the molten metal film of the toggle bush of the toggle link mechanism will not be cut off, and opening and closing of the mold will not be difficult even when the power is restored.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an essential part showing a toggle type mold clamping device provided with a mold clamping selection device 30 according to the present invention. As shown in the figure, the injection molding machine 1 includes a fixed platen 3 to which a fixed mold 2 is attached and a movable platen 5 to which a movable mold 4 is attached. The fixed platen 3 and the movable platen 5 are arranged so as to face each other, and the fixed platen 3 is fixed on the bed 6 of the injection molding machine 1. An injection unit 7 for injecting a molding material into the mold cavity formed by the fixed mold 2 and the movable mold 4 is provided on the back surface side of the stationary platen 3. Further, an end housing 8 is installed on the bed 6 on the side opposite to the fixed plate 3 with respect to the movable plate 5. The end housing 8 and the fixed plate 3 are
The ends are connected to each other via four parallel tie bars 9 fixed to the stationary platen 3. The movable platen 5 is slidably supported by these tie bars 9. Thus
The movable platen 5 is configured to be movable in a direction toward or away from the fixed platen 3.

The end housing 8 is movably supported on the bed 6 via wheels or the like. A thread is formed at the end of the tie bar 9 on the side of the end housing 8, and a tie bar nut 10 that is supported immovably in the axial direction with respect to the end housing 8 is meshed with the thread. The tie bar nut 10 is rotationally driven by a driving device (not shown).
In this way, by rotating the tie bar nut 10,
The distance between the end housing 8 and the fixed platen 3 can be adjusted.

A toggle type mold clamping device 11 for moving the movable platen 5 is provided between the end housing 8 and the movable platen 5. The mold clamping device 11 includes an end housing 8
It has a cross head 12 supported by the tie bar 9 and moved in the axial direction of the tie bar 9, and a toggle link mechanism 13 operated by the cross head 12.

The crosshead 12 is an end housing 8.
It is fixed to the tip of a screw shaft 14 penetrating through. The screw shaft 14 is meshed with a ball nut 15 mounted so as to be rotatable with respect to the end housing 8 but immovable in the axial direction. The ball nut 15
The pulley 16 is fixed to the
It is adapted to be rotationally driven via a belt 19 by a mold clamping motor 18 attached to the end housing 8 via a bracket 17.

The toggle link mechanism 13 has a pin 20.
It is composed of a long link 21, a short link 22, and a cross link 23 that are rotatably connected to each other via. The other end of the long link 21 is pin-connected to the movable plate 5, and the other end of the short link 22 is pin-connected to the arm 8a of the end housing 8. The other end of the cross link 23 is pin-connected to the cross head 12.

Thus, when the motor 18 is operated to rotate the ball nut 15 forward or backward, the crosshead 12 at the tip of the screw shaft 14 moves forward and backward with respect to the end housing 8, and the toggle link mechanism 13 expands and contracts. The movable platen 5 is configured to move toward or away from the fixed platen 3. Then, the mold is closed, the mold is clamped, and the mold is opened.

As shown in FIG. 1, when the motor 18 is operated to extend the toggle link mechanism 13 and perform mold clamping, the long link 21 and the short link 22 of the toggle link mechanism 13 are formed in a substantially straight line. , Is bent inward from the substantially straight line by the offset amount S.

The mold clamping selection device 30 according to the present embodiment is a setting device 2 for setting the offset amount S of the toggle link mechanism 13.
Control device 25 in which 7 is incorporated, and the control device 25
The driver amplifier 26 drives the motor 18 by a command signal output from the pulse amplifier 24 and the pulse encoder 24 detects the offset amount S by the rotation speed of the motor 18. The pulse encoder 24 is
A pulse signal corresponding to the rotation speed of the motor 18 is generated.

Usually, the offset amount S is determined by the crosshead 1
The position 2 is detected by the pulse encoder 24 attached to the motor 18 and controlled.

The setting device 27 incorporated in the control device 25 can select the mold clamping device 11 to be in the locked state or the unlocked state in the mold clamping state at the time of power interruption such as power failure. it can. The setting device 27 may be a numerical input type or a switching type (lock / unlock).
That is, it is possible to set the offset amount S of the toggle link mechanism 13 to a large value so that the mold clamping device 11 is unlocked when the power is cut off. If unlocked in the melted state, the mold may be damaged, so set the offset amount S to around 0 mm and
It can also be selected to be locked. In addition,
The control device 25 controls the process of the injection molding machine 1.

Next, the operation of the above embodiment will be described.

Normally, the offset amount S is set to around 0 mm to prevent the mold from opening due to the resin pressure in the mold, so that there are advantages such as power consumption, but there is a power failure in the mold clamping state. If this happens, if the locked state is maintained and the product is left for a long time, the oil film on the pin 20 of the toggle link mechanism 13 will be cut off, and it may be difficult to open the mold even when the power is restored. Therefore, the setting device 27 sets the offset amount S in the range of several mm to several tens of mm, preferably 1 to 8 mm so that the mold clamping device 11 can be operated when the power is shut off.
Is selected to be either a locked state or an unlocked state in the mold clamping state, a command signal from the setter 27 is output to the driver amplifier 26 and the motor 18 for mold clamping is
Rotates for a predetermined number of rotations to maintain the mold clamped state. The pulse encoder 2 attached to the motor 18 detects the predetermined number of revolutions.
4 does.

When the power supply is cut off, if the locked state is selected, the mold continues to be in the clamped state. When the unlocked state is selected, the motor 18 rotates in the loosening direction, and the toggle link mechanism 13 moves so as to increase the offset amount S and stops. Therefore, even if it is left for a long time, the molten metal film of the toggle bush of the toggle link mechanism 13 will not be cut off, and opening and closing of the mold will not be difficult even if the power is restored.

In the above embodiment, the electric injection molding machine is described as an example, but a hydraulic injection molding machine can also perform the same control.

[0025]

Since the present invention is constructed as described above, the following effects can be obtained. That is, by setting the offset amount with the setting device, it is possible to select whether the mold clamping device will be in the locked state or the unlocked state in the mold clamping state at the time of power interruption such as power failure. Depending on the unlocked state,
It is possible to prevent the situation where the mold is not opened due to the oil film running out of the toggle bush of the toggle link mechanism.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a toggle type mold clamping device provided with a mold clamping selection device according to the present invention.

[Explanation of symbols]

 11 Mold clamping device 12 Crosshead 13 Toggle link mechanism 14 Screw shaft 15 Ball nut 16 Pulley 17 Bracket 18 Motor 19 Belt 20 Pin 21 Long link 22 Short link 23 Cross link 24 Pulse encoder 25 Control device 26 Driver amplifier 27 Setting device 30 type Tightening selection device S offset amount

Claims (4)

[Claims] 1. The set amount (S) of the toggle link mechanism (13) of the toggle type mold clamping device is set by a setting device (27) so that the mold clamping device (11) is in the mold clamping state when the power is cut off. A method for selecting a mold clamping of a toggle type mold clamping device of an injection molding machine, characterized by selecting either a locked state or an unlocked state. 2. The mold clamping selection method for a toggle type mold clamping device of an injection molding machine according to claim 1, wherein the offset amount (S) is set as a position of the crosshead (12). 3. A setting for setting an offset amount (S) of a toggle link mechanism (13) by a mold clamping selection device (30) of a toggle type mold clamping device that expands and contracts a toggle link mechanism (13) by a motor (18). Control device (2) having a device (27)
5), a driver amplifier (26) for driving the motor (18) by a command signal from the control device (25), and a pulse encoder (24) for detecting an offset amount (S) by the rotation speed of the motor (18). And a mold clamping selection device for a toggle type mold clamping device of an injection molding machine, characterized in that the mold clamping state is maintained at a predetermined offset amount (S). 4. The mold clamping selection device of the toggle type mold clamping selection device of an injection molding machine according to claim 3, wherein the offset amount (S) is set as a position of the crosshead (12).