JPH0434928B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a mold contact position setting method and device for a mold clamping device.

(B) Prior Art In the mold clamping device of an injection molding machine, it is necessary to adjust the mold clamping device so that a predetermined mold clamping force can be obtained when a mold is replaced. When the mold clamping device is adjusted, the position of the movable platen when the fixed mold and movable mold come into contact also changes, so it is necessary to newly set the mold contact position (so-called mold touch position).
After contact with the mold, the process moves to the mold clamping process, in which a large mold clamping force is applied to the mold. Conventionally, limit switches have been used to detect the contact position of the mold. That is, the limit switch is actuated by a cam attached to the movable platen or the crosshead of the toggle mechanism so that its position can be adjusted, and the mold contact position is detected by adjusting the position of the cam. This cam adjustment work was carried out by an operator while checking the contact state of the mold.

(c) Problems to be solved by the invention However, in the conventional mold contact position setting method of the mold clamping device as described above, variations occur in the operating position of the limit switch depending on how the operator performs adjustment work. In addition, since it was necessary to adjust the position of the cam, it was not possible to set the mold contact position by remote control. The present invention aims to solve these problems.

(d) Means for solving the problem The present invention solves the above problem by moving the movable plate forward to set the mold contact position and setting the position where the moving speed of the movable plate becomes 0 as the mold contact position. Solve problems. That is, in the method for setting the mold contact position of the mold clamping device according to the present invention, after adjusting the mold clamping device so as to obtain a predetermined mold clamping force, the movable platen is moved from the mold open state to the fixed platen side using slight force. Detecting the moving speed of the movable plate or a member that moves in a predetermined relationship with the movable plate while moving it forward, and storing the position of the movable plate or the member that moves in a predetermined relationship with the movable plate when the moving speed becomes 0; This memorized position is set as the mold contact position at which the mold clamping process is started. The mold contact position setting device according to the present invention also includes a position detection device (pulse generator 54 and computing unit 60) that detects the position of the movable platen 16 or a member (for example, the crosshead 36) that moves in a predetermined relationship with the movable platen 16. and a speed detection device (pulse generator 54 and differentiator 6
2), a determiner 64 that determines that the speed detected by the speed detection device has become 0, and a signal from the position detection device at the time when the determiner determines that the speed has become 0. A controller 66 that stores the mold contact position in the memory 70 to start the mold clamping process.
It has . Incidentally, Katsuko indicates corresponding members in the embodiments described later.

(E) Action After the mold clamping force has been adjusted, the movable platen is moved forward with a slight force. The moving speed of the movable platen or a member that moves in a predetermined relationship with the movable platen is detected, and the position of the movable platen or the member that moves in a predetermined relationship with the mold at the time when the mold comes into contact and the moving speed becomes 0. It is stored as a contact position. In the subsequent molding operation, the mold clamping process is started when the movable platen or a member moving in a predetermined relationship therewith reaches a memorized position.

(f) Embodiment FIG. 2 shows a toggle type mold clamping device to which the present invention is applied. The fixed platen 10 and the housing 12 are connected by four tie bars 14 and nuts 15 and 17, and a movable platen 16 is movably supported by the tie bars 14. A fixed die 18 is attached to the fixed platen 10, and a movable die 20 is attached to the movable platen 16. The movable platen 16 is connected to a male threaded member 22 via a toggle mechanism 24. Toggle mechanism 2
The long link 26, the short link 28, and the cross link 30 that make up the main body 4 are connected to each other by a pin 32, and the cross head 36, which is integral with the male thread member 22, the housing 12, and the movable platen 16, are connected to each other by a pin 38, 40 and 42. The male threaded member 22 meshes with the female threaded member 44 to constitute a ball screw mechanism. The female threaded member 44 is rotatably supported by the housing 12, but is restrained from moving in the axial direction. A pulley 46 is provided on the female threaded member 44 so as to rotate together therewith, and this pulley 46 is connected to another pulley 48 via a belt 47. The pulley 48 is rotatably driven by an electric motor 50 attached to the housing 12 via a bracket 49. Electric motor 50 has a pulse generator 54 .

Next, a method for setting the mold contact position will be explained.

First, the mold clamping device is adjusted as follows so as to obtain a predetermined mold clamping force. By rotating the nut 17, the housing 12 is moved, and the movable mold 20 is brought into contact with the fixed frame 18 with the toggle mechanism 24 fully extended. Next, the toggle mechanism 24 is reduced, and the movable platen 16 and the movable mold 2
0 is moved backward, and then the nut 17 is rotated to move the housing 12 by a predetermined amount toward the fixed platen 10. The mold clamping force is determined by the amount of movement of the housing 12. Next, operate the electric motor 50,
Move the crosshead 36 forward. The driving force of the electric motor 50 at this time is kept very small. While the crosshead 36 is moving forward, the position of the crosshead 36 is detected by the pulse generator 54, and the detected value of the pulse generator 54 is inputted to a calculator 60 as shown in FIG. 1 to be used as a position signal. At the same time, the detected value of the pulse generator 54 is also input to the differentiator 62, where it is differentiated and converted into a speed signal. The speed signal from the differentiator 62 is sent to the determiner 64
The determiner 64 outputs a signal to the controller 66 when the speed signal becomes zero. The speed signal becomes 0 when the movable platen 16 moves forward and the movable mold 20 contacts the fixed frame 18. When the mold contacts and the determiner 64 outputs a signal to the control panel 66, the position signal inputted from the calculator 60 at that time is stored in the memory 70 of the injection machine control device 68. In the subsequent control by the injection machine control device 68, the position signal stored in the memory 70 is used as a signal for starting the mold clamping process when the mold closing process is completed. Note that the mold thickness changes due to a change in mold temperature, and as a result, the mold contact position also changes, albeit slightly. In order to calibrate the position signal to be stored in the memory 70 according to the change in the mold contact position, the mold contact position as described above can be set for each shot, every predetermined number of shots, or at any arbitrary time interval. All you have to do is to do it. In addition, in order to prevent the mold clamping process start signal from not being output even though the molds are actually in contact due to the change in mold thickness as described above, the initial memory value is changed. A certain width may be given. For example, if the initial memory value is 100mm, ±1mm
If the allowable value is set at 99 to 101 mm, a signal to proceed to the mold clamping process will be output even if the mold contact position changes.

Although this embodiment has been described with respect to a toggle type mold clamping device, the present invention can be similarly applied to a direct pressure type mold clamping device. In addition, it is also applicable to mold clamping devices other than the above-mentioned toggle type mold clamping devices, such as mold clamping devices that use a linear motor to move the crosshead back and forth, and mold clamping devices that use a hydraulic cylinder to move the crosshead back and forth. The invention is applicable. Further, in the above embodiment, the position of the crosshead 36 that moves in a predetermined relationship with the movable platen 16 is detected by the pulse generator 54, but the position of the crosshead 36 or the position of the movable platen 16 is Direct detection using an encoder or the like may also be used. Further, in this embodiment, the pulse generator 54 and the differentiator 62 are used to detect zero speed, but a speed detector is provided on the movable platen 16 or the crosshead 36 to directly detect the speed. Good too.

(g) Effects of the Invention As explained above, according to the present invention, the speed of the movable platen or a member moving in a predetermined relationship with the movable platen is detected, and the position when this becomes 0 is determined as the mold contact position. This prevents the mold contact position from changing due to variations in adjustment work by the operator, and improves productivity because the mold contact position can be determined by electrical remote control. do. Furthermore, even if the mold contact position changes due to changes in mold temperature, etc., calibration can be easily performed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a toggle type mold clamping device to which the present invention is applied. 10... Fixed plate, 16... Movable plate, 24... Toggle mechanism, 50... Electric motor, 54... Pulse generator, 60... Arithmetic unit, 62... Differentiator, 64...
Judgment device, 66...controller, 68...injection machine control device, 70...memory device.

Claims (1)

[Claims] 1. After adjusting the mold clamping device so as to obtain a predetermined mold clamping force, the movable platen is advanced from the mold open state to the fixed platen side using a slight force, and the movable platen or the predetermined clamping force is moved forward from the mold open state toward the fixed platen. Detect the moving speed of the member that moves in relation to the relationship, store the position of the movable plate or the member that moves in a predetermined relationship with this when this moving speed becomes 0, and use this memorized position in the mold clamping process. A method for setting a mold contact position of a mold clamping device, characterized in that the mold contact position is set as a starting mold contact position. 2. A position detection device that detects the position of the movable platen or a member that moves in a predetermined relationship with it; a speed detection device that detects the moving speed of the movable platen or a member that moves in a predetermined relationship with it; A determiner determines that the detected speed has become 0, and a mold contact position that starts the mold clamping process by transmitting a signal from the position detection device at the time when the determiner determines that the speed has become 0. A mold contact position setting device for a mold clamping device, comprising: a controller for storing information in a memory as a controller;