JPH0478091B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a rubber extrusion device, a control device for controlling the drive of the rubber injection device and the clamping of a mold,
This article relates to a rubber injection molding device suitable for multi-product production.

[Prior Art] Conventionally, rubber injection molding equipment includes a mold clamping device that clamps and opens a mold consisting of a fixed mold and a movable mold, a rubber extrusion device that has an extrusion screw that plasticizes rubber, An apparatus has been developed that includes a rubber injection device having an injection plunger for injecting plasticized rubber from the rubber extrusion device into the cavity of a mold.

This rubber injection molding apparatus uses an injection plunger to inject rubber plasticized by a rubber extrusion device into the cavity of a molding die, and has various advantages in terms of productivity, reduction in defect rate, and the like.

[Problem that the invention seeks to solve]

Automatic control is desirable in order to enhance the above advantages, but unlike resin molding, rubber molding has a viscosity that varies greatly depending on the rubber used, so it is difficult to control the filling of the injection cylinder chamber and the mold cavity. It is not easy to improve the accuracy of resin filling, and there are also problems such as rubber burning, so automatic resin control technology cannot be applied as is.

The present invention was made in view of the above-mentioned circumstances, and controls the drive of the rubber extrusion device, the rubber injection device, and the mold clamping device while suppressing problems such as rubber burning and viscosity, thereby improving molding. An object of the present invention is to provide a rubber injection molding device suitable for multi-product production where types are frequently changed.

[Means for solving problems]

The rubber injection molding apparatus according to the present invention includes a drive section that moves the movable mold of a mold having a fixed mold and a movable mold to close and open the mold, and a first hydraulic control that controls the hydraulic pressure for driving the drive section. a mold clamping device having a part, an extrusion screw for plasticizing and extruding rubber, and a second hydraulic control part for controlling hydraulic pressure for rotationally driving the extrusion screw; a cylindrical cylinder having a shaft hole-like chamber into which rubber is supplied;
An injection device that has a plunger portion with an outer diameter that corresponds equally to the inner diameter of the cylinder that forms the chamber, is inserted into the chamber of the cylinder so that it can move along its axis, and injects the rubber inside the chamber into the cavity of the mold. A rubber injection device having a plunger, a third hydraulic control section for controlling hydraulic pressure for driving the injection plunger, a resistor disposed parallel to the axis of the cylinder and extending in the direction of movement of the injection plunger, and a resistor for the injection plunger. A plunger position detector that detects the position of the injection plunger in the cylinder, which consists of a brush that is connected and slides into contact with a resistor as the injection plunger moves; A mold position detector that detects the position of the movable mold of the mold clamping device. , Based on the detection signal of the plunger position detector, the second hydraulic control section is controlled to control the rotational speed of the extrusion screw, and the third hydraulic control section is controlled to control the injection speed of the injection plunger, and the mold position is controlled. The present invention is characterized by comprising a control device that controls the first hydraulic control section to control the moving speed of the movable type based on the detection signal of the detector.

The mold clamping device has a drive section and a first hydraulic control section. The drive unit moves the movable mold of the mold having a fixed mold and a movable mold to close and open the mold. The first hydraulic control section controls the hydraulic pressure for driving the drive section, and can be formed by a hydraulic control valve.

The rubber extrusion device has an extrusion screw and a second hydraulic control section. An extrusion screw plasticizes rubber and extrudes it. The second hydraulic control section controls the hydraulic pressure for rotationally driving the extrusion screw, and can be formed by a hydraulic control valve.

The rubber injection device includes a cylinder with a chamber, an injection plunger, and a third hydraulic control section. The chamber is a space into which plasticized rubber is supplied from the rubber extrusion device. The injection plunger injects the rubber inside the chamber into the cavity of the mold. The third hydraulic control section controls the hydraulic pressure for driving the injection plunger, and can be formed by a hydraulic control valve.

The plunger position detector detects the current position of the injection plunger within the cylinder. The mold position detector directly or indirectly detects the current position of the movable mold of the mold clamping device.

The control device, depending on the plunger position detector,
In other words, depending on the current position of the injection plunger, the second
The hydraulic control unit is controlled to control the rotational speed of the extrusion screw, and the third hydraulic control unit is controlled to control the injection speed of the injection plunger, and in response to the detection signal of the mold position detector, the movable The first hydraulic control section is controlled according to the current position of the mold to control the moving speed of the movable mold, that is, the mold closing speed and the mold opening speed.

The control device can be formed by a programmable sequence controller (hereinafter also referred to as a PC) or a microcomputer (CPU) that has a memory function and can store and execute control information as a program.
Further, in consideration of cost etc., it can also be formed by a combination of a programmable controller and an analog control device.

For example, the control device can be formed by an analog control device and a programmable controller having an input section, a control section, a memory section and an output section.

Rather than forming the control unit by a combination of a programmable controller and an analog control device,
If it is formed using only a programmable control (PC), it can be done as follows. That is, a setting signal that sets the rotation speed of the extrusion screw is input to the input section of the programmable control (PC), and a setting signal that sets the moving speed of the movable mold at a plurality of predetermined positions is input. , a setting signal that sets the injection speed of the injection plunger to a plurality of predetermined values is input. The memory part of the PC is
A predetermined value corresponding to a setting signal input to the input section is stored. The control section of the PC outputs an electric signal corresponding to a predetermined value of the memory section in response to detection signals from the mold position detector and the plunger position detector.
The output section of the PC outputs signals to the first hydraulic control section, the second hydraulic control section and the third hydraulic control section in accordance with the electric signals from the control section of the PC.
Output to hydraulic control section.

For example, when a control device is formed by combining an analog control device and a PC, as in the embodiment described later, a large number of digital potentiometers are provided in the analog control device, and each digital potentiometer is The setting device holds multiple settings for the rotational speed of the extrusion screw, multiple settings for the injection speed of the injection plunger, and multiple settings for the moving speed of the movable mold as predetermined voltage values for the digital potentiometer. You may decide to do so. When using a digital potentiometer, various values can be held by setting with a setting device.

Incidentally, the plurality of predetermined values are appropriately set depending on the rubber material used, the type of cavity of the mold, and the like.

When the plunger position detector detects the position of the injection plunger in a state immediately before filling the chamber with rubber to be injected into the chamber, the control device controls the hydraulic pressure of the second hydraulic control unit in accordance with the detection signal of the plunger position detector. Preferably, the rotation speed of the extrusion screw is reduced. In this way, even if the rubber has a high viscosity unlike resin, the accuracy of the amount of rubber filled into the chamber can be improved, and since the amount of rubber filled is accurate, it is possible to suppress burrs and reduce the defective rate of rubber products. It's advantageous.

〔Example〕

(Configuration of Example) The rubber injection molding apparatus according to the present example includes a mold clamping device 1, a rubber extrusion device 2, a rubber injection device 3,
A plunger position detector 4 and a mold position detector 5,
It consists of a control device 6.

The mold clamping device 1 has a drive section 10 and first hydraulic control valves 11 and 17 as a first hydraulic control section. The drive unit 10 includes a boost cylinder 100 and a main ram 10
Consists of 1. Boost cylinder 100 consists of cylinder 100a and piston 100b. The main ram 101 includes a housing 101a and a movable plate 10.
1c and a ram 101b. main ram 10
A guide 12 is arranged at 1. The pressurizing pressure of the main ram 101 is detected by the pickup 15, and the detection signal is input to the analog control device 64 through a lead wire 150.

The mold 7 includes a movable mold 70, a medium mold 71, and a sprue 7.
2a, and a cavity is formed in the cut surface. The movable mold 70 is the movable plate 1
01c, and can freely move up and down along the guide 12. When the movable mold 70 moves up and down, the middle mold 71 also moves up and down accordingly. In the initial state shown in FIG. 1, the middle die 71 is received by a stopper portion (not shown) of the guide 12, and is in a so-called floating type.

The first hydraulic control valve 11 controls the hydraulic pressure for driving the boost cylinder 100 of the drive section 10 , and the first hydraulic control valve 17 controls the hydraulic pressure for driving the boost cylinder 100 of the drive section 10 .
This is to control the oil pressure that drives 01. 1st
Hydraulic control valve 11 is connected to boost cylinder 100 via piping 110-113. The second hydraulic control valve 17 is connected to the main ram 101 via pipes 114 and 115.

The rubber extrusion device 2 includes an extrusion screw 20 that plasticizes and extrudes rubber, and a second extrusion screw that controls oil pressure that rotationally drives a shaft 20a of the extrusion screw 20.
It consists of a second hydraulic control valve 21 and an oil motor 22 as a hydraulic control section. The oil motor 22 rotates the shaft 20a of the extrusion screw 20. The oil motor 22 and the second hydraulic control valve 21 are connected to the piping 22
0,221.

The rubber injection device 3 includes a cylinder 31 having a chamber 30, an injection plunger 32 built into the cylinder 31, and a third hydraulic control valve 33 as a third hydraulic control section. As shown in FIG. 1, the injection plunger 32 includes a plunger portion 32a provided at the tip and having an outer diameter equivalent to the inner diameter of the chamber 30 of the cylinder 31, and a plunger portion 32a connected to the plunger portion 32a and parallel to the axis P1 of the cylinder 31. It consists of a plunger rod portion 32b with a large diameter, and a large diameter rod portion 32c connected to the plunger rod portion 32b and parallel to the axis P1 of the cylinder 31. The outer diameter of the large diameter rod portion 32c corresponds equally to the inner diameter of the inner flange portion 31r of the cylinder 31. In addition, in Fig. 3, the injection plunger 3
2 is written in abbreviated form. The chamber 30 is a space into which plasticized rubber is supplied from the rubber extrusion device 2. The third hydraulic pressure control valve 33 controls the hydraulic pressure for driving the injection plunger 32 forward and backward two times. The nozzle 34 of the rubber injection device 3 is applied to the sprue 72a of the fixed mold 72. The third hydraulic control valve 33 and the cylinder 31 are connected via pipes 330 and 331.

The plunger position detector 4 is connected to the injection plunger 3
2 is a sensor that detects the current position of the rubber injection device 3, and is formed of a linear potentiometer. Consisting of The brush 41 slides on the resistor 40 as the injection plunger 32 advances and retreats. The terminals of the resistor 40 are lead wires 400, 40.
1,402 to the analog control device 64 of the control device 6. Therefore, the voltage signal as a detection signal of the plunger position detector 4 is outputted to the analog control device 6 as a voltage that changes in an analog manner.
4 is input.

The mold position detector 5 is a sensor that detects the current position of the movable plate 101c and, in turn, the movable mold 70, and is also formed of a linear potentiometer.
and a brush 51 held by the movable plate 101c. The resistor 50 has lead wires 500, 501,
Analog control device 6 of control device 6 via 502
Connected to 4. More specifically, it is connected to the comparator 640 (FIG. 5) of the analog control device 64, and the setting section 800 is connected to the comparator 640.
The comparator 640 outputs a voltage signal when the voltage of the resistor 50, which is changed by the brush 51, reaches the voltage set by the setting section 800.

As shown in FIG. 4, the control device 6 includes an analog control device 64 formed by combining an amplifier and a programmable controller (PC) 65, also called a sequencer. The programmable controller 65 includes an input section 60 and a memory section 61.
, a control section 62 , and an output section 63 . Input section 6
0 and the later-described setting panel 8 of the analog control device 64.
is connected to. Further, the output section 63 and a hydraulic device 9, which will be described later, are connected.

The analog control device 64 has an injection control circuit shown in FIG. 6 and a mold opening/closing control circuit shown in FIG. The injection control circuit shown in FIG. 6 has an amplifier 640, an amplifier 641, comparators 642 to 646,
Furthermore, it has resistors 650 to 665, and a capacitor 66.
6 and are connected as shown in Figure 6. Here, as is clear from FIG.
6 to match the voltage. The amplifier 641 converts the voltage of the setting section 858 for setting the charge amount to the comparator 6.
42 to 646 and setting section 8.
60, supplying voltage to the setting section 857; The comparator 642 compares the amplifier 640 and the amplifier 641 and determines whether the position of the brush 41 of the detector 4 is
When detecting that the position is above the position set in step 58, a signal indicating completion of rubber filling, that is, a signal indicating completion of charging, is outputted to the chamber 30. The comparator 643 compares the output voltage of the amplifier 1 and the output voltage of the amplifier 2, and outputs a deceleration point signal so as to turn on earlier than the comparator 642 by the voltage value of VRB. As a result, the rotational speed of the extrusion screw 20 is lowered just before the charging is completed, that is, just before the chamber 30 is filled, thereby making the charging amount accurate as will be described later. Comparators 644 and 65 compare the output voltage of amplifier 640 and the output voltage of amplifier 641. As a result of the comparison,
The comparator 644 outputs a signal of the injection switching point (1→2), and the comparator 645 outputs a signal of the injection switching point (2→3). Comparator 64
6 compares the output of the amplifier 640 with VRE, detects completion of injection and turns ON, thereby outputting a signal indicating completion of injection. In addition, comparators 644 and 645
The output forms a circuit using logic and is output to the programmable controller 65.

The mold opening/closing control circuit shown in FIG.
0, amplifier 681, comparators 682 to 691
It has resistors 700 to 719, and is connected as shown in FIG. The amplifier 680 matches the voltage of the mold position detector 5 formed by a mold clamping linear potentiometer with the comparators 682 to 691. The amplifier 681 has setting sections 800 to 80.
6, generates a voltage to be supplied to. Comparator 6
Reference numerals 82 to 685 are for controlling the rising speed, and the current position of the brush 51 of the mold position detector 5 formed by a linear potentiometer for mold clamping is determined by the setting section 80.
When it is above the position set from 0 to 803
Turn on. The comparators 686 to 690 are for controlling the descending speed, and the brush 51 of the mold position detector 5 is formed by a mold clamping linear potentiometer.
The current position of the setting section 804, 805, 806,
Turns ON when the position is below the position set in 803. Comparator 691 is used as an auxiliary signal. Note that all the signals are output to the outside and used as control signals for the programmable controller 65, which is a sequencer.

By the way, FIG. 2 shows a setting panel board 8 provided on the analog control device 64 of the control device 6. Here, the setting panel board 8 will be explained. The setting panel plate 8 consists of a mold clamping adjustment section 80 and an injection adjustment section 85. The mold clamping adjustment section 80 includes a setting section 800 that sets the starting point position of the low speed range of the rising speed of the movable plate 101c and the movable mold 70, and the movable mold 70.
A setting section 801 that sets the end point position of the low speed range of the rising speed of the movable mold 70, a setting section 802 that sets the starting point position of the low speed range of the rising speed of the movable mold 70, and a setting section 803 that sets the mold clamping position of the movable mold 70. Further, it has a setting section 804 for setting the end point position of the low speed range of the descending speed of the movable mold 70, a setting section 805 for setting the end point position of the high speed range of the descending speed of the movable mold 70, and a setting section 805 for setting the end point position of the high speed region of the descending speed of the movable mold 70; It has a setting section 806 that sets the starting point position of the low speed range.

The mold clamping adjustment section 80 also includes a setting section 807 for setting the pressurizing pressure, that is, a mold clamping force, a setting section 808 for setting the speed in the high speed range of the rising speed of the movable mold 70, and a setting section 808 for setting the speed in the high speed range of the descending speed of the movable mold 70. and a setting section 809 for setting the speed of.

On the other hand, the injection adjustment section 85 of the setting panel board 8 has a setting section 850 for setting the first stage injection speed, a setting section 851 for setting the second stage injection speed, and a setting section 852 for setting the third stage injection speed. , further includes a setting section 853 for setting the maximum injection pressure, a setting section 856 for setting the position of a switching point for switching between the first stage injection speed and the second stage injection speed, and the second stage injection speed and the third stage injection speed. It has a setting section 857 for setting the position of the switching point for switching between the stage injection speed and the stage injection speed, a setting section 854 for setting the magnitude of the holding pressure, and a setting section 85 for setting the rotational speed of the extrusion screw 20.
5 and the chamber 30 of the plunger position detector 4
and a setting section 858 for setting the amount to be filled into the container.

Here, setting sections 800 to 809, 850 to 85
7, 858 uses a digital potentiometer as shown in FIG.
You can change the numbers as appropriate by pressing .

Note that the number "600" set in the setting section 803 as described above indicates a mold clamping state in which the movable mold 70 and the middle mold 71 are in contact with the fixed mold 72. Therefore, although numbers less than "600" are displayed in the setting sections 800 to 806, this means that the mold is not in the clamped state.

In this example, the numbers to be set are Kg/cm ² and mm/se.
It is not an absolute value with a unit such as c, but a relative value expressed as a percentage of the maximum value. Also, setting panel board 8
A mode display section 81, a setting section 82, and a digital meter 83 are provided on the upper side. The mode display section 81 displays various modes No. 1 to No. 7. In the setting section 82, the upper switch 8
20. You can display the mode number by pressing the lower switch 821 as appropriate.

A hydraulic device 9 is connected to the rubber injection molding apparatus according to this embodiment, as shown in FIG. 3. The hydraulic system 9 includes a motor 90 and piping 90a and 90b.
a swash plate type hydraulic pump 91 (driven by a motor 90) that adjusts the pump flow rate by the swash plate angle;
Hydraulic control valve 9 connected by piping 90c and 90d
2, a hydraulic control valve 93, a sensor 95 that detects the pressure of the pump 91 as a voltage signal and inputs the detection signal from a terminal J to the sequence controller 65 of the control device 6, and a swash plate angle with respect to the axis of the pump 91, that is, the pump 1. detects the discharge amount and sends a detection signal from the terminal m to the sequence controller 6 of the control device 6.
5 (the discharge amount of the pump 91 is proportional to the swash plate angle with respect to the axis of the pump 91, so the sensor 95 functions as a flow rate detection sensor)
, a computing unit 97 , and an oil tank 98 .
(The diagram near hydraulic controls 92 and 93 in Fig. 3 is the JIS hydraulic diagram symbol for proportional electromagnetic pressure and flow rate control type.) (Function of the embodiment) Now, use of the rubber injection device according to the present embodiment. Explain how. In this case, the damper pulley is formed as a rubber product.

(1) Setting of predetermined values First, molding conditions are set on the setting panel board 8. That is, using FIG. 2 as an example, when the movable mold 70 is at the lowest point as in the initial state shown in FIG. 1, it is 0, and when the movable mold 70 is clamped, it is 600. Therefore, 600 is set in the setting section 803. Then, the setting section 800 is set to 123 as the starting position of the low speed range of the rising speed of the movable mold 70, and the setting section 800
1, the end position of the low speed range of the movable mold 70 is set to 230, and the start position of the low speed range of the rising speed of the movable mold 70 is set to 500 in the setting section 802.

Similarly, as shown in FIG. 2, the end position of the low speed range of the descending speed of the movable mold 70 is set to 550 in the setting section 804, and the end position of the high speed region of the descending speed of the movable mold 70 is set to 200 in the setting section 805. and set it in the setting section 806.
, the starting position of the lowering speed of the movable mold 70 is set to 100.

Furthermore, the pressurizing force is set to 25 in the setting unit 807, the rising speed of the movable mold 70 is set to 70 in the setting unit 808,
The lowering speed of the movable mold 70 is set to 90 in the setting unit 809.

Similarly, as shown in FIG.
7, the injection speed switching positions are set to 65 and 40, the first stage injection speed is set to 50 in the setting part 850, the second stage injection speed is set to 40 in the setting part 851, and the second stage injection speed is set to 40 in the setting part 852. Set the third stage injection speed to 15.

Similarly, the rotational speed of the extrusion screw 20 is set to 20 in the setting part 855, the holding pressure is set to 80 in the setting part 854, and the amount of filling into the chamber 30 of the rubber injection device 3 is set in the setting part 858. .

All of the various setting data set on the setting panel board 8 of the analog control device 64 described above are held as the voltage values of the digital potentiometers described above.

(2) Mold clamping process The control section 62 of the PC 65 of the control device 6 sends an operation command to the first hydraulic control valve 1 via the output section 63.
1, 17, outputs to the second hydraulic control valve 21 and the third hydraulic control valve 33, operates the first hydraulic control valve 11 to generate hydraulic pressure to drive the boost cylinder 100 of the drive unit 10, and connects the hydraulic pressure to the piping. 113,11
2 to move the piston 100b of the boost cylinder 100 upward.

Then, the movable plate 101c rises along the guide 12 at a rising speed of 70 (displayed in the setting section 808) in the high speed range. At this time, the movable mold 70 rises at a high speed of 70 (setting section 808) in the high speed range up to the height position corresponding to "123". In this case, the control device 6
The control unit 62 of the PC 65 inputs the pressure command signal VK to the calculator 97 while keeping it at a constant voltage, and also inputs the speed command signal VL1 corresponding to the high speed range to the calculator 97 from the terminal.

The computing unit 97 compares the detection signals from the sensors 96 and 95 and gives the results as control signals to the hydraulic control valves 92 and 93, thereby adjusting the swash plate angle of the hydraulic pump 91 and controlling the hydraulic pump 91. Controls discharge pressure and discharge flow rate.

When the movable plate 70 reaches a height position corresponding to 123 (set by the setting machine 800), the movable plate 70
The movable mold 70 slowly hits the medium mold 71 and presses the medium mold 71.
It rises with 1. And, the movable type 70 is
It rises at low speed to a height equivalent to 230.
That is, if the movable mold 70 hits the medium mold 71 at high speed, there is a risk of damage, so in order to prevent this, "123"
- ``230'', it is raised at low speed. In this case, the PC 65 of the control device 6 outputs a pressure command signal.
While keeping VK at a constant voltage, the speed command signal VL2 corresponding to the low speed range (speed command signal VL2 is the speed command signal
(lower voltage than VL1) is input to the arithmetic unit 97 from the terminal.

Further, between "230" and "500", the movable mold 70 rises at a rising speed in a high speed range. In this case, the PC 65 of the control device 6 inputs the corresponding speed command signal VL in the high speed range to the calculator 97 from the terminal while keeping the pressure command signal VK at a constant voltage. Arithmetic unit 97
compares the detection signals from the sensors 96 and 95 as described above, and sends the results to the hydraulic control valve 92.
and 93 as a control signal, thereby adjusting the swash plate angle of the hydraulic pump 91.
Controls the discharge pressure and discharge flow rate.

When the movable mold 70 reaches the position corresponding to "500", the PC 65 of the control device 6 inputs the speed command signal VL2 in the low speed range while keeping the pressure command signal VK at a constant voltage, and therefore the movable mold 70 begins to rise at a rising speed in a low speed range and hits the fixed type 72. That is, just before the movable die 70 and the middle die 71 hit the fixed die 72, the movable die 70 is raised at a low speed to prevent damage to the die. Therefore, while increasing the mold clamping speed and improving productivity, the fixed mold 72, the medium mold 71,
Damage to the movable mold 70 can be prevented.

When the movable mold 70 hits the fixed mold 72 as described above, a signal from the control section 6 is input to the first hydraulic control valve 17, which operates and causes the main ram 101 of the drive section 10 to
Apply hydraulic pressure to. Main ram 101 of this drive unit 10
The hydraulic pressure applied to is set in the setting section 807.
The pressure is equivalent to 25. The pressure is sensed by a pressure pickup 15 and input as a voltage signal to an analog control device 64 of the control device 6. Then, it compares the set pressure (responsible to 25) and the actually applied pressure, and if they are different, sends a signal to the first hydraulic control valve 17 and operates the first hydraulic control valve 17 to control the main ram. A predetermined pressure is applied to 101.

(3) Filling process By the way, in this example, prior to the mold clamping process described above, the extrusion screw 20 of the rubber extrusion device 2 is driven (at a rotational speed of 20 set with a set value of 855) to plasticize the rubber. . Then, the plasticized rubber is injected into the chamber 30 using an extrusion screw 20. At this time, as the rubber is injected into the chamber 30, the injection plunger 32 rises, and therefore the brush 41 of the mold position detector 4 also rises. Therefore, the current position of the injection plunger 32 is detected by the plunger position detector 4 as a voltage signal that changes in an analog manner, and the detection signal is sent to the analog control device 64 of the control device 6 via the lead wire 40.
2. The input voltage signal and
When the voltage value set by the setting device 858 matches, the control unit 6 detects whether the chamber 30 is filled, that is, whether charging is completed.

In this embodiment, when the plunger position detector 4 detects the position of the injection plunger 32 immediately before filling the chamber 30 with rubber, the control device 6 The second hydraulic control unit 2 according to the detection signal
The rotational speed of the extrusion screw 20 is reduced by controlling the oil pressure of the extruder 1. This is done in order to improve the accuracy of the amount of rubber filled into the chamber 30. Then, when the voltage set by the setting section 858 and the voltage of the plunger position detector 4 match as described above, the rotation of the extrusion screw 20 is stopped and the filling process is completed.

(4) Injection process When the chamber 30 is filled with rubber and charging is completed as described above, the PC 65 of the control device 6
The control unit 62 operates the third hydraulic control valve 33 to first inject at a speed corresponding to an injection speed of 50 (set by the setting unit 850), and then inject at positions 1 to 2.
(set in the setting section 856), injection is performed at a speed equivalent to injection speed 40 (set in the setting section 851), and between positions 2 and 3 (set in the setting section 857), injection is performed at a speed equivalent to 15 (set in the setting section 857). 852)). In other words, the injection speed is switched to three stages, "50", "40", and "15", depending on the current height position of the injection plunger 32, and the speed is fast at the beginning of injection and slows down as the injection process approaches the end. Shoot at speed. The reason for injecting at a slower speed as the injection process approaches the end is because injection speed and injection pressure are inversely proportional.
This is to increase the injection pressure near the end and apply holding pressure to the rubber injected into the mold 7, thereby preventing the amount of filling into the cavity of the mold 7.

When the injection speed is just before the completion of injection, the injection speed decreases as described above, so the pressure is held at a pressure equivalent to the holding pressure "80" (set by the setting unit 854) and the time set in the control device 6 is maintained. , continue the pressure holding process.

(5) Vulcanization process After completion of pressure retention, perform the vulcanization process for a specified period of time. During vulcanization, the extrusion screw 20 of the rubber extrusion device 2
The chamber 30 is rotated to plasticize the rubber, and the chamber 30 is filled with the plasticized rubber and charged in advance in the same manner as described above.

(6) Mold opening process When the above-mentioned vulcanization process is completed, the control device 6
outputs a signal to the first hydraulic control valve 17 to close the pipe 1.
Open the check valve 114a at a pilot pressure of 15,
Then, a signal is output to the first hydraulic control valve 11, and the piston 110b of the boost cylinder 100 is driven downward to lower the movable plate 101c to open the mold. Specifically, at the position corresponding to "600" to "500", the vehicle is lowered at a descending speed in the low speed range. Then, from "600" to the position corresponding to "550" to "200", the descending speed in the high speed range (setting machine 80
Descend at a speed corresponding to "90" set in step 9). Furthermore, the fixed mold 72 and the medium mold 7 are lowered to the positions corresponding to "100" to "0" at a low descending speed, thereby increasing the mold opening speed as much as possible.
1. Prevent damage to the movable mold 70 as much as possible.

(Effects of Example) Now, when changing the rubber product to be molded, it is necessary to change the mold 7 to a mold for molding another type of rubber product. In this case, the control device 6
The settings are made by appropriately changing the numbers in the setting sections 800 to 809 and setting sections 850 to 858 of the setting panel board 8 of the analog control device 64. In this way, the molding conditions can be molded based on the set data, and therefore there is no problem even when the mold is changed, and it is suitable for producing a wide variety of rubber products in small quantities.

In this embodiment, the plunger position detector 4 includes a long resistor 40 and a brush 41, so that no matter what position the plunger portion 32a of the injection plunger 32 is in between the forward end and the backward end of the injection plunger 32. , the position of the injection plunger 32 can be detected, and complex control can be handled. Furthermore, the resistor 40 is disposed parallel to the axis P1 of the cylinder 31, and the injection plunger 32 advances and retreats parallel to the axis P1 of the cylinder 31, so the brush 41 connected to the injection plunger 32 also moves in parallel with the axis P1 of the cylinder 31. 31
The brush 4 moves parallel to the axis P1 of the brush 4.
The parallelism between the movement locus of No. 1 and the resistor 40 is maintained extremely well. Therefore, it is advantageous to prevent abnormal wear of the brush 41 and uneven wear of the resistor 40 in the longitudinal direction.

In this embodiment, since the injection speed by the injection plunger 30 is divided into three stages by the setting parts 850, 851, and 852, the injection speed can be reduced as the injection progresses into the cavity of the mold 7. In this case, since the injection speed and the injection pressure are in an inversely proportional relationship, the injection pressure can be increased as the cavity of the mold 7 is filled. Therefore, it is advantageous to maintain the pressure of the rubber filled in the cavity of the mold 7, and when filling the mold 7,
This is advantageous in preventing defects such as cavities due to unfilling.

In this embodiment, the injection plunger 3 of the chamber 30 is positioned just before the mold 7 is filled into the cavity.
The extrusion screw 2 is set in advance as the height position of the extrusion screw 2 by the control device 6 when the set value is reached.
If the rotational drive speed of 0 is reduced or stopped, the accuracy of the amount of unvulcanized plasticized rubber filled into the chamber 30 can be improved, which is advantageous in terms of suppressing burrs in rubber products. .

In this embodiment, immediately before the movable die 70 hits the middle die 71 and immediately before the middle die 71 hits the fixed die 72,
In order to prevent mold damage, the movable mold 70 is raised at a low speed range, and otherwise raised at a high speed range. Therefore, damage to the fixed mold 72, the intermediate mold 71, and the movable mold 70 can be prevented while increasing the mold clamping speed and improving productivity.

〔Effect of the invention〕

As explained above, according to the rubber injection molding apparatus according to the present invention, the control device transmits the control signal to the first hydraulic control section, the second hydraulic pressure control section, and the second hydraulic pressure control section according to the detection signals of the mold position detector and the plunger position detector. It is configured to output to the control section and the third hydraulic control section.

Therefore, according to the rubber injection molding apparatus according to the present invention, the rotational speed of the extrusion screw, the moving speed of the movable mold, and the injection speed of the injection plunger can be changed as appropriate depending on the type of rubber product. Therefore, it is advantageous in reducing the defective rate of rubber products.

In the device of the present invention, since the plunger position detector consists of a long resistor and a brush, the position of the injection plunger can be detected regardless of the position of the injection plunger between the forward end and the backward end of the injection plunger. , can handle complex control. Furthermore, the resistor is arranged parallel to the axis of the cylinder, and the injection plunger moves forward and backward parallel to the axis of the cylinder, so the brush connected to the injection plunger also moves parallel to the axis of the cylinder. . Thereby, the parallelism between the brush movement locus and the resistor is maintained well between the forward end and the backward end of the injection plunger. Therefore, abnormal wear of the brush,
This is advantageous in preventing uneven wear in the length direction of the resistor, and can extend the life of the plunger position detector.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a schematic longitudinal sectional side view of a rubber injection molding apparatus according to the present embodiment, and FIG. 2 shows a setting panel plate of an analog control device of a control device. FIG. 3 is an explanatory diagram showing the relationship between the rubber injection molding apparatus and the hydraulic system according to the present embodiment, and FIG. 4 is a block diagram of the control device. FIG. 5 is an electrical wiring diagram near the mold position detector. FIG. 6 is an electric circuit diagram for injection control in the vicinity of the plunger position detector. FIG. 7 is an electrical circuit diagram for opening and closing the mold in the vicinity of the mold position detector. In the figure, 1 is a mold clamping device, 10 is a drive unit, 11 and 17 are first hydraulic control valves (first hydraulic control unit), 2
20 is a rubber extrusion device, 20 is an extrusion screw, 21 is a second hydraulic control valve (second hydraulic control section), 22 is an oil motor, 3 is a rubber injection device, 30 is a chamber, 31 is a housing, 32 is an injection plunger,
33 is a third hydraulic control valve (third hydraulic control section), 4 is a plunger position detector, 5 is a mold position detector, 6 is a control device, 60 is an input section, 61 is a memory section, 62
63 is a control section, 63 is an output section, 644 is an analog control device, 65 is a programmable controller, 7 is a molding mold, 70 is a movable mold, 72 is a fixed mold, 8 is a setting panel board, and 9 is a hydraulic system.

Claims (1)

[Scope of Claims] 1. A driving section that moves the movable mold of a mold having a fixed mold and a movable mold to close and open the mold, and a first hydraulic control section that controls hydraulic pressure for driving the driving section. a mold clamping device having a mold clamping device; an extrusion screw that plasticizes and extrudes rubber; a second hydraulic control unit that controls hydraulic pressure to rotationally drive the extrusion screw; and a rubber extrusion device that plasticizes and extrudes rubber. It has a cylindrical cylinder having a shaft hole-like chamber into which rubber is supplied, and a plunger portion having an outer diameter corresponding to the inner diameter of the cylinder forming the chamber, A rubber injection device having an injection plunger that is movably inserted along the axis and injects the rubber in the chamber into the cavity of the mold, and a third hydraulic control section that controls hydraulic pressure for driving the injection plunger. a resistor disposed parallel to the axis of the cylinder and extending in the direction of movement of the injection plunger; and a brush connected to the injection plunger and slidingly contacted with the resistor as the injection plunger moves; a plunger position detector that detects the position of the injection plunger in the cylinder; a mold position detector that detects the position of the movable mold of the mold clamping device; based on the detection signal of the plunger position detector,
controlling a second hydraulic control section to control the rotational speed of the extrusion screw and controlling a third hydraulic control section to control the injection speed of the injection plunger, based on the detection signal of the mold position detector; A rubber injection molding apparatus comprising: a control device that controls a first hydraulic control section to control the moving speed of the movable mold. 2. When the plunger position detector detects the position of the injection plunger immediately before filling the chamber with rubber to be injected into the chamber, the control device controls the hydraulic pressure of the second hydraulic control section based on the detection signal of the plunger position detector. The rubber injection molding apparatus according to claim 1, wherein the rotational speed of the extrusion screw is reduced.