JPH01221217A - Mold thickness control device of toggle type mold clamping device - Google Patents

Abstract

PURPOSE:To enable the control of a mold thickness simply, in a short period of time and precisely by setting up into specified mold thickness dimensions fully automatically, by applying a set up value fixed by measuring the mold thickness dimensions beforehand to a mold thickness setting part. CONSTITUTION:A hydraulic motor 11 is turned through the control of a mold thickness control device 13 and supporting board 3 is moved to an axial direction of a tie bar 4. A present value holding circuit calculates movement of the supporting board 3 with a pulse signal sending away through a pulse sensor 15 at the time when the supporting board 3 is shifted. The movement is added to or deducted from the present value held already and its value is held again. Then the present value held by the present value holding circuit is compared with a set up value of a mold thickness dimensions fixed through measurement beforehand and set up to a mold thickness setting part. When the supporting board 3 attains to a state of (set value + allowable dimensions) >= present value >= (set value - allowable dimensions) by moving the supporting board 3, control of the mold thickness is completed. Then setting to the fixed mold thickness dimensions can be performed wholly automatically by actuating the mold thickness control device 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mold thickness adjusting device for a toggle type mold clamping device that automatically sets a mold thickness dimension that generates a predetermined mold clamping force.

[Prior Art] Generally, in a toggle type mold clamping device, a plurality of tie bars are passed between a fixed plate fixed on a base and a support plate movably supported on the base. The movable plate is movably supported while being guided by tie bars, and is driven to move by a toggle link that expands and contracts with the support plate as a fulcrum. When setting the mold thickness and mold clamping force, move the support plate toward the fixed plate with the toggle link extended, and pinch the mold provided between the fixed plate and the movable plate. , thereby setting a state of zero mold clamping force. Then, the toggle link is retracted to separate the movable platen from the mold, and the support platen is moved toward the fixed platen by a predetermined amount. Thereby, a predetermined mold clamping force is generated in the mold when the toggle link is extended.

As described above, the toggle type mold clamping device has a problem in that the above-mentioned mold thickness adjustment must be performed by a human, which is inefficient. For this reason, conventional proposals have been made to automatically perform upward die thickness adjustment.

For example, in the method disclosed in JP-A-53-74563, after a person sets the mold clamping force zero point and retracts the toggle link to separate the movable plate from the mold, the support plate is moved and the mold is removed. It automatically sets the tightening force. In addition, the device according to Japanese Utility Model Publication No. 46-27461 detects the amount of movement of the support plate and constantly displays the mold thickness dimension between the movable plate and the fixed plate with the toggle link extended, and presses the button. While being pressed, the support plate automatically moves toward and away from the fixed plate. Therefore, with this mold thickness adjustment device, while looking at the display of the mold thickness dimension,
A push button is pressed to set the desired mold thickness.

[Problems to be Solved by the Invention] Therefore, in the case of the mold thickness adjusting device disclosed in JP-A-53-74563, the movable platen is removed from the mold by setting the mold clamping force zero point and retracting the toggle link. There was a problem in that a person had to perform the operation of releasing the button, which was troublesome and time-consuming. Furthermore, in the case of the mold thickness adjusting device disclosed in Japanese Utility Model Publication No. 46-27461, the mold thickness must be set by a person while looking at the dimension display between the movable platen and the fixed platen. Thickness adjustment has not yet been completely automated, and there are problems in that the operation is troublesome and it is not possible to quickly and accurately set the mold thickness.

The present invention was made in view of the above circumstances, and provides a toggle type mold clamping device that can automatically set a mold thickness dimension that can generate a predetermined mold clamping force by simply inputting the mold thickness dimension. The purpose of this invention is to provide a mold thickness adjustment device.

[Means for Solving the Problems] The present invention has been made to achieve the above object, and includes a position detection sensor that is connected to a rotational drive mechanism to rotate and detects the amount of movement of a support plate, and a toggle. The current value of the mold thickness dimension between the movable plate and the fixed plate with the link extended is input, and when the support plate is moved, the amount of movement detected by the position detection sensor is added to or subtracted from the current value. a current value holding circuit that holds the current value after the adjustment, a mold thickness setting section that manually sets the mold thickness dimension such that a predetermined mold clamping force is generated for a predetermined mold; a mold thickness comparison circuit that compares the current value held in the value holding circuit with the setting value of the mold thickness setting section to determine the moving direction of the support plate; and a mold thickness comparison circuit that controls the rotational drive mechanism to set the current value. The present invention is characterized by comprising a control circuit that moves the support plate based on the determination result of the mold thickness comparison circuit until the mold thickness comparison circuit reaches a certain value.

[Operation] In order to set the mold thickness dimension to a predetermined value in the present invention, the mold to be used is installed in a mold clamping device in advance, and the mold thickness dimension with respect to a predetermined mold clamping force is measured. Then, by inputting the measured value of the mold thickness dimension into a set value to the mold thickness setting section, the mold thickness dimension with a predetermined mold clamping force is obtained.

In this case, the mold thickness dimension is set by inputting a set value into the mold thickness setting section with the mold removed. Then, the rotation drive mechanism is controlled by the control circuit, and the support plate is moved so that the current value held by the current value holding circuit 1 approaches the set value of the mold thickness dimension.

Then, when the current value reaches the set value, the operation of the rotary drive mechanism is stopped and the mold thickness is set to a predetermined mold thickness.

[Example 7] Hereinafter, an example in which the present invention is applied to a mold clamping device of an injection molding machine will be described with reference to FIGS. 1 to 5.

First Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

In FIG. 1, l is a base of an injection molding machine, and a stationary plate 2 is fixed to the upper surface of this base l.

Further, on the base l, a support plate 3 is mounted opposite to the fixed plate 2! The support plate 3 and the fixed plate 2 are connected by four tie bars 4. Between the support plate 3 and the fixed plate 2 there is a plate supported by the tie bars 4. A movable plate 5 is provided which moves forward and backward relative to the fixed plate 2 while being guided, and the movable plate 5 is moved by a telescopic toggle link 6 using the support plate 3 as a fulcrum. . The toggle link 6 expands and contracts by moving the rod 7a of the cylinder 7 attached to the support plate 3, and the toggle link 6 is expanded and contracted by moving the rod 7a of the cylinder 7 attached to the support plate 3.
When ・ becomes a straight line, the movable plate 5 approaches the fixed plate 2 as far as possible. In this embodiment, when the movable platen 5 is closest to the fixed platen 2, the dimension between the surfaces of the molds is called the mold thickness dimension.

Further, a tie bar 4 protrudes from the side of the support plate 3 opposite to the fixed plate 2, and a pinion gear (femally threaded member) 8 is screwed into a threaded portion 4a formed at the end of the tie bar 4. The pinion gear 8 is rotatably pressed against the support plate 3 by a presser (not shown), so that it always moves together with the support plate 3. The pinion gear 8 is rotationally driven by a ring gear 9 and a hydraulic motor 11 provided as a rotational drive mechanism. That is, one ring gear 9 is rotatably attached to the support plate 3 so as to mesh with each pinion gear 8, and is provided at the center of the four pinion gears 8. Hydraulic motor 11 with pinion gear 10 meshing with ring gear 9
is installed.

By rotating the hydraulic motor II, four pinion gears 8 are simultaneously rotated via the ring gear 9, and the support plate 3 is moved in the axial direction of the tie bar 4. Further, the hydraulic motor 11 is connected to a hydraulic control valve 12, and the hydraulic control valve 12 is connected to a mold thickness control device 13.
It is now controlled by. Furthermore, a pulse sensor (position detection sensor) 15 having a pinion gear 14 that meshes with the ring gear 9 is provided on the side of the ring gear 9 . The pulse sensor 15 is II), down
It uses a pulse generator, and depending on the gear ratio between the pinion gear 14, the ring, and the gear 9, l pulses are generated by the support plate 3.
It is set to correspond to a movement amount of 0.1+nm or 0.01mn+. And this pulse sensor 1
5 is connected to the mold thickness control device I3, and the pulse signal from the pulse sensor 15 is output to the mold thickness control device I3.

Additionally, mold clamping force detection sensors 16 are provided at both ends of the tie bar 4 to measure the elongation of the tie bar 4 and detect the mold clamping force of the mold. This mold clamping force detection sensor 16 is also connected to the mold thickness control device I3, and the mold clamping force detected by the mold clamping force detection sensor 16 is output to the mold thickness control device 13. .

Furthermore, an origin limit switch 17 is provided below the movable platen 5. The origin limit switch 17 is
The support plate 3 is moved to the fixed plate 2 side with the link 6a extended in a straight line, and it is activated when the mold thickness dimension K becomes the minimum, and the activation signal is sent to the mold thickness control device 13. It has become.

The mold thickness control device 13 automatically sets the mold thickness dimension K by inputting a value for the mold thickness dimension that takes into account the generation of a predetermined mold clamping force, as shown in FIG. It is composed of In this figure, reference numeral 20 denotes a current value holding circuit, and this current value holding circuit 20 holds the current value of the mold thickness dimension, and when the support plate 3 is moved, the current value is sent from the pulse sensor 15. The amount of movement of the support plate 3 is calculated based on the received pulse signal, this amount of movement is added or subtracted from the current value already held, and that value is held again. Furthermore, the current value holding circuit is compensated for the current value in the event of a power outage. Also,
If data is not manually input to the current value holding circuit 20,
Alternatively, a protection circuit 21 is provided in case an error occurs in the current value due to noise or the like. In the protection circuit 21, an origin mold thickness dimension that is equal to the mold thickness dimension K when the support board 3 is moved and the origin limit switch I7 is activated is recorded, and the origin limit switch I7 is
By operating , the origin mold thickness dimension is input to the current value holding circuit 20 . Further, the current value held in the current value holding circuit 20 is compared with the set value of the mold thickness dimension set in the mold thickness setting section 22 by the mold thickness comparison circuit 23. The mold thickness setting section 22 inputs, through data communication, a set value for a mold thickness dimension that is unique to each mold recorded in the molding condition data pack 24 and that can obtain a predetermined mold clamping force. It is to be recorded. In addition, the mold thickness comparison circuit 23 calculates that the set value and the current value are (set value + allowable dimension α) current value, (set value - allowable dimension α)>current value, (set value + allowable dimension α)≧current value. This is to judge whether the value ≧ (set value - allowable dimension α). Further, the movement direction comparison circuit 25 calculates the current movement direction of the support plate 3 obtained by comparing the set value and the current value in the mold thickness comparison circuit 23, and the support plate 3 recorded at the time of movement of the face support plate 3. 3
The drive system play correction circuit 26 is operated to compare the moving directions of the two moving directions. The drive system play correction circuit 26 does not output pulse signals to the current value holding circuit until the number of pulse signals from the pulse sensor 15 reaches a number corresponding to the amount of play in the drive system, and increases or decreases the current value. It is designed to prevent this from happening. Further, a control circuit 27 is provided that controls the hydraulic pressure control valve 12 based on comparison data between the set value of the mold thickness comparison circuit 23 and the current value. The control circuit 27 instructs the hydraulic control valve 12 to move the support plate 3 toward the fixed plate 2 when the relationship between the set value and the current value is (set value + allowable dimension α) <current value. Furthermore, if (set value - allowable dimension α)>current value, a command is given to the hydraulic control valve 12 so that the support plate 3 moves toward the side opposite to the fixed plate 2. Further, a deceleration circuit 28 acts on the control circuit 27. The deceleration circuit 28 acts on the control circuit 27 to reduce the moving speed of the support plate 3 when the difference between the set value and the current value satisfies the condition of 1 set value - 1 <deceleration interval γ. be.

The mold clamping force setting section 29 also includes a molding condition data pack 24.
The upper and lower limit values of the mold clamping force corresponding to the set value of the mold thickness dimension recorded in are input and recorded. Then, the upper limit value and lower limit value of the mold clamping force are compared with the actual mold clamping force outputted from the mold clamping force detection sensor 16 and the mold clamping force comparison circuit 3.
It is set to be compared with 0. Furthermore, a mold clamping force monitoring circuit 31 is provided to monitor the mold clamping force based on the data compared by the mold clamping force comparison circuit 30. By pressing the mold clamping force monitoring command button 32, the mold clamping force can be adjusted. Abnormalities and abnormal conditions are output to an insufficient mold clamping force indicator 33, an excessive mold clamping force indicator 34, or an appropriate mold clamping force indicator 35.

Further, the current value held in the current value holding circuit 20, the setting value for the mold thickness dimension recorded in the mold thickness setting section 22, the upper and lower limit values of the mold clamping force recorded in the mold clamping force setting section 29, and the mold The mold clamping force detected by the clamping force detection sensor 16 is displayed on a current value display 36, a set value display 37 for the mold thickness dimension, a display 38 for the upper and lower limits of the mold clamping force, and a mold clamping force display. It is displayed on the display 39.

Next, a method of setting the mold thickness dimension K using the mold thickness adjusting device of the toggle type mold clamping device configured as described above and a flow of mold thickness adjustment will be explained.

First, before using this mold thickness adjustment device, attach the mold to be used to the mold clamping device and set the mold thickness dimension K for the predetermined mold clamping force.
Measure.

Then, when the mold thickness dimension K is manually entered into the mold thickness setting section 22, as shown in step s1 of FIG. 4, the set value of the mold thickness dimension is compared with the current value. Here, if the magnitude relationship between the set value and the current value satisfies the condition of (set value + allowable dimension α) ≧ current value ≧ (set value - allowable dimension α),
It is determined that the surface and current mold thickness are the same, and the mold thickness adjustment is completed. Further, if (setting value + allowable dimension α)>current value or (setting value - allowable dimension α)>current value, mold thickness adjustment is performed. However, since the flow of mold thickness adjustment for both types differs only in the moving direction of the support plate 3, the explanation will be based on the case of the current value (setting value and allowable dimension α), and (
Setting value - allowable dimension α)〉Explanation will be omitted for the case of current value. That is, if it is determined in step St that the magnitude relationship between the set value and the current value is (set value + allowable dimension α) <current value, then in step S2 it is determined that the magnitude relationship between the set value and the current value is 1 set value - current value 1 <deceleration interval γ A judgment is made as to whether the above conditions are satisfied, and if the above conditions are not satisfied, step 53
-1, the hydraulic motor 11 rotates, and the support plate 3 attempts to move toward the fixed plate 2 side. Then, in step 4, it is determined whether the moving direction of the support plate 3 is the same between the previous time and this time, and if it is not the same, it is further determined in step 54-1 whether or not the amount of play in the drive system is zero. If the current value is zero, the process proceeds to step S5, where the current value is decreased by the pulse signal of the pulse sensor 15. However, if it is determined that the amount of play is not zero, the current value is not reduced and the process returns to step S1 to repeat the same operation as described above. This means that if the amount of play is present, the hydraulic motor l! This is because the support plate 3 does not move until the amount of play disappears even when the pulse sensor 15 rotates and a pulse signal is output from the pulse sensor 15. After starting, the pulse sensor 15 outputs a pulse signal to decrease the current value. In addition, if the moving direction of the support plate 3 is the same in the previous and current times in step 4, the amount of play in the drive system is zero, so proceed to step 5, the current value is decreased by the pulse signal, and return to step 1 again. . The above operation is repeated, and when the current value approaches the set value j, the condition of 1 set value - current value 1 <deceleration section γ in step S2 is satisfied, and the process moves to step 53-2, where the support plate 3 is Starts moving at a slower speed. Furthermore, the support plate 3 moves (setting value + allowable dimension α)
When the condition ≧current value≧(set value−allowable dimension α) is reached, mold thickness adjustment is completed.

According to the mold thickness adjusting device of the toggle type mold clamping device configured as described above, by operating the mold thickness control device 13, the predetermined mold thickness dimension K is set fully automatically without any human operation. be able to. Therefore, the mold thickness adjustment, which has been troublesome in the past, can be performed easily and in a short time. Also,
Since the drive system play amount correction circuit 26 is provided, even if the moving direction of the support plate 3 is different between the previous time and this time, the current value of the current value holding circuit 20 and the actual mold thickness dimension can be adjusted depending on the drive system play amount. There will be no error between the two.

Therefore, the mold thickness dimension K can be accurately set to the set value. Furthermore, since the protection circuit 21 is provided, even if an error occurs in the current value of the current value holding circuit 20 due to noise etc., the current value holding circuit 20 can be easily set to the origin corresponding to the actual mold thickness dimension K. It is extremely convenient to be able to input the mold thickness dimension. Furthermore, since the deceleration circuit 28 is provided, the moving speed of the support plate 3 can be reduced in the straight-curved deceleration section γ where the support plate 3 stops, and the mold thickness dimension K can be accurately adjusted to the set value. can.

Furthermore, since a mold clamping force detection sensor 16 is provided,
It is possible to detect the mold clamping force when the mold is actually clamped by the mold clamping device, and since the mold clamping force monitoring device 31 is provided, it is possible to monitor insufficient or excessive mold clamping force. The mold thickness can be reliably confirmed by checking whether the mold clamping force is within the allowable range.

In addition, in the above embodiment, the origin limit switch 1
7 is provided on the lower side of the movable platen so as to be activated when the mold thickness is the minimum, but as long as the mold thickness at which the origin limit switch 17 is activated is known, the origin limit switch 17 may be placed at any position. However, in order to avoid interfering with the movement of the movable platen and support plate, the mold mounting surface of the movable platen at the minimum mold thickness position or the surface opposite to the fixed platen of the support plate at the maximum mold thickness position should be contacted. It is preferable to provide this.

Furthermore, although the mold thickness setting unit 22 is configured to input setting values from the molding condition data pack 24 through data communication, it may also be configured such that the setting values are input by a person using a digital thumbwheel switch or the like.

Further, although an example in which the present invention is applied to a mold clamping device of an injection molding machine has been shown, the present invention may also be applied to a toggle type mold clamping device such as a die casting machine.

Furthermore, although an up and down pulse generator is used as the position detection sensor, an incremental encoder or the like may also be used.

Second Embodiment A second embodiment will be described with reference to FIG. In this figure, the same elements as those of the first embodiment shown in FIG. 3 are given the same reference numerals, and their explanations will be omitted. In the second embodiment, an overrun circuit 40 is provided in place of the moving direction comparison circuit 25 and drive system play amount correction circuit 26 shown in the first embodiment. That is, the overrun circuit 40 is
The mold thickness comparison circuit 23 determines that the relationship between the set value and the current value is (set value - allowable dimension α) and the mold thickness dimension K.
When setting the mold thickness K in the direction of increasing, the control circuit is operated to widen the mold thickness dimension K by a predetermined dimension from the set value. After the mold thickness dimension K increases by a predetermined dimension from the set value, the control circuit moves the support plate 3 toward the fixed plate 2 side and sets the mold thickness dimension K in a direction in which the mold thickness dimension K decreases. It looks like this.

Therefore, according to the mold thickness adjustment device of the toggle type mold clamping device configured in this way, the support plate 3 is always moved to the fixed plate 2 side to set the mold thickness, so there is no play in the drive system. , there is no error in setting the mold thickness dimension due to the play m. Therefore, it is possible to accurately set the die thickness dimension according to the set value. Furthermore, since the reaction force from the mold can be maintained without any play, a stable mold clamping force can be maintained.

[Effects of the Invention] As explained above, according to the present invention, a predetermined mold thickness can be set fully automatically by simply inputting a set value of the mold thickness into the mold thickness setting section. Therefore, mold thickness adjustment, which has been troublesome in the past, can be easily and accurately performed in a short time.

[Brief explanation of the drawing]

1 to 4 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a rear end recovery of a toggle type mold clamping device, FIG. 2 is a side view of the same toggle type mold clamping device, FIG. 3 is a block diagram showing the configuration of the mold thickness control device, FIG. 4 is a diagram showing the flow of mold thickness adjustment, and FIG. 5 is a block diagram showing the configuration of the mold thickness control device shown in the second embodiment. be. 2...Fixed plate, 3...Support plate, 4...
...Tie bar, 4a...Threaded part, 5...
...Movement board, 6...Toggle link, 8...
...Pinion gear (female thread member), I5...
Pulse sensor (position detection sensor), 20...Current value holding circuit, 22...Mold thickness setting section, 23...
...Mold thickness comparison circuit, 27...Control circuit, K
・・・・・・Mold thickness dimension.

Claims (1)

[Claims] A movable plate is movably provided on a plurality of tie bars passed between a fixed plate and a support plate, and the movable plate is driven to move by a toggle link that expands and contracts with the support plate as a fulcrum, The support plate is driven to move toward and away from the stationary plate by a female screw member that is screwed into a screw portion formed at an end of the tie bar and rotates synchronously, and the female screw member is rotationally driven by a rotational drive mechanism. In the mold thickness adjustment device of the toggle type mold clamping device, the position detection sensor is connected to the rotary drive mechanism and rotates to detect the movement amount of the support plate, and the movable plate and the fixed plate in a state where the toggle link is extended. When the current value of the mold thickness dimension between is input and the support plate is moved, the amount of movement detected by the position detection sensor is added to or subtracted from the current value, and the current value after the adjustment is maintained. a value holding circuit; a mold thickness setting section for inputting a set value of a mold thickness dimension such that a predetermined mold clamping force is generated for a predetermined mold; a mold thickness comparison circuit that determines the moving direction of the support plate by comparing the current value with the set value of the thickness setting section; A mold thickness adjusting device for a toggle type mold clamping device, comprising a control circuit that moves the mold thickness based on the determination result of the comparison circuit.