JPH0528971B2 - - Google Patents

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 divers are passed between a fixed plate fixed on a base and a support plate movably supported on the base. The movable platen 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 molds of the movable platen and the fixed platen, and the support platen is moved by a predetermined amount toward the fixed platen side. 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 the problem of poor efficiency because the mold thickness must be adjusted by a human as described above. For this reason, proposals have been made to automatically adjust the mold thickness. For example, the one published in Japanese Patent Application Laid-Open No. 53-74563 is
After a person sets the mold clamping force zero point and retracts the toggle link to move the movable plate away from the mold, the support plate is moved to automatically set the mold clamping force. In addition, the one according to Utility Model Publication No. 46-27461 detects the amount of movement of the support plate.
The mold thickness dimension between the movable plate and fixed plate with the toggle link extended is always displayed, and while the push button is pressed, the support plate automatically moves in the direction towards and away from the fixed plate. It is something. Therefore, in this mold thickness adjusting device, a predetermined mold thickness is set by pressing a push button while looking at the display of the mold thickness dimension.

In the case of the mold thickness adjusting device disclosed in JP-A No. 53-74563, humans must set the mold clamping force zero point and retract the toggle link to separate the movable platen from the mold. The problem was that it was troublesome and time consuming. Also, Jikko 46-
In the case of the mold thickness adjustment device of Publication No. 27461, a person must set the mold thickness while looking at the dimension display between the movable plate and the fixed plate, but in this case as well, mold thickness adjustment can be completely automated. However, there are problems in that the operation is troublesome and it is not possible to quickly set the mold thickness with high precision.

For this reason, there is an input section for inputting the dimension information of the mold attached to the mutually opposing surfaces of the fixed platen and the movable platen, and a support to which the movable platen operating mechanism is attached based on the input from this input section. A support plate moving mechanism that moves the plate in a predetermined direction, a movement amount detection means that detects the amount of movement of the support plate moved by the support plate movement mechanism, and a movement amount detection means that moves the support plate in a predetermined position. A mold thickness adjusting device has been proposed (Japanese Unexamined Patent Publication No. 141842/1984), which includes a control means for stopping the moving operation by the supporting plate moving mechanism when it is detected that the supporting plate moving mechanism has reached the supporting plate moving mechanism.

[Problems to be Solved by the Invention] However, the device disclosed in JP-A-58-141842 cannot correct the "play" that inevitably exists in the screw mechanism of the drive system that moves the support plate. There is a problem that the adjustment accuracy is low. Also,
Manually correcting the above-mentioned play requires a lot of effort and time, similar to the devices disclosed in Japanese Unexamined Patent Publication No. 53-74563 and Japanese Utility Model Publication No. 46-27461.

The present invention has been made in view of the above circumstances, and by simply inputting the mold thickness dimension, play in the drive system is corrected and the mold thickness dimension is reliably set to automatically generate a predetermined mold clamping force. It is an object of the present invention to provide a mold thickness adjustment device for a toggle type mold clamping device that can be used to adjust the mold thickness of a toggle type mold clamping device.

[Means for Solving the Problems] In order to achieve the above object, the first invention provides a movable platen that is movably provided on a plurality of tie bars passed between a fixed platen and a support plate. is moved and driven by a toggle link that expands and contracts with the support plate as a fulcrum, and the support plate is separated from the fixed plate by a female screw member that is screwed into a threaded portion formed at the end of the tie bar and rotates in synchronization. In a mold thickness adjustment device of a toggle type mold clamping device, which is driven to move in a tangential direction, and in which the female screw member is rotationally driven by a rotational drive mechanism, the female screw member rotates while being connected to the rotational drive mechanism to detect the amount of movement of the support plate. When the support plate is moved to the current value of the mold thickness between the movable plate and the fixed plate in the state where the toggle link is extended in response to the output signal of the position detection sensor and the position detection sensor, the position detection is performed. A current value holding circuit that adjusts the amount of movement detected by the sensor and holds the current value after adjustment, and a clamping mold thickness dimension that generates a predetermined clamping force for a predetermined mold. a mold thickness setting section for inputting a set value; a mold thickness comparison circuit for determining the moving direction of the support plate by comparing the current value held by the current value holding circuit with the set value of the mold thickness setting section; a moving direction comparison circuit that compares the current moving direction of the support plate determined by the die thickness comparison circuit with the previous moving direction of the support plate; a drive system play amount correction circuit that operates when the two moving directions are different and outputs the output signal of the position detection sensor to the current value holding circuit after the output signal from the position detection sensor reaches the play amount of the drive system; The mold thickness comparison circuit is configured to include a control circuit that controls the rotational drive mechanism to move the support plate based on the determination result of the mold thickness comparison circuit until the current value reaches a set value.

Further, in a second invention, 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 the 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 rotation drive mechanism and rotates to detect the movement amount of the support plate, and the toggle link receives an output signal of the position detection sensor. After the amount of movement detected by the position detection sensor when the support plate is moved is adjusted to the current value of the mold thickness between the movable plate and the fixed plate in the extended state. a current value holding circuit that holds the current value of , a mold thickness setting section that inputs a setting value of a clamping mold thickness dimension that produces a predetermined mold clamping force for a predetermined mold, and the current value holding circuit. a mold thickness comparison circuit that compares the current value held by the mold thickness setting unit with the set value of the mold thickness setting unit to determine the moving direction of the support plate; and a mold thickness comparison circuit that controls the rotational drive mechanism so that the current value reaches the set value. a control circuit that moves the support plate until the current value is smaller than a set value and the current value is increased as a result of the comparison and judgment by the mold thickness comparison circuit; When adjusting by moving the support plate, the above set value is temporarily set to a larger value by a predetermined dimension, and after the support plate has moved excessively in the increasing direction, the temporary set value is returned to the original set value. The configuration includes an overrun circuit that readjusts the current value in a direction that decreases it.

[Operation] In the first invention, the moving direction comparison circuit compares the current moving direction of the support plate determined by the mold thickness comparing circuit with the previous moving direction. The drive system play amount correction circuit receives the output signal from the movement direction comparison circuit and operates when the current and previous movement directions are different, and detects the position after the output signal from the position detection sensor reaches the drive system play amount. The sensor output signal is output to the current value holding circuit. Therefore, play in the drive system does not cause errors in mold thickness adjustment.

Further, in the second invention, the overrun circuit includes:
As a result of comparison judgment by the mold thickness comparison circuit between the current value held in the current value holding circuit and the value set in the mold thickness setting section, the current value is smaller than the set value and the support plate is moved in the direction where the current value increases. When adjusting by
The set value is temporarily increased by a predetermined dimension, and after the support plate moves excessively in the direction of increase, the provisional set value is returned to the original set value and the current value is readjusted in the direction of decreasing. Therefore, the support plate always moves to the fixed plate side to adjust the mold thickness, so play in the drive system will not cause an error in this case as well.

[Example] 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, reference numeral 1 denotes a base of an injection molding machine, and a fixed platen 2 is fixed to the upper surface of this base 1. Further, a support plate 3 is provided on the base 1 so as to be movable and adjustable on the base 1, facing the fixed plate 2, and the support plate 3 and the fixed plate 2 are connected to each other by four tie bars. Connected by 4. Supported and guided by tie bars 4 between the support plate 3 and the fixed plate 2,
A movable plate 5 is provided that moves forward and backward relative to the fixed plate 2, 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 when the links 6a located above and below become straight, the movable plate 5 is closest to fixed plate 2. The dimension between the mold mounting surfaces when the movable platen 5 comes closest and the molds of the movable platen 5 and the fixed platen 2 are in close contact with each other is hereinafter referred to as the actual mold thickness dimension K ₀ .

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. And pinion gear 8
is a ring gear 9 provided as a rotational drive mechanism.
and is rotationally driven by a hydraulic motor 11. That is, one ring gear 9 is provided at the center of the four pinion gears 8 and is rotatably attached to the support plate 3 so as to mesh with each pinion gear 8. A hydraulic motor 11 having a pinion gear 10 meshing with ring gear 9 is attached. By rotating the hydraulic motor 11, the four pinion gears 8 are simultaneously rotated via the ring gear 9, and the support plate 3 is connected to the tie bar 4.
It is designed to move in the axial direction. Further, the hydraulic motor 11 is connected to a hydraulic control valve 12, and the hydraulic control valve 12 is controlled by a mold thickness control device 13. 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 . Pulse sensor 1
5 uses an up/down pulse generator, and depending on the gear ratio between the pinion gear 14 and the ring gear 9, one pulse corresponds to 0.1 mm or 0.01 mm of the support plate 3.
It is set to correspond to the amount of movement in mm. This pulse sensor 15 is connected to the mold thickness control device 13.
The pulse signal from the pulse sensor 15 is output to the mold thickness control device 13.

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 13, 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 activated when the support plate 3 is moved toward the fixed plate 2 side with the link 6a extended in a straight line and reaches the origin (usually the position of the minimum actual thickness dimension K _O ). , the activation signal is sent to the mold thickness control device 13.

The mold thickness control device 13 determines a dimension obtained by subtracting the mold clamping amount necessary to obtain a predetermined mold clamping force from the actual mold thickness dimension K _O (hereinafter referred to as mold thickness dimension K or mold clamping mold thickness dimension). ) by entering the value of the mold thickness dimension K
It is configured as shown in FIG. 3. In this figure, reference numeral 20
is a current value holding circuit, and this current value holding circuit 2
0 holds the current value Ka of the mold thickness dimension, and when the support plate 3 is moved, the pulse sensor 15
The amount of movement of the support plate 3 is calculated based on the pulse signal sent from the controller, 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. In addition, in case data is not input to the current value holding circuit 20 or in case an error occurs in the current value due to noise etc., the protection circuit 2
1 is provided. In the protection circuit 21, the mold thickness dimension when the support plate 3 is moved and the origin limit switch 17 is activated is recorded, and by operating the origin limit switch 17, the origin mold thickness is recorded. Dimension current value holding circuit 20
This is what you input. In addition, the current value holding circuit 2
The current value held at 0 is compared by a mold thickness comparison circuit 23 with a set value of the mold thickness dimension K input to the mold thickness setting section 22 (input via data communication described later). The mold thickness setting section 22 inputs, through data communication, the setting value of the mold thickness dimension K, which is unique to each mold recorded in the molding condition data pack 24 and is capable of obtaining a predetermined mold clamping force. It is to be recorded. In addition, the mold thickness comparison circuit 2
3, set value K and current value Ka are (set value + allowable dimension α) < current value, (set value - allowable dimension α) > current value, (set value + allowable dimension α) ≧ current value ≧ (setting value - allowable dimension α). Further, the moving direction comparison circuit 25 includes a mold thickness comparison circuit 23.
The current movement direction of the support plate 3 obtained by comparing the set value and the current value is compared with the movement direction of the support plate 3 recorded during the previous movement of the support plate 3. When the moving directions are different, a drive system play amount correction circuit 26 is activated. The drive system play amount 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. Further, if (set value - allowable dimension α)>current value, a command is given to the hydraulic control valve 12 to move the support plate 3 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 |set value - current value|<deceleration section γ. be.

Further, the mold clamping force setting section 29 inputs and records upper and lower limit values of the mold clamping force corresponding to the set value of the mold thickness dimension K recorded in the molding condition data pack 24. The upper and lower limits of the clamping force are compared with the actual clamping force output from the clamping force detection sensor 16 by a clamping force comparison circuit 30. Furthermore, the mold clamping force comparison circuit 30
A mold clamping force monitoring circuit 31 is provided to monitor the mold clamping force based on the data compared with the mold clamping force monitoring circuit 31, and by pressing the mold clamping force monitoring command button 32, abnormalities in the mold clamping force and abnormal conditions can be detected. It is designed to be output to an insufficient clamping force indicator 33, an excessive mold clamping force indicator 34, or an appropriate mold clamping force indicator 35.

Furthermore, the current value held in the current value holding circuit 20, the set value of the mold thickness dimension K 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 setting value display 37 for mold thickness dimension K, a display 38 for upper and lower limit values of mold clamping force, and a mold clamping force display. It is now displayed on the display 39.

Next, a method of setting the mold thickness dimension K using the mold thickness adjustment 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. At this time, a mold thickness dimension K of the mold corresponding to a predetermined mold clamping force measured in advance is set in the data pack 24.

When the mold thickness dimension K is input from the data pack 24 to the mold thickness setting section 22, the set value of the mold thickness dimension K is compared with the current value, as shown in step S1 in FIG. . Here, if the magnitude relationship between the set value and the current value satisfies the following condition: (set value + allowable dimension α) ≧ current value ≧ (set value - allowable dimension α), the mold thicknesses of the previous and current molds are the same. It is determined that there is, and mold thickness adjustment is completed. Also,
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 where (setting value + allowable dimension α) < current value.
If (set value−allowable dimension α)>current value, the explanation will be omitted. That is, if it is determined in step S1 that the magnitude relationship between the set value and the current value is (set value + allowable dimension α) < current value, then in step S2, | set value - current value | < deceleration section γ If the above conditions are not satisfied, the process proceeds to step S3-1, where the hydraulic motor 11 rotates and the support plate 3 tries to move toward the fixed plate 2. . And the steps
In S4, it is determined whether the moving direction of the support plate 3 is the same last time and this time, and if it is not the same, it is further determined in step S4-1 whether or not the amount of play in the drive system is zero. In this case, the process advances to step S5, where the current value is decreased by the pulse signal from the pulse sensor 15. However, if it is determined that the amount of play is not zero, the current value is not decreased and the process returns to step S1 to repeat the same operation as described above. This means that if there is an amount of play, the hydraulic motor 11
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. Also, in step S4, support plate 3 was added in the previous and this time.
If the directions of movement are the same, the amount of play in the drive system is zero, so the process proceeds to step S5, the current value is decreased by the pulse signal, and the process returns to step S1. Then, as the above operation is repeated and the current value approaches the set value, step S2 |Set value - Current value|<
When the conditions of the deceleration section γ are satisfied, step S3-
2, the support plate 3 begins to move at low speed. Furthermore, when the support plate 3 moves to a state where (setting value + allowable dimension α)≧current value≧(setting value−allowable dimension α), the 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, mold thickness adjustment, which has been troublesome in the past, can be easily and quickly performed. In addition, 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 model are adjusted depending on the drive system play amount. There is no error between the thickness and the thickness.
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 origin type thickness dimension can be easily corrected. Extremely convenient. Furthermore, since the deceleration circuit 28 is provided, the moving speed of the support plate 3 can be reduced in the deceleration section γ immediately before the support plate 3 stops, and the mold thickness dimension K can be accurately adjusted to the set value. . 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 a mold clamping force monitoring device 31 is also provided. Therefore, it is possible to monitor whether the mold clamping force is insufficient or excessive, and the mold thickness dimension can be reliably confirmed depending on whether the mold clamping force is within the allowable range.

In the above embodiment, the origin limit switch 17 is provided below the movable platen and is activated when the mold thickness is the minimum.
The origin limit switch 17 may be placed at any position as long as the mold thickness when it is activated is known. However, in order to avoid interfering with the movement of the movable platen and support plate, it should be in contact with 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. It is preferable to provide one.

Further, although the mold thickness setting section 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 thumb wheel 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, it can be used as a position detection sensor for up and down
Although a pulse generator was used, an incremental encoder or the like may also be used.

Second Example A second example 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. This second embodiment has a moving direction comparison circuit 25 and a drive system play amount correction circuit 26 shown in the first embodiment.
An overrun circuit 40 is provided instead. That is, the Eberrun circuit 40 determines that the relationship between the set value and the current value is (set value - allowable dimension α)>current value in the mold thickness comparison circuit 23, and the current value Ka increases, that is, the mold opens. When adjusting the mold thickness by moving the support plate 3 in the direction (away from the fixed plate 2 side), the above set value K is temporarily set to a larger value by a predetermined dimension, and the support plate 3 is moved in the mold opening direction. After over-traveling beyond the set value K, the provisional set value is returned to the original set value K, and the current value K _O is readjusted in the direction of decreasing.

Therefore, according to the mold thickness adjusting device of the toggle type mold clamping device configured in this way, play in the drive system does not occur because the mold thickness is set by always moving the support plate 3 to the fixed plate 2 side. There is no error in setting the mold thickness dimension K due to the amount of play. Therefore, it is possible to accurately set the mold thickness 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, by simply inputting the set value of the mold thickness dimension into the mold thickness setting section, play in the drive system is automatically corrected and the predetermined value is fully automatically adjusted. Can be set to mold thickness dimension. Therefore, mold thickness adjustment, which has been troublesome in the past, can be performed easily, quickly and accurately.

[Brief explanation of the drawing]

1 to 4 are views showing a first embodiment of the present invention, in which FIG. 1 is a rear end view of the toggle type mold clamping adjustment device, and FIG. 2 is a side view of the toggle type mold clamping device. 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. It is a diagram. 2...Fixed plate, 3...Support plate, 4...Tie bar, 4a...Threaded portion, 5...Moveable plate, 6...Toggle link, 8...Pinion gear (female thread member),
15...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. In a method of casting a molten polyester polymer extruded from a molding die by contacting it with the surface of a cooling body, 0.001 to 30wt of at least one selected from the following (a) to (d) is applied to the surface of the cooling body. 1. A polyester casting method characterized by forming a liquid film of water containing 1.

Claims (1)

A moving direction comparison circuit 25 receives an output signal from the moving direction comparing circuit 25 and operates when the current and previous moving directions are different, and the output signal from the position detection sensor 15 detects play in the drive system. A drive system play amount correction circuit 26 outputs the output signal of the position detection sensor 15 to the current value holding circuit 20 after the current value Ka reaches the set value K. A mold thickness adjusting device for a toggle-type mold clamping device, comprising: a control circuit 27 that moves the support plate 3 based on the judgment result of the mold thickness comparison circuit 23 until the mold thickness reaches . 2. A movable plate 5 is movably provided on a plurality of tie bars 4 passed between the fixed plate 2 and the support plate 3, and the movable plate 5 is movably driven by a toggle link 6 that expands and contracts with the support plate 3 as a fulcrum. and the support plate 3
is a threaded portion 4a formed at the end of the tie bar 4.
The mold of the toggle type mold clamping device is driven to move toward and away from the stationary plate 2 by a female threaded member 8 that is screwed together and rotates synchronously with the fixed platen. The thickness adjustment device includes a position detection sensor 15 connected to the rotary drive mechanisms 9 and 11 to rotate and detect the amount of movement of the support plate 3, and a position detection sensor 15 that extends the toggle link 6 upon receiving an output signal from the position detection sensor 15. When the support plate 3 is moved, the amount of movement detected by the position detection sensor 15 is added or subtracted to the current value Ka of the mold thickness dimension between the movable plate 5 and the fixed plate 2 in the state where the support plate 3 is moved. a current value holding circuit 20 that holds the current value Ka after the current value Ka, and a mold thickness setting section 22 that inputs a set value K of the clamping mold thickness dimension that generates a predetermined clamping force for a predetermined mold.
and the current value held by the current value holding circuit 20.
A mold thickness comparison circuit 2 that compares Ka with the set value K of the mold thickness setting section 22 to determine the moving direction of the support plate 3.
3, and the support plate 3 is controlled until the current value Ka reaches the set value K by controlling the rotation drive mechanisms 9 and 11.
a control circuit 27 for moving the mold thickness comparison circuit 23 based on the determination result of the mold thickness comparison circuit 23;
As a result of the comparative judgment, if the current value Ka is smaller than the set value K and the support plate 3 is moved in the direction in which the current value Ka increases, the set value K is temporarily increased by a predetermined dimension. An overrun circuit 40 is provided which sets a large provisional setting value and returns the provisional setting value to the original setting value K after the support plate 3 moves excessively in the increasing direction and readjusts it in the direction in which the current value Ka decreases. A mold thickness adjustment device for a toggle type mold clamping device.