JPH01184115A - Method and apparatus for adjusting mold clamping force in toggle type injection molding machine - Google Patents

Abstract

PURPOSE:To generate a mold clamping force as being set and to make it possible to carry out a precise injection molding, by determining positions of an end housing and a crosshead at the beginning of mold clamping based on a required value of the mold clamping force and a thickness of a mold to be used. CONSTITUTION:A position of a housing 3 is adjusted by extending a toggle link 8 in such a way that a distance between a movable plate 7 and a fixed plate 2 becomes smaller than the sum of thickness of molds 15 and 16 and a position detector on a stage 20 is set at a standard position. Then, the movable plate 7 is retreated to the side of the housing 3 and the molds 15 and 16 are attached on the fixed plate 2 and the movable plate 7. The movable plate 7 is then forwarded and both molds are brought into contact with each other. In a mold clamping force setting device and a mold thickness setting device of a controller, required values of mold clamping force and thickness of molds 15 and 16 are set and a distance between a crosshead 11 and the housing 3 is calculated by means of a calculator. Pulses corresponding to the calculated values are output from the controller and a stepping motor on the stage 20 is thereby driving to move the position detector 26 to a required position. Adjustment of the mold clamping force is thus completed.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a mold clamping force adjustment method for generating a desired mold clamping force in an injection molding machine, and a mold clamping force adjustment device used therein. In particular, the present invention relates to a mold clamping force adjustment method and device in a toggle type injection molding machine in which the mold clamping force is generated by a toggle type mold clamping device.

(Prior Art) An injection molding machine is designed to obtain a product in a predetermined shape by injecting molten resin at high pressure into the cavity of a closed mold. In such an injection molding machine, if the mold opens due to injection pressure during injection, flaws will occur in the resulting product. Therefore, it is necessary to clamp the mold with a force large enough to resist the injection pressure. However, if the mold clamping force is too strong, internal distortion will occur in the product due to overfilling or the like.

Therefore, in order to perform precision molding with an injection molding machine, it is necessary to appropriately adjust the mold clamping force. Therefore, injection molding machines are provided with a mold clamping device that can exert sufficient mold clamping force and can also adjust the mold clamping force. As such a mold clamping device, a toggle type mold clamping device is often used.

FIG. 1.2 is a side view showing an example of such a toggle type mold clamping device.

As is clear from these figures, bed 1 of the injection molding machine
A fixed platen 2 and an end housing 3 are installed on the top so as to face each other with a large interval. The fixed platen 2 is fixed to the upper surface of the bed 1. On the other hand, the end housing 3 is movably supported on the bed 1 via wheels or the like.

These fixed platen 2 and end housing 3 have four parallel tie bars 4, 4. are connected to each other by...

A threaded portion 4a is formed at the end of the tie bar 4 on the end housing 3 side, and a tie bar nut 5 is engaged with the threaded portion 4a. Although the tie bar nut 5 can be rotated about its axis by the holder 6, it is held fixed to the end housing 3 in the axial direction. Therefore, by rotating the tie bar nut 5, the end housing 3
is adapted to move in the front-rear direction along the tie bar 4, that is, in the direction approaching the fixed plate 2 or in the direction away from the fixed plate 2. And each tie bar nut 5,5.
... are simultaneously rotationally driven by an end housing moving device (not shown).

A movable platen 7 is provided between the fixed platen 2 and the end housing 3. This movable platen 7 has tie bars 4.4. It is slidably supported by... Therefore, this movable platen 7 is also movable in the axial direction of the tie bar 4, that is, in the direction toward and away from the fixed platen 2.

The end housing 3 is provided with an arm 3a that projects toward the movable platen 7 side.

The tip of the arm 3a and the movable platen 7 are connected by a toggle link 8.

This toggle link 8 includes a long link 9 whose one end is pin-coupled to the movable platen 7, and a short link 10 whose one end is pin-coupled to the long link 9 and the other end is pin-coupled to the arm 3a of the end housing 3. Four sets of link mechanisms each consisting of a cross link 12 having one end connected to the center of the short link 10 and a cross link 12 connected to the cross head 11 at the other end are arranged vertically and horizontally, respectively. The cross rod 11 is fixed to a piston rod 14 of a clamping cylinder 13 attached to the end housing 3, and is moved in the axial direction of the tie bar 4 by operating the clamping cylinder 13.

In this way, when the rod 11 is moved in the direction away from the end housing 3, the angle between the long link 9 and the short link 10 approaches 180°, the toggle link 8 is extended, and the movable platen 7 is moved from the fixed platen. It is pressed toward the second side. Further, when the rod 11 is moved toward the end housing 3 in a crosswise direction, the toggle link 8 contracts and the movable platen 7 separates from the fixed platen 2.

A fixed mold 15 and a movable mold 16 are attached to the fixed platen 2 and the movable platen 7, respectively, so as to face each other, and by moving and pressing the movable platen 7 toward the fixed platen 2, these molds are The molds 15 and 16 are closed and are further clamped.

When performing injection molding in an injection molding machine equipped with such a toggle type mold clamping device, first, the molds 15 and 1 are
6 is open, the mold clamping cylinder 13 is operated to cause its piston rod 14 to protrude. Then,
The crosshead 11 moves away from the end housing 3 and the toggle link 8 extends. As a result, the movable platen 7 moves forward toward the fixed platen 2, and finally the movable mold 16 comes into contact with the fixed mold 15 as shown in FIG. At this time, the toggle link 8 is brought into a slightly contracted state, that is, the long link 9 and the short link 10 are brought into a slightly bent state.

Mold clamping is started from this state. The position of the cross head 11 relative to the end housing 3 in this state will be referred to as the "mold touch position."

From this state, when high pressure is further applied to the clamping cylinder 13 to cause the piston rod 14 to protrude, the gap between the end housing 3 and the crosshead 11 is widened. Then, when the mold clamping cylinder 13 reaches the stroke end in the state shown in FIG. 2, the crosshead 11 stops moving relative to the end housing 3. In this state, the long link 9 and the short link 1o of the toggle link 8 are substantially straight, and the toggle link 8 is fully extended. The position of the crosshead 11 relative to the end housing 3 at this time will be referred to as the "mold clamping completion position."

From this mold touch position to the mold clamping completion position, the molds 15 and 16 are in contact with each other, so the movable platen 7 does not move. Therefore, the extension of the toggle link 8 during this period is absorbed by the retreat of the end housing 3, that is, the extension of the tie bar 4.

Then, a force corresponding to the reaction force is applied between the molds 15 and 16 via the toggle link 8.

That is, the molds 15 and 16 are clamped with a clamping force corresponding to the extension of the tie bars 4.

The mold clamping force at this time is F, the effective length of the tie bar 4, that is, from the back of the fixed platen 2 to the end housing 3 at the time when the molds 15 and 16 are in contact with each other with zero clamping force. β is the distance to the back side of
Then, the mold clamping force F is expressed as F=EA・8β/β according to Hooke's law. Here, E is the longitudinal elastic modulus of the tie bar 4.

This mold clamping force F can be adjusted by rotating the tie bar nut 5. That is, when the tie bar nut 5 is rotated, the end housing 3 moves in the axial direction of the tie bar 4. Therefore, when the effective length β of the tie bar 4 changes and the mold clamping starts when the molds 15 and 16 are in contact with each other with zero clamping force,
That is, the length of the toggle link 8 at the mold touch position changes. On the other hand, the mold clamping completion position is the position of the cross rod 11 relative to the end housing 3 when the mold clamping cylinder 13 reaches the stroke end, so the distance therebetween is constant. At that time, the toggle link 8 is fully extended, so its length remains constant. Therefore, when the end housing 3 is in the mold clamping completion position,
The distance between the end housing 3 and the fixed platen 2 is always constant regardless of the position of the end housing 3 at the start of mold clamping. As a result, the amount of elongation Δβ of the tie bar 4 from the mold touch position to the mold clamping completion position changes,
The mold clamping force F changes.

The distance between the end housing 3 and the cross rod 11 and the length of the toggle link 8 at that time have a certain functional relationship. In addition, when the thickness of the molds 15 and 16 is constant, the length of the toggle link 8 when it is at the mold touch position and the magnitude of the mold clamping force generated when the mold is clamped from that position. Both have a certain functional relationship.

Therefore, in order to generate a desired amount of mold clamping force, the end must be adjusted so that the length of the toggle link 8 when it is in the mold touch position corresponds to the mold clamping force. All that is required is to adjust the position of the housing 3. That is, the positions of the end housing 3 and the cross rod 11 at the time of starting mold clamping may be determined respectively.

Therefore, in the past, the mold clamping force obtained when the mold was clamped from different mold touch positions was determined, and
The mold touch position, that is, the position of the cross rod 11 relative to the end housing 3 at the time of starting mold clamping is determined in accordance with the desired magnitude of mold clamping force.

(Problem to be Solved by the Invention) However, if the position of the cross rod 11 at the start of mold clamping with respect to the end housing 3 to generate a certain magnitude of mold clamping force is constant, the toggle link 8 at that time The length, that is, the distance between the end housing 3 and the movable platen 7 is constant. On the other hand, mold 15゜1
When the thickness of the movable platen 7 changes by replacing the platen 6, the distance between the movable platen 7 and the fixed platen 2 becomes different. Therefore, the effective length β of the tie bar 4 changes depending on the total thickness of the molds 15 and 16 used, that is, the mold thickness.

When the effective length ρ of the tie bar 4 changes, the resulting mold clamping force F also changes, as is clear from the above equation. As a result, a difference occurs between the actually exerted mold clamping force and the set mold clamping force, making it impossible to obtain accurate mold clamping force.

For this reason, a graph such as that shown in Fig. 5 is drawn to show the relationship between the amount of movement of the end housing 3, that is, the number of rotations of the tie bar nut 5, and the amount of change in mold clamping force that changes accordingly, for each mold thickness. Molds made and used 15
, 16, the mold clamping force is corrected by manually rotating the tie bar nuts 5 according to the thickness of the molds.

However, even if such correction is made, it is difficult to precisely adjust the mold clamping force. Also, recently,
Injection molding machines are also required to produce a wide variety of products in small quantities, and molds are being replaced more frequently. In such a case, if the mold clamping force is corrected by manually rotating the tie bar nut 5, the problem is that the work efficiency is poor. Furthermore, such manual adjustment of the mold clamping force cannot meet the recently increasing demand for full automation of injection molding machines.

The present invention was made in view of such problems, and its purpose is to enable a toggle type mold clamping device by setting the thickness of the mold to be used and the desired magnitude of mold clamping force. It is an object of the present invention to provide a method and a device for generating mold clamping force as set.

Another object of the present invention is to enable accurate adjustment of mold clamping force in a toggle injection molding machine even by remote control.

(Means for Solving the Problem) In order to achieve this objective, the mold clamping force adjustment method of the present invention performs a predetermined calculation based on the desired magnitude of mold clamping force and the thickness of the mold used. By doing this, the distance between the crosshead and the end housing at the start of mold clamping, which is necessary to generate the desired mold clamping force, is determined, and the crosshead is moved relative to the end housing according to the calculation result. At the same time, the molds are brought into contact with each other in this state.

In addition, the mold clamping force adjusting device of the present invention that implements the method includes mounting a position detector and an actuating member for actuating the position detector and the actuating member on the end housing and the crosshead, respectively, and at least one of the position detector and the actuating member. The tie bar is characterized in that the position of the tie bar can be adjusted in the axial direction, and that the adjustable position detector or actuating member is moved by a programmable controller. The programmable controller includes a mold clamping force setting device that can set a desired mold clamping force value, a mold thickness setting device that can set the thickness of the mold to be used, and settings set in these setting devices. It is equipped with a calculator that calculates the distance between the end housing and the crosshead at the start of mold clamping in order to generate a desired mold clamping force based on the value, and the distance between the end housing and the crosshead is calculated based on the value obtained by the calculator. It is assumed that the position detector or its operating member is moved.

(Function) With this configuration, according to the method of the present invention, a mold touch position that takes into account the thickness of the mold to be used is determined, and the end housing and crosshead are positioned accordingly. With this, the toggle type mold clamping device can generate accurate mold clamping force regardless of the mold thickness.

Further, according to the device of the present invention, when the desired magnitude of mold clamping force and the thickness of the mold to be used are set in the programmable controller, a predetermined calculation is performed by the controller, and the end housing or crosshead is The attached position detector or its actuating member moves by a distance corresponding to the calculated value. Therefore, by moving the crosshead relative to the end housing to a position where the position detector is activated by the actuating member, and positioning the end housing so that the molds are in contact with each other in that state, the desired mold clamping force can be obtained. It becomes a state that occurs. That is, by simply setting the desired magnitude of mold clamping force and the thickness of the mold to be used, the toggle type mold clamping device can be adjusted to a state that generates the desired mold clamping force.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

In the drawings, FIG. 3 is a side view of the main parts of an embodiment of the mold clamping force adjusting device according to the present invention, and FIG. 4 is an explanatory view showing the adjusted state thereof. Note that the toggle type mold clamping device to which this mold clamping force adjustment device is applied is the same as that explained with reference to Fig. 1.2, so in the following explanation, the first and second mold clamping devices will be used.
Figures will also be used.

As shown in Figure 1.2, the end housing 3
A pedestal 20 is fixed to the arm 3a. on the other hand,
The cross head 11 of the toggle link 8 has its frame 20.
A cam 21 projecting toward the side is fixed.

As is clear from FIG. 3, a stepping motor 22 having an output shaft in the vertical direction is installed on the pedestal 20. A linear head 23 is attached to the output shaft of the stepping motor 22, and as the motor 22 rotates, a shaft 24 of the linear head 23 is driven in the axial direction of the tie bar 4.

A lever 25 that projects in the vertical direction is attached to the tip of the linear head shaft 24. And that lever 2
5, a position detector 26 such as a limit switch is attached. Therefore, the position detector 26 moves in the axial direction of the tie bar 4 as the stepping motor 22 rotates, and its position is adjusted. This position detector 26 is operated by a cam 21 fixed to the cross rod 11. That is, the cam 21 serves as an operating member that operates the position detector 26.

A reference point position detector 27 is attached to the lower part of the lever 25. This reference point position detector 27 is
The reference point cam 28 is fixed at zero. This reference point cam 28 moves the rod 11 to the end housing 3 until the toggle link 8 is fully extended, while preventing mold clamping force from acting.
When the lever 25 is moved in the axial direction of the swivel 4, the position detector 26 and It is installed at a position where the reference point position detector 27 and the reference point position detector 27 operate simultaneously. Then, the position of the position detector 26 when the reference point position detector 27 is operated by the reference point cam 28 (the position shown in FIG. 3) is as follows.
This is the reference position of the position detector 26.

The stepping motor 22 is driven while being controlled by a programmable controller 29. This controller 29 includes a mold clamping force setter 30 that can set a desired mold clamping force value, and a mold 15 to be used.
, 16, that is, the mold thickness, and a calculator 32 that performs predetermined calculations based on the set values set in these setting devices 30, 31. , the motor 22 is driven to rotate in accordance with the calculated value obtained by the calculating unit 32. Arithmetic unit 32
In this case, the length of the toggle link 8 at the start of mold clamping, which is necessary to generate a mold clamping force of a set magnitude, is determined by taking into account the set mold thickness, and the length of the toggle link 8 is determined by taking into account the set mold thickness. The position of the cross rad 11 with respect to the end housing 3 is calculated so that the end housing 3 is aligned with the end housing 3. In this way, the position detector 26 is moved from the reference position by the distance calculated by the calculator 32.

Next, a procedure for adjusting the mold clamping force adjusting device configured as described above so that a desired mold clamping force is generated by the toggle type mold clamping device will be described.

First, with the molds 15 and 16 removed, the toggle link 8 is completely extended. Then, by rotating the tie bar nut 5, the position of the end housing 3 is adjusted so that the distance between the movable platen 7 and the fixed platen 2 is smaller than the total thickness of the molds 15 and 16 by more than 10 mm. do. The position detector 26 is set at a reference position as shown in FIG.

Next, the mold clamping cylinder 13 is operated at low pressure to contract the piston rod 14 and move the movable platen 7 back toward the end housing 3 side. Then, a fixed mold 15 and a movable mold 16 are attached to the fixed plate 2 and the movable plate 7, respectively. Thereafter, the mold clamping cylinder 13 is operated at low pressure to cause the piston rod 14 to protrude, and the movable platen 7 is moved forward toward the fixed platen 2 side. Then, the fixed mold 15 and the movable mold 16
touch each other.

In this state, the toggle link 8 is contracted by the difference between the initially set distance between the movable platen 7 and the fixed platen 2 and the actual mold thickness. Therefore, the toggle link 8 is in a considerably contracted state, and the cam 21 attached to the cross rod 11 is in the position to obtain the maximum mold clamping force, as shown by the imaginary line in FIG. It is located at a position further closer to the end housing 3 than the adjusted position of the detector 26.

In this state, the desired mold clamping force value and the mold thickness of the molds 15 and 16 to be used are set in the mold clamping force setting device 30 and mold thickness setting device 31 of the controller 29, respectively. Then,
Based on these set values, the mold touch position for generating the desired mold clamping force, that is, the distance between the cross rod 11 and the end housing 3, is calculated by the calculator 32, and the controller 29 calculates the mold touch position. A pulse is emitted according to the value. Then, the stepping motor 22 is driven by the pulse. As a result, the linear head shaft 24 moves in the axial direction of the tie bar 4 toward the end housing 3, and the lever 25 at its tip moves to the left in FIG. 3. The moving distance has a predetermined magnitude that is a function of the magnitude of the set mold clamping force and the thickness of the molds 15 and 16.

The position detector 26 thus moves from the position shown in FIG. 3 to the position shown in solid lines in FIG.

Next, in this state, an extremely low pressure is applied to the mold clamping cylinder 13 to press the rod 11 against the cross with a minute force, and the tie bar nut 5 is rotated to move the end housing 3 back in a direction away from the fixed platen 2. By doing so, the position of the end housing 3 can be adjusted while keeping the molds 15 and 16 in complete contact with each other. Then, as shown by the solid line in FIG. 4, when the position detector 26 is activated by the cam 21 fixed to the crosshead 11, the movement of the end housing 3 is stopped.

At this time, the length of the toggle link 8 becomes a predetermined length that can generate the set mold clamping force. That is, this completes the adjustment of the mold clamping force. FIG. 1 shows this state.

From this state, when high pressure is applied to the mold clamping cylinder 13 to cause the piston rod 14 to protrude to its stroke end, the toggle link 8 is completely extended as shown in FIG. Then, a desired mold clamping force is generated thereby.

Furthermore, by using this mold clamping force adjustment device, the mold clamping force can also be adjusted by the following procedure.

First, the toggle link 8 is fully extended, and in that state, the distance between the fixed platen 2 and the movable platen 7 is
, 16, the position of the end housing 3 is adjusted by rotating the tie bar nut 5.

Then, a fixed mold 15 and a movable mold 16 are attached to the fixed platen 2 and the movable platen 7, respectively. At this time, the fixed mold 15 and the movable mold 16 are separated from each other.

Next, the tie bar nut 5 is rotated by the end housing moving device while the toggle link 8 is kept fully extended, and the end housing 3 is advanced toward the fixed platen 2 side. Then, the movable mold 16 comes into contact with the fixed mold 15, and these are completely in close contact with each other. In this way, molds 15, 16
If they come into close contact with each other, a large resistance is applied to the further advancement of the end housing 3, so that an overcurrent is generated in the motor that rotates the tie bar nut 5. Therefore, the overcurrent is detected by a detector, the motor is stopped, and the rotation of the tie bar nut 5 is stopped.

This state is the mold clamping point. Therefore, the position detector 26 is positioned at the reference position shown in FIG. 3 so that the position detector 26 is operated by the cam 21 at this time.

Next, the toggle link 8 is contracted to separate the movable mold 16 from the fixed mold 15. Then, the desired mold clamping force value and the thickness of the mold 15, 16 are set in the controller 29.

As a result, the position detector 26 moves from the reference position in the axial direction of the tie bar 4 by a predetermined amount that is in a functional relationship with the set magnitude of the mold clamping force and the mold thickness of the molds 15 and 16. It is adjusted to the position shown by the solid line in the figure.

In this state, low pressure is applied to the mold clamping cylinder 13 to move the rad 11 to the cross at a very low speed. When the cam 21 fixed to the cross rad 11 operates the position detector 26, the movement of the cross rad 11 relative to the end housing 3 is stopped. In this way, the cross plate 11 is positioned at a mold touch position corresponding to the thickness of the molds 15, 16 used.

Thereafter, the tie bar nut 5 is rotated and the end housing 3 is moved while maintaining this state until the molds 15 and 16 come into contact with each other.

As a result, the state shown in FIG. 1 is reached, and the adjustment of the mold clamping force is completed.

In this way, the position detector 2
By moving 6, it becomes possible to accurately adjust its position remotely. And mold 1
Detecting the contact state of 5 and 16, tie bar nut 5
It is also possible to easily operate the mold clamping cylinder 13 at a predetermined speed remotely. therefore,
By adjusting the mold clamping force as described above,
It becomes possible to accurately adjust the mold clamping force by remote control. Furthermore, by simply setting the desired mold clamping force and the thickness of the molds 15 and 16 to be used in the controller 29, the toggle type mold clamping device will apply the desired mold clamping force according to the mold thickness. Since the mold clamping force is adjusted to a state that can occur, there will be no difference between the set mold clamping force and the mold clamping force that is actually generated.

In the above embodiment, the position detector 26 provided on the end housing 3 side is moved, but this position detector 26 is fixed and the cam 21 on the Rad 11 side is moved to the cross instead. It can also be moved. Alternatively, the cam 21 may be attached to the end housing 3 side, and the position detector 26 may be installed to the crosshead 11 side.

As the position detector 26, in addition to a limit switch, an optical sensor or the like may be used. In such a case, as an actuating member for actuating the position detector 26,
Something other than cam 21 may be used.

Furthermore, the mold clamping force adjustment method according to the present invention is not necessarily carried out only using the mold clamping force adjustment device as described above. For example, in the latter of the mold clamping force adjustment procedures described above, when determining the mold touch position of the crosshead 11 after adjusting the mold clamping force point, after opening the mold 15° 16, The end housing 3 is positioned by rotating the tie bar nut 5 by the required number of rotations, and then the mold is closed to bring the molds 15 and 16 into close contact with each other, thereby positioning the rod 11 crosswise with respect to the end housing 3. You can also do it. In that case, the required number of rotations of the tie bar nut 5 can be calculated based on the magnitude of the desired mold clamping force and the thickness of the molds 15 and 16 used, and the position detector 26 and the cam 2
1st prize is no longer needed.

(Effects of the Invention) As is clear from the above description, according to the present invention, based on the desired mold clamping force value and the thickness of the mold used,
Since the positions of the end housing and the crosshead at the start of mold clamping are determined, there is no difference in actual mold clamping force due to differences in the thickness of the molds used. Therefore, the mold clamping force as set is generated, and precise injection molding becomes possible.

Further, since the positioning of the crosshead with respect to the end housing is performed by a programmable controller having a computing unit, it is possible to accurately adjust the mold clamping force by remote control. Therefore, the work efficiency and accuracy are improved, and even when the molds are replaced frequently, it becomes possible to easily cope with the situation.

Furthermore, if the programmable controller is connected to the central controller of the injection molding machine, it will be possible to set the optimal mold clamping force according to the thickness of the mold when replacing the mold. In addition to fully automating mold exchange, it is also possible to control the injection molding machine with high precision.

[Brief explanation of the drawing]

Fig. 1 is a partially vertical side view showing an example of a toggle type mold clamping device of an injection molding machine to which the mold clamping force adjustment device according to the present invention is applied, and Fig. 2 is a mold clamping device of the toggle type mold clamping device. A similar side view showing the completed state; FIG. 3 is a side view of essential parts showing an embodiment of the mold clamping force adjusting device according to the present invention; FIG. 4 is an explanation of the adjustment procedure in the mold clamping force adjusting device. FIG. 5 is a graph for correcting the clamping force used in the conventional clamping force adjustment method. 1...Bed 2...Fixed plate 3...
・End housing 4... Tie bar 5... Tie bar nut 7 River movable plate 8... Toggle link 11... Cross head 13... Mold clamping cylinder 15... Fixed mold 16... Movable mold 21...Cam (operating member) 22...Stepping motor 23...Linear head 26...Position detector 29...Programmable controller patent applicant Japan Steel Works, Ltd.

Claims (4)

[Claims] (1) It has a toggle link that expands and contracts by moving the crosshead with respect to the end housing, and when the toggle link is slightly contracted and the movable mold and the fixed mold are brought into contact with each other, the said cross In a toggle type injection molding machine that generates mold clamping force by moving the head and fully extending the toggle link; the desired magnitude of mold clamping force and the movable mold and fixed mold used; Based on the thickness of the mold, calculate the distance between the cross head and the end housing at the start of mold clamping in order to generate the desired mold clamping force, is the value obtained by the calculation, and in that state, the movable mold and the fixed mold are positioned so that they are in contact with each other. (2) The positioning of the cross head and the end housing is carried out after the movable mold and the fixed mold are brought into contact, and while maintaining that state, the distance between the cross head and the end housing is determined by the calculated value. The mold clamping force adjustment method according to claim 1, wherein the mold clamping force adjustment method is performed by moving the end housing so that (3) After positioning the crosshead and the end housing with respect to the end housing such that the distance therebetween is the calculated value,
2. The mold clamping force adjustment method according to claim 1, wherein the end housing is moved while maintaining this state until the movable mold comes into contact with the fixed mold. (4) Distance between a fixed plate fixed to a bed to which a fixed mold is attached, and a fixed plate connected to the fixed plate via a plurality of tie bars and movably supported by the bed. a movable platen that is movably supported by the tie bar between the fixed platen and the end housing, and to which a movable mold opposing the fixed mold is attached; a toggle link that connects to the end housing and expands and contracts by moving the crosshead in the axial direction of the tie bar to move the movable platen with respect to the end housing; ; a position detector and an actuating member for actuating the position detector on the end housing and the crosshead, respectively;
A mold clamping force setting device, at least one of which is installed so that the position thereof can be adjusted in the axial direction of the tie bar, and which can set a desired mold clamping force value, and the total of the fixed mold and the movable mold. A mold thickness setter capable of setting the thickness, and a mold thickness setting device between the end housing and the crosshead at the start of mold clamping for generating a desired mold clamping force based on the setting values set in these setting devices. A mold in a toggle type injection molding machine, comprising a calculator for calculating a distance, and a programmable controller that moves at least one of the position detector and the actuating member according to the calculated value obtained by the calculator. Tightening force adjustment device.