JP2011093263A - Mold clamping device and method of controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold clamping device allowing easy manufacturing of not only moldings of a simple shape but also those of a complicated shape and achieving uniformity of the thickness of moldings, and its control method. <P>SOLUTION: The clamping device includes a control device which drives a plurality of driving devices individually by giving a command value or a target value to each of the driving devices and thereby causes a plurality of tie bars corresponding to the individual driving devices to operate independently to move a moving board. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a mold clamping device used in an injection molding machine and a control method thereof.

Conventionally, when a material mixed with a foamable material, also called a foam material, is molded, an operation called a core back is performed as one of the molding processes. The core back refers to an operation for opening the mold (mold opening operation) when most of the material injected and filled in the cavity of the mold is in a molten state.

Here, to briefly explain the injection molding cycle including the core back, a mold clamping process is first performed. Next, an injection process is performed. Next, a core back process (also referred to as a mold opening process) is performed. Next, a pressure holding and cooling process is performed. Next, a mold opening process is performed. Next, a product removal process is performed. An injection molding cycle is formed by repeating the above steps in order.

In particular, in the core back process, an operation called core back is performed. In the operation of the core back, a conventional mold clamping device having four sets of hydraulic mold clamping cylinders is used, and by a synchronous rotation (also referred to as synchronous drive) of a servo motor provided so as to protrude outside the mold clamping cylinder, The mold opening is realized while controlling the mold opening speed of the moving mold via the rams of the two diagonal hydraulic clamping cylinders.

Thereby, the expansion rate of the foam material is controlled. Here, the expansion rate is the expansion rate when the foam material expands and expands.

In addition, a position sensor is attached to each of a plurality of tie bars, and using these position sensors, when the core back is in operation (also referred to as core back), when the tie bar travel distance reaches the specified travel distance, synchronous drive At the same time as stopping the servo motors, the rams of the hydraulic clamping cylinders are individually stopped at predetermined positions using the on-off valves provided in the respective hydraulic clamping cylinders. By maintaining parallelism, uneven thickness of the molded product is prevented. (For example, refer to Patent Document 1).

In addition to the above, the following can be provided as a mechanism for preventing the thickness deviation of the molded product by keeping the fixed die plate and the movable die plate parallel to each other as described above. Are known.

In an injection compression molding machine having a mold opening / closing means using an electric servo motor and a ball screw device, and a mold clamping means using a hydraulic cylinder, the relative position detection sensor of the fixed die plate and each tie bar during the compression mold clamping process of the movable die plate. Using the detected value, the flow rate of hydraulic oil is controlled by a hydraulic servo valve so that it matches the position of the moving die plate converted from the number of rotations of the ball screw of the moving die plate moving means, and the clamping cylinder is operated. In addition, the movable die plate is held in parallel to produce a molded product with a uniform thickness by performing parallel movement control so that the other mold clamping cylinder follows the specific mold clamping cylinder. . (For example, refer to Patent Document 2).

JP 2005-342935 A JP 2003-181895 A

However, in the method of realizing the operation of the core back as described above, the two hydraulic die clamping cylinders are operated by using one of the two diagonal hydraulic clamping cylinders by utilizing the synchronous drive of the servo motor. In molds that mold complex molded products, it is difficult to control the appropriate expansion and expansion rate for the foam material, and good molded products can be obtained. It may not be possible.

Further, in the method of maintaining the parallel of the fixed die plate and the movable die plate as described above, the parallel of the fixed die plate and the movable die plate can be maintained during the core back operation or the compression mold clamping operation. However, the plane where the movable mold and the stationary mold form a cavity, that is, the plane where the movable mold and the stationary mold are in contact with each other, does not always satisfy the parallel condition.

However, the compression mold clamping operation is the opposite of the core back operation, and the material is injected and filled into the mold cavity that is opened from the mold closing limit by an appropriate amount according to the mold and material. This is an operation of clamping a mold that has been opened by an appropriate amount while most of the material is in a molten state (clamping the mold).

Therefore, high-precision mold cleaving operation or compression mold for a moving or fixed plate that does not have parallelism on the surface to which the mold is attached due to deterioration due to aging, etc., or a mold that does not have parallelism. In some cases, the tightening operation cannot be realized, and a thickness deviation appears in the molded product.

However, the term “parallelism” as used herein means that there is a tilt or unevenness or depression within an allowable range when the injection molding machine is sufficiently safe during the injection molding cycle operation. If there is an excessive inclination or unevenness or depression exceeding the allowable range, it is not assumed.

Therefore, the present invention makes it possible to easily manufacture not only a molded product having a simple shape but also a molded product having a complicated shape, and a mold clamping device capable of making the thickness of the molded product uniform. An object is to provide a control method thereof.

In order to achieve the above object, the present invention is characterized by the following configurations and methods.

(1) A mold clamping device according to one aspect of the present invention includes a stationary platen, a plurality of tie bars attached to the stationary plate so as to freely advance and retreat, a plurality of driving devices for moving the plurality of tie bars back and forth, and the plurality of the plurality of tie bars. A movable board that can move forward and backward along the tie bar, a fixing mechanism that detachably fixes the movable board to the plurality of tie bars, and a control device. By giving separate command values or target values to a plurality of driving devices, the plurality of driving devices are individually driven, and accordingly the plurality of tie bars corresponding to the plurality of driving devices are individually operated. The moving board is moved.

(2) The mold clamping device control method according to one aspect of the present invention is configured to individually drive the plurality of driving devices by giving different command values or target values to the plurality of driving devices, respectively. Accordingly, a plurality of tie bars corresponding to each of the plurality of driving devices are individually operated and controlled to move the movable board.

According to the present invention, since it can be controlled according to the expansion speed and injection pressure of the material, not only a molded product having a simple shape but also a molded product having a complicated shape can be easily manufactured.

In addition, a molded product having a uniform thickness can be manufactured regardless of the surface accuracy of the surface on which the mold of the movable platen or fixed plate is mounted and the surface accuracy of the mold.

The top view which shows the mold clamping apparatus which concerns on the form of 1st Example by this invention in a partial cross section. The flowchart figure which represented simply the injection molding cycle including a core back process. The flowchart figure which represented simply the injection molding cycle including a core back process and a compression mold clamping process. The flowchart figure showing the core back process simply. Sectional drawing which shows the engagement state at the time of engagement of the half nut and tie bar which were integrated in the mold clamping apparatus shown by FIG. Sectional drawing which shows the engagement state at the time of the mold clamping of the half nut shown in FIG. 5, and a tie bar. Sectional drawing which shows the engagement state at the time of the core back of the half nut shown in FIG. 5, and a tie bar. The flowchart figure which represented simply the injection molding cycle including a compression mold clamping process. The flowchart figure which represented the compression mold clamping process simply.

A first embodiment according to the present invention will be described below with reference to the drawings applied to a mold clamping device of an injection molding machine.

First, the structure of the mold clamping apparatus which is the form of the 1st Example by this invention is demonstrated.

FIG. 1 discloses a mold clamping device 11 according to a first embodiment of the present invention.

As shown in FIG. 1, the mold clamping device 11 includes a fixed platen 13, four tie bars 14a, 14b, 14c, 14d as main components, and four tie bar driving servomotors 15a, 15b, 15c, 15d as driving devices. The moving board 16, the mold opening / closing servo motor 17, four half nuts 18 a, 18 b, 18 c, 18 d as a fixing mechanism, and a control device 20 are provided.

A fixed mold 25 is attached to the front surface of the fixed platen 13. Here, the front surface of the fixed platen 13 is a surface on the side facing the movable platen 16. Four tie bars 14a, 14b, 14c, and 14d are attached to the fixed platen 13 so as to freely advance and retract.

Further, inside the stationary platen 13, hydraulic die clamping cylinders 26a, 26b, 26c, and 26d are provided for each of the four tie bars 14a, 14b, 14c, and 14d.

Specifically, the four tie bars 14a, 14b, 14c, and 14d have piston portions 27a, 27b, 27c, and 27d at the respective base end portions. The piston portions 27a, 27b, 27c, and 27d are attached to the hydraulic clamping cylinders 26a, 26b, 26c, and 26d.

As a result, two cylinder chambers of the mold clamping side chamber 28a and the mold opening side chamber 29a are formed inside the single hydraulic mold clamping cylinder 26a with the piston portion 27a interposed therebetween. The hydraulic mold clamping cylinders 26b, 26c, and 26d are the same as the hydraulic mold clamping cylinder 26a.

When hydraulic oil is supplied to the mold clamping side chamber 28a, the tie bar 14a moves backward, and when hydraulic oil is supplied to the mold opening side chamber 29a, the tie bar 14a moves forward.

Here, the backward movement of the tie bar 14a means that the tie bar 14a moves in the direction in which the movable platen 16 approaches the fixed platen 13 in FIG. 1, and the forward movement of the tie bar 14a means that the tie bar 14a moves in the movable platen 16 in FIG. Is to move away from the fixed platen 13.

Similarly, in the mold clamping side chambers 28b, 28c, 28d and the mold opening side chambers 29b, 29c, 29d, when hydraulic oil is supplied to the side chambers, the corresponding tie bars 14b, 14c, 14d move forward or backward. To do.

Further, engaging grooves 24a, 24b, 24c, and 24d made of saw teeth, threads, or annular grooves are provided on the outer peripheral surfaces of the tie bars 14a, 14b, 14c, and 14d, respectively.

On the back surface of the fixed platen 13, partition walls 31a, 31b, 31c, and 31d are attached to the four tie bars 14a, 14b, 14c, and 14d, respectively. Here, the back surface of the stationary platen 13 is a surface on the side opposite to the front surface of the stationary platen 13.

The base end portion of the piston portion 27a of the tie bar 14a penetrates and projects through the partition wall 31a. The nut part 32a is attached to the axial center part of the site | part which penetrated the partition wall 31a of the piston part 27a.

The nut portion 32a constitutes a part of the ball screw 33a. In addition, nuts 32b, 32c, 32d and ball screws 33b, 33c, 33d are similarly configured for the partition walls 31b, 31c, 31d.

In the partition wall 31a, a positioning box 34a is attached to the surface opposite to the surface to which the hydraulic clamping cylinder 26a is attached.

A bearing 36a is mounted on the rear surface of the positioning box 34a coaxially with the piston portion 27a.

Here, the back surface of the positioning box 34a is a surface on the opposite side to the surface attached to the partition wall 31a in FIG.

A screw shaft 37a of a ball screw 33a is rotatably supported on the bearing 36a. The same applies to the partition walls 31b, 31c, and 31d.

A screw portion 22a is provided at the tip of the screw shaft 37a. The screw portion 22a is screwed into the nut portion 32a.

The base end portion of the screw shaft 37a protrudes from the back surface of the positioning box 34a. A driven pulley 38a is attached to the protruding portion.

A tie bar driving servomotor 15a is attached to the outside of the positioning box 34a.

The tie bar driving servomotor 15a is provided with a driving pulley 39a. A timing belt 41a is stretched between the driving pulley 39a and the driven pulley 38a.

The same applies to the driven pulleys 38b, 38c, 38d, the drive pulleys 39b, 39c, 39d, and the timing belts 41b, 41c, 41d.

Accordingly, when the tie bar driving servo motor 15a is driven, the screw shaft 37a of the ball screw 33a rotates via the driving pulley 39a and the driven pulley 38a.

The rotational motion of the screw shaft 37a is converted into linear motion of the piston portion 27a via the nut portion 32a.

That is, by driving the tie bar driving servo motor 15a, the tie bar 14a can be advanced and retracted. The same applies to the tie bars 14b, 14c, and 14d.

The movable board 16 is provided so as to face the fixed board 13 through four tie bars 14a, 14b, 14c, and 14d.

The movable platen 16 can advance and retreat in a direction approaching or moving away from the fixed platen 13 along the tie bars 14a, 14b, 14c, and 14d.

A moving mold 42 is provided on the front surface of the moving board 16. Here, the front surface of the movable platen 16 is a surface facing the fixed platen 13.

The moving mold 42 is attached to the front surface of the moving board and faces the fixed mold 25. A cavity 43 is formed between the fixed mold 25 and the movable mold 42 by contacting the mold surfaces of the movable mold 42 and the fixed mold 25.

A nut portion 45 is fixed to the side surface of the moving plate 16. The mold opening / closing servomotor 17 is attached to the fixed platen 13 via a bracket (not shown).

A screw shaft 47 is attached to the rotation shaft of the mold opening / closing servomotor 17. The screw shaft 47 has a screw portion 21. The screw part 21 is screwed into the nut part 45. The screw shaft 47 and the nut portion 45 constitute a ball screw 48.

Therefore, when the mold opening / closing servomotor 17 is driven, the screw shaft 47 rotates. The rotational movement of the screw shaft 47 is converted into a linear movement of the moving board 16 via the nut portion 45.

That is, by driving the mold opening / closing servomotor 17, the movable board 16 can be moved back and forth. As a result, the movable mold 42 approaches or separates from the fixed mold 25, so that the mold opening / closing operation can be performed.

Half nuts 18 a, 18 b, 18 c, 18 d are attached to the rear surface of the moving board 16.

The half nut 18a is engaged with and disengaged from the engagement groove 24a of the tie bar 14a. The half nut 18 a is driven in the radial direction by the open / close cylinder 51.

When the half nut 18a is driven in a direction in which the half nut 18a meshes with the engagement groove 24a, a part of the moving plate 16 is fixed by the tie bar 14a.

When the half nut 18a is driven in a direction in which the half nut 18a is disengaged from the engagement groove 24a, a part of the moving plate 16 is fixed by the tie bar 14a.

The same applies to the half nuts 18b, 18c, and 18d. The movable board 16 can be moved along the four tie bars 14a, 14b, 14c, and 14d when the fixation with the four tie bars 14a, 14b, 14c, and 14d is released.

The control device 20 is connected to the tie bar driving servomotors 15 a, 15 b, 15 c, and 15 d and the mold opening / closing servomotor 17 via the wiring 53.

The control device 20 transmits control signals to the tie bar driving servomotors 15 a, 15 b, 15 c, 15 d and the mold opening / closing servomotor 17 via the wiring 53.

Accordingly, the tie bar driving servomotors 15a, 15b, 15c, 15d and the mold opening / closing servomotor 17 are controlled by the control device 20.

From here, the structure of the mold-clamping apparatus in the form of the 1st Example especially relevant to this invention is demonstrated.

The controller 20 gives the tie bar drive servomotors 15a, 15b, 15c, 15d to the four tie bar drive servomotors 15a, 15b, 15c, 15d by giving different command values or target values to the four tiebar drive servomotors 15a, 15b, 15c, 15d, respectively. The tie bars 14a, 14b, 14c, and 14d corresponding to the tie bar driving servomotors 15a, 15b, 15c, and 15d are individually operated.

Then, the movable board 16 is moved backward through the tie bars 14a, 14b, 14c, and 14d.

Here, the backward movement of the movable platen 16 means moving in a direction away from the fixed platen 13 in FIG. Further, the forward movement of the moving plate 16 means that the moving plate 16 moves in a direction approaching the fixed platen 13 in FIG.

The control device 20 also has a core back setting device (not shown), a display (not shown), a buzzer (not shown), and a lamp such as a patrol light (not shown).

In the core back setting device, the operating speed of each tie bar at the time of core back, the operating force of each tie bar at the time of core back, the correction amount of each tie bar position at the time of core back, the operating amount at the time of core back, The start position of the core back is provided as a setting item.

Further, the control device 20 has a main storage device, auxiliary storage device or central processing unit (not shown), and all settings necessary for performing an injection molding cycle such as set values set by the core back setting device. Data (this setting data includes the correction amount for the movement amount of each tie bar at the time of core back and data indicating the range of the correction) can be stored and saved in a main storage device or auxiliary storage device (not shown). it can.

The stored data can be easily recalled from a main storage device or auxiliary storage device (not shown).

Furthermore, in the main storage device or auxiliary storage device (not shown) of the control device 20, not only setting data but also measurement data measured during the injection molding cycle operation and data taken in as good product data can be stored and stored. it can.

In addition, setting data, measurement data, and non-defective product data stored in a main storage device or auxiliary storage device (not shown) of the control device 20 are converted into numerical data or converted into waveforms by a display (not shown) provided in the control device 20. Can be displayed.

The above is description about the structure of the mold clamping apparatus in the form of 1st Example especially relevant to this invention.

Next, the configuration of the mold clamping device control method according to the first embodiment of the present invention will be described.

A molded product made by injection molding is molded by performing an injection molding cycle S78.

Specifically, first, as a preparation for entering the injection molding cycle S78, a mold attaching operation S70 and a mold thickness adjusting operation S71 for the fixed mold 25 and the movable mold 42 are performed.

Then, as shown in FIG. 2, the mold clamping step S72, the injection step S73, the core back step S74, the pressure holding and cooling step S75, the mold opening step S76, and the product takeout step S77 are repeated in this order to form an injection molding cycle S78. .

However, in the mold clamping step S72, the mold closing operation is performed by a drive device other than hydraulic pressure such as electric drive and the mold clamping operation is performed by hydraulic drive in the mold clamping step S72. It may be performed separately from the mold clamping operation.

The core back step S74 is performed after the injection step S73 due to the nature of the core back. As an application, the core back step S74 is performed before the injection step S73, that is, after the mold clamping, the mold opening operation is performed. There is also a control method including a core back process S74 and a compression mold clamping process S79, in which injection is performed next, mold clamping is performed again, operation after holding pressure and cooling is performed, and an injection molding cycle S78 is performed.

Here, the compression mold clamping process is a process of performing a compression mold clamping operation.

Specifically, as shown in FIG. 3, first, as preparation for entering the injection molding cycle S78, a mold attaching operation S70 and a mold thickness adjusting operation S71 for the fixed mold 25 and the movable mold 42 are performed.

Then, by repeating the mold clamping step S72, the core back step S74, the injection step S73, the compression mold clamping step S79, the pressure holding and cooling step S75, the mold opening step S76, and the product takeout step S77, an injection molding cycle S78 is obtained. .

Here, the structure of the control method of the mold clamping device in the form of the first embodiment particularly related to the present invention will be described.

Here, focusing on the core back step S74, description will be made with reference to FIG. First, as shown in FIG. 4, as preparation for the core back step S74, the core back condition S80 is set after the mold thickness adjusting operation S71.

The core back condition S80 defines how the core back is operated. In this embodiment, the operating speed of each tie bar during the core back and the operating force of each tie bar during the core back The correction amount of each tie bar position at the time of core back, the operation amount at the time of core back, and the start position of the core back can be set.

Then, in the core back step S74, from the core back start S81, the mold opening operation S82 is performed based on the core back condition S80, and the operation is terminated at the core back completion S83 every injection molding cycle S78.

The above is description about the structure of the control method of the mold clamping apparatus in the form of 1st Example especially related to this invention.

Next, the operation of the first embodiment according to the present invention will be described.
Specifically, it demonstrates using the mold clamping apparatus 11 below.

First, the parallelism of the mold mounting surface of the movable platen 16, the parallelism of the mold mounting surface of the fixed platen 13, the parallelism of the surface facing the fixed platen 13 of the fixed die 25 and the back surface thereof, The parallelism between the surface of the moving mold 42 facing the moving plate 16 and the surface of the back surface thereof is measured.

Next, a mold attaching operation S70 and a mold thickness adjusting operation S71 for the fixed mold 25 and the moving mold 42 are performed.

Specifically, the mold opening / closing servo motor 17 is driven to move the moving plate 16 to the mold closing limit, and the fixed mold 25 and the movable mold 42 are attached.

Here, the mold closing limit means that the fixed mold 25 and the movable mold 42 are attached to the fixed platen 13 and the movable platen 16, respectively. It is the position that touches.

Next, the half nut 18a is engaged with the engagement groove 24a of the tie bar 14a using the opening / closing cylinder 51. Similarly, the half nuts 18b, 18c, 18d are also engaged with the engaging grooves 24b, 24c, 24d of the tie bars 14b, 14c, 14d.

Thereby, the movable board 16 is fixed by the four tie bars 14a, 14b, 14c, and 14d. At this time, as shown in FIG. 5, a gap may be formed between the half nut 18a and the engaging groove 24a of the tie bar 14a.

At this time, as shown in FIG. 5, the half nut 18a and the engagement groove 24a of the tie bar 14a may be properly meshed with each other. However, there is a case where the half nut 18a and the engagement groove 24a are not properly meshed with each other due to a difference in pitch between the two.

In this case, the tie bar driving servo motor 15a is driven to slightly advance the tie bar 14a. As a result, the fixing position of the movable board 16 and the tie bar 14a is adjusted, and the half nut 18a and the engaging groove 24a are properly meshed with each other.

At this time, the position of the tie bar 14a is read by a position sensor (not shown) inside the tie bar driving servo motor 15a, and the position is stored.

In the subsequent mold closing operation in the mold clamping step S72, the driving of the tie bar driving servo motor 15a is controlled so that the tie bar 14a is always in the stored position.

The same applies to the engagement groove 24b between the half nut 18b and the tie bar 14b, the engagement groove 24c between the half nut 18c and the tie bar 14c, and the engagement groove 24d between the half nut 18d and the tie bar 14d. The mold thickness adjusting operation S71 is now complete.

The above operation is within the scope of the conventional invention.

Next, the first operation in the form of the first embodiment particularly related to the present invention will be described.

In the core back setting device, the parallelism of the mold mounting surface of the movable platen 16 measured in advance, the parallelism of the mold mounting surface of the fixed platen 13, the surface of the fixed die 25 facing the fixed platen 13 and the back surface thereof. The parallelism of the surface of the movable mold 42 and the parallelism of the surface facing the moving plate 16 of the moving mold 42 and the back surface thereof, the shape of the cavity 43, the expansion speed of the foam material, the expansion force of the foam material, the injection In consideration of the pressure, the operating speed of each tie bar 14a, 14b, 14c, 14d during core back, the operating force of each tie bar 14a, 14b, 14c, 14d during core back, and each tie bar 14a, during core back The correction amount of the positions 14b, 14c, and 14d, the operation amount at the time of core back, and the start position of the core back are input.

This set value is the difference in expansion speed due to the foam material, the difference in expansion force due to the foam material, the difference in injection pressure, the parallelism of the mold mounting surface of the movable platen 16 measured in advance, the mold of the fixed platen 13. The parallelism of the mounting surface, the parallelism of the surface facing the stationary platen 13 of the fixed mold 25 and the back surface thereof, and the parallelism of the surface facing the movable platen 16 of the movable mold 42 and the rear surface thereof are different. Therefore, it is changed according to the shape of the cavity 43, the material, the injection pressure, and the parallelism of the above-described surface measured in advance.

The above is description of the 1st effect | action in the form of 1st Example especially related to this invention.

Thereafter, the injection molding cycle S78 is started, and the mold clamping step S72 is performed first. The mold clamping step S72 will be described briefly for the scope of the conventional invention.
First, the mold closing operation in the mold clamping step S72 is performed.

Specifically, the mold opening / closing servo motor 17 and the four tie bar driving servo motors 15a, 15b, 15c, 15d are driven to adjust the mold thickness of the movable board 16 and the four tie bars 14a, 14b, 14c, 14d. It is moved to the position stored at the time of work S71.

Next, the half nuts 18a, 18b, 18c, 18d are engaged with the engaging grooves 24a, 24b, 24c, 24d of the tie bars 14a, 14b, 14c, 14d, and the movable board 16 is engaged with the tie bars 14a, 14b, 14c. , 14d.

After the mold closing operation, the mold clamping operation is performed. Specifically, hydraulic oil is supplied to the mold clamping side chamber 28a of the hydraulic cylinder 26a, and the tie bar 14a is moved backward.

As shown in FIG. 6, the engaging groove 24a of the tie bar 14a comes into contact with the half nut 18a, so that the moving board 16 moves according to the tie bar 14a. The tie bars 14b, 14c, and 14d are operated in the same manner. Thereby, the moving mold 42 and the fixed mold 25 are clamped.

Next, an injection step S73 is performed. The injection step S73 is briefly described because of the scope of the conventional invention.

In the injection step S73, the material is injected from the injection nozzle while the movable mold 42 and the fixed mold 25 are clamped. Thereby, the material is filled in the cavity 43. An example of the material is a dissolved resin.

Next, the second action of the first embodiment particularly related to the present invention will be described.

When a foam is mixed with the material, it is desirable to promote foaming of the foam in the cavity 43.

In addition, the mold may be opened by the injection pressure, and the contact surface between the movable mold 42 and the fixed mold 25 may not be parallel.
Therefore, the core back step S74 is performed here.

In the core back step S74, the control device 20 individually drives the tie bar driving servomotors 15a, 15b, 15c, 15d, and each tie bar 14a corresponding to each tie bar driving servomotor 15a, 15b, 15c, 15d. , 14b, 14c, and 14d are individually operated to move the moving board 16 backward.

Specifically, first, the tie bar driving servo motor 15a is driven to advance the tie bar 14a through the ball screw 33a. Then, as shown in FIG. 7, the engagement groove 24a of the tie bar 14a comes into contact with the half nut 18a, so that the moving plate 16 moves according to the tie bar 14a. The same applies to the tie bars 14b, 14c, and 14d.

At this time, each tie bar 14a, 14b, 14c, 14d operates individually at each operating speed at the time of core back determined by the core back setting device and each operating force at the time of core back, and drives each tie bar. The amount of movement at the time of core back and the amount of correction of the tie bar position of each tie bar 14a, 14b, 14c, 14d at the time of core back, based on reading values of position sensors (not shown) inside the servo motors 15a, 15b, 15c, 15d Move each by the combined amount.

For example, the operation amount at the core back is set to 20 [mm], the operation speed at the core back for the tie bar 14a is 1.0 [mm / s], and the operation speed at the core back for the tie bar 14b is 1.5 [mm]. mm / s], the core back operating speed of the tie bar 14c is set to 2.0 [mm / s], and the core back operating speed of the tie bar 14d is set to 0.5 [mm / s].

The core back operating force against the tie bar 14a is 50 [kN], the core back operating force against the tie bar 14b is 70 [kN], the core back operating force against the tie bar 14c is 60 [kN], and the core back against the tie bar 14d. The operating force at the time is set to 40 [kN].

The correction amount of the tie bar position at the time of core back with respect to the tie bar 14a is 0.5 [mm], the correction amount of the tie bar position at the time of core back with respect to the tie bar 14b is 1.0 [mm], The correction amount is set to 0 [mm], and the correction amount of the tie bar position at the time of core back with respect to the tie bar 14d is set to -0.5 [mm].

Then, in the core back step S74, the tie bar 14a moves forward by 20.5 [mm] while being controlled to have an operating speed of 1.0 [mm / s] and an operating force of 50 [kN].

The tie bar 14b moves forward by 21.0 [mm] while being controlled to have an operating speed of 1.5 [mm / s] and an operating force of 70 [kN].

The tie bar 14c moves forward by 20.0 [mm] while being controlled to have an operation speed of 2.0 [mm / s] and an operation force of 60 [kN].

The tie bar 14d advances 19.5 [mm] while being controlled to have an operating speed of 0.5 [mm / s] and an operating force of 40 [kN].

As a result, the movable board 16 is retracted to a predetermined position. Further, the operating speed and operating force of each tie bar 14a, 14b, 14c, 14d at that time are feedback-controlled and controlled while being corrected to be equal to the set value.

At this time, as for the measurement of the operation speed and the operation force of each tie bar 14a, 14b, 14c, 14d, it is only necessary to obtain each operation speed and each operation force, so each tie bar driving servomotor 15a, 15b, 15c. , 15d, and a tie bar driving servo motor 15a, 15b, 15c, 15d, and a tie bar driving servo motor. Measurement is performed using a position sensor (not shown) inside 15a, 15b, 15c, 15d and a speed sensor (not shown) inside each tie bar drive servo motor 15a, 15b, 15c, 15d, and further calculation is performed. May be.

The calculation at that time is an operation using a differentiator using an analog circuit (not shown), an operation using a differentiator using a digital circuit (not shown), or a central operation (not shown) of the control device 20. Computation by difference using processor, main memory or auxiliary memory, computation using differentiator (also called differential filter) by digital circuit (software), or computation using state estimator Is mentioned.

The above is description of the 2nd effect | action in the form of 1st Example especially related to this invention.

After that, a molded product is formed through the pressure holding and cooling step S75. And finally, mold opening process S76 and product taking-out process S77 are performed, and one cycle of injection molding is completed by taking out a molded product. Thereafter, this injection molding cycle is repeated by repeating one cycle of this injection molding.

Here, the third action in the form of the first embodiment particularly related to the present invention will be described.

The movement amount of each tie bar 14a, 14b, 14c, 14d at the time of core back is measured by a position sensor (not shown) in each tie bar driving servo motor 15a, 15b, 15c, 15d, and the measured value is the control device 20. Is stored in a main storage device (not shown) or an auxiliary storage device, and is stored as measurement data of the operation amount of each tie bar 14a, 14b, 14c, 14d.

For each tie bar 14a, 14b, 14c, 14d, the set amount of movement of each tie bar 14a, 14b, 14c, 14d at the time of core back, that is, the amount of movement at the time of core back, and each tie bar 14a, 14b, 14c. , 14d, and an error between the amount obtained by adding the correction amount of each tie bar position and the operation amount measurement data of each tie bar 14a, 14b, 14c, 14d, and the error is eliminated at the core back step S74 of the next cycle. Thus, correction by feedback control is applied.

However, in the correction by the feedback control, a range that can be corrected is determined by setting data stored in a main storage device or an auxiliary storage device (not shown) included in the control device 20, and each tie bar 14a at the time of the set core back is determined. , 14b, 14c, 14d and a display unit (not shown) included in the control device 20 when the error between the movement data of the tie bars 14a, 14b, 14c, 14d exceeds the correctable range. Is displayed as a machine abnormality, a buzzer (not shown) included in the control device 20 emits a sound indicating abnormality, a lamp such as a patrol light (not shown) included in the control device 20 is turned on or blinked, and the abnormality is automatically detected. Is controlled to stop the injection molding cycle upon completion of the injection molding cycle. .

Further, the amount of correction of the tie bar position of each tie bar 14a, 14b, 14c, 14d during core back, the operating speed of each tie bar 14a, 14b, 14c, 14d during core back, and each tie bar 14a, 14b, 14c during core back. , 14d, the amount of movement during the core back, and the start position of the core back are changed each time depending on the material (including the foam material), the mold to be attached, and the injection pressure.

The setting change is not only set from the beginning each time, but is also set by saving the data once set as data in a main storage device or auxiliary storage device (not shown) of the control device 20 and calling the stored data. It can also be changed.

In addition, the above setting may be changed by calling out data when the control device 20 becomes a non-defective product from the data observed at the core back step S74 stored in the main storage device or auxiliary storage device (not shown) included in the control device 20. it can.

Further, here, in the configuration of the mold clamping device control method according to the first embodiment of the present invention, when the control method including the core back process S74 and the compression mold clamping process S79 described as applications is used. The operation of will be described.

In the description here, for the injection molding cycle S78 including the core back step S74, the order of the injection step S73 and the core back step S74 is changed, and after the core back step S74, the injection step S73 is performed. Since this is a control method for performing the compression mold clamping step S79, there are many portions where the action content overlaps with the above.

For this reason, with regard to overlapping action contents, the detailed description is omitted by referring to the description of the injection molding cycle S78 including the core back step S74.

Since the process up to the mold clamping step S72 is the same as the above-described operation, detailed description thereof is omitted. After the mold clamping step S72, a core back step S74 is performed. Since the operation of the core back step S74 is the same as the operation of the above core back step S74, detailed description thereof is omitted.

Next, the injection step S73 is performed in a state where the mold is opened. The operation of the injection step S73 is the same as the operation of the injection step S73 except that the mold is not in the mold-clamping state and is in a state where the mold is open, and detailed description thereof will be omitted.

Then, the compression mold clamping step S79 is performed at the same time as the injection step S73 or after the injection step S73. However, the compression mold clamping step S79 is necessarily executed while at least the injection step S73 is executed and most of the material injected and filled is in a molten state.

Since the operation procedure of the compression mold clamping step S79 is the same as that of the core back step S74, detailed description thereof is omitted. However, the operation itself of the compression mold clamping step S79 operates each tie bar 14a, 14b, 14c, 14d individually in the direction opposite to that in the core back step S74, that is, the direction in which the mold is clamped. The mold is clamped by moving forward.

Thereafter, the pressure holding and cooling step S75, the mold opening step S76, and the product takeout step S77 are sequentially performed as described above, and one cycle of injection molding is completed by taking out the molded product. By repeating one cycle, an injection molding cycle S78 is obtained.

The correction and setting change by measurement and feedback control related to the core back process S74 and the compression mold clamping process S79 are the same as the correction and setting change by measurement and feedback control related to the core back process S74.

The above is description of the 3rd effect | action by the form of 1st Example especially related to this invention.

Next, the effect of the mold clamping apparatus according to the first embodiment of the present invention will be described.

According to the mold clamping device of the first embodiment of the present invention, at the time of core back or compression mold clamping, each tie bar 14a, 14b, 14c, 14d operates individually according to each target value or command value. Therefore, the mold opening operation or compression mold clamping operation can be controlled in accordance with the expansion speed and injection pressure of the foam material.

Thereby, not only a molded product having a simple shape but also a molded product having a complicated shape can be easily manufactured.

Even if the parallelism does not appear on the front surface of the movable board 16 due to deterioration over time, the parallelism can be corrected by finely adjusting the position of each tie bar at the time of core back or compression mold clamping. The surface on which the mold 42 and the fixed mold 25 form the cavity 43, that is, the surface on which the movable mold 42 and the fixed mold 25 are in contact can be kept parallel.

Further, similarly, in the moving mold 42 or the fixed mold 25, even when the parallelism of the front surface or the back surface of the moving mold 42 and the fixed mold 25 does not appear due to aging, when the core back or the compression mold is clamped, By finely adjusting the position of each tie bar, the surface where the movable mold 42 and the fixed mold 25 are in contact can be kept parallel.

Thereby, a molded product having a uniform thickness can be manufactured regardless of the surface accuracy of the surface to which the mold of the movable platen or the fixed platen is attached and the surface accuracy of the die.

Further, as described above, the present invention can be used in an injection molding machine that performs injection foam molding, an injection molding machine that performs injection compression molding, and an injection molding machine that performs injection press molding.

When the operation amount of each tie bar 14a, 14b, 14c, 14d during the core back exceeds the correction range of the operation amount, the injection molding cycle is automatically stopped upon completion of the injection molding cycle at that time. If it is so controlled, excessive tilting or unevenness or depression exceeding the allowable range on the front surface of the movable platen 16, the front surface of the stationary platen 13, the front surface or the rear surface of the movable mold 42 and the stationary mold 25 due to deterioration over time. Even when the error occurs, since the injection molding cycle can be controlled to automatically stop in the injection molding cycle up to that point, the safety of the injection molding machine can be improved.

At that time, it is displayed as a machine abnormality on a display (not shown) of the control device 20, a sound is given to notify the abnormality by a buzzer (not shown) of the control device 20, and an abnormality is detected by a lamp such as a patrol light (not shown) of the control device 20. If the notification lamp is controlled to be turned on or blinking, it is possible to inform the public that the injection molding machine is abnormal, and it is possible to detect an early failure of the injection molding machine.

As a result, the stop time of the injection molding cycle of the injection molding machine due to the failure of the injection molding machine can be reduced, and the number of molded products produced per unit time can be improved by observation over the medium to long term.

Next, the effect of the mold clamping device control method according to the first embodiment of the present invention will be described.

According to the method for controlling a mold clamping device in the first embodiment of the present invention, each of the tie bars 14a, 14b, 14c, and 14d is individually set according to each target value or command value at the time of core back or compression mold clamping. Therefore, the mold opening operation or compression mold clamping operation can be controlled in accordance with the expansion speed and injection pressure of the foam material.

Thereby, not only a molded product having a simple shape but also a molded product having a complicated shape can be easily manufactured.

Even if the parallelism does not appear on the front surface of the movable board 16 due to deterioration over time, the parallelism can be corrected by finely adjusting the position of each tie bar at the time of core back or compression mold clamping. The surface on which the mold 42 and the fixed mold 25 form the cavity 43, that is, the surface on which the movable mold 42 and the fixed mold 25 are in contact can be kept parallel.

Further, similarly, in the moving mold 42 or the fixed mold 25, even when the parallelism of the front surface or the back surface of the moving mold 42 and the fixed mold 25 does not appear due to aging, when the core back or the compression mold is clamped, By finely adjusting the position of each tie bar, the surface where the movable mold 42 and the fixed mold 25 are in contact can be kept parallel.

Thereby, a molded product having a uniform thickness can be manufactured regardless of the surface accuracy of the surface to which the mold of the movable platen or the fixed platen is attached and the surface accuracy of the die.

Further, as described above, the present invention can be used in an injection molding machine that performs injection foam molding, an injection molding machine that performs injection compression molding, and an injection molding machine that performs injection press molding.

When the operation amount of each tie bar 14a, 14b, 14c, 14d during the core back exceeds the correction range of the operation amount, the injection molding cycle is automatically stopped upon completion of the injection molding cycle at that time. If it is so controlled, excessive tilting or unevenness or depression exceeding the allowable range on the front surface of the movable platen 16, the front surface of the stationary platen 13, the front surface or the rear surface of the movable mold 42 and the stationary mold 25 due to deterioration over time. Even when the error occurs, since the injection molding cycle can be controlled to automatically stop in the injection molding cycle up to that point, the safety of the injection molding machine can be improved.

At that time, it is displayed as a machine abnormality on a display (not shown) of the control device 20, a sound is given to notify the abnormality by a buzzer (not shown) of the control device 20, and an abnormality is detected by a lamp such as a patrol light (not shown) of the control device 20. If the notification lamp is controlled to be turned on or blinking, it is possible to inform the public that the injection molding machine is abnormal, and it is possible to detect an early failure of the injection molding machine.

As a result, the stop time of the injection molding cycle of the injection molding machine due to the failure of the injection molding machine can be reduced, and the number of molded products produced per unit time can be improved by observation over the medium to long term.

Next, a description will be given of a second embodiment according to the present invention.

The form of the second embodiment according to the present invention is similar in configuration and operation to the form of the first embodiment according to the present invention. Therefore, for the description of the configuration and operation of the same parts as those of the first embodiment according to the present invention, reference will be made to the first embodiment according to the present invention, and detailed description thereof will be omitted.

First, the configuration of the mold clamping apparatus according to the second embodiment of the present invention will be described. The configuration of the mold clamping device in the second embodiment according to the present invention is the same as the configuration of the mold clamping device in the first embodiment according to the present invention except for the configuration related to the control device 20.

Therefore, here, the configuration related to the control device 20 which is different from the configuration of the mold clamping device in the form of the first embodiment according to the present invention will be described, and the rest will be described in the form of the first embodiment according to the present invention. The configuration of the mold clamping device will be referred to and detailed description thereof will be omitted.

The control device 20 is connected to the tie bar driving servomotors 15 a, 15 b, 15 c, and 15 d and the mold opening / closing servomotor 17 via the wiring 53.

The control device 20 transmits control signals to the tie bar driving servomotors 15 a, 15 b, 15 c, 15 d and the mold opening / closing servomotor 17 via the wiring 53.

Accordingly, the tie bar driving servomotors 15a, 15b, 15c, 15d and the mold opening / closing servomotor 17 are controlled by the control device 20.

The control device 20 gives separate command values or target values to the four tie bar driving servomotors 15a, 15b, 15c, and 15d during the compression mold clamping operation, so that the tie bar driving servomotors 15a, 15b, 15c, Each of the tie bars 14a, 14b, 14c, and 14d corresponding to the tie bar driving servomotors 15a, 15b, 15c, and 15d is individually operated.

Then, the moving board 16 is advanced through the tie bars 14a, 14b, 14c, and 14d.

Here, the forward movement of the movable platen 16 means moving in a direction approaching the fixed platen 13 in FIG.

The control device 20 also has a setting device for compression mold clamping operation (not shown), a display (not shown), a buzzer (not shown), and a lamp such as a patrol light (not shown).

The setting device for the compression mold clamping operation includes the operation speed of each tie bar during the compression mold clamping operation, the operation force of each tie bar during the compression mold clamping operation, and the correction amount of each tie bar position during the compression mold clamping operation. The operation amount during the compression mold clamping operation is provided as a setting item.

Further, the control device 20 has a main storage device, auxiliary storage device or central processing unit (not shown), and is necessary for performing an injection molding cycle such as a set value set by a setting device for compression mold clamping operation. All setting data (this setting data includes the correction amount for each tie bar movement amount during compression mold clamping operation and data indicating the range of the correction) is stored in a main storage device or auxiliary storage device (not shown). Can be saved.

The stored data can be easily recalled from a main storage device or auxiliary storage device (not shown).

Furthermore, in the main storage device or auxiliary storage device (not shown) of the control device 20, not only setting data but also measurement data measured during the injection molding cycle operation and data taken in as good product data can be stored and stored. it can.

In addition, setting data, measurement data, and non-defective product data stored in a main storage device or auxiliary storage device (not shown) of the control device 20 are converted into numerical data or converted into waveforms by a display (not shown) provided in the control device 20. Can be displayed.

Next, the configuration of the mold clamping device control method according to the second embodiment of the present invention will be described. In addition, about the thing which has the same function as the structure of the control method of the mold clamping apparatus in the form of 1st Example by this invention, it abbreviate | omits detailed description with the same code | symbol.

First, as shown in FIG. 8, as a preparation for entering the injection molding cycle S78, a mold mounting operation S70 and a mold closing adjustment operation S91 are performed.

Then, the mold closing process S92, the injection process S93, the compression mold clamping process S94, the pressure holding and cooling process S75, the mold opening process S76, and the product takeout process S77 are repeated in this order to form an injection molding cycle S78.

However, the mold closing adjustment operation S91 is the starting position of the compression mold clamping operation, and the engagement grooves 24a, 24b, 24c, 24d of the tie bars 14a, 14b, 14c, 14d and the half nuts 18a, 18b, 18c, 18d It is an operation to make the meshing properly.

Here, the compression mold clamping step S94 will be described with reference to FIG. First, as preparation for the compression mold clamping step S94, a compression mold clamping condition S95 is set before the mold mounting operation S70, before the mold closing adjustment operation S91, or after the mold closing adjustment operation S91.

The compression mold clamping condition S95 defines what kind of operation the compression mold clamping operation is to be performed. In this embodiment, the operating speed of each tie bar during the compression mold clamping operation and the compression mold clamping operation time are determined. The operation force of each tie bar, the correction amount of each tie bar position during the compression mold clamping operation, and the operation amount during the compression mold clamping operation can be set.

However, this is one of the compression mold clamping conditions S95, and the operation amount of the compression mold clamping operation representing the start position of the compression mold clamping operation is always set before the mold closing adjustment operation S91.

Then, in the compression mold clamping step S94, from the compression mold clamping operation start S96, the compression mold clamping operation S97 is performed based on the compression mold clamping condition S95, and the operation is terminated by the compression mold clamping operation completion S98. Do it every time.

Next, the operation of the second embodiment according to the present invention will be described. However, in the description of the operation, as in the description of the configuration, the parts different from the operation in the first embodiment according to the present invention will be described, and the first embodiment according to the present invention will be described. A detailed description of the same description as that of the operation is omitted.

First, the parallelism of the mold mounting surface of the movable platen 16, the parallelism of the mold mounting surface of the fixed platen 13, the parallelism of the surface facing the fixed platen 13 of the fixed die 25 and the back surface thereof, The parallelism between the surface of the moving mold 42 facing the moving plate 16 and the surface of the back surface thereof is measured.

Next, the operation amount of the compression mold clamping operation, which is one of the compression mold clamping conditions S95, is input to the setting device for the compression mold clamping operation. This set value is changed in accordance with the shape, material, and injection pressure of the cavity 43.

Next, a mold mounting operation S70 for the fixed mold 25 and the movable mold 42 is performed. Specifically, the mold opening / closing servo motor 17 is driven to move the moving plate 16 to the mold closing limit, and the fixed mold 25 and the movable mold 42 are attached.

Here, the mold closing limit means that the fixed mold 25 and the movable mold 42 are attached to the fixed platen 13 and the movable platen 16, respectively. It is the position that touches.

Next, mold closing adjustment operation S91 is performed. Specifically, after the mold attaching operation S70, the movable board 16 is moved from the position where the mold is closed by the operation amount of the compression mold clamping operation. That is, the moving board 16 is moved to the start position of the compression mold clamping operation.

Thereafter, in the same manner as in the operation of the first embodiment according to the present invention, the engaging grooves 24a, 24b, 24c, 24d of the tie bars 14a, 14b, 14c, 14d and the half nuts 18a, 18b, 18c are obtained. , 18d is properly meshed.

This action is achieved by compressing whether the positions where the engaging grooves 24a, 24b, 24c, 24d of the tie bars 14a, 14b, 14c, 14d are engaged with the half nuts 18a, 18b, 18c, 18d are closed. Since the specific action is the same as that of the first embodiment according to the present invention, only the difference between the start position of the mold clamping operation and detailed description thereof will be omitted.

At this time, the position of each tie bar 14a, 14b, 14c, 14d is read by a position sensor (not shown) in each tie bar driving servo motor 15a, 15b, 15c, 15d, and the position is stored.

Next, the parallelism of the mold mounting surface of the movable platen 16, the parallelism of the mold mounting surface of the fixed platen 13, and the fixed platen 13 of the fixed die 25 are measured in a setting device for compression mold clamping operation. The parallelism between the surface facing and the back surface, the parallelism between the surface facing the moving plate 16 of the moving mold 42 and the back surface, the shape of the cavity 43, the expansion speed of the foam material, the foam material In consideration of the expansion force and injection pressure, the operating speed of each tie bar 14a, 14b, 14c, 14d during the compression mold clamping operation and the operating force of each tie bar 14a, 14b, 14c, 14d during the compression mold clamping operation Then, the correction amount of the position of each tie bar 14a, 14b, 14c, 14d during the compression mold clamping operation is input.

This set value includes the difference in injection pressure, the difference in expansion speed due to the foam material, the difference in expansion force due to the foam material, the parallelism of the mold mounting surface of the movable platen 16 measured in advance, the mold of the fixed platen 13. The parallelism of the mounting surface, the parallelism of the surface facing the stationary platen 13 of the fixed mold 25 and the back surface thereof, and the parallelism of the surface facing the movable platen 16 of the movable mold 42 and the rear surface thereof are different. Therefore, it is changed according to the shape of the cavity 43, the injection pressure, the material, and the parallelism of the above-described surface measured in advance.

Thereafter, the injection molding cycle S78 is started, and the mold closing step S92 is performed first. In the mold closing step S92, the mold opening / closing servo motor 17 and the four tie bar driving servo motors 15a, 15b, 15c, 15d are driven, and the movable board 16 and the four tie bars 14a, 14b, 14c, 14d are closed. The position is moved to the position stored during the adjustment operation S91.

Then, the half nuts 18a, 18b, 18c, 18d are engaged with the engaging grooves 24a, 24b, 24c, 24d of the tie bars 14a, 14b, 14c, 14d, and the moving plate 16 is engaged with the tie bars 14a, 14b, 14c, It fixes to 14d.

At this time, the parallelism of the mold mounting surface of the movable platen 16, the parallelism of the mold mounting surface of the fixed platen 13, the parallelism of the surface facing the fixed platen 13 of the fixed die 25 and the back surface, Due to the difference in parallelism between the surface of the movable mold 42 facing the movable platen 16 and the back surface thereof, the surface that contacts the movable mold 42 and the fixed mold 25, that is, the surface that contacts the fixed mold 25 in the movable mold 42. In some cases, the surface of the fixed mold 25 that contacts the moving mold 42 is not parallel.

Therefore, as a preparatory operation for the compression mold clamping operation, the tie bar driving servomotors 15a, 15b, 15c, and 15d are individually driven, and the tie bars 14a, 14b, 14c, and 14d are respectively tie bars 14a, 14b, and 14c. , 14d is moved by an amount corresponding to the correction amount of the tie bar position at the time of the compression mold clamping operation so that the contact surface of the movable mold 42 and the fixed mold 25 is parallel.

For example, the correction amount of the tie bar position during the compression mold clamping operation with respect to the tie bar 14a is 0.5 [mm], the correction amount of the tie bar position during the compression mold clamping operation with respect to the tie bar 14b is 1.0 [mm], and the compression with respect to the tie bar 14c is performed. The correction amount of the tie bar position during the mold clamping operation is set to 0.1 [mm], and the correction amount of the tie bar position during the compression mold clamping operation with respect to the tie bar 14d is set to -0.5 [mm].

Then, here, the tie bar 14a advances 0.5 [mm], the tie bar 14b advances 1.0 [mm], the tie bar 14c advances 0.1 [mm], and the tie bar 14d moves 0.5 [mm] backward. Thereby, the surface which the movable metal mold | die 42 and the fixed metal mold | die 25 contact becomes parallel.

However, the forward movement of the tie bars 14a, 14b, 14c, and 14d means that the tie bars 14a, 14b, 14c, and 14d move in a direction in which the movable platen 16 is separated from the fixed platen 13 in FIG. , 14b, 14c, 14d means that the tie bars 14a, 14b, 14c, 14d move in a direction in which the movable platen 16 approaches the fixed platen 13 in FIG.

Next, an injection step S93 is performed. In the injection step S93, the material is injected from the injection nozzle while the movable platen 16 is at the set compression mold clamping start position and the movable platen 16 is fixed by the tie bars 14a, 14b, 14c, 14d. . Thereby, the material is filled in the cavity 43. An example of the material is a dissolved resin.

Next, a compression mold clamping step S94 is performed. This compression mold clamping step S94 may be executed after the injection step S93 or at the same time as the injection step S93. However, at least the injection step S93 is executed, and a large amount of material filled by injection is used. This is always done while the part is in the molten state.

In the compression mold clamping step S94, each tie bar driving servomotor 15a, 15b, 15c, 15d is individually driven by the control device 20, and each tie bar corresponding to each tie bar driving servomotor 15a, 15b, 15c, 15d is provided. 14a, 14b, 14c, and 14d are individually operated to move the moving board 16 forward.

Specifically, first, the tie bar driving servo motor 15a is driven, and the tie bar 14a is moved backward via the ball screw 33a. Then, when the engaging groove 24a of the tie bar 14a comes into contact with the half nut 18a as shown in FIG. 6, the movable platen 16 moves according to the tie bar 14a. The same applies to the tie bars 14b, 14c, and 14d.

At this time, each of the tie bars 14a, 14b, 14c, and 14d is individually controlled by the operation speed at the time of the compression mold clamping operation determined by the setting device for the compression mold clamping operation and the operation force at the time of the compression mold clamping operation. Move to the mold closing limit.

For example, the operation speed at the time of the compression mold clamping operation with respect to the tie bar 14a is 1.0 [mm / s], the operation speed at the time of the compression mold clamping operation with respect to the tie bar 14b is 1.5 [mm / s], and the compression mold clamping with respect to the tie bar 14c. The operation speed at the time of operation is set to 2.0 [mm / s], and the operation speed at the time of the compression mold clamping operation with respect to the tie bar 14d is set to 0.5 [mm / s].

The operating force during compression mold clamping operation for the tie bar 14a is 50 [kN], the operating force during compression mold clamping operation for the tie bar 14b is 70 [kN], and the operating force during compression mold clamping operation for the tie bar 14c is 60 [kN]. The operating force during the compression mold clamping operation for the tie bar 14d is set to 40 [kN].

Then, in the compression mold clamping step S94, the tie bar 14a is moved back to the mold closing limit while being controlled to have an operation speed of 1.0 [mm / s] and an operation force of 50 [kN].

The tie bar 14b is retracted to the mold closing limit while being controlled to have an operation speed of 1.5 [mm / s] and an operation force of 70 [kN].

The tie bar 14c is retracted to the mold closing limit while being controlled to have an operation speed of 2.0 [mm / s] and an operation force of 60 [kN].

The tie bar 14d is retracted to the mold closing limit while being controlled to have an operating speed of 0.5 [mm / s] and an operating force of 40 [kN].

As a result, the movable board 16 is advanced to the mold closing limit. Further, the operating speed and operating force of each tie bar 14a, 14b, 14c, 14d at that time are feedback-controlled and controlled while being corrected to be equal to the set value.

The measurement of the operation speed and the operation force of each tie bar 14a, 14b, 14c, 14d at this time is the same as the operation in the first embodiment according to the present invention, and thus detailed description thereof is omitted.

Thereafter, similarly to the operation of the first embodiment according to the present invention, one cycle of injection molding is performed by sequentially performing the pressure holding and cooling step S75, the mold opening step S76, and the product removal step S77, and taking out the molded product. Is completed. Thereafter, this injection molding cycle is repeated by repeating one cycle of this injection molding.

Here, the operation amount of each tie bar 14a, 14b, 14c, 14d during the compression mold clamping operation is measured by a position sensor (not shown) inside each tie bar driving servo motor 15a, 15b, 15c, 15d. The measured value is stored in a main storage device or an auxiliary storage device (not shown) of the control device 20 and stored as measurement data of the operation amount of each tie bar 14a, 14b, 14c, 14d.

For each tie bar 14a, 14b, 14c, 14d, the amount of movement of each tie bar 14a, 14b, 14c, 14d during the set compression mold clamping operation, that is, the amount of operation during the compression mold clamping operation and the compression mold clamping. An error is taken between the amount obtained by adding the correction amount of each tie bar position of each tie bar 14a, 14b, 14c, 14d during operation and the measurement data of the operation amount of each tie bar 14a, 14b, 14c, 14d. At the stage of the preparatory operation of the compression mold clamping operation, correction by feedback control is performed so as to eliminate the error.

However, in the correction by the feedback control, a range that can be corrected by setting data stored in a main storage device or an auxiliary storage device (not shown) included in the control device 20 is determined, and each of the set compression mold clamping operations is set. When the error between the movement amount of the tie bars 14a, 14b, 14c, and 14d and the measurement data of the movement amount of each tie bar 14a, 14b, 14c, and 14d exceeds the correctable range, the control device 20 has a not-shown illustration. It is displayed as a machine abnormality on the display unit, a buzzer (not shown) included in the control device 20 emits a sound notifying the abnormality, and a lamp such as a patrol light (not shown) included in the control device 20 is turned on or blinked automatically. Controls to stop the injection molding cycle upon completion of the injection molding cycle when the abnormality occurs. That.

Further, the correction amount of the tie bar position of each tie bar 14a, 14b, 14c, 14d at the time of the compression mold clamping operation, the operation speed of each tie bar 14a, 14b, 14c, 14d at the compression mold clamping operation, and each at the time of the compression mold clamping operation. The setting of the operating force of the tie bars 14a, 14b, 14c, 14d and the operating amount during the compression mold clamping operation is changed each time depending on the material (including the foaming material), the mold to be attached, and the injection pressure.

The setting change is not only set from the beginning each time, but is also set by saving the data once set as data in a main storage device or auxiliary storage device (not shown) of the control device 20 and calling the stored data. It can also be changed.

In addition, the above setting can be changed by calling the data when the product becomes a non-defective product among the data observed in the compression mold clamping process S94 stored in the main storage device or auxiliary storage device (not shown) which the control device 20 has. You can also.

Next, the effect of the mold clamping device according to the second embodiment of the present invention will be described.

According to the mold clamping apparatus in the form of the second embodiment of the present invention, the tie bars 14a, 14b, 14c, and 14d have their respective target values or values at the time of the compression mold clamping step S94 and the preparation operation for the compression mold clamping operation. Since it operates individually according to the command value, the compression mold clamping operation can be controlled in accordance with the injection pressure and the expansion speed of the foam material.

Thereby, not only a molded product having a simple shape but also a molded product having a complicated shape can be easily manufactured.

Also, the surface where the movable mold 42 and the fixed mold 25 are in contact can be kept parallel for the same reason as in the first embodiment of the present invention. Regardless of the surface accuracy of the surface to which the mold is attached and the surface accuracy of the mold, a molded product having a uniform thickness can be manufactured.

Further, as described above, the present invention can be used in an injection molding machine that performs injection foam molding, an injection molding machine that performs injection compression molding, and an injection molding machine that performs injection press molding.

Even when the operation amount of each tie bar 14a, 14b, 14c, 14d during the compression mold clamping operation exceeds the correction range of the operation amount, for the same reason as in the first embodiment according to the present invention, Since the safety of injection molding machines can be improved and the failure of injection molding machines can be detected early, the stop time of the injection molding machine's injection molding cycle due to the failure of injection molding machines can be reduced. Observation can improve the number of molded products produced per unit time.

Next, effects of the mold clamping device control method according to the second embodiment of the present invention will be described.

According to the mold clamping device control method in the form of the second embodiment of the present invention, the tie bars 14a, 14b, 14c, and 14d are connected to each other during the compression mold clamping step S94 or during the preparation operation for the compression mold clamping operation. Since the operation is performed individually according to the target value or the command value, the compression mold clamping operation can be controlled in accordance with the injection pressure and the expansion speed of the foam material.

Thereby, not only a molded product having a simple shape but also a molded product having a complicated shape can be easily manufactured.

Also, the surface where the movable mold 42 and the fixed mold 25 are in contact can be kept parallel for the same reason as in the first embodiment of the present invention. Regardless of the surface accuracy of the surface to which the mold is attached and the surface accuracy of the mold, a molded product having a uniform thickness can be manufactured.

Further, as described above, the present invention can be used in an injection molding machine that performs injection foam molding, an injection molding machine that performs injection compression molding, and an injection molding machine that performs injection press molding.

Even when the operation amount of each tie bar 14a, 14b, 14c, 14d during the compression mold clamping operation exceeds the correction range of the operation amount, for the same reason as in the first embodiment according to the present invention, Since the safety of injection molding machines can be improved and the failure of injection molding machines can be detected early, the stop time of the injection molding machine's injection molding cycle due to the failure of injection molding machines can be reduced. Observation can improve the number of molded products produced per unit time.

With respect to the two embodiments of the present invention, a pulley and a timing belt are used as power transmission means between the tie bar drive servomotor and the ball screw. It is not necessary to limit, and power may be transmitted by a gear or the like.

The feed screw mechanism such as a screw or a planetary roller screw may be used as long as it is not limited to a ball screw and converts a rotational motion into a linear motion.

  DESCRIPTION OF SYMBOLS 11 ... Clamping device, 13 ... Fixed platen, 14a, 14b, 14c, 14d ... Tie bar, 24a, 24b, 24c, 24d ... Engagement groove, 15a, 15b, 15c, 15d ... Servo motor for tie bar, 16 ... moving board, 17 ... servo motor for mold opening / closing, 18a, 18b, 18c, 18d ... half nut, 20 ... control device

Claims (8)

A fixed plate,
A plurality of tie bars attached to the fixed plate so as to freely advance and retract;
A plurality of drive devices for advancing and retracting the plurality of tie bars;
A movable board that can move forward and backward with respect to the fixed board along the plurality of tie bars;
A fixing mechanism for detachably fixing the movable board to the plurality of tie bars;
A control device,
The control device individually drives the plurality of driving devices by giving separate command values or target values to the plurality of driving devices, and accordingly, the plurality of driving devices corresponding to the plurality of driving devices, respectively. A mold clamping device, wherein each of the tie bars is individually operated to move the moving plate.
2. The mold clamping device according to claim 1, wherein each of the separate command value or target value is a separate operation speed, operation force, or correction amount given to the plurality of driving devices.
The mold clamping apparatus according to claim 1, wherein the plurality of driving devices include a plurality of servo motors that individually operate the plurality of tie bars.
The controller is
The amount of movement when the mold is opened or when the compression mold is clamped,
A correction amount of the tie bar position of each of the plurality of tie bars at the time of mold opening or compression clamping,
The operation speed of each of the plurality of tie bars at the time of mold opening or compression mold clamping,
2. The mold clamping apparatus according to claim 1, further comprising a setting device capable of setting an operating force of each of the plurality of tie bars at the time of mold opening or compression mold clamping.
By giving separate command values or target values to a plurality of driving devices, the plurality of driving devices are individually driven, and accordingly, a plurality of tie bars corresponding to the plurality of driving devices are individually operated. A method of controlling a mold clamping device, wherein the moving platen is controlled to move.
6. The method of controlling a mold clamping device according to claim 5, wherein each of the separate command values or target values described above is a separate operation speed, operation force, or correction amount given to the plurality of drive devices. .
6. The method for controlling a mold clamping device according to claim 5, wherein the driving device includes a plurality of servo motors that individually operate the plurality of tie bars.
To the control unit,
The amount of movement when the mold is opened or when the compression mold is clamped,
A correction amount of the tie bar position of each of the plurality of tie bars at the time of mold opening or compression clamping,
The operation speed of each of the plurality of tie bars at the time of mold opening or compression mold clamping,
6. The method for controlling a mold clamping device according to claim 5, wherein an operating force of each of the plurality of tie bars at the time of mold opening or compression mold clamping can be set.

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