JP4355266B2 - Mold thickness adjusting apparatus and mold thickness adjusting method for toggle type mold clamping apparatus - Google Patents

Description

  The present invention relates to a mold thickness adjusting apparatus and a mold thickness adjusting method for a toggle type mold clamping apparatus that are suitable for use in setting (adjusting) the position of a pressure receiving plate by a geared motor incorporating a reduction gear mechanism.

  In general, a toggle type mold clamping device for clamping a mold provided in an injection molding machine uses a toggle link mechanism to connect between a movable plate that supports a movable die and a crosshead that moves forward and backward by a drive unit supported by a pressure receiving plate. The crosshead has a function of increasing the pressure applied to the crosshead and transmitting it to the movable platen, and a predetermined mold clamping force is generated based on the extension of the tie bar when the toggle link mechanism is almost extended. For this reason, when the mold is replaced, it is necessary to set the position of the pressure receiving plate so that a predetermined clamping force is generated. Usually, the position of the pressure receiving plate is automatically set by the mold thickness adjusting device. The

Conventionally, an injection molding machine with automatic mold thickness adjustment by a geared motor disclosed in JP-A-62-220314 has been known as this type of mold thickness adjusting apparatus. This automatic mold thickness adjustment injection molding machine has a servo motor that drives the moving platen via the toggle mechanism, a geared motor that moves the rear platen along the tie bar, and a cross head position detection that detects the cross head position of the toggle mechanism. Means, a mold touch detecting means for detecting that the mold is in contact, a torque limiting means for limiting the output torque of the servo motor, and a crosshead position detecting means for detecting whether the toggle mechanism is fully extended The servo motor is torque limited and driven until the mold touch detection means detects the mold touch, and an initial state detection means for detecting the initial state, and when the mold touch is detected by the initial state detection means, a geared motor and After driving the servo motor, move the rear platen by a certain amount until the moving platen position is below the set clamping force position. The platen position adjusting means for moving the moving platen forward by a fixed amount, and after the adjustment by the platen position adjusting means, the moving platen is positioned at the position corresponding to the set clamping force, and the servo motor is torque limited by the torque limiting means to Rotate the geared motor forward until the touch detection means detects the mold touch, and after touching the mold, reverse the geared motor by a certain amount, then release the servo motor torque limit and touch the geared motor with the mold And a mold clamping force setting control means for rotating forward.
JP-A-62-220314

  By the way, this type of mold thickness adjusting device only needs to be able to perform position setting (position control) with respect to the pressure receiving plate, and accurate speed control and pressure control are not required. Therefore, from the viewpoint of cost merit, the drive motor for adjusting the mold thickness does not use an expensive servo motor as disclosed in the above publication (background art), and is relatively inexpensive with a built-in reduction gear mechanism. There are many cases where geared motors are used. When a geared motor is used, the rotational output of the geared motor is converted into a straight motion by the motion transmission mechanism, and thereby the position of the pressure receiving plate is set. In the case of the above publication, nuts that are screwed to screws formed on the tie bars are provided on the rear surface of the rear platen, and a sprocket is fixed to the nuts, and the other end of the nut is engaged with the flange-shaped portion. The collar is fixed to the rear platen so as to match. And the driving force of the geared motor for moving the rear platen fixed to the rear platen is transmitted to the sprocket via the speed reducer, the sprocket, and the chain.

  On the other hand, when configuring a feedback control system using a geared motor, it is necessary to detect the position of the pressure platen, so a position detector is usually provided in the motion transmission mechanism interposed between the geared motor and the pressure platen. The position of the pressure receiving plate is indirectly detected from the displacement amount (position) in the motion transmission mechanism.

  On the other hand, the toggle type mold clamping device is different from the direct pressure type mold clamping device due to its mold clamping principle, even when the mold and tie bar are slightly expanded or contracted due to disturbance factors such as the heating temperature of the mold and the outside temperature. The mold clamping force fluctuates greatly, and a problem that cannot be ignored such as a deterioration in quality at the time of molding a precision molded product occurs. For example, even if the normal mold clamping force (target value) is set to 400 [kN] before the mold is heated, 500 [kN] due to the thermal expansion of the mold after the mold is heated. May increase to a degree. After the mold is heated, heat is transferred from the mold to the tie bar, so that the tie bar is thermally expanded and the mold clamping force is gradually reduced. The thermal expansion of the mold causes an increase in mold clamping force, and the thermal expansion of the tie bar causes a decrease in mold clamping force. Therefore, the toggle type mold clamping device detects the mold thickness or the mold clamping force during the molding operation, and performs mold clamping force correction control using the mold thickness adjusting device so that a constant mold clamping force is always maintained. By doing so, the position of the pressure plate is corrected.

  However, since the displacement amount (correction amount) of the pressure platen based on such mold clamping force correction control is very small, when the geared motor described above is used, the reduction gear mechanism built into the geared motor and further the motion Backlash in the transmission mechanism is a major problem. That is, after adjusting the position of the pressure platen, production is performed again. During this production, a high-pressure mold clamping force in the backward direction is applied to the pressure platen. The mechanism is displaced, and eventually the position of the pressure platen detected by the position detector at this time includes an error due to backlash, and control based on position detection cannot be performed accurately and stably. There was a problem.

  An object of the present invention is to provide a mold thickness adjusting apparatus and a mold thickness adjusting method for a toggle type mold clamping apparatus that solve the problems existing in the background art.

  A mold thickness adjusting device 1 of a toggle type mold clamping device Mc according to the present invention is capable of moving forward and backward by converting a geared motor 2 incorporating a reduction gear mechanism 2g and a rotational output of the geared motor 2 into at least a linear motion. A motion transmission mechanism 4 applied to the pressure receiving plate 3, a position detection unit 5 that indirectly detects the position of the pressure receiving plate 3, and a control unit 6 that performs feedback control of the geared motor 2 based on the detection result of the position detection unit 5. A mold thickness adjusting device including a rotary encoder 7 for detecting the rotational speed of the motor shaft 2s of the motor portion 2m of the geared motor 2, and a deviation between the detected value Xd related to the mold closing position and the normal reference value Xs. A correction amount Ks for correcting the mold clamping force is obtained based on Ke, and a command value Dc for setting the position of the pressure receiving platen 3 is obtained based on the correction amount Ks. A control unit 6 that feedback-controls the geared motor 2 based on a detection value Dd obtained from the detection result of Dc and the rotary encoder 7, and a motor brake 8 that locks the position of the motor shaft 2 s at least after adjusting the mold thickness. . In this case, according to a preferred aspect of the invention, the motion transmission mechanism 4 includes a rotation transmission gear mechanism 11 that transmits the rotation output of the geared motor 2 and a screw mechanism that converts the rotation motion output from the rotation transmission gear mechanism 11 into a straight motion. 12 can be configured. Further, the rotary encoder 7 and the motor brake 8 can be assembled integrally with the housing 13 of the geared motor 2. Further, as the rotary encoder 7, an incremental encoder that detects the absolute position based on the number of encoder pulses generated with respect to the reference position can be used.

  On the other hand, in the mold thickness adjusting method of the toggle type mold clamping device Mc according to the present invention, the rotational output of the geared motor 2 incorporating the reduction gear mechanism 2g is converted into at least a straight motion by the motion transmission mechanism 4 and can be moved forward and backward. When the position of the pressure receiving plate 3 is indirectly detected by the position detecting unit 5 and the geared motor 2 is feedback controlled based on the detection result of the position detecting unit 5 by the position detecting unit 5, A correction amount Ks for correcting the mold clamping force is obtained based on the deviation Ke between the detection value Xd related to the mold closing position and the normal reference value Xs, and the position of the pressure receiving platen 3 is set based on the correction amount Ks. While obtaining the command value Dc, the detection value obtained from the detection result of the rotary encoder 7 that detects the command value Dc and the rotational speed of the motor shaft 2s of the motor portion 2m of the geared motor 2 is obtained. The geared motor 2 is feedback-controlled by the value Dd, characterized in that it further the position of the motor shaft 2s so as to lock the motor brake 8 at least after the mold thickness adjustment.

  According to the mold thickness adjusting apparatus 1 and the mold thickness adjusting method of the toggle type mold clamping apparatus Mc according to the present invention as described above, the following remarkable effects can be obtained.

  (1) Even when the geared motor 2 incorporating the reduction gear mechanism 2g is used as the drive motor for adjusting the mold thickness, it is possible to eliminate the influence of the error due to backlash that occurs during high-pressure mold clamping, so position detection Control and the like based on can be performed accurately and stably.

  (2) A correction amount Ks for correcting the mold clamping force is obtained based on the deviation Ke between the detection value Xd related to the mold closing position and the normal reference value Xs, and the position of the pressure receiving platen 3 is determined based on the correction amount Ks. A command value Dc for setting is obtained, and the geared motor 2 is determined based on the detection value Dd obtained from the command value Dc and the detection result of the rotary encoder 7 that detects the rotation speed of the motor shaft 2s of the motor portion 2m of the geared motor 2. Since the feedback control is performed, it can be applied to mold clamping force correction control in which the displacement amount (correction amount Ks) of the pressure receiving platen 3 is small and is greatly influenced by backlash, and the most desirable and favorable effect can be obtained.

  (3) If the rotary encoder 7 and the motor brake 8 are integrally assembled to the housing 13 of the geared motor 2 according to a preferred aspect, it is possible to contribute to the overall miniaturization and miniaturization like the servomotor with encoder.

  (4) According to a preferred embodiment, if an incremental encoder that detects the absolute position based on the number of encoder pulses generated with respect to the reference position is used for the rotary encoder 7, a deviation of the reference position due to the influence of backlash can be avoided. An accurate reference position can always be maintained.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, the structure of the mold thickness adjusting apparatus 1 according to the present embodiment and the toggle type mold clamping apparatus Mc including the mold thickness adjusting apparatus 1 will be described with reference to FIGS.

  In FIG. 1, an injection molding machine indicated by M includes a toggle type mold clamping device Mc and an injection device Mi. The toggle type mold clamping device Mc includes a stationary platen 21 and a pressure receiving plate 3 that are spaced apart from each other. The stationary platen 21 is fixed on a machine base (not shown), and the pressure receiving plate 3 moves forward and backward on the machine base. Supported as possible. Further, four tie bars 22 are installed between the fixed platen 21 and the pressure receiving platen 3. In this case, the front ends of the tie bars 22 are fixed to the fixed platen 21 and the rear ends of the tie bars 22 are inserted through the pressure receiving plate 3.

  On the other hand, the movable platen 23 is slidably loaded on the tie bars 22. The movable platen 23 supports the movable mold Cm, the fixed platen 21 supports the fixed mold Cc, and the movable mold Cm and the fixed mold Cc constitute a mold C. Further, a toggle link mechanism L is disposed between the pressure receiving plate 3 and the movable plate 23. The toggle link mechanism L includes a pair of first links La and La pivotally supported on the pressure receiving plate 3, a pair of output links Lc and Lc pivotally supported on the movable plate 23, the first links La and La and the output links Lc, A pair of second links Lb and Lb coupled to the support shaft of Lc are provided, and the second links Lb and Lb are pivotally supported on the cross head 24.

  A mold clamping drive unit 25 is disposed between the pressure receiving plate 3 and the cross head 24. The mold clamping drive unit 25 includes a ball screw portion 26 that is rotatably supported by the pressure receiving plate 3, and a ball nut portion 27 that is screwed into the ball screw portion 26 and is provided integrally with the cross head 24. A ball screw mechanism 28 is provided, and a rotation drive mechanism 29 that rotates the ball screw 26 is provided. The rotation drive mechanism 29 includes a mold clamping servo motor 30, a rotary encoder 31 attached to the servo motor 30 for detecting the rotation speed of the servo motor 30, and a drive gear 32 attached to the shaft of the servo motor 30. A driven gear 33 attached to the ball screw portion 26 and a timing belt 34 spanned between the drive gear 32 and the driven gear 33 are provided.

  Accordingly, when the servo motor 30 is operated, the drive gear 32 is rotated, and the rotation of the drive gear 32 is transmitted to the driven gear 33 via the timing belt 34, and the ball screw portion 26 is rotated to thereby rotate the ball nut. Part 27 moves forward and backward. As a result, the cross head 24 integrated with the ball nut portion 27 moves forward and backward, the toggle link mechanism L bends or extends, and the movable platen 23 moves forward and backward in the mold opening direction (retracting direction) or the mold closing direction (forward movement direction). To do.

  On the other hand, the mold thickness adjusting device 1 is attached to the pressure receiving plate 3. The mold thickness adjusting device 1 includes screw mechanisms 12 formed by forming screw portions 36 on the rear end sides of the four tie bars 22 and screwing adjustment nuts 37 to the respective screw portions 36. In this case, the adjustment nuts 37 also serve as stoppers for the pressure receiving plate 3. Accordingly, when the adjustment nuts 37 are rotated, they are displaced relative to the screw portions 36, so that the pressure receiving plate 3 can be moved forward and backward.

  On the other hand, the geared motor 2 is attached to the side surface of the pressure receiving plate 3. The geared motor 2 serves as a drive motor for adjusting the mold thickness. As shown in FIG. 5, the geared motor 2 has a housing 13, and a motor portion 2 m using an induction motor is assembled to the inner rear half of the housing 13. The motor unit 2m has a motor shaft 2s that is rotatably supported, and an input gear 41 is provided on the outer peripheral surface of the front end portion of the motor shaft 2s. An output shaft 42 is rotatably provided on the front end surface 13 f of the housing 13, and an output gear 43 is provided on the inner side of the output shaft 42. The reduction gear mechanism 2g is configured by interposing the first intermediate gear 44, the second intermediate gear 45, and the like between the input gear 41 and the output gear 43.

  Further, the rear end portion of the motor shaft 2s protrudes outward from the rear end surface 13r of the housing 13, and a first sub-housing 45 is attached to the rear end surface 13r. The motor brake 8 is disposed inside the first sub housing 45. The motor brake 8 has an electromagnet unit 46 and a first brake disc 47 fixed to the rear end surface 13r, and a second brake disc 48 fixed to the motor shaft 2s. Thus, if the electromagnet unit 46 is excited, the first brake board 47 and the second brake board 48 are pressed to lock the position of the motor shaft 2s, and if the electromagnet unit 46 is de-energized, the first brake board is released. 47 and the second brake board 48 are separated from each other, and the lock of the motor shaft 2s is released.

  Further, the rear end portion of the motor shaft 2 s further protrudes outward from the first sub housing 45, and a second sub housing 49 is attached to the outer end surface of the first sub housing 45. A rotary encoder 7 that detects the rotational speed of the motor shaft 2 s is disposed inside the second sub-housing 49. The rotary encoder 7 is an incremental encoder and detects an absolute position based on the number of encoder pulses generated with respect to a reference position. The rotary encoder 7 serves as a position detection unit 5 that indirectly detects the position of the pressure receiving plate 3. Thus, since the rotary encoder 7 and the motor brake 8 are integrally assembled with the housing 13 of the geared motor 2, it is possible to contribute to the overall miniaturization and miniaturization like the servo motor with encoder.

  On the other hand, as shown in FIGS. 3 and 4, a drive gear 51 is attached to the front end side of the output shaft 42, and small gears 52 are integrally attached to the adjustment nuts 37, respectively. In this case, the adjustment nuts 37 and the small gears 52 are coaxially positioned. Further, a large gear 53 that meshes with each small gear 52... And the drive gear 51 is disposed. The large gear 53 is formed in a ring shape, and a rail portion provided along the inner peripheral surface is supported by four support rollers 54 attached to the pressure receiving plate 3. That is, the small gears 52 are arranged at the four corners of the square, and the large gears 53 are arranged at positions surrounded by the small gears 52, so that the small gears 52 mesh with the large gears 53 at the same time. To do. As a result, the rotation transmission gear mechanism 11 in which the rotation output of the geared motor 2 is transmitted from the drive gear 51 to each of the small gears 52 is constituted, and the movement transmission mechanism 4 is constituted by the rotation transmission gear mechanism 11 and the screw mechanism 12. Is configured.

  Therefore, when the geared motor 2 is operated, the large gear 53 is rotated by the rotation of the drive gear 51, and the small gears 52 are simultaneously rotated by the rotation of the large gear 53. Since the adjustment nuts 37 that rotate integrally with the small gears 52 advance and retract along the screw portions 36 of the tie bars 22, the pressure receiving platen 3 also moves forward and backward, and its front-rear direction position is adjusted. .

  Reference numeral 61 denotes a molding machine controller that connects the mold clamping servomotor 30, the rotary encoder 31, the geared motor 2, the rotary encoder 7, and the motor brake 8. In this case, as shown in FIG. 2, the geared motor 2 is fed back to the molding machine controller 61 based on the detection value Dd obtained from the detection result of the rotary encoder 7 and the command value Dc for setting the position of the pressure receiving plate 3. The control part 6 to control is included. As will be described later, for example, a command value based on a correction amount Ks for correcting the mold clamping force is used as the command value Dc. In FIG. 2, 62 is a deviation calculating unit that obtains a deviation between the detected value Dd and the command value Dc, and 63 is a motor including a compensation circuit and an output circuit that drive the motor unit 2 m based on the deviation obtained from the deviation calculating unit 62. Indicates a driver.

  Next, a mold thickness adjusting method according to this embodiment using such a mold thickness adjusting apparatus 1 will be described with reference to FIGS. The illustration shows a mold thickness adjustment method used for a mold clamping force correction method during production operation.

  FIG. 6 is a flowchart showing the processing procedure of the mold clamping force correction method during production operation. Assume that the production operation is performed by automatic molding (step S1). During production operation, when a preset closing position detection time or the number of closing position detection shots is reached, the closing position detection mode is automatically executed (steps S2 and S3). The execution interval of the closed position detection mode may be performed every time a shot is performed, or may be performed every fixed shot (or a fixed time), and may be set in consideration of the degree of variation in mold clamping force in an actual machine. it can.

  In this closed position detection mode, the mold clamping servo motor 30 is activated by the start of the mold clamping operation, and the movable platen 23 moves forward from the mold open position (fully opened position) in the mold closing direction. At this time, the movable platen 23 is first subjected to high-speed mold closing that moves forward at high speed. Then, when the movable platen 23 moves forward in the mold closing direction and reaches a preset low speed / low pressure switching point, it shifts to low speed / low pressure mold closing. In this low-speed and low-pressure mold closing, detection processing for abnormalities such as foreign matters is performed by the mold protection section. When the mold protection section is completed, the mold closed position detection process for the mold C is performed in the closed position detection section. The mold closing position is a position where the movable mold Cm and the fixed mold Cc touch. In the closed position detection mode, the movement amount (displacement amount) of the cross head 24 accompanying the closing of the mold C and the variation amount of the load torque accompanying the closing of the mold C are sequentially detected, and the cross head 24 with respect to the constant movement amount. By sequentially obtaining the variation rate of the load torque, the position when the variation rate reaches a preset set rate is detected as the mold closing position. The closed position detection mode is executed a plurality of times set in advance, and the detection value Xd is obtained from the average of the obtained plurality of mold closed positions (steps S3, S4, and S5).

  Then, a deviation Ke (= Xs−Xd) between the obtained detected value Xd and a preset normal reference value Xs is obtained (step S6). Since the allowable range Re for the deviation Ke is preset in the molding machine controller 61, the allowable range Re is compared with the obtained deviation Ke to determine whether or not the deviation Ke exceeds the allowable range Re. To do. Thereby, when the deviation Ke is within the allowable range Re, the mold clamping force is not corrected. Therefore, the production operation is continued as it is (steps S7 and S1).

  On the other hand, when the deviation Ke exceeds the allowable range Re, the detection value Xd is detected again (steps S7, S8, S1). The example shows a case in which the detection value Xd is continuously detected a plurality of times, and when the obtained deviation Ke continuously exceeds the allowable range Re, the mold clamping force is corrected. Therefore, for example, when the detected value Xd... Is detected twice in succession and the obtained deviation Ke... Exceeds the allowable range Re twice, the mold clamping force correction mode is used to correct the mold clamping force. Perform (steps S8, S9). For this reason, when the allowable range Re is exceeded only once, it is determined that it is due to a temporary factor due to disturbance or the like, and correction is not performed.

  FIG. 7 shows a flowchart of a processing procedure for correcting the mold clamping force in this mold clamping force correction mode. This correction process (die thickness adjustment) is performed by an automatic die thickness adjusting function using the die thickness adjusting apparatus 1. The automatic mold thickness adjusting function is a function in which the mold clamping force is automatically set by setting a target value of the mold clamping force at an initial stage, for example, at the time of mold replacement. In the example, since the correction Ke is performed when the deviation Ke exceeds the allowable range Re a plurality of times (twice) continuously, a plurality of deviations Ke are obtained. Therefore, in this example, an average value is obtained by averaging a plurality of deviations Ke (step S11). In the case of a plurality of deviations Ke, the average value may be used, or the latest deviation Ke may be used. Since the deviation Ke is a deviation with respect to the position of the cross head 24, the deviation Ke is converted into a deviation with respect to the position of the movable platen 23 by a known conversion formula. Thereby, since the correction amount Ks for the movable platen 23 is obtained, the pressure receiving platen 6 is displaced by this correction amount Ks, and correction for canceling out the deviation Ke is performed.

  In this case, the correction process is performed at a specific timing set in advance without interrupting the molding cycle. As a specific timing at which the molding cycle is not interrupted, a period other than the mold clamping period, that is, a period in which no pressure is applied to the pressure receiving plate 3 such as a mold opening period, a protruding period, and an intermediate time can be used. Assume that the overhang period is set as a period (specific timing) for performing the correction process. The molding machine controller 61 monitors whether or not the protruding period has started in accordance with the shift to the mold clamping force correction mode (steps S12 and S13). Then, a command value Dc (correction command) based on the correction amount Ks is output at the start timing of the protruding period, and correction processing is executed based on this correction command (step S14).

  In the correction process, the geared motor 2 is operated based on the command value Dc, and the pressure receiving platen 3 is displaced in a direction in which the deviation Ke is eliminated (step S15). At this time, the pressure receiving platen 3 is moved at a lower speed than the normal speed. Further, the position of the pressure receiving plate 3 is indirectly detected using an encoder pulse of a rotary encoder 7 attached to the geared motor 2. As a result, a detection value Dd based on the detection result of the rotary encoder 7 is obtained, so that the deviation between the detection value Dd and the command value Dc is obtained by the deviation calculation unit 62, and this deviation is given to the motor driver 63. As a result, feedback control for the position is performed (step S16). When the pressure receiving platen 3 has moved to the corrected position based on the command value Dc, that is, the target position corresponding to the correction amount Ks (deviation Ke), the geared motor 2 is controlled to stop (steps S17 and S18).

  Further, the motor brake 8 is controlled by the end of the correction process (mold thickness adjustment), and the braking is turned on (step S19). Thereby, the position of the motor shaft 2s is locked by the motor brake 8. Thus, the mold clamping force correction mode is completed, and normal production operation is continued (steps S10 and S1). Therefore, even if high-pressure clamping is performed in normal production operation and displacement due to backlash occurs in the motion transmission mechanism 4 and the reduction gear mechanism 2g, the motor shaft 2s is locked by the motor brake 8, so the rotary The influence on the encoder 7 is avoided. In particular, even if the rotary encoder 7 is an incremental encoder that detects the absolute position based on the number of encoder pulses generated with respect to the reference position, deviation of the reference position due to the influence of backlash can be avoided, and an accurate reference position can always be maintained. it can.

  As described above, in the mold thickness adjusting method according to the present embodiment, the rotational speed of the motor shaft 2s included in the motor portion 2m of the geared motor 2 is detected by the rotary encoder 7, and the detection value Dd obtained from the detection result of the rotary encoder 7 is detected. The geared motor 2 is feedback-controlled based on the command value Dc for setting the position of the pressure receiving plate 3 and the position of the motor shaft 2s is locked by the motor brake 8 at least after the mold thickness adjustment. Even when the geared motor 2 incorporating the reduction gear mechanism 2g is used as the drive motor for the motor, the influence of the error due to the backlash that occurs during high-pressure mold clamping can be eliminated, and control based on position detection can be performed accurately and accurately. It can be performed stably. In particular, since the command value based on the correction amount Ks for correcting the mold clamping force is used as the command value Dc, the displacement amount (correction amount Ks) of the pressure receiving platen 3 is small and the mold clamping force correction is greatly influenced by backlash. By being applied to the control, the most desirable and good effect can be obtained.

  As described above, the best embodiment has been described in detail, but the present invention is not limited to such an embodiment, and the details, methods, configurations, numerical values, and the like are within the scope not departing from the gist of the present invention. It can be changed, added, or deleted arbitrarily. For example, although an incremental encoder is illustrated as the rotary encoder 7 and an electromagnet type is illustrated as the motor brake 8, they are not limited to the examples, and can be replaced with other types having similar functions. The rotation transmission gear mechanism 11 may be a chain type or belt type transmission mechanism.

The top view of a toggle type mold clamping apparatus provided with the mold thickness adjustment apparatus which concerns on the best embodiment of this invention, Functional block diagram of the same thickness adjustment device, Side configuration diagram showing the main part of the same type thickness adjusting device, Rear view showing the main part of the same thickness adjustment device, Sectional drawing which shows the internal structure of the geared motor in the same type thickness adjustment apparatus, The flowchart which shows the process sequence of the mold clamping force correction method using the mold thickness adjustment method which concerns on the best embodiment of this invention, A flowchart showing a processing procedure of a mold clamping force correction mode in the mold clamping force correction method,

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Type | mold thickness adjustment apparatus 2 Geared motor 2g Reduction gear mechanism 2m Motor part 2s Motor shaft 3 Pressure receiving board 4 Motion transmission mechanism 5 Position detection part 6 Control part 7 Rotary encoder 8 Motor brake 11 Rotation transmission gear mechanism 12 ... Screw mechanism 13 Housing Mc Toggle mold clamping device Dd detection value Dc command value

Claims (5)

  A geared motor with a built-in reduction gear mechanism, a motion transmission mechanism that converts the rotational output of this geared motor into at least a linear motion, and applies it to a pressure receiving plate that can move forward and backward, and indirectly detects the position of this pressure receiving plate. In a mold thickness adjusting device of a toggle type mold clamping device, comprising a position detection unit and a control unit that performs feedback control of the geared motor based on a detection result of the position detection unit, rotation of a motor shaft included in the motor unit of the geared motor A rotary encoder for detecting the number, a correction amount for correcting the mold clamping force based on a deviation between a detection value related to the mold closing position and a normal reference value, and a position of the pressure receiving plate based on the correction amount A command value for setting is obtained, and the geared motor is driven by the detection value obtained from the command value and the detection result of the rotary encoder. A control unit for readback control, at least the mold die thickness adjusting device thickness toggle type mold clamping device, characterized in that it comprises a motor brake for locking the position of the motor shaft after the adjustment.   The said movement transmission mechanism is provided with the rotation transmission gear mechanism which transmits the rotational output of the said geared motor, and the screw mechanism which converts the rotational movement output from this rotation transmission gear mechanism into a rectilinear movement. Mold thickness adjustment device for toggle type mold clamping device.   2. The mold thickness adjusting device for a toggle type mold clamping apparatus according to claim 1, wherein the rotary encoder and the motor brake are integrally assembled with a housing of the geared motor.   4. The mold thickness adjusting device for a toggle type mold clamping apparatus according to claim 1, wherein the rotary encoder is an incremental encoder that detects an absolute position based on the number of encoder pulses generated with respect to a reference position.   The rotation output of the geared motor with a built-in reduction gear mechanism is converted into at least linear motion by the motion transmission mechanism and applied to the pressure receiving plate that can move forward and backward, and the position of the pressure receiving plate is indirectly detected by the position detector. In the mold thickness adjusting method of the toggle type mold clamping device in which the geared motor is feedback-controlled by the control unit based on the detection result of the position detection unit, a deviation between a detection value related to the mold closing position and a normal reference value is obtained. A correction amount for correcting the mold clamping force is obtained based on this, and a command value for setting the position of the pressure receiving plate is obtained based on the correction amount, and the motor shaft having the command value and the motor portion of the geared motor is obtained. The geared motor is feedback-controlled by the detection value obtained from the detection result of the rotary encoder that detects the number of rotations of Mold thickness adjusting method for a toggle-type mold clamping device, characterized in that the position of the motor shaft after the mold thickness adjustment is locked by motor braking.

Images