JP2015136910A - Molding machine and driving method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding machine accurately controlling the amount of open of a mold without adding any specific mechanism or equipment: and to provide a driving method for the molding machine.SOLUTION: The molding machine includes: a fixed platen to which a fixed mold can be mounted; a movable platen to which a movable mold can be mounted; a mold clamping mechanism moving the movable platen to perform clamping of the movable mold and the fixed mold; a driving part operating the mold clamping mechanism; and a control part controlling the driving part. The control part calculates operation loss ΔE of the driving part from operation start of the driving part to operation start of the movable mold on the basis of torque T or power consumption of the driving part.

Description

  Embodiments according to the present invention relate to a molding machine and a driving method thereof.

  In injection molding, when a molten resin is filled at a high pressure into a mold that is completely adhered, molecular orientation may occur in the resin. In this case, distortion occurs in the molded product. Therefore, the injection molding machine may once separate the moving mold from the fixed mold after the moving mold is once brought into contact with the fixed mold during the injection molding. Then, after filling the mold with resin, the injection molding machine performs an operation of bringing the moving mold into close contact with the fixed mold. This makes it difficult for molecular orientation to occur in the resin and reduces the stress remaining in the molded product. In particular, in foam molding, such an injection molding technique is employed.

JP-A-9-220747 JP 2006-334793 A

  On the other hand, the toggle mechanism for operating the moving mold includes a link mechanism connecting a plurality of links and a ball screw for operating the link mechanism. Therefore, play of the toggle pin at the link connecting portion or play between the groove of the ball screw and the mountain exists as backlash or lost motion. Such “play” leads to an error in the distance between the molds. Therefore, when performing injection molding, even if the injection molding machine tries to separate the moving mold from the fixed mold by a desired distance, the “play” may not cause the mold to separate as expected. In this case, when the resin pressure or the foaming pressure is applied to the mold during the resin injection, the moving mold is separated from the fixed mold during the resin injection. Thus, if the position of the moving mold is shifted during injection, the assumed resin amount and foam amount cannot be obtained, and the probability that the molded product becomes defective increases.

  Note that the technique of Patent Document 1 does not consider “play” of the toggle mechanism. Further, in the technique of Patent Document 2, since it is necessary to provide a cavity enlargement mechanism, the cost increases.

  Accordingly, the present invention has been made to solve the above problems, and a molding machine and a driving method thereof capable of accurately controlling the opening amount of a mold without adding a special mechanism or instrument. The purpose is to provide.

    The molding machine according to the present embodiment clamps the movable mold and the fixed mold by moving the movable mold and the stationary plate that can mount the fixed mold, the movable board that can mount the movable mold, and the like. A mold clamping mechanism, a drive unit that operates the mold clamping mechanism, and a control unit that controls the drive unit, the control unit operating loss ΔE of the drive unit from the start of operation of the drive unit to the start of operation of the movable mold Is calculated based on the torque T or power consumption of the drive unit.

  The control unit may set the operation amount of the drive unit from the start of the operation of the drive unit to the time when the torque T or power consumption of the drive unit reaches a peak as the operation loss ΔE.

  When an interval Ds is to be opened between the moving mold and the fixed mold, the operating distance or operating angle of the driving unit corresponding to the interval Ds is set to Es, and the moving mold is moved from the start of the operation of the driving unit. If the operation loss of the drive unit until the start of operation is ΔE, the control unit operates the drive unit by (Es + ΔE) from the state where the movable mold and the fixed mold are in contact, and then drives the operation loss ΔE. The part may be returned.

  The molding machine according to the present embodiment may further include a memory for storing the operation loss ΔE.

  The mold clamping mechanism may include a toggle mechanism that connects a plurality of links.

  The mold clamping mechanism may include a ball screw that moves the moving board.

The molding machine according to the present embodiment may further include an encoder that detects the position or angle of the drive unit. The molding machine driving method according to the present embodiment includes a fixed platen to which a fixed die can be attached, a movable platen to which a movable die can be attached, and the movable die and the fixed die that are moved by moving the movable die. A mold clamping mechanism comprising: a mold clamping mechanism that performs mold clamping; a drive unit that operates the mold clamping mechanism; and a control unit that controls the drive unit,
The method
The operation loss ΔE of the drive unit from the start of operation of the drive unit to the start of operation of the moving mold is calculated based on the torque T or power consumption of the drive unit,
When an interval Ds is to be opened between the moving mold and the fixed mold, the operating distance or operating angle of the driving unit corresponding to the interval Ds is set to Es, and the moving mold is moved from the start of the operation of the driving unit. When the operation loss of the drive unit until the start of operation is ΔE, the drive unit is operated by (Es + ΔE) from the state in which the moving mold and the fixed mold are in contact with each other,
Returning the drive unit by an operating loss ΔE.

  If the actual distance between the moving mold and the fixed mold is Dp when the driving unit is operated by a certain distance or angle Ep, the control unit can determine the distance or angle of the driving unit corresponding to the actual distance Dp. Ep0 may be calculated, and the difference (Ep−Ep0) between the distance or angle Ep0 and the distance or angle Ep may be calculated as the operation loss ΔE.

The figure which shows an example of a structure of the injection molding machine 1 by this embodiment. The figure which shows operation | movement of the toggle mechanism 13 in detail. The figure which shows operation | movement of the toggle mechanism 13 in detail. The graph which shows the detection value E of the encoder ENC of the motor 21, and the graph which shows the torque T or the power consumption P of the motor 21. The graph which shows the detected value E of the encoder of the motor 21, and the position D of the moving mold 12 in a mold closing process. The flowchart which shows calculation operation | movement of operation loss (DELTA) E. FIG. 7 is a flowchart showing an injection / molding operation of the injection molding machine 1.

  Embodiments according to the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a configuration of an injection molding machine 1 according to the present embodiment. The injection molding machine 1 includes a frame 2, a fixed plate 3, a moving plate 4, a tie bar 5, a mold clamping drive mechanism 6, an injection device 7, a control unit 8, an extrusion mechanism 9, a human machine Interface 60 (HMI / F).

  The frame 2 is a base of the injection molding machine 1. The fixed platen 3 is fixed on the frame 2. A fixed mold 11 is attached to the fixed platen 3. One end of the tie bar 5 is fixed to the fixed platen 3 and the other end is fixed to the support platen 10. The tie bar 5 extends from the fixed plate 3 to the support plate 10 through the moving plate 4.

  The moving board 4 is placed on a linear guide (not shown) provided on the frame 2. The movable platen 4 is guided by a tie bar 5 or a linear guide, and can move toward or away from the fixed platen 3. A moving mold 12 is attached to the moving plate 4. The moving mold 12 faces the fixed mold 11, approaches the fixed mold 11 together with the moving board 4, and is combined with the fixed mold 11. When the moving mold 12 and the fixed mold 11 are combined and closed, a space corresponding to the product shape is formed between the moving mold 12 and the fixed mold 11.

  The mold clamping drive mechanism 6 includes a toggle mechanism 13 and a toggle mechanism drive unit 14. The toggle mechanism drive unit 14 includes a mold clamping servomotor 21, a ball screw 22, and a transmission mechanism 23 in order to drive the toggle mechanism 13. A cross head 15 is attached to the tip of the ball screw 22. As the ball screw 22 rotates, the crosshead 15 moves toward or away from the moving board 4. The transmission mechanism 23 transmits the rotation of the mold clamping servomotor 21 to the ball screw 22 and moves the crosshead 15. The encoder ENC is provided in the servo motor 21 and detects the position (angle) of the rotor of the servo motor 21. The encoder ENC sends the detected value to the control unit 8.

  When the toggle mechanism driving unit 14 moves the cross head 15, the toggle mechanism 13 is activated. For example, when the cross head 15 moves toward the movable platen 4, the movable platen 4 moves toward the fixed platen 3 and the mold is closed. On the contrary, when the cross head 15 moves in a direction away from the movable platen 4, the movable platen 4 moves in a direction away from the fixed platen 3, and mold opening is performed.

  The extrusion mechanism 9 includes an extrusion servo motor 71, a ball screw 72, and a transmission mechanism 73 in order to remove the molded product from the moving mold 12. The tip of the ball screw 72 penetrates the inner surface of the moving mold 12. As the ball screw 72 rotates, the ball screw 72 pushes out the product adhered to the inner surface of the moving mold 12. The transmission mechanism 73 transmits the rotation of the extrusion servomotor 71 to the ball screw 72, and moves the ball screw 72 in the left-right direction in FIG. The molds 11 and 12 are designed so that the molded product adheres to the moving mold 12.

  The injection molding machine 1 further includes an extension amount sensor 31 that detects the extension amount of the tie bar 5 and a pressure sensor 33 that detects a clamping force between the fixed mold 11 and the movable mold 12. The sensor 31 detects information related to the mold clamping state (mold closing state). The elongation sensor 31 sends the elongation amount of the tie bar 5 to the control unit 8, and the pressure sensor 33 sends the mold clamping force to the control unit 8. Note that the control unit 8 may calculate the mold clamping force using the extension amount of the tie bar 5 from the extension amount sensor 31. In this case, the pressure sensor 33 is not necessary. Further, a sensor for detecting the rotation speed or torque of the mold clamping servomotor 21 may be arranged in place of or together with the elongation amount sensor 31. The control unit 8 may calculate the elongation amount or the mold clamping force from information such as the rotation speed or torque of the mold clamping servomotor 21. The control unit 8 controls the drive of the mold clamping servomotor 21 based on the extension amount of the tie bar 5 or the mold clamping force.

  The injection device 7 includes a heating barrel (band heater) 41, a screw 42, a measuring unit 43, and an injection device drive unit 44. The heating barrel 41 includes a nozzle 41 a that injects a molten material into a mold and is connected to a hopper 45. The screw 42 is provided so as to be movable inside the heating barrel 41.

  The injection molding machine 1 further includes a temperature sensor 48 that detects the temperature of the heating barrel 41. The temperature sensor 48 sends the temperature of the heating barrel 41 to the control unit 8. The control unit 8 controls the power supplied to the heating barrel 41 based on the temperature of the heating barrel 41.

  The weighing unit 43 includes a weighing servo motor 46 and a transmission mechanism 47 that transmits the rotation of the weighing servo motor 46 to the screw 42. When the weighing servo motor 46 is driven and the screw 42 is rotated in the heating barrel 41, the resin of the molding material is introduced into the heating barrel 41 from the hopper 45. The introduced resin is sent to the front end side of the heating barrel 41 while being heated and kneaded. The resin is melted and stored in the tip portion of the heating barrel 41. The molding material is not limited to a resin, and any material can be used as long as it can be used as a molding material such as metal, glass, rubber, and a carbonized compound containing carbon fiber.

  The injection device drive unit 44 includes an injection servo motor 51, a ball screw 52, and a transmission mechanism 53. As the ball screw 52 rotates, the screw 42 moves in the left-right direction in FIG. The transmission mechanism 53 transmits the rotation of the injection servo motor 51 to the ball screw 52. Thereby, when the injection servo motor 51 is rotated, the screw 42 is moved. The molding material is injected from the nozzle 41a by the screw 42 pushing out the molding material stored in the tip portion of the heating barrel 41 from the nozzle 41a.

  The injection device 7 includes a pressure sensor 55 that detects an injection pressure of the molding material. The pressure sensor 55 sends the detected injection pressure value to the control unit 8. The control unit 8 controls the drive of the injection servo motor 51 based on the injection pressure value. That is, the control unit 8 controls the injection pressure of the molding material by controlling the forward speed (injection speed) of the screw 42.

  The HMI / F 60 displays various information regarding the injection molding machine 1. The HMI / F 60 may be, for example, an input / output device including a display unit and a keyboard, or may be a touch panel display. The operator can input settings such as a command related to the operation of the injection molding machine 1 through the HMI / F 60. For example, the user inputs a set value of the maximum injection pressure, a set value of the clamping force, an operation mode, and the like during the injection process of the injection device 7.

  The control unit 8 monitors information received from the elongation sensor 31 during the injection process, and controls the injection device 7 so that the numerical value obtained from the information does not exceed a preset threshold value. Further, the control unit 8 drives the mold clamping drive mechanism 6 so as to correct “play” such as backlash or lost motion of the toggle mechanism 13 and the ball screw 22. The driving of the mold clamping drive mechanism 6 will be described later. Further, the control unit 8 includes a memory 63 for storing parameters necessary for correcting the “play”.

  2 and 3 are diagrams showing the operation of the toggle mechanism 13 in more detail. For convenience, only the upper part of the toggle mechanism 13 will be described. Since the operation of the lower part of the toggle mechanism 13 can be easily understood from the operation of the upper part of the toggle mechanism 13, the description thereof is omitted. The toggle mechanism 13 includes a crosshead 15 and links L1 to L3. The ball screw 22 is connected to the links L1 to L3 via the cross head 15. The crosshead 15 is connected to the support board 10 and the movable board 4 via links L1 to L3. The crosshead 15 is connected to the link L1 via a toggle pin T1. The link L1 is connected to the link L2 via the toggle pin T2. The link L2 is connected to the link L3 via a toggle pin T3. The link L2 is also coupled to the support board 10. The link L3 is connected to the moving board 4 via a toggle pin T4.

  When the motor 21 shown in FIG. 1 rotates the ball screw 22 and moves the cross head 15 in the direction of the arrow A1 shown in FIG. 2, the cross head 15 pushes up the links L1 to L3. As a result, the links L2 and L3 extend substantially linearly between the support board 10 and the moving board 14. As a result, the moving platen 4 moves toward the fixed platen 3, and the moving die 12 is brought close to the fixed die 11.

  On the other hand, when the motor 21 reversely rotates the ball screw 22 and thereby moves the crosshead 15 in the direction of arrow A2 shown in FIG. 3, the crosshead 15 pushes down the links L1 to L3. As a result, the links L2 and L3 are bent between the support board 10 and the movable board 14. As a result, the moving platen 4 moves away from the fixed platen 3 and moves the moving die 12 away from the fixed die 11.

  Here, as shown in FIGS. 2 and 3, the toggle pins T1 to T4 have some play (slack) to operate the links L1 to L3. Therefore, an operation loss (lost motion) occurs when the moving direction of the crosshead 15 (moving mold 12) is switched from the arrow A1 to the arrow A2. Further, play between the ball screw groove and the mountain of the ball screw 22 also causes a loss of operation. Such an operation loss means an error that the moving mold 12 does not operate despite the motor 21 rotating.

  As described above, the operation loss causes a defect in injection molding such as foam molding. Therefore, it is preferable to correct the operation loss (hereinafter also referred to as ΔE).

  Therefore, in this embodiment, when trying to open the movable mold 12 and the fixed mold 11 by a predetermined distance Ds, the motor 21 does not rotate by the angle Es of the motor 21 corresponding to the distance Ds. Without rotation, it rotates by the correction angle (Es + ΔEs). Thereby, the space between the movable mold 12 and the fixed mold 11 can be actually opened by a predetermined distance Ds. Note that the rotation direction of the motor 21 when the movable mold 12 is separated from the fixed mold 11 is defined as a first direction. Thereafter, the control unit 8 rotates the motor 21 in the second direction opposite to the first direction by the operation loss ΔE. In other words, the motor 21 rotates by a correction angle (Es + ΔEs) to move the movable mold 12 away from the fixed mold 11 by the distance Ds, and then reversely rotates by an operation loss ΔE so as not to move the movable mold 12. To do.

  If the motor 21 does not rotate in the second direction after rotating in the first direction, the distance between the movable mold 12 and the fixed mold 11 is set to a predetermined distance Ds before filling with the resin. However, there is a possibility that the operation loss ΔE spreads due to the resin pressure or the foaming pressure during the resin filling. That is, the interval between the moving mold 12 and the fixed mold 11 is wider than Ds during the resin filling. In this case, the assumed resin pressure or foaming pressure cannot be obtained, and the molded product becomes defective.

  On the other hand, in this embodiment, after the motor 21 rotates in the first direction, the motor 21 rotates in the reverse direction by the amount of operation loss ΔE. That is, the motor 21 corrects the operation loss ΔE so that the movable mold 12 is set at a desired position. Thereby, during filling of the resin, the distance between the moving mold 12 and the fixed mold 11 is not widened, and is maintained at the predetermined distance Ds. Therefore, a good molded product can be formed.

Next, calculation of the operation loss ΔE will be described.
(Calculation of motion loss ΔE)
FIG. 4A is a graph showing the detected value E of the encoder ENC of the motor 21. FIG. 4B is a graph showing the torque T or power consumption P of the motor 21. FIG. 6 is a flowchart showing the operation of calculating the operation loss ΔE.

  Usually, in order to move the movable mold 12 to a desired position, the control unit 8 sets the rotational position (for example, angle) of the motor 21 by a position command. The motor 21 receives electric power from the power source and rotates according to the position command. The toggle mechanism 13 receives the operation of the motor 21 and moves the movable mold 12. The control unit 8 monitors the torque T or the power consumption P of the motor 21.

  First, the motor 21 is rotated in the second direction to bring the movable mold 12 and the fixed mold 11 into contact with each other (E = 0, TorP = 0) (t0, S10). At this time, the toggle pins T1 to T4 are in the state shown in FIG.

  Next, after t0, the motor 21 is rotated in the first direction (S20). Since the motor 21 starts operation, the detection value E of the encoder gradually increases as shown in FIG.

  However, the movement of the moving mold 12 is delayed by the operation loss ΔE. Therefore, at the start of the operation of the motor 21, the torque T or the power consumption P of the motor 21 increases gently.

  At t10, the movable mold 12 starts to move and starts to move away from the fixed mold 11 (S30). At this time, the toggle pins T1 to T4 are in the state shown in FIG. When the moving mold 12 starts to operate, the load of the moving mold 12 is applied to the motor 21. Therefore, as shown in FIG. 4B, the torque T or the power consumption P of the motor 21 has a peak value T0 or P0 at the operation start time t10 of the moving mold 12. The detected value of the encoder ENC from the start of operation of the motor 21 (t0) to the start of operation of the movable mold 12 (t10) is the operation loss ΔE of the motor 21.

  Thereafter, the detection value E of the encoder increases. On the other hand, during the movement of the movable mold 12, the torque T or the power consumption P of the motor 21 is maintained substantially constant.

  Thus, according to the present embodiment, the control unit 8 can detect the operation loss ΔE based on the torque T or the power consumption P of the motor 21. The operation loss ΔE is stored in the memory 63 (S40).

(Injection molding using motion loss ΔE)
FIG. 7 is a flowchart showing the injection / molding operation of the injection molding machine 1. The injection molding machine 1 repeats this injection / molding operation cycle with one injection / molding operation as one cycle. Each cycle includes multiple steps for injection of molding material and molding of the product. For example, each cycle includes a mold closing process, a filling (injecting) process, a metering process, a mold opening process, and an extrusion process.

  The mold closing process is a process in which the movable mold 12 is combined with the fixed mold 11 and a space corresponding to the product shape is formed between the movable mold 12 and the fixed mold 11. As described above, in injection molding such as foam molding, the control unit 8 opens the movable mold 12 from the fixed mold 11 by a predetermined distance Ds after bringing the movable mold 12 into contact with the fixed mold 11.

  For example, FIGS. 5A and 5B are graphs showing the detected value E of the encoder of the motor 21 and the position D of the movable mold 12 in the mold closing process. Es indicates the operating distance or operating angle of the motor 21 corresponding to the distance Ds when the movable mold 12 and the fixed mold 11 are opened by a predetermined distance Ds. Further, as described above, ΔE is an operation loss of the motor 21 from the start of operation of the motor 21 to the start of operation of the movable mold 12. In this case, the control unit 8 rotates the motor 21 by the correction value (Es + ΔE) from the state in which the movable mold 12 and the fixed mold 11 are in contact (t3, S11). Thereby, the moving mold 12 moves by a predetermined interval Ds. Thereafter, the control unit 8 returns (reversely rotates) the motor 21 by the operation loss ΔE (t4, S21). Thereby, during filling of the resin, the distance between the moving mold 12 and the fixed mold 11 is not widened, and is maintained at the predetermined distance Ds. That is, the motor 21 corrects the operation loss ΔE so that the movable mold 12 is set at a desired position.

  In the filling (injecting) step, the nozzle 41 a in FIG. 1 is pressed against the through-hole of the fixed mold 11, and the molding material melted by the heating barrel 41 is injected into the space between the moving mold 12 and the fixed mold 11. (S31). At this time, the control unit 8 drives the injection servo motor 51 to rotate the ball screw 52. Thereby, the screw 42 is pushed in the direction of the molds 11 and 12 in the heating barrel 41. The screw 42 injects the molding material stored at the tip of the heating barrel 41 into the space between the moving mold 12 and the fixed mold 11. In the foam molding, the foaming agent is sealed through the heating barrel 41 or the screw 42 with or after the injection of the molding material (S41).

  The metering step is a step of preparing the molding material by feeding the molding material injected in the next cycle to the tip side of the heating barrel 41 (S51). At this time, the control unit 8 drives the measuring servo motor 46 to rotate the screw 42 in the heating barrel 41. The control unit 8 rotates the screw 42 at a predetermined number of revolutions to send a predetermined amount of the melted and kneaded molding material to the front end side of the heating barrel 41. At the same time, the molding material before melting is introduced from the hopper 45 into the heating barrel 41 by the rotation of the screw 42.

  The mold opening process is a process of separating the moving mold 12 from the fixed mold 11 in order to take out the molded product (S61). At this time, the control unit 8 drives the mold clamping servomotor 21 to move the movable mold 12 in a direction away from the fixed mold 11.

  The extruding step is a step of extruding the product from the moving mold 12 at the tip of the ball screw 72 in order to remove the product from the moving mold 12 (S71). At this time, the controller 8 moves the ball screw 72 in the direction of the movable mold 12 by driving the extrusion servomotor 71. The product adhering to the inner surface of the moving mold 12 is pushed out by the tip of the ball screw 72 and removed. Thus, the injection molding machine 1 performs the injection / molding operation.

  According to the present embodiment, the control unit 8 calculates an operation loss ΔE from the start of operation of the motor 21 to the start of operation of the movable mold 12 based on the torque T or the power consumption P of the motor 12. For example, after the operation of the motor 21 starts, the operation amount of the motor 21 until the time point t10 when the torque T or the power consumption P of the motor 21 reaches the peak is defined as an operation loss ΔE. Thereby, the control part 8 can calculate operation loss (DELTA) E automatically. The operator does not need to actually measure the distance between the moving mold 12 and the fixed mold 11 and to input the measured distance to the HMI / F 60.

  Further, according to the present embodiment, when the movable mold 12 and the fixed mold 11 are opened by a predetermined distance Ds, the control unit 8 is in a state in which the movable mold 12 and the fixed mold 11 are in contact with each other. , The motor 21 is rotated by (Es + ΔE), and then the motor 21 is returned by the operation loss ΔE. By rotating the motor 21 by (Es + ΔE), the interval between the movable mold 12 and the fixed mold 11 can be set to a desired interval (set interval) Ds. Further, by returning the motor 21 by the operating loss ΔE, the interval between the moving mold 12 and the fixed mold 11 is not increased during the resin filling, and the desired distance Ds is maintained. As a result, the injection molding machine 1 can accurately control the opening amount of the mold without adding a special mechanism or instrument.

  In the above embodiment, the operation or position of the motor 21 indicates a rotation operation or a rotation position. However, for example, like a linear motor, the operation or position of the motor 21 may be a linear operation or a linear position.

DESCRIPTION OF SYMBOLS 1 ... Injection molding machine, 3 ... Fixed board, 4 ... Moving board, 6 ... Clamping drive mechanism, 7 ... Injection apparatus, 8 ... Control part, 11 ... Fixed mold, 12 ... Moving mold, 21 ... Clamping servo Motor, ENC ... Encoder

Claims (9)

A fixed platen on which a fixed mold can be attached;
A movable board to which a movable mold can be attached;
A mold clamping mechanism for moving the movable mold and clamping the movable mold and the fixed mold;
A drive unit for operating the mold clamping mechanism;
A control unit for controlling the drive unit,
The control unit calculates an operation loss ΔE of the drive unit from the start of operation of the drive unit to the start of operation of the movable mold based on torque T or power consumption of the drive unit. .   2. The control unit according to claim 1, wherein after the operation of the drive unit starts, an operation amount of the drive unit until a torque T or power consumption of the drive unit reaches a peak is set as the operation loss ΔE. 2. The molding machine according to 1.   When opening the movable mold and the fixed mold by a distance Ds, the operating distance or operating angle of the driving unit corresponding to the distance Ds is set to Es, and the operation of the driving unit is started from the start. When the operation loss of the drive unit until the start of operation of the moving mold is ΔE, the drive unit is operated by (Es + ΔE) from the state in which the moving mold and the fixed mold are in contact, and then the operation The molding machine according to claim 1, wherein the driving unit is returned by a loss ΔE.   The molding machine according to any one of claims 1 to 3, further comprising a memory for storing the operation loss ΔE.   The molding machine according to any one of claims 1 to 4, wherein the mold clamping mechanism includes a toggle mechanism in which a plurality of links are connected.   The molding machine according to any one of claims 1 to 5, wherein the mold clamping mechanism includes a ball screw that moves the movable platen.   The molding machine according to any one of claims 1 to 6, further comprising an encoder that detects a position or an angle of the driving unit. A stationary platen to which a fixed mold can be attached; a movable platen to which a movable mold can be attached; a mold clamping mechanism for moving the movable mold to clamp the movable die and the fixed die; A driving method of a molding machine, comprising: a drive unit that operates the mold clamping mechanism; and a control unit that controls the drive unit,
Calculate the operation loss ΔE of the drive unit from the start of operation of the drive unit to the start of operation of the movable mold based on the torque T or power consumption of the drive unit,
When opening the movable mold and the fixed mold by a distance Ds, the operating distance or operating angle of the driving unit corresponding to the distance Ds is set to Es, and the operation of the driving unit is started from the start. When the operation loss of the drive unit until the start of operation of the moving mold is ΔE, the drive unit is operated by (Es + ΔE) from the state in which the moving mold and the fixed mold are in contact with each other,
A driving method comprising returning the driving unit by the operation loss ΔE.   If the actual distance between the movable mold and the fixed mold is Dp when the driving unit is operated by a certain distance or angle Ep, the control unit may correspond to the actual distance Dp. 9. The drive according to claim 8, wherein a distance or angle Ep0 of the drive unit is calculated, and a difference (Ep-Ep0) between the distance or angle Ep0 and the distance or angle Ep is calculated as the operation loss ΔE. Method.

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