Injection molding machine

Abstract

To provide a technique that prevents malfunction of an injection molding machine.SOLUTION: An injection molding machine comprises: a drive unit; to-be-driven unit driven by the drive unit; a detector provided on the driving unit, and detecting a driving situation of the to-be-driven unit to output a detected signal; and a controller that receives the detected signal to control driving by the drive unit. The detector has a first memory, and the controller has a second memory that stores information common to the first memory. The controller restricts driving by the drive unit when the common information does not match between the first memory and the second memory.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to an injection molding machine.

Background Art

[0002] The injection molding machine described in Patent Document 1 includes a drive unit, a driven unit driven by the drive unit, a detector provided in the drive unit for detecting the driving state of the driven unit and outputting a detection signal, and a control device for controlling the driving by the drive unit according to the detection signal from the detector. The drive unit is, for example, a motor, and the detector is, for example, an encoder for detecting the rotation of the motor.

[0003] The detector has a first memory, and the control device has a second memory. The first memory and the second memory store common information. Thereby, when at least one of the detector and the control device is replaced, comparison or rewriting of the common information becomes possible.

[0004] When the injection molding machine is powered on, the control device performs the above comparison. If the common information does not match, the control device performs control to notify with an alarm and control to display the content of the mismatch on a display.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When the common information does not match between the first memory and the second memory, at least one of the detector and the control device has incorrect information. Driving the drive unit based on the incorrect information may cause malfunction.

[0007] One aspect of the present invention provides a technique for suppressing malfunction of an injection molding machine. [Means for solving the problem]

[0008] An injection molding machine according to one aspect of the present invention is motor And, as stated above motor A driven part driven by the and the motor A detector is provided which detects the driving status of the driven part and outputs a detection signal, and the detection signal is received by motor The detector has a first memory, and the control device has a second memory that stores information common to the first memory. The control device, when the common information is inconsistent between the first memory and the second memory, motor Limiting the drive by The common information includes molding machine information, first information used to drive the motor, and second information used to control the position of the driven part. The control device detects the magnetic pole position of the motor and writes the detected magnetic pole position to the first and second memories if the molding machine information, the first information, and the second information are all inconsistent in the first and second memories. [Effects of the Invention]

[0009] According to one aspect of the present invention, when common information is inconsistent between the first memory and the second memory, the drive unit restricts operation. This suppresses malfunctions based on incorrect information. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows the state of an injection molding machine upon completion of mold opening according to one embodiment. [Figure 2] Figure 2 shows the state of an injection molding machine during mold clamping according to one embodiment. [Figure 3] Figure 3 shows an example of a feedback control system. [Figure 4] Figure 4 shows an example of a combination of a motor, a driven unit, and an encoder. [Figure 5] Figure 5 shows an example of adjusting the magnetic pole position of a motor. [Figure 6] Figure 6 shows an example of the processing of a control device according to one embodiment. [Figure 7] Figure 7 shows an example of information that is typically compared. [Figure 8] Figure 8 shows an example of information that is compared during new manufacturing or when the encoder and control device are replaced simultaneously. [Figure 9] Figure 9 shows an example of the information that is compared when only the encoder is replaced. [Figure 10] Figure 10 shows an example of information that is compared when only the control unit is replaced. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their descriptions may be omitted.

[0012] (injection molding machine) Figure 1 shows the state of an injection molding machine when the mold opening is complete according to one embodiment. Figure 2 shows the state of the injection molding machine when the mold is clamped according to one embodiment. In this specification, the X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other. The X-axis direction and Y-axis direction represent the horizontal direction, and the Z-axis direction represents the vertical direction. When the mold clamping device 100 is horizontal, the X-axis direction is the mold opening and closing direction, and the Y-axis direction is the width direction of the injection molding machine 10. The negative side in the Y-axis direction is called the operating side, and the positive side in the Y-axis direction is called the non-operating side.

[0013] As shown in FIGS. 1 to 2, the injection molding machine 10 includes a mold clamping device 100 for opening and closing the mold device 800, an ejector device 200 for ejecting the molded product formed by the mold device 800, an injection device 300 for injecting a molding material into the mold device 800, a moving device 400 for moving the injection device 300 forward and backward with respect to the mold device 800, a control device 700 for controlling each component of the injection molding machine 10, and a frame 900 for supporting each component of the injection molding machine 10. The frame 900 includes a mold clamping device frame 910 for supporting the mold clamping device 100 and an injection device frame 920 for supporting the injection device 300. The mold clamping device frame 910 and the injection device frame 920 are each installed on the floor 2 via a leveling adjuster 930. The control device 700 is disposed in the internal space of the injection device frame 920. Hereinafter, each component of the injection molding machine 10 will be described.

[0014] (Mold clamping device) In the description of the mold clamping device 100, the moving direction of the movable platen 120 at the time of mold closing (for example, the positive X-axis direction) is defined as the front, and the moving direction of the movable platen 120 at the time of mold opening (for example, the negative X-axis direction) is defined as the rear for the description.

[0015] The mold clamping device 100 performs mold closing, pressure boosting, mold clamping, pressure release, and mold opening of the mold device 800. The mold device 800 includes a fixed mold 810 and a movable mold 820.

[0016] The mold clamping device 100 is, for example, a horizontal type, and the mold opening and closing direction is a horizontal direction. The mold clamping device 100 includes a fixed platen 110 to which the fixed mold 810 is attached, a movable platen 120 to which the movable mold 820 is attached, and a moving mechanism 102 for moving the movable platen 120 in the mold opening and closing direction with respect to the fixed platen 110.

[0017] The fixed platen 110 is fixed to the mold clamping device frame 910. The fixed mold 810 is attached to the opposing surface of the fixed platen 110 with respect to the movable platen 120.

[0018] The movable platen 120 is positioned to move freely in the mold opening and closing direction relative to the mold clamping device frame 910. Guides 101 are laid on the mold clamping device frame 910 to guide the movable platen 120. A movable mold 820 is attached to the surface of the movable platen 120 facing the fixed platen 110.

[0019] The moving mechanism 102 performs mold closing, pressure increasing, mold clamping, depressurization, and mold opening of the mold device 800 by moving the movable platen 120 forward and backward relative to the fixed platen 110. The moving mechanism 102 includes a toggle support 130 positioned at a distance from the fixed platen 110, a tie bar 140 connecting the fixed platen 110 and the toggle support 130, a toggle mechanism 150 that moves the movable platen 120 in the mold opening and closing direction relative to the toggle support 130, a mold clamping motor 160 that operates the toggle mechanism 150, a motion conversion mechanism 170 that converts the rotational motion of the mold clamping motor 160 into linear motion, and a mold thickness adjustment mechanism 180 that adjusts the distance between the fixed platen 110 and the toggle support 130.

[0020] The toggle support 130 is positioned at a distance from the fixed platen 110 and is mounted on the mold clamping device frame 910 so as to be movable in the mold opening and closing direction. The toggle support 130 may also be positioned so as to be movable along a guide laid on the mold clamping device frame 910. The guide for the toggle support 130 may be the same as the guide 101 for the movable platen 120.

[0021] In this embodiment, the fixed platen 110 is fixed to the clamping device frame 910, and the toggle support 130 is arranged to be movable relative to the clamping device frame 910 in the mold opening and closing direction. However, the toggle support 130 may be fixed to the clamping device frame 910, and the fixed platen 110 may be arranged to be movable relative to the clamping device frame 910 in the mold opening and closing direction.

[0022] The tie bars 140 connect the fixed platen 110 and the toggle support 130 at a distance L in the mold opening and closing direction. Multiple tie bars 140 (for example, four) may be used. Multiple tie bars 140 are arranged parallel to the mold opening and closing direction and stretch in accordance with the clamping force. At least one tie bar 140 may be provided with a tie bar strain detector 141 that detects the strain of the tie bar 140. The tie bar strain detector 141 sends a signal indicating its detection result to the control device 700. The detection result of the tie bar strain detector 141 is used for detecting the clamping force, etc.

[0023] In this embodiment, a tie bar strain detector 141 is used as a clamping force detector to detect the clamping force, but the present invention is not limited to this. The clamping force detector is not limited to strain gauge type, but may be piezoelectric, capacitive, hydraulic, electromagnetic, etc., and its mounting position is not limited to the tie bar 140.

[0024] The toggle mechanism 150 is positioned between the movable platen 120 and the toggle support 130, and moves the movable platen 120 in the mold opening and closing direction relative to the toggle support 130. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening and closing direction, and a pair of link groups that bend and extend as the crosshead 151 moves. Each of the link groups has a first link 152 and a second link 153 that are bendable and extendable connected by a pin or the like. The first link 152 is pivotably attached to the movable platen 120 by a pin or the like. The second link 153 is pivotably attached to the toggle support 130 by a pin or the like. The second link 153 is attached to the crosshead 151 via a third link 154. When the crosshead 151 moves forward and backward relative to the toggle support 130, the first link 152 and the second link 153 bend and extend, and the movable platen 120 moves forward and backward relative to the toggle support 130.

[0025] Furthermore, the configuration of the toggle mechanism 150 is not limited to the configuration shown in Figures 1 and 2. For example, in Figures 1 and 2, each link group has five nodes, but it may also have four, and one end of the third link 154 may be connected to the node between the first link 152 and the second link 153.

[0026] The clamping motor 160 is attached to the toggle support 130 and operates the toggle mechanism 150. The clamping motor 160 moves the crosshead 151 forward and backward relative to the toggle support 130, thereby bending and extending the first link 152 and the second link 153, and moving the movable platen 120 forward and backward relative to the toggle support 130. The clamping motor 160 is directly connected to the motion conversion mechanism 170, but it may also be connected to the motion conversion mechanism 170 via a belt, pulley, or the like.

[0027] The motion conversion mechanism 170 converts the rotational motion of the clamping motor 160 into the linear motion of the crosshead 151. The motion conversion mechanism 170 includes a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

[0028] The mold clamping device 100 performs processes such as mold closing, pressure boosting, mold clamping, depressurization, and mold opening under the control of the control device 700.

[0029] In the mold closing process, the clamping motor 160 is driven to advance the crosshead 151 to the mold closing completion position at a set movement speed, thereby advancing the movable platen 120 and bringing the movable mold 820 into contact with the fixed mold 810. The position and movement speed of the crosshead 151 are detected using, for example, a clamping motor encoder 161. The clamping motor encoder 161 detects the rotation of the clamping motor 160 and sends a signal indicating the detection result to the control device 700.

[0030] Furthermore, the crosshead position detector for detecting the position of the crosshead 151 and the crosshead speed detector for detecting the movement speed of the crosshead 151 are not limited to the clamping motor encoder 161, and general-purpose devices can be used. Similarly, the movable platen position detector for detecting the position of the movable platen 120 and the movable platen speed detector for detecting the movement speed of the movable platen 120 are not limited to the clamping motor encoder 161, and general-purpose devices can be used.

[0031] In the boosting process, the clamping motor 160 is further driven to advance the crosshead 151 from the closed position to the clamping position, thereby generating clamping force.

[0032] In the clamping process, the clamping motor 160 is driven to maintain the position of the crosshead 151 in the clamping position. In the clamping process, the clamping force generated in the pressurization process is maintained. In the clamping process, a cavity space 801 (see Figure 2) is formed between the movable mold 820 and the fixed mold 810, and the injection unit 300 fills the cavity space 801 with liquid molding material. A molded product is obtained when the filled molding material solidifies.

[0033] The number of cavity spaces 801 may be one or more. In the latter case, multiple molded products can be obtained simultaneously. An insert material may be placed in part of the cavity space 801, and the molding material may be filled in the other part of the cavity space 801. A molded product in which the insert material and the molding material are integrated is obtained.

[0034] In the depressurization process, the clamping motor 160 is driven to retract the crosshead 151 from the clamping position to the mold opening start position, thereby retracting the movable platen 120 and reducing the clamping force. The mold opening start position and the mold closing completion position may be the same position.

[0035] In the mold opening process, the clamping motor 160 is driven to retract the crosshead 151 from the mold opening start position to the mold opening completion position at a set movement speed, thereby retracting the movable platen 120 and separating the movable mold 820 from the fixed mold 810. Subsequently, the ejector device 200 ejects the molded product from the movable mold 820.

[0036] The setting conditions for the mold closing process, the pressure boosting process, and the mold clamping process are set together as a series of setting conditions. For example, the movement speed and position of the crosshead 151 (including the mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position), and the mold clamping force in the mold closing process and the pressure boosting process are set together as a series of setting conditions. The mold closing start position, movement speed switching position, mold closing completion position, and mold clamping position are arranged in this order from rear to front and represent the start and end points of the section in which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. There may be no movement speed switching positions. The mold clamping position and the mold clamping force may be set individually or individually.

[0037] The setting conditions for the depressurization process and the mold opening process are set similarly. For example, the movement speed and position of the crosshead 151 in the depressurization process and the mold opening process (mold opening start position, movement speed switching position, and mold opening completion position) are set together as a series of setting conditions. The mold opening start position, movement speed switching position, and mold opening completion position are arranged in this order from front to back and represent the start and end points of the sections in which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. There may be no movement speed switching positions. The mold opening start position and the mold closing completion position may be the same position. Also, the mold opening completion position and the mold closing start position may be the same position.

[0038] Furthermore, instead of the movement speed and position of the crosshead 151, the movement speed and position of the movable platen 120 may be set. Also, instead of the position of the crosshead (e.g., the clamping position) or the position of the movable platen, the clamping force may be set.

[0039] Incidentally, the toggle mechanism 150 amplifies the driving force of the clamping motor 160 and transmits it to the movable platen 120. This amplification ratio is also called the toggle ratio. The toggle ratio changes depending on the angle θ between the first link 152 and the second link 153 (hereinafter also referred to as the "link angle θ"). The link angle θ can be determined from the position of the crosshead 151. The toggle ratio is maximized when the link angle θ is 180°.

[0040] If the thickness of the mold device 800 changes due to replacement of the mold device 800 or a change in the temperature of the mold device 800, the mold thickness is adjusted so that a predetermined clamping force is obtained during mold clamping. In mold thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle support 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle at the time of mold touch when the movable mold 820 touches the fixed mold 810.

[0041] The mold clamping device 100 has a mold thickness adjustment mechanism 180. The mold thickness adjustment mechanism 180 adjusts the mold thickness by adjusting the distance L between the fixed platen 110 and the toggle support 130. The timing of the mold thickness adjustment is, for example, between the end of one molding cycle and the start of the next molding cycle. The mold thickness adjustment mechanism 180 includes, for example, a screw shaft 181 formed at the rear end of the tie bar 140, a screw nut 182 that is rotatably and immovably held by the toggle support 130, and a mold thickness adjustment motor 183 that rotates the screw nut 182 that is screwed onto the screw shaft 181.

[0042] A screw shaft 181 and screw nut 182 are provided for each tie bar 140. The rotational driving force of the mold thickness adjustment motor 183 may be transmitted to multiple screw nuts 182 via a rotational driving force transmission unit 185. Multiple screw nuts 182 can be rotated synchronously. It is also possible to rotate multiple screw nuts 182 individually by changing the transmission path of the rotational driving force transmission unit 185.

[0043] The rotational drive force transmission unit 185 is composed of, for example, gears. In this case, driven gears are formed on the outer circumference of each screw nut 182, a drive gear is attached to the output shaft of the mold thickness adjustment motor 183, and an intermediate gear that meshes with the multiple driven gears and the drive gear is rotatably held in the center of the toggle support 130. Note that the rotational drive force transmission unit 185 may be composed of a belt or pulley instead of gears.

[0044] The operation of the mold thickness adjustment mechanism 180 is controlled by the control device 700. The control device 700 drives the mold thickness adjustment motor 183 to rotate the screw nut 182. As a result, the position of the toggle support 130 relative to the tie bar 140 is adjusted, and the distance L between the fixed platen 110 and the toggle support 130 is adjusted. Multiple mold thickness adjustment mechanisms may be used in combination.

[0045] The interval L is detected using the mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the amount and direction of rotation of the mold thickness adjustment motor 183 and sends a signal indicating the detection result to the control device 700. The detection result of the mold thickness adjustment motor encoder 184 is used to monitor and control the position and interval L of the toggle support 130. Note that the toggle support position detector for detecting the position of the toggle support 130 and the interval detector for detecting the interval L are not limited to the mold thickness adjustment motor encoder 184, but general-purpose devices can be used.

[0046] The clamping device 100 may have a mold temperature controller that adjusts the temperature of the mold device 800. The mold device 800 has a flow path for a temperature-controlled medium inside it. The mold temperature controller adjusts the temperature of the mold device 800 by adjusting the temperature of the temperature-controlled medium supplied to the flow path of the mold device 800.

[0047] In this embodiment, the mold clamping device 100 is a horizontal type in which the mold opening and closing direction is horizontal, but it may also be a vertical type in which the mold opening and closing direction is vertical.

[0048] In this embodiment, the clamping device 100 has a clamping motor 160 as a drive unit, but a hydraulic cylinder may be used instead of the clamping motor 160. Furthermore, the clamping device 100 may have a linear motor for opening and closing the mold, and an electromagnet for clamping the mold.

[0049] (Ejector device) In describing the ejector device 200, similar to the description of the clamping device 100, the direction of movement of the movable platen 120 when the mold is closed (for example, the positive X-axis direction) is described as forward, and the direction of movement of the movable platen 120 when the mold is open (for example, the negative X-axis direction) is described as backward.

[0050] The ejector device 200 is attached to the movable platen 120 and moves back and forth together with the movable platen 120. The ejector device 200 includes an ejector rod 210 that ejects the molded product from the mold device 800 and a drive mechanism 220 that moves the ejector rod 210 in the direction of movement of the movable platen 120 (in the X-axis direction).

[0051] The ejector rod 210 is positioned to move back and forth within a through-hole in the movable platen 120. The front end of the ejector rod 210 contacts the ejector plate 826 of the movable mold 820. The front end of the ejector rod 210 may or may not be connected to the ejector plate 826.

[0052] The drive mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts the rotational motion of the ejector motor into the linear motion of the ejector rod 210. The motion conversion mechanism includes a screw shaft and a screw nut that screws onto the screw shaft. A ball or roller may be interposed between the screw shaft and the screw nut.

[0053] The ejector device 200 performs the ejection process under the control of the control device 700. In the ejection process, the ejector rod 210 is advanced from the standby position to the ejection position at a set travel speed, thereby advancing the ejector plate 826 and ejecting the molded product. Subsequently, the ejector motor is driven to retract the ejector rod 210 at a set travel speed, retracting the ejector plate 826 back to its original standby position.

[0054] The position and speed of the ejector rod 210 are detected, for example, using an ejector motor encoder. The ejector motor encoder detects the rotation of the ejector motor and sends a signal indicating the detection result to the control device 700. Note that the ejector rod position detector, which detects the position of the ejector rod 210, and the ejector rod speed detector, which detects the speed of the ejector rod 210, are not limited to ejector motor encoders, but general-purpose devices can be used.

[0055] (injection device) In the description of the injection device 300, unlike the descriptions of the clamping device 100 and the ejector device 200, the direction of movement of the screw 330 during filling (for example, the negative X-axis direction) is described as forward, and the direction of movement of the screw 330 during metering (for example, the positive X-axis direction) is described as backward.

[0056] The injection device 300 is mounted on a slide base 301, which is positioned to move back and forth relative to the injection device frame 920. The injection device 300 is positioned to move back and forth relative to the mold device 800. The injection device 300 touches the mold device 800 and fills the cavity space 801 within the mold device 800 with molding material. The injection device 300 includes, for example, a cylinder 310 for heating the molding material, a nozzle 320 provided at the front end of the cylinder 310, a screw 330 positioned within the cylinder 310 to move back and forth and to rotate, a metering motor 340 for rotating the screw 330, an injection motor 350 for moving the screw 330 back and forth, and a load detector 360 for detecting the load transmitted between the injection motor 350 and the screw 330.

[0057] Cylinder 310 heats the molding material supplied to its interior from the supply port 311. The molding material includes, for example, resin. The molding material is formed, for example, into pellets and supplied to the supply port 311 in a solid state. The supply port 311 is formed at the rear of cylinder 310. A cooler 312, such as a water-cooled cylinder, is provided on the outer circumference of the rear of cylinder 310. In front of the cooler 312, a first heater 313, such as a band heater, and a first temperature detector 314 are provided on the outer circumference of cylinder 310.

[0058] The cylinder 310 is divided into multiple zones along its axial direction (for example, the X-axis direction). A first heater 313 and a first temperature detector 314 are provided in each of the multiple zones. A set temperature is set for each of the multiple zones, and the control device 700 controls the first heater 313 so that the temperature detected by the first temperature detector 314 becomes the set temperature.

[0059] The nozzle 320 is located at the front end of the cylinder 310 and is pressed against the mold device 800. A second heater 323 and a second temperature detector 324 are provided on the outer circumference of the nozzle 320. The control device 700 controls the second heater 323 so that the detected temperature of the nozzle 320 reaches a set temperature.

[0060] The screw 330 is rotatably and reciprocally positioned within the cylinder 310. When the screw 330 is rotated, the molding material is fed forward along the helical groove of the screw 330. As the molding material is fed forward, it is gradually melted by the heat from the cylinder 310. As the liquid molding material is fed forward to the screw 330 and accumulates at the front of the cylinder 310, the screw 330 is retracted. Then, when the screw 330 is advanced, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled into the mold device 800.

[0061] A backflow prevention ring 331 is mounted on the front of the screw 330 so as to be able to move back and forth, acting as a backflow prevention valve to prevent backflow of the molding material from the front to the rear of the screw 330 when the screw 330 is pushed forward.

[0062] When the screw 330 is advanced, the backflow prevention ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and retracts relative to the screw 330 to a closed position (see Figure 2) that blocks the flow path of the molding material. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

[0063] On the other hand, when the screw 330 is rotated, the backflow prevention ring 331 is pushed forward by the pressure of the molding material being sent forward along the helical groove of the screw 330, and moves relative to the screw 330 to an open position (see Figure 1) that opens the flow path of the molding material. As a result, the molding material is sent forward of the screw 330.

[0064] The backflow prevention ring 331 may be either a co-rotating type that rotates together with the screw 330, or a non-co-rotating type that does not rotate together with the screw 330.

[0065] Furthermore, the injection device 300 may have a drive source that moves the backflow prevention ring 331 back and forth between an open position and a closed position relative to the screw 330.

[0066] The metering motor 340 rotates the screw 330. The drive source for rotating the screw 330 is not limited to the metering motor 340; for example, a hydraulic pump or the like may also be used.

[0067] The injection motor 350 moves the screw 330 forward and backward. Between the injection motor 350 and the screw 330, there is a motion conversion mechanism that converts the rotational motion of the injection motor 350 into the linear motion of the screw 330. The motion conversion mechanism has, for example, a screw shaft and a screw nut that screws onto the screw shaft. Balls or rollers may be provided between the screw shaft and the screw nut. The drive source for moving the screw 330 forward and backward is not limited to the injection motor 350, but may also be, for example, a hydraulic cylinder.

[0068] The load detector 360 detects the load transmitted between the injection motor 350 and the screw 330. The detected load is converted into pressure by the control device 700. The load detector 360 is installed in the load transmission path between the injection motor 350 and the screw 330 and detects the load acting on the load detector 360.

[0069] The load detector 360 sends a signal of the detected load to the control device 700. The load detected by the load detector 360 is converted into pressure acting between the screw 330 and the molding material, and is used for controlling and monitoring the pressure the screw 330 receives from the molding material, the back pressure on the screw 330, and the pressure acting from the screw 330 on the molding material.

[0070] Furthermore, the pressure detector used to detect the pressure of the molding material is not limited to the load detector 360, but a general-purpose one can be used. For example, a nozzle pressure sensor or a mold pressure sensor may be used. The nozzle pressure sensor is installed in the nozzle 320. The mold pressure sensor is installed inside the mold device 800.

[0071] The injection device 300 performs processes such as metering, filling, and holding pressure under the control of the control device 700. The filling and holding pressure processes may be collectively referred to as the injection process.

[0072] In the weighing process, the weighing motor 340 is driven to rotate the screw 330 at a set rotational speed, and the molding material is fed forward along the helical groove of the screw 330. As this occurs, the molding material is gradually melted. As the liquid molding material is fed forward by the screw 330 and accumulates at the front of the cylinder 310, the screw 330 is retracted. The rotational speed of the screw 330 is detected, for example, using a weighing motor encoder 341. The weighing motor encoder 341 detects the rotation of the weighing motor 340 and sends a signal indicating the detection result to the control device 700. Note that the screw rotational speed detector for detecting the rotational speed of the screw 330 is not limited to the weighing motor encoder 341, and a general-purpose one can be used.

[0073] In the weighing process, the injection motor 350 may be driven to apply a set back pressure to the screw 330 in order to limit the rapid retraction of the screw 330. The back pressure on the screw 330 is detected, for example, using a load detector 360. The weighing process is completed when the screw 330 has retracted to the weighing completion position and a predetermined amount of molding material has accumulated in front of the screw 330.

[0074] The position and rotational speed of the screw 330 in the metering process are set together as a series of setting conditions. For example, the metering start position, rotational speed switching position, and metering completion position are set. These positions are arranged in this order from front to back and represent the start and end points of the sections in which the rotational speed is set. The rotational speed is set for each section. There may be one or more rotational speed switching positions. The rotational speed switching positions may not be set. In addition, back pressure is set for each section.

[0075] In the filling process, the injection motor 350 is driven to advance the screw 330 at a set speed, filling the cavity space 801 in the mold device 800 with the liquid molding material accumulated in front of the screw 330. The position and speed of the screw 330 are detected, for example, using an injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and sends a signal indicating the detection result to the control device 700. When the position of the screw 330 reaches the set position, a switchover from the filling process to the holding pressure process (so-called V / P switching) occurs. The position at which the V / P switching occurs is also called the V / P switching position. The set speed of the screw 330 may be changed depending on the position and time of the screw 330.

[0076] The position and movement speed of the screw 330 during the filling process are set together as a series of setting conditions. For example, the filling start position (also called the "injection start position"), the movement speed switching position, and the V / P switching position are set. These positions are arranged in this order from rear to front and represent the start and end points of the sections in which the movement speed is set. The movement speed is set for each section. There may be one or more movement speed switching positions. The movement speed switching positions may not be set at all.

[0077] For each section in which the movement speed of the screw 330 is set, an upper limit is set for the pressure of the screw 330. The pressure of the screw 330 is detected by the load sensor 360. If the pressure of the screw 330 is below the set pressure, the screw 330 moves forward at the set movement speed. On the other hand, if the pressure of the screw 330 exceeds the set pressure, for the purpose of protecting the mold, the screw 330 moves forward at a slower movement speed than the set movement speed so that the pressure of the screw 330 becomes below the set pressure.

[0078] Furthermore, during the filling process, after the screw 330 reaches the V / P switching position, the screw 330 may be temporarily stopped at the V / P switching position, and then the V / P switching may be performed. Immediately before the V / P switching, instead of stopping the screw 330, the screw 330 may be moved forward or backward at a slow speed. In addition, the screw position detector that detects the position of the screw 330 and the screw movement speed detector that detects the movement speed of the screw 330 are not limited to the injection motor encoder 351, but general-purpose ones can be used.

[0079] In the holding pressure process, the injection motor 350 is driven to push the screw 330 forward, maintaining the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") at a set pressure, and pushing the molding material remaining in the cylinder 310 toward the mold device 800. This allows for the replenishment of molding material lost due to cooling shrinkage within the mold device 800. The holding pressure is detected, for example, using a load detector 360. The set value of the holding pressure may be changed according to the elapsed time from the start of the holding pressure process. Multiple holding pressures and holding times for maintaining the holding pressure in the holding pressure process may be set, and may be set together as a series of setting conditions.

[0080] During the holding pressure process, the molding material in the cavity space 801 within the mold device 800 is gradually cooled, and upon completion of the holding pressure process, the entrance to the cavity space 801 is sealed with solidified molding material. This state is called a gate seal, and prevents backflow of molding material from the cavity space 801. After the holding pressure process, the cooling process begins. During the cooling process, the molding material in the cavity space 801 is solidified. To shorten the molding cycle time, a metering process may be performed during the cooling process.

[0081] In this embodiment, the injection device 300 is an in-line screw type, but a pre-plasticization type or the like may also be used. In a pre-plasticization injection device, the molding material molten in a plasticizing cylinder is supplied to the injection cylinder, and the molding material is injected from the injection cylinder into the mold device. In the plasticizing cylinder, a screw is arranged to be rotatable but unable to move back and forth, or a screw is arranged to be rotatable and able to move back and forth. On the other hand, a plunger is arranged to be able to move back and forth in the injection cylinder.

[0082] Furthermore, although the injection device 300 in this embodiment is a horizontal type with the axial direction of the cylinder 310 being horizontal, it may also be a vertical type with the axial direction of the cylinder 310 being vertical. The clamping device combined with the vertical injection device 300 may be vertical or horizontal. Similarly, the clamping device combined with the horizontal injection device 300 may be horizontal or vertical.

[0083] (Mobile device) In describing the moving device 400, similar to the description of the injection device 300, the direction of movement of the screw 330 during filling (for example, the negative X-axis direction) is described as forward, and the direction of movement of the screw 330 during metering (for example, the positive X-axis direction) is described as backward.

[0084] The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800. The moving device 400 also presses the nozzle 320 against the mold device 800, generating nozzle touch pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

[0085] The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectional pump, and by switching the rotation direction of the motor 420, it can draw in working fluid (e.g., oil) from either the first port 411 or the second port 412 and discharge it from the other to generate hydraulic pressure. The hydraulic pump 410 can also draw working fluid from a tank and discharge it from either the first port 411 or the second port 412.

[0086] Motor 420 operates the hydraulic pump 410. Motor 420 drives the hydraulic pump 410 with a rotational direction and rotational torque corresponding to the control signal from the control device 700. Motor 420 may be an electric motor or an electric servo motor.

[0087] The hydraulic cylinder 430 comprises a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 divides the inside of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. The piston rod 433 is fixed to the fixed platen 110.

[0088] The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via a first passage 401. The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first passage 401, pushing the injection device 300 forward. As the injection device 300 moves forward, the nozzle 320 is pressed against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates nozzle touch pressure on the nozzle 320 by the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

[0089] Meanwhile, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second passage 402. The working fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second passage 402, pushing the injection device 300 backward. As the injection device 300 is retracted, the nozzle 320 is separated from the fixed mold 810.

[0090] In this embodiment, the moving device 400 includes a hydraulic cylinder 430, but the present invention is not limited thereto. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotational motion of the electric motor into the linear motion of the injection device 300 may be used.

[0091] (Control device) The control device 700 is, for example, a computer and, as shown in Figures 1 and 2, has a CPU (Central Processing Unit) 701, a storage medium 702 such as memory, an input interface 703, and an output interface 704. The control device 700 performs various controls by having the CPU 701 execute a program stored in the storage medium 702. The control device 700 also receives signals from the outside through the input interface 703 and transmits signals to the outside through the output interface 704.

[0092] The control device 700 repeatedly manufactures molded products by repeatedly performing processes such as metering, mold closing, pressure increasing, mold clamping, filling, holding pressure, cooling, depressurization, mold opening, and ejection. A series of operations to obtain a molded product, such as the operations from the start of one metering process to the start of the next metering process, is also called a "shot" or "molding cycle." The time required for one shot is also called the "molding cycle time" or "cycle time."

[0093] A single molding cycle includes, for example, a weighing process, a mold closing process, a pressurizing process, a clamping process, a filling process, a holding pressure process, a cooling process, a depressurizing process, a mold opening process, and an ejection process, in this order. The order here refers to the order in which each process begins. The filling, holding pressure, and cooling processes take place during the clamping process. The start of the clamping process may coincide with the start of the filling process. The completion of the depressurizing process coincides with the start of the mold opening process.

[0094] Furthermore, multiple processes may be performed simultaneously in order to shorten the molding cycle time. For example, the metering process may be performed during the cooling process of the previous molding cycle, or during the mold clamping process. In this case, the mold closing process may be performed at the beginning of the molding cycle. The filling process may also be started during the mold closing process. The ejection process may also be started during the mold opening process. If an on-off valve is provided to open and close the flow path of the nozzle 320, the mold opening process may be started during the metering process. This is because even if the mold opening process is started during the metering process, if the on-off valve closes the flow path of the nozzle 320, the molding material will not leak from the nozzle 320.

[0095] Furthermore, a single molding cycle may include steps other than the weighing step, mold closing step, pressurization step, mold clamping step, filling step, holding pressure step, cooling step, depressurization step, mold opening step, and ejection step.

[0096] For example, after the holding pressure process is completed and before the metering process begins, a pre-metering suck-back process may be performed in which the screw 330 is retracted to a preset metering start position. This reduces the pressure of the molding material accumulated in front of the screw 330 before the metering process begins and prevents the screw 330 from retracting too quickly at the start of the metering process.

[0097] Furthermore, after the metering process is completed and before the filling process begins, a post-metering suck-back process may be performed in which the screw 330 is retracted to a preset filling start position (also called the "injection start position"). This reduces the pressure of the molding material accumulated in front of the screw 330 before the filling process begins and prevents leakage of the molding material from the nozzle 320 before the filling process begins.

[0098] The control device 700 is connected to an operating device 750 that accepts user input operations and a display device 760 that displays a screen. The operating device 750 and the display device 760 may be integrated, for example, by a touch panel 770. The touch panel 770, as the display device 760, displays a screen under the control of the control device 700. The screen of the touch panel 770 may display information such as the settings of the injection molding machine 10 and the current status of the injection molding machine 10. The screen of the touch panel 770 may also display operation parts such as buttons and input fields that accept user input operations. The touch panel 770, as the operating device 750, detects user input operations on the screen and outputs a signal corresponding to the input operation to the control device 700. This allows, for example, the user to operate the operation parts provided on the screen while confirming the information displayed on the screen to set the injection molding machine 10 (including inputting setting values). Furthermore, by operating the operation parts provided on the screen, the user can make the injection molding machine 10 operate in accordance with the operation part. The operation of the injection molding machine 10 may also be the operation (including stopping) of, for example, the clamping device 100, the ejector device 200, the injection device 300, the moving device 400, etc. Furthermore, the operation of the injection molding machine 10 may also be the switching of screens displayed on the touch panel 770, which serves as the display device 760.

[0099] Although the operating device 750 and display device 760 of this embodiment have been described as being integrated as a touch panel 770, they may be provided independently. Furthermore, multiple operating devices 750 may be provided. The operating device 750 and display device 760 are positioned on the operating side (negative Y-axis direction) of the clamping device 100 (more specifically, the fixed platen 110).

[0100] (Details of the control device) Referring to Figure 3, an example of a feedback control system will be described. The injection molding machine 10 includes, for example, a motor 20, a driven unit 30 driven by the motor 20, an encoder 40 that detects the rotation of the motor 20 and outputs a detection signal, and a control device 70 that controls the motor 20 according to the detection signal from the encoder 40. The motor 20 is an example of a drive unit. The encoder 40 is an example of a detector that detects the driving status of the driven unit 30.

[0101] Figure 4 shows examples of combinations of motor 20, driven unit 30, and encoder 40. The first example combination includes a metering motor 340, screw 330, and metering motor encoder 341. The second example combination includes an injection motor 350, screw 330, and injection motor encoder 351. The third example combination includes a clamping motor 160, crosshead 151, and clamping motor encoder 161. Although not shown, a movable platen 120 may be used instead of the crosshead 151. The fourth example combination includes an ejector motor, ejector rod 210, and ejector motor encoder.

[0102] The encoder 40 detects the rotational speed or amount of rotation of the output shaft of the motor 20. The detection signal from the encoder 40 is input to the control device 70 via the interface circuit 80. The control device 70 corresponds to the control device 700 shown in Figures 1 and 2. The control device 70 controls the motor 20 via the inverter 90. The inverter 90 supplies alternating current to the motor 20.

[0103] The encoder 40 has a first memory 41. The first memory 41 is, for example, part of a one-chip microcontroller. The first memory 41 stores, for example, detector information of the encoder 40, magnetic pole position information of the motor 20, and origin position information of the motor 20. The detector information of the encoder 40 is written to the first memory 41 before the encoder 40 is attached to the motor 20. On the other hand, the magnetic pole position information of the motor 20 and the origin position information of the motor 20 are written to the first memory 41 after the encoder 40 is attached to the motor 20, as will be described in more detail later.

[0104] The detector information for the encoder 40 includes, for example, the "model number," "serial number," and "version number." The "model number" allows it to be determined whether the correct model of encoder 40 is installed. Even if the "model number" is the same, the software stored in the control device 70 may be updated to improve the detection method, etc. In such cases, saving the "serial number" or "version number" allows the control device 70 to store the software optimized for the encoder 40.

[0105] The magnetic pole position information of the motor 20 is used to drive the motor 20. The magnetic pole position of the motor 20 is, for example, the magnetic pole position (e.g., N pole position) of the rotor 22 of the motor 20 relative to a reference point (e.g., U phase) of the stator 21 of the motor 20, as shown in Figure 5. The magnetic pole position is the position of the magnet. By knowing the magnetic pole position of the motor 20, it is possible to supply the motor 20 with a current of the appropriate phase, drive the motor 20 properly, and prevent malfunction of the motor 20. Knowing the magnetic pole position of the motor 20 is especially important when the motor 20 is a synchronous motor.

[0106] The origin position information of the motor 20 is used to control the position of the driven part 30. If the driven part 30 is a screw 330, for example, the mechanical forward limit position of the screw 330 is used as the origin position of the motor 20. By detecting the amount of rotation of the motor 20 from its origin position with the encoder 40, the current position of the screw 330 can be determined. Knowing the position of the screw 330 prevents malfunction of the screw 330.

[0107] The first memory 41 may store molding machine information. Molding machine information is information for identifying the injection molding machine 10. Typically, multiple injection molding machines 10 are installed in one factory. In this case, it is desirable to monitor multiple injection molding machines 10 together. Molding machine information is used to identify multiple injection molding machines 10 in order to monitor them together. After the encoder 40 is attached to the motor 20, the molding machine information is stored in the first memory 41 along with magnetic pole position information and origin position information.

[0108] Data writing to the first memory 41 can be performed using well-known techniques, but in this embodiment, it is done using a control device 70 and an operating device 750 (see Figures 1 and 2). The control device 70 writes molding machine information and the like to the first memory 41 according to the input to the operating device 750. The control device 70 not only writes data to the first memory 41 but also reads data from the first memory 41. For this reason, the control device 70 and the first memory 41 are connected by a dedicated line 50. However, the dedicated line 50 is not required, and data writing and data reading may be performed via an interface circuit 80.

[0109] The molding machine information includes, for example, a "machine number" assigned to each injection molding machine 10, and the "installation location" of the encoder 40 in the injection molding machine 10. The "machine number" is a unique number for each injection molding machine 10. Since no two machines have the same machine number, individual identification can be reliably performed. The "machine number" may also include the series name of the injection molding machine 10. The "installation location" is used to distinguish between multiple encoders of the same type used in a single injection molding machine. The "installation location" may be entered using symbols such as "RT", "IJ", "MD", and "EJ". "RT" means that the "installation location" is the metering motor 340, "IJ" means that the "installation location" is the injection motor 350, "MD" means that the "installation location" is the clamping motor 160, and "EJ" means that the "installation location" is the ejector motor.

[0110] The molding machine information may include "plasticizing capacity" and "clamping capacity." Due to unforeseen malfunctions, data corruption may occur in the information stored in the first memory 41 or the second memory 71. By saving "plasticizing capacity" or "clamping capacity," etc., as molding machine information, more data can be compared when comparing data between the first memory 41 and the second memory 71.

[0111] The control device 70 has a second memory 71. The second memory 71 stores information common to the first memory 41. For example, the second memory 71 stores detector information, magnetic pole position information, origin position information, and molding machine information. The molding machine information is stored in the second memory 71 of the control device 70 during the manufacturing stage of the injection molding machine 10. The detector information, magnetic pole position information, and origin position information are stored in the second memory 71 after the encoder 40 is attached to the motor 20.

[0112] As will be described in more detail later, the control device 70 compares common information stored in the first memory 41 and the second memory 71 (for example, detector information, magnetic pole position information, origin position information, and molding machine information) when the injection molding machine 10 is powered on. If the common information does not match, at least one of the encoder 40 and the control device 70 has incorrect information.

[0113] The control device 70 restricts the driving of the motor 20 if there is a mismatch in common information. Restricting the driving of the motor 20 includes, for example, limiting the output of the motor 20 so that at least one of the motor 20's speed (e.g., rotational speed), thrust (e.g., rotational torque), and supply current does not exceed a threshold. The threshold is set so, for example, that a malfunction does not cause damage to a part of the injection molding machine 10 (e.g., the driven part 30).

[0114] As described above, the control device 70 restricts the driving of the motor 20 when the common information is inconsistent. This suppresses malfunctions based on incorrect information and reduces the impact of malfunctions. Preferably, the control device 70 restricts the driving of the motor 20 until the common information matches, and then releases the restriction on the driving of the motor 20 once the common information matches.

[0115] Next, an example of the processing of the control device 70 will be described with reference to Figures 6 to 10. The processing shown in Figure 6 is performed when the injection molding machine 10 is powered on. First, the control device 70 compares the common information stored in the first memory 41 and the second memory 71 and determines whether the common information matches (step S101). The common information to be compared includes, for example, detector information, magnetic pole position information, origin position information, and molding machine information.

[0116] As shown in Figure 7, common information usually matches (step S101, YES). In this case, the control device 70 starts the injection molding machine 10 normally (step S102). When the injection molding machine 10 is started normally, the motor 20 is not restricted, and molded products can be manufactured. When the motor 20 is not restricted, the motor 20 is driven according to a preset value.

[0117] As shown in Figure 8, when the injection molding machine 10 is newly manufactured, or when both the encoder 40 and the control device 70 are replaced at the same time, only the detector information is written to the first memory 41, and only the molding machine information is written to the second memory 71. In this case, the detector information, magnetic pole position information, origin position information, and molding machine information will not all match.

[0118] As shown in Figure 9, when only the encoder 40 is replaced and the control device 70 is not replaced, only the detector information is written to the first memory 41. The second memory 71 contains the molding machine information, as well as the detector information, magnetic pole position information, and origin position information related to the encoder 40 before replacement. In this case, the detector information, magnetic pole position information, origin position information, and molding machine information will not all match.

[0119] As shown in Figure 10, if only the control device 70 is replaced without replacing the encoder 40, the first memory 41 contains detector information, magnetic pole position information, origin position information, and molding machine information. This information does not need to be updated. On the other hand, the second memory 71 contains molding machine information. The detector information, magnetic pole position information, and origin position information do not match between the first memory 41 and the second memory 71, but only the molding machine information matches.

[0120] As is clear from Figures 8 to 10, it is possible to distinguish between new manufacturing or simultaneous replacement, replacement of only the encoder 40, and replacement of only the control device 70 based on whether or not information has been written to the first memory 41 and the second memory 71.

[0121] If the common information is inconsistent (step S101, NO), at least one of the encoder 40 and the control device 70 has incorrect information. In this case, the control device 70 restricts the driving of the motor 20 (step S103). This suppresses malfunctions based on incorrect information and reduces the impact of such malfunctions.

[0122] Next, the control device 70 determines whether or not adjustment of the motor 20 is necessary (step S104). Adjustment of the motor 20 includes, for example, detecting the origin position of the motor 20 and detecting the magnetic pole position of the motor 20. Adjustment of the motor 20 is necessary when a new injection molding machine 10 is manufactured (see Figure 8), when the encoder 40 and the control device 70 are replaced simultaneously (see Figure 8), and when only the encoder 40 is replaced (see Figure 9).

[0123] When only the control device 70 is replaced (see Figure 10), adjustment of the motor 20 is not required. This is because the magnetic pole position information and origin position information written in the first memory 41 do not need to be updated. Furthermore, even if data corruption occurs in information other than the magnetic pole position information and origin position information, adjustment of the motor 20 is not required.

[0124] If adjustment of the motor 20 is not required (step S104, NO), the control device 70 updates the data in at least one of the first memory 41 and the second memory 71 (step S106). For example, when only the control device 70 is replaced (see Figure 10), the control device 70 reads the detector information, magnetic pole position information, and origin position information from the first memory 41 and writes them to the second memory 71. Also, in the event of data corruption, the control device reads the correct data from one of the memories (e.g., the first memory 41) and overwrites the incorrect data stored in the other memory (e.g., the second memory 71) with the correct data.

[0125] On the other hand, if adjustment of the motor 20 is necessary (step S104, YES), the control device 70 notifies the operator via the display device 760 or the like to prompt them to adjust the motor 20. Subsequently, the control device 70 adjusts the motor 20 in accordance with the operator's input operation on the operating device 750 (step S105). The adjustment of the motor 20 includes, as described above, for example, detecting the magnetic pole position of the motor 20 and detecting the origin position of the motor 20.

[0126] As shown in Figure 5, in detecting the magnetic pole position of the motor 20, the control device 70 supplies currents (i.e., DC currents) fixed to a preset phase to the U, V, and W phases. The phases of each phase differ, for example, by 120°. By supplying DC currents, the rotor 22 rotates and stops so that the magnetic pole position of the rotor 22 (e.g., the N pole position) coincides with the reference point of the stator 21 (e.g., the U phase). In this state, the control device 70 detects the magnetic pole position of the motor 20 by detecting the rotation angle of the output shaft of the motor 20 with the encoder 40.

[0127] Although not shown in the diagram, in detecting the origin position of the motor 20, the control device 70 moves the driven part 30 (e.g., screw 330) to a mechanical limit of movement (e.g., forward limit position) using the motor 20. The limit of movement is determined by the stroke of a motion conversion mechanism, such as a ball screw. The motion conversion mechanism converts the rotational motion of the motor 20 into linear motion of the driven part 30. The limit of movement may also be the position where the screw 330 contacts the nozzle 320. In this state, the control device 70 detects the origin position of the motor 20 by detecting the rotation angle of the output shaft of the motor 20 with the encoder 40.

[0128] The detection of the magnetic pole position of the motor 20 and the detection of the origin position of the motor 20 are performed while the motor 20 is being driven in a restricted state. For example, the current supplied to the motor 20 is limited to below a threshold (for example, 20% or less of the maximum current). This helps to suppress malfunctions.

[0129] The detection of the magnetic pole position of motor 20 is performed before the detection of the motor 20's origin position. This is because knowing the magnetic pole position of motor 20 allows for the supply of a current with the appropriate phase to motor 20, thereby enabling proper motor 20 operation.

[0130] Subsequently, the operator inputs the origin position and magnetic pole position detected in step S105 into the operating device 750. Next, the control device 70 writes the origin position and magnetic pole position detected in step S105 into the first memory 41 and the second memory 71 according to the operator's input, and updates the data in the first memory 41 and the second memory 71 (step S106).

[0131] The operator does not need to input the origin position or magnetic pole position numerically. The control device 70 may, upon detecting the origin position or magnetic pole position, automatically (or in response to the operator's button operation) write the origin position or magnetic pole position to the first memory 41 and the second memory 71.

[0132] In step S106, information other than the magnetic pole position information and the origin position information may be updated. For example, when a new injection molding machine 10 is manufactured (see Figure 8), when the encoder 40 and the control device 70 are replaced simultaneously (see Figure 8), and when only the encoder 40 is replaced (see Figure 9), the control device 70 reads the detector information from the first memory 41 and writes it to the second memory 71, and also reads the molding machine information from the second memory 71 and writes it to the first memory 41.

[0133] After step S106, the control device 70 again compares the common information stored in the first memory 41 and the second memory 71 to determine whether the common information matches (step S107). Since the data update has been performed, the common information usually matches. However, if a communication failure or the like occurs during the data update, the common information will not match.

[0134] If the common information does not match (step S107, NO), the control device 70 repeats the process from step S103 onwards. On the other hand, if the common information matches (step S107, YES), the control device 70 releases the restriction on driving by the motor 20 (step S108) and starts the injection molding machine 10 normally (step S102).

[0135] According to this embodiment, the encoder 40 has a first memory 41, and the control device 70 has a second memory 71. The first memory 41 and the second memory 71 store common information. This makes it possible to compare or rewrite the common information when at least one of the encoder 40 and the control device 70 is replaced.

[0136] Furthermore, according to this embodiment, when the injection molding machine 10 is powered on, a comparison of common information is performed, and if the common information does not match, the motor 20 is restricted from driving. In this state, detection of the magnetic pole position or adjustment of the magnetic pole position is performed. By restricting the motor 20 from driving, malfunctions can be suppressed.

[0137] Furthermore, in this embodiment, if only the control device 70 is replaced without replacing the encoder 40, the first memory 41 contains information such as magnetic pole position information. This information does not need to be updated and is read from the first memory 41 and written to the second memory 71. This eliminates the need for detecting the magnetic pole position, making maintenance easier.

[0138] Although embodiments of the injection molding machine according to the present invention have been described above, the present invention is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope described in the claims. These also naturally fall within the technical scope of the present invention. [Explanation of Symbols]

[0139] 10 injection molding machine 20. Motor (drive unit) 30 Driven part 40 Encoders (detectors) 41 First Memory 70 Control device 71 Second Memory

Claims

1. A motor and, The driven part is driven by the motor, The motor is equipped with a detector that detects the driving status of the driven part and outputs a detection signal, A control device that receives the detection signal and controls the drive by the motor, Equipped with, The detector has a first memory, and the control device has a second memory that stores information common to the first memory. The control device restricts the motor's operation when the common information in the first memory and the second memory is inconsistent. The aforementioned common information includes molding machine information, first information used to drive the motor, and second information used to control the position of the driven part. The control device detects the magnetic pole position of the motor and writes the detected magnetic pole position to the first and second memories when the molding machine information, the first information, and the second information are all inconsistent in the first and second memories of the injection molding machine.

2. The injection molding machine according to claim 1, wherein the first information is magnetic pole position information and the second information is origin position information.

3. The injection molding machine according to claim 1 or 2, wherein limiting the output of the motor includes limiting at least one of the motor's speed, thrust, and supply current.

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