Injection molding machine

Abstract

The invention provides an injection molding machine, and provides a technology capable of properly stopping the action of a movable component of a mold device. The injection molding machine includes an operation device for permitting operation of a movable member of a mold device. The operation device is provided with a first switch operated by one hand and a second switch operated by the other hand. The first switch has a first operation unit that detects an on state and an off state in which the force of an operator is stronger or weaker than that of the on state. The second switch has a second operation unit that detects an on state, an off state in which the force of the operator is stronger than that of the on state, and an off state in which the force of the operator is weaker than that of the on state. The operation of the movable member is permitted only when the first operation part and the second operation part are in the open state at the same time.

Description

[0001] This application claims the benefit of priority based on Japanese Patent Application No. 2024-027596, filed on February 27, 2024. The entire contents of this Japanese patent application are incorporated herein by reference. Technical Field

[0002] The invention relates to an injection molding machine. Background Art

[0003] The injection molding machine described in Patent Document 1 includes: a safety door to prevent workers from coming into contact with the mold assembly; an opening and closing mechanism to automatically open and close the safety door; an operating mechanism that receives operator control; and a control mechanism to control the opening and closing mechanism. The operating mechanism includes a left operating button operated by the worker's left hand and a right operating button operated by the worker's right hand. The control mechanism permits the safety door to close only when the worker presses both the left and right operating buttons simultaneously.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-205932

[0005] Injection molding machines sometimes operate the movable member of the mold device with the safety door open. At this time, it is necessary to prevent the worker from contacting the mold device in a manner different from the safety door.

[0006] Therefore, it is considered that, for example, the operation of the movable member of the mold device is permitted only when the worker presses the left and right operating buttons at the same time. During the operation of the movable member of the mold device, the worker's hands are in contact with the operating device and therefore cannot contact the mold device.

[0007] Sometimes, unexpected abnormalities occur during the operation of the mold device's movable components. In such cases, the operator can simply remove their hands from the left and right operating buttons to stop the mold device's movable components. However, they may reflexively press the left and right operating buttons with both hands. Summary of the Invention

[0008] One embodiment of the present invention provides a technique capable of appropriately stopping the movement of a movable member of a mold device.

[0009] An injection molding machine according to one embodiment of the present invention includes an operating device for permitting movement of a movable member of a mold device. The operating device includes a first switch operated by one hand and a second switch operated by the other hand. The first switch includes a first operating portion that detects an open state and a closed state in which the operator's force is stronger or weaker than the open state. The second switch includes a second operating portion that detects an open state, a closed state in which the operator's force is stronger than the open state, and a closed state in which the operator's force is weaker than the open state. Movement of the movable member is permitted only when both the first and second operating portions are in the open state.

[0010] Effects of the Invention

[0011] According to one embodiment of the present invention, the movement of the movable member of the mold device can be appropriately stopped. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram showing a state of the injection molding machine according to one embodiment when mold opening is completed.

[0013] Figure 2 It is a diagram showing a state of the injection molding machine according to one embodiment when the mold is clamped.

[0014] Figure 3 This is a diagram showing an example of a state in which the safety door is open.

[0015] Figure 4 This is a diagram showing an example of a state in which the safety door is closed.

[0016] Figure 5 This is a diagram showing an example of the arrangement of the first switch and the second switch.

[0017] Figure 6 It is a diagram showing a modified example of the arrangement of the first switch and the second switch.

[0018] Figure 7 This is a diagram showing an example of the arrangement of the third switch.

[0019] In the figure: 10-injection molding machine, 750-operating device, 751-first switch, 751a-first operating part, 752-second switch, 752a-second operating part, 800-mold device, 826-ejector plate (movable component). DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or corresponding components may be denoted by the same reference numerals and their descriptions may be omitted.

[0021] (Injection Molding Machine)

[0022] Figure 1 This is a diagram showing a state of the injection molding machine according to one embodiment when mold opening is completed. Figure 2 This figure shows the mold clamping state of an injection molding machine according to one embodiment. In this specification, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other. The X-axis and Y-axis directions represent horizontal directions, while the Z-axis direction represents the vertical direction. When the mold clamping device 100 is horizontal, the X-axis direction represents the mold opening and closing direction, and the Y-axis direction represents the width of the injection molding machine 10. The negative side in the Y-axis direction is referred to as the operating side, and the positive side in the Y-axis direction is referred to as the side opposite the operating side.

[0023] like Figures 1 and 2 As shown, the injection molding machine 10 includes a mold clamping unit 100 for opening and closing the mold assembly 800; an ejection unit 200 for ejecting a molded product formed by the mold assembly 800; an injection unit 300 for injecting molding material into the mold assembly 800; a moving unit 400 for moving the injection unit 300 forward and backward relative to the mold assembly 800; a control unit 700 for controlling the various components of the injection molding machine 10; and a frame 900 for supporting the various components of the injection molding machine 10. The frame 900 includes a mold clamping unit frame 910 for supporting the mold clamping unit 100 and an injection unit frame 920 for supporting the injection unit 300. The mold clamping unit frame 910 and the injection unit frame 920 are each mounted on the base plate 2 via leveling casters 930. The control unit 700 is located within the interior space of the injection unit frame 920. The components of the injection molding machine 10 are described below.

[0024] (Mold clamping device)

[0025] In the description of the mold clamping device 100, the moving direction of the movable platen 120 when the mold is closed (for example, the positive direction of the X axis) is set as the front, and the moving direction of the movable platen 120 when the mold is open (for example, the negative direction of the X axis) is set as the rear.

[0026] The mold clamping device 100 performs mold closing, pressure raising, mold clamping, pressure releasing, and mold opening of the mold device 800. The mold device 800 includes a fixed mold 810 and a movable mold 820.

[0027] The mold clamping device 100 is, for example, a horizontal type, with the mold opening and closing direction being horizontal. The mold clamping device 100 includes a fixed platen 110 to which the fixed mold 810 is mounted, a movable platen 120 to which the movable mold 820 is mounted, and a moving mechanism 102 for moving the movable platen 120 relative to the fixed platen 110 in the mold opening and closing direction.

[0028] The fixed platen 110 is fixed to the mold clamping device frame 910. The fixed mold 810 is attached to the surface of the fixed platen 110 that faces the movable platen 120.

[0029] The movable platen 120 is arranged to be movable in the mold opening and closing direction relative to the mold clamping device frame 910. A guide 101 is provided on the mold clamping device frame 910 to guide the movable platen 120. The movable mold 820 is mounted on the surface of the movable platen 120 that faces the fixed platen 110.

[0030] The moving mechanism 102 moves the movable platen 120 forward and backward relative to the fixed platen 110, thereby closing, raising the pressure, clamping, releasing the pressure, and opening the mold assembly 800. The moving mechanism 102 includes a toggle base 130 spaced apart from the fixed platen 110, a connecting rod 140 connecting the fixed platen 110 and the toggle base 130, a toggle mechanism 150 that moves the movable platen 120 relative to the toggle base 130 in the mold opening and closing direction, 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 gap between the fixed platen 110 and the toggle base 130.

[0031] The toggle base 130 is spaced apart from the fixed platen 110 and mounted on the mold clamping unit frame 910 so as to be movable in the mold opening and closing direction. Furthermore, the toggle base 130 can be arranged so as to be movable along a guide provided on the mold clamping unit frame 910. The guide of the toggle base 130 can be the same as the guide 101 of the movable platen 120.

[0032] In addition, in this embodiment, the fixed pressure plate 110 is fixed relative to the mold clamping device frame 910, and the elbow seat 130 is configured to be freely movable in the mold opening and closing direction relative to the mold clamping device frame 910, but the elbow seat 130 may also be fixed relative to the mold clamping device frame 910, and the fixed pressure plate 110 may be configured to be freely movable in the mold opening and closing direction relative to the mold clamping device frame 910.

[0033] The connecting rod 140 connects the fixed platen 110 and the toggle seat 130 at a distance L in the mold opening and closing direction. A plurality of connecting rods 140 (e.g., four) may be used. The plurality of connecting rods 140 are arranged parallel to the mold opening and closing direction and extend according to the mold clamping force. A connecting rod strain detector 141 for detecting the strain of the connecting rod 140 may be provided on at least one of the connecting rods 140. The connecting rod strain detector 141 sends a signal indicating its detection result to the control device 700. The detection result of the connecting rod strain detector 141 is used for detecting the mold clamping force, etc.

[0034] In this embodiment, the tie-bar strain detector 141 is used as the mold clamping force detector for detecting the mold clamping force. However, the present invention is not limited to this type. The mold clamping force detector is not limited to a strain gauge type; it may also be a piezoelectric, capacitive, hydraulic, or electromagnetic type. Its mounting location is not limited to the tie-bar 140.

[0035] The toggle mechanism 150 is disposed between the movable platen 120 and the toggle base 130 and moves the movable platen 120 relative to the toggle base 130 in the mold opening and closing direction. The toggle mechanism 150 includes a crosshead 151 that moves in the mold opening and closing direction and a pair of link assemblies that flex and extend as the crosshead 151 moves. The pair of link assemblies each includes a first link 152 and a second link 153, each connected by a pin or the like so as to be flexible and extendable. The first link 152 is swingably mounted to the movable platen 120 by a pin or the like. The second link 153 is swingably mounted to the toggle base 130 by a pin or the like. The second link 153 is mounted to the crosshead 151 via a third link 154. When the crosshead 151 is advanced or retracted relative to the toggle base 130, the first link 152 and the second link 153 flex and extend, causing the movable platen 120 to advance or retract relative to the toggle base 130.

[0036] In addition, the structure of the toggle mechanism 150 is not limited to Figure 1 and Figure 2 For example, in Figure 1 and Figure 2 In the embodiment, the number of nodes of each link group is five, but it may be four, or one end of the third link 154 may be connected to a node between the first link 152 and the second link 153 .

[0037] The mold clamping motor 160 is mounted on the toggle base 130 and operates the toggle mechanism 150. The mold clamping motor 160 advances and retracts the crosshead 151 relative to the toggle base 130, thereby flexing and extending the first link 152 and the second link 153, thereby advancing and retracting the movable platen 120 relative to the toggle base 130. The mold clamping motor 160 is directly connected to the motion conversion mechanism 170, but may alternatively be connected via a belt, pulley, or the like.

[0038] The motion conversion mechanism 170 converts the rotational motion of the mold clamping motor 160 into the linear motion of the crosshead 151. The motion conversion mechanism 170 includes a screw shaft and a screw nut threadedly engaged with the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

[0039] The mold clamping device 100 performs a mold closing process, a pressure increasing process, a mold clamping process, a pressure releasing process, a mold opening process, and the like under the control of the control device 700 .

[0040] During the mold closing process, the mold clamping motor 160 is driven to advance the crosshead 151 at a set movement speed to the mold closing end position, advancing the movable platen 120 to bring the movable mold 820 into contact with the fixed mold 810. The position and movement speed of the crosshead 151 are detected, for example, using a mold clamping motor encoder 161. The mold clamping motor encoder 161 detects the rotation of the mold clamping motor 160 and transmits a signal indicating the detection result to the control device 700.

[0041] The crosshead position detector for detecting the position of the crosshead 151 and the crosshead moving speed detector for detecting the moving speed of the crosshead 151 are not limited to the mold clamping motor encoder 161; conventional detectors can be used. Furthermore, the movable platen position detector for detecting the position of the movable platen 120 and the movable platen moving speed detector for detecting the moving speed of the movable platen 120 are not limited to the mold clamping motor encoder 161; conventional detectors can be used.

[0042] In the pressure increasing step, the mold clamping motor 160 is further driven to further advance the crosshead 151 from the mold closing end position to the mold clamping position, thereby generating a mold clamping force.

[0043] In the mold closing process, the mold closing motor 160 is driven to maintain the position of the cross head 151 at the mold closing position. In the mold closing process, the mold closing force generated in the pressure increasing process is maintained. In the mold closing process, a cavity space 801 is formed between the movable mold 820 and the fixed mold 810 (refer to Figure 2 ), the injection device 300 fills the liquid molding material into the cavity space 801. The filled molding material solidifies, thereby obtaining a molded product.

[0044] The number of mold cavities 801 can be one or more. In the latter case, multiple molded products can be obtained simultaneously. An insert can be placed in a portion of the mold cavity 801, while another portion of the mold cavity 801 is filled with molding material. This can produce a molded product in which the insert and molding material are integrated.

[0045] During the depressurization process, the mold clamping motor 160 is driven to retract the crosshead 151 from the mold clamping position to the mold opening start position, thereby retracting the movable platen 120 to reduce the mold clamping force. The mold opening start position and the mold closing end position may be the same position.

[0046] During the mold opening process, the mold clamping motor 160 is driven to retract the crosshead 151 from the mold opening start position to the mold opening end position at a set movement speed, causing the movable platen 120 to retract, separating the movable mold 820 from the fixed mold 810. The ejector device 200 then ejects the molded product from the movable mold 820.

[0047] The setting conditions in the mold closing process, the pressure increasing process and the mold clamping process are uniformly set as a series of setting conditions. For example, the moving speed, position (including the mold closing start position, the moving speed switching position, the mold closing end position and the mold clamping position) and the mold clamping force of the crosshead 151 in the mold closing process and the pressure increasing process are uniformly set as a series of setting conditions. The mold closing start position, the moving speed switching position, the mold closing end position and the mold clamping position are arranged in sequence from the back to the front, and represent the starting point and end point of the interval for setting the moving speed. The moving speed is set for each interval. The moving speed switching position can be one or more. The moving speed switching position can be not set. Only one of the mold clamping position and the mold clamping force can be set.

[0048] The setting conditions in the depressurization process and the mold opening process are also set in the same way. For example, the moving speed and position (mold opening start position, moving speed switching position and mold opening end position) of the crosshead 151 in the depressurization process and the mold opening process are uniformly set as a series of setting conditions. The mold opening start position, the moving speed switching position and the mold opening end position are arranged in sequence from the front to the back, and represent the starting point and end point of the interval for setting the moving speed. The moving speed is set for each interval. There can be one or more moving speed switching positions. The moving speed switching position can be not set. The mold opening start position and the mold closing end position can be the same position. In addition, the mold opening end position and the mold closing start position can be the same position.

[0049] Alternatively, the moving speed and position of the movable platen 120 may be set instead of the moving speed and position of the crosshead 151. Furthermore, the mold clamping force may be set instead of the position of the crosshead (e.g., mold clamping position) or the position of the movable platen.

[0050] The toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120. This amplification factor is also called the toggle magnification. The toggle magnification changes depending on the angle θ (hereinafter referred to as "link angle θ") formed between the first link 152 and the second link 153. Link angle θ is determined by the position of the crosshead 151. The toggle magnification is maximum when link angle θ is 180°.

[0051] If the thickness of the mold assembly 800 changes due to, for example, replacement of the mold assembly 800 or temperature fluctuations, mold thickness adjustment is performed to achieve a predetermined clamping force during mold clamping. During mold thickness adjustment, for example, the gap L between the fixed platen 110 and the toggle base 130 is adjusted so that the link angle θ of the toggle mechanism 150 reaches a predetermined angle when the movable mold 820 contacts the fixed mold 810.

[0052] The mold clamping device 100 includes a mold thickness adjustment mechanism 180. The mold thickness adjustment mechanism 180 adjusts the distance L between the fixed platen 110 and the toggle base 130, thereby adjusting the mold thickness. Mold thickness adjustment is performed, for example, between the end of a 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 connecting rod 140; a screw nut 182 held in a rotatable and non-retractable manner by the toggle base 130; and a mold thickness adjustment motor 183 that rotates the screw nut 182, which is threadedly engaged with the screw shaft 181.

[0053] A screw shaft 181 and a screw nut 182 are provided for each connecting rod 140. The rotational driving force of the mold thickness adjustment motor 183 can be transmitted to the multiple screw nuts 182 via the rotational driving force transmission unit 185. The multiple screw nuts 182 can be rotated synchronously. In addition, by changing the transmission path of the rotational driving force transmission unit 185, the multiple screw nuts 182 can also be rotated independently.

[0054] The rotational driving force transmission unit 185 is composed of, for example, gears. In this case, driven gears are formed on the outer periphery of each lead screw nut 182, a driving gear is attached to the output shaft of the mold thickness adjustment motor 183, and an intermediate gear meshing with the multiple driven gears and the driving gear is rotatably held in the center of the toggle base 130. Alternatively, the rotational driving force transmission unit 185 may be composed of a belt, pulley, or the like, instead of gears.

[0055] 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 lead screw nut 182. As a result, the position of the toggle base 130 relative to the connecting rod 140 is adjusted, and the distance L between the fixed platen 110 and the toggle base 130 is adjusted. Alternatively, multiple mold thickness adjustment mechanisms may be used in combination.

[0056] The gap L is detected using the mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the rotation amount and rotation direction of the mold thickness adjustment motor 183 and transmits a signal indicating the detection result to the control device 700. The detection results of the mold thickness adjustment motor encoder 184 are used to monitor and control the position of the toggle base 130 and the gap L. The toggle base position detector for detecting the position of the toggle base 130 and the gap detector for detecting the gap L are not limited to the mold thickness adjustment motor encoder 184; conventional detectors can be used.

[0057] The mold clamping device 100 may include a mold temperature regulator for regulating the temperature of the mold device 800. The mold device 800 has a flow path for a temperature regulating medium therein. The mold temperature regulator regulates the temperature of the temperature regulating medium supplied to the flow path of the mold device 800, thereby regulating the temperature of the mold device 800.

[0058] Furthermore, the mold clamping device 100 of the present embodiment is a horizontal type in which the mold opening and closing direction is the horizontal direction, but may be a vertical type in which the mold opening and closing direction is the vertical direction.

[0059] The mold clamping device 100 of this embodiment includes the mold clamping motor 160 as a driving source, but may include a hydraulic cylinder instead of the mold clamping motor 160. Furthermore, the mold clamping device 100 may include a linear motor for mold opening and closing or an electromagnet for mold clamping.

[0060] (Ejector device)

[0061] In the description of the ejector device 200, similar to the description of the mold clamping device 100, the moving direction of the movable platen 120 when the mold is closed (for example, the positive direction of the X-axis) is set to the front, and the moving direction of the movable platen 120 when the mold is open (for example, the negative direction of the X-axis) is set to the rear.

[0062] The ejector device 200 is mounted on the movable platen 120 and moves forward and backward along with the movable platen 120. The ejector device 200 includes an ejector rod 210 for ejecting the molded product from the mold assembly 800, and a drive mechanism 220 for moving the ejector rod 210 in the direction of movement of the movable platen 120 (the X-axis direction).

[0063] The ejector rod 210 is arranged to be able to move forward and backward in the through hole of 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.

[0064] The drive mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts the motor's rotational motion into linear motion of the ejector rod 210. The motion conversion mechanism includes a screw shaft and a screw nut threadedly engaged with the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

[0065] The ejector device 200 performs the ejection process under the control of the control device 700. During the ejection process, the ejector rod 210 advances from the standby position to the ejection position at a set speed, advancing the ejector plate 826 to eject the molded product. The ejector motor then drives the ejector rod 210 backward at the set speed, retracting the ejector plate 826 to its original standby position.

[0066] For example, an ejector motor encoder is used to detect the position and movement speed of ejector rod 210. The ejector motor encoder detects the rotation of the ejector motor and transmits a signal indicating the detection result to control device 700. The ejector rod position detector that detects the position of ejector rod 210 and the ejector rod movement speed detector that detects the movement speed of ejector rod 210 are not limited to the ejector motor encoder; conventional detectors can be used.

[0067] (Injection device)

[0068] In the description of the injection device 300, unlike the description of the mold clamping device 100 and the description of the ejection device 200, the movement direction of the screw 330 during filling (for example, the negative direction of the X-axis) is set to the front, and the movement direction of the screw 330 during metering (for example, the positive direction of the X-axis) is set to the rear.

[0069] The injection device 300 is mounted on a sliding base 301, which is configured to be freely movable relative to the injection device frame 920. The injection device 300 is configured to be freely movable relative to the mold device 800. The injection device 300 contacts 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 disposed at the front end of the cylinder 310, a screw 330 that is freely movable and rotatable within the cylinder 310, a metering motor 340 that rotates the screw 330, an injection motor 350 that advances and retracts the screw 330, and a load detector 360 that detects the load transmitted between the injection motor 350 and the screw 330.

[0070] Cylinder 310 heats the molding material supplied into it from supply port 311. The molding material, for example, includes resin. The molding material is formed into pellets, for example, and supplied to supply port 311 in a solid state. 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 periphery of the rear portion of cylinder 310. A first heater 313, such as a belt heater, and a first temperature detector 314 are provided on the outer periphery of cylinder 310, further in front of cooler 312.

[0071] The cylinder 310 is divided into a plurality of zones along the axial direction (e.g., the X-axis direction) of the cylinder 310. A first heater 313 and a first temperature detector 314 are provided in each of the plurality of zones. A set temperature is set for each of the plurality of zones, and the control device 700 controls the first heater 313 so that the temperature detected by the first temperature detector 314 reaches the set temperature.

[0072] The nozzle 320 is provided at the front end of the cylinder 310 and presses the mold device 800. A second heater 323 and a second temperature detector 324 are provided on the outer periphery of the nozzle 320. The control device 700 controls the second heater 323 so that the detected temperature of the nozzle 320 becomes the set temperature.

[0073] Screw 330 is configured to rotate freely and move forward and backward within cylinder 310. When screw 330 is rotated, the molding material is conveyed forward along the spiral groove of screw 330. As the molding material is conveyed forward, it is gradually melted by the heat from cylinder 310. As the liquid molding material is conveyed forward of screw 330 and accumulates in the front portion of cylinder 310, screw 330 is retracted. Then, when screw 330 is advanced, the liquid molding material accumulated in front of screw 330 is injected from nozzle 320 and fills mold device 800.

[0074] The check ring 331 is installed at the front of the screw 330 so as to be able to move forward and backward. The check ring 331 acts as a check valve to prevent the molding material from flowing backward from the front to the rear of the screw 330 when the screw 330 is pushed forward.

[0075] When the screw 330 is advanced, the check ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and moves back relative to the screw 330 to a closed position for closing the flow path of the molding material (refer to FIG. Figure 2 ). This prevents the molding material accumulated in front of the screw 330 from flowing backward.

[0076] On the other hand, when the screw 330 is rotated, the check ring 331 is pushed forward by the pressure of the molding material conveyed forward along the spiral groove of the screw 330, and moves forward relative to the screw 330 to an open position where the flow path of the molding material is opened (refer to FIG. Figure 1 ). As a result, the molding material is transported to the front of the screw 330.

[0077] The check ring 331 may be of 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 .

[0078] In addition, the injection device 300 may include a drive source that moves the check ring 331 forward and backward relative to the screw 330 between the open position and the closed position.

[0079] The metering motor 340 rotates the screw 330. The driving source for rotating the screw 330 is not limited to the metering motor 340, and may be, for example, a hydraulic pump.

[0080] The injection motor 350 advances and retracts the screw 330. A motion conversion mechanism, for example, is provided between the injection motor 350 and the screw 330 to convert the rotational motion of the injection motor 350 into linear motion of the screw 330. The motion conversion mechanism, for example, includes a screw shaft and a screw nut threadedly engaged with the screw shaft. Balls, rollers, or the like may be provided between the screw shaft and the screw nut. The drive source for advancing and retracting the screw 330 is not limited to the injection motor 350; for example, a hydraulic cylinder may be provided.

[0081] 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 provided in the load transmission path between the injection motor 350 and the screw 330, and detects the load acting on the load detector 360.

[0082] The load detector 360 transmits a signal of the detected load to the control device 700. The load detected by the load detector 360 is converted into a pressure acting between the screw 330 and the molding material, and is used to control and monitor the pressure applied to the molding material by the screw 330, the back pressure of the screw 330, and the pressure applied to the molding material from the screw 330.

[0083] The pressure detector for detecting the pressure of the molding material is not limited to the load detector 360; a conventional detector can be used. For example, a nozzle pressure sensor or a mold internal pressure sensor can be used. The nozzle pressure sensor is provided at the nozzle 320. The mold internal pressure sensor is provided inside the mold device 800.

[0084] The injection device 300 performs a metering process, a filling process, a pressure-maintaining process, etc. under the control of the control device 700. The filling process and the pressure-maintaining process can be collectively referred to as an injection process.

[0085] In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set speed, and the molding material is transported to the front along the spiral groove of the screw 330. As a result, the molding material is gradually melted. As the liquid molding material is transported to the front of the screw 330 and accumulates at the front of the cylinder 310, the screw 330 is retracted. For example, the rotation speed of the screw 330 is detected using a metering motor encoder 341. The metering motor encoder 341 detects the rotation of the metering motor 340 and sends a signal indicating its detection result to the control device 700. In addition, the screw speed detector that detects the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a conventional detector can be used.

[0086] During the metering process, to prevent the screw 330 from rapidly retreating, the injection motor 350 can be driven to apply a set back pressure to the screw 330. For example, the back pressure on the screw 330 can be detected using a load detector 360. The metering process ends when the screw 330 retreats to the metering end position and a predetermined amount of molding material accumulates in front of the screw 330.

[0087] The position and speed of screw 330 during the metering process are uniformly set as a series of setting conditions. For example, the metering start position, speed switching position, and metering end position are set. These positions are arranged in sequence from the front to the back and represent the start and end points of the speed setting interval. The speed is set for each interval. There can be one or more speed switching positions. The speed switching position does not need to be set. In addition, the back pressure is set for each interval.

[0088] In the filling process, the injection motor 350 is driven to make the screw 330 move forward at a set moving speed, and the liquid molding material accumulated in front of the screw 330 is filled into the cavity space 801 in the mold device 800. For example, the position and moving speed of the screw 330 are detected using the injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and sends a signal indicating its detection result to the control device 700. If the position of the screw 330 reaches the set position, the switch from the filling process to the pressure holding process is performed (the so-called V / P switching). The position where the V / P switching is performed is also called the V / P switching position. The set moving speed of the screw 330 can be changed according to the position of the screw 330, time, etc.

[0089] The position and movement speed of screw 330 during the filling process are uniformly set 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 sequence from the back to the front and represent the starting and ending points of the interval for setting the movement speed. The movement speed is set for each interval. There can be one or more movement speed switching positions. It is not necessary to set a movement speed switching position.

[0090] An upper limit value for the pressure of the screw 330 is set for each interval of the screw 330's travel speed. The pressure of the screw 330 is detected by a load detector 360. When the pressure of the screw 330 is below the set pressure, the screw 330 advances at the set travel speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, the screw 330 advances at a speed slower than the set travel speed to reduce the pressure of the screw 330 to below the set pressure in order to protect the mold.

[0091] Furthermore, during the filling process, after the screw 330 reaches the V / P switching position, the screw 330 can be paused at the V / P switching position before the V / P switching is performed. Alternatively, instead of stopping the screw 330 immediately before the V / P switching, the screw 330 can be moved forward or backward at a slight speed. Furthermore, the screw position detector for detecting the position of the screw 330 and the screw movement speed detector for detecting the movement speed of the screw 330 are not limited to the injection motor encoder 351; conventional detectors can be used.

[0092] In the holding pressure process, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") is maintained at the set pressure, and the molding material remaining in the cylinder 310 is pushed toward the mold device 800. The insufficient amount of molding material in the mold device 800 due to cooling shrinkage can be supplemented. For example, the holding pressure is detected using a load detector 360. The setting value of the holding pressure can be changed according to the time elapsed since the start of the holding pressure process. The holding pressure and the holding time of the holding pressure in multiple holding pressure processes can be set separately, or they can be set uniformly as a series of setting conditions.

[0093] During the pressure holding process, the molding material in the cavity space 801 within the mold device 800 gradually cools. At the end of the pressure holding process, the entrance to the cavity space 801 is sealed by the solidified molding material. This state is called gate sealing and prevents the molding material from flowing back out of the cavity space 801. After the pressure holding process, the cooling process begins. During the cooling process, the molding material in the cavity space 801 solidifies. To shorten the molding cycle time, a metering process can be performed during the cooling process.

[0094] While the injection device 300 of this embodiment employs a coaxial screw system, it may also employ a pre-molding system. Pre-molding system injection devices supply the molding material melted in a plasticizing cylinder to an injection cylinder, which then injects the molding material into the mold assembly. Within the plasticizing cylinder, the screw is configured to rotate freely and not advance or retreat, or to rotate freely and advance and retreat freely. Meanwhile, within the injection cylinder, the plunger is configured to advance and retreat freely.

[0095] Furthermore, while the injection unit 300 of 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 mold clamping unit used in conjunction with the vertical injection unit 300 may be either vertical or horizontal. Similarly, the mold clamping unit used in conjunction with the horizontal injection unit 300 may be either horizontal or vertical.

[0096] (Mobile device)

[0097] In the description of the moving device 400, similar to the description of the injection device 300, the moving direction of the screw 330 during filling (e.g., the negative direction of the X-axis) is set to the front, and the moving direction of the screw 330 during metering (e.g., the positive direction of the X-axis) is set to the rear.

[0098] The moving device 400 moves the injection device 300 forward and backward relative to the mold device 800. Furthermore, the moving device 400 presses the nozzle 320 against the mold device 800, generating nozzle contact pressure. The moving device 400 includes a hydraulic pump 410, a motor 420 as a drive source, and a hydraulic cylinder 430 as a hydraulic actuator.

[0099] The hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectionally rotatable pump. By switching the rotational direction of the motor 420, the hydraulic pump 410 draws hydraulic fluid (e.g., oil) from one of the first and second ports 411, 412 and discharges it from the other port, generating hydraulic pressure. Alternatively, the hydraulic pump 410 can draw hydraulic fluid from a tank and discharge it from either the first or second port 411, 412.

[0100] The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 with a rotation direction and a rotation torque corresponding to a control signal from the control device 700. The motor 420 may be an electric motor or an electric servomotor.

[0101] The hydraulic cylinder 430 includes 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 interior of the cylinder body 431 into a front chamber 435 serving as a first chamber and a rear chamber 436 serving as a second chamber. The piston rod 433 is fixed to the fixed platen 110.

[0102] The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via the first flow path 401. The hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow path 401, thereby pushing the injection device 300 forward. The injection device 300 advances, pressing the nozzle 320 against the fixed mold 810. The front chamber 435 functions as a pressure chamber that generates nozzle contact pressure on the nozzle 320 using the pressure of the hydraulic fluid supplied from the hydraulic pump 410.

[0103] 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 flow path 402. The hydraulic fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow path 402, thereby pushing the injection device 300 rearward. The injection device 300 retracts, and the nozzle 320 separates from the fixed mold 810.

[0104] In this embodiment, the moving device 400 includes the 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 linear motion of the injection device 300 may be used.

[0105] (Control device)

[0106] The control device 700 is constituted by a computer, for example. Figures 1 and 2 As shown, the control device 700 includes a CPU (Central Processing Unit) 701, a storage medium such as a memory 702, an input interface 703, and an output interface 704. The control device 700 performs various controls by causing the CPU 701 to execute programs stored in the storage medium 702. Furthermore, the control device 700 receives external signals via the input interface 703 and transmits signals to the outside via the output interface 704.

[0107] The control device 700 repeatedly produces molded products by performing a metering process, a mold closing process, a pressure increase process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a pressure release process, a mold opening process, and an ejection process. The series of operations required to produce a molded product, such as the process from the start of a metering process to the start of the next metering process, is also referred to as a "shot" or "molding cycle." Furthermore, the time required for one shot is also referred to as the "molding cycle time" or "cycle time."

[0108] A primary molding cycle, for example, sequentially includes a metering step, a mold closing step, a pressure increase step, a mold closing step, a filling step, a pressure holding step, a cooling step, a pressure release step, a mold opening step, and an ejection step. The order used here refers to the order in which each step begins. The filling step, the pressure holding step, and the cooling step occur during the mold closing step. Alternatively, the start of the mold closing step can coincide with the start of the filling step. The end of the pressure release step coincides with the start of the mold opening step.

[0109] In addition, in order to shorten the molding cycle time, multiple processes can be carried out simultaneously. For example, the metering process can be carried out during the cooling process of the previous molding cycle, or during the mold closing process. In this case, the mold closing process can be set to be carried out at the beginning of the molding cycle. In addition, the filling process can be started during the mold closing process. In addition, the ejection process can be started during the mold opening process. When an on-off valve is set to open and close the flow path of the nozzle 320, the mold opening process can be started during the metering process. Because even if the mold opening process is started during the metering process, as long as the on-off valve closes the flow path of the nozzle 320, the molding material will not leak from the nozzle 320.

[0110] In addition, a primary molding cycle may include processes other than the metering step, mold closing step, pressure increasing step, mold clamping step, filling step, pressure holding step, cooling step, pressure releasing step, mold opening step, and ejection step.

[0111] For example, a pre-metering backdraft process can be performed after the pressure holding process is completed and before the metering process begins, in which the screw 330 is retracted to a preset metering start position. This can reduce the pressure of the molding material accumulated in front of the screw 330 before the metering process begins, thereby preventing the screw 330 from rapidly retracting when the metering process begins.

[0112] Furthermore, a post-metering backsucking step may be performed after the metering step is completed and before the filling step begins, in which the screw 330 is retracted to a preset filling start position (also referred to as the "injection start position"). This can reduce the pressure of the molding material accumulated in front of the screw 330 before the filling step begins, thereby preventing leakage of the molding material from the nozzle 320 before the filling step begins.

[0113] The control device 700 is connected to an operating device 750 that receives user input operations and a display device 760 that displays a screen. The operating device 750 and the display device 760 are composed of, for example, a touch panel 770 and can be integrated. The touch panel 770, serving as the display device 760, displays a screen under the control of the control device 700. Information such as the settings of the injection molding machine 10 and the current status of the injection molding machine 10 can be displayed on the screen of the touch panel 770. Furthermore, operating units such as buttons and input fields for receiving user input operations can be displayed on the screen of the touch panel 770. The touch panel 770, serving as the operating device 750, detects user input operations on the screen and outputs signals corresponding to the input operations to the control device 700. Thus, for example, a user can operate the operating units provided on the screen while confirming information displayed on the screen to set the injection molding machine 10 (including inputting set values). Furthermore, by operating the operating units provided on the screen, the user can operate the injection molding machine 10 corresponding to the operating units. The operation of the injection molding machine 10 may include, for example, the operation (including stopping) of the mold clamping device 100, the ejection device 200, the injection device 300, the moving device 400, etc. Furthermore, the operation of the injection molding machine 10 may include switching of the screen displayed on the touch panel 770 serving as the display device 760.

[0114] In this embodiment, the operating device 750 and the display device 760 are integrated into a touch panel 770. However, they may be provided separately. Furthermore, multiple operating devices 750 may be provided. The operating device 750 and the display device 760 are disposed on the operating side (negative Y-axis direction) of the mold clamping unit 100 (more specifically, the fixed platen 110).

[0115] (1st switch and 2nd switch)

[0116] Next, refer to Figure 3 and Figure 4, an example of the safety door 600 of the injection molding machine 10 will be described. Figure 3 and Figure 4 The injection molding machine 10 is shown as a horizontal type, but may also be a vertical type. The injection molding machine 10 is provided with a safety door 600. The safety door 600 prevents workers from coming into contact with the mold device 800.

[0117] Safety door 600 is for example Figure 3 The open position shown is similar to that in Figure 4 The safety door 600 can be moved between the closed positions shown. The open position is a position that allows workers to contact the mold device 800. The closed position is a position that prevents workers from contacting the mold device 800. The movement of the safety door 600 can be manual or automatic.

[0118] Only when the safety door 600 is in the closed position can the mold clamping unit 100 close, increase pressure, clamp, release pressure, or open the mold assembly 800. When the safety door 600 is in the open position, the mold clamping unit 100 does not close, increase pressure, clamp, release pressure, or open the mold assembly 800, nor does it move the entire movable mold 820.

[0119] The safety door 600 has an opening 601 and a transparent plate 602 that closes the opening 601. When the safety door 600 is in the closed position, the worker can visually recognize the mold assembly 800 through the transparent plate 602. Therefore, the worker can visually recognize the mold assembly 800 closing, pressurization, clamping, depressurization, and opening of the mold assembly 800.

[0120] The injection molding machine 10 sometimes moves the movable member of the mold device 800 with the safety door 600 open. The movable member is, for example, the ejector plate 826 (see Figure 1 and Figure 2 ). The movable member is not limited to the ejector plate 826, and may be, for example, a rotating core or a sliding core.

[0121] Rotating cores are used, for example, when forming threads on molded products. Rotating the rotating core allows the threads of the molded product to be extracted from the rotating core. Sliding cores are used, for example, when forming undercuts such as horizontal holes or internal flanges in molded products. Retracting the sliding core allows the molded product to be ejected.

[0122] Furthermore, as described above, the injection molding machine 10 does not close, pressurize, clamp, release, or open the mold assembly 800 while the safety door 600 is open, nor does it move the entire movable mold 820. The movable member of the mold assembly 800 is part of the movable mold 820. Alternatively, the movable member of the mold assembly 800 is part of the fixed mold 810.

[0123] When the injection molding machine 10 operates the movable components of the mold assembly 800 with the safety door 600 open, it is necessary to prevent workers from coming into contact with the mold assembly 800 using a method separate from the safety door 600. Therefore, the injection molding machine 10 includes an operating device 750. The operating device 750 is used to permit the operation of the movable components of the mold assembly 800. This permission can be granted by the operating device 750 or by the control device 700, which receives a signal corresponding to the operating status of the operating device 750. The worker who operates the operating device 750 is sometimes referred to as an operator.

[0124] like Figure 5 As shown, the operating device 750 includes a first switch 751 operated by one hand (e.g., the left hand) and a second switch 752 operated by the other hand (e.g., the right hand). During the operation of the movable member of the mold device 800, the operator 20's hands are in contact with the operating device 750 and therefore cannot touch the mold device 800. The first switch 751 and the second switch 752 are separated by a distance that the operator 20 cannot operate with one hand and a distance that the operator 20 can operate with both hands. This distance is not particularly limited, but from an ergonomic perspective, it is preferably 260 mm to 600 mm.

[0125] The first switch 751 has a first operating portion 751a that detects an open state and a closed state in which the force of the operator 20 is stronger or weaker than the open state. The first switch 751 is, for example, a position switch that changes position according to the force of the operator 20. The position includes an angle. The contacts of the position switch are opened and closed according to the position of the first operating portion 751a. In the case where the first switch 751 is a position switch, the first operating portion 751a moves between an open position and a closed position that exists only on one side of the open position. In this embodiment, the first switch 751 is a push button switch, but it can also be a lever switch, a handle switch, a dial switch, a rotary switch, etc.

[0126] The second switch 752 has a second operating portion 752a that detects an open state, a closed state in which the force of the operator 20 is stronger than the open state, and a closed state in which the force of the operator 20 is weaker than the open state. The second switch 752 is, for example, a position switch that changes its position according to the force of the operator 20. The position includes an angle. The contacts of the position switch are opened and closed according to the position of the second operating portion 752a. In the case where the second switch 752 is a position switch, the second operating portion 752a moves between an open position and two closed positions separated by the open position. In this embodiment, the second switch 752 is a push button switch, but it can also be a lever switch, a handle switch, a dial switch, a rotary switch, etc.

[0127] In addition, at least one of the first switch 751 and the second switch 752 may be a position switch. Furthermore, at least one of the first switch 751 and the second switch 752 may be a pressure switch. A pressure switch generates an electrical signal according to the force of the operator. A pressure switch includes, for example, a pressure sensor. The pressure sensor includes a diaphragm or a strain gauge, etc. In the case where the first switch 751 is a pressure switch, the first operating part 751a may not change its position. Similarly, if the second switch 752 is a pressure switch, the second operating part 752a may not change its position. The first switch 751 and the second switch 752 may be conventional switches and are not limited to position switches and pressure switches.

[0128] The movement of the movable member of the mold device 800 is permitted only when the first operating portion 751a and the second operating portion 752a are simultaneously in an open state (e.g., in the open position). Permitting the movement of the movable member includes, for example, supplying current to a drive device that drives the movable member. When at least one of the first operating portion 751a and the second operating portion 752a is in a closed state (e.g., in the closed position), the movement of the movable member of the mold device 800 is not permitted.

[0129] The movement of the movable member of the mold device 800 is permitted only when both the first operating portion 751a and the second operating portion 752a are in the open state (e.g., the open position). Even if an unexpected abnormality occurs during the movement of the movable member of the mold device 800, such as the operator 20 reflexively pressing the first switch 751 and the second switch 752 with both hands, causing an operational error, the second operating portion 752a will move to the closed position. Therefore, the movement of the movable member of the mold device 800 can be appropriately stopped.

[0130] While it is possible to use a three-position type for both the first switch 751 and the second switch 752, in this embodiment, the three-position type is used only for the second switch 752. A three-position type is more complex than a two-position type, and therefore more expensive. Using only the three-position type for the second switch 752 can reduce the cost of the operating device 750.

[0131] Multiple actions can be permitted by operating the operating device 750. Examples of permitted actions include retreat of the ejector plate 826, rotation of the rotary core, and sliding of the slide core. If multiple actions are permitted by operating the operating device 750, a first switch 751 is preferably provided for each action, and a second switch 752 is preferably provided for multiple actions. This can reduce the number of three-position types, further reducing the cost of the operating device 750. This also allows for miniaturization.

[0132] like Figure 3 and Figure 4 As shown, the first switch 751 and the second switch 752 are preferably arranged at positions where the operator can visually recognize the mold device 800 during the operation of the movable member of the mold device 800. Even if an unexpected abnormality occurs during the operation of the movable member of the mold device 800, the operator can visually confirm the status of the mold device 800.

[0133] The first switch 751 is preferably located closer to the mold device 800 than the second switch 752. When an unexpected abnormality occurs in the movement of a movable member of the mold device 800, a sound may be generated in the mold device 800. The operator reflexively moves the hand (e.g., left hand) that is close to the sound away from the sound.

[0134] The hand farther from the sound is less likely to move away from the operating device 750 than the hand closer to the sound. Therefore, it is preferable that the hand farther from the sound operate the three-position second switch 752, and the hand closer to the sound operate the two-position first switch 751. Therefore, it is preferable that the first switch 751 be located closer to the mold device 800 than the second switch 752.

[0135] like Figure 3 and Figure 4 As shown, the first switch 751 and the second switch 752 are preferably arranged at different heights. This allows the operator to visually confirm the positions of the first and second switches 751, 752 when operating them. This reminds the operator of the action to be performed. The action is displayed near the first and second switches 751, 752 in the form of text or symbols.

[0136] The height of the second switch 752 can be higher or lower than that of the first switch 751. At least one of the first and second switches 751 and 752 is preferably located at or above the operator's shoulder height. Specifically, the height from the floor 2 of the injection molding machine 10 is preferably 140 cm or higher. If an unexpected abnormality occurs during the operation of the movable member of the mold apparatus 800, the operator can be encouraged to lower their hands before approaching the mold apparatus 800. Giving the operator time to lower their hands allows the operator to calm down.

[0137] like Figure 5 As shown, the first switch 751 and the second switch 752 can be arranged on surfaces facing the same direction. For example, the first surface 758 on which the first switch 751 is arranged can be parallel to the second surface 759 on which the second switch 752 is arranged. The operator 20 operates the first switch 751 and the second switch 752 in the same direction.

[0138] In addition, if Figure 6As shown, the first switch 751 and the second switch 752 can also be arranged on surfaces with different orientations. For example, the first surface 758 on which the first switch 751 is arranged can be perpendicular to the second surface 759 on which the second switch 752 is arranged. When operating the first switch 751 and the second switch 752, the operator 20 visually confirms their positions. This allows the operator 20 to be reminded of the details of the next action to be performed.

[0139] And, as Figure 7 As shown, operating device 750 may include a third switch 753 in addition to first switch 751 and second switch 752. Third switch 753 is operated by the foot instead of the hand. As long as only one of first switch 751, second switch 752, and third switch 753 is a three-position type, all switches may be three-position types.

[0140] The third switch 753 may include a third operating portion 753a that detects an open state, a closed state in which the force of the operator 20 is stronger than the open state, and a closed state in which the force of the operator 20 is weaker than the open state. The third switch 753 is, for example, a position switch that changes position according to the force of the operator 20. The position includes an angle. The contacts of the position switch are opened and closed according to the position of the third operating portion 753a. In the case where the third switch 753 is a position switch, the third operating portion 753a moves between an open position and two closed positions sandwiching the open position. In the case where the third switch 753 is a three-position type, the first switch 751 and the second switch 752 may each be a two-position type.

[0141] Furthermore, at least one of the first switch 751, the second switch 752, and the third switch 753 may be a position switch. Furthermore, at least one of the first switch 751, the second switch 752, and the third switch 753 may be a pressure switch. If the third switch 753 is a pressure switch, the third operating portion 753a does not need to change position. The first switch 751, the second switch 752, and the third switch 753 may be conventional switches and are not limited to position switches or pressure switches.

[0142] Only when the first operating portion 751a, the second operating portion 752a, and the third operating portion 753a are simultaneously in the open state (e.g., the open position) is the movement of the movable member of the mold device 800 permitted. When at least one of the first operating portion 751a, the second operating portion 752a, and the third operating portion 753a is in the closed state (e.g., the closed position), the movement of the movable member of the mold device 800 is not permitted.

[0143] Multiple actions can be permitted by operating the operating device 750. Preferably, the first switch 751 is provided for each action, and preferably, the second switch 752 and the third switch 753 are provided for multiple actions. This can reduce the number of switches and thus the cost of the operating device 750. In addition to reducing costs, it also allows for miniaturization.

[0144] While the embodiments of the injection molding machine according to the present invention have been described above, the present invention is not limited to the aforementioned embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the technical proposals. These are naturally within the technical scope of the present invention.

Claims

1. An injection molding machine comprising an operating device for permitting movement of a movable member of a mold device, wherein: The operating device includes a first switch operated by one hand and a second switch operated by the other hand. The first switch has a first operating portion for detecting an open state and a closed state in which the operator's force is stronger or weaker than the open state. The second switch has a second operating portion for detecting an open state, a closed state in which the operator's force is stronger than the open state, and a closed state in which the operator's force is weaker than the open state. The movement of the movable member is permitted only when the first operating portion and the second operating portion are simultaneously in the open state.

2. The injection molding machine according to claim 1, wherein At least one of the first switch and the second switch is a position switch whose position changes according to a force exerted by an operator.

3. The injection molding machine according to claim 1, wherein At least one of the first switch and the second switch is a pressure switch that generates an electric signal in response to a force exerted by an operator.

4. The injection molding machine according to any one of claims 1 to 3, wherein There are multiple actions, the first switch is provided for each action, and one second switch is provided for multiple actions.

5. The injection molding machine according to any one of claims 1 to 3, wherein The first switch and the second switch are arranged at different heights.

6. The injection molding machine according to any one of claims 1 to 3, wherein The first switch is arranged at a position closer to the mold device than the second switch.

7. An injection molding machine comprising an operating device for permitting the movement of a movable member of a mold device, wherein: The operating device includes a first switch operated by one hand, a second switch operated by the other hand, and a third switch operated by one foot. The first switch has a first operating portion for detecting an open state and a closed state in which the operator's force is stronger or weaker than the open state. The second switch has a second operating portion for detecting an open state and a closed state in which the operator's force is stronger or weaker than the open state. The third switch has a third operating portion for detecting an open state, a closed state in which the operator's force is stronger than the open state, and a closed state in which the operator's force is weaker than the open state. The movement of the movable member is permitted only when the first operating portion, the second operating portion, and the third operating portion are simultaneously in the open state.

8. The injection molding machine according to claim 7, wherein: At least one of the first switch, the second switch, and the third switch is a position switch whose position changes according to a force exerted by an operator.

9. The injection molding machine according to claim 7, wherein: At least one of the first switch, the second switch, and the third switch is a pressure switch that generates an electric signal in response to a force exerted by an operator.

10. The injection molding machine according to any one of claims 7 to 9, wherein There are a plurality of actions, the first switch is provided for each of the actions, and the second switch and the third switch are provided in common for the plurality of actions.

11. The injection molding machine according to any one of claims 7 to 9, wherein The first switch and the second switch are arranged at different heights.

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