CN116890438A - Injection molding machine, heat limiting member, and heat input suppressing method - Google Patents

Abstract

The present application provides a technique capable of reducing heat input to a connection rod. The injection molding machine moves a movable platen provided with a movable mold along a connecting rod with respect to a fixed platen provided with a fixed mold to open and close the fixed mold and the movable mold. The injection molding machine has a thermal restriction portion that restricts movement of air heated to room temperature or above around the connecting rod to the connecting rod.

Description

Injection molding machine, heat limiting member, and heat input suppressing method

Technical Field

The present application claims priority based on japanese patent application No. 2022-060288 filed on 3 months of 2022, 31. The entire contents of this japanese application are incorporated by reference into the present specification.

The present application relates to an injection molding machine, a heat limiting member, and a heat input suppressing method.

Background

The mold device provided in the injection molding machine supplies and discharges the temperature control medium through the pipe, thereby adjusting the temperature to a temperature required for the molded product. The heat of the mold device is transferred to the tie bar, for example, via a platen (fixed platen, movable platen), thereby affecting the elongation of the tie bar when the mold clamping force is generated.

Accordingly, patent document 1 proposes a structure in which a heat insulating material is interposed between a platen and a link in the platen, thereby suppressing direct heat transfer from the platen to the link.

Patent document 1: japanese patent laid-open No. 2008-296384

However, it is not easy to select a heat insulating member which can withstand the load applied when the mold device is closed and has a high heat insulating effect. In injection molding in an injection molding machine, the mold device and the piping heat the air around the mold device and the piping. In the injection molding machine disclosed in patent document 1, the connecting rod extends in a state of being exposed from the platen. Therefore, the heat of the air heated by the die device and the piping is directly input to the connecting rod.

In particular, the amount of heat input to the 4 tie bars varies depending on the shape of the mold, the position of the piping, and the like. Therefore, the elongation of the 4 tie bars becomes uneven with each other and the clamping force becomes unstable, which may have a large influence on the molding of the molded article.

Disclosure of Invention

The invention provides a technology capable of stabilizing molding accuracy by suppressing the extension of a connecting rod by heating through air.

An aspect of the present invention is an injection molding machine that performs opening and closing of a fixed mold and a movable mold by moving a movable platen provided with the movable mold along a connecting rod with respect to a fixed platen provided with the fixed mold, the injection molding machine including a heat restricting portion that restricts movement of air heated to room temperature or higher around the connecting rod to the connecting rod.

In another aspect of the present invention, the thermal regulating member is attached to an injection molding machine that moves a movable platen provided with a movable mold along a connecting rod with respect to a fixed platen provided with the fixed mold to open and close the fixed mold and the movable mold, and the thermal regulating member regulates movement of air heated to room temperature or higher around the connecting rod to the connecting rod in a state of being attached to the connecting rod.

In the injection molding machine according to the present invention, the movable platen provided with the movable mold is moved along the connecting rod with respect to the fixed platen provided with the fixed mold, and the opening and closing of the fixed mold and the movable mold are performed, and the heat input to the connecting rod is restricted.

Effects of the invention

The injection molding machine, the heat restricting member, and the heat input suppressing method according to the present invention can suppress the connecting rod from being heated by air to extend, thereby stabilizing molding accuracy.

Drawings

Fig. 1 is a diagram showing a state at the end of mold opening of an injection molding machine according to an embodiment.

Fig. 2 is a diagram showing a state at the time of mold closing of the injection molding machine according to the embodiment.

Fig. 3 is a schematic view schematically showing a support side of a stationary mold in the mold clamping apparatus.

Fig. 4 is a view showing the installation of the heat restricting portion to the connecting rod.

Fig. 5 is a diagram schematically showing a thermal limiter according to a modification.

In the figure: 10-injection molding machine, 110-fixed platen, 120-movable platen, 140-connecting rod, 142-thermal limiter, 810-stationary mold, 820-movable mold.

Detailed Description

The mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference numerals, and overlapping description thereof may be omitted.

(injection Molding machine)

Fig. 1 is a diagram showing a state at the end of mold opening of an injection molding machine according to an embodiment. Fig. 2 is a diagram showing a state at the time of mold closing of the injection molding machine according to the embodiment. In the present specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are directions perpendicular to each other. The X-axis direction and the Y-axis direction represent horizontal directions, and the Z-axis direction represents vertical directions. When the mold clamping device 100 is horizontal, the X-axis direction is the mold opening/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 referred to as the operation side, and the positive side in the Y-axis direction is referred to as the opposite side to the operation side.

As shown in fig. 1 to 2, the injection molding machine 10 includes: a mold clamping device 100 for opening and closing the mold device 800; an ejector 200 for ejecting the molded article molded by the mold device 800; an injection device 300 injecting a molding material to the mold device 800; a moving device 400 for advancing and retreating the injection device 300 with respect to the mold device 800; a control device 700 for controlling the respective constituent elements of the injection molding machine 10; and a frame 900 for supporting the 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 device frame 920 supporting the injection device 300. The mold clamping device frame 910 and the injection device frame 920 are respectively provided on the bottom plate 2 via horizontal adjustment casters 930. The control device 700 is disposed in the internal space of the injection device frame 920. The following describes the respective constituent elements of the injection molding machine 10.

(mold clamping device)

In the description of the mold clamping apparatus 100, the moving direction (for example, the positive X-axis direction) of the movable platen 120 during mold closing is set to the front, and the moving direction (for example, the negative X-axis direction) of the movable platen 120 during mold opening is set to the rear.

The mold clamping device 100 performs mold closing, pressure increasing, mold clamping, pressure releasing, and mold opening of the mold device 800. The mold apparatus 800 includes a stationary mold 810 and a movable mold 820.

The mold clamping device 100 is, for example, horizontal, and the mold opening/closing direction is horizontal. The mold clamping device 100 includes a fixed platen 110 to which a fixed mold 810 is attached, a movable platen 120 to which a movable mold 820 is attached, and a moving mechanism 102 that moves the movable platen 120 relative to the fixed platen 110 in a mold opening/closing direction.

The stationary platen 110 is fixed relative to the clamp frame 910. A stationary mold 810 is mounted on a surface of the stationary platen 110 opposite to the movable platen 120.

The movable platen 120 is disposed so as to be movable in the mold opening/closing direction with respect to the mold clamping device frame 910. A guide 101 for guiding the movable platen 120 is laid on the mold clamping device frame 910. The movable mold 820 is attached to a surface of the movable platen 120 facing the fixed platen 110.

The moving mechanism 102 performs mold closing, pressure increasing, mold closing, pressure releasing, and mold opening of the mold apparatus 800 by advancing and retracting the movable platen 120 relative to the fixed platen 110. The moving mechanism 102 includes a toggle base 130 disposed at a distance from the fixed platen 110, a link 140 connecting the fixed platen 110 and the toggle base 130, a toggle mechanism 150 moving the movable platen 120 relative to the toggle base 130 in the mold opening/closing direction, a mold clamping motor 160 operating the toggle mechanism 150, a motion conversion mechanism 170 converting the rotational motion of the mold clamping motor 160 into a linear motion, and a mold thickness adjustment mechanism 180 adjusting the distance between the fixed platen 110 and the toggle base 130.

The toggle seat 130 is disposed at a distance from the fixed platen 110, and is mounted on the clamping device frame 910 so as to be movable in the mold opening/closing direction. The toggle mount 130 may be configured to be movable along a guide provided on the clamp frame 910. The guide of the toggle seat 130 may be common to the guide 101 of the movable platen 120.

In the present embodiment, the stationary platen 110 is fixed to the clamping device frame 910, and the toggle mount 130 is disposed so as to be movable in the mold opening and closing direction with respect to the clamping device frame 910, but the toggle mount 130 may be fixed to the clamping device frame 910, and the stationary platen 110 may be disposed so as to be movable in the mold opening and closing direction with respect to the clamping device frame 910.

The connecting rod 140 connects the fixed platen 110 and the toggle base 130 with a space L therebetween in the mold opening and closing direction. The connecting rods 140 are provided at 4 corners of the fixed platen 110, respectively, and 4 connecting rods are provided in total. The number of the connection bars 140 is not particularly limited, and 1 or more connection bars may be provided.

The 4 tie bars 140 are arranged parallel to the mold opening and closing direction and extend according to the mold clamping force. A link strain detector 141 detecting strain of the link 140 may be provided on at least 1 link 140. The link strain detector 141 transmits a signal indicating the detection result to the control device 700. The detection result of the tie bar strain detector 141 is used for detection of the clamping force or the like.

In the present embodiment, the tie bar strain detector 141 is used as a mold clamping force detector for detecting a mold clamping force, but the present invention is not limited thereto. The mold clamping force detector is not limited to the strain gauge type, but may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, or the like, and the mounting position thereof is not limited to the tie bar 140.

The toggle mechanism 150 is disposed between the movable platen 120 and the toggle base 130, and moves the movable platen 120 with respect to the toggle base 130 in the mold opening and closing direction. The toggle mechanism 150 has a crosshead 151 that moves in the mold opening and closing direction, and a pair of link groups that are bent and extended by the movement of the crosshead 151. The pair of link groups includes a 1 st link 152 and a 2 nd link 153, which are connected to each other by a pin or the like so as to be freely bendable. The 1 st link 152 is attached to the movable platen 120 by a pin or the like so as to be swingable. The 2 nd link 153 is attached to the toggle base 130 by a pin or the like so as to be swingable. The 2 nd link 153 is attached to the crosshead 151 via the 3 rd link 154. When the crosshead 151 is advanced and retracted relative to the toggle mount 130, the 1 st link 152 and the 2 nd link 153 are extended and retracted to advance and retract the movable platen 120 relative to the toggle mount 130.

The structure of the toggle mechanism 150 is not limited to the structure shown in fig. 1 and 2. For example, in fig. 1 and 2, the number of nodes of each link group is 5, but may be 4, or one end of the 3 rd link 154 may be connected to the node of the 1 st link 152 and the 2 nd link 153.

The clamp motor 160 is mounted to the toggle mount 130 and operates the toggle mechanism 150. The clamp motor 160 advances and retreats the crosshead 151 with respect to the toggle mount 130, and stretches the 1 st link 152 and the 2 nd link 153 to advance and retreat the movable platen 120 with respect to the toggle mount 130. The mold clamping motor 160 is directly connected to the motion conversion mechanism 170, but may be connected to the motion conversion mechanism 170 via a belt, pulley, or the like.

The motion conversion mechanism 170 converts the rotational motion of the clamp motor 160 into a linear motion of the crosshead 151. The motion conversion mechanism 170 includes a screw shaft and a screw nut screwed with the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

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.

In the mold closing step, the movable platen 120 is advanced by driving the mold clamping motor 160 to advance the crosshead 151 to the mold closing end position at a set movement speed so that the movable mold 820 is brought into contact with the fixed mold 810. For example, the position and the moving speed of the crosshead 151 are detected using a clamp motor encoder 161 or the like. The clamp motor encoder 161 detects the rotation of the clamp motor 160, and transmits a signal indicating the detection result to the control device 700.

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 clamp motor encoder 161, and a conventional detector may be used. 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, and a conventional detector may be used.

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

In the mold clamping process, the mold clamping motor 160 is driven to maintain the position of the crosshead 151 at the mold clamping position. In the mold clamping step, the mold clamping force generated in the pressure increasing step is maintained. In the mold clamping step, a cavity space 801 (see fig. 2) is formed between the movable mold 820 and the fixed mold 810, and the injection device 300 fills the cavity space 801 with a liquid molding material. The filled molding material is cured, thereby obtaining a molded article.

The number of cavity spaces 801 may be 1 or more. In the latter case, a plurality of molded articles can be obtained at the same time. An insert may be disposed in a portion of the cavity space 801 and another portion of the cavity space 801 may be filled with molding material. A molded article in which the insert and the molding material are integrated can be obtained.

In the decompression step, the clamping motor 160 is driven to retract the crosshead 151 from the clamping position to the mold opening start position, and the movable platen 120 is retracted to reduce the clamping force. The mold opening start position and the mold closing end position may be the same position.

In the mold opening step, the movable platen 120 is retracted by driving the mold clamping motor 160 to retract the crosshead 151 from the mold opening start position to the mold opening end position at a set movement speed, so that the movable mold 820 is separated from the fixed mold 810. Then, the ejector 200 ejects the molded article from the mold 820.

The setting conditions in the mold closing step, the pressure increasing step, and the mold closing step are set in a unified manner as a series of setting conditions. For example, the moving speed, the 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 step and the pressure increasing step are set in a unified manner as a series of setting conditions. The mold closing start position, the moving speed switching position, the mold closing end position, and the mold closing position are arranged in this order from the rear side to the front side, and indicate the start point and the end point of the section in which the moving speed is set. The movement speed is set for each section. The number of the movement speed switching positions may be 1 or plural. The moving speed switching position may not be set. Only one of the mold clamping position and the mold clamping force may be set.

The conditions for setting in the decompression step and the mold opening step are set in the same manner. For example, the moving speed and the position (the mold opening start position, the moving speed switching position, and the mold opening end position) of the crosshead 151 in the decompression step and the mold opening step are set in a unified manner as a series of setting conditions. The mold opening start position, the movement speed switching position, and the mold opening end position are arranged in this order from the front side to the rear side, and indicate the start point and the end point of the section in which the movement speed is set. The movement speed is set for each section. The number of the movement speed switching positions may be 1 or plural. The moving speed switching position may not be set. The mold opening start position and the mold closing end position may be the same position. The mold opening end position and the mold closing start position may be the same position.

In addition, instead of the moving speed, position, etc. of the crosshead 151, the moving speed, position, etc. of the movable platen 120 may be set. In addition, the clamping force may be set instead of the position of the crosshead (for example, the clamping position) and the position of the movable platen.

However, the toggle mechanism 150 amplifies the driving force of the clamp motor 160 and transmits it to the movable platen 120. Its magnification is also called toggle magnification. The toggle magnification changes according to an angle θ (hereinafter, also referred to as "link angle θ") formed by the 1 st link 152 and the 2 nd link 153. The link angle θ is obtained from the position of the crosshead 151. When the link angle θ is 180 °, the toggle magnification becomes maximum.

When the thickness of the mold device 800 changes due to replacement of the mold device 800, temperature change of the mold device 800, or the like, mold thickness adjustment is performed to obtain a predetermined clamping force at the time of clamping. In the die thickness adjustment, for example, the distance L between the fixed platen 110 and the toggle base 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle at the time when the movable die 820 contacts the fixed die 810.

The mold clamping device 100 has a mold thickness adjusting mechanism 180. The die thickness adjustment mechanism 180 adjusts the distance L between the fixed platen 110 and the toggle base 130, thereby performing die thickness adjustment. The timing of the mold thickness adjustment is performed, for example, during a period from the end of the molding cycle to the start of the next molding cycle. The die thickness adjusting mechanism 180 includes, for example: a screw shaft 181 formed at a rear end portion of the connection rod 140; a screw nut 182 rotatably held in the toggle seat 130 and being non-retractable; and a die thickness adjusting motor 183 for rotating a screw nut 182 screwed to the screw shaft 181.

A screw shaft 181 and a screw nut 182 are provided for each of the connection rods 140. The rotational driving force of the die thickness adjusting motor 183 may be transmitted to the plurality of lead screw nuts 182 via the rotational driving force transmitting portion 185. A plurality of lead screw nuts 182 can be rotated synchronously. Further, by changing the transmission path of the rotational driving force transmission unit 185, the plurality of lead screw nuts 182 can be rotated individually.

The rotational driving force transmitting portion 185 is constituted by a gear or the like, for example. At this time, driven gears are formed on the outer periphery of each screw nut 182, a driving gear is mounted on the output shaft of the die thickness adjusting motor 183, and an intermediate gear engaged with the driven gears and the driving gear is rotatably held at the center portion of the toggle seat 130. In addition, the rotational driving force transmitting portion 185 may be formed of a belt, a pulley, or the like instead of the gear.

The operation of the die thickness adjusting mechanism 180 is controlled by the control device 700. The control device 700 drives the die thickness adjustment motor 183 to rotate the lead screw nut 182. As a result, the position of the toggle housing 130 relative to the connecting rod 140 is adjusted, and the interval L between the fixed platen 110 and the toggle housing 130 is adjusted. In addition, a plurality of die thickness adjusting mechanisms may be used in combination.

The interval L is detected using a die thickness adjustment motor encoder 184. The die thickness adjustment motor encoder 184 detects the rotation amount and rotation direction of the die thickness adjustment motor 183, and transmits a signal indicating the detection result to the control device 700. The detection result of the die thickness adjustment motor encoder 184 is used to monitor and control the position of the toggle seat 130, the spacing L. The toggle seat position detector for detecting the position of the toggle seat 130 and the interval detector for detecting the interval L are not limited to the die thickness adjusting motor encoder 184, and a conventional detector may be used.

The mold clamping device 100 may have a mold temperature regulator that regulates the temperature of the mold device 800. The die device 800 has a flow path for the temperature control 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.

The mold clamping device 100 of the present embodiment is a horizontal mold opening/closing direction, but may be a vertical mold opening/closing direction.

The mold clamping device 100 of the present embodiment includes the mold clamping motor 160 as a driving unit, but may include a hydraulic cylinder instead of the mold clamping motor 160. The mold clamping device 100 may include a linear motor for mold opening and closing, or may include an electromagnet for mold clamping.

(ejector device)

In the description of the ejector 200, the moving direction (for example, the positive X-axis direction) of the movable platen 120 during mold closing is set to the front, and the moving direction (for example, the negative X-axis direction) of the movable platen 120 during mold opening is set to the rear, similarly to the description of the mold clamping device 100 and the like.

The ejector 200 is attached to the movable platen 120 and advances and retreats together with the movable platen 120. The ejector 200 includes: an ejector rod 210 ejecting the molded article from the mold device 800; and a driving mechanism 220 for moving the ejector rod 210 in the moving direction (X-axis direction) of the movable platen 120.

The ejector rod 210 is disposed so as to be movable in and out of 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 tip end of the ejector rod 210 may or may not be connected to the ejector plate 826.

The driving mechanism 220 includes, for example, an ejector motor and a motion conversion mechanism that converts rotational motion of the ejector motor into linear motion of the ejector rod 210. The motion conversion mechanism comprises a screw shaft and a screw nut screwed with the screw shaft. Balls or rollers may be interposed between the screw shaft and the screw nut.

The ejector 200 performs the ejection process under the control of the control device 700. In the ejection step, the ejector rod 210 is advanced from the standby position to the ejection position at a set movement speed, and the ejector plate 826 is advanced to eject the molded article. Then, the ejector motor is driven to retract the ejector rod 210 at a set movement speed, and the ejector plate 826 is retracted to the original standby position.

The position and moving 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 transmits a signal indicating the detection result to the control device 700. The ejector rod position detector that detects the position of the ejector rod 210 and the ejector rod movement speed detector that detects the movement speed of the ejector rod 210 are not limited to the ejector motor encoder, and a conventional detector may be used.

(injection device)

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

The injection device 300 is provided on the slide base 301, and the slide base 301 is disposed so as to be movable relative to the injection device frame 920. The injection device 300 is disposed so as to be movable in and out of the mold device 800. The injection device 300 is in contact with the mold device 800 and fills the cavity space 801 in the mold device 800 with molding material. The injection device 300 includes, for example, a cylinder 310 for heating a molding material, a nozzle 320 provided at a distal end portion of the cylinder 310, a screw 330 rotatably disposed in the cylinder 310, a metering motor 340 for rotating the screw 330, an injection motor 350 for advancing and retreating the screw 330, and a load detector 360 for detecting a load transmitted between the injection motor 350 and the screw 330.

The cylinder 310 heats the molding material supplied from the supply port 311 to the inside. The molding material includes, for example, a resin or the like. The molding material is formed into, for example, a pellet shape, and is supplied in a solid state to the supply port 311. The supply port 311 is formed at the rear of the cylinder 310. A cooler 312 such as a water-cooled cylinder is provided on the outer periphery of the rear portion of the cylinder block 310. A 1 st heater 313 such as a belt heater and a 1 st temperature detector 314 are provided on the outer periphery of the cylinder 310 in front of the cooler 312.

The cylinder 310 is divided into a plurality of regions along an axial direction (e.g., an X-axis direction) of the cylinder 310. The 1 st heater 313 and the 1 st temperature detector 314 are provided in each of the plurality of regions. The control device 700 controls the 1 st heater 313 so that the temperature detected by the 1 st temperature detector 314 becomes the set temperature.

The nozzle 320 is provided at the front end of the cylinder 310, and presses the die device 800. A 2 nd heater 323 and a 2 nd temperature detector 324 are provided on the outer periphery of the nozzle 320. The control device 700 controls the 2 nd heater 323 so that the detected temperature of the nozzle 320 becomes the set temperature.

The screw 330 is rotatably disposed in the cylinder 310 and is movable forward and backward. When the screw 330 is rotated, the molding material is conveyed forward along the spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 while being conveyed forward. As the molding material in the liquid state is conveyed to the front of the screw 330 and accumulated in 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 in the mold device 800.

The check ring 331 is attached to the front of the screw 330 so as to be movable forward and backward, and the check ring 331 serves as a check valve to prevent the molding material from flowing backward from the front of the screw 330 when the screw 330 is pushed forward.

When the screw 330 is advanced, the check ring 331 is pushed rearward by the pressure of the molding material in front of the screw 330, and retreats relatively to the screw 330 to a closed position (see fig. 2) blocking the flow path of the molding material. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

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 relatively advances to the open position (refer to fig. 1) for opening the flow path of the molding material with respect to the screw 330. Thereby, the molding material is conveyed to the front of the screw 330.

Check ring 331 may be either a co-rotating type that rotates with screw 330 or a non-co-rotating type that does not rotate with screw 330.

In addition, the injection device 300 may have a driving source that advances and retreats the check ring 331 with respect to the screw 330 between the open position and the closed position.

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.

Injection motor 350 advances and retracts screw 330. A motion conversion mechanism or the like for converting the rotational motion of injection motor 350 into the linear motion of screw 330 is provided between injection motor 350 and screw 330. The motion conversion mechanism includes, for example, a screw shaft and a screw nut screwed to the screw shaft. Balls, rollers, etc. may be provided between the screw shaft and the screw nut. The driving source for advancing and retreating the screw 330 is not limited to the injection motor 350, and may be, for example, a hydraulic cylinder or the like.

The load detector 360 detects a 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 a transmission path of the load between the injection motor 350 and the screw 330, and detects the load acting on the load detector 360.

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 that the screw 330 receives from the molding material, the back pressure on the screw 330, the pressure acting on the molding material from the screw 330, and the like.

The pressure detector for detecting the pressure of the molding material is not limited to the load detector 360, and a conventional detector can be used. For example, a nozzle pressure sensor or an in-mold pressure sensor may be used. The nozzle pressure sensor is provided to the nozzle 320. The mold internal pressure sensor is provided inside the mold device 800.

The injection device 300 performs a metering process, a filling process, a pressure maintaining process, and the like under the control of the control device 700. The filling step and the pressure maintaining step may be collectively referred to as an injection step.

In the metering step, the metering motor 340 is driven to rotate the screw 330 at a set rotational speed, and the molding material is conveyed forward along the spiral groove of the screw 330. Thereby, the molding material is gradually melted. As the molding material in the liquid state is conveyed to the front of the screw 330 and accumulated in the front of the cylinder 310, the screw 330 is retracted. The rotational speed of screw 330 is detected, for example, using a metering motor encoder 341. The metering motor encoder 341 detects the rotation of the metering motor 340 and transmits a signal indicating the detection result to the control device 700. The screw rotation speed detector for detecting the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a conventional detector can be used.

In the metering step, injection motor 350 may be driven to apply a set back pressure to screw 330 in order to limit rapid retraction of screw 330. The back pressure on the screw 330 is detected, for example, using a load detector 360. When the screw 330 is retracted to the metering end position and a predetermined amount of molding material is accumulated in front of the screw 330, the metering process ends.

The position and rotation speed of the screw 330 in the metering step are set uniformly as a series of setting conditions. For example, a measurement start position, a rotation speed switching position, and a measurement end position are set. These positions are arranged in order from the front side to the rear side, and indicate the start point and the end point of the section in which the rotational speed is set. The rotational speed is set for each section. The number of rotational speed switching positions may be 1 or a plurality of rotational speed switching positions. The rotational speed switching position may not be set. Back pressure is set for each section.

In the filling step, the injection motor 350 is driven to advance the screw 330 at a set moving speed, and the cavity space 801 in the mold apparatus 800 is filled with the liquid molding material stored in front of the screw 330. The position and moving speed of the screw 330 are detected, for example, using the injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and transmits a signal indicating the detection result thereof to the control device 700. When the position of the screw 330 reaches the set position, the filling process is switched to the pressure maintaining process (so-called V/P switching). The position where the V/P switch is performed is also referred to as a V/P switch position. The set moving speed of the screw 330 may be changed according to the position, time, etc. of the screw 330.

The position and the moving speed of the screw 330 in the filling process are set uniformly as a series of setting conditions. For example, a filling start position (also referred to as an "injection start position"), a moving speed switching position, and a V/P switching position are set. These positions are arranged in this order from the rear side to the front side, and indicate the start point and the end point of the section in which the movement speed is set. The movement speed is set for each section. The number of the movement speed switching positions may be 1 or plural. The moving speed switching position may not be set.

The upper limit value of the pressure of the screw 330 is set for each section in which the moving speed of the screw 330 is set. 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 moving speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, the screw 330 is advanced at a movement speed slower than the set movement speed so that the pressure of the screw 330 becomes equal to or lower than the set pressure in order to protect the mold.

In the filling step, after the position of the screw 330 reaches the V/P switching position, the screw 330 may be suspended at the V/P switching position and then V/P switching may be performed. Instead of stopping the screw 330, the screw 330 may be advanced at a slight speed or retracted at a slight speed immediately before the V/P switching. 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, and a conventional detector may be used.

In the pressure maintaining step, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the tip end portion of the screw 330 (hereinafter, also referred to as "holding pressure") is maintained at a set pressure, so that the molding material remaining in the cylinder 310 is pushed to the mold device 800. An insufficient amount of molding material due to cooling shrinkage in the mold device 800 can be replenished. 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 pressure-maintaining process. The holding pressure and the holding time for holding the holding pressure in the plurality of holding pressure steps may be set individually or may be set collectively as a series of setting conditions.

In the pressure maintaining step, the molding material in the cavity space 801 in the mold device 800 is gradually cooled, and at the end of the pressure maintaining step, the inlet of the cavity space 801 is blocked by the solidified molding material. This state is called gate sealing, and prevents backflow of molding material from the cavity space 801. After the pressure maintaining process, a cooling process is started. In the cooling step, solidification of the molding material in the cavity space 801 is performed. The metering step may be performed in the cooling step in order to shorten the molding cycle time.

The injection device 300 of the present embodiment is of a coaxial screw type, but may be of a pre-molding type or the like. The injection device of the pre-molding method supplies the molding material melted in the plasticizing cylinder to the injection cylinder, and injects the molding material from the injection cylinder into the mold device. In the plasticizing cylinder, the screw is rotatably disposed so as not to advance and retreat, or the screw is rotatably disposed so as to advance and retreat. On the other hand, in the injection cylinder, the plunger is disposed so as to be movable forward and backward.

The injection device 300 of the present embodiment is a horizontal type in which the axial direction of the cylinder 310 is horizontal, but may be a vertical type in which the axial direction of the cylinder 310 is vertical. The mold clamping device combined with the vertical injection device 300 may be either vertical or horizontal. Similarly, the mold clamping device combined with the horizontal injection device 300 may be either horizontal or vertical.

(Mobile device)

In the description of the moving device 400, the moving direction of the screw 330 (for example, the X-axis negative direction) during filling is set to the front, and the moving direction of the screw 330 (for example, the X-axis positive direction) during metering is set to the rear, as in the description of the injection device 300.

The movement device 400 advances and retracts the injection device 300 relative to the mold device 800. The moving device 400 presses the nozzle 320 against the die device 800 to generate a nozzle contact pressure. The traveling apparatus 400 includes a hydraulic pump 410, a motor 420 as a driving source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

The hydraulic pump 410 has a 1 st port 411 and a 2 nd port 412. The hydraulic pump 410 is a pump capable of rotating in both directions, and generates hydraulic pressure by switching the rotation direction of the motor 420 so that a working fluid (for example, oil) is sucked from one of the 1 st port 411 and the 2 nd port 412 and discharged from the other port. The hydraulic pump 410 may suck the working fluid from the tank and discharge the working fluid from any one of the 1 st port 411 and the 2 nd port 412.

The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 by 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 servo motor.

Hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. Cylinder body 431 is fixed relative to injection device 300. Piston 432 divides the interior of cylinder body 431 into a front chamber 435, which is the 1 st chamber, and a rear chamber 436, which is the 2 nd chamber. The piston rod 433 is fixed with respect to the fixed platen 110.

The front chamber 435 of the hydraulic cylinder 430 is connected to the 1 st port 411 of the hydraulic pump 410 via the 1 st flow path 401. The working fluid discharged from the 1 st port 411 is supplied to the front chamber 435 via the 1 st flow path 401, and the injection device 300 is pushed forward. The injection device 300 is advanced and the nozzle 320 is pressed against the stationary mold 810. The front chamber 435 functions as a pressure chamber that generates a nozzle contact pressure of the nozzle 320 by the pressure of the working fluid supplied from the hydraulic pump 410.

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the 2 nd port 412 of the hydraulic pump 410 via the 2 nd flow path 402. The working fluid discharged from the 2 nd port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the 2 nd flow path 402, whereby the injection device 300 is pushed rearward. The injection device 300 is retracted and the nozzle 320 is separated from the stationary mold 810.

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

(control device)

As shown in fig. 1 to 2, the control device 700 is configured by a computer, for example, and includes a CPU (Central Processing Unit (central processing unit)) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704. The control device 700 performs various controls by causing the CPU701 to execute a program stored in the storage medium 702. The control device 700 receives a signal from the outside through the input interface 703 and transmits a signal to the outside through the output interface 704.

The control device 700 repeatedly performs a metering process, a mold closing process, a pressure increasing process, a mold closing process, a filling process, a pressure maintaining process, a cooling process, a pressure releasing process, a mold opening process, an ejection process, and the like, to thereby repeatedly manufacture a molded product. A series of operations for obtaining a molded product, for example, an operation from the start of a metering process to the start of the next metering process is also referred to as "injection" or "molding cycle". The time required for one shot is also referred to as "molding cycle time" or "cycle time".

The one-shot molding cycle includes, for example, a metering step, a mold closing step, a pressure increasing step, a mold closing step, a filling step, a pressure maintaining step, a cooling step, a pressure releasing step, a mold opening step, and an ejection step in this order. The sequence here is the sequence in which the respective steps are started. The filling step, the pressure maintaining step, and the cooling step are performed during the mold clamping step. The start of the mold clamping process may be coincident with the start of the filling process. The end of the decompression step corresponds to the start of the mold opening step.

In addition, a plurality of steps may be performed simultaneously for the purpose of shortening the molding cycle time. For example, the metering step may be performed in the cooling step of the previous molding cycle, or may be performed during the mold clamping step. In this case, the mold closing step may be performed at the beginning of the molding cycle. The filling process may be started in the mold closing process. The ejection step may be started in the mold opening step. When an opening/closing valve for opening/closing the flow path of the nozzle 320 is provided, the mold opening process may be started in the metering process. Even if the mold opening process is started in the metering process, the molding material does not leak from the nozzle 320 as long as the opening/closing valve closes the flow path of the nozzle 320.

The one-shot molding cycle may include steps other than the metering step, the mold closing step, the pressure increasing step, the mold closing step, the filling step, the pressure maintaining step, the cooling step, the pressure releasing step, the mold opening step, and the ejection step.

For example, the pre-metering suck-back step of retracting the screw 330 to a preset metering start position may be performed after the end of the pressure maintaining step and before the start of the metering step. The pressure of the molding material stored in front of the screw 330 can be reduced before the start of the metering process, and the screw 330 can be prevented from rapidly backing up when the metering process is started.

After the completion of the metering step and before the start of the filling step, the post-metering suck-back step of retracting the screw 330 to a preset filling start position (also referred to as "injection start position") may be performed. The pressure of the molding material stored in front of the screw 330 can be reduced before the start of the filling process, and leakage of the molding material from the nozzle 320 can be prevented before the start of the filling process.

The control device 700 is connected to an operation device 750 that receives an input operation from a user and a display device 760 that displays a screen. The operation device 750 and the display device 760 are constituted by, for example, a touch panel 770, and may be integrated. The touch panel 770 as the display device 760 displays a screen under the control of the control device 700. Information such as the setting of the injection molding machine 10, the current state of the injection molding machine 10, and the like may be displayed on the screen of the touch panel 770. Further, an operation unit such as a button or an input field for receiving an input operation by a user may be displayed on the screen of the touch panel 770. The touch panel 770 as the operation device 750 detects an input operation of a user on a screen, and outputs a signal corresponding to the input operation to the control device 700. Thus, for example, the user can perform setting (including input of a set value) of the injection molding machine 10 by operating the operation unit provided on the screen while checking information displayed on the screen. The user can operate the operation unit provided on the screen, and thereby operate the injection molding machine 10 corresponding to the operation unit. The operation of the injection molding machine 10 may be, for example, the operations (including stopping) of the mold clamping device 100, the ejector 200, the injection device 300, the moving device 400, and the like. The operation of the injection molding machine 10 may be, for example, switching of a screen displayed on the touch panel 770 as the display device 760.

The operation device 750 and the display device 760 according to the present embodiment are integrated into the touch panel 770, but may be provided independently. Further, a plurality of operation devices 750 may be provided. The operation device 750 and the display device 760 are disposed on the operation side (Y-axis negative direction) of the mold clamping device 100 (more specifically, the stationary platen 110).

(Structure of connecting rod 140)

Next, the structure of the connecting rod 140 according to the present embodiment will be described with reference to fig. 3 and 4. Fig. 3 is a schematic view schematically showing a support side of the stationary mold 810 in the mold clamping apparatus 100, where fig. 3 (a) is a sectional view taken along line III-III of fig. 1, and fig. 3 (B) is a side view. Fig. 4 is a view showing the attachment of the thermal limiter 142 to the connecting rod 140, fig. 4 (a) is a perspective view, and fig. 4 (B) is an operation diagram at the time of attachment.

As described above, the mold clamping device 100 of the injection molding machine 10 includes 4 tie bars 140 extending between the fixed platen 110 and the toggle mount 130 (see fig. 1). The 4 connection rods 140 are disposed at the 4 corners of the fixed platen 110 and the 4 corners of the toggle seat 130, respectively. Each of the connection rods 140 is inserted into the hole portion in the fixed platen 110, and is firmly fixed by the fixing structure 146 on the back side of the fixed platen 110.

The connecting rod 140 is formed in a perfect circle shape having a predetermined diameter, for example, when viewed in a cross section orthogonal to the mold opening/closing direction. The connection rod 140 extends in a straight line while maintaining the diameter.

On the other hand, the movable platen 120 (see fig. 1) has through holes or notches, not shown, in 4 corners, through which the connecting rods 140 extending between the fixed platen 110 and the toggle base 130 pass.

A fixed mold 810 of the mold device 800 is provided at a central portion (between 4 connection bars 140) of the fixed platen 110. The fixed mold 810 is disposed in a noncontact manner with respect to each tie bar 140 at a position separated from each tie bar 140. The fixed mold 810 has a square shape when viewed in a cross section perpendicular to the mold opening/closing direction (fig. 3 a), but may have another shape such as a rectangular shape long in the vertical direction or the horizontal direction. Although not shown, a movable mold 820 of the mold apparatus 800 is provided at a central portion (between 4 tie bars 140) of the movable platen 120 so as to face the fixed mold 810.

The mold apparatus 800 includes a temperature adjustment mechanism 811 for adjusting the temperature of the stationary mold 810. The temperature adjustment mechanism 811 includes a temperature adjustment medium circulation device (not shown) and a pipe 812 (a temperature adjustment medium supply pipe 812a and a temperature adjustment medium discharge pipe 812 b) connecting the temperature adjustment medium circulation device and the fixed mold 810. The temperature-adjusting medium circulation device adjusts the temperature of the temperature-adjusting medium, and circulates the temperature-adjusted temperature-adjusting medium in the stationary mold 810. As the temperature adjusting medium, for example, water, liquid organic substances (oil, etc.), or a mixture thereof can be suitably used. The mold apparatus 800 may include a temperature adjustment mechanism in the movable mold 820 similar to the temperature adjustment mechanism 811 of the fixed mold 810. The mold device 800 is not limited to a structure for circulating the temperature control medium, and may be a device having a heater inside.

Each pipe 812 has a flow path therein through which a temperature control medium can flow. The temperature-adjusting medium supply pipe 812a supplies the temperature-adjusting medium from the temperature-adjusting medium circulation device to the stationary mold 810. The temperature-adjusting medium discharging pipe 812b returns the temperature-adjusting medium discharged from the stationary mold 810 to the temperature-adjusting medium circulating device. The piping 812 is connected to, for example, a side circumferential surface of the fixed mold 810 in the horizontal direction, and extends in the lateral direction (horizontal direction). That is, the temperature control medium supply pipe 812a and the temperature control medium discharge pipe 812b pass through between 2 connecting rods 140 arranged vertically.

In the injection molding machine 10 having the above configuration, the air around the fixed mold 810, the temperature control medium supply pipe 812a, and the temperature control medium discharge pipe 812b is heated to room temperature or higher. The heat generation of the stationary mold 810 is mainly caused by the high temperature resin filled in the stationary mold 810. The heat generation in the piping 812 is mainly caused by the circulated temperature control medium. In order to restrict the movement of the heated air to the connecting rod 140 (the heated air is in direct contact with the connecting rod 140), the injection molding machine 10 has a thermal restriction 142 around the connecting rod 140.

The thermal regulating portion 142 is provided on the outer peripheral surface of the connecting rod 140 extending outside the fixed platen 110 and the toggle seat 130. The thermal regulating portion 142 according to the illustrated example is directly and closely attached to the outer peripheral surface of the connecting rod 140, and a thermal regulating member 143 covering the entire circumferential direction of the outer peripheral surface is applied thereto. Although not shown, the link strain detector 141 is attached to an appropriate position of the link 140 so as to be exposed from the thermal restriction member 143 covering the link 140.

The heat restricting member 143 is made of a heat insulating material capable of being wound around the outer circumferential surface of the link 140. As the heat insulating material constituting the heat restricting member 143, for example, inorganic fibers such as glass wool, glass fiber, and ceramic fiber, or resin materials including fibers and porous materials can be applied. The thermal restriction member 143 may be a laminated structure in which a plurality of layers having different functions are laminated.

As shown in fig. 4 (a), the thermal restriction member 143 is formed in a cylindrical shape having an inner peripheral surface substantially conforming to the outer peripheral surface of the connecting rod 140. The thermal regulating member 143 may be elastically deformable so as to match the outer diameter of the connecting rod 140, or may have a hardness that can continuously maintain a cylindrical shape. Alternatively, the thermal restriction member 143 may be a member formed in a plate shape and wound around the connection rod 140. The thermal regulating member 143 may have a sealing structure (not shown) having an adhesive layer on a side surface contacting the outer circumferential surface of the connecting rod 140.

As shown in fig. 4 (B), the thermal restriction member 143 may be provided with an attachment structure 144 for a user of the injection molding machine 10 to perform an attachment/detachment operation, and may be attached to and detached from the connection rod 140. Accordingly, when the mold device 800 is provided for the fixed platen 110 and the movable platen 120, the thermal restriction member 143 can be removed and operated, and operability can be improved. The mounting structure 144 is constituted by, for example, a slit 144a formed at a predetermined circumferential position of the thermal restriction member 143 and a coupling member 144b for coupling the thermal restriction members 143 between the slits 144 a. That is, in the state before installation, the thermal restriction member 143 is formed in a C-shaped cross section with the slit 144a interposed therebetween, and can be configured as an elastic member that maintains the shape.

In addition, the thermal restriction member 143 may be formed to have a diameter larger than that of the outer circumferential surface of the connection rod 140 by one turn, and an inner circumferential surface thereof may form an air layer with the outer circumferential surface of the connection rod 140. The air layer may be a space or may be interposed between porous members. In other words, the thermal limiter 142 may have a non-contact structure (or a partially contact structure) with respect to the outer circumferential surface of the connecting rod 140.

The thermal limiter 142 may be formed by applying a heat insulating paint having a lower coefficient of thermal conductivity than the connecting rod 140 or a heat insulating paint to the outer peripheral surface of the connecting rod 140.

One end portion of the thermal restriction portion 142 provided on the connection rod 140 on the fixed platen 110 side is in contact with the fixed platen 110 without a gap. Thus, the tie bar 140 can be reliably not exposed at the periphery of the fixed mold 810. In addition, one end portion of the heat restricting portion 142 may be inserted into the inside of the fixed platen 110.

The thermal regulating portion 142 is continuous longer than the fixed mold 810 protruding from the fixed platen 110 toward the movable platen 120 side. The range of formation of the thermal restriction portion 142 in the axial direction of the connecting rod 140 is not particularly limited, but is preferably provided throughout the entire space between the fixed platen 110 and the movable platen 120, for example. More specifically, the other end of the thermal regulating portion 142 may reach the movable platen 120 disposed at the mold closing start position. Thus, the heat restricting portion 142 can reliably insulate the entire adjacent positions of the fixed mold 810 and the movable mold 820 in the mold closed state of the mold apparatus 800. The thermal regulating portion 142 can be formed so as not to contact the corner of the through hole or the notch constituting the movable platen 120 by appropriately adjusting the thickness thereof. Thus, the thermal regulating portion 142 does not hinder the mold closing and opening operations of the movable platen 120. The thermal regulating portion 142 may reduce the thickness of a portion that may come into contact with the movable platen 120 during movement of the movable platen 120, and may increase the thickness of a portion that does not come into contact with the movable platen 120 (e.g., a position near the fixed platen 110). In addition, the thermal limiter 142 may be provided throughout the entirety between the fixed platen 110 and the toggle seat 130.

The injection molding machine 10 and the heat restricting member 143 according to the present embodiment are basically configured as described above, and the operation (heat input suppressing method) and effects thereof will be described below.

The injection molding machine 10 performs a metering process, a mold closing process, a pressure increasing process, a mold closing process, a filling process, a pressure maintaining process, a cooling process, a pressure releasing process, a mold opening process, and an ejection process in injection molding under the control of the control device 700.

In the injection molding, the mold apparatus 800 operates the temperature adjustment mechanism 811 to adjust (heat) the temperature of the fixed mold 810 and the movable mold 820. For example, the temperature adjustment mechanism 811 supplies a temperature adjustment medium to the fixed mold 810 via a temperature adjustment medium supply pipe 812a, and discharges the temperature adjustment medium temperature-adjusted to the fixed mold 810 via a temperature adjustment medium discharge pipe 812 b. The temperature-controlled mold device 800 (fixed mold 810) or the pipe 812 through which the temperature-controlled medium flows heats the air around the mold device to room temperature or higher and convects the air.

The 4 connecting rods 140 extending at adjacent positions of the mold device 800 are affected by the heat. In particular, the heated air flows upward, so that the heated air is directed toward the connection rod 140 located above the temperature-adjusting medium supply pipe 812a among the 4 connection rods 140. For example, in a structure without the thermal restriction member 143, the influence of heat of the mold device 800 becomes uneven among the 4 connection bars 140. As a result, a difference occurs in axial force (elongation at the time of mold clamping) between the 4 tie bars 140.

The injection molding machine 10 according to the present embodiment includes the thermal regulating portions 142 in the 4 connecting rods 140 extending outside the fixed platen 110. The heat restricting portion 142 restricts the heat of the heated air in the mold device 800 and the pipe 812 from moving to the tie bar 140, and can reduce the heat input to the tie bar 140. Thus, the injection molding machine 10 can stabilize the axial force of the tie bar 140, and can favorably perform mold clamping or the like of the fixed mold 810 and the movable mold 820.

In particular, the heat restricting portions 142 are provided in the 4 tie bars 140, respectively, so that it is possible to easily cope with the direction of heat input of air that varies depending on the shape of the fixed mold 810, the movable mold 820, the arrangement of the piping 812, and the like. Further, each heat restricting portion 142 suppresses heat transfer inside the same, thereby reducing the difference in the amount of heat input transferred to each connecting rod 140. Therefore, the injection molding machine 10 can make the axial forces of the 4 tie bars 140 uniform with each other at the time of mold clamping of injection molding, thereby performing injection molding more stably.

Further, the injection molding machine 10 can simplify the attachment and detachment of the thermal restriction portion 142 of the connecting rod 140 by applying the thermal restriction member 143 provided in advance so as to match the outer peripheral surface of the connecting rod 140 as the thermal restriction portion 142. Therefore, even if the thermal regulating portion 142 is applied, the mold device 800 can be effectively attached and detached, and maintenance of the injection molding machine 10 can be effectively performed. The thermal limiter 142 may be fixed to the link 140 so as not to extend or retract.

Further, the heat restricting portion 142 is continuously provided in the entire axial direction of the connecting rod 140 from the fixed platen 110 to the movable platen 120, so that the influence of heat of the mold device 800 can be suppressed over a sufficient length in the axial direction. On the other hand, the connection rod 140 can be firmly fixed inside the fixed platen 110.

In addition, the heat limiting portion 142 disposed between the fixed mold 810 or the movable mold 820 and the connection lever 140 can stably limit the heat transfer of the fixed mold 810 or the movable mold 820 to the connection lever 140. Similarly, the heat restricting portion 142 disposed between the pipe 812 and the connection rod 140 can stably restrict the heat transfer from the pipe 812 to the connection rod 140.

The injection molding machine 10 according to the present embodiment is not limited to the above embodiment, and various modifications can be adopted. For example, in the above embodiment, the configuration in which the thermal restriction portions 142 are provided in all of the 4 connection rods 140 has been described. However, the heat restricting portion 142 may be provided to the connection rod 140 that is susceptible to heat, but may not be provided to the connection rod 140 that is less susceptible to heat. For example, in fig. 3 (a), the heat restricting portion 142 may be provided only in the upper left connecting rod 140.

Fig. 5 is a diagram schematically showing a thermal limiter according to a modification. As shown in fig. 5, the injection molding machine 10 may be configured such that a shielding member 145 is disposed as a heat restricting portion 142 between the mold device 800 and each of the tie bars 140. The shielding member 145 is formed in a plate shape, for example, and is fixed to the fixed platen 110. In fig. 5, the shielding member 145 is a circular arc plate, but the shape of the shielding member 145 is not limited, and may be a flat plate, for example. In this way, even if the shielding member 145 is disposed between the mold device 800 and the pipe 812 at a position separated from the outer peripheral surface of the connecting rod 140, the injection molding machine 10 can restrict the movement of the air heated by the mold device 800 to the connecting rod 140.

In all respects, the injection molding machine 10, the heat limiting member, and the heat input suppressing method according to the embodiment disclosed herein are illustrative, and not restrictive. The embodiments can be modified and improved in various ways without departing from the scope and gist of the embodiments. The matters described in the above-described embodiments can be combined with other configurations within a range not inconsistent with each other.

Claims (8)

1. An injection molding machine for opening and closing a fixed mold and a movable mold by moving a movable platen provided with the movable mold along a connecting rod with respect to a fixed platen provided with the fixed mold, the injection molding machine comprising:

and a heat limiting part for limiting the movement of the air heated to room temperature or above around the connecting rod to the connecting rod.

2. The injection molding machine according to claim 1, wherein,

the thermal limiter is a member that covers an outer peripheral surface of the connecting rod.

3. The injection molding machine according to claim 1 or 2, wherein,

the thermal limiting part is tightly attached to the outer peripheral surface of the connecting rod.

4. An injection molding machine according to any one of claims 1 to 3, wherein,

the thermal restriction portion is provided at a portion of the connection rod exposed from the fixed platen.

5. The injection molding machine according to any one of claims 1 to 4, wherein,

the thermal limiting part is arranged between the fixed die or the movable die and the connecting rod.

6. The injection molding machine according to any one of claims 1 to 5, wherein,

the thermal regulating portion is disposed between a pipe for supplying and discharging a temperature adjusting medium to and from the inside of the fixed mold or the movable mold and the tie bar.

7. A thermal restriction member is provided in an injection molding machine which opens and closes a fixed mold and a movable mold by moving a movable platen provided with the movable mold along a connecting rod with respect to a fixed platen provided with the fixed mold,

the heat restricting member restricts movement of air heated to room temperature or higher around the connection rod to the connection rod in a state of being attached to the connection rod.

8. In an injection molding machine in which a movable platen provided with a movable mold is moved along a connecting rod with respect to a fixed platen provided with a fixed mold to open and close the fixed mold and the movable mold, a heat input to the connecting rod is restricted,

limiting movement of air heated above room temperature around the connecting rod to the connecting rod.