CN110948805B - Injection molding machine - Google Patents

Abstract

The injection molding machine of the present invention comprises: a fixed platen, on which a fixed mold is mounted; a movable platen on which a movable mold is mounted; a rear platen disposed on the opposite side of the movable platen from the fixed platen, and coupled to the fixed platen via a coupling rod; and a support member that supports a vertical direction central portion of a lateral side surface of at least 1 platen selected from the fixed platen, the movable platen, and the rear platen when viewed in a mold opening and closing direction, the support member having a support column portion extending in a vertical direction and an intermediate portion connecting an upper end portion of the support column portion and the vertical direction central portion of the lateral side surface of the platen, the intermediate portion having a displacement portion that is displaced downward with respect to the support column portion by thermal expansion at a position lower than the upper end portion of the support column portion.

Description

Injection molding machine

Technical Field

The present application claims priority based on japanese patent application No. 2018-180329, applied on 26/9/2018. The entire contents of this Japanese application are incorporated by reference into this specification.

The present invention relates to an injection molding machine.

Background

The injection molding machine described in patent document 1 includes a fixed platen and a rear platen connected by a connecting rod on a table, and a movable platen that moves between these platens. The fixed platen, the movable platen, and the rear platen are supported symmetrically from both sides by support members at substantially the center height position of these platens in the vertical direction.

A fixed die is mounted on the fixed platen, and a movable die is mounted on the movable platen. A mold device is constituted by a fixed mold and a movable mold. On the other hand, a driving device is mounted on the rear platen. The driving device is a hydraulic or electric device that performs mold closing, and mold opening of the mold device by advancing and retreating the movable platen relative to the fixed platen.

The heat of the fixed mold is released to the work table via the fixed platen and the support member. The heat of the movable mold is released to the table through the movable platen and the support member. Similarly, heat of the driving device is released to the table through the rear platen and the supporting member. The table is also referred to as a mold clamping unit frame.

Patent document 1: japanese patent laid-open publication No. 2010-89295

Patent document 2: japanese laid-open patent publication No. 2009-101528

The support member supports a center portion in a vertical direction of a lateral side surface of the pressure receiving plate when viewed from a mold opening and closing direction. Since the vertical center portion of the lateral side surface of the platen serves as an outlet port for heat in the platen, the temperature distribution of the platen becomes vertically symmetrical, and the inclination of the platen can be suppressed.

The support member is a passage for transferring heat from the platen to the mold clamping unit frame, and therefore extends in the vertical direction by the heat from the platen. As a result, there is a problem that the vertical center position of the platen is displaced upward in the vertical direction with respect to the mold clamping unit frame.

The displacement of the vertical center position of the platen may cause positional deviation between the pin and the pin bush, or change in mold clamping force balance, or the like. The guide pin and the guide bush are used for alignment of the fixed mold and the movable mold.

In order to limit the elongation of the support member due to the temperature rise, patent document 1 proposes forming the support member from an iron-nickel alloy called invar. Invar has a problem of being expensive, although it can reduce the thermal expansion coefficient to about 1/10 compared to a general steel material.

In order to limit the extension of the support member due to the temperature rise, patent document 2 proposes controlling the temperature of the support member. Since a thermostat is required for controlling the temperature of the support member, there is a problem that the structure of the mold clamping device becomes complicated. Further, the control is complicated.

Disclosure of Invention

An aspect of the present invention provides a technique that can cancel out the extension of one portion of a support member due to a temperature increase and the extension of the other portion of the support member due to a temperature increase, and can regulate the displacement of the vertical center position of a platen.

An injection molding machine according to an aspect of the present invention includes:

a fixed platen, on which a fixed mold is mounted;

a movable platen on which a movable mold is mounted;

a rear platen disposed on the opposite side of the movable platen from the fixed platen, and coupled to the fixed platen via a coupling rod; and

a support member for supporting a central portion in a vertical direction of a lateral side surface of at least 1 platen selected from the fixed platen, the movable platen, and the rear platen when viewed from a mold opening/closing direction,

the support member has a column portion extending in the vertical direction and an intermediate portion connecting an upper end portion of the column portion and a vertical direction central portion of the lateral side surface of the platen,

the intermediate portion has a displacement portion that is displaced downward relative to the pillar portion by thermal expansion at a position below an upper end portion of the pillar portion.

Effects of the invention

According to one aspect of the present invention, the elongation of one portion of the support member due to a temperature increase and the elongation of the other portion of the support member due to a temperature increase can be cancelled out, and the displacement of the vertical center position of the platen can be restricted.

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 of mold clamping of the injection molding machine according to the embodiment.

Fig. 3 is a view of the fixed platen and the fixed platen support member according to the embodiment as viewed from the mold opening/closing direction.

Fig. 4 is a diagram showing an example of a relationship between the temperature distribution of the fixed platen and the fixed platen support member shown in fig. 3 and the shape of the fixed platen support member.

Fig. 5 is a view of the fixed platen and the fixed platen support member according to modification 1 as viewed from the mold opening/closing direction.

Fig. 6 is a diagram showing an analysis example of the relationship between the temperature distribution of the fixed platen and the fixed platen support member shown in fig. 5 and the shape of the fixed platen support member.

Fig. 7 is a view of the fixed platen and the fixed platen support member according to modification 2 as viewed from the mold opening/closing direction.

Fig. 8 is a diagram showing an analysis example of the relationship between the temperature distribution of the fixed platen and the fixed platen support member shown in fig. 7 and the shape of the fixed platen support member.

Fig. 9 is a view of the fixed platen and the fixed platen support member according to modification 3 as viewed from the mold opening/closing direction.

Fig. 10 is a view of the movable platen and the support member for the movable platen according to the embodiment as viewed from the mold opening and closing direction.

Fig. 11 is a view of the boss base and the boss base support member according to the embodiment as viewed from the mold opening/closing direction.

In the figure: 10-injection molding machine, 100-mold clamping device, 110-stationary platen, 120-movable platen, 130-journal seat (back platen), 510-support member for stationary platen, 511-pillar section, 512-middle section, 513-1 st horizontal section, 514-plumb section (displacement section), 515-2 nd horizontal section, 520-support member for movable platen, 521-pillar section, 522-middle section, 1 st horizontal section, 524-plumb section (displacement section), 525-2 nd horizontal section, 530-journal seat support member, 531-pillar section, 532-middle section, 533-1 st horizontal section, 534-plumb section (displacement section), 535-2 nd horizontal section, 540-temperature distribution adjusting section, 541-heat insulating layer, 542-heat transfer section, 543-relief section.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same or corresponding reference numerals, and the 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 of mold clamping of the injection molding machine according to the embodiment. In fig. 1 to 2, the X-axis direction, the Y-axis direction, and the Z-axis direction are perpendicular to each other. The X-axis direction and the Y-axis direction indicate the horizontal direction, and the Z-axis direction indicates the vertical direction. 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 Y-direction negative side is referred to as an operation side, and the Y-direction positive side is referred to as an opposite side to the operation side.

As shown in fig. 1 to 2, the injection molding machine 10 includes a mold clamping device 100, an ejector 200, an injection device 300, a moving device 400, a control device 700, and a frame 900. The frame 900 includes a mold clamping unit frame 910 and an injection unit frame 920. The mold clamping unit frame 910 and the injection unit frame 920 are installed on the floor surface 2 via horizontal adjustment legs 930. A control device 700 is disposed in the inner space of the injection device frame 920. Hereinafter, each constituent element of the injection molding machine 10 will be described.

(mold clamping device)

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

The mold clamping device 100 performs mold closing, pressure raising, mold clamping, pressure releasing, and mold opening of the mold device 800. The mold apparatus 800 includes a fixed 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, a movable platen 120, a boss 130, a tie bar 140, a toggle mechanism 150, a mold clamping motor 160, a motion conversion mechanism 170, and a mold thickness adjustment mechanism 180.

The stationary platen 110 is fixed to the mold clamping unit frame 910. A stationary mold 810 is attached to a surface of the stationary platen 110 facing the movable platen 120.

The movable platen 120 is disposed to be movable in the mold opening/closing direction with respect to the mold clamping unit frame 910. A guide 101 for guiding the movable platen 120 is laid on the mold clamping unit frame 910. A movable mold 820 is attached to a surface of the movable platen 120 facing the fixed platen 110. The mold closing, pressure increasing, mold closing, pressure releasing, and mold opening of the mold apparatus 800 are performed by advancing and retracting the movable platen 120 relative to the fixed platen 110.

The joint holder 130 is disposed at an interval from the fixed platen 110, and is movably mounted on the mold clamping unit frame 910 in the mold opening/closing direction. The joint holder 130 may be disposed to be movable along a guide laid on the mold clamping unit frame 910. The guide of the joint seat 130 may be shared with the guide 101 of the movable platen 120.

In the present embodiment, the fixed platen 110 is fixed to the mold clamping unit frame 910, and the joint holder 130 is disposed to be movable in the mold opening and closing direction with respect to the mold clamping unit frame 910, but the joint holder 130 may be fixed to the mold clamping unit frame 910, and the fixed platen 110 may be disposed to be movable in the mold opening and closing direction with respect to the mold clamping unit frame 910.

The connecting rod 140 connects the stationary platen 110 and the boss base 130 with a space L therebetween in the mold opening and closing direction. Multiple (e.g., 4) connecting rods 140 may be used. The plurality of tie bars 140 are arranged parallel to the mold opening and closing direction and extend according to the mold clamping force. A tie bar strain detector 141 that detects strain of the tie bar 140 may be provided on at least 1 tie bar 140. The tie-bar 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 mold clamping force and the like.

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

The toggle mechanism 150 is disposed between the movable platen 120 and the boss 130, and moves the movable platen 120 relative to the boss 130 in the mold opening and closing direction. The toggle mechanism 150 is constituted by a cross 151, a pair of links, and the like. The pair of link groups includes a 1 st link 152 and a 2 nd link 153 connected to each other by a pin or the like so as to be bendable and extendable. The 1 st link 152 is attached to the movable platen 120 by a pin or the like so as to be freely swingable. The 2 nd link 153 is attached to the joint holder 130 by a pin or the like so as to be freely swingable. The 2 nd link 153 is mounted to the crosshead 151 via the 3 rd link 154. When the crosshead 151 is advanced and retreated with respect to the joint holder 130, the 1 st link 152 and the 2 nd link 153 are flexed and extended, and the movable platen 120 is advanced and retreated with respect to the joint holder 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, and one end of the 3 rd link 154 may be coupled to the node of the 1 st link 152 and the 2 nd link 153.

The mold clamping motor 160 is attached to the journal bracket 130 to operate the toggle mechanism 150. The mold clamping motor 160 advances and retracts the crosshead 151 with respect to the joint base 130, thereby flexing and extending the 1 st link 152 and the 2 nd link 153 and advancing and retracting the movable platen 120 with respect to the joint base 130. The mold clamping motor 160 is directly coupled to the motion conversion mechanism 170, but may be coupled to the motion conversion mechanism 170 via a belt, a wheel, or the like.

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 threaded shaft and a nut that is screwed with the threaded shaft. Balls or rollers may be interposed between the threaded shaft and the nut.

The mold clamping apparatus 100 performs a mold closing process, a pressure raising 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 mold clamping motor 160 is driven to advance the crosshead 151 to the mold closing end position at the set movement speed, thereby advancing the movable platen 120 and bringing the movable mold 820 into contact with the fixed mold 810. The position or the moving speed of the crosshead 151 is detected by, for example, a mold clamping motor encoder 161 or the like. 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.

The crosshead position detector that detects the position of the crosshead 151 and the crosshead travel speed detector that detects the travel speed of the crosshead 151 are not limited to the clamp motor encoder 161, and a general detector can be used. The movable platen position detector that detects the position of the movable platen 120 and the movable platen moving speed detector that detects the moving speed of the movable platen 120 are not limited to the clamp motor encoder 161, and a general detector can be used.

In the pressure raising 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.

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 raising step is maintained. In the mold clamping process, 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 the cavity spaces 801 may be 1 or more. When the cavity space is plural, plural molded articles can be obtained at the same time. An insert may be disposed in a portion of the cavity space 801 and a molding material may be filled in another portion of the cavity space 801. A molded article in which the insert and the molding material are integrated can be obtained.

In the pressure releasing step, the clamping motor 160 is driven to retract the crosshead 151 from the clamping position to the mold opening start position, thereby retracting the movable platen 120 and reducing the clamping force. The mold opening start position and the mold closing end position may be the same position.

In the mold opening process, the mold closing motor 160 is driven to retract the crosshead 151 from the mold opening start position to the mold opening end position at a set moving speed, thereby retracting the movable platen 120 and separating the movable mold 820 from the fixed mold 810. After that, the ejector 200 ejects the molded product from the movable mold 820.

The setting conditions in the mold closing step, the pressure raising step, and the mold clamping step are set collectively as a series of setting conditions. For example, the moving speed or position of the crosshead 151 (including the mold closing start position, the moving speed switching position, the mold closing end position, and the mold clamping position) in the mold closing step and the pressure raising step, and the mold clamping force are 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 this order from the rear side toward the front side, and indicate the start point or the end point of the section in which the moving speed is set. The moving speed is set for each section. The moving speed switching position may be 1 or plural. The moving speed switching position may not be set. Only either one of the mold clamping position and the mold clamping force may be set.

The setting conditions in the decompression step and the mold opening step are also set in the same manner. For example, the moving speed or position of the crosshead 151 (mold opening start position, moving speed switching position, and mold opening end position) in the decompression step and the mold opening step is 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 order from the front side to the rear side, and indicate the start point or the end point of the section in which the moving speed is set. The moving speed is set for each section. The moving speed switching position 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.

Instead of the moving speed or position of the crosshead 151, the moving speed or position of the movable platen 120 may be set. Further, the mold clamping force may be set instead of the position of the crosshead (for example, the mold clamping position) or the position of the movable platen.

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

When the thickness of the mold apparatus 800 changes due to replacement of the mold apparatus 800, temperature change of the mold apparatus 800, or the like, the mold thickness is adjusted so that a predetermined mold clamping force is obtained at the time of mold clamping. In the mold thickness adjustment, for example, the interval L between the fixed platen 110 and the boss 130 is adjusted so that the link angle θ of the toggle mechanism 150 becomes a predetermined angle at the time when the movable mold 820 contacts the mold in contact with the fixed mold 810.

The mold clamping device 100 includes a mold thickness adjusting mechanism 180. The die thickness adjusting mechanism 180 adjusts the die thickness by adjusting the interval L between the fixed platen 110 and the boss base 130. 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 threaded shaft 181 formed at the rear end of the tie rod 140, a nut 182 rotatably held in the boss 130 so as not to advance and retreat, and a die thickness adjusting motor 183 for rotating the nut 182 screwed with the threaded shaft 181.

A threaded shaft 181 and a nut 182 are provided for each connecting rod 140. The rotational driving force of the die thickness adjusting motor 183 can be transmitted to the plurality of nuts 182 via the rotational driving force transmitting portion 185. The plurality of nuts 182 can be rotated in synchronization. Further, the plurality of nuts 182 can be independently rotated by changing the transmission path of the rotational driving force transmission portion 185.

The rotational driving force transmission portion 185 is formed of, for example, a gear. At this time, a driven gear is formed on the outer periphery of each nut 182, a drive gear is attached to the output shaft of the die thickness adjusting motor 183, and an intermediate gear that meshes with the plurality of driven gears and the drive gear is rotatably held in the central portion of the journal holder 130. The rotational driving force transmission portion 185 may be formed of a belt, a wheel, or the like instead of a gear.

The operation of the die thickness adjusting mechanism 180 is controlled by the control device 700. The control device 700 drives the movable die thickness adjustment motor 183 to rotate the nut 182. As a result, the position of the boss 130 with respect to the connecting rod 140 is adjusted, and the interval L between the fixed platen 110 and the boss 130 is adjusted. Further, a plurality of die thickness adjusting mechanisms may be combined for use.

The interval L is detected by the die thickness adjustment motor encoder 184. The mold thickness adjusting motor encoder 184 detects the rotation amount or the rotation direction of the mold thickness adjusting 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 or control the position or spacing L of the journal seat 130. The joint seat position detector for detecting the position of the joint seat 130 and the interval detector for detecting the interval L are not limited to the die thickness adjustment motor encoder 184, and a general detector can be used.

The mold clamping apparatus 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.

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

(Ejection device)

In the description of the ejector 200, similarly to the description of the mold clamping apparatus 100, the moving direction of the movable platen 120 (for example, the positive X-axis direction) when the mold is closed is set to the front side, and the moving direction of the movable platen 120 (for example, the negative X-axis direction) when the mold is opened is set to the rear side.

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 for ejecting a molded product from the mold apparatus 800, and a drive mechanism 220 for moving the ejector rod 210 in the X-axis direction.

The ejector rod 210 is disposed to be movable forward and backward with respect to the through hole of the movable platen 120. The distal end of the ejector rod 210 contacts a movable member 830 disposed in the movable mold 820 so as to be movable forward and backward. The tip end of the ejector rod 210 may or may not be coupled to the movable member 830.

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

The ejection device 200 performs the ejection process under the control of the control device 700. In the ejection step, the ejector rod 210 is moved forward from the standby position to the ejection position at a set moving speed, and the movable member 830 is moved forward to eject the molded product. Thereafter, the ejector motor is driven to retract the ejector rod 210 at a set moving speed, and the movable member 830 is retracted to the original standby position.

The position or moving speed of the ejector rod 210 is detected, for example, using an ejector motor encoder. The ejection motor encoder detects the rotation of the ejection motor, and transmits a signal indicating the detection result to the control device 700. The ejector rod position detector for detecting the position of the ejector rod 210 and the ejector rod movement speed detector for detecting the movement speed of the ejector rod 210 are not limited to the ejector motor encoder, and a general detector can be used.

(injection device)

Unlike the description of the mold clamping apparatus 100 and the description of the ejector 200, in the description of the injection apparatus 300, the moving direction of the screw 330 during filling (for example, the X-axis negative direction) is taken as the front side, and the moving direction of the screw 330 during metering (for example, the X-axis positive direction) is taken as the rear side.

The injection device 300 is provided on the slide base 301, and the slide base 301 is disposed to be movable forward and backward with respect to the injection device frame 920. The injection device 300 is arranged to be movable forward and backward with respect to 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 the molding material. The injection device 300 includes, for example, a cylinder 310, a nozzle 320, a screw 330, a metering motor 340, an injection motor 350, a pressure detector 360, and the like.

The cylinder 310 heats the molding material supplied from the supply port 311 to the inside. The molding material includes, for example, resin or the like. The molding material is, for example, formed into a granular shape and supplied to the supply port 311 in a solid state. 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 heater 313 such as a band heater and a 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 in an axial direction (e.g., X-axis direction) of the cylinder 310. Heaters 313 and temperature detectors 314 are provided in a plurality of regions, respectively. Set temperatures are set in the plurality of regions, respectively, and the control device 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes the set temperature.

The nozzle 320 is provided at the front end of the cylinder 310 and is pressed against the die apparatus 800. A heater 313 and a temperature detector 314 are provided on the outer periphery of the nozzle 320. The control device 700 controls the heater 313 so that the temperature detected by the nozzle 320 becomes the set temperature.

The screw 330 is rotatably disposed in the cylinder 310 so as to be able to advance and retreat. When the screw 330 is rotated, the molding material is fed forward along the spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 while being fed forward. The screw 330 moves backward as the liquid molding material is sent to the front of the screw 330 and accumulated in the front of the cylinder 310. Thereafter, 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 apparatus 800.

A check ring 331 attached to a front portion of the screw 330 to be movable forward and backward serves as a check valve for preventing the molding material from flowing backward from the front of the screw 330 when the screw 330 is pressed 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 relative to the screw 330 until it reaches a closed position (see fig. 2) where the flow path of the molding material is blocked. This prevents backward flow of the molding material accumulated in front of the screw 330.

On the other hand, when the screw 330 is rotated, the check ring 331 is pushed forward by the pressure of the molding material fed forward along the spiral groove of the screw 330, and moves forward with respect to the screw 330 to the open position (see fig. 1) where the flow path of the molding material is opened. Thereby, the molding material is sent to the front of the screw 330.

The check ring 331 may be any one of a co-rotating type that rotates with the screw 330 and a non-co-rotating type that does not rotate with the screw 330.

The injection device 300 may have a drive source for moving the check ring 331 forward and backward between the open position and the closed position with respect to the screw 330.

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.

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

The pressure detector 360 detects the pressure transmitted between the injection motor 350 and the screw 330. The pressure detector 360 is provided in a pressure transmission path between the injection motor 350 and the screw 330, and detects a pressure acting on the pressure detector 360.

The pressure detector 360 transmits a signal indicating the detection result to the control device 700. The detection result of the pressure detector 360 is used to control or monitor the pressure applied to the screw 330 by the molding material, the back pressure applied to the screw 330, the pressure applied to the molding material by the screw 330, and the like.

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 process and the pressure holding process are also collectively referred to as an injection process.

In the metering step, the metering motor 340 is driven to rotate the screw 330 at a predetermined rotation speed, and the molding material is fed forward along the spiral groove of the screw 330. With this, the molding material gradually melts. The screw 330 moves backward as the liquid molding material is sent to the front of the screw 330 and accumulated in the front of the cylinder 310. The rotational speed of the screw 330 is detected, for example, by the 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 general detector can be used.

In the metering step, the injection motor 350 may be driven to apply a set back pressure to the screw 330 in order to restrict rapid retraction of the screw 330. The back pressure to the screw 330 is detected, for example, by a pressure detector 360. The pressure detector 360 transmits a signal indicating the detection result to the control device 700. When the screw 330 is retracted to the metering completion position and a predetermined amount of molding material is accumulated in front of the screw 330, the metering process is completed.

The position and the rotation speed of the screw 330 in the metering step are set 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 or the end point of the section in which the rotation speed is set. The rotation speed is set for each interval. The number of the rotational speed switching positions may be 1 or plural. The rotational speed switching position may not be provided. Further, the 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 liquid molding material accumulated in front of the screw 330 is filled into the cavity space 801 in the mold apparatus 800. The position or moving speed of the screw 330 is detected, for example, by 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 to the control device 700. When the position of the screw 330 reaches the set position, switching from the filling step to the holding pressure step (so-called V/P switching) is performed. The position where the V/P switching is performed is also referred to as a V/P switching position. The set moving speed of the screw 330 can be changed according to the position, time, and the like of the screw 330.

The position and the moving speed of the screw 330 in the filling process are set as a series of setting conditions. For example, a filling start position (also referred to as an "injection start position"), a movement speed switching position, and a V/P switching position are set. These positions are arranged in order from the rear side toward the front side, and indicate the start point or the end point of the section in which the moving speed is set. The moving speed is set for each section. The moving speed switching position 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 interval of the movement speed of the screw 330. The pressure of the screw 330 is detected by a pressure detector 360. When the detection value of the pressure detector 360 is equal to or lower than the set pressure, the screw 330 moves forward at the set moving speed. On the other hand, when the detection value of the pressure detector 360 exceeds the set pressure, the screw 330 is advanced at a moving speed slower than the set moving speed so that the detection value of the pressure detector 360 becomes equal to or lower than the set pressure for the purpose of protecting the mold.

In the filling step, after the position of the screw 330 reaches the V/P switching position, the screw 330 may be temporarily stopped at the V/P switching position, and then the V/P switching may be performed. Instead of stopping the screw 330, a slight speed advance or a slight speed retreat of the screw 330 may be performed 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 general detector can be used.

In the pressure maintaining step, the injection motor 350 is driven to push the screw 330 forward, the pressure of the molding material at the tip end of the screw 330 (hereinafter, also referred to as "holding pressure") is maintained at a set pressure, and the molding material remaining in the cylinder 310 is pushed toward the mold apparatus 800. The molding material that is insufficient due to cooling shrinkage in the mold apparatus 800 can be compensated. The holding pressure is detected, for example, by the pressure detector 360. The pressure detector 360 transmits a signal indicating the detection result to the control device 700. The set value of the holding pressure may be changed according to the time elapsed from the start of the pressure holding step. The holding pressure and the holding time for holding the holding pressure in the holding pressure step may be set in plural numbers, respectively, or may be set collectively as a series of setting conditions.

In the pressure retaining step, the molding material in the cavity space 801 in the mold apparatus 800 is gradually cooled, and the entrance of the cavity space 801 is closed by the solidified molding material at the end of the pressure retaining step. This state is called gate closing, and prevents the backflow of the molding material from the cavity space 801. And starting a cooling process after the pressure maintaining process. In the cooling step, the molding material in the cavity space 801 is solidified. The metering step can be performed in the cooling step for the purpose of shortening the molding cycle time.

The injection device 300 of the present embodiment is of a coaxial screw type, but may be of a screw preplasticizing type or the like. The injection device of the screw preplasticizing 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 disposed so as to be rotatable and incapable of advancing and retreating, or the screw is disposed so as to be rotatable and capable of advancing and retreating. On the other hand, the plunger is disposed in the injection cylinder so as to be movable forward and backward.

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

(moving device)

In the explanation of the moving device 400, similarly to the explanation of the injection device 300, the moving direction of the screw 330 (for example, the X-axis negative direction) at the time of filling is taken as the front, and the moving direction of the screw 330 (for example, the X-axis positive direction) at the time of metering is taken as the rear.

The moving device 400 advances and retreats the injection device 300 with respect to the mold device 800. Then, the moving device 400 presses the nozzle 320 against the mold device 800, and generates 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 that is rotatable in both directions, and generates hydraulic pressure by switching the rotation direction of the motor 420, sucking in hydraulic fluid (for example, oil) from one of the 1 st port 411 and the 2 nd port 412 and discharging the hydraulic fluid from the other. The hydraulic pump 410 can also suck the hydraulic fluid from the tank and discharge the hydraulic fluid from either the 1 st port 411 or the 2 nd port 412.

The motor 420 operates the hydraulic pump 410. The motor 420 drives the hydraulic pump 410 in a rotational direction and torque according to a control signal from the control device 700. The motor 420 may be an electric motor or an electric servomotor.

The hydraulic cylinder 430 includes a cylinder main 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 as a 1 st chamber and a rear chamber 436 as a 2 nd chamber. The piston rod 433 is fixed to the stationary 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 through the 1 st channel 401, and the injection device 300 is pushed forward. The injection device 300 is advanced and the nozzle 320 is crimped to the stationary mold 810. Front chamber 435 functions as a pressure chamber for generating a nozzle contact pressure of nozzle 320 by the pressure of the hydraulic fluid supplied from 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 through the 2 nd flow path 402, and 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 thereto. For example, 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 instead of the hydraulic cylinder 430.

(control device)

As shown in fig. 1 to 2, the control device 700 is formed of a computer, for example, and includes a CPU (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 raising 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 repeatedly manufacture a molded product. A series of operations for obtaining a molded product, for example, operations from the start of a metering process to the start of the next metering process are also referred to as "injection" or "molding cycle". Also, the time required for 1 injection 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 raising 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 order in which the respective steps start. The filling step, the pressure holding step, and the cooling step are performed between the mold clamping steps. The start of the mold clamping process may coincide with the start of the filling process. The end of the decompression process may coincide with the start of the mold opening process.

In addition, a plurality of steps can be performed simultaneously with the aim 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 between the mold clamping steps. In this case, the mold closing process may be performed at the beginning of the molding cycle. Also, the filling process may be started in the mold closing process. The ejection process may be started in the mold opening process. When an opening/closing valve for opening/closing the flow path of the nozzle 320 is provided, the mold opening step may be started in the metering step. This is because, even if the mold opening step is started in the metering step, the molding material does not leak from the nozzle 320 as long as the flow path of the nozzle 320 is closed by the opening and closing valve.

The one-shot molding cycle may include steps other than a metering step, a mold closing step, a pressure raising 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.

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

After the metering step is completed and before the filling step is started, a post-metering back-drawing step may be performed in which the screw 330 is retracted to a preset filling start position (also referred to as an "injection start position"). The pressure of the molding material accumulated in front of the screw 330 before the start of the filling process can be reduced, and the molding material can be prevented from leaking from the nozzle 320 before the start of the filling process.

The control device 700 is connected to the operation device 750 or the display device 760. The operation device 750 receives an input operation by a user, and outputs a signal corresponding to the input operation to the control device 700. Display device 760 displays a display screen corresponding to an input operation in operation device 750, under the control of control device 700.

The display screen is used for setting the injection molding machine 10 and the like. A plurality of display screens are prepared, and display is switched or overlapped. The user operates operation device 750 while viewing the display screen displayed on display device 760, and performs setting (including input of set values) of injection molding machine 10.

The operation device 750 and the display device 760 may be formed of a touch panel, for example, and integrated together. Further, although the operation device 750 and the display device 760 of the present embodiment are integrated, they may be provided separately. Moreover, a plurality of the operation devices 750 may be provided. The operation device 750 and the display device 760 are disposed on the Y-axis direction negative side of the mold clamping device 100 (more specifically, the fixed platen 110). The Y-direction negative side is referred to as an operation side, and the Y-direction positive side is referred to as an opposite side to the operation side.

(stationary platen and supporting Member for stationary platen)

Fig. 3 is a view of the fixed platen and the fixed platen support member according to the embodiment as viewed from the mold opening/closing direction. The fixed platen 110 and the fixed platen support member 510 are formed in line symmetry with the width direction center line L1 of the fixed platen 110 as the center of symmetry. Therefore, in fig. 3, the right portion (operation side portion) in fig. 3 is illustrated with reference to the width direction center line L1 of the fixed platen 110, and the left portion (reverse operation side portion) in fig. 3 is omitted.

A virtual line passing through the center position of the fixed platen 110 in the width direction (Y-axis direction) and extending in the vertical direction (Z-axis direction) is referred to as a width-direction center line L1 of the fixed platen 110. An imaginary line passing through the center position of the fixed platen 110 in the vertical direction and extending in the width direction is referred to as a vertical center line L2 of the fixed platen 110. The mold opening and closing direction is the X-axis direction. The mold opening and closing direction is also referred to as a front-rear direction. The positive side in the X-axis direction is the front, and the negative side in the X-axis direction is the rear. The X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.

The fixed platen 110 includes a fixed platen main body 111 to which a fixed mold 810 (see fig. 1 and the like) is attached, and an edge portion 116 formed at a vertical center portion of a lateral side surface 112 of the fixed platen main body 111.

The fixed platen main body portion 111 has a rectangular outer shape when viewed from the mold opening and closing direction. Tie bar mounting holes 113 penetrating the stationary platen main body 111 in the front-rear direction are formed at four corners of the rear end surface of the stationary platen main body 111. The front end of the link 140 is inserted into the link mounting hole 113. A nozzle insertion hole 114 penetrating the stationary platen body 111 in the front-rear direction is formed in the center of the rear end surface of the stationary platen body 111. The nozzle 320 of the injection apparatus 300 is inserted into the nozzle insertion hole 114, and the nozzle 320 contacts the stationary mold 810.

The edge 116 is formed at the vertical center of the lateral side 112 of the fixed platen body 111. The lower end surface of the edge portion 116 is, for example, a horizontal surface, and is placed on the horizontal surface of the support member for a fixed platen 510. The lower end surface of the edge portion 116 is disposed at the same height as the vertical center line L2 of the fixed platen 110, for example.

The fixed platen support member 510 supports the vertical center portion of the lateral side 112 of the fixed platen 110 when viewed from the mold opening and closing direction. The fixed platen support member 510 supports the fixed platen 110 in a floating manner from the mold clamping device frame 910, and therefore the lower end surface of the fixed platen 110 does not serve as an outflow port for heat from the fixed platen 110. Since the vertical center portion of the lateral side 112 of the fixed platen 110 serves as an outlet port for heat in the fixed platen 110, the temperature distribution of the fixed platen 110 becomes vertically symmetrical, and the inclination of the fixed platen 110 can be suppressed.

The fixed platen support member 510 includes, for example, a support column portion 511 extending in the vertical direction and an intermediate portion 512 connecting an upper end portion of the support column portion 511 and a vertical direction center portion of the lateral side surface 112 of the fixed platen 110. The intermediate portion 512 has a displacement portion that is displaced downward with respect to the column portion 511 by thermal expansion at a position below the upper end portion of the column portion 511. The displacement portion is, for example, a hanging portion 514 described later.

The support column portion 511 has a lower end surface at a position lower than the lower end surface of the fixed platen 110 in order to support the fixed platen 110 in a floating manner from the mold clamping device frame 910. The lower end surface of the pillar portion 511 is fixed to the mold clamping device frame 910 by bolts or the like.

The support column portion 511 has an upper end surface at a position above the vertical center line L2 of the fixed platen 110 in order to increase the vertical dimension of the vertical portion 514. The upper end surface of the pillar portion 511 is disposed above the lower end surface of the edge portion 116.

The upper end surface of the support column portion 511 may be disposed below the lower end surface of the edge portion 116. At this time, the intermediate portion 512 may have a vertical portion 514 in the middle from the upper end surface of the pillar portion 511 to the lower end surface of the edge portion 116.

The intermediate portion 512 extends from the upper end surface of the pillar portion 511 to the lower end surface of the edge portion 116. The intermediate portion 512 is integrated with the pillar portion 511 on the upper end surface of the pillar portion 511. The intermediate portion 512 is integrated with the edge portion 116 at the lower end surface of the edge portion 116.

For example, the intermediate portion 512 includes a 1 st horizontal portion 513 extending horizontally from the upper end portion of the support column portion 511 toward the lateral side surface 112 of the fixed platen 110, and a vertical portion 514 extending downward from the front end portion of the 1 st horizontal portion 513. The intermediate portion 512 has a 2 nd horizontal portion 515 extending horizontally from the lower end portion of the vertical portion 514 toward the lateral side surface 112 of the fixed platen 110.

The 1 st horizontal portion 513 is placed on the upper end surface of the pillar portion 511, and is fastened by the pillar portion 511 and the bolt 518. For example, a straight hole penetrating the 1 st horizontal portion 513 in the vertical direction is formed in the 1 st horizontal portion 513, and a bolt 518 is inserted into the straight hole. On the other hand, a bolt hole is formed in the upper end surface of the column portion 511, and a bolt 518 is screwed into the bolt hole.

The hanging portion 514 is disposed between the column portion 511 and the edge portion 116 of the fixed platen 110. The depending portion 514 may form a gap with the edge portion 116. Since the vertical portion 514 is not restricted in the lateral direction by the edge portion 116, it can be vertically extended by a temperature increase. Since the extension of the suspended portion 514 is not hindered by the edge portion 116, the extension margin of the suspended portion 514 is large.

In addition, the hanging portion 514 may be in sliding contact with the edge portion 116. At this time, the vertical portion 514 is not restricted in the lateral direction by the edge portion 116, and therefore can be extended straight in the vertical direction by a temperature increase. However, even if the vertical portion 514 is laterally restricted by the edge portion 116, the vertical portion 514 can be extended in the vertical direction by a temperature increase.

The hanging portion 514 may contact the pillar portion 511. The vertical portion 514 has a sliding surface 516 in sliding contact with the column portion 511, and the column portion 511 has a sliding surface 517 in sliding contact with the vertical portion 514. The sliding surface 516 of the hanging portion 514 and the sliding surface 517 of the pillar portion 511 are flat surfaces perpendicular to the width direction of the fixed platen 110, for example. The sliding surfaces 516 and 517 may be curved surfaces as long as they can be displaced relative to each other in the vertical direction.

The vertical portion 514 and the support portion 511 may not be in contact with each other, and a gap may be formed between the vertical portion 514 and the support portion 511. When the gap is formed, the vertical portion 514 and the support portion 511 can be displaced relative to each other in the vertical direction. Further, when the gap is formed, since there is no frictional resistance, displacement is easily generated.

The edge portion 116 of the fixed platen 110 is placed on the 2 nd horizontal portion 515, and is fastened by the edge portion 116 and the bolt 519. A straight hole penetrating the 2 nd horizontal portion 515 in the vertical direction is formed in the 2 nd horizontal portion 515, and a bolt 519 is inserted through the straight hole. On the other hand, a bolt hole is formed in the lower end surface of the edge portion 116, and a bolt 519 is screwed into the bolt hole.

In addition, the arrangement of the straight holes and bolt holes may be reversed. Specifically, a straight hole that penetrates the edge portion 116 in the vertical direction may be formed in the edge portion 116 of the fixed platen 110, and the bolt 519 may be inserted into the straight hole. A bolt hole may be formed in the upper end surface of the 2 nd horizontal portion 515, and a bolt 519 may be screwed into the bolt hole.

In the present embodiment, the fixed platen 110 and the fixed platen support member 510 are cast separately and fastened by the bolts 519, but may be cast integrally. In the present embodiment, the column portion 511 of the stationary platen support member 510 and the intermediate portion 512 of the stationary platen support member 510 are cast separately and fastened by the bolts 518, but may be cast integrally.

The heat of the fixed mold 810 is transmitted to the mold clamping unit frame 910 via the fixed platen 110, the intermediate portion 512 of the fixed platen support member 510, and the pillar portion 511 of the fixed platen support member 510. The stationary mold 810 is a heat source.

The column portion 511 is heated by heat from the fixed mold 810, and therefore extends in the vertical direction by a temperature increase. At this time, the lower end surface of the column portion 511 is not displaced, and the upper end surface of the column portion 511 is displaced upward. The lower end surface of the pillar portion 511 is not displaced because the lower end surface of the pillar portion 511 is fixed to the mold clamping device frame 910 by bolts or the like.

The vertical portion 514 of the intermediate portion 512 is also heated by heat from the fixed mold 810, similarly to the pillar portion 511, and therefore also extends in the vertical direction by a temperature increase. Since the vertical portion 514 is closer to the heat source than the column portion 511, the temperature of the vertical portion 514 becomes higher than the temperature of the column portion 511. Therefore, the elongation per unit length of the hanging portion 514 is larger than the elongation per unit length of the column portion 511. Therefore, the vertical dimension of the sliding surface 516 of the vertical portion 514 is larger than the vertical dimension of the sliding surface 517 of the pillar portion 511.

At this time, the upper end edge 516a of the sliding surface 516 of the vertical portion 514 does not vertically displace with respect to the upper end edge 517a of the sliding surface 517 of the pillar portion 511. This is because the lower end surface of the 1 st horizontal portion 513 is integrally bonded to the upper end surface of the support portion 511. On the other hand, the lower end edge 516b of the sliding surface 516 of the vertical portion 514 is displaced downward in the vertical direction with respect to the lower end edge 517b of the sliding surface 517 of the pillar portion 511.

The extension of the column portion 511 due to the temperature increase and the extension of the vertical portion 514 due to the temperature increase can be cancelled out, and the displacement of the vertical center position of the fixed platen 110 can be restricted. As a result, the positional deviation between the leader pin and the leader pin bush and the change in the balance of the mold clamping force can be restricted. The guide pins and the guide bush are used for positioning the fixed mold 810 and the movable mold 820. For example, a guide pin is formed in the fixed mold 810, and a guide bush is formed in the movable mold 820. Alternatively, a guide pin bush is formed in the fixed mold 810 and a guide pin is formed in the movable mold 820. In any case, the guide pin is disposed inside the guide bush at the end of mold closing, and the guide pin is disposed outside the guide bush at the end of mold opening.

As described above, the heat of the fixed mold 810 is transmitted to the pillar portion 511 through the intermediate portion 512. The intermediate portion 512 is closer to the heat source than the pillar portion 511. Therefore, the temperature of the intermediate portion 512 is higher than that of the pillar portion 511. Therefore, the displacement of the intermediate portion 512 is larger than that of the pillar portion 511. Therefore, a part of the extension of the column part 511 due to the temperature increase and the extension of the intermediate part 512 due to the temperature increase can be cancelled out. Therefore, the displacement of the vertical center position of the fixed platen 110 due to the displacement of the support column portion 511 can be restricted.

According to the present embodiment, in order to limit the displacement of the vertical center position of the fixed platen 110, the extension of one portion of the fixed platen support member 510 due to the temperature increase and the extension of the other portion of the fixed platen support member 510 due to the temperature increase are offset from each other. Therefore, since expensive special alloy such as invar alloy is not used, the material cost of the support member 510 for the stationary platen can be reduced. Further, since a thermostat for adjusting the temperature of the stationary platen support member 510 is not required, the structure of the mold clamping device 100 is simplified. Further, since temperature control is not necessary, the processing load of the control device 700 is small.

The technique of the present invention can be used in combination with at least 1 technique out of (1) a technique using an expensive special alloy such as invar alloy and (2) a technique using a thermostat. This is effective in further restricting the displacement of the vertical center position of the fixed platen 110.

The intermediate portion 512 may be formed of a material having a higher linear expansion coefficient than the pillar portion 511. When displacements of the vertical portion 514 of the intermediate portion 512 and the support column portion 511 are obtained to the same extent, the vertical portion 514 having a short vertical dimension can be used, and the support column portion 511 having a short vertical dimension can also be used. Therefore, the material cost of the support member for a stationary platen 510 can be reduced. On the other hand, if a material having a large linear expansion coefficient is selected as the material of the vertical portion 514 without changing the vertical dimension of the vertical portion 514, the degree of displacement can be increased, and the displacement of the vertical position of the fixed platen 110 can be further restricted. The material of the intermediate portion 512 and the material of the column portion 511 are selected from, for example, common steel materials.

Fig. 4 is a diagram showing an analysis example of the relationship between the temperature distribution of the fixed platen and the fixed platen support member shown in fig. 3 and the shape of the fixed platen support member. As an analysis model of the fixed platen, a model without the tie bar mounting hole 113 and the nozzle insertion hole 114 is used for easy analysis. In fig. 4, the deformation of the support member 510 for a fixed platen due to the temperature distribution is exaggerated.

The hot inflow ports from the intermediate portion 512 of the column portion 511 are 2 locations, namely, an upper end surface in contact with the 1 st horizontal portion 513 of the intermediate portion 512 and a sliding surface 517 in contact with the vertical portion 514 of the intermediate portion 512. The heat of the intermediate portion 512 flows into the pillar portion 511 from 2 locations, i.e., the upper end surface of the pillar portion 511 and the sliding surface 517 of the pillar portion 511. Therefore, the isotherm TL at the upper end of the column portion 511 is inclined. The isotherm TL is a virtual line.

As shown in fig. 4, the isotherm TL at the upper end of the strut part 511 is inclined as follows: the sliding surface 517 of the pillar portion 511 is displaced upward in the vertical direction (positive side in the Z-axis direction) as it is separated from the width direction (Y-axis direction). This is because the heat absorption amount from the sliding surface 517 decreases as the distance from the sliding surface 517 in the width direction increases.

Since the isotherm TL of the upper end portion of the column portion 511 is inclined, the upper end portion of the column portion 511 bends and deforms in accordance with the temperature distribution of the upper end portion of the column portion 511, and the upper end surface of the column portion 511 is inclined. The upper end surface of the support column portion 511 is inclined upward as it approaches the lateral side surface 112 of the fixed platen 110. Due to this inclination, the edge portion 116 of the fixed platen 110 is slightly raised, and the vertical center position of the fixed platen 110 is displaced upward.

Therefore, the fixed platen support member 510 according to modification 1 described below includes a temperature distribution adjusting unit 540 (see fig. 5) for making the slope of the isotherm TL at the upper end of the support column portion 511 closer to a horizontal level in order to further restrict upward displacement of the vertical center position of the fixed platen 110.

Fig. 5 is a view of the fixed platen and the fixed platen support member according to modification 1 as viewed from the mold opening/closing direction. Fig. 6 is a diagram showing an analysis example of the relationship between the temperature distribution of the fixed platen and the fixed platen support member shown in fig. 5 and the shape of the fixed platen support member.

The temperature distribution adjusting portion 540 of the present modification includes a heat insulating layer 541 that restricts heat transfer from the vertical portion 514 to the pillar portion 511 between the vertical portion 514 of the intermediate portion 512 and the pillar portion 511. A gap is formed between the vertical portion 514 and the pillar portion 511 for the purpose of disposing the heat insulating layer 541. The heat insulating layer 541 is formed of a material having lower thermal conductivity than the vertical portion 514 so as to restrict heat transfer from the vertical portion 514 to the pillar portion 511. As the heat insulating layer 541, for example, an air layer is used.

Further, although an air layer is used as the heat insulating layer 541 in the present embodiment, a solid layer may be used. As the solid layer, for example, a resin plate or the like is used. The resin plate may be fixed to the vertical portion 514 so as to be in sliding contact with the column portion 511, or may be fixed to the column portion 511 so as to be in sliding contact with the vertical portion 514.

By disposing the heat insulating layer 541, the heat from the intermediate portion 512 of the column portion 511 flows in while being contracted mainly by 1. The heat of the intermediate portion 512 flows into the pillar portion 511 mainly from 1 portion of the upper end surface of the pillar portion 511. Therefore, the isotherm TL at the upper end of the pillar portion 511 is closer to horizontal than in the case where the heat-insulating layer 541 is not provided. As a result, the upper end surface of the support column portion 511 can be brought close to the horizontal surface, and the upward displacement of the vertical center position of the fixed platen 110 can be restricted.

Fig. 7 is a view of the fixed platen and the fixed platen support member according to modification 2 as viewed from the mold opening/closing direction. Fig. 8 is a diagram showing an analysis example of the relationship between the temperature distribution of the fixed platen and the fixed platen support member shown in fig. 7 and the shape of the fixed platen support member.

The temperature distribution adjusting unit 540 of the present modification includes a heat transfer unit 542, and the heat transfer unit 542 transfers heat from the fixed platen 110 to the column portion 511 via the intermediate portion 512, thereby increasing the amount of heat per unit time (unit: W/s) flowing into the column portion 511 from above the column portion 511. For example, the heat transfer portion 542 transfers heat from the fixed platen 110 to the column portion 511 via the 1 st horizontal portion 513 of the intermediate portion 512, thereby increasing the amount of heat per unit time that flows from the 1 st horizontal portion 513 into the column portion 511.

The heat transfer portion 542 extends horizontally from, for example, a corner portion between the 1 st horizontal portion 513 and the vertical portion 514 toward the lateral side surface 112 of the fixed platen 110, and contacts the lateral side surface 112 of the fixed platen 110 above the edge portion 116 of the fixed platen 110. The heat transfer portion 542 may be in sliding contact with the lateral side 112 of the fixed platen 110. Since the heat transfer unit 542 is not laterally restricted by the fixed platen 110, the heat transfer unit 542 and the fixed platen 110 can be displaced relative to each other in the vertical direction. In the present embodiment, the heat transfer unit 542 is in sliding contact with the fixed platen 110, but may be fixed to the fixed platen 110.

In the present embodiment, the heat transfer portion 542 is cast integrally with the intermediate portion 512, but may be cast separately from the intermediate portion 512 and coupled to the intermediate portion 512 by bolts or the like. In the present embodiment, the heat transfer portion 542 extends horizontally from the corner portion between the 1 st horizontal portion 513 and the vertical portion 514 toward the lateral side 112 of the fixed platen 110, but the present invention is not limited thereto. The heat transfer portion 542 may extend vertically upward from the 1 st horizontal portion 513 and horizontally extend toward the lateral side surface 112 of the fixed platen 110 from the middle.

The heat of the intermediate portion 512 flows into the pillar portion 511 from 2 locations, i.e., the upper end surface of the pillar portion 511 and the sliding surface 517 of the pillar portion 511. By disposing the heat transfer portion 542, the amount of heat per unit time that flows into the column portion 511 from above the column portion 511 increases. Since the proportion of heat flowing from the upper end surface of the column portion 511 into the column portion 511 increases compared to the case where the heat transfer portion 542 is not present, the isotherm TL at the upper end portion of the column portion 511 approaches a level. As a result, the upper end surface of the support column portion 511 can be brought close to the horizontal surface, and the upward displacement of the vertical center position of the fixed platen 110 can be restricted.

The temperature distribution adjusting unit 540 includes the heat insulating layer 541 in the 1 st modification and the heat transfer unit 542 in the 2 nd modification, but the present invention is not limited to this. As shown in fig. 9, the temperature distribution adjusting portion 540 may include an uneven portion 543 that reduces the contact area between the vertical portion 514 of the intermediate portion 512 and the column portion 511.

Concave-convex portion 543 is composed of concave portion 544 and convex portion 545. Convex portions 545 may be formed between the plurality of concave portions 544, and concave portions 544 may also be formed between the plurality of convex portions 545. The convex portions 545 may be arranged in a matrix or in stripes.

The recess 544 is formed on the sliding surface 516 of the vertical portion 514, for example, without contacting the sliding surface 517 of the pillar portion 511. On the other hand, the convex portion 545 is formed on the sliding surface 516 of the vertical portion 514, for example, and contacts the sliding surface 517 of the pillar portion 511. The contact may be any of point contact, line contact, and surface contact.

Further, the concave-convex portion 543 of the present modification is formed on the sliding surface 516 of the vertical portion 514, but the present invention is not limited thereto. The concave-convex portion 543 may be formed on the sliding surface 517 of the pillar portion 511, or may be formed on both the sliding surfaces 516 and 517.

The concave-convex portion 543 reduces the contact area between the vertical portion 514 of the intermediate portion 512 and the column portion 511, thereby restricting heat transfer from the vertical portion 514 to the column portion 511. As a result, the heat of the intermediate portion 512 flows into the pillar portion 511 mainly from 1 portion of the upper end surface of the pillar portion 511. Therefore, the isotherm TL at the upper end of the strut part 511 is closer to the horizontal level than in the case where the uneven part 543 is not present. As a result, the upper end surface of the support column portion 511 can be brought close to the horizontal surface, and the upward displacement of the vertical center position of the fixed platen 110 can be restricted.

Further, the heat insulating layer 541 is used alone in the above-described modification 1, the heat transfer portion 542 is used alone in the above-described modification 2, and the uneven portion 543 is used alone in the above-described modification 3, but the present invention is not limited thereto. A plurality of techniques of the heat insulating layer 541, the heat transfer portion 542, and the uneven portion 543 may be used in any combination.

(Movable platen and supporting Member for the movable platen)

In the above embodiment, the fixed platen and the support member for the fixed platen are explained, but the movable platen and the support member for the movable platen may be configured in the same manner. The displacement of the vertical center position of the movable platen 120 can be restricted by offsetting the extension of one portion of the movable platen support member due to the temperature increase and the extension of the other portion of the movable platen support member due to the temperature increase. As a result, the positional deviation between the leader pin and the leader pin bush and the change in the balance of the mold clamping force can be restricted. Hereinafter, the difference will be mainly explained.

Fig. 10 is a view of the movable platen and the support member for the movable platen according to the embodiment as viewed from the mold opening and closing direction. The movable platen 120 and the movable platen support member 520 are formed in line symmetry with the width direction center line L3 of the movable platen 120 as the center of symmetry. Therefore, in fig. 10, the right portion (operation side portion) in fig. 10 is illustrated with reference to the width direction center line L3 of the movable platen 120, and the left portion (reverse operation side portion) in fig. 10 is not illustrated.

A virtual line passing through the center position of the movable platen 120 in the width direction (Y-axis direction) and extending in the vertical direction (Z-axis direction) is referred to as a width-direction center line L3 of the movable platen 120. An imaginary line passing through the center position of the movable platen 120 in the vertical direction and extending in the width direction is referred to as a vertical center line L4 of the movable platen 120. The mold opening and closing direction is the X-axis direction. The mold opening and closing direction is also referred to as a front-rear direction. The positive side in the X-axis direction is the front, and the negative side in the X-axis direction is the rear. The X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.

The movable platen 120 includes a movable platen body 121 to which a movable mold 820 (see fig. 1 and the like) is attached, and an edge portion 126 formed in the vertical direction center portion of the lateral side surface 122 of the movable platen body 121.

The movable platen main body portion 121 has a rectangular outer shape when viewed from the mold opening and closing direction. At four corners of the rear end surface of the movable platen body 121, tie bar insertion holes 123 are formed to penetrate the movable platen body 121 in the front-rear direction. The connection rod 140 is inserted through the connection rod insertion hole 123. A slit may be formed instead of the connecting rod insertion through hole 123. A pair of upper and lower link attachment portions 124 are provided at the widthwise central portion of the rear end surface of the movable platen body portion 121. The 1 st link 152 (see fig. 1 and the like) is swingably attached to the pair of upper and lower link attachment portions 124 via a pin 125.

The edge portion 126 is formed in the vertical direction center portion of the lateral side surface 122 of the movable platen body portion 121. The lower end surface of the edge portion 126 is, for example, a horizontal surface, and is placed on the horizontal surface of the movable platen support member 520. The lower end surface of the edge portion 126 is disposed at the same height as the vertical center line L4 of the movable platen 120, for example.

The movable platen support member 520 supports the vertical center portion of the lateral surface 122 of the movable platen 120 when viewed in the mold opening and closing direction. The movable platen support member 520 supports the movable platen 120 so as to float from the mold clamping device frame 910, and therefore the lower end surface of the movable platen 120 does not serve as an outlet port for heat from the movable platen 120. Since the vertical center portion of the lateral side 122 of the movable platen 120 serves as an outlet port for heat in the movable platen 120, the temperature distribution of the movable platen 120 becomes vertically symmetrical, and the inclination of the movable platen 120 can be suppressed.

The movable platen support member 520 includes, for example, a support column portion 521 extending in the vertical direction, and an intermediate portion 522 connecting an upper end portion of the support column portion 521 and a vertical direction center portion of the lateral side surface 122 of the fixed platen 120. The intermediate portion 522 has a displacement portion that is displaced downward with respect to the column portion 521 by thermal expansion at a position below the upper end portion of the column portion 521. The displacement portion is, for example, a hanging portion 524 described later.

The support column portion 521 has a lower end surface at a position further below the lower end surface of the movable platen 120 for the purpose of supporting the movable platen 120 so as to be raised from the mold clamping device frame 910. The lower end surface of the column 521 is fixed to the slider 102 by a bolt or the like. The slide 102 moves along the guide 101 extending in the mold opening and closing direction, and the guide 101 is laid on the mold clamping device frame 910.

The intermediate portion 522 includes a 1 st horizontal portion 523 extending horizontally from the upper end portion of the support column portion 521 toward the lateral side surface 122 of the movable platen 120, and a vertical portion 524 extending downward from the front end portion of the 1 st horizontal portion 523. The intermediate portion 522 has a 2 nd horizontal portion 525 extending horizontally from the lower end portion of the vertical portion 524 toward the lateral side surface 122 of the movable platen 120.

The hanging portion 524 is disposed between the column portion 521 and the edge portion 126 of the movable platen 120. The depending portion 524 may form a gap with the edge portion 126. Since the vertical portion 524 is not restricted in the lateral direction by the edge portion 126, it can be extended straight in the vertical direction by a temperature increase. Since the extension of the hanging portion 524 is not hindered by the edge portion 126, the extension margin of the hanging portion 524 is large.

In addition, the hanging portion 524 may be in sliding contact with the edge portion 126. At this time, the vertical portion 524 is not restricted in the lateral direction by the edge portion 126, and therefore can be extended straight in the vertical direction by a temperature increase. However, even if the vertical portion 524 is restricted in the lateral direction by the edge portion 126, the vertical portion 524 can be extended in the vertical direction by the temperature increase.

The hanging portion 524 may contact the leg portion 521. The vertical portion 524 has a sliding surface 526 in sliding contact with the stay portion 521, and the stay portion 521 has a sliding surface 527 in sliding contact with the vertical portion 524.

The vertical portion 524 and the support 521 may not be in contact with each other, and a gap may be formed between the vertical portion 524 and the support 521. When the gap is formed, the vertical portion 524 and the support portion 521 can be displaced relative to each other in the vertical direction. Further, when the gap is formed, since there is no frictional resistance, displacement is easily generated.

In the present embodiment, the movable platen 120 and the movable platen support member 520 are cast separately and fastened by the bolts 529, but may be cast integrally. In the present embodiment, the column portion 521 of the movable platen support member 520 and the intermediate portion 522 of the movable platen support member 520 are cast separately and fastened by the bolt 528, but may be cast integrally.

The heat of the movable mold 820 is transmitted to the mold clamping unit frame 910 via the movable platen 120, the intermediate portion 522 of the movable platen support member 520, and the pillar portion 521 of the movable platen support member 520. The movable mold 820 is a heat source.

The column portion 521 is heated by heat from the movable mold 820, and therefore extends in the vertical direction by a temperature increase. At this time, the lower end surface of the column portion 521 is not displaced, and the upper end surface of the column portion 521 is displaced upward. The lower end surface of the column portion 521 is not displaced because the lower end surface of the column portion 521 is fixed to the slider 102 by a bolt or the like.

The vertical portion 524 of the intermediate portion 522 is also heated by heat from the movable mold 820, similarly to the pillar portion 521, and therefore also extends in the vertical direction by a temperature increase. Since the vertical portion 524 is closer to the heat source than the pillar portion 521, the temperature of the vertical portion 524 becomes higher than the temperature of the pillar portion 521. Therefore, the elongation per unit length of the hanging portion 524 is larger than the elongation per unit length of the pillar portion 521. Therefore, the vertical dimension of the sliding surface 526 of the vertical portion 524 is larger than the vertical dimension of the sliding surface 527 of the pillar portion 521.

At this time, the upper end edge 526a of the sliding surface 526 of the vertical portion 524 is not displaced in the vertical direction with respect to the upper end edge 527a of the sliding surface 527 of the pillar portion 521. This is because the lower end surface of the 1 st horizontal portion 523 is integrally bonded to the upper end surface of the pillar portion 521. On the other hand, the lower end edge 526b of the sliding surface 526 of the vertical portion 524 is displaced downward in the vertical direction with respect to the lower end edge 527b of the sliding surface 527 of the pillar portion 521.

The elongation of the support portion 521 due to the temperature increase and the elongation of the vertical portion 524 due to the temperature increase can be cancelled out, and the displacement of the vertical center position of the movable platen 120 can be restricted. As a result, the positional deviation between the leader pin and the leader pin bush and the change in the balance of the mold clamping force can be restricted.

As described above, the heat of the movable mold 820 is transmitted to the pillar portion 521 through the intermediate portion 522. The intermediate portion 522 is closer to the heat source than the pillar portion 521. Therefore, the temperature of the intermediate portion 522 is higher than that of the pillar portion 521. Therefore, the displacement of the intermediate portion 522 is larger than that of the pillar portion 521. Therefore, a part of the extension of the pillar portion 521 due to the temperature increase and the extension of the intermediate portion 522 due to the temperature increase can be cancelled out. Therefore, the displacement of the center position of the movable platen 120 in the vertical direction due to the displacement of the support column portion 521 can be restricted.

According to the present embodiment, in order to limit the displacement of the vertical center position of the movable platen 120, the extension of one portion of the movable platen support member 520 due to the temperature increase and the extension of the other portion of the movable platen support member 520 due to the temperature increase are offset from each other. Therefore, since expensive special alloy such as invar alloy is not used, the material cost of the movable platen support member 520 can be reduced. Further, since a thermostat for adjusting the temperature of the movable platen support member 520 is not required, the structure of the mold clamping device 100 is simplified. Further, since temperature control is not necessary, the processing load of the control device 700 is small.

The technique of the present invention can be used in combination with at least 1 technique out of (1) a technique using an expensive special alloy such as invar alloy and (2) a technique using a thermostat. This is effective in further restricting the displacement of the vertical center position of the movable platen 120.

The intermediate portion 522 may be formed of a material having a higher linear expansion coefficient than the pillar portion 521. When displacements of the vertical portion 524 of the intermediate portion 522 and the column portion 521 are obtained to the same extent, the vertical portion 524 having a short vertical dimension can be used, and further the column portion 521 having a short vertical dimension can be used. Therefore, the material cost of the movable platen support member 520 can be reduced. On the other hand, if a material having a large linear expansion coefficient is selected as the material of the vertical portion 524 without changing the vertical dimension of the vertical portion 524, the degree of displacement can be increased, and the displacement of the vertical position of the movable platen 120 can be further restricted. The material of the intermediate portion 522 and the material of the column portion 521 are selected from, for example, common steel materials.

The movable platen support member 520 may have a temperature distribution adjusting unit 540, similar to the fixed platen support member 510.

(Back pressure plate and supporting Member for Back pressure plate)

In the above embodiment, the fixed platen and the fixed platen support member have been described, but the rear platen and the rear platen support member may be configured in the same manner. The displacement of the vertical center position of the rear platen can be restricted by offsetting the extension of one portion of the rear platen support member due to the temperature increase and the extension of the other portion of the rear platen support member due to the temperature increase. As a result, the change in the balance of the clamping force can be restricted.

The rear platen is disposed on the opposite side of the fixed platen 110 with respect to the movable platen 120, and is coupled to the fixed platen 110 via a coupling rod 140. The rear platen is provided with a driving device for moving the movable platen 120 forward and backward with respect to the fixed platen 110. The driving device includes a toggle mechanism 150 and a mold clamping motor 160. When the drive is toggle, the rear platen is a boss 130.

Hereinafter, the difference will be mainly explained. The driving device for advancing and retracting the movable platen 120 is not limited to a toggle type, and may be a hydraulic type, an electric type, an electromagnet type, or the like. Therefore, the rear pressure plate is not limited to the joint holder 130. The variation of the mold clamping force balance can be restricted regardless of the type of the driving device.

Fig. 11 is a view of the boss base and the boss base support member according to the embodiment as viewed from the mold opening/closing direction. The boss 130 and the boss support member 530 are formed in line symmetry with the width-direction center line L5 of the boss 130 as a center of symmetry. Therefore, in fig. 11, the right portion (the portion opposite to the operation side) in fig. 11 is illustrated with reference to the width direction center line L5 of the boss 130, and the left portion (the portion on the operation side) in fig. 11 is omitted.

A virtual line passing through the center position of the joint seat 130 in the width direction (Y-axis direction) and extending in the vertical direction (Z-axis direction) is referred to as a width-direction center line L5 of the joint seat 130. An imaginary line extending in the width direction and passing through the center position of the joint seat 130 in the vertical direction is referred to as a vertical center line L6 of the joint seat 130. The mold opening and closing direction is the X-axis direction. The mold opening and closing direction is also referred to as a front-rear direction. The positive side in the X-axis direction is the front, and the negative side in the X-axis direction is the rear. The X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.

The joint holder 130 includes a joint holder main body portion 131 to which the toggle mechanism 150 and the mold clamping motor 160 are attached, and an edge portion 136 formed in a vertical center portion of the lateral surface 132 of the joint holder main body portion 131.

The boss base main body portion 131 has a rectangular outer shape when viewed from the mold opening and closing direction. Tie bar attachment holes 133 are formed at four corners of the front end surface of the boss main body portion 131 to penetrate the boss main body portion 131 in the front-rear direction. The rear end portion of the link 140 is inserted into the link mounting hole 133. A pair of upper and lower link attachment portions 134 are provided at the widthwise center portion of the front end surface of the boss body portion 131. A 2 nd link 153 (see fig. 1 and the like) is swingably attached to each of the pair of upper and lower link attachment portions 134 via a pin 135.

The edge 136 is formed at the vertical center of the lateral surface 132 of the boss body 131. The lower end surface of the edge portion 136 is, for example, a horizontal surface, and is placed on the horizontal surface of the joint seat support member 530. The lower end surface of the edge portion 136 is disposed at the same height as the vertical center line L6 of the boss base 130, for example.

The joint seat support member 530 supports the vertical center portion of the lateral surface 132 of the joint seat 130 when viewed in the mold opening and closing direction. Since the joint seat support member 530 supports the joint seat 130 in a floating manner from the mold clamping device frame 910, the lower end surface of the joint seat 130 does not serve as an outlet port for heat from the joint seat 130. Since the vertical center portion of the lateral surface 132 of the joint seat 130 serves as a heat outlet port in the joint seat 130, the temperature distribution of the joint seat 130 is vertically symmetrical, and the inclination of the joint seat 130 can be suppressed.

The joint seat support member 530 includes, for example, a support column portion 531 extending in the vertical direction and an intermediate portion 532 connecting an upper end portion of the support column portion 531 and a vertical center portion of the lateral side surface 132 of the joint seat 130. The intermediate portion 532 has a displacement portion that is displaced downward with respect to the support portion 531 by thermal expansion at a position lower than the upper end portion of the support portion 531. The displacement portion is, for example, a hanging portion 534 described later.

For the purpose of supporting the journal seat 130 by floating from the mold clamping device frame 910, the pillar portion 531 has a lower end surface at a position lower than the lower end surface of the journal seat 130. The lower end surface of the support portion 531 is movably mounted on the mold clamping device frame 910 in the mold opening/closing direction. The lower end surface of the support portion 531 is fixed to a slider that moves along a guide laid on the mold clamping device frame 910 by bolts or the like.

The intermediate portion 532 includes a 1 st horizontal portion 533 extending horizontally from the upper end portion of the support portion 531 toward the lateral side surface 132 of the joint base 130, and a vertical portion 534 extending downward from the front end portion of the 1 st horizontal portion 533. The intermediate portion 532 has a 2 nd horizontal portion 535 extending horizontally from the lower end of the vertical portion 534 toward the lateral side 132 of the joint base 130.

The hanging portion 534 is disposed between the support portion 531 and the edge portion 136 of the boss 130. The depending portion 534 may form a gap with the edge portion 136. Since the vertical portion 534 is not restricted in the lateral direction by the edge portion 136, it can extend straight in the vertical direction by a temperature increase. Since the extension of the hanging portion 534 is not hindered by the edge portion 136, the extension margin of the hanging portion 534 is large.

In addition, the hanging portion 534 may be in sliding contact with the edge portion 136. At this time, the vertical portion 534 is not restricted in the lateral direction by the edge portion 136, and therefore can be extended straight in the vertical direction by a temperature increase. However, even if the vertical portion 534 is laterally restricted by the edge portion 136, the vertical portion 534 can extend in the vertical direction by a temperature increase.

The hanging portion 534 may contact the pillar portion 531. The vertical portion 534 has a sliding surface 536 that is in sliding contact with the support portion 531, and the support portion 531 has a sliding surface 537 that is in sliding contact with the vertical portion 534.

The vertical portion 534 may not contact the support portion 531, and a gap may be formed between the vertical portion 534 and the support portion 531. When a gap is formed, the vertical portion 534 and the support portion 531 can be displaced relative to each other in the vertical direction. Further, when the gap is formed, since there is no frictional resistance, displacement is easily generated.

In the present embodiment, the boss 130 and the boss support member 530 are cast separately and fastened by the bolt 539, but they may be cast integrally. In the present embodiment, the pillar portion 531 of the joint seat support member 530 and the intermediate portion 532 of the joint seat support member 530 are cast separately and fastened by the bolt 538, but may be cast integrally.

The heat of the mold clamping motor 160 is transmitted to the mold clamping device frame 910 via the boss 130, the intermediate portion 532 of the boss supporting member 530, and the pillar portion 531 of the boss supporting member 530. The clamp motor 160 is a heat source.

The support portion 531 is heated by heat from the mold clamping motor 160, and therefore extends in the vertical direction by a temperature increase. At this time, the lower end surface of the support portion 531 is not displaced, and the upper end surface of the support portion 531 is displaced upward. The reason why the lower end surface of the pillar portion 531 is not displaced is that the lower end surface of the pillar portion 531 is placed on the mold clamping device frame 910.

The vertical portion 534 of the intermediate portion 532 is also heated by heat from the mold clamping motor 160, similarly to the support portion 531, and therefore also extends in the vertical direction by a temperature increase. Since the vertical portion 534 is closer to the heat source than the pillar portion 531, the temperature of the vertical portion 534 becomes higher than the temperature of the pillar portion 531. Therefore, the elongation per unit length of the hanging portion 534 is larger than the elongation per unit length of the column portion 531. Therefore, the vertical dimension of the sliding surface 536 of the vertical portion 534 becomes larger than the vertical dimension of the sliding surface 537 of the pillar portion 531.

At this time, the upper end edge 536a of the sliding surface 536 of the vertical portion 534 is not displaced in the vertical direction with respect to the upper end edge 537a of the sliding surface 537 of the pillar portion 531. This is because the lower end surface of the 1 st horizontal portion 533 is integrally bonded to the upper end surface of the support 531. On the other hand, the lower end edge 536b of the sliding surface 536 of the vertical portion 534 is displaced downward in the vertical direction with respect to the lower end edge 537b of the sliding surface 537 of the pillar portion 531.

The displacement of the vertical center position of the joint holder 130 can be restricted by offsetting the extension of the support portion 531 caused by the temperature increase and the extension of the vertical portion 534 caused by the temperature increase. As a result, the change in the balance of the clamping force can be restricted.

As described above, the heat of the mold clamping motor 160 is transmitted to the pillar portion 531 through the intermediate portion 532. The middle portion 532 is closer to the heat source than the pillar portion 531. Therefore, the temperature of the intermediate portion 532 is higher than the temperature of the pillar portion 531. Therefore, the displacement of the intermediate portion 532 is larger than that of the pillar portion 531. Therefore, a part of the extension of the pillar portion 531 due to the temperature rise and the extension of the intermediate portion 532 due to the temperature rise can be cancelled out. Therefore, the displacement of the vertical center position of the boss base 130 due to the displacement of the support portion 531 can be restricted.

According to the present embodiment, in order to regulate the displacement of the vertical center position of the joint seat 130, the extension of one portion of the joint seat support member 530 due to the temperature increase and the extension of the other portion of the joint seat support member 530 due to the temperature increase are offset from each other. Therefore, since expensive special alloy such as invar alloy is not used, the material cost of the bearing member 530 for the joint seat can be reduced. Further, since a thermostat for adjusting the temperature of the joint holder support member 530 is not required, the structure of the mold clamping device 100 is simplified. Further, since temperature control is not necessary, the processing load of the control device 700 is small.

The technique of the present invention can be used in combination with at least 1 technique out of (1) a technique using an expensive special alloy such as invar alloy and (2) a technique using a thermostat. This is effective in further restricting the displacement of the vertical center position of the joint holder 130.

The intermediate portion 532 may be formed of a material having a larger linear expansion coefficient than the pillar portion 531. When displacements of the vertical portion 534 and the support portion 531 of the intermediate portion 532 are obtained to the same degree, the vertical portion 534 having a short vertical dimension can be used, and the support portion 531 having a short vertical dimension can also be used. Therefore, the material cost of the joint seat support member 530 can be reduced. On the other hand, if a material having a large linear expansion coefficient is selected as the material of the vertical portion 534 without changing the vertical dimension of the vertical portion 534, the degree of displacement can be increased, and the displacement of the vertical position of the joint holder 130 can be further restricted. The material of the intermediate portion 532 and the material of the pillar portion 531 are selected from, for example, general steel materials.

The joint seat support member 530 may have a temperature distribution adjusting unit 540, similar to the stationary platen support member 510.

(modification example etc.)

The embodiment of the injection molding machine has been described above, but the present invention is not limited to the above embodiment and the like. Various changes, modifications, substitutions, additions, deletions, and combinations can be made within the scope of the claims. These are, of course, within the technical scope of the present invention.

Claims (8)

1. An injection molding machine, wherein,

comprises at least one of a fixed pressure plate, a movable pressure plate and a rear pressure plate,

the fixed pressing plate is provided with a fixed die,

the movable pressure plate is provided with a movable mould,

the rear platen is disposed on the opposite side of the fixed platen with respect to the movable platen, and is coupled to the fixed platen via a coupling rod,

the injection molding machine further comprises a support member supporting at least 1 platen selected from the fixed platen, the movable platen, and the rear platen from both sides,

the support member has a support column portion extending in the vertical direction and an intermediate portion connecting the support column portion and the pressure plate,

the support member on either side can cancel each other out the extension of the column section due to a temperature rise and the extension of the intermediate section due to a temperature rise.

2. The injection molding machine according to claim 1,

the intermediate portion has a displacement portion that is displaced downward relative to the pillar portion by thermal expansion at a position below an upper end portion of the pillar portion.

3. The injection molding machine according to claim 2,

the support member has a temperature distribution adjusting portion for making the slope of the isotherm at the upper end portion of the column portion close to horizontal.

4. The injection molding machine according to claim 3,

the temperature distribution adjustment portion includes a heat insulating layer that restricts heat transfer from the displacement portion to the pillar portion at a gap between the displacement portion and the pillar portion of the intermediate portion.

5. The injection molding machine according to claim 3 or 4,

the temperature distribution adjusting portion includes a concave-convex portion that reduces a contact area between the displacement portion of the intermediate portion and the pillar portion.

6. The injection molding machine according to any one of claims 3 to 5,

the temperature distribution adjusting portion includes a heat transfer portion that transfers heat from the platen to the column portion via the intermediate portion, thereby increasing an amount of heat per unit time that flows into the column portion from above the column portion.

7. The injection molding machine according to any one of claims 2 to 6,

the intermediate portion has: a 1 st horizontal portion extending horizontally from an upper end portion of the pillar portion toward a lateral side of the platen; a vertical portion extending downward from a front end portion of the 1 st horizontal portion; and a 2 nd horizontal portion extending horizontally from a lower end portion of the vertical portion toward the lateral side of the platen,

the vertical part is the displacement part.

8. The injection molding machine according to any one of claims 2 to 7,

the intermediate portion is formed of a material having a greater linear expansion coefficient than the pillar portion.

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