DE102023130272A1 - INJECTION MOLDING MACHINE CONTROL DEVICE AND INJECTION MOLDING MACHINE DISPLAY UNIT - Google Patents

Abstract

An occurrence of a defective product is reduced via monitoring gas combustion of a molded product. A control device (700) of an injection molding machine (10) according to an embodiment comprises: a detection unit (712) configured to detect information indicating a pressure from a detection unit (841) provided in the vicinity of an end portion at which a molding material (M) to be filled into a cavity space (801) formed in a molding unit (800) of the injection molding machine (10) enters the cavity space (801); and a control unit configured to determine whether or not gas combustion has occurred in a molded product produced by the injection molding machine (10), or to estimate or indicate a period until gas combustion occurs in the molded product, based on a predetermined condition related to the pressure detected at a time near a time when a filling process of the injection molding machine (10) is switched to a pressure holding process or near a time when the cavity space (801) is filled with the molding material (M) up to the end portion.

Description

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to a control device of an injection molding machine and a display unit of the injection molding machine.

Description of the state of the art

Heretofore, there has been a technique for monitoring a state during filling of a molding material in an injection process. A technique for detecting a filling pressure and controlling a rotational speed of a screw according to a pressure change rate is disclosed in, for example, a technique disclosed in Japanese Unexamined Patent Publication No. 1991-030926 Accordingly, injection molding can be performed in a state where flow resistance of the molding material is appropriate.

Meanwhile, a molding material flows into cavity spaces formed in a molding unit in an injection molding machine so that molded products are produced. The cavity spaces are formed on a parting surface between a stationary mold and a movable mold. In a case where the molding material flows into the cavity spaces, gas present in the cavity spaces is discharged to the outside via the parting surface. Accordingly, the cavity spaces can be filled with the molding material. Since components of the molding material are deposited on the parting surface in a case where injection molding is repeatedly performed, it is difficult for gas to be discharged to the outside of the cavity spaces. In this case, since a temperature of gas that is not discharged rises to a high temperature due to adiabatic compression of the gas, gas combustion is likely to occur in the molded product.

SUMMARY OF THE INVENTION

Japanese Unexamined Patent Publication No. 1991-030926 However, only discloses a technique for controlling the rotational speed of the screw according to the detected filling pressure and does not disclose a technique for monitoring gas combustion occurring in a molded product when injection molding is repeatedly performed.

One aspect of the present invention provides a technique for reducing the occurrence of a defective product by monitoring gas combustion of a molded product.

A control device of an injection molding machine according to an aspect of the present invention includes: a detection unit configured to detect information indicating a pressure from a detection unit provided near an end portion at which a molding material to be filled into a cavity space formed in a molding unit of the injection molding machine enters the cavity space; and a control unit configured to determine whether or not gas combustion has occurred in a molded product produced by the injection molding machine, or to estimate or indicate a period until gas combustion occurs in the molded product, based on a predetermined condition related to the pressure detected at a time near a time when a filling process of the injection molding machine is switched to a pressure holding process or near a time when the cavity space is filled with the molding material up to the end portion.

According to the aspect of the present invention, the occurrence of a defective product is reduced via monitoring the gas combustion of a molded product.

SHORT DESCRIPTION OF THE CHARACTERS

• 1 is a diagram showing a state of an injection molding machine according to an embodiment at the completion time of mold opening.
• 2 is a diagram showing a state of the injection molding machine according to the embodiment at the time of mold closing/clamping.
• 3 is a diagram showing components of a control device of an injection molding machine according to a first embodiment as functional blocks.
• 4 is a diagram showing a molding material flowing into a molding unit according to the first embodiment and a sensor provided in the molding unit.
• 5(A) to 5(D) are diagrams showing a change in the flow of the molding material in the molding unit according to the first embodiment.
• 6 is a graph showing changes in temperature and pressure from the start of filling to pressure holding in the molding unit according to the first embodiment.
• 7 is a diagram showing a pressure change detected by the sensor in a case where a packed state is achieved in the molding unit according to the first embodiment.
• 8th is a diagram illustrating a pressure change detected by the sensor at the time of V/P switching in the molding unit according to the first embodiment.
• 9 is a diagram illustrating a log information screen output from a display control unit according to the first embodiment.
• 10 is a flowchart showing a processing procedure until gas combustion is detected in the injection molding machine according to the first embodiment.
• 11 is a diagram illustrating a gas combustion prediction information screen output from a display control unit according to a second embodiment.
• 12 is a flowchart showing a processing procedure until an alarm is issued in a control device according to the second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described below with reference to the drawings. Furthermore, the embodiments to be described below do not limit the present invention and are merely illustrative. Not all features and combinations thereof described in the embodiments are necessarily essential to the present invention. The same or corresponding components are denoted by the same or corresponding reference numerals in the respective drawings, and the description thereof will be omitted.

1 is a diagram showing a state of an injection molding machine according to a first embodiment at the completion time of mold opening. 2 is a diagram showing a state of the injection molding machine according to the first embodiment at the time of mold closing/clamping. In this specification, an X-axis direction, a Y-axis direction, and a Z-axis direction are mutually perpendicular directions. The X-axis direction and the Y-axis direction indicate horizontal directions, and the Z-axis direction indicates a vertical direction. In a case where a mold closing/clamping unit 100 is of a horizontal type, the X-axis direction is a mold opening/closing direction, and the Y-axis direction is a width direction of an injection molding machine 10. A negative side in the Y-axis direction is referred to as an operation side, and a positive side in the Y-axis direction is referred to as a counter operation side.

As in 1 and 2 , the injection molding machine 10 includes a mold closing/clamping unit 100 that opens and closes a mold unit 800, an ejector unit 200 that ejects molded products molded by the mold unit 800, an injection unit 300 that injects a molding material into the mold unit 800, a moving unit 400 that causes the injection unit 300 to move back and forth with respect to the mold unit 800, a controller 700 that controls the respective components of the injection molding machine 10, and a frame 900 that supports the respective components of the injection molding machine 10. The frame 900 includes a mold closing/clamping unit frame 910 that supports the mold closing/clamping unit 100 and an injection unit frame 920 that supports the injection unit 300. The mold closing/clamping unit frame 910 and the injection unit frame 920 are each installed on a floor 2 via height adjusters 930. The control device 700 is arranged in an interior of the injection unit frame 920. The respective components of the injection molding machine 10 are described below.

(Mold closing/clamping unit)

In describing the mold closing/clamping unit 100, a moving direction of a movable platen 120 in a case where a mold is to be closed (for example, a positive X-axis direction) corresponds to a front side, and a moving direction of the movable platen 120 in a case where the mold is to be opened (for example, a negative X-axis direction) corresponds to a back side.

The mold closing/clamping unit 100 performs mold closing, pressurization, mold closing/clamping, pressure release, and mold opening of the mold unit 800. The mold unit 800 includes a stationary mold 810 and a movable mold 820. The mold closing/clamping unit 100 is of a horizontal type, for example, and the mold opening/closing direction of the mold closing/clamping unit 100 is a horizontal direction. The mold closing/clamping unit 100 includes a stationary platen 110 to which the stationary mold 810 is attached, the movable platen 120 to which the movable mold 820 is attached, and a moving mechanism 102 that moves the movable platen 120 with respect to the stationary platen 110 in the mold opening/closing direction.

The stationary platen 110 is fixed to the mold closing/clamping unit frame 910. The stationary mold 810 is fixed to a surface of the sta tional plate 110 which faces the movable plate 120.

The movable platen 120 is arranged to be movable with respect to the mold closing/clamping unit frame 910 in the mold opening/closing direction. Guides 101 that guide the movable platen 120 are laid on the mold closing/clamping unit frame 910. The movable mold 820 is attached to a surface of the movable platen 120 that faces the stationary platen 110.

The moving mechanism 102 causes the movable platen 120 to move back and forth with respect to the stationary platen 110 to perform mold closing, pressurization, mold closing/clamping, pressure release, and mold opening of the molding unit 800. The moving mechanism 102 includes a toggle beam 130 arranged with a distance between the stationary platen 110 and itself, columns 140 connecting the stationary platen 110 to the toggle beam 130, a toggle mechanism 150 that moves the movable platen 120 with respect to the toggle beam 130 in the mold opening/closing direction, a mold closing/clamping motor 160 that operates the toggle mechanism 150, a motion converting mechanism 170 that converts a rotational motion of the mold closing/clamping motor 160 into a linear motion, and a mold space adjusting mechanism 180 that adjusts a distance between the stationary platen 110 and the toggle beam 130.

The toggle beam 130 is arranged with a gap between the stationary platen 110 and itself, and is placed on the mold closing/clamping unit frame 910 so as to be movable in the mold opening/closing direction. The toggle beam 130 may be arranged so as to be movable along guides laid on the mold closing/clamping unit frame 910. The guides for the toggle beam 130 may be common to the guides 101 for the movable platen 120.

In the present embodiment, the stationary platen 110 is fixed to the mold clamping unit frame 910, and the toggle bracket 130 is arranged to be movable relative to the mold clamping unit frame 910 in the mold opening/closing direction. However, the toggle bracket 130 may be fixed to the mold clamping unit frame 910, and the stationary platen 110 may be arranged to be movable relative to the mold clamping unit frame 910 in the mold opening/closing direction.

The columns 140 connect the stationary platen 110 to the toggle beam 130 with a distance L between the stationary platen 110 and the toggle beam 130 in the mold opening/closing direction. A plurality (for example, four) of the columns 140 may be used. The plurality of columns 140 are arranged parallel to the mold opening/closing direction and extend depending on a mold closing/clamping force. At least one column 140 may be provided with a column strain detector 141 that measures a strain of the column 140. The column strain detector 141 sends a signal indicating the detection result thereof to the controller 700. The detection result of the column strain detector 141 may be used for measurement of a mold closing/clamping force and the like.

The column strain detector 141 is used as a mold clamping force detector for detecting a mold clamping force in the present embodiment, but the present invention is not limited thereto. The mold clamping force detector is not limited to a type of strain gauge, and may be of a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, or the like. A position where the mold clamping force detector is mounted is also not limited to the column 140.

The toggle mechanism 150 is arranged between the movable platen 120 and the toggle beam 130, and moves the movable platen 120 with respect to the toggle beam 130 in the mold opening/closing direction. The toggle mechanism 150 includes a crosshead 151 that moves in the mold opening/closing direction, and a pair of link groups that are flexed and extended in response to the movement of the crosshead 151. Each of the pair of link groups includes first and second links 152 and 153 that are flexibly and extendably connected to each other by a pin or the like. The first link 152 is oscillatively attached to the movable platen 120 by a pin or the like. The second link 153 is oscillatively attached to the toggle beam 130 by a pin or the like. The second link 153 is attached to the crosshead 151 via a third link 154. In a case where the crosshead 151 is caused to move back and forth with respect to the toggle bracket 130, the first and second links 152 and 153 are flexed and extended, and the movable plate 120 moves back and forth with respect to the toggle bracket 130.

The configuration of the toggle mechanism 150 is not limited to the configuration shown in 1 and 2 shown. In 1 and 2 For example, the number of nodes of each link group is five, but may be four. An end portion of the third link 154 may be connected to the node between the first and second links 152 and 153.

The mold closing/clamping motor 160 is attached to the toggle beam 130 and operates the toggle mechanism 150. The mold closing/clamping motor 160 causes the crosshead 151 to move forward and backward with respect to the toggle beam 130 so that the first and second links 152 and 153 are flexed and extended to cause the movable platen 120 to move forward and backward with respect to the toggle beam 130. The mold closing/clamping motor 160 is directly connected to the motion conversion mechanism 170, but may be connected to the motion conversion mechanism 170 via a belt, pulleys, and the like.

The motion conversion mechanism 170 converts a rotary motion of the mold clamping motor 160 into a linear motion of the crosshead 151. The motion conversion mechanism 170 includes a spindle shaft and a spindle nut screwed to the spindle shaft. Balls or rollers may be interposed between the spindle shaft and the spindle nut.

The mold closing/clamping unit 100 performs a mold closing process, a pressurizing process, a mold closing/clamping process, a pressure releasing process, a mold opening process, and the like under the control of the controller 700.

In the mold clamping process, the mold clamping/clamping motor 160 is driven to cause the crosshead 151 to advance at a set moving speed to a mold clamping completion position so that the movable platen 120 is caused to advance and the movable mold 820 is caused to contact the stationary mold 810. The position and the moving speed of the crosshead 151 are measured using, for example, a mold clamping/clamping motor encoder 161 or the like. The mold clamping/clamping motor encoder 161 measures the rotation of the mold clamping/clamping motor 160 and sends a signal indicating the detection result thereof to the controller 700.

A crosshead position detector for measuring the position of the crosshead 151 and a crosshead movement speed detector for measuring the movement speed of the crosshead 151 are not limited to the mold clamping/clamping motor encoder 161, and general detectors may be used. Further, a movable platen position detector for measuring the position of the movable platen 120 and a movable platen movement speed detector for measuring the movement speed of the movable platen 120 are not limited to the mold clamping/clamping motor encoder 161, and general detectors may be used.

In the pressurizing process, the mold closing/clamping motor 160 is further driven to cause the crosshead 151 to further advance from the mold closing completion position to a mold closing/clamping position and generate a mold closing/clamping force.

In the mold closing/clamping process, the mold closing/clamping motor 160 is driven to maintain the position of the crosshead 151 in the mold closing/clamping position. In the mold closing/clamping process, the mold closing/clamping force generated in the pressurizing process is maintained. In the mold closing/clamping process, cavity spaces 801 (see 2 ) is formed, and the injection unit 300 fills the cavity spaces 801 with liquid molding material. Molded products are obtained in a case where the molding material filling the cavity spaces is solidified.

One cavity space 801 may be provided, or a plurality of cavity spaces 801 may be provided. In the latter case, a plurality of molded products are obtained simultaneously. A feed material may be arranged in a part of each cavity space 801, and the other part of each cavity space 801 may be filled with a molding material. Molded products in which the feed material and the molding material are integrated with each other are obtained.

In the pressure release process, the mold closing/clamping motor 160 is driven to cause the crosshead 151 to move backward from the mold closing/clamping position to a mold opening start position so that the movable platen 120 is caused to move backward to reduce the mold closing/clamping force. The mold opening start position and the mold closing completion position may be the same position.

In the mold opening process, the mold closing/clamping motor 160 is driven to cause the crosshead 151 to move backward at a set movement speed from the mold opening start position to a mold opening completion position, so that the movable platen 120 is caused to move backward and causes the movable mold 820 to be separated from the stationary mold 810. Thereafter, the ejector unit 200 ejects the molded products from the movable mold 820.

Setting conditions in the mold clamping process, the pressurizing process, and the mold clamping/clamping process are collectively set as a series of setting conditions. For example, moving speeds and positions (including a mold clamping start position, a moving speed switching position, a mold clamping completion position, and a mold clamping/clamping position) of the crosshead 151 and mold clamping/clamping forces in the mold clamping process and the pressurizing process are collectively set as a series of setting conditions. The mold clamping start position, the moving speed switching position, the mold clamping completion position, and the mold clamping/clamping position are arranged in this order from a back side to the front side, and indicate start points and end points of sections in which the moving speeds are set. The moving speed is set for each section. One moving speed switching position may be set, or multiple moving speed switching positions may be set. The moving speed switching position may not be set. It may be that only the mold closing/clamping position or the mold closing/clamping force is adjusted.

Setting conditions in the pressure-relieving process and the mold-opening process are also collectively set in the same manner. For example, movement speeds and positions (including the mold-opening start position, the movement speed switching position, and the mold-opening completion position) of the crosshead 151 in the pressure-relieving process and the mold-opening process are collectively set as a series of setting conditions. The mold-opening start position, the movement speed switching position, and the mold-opening completion position are arranged in this order from a front side to the back side, and indicate start points and end points of sections in which the movement speeds are set. The movement speed is set for each section. One movement speed switching position may be set, or multiple movement speed switching positions may be set. The movement speed switching position may not be set. The mold-opening start position and the mold-closing completion position may be the same position. Further, the mold-opening completion position and the mold-closing start position may be the same position.

The moving speeds, positions, and the like of the movable platen 120 may be set instead of the moving speeds, positions, and the like of the crosshead 151. Further, a mold closing/clamping force may be set instead of the position (for example, the mold closing/clamping position) of the crosshead or the position of the movable platen.

Meanwhile, the toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits the amplified driving force to the movable platen 120. The amplification factor of the toggle mechanism 150 is also referred to as a toggle factor. The toggle factor is changed depending on an angle θ between the first and second links 152 and 153 (hereinafter also referred to as a "link angle θ"). The link angle θ is obtained from the position of the crosshead 151. In a case where the link angle θ is 180°, the toggle factor is maximum.

In a case where the thickness of the mold unit 800 is changed due to replacement of the mold unit 800, a change in temperature of the mold unit 800, or the like, a mold space is adjusted so that a predetermined mold closing/clamping force is obtained during mold closing/clamping. In adjusting a mold space, the distance L between the stationary platen 110 and the toggle bracket 130 is adjusted so that the link angle θ of the toggle mechanism 150 at a time of mold contact at which, for example, the movable mold 820 contacts the stationary mold 810 is a predetermined angle.

The mold closing/clamping unit 100 includes a mold space adjusting mechanism 180. The mold space adjusting mechanism 180 adjusts the distance L between the stationary platen 110 and the toggle bracket 130 to adjust a mold space. A time at which a mold space is adjusted is, for example, between the end of a molding cycle and the start of the next molding cycle. The mold space adjusting mechanism 180 includes, for example, spin spindle shafts 181 formed at rear end portions of the columns 140, spindle nuts 182 rotatably supported by the toggle bracket 130 so as not to be able to move back and forth, and a mold space adjusting motor 183 which rotates the spindle nuts 182 screwed to the spindle shafts 181.

The spindle shaft 181 and the spindle nut 182 are provided for each column 140. A rotational driving force of the mold space adjusting motor 183 can be transmitted to a plurality of spindle nuts 182 via a rotational driving force transmission unit 185. The plurality of spindle nuts 182 can be rotated synchronously. It is also possible to rotate the plurality of spindle nuts 182 individually by changing a transmission channel of the rotational driving force transmission unit 185.

The rotational driving force transmission unit 185 includes, for example, gears and the like. In this case, a driven gear is formed on an outer periphery of each spindle nut 182, a driving gear is attached to an output shaft of the mold space adjusting motor 183, and an intermediate gear that meshes with the plurality of driven gears and the driving gear is rotatably supported at a center portion of the toggle bracket 130. The rotational driving force transmission unit 185 may include a belt, pulleys and the like instead of the gears.

The operation of the mold space adjusting mechanism 180 is controlled by the controller 700. The controller 700 drives the mold space adjusting motor 183 to rotate the spindle nuts 182. As a result, the position of the toggle bracket 130 with respect to the columns 140 is adjusted so that the distance L between the stationary platen 110 and the toggle bracket 130 is adjusted. A plurality of mold space adjusting mechanisms may be used in combination.

The distance L is measured using a mold space adjusting motor encoder 184. The mold space adjusting motor encoder 184 measures a rotation amount and a rotation direction of the mold space adjusting motor 183, and sends signals indicating the detection results thereof to the controller 700. The detection results of the mold space adjusting motor encoder 184 are used for monitoring and controlling the position of the toggle beam 130 and the distance L. A toggle beam position detector for measuring the position of the toggle beam 130 and a distance detector for measuring the distance L are not limited to the mold space adjusting motor encoder 184, and general detectors can be used.

The mold closing/clamping unit 100 may include a mold temperature controller that adjusts the temperature of the mold unit 800. The mold unit 800 includes a flow channel for a temperature control medium therein. The mold temperature controller adjusts the temperature of a temperature control medium supplied to the flow channel of the mold unit 800 to adjust the temperature of the mold unit 800.

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

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

(Ejector unit)

In describing the ejector unit 200, as in describing the mold closing/clamping unit 100, the moving direction of the movable platen 120 in a case where the mold is to be closed (for example, the positive X-axis direction) corresponds to a front side, and the moving direction of the movable platen 120 in a case where the mold is to be opened (for example, the negative X-axis direction) corresponds to a back side.

The ejector unit 200 is attached to the movable platen 120 and moves back and forth together with the movable platen 120. The ejector unit 200 includes ejector rods 210 that eject the molded products from the molding unit 800 and a drive mechanism 220 that moves the ejector rods 210 in the moving direction of the movable platen 120 (X-axis direction).

The ejector rods 210 are arranged in through holes of the movable plate 120 so as to be able to move forward and backward. Front end portions of the ejector rods 210 are in contact with an ejector plate 826 of the movable mold 820. The front end portions of the ejector rods 210 can be connected to the They may or may not be connected to the ejector plate 826.

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

The ejector unit 200 performs an ejection process under the control of the controller 700. In the ejection process, the ejector rods 210 are caused to move forward from a standby position to an ejection position at a set moving speed so that the ejector plate 826 is caused to move forward to eject the molded products. Thereafter, the ejector motor is driven to cause the ejector rods 210 to move backward at a set moving speed and cause the ejector plate 826 to move backward to the original standby position.

The position and the moving speed of each ejector rod 210 are measured using, for example, an ejector motor encoder. The ejector motor encoder measures the rotation of the ejector motor and sends a signal indicating the detection result thereof to the controller 700. An ejector rod position detector for measuring the position of each ejector rod 210 and an ejector rod moving speed detector for measuring the moving speed of each ejector rod 210 are not limited to the ejector motor encoder, and general detectors can be used.

(injection unit)

In the description of the injection unit 300, different from the description of the mold closing/clamping unit 100 and the description of the ejector unit 200, a moving direction of a screw 330 during filling (for example, the negative X-axis direction) corresponds to a front side, and a moving direction of the screw 330 during metering (for example, the positive X-axis direction) corresponds to a rear side.

The injection unit 300 is installed on a sliding base 301, and the sliding base 301 is arranged to be able to move forward and backward with respect to the injection unit frame 920. The injection unit 300 is arranged to be able to move forward and backward with respect to the mold unit 800. The injection unit 300 contacts the mold unit 800 and fills the cavity spaces 801 formed in the mold unit 800 with a molding material metered in a cylinder 310. The injection unit 300 includes, for example, a cylinder 310 that heats the molding material, a nozzle 320 provided at a front end portion of the cylinder 310, the screw 330 that is arranged in the cylinder 310 so as to be able to move back and forth and is rotatable, a metering motor 340 that rotates the screw 330, an injection motor 350 that causes the screw 330 to move back and forth, and a load detector 360 that measures a load transmitted between the injection motor 350 and the screw 330.

The cylinder 310 heats the molding material supplied from a supply port 311 to the inside. The molding material contains, for example, a resin and the like. The molding material is formed in the form of pellets, for example, and is supplied to the supply port 311 in a solid state. The supply port 311 is formed at a rear portion of the cylinder 310. A cooler 312 such as a water cooling cylinder is provided at an outer periphery of the rear portion of the cylinder 310. Heating units 313 such as band heaters and temperature gauges 314 are provided at the outer periphery of the cylinder 310 in front of the cooler 312.

The cylinder 310 is divided into a plurality of zones in an axial direction of the cylinder 310 (for example, the X-axis direction). The heating unit 313 and the temperature measuring device 314 are provided in each of the plurality of zones. In each of the plurality of zones, a set temperature is set, and the control device 700 controls the heating units 313 so that temperatures measured by the temperature measuring devices 314 reach the set temperatures.

The nozzle 320 is provided at the front end portion of the cylinder 310 and is pressed against the molding unit 800. The heating units 313 and the temperature measuring device 314 are provided at an outer periphery of the nozzle 320. The control device 700 controls the heating units 313 so that the measuring temperature of the nozzle 320 reaches a setting temperature.

The screw 330 is arranged in the cylinder 310 so that it is able to move forward and to move backward, and is rotatable. In a case where the screw 330 is rotated, a molding material is fed forward along a spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 while being fed forward. When the liquid molding material is fed to the front of the screw 330 and accumulated in the front portion of the cylinder 310, the screw 330 is caused to move backward. Thereafter, in a case where the screw 330 is caused to move forward, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320, and the molding unit 800 is filled with the molding material.

At a front portion of the screw 330, a backflow prevention ring 331 is attached so as to be able to move back and forth as a backflow prevention valve that prevents the backflow of the molding material flowing backward from the front of the screw 330 in a case where the screw 330 is pushed forward.

In a case where the screw 330 is caused to move forward, the backflow prevention ring 331 is pushed backward by the pressure of the molding material accumulated in front of the screw 330 and moves backward relative to the screw 330 to a closing position (see 2 ) at which the flow channel for a molding material is closed. Accordingly, the molding material accumulated in front of the screw 330 is prevented from flowing to the rear side.

On the other hand, in a case where the screw 330 is rotated, the backflow prevention 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 relative to the screw 330 to an opening position (see 1 ), at which the flow channel for a molding material is opened. Accordingly, the molding material is conveyed to the front of the screw 330.

The backflow prevention ring 331 may be either of a co-rotating type that is rotated together with the screw 330 or a non-rotating type that is not rotated together with the screw 330.

The injection unit 300 may include a drive source that causes the backflow prevention ring 331 to move back and forth with respect to the screw 330 between the opening position and the closing position.

The metering motor 340 rotates the screw 330. A drive source that rotates the screw 330 is not limited to the metering motor 340 and may be, for example, a hydraulic pump or the like.

The injection motor 350 causes the screw 330 to move forward and backward. A motion conversion mechanism that converts a rotational motion of the injection motor 350 into a linear motion of the screw 330 and the like are provided between the injection motor 350 and the screw 330. The motion conversion mechanism includes, for example, a screw shaft and a screw nut screwed to the screw shaft. Balls, rollers, or the like may be provided between the screw shaft and the screw nut. A drive source that causes the screw 330 to move forward and backward is not limited to the injection motor 350, and may be, for example, a hydraulic cylinder or the like.

The load detector 360 measures a load transmitted between the injection motor 350 and the screw 330. The measured load is converted into a pressure by the control device 700. The load detector 360 is provided in a transmission channel for a load between the injection motor 350 and the screw 330 and measures a load acting on the load detector 360.

The load detector 360 sends a signal of the measured load to the controller 700. The load measured by the load detector 360 is converted into a pressure acting between the screw 330 and the molding material, and is used to control and monitor a pressure received by the screw 330 from the molding material, a back pressure acting on the screw 330, a pressure acting from the screw 330 on the molding material, and the like.

A pressure detector that measures the pressure of the molding material is not limited to the load detector 360, and a general detector may be used. For example, a nozzle pressure sensor or a mold internal pressure sensor may be used. The nozzle pressure sensor is installed in the nozzle 320. The mold internal pressure sensor is installed in the molding unit 800.

The injection unit 300 performs a metering process, a filling process, a pressure-holding process, and the like under the control of the controller 700. The filling process and the pressure-holding process may also be collectively referred to as an injection process.

In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set speed to feed the molding material forward along the spiral groove of the screw 330. Accordingly, the molding material is gradually melted. When the liquid molding material is fed to the front of the screw 330 and accumulated in the front portion of the cylinder 310, the screw 330 is caused to move backward. A rotation speed of the screw 330 is measured using, for example, a metering motor encoder 341. The metering motor encoder 341 measures the rotation of the metering motor 340 and sends a signal indicating the detection result thereof to the control device 700. A screw speed detector that measures the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a general detector may be used.

In the dosing process, the injection motor 350 may be driven to apply a set back pressure to the screw 330 to limit the sudden backward movement of the screw 330. The back pressure applied to the screw 330 is measured using, for example, the load detector 360. In a case where the screw 330 moves backward to a dosing completion position and a predetermined amount of molding material is accumulated in front of the screw 330, the dosing process is completed.

Positions and rotation speeds of the screw 330 in the dosing process are collectively set as a series of setting conditions. For example, a dosing start position, a speed switching position, and a dosing completion position are set. These positions are arranged in this order from the front to the rear and indicate start points and end points of sections in which the rotation speeds are set. The rotation speed is set for each section. One speed switching position may be set, or multiple speed switching positions may be set. The speed switching position may not be set. Further, a back pressure is set for each section.

In the filling process, the injection motor 350 is driven to cause the screw 330 to move forward at a set moving speed and to fill the cavity spaces 801 formed in the molding unit 800 with the liquid molding material accumulated in front of the screw 330. The position and the moving speed of the screw 330 are measured using, for example, an injection motor encoder 351. The injection motor encoder 351 measures the rotation of the injection motor 350 and sends a signal indicating the detection result thereof to the controller 700. In a case where the position of the screw 330 reaches a set position, switching of the filling process to the pressure holding process (so-called V/P switching) is performed. A position at which V/P switching is performed is also referred to as a V/P switching position. The set movement speed of the screw 330 can be changed depending on the position of the screw 330, a time or the like.

Positions and movement speeds of the screw 330 in the filling process are collectively 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 this order from the back to the front and indicate start points and end points of sections in which the movement speeds are set. The movement speed is set for each section. One movement speed switching position may be set, or multiple movement speed switching positions may be set. The movement speed switching position may not be set.

For each section in which the movement speed of the screw 330 is set, an upper limit of the pressure of the screw 330 is set. The pressure of the screw 330 is measured by the load detector 360. In a case where the pressure of the screw 330 is equal to or lower than a set pressure, the screw 330 moves forward at a set movement speed. On the other hand, in a case where the pressure of the screw 330 exceeds the set pressure, the screw 330 moves forward at a movement speed lower than the set movement speed for the purpose of protecting the mold, so that the pressure of the screw 330 is equal to or lower than the set pressure.

After the position of the screw 330 has reached the V/P switching position in the filling process, the screw 330 may be caused to temporarily stop at the V/P switching position and the V/P switching may then be performed. Immediately before the V/P switching, instead of the screw 330 being stopped, the screw 330 may move forward at a very low speed or at a very low speed. Further, a screw position detector for measuring the position of the screw 330 and a screw movement speed detector for measuring the movement speed of the screw 330 are not limited to the injection motor encoder 351, and general detectors may be used.

In the pressure holding process, the injection motor 350 is driven to push the screw 330 forward to maintain the pressure of the molding material at a front end portion of the screw 330 (hereinafter also referred to as a “holding pressure”) at a set pressure, and to push a molding material remaining in the cylinder 310 toward the molding unit 800. An insufficient amount of the molding material due to cooling shrinkage inside the molding unit 800 may be replenished. The holding pressure is measured using, for example, the load detector 360. A set value of the holding pressure may be changed depending on a time elapsed since the start of the pressure holding process or the like. A plurality of holding pressures and a plurality of holding times at which the holding pressure is held in the pressure holding process may be set, and may be collectively set as a set of setting conditions.

The molding material filled in the cavity spaces 801 formed in the molding unit 800 is gradually cooled in the pressure holding process, and an inlet of the cavity spaces 801 is closed by the solidified molding material at the completion time of the pressure holding process. This state is called a gate seal, and the backflow of the molding material from the cavity spaces 801 is prevented. A cooling process is started after the pressure holding process. The molding material in the cavity spaces 801 is solidified in the cooling process. The metering process may be performed in the cooling process for the purpose of shortening a molding cycle time.

The injection unit 300 of the present embodiment is of an in-line screw type, but may be of a pre-plasticizing type or the like. An injection unit of the pre-plasticizing type supplies a molding material melted in a plasticizing cylinder to an injection cylinder and injects the molding material from the injection cylinder into a molding unit. In the plasticizing cylinder, a screw is arranged so as to be rotatable and incapable of moving back and forth, or a screw is arranged in the plasticizing cylinder so as to be rotatable and capable of moving back and forth. Meanwhile, a plunger is arranged in the injection cylinder so as to be capable of moving back and forth.

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

(movement unit)

In the description of the moving unit 400, as in the description of the injection unit 300, the moving direction of the screw 330 during filling (for example, the negative X-axis direction) corresponds to a front side, and the moving direction of the screw 330 during dosing (for example, the positive X-axis direction) corresponds to a back side.

The moving unit 400 causes the injection unit 300 to move back and forth with respect to the molding unit 800. Further, the moving unit 400 presses the nozzle 320 against the molding unit 800 to generate a nozzle contact pressure. The moving unit 400 includes a hydraulic pump 410, a motor 420 as a drive source, a hydraulic cylinder 430 as a hydraulic actuator, and the like.

The hydraulic pump 410 includes a first port 411 and a second port 412. The hydraulic pump 410 is a pump that can be rotated in both directions and sucks hydraulic fluid (for example, oil) from one of the first port 411 and the second port 412 and discharges the hydraulic fluid from the other thereof to generate hydraulic pressure in a case where a rotation direction of the motor 420 is changed. The hydraulic pump 410 can also suck hydraulic fluid from a tank and discharge the hydraulic fluid from the first port 411 or the second port 412.

The motor 420 causes the hydraulic pump 410 to operate. The motor 420 drives the hydraulic pump 410 in a rotational direction corresponding to a control signal sent from the controller 700 with torque corresponding to the control signal. The motor 420 may be an electric motor or may be an electric servomotor.

The hydraulic cylinder 430 includes a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection unit 300. The piston 432 divides the interior of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. The piston rod 433 is fixed to the stationary plate 110.

The front chamber 435 of the hydraulic cylinder 430 is connected to the first port 411 of the hydraulic pump 410 via a first flow channel 401. In a case where hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow channel 401, the injection unit 300 is pushed forward. The injection unit 300 moves forward so that the nozzle 320 is pressed against the stationary mold 810. The front chamber 435 functions as a pressure chamber that generates the nozzle contact pressure of the nozzle 320 with the pressure of the hydraulic fluid discharged from the hydraulic pump 410.

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via a second flow channel 402. In a case where hydraulic fluid discharged from the second port 412 is supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow channel 402, the injection unit 300 is pushed backward. The injection unit 300 moves backward so that the nozzle 320 is separated from the stationary mold 810.

The moving unit 400 includes the hydraulic cylinder 430 in the present embodiment, but the present invention is not limited thereto. For example, an electric motor and a motion converting mechanism that converts a rotational motion of the electric motor into a linear motion of the injection unit 300 may be used instead of the hydraulic cylinder 430.

(Control device)

The control device 700 is formed of, for example, a computer and includes a central processing unit (CPU) 701, a storage medium 702 such as a memory, an input interface 703, an output interface 704 and a communication interface 705 as shown in 1 and 2 . The control device 700 causes the CPU 701 to execute a program stored in the storage medium 702 to perform various types of control. Further, the control device 700 receives a signal from the outside via the input interface 703 and transmits a signal to the outside via the output interface 704.

The control device 700 repeatedly performs the metering process, the mold closing process, the pressurizing process, the mold closing/clamping process, the filling process, the pressure holding process, the cooling process, the pressure releasing process, the mold opening process, the ejection process, and the like to repeatedly produce molded products. A series of operations for obtaining molded products, for example, operations from the start of one metering process to the start of the next metering process, is also referred to as a "shot" or a "molding cycle." Further, a time required for one shot is also referred to as a "molding cycle time" or a "cycle time."

For example, a molding cycle includes the metering process, the mold closing process, the pressurizing process, the mold closing/clamping process, the filling process, the pressure holding process, the cooling process, the pressure releasing process, the mold opening process, and the ejection process in this order. The order mentioned here is an order in which the respective processes are started. The filling process, the pressure holding process, and the cooling process are performed during the mold closing/clamping process. The start of the mold closing/clamping process may coincide with the start of the filling process. The completion of the pressure releasing process coincides with the start of the mold opening process.

Multiple processes may be performed simultaneously for the purpose of shortening a mold cycle time. For example, a metering process may be performed during a cooling process of a previous mold cycle, or it may be performed during a mold closing/clamping process. In this case, the mold closing process may be performed at the beginning of the mold cycle. Further, the filling process may be started during the mold closing process. Further, the ejection process may be started during the mold opening process. In a case where an on-off valve for opening and closing a flow channel of the nozzle 320 is provided, the mold opening process may be started during the metering process. This is because a molding material does not leak from the nozzle 320 as long as the on-off valve closes the flow channel of the nozzle 320 even if the mold opening process is started during the metering process.

A molding cycle can include other processes than the dosing process, the mold closing process, the pressurization process, the mold closing/clamping process, the filling process, the pressure holding process, the cooling process, the pressure releasing process, the mold opening process and the ejection process.

For example, after the completion of the pressure holding process, a pre-dosing suction process for causing the screw 330 to move backward to a preset dosing start position may be performed before the start of the dosing process. Since the pressure of the molding material accumulated in front of the screw 330 can be reduced before the start of the dosing process, the sudden backward movement of the screw 330 at the start time of the dosing process can be prevented.

Furthermore, after the completion of the metering process, a post-metering suck-back process for causing the screw 330 to move backward to a preset filling start position (also referred to as an "injection start position") may be performed before the start of the filling process. Since the pressure of the molding material accumulated in front of the screw 330 can be reduced before the start of the filling process, the leakage of the molding material from the nozzle 320 before the start of the filling process can be prevented.

The control device 700 is connected to an operation unit 750 that receives an input operation performed by a user and a display unit 760 that displays a screen. The operation unit 750 and the display unit 760 may be formed of, for example, a touch panel 770 and may be integrated with each other. The touch panel 770 as the display unit 760 displays a screen under the control of the control device 700. On the screen of the touch panel 770, for example, information such as the settings of the injection molding machine 10 and the current state of the injection molding machine 10 is displayed. The touch panel 770 can receive an operation in the displayed screen area. Further, on the screen area of the touch panel 770, for example, operation sections such as buttons or input fields used to receive an input operation performed by a user can be displayed. The touch panel 770 as the operation unit 750 detects an input operation performed by a user on the screen and outputs a signal corresponding to the input operation to the control device 700. Accordingly, for example, a user can operate the operation section provided on the screen to adjust the injection molding machine 10 (including input of a setting value) while checking information displayed on the screen. Further, a user can operate the operation section provided on the screen to cause the operation of the injection molding machine 10 corresponding to the operation section to be performed. The operation of the injection molding machine 10 can be, for example, the operation (including stopping) of the mold closing/clamping unit 100, the ejector unit 200, the injection unit 300, the moving unit 400, or the like. Further, the operation of the injection molding machine 10 can be switching the screen displayed on the touch panel 770 as the display unit 760 or the like.

The operation unit 750 and the display unit 760 of the present embodiment have been described as being integrated with the touch panel 770, but they may be provided independently of each other. Further, a plurality of operation units 750 may be provided. The operation unit 750 and the display unit 760 are arranged on an operation side (negative Y-axis direction) of the mold closing/clamping unit 100 (more specifically, the stationary platen 110).

(First embodiment)

3 is a diagram showing components of the control device 700 of the injection molding machine 10 according to the embodiment as functional blocks. The respective 3 are conceptual and may not necessarily be physically configured as shown. All or a portion of the respective functional blocks may be functionally or physically distributed and integrated as any unit. All or any portion of any processing function performed by each functional block is realized by a program executed by the CPU 701. Alternatively, each functional block may be realized as hardware using wired logic. As shown in 3 As shown, the CPU 701 of the control device 700 includes a setting unit 711, a detection unit 712, a determination unit 713, a log control unit 714, and a display control unit 715. Further, the control device 700 includes a log storage section 721 in the storage medium 702.

The log storage section 721 stores log information about the injection molding machine 10. For example, the log information is information about the setting and an actual result of injection molding whenever injection molding is performed by the injection molding machine 10. Specific log information will be described later.

Next, a method used by the control device 700 according to the present embodiment to monitor gas combustion will be described.

4 is a diagram showing a molding material M flowing into the molding unit 800 according to the present embodiment and a sensor 841 provided in the molding unit 800.

This in 4 For example, the molding material M shown is a resin. The molding material M flows into the cavity space 801 formed in the molding unit 800. The cavity space 801 is formed at a parting surface 830 between the stationary mold 810 and the movable mold 820. The parting surface 830 is generally referred to as a parting line.

In a case where the molding material M flows into the cavity space 801, gas in the cavity space 801 escapes to the outside of the mold unit 800 via the parting surface 830 and the like as shown by an arrow. Accordingly, the entire cavity space 801 is filled with the molding material M.

The sensor (an example of a detection unit) 841 is provided near an end of a flow path represented by the cavity space 801 in the cavity space 801 formed in the mold unit 800 of the injection molding machine 10. That is, the end of the flow path means an end portion to which the molding material to be filled in the cavity space 801 comes. In the present embodiment, the sensor 841 may be arranged near the end of the flow path, and may not necessarily be arranged at a finally filled portion. That is, the sensor 841 only needs to be capable of detecting a state of the end of the flow path of the mold unit 800.

The sensor 841 detects at least a pressure in the mold unit 800. Moreover, the sensor 841 detects at least one or more temperatures in the mold unit 800 and a distance to a front end portion (flow front) of the flowing molding material M. As described above, the sensor 841 includes, for example, a pressure sensor. The sensor 841 may include only a pressure sensor, or may include at least one of a temperature sensor and a distance sensor (for example, a laser sensor). Moreover, at least one or more of the situations of gas in the cavity space 801 and the situation of the flow of the molding material M in the cavity space 801 can be estimated from a detection result of the sensor 841.

The pressure sensor as the sensor 841 detects the pressure of gas or the molding material M adjacent to the sensor 841.

The temperature sensor as the sensor 841 detects the temperature of gas or the molding material M adjacent to the sensor 841.

The distance sensor as the sensor 841 detects a distance to a flow front end portion of the molding material M from the position of the sensor 841.

5(A) to 5(D) are diagrams showing a change in the flow of the molding material M in the molding unit 800 according to the present embodiment. In a 5(A) In the situation shown, the molding material M flows along an arrow 1511 due to the filling process. Then, in a case where the position of the screw 330 reaches a set position, the V/P switching of the filling process to the pressure holding process is performed.

In a 5(B) In the situation shown, the screw 330 moves backward at a very low speed as shown by an arrow 1521 after the U/P switching is performed. The molding material M flows in a direction indicated by an arrow 1522 due to pressure relief.

In a 5(C) In the following situation shown, in the pressure holding process, the injection motor 350 is driven to push the screw 330 forward to maintain the pressure of the molding material at a front end portion of the screw 330 (hereinafter also referred to as a "holding pressure") at a set pressure, and to push a molding material remaining in the cylinder 310 toward the molding unit 800. Accordingly, the molding material M is moved in a direction indicated by an arrow 1523.

In a 5(D) In the following situation shown, the molding material M is moved in a direction indicated by an arrow 1524 in the pressure holding process so that gas is discharged and a state is reached in which the cavity space 801 is filled with the molding material M up to the end of the flow path (so-called packed state).

A control system that is compatible with the 5(A) to 5(D) shown movement of the molding material is an example and is not limited to the control mentioned above. For example, a time when the filling process is switched to the pressure holding process is an example and may be a time when, for example, a state is switched to the packed state, or the filling process can be switched to the pressure holding process after a state is switched to the packed state. In addition, pressure holding can be performed during the filling process.

6 is a graph showing changes in temperature and pressure from the start of filling to the pressure holding. Changes in temperature 1601 and pressure 1602 detected by the sensor 841 are shown in a 6 shown example. In the example shown in 6 In the example shown, the control of the speed of the screw 330 is performed as the filling process. Then, at a time T ₁₁ , so-called V/P switching is performed in which the filling process is switched to the pressure holding process. In a subsequent pressure holding process, the molding material remaining in the cylinder 310 is pressed toward the molding unit 800 in a state in which the holding pressure of the molding material at the front end portion of the screw 330 is maintained at the set pressure.

The pressure 1602 of gas in the cavity space 801, which has been increased due to the filling process, is reduced when some time has passed after the filling process is switched to the pressure holding process.

A state in which the cavity space 801 is filled with the molding material M up to the end of the flow path (so-called packed state) is reached at a time T ₁₂ . That is, as the molding material M is in contact with the sensor 841, the temperature 1601 rises. In other words, a time (inflection point) at which the sensor 841 detects a sharp temperature rise is a time at which the cavity space 801 is filled with the molding material M up to the end of the flow path (the time of packing).

In the present embodiment, in a case where a difference between a temperature detected at a previous time and a temperature detected at this time exceeds 10°, the determination unit 713 determines that it is a time when the cavity space 801 is filled with the molding material M up to the end of the flow path (the time of packing). A determination method based on whether or not a temperature difference according to the present embodiment has exceeded 10° is an example of a determination method at the time of packing. The determination method at the time of packing is not limited to the method described above, and other methods may also be used. Further, a determination condition “10°” according to an embodiment may also be set to an appropriate value. For example, a case where the distance sensor of the sensor 841 determines that a distance to the flow front end portion of the molding material M is “0” and the like may be used as the determination method at the time of packing.

After the packed state is reached at a time T ₁₂ , the sensor 841 further detects the pressure of the molding material (resin pressure). As described above, in a case where the packed state is reached at the time T ₁₂ , the detected pressure is switched from gas pressure to the pressure of the molding material (resin pressure). Accordingly, the detected pressure increases.

Meanwhile, in a case where injection molding is repeated, components of the molding material M are deposited on the parting surface 830 to form mold deposits. In a case where the volume of the mold deposits is increased, it is difficult for gas in the cavity space 801 to be discharged to the outside of the cavity space 801 during filling of the molding material M. As a result, since the temperature of gas remaining in the cavity space 801 rises to a high temperature due to adiabatic compression of the gas, a molded product is burned and becomes a defective product.

That is, in a case where gas combustion occurs, the temperature of the gas rises sharply due to adiabatic expansion of the gas present at the end of the flow path of the molding unit 800 immediately before packing. Along with the temperature, the pressure in the cavity spaces 801 also rises.

In the prior art, a worker refers to a molded product in an inspection process after molding to determine whether gas burning has occurred or not. In a case where the worker determines that gas burning has occurred, the worker determines that it is difficult for gas to escape due to the deposition of the mold deposits, and production of molded products is stopped and the molding unit is cleaned. Since it is not possible to detect whether gas burning has occurred or not before inspecting the molded product in a case where such a method is used, several defective products in which gas burning has occurred are produced.

Accordingly, the control device 700 according to the present embodiment determines, based on the pressure generated by the Sensor 841 is detected, near a time when the packed state is reached, whether gas combustion has occurred in the molded product or not. A determination that gas combustion has occurred according to the present embodiment is not limited to a case where gas combustion has actually occurred, and also includes a state where gas combustion occurs with a high probability. That is, in the present embodiment, in a case where the same pressure as in a case where gas combustion occurs is detected from a correspondence relationship between a pressure detected in the past and gas combustion, a determination that gas combustion has occurred is made regardless of whether gas combustion has actually occurred or not.

7 is a graph showing a pressure change detected by the sensor 841 when the packed state is reached in the mold unit 800 according to the present embodiment. A horizontal axis represents the number of shots (an example of the number of injections) from a time when the mold unit 800 is cleaned, and a vertical axis represents a pressure detected when the packed state is reached (in other words, it is determined that the packed state is reached using a detected temperature). Lines 1701 to 1705 correspond to common injection conditions and the like, except that cleaning conditions and the like are different.

From the 7 From lines 1701 to 1705 shown, it can be confirmed that a pressure at a time when the packed state is reached is gradually increased whenever molded products are produced from a time when cleaning is performed, that is, whenever the number of shots is increased.

In a 7 In the example shown, a pressure with respect to each of the lines 1701 to 1705 sharply increases in the vicinity of the number of shots at which the detected pressure exceeds a threshold value Pth1. The reason for this is that a pressure sharply increases in a case where the temperature of gas rises to a high temperature due to adiabatic compression of the gas, since it is difficult for the gas to be discharged to the outside of the cavity space 801 due to an increase in the volume of the mold deposits, resulting in a large amount of gas accumulating in the cavity space 801. That is, it can be considered that gas combustion occurs in the molded product at a time when the detected pressure exceeds the threshold value Pth1.

With respect to the respective lines 1701 to 1704, the number of shots performed until the detected pressure reaches the threshold value Pth1 varies depending on the cleaning state of the molding unit 800, an environment in which injection molding is performed, or the like. However, the lines 1701 to 1704 are common to each other in that gas combustion occurs in the molded products at a time when the pressure detected by the sensor 841 exceeds the threshold value Pth1. The line 1705 indicates a case where, in a 7 shown range, a pressure at which a state reaches the packed state does not reach the threshold Pth1, and gas combustion has not occurred in the molded product. That is, a case where the detected pressure does not reach the threshold Pth1 even though the number of shots is large means that gas combustion has not occurred in the molded product.

Accordingly, the control device 700 according to the present embodiment determines whether or not gas combustion has occurred based on whether or not a pressure at which the packed state is reached (in other words, it is determined that the packed state is reached using a detected temperature) has exceeded the threshold Pth1. The present embodiment does not limit a timing at which it is determined whether or not gas combustion has occurred to a case where the packed state is reached. However, since the timing of packing substantially coincides with a timing at which gas combustion occurs, it is possible to improve the accuracy of determining whether or not gas combustion has occurred by using a pressure at the timing of packing for determination.

Back to 3 Each component of the control device 700 is described.

The setting unit 711 sets the threshold value Pth1 which is a criterion for determining whether gas combustion has occurred or not. For example, as the threshold value Pth1, a pressure detected by the sensor 841 when gas combustion has occurred while molded products are actually repeatedly produced by the injection molding machine 10 is set. The set threshold value Pth1 may be a value input by a user via the operation unit 750, or it may be automatically set by the control device 700.

The detection unit 712 detects signals (an example of information) indicating detection results from various sensors provided in the injection molding machine 10. For example, the detection unit 712 detects signals indicating detection results based on the pressure and the temperature output from the sensor 841. Accordingly, the detection unit 712 may detect signals indicating a pressure and a temperature from the sensor 841 provided near an end where the molding material to be filled into the cavity space 801 enters the cavity space 801 formed in the molding unit 800 of the injection molding machine 10.

The determination unit 713 determines whether or not the cavity space 801 is filled with the molding material up to a flow end of the molding unit 800 based on the temperature output from the sensor 841 and detected by the detection unit 712. The present embodiment is not limited to a method of detecting a pressure at exactly a time when the cavity space 801 is filled with the molding material up to the flow end of the molding unit 800. That is, a pressure increase that causes gas combustion to occur occurs not only at a time when the cavity space 801 is filled with the molding material but also before and after the time. That is, it is preferable that a time at which a pressure is to be detected is set within, for example, ±0.05 seconds from a time when the cavity space 801 is filled with the molding material to the flow end of the molding unit 800.

Moreover, the determination of whether or not the cavity space 801 is filled with the molding material up to the flow end of the molding unit 800 is not limited to a method using a temperature, and whether or not the cavity space 801 is filled with the molding material may be determined based on a distance to the molding material detected by the sensor 841. For example, it may be determined that the cavity space 801 is filled with the molding material at a time when a distance between the sensor 841 and the molding material is "0".

Then, the determination unit 713 determines whether the pressure detected by the sensor 841 exceeds the threshold value Pth1 set by the setting unit 711 in the vicinity of a time point at which the cavity space 801 is filled with the molding material up to the flow end of the molding unit 800 (the packed state is reached). In a case where the pressure detected by the sensor 841 exceeds the threshold value Pth1 set by the setting unit 711, it is determined that gas combustion has occurred.

In the present embodiment, a timing for determining whether or not gas combustion has occurred is not limited to a timing near the timing at which the cavity space 801 is filled with the molding material to the flow end (the packed state is reached). That is, since gas combustion occurs in a case where it is difficult for gas to be discharged from the molding unit 800, it is possible to determine whether or not gas combustion has occurred in a case where it is possible to detect that it is difficult for gas to be discharged from the molding unit 800. For example, the determination unit 713 may determine that gas combustion has occurred in a case where the pressure detected by the sensor 841 near the timing of V/P switching exceeds a threshold value Pth2. A determination that gas combustion has occurred according to the present embodiment is not limited to a case where gas combustion has actually occurred, and also includes a state where gas combustion is highly likely to occur.

8th is a graph showing a pressure change detected by the sensor 841 at the time of V/P switching in the mold unit 800 according to the present embodiment. A horizontal axis represents the number of shots from a time when the mold unit 800 is cleaned, and a vertical axis represents a pressure detected at the time of V/P switching.

With regard to lines 1801 and 1802, which are in 8th , it can be confirmed that a pressure at the time of V/P switching is gradually increased whenever molded products are produced from a time when cleaning is performed, that is, whenever the number of shots is increased. The lines 1801 and 1802 indicate cases where the molding conditions (for example, the construction of the screw 330 and the like) are different from each other.

Then, the determination unit 713 may determine whether or not a pressure detected by the sensor 841 at the time of V/P switching exceeds the threshold value Pth2. Thereafter, the determination unit 713 may determine that gas combustion has occurred in a case where the pressure detected by the sensor 841 at the time of V/P switching exceeds the threshold value Pth2. The present embodiment is not limited to a method of detecting a pressure precisely at the time of V/P switching. It is preferable that a time at which a pressure is to be detected is set within, for example, ±0.05 seconds from the time of V/P switching.

The log control unit 714 performs control for storing the log information of the injection molding machine 10 in the log storage section 721. For example, in a case where the determination unit 713 determines that it is the timing of packing, the log control unit 714 may include the pressure detected by the sensor 841 in the log information and store the log information in the log storage section 721.

For example, the log control unit 714 stores actual result values during molding, setting information, calculated statistics, and the like in the log storage section 721 as the log information. Setting for storing the actual result values during molding, the setting information, the calculated statistics, and the like as the log information is performed on a log information screen displayed by the display control unit 715.

Further, in a case where it is determined whether or not gas combustion has occurred using the pressure detected by the sensor 841 at the time of V/P switching, the log control unit 714 may include the pressure detected by the sensor 841 in the log information, and store the log information in the log storage section 721 in a case where it is determined that it is the time of V/P switching.

The display control unit 715 performs control to display data such as a display screen on the display unit 760.

The display control unit 715 according to the present embodiment may output to the display unit 760 a display screen that includes setting information set by a user in each process of molding performed by the injection molding machine 10 or current result values detected in the process. In the present embodiment, an example in which a display screen and the like are output to the display unit 760 is described, but a destination to which data is to be output is not limited to the display unit 760. For example, the display control unit 715 may output data such as a display screen to a communication terminal connected via a network.

The display control unit 715 according to the present embodiment displays a log information screen that displays, for example, current result values during forms, setting information, statistics, and the like as the log information.

9 is a diagram illustrating the log information screen output from the display control unit 715 according to the present embodiment.

A total number 1401, a number of non-defective products 1402, a number of defective products 1403, a number of rejects 1404, a logging button 1405, a monitoring setting button 1406, a storage button 1407, and an update button 1408, a statistical list 1420 and an actual result list 1430 are displayed on the display shown in 9 The protocol information screen 1400 shown is displayed.

Statistics (e.g., an average, a range, the maximum, the minimum, and a standard deviation) of each of the setting fields 1421 to 1428 are displayed in the statistical list 1420. Contents displayed in the setting fields 1421 to 1428 may be set by a user. In the present embodiment, items displayed in the setting fields 1421 to 1428 may be displayed and monitored, and log information about the items may be stored. The monitoring of the present embodiment represents the determination based on a predetermined criterion as to whether or not a product is a non-defective product.

“Monitoring,” an “upper limit,” and a “lower limit” of the 1420 statistical list are information used to determine whether molded products conforming to the setting fields are defective or not.

In a case where the monitoring of the statistical list 1420 is “OFF”, the control device 700 does not perform monitoring. In a case where the monitoring of the statistical list 1420 is “ON”, the control device 700 performs monitoring. In a case where the monitoring of the statistical list 1420 is “ON”, the control device 700 determines whether measured actual result values of the items displayed in the setting fields satisfy criteria indicated by the “upper limit” and the “lower limit”. The monitoring is performed using using the monitoring setting button 1406.

“Defective” of the statistical list 1420 represents the number of molded products that are not included in a range specified by the “upper limit” and the “lower limit”.

Settings or current result values related to injection molding are set in setting fields 1421 to 1428. Setting fields 1421 to 1428 can be changed to items that a user wants to monitor. The description of a change method is omitted.

The actual result list 1430 shows a list of setting information about the items set in the setting fields 1421 to 1428 or actual result values measured by various sensors for each shot. The items set in the setting fields 1421 to 1428 are set to "CH-1" to "CH-8". Further, a "shot number", a "time" at which injection molding is performed, and the "state" of injection molding are linked as information indicating the shot for each shot.

The logging button 1405 is a button used for accepting whether or not to store at least one or more of a setting value and an actual result value shown in the actual result list 1430 as the logging information. In a case where the logging button 1405 is pressed ("logging ON" is displayed), the logging control unit 714 stores the information and the like shown in the actual result list 1430 in the logging storage section 721 as the logging information.

The monitoring setting button 1406 is a button used for accepting whether or not to perform monitoring according to the items to be monitored in the statistical list 1420. In a case where the monitoring setting button 1406 is pressed ("Monitoring ON" is displayed), whether a molded product is a defective product or not is monitored for each shot, and a monitoring result is included in the log information. The monitoring of the statistical list 1420 is switched to "OFF" or "ON" depending on whether the monitoring setting button 1406 is pressed or not.

In a case where the monitoring of the statistical list 1420 is set to “ON” by the monitoring setting button 1406, monitoring is performed according to the setting of the “monitoring” of the above-mentioned statistical list 1420.

For example, a "pressure at the time of packing" in the setting field 1428 is an item in which an actual result value of the pressure detected by the sensor 841 at the time of packing is set. In the present embodiment, "ON" is set in a "monitor" field 1629 with respect to the "pressure at the time of packing". In an upper limit field 1629A, for example, "20.00" (MPa) is set as the threshold value Pth1. Accordingly, in a case where the determination unit 713 determines that the pressure at the time of packing is higher than "20.00" (an example of the threshold value Pth1), the number of defective products 1403 is increased.

In the present embodiment, an example of the threshold value Pth1 is shown and is not limited to "20.00". The threshold value Pth1 varies depending on, for example, the shape of the molding unit 800, the type of the molding material, or the like.

The storage button 1407 is a button used for accepting whether or not to store the statistics (for example, an average, a range, the maximum, the minimum, an integrated value, and a standard deviation) of each of the setting fields 1421 to 1428. In a case where the storage button 1407 is pressed, the log control unit 714 stores the statistics of each of the setting fields 1421 to 1428 in the log storage section 721 as the log information.

The update button 1408 is a button used to assume whether or not to update the statistical list 1420 and the actual result list 1430 whenever the injection molding performed by the injection molding machine 10 is completed. In a case where the update button 1408 is pressed (displayed as “Always”), the statistical list 1420 and the actual result list 1430 are updated whenever the injection molding performed by the injection molding machine 10 is completed.

The total number 1401 indicates the number of molded products molded by the injection molding machine 10. The number of non-defective products 1402 indicates the number of molded products determined as non-defective products based on the “monitoring”, the “upper limit” and the “lower limit”. The number of defective products 1403 indicates the number of molded products products determined as defective products based on the "monitoring", "upper limit" and "lower limit". The number of rejects 1404 indicates the number of molded products rejected.

The display control unit 715 according to the present embodiment displays "20.00" (MPa) in the upper limit field 1629A and displays a transition of a pressure detected at the time of packing in the actual result list 1430 on the log information screen of the display unit 760. Accordingly, a user can recognize whether or not gas combustion has occurred in a molded product produced by the injection molding machine 10.

In the present embodiment, a screen displayed by the display control unit 715 is not limited to the log information screen. For example, the display control unit 715 may display a diagram shown in 7 and which shows the transition of a pressure at the time of packing with respect to the number of shots. The threshold value Pth1 may be shown as a line in the diagram.

As another example, the display control unit 715 may display a diagram that is 8th and which shows a transition of a pressure at the time of V/P switching with respect to the number of shots. The threshold value Pth2 may be indicated as a line in the diagram.

As a modification example, the determination unit 713 may not make a determination, and the display control unit 715 may only display the 7 or 8th A user can refer to the diagram shown in 7 or 8th Refer to the diagram shown to determine the number of shots until gas combustion occurred and whether or not gas combustion occurred.

Furthermore, in the present embodiment, in a case where the determination unit 713 determines that the pressure detected by the sensor 841 exceeds the threshold value Pth1 at a time when the packed state is reached, the display control unit 715 displays a screen showing that "gas combustion has occurred in a molded product" on the log information screen 1400. The screen to be displayed is, for example, a pop-up screen.

Accordingly, a user can recognize that gas combustion has occurred. Information output in a case where it is determined that the pressure detected by the sensor 841 exceeds the threshold value Pth1 at a time when the packed state is reached is not limited to the display screen. For example, the control device 700 may output with a voice that gas combustion has occurred, or may notify a communication terminal connected via a network that gas combustion has occurred.

Next, a processing method until gas combustion is detected in the injection molding machine 10 according to the present embodiment will be described. 10 is a flowchart showing a processing procedure until gas combustion is detected in the injection molding machine 10 according to the present embodiment.

First, the injection molding machine 10 repeats the production of a molded product until gas combustion occurs (S2001). When gas combustion occurs, the controller 700 detects a pressure detected by the sensor 841 at the time of packing.

Then, the setting unit 711 of the control device 700 sets the pressure detected when gas combustion occurs as the threshold value Pth1 (S2002).

Thereafter, the injection molding machine 10 starts to produce a molded product under control performed by the control device 700 (S2003).

Then, the detection unit 712 detects the pressure detected by the sensor 841 at the time of packing (S2004). As described above, the determination unit 713 specifies the time of packing based on the temperature detected by the sensor 841.

Thereafter, the determination unit 713 determines whether or not the detected pressure has exceeded the set threshold Pth1 (S2005). In a case where the determination unit 713 determines that the detected pressure has not exceeded the set threshold Pth1 (NO at S2005), the injection molding machine 10 performs the processing of S2004 again to produce the next molded product.

On the other hand, in a case where the determination unit 713 determines that the detected pressure has exceeded the threshold value Pth1 (YES at S2005), the display control unit 715 displays a pop-up screen showing that gas combustion has occurred, and the control device tung 700 emits a notification tone (S2006).

In the present embodiment, the above-mentioned control enables a user to recognize that gas combustion has occurred.

(Modification example of first embodiment)

An example in which it is determined whether or not gas combustion has occurred based on a pressure detected near the time of packing or the time of V/P switching has been described in the present embodiment. However, the present embodiment is not limited to determining whether or not gas combustion has occurred based on whether a pressure equal to or higher than the threshold value is detected. Accordingly, in a modification example, it is determined whether or not gas combustion has occurred based on a difference in detected pressure.

As in 7 As shown, a pressure at the time of packing increases sharply when gas combustion occurs. That is, it can be assumed that gas combustion has occurred in a case where a pressure detected at that time is higher than pressures detected at the time of packing up to the present.

For this reason, the determination unit 713 according to the present modification example determines whether or not a difference between a pressure detected at the time of the previous packing and a pressure detected at the time of the present packing is larger than a predetermined value. The predetermined value is set to a value of, for example, 1 to 1.5 MPa. The predetermined value is a value set depending on the embodiment, and is not limited to a range of 1 to 1.5 MPa.

An example in which it is determined whether or not gas combustion has occurred based on a difference between pressures corresponding to two consecutive times among pressures detected at the time of packing has been described in the present modification example. However, in the present modification example, the determination is not limited to a determination based on a difference between pressures detected at two consecutive times, but may also be based on pressures detected at three or more times. Moreover, the determination is not limited to a determination based on a difference between pressures, but may also be a determination using a moving average. Whether or not gas combustion has occurred may be determined based on a moving average of pressures detected at three times, for example. That is, the determination unit 713 may determine whether or not gas combustion has occurred based on a difference between a moving average calculated at this time and a moving average calculated at a previous time.

Furthermore, in the present modification example, whether or not gas combustion has occurred may not be determined based on a difference between a plurality of consecutive pressures detected near the time of packing or near the time of V/P switching, and whether or not gas combustion has occurred may be determined based on, for example, a difference between pressures (in other words, a difference between a plurality of non-consecutive pressures) detected every other time near the time of packing or near the time of V/P switching.

That is, in a case where a difference is detected between pressures near the timing of packing or near the timing of V/P switching between first injection molding and second injection molding performed after the first injection molding satisfies a predetermined condition, the determination unit 713 may determine that gas combustion has occurred in a molded product produced in the second injection molding.

An example in which whether or not gas combustion has occurred is determined based on whether or not a pressure exceeds the threshold value has been described in the above-mentioned embodiment, and an example in which whether or not gas combustion has occurred is determined based on whether or not a difference between pressures is larger than a predetermined value has been described in the modification example. In the above-described embodiment and the modification example, however, a method of determining whether or not gas combustion has occurred is not limited to the above-mentioned methods. That is, it is sufficient to determine whether or not gas combustion has occurred in a molded product based on a preset condition with respect to a pressure detected by the sensor 841. That is, it is It is preferable that a determination based on a predetermined condition relating to the pressure of the flow of the molding material with which the cavity space 801 is filled is used for adjustment.

In the embodiment and the modification example described above, a worker can immediately detect gas combustion without inspecting a molded product. Accordingly, it is possible to prevent a situation in which molded products continue to be produced in a state in which gas combustion has occurred.

(Second embodiment)

An example of determining whether or not gas combustion has occurred has been described in the above-mentioned embodiment. However, the second embodiment is not limited to determining whether or not gas combustion has occurred based on the pressure detected near the time of packing or near the time of V/P switching as in the embodiment and the modification example described above. That is, a period until the occurrence of gas combustion may be estimated based on a pressure change detected near the time of packing or near the time of V/P switching.

The period until the occurrence of gas combustion indicates how long it takes until the occurrence of gas combustion, and is one or more of the number of times (for example, the number of shots, the number of times molding is performed, the number of times production is performed (the number of productions), or the like) and a time (for example, an operation time, a molding time, a production time, or the like). The period until the occurrence of gas combustion is not limited to the number of times or a time indicated by a numerical value or a character string, and can be represented by a drawing or the like. An example in which the number of shots and a time (for example, an operation time) are estimated is described as an example of estimation of a period.

In the prior art, the production of molded products in an injection molding machine is repeated according to a predetermined cycle. Examples of the predetermined cycle include production, the gas combustion of a molded product, and the cleaning of a molding unit. In a case where such a cycle is repeated, the number of shots until the occurrence of the gas combustion of a molded product can be identified. For example, gas combustion occurs in 10,000 shots in a first production, gas combustion occurs in 6,000 shots in a second production, and gas combustion occurs in 13,000 shots in a third production.

That is, the number of shots until gas combustion occurs is changed depending on many factors such as the lot of a molding material (a minute difference in components), the content of moisture contained in the molding material, the state of a mating surface between the stationary mold and the movable mold, the surface state of a pipe molding unit, the degree of cleaning of the molding unit, the degree of generation of gas from the molding material (the variation of plasticization), the temperature of the molding unit, the dimensions of the molding unit, and a mold closing/clamping force.

Accordingly, in the above-mentioned method in the prior art, it is conceivable to stop production at a predetermined number of shots in a fourth and subsequent production so that gas burning does not occur. In this case, in a case where the number of shots is set so that gas burning does not occur, the number of shots is set to, for example, 5000 shots. That is, it is possible to suppress the occurrence of gas burning by cleaning the mold unit after 5000 shots have been completed. However, in a case where the mold unit is to be cleaned at 5000 shots, production must be stopped. In this case, although there is a possibility that production can actually be carried out up to 13000 shots without the occurrence of gas burning, production is stopped at 5000 shots. For this reason, a burden caused by cleaning the mold unit is increased and production efficiency is likely to be reduced.

Accordingly, a protocol control unit 714 according to the present embodiment estimates a time until gas combustion occurs based on a pressure change detected by the sensor 841 near the time of V/P switching or near the time of packing. That is, the protocol control unit 714 calculates the number of shots and a time until a condition under which gas combustion occurs is satisfied based on a change between a pressure detected near the time of V/P switching or near the time of packing in the first injection molding and a pressure detected near the time of V/P switching or near the timing of packing in the second injection molding performed after the first injection molding. Then, a display control unit 715 displays the number of shots and the time (an example of a period) that are calculated.

In the present embodiment, an example in which the estimated number of shots and the estimated time until gas combustion occurs is displayed has been described, but one or more of the number of shots and the time may be displayed. In the present embodiment, an aspect in which the number of shots and a time are displayed as a period until gas combustion occurs in a molded product has been described. However, an output method is not limited to display, but may also be voice output or transmission to a communication terminal.

That is, in a case where gas combustion occurs, a pressure equal to or higher than the above-mentioned threshold is generated near the time of V/P switching or near the time of packing, as shown in 7 and 8th of the first embodiment. Accordingly, in the present embodiment, the protocol control unit 714 estimates the number of shots required until a pressure exceeds the threshold based on the degree of pressure change detected near the timing of V/P switching or near the timing of packing.

The protocol control unit 714 according to the present embodiment calculates an approximate expression indicating a correspondence relationship between the number of shots and a detected pressure based on values of a plurality of pressures detected by the sensor 841 at the time of packing. For the calculation of the approximate expression, a pressure from the start of cleaning to the present may be used, or a pressure corresponding to predetermined shots (for example, several tens of shots) to the present may be used. The approximate expression may be a linear expression, or may be a quadratic expression, a cubic expression, or the like.

For example, in the 7 shown example, a rate of increase of the detected pressure increases as the detected pressure approaches the threshold value Pth1. For this reason, in a case where a pressure from the start of cleaning to the present is used to calculate an approximate expression, it is preferable that the approximate expression is a quadratic expression or a cubic expression. On the other hand, in a case where a linear expression is used as an approximate expression, it is preferable that a pressure corresponding to predetermined shots (for example, a pressure corresponding to several tens of shots) to the present is used.

Further, the protocol control unit 714 is not limited to a method of calculating an approximate expression indicating the pressure detected by the sensor 841 at the time of packing, and may calculate an approximate expression indicating a correspondence relationship between the number of shots and a pressure based on the pressure detected by the sensor 841 at the time of V/P switching.

In the 8th In the example shown in Fig. 1, it can be confirmed in examples shown by lines 1801 and 1802 that a pressure at the time of V/P switching is gradually increased whenever molded products are produced from a time when cleaning is performed, that is, when the number of shots is increased.

Accordingly, in a case where a pressure change shown by the line 1801 is detected, the protocol control unit 714 calculates an approximate expression “y = a1 x + b1” shown by a line 1811. In a case where the number of shots is denoted by x and a pressure is denoted by y, variables a1 and b1 are assigned based on a pressure change shown by the line 1801.

Further, in a case where a pressure change shown by the line 1802 is detected, the protocol control unit 714 calculates an approximate expression "y = a2 x + b2" shown by a line 1812. In a case where the number of shots is denoted by x and a pressure is denoted by y, variables a2 and b2 are assigned based on a pressure change shown by the line 1802.

That is, in the 8th In the example shown, in a case where the approximate expression is calculated and y of the approximate expression is then replaced by the threshold value Pth2, the protocol control unit 714 can derive the number of shots x at which gas combustion is predicted to occur. Further, from the number of shots x at which gas combustion is predicted to occur and a time required for each shot, the protocol control unit 714 can derive a time until gas combustion occurs. combustion. The calculated method can be applied not only at the time of V/P switching, but also at the time of packing described above.

A case where the approximate expression is a linear expression was considered in the 8th example shown, but the same calculation procedure can also be used in the case of a quadratic expression or a cubic expression.

The number of shots and the time until gas combustion occurs, which are calculated by the protocol control unit 714, are displayed by the display control unit 715.

11 is a diagram illustrating the gas combustion prediction information screen output from the display control unit 715 according to the present embodiment.

Pack detection 2101, a pressure at the time of gas combustion 2102, an estimated number of shots until gas combustion 2103, an estimated time until gas combustion 2104, a gas combustion prediction alarm 2105, and an alarm notification setting 2106 are shown on a gas combustion prediction information screen 2100 which is in 11 is shown.

In the packing detection 2101, it is set whether or not to detect the timing of packing. For example, the packing detection 2101 is set according to an input from the operation unit 750. "Automatic" and "OFF" can be switched in the packing detection 2101. In a case where "automatic" is set in the packing detection 2101, the determination unit 713 detects the above-mentioned timing of packing.

A pressure (threshold) at which gas combustion is detected is set in the pressure at the time of gas combustion 2102. For example, the pressure at the time of gas combustion 2102 is set according to an input from the operation unit 750. In the present embodiment, in a case where a pressure is set, the determination unit 713 determines whether or not gas combustion has occurred based on the pressure (threshold), and the protocol control unit 714 calculates the number of shots and a time until the occurrence of gas combustion based on the set pressure (threshold).

The number of shots until gas burn occurs, calculated by the protocol control unit 714, is displayed in the estimated number of shots until gas burn 2103.

A time until gas combustion occurs, which is calculated by the protocol control unit 714, is displayed in the estimated time until gas combustion 2104.

In the gas combustion prediction alarm 2105, whether or not to issue an alarm before the occurrence of gas combustion is set. For example, the gas combustion prediction alarm 2105 is set according to an input from the operation unit 750. "ON" and "OFF" can be switched in the gas combustion prediction alarm 2105. In a case where "ON" is set in the gas combustion prediction alarm 2105, the control device 700 issues an alarm indicating that gas combustion is approaching before the occurrence of gas combustion.

A timing at which an alarm notification is sent is set in the alarm notification setting 2106. For example, the alarm notification setting 2106 is set according to an input from the operation unit 750. In the present embodiment, an alarm is issued at a timing preceding the number of shots at which gas combustion is predicted to occur by a number set in the alarm notification setting 2106.

For example, in a case where "1000" is set in the estimated number of shots until gas combustion and "10" is set in the alarm notification setting 2106, an alarm is issued at a time when the number of shots is "990". The alarm may be a voice, a display of a pop-up screen, or a notification to a communication terminal.

Furthermore, the gas combustion prediction information screen output from the display control unit 715 is not limited to the 11 shown screen, but may also have another aspect. For example, the display control unit 715 may display a diagram plotting values of pressures detected by the sensor 841 and showing a transition of a pressure up to the present, as shown in 7 or 8th A threshold value used to determine whether gas combustion has occurred or not can be superimposed on such a diagram and displayed In addition, the prediction of a transition of a pressure until the pressure reaches the threshold can be shown based on the transition of the pressure up to the present. The prediction of the transition of a pressure can be calculated by any well-known method. For example, the approximate expressions mentioned above, which are given in 8th A worker according to the present embodiment can perform work in consideration of the display of the estimation of a period until the occurrence of gas combustion.

In the present embodiment, since an alarm notification is sent before the occurrence of gas combustion, the worker can initiate processes to resolve the gas combustion before the gas combustion occurs.

Next, a processing method of the control device 700 according to the present embodiment until the output of an alarm will be described. 12 is a flowchart showing a processing procedure of the control device 700 according to the present embodiment until the output of an alarm.

The setting unit 711 of the control device 700 sets a pressure at the time of packing, which is detected when gas combustion occurs, as a threshold value Pth1 (S2201).

Thereafter, the injection molding machine 10 starts to produce a molded product under control performed by the control device 700 (S2202).

Then, the detection unit 712 detects the pressure detected by the sensor 841 at the time of packing (S2203). As in the above-mentioned embodiment, the determination unit 713 specifies the time of packing based on a temperature detected by the sensor 841.

The protocol control unit 714 estimates (calculates) the number of shots and a time until a pressure exceeds the threshold based on pressures at the time of packing detected up to the present (S2204).

The display control unit 715 displays the number of shots and the time, which are estimation results, on the gas combustion prediction information screen (S2205).

In addition, the determination unit 713 determines whether or not the number of shots until a pressure exceeds the threshold is equal to or less than the number of shots set in the alarm notification setting 2106 (S2206) from the current number of shots. In a case where the determination unit 713 determines that the number of shots is greater than the set number of shots (NO in S2206), processing from S2203 is performed again.

On the other hand, in a case where the determination unit 713 determines that the number of shots until a pressure exceeds the threshold value from the current number of shots is equal to or less than the number of shots set in the alarm notification setting 2106 (YES in S2206), the controller 700 outputs a notification sound indicating an alarm (S2207). In this case, the display control unit 715 may display a pop-up screen showing that gas combustion is approaching.

In the present embodiment, it is possible to enable a user to recognize in advance that gas combustion will occur under the above-mentioned control.

In the present embodiment, since the above-mentioned control is performed to estimate a time and the number of shots until gas combustion, it is possible to continue production until immediately before gas combustion occurs. Accordingly, productivity is improved because the frequency of cleaning of the mold unit 800 can be reduced. Moreover, since the frequency of cleaning is reduced, the cleaning load can be reduced.

In the present embodiment, since a time and the number of shots until gas combustion can be estimated, the cleaning schedule of the mold unit 800 can be managed. Accordingly, a workload can be reduced since a waiting time for cleaning the mold unit 800 can be reduced.

Since production can be continued until immediately before gas combustion occurs in the present embodiment, the frequency of cleaning of the mold unit 800 can be minimized and productivity can be improved.

Since a time until gas combustion is estimated in the present embodiment, it is possible to set a schedule for cleaning the mold unit 800.

<Operation>

Since the above-mentioned configuration is provided in the embodiments and the modification example described above, the control device 700 reduces the occurrence of a defective product by monitoring the gas combustion of a molded product based on the detected pressures.

Since the above-mentioned configuration is provided in the embodiments and the modification example described above, it is possible to present information about gas combustion (for example, whether gas combustion occurs or not, an estimated time until gas combustion occurs, or the like) to a user without inspecting gas combustion of a molded product. Accordingly, it is possible to suppress continuation of production of a molded product in a state where gas combustion occurs because it is possible to promptly take measures regarding gas combustion. Since a burden of inspection can be reduced and production errors can be suppressed, production costs can be reduced.

An example in which the display unit 760 displays information under control performed by the control device 700 as a display unit of the injection molding machine has been described in the above-mentioned embodiments. However, the above-mentioned embodiments show one aspect of the display unit of the injection molding machine and are not limited to this aspect. For example, control for displaying information may be performed by a control device provided in the display unit 760.

The control device of the injection molding machine and the display unit of the injection molding machine according to the embodiments of the present invention have been described above, but the present invention is not limited to the above-mentioned embodiments and the like. Various modifications, corrections, substitutions, additions, omissions and combinations can be made within the scope of the appended claims. Of course, these also belong to the technical scope of the present invention.

Short description of reference symbols

10

Injection molding machine

700

Control device

701

CPU

711

Adjustment unit

712

Registration unit

713

Determination unit

714

Protocol control unit

715

Display control unit

702

Storage medium

721

Log storage section

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• JP1991030926 [0002, 0004]

Claims (5)

A control device (700) of an injection molding machine (10), comprising: a detection unit (712) configured to detect information indicating a pressure from a detection unit (841) provided in the vicinity of an end portion at which a molding material (M) to be filled into a cavity space (801) formed in a molding unit (800) of the injection molding machine (10) enters the cavity space (801); and a control unit configured to determine whether or not gas combustion has occurred in a molded product produced by the injection molding machine (10), or to estimate or indicate a period until gas combustion occurs in the molded product, based on a predetermined condition related to the pressure detected at a time near a time when a filling process of the injection molding machine (10) is switched to a pressure holding process or near a time when the cavity space (801) is filled with the molding material (M) up to the end portion. Control device (700) of an injection molding machine (10) according to Claim 1 wherein the control unit determines that gas combustion has occurred in the molded product produced by the injection molding machine (10) in a case where the pressure detected at that time exceeds a threshold value determined as the predetermined condition. Control device (700) of an injection molding machine (10) according to Claim 1 wherein, in a case where a difference between the pressure detected at the time of the first injection molding and the pressure detected at the time of the second injection molding performed after the first injection molding is larger than a value determined as the predetermined condition, the control unit determines that gas combustion has occurred in the molded product produced in the second injection molding. Control device (700) of an injection molding machine (10) according to Claim 1 wherein the control unit calculates a time or the number of injections required until the predetermined condition is satisfied based on a change between the pressure detected at the time of the first injection molding and the pressure detected at the time of the second injection molding performed after the first injection molding, and outputs information on the time or the number of injections. A display unit (760) of an injection molding machine (10), comprising: a detection unit (712) configured to detect information indicating a pressure from a detection unit (841) provided near an end portion at which a molding material (M) to be filled into a cavity space (801) formed in a molding unit (800) of the injection molding machine (10) enters the cavity space (801); and a display control unit (715) configured to display a screen showing a transition of the pressure detected at a time near a time when a filling process of the injection molding machine (10) is switched to a pressure holding process or near a time when the cavity space (801) is filled with the molding material (M) up to the end portion, and information indicating a criterion of the pressure at which gas combustion occurs in a molded product produced by the injection molding machine (10).

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