JP2023148763A - Display input device of injection molding machine, controller of injection molding machine, and control method of injection molding machine - Google Patents

Abstract

To provide a technique for protecting a machine while improving the accuracy of a molded article of injection molding.SOLUTION: An injection molding machine comprises: an injection member provided inside a cylinder for heating a molding material; and an injection driving source which fills the molding material into a molding machine by advancing the injection member. A display input device of the injection molding machine displays a setting screen information for performing setting of actions, and allows a user to input setting information. The setting screen information has a speed limit input field on which a retreating speed limited value limiting a retreating speed of the injection member can be set, and an advancing speed limited value limiting an advancing speed of the injection member can be set, in a pressure holding process of controlling the injection driving source such that a filling pressure which works from the injection member to the molding material becomes a specified value.SELECTED DRAWING: Figure 7

Description

The present invention relates to a display input device for an injection molding machine, a control device for an injection molding machine, and a control method for an injection molding machine.

An injection molding machine has a cylinder that heats the molding material, an injection member provided inside the cylinder, an injection drive source that moves the injection member forward to fill the inside of the mold device with the molding material, and an injection drive source. A control device for controlling. The control device performs the filling process and the pressure holding process in this order. The filling step is a step of filling the inside of the mold device with the molding material by controlling the injection drive source so that the actual value of the moving speed of the injection member becomes the set value. In the pressure holding process, the injection drive source is controlled so that the actual value of the filling pressure acting on the molding material from the injection member becomes the set value, thereby replenishing the shortage of molding material due to cooling shrinkage within the mold equipment. This is the process of

Switching from the filling process to the pressure holding process is also called V/P switching. After V/P switching, if the actual value of the filling pressure is larger than the set value, the injection molding machine retreats the injection member so that the actual value of the filling pressure becomes smaller. Patent Document 1 states that by setting a limit value on the retraction speed of the injection member during the pressure holding process, it is possible to eliminate the negative effect on the quality of the molded product due to the screw retracting at high speed during the pressure holding process. has been done.

Patent No. 3917459

By the way, in the pressure holding process, whether the screw moves backward or continues moving forward depends on the difference in filling pressure after V/P switching. Since the filling pressure fluctuates depending on various influences such as the condition of the molding material and the condition of the mold device, the injection molding machine automatically controls advance or retreat of the pressure holding process by a control device. Further, depending on the injection molding, if the forward speed during the pressure holding step is too fast, it may cause damage to the equipment of the injection molding machine or molding defects of the molded product.

The present invention is based on the above-mentioned circumstances, and provides a technology that can protect machines during injection molding.

According to one aspect of the present invention, an injection member provided inside a cylinder that heats molding material, and an injection drive source that advances the injection member to fill the inside of a mold device with the molding material. A display input device for displaying setting screen information for setting operations and allowing a user to input setting information in an injection molding machine, wherein the setting screen information includes filling pressure acting on the molding material from the injection member. In the pressure holding step of controlling the injection drive source so that the injection drive source becomes a predetermined value, it is possible to set a backward speed limit value that limits the backward speed of the injection member, and a forward speed that limits the forward speed of the injection member. A display input device for an injection molding machine is provided that has a speed limit input field in which a limit value can be set.

The display input device for an injection molding machine, the control device for an injection molding machine, and the control method for an injection molding machine according to the present invention can improve the molding accuracy of a molded product while protecting the machine during injection molding.

FIG. 2 is a diagram showing a state of the injection molding machine according to an embodiment when mold opening is completed. 1 is a diagram showing a state of an injection molding machine according to an embodiment during mold clamping. FIG. FIG. 2 is a diagram showing an example of the components of the control device in functional blocks. It is a figure which shows an example of the process of a molding cycle. It is a figure showing an example of an injection control part. It is a figure which shows an example of the time change of a screw speed, a filling pressure, and a screw position. It is a figure which shows an example of setting screen information.

Hereinafter, embodiments for implementing the present disclosure will be described with reference to the drawings. In each drawing, the same components are given the same reference numerals, and redundant explanations may be omitted.

(Injection molding machine)
FIG. 1 is a diagram illustrating a state of an injection molding machine according to an embodiment when mold opening is completed. FIG. 2 is a diagram showing a state of the injection molding machine according to one embodiment during mold clamping. In this specification, the X-axis direction, the Y-axis direction, and the Z-axis direction are directions perpendicular to each other. The X-axis direction and the Y-axis direction represent the horizontal direction, and the Z-axis direction represents the vertical direction. When the mold clamping device 100 is a horizontal type, the X-axis direction is the mold opening/closing direction, and the Y-axis direction is the width direction of the injection molding machine 10. The negative side in the Y-axis direction is called the operation side, and the positive side in the Y-axis direction is called the counter-operation side.

As shown in FIGS. 1 and 2, the injection molding machine 10 includes a mold clamping device 100 that opens and closes a mold device 800, an ejector device 200 that ejects a molded product molded in the mold device 800, and a mold device 800 that ejects a molded product formed by the mold device 800. an injection device 300 that injects molding material into the mold, a moving device 400 that moves the injection device 300 forward and backward with respect to the mold device 800, a control device 700 that controls each component of the injection molding machine 10, and each of the injection molding machines 10. It has a frame 900 that supports the components. Frame 900 includes a mold clamping device frame 910 that supports mold clamping device 100 and an injection device frame 920 that supports injection device 300. The mold clamping device frame 910 and the injection device frame 920 are each installed on the floor 2 via a leveling adjuster 930. The control device 700 is arranged in the interior space of the injection device frame 920. Each component of the injection molding machine 10 will be explained below.

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

The mold clamping device 100 performs mold closing, pressurization, mold clamping, depressurization, and mold opening of the mold device 800. Mold device 800 includes a fixed mold 810 and a movable mold 820.

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

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

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

The moving mechanism 102 moves the movable platen 120 forward and backward relative to the fixed platen 110 to close the mold, increase the pressure, clamp the mold, depressurize the mold, and open the mold. The moving mechanism 102 includes a toggle support 130 arranged at a distance from the fixed platen 110, a tie bar 140 that connects the fixed platen 110 and the toggle support 130, and a movable platen 120 that moves the movable platen 120 in the mold opening/closing direction relative to the toggle support 130. a toggle mechanism 150 that operates the toggle mechanism 150, a mold clamping motor 160 that operates the toggle mechanism 150, a motion conversion mechanism 170 that converts the rotational motion of the mold clamping motor 160 into linear motion, and a mold that adjusts the distance between the fixed platen 110 and the toggle support 130. It has a thickness adjustment mechanism 180.

The toggle support 130 is arranged at a distance from the fixed platen 110 and is placed on the mold clamping device frame 910 so as to be movable in the mold opening/closing direction. Note that the toggle support 130 may be movably arranged along a guide laid on the mold clamping device frame 910. The guide of the toggle support 130 may be the same as the guide 101 of the movable platen 120.

In this embodiment, the fixed platen 110 is fixed to the mold clamping device frame 910, and the toggle support 130 is arranged to be movable in the mold opening/closing direction with respect to the mold clamping device frame 910. The fixed platen 110 may be fixed to the device frame 910 and may be arranged to be movable in the mold opening/closing direction with respect to the mold clamping device frame 910.

The tie bar 140 connects the fixed platen 110 and the toggle support 130 at a distance L in the mold opening/closing direction. A plurality of tie bars 140 (for example, four) may be used. The plurality of tie bars 140 are arranged parallel to the mold opening/closing direction, and expand according to the mold clamping force. At least one tie bar 140 may be provided with a tie bar distortion detector 141 that detects distortion of the tie bar 140. Tie bar distortion detector 141 sends a signal indicating the detection result to control device 700. The detection results of the tie bar distortion detector 141 are used for detecting mold clamping force and the like.

Note that in this embodiment, the tie bar strain detector 141 is used as a mold clamping force detector that detects mold clamping force, but the present invention is not limited to this. The mold clamping force detector is not limited to a strain gauge type, but may be a piezoelectric type, a capacitive type, a hydraulic type, an electromagnetic type, etc., and its mounting position is not limited to the tie bar 140 either.

The toggle mechanism 150 is disposed between the movable platen 120 and the toggle support 130, and moves the movable platen 120 relative to the toggle support 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 links that bend and expand as the crosshead 151 moves. Each of the pair of link groups includes a first link 152 and a second link 153 that are connected to each other with a pin or the like in a flexible manner. The first link 152 is swingably attached to the movable platen 120 with a pin or the like. The second link 153 is swingably attached to the toggle support 130 with a pin or the like. The second link 153 is attached to the crosshead 151 via a third link 154. When the crosshead 151 is moved forward and backward with respect to the toggle support 130, the first link 152 and the second link 153 are bent and extended, and the movable platen 120 is moved forward and backward with respect to the toggle support 130.

Note that the configuration of the toggle mechanism 150 is not limited to the configuration shown in FIGS. 1 and 2. For example, in FIGS. 1 and 2, the number of nodes in each link group is five, but it may be four, and one end of the third link 154 is connected to the nodes of the first link 152 and the second link 153. may be done.

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

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

The mold clamping device 100 performs a mold closing process, a pressure increasing process, a mold clamping process, a depressurizing process, a mold opening process, etc. under the control of the control device 700.

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

Note that the crosshead position detector that detects the position of the crosshead 151 and the crosshead movement speed detector that detects the moving speed of the crosshead 151 are not limited to the mold clamping motor encoder 161, but common ones may be used. can. Furthermore, the movable platen position detector that detects the position of the movable platen 120 and the movable platen movement speed detector that detects the moving speed of the movable platen 120 are not limited to the mold clamping motor encoder 161, but may be general ones. can.

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

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

The number of cavity spaces 801 may be one or more. In the latter case, multiple molded articles can be obtained simultaneously. An insert material may be placed in a part of the cavity space 801, and another part of the cavity space 801 may be filled with a molding material. A molded product in which the insert material and the molding material are integrated can be obtained.

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

In the mold opening process, the movable platen 120 is moved backward by driving the mold clamping motor 160 to move the crosshead 151 backward from the mold opening start position to the mold opening completion position at a set movement speed, and the movable mold 820 is moved between the fixed metal molds and the mold opening process. Separate from mold 810. Thereafter, the ejector device 200 ejects the molded product from the movable mold 820.

Setting conditions in the mold closing process, pressure increasing process, and mold clamping process are collectively set as a series of setting conditions. For example, the moving speed and position of the crosshead 151 (including the mold closing start position, the movement speed switching position, the mold closing completion position, and the mold clamping position) and the mold clamping force in the mold closing process and the pressure increasing process are determined by a series of setting conditions. are set all together as . The mold closing start position, the moving speed switching position, the mold closing completion position, and the mold closing position are arranged in this order from the rear side toward the front, and represent the starting point and ending point of the section in which the moving speed is set. A moving speed is set for each section. There may be one or more moving speed switching positions. The moving speed switching position does not need to be set. Only one of the mold clamping position and mold clamping force may be set.

Setting conditions in the depressurization process and mold opening process are similarly set. For example, the moving speed and position (mold opening start position, moving speed switching position, and mold opening completion position) of the crosshead 151 in the depressurization 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 the front side toward the rear, and represent the start point and end point of the section in which the movement speed is set. A moving speed is set for each section. There may be one or more moving speed switching positions. The moving speed switching position does not need to 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.

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

By the way, the toggle mechanism 150 amplifies the driving force of the mold clamping motor 160 and transmits it to the movable platen 120. The amplification factor is also called the toggle factor. The toggle magnification changes depending on the angle θ formed by the first link 152 and the second link 153 (hereinafter also referred to as “link angle θ”). The link angle θ is determined from the position of the crosshead 151. When the link angle θ is 180°, the toggle magnification is maximum.

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

The mold clamping device 100 has a mold thickness adjustment mechanism 180. The mold thickness adjustment mechanism 180 adjusts the mold thickness by adjusting the distance L between the fixed platen 110 and the toggle support 130. The mold thickness adjustment is performed, for example, between the end of a molding cycle and the start of the next molding cycle. The mold thickness adjustment mechanism 180 is, for example, screwed into a screw shaft 181 formed at the rear end of the tie bar 140, a screw nut 182 that is rotatably but not retractably held on the toggle support 130, and screwed onto the screw shaft 181. It has a mold thickness adjustment motor 183 that rotates a screw nut 182.

A screw shaft 181 and a screw nut 182 are provided for each tie bar 140. The rotational driving force of the mold thickness adjustment motor 183 may be transmitted to the plurality of threaded nuts 182 via the rotational driving force transmission section 185. A plurality of screw nuts 182 can be rotated synchronously. Note that by changing the transmission path of the rotational driving force transmission section 185, it is also possible to rotate the plurality of screw nuts 182 individually.

The rotational driving force transmission section 185 is composed of, for example, a gear. In this case, a driven gear is formed on the outer periphery of each screw nut 182, a driving gear is attached to the output shaft of the mold thickness adjustment motor 183, and an intermediate gear that meshes with the plurality of driven gears and the driving gear is located at the center of the toggle support 130. is held rotatably. Note that the rotational driving force transmission section 185 may be configured with a belt, a pulley, or the like instead of a gear.

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

The distance L is detected using a mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the rotation amount and rotation direction of the mold thickness adjustment motor 183 and sends a signal indicating the detection result to the control device 700. The detection results of the mold thickness adjustment motor encoder 184 are used for monitoring and controlling the position and interval L of the toggle support 130. Note that the toggle support position detector that detects the position of the toggle support 130 and the interval detector that detects the interval L are not limited to the mold thickness adjustment motor encoder 184, and general ones can be used.

The mold clamping device 100 may include a mold temperature regulator that adjusts the temperature of the mold device 800. The mold device 800 has a temperature control medium flow path therein. The mold temperature regulator adjusts the temperature of the mold device 800 by adjusting the temperature of the temperature regulating medium supplied to the flow path of the mold device 800.

Although the mold clamping device 100 of this embodiment is a horizontal type in which the mold opening/closing direction is a horizontal direction, it may be a vertical type in which the mold opening/closing direction is a vertical direction.

Although the mold clamping device 100 of this embodiment has a mold clamping motor 160 as a drive unit, it may have a hydraulic cylinder instead of the mold clamping motor 160. Moreover, the mold clamping device 100 may have a linear motor for opening and closing the mold, and may have an electromagnet for mold clamping.

(Ejector device)
In the description of the ejector device 200, similarly to the description of the mold clamping device 100, the moving direction of the movable platen 120 when closing the mold (for example, The explanation will be made assuming that the X-axis negative direction) is the rear direction.

Ejector device 200 is attached to movable platen 120 and moves forward and backward together with movable platen 120. Ejector device 200 includes an ejector rod 210 that ejects a molded product from mold device 800, and a drive mechanism 220 that moves ejector rod 210 in the moving direction of movable platen 120 (X-axis direction).

The ejector rod 210 is arranged in a through hole of the movable platen 120 so as to be able to move forward and backward. The front end of the ejector rod 210 contacts the ejector plate 826 of the movable mold 820. The front end of the ejector rod 210 may or may not be connected to the ejector plate 826.

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

The ejector device 200 performs an ejection process under the control of the control device 700. In the ejecting step, the ejector rod 210 is advanced from the standby position to the ejecting position at a set movement speed, thereby advancing the ejector plate 826 and ejecting the molded product. Thereafter, the ejector motor is driven to move the ejector rod 210 backward at a set movement speed, and the ejector plate 826 is moved back to its original standby position.

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

(injection device)
In the description of the injection device 300, unlike the description of the mold clamping device 100 and the ejector device 200, the direction of movement of the screw 330 during filling (for example, the negative direction of the X axis) is referred to as the front, and the direction of movement of the screw 330 during metering is (For example, the X-axis positive direction) will be explained as being backward.

The injection device 300 is installed on a slide base 301, and the slide base 301 is arranged to be movable forward and backward relative to the injection device frame 920. The injection device 300 is arranged to be movable forward and backward relative to the mold device 800. The injection device 300 touches the mold device 800 and fills the cavity space 801 in the mold device 800 with the molding material. The injection device 300 includes, for example, a cylinder 310 that heats the molding material, a nozzle 320 provided at the front end of the cylinder 310, a screw 330 that is rotatably disposed in the cylinder 310 so as to be able to move forward and backward, and rotate the screw 330. an injection motor 350 that moves the screw 330 forward and backward, and a load detector 360 that detects the load transmitted between the injection motor 350 and the screw 330.

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

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

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

The screw 330 is arranged within the cylinder 310 so as to be rotatable and movable back and forth. When the screw 330 is rotated, the molding material is sent forward along the spiral groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 while being sent forward. As the liquid molding material is sent forward of the screw 330 and accumulated at the front of the cylinder 310, the screw 330 is retracted. Thereafter, when the screw 330 is moved forward, the liquid molding material accumulated in front of the screw 330 is injected from the nozzle 320 and filled into the mold device 800.

A backflow prevention ring 331 is attached to the front of the screw 330 so that it can move forward and backward as a backflow prevention valve that prevents the molding material from flowing backward from the front of the screw 330 when the screw 330 is pushed forward.

When the screw 330 is advanced, the backflow prevention ring 331 is pushed backward by the pressure of the molding material in front of the screw 330, and is moved relative to the screw 330 to a closed position (see FIG. 2) where it blocks the flow path of the molding material. fall back. This prevents the molding material accumulated in front of the screw 330 from flowing backward.

On the other hand, when the screw 330 is rotated, the backflow prevention ring 331 is pushed forward by the pressure of the molding material sent forward along the spiral groove of the screw 330, and is moved to an open position where the flow path of the molding material is opened. (see FIG. 1) relative to the screw 330. As a result, the molding material is sent to the front of the screw 330.

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

Note that the injection device 300 may include a drive source that moves the backflow prevention ring 331 forward and backward relative to the screw 330 between an open position and a closed position.

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

The injection motor 350 moves the screw 330 forward and backward. A motion conversion mechanism or the like that converts the rotational motion of the injection motor 350 into linear motion of the screw 330 is provided between the injection motor 350 and the screw 330. The motion conversion mechanism includes, for example, a screw shaft and a screw nut that is threaded onto the screw shaft. A ball, roller, etc. may be provided between the screw shaft and the screw nut. The drive source for advancing and retracting the screw 330 is not limited to the injection motor 350, and may be, for example, a hydraulic cylinder.

Load detector 360 detects the load transmitted between injection motor 350 and screw 330. The detected load is converted into pressure by the control device 700. The load detector 360 is provided in a load transmission path between the injection motor 350 and the screw 330, and detects the load acting on the load detector 360.

Load detector 360 sends a detected load signal to control device 700. The load detected by the load detector 360 is converted into the pressure that acts between the screw 330 and the molding material, and includes the pressure that the screw 330 receives from the molding material, the back pressure on the screw 330, and the pressure that acts on the molding material from the screw 330. Used for controlling and monitoring pressure, etc.

Note that the pressure detector for detecting the pressure of the molding material is not limited to the load detector 360, and any general pressure detector can be used. For example, a nozzle pressure sensor or an internal mold pressure sensor may be used. A nozzle pressure sensor is installed on the nozzle 320. The mold internal pressure sensor is installed inside the mold device 800.

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

In the metering process, the screw 330 is rotated at a set rotation speed by driving the metering motor 340, and the molding material is sent forward along the spiral groove of the screw 330. Along with this, the molding material is gradually melted. As the liquid molding material is sent forward of the screw 330 and accumulated at the front of the cylinder 310, the screw 330 is retracted. The rotational speed of the screw 330 is detected using, for example, a metering motor encoder 341. Measuring motor encoder 341 detects the rotation of metering motor 340 and sends a signal indicating the detection result to control device 700. Note that the screw rotation speed detector for detecting the rotation speed of the screw 330 is not limited to the metering motor encoder 341, and a general type can be used.

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

The position and rotational speed of the screw 330 in the metering process are set together as a series of setting conditions. For example, a measurement start position, a rotational speed switching position, and a measurement completion position are set. These positions are lined up in this order from the front to the rear, and represent the start and end points of the section in which the rotational speed is set. The rotation speed is set for each section. The number of rotational speed switching positions may be one or more. The rotational speed switching position does not need to be set. Further, back pressure is set for each section.

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

The position and movement speed 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 moving speed switching position, and a V/P switching position are set. These positions are lined up in this order from the rear to the front, and represent the start and end points of the section in which the moving speed is set. A moving speed is set for each section. There may be one or more moving speed switching positions. The moving speed switching position does not need to be set.

The upper limit value of the pressure of the screw 330 is set for each section in which the moving speed of the screw 330 is set. The pressure of the screw 330 is detected by a load detector 360. When the pressure of the screw 330 is below the set pressure, the screw 330 is advanced at the set travel speed. On the other hand, when the pressure of the screw 330 exceeds the set pressure, the screw 330 is moved forward at a moving speed slower than the set moving speed so that the pressure of the screw 330 becomes equal to or lower than the set pressure for the purpose of protecting the mold.

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

In the pressure holding process, the injection motor 350 is driven to push the screw 330 forward, and the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "holding pressure") is maintained at the set pressure, and the pressure inside the cylinder 310 is maintained. The remaining molding material is pushed toward the mold apparatus 800. Insufficient molding material due to cooling shrinkage within the mold device 800 can be replenished. The holding pressure is detected using the load detector 360, for example. The set value of the holding pressure may be changed depending on the elapsed time from the start of the pressure holding process. A plurality of holding pressures and a plurality of holding times for holding the holding pressure in the pressure holding step may be set, and may be set all at once as a series of setting conditions.

In the pressure holding process, the molding material in the cavity space 801 in the mold device 800 is gradually cooled, and when the pressure holding process is completed, the entrance of the cavity space 801 is closed with the solidified molding material. This state is called a gate seal, and backflow of the molding material from the cavity space 801 is prevented. After the pressure holding process, a cooling process is started. In the cooling process, the molding material within the cavity space 801 is solidified. A metering step may be performed during the cooling step to reduce molding cycle time.

Although the injection device 300 of this embodiment is of an in-line screw type, it may also be of a pre-plastic type. A pre-plastic injection device supplies a molding material melted in a plasticizing cylinder to an injection cylinder, and injects the molding material from the injection cylinder into a mold device. Inside the plasticizing cylinder, a screw is arranged so as to be rotatable but not moveable, or a screw is arranged so as to be rotatable and move back and forth. On the other hand, a plunger is arranged within the injection cylinder so that it can move forward and backward.

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

(mobile device)
In the description of the moving device 400, similarly to the description of the injection device 300, the direction of movement of the screw 330 during filling (for example, the negative direction of the X-axis) is referred to as the front, and the direction of movement of the screw 330 during metering (for example, the positive direction of the X-axis) is referred to as the front. will be explained as backward.

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

Hydraulic pump 410 has a first port 411 and a second port 412. The hydraulic pump 410 is a bidirectionally rotatable pump, and by switching the rotation direction of the motor 420, the hydraulic pump 410 sucks in hydraulic fluid (for example, oil) from one of the first port 411 and the second port 412 and discharges it from the other. to generate hydraulic pressure. Note that the hydraulic pump 410 can also suck the hydraulic fluid from the tank and discharge the hydraulic fluid from either the first port 411 or the second port 412.

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

Hydraulic cylinder 430 has a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is fixed to the injection device 300. The piston 432 partitions the inside of the cylinder body 431 into a front chamber 435 as a first chamber and a rear chamber 436 as a second chamber. Piston rod 433 is fixed relative to fixed platen 110.

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

On the other hand, the rear chamber 436 of the hydraulic cylinder 430 is connected to the second port 412 of the hydraulic pump 410 via the second flow path 402 . The injection device 300 is pushed rearward by the hydraulic fluid discharged from the second port 412 being supplied to the rear chamber 436 of the hydraulic cylinder 430 via the second flow path 402. The injection device 300 is moved back, and the nozzle 320 is separated from the fixed mold 810.

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

(Control device)
The control device 700 is composed of, for example, a computer, and includes a CPU (Central Processing Unit) 701, a storage medium 702 such as a memory, an input interface 703, and an output interface 704, as shown in FIGS. The control device 700 performs various controls by causing the CPU 701 to execute programs stored in the storage medium 702. Furthermore, the control device 700 receives signals from the outside through an input interface 703 and transmits signals to the outside through an output interface 704.

The control device 700 controls the molded product by repeatedly performing a measuring process, a mold closing process, a pressurizing process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a depressurizing process, a mold opening process, an ejecting process, etc. Manufacture repeatedly. A series of operations for obtaining a molded product, for example, from the start of a metering process to the start of the next metering process, is also called a "shot" or a "molding cycle." The time required for one shot is also called "molding cycle time" or "cycle time."

One molding cycle includes, for example, a measuring process, a mold closing process, a pressure increasing process, a mold clamping process, a filling process, a pressure holding process, a cooling process, a depressurizing process, a mold opening process, and an ejecting process in this order. The order here is the starting order of each step. The filling process, pressure holding process, and cooling process are performed during the mold clamping process. The start of the mold clamping process may coincide with the start of the filling process. Completion of the depressurization process coincides with the start of the mold opening process.

Note that a plurality of steps may be performed simultaneously for the purpose of shortening the molding cycle time. For example, the metering step may be performed during the cooling step of the previous molding cycle, or during the clamping step. In this case, the mold closing step may be performed at the beginning of the molding cycle. Also, the filling process may be started during the mold closing process. Also, the ejection process may be started during the mold opening process. If an on-off valve is provided to open and close the flow path of the nozzle 320, the mold opening process may be started during the metering process. This is because even if the mold opening process is started during the metering process, if the on-off valve closes the flow path of the nozzle 320, the molding material will not leak from the nozzle 320.

Note that one molding cycle includes processes other than the measuring process, mold closing process, pressure increase process, mold clamping process, filling process, pressure holding process, cooling process, depressurization process, mold opening process, and ejection process. You can.

For example, after the pressure holding process is completed and before the measurement process is started, a pre-measurement suckback process may be performed in which the screw 330 is retreated to a preset measurement start position. The pressure of the molding material accumulated in front of the screw 330 before the start of the metering process can be reduced, and rapid retraction of the screw 330 at the start of the metering process can be prevented.

Further, after the completion of the measurement process and before the start of the filling process, a post-measurement suck-back process may be performed in which the screw 330 is retreated to a preset filling start position (also referred to as "injection start position"). The pressure of the molding material accumulated in front of the screw 330 before the start of the filling process can be reduced, and 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 operating device 750 that accepts input operations by a user and a display device 760 that displays a screen. The operating device 750 and the display device 760 are configured with, for example, a touch panel 770 (display input device), and may be integrated. The touch panel 770 serving as the display device 760 displays a screen under the control of the control device 700. Information such as the settings of the injection molding machine 10 and the current state of the injection molding machine 10 may be displayed on the screen of the touch panel 770, for example. Further, the screen of the touch panel 770 may display, for example, an operation unit such as a button or an input field that accepts an input operation by the user. The touch panel 770 serving as the operating device 750 detects an input operation on the screen by the user, and outputs a signal corresponding to the input operation to the control device 700. As a result, the user can, for example, configure the injection molding machine 10 (including inputting setting values) by operating the operation unit provided on the screen while checking the information displayed on the screen. can. Further, by the user operating an operating section provided on the screen, it is possible to cause the injection molding machine 10 to perform an operation corresponding to the operating section. Note that the operation of the injection molding machine 10 may be, for example, the operation (including stopping) of the mold clamping device 100, the ejector device 200, the injection device 300, the moving device 400, and the like. Further, the operation of the injection molding machine 10 may be switching of screens displayed on a touch panel 770 serving as the display device 760.

Note that although the operating device 750 and the display device 760 of this embodiment have been described as being integrated as the touch panel 770, they may be provided independently. Further, a plurality of operating devices 750 may be provided. The operating device 750 and the display device 760 are arranged on the operating side (Y-axis negative direction) of the mold clamping device 100 (more specifically, the fixed platen 110).

(Details of control device)
Next, an example of the components of the control device 700 will be described with reference to FIG. 3. Note that each functional block illustrated in FIG. 3 is conceptual and does not necessarily need to be physically configured as illustrated. It is possible to configure all or part of each functional block by functionally or physically distributing and integrating it in arbitrary units. All or any part of each processing function performed by each functional block can be realized by a program executed by a CPU, or can be realized by hardware using wired logic.

As shown in FIG. 3, the control device 700 includes, for example, a mold clamping control section 711, an ejector control section 712, an injection control section 713, a metering control section 714, and a setting section 715. The mold clamping control unit 711 controls the mold clamping device 100 and performs a mold closing process, a pressure increasing process, a mold clamping process, a depressurizing process, and a mold opening process shown in FIG. The ejector control unit 712 controls the ejector device 200 and performs the ejecting process. The injection control unit 713 controls the injection drive source of the injection device 300 and performs an injection process. The injection drive source is, for example, the injection motor 350, but may also be a hydraulic cylinder or the like. The injection process includes a filling process and a pressure holding process. The injection process is performed during the mold clamping process. The metering control unit 714 controls the metering drive source of the injection device 300 and carries out a metering process. The metering drive source is, for example, the metering motor 340, but may also be a hydraulic pump or the like. The metering process is performed during the cooling process.

The filling process is a process of controlling the injection drive source so that the actual value of the moving speed of the injection member provided inside the cylinder 310 becomes the set value. The filling step is a step of moving the injection member forward to fill the inside of the mold device 800 with the liquid molding material accumulated in front of the injection member. The injection member is, for example, a screw 330 (see FIGS. 1 and 2), but may also be a plunger.

The moving speed of the injection member is detected using a speed detector. The speed detector is, for example, the injection motor encoder 351. In the filling process, as the injection member moves forward, the pressure that acts on the molding material from the injection member (hereinafter also referred to as "filling pressure") increases. The filling step may include a step of temporarily stopping the injection member or a step of retracting the injection member immediately before the pressure holding step.

The pressure holding process is a process of controlling the injection drive source so that the actual value of the filling pressure becomes the set value. The holding pressure step is a step of pushing the injection member forward to replenish the molding material that is insufficient due to cooling shrinkage within the mold device 800. Filling pressure is detected using a pressure detector such as load detector 360. A nozzle pressure sensor or a mold internal pressure sensor may be used as the pressure detector.

The pressure holding process is controlled by the injection control section 713. As shown in FIG. 5, the injection control section 713 includes, for example, a speed setting section 713a and a command creation section 713b. The speed setting unit 713a creates a set value for the speed of the injection member based on the deviation between the set value of the filling pressure and the actual value. The command creation unit 713b creates a command (for example, a current command) for the injection drive source based on the deviation between the set value and the actual value of the speed of the injection member. The injection drive source is, for example, the injection motor 350. The injection drive source is driven according to the command created by the command creation section 713b.

The speed setting unit 713a creates a set value for the speed of the injection member so that the actual value of the filling pressure becomes the set value. The actual value of the filling pressure is obtained using a pressure detector such as the load detector 360. The speed setting unit 713a creates a set value for the speed of the injection member by, for example, PID calculation or PI calculation.

The command creation unit 713b creates a command to the injection drive source so that the actual value of the speed of the injection member becomes the set value. The actual value of the speed of the injection member is obtained using a speed detector such as the injection motor encoder 351. The command creation unit 713b creates commands for the injection drive source by, for example, PID calculation or PI calculation.

Furthermore, the injection control section 713 has a backward speed limiting section 713c and a forward speed limiting section 713d. The backward speed limiting section 713c and the forward speed limiting section 713d are arranged between the speed setting section 713a and the command generation section 713b, and are connected in series. Note that the order in which the backward speed limiter 713c and the forward speed limiter 713d are installed is not limited to the example shown in FIG. 5, and may be arranged in the order of the forward speed limiter 713d and the backward speed limiter 713c. Furthermore, the injection control section 713 may include a speed limiting section (not shown) that integrates the backward speed limiting section 713c and the forward speed limiting section 713d.

The retreating speed limiting section 713c limits the retreating speed of the injection member to a preset retreating speed limit value V1 (absolute value) or less when the injection member retreats in the pressure holding process. Thereby, in the pressure holding step, it is possible to eliminate the adverse effect on the quality of the molded product due to the injection member retreating at high speed. For example, the backward speed limiting section 713c compares the speed setting value created by the speed setting section 713a and the backward speed limiting value V1. As shown in FIG. 6(A), the setting value of the speed in retreat is a negative number when the forward movement of the injection member is a positive number. When the injection member is retracting, the retraction speed limiting section 713c compares the retraction speed (negative number speed) with the negative number retraction speed limit value V1, and determines the speed at which the retraction speed limit value V1 or more is reached (the speed that is closer to zero). ) is output to the forward speed limiter 713d as a speed setting value. Note that when the injection member moves forward, the backward speed limiting section 713c outputs the speed setting value created by the speed setting section 713a as is.

The forward speed limiter 713d limits the forward speed of the injection member to a preset forward speed limit value V2 (absolute value) or less when the injection member moves forward in the pressure holding process. Thereby, in the pressure holding step, it is possible to eliminate the adverse effect on the quality of the molded product due to the injection member moving forward at high speed. For example, the forward speed limiter 713d compares the speed setting value output from the backward speed limiter 713c with the forward speed limit value V2. When the injection member is moving forward, it is a positive number, so the speed that is less than or equal to the forward speed limit value V2 (the speed that is closer to zero) is output to the command generation unit 713b as the speed setting value. Note that when the injection member moves backward, the forward speed limiter 713d outputs the speed setting value outputted by the backward speed limiter 713c as is.

Returning to FIG. 3, the setting unit 715 of the control device 700 allows the user to set the backward speed limit value V1 and the forward speed limit value V2 of the injection member in the pressure holding process. For example, the setting unit 715 generates setting screen information 771 on which settings for the pressure holding process as shown in FIG. 7 can be input, and displays this setting screen information 771 on the touch panel 770. The user can set the backward speed limit value V1 and the forward speed limit value V2 by inputting setting information on the setting screen information 771 of the touch panel 770.

The setting screen information 771 includes, for example, a speed limit input field 772 for inputting a reverse speed limit value V1 and a forward speed limit value V2. The speed limit input field 772 is provided at different positions, for example, a reverse speed input field 772a for inputting the reverse speed limit value V1 and a forward speed input field 772b for inputting the forward speed limit value V2. In addition, in FIG. 7, the forward speed input field 772b is referred to as the speed during holding pressure so that the user can easily recognize it. In this way, the speed limit input field 772 allows the user to set the backward speed limit value V1 and the forward speed limit value V2 separately, so that the user can set the forward and backward speeds of the injection member in the pressure holding process. can be set in detail.

Further, the setting screen information 771 in FIG. 7 displays a pressure holding information input field 773 for inputting other information regarding the pressure holding process between the backward speed input field 772a and the forward speed input field 772b. Thereby, it is possible to suppress input errors of the backward speed limit value V1 and the forward speed limit value V2 by the user.

The control device 700 may be configured to, at the user's option, not to limit the backward speed or the forward speed with respect to the backward or forward movement of the injection member in the pressure holding process. For example, the setting unit 715 can input or select restriction off information (off in the lower diagram of FIG. 7) indicating that no restriction will be applied in the reverse speed input field 772a or the forward speed input field 772b, so that the setting unit 715 can input or select the restriction off information (off in the lower diagram of FIG. 7). Therefore, the backward speed limit value V1 or the forward speed limit value V2 is not required. When the injection control section 713 receives the setting of this limit off information, it sets the speed of the speed setting section 713a without operating the limit sections that are turned off (reverse speed limit section 713c, forward speed limit section 713d). The value is sent to the command generation unit 713b to control the injection drive source. As a result, the injection molding machine 10 operates without limiting the backward speed or the forward speed at the user's discretion, and it is possible to give priority to improving the efficiency of molding the molded product.

Note that the speed limit input field 772 has one speed input field (not shown), and both the reverse speed limit value V1 and the forward speed limit value V2 are set based on one value input in the speed input field by the user. It may also be configured to set. Thereby, the speed during the pressure holding process can be set more easily.

Further, it is preferable that the setting unit 715 disables input of a forward speed or a backward speed that exceeds the mechanical limit of the injection member. For example, when the user inputs an input value that exceeds the mechanical limit of the injection member in the speed limit input field 772, the setting unit 715 displays error information indicating the speed range of the mechanical limit in a pop-up or the like to limit the speed. It is a good idea to request the user to re-enter the value.

As described above, the display input device (touch panel 770) of the injection molding machine 10 allows the user to set the backward speed limit value V1 and the forward speed limit value V2 of the injection member in the pressure holding process via the setting screen information 771. . Thereby, the injection molding machine 10 can suppress the speed of both the retreat and advance of the injection member during the pressure holding process, and can avoid molding defects and damage to the machine due to high speeds. . That is, the injection molding machine 10 can improve the accuracy of injection molded products while protecting the machine. Note that the display input device of the injection molding machine 10 is not limited to the touch panel 770 in which the operating device 750 and the display device 760 are integrated, and it goes without saying that they may be configured as separate bodies. For example, the input device may be a keyboard, mouse, button, remote controller, microphone for voice input, etc., and the display device may be a liquid crystal monitor, CRT monitor, etc.

Furthermore, by providing the setting screen information 771 with a reverse speed input field 772a and a forward speed input field 772b in different positions, the user can set each of the reverse speed limit value V1 and the forward speed limit value V2 in detail. . This allows the injection molding machine 10 to accurately control the operation of the injection member during the pressure holding process.

Alternatively, the injection molding machine 10 may be configured to automatically set the backward speed limit value V1 and the forward speed limit value V2 in the control device 700, regardless of the user. For example, the control device 700 calculates the optimal backward speed limit value V1 and forward speed limit value V2 based on the information on the molding material, the information on the mold device, the speed of the screw 330 in the past pressure holding process, the filling pressure, etc. It's good to do that.

The injection molding machine 10 according to this embodiment is basically configured as described above, and the operations of the filling process and the pressure holding process will be described below with reference to FIG. 6. FIG. 6 is a graph illustrating the time change of the screw (injection member) speed, the time change of the filling pressure, and the time change of the screw (injection member) position, where (A) shows when the injection member is retreating, and (B) ) indicates when the injection member is moving forward. Note that the screw position is expressed as a distance from the forward limit position of the movable range of the screw 330, and the farther the screw 330 retreats from the forward limit position, the greater the distance representing the screw position becomes.

In FIG. 6(A), t0 is the start time of the filling process, t1 is the time of V/P switching, t2 is the time when the backward speed (absolute value) of the screw speed becomes equal to or higher than the backward speed limit value V1, and t3 is The time t4 when the backward speed becomes less than the backward speed limit value V1 represents the end time of the pressure holding process. If the filling pressure is high in the filling process (t0 to t1) of injection molding, the actual value of the filling pressure is significantly larger than the set value P1 in the pressure holding process after V/P switching (after time t1). As a result, the screw 330 performs a retreating operation during the pressure holding process.

At the start of the pressure holding process, the backward speed limiting section 713c uses the speed setting value of the speed setting section 713a. In FIG. 6A, the actual value of the backward speed of the screw 330 is equal to or higher than the backward speed limit value V1 (absolute value) at time t2.

Therefore, after time t2, the backward speed limiter 713c sets the backward speed at the backward speed limit value V1 so that the backward speed of the screw 330 does not exceed the backward speed limit value V1. Then, at time t3 when the filling pressure has decreased to some extent, the retraction speed limiting section 713c retracts the screw 330 using the speed setting value of the speed setting section 713a. Thereby, the injection molding machine 10 can suppress damage to the screw 330 and molding defects of the molded product in the mold device 800, which are caused by rapidly increasing the retraction speed of the screw 330 in the pressure holding process.

On the other hand, in FIG. 6(B), t0 is the start time of the filling process, t1 is the time of V/P switching, t2 is the time when the forward speed (absolute value) of the screw speed becomes equal to or higher than the forward speed limit value V2, and t3 t4 represents the time when the forward speed became less than the forward speed limit value V2, and t4 represents the end time of the pressure holding process. Note that FIGS. 6(A) and 6(B) have different scales for the forward speed, backward speed, and filling pressure, and therefore, the set value P1 of the filling pressure is displayed offset. As shown in FIG. 6(B), since the filling pressure is small in the injection molding filling process (t0 to t1), even in the pressure holding process after V/P switching (after time t1), the actual filling pressure is The value becomes significantly smaller than the set value P1. As a result, the control device 700 performs an operation of advancing the screw 330 in the pressure holding process.

At the start of the pressure holding process, the forward speed limiter 713d uses the speed setting value output from the backward speed limiter 713c to compare it with the forward speed limit value V2. In FIG. 6(B), the actual value of the forward speed of the screw 330 becomes equal to or higher than the forward speed limit value V2 (absolute value) at time t2.

Therefore, after time t2, the forward speed limiter 713d sets the forward speed at the forward speed limit value V2 so that the forward speed of the screw 330 does not exceed the forward speed limit value V2. Then, at time t3 when the filling pressure has increased to a certain extent, the forward speed limiting section 713d moves the screw 330 forward again using the speed setting value of the speed setting section 713a. Thereby, the injection molding machine 10 can suppress damage to the screw 330 and molding defects in the mold device 800 caused by rapidly increasing the forward speed of the screw 330 in the pressure holding process.

As described above, the control device 700 and control method for the injection molding machine 10 according to the present embodiment easily control the speed of the injection member in the pressure holding process within the range of the backward speed limit value V1 and the forward speed limit value V2. can do. Therefore, the injection molding machine 10 can improve the molding accuracy of injection molded products while protecting the machine.

The display input device (touch panel 770) of the injection molding machine 10, the control device 700 of the injection molding machine 10, and the control method of the injection molding machine 10 according to the embodiment disclosed this time are illustrative and restrictive in all respects. It's not something. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the plurality of embodiments described above may be configured in other ways without being inconsistent, and may be combined without being inconsistent.

10 Injection molding machine 310 Cylinder 330 Screw 350 Injection motor 700 Control device 770 Touch panel 771 Setting screen information 772 Speed limit input field V1 Backward speed limit value V2 Forward speed limit value

Claims (6)

An injection molding machine including an injection member provided inside a cylinder that heats a molding material, and an injection drive source that moves the injection member forward to fill the inside of a mold device with the molding material. A display/input device that displays setting screen information to allow a user to input setting information,
The setting screen information is
In the pressure holding step of controlling the injection drive source so that the filling pressure acting on the molding material from the injection member becomes a predetermined value, it is possible to set a retraction speed limit value that limits the retraction speed of the injection member, and has a speed limit input field in which a forward speed limit value that limits the forward speed of the injection member can be set.
Display input device for injection molding machines. The setting screen information includes, as the speed limit input field,
A reverse speed input field in which the reverse speed limit value can be set and a forward speed input field in which the forward speed limit value can be set are provided in different positions.
A display input device for an injection molding machine according to claim 1. In the limit speed input field, limit off information for disabling the limit on the backward speed or the limit on the forward speed of the injection member can be input.
A display input device for an injection molding machine according to claim 1 or 2. A control device for an injection molding machine, comprising: an injection member provided inside a cylinder that heats molding material; and an injection drive source that moves the injection member forward to fill the inside of a mold device with the molding material. hand,
In the pressure holding step of controlling the injection drive source so that the filling pressure acting on the molding material from the injection member becomes a predetermined value, the retraction speed of the injection member is limited to a preset retraction speed limit value or less. a reverse speed limiter;
In the pressure holding step, a forward speed limiting section that limits the forward speed of the injection member to a preset forward speed limit value or less;
Control device for injection molding machine. The backward speed limiting section and the forward speed limiting section can be set to disable limiting the backward speed or limiting the forward speed of the injection member based on a user's operation.
A control device for an injection molding machine according to claim 4. A method for controlling an injection molding machine comprising: an injection member provided inside a cylinder that heats molding material; and an injection drive source that advances the injection member to fill the inside of a mold device with the molding material. hand,
In a pressure holding step of controlling the injection drive source so that the filling pressure acting on the molding material from the injection member becomes a predetermined value,
When the injection member moves backward, the backward speed of the injection member is limited to a preset backward speed limit value or less, and when the injection member moves forward, the forward speed of the injection member is limited to a preset backward speed limit value. a step of limiting the forward speed to below a forward speed limit value;
How to control an injection molding machine.

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