CONTROL FOR SPRAYING MACHINE AND SPRAYING MACHINE

Abstract

Control system for an injection molding machine, comprising a digital circuit configured to respond to the receipt of a signal indicating the detection of a predetermined event by a detector provided in the injection molding machine, comprising a motor configured to supply energy to move a moving part, and a brake for the motor, outputting a first signal to perform an energy interruption to cut off the power supply to the motor and outputting a second signal to control the braking by controlling the brake, such that control of the output of the second signal is performed after control of the output of the first signal.

Description

BACKGROUND 1. Technical field

[0001] The present disclosure relates to a control system for an injection molding machine and an injection molding machine. 2. Description of the state of the art

[0002] Various control systems have been implemented to ensure safety during the operation of injection molding machines. For example, Japanese unexamined patent publication No. 2007-230113 discloses an injection molding machine comprising a safety door, a detector configured to detect the open / closed state of the safety door, and a control unit configured to stop a driver based on a detection result received from the detector. The control unit of this injection molding machine stops a motor drive by halting the excitation of a coil of a relay switch configured to drive a motor of a closing / clamping mechanism, in response to a switch being toggled according to the opening of the safety door.

[0003] In existing injection molding machines, stopping a moving part typically involves interrupting the energy of an actuator configured to drive the moving part and applying brake control via a brake configured to stop the actuator. In these machines, the energy interruption and brake control are performed by separate devices. Because the energy interruption and brake control are performed by different devices, it has been difficult to execute the energy interruption and brake control in this sequence with high accuracy when stopping the moving part.

[0004] One aspect of the present disclosure relates to a technology for improving safety when performing energy interruption and brake control in this sequence, thereby achieving an improvement in safety. SUMMARY

[0005] A control system for an injection molding machine according to one aspect of the present disclosure comprises a digital circuit configured, in response to receiving a signal indicating the detection of a predetermined event from a detector provided in the injection molding machine, which includes a motor configured to supply energy to move a moving part and a brake for the motor, to output a first signal to perform an energy interruption to interrupt the energy supply to the motor and to output a second signal to control the braking by means of the brake, such that control of the output of the second signal is performed after control of the output of the first signal.

[0006] One aspect of the present disclosure improves safety when performing energy interruption and brake control in this sequence, thereby achieving an improvement in safety. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram illustrating the state of an injection molding machine according to one embodiment at the completion of mold openings; Fig. 2 is a view illustrating the state of the injection molding machine according to the embodiment during mold closing / clamping; Fig. Figure 3 is a diagram illustrating an example of an electrical configuration of a programmable logic controller (PLC) according to one embodiment; Fig. 4 is a functional configuration diagram illustrating a main configuration of a controller and the PLC according to one embodiment; Fig. Figure 5 is a timing diagram of the energy interruption and brake control by a brake, which is carried out when a safety door on an injection molding machine according to one embodiment is opened; and Fig. Figure 6 is a diagram illustrating an example of an electrical configuration of a PLC according to a further embodiment. DETAILED DESCRIPTION

[0007] The following describes embodiments of the present disclosure with reference to the drawings. The embodiments described below should not be construed as limiting the present disclosure; that is, they are merely examples. The features or combinations of features described in the embodiments are not necessarily essential to the present disclosure. In the drawings, identical or corresponding configurations are designated using the same or corresponding symbols, and descriptions thereof may be omitted.

[0008] Fig. Figure 1 is a diagram illustrating the state of an injection molding machine according to one embodiment at the completion of mold opening. Fig. Figure 2 is a diagram illustrating the state of the injection molding machine according to one embodiment during mold closing / clamping. In this description, the X-axis, Y-axis, and Z-axis directions are perpendicular to each other. The X-axis and Y-axis directions represent horizontal directions, and the Z-axis direction represents a vertical direction. If a mold closing / clamping part 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. The negative side in the Y-axis direction is referred to as the "operating side," and the positive side in the Y-axis direction is referred to as the "non-operating side."

[0009] As in Fig. 1 and Fig. As illustrated in Figure 2, the injection molding machine 10 comprises the mold clamping / closing part 100, which opens and closes a mold part 800; an ejector 200, which ejects a molded product into the mold part 800; an injection part 300, which injects molding material into the mold part 800; a movement part 400, which moves the injection part 300 to and from the mold part 800; a control unit 700, which controls the components of the injection molding machine 10; and a frame 900, which supports the components of the injection molding machine 10. The frame 900 comprises a mold clamping / closing part frame 910, which supports the mold clamping / closing part 100, and an injection part frame 920, which supports the injection part 300. Each of the form-closing / clamping frame 910 and the injection frame 920 is installed on a base 2 via at least one height adjuster 930. The control unit 700 is located inside the injection frame 920.The following describes each component of the injection molding machine 10. (Form-fit / clamping part)

[0010] In the description of the mold closing / clamping part 100, the direction of movement of a movable plate 120 during mold closing (e.g. the positive X-axis direction) is referred to as the "forward direction", and the direction of movement of the movable plate 120 during mold opening (e.g. the negative X-axis direction) is referred to as the "reverse direction".

[0011] The mold-closing / clamping element 100 closes, pressurizes, clamps, releases pressure, and opens the mold 800. The mold 800 comprises a stationary mold 810 and a movable mold 820. The mold-closing / clamping element 100 is, for example, of a horizontal type, and the mold opening and closing directions are horizontal. The mold-closing / clamping element 100 comprises a stationary plate 110 to which the stationary mold 810 is attached, the movable plate 120 to which the movable mold 820 is attached, and a movement mechanism 102 that moves the movable plate 120 in the mold opening and closing direction relative to the stationary plate 110.

[0012] The stationary plate 110 is attached to the form-closing / clamping frame 910. The stationary form 810 is attached to a surface of the stationary plate 110 that faces the movable plate 120.

[0013] The movable plate 120 is arranged so that it is movable relative to the mold closing / clamping frame 910 in the mold opening and closing direction. A guide 101, which guides the movable plate 120, is placed on the mold closing / clamping frame 910. The movable mold 820 is attached to a surface of the movable plate 120 that faces the stationary plate 110.

[0014] The movement mechanism 102 moves the movable plate 120 to the stationary plate 110 and away from it in order to close, pressurize, clamp, release pressure and open the molded part 800. The movement mechanism 102 comprises a toggle lever carrier 130 spaced apart from the stationary plate 110, a column 140 connecting the stationary plate 110 and the toggle lever carrier 130, a toggle lever mechanism 150 moving the movable plate 120 in the mold opening and closing direction relative to the toggle lever carrier 130, a mold closing / clamping motor 160 actuating the toggle lever mechanism 150, a motion conversion mechanism 170 converting the rotary motion of the mold closing / clamping motor 160 into linear motion, and a mold thickness adjustment mechanism 180 adjusting the distance between the stationary plate 110 and the toggle lever carrier 130.

[0015] The toggle lever carrier 130 is spaced apart from the stationary plate 110 and arranged on the mold closing / clamping frame 910 to be movable in the mold opening and closing direction. The toggle lever carrier 130 can be arranged to be movable along a guide placed on the mold closing / clamping frame 910. The guide 101 of the movable plate 120 can also serve as the guide for the toggle lever carrier 130.

[0016] According to the present embodiment, the stationary plate 110 is attached to the mold closing / clamping frame 910, and the toggle lever carrier 130 is arranged to be movable relative to the mold closing / clamping frame 910 in the mold opening and closing direction. However, the toggle lever carrier 130 can also be attached to the mold closing / clamping frame 910, and the stationary plate 110 can be arranged to be movable relative to the mold closing / clamping frame 910 in the mold opening and closing direction.

[0017] The column 140 connects the stationary plate 110 and the toggle lever support 130 with a distance L between them in the mold opening and closing direction. Several columns (e.g., four) can be used as columns 140. The multiple columns 140 are arranged parallel to the mold opening and closing direction and extend according to a mold closing / clamping force. At least one column 140 among the multiple columns 140 can be equipped with a column strain detector 141, which detects the strain of the column 140. The column strain detector 141 transmits a signal indicating the detection result to the controller 700. The detection result of the column strain detector 141 is used to detect the mold closing / clamping force.

[0018] According to the present embodiment, the column strain detector 141 is used as a form-closing / clamping force detector to detect a form-closing / clamping force. However, the present disclosure is not limited to this configuration. The form-closing / clamping force detector is not limited to being of a strain gauge type and can, for example, be of a piezoelectric, capacitive, hydraulic, or electromagnetic type, and its mounting location is not limited to the column 140.

[0019] The toggle mechanism 150 is arranged between the movable plate 120 and the toggle support 130 and moves in the mold opening and closing direction of the movable plate 120 relative to the toggle support 130. The toggle mechanism 150 comprises a crosshead 151, which moves in the mold opening and closing direction, and a pair of connecting links that are extended and retracted by the movement of the crosshead 151. Each connecting link group comprises a first connecting link 152 and a second connecting link 153, which, when connected by a pin or the like, are extendable and retractable. The first connecting link 152 is pivotally attached to the movable plate 120 by a pin or the like. The second connecting link 153 is pivotally attached to the toggle support 130 by a pin or the like. The second connecting link 153 is attached to the crosshead 151 via a third connecting link 154.The crosshead 151 is moved towards or away from the toggle lever carrier 130 in order to pull the first connecting link 152 and the second connecting link 153 together or apart in order to move the movable plate 120 towards or away from the toggle lever carrier 130.

[0020] The configuration of the toggle lever mechanism 150 is not based on the one in Fig. 1 and Fig. The configuration shown in section 2 is limited. For example, the number of nodes in each link group that is in Fig. 1 and Fig. 2 five is, four be, and one end of the third connecting link 154 may be connected to the knot of the first connecting link 152 and the second connecting link 153.

[0021] The form-locking / clamping motor 160 is attached to the toggle lever carrier 130 to actuate the toggle lever mechanism 150. The form-locking / clamping motor 160 moves the crosshead 151 towards or away from the toggle lever carrier 130 to pull the first connecting link 152 and the second connecting link 153 together or extend them, thereby moving the movable plate 120 towards or away from the toggle lever carrier 130. The form-locking / clamping motor 160, which is directly connected to the motion conversion mechanism 170, can alternatively be connected to the motion conversion mechanism 170 via a belt or pulley.

[0022] The form-closing / clamping motor 160 includes a built-in motor brake 162. The motor brake 162 operates to stop the rotation of a motor shaft of the form-closing / clamping motor 160. The motor brake 162 is, for example, a non-excitation brake and operates when the power supply is stopped.

[0023] The motion conversion mechanism 170 converts the rotary motion of the form-closing / clamping motor 160 into the linear motion of the crosshead 151. The motion conversion mechanism 170 comprises a spindle shaft and a spindle nut screwed to the spindle shaft. Balls or rollers can be arranged between the spindle shaft and the spindle nut.

[0024] The form-closing / clamping part 100, under the control of the control unit 700, performs a form-closing process, a pressurization process, a form-closing / clamping process, a pressure-relieving process, a form-opening process and the like.

[0025] During the mold closing process, the mold closing / clamping motor 160 is driven to move the crosshead 151 forward at a set speed into a mold closing position, thereby moving the moving platen 120 forward to cause the moving mold 820 to contact the stationary mold 810. The position and speed of the crosshead 151 are detected using a mold closing / clamping motor encoder 161 or the like. The mold closing / clamping motor encoder 161 detects the rotation of the mold closing / clamping motor 160 and transmits a signal indicating the detection results to the controller 700.

[0026] A crosshead position detector, which detects the position of the crosshead 151, and a crosshead motion velocity detector, which detects the motion velocity of the crosshead 151, are not limited to the form-closing / clamping motor encoder 161, and common detectors can be used. Furthermore, a moving plate position detector, which detects the position of the moving plate 120, and a moving plate motion velocity detector, which detects the motion velocity of the moving plate 120, are not limited to the form-closing / clamping motor encoder 161, and common detectors can be used.

[0027] During the pressurization process, the mold closing / clamping motor 160 is driven further to move the crosshead 151 further from the mold closing end position into a mold closing / clamping position, thereby generating a mold closing / clamping force.

[0028] During 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. The mold closing / clamping force generated during the pressurization process is maintained during the mold closing / clamping process. During the mold closing / clamping process, a cavity 801 is created between the moving mold 820 and the stationary mold 810 (see Fig. 2) formed, and the injection part 300 fills the cavity 801 with a liquid molding material. The molding material solidifies, resulting in a molded product.

[0029] The number of cavity spaces 801 can be one or more. In the latter case, several molded products are obtained simultaneously. A casting material can be arranged in one part of the cavity space 801, and the molding material can fill another part of the cavity space 801. This results in a molded product in which the casting material and the molding material are integrated.

[0030] During the pressure relief process, the mold closing / clamping motor 160 is driven to move the crosshead 151 backward from the mold closing / clamping position to a mold opening start position, thereby moving the movable platen 120 backward to reduce the mold closing / clamping force. The mold opening start position and the mold closing end position can be the same.

[0031] During the mold opening process, the mold closing / clamping motor 160 is driven to move the crosshead 151 backward from the mold opening start position to a mold opening closing position at a set speed, in order to move the moving platen 120 backward to separate the moving mold 820 from the stationary mold 810. The ejector 200 then ejects the molded product from the moving mold 820.

[0032] The set conditions for the mold closing operation, the pressurization operation, and the mold closing / clamping operation are set together as a set of set conditions. For example, the movement speed and positions (including a mold closing start position, a movement speed change position, the mold closing end position, and the mold closing / clamping position) of the crosshead 151 and the mold closing / clamping force during the mold closing operation and the pressurization operation are set together as a set of set conditions. The mold closing start position, the movement speed change position, the mold closing end position, and the mold closing / clamping position, arranged in that order in the forward direction from the rear, represent the start and end points of sections for which the movement speed is set.The movement speed is set section by section. There may be one or more movement speed switching positions. The movement speed switching position does not have to be set. It may be that only one of the mold closing / clamping position or the mold closing / clamping force is set.

[0033] Setting conditions for the pressure release and mold opening processes are also configured. For example, the movement speed and positions (the mold opening start position, the movement speed change position, and the mold opening end position) of the crosshead 151 are set together as a set of setting conditions for both the pressure release and mold opening processes. The mold opening start position, the movement speed change position, and the mold opening end position, arranged in that order in reverse from the front, represent the start and end points of sections for which the movement speed is set. The movement speed is set section by section. There can be one or more movement speed change positions. The movement speed change position does not have to be set.The mold opening start position and the mold closing end position can be the same position. The mold opening end position and the mold closing start position can be the same position.

[0034] Instead of the speed, position, and similar parameters of the crosshead 151, the speed, position, and similar parameters of the movable plate 120 can be set. Furthermore, instead of the crosshead position (e.g., the mold closing / clamping position) or the position of the movable plate, the mold closing / clamping force can be set.

[0035] The toggle lever mechanism 150 amplifies the drive force of the form-closing / clamping motor 160 and transmits the amplified drive force to the movable plate 120. The amplification factor is also referred to as the "toggle lever amplification factor." The toggle lever amplification factor changes according to the angle θ formed by the first connecting link 152 and the second connecting link 153 (hereinafter also referred to as the "connecting link angle θ"). The connecting link angle θ is determined from the position of the crosshead 151. The toggle lever amplification factor is maximized when the connecting link angle θ is 180°.

[0036] If there is a change in the thickness of the molded part 800 due to its replacement or a change in its temperature, the mold thickness is adjusted to achieve a predetermined mold closing / clamping force at the time of mold closing / clamping. For example, when adjusting the mold thickness, the distance L between the stationary plate 110 and the toggle lever support 130 is adjusted so that the link angle θ of the toggle lever mechanism 150 forms a predetermined angle at the time of mold contact, when the movable mold 820 contacts the stationary mold 810.

[0037] The mold clamping / closing part 100 includes the mold thickness adjustment mechanism 180. The mold thickness adjustment mechanism 180 adjusts the mold thickness by changing the distance L between the stationary plate 110 and the toggle lever support 130. The mold thickness is adjusted, for example, between the end of one molding cycle and the beginning of the next. The mold thickness adjustment mechanism 180 includes, for example, a spindle shaft 181 formed at the rear end of each column 140, a spindle nut 182 held on the toggle lever support 130 so that it is rotatable and cannot move forward or backward, and a mold thickness adjustment motor 183 that rotates the spindle nut 182, which engages with the spindle shaft 181.

[0038] The spindle shaft 181 and the spindle nut 182 are provided for each column 140. The rotary drive force of the mold thickness adjustment motor 183 can be transmitted to the multiple spindle nuts 182 via a rotary drive force transmission part 185. It is possible to rotate the multiple spindle nuts 182 synchronously. The multiple spindle nuts 182 can be rotated individually by changing the transmission channel of the rotary drive transmission part 185.

[0039] The torque transmission component 185 is, for example, constructed from gears. In such a case, a driven gear is formed on the circumference of each spindle nut 182, a drive gear is mounted on the output shaft of the mold thickness adjustment motor 183, and an intermediate gear, which meshes with the driven gears and the drive gear, is rotatably held in the center of the toggle lever carrier 130. The torque transmission component 185 can also be constructed from a belt and pulleys instead of gears.

[0040] The operation of the mold thickness adjustment mechanism 180 is controlled by the controller 700. The controller 700 drives the mold thickness adjustment motor 183 to rotate the spindle nuts 182. As a result, the position of the toggle lever support 130 relative to the columns 140 is adjusted, and the distance L between the stationary plate 110 and the toggle lever support 130 is adjusted. Several mold thickness adjustment mechanisms can be used in combination.

[0041] The distance L is detected using a mold thickness adjustment motor encoder 184. The mold thickness adjustment motor encoder 184 detects the rotational speed and direction of the mold thickness adjustment motor 183 and transmits a signal indicating the detection results to the controller 700. The detection results of the mold thickness adjustment motor encoder 184 are used to monitor and control the position of the toggle lever carrier 130 and the distance L. A toggle lever carrier position detector, which detects the position of the toggle lever carrier 130, and a distance detector, which detects the distance L, are not limited to the mold thickness adjustment motor encoder 184, and common detectors can be used.

[0042] The mold thickness adjustment motor 183 includes a built-in motor brake 186. The mold thickness adjustment motor 183 operates to stop the rotation of a motor shaft of the mold thickness adjustment motor 183. The motor brake 186 is, for example, a non-excitation brake and operates when the power supply is stopped.

[0043] The mold clamping / closing part 100 can include a mold temperature adjuster that adapts the temperature of the mold part 800. The mold part 800 contains a flow path for a temperature adjustment medium. The mold temperature adjuster adapts the temperature of the mold part 800 by adjusting the temperature of the temperature adjustment medium supplied to the flow path of the mold part 800.

[0044] The form-closing / clamping part 100, which according to the present embodiment is of a horizontal type, whose form opening and closing directions are horizontal directions, can also be of a vertical type, whose form opening and closing directions are vertical directions.

[0045] The mold closing / clamping part 100, which according to the present embodiment includes the mold closing / clamping motor 160 as a drive source, can also include a hydraulic cylinder instead of the mold closing / clamping motor 160. Furthermore, the mold closing / clamping part 100 can include a linear motor for opening and closing the mold and can include an electromagnet for closing / clamping the mold. (Ejector)

[0046] In the description of the ejector 200, similar to the description of the mold closing / clamping part 100, the direction of movement of the movable plate 120 during mold closing (e.g. the positive X-axis direction) is referred to as the "forward direction", and the direction of movement of the movable plate 120 during mold opening (e.g. the negative X-axis direction) is referred to as the "reverse direction".

[0047] The ejector 200 is attached to the movable plate 120 and moves forwards and backwards together with the movable plate 120. The ejector 200 comprises one or more ejector rods 210, which eject a molded product from the molded part 800, and a drive mechanism 220, which moves the ejector rod 210 in the directions of movement (the X-axis direction) of the movable plate 120.

[0048] Each ejector rod 210 is arranged in a through-hole of the movable plate 120, allowing it to move forwards and backwards. The front end of the ejector rod 210 contacts an ejector plate 826 of the movable mold 820. The front end of the ejector rod 210 can be connected to or disconnected from the ejector plate 826.

[0049] The drive mechanism 220, for example, comprises an ejector motor 221 and a motion conversion mechanism that converts the rotary motion of the ejector motor 221 into the linear motion of the ejector rod 210. The motion conversion mechanism includes a spindle shaft and a spindle nut that fits together with the spindle shaft. Balls or rollers can be arranged between the spindle shaft and the spindle nut.

[0050] The ejector 200 performs an ejection operation under the control of the controller 700. During the ejection operation, the ejector rods 210 are moved forward from a ready position to an ejection position at a set speed to advance the ejector plate 826 and eject a molded product. Afterwards, the ejector motor 221 is driven to move the ejector rods 210 backward at a set speed to return the ejector plate 826 to its initial ready position.

[0051] The position and speed of movement of the ejector rods 210 are detected, for example, using an ejector motor encoder. The ejector motor encoder 221 detects the rotation of the ejector motor to transmit a signal indicating the detection results to the controller 700. An ejector rod position detector, which detects the position of the ejector rods 210, and an ejector rod speed detector, which detects the speed of movement of the ejector rods 210, are not limited to the ejector motor encoder, and common detectors can be used.

[0052] The ejector motor 221 includes a built-in motor brake 222. The motor brake 222 operates to stop the rotation of a motor shaft of the ejector motor 221. The motor brake 222 is, for example, a non-excitation brake and operates when the power supply is interrupted. (Injection part)

[0053] In contrast to the description of the form-closing / clamping part 100 and the ejector 200, in the description of the injection part 300 the direction of movement of a screw 330 during filling (e.g. the negative X-axis direction) is referred to as the “forward direction”, and the direction of movement of the screw 330 during metering (e.g. the positive X-axis direction) as the “reverse direction”.

[0054] The injection part 300 is installed on a movable base 301, and the movable base 301 is arranged so that it is movable forwards and backwards relative to the injection part frame 920. The injection part 300 is arranged so that it is movable towards and away from the molded part 800. The injection part 300 contacts the molded part 800 to fill the cavity 801 within the molded part 800 with a molding material metered in a cylinder 310.The injection part 300 comprises, for example, the cylinder 310, which heats a molding material, a nozzle 320, which is provided at the front end of the cylinder 310, the screw 330, which is arranged in the cylinder 310 so as to be movable and rotatable forwards and backwards, a metering motor 340, which rotates the screw 330, an injection motor 350, which moves the screw 330 forwards and backwards, and a load detector 360, which detects a load transmitted between the injection motor 350 and the screw 330.

[0055] The cylinder 310 heats a molding material that is fed into the interior through a feed opening 311. Examples of the molding material include resin. The molding material is, for example, formed into pellets and is fed into the feed opening 311 in a solid state. The feed opening 311 is located in a rear section of the cylinder 310. A cooler 312, such as a water-cooled cylinder, is provided on the outer cylinder surface of the rear section of the cylinder 310. Heaters 313, such as a belt heater, and temperature detectors 314 are provided upstream of the cooler 312 on the outer cylinder surface of the cylinder 310.

[0056] The cylinder 310 is divided into several zones along its axial direction (e.g., the X-axis direction). Each zone is equipped with a heater 313 and a temperature detector 314. A temperature is set for each zone, and the controller 700 controls the heater 313 so that the temperature detected by the temperature detector 314 becomes the set temperature.

[0057] The nozzle 320 is located at the front end of the cylinder 310 to be pressed against the molded part 800. The heater 313 and the temperature detector 314 are located at the periphery of the nozzle 320. The controller 700 controls the heater 313 so that the detected temperature of the nozzle 320 becomes the set temperature.

[0058] The screw 330 is arranged in the cylinder 310 to be rotatable and move forwards and backwards. As the screw 330 rotates, a molding material is conveyed forwards along the helical groove of the screw 330. The molding material is gradually melted by heat from the cylinder 310 as it is conveyed forwards. While the molding material, in liquid form, is conveyed forwards on the screw 330 to accumulate at the front of the cylinder 310, the screw 330 is moved backwards. Subsequently, as the screw 330 moves forwards, the molding material accumulated in liquid form in front of the screw 330 is injected through the nozzle 320 into the molded part 800.

[0059] A non-return valve ring 331 is attached to a front section of the screw 330 in such a way as to be movable forwards and backwards as a non-return check valve in order to prevent the backflow of the molding material from the front to the rear of the screw 330 when the screw 330 is pushed forwards.

[0060] When the screw 330 is moved forward, the backflow prevention ring 331 is pushed backward by the pressure of the mold material in front of the screw 330 to enter a closed position relative to the screw 330 (see Fig. 2) to move, which closes the flow channel of the molding material, thereby preventing the backflow of the molding material accumulated in front of the screw 330 in the reverse direction.

[0061] When the screw 330 is rotated, the non-return ring 331 is pushed forward by the pressure of the molding material conveyed along the spiral groove of the screw 330, in order to move forward relative to the screw 330 into an open position (see Fig. 1) to move, which opens the flow channel of the molding material. As a result, the molding material is conveyed in front of screw 330.

[0062] The backflow prevention ring 331 can be of a rotating type, which rotates together with the screw 330, or of a non-rotating type, which does not rotate together with the screw 330.

[0063] The injection part 300 can include a drive source that moves the non-return ring 331 forward and backward relative to the screw 330 between the open position and the closed position.

[0064] The metering motor 340 rotates the screw 330. The drive source that rotates the screw 330 is not limited to the metering motor 340 and can, for example, be a hydraulic pump.

[0065] The injection motor 350 moves the screw 330 forwards and backwards. A motion conversion mechanism is provided between the injection motor 350 and the screw 330, which converts the rotary motion of the injection motor 350 into the linear motion of the screw 330. The motion conversion mechanism includes, for example, a spindle shaft and a spindle nut that fits the spindle shaft. Balls or rollers may be provided between the spindle shaft and the spindle nut. The drive source that moves the screw 330 forwards and backwards is not limited to the injection motor 350 and could, for example, be a hydraulic cylinder.

[0066] The injection motor 350 includes a built-in motor brake 352. The motor brake 352 operates to stop the rotation of a motor shaft of the injection motor 350. The motor brake 352 is, for example, a non-excitation brake and operates when the energy (signal) supply is stopped.

[0067] The load detector 360 detects a load transmitted between the injection motor 350 and the screw 330. The detected load is converted into pressure in the control unit 700. The load detector 360 is located in the load transmission path between the injection motor 350 and the screw 330 to detect a load exerted on it.

[0068] The load detector 360 transmits a signal of the detected load to the controller 700. The load detected by the load detector 360 is converted into a pressure exerted between the screw 330 and the molding material and is used to control and monitor pressure received by the screw 330 from the molding material, back pressure against the screw 330, pressure exerted by the screw 330 on the molding material, and the like.

[0069] A pressure detector that detects the pressure of a molding material is not limited to the 360 ​​load detector, and a common detector can be used. For example, a nozzle pressure sensor or a cavity pressure sensor can be used. The nozzle pressure sensor is located in the 320 nozzle.

[0070] The injection unit 300 performs processes such as a dosing process, a filling process, and a dwell process under the control of the controller 700. The filling process and the dwell process can be collectively referred to as the "injection process".

[0071] In the metering process, the metering motor 340 is driven to rotate the screw 330 at a set speed, conveying a molding material forward along the helical groove of the screw 330. This gradually melts the molding material. When the molding material, in liquid form, is conveyed in front of the screw 330 to accumulate in the front part of the cylinder 310, the screw 330 is moved backward. The rotational speed of the screw 330 is detected by a metering motor encoder 341 or the like. The metering motor encoder 341 detects the rotation of the metering motor 340 and transmits a signal indicating the detection results to the controller 700. A screw rotational speed detector that detects the rotational speed of the screw 330 is not limited to the metering motor encoder 341, and a common detector can be used.

[0072] During the metering process, the injection motor 350 can be driven to limit a sudden reverse movement of the screw 330 by applying a set back pressure to the screw 330. This back pressure is detected, for example, using the load detector 360. When the screw 330 is moved backward into a metering end position and a predetermined amount of molding material has accumulated in front of the screw 330, the metering process is complete.

[0073] The position and rotational speed of the 330 screw during the metering process are set collectively as a series of parameters. For example, a metering start position, a rotational speed switching position, and a metering end position are set. These positions, arranged in this order in reverse from the front, represent the start and end points of sections for which the rotational speed is set. The rotational speed is set section by section. There can be one or more rotational speed switching positions. The rotational speed switching position is not mandatory. Additionally, a back pressure is set for each section.

[0074] During the filling process, the injection motor 350 is driven to move the screw 330 forward at a set speed to fill the cavity 801 within the molded part 800 with the molding material that has accumulated in liquid form in front of the screw 330. The position and speed of the screw 330 are detected, for example, using an injection motor encoder 351. The injection motor encoder 351 detects the rotation of the injection motor 350 and transmits a signal indicating the detection results to the controller 700. When the position of the screw 330 reaches a set position, the filling process switches to the dwell phase (so-called V / P changeover). The position at which the V / P changeover occurs can be referred to as the "V / P changeover position". The set movement speed of the 330 screw can be changed according to the position of the 330 screw, time, and the like.

[0075] The position and speed of screw 330 during the filling process are set collectively as a series of preset conditions. For example, a filling start position (also referred to as the "injection start position"), a speed switching position, and the V / P switching position are set. These positions, arranged in this order in the forward direction from the rear, represent the start and end points of sections for which the speed is set. The speed is set section by section. There can be one or more speed switching positions. The speed switching position does not have to be set.

[0076] The upper limit of the screw pressure 330 is set for each section for which the screw speed 330 is set. The screw pressure 330 is detected by the load detector 360. If the screw pressure 330 is less than or equal to a set pressure, the screw 330 moves forward at a set speed. If the screw pressure 330 exceeds the set pressure, the screw 330 moves forward at a speed lower than the set speed, so that the screw pressure 330 is less than or equal to the set pressure, for mold protection.

[0077] During the filling process, once the screw 330 reaches the V / P switching position, it can be temporarily stopped at the V / P switching position, and the V / P switching can then be performed. Immediately before the V / P switching, instead of being stopped, the screw 330 can be moved very slowly forward or backward. A screw position detector, which detects the position of the screw 330, and a screw speed detector, which detects the speed of the screw 330, are not limited to the injection motor encoder 351, and common detectors can be used.

[0078] During the residence process, the injection motor 350 is driven to push the screw 330 forward, maintaining the pressure of the molding material at the front end of the screw 330 (hereinafter also referred to as "residence pressure") at a set pressure and forcing the molding material remaining in the cylinder 310 toward the molded part 800. It is possible to compensate for a lack of molding material due to cooling shrinkage within the molded part 800. The residence pressure is detected, for example, using the load detector 360. The set value of the residence pressure can be changed according to the time elapsed since the start of the residence process or similar factors. Two or more values ​​can be set for each of the residence pressure and residence time for maintaining the residence pressure during the residence process, and the residence pressure and residence time can be set collectively as a set of predefined conditions.

[0079] During the residence process, the molding material in the cavity 801 within the molded part 800 is gradually cooled so that the inlet of the cavity 801 is filled with the solidified molding material when the residence process is complete. This condition, referred to as the "gate seal," prevents the backflow of the molding material from the cavity 801. After the residence process, the cooling process is initiated. During the cooling process, the molding material in the cavity 801 solidifies. The metering process can be performed during the cooling process to reduce the mold cycle time.

[0080] The injection unit 300, which according to the present embodiment is of an inline screw type, can be of a screw pre-plasticizing type. According to the screw pre-plasticizing injection unit, a molding material molten in a plasticizing cylinder is fed to an injection cylinder, and the molding material is injected from the injection cylinder into a molded part. In the plasticizing cylinder, a screw is arranged so that it is rotatable and not movable forwards or backwards, or a screw is arranged so that it is rotatable and movable forwards and backwards. In the injection cylinder, a plunger piston is arranged so that it is movable forwards and backwards.

[0081] Furthermore, the injection part 300, which according to the present embodiment is of a horizontal type, in which the axial direction of the cylinder 310 is horizontal, can be of a vertical type, in which the axial direction of the cylinder 310 is vertical. A form-locking / clamping part combined with the injection part 300 of a vertical type can be of a horizontal type or of a vertical type. Likewise, a form-locking / clamping part combined with the injection part 300 of a horizontal type can be of a horizontal type or of a vertical type. (Moving part)

[0082] In the description of the moving part 400, similar to the description of the injection part 300, the direction of movement of the screw 330 during filling (e.g. the negative X-axis direction) is referred to as the "forward direction", and the direction of movement of the screw 330 during metering (e.g. the positive X-axis direction) is referred to as the "reverse direction".

[0083] The moving part 400 moves the injection part 300 towards and away from the molded part 800. Furthermore, the moving part 400 presses the nozzle 320 against the molded part 800 to generate nozzle contact pressure. The moving part 400 comprises a hydraulic pump 410, a motor 420, which serves as a drive source, and a hydraulic cylinder 430, which serves as a hydraulic actuator.

[0084] The hydraulic pump 410 comprises a first port 411 and a second port 412. The hydraulic pump 410, which is a bidirectional rotary pump, reverses the direction of rotation of the motor 420 to draw in hydraulic fluid (e.g., oil) from either the first port 411 or the second port 412 and to discharge hydraulic fluid from either the first port 411 or the second port 412, thereby generating hydraulic pressure. The hydraulic pump 410 can draw in hydraulic fluid from a tank and discharge hydraulic fluid from either the first port 411 or the second port 412.

[0085] Motor 420 causes hydraulic pump 410 to operate. Motor 420 drives hydraulic pump 410 with a direction of rotation and torque corresponding to a control signal from controller 700. Motor 420 can be an electric motor or an electric servo motor.

[0086] The hydraulic cylinder 430 comprises a cylinder body 431, a piston 432, and a piston rod 433. The cylinder body 431 is attached to the injection part 300. The piston 432 divides the interior of the cylinder body 431 into a front chamber 435, which serves as a first chamber, and a rear chamber 436, which serves as a second chamber. The piston rod 433 is attached to the stationary plate 110.

[0087] 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. Hydraulic fluid discharged from the first port 411 is supplied to the front chamber 435 via the first flow channel 401 to push the injection element 300 forward. The injection element 300 is moved forward to press the nozzle 320 against the stationary form 810. The front chamber 435 acts as a pressure chamber, generating the nozzle contact pressure 320 with the pressure of the hydraulic fluid supplied by the hydraulic pump 410.

[0088] 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. Hydraulic fluid discharged from the second port 412 is supplied via the second flow channel 402 to the rear chamber 436 of the hydraulic cylinder 430 to push the injection element 300 backward. The injection element 300 is moved backward to separate the nozzle 320 from the stationary form 810.

[0089] According to the present embodiment, the moving part 400 comprises the hydraulic cylinder 430. However, the present disclosure is not limited thereto. For example, instead of the hydraulic cylinder 430, an electric motor and a motion conversion mechanism that converts the rotary motion of the electric motor into the linear motion of the injection part 300 can be used. (Steering)

[0090] The controller 700, which is built, for example, from a computer, comprises a central processing unit (CPU) 701, a storage medium 702 such as memory, an input interface (I / F) 703, an output interface (I / F) 704, and a communication interface 705, as shown in Fig. 1 and Fig. Figure 2 illustrates this. The controller 700 performs various control functions by instructing the CPU 701 to execute one or more programs stored in the memory medium 702. Furthermore, the controller 700 receives an external signal at the input interface 703 and transmits a signal to the outside at the output interface 704.

[0091] The 700 control system repeatedly produces a molded product by repeatedly executing processes such as the dosing process, the mold closing process, the pressurization process, the mold clamping / closing process, the filling process, the dwell process, the cooling process, the pressure release process, the mold opening process, and the ejection process. A series of operations to obtain a molded product, for example, the operations from the start of one dosing process to the start of the next, can be referred to as a "shot" or "mold cycle." Furthermore, the time required for a shot can be referred to as the "mold cycle time" or "cycle time."

[0092] A mold cycle comprises, for example, the dosing process, the mold closing process, the pressurization process, the mold clamping / closing process, the filling process, the dwell process, the cooling process, the pressure release process, the mold opening process, and the ejection process, in that order. The sequence here is the order in which the processes are started. The filling process, the dwell process, and the cooling process are executed during the mold clamping / closing process. The start of the mold clamping / closing process can coincide with the start of the filling process. The completion of the pressure release process coincides with the start of the mold opening process.

[0093] Several processes can be executed simultaneously to reduce the mold cycle time. For example, the dosing process can be performed during the cooling process of the previous mold cycle or during the mold closing / clamping process. In such a case, the mold closing process can be performed at the start of the mold cycle. Furthermore, the filling process can be started during the mold closing process. Additionally, the ejection process can be started during the mold opening process. If an on / off valve is provided that opens and closes the flow path of nozzle 320, the mold opening process can be started during the dosing process. This is because, even if the mold opening process is started during the dosing process, no mold material will exit the nozzle 320 as long as the on / off valve closes the flow path of nozzle 320.

[0094] A mold cycle may include one or more processes other than the dosing process, the mold closing process, the pressurizing process, the mold closing / clamping process, the filling process, the dwell process, the cooling process, the pressure relief process, the mold opening process, and the ejection process.

[0095] For example, before the dosing process begins, a pre-dosing back-suction process can be performed after the dwell process is complete to move the screw 330 backwards into a preset dosing start position. This makes it possible to reduce the pressure of the molding material accumulated in front of the screw 330 before the start of the dosing process and to prevent a sudden backward movement of the screw 330 at the start of the dosing process.

[0096] Furthermore, before the filling process begins, a post-dosing suction process can be performed to move the screw 330 backwards into a preset filling start position (also referred to as the "injection start position"). This reduces the pressure of the molding material accumulated in front of the screw 330 before the filling process begins and prevents the molding material from escaping the nozzle 320 before the filling process starts.

[0097] The controller 700 is connected to an operating device 750, which receives user input, and to a display device 760, which displays a screen. The operating device 750 and the display device 760 can, for example, be constructed as a single unit from a touchscreen 770. The touchscreen 770, serving as the display device 760, displays a screen under the control of the controller 700. For example, information such as the settings of the injection molding machine 10 and its current status can be displayed on the touchscreen 770. The touchscreen 770 displays a screen area where user input can be received. For example, operating elements such as buttons and input fields for receiving user input can be displayed on the screen area of ​​the touchscreen 770.The touchscreen 770, serving as the operating device 750, detects user input on the screen and sends a corresponding signal to the controller 700. This allows the user, for example, to enter settings (including setpoints) for the injection molding machine 10 by operating the controls provided on the screen while reviewing the information displayed. Furthermore, the user can cause the injection molding machine 10 to perform corresponding operations by operating the controls provided on the screen. These operations of the injection molding machine 10 can include, for example, the operation (including stopping) of the mold clamping / closing part 100, the ejector 200, the injection part 300, the movement part 400, and the like.Furthermore, the processes of the injection molding machine 10 can, for example, include switching the screen displayed on the touchscreen 770 serving as the display device 760.

[0098] The operating device 750 and the display device 760 of the present embodiment, which are described as being integrated into the touchscreen 770, can be provided separately. Furthermore, two or more operating devices 750 can be provided. The operating device 750 and the display device 760 are arranged on the operating side (the negative side in the Y-axis direction) of the form-closing / clamping part 100 (more specifically, the stationary plate 110). (Safety features)

[0099] As shown by long-dashed and double-short-dashed lines in Fig. 1 and Fig. As shown in Figure 2, the injection molding machine 10 comprises a housing 940 that covers the mold clamping / closing part 100, the ejector 200, and the molded part 800. The housing 940 has a protective function to prevent a user of the injection molding machine 10 from coming into contact with the molded part 800 or the like during injection molding. The housing 940 can cover the components up to the injection part 300 or can cover the entire injection molding machine 10.

[0100] For example, the housing 940 is formed in a rectangular shape (box shape) and is attached to the top of the frame 900 (the form-closing / clamping frame 910). An opening (not shown) is provided in the side surface of the housing 940 in the positive X-axis direction, through which the cylinder 310 and the nozzle 320 of the injection part 300 can move forwards and backwards.

[0101] The enclosure 940 includes one or more safety doors 941 that can be opened and closed by a user. Fig. 1 and Fig. Figure 2 illustrates an example where the safety door 941 is located on the side of the housing 940 in the positive Y-axis direction (the front of the drawing sheet). However, there is no particular restriction on the location of the safety door 941, and it can be located on the side of the housing 940 in the negative Y-axis direction, in the negative X-axis direction, or on the top of the housing 940 in the positive Z-axis direction. The safety door 941 can be of a one-way opening type, a sliding type, or a two-way opening type.

[0102] The injection molding machine 10 includes an open / close detector 942 configured to detect the open / close state of the safety door 941. The type of open / close detector 942 according to the present embodiment is, for example, a mechanical switch configured to turn on or off a current output according to the open / close state of the safety door 941. The present embodiment does not intend to limit the type of open / close detector 942, and an optical sensor or the like may be used.

[0103] The opening / closing detector 942 is communicatively connected to the control unit 700 and a programmable logic controller (PLC) 710, which is provided in an interior 922 on the vertical underside of the injection part frame 920, and is configured to transmit a signal indicating the opening / closing status of the safety door 941.

[0104] The PLC 710 is a computer configured to execute a process according to a procedure defined in a previously stored program, and is an example of the digital circuit for ensuring the safety of the injection molding machine 10.

[0105] The present embodiment is an example where the PLC 710 is a safety PLC used to construct a safety control system compliant with the international safety standard (ISO 13849 or IEC 61508). For example, an IC chip that has received certification according to the safety standard is used as a computational part 720 of the PLC 710. In the PLC 710 according to the present embodiment, a memory area for handling safety information and a memory area for processing non-safety information are separated. Therefore, even if a malfunction occurs in the memory area for processing non-safety information, it is possible to suppress any impact on the safety information.The present embodiment describes an example where the safety PLC is used as the PLC 710, but restriction to the embodiment using the safety PLC is not intended. It is possible to use a general-purpose PLC or a controller using a different processor (e.g., CPU, GPU, ASIC, FPGA, or the like).

[0106] In the PLC 710, an input part 731, an output part 732, and the like, described below, are multiplexed and duplicated. Furthermore, the PLC 710 performs self-diagnostics of its configuration using a self-test function, thus preventing the injection molding machine 10 process from continuing if an abnormality occurs in the PLC 710.

[0107] Fig. Figure 3 is a diagram illustrating an example of the electrical configuration of the PLC 710 according to the present embodiment. As shown in Fig. As shown in Figure 3, the PLC 710 comprises the input part 731, the output part 732, the calculation part 720 and a memory 730.

[0108] The control unit 720 is designed to control the operations of the PLC 710 and is configured to perform safety controls for the injection molding machine 10 according to a previously created program. For example, the control unit 720 controls the moving part to stop it when a predetermined event occurs.

[0109] Memory 730 is a memory area for storing data (data signals) used by the calculation unit 720.

[0110] The input part 731 is connected to at least one input device selected from various sensors, switches and buttons provided in the injection molding machine 10, and is configured to receive a signal output by the input device.

[0111] For example, the input unit 731 receives a signal indicating a detection result from the open / close detector 942, which detects the open / closed state of the safety door 941. The input unit 731 also receives a signal indicating whether an emergency stop switch 751 is pressed or not. Furthermore, the input unit 731 receives a signal indicating a detection result from another safety sensor 752, which is provided in the injection molding machine 10.

[0112] Output part 732 is connected to a mechanism configured to control the moving part provided in injection molding machine 10 and is configured to output a signal to this mechanism. The signal output by output part 732 is, for example, a 24 V voltage signal.

[0113] For example, the output part 732 can output the 24 V voltage signal to a motor driver 221A, which is configured to drive the ejector motor 221. According to the present embodiment, the output part 732 determines whether or not the 24 V voltage signal is output according to the program executed by the computation part 720.

[0114] The output unit 732 can output the 24 V voltage signal to the motor brake 222, which is configured to stop the ejector motor 221. According to the present embodiment, the output unit 732 determines whether or not the 24 V voltage signal is output according to the program executed by the computation unit 720.

[0115] The in Fig. Figure 3, PLC 710, illustrates a mechanism configured to control the ejector motor 221, but the control target of PLC 710 is not limited to the ejector motor 221. As long as the control target of PLC 710 is a mechanism configured to drive moving parts provided in the injection molding machine 10, the control target of PLC 710 can be the injection motor 350, the mold thickness adjustment motor 183, and the mold closing / clamping motor 160. Furthermore, the control target of PLC 710 can be an injection molding machine motion motor (not shown) configured to move the injection molding machine 10 away from the frame.

[0116] For example, the output part 732 can output the 24 V voltage signal to a motor driver configured to drive the injection motor 350, and to the motor brake 352 configured to stop the injection motor 350.

[0117] Furthermore, the output part 732 can output the 24 V voltage signal to a motor driver configured to drive the mold thickness adjustment motor 183, and to the motor brake 186 configured to stop the mold thickness adjustment motor 183.

[0118] In addition, the output part 732 can output the 24 V voltage signal to a motor driver configured to drive the form-closing / clamping motor 160, and to the motor brake 162 configured to stop the form-closing / clamping motor 160.

[0119] The following describes a method by which the output part 732 controls the ejector motor 221. A similar control can be implemented for the injection motor 350, the mold thickness adjustment motor 183, the mold closing / clamping motor 160, and the injection molding machine motion motor (not shown), and therefore a description of these is omitted.

[0120] For example, in response to receiving a signal indicating the detection of the opening of the safety door 941 (an example of a predetermined event) by the open / close detector 942 (an example of a detector) via the input unit 731 while the injection molding machine 10 is in operation, the computation unit 720 controls the output of a signal (24 V voltage signal) (an example of a first signal) to the motor driver 221A to interrupt the power supply to the ejector motor 221, and controls an output of a signal (24 V voltage signal) (an example of a second signal) to the motor brake 222 to start braking the ejector motor 221.The processing unit 720, according to the present embodiment, controls the output of the signal for performing a power interruption (an example of a first signal) and the output of the signal for starting the brakes of the ejector motor 221 (an example of a second signal) such that the control of the output of the signal for starting the brakes of the ejector motor 221 is performed after the control of the output of the signal for performing a power interruption. Controlling the output of the signal for starting a power interruption is, for example, stopping the 24 V voltage signal, and controlling the output of the signal for starting the brakes is, for example, stopping the 24 V voltage signal. In the present embodiment, controlling the output of the signal is stopping the voltage signal. However, what constitutes controlling the output of the signal can be determined according to the embodiment.For example, controlling the output of the signal could be an output of a stop signal for power interruption, an output of a control signal to drive the motor brake, or the like.

[0121] To stop a moving part (e.g., an ejector rod, a moving mold, or the like) in an injection molding machine, the power interruption for an actuator configured to drive this moving part and the braking control by a brake configured to stop the actuator are typically performed by separate controllers. When the power interruption and braking control are performed by different controllers, the intended timing is essentially ensured by constructing an analog delay circuit, such as a relay substrate. However, the delay time varies between components, and thus the delay time can become excessively long.

[0122] In this way, when the moving part is stopped by the safety function, there is typically a time delay in the brake control, which must be performed after the power interruption. If the time between the power interruption and the start of the braking process is set to be long, the stopping of the moving part is delayed. This can cause stress on the components of the injection molding machine, especially the components of the molded part, or on the molded products themselves.

[0123] If the time between the power interruption and the start of braking by the brake is set to be short, a situation can arise where, due to a timing discrepancy, the power interruption for the actuator configured to actuate the moving part and the start of braking by the brake configured to stop the actuator are reversed in terms of the intended timing. In this case, the power interruption occurs after the brake control, and as a result, the brake control is performed while the actuator is still operating. This causes wear due to brake slippage.

[0124] In light of the foregoing, in the present embodiment, the power interruption and brake control are performed by the PLC 710. That is, by using the single PLC 710, when an event occurs that requires the moving part to be stopped (an example of a predetermined event), the power interruption and brake control can be managed so that the brake control is performed after the power interruption. The PLC 710 controls signals to ensure the correct sequence of power interruption and braking, thereby improving safety.

[0125] Fig. Figure 4 is a functional configuration diagram illustrating a main configuration of the controller 700 and the PLC 710 according to the present embodiment. Fig. Figure 4 illustrates the components of the control unit 700 and the PLC 710 of the injection molding machine 10 as functional blocks. The in Fig. The three function blocks shown are conceptual and do not need to be physically configured as depicted. All or some of the function blocks can be functionally or physically distributed or integrated as desired. Processing functions executed in the function blocks on the 700 controller are carried out, in whole or in part, as desired, by one or more programs running on the 701 CPU. Alternatively, the function blocks can be implemented as hardware using wired logic.

[0126] As in Fig. As shown in Figure 4, the CPU 701 of the controller 700, for example, includes an input processor 711 and a speed control unit 712.

[0127] The input processor 711 is configured to receive an input signal from a sensor provided in the injection molding machine 10, indicating a detection result received from the sensor. For example, the input processor 711 receives an input signal from the open / close detector 942 indicating the open / close status of the safety door 941.

[0128] The speed control unit 712 is configured to control the speed of the actuator via the motor driver based on the signal received from the input processor 711. For example, the speed control unit 712 issues a command to the motor driver 221A to reduce the speed of the ejector motor 221 when the safety door 941 is detected as open according to the signal received from the input processor 711.

[0129] The processing functions executed in the function blocks of the PLC 710 are carried out in whole or in part, as desired, by one or more programs running in the calculation unit 720. Alternatively, the function blocks can be implemented as hardware using wired logic.

[0130] As in Fig. As shown in Figure 4, the calculation part 720 of the PLC 710 includes, for example, the input processor 721, a measuring part 722, a driver control part 723 and a brake control part 724.

[0131] The input processor 721 is configured to receive an input signal from a sensor provided in the injection molding machine 10, indicating a detection result received from the sensor. For example, the input processor 721 receives an input signal from the open / close detector 942 indicating the open / close status of the safety door 941.

[0132] When a predetermined event is detected based on the signal received by the input processor 721, the measuring element 722 measures a time interval from the occurrence of the event. For example, if the opening of the safety door 941 is detected, the measuring element 722 measures a time interval from the opening of the safety door 941. The present embodiment does not intend to limit the occurrence of the predetermined event to the case in which the safety door 941 is opened. The occurrence of the predetermined event could, for example, be a case in which pressing of the emergency stop switch 751 is detected, or a case in which the other safety sensor 752 detects an abnormal condition.

[0133] Upon detection of the occurrence of the predetermined event, which serves as a trigger, the driver control unit 723 executes a control action to stop the output of the 24 V voltage signal, thus interrupting the power supply to the actuator provided in the injection molding machine 10 after the waiting period (an example of a second time) has elapsed, based on the measurement result obtained from the measuring unit 722. For example, the waiting period (an example of a second time) since the detection of the occurrence of the predetermined event is 100 ms since the opening of the safety door 941.

[0134] Upon detection of the occurrence of the predetermined event, which serves as a trigger, the brake control unit 724 executes a control action to stop the output of the 24 V voltage signal to the motor brake. This action initiates brake control for the actuator provided in the injection molding machine 10. The delay time is calculated based on the measurement result obtained from the measuring unit 722. The delay time (an example of a first delay) is the time that has elapsed since the output of the 24 V voltage signal to initiate the power interruption was stopped and is, for example, set to 50 ms. That is, when 150 ms, i.e., the sum of the waiting time and the delay time that has elapsed since the occurrence of the predetermined event was detected, the control action is executed to stop the output of the 24 V voltage signal to the motor brake.

[0135] The present embodiment was described based on an example where the brake control is initiated after the sum of the waiting time and the deceleration time has elapsed, with the detection of the occurrence of the predetermined event serving as a trigger. However, the present embodiment does not intend to restrict the trigger for initiating the measurement of the detection of the occurrence of the predetermined event to the time at which the occurrence of the predetermined event is detected. For example, it is possible to use a method where the brake control is initiated after the deceleration time has elapsed, with the execution of the energy interruption, which serves as a trigger.

[0136] Fig. Figure 5 is a time diagram of the energy interruption and brake control by the motor brake 222, which are executed when the safety door 941 is opened on the injection molding machine 10 according to the present embodiment.

[0137] As seen through line 1501 in Fig. As shown in Figure 5, the safety door 941 is opened at time t1. The open / close detector 942 sends a signal to the controller 700 and the PLC 710 indicating that the safety door 941 is open. At the time the input processor 711 of the controller 700 receives this signal, the speed control unit 712 starts the control to reduce the speed of the actuator (e.g., the ejector motor 221) for the motor driver (e.g., the motor driver 221A).

[0138] In PLC 710, measuring unit 722 measures the time elapsed since the opening of safety door 941 at the moment input processor 711 receives this signal. At time t2, when the waiting time (e.g., 100 ms) since time t1 has elapsed, driver control unit 723 stops outputting the 24 V voltage signal and initiates the power interruption to cut off the power supply to the actuator (e.g., the ejector motor 221) in injection molding machine 10. Therefore, as indicated by line 1502, the power interruption state is active at time t2.

[0139] Furthermore, at time t3, when the delay time (e.g., 50 ms) has elapsed since time t2, the brake control unit 724 of the PLC 710 stops outputting the 24 V voltage signal and initiates brake control via the brake provided in the injection molding machine 10 (e.g., the motor brake 222 provided in the ejector motor 221). Therefore, as indicated by line 1503, the motor brake 222 switches from not applied to braking start at time t3.

[0140] The PLC 710, according to the present embodiment, first stores the waiting time and delay time in a memory section (not shown). When a program is executed in the computation section 720, the control described above is performed with reference to the waiting time and delay time stored in the memory section. Alternatively, the waiting time and delay time can be set by a user.

[0141] In the present embodiment, the power interruption and braking by the motor brake 222 are controlled sequentially, i.e., braking is performed after the power interruption, thus reducing wear on the motor brake 222. In this embodiment, the delay time between the power interruption and the start of braking by the motor brake 222 is set to be as short as possible, while the power interruption and braking are performed sequentially. That is, the present embodiment does not intend to limit the delay time to 50 ms, as long as the time between the power interruption and braking is set to be as short as possible, while the power interruption and braking are performed sequentially.

[0142] In this embodiment, the controller 700 also performs control operations to reduce the speed of the ejector motor 221 at the moment the safety door 941 is opened, and the power interruption by the PLC 710 is carried out after the waiting period since the detection of the opening has elapsed. If the power interruption is carried out after the speed of the ejector motor 221 has been reduced, it is possible to decrease the movement speed of the ejector 200 after the power interruption and to reduce the wear rate of the motor brake 222 due to the subsequent brake control.

[0143] Even if, in the present embodiment, the controller 700 performs the speed reduction control, the PLC 710 performs the power interruption and brake control via the brake according to the procedure described above. That is, even if the controller 700 does not operate as intended, the PLC 710 performs the power interruption and brake control via the brake, thereby stopping the ejector motor 221. Thus, according to the present embodiment, the PLC 710 performs the power interruption and brake control regardless of whether the controller 700 reduces the speed of the ejector motor 221 or not, thereby improving the certainty of stopping the ejector motor 221. Therefore, it is possible to achieve an improvement in safety.

[0144] The present embodiment was described based on an example in which the control by the controller 700 to reduce the speed of the ejector motor 221 is combined with the power interruption by the PLC 710 and the brake control by the brake. However, the present embodiment does not intend to impose any restrictions on the way in which the control by the controller 700 to reduce the speed of the ejector motor 221 is combined with the power interruption by the PLC 710 and the brake control by the brake. For example, only the power interruption by the PLC 710 and the brake control by the brake can be performed, without the control by the controller 700 to reduce the speed of the ejector motor 221.

[0145] The present embodiment was described based on an example in which a configuration for performing the power interruption (the motor driver and the actuator) and a configuration for performing the brake control (the motor brake) are provided separately. However, the present embodiment does not intend any limitation to the example in which a configuration for performing the power interruption and a configuration for performing the brake control are provided separately. The configuration for performing the power interruption can be integrated with the configuration for performing the brake control. (Further embodiment)

[0146] One embodiment relates to the case in which the PLC 710 directly controls the motor brake 222 and the motor driver (e.g., the motor driver 221A). However, this embodiment does not intend to impose any restrictions on the way in which the PLC 710 directly controls the motor brake 222 and the motor driver (e.g., the motor driver 221A). Against this background, another embodiment describes a case in which control is performed via a relay.

[0147] Fig. Figure 6 is a diagram illustrating an example of an electrical configuration of the PLC 710 according to the present embodiment. As shown in Fig.As shown in Figure 6, the PLC 710 comprises, as in one embodiment, the input part 731, the output part 732, the calculation part 720, and the memory 730. In the present embodiment, the same reference numerals are assigned to the same components as in one embodiment, and their description is omitted.

[0148] In the present embodiment, a relay 1601 is provided between: the PLC 710; and the ejector motor 221 and the motor driver 221A. Furthermore, a relay 1602 is provided between the PLC 710 and the motor brake 222.

[0149] The motor driver 221A is connected to a 24 V power supply 1603 via the relay 1601. When the PLC 710 outputs the 24 V voltage signal, a current flows through a coil 1601A in the relay 1601, generating a magnetic field. When an iron piece (not shown) contacts a relay due to the magnetic field, power is supplied to the motor driver 221A from the 24 V power supply 1603.

[0150] Furthermore, the motor brake 222 is connected to a 24 V power supply 1604 via the relay 1602. When the PLC 710 outputs the 24 V voltage signal, a current flows through a coil 1602A in the relay 1602, generating a magnetic field. When an iron piece (not shown) contacts a contact due to the effect of the magnetic field, energy is supplied from the 24 V power supply 1604 to the motor brake 222.

[0151] This means that even if relays 1601 and 1602 are provided as in the present embodiment, the PLC 710 can control the motor drive 221A and the motor brake 222 by performing the same control as in one embodiment.

[0152] The PLC 710 according to the present embodiment is connected to the motor driver 221A and the motor brake 222 via relays 1601 and 1602. Therefore, if an overcurrent occurs in the motor driver 221A, the motor brake 222, or the like, relays 1601 and 1602 can suppress the effect of the overcurrent on the PLC 710. This allows for an improvement in the safety of the PLC 710. (Modification example)

[0153] In the embodiments described above, the injection molding machine 10 is a horizontal type machine. However, these embodiments do not intend to restrict the use of the injection molding machine 10 to the case where it is a horizontal type machine, and a vertical type machine can also be used. Therefore, a case where a vertical type machine is used is described.

[0154] The safety standard (ISO 20430 (JIS B6711)) stipulates that injection molding machines should prevent any movement caused by gravity. This means that, in a modification example where a vertical-type machine such as injection molding machine 10 is used, when a moving part that moves in the direction of gravity (e.g., mold opening and closing, mold thickness movement, or movement of the injection part) is actuated, a braking device (e.g., a motor brake) must prevent such gravity-induced movement.

[0155] If the energy interruption and the braking control by the brake, which is configured to stop the actuator, are performed by different controllers, it is further necessary to prevent the generation of a large amount of energy if there is a time difference between the energy interruption and the braking control by the brake. Therefore, the energy interruption and the braking control must be performed at appropriate times.

[0156] In this modification example, the PLC 710 sequentially performs the power interruption for the actuator configured to operate the moving part and the braking control via the motor brake during the movement of the vertically oriented moving part of the injection molding machine at predetermined times, as in the embodiments described above. This modification example can perform timing control with higher accuracy than when an analog delay circuit is used. Thus, it is possible to achieve an improvement in safety. <wirkungen>

[0157] By performing the control described above, the PLC 710, according to the embodiments and modification examples described above, can maintain the sequence of the power interruption for the actuator configured to actuate the moving part and the brake control to stop the actuator. Therefore, it is possible to suppress the power interruption that occurs after the brake control, thus reducing brake wear.

[0158] Furthermore, it is possible to control the timing at which the PLC 710 performs the power interruption and brake control. This can prevent stress on the components of the injection molding machine 10 caused by varying the timing of the brake control.

[0159] In the embodiments and modification example described above, the computing unit 720, configured as a digital circuit, performs the energy interruption and brake control according to a previously created program, and thus it is possible to perform timing control with higher accuracy than in the case where an analog delay circuit is used.

[0160] By using the safety PLC as PLC 710 according to the embodiments and modification example described above, the input part 731, the output part 732, and the like are furthermore multiplexed and duplicated, and the PLC 710 also performs self-diagnostics using a self-test function, thereby improving safety. In particular, the input part 731, the output part 732, and the like are multiplexed and duplicated, which improves the certainty of performing stop control of the moving part of the injection molding machine 10 according to a previously created program. Thus, it is possible to achieve an improvement in safety.

[0161] Although the embodiments of the PLC (an example of a controller) provided with the injection molding machine and the injection molding machine according to the present disclosure have been described above, the present disclosure is not limited to the embodiments described above and the like. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the stated claims. These naturally fall within the technical scope of the present disclosure. REFERENCE MARK LIST 10 injection molding machines 160 Locking / clamping motor 162 Engine brake 183 Mold thickness adjustment motor 186 Engine brake 221 Ejector motor 221A Motor drive 222 Engine brake 350 injection engine 352 Engine brake 700 control 701 CPU 711 Input processor 712 Speed ​​control part 710 PLC 720 Calculation part 721 Input processor 722 Measuring part 723 Driver control unit 724 Brake control unit 730 storage 731 Input section 732 Output section 751 Emergency stop switch 752 Additional safety sensor 940 cases 941 Security door 942 Opening / Closing Detector QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. 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

[0000] JP 2007-230113

[0002] < / wirkungen>

Claims

[1] Control system for an injection molding machine, the control system comprising: A digital circuit configured to control, in response to receiving a signal indicating the detection of a predetermined event from a detector provided on the injection molding machine, which includes a motor configured to supply energy to move a moving part and a brake for the motor, an output of a first signal to perform an energy interruption to interrupt the power supply to the motor and an output of a second signal to start braking by the brake, such that control of the output of the second signal occurs after control of the output of the first signal. [2] Control for the injection molding machine according to claim 1, wherein the digital circuit is configured to control the output of the second signal after a first time has elapsed following detection of the occurrence of the predetermined event. [3] Control for the injection molding machine according to claim 1, wherein the digital circuit is configured to control the output of the first signal after a second time has elapsed in response to detection of the occurrence of the predetermined event. [4] Injection molding machine, comprising: a motor configured to supply energy to move a moving part; a brake for the engine; and a controller comprising a digital circuit configured to respond to the receipt of a signal indicating the detection of a predetermined event, to output a first signal to perform a power interruption to cut off the power supply to the motor, and to output a second signal to initiate braking by the brake, such that the output of the second signal is controlled after the output of the first signal has been controlled. [5] Injection molding machine according to claim 4, wherein the motor is an ejector motor configured to drive an ejector provided in the injection molding machine, a mold closing / clamping motor configured to perform mold closing / clamping of a molded part provided in the injection molding machine, an injection motor configured to move a screw forward and backward in a cylinder provided in the injection molding machine, a mold thickness adjustment motor configured to adjust a distance between a stationary plate and a toggle lever provided in the injection molding machine, or an injection molding machine motion motor configured to move the injection molding machine from a frame. [6] Injection molding machine according to claim 4, wherein a relay is provided between the control unit and the brake, and A relay is provided between the control unit and the motor.

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