JP2006224561A - Molding method of molding machine and molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a load applied to a driving part for mold clamping and to reduce the cost of a molding machine. <P>SOLUTION: A molding method is applied to the molding machine having a fixed platen 91 fitted with a fixed mold, a base plate arranged to face the fixed platen 91, a movable platen 94 which is arranged forward/backward movably between the fixed platen 91 and the base plate and fitted with a movable mold, a toggle mechanism 95 which is contracted/expanded between the base plate and the movable platen 94 and moves the movable platen 94 forward/backward, and the driving part for mold clamping which contracts/expands the toggle mechanism 95. The movable platen 94 is brought back, and the home position of the toggle mechanism 95 is brought back with the retreat of the movable platen 94. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding method for a molding machine and a molding machine.

  Conventionally, in a molding machine, for example, an injection molding machine, a resin heated and melted in a heating cylinder is injected at a high pressure to fill a cavity space of a mold apparatus, and cooled and solidified in the cavity space. Then, the molded product is taken out.

The injection molding machine includes a mold device, a mold clamping device, and an injection device. The mold device includes a mold including a fixed mold and a movable mold. The mold clamping device includes a fixed platen, a movable platen, and a mold. A mold clamping motor, a toggle mechanism and the like are provided as a clamping driving unit. When the mold clamping motor is driven and the ball screw is actuated to move the crosshead forward and backward, the toggle mechanism is actuated to generate thrust and advance and retract the movable platen to close the mold, clamp and open the mold. I do. On the other hand, the injection device includes the heating cylinder that heats and melts the resin supplied from the hopper, and the injection nozzle for injecting the molten resin, and a screw is freely rotatable in the heating cylinder. And it is arrange | positioned so that advance / retreat is possible. Then, by driving the metering motor and rotating the screw, the resin is accumulated in front of the screw, and by driving the injection motor and moving the screw forward, the resin is injected from the injection nozzle (for example, (See Patent Document 1).
Japanese Patent Laid-Open No. 7-88918

  However, in the conventional injection molding machine, when performing mold opening, it is necessary to transmit the thrust generated by operating the toggle mechanism to the movable platen as the mold opening force. For example, a medical syringe When a molded product having a deep bottom such as the above is molded, since the resistance between the fixed mold and the movable mold and the molded product is large, the load applied to the mold clamping motor becomes excessively large.

  Therefore, in order to increase the mold opening force, it is necessary to increase the capacity of the mold clamping motor or to add another driving unit, which increases the cost of the injection molding machine.

  The present invention solves the problems of the conventional molding machine, can reduce the load applied to the clamping drive unit, and can reduce the cost of the molding machine and molding method and molding The purpose is to provide a machine.

  For this purpose, in the molding method of the molding machine of the present invention, a stationary platen to which a stationary mold is attached, a base plate disposed to face the stationary platen, and disposed between the stationary platen and the base plate so as to be movable forward and backward. A movable platen provided with a movable mold, a toggle mechanism which is bent and stretched between the base plate and the movable platen, and a movable platen is moved forward and backward, and a mold clamping drive unit which bends and stretches the toggle mechanism. Applied to the machine.

  Then, the movable platen is retracted, and the origin position of the toggle mechanism is retracted as the movable platen is retracted.

  According to the present invention, in a molding method of a molding machine, a stationary platen to which a stationary mold is attached, a base plate disposed so as to face the stationary platen, and disposed between the stationary platen and the base plate so as to freely advance and retract. A movable platen provided with a movable mold, a toggle mechanism which is bent and stretched between the base plate and the movable platen, and a movable platen is moved forward and backward, and a mold clamping drive unit which bends and stretches the toggle mechanism. Applied to the machine.

  Then, the movable platen is retracted, and the origin position of the toggle mechanism is retracted as the movable platen is retracted.

  In this case, since the origin position of the toggle mechanism is retracted as the movable platen is retracted, the mold opening force can be increased. Moreover, since it is not necessary to increase the capacity of the driving unit for clamping or add another driving unit in order to increase the mold opening force, the cost of the molding machine can be reduced.

  And the load added to the drive part for mold clamping can be made small by retreating the origin position of a toggle mechanism.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this case, an injection molding machine as a molding machine will be described.

  FIG. 2 is a schematic view of an injection molding machine according to the first embodiment of the present invention.

  In the figure, 51 is an injection apparatus, 52 is a mold apparatus comprising a fixed mold 11 as a first mold and a movable mold 12 as a second mold, and 53 is disposed to face the injection apparatus 51. The mold clamping device 54 is a plasticizing and moving device 54 that supports the injection device 51 so as to be able to move forward and backward, 55 is an ejector device, 60 is a mold thickness adjusting device that functions as a toggle adjusting device, fr1 is the injection device 51, It is a molding machine frame that supports the device 53, the plasticizing moving device 54, and the like.

  The injection device 51 is attached to a heating cylinder 56 as a cylinder member, a screw 57 as an injection member disposed in the heating cylinder 56 so as to be rotatable and movable back and forth, and a front end of the heating cylinder 56. The injection nozzle 58, a hopper 59 disposed in the vicinity of the rear end of the heating cylinder 56, a screw shaft 61 formed to protrude from the rear end of the screw 57, and a load cell 70 as a load detection unit are connected. A movable support portion that includes a front support portion 71 serving as a first support portion and a rear support portion 72 serving as a second support portion and that is disposed so as to be movable forward and backward and rotatably supports the screw shaft 61. As a pressure plate 62, attached to the front support 71, and a pulley-belt type rotation transmission system (a drive pump as a drive element). A driven pulley as a driven element, and a timing belt as a transmission member stretched between the drive pulley and the driven pulley.) As a measuring drive unit connected to the screw shaft 61 via 65 A metering motor 66, attached to the molding machine frame fr1, is a pulley / belt type rotation transmission system (a driving pulley as a driving element, a driven pulley as a driven element, and a tension between a driving pulley and a driven pulley) And a timing belt as a transmission member.) An injection motor 69 as an injection drive unit connected to a ball screw 75 as a movement direction conversion unit via 68 is provided.

  The ball screw 75 functions as a motion direction conversion unit that converts rotational motion into linear motion, and is attached to the ball screw shaft 73 as the first conversion element connected to the rotation transmission system 68 and the rear support portion 72. And a ball nut 74 as a second conversion element screwed with the ball screw shaft 73.

  Further, the plasticizing movement device 54 is attached to the injection device frame fr2, the injection device frame fr2, the plasticizing movement motor 77 as a plasticizing movement drive unit, and the longitudinal direction of the injection device frame fr2. The guide 78 that guides the front support portion 71 and the rear support portion 72 and the injection device frame fr2 are rotatably disposed, and are rotated by driving the plasticizing movement motor 77. A ball screw shaft 81 as a first conversion element, a ball nut 82 as a second conversion element screwed to the ball screw shaft 81, a bracket 83 attached to the rear end of the heating cylinder 56, and the ball nut And a spring 84 or the like as an urging member disposed between 82 and the bracket 83.

  Therefore, by driving the plasticizing movement motor 77, the injection device 51 can be advanced at a predetermined timing to bring the injection nozzle 58 into contact with the fixed mold 11 to perform nozzle touch. The ball screw shaft 81 and the ball nut 82 constitute a ball screw 86, and the ball screw 86 functions as a motion direction conversion unit that converts rotational motion into linear motion.

  The mold clamping device 53 includes a fixed platen 91 as a fixing member attached to the molding machine frame fr1, a toggle support 92 as a base plate, a tie bar 93 installed between the fixed platen 91 and the toggle support 92, A movable platen 94 as a movable member disposed between the fixed platen 91 and the toggle support 92 so as to be movable back and forth along the tie bar 93, and a toggle disposed between the movable platen 94 and the toggle support 92. A mechanism 95, a mold clamping motor 96 as a mold clamping drive unit, and a pulley / belt type rotation transmission system (drive) that transmits the rotation generated by driving the mold clamping motor 96 to the toggle mechanism 95 Drive pulley as element, driven pulley as driven element, and tension between drive pulley and driven pulley 97, a ball screw 98 as a movement direction changing portion connected to the rotation transmission system 97, a crosshead 99 as a moving member connected to the ball screw 98, and the like. Prepare. The fixed mold 11 and the movable mold 12 are attached to the fixed platen 91 and the movable platen 94 so as to face each other.

  The ball screw 98 functions as a motion direction conversion unit that converts rotational motion into linear motion, and is attached to a ball screw shaft 101 as a first conversion element connected to the rotation transmission system 97, and a crosshead 99, A ball nut 102 is provided as a second conversion element screwed into the ball screw shaft 101.

  The toggle mechanism 95 is configured to swing with respect to a toggle lever 105 that is swingably supported with respect to the cross head 99, a toggle lever 106 that is swingably supported with respect to the toggle support 92, and a movable platen 94. A toggle arm 107 that is movably supported is provided, and the toggle levers 105 and 106 and between the toggle lever 106 and the toggle arm 107 are linked.

  The toggle mechanism 95 advances and retracts the movable platen 94 along the tie bar 93 by advancing and retracting the cross head 99 between the toggle support 92 and the movable platen 94 by a mold clamping motor 96, and the movable mold 12 is fixed. The mold device 52 is closed, closed, and opened by being brought into and out of contact with the mold 11. Therefore, when the mold clamping motor 96 is driven, a predetermined thrust is generated in the cross head 99, and the cross head 99 is moved forward and backward by the thrust. The toggle mechanism 95 is bent and stretched as the cross head 99 is moved forward and backward, amplifies the thrust of the cross head 99 at a predetermined toggle magnification, and the amplified thrust is movable as a mold clamping force or a mold opening force. Is transmitted to the platen 94.

  Further, the ejector device 55 is disposed on the rear end surface of the movable platen 94, and a cross head 111 as a moving member disposed so as to be movable back and forth with respect to the movable platen 94, and a projecting motor as a projecting drive unit. 112, a ball screw shaft 113 as a first conversion element that is rotatably arranged with respect to the cross head 111, a second screw attached to the cross head 111 and screwed to the ball screw shaft 113; A pulley-belt type rotation transmission system (a driving pulley as a driving element, a driven element as a driven element) that transmits the rotation generated by driving the ball nut 114 as a conversion element and the protruding motor 112 to the ball screw shaft 113 Driven pulley, and a timing belt as a transmission member stretched between the driving pulley and the driven pulley That.) 116, and an ejector rod and ejector pins (not shown) or the like is caused to advance and retreat along with the advance and retreat of the crosshead 111.

  Therefore, by driving the protruding motor 112, the molded product remaining in the movable mold 12 when the mold is opened can be ejected. A ball screw 115 is constituted by the ball screw shaft 113 and the ball nut 114, and the ball screw 115 functions as a motion direction conversion unit that converts a rotational motion into a straight motion.

  The mold thickness adjusting device 60 includes an adjusting nut 121 and a toggle support 92 that are screwed into a threaded portion formed at the rear end of each tie bar 93 as a toggle adjusting member and as a mold thickness adjusting member. The mold thickness adjusting motor 122 serving as a position adjusting and mold thickness adjusting drive unit, which is disposed to adjust the position of the mold, is generated by driving the mold thickness adjusting motor 122. Timing belt 123 as a transmission member for transmitting the rotation to each adjustment nut 121 and the like, and is operated in conjunction with the toggle mechanism 95 to adjust the origin position of the toggle mechanism 95. Accordingly, for example, when the mold apparatus 52 is replaced, the mold thickness adjustment can be performed by driving the mold thickness adjusting motor 122 so that the toggle support 92 is moved forward and backward with respect to the fixed platen 91.

  In the injection device 51 configured as described above, when the plasticizing movement motor 77 is driven, the rotation of the plasticizing movement motor 77 is transmitted to the ball screw shaft 81 and the ball nut 82 is moved forward and backward. Then, the thrust of the ball nut 82 is transmitted to the bracket 83 via the spring 84, and the injection device 51 is advanced and retracted.

  In the metering step, when the metering motor 66 is driven, the rotation is transmitted to the screw shaft 61 via the rotation transmission system 65, and the screw 57 is rotated, the resin as the molding material supplied from the hopper 59 is It is heated and melted in the heating cylinder 56, moves forward, and is stored in front of the screw 57. Along with this, the screw 57 is retracted to a predetermined position.

  In the injection process, the plasticizing movement motor 77 is driven to press the injection nozzle 58 against the fixed mold 11, and the injection motor 69 is driven to rotate the ball screw shaft 73 via the rotation transmission system 68. . At this time, the pressure plate 62 moves with the rotation of the ball screw shaft 73 and advances the screw 57, so that the resin accumulated in front of the screw 57 is injected from the injection nozzle 58, and the fixed mold 11 and the movable mold 11 are moved. The cavity space formed between the mold 12 is filled. The reaction force at that time is received by the load cell 70 and detected as a shooting output.

  When the mold clamping motor 96 is driven in the mold clamping device 53 and the ejector device 55 configured as described above, the rotation of the mold clamping motor 96 is transmitted to the ball screw shaft 101 via the rotation transmission system 97, The nut 102 is advanced and retracted, and the crosshead 99 is also advanced and retracted. In the mold closing process, the toggle mechanism 95 is extended with the advance of the crosshead 99, the movable platen 94 is advanced to close the mold, and the movable mold 12 is brought into contact with the fixed mold 11. Touched. Subsequently, when a mold clamping process is performed and the mold clamping motor 96 is further driven, a mold clamping force is generated in the toggle mechanism 95, and the movable mold 12 is pressed against the fixed mold 11 by the mold clamping force. A cavity space is formed between the fixed mold 11 and the movable mold 12. In the mold opening process, when the toggle mechanism 95 is bent along with the retraction of the cross head 99, a mold opening force is generated in the toggle mechanism 95, and the movable platen 94 is moved backward by the mold opening force. The mold is opened.

  When the protrusion motor 112 is driven, the rotation of the protrusion motor 112 is transmitted to the ball screw shaft 113 via the rotation transmission system 116, the cross head 111 is advanced and retracted, and the ejector pin is advanced and retracted. As the mold is opened, when the cross motor 111 is advanced by driving the protruding motor 112, the ejector pin is advanced, and the molded product is ejected.

  When the mold thickness adjusting motor 122 is driven in the mold thickness adjusting device 60 having the above-described configuration, the rotation of the mold thickness adjusting motor 122 is transmitted to each adjusting nut 121 via the timing belt 123, and each adjusting nut 121 is rotated. 121 is advanced and retracted with respect to the stationary platen 91 as it is rotated, and the toggle support 92 is advanced and retracted. As a result, the mold thickness is adjusted.

  By the way, in this embodiment, when performing mold opening, the mold opening force generated by operating the toggle mechanism 95 is transmitted to the movable platen 94, but mold opening has started. Thereafter, when the toggle magnification decreases as the toggle mechanism 95 bends, the load applied to the mold clamping motor 96 increases accordingly. For example, when a molded product having a deep bottom such as a medical syringe is molded, since the resistance between the fixed mold 11 and the movable mold 12 and the molded product is large, the load applied to the mold clamping motor 96 Becomes extremely large.

  Therefore, if the capacity of the mold clamping motor 96 is increased or another drive unit is added in order to increase the mold opening force, the cost of the injection molding machine increases.

  Therefore, in the present embodiment, the load applied to the mold clamping motor 96 is reduced by retracting the origin position of the toggle mechanism 95.

  FIG. 1 is a block diagram showing a control circuit of an injection molding machine according to the first embodiment of the present invention, and FIG. 3 is a first diagram showing the operation of the injection molding machine according to the first embodiment of the present invention. 4 is a second view showing the operation of the injection molding machine according to the first embodiment of the present invention, and FIG. 5 is a third view showing the operation of the injection molding machine according to the first embodiment of the present invention. 6 is a fourth diagram showing the operation of the injection molding machine according to the first embodiment of the present invention, and FIG. 7 is a characteristic diagram of the toggle mechanism according to the first embodiment of the present invention. In FIG. 7, the horizontal axis represents the mold opening stroke, and the vertical axis represents the mold opening force.

  In the figure, 11 is a fixed mold, 12 is a movable mold, 91 is a fixed platen, 92 is a toggle support, 94 is a movable platen, 95 is a toggle mechanism, 96 is a clamping motor, 99 is a crosshead, and 101 is a ball. The screw shaft 122 is a mold thickness motor, and the toggle mechanism 95 includes toggle levers 105 and 106 and a toggle arm 107.

  Reference numeral 151 denotes a control unit, 152 denotes an encoder as a position detection unit that detects the position of the crosshead 99, that is, the state of the toggle mechanism 95, by detecting the rotation angle of the mold clamping motor 96, and 153 denotes a mold thickness. By detecting the rotation angle of the adjustment motor 122, an encoder as a position detection unit for detecting the position of the toggle support 92, 155 is a position sensor as a position detection unit for detecting the position of the movable platen 94, and 156 is mold clamping This is a current sensor as a current detector that detects a current supplied to the motor 96. By detecting the rotation angle by the encoder 153, not only can the position of the toggle support 92 be detected, but a linear encoder can be attached to the toggle support 92 and the position of the toggle support 92 can be directly detected.

  In this case, the mold opening is performed a plurality of times, and in the present embodiment, the mold opening is performed twice. In the meantime, the load applied to the mold clamping motor 96 is reduced by retracting the origin position of the toggle mechanism 95 represented by the connecting point between the toggle support 92 and the toggle lever 106 at least once. .

  Therefore, as shown in FIG. 3, the toggle support 92 is placed at the reference position and the movable platen 94 is placed at the mold clamping end position after the mold clamping process is completed. The mold clamping end position represents the mold opening start position where the mold opening is started. In the mold clamping end position, the mold clamping motor 96 is placed in a state of being driven in the forward direction in order to press the movable mold 12 against the fixed mold 11 with a predetermined mold clamping force. In this case, for the toggle support 92, the reference position is represented by the position of the rear end surface Sb, and for the movable platen 94, the mold clamping end position and the mold opening start position are represented by the position of the front end surface Sm.

  Next, a decompression processing unit (not shown) of the control unit 151 performs a decompression process, stops the driving of the mold clamping motor 96, and places the mold apparatus 52 in a decompressed state. Along with this, the mold clamping force becomes zero (0).

  Subsequently, the mold opening processing means (not shown) of the control unit 151 drives the mold clamping motor 96 in the reverse direction, bends the toggle mechanism 95, retracts the movable platen 94 from the mold opening start position, and opens the mold. To start. During this time, a position holding processing unit (not shown) of the control unit 151 performs position holding processing, drives the mold thickness adjusting motor 122 to perform position control so that the toggle support 92 does not move, and sets the toggle support 92 to the reference position. Hold on. When the mold thickness adjusting motor 122 is a motor with a brake, the position holding processing unit stops driving the mold thickness adjusting motor 122. Along with this, the brake of the mold thickness adjusting motor 122 is engaged, and the toggle support 92 is held at the reference position.

  By the way, as indicated by the line L1 in FIG. 7, in the toggle mechanism 95, the mold opening force increases corresponding to the amount of extension, the movable platen 94 is placed at the mold opening start position, and the mold opening stroke becomes zero. Then, the mold opening force becomes the maximum value f1, but the mold opening force becomes smaller as the mold opening stroke becomes longer as it is bent. The mold opening stroke is zero at the mold opening start position of the movable platen 94 and increases as the distance from the mold opening start position increases.

  When the toggle mechanism 95 is bent and, for example, the mold opening stroke becomes 3 [mm] or more, the mold opening force suddenly decreases and reaches the value f2, the load applied to the mold clamping motor 96 is excessively large. turn into.

  Therefore, a position where the mold opening stroke is 3 [mm] or more away from the mold opening start position is set as the origin adjustment position. A position adjustment condition establishment determination processing unit (not shown) of the control unit 151 performs position adjustment condition establishment determination processing, and the movable platen 94 determines whether or not the position adjustment condition for adjusting the origin position of the toggle mechanism 95 is established. Judgment is made based on whether or not the origin adjustment position has been reached. For this purpose, the position adjustment condition satisfaction determination processing means reads the rotation angle detected by the encoder 152, calculates the position of the movable platen 94 based on the rotation angle, and whether the movable platen 94 has reached the origin adjustment position. Judge whether.

  Here, in order to detect a mold opening force when the movable platen 94 moves backward and mold opening is performed, a mold clamping force sensor (not shown) may be provided. In particular, when molding a molded product having a deep bottom, the mold clamping force sensor detects a state in which the mold opening force for compressing the tie bar 93 is continued when the mold is opened. Therefore, if the mold opening force does not become less than the preset value within the preset time limit even though the movable platen 94 is retracted, the position of the movable platen 94 when the limit time is reached. Is the origin adjustment position.

  Further, if the mold opening force does not become a predetermined value or less before the movable platen 94 reaches a preset position, the preset position of the movable platen 94 is set as the origin adjustment position. Thus, the origin adjustment position can be determined based on the mold opening force.

  If the torque of the mold clamping motor 96 does not fall below the preset value within the preset time limit even though the movable platen 94 has moved backward, the movable platen 94 can be moved when the limit time is reached. The position of the platen 94 is set as the origin adjustment position.

  Further, when the torque of the mold clamping motor 96 does not become a preset value or less by the time the movable platen 94 reaches the preset position, the preset position of the movable platen 94 becomes the origin adjustment position. Is done. Thus, the origin adjustment position can be determined based on the torque of the mold clamping motor 96.

  Then, as shown in FIG. 4, when the movable platen 94 reaches the origin adjustment position and the position adjustment condition is satisfied, the mold opening / stopping processing unit (not shown) of the control unit 151 performs the mold opening / stopping process, and the mold clamping is performed. The driving of the motor 96 is stopped, and the movable platen 94 is stopped at the origin adjustment position.

  Subsequently, with the movable platen 94 held at the origin adjustment position as shown in FIG. 5, the origin position of the toggle mechanism 95 is moved backward without changing the distance between the fixed platen 91 and the movable platen 94. Adjust. Therefore, an origin position adjustment processing unit (not shown) of the control unit 151 performs an origin position adjustment process, drives the mold thickness adjustment motor 122 in the forward direction, and in the present embodiment, the distance is The toggle support 92 is moved backward by δ. At this time, the origin position adjustment processing unit reads the rotation angle detected by the encoder 153, calculates the position of the toggle support 92 based on the rotation angle, and the toggle support 92 is set behind the reference position by a distance δ. It is determined whether or not the set backward position has been reached. When the toggle support 92 reaches the retracted position, the origin position adjustment processing unit stops driving the mold thickness adjusting motor 122.

  Further, while the driving of the mold thickness adjusting motor 122 is started and the toggle support 92 is moved backward, the toggle plate 92 is not moved backward, that is, the toggle plate 92 is held at the origin adjustment position. The mechanism 95 is extended as much as the toggle support 92 is retracted. For this purpose, the origin position adjustment processing means drives the mold clamping motor 96 in the forward direction, extends the toggle mechanism 95, and holds the movable platen 94 at the origin adjustment position. The amount of driving the mold clamping motor 96 to hold the movable platen 94 at the origin adjustment position is set in advance.

  In this way, by placing the toggle support 92 in the retracted position while extending the toggle mechanism 95, the origin position of the toggle mechanism 95 can be retracted to a position corresponding to the required mold opening force. The relationship between the opening stroke and the mold opening force is as indicated by a line L2 in FIG. 7, and the mold opening force at the origin adjustment position is increased as indicated by an arrow, and reaches a maximum value f1.

  Subsequently, the mold opening processing means drives the mold clamping motor 96 in the reverse direction, bends the toggle mechanism 95 as shown in FIG. 6, and retracts the movable platen 94 again from the origin adjustment position, thereby Continue opening. During this time, the position holding processing means performs position holding processing, drives the mold thickness adjusting motor 122 to perform position control, and holds the toggle support 92 in the retracted position.

  In this way, when the movable platen 94 is retracted and reaches the retreat limit position, the mold opening processing means ends the mold opening. For this purpose, the mold opening processing means reads the rotation angle detected by the encoder 152, calculates the position of the movable platen 94 based on the rotation angle, and determines whether or not the movable platen 94 has reached the retreat limit position. To do.

  Subsequently, an initialization processing unit (not shown) of the control unit 151 performs initialization processing, drives the mold thickness adjusting motor 122 in the reverse direction, and only a predetermined distance, in the present embodiment, the distance δ. The toggle support 92 is advanced. For this purpose, the initialization processing unit reads the rotation angle detected by the encoder 153, calculates the position of the toggle support 92 based on the rotation angle, and determines whether the toggle support 92 has reached the reference position. . Then, when the toggle support 92 reaches the reference position, the initialization processing means stops driving the mold thickness adjusting motor 122.

  In addition, the initialization processing means drives the mold clamping motor 96 in the reverse direction while the toggle support 92 is being advanced to bend the toggle mechanism 95 so that the movable platen 94 is represented by the retreat limit position. Is held at the mold closing start position.

  Thus, when the movable platen 94 reaches the origin adjustment position, the origin position of the toggle mechanism 95 is adjusted and retracted, so that the mold opening force can be increased. Further, since it is not necessary to increase the capacity of the mold clamping motor 96 or add another drive unit in order to increase the mold opening force, the cost of the injection molding machine can be reduced.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol, and the effect of the same embodiment is used about the effect of the invention by having the same structure. .

  FIG. 8 is a first diagram showing the operation of the injection molding machine in the second embodiment of the present invention, FIG. 9 is a second diagram showing the operation of the injection molding machine in the second embodiment of the present invention, FIG. 10 is a third diagram showing the operation of the injection molding machine in the second embodiment of the present invention, FIG. 11 is a fourth diagram showing the operation of the injection molding machine in the second embodiment of the present invention, FIG. 12 is a fifth diagram showing the operation of the injection molding machine according to the second embodiment of the present invention.

  In this case, as shown in FIG. 8, with the mold clamping process completed, the toggle support 92 as the base plate is placed at the reference position, and the movable platen 94 as the movable member is placed at the mold clamping end position. As described above, the mold clamping end position represents the mold opening start position, and at the mold clamping end position, the mold clamping motor 96 (FIG. 1) as a mold clamping drive unit has a predetermined mold clamping force. In order to press the movable mold 12 as the second mold against the fixed mold 11 as the first mold, the movable mold 12 is placed in a state driven in the forward direction.

  Next, the depressurization processing means of the control unit 151 stops the driving of the mold clamping motor 96, puts the mold apparatus 52 in a depressurized state, and makes the mold clamping force zero.

  Subsequently, the mold opening processing means of the control unit 151 drives the mold clamping motor 96 in the reverse direction, bends the toggle mechanism 95, retracts the movable platen 94 from the mold opening start position, and opens the mold. Start. During this time, the position holding processing means of the control unit 151 controls the position by driving the mold thickness adjusting motor 122 as the position adjusting and mold thickness adjusting drive unit so that the toggle support 92 does not move. And the toggle support 92 is held at the reference position.

  Then, the position adjustment condition establishment determination processing means of the control unit 151 determines whether or not the position adjustment condition is established depending on whether or not the movable platen 94 has reached the origin adjustment position. As shown in FIG. 9, when the movable platen 94 reaches the origin adjustment position and the position adjustment condition is satisfied, the mold opening stop processing unit of the control unit 151 stops the driving of the mold clamping motor 96 to move the mold. The platen 94 is stopped at the origin adjustment position, and the origin adjustment position is recorded in a recording device (not shown).

  Subsequently, as shown in FIG. 10, the origin position adjustment processing means extends the toggle mechanism 95 with the toggle support 92 held at the reference position, and moves the movable platen 94 forward from the origin adjustment position. Put it back in the opening position.

  Next, as shown in FIG. 11, with the toggle mechanism 95 extended, the toggle support 92 is placed in the retracted position, and the movable platen 94 is placed again in the origin adjustment position, so that the origin position of the toggle mechanism 95 is retracted. To adjust. For this purpose, the origin position adjustment processing unit of the control unit 151 drives the mold thickness adjusting motor 122 in the forward direction to move the toggle support 92 backward by the distance δ. At this time, the origin position adjustment processing unit reads the rotation angle detected by the encoder 153 as the position detection unit, calculates the position of the toggle support 92 based on the rotation angle, and the toggle support 92 is a distance from the reference position. It is determined whether or not the backward position set backward by δ has been reached. Then, when the toggle support 92 reaches the retracted position, the origin position adjustment processing unit stops driving the mold thickness adjusting motor 122. In this way, the origin position of the toggle mechanism 95 can be retracted. As a result, the mold opening force at the origin adjustment position becomes the maximum value f1.

  Subsequently, the mold opening processing means drives the mold clamping motor 96 in the reverse direction, bends the toggle mechanism 95 as shown in FIG. 12, and moves the movable platen 94 backward again from the origin adjustment position. Continue opening. During this time, the position holding processing means performs position holding processing, drives the mold thickness adjusting motor 122 to perform position control, and holds the toggle support 92 in the retracted position.

  In this way, when the movable platen 94 is retracted and reaches the retreat limit position, the mold opening processing means ends the mold opening. For this purpose, the mold opening processing means reads the rotation angle detected by the encoder 152 as the position detection unit, calculates the position of the movable platen 94 based on the rotation angle, and the movable platen 94 reaches the retreat limit position. Determine if you did.

  Subsequently, the initialization processing means of the control unit 151 drives the mold thickness adjusting motor 122 in the reverse direction to advance the toggle support 92 by a predetermined distance, in the present embodiment, by the distance δ. Therefore, the initialization processing means reads the rotation angle detected by the encoder 153, calculates the position of the toggle support 92 based on the rotation angle, and the toggle support 92 has reached the reference position which is the original position. Determine whether or not. Then, when the toggle support 92 reaches the reference position, the initialization processing means stops driving the mold thickness adjusting motor 122.

  Further, the initialization processing means drives the clamping motor 96 in the reverse direction while the toggle support 92 is being advanced to bend the toggle mechanism 95 so that the toggle support 92 is represented by the retreat limit position. Is held at the mold closing start position.

  Thus, when the movable platen 94 reaches the origin adjustment position, the origin position of the toggle mechanism 95 is adjusted and retracted, so that the mold opening force can be increased. Further, since it is not necessary to increase the capacity of the mold clamping motor 96 or add another drive unit in order to increase the mold opening force, the cost of the injection molding machine can be reduced.

  In each of the embodiments described above, the position of the movable platen 94 is calculated based on the rotation angle detected by the encoder 152. However, the position sensor 155 can directly detect the position of the movable platen 94. it can.

  In each of the above embodiments, the position adjustment condition establishment determination processing unit determines whether or not the position adjustment condition is established based on whether or not the movable platen 94 has reached the origin adjustment position. It can also be determined based on the torque generated in the mold clamping motor 96. In that case, the torque of the mold clamping motor 96 assumed when the movable platen 94 reaches the origin adjustment position is calculated in advance, and the torque is set as a set value. When the torque generated in the mold clamping motor 96 reaches a set value, it is determined that the position adjustment condition is satisfied.

  In each of the above embodiments, when the distance δ from the mold opening start position to the origin adjustment position is set, the distance for moving the movable platen 94 and the distance for moving the toggle support 92 are both set to δ. However, the distance for retracting the movable platen 94 and the distance for retracting the toggle support 92 can be set differently.

  In each of the above embodiments, the initialization process is performed before the mold closing of the next cycle is started. However, the initialization process is performed before the mold closing of the next cycle is completed. It can be performed. Furthermore, the initialization process can be performed after the mold opening is completed.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

It is a block diagram which shows the control circuit of the injection molding machine in the 1st Embodiment of this invention. It is the schematic of the injection molding machine in the 1st Embodiment of this invention. It is a 1st figure which shows operation | movement of the injection molding machine in the 1st Embodiment of this invention. It is a 2nd figure which shows operation | movement of the injection molding machine in the 1st Embodiment of this invention. It is a 3rd figure which shows operation | movement of the injection molding machine in the 1st Embodiment of this invention. It is a 4th figure which shows operation | movement of the injection molding machine in the 1st Embodiment of this invention. It is a characteristic view of the toggle mechanism in the 1st Embodiment of this invention. It is a 1st figure which shows operation | movement of the injection molding machine in the 2nd Embodiment of this invention. It is a 2nd figure which shows operation | movement of the injection molding machine in the 2nd Embodiment of this invention. It is a 3rd figure which shows operation | movement of the injection molding machine in the 2nd Embodiment of this invention. It is a 4th figure which shows operation | movement of the injection molding machine in the 2nd Embodiment of this invention. It is a 5th figure which shows operation | movement of the injection molding machine in the 2nd Embodiment of this invention.

Explanation of symbols

11 fixed mold 12 movable mold 91 fixed platen 92 toggle support 94 movable platen 95 toggle mechanism 96 mold clamping motor 122 mold thickness adjusting motor 151 controller

Claims (10)

A fixed platen to which a fixed mold is attached, a base plate disposed to face the fixed platen, a movable platen to which a movable mold is attached, which is disposed between the fixed platen and the base plate so as to be movable back and forth, In a molding method of a molding machine having a toggle mechanism that is bent and stretched between a base plate and a movable platen, and that moves the movable platen back and forth, and a drive unit for clamping to bend and stretch the toggle mechanism,
(A) retracting the movable platen;
(B) A molding method for a molding machine, wherein the origin position of the toggle mechanism is retracted as the movable platen is retracted. (A) The movable platen is retracted in a plurality of times,
(B) The molding method of the molding machine according to claim 1, wherein the origin position of the toggle mechanism is retracted at least once while the movable platen is retracted a plurality of times.   The molding method for a molding machine according to claim 1 or 2, wherein the mold thickness adjusting mechanism and the toggle mechanism are interlocked.   The molding method of the molding machine according to claim 1, wherein the origin position of the toggle mechanism is retracted without changing a distance between the fixed platen and the movable platen.   The molding method of the molding machine according to claim 1, wherein the origin position of the toggle mechanism is retracted to a position corresponding to a preset mold opening force.   The determination as to whether or not it is necessary to move the origin position of the toggle mechanism is performed based on a detected value of the position of the movable platen, a torque of a driving unit for clamping, or a detected value of a clamping force sensor. 6. The molding method for a molding machine according to any one of 5 above.   The origin position of the toggle mechanism is returned to the original position before the mold closing of the next cycle is started or before the mold closing is completed, The molding machine according to any one of claims 1 to 6 Molding method.   The molding method of the molding machine according to claim 1, wherein the origin position of the toggle mechanism is returned to the original position after the mold opening is completed. (A) a stationary platen to which a stationary mold is attached;
(B) a base plate disposed to face the fixed platen;
(C) a movable platen that is disposed between the fixed platen and the base plate so as to be movable back and forth, and to which a movable mold is attached;
(D) a toggle mechanism that is bent and stretched between the base plate and the movable platen, and advances and retracts the movable platen;
(E) a clamping unit that bends and stretches the toggle mechanism;
(F) mold opening processing means for retracting the movable platen;
(G) A molding machine comprising origin position adjustment processing means for retracting the origin position of the toggle mechanism as the movable platen is retracted. (A) having a position adjusting drive for adjusting the position of the base plate;
11. The molding machine according to claim 10, wherein the origin position adjustment processing unit drives the position adjustment drive unit to retract the base plate to retract the origin position of the toggle mechanism.

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