Control device of injection molding machine and control method of injection molding machine

Abstract

A control device (24) for an injection molding machine (10) comprises: a pressure acquisition unit (60) for acquiring a resin pressure (Pr); an injection control unit (64) for injecting a resin (R) into a metal mold (12); an ejection control unit (66) for causing an ejector pin (44) to protrude before the resin pressure (Pr) reaches a predetermined target pressure (Pr1); and an insertion control unit (68) for inserting a support member (50) into a gap (g) before the resin pressure (Pr) reaches a predetermined target pressure (Pr1), thereby causing an ejector plate (46) to be supported by the support member (50) and a mounting plate (38).

Description

Technical Field

[0001] The present invention relates to a control device and a control method for an injection molding machine. Background Art

[0002] An injection molding machine is a machine that produces molded products by solidifying molten resin after filling it into a metal mold. In the field of such injection molding machines, it is known to have a control that maintains the resin pressure at a predetermined target pressure (pressure holding) or above from the time the metal mold is filled with resin until the resin at the gate (entrance to the metal mold) is solidified (for example, the pressure holding action of Japanese Patent Gazette No. 2019-171791). The control that solidifies the resin at the gate is also called gate sealing. By performing gate sealing, the resin filled in the metal mold is prevented from flowing back to the injection device side. Summary of the Invention

[0003] Injection molding machines can also produce molded products with recesses or holes by protruding pins into the mold before the resin solidifies. However, the pressure-holding action required to seal the gate sometimes makes it difficult to reliably mold products with recesses or holes.

[0004] That is, when trying to seal the gate with a pin protruding into the mold, the pin may continue to be subjected to a resin pressure exceeding a predetermined level and be squeezed out of the mold before the resin solidifies. In this case, the molded product cannot be properly provided with recesses or holes.

[0005] Therefore, an object of the present invention is to provide a control device and a control method for an injection molding machine that can reliably mold a molded product having a concave shape and a hole.

[0006] The first embodiment is a control device for an injection molding machine, the injection molding machine comprising: a movable platen that moves in the opening and closing direction of a metal mold; a mounting plate that is provided on the metal mold side of the movable platen; a spacer that connects the metal mold and the mounting plate in such a manner that the metal mold opens and closes as the movable platen moves in the opening and closing direction, and forms an ejection movable space between the metal mold and the mounting plate; an ejector plate that is provided in the ejection movable space and moves forward and backward relative to the metal mold; an ejector pin that is provided on the ejector plate and projects toward the metal mold; a supporting member that is inserted and removed from the gap between the mounting plate and the advancing ejector plate; and an injection unit that injects plasticized resin. The control device comprises: a pressure acquiring unit for acquiring the resin pressure in the metal mold; an injection control unit for injecting the resin into the closed metal mold by controlling the injection unit, and causing the resin pressure to reach a predetermined target pressure; an ejection control unit for advancing the ejector plate before the resin pressure reaches the predetermined target pressure, thereby causing the ejector pin to protrude into the metal mold, thereby imparting at least one of a recess and a hole to the shape of the resin in the metal mold; and an insertion control unit for inserting the support member into the gap before the resin pressure reaches the predetermined target pressure, thereby causing the ejector plate, which is subjected to the resin pressure, to be supported by the support member and the mounting plate.

[0007] The second method is a control method of an injection molding machine, the injection molding machine comprising: a movable platen that moves in the opening and closing direction of the metal mold; a mounting plate that is provided on the metal mold side of the movable platen; a spacer that connects the metal mold and the mounting plate in such a manner that the metal mold opens and closes as the movable platen moves in the opening and closing direction, and forms an ejection movable space between the metal mold and the mounting plate; an ejector plate that is provided in the ejection movable space and moves forward and backward relative to the metal mold; an ejector pin that is provided on the ejector plate and protrudes toward the metal mold; a supporting member that is inserted and removed from the gap between the mounting plate and the advancing ejector plate; and an injection unit that injects molding The control method of the injection molding machine comprises: an injection control step of injecting the resin into the closed metal mold by controlling the injection part; an ejection advancement step of advancing the ejector plate after the injection control step is started, so that the ejector pin protrudes into the metal mold, thereby giving at least one of a concave portion and a hole portion to the shape of the resin in the metal mold; an insertion control step of inserting the support member into the gap after the ejection advancement step is started; and a holding pressure control step of causing the support member and the mounting plate to support the ejector plate after the insertion control step is started, and causing the resin pressure in the metal mold to reach a predetermined target pressure.

[0008] According to the present invention, a control device and a control method for an injection molding machine are provided, which are capable of reliably molding a molded product having a concave shape and a hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural diagram of an injection molding machine according to an embodiment.

[0010] Figure 2 It is a top view of the metal mold opening and closing device according to the embodiment.

[0011] Figure 3 yes Figure 2 Side view of the metal mold opening and closing device.

[0012] Figure 4 This is a top view of the mold opening and closing device when the ejector pin protrudes into the mold.

[0013] Figure 5 yes Figure 4 Side view of the metal mold opening and closing device.

[0014] Figure 6 It is a structural diagram of the plugging and unplugging device according to the embodiment.

[0015] Figure 7This is a top view of the mold opening and closing device when the support member is inserted into the gap between the mounting plate and the ejector plate.

[0016] Figure 8 This is a top view of the mold opening and closing device when the ejector plate is supported by the support member, the mounting plate, and the movable platen.

[0017] Figure 9 yes Figure 8 Side view of the metal mold opening and closing device.

[0018] Figure 10 It is a structural diagram of the control device according to the embodiment.

[0019] Figure 11 This is a flowchart illustrating the flow of the control method according to the embodiment.

[0020] Figure 12 This is a timing chart illustrating the changes in the resin pressure in the mold, the position of the ejector plate in the opening and closing directions, and the position of the support member in the insertion and removal directions, which exemplifies the control method.

[0021] Figure 13 This is a structural diagram of the ejection device of Modification 1.

[0022] Figure 14 A diagram for explaining protrusion of a molded product by the ejector device according to Modification 1.

[0023] Figure 15 This is a structural diagram of the control device of Modification Example 1.

[0024] Figure 16 This is a timing chart illustrating the transition of the position of the movable platen in the opening and closing directions, the position of the ejector plate in the opening and closing directions, and the position of the support member in the insertion and removal directions according to Modification 1.

[0025] Figure 17 This is a structural diagram of the control device of Modification 3.

[0026] Figure 18 This is a timing chart illustrating the transition of the position of the movable platen in the opening and closing directions, the position of the ejector plate in the opening and closing directions, the position of the support member in the insertion and removal directions, and the resin pressure in the mold according to Modification 3.

[0027] Figure 19 This is a structural diagram when the support member of Modification 4 is viewed from the opening and closing direction. DETAILED DESCRIPTION

[0028] Hereinafter, preferred embodiments are listed, with reference to the accompanying drawings. Figure 1 The control device for an injection molding machine and the control method for an injection molding machine according to the present invention will be described in detail.

[0029] [Implementation Method]

[0030] Figure 1 It is a structural diagram of the injection molding machine 10 according to the embodiment.

[0031] The injection molding machine 10 is a machine that injects molten (plasticized) resin R into a metal mold 12 ( Figure 1 ) and solidify to produce molded products. Figure 1 As shown, the injection molding machine 10 includes an injection device (injection unit) 14, a mold opening and closing device (mold opening and closing unit) 16, and a machine base 18 supporting them. In addition, the injection molding machine 10 also includes an ejector 20, an insertion and extraction device 22, and a control device 24.

[0032] The machine base 18 supports the injection device 14 and the mold opening and closing device 16 .

[0033] The injection device 14 is a device that melts the resin R and injects it into the metal mold 12. The injection device 14 includes a generally cylindrical cylinder 26 (heating cylinder), a screw 28 disposed in the cylinder 26, and a nozzle 30. The nozzle 30 is provided at the front end of the cylinder 26 on the metal mold 12 side.

[0034] The cylinder 26 is provided with a supply port 32. The supply port 32 is located at the end of the cylinder 26 opposite the nozzle 30. Resin R, the material for the molded product, is supplied into the cylinder 26 through the supply port 32. At the time of supply to the supply port 32, the resin R is, for example, a granular solid. Although not shown, a heater is also provided in the cylinder 26. The heater heats the resin R within the cylinder 26.

[0035] The screw 28 is connected to a motor 28a that rotates the screw 28. From the viewpoint of control accuracy, the motor 28a is preferably a servo motor. The screw 28 is driven by the motor 28a to rotate about its own central axis A. 28 The resin R in the cylinder 26 is thereby stirred and pressure-fed toward the nozzle 30 . The pressure-fed resin R accumulates in the cylinder 26 on the nozzle 30 side.

[0036] In addition, the screw 28 is also connected to the screw 28 along the central axis A 28 The motor 28b is connected to the cylinder 26 and is movable relative to the cylinder 26. From the perspective of control accuracy, the motor 28b is preferably a servo motor. In order to transmit its rotational force to the screw 28 as a linear force, the motor 28b is connected to the screw 28 via, for example, a ball screw mechanism (not shown). The screw 28 is driven by the motor 28b to move (advance) within the cylinder 26 toward the nozzle 30. As a result, the resin R accumulated on the nozzle 30 side of the cylinder 26 is extruded (injected) out of the cylinder 26 through the nozzle 30.

[0037] The injection device 14 having the above structure can melt the resin R in the cylinder 26 by heating with the heater and stirring with the screw 28. The molten resin R can be injected from the nozzle 30 into the mold 12 by the pressure generated by the advancement of the screw 28.

[0038] In addition, Figure 1 In the embodiment, the metal mold 12 and the nozzle 30 are separated from each other, but the injection of the molten resin R is actually performed with the metal mold 12 and the nozzle 30 connected (nozzle contact). The control of the injection device 14 during the execution of the injection will be described in detail later in the description of the structure of the control device 24 (injection control unit 64).

[0039] The mold 12 includes a fixed mold 12a and a movable mold 12b. The fixed mold 12a faces the injection device 14. The movable mold 12b faces the fixed mold 12a on the side opposite the injection device 14 and is movable in the direction of opposition. The mold 12 opens when the movable mold 12b moves away from the fixed mold 12a and closes when the movable mold 12b contacts the fixed mold 12a.

[0040] In this embodiment, if Figure 1 As shown by the arrow in the middle, the direction in which the movable metal mold 12b approaches the fixed metal mold 12a is called the "closing direction", and the opposite direction is called the "opening direction". In addition, the opening direction and the closing direction are collectively referred to as the "opening and closing direction". The opening and closing direction is related to the gravity direction ( Figure 1 In addition, the central axis A of the screw 28 is perpendicular to the vertical direction. 28 Extending along the opening and closing direction.

[0041] The movement of the movable mold 12b in the opening and closing direction is achieved by the mold opening and closing device 16. The mold opening and closing device 16 comprises a movable platen 34, a toggle mechanism 36, a mounting plate 38, and a spacer 40. The movable platen 34 is a plate-shaped component mounted on the opening side of the movable mold 12b. The toggle mechanism 36 comprises a motor 36a that generates rotational force, a ball screw 36b that converts this rotational force into a linear force in the opening and closing direction, and a plurality of toggle links (including elbows) 36c that transmit this linear force to the movable platen 34.

[0042] The movable platen 34 is moved reciprocally between a predetermined mold closing position and a mold opening position along the opening and closing direction by the linear force in the opening and closing direction transmitted from the toggle mechanism 36 .

[0043] Figure 216 is a top view of the metal mold opening and closing device 16 of the embodiment. Figure 2 In order to simplify the diagram, Figure 1 The inserting and removing device 22 is shown below the metal mold opening and closing device 16.

[0044] Reference Figure 2 Next, the structure of the mold opening and closing device 16 will be described. The mounting plate 38 of the mold opening and closing device 16 is provided between the movable platen 34 and the spacer 40. The mounting plate 38 connects the movable platen 34 and the spacer 40 to each other. The spacer 40 is provided between the movable mold 12b and the mounting plate 38. The spacer 40 connects the movable mold 12b and the mounting plate 38 to each other.

[0045] Thus, in this embodiment, the movable mold 12b and the movable platen 34 are connected via the mounting plate 38 and the spacer 40. Thus, in this embodiment, the mold 12 can be opened and closed (mold opening and closing) along with the movement of the movable platen 34. In this embodiment, the mold 12 is fully closed when the movable platen 34 is in the mold closing position, and the mold 12 is fully opened when it is in the mold opening position.

[0046] In addition, a space called ejection movable space 42 in this embodiment is formed between the movable metal mold 12b and the mounting plate 38 by the spacer 40. The ejection movable space 42 is connected to the insertion and extraction device 22 (see Figure 1 ) side (downward) is open.

[0047] Reference Figure 2 , the ejection device 20 will be further described. The ejection device 20 includes: an ejection pin 44, an ejection plate 46, and a first direct motion mechanism 48. In addition, regarding the structural example of the first direct motion mechanism 48, refer to Figure 3 This will be described later.

[0048] The ejector pin 44 is a pin that projects into the metal mold 12 to impart a concave portion (hole portion) shape to the molded product. Figure 2 As shown, the ejector pins 44 extend in the ejection movable space 42 in the opening and closing direction and penetrate the movable metal mold 12b. Figure 2 In the example shown, 2 is used, but it is not limited to this.

[0049] The ejector plate 46 is a plate that supports the ejector pins 44 from the side opposite to the mold 12. The ejector plate 46 is provided in the ejector movable space 42 of the mold opening and closing device 16 formed by the spacer 40.

[0050] Figure 3 yes Figure 2 A side view of the metal mold opening and closing device 16.

[0051] The first linear motion mechanism 48 linearly moves the ejector plate 46 in the opening and closing direction. The first linear motion mechanism 48 of this embodiment includes a motor 48a, a ball screw 48b, a belt 48c, a nut 48d, and an ejector rod 48e connected to the nut 48d.

[0052] Motor 48a is a driving source that generates rotational force. From the perspective of control accuracy, motor 48a is preferably a servo motor. Ball screw 48b is arranged so that its axial direction is parallel to the opening and closing direction, and the rotational force of motor 48a is transmitted via belt 48c. Nut 48d is threadedly engaged with ball screw 48b. Nut 48d moves along the axial direction (opening and closing direction) of ball screw 48b in response to the rotation of ball screw 48b.

[0053] The ejector rod 48e is a rod connected to the nut 48d and the ejector plate 46. In this embodiment, Figure 3 As shown, the ejector rod 48 e is provided so as to be inserted through the movable platen 34 and the mounting plate 38 .

[0054] In addition, Figure 3 In the example of , three ejector rods 48e are arranged in a vertical direction, but the number and arrangement of the ejector rods 48e are not limited thereto. Figure 3 In the example shown in FIG, one nut 48d is connected to three ejector rods 48e. However, the number of nuts 48d may be three, and each nut may be connected to one ejector rod 48e.

[0055] The first direct-acting mechanism 48 described above can move the ejector plate 46 in the opening and closing directions by driving the motor 48a. The first direct-acting mechanism 48 is controlled by the control device 24, described in detail later, thereby moving the ejector plate 46 between two predetermined positions in the opening and closing directions. Hereinafter, the opening position of these two positions will be referred to as the "retracted position Po0," and the closing position will be referred to as the "advanced position Po1." Furthermore, moving the ejector plate 46 toward the mold 12 (closing direction) is also referred to as "advancing," and moving it in the opposite direction is also referred to as "retracting."

[0056] In this embodiment, Figure 2 as well as Figure 3The position of the ejector plate 46 shown in the example is set as the retracted position Po0. In addition, in the present embodiment, the "position of the ejector plate 46" refers to the position of the center of the ejector plate 46 in the thickness direction (opening and closing direction) of the ejector plate 46. That is, in the present embodiment, when the ejector plate 46 is in the retracted position Po0, it means that the center of the ejector plate 46 in the thickness direction of the ejector plate 46 is in the retracted position Po0. However, the position of the ejector plate 46 is not limited to this. For example, the position of the ejector plate 46 in the opening and closing direction of the surface on the opening direction side may be set as the position of the ejector plate 46. In addition, the position of the ejector plate 46 in the opening and closing direction of the surface on the closing direction side may be set as the position of the ejector plate 46.

[0057] In the present embodiment, when the ejector plate 46 is at the retracted position Po0 , the tip of the ejector pin 44 on the mold 12 side is flush with the inner surface of the movable mold 12 b , but the present invention is not limited thereto.

[0058] Figure 4 It is a plan view of the mold opening and closing device 16 when the ejector pin 44 protrudes into the mold 12 . Figure 5 yes Figure 4 A side view of the metal mold opening and closing device 16. Figure 4 In, with Figure 2 The plug-in device 22 is also omitted.

[0059] In this embodiment, Figure 4 as well as Figure 5 The position of the ejector plate 46 is set as the forward position Po1. As described above, when the ejector plate 46 is at the forward position Po1, it means that the center of the ejector plate 46 in the thickness direction is at the forward position Po1. When the ejector plate 46 advances, as shown in FIG. Figure 4 and Figure 5 As shown, the gap g between the mounting plate 38 and the ejection plate 46 is enlarged.

[0060] When the ejector plate 46 is at the advanced position Po1, the ejector pin 44 projects into the mold 12. This projection forms a recess (hole) in the resin R filled into the mold 12.

[0061] Figure 6 2 is a structural diagram of the plugging and unplugging device 22 according to the embodiment.

[0062] Next, the plug-in device 22 will be described. Figure 1 As shown in FIG. 1 , in this embodiment, the insertion and extraction device 22 is provided below the mold opening and closing device 16 and the mold 12 . The insertion and extraction device 22 includes a support member 50 and a second linear motion mechanism 52 .

[0063] The support member 50 is inserted into and removed from the gap g between the mounting plate 38 and the ejector plate 46. In this embodiment, the upward direction is set as the insertion direction of the support member 50, and the downward direction is set as the removal direction.

[0064] The support member 50 is a U-shaped sliding plate in this embodiment. The support member 50 has a shorter thickness (length in the opening and closing direction) than the width of the gap g in the opening and closing direction when the ejector plate 46 is in the advanced position Po1.

[0065] By forming the support member 50 into a U-shape, interference between the three ejector rods 48e arranged in the vertical direction and the support member 50 can be avoided when the support member 50 is inserted into the gap g (see FIG. Figure 6 ). In addition, of course, when the number and arrangement of the ejector rods 48e are changed, the shape of the support member 50 may be changed to match the change so as to avoid mutual interference between the ejector rods 48e and the support member 50.

[0066] The second direct-acting mechanism 52 is a mechanism that inserts and removes the support member 50 relative to the gap g by moving the support member 50 in the insertion and removal direction. Figure 6 As shown, the second direct-acting mechanism 52 includes a motor 52 a , a ball screw 52 b , a belt 52 c , and a nut 52 d .

[0067] The motor 52a is a driving source that generates rotational force. From the perspective of control accuracy, the motor 52a is preferably a servo motor. The ball screw 52b is arranged axially parallel to the insertion and removal direction of the support member 50. The rotational force of the motor 52a is transmitted via the belt 52c. The nut 52d is threadedly engaged with the ball screw 52b, and the ball screw 52b moves axially (in the insertion and removal direction) according to the rotation of the ball screw 52b.

[0068] The second direct-acting mechanism 52 allows the support member 50 to move in the insertion and removal direction by being coupled to the nut 52d.

[0069] Figure 7 It is a plan view of the mold opening and closing device 16 when the support member 50 is inserted into the gap g between the mounting plate 38 and the ejector plate 46 .

[0070] In this embodiment, the width of the gap g in the opening and closing direction is larger than the thickness of the support member 50. Figure 7As shown, the support member 50 can be inserted into the gap g while a portion (g') of the gap g remains between the support member 50 and the ejector plate 46. By leaving the gap g' between the support member 50 and the ejector plate 46, friction between the two is avoided.

[0071] Figure 8 It is a plan view of the mold opening and closing device 16 when the ejector plate 46 is supported by the support member 50 , the mounting plate 38 , and the movable platen 34 . Figure 9 yes Figure 8 A side view of the metal mold opening and closing device 16.

[0072] like Figure 8 as well as Figure 9 As shown, the gap g' can be filled by retracting the ejector plate 46 from the advanced position Po1. Hereinafter, the position of the ejector plate 46 in contact with the support member 50 inserted into the gap g is referred to as "pressure receiving position Po2."

[0073] The ejector plate 46 retreated to the pressure receiving position Po2 is supported from the opening direction by the support member 50, the mounting plate 38, and the movable platen 34. In this state, the ejector plate 46 is prevented from retreating by the support member 50, the mounting plate 38, and the movable platen 34.

[0074] Furthermore, when it is desired to provide a hole portion in the molded product, it is sufficient to pre-set a nesting hole (not shown) in the fixed mold 12a through which the ejector pin 44 can be inserted. The nesting hole is a hole that receives the ejector pin 44 protruding from the fixed mold 12a side. In the case of this embodiment, the nesting hole needs to have a depth that allows the ejector pin 44 to pass when the ejector plate 46 is in the advanced position Po1. Thus, when it is desired to provide a hole portion in the molded product, the ejector plate 46 can be advanced to the advanced position Po1. In addition, the pressure position Po2 needs to be determined so that the ejector pin 44 does not fall out of the nesting hole when the ejector plate 46 retreats to the pressure position Po2. Thus, even when the ejector plate 46 retreats to the pressure position Po2, the ejector pin 44 can be maintained in a state of penetrating the resin R in the mold 12.

[0075] The above is an example of the configuration of the injection device 14, the mold opening and closing device 16, the ejector device 20, and the insertion and extraction device 22. Next, the control device 24 that controls these will be described.

[0076] Figure 10 2 is a block diagram of the control device 24 according to the embodiment.

[0077] The control device 24 is configured as, for example, a numerical control device (CNC) that numerically controls the injection molding machine 10. The control device 24 includes a storage unit 54 and a calculation unit 56.

[0078] The storage unit 54 stores information. The storage unit 54 is composed of, for example, a memory such as RAM (Random Access Memory) or ROM (Read Only Memory). The storage unit 54 of this embodiment stores a predetermined control program 58 in advance.

[0079] The control program 58 is a program that defines a control method (hereinafter simply referred to as "control method") for the injection molding machine 10 that can reliably mold a molded product having a concave shape. The structure of the control method will be described later.

[0080] The computing unit 56 processes information through calculations. The computing unit 56 is comprised of a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In this embodiment, the computing unit 56 includes a pressure acquisition unit 60, a timer 62, an injection control unit 64, an opening and closing control unit 65, an ejection control unit 66, and an insertion control unit 68. These components are implemented by the computing unit 56 reading and executing the control program 58 described above.

[0081] The pressure acquisition unit 60 acquires the resin pressure Pr. In this embodiment, a load sensor 70 is provided on the screw 28, and the resin pressure Pr is acquired from the load sensor 70. In this case, the load sensor 70 is attached to the end portion of the screw 28 on the closing direction side (see Figure 1 ).

[0082] The timing unit 62 measures time and is a so-called timer. The timing unit 62 of this embodiment includes an advance timing unit 72 and an insertion timing unit 74, each of which measures time at different timings based on a request from the ejection control unit 66. The advance timing unit 72 measures the time elapsed since the ejection plate 46 began moving from the retracted position Po0 to the advanced position Po1 (advance time) t1. The insertion timing unit 74 measures the time elapsed since the support member 50 began to be inserted (insertion time) t2 after the ejection pin 44 protrudes.

[0083] The injection control unit 64 performs measurement and injection of the resin R by controlling the motor 28 a and the motor 28 b of the injection device 14 .

[0084] The metering is a control to store a predetermined amount of resin R injected into the mold 12 on the nozzle 30 side in the cylinder 26. The injection control unit 64 can pressure-feed the resin R supplied from the supply port 32 toward the nozzle 30 side in the cylinder 26 by rotating the screw 28 in a predetermined rotation direction.

[0085] After completing the measurement, the injection control unit 64 maintains the resin pressure Pr below a predetermined standby pressure Pr0. The standby pressure Pr0 is a target value for adjusting the resin pressure Pr, set so that the measured resin R does not leak (deepen) from the cylinder 26 through the nozzle 30. In this embodiment, it is set to zero (atmospheric pressure). However, the standby pressure Pr0 is not limited to this and may, for example, be near zero. The standby pressure Pr0 is pre-stored in the storage unit 54, for example, so that the injection control unit 64 can refer to it as appropriate.

[0086] When the resin pressure Pr exceeds the standby pressure Pr0, the injection control unit 64 retracts the screw 28. This allows the injection control unit 64 to reduce the resin pressure Pr. Furthermore, the injection control unit 64 can also reduce the resin pressure Pr by rotating the screw 28 in the opposite direction to that used when the resin R is pumped toward the nozzle 30.

[0087] On the other hand, when the resin pressure Pr is lower than the standby pressure Pr0, the injection control unit 64 may advance the screw 28 so that the resin pressure Pr does not exceed the standby pressure Pr0. This allows the injection control unit 64 to increase the resin pressure Pr. Furthermore, the injection control unit 64 can also increase the resin pressure Pr by rotating the screw 28 in the same direction as when the resin R is pumped toward the nozzle 30.

[0088] Injection is a control that pressure-feeds a measured, predetermined amount of resin R from the cylinder 26 into the mold 12 via the nozzle 30. The injection control unit 64 advances the screw 28 to pressure-feed the resin R from the cylinder 26 into the mold 12. Furthermore, the injection control unit 64 can also rotate the screw 28 at this time. By executing injection, the resin pressure Pr rises from the standby pressure Pr0 to the target pressure Pr1. Specifically, by pressure-feeding the resin R using the screw 28, the resin pressure Pr rises from the standby pressure Pr0 to the target pressure Pr1.

[0089] After the injection is completed, the injection control unit 64 maintains the resin pressure Pr at the target pressure Pr1 while referring to the resin pressure Pr obtained by the pressure acquisition unit 60. That is, after completing the filling of the resin R into the metal mold 12, the injection control unit 64 maintains the resin pressure Pr at the target pressure Pr1 while referring to the resin pressure Pr obtained by the pressure acquisition unit 60. At this time, the injection control unit 64 can maintain the resin pressure Pr at the target pressure Pr1 by controlling the advance, retreat and rotation of the screw 28, as in the case of maintaining the resin pressure Pr at the standby pressure Pr0. For example, the injection control unit 64 drives the motor 28b to maintain the position of the screw 28 so that the screw 28 is not squeezed and retreated by the resin R that attempts to flow back from the metal mold 12, thereby suppressing the decrease in the resin pressure Pr.

[0090] However, it is preferred that the injection control unit 64 maintains the resin pressure Pr at a level lower than the predetermined target pressure Pr1 (and at or above the standby pressure Pr0) after the injection starts until the elapsed time t2 measured by the insertion timing unit 74 reaches at least the predetermined hold release time Tb. The reason for this will be explained later. The timing for adjusting the resin pressure Pr after the start of injection to reach the target pressure Pr1 can be achieved, for example, by appropriately adjusting the forward speed and rotational speed of the screw 28 during the injection. In other words, the timing for completing the filling of the resin R into the metal mold 12 can be achieved, for example, by appropriately adjusting the forward speed and rotational speed of the screw 28 during the injection.

[0091] After reaching a predetermined target pressure Pr1, the resin pressure Pr is preferably maintained at or above the target pressure Pr1 until at least the resin R provided in the inlet portion of the mold 12 solidifies (gate sealing). This prevents the resin R from flowing back from the mold 12 to the injection device 14. After the resin R in the mold 12 solidifies, the mold 12 is opened, allowing the operator of the injection molding machine 10 to obtain a molded product made of the solidified resin R.

[0092] The opening and closing control unit 65 controls the opening and closing of the mold 12 by controlling the mold opening and closing device 16. The opening and closing control unit 65 controls the driving of the motor 36a of the mold opening and closing device 16, causing the movable platen 34 to reciprocate between the mold opening position and the mold closing position. This controls the opening and closing of the mold 12.

[0093] The ejection control unit 66 controls the movement of the ejector plate 46 to project the ejector pin 44 into the mold 12 before the resin R in the mold 12 solidifies. The specific timing of the projection is set appropriately, but if the projection is performed when the filling rate of the resin R in the mold 12 is low, there is a high possibility of forming defects such as weld lines. Therefore, it is preferable to set the timing of the projection so that there is sufficient space within the mold 12 for the ejector pin 44 to enter and after the resin R has filled the mold 12 to a certain extent.

[0094] After moving the ejector plate 46 to the advanced position Po1, the ejector control unit 66 maintains the ejector plate 46 at the advanced position Po1 until the elapsed time t2 measured by the insertion timer 74 reaches the predetermined hold release time Tb. Furthermore, when the elapsed time t2 reaches the predetermined hold release time Tb, the ejector plate 46 is retracted to the pressed position Po2.

[0095] The predetermined hold release time Tb is information pre-stored in the storage unit 54 so that the ejection control unit 66 can refer to it as appropriate. The predetermined hold release time Tb is appropriately determined so that the ejection control unit 66 can continuously maintain the position of the ejector plate 46 from the time the ejection pin 44 protrudes until the support member 50 is inserted into the gap g.

[0096] As described above, the ejection control unit 66 requests the timer 62 to start counting the elapsed time t1 and the elapsed time t2. The ejection control unit 66 requests the start of counting the elapsed time t1 when the ejection control unit 66 advances the ejection plate 46 from the retracted position Po0. Furthermore, the ejection control unit 66 requests the start of counting the elapsed time t2 when the ejection plate 46 reaches the advanced position Po1.

[0097] The insertion control unit 68 controls the insertion and removal of the support member 50 so that the support member 50 is inserted between the mounting plate 38 and the ejector plate 46 after the ejector pin 44 protrudes. The insertion control unit 68 determines whether the ejector pin 44 protrudes based on the elapsed time t1 measured by the advance timer 72.

[0098] Specifically, the ejection control unit 66 starts moving the ejection plate 46 toward the advanced position Po1, and the timing of the elapsed time t1 is started. When the elapsed time t1 reaches the predetermined insertion start time Ta, the insertion control unit 68 controls the insertion and extraction device 22 to move the support member 50 in the insertion direction (upward).

[0099] The scheduled insertion start time Ta is information pre-stored in the storage unit 54 so that the insertion control unit 68 can appropriately refer to it. The scheduled insertion start time Ta is appropriately determined so that the support member 50 does not collide with the lower end of the ejector plate 46 after the support member 50 starts to be inserted.

[0100] Thus, the support member 50 is inserted between the mounting plate 38 and the ejector plate 46. In addition, the timing of the elapsed time t2 is started when the support member 50 starts moving in the insertion direction.

[0101] The above is an example of the configuration of the control device 24 of this embodiment. Next, the flow of the control method executed by the control device 24 will be described.

[0102] Figure 11 This is a flowchart illustrating the flow of the control method according to the embodiment.

[0103] like Figure 11 As shown, the control method includes: an injection control step S1, an ejection advancement step S2, an insertion control step S3, an ejection support step S4 and a pressure holding control step S5.

[0104] The injection control step S1 is a step of injecting resin R into the closed metal mold 12 by controlling the injection device 14. This step is executed by the injection control unit 64 controlling the advance, retreat, and rotation of the screw 28. This step is executed on the premise that the measurement of the resin R is completed.

[0105] Figure 12 It is a timing chart illustrating the transition of the resin pressure Pr in the metal mold 12, the position of the ejector plate 46 in the opening and closing directions, and the position of the support member 50 in the insertion and removal directions, respectively, for illustrating the control method.

[0106] Figure 12 T0 indicates the start time of the injection control step S1. The resin pressure Pr is adjusted to the standby pressure Pr0 before T0, and becomes higher than the standby pressure Pr0 after T0 when the injection control step S1 starts. The injection control step S1 continues until T5.

[0107] Ejector advancement step S2 is a step in which, after the injection control step S1 is initiated, ejector plate 46 is advanced, thereby causing ejector pins 44 to project into mold 12, thereby imparting at least one of a recess and a hole to the shape of resin R within mold 12. This step is executed by ejector control unit 66.

[0108] The time period for performing the ejection forward step S2 is Figure 12 The middle is T1 to T2. T1 is behind T0, and T2 is before T5. Figure 12 Ta exemplifies the length of time from T1 to the predetermined insertion start time Ta.

[0109] The insertion control step S3 is a step of controlling the insertion and extraction of the support member 50 so as to insert the support member 50 between the mounting plate 38 and the ejector plate 46 after the ejector pin 44 projects. This step is executed by the insertion control unit 68 .

[0110] The time period for performing the insertion control step S3 is Figure 12 The middle ones are T2~T3. Figure 12 Tb illustrates the length of time from T2 to the predetermined hold release time Tb. Figure 12 The withdrawal position is a predetermined initial position of the support member 50 when starting to move toward the gap g, and the insertion position is a target position of the support member 50 toward the gap g.

[0111] The ejection support step S4 is a step in which the ejector plate 46 is retracted from the advanced position Po1 to the pressed position Po2. This step supports the ejector plate 46 from the opening direction by the support member 50, the mounting plate 38, and the movable platen 34. This step is performed by the ejection control unit 66 after the time t2 reaches the predetermined hold release time Tb.

[0112] The time period for performing the ejection support step S4 is Figure 12 T3 to T4 are in the range of 0.1 to 0.1. T4 is earlier than T5. That is, the ejection support step S4 is completed before the resin pressure Pr reaches the target pressure Pr1, similarly to the ejection advancement step S2 and the insertion control step S3.

[0113] The pressure holding control step S5 is a step for maintaining the resin pressure Pr within the mold 12 at or above a predetermined target pressure Pr1 while the support member 50 and the mounting plate 38 support the ejector plate 46. This step is performed by the injection control unit 64 controlling the advance, retreat, and rotation of the screw 28 while referencing the resin pressure Pr. The resin pressure Pr referenced by the injection control unit 64 is appropriately acquired by the pressure acquisition unit 60 in this step.

[0114] The pressure control step S5 is Figure 12 In the example, it starts from T5 and lasts for a predetermined time ( Figure 12 During this period, the resin pressure Pr is maintained above the predetermined target pressure Pr1. This allows the gate to be sealed. After the gate is sealed, the resin pressure Pr can be reduced to less than the predetermined target pressure Pr1.

[0115] According to the above control method, a molded product having a concave shape can be molded with high reliability. The reason is as follows.

[0116] That is, after the resin pressure Pr reaches the target pressure Pr1 in the pressure holding control step S5, it is maintained at or above the target pressure Pr1 until the gate is sealed. This target pressure Pr1 is applied to the ejector pins 44 protruding into the mold 12 through the resin R, and is also applied to the ejector plate 46 supporting the ejector pins 44 through the resin R.

[0117] Here, if the ejector plate 46 is not supported from the opening direction by the support member 50, the ejector pin 44, which is subjected to the resin pressure Pr exceeding the target pressure Pr1, may be pushed out from the mold 12 toward the opening direction before the resin R solidifies. In this case, a molded product having a concave (hole) shape cannot be formed with high quality.

[0118] In this regard, in this embodiment, the ejector plate 46, which is subjected to the resin pressure Pr exceeding the target pressure Pr1 via the ejector pins 44, is supported by the support member 50, the mounting plate 38, and the movable platen 34. This maintains the proper positions of the ejector plate 46 and the ejector pins 44, allowing a high-quality molded product having a concave shape to be reliably formed.

[0119] Furthermore, in this embodiment, the ejector plate 46's position is maintained by the ejector control unit 66 until a predetermined hold release time Tb for the following reason. Specifically, in this embodiment, after the hold release time Tb, the ejector plate 46 is supported by the support member 50, the mounting plate 38, and the movable platen 34. Therefore, while the ejector plate 46 and the ejector pins 44 are subjected to a resin pressure Pr exceeding the target pressure Pr1, the position of the ejector plate 46 can be maintained even without activating the first direct-acting mechanism 48. This eliminates the need for the first direct-acting mechanism 48 to generate an output sufficient to maintain the position of the ejector plate 46 against the resin pressure Pr exceeding the target pressure Pr1. This, for example, contributes to reducing the energy consumption of the first direct-acting mechanism 48.

[0120] As described above, according to the present embodiment, there are provided the control device 24 of the injection molding machine 10 and the control method of the injection molding machine 10 that can reliably mold a molded product having a concave shape.

[0121] [Modification]

[0122] The above is an example of an embodiment of the present invention. Various changes or improvements can be applied to the above embodiment. In addition, according to the description of the scope of the patent protection requested, it can be seen that the method of applying such changes or improvements can be included in the technical scope of the present invention.

[0123] Several modified examples of the embodiment will be specifically described below, but descriptions of matters overlapping with the embodiment will be omitted as appropriate.

[0124] (Variation 1)

[0125] The control device 24 can also execute control for removing the molded product from the mold 12 after the resin R in the mold 12 has solidified, and for extracting the support member 50 from between the mounting plate 38 and the ejector plate 46. The control device 24 capable of executing such control will be described below.

[0126] Figure 13 3 is a structural diagram of the ejection device 20 according to the first modification. Figure 13 is with Figure 3 Same observation point.

[0127] Before explaining the control device 24 of this modified example, the configuration example of the ejection device 20 as the control object will be explained. Figure 13 As shown, the ejection device 20 in this modified example further includes a protruding plate 76 , a protruding pin 78 , and an elastic member 80 .

[0128] The protruding plate 76 is a plate that supports the protruding pin 78 on the opposite side of the mold 12. The protruding plate 76 is provided in the ejection movable space 42 and on the closing direction side of the ejection plate 46 at the advanced position Po1, avoiding the ejection pin 44.

[0129] The protruding pin 78 is a pin provided for protruding and removing the molded product from the open mold 12. Figure 3 ) Similarly, Figure 13 The illustrated ejector pin 78 is flush with the inner surface of the movable mold 12 b when not protruding into the mold 12 .

[0130] The elastic member 80 is a member provided between the protruding plate 76 and the movable metal mold 12b, and is compressed by the protruding plate 76 moving in the closing direction, and has elasticity to generate a rebound force against the compression. Figure 13 In the embodiment, a compression spring is illustrated as a specific example of the elastic member 80 , but the elastic member 80 is not limited to a compression spring as long as it is a member that generates a rebound force in response to compression in the opening and closing directions.

[0131] Figure 14 It is a diagram for explaining protrusion of a molded product by the ejector device 20 according to the first modification. Figure 14 is with Figure 13 Same observation point.

[0132] According to the above ejection device 20, as Figure 14 As shown, by pressing the protruding plate 76 toward the closing direction with the ejector plate 46, the protruding pin 78 can be protruded toward the metal mold 12. This allows the molded product (solidified resin R) to be removed from the metal mold 12. The position at which the ejector plate 46 reaches when advancing to press the protruding plate 76 can be predetermined. In this modified example, this position is also referred to as "protruding position Po3."

[0133] The protruding plate 76 moved in the closing direction can be returned to its original position by the elastic member 80. That is, when the ejector plate 46 is retracted from the protruding position Po3, Figure 14 The protruding plate 76 can return to its original position by the force in the opening direction received from the elastic member 80 (see Figure 13 ).

[0134] Figure 15 This is a configuration diagram of the control device 24 according to Modification 1.

[0135] The configuration example of the control device 24 of this modification example will be described. Figure 15 As shown, the control device 24 of this modified example further includes a mold opening timing unit 82 and a pull-out control unit 84. The control device 24 of this modified example is at least structurally similar to the embodiment ( Figure 10 ) is different. In addition, the control program 58 can be stored in the storage unit 54 in the same manner as in the embodiment, but its content can be appropriately changed to match the structure of the calculation unit 56 of this modification.

[0136] The mold opening timer 82 measures the elapsed time (mold opening time) t3 from the start of mold opening of the mold 12. The elapsed time t3 is referred to by the ejection control unit 66 and the extraction control unit 84.

[0137] Figure 16 It is a timing chart illustrating transitions of the position of the movable platen 34 in the opening and closing directions, the position of the ejector plate 46 in the opening and closing directions, and the position of the support member 50 in the insertion and removal directions according to Modification 1.

[0138] Figure 16 T6 illustrates the starting point of the timing of the mold opening timing unit 82. That is, Figure 16 T6 exemplifies the start time of opening the metal mold 12. At the time of T6, the resin R in the metal mold 12 is sufficiently cured.

[0139] In association with the elapsed time t3, the ejection control unit 66 performs the same control as in the embodiment and further performs the following control. That is, when the elapsed time t3 reaches the predetermined extraction start time Tc, the ejection control unit 66 advances the ejection plate 46 to the protruding position Po3 (see Figure 16 Thus, the protruding plate 76 is extruded, and the protruding pin 78 causes the molded product to protrude.

[0140] The scheduled extraction start time Tc is information appropriately determined so that the movement of the ejector plate 46 toward the protruding position Po3 begins after the mold 12 has opened to a certain extent. The scheduled extraction start time Tc is pre-stored in the storage unit 54. The scheduled extraction start time Tc is appropriately referenced by the ejection control unit 66.

[0141] The ejection control unit 84 starts moving the ejector plate 46 forward when the mold 12 is opened ( Figure 16 The support member 50 is pulled out from between the mounting plate 38 and the ejector plate 46.

[0142] The advancement of the ejector plate 46 during mold opening of the mold 12 refers to advancement toward the aforementioned protruding position Po3. Whether the advancement of the ejector plate 46 during mold opening of the mold 12 has begun can be determined by, for example, the extraction control unit 84 by referring to the elapsed time t3 and the predetermined extraction start time Tc, similar to the ejection control unit 66. Alternatively, for example, when the ejection control unit 66 initiates advancement of the ejector plate 46, the ejection control unit 84 can be notified of this fact.

[0143] When the ejector plate 46 starts to advance toward the protruding position Po3, the gap g′ (see FIG. 1 ) that was filled by the execution of the ejection support step S4 is generated again between the ejector plate 46 and the support member 50. Figure 14 ).

[0144] The extraction control unit 84 extracts the support member 50 after the gap g′ is generated, thereby preventing the support member 50 and the ejector plate 46 from rubbing against each other.

[0145] In addition, the movement of the ejector plate 46 to the protruding position Po3 and the extraction of the support member 50 may be performed after the movable platen 34 reaches the mold opening position (at Figure 16 (in the middle, it starts from T8 and above).

[0146] (Variation 2)

[0147] Insertion control step S3 may also be initiated before ejection advancement step S2 is completed. In this case, it is preferable to set the start timing of insertion control step S3 so that the inserted support member 50 does not collide with the lower end of the advancing ejector plate 46. This start timing can be appropriately determined based on, for example, the moving speed of the advancing ejector plate 46 and the moving distance and moving speed of the inserted support member 50.

[0148] (Variation 3)

[0149] In the embodiment and the above-described modifications, the control device 24 has been described as performing various controls based on the time measured by the timer unit 62. However, the configuration of the control device 24 is not limited thereto.

[0150] Figure 17 It is a structural diagram of the control device 24 of Modification 3.

[0151] like Figure 17 As shown, the control device 24 of this modified example includes: an advance position acquisition unit 86, an insertion position acquisition unit 88, and a movable platen position acquisition unit 90. Figure 17 As shown, in this modification, the timing unit 62 (advance timing unit 72, insertion timing unit 74, and mold opening timing unit 82) described in the embodiment and other modifications can be omitted from the structure of the control device 24. Furthermore, as in the first modification, the content of the control program 58 is appropriately modified to match the structure of the calculation unit 56 of this modification.

[0152] The forward position acquisition unit 86 acquires a position Po46 in the moving direction of the ejector plate 46. Furthermore, the insertion position acquisition unit 88 acquires a position Po50 in the insertion direction of the support member 50. Furthermore, the movable platen position acquisition unit 90 acquires a position Po34 of the movable platen 34 in the opening direction of the mold 12. These acquired positions Po46, Po50, and Po34 can be acquired based on the detection results of a position sensor appropriately provided in the injection molding machine 10 to detect the position of the detection target.

[0153] Figure 18 It is a timing chart illustrating the transitions of the position Po34 of the movable platen 34 in the opening and closing direction, the position Po46 of the ejector plate 46 in the opening and closing direction, the position Po50 of the support member 50 in the insertion and removal direction, and the resin pressure Pr in the metal mold 12 according to Modification Example 3.

[0154] See also below Figure 18 , the control performed by the insertion control unit 68, the ejection control unit 66, and the extraction control unit 84 will be described in sequence.

[0155] First, the insertion control unit 68 of this modification will be described. In this modification, when the ejection plate 46 reaches the predetermined insertion start position Po4, the insertion control unit 68 starts the insertion control step S3 described in the embodiment. Figure 18 As shown, in this modification, when the ejector plate 46 that has advanced reaches the predetermined insertion start position Po4 , the insertion control unit 68 inserts the support member 50 into the gap g between the mounting plate 38 and the ejector plate 46 .

[0156] The predetermined insertion start position Po4 is a predetermined position between the retracted position Po0 and the forward position Po1. Figure 18 T3' in FIG. 4 illustrates the time point at which the ejector plate 46 reaches the predetermined insertion start position Po4. Figure 18 As shown, the ejector plate 46 passes through a predetermined insertion start position Po4 during the period between T1 and T2 (ejector advancement step S2 ) when moving from the retracted position Po0 to the advanced position Po1 .

[0157] The predetermined insertion start position Po4 can be pre-stored in the storage unit 54. Whether the ejector plate 46 has reached the predetermined insertion start position Po4 can be determined by the insertion control unit 68 based on the position Po46 acquired by the advanced position acquisition unit 86. Furthermore, the predetermined insertion start position Po4 may be the same position as the advanced position Po1 or the pressure-receiving position Po2.

[0158] Next, the ejection control unit 66 of this modified example will be described. The ejection control unit 66 maintains the position of the ejection plate 46 at the advanced position Po1 until the support member 50 reaches the predetermined hold release position Po5 in the insertion direction. The positional relationship between the ejection plate 46 and the support member 50 during this period is, for example, similar to Figure 7 Same.

[0159] The predetermined hold release position Po5 can be pre-stored in the storage unit 54. Whether the support member 50 has reached the predetermined hold release position Po5 in the insertion direction can be determined by the ejection control unit 66 based on the position Po50 acquired by the insertion position acquisition unit 88. Figure 18 T4 ′ exemplifies a time point when the support member 50 reaches a predetermined hold release position Po5 in the insertion direction.

[0160] When the support member 50 reaches the predetermined release position Po5, the ejection control unit 66 starts the ejection support step S4 described in the embodiment. Specifically, when the support member 50 reaches the predetermined release position Po5, the ejection control unit 66 retracts the ejection plate 46 to the pressure receiving position Po2.

[0161] Therefore, with Figure 8 Similarly, the ejector plate 46 can be supported by the support member 50. Thereafter, the injection control unit 64 controls the resin pressure Pr to reach the target pressure Pr1 in the same manner as in the embodiment to achieve gate sealing (pressure holding control step S5).

[0162] Furthermore, after T4', it is preferable that the timing at which the support member 50 reaches the insertion position coincides with the timing at which the ejector plate 46 retreats to the pressure-receiving position Po2. Alternatively, it is preferable that the timing at which the support member 50 reaches the insertion position precedes the timing at which the ejector plate 46 retreats to the pressure-receiving position Po2. This prevents friction between the support member 50 and the ejector plate 46.

[0163] Finally, the extraction control unit 84 of this modification will be described. When the movable platen 34 reaches a predetermined extraction start position Po6 in the opening direction, the extraction control unit 84 extracts the support member 50 from between the mounting plate 38 and the ejection plate 46.

[0164] The predetermined extraction start position Po6 is information that can be pre-stored in the storage unit 54. Whether the movable platen 34 has reached the predetermined extraction start position Po6 in the opening direction can be determined by the extraction control unit 84 based on the position Po34 acquired by the movable platen position acquisition unit 90. Figure 18 T7' exemplifies the time point when the movable platen 34 reaches the predetermined extraction start position Po6 in the opening direction.

[0165] The control device 24 of this modification example can also mold a molded product having a recessed portion (hole portion) with high reliability, similarly to the embodiment.

[0166] Furthermore, the timer unit 62, the forward position acquisition unit 86, the insertion position acquisition unit 88, and the movable platen position acquisition unit 90 may be combined as appropriate. For example, the insertion control unit 68 may perform control based on the elapsed time t1, while the ejection control unit 66 may perform control based on the position Po50 of the support member 50.

[0167] (Variation 4)

[0168] Figure 19 This is a structural diagram when the support member 50 of Modification 4 is viewed from the opening and closing direction.

[0169] The structure of the support member 50 that can avoid collision with the ejection rod 48e is not limited to the embodiment ( Figure 6 ). The supporting member 50 may also be a combination of multiple plate members. Such a supporting member 50 is, for example, Figure 19 As shown, a pair of plate members 50A and 50B are configured to be spaced apart from each other in the left-right direction.

[0170] according to Figure 19 When the supporting member 50 is inserted into the gap g in the vertical direction, Figure 6 The supporting member 50 can also avoid the ejection rod 48e.

[0171] In addition, in addition to Figure 19 In addition, the support member 50 is not limited to a plate shape, and may be a block-shaped member, for example.

[0172] (Variant 5)

[0173] The insertion direction of the support member 50 is not limited to the upper direction described in the embodiment. For example, the support member 50 can be inserted into the gap g by moving it from the upper direction to the lower direction of the gap g. In this case, the support member 50 (plug-in device 22) can be set above the metal mold 12. Alternatively, the support member 50 can be inserted from the left or right direction of the gap g. In this case, the support member 50 (plug-in device 22) can be set to the left or right direction of the metal mold 12. In addition, like the insertion direction, the removal direction of the support member 50 is not limited to the lower direction described in the embodiment.

[0174] (Variation 6)

[0175] The detection means of the resin pressure Pr is not limited to the load cell 70 attached to the screw 28. For example, a mold internal pressure sensor (pressure sensor) may be provided in the mold 12 to obtain the resin pressure Pr from the mold internal pressure sensor.

[0176] (Variant 7)

[0177] The injection molding machine 10 of the embodiment includes the injection device 14 which is also called an inline type, but the injection device 14 is not limited to the inline type.

[0178] Similarly, the injection molding machine 10 of the embodiment realizes opening and closing of the mold 12 (movement of the movable platen 34 ) by a so-called elbow-type toggle mechanism 36 , but the mechanism for opening and closing the mold 12 is not limited to the toggle type.

[0179] (Variation 8)

[0180] The control device 24 can also be applied to a vertical injection molding machine 10. In a vertical injection molding machine 10, the direction of gravity corresponds to the direction of opening and closing of the mold 12. In this case, the ejector plate 46 advances and retreats in the direction of gravity. Furthermore, the gap g expands in the direction of gravity as the ejector plate 46 advances.

[0181] The insertion and removal direction of the support member 50 in this modification can be appropriately determined in such a way that the support member 50 can be inserted and removed relative to the gap g that expands along the gravity direction. For example, without limitation thereto, the insertion direction can be set to the left direction and the removal direction can be set to the right direction. Figure 1 The opening and closing direction is used as the plugging and unplugging direction of this variation.

[0182] (Variant 9)

[0183] The above-described modifications may be appropriately combined within a range where no contradiction occurs.

[0184] [Inventions derived from the embodiments]

[0185] The invention that can be grasped based on the above-mentioned embodiment and modified examples will be described below.

[0186] <First Invention>

[0187] 14. The control device 24 of an injection molding machine 10 includes: a movable platen 34 that moves in the opening and closing direction of a metal mold 12; a mounting plate 38 that is provided on the metal mold 12 side of the movable platen 34; a spacer 40 that connects the metal mold 12 and the mounting plate 38 so that the metal mold 12 opens and closes as the movable platen 34 moves in the opening and closing direction, and forms an ejection movable space 42 between the metal mold 12 and the mounting plate 38; an ejector plate 46 that is provided in the ejection movable space 42 and moves forward and backward relative to the metal mold 12; an ejector pin 44 that is provided on the ejector plate 46 and protrudes toward the metal mold 12; a support member 50 that is inserted into and removed from a gap g between the mounting plate 38 and the advancing ejector plate 46; and an injection unit 14 that injects plasticized resin R. The control device 24 includes: a pressure acquisition unit 60, which acquires the resin pressure Pr in the metal mold 12; an injection control unit 64, which controls the injection unit 14 to inject the resin R into the closed metal mold 12 and make the resin pressure Pr reach a predetermined target pressure Pr1; an ejection control unit 66, which advances the ejector plate 46 before the resin pressure Pr reaches the predetermined target pressure Pr1, thereby causing the ejector pin 44 to protrude into the mold 12 and giving at least one of a recess and a hole to the shape of the resin R in the metal mold 12; and an insertion control unit 68, which inserts the support member 50 into the gap g before the resin pressure Pr reaches the predetermined target pressure Pr1, thereby supporting the ejector plate 46 subjected to the resin pressure Pr on the support member 50 and the mounting plate 38.

[0188] Thus, the control device 24 of the injection molding machine 10 is provided, which can reliably mold a molded product having a concave shape and a hole.

[0189] Alternatively, the system may further include an advancement timing unit 72 that measures advancement time t1, the time elapsed from the time the ejector plate 46 begins advancing before the resin pressure Pr reaches the predetermined target pressure Pr1. The insertion control unit 68 inserts the support member 50 into the gap g when the advancement time t1 reaches the predetermined insertion start time Ta. This facilitates adjusting the insertion timing of the support member 50 after the gap g has sufficiently expanded. Consequently, collision between the inserted support member 50 and the advancing ejector plate 46 can be prevented.

[0190] Alternatively, the system may further include an advanced position acquisition unit 86 that acquires the position of the ejector plate 46 in the opening and closing direction, and the insertion control unit 68 inserts the support member 50 into the gap g when the ejector plate 46 reaches the predetermined insertion start position Po4 before the resin pressure Pr reaches the predetermined target pressure Pr1. This facilitates adjusting the insertion timing of the support member 50 after the gap g has sufficiently expanded. Consequently, collision between the inserted support member 50 and the advancing ejector plate 46 can be prevented.

[0191] Alternatively, the system may further include an insertion timing unit 74 that measures insertion time t2, which is the time elapsed since the support member 50 began moving toward the gap g. The ejection control unit 66 maintains the position of the ejector plate 46 in the opening and closing direction at a predetermined advanced position Po1 on the mold 12 side relative to the support member 50 until the insertion time t2 reaches a predetermined hold release time Tb, and releases the hold after the insertion time t2 reaches the predetermined hold release time Tb. Consequently, the ejector plate 46 does not retract when the support member 50 is inserted into the gap g, thereby enabling the support member 50 to be properly inserted into the gap g. Furthermore, the burden on the ejector plate 46's drive device (first linear motion mechanism 48) can be reduced after the support member 50 is inserted into the gap g.

[0192] Alternatively, the ejection control unit 66 may further include an insertion position acquisition unit 88 that acquires the position of the support member 50 in the insertion direction. The ejection control unit 66 maintains the position of the ejector plate 46 in the opening and closing direction at the predetermined advanced position Po1, which is closer to the mold 12 than the support member 50, until the support member 50 reaches the predetermined release position Po5, moving toward the gap g. The ejection control unit 66 releases the release position after the support member 50 reaches the predetermined release position Po5. Consequently, the ejector plate 46 does not retract when the support member 50 is inserted into the gap g, thereby enabling the support member 50 to be properly inserted into the gap g. Furthermore, the burden on the ejector plate 46's drive device (first linear motion mechanism 48) can be reduced after the support member 50 is inserted into the gap g.

[0193] Alternatively, the injection control unit 64 may maintain the resin pressure Pr below the predetermined target pressure Pr1 until the ejector plate 46 is released from the predetermined advanced position Po1. This facilitates adjusting the timing at which the resin pressure Pr reaches the predetermined target pressure Pr1 to after the ejector plate 46 is supported by the support member 50.

[0194] Alternatively, the injection molding machine 10 may further include a protruding plate 76 disposed in the ejection movable space 42, closer to the mold 12 than the ejector plate 46, avoiding the ejector pin 44; and a protruding pin 78 disposed on the protruding plate 76 and protruding toward the mold 12. When the mold 12 is opened, the ejection control unit 66 advances the ejector plate 46 to press the protruding plate 76 toward the mold 12 so that the molded product made of the solidified resin R can be protruded from the mold 12 using the protruding pin 78. The control device 24 may further include a removal control unit 84 that removes the support member 50 from between the mounting plate 38 and the ejector plate 46 after the ejector plate 46 begins advancing when the mold 12 is opened. Thus, removal control of the support member 50 is performed after the support member 50 is separated from the ejector plate 46. As a result, it is possible to prevent the support member 50 and the ejection plate 46 from rubbing against each other when the support member 50 is pulled out.

[0195] Alternatively, the mold may further include a mold opening timing unit 82 that measures a mold opening time t3, which is the time elapsed from the start of mold opening. When the mold opening time t3 reaches a predetermined extraction start time Tc, the ejection control unit 66 advances the ejector plate 46 to press the protruding plate 76 into the mold 12. This prevents the molded product from being protruded by the protruding pin 78 before the mold 12 is fully opened.

[0196] Alternatively, the extraction control unit 84 may extract the support member 50 from between the mounting plate 38 and the ejector plate 46 when the mold opening time t3 reaches the predetermined extraction start time Tc. This prevents the support member 50 and the ejector plate 46 from rubbing against each other when the support member 50 is extracted.

[0197] Alternatively, the mold may further include a movable platen position acquisition unit 90 that acquires the position of the movable platen 34 in the opening and closing directions during mold opening, and the ejection control unit 66 advances the ejector plate 46 to press the protruding plate 76 toward the mold 12 when the movable platen 34 reaches a predetermined extraction start position Po6 during mold opening. This prevents the molded product from protruding due to the protruding pins 78 before the mold 12 is fully opened.

[0198] Alternatively, the extraction control unit 84 may extract the support member 50 from between the mounting plate 38 and the ejector plate 46 when the movable platen 34 reaches a predetermined extraction start position Po6 during mold opening. This prevents the support member 50 and the ejector plate 46 from rubbing against each other during the extraction of the support member 50.

[0199] <Second Invention>

[0200] A control method for an injection molding machine 10, the injection molding machine 10 comprising: a movable platen 34 that moves in the opening and closing direction of a metal mold 12; a mounting plate 38 that is provided on the metal mold 12 side of the movable platen 34; a spacer 40 that connects the mold 12 and the mounting plate 38 so that the metal mold 12 opens and closes as the movable platen 34 moves in the opening and closing direction, and forms an ejection movable space 42 between the metal mold 12 and the mounting plate 38; an ejector plate 46 that is provided in the ejection movable space 42 and moves forward and backward relative to the metal mold 12; an ejector pin 44 that is provided on the ejector plate 46 and projects toward the metal mold 12; a support member 50 that is inserted into and removed from a gap g between the mounting plate 38 and the advancing ejector plate 46; and an injection unit 14. , which injects plasticized resin R, the control method of the injection molding machine 10 includes: an injection control step, by controlling the injection part 14, injecting the resin R into the closed metal mold 12; an ejection advancement step, after the start of the injection control step, by advancing the ejector plate 46, the ejector pin 44 protrudes into the metal mold 12, thereby giving at least one of a concave portion and a hole portion to the shape of the resin R in the metal mold 12; an insertion control step, after the start of the ejection advancement step, inserting the support member 50 into the gap g; and a holding pressure control step, after the start of the insertion control step, causing the support member 50 and the mounting plate 38 to support the ejector plate 46, and causing the resin pressure Pr in the metal mold 12 to reach a predetermined target pressure Pr1.

[0201] Thus, a control method of the injection molding machine 10 is provided that can reliably mold a molded product having a concave shape and a hole.

Claims

1. A control device (24) for an injection molding machine (10), characterized in that: Injection molding machines have: A movable pressing plate (34) moves in the opening and closing direction of the metal mold (12); a mounting plate (38) provided on the metal mold side of the movable platen; a spacer (40) connecting the metal mold and the mounting plate in such a manner that the metal mold opens and closes as the movable platen moves in the opening and closing direction, and forming an ejection movable space (42) between the metal mold and the mounting plate; an ejector plate (46) disposed in the ejection movable space and capable of advancing and retreating relative to the metal mold; an ejector pin (44) provided on the ejector plate and protruding toward the metal mold; a supporting member (50) which is inserted and removed relative to the gap (g) between the mounting plate and the advancing ejector plate; as well as an injection portion (14) which injects plasticized resin (R), The control device of the injection molding machine comprises: a pressure obtaining unit (60) for obtaining the resin pressure (Pr) in the metal mold; an injection control unit (64) for injecting the resin into the closed metal mold by controlling the injection unit and causing the resin pressure to reach a predetermined target pressure (Pr1); an ejection control unit (66) which advances the ejector plate before the resin pressure reaches the predetermined target pressure, thereby causing the ejector pin to project into the metal mold and thereby imparting at least one of a concave portion and a hole portion to the shape of the resin in the metal mold; as well as An insertion control unit (68) inserts the support member into the gap before the resin pressure reaches the predetermined target pressure, thereby supporting the ejector plate subjected to the resin pressure on the support member and the mounting plate.

2. The control device for an injection molding machine according to claim 1, wherein: The control device of the injection molding machine further comprises: an advancement timing unit (72) for timing an advancement time (t1) which is a time elapsed from when the ejector plate starts to advance until the resin pressure reaches the predetermined target pressure. The insertion control unit inserts the support member into the gap when the advancing time reaches a predetermined insertion start time (Ta).

3. The control device for an injection molding machine according to claim 1, wherein: The control device of the injection molding machine further comprises: a forward position acquisition unit (86) which acquires the position of the ejector plate in the opening and closing direction, When the ejector plate, which has advanced before the resin pressure reaches the predetermined target pressure, reaches a predetermined insertion start position (Po4), the insertion control unit inserts the support member into the gap.

4. The control device for an injection molding machine according to claim 1, wherein: The control device of the injection molding machine further comprises an insertion timing unit (74) for timing an insertion time (t2) which is a time elapsed from when the support member starts moving toward the gap. The ejection control unit maintains the position of the ejector plate in the opening and closing direction at a predetermined forward position (Po1) closer to the metal mold side than the support member until the insertion time reaches a predetermined hold release time (Tb), and releases the hold after the insertion time reaches the predetermined hold release time.

5. The control device for an injection molding machine according to claim 1, wherein: The control device of the injection molding machine further comprises: an insertion position acquisition unit (88) which acquires the position of the support member in the insertion direction, The ejection control unit maintains the position of the ejector plate in the opening and closing direction at a predetermined forward position (Po1) closer to the metal mold side than the support member until the support member moving toward the gap reaches a predetermined hold release position (Po5), and releases the hold after the support member reaches the predetermined hold release position.

6. The control device for an injection molding machine according to claim 4 or 5, characterized in that: The injection control unit maintains the resin pressure at a level lower than the predetermined target pressure until the ejector plate is released from being held at the predetermined advanced position.

7. A control method for an injection molding machine (10), characterized in that: Injection molding machines have: A movable pressing plate (34) moves in the opening and closing direction of the metal mold (12); a mounting plate (38) provided on the metal mold side of the movable platen; a spacer (40) connecting the metal mold and the mounting plate in such a manner that the metal mold opens and closes as the movable platen moves in the opening and closing direction, and forming an ejection movable space (42) between the metal mold and the mounting plate; an ejector plate (46) disposed in the ejection movable space and capable of advancing and retreating relative to the metal mold; an ejector pin (44) provided on the ejector plate and protruding toward the metal mold; a supporting member (50) that is inserted and removed relative to the gap (g) between the mounting plate and the advancing ejector plate; and an injection portion (14) which injects plasticized resin (R), The control method of the injection molding machine comprises: an injection control step of injecting the resin into the closed metal mold by controlling the injection unit; an ejection advancement step of advancing the ejector plate after the injection control step is started, thereby causing the ejector pin to project into the metal mold and imparting at least one of a concave portion and a hole portion to the shape of the resin in the metal mold; an insertion control step of inserting the support member into the gap after the ejection advancement step is started; as well as The holding pressure control step is to make the support member and the mounting plate support the ejector plate and make the resin pressure (Pr) in the metal mold reach a predetermined target pressure (Pr1) after the insertion control step is started.

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