JP5607124B2 - Ejector device - Google Patents

Description

  The present invention relates to an ejector device for projecting a molded product from a mold. More specifically, the present invention is connected to an ejector plate having an ejector pin provided on the mold side, and drives the ejector plate. The present invention relates to an ejector device having an ejector rod.

  As is well known in the art, an injection molding machine is composed of a pair of molds, a mold clamping device that clamps these molds, an injection device that melts a resin material and injects it into the mold. Therefore, when the mold is clamped by driving the mold clamping device, the molten resin in the injection device is injected into the cavity in the mold, and after waiting for cooling and solidification, the mold clamping device is driven to open the mold. Is obtained. The ejection of the molded product is performed by an ejector device. The ejector device is provided in the mold clamping device, and when the mold clamping device is a toggle type mold clamping device, the ejector device is provided on the opposite side of the surface of the movable platen or fixed platen to which the mold is attached. . More specifically, the horizontal type toggle type mold clamping device includes a stationary platen to which a stationary mold is fixed, a movable plate to which a movable mold is fixed, a clamping housing, and a stationary platen. A plurality of tie bars are connected to the mold clamping housing and inserted through the movable platen, and a toggle mechanism is provided between the mold clamping housing and the movable platen. In the case of such a toggle type mold clamping device, the ejector device is provided on the toggle mechanism side of the movable platen. On the other hand, in the case of a toggle type mold clamping device of a vertical injection molding machine, the toggle mechanism is provided between the stationary platen and the mold clamping housing, and the ejector device is provided on the toggle mechanism side of the stationary platen. The ejector device is provided with an ejector rod, and the ejector rod can be driven to the mold side through the movable platen or the fixed platen. An ejector plate having an ejector pin is provided in the mold, and the ejector plate is connected to an ejector rod of the ejector device. Therefore, when the ejector rod is driven in a state in which they are connected, the ejector pin protrudes from the mold and the molded product can be protruded.

JP 2010-23371 A

  Patent Document 1 describes an ejector device that can easily connect an ejector rod of an ejector device and an ejector plate in a mold. In this ejector device, the ejector rod is composed of a cylindrical sleeve portion and a rotating shaft portion penetrating the sleeve portion in the axial direction. Although the sleeve portion is restricted from rotating, the rotation shaft portion can be rotated in the sleeve portion, and a male screw is formed at the front end portion of the rotation shaft portion, and a hexagon head at the rear end portion. The part is formed. When a female screw is provided on the ejector plate of the mold, the rotating shaft is pressed against the female screw, and the hexagonal head is rotated by an impact wrench or the like, the male screw is screwed into the female screw. Thus, the rotating shaft portion and the ejector plate can be coupled. That is, the ejector rod of the ejector device and the ejector plate in the mold can be connected.

  The ejector device described in Patent Document 1 can also easily connect the ejector rod and the ejector plate in the mold. That is, it is possible to connect the ejector rod and the ejector plate simply by inserting a tool such as an impact wrench on the rear side of the ejector device and rotating the rotating shaft portion constituting the ejector rod. Accordingly, the mold can be attached to the injection molding machine relatively easily. However, there are problems. Specifically, there is a problem that the ease of work is not sufficient and the safety of the worker is not guaranteed. As already described, the ejector device is provided on the opposite side of the surface of the movable platen or fixed platen to which the mold is attached. That is, in the case of a toggle type mold clamping device, the ejector device is disposed on the side of the fixed plate or movable plate on which the toggle mechanism is provided. Since it is difficult to secure a sufficiently large work area on the side where such a toggle mechanism is provided, it is not easy to insert a tool such as an impact wrench. Since the work is performed manually, if the torque is excessive or insufficient, the connection between the rotating shaft and the ejector plate is loosened, and the screw thread is damaged. Furthermore, there is a risk of injury due to contact with the toggle mechanism, and the safety of workers is not guaranteed.

  An object of the present invention is to provide an ejector apparatus that solves the above-described problems. Specifically, an ejector plate with an ejector pin provided in a mold is connected to an ejector in the ejector apparatus. An object of the present invention is to provide an ejector device capable of easily and safely connecting rods.

  In order to achieve the above object, according to the present invention, in an ejector device provided on a mold platen, an ejector rod is composed of a cylindrical ejector rod body and a connecting pin penetrating the ejector rod in the axial direction. The connecting pin is formed with a male screw at the tip so that it can be screwed into the female screw of the mold side ejector plate provided in the mold. A sliding key having a predetermined length is formed at the rear end of the connecting pin, and a sprocket is engaged with the sliding key via a predetermined torque limiting mechanism. The torque limiting mechanism is a mechanism that transmits torque within the allowable torque, and prevents excessive torque. The connecting pin is urged in the axial direction by a spring and can slide within the range of the sliding key. The sprocket is driven by a motor via a chain or timing belt.

Thus, in order to achieve the above object, the invention according to claim 1 is provided by connecting to a mold side ejector plate with an ejector pin provided in a mold plate of the mold clamping device and provided in the mold. a ejector device including an ejector rod adapted to drive the ejector rod and the ejector rod body exhibits a cylindrical, rotatably and said ejector through said ejector rod body in the axial direction The connecting pin is configured to be movable in the axial direction by a predetermined length relative to the rod body, and the connecting pin is screwed into a female screw formed on the mold side ejector plate. rotated by a motor via a torque limiting mechanism with a male thread is formed at its distal end, and is spring biased to said mold side ejector plate direction The ejector rod is moved forward in the axial direction, whereby the ejector rod main body abuts on the mold side ejector plate, and the connecting pin has a tip portion of the mold side ejector plate. When the connecting pin is rotated in a state of contacting the female screw and retreating relative to the ejector rod body against the spring bias, and within the allowable torque allowed by the torque limiting mechanism. The ejector device is configured such that the ejector rod and the mold side ejector plate are coupled by the male screw being fastened to the female screw .
According to a second aspect of the present invention, in the ejector device according to the first aspect, the torque limiting mechanism is characterized in that an allowable torque in one rotation direction of the connecting pin is larger than an allowable torque in the opposite direction. It is configured as an ejector device.
According to a third aspect of the present invention, in the ejector device according to the first or second aspect, a limit switch is provided in the vicinity of the rear end portion of the connecting pin, and detects the sliding amount of the connecting pin in the axial direction. The connection state between the connection pin and the mold side ejector plate can be determined.
According to a fourth aspect of the present invention, the ejector device according to any one of the first to third aspects is provided in a mold clamping device of an injection molding machine and is driven by a command from a controller of the injection molding machine. It is comprised as an ejector apparatus characterized by this.

As described above, according to the present invention, an ejector is provided on a mold platen of a mold clamping device, and is connected to and driven by a mold side ejector plate with an ejector pin provided in the mold. An ejector device having a rod, the ejector rod having a tubular shape, a rod-shaped ejector rod main body, a shaft that penetrates the ejector rod main body in an axial direction and is rotatable relative to the ejector rod main body. The connecting pin is provided so as to be movable in the axial direction . The connecting pin is formed with a male screw that is screwed into a female screw formed on the mold side ejector plate at the tip. Therefore, when the male screw and the female screw are screwed together, the connecting pin and the mold side ejector plate can be coupled, and thereby the ejector rod and the mold side ejector plate can be coupled. And according to the present invention, the connecting pin is adapted to be rotated by a motor via a torque limiting mechanism together are spring biased to the mold side ejector plate direction. Further, according to the present invention, the ejector rod is advanced in the axial direction, whereby the ejector rod main body abuts on the mold side ejector plate, and the connecting pin abuts on the female screw of the mold side ejector plate. When the connecting pin is rotated relative to the ejector rod body against the spring bias, the male screw is tightened to the female screw within the allowable torque allowed by the torque limiting mechanism. The rod and the mold side ejector plate are connected. That is, according to the present invention, the ejector rod can be easily connected to the mold-side ejector plate, and it is ensured that the coupling force between the connecting pin and the mold-side ejector plate becomes a constant force. And since there is no need for human intervention in the connection, safety is also guaranteed. Further, if the motor is rotated in the reverse direction, the ejector rod can be easily and safely separated from the mold side ejector plate.

According to another invention, in the torque limiting mechanism, the allowable torque in one rotation direction of the connecting pin is larger than the allowable torque in the opposite direction. In this case, the male screw of the connecting pin can be tightened with a small allowable torque when the male screw of the mold side ejector plate is screwed and coupled, and the male screw can be loosened from the female screw with a large allowable torque when releasing the coupling. Then, even if the male screw and the female screw are engaged with each other with a strong force, the connection can be surely loosened and released. According to still another invention, a limit switch is provided in the vicinity of the rear end portion of the connecting pin so that the connecting state between the connecting pin and the mold side ejector plate can be determined by detecting the sliding amount of the connecting pin in the axial direction. It has become. Therefore, it is possible to easily determine whether or not the ejector rod and the mold side ejector plate are connected. According to another invention, since the ejector device is provided in the mold clamping device of the injection molding machine and is driven by a command from the controller of the injection molding machine, the operator only has to operate the controller, Installation work can be performed easily and safely.

It is side surface sectional drawing which shows the ejector apparatus which concerns on embodiment of this invention, the type | mold board | substrate with which this ejector apparatus is provided, and the metal mold | die provided in the type | mold board | substrate. It is a figure which shows the torque limiting mechanism provided in the ejector apparatus which concerns on embodiment of this invention, The (a) is side sectional drawing, The (a) is a front view of the components of a torque limiting mechanism, ) Is a cross-sectional view showing an enlarged part of a part. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the effect | action of the ejector apparatus which concerns on embodiment of this invention, (a) (b) is side sectional drawing which shows a part of ejector apparatus and a part of metal mold | die.

  Embodiments of the present invention will be described below. As shown in FIG. 1, the ejector device 1 according to the present embodiment is provided in a mold clamping device 2 of an electric injection molding machine. Although only a part of the mold clamping device 2 is shown in FIG. 1, the mold clamping device 2 includes a mold platen 5 to which a mold 4 is attached. In the present embodiment, the electric injection molding machine is a horizontal type, the mold platen 5 is a movable platen 5, and the mold 4 is a movable die 4. Therefore, when a toggle mechanism (not shown) is driven, the movable platen 5 is driven in the direction of the fixed platen, and the mold is opened and closed. The ejector device 1 according to the present embodiment is provided on the side of the movable platen 5 opposite to the mounting surface of the movable mold 4. That is, it is provided on the side where the toggle mechanism is provided.

  Similarly to the conventional ejector device, the ejector device 1 according to the present embodiment also has a back plate 7 as a back plate that supports the device, and a device-side ejector plate 8 provided between the back plate 7 and the movable platen 5. Etc. The back plate 7 is fixed to the movable platen 5 by guide shafts 9 and 9, and the apparatus-side ejector plate 8 is smoothly slid in the horizontal direction by inserting the guide shafts 9 and 9 into the guide holes 11 and 11, respectively. It has become so. The apparatus-side ejector plate 8 is driven in the horizontal direction by ball screw mechanisms 12 and 12. More specifically, the ball nuts 13 and 13 of the ball screw mechanisms 12 and 12 are fixed to the apparatus-side ejector plate 8, and the ball screws 14 and 14 are screwed to the ball nuts 13 and 13. Shaft portions 16 and 16 extending rearward of these ball screws 14 and 14 pass through holes formed in the back plate 7 and are rotatably supported on the back plate 7 by bearings. And the driven pulleys 18 and 18 of the front-end | tip of the axial parts 16 and 16 protruded on the opposite side of the back plate 7 are provided. An ejector servomotor 19 is fixed to the side of the movable platen 5, and a drive pulley 20 and driven pulleys 18, 18 provided on the ejector servomotor 19 are wound around a belt 22. Therefore, when the ejector servomotor 19 is driven, the device-side ejector plate 8 is driven by the ball screw mechanisms 12 and 12.

  The ejector device 1 according to the present embodiment is also provided with ejector rods 24, 24 on the device-side ejector plate 8. The structure of these ejector rods 24, 24 is the same as that of the conventional ejector rods 24, 24. Is different. That is, in the present embodiment, the ejector rods 24, 24 are composed of cylindrical ejector rod bodies 25, 25 having through holes in the axial direction and connecting pins 26, 26 inserted into the through holes. It is configured. Flange portions 28, 28 are formed at one end of the ejector rod main bodies 25, 25. The flange portions 28, 28 are fixed to the apparatus-side ejector plate 8 and are driven integrally with the apparatus-side ejector plate 8. It has come to be. On the other hand, the connecting pins 26, 26 pass through the apparatus-side ejector plate 8 and can be rotated within the ejector rod main bodies 25, 25. Disc-shaped stoppers 30 and 30 are fixed to the rear side of the connecting pins 26 and 26, and the stoppers 30 and 30 are placed in the bottomed holes 31 and 31 formed in the apparatus-side ejector plate 8. ing. The stoppers 30 and 30 are pressed by the springs 33 and 33 put in the holes 31 and 31. As a result, the connecting pins 26 and 26 are urged in the direction of the movable mold 4, and the movement in the direction of the movable mold 4 is restricted by the stoppers 30 and 30 by a predetermined length.

  Sliding keys 34 and 34 having a predetermined length are formed in the vicinity of the rear ends of the connecting pins 26 and 26. Then, the connecting pin side sprockets 37, 37 are engaged with the sliding keys 34, 34 via predetermined torque limiting mechanisms 36, 36. Although the torque limiting mechanisms 36 and 36 will be described in detail later, the torque can be transmitted within the allowable torque, and if an excessive torque exceeding this is applied, the torque limiting mechanism 36 is idled. Therefore, the connecting pins 26 and 26 can slide in the axial direction by the length of the sliding keys 34 and 34, and when the connecting pin side sprockets 37 and 37 rotate, the connecting pins 26 and 26 also rotate within the allowable torque. When a torque exceeding the allowable torque is applied, the connecting pin-side sprockets 37, 37 are idle with respect to the connecting pins 26, 26. Male screws 38, 38 are formed at the tips of the connecting pins 26, 26. As will be described later, the connecting pin side sprockets 37, 37 are rotated to be connected to the ejector plate 39 on the mold 4 side, The ejector rods 24, 24 can be connected to the ejector plate 39.

  A connecting motor 41 for driving the connecting pins 26 is fixed to the side of the movable platen 5, and a driving sprocket 42 is provided on the motor 41. The motor 41 is a geared motor in the present embodiment, but may be a servo motor. A through hole is formed in the back plate 7, and a predetermined spline shaft 43 is supported by the through hole and a bearing portion 44 formed in the movable platen 5. Although the spline shaft 43 is shown in FIG. 1 as being disposed at the approximate center of the back plate 7 or the movable platen 5, it may be disposed in the vicinity of the side portion. In general, since one ejector rod is often disposed at the center of the movable platen 5, the spline shaft 43 is disposed on the back plate 7 or on the side of the movable platen 5 so that the ejector rod is disposed on the side of the movable platen. It can be said that it does not interfere with the arrangement. A driven sprocket 45 is provided on a shaft provided so as to extend behind the spline shaft 43, and a chain 47 is wound around the drive sprocket 42. A spline nut 48 is engaged with the spline shaft 43 so as to be slidable in the axial direction, and a rotational force is transmitted. A nut-side sprocket 49 is fixed to the spline nut 48, and the nut-side sprocket 49 and the connecting pin-side sprockets 37, 37 are wound around by a chain 51. Therefore, when the connecting motor 41 is driven, the connecting pin side sprockets 37 and 37 can be rotated via the drive sprocket 42, the chain 47, the driven sprocket 45, the spline shaft 43, the nut side sprocket 49, and the chain 51.

  In the present embodiment, limit switches 52 and 52 are provided in the vicinity of the rear ends of the connecting pins 26 and 26. Whether or not the connecting pins 26 and 26 are driven in the axial direction can be detected by these limit switches 52 and 52, and whether or not the ejector rods 24 and 24 are connected to the ejector plate 39 on the mold 4 side. Can be judged. In addition, the ejector apparatus 1 which concerns on this Embodiment operate | moves by the command from the controller of an electric injection molding machine, and the signal from the limit switches 52 and 52 is also input into a controller. .

  The torque limiting mechanism 36 will be described. The torque limiting mechanism 36 includes a so-called torque guard, and as shown in FIG. 2A, a hub 61, a disk-shaped plate 62, a plurality of steel balls 63, 63,. It is composed of a sensor plate 64 that holds the plate 62 and disc springs 65, 65, and the connecting pin side sprocket 37 is also one of the components. The hub 61 includes a cylindrical portion 67 through which the connecting pin 26 is inserted, and a flange portion 68 formed integrally with the cylindrical portion 67. An axial groove that smoothly engages the sliding key 34 formed on the connecting pin 26 is formed on the inner peripheral surface of the cylindrical portion 67, and is slidable in the axial direction with respect to the connecting pin 26. Rotational force is transmitted without loss in the rotational direction. In the flange portion 68, recesses for storing a part of the steel balls 63, 63,..., That is, steel ball receiving seats 69, 69,. 2A shows the hub 61 viewed from the direction of the arrow Y0 in FIG. 2A. The steel ball seats 69, 69,... Are 2 in the radial direction of the flange portion 68. FIG. These are formed so as to be lined up, and five sets of them are equally arranged in the circumferential direction. That is, ten steel ball receiving seats 69, 69,... Are formed. The steel ball seats 69, 69,... Are depressions of a predetermined depth cut by machining, and the slopes formed by these depressions have different gradients depending on the circumferential direction. In FIG. 2C, one steel ball seat 69 is shown in cross section, but the slope α of the slope in the left rotation direction LH is larger than the slope β of the slope in the right rotation direction RH. Therefore, the steel balls 63, 63,... Stored in the steel ball receiving seats 69, 69,.

  .. Are formed in the connecting pin-side sprocket 37, and the steel balls 63, 63,... Are put in these storage pockets 71, 71,. I'm sitting on ... The disk-shaped plate 62 is rotatably provided on the sensor plate 64 via a bearing, and disc springs 65, 65,... Urge the sensor plate 64 toward the flange portion 68 of the hub 61. That is, the disk-shaped plate 62 is biased in the direction of the flange portion 68 by the disc springs 65, 65,. The steel balls 63, 63,... Are pressed against the steel ball receiving seats 69, 69,.

  When torque acts on the connecting pin-side sprocket 37, the torque limiting mechanism 36 is transmitted to the hub 61 via the steel balls 63, 63,... And can rotate the connecting pin 26. However, when the torque acting on the connecting pin-side sprocket 37 exceeds a predetermined allowable torque, the steel balls 63, 63,... Resist the biasing of the disc springs 65, 65,. Roll out from 69 ... Then, the connecting pin side sprocket 37 is idle with respect to the hub 61. As a result, it is possible to prevent excessive torque from acting on the connecting pin 26. In the torque limiting mechanism 36 according to the present embodiment, as described above, the steel balls 63, 63,... Housed in the steel ball receiving seats 69, 69,. It is relatively easy to appear in the right rotation direction RH. That is, when the rotational force of the connecting pin side sprocket 37 is transmitted to the hub 61, the allowable torque is large when the counterclockwise rotation direction is LH, and the allowable torque is small when the counterclockwise rotation direction is RH. In the present embodiment, the allowable torque in the left rotation direction LH is set to 166.6 N · m, and the allowable torque in the right rotation direction RH is set to 78.4 to 88.2 N · m. The left rotation direction LH is a direction in which the male screw 38 is loosened, and the right rotation direction RH is a direction in which the male screw 38 is tightened. That is, the torque limiting mechanism 36 according to the present embodiment can apply a stronger torque when loosening than the tightening of the male screw 38 of the connecting pin 26.

  The movable mold 4 connected by the ejector device 1 according to the present embodiment will be described. A recess 54 is formed in the parting surface P of the movable side mold 4, and a cavity for obtaining a molded product is formed when the mold is closed with respect to a fixed side mold (not shown). The inside of the movable side mold 4 is formed hollow, and is provided so that the mold side ejector plate 39 can be smoothly slid by being guided by the guide pins 55 and 55. Ejector pins 56, 56 are fixed to the mold side ejector plate 39, and the ejector pins 56, 56 can project a molded product from the recess 54. The heads of the ejector pins 56, 56 constitute a surface continuous with the recess 54 at a position where the mold side ejector plate 39 is retracted toward the movable platen 5 side. The mold-side ejector plate 39 is formed with a coupling hole to which the coupling pins 26 and 26 are coupled, and female screws 58 and 58 are formed in the hole.

  A method of attaching a mold to the mold clamping device 2 in the electric injection molding machine including the ejector device 1 according to the present embodiment will be described. By operating the controller, the ejector servo motor 19 is driven to retract the apparatus-side ejector plate 8 backward. That is, it is evacuated to the left in FIG. Then, the ejector rods 24 and 24 are retracted in the movable platen 5. The mold is attached to the mold clamping device 2 in a conventional manner. That is, the mold clamping device 2 is opened, the mold is suspended by a crane or the like and conveyed to the mold platen apparatus 2, and the locating ring of the mold is aligned so as to fit the center hole of the fixed platen. The movable platen 5 is moved forward to close the mold, and in this state, the fixed side die is fixed to the fixed platen and the movable side die 4 is fixed to the movable platen 5 by the die mounting bolts. The mold clamping device 2 is driven to open the mold.

  The ejector rods 24 and 24 of the ejector apparatus 1 according to the present embodiment and the mold side ejector plate 39 in the movable mold 4 are connected as follows. First, the ejector servomotor 19 is driven by operating the controller. Then, as shown in FIG. 3A, the apparatus-side ejector plate 8 moves forward as indicated by the arrow Y1, and the ejector rod 24 also moves forward. The distal end portion of the connecting pin 26 contacts the female screw 58 of the mold side ejector plate 39. Subsequently, the servo motor 19 for the ejector is driven and moved forward until the ejector rod 24 stops. Then, the connecting pin 26 moves backward as indicated by the arrow Y2, and the spring 33 is compressed by the stopper 30. It is detected in the limiter switch 52 that the connecting pin 26 has moved backward. In the movable mold 4, the mold ejector plate 39 is pushed in as indicated by an arrow Y 3. In FIG. 3A, the ejector rod main body 25 and the mold side ejector plate 39 are shown not contacting each other. However, when the ejector servo motor 19 is driven until the ejector rod 24 stops, these are shown. Will abut completely. When contacted, the ejector servomotor 19 is stopped.

  The coupling motor 41 is driven by a command from the controller. Then, as shown in FIG. 3A, the connecting pin side sprocket 37 and the connecting pin 26 rotate in the direction of the arrow Y4. The male screw 38 of the connecting pin 26 and the female screw 58 of the mold side ejector plate 39 are screwed together. Then, the connecting pin 26 moves forward as indicated by the arrow Y5. In the limit switch 52, it is detected that the connecting pin 26 has advanced. That is, it is detected that the connecting pin 26 and the male and female screws 38 and 58 of the mold ejector plate 39 are coupled. Subsequently, the connecting motor 41 is driven to completely connect the male and female screws 38 and 58. When fully coupled, the torque acting on the connecting pin 26 is high. When a predetermined allowable torque is exceeded, the connecting pin-side sprocket 37 is rotated with respect to the connecting pin 26 by the action of the torque limiting mechanism 36 to protect the male and female screws 38 and 58. The coupling motor 41 is stopped by a command from the controller. The connection between the ejector rods 24 and 24 of the ejector apparatus 1 according to the present embodiment and the mold-side ejector plate 39 in the movable mold 4 is completed.

  A molded product can be molded in an electric injection molding machine as is conventionally known. That is, the mold is clamped in the mold clamping device 2, the molten resin is injected into the cavity in the mold, and the mold is opened after cooling and solidification. Then, the ejector servo motor 19 is driven to eject the molded product. Thereafter, the same molding is performed.

  As can be easily understood by those skilled in the art, when removing the mold from the mold clamping device 2, the mold is removed in the reverse order of the method of attaching the mold described above. That is, the mold is opened in the mold clamping device 2. The connecting motor 41 is driven by a command from the controller. Then, the connection between the male screw 38 of the connecting pin 26 and the female screw 58 of the mold side ejector plate 39 can be disconnected. At this time, as described above, since the torque limiting mechanism 36 has a large allowable torque in the direction in which the male screw 58 is loosened, the coupling between the connecting pin 26 and the mold-side ejector plate 39 can be reliably disconnected. The ejector servo motor 19 is driven by a command from the controller to retract the ejector rods 24 and 24 in the movable platen 5. As is conventionally known, the mold is removed from the mold clamping device 2 by, for example, removing a mounting bolt.

  The ejector apparatus according to the present embodiment can be variously modified. For example, it can be provided in a hydraulic injection molding machine instead of an electric injection molding machine. In the present embodiment, the torque limiting mechanism is configured by a predetermined torque guard made of a hub, a steel ball, or the like provided with a steel ball receiving seat of a predetermined shape. It can also be implemented by a mechanism. For example, the connecting pin-side sprocket may be sandwiched by a predetermined spring-biased friction plate, and a conventional torque limiter that transmits torque by the friction force of the friction plate may be used. The chain can also be modified. In the present embodiment, the chain is described as being hung around each sprocket, but this can be replaced with a timing belt. Furthermore, although it has been described that the drive of the connecting pin in the axial direction is detected by the limit switch, it may be detected by another sensor such as an optical sensor. In the present embodiment, the in-mold ejector plate 39 in the movable mold 4 is not provided with a spring. However, for example, a movable mold in which a spring is provided on the ejector pin 56 may be employed. . In such a movable mold, the in-mold ejector plate 39 is urged by the spring in the backward direction, that is, in the direction of the movable platen 5, but the same as the movable mold 4 provided with no spring. The ejector rods 24, 24 can be connected by the ejector device according to the embodiment.

DESCRIPTION OF SYMBOLS 1 Ejector apparatus 2 Mold clamping apparatus 4 Movable side mold 5 Movable platen 7 Back plate 8 Apparatus side ejector plate 12 Ball screw mechanism 13 Ball nut 14 Ball screw 18 Driven pulley 19 Ejector servo motor 20 Drive pulley 22 Belt 24 Ejector rod 25 Ejector rod Main body 26 Connecting pin 30 Stopper 31 Hole 33 Spring 34 Sliding key 36 Torque limiting mechanism 37 Connecting pin side sprocket 38 Male screw 39 Mold side ejector plate 41 Connecting motor 42 Drive sprocket 43 Spline shaft 45 Driven sprocket 47 Chain 48 Spline nut 49 Nut side sprocket 51 Chain 52 Limit switch 56 Ejector pin 58 Female thread 61 Hub 62 Disk-shaped plate 63 Steel ball 65 Sensor play 69 steel ball receiving seat

Claims (4)

An ejector device comprising an ejector rod provided on a mold plate of a mold clamping device and connected to a die side ejector plate with an ejector pin provided in the die to drive the plate. ,
The ejector rod has a cylindrical ejector rod main body, and is capable of rotating through the ejector rod main body in the axial direction and movable in the axial direction by a predetermined length relative to the ejector rod main body. It is composed of connecting pins provided,
The connecting pin, a male screw to be screwed into the female screw formed on the mold side ejector plate is formed at its distal end, the mold side ejector plate direction to the torque limiting mechanism with which spring biased It is designed to be rotated by a motor via
The ejector rod is advanced in the axial direction, whereby the ejector rod main body abuts on the mold side ejector plate, and the connecting pin abuts on the female screw of the mold side ejector plate and When the connecting pin is rotated relative to the ejector rod body against a spring bias, and the connecting pin is rotated in this state, the male screw is within the allowable torque allowed by the torque limiting mechanism. The ejector device is characterized in that the ejector rod and the mold side ejector plate are coupled to each other by being fastened to the ejector. 2. The ejector device according to claim 1, wherein the torque limiting mechanism has an allowable torque in one rotation direction of the connecting pin larger than an allowable torque in the opposite direction. 3. The ejector device according to claim 1, wherein a limit switch is provided in the vicinity of a rear end portion of the connection pin, and an amount of sliding of the connection pin in an axial direction is detected, and the connection pin and the mold side ejector are detected. An ejector device characterized in that the connection state of plates can be determined.   The ejector apparatus according to any one of claims 1 to 3, wherein the ejector apparatus is provided in a mold clamping device of an injection molding machine and is driven by a command from a controller of the injection molding machine.

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