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CN-116745094-B - Injection device

CN116745094BCN 116745094 BCN116745094 BCN 116745094BCN-116745094-B

Abstract

The screw (12) of the injection device (10) according to one embodiment has a plurality of outer circumferential protrusions (50), and an outer circumferential protrusion inclined surface (50S) and a second outer circumferential protrusion inclined surface (50 SS) are formed on each of the plurality of outer circumferential protrusions (50). The hub (14) of the injection device (10) has a plurality of inner circumferential protrusions (60), and an inner circumferential protrusion slope (60S) and a second inner circumferential protrusion slope (60 SS) are formed on each of the plurality of inner circumferential protrusions (60). There is no flat surface at the rear end of each of the plurality of outer circumferential protrusions (50) and the front end of each of the plurality of inner circumferential protrusions (60).

Inventors

  • OSAWA TAKUYA
  • Kokeguchi Shotaro

Assignees

  • 发那科株式会社

Dates

Publication Date
20260508
Application Date
20220120
Priority Date
20210129

Claims (5)

  1. 1. An injection device (10) comprising a screw (12) disposed along a front-rear direction, the front-rear direction being a front direction in which an injection resin is injected and a rear direction opposite to the front direction, and a bush (14) formed so as to be capable of spline-fitting with the screw, The screw has a plurality of peripheral protrusions (50) formed on the peripheral surface of the rear end side of the screw and extending in the front-rear direction at intervals in the circumferential direction of the screw, The plurality of outer circumferential protrusions are respectively formed with outer circumferential protrusion inclined surfaces (50S) inclined so as to be smaller toward the rear end of the outer circumferential protrusion and outer circumferential protrusion width (50W) along the circumferential direction of the screw, second outer circumferential protrusion inclined surfaces (50 SS) inclined so as to be smaller toward the rear end of the outer circumferential protrusion, The bushing has a through hole (14H) extending in the front-rear direction, a plurality of inner circumferential protrusions (60) formed on the inner circumferential surface of the through hole and extending in the front-rear direction at intervals in the circumferential direction of the through hole, An inner peripheral projection inclined surface (60S) inclined so as to be smaller toward the tip of the inner peripheral projection and smaller in the inner peripheral projection width (60W) along the circumferential direction of the through hole, and a second inner peripheral projection inclined surface (60 SS) inclined so as to be larger toward the tip of the inner peripheral projection, The rear ends of the outer circumferential projections are free from the flat surfaces and the sides formed by the outer circumferential projections, the front ends of the inner circumferential projections are free from the flat surfaces and the sides formed by the inner circumferential projections, The rear end of the second outer peripheral protrusion slope reaches the position of the rear end of the outer peripheral protrusion slope, and the front end of the second inner peripheral protrusion slope reaches the position of the front end of the inner peripheral protrusion slope.
  2. 2. The injection device of claim 1, wherein the injection device comprises a housing, The peripheral protrusion inclined surface is formed on one of both circumferential side surfaces (50F 1, 50F 2) of the screw on the rear end side of each of the plurality of peripheral protrusions, The inner peripheral protrusion inclined surface is formed on one of circumferential side surfaces (60F 1, 60F 2) of the through hole on the tip end side of each of the plurality of inner peripheral protrusions.
  3. 3. The injection device of claim 1, wherein the injection device comprises a housing, The peripheral protrusion inclined surface is formed on each of both circumferential side surfaces of the screw in respective rear end sides of the plurality of peripheral protrusions, The inner peripheral protrusion inclined surface is formed on each of both circumferential side surfaces of the through hole in the tip end side of each of the plurality of inner peripheral protrusions.
  4. 4. The injection device according to any one of claim 1 to 3, wherein, The bushing is provided with a convex part (14A) protruding from the rear end surface of the bushing, The injection device has: A bush fastening part (16) having a recess (16A) for receiving the protruding part and fixing the bush for receiving the protruding part in the recess, and A cylinder (20) for accommodating the screw, When the height (50H) of the second outer peripheral protrusion inclined surface is Cs1, the height (60H) of the second inner peripheral protrusion inclined surface is Cb1, a gap (GP 1) between the outer peripheral protrusion and the cylinder when the screw fitted to the bushing is accommodated in the cylinder is Ls1, and a gap (GP 2) between the outer periphery of the convex portion and the inner periphery of the concave portion when the bushing is fixed to the bushing fastening portion is Lb1, The relationship of Cs1+ Cb1> ls1+ Lb1 holds.
  5. 5. The injection device according to any one of claim 1 to 3, wherein, The injection device has: a linear motor (24) that advances and retreats the bushing with respect to the screw in the front-rear direction; a detection unit (38) for detecting the linear motion torque of the linear motion motor, and And a motor control unit (28) that controls the linear motor so that the bush advances from a position away from the screw, and stops the bush when the linear torque exceeds a linear torque threshold.

Description

Injection device Technical Field The present invention relates to injection devices. Background Japanese patent application laid-open publication No. 2019-055488 discloses a motor control unit for controlling a motor for direct motion and a motor for rotational motion. The linear motion motor is a motor that moves the bushing in the axial direction of the screw. The motor for rotational movement is a motor that rotates the bushing around the shaft of the screw. The motor control unit controls the linear motion motor to advance the bushing from a state separated from the screw in a direction approaching the screw. When the torque of the linear motor is equal to or greater than the first torque during the advancement of the bushing, the motor control unit controls the rotary motor to rotate the bushing. Disclosure of Invention However, in order to improve the working efficiency of spline fitting, it is required that spline fitting is performed only by advancing the bushing relative to the screw without rotating the bushing. Accordingly, the present invention provides an injection device capable of improving the working efficiency of spline fitting. The invention provides an injection device, comprising a screw arranged along a front-back direction, wherein the front-back direction refers to a front direction of injection resin and a back direction opposite to the front direction, a bushing capable of being jogged with a screw spline, wherein, The screw has a plurality of outer circumferential projections formed on the outer circumferential surface of the rear end side of the screw and extending in the front-rear direction at intervals in the circumferential direction of the screw, The plurality of outer circumferential protrusions are respectively formed with outer circumferential protrusion inclined surfaces which incline so as to be smaller in width along the circumferential direction of the screw as they go toward the rear end of the outer circumferential protrusion, second outer circumferential protrusion inclined surfaces which incline so as to be smaller in diameter as they go toward the rear end of the outer circumferential protrusion, The bushing has a through hole extending in the front-rear direction, a plurality of inner circumferential protrusions formed on the inner circumferential surface of the through hole and extending along the front-rear direction at intervals in the circumferential direction of the through hole, The inner circumferential protrusions are each formed with an inner circumferential protrusion slope inclined so as to be smaller in width toward the tip of the inner circumferential protrusion and along the circumferential direction of the through hole, a second inner circumferential protrusion slope inclined so as to be larger in diameter toward the tip of the inner circumferential protrusion, There is no plane at the rear end of each of the plurality of outer circumferential protrusions and the front end of each of the plurality of inner circumferential protrusions. According to the aspect of the present invention, spline fitting can be performed by the advancing operation of the bushing with respect to the screw without rotating the bushing. As a result, the working efficiency of spline fitting can be improved. Drawings Fig. 1 is a schematic view showing an injection device according to an embodiment. Fig. 2 is a view showing a screw and a bushing. Fig. 3A is a view showing a cross section of the screw of fig. 2, and fig. 3B is a view showing a cross section of the bushing of fig. 2. Fig. 4 is a flowchart showing a control process performed by the motor control unit to spline-fit the screw to the bush. Fig. 5 is a diagram showing a screw and a bushing according to modification 1. Detailed Description Hereinafter, the present invention will be described in detail with reference to the drawings, by referring to preferred embodiments. Embodiment(s) Fig. 1 is a schematic view showing an injection device 10 according to an embodiment. The injection device 10 injects a resin for molding a mold. In the present embodiment, the injection direction of the injection molding resin is set to the front direction, and the opposite direction to the injection direction is set to the rear direction. The injection device 10 has a screw 12, a hub 14, a hub securing portion 16, and a drive mechanism 18. The screw 12 is accommodated in the through hole 20H of the cylinder 20. The screw 12 rotates to convey the molding resin charged into the through hole 20H in the forward direction. A nozzle 22 is provided at the tip of the cylinder 20, and the molding resin fed by the screw 12 is ejected from the nozzle 22. The screw 12 has a screw portion 12A and a spline portion 12B. The screw portion 12A is a front portion of the screw 12. A spiral protrusion 12P is formed on the outer peripheral surface of the screw portion 12A. The spline portion 12B is a rear portion of the screw 12, and is connected to a rea