Injection apparatus

• US 20030054059A1
• Filed: 09/06/2002
• Published: 03/20/2003
• Est. Priority Date: 09/14/2001
• Status: Active Grant

• Current Assignee: Sumitomo Heavy Industries Limited
• Original Assignee: Sumitomo Heavy Industries Limited
• Inventors: Nishio, Okito
• Granted Patent: US 6,755,636 B2
• Time in Patent Office: Days
• US Class Current: 425/3
• CPC Class Codes: B29C 2045/5024 screws rotated by the coaxial rotor of an electric motor
• CPC Class Codes: B29C 2045/5032 using means for detecting injection or back pressures
• CPC Class Codes: B29C 2045/504 electric motors for rotary and axial movement of the screw being coaxial with the screw
• CPC Class Codes: B29C 2045/5056 screws axially driven by a rotatable screw shaft cooperating with a fixed nut
• CPC Class Codes: B29C 45/5008 Drive means therefor
• CPC Class Codes: B29C 45/83 Lubricating means

Abstract

An injection apparatus includes an injection frame; a cylinder member attached to the injection frame; an injection member disposed within the cylinder member such that the same can rotate and can advance and retreat; a rotary slide member attached to the injection member; a stator attached to the injection frame, and a rotor disposed radially inward of the stator to be rotatable relative to the stator. The rotor includes a hollow, cylindrical member disposed radially outward of the rotary slide member and movably relative to the rotary slide member, and a magnet attached to the cylindrical member. In this case, the rotor has a cylindrical member and a magnet and can transmit generated rotation directly to the rotary slide member. Therefore, a transmission mechanism which consists of an output gear, a counter drive gear, a counter driven gear, a rotary member, etc. becomes unnecessary; and generation of noise due to meshing engagement of gears and other components can be prevented. Accordingly, the number of components can be reduced, generation of torque loss can be prevented, and cost of the injection apparatus can be reduced.

Claims

1. An injection apparatus, comprising:

(a) an injection frame;

(b) a cylinder member attached to the injection frame;

(c) an injection member disposed within the cylinder member such that the same can rotate and can advance and retreat;

(d) a rotary slide member attached to the injection member; and

(e) a stator attached to the injection frame, and a rotor disposed radially inward of the stator to be rotatable relative to the stator;

(f) the rotor comprising a hollow, cylindrical member disposed radially outward of the rotary slide member and movably relative to the rotary slide member, and a magnet attached to the cylindrical member.

2. An injection apparatus as described in claim 1, further comprising a casing formed integrally with the injection frame.

3. An injection apparatus as described in claim 1, wherein the stator and the rotor constitute a first drive section for rotating the rotary slide member in a metering process.

4. An injection apparatus as described in claim 1, wherein the stator and the rotor constitute a second drive section for axially moving the rotary slide member in an injection process.

5. An injection apparatus as described in claim 1, further comprising a direction-of-motion changing section for converting a rotary motion generated at the rotor to a rectilinear motion and for transmitting the rectilinear motion to the rotary slide member.

6. An injection apparatus as described in claim 1, wherein

(a) the direction-of-motion changing section comprises a first conversion element and a second conversion element;

and

(b) the first conversion element is supported rotatably relative to the rotary slide member.

7. An injection apparatus, comprising:

(a) an injection frame;

(b) a cylinder member attached to the injection frame;

(c) an injection member disposed within the cylinder member such that the same can rotate and can advance and retreat;

(d) a rotary slide member attached to the injection member;

(e) a stator attached to the injection frame, and a rotor supported radially inward of the stator to be rotatable relative to the stator; and

(f) a rotational-speed detecting section for detecting a rotational speed of the rotor;

(g) the rotational-speed detecting section comprising an element to be detected, the element being attached to a hollow, cylindrical member to be rotated upon rotation of the rotor, and a detecting element disposed in opposition to the element to be detected.

8. An injection apparatus as described in claim 7, wherein recesses and projections are formed on a detection surface of the element to be detected.

9. An injection apparatus as described in claim 7, wherein a magnetized detection surface is formed on the element to be detected.

10. An injection apparatus as described in claim 7, wherein the element to be detected is disposed to face the detecting element in a non-contacting state.

11. An injection apparatus as described in claim 7, wherein the cylindrical member is disposed radially outward of the rotary slide member and movably relative to the rotary slide member.

12. An injection apparatus as described in claim 7, wherein the rotor includes the cylindrical member, and a magnet attached to the cylindrical member.

13. An injection apparatus as described in claim 7, wherein the rotational-speed detecting section detects pole position of the rotor.

14. An injection apparatus, comprising:

(a) a frame;

(b) a stator attached to the frame to be located radially inward of the frame;

(c) a rotor disposed radially inward of the stator; and

(d) a rotary slide member disposed radially inward of the rotor, the rotary slide member being reciprocated along an axial direction, wherein

(e) at a rotation transmission section formed on a side face of the rotor, axial movement of the rotary slide member is permitted, and rotation of the rotary slide member is restricted.

15. An injection apparatus as described in claim 14, wherein a lubricant chamber is formed between the rotary slide member and a cylindrical member which constitutes the rotor.

16. An injection apparatus as described in claim 14, wherein a seal member is disposed on an outer circumference of the rotary slide member in such a manner that the seal member is in contact with an inner circumferential surface of a cylindrical member which constitutes the rotor.

17. An injection apparatus wherein

(a) an airtight first lubricant chamber is formed between a frame and a rotor;

and

(b) the first lubricant chamber is connected to a second lubricant chamber formed inside the rotor in order to supply lubricant to the second lubricant chamber.

18. An injection apparatus as described in claim 17, wherein the first lubricant chamber is formed through disposition of a seal member between the frame and a rotation transmission section.