A friction welding fixture

Abstract

The present invention discloses a clamp for friction welding, comprising a circular ring base, a clamp tube composed of three or more clamp petals with spacing between the petals, and an elastic expansion tube; the mounting holes at the thin cylindrical surface of the clamp tube are connected to the positioning protrusions of the base, and the inner end wall of the base is connected to the step between the thin and thick cylindrical surfaces; a hard material elastic pad is padded between the boss protruding from the outer end wall of the elastic expansion tube and the thin cylindrical end wall of the clamp tube, and the outer end is fixed by an elastic retaining ring that is clamped in the ring groove of the inner wall of the base, and there is a gap between the inner end and the inner step on the inner wall of the thick outer cylindrical surface of the clamp tube, and the position of the larger diameter of the inner wall is interference fit with the inner cylindrical surface of the large inner diameter of the clamp tube, and the position of the smaller diameter of the inner wall is clearance fit with the inner cylindrical surface of the large inner diameter of the clamp tube. The present invention has high local strength, simple force-bearing structure, no mutual involvement between the petals, space for thermal expansion and contraction, long service life, and low cost.

Description

Technical Field

[0001] The invention relates to a fixture for friction welding. Background Art

[0002] Friction welding is mainly used for processing two types of products: hollow shafts and long-handled sleeves.

[0003] The existing friction welding fixture is an integrated four-petal fixture, which is used in conjunction with the spindle taper sleeve, spindle flange and return spring. The integrated four-petal fixture has a uniform wall thickness. The thin wall causes high friction welding heat. The overall connection part of the fixture has no space for thermal expansion and contraction at high temperatures. When clamping the shaft head, the thin-walled connection position with high force is easily damaged and has a short lifespan.

[0004] The existing one-piece four-petal fixture has a complex force direction, and the petals are entangled with each other. When the spindle taper sleeve is pushed tight, only two or three petals may be stressed, resulting in poor coaxiality between the two blanks between the shaft head and the cavity during processing, poor runout of the final product, and black skin is prone to appear during subsequent grinding. During use, the welding position may be more stressed and prone to breakage. If one petal is damaged, it must be replaced as a whole, which is very costly. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a friction welding fixture with high local strength, simple force-bearing structure, no entanglement between the petals, space for thermal expansion and contraction, long service life and low cost.

[0006] To achieve the above object, the technical solution of the present invention is: a friction welding fixture, comprising a circular ring base, a clamping tube composed of three or more clamping petals with spacing between the petals, and an elastic expansion tube;

[0007] The inner end of the inner wall of the base has evenly arranged positioning protrusions with the same number as the clamping petals, and the outer end has an annular groove; the outer end of the outer wall of the base has an outer positioning circle with a large diameter, and the outer positioning circle matches the inner diameter of the circular hole of the spindle taper sleeve used in conjunction;

[0008] The outer wall of each clamping petal has three steps, which divide the clamping tube into a thin cylindrical surface with a small diameter at the inner end, a thicker cylindrical surface with a large diameter in the middle, and a thick outer cylindrical surface at the outer end, the minimum diameter of which is the diameter of the thicker cylindrical surface; the mouth of the thick outer cylindrical surface has a circle of annular groove, the outer diameter of which matches the inner diameter of the spindle flange used in conjunction; the outer wall of the thin cylindrical surface matches the inner wall of the base, and a mounting hole matching each positioning protrusion of the base is opened on the thin cylindrical surface of each clamping petal of the clamping tube; there is an inner step on the inner wall of the thick outer cylindrical surface, which divides the entire inner wall of the clamping tube into an inner cylindrical surface with a large inner diameter and an inner cylindrical surface with a small inner diameter, and the cylindrical surface with a small inner diameter matches the outer circle of the workpiece shaft head;

[0009] The mounting holes at the thin cylindrical surface of the clamp tube are snap-fitted onto the positioning protrusions of the base, and the inner end wall of the base is connected to the step between the thin and thick cylindrical surfaces; the outer end wall of the elastic expansion tube protrudes out with a boss whose outer circle matches the inner wall of the base, and its outer wall is a truncated cone with a micro-cone, and the outer end diameter of the boss is smaller than the inner end diameter, and it is placed in each clamp petal and the inner cavity of the base, and a hard material elastic pad is padded between the boss and the thin cylindrical end wall of the clamp tube, and its outer end is fixed by an elastic retaining ring snap-fitted into the annular groove of the inner wall of the base, and there is a gap between its inner end and the inner step on the inner wall of the thick outer truncated cone of the clamp tube, and the position of the larger diameter of the inner wall has an interference fit with the inner cylindrical surface of the large inner diameter of the clamp tube, and the position of the smaller diameter of the inner wall has a clearance fit with the inner cylindrical surface of the large inner diameter of the clamp tube.

[0010] Preferably, the clamp tube has an expansion joint at the center of the thin cylindrical end of each clamp petal, which penetrates the mounting hole thereon, so as to avoid stress fatigue and easy fracture of the thin wall when the clamp is clamped, and further extend the service life of the clamp.

[0011] Further preferably, the elastic expansion tube is a thin truncated cone with a taper of 0.4±0.1°, and the thin truncated cone is separated by expansion joints with inner ends connected and outer ends separated, and inner ends separated and outer ends connected. The elastic expansion tube of this structure is both strong and elastic.

[0012] Further preferably, the elastic expansion tube is made of 65Mn steel.

[0013] Further preferably, the hard material elastic pad is a nylon elastic pad, which has both hardness and elasticity.

[0014] When in use, the present invention is used in conjunction with a spindle taper sleeve, a spindle flange and a return spring. The annular groove of the thick outer cylindrical table mouth of the fixture is clamped in the inner hole of the spindle flange, and the outer positioning circle of the base is clamped in the circular hole of the spindle taper sleeve; after the present invention is retracted, the workpiece is connected, and the workpiece is plugged into the small inner diameter inner cylindrical surface of the clamping flap of the fixture. After the present invention is pushed out, the workpiece is clamped in the small inner diameter inner cylindrical surface of the clamping flap. The clamping petals of the present invention are not integrated and are not subjected to stress as a whole. Only one petal is subjected to stress, and the stress-bearing structure is simple. The petals are not entangled with each other and have a long service life. There is a space for accommodating thermal expansion and contraction between the petals, and the life will not be affected by deformation or damage caused by high-temperature stress and extrusion. The petals are of a stepped structure, and the thickness is large at the position where the deformation is large. The outer end has the thickest outer circular table surface, followed by the thicker cylindrical surface in the middle, and the innermost end has the smallest deformation and is a thin cylindrical surface. This not only makes the structural design relatively simple and increases the service life, but also reduces the use of materials and has a relatively low manufacturing cost. Moreover, all four petals can bear stress, and after processing, the coaxiality between the workpiece shaft head and the cavity is good, the run-out value is reduced, the workpiece is not easy to break at the welding position, and has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a schematic diagram of the three-dimensional structure of the present invention;

[0016] Figure 2 A top view of the present invention;

[0017] Figure 3 for Figure 2 AA section view;

[0018] Figure 4 It is a schematic diagram of the three-dimensional structure of the base in the present invention;

[0019] Figure 5 It is a schematic diagram of the three-dimensional structure of the clip petal in the present invention;

[0020] Figure 6 It is a schematic diagram of the three-dimensional structure of the elastic expansion tube in the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with specific embodiments.

[0022] like Figures 1 to 6 As shown, this embodiment includes a circular ring base 3, a clamping tube 4 composed of four (three, five, etc., four is optimal) or more clamping petals 5 with a spacing between each clamping petal 5, and an elastic expansion tube 1.

[0023] The inner end of the inner wall of the base 3 has four evenly arranged positioning protrusions 9, and the outer end has an annular groove 10. The outer end of the outer wall of the base 3 has an outer positioning circle 16 with a large diameter, which matches the inner diameter of the circular hole of the spindle taper sleeve used in conjunction.

[0024] The outer wall of each clamping petal 5 has three steps to divide the clamping tube into a thin cylindrical surface 53 with a small diameter at the inner end, a thick cylindrical surface 52 with a large diameter in the middle, and a thick outer cylindrical surface 51 with a minimum diameter equal to the diameter of the thick cylindrical surface at the outer end. The mouth of the thick outer cylindrical surface 51 has a circle of annular groove 6, and the outer diameter of the annular groove 6 matches the inner diameter of the spindle flange used in conjunction. The outer wall of the thin cylindrical surface 53 matches the inner wall of the base 3, and a mounting hole 12 matching the base positioning protrusion 9 is opened on the thin cylindrical surface 53 of each clamping petal of the clamping tube. There is an inner step 13 on the inner wall of the thick outer cylindrical surface 51, which divides the inner wall of the entire clamping tube 4 into a large inner diameter inner cylindrical surface 17 and a small inner diameter inner cylindrical surface 18, and the small inner diameter cylindrical surface 18 matches the outer circle of the workpiece shaft head. Preferably, the clamping tube has an expansion joint 11 at the center of the end of the thin cylindrical surface 53 at the inner end of each clamping petal 5, which penetrates the mounting hole 12 thereon.

[0025] The mounting holes 12 at the thin cylindrical surface of the clamp tube 4 are snap-fitted onto the positioning protrusions 9 of the base 3 , and the inner end wall of the base 3 is connected to the step between the thin and thick cylindrical surfaces 53 and 52 . The outer end wall of the elastic expansion tube 1 has a boss 7 whose outer circle matches the inner wall of the base 3. The outer wall is a truncated cone with a slight cone. The outer end diameter of the boss 7 is smaller than the inner end diameter. The boss 7 is placed in the inner cavity of each clamping petal 5 of the clamping tube 4 and the base 3. A hard material elastic pad 8 is padded between the boss 7 and the end wall of the thin cylindrical surface 53 of the clamping tube 4. The outer end of the elastic expansion tube 1 is fixed in the gear position by an elastic retaining ring 2 (the elastic retaining ring 2 in this embodiment is a C-shaped retaining spring) clamped in the annular groove 10 of the inner wall of the base 3. There is a gap between the inner end and the inner step 13 on the inner wall of the thick outer circumferential table 51 of the clamping tube. The position of the larger diameter of the inner wall has an interference fit with the inner cylindrical surface 17 of the larger inner diameter of the clamping tube 4, and the position of the smaller diameter of the inner wall has a clearance fit with the inner cylindrical surface 17 of the larger inner diameter of the clamping tube 4. Preferably, the elastic expansion tube 1 is a thin truncated cone with a taper of 0.4±0.1°, and the thin truncated cone is separated by expansion joints 14 and 15, which are connected at the inner end and separated at the outer end, and separated at the inner end and connected at the outer end. Preferably, the elastic expansion tube 1 is made of 65Mn steel. Preferably, the hard material elastic pad 8 is a nylon elastic pad.

[0026] The above-described embodiments are only preferred and exemplary and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fixture for friction welding, Features: It includes a circular ring base, a clamping tube composed of three or more clamping petals with spacing between the clamping petals, and an elastic expansion tube; The inner end of the inner wall of the base has evenly arranged positioning protrusions with the same number as the clamping petals, and the outer end has an annular groove; the outer end of the outer wall of the base has an outer positioning circle with a large diameter, and the outer positioning circle matches the inner diameter of the circular hole of the spindle taper sleeve used in conjunction; The outer wall of each clamping petal has three steps, which divide the clamping tube into a thin cylindrical surface with a small diameter at the inner end, a thicker cylindrical surface with a large diameter in the middle, and a thick outer cylindrical surface at the outer end, the minimum diameter of which is the diameter of the thicker cylindrical surface; the mouth of the thick outer cylindrical surface has a circle of annular groove, the outer diameter of which matches the inner diameter of the spindle flange used in conjunction; the outer wall of the thin cylindrical surface matches the inner wall of the base, and a mounting hole matching each positioning protrusion of the base is opened on the thin cylindrical surface of each clamping petal of the clamping tube; there is an inner step on the inner wall of the thick outer cylindrical surface, which divides the entire inner wall of the clamping tube into an inner cylindrical surface with a large inner diameter and an inner cylindrical surface with a small inner diameter, and the cylindrical surface with a small inner diameter matches the outer circle of the workpiece shaft head; The mounting holes at the thin cylindrical surface of the clamp tube are snap-fitted onto the positioning protrusions of the base, and the inner end wall of the base is connected to the step between the thin and thick cylindrical surfaces; the outer end wall of the elastic expansion tube protrudes out with a boss whose outer circle matches the inner wall of the base, and its outer wall is a truncated cone with a micro-cone, and the outer end diameter of the boss is smaller than the inner end diameter, and it is placed in each clamp petal and the inner cavity of the base, and a hard material elastic pad is padded between the boss and the thin cylindrical end wall of the clamp tube, and its outer end is fixed by an elastic retaining ring snap-fitted into the annular groove of the inner wall of the base, and there is a gap between its inner end and the inner step on the inner wall of the thick outer truncated cone of the clamp tube, and the position of the larger diameter of the inner wall has an interference fit with the inner cylindrical surface of the large inner diameter of the clamp tube, and the position of the smaller diameter of the inner wall has a clearance fit with the inner cylindrical surface of the large inner diameter of the clamp tube.

2. The friction welding fixture according to claim 1, Features: The elastic expansion tube is in the shape of a thin truncated cone, the taper of the thin truncated cone is 0.4±0.1°, and the thin truncated cone is separated by expansion joints with the inner ends connected and the outer ends separated, and the inner ends separated and the outer ends connected.

3. The friction welding fixture according to claim 2, Features: The elastic expansion tube is made of 65Mn steel.

4. The friction welding fixture according to claim 1, 2 or 3, Features: The clamping tube has an expansion joint at the center of the thin cylindrical end of each clamping petal, which penetrates the mounting hole thereon.

5. The friction welding fixture according to claim 4, Features: The hard material elastic pad is a nylon elastic pad.

6. The friction welding fixture according to claim 1, 2 or 3, Features: The hard material elastic pad is a nylon elastic pad.

Images