Thin-wall bent pipe turning clamp

Abstract

The utility model discloses a thin-wall bent pipe turning clamp, and belongs to the technical field of lathe clamps. The clamp comprises a positioning shaft and a tensioning assembly, the end face of one end of the positioning shaft is an inclined face, the included angle between the inclined face and a plane perpendicular to the central axis of the positioning shaft is alpha, and the tensioning assembly and the positioning shaft are coaxially arranged and detachably connected. The positioning shaft is clamped and fixed on a three-jaw chuck of a lathe, the tensioning assembly is located on the inner side of the thin-wall bent pipe, the thin-wall bent pipe is locked and fixed to the inclined face of the positioning shaft after the thin-wall bent pipe is tensioned by the tensioning assembly, the two ends of the thin-wall bent pipe are effectively fixed, and the clamping stability is good; and the tensioning assembly cannot shield the end face of the to-be-machined end of the thin-wall bent pipe, and the to-be-machined end of the thin-wall bent pipe can be machined conveniently.

Description

Technical Field

[0001] The utility model relates to a thin-walled bent pipe turning fixture, belonging to the technical field of lathe fixtures. Background Art

[0002] In the field of aerospace engines, various types of metal elbow fittings have been widely used. They are mainly used in some transition connection positions, which have high requirements for the connection sealing of the products, so high processing accuracy is required to ensure the connection sealing of the products. Figure 1 As shown, the bending angle is greater than 90°, and the angle between the end faces is α. The thin-walled bent pipe needs to be clamped and fixed to the lathe spindle by a fixture, and then the end faces and the outer cylindrical surfaces at both ends are machined.

[0003] The Chinese patent document with the publication number CN218776111U discloses a fixture for turning the outer circle of an elbow joint, including a positioning shaft, a pressure block and a tensioning assembly, wherein the positioning shaft is coaxially provided with a through groove, and one end of the positioning shaft is evenly provided with a plurality of tightening slits, the pressure block is located on the inner side of the through groove and close to the end of the positioning shaft provided with the tightening slit, and the tensioning assembly passes through the pressure block and the positioning shaft, and can connect the pressure block and the positioning shaft together. The positioning shaft and the pressure block are pulled against each other by the tensioning assembly, and since the end of the positioning shaft is synchronously opened outward when the tensioning assembly pulls against the positioning shaft and the pressure block, the elbow joint can be positioned and clamped, and the positioning and clamping accuracy is high, ensuring that the center line of the end to be processed of the elbow joint coincides with the center line of the positioning shaft and the center line of the lathe spindle, ensuring that the wall thickness of the step hole is uniform after processing, and further ensuring the product quality of the elbow joint.

[0004] However, after the thin-walled elbow is clamped and fixed to the lathe spindle by the elbow joint external turning fixture, the end face of the thin-walled elbow to be processed is blocked by the tightening section and cannot be processed, and the elbow joint external turning fixture only clamps and fixes one end of the thin-walled elbow, and the clamping stability of the thin-walled elbow needs to be further improved. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a thin-walled pipe bending turning fixture.

[0006] The utility model is realized through the following technical solutions:

[0007] A thin-walled pipe bending lathe processing fixture comprises a positioning shaft and a tensioning assembly. One end face of the positioning shaft is an inclined surface, and the angle between the inclined surface and a plane perpendicular to the central axis of the positioning shaft is α. The tensioning assembly is coaxially arranged with the positioning shaft and detachably connected to the positioning shaft.

[0008] The positioning shaft comprises a clamping section and a positioning section, the positioning section is coaxially arranged with the clamping section, one end of the positioning section is connected with one end of the clamping section, and the inclined surface is located on the end of the positioning section away from the clamping section.

[0009] The diameter of the positioning section is greater than the diameter of the clamping section.

[0010] A square hole and a threaded hole are axially arranged on the positioning shaft at the center of the circle, one end of the threaded hole is connected with one end of the square hole, and the threaded hole is arranged away from the inclined surface.

[0011] The tensioning assembly comprises a tensioning sleeve and a screw. The screw is located on the inner side of the tensioning sleeve and locks and fixes the tensioning sleeve onto the positioning shaft.

[0012] A through hole is coaxially formed on the tension sleeve, and a plurality of notches are evenly distributed on one end of the tension sleeve away from the positioning shaft, and the notches are communicated with the through hole.

[0013] One end of the tension sleeve close to the positioning shaft is square.

[0014] The utility model also comprises a padding ring, which is in an outer circle and inner square structure, and is movably sleeved on the tension sleeve, with one end of the padding ring abutting against the shaft shoulder of the tension sleeve and the other end abutting against the inclined surface.

[0015] The beneficial effects of the utility model are as follows: the positioning shaft is clamped and fixed on the three-jaw chuck of the lathe, the tensioning assembly is located on the inner side of the thin-walled bent pipe, and after the tensioning assembly tightens the thin-walled bent pipe, the thin-walled bent pipe is locked and fixed to the inclined surface of the positioning shaft, both ends of the thin-walled bent pipe are effectively fixed, the clamping stability is good, and the tensioning assembly will not block the end face of the end to be processed on the thin-walled bent pipe, so that the end to be processed of the thin-walled bent pipe can be processed easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the thin-walled elbow of the utility model;

[0017] Figure 2 This is a schematic diagram of the structure of the utility model when clamping and fixing a thin-walled elbow and processing the first end thereof;

[0018] Figure 3 The utility model is a structural schematic diagram of clamping and fixing a thin-walled bent pipe and processing the second end thereof.

[0019] In the figure: 1-thin-wall bent pipe, 2-positioning shaft, 20-square hole, 21-threaded hole, 22-inclined surface, 3-washer ring, 4-tension sleeve, 40-through hole, 41-slot, 5-screw. DETAILED DESCRIPTION

[0020] The technical solution of the utility model is further described below, but the scope of protection required is not limited to the description.

[0021] like Figures 1 to 3 As shown, the thin-walled pipe bending machining fixture described in the utility model comprises a positioning shaft 2 and a tensioning assembly, wherein one end face of the positioning shaft 2 is an inclined surface 22, and the angle between the inclined surface 22 and the plane perpendicular to the central axis of the positioning shaft 2 is α, and the tensioning assembly is coaxially arranged with the positioning shaft 2 and detachably connected with the positioning shaft 2. When in use, the positioning shaft 2 is clamped and fixed on the three-jaw chuck of the lathe, and the tensioning assembly is located on the inner side of the thin-walled pipe bending 1. After the tensioning assembly tightens the thin-walled pipe bending 1, the thin-walled pipe bending 1 is locked and fixed to the inclined surface 22 of the positioning shaft 2. Both ends of the thin-walled pipe bending 1 are effectively fixed, the clamping stability is good, and the tensioning assembly will not block the end face of the end to be processed on the thin-walled pipe bending 1, so it is convenient to process the end to be processed of the thin-walled pipe bending 1.

[0022] The positioning shaft 2 includes a clamping section and a positioning section. The positioning section is coaxially arranged with the clamping section, and one end of the positioning section is connected to one end of the clamping section. The inclined surface 22 is located on the end of the positioning section away from the clamping section.

[0023] The diameter of the positioning section is larger than that of the clamping section. A shaft shoulder is formed at the connection between the positioning section and the clamping section. The clamping section is used to clamp the three-jaw chuck on the lathe and cooperates with the shaft shoulder to realize the positioning of the whole set of fixtures on the lathe.

[0024] The positioning shaft 2 is provided with a square hole 20 and a threaded hole 21 along the axial direction at the center of the circle, one end of the threaded hole 21 is connected to one end of the square hole 20, and the threaded hole 21 is arranged away from the inclined surface 22. When in use, the square hole 20 is used to position the tension sleeve 4 and stop the tension sleeve 4 from rotating relative to the positioning shaft 2; the threaded hole 21 is used to be threadedly connected with the screw 5.

[0025] The tensioning assembly includes a tensioning sleeve 4 and a screw 5 . The screw 5 is located inside the tensioning sleeve 4 and locks and fixes the tensioning sleeve 4 onto the positioning shaft 2 .

[0026] The tension sleeve 4 is coaxially provided with a through hole 40 , and one end of the tension sleeve 4 away from the positioning shaft 2 is evenly provided with a plurality of notches 41 , and the notches 41 are communicated with the through hole 40 .

[0027] The end of the tension sleeve 4 close to the positioning shaft 2 is square. Figure 2 and Figure 3 As shown, the outer contour of the cross section of the lower part of the tension sleeve 4 is square, and the inner contour of the cross section is circular, that is, the lower part of the tension sleeve 4 is a square outer and circular inner structure.

[0028] The utility model also includes a padding ring 3, which is in an outer circle and inner square structure. The padding ring 3 is movably mounted on the tension sleeve 4, with one end of the padding ring abutting against the shoulder of the tension sleeve 4 and the other end abutting against the inclined surface 22. When in use, the angle between the end faces of the padding ring 3 and the plane perpendicular to its own central axis is α. The function of the padding ring 3 is to pad the height of the tension sleeve 4 so that the tension sleeve 4 can play a tensioning and positioning role on the thin-walled elbow 1 at a farther position.

[0029] The working principle or use process of the thin-walled pipe bending turning fixture described in the utility model is as follows:

[0030] 1. Position the first end of the thin-walled elbow 1 with the rough material end face

[0031] First, place the washer 3, tensioner sleeve 4, and screw 5 as Figure 2 As shown, the thin-walled elbow 1 is assembled on the positioning shaft 2. At this time, the screw 5 is not tightened. Then, any end of the unprocessed thin-walled elbow 1 is inserted into the tension sleeve 4, and one end face of the thin-walled elbow 1 is made to be close to the inclined surface 22 on the positioning shaft 2 as much as possible. Then, the screw 5 is tightened. As the screw 5 is screwed in, the tension sleeve 4 will undergo elastic deformation, thereby tightening the thin-walled elbow 1. At this time, the outer circle of the tension sleeve 4 will also generate a component force, so that one end face of the thin-walled elbow 1 is closer to the inclined surface 22. At this moment, the positioning and clamping of the thin-walled elbow 1 on the fixture is completed. Since the tensioning assembly is coaxially arranged with the positioning shaft 2, and the angle between the inclined surface 22 and the plane perpendicular to the central axis of the positioning shaft 2 is α, the end to be processed (i.e., the first end) of the thin-walled elbow 1 is coaxial with the positioning shaft 2. Then, the fixture with the thin-walled elbow 1 installed is positioned and clamped on the three-jaw chuck of the lathe. In order to ensure the machining allowance of the second end of the thin-walled elbow 1 and reduce the measurement workload, the first end face of the thin-walled elbow 1 is only machined to see the light, and the outer circle of the end of the thin-walled elbow 1 is machined according to the design drawing to complete the first end machining.

[0032] 2. Position the second end of the thin-walled elbow 1 with the precision-machined end surface

[0033] like Figure 3 As shown, after the first end of the thin-walled elbow 1 is processed, the spacer ring 3 in the fixture is removed, and then the thin-walled elbow 1 is turned around and clamped to the fixture. Next, the circumferential runout is measured by a meter and qualified, and then the second end of the thin-walled elbow 1 can be processed.

[0034] The thin-walled pipe bending turning fixture provided in this application has the following beneficial effects:

[0035] 1. The positioning range is large and accurate: Since the tension sleeve 4 can be elastically deformed within a certain range, that is, the outer circle can be freely changed, even if the inner hole tolerance is large, it can be freely tightened to achieve positioning.

[0036] 2. The springback deformation of the thin-walled elbow 1 is reduced after processing: Because the thin-walled elbow 1 will be accurately positioned and fixed on the fixture before processing, the inner hole of the end to be processed of the thin-walled elbow 1 will be tightened and positioned by the tightening sleeve 4. Therefore, during the processing, even if there is a certain cutting force on the wall of the thin-walled elbow 1, it will not cause the thin-walled elbow 1 to be squeezed and cause elastic deformation.

[0037] 3. Reduce measurement and accurate positioning: When clamping and processing the first end of the thin-walled elbow 1, this fixture does not need to measure the angle and length of the thin-walled elbow 1. It only needs to adjust the tension sleeve 4 and the positioning shaft 2 to be concentric with the main shaft to process the size specified in the design drawing. When processing the second end, the end face that has been processed at the first end can be used for positioning.

Claims

1. A thin-walled pipe bending turning fixture, characterized in that: The invention comprises a positioning shaft (2) and a tensioning assembly, wherein one end face of the positioning shaft (2) is an inclined surface (22), and the angle between the inclined surface (22) and a plane perpendicular to the central axis of the positioning shaft (2) is α; the tensioning assembly is coaxially arranged with the positioning shaft (2) and is detachably connected to the positioning shaft (2).

2. The thin-walled pipe bending turning fixture according to claim 1, characterized in that: The positioning shaft (2) comprises a clamping section and a positioning section, the positioning section and the clamping section are coaxially arranged, one end of the positioning section is connected to one end of the clamping section, and the inclined surface (22) is located on the end of the positioning section away from the clamping section.

3. The thin-walled pipe bending turning fixture according to claim 2, characterized in that: The diameter of the positioning section is greater than the diameter of the clamping section.

4. The thin-walled pipe bending turning fixture according to claim 1, characterized in that: The positioning shaft (2) is provided with a square hole (20) and a threaded hole (21) along the axial direction at the center of the circle, one end of the threaded hole (21) is connected to one end of the square hole (20), and the threaded hole (21) is arranged away from the inclined surface (22).

5. The thin-walled pipe bending turning fixture according to claim 1, characterized in that: The tensioning assembly comprises a tensioning sleeve (4) and a screw (5); the screw (5) is located on the inner side of the tensioning sleeve (4) and locks and fixes the tensioning sleeve (4) onto the positioning shaft (2).

6. The thin-walled pipe bending turning fixture according to claim 5, characterized in that: A through hole (40) is coaxially provided on the tension sleeve (4), and a plurality of notches (41) are evenly distributed on one end of the tension sleeve (4) away from the positioning shaft (2), and the notches (41) are communicated with the through hole (40).

7. The thin-walled pipe bending turning fixture according to claim 5, characterized in that: One end of the tension sleeve (4) close to the positioning shaft (2) is square.

8. The thin-walled pipe bending turning fixture according to claim 5, characterized in that: The utility model also comprises a padding ring (3) which is in the form of an outer circle and an inner square. The padding ring (3) is movably sleeved on the tension sleeve (4), one end of which abuts against the shaft shoulder of the tension sleeve (4) and the other end abuts against the inclined surface (22).

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