Steering shaft inner supporting tool

Abstract

The utility model discloses a steering shaft inner supporting tool and a steering shaft clamping machining method, and belongs to the technical field of tool clamps. The steering shaft inner supporting tool comprises a flange plate, a clamping core rod, a double-end connecting thread sleeve and a conical pull rod which are coaxially arranged, the double-end connecting thread sleeve is axially and movably arranged in a center hole of the flange plate, and the front end of the clamping core rod extends into the center hole of the flange plate to be in threaded connection with the flange plate. The front end of the conical pull rod penetrates through an inner hole of the clamping core rod and is in threaded connection with the double-end connecting thread sleeve; the outer conical surface of the rear end of the conical pull rod abuts against the inner conical surface of the conical hole in the rear end of the clamping core rod. The outer cylindrical surface of the rear end of the clamping core rod is used for sleeving a steering shaft, and at least one tensioning groove is radially formed in the outer cylindrical surface in a penetrating mode. When the inner supporting tool is used for clamping the steering shaft, the contact area of the steering shaft and the tool is large, clamping is stable, the steering shaft is completely exposed out of the tool, one-time forming of the outer surface of the steering shaft and a shaft hole is facilitated, and therefore the form and location tolerance of machined parts is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of tooling fixtures, in particular to a steering shaft inner support tooling. Background Art

[0002] The steering shaft is a force transmission shaft that transmits the steering control mechanism torque acting on the steering wheel to the steering gear. It is an important component of the steering mechanism and requires high processing accuracy. The yacht steering shaft is generally made of aluminum alloy. The aluminum alloy blank is first obtained by extrusion molding, and the aluminum alloy blank is finely processed to form the steering shaft. Since there are many grooves on the surface of the aluminum alloy blank, when the existing external clamp is used to clamp the part, the contact area between the clamp and the part is small, and it is easy to clamp it off. In addition, when clamping, the part is difficult to position, and the shape and position tolerance of the part after processing cannot be guaranteed. Summary of the invention

[0003] In order to solve the above problems, the utility model provides a steering shaft inner support tooling.

[0004] The technical solution adopted by the utility model is:

[0005] A steering shaft inner support tooling comprises a coaxially arranged flange, a clamping mandrel, a double-headed connecting nut and a tapered pull rod. The double-headed connecting nut is axially movably arranged in the center hole of the flange. The front end of the clamping mandrel extends into the center hole of the flange and is threadedly connected to the flange. The front end of the tapered pull rod passes through the inner hole of the clamping mandrel and is threadedly connected to the double-headed connecting nut. The outer conical surface at the rear end of the tapered pull rod abuts against the inner conical surface of the first conical hole at the rear end of the clamping mandrel. The outer cylindrical surface at the rear end of the clamping mandrel is used to fit onto the steering shaft, and at least one tensioning groove is radially penetrated on the outer cylindrical surface.

[0006] Furthermore, a conical positioning surface is provided at the front end of the clamping mandrel, and a second conical hole is provided at the rear end of the flange, and the conical positioning surface abuts against the inner conical surface of the second conical hole. With this technical solution, when the conical pull rod is pulled, the front end of the clamping mandrel abuts against the flange, so that the clamping mandrel can be radially deformed under the clamping action of the flange and the conical pull rod, which is conducive to the opening of the tensioning groove.

[0007] Furthermore, a steering shaft positioning surface is provided on the front side of the outer cylindrical surface of the clamping mandrel, and when clamping, the front end surface of the steering shaft abuts against the steering shaft positioning surface, so as to prevent the steering shaft from moving in series during machining, unify the reference surface, ensure the stability of the machining dimensions, and help improve the machining accuracy of the steering shaft.

[0008] Furthermore, the clamping mandrel is in a stepped cylindrical shape as a whole, including a threaded connection part, a conical positioning part, a cylindrical positioning part and a cylindrical sleeve part connected in sequence, the conical positioning part is connected to the cylindrical positioning part through a U-shaped annular groove, the outer circumferential surface of the front end of the conical positioning part is formed as a conical positioning surface, and the step surface connecting the cylindrical positioning part and the cylindrical sleeve part is formed as a steering shaft positioning surface, and four tensioning grooves are provided on the cylindrical positioning part and the cylindrical sleeve part, and the four tensioning grooves are evenly distributed in the circumferential direction, and the rear end thereof extends to the rear end surface of the cylindrical sleeve part, and the front end thereof extends to the U-shaped annular groove. The adoption of this technical solution is conducive to the expansion and contraction deformation of the tensioning groove, and makes the clamping mandrel evenly stressed.

[0009] Furthermore, a first circular positioning hole is provided in the U-shaped annular groove, and the first circular positioning hole corresponds to the tensioning groove one by one and is connected. The provision of the circular positioning hole can not only prevent stress concentration and overcutting when the slow wire cuts the four tensioning grooves, but also facilitate the expansion and contraction deformation of the four tensioning grooves.

[0010] Furthermore, the inner hole of the clamping mandrel includes a large cylindrical hole located at the center of the threaded connection part and the conical positioning part and a small cylindrical hole located at the center of the cylindrical positioning part and the cylindrical sleeve part. The clamping mandrel is divided into a part with a tensioning groove and a part without a tensioning groove through the connecting surface of the large cylindrical hole and the small cylindrical hole, which is beneficial to the expansion and contraction deformation of the tensioning groove and increases the strength and rigidity of the mandrel.

[0011] Furthermore, the outer circumferential surface of the rear end of the conical positioning part is provided with a second circular positioning hole for inserting the force rod. During assembly, the force rod is inserted into the circular positioning hole and the clamping mandrel is screwed to tighten the connection between the clamping mandrel and the flange.

[0012] Furthermore, the center hole of the flange is a stepped through hole, which is composed of a first circular hole, a second circular hole, a third circular hole and a second conical hole connected in sequence from front to back; the diameters of the first circular hole, the second circular hole and the third circular hole decrease in sequence, and the inner wall of the third circular hole is provided with an internal thread for connecting a clamping core rod; further, the double-headed connecting screw sleeve is in a stepped cylindrical shape, including a large cylindrical section and a small cylindrical section; the outer diameter of the large cylindrical section is adapted to the diameter of the second circular hole of the flange, and the outer diameter of the small cylindrical section is adapted to the diameter of the third circular hole of the flange.

[0013] The diameter of the first circular hole is larger than the outer diameter of the large cylindrical section of the double-ended connecting screw sleeve, so that an operating space can be formed in the first circular hole, which is beneficial to the threaded connection between the double-ended connecting screw sleeve and the tensioning mechanism of the machine tool.

[0014] Furthermore, the center of the large cylindrical section is provided with a large end threaded hole for connecting the tensioning mechanism of the machine tool, and the center of the small cylindrical section is provided with a small end threaded hole for connecting the tapered pull rod, and the small end threaded hole is connected with the large end threaded hole. The threaded connection facilitates the fastening connection between the tooling and the machine tool.

[0015] Furthermore, the tapered pull rod is cylindrical in shape as a whole, and its front end is provided with an external thread connected to the double-headed connecting screw sleeve, and its rear end outer circumferential surface radially protrudes outward to form an external conical surface adapted to the conical hole of the clamping mandrel; a hexagonal positioning hole is also provided in the center of the rear end surface of the tapered pull rod. The hexagonal positioning hole is provided to facilitate tightening the tapered pull rod with a wrench during assembly.

[0016] Beneficial effects of the utility model:

[0017] 1. When the inner support fixture of the utility model is used to clamp the steering shaft, the steering shaft is completely exposed outside the fixture, which is convenient for one-time molding of the outer surface of the steering shaft and the shaft hole, thereby improving the shape and position tolerance of the processed parts.

[0018] 2. The steering shaft is clamped by internal support, and the clamping mandrel cooperates with the steering shaft hole, which is convenient for part positioning. The contact area between the fixture and the part is large, and there will be no clamping deviation, which improves the clamping efficiency and stability, and further ensures the shape and position tolerance of the processed parts.

[0019] 3. By using the inner support tooling of the utility model, the outer surface and the shaft hole of the steering shaft can be processed at one time, thereby ensuring the shape and position tolerances of the processed parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural diagram of the steering shaft inner support tooling of the utility model.

[0021] Figure 2 This is a flange structure diagram of the utility model.

[0022] Figure 3 It is a structural diagram of a double-ended connecting screw sleeve of the utility model.

[0023] Figure 4 This is a structural diagram of the clamping mandrel of the utility model.

[0024] Figure 5 This is a structural diagram of a tapered pull rod of the utility model. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings and a preferred implementation manner. Example

[0026] See also Figure 1-Figure 5 This embodiment provides a steering shaft inner support tool, including a flange 10, a clamping core rod 20, a double-headed connecting nut 30 and a tapered pull rod 40.

[0027] In this embodiment, the flange 10 is a neck flange, including a flange portion and a neck portion, the flange portion is provided with a flange hole 100, the center portion of the flange portion and the neck portion is provided with a center hole, the center hole is a stepped through hole, and the stepped through hole is composed of a first circular hole 101, a second circular hole 102, a third circular hole 103 and a second conical hole 104 connected in sequence from front to back; the diameters of the first circular hole 101, the second circular hole 102 and the third circular hole 103 decrease in sequence, the inner wall of the third circular hole 103 is provided with an internal thread, and the small end diameter of the second conical hole 104 is equal to the diameter of the third circular hole 103. In this embodiment, the cone angle of the second conical hole 104 is 30°. The flange hole 100 of the flange 10 is used to connect the main shaft of the machine tool. A section of knurled surface 11 is provided on the outer circumferential surface of the neck of the flange 10 to facilitate the threaded connection of the flange 10 with the double-headed connecting screw sleeve 30.

[0028] The double-ended connecting screw sleeve 30 is in a stepped cylindrical shape, including a large cylindrical section 31 and a small cylindrical section 32; the outer diameter of the large cylindrical section 31 is adapted to the diameter of the second circular hole 102 of the flange 10, and the outer diameter of the small cylindrical section 32 is adapted to the diameter of the third circular hole 103. The diameter of the second circular hole 102 is adapted to the outer diameter of the large cylindrical section of the double-ended connecting screw sleeve 30, which is conducive to the coaxial arrangement of the double-ended connecting screw sleeve 30 and the flange 10. The diameter of the first circular hole 101 is much larger than the outer diameter of the large cylindrical section of the double-ended connecting screw sleeve 30, and an operating space can be formed in the first circular hole 101, which is conducive to the threaded connection of the double-ended connecting screw sleeve 30 with the tensioning mechanism of the machine tool. The central part of the large cylindrical section is provided with a large end threaded hole 301 for connecting the tensioning mechanism of the machine tool, and the central part of the small cylindrical section is provided with a small end threaded hole 302 for connecting the tapered pull rod 40. The small-end threaded hole 302 is connected to the large-end threaded hole 301 , which is beneficial for the concentric arrangement of the two threaded holes.

[0029] The clamping mandrel 20 is in the shape of a stepped cylinder as a whole, and includes a threaded connection part 25, a conical positioning part 24, a cylindrical positioning part 23 and a cylindrical sleeve part 22 connected in sequence, and the conical positioning part 24 is connected to the cylindrical positioning part 23 through a U-shaped annular groove; the threaded connection part 25 is provided with an external thread adapted to the third circular hole 103 of the flange, and the conical positioning part 24 is provided with a conical positioning surface 241 adapted to the second conical hole 104 of the flange and four second circular positioning holes 202, and the second circular positioning holes 202 are located at the rear side of the conical positioning surface 241, and the threaded connection between the clamping mandrel 20 and the flange 10 is tightened by inserting a force rod into the second circular positioning hole 202. The diameter of the cylindrical positioning part 23 is larger than that of the cylindrical sleeve part 22, and the outer diameter of the cylindrical sleeve part 22 is adapted to the inner diameter of the steering shaft. The outer circumferential surface of the cylindrical sleeve portion 22 is the outer cylindrical surface 221 for sleeve steering shaft, and the step surface connecting the cylindrical positioning portion 23 and the cylindrical sleeve portion 22 is the steering shaft positioning surface 231. When clamping, the front end surface of the steering shaft abuts against the steering shaft positioning surface 231. The length of the cylindrical sleeve portion 22 is adapted to the length of the steering shaft. The inner hole 201 passes through the threaded connection portion 25, the conical positioning portion 24, the cylindrical positioning portion 23 and the cylindrical sleeve portion 22. The inner hole 201 includes a large cylindrical hole located at the center of the threaded connection portion 25 and the conical positioning portion 24, and a small cylindrical hole located at the center of the cylindrical positioning portion 23 and the cylindrical sleeve portion 22. The inner circumferential surface of the small cylindrical hole located at the end of the cylindrical sleeve portion 22 protrudes radially outward to form a first conical hole 21 with a conical angle of 30°; the first conical hole 21 is used to accommodate the conical positioning portion of the tapered tie rod 40. In this embodiment, four tensioning grooves 222 are radially opened on the cylindrical positioning portion 23 and the cylindrical sleeve portion 22. The four tensioning grooves 222 are evenly distributed along the circumferential direction, and their rear ends extend to the rear end surface of the cylindrical sleeve portion 22, and their front ends extend to the U-shaped annular groove, and a first circular positioning hole 203 is arranged in the U-shaped annular groove. The arrangement of the first circular positioning hole 203 can not only prevent stress concentration and overcutting when the four tensioning grooves are cut by slow wire, but also facilitate the expansion and contraction deformation of the four tensioning grooves.

[0030] The tapered rod 40 is cylindrical in shape as a whole, and its front end is provided with an external thread 42 adapted to the small end threaded hole 302 of the double-ended connecting screw sleeve 30, and its rear end outer circumferential surface protrudes radially outward to form an external conical surface 411 adapted to the first conical hole 21 of the clamping mandrel 20. A hexagonal positioning hole 43 is also provided in the center of the rear end surface of the tapered rod 40, and the tapered rod 40 is threadedly connected to the double-ended connecting screw sleeve 30 by inserting a hexagonal handle into the hexagonal positioning hole 43.

[0031] The flange 10, the clamping mandrel 20, the double-headed connecting screw sleeve 30 and the tapered pull rod 40 are all made of SUJ-2 material, and after processing, they are heat treated to make their hardness reach HRC45-48; the four tensioning groove rods 212 of the clamping mandrel 20 need to be cut with slow wire to ensure that their width is within the range of 0.3-0.4mm.

[0032] After the parts are processed, they are assembled:

[0033] First, the front end of the clamping mandrel 20 is inserted into the center hole of the flange, so that the threaded connection portion 25 of the clamping mandrel 20 is threadedly connected with the third circular hole 103 of the flange 10, and a force rod is inserted into the second circular positioning hole 202 of the clamping mandrel 20 and tightened, so that the conical positioning surface 241 of the front end of the clamping mandrel 20 abuts against the inner conical surface of the second conical hole 104 of the flange 10;

[0034] Then, the double-ended connecting screw sleeve 30 is arranged in the central hole of the flange 10, so that the large cylindrical section of the double-ended connecting screw sleeve 30 is located in the first circular hole 101 and the second circular hole 102 of the flange, and the small cylindrical section of the double-ended connecting screw sleeve 30 extends into the third circular hole 103 of the flange;

[0035] Finally, the front end of the tapered pull rod 40 passes through the inner hole 201 of the clamping core rod 20 and is threadedly connected to the small end threaded hole 302 of the double-headed connecting nut 30, and the outer conical surface 411 of the rear end of the tapered pull rod 40 abuts against the inner conical surface 223 of the first conical hole 21 at the rear end of the clamping core rod 20.

[0036] The method of using the above-mentioned steering shaft inner support tooling is as follows:

[0037] 1) First, the assembled inner support fixture is fastened to the machine tool spindle through the flange 10, and the concentricity of the inner support fixture and the machine tool spindle is guaranteed to be within 0.02mm;

[0038] 2) Then, the steering shaft 5 is sleeved onto the outer cylindrical surface 221 of the clamping mandrel 20, and the front end surface of the product steering shaft is against the positioning surface 231 of the clamping mandrel 20;

[0039] 3) Then, the large end threaded hole 301 of the double-ended connecting screw sleeve 20 is threadedly connected to the tensioning mechanism of the machine tool;

[0040] 4) The tensioning mechanism of the machine tool pulls the double-headed connecting screw sleeve 30 to move forward linearly, and the double-headed connecting screw sleeve 30 drives the conical pull rod 40 to squeeze the clamping mandrel 20, and the openings of the four tensioning grooves 222 of the clamping mandrel 20 become larger, tightening the steering shaft;

[0041] 5) Then the outer circumferential surface of the steering shaft and one end of the shaft hole are processed at one time to ensure the shape and position tolerance of the outer circumferential surface of the steering shaft and the shaft hole.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications are also within the protection scope of the present invention.

Claims

1. A steering shaft inner support tooling, characterized in that: The invention comprises a coaxially arranged flange (10), a clamping mandrel (20), a double-headed connecting nut (30) and a tapered pull rod (40); the double-headed connecting nut (30) is axially movably arranged in the center hole of the flange (10); the front end of the clamping mandrel (20) extends into the center hole of the flange (10) and is threadedly connected to the flange; the front end of the tapered pull rod (40) passes through the inner hole of the clamping mandrel (20) and is threadedly connected to the double-headed connecting nut (30); the outer conical surface (411) at the rear end of the tapered pull rod (40) abuts against the inner conical surface of the first conical hole (21) at the rear end of the clamping mandrel (20); the outer cylindrical surface (221) at the rear end of the clamping mandrel (20) is used to fit the steering shaft, and at least one tensioning groove (222) is radially penetrated on the outer cylindrical surface (221).

2. A steering shaft inner support tooling according to claim 1, characterized in that: A conical positioning surface (241) is provided at the front end of the clamping mandrel (20), and a second conical hole (104) is provided at the rear end of the flange (10), wherein the conical positioning surface (241) abuts against an inner conical surface of the second conical hole (104).

3. A steering shaft inner support tooling according to claim 2, characterized in that: A steering shaft positioning surface (231) is provided on the front side of the outer cylindrical surface (221) of the clamping mandrel (20); during clamping, the front end surface of the steering shaft abuts against the steering shaft positioning surface (231).

4. A steering shaft inner support tooling according to claim 3, characterized in that: The clamping mandrel (20) is in the shape of a stepped cylinder as a whole, and comprises a threaded connection portion (25), a conical positioning portion (24), a cylindrical positioning portion (23) and a cylindrical sleeve portion (22) which are connected in sequence. The conical positioning portion (24) is connected to the cylindrical positioning portion (23) via a U-shaped annular groove. The outer circumferential surface of the front end of the conical positioning portion (24) forms a conical positioning surface (241). The step surface connecting the cylindrical positioning portion (23) and the cylindrical sleeve portion (22) forms a steering shaft positioning surface (231). Four tensioning grooves (222) are provided on the cylindrical positioning portion (23) and the cylindrical sleeve portion (22). The four tensioning grooves (222) are evenly distributed in the circumferential direction, and their rear ends extend to the rear end surface of the cylindrical sleeve portion (22), and their front ends extend to the U-shaped annular groove.

5. The steering shaft inner support tooling according to claim 4, characterized in that: A first circular positioning hole (203) is provided in the U-shaped annular groove, and the first circular positioning hole (203) corresponds to the tensioning groove (222) one by one and is in communication with each other.

6. A steering shaft inner support tooling according to claim 5, characterized in that: The inner hole (201) of the clamping mandrel (20) comprises a large cylindrical hole located at the center of the threaded connection part (25) and the conical positioning part (24), and a small cylindrical hole located at the center of the cylindrical positioning part (23) and the cylindrical sleeve part (22).

7. The steering shaft inner support tooling according to claim 4, characterized in that: The outer circumferential surface of the rear end of the conical positioning portion (24) is provided with a second circular positioning hole (202) for inserting the force adding rod.

8. The steering shaft inner support tooling according to claim 7, characterized in that: The center hole of the flange (10) is a stepped through hole, which is composed of a first circular hole (101), a second circular hole (102), a third circular hole (103) and a second conical hole (104) which are connected in sequence from front to back; the diameters of the first circular hole (101), the second circular hole (102) and the third circular hole (103) are successively reduced, and the inner wall of the third circular hole (103) is provided with an internal thread for connecting a clamping mandrel (20); the double-headed connecting screw sleeve (30) is in a stepped cylindrical shape, comprising a large cylindrical section (31) and a small cylindrical section (32); the outer diameter of the large cylindrical section (31) is adapted to the diameter of the second circular hole (102) of the flange, and the outer diameter of the small cylindrical section (32) is adapted to the diameter of the third circular hole (103) of the flange.

9. The steering shaft inner support tooling according to claim 1, characterized in that: The tapered pull rod (40) is cylindrical in shape as a whole, and its front end is provided with an external thread (42) connected to the double-headed connecting screw sleeve (30), and its rear end outer circumferential surface protrudes radially outward to form an external conical surface (411) adapted to the conical hole (21) of the clamping core rod (20); the central portion of the rear end surface of the tapered pull rod (40) is also provided with a hexagonal positioning hole (43).

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