Clamping fixture for boring center hole in splined hub

Abstract

The splined hub center hole boring clamping fixture comprises a base, a supporting plate vertically arranged on the base and a pneumatic clamping finger arranged on the supporting plate and used for clamping a splined hub, the pneumatic clamping finger is provided with two pneumatic fingers, arc-shaped grooves are formed in the opposite faces of the two pneumatic fingers, and a positioning seat is arranged at the upper end of the base; a positioning spearhead used for being clamped into an inner nest hole of the splined hub is arranged on the positioning seat in an up-down sliding mode, a counter bore is formed in the bottom of the positioning seat, a baffle ring arranged on the positioning spearhead in a sleeving mode is arranged in the counter bore in the axial direction of the counter bore in a sliding mode, and a spring is arranged between the baffle ring and the positioning seat. Double-arc-shaped groove positioning is adopted, center positioning is accurate, and the coaxiality of the center hole and the splined hub after boring is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of boring technology in machining, and in particular to a clamping fixture for boring the center hole of an automotive drive shaft spline hub. Background Technology

[0002] The splined hub is an important component in a non-constant velocity automotive driveshaft assembly, such as... Figure 6 As shown, the splined hub 1 has an inner recess 11 and a central hole 12 communicating with the inner recess. According to its design requirements, the central hole 12 needs to be bored.

[0003] Currently, the existing patent CN203471431U discloses a pneumatic fixture for boring the center hole of a spline hub, including a base comprising a horizontal plate and a vertical plate. An arc-shaped block is vertically fixed to the top right side of the vertical plate. The arc-shaped groove formed by the arc-shaped block corresponds to the clamping screw and is used to clamp the spline hub to be processed together with the clamping screw. In practical use, it has been found that because this fixture uses a double V-shaped block with one fixed and one movable (i.e., fixed and movable) for positioning and clamping, and the outer diameter of the spline hub blank has a certain deviation, this positioning method causes the spline hub center to shift, resulting in a deviation in the bored center hole. Specifically, the axis of the bored center hole is not coaxial with the axis of the spline hub's outer diameter, resulting in excessive wall thickness differences, leading to workpiece scrap and a persistently high scrap rate. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides a clamping fixture for boring the center hole of a spline hub.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: a spline hub boring hole clamping fixture, including a base, a support plate vertically arranged on the base, and pneumatic clamping fingers arranged on the support plate for clamping the spline hub. The pneumatic clamping fingers have two pneumatic fingers, and the surfaces of the two pneumatic fingers facing each other have arc-shaped grooves. A positioning seat is provided at the upper end of the base. A positioning spearhead for engaging the inner recess of the spline hub is slidably arranged on the positioning seat. A countersunk hole is provided at the bottom of the positioning seat. A retaining ring is slidably arranged on the positioning spearhead along its axial direction in the countersunk hole. A spring is provided between the retaining ring and the positioning seat.

[0006] Furthermore, the support plate and the positioning seat are L-shaped, and the support plate and the positioning seat are integrally formed.

[0007] Furthermore, the positioning spearhead is axial in shape and has a central through hole. Along its axial direction, the positioning spearhead consists of a threaded section, a smooth shaft section, and a retaining ring section from bottom to top. The retaining ring section can engage with the inner recess, and the retaining ring is threadedly engaged with the threaded section.

[0008] Furthermore, the outer diameter of the optical axis segment is smaller than the outer diameter of the retaining ring segment.

[0009] Furthermore, the positioning seat is provided with a guide hole that mates with the optical axis section. The guide hole penetrates the positioning seat and communicates with the countersunk hole. The guide hole and the countersunk hole are coaxially arranged.

[0010] Furthermore, the inner diameter of the guide hole is smaller than the inner diameter of the countersunk hole.

[0011] Furthermore, the upper end of the positioning seat is provided with an annular support for supporting the spline hub. The inner side of the annular support is provided with a groove, and an O-ring is provided in the groove. The optical axis section can pass through the O-ring.

[0012] Furthermore, a connecting ring is provided at the lower end of the positioning seat, and the connecting ring is connected to the base by a locking screw.

[0013] Furthermore, the base is provided with a clearance hole, the inner diameter of which is larger than the outer diameter of the threaded section and smaller than the inner diameter of the spring.

[0014] The beneficial effects of this application are as follows: This application clamps the spline hub by bringing the two arc-shaped grooves of the two pneumatic fingers close together. The double arc-shaped groove positioning ensures accurate center positioning and guarantees the coaxiality of the bore and spline hub after boring. Furthermore, under the action of spring force, the positioning spearhead can be inserted into the inner recess of the spline hub to prevent the spline hub from moving radially during boring, thereby improving positioning accuracy and further ensuring the coaxiality of the bore and spline hub after boring, increasing the product qualification rate and reducing blank waste. Attached Figure Description

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] Figure 2 for Figure 1 Top view;

[0017] Figure 3 It is a cross-sectional view of the utility model;

[0018] Figure 4 This is a schematic diagram of the structure of the retaining ring and spring of this utility model;

[0019] Figure 5 This is a structural diagram of the positioning spearhead;

[0020] Figure 6 This is a schematic diagram of the structure of an existing splined hub.

[0021] The markings in the diagram are: 1. Splined hub, 11. Inner recess, 12. Center hole, 2. Base, 21. Clearance hole, 3. Support plate, 4. Pneumatic gripper, 41. Pneumatic gripper, 411. Arc groove, 5. Positioning seat, 51. Countersunk hole, 52. Annular support, 521. O-ring seal, 53. Connecting ring, 6. Positioning spearhead, 61. Center through hole, 62. Snap ring section, 63. Optical shaft section, 64. Threaded section, 7. Retaining ring, 8. Spring. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] Please see Figure 1-5 This utility model provides a spline hub boring hole clamping fixture, including a base 2, a support plate 3 vertically arranged on the base 2, and pneumatic clamping fingers 4 arranged on the support plate 3 for clamping the spline hub 1. The pneumatic clamping fingers 4 have two pneumatic fingers 41, and the opposing surfaces of the two pneumatic fingers 41 have arc-shaped grooves 411 that cooperate with the outer wall of the spline hub 1. The upper end of the base 2 is provided with a positioning seat 5. The positioning seat 5 is provided with a positioning spearhead 6 that can slide up and down for engaging the inner recess 11 of the spline hub 1. The bottom of the positioning seat 5 is provided with a countersunk hole 51. A retaining ring 7 is slidably arranged in the countersunk hole 51 along its axial direction and sleeved on the positioning spearhead 6. A spring 8 is provided between the retaining ring 7 and the positioning seat 5.

[0024] When the pneumatic clamping finger 4 clamps the spline hub 1, one end of the inner recess 11 of the spline hub 1 abuts against the upper end of the positioning seat 5, and the spring 8 is in a compressed state. Under the action of the spring 8, the positioning spearhead 6 is driven to engage in the inner recess 11 to position the spline hub 1. The inner recess 11 includes a first tapered hole and a second tapered hole arranged sequentially along the spline hub 1. The large end of the second tapered hole is connected to the small end of the first tapered hole. The large end of the first tapered hole faces outward, and the small end of the second tapered hole faces the central hole 12 to be boring. The upper end of the positioning spearhead 6 is engaged in the first tapered hole.

[0025] The pneumatic gripper 4 includes a cylinder, a slide rail, and grippers. The grippers consist of two symmetrically mounted sliders on the slide rail. The grippers are connected to the cylinder piston, and the two sliders can be driven by the cylinder to move towards each other along the slide rail. The grippers are the pneumatic fingers 41. Alternatively, existing parallel pneumatic grippers can be used, as this is prior art and will not be described in detail here. Two arc-shaped grooves 411 on the two pneumatic fingers 41 are arranged opposite each other. The support plate 3 and the positioning seat 5 are L-shaped and are integrally formed. It should be noted that any parts not described in detail in this application are prior art.

[0026] Specifically, the positioning spearhead 6 is axial in shape and has a central through hole 61. The inner diameter of the central through hole 61 is larger than the inner diameter of the central hole 12. Along its axial direction from bottom to top, the positioning spearhead 6 consists of a threaded section 62, a smooth shaft section 63, and a retaining ring section 62. The retaining ring section 62 is annular and can engage with the inner recess 11. The retaining ring section 62 extends into the inner recess 11 and abuts against the inner wall of the inner recess 11. The retaining ring 7 is threadedly engaged with the threaded section 62. The outer diameter of the smooth shaft section 63 is smaller than the outer diameter of the retaining ring section 62.

[0027] In addition, the positioning seat 5 is provided with a guide hole that mates with the optical axis section 63. The guide hole passes through the positioning seat 5 and communicates with the countersunk hole 51. The guide hole and the countersunk hole 51 are coaxially arranged. The inner diameter of the guide hole is smaller than the inner diameter of the countersunk hole 51.

[0028] In addition, a connecting ring 53 is provided at the lower end of the positioning seat 5. The connecting ring 53 is integrally formed with the positioning seat 5 and is connected to the base 2 by a locking screw. The base 2 is provided with a clearance hole 21. The inner diameter of the clearance hole 21 is larger than the outer diameter of the threaded section 62 and smaller than the inner diameter of the spring 8. The base 2 is provided with fixing holes on both sides of the positioning seat 5. In use, the base 2 is fixed on the vertical boring machine by fixing bolts and fixing holes. Then, the spline hub 1 is clamped by the clamping fixture of this application, and the central hole 12 of the spline hub 1 can be bored.

[0029] This application clamps the spline hub 1 by bringing the two arc-shaped grooves 411 of the two pneumatic fingers 41 close together. The double arc-shaped grooves 411 are used for positioning, which ensures accurate center positioning and the coaxiality of the bore 12 and the spline hub 1 after boring. Furthermore, under the action of the spring 8, the positioning spearhead 6 is engaged in the inner recess 11 of the spline hub 1 to prevent the spline hub 1 from moving radially during boring, thereby improving the positioning accuracy and further ensuring the coaxiality of the bore 11 and the spline hub 1 after boring, improving the product qualification rate and reducing blank waste.

[0030] Of course, this utility model is not limited to the embodiments described above. Several other embodiments based on the design concept of this utility model are also provided below.

[0031] For example, in other embodiments, unlike the embodiments described above, the upper end of the positioning seat 5 is provided with an annular support portion 52 for supporting the spline hub 1. The inner diameter of the annular support portion 52 is equal to the inner diameter of the guide hole. When clamped, the end of the inner recess 11 of the spline hub 1 abuts against the upper end of the annular support portion 52. The inner side of the annular support portion 52 is provided with a groove, and an O-ring seal 521 is provided in the groove. The optical axis section 63 can pass through the O-ring seal 521.

[0032] It should be noted that the above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A clamping fixture for boring the center hole of a splined hub, characterized in that, The device includes a base (2), a support plate (3) vertically mounted on the base (2), and pneumatic clamping fingers (4) mounted on the support plate (3) for clamping the spline hub (1). The pneumatic clamping fingers (4) have two pneumatic fingers (41) with arc-shaped grooves (411) on the opposite surfaces of the two pneumatic fingers (41). The upper end of the base (2) is provided with a positioning seat (5). The positioning seat (5) is provided with a positioning spearhead (6) that can slide up and down for inserting into the inner recess (11) of the spline hub (1). The bottom of the positioning seat (5) is provided with a countersunk hole (51). A retaining ring (7) is provided in the countersunk hole (51) along its axial direction and is sleeved on the positioning spearhead (6). A spring (8) is provided between the retaining ring (7) and the positioning seat (5).

2. The spline hub boring center hole clamping fixture according to claim 1, characterized in that: The support plate (3) and the positioning seat (5) are L-shaped and are integrally formed.

3. The spline hub boring center hole clamping fixture according to claim 1, characterized in that: The positioning spearhead (6) is axial in shape and has a central through hole (61). The positioning spearhead (6) consists of a threaded section (64), a smooth shaft section (63), and a retaining ring section (62) along its axial direction from bottom to top. The retaining ring section (62) can engage with the inner recess (11), and the retaining ring (7) is threadedly engaged with the threaded section (64).

4. The spline hub boring center hole clamping fixture according to claim 3, characterized in that: The outer diameter of the optical axis segment (63) is smaller than the outer diameter of the retaining ring segment (62).

5. A clamping fixture for boring a splined hub according to claim 3, characterized in that: The positioning seat (5) is provided with a guide hole that cooperates with the optical axis section (63). The guide hole passes through the positioning seat (5) and communicates with the countersunk hole (51). The guide hole and the countersunk hole (51) are coaxially arranged.

6. A clamping fixture for boring a splined hub according to claim 5, characterized in that: The inner diameter of the guide hole is smaller than the inner diameter of the countersunk hole (51).

7. A clamping fixture for boring a splined hub according to claim 3, characterized in that: The upper end of the positioning seat (5) is provided with an annular support part (52) for supporting the spline hub (1). The inner side of the annular support part (52) is provided with a groove, and an O-ring seal (521) is provided in the groove. The optical axis section (63) can pass through the O-ring seal (521).

8. A clamping fixture for boring a splined hub according to claim 1, characterized in that: The lower end of the positioning seat (5) is provided with a connecting ring (53), which is connected to the base (2) by a locking screw.

9. A clamping fixture for boring a splined hub according to claim 3, characterized in that: The base (2) is provided with a relief hole (21), the inner diameter of which is greater than the outer diameter of the threaded section (64) and less than the inner diameter of the spring (8).

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