Device for machining outer circle of shaft head by centering inner hole

Abstract

The utility model provides a device for machining the excircle of a shaft head by centering an inner hole, which comprises a numerical control lathe and a main shaft taper sleeve, a rotating oil cylinder is fixed at the tail end of the main shaft taper sleeve, a pull rod is connected onto the rotating oil cylinder, a chuck is fixed at the front end of the main shaft taper sleeve, and a clamping jaw is arranged on the chuck. The supporting sleeve is inserted into a taper hole of the spindle taper sleeve through the centering taper sleeve, the other end of the supporting sleeve penetrates through a center hole of the chuck to extend outwards, a core rod in sliding fit is arranged in an inner cavity of the supporting sleeve and connected with the pull rod through a threaded rod, the other end of the core rod extends towards the middle, the diameter is gradually reduced, and the outer contour is of a taper structure. Three rectangular through grooves are evenly distributed in the circumferential face of the outer end of the supporting sleeve, and expansion core movable blocks in clearance fit are embedded in the through grooves. The utility model can reduce working procedures and reduce cost, and is suitable for batch production.

Description

Technical Field

[0001] This utility model relates to the field of automotive structural technology, specifically to a device for machining the outer circle of a shaft head by centering the inner hole. Background Technology

[0002] Forged shaft head products require the inner hole and outer circle to be concentric, such as Figure 1 The shaft head N shown in the figure needs to ensure the wall thickness difference to avoid affecting the strength performance due to uneven wall thickness difference. The current processing method is to first machine the outer circle, and then machine the inner hole by centering the outer circle, or to first drill the center hole by centering the inner hole, and then machine the outer circle by centering the center hole to indirectly ensure the wall thickness difference between the inner hole and the outer circle.

[0003] In the process of realizing this utility model, the inventors discovered that:

[0004] Of these two methods, the first method results in a heavier blank and more processes, while the second method requires that the inner hole at the small end cannot be drilled through, leaving a blind hole. Further drilling and boring processes are then added, resulting in longer processing steps, higher costs, and no price advantage. Neither of these methods can meet the increasingly fierce competitive environment of the current automotive industry. Summary of the Invention

[0005] Invention concept: To reduce costs, the inner hole of a shaft head blank is forged directly to the finished size, retaining the forging surface, punching through the inner hole, and leaving machining allowance on the outer diameter. During machining, the outer diameter is machined directly using the self-centering inner hole, reducing machining steps. However, due to the relatively long shaft head, directly using a chuck to machine the outer diameter from the inner hole is not feasible (due to excessive overhang). Therefore, to increase the positioning stability of the inner hole, auxiliary clamping needs to be considered at the other end of the shaft head's inner hole.

[0006] In order to solve the problems existing in the prior art, this utility model provides a device for machining the outer circle of a shaft head by centering the inner hole, which can reduce the number of processes, reduce costs, and is suitable for mass production.

[0007] Therefore, the technical solution of this utility model is as follows: a device for machining the outer circle of a shaft head by centering the inner hole, comprising a CNC lathe and a spindle taper sleeve mounted on the CNC lathe, characterized in that: a rotary cylinder is fixed to the tail end of the spindle taper sleeve via a mounting seat, a pull rod is connected to the rotary cylinder, the pull rod passes through the mounting seat and extends along the inner cavity of the spindle taper sleeve to the other end, a threaded bar is connected to the end of the pull rod, and a chuck is fixed to the front end of the spindle taper sleeve, the chuck being provided with jaws.

[0008] It also includes a support sleeve, one end of which is fixed with a centering cone sleeve. The support sleeve is inserted into the tapered hole of the spindle cone sleeve through the centering cone sleeve. The other end of the support sleeve extends outward through the center hole of the chuck. The inner cavity of the support sleeve is provided with a sliding mandrel. One end of the mandrel is threadedly connected to a threaded bar. The other end of the mandrel extends towards the middle with a gradually decreasing diameter and a tapered outer contour.

[0009] Three rectangular through slots are evenly distributed on the circumferential surface of the outer end of the support sleeve. An expansion core movable block with clearance fit is embedded in the through slot. The three expansion core movable blocks form an inner conical surface structure that fits with the outer conical surface of the mandrel. The support sleeve at the location where the expansion core movable block is installed has two spaced annular grooves on the circumferential direction. An elastic ring is fitted in the annular groove, and the expansion core movable block has a corresponding groove.

[0010] Preferably, the outer end face of the chuck has multiple stepped surfaces with decreasing heights, forming a support portion for shafts of different inner diameters. This makes it applicable to shafts of different inner diameters, increasing versatility.

[0011] Preferably, the mounting base includes a cylindrical body, one end of which is fixed with a connecting plate. The connecting plate has mounting holes, and the rotary cylinder is fixed to the outside of the connecting plate with screws. The other end of the cylindrical body is fixed to the flange at the tail end of the spindle tapered sleeve with a stop and screws. This ensures installation strength while facilitating disassembly and assembly, and allowing the tie rod to pass through.

[0012] Preferably, the support sleeve, mandrel, and expansion block have a hardness of HRC48-55 to ensure strength and extend service life.

[0013] Beneficial Effects: This utility model provides an internal hole positioning tool for machining shaft heads. One end of the shaft head's internal hole is directly tightened using a lathe chuck, while the other end is tightened using an expansion mandrel connecting block. A pull rod is connected to the lathe's spindle taper sleeve. Tightening and loosening are achieved by a rotating hydraulic cylinder at the tail of the spindle taper sleeve. The left-right movement of the mandrel's conical surface drives the radial movement of the expansion mandrel connecting block for clamping and loosening. This structure can be directly installed on a conventional lathe or a CNC lathe and is suitable for shaft head products where the internal hole does not require machining, but the external diameter machining requires high coaxiality with the internal hole. Attached Figure Description

[0014] Figure 1 This is an assembly structure diagram of this utility model.

[0015] Figure 2 This is a structural diagram of the centering cone sleeve of this utility model.

[0016] Figure 3 This is a structural diagram of the expansion core movable block of this utility model.

[0017] Figure 4 This is a structural diagram of the mandrel of this utility model.

[0018] Figure 5 This is an exploded view of the connection structure of the mounting base of this utility model.

[0019] Figure 6 This is a structural diagram of the chuck claw of this utility model.

[0020] Figure 7 This is a schematic diagram of the cooperation between the mandrel and the expanding core movable block of this utility model.

[0021] The figure shows: 1. Spindle taper sleeve; 2. Mounting seat; 3. Rotary cylinder; 4. Tie rod; 5. Threaded bar; 6. Chuck; 7. Claw; 8. Support sleeve; 9. Centering taper sleeve; 10. Mandrel; 11. Expanding core moving block; 12. Elastic ring; N, shaft end. Detailed Implementation

[0022] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings, but this embodiment should not be construed as a limitation of this utility model.

[0023] This utility model is as follows Figures 1 to 7 As shown:

[0024] A device for machining the outer diameter of a shaft head using internal centering includes a CNC lathe and a spindle taper sleeve 1 mounted on a KW50 CNC lathe. A L1225 NEW (JY-1225) rotary cylinder 3 is fixed to the tail end of the spindle taper sleeve via a mounting base 2. A pull rod 4 is connected to the rotary cylinder, extending through the mounting base along the inner cavity of the spindle taper sleeve to the other end. A threaded bar 5 is connected to the end of the pull rod (which can be fixed by spot welding or radial screws to prevent rotation). A 315 chuck 6 is fixed to the front end of the spindle taper sleeve, and the chuck has jaws 7.

[0025] It also includes a support sleeve 8, one end of which is fixed with a centering cone sleeve 9. The support sleeve is inserted into the tapered hole of the spindle cone sleeve through the centering cone sleeve. The other end of the support sleeve extends outward through the center hole of the chuck. The inner cavity of the support sleeve is provided with a sliding mandrel 10. One end of the mandrel is threadedly connected to a threaded bar (to prevent rotation, it can be fixed by spot welding or radial countersunk screws). The other end of the mandrel extends towards the middle with a gradually decreasing diameter and a tapered outer contour.

[0026] Three rectangular through slots 81 are evenly distributed on the circumferential surface of the outer end of the support sleeve 8. An expansion core movable block 11 with clearance fit is embedded in the through slot. The three expansion core movable blocks form an inner conical surface structure and cooperate with the outer conical surface of the core rod. The support sleeve at the installation location of the expansion core movable block has two spaced annular grooves 82 in the circumferential direction. An elastic ring 12 is fitted in the annular groove. The expansion core movable block has a corresponding groove 111.

[0027] The outer end face of the chuck 7 has multiple stepped surfaces 71 with decreasing heights, forming a support for shafts with different inner diameters. This makes it suitable for shafts with different inner diameters, increasing its versatility.

[0028] Mounting base 2 includes a cylindrical body, one end of which is fixed with a connecting plate 21. The connecting plate has mounting holes, and the rotary cylinder is fixed to the outside of the connecting plate with screws. The other end of the cylindrical body is fixed to the flange 22 at the tail end of the spindle tapered sleeve with a stop and screws. This ensures installation strength while facilitating disassembly and assembly, and allowing the tie rod to pass through.

[0029] The support sleeve 8, mandrel 10, and expansion block 11 have a hardness of HRC48-55 to ensure strength and extend service life.

[0030] The working principle of this utility model:

[0031] The inner hole of the large end of the shaft head to be processed is tightened by a chuck through the jaws, and the other end of the inner hole is further clamped by the cooperation of a mandrel and a mandrel expansion block.

[0032] When in use, after the chuck tightens the inner hole of the large end of the workpiece through the jaws, the rotating cylinder clamps it, which drives the pull rod to move to the left. The mandrel moves to the left as well. The conical surface of the mandrel drives the expanding mandrel moving block to slide outward radially along the through groove, tightening the inner wall of the shaft head from the inside to the outside and completing the auxiliary clamping.

[0033] After machining the outer diameter and end face of the workpiece, loosen the chuck jaws, rotate the hydraulic cylinder to relax, drive the pull rod to move to the right, and drive the mandrel to move simultaneously. Under the elastic force of the elastic ring, the expanding mandrel block slides back to its original position radially inward along the through groove, and the shaft head is removed, completing the machining.

[0034] Any aspects not described in detail in this specification are techniques well-known in the art.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for machining the outer diameter of a shaft head using an internal hole centering method, comprising a CNC lathe and a spindle taper sleeve mounted on the CNC lathe, characterized in that: The tail end of the spindle taper sleeve is fixed with a rotary cylinder via a mounting base. A pull rod is connected to the rotary cylinder. The pull rod passes through the mounting base and extends along the inner cavity of the spindle taper sleeve to the other end. A threaded bar is connected to the end of the pull rod. A chuck is fixed to the front end of the spindle taper sleeve, and the chuck is equipped with jaws. It also includes a support sleeve, one end of which is fixed with a centering cone sleeve. The support sleeve is inserted into the tapered hole of the spindle cone sleeve through the centering cone sleeve. The other end of the support sleeve extends outward through the center hole of the chuck. The inner cavity of the support sleeve is provided with a sliding mandrel. One end of the mandrel is threadedly connected to a threaded bar. The other end of the mandrel extends towards the middle with a gradually decreasing diameter and a tapered outer contour. Three rectangular through slots are evenly distributed on the circumferential surface of the outer end of the support sleeve. An expansion core movable block with clearance fit is embedded in the through slot. The three expansion core movable blocks form an inner conical surface structure that fits with the outer conical surface of the mandrel. The support sleeve at the location where the expansion core movable block is installed has two spaced annular grooves on the circumferential direction. An elastic ring is fitted in the annular groove, and the expansion core movable block has a corresponding groove.

2. The apparatus for machining the outer diameter of a shaft head by centering the inner hole according to claim 1, characterized in that: The outer end face of the chuck is provided with multiple stepped surfaces with decreasing heights, forming a support for shaft heads with different inner diameters.

3. The apparatus for machining the outer diameter of a shaft head by centering the inner hole according to claim 1 or 2, characterized in that: The mounting base includes a cylinder, one end of which is fixed with a connecting plate. The connecting plate has mounting holes. The rotary cylinder is fixed to the outside of the connecting plate by screws. The other end of the cylinder is fixed to the flange at the tail end of the spindle tapered sleeve by a stop and screws.

4. The apparatus for machining the outer diameter of a shaft head by centering the inner hole according to claim 1 or 2, characterized in that: The hardness of the support sleeve, mandrel, and expansion block is HRC48-55.

5. The apparatus for machining the outer diameter of a shaft head by centering the inner hole according to claim 3, characterized in that: The hardness of the support sleeve, mandrel, and expansion block is HRC48-55.

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