Involute spline gear rolling correction push broach

Abstract

The invention provides an involute spline gear rolling correction push-type broach, which belongs to the technical field of machining equipment accessories, and is of a tubular integral structure, the tooth profile of the push-type broach is a cutting edge, the cutting edge is in an internal spline tooth profile shape, and a spline tooth part of a machined workpiece is cut, so that the tooth thickness of the spline of the machined workpiece is reduced. During use, the cutting edge is connected with a tooth part of an external spline of a workpiece. The large diameter of the push broach does not participate in correction of the large diameter of the machined workpiece spline, and the small diameter of the push broach does not participate in correction of the small diameter of the machined workpiece spline. The method is used for correcting involute spline gear rolling repair accumulation out-of-tolerance, the problem that the rejection rate is high due to the fact that gear rolling accumulation is large and parts cannot be repaired is solved, resource waste is reduced, and the manufacturing cost is reduced. The push broach is simple in structure, low in manufacturing difficulty and low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing equipment accessories, in particular to an involute spline gear rolling correction pusher. Background Art

[0002] The involute tooth profile is the most common contact surface form in mechanical transmissions, such as involute splines and gears. Its application covers nearly all moving mechanical parts. Gear rolling is one of the primary machining processes for involute splines. This chipless process offers high efficiency, high material utilization, low processing costs, and excellent mechanical strength, making it widely used in the automotive industry.

[0003] The gear rolling process is affected by a variety of factors, including tool condition, tool installation accuracy, machine tool stability, workpiece diameter, cutting speed, and workpiece material. This process is inherently unstable, leading to a significant accumulation of gear rolling failures, resulting in unqualified parts and a high scrap rate. Simply scrapping these unqualified parts wastes resources and increases manufacturing costs. Using the original gear rolling cutter for re-rolling and correction can cause tooth flaring and misalignment, making rework with the same cutter impossible. Currently, there is no established method for repairing unqualified gear rolling parts, with no relevant literature available.

[0004] Chinese invention patent publication number CN117124013A discloses a blade and assembled ball track shaping extrusion pusher. The invention features a blade with a consistent cutting edge width. After the blade enters a workpiece, the force applied to the arc cross-section of the ball track within the workpiece remains uniform. During the shaping process, the extrusion deformation and deformation recovery of the workpiece's arc cross-section are essentially the same, thereby ensuring the roughness and contour of the shaped surface. The invention also features an assembled ball track shaping extrusion pusher with a separate shank and blade design. The entire pusher is assembled, allowing users to select the appropriate blade and shank for assembly, then conduct tests or actual operations. During use, unsuitable or severely worn blades can be promptly replaced, thereby reducing tool costs. However, this invention fails to meet the requirement of not modifying the major and minor spline diameters. Summary of the Invention

[0005] In order to correct the accumulated deviation of involute spline gear rolling rework and reduce production costs, the present invention proposes an involute spline gear rolling correction pusher.

[0006] The technical solution adopted by the present invention to solve its technical problems is:

[0007] A pusher for involute spline rolling correction. It features a tubular, monolithic structure. Its tooth profile is a cutting edge with an internal spline profile. This cutting edge cuts the spline teeth of the workpiece, reducing the thickness of the workpiece's spline teeth. During use, the cutting edge contacts the external spline teeth of the workpiece. The major diameter of the pusher does not contribute to the correction of the major diameter of the workpiece's spline, and the minor diameter does not contribute to the correction of the minor diameter of the workpiece's spline.

[0008] The above-mentioned involute spline gear rolling correction pusher is provided with a top edge angle, and the top edge angle is 1-2°.

[0009] The above-mentioned involute spline gear rolling correction pusher is provided with a side clearance angle, and the side clearance angle is 10-15'.

[0010] The push cutter for the involute spline gear rolling correction mentioned above has a tooth width that is 5 to 10 mm larger than the spline tooth width of the workpiece being processed.

[0011] The above-mentioned involute spline gear rolling correction push cutter has a push cutter tooth width of 10 to 15 mm.

[0012] The push cutter for the involute spline gear rolling correction mentioned above has a major diameter that is 0.60 mm larger than the major diameter of the workpiece spline.

[0013] The push cutter for the involute spline gear rolling correction mentioned above has a minor diameter that is larger than the minor diameter of the spline of the workpiece being processed and smaller than the starting circle diameter of the involute of the spline of the workpiece being processed.

[0014] The above-mentioned involute spline gear rolling correction pusher is made of die steel.

[0015] The above-mentioned involute spline gear rolling correction pusher, the pusher is divided into circular tooth groove width S nc0 The calculation is based on the structural parameters of the workpiece being processed. The calculation formula is as follows:

[0016]

[0017] In formula (1), m n is the external spline module of the workpiece, Z is the number of teeth, M is the span, dp is the diameter of the measuring rod, d is the diameter of the divided circle, d b is the base circle diameter.

[0018] The beneficial effects of the present invention are:

[0019] An involute spline gear rolling correction pusher solves the problem of high scrap rate caused by the inability to repair accumulated large parts in gear rolling, fills the technical gap, reduces resource waste, and lowers production costs.

[0020] The utility model discloses an involute spline gear rolling correction pusher. The involute external spline gear rolling cumulative correction pusher has a simple structure, low manufacturing difficulty and low tool cost.

[0021] The invention relates to an involute spline gear rolling correction pusher and an involute external spline gear rolling cumulative correction pusher. The operation of the tool is simple and an ordinary operator can complete the correction process by hand-operating the tool, so the tool is easy to promote. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a front view of a correction push knife according to an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 Enlarged view of the M in the middle;

[0024] Figure 3 yes Figure 1 Middle AA section;

[0025] Figure 4 Schematic diagram of the relative position of the correction push knife and the workpiece in an embodiment of the present invention, where the direction of the arrow is the cutting movement direction of the correction push knife.

[0026] In the figure: 1. Correction pusher, 2. Workpiece. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] An involute spline gear rolling correction pusher, the structure is as follows Figure 3 As shown, it is used for gear rolling correction and is explained from the following three aspects.

[0029] (1) Push blade structure design

[0030] 1) Cylinder structure design. Since the workpiece is an external spline, the tooth cumulative correction pusher adopts a cylinder structure, and the internal spline tooth profile is used as the cutting edge to correct the workpiece external spline tooth. The pusher structure is shown in Figure 1 .

[0031] 2) Design of the top edge angle αe. The top edge angle αe of the correction push cutter does not participate in the cutting process and only serves to release the cutter, so the angle should not be too small. However, the tool is subject to significant impact during use, and a too large back angle will weaken the cutter teeth. Therefore, it should not be too large, preferably 1-2°.

[0032] 3) Design of side clearance angle ψ. Figure 2 As shown, the push cutter does not modify the major or minor spline diameters, only the tooth thickness on both sides. Therefore, the push cutter tooth side plays the primary cutting role. For splines with cumulative deviation, the tooth thickness deviation on one side is generally 0.02-0.05mm, resulting in a relatively small amount of cutting. To ensure the cutting force of the push cutter blade, the side clearance angle must be kept to a minimum. Furthermore, to meet the requirements for tooth strength and tool grindability, the side clearance angle must be kept to a minimum, typically 10-15'.

[0033] 4) Design of the push cutter tooth width B0. The push cutter's movement direction is from top to bottom. To increase the cutting force during the correction process, the push cutter's own weight can be used to increase the cutting force. Therefore, the push cutter's tooth width should not be too small. While ensuring that the full tooth width of the workpiece can be processed, it should be widened by 5 to 10 mm.

[0034] 5) Design of the push cutter tooth width B1. The push cutter tooth width ensures that the tool can be reused after resharpening, thus extending tool life. However, if the push cutter tooth width is too wide, due to the tooth side clearance angle, the arc tooth groove width at the small end of the tooth thickness will exceed the tooth side offset of the workpiece, preventing contact with the workpiece, achieving no cutting effect, and being meaningless. Generally, the push cutter tooth width ranges from 10 to 15 mm and can be calculated based on the push cutter's displacement coefficient.

[0035] (2) Pusher tooth shape design

[0036] Given the workpiece external spline module mn, pressure angle αn, number of teeth Z, span M, measuring rod diameter dp, involute starting circle diameter de, major diameter da, and minor diameter df, the key parameters for correcting the push cutter tooth profile are as follows:

[0037] 1) Circular tooth groove width S nc0 calculate

[0038]

[0039] 2) Calculation of large diameter da0

[0040] The correction push tool does not participate in the correction of the spline major diameter, so the push tool major diameter should be larger than the workpiece spline major diameter.

[0041] da+0.60.

[0042] 3) Calculation of the path df0

[0043] Since the pusher does not participate in the spline minor diameter correction, the pusher minor diameter should be higher than the spline minor diameter. However, in order to ensure that the involute length meets the process requirements, the pusher minor diameter should be lower than the spline involute starting circle diameter. Therefore, the pusher minor diameter df0 value range is, df <df0<de。

[0044] 4) Calculation of large diameter arc R

[0045] To enhance the push cutter's tooth root strength and reduce tool manufacturing difficulty, the arc R at the push cutter's major diameter is designed, and this arc R should not be too small. However, to avoid interference between the push cutter and the workpiece's major diameter and to ensure the workpiece's involute length, the arc R should not be too large. It is generally set at 0.1 to 0.2 times the module.

[0046] (3) Push knife material selection

[0047] Just choose mold steel that is impact-resistant and has good toughness.

Claims

1. An involute spline gear rolling correction pusher, characterized in that: Its structure is tubular and integral. The pusher tooth profile is a cutting edge. The cutting edge is an internal spline tooth profile, which cuts the spline tooth portion of the workpiece being processed, reducing the spline tooth thickness of the workpiece being processed. When in use, the cutting edge is in contact with the external spline tooth portion of the workpiece. The major diameter of the pusher does not participate in the correction of the major diameter of the spline of the workpiece being processed, and the minor diameter of the pusher does not participate in the correction of the minor diameter of the spline of the workpiece being processed.

2. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The push knife is provided with a top blade angle, and the top blade angle is 1-2 degrees.

3. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The push knife is provided with a side clearance angle, and the side clearance angle is 10-15'.

4. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The push cutter tooth width is 5 to 10 mm larger than the spline tooth width of the workpiece being processed.

5. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The width of the push knife teeth is 10 to 15 mm.

6. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The major diameter of the push tool is 0.60mm larger than the major diameter of the workpiece spline.

7. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The push tool minor diameter is larger than the spline minor diameter of the workpiece being processed and smaller than the starting circle diameter of the involute of the spline of the workpiece being processed.

8. The involute spline gear rolling correction pusher according to claim 1, characterized in that: The push knife is made of die steel.

9. The involute spline gear rolling correction pusher according to claim 1, characterized in that: Further including: Push cutter tooth groove width S nc0 The calculation is based on the structural parameters of the workpiece being processed. The calculation formula is as follows: In formula (1), m n is the external spline module of the workpiece, Z is the number of teeth, M is the span, dp is the diameter of the measuring rod, d is the diameter of the divided circle, d b is the base circle diameter.

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