Machining method for arc locking face of sliding sleeve gear and bowl-shaped milling cutter

Abstract

The invention discloses a machining method for an arc locking surface of a sliding sleeve gear and a bowl-shaped milling cutter, and the machining method for the arc locking surface of the sliding sleeve gear comprises the following steps: S1, mounting the bowl-shaped milling cutter on a main shaft of a machining center, rotating the sliding sleeve gear around the inclined shaft until the included angle between the central axis of the bowl-shaped milling cutter and the radial direction of the sliding sleeve gear is beta, and fixing; and S2, the main shaft does linear interpolation motion downwards along the Z axis, and the main shaft rotates to drive the bowl-shaped milling cutter to do cutting motion on the arc locking face. The bowl-shaped milling cutter is used for the machining method and comprises a bowl-shaped milling cutter body, a frustum-shaped groove is formed in the cutter head of the bowl-shaped milling cutter body, at least two cutting edges are formed on the inner side wall of the frustum-shaped groove, and a chip groove extending towards the periphery of the bowl-shaped milling cutter body is formed in one side of each cutting edge. The device has the beneficial effects that the arc locking surface of the sliding sleeve gear is machined at a time, and the machining efficiency is improved; and cutter lines are eliminated, so that the locking surface is regular in shape, stable in size and high in surface quality.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical processing methods and milling cutter structures, and in particular to a processing method for a circular arc locking surface of a sliding sleeve gear and a bowl-shaped milling cutter. Background Art

[0002] As a core component of automatic transmissions, the sliding sleeve gear boasts the following characteristics: durability, excellent wear resistance, low wear, minimal material consumption, and low manufacturing costs. The machining quality of the sliding sleeve gear's arc-shaped locking surface significantly impacts noise, impact resistance, and reliability during shifting.

[0003] The existing method for processing the arc locking surface is to install a finger-shaped knife on a chamfering machine to process the locking surface. The finger-shaped knife is used for linear reciprocating interpolation along the Z axis, and the three axes are superimposed to form a compound motion. In addition, the main spindle rotates and cuts, and the four axes are linked to complete the arc locking surface processing. Each tooth needs to be processed repeatedly many times, and the processing efficiency is low. During processing, the tip of the finger-shaped knife is located at the center of tool rotation. The speed of the tip center is zero and there is no cutting force. It is squeezed with the arc locking surface, resulting in an irregular shape of the locking surface, unstable size, poor surface quality, and very obvious knife marks. In addition, due to the air avoidance of the machine tool, the tool requires a long overhang depth, the finger-shaped knife is long, and the overall structure is slender, resulting in large vibration during cutting, large tool wear and high cost. Summary of the Invention

[0004] The first purpose of the present invention is to provide a method for processing the circular arc locking surface of a sliding gear, so as to complete the circular arc locking surface of the gear in one-time processing and improve processing efficiency; the second purpose of the present invention is to provide a bowl-shaped milling cutter to eliminate tool marks, make the locking surface regular in shape, stable in size and with high surface quality.

[0005] To achieve the aforementioned first purpose, the present invention adopts the following technical solution.

[0006] A method for machining the circular arc locking surface of a sliding gear comprises the following steps: S1: mounting a bowl-shaped milling cutter on the spindle of a machining center, rotating the sliding gear around an inclined axis until the angle β between the center axis of the bowl-shaped milling cutter and the radial direction of the sliding gear is fixed; S2: performing linear interpolation motion downward along the Z axis, while rotating to drive the bowl-shaped milling cutter to cut the circular arc locking surface.

[0007] The present invention adopts the above-mentioned scheme, by setting a bowl-shaped milling cutter, which is installed on the main shaft of the machining center during machining, and the sliding gear is rotated around the inclined axis until the angle between the central axis of the bowl-shaped milling cutter and the radial direction of the sliding gear is β and fixed, so as to ensure the accuracy of the locking angle of the machined arc locking surface; then the machining center is started to make the bowl-shaped milling cutter perform linear interpolation motion downward along the Z axis on the main shaft, and at the same time rotate to perform cutting motion on the arc locking surface, so as to complete the gear arc locking surface in one-time machining, thereby improving machining efficiency.

[0008] Preferably, the angle β between the central axis of the bowl-shaped milling cutter and the radial direction of the sliding gear is obtained by the following relationship:

[0009] β=θ / 2-α, where θ is the angle between the two cutting edges of the bowl-shaped milling cutter, and α is the arc surface locking angle of the sliding gear.

[0010] In this way, the β value is obtained through the relationship between the angle between the two cutting edges of the bowl-shaped milling cutter and the arc surface locking angle of the sliding gear and the radial angle between the center axis of the milling cutter and the sliding gear, which makes it easy to ensure the accuracy of the locking angle of the arc locking surface.

[0011] Preferably, a safety gap λ is provided between the tip of the cutting edge that does not participate in cutting during machining and the outer periphery of the sliding gear, and the safety gap λ is ≥0.3 mm.

[0012] In this way, a safety gap λ≥0.3mm is provided between the tip of the cutting edge that does not participate in cutting and the outer periphery of the sliding gear, thereby preventing friction between the tip of the cutting edge and the outer periphery of the sliding gear during processing, thereby preventing the quality of the sliding gear from being affected.

[0013] To achieve the aforementioned second purpose, the present invention adopts the following technical solutions:

[0014] A bowl-shaped milling cutter, used to implement the above-mentioned processing method, includes a bowl-shaped milling cutter body, a frustum-shaped groove is formed on the cutter head of the bowl-shaped milling cutter body, at least two cutting edges are formed on the inner side wall of the frustum-shaped groove, and a chip groove extending toward the periphery of the bowl-shaped milling cutter body is formed on one side of the cutting edge.

[0015] The present invention adopts the above-mentioned scheme, by forming a conical groove on the cutter head of the bowl-shaped milling cutter body, and forming at least two cutting edges on the inner wall of the conical groove, so that the two cutting edges are at a distance from the axial center line of the milling cutter, to prevent the circular arc locking surface from being squeezed and produced by the arc locking surface when cutting, and the side walls of the conical groove provide support for the two cutting edges, so that the strength and rigidity of the cutting edges and the whole are enhanced, the vibration caused by length and strength problems during processing is eliminated, the life of the tool is improved, and the quality of the processed circular arc locking surface is guaranteed. A chip groove extending toward the outer periphery of the bowl-shaped milling cutter body is also formed on one side of the cutting edge, and the chip groove is set to be open to ensure that the chips are removed quickly and smoothly, which can significantly improve the surface roughness and dimensional accuracy of the locking surface.

[0016] Preferably, the tip of the cutting edge is formed with a circular arc edge, and the circular arc edge is located at the opening end of the frustum-shaped groove.

[0017] In this way, an arc edge is formed at the tip of the cutting edge, and the arc edge is located at the open end of the frustum-shaped groove, so that there is a set distance between the tip and the rotation center of the knife shaft to prevent extrusion between the tip and the arc locking surface to produce knife marks.

[0018] Preferably, the two cutting edges are symmetrically arranged and both protrude from the side wall of the frustum-shaped groove.

[0019] In this way, by symmetrically arranging the two cutting edges and both protruding from the side wall of the frustum-shaped groove, the cutting process is smooth, the tool loss is extremely small, and the tool cost is significantly reduced.

[0020] Preferably, an arc groove is formed between the two cutting edges, and the arc groove is located at the end away from the blade tip and at the bottom of the frustum-shaped groove.

[0021] In this way, by forming a circular arc groove between the two cutting edges and locating the circular arc groove at the end away from the tool tip and at the bottom of the frustum-shaped groove, interference between the bowl-shaped milling cutter body and the sliding gear is prevented.

[0022] Preferably, the angle θ between the two cutting edges is 45° to 90°.

[0023] In this way, the included angle θ between the cutting edges is set to 45°~90°, and the angle θ is as small as possible under the condition that the minimum safety clearance λ between the tool tip and the tooth top circle is ≥0.3mm. This can avoid overcutting between the tool tip and the outer periphery of the sliding gear and better exert the side edge cutting effect.

[0024] Preferably, an intersection is formed between the cutting edge and the baseline of the arc locking surface cross section, and the intersection forms a mirror point on the other cutting edge with the tool axis as the axis of symmetry. The distance between the intersection and the mirror point constitutes the virtual circle diameter m of the product control point, and the virtual circle diameter m of the product control point needs to satisfy the following relationship:

[0025] m=cos(β)*P*2, where β is the angle between the tool axis and the radial direction of the sleeve, and P is the curvature radius value at the intersection of the cutting edge and the base line of the arc locking surface section.

[0026] In this way, by making the diameter m of the virtual circle of the product control point between the two cutting edges satisfy the above relationship, it is easy to ensure the curvature radius of the arc locking surface.

[0027] Preferably, the distance n between the intersection of the arc edge and the virtual circle must satisfy the following relationship:

[0028] n=(L / 2-m / 2) / tan(θ / 2), where L is the diameter of the theoretical tool tip after one rotation about the tool axis.

[0029] In this way, by setting the distance between the intersection of the arc edge and the virtual circle to n to satisfy the above relationship, the depth of the arc locking surface can be ensured.

[0030] The beneficial effects of the present invention are as follows: by setting a bowl-shaped milling cutter, the bowl-shaped milling cutter is installed on the main shaft of the machining center during machining, the sleeve gear is rotated around the inclined axis until the angle between the central axis of the bowl-shaped milling cutter and the radial direction of the sleeve gear is β and fixed, so as to ensure the accuracy of the locking angle of the machined arc locking surface; then the machining center is started to make the bowl-shaped milling cutter perform linear interpolation motion downward along the Z axis on the main shaft, and at the same time rotate to perform cutting motion on the arc locking surface, so as to complete the gear arc locking surface through one-time machining, thereby improving machining efficiency. A frustum-shaped groove is formed on the cutter head of the bowl-shaped milling cutter body, and at least two cutting edges are formed on the inner wall of the frustum-shaped groove, so that the two cutting edges are at a distance from the axis of the milling cutter to prevent the arc locking surface from being squeezed and producing knife marks when the chips are cut. The side walls of the frustum-shaped groove provide support for the two cutting edges, so that the strength and rigidity of the cutting edges and the whole are enhanced, the vibration caused by length and strength problems during processing is eliminated, the life of the tool is improved, and the quality of the processed arc locking surface is guaranteed. A chip groove extending toward the outer periphery of the bowl-shaped milling cutter body is also formed on one side of the cutting edge. The chip groove is set to be open to ensure fast and smooth chip removal, which can significantly improve the surface roughness and dimensional accuracy of the locking surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a processing diagram of the present invention;

[0032] Figure 2 It is a processing schematic diagram of the present invention;

[0033] Figure 3 It is a structural diagram of the bowl-shaped milling cutter of the present invention;

[0034] Figure 4 It is a schematic diagram of the present invention during processing. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the scope of the embodiments described.

[0036] The reference numerals in the drawings of the specification include: bowl milling cutter 1 , cutting edge 11 , chip removal groove 12 , arc edge 13 , arc groove 14 , sliding gear 2 , arc locking surface 21 .

[0037] Example 1, as Figure 1 、 Figure 2 and Figure 3 As shown; a method for processing the arc locking surface of a sliding gear, comprising the following steps, S1: installing a bowl-shaped milling cutter 1 on the main shaft of a machining center, and rotating the sliding gear 2 around the inclined axis until the angle between the central axis of the bowl-shaped milling cutter 1 and the radial direction of the sliding gear 2 is β and fixed; S2: the main shaft performs linear interpolation motion downward along the Z axis, and at the same time rotates to drive the bowl-shaped milling cutter 1 to perform cutting motion on the arc locking surface 21.

[0038] See also Figure 1 、 Figure 2 and Figure 3 The angle β between the center axis of the bowl-shaped milling cutter 1 and the radial direction of the sliding gear is obtained by the following relationship: β = θ / 2-α, where θ is the angle between the two cutting edges 11 of the bowl-shaped milling cutter 1, and α is the arc surface locking angle of the sliding gear 2. The value of β is obtained by the relationship between the angle between the two cutting edges 11 of the bowl-shaped milling cutter 1, the arc surface locking angle of the sliding gear 2, and the angle between the center axis of the milling cutter and the radial direction of the sliding gear, which facilitates ensuring the accuracy of the locking angle of the arc locking surface 21.

[0039] See also Figure 1 and Figure 2 A safety gap λ is provided between the tip of the cutting edge 11 not involved in cutting and the outer periphery of the sliding gear 2 during machining. The safety gap λ is ≥ 0.3 mm. This prevents friction or overcutting between the tip of the cutting edge and the outer periphery of the sliding gear 2 during machining, which could affect the quality of the sliding gear 2.

[0040] During operation, the bowl-shaped milling cutter 1 is mounted on the tool holder, and the tool holder is then mounted on the spindle of the 3+2 machining center (the 3+2 machining center can be an AC / BC cradle, an AC / BC swing head, or other types of equipment that can meet two-axis rotation requirements and meet product requirements). The tool swing and tool length are measured, and the machining coordinate system is set. The turntable and the spring tensioning fixture are calibrated. The product is placed in the spring tensioning fixture and positioned with the tooth groove. The pedal of the control pull rod is stepped on, and the pull rod moves downward to expand the expansion sleeve and tighten the sleeve gear 2. The NC program is started, and the sleeve gear body rotates around the tilt axis to the required angle β of the arc locking surface 21 and is fixed. The spindle performs linear interpolation motion toward Z- and rotates at the same time to drive the bowl-shaped milling cutter 1 to perform cutting motion until it reaches the height set by the program. The arc locking surface 21 processing is completed, and each tooth only needs to be processed once.

[0041] Example 2, see Figure 3 A bowl-shaped milling cutter for implementing the above-mentioned processing method includes a bowl-shaped milling cutter body, a cone-shaped groove is formed on the cutter head of the bowl-shaped milling cutter body, at least two cutting edges 11 are formed on the inner side wall of the cone-shaped groove, and a chip groove 12 extending toward the periphery of the bowl-shaped milling cutter body is formed on one side of the cutting edge 11.

[0042] See also Figure 3 The cutting edge 11 has a circular arc edge 13 formed at its tip, and the circular arc edge 13 is located at the open end of the frustum-shaped groove. Thus, the circular arc edge 13 is formed at the cutting edge 11 and is located at the open end of the frustum-shaped groove, so that a distance is provided between the cutting edge and the rotation center of the cutter shaft, thereby preventing compression between the cutting edge and the circular arc locking surface 21, which would otherwise cause cutter marks.

[0043] See also Figure 3 The two cutting edges 11 are symmetrically arranged and both protrude from the sidewall of the frustum-shaped groove. In this way, by symmetrically arranging the two cutting edges 11 and both protruding from the sidewall of the frustum-shaped groove, the cutting process is smooth, the tool wear is extremely small, and the tool cost is significantly reduced.

[0044] See also Figure 3 A circular arc groove 14 is formed between the two cutting edges 11. The circular arc groove 14 is located at the end away from the tool tip and at the bottom of the frustum-shaped groove. Thus, by forming the circular arc groove 14 between the two cutting edges 11 and locating the circular arc groove 14 at the end away from the tool tip and at the bottom of the frustum-shaped groove, interference between the bowl-shaped milling cutter 1 body and the sliding gear 2 is prevented.

[0045] See also Figure 1The included angle θ between the two cutting edges 11 is 45° to 90°. By setting the included angle θ between the cutting edges 11 to 45° to 90° and making the angle θ as small as possible while ensuring a minimum safety clearance λ ≥ 0.3mm between the tool tip and the tooth addendum circle, overcutting of the tool tip and the outer periphery of the sliding gear can be avoided, thereby achieving a better side cutting effect.

[0046] See also Figure 1 , an intersection is formed between the cutting edge 11 and the cross-sectional baseline of the arc locking surface 21, and a mirror image point is formed on the other cutting edge 11 with the tool axis as the axis of symmetry. The distance between the intersection and the mirror image point constitutes the virtual circle diameter m of the product control point. The virtual circle diameter m of the product control point must satisfy the following relationship: m = cos(β)*P*2, where β is the angle between the tool axis and the radial direction of the sleeve gear, and P is the curvature radius value at the intersection of the cutting edge and the cross-sectional baseline of the arc locking surface. In this way, by ensuring that the virtual circle diameter m of the product control point between the two cutting edges 11 satisfies the above relationship, it is easy to ensure the curvature radius of the arc locking surface 21. The radial direction of the sleeve gear in the present invention refers to a vertical line along the radial direction of the sleeve gear 2 and pointing upward, and the angle β formed by the vertical line and the tool axis is less than 90°.

[0047] See also Figure 1 The distance n between the intersection of the circular cutting edge 13 and the virtual circle must satisfy the following relationship: n = (L / 2 - m / 2) / tan(θ / 2), where L is the theoretical diameter of the tool tip after one rotation about the tool axis. By setting the distance n between the intersection of the circular cutting edge 13 and the virtual circle to satisfy the above relationship, the depth of the circular locking surface 21 can be ensured.

[0048] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for machining an arc locking surface of a sliding sleeve gear, characterized in that: The following steps are included: S1: Mount the bowl milling cutter (1) on the main shaft of the machining center, and rotate the sleeve gear (2) around the tilt axis until the angle between the center axis of the bowl milling cutter (1) and the radial direction of the sleeve gear is β, and then fix it; S2: The spindle performs linear interpolation motion downward along the Z axis, and at the same time rotates to drive the bowl-shaped milling cutter (1) to perform cutting motion on the arc locking surface (21).

2. The method for machining the arc locking surface of the sliding sleeve gear according to claim 1, characterized in that: The angle β between the central axis of the bowl-shaped milling cutter (1) and the radial direction of the sliding gear is obtained by the following relationship: β=θ / 2-α, wherein θ is the angle between the two cutting edges (11) of the bowl-shaped milling cutter (1), and α is the arc surface locking angle of the sliding gear (2).

3. The method for machining the arc locking surface of the sliding sleeve gear according to claim 2, characterized in that: A safety gap λ is provided between the tip of the cutting edge (11) that does not participate in cutting during machining and the outer periphery of the sliding gear (2), and the safety gap λ is ≥0.3 mm.

4. A bowl-shaped milling cutter, characterized in that: A method for implementing the processing method described in claims 1 to 3 comprises a bowl-shaped milling cutter body, wherein a cone-shaped groove is formed on the cutter head of the bowl-shaped milling cutter body, at least two cutting edges (11) are formed on the inner side wall of the cone-shaped groove, and a chip groove (12) extending toward the periphery of the bowl-shaped milling cutter body is formed on one side of the cutting edge (11).

5. The bowl-shaped milling cutter according to claim 4, characterized in that: The tip of the cutting edge (11) is formed with a circular arc edge (13), and the circular arc edge (13) is located at the opening end of the frustum-shaped groove.

6. The bowl-shaped milling cutter according to claim 4, characterized in that: The two cutting edges (11) are symmetrically arranged and both protrude from the side wall of the frustum-shaped groove.

7. The bowl-shaped milling cutter according to claim 4, characterized in that: A circular arc groove (14) is formed between the two cutting edges (11), and the circular arc groove (14) is located at an end away from the blade tip and at the bottom of the frustum-shaped groove.

8. The bowl-shaped milling cutter according to claim 4, characterized in that: The included angle θ between the two cutting edges (11) is 45° to 90°.

9. The bowl-shaped milling cutter according to claim 5, characterized in that: An intersection is formed between the cutting edge (11) and the cross-sectional baseline of the arc locking surface (21), and a mirror image point is formed on the other cutting edge (11) with the tool axis as the axis of symmetry. The distance between the intersection and the mirror image point constitutes the virtual circle diameter m of the product control point, and the virtual circle diameter m of the product control point needs to satisfy the following relationship: m=cos(β)*P*2, where β is the angle between the tool axis and the radial direction of the sleeve gear, and P is the curvature radius value at the intersection of the cutting edge and the base line of the arc locking surface section.

10. The bowl-shaped milling cutter according to claim 9, characterized in that: The distance n between the intersection of the arc blade (13) and the virtual circle must satisfy the following relationship: n=(L / 2-m / 2) / tan(θ / 2), where L is the diameter of the theoretical tool tip after one rotation about the tool axis.

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