Machining method for tooth crest chamfer or round chamfer of spiral bevel gear

Abstract

A spiral bevel gear tooth crest chamfer or round chamfer machining method comprises the steps that the diameter of a grinding wheel needed for machining is determined according to the diameter of a spiral bevel gear tooth surface profile approximate arc; according to the design size of the tooth crest chamfer or the round chamfer of the spiral bevel gear, grinding wheel chamfers or grinding wheel round chamfers are remanufactured on the inner side and the outer side of the grinding wheel, or chamfers or arcs are remanufactured on the lower portion of the grinding wheel; determining the machining position of the initial machining tooth; the axis of the grinding wheel is perpendicular to the surface cone of the spiral bevel gear, and the feed angle of the grinding wheel is alpha. According to the method, (1) taking a gear with the tooth length of 50 mm, the addendum circle chamfering radius R of 0.2 and the tooth number of 53 as an example, the machining time is only 15.9 min, and the chamfering time of a five-axis machining center alloy milling cutter is 123 min; and (2) a grinding wheel grinding process is adopted, the machined surface is smooth, the arc is smooth, the consistency is better, the size control precision is + / -0.03 mm, and the problem of feed marks existing in an existing machining mode is solved.

Description

Technical Field

[0001] The invention relates to the field of gear processing methods, and in particular to a processing method for chamfering or rounding the tooth top of a spiral bevel gear. Background Art

[0002] At present, there are two main ways to fillet the top of spiral bevel gear teeth: one is to use a pneumatic gun to process manually and then polish it; the other is to use alloy cutter head milling on a five-axis machining center. The manual processing method has problems such as poor quality stability and uneven fillets, while the milling efficiency of the machining center is low, the surface roughness after processing is low, and both processing methods will leave tool traces. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for processing spiral bevel gear tooth top chamfers or round chamfers which is beneficial to improving processing efficiency, stabilizing processing quality and eliminating tool traces.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A method for processing a spiral bevel gear tooth top chamfer or round chamfer, comprising the following steps:

[0006] S1. Determine the grinding wheel diameter required for machining according to the diameter of the approximate arc of the spiral bevel gear tooth surface profile;

[0007] S2. According to the design size of the chamfer or round chamfer of the spiral bevel gear tooth top, the grinding wheel chamfer or the grinding wheel round chamfer is repaired on both sides of the grinding wheel; or, the chamfer or arc is repaired on the lower part of the grinding wheel;

[0008] S3, determining the processing position of the starting processing tooth;

[0009] S4. Install the spiral bevel gear and grinding wheel. The grinding wheel axis is perpendicular to the face cone of the spiral bevel gear. The grinding wheel feed angle is α to complete the processing.

[0010] As a further improvement of the above technical solution:

[0011] In step S1, a profiler is used to track the diameter of an approximate circular arc of the spiral bevel gear tooth surface profile, the tracking trajectory is parallel to the spiral bevel gear face cone, and the tracking width range is smaller than the design size of the tooth top chamfer or fillet chamfer.

[0012] In step S1, the tooth surface of the spiral bevel gear is divided into two or more sections along the length direction for evaluation.

[0013] In step S1, the profilometer is used for evaluation more than twice.

[0014] In step S1, the diameter of the grinding wheel does not exceed the minimum arc diameter of the profilometer evaluation result.

[0015] In step S2, transition chamfers for transitioning the tooth surface are provided on both sides of the grinding wheel chamfer or the grinding wheel round chamfer, and the angle of the transition chamfer is greater than the tangent angle of the tooth surface; or, transition fillets for transitioning the tooth surface are provided on both sides of the grinding wheel chamfer or the grinding wheel round chamfer, and the curvature of the transition fillet is not less than the curvature of the tooth surface.

[0016] The length of the transition chamfer is 0.5-1 mm.

[0017] In step S3, the tooth surface height is confirmed by the first probe, and the tooth surface circumferential indexing position is confirmed by the second probe.

[0018] In step S4, α=45°.

[0019] In step S4, the grinding wheel moves alone to complete the processing; or, the spiral bevel gear and the grinding wheel are interpolated in conjunction to complete the processing.

[0020] Compared with the prior art, the advantages of the present invention are as follows: the processing method of the spiral bevel gear tooth top chamfer or round chamfer disclosed by the present invention determines the grinding wheel diameter required for processing according to the diameter of the approximate arc of the spiral bevel gear tooth surface profile, and then makes corresponding chamfers or round chamfers on both sides of the grinding wheel to obtain the molding grinding wheel required for grinding processing, which is used for processing the chamfer or round chamfer of the intersection of the tooth surface and the face cone of the part, and has:

[0021] 1) Improved processing efficiency: Taking a gear with a tooth length of 50 mm, a tooth top chamfer radius R=0.2, and a tooth number of 53 as an example, the processing time of the present invention is only 15.9 minutes, while the chamfering processing time of the alloy milling cutter of the five-axis machining center is 123 minutes. The efficiency of the present invention is significantly improved.

[0022] 2) Stable processing quality: The grinding wheel grinding process is adopted, the processing surface is smooth, the arc is smooth, and the consistency is better; the dimensional control accuracy is ±0.03mm, which overcomes the problem of tool traces in machining centers and manual processing.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The utility model is a schematic diagram of the cross-sectional structure of the grinding wheel involved in the present invention.

[0025] Figure 2 It is a partial enlarged structural diagram of the grinding wheel.

[0026] Figure 3 The present invention is a schematic diagram of the cross-sectional structure of the spiral bevel gear.

[0027] Figure 4 yes Figure 3 B view.

[0028] Figure 5 It is a schematic diagram of the evaluation results of the approximate arc diameter of the spiral bevel gear tooth surface profile, where a is the convex surface and b is the concave surface.

[0029] Figure 6 It is a schematic diagram of the present invention for confirming the tooth surface height and the tooth surface circumferential indexing position.

[0030] Figure 7 It is a schematic diagram of setting the processing starting position of the present invention.

[0031] The reference numerals in the figure indicate: 1, spiral bevel gear; 2, grinding wheel; 21, grinding wheel round chamfer; 22, transition chamfer. DETAILED DESCRIPTION

[0032] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Figures 1 to 7An embodiment of a method for processing a chamfer or round chamfer of a spiral bevel gear tooth tip of the present invention is shown. This embodiment is used for round chamfering. The method for processing a chamfer or round chamfer of a spiral bevel gear tooth tip of the present invention is specifically as follows:

[0037] First, use the profiler to track the diameter of the approximate arc of the tooth surface profile of spiral bevel gear 1. The tracking trajectory is parallel to the gear face cone, and the tracking width range is less than the maximum value of the fillet chamfer. If the tooth surface is long, it can be divided into multiple sections (including two sections) for arc evaluation, and it can be evaluated more than twice to obtain an accurate approximate arc as much as possible. The tooth surface profile can be truly restored by continuously tracking and analyzing the tooth surface profile with the profile tracker. The tooth surface profile is as follows: Figure 3 and Figure 4 As shown, of course, in other embodiments, the diameter of the approximate circular arc of the tooth surface profile can also be calculated based on the design parameters of the spiral bevel gear 1. However, due to factors such as processing errors, there is inevitably a certain deviation between the theoretical calculation result and the actual result, which is not accurate enough.

[0038] The tracking results of the convex surface (i.e., working surface) and concave surface (i.e., non-working surface) of the tooth surface of the spiral bevel gear 1 in this embodiment are as follows: Figure 5 shown.

[0039] Then, according to the arc diameter evaluated by the profilometer, the required diameter of the grinding wheel 2 is determined. The diameter of the grinding wheel 2 is less than or equal to the minimum arc diameter of the profilometer evaluation result. In this embodiment, the minimum arc diameter value is 132.07728 mm. In order to ensure that circular arc interpolation can be performed, the diameter of the grinding wheel 2 is determined to be 132 mm (although the processing efficiency is higher if the diameter of the grinding wheel 2 is too large, it is easy to cause overcutting; and although the diameter of the grinding wheel 2 is too small, it is helpful to avoid overcutting, but the processing efficiency is low).

[0040] See Figure 1 and Figure 2 According to the chamfering requirement R=0.5mm, the inner and outer grinding wheel chamfers 21 are made, and the radius of the grinding wheel chamfer 21 is also 0.5mm, wherein the inner grinding wheel chamfer 21 is used to process the convex chamfer, and the outer grinding wheel chamfer 21 is used to process the concave chamfer. Of course, in other embodiments, only one arc can be made at the lower part of the grinding wheel 2, and the two sides of the arc are used to process the convex and concave chamfers respectively.

[0041] Furthermore, a transition chamfer 22 is made on each side of the grinding wheel chamfer 21. The preferred transition chamfer size is 45° (the angle needs to be greater than the tangent angle of the tooth surface) and 0.5 to 1 mm long. On the one hand, it prevents overcutting during the grinding process of the grinding wheel 2, and on the other hand, it also helps to prevent the grinding wheel 2 from breaking. Of course, in other embodiments, a transition fillet can also be made on each side of the grinding wheel chamfer 21. The curvature of the transition fillet is greater than or equal to the curvature of the tooth surface, which can also prevent overcutting and breaking during the grinding process of the grinding wheel 2. It should be noted that the starting point of the transition chamfer 22 needs to be transitioned from the end position of the grinding wheel chamfer 21 and the actual fillet of the spiral bevel gear 1 as the starting point.

[0042] See Figure 6 and Figure 7 The processing position of the starting tooth can be determined by a combination of point sampling, profiling tracking, positioning, and tool setting. In this embodiment, a tool setting and positioning method is adopted, and the tooth surface height is confirmed by the first probe, and the tooth surface circumferential division position is confirmed by the second probe.

[0043] Finally, the axis of the grinding wheel 2 is perpendicular to the gear face cone, and the feed angle is preferably 45° (of course, other feed methods can also be used in other embodiments). The grinding wheel 2 can move alone to complete the processing, or the spiral bevel gear 1 and the grinding wheel 2 can be linked to interpolate to complete the processing.

[0044] For chamfering, the grinding wheel round chamfers 21 on both sides of the grinding wheel 2 can be replaced with the required chamfers.

[0045] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for processing a spiral bevel gear tooth top chamfer or round chamfer, characterized in that: The following steps are involved: S1. Determine the diameter of the grinding wheel (2) required for machining according to the diameter of the approximate circular arc of the tooth surface profile of the spiral bevel gear (1); S2. According to the design size of the chamfer or round chamfer of the tooth top of the spiral bevel gear (1), a grinding wheel chamfer or a grinding wheel round chamfer (21) is repaired on both sides of the grinding wheel (2); or, a chamfer or arc is repaired on the lower part of the grinding wheel (2); S3, determining the processing position of the starting processing tooth; S4. Install the spiral bevel gear (1) and the grinding wheel (2), the axis of the grinding wheel (2) is perpendicular to the face cone of the spiral bevel gear (1), the feed angle of the grinding wheel (2) is α, and the processing is completed.

2. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 1, characterized in that: In step S1, a profiler is used to track the diameter of an approximate circular arc of the tooth surface profile of the spiral bevel gear (1), the tracking trajectory is parallel to the face cone of the spiral bevel gear (1), and the tracking width range is smaller than the design size of the tooth top chamfer or fillet chamfer.

3. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 2, characterized in that: In step S1, the tooth surface of the spiral bevel gear (1) is divided into two or more sections along the length direction for evaluation.

4. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 2, characterized in that: In step S1, the profilometer is used for evaluation more than twice.

5. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 4, characterized in that: In step S1, the diameter of the grinding wheel (2) does not exceed the minimum arc diameter of the profilometer evaluation result.

6. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 1, characterized in that: In step S2, transition chamfers (22) for transitioning the tooth surface are provided on both sides of the grinding wheel chamfer or grinding wheel round chamfer (21), and the angle of the transition chamfer (22) is greater than the tangent angle of the tooth surface; or, transition fillets for transitioning the tooth surface are provided on both sides of the grinding wheel chamfer or grinding wheel round chamfer (21), and the curvature of the transition fillet is not less than the curvature of the tooth surface.

7. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 6, characterized in that: The length of the transition chamfer (22) is 0.5-1 mm.

8. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to claim 1, characterized in that: In step S3, the tooth surface height is confirmed by the first probe, and the tooth surface circumferential indexing position is confirmed by the second probe.

9. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to any one of claims 1 to 8, characterized in that: In step S4, α=45°.

10. The method for processing the chamfer or round chamfer of the tooth top of a spiral bevel gear according to any one of claims 1 to 8, characterized in that: In step S4, the grinding wheel (2) moves alone to complete the processing; or, the spiral bevel gear (1) and the grinding wheel (2) move together to complete the processing.

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