Inner-groove large-rake-angle double-edge cutting blade for machining inner inverted conical teeth of synchronizer gear sleeve

Abstract

The invention discloses an inner-groove large-rake-angle double-edge cutting blade for machining inner inverted conical teeth of a synchronizer gear sleeve, which comprises a clamping part and a cutting part, and the top surface of the cutting part is a first cutting rake angle surface and a second cutting rake angle surface which are downwards symmetrical and inwards grooved; a pair of first cutting rear angle faces are symmetrically arranged on the front end face of the cutting part in the direction of the rear end face, and a pair of second cutting rear angle faces are symmetrically arranged on the rear end face of the cutting part in the direction of the front end face. The first cutting rear angle surface, the first cutting front angle surface and the second cutting front angle surface form a main cutting edge respectively; and the second cutting rear angle surface forms an auxiliary cutting edge with the first cutting front angle surface and the second cutting front angle surface respectively. Through the design of the double-edge symmetrical cutting front angle surface, the first cutting rear angle surface and the second cutting rear angle surface, the strength of the main cutting edge is enhanced, the tipping possibility of the cutting blade in the use process is reduced, the service life of the cutting blade is ensured, the time consumed by frequently changing the blade is avoided, and the service life of the blade is prolonged.

Description

Technical Field

[0001] This invention relates to the field of gear machining technology, and specifically to a double-edged cutting blade with a large rake angle for machining the inner groove of the inverted bevel teeth inside a synchronizer sleeve. Background Technology

[0002] In modern car transmissions, synchronizers are widely used to complete gear shifting; the inverted bevel teeth on the synchronizer sleeve ensure that the engaged gear is secure and reliable, and play a role in preventing gear slippage.

[0003] Traditional methods for machining the tapered section on synchronizer sleeves include the extrusion method. This method uses extrusion to machine the tapered section, which is prone to plastic deformation. This deformation causes a change in the thickness in the cumulative direction. Even when the thicknesses are not in the same position, the amount of deformation caused by extrusion will result in different cumulative thicknesses at different positions. This difference in cumulative thickness at different positions leads to low precision of the machined workpiece, high noise during gear engagement, and a tendency to break teeth.

[0004] To address the shortcomings of the extrusion method in machining inverted cones, a high-speed rotary cutting method based on the internal cycloid to approximate the involute has been proposed for machining inverted cones on synchronizer sleeves. This method significantly improves machining accuracy compared to the extrusion method. However, the existing single-edged cutting inserts for this method require two separate inserts to machine the left and right sides of the tooth groove during use. This results in high cost, short lifespan, poor cutting edge rigidity, and a tendency for chipping and breakage, thus necessitating frequent insert replacements during the machining process. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a double-edged cutting insert with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve. This solves the problems of existing single-edged cutting inserts, which require two separate inserts to machine the left and right sides of the tooth groove, resulting in high cost, short lifespan, poor cutting edge rigidity, and susceptibility to chipping and breakage.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a double-edged cutting blade with a large rake angle for machining the inner groove of the inner conical tooth of a synchronizer sleeve, comprising a clamping part and a cutting part connected and arranged on the clamping part, wherein the top surface of the cutting part is a first cutting rake angle surface and a second cutting rake angle surface with downward symmetrical concave grooves.

[0007] The cutting part has a pair of first cutting rear facets symmetrically arranged on the front end facing the rear end facing the rear end facing the front end facing the cutting part.

[0008] The distance between the pair of first cutting rear facets on one side of the front end face of the cutting part gradually increases from the top to the bottom surface, and the distance between the pair of first cutting rear facets on one side of the top surface of the cutting part gradually increases from the front end to the rear end face.

[0009] The distance between the pair of second cutting rear facets on the side of the rear end face of the cutting part gradually increases from the top to the bottom face, and the distance between the pair of first cutting rear facets on the side of the top face of the cutting part gradually increases from the rear end face to the front end face.

[0010] The portions of the pair of first cutting rear facets that contact the first cutting front facet and the second cutting front facet respectively form the main cutting edge for cutting the inverted bevel teeth of the synchronizer sleeve to be machined.

[0011] The portions of the pair of second cutting rake angle surfaces that contact the first cutting rake angle surface and the second cutting rake angle surface respectively form secondary cutting edges for cutting the transition angle between the end of the inverted bevel tooth and the straight tooth of the workpiece.

[0012] The present invention also has the following technical features: A large rake angle is formed between the first and second rake angle surfaces. The aforementioned The range is 140° to 160°.

[0013] The first cutting rear angle surface forms a rear angle with the central symmetry plane. The aforementioned The range is 5° to 8°, and the second cutting rake angle surface forms a rake angle with the central symmetry plane. The aforementioned The range is 10° to 15°.

[0014] The inclination angle of the two main cutting edges The following relationship must be satisfied: =Atn(tan( / 2)*cos( ±0.1° The inclination angle of the two main cutting edges formed by the intersection of the rake face and the first clearance face affects the anti-disengagement performance of the machined inverted bevel gear. The pitch circle angle of the inverted bevel teeth inside the synchronizer sleeve to be processed is given by the product drawing; The pressure angle of the end face of the inverted bevel tooth pitch circle inside the synchronizer sleeve to be processed is given by the product drawing.

[0015] The axial lengths Lt of the two secondary cutting edges satisfy the following relationship: Lt=(Sw3-Sw1) / 2*tanγ+(0.2~0.4)mm Where Sw3 = Sw1 + 2 * L1 * tan ( / 2); Lt is the axial length of the secondary cutting edge; Sw1 is the width of the tooth groove at the thicker end of the inverted cone tooth, given in the product drawing; Sw3 is the width of the tooth groove at the inflection point of the inverted cone end; L1 is the effective length of the inverted cone inside the synchronizer sleeve to be machined, see Figure 5 Given by the product drawing, γ is the transition angle between the end of the inverted conical tooth and the straight tooth inside the synchronizer sleeve to be processed.

[0016] The height of the cutting part satisfies the following relationship: h1 = H + (1~2) mm Where h1 is the height of the cutting part of the body; H is the tooth depth of the inverted conical tooth inside the synchronizer sleeve of the workpiece to be processed; and the thickness LD of the clamping part is in the range of 2.5~3.2mm.

[0017] The length of the clamping part satisfies the following relationship: Le = (L1 + 0.4~0.6mm) + Lt Where Le is the length of the clamping part, L1 is the effective length of the inverted conical tooth inside the synchronizer sleeve to be machined, and Lt is the axial length of the secondary cutting edge, which is used to cut the transition chamfer between the inverted conical tooth and the straight tooth.

[0018] The first rake angle, the second rake angle, the first clearance angle, and the second clearance angle are all non-developable ruled surfaces.

[0019] The rear end face and bottom face of the clamping part are also provided with a chamfer to prevent misalignment.

[0020] Compared with the prior art, the present invention has the following technical effects: (I) The double-edged cutting insert with a large rake angle for machining the inner groove of the inner conical tooth of the synchronizer sleeve provided by the present invention is designed with a double-edged symmetrical cutting rake angle surface, a first cutting clearance angle surface and a second cutting clearance angle surface, which enhances the strength of the main cutting edge, greatly reduces the possibility of the cutting insert chipping during use, ensures the service life of the cutting insert, thereby avoiding the time wasted by frequent tool changes and improving the life of the cutting insert.

[0021] (II) The double-edged cutting insert with a large rake angle for machining the inner groove of the inner concave tooth of the synchronizer sleeve provided by the present invention increases the sharpness of the cutting insert by adopting a symmetrical concave large rake angle surface with the cutting edge tilted downward, while ensuring the strength of the main cutting edge and improving the cutting effect.

[0022] (III) The double-edged cutting insert with a large rake angle for machining the inner groove of the inverted conical tooth of the synchronizer sleeve provided by the present invention adopts a double-edged symmetrical structure design. Two main cutting edges and two secondary cutting edges are formed on the cutting part by cutting the rake angle surface, the first cutting clearance angle surface and the second cutting clearance angle surface. One insert replaces the original two left single-edged and right single-edged inserts, which can reduce the cost of the insert.

[0023] (IV) The present invention provides a double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth of the synchronizer sleeve. It has a simple structure and is easy to operate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the double-edged cutting insert with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve according to the present invention. Figure I .

[0025] Figure 2 This is a schematic diagram of the overall structure of the double-edged cutting insert with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve according to the present invention. Figure II .

[0026] Figure 3 This is a side view of the present invention.

[0027] Figure 4 This is a top view of the present invention.

[0028] Figure 5 This is a front view schematic diagram of the present invention.

[0029] Figure 6 A schematic diagram of the inverted conical teeth inside the synchronizer sleeve.

[0030] Figure 7 A schematic diagram showing the relationship between the front and rear tooth groove widths, end face pressure angles, and total tooth height of an internal inverted bevel tooth.

[0031] Figure 8 Diagram showing the inverted conical shank with internal conical teeth and the clamping of a double-edged, internally grooved insert with a large rake angle.

[0032] The meanings of the labels in the attached diagram are as follows: 1-Clamping part, 2-Cutting part, 3-First cutting rake angle face, 4-Second cutting rake angle face, 5-First cutting clearance angle face, 6-Second cutting clearance angle face.

[0033] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0034] Unless otherwise specified, all components in this invention are components known in the prior art.

[0035] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0036] Example 1: This embodiment provides a double-edged cutting insert with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve, such as... Figures 1-8 As shown, it includes a clamping part 1 and a cutting part 2 connected to the clamping part 1. The top surface of the cutting part 2 is a first cutting rake angle surface 3 and a second cutting rake angle surface 4 with downward symmetrical concave grooves.

[0037] The cutting part 2 has a pair of first cutting rear facets 5 symmetrically arranged on the front end facing the rear end facing the rear end facing the front end facing the cutting part 2, and a pair of second cutting rear facets 6 symmetrically arranged on the rear end facing the front end facing the cutting part 2.

[0038] The distance between the pair of first cutting rear facets 5 located on the front end face of the cutting part 2 gradually increases from the top to the bottom surface, and the distance between the pair of first cutting rear facets 5 located on the top surface of the cutting part 2 gradually increases from the front end to the rear end face.

[0039] The distance between the pair of second cutting rear facets 6 located on the rear end face of the cutting part 2 gradually increases from the top to the bottom surface, and the distance between the pair of first cutting rear facets 5 located on the top surface of the cutting part 2 gradually increases from the rear end face to the front end face.

[0040] The portion of the pair of first cutting rear facets 5 that contacts the first cutting front facet 3 and the second cutting front facet 4 respectively forms the main cutting edge for cutting the inverted bevel teeth of the synchronizer sleeve to be machined.

[0041] The portion of the pair of second cutting rake facets 6 that contacts the first cutting rake facet 3 and the second cutting rake facet 4 respectively forms a secondary cutting edge for cutting the transition angle between the end of the inverted bevel tooth and the straight tooth of the workpiece.

[0042] This application enhances the strength of the main cutting edge by using a double-edged symmetrical first rake angle surface 3 and second rake angle surface 4, a symmetrical pair of first clearance angle surfaces 5 and a symmetrical pair of second clearance angle surfaces 6, which greatly reduces the possibility of chipping during use, ensures the service life of the cutting edge, avoids the time wasted by frequent tool changes, and improves the life of the cutting edge.

[0043] As a preferred embodiment: A large cutting rake angle is formed between the first cutting rake angle surface 3 and the second cutting rake angle surface 4. The aforementioned The range is 140° to 160°; it can be adjusted according to the sharpness of the blade.

[0044] The first cutting rear angle surface 5 forms a rear angle with the central symmetry plane. The aforementioned The range is 5° to 8°, and the second cutting rear angle surface 6 forms a rear angle with the central symmetry plane. The aforementioned The range is 10° to 15°; the size is adjustable, and the trend is that the larger the back angle, the farther the first cutting back angle surface 5 and the second cutting back angle surface 6 are from the machined surface, and the safer it is.

[0045] Large rake angle of cutting 140° to 160° The design offers a sharper cut and smoother chip breaking compared to existing technologies. The tool tip is also more impact-resistant, reducing the chipping probability to approximately 1 / 10 of the original. Furthermore, the double-edged design allows for sequential cutting of both sides of the tooth groove during a single workpiece clamping, eliminating the need for clamping and tool setting compared to the original tool, which required two workpiece inversions. This doubles the cycle time and increases productivity. As a preferred embodiment: The inclination angle of the two main cutting edges The following relationship must be satisfied: =Atn(tan( / 2)*cos( ±0.1° The inclination angle of the two main cutting edges formed by the intersection of the rake face and the first clearance face affects the anti-disengagement performance of the machined inverted bevel gear. The pitch circle angle of the inverted bevel teeth inside the synchronizer sleeve to be processed is given by the product drawing; The pressure angle of the end face of the inverted bevel tooth pitch circle inside the synchronizer sleeve to be processed is given by the product drawing.

[0046] In this embodiment It is 4.99°, αd is the blade anti-misalignment chamfer, see Figure 3 .

[0047] As a preferred embodiment: like Figure 4 As shown, the axial lengths Lt of the two secondary cutting edges satisfy the following relationship: Lt=(Sw3-Sw1) / 2*tan(γ)+(0.2~0.4)mm Where Sw3 = Sw1 + 2 * L1 * tan ( / 2); Lt is the axial length of the secondary cutting edge; such as Figure 3As shown; Sw1 is the width of the tooth groove at the thicker end of the inverted cone, given in the product drawing; Sw3 is the width of the tooth groove at the inflection point of the inverted cone. L1 is the effective length of the inverted cone inside the synchronizer sleeve to be processed, see... Figure 6 Given from the product drawing, γ is the transition angle between the end of the inverted conical tooth and the straight tooth inside the synchronizer sleeve to be processed.

[0048] In this embodiment, the γ angle is 51.5°±30′; The pitch circle of the inverted cone inside the synchronizer sleeve is fully expanded, as given in the product drawing.

[0049] In this embodiment, the length of Lt is 1.1 mm.

[0050] As a preferred embodiment: like Figure 3 As shown, the height of the cutting part 2 satisfies the following relationship: h1 = H + (1~2) mm, Where h1 is the height of the cutting part of the body, and H is the tooth depth of the inverted bevel teeth inside the synchronizer sleeve of the workpiece, see Figure 7 The thickness LD of the clamping part 1 is in the range of 2.5~3.2mm.

[0051] In this embodiment, h1 is selected as 4.8mm.

[0052] The thickness LD of the clamping part 1 ensures a certain strength while preventing interference between the thickness direction and the tooth side; depending on the groove type of the tool holder, it can vary and is generally selected between 2.5 and 3.2 mm. In this embodiment, the thickness is 3.2 mm.

[0053] As a preferred embodiment: The length of the clamping part 1 satisfies the following relationship: le = (L1 + 0.4~0.6mm) + Lt Where le is the length of clamping part 1, L1 is the effective length of the inverted conical tooth inside the synchronizer sleeve to be processed, and Lt is the axial length of the secondary cutting edge, which is used to cut the transition chamfer between the inverted conical tooth and the straight tooth.

[0054] In this embodiment, the length of le is preferably 9mm.

[0055] like Figure 5 As shown, the connection points of the pair of first cutting rear facets 5 with the second cutting rear facets 6 in their respective directions form inverted cone inflection points. The distance DX from the inverted cone inflection point to the center of the body thickness direction determines the cycloidal characteristic parameters, which can be adjusted and uniquely correspond to the cycloidal cutting path.

[0056] Calculation method: The width of the inverted bevel tooth groove inside the synchronizer sleeve to be processed is adjustable by human, and its DX=DX1 / 2 is selected between 0.5~1.2mm. In this embodiment, 1.1mm is selected.

[0057] DX1 is the distance between the two inverted cone inflection points.

[0058] like Figure 3 and Figure 8 As shown, in this embodiment, HD is 12.7mm, and the total height of the body is given by the formula HD=FR-L, while also satisfying HD≥h1+4~5mm.

[0059] Where L is the distance from the positioning surface of the tool holder to the axis, FR is the cycloidal characteristic parameter, HD is the total height of the insert body, and h1 is the height of the cutting part 1.

[0060] Since FR is a cycloidal characteristic parameter and cannot be easily adjusted, L can be adjusted if the conditions are not met; where FR=sqrt(E^2-DX^2); sqrt is the square root, where E is the cycloidal characteristic parameter of the cycloidal trajectory of the blade; D is the diameter of the tool holder, D=2*(FR-h1-△), △=1~2mm.

[0061] As a preferred embodiment: The first rake angle surface 3, the second rake angle surface 4, the first clearance angle surface 5, and the second clearance angle surface 6 are all non-developable ruled surfaces.

[0062] To avoid interference between the cutting part 2 and the already cut surface.

[0063] As a preferred embodiment: The rear end face and bottom face of the clamping part 1 are also provided with a chamfer 7 for preventing misalignment.

[0064] The specific working process of this invention: like Figure 6 Since the workpiece tapered cone is symmetrically distributed in two places along the axial direction, it is necessary to ensure that the second cutting rear face of the two identical blades is installed back to back during installation. Therefore, the bottom front end of the clamping part 2 needs to be provided with a mis-proof positioning chamfer 7, which is directly above the second cutting rear face 6, to prevent the two identical blade bodies from being installed in the wrong position on the tool holder at the same time. The preferred mis-proof angle is 30°.

[0065] Input the designed cutting blade path parameters into the machine tool. Since the double-edged cutting blade is uniquely associated with the cutting path, the machine tool only needs to execute the cutting program, and the cutting blade will cut according to the predetermined cutting path.

[0066] The above technical solutions are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived by those skilled in the art within the scope of the technology disclosed in the present invention without creative effort are covered within the scope of protection of the present invention.

Claims

1. A double-edged cutting insert with a large rake angle for machining the inner groove of the inverted conical teeth inside a synchronizer sleeve, comprising a clamping part (1) and a cutting part (2) connected and arranged on the clamping part (1), characterized in that, The top surface of the cutting part (2) is a first cutting rake angle surface (3) and a second cutting rake angle surface (4) with downward symmetrical concave grooves. The cutting part (2) has a pair of first cutting rear angle surfaces (5) symmetrically arranged on the front end facing the rear end facing the rear end facing the front end facing the cutting part (2), and a pair of second cutting rear angle surfaces (6) symmetrically arranged on the rear end facing the front end facing the cutting part (2). The distance between the pair of first cutting rear facets (5) located on the front end face of the cutting part (2) gradually increases from the top to the bottom surface, and the distance between the pair of first cutting rear facets (5) located on the top surface of the cutting part (2) gradually increases from the front end to the rear end face. The distance between the pair of second cutting rear facets (6) on the side of the rear end face of the cutting part (2) gradually increases from the top to the bottom surface, and the distance between the pair of first cutting rear facets (5) on the side of the top surface of the cutting part (2) gradually increases from the rear end face to the front end face. The portions of the pair of first cutting rear facets (5) that contact the first cutting front facet (3) and the second cutting front facet (4) respectively form the main cutting edge; The portions of the pair of second cutting rake faces (6) that contact the first cutting rake face (3) and the second cutting rake face (4) respectively form secondary cutting edges.

2. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 1, characterized in that, A large cutting rake angle is formed between the first cutting rake angle surface (3) and the second cutting rake angle surface (4). The aforementioned The range is 140° to 160°; The first cutting rear angle surface (5) forms a rear angle with the central symmetry plane. The aforementioned The range is 5° to 8°; The second cutting rake face (6) forms a rake angle with the central symmetry plane. The aforementioned The range is 10° to 15°.

3. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 1, characterized in that, The inclination angle of the two main cutting edges The following relationship must be satisfied: =Atn(tan( / 2)*cos( ))±0.1° The angle of inclination of the two main cutting edges formed by the intersection of the rake angle face and the first clearance angle face. The pitch circle angle of the inner conical teeth of the synchronizer sleeve to be machined. The pressure angle of the end face of the inverted bevel tooth pitch circle inside the synchronizer sleeve to be processed.

4. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 3, characterized in that, The axial lengths Lt of the two secondary cutting edges satisfy the following relationship: Lt=(Sw3-Sw1) / 2*tan(γ)+(0.2~0.4)mm; Where Sw3 = Sw1 + 2 * L1 * tan ( / 2), Lt is the axial length of the secondary cutting edge, Sw1 is the width of the tooth groove at the thick end of the inverted cone tooth, Sw3 is the width of the tooth groove at the inflection point of the inverted cone end, l1 is the effective length of the inverted cone inside the synchronizer sleeve to be machined, and γ is the transition angle between the end of the inverted cone tooth and the straight tooth inside the synchronizer sleeve to be machined.

5. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 1, characterized in that, The height of the cutting part (2) satisfies the following relationship: h1 = H + (1~2) mm, Where h1 is the height of the cutting part of the body, H is the tooth depth of the inverted conical tooth inside the synchronizer sleeve of the workpiece to be processed, and the thickness LD of the clamping part (1) ranges from 2.5 to 3.2 mm.

6. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 1, characterized in that, The length of the clamping part (1) satisfies the following relationship: Le = (L1 + 0.4~0.6mm) + Lt; Where Le is the length of the clamping part (1), L1 is the effective length of the inverted conical tooth inside the synchronizer sleeve to be processed, and Lt is the axial length of the secondary cutting edge.

7. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 1, characterized in that, The first rake face (3), the second rake face (4), the first clearance face (5), and the second clearance face (6) are all non-developable ruled surfaces.

8. The double-edged cutting blade with a large rake angle for machining the inner groove of the inverted conical teeth inside the synchronizer sleeve as described in claim 1, characterized in that, The rear end face and bottom face of the clamping part (1) are also provided with a chamfer (7) to prevent misalignment.

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