A method for machining rectangular slots using a gear shaping machine

Abstract

The application discloses a method for machining a rectangular groove by using a gear shaping machine, S1, a cutter and a workpiece are located at an initial position, a center line of the cutter is coincident with a design center line of the rectangular groove on the workpiece; S2, the cutter is retreated after cutting to a groove bottom of the rectangular groove; S3, the cutter and the workpiece are forwardly rotated by an angle α, α=tan ‑1 (R 槽 Sinθ 槽 ‑R 刀 Sinθ 刀 ) / (R 槽 Cosθ 槽 ‑R 刀 Cosθ 刀 ); S4, the cutter is cut, an amount of feed compensation is △X, △X= (‑1)‑‑(‑1)+, and the cutter is retreated after machining is completed; S5, the cutter and the workpiece return to the initial position, and the cutter and the workpiece are reversely rotated by the angle α; and S6, the cutter is cut, and an amount of feed is same as that in S4. The application is favorable for reducing a force area in a cutting direction, effectively improving a chip removal capacity, reducing a cutting force, improving a cutter life and universality.

Description

Technical Field

[0001] This invention relates to a keyway machining method, and more particularly to a method for machining rectangular grooves using a gear shaper. Background Technology

[0002] Currently, internal and external rectangular grooves are typically machined using form tools. Each groove size requires a dedicated tool, resulting in poor versatility and high processing costs. With the continuous upgrading of gear materials, their hardness and toughness have significantly increased, making this process unsuitable for machining such materials. For example, 15Cr14Co12Mo5Ni has a hardness of HRC53. When machining with form tools, the high hardness makes it prone to tool deflection. During tool retraction, the tool is squeezed by the workpiece, and the tool is subjected to force on three sides, leading to poor chip removal performance and a high risk of tool breakage. This phenomenon is more pronounced with wider rectangular grooves (for wider internal rectangular grooves, the form tool has difficulty in chip removal and is subjected to high force, making tool breakage highly likely). In-house machining of internal rectangular grooves using carbide-coated tools can only machine one keyway per tool, or tool breakage occurs during machining. Using a milling-turning machine with milling cutters results in damage to the machine's power conversion head after machining five parts, leading to poor economic efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for machining rectangular grooves using a gear shaper, which is beneficial to reducing the force area in the cutting direction, effectively improving chip removal capacity, reducing cutting force, improving tool life and versatility.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for machining rectangular grooves using a gear shaper includes the following steps: S1. The tool and workpiece are in the initial position, and the centerline of the tool coincides with the design centerline of the rectangular groove on the workpiece. S2. The tool cuts to the bottom of the rectangular groove, then retracts the tool; S3, the forward rotation angle α between the tool and the workpiece. α=tan -1 (R) 槽 Sinθ 槽 -R 刀 Sinθ 刀 ) / (R 槽 Cosθ 槽 -R 刀 Cosθ 刀 ); S4, tool cutting, the tool feed compensation amount compared to S2 is △X, △X= ( -1)- - ( -1)+ , After machining is completed, the tool is retracted; S5. The tool and workpiece return to their initial positions, and then rotate in the opposite direction by an angle α. S6, tool cutting, the tool feed rate is the same as S4; Among them, R 槽 R is the radius of rotation of the circular arc at the location of the rectangular groove. 刀 K is the radius of rotation of the arc at the location of the blade tip. 槽 K is the width of the rectangular groove. 刀 θ is the width of the cutting tool. 槽 θ is half the angle formed by the groove width and the arc at the bottom of the groove. 刀 It is the angle between the perpendicular line connecting the two blade tips and the line connecting the blade tip to the center of the tool.

[0005] As a further improvement to the above technical solution: K 槽 ≤3K 刀 .

[0006] A method for machining rectangular grooves using a gear shaper includes the following steps: S1. The tool and workpiece are in the initial position, and the centerline of the tool coincides with the design centerline of the rectangular groove on the workpiece. S2. The tool cuts to the bottom of the rectangular groove, then retracts the tool; S3.1, the forward rotation angle α between the tool and the workpiece. α=tan -1 (R) 槽 Sinθ 槽 -R 刀 Sinθ 刀 ) / (R 槽 Cosθ 槽 -R 刀 Cosθ 刀 ); S3.2, Tool cutting, the tool feed compensation amount compared to S2 is △X, △X= ( -1)- - ( -1)+ , After machining is completed, the tool is retracted; S3.3, The tool and workpiece return to their initial positions, and then rotate in the opposite direction by an angle α; S3.4, Tool cutting: The tool feed rate is the same as in S3.2. After machining is completed, the tool retracts. S3.5, The tool and workpiece return to their initial positions; S4. Machining using the generating method: Groove width K 槽 Entering the linear change stage, denoted as ΔK, the tool and workpiece maintain a rotation angle Δ Similarly, with the control step ΔK as a condition, calculate Δ The final groove width is achieved by changing the angle. Among them, R 槽 R is the radius of rotation of the circular arc at the location of the rectangular groove. 刀 K is the radius of rotation of the arc at the location of the blade tip. 槽 K is the width of the rectangular groove. 刀 θ is the width of the cutting tool. 槽 θ is half the angle formed by the groove width and the arc at the bottom of the groove. 刀 It is the angle between the perpendicular line connecting the two blade tips and the line connecting the blade tip to the center of the tool.

[0007] As a further improvement to the above technical solution: Linearly varying slot width K 槽2 =K 槽+ △K, R 槽2 = , △α= , △X2=R 槽2 Cos(θ) 槽2 -α+△α)- R 槽 Cosθ 槽2 - R 刀 Cos(θ) 刀 -α+△α)+ R 刀 Cosθ 刀 -(R) 槽 Cos(θ) 槽 -α)-R 槽 Cosθ 槽 -R 刀 Cos(θ) 刀 -α)+R 刀 Cosθ 刀 ); Where D is the center distance of the bottom of the trench.

[0008] K 槽 >3K 刀 .

[0009] Compared with the prior art, the advantages of the present invention are as follows: This invention discloses a method for machining rectangular grooves using a gear shaper. A tool narrower than the groove width is used on the gear shaper. First, the tool's centerline is aligned with the groove's centerline, and a straight cut is made to create a groove of the corresponding width. Then, the tool and workpiece are simultaneously rotated forward and backward by corresponding angles, and the feed rate is adjusted to be higher than during the straight cut, ensuring a flat groove bottom. This yields a rectangular groove of the designed dimensions. Cutting the groove at the center first creates a clearance for the tool retraction, and then widening the groove reduces the force-bearing area in the cutting direction, effectively improving chip removal, reducing cutting force, and extending tool life. It also possesses versatility, solving the problems of narrow-tool, wide-groove machining on gear shapers and tool retraction interference during rectangular groove machining. Its cost-reduction effect is particularly significant in research and production.

[0010] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the geometric parameters of the cutting tool in this invention. Figure 2 This is a schematic diagram of the geometric parameters of the rectangular groove involved in the present invention.

[0012] Figure 3 This is a schematic diagram of the rotation angle and feed compensation amount of the present invention.

[0013] Figure 4 This is a schematic diagram of the process of machining rectangular grooves using a gear shaper according to the present invention.

[0014] Figure 5 This is a cross-sectional structural schematic diagram of the workpiece involved in the present invention.

[0015] Figure 6 yes Figure 5 A-direction view.

[0016] The labels in the diagram represent: 1. Cutting tool; 2. Workpiece; 21. Rectangular groove. Detailed Implementation

[0017] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0019] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figures 1 to 4 This invention illustrates an embodiment of a method for machining rectangular grooves using a gear shaper. The invention employs a multi-segment straight-cutting method or a method of first straight-cutting and then generating the groove.

[0022] When cutting straight, the process follows the standard slotting procedure. The gear shaper's feed action generally includes: the gear shaper cutter inserts downwards to the limit position – retraction (usually 0.05-3mm) – the gear shaper cutter moves upwards – the gear shaper cutter feeds in. The straight cut creates a groove in the center of the rectangular slot 21, primarily to create a retraction clearance.

[0023] The generating process consists of two parts: ① When the width of the rectangular groove 21 is no more than 3 times the tool width, a straight cut plus two-cut angled straight cut is used; ② When the width of the rectangular groove 21 is greater than 3 times the tool width, a straight cut plus two-cut angled straight cut is used, followed by generating and inserting, or multiple angled straight cuts to complete the machining. The main function of the oblique straight cut and generating process is to expand the groove width.

[0024] When the groove width is no greater than 3 times the tool width, the angle of the machining tilt angle is demonstrated as follows: R 刀 sinθ 刀 -R 刀 sinθ 刀 cosα+R 刀 sinαcosθ 刀 =R 槽 sinθ 槽 -R 槽 sinθ槽 cosα + R 槽 sinαcosθ 槽 - K 槽 + K 刀 ; R 槽 Sinθ 槽 Cosα - R 刀 Sinθ 刀 Cosα + R 刀 SinαCosθ 刀 - R 槽 SinαCosθ 槽 = R 槽 Sinθ 槽 - K 槽 + K 刀 - R 刀 Sinθ 刀 ; Cosα(R 槽 Sinθ 槽- - R 刀 Sinθ 刀 ) + Sinα(R 刀 Cosθ 刀 - R 槽 Cosθ 槽 ) = R 槽 Sinθ 槽 - K 槽 + K 刀 - R 刀 Sinθ 刀 ; Also: R 槽 Sinθ 槽 - K 槽 + K 刀 - R 刀 Sinθ 刀 = 0; Cosα(R 槽 Sinθ<00001​​​​​​​​​​​​​​​槽 Cosθ 槽 -R 刀 Cosθ 刀 ) / (R 槽 Sinθ 槽- -R 刀 Sinθ 刀 ); tanα=(R 槽 Sinθ 槽- -R 刀 Sinθ 刀 ) / (R 槽 Cosθ 槽 -R 刀 Cosθ 刀 ) ; We get: α = tan -1 (R) 槽 Sinθ 槽 -R 刀 Sinθ 刀 ) / (R 槽 Cosθ 槽 -R 刀 Cosθ 刀 ) ; in, α is the angle of the tool 1 tilt and the angle of the workpiece 2 rotation. K 槽 The width of rectangular groove 21 K 刀 The width of tool 1 R 槽 R is the radius of rotation of the circular arc at the location of the rectangular groove 21. 槽 D is the center distance of the tank bottom, that is, the distance from the center of the tank bottom to the center of rotation. R 刀 R is the radius of rotation of the arc at the location of the blade tip. 刀 = d is the center distance between the cutting edges, which is the perpendicular distance between the line connecting the two cutting tips and the center of the cutting tool. θ 槽 It is half the angle formed by the groove width and the arc at the bottom of the groove. θ 刀 It is the angle between the perpendicular line connecting the two blade tips and the line connecting the blade tip to the center of the tool 1.

[0025] Further optimization: α= .

[0026] Let the X-axis feed compensation be ΔX: The change in chord height after the tool rotates is: R 刀 -R刀 Cosθ 刀 -(R) 刀 -R 刀 Cos(θ) 刀 -α)) =R 刀 Cos(θ) 刀 -α)-R 刀 Cosθ 刀 = ( -1)+ , Similarly, the change in chord height after the groove rotates is: R 槽 Cos(θ) 槽 -α)-R 槽 Cosθ 槽 = ( -1)-

[0027] Then: △X=R 槽 Cos(θ) 槽 -α)-R 槽 Cosθ 槽 -R 刀 Cos(θ) 刀 -α)+R 刀 Cosθ 刀 = ( -1)- - ( -1)+ .

[0028] When the groove width is greater than 3 times the tool width, multi-segment machining can be used to achieve the final groove width, or the generating method can be used for machining.

[0029] For multi-segment processing, the real-time groove width of each segment needs to be calculated to ensure that the bottom of the groove can be level. The calculation method is the same as the method described above.

[0030] When the machining process enters the generating state, the groove width K is at this time. 槽 Entering the linear change stage, denoted as ΔK, the synchronous machining of the cornering tool and workpiece requires maintaining the same rotation angle Δα to meet machining requirements. Typically, Δα is calculated based on the control step ΔK, and the groove width is changed by varying the angle, thus machining the final groove width K. 槽 .

[0031] Linearly varying slot width: K 槽2 =K 槽+ △K, R槽2 = , △α= , △X2=R 槽2 Cos(θ) 槽2 -α+△α)- R 槽 Cosθ 槽2 - R 刀 Cos(θ) 刀 -α+△α)+ R 刀 Cosθ 刀 -(R) 槽 Cos(θ) 槽 -α)-R 槽 Cosθ 槽 -R 刀 Cos(θ) 刀 -α)+R 刀 Cosθ 刀 ).

[0032] Determining the maximum slot width: Without considering tool structure interference, the maximum slot width is the value when the tool rotates 90°: K 槽 =2d (i.e., twice the center distance of the tool edge), and the other maximum groove widths can be determined based on the interference caused by the tool structure.

[0033] See Figure 5 and 6 The workpiece material is 16CrNiWMoNv, with a hardness of HRC48-53. The rectangular groove is 11mm wide and 5mm deep. When machining with a forming tool, the tool chipps when machining to a depth of 3-4mm. Using the machining method of this invention, a total of 7 pieces can be machined to satisfactory quality. This demonstrates that the method of this invention has the following technical effects: 1) It can effectively avoid tool retraction interference during the machining of rectangular grooves; 2) Solve the problem of tool breakage caused by excessive force on the tool; 3) It can use narrow cutters to machine wide grooves, improving the versatility of cutting tools, and has a significant cost reduction effect, especially in scientific research and production.

[0034] The specific calculation method and processing procedure are as follows: Selecting existing tool 1, the measured width is K. 刀 =5mm, tool edge center distance d=17.8256; calculated, tool radius R 刀 =18mm, groove width K 槽 =11.1mm, groove center distance D=85.95mm; calculated R 槽 =86.129mm During angled machining, both the tool and the workpiece deflect by an angle simultaneously. α= , The calculated result is 2.57451723°, and the specific value will be determined according to the design requirements.

[0035] X-axis feed compensation: △X= ( -1)- - ( -1)+ , The calculation result is 0.068240331, and the specific value will be determined according to the design requirements.

[0036] During machining, first ensure the centerline of tool 1 is on the centerline of the groove width, and cut a 5mm wide groove using a straight cut. Then, rotate the tool counterclockwise and clockwise by 2.57451723° respectively (theoretical calculation value, specific value determined according to design requirements). Simultaneously, the feed rate should be 0.068240331mm greater than during the straight cut (theoretical calculation value, specific value determined according to design requirements) to obtain the rectangular groove 21 required by the design. A total of 15 rectangular grooves 21 are evenly distributed on the inner hole of workpiece 2, with an angular interval of 360° ÷ 15 = 24°. After rotating the workpiece 24°, repeat the above steps to machine the second rectangular groove 21, and so on for the remaining rectangular grooves 21.

[0037] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A method for machining rectangular grooves using a gear shaper, characterized in that: Including steps, S1, the tool (1) and the workpiece (2) are in the initial position, and the center line of the tool (1) coincides with the design center line of the rectangular groove (21) on the workpiece (2); S2. The tool (1) cuts to the bottom of the rectangular groove (21) and then retracts the tool; S3, the positive rotation angle α of the tool (1) and the workpiece (2), α=tan -1 (R) 槽 Sinth 槽 -R 刀 Sinth 刀 ) / (R 槽 Cosθ 槽 -R 刀 Cosθ 刀 ); S4, cutting tool (1), the feed compensation of tool (1) compared to S2 is △X, △X= （ -1）- - （ -1）+ ， After machining is completed, the cutting tool (1) is retracted; S5, the tool (1) and workpiece (2) return to their initial positions and then rotate in the opposite direction by an angle α; S6, the cutting tool (1) cuts, and the feed rate of the cutting tool (1) is the same as that of S4; Among them, R 槽 R is the radius of rotation of the circular arc at the location of the rectangular groove (21). 刀 K is the radius of rotation of the arc at the location of the blade tip. 槽 K is the width of the rectangular groove (21). 刀 θ is the width of the cutting tool. 槽 θ is half the angle formed by the groove width and the arc at the bottom of the groove. 刀 The angle between the perpendicular line connecting the two blade tips and the line connecting the blade tip to the center of the tool (1).

2. The method for machining rectangular grooves using a gear shaper according to claim 1, characterized in that: K 槽 ≤3K 刀 。 3. A method for machining rectangular grooves using a gear shaper, characterized in that: Including steps, S1, the tool (1) and the workpiece (2) are in the initial position, and the center line of the tool (1) coincides with the design center line of the rectangular groove (21) on the workpiece (2); S2. The tool (1) cuts to the bottom of the rectangular groove (21) and then retracts the tool; S3.1, the positive rotation angle α of the tool (1) and the workpiece (2), α=tan -1 (R) 槽 Sinth 槽 -R 刀 Sinth 刀 ) / (R 槽 Cosθ 槽 -R 刀 Cosθ 刀 ); S3.2, cutting tool (1), the feed compensation of tool (1) compared to S2 is △X, △X= （ -1）- - （ -1）+ ， After machining is completed, the cutting tool (1) is retracted; S3.3, the tool (1) and workpiece (2) return to their initial positions and then rotate in the opposite direction by an angle α; S3.4, the cutting tool (1) cuts, the feed rate of the cutting tool (1) is the same as that of S3.2, and after the machining is completed, the cutting tool (1) retracts; S3.5, the tool (1) and workpiece (2) return to their initial positions; S4. Machining using the generating method: Groove width K 槽 Entering the linear change stage, let it be △K, the tool (1) and the workpiece (2) maintain a rotation angle △ Similarly, with the control step ΔK as a condition, calculate Δ The final groove width is achieved by changing the angle. Among them, R 槽 R is the radius of rotation of the circular arc at the location of the rectangular groove (21). 刀 K is the radius of rotation of the arc at the location of the blade tip. 槽 K is the width of the rectangular groove (21). 刀 θ is the width of the cutting tool. 槽 θ is half the angle formed by the groove width and the arc at the bottom of the groove. 刀 The angle between the perpendicular line connecting the two blade tips and the line connecting the blade tip to the center of the tool (1).

4. The method for machining rectangular grooves using a gear shaper according to claim 3, characterized in that: Linearly varying slot width K 槽2 =K 槽+ △K, R 槽2 = ， △α= ， △X2=R 槽2 Cos (θ) 槽2 (-α+△α)- R 槽 Cosθ 槽2 - R 刀 Cos (θ) 刀 -α+△α)+ R 刀 Cosθ 刀 -(R) 槽 Cos (θ) 槽 -a)-R 槽 Cosθ 槽 -R 刀 Cos (θ) 刀 -a)+R 刀 Cosθ 刀 ); Where D is the center distance of the bottom of the trench.

5. The method for machining rectangular grooves using a gear shaper according to claim 3, characterized in that: K 槽 >3K 刀 。

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