A thread forming machining method considering positioning and heavy load transmission

Abstract

This invention relates to a method for machining formed threads that balances positioning and heavy load transfer, belonging to the field of machining. It includes: selecting a cutting tool, roughing, finishing the major diameter of the thread, finishing the working surface of the thread, and finishing the non-working surface of the thread. In finishing the major diameter of the thread, the tooth profile is widened on one side along the feed direction, which facilitates chip removal and reduces cutting deformation force. When finishing both sides of the thread profile, a layered cutting method is used, ensuring that the cutting edge of the tool maintains the same contact area with the machined tooth side, which does not increase with the depth of cut. This effectively disperses cutting resistance, solves the problem of increased impact force with deeper cuts, and reliably guarantees the quality of the thread machining.

Description

Technical Field

[0001] This invention belongs to the field of machining, specifically relating to a method for machining formed threads that takes into account both positioning and heavy load transmission. Background Technology

[0002] In the manufacturing of weaponry and heavy machinery, transmission components require high positioning accuracy and must withstand instantaneous impacts of tens or even hundreds of tons during operation. This high-impact, heavy-load environment places higher demands on the machining quality of transmission threads. Because the material used for this thread machining has a strength of σ... r0.1 For threads with a strength above 1100MPa, and which are non-standard formed threads with a trapezoidal tooth profile, asymmetrical angles on both sides of the tooth groove, and large pitch and helix angle, the current method involves rough machining to create the thread profile, followed by finishing by increasing the diameter and depth of cut, alternating between left and right sides, until the finished product is achieved. During this process, because both cutting edges of the tool are in contact with the material being removed, the large depth of cut leads to concentrated cutting stress and high cutting resistance, easily causing tool chatter. This makes it difficult to guarantee the surface roughness and accuracy of the thread profile. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] The technical problem to be solved by the present invention is to provide a forming thread machining method that takes into account both positioning and heavy load transmission, in order to solve the problem that the cutting resistance generated by the cutting edge of the tool in full contact with the material to be removed during the finishing process of forming threads under high impact and heavy load transmission is large, which makes it difficult to ensure the stable surface roughness and accuracy of the thread profile.

[0005] (II) Technical Solution

[0006] To solve the above-mentioned technical problems, the present invention provides a method for machining formed threads that takes into account both positioning and heavy load transmission, comprising the following steps:

[0007] S1: Adjust the lathe lead screw according to the part design requirements, select the tool with the corresponding cutting angle according to the thread profile parameters, and complete the tool setting;

[0008] S2: Using the non-working surface of the thread as a reference, feed the tool perpendicular to the thread axis. The feed rate for the first cut is set to t1, the feed rate for the second cut is set to (0.6-0.8)t1, and the feed rate for the nth cut is set to... Continue machining until a finishing allowance is left on the major diameter of the thread;

[0009] S3: Using the non-working surface of the thread as a reference, the feed is made laterally along the tooth profile angle of the non-working surface. The feed rate is set to a constant t2. The cutting feed is performed layer by layer until the major diameter of the thread reaches the finished size.

[0010] S4: Using the thread working surface as a reference, the tool is fed laterally along the tooth profile angle of the working surface. Combined with the tooth height layered feeding method, the depth of the first cut is (1 / 4 to 1 / 3)h, the depth of the second cut is 2(1 / 4 to 1 / 3)h, and so on, until the nth cut is made when the cutting edge of the tool contacts the full tooth height of the thread, thus completing the finishing of the working surface.

[0011] S5: Using the non-working surface of the thread as a reference, the tool is fed laterally along the tooth profile angle of the non-working surface. Combined with the tooth height layered feed method, the first layer of machining of the non-working surface is completed. The tool moves a certain distance to the non-working surface and repeats the first layer machining method until the thread tooth profile width reaches the finished size.

[0012] In step 2, when the machining allowance for the thread profile width is large, the tool moves a certain distance in the feed direction, feeds laterally along the thread profile angle of the working surface, and repeatedly feeds in the direction perpendicular to the thread axis until the thread profile width leaves a finishing allowance.

[0013] In step S3, when the width of the bottom of the tooth profile is large, the tool moves a certain distance along the cutting direction and repeats the lateral feed at the non-working face tooth profile angle until the major diameter of the thread reaches the finished size on the width of the rough-machined tooth profile.

[0014] In step S4, h represents the tooth height.

[0015] (III) Beneficial Effects

[0016] Compared with the prior art, the present invention has the following beneficial effects: when finishing the major diameter of the thread, the tooth profile is widened on one side in the direction of the feed, which is conducive to the discharge of chips and the cutting deformation force is small; when finishing both sides of the thread profile, the method of layered cutting of tooth height is adopted, and the cutting edge of the tool always maintains the same contact area with the side of the tooth being machined, which does not increase with the increase of the depth of cut, effectively dispersing the cutting resistance, solving the problem that the deeper the cut, the greater the impact force, and reliably ensuring the machining quality of the thread. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a formed thread structure;

[0018] Figure 2 This is a schematic diagram of a roughing method for forming threads;

[0019] Figure 3 This is a schematic diagram of the finishing process on both sides of the formed thread profile. Detailed Implementation

[0020] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0021] This embodiment provides a method for machining formed threads that takes into account both positioning and heavy load transfer, including the following steps:

[0022] S1: Adjust the lathe lead screw according to the part design requirements, select the tool with the corresponding cutting angle according to the thread profile parameters, and complete the tool setting;

[0023] S2: Using the non-working surface of the thread as a reference, feed the tool perpendicular to the thread axis. The feed rate for the first cut is set to t1, the feed rate for the second cut is set to (0.6-0.8)t1, and the feed rate for the nth cut is set to... Continue machining until a finishing allowance is left on the major diameter of the thread;

[0024] S3: Using the non-working surface of the thread as a reference, the feed is made laterally along the tooth profile angle of the non-working surface. The feed rate is set to a constant t2. The cutting feed is performed layer by layer until the major diameter of the thread reaches the finished size.

[0025] S4: Using the thread working surface as a reference, the tool is fed laterally along the tooth profile angle of the working surface. Combined with the tooth height layered feeding method, the depth of the first cut is (1 / 4 to 1 / 3)h, the depth of the second cut is 2(1 / 4 to 1 / 3)h, and so on, until the nth cut is made when the cutting edge of the tool contacts the full tooth height of the thread, thus completing the finishing of the working surface.

[0026] S5: Using the non-working surface of the thread as a reference, the tool is fed laterally along the tooth profile angle of the non-working surface. Combined with the tooth height layered feed method, the first layer of machining of the non-working surface is completed. The tool moves a certain distance to the non-working surface and repeats the first layer machining method until the thread tooth profile width reaches the finished size.

[0027] In step 2, when the machining allowance for the thread profile width is large, the tool moves a certain distance in the feed direction, feeds laterally along the thread profile angle of the working surface, and repeatedly feeds in the direction perpendicular to the thread axis until the thread profile width leaves a finishing allowance.

[0028] In step S3, when the width of the bottom of the tooth profile is large, the tool moves a certain distance along the cutting direction and repeats the lateral feed at the non-working face tooth profile angle until the major diameter of the thread reaches the finished size on the width of the rough-machined tooth profile.

[0029] In step S4, h represents the tooth height.

[0030] Example 1:

[0031] This embodiment includes the following steps:

[0032] S1. Preparatory work before machining: Adjust the lathe lead screw according to the pitch P of the thread to be machined to make it match; select a tool with a suitable cutting angle according to the thread profile parameters, wherein the tool tip width is smaller than the thread profile groove width, the tool front and rear angles are consistent with the angles on both sides of the thread profile, and complete the tool setting.

[0033] S2. Roughing: Using the non-working surface of the thread as a reference, feed the tool perpendicular to the thread axis. The feed rate for the first pass is 0.5mm, the feed rate for the second pass is 0.4mm, and the feed rate for the third pass is 0.3mm, until a finishing allowance is left on the major diameter of the thread. Then, using a one-sided widening method, move the tool 0.5-0.8mm along the feed direction and repeat the feed perpendicular to the thread axis until a finishing allowance of 0.2-0.3mm is left on each side of the thread profile width.

[0034] S3. Finishing the major diameter of the thread: Using the non-working surface of the thread as a reference, feed laterally along the tooth profile angle of the non-working surface, with each feed amount being 0.05mm. Cut layer by layer until the major diameter of the thread reaches the finished size φD. Move the tool 0.1-0.2mm along the feed direction and repeat the above steps until the major diameter of the thread reaches the finished size φD on the tooth profile width obtained from roughing.

[0035] S4. Finishing the threaded working surface: Using the threaded working surface as a reference, the tool is laterally fed along the tooth profile angle of the working surface, combined with a layered feed method based on the tooth height. The depth of the first cut is... The second cut depth is... During the third cut, the cutting edge of the tool makes full contact with the thread, completing the finishing of the working surface.

[0036] S5. Finishing the non-working surface of the thread: Using the non-working surface of the thread as a reference, the tool is fed laterally along the tooth profile angle of the non-working surface. Combined with the tooth height layered feed method, the first layer of machining of the non-working surface is completed. The tool moves 0.1-0.2mm towards the non-working surface and the first layer machining method is repeated until the thread root width reaches the finished size t.

[0037] The parts are made of high-quality alloy steel with a performance of Q1180Mpa. The thread minor diameter is φd, the thread major diameter is φD, the thread pitch is P, and the root width is t. The working face angle is α, and the non-working face angle is β.

[0038] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for machining formed threads that balances positioning and heavy load transfer, characterized in that, Includes the following steps: S1: Adjust the lathe lead screw according to the part design requirements, select the tool with the corresponding cutting angle according to the thread profile parameters, and complete the tool setting; S2: Using the non-working surface of the thread as a reference, feed the tool perpendicular to the thread axis. The first feed rate is set to... The feed rate for the second cut is set to (0.6-0.8). The feed rate for the nth cut is set to... Continue machining until a finishing allowance is left on the major diameter of the thread; S3: Using the non-working surface of the thread as a reference, the feed rate is set to a constant value along the thread profile angle of the non-working surface. The cutting feed is performed layer by layer until the major diameter of the thread reaches the finished size. S4: Using the thread working surface as a reference, the tool is fed laterally along the tooth profile angle of the working surface. Combined with the tooth height layered feeding method, the depth of the first cut is (1 / 4 to 1 / 3)h, the depth of the second cut is 2(1 / 4 to 1 / 3)h, and so on, until the nth cut, when the cutting edge of the tool contacts the full tooth height of the thread, the working surface is finished. S5: Using the non-working surface of the thread as a reference, the tool is fed laterally along the tooth profile angle of the non-working surface. Combined with the tooth height layered feed method, the first layer of machining of the non-working surface is completed. The tool moves a certain distance to the non-working surface and the first layer machining method is repeated until the thread tooth profile width reaches the finished size. In step 2, when the machining allowance for the thread profile width is large, the tool moves a certain distance in the feed direction, feeds laterally along the thread profile angle of the working surface, and repeatedly feeds in the direction perpendicular to the thread axis until the thread profile width leaves a finishing allowance. In step S3, when the width of the bottom of the tooth profile is large, the tool moves a certain distance along the tool path and repeats the lateral feed at the non-working face tooth profile angle until the major diameter of the thread reaches the finished size on the width of the rough-machined tooth profile. In step S4, h represents the tooth height.

Images