A large pitch arc thread profiling method and device

Abstract

The present invention relates to a method and device for profiling large-pitch circular arc threads, and belongs to the technical field of thread processing. The present invention first uses an arc turning tool to perform rough processing along the radial feed direction of the turning tool, processing from a first position to a second position, and then uses the second position as the starting point of the arc turning tool center position when processing the tooth side. The tool tip position is controlled to be spaced at intervals of the required feed amount in the radial feed direction and at intervals of the product of the required feed amount and the tangent value of half the tooth profile angle in the axial direction. The tooth side is layered according to the tool tip offset coordinates of each layer, and after the tooth side processing is completed, the arc tooth bottom is processed using the arc turning tool. It can be seen that the present invention can use the arc turning tool to realize the processing of the tooth side, so that when processing the tooth #imgabs0# and tooth side of the circular arc thread, only one turning tool can be used, and there is no need to change the tool and set the tool in the middle of the processing. This not only improves the processing efficiency, but also avoids the problem of poor precision caused by tool setting.

Description

Technical Field

[0001] The invention relates to a large-pitch circular arc thread profiling method and device, belonging to the technical field of thread processing. Background Art

[0002] Threaded connections are a common connection method. Circular threads offer significant advantages over conventional metric and MJ threads in terms of manufacturing, structural strength, and fatigue resistance. A Chinese utility model patent, authorized with publication number CN209818480U, discloses a high-strength circular thread connection pair. This pair utilizes a circular thread profile, with surface contact between the internal and external threads, ensuring uniform force distribution. This effectively reduces stress concentration when the threads are loaded, and provides excellent fatigue resistance. The patent discloses two circular thread structures with major thread diameters of 42 and 48 mm, and pitches of 6.35 and 8.5 mm, respectively. The Chinese patent with authorization announcement number CN116877555B discloses a double-ended stud for connecting the root of a wind turbine blade and a processing method thereof. The external thread of the threaded section of the double-ended stud is an arc thread. The nominal diameter of the arc thread dnominal = 36mm~40mm, the pitch of the arc thread Pr = (0.153~0.192)dnominal, the tooth height hr of the arc thread = (0.37~0.44)Pr, and the minor diameter of the arc thread d1r = dnominal-0.8746Pr.

[0003] As can be seen from the above, the tooth profile of the arc thread is a symmetrical structure, including two symmetrical tooth tops, tooth sides composed of edge lines, and an arc tooth bottom. In traditional technology, trapezoidal turning tools are generally used to process the tooth sides of arc threads. When using arc turning tools to process the arc tooth bottom of arc threads, the tool needs to be changed in the middle of processing. There may be errors when aligning the arc turning tool and the trapezoidal turning tool, resulting in obvious tool marks on the tooth profile surface. In addition, when using a trapezoidal turning tool to process the tooth side, since the tooth profile angle accuracy of the tooth side depends on the clamping accuracy of the trapezoidal tool, in order to ensure the tooth side processing accuracy, a long tool alignment time is required, resulting in low arc thread processing efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a large pitch arc thread profiling processing method and device to solve the problem that the current large pitch arc thread processing using an arc turning tool requires changing the tool midway to process the tooth side, resulting in obvious tool marks, low processing efficiency and poor precision.

[0005] In order to solve the above technical problems, the present invention provides a large pitch arc thread profiling method, which comprises:

[0006] 1) machining from a first position to a second position along a radial feed direction of the turning tool using an arc turning tool, wherein the second position is the center position of the tool arc when the intersection of the tool arc radius and the tooth flank and tooth top axes is tangent in the tooth flank direction, and the first position is the center position of the tool arc when the second position is translated to the point where the tool arc is tangent to the tooth top axis;

[0007] 2) Using the second position as the starting point of the arc turning tool center position when machining the tooth flank, control the tool tip position in the radial feed direction to be spaced at intervals of the required feed amount and in the axial direction to be spaced at intervals of the required feed amount multiplied by half of the tangent value of the tooth profile angle, and use the second position to determine the tool tip offset coordinates of each layer when machining the tooth flank. The tooth flank is machined in layers according to the tool tip offset coordinates of each layer, with the axial direction being the direction of the lathe rotation axis;

[0008] 3) After the tooth side processing is completed, use the arc turning tool to process the arc tooth bottom.

[0009] Furthermore, the tool tip radius of the arc turning tool needs to meet the following conditions:

[0010]

[0011] Among them, R 底 is the tooth bottom radius, R 刀 W is the tool tip radius of the arc turning tool, 顶 is the tooth top width, and θ is the tooth profile angle.

[0012] Furthermore, each cut in step 1) is processed according to a set feed amount, which is determined based on the maximum feed amount and the processing depth. The processing depth is the distance between the first position and the second position, which is the distance in the radial feed direction of the turning tool. The calculation formula used is:

[0013]

[0014] where X A is the processing depth, R 刀 is the tool nose radius of the arc turning tool, and θ is the tooth angle.

[0015] Furthermore, in step 1), the processing method of each layer is adopted, and each layer has two cuts. The offset coordinates of the tool tip position of each layer relative to the origin O are (X n , Z i ) and (X n , -Z i ), X n Indicates the tool tip position offset relative to the origin O in the radial feed direction of the turning tool during the nth layer machining, Z iIndicates the tool tip position offset relative to the origin O in the direction of the machine tool rotation axis during each layer processing. The origin O is the intersection of the tooth top and the tooth profile symmetry axis. n and Z i The calculation formula used is:

[0016] X n =nΔX 设定

[0017]

[0018] where R 刀 W is the tool tip radius of the arc turning tool, 顶 is the tooth crest width.

[0019] Furthermore, the required feed amount in step 2) is determined based on the maximum feed amount, and the required feed amount is less than or equal to the maximum feed amount. The determined maximum feed amount is:

[0020]

[0021] where ΔX 牙侧max R is the maximum feed amount along the radial feed direction of the turning tool during tooth side machining. z is the required roughness, R 刀 is the tool nose radius of the arc turning tool, and θ is the tooth angle.

[0022] Furthermore, the required feed amount is:

[0023]

[0024] where ΔX 牙侧 is the required feed amount, Indicates rounding up, H 侧 is the tooth flank height, and m is the number of layers required for machining the tooth flank.

[0025] Furthermore, in step 2), the tooth side is processed in layers according to the tool tip offset coordinates of each layer, and the tool side is processed by a tool-driving method for each layer. Each layer has two tools, and the tool tip offset coordinates of each layer relative to the origin O are (X j , Z j ) and (X j , -Z j ), X j Indicates the offset of the turning tool in the radial feed direction relative to the origin O when machining the jth layer of the tooth side, Z j It represents the offset relative to the origin O in the direction of the machine tool rotation axis when machining the jth layer of the tooth side. The origin O is the intersection of the tooth top and the tooth profile symmetry axis. j and Z j The calculation formula used is:

[0026] X j =X A +jΔX 牙侧

[0027]

[0028] where X A is the processing depth, ΔX 牙侧 is the required feed amount, and θ is the tooth profile angle.

[0029] Furthermore, in step 3), the arc tooth bottom is processed according to the tool rotation angle and offset coordinates of each cut when the arc turning tool moves according to the set step angle, until the tool rotation angle is Rotate to θ is the tooth angle.

[0030] Furthermore, the step angle set in step 3) is determined based on the tool tip radius, tooth bottom arc radius and surface roughness of the tool, and the calculation formula used is:

[0031]

[0032] Among them, Δβ is the set step angle, R 刀 is the tool tip radius, R 底 R is the radius of the tooth bottom arc, Z is the surface roughness.

[0033] The present invention also provides a large-pitch circular arc thread profiling processing device, comprising a processor, wherein the processor is used to execute computer program instructions to implement the large-pitch circular arc thread profiling processing method.

[0034] The beneficial effects of the present invention are as follows: as a pioneering invention, the present invention first uses an arc turning tool to perform rough processing along the radial feed direction of the turning tool, so that the center of the arc turning tool is processed from a first position to a second position, and then the second position is used as the starting point of the arc turning tool center position when processing the tooth side, and the tool tip position is controlled to be spaced at intervals of the required feed amount in the radial feed direction and at intervals of the product of the required feed amount and the tangent value of half the tooth profile angle in the axial direction, and the second position is used to determine the tool tip offset coordinates of each layer when processing the tooth side, and the tooth side is layered according to the tool tip offset coordinates of each layer; and after the tooth side processing is completed, the arc tooth bottom is processed using the arc turning tool. It can be seen that the present invention can use the arc turning tool to realize the processing of the tooth side, so that when processing the tooth bottom and tooth side of the arc thread, only one turning tool can be used, and there is no need to change the tool and set the tool in the middle of the processing, which not only improves the processing efficiency, but also avoids the problem of poor precision caused by tool setting. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the large pitch circular arc thread profiling method of the present invention;

[0036] Figure 2 This is a schematic diagram showing the principle of selecting the tool tip radius during large pitch arc thread profiling according to the present invention;

[0037] Figure 3 Schematic diagram of the first position and the second position during machining of large pitch arc threads according to the present invention;

[0038] Figure 4 This is a schematic diagram of the tool position for rough machining of large pitch arc threads according to the present invention;

[0039] Figure 5 Schematic diagram of tool position for machining the flank of large pitch arc thread according to the present invention;

[0040] Figure 6 Schematic diagram of the relationship between the roughness of the tooth side and the tool tip radius when machining the large pitch circular arc thread of the present invention;

[0041] Figure 7 This is a diagram showing the calculation principle of the maximum feed amount when machining the tooth flank of a large pitch circular arc thread according to the present invention;

[0042] Figure 8 This is a diagram showing the calculation principle of the present invention when performing flank layered feed processing on a large pitch circular arc thread;

[0043] Figure 9 This is a diagram showing the principle of calculating the step angle when processing the tooth bottom of a large pitch circular arc thread according to the present invention;

[0044] Figure 10 This is a schematic diagram of the processing principle of the large pitch arc thread bottom of the present invention;

[0045] Figure 11 It is a schematic diagram of the tool position for machining the tooth bottom of a large pitch circular arc thread according to the present invention. DETAILED DESCRIPTION

[0046] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0047] Embodiment of large pitch arc thread profiling method

[0048] The present invention first uses an arc turning tool to perform rough machining along the radial feed direction of the turning tool, machining from a first position to a second position, and then uses the second position as the starting point of the arc turning tool center position when machining the tooth flank. The tool tip position is controlled to be spaced at intervals of the required feed amount in the radial feed direction and at intervals of the product of the required feed amount and the tangent value of half the tooth profile angle in the axial direction. The second position is used to determine the tool tip offset coordinates of each layer when machining the tooth flank. The tooth flank is layered according to the tool tip offset coordinates of each layer. After the tooth flank machining is completed, the arc turning tool is used to machine the arc tooth bottom. Since during machining, when the arc turning tool gradually moves from the second position to the third position (i.e., O2), the arc surface of the arc turning tool is tangent to the tooth flank. When machining the bottom arc, the arc surface of the arc turning tool is tangent to the tooth bottom arc. Therefore, the entire machining process can be considered a profiling machining process.

[0049] The implementation process of this method is as follows Figure 1 shown.

[0050] In this embodiment, a nut with a large pitch arc thread is used as the object to be processed, wherein the arc thread tooth angle is θ and the tooth bottom radius is R 底 , tooth height is H, tooth top width is W 顶 , the maximum height of the profile, i.e. the roughness, is R Z , tooth bottom radius is R 底 , the radial retraction direction of the turning tool is taken as the positive direction of the X axis, that is, +X axis, the radial feed direction of the turning tool is taken as the negative direction of the X axis, that is, -X axis, the direction of the machine tool rotation axis (also called spindle) is taken as the Z axis, the negative direction of the angular momentum when the spindle rotates counterclockwise is -Z axis, the positive direction of the angular momentum when the spindle rotates clockwise is +Z axis, the intersection of the tooth top and the tooth profile symmetry axis is taken as the coordinate origin O, and the center of the tooth bottom arc is O 底 The X-direction offset of the center of the tooth bottom arc relative to point O is X 底 The offset of the center of the tooth bottom arc relative to point O in the Z direction is Z 底 , the processing of the present invention is described in detail below.

[0051] 1. Determine the tool parameters.

[0052] Since this embodiment needs to use an arc turning tool to process the entire arc thread, considering the processing efficiency, it is ensured that each layer can be processed with two cuts. Figure 2 As shown, the tool tip radius of the arc turning tool in this embodiment needs to meet the following conditions:

[0053]

[0054] Among them, R 底 is the tooth bottom radius, R 刀 W is the tool tip radius of the arc turning tool, 顶 is the tooth crest width.

[0055] As another embodiment, each layer can also be completed with multiple cuts. For example, each layer can be completed with k cuts. In this case, the tool tip radius of the arc turning tool needs to meet the following conditions:

[0056]

[0057] Considering the processing efficiency, each layer has a maximum of 3 cuts. If 3 cuts are used, the tool tip radius of the arc turning tool must meet the following conditions:

[0058]

[0059] 2. Use arc turning tool for rough machining.

[0060] 1) Determine the two positions during roughing

[0061] Based on the above parameters to be processed, determine the coordinate Z of the intersection of the tooth profile angle and the tooth top axis 顶 , Z 顶 is the tooth top width W 顶 Half of Figure 3 As shown, first make the tool arc radius R 刀 With Z 顶 Tangent in the tooth side direction, calculate the tool arc center at this time and record it as O2, which is the second position, then translate the determined tool arc center O2 along the X-axis direction until the tooth top arc is just tangent to the tooth top axis, and calculate the tool center at this time and record it as O1, which is the first position. Move the determined tool arc center O2 along the tooth side until it is just tangent to the tooth bottom arc, and calculate the tool center at this time and record it as O3. O3 is the stop position of the tool arc center during tooth side machining, where the distance between O2 and O3 in the radial feed direction of the turning tool is the tooth side height H 侧 The rough machining can be completed by using the arc turning tool to move the tool center from the first position to the second position along the radial feed direction of the turning tool (negative direction of the X axis).

[0062] 2) Determine the feed amount during rough machining

[0063] In this embodiment, the roughing process is performed from a first position to a second position along the radial feed direction of the turning tool according to a set feed amount, wherein the feed amount of each cut is equal to the set feed amount. The set feed amount is determined based on the maximum feed amount and the processing depth. The processing depth is the distance between the first position and the second position, which is the distance in the radial feed direction of the turning tool. The specific determination process is as follows:

[0064] According to the tool and processing experience, determine an initial maximum feed amount, and determine the number of roughing feed layers l based on the initial maximum feed amount:

[0065]

[0066] where X A is the processing depth, Indicates rounding up, such as Figure 4 As shown, the machining depth here is the distance between O1 and O2 in the X-axis direction, which can be calculated using the tooth angle and tool arc radius. The specific calculation formula is:

[0067]

[0068] The set feed amount is determined according to the number of feeds, so that the feed amount of each cut during processing is the same. The specific calculation of the set feed amount is:

[0069]

[0070] During the entire roughing process, the tool tip of each layer moves along the X direction, and the offset in the Z direction is equal. The tool tip position offset of each layer relative to the origin O is Z. i , Z i for:

[0071]

[0072] The offset X of the tool tip position relative to the origin O in the X direction when the tool is machining the nth layer n for:

[0073] X n =nΔX 设定

[0074] The origin O is the intersection of the tooth top and the tooth profile symmetry axis. During rough machining, the tool-driving method is used for each layer. Each layer has two tools, and the machining offset of each tool in each layer is (X n , Z i ) and (X n , -Z i Processing process: First, (X1, Z i ) is used as the offset to process the first cut, with (X1, -Z i ) is used as the offset to process the second cut, thus completing the first layer processing; then (X2, Z i ) is used as the offset to process the third cut, and then (X2, -Z i ) is the fourth cut for offset processing; repeat this process until the first layer is completed, that is, the offset (X l , Z i ) and (X l , -Z i ) processing.

[0075] This process does not perform tooth profile profiling or tooth top arc processing, but only removes a large amount of material at the maximum feed rate. Therefore, this process can be recorded as the rough processing process of arc thread.

[0076] 3. Perform tooth side processing.

[0077] Since the tool is not changed when machining the tooth flanks, the same arc turning tool used for machining the tooth top is still used. However, the side of the arc turning tool is a curved surface that is tangent to the edge of the tooth profile angle to be machined, so the tooth profile angle needs to be profiled. During the profiling process, it is necessary to ensure the roughness of the tooth profile angle and establish the relationship between the arc turning tool shape and the tooth profile angle. The present invention controls the position of the tool tip at intervals of the required feed amount in the radial feed direction and the product of the required feed amount and half the cosine value of the tooth profile angle in the axial direction. The second position is used to determine the tool tip offset coordinates of each layer when machining the tooth flanks, and the tooth flanks are processed in layers according to the tool tip offset coordinates of each layer.

[0078] 1) Determine the maximum feed amount during tooth side machining and use this to determine the feed amount required for each cut

[0079] like Figure 5 As shown, the tooth side height H is calculated based on the tooth height, tooth bottom radius and tooth profile angle 侧 , H 侧 The calculation formula is:

[0080]

[0081] According to the required roughness R Z Calculate the maximum feed ΔX required for machining the tooth side 牙侧max ,like Figure 6 As shown, the roughness R Z The relationship with the tool arc radius is as follows:

[0082] R z =R 刀 -AB

[0083]

[0084] ΔL=2OB

[0085] like Figure 7 As shown, considering the tooth profile angle θ, the maximum feed amount ΔX in the X direction during tooth side machining is 牙侧max =ΔL multiplied by Based on the previously calculated ΔL, ΔX 牙侧max The calculation formula is:

[0086]

[0087] ΔX 牙侧maxThe number of layers m required for tooth flank machining is calculated as the maximum feed amount in the X direction during tooth flank machining. The feed amount required for tooth flank machining is calculated based on the required number of layers and tooth flank height to ensure that the feed amount for each cut during tooth flank machining is the same. The calculation formulas for the number of layers m required for tooth flank machining and the feed amount required for tooth flank machining are:

[0088]

[0089] As another embodiment, m can also be increased on this basis. The more it increases, the more processing layers are required.

[0090] 2) Process the tooth side in layers at equal intervals according to the required feed amount

[0091] The processing of each layer on the tooth side is still carried out in layers by the way of chasing the knife, and each layer has two knives, such as Figure 8 As shown, the machining offsets of each tool in each layer are (X j , Z j ) and (X j , -Z j ), X j Indicates the offset in the radial feed direction of the turning tool when machining the jth layer on the tooth side, Z j Indicates the offset in the direction of the machine tool rotation axis when machining the jth layer of the tooth side, X j and Z j The calculation formula used is:

[0092] X j =X A +jΔX 牙侧

[0093]

[0094] If the tool is fed from right to left during machining, first calculate the Z-axis offset Z1 and X-axis offset X1 of the first tool according to the formula. When machining the first layer, first use (X1, Z1) as the offset to machine the first tool, and then use (X1, -Z1) as the offset to machine the last tool. At this point, the first layer is machined. Then use ΔX 牙侧 For X-axis stepping, process the second and third layers until the mth layer is completed. At this time, mΔX 牙测 Equal to H 侧 .

[0095] Through the above process, the tooth side processing can be completed using the arc turning tool.

[0096] 4. Perform arc processing on the tooth bottom.

[0097] 1) Determine the step angle when machining the tooth bottom arc based on surface roughness

[0098] like Figure 9 As shown, O 刀 is the center of the current tool tip arc, O′ 刀 is the center of the tool tip arc of the next cut, and the step angle between two adjacent cuts is Δβ. According to the cosine theorem, the calculation formula of Δβ is as follows:

[0099]

[0100] Among them, R z The surface roughness is the surface roughness. According to the surface roughness, the tooth bottom arc radius and the tool tip radius, the step angle suitable for the arc tooth top can be calculated.

[0101] 2) Calculate the offset coordinates of each cut when the tool moves

[0102] First, calculate the tool rotation angle of each cut. The tool rotation angle of each cut is equal to the tool rotation angle of the previous cut minus the step angle of the current layer, β n =β n-1 -Δβ,β n is the tool rotation angle of the nth tool, β n-1 is the tool rotation angle of the n-1th tool,

[0103] According to the tool tip radius, tooth profile parameters and the rotation angle of each layer of tool, calculate the offset coordinates (X n , Z n ); tooth profile parameters include tooth bottom arc radius, tooth height and tooth profile angle. Figure 10 As shown in Figure 2, for any tool n when machining the tooth bottom arc, the tool rotation angle is β n , the X-direction offset of the tool position (i.e. the center of the tool tip arc) relative to the origin O is X n The calculation formula is:

[0104] X n =HR 底 +(R 底 -R 刀 )cos(β n )

[0105] The Z offset of the tool position relative to the origin O n The calculation formula is:

[0106] Z n =(R 底 -R 刀 )sin(β n )

[0107] According to the calculated offset coordinates (X n , Z n) and the corresponding rotation angle β n Process the arc tooth bottom until the tool rotation angle reaches

[0108] like Figure 11 As shown, in this embodiment, the feed direction is arc-shaped from right to left. First, the tool rotation angle β1 of the first cut is calculated: β1 = β0-Δβ, The tool offset coordinates (X1, Z1) of the first cut are calculated based on β1, and (X1, Z1) is used as the offset coordinates, and spiral processing is performed according to the rotation angle of β1; then the tool rotation angle β2 of the second cut is calculated: β2 = β1-Δβ, and the offset coordinates (X2, Z2) of the second cut are calculated based on β2, and (X2, Z2) is used as the offset coordinates, and spiral processing is performed according to the rotation angle of β2, and so on until the processing is completed. The tooth bottom arc processing is now completed.

[0109] Preferably, taking into account the deformation of the tool guide rod, the tool rotates counterclockwise when the tool is moving, so that there is always material supporting the tool at the current processing position, effectively reducing the tool chattering phenomenon.

[0110] Embodiment of large pitch circular arc thread profiling device

[0111] The present invention provides a high-pitch circular arc thread profiling device that can be used to execute computer program instructions to implement the high-pitch circular arc thread profiling method described in the above-mentioned method embodiment. The device can be a CNC lathe for processing threads, which executes the computer program instructions to control a circular arc turning tool to process the flanks of the circular arc thread.

Claims

1. A method for profiling large-pitch arc threads, characterized in that: The processing method includes: 1) using an arc turning tool to perform arc thread rough machining excluding profiling and tooth top arc machining along the radial feed direction of the turning tool, from a first position to a second position, wherein the second position is the center position of the tool arc when the intersection of the tool arc radius and the tooth flank and tooth top axes is tangent in the tooth flank direction, and the first position is the center position of the tool arc when the second position is translated to the point where the tool arc is tangent to the tooth top axis; 2) Use the second position as the starting point of the arc turning tool center position during tooth flank machining to perform tooth flank machining, control the tool tip position in the radial feed direction to be spaced by the required feed amount, and in the axial direction to be spaced by the product of the required feed amount and half the tangent value of the tooth profile angle, and use the second position to determine the tool tip offset coordinates of each layer when machining the tooth flank, and perform layered machining on the tooth flank according to the tool tip offset coordinates of each layer, with the axial direction being the direction of the lathe rotation axis; the required feed amount is not greater than the maximum feed amount ΔX for tooth flank machining 牙侧max , ΔX 牙侧max It is based on the roughness R required for tooth side machining z , tooth profile angle θ and tool nose radius R of arc turning tool 刀 Sure, 3) After the tooth side processing is completed, use the arc turning tool to process the arc tooth bottom.

2. The large pitch arc thread profiling method according to claim 1, characterized in that: The tool tip radius of the arc turning tool needs to meet the following conditions: Among them, R 底 is the tooth bottom radius, R 刀 W is the tool tip radius of the arc turning tool, 顶 is the tooth top width, and θ is the tooth profile angle.

3. The large pitch arc thread profiling method according to claim 1, characterized in that: Each cut in step 1) is processed according to the set feed amount, which is determined based on the maximum feed amount and the processing depth. The processing depth is the distance between the first position and the second position, which is the distance in the radial feed direction of the turning tool. The calculation formula used is: where X A is the processing depth, R 刀 is the tool nose radius of the arc turning tool, and θ is the tooth angle.

4. The large pitch arc thread profiling method according to claim 3, characterized in that: In step 1), the processing method of each layer is adopted, and each layer has two cuts. The offset coordinates of the tool tip position of each layer relative to the origin O are (X n , Z i ) and (X n , -Z i ), X n Indicates the tool tip position offset relative to the origin O in the radial feed direction of the turning tool during the nth layer machining, Z i Indicates the tool tip position offset relative to the origin O in the direction of the machine tool rotation axis during each layer processing. The origin O is the intersection of the tooth top and the tooth profile symmetry axis. n and Z i The calculation formula used is: X n =nΔX 设定 where R 刀 W is the tool tip radius of the arc turning tool, 顶 is the tooth crest width.

5. The large pitch arc thread profiling method according to claim 1, characterized in that: The required feed amount is: where ΔX 牙侧 is the required feed amount, Indicates rounding up, H 侧 is the tooth flank height, and m is the number of layers required for machining the tooth flank.

6. The large pitch circular arc thread profiling method according to claim 1 or 2, characterized in that: The step 2) performs layered processing on the tooth side according to the tool tip offset coordinates of each layer. The tool tip offset coordinates of each layer relative to the origin O are (X j , Z j ) and (X j , -Z j ), X j Indicates the offset of the turning tool in the radial feed direction relative to the origin O when machining the jth layer of the tooth side, Z j It represents the offset relative to the origin O in the direction of the machine tool rotation axis when machining the jth layer of the tooth side. The origin O is the intersection of the tooth top and the tooth profile symmetry axis. j and Z j The calculation formula used is: X j =X A +jΔX 牙侧 where X A is the processing depth, ΔX 牙侧 is the required feed amount, and θ is the tooth profile angle.

7. The large pitch circular arc thread profiling method according to claim 1 or 2, characterized in that: In step 3), the arc tooth bottom is processed according to the tool rotation angle and offset coordinates of each cut when the arc turning tool moves according to the set step angle, until the tool rotation angle is Rotate to θ is the tooth angle.

8. The method for profiling large-pitch circular arc threads according to claim 7, characterized in that: The step angle set in step 3) is determined based on the tool tip radius, tooth bottom arc radius and surface roughness of the tool, and the calculation formula used is: Among them, Δβ is the set step angle, R 刀 is the tool tip radius, R 底 R is the radius of the tooth bottom arc, Z is the surface roughness.

9. A large pitch arc thread profiling device, comprising a processor, characterized in that: The processor is used to execute computer program instructions to implement the large-pitch circular arc thread profiling method according to any one of claims 1 to 8.

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