A method for determining the movement coordinates of a rectangular thread machining tool for a crane

Abstract

This invention provides a method for determining the movement coordinates of a rectangular thread machining tool for cranes. When moving the tool, the distance t0 between the current thread machining diameter d4 and the thread finishing diameter d2 is calculated. The Z-movement distance of the tool is adjusted according to the size of t0 and t, ensuring that the tool moves between the starting coordinate X0 and the ending coordinate X1 of the thread's X-axis. This avoids the problem of excessive cutting where the current thread machining diameter d4 is smaller than the thread finishing diameter d2 due to the tool's coordinates exceeding the ending coordinate X1 of the thread's X-axis after movement.

Description

Technical Field

[0001] This invention relates to thread processing methods, specifically to a method for determining the movement coordinates of a rectangular thread processing tool for a crane. Background Technology

[0002] Nuts with rectangular threads are frequently used in cranes. Existing machining methods generally involve using a CNC lathe to drive a cutting tool to move the workpiece. When driving the cutting tool, the tool's movement path needs to be planned. A patent document with Chinese application number 201010548760.8 and publication date of May 23, 2012, discloses a method for machining large-pitch triangular tapered threads. This method uses the cutting tool tip to cut along the thread profile angle point by point, layer by layer. During machining, the tool can be fed from both the left and right sides. After cutting from the right and right sides, the thread to be machined can be formed in the middle. When there is a lot of residual material on the thread from the left and right feeds, a straight feed method can be used to cut off the residual material on the thread. During machining, the corresponding initial machining depth can be set as needed, and then the machine tool system calculates and gradually increases the cutting depth according to the program requirements.

[0003] This machining method processes threads by gradually increasing the depth of cut, but it cannot avoid the problem of over-cutting. Summary of the Invention

[0004] This invention provides a method for determining the moving coordinates of a rectangular thread machining tool for cranes. By adjusting the tool's feed depth on the X-axis according to the distance between the current thread machining diameter and the thread finishing diameter, the coordinates can be accurately determined and reliable movement between multiple layers can be achieved.

[0005] To achieve the above objectives, the technical solution of the present invention is: a method for determining the moving coordinates of a rectangular thread machining tool for a crane, comprising the following steps:

[0006] S1, preset depth of cut t, first thread cutting diameter d1, thread finishing diameter d2, thread angle A, and thread root width W.

[0007] S2. Determine the right limit coordinates T1 and the left limit coordinates T2 of the left and right deflection tools.

[0008] S3. The tool moves from the left extreme coordinate T2 to the right extreme coordinate T1, which is one tool movement.

[0009] S4. After the tool makes one pass, determine whether the current thread machining diameter d4 is equal to the thread finishing diameter d2. If the current thread machining diameter d4 is greater than the thread finishing diameter d2, proceed to S5; if the current thread machining diameter d4 is equal to the thread finishing diameter d2, proceed to S8.

[0010] S5. Calculate the distance t0 between the current thread machining diameter d4 and the thread finishing diameter d2; determine if t0 is greater than t. If t0 > t, then relative to the previous tool pass, the tool moves a distance t towards the thread's X-axis endpoint coordinate X1 along the thread's X-axis direction; if t0 < t, then relative to the previous tool pass, the tool moves a distance t0 towards the thread's X-axis endpoint coordinate X1 along the thread's X-axis direction; along the thread's Z-axis direction, the tool moves from the left limit coordinate T2 of the left and right offset tools to the right limit coordinate T1.

[0011] S6. Determine if the tool has moved to the right limit coordinate T1. If not, repeat S4 to continue moving the tool along the Z-axis direction of the thread. If yes, proceed to S7.

[0012] S7. Repeat S4-S6 to continue machining the thread and determine whether the current thread machining diameter d4 is equal to the thread finishing diameter d2.

[0013] S8. The tool retracts and separates from the workpiece, ending the thread machining process.

[0014] The above method cuts the width of the thread along the Z-axis and the depth of the thread along the X-axis. During cutting, the tool first moves along the Z-axis of the thread, performing the first layer of cutting based on the left and right limit coordinates of the cutting tool. Then, the tool moves along the X-axis of the thread, changing the cutting depth on the workpiece, and then moves along the Z-axis again to perform the second layer of cutting. Through multi-layered tool movement, layered cutting of the thread is achieved, reducing the cutting difficulty. Since the groove depth remains constant during left and right cutting, the tool only needs to perform longitudinal feed to the left or right, resulting in a simple cutting method, high cutting efficiency, and reduced error. Layered cutting, cutting layer by layer along the thread depth, reduces vibration at each cutting layer, thus reducing the generation of chatter marks.

[0015] When moving the tool, calculate the distance t0 between the current thread machining diameter d4 and the thread finishing diameter d2; adjust the Z-axis movement distance of the tool according to the size of t0 and t to ensure that the tool moves between the starting coordinate X0 and the ending coordinate X1 of the thread on the X-axis, and avoid the problem of overcutting caused by the current thread machining diameter d4 being smaller than the thread finishing diameter d2 when the coordinate of the tool after moving exceeds the ending coordinate X1 of the thread on the X-axis.

[0016] Furthermore, in S2, determining the right limit coordinate T1 and the left limit coordinate T2 of the left and right deflectors includes the following steps;

[0017] S2.1, through Calculate the right limit coordinate T1 of the left and right deflection tools.

[0018] S2.2 Calculate the left limit coordinate T2 of the left and right deflectors using T2 = -T1.

[0019] The above method calculates the right limit coordinates using the first cutting diameter d1, the finishing diameter d2, the thread angle A, and the root width W. The method is simple; at the same time, the left limit coordinates are obtained symmetrically along the midpoint of the thread.

[0020] Furthermore, S3 also includes preset thread parameters and thread taper. The feed coordinate and retraction coordinate are determined by the thread parameters and thread taper, and the tool moves to the feed coordinate. The feed coordinate is the starting coordinate of the tool, and the tool moves from the feed coordinate to the left limit coordinate T2 of the left and right offset.

[0021] The above method forms the helix of the thread by determining the feed coordinates. Attached Figure Description

[0022] Figure 1 This is a flowchart of the present invention.

[0023] Figure 2 A schematic diagram of tool movement during thread cutting. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1-2 As shown, a method for determining the movement coordinates of a rectangular thread machining tool for a crane includes the following steps:

[0026] S1. Preset the thread parameters of the rectangular thread groove. The thread parameters of the rectangular thread groove include the depth of cut t, the diameter of the first thread cut d1, the diameter of the thread finishing cut d2, the thread angle A, and the root width W.

[0027] S2. Determine the right limit coordinates T1 and the left limit coordinates T2 of the left and right deflection tools.

[0028] S3. The tool moves from the left extreme coordinate T2 to the right extreme coordinate T1, which is one tool movement.

[0029] S4. After the tool performs one pass, determine whether the current thread machining diameter d4 is equal to the thread finishing diameter d2. If the current thread machining diameter d4 is greater than the thread finishing diameter d2, proceed to S5; if the current thread machining diameter d4 is equal to the thread finishing diameter d2, proceed to S8. In this embodiment, the current X-coordinate of the tool corresponds to the current thread machining diameter d4; after the tool performs one layer of cutting on the thread, the current thread machining diameter d4 is determined by the current X-coordinate of the tool.

[0030] S5. Calculate the distance t0 between the current thread machining diameter d4 and the thread finishing diameter d2; determine if t0 is greater than t. If t0 > t, relative to the previous tool pass, the tool moves a distance t towards the thread's X-axis endpoint coordinate X1 along the thread's X-axis direction; if t0 < t, relative to the previous tool pass, the tool moves a distance t0 towards the thread's X-axis endpoint coordinate X1 along the thread's X-axis direction. Along the thread's Z-axis direction, the tool moves from the left limit coordinate T2 to the right limit coordinate T1 of the left and right offset tools. In this embodiment, the thread's X-axis endpoint coordinate X1 corresponds to the thread finishing diameter d2. When moving the tool, calculate the distance t0 between the current thread machining diameter d4 and the thread finishing diameter d2; adjust the tool's Z-axis movement distance according to the size of t0 and t to ensure the tool moves between the thread's X-axis starting coordinate X0 and the thread's X-axis ending coordinate X1, avoiding the problem of over-cutting where the current thread machining diameter d4 is smaller than the thread finishing diameter d2 due to the tool's coordinates exceeding the thread's X-axis endpoint coordinate X1 after movement.

[0031] S6. Determine if the tool has moved to the right limit coordinate T1. If not, repeat S4 to continue moving the tool along the Z-axis direction of the thread. If yes, proceed to S6.

[0032] S7. Repeat S4-S6 to continue machining the thread until the current thread machining diameter d4 is equal to the thread finishing diameter d2; then proceed to S7.

[0033] S8. The tool retracts and separates from the workpiece, ending the thread machining process.

[0034] The above method cuts the width of the thread along the Z-axis and the depth of the thread along the X-axis. During cutting, the tool first moves along the Z-axis of the thread, performing the first layer of cutting based on the left and right limit coordinates of the cutting tool. Then, the tool moves along the X-axis of the thread, changing the cutting depth on the workpiece, and then moves along the Z-axis again to perform the second layer of cutting. Through multi-layered tool movement, layered cutting of the thread is achieved, reducing the cutting difficulty. Since the groove depth remains constant during left and right cutting, the tool only needs to perform longitudinal feed to the left or right, resulting in a simple cutting method, high cutting efficiency, and reduced error. Layered cutting, cutting layer by layer along the thread depth, reduces vibration at each cutting layer, thus reducing the generation of chatter marks.

[0035] In the above method,

[0036] In S2, the right limit coordinate T1 and the left limit coordinate T2 of the left and right deflection tools are determined, including the following steps;

[0037] S2.1, through Calculate the right limit coordinate T1 of the left and right deflection tools.

[0038] S2.2 Calculate the left limit coordinate T2 of the left and right offset tools using T2 = -T1. The right limit coordinate is calculated using the first cutting diameter d1, the finishing diameter d2, the thread angle A, and the root width W, which is a simple method; simultaneously, the left limit coordinate is obtained symmetrically along the midpoint of the thread.

[0039] S3 also includes preset thread parameters and thread taper. The feed coordinate and retraction coordinates are determined using these parameters and taper, and the tool moves to the feed coordinate. The feed coordinate is the starting coordinate of the tool, and the tool moves from the feed coordinate to the left limit coordinate T2 of the left and right offset. By determining the feed coordinate, the helix of the thread is formed. In this embodiment, determining the feed coordinate and retraction coordinate using thread parameters and thread taper is existing technology, calculated through lathe programming instructions, and will not be elaborated upon here.

[0040] When machining rectangular thread grooves, the width of the rectangular thread groove is fixed. In each layer of tool feed, the left and right limit coordinates of the left and right offset tools are fixed. Therefore, it is only necessary to calculate the depth of cut of the tool.

[0041] The following examples illustrate this:

[0042] In S5, refer to Figure 2 At point K1, if the current X-axis coordinate of the tool is 13.3, then t0 is 0.6, t0 > t. At this point, the tool moves a distance t towards the X-axis endpoint coordinate X1 of the thread. The tool depth of cut is changed. After the tool completes the thread cutting at the current depth of cut, the tool needs to move again, referring to... Figure 2 At point K2, the current Z-axis coordinate of the tool is 13.1, so t0 is 0.2, t0 < t. At this time, the tool moves a distance of t0 towards the X-axis endpoint coordinate X1 of the thread; after changing the depth of cut, cutting is performed again.

Claims

1. A method for determining the position of a rectangular thread machining tool for a crane, characterized in that: The method comprises the following steps: S1, presetting a feed depth t, a thread first machining diameter d1, a thread finishing diameter d2, a thread angle A and a thread bottom width W; S2, determining a right limit coordinate T1 of left-right offset tooling and a left limit coordinate T2 of left-right offset tooling; S3, moving the tooling from the left limit coordinate T2 of left-right offset tooling to the right limit coordinate T1 as one pass; S4, after the tooling makes one pass, judging whether a current thread machining diameter d4 is equal to the thread finishing diameter d2, if the current thread machining diameter d4 is greater than the thread finishing diameter d2, S5 is performed; if the current thread machining diameter d4 is equal to the thread finishing diameter d2, S8 is performed; S5, calculating a distance t0 between the current thread machining diameter d4 and the thread finishing diameter d2; judging whether t0 is greater than t, if t0>t, the tooling is moved by a distance t along an X axis direction of the thread to an X axis end coordinate X1 of the thread relative to the last pass; if t0 S6, judging whether the tooling is moved to the right limit coordinate T1, if not, S4 is repeated to move the tooling along the Z axis direction of the thread, if yes, S7 is performed; S7, S4-S6 are repeated to continue machining the thread and judging whether the current thread machining diameter d4 is equal to the thread finishing diameter d2; S8, the tooling is retracted and separated from the machined part, and the machining of the thread is ended.

2. The method according to claim 1, characterized in that: In S2, the right limit coordinate T1 of left-right offset tooling and the left limit coordinate T2 of left-right offset tooling are determined, comprising the following steps: S2.1, by The right limit coordinate T1 of the left offset cutter is calculated. S2.2, the left limit coordinate T2 of left-right offset tooling is calculated by T2=-T1.

3. The method of claim 1, wherein: In S3, presetting thread parameters and thread taper, determining a feed coordinate and a retraction coordinate through the thread parameters and the thread taper, and moving the tooling to the feed coordinate; the feed coordinate is a starting coordinate of the tooling, and the tooling is moved from the feed coordinate to the left limit coordinate T2 of left-right offset tooling.

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