A method for calculating the tooth profile of a tooth-shaping turning tool used for machining helical groove forming milling cutters.

Abstract

The present invention discloses a tooth profile calculation method for a shovel-toothed turning tool for processing a spiral groove forming milling cutter, comprising: S1: drawing the axial tooth profile of the spiral groove forming milling cutter to be processed, and taking the highest point of the tooth profile as the starting point for tooth profile calculation; S2: converting the tooth profile into a tooth profile composed of multiple line segments, and reading the tooth profile coordinates of the multiple line segments in the form of X and Y axis coordinate points of a plane coordinate system; S3: in order to calculate the tooth profile of the shovel-toothed turning tool for processing the spiral groove forming milling cutter, firstly calculate the corresponding coordinate points of the tooth profile of the shovel-toothed turning tool under the straight groove condition of the forming milling cutter; S4: calculating the angular displacement of each coordinate point on the tooth profile of the milling cutter in the circumference according to the left-handed or right-handed lead of the spiral groove forming milling cutter, performing a shaping calculation on the Y-axis coordinate point of the shovel-toothed turning tool according to the angular displacement and the back-shoveling amount of the milling cutter, and obtaining the final coordinates of each point of the shovel-toothed turning tool. The shaping accuracy of the present invention is high, and it is suitable for calculating the tooth profile of the shovel-toothed turning tool of various left-handed or right-handed spiral groove forming milling cutters with rake angles.

Description

Technical Field

[0001] The invention belongs to the field of special tools for mechanical processing, and in particular relates to a tooth profile calculation method of a relief tooth turning tool for processing a spiral groove forming milling cutter. Background Art

[0002] According to the chip groove structure, forming milling cutters can be divided into straight groove forming milling cutters and spiral groove forming milling cutters. Compared with straight groove forming milling cutters, spiral groove forming milling cutters have uniform circumferential cutting force, constant cutting force and smooth cutting during processing due to the blades arranged obliquely along the axial direction. It is an advanced and efficient tool.

[0003] The spiral groove forming milling cutter has good use effect, but the tool manufacturing is difficult, especially the rear edge forming processing of the forming milling cutter has always been a difficult problem in tool production. There are mainly three methods for tool manufacturing at present.

[0004] (1) Approximate method: add an angled gasket to the bottom surface of the shovel-tooth turning tool. The angle of the angled gasket is the same as the helix angle. The tooth shape of the shovel tool is enlarged proportionally according to the angle. This method has a large tooth shape error and can only be used for milling cutter production with low tooth shape accuracy requirements.

[0005] (2) Point-shovel method: the forklift turning tool is a standard blade with a standard radius at the tip. The back edge of the milling cutter is processed by point-shovel method through CNC machine tools and programming. This method has high requirements for machine tools and turning tools. Poor machine tool accuracy and wear of the radius of the turning tool tip will cause the tooth profile error to exceed the tolerance. In addition, for tooth profiles with a tooth profile angle of less than 10° or a small bottom radius, the tooth profile cannot be accurately processed due to the limitation of the blade shape.

[0006] (3) Grinding method: This method requires the configuration of a multi-axis high-precision CNC grinder and grinding wheel tooth profile calculation software for forming milling cutter processing, which has a high investment cost. Although the grinding accuracy is high, it cannot be put into actual production application due to the high processing cost. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the present invention provides a method for calculating the tooth profile of a shovel-tooth turning tool for processing a spiral groove forming milling cutter. The method has high shaping accuracy, is simple, convenient and low cost, and is suitable for the precise calculation of the tooth profile of a shovel-tooth turning tool for various left-handed or right-handed spiral groove forming milling cutters with a rake angle.

[0008] The main technical solutions adopted in the present invention are:

[0009] A tooth profile calculation method for a relief tooth turning tool for machining a spiral groove forming milling cutter, the specific steps are as follows:

[0010] S1: Draw the axial tooth profile of the spiral groove forming milling cutter to be processed, and use the highest point of the tooth profile as the starting point for tooth profile calculation;

[0011] S2: converting the tooth profile drawn in step S1 into a tooth profile composed of multiple line segments, and reading the tooth profile coordinates of the multiple line segments in the form of X-axis and Y-axis coordinate points of a plane coordinate system;

[0012] S3: Calculating the corresponding coordinate points of the tooth profile of the shovel-tooth turning tool used for machining the tooth profile of the straight groove forming milling cutter according to the tooth profile coordinates of the multi-line segment read in step S2;

[0013] S4: Calculate the angular displacement of each coordinate point on the milling cutter in the circumference according to the left-hand or right-hand lead of the spiral groove forming milling cutter, and perform shaping calculation on the Y-axis coordinate point of the relief tooth turning tool according to the angular displacement and the relief back amount of the milling cutter, so as to obtain the coordinates of each point of the relief tooth turning tool used for processing the spiral groove forming milling cutter.

[0014] Preferably, in S1, the highest point of the tooth profile is set as the origin, and the calculation of all points on the left and right sides of the highest point of the tooth profile is performed based on the highest point of the tooth profile.

[0015] Preferably, in said S2, the tooth shape drawn in step S1 is composed of arcs, straight lines and curves, and then the tooth shape drawn in step S1 is divided into multiple lines with intervals of 0.01 mm or 0.02 mm.

[0016] Preferably, the specific calculation method of S3 is as follows:

[0017] Take any point on the tooth profile on the front edge of the spiral groove forming milling cutter (X i , Y i ), according to formula (1), the corresponding coordinate points (X' i , Y' i ):

[0018]

[0019] In formula (1), K is the back relief of the milling cutter, Z is the number of milling cutter teeth, R is the maximum outer radius of the milling cutter, and γ is the front angle of the milling cutter. It is the angle between any point on the cutting edge of the milling cutter and the axial reference plane of the milling cutter.

[0020] Preferably, the specific method of step S4 is as follows:

[0021] S4-1: Calculate any point on the front edge of the spiral groove forming milling cutter (X i , Y i ) relative to the angular displacement θ of the straight slot forming milling cutter in the circumference:

[0022]

[0023] In formula (2), L is the lead of the milling cutter;

[0024] S4-2: Determine the tooth profile Y″ on the relief tooth turning tool for machining spiral groove forming milling cutter according to formula (3) i Correction value C of point coordinates:

[0025]

[0026] In formula (3), Z is the number of milling cutter teeth, and K is the amount of milling cutter back relief;

[0027] Substituting formula (2) into formula (3) yields formula (4):

[0028]

[0029] S4-3: For right-handed forming milling cutters, the left part of the tooth profile at the highest point of the tooth profile is processed later than the highest point of the tooth profile during tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and reduced. Therefore, the calculation formula for the tooth relief tool coordinate point of the left tooth profile is as follows:

[0030]

[0031] For right-handed forming milling cutters, the tooth profile on the right side of the highest point of the tooth profile is processed earlier than the highest point of the tooth profile during tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and increased. Therefore, the calculation formula for the tooth relief tool coordinate point of the right tooth profile is as follows:

[0032]

[0033] For the left-handed forming milling cutter, the tooth profile on the left side of the highest point of the tooth profile is processed earlier than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and increased. Therefore, the calculation formula of the tooth relief turning tool coordinate point of the left tooth profile is as follows:

[0034]

[0035] For the left-handed forming milling cutter, the tooth profile on the right side of the highest point of the tooth profile is processed later than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and reduced. Therefore, the calculation formula for the tooth relief turning tool coordinate point of the right tooth profile is as follows:

[0036]

[0037] Beneficial effects: The present invention provides a tooth profile calculation method for a relief tooth turning tool for machining a spiral groove forming milling cutter, which has the following advantages:

[0038] (1) The tooth profile calculation of the relief tooth turning tool of the present invention is simple and convenient, and the calculation accuracy is high, and it is suitable for processing the tooth surface of the rear blade face of the left-right rotating forming milling cutter.

[0039] (2) The design method of the shovel-tooth turning tool of the present invention does not require the purchase of additional machine tools. The existing shovel-tooth turning lathe for manufacturing straight grooves can be used to produce a formed milling cutter with a high tooth profile accuracy, which will not increase the production cost too much and is conducive to promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a schematic diagram of the end face of the spiral groove forming milling cutter of Example 1;

[0041] Figure 2 for Figure 1 Schematic diagram of the axial half section of the spiral groove forming milling cutter;

[0042] Figure 3 Schematic diagram of the conversion of the tooth profile of the spiral groove forming milling cutter of Example 1 into multiple line segments;

[0043] Figure 4 This is a schematic diagram of calculation derivation of step S3 in Example 1;

[0044] Figure 5 Schematic diagram of the derivation of formula (2) in Example 1;

[0045] Figure 6 Schematic diagram of the derivation of formula (3) in Example 1;

[0046] Figure 7 Schematic diagram of calculation derivation of step S4 in Example 1 (right-handed forming milling cutter);

[0047] Figure 8 Schematic diagram of the calculation derivation of step S4 (left-handed forming milling cutter). DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0049] Example 1

[0050] In this embodiment, the shovel-tooth turning tool of the spiral groove forming milling cutter does not use an angled gasket during processing, and the shovel-tooth turning tool is clamped horizontally on the turning tool holder. The horizontal coordinate and vertical coordinate of each point on the tooth profile of the shovel-tooth turning tool can be determined by the calculation method of the present invention. Since the spiral groove forming milling cutter has a rake angle and a helix angle, the shovel-tooth turning tool is placed horizontally, so the tooth profile of the shovel-tooth turning tool is mainly modified by shortening or lengthening the height dimension, and the axial dimension, that is, the width dimension, remains unchanged. Based on the above principle, Figure 1 and 2 The figure shows the spiral groove forming milling cutter to be processed in this embodiment, and some of its parameters are: number of teeth Z = 12; back relief amount K = 5mm; front angle γ = 2°; right-hand lead L = 1360.77mm.

[0051] The specific steps of the tooth profile calculation method of the relief tooth turning tool used to process the above-mentioned spiral groove forming milling cutter are as follows:

[0052] S1: Draw the axial tooth profile of the spiral groove forming milling cutter to be processed, and use the highest point of the tooth profile as the starting point for tooth profile calculation, that is, set the highest point of the tooth profile as the origin, and calculate all points on the left and right sides of the highest point of the tooth profile based on the highest point of the tooth profile for tooth profile calculation.

[0053] S2: The tooth profile drawn in step S1 is composed of arcs, straight lines and curves. Now the tooth profile drawn in step S1 is converted into a tooth profile composed of multiple line segments, and the tooth profile coordinates of the multiple line segments are read in the form of X and Y axis coordinate points of the plane coordinate system. In this embodiment, the tooth profile is divided into multiple lines with an interval of 0.01mm or 0.02mm that can be read by the EXCEL table to replace the arc curves, such as Figure 3 As shown. The graphics are saved as a dxf format file, and the multi-segment tooth shape in the dxf format file is read by CadAssis software, and read into the EXCEL table in the form of coordinate points. In the present invention, the CadAssis software reads the line segment coordinate point data in the dxf format file, which belongs to conventional technology, so it is not described in detail.

[0054] S3: Calculate the corresponding coordinate points of the tooth profile of the shovel-tooth turning tool used for machining the tooth profile of the straight groove forming milling cutter according to the tooth profile coordinates of the multi-line segment read in step S2. The specific calculation method is as follows:

[0055] Take any point on the tooth profile on the front edge of the spiral groove forming milling cutter (X i , Y i ), according to formula (1), the corresponding coordinate points (X' i , Y' i ):

[0056]

[0057] In formula (1), since the front edge of the tooth is parallel to the axial reference plane of the milling cutter, in the calculation of the tooth turning tool, only Y i Correction value Y' of point coordinates i , X i The point coordinates remain unchanged, X' i =X i , no correction is required, K is the back relief of the milling cutter, Z is the number of milling cutter teeth, R is the maximum outer radius of the milling cutter, γ is the front angle of the milling cutter, It is the angle between any point on the cutting edge of the milling cutter and the axial reference plane of the milling cutter.

[0058] The specific derivation process of this formula is as follows:

[0059] like Figure 4 As shown in the figure, when the milling cutter rake angle is 0°, the dotted line Ox'2 in the axial section MM is the milling cutter axial tooth shape when the rake angle is equal to 0°, that is, the axial section of the milling cutter rotary surface. When the milling cutter rake angle is greater than 0°, in order to keep the axial section of the milling cutter rotary surface unchanged, the same width X i The two points x2 (x'2) and x3 should be on the same circumference of the milling cutter, that is, O g x2=O g x3=R x (x3 is a point on the tooth profile of the positive rake milling cutter). Since the tooth back of the relief milling cutter is formed by the Archimedean spiral motion of these points x3 on the tooth profile of the cutting edge, the intersection x1 of the Archimedean spiral passing through x3 and the axial section MM has a height Ox1 = Y' i , the width is still X i The axial tooth shape of the milling cutter is the scraper tooth shape used to process the back of the milling cutter teeth.

[0060] S4: Calculate the angular displacement of each coordinate point on the spiral groove forming milling cutter in the circumference according to the left-hand or right-hand lead of the spiral groove forming milling cutter, and perform the modification calculation on the Y-axis coordinate point of the relief tooth turning tool according to the angular displacement and the relief back amount, so as to obtain the coordinates of each point of the relief tooth turning tool used for processing the spiral groove forming milling cutter. The specific method is as follows:

[0061] S4-1: Figure 5 As shown, calculate the angular displacement θ of any point Xi on the front edge of the spiral groove forming milling cutter relative to the straight groove forming milling cutter in the circumference:

[0062]

[0063] In formula (2), L is the lead of the milling cutter;

[0064] S4-2: Figure 6 As shown in the figure, the tooth shape Y″ on the shovel tooth turning tool for processing spiral groove forming milling cutter is determined according to formula (3): iCorrection value C of point coordinates:

[0065]

[0066] In formula (3), Z is the number of milling cutter teeth, K is the back-cutting amount of the milling cutter teeth;

[0067] Substituting formula (2) into formula (3) yields formula (4):

[0068]

[0069] S4-3: Since the spiral groove forming milling cutter in this embodiment has a right-hand lead, the calculation is performed according to formulas (5) and (6).

[0070] For right-handed profile milling cutters, such as Figure 7 As shown in the figure, the tooth profile on the left side of the highest point of the tooth profile is processed later than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and reduced. Therefore, the calculation formula of the tooth relief tool coordinate point of the left tooth profile is as follows:

[0071]

[0072] For right-handed profile milling cutters, such as Figure 7 As shown in the figure, the tooth profile on the right side of the highest point of the tooth profile is processed earlier than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and increased. Therefore, the calculation formula of the tooth relief tool coordinate point of the right tooth profile is as follows:

[0073]

[0074] In the present invention, if the spiral groove forming milling cutter to be processed has a left-handed lead, the remaining steps for solving the coordinates of each point of the relief tooth turning tool are the same as those in Example 1, except that formula (7) and formula (8) are applicable in step S4-3, as follows:

[0075] For left-handed forming milling cutters, such as Figure 8 As shown in the figure, the left part of the tooth profile at the highest point of the tooth profile is processed earlier than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and increased. Therefore, the calculation formula of the tooth relief tool coordinate point of the left tooth profile is as follows:

[0076]

[0077] For left-handed forming milling cutters, such as Figure 8As shown in the figure, the tooth profile on the right side of the highest point of the tooth profile is processed later than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and reduced. Therefore, the calculation formula of the tooth relief tool coordinate point of the right tooth profile is as follows:

[0078]

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A tooth profile calculation method for a relief tooth turning tool for machining a spiral groove forming milling cutter, characterized in that: The specific steps are as follows: S1: Draw the axial tooth profile of the spiral groove forming milling cutter to be processed, and use the highest point of the tooth profile as the starting point for tooth profile calculation; S2: converting the tooth profile drawn in step S1 into a tooth profile composed of multiple line segments, and reading the tooth profile coordinates of the multiple line segments in the form of X-axis and Y-axis coordinate points of a plane coordinate system; S3: Calculating the corresponding coordinate points of the tooth profile of the shovel-tooth turning tool used for machining the tooth profile of the straight groove forming milling cutter according to the tooth profile coordinates of the multi-line segment read in step S2; S4: Calculate the angular displacement of each coordinate point on the milling cutter in the circumference according to the left-hand or right-hand lead of the spiral groove forming milling cutter, and perform shaping calculation on the Y-axis coordinate point of the relief tooth turning tool according to the angular displacement and the relief back amount of the milling cutter, so as to obtain the coordinates of each point of the relief tooth turning tool used for processing the spiral groove forming milling cutter.

2. The tooth profile calculation method of a relief tooth turning tool for machining a spiral groove forming milling cutter according to claim 1, characterized in that: In S1, the highest point of the tooth profile is set as the origin, and the calculation of all points on the left and right sides of the highest point of the tooth profile is performed based on the highest point of the tooth profile.

3. The tooth profile calculation method of a relief tooth turning tool for machining a spiral groove forming milling cutter according to claim 1, characterized in that: In the above S2, the tooth shape drawn in step S1 is composed of arcs, straight lines and curves, and then the tooth shape drawn in step S1 is divided into multiple lines with intervals of 0.01 mm or 0.02 mm.

4. The tooth profile calculation method of a relief tooth turning tool for machining a spiral groove forming milling cutter according to claim 1, characterized in that: The specific calculation method of S3 is as follows: Take any point on the tooth profile on the front edge of the spiral groove forming milling cutter (X i , Y i ), according to formula (1), the corresponding coordinate points (X' i , Y' i ): In formula (1), K is the back relief of the milling cutter, Z is the number of milling cutter teeth, R is the maximum outer radius of the milling cutter, and γ is the front angle of the milling cutter. It is the angle between any point on the cutting edge of the milling cutter and the axial reference plane of the milling cutter.

5. The tooth profile calculation method of a relief tooth turning tool for machining a spiral groove forming milling cutter according to claim 4, characterized in that: The specific method of step S4 is as follows: S4-1: Calculate any point on the front edge of the spiral groove forming milling cutter (X i , Y i ) relative to the angular displacement θ of the straight slot forming milling cutter in the circumference: In formula (2), L is the lead of the milling cutter; S4-2: Determine the tooth profile Y″ on the relief tooth turning tool for machining spiral groove forming milling cutter according to formula (3) i Correction value C of point coordinates: In formula (3), Z is the number of milling cutter teeth, and K is the amount of milling cutter back relief; Substituting formula (2) into formula (3) yields formula (4): S4-3: For right-handed forming milling cutters, the left part of the tooth profile at the highest point of the tooth profile is processed later than the highest point of the tooth profile during tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and reduced. Therefore, the calculation formula for the tooth relief tool coordinate point of the left tooth profile is as follows: For right-handed forming milling cutters, the tooth profile on the right side of the highest point of the tooth profile is processed earlier than the highest point of the tooth profile during tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and increased. Therefore, the calculation formula for the tooth relief tool coordinate point of the right tooth profile is as follows: For the left-handed forming milling cutter, the tooth profile on the left side of the highest point of the tooth profile is processed earlier than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and increased. Therefore, the calculation formula of the tooth relief turning tool coordinate point of the left tooth profile is as follows: For the left-handed forming milling cutter, the tooth profile on the right side of the highest point of the tooth profile is processed later than the highest point of the tooth profile during the tooth relief processing. Under the effect of the relief back value K value, the Y point coordinate of the tooth profile here needs to be corrected and reduced. Therefore, the calculation formula for the tooth relief turning tool coordinate point of the right tooth profile is as follows:

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