Grinding method for tooth cutting tool with involute type curved rake face

Abstract

The invention relates to the technical field of tool grinding, in particular to a grinding method of an involute type curved rake face tooth cutting tool, which comprises the following steps: acquiring a tooth cutting tool model, and constructing an auxiliary surface through a UG modeling module; a cutter shaft vector direction, a feeding direction and a cut plane are set through a UG machining module based on a cutter shaft control method relative to a vector, a grinding wheel is constructed through a milling cutter model to serve as a grinding cutter, parameters of the grinding cutter are set, and cutter location data are automatically generated through the UG machining module; a grinding machine model is built through a UG post-processing constructor, and grinding machine general parameters and grinding machine structure parameters are set; a. Pui file set by the post-processing constructor is called, a numerical control machining program is automatically generated through a machining module of the UG, and the tooth cutting tool is ground through the numerical control machining program. The machining method is carried out on the basis of a UG10.0 machining module and a post-processing constructor, the machining precision of the involute type curved rake face tooth cutting tool can be improved, and the blade shape precision can reach 0.005 mm.

Description

Technical Field

[0001] The invention relates to the technical field of tool grinding, and in particular to a grinding method for a tooth-cutting tool with an involute-like curved rake face. Background Art

[0002] Gear skiving technology is a high-precision and high-efficiency method for processing cylindrical gears (including internal gears, external gears, spur gears, and helical gears). It has obvious advantages in the processing of non-through internal spiral gear parts. With the in-depth research on gear skiving theory and the continuous promotion of gear skiving machine tools, the demand for gear skiving tools has gradually increased, and the use of gear skiving technology has become a trend in the gear industry.

[0003] At present, the design theory and method of gear cutting tools are becoming more and more mature. As a new type of gear cutting tool, the involute curved rake face gear cutting tool can realize high-precision cylindrical gear processing. However, the existing grinding process has low grinding accuracy and grinding efficiency when grinding the involute curved rake face gear cutting tool, which hinders the engineering application of the involute curved rake face gear cutting tool. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for grinding an involute-like curved rake face tooth cutting tool, which is used to improve the grinding accuracy and grinding efficiency of the involute-like curved rake face tooth cutting tool.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows: A grinding method for an involute-like curved rake face tooth cutting tool comprises the following steps: Obtain the tooth-scraping tool model and construct the auxiliary surface through the UG modeling module; Through the UG processing module, based on the tool axis control method relative to the vector, the tool axis vector direction, tool direction and cutting plane are set, and the grinding wheel is constructed as a grinding tool through the milling cutter model, the grinding tool parameters are set, and the tool position data is automatically generated through the UG processing module; Build the grinder model through UG's post-processing constructor and set the general parameters and structural parameters of the grinder; The .pui file set by the post-processing constructor is called, and the NC machining program is automatically generated through the UG machining module, and the gear cutting tool is ground through the NC machining program.

[0006] Furthermore, the construction method of the auxiliary surface is as follows: Select several boundary points of the machined surface of the gear cutting tool, then construct two line segments with intersection points, use the two line segments with intersection points to construct a reference plane, draw a sketch in the reference plane, the sketch is to construct a rectangle with the two line segments with intersection points as reference, and then stretch the rectangle by 0.001mm along the normal direction of the reference plane, and the auxiliary surface is constructed.

[0007] Furthermore, through the processing module of UG, based on the tool axis control method relative to the vector, the tool axis vector direction is the tooth direction, the tool feed direction is the tooth direction, the auxiliary surface constructed by the cut plane is selected, and the grinding wheel is constructed as the grinding tool through the milling cutter model. The grinding tool parameters are set, and the tool position data is automatically generated through the processing module of UG.

[0008] Furthermore, the grinding tool parameters are as follows: spindle speed of 3000 rpm, feed speed of 150 mmpm, grinding depth of 0.2 mm, and the remaining parameters are system default values.

[0009] Furthermore, through the UG processing module based on the tool axis control method relative to the vector, the tool axis vector direction is the normal vector of any point in the center area of ​​the machined surface, the tool direction is from the tooth root to the tooth top, the cutting plane selects the back tool face or the front tool face in the tooth cutting tool model, and the grinding wheel is constructed as the grinding tool through the milling cutter model. The grinding tool parameters are set, and the tool position data is automatically generated through the UG processing module.

[0010] Furthermore, the grinding tool parameters are as follows: spindle speed of 3000 rpm, feed speed of 150 mmpm, grinding depth of 0.01 mm, and the remaining parameters are system default values.

[0011] Furthermore, UG is version UG10.0.

[0012] Furthermore, the grinding machine model constructed by the post-processing constructor of UG is a Walter five-axis tool grinder model.

[0013] Furthermore, the general parameters of the Walter five-axis tool grinder model are set as follows: Post-processing output unit: Metric, Output circular record: Yes; Linear axis travel limit: X axis is 700, Y axis is 700, Z axis is 300; Zero return position: X axis is 300, Y axis is 300, Z axis is 250; Linear motion resolution: minimum value is 0.001; Move to feed rate: the maximum value is 10000; Initial principal axes: I is 0.0, J is 0.0, K is 1.0.

[0014] Furthermore, the structural parameters of the Walter five-axis tool grinder model are as follows: The 4th axis: the rotation plane of the machine head is YZ, and the text guide line of the machine head is A; The fifth axis: the rotation plane of the machining table is XY, and the text guide line of the machining table is C; Maximum feed rate: 10000; Pivot distance: 0; Linear Interpolation: Select the rotation angle, the default tolerance is 0.01.

[0015] The above scheme has the following beneficial effects: The present invention is based on the processing module and post-processing constructor of UG10.0, uses the relative vector tool axis control method of the processing module to output tool position data, and uses the post-processing constructor to build a five-axis tool grinder model for post-processing, that is, converting the tool position data into a CNC machining program. Compared with the prior art, this solution can improve the grinding accuracy and efficiency of involute-like curved rake face tooth cutting tools, and the blade shape accuracy can reach 0.005mm.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a flow chart of a method according to an embodiment of the present invention; Figure 2 Schematic diagram of a tooth-scraping tool model according to an embodiment of the present invention; Figure 3 A schematic diagram of an auxiliary surface of a processed surface according to an embodiment of the present invention; Figure 4 A schematic diagram of general parameter settings of a grinding machine according to an embodiment of the present invention; Figure 5 Schematic diagram of the setting of structural parameters of a grinding machine according to an embodiment of the present invention.

[0018] The reference numerals in the drawings of the specification include: 1, cutter tooth; 2, back cutter surface; 3, curved front cutter surface; 4, tooth groove; 5, auxiliary surface. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The following is further described in detail through specific implementation methods: Embodiment 1, as Figure 1 As shown: A grinding method for a 3-toothed tool with an involute-like curved rake face, this embodiment is based on Figure 2 Take the grinding of the involute type curved rake face 3 tooth cutting tool shown in as an example, the involute type curved rake face 3 tooth cutting tool is mainly composed of a tool body and a plurality of teeth 1 evenly distributed around the circumference of the tool body, the tooth 1 is composed of a curved rake face 3, a back face 2 and a cutting edge, and there are tooth grooves 4 between the teeth 1. The grinding method is as follows: The tooth-scraping tool model is obtained, and the auxiliary surface 5 is constructed by the modeling module of UG. The file format of the tooth-scraping tool model is preferably step, and the UG software version used in the whole method step is UG10.0. The construction method of the auxiliary surface 5 is as follows: Select several boundary points of the machined surface of the tooth cutting tool, then construct two line segments with intersection points, use the two line segments with intersection points to construct a reference plane, draw a sketch in the reference plane, the sketch is to construct a rectangle with the two line segments with intersection points as reference, and then stretch the rectangle by 0.001mm along the normal direction of the reference plane, and the auxiliary surface 5 is constructed. Figure 3 After the auxiliary surface 5 is constructed by the above method, the machining allowance of the curved rake face 3 and the flank face 2 of the tooth cutting tool can be controlled within 0.01 mm.

[0021] Through the processing module of UG10.0, based on the tool axis control method relative to the vector, the tool axis vector direction, tool direction and cutting plane are set, and the grinding wheel is constructed as a grinding tool through the milling cutter model, and the grinding tool parameters are set. The tool position data is automatically generated through the processing module of UG10.0. Specifically, it can be done in the following two ways: (1) Based on the tool axis control method relative to the vector, the tool axis vector direction is the tooth direction, the tool feed direction is the tooth direction, the auxiliary surface 5 constructed is selected as the cutting plane, the grinding wheel is constructed as the grinding tool through the milling cutter model, the grinding tool parameters are set, and the tool position data is automatically generated through the processing module of UG10.0. The grinding tool parameters set in this way are the spindle speed of 3000rpm, the feed speed of 150mmpm, the grinding depth of 0.2mm, and the other parameters are the system default values. At this time, the tool machining allowance is controlled at 0.01mm.

[0022] (2) Based on the tool axis control method relative to the vector, the tool axis vector direction is the normal vector of any point in the center area of ​​the machined surface, the tool direction is from the root to the top of the tooth, and the cut plane is the back tool face 2 or the front tool face in the tooth cutting tool model. The grinding wheel is constructed as the grinding tool through the milling cutter model, and the grinding tool parameters are set. The tool position data is automatically generated through the processing module of UG10.0. The grinding tool parameters set in this way are 3000rpm, the feed speed is 150mmpm, the grinding depth is 0.01mm, and the other parameters are the system default values. At this time, the tool machining allowance is controlled at 0.001mm.

[0023] According to the actual grinding requirements, after selecting any of the above methods to generate tool position data, build a grinder model through the post-processing constructor of UG10.0, and set the general parameters and structural parameters of the grinder. Specifically, the grinder model is a Walter five-axis tool grinder model. The general parameters of the Walter five-axis tool grinder model are set as follows: Post-processing output unit: Metric, Output circular record: Yes; Linear axis travel limit: X axis is 700, Y axis is 700, Z axis is 300; Zero return position: X axis is 300, Y axis is 300, Z axis is 250; Linear motion resolution: minimum value is 0.001; Move to feed rate: the maximum value is 10000; Initial spindle: I is 0.0, J is 0.0, K is 1.0; see Figure 4 shown.

[0024] The above general parameters are close to the real values ​​of the grinding machine.

[0025] Walter five-axis tool grinder model structural parameters are as follows: The 4th axis: the rotation plane of the machine head is YZ, and the text guide line of the machine head is A; The fifth axis: the rotation plane of the machining table is XY, and the text guide line of the machining table is C; Maximum feed rate: 10,000 degrees / minute, that is, the angle change per minute is 10,000 degrees; Pivot distance: 0; Linear interpolation: Select the rotation angle, the default tolerance is 0.01; see Figure 5 shown.

[0026] The above structural parameters are also close to the actual values ​​of the grinder.

[0027] Call the .pui file set by the post-processing constructor, automatically generate a NC machining program through the processing module of UG10.0, and grind the tooth cutting tool through the NC machining program. Specifically, select the .pui file set by the post-processing constructor as the post-processing file, and run the post-processing process. The processing module of UG10.0 automatically generates a NC machining program consisting of G code or M code. This NC machining program can be used for CNC machine tools. Figure 1 The involute-like curved rake face tooth cutting tool shown in the figure is ground.

[0028] In this embodiment, the efficiency of grinding the involute-like curved rake face tooth-cutting tool is high, and the finished involute-like curved rake face tooth-cutting tool has high precision, and the blade shape precision can reach 0.005mm.

[0029] Embodiment 2. This embodiment proposes a method for monitoring the grinding state of the above-mentioned involute type curved front blade tooth cutting tool during the grinding process, ensuring that the processing state of each tooth of the involute type curved front blade tooth cutting tool can be monitored in real time during the grinding process, and the processing status of each tooth of the tooth cutting tool can be obtained in real time.

[0030] First, based on the CNC machining program generated by Example 1, the contact time points between the blank (the blank used for grinding the involute-type curved front blade tooth-cutting tool) and the grinding wheel and the contact area at each contact time point during the entire machining process are obtained; based on the contact time points between the blank and the grinding wheel and the contact area at each contact time point during the entire machining process, a verification curve is obtained through a spline fitting curve. The verification curve here is used to verify the machining conditions of each tooth of the tooth-cutting tool in the subsequent machining process. Since the parameters of each tooth of the involute-type curved front blade tooth-cutting tool are consistent, the contact time points between the blank and the grinding wheel and the contact area at each contact time point during the entire machining process can be replaced by obtaining the contact time points between the blank and the grinding wheel and the contact area at each contact time point during the machining of a single tooth, thereby obtaining a verification curve, which is used to verify the machining conditions of each tooth.

[0031] The verification of the machining condition of the cutter teeth mainly includes whether the flank face, curved rake face and cutting edge are ground accurately. In the actual grinding process, if the contact time point and the contact area between the grinding wheel and the blank at each contact time point match the estimated value of the CNC machining program, it means that the flank face, curved rake face and cutting edge are ground accurately. Otherwise, there is an inaccurate grinding situation.

[0032] Based on the above, by installing the first detection terminal at the blank clamping end and the second detection terminal at the grinding wheel driving end, it is necessary to ensure that the contact sections of the first detection terminal and the second detection terminal are in effective contact with the blank and the grinding wheel respectively, while the first detection terminal and the second detection terminal connection terminals remain stationary. The functions of the above-mentioned first detection terminal and the second detection terminal can be achieved with the aid of customized slip rings.

[0033] Then, the real-time contact resistance between the blank and the grinding wheel during the grinding process is measured based on the first detection terminal and the second detection terminal through a four-wire resistance measurement method. The four-wire resistance measurement method uses two pairs of test wires (one pair is used to add current and the other pair is used to measure voltage) to eliminate the influence of test wire resistance on the measurement results, thereby improving the contact resistance. measurement accuracy.

[0034] Getting the contact resistance Afterwards, it can be based on The contact area between the grinding wheel and the blank is calculated. Before that, the resistivity of the grinding wheel needs to be obtained, and the influence of the temperature change of the grinding wheel on its resistivity during the grinding process needs to be considered. Therefore, the temperature of the grinding wheel needs to be monitored in real time to calculate the real-time resistivity of the grinding wheel. The calculation formula is as follows:

[0035] In the formula, is the real-time resistivity of the grinding wheel, is the initial resistivity of the grinding wheel (the resistivity of the grinding wheel at 20°C, obtained from the material resistivity table), is the temperature coefficient of resistivity (obtained from the material resistivity coefficient table), is the grinding wheel temperature at time t being monitored, is a constant of 20 (corresponding to The temperature of the value is 20℃).

[0036] The actual contact area between the grinding wheel and the blank at each contact time point is then calculated using the following formula:

[0037] And based on whether contact resistance is generated as well as The actual contact time point between the grinding wheel and the blank is obtained by the generated time length, and the working curve is obtained by spline fitting curve based on each actual contact time point and the contact area between the two at each actual contact time point. Due to the influence of factors such as pressure changes at the contact point between the blank and the grinding wheel during the actual grinding process of the gear cutting tool, the working curve is usually different from the verification curve in terms of value, but the initial time point, shape and end time point of the two are usually highly similar.

[0038] Therefore, when judging whether the contact time points and contact areas of the grinding wheel and the blank match the estimated values ​​of the CNC machining program at each contact time point, the similarity of the initial time point, shape and end time point of the working curve and the verification curve is compared to estimate whether the back face, curved front face and cutting edge of each tooth in the tooth-cutting tool are accurately ground. Accordingly, the shape difference points between the working curve and the verification curve (usually a difference threshold is set, and when the shape difference is greater than the difference threshold, it is defined as a shape difference point) can be obtained, and the time points of the shape difference points correspond to the time points where there may be inaccurate grinding, thereby obtaining the time points of inaccurate grinding during the grinding process of the tooth-cutting tool, and the position of inaccurate grinding can also be obtained based on this.

[0039] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for grinding a tooth cutting tool with an involute-like curved rake face, characterized in that: The steps include: Obtain the tooth-scraping tool model and construct the auxiliary surface through the UG modeling module; Through the UG processing module, based on the tool axis control method relative to the vector, the tool axis vector direction, tool direction and cutting plane are set, and the grinding wheel is constructed as a grinding tool through the milling cutter model, the grinding tool parameters are set, and the tool position data is automatically generated through the UG processing module; Build the grinder model through UG's post-processing constructor and set the general parameters and structural parameters of the grinder; The .pui file set by the post-processing constructor is called, and the NC machining program is automatically generated through the UG machining module, and the gear cutting tool is ground through the NC machining program.

2. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 1, characterized in that: The construction method of the auxiliary surface is as follows: Select several boundary points of the machined surface of the gear cutting tool, then construct two line segments with intersection points, use the two line segments with intersection points to construct a reference plane, draw a sketch in the reference plane, the sketch is to construct a rectangle with the two line segments with intersection points as reference, and then stretch the rectangle by 0.001mm along the normal direction of the reference plane, and the auxiliary surface is constructed.

3. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 1, characterized in that: Through the UG processing module, the tool axis control method relative to the vector is based on the tool axis vector direction is the tooth direction, the tool feed direction is the tooth direction, the auxiliary surface of the cut plane is selected as the construction, and the grinding wheel is constructed as the grinding tool through the milling cutter model. The grinding tool parameters are set, and the tool position data is automatically generated through the UG processing module.

4. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 3, characterized in that: The grinding tool parameters are as follows: spindle speed of 3000rpm, feed speed of 150mmpm, grinding depth of 0.2mm, and the rest of the parameters are system default values.

5. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 1, characterized in that: Through the UG processing module, the tool axis control method relative to the vector is based on the tool axis vector direction, which is the normal vector of any point in the center area of ​​the machined surface. The tool direction is from the tooth root to the tooth top. The cut plane is the back tool face or the front tool face in the tooth cutting tool model. The grinding wheel is constructed as the grinding tool through the milling cutter model, and the grinding tool parameters are set. The tool position data is automatically generated through the UG processing module.

6. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 5, characterized in that: The grinding tool parameters are as follows: spindle speed of 3000rpm, feed speed of 150mmpm, grinding depth of 0.01mm, and the rest of the parameters are system default values.

7. The method for grinding a tooth-cutting tool with an involute-like curved rake face according to any one of claims 1 to 6, characterized in that: UG is version UG10.

0.

8. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 7, characterized in that: The grinding machine model built by UG's post-processing constructor is a Walter five-axis tool grinder model.

9. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 8, characterized in that: The general parameters of the Walter five-axis tool grinder model are as follows: Post-processing output unit: Metric, Output circular record: Yes; Linear axis travel limit: X axis is 700, Y axis is 700, Z axis is 300; Zero return position: X axis is 300, Y axis is 300, Z axis is 250; Linear motion resolution: minimum value is 0.001; Move to feed rate: the maximum value is 10000; Initial principal axes: I is 0.0, J is 0.0, K is 1.

0.

10. The grinding method of the involute-shaped rake face tooth cutting tool according to claim 9, characterized in that: Walter five-axis tool grinder model structural parameters are as follows: The 4th axis: the rotation plane of the machine head is YZ, and the text guide line of the machine head is A; The fifth axis: the rotation plane of the machining table is XY, and the text guide line of the machining table is C; Maximum feed rate: 10000; Pivot distance: 0; Linear Interpolation: Select the rotation angle, the default tolerance is 0.01.

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