A method for measuring and compensating tooth pitch on a machine during forming gear grinding

Abstract

The invention relates to the field of gear detection technology and compensation for gear grinding, and specifically to a pitch measurement and compensation method in the gear grinding process. In view of the fact that the pitch measurement on the machine in the current gear grinding process takes too long, and the pitch error is difficult to be effectively compensated in the grinding process, in order to improve the pitch accuracy and efficiency in the gear processing of a forming gear grinding machine, a single-side pitch measurement scheme in the same direction of rotation and feeding of a turntable in the grinding process is proposed in the forming gear grinding process, and a C-axis (turntable) micro-compensation method for the grinding process is performed based on the accumulated error of the single-tooth pitch. The method is mainly used in the gear processing process of the forming gear grinding machine, and the basic steps are: after the grinding of a single tool-feeding process is completed, the accumulated error of the single-tooth pitch rotating in the same direction of the turntable in the grinding process is measured, and the compensation value is added to the next tool-feeding grinding process through reverse compensation, thereby improving the pitch accuracy and efficiency of the forming gear grinding process.

Description

Technical Field

[0001] The invention relates to the field of gear detection technology and compensation for gears during gear grinding, and in particular to an on-machine tooth pitch measurement and compensation method during a forming gear grinding process. Background Art

[0002] Gear grinding is the last step in gear processing. In the field of large gear processing, the processing accuracy of domestic gear grinding machines is still insufficient compared with foreign machine tools. As a high-end gear CNC machine tool, it is necessary to improve the processing accuracy of gear grinding machines and break through foreign technical barriers. In order to improve the processing accuracy of gear grinding machines, China has studied the processing mechanism of gear grinding machines and has certain compensation methods, but most of them focus on the compensation of tooth shape and tooth direction accuracy. There is basically no efficient pitch compensation method in the gear grinding process. Therefore, it is necessary to study the on-machine detection and compensation method of tooth pitch during gear grinding.

[0003] There is not much pitch compensation in the current domestic gear grinding machines on the market. In the gear grinding machine processing, there is no efficient pitch measurement. The current pitch measurement is for double-sided teeth, which is time-consuming and cannot be used as a compensation value to improve the accuracy of the processed gears. Summary of the invention

[0004] The object of the present invention is to provide a method for measuring and compensating tooth pitch on a machine during a forming gear grinding process, so as to reduce the on-machine measurement time of tooth pitch during the gear grinding process and improve the tooth pitch accuracy of the gear grinding process.

[0005] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0006] A method for measuring and compensating tooth pitch on a machine during a forming gear grinding process, characterized in that it comprises the following steps:

[0007] Step 1: Single tooth pitch measurement on machine during gear grinding process;

[0008] Step 2: offset of the initial position of the gear grinding process;

[0009] Step 3: Calculation of pitch compensation value.

[0010] The step 1: measuring the single tooth pitch on the machine during the gear grinding process, specifically includes the following contents:

[0011] 1) After completing the gear grinding parameters in the previous step, perform on-machine measurement of the single tooth surface pitch;

[0012] 2) When measuring the tooth pitch, the machine tool turntable rotation direction during measurement and grinding must be the same to eliminate the influence of the turntable anti-backlash error.

[0013] The step 2: offsetting the initial position of the gear grinding process, specifically includes the following contents:

[0014] 1) Obtain the cumulative error of single tooth pitch;

[0015] 2) Calculate the average value of the cumulative pitch error Fp(AVG);

[0016] 3) The starting position of the turntable processing is offset.

[0017] The step three: calculating the pitch compensation value, specifically includes the following contents:

[0018] 1) After obtaining the cumulative pitch error of a single tooth surface, the pitch error compensation value is calculated by reversely calculating the cumulative pitch error based on the offset of the initial processing position of the turntable;

[0019] 2) Add the compensation value to the C value to obtain the C value parameter of the next gear grinding pass;

[0020] Furthermore, the next grinding pass parameter is then performed. After the next pass is completed, return to step one to measure the cumulative error of the single tooth surface pitch. If compensation is required, continue with step two and step three. If compensation is not required, perform the next grinding pass parameter until the gear grinding process is completed.

[0021] In the step 1, the single tooth surface pitch during the gear grinding process is measured on the machine, and the rotation feed direction of the turntable during the measurement is the same as the grinding feed direction.

[0022] In step 2, 3) the calculation formula for the turntable machining starting position offset is:

[0023] C1=C0+Fp(AVG) / π*180

[0024] Where: C1 is the starting position of the gear grinding process after offset, and C0 is the starting position of the initial gear grinding process.

[0025] In the step 3, 1) the pitch error compensation value is calculated by reversely calculating the pitch cumulative error, and the calculation formula is:

[0026] Fpkb=-(Fpk-Fp(AVG))

[0027] Where: Fpkb is the compensation value of the Kth tooth, and Fpk is the compensation value of the cumulative error of a single tooth surface.

[0028] In step 3, 2), the compensation value is calculated by adding the C value, and the calculation formula is:

[0029] Ckb=Ck+Fpkb / π*180

[0030] Where: Ckb is the C value of the Kth tooth after compensation, and Ck is the C value of the Kth tooth before compensation.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention shortens the effective on-machine measurement time of the gear grinding process, and the accumulated error value of the on-machine measurement of the gear pitch can be used as a compensation program, thereby increasing the utilization rate of the on-machine measurement of the gear pitch during the gear grinding process and improving the efficiency of the gear grinding process.

[0033] 2. The present invention has a concise operation process and a simple calculation formula, which greatly reduces the amount of calculation in the gear grinding process and reduces the probability of errors in the calculation process.

[0034] 3. The present invention is based on the current status of domestic gear grinding machines on the market, and compensates for the pitch error, thereby filling the weakness of the current domestic gear grinding machines in pitch error compensation and improving the machining accuracy of the gear grinding machines. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a two-dimensional schematic diagram of the gear workpiece grinding process;

[0036] Figure 2 This is a schematic diagram of single tooth pitch measurement during gear grinding;

[0037] Figure 3 This is a schematic diagram of the cumulative pitch error in single pitch measurement;

[0038] Figure 4 This is a schematic diagram of the initial position offset of the gear grinding rotary table;

[0039] Figure 5 This is a schematic diagram of the cumulative error compensation value of the gear pitch during gear grinding;

[0040] Figure 6 This is a flow chart for on-machine detection and compensation of tooth pitch during gear grinding. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0042] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0043] A method for measuring and compensating tooth pitch on a machine during a forming gear grinding process, characterized in that it comprises the following steps:

[0044] Step 1: Single tooth pitch measurement on machine during gear grinding process;

[0045] Step 2: offset of the initial position of the gear grinding process;

[0046] Step 3: Calculation of pitch compensation value.

[0047] The step 1: measuring the single tooth pitch on the machine during the gear grinding process, specifically includes the following contents:

[0048] 1) After completing the gear grinding parameters in the previous step, perform on-machine measurement of the single tooth surface pitch;

[0049] 2) When measuring the tooth pitch, the machine tool turntable rotation direction during measurement and grinding must be the same to eliminate the influence of the turntable anti-backlash error.

[0050] The step 2: offsetting the initial position of the gear grinding process, specifically includes the following contents:

[0051] 1) Obtain the cumulative error of single tooth pitch;

[0052] 2) Calculate the average value of the cumulative pitch error Fp(AVG);

[0053] 3) The starting position of the turntable processing is offset.

[0054] The step three: calculating the pitch compensation value, specifically includes the following contents:

[0055] 1) After obtaining the cumulative pitch error of a single tooth surface, the pitch error compensation value is calculated by reversely calculating the cumulative pitch error based on the offset of the initial processing position of the turntable;

[0056] 2) Add the compensation value to the C value to obtain the C value parameter of the next gear grinding pass;

[0057] Furthermore, the next grinding pass parameter is then performed. After the next pass is completed, return to step one to measure the cumulative error of the single tooth surface pitch. If compensation is required, continue with step two and step three. If compensation is not required, perform the next grinding pass parameter until the gear grinding process is completed.

[0058] In the step 1, the single tooth surface pitch during the gear grinding process is measured on the machine, and the rotation feed direction of the turntable during the measurement is the same as the grinding feed direction.

[0059] In step 2, 3) the calculation formula for the turntable machining starting position offset is:

[0060] C1=C0+Fp(AVG) / π*180

[0061] Where: C1 is the starting position of the gear grinding process after offset, and C0 is the starting position of the initial gear grinding process.

[0062] In the step 3, 1) the pitch error compensation value is calculated by reversely calculating the pitch cumulative error, and the calculation formula is:

[0063] Fpkb=-(Fpk-Fp(AVG))

[0064] Where: Fpkb is the compensation value of the Kth tooth, and Fpk is the compensation value of the cumulative error of a single tooth surface.

[0065] In step 3, 2), the compensation value is calculated by adding the C value, and the calculation formula is:

[0066] Ckb=Ck+Fpkb / π*180

[0067] Where: Ckb is the C value of the Kth tooth after compensation, and Ck is the C value of the Kth tooth before compensation.

[0068] This article takes the grinding of cylindrical external gears and the on-machine measurement and compensation of their tooth pitch as an example to illustrate. For other gears, specific adjustments are made according to different types of gears, which will not be explained here.

[0069] like Figure 1 As shown, Figure 1 The cylindrical external gear is ground. The view is a top view. During the profile grinding process, the turntable rotates in the feed direction.

[0070] After completing the current grinding process, you can choose to proceed to the next grinding process, or you can choose to measure the single pitch cumulative error, depending on the operator and actual needs.

[0071] If measurements are taken, Figure 2 As shown in the figure, when measuring, the rotary table should rotate in the same feeding direction as the grinding process. Figure 2 In the process, measure the cumulative pitch error of the left tooth surface.

[0072] Next, the accumulated pitch error of the left tooth surface can be obtained after measurement, and the average accumulated pitch error Fp(AVG) can be calculated, as follows: Figure 3 shown.

[0073] According to the above Figure 3 The calculated average value of the cumulative pitch error Fp (AVG) is used to offset the initial position of the turntable in order to make the subsequent grinding allowance evenly distributed. The specific calculation formula is as follows:

[0074] C1=C0+Fp(AVG) / π*180

[0075] Where: C1 is the starting position of the gear grinding process after offset, and C0 is the starting position of the initial gear grinding process.

[0076] Based on the above steps, the initial position of the gear grinding process is offset, such as Figure 4 As shown; then the compensation value is calculated in reverse based on the accumulated error of the left tooth pitch, as shown Figure 5 shown.

[0077] Next, taking the left tooth surface as the reference, the accumulated error compensation value of the left tooth surface pitch is added into the process parameters of the next grinding pass. The specific calculation formula is as follows:

[0078] Ckb=Ck+Fpkb / π*180

[0079] Where: Ckb is the C value of the Kth tooth after compensation, and Ck is the C value of the Kth tooth before compensation.

[0080] Finally, if the subsequent tool parameters are completed, select to measure and repeat the above steps in sequence until the gear grinding process is completed. The specific flow chart is as follows: Figure 6 shown.

[0081] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for measuring and compensating tooth pitch in a machine during a profile gear grinding process, characterized in that: The steps include: Step 1: Single tooth pitch measurement on machine during gear grinding process; Step 2: offset of the initial position of the gear grinding process; Step 3: Calculation of pitch compensation value; The step 1: measuring the single tooth pitch on the machine during the gear grinding process, specifically includes the following contents: 1) After completing the gear grinding parameters in the previous step, perform on-machine measurement of the single tooth surface pitch; 2) When measuring the pitch, the rotation direction of the machine tool turntable during measurement and grinding must be the same, so as to eliminate the influence of the turntable anti-backlash error; Step 2: offset of the initial position of the gear grinding process, specifically includes the following contents: 1) Obtain the cumulative error of single tooth pitch; 2) Calculate the average value of the cumulative pitch error Fp(AVG); 3) Rotary table processing starting position offset; The step three: calculating the pitch compensation value, specifically includes the following contents: 1) After obtaining the cumulative pitch error of a single tooth surface, the pitch error compensation value is calculated by reversely calculating the cumulative pitch error based on the offset of the initial processing position of the turntable; 2) Add the compensation value to the C value to obtain the C value parameter of the next gear grinding pass; Further, the next grinding pass parameter is then performed. After the next pass is completed, the step can be returned to step 1 to measure the cumulative error of the single tooth pitch. If compensation is required, the steps 2 and 3 are continued. If compensation is not required, the next grinding pass parameter is performed until the gear grinding process is completed. In the step 1, the single tooth pitch during the gear grinding process is measured on the machine, and the rotation feed direction of the turntable during the measurement is the same as the grinding feed direction. In the step 2, 3) the turntable processing starting position offset is calculated as follows: C1=C0+Fp(AVG) / π*180 Wherein: C1 is the starting position of the gear grinding process after the offset, and C0 is the starting position of the initial gear grinding process; in the step 3, 1) the pitch error compensation value is calculated by reversely calculating the pitch cumulative error, and the calculation formula is: Fpkb=-(Fpk-Fp(AVG)) Where: Fpkb is the compensation value of the Kth tooth, and Fpk is the compensation value of the cumulative error of a single tooth surface; in step 3 2), the compensation value is added by the C value, and the calculation formula is: Ckb=Ck+Fpkb / π*180 Where: Ckb is the C value of the Kth tooth after compensation, and Ck is the C value of the Kth tooth before compensation.

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