CN103769692B - On-machine measuring device and method for pitch deviation of large gear - Google Patents

Abstract

The utility model provides a large-scale gear pitch deviation is at quick-witted measuring device, includes the numerical control revolving stage of drive gear rotation and location, includes the radial numerical control slip table of drive indicator along gear radial motion, includes the axial numerical control slip table of drive indicator along gear axial motion, includes lathe electrical apparatus and numerical control system, still includes two amesdial indicators with the touching of flank of tooth. A method for measuring the pitch deviation of large gear on machine includes such steps as measuring the position of tooth surface, calculating the single pitch deviation, and calculating the cumulative pitch deviation. The method is completely based on the existing mechanical structure and control system of the gear processing machine tool, is simple and reliable, is convenient to operate, and can be used for measuring the pitch errors with low cost and high precision.

Description

On-machine measurement device and method for pitch deviation of large gears

technical field

The invention belongs to the field of gear error measurement, and in particular relates to an on-machine measurement device and method for tooth pitch deviation of large gears.

Background technique

Large gears are mainly used in important fields such as energy, transportation, and national defense. They are key components of wind power generation, large hydropower nuclear power plants, forging equipment, and transmissions on ships. Large gears are not only difficult to manufacture, but also difficult to measure. Due to the large size, it is difficult to find a suitable three-coordinate measuring instrument or gear measurement center for measurement, and there is a problem that the measurement and processing standards are difficult to unify, so large gears are generally measured by on-machine measurement methods.

Tooth pitch error is an important indicator of gear transmission error. One method of measuring the tooth pitch error on the machine is to use a turntable to touch a stylus to each tooth surface, obtain the position of the turntable corresponding to each tooth surface, and then calculate the error. This method not only has the coupling problem of the indexing error of the turntable during processing and measurement, but also has high requirements on the precision of the turntable due to the radius enlargement of the large gear, which is difficult for general machine tools to achieve. Another on-machine measurement method is to use a tooth pitch comparator, which is independent of the machine tool, expensive, and can only measure the relative value of the tooth pitch deviation, but cannot measure the absolute value of the tooth pitch deviation.

Contents of the invention

The purpose of the present invention is to provide an on-machine measurement device and method for pitch deviation of large gears. The present invention mainly provides on-machine measurement device and method for pitch deviations such as single pitch deviation and cumulative pitch deviation of large gears.

The outstanding advantages of the present invention are: the measurement accuracy of the present invention is not affected by the precision of the turntable, based on the existing mechanical parts and numerical control system of the gear processing machine tool, no additional measurement and control system is required, the measurement cost is low and the efficiency is high, and the pitch deviation can be measured the absolute value of . The invention has a wide range of applications and can be used on all gear processing machine tools (gear hobbing machines, gear milling machines and gear grinding machines, etc.).

Technical scheme of the present invention is:

An on-machine measuring device for pitch deviation of large gears of the present invention comprises a numerical control turntable 2, a bed 6, a radial numerical control sliding table 3, an axial numerical control sliding table 4 and an indicator 5 touching the tooth surface, and also includes Electrical device and numerical control system, the gear 1 is clamped on the numerical control turntable 2, moves together with the C-axis of the numerical control turntable 2, the indicator 5 is fixed on the axial numerical control slide The X-axis of table 3 and the Z-axis of axial numerically controlled sliding table 4 move together, and the X-axis, Z-axis and C-axis movements of the machine tool are all controlled by the electrical device and the numerical control system of the machine tool.

The indicator 5 is two dial gauges.

An on-machine measurement method for large gear tooth pitch deviation of the present invention,

a) Steps including erection of indicator 5:

a1. Contact the probes of the two indicators 5 with the adjacent tooth surfaces on the same side, and the probes of the indicator 5 and the tooth surfaces are in contact with approximately the same area on the tooth surface;

a2. Estimate the cumulative deviation of the tooth pitch and the positioning accuracy of the turntable, and the control indicator has sufficient pre-compression;

a3. The adjacent tooth surface that is in contact with the measuring head of the indicator 5 is roughly on the straight line that passes through the center of rotation of the turntable and is parallel to the direction of movement of the radial CNC slide table;

a4. The movement direction of the touch probe of the indicator 5 is roughly perpendicular to the tooth surface of the gear;

b) including the step of measuring the position of the tooth surface:

b1. Set up two indicators 5 according to the requirements in step a, so that the measuring head of the indicator 5 is in contact with the right tooth surface. At this time, record the coordinates of the turntable as C ₁ , and the coordinates of the radial CNC sliding table as X ₁ .

b2. Rotate the CNC turntable 2 by an angle C _m along the direction where the measuring head of the indicator 5 is away from the tooth surface, so that the two indicators 5 are separated from the tooth surface. C _m =360/z _g /8, m _n is the modulus of the normal surface, and β is the helix angle of the indexing circle;

b3. Rotate the CNC turntable 2 by an angle C _m along the measuring head of the indicator 5 close to the tooth surface, the two indicators 5 will touch the tooth surface, and record the readings of the two meters as v _11R and v _12R respectively;

b4. Rotate the CNC turntable 2 by an angle C _m along the measuring head of the indicator 5 away from the tooth surface, so that the two indicators 5 are separated from the tooth surface;

b5. Move the radial numerical control sliding table 3 away from the gear axis for a distance X _m , and the indicator 5 exits the tooth slot, X _m =4*m _n .

b6. Turn the CNC turntable 2 forward to an angle of 360/z _g , where z _g is the number of gear teeth;

b7. Move the radial numerically controlled sliding table 3 along the direction close to the axis of the gear 1 for a distance of X _m , and the indicator 5 enters the tooth groove;

b8. Rotate the CNC turntable 2 by an angle C _m along the direction where the measuring head of the indicator 5 approaches the tooth surface, so that the two indicators 5 contact the tooth surface. Record the readings of the two indicators as v _21R and v _22R respectively;

b9. Repeat step b4 to step b8, and the recorded readings of indicator 5 are v _i1R , v _i2R , i=1, 2,..., z _g ;

b10. Repeat steps b1 to b9, set up the meter again to measure the left tooth surface, and the measured indicator (5) reads v _i1L , v _i2L , i=1,2,...,z _g ;

c) Calculation steps including single pitch deviation:

c1. Calculate the indicator reading difference corresponding to the theoretical single tooth pitch on the right tooth surface, v ₂₁₀ =sum{v _i2R -v _i1R ,i=1,2,…,z _g }/z _g ;

c2. Calculate the single tooth pitch deviation of the right tooth surface, f _ptiR =(v _i2R -v _i1R -v ₂₁₀ )/cos(β),i=1,2,…z _g , β is the pitch circle helix angle of the gear;

c3. Repeat step c1 and step c2 to calculate the single pitch deviation f _ptiL of the left tooth surface;

d) Calculation steps including accumulative pitch deviation:

d1. Calculate the single pitch deviation of the right tooth surface, F _piR =f _pt1R +f _pt2R +…+f _ptiR ,i=1,2,…,z _g -1;

d2. Repeat d1 to calculate the single pitch deviation F _piL of the left tooth surface.

The amount of pre-compression in step a2 is greater than the sum of 3 times the cumulative total deviation of the tooth pitch and the arc length of the addendum corresponding to the positioning accuracy of the turntable.

The beneficial effects of the present invention are:

The on-machine measurement device and method for large gear pitch deviation of the present invention are completely based on the existing mechanical structure and control system of the gear processing machine tool, and can complete the measurement of pitch errors with low cost and high precision.

The measurement accuracy of the invention is less affected by the positioning accuracy of the turntable and the radial numerical control sliding table, and the accuracy of ordinary machine tools can fully meet the measurement requirements.

The on-machine measuring device and method for large gear tooth pitch deviation of the present invention can measure the absolute value of the tooth pitch deviation instead of the relative value, and the measurement result is more accurate.

The on-machine measurement method of large gear tooth pitch deviation is simple and reliable, the device is convenient to operate, and has a high degree of automation. The whole process can be realized by a numerical control system, and the operator only needs to record the reading.

The on-machine measuring method for large-scale gear pitch deviation can be applied to all gear processing machine tools, and has the advantage of wide application range.

Description of drawings

Fig. 1 is a schematic diagram of the on-board measurement device of the present invention.

Fig. 2 is a schematic diagram of the setting method of the indicator at the beginning of the measurement.

Fig. 3 Schematic diagram of the step-by-step measurement process of the right tooth surface.

In the figure: 1 is the gear, 2 is the CNC turntable, 3 is the radial CNC slide table, 4 is the axial CNC slide table, 5 is the indicator, 6 is the bed.

detailed description

The present invention will be further described below in conjunction with accompanying drawing:

Figure 1 shows a schematic diagram of the on-machine tooth pitch measuring device. This device is composed of a CNC turntable 2, a bed 6, a radial CNC slide table 3, an axial CNC slide table 4, an indicator 5, an electrical device, and a CNC system. The gear 1 is clamped on the CNC turntable 2, and moves together with the C-axis of the CNC turntable 2. The indicator 5 is fixed on the axial numerical control slide table 4 with a magnetic watch base, and moves together with the X axis of the radial numerical control slide table 3 and the Z axis of the axial numerical control slide table 4 . The X-axis, Z-axis and C-axis movements of the machine tool are all controlled by the CNC system of the machine tool.

Before the measurement starts, the indicator needs to be erected according to the method shown in Figure 2. In order to improve the measurement accuracy, the requirements that need to be met are: the probe is in contact with approximately the same area on the two tooth surfaces; the two probes have sufficient pre-compression to avoid the situation that the probe cannot touch the tooth surface during measurement; The two initial contact tooth surfaces are roughly symmetrically distributed with respect to the center line of the machine tool; when the probe touches the tooth surfaces, the movement direction of the probe is roughly perpendicular to the tooth surfaces.

Then, by programming the G code numerical control program, the machine tool is controlled to run according to the measurement process shown in Figure 3. In Figure 3, A, B, and C represent three adjacent teeth. The measurement process is as follows:

b1. Before the measurement starts, set up two dial indicator indicators as shown in Figure 2, so that the measuring head of the indicator is in contact with the right tooth surface. Record the coordinates of the turntable at this time as C ₁ , and the coordinates of the radial CNC sliding table as X ₁ .

b2. The turntable is rotated by an angle C _m along the direction that the measuring head is away from the tooth surface, so that the two indicators are separated from the tooth surface. C _m =360/z _g /8, m _n is the normal modulus, and β is the pitch circle helix angle.

b3. Turn the turntable to rotate angle C _m along the direction of the measuring head approaching the tooth surface, the two indicators will touch the tooth surface, and record the readings of the two meters as v _11R and v _12R respectively. b2 and b3 are to reduce the random error of the first measurement.

b4. The turntable is rotated by an angle C _m along the direction that the measuring head is away from the tooth surface, so that the two indicators are separated from the tooth surface.

b5. The radial CNC sliding table moves a distance of X _m away from the gear axis, and the indicator exits the tooth groove. X _m =4*m _n .

b6. The forward rotation angle of the turntable is 360/z _g , where z _g is the number of gear teeth.

b7. The radial CNC slide table moves a distance of X _m along the direction close to the gear axis, and the indicator enters the tooth groove.

b8. The turntable is rotated by an angle C _m along the direction that the measuring head is close to the tooth surface, so that the two indicators touch the tooth surface. Record the readings of the two indicators as v _21R and v _22R respectively.

Then step b4 to step b8 are repeated, and the recorded indicator readings are respectively v _i1R , v _i2R , i=1, 2, . . . , z _g . In the same way, the indicator can be re-installed to measure the left tooth surface, and the measured indicator readings are v _i1L , v _i2L , i=1,2,...,z _g .

b8, the recorded indicator readings are v _i1R , v _i2R , c1. First calculate the difference of the indicator readings corresponding to the theoretical single tooth pitch on the right tooth surface, v ₂₁₀ =sum{v _i2R -v _i1R ,i=1,2 ,…,z _g }/z _g .

c2. Then calculate the single pitch deviation of the right tooth surface, f _ptiR =(v _i2R -v _i1R -v ₂₁₀ )/cos(β),i=1,2,…z _g . β is the helix angle of the gear indexing circle.

c3. Repeat c1 and c2 to calculate the single pitch deviation f _ptiL of the left tooth surface.

d1. Calculate the single pitch deviation of the right tooth surface, F _piR =f _pt1R +f _pt2R +…+f _ptiR ,i=1,2,…,z _g -1.

d2. Repeat d1 to calculate the single pitch deviation F _piL of the left tooth surface.

The above-described embodiments are only described to the preferred implementation of the present invention, and are not intended to limit the concept and scope of the present invention. Under the premise of not departing from the design concept of the present invention, ordinary engineers and technicians in the field can make technical solutions of the present invention. The various modifications and improvements should fall within the protection scope of the present invention, and the technical content claimed in the present invention has been fully recorded in the claims.

Claims (3)

1. An on-machine measuring device for pitch deviation of large gears, characterized in that it comprises a CNC turntable (2), a bed (6), a radial CNC slide (3), an axial CNC slide (4) and gears The indicator (5) touched by the surface also includes an electrical device and a numerical control system. The gear (1) is clamped on the numerical control turntable (2), and moves together with the C-axis of the numerical control turntable (2). The indicator (5) Fixed on the axial CNC slide table (4) with a magnetic base, along with the X axis of the radial CNC slide table (3) and the Z axis of the axial CNC slide table (4) moving together, the X axis, Z axis of the machine tool The movement of the axis and the C axis is controlled by the electrical device and the numerical control system of the machine tool; the indicators (5) are two dial gauges. 2. An on-machine measurement method for pitch deviation of large gears, characterized in that: a) Steps including erection of indicator (5): a1. Put the probes of the two indicators (5) in contact with the adjacent tooth surfaces on the same side, and the probes of the indicators (5) and the tooth surfaces are in contact with approximately the same area on the tooth surface; a2. Estimate the cumulative deviation of the tooth pitch and the positioning accuracy of the turntable, and the control indicator has sufficient pre-compression; a3. The adjacent tooth surface that is in contact with the measuring head of the indicator (5) is roughly on a straight line passing through the center of rotation of the turntable and parallel to the direction of movement of the radial CNC slide table; a4. The movement direction touched by the measuring head of the indicator (5) is roughly perpendicular to the tooth surface of the gear; b) including the step of measuring the position of the tooth surface: b1. Set up two indicators (5) according to the requirements in step a, so that the measuring head of the indicator (5) is in contact with the right tooth surface. At this time, the coordinates of the recording turntable are C ₁ , and the coordinates of the radial CNC sliding table are X1 _; b2. Rotate the CNC turntable (2) along the measuring head of the indicator (5) away from the tooth surface by an angle C _m so that the two indicators (5) are separated from the tooth surface; C _m =360/z _g /8, m _n is the modulus of the normal surface, and β is the helix angle of the indexing circle; b3. Rotate the CNC turntable (2) by an angle C _m along the measuring head of the indicator (5) close to the tooth surface, the two indicators (5) will touch the tooth surface, and record the readings of the two meters as v _11R , v _12R ; b4. Rotate the numerical control turntable (2) along the measuring head of the indicator (5) away from the tooth surface by an angle C _m so that the two indicators (5) are separated from the tooth surface; b5. Move the radial CNC slide table (3) away from the gear axis for a distance of X _m , and the indicator (5) exits the tooth slot, X _m = 4*m _n ; b6. Turn the CNC turntable (2) forward to an angle of 360/z _g , where z _g is the number of gear teeth; b7. Move the radial CNC slide table (3) along the direction close to the axis of the gear (1) for a distance of X _m , and the indicator (5) enters the tooth groove; b8. Rotate the CNC turntable (2) by an angle C _m along the direction where the measuring head of the indicator (5) approaches the tooth surface, so that the two indicators (5) touch the tooth surface; record the readings of the two indicators as v _21R , v _22R ; b9, repeat step b4 to step b8, the recorded indicator (5) readings are respectively v _i1R , v _i2R , i=1,2,...,z _g ; b10. Repeat step b1 to step b9, set up the meter again to measure the left tooth surface, and measure the reading of the indicator (5) as v _i1L , v _i2L , i=1,2,...,z _g ; c) Calculation steps including single pitch deviation: c1. Calculate the indicator reading difference corresponding to the theoretical single tooth pitch on the right tooth surface, v ₂₁₀ =sum{v _i2R -v _i1R ,i=1,2,...,z _g }/z _g ; c2. Calculate the single pitch deviation of the right tooth surface, f _ptiR = (v _i2R -v _i1R -v ₂₁₀ )/cos(β), i=1,2,...z _g , β is the helix angle of the gear pitch circle; c3. Repeat step c1 and step c2 to calculate the single pitch deviation f _ptiL of the left tooth surface; d) Calculation steps including the cumulative deviation of the tooth pitch: d1. Calculate the single pitch deviation of the right tooth surface, F _piR = f _pt1R + f _pt2R +...+f _ptiR , i=1,2,..., z _g -1; d2. Repeat d1 to calculate the single pitch deviation F _piL of the left tooth surface. 3. The on-machine measurement method for pitch deviation of large gears according to claim 2, characterized in that the amount of pre-compression in the step a2 is greater than 3 times of the cumulative total deviation of the pitch and the positioning accuracy of the turntable corresponds to the arc length of the addendum sum.