CN104501763B - Novel measurement method of gear measurement center - Google Patents

Abstract

The invention relates to the field of precision testing technology and instruments, and in particular to a new measurement method for a gear measurement center. In the first step, the gear to be tested is installed on the rotating platform of the gear measurement center; in the second step, the rotating platform is controlled to rotate the gear to be tested To a proper position, the probe at the gear measurement center can extend into the tooth groove along the radial direction of the gear to be measured. The present invention overcomes the disadvantages of error amplification and difficulty in improving the measurement accuracy of the gear measurement center angle error, reduces the measurement error, improves the measurement accuracy, and at the same time, due to the shortened measurement path, the measurement efficiency is higher than that of the conventional gear measurement center measurement method improve.

Description

A New Measuring Method of Gear Measuring Center

technical field

The invention relates to the field of precision testing technology and instruments, in particular to a novel gear measuring center measuring method.

Background technique

Gear is the most important and most widely used transmission type in mechanical transmission. It has the advantages of accurate transmission ratio, compact structure and high transmission efficiency. Gears are divided into micro gears, conventional gears, large gears and extra large gears according to their size. The precision of the gear has a direct and serious impact on the noise and service life of the gear. Different application fields have different requirements for the precision of the gear, especially in the field of precision transmission, which has high requirements for the precision of the gear. In order to achieve high-performance, high-efficiency transmission and long service life of major equipment, users have put forward higher and higher requirements for the precision of oversized gears.

At present, for conventional gears, typical instruments for gear measurement include gear measurement centers and coordinate measuring machines, among which gear measurement centers are widely used due to their high measurement efficiency and high measurement accuracy. Small and medium-sized gear measurement centers generally adopt the electronic generation method, and large gear measurement centers generally adopt the electronic generation type tangential polar coordinate method or normal polar coordinate method. The tooth profile error measurement process of the gear measurement center using the electronic generation method is synthesized by the rotational motion of the gear and the linear motion of the probe. In the actual measurement process, especially for the measurement of large gears, due to the large radius of the gear, resulting in The angular error in the gear rotation process has a magnification effect, which limits the measurement accuracy of the gear measurement center.

For example, when the gear radius is 3000mm, an angle error of 1 second will cause a length measurement error of 15um, which directly affects the measurement accuracy of the gear measurement center. Therefore, it is necessary to design a new measurement method to improve the measurement accuracy of the gear measurement center. At the same time, the existing gear measurement center uses the generation method to realize the measurement of the gear involute tooth profile error and the helical error. During the measurement process, due to the large movement stroke of the tangential generation method, the measurement efficiency is relatively low. The existing large-scale gear measurement center adopts the radial generation method in some cases, which reduces the stroke of the linear motion of the probe, but the large-scale gear has a large mass and low motion control accuracy, which also affects the measurement accuracy.

Contents of the invention

Aiming at the problems existing in the prior art, a novel gear measurement center measurement method is provided which can overcome the disadvantage of magnifying the angle error in the prior art and improve the measurement accuracy.

The technical scheme adopted in the present invention is:

A new measurement method for a gear measurement center. The first step is to install the measured gear on the rotating platform of the gear measurement center; the second step is to control the rotating platform to rotate the measured gear to a suitable position, and the suitable position is the gear measurement center. The measuring head can extend into the tooth groove along the radial direction of the gear under test; the third step is to control the rotating platform to rotate the gear under test, and when the tooth surface of the gear under test contacts with the measuring head, stop the rotating platform, Construct the gear workpiece coordinate system, plan the tooth profile error measurement path according to the gear workpiece coordinate system; the fourth step, control the three-dimensional measurement platform of the gear measurement center to measure the tooth profile error along the tooth profile error measurement path, and control the probe to exit the gear after the measurement is completed. Groove; the fifth step is to control the rotating platform to rotate the gear to be tested to the position of the next tooth to be tested, and repeat the third and fourth steps above.

When measuring the helix error, in the third step, the helix error measurement path needs to be planned according to the gear workpiece coordinate system; in the fourth step, it is also necessary to control the three-dimensional measurement platform to measure the helix along the helix error measurement path Line error, after the measurement is completed, the probe is controlled to withdraw from the cogging.

As a preferred embodiment of the present invention, in the third step, the Z axis of the gear workpiece coordinate system is the rotation axis of the rotary platform, and the origin of the gear workpiece coordinate system is the intersection point of the lower end surface of the gear under test and the rotation axis of the rotary platform, X One of the axis and the Y axis is the line connecting the origin of the gear workpiece coordinate system to the starting point of the involute of the measured tooth surface on the lower end surface of the gear under test, and the other one of the X axis and the Y axis is constructed according to the principle of orthogonality of the coordinate system.

In summary, owing to adopting above-mentioned technical scheme, the beneficial effect of the present invention is:

1. Overcome the disadvantages of error amplification and difficulty in improving the measurement accuracy of the gear measurement center angle error, reduce the measurement error and improve the measurement accuracy.

2. For the measurement of large-mass gears, the measurement method adopted in the present invention does not require a rotating platform to move when measuring tooth profile errors and helix errors, which reduces measurement uncertainty.

Description of drawings

Figure 1 is a structural diagram of the gear measurement center

Figure 2 is the measurement principle diagram of the gear measurement center coordinate method

Figure 3 is the schematic diagram of tooth profile error measurement by tangential generation method

Figure 4 is the schematic diagram of tooth profile error measurement by radial generation method

Figure 5 is the schematic diagram of gear workpiece coordinate system and tooth profile path planning

Marks in the figure: 1-three-dimensional measuring platform, 2-rotary platform, 3-probe, 4-gear to be tested.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

The purpose of the present invention is to overcome the error amplification of the angle error of the gear measurement center and the disadvantages that the measurement accuracy is difficult to improve. On the basis of the existing gear measurement center, a three-dimensional scanning probe is used to propose a gear measurement center based on the Cartesian coordinate measurement method. Measurement methods.

A new measurement method for a gear measurement center, which is characterized in that it avoids the disadvantages of angle error amplification when the existing gear measurement center measures tooth profile errors and helical line errors, uses a three-dimensional scanning probe, and adopts a rectangular coordinate measurement method to measure the tooth profile error. The measurement with the helical line error reduces the tooth profile error measurement path using the tangential generation method and improves the measurement efficiency. For the measurement of large-mass gears, the measurement method adopted in the present invention does not require a rotating platform to move when measuring tooth profile errors and helix errors, thereby reducing measurement uncertainty.

In the present invention, the gear measurement center is used as a four-dimensional coordinate measuring machine, and the rotation axis of the gear measurement center is used as the rotation axis of the four-dimensional coordinate measurement machine. The gear is positioned in a suitable position by the rotating shaft, and then measured by the Cartesian coordinate measurement method through the three-dimensional measuring platform of the gear measuring center.

The specific process is realized as follows: 1) Install the measured gear workpiece on the rotating platform of the gear measurement center; 2) Control the rotating platform to rotate the measured gear to a suitable position, that is, the measuring head can extend into the gear along the radial direction of the gear. in the slot. 3) Control the rotating platform to rotate the gear to be tested. When the tooth surface to be tested contacts the probe, stop the rotating platform and construct the gear workpiece coordinate system. The preferred workpiece coordinate system in this embodiment is shown in Figure 5. The Z-axis of the gear workpiece coordinate system is the rotation axis of the rotating platform, the origin of the gear workpiece coordinate system is the intersection point between the lower end surface of the gear and the rotation axis, and the X-axis or Y-axis is the origin of the coordinate system to the starting point of the involute line of the measured tooth surface on the lower end surface of the gear. Construct the last axis according to the principle of orthogonality of the coordinate system. The tooth profile error measurement path and the helical error measurement path are planned according to the gear workpiece coordinate system. 4) Control the three-dimensional measurement platform to measure the tooth profile error along the tooth profile error measurement path, and control the three-dimensional measurement platform to measure the helix error along the helix error measurement path. 5) After the current tooth profile error measurement is completed, control the probe to withdraw from the tooth slot, and then control the rotating platform to rotate the measured gear to the next measured tooth position, repeat steps 3) and 4) to achieve tooth profile error and helical error measurement . 6) The measurement of tooth thickness error and tooth pitch is consistent with the measurement process of the conventional gear measurement center.

Describe the present invention in detail below with reference to accompanying drawing: As shown in Figure 1, gear measuring center comprises three-dimensional measuring platform 1, rotating platform 2, probe 3, and the measuring method of the present invention is: the first step, tested gear 4 is installed on on the rotating platform 2 of the gear measurement center; the second step is to control the rotating platform 2 to rotate the measured gear 4 to a suitable position, and the suitable position is that the probe 3 of the gear measurement center can extend along the radial direction of the measured gear 4 into the tooth groove; the third step is to control the rotating platform 2 to rotate the measured gear 4, and when the tooth surface of the measured gear contacts the probe, stop the rotating platform and build the gear workpiece coordinate system, and plan according to the gear workpiece coordinate system Tooth profile error measurement path; the fourth step, control the three-dimensional measurement platform 1 of the gear measurement center to measure the tooth profile error along the tooth profile error measurement path, and control the probe 3 to exit the tooth groove after the measurement is completed; the fifth step, control the rotating platform 2 Rotate the gear under test to the position of the next tooth under test, and repeat the third and fourth steps above.

When measuring the helix error, in the third step, the helix error measurement path needs to be planned according to the gear workpiece coordinate system; in the fourth step, it is also necessary to control the three-dimensional measurement platform to measure the helix along the helix error measurement path Line error, after the measurement is completed, the probe is controlled to withdraw from the cogging.

As shown in Fig. 5, in the third step, the Z-axis of the gear workpiece coordinate system is the rotation axis of the rotary platform, the origin of the gear workpiece coordinate system is the intersection of the lower end surface of the gear under test and the rotation axis of the rotary platform, and the X-axis and One of the Y axes is the line connecting the origin of the gear workpiece coordinate system to the starting point of the involute of the measured tooth surface on the lower end surface of the gear under test, and the other one of the X axis and the Y axis is constructed according to the principle of orthogonality of the coordinate system.

Figure 2 is the measurement principle diagram of the gear measurement center coordinate method. The upper right corner of the figure should be marked with "probe reading" below the horizontal axis of the two-dimensional coordinate diagram; Figure 3 is the principle diagram of the tooth profile error measurement by the tangential generation method. The left side of the horizontal axis of the dimensional coordinate diagram should be marked with "probe reading", and the length between the two dotted lines in the figure is the extension; "Probe reading" should be marked under the shaft; Figure 5 is a schematic diagram of the gear workpiece coordinate system and tooth profile path planning. The symbols in Fig. 2 to Fig. 5 are common symbols in the technical field of gears, and will not be repeated here again.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (4)

1. A novel gear measurement center measurement method is characterized in that the first step is to install the measured gear on the rotating platform of the gear measurement center; the second step is to control the rotation of the rotating platform to rotate the measured gear to a suitable position. The probe at the proper position, that is, the gear measurement center, can extend into the tooth groove along the radial direction of the gear under test; the third step is to control the rotating platform to rotate the gear under test, when the tooth surface of the gear under test contacts the probe Finally, stop the rotating platform, construct the gear workpiece coordinate system, and plan the tooth profile error measurement path according to the gear workpiece coordinate system; the fourth step, control the three-dimensional measurement platform of the gear measurement center to measure the tooth profile error along the tooth profile error measurement path, and complete the measurement Then control the measuring head to exit the tooth groove; the fifth step is to control the rotating platform to rotate the measured gear to the position of the next measured tooth, and repeat the third and fourth steps above. 2. The novel gear measurement center measurement method according to claim 1, characterized in that, in the third step, it is also necessary to plan the helical error measurement path according to the gear workpiece coordinate system; in the fourth step, it is also necessary to Control the three-dimensional measurement platform to measure the helix error along the helix error measurement path, and control the probe to exit the tooth groove after the measurement is completed. 3. according to claim 1 or 2 described novel gear measurement center measuring methods, it is characterized in that, in the 3rd step, the Z-axis of described gear workpiece coordinate system is the axis of rotation of the rotary platform, and the origin of the gear workpiece coordinate system is The intersection of the lower end surface of the gear under test and the rotation axis of the rotating platform, one of the X-axis and the Y-axis is the line connecting the origin of the gear workpiece coordinate system to the starting point of the involute line of the measured tooth surface on the lower end surface of the gear under test. The intersection principle constructs the other of the X-axis and the Y-axis. 4. The novel gear measurement center measurement method according to claim 1 or 2, characterized in that the measuring head is a three-dimensional scanning measuring head.