CN101782374A - Gear and moulding structure outline measuring method based on template near-field light projection scanning - Google Patents

Abstract

Based on the profile measurement method of gear and forming structure based on template near-field light projection scanning, according to the shape of the gear to be tested, a template that is the same as the tooth or alveolar section of the gear to be tested is made; the template is placed in the tooth groove of the gear to be tested , and then install an illumination light source on one side of the template, and use the triangular relationship formed by the CCD or image sensor and the edge projection to obtain the contour data of the object surface; Measurement means the ability to completely measure the geometry and parameters of the entire gear. The invention can realize micron-level shadow projection, and furthermore, in the contour measurement of gears and other formed structures, the measurement accuracy along the surface normal direction will reach more than 5 microns. The horizontal resolution reaches above 20 microns, and the measurement speed reaches above 5000 points/second. Especially suitable for quality inspection of gear processing. This technique can also be used in the surface profile measurement of other structural parts.

Description

Profile measurement method of gears and forming structures based on template near-field light projection scanning

technical field

The invention belongs to a method for measuring a three-dimensional profile of an object surface, in particular to a method for measuring a profile of a gear and a molding structure based on template near-field light projection scanning.

Background technique

With the development of industry, more and more product manufacturing needs high-precision measurement methods and instruments to ensure the quality of products. Optical measurement methods have the advantages of non-contact, fast and high-precision measurement, and have been favored by researchers at home and abroad. Extensive attention and research, the main measurement methods are the measurement methods using contact three-coordinate measuring machine and laser triangulation technology, but although the three-coordinate measuring machine has high measurement accuracy, its measurement efficiency is low, especially for When measuring large objects such as large gears, due to the limitation of the measurement range, the measurement accuracy will be greatly reduced. At the same time, the error dispersion caused by the influence of the environment in the point-by-point measurement of the three-coordinate measuring machine is large, and it is difficult to compensate; and the laser Triangulation technology is affected by factors such as the spot size, the width of the light knife, and the influence of laser light scattering on the metal surface. Usually, the accuracy is lower than 50 microns. Therefore, the existing methods are difficult to meet the measurement requirements.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the above-mentioned existing technologies, and provide a method for measuring the profile of gears and forming structures using template projection. This method not only has high measurement speed, but also can ensure high measurement accuracy. In this field of measurement, it solves the technical problem of light knife refinement in laser triangulation measurement, and is especially suitable for quality inspection of gear processing. This technology can also be used in the surface profile measurement of other structural parts (such as: the inner and outer shapes of pipes, various profiles and blades, etc.).

In order to achieve the above object, the technical scheme adopted in the present invention is:

1) According to the shape of the gear to be tested, make a template 2 identical to the tooth or alveolar section of the gear to be tested;

2) Place the template with the same tooth section of the gear under test in the tooth groove of the gear under test or mesh the template with the same tooth groove section of the gear under test with the teeth of the gear under test, and then place the template on one side of the template Install an illumination source that projects the edge of the template or the knife edge or slit installed on the edge of the template onto the groove or tooth of the gear under test to form a clear projection of the edge or slit;

3) Install a CCD or an image sensor on the other side of the template, and use the triangular relationship formed between the CCD or the image sensor and step 2) edge projection to obtain the contour data of the object surface;

Or determine the distance between the edge of the template or the distance between the knife edge and the edge projection according to the image data obtained by the CCD or image sensor, and obtain the three-dimensional contour data measurement of the object surface;

4) For a complete tooth profile, then repeat step 3) to obtain a complete tooth profile by moving the template along the tooth groove of the gear and the measuring system composed of CCD or image sensor;

5) For each tooth on the gear, rotate the gear to be tested through the angular indexing encoding device and repeat steps 2)-4) to completely measure the geometry and parameters of the entire gear;

The illumination light source of the present invention adopts common light source or laser light source;

Before the measurement, the laser tracker is used to measure and calibrate the coordinates of the measurement system and the measured object.

The invention has a much higher measurement speed than the traditional three-coordinate measuring machine, and at the same time has a high measurement accuracy in the measurement of the profile of the forming structure, and solves the technical problem of light knife refinement in the laser triangulation measurement in this measurement field , the present invention can realize micron-level shadow projection, and then in the contour measurement of large gears and other formed structures, the measurement accuracy along the surface normal direction will reach more than 5 microns. The horizontal resolution reaches above 20 microns, and the measurement speed reaches above 5000 points/second. It is especially suitable for the quality inspection of large and huge gears, and this technology can also be used in the surface profile measurement of other structural parts (such as: internal and external shapes of pipes, various profiles and blades, etc.).

Description of drawings

Fig. 1, 2 are measurement schematic diagrams of the present invention;

Fig. 3 is a diagram of the measurement system of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, 2, 3, 1) according to the shape of the tested gear 1, make the same template 2 as the tooth or alveolar section of the tested gear 1;

2) Place the template 2 with the same tooth section of the gear under test 1 in the tooth groove of the gear under test (see Figure 1) or place the template 2 with the same tooth groove section of the gear under test on the teeth Engagement (see Fig. 2), this template is fixed on the mobile platform 4 above base 3, then installs illuminating light source on one side of template 2, and this illuminating light source will template 2 edge or be installed on the knife edge or the slit of template edge projection to On the groove or tooth of the gear under test, a clear edge or slit projection is formed;

3) CCD or image sensor 5 is installed on the mobile platform 4 of the base 3 on the other side of the template 2, and an optical triangulation measurement system is formed with the template optical projection device in step 2). The coordinates of the measurement system and the measured object are measured and calibrated; the triangular relationship formed by using the CCD or the image sensor 5 and the projection of the knife-edge edge projected onto the gear surface in step 2), the three-dimensional data of the gear profile can be obtained according to the principle of triangulation, and the This data is sent into computing machine 8 (seeing Fig. 3) and is processed and obtains the outline data of object surface;

Or determine the distance between the edge of the template or the edge of the knife and the projection of the edge of the knife edge projected onto the gear surface according to the image data obtained by the CCD or the image sensor, and send this data into the computer 8 for processing to obtain the three-dimensional profile data measurement of the object surface;

4) For a complete tooth profile, then repeat step 3) to obtain a complete tooth profile by moving the template along the tooth groove of the gear and the measuring system composed of CCD or image sensor;

5) For each tooth on the gear, rotate the measured gear 1 through the angular indexing encoding device 7 and repeat steps 2)-4) to completely measure the geometry and parameters of the entire gear.

Claims (3)

1. The method for measuring the profile of gears and molding structures based on template near-field light projection scanning, is characterized in that, comprising the following steps: 1) According to the shape of the gear to be tested (1), make a template (2) identical to the tooth or alveolar section of the gear to be tested (1); 2) Place the template (2) which is the same as the tooth section of the gear to be tested in the tooth groove of the gear to be tested or mesh the template (2) which is the same as the tooth groove section of the gear to be tested with the teeth of the gear to be tested, Then, an illumination source is installed on one side of the template, and the illumination source projects the edge of the template (2) or a knife edge or a slit installed on the edge of the template onto the groove or teeth of the tested gear to form a clear edge or slit projection; 3) installing a CCD or an image sensor (5) on the other side of the template (2), utilizing the triangular relationship formed between the CCD or the image sensor (5) and the edge projection in step 2), to obtain the contour data of the object surface; Or determine the distance between the edge of the template or the distance between the knife edge and the edge projection according to the image data obtained by the CCD or image sensor, and obtain the three-dimensional contour data measurement of the object surface; 4) For a complete tooth profile, then repeat step 3) to obtain a complete tooth profile by moving the template along the tooth groove of the gear and the measuring system composed of CCD or image sensor; 5) For each tooth on the gear, rotate the measured gear (1) through the angular indexing encoding device (7) and repeat steps 2)-4) to completely measure the geometry and parameters of the entire gear. 2. The method for measuring the profile of gears and molding structures based on template near-field light projection scanning according to claim 1, characterized in that: said illumination light source is a common light source or a laser light source. 3. The method for measuring the profile of gears and forming structures based on template near-field light projection scanning according to claim 1, characterized in that the coordinates of the measurement system and the measured object are measured and calibrated by a laser tracker before measurement.

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