CN112033303B - Device for measuring roundness and straightness of deep hole - Google Patents

Abstract

The invention relates to a deep hole roundness and straightness measuring device, comprising a fixed cylinder with a first through hole at the axis position, a connecting shaft, a laser displacement sensor, a two-dimensional position sensitive sensor, an inclination sensor, a drive motor and a motor support block , the first through hole is fixedly connected to the motor support block, the two-dimensional position sensitive sensor and the inclination sensor are fixed on the motor support block, and the two-dimensional position sensitive sensor and the inclination sensor are both located outside the first through hole; the drive motor is fixedly connected to the first through hole. A motor support block in a through hole; the connecting shaft is located at the end of the first through hole, and one end of the connecting shaft is connected to the drive motor, and the other end is fixedly connected to a mounting frame, and the laser displacement sensor is fixedly connected to the mounting frame. The device solves the problem of low measurement accuracy of the measurement device in the prior art, keeps the measurement device coaxial with the deep hole parts, reduces vibration interference during the measurement process, and further improves the measurement accuracy of the roundness and straightness of the deep hole.

Description

A deep hole roundness and straightness measuring device

technical field

The invention relates to the technical field of deep hole detection, in particular to a deep hole roundness and straightness measuring device.

Background technique

The machinery manufacturing industry generally refers to the inner hole with an aspect ratio of more than 10 as a deep hole. Deep hole machining is complex and special. In addition to the special requirements for tools and processing methods, problems such as difficult observation of machining parts and tool status, difficulty in chip removal, and difficulty in conveying coolant lead to poor hole axis straightness in deep hole parts. Due to the poor surface processing quality and other phenomena, the straightness and roundness of deep space parts are very important to the quality of the product. At present, the commonly used straightness measurement methods include optical axis method, ultrasonic wall thickness measurement method, and induction gauge strain gauges. The commonly used roundness measurement methods include the three-point method and the two-step method. Although the measurement theory has become more and more perfect, there are few actual products for straightness and roundness measurement, especially those that integrate the simultaneous measurement of straightness and roundness. products are even rarer.

Chinese patent document CN110160462A discloses a method for detecting roundness and straightness in the boring process of large-scale deep-hole parts. First, a detection system for roundness and straightness of large-scale deep-hole parts is constructed. There are two beams of light, one beam returns to the laser displacement sensor along the original optical path, and the other beam is irradiated on the position-sensitive detector through the beam splitter. The laser displacement sensor and the position-sensitive detector transmit the collected information to the data in real time. The acquisition card is then processed by the data storage module and the preprocessing module, and finally the measured roundness and straightness errors are evaluated in the error evaluation module. In this method, the roundness and straightness evaluation system is fixed on the tool shank, and during the operation of the tool shank, since the end of the tool shank is suspended, vibration will be generated during the rotation of the tool shank, which will affect the measurement results and reduce the measurement accuracy.

Chinese patent document CN110160464A discloses a device for measuring the cylindricity of an inner hole and a method of using the same. Through the first detection rod, the second detection rod and the third detection rod in different measurement sections, the measurement value is obtained, and the roundness error of the measured inner hole on the measurement section is calculated, and according to the first detection at each measurement section The measurement values of the rod, the second detection rod, the third detection rod and the inclination sensor are used to calculate the straightness error of the center line of the inner hole to be measured. The straightness error of the measured inner hole can be calculated to obtain the cylindricity error. In the device, the detection rod is suspended and fixed in the hole to be measured, and when the hole depth is large, the corresponding detection rod needs to be lengthened.

SUMMARY OF THE INVENTION

In view of the above problems in the prior art, the present invention discloses a deep hole roundness and straightness measuring device, which solves the problem of low measurement accuracy of the measuring device in the prior art, keeps the measuring device and the deep hole parts coaxial, reduces the The vibration interference during the small measurement process further improves the measurement accuracy of the roundness and straightness of the deep hole.

The principle of roundness measurement is to use a laser displacement sensor to measure a certain deep hole section, and the relative coordinates of the measured section profile in a relative coordinate system can be obtained. After the coordinate transformation, it can be converted into the actual coordinates in the absolute coordinate system, and the actual coordinates of the measured section profile can be obtained. The roundness error can be obtained by existing roundness evaluation methods, such as minimum area method and least squares circle method.

The principle of straightness measurement is to use the least squares method to fit the relative coordinates of the measurement interface profile to obtain a fitted circle. The center of the fitted circle is regarded as the center of the section of the deep hole to be measured, and the center of the section circle in the relative coordinate system can be obtained. The coordinates below are converted to the actual coordinates in the absolute coordinate system by the coordinates. On the basis of determining the actual coordinates of the center of the deep hole section, connect the center of each deep hole section in turn, and regard the obtained curve as the actual axis of the deep hole. After the actual axis of the deep hole is obtained, a cylindrical surface with the smallest diameter that can cover the actual axis is fitted, and the diameter of the cylindrical surface is the straightness of the deep hole to be measured.

The specific technical solution disclosed by the present invention is as follows: a deep hole roundness and straightness measuring device, comprising a fixed cylinder with a first through hole at an axis position, a connecting shaft, a laser displacement sensor, a two-dimensional position sensitive sensor, an inclination angle a sensor, a drive motor and a motor support block, one end of the motor support block is fixedly connected to the first through hole, and the other end of the motor support block protrudes out of the first through hole; the two-dimensional position sensitive sensor is related to the inclination angle The sensor is fixed on the motor support block, and the two-dimensional position sensitive sensor and the inclination sensor are both located outside the first through hole; the drive motor is located in the first through hole, and the drive motor is fixedly connected to the motor support block; the connection The shaft is located at the end of the first through hole, one end of the connecting shaft is connected to the driving shaft of the driving motor, and the other end of the connecting shaft is fixedly connected with a mounting frame, and the laser displacement sensor is fixedly connected to the mounting frame.

Further, a reducer is arranged between the connecting shaft and the drive motor, the input shaft of the reducer is fixedly connected with the drive shaft of the drive motor, and the output shaft of the reducer is fixedly connected with the connecting shaft.

Further, a bearing mechanism is provided on the connecting shaft, the bearing mechanism includes a bearing, a bearing fixing sleeve, an end cover and a bearing locking nut, and the bearing fixing sleeve is fixedly connected in the first through hole; the The bearing is located inside the bearing fixing sleeve, the bearing locking nut is screwed with the connecting shaft, the end cover is fixedly connected with the end of the fixing cylinder, and the bearing is fixed on the connecting shaft through the bearing locking nut and the end cover.

Further, a proximity switch is provided on the end face of the fixing cylinder close to the connecting shaft, a positioning piece is fixedly connected to the mounting frame, and the proximity switch outputs an electrical signal every time the positioning sheet rotates along the axis of the fixing cylinder once.

Further, the outer surface of the fixed cylinder is evenly provided with a plurality of groups of supporting running mechanisms along the circumferential direction, and the axis extension line of the supporting running mechanisms intersects with the axis of the fixed cylinder.

Further, the supporting walking mechanism includes a spring, a universal ball, a supporting outer cylinder, a first gasket and a second gasket, the supporting outer cylinder is provided with a fixed blind hole, and the bottom of the fixed blind hole is provided with the second through hole; the first gasket is located at the bottom of the fixed blind hole, the second gasket is located at the opening of the fixed blind hole, and the second gasket is threadedly connected to the fixed blind hole; the spring is located in the fixed blind hole Between the first washer and the second washer in the blind hole, one end of the spring is fixedly connected to the first washer, and the other end is fixedly connected to the second washer; the universal ball includes a sphere and a fixed seat, the sphere It is fitted at one end of the fixed seat, and the ball can be rotated in any direction, and the other end of the fixed seat is fixedly connected to the first gasket through the second through hole.

Further, the axis of the first through hole coincides with the axis of the drive shaft on the drive motor, the axis of the input and output shafts on the reducer, and the axis of the connecting shaft.

Further, a laser transmitter is also included, the laser transmitter is located on the side of the fixed cylinder close to the two-dimensional position-sensitive sensor, and is used to provide a light source for the two-dimensional position-sensitive sensor.

Compared with the prior art, the present invention has the following advantages:

1) The measuring device in the present invention integrates a laser displacement sensor, a two-dimensional position sensitive detector and an inclination sensor, which can simultaneously measure the roundness and straightness of the deep-hole parts in one measurement process, with high measurement efficiency, and through multiple sensors. It can further improve the accuracy of the measurement results and improve the measurement accuracy.

2) In the present invention, the measuring device is provided with a bearing mechanism and a supporting traveling mechanism, and the connecting shaft is coaxially fixed by the bearing mechanism, so as to avoid the shaking of the connecting shaft, and the measuring device and the deep hole parts are kept coaxial by the supporting traveling mechanism, and the moving process is The moving resistance of the middle measuring device is small, which reduces the vibration during the moving process, thereby improving the measurement accuracy.

Description of drawings

1 is a structural diagram of a deep hole roundness and straightness measuring device in an embodiment of the present invention;

Fig. 2 is the structure diagram of supporting traveling mechanism in the embodiment of the present invention;

3 is a schematic diagram of the arrangement of the supporting traveling mechanism along the circumferential direction of the fixed cylinder in the embodiment of the present invention;

Detailed ways

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

It should be understood that the "upper", "lower", "inner", "outer" and other orientations claimed in the present invention are described based on the "upper", "lower", "inner" and "outer" orientations in the drawings, which are only for convenience of description. , cannot limit the structure obtained in the present invention.

Furthermore, the terms "first" and "second" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" and "second" may expressly or implicitly include one or more of that feature.

Example:

1-3, a deep hole roundness and straightness measuring device disclosed in this embodiment includes a fixed cylinder 13 with a first through hole at the axial position, a connecting shaft 2, and a laser displacement sensor 1, 2 Dimensional position sensitive sensor 7, inclination sensor 8, drive motor 6 and motor support block 11, one end of the motor support block 11 is fixedly connected to the first through hole through a connecting bolt 12, and the other end of the motor support block 11 extends out of the first through hole; the two-dimensional position sensitive sensor 7 and the inclination sensor 8 are fixed on the motor support block 11, and the two-dimensional position sensitive sensor 7 and the inclination sensor 8 are both located outside the first through hole; the drive motor 6 is located in the first through hole, and the drive motor 6 is fixedly connected to the motor support block 11; the connecting shaft 2 is located at the end of the first through hole, and one end of the connecting shaft 2 is connected with the reducer 5, the The input shaft of the reducer 5 is fixedly connected with the drive shaft of the drive motor 6 , the output shaft of the reducer 5 is fixedly connected with the connecting shaft 2 , and the other end of the connecting shaft 2 is fixedly connected with a mounting frame 18 , which is fixed on the mounting frame 18 Connect the laser displacement sensor 1.

The connecting shaft 2 is used to connect the laser displacement sensor 1 and the reducer 5 on the one hand, transmit the torque of the driving motor 6 to the laser displacement sensor 1, and drive the laser displacement sensor 1 to measure the inner surface of the deep hole part; On the one hand, it is used to locate the position of the laser displacement sensor 1, so that the rotational movement axis of the laser displacement sensor 1 is coincident and fixed with the overall axis of the measuring device in the present invention, so as to avoid the small axial vibration caused by the rotation of the measuring device during the measurement process, which affects the measurement. result.

The connecting shaft 2 is provided with a bearing mechanism, the bearing mechanism includes a bearing 3, a bearing fixing sleeve 15, an end cover and a bearing locking nut 14, and the bearing fixing sleeve 15 is fixedly connected in the first through hole; The bearing 3 is located inside the bearing fixing sleeve 15, the bearing locking nut 14 is threadedly connected with the connecting shaft 2, the end cover is fixedly connected with the end of the fixing cylinder 13, and the bearing is fixed by the bearing locking nut 14 and the end cover. 3 is fixed on the connecting shaft 2. In this embodiment, the bearing 3 preferably adopts two angular contact ball bearings. Through the back-to-back installation method, the axial movement is reduced, the support angle rigidity in the radial and axial directions is increased, and the deformation resistance of the connecting shaft is improved. , which effectively avoids the influence of the deformation of the connecting shaft on the measurement results. At the same time, the cooperation of the bearing 3, the bearing fixing sleeve 15, the end cover and the bearing locking nut 14 ensures that the axes of the connecting shaft 2 and the fixing cylinder 13 coincide, and the axial direction of the connecting shaft 2 does not move, which further ensures the measurement accuracy.

A proximity switch 16 is provided on the end surface of the fixing cylinder 13 close to the connecting shaft, and a positioning piece 17 is fixedly connected to the mounting frame 18 . The positioning sheet 17 rotates along the axis of the fixing cylinder every one turn, and the proximity switch 16 outputs an electrical signal. , the electrical signal can participate in controlling the start and stop of the drive motor 6 . Since there are multiple data lines and power lines in the measuring device, the forward and reverse rotation of the drive motor can be alternately used to avoid line entanglement. Therefore, when the laser displacement sensor 1 rotates forward and reverse alternately for one week, there is a reverse gap in the forward and reverse rotation directions of the driving motor 6, that is, when the driving motor 6 actually rotates, the assembly gap needs to be eliminated first, and then the laser displacement sensor 1 can be driven to rotate. In order to ensure that the laser displacement sensor 1 accurately measures the cross-sectional profile of the deep hole, the positioning sheet 17 and the proximity switch 16 are used to record the actual rotation angle of the positioning laser displacement sensor 1 to eliminate the influence of backlash.

The outer surface of the fixing cylinder 13 is uniformly provided with a plurality of supporting traveling mechanisms 4 along the circumferential direction, and the axis extension line of the supporting traveling mechanisms 4 intersects the axis of the fixing cylinder 13 . In this embodiment, the fixing cylinder 13 is provided with two sets of supporting and walking mechanisms 4 along the axial direction, and each group of supporting and walking mechanisms 4 is arranged along the circumferential direction of the fixing cylinder 13 with three groups at intervals of 120°.

The supporting walking mechanism 4 includes a spring 44, a universal ball 41, a supporting outer cylinder 42, a first washer 43 and a second washer 45. The supporting outer cylinder 42 is provided with a fixed blind hole therein. The bottom is provided with a second through hole; the first gasket 43 is located at the bottom of the fixed blind hole, the second gasket 45 is located at the opening of the fixed blind hole, and the second gasket 45 is threaded with the fixed blind hole connection; the spring 44 is located between the first washer 43 and the second washer 45 in the fixed blind hole, and one end of the spring 44 is fixedly connected to the first washer 43, and the other end is fixedly connected to the second washer 45; so The universal ball 41 includes a ball and a fixed seat, the ball is fitted at one end of the fixed seat, and the ball can be rotated in any direction, and the other end of the fixed seat is fixedly connected to the first gasket 43 through the second through hole. During use, the universal ball 41 and the first washer 43 can slide along the supporting outer cylinder 42, and during the movement of the measuring device along the axis of the deep hole, the overall axis of the measuring device is kept coaxial with the axis of the deep hole through a plurality of supporting walking mechanisms 4. , reduce the deviation between the axis of the device and the center of the deep hole section, the rolling contact between the universal ball and the inner surface of the deep hole reduces the moving resistance of the measuring device, and the spring can reduce the vibration of the measuring device during the moving process and improve the measuring accuracy.

The axis of the first through hole coincides with the axis of the drive shaft on the drive motor 6 , the axis of the input and output shaft on the reducer 5 , and the axis of the connecting shaft 2 .

The laser transmitter 10 is also included. The laser transmitter 10 is located on the side of the fixed cylinder 13 close to the two-dimensional position sensitive sensor 7. During the test, the measuring device moves while the position of the laser transmitter 10 remains fixed. When the laser irradiates a certain point on the photosensitive surface of the two-dimensional position sensitive sensor 7, the transverse electric field causes the light to generate carriers to form currents flowing to the electrodes at both ends. When the position of the two-dimensional position sensitive sensor 7 changes, the light spot on the two-dimensional position sensitive sensor 7 moves between the two poles, and the output current signal of the output poles at both ends will also change accordingly. The light spot can be calculated according to the value of the current signal. The position coordinates of the two-dimensional position sensitive sensor 7 in space can be obtained. Since the two-dimensional position sensitive sensor 7 and the measuring device are fixed in position, the spatial position of the measuring device can be obtained indirectly.

In this embodiment, in order to facilitate the pulling of the measuring device, a connecting rope 19 and a fixed pulley 20 are provided on the side of the laser displacement sensor, and the connecting rope 19 and the fixed pulley 20 are located on the axis extension of the measuring device.

In the present invention, the laser displacement sensor 1 is used to scan the cross-sectional profile of the inner surface of the deep hole, and reflect the coordinate data of the measured cross-sectional profile; the two-dimensional position sensitive sensor 7 receives the laser light emitted by the laser transmitter outside the deep hole, Reflects the actual spatial position of the measuring device on the axis; the inclination sensor 8 uses the principle of angular momentum conservation of the built-in gyroscope to calculate the attitude of the inclination sensor in space, thereby reflecting the actual spatial attitude of the measuring device. The two parameters of the two-dimensional position sensitive sensor and the inclination sensor are obtained by the computer, so that the spatial pose of the measuring device can be inferred.

The working principle of the measuring device is as follows: First, select multiple measuring sections on the deep hole parts, so that the measuring device moves smoothly in the deep hole parts, and when a measuring section is reached, the device stops, and the driving motor drives the laser displacement sensor to measure the deep hole section profile. Scanning is performed to obtain the relative coordinates of the profile of the measurement section, while the two-dimensional position-sensitive sensor and the inclination sensor record the actual pose of the measurement device. After the section profile measurement is completed, according to the actual pose recorded by the two-dimensional position sensitive sensor and the inclination sensor, the computer is used to transform the collected data to obtain the actual coordinates of the measurement point in the absolute coordinate system.

Among them, the coordinate transformation method is:

Firstly, the relative coordinate system o'-x'y'z' is established with the center of the two-dimensional sensitive sensor in the measuring device as the origin. In the initial measurement state, the deep hole parts are fixedly connected to the ground at this time, and the measuring device is located in the deep hole but No measurement is performed, and the center of the two-dimensional position sensitive sensor in this state is used as the origin to establish an absolute coordinate system o-xyz. At this time, the relative coordinate system coincides with the absolute coordinate system.

随后绕y轴旋转角度θ，最后绕x轴旋转角度ψ，得到最终的坐标系。其变换矩阵可表示为：When the measuring device is located in the measuring section, the inclination sensor obtains the Euler angle of the measuring device, and its rotation sequence is set as zyx, that is, the relative coordinate system o'-x'y'z' first rotates the angle around the z-axis

Then rotate the angle θ around the y-axis, and finally rotate the angle ψ around the x-axis to obtain the final coordinate system. Its transformation matrix can be expressed as:

in,

R_Y(θ)、R_X(ψ)均为基本变换矩阵。

Both R _Y (θ) and R _X (ψ) are basic transformation matrices.

Suppose the displacement variation of the measuring device obtained by the two-dimensional position sensitive sensor is (a, b), the distance moving along the axis direction is c, and the horizontal distance between the center of the photosensitive surface of the two-dimensional position sensitive sensor and the laser emission hole on the laser displacement sensor is l. Assume that the relative coordinates of the measurement point on the cross-sectional profile measured by the laser displacement sensor are (x', y', z'), and the actual coordinates of the measurement point corresponding to the absolute coordinate system o-xyz are (x, y, z). Since the relative coordinates (x', y', z') of the measurement point can be directly measured by the laser displacement sensor, the absolute coordinates (x, y, z) of the measurement point can be obtained according to the transformation matrix:

In the roundness measurement process, the contour coordinate points around the section of the deep hole are obtained by the above method, and the roundness of the deep hole is obtained by the minimum area method, the least squares circle method or other roundness evaluation methods. For example, the least squares circle method: take the center of the circle with the smallest sum of the squares of the distances from each measurement point to the circumference on the profile of the deep hole as the center of the circle, and the radius difference of the two concentric circles covering the profile of the deep hole is the diameter of the deep hole part. roundness.

In the process of straightness measurement, first use the above method to measure the coordinate points of a plurality of deep hole cross-sectional profiles, each deep hole cross-sectional profile is fitted with a circle using the least squares method, and the center of the fitted circle is used as the current deep hole cross-sectional profile. After obtaining the absolute coordinates of the center of the contour of each deep hole interface through coordinate conversion, connect the circle centers of the cross-sectional contours of each deep hole in turn, and the obtained curve is the actual axis of the deep hole part. By fitting the actual axis, the smallest diameter is obtained. And can cover the cylindrical surface of the actual axis, the cylindrical surface is the straightness of the measured deep hole parts.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims (5)

1. a deep hole roundness and straightness measuring device, is characterized in that, comprises the fixed cylinder that the axis position is provided with the first through hole, the connecting shaft, the laser displacement sensor, the two-dimensional position sensitive sensor, the inclination sensor, the drive motor and a motor support block, one end of the motor support block is fixedly connected in the first through hole, and the other end of the motor support block protrudes out of the first through hole; the two-dimensional position sensitive sensor and the inclination sensor are fixed on the motor support block The two-dimensional position sensitive sensor and the inclination sensor are both located outside the first through hole; the drive motor is located in the first through hole, and the drive motor is fixedly connected to the motor support block; the connecting shaft is located in the first through hole The end of the hole, and one end of the connecting shaft is connected to the driving shaft of the driving motor, and the other end of the connecting shaft is fixedly connected with a mounting frame, and the mounting frame is fixedly connected with the laser displacement sensor, the two-dimensional position sensitive sensor Able to receive the laser light emitted by the laser transmitter outside the deep hole, the inclination sensor has a built-in gyroscope; a reducer is arranged between the connecting shaft and the drive motor, and the input shaft of the reducer is fixedly connected with the drive shaft of the drive motor, The output shaft of the reducer is fixedly connected with the connecting shaft; the connecting shaft is provided with a bearing mechanism, the bearing mechanism includes a bearing, a bearing fixing sleeve, an end cover and a bearing locking nut, and the bearing fixing sleeve is fixed connected in the first through hole; the bearing is located inside the bearing fixing sleeve, the bearing locking nut is threadedly connected with the connecting shaft, the end cover is fixedly connected with the end of the fixing cylinder, and the bearing locking nut is connected with the end cover through the bearing locking nut. The bearing is fixed on the connecting shaft; the end face of the fixed cylinder close to the connecting shaft is provided with a proximity switch, the mounting frame is fixedly connected with a positioning piece, and the positioning piece rotates along the axis of the fixed cylinder every time, the proximity switch outputs one Electric signal, the drive motor runs alternately forward and reverse. 2 . The measuring device according to claim 1 , wherein the outer surface of the fixed cylinder is evenly provided with a plurality of groups of supporting walking mechanisms along the circumferential direction, and the axis extension line of the supporting walking mechanisms intersects the axis of the fixed cylinder. 3 . 3 . The measuring device according to claim 2 , wherein the supporting running mechanism comprises a spring, a universal ball, a supporting outer cylinder, a first gasket and a second gasket, and the supporting outer cylinder is provided with 3 . a fixed blind hole, the bottom of the fixed blind hole is provided with a second through hole; the first gasket is located at the bottom of the fixed blind hole, the second gasket is located at the opening of the fixed blind hole, and the second gasket is located at the bottom of the fixed blind hole; The plate is threadedly connected with the fixed blind hole; the spring is located between the first gasket and the second gasket in the fixed blind hole, and one end of the spring is fixedly connected to the first gasket, and the other end is fixedly connected to the second gasket; The universal ball includes a sphere and a fixing seat, the sphere is fitted at one end of the fixing seat, and the sphere can rotate in any direction, and the other end of the fixing seat is fixedly connected to the first gasket through the second through hole. 4 . The measuring device according to claim 3 , wherein the axis of the first through hole coincides with the axis of the drive shaft on the drive motor, the axis of the input and output shafts on the reducer, and the axis of the connecting shaft. 5 . 5 . The measuring device according to claim 4 , further comprising a laser transmitter, and the laser transmitter is located on the side of the fixed cylinder close to the two-dimensional position sensitive sensor. 6 .

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