JPS6332308A - Method and device for measuring noncontact shape of crank shaft - Google Patents

Abstract

PURPOSE:To accurately measure the shape of a crank shaft to be measured in a short time, by arranging the shaft so that the reference line of a measurement reference body and the measurement sectional area of the crank shaft to be measured are in a plane perpendicular to the crank shaft to be measured are in a plane perpendicular to the scanning surface of an optical size measuring instrument and face each other across a gap. CONSTITUTION:The measurement reference body 16 is arranged so that its reference line 16A is in the plane 14 perpendicular (in X direction) to the beam scanning surface 12 of the optical size measuring instrument 10, and a holding means 20 holds the crank shaft 18 to be measured in the plane 14 opposite the line 16A across the gap 19 in a beam scanning direction (Y direction). Further, a moving means 22 which moves the means 20 and reference body 16 in the X direction and a detecting means 24 which detects their movement quantity are provided. Then, a measuring instrument 10 is driven to scan a light beam on the shaft 18 and the Y-directional size of the gap 19 between the shaft 18 and line 16A is measured. Further, the means 24 detects the X-directional position of the means 20 to find the X- and Y-directional positions of the outward shape line of the convex surface of the shaft 18 along the surface 14. Consequently, the outward shape line is easily found by providing an X-Y plotter, etc.

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD 1 This invention relates to a method and apparatus for non-contact shape measurement of a crankshaft for non-contact measurement of the shape of a crankshaft using a light beam such as a laser beam. [Prior Art] Conventionally, as a means for measuring the shape of a crankshaft 1 as shown in FIG. was. Furthermore, the measurements of the 8 portions 4 at the ends of the pins 2 and journal 3 were performed using a contour measuring device.

[Problems to be solved by the invention]

However, the above-mentioned conventional method for measuring the shape of a crankshaft using a roughness meter and a contour shape measuring device has the problem that it takes time to set up the measuring device and that only specific locations can be measured.

[Purpose of the invention]

The present invention has been made in view of the above conventional problems, and provides a non-contact shape measuring method and apparatus for a crankshaft, which allows the setting of a measuring instrument and a crankshaft to be measured to be performed easily and in a short time. The purpose is to provide Another object of the present invention is to provide a non-contact shape measuring method and device that can measure any position on a crankshaft.

[Means to solve the problem]

In the present invention, the reference line of the measurement reference body and the measurement cross section of the crankshaft to be measured are located in a plane perpendicular to the scanning plane of an optical dimension measuring device that scans the object to be measured in one direction with a light beam, and The measurement reference body and the crankshaft to be measured are arranged so that the reference line and the cross section to be measured of the crankshaft to be measured face each other with a gap in the scanning direction of the light beam, and the measurement! ! The gap is measured while at least the crankshaft to be measured of the crankshaft to be measured and the crankshaft to be measured is moved relative to the scanning plane of the light beam along the plane in a direction orthogonal to the scanning plane. In this way, the above objective is achieved. Also, an optical dimension measuring device that scans the object to be measured in one direction with a light beam, in a plane perpendicular to the beam scanning plane of the light beam, and in a direction substantially perpendicular to the beam scanning plane! i!
tl! 8i so that there is a line! a crankshaft holding means for holding the crankshaft to be measured such that the cross section to be measured faces the reference line with a gap in the beam scanning direction within the plane; and the crankshaft. A moving means for relatively moving at least the crankshaft holding means of the holding means and the measurement reference body along the plane in a direction perpendicular to the beam scanning plane; and a moving means for moving the crankshaft by the moving means. In the relationship between the movement detection means for detecting the relative diameter eiit of the holding means with respect to the beam scanning surface, and the position of the crankshaft to be measured based on the lζ movement m detected by this movement detection means, the optical The above object is achieved by configuring a non-contact shape measuring device for a crankshaft and a display device for displaying the dimensions of the gap on a dimension measuring device. Further, the above object is achieved by using a straight edge as the measurement reference body. Further, the reference line on the measurement reference body is defined as yr! of the crankshaft to be measured. The above object is achieved by using an imaginary shape line. Further, the above object is achieved by providing the measurement reference body integrally with the crankshaft holder.

[Effect]

In this invention, the light beam of the optical measuring instrument is
While scanning the gap between the reference line of the l1 body and the crankshaft to be measured, the scanning surface is moved relatively in the longitudinal direction of the crankshaft to be measured, and the dimensions of the gap at each position of the crankshaft to be measured are determined. is detected in relation to the position, and thereby the shape of the measurement cross section of the crankshaft to be measured is measured. Therefore, the shape of the crankshaft can be measured quickly and accurately without contact.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 3, this embodiment includes an optical dimension measuring instrument 10 that scans an object to be measured in one direction with a light beam, and an optical dimension measuring device 10 that scans an object to be measured in one direction with a light beam, and a ° measurement reference body 1 arranged so that the reference line 16A lies within the plane 14 and in a direction substantially orthogonal to the beam scanning plane 12;
6 and the crankshaft 18 to be measured, the cross section to be measured is
a crankshaft holding means 20 which is held so as to face the reference line 16A in the beam scanning direction (Y direction) with a gap 19 within the plane 14, and this crankshaft holding means 20 and the measurement reference body 16; a moving means 22 for relatively moving along the plane 14 in a direction (X direction) perpendicular to the beam scanning surface 12;
A moving table detecting means 24 detects the relative movement of the crankshaft holding means 20 with respect to the beam scanning surface 12 by the moving means 22, and a moving table detecting means 24 detects the relative movement of the crankshaft holding means 20 with respect to the beam scanning surface 12. A non-contact crankshaft shape measuring device is constituted by a display 26 that displays the dimension of the gap 19 measured by the optical dimension measuring device 1o in relation to the position of the measuring crankshaft 18. The measurement reference body 16 is a straight reference body, and its reference line 16A is a straight edge, and the plane 1
4, in a direction (X direction) perpendicular to the beam scanning direction. Further, this measurement reference body 16 is fixed on a moving table 30 via two support posts 28. The crankshaft holding means 20 is mounted on the moving table 30 at a position between the support posts 28 and below the measurement reference body 16 in the figure.
There is. The movable table 30 moves along a guide 32 disposed under the movable table 30 to perform the measurement! ! It is supported so as to be able to reciprocate in a direction parallel to the straight reference line 16A in the quasi-body 16. Reference numeral 34 in FIG. 1 indicates a guide roller disposed between the guide 32 and the moving table 30. As shown in FIG. The moving means 22 includes a feed screw 22 disposed at a lower position of the moving table 30 along a guide 32.
A, a nut 22B attached to the lower surface of the moving table 3o and screwed into the feed screw 22A, and a drive motor 2 for driving the feed screw 22A.
It is composed of 2C. Said transfer 14IllfJ! The i-detecting means 24 is composed of a linear encoder placed on the side of the moving table 30. That is, the movement 1effl detection means 24, which is a linear encoder, is attached to one side of the moving table 30 in a direction parallel to the straight reference line 16A in the measurement reference body 16 (
The index scale 24B is fixed on a base 36 facing the optical scale 24A, and is caused by the overlapping of the optical gratings formed on these scales. It outputs a signal according to the number of repetitions of brightness and darkness. Therefore, each time the number of signals is counted, the moving foot of the optical scale 24A becomes
This is to detect the movement a in the direction. That is, the movement of the moving table 30 detected by the movement detecting means 24 is output as a pulse number to a counting circuit 38, as shown in FIG. The optical dimension measuring device 10 includes a light emitting device 10A and a light receiving device 10B. That is, a laser beam 42 is emitted from a laser tube 40 toward a fixed mirror 44 , and the laser beam 42 reflected by this fixed mirror 44 is converted into a rotating scanning beam 47 by a polygonal rotating mirror 46 . is converted into a parallel scanning beam 50 by the collimator lens 48 (the above is the light emitting device 1. OA side), and by this parallel scanning beam 50, 1! Il! The object to be measured is scanned at high speed, and from the length of time of dark or bright areas caused by the object,
This is to measure the dimension of the object to be measured in the scanning direction (Y direction). That is, the brightness of the parallel scanning beam 50 is determined by the light receiving device 10.
It is detected as a change in the output voltage of the light receiving element 56 located at the focal position of the condensing lens 52 on the B side, and the signal from the light receiving element 56 is input to the preamplifier 58, where it is amplified and then segment selected. The signal is sent to circuit 60. This segment selection circuit 60 generates a voltage (2) from the output voltage of the light receiving element 56 to open the gate circuit 62 only during the time t during which the object to be measured is being scanned, and outputs it to the gate circuit 62. ing. Since the clock pulse CP is inputted to the gate circuit 62 from the clock pulse oscillator 64, the clock pulse CP corresponding to the time t corresponding to the scanning direction dimension of the object to be measured, that is, the size of the gap 19 is inputted from the gate circuit 62. P is input to the counting circuit 66. The counting circuit 66 counts this clock pulse P and displays it on the display 26.
A counting signal is output to the display 26, and the size of the gap 19 is digitally displayed. On the other hand, the polygonal rotating mirror 46 generates a square wave that is amplified through a power amplifier 72 from a frequency divider 70 that divides the output of the clock pulse oscillator 64 into a square wave of approximately 400 to 800 square waves. It is rotated by a driven pulse motor 74 in synchronization with the clock pulse CP output from the clock pulse oscillator 64 to maintain measurement accuracy. Here, a counting circuit 38 for counting the detection value of the movement amount detecting means 24 is connected to the display 26 together with the counting circuit 66.
The display 26 outputs the dimension (or coordinates) of the gap 19 in the Y direction and the position (coordinates) of the beam scanning surface 12 in the lateral direction (X direction) with respect to the crankshaft 18 to be measured at this time. It's like that. Next, the crankshaft 18 to be measured is measured using the above embodiment device.
The case of measuring the shape of will be explained. As shown in FIGS. 1 and 2, the crankshaft 18 to be measured is placed on the crankshaft holding means 20 with the surface to be measured facing upward. Next, the feed screw 22 is driven by the drive motor 22C.
A is rotated to move the crankshaft holding means 20 so that the beam scanning surface 12 comes to one end position in the X direction of the crankshaft to be measured 18 placed thereon. In this state, the optical dimension measuring device 10 is driven to measure the crank shirt l-1 with the parallel scanning light beam 50.
Scan 8. By this scanning, the dimension in the Y direction of the gap 19 between the crankshaft 18 to be measured and the reference 11A16A of the measurement reference body 16 is measured, and this is displayed on the display 26 as described above. At this time, the position of the crankshaft holding means 20 in the X direction is detected by the movement amount detecting means 24 and displayed on the display 26 via the counting circuit 38. Therefore, the display 26 shows the crankshaft 18 to be measured.
XXY of the outline line in the cross section along plane 14 of the convex surface of
The directional position will be displayed. Here, the radius of the eight portions 18B at both ends of the bin portion 18A of the crankshaft 18 to be measured is detected by numerical processing such as the method of least squares based on a plurality of dimension measurements in the Y direction of the gap 19 in the eight portions 18B. Find it by In this way, the moving means 22 drives the crankshaft holding means 2o together with the measurement reference body 16 in the X direction, while moving the gap 19 in the Y direction! By measuring the distance, the outer diameter IX and Y coordinates and the radius of the 8th part 18B in the cross section of the crankshaft 18 to be measured along the plane 14 can be obtained. Therefore, if an X, Y plotter or the like is provided in connection with the display 26, the outline of the crankshaft 18 to be measured can be easily obtained. Here, by scanning the parallel scanning light beam 4o to the outline of the crankshaft 18 on the opposite side to the outline facing the straight edge 16A,
The outer diameter of the pin portion 18A can be measured. This outer diameter can be detected from the time of the falling portion of the output waveform obtained by the light receiving element 56 and amplified by the preamplifier 58. In the above embodiment, the optical dimension measuring device 10 forms a parallel scanning beam by reflecting the laser beam with a polygonal rotating mirror, but the present invention is not limited to this. If necessary, any light beam may be used as long as it can scan the gap between the reference line 16A of the measurement reference body 16 and the crankshaft 18 to be measured. Therefore, for example, those using a light emitting source other than a laser tube,
It is also possible to use a beam conversion means consisting of a plane mirror, or one that converts a light beam into a fan-shaped scanning beam using ultrasonic waves. Further, in the above embodiment, the measurement reference body 16 is a straight reference body, and the reference line 16A is a straight reference line. It may be made to match the target shape. In this case, the variation in the numerical value of one gap itself indicates the variation in the shape of the crankshaft 18 to be measured. However, in the case of a straight reference body, manufacturing is easy and
It has advantages in terms of versatility, and signal processing during measurement is also easy. Further, in the embodiment described above, the measurement reference body 16 has the crankshaft 18 to be measured i! ! It is driven in the X direction by the moving means 22 together with the crankshaft holding means 20 placed thereon. For example, the measurement reference body 16 is formed long in the
0 may be attached to the base 36 separately, and only the crankshaft holding means 20 that holds the crankshaft 18 to be measured Mffi may be driven in the X direction by the moving means 22. Further, the moving means 22 includes a feed screw 22A1.
The moving means 22 is composed of a nut 22B1 and a jamming motor 22C, but the structure is limited to the embodiment as long as the moving means 22 can move at least the crankshaft holding means 20 in the X direction if necessary. Not done. Further, the movement 11Jffi detection means 24 is composed of a linear encoder including an optical scale 24 and an index scale 24B, but the present invention is not limited thereto. For example, the movement date detection means may be such that the drive motor 22C in the movement means 22 is a pulse motor and the movement n is detected from the number of pulses of the drive motor 22C. In the above embodiment, the display 26 simultaneously digitally displays the X and Y coordinates on the outline of the crankshaft 1.8 to be measured.
It may be something like this.

【Effect of the invention】

Since the present invention is configured as described above, it has the excellent effect of being able to measure the surface shape of a crankshaft without contact, at high speed, and accurately.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the crankshaft non-contact shape measuring device according to the present invention, and FIG.
FIG. 3 is a plot diagram showing an optical dimension measuring instrument in the same embodiment, and FIG. 4 is a front view showing a crankshaft to be measured by the method of the present invention. 10... Optical dimension measuring device, 12... Beam scanning plane, 14... Plane, 16... Measurement! 3Q body, 16A... Reference line, 18... Crankshaft to be measured, one... Gap, 20... Crankshaft holding means, 22... Moving means, 24... Movement detection Means, 26...Display device.

Claims (5)

[Claims] (1) The reference line of the measurement reference body and the measurement cross section of the crankshaft to be measured are located in a plane perpendicular to the scanning surface of an optical dimension measuring device that scans the object to be measured in one direction with a light beam, and so that the reference line and the measured cross section of the measured crankshaft face each other with a gap in the scanning direction of the light beam,
arranging the measurement reference body and the crankshaft to be measured, and scanning at least one of the measurement reference body and the crankshaft to be measured along the plane with respect to the scanning plane of the light beam; A non-contact shape measuring method for a crankshaft, which measures the gap while moving relatively in a direction perpendicular to the surface. (2) An optical dimension measuring device that scans the object to be measured in one direction with a light beam, and a reference in a plane perpendicular to the beam scanning surface of the light beam and in a direction substantially perpendicular to the beam scanning surface. a measurement reference body arranged so that there is a line, and a crankshaft to be measured, which is held so that the cross section to be measured faces the reference line with a gap in the beam scanning direction within the plane. a holding means, and a moving means for relatively moving at least the crankshaft holding means of the crankshaft holding means and the measurement reference body along the plane in a direction perpendicular to the beam scanning plane; a movement amount detection means for detecting the amount of movement of the crankshaft holding means relative to the beam scanning surface by the movement means; and a position of the crankshaft to be measured based on the movement amount detected by the movement amount detection means. In relation to this, there is provided a non-contact shape measuring device for a crankshaft, comprising: a display device that displays the dimension of the gap measured by the optical dimension measuring device. (3) The non-contact shape measuring device for a crankshaft according to claim 2, wherein the reference line of the measurement reference body is a straight edge. (4) The non-contact shape measuring device for a crankshaft according to claim 2, wherein the reference line on the measurement reference body is a curve of an ideal shape of the crankshaft to be measured. (5) The measurement reference body is integrally provided with the crankshaft holder, as claimed in Claims 2 and 3.
A non-contact shape measuring device for a crankshaft according to item 1 or 4.