JPH0296603A - Gap measuring device - Google Patents

Abstract

PURPOSE:To make it possible to measure the width of a gap at materials to be tested (rails) from a relatively moving body (vehicle) positively and accurately by computing the width of the gap based on the signals from first and second gap detecting means. CONSTITUTION:First and second gap detecting means 1 and 2 are mounted on a vehicle 10 so as not to impede the rotation of a wheel 10a with a distance L being provided in the extending direction of rails 9. The means 1 comprises a lighting optical system 1a which projects light on the rail 9 and a light receiving optical system 1b which receives the reflected light from the rail 9. The means 2 has the similar constitution. The width of the gap is computed with an operating means 3 based on the signals from the means 1 and 2. Even if the vehicle 10 is vibrated up and down during the measurement and the height of the lighting optical system from the surface of the rail 9 under test is changed, the projected light is not deviated in the width direction of the gap. Therefore, the measuring accuracy becomes high.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a gap measuring device for measuring the width of a gap between two relatively moving objects, from one object to the other object. The present invention relates to a gap measuring device suitable for measuring the width of a gap at a joint between rails laid on the ground from a running railway vehicle.

[Conventional technology] In order to accommodate the expansion and contraction caused by temperature, railway rails
A gap of a certain width is provided at the joint. For the safe running of vehicles, the management of these gaps is extremely important, and it is necessary to monitor all of them, but in the past, humans measured the width by applying a feeler gauge to each gap. .

[The invention tries to solve 0! N] However, in the conventional measurement method as described above, each gap
There have been problems in that it takes time and effort to make one measurement, and it also takes time to move B from one measurement point to the next, requiring a great deal of effort.

This invention has been made in view of the above, and provides a gap measuring device that can measure the gap between a running vehicle and a rail, that is, the width of the gap between a moving object and a test object with certainty. It is an object of the present invention to provide a gap measuring device that can measure gaps with high accuracy.

[Means for Solving the Problems] In the present invention, in a gap measuring device that measures the width of a gap in a test object (rail) from a relatively moving object (vehicle), an irradiation optical system that irradiates the test object with light is used. First and second light receiving optical systems that receive reflected light from the test object of the system and the irradiation light are arranged such that the incident plane including the optical axis of both optical systems is perpendicular to the direction of relative movement. The above method is achieved by arranging the gap detection means at a predetermined interval in the direction of relative movement and by providing a calculation means for calculating the width of the gap based on the signals from the first and second gap detection means. has achieved the following goals.

[Function] In the present invention, the gap between the test objects is detected by the first and second gap detection means each consisting of the irradiation optical system and the light receiving optical system, and the width of the gap is calculated based on the detection signal. There is.

When the first gap detection means passes through the gap of the test object,
The intensity of the light emitted from the irradiation optical system, reflected by the test object, and incident on the light receiving optical system rapidly decreases as shown in (^) in FIG. 3 while passing through the gap.

The time T during which the detection signal is decreasing corresponds to the width of the gap, and if the moving speed V of the first gap detection means is known, the width W of the gap can be calculated using equation (1).

w=vlT...(1) However, if the value of the moving speed V is not accurately known,
It is not possible to determine the width W of the gap with this alone.

Therefore, in the present invention, second gap detection means having the same configuration as the first gap detection means are arranged at a predetermined interval (L) I11i in the direction of relative movement, and the detection signals of the two detection means are The speed V of the detection means is calculated from the time difference. However, it is assumed that the moving speed V of the object carrying the gap measuring device does not change until the second gap detecting device passes through the gap following the first gap detecting device.

(B) in FIG. 3 shows the change over time of the detection signal of the second gap detection means. (8) and (B) in Fig. 3 have the same waveform, and from the time difference t between the two and the distance 11tL between the first and second gap detection means, the relative movement speed V is calculated by equation (2). It can be calculated as follows.

v = L / t ... (2) (2) formula (1
), w=L-T/l... (3) That is, in the present invention, it is a known value, and from the measured values T and t by the first and second gap detection means, it can be written into equation (3). Then, the width W of the gap is calculated.

[Example] FIGS. 1 and 2 are a schematic front view and a side view, respectively, showing an example of the present invention.

1.2 are first and second gap detection means, which are mounted on the vehicle 10 at a distance in the extending direction of the rail 9 so as not to interfere with rotation of the wheel 10a. 3 is a calculation means that calculates the width of the gap based on the detection signals of the first and second gap detection means 1 and 2.

Since the two gap detection means 1.2 have the same construction, the first gap detection means 1.2 will be explained with reference to FIG. In the figure, the gap detection means 1 consists of an irradiation optical system 1a that irradiates light onto the rail 9 and a light receiving optical system 1b that receives reflected light from the rail 9, and a light emitting part of the light source 4 of the irradiation optical system 1a. The surface of the rail 9, the surface of the rail 9, and the light-receiving part of the detector 8 of the light-receiving optical system tb are located in a plane perpendicular to the plane (incidence plane) containing the optical axes of both optical systems, that is, in the plane of the paper of FIG. They have a conjugate relationship in the vertical plane.

Further, in the present invention, the irradiation optical system 1a and the light receiving optical system 1b are arranged such that the entrance planes including the optical axes of both optical systems are perpendicular to the direction of relative movement (width direction of the gap).

By arranging the optical system in this way, firstly, even if the vehicle 10 vibrates vertically during measurement and the height of the irradiation optical system with respect to the rail surface to be tested changes, the slit-shaped irradiation light 12 (described later) ) is only shifted in the vertical direction of the paper (direction perpendicular to the extension direction of the rail 9) in Figure 4, but not in the width direction of the gap, so the measurement accuracy of the gap detection signal in the time axis direction is extremely high. There are advantages. Secondly, there are minute scratches on the surface of the rail 9 that are created along the elongation direction during rolling, but the scattered light due to these scratches has stronger directivity in the direction perpendicular to the rail elongation direction. Regarding the movement of irradiated light, there is an advantage that there is little influence when condensing scattered light with a lens.

In the irradiation optical system 1a, the light emitted from the light source 4, such as a semiconductor laser, becomes a parallel beam at the lens 5a, and then passes through the cylindrical lens 6a to have a rectangular cross-sectional shape, and the rail 9 is formed as shown in FIG. A slit-shaped beam of light is emitted perpendicular to the direction in which the rail extends.

In this embodiment, the reason why the irradiation light beam is shaped like a slit is as follows. If the irradiation light beam is in the form of a spot, if the irradiation part on the rail has a scratch that is as large as the light spot or larger, most of the irradiation light will be scattered by the scratch and the detection signal will drop. The decrease in the output signal in such a case is due to the decrease in the detection signal when the reflected light from the rail surface is interrupted at the gap between the rail joints.
The difference is not so large that it becomes difficult to distinguish between scratches and gaps.

On the other hand, if the irradiation light is made into a slit, even if the rail has a scratch of the same size as above, only a portion of the light will be scattered, and it will be difficult to detect compared to the gap where the entire reflected light from the rail surface is interrupted. There is little signal degradation and it is easy to distinguish between flaws and gaps, that is, even if there is a relatively large flaw on a portion of the rail 9, it is easy to distinguish between the rail surface and the gap.

Next, the reflected light and scattered light from the rail 9 pass through the cylindrical lens 6b of the light receiving optical system 1b, and then only the light corresponding to the wavelength of the light source 4 passes through the wavelength filter. The light transmitted through the wavelength filter 7 is focused by a lens 5b and enters a detector 8 such as a photodiode. By disposing the wavelength filter 7 in the light-receiving optical system 1b (the position is not limited) in this way, the influence of light from the outside world can be removed. If the wavelength filter 7 alone cannot completely remove the influence of light from the outside world, the light emitted from the light source 4 may be intensity-modulated at a certain frequency, and this frequency component of the signal detected by the detector 8 may be All you have to do is take out only those things.

When the above-mentioned first and second gap detection means pass through the gap of the rail 9, (^) and (83) in FIG.
A detection signal like this is obtained. The two detection means have the same configuration, and the two detection signals are the same except for the time difference. Therefore, the time difference t between the two detection signals and the time T during which the signal decreases (of the gap) width) to
The width of the gap can be calculated by the calculating means 3 based on the above-mentioned equation (3).

In the case of FIG. 3, the time difference t between the detection signals of the first and second gap detection means and the gap passing time T are measured based on the fall and rise times of the detection signals. If the level of the detection signal changes due to non-uniformity in the reflectance of the rail, it becomes difficult to stably define the falling and rising times.

In order to solve this problem, as shown in Fig. 5, the detection signal in Fig. 3 is differentiated, this peak is detected,
By measuring the time between these, it is possible to determine , and T, regardless of the level change of the detected f3.

In Figures 3 and 5 described above, it is assumed that the two detection signals are the same except for the time difference, but if the two detection signals are slightly different due to the influence of noise etc., the two detection signals for T may be different. The width of the gap can be determined accurately by calculating the average of the measured values of each signal and, for t, by calculating the average of the difference in fall time and the difference in rise time of the two detection signals.

It would be more preferable if the rail temperature could be measured at the same time when measuring the gap, but as shown in Figure 1, the radiation thermometer
By mounting the sensor 1 on a running vehicle, it is possible to measure the temperature of the rail in a non-contact manner in parallel with the gap measurement. At this time, since the upper surface of the rail 9 is almost a mirror surface, the emissivity is almost zero and cannot be measured. Therefore, as shown in Fig. 1, the radiation from the side surface of the rail 9 is measured from an oblique direction. It is necessary to take measurements.

The above has been about rail gap measurement, but
The gap measuring device according to the present invention is not only used for such purposes, but can also be used widely when measuring the width of a gap between two objects that are moving relative to each other from one of the objects to the other object. It's a colander. As in the above example, it is not only possible to measure the gap between a stationary test object (rail) from a relatively moving object (vehicle), but also to It can also be applied to automatic measurement of the width of a specific gap between parts flowing one after another. It goes without saying that the gap to be measured in the present invention does not necessarily have to be a space, and may be a gap created by changing the material or color of the test object by a predetermined width area.

[Effects of the Invention] In the present invention, first and second gap detection means each consisting of an irradiation optical system and a light receiving optical system are arranged in a line at a predetermined interval in the direction of relative movement, and detection signals from the respective detection means are detected. Since the width of the gap is calculated based on The key is to measure quickly and accurately.

Further, since the irradiation optical system and the light receiving optical system of the gap detection means are arranged so that the entrance plane including the optical axes of both optical systems is perpendicular to the direction of relative movement, the gap measuring device according to the present invention Even when the object on which the test object is mounted vibrates up and down, or there are many linear scratches on the surface of the test object along the direction of relative movement, the effects of vibration and single scratches are small, and highly accurate measurements are possible. be.

If such a gap measuring device is mounted on a running vehicle and used to measure rail joint gaps, it is possible to measure a large number of gaps with high accuracy in a short period of time, making rail management much more efficient than before. be able to.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of an embodiment of the present invention, FIG. 2 is a schematic side view of an embodiment of the present invention, FIG. 3 is an explanatory diagram of detection signals of each gap detection means, and FIG. 4 is an example of an embodiment of the present invention. FIG. 5 is an explanatory diagram showing the shape of the irradiation light beam in the example, and FIG. 5 is an explanatory diagram showing the case where the detection signal shown in FIG. 3 is differentiated. [Description of symbols of main parts] 1...First gap detection means 1a...Irradiation optical system ib...Light receiving optical system 2...Second gap detection means 3...Calculation means 4. ...Light source 7...Wavelength filter 8...Detector 9...Rail 10...Vehicle 11...Radiation thermometer 1st representative Patent attorney Masatoshi Sato

Claims (1)

[Scope of claims] A gap measuring device that measures the width of a gap in a test object from a relatively moving object, comprising: an irradiation optical system that irradiates light onto the test object; and a reflection of the irradiation light from the test object. first and second gap detection means, each of which has a light receiving optical system for receiving light, arranged such that an incident plane including an optical axis of both optical systems is perpendicular to the direction of the relative movement; Calculation of arranging first and second gap detection means at a predetermined interval in the direction of the relative movement, and calculating the width of the gap based on signals from the first and second gap detection means. A gap measuring device characterized by comprising means.