JPS6195208A - Range finder for fabricating machine - Google Patents

Abstract

PURPOSE:To reduce dimensions of an apparatus and make it applicable to a 3-dimensional article of intricate shape also, by irradiating plural luminous spots on an object work using a plurality of optical fibers. CONSTITUTION:A light radiating means is constructed by source 4, light-divider 10, optical fiber 11 and light-radiating lens 5 and a light-receiving means by light-receiving lens 6 and light-receiving element 7. After the light flux of the source 4 is irradiated into the divider 10 for uniform distribution into a plurality of optical fibers 11, the flux is converged in a luminous spot of proper size by the lens 5 and the surface of a work is irradiated. Each luminous spot develops an image on the light-receiving surface of the element 7 through the lens 6. The light-receiving element 7, as it issues center of gravity of a plurality of the luminous spot, each luminous spot is irradiated symmetrically around the fabricating area, and when the area is of a uniform intensity, it represent an output corresponding to the position of the fabricating area. A processing circuit 8 introduces electric signals iA, iB, performs the specified calculation and issues a distance output (l) out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance meter for a processing machine, and particularly to a device for non-contactly measuring the distance to a target workpiece in order to control a processing head.

[Conventional technology]

Conventionally, there has been a device of this type as shown in FIG. In the figure, (1) is a laser beam for processing,
+21 Fi laser beam (1) t-focusing processing lens, (3) target workpiece: +41
(51 is a light projection lens that collects and collects the light beam emitted from the light source; (6) is a light receiving lens that captures a synchrotron radiation image on the surface of the workpiece; A light-receiving element (8
A processing circuit (9) is the entire processing head which processes the electrical value 8- outputted from the single light receiving element (7) and sends out the distance output t.

The laser beam for processing is focused by a processing lens (2) and irradiated onto the workpiece surface to perform processing such as welding and cutting. 4. To increase processing efficiency.

It is necessary to match the beam waist position of laser beam +11 to the workpiece position. Distance t' between the handle, processing lens (2) and workpiece! It is controlled to a constant value.

In the conventional device, the above-mentioned distance t' (distance) is measured using an optical distance meter, which will be explained below, and the position of the processing head (9) is controlled.Hereinafter, the operation of the distance meter in the conventional device will be explained. explain.

Luminous flux emitted by light source (4), projection lens (6)
This creates a light spot of an appropriate size and focuses on the target workpiece (3
) is irradiated onto the surface. The light receiving lens (6) images the light spot v and forms an image of the light spot on the light receiving surface of the light receiving element (7). The light receiving element (7) is also called an optical position detector, and generates an electric signal according to the imaging position of the optical spot image. That is, the imaging position P of the original spot image is obtained by the values of the currents IA and iB generated in the two electrodes of the light receiving element (7). The output of the light receiving element (7+) generates an output proportional to the position and intensity of the light spot image, so the illumination
In equation 1, it corresponds to the intensity change of the light spot image (IA-1
-1B) is introduced to obtain an output proportional only to the position of the light spot.

On the other hand, it is obtained as a distance @A on the work surface 1 from the light spot of the projecting and receiving lenses tel and 1B+. Among these, ψ is a fixed value determined only by the configuration of the device. In addition, θ is determined by the position P of the light spot image mentioned above, the focal length of the light receiving lens, and the installation position, but other than P (Fi tit) is a fixed value. Only P that corresponds to is calculated as an r variable.The distance 111t between the processing lens (2) and the workpiece surface is also simply a constant constant added to A, and t- is expressed as -P... (3) The processing circuit (81) executes the above calculations and sends out the distance output t.The processing head (91V'i,
By using the above value of t, the beam waist of the laser beam (11) is always controlled to be at the position of the workpiece (3), and the optimum processing state is maintained.

[Problem that the invention seeks to solve]

Since the conventional distance meter for processing machines as described above irradiates the radiation beam obliquely from one direction, for example, as shown in Fig. 3, the irradiated position of the light spot changes depending on the displacement of the target workpiece (3). For objects with three-dimensional curved surfaces, it is difficult to accurately measure the distance to the machined part, and it is difficult to
There were problems such as the light-receiving part becoming harsh.

This invention was made to solve such problems, and is a distance meter for processing machines that can accurately measure the distance to the processing part even for objects with three-dimensional curved surfaces, and can also miniaturize the fc device. This is what we are trying to provide.

[Problems (+-Means to solve)]

A distance measuring device for a processing machine according to the present invention uses a plurality of optical fibers to irradiate a plurality of light spots onto a target workpiece, and irradiates the target workpiece with a plurality of light spots '(r), and the image of the light spot is reflected on the target workpiece. It measures the distance to.

[Effect]

In the rangefinder according to the present invention, a plurality of light spot images are generated for an object having a three-dimensional curved surface, and the light receiving means outputs the center of gravity of the plurality of light spot images and determines the position of the processing section. Outputs the corresponding electrical signal and calculates the distance *i to the target workpiece.

〔Example〕

Hereinafter, an example of a plane of the present invention will be explained with reference to the drawings. 1st
In the figure, the laser beam (11) to the processing head (91
(lO) is an optical splitter that evenly splits the emitted light from the light source (4) into multiple optical fibers, and (lO) is an optical fiber that is branched and transmits dimensions. .

Note that the light source (4), the optical splitter (101), the optical fiber η, and the light projecting lens tfi+ constitute a light projecting means, and the light receiving lens (6) and the light receiving element (7) constitute a light receiving means.

The operation of the distance hand according to this invention is as follows.

The luminous flux emitted from the light +*L41 is sent to the optical splitter tlO+
fc human radiation, 1i several optical fibers (b) evenly r
(The light beam transmitted by the optical fiber circuit is emitted from the other side end face, and is focused by the projection lens 15+ into a light spot of a suitable size, and is irradiated onto the work surface.

These aα light spots are irradiated onto symmetrical positions across the processing area, and each light spot is imaged by the light receiving lens (6) onto the light receiving surface of the light receiving element (71. ) and outputs the center of gravity position of multiple light spots, so if each light spot is irradiated at a symmetrical position with the processed part as the center and has uniform intensity, the output will correspond to the position of the processed part. In other words, as mentioned in the explanation of the conventional device, the value of P obtained by equation 11 corresponds to the position of the machining part. Since there is no change, it can be obtained by the same development as the conventional device.

-P to t - (3> times) is calculated. The distance t between the processing lens (2) and the workpiece (3) also exactly corresponds to the position of the processing section.

Processing circuit vlIC81 light receiving element (electrical signal from 71
A.

Input 1B, perform the specified calculation, and get the distance output t? Send. The machining head (9) is controlled by the value of t and maintains the optimum machining state.

In addition, in the above practical example, the radiation source from the light source (41) was branched into the optical fiber 〇 of the reconnaissance book using the metal light splitter side.
Light # (41) may be provided for every light 7 eyeper (6).

Also, I have shown an example using the photodetector 17 + optical position detector, but is this a COD or other glue sensor array? Similar functionality can be obtained by using Furthermore, a window or optical filter may be inserted into the light emitting/receiving system to remove machining debris from the machining surface and source noise during machining, and a light source (4
), and selectively process only this modulated frequency signal on the light receiving side.
(In addition, although the distance meter for a laser processing machine was described in the above practical example, it can also be applied to a rangefinder for other processing machines.

〔Effect of the invention〕

As described above, according to the present invention, a plurality of original spots are irradiated around the machining part using an optical fin (-), so that the workpiece is not affected by the displacement or inclination of the target workpiece, and is always placed in the machining part. The distance can be measured.

Furthermore, since the device is miniaturized, it is possible to obtain a distance meter for processing machines that can be used even for three-dimensional objects having complicated shapes.

[Brief explanation of drawings]

Figure d1: A cross-sectional configuration diagram showing a distance meter for a processing machine according to a practical example of the present invention; Figure 2 is a cross-sectional configuration diagram showing a conventional rangefinder for a processing machine; Figure 3 is a diagram showing a conventional rangefinder for a processing machine. FIG. (3)...Target work, (4)...Light source, 151
... Light emitting lens, (6) ... Light receiving lens, (1'r
... Light receiving element, (8) ... Processing circuit, (lO) ...
・Optical splitter, α-chin...Optical fin (-In Figure 1, the same reference numerals indicate the same straddle-corresponding parts.

Claims (3)

[Claims] (1) Light projecting means for irradiating a plurality of light spots onto a target work using a plurality of optical fibers, capturing an image of the light spot on the target work, and an electrical signal corresponding to the imaging position of the light spot image. A distance meter for a processing machine, comprising a light receiving means that generates a light receiving means, and a processing circuit that calculates an electric signal sent by the light receiving means and outputs a distance to the target work. (2) The distance meter for a processing machine according to claim 1, wherein the light projecting means has a plurality of light sources that emit a luminous flux and a plurality of optical fibers that transmit the luminous flux. (3) The light projection means is composed of a light source that emits a luminous flux, an optical splitter that equally splits the luminous flux, and a plurality of optical fibers that transmit the plurality of luminous fluxes obtained by the optical splitter. A distance meter for a processing machine according to claim 1, characterized in that: