JPH04110708A - Device for measuring surface - Google Patents

Abstract

PURPOSE:To measure height of a projection on the surface without contact with the projection by changing the direction of the laser beam to scan the surface of a material to be measured, and obtaining the surface form of the material to be measured on the basis of the strength of the laser beam reflected by the material to be measured and the scanning information. CONSTITUTION:Direction of the laser beam radiated from a laser generating unit 10 is changed by a scanner 20, which is turned for oscillation at a constant cycle, to be projected to a material 60 to be measured. The laser beam reflected by the surface of the material 60 to be measured is condensed by a condenser lens 30, and is projected to the light receiving surface of a photodiode 40. The diode 40 outputs the electrical signal in response to the strength of the projected laser beam. An information processing means 50 processes the electrical signal from the diode 40 with the angle signal from the scanner 20 and, height of burr of the material to be measured can be obtained with a predetermined formula.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a surface measuring device, and particularly to a surface measuring device suitable for detecting pars in castings.

[Conventional technology]

In casting, Paris has a negative effect on dimensional accuracy, so
Deburring is an important process.

Conventionally, paring has been mainly done manually.

Even in automation, Paris detection is not performed, and the operating path of the cutting tool or grinding tool is taught to the shape of the casting surface, and the contact pressure between the cutting tool or grinding tool and the casting surface is kept constant. This is monitored by a pressure sensor, and the protrusions are cut or ground by operating a cutting tool or grinding tool that follows the shape of the casting to remove debris.

[Problem to be solved by the invention]

However, in the conventional example described above, it is not possible to detect the deviation of the tool position from the taught position in real time, so there is a problem that the casting may be ground if the tool position deviation occurs.

Furthermore, if the paris is strong enough to activate the pressure sensor, there is also the problem that the removal of the paris is incomplete.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to improve the disadvantages of the conventional method and to provide a surface measuring device that can continuously and accurately measure the height of protrusions on a surface in a non-contact manner.

[Means to solve the problem]

Therefore, in the present invention, a laser beam emitting means for emitting a laser beam, a scanning means for changing the direction of the laser beam from the laser beam emitting means and scanning the surface of the measured object, and a scanning means for scanning the surface of the measured object by changing the direction of the laser beam from the laser beam emitting means, A condensing means for condensing the laser beam reflected on the surface, a light amount measuring means for measuring the intensity of the focused laser beam, and a light receiving means using information from the light amount measuring means and information from the scanning means. The system is configured to include an information processing means for determining the surface shape of the object to be measured.

This aims to achieve the above-mentioned purpose.

[Function] (2) The direction of the laser beam emitted from the laser beam emitting means is changed by the scanning means which rotates and oscillates at a constant period, and the laser beam is projected so as to scan the object to be measured.

(2) The laser beam projected onto the object to be measured is reflected by the surface of the object to be measured.

(1) The reflected laser beam is focused by a focusing means.

(2) The focused laser beam is projected onto the light receiving surface of the light amount measuring means.

(2) The light amount measuring means outputs an electric signal proportional to the intensity of the projected laser beam.

(2) The electric signal from the light amount measuring means is converted into a signal by the information processing means, and when the reflected laser beam is blocked by a protrusion, it becomes a low level signal, and when there is nothing blocking it, it becomes a high level signal.

③ When a corobel signal is detected, the angle of the scanning means when the signal changes from a high level signal to a low level signal, and conversely the angle of the scanning means when a signal changes from a low level signal to a high level signal. Detected.

Then, the height of the protrusion is determined from these angles using a predetermined calculation formula.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

The embodiment shown in FIG. 1 includes a laser beam emitting means 10 for emitting a laser beam, and a scanning means 20 for scanning the surface of an object to be measured 60 by changing the direction of the laser beam from the laser beam emitting means 1o. , a condensing means 30 for condensing the laser beam reflected on the surface of the object to be measured 600, a light amount measuring means 40 for measuring the intensity of the focused laser beam, and information from the light amount measuring means 40. and information processing means 50 for determining the surface shape of the object to be measured 600 based on the information from the scanning means 20.
It is composed of.

Here, as shown in FIG. 2, the laser beam emitting means 10
as a laser oscillator, as the scanning means 20, a scanner, as the condensing means 30, a condensing lens, and as the light amount measuring means 40.
Although a photodiode is used as the information processing means 50, the information processing means 50 is not limited to these, but as shown in FIG. 51, an encoder 54 for encoding the angle signal from the scanner 20, a CPU 52 for performing predetermined signal processing based on information from the comparator 51 and the encoder 54, and a processing program for operating the CPU 52. It is composed of a ROM 53, which is stored in the computer, and a RAM 54, which is used to temporarily store data.

Next, the operation of this embodiment will be explained.

■The direction of the laser beam emitted from the laser oscillator 10 is changed by the scanner 20, which rotates and oscillates at a constant period.
The light is projected so as to scan the object to be measured 60.

(2) The laser beam projected onto the object to be measured 60 is reflected by the surface of the object to be measured 60.

(2) The reflected laser beam is condensed by a condensing lens 30.

(2) The focused laser beam is projected onto the light receiving surface of the photodiode 40.

(2) The photodiode 40 outputs an electric signal proportional to the intensity of the projected laser beam.

■The electrical signal from the photodiode 40 is converted by the comparator 51, and as shown in Figure 4, if the reflected laser light is blocked by Paris, it becomes a low level signal, and if there is nothing blocking it, it becomes a high level signal. .

■When a low level signal is detected by the CPU 52, as shown in FIG. 5, the angle α1 of the scanner 20 changes from a high level signal to a low level signal, and vice versa. Scanner 20 when
angle α2 is detected. Here, it is assumed that a line connecting the rotation center 0 of the scanner 20 and the center E of the condensing lens 30 is parallel to the surface of the object to be measured 60. In addition, the leg of the perpendicular line drawn from point O to the surface of the object to be measured 60 is D, the line segment OD = B, the height of the firmness is H, and the length of the shadow of the firmness on the surface of the object to be measured 60 by the laser beam. Assuming that is X, the height H of the firmness is determined by the following formula.

H; Otsu・X / (X and -jan (90-θ)) Here, jan (90-α1)-jan (90-α2)
θ = (α1 + α2)/2.

〔Effect of the invention〕

As described above, according to the present invention, a laser beam emitting means for emitting a laser beam, a scanning means for changing the direction of the laser beam from the laser beam emitting means and scanning the surface of the object to be measured, and a scanning means for scanning the surface of the object to be measured by changing the direction of the laser beam from the laser beam emitting means. A condensing means for condensing the laser beam reflected on the surface of the object to be measured, a light amount measuring means for measuring the intensity of the focused laser beam, and information from the light amount measuring means and the scanning means. Since it is configured to include an information processing means for determining the surface shape of the object to be measured from the information, it is possible to continuously and accurately measure the height of protrusions on the surface without contact. Therefore, it is possible to provide an unprecedented and excellent surface measuring device that can completely automate deburring of castings and can perform deburring accurately and with high productivity.

50... Information processing means, 60... Measured object.

Claims (1)

[Claims] (1) a laser beam emitting means for emitting a laser beam; a scanning means for scanning the surface of the object to be measured by changing the direction of the laser beam from the laser beam emitting means; a condensing means for condensing the reflected laser beam;
It consists of a light amount measuring means for measuring the intensity of the focused laser beam, and an information processing means for determining the surface shape of the object to be measured using information from the light amount measuring means and information from the scanning means. Characteristic surface measuring device.