JPH05285679A - Starting hole detector for laser beam machine - Google Patents

Abstract

PURPOSE:To improve working efficiency and product yield by providing a sensor which senses the light emission arising when laser beam penetrates a work and falls onto a light emitting object and detecting the penetration of a starting hole. CONSTITUTION:The light emitting object 7 is placed in the position where the laser beam 4 emitted from a beam nozzle 1 falls onto the object when the beam 4 penetrates the work 4. The penetration is detected by placing the sensor 6 in the position where visible rays 5 can be captured and sensed when the beam 4 falls onto the object 7 by penetrating the work 2 by a processing operation and the object 7 emits the rays 5. A controller applies a command for the next operation to a processing machine by the signal from the sensor 6 and the processing of the work 2 is executed without time loss.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting hole detecting device in a laser beam machine, and its purpose is to improve the efficiency of a work for cutting a work by a laser beam.

[0002]

2. Description of the Related Art When a work is cut or drilled by an NC laser beam machine, a hole called a piercing hole or a starting hole is first opened and then cutting is started. In the case of the conventional laser processing machine, the diagram is shown in Fig. 3, but the time when the hole is opened after the shutter is opened and the laser beam is emitted is preset for each material, and the time multiplied by the safety factor is set by the timer. It was set so that the piercing hole or the starting hole was completely penetrated and the next cutting step was performed.

[0003]

In such a method, since the processing material is a uniform material such as an iron plate or a stainless steel plate, there is no problem in the time lag until the perforation.
However, as mentioned above, it is necessary to set an extra time for safety in order to make a hole securely.
If the machining time becomes long and the number of machining is large, it will be accumulated.
It was a significant time loss and utility loss.

Further, a material whose processing material is not uniform, for example,
In the case of a mixture of different materials such as a ceramic sintered body,
The variation in the starting time was so great that we had to take an extremely useless safety factor.

[0005]

SUMMARY OF THE INVENTION In view of the above situation, the present invention, in order to reliably detect the penetration of a starting hole in laser processing, is provided on the opposite side of a workpiece irradiated with laser light. It is characterized in that a sensor is provided for detecting that the laser light due to the penetration of the hole hits an object and emits light.

Since the laser beam has a straight traveling property and has a strong destructive force when hit by the laser beam, direct detection is impossible. However, when the laser light blocked by the work reaches the back side of the work due to the penetration of the work, the laser light hits another object and emits light, and the visible light is dispersed to utilize this visible light. By providing a sensor that indirectly captures, it becomes possible to give the next command to the processing machine. Therefore, any type of sensor that can detect this light emission can be used. For example, a light receiving diode or a cadmium cell is useful.

[0007]

When the NC laser beam machine is used to punch or cut a work, when the laser light penetrates the work, the laser light strikes another object and emits light to disperse visible light. The sensor indirectly captures the visible light, not the laser light, and detects that the starting hole has penetrated the work. As a result, immediately after the starting hole penetrates, the next command such as movement of the work or movement of the laser is given, and the work can be processed without time loss.

For example, in a ceramic sintered body in which hard particles are dispersed and mixed, a hole is formed in about 1 second or less only in the sea portion, and if it hits many islands, a penetration time of about 10 seconds is required. At that time, in the past, the timer was set to 12 seconds in view of the safety factor. Therefore, according to the present invention, the time loss when making a large number of holes in such a ceramic sintered body is extremely reduced. Also, only those with holes are always processed.

[0009]

FIG. 1 is a diagram of the present invention.
FIG. 2 is a diagram showing a starting hole detecting device in the laser processing machine of the present invention. This device uses a laser beam 4 emitted from a beam nozzle 1 of a laser beam machine.
However, the light emitting object 7 is arranged in a portion which reaches the work 2 after penetrating the starting hole 3. The light-emitting object 7 produces a visible ray 5 when exposed to the laser light. The sensor 6 is provided at a position where the visible light 5 can be captured.

In this embodiment, YAG laser light of 0.4 KW output is used as the laser light 4, the work 2 is a 16 mm thick ceramic, and the light emitting object 7 is also a ceramic. A light receiving diode is arranged in the sensor 6. The circuit diagram of the sensor is shown in FIG.

As a result of the operation of the apparatus as described above, when the laser light penetrates through the work 2, the laser light is emitted by the laser light.
Then, the visible light is captured by the sensor as an electric signal as shown in FIG. This signal is sent to the CPU of the laser processing machine, and the cutting operation can be immediately started. This allows the timer set 12 to be used when making holes in the ceramic sintered body by the conventional method.
From the second, the laser is irradiated only for the time actually required for drilling from about 10 seconds to the next step, and the work is not wasted.

【The invention's effect】

According to the present invention, the working material is not limited to a uniform material such as an iron plate or a stainless steel plate, but even a member having a sea island such as a ceramic sintered body is immediately made to have a hole and then immediately proceeds to the next work. Therefore, time loss and utility loss can be eliminated, which contributes to improvement of work efficiency and reduction of work cost. Furthermore, since the method is such that only those with holes are processed, defective products are eliminated, and product retention is improved.

[Brief description of drawings]

FIG. 1 is a diagram of the present invention.

FIG. 2 is a side view showing a starting hole detection device of the present invention.

FIG. 3 is a diagram of a conventional case.

FIG. 4 is a circuit diagram of a sensor.

FIG. 5 is a sensing curve of a sensor.

[Explanation of symbols]

 1 Beam Nozzle 2 Work 3 Starting Hole 4 Laser Light 5 Visible Light 6 Sensor 7 Light Emitting Object

Claims (1)

[Claims] 1. On the opposite side of the workpiece irradiated with laser light,
A starting hole detecting device in a laser processing machine, comprising a sensor for detecting that a laser beam due to a penetration of the starting hole hits an object and emits light.