JPS6212880B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam irradiation device equipped with an electron accelerator and an electron cutoff device, which aims at uniform irradiation.

The method of irradiating rubber, plastic, etc. with electron beams to improve the physical and chemical properties of these materials has been widely industrialized in the fields of electric wires, tubes, films, etc. In these irradiation processes, efficient and uniform electron beam irradiation is an important deciding factor for industrialization conditions. Especially in terms of efficiency, recently electron accelerators with an output of 100KW
Although the accelerator has been scaled up to date, the rated output of the accelerator itself cannot be fully utilized due to mechanical constraints on the feed speed of the irradiated object.

In order to improve this problem, we adopted the so-called multi-zone irradiation method, in which the irradiation zone is divided and the object to be irradiated is transferred to each zone independently. A method has been proposed for providing an electronic cut-off device. In this method, the most important issue is how to use the electron blocking device and the object to uniformly irradiate the electron beam along the length of the object when blocking electrons using the electron blocking device. The purpose is to transport the irradiated object.

The present invention relates to an apparatus for obtaining uniform irradiation in an electron irradiation process using the above-mentioned electron cutoff device, and details of the present invention will be explained below using a practical example in a wire irradiation process.

Figures 1a and b show 2 during the general wire irradiation process.
This shows an outline of the process of simultaneously irradiating a seed irradiated object (an electric wire) with one accelerator.An electron beam 3 accelerated by an electron accelerator 1 is emitted into the atmosphere through an electron emission tube 2, and a roller 6, 6' and between rollers 7 and 7', each of the electric wires 4 and 5 is irradiated near the intersection of the cross lines while reciprocating many times in the direction across the scanning plane of the electron beam 3 in a so-called cross-cross state. . In this method, the length of the wire that is generally supplied is limited, so
Operation (feeding) of 4 and 5 wires for each connection work
It is necessary to stop the electron beam 3 at the same time as the stop, which poses a problem of reduced efficiency.

A method to solve this problem is to install the electronic cutoff devices 8 and 9 shown in FIG.
In this method, when a connection operation occurs, only the electronic cutoff device 8 is operated, and the electric wires 5 of one course are normally irradiated while avoiding over-irradiation of the electric wires 4.

The problem with this method is that the density distribution of the electron beam is not uniform in the direction of movement of the wire, as shown in Figure 3, but rather has a shape close to a Gaussian distribution. The question is whether to make the irradiation amount uniform in the length direction.

The present invention measures the electron current of each part when the electronic cut-off device is operated, and controls the speed of the electronic cut-off device and the feeding speed of the wire so that the amount of irradiation to the wire becomes uniform while performing calculation processing. This will be explained using FIG. 4. That is, it shows a state in which only the electric wire 4 has to be connected, and only the electron cutoff device 8 is moved at a speed V to cut off the electron beam 3, where i ₀ is the accelerator 1
The total amount of output electron beam 3 is measured with an ammeter of the circuit system (details are omitted here, but a _DC current measurement circuit of an accelerating DC power source may be used). Of the scattered electron flow,
The scattered electron beam flowing into the emission tube 2 is measured by an ammeter. In order to accurately measure _i1 , the emission tube 2 and the accelerator 1 are insulated with an electrical insulating material 11. Furthermore, regarding i ₂ , the electron beam flowing into the electronic cutoff device 8 was measured with an ammeter, and the code 1
2, 13, and 14 are respective signal lines.

In the above configuration, half of the total output electron beam i ₀ ,
That is, 1/2i ₀ normally irradiates the electric wire 5, and if the electron flow 3' that irradiates the electric wire 4 is i _x , then the electron flow lost into the air is negligibly small, so i _x = 1/2i It can be expressed as ₀ −i ₁ −i ₂ (1).

The arithmetic and control unit 15 has current signal lines 12, 13,
14, measure each current value of i ₀ , i ₁ , i ₂ and get (1)
The _i Since the present invention has the above-mentioned structure, which has the function of sending out the electric wire, the uniformity of irradiation of the electric wire is maintained even when the electronic cutoff device 8 is operated at a constant speed.

As shown in FIG. 3, the density distribution of the electron beam changes rapidly on the sides. In the present invention, this electron density changes rapidly. For example, this is a device that further improves irradiation uniformity even during startup and near shutdown, and is shown in FIG.

In FIG _{. 5} , a signal 17 of _i /dt serves to issue a signal 19 that controls the speed of the electronic cut-off device 8 so that it remains approximately constant.

For example, a microcomputer may be used as the arithmetic processing units 15 and 18 described above.

As a result of applying the electronic cutoff device and arithmetic processing device configured as described above to a two-course process for irradiation of 1MeV 50mA electric wires, productivity was improved by about 30% compared to the conventional method.

Furthermore, regarding the irradiation uniformity in the length direction of the electric wire, the first
In the first invention, compared to the irradiation amount during steady speed operation, when the electronic cutoff device is operated, there is no practical problem in the range of approximately ±15%, and furthermore, in the second invention, it is extremely uniform within ±8%. It was confirmed.

The details of the present invention have been described using an example of a two-course wire irradiation process, but in a general n-course irradiation process, in equation (1), i _x = 1/ni ₀ − i ₁ − i ₂ and the same Needless to say, the present invention can be used not only for electric wires but also for tube, film, and sheet irradiation processes.

As explained above, the present invention is an extremely effective device for improving the productivity of electron beam irradiation processes.

[Brief explanation of the drawing]

Figure 1a is a front view showing a conventional irradiation device;
Figure b is a plan view of the same, Figure 2 a is a front view of the irradiation device using an electron blocking device, Figure 2 b is a plan view of the same, Figure 3 is a density distribution diagram of the electron beam, and Figure 4 is a diagram of the density distribution of the electron beam.
FIG. 5 is a front view of an irradiation device showing an embodiment of the present invention. The numbers used in the diagram are commonly used; 1 is the electron accelerator, 2 is the electron emission tube,
4 and 5 are electric wires, 8 is an electronic cutoff device, 15 and 18
indicates an arithmetic processing unit.

Claims (1)

[Scope of Claims] 1. In an electron beam irradiation device comprising an electron accelerator and an electron blocking device between an electron emitting tube of the electron accelerator and an irradiated object crossed in a direction transverse to the scanning plane of the electron beam. , the output electron beam current of the electron accelerator
i ₀ , a scattered electron beam current i ₁ to the electron emission tube section, and an electron beam current i ₂ flowing to the electron cutoff device, and from these current values, it is possible to determine the intersection of the cross-overs among the n courses. It is equipped with a calculation device that calculates the current i _x to the irradiated object for one course of nearby irradiation from the formula i _x = i ₀ /n-i ₁ - i ₂ , and calculates the moving speed of the irradiated object by i An electron beam irradiation device characterized by comprising a control device that can be operated in proportion to _x . 2. In an electron beam irradiation device equipped with an electron cutoff device between an electron accelerator and an irradiated object crossed in a direction across the electron emission tube of the electron accelerator and the scan plane of the electron beam, the output electrons of the electron accelerator are line current
i ₀ , a scattered electron beam current i ₁ to the electron emission tube section, and an electron beam current i ₂ flowing to the electron cutoff device, and from these current values, it is possible to determine the intersection of the cross-overs among the n courses. An arithmetic device that calculates the current i _x to the irradiated object for one course of nearby irradiation from the formula i _x = i ₀ /n-i ₁ - i ₂ , and an arithmetic device that calculates di _x /dt. and a control device that can control the moving speed of the irradiated object in proportion to i _x and di _x /
An electron beam irradiation device comprising a device that controls the moving speed of an electron cutoff device so that the calculated value of dt becomes approximately constant.