JPH0717941B2 - Quenching method with electron beam - Google Patents

Description

The present invention relates to an electron beam quenching method for irradiating an electron beam to quench the surface of carbon steel or the like.

[Conventional technology]

FIG. 3 shows an apparatus for a hardening method by irradiation with a point group of an electron beam as disclosed in, for example, Japanese Patent Laid-Open No. 54-95908, which includes an electron gun (1), a focusing electromagnetic lens (2), The deflection electromagnetic coils (3) are arranged coaxially with each other. The work piece or the jig (4) on which a plurality of work pieces are placed is
The work table is placed on a work table (5) for moving the work piece, and the work table (5) is driven by a serve motor (6). (7) is a servo drive source. A beam focusing and deflection amplifier (8) is connected to the focusing electromagnetic lens (2) and the deflection electromagnetic coil (3). (9) is a high voltage power supply. The vacuum chamber (10) accommodates the work table (5) and the workpiece, and performs processing. (11) is the exhaust system. (12) is required for electron beam equipment such as beam deflection program, control of parameters related to electron gun such as acceleration voltage, beam current, control current of focusing electromagnetic lens and control command of vacuum chamber exhaust system and work table drive system All the control devices are usually composed of a numerical control (NC) including a computer for a beam deflection program, a sequencer and the like.

A conventional electron beam hardening method using the above apparatus will be described. For example, when surface hardening is performed on the doughnut-shaped portion (4b) shown by hatching of the coin-shaped workpiece (4a) as shown in FIGS. 4 and 5, as shown in FIG.
Irradiate the beam in a donut pattern. As a method of irradiation, after the beam is retained in one place for 5 to 50 μsec,
A large number of doughnut-shaped heat sources (4c) are driven into the donut-shaped entire surface by moving the beam to the next point at a high speed and staying there. Of course, as conditions necessary for electron beam quenching, parameters such as beam accelerating voltage, beam current, beam focus point, and beam irradiation time are controlled so that quenching can be performed without melting the surface of the workpiece (4a). Raise to temperature.

Further, when processing a large number of workpieces with one chamber, as shown in FIG. 7 and FIG. One method is to set the work and then sequentially process while indexing and moving on the NC table.

At this time, the workpiece (4a) is placed at a position where the beam axis of the electron gun (1) and the reference point of the machining pattern coincide with each other.
The beam is turned on again after moving to the next workpiece position
To be done.

[Problems to be solved by the invention]

In the conventional quenching method using an electron beam, when processing multiple workpieces in one chamber, after turning on the beam axis of the electron gun after aligning the reference point of the processing pattern for each workpiece with the beam axis of the electron gun. Then, the beam is turned off once the processing is completed, the work table (5) is mechanically moved to the next processing position, and the beam is turned on to process the next workpiece. I needed to do it.

Therefore, in addition to the quenching processing time, it takes time to move the workpiece, and while the beam is turned on and reaches a steady state, the beam output, focus point, and beam irradiation position become unstable, There were problems such as non-uniform heat input to the workpiece.

The present invention has been made to solve the above-mentioned problems, and it is possible to continuously perform quenching treatment in a short time without turning the beam on and off, and without moving the table in correspondence with the workpiece. The purpose is to obtain a quenching method with an electron beam that can be performed.

[Means for solving problems]

In the quenching method using an electron beam according to the present invention, a mounting seat of a jig for setting a workpiece is formed by an inner surface of a sphere having a center of a deflection angle of a deflection electromagnetic coil as a center of a radius, and an electron beam is placed at a predetermined position. By vector deflection and high-speed deflection to a point group corresponding to a predetermined hardening pattern, the workpiece can be sequentially deflected without beam turning and without beam OFF without mechanically indexing and moving the workpiece. Turn on.

[Action]

In the present invention, it is possible to eliminate the loss time due to mechanical indexing and to eliminate the non-uniformity of the quenching conditions during the transitional period due to the ON / OFF of the beam. Further, the difference in the quenching conditions depending on the size of the beam deflection angle is minimized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, an electron beam generator is formed by a cathode (1a) and an anode (1b). Mounting jig (4) in which a plurality of workpieces (4a) are concentrically set
Is the radius (R) centered on the center (A) of the beam deflection angle
The inner surface of the ball is used as the mounting seat (41). A beam collector (13) made of a copper block or the like having a large heat capacity is embedded in the inner surface of the sphere of the mounting jig (4).

Other than the above, the same reference numerals as in FIG.
The description is omitted.

The quenching method using the above apparatus will be described. Now, for example, the hatched portion (4b) of the coin-shaped workpiece (4a) as shown in FIGS. 4 and 5 which is the same as that described in the conventional method.
When quenching, the jig (4) placed on the work table (5) is set with a plurality of workpieces (4a), and the center of the jig (4) is aligned with the axis of the electron gun. Move the work table (5).

Next, turn on the electron beam on the beam collector (13),
The beam is deflected onto the workpiece (4a) after a time (usually within 1 sec) when the beam characteristics become stable, and the point cloud irradiation is performed under preset processing conditions. Although it depends on the size of the work piece (4a) and the quenching depth, etc.,
The beam residence time per dot is 5 to 50 μsec, the dot-dot pitch is about 0.2 to 1 mm, and the beam irradiation time is about 1 to 5 sec. Beam irradiation time interval No. 6
Since the beam energy can be continuously irradiated while moving to the required pattern as shown in the figure, the entire pattern is consequently zone-heated.

Here, the plurality of workpieces are arranged on concentric circles in a plane as shown in FIG. 2, and when viewed from a cross section, the deflection center point (A) is the center and the radius ( R) is arranged on the inner surface (41) of the sphere. The machining program is subjected to planar circumferential vector control (θ1, θ2) and lateral deflection angle control (α, β), and the beam axis is sequentially vector-deflected to the center of each workpiece (4a). At the same time, the point cloud is irradiated with a dot beam under the processing conditions preset for each workpiece (4a). When the processing of all the workpieces (4a) is completed, the beam will move to the beam collector (1
It is returned to the position of 3) and turned off.

The beam is kept ON until the above series of steps, that is, the quenching of all the workpieces (4a) is completed,
In addition, during that time, the work table (5) is not moved, and the irradiation position is moved only by the high-speed deflection of the beam, so that the loss time for moving from one workpiece to the next workpiece does not require 1 μsec. Therefore, it is practically nothing and is extremely efficient as compared with the work table moving method.

Next, if the work set jig (4) is a flat surface, differences in beam deflection angles (α, β) will cause differences in processing distance (WD) and irradiation angles (r1, r2). By installing the mounting seat (41) for the workpiece (4a) on the tangent line of the inner surface of the centripetal with the radius (R) centered on the deflection center point (A), regardless of the deflection angle, quenching conditions Are the same.

In the above embodiment, the case of quenching a plurality of workpieces of one type has been described, but the number of workpieces is not necessarily 11 and the quenching conditions may be different for each workpiece. it can.

Also, I explained the method of returning the beam to the position of the beam collector and turning it off when all the workpieces are processed,
OFF on final work piece without returning to beam collector position
But it doesn't matter.

〔The invention's effect〕

As described above, according to the present invention, when a plurality of workpieces are machined by one chamber, the plurality of workpieces are hardened without moving the work tebules like the workpieces. The instability of the processing conditions caused by turning ON and OFF can be eliminated, the lost time due to table movement can be eliminated, and highly efficient and highly accurate quenching processing can be realized.

Furthermore, since a plurality of workpieces are mounted on the inner surface of the sphere of the mounting jig, there is an effect that the quenching conditions do not differ due to the difference in beam deflection angle.

[Brief description of drawings]

FIG. 1 is a front sectional view of an apparatus for explaining an embodiment of the present invention, and FIG. 2 is a sectional view taken along a line II-II in FIG. 3 to 8 are for explaining a conventional quenching method by an electron beam, FIG. 3 is a circuit diagram of the apparatus, FIG. 4 is a plan view showing a quenching mode of a workpiece, FIG. Figure 5 shows V in Figure 4
FIG. 6 is a cross-sectional view taken along a plane along the line -V, FIG. 6 is a point cloud pattern when irradiating a donut with dots, and FIG. The drawing is a sectional view taken along a line VIII-VIII in FIG. (1) ... electron gun, (2) ... focusing electromagnetic lens, (3)
…… Deflection electromagnetic coil, (4) …… Mounting jig, (4a) ……
Workpiece, (41) ... Mounting seat consisting of the inner surface of the sphere. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a method of quenching a plurality of workpieces using an electron beam apparatus including an electron gun having a means for focusing and deflecting an electron beam, a mounting seat of a jig for setting the workpieces. By forming an inner surface of a sphere with the center of the deflection angle of the deflection electromagnetic coil as the center of radius, vector-deflecting the electron beam to a predetermined position, and high-speed deflection to a point group corresponding to a predetermined hardening pattern. A quenching method using an electron beam, wherein quenching is sequentially performed only by beam deflection without mechanically indexing and moving the workpiece, and without turning off the beam.