JPS59232216A - High frequency hardening method - Google Patents

Abstract

PURPOSE:To subject simultaneously plural heat-treating points with different heating time to a heat treatment with one oscillator by heating the points requiring short-time heating with semi-looped heating coils which can be detached from a work in optional time. CONSTITUTION:A high frequency hardening device consisting of one oscillator 10, current transformers 20, 30, a work coil 50 and a work coil 40 of a semi-loop type is prepd. A work 60 having plural heat treating points A, B with different heating time is simultaneously heat-treated with such hardening device. The point requiring short-time heating is heated by the coil 40 and the coil is detached from the work 6 upon lapse of the required heating time. The plural heat- treating points with different heating time are simultaneously heat-treated with one oscillator by the above-mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to an induction hardening method, and in particular, when one oscillator is used, it is possible to heat-treat a workpiece having multiple locations with different heating times. Regarding the quenching method.

(B) Prior art The applicant has already filed a patent application for a method of heat treating multiple locations with different shapes and dimensions using a single oscillator and an output balancer (Japanese Patent Application No. 53-66363).
issue).

However, since the method described in the above patent application uses one oscillator for heat treatment, the heating time for multiple locations on the workpiece is the same, so it is not applicable if the heating time for the multiple locations is different. The drawback is that it cannot be done.

(c) Purpose The present invention has been made to eliminate the above problems,
The object of the present invention is to provide an induction hardening method that allows a single oscillator to heat treat a workpiece having a plurality of heat treatment openings each having a different heating time.

Another object of the present invention is that one oscillator can be used even if the heating times are different, so that the equipment and construction period can be reduced.

(D) Structure The invention according to this patent application provides a plurality of heat treatment locations using one oscillator, a plurality of current transformers connected in series to the oscillator, and a work coil connected to each of the plurality of current transformers. In the induction hardening method of simultaneously hardening workpieces, if the heating time is longer or shorter, the work coil for the part to be heated for a short time is a semi-loop, and after the heating by the semi-loop work coil is finished, the semi-loop work coil is This is an induction hardening method in which the workpiece is separated from the workpiece and the remaining heat treatment related to the separation can be changed to preset conditions so as to obtain the desired hardening result.

(B) Embodiment FIG. 1 is an explanatory diagram showing the case of one-shot quenching, which is an embodiment of the invention related to this patent application, in which 10 is an oscillator, 20
．． Reference numeral 30 denotes a current transformer connected in series to the oscillator 10, and work coils 40 and 50 are respectively connected to the current transformers 20 and 30 by feeders.

Reference numeral 60 denotes a workpiece having a plurality of heat treatment locations, where the heat treatment location A is the work coil 4o, and the heat treatment location B is the work coil 4o.
are heat-treated by one-shot quenching using the work coil 5o.

The work coil 40 is of a semi-loop type, and as a result of the current transformer 20 retreating after heating, the work coil 40 fixed to the current transformer is configured to be able to retreat in the direction of the work in order to separate from the work. .

At the same time as the work coil 4o is removed, the heat treatment area A is rapidly cooled from the cooling liquid injection jacket through a solenoid valve or the like from a cooling liquid supply device (not shown).

On the other hand, in response to the removal of 81 of the work coil 4o, the heat treatment location B was automatically switched to the second stage hardening conditions that were preset to obtain the desired hardening results, and subsequent heating work was performed. It is then rapidly cooled to complete the first heat treatment operation.

Reference numeral 70 denotes a mint switch provided in connection with the work coil 4o, and this switch 70 is configured to actuate ONL and a controller 80 connected to the work coil 50 upon contact when the work coil 40 is retracted. .

Here, the controller 80 can adopt a known method of controlling the power supplied to the work coil 50 by adjusting the oscillation conditions of the oscillator, for example, the input voltage to the high frequency oscillation tube or SIRISK as the control element.

In addition, the controller is equipped with a so-called output balancer as described in the above-mentioned patent application, that is, a feeder wire to the work coil is wound in appropriate turns to concentrate high-frequency magnetic flux there, and an appropriate load is inserted into and removed from the high-frequency magnetic flux. By doing so, a means for generating a desired high frequency loss is applied.

Next, other embodiments according to the present invention will be described.

FIG. 2 has the same configuration as FIG. 1, but the difference from FIG. 1 is that it shows a case where the work is heated while moving relative to the work coil, that is, a case of moving hardening.

In this figure, the same reference numerals as in FIG. F represent the same parts.

In FIG. 2, it is assumed that the heat treatment time (the moving direction is in the middle direction) of the work coil 40 (semi-loop type work coil) corresponding to the heat treatment location A is shorter than that of the work coil 50 of the heat treatment location B. do.

Therefore, when the work coils 40 start from their respective left ends a and b at the same time and arrive at the right end a' of the heat treatment location A (that is, when the heating of the heat treatment location A is completed), the work coil 50 has not reached the right end b′ yet; The robot is moving halfway through processing location B.

At this point, when heating of the heat treatment area A is completed, the work coil 40 is retracted in the direction away from the workpiece by actuation of a Mitswitch 90 provided in association with the work coil 40.

This retraction turns on the limit switch 70, which switches the transmission 100 that affects the movement of the work coil 50 to change the movement speed of the work coil 50. This change in moving speed suppresses the change in impedance due to the retraction of the work coil 40, that is, the load fluctuation seen from the oscillator. Note that, instead of changing the moving speed of the work coil 50, the oscillation conditions of the oscillator, for example, the input voltage to the high frequency oscillation tube or the SIRISK as the control element, are adjusted to adjust the movement speed of the work coil 50, as in the above-described embodiment.
A known method for controlling the power supplied to can also be adopted.

In addition, although one-shot hardening or moving hardening has been described as an example, the present invention can be used, for example, when heat-treated area A is simultaneously hardened in one shot and heat-treated area B is moved-quenched. B
It goes without saying that this method can also be applied even when quenching is performed in one shot.

(f) Effects Since the present invention is configured as described above, a plurality of heat treatment locations can be heat treated with different heating times using one oscillator, so the degree of freedom in heat treatment can be increased. This is extremely effective in terms of reducing the burden on equipment and shortening the time required for one process.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of one-shot quenching, Fig. 2
The figure is an explanatory view showing an example in which the work is heated while moving relative to the work coil, that is, in the case of moving hardening. 10... Oscillator, 2o, 3o... Current transformer, 40.50... Work coil, 7°... Limit switch, 8o... Controller. 90... ・Limit switch. Patent Applicant Fuji Electronics Co., Ltd. Agent Patent Attorney Takaharu Ohnishi Figure 1 Figure 2 00

Claims (1)

[Claims] (1) Simultaneously induction hardening a workpiece having a plurality of heat-treated locations using a number of oscillators, a plurality of current transformers connected in series to the oscillators, and a work coil connected to each of the plurality of current transformers. When,
An induction hardening method characterized in that, in cases where the induction heating time G is longer or shorter, the heating coil at the location requiring short-term heating is made into a semi-loop and is separated from the workpiece after the required heating time has elapsed.