JPH06128624A - High frequency induction hardening device - Google Patents

Abstract

PURPOSE:To reduce the vapor film of cooling liquid generated on the surface of a material to be quenched by cavitation with ultrasonic energy and to improve the quenched hardness by enabling the injection of the cooling liquid from the outer periphery at the tip part of an ultrasonic horn arranged at the discharging side of a high frequency induction heating coil. CONSTITUTION:The doughnut-like ultrasonic horn 1 is arranged at the discharging side of the doughnut-like high frequency induction heating coil 14. On the outer peripheral surface at the tip part of this horn 1, a liquid storing part 9 for cooling liquid 19 injected from the above surface is arranged. Then, by the cavitation with the ultrasonic energy, the vapor film of the cooling liquid 19 generated on the surface of the material 15 to be quenched is reduced and the material is cooled within the prescribed time and the quenched hardness is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction hardening apparatus for improving the wear resistance of metal surfaces.

[0002]

2. Description of the Related Art Induction hardening heating is characterized in that a high frequency current flows to a depth from the surface of an object to be hardened depending on the frequency used and surface heating is performed by electric resistance. The quenching depth can be calculated by the frequency used,
Usually used to improve the wear resistance of surfaces. For example, in FIG.
As shown in FIG. 5, the material to be quenched B is passed through the center of the doughnut-shaped high-frequency heating coil A to heat the surface, and is cooled by the injection cooling liquid C injected from a part of the high-frequency heating coil A. The injected cooling liquid C is cooled by a cooling pipe G communicating with a cooler F and sent to a conduit J via an injection pump H and a filter I. The jet cooling liquid C after cooling is returned to the receiving cooling liquid tank D by the receiving tray K. In the apparatus, the high frequency current was determined according to the frequency used for calculation, heated to about 860 ° C., and the jet cooling liquid C was jetted for cooling.

[0003]

When a cooling liquid is sprayed onto a material to be hardened, a vapor film of the cooling liquid is generated on the surface of the material to be hardened, and the film is not cooled to a predetermined temperature within a predetermined time. Sometimes. Since the material to be quenched transfers heat from a high temperature to a low temperature with the passage of time, there is a problem that a predetermined quenching hardness cannot be obtained unless it is cooled immediately after being heated at a predetermined heating temperature. Therefore, if the material to be quenched is not cooled within the predetermined time as described above, a soft transformation forming structure is generated, and the predetermined quenching hardness cannot be obtained. Therefore, the present invention is intended to provide an apparatus capable of improving the quenching hardness by reducing the vapor film generated in the cooling liquid.

[0004]

In order to solve the above-mentioned problems, the present invention provides a donut-shaped ultrasonic horn on the discharge side of a donut-shaped high-frequency heating coil, and the tip outer peripheral surface of the ultrasonic horn, The induction hardening device is provided with a liquid retention part for the cooling liquid injected from the outer periphery of the tip of the ultrasonic horn,
In addition, the central part of the ultrasonic horn is formed into a frusto-conical shape, and a donut-shaped side plate for holding the ultrasonic horn is provided on the outer periphery of the ultrasonic horn. And an induction hardening apparatus in which the liquid retention portion of the cooling liquid is formed by changing the angle.

[0005]

The present invention is configured as described above, in which the material to be hardened is heated to a predetermined temperature by the high frequency heating coil while moving, and the cooling liquid which receives the ultrasonic energy from the ultrasonic horn is discharged from the liquid retention portion. It is sprayed onto the surface of the material to be quenched and cooled within a predetermined time.

[0006]

Embodiments of the present invention will be described in detail with reference to FIGS. A frustoconical irradiation part 2 is formed on the irradiation side of the doughnut-shaped ultrasonic horn 1, and ring-shaped partition parts 3, 3 ′ are projected on both sides of the irradiation part 2. A large number of ultrasonic transducers 4, 4, ... Are fixed at intervals on the side opposite to the irradiation surface of the ultrasonic horn 1.

The ultrasonic horn 1 has side plates 5 and 5'on both sides.
Are fixed by spacers 6, 6, ... Provided between the ultrasonic transducers 4, 4 ,. The side plates 5 and 5'on both sides each have a donut shape and are provided with inclined portions 7 inclined toward the center on the center side. The inner inclined surface 8 of the inclined portion 7 changes the inclination and angle of the irradiation portion 2 of the ultrasonic horn 1 to form a liquid retention portion 9, and the discharge side is cooled by forming a small space between the irradiation portion 2 and the irradiation portion 2. The liquid can be jetted. The partition parts 3 and 3'are side plates 5 and 5, respectively.
It is fitted into the fitting grooves 10 and 10 'provided in the ??? Further, both side plates 5 and 5'are made to communicate with the liquid retaining portion 9 by forming cooling liquid supply ports 12 and 12 'at a plurality of places respectively, so that the cooling liquid can be supplied. Reference numeral 13 in the drawing denotes a cover provided on the outer periphery of the side plates 5, 5 '.
The cooling device is configured as described above, and the doughnut-shaped high-frequency heating coil 14 is provided on the introduction side of the cooling device so that the material to be hardened 15 can be heated.

Below the induction hardening apparatus constructed as described above, a pan 16 is installed to receive the jet cooling liquid, and the pan 16 is connected to a cooling liquid tank 18 via a connecting pipe 17. Connected. The cooling liquid 19 in the cooling liquid tank 18 is cooled by a cooling pipe 21 communicating with a cooling refrigerator 20, and a conduit 24 is provided via an injection pump 22 and a filter 23.
Are supplied to the cooling liquid supply ports 12, 12 ', ....

This embodiment is constructed as described above,
The material to be quenched 15 (60 φ of S55C is used in the embodiment) is moved in the direction of the arrow in FIG. This is high-frequency heating by the high-frequency heating coil 14 while moving a predetermined temperature (frequency of about 55KH _Z about 860 ° C.) are heated to. On the other hand, the cooling liquid 19 of about 25 ° C. accumulated in the liquid retaining portion 9 receives ultrasonic energy from the tip due to the vibration of the ultrasonic horn 1 by the ultrasonic vibrators 4, 4, ... Spray on the surface of.

This jet cooling liquid reduces the vapor film of the cooling liquid generated on the surface of the material to be hardened by cavitation by ultrasonic energy. A comparison between the quenching hardness according to the embodiment and the conventional quenching hardness shows a difference in hardness as shown in FIG. The injection angle of the injection cooling liquid is determined by the angle of the inner inclined surface 8 of the side plates 5, 5 ', but by selecting this angle, cooling can be effectively performed.

[0011]

Since the present invention has the above-described structure and operation, the cooling liquid to be injected has ultrasonic cavitation, and the injection cooling liquid by cavitation is applied to the material to be hardened by the conventional cooling method. The vapor film caused by the cooling liquid generated on the surface of the container is remarkably reduced, and the contact pressure is increased by cavitation, so that it can be cooled to a predetermined temperature within a predetermined time, and the quenching hardness can be improved.

[0012]

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an induction hardening apparatus according to the present invention.

FIG. 2 is a front view in which a part thereof is cut away.

FIG. 3 is a diagram showing a hardness comparison between the present invention and a conventional example.

FIG. 4 is a vertical cross-sectional view of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic horn 2 Irradiation part 3 Partition part 3'Partition part 4 Ultrasonic transducer 5 Side plate 5'Side plate 6 Spacer 7 Inclined part 8 Inner inclined surface 9 Liquid retention part 10 Fitting groove 10 'Fitting groove 11 O-ring 11' O Ring 12 Cooling liquid supply port 12 'Cooling liquid supply port 13 Cover 14 High frequency heating coil 15 Hardened material 16 Saucepan 17 Connection pipe 18 Cooling liquid tank 19 Cooling liquid 20 Cooling refrigerator 21 Cooling pipe 22 Injection pump 23 Filter 24 Conduit

Claims (2)

[Claims] 1. A doughnut-shaped ultrasonic horn is provided on the discharge side of a donut-shaped high-frequency heating coil, and a liquid retention portion for cooling liquid jetted from the outer circumference of the tip of the ultrasonic horn is provided on the outer peripheral surface of the tip of the ultrasonic horn. Induction hardening equipment, characterized in that 2. A central part of the ultrasonic horn is formed into a truncated cone shape, a donut-shaped side plate for holding the ultrasonic horn is provided on the outer periphery of the ultrasonic horn, and an inner inclined surface is provided on the central part side of both side plates. The induction hardening apparatus according to claim 1, wherein the liquid retaining portion for the cooling liquid is formed by changing the angle with respect to the inclined surface.