JP2002097518A - Internal hardening equipment - Google Patents

Abstract

(57) [Problem] To provide an inner surface quenching device capable of uniformly quenching the inner surface of a cylindrical object to be heated. SOLUTION: A straight inductor 2 made of a hollow copper pipe is vertically established at the center of a lower electrode 1 and a cylindrical heat object 4 is set on the lower electrode. The object to be heated is sandwiched by the upper electrode 3 provided so as to face the lower electrode, and a high-frequency current is applied to the inductor, and at the same time, an electric current is applied to the object to be heated to induce induction heating. And heating the object to be heated by the combined use of heating and electric heating, and then quenching water into the object from the fountain port 6 provided in the upper electrode to rapidly cool the inner surface of the object. By providing quench water diffusing means for diffusing the quench water to the outer periphery of the fountain port, the quench water is uniformly jetted to the upper portion 8 of the inner surface of the object to be heated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for uniformly hardening the inner surface of a cylindrical object to be heated such as a pump cylinder and a bearing.

[0002]

2. Description of the Related Art Generally, mechanical parts are generally heated by a heat treatment furnace and quenched as a whole. However, when the whole is heated and quenched by a heat treatment furnace, subsequent machining such as cutting may not be easy. For this reason, it has been conventionally known that a high-frequency induction heating device is used to partially heat machine parts and harden only required parts. For example, it is an inner surface hardening device for hardening only the inner surface of a cylindrical heat target such as a pump cylinder and a bearing.

[0003]

In such quenching, it is important to uniformly cool the inner surface of the object to be quenched, together with the uniform heating of the inner surface of the object, to maintain the quality of the object. However, in the conventional internal quenching apparatus, the flow rate (flow velocity) of quenching water flowing from the upper electrode to the inner surface of the object to be heated near the upper electrode is small, so that the cooling property of this portion is poor and the hardness is low. There is a possibility that a defective product is generated due to a local shortage. An object of the present invention is to solve the above-mentioned problems and to provide an inner surface quenching apparatus capable of uniformly quenching the inner surface of a cylindrical object to be heated.

[0004]

For this purpose, the internal quenching apparatus according to the present invention vertically establishes a straight inductor made of a hollow copper pipe at the center of the lower electrode, and places a cylindrical heat-receiving object on the lower electrode. And the inductor is inserted into the object to be heated, and the object to be heated is sandwiched by an upper electrode provided so as to face the lower electrode, and a high-frequency current flows through the inductor. At the same time, the object to be heated is energized, and the object to be heated is heated by a combination of induction heating and energizing heating. Then, quenching water is injected into the object to be heated from a fountain port provided in the upper electrode. A device for rapidly cooling the inner surface of a heated object, wherein quench water is uniformly sprayed to the upper portion of the inner surface of the object to be heated by providing a quenched water diffusing means for diffusing the quenched water to the outer periphery at the fountain port. It is characterized by. Further, the present invention is characterized in that, in the above internal quenching apparatus, the quenching water diffusing means forms a spiral groove on the inner surface of the fountain port. Further, the present invention is characterized in that, in the above internal quenching apparatus, the quenching water diffusing means is provided with a tubular body inside the fountain port. Further, the present invention is characterized in that, in the inner surface quenching apparatus, the quenching water diffusing means is provided with a flange-shaped body on the outer periphery of the inductor near the fountain port.

[0005]

Embodiments of the present invention will now be described with reference to the drawings. As shown in the longitudinal sectional view of FIG. 1, this internal quenching apparatus comprises a lower electrode 1 and a straight inductor 2 made of a hollow copper pipe vertically established at the center of the lower electrode.
And the upper electrode 3. Reference numeral 4 denotes a substantially cylindrical heat object made of martensitic high-nitrogen stainless steel, and the heat object is concentrically sandwiched between the lower electrode 1 and the upper electrode 3.
The inductor 2 is inserted through the center.

The upper electrode 3 has a water inlet 5 for introducing quenching water, and a fountain opening 6 connected to the water inlet and opening around the upper part of the inductor 2. A spiral groove 7 is formed on the inner surface of the fountain port 6.

In this internal quenching apparatus, 10
By passing a high-frequency current of 0 kHz and 110 kW, an induced current is generated on the inner surface of the object to be heated 4, and the inner surface of the object to be heated 4 is induction-heated. The object to be heated 4 is electrically heated by applying an AC power supply. The power ratio between the induction heating and the electric heating is about 2: 1, whereby the inner surface of the object to be heated 4 can be heated to 1150 ° C. to 1200 ° C. in about 3.8 seconds.

Then, the quenched water is introduced from the water inlet 5 and jetted into the heated object 4 from the fountain port 6 to rapidly cool the heated object. At this time, the quenching water flowing down in the fountain opening 6 turns along the spiral groove 7 and diffuses by centrifugal force when squirting from the opening end thereof, and is sprayed on the upper inner surface 8 of the object to be heated 4. For this reason, a large amount of quenching water spouted from the fountain port 6 is also jetted to the upper portion 8 of the inner surface of the object to be heated 4 so that the inner surface of the object to be heated can be uniformly and rapidly cooled. Thereby, the inner surface of the object to be heated 4 can be hardened to a hardness of HV700 or more. On the other hand, the outer peripheral portion of the object to be heated 4 does not have such quenching and hardening, and post-processing such as cutting and drilling can be easily performed.

On the other hand, the embodiment shown in FIG.
A cylindrical body 9 is provided inside the cylindrical body to make it easy for the quenching water to turn along the spiral groove 7, and the quenching water collides with a flange 10 formed on the outer periphery of the lower end edge of the cylindrical body 9 to scatter. This is to make it easier for incoming water to spread outward.

The embodiment shown in FIG.
A flange 11 is provided on the outer periphery of the inductor 2 in the vicinity, and quenching water spouted from the fountain port 6 hits the flange 11 and scatters outward to adhere to the upper portion of the inner surface of the heat target 4. ,
Even by adopting such a quenching water diffusion means, uniform rapid cooling can be achieved.

[0011]

As described above, in the internal hardening apparatus according to the present invention, a straight inductor made of a hollow copper pipe is vertically established at the center of the lower electrode, and a cylindrical heat-receiving object is set on the lower electrode. And penetrate the inductor into the object to be heated,
The object to be heated is sandwiched by an upper electrode provided so as to face the lower electrode, and a high-frequency current is supplied to the inductor, and at the same time, the object to be heated is energized and the induction heating and the energization heating are used in combination. A device for injecting quenching water into the heated object from a fountain port provided in the upper electrode after heating the heated object and rapidly cooling the inner surface of the heated object, wherein the quenched water is supplied to the fountain port at an outer periphery thereof. Since the quenching water is uniformly sprayed to the upper portion of the inner surface of the object to be heated by providing quenching water diffusing means for diffusing the material, the inner surface of the object to be heated is rapidly cooled uniformly, and the quench hardening becomes uniform. There is a beneficial effect of improving the quality.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an internal hardening apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment of the internal hardening device according to the present invention.

FIG. 3 is a longitudinal sectional view showing another embodiment of the internal hardening apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower electrode 2 Inductor 3 Upper electrode 4 Heated object 6 Fountain port 7 Spiral groove 8 Inner upper part 9 Cylindrical body 11 Flange-shaped body

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C21D 9/40 C21D 9/40 A H05B 3/00 340 H05B 3/00 340 6/10 331 6/10 331

Claims (4)

[Claims] 1. A straight inductor made of a hollow copper pipe is vertically established at the center of a lower electrode, a cylindrical object to be heated is set on the lower electrode, and the inductor is placed in the object to be heated. At the same time, the object to be heated is sandwiched by an upper electrode provided so as to face the lower electrode, and a high-frequency current is applied to the inductor, and at the same time, electricity is applied to the object to be heated, so that induction heating and electric heating are performed. A device for heating the object to be heated in combination with the above, and then quenching water into the object to be heated from a fountain port provided in the upper electrode to rapidly cool the inner surface of the object to be heated, wherein the fountain port A quenching water diffusing means for diffusing the quenching water to the outer periphery, so that the quenching water is uniformly sprayed to the upper portion of the inner surface of the object to be heated. 2. The internal quenching apparatus according to claim 1, wherein the quenching water diffusing means has a spiral groove formed on an inner surface of the fountain port. 3. The internal quenching apparatus according to claim 1, wherein the quenching water diffusion means has a tubular body provided inside the fountain port. 4. The inner surface quenching device according to claim 1, wherein the quenching water diffusing means is provided with a flange on the outer periphery of the inductor near the fountain port.