JPS58100628A - Less-strain and high-frequency quenching device for annular parts - Google Patents

Abstract

PURPOSE:To reduce quenching strain and to eliminate the need for a straightening process by restricting outer circumferential recessed parts of parts with chiller energized by springs in the high frequency quenching of inner circumference parts of the annular parts which has recessed and projecting parts at the outer circumferential part. CONSTITUTION:The inner circumferential surface of annular parts 1 which have projecting parts 1a and recessed parts 1b at the outer circumferential part is quenched by a high frequency heating coil 2. In this case, chiller 3 are provided at positions corresponding to the outer circumference recessed parts 1b of the annular parts 1. The chiller 3 are held in the recessed padrts 5a of a chiller holding device 5, and energized through springs 4 to press the outer circumference of the annular parts 1. The restriction by those chiller 3 reduces high- frequency quenching strain to eliminate or decrease the need for number of man-hour a straightening process, machining, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for induction hardening an annular part, and in particular, the invention relates to an apparatus for induction hardening an annular part. Low distortion of the annular part is induced by induction hardening II.
& Concerning the box.

Generally, when the inner peripheral part of an annular component having irregularities on the outer periphery is induction hardened, distortion occurs due to transformation stress and thermal stress during hardening. The main cause of this distortion is that the mass and heat capacity are different between the concave portion and the convex portion on the outer circumference of the annular component, so a temperature difference occurs between the concave portion and the convex portion during high-frequency heating of the inner circumference.
This is because thermal distortion and thermal stress occur due to this temperature difference.

Generally, the above-mentioned quenching distortion II'i is corrected by a hydraulic press or mechanical external force after quenching. Also, some
Dimensional accuracy is ensured by cutting, grinding, etc. after quenching, which causes a significant decrease in productivity 1 and increases the manufacturing cost of the product.

In addition, in order to reduce the quenching distortion of Stt.
Outer station for circular parts! Attempts have also been made to use a press wrench to completely restrain the press wrench from the outside, but this has the disadvantage of requiring a complicated control mechanism and is not sufficiently effective.

The present invention addresses one or more such problems.

We provide an induction hardening device that can greatly reduce quenching distortion,
The purpose is to eliminate the need for a strain relief process and significantly improve productivity.

Achieving this objective t Next, 1. In the low strain induction hardening apparatus l' for annular parts of the present invention, the outer circumferential recess of the annular part having an uneven shape on the outside is restrained by a spring-loaded chiller. In this state, the inner peripheral surface is subjected to induction hardening.

This makes the temperature distribution of the concave and convex parts of the annular part uniform, suppresses the occurrence of distortion due to variations in temperature distribution, and further increases the 1w# tension by generating large transformation stress and thermal stress due to the reaction force of the spring. It is designed to be able to be absorbed without any problems.

A preferred embodiment ta of a low strain induction hardening apparatus for annular parts according to the present invention will be described below.

The figure shows a cross section of an apparatus O according to an embodiment of the present invention. In the figure, IF! An annular part with a convex portion 1a and a concave portion 1b on its outer periphery.
The inner surface is hardened by the high frequency heating coil 2. A cooling metal 3 is provided at a position corresponding to the recess 1bVc on the outer periphery of the annular component 1, and is held in a recess W5a of a cooling retaining device 5 disposed at the outer periphery of the annular component 1. It is supported so that it can move forward and backward. A spring 4 is interposed between the chiller 3 and the bottom surface of the recess 11s 5a, and urges and presses the chiller 3 against the outer part of the annular part. Cold gold 3tl! .

The surface of the annular component on the side of the outer circumferential recess 1b is formed to have the same curvature as the recess 1b, so that it can closely contact the outer surface of the recess It).

Next, test examples of the present invention will be described. ,first.

Convex outer diameter 15 made of JISS45G carbon steel for machine structures
An object to be heated having a diameter of 1 mm, an inner diameter of 143 M1, an inner diameter of 121 mm, and a height of 15 mm is attached to the recess through a nine-chilled metal 3 with the same curvature as 0, and a spring with a spring constant of λOKg/mm is installed in the holding device 15. Then, a high-frequency heating coil V with an outer diameter of 119 mm and a height of 12 mm is attached to the bale in which the W heating object is fully restrained.
1 frequency IQQKHg from C, heating power 134 31 with armor
! Immediately after IOC heating, water jet quenching was performed. The amount of dimensional change at this time is shown in Table 10 Test Example 1. Table 1tli shows the amount of change in the outer diameter of the convex portions and concave portions before and after induction hardening.

In addition, the spring constant of test example 2 Fi spring was 1.9 kg/
This was carried out under the same conditions as above except that Fi was reduced to mm.

Table 1: Quenching strain of annular parts For comparison, the same table shows a test example using the VC1 conventional method as a comparative example. this house.

Comparison fJ1tl! With the press wench that has been tried in the past, the recess t shown in Figure 1 and the outer diameter of the recess 143B were completely restrained hydraulically with a chiller 3, and the quenched tube was carried out under the same conditions as Test Example 1. , the amount of strain is larger than that of Test Example 1, and the tendency of strain is also reversed. In Comparative Example 2, which is a conventional method, quenching was performed under the same conditions as above without using a cold metal and a spring V*, so the quenching distortion was also the largest.

As is clear from the table above (for one-shot eA).

Compared to the conventional method, the amount of quenching strain in Test Example 1 is approximately 1/1G.

In Test Example 2, it is possible to reduce the temperature by about 173K.

This is a duck for the following reason. That is, in the high frequency applied Mti*, since the concave portion 1b and the convex portion 1m have different masses, a difference in temperature distribution occurs, which becomes a cause of the occurrence of IK distortion in the annular part. The temperature distribution in the annular part 1 is equalized by the cooling device 1bK, which measures the temperature distribution in the annular part 1.
Furthermore, the amount of expansion t due to spring 4#i, thermal stress, and transformation stress.

The reaction force of the spring 40 has the effect of significantly reducing the force. It was. By appropriately selecting the spring constant, it is possible to arbitrarily set the spring constant to 14 even if various conditions such as the size and shape of the object to be heated, or the quenching time and quenching depth are changed.

In addition, in the above embodiment, 6 chillers according to the present invention 3
Although JIS stainless steel 5US304 t- was used, similar effects can be obtained by using other steels, copper, copper alloys, etc. Furthermore, a structure may be adopted in which a coolant such as liquid or gas flows through the chiller 3 to cool the whole 3 itself.

In addition, in the present invention, the reaction force of the spring 40 changes depending on the expansion amount of the annular part 1 of the object to be heated, so that distortion can be reduced. Added characteristics. It is equipped with a pressure adjustment device that changes the pressure depending on the amount of expansion, and a stress buffer mechanism using hydraulic pressure or gas pressure may also be used.

Since the area is 0.11 ha, according to the present invention.

When hardening annular parts with irregularities on the outer surface.

Compared to the conventional hardening method, induction hardening can significantly reduce the distortion of the tube. Therefore, it is also possible to eliminate or reduce the number of man-hours for distortion correction, cutting, etc., which reduces productivity and manufacturing costs. A big effect can be obtained on the surface.

The device is of great practical value because it only needs to be supported by a chiller and energized by a chiller T spring, and has an extremely simple structure, high reliability, and can be provided at low cost.

[Brief explanation of the drawing]

The figure is a cross-sectional view of a low strain induction hardening apparatus for annular parts according to the present invention. 1111111・Annular parts. 1a@...Protrusion. 1bφ/ψ/concavity. 2-axis φ/high frequency coil. 3. Fist/cold money. 4...Spring. 56am @ hold it. 5a - Recess in the grip-holding device.

Claims (2)

[Claims] (1) In an apparatus for induction hardening the inner periphery of an annular part having an outer IRK unevenness, a chiller is provided at a position corresponding to the recess on the outer periphery of the annular part so as to be movable relative to the annular part, and the chiller is A biasing means is provided on the outer periphery, and the cooling metal is biased toward the annular component by the biasing means, so that the annular component can be restrained in the recessed portion of the outer periphery. Induction hardening equipment. (2) In the low-distortion induction hardening apparatus for annular parts according to claim 1, the biasing means marked with # is a spring.