JP2001064729A - Induction hardening device for shaft-shaped work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in the quality of induction hardening, etc., caused by the unevenness of burning by the resplash of a cooling liq. SOLUTION: This is an induction hardening device for a shaft-shaped work in which a high frequency heating coil 100 is moved along a horizontally placed shaft-shaped work W and is provided with a cooling jacket 200 ejecting a cooling liq. L on the part heated by the high frequency heating coil 100 and a gas ejecting mechanism 300 ejecting Air toward the side ejected with the cooling liq. from the side which has not been subjected to induction hardening viewed from the high frequency heating coil 100, and the gas ejecting mechanism 300 is constituted in such a manner that Air is ejected on the whole range in which the cooling liq. L is ejected from the cooling jacket 200.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction hardening device for a shaft-shaped work which relatively moves a shaft-shaped work and a high-frequency heating coil.

[0002]

2. Description of the Related Art For example, an induction hardening apparatus for performing induction hardening on a peripheral surface of a shaft-shaped work, which is a main shaft of a lathe, includes a rotary drive mechanism for rotating the shaft-shaped work horizontally and heating the peripheral surface. A high-frequency heating coil, a cooling jacket that is integrated with the high-frequency heating coil, injects a cooling liquid into a portion heated by the high-frequency heating coil, and the high-frequency heating coil and the cooling jacket are arranged along a shaft-shaped work. And a moving mechanism for moving.

On the other hand, a flange portion is provided on one end side of a main shaft of a lathe which is a shaft-shaped work. The rotation drive mechanism drives the rotation around the axis while holding the flange portion with the chuck of the rotation drive mechanism.
Further, the high-frequency heating coil has a substantially ring-shaped heating conductor portion, and the shaft-like work enters the inside of the heating conductor portion. Furthermore, the cooling jacket is configured by opening a plurality of openings in the heating conductor portion of the high-frequency heating coil, and injects a cooling liquid for cooling the high-frequency heating coil itself toward the peripheral surface of the shaft-shaped work. It is supposed to. There is also a type in which a cooling liquid to be sprayed on the work and a cooling liquid for cooling the high-frequency heating coil itself are provided in different systems. This type is indispensable when the coolant to be sprayed on the workpiece and the coolant to cool the high-frequency heating coil itself are different types.

[0004] The induction hardening apparatus for a shaft-shaped workpiece having such a configuration performs the induction hardening as follows. First, heating is started in a state where the high-frequency heating coil is close to the flange portion of the shaft-shaped work. Then, the high-frequency heating coil is moved toward the tip end of the shaft-shaped work by the moving mechanism.

[0005]

However, the above-described conventional induction hardening apparatus for a shaft-shaped work has the following problems. First, when the cooling liquid is injected from the cooling jacket in a state where the high-frequency heating coil is close to the flange, the cooling liquid collides with the flange and rebounds to the side not yet heated by the high-frequency heating coil and flows out. The outflow of the cooling liquid cools a part to be heated, which leads to deterioration of the quality of the induction hardening.

[0006] Even if the workpiece is a shaft-shaped work having no flange, the chuck performs the same operation as the flange when it is gripped by the chuck, so that the quality of induction hardening is deteriorated.

For this reason, the following induction hardening apparatus for a shaft-shaped work has been invented. In this induction hardening device for a shaft-shaped work, an air injection mechanism for injecting air to the side is provided. In this air injection mechanism, two pipes for injecting air face the peripheral surface of a shaft-shaped work. Therefore, this air injection mechanism pushes the coolant that collides with the flange portion and flows out to the side not yet heated by the high-frequency heating coil back to the flange portion side, that is, the side heated by the high-frequency heating coil. .

However, even in the induction hardening device for a shaft-shaped work provided with the air injection mechanism, the coolant is not completely pushed back to the flange side, and a part of the coolant is not heated yet. Also leaks.

In order to prevent the coolant from rebounding, a method of interposing a waterproof plate having an opening through which the shaft-shaped work W penetrates between the cooling jacket and the high-frequency heating coil may be considered. However, in this case, it is necessary to change the diameter of the opening of the waterproof plate according to the diameter of the shaft-shaped work. In addition, since a gap is inevitably formed between the opening and the shaft-shaped work W, it is difficult to completely prevent the coolant from splashing back.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an induction hardening apparatus for a shaft-shaped work in which the quality of the induction hardening does not deteriorate due to uneven baking caused by rebound of a coolant. It is an object.

[0011]

According to the present invention, there is provided an induction hardening device for a shaft-shaped work, which relatively moves a laid shaft-shaped work and a high-frequency heating coil. A cooling jacket for injecting a cooling liquid into a portion heated by the high-frequency heating coil,
The gas is injected from the side where the induction hardening is not applied to the side where the cooling liquid is injected when viewed from the high frequency heating coil, and the cooling liquid injected from the cooling jacket is applied to the side where the induction hardening is not applied. A gas injection mechanism for preventing the gas from flowing out, wherein the gas injection mechanism is configured to inject gas into the entire range in which the cooling liquid is injected from the cooling jacket.

[0012]

FIG. 1 is a schematic sectional view of an induction hardening device for a shaft-shaped work according to an embodiment of the present invention, and FIG.
FIG. 1 is a schematic perspective view of an integrated high-frequency heating coil, a cooling jacket, and a jacket of a gas injection mechanism used in an induction hardening device for a shaft-shaped work according to an embodiment of the present invention.

First, a shaft-shaped work W subjected to induction hardening by a shaft-shaped work hardening apparatus according to an embodiment of the present invention is used as a main shaft of a lathe, and has a flange portion at one end. W1 is formed.
Then, induction hardening is performed on the peripheral surface of the shaft-shaped work W.

An induction hardening apparatus for a shaft-shaped work according to an embodiment of the present invention is an induction hardening apparatus for a shaft-shaped work that moves a high-frequency heating coil 100 along a laid shaft-shaped work W, High frequency heating coil 1
A cooling jacket 200 for injecting the cooling liquid L into the portion heated at 00, and air Air is injected from a side where the high frequency quenching is not performed to a side where the cooling liquid L is injected as viewed from the high frequency heating coil 100. And cooling jacket 20
And a gas injection mechanism 300 for preventing the cooling liquid L injected from the cooling liquid L from flowing out to the side on which the induction hardening is not performed. It is configured to inject the air Air into the entire range to be injected.

The high-frequency heating coil 100 is substantially the same as the conventional one, and has a heating conductor 110 having a substantially ring shape as shown in FIG.
The shaft-shaped work W enters the inside of the shaft 10.
The high-frequency heating coil 100 includes a cooling jacket 20.
0 is attached. That is, the high-frequency heating coil 10
A plurality of openings 210 are formed in the 0 heating conductor portion 110, and a cooling liquid L for cooling the high-frequency heating coil 100 itself is sprayed from the openings 210 toward the peripheral surface of the shaft-shaped work W. . In particular, the opening 210
Is directed to the opposite side of the direction in which the high-frequency heating coil 100 moves in order to directly inject the cooling liquid L into the portion where the high-frequency heating has been completed. As described in the section of the related art, the cooling liquid to be sprayed on the work W and the high-frequency heating coil 1
The cooling liquid for cooling the cooling water itself may be provided in a separate system.

The high-frequency heating coil 100 is connected to a high-frequency power source (not shown) by a pair of power supply conductors 120.

The gas injection mechanism 300 includes a substantially ring-shaped jacket 310 having a plurality of injection holes 311.
And a pump 320 for pumping air Air to the jacket 310. The jacket 310 is attached to the high-frequency heating coil 100 via an insulating plate 250 made of, for example, Teflon. In addition, the jacket 310 is attached to the traveling direction side of the high-frequency heating coil 100 when viewed from the high-frequency heating coil 100. Further, the injection holes 311 of the jacket 310 are provided at positions where the air Air is injected over the entire range in which the cooling liquid L is injected from the cooling jacket 200.

Therefore, the gas injection mechanism 300 is viewed from the high-frequency heating coil 100 toward the side where the cooling liquid L is injected from the side where the induction hardening is not performed, that is, the side where the flange portion W1 is not formed. And the cooling liquid L injected from the cooling jacket 200.
Is prevented from flowing to the side on which the induction hardening is not performed, that is, the side on which the flange portion W1 is not formed.

The jacket 310 of the gas injection mechanism 300 is made of a non-magnetic material having heat resistance and insulating properties, such as epoxy resin or ceramics, so as not to be affected by the high-frequency heating coil 100. .

As described above, the integrated high-frequency heating coil 100, cooling jacket 200 and gas injection mechanism 30
The moving mechanism 400 moves the jacket 310 along the shaft-shaped workpiece W. The moving mechanism 400 includes, for example, a feed screw 410 and a slider 420 that is slid by the feed screw 410.
And a motor 430 for driving the feed screw 410 to rotate. The high-frequency heating coil 100, the cooling jacket 200, and the jacket 310 of the gas injection mechanism 300 are attached to the slider 420, and the high-frequency heating coil 100 and the like are moved along the shaft-shaped workpiece W by rotating the feed screw 410. It moves.

On the other hand, the horizontal shaft-shaped work W is driven to rotate by the rotation drive mechanism 500. The rotation drive mechanism 500 includes a chuck 510 that holds one end of the shaft-shaped work W, a support center 520 that supports the other end of the shaft-shaped work W, a motor 530 that drives the chuck 510 to rotate, and a horizontal shaft. And a support roller (not shown) for supporting the workpiece W from below. Therefore, the shaft-shaped work W is
Is driven to rotate about the axis W2. The chuck 510 grips the end of the shaft-shaped work W where the flange portion W1 is formed, that is, the base end side.

Next, the induction hardening of the shaft-like work W by the induction hardening device for a shaft-like work configured as described above will be described. First, the shaft-shaped work W is supported by the rotation drive mechanism 500. At this time, the shaft-shaped work W passes through the high-frequency heating coil 100 in which the cooling jacket 200 is integrated and the jacket 310 of the gas injection mechanism 300.

The high-frequency heating coil 100 is positioned on the flange W1 side of the shaft-shaped work W. That is, induction hardening is started from the side close to the flange portion W1.

A high-frequency heating coil 1 from a high-frequency power source (not shown)
00 is supplied with a high-frequency current to heat the peripheral surface of the portion near the flange portion W1. That is, stop heating is performed without moving the high-frequency heating coil 100 along the shaft-shaped work W at first. After performing the stop heating for a predetermined time, the movement of the high-frequency heating coil 100 by the movement mechanism 400 is started. Then, after the high-frequency heating coil 100 moves a predetermined distance, the injection of the cooling liquid L from the cooling jacket 200 and the injection of the air Air from the jacket 310 of the gas injection mechanism 300 are simultaneously started.

After the coolant L injected from the cooling jacket 200 passes through the heated portion, the coolant L
, It is likely to be bounced back to the high-frequency heating coil 100 side. However, at the same time as the injection of the cooling liquid L, the air Air is injected from the side where the induction hardening is not performed toward the side where the cooling liquid L is injected, as viewed from the high-frequency heating coil 100, so that the cooling that tends to bounce off The liquid L will be pushed back. In particular, since the jacket 310 that constitutes the gas injection mechanism 300 injects the air Air into the entire range in which the cooling liquid L is injected from the cooling jacket 200, it is more reliable than the conventional case of two pipes. The cooling liquid L can be pushed back to the flange portion W1 side. After the air Air is injected from the gas injection mechanism 300, the air Air is continuously injected from the gas injection mechanism 300 while the high-frequency heating coil 100 is moving.
The rebound of the cooling liquid L does not occur, and the problem of the quality of the shaft-shaped work W caused by this does not occur.

When the movement of the high-frequency heating coil 100 is completed, that is, the induction hardening is completed, the rotation driving mechanism 50
The support of the shaft-shaped work W by the shaft work 0 is released, and the shaft-shaped work W, which has been subjected to the induction hardening, is replaced with a new shaft-shaped work W by an unillustrated transport / infeed mechanism.

For example, in the case of a shaft-shaped work W having a diameter of 75 mm, the heating conductor 11 of the high-frequency heating coil 100
The inner diameter of 0 is 85 mm and the shaft-shaped workpiece W is 2
When rotated at 0 rpm, the cooling liquid L is set to 30 liter / min, and the moving speed of the high-frequency heating coil 100 is set to 4 milliseconds, the cooling liquid L injected at a position 5 mm away from the flange portion W1 is gaseous. Air Air from the injection mechanism 300
, The rebound could not be prevented because the momentum of the cooling liquid L was stronger. However, the flange W
In the case of the coolant L injected at a position 10 mm away from 1 mm, it could be confirmed that no rebound was generated by the flange portion W1.

In the above-described embodiment, the gas injection mechanism 3
The gas injected from 00 is air Air, but may be an inert gas such as argon. If the inert gas is injected in this manner, non-oxidative quenching is also possible. However, when performing non-oxidation quenching, it is necessary to use a coolant that does not contain oxygen.

Further, although the main shaft of the lathe provided with the flange portion W1 at one end has been described as the shaft-shaped work W, the shaft-shaped work W may not have the flange portion W1. That is, even if the flange portion W1 is not provided, if the chuck 510 is held by the chuck 510 of the rotary drive mechanism 500, the chuck 510 performs the same operation as the flange portion W1, and the same problem occurs.

Further, in the above-described embodiment, the high-frequency heating coil 100 and the like are moved along the shaft-shaped work W. On the contrary, the high-frequency heating coil 100 and the like are fixed and the shaft-shaped work W is moved. Alternatively, the high-frequency heating coil 100 and the shaft-like workpiece W may be moved simultaneously.

In the above-described embodiment, the cooling jacket 200 is attached to the high-frequency heating coil 100.
Of course, both may be separate bodies.

[0032]

The induction hardening apparatus for a shaft-shaped work according to the present invention is an induction hardening apparatus for a shaft-shaped work in which a horizontally laid shaft-shaped work and a high-frequency heating coil are relatively moved. A cooling jacket that injects the cooling liquid into the heated portion, and a gas that is injected from the side where the cooling liquid is not injected to the side where the cooling liquid is injected from the side where the induction hardening is not performed as viewed from the high frequency heating coil, is injected from the cooling jacket. A gas injection mechanism for preventing the cooling liquid from flowing out to the side not subjected to induction quenching, wherein the gas injection mechanism injects gas to the entire range where the cooling liquid is injected from the cooling jacket. It is configured to be.

Therefore, when induction hardening is performed by the induction hardening device for the shaft-shaped work, there is no rebound of the cooling liquid on the side on which the induction hardening has not yet been performed. As a result, the quality of induction hardening does not deteriorate.

If the gas injected from the gas injection mechanism is air, the quality of induction hardening can be improved while keeping running costs low.

Further, when the gas injected from the gas injection mechanism is an inert gas, it can be applied to non-oxidative quenching.

On the other hand, in the induction hardening device for a shaft-shaped work, the high-frequency heating coil starts moving after performing stop heating for a predetermined time, and injects cooling liquid from the cooling jacket only after moving for a predetermined distance. Then
Even at the end where it is difficult to completely prevent the quenching liquid from rebounding, it is possible to solve the problem of quality deterioration due to the quenching liquid's rebounding.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an induction hardening device for a shaft-shaped work according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of an integrated high-frequency heating coil, a cooling jacket, and a jacket of a gas injection mechanism used in an induction hardening device for a shaft-shaped work according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 high-frequency heating coil 200 cooling jacket 300 gas injection mechanism W shaft-shaped work W1 flange

Claims (4)

[Claims] 1. A high-frequency quenching device for a shaft-shaped work that relatively moves a laid-down shaft-shaped work and a high-frequency heating coil, a cooling jacket that injects a cooling liquid to a portion heated by the high-frequency heating coil, The gas is injected from the side where the induction hardening is not applied to the side where the cooling liquid is injected when viewed from the high frequency heating coil, and the cooling liquid injected from the cooling jacket is applied to the side where the induction hardening is not applied. A gas injection mechanism for preventing the gas from flowing out, wherein the gas injection mechanism injects gas into the entire range in which the cooling liquid is injected from the cooling jacket. apparatus. 2. The induction hardening device for a shaft-like workpiece according to claim 1, wherein the gas injected from the gas injection mechanism is air. 3. The induction hardening device for a shaft-shaped workpiece according to claim 1, wherein the gas injected from the gas injection mechanism is an inert gas. 4. The induction hardening device for a shaft-shaped work according to claim 1, 2 or 3, wherein the high-frequency heating coil starts moving after performing stop heating for a predetermined time and starts moving after a predetermined distance. An induction hardening device for a shaft-shaped work, characterized by injecting a cooling liquid from the inside.