JPH07224327A - High-frequency hardening method and high-frequency hardening device of nearly cylindrical work - Google Patents

Abstract

PURPOSE:To provide a method for high-frequency hardening of the outer peripheral surface and inner peripheral surface of nearly a cylindrical work having plural recesses. CONSTITUTION:A spiral first heating coil 10 is disposed to enclose the outer peripheral surface of a sleeve 100 and to face the peripheral surface in proximity thereto and a spiral second heating coil 20 is inserted into the inner peripheral surface so as to face the inner peripheral surface in proximity thereto to heat the sleeve which is a work. A large high-frequency current of a relatively low frequency is supplied to this first heating coil 10 in a relatively short period of time to heat the outer peripheral surface. An ordinary high-frequency current of a relatively high frequency is supplied to the second heating coil 20 to heat the inner peripheral surface. Rotation of the sleeve 100 is thereafter slowed down or the rotation is stopped and the sleeve 100 is immersed into a quenching liquid L and while the state of rotation of the sleeve 100 is continued, the quenching liquid L is injected simultaneously to the outer peripheral surface and inner peripheral surface respectively of the sleeve 100 immersed into the quenching liquid L.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction hardening method and an induction hardening apparatus for a substantially cylindrical work having an inner peripheral surface, an outer peripheral surface and a plurality of circumferentially formed recesses on the outer peripheral surface. .

[0002]

2. Description of the Related Art First, a work shown in FIGS. 6 and 7 taken as an example of a substantially cylindrical work will be described.
As shown in FIGS. 6 and 7, the surface of the sleeve 100, which is a substantially cylindrical work, has an outer peripheral surface 101 and an inner peripheral surface 10.
6, upper surface 108, and lower surface 109. By forming three recesses 104 at equal intervals on the outer peripheral surface 101, three protrusions 105 are formed at equal intervals. Surface 102 of recess 104 and surface 10 of projection 105
An outer peripheral surface 101 of the work is constituted by 3 and 3.
In addition, 110 is an axial center line of the sleeve 100.

Hardened layers 111 and 112 are formed on the outer peripheral surface 101 and the inner peripheral surface 106 of the sleeve 100, respectively.
Conventionally, carburizing and quenching has been exclusively used to form the.

[0004]

This carburizing and quenching is carried out with a large number of works housed in a large furnace.
Therefore, since the installation area of the furnace is large, the site of the factory is widened and the construction cost is also increased. Next, before quenching, it is necessary to carry a large number of workpieces into the furnace.
After quenching, it is necessary to carry out the work. Although these loading and unloading operations cannot be avoided by carburizing and quenching in which work hardening is performed in batch processing, it is extremely troublesome. After all, carburizing and quenching suffers from the drawback that the quenching cost of a large number of workpieces is mechanically and continuously carried out, and finally the purpose of further reducing the quenching cost cannot be achieved.

The present invention was devised in view of the above circumstances, and has a substantially cylindrical shape having a plurality of recesses circumferentially formed on the inner peripheral surface, the outer peripheral surface, and the outer peripheral surface of a substantially cylindrical work. In order to enable simultaneous quenching of the outer and inner peripheral surfaces of a cylindrical work as a continuous mechanical work, such outer and inner peripheral surfaces of a cylindrical work are quenched by high frequency induction. It is an object of the present invention to provide a method and an induction hardening apparatus that can realize the method.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 has a substantially cylindrical shape having an inner peripheral surface, an outer peripheral surface, and a plurality of recesses circumferentially formed on the outer peripheral surface. Induction hardening method for a work piece, comprising: arranging a first high-frequency heating coil in a spiral shape so as to surround the outer peripheral surface and closely face the outer peripheral surface, and a spiral shape so as to closely face and face the inner peripheral surface. Second step of inserting the second high-frequency heating coil of the above into the inner peripheral surface, and second step of preheating the work after the first step
After the step and the second step, while rotating the workpiece around the axis of the workpiece, a high-frequency current having a relatively low frequency is supplied to the first high-frequency heating coil for a short time to heat the outer peripheral surface. 2 A high-frequency current of a relatively high frequency and a normal magnitude is applied to the high-frequency heating coil to heat the inner peripheral surface, and the outer peripheral surface is heated by the first high-frequency heating coil and the inner peripheral surface is heated by the second high-frequency heating coil. The third step of simultaneously terminating the heating of the workpiece and after the third step, the rotation of the work is slowed or the rotation of the work is stopped, and
The fourth step of immersing the workpiece in the quenching liquid, and the outer peripheral surface and the inner circumference of the workpiece immersed in the quenching fluid after the fourth step, while continuing the state of rotation of the workpiece in the fourth step. And a fifth step of spraying the quenching liquid onto the surfaces simultaneously.

The invention according to claim 2 has a substantially cylindrical shape in which an inner peripheral surface, an outer peripheral surface, and a plurality of recesses formed in the outer peripheral surface in the circumferential direction are provided, and an axial center line is arranged substantially vertically. A high-frequency induction hardening apparatus for a work, comprising: a spiral first high-frequency heating coil which is arranged close to and faces the outer peripheral surface so as to surround the outer peripheral surface of the work and heats the outer peripheral surface of the work; A spiral second high-frequency heating coil which is inserted into the inner peripheral surface so as to approach and face the inner surface and heats the inner peripheral surface of the work; and a quenching liquid is accommodated below the first and second high-frequency heating coils. A quenching liquid tank disposed in the quenching liquid, and an annular shape that is disposed in the quenching liquid so as to surround the outer peripheral surface of the work immersed in the quenching liquid and injects the quenching liquid onto the outer peripheral surface of the work. The first jacket and the inner peripheral surface of the work immersed in the quenching liquid are opposed to each other. A cylindrical second jacket that is disposed in the quenching liquid and injects the quenching liquid onto the inner peripheral surface of the work; and a work that holds the work, raises and lowers it, and rotates about the axis of the work. And a supporting device.

According to a third aspect of the present invention, in the second aspect of the present invention, the work supporting device holds the lower end portion of the work, and the bottom of the quenching liquid tank is movable up and down in the direction of the axis. , A substantially cylindrical shape that is rotatably centered on the axis and liquid-tightly penetrates, and is arranged so as to surround a second jacket quenching liquid supply pipe that extends downward at the lower end of the second jacket. The first work support member of the
A horizontal annular gear provided on the outer peripheral surface of the work supporting member,
A vertical spline with which the gear meshes, a rotation source of the spline, and a substantially cylindrical shape slidably mounted on the outer peripheral surface of the second jacket quenching liquid supply pipe in the axial direction of the workpiece. A second work support member and a first work support member rotatably coupled to the second work support member, the first work support member being provided between the inner work surface of the first work support member and the outer work surface of the second work support member. And a means for raising and lowering the second work supporting member.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an induction hardening apparatus capable of implementing the method of the present invention will be described below with reference to the drawings.
1 to 7 are drawings for explaining the present embodiment,
1 is a vertical sectional front view, FIG. 2 is a plan view, FIG. 3 is a partial perspective view, FIG. 4 is a time chart for explaining the operation, FIG. 5 is a cross-sectional view of a work, and FIG. 6 is a plan view of the work. 7A and 7B are cross-sectional views taken along the lines AA and BB of FIG. 6, respectively. As the work, the sleeve 100 shown in FIGS. 6 and 7 which has already been described in the prior art is adopted.
A case where the outer peripheral surface 101 and the inner peripheral surface 106 of the sleeve 100 are induction-hardened will be described.

As shown in FIG. 1, in the induction hardening apparatus of the present embodiment, the sleeve 100 is placed in the induction hardening apparatus to stand by, or the waiting position A as a position for carrying out after hardening, There are three positions, a heating position B for heating the sleeve 100 and a cooling position C for immersing and heating the heated sleeve 100 in a quenching liquid.

As shown in FIGS. 1 and 2, the standby position A
At the heating position B located above, the spiral first high-frequency heating coil 10 (which surrounds the outer peripheral surface 101 of the sleeve 100 and is disposed so as to approach and face the outer peripheral surface 101 to heat the outer peripheral surface 101 ( Hereinafter, the high frequency heating coil will also be referred to simply as the heating coil) and the inner peripheral surface 10 of the sleeve 100.
6 and a second spiral heating coil 20 which is arranged so as to approach and face the inner peripheral surface 106 and heats the inner peripheral surface 106.
Both the first and second heating coils 10 and 20 are supported by a support member (not shown) from a frame body (not shown) of the induction hardening apparatus. The first and second heating coils 10 and 20 have a common axis 110.

The first heating coil 10 comprises a heating conductor 11 wound in a spiral shape, and a pair of linear lead conductors 12 connected to both ends of the heating conductor 11, and the lead conductor 12 is It is connected to a high frequency power source 19 having a relatively low frequency, for example, 20 kHz.

The second heating coil 20 includes a heating conductor 21 wound in a spiral shape and a pair of linear lead conductors 22 connected to both ends of the heating conductor 21, and the lead conductor 22 is It is connected to a high frequency power source 29 having a relatively high frequency, for example 400 kHz. The hollow portions of the heating conductors 11 and 22 are passages for the cooling liquid of the heating conductors 11 and 22, respectively.

At the cooling position C located below the standby position A, there is provided a quenching liquid tank 32 which contains the quenching liquid L and has an open upper surface. An annular first jacket 30 is provided in the quenching liquid L. This first jacket 3
No. 0 is arranged so as to surround the outer peripheral surface 101 of the sleeve 100, which is cooled by being immersed in the quenching liquid L such that the shaft core 110 is vertical, and a large number of quenching liquid jets on the inner peripheral surface. The hole 31 is opened.

In the quenching liquid L, a cylindrical second jacket 40 is vertically provided. The second jacket 40 is disposed so as to face the inner peripheral surface 106 of the sleeve 100 immersed in the quenching liquid L, and a large number of quenching liquid injection holes 41 are formed on the outer peripheral surface. Second jacket 4
A second jacket quenching liquid supply pipe 42 extending downward is fixed to the lower end of 0, and the lower portion of this pipe 42 is
It is fixed to a mounting surface 49 of the induction hardening device via a table 45. Reference numeral 43 is a supply path for the quenching liquid L supplied to the quenching liquid supply port 44 to the second jacket 40.

A work supporting device 2 that supports the sleeve 100, raises and lowers it, and rotates it about an axis 110.
00 holds the lower end portion of the sleeve 100 and allows the bottom of the quenching liquid tank 32 to move up and down in the direction of the axis 110.
A substantially cylindrical first work supporting member 50A which is rotatably centered on the shaft core 110 and penetrates in a liquid-tight manner so as to surround the second jacket quenching liquid supply pipe 42.
As the rotating means 60 of the first work supporting member 50A, a horizontal annular gear 63 provided on the outer peripheral surface of the first work supporting member 50A, a vertical spline 62 with which the gear 63 meshes, and the spline. And a motor 61 for rotating 62.

Further, the work supporting device 200 is the second
The shaft core wire 110 is provided on the outer peripheral surface of the jacket quenching liquid supply pipe 42.
Is provided between the inner peripheral surface of the first work supporting member 50A and the outer peripheral surface of the second work supporting member 50B. A pair of bearings 56 and 5 rotatably coupling the one work supporting member 50A to the second work supporting member 50B.
7 and an elevating means 70 for elevating the second work supporting member 50B.

The work supporting device 200 will be described in more detail. The first work supporting member 50A is an annular sleeve 51 mounted around the opening at the bottom of the quenching liquid tank 32.
A cylindrical member 52 slidably, rotatably and liquid-tightly attached to the inner peripheral surface of the sleeve 51 in the direction of the axis 110, and a disc member 54 attached to the upper end of the cylindrical member 52. , A work support member 55 made of, for example, ceramic, which is provided at three equally spaced locations around the upper surface of the disk member 54.
Is equipped with.

As shown in FIG. 3, the work support member 55.
Has a stepped surface 55b at its tip to form a protrusion 55a. The surface of the protrusion 55a on the step surface 55b side is brought into contact with the lower portion of the recess 104 of the sleeve 100, and the step surface 55b is brought into contact with the lower surface 109 of the sleeve 100, so that the work supporting member 55 allows the sleeve 1 to move.
Holds 00.

Lifting means 70 for the second work supporting member 50B
Is a crank-shaped connecting member 71 having one end fixed to the lower end of the second work supporting member 50B, and a rod 72 connected to the other end of the connecting member 71 and arranged substantially vertically.
And a cylinder 73 whose base end is attached to the bottom of the quenching liquid tank 32 by moving the rod 72 forward and backward.

58a and 58b are respectively
It is a gasket that makes the space between the disc member 54 and the second jacket quenching liquid supply pipe 42 and between the first work support member 50A and the sleeve 51 liquid-tight. 58c and 5
8d, between the disk member 54 and the cylindrical member 52, and between the sleeve 51 and the quenching liquid tank 32, respectively.
It is an O-ring that is liquid tight. Also, 58e and 58f
Are snap rings for fixing the bearings 56 and 57, respectively.

Next, a system for supplying the quenching liquid L to the first and second jackets 30 and 40 will be described. The quenching liquid supply pump 83 has a suction side which is connected to the quenching liquid tank 32 through a pipe 84.
It communicates with the bottom of the. The discharge side of the quenching liquid supply pump 83 is connected to the inlets of the solenoid valves 81 and 82 via a pipe 85. The outlet of the solenoid valve 81 is connected to the first jacket 30 via a pipe 86, and the solenoid valve 82
Is connected to the supply port 44 of the second jacket quenching liquid supply pipe 42 via the pipe 87.

The operation of the induction hardening apparatus of this embodiment will be described below. The quenching liquid supply pump 83 is started in advance with the solenoid valves 81 and 82 closed. The sleeve 100 is arranged at the standby position A by an appropriate manipulator (not shown) so that the axis 110 of the sleeve 100 is vertical.

A description will be given below with reference to FIG. First, the points P1 to P2 will be described. Work support device 200
The cylinder 73 is operated to move the rod 72 backward to raise the work supporting member 55, and after the work supporting member 55 supports the lower end portion of the sleeve 100, the work supporting member 55 is further raised to raise the outer circumference of the sleeve 100. The sleeve 100 is arranged so that the surface 101 faces the inside of the first heating coil 10 and the inner peripheral surface 106 of the sleeve 100 surrounds the second heating coil 20.

After that, when the motor 61 is started, the first work supporting member 5 is moved through the spline 62 and the gear 63.
0A rotates around the axis 110. That is, the sleeve 100 rotates. Then, a high-frequency current smaller than that when main heating is performed from the high-frequency power source 19 is applied to the first heating coil 10 so that the temperature of the sleeve 100 is 400 ° C.
Preheat to 450 degrees. After this, the high frequency power source 19
To the first heating coil 10 for a short time with a large current of 20 kHz, and from the high frequency power source 29 to a current of 400 kHz for the second heating coil 20, respectively,
The main heating of 1 and the inner peripheral surface 106 is finished at the same time. However, the shape of the work 100 and the required hardened layers 111, 1
Depending on the specifications of No. 12, the energization time for the first heating coil 10 may be the same as the energization time for the second heating coil 20, and the energization time for the first heating coil 10 may be the same for the second heating coil 20. It may be longer than the energization time. In any case, the outer peripheral surface 101 is heated by the first heating coil 10 and the inner peripheral surface 10 by the second heating coil 20.
The heating of 6 is completed at the same time.

Next, the points P2 to P3 will be described.
When the main heating is completed, the cylinder 73 is operated and the rod 72 is advanced so that the sleeve 100 passes through the standby position A, is further lowered, and is immersed in the quenching liquid L at the cooling position C. While the sleeve 100 is being lowered, the motor 61 is controlled to slow down the rotation of the sleeve 100 (in some cases, the rotation of the sleeve 100 is stopped).

Next, points P3 to P4 will be described. When the solenoid valves 81 and 82 are opened after the sleeve 100 is completely immersed in the quenching liquid L, the quenching liquid L from the first and second jackets 30 and 40 is the outer peripheral surface 101 and the inner periphery of the sleeve 100, respectively. The outer peripheral surface 101 is jetted to the surface 106,
The inner peripheral surface 106 is cooled.

When the cooling of the outer peripheral surface 101 and the inner peripheral surface 106 is completed, as shown in FIG. 5, the outer peripheral surface 101 is slightly deeper in the outer peripheral surface 103 of the convex portion 105, but
Outer peripheral surface 102 of concave portion 104 and outer peripheral surface 1 of convex portion 105
A hardened layer 111 having a substantially uniform depth is formed through 03 and contour hardening is performed. A hardened layer 112 having a uniform depth is also formed on the inner peripheral surface 106.

[0029]

As described above, according to the present invention, the induction hardening of a substantially cylindrical work having a plurality of recesses formed in the inner peripheral surface, the outer peripheral surface, and the outer peripheral surface in the circumferential direction is performed. After arranging the spiral first high-frequency heating coil so as to surround the outer peripheral surface of the workpiece and closely face the outer peripheral surface, and insert the spiral second high-frequency heating coil so as to closely face the inner peripheral surface of the workpiece, After preheating the work, while rotating the work about the axis of the work as a center, a high-frequency current having a relatively low frequency is supplied to the first high-frequency heating coil for a short period of time to heat the outer peripheral surface and the second high-frequency wave. The inner peripheral surface is heated by supplying a high-frequency current of a relatively high frequency of a normal magnitude to the heating coil, and then the rotation of the work is slowed or the rotation of the work is stopped and State While keeping the row, by immersing the workpiece in a tempering liquid inlet to inject simultaneously each sintered liquid inlet to the outer and inner peripheral surfaces of immersed workpiece during tempering the liquid inlet.

Therefore, according to the present invention, a desired hardened layer can be formed on the outer peripheral surface and the inner peripheral surface of the work by induction hardening. Therefore, by quenching the outer peripheral surface and the inner peripheral surface of a substantially cylindrical work by using the induction hardening method and apparatus of the present invention, a large installation area as in the conventional case is required, or mechanical continuity is required. It is possible to overcome the drawbacks of carburizing and quenching that cannot be quenched.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an example of an induction hardening apparatus capable of realizing the method of the present invention.

FIG. 2 is a plan view of the induction hardening apparatus shown in FIG.

FIG. 3 is a perspective view of a part of the induction hardening apparatus shown in FIG.

FIG. 4 is a time chart for explaining the operation of the induction hardening apparatus shown in FIG.

FIG. 5 is a cross-sectional view of a sleeve that is a work.

FIG. 6 is a plan view of a sleeve that is a work.

7A and 7B are cross-sectional views taken along the lines AA and BB of FIG. 6, respectively.

[Explanation of symbols]

 10 1st heating coil 20 2nd heating coil 30 1st jacket 40 2nd jacket 32 Quenching liquid tank 42 1st jacket quenching liquid supply pipe 50A 1st work supporting member 50B 2nd work supporting member 56,57 Bearing 60 rotation Means 61 Motor 62 Spline 63 Gear 70 Elevating means 71 Member 72 Rod 73 Cylinder 100 Sleeve 101 Outer peripheral surface 104 Recess 106 Inner peripheral surface 110 Shaft core wire 200 Work support device

Claims (3)

[Claims] 1. An induction hardening method for a substantially cylindrical work having an inner peripheral surface, an outer peripheral surface, and a plurality of recesses formed in the outer peripheral surface in a circumferential direction, wherein the outer peripheral surface is surrounded by an outer peripheral surface. A first step of arranging a spiral first high-frequency heating coil so as to closely face and face, and inserting a second spiral high-frequency heating coil so as to closely face and face the inner circumferential surface; After the first step, a second step of preheating the work, and after the second step, a large high-frequency current of a relatively low frequency is applied to the first high-frequency heating coil while rotating the work around the axis of the work. While heating the outer peripheral surface by energizing for a short time, the inner peripheral surface is heated by supplying a high frequency current having a relatively high frequency and a normal magnitude to the second high frequency heating coil.
In addition, the heating of the outer peripheral surface by the first high-frequency heating coil and the second
The third step of simultaneously ending the heating of the inner peripheral surface by the high frequency heating coil, and after the third step, the rotation of the work is slowed or the rotation of the work is stopped and the work is immersed in the quenching liquid. After the fourth step and after the fourth step, the quenching liquid is simultaneously applied to the outer peripheral surface and the inner peripheral surface of the workpiece immersed in the quenching liquid while the rotation state of the work in the fourth step is continued. A fifth step of spraying, and an induction hardening method for a substantially cylindrical work. 2. An induction hardening apparatus for a substantially cylindrical work, comprising an inner peripheral surface, an outer peripheral surface, and a plurality of recesses formed in the outer peripheral surface in the circumferential direction, and an axial core line arranged substantially vertically. A spiral first member that is disposed close to and faces the outer peripheral surface of the work so as to surround the outer peripheral surface of the work and heats the outer peripheral surface of the work.
A high-frequency heating coil, a second spiral high-frequency heating coil which is inserted into the inner peripheral surface so as to closely approach and face the inner peripheral surface of the work, and heats the inner peripheral surface of the work; 1
And a quenching liquid tank arranged below the second high-frequency heating coil, and a quenching liquid tank disposed in the quenching liquid so as to surround the outer circumferential surface of the work immersed in the quenching liquid. An annular first jacket for injecting the quenching liquid, and a quenching liquid that is disposed in the quenching liquid so as to face the inner circumferential surface of the workpiece immersed in the quenching liquid Induction hardening of a substantially cylindrical work, comprising a cylindrical second jacket for injecting the work, and a work support device for holding the work, raising and lowering the work, and rotating the work about an axis of the work. apparatus. 3. A work supporting device holds a lower end portion of a work, is capable of moving up and down the bottom of the quenching liquid tank in the direction of the shaft core line, is rotatable around the shaft core line, and is liquid-tight. A substantially cylindrical first work supporting member that is provided so as to surround a second jacket quenching liquid supply pipe that extends downward through the lower end of the second jacket, and the first work supporting member. A horizontal annular gear provided on the outer peripheral surface of the workpiece, a vertical spline with which the gear meshes, a rotation source of the spline, and a shaft core wire of the work on the outer peripheral surface of the second jacket quenching liquid supply pipe. A substantially cylindrical second work support member slidably mounted in the direction, and a first work support member
A bearing provided between the inner peripheral surface of the work supporting member and the outer peripheral surface of the second work supporting member to rotatably connect the first work supporting member to the second work supporting member, and a second work supporting member. The induction hardening apparatus for a substantially cylindrical work according to claim 2, further comprising: