JPH09241729A - Method for hardening inner surface and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely control the strain of a work, in the case of shiftingly hardening the inner surface of a groove in the work. SOLUTION: The inside surfaces 13, 13 of the groove 12 are shiftingly hardened by shifting an induction heating coil 20 and a cooling liquid injecting jacket 30 in the inner part of the recessed groove 12 under condition of directing the surface 11 forming the groove 12 of the work 10 downward. The cooling liquid injected onto the inside surfaces 13, 13 of the groove 12 from the cooling liquid injecting jacket 30 is discharged without staying in the groove 12 and the inner bottom surface of the groove 12 is preheated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner surface quenching method and apparatus for moving and quenching the inner surface of a groove of a work such as a linear motion guide device by induction heating.

[0002]

2. Description of the Related Art A linear motion guide device is an elongated member having grooves formed over its entire length in the longitudinal direction of its surface, and is usually used by quenching the inner surfaces on both sides of the groove. As a method for quenching the inner surface of the groove of the work in which such a groove is formed, there are carburizing and induction hardening.

In induction hardening, as shown in FIG. 4, the surface 11 of the work 10 on which the groove 12 is formed faces upward, and in this state, the inside of the groove 12 is covered by the induction heating coil 20 and the cooling liquid injection jacket 30. It is done by moving. The high frequency heating coil 20 causes the inner surfaces 13, 13 on both sides of the groove 12 to be induction-heated in the longitudinal direction by the movement thereof. The cooling liquid injection jacket 30 is connected to the rear side of the high-frequency heating coil 20 in the moving direction, and the cooling liquid supplied to the inside of the cooling liquid injection jacket 30 is supplied to the nozzle holes 3 on both sides.
The inner side surfaces 13 and 13 of the groove 12 which are jetted out from 1 and heated by the high frequency heating coil 20 are rapidly cooled.

In the case of a linear motion guiding device, quenching is usually applied only to the inner side surfaces 13 on both sides of the groove 12, but depending on the type of work, the inner bottom surface 14 of the groove 12 is also quenched. There are also things.

[0005]

In quenching the inner surface of the groove of such a work, there is a big problem that the work is distorted by the quenching. Specifically, the entire work is often curved in an arc shape so that the surface side of the work in which the groove is formed is recessed.

The present invention was devised in view of the above circumstances, and effectively and easily avoids the retention of the cooling liquid inside the groove to prevent the distortion of the work due to the moving and quenching of the inner surface of the groove. An object of the present invention is to provide an inner surface quenching method and apparatus that can be reduced.

[0007]

The inner surface quenching method according to the present invention continuously heats the inner surface of a groove by a high frequency heating coil that relatively moves inside the groove formed on the surface of the work, and also the high frequency heating coil. A method for quenching the inner surface of a groove, in which the heating surface of the groove is rapidly cooled by a cooling liquid injection jacket that relatively moves inside the groove, in which the surface of the work on which the groove is formed faces downward, The high-frequency heating coil and the cooling liquid injection jacket move relative to each other inside.

When the high-frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, if the surface of the work on which the groove is formed faces downward, the cooling liquid jetted from the cooling liquid jetting jacket will be Since the bottom surface does not accumulate inside and is not rapidly cooled, the preheating effect of the high frequency heating coil reduces the distortion of the work due to quenching.

When the high-frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, the second cooling liquid relatively moves on the back surface of the workpiece facing upward in synchronization with the coil and the cooling liquid jetting jacket. By supplementarily cooling the back surface of the work by the jet jacket, the heat history on the back surface side of the work is intentionally controlled. By using the second high-frequency heating coil instead of the second coolant injection jacket, the heat history on the back surface side of the work is intentionally controlled. By properly using these depending on the shape of the work and the hardening pattern, the distortion of the work due to hardening can be freely controlled.

An inner surface quenching apparatus according to the present invention is an inner surface quenching apparatus for quenching an inner surface of a groove formed on a surface of a work, wherein the surface of the work on which the groove is formed faces downward. The work support part that supports the work in a state, a high frequency heating coil that relatively moves inside the groove of the work, and a cooling liquid jetting jacket that relatively moves inside the groove following the high frequency heating coil are provided.

Further, when the high frequency heating coil and the cooling liquid jetting jacket relatively move, the high frequency heating coil and the cooling liquid jetting jacket relatively move in synchronization with the high frequency heating coil and the cooling liquid jetting jacket on the upper surface of the backside of the work. Has a second cooling liquid jet jacket for auxiliary cooling.

Further, when the high-frequency heating coil and the cooling liquid jetting jacket relatively move, they relatively move in synchronization with the high-frequency heating coil and the cooling liquid jetting jacket on the upper surface of the backside of the work, and the backside of the work. Has a second high-frequency heating coil for auxiliary heating.

The front and back surfaces of the work in this specification do not necessarily mean the front and back surfaces of the product. In the present invention, the surface on which the groove is formed is called the front surface, and the surface on the opposite side is called the back surface. Further, the relative movement of the high frequency heating coil and the cooling liquid jetting jacket means that the work may be moved instead of moving them.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view of an inner surface quenching method and apparatus according to a first embodiment of the present invention, and FIG. 2 is a schematic description of an inner surface quenching method and apparatus according to a second embodiment of the present invention. 3 and 4 are schematic explanatory views of an inner surface quenching method and apparatus according to a third embodiment of the present invention.

The inner surface quenching method according to the first embodiment of the present invention uses the high-frequency heating coil 20 that relatively moves inside the groove 12 formed in the surface 11 of the work 10 to form the groove 12.
A method for quenching the inner surface of the groove 12 in which the heating surface of the groove 12 is rapidly cooled by the cooling liquid jetting jacket 30 that continuously heats the inner surface of the groove 12 and that relatively moves inside the groove 12 following the high-frequency heating coil 20. The high frequency heating coil 20 and the cooling liquid jetting jacket 30 relatively move inside the groove 12 with the surface 11 of the workpiece 10 on which the 12 is formed facing downward.

The work 10 is a surface 1 of a bar having a rectangular cross section.
1 is a linear motion guide device, for example, in which a groove 12 having a substantially square cross section is formed over the entire length. Quenching is performed on the inner side surfaces 13, 13 on both sides of the groove 12. During this quenching, the work 10
Is set horizontally at the quenching position with the surface 11 on which the groove 12 is formed facing downward.

As shown in FIG. 1, the inner surface quenching apparatus for realizing the inner surface quenching method according to the first embodiment of the present invention is a state in which the surface of the workpiece 10 on which the grooves 12 are formed faces downward. 1-movable high-frequency heating coil 20 formed of a square tube made of copper and a work supporting part (not shown) supported by
And a cooling liquid injection jacket 30 connected to the rear in the moving direction.

The high frequency heating coil 20 has a pair of vertical portions 21, 21 facing the inner side surfaces 13, 13 on both sides of the groove 12 (however, the vertical portion 21 on the left side in the drawing is not shown). The vertical portions 21, 21 are connected to each other by a horizontal portion 22 below. Vertical parts 21, 2
Each upper end of 1 is connected to a coaxial connecting portion 24 via inclined portions 23, 23 inclined downward toward the inside, and further, via these connecting portions 24, a high frequency power source (not shown) is connected. Connected with leads. The high frequency heating coil 2
At 0, a core 25 made of a magnetic material such as ferrite is attached to improve the quenching efficiency.

The high frequency heating coil 20 is linearly driven in the coil central axis direction by a driving mechanism (not shown).

The cooling liquid jetting jacket 30 is a rectangular container made of an insulating material, which is flat in the longitudinal direction of the groove 12, and is connected to the rear side of the high-frequency heating coil 20 in the moving direction. Cooling liquid injection jacket 30 facing inner surfaces 13, 13 of the groove 12.
A plurality of nozzle holes 31 are provided on both side surfaces of each. The cooling liquid is supplied into the jacket through the liquid supply pipe 32 extending downward, and is supplied from the nozzle holes 31 on both sides to the groove 1.
It is injected on the inner side surfaces 13 of the second nozzle 13.

In order to perform quenching, a high-frequency current is supplied to the high-frequency heating coil 20 and a cooling liquid is supplied to the cooling liquid jet jacket 30, while the high-frequency heating coil 20 inside the groove 12 is moved in the coil central axis direction. It is performed by being driven linearly.

First, the high frequency heating coil 20 is used to form the groove 1.
The inner side surfaces 13 of the second member 2 are induction-heated from one end to the other end.

The heated inner surfaces 13, 13 are immediately quenched by the cooling liquid jetted from the cooling liquid jetting jacket 30 which moves inside the groove 12 following the high frequency heating coil 20. Therefore, the inner side surfaces 13, 13 are moved and hardened over the entire length.

At this time, the work 10 has the surface 11 on which the groove 12 is formed facing downward. Therefore, the cooling liquid jetted from the cooling liquid jetting jacket 30 to the inner side surfaces 13, 13 flows downward without accumulating inside the groove 12. As a result, overcooling of the inner bottom surface 14 of the groove 12 is avoided, and the preheating effect of the high-frequency heating coil 20 reduces the strain associated with the moving and hardening of the work 10. Specifically, when the work 10 as a whole tends to warp in an arc shape such that the surface 11 side of the work 10 in which the groove 12 is formed is recessed, the warpage is reduced.

Next, an inner surface quenching method according to the second embodiment of the present invention will be described with reference to FIG.

In the inner surface quenching method according to the second embodiment of the present invention, when the high frequency heating coil 20 and the cooling liquid injection jacket 30 relatively move inside the groove 12, the back surface of the work 10 facing upward. Above 15 is the high-frequency heat coil 2
0 and the second cooling liquid jetting jacket 40 that relatively moves in synchronization with the cooling liquid jetting jacket 30,
The inner surface quenching method according to the second embodiment differs from the inner surface quenching method according to the first embodiment described above in that The point is that the cooling liquid is also sprayed on the back surface 15 of 10.

The second cooling fluid injection jacket 40 in the internal quenching apparatus suitable for carrying out the internal quenching method according to the second embodiment is the cooling fluid injection described in the first embodiment. Similar to the jacket 30, it is a rectangular container made of an insulating material that is flat in the longitudinal direction of the groove 12. The difference from the cooling liquid jetting jacket 30 is that the groove 12 of the work 10 is
This is that a plurality of nozzle holes 41 are provided on the lower surface that faces the back surface 15 on which the holes are not formed. The cooling liquid is supplied into the jacket through the liquid supply pipe 42 extending upward, jetted from the lower nozzle hole 41, and collides with the back surface 15 (upper surface) of the work 10.

The second cooling liquid jet jacket 40 is
It is mechanically connected to the high frequency heating coil 20 and the cooling liquid jet jacket 30. Therefore, the high frequency heating coil 2
0 and the cooling liquid injection jacket 30 are linearly driven in the coil central axis direction.

Groove 1 of work 10 by this inner surface quenching device
In the induction hardening of No. 2, the groove 12 is moved by moving the inside of the groove 12 while supplying a high frequency current to the high frequency heating coil 20.
This is performed by inductively heating the inner side surfaces 13 of the nozzles 13 and moving the inside of the groove 12 while injecting the cooling liquid from the nozzle holes 41 of the cooling liquid injection jacket 30.

As described above, the second cooling liquid jetting jacket 40 located above the work 10 jets the cooling liquid downward, and along with the high frequency heating coil 20 and the cooling liquid jetting jacket 30 in the coil central axis direction. Since it moves linearly, when the inner side surfaces 13, 13 of the groove 12 of the work 10 are quenched, the back surface 15 (top surface) where the groove 12 is not formed
Is supplementarily cooled by the cooling liquid ejected from the second cooling liquid injection jacket 40. Then, the thermal history on the back surface side (upper surface side) of the work 10 is controlled by adjusting the amount of cooling liquid jetted from the second cooling liquid jet jacket 40.

Even if stagnation of the cooling liquid in the inside of the groove 12 is avoided, the back surface side (upper surface side) tends to be insufficiently cooled than the front surface side (lower surface side) where the groove 12 is formed in order to reduce distortion. In this case, the heat history control on the back surface side (upper surface side) by this cooling further reduces the strain caused by the moving and hardening of the work 10.

Next, an inner surface quenching method according to the third embodiment of the present invention will be described with reference to FIG.

Such an inner surface quenching apparatus is the second one shown in FIG.
In the inner surface quenching apparatus suitable for carrying out the inner surface quenching method according to the embodiment of the present invention, the second cooling liquid injection jacket 4 is provided.
The configuration is such that 0 is changed to the second high-frequency heating coil 50. The second high-frequency heating coil 50 is a one-turn pin coil formed of a copper rectangular tube, and has a core 52 attached thereto. Such second high frequency heating coil 5
In the case of 0, the back surface 15 (top surface) of the work 10 on which the groove 12 is not formed is supplementarily heated by the heating conductor 51 while linearly moving in the coil central axis direction together with the high frequency heating coil 20 and the cooling liquid injection jacket 30. .

In order to reduce distortion by avoiding the retention of the cooling liquid inside the groove 12, the front surface side (lower surface side) where the groove 12 is formed is heated more than the rear surface side (upper surface side). With the heat history control on the back surface side (upper surface side) due to this heating, the strain due to the moving and hardening of the work 10 is further reduced.

In the example of FIGS. 1 to 3, the inner surface 1 of the groove 12 is
Only 3 and 13 are quenched, but the inner bottom surface 14 of the groove 12
The present invention is applicable to the case of quenching only or both. Further, the shape of the groove 12 is not limited to the substantially square shape, but may be any shape such as a U groove and a dovetail groove. Second cooling liquid jet jacket 40 and second
Both of the high frequency heating coil 50 and the high frequency heating coil 20 of FIG.
It is also possible to arrange it above 0 and use it properly.

[0036]

According to the first aspect of the present invention, the inner surface of the groove is continuously heated by the high-frequency heating coil that relatively moves inside the groove formed on the surface of the work, and the groove is continuously connected to the high-frequency heating coil. Is a quenching method for the inner surface of a groove, in which the heating surface of the groove is rapidly cooled by a cooling liquid injection jacket that relatively moves inside the groove. The heating coil and the cooling liquid injection jacket are designed to move relative to each other.

Therefore, in the case of this inner surface quenching method, when the high-frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, the surface of the work in which the groove is formed faces downward. Since the cooling liquid ejected from the jacket is immediately discharged to the outside of the groove and the cooling liquid does not collect inside the groove, the distortion of the work can be reduced by the preheating effect of the high frequency heating coil 20.

Further, in the inner surface quenching method according to the second aspect, when the high frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, the high frequency heating coil and the cooling are provided on the upper surface of the back surface of the work. Since the back surface of the work is supplementarily cooled by the second cooling liquid injection jacket that relatively moves in synchronization with the liquid injection jacket, the back surface of the work is synchronized with the high frequency heating coil and the cooling liquid injection jacket. Since the back surface of the work is supplementarily cooled by the second cooling liquid injection jacket that relatively moves above, the heat history on the back surface side of the work is intentional in addition to the discharge of the cooling liquid to the outside of the groove. Is controlled, the distortion of the work due to quenching is further reduced.

Further, the inner surface quenching method according to claim 3 is
When the high frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, the second high frequency heating coil relatively moves on the back surface of the workpiece facing upward in synchronization with the coil and the cooling liquid jetting jacket. Since the back surface of the work is supplementarily heated, by the second high-frequency heating coil that relatively moves on the back surface of the work in synchronization with the high-frequency heating coil and the cooling liquid injection jacket,
Since the back side of the work is heated supplementarily,
In addition to discharging the cooling liquid to the outside of the groove, the heat history on the back surface side of the workpiece is intentionally controlled, so that the distortion of the workpiece due to quenching is further reduced.

On the other hand, an inner surface quenching apparatus according to a fourth aspect of the present invention is an inner surface quenching apparatus for quenching the inner surface of a groove formed on the surface of a work, wherein the work is moved downward on the surface where the groove is formed. And a high-frequency heating coil that relatively moves inside the groove of the work, and a cooling liquid injection jacket that relatively moves inside the groove following the high-frequency heating coil. There is.

Therefore, in the case of this inner surface quenching apparatus, when the high frequency heating coil and the cooling liquid injection jacket relatively move inside the groove, the surface of the work in which the groove is formed is directed downward. Since the cooling liquid ejected from the jacket is immediately discharged to the outside of the groove and the cooling liquid is not accumulated inside the groove, the distortion of the work can be reduced by the preheating effect of the high frequency heating coil.

The inner surface quenching apparatus according to a fifth aspect of the invention relatively moves on the back surface of the work facing upward in synchronization with the high frequency heating coil and the cooling liquid jetting jacket, and assists the back surface of the work. It has a second cooling liquid jet jacket for cooling. Since the back surface of the work is supplementarily cooled by the second cooling liquid jetting jacket, the heat history on the back surface side of the work is intentionally controlled in addition to the discharge of the cooling liquid to the outside of the groove. Therefore, the work distortion caused by quenching is further reduced.

Further, the inner surface quenching method according to claim 6 is
Since the second high frequency heating coil is provided which moves in synchronization with the high frequency heating coil and the cooling liquid jetting jacket on the back surface of the workpiece facing upward, and secondarily heats the back surface of the workpiece. Since the backside of the work is supplementarily heated by the high-frequency heating coil No. 2, in addition to discharging the cooling liquid to the outside of the groove, the heat history on the backside of the work is intentionally controlled, so that the work accompanying quenching Distortion is further reduced.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an inner surface quenching method and apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of an inner surface quenching method and apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic explanatory diagram of an inner surface quenching method and apparatus according to a third embodiment of the present invention.

FIG. 4 is a schematic explanatory view illustrating a conventional inner surface quenching method.

[Explanation of symbols]

 10 Work 11 Surface of Work 12 Groove of Work 13 Inner Side of Groove 14 Inner Bottom of Groove 15 Back of Work 20 High Frequency Heating Coil 30 Coolant Injection Jacket 31 Nozzle Hole 40 Second Coolant Injection Jacket 41 Nozzle Hole 50 Second High frequency heating coil

Claims (6)

[Claims] 1. A cooling liquid jetting jacket that continuously heats the inner surface of the groove by a high-frequency heating coil that relatively moves inside the groove formed on the surface of the workpiece, and that relatively moves inside the groove following the high-frequency heating coil. According to the method of quenching the inner surface of a groove for rapidly cooling the heating surface of the groove, the high frequency heating coil and the cooling liquid injection jacket are relatively moved inside the groove with the surface of the work on which the groove is formed facing downward. Internal quenching method characterized by: 2. When the high-frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, the relatively high frequency heating coil and the cooling liquid jetting jacket relatively move on the back surface of the workpiece facing upward. 2. The inner surface quenching method according to claim 1, wherein the back surface of the work is supplementarily cooled by the cooling liquid injection jacket. 3. When the high-frequency heating coil and the cooling liquid jetting jacket relatively move inside the groove, the second relatively moving in synchronization with the coil and the cooling liquid jetting jacket on the upper surface of the back surface of the workpiece facing upward. With the high frequency heating coil,
The inner surface quenching method according to claim 1 or 2, wherein the back surface of the work is supplementarily heated. 4. An inner surface quenching device for quenching the inner surface of a groove formed on the surface of a work, the work supporting portion supporting the work in a state in which the surface having the groove is directed downward, An inner surface quenching device comprising: a high-frequency heating coil that relatively moves inside a groove of a work; and a cooling liquid injection jacket that relatively moves inside the groove following the high-frequency heating coil. 5. A second cooling liquid jetting jacket, which moves in synchronization with the high-frequency heating coil and the cooling liquid jetting jacket, on the rear surface of the workpiece facing upward so as to supplementarily cool the rear surface of the workpiece. 5. The method according to claim 4, wherein
Internal quenching device described in. 6. A second high-frequency heating coil is provided which moves in synchronization with the high-frequency heating coil and the cooling liquid jetting jacket on the rear surface of the workpiece facing upward to supplementarily heat the rear surface of the workpiece. The inner surface quenching device according to claim 4 or 5, wherein