JPH0638109Y2 - Induction hardening equipment for inner peripheral surface of tubular parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an induction hardening apparatus for an inner peripheral surface of a tubular part, and more specifically, a heating coil cooling passage and a heated body cooling passage are formed. A hollow heating coil and a cooling jacket are detachably attached to the coil supporting body, and the heating coil and the cooling jacket are positioned with respect to the coil supporting body by utilizing respective passages, whereby a workpiece is formed. For example, the present invention relates to an induction hardening apparatus for an inner peripheral surface of a cylindrical part, which enables accurate and economical quenching of inner peripheral surfaces of various constant velocity joints having different sizes.

[Background of the Invention] Generally, in metal parts, a wide range of work is performed to form a hardened layer by high frequency induction heating on a sliding part where other parts slide, and to improve the strength and wear resistance of the sliding part. Has been done in. For example, a transmission ball or the like is in sliding contact with the inner peripheral surface of a constant velocity joint that connects a differential device and a wheel shaft in a wheel drive portion of an automobile, and thus a hardened layer is formed on this inner peripheral surface.

Therefore, various methods and devices have been proposed for performing quenching work on the inner peripheral surface of a tubular component such as the constant velocity joint. For example, Japanese Patent Publication No. 57-55767 discloses its technical idea. ing. This is shown in FIG.

That is, in the drawing, reference numeral 2 indicates an induction hardening apparatus according to the related art, and the hardening apparatus 2 is a heating coil 4 and a magnetic member 6 which are connected to an RF power source (not shown).
Including and A fluid supply passage 8 is provided at the center of the magnetic member 6.
The fluid supply passage 8 communicates with a plurality of fluid ejection ports 10 formed in the radial direction of the magnetic member 6 and the inside of the fluid supply passage 8 has a fluid discharge passage. Twelve are provided coaxially. The magnetic member 6
An insulating plate 14 is provided at the end of the.

In such a structure, after the quenching device 2 is inserted into the cylindrical body 16 which is the object to be heated and the insulating plate 14 is brought into contact with the inner end surface of the cylindrical body 16, a high frequency power source (not shown) is driven to drive the cylindrical body. The inner peripheral surface of 16 is induction heated. Next, when the quenching device 2 and the cylindrical body 16 are displaced relative to each other by a predetermined distance, and a cooling fluid is supplied to the fluid supply passage 8, the cooling fluid flows from the fluid ejection port 10 to the inner peripheral surface of the cylindrical body 16. After being injected and cooling the inner peripheral surface, the fluid is discharged to the outside through the fluid discharge passage 12 and the gap between the inner peripheral surface and the heating coil 4. As a result, the inner peripheral surface of the cylindrical body 16 is rapidly cooled and the hardened layer
18 is formed.

However, in the above-mentioned conventional technique, since the fluid supply passage 8 and the fluid discharge passage 12 are coaxially provided inside the heating coil 4, the diameter of the heating coil 4 becomes large. Therefore, in the cylindrical body 16 having a relatively small size, a desired gap cannot be defined between the inner peripheral surface of the cylindrical body 16 and the heating coil 4, and a sufficient cooling fluid cannot be supplied to the inner peripheral surface heated by induction. There are cases. As a result, it becomes difficult to accurately quench the inner peripheral surface of the cylindrical body 16, and the desired hardened layer is obtained.
The inconvenience of not getting 18 is exposed.

Moreover, in the quenching device 2, the shape of the heating coil 4 is selected in accordance with the shape of the inner peripheral surface of the predetermined cylindrical body 16, and therefore various cylindrical bodies having different sizes and shapes are selected.
When carrying out the quenching work on the 16 pieces, it is necessary to prepare a plurality of quenching apparatuses 2 corresponding to the shapes of the respective cylindrical bodies 16. As a result, it has been pointed out that the maintenance and management of each quenching device 2 becomes complicated and that it is extremely uneconomical.

Furthermore, as an induction hardening apparatus of this type, its technical idea is disclosed in Japanese Utility Model Publication No. 57-6531. That is, in this conventional technique, a hollow heating coil made of copper is formed into a spiral shape corresponding to the inner peripheral surface shape of the object to be heated,
The heating coil is fixed to a tubular body made of a heat-resistant insulating material, and an opening is formed in the heating coil to communicate the inside of the heating coil with the tubular body. Further, a plurality of fluid outlets are formed on the outer peripheral portion of the tubular body.

Therefore, the tubular body is inserted into the body to be heated and the high frequency power source is driven to induction-heat the inner peripheral surface of the body to be heated via the heating coil. Then, when a cooling fluid is supplied into the heating coil, the cooling fluid cools the heating coil and is supplied into the tubular body through the opening formed in the heating coil, and then the fluid outlet of the tubular body. Is sprayed from the inner peripheral surface of the object to be heated. As a result, quenching work is performed on the inner peripheral surface of the object to be heated.

However, in the above-mentioned conventional technique, since the hollow heating coil is spirally wound and molded along the inner surface of the object to be heated, the rigidity of the heating coil itself is lowered, and the heating coil has a desired shape. It is quite difficult to mold accurately. For this reason, the dimensional accuracy of the heating coil varies, and in particular, when the object to be heated is thin, a partial temperature difference is caused in the quenched portion of the object to be heated, and quenching distortion, quenching cracks, etc. occur. The inconvenience has been pointed out.

Further, when the heating coil itself is thermally deformed or deteriorated, it is not possible to replace only this heating coil, and it is necessary to replace the entire quenching device with a new quenching device, which is extremely uneconomical. Becomes apparent. Moreover, as in the case of the conventional technique described above with reference to FIG. 1, there is a drawback that a plurality of quenching devices must be prepared corresponding to various heated objects having different shapes.

[Object of the Invention] The present invention has been made to overcome the above-mentioned inconvenience, and provides a coil supporting body, a hollow heating coil detachably mounted on the coil supporting body, and a cooling jacket. The coil support body defines a first passage for cooling the heating coil and a second passage for cooling the object to be heated, and connects the first and second passages with the heating coil and the cooling jacket. At the same time, the heating coil and the cooling jacket are simultaneously positioned with respect to the coil support body, thereby downsizing the entire heating coil and efficiently supplying cooling water even to a relatively small heated object. It is possible to satisfactorily carry out quenching work, and furthermore, the heating coil and the cooling jacket are accurately positioned and mounted on the coil support body for highly accurate quenching. To provide an induction hardening apparatus for an inner peripheral surface of a cylindrical part, which can perform the work and can easily cope with objects to be heated having various shapes by exchanging only the heating coil. With the goal.

[Means for Achieving the Purpose] In order to achieve the above-mentioned object, the present invention is a high-frequency induction heating method for induction hardening an inner peripheral surface of a tubular part, and then introducing a cooling fluid to the inner peripheral surface for quenching. A quenching apparatus, comprising: a coil support body, a hollow heating coil detachably attached to the coil support body, and a cooling jacket detachably attached to the coil support body to draw a cooling fluid to the inner peripheral surface. The coil support body forms a first passage for supplying a cooling fluid to the cooling jacket and a second passage for supplying a cooling fluid to the passage in the heating coil, and the first and second The passage is configured as a fitting portion for positioning the cooling jacket and the heating coil with respect to the coil supporting body.

[Embodiment] Next, a preferred embodiment of an induction hardening apparatus for an inner peripheral surface of a tubular component according to the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 2, reference numeral 20 indicates an induction hardening device for the inner peripheral surface of the tubular part according to the present embodiment. The quenching device 20
Includes a coil support body 22 made of a non-conductive material, for example, a resin material such as phenol resin. The coil support body 22 is integrally formed of a rectangular base portion 24 and a column portion 26 that bulges vertically upward on the upper surface of the base portion 24.

The pillar portion 26 is provided with supporting corner bodies 28a to 28c which are spaced apart from the center by a predetermined angle, for example, 120 ° and bulge outward and extend integrally with the pillar portion 26 in the vertical direction. Stepped portions 30a to 30c are formed on the upper side of the support corner bodies 28a to 28c by cutting to a predetermined height position, and penetrate the base portion 24 from the upper end surface portions of the respective support corner bodies 28a to 28c. Then, the first passage 32a to the third passage 32c for the cooling fluid are bored (see FIG. 3).

On the other hand, in the pillar portion 26, a notch portion 34 having a rectangular cross section, which is between the supporting corners 28a and 28b and extends in the axial direction of the pillar portion 26.
At the same time, the cylindrical portion 36 is provided on the upper end surface of the pillar portion 26 so as to bulge vertically upward by a predetermined length. A spiral groove 38 is formed on the outer periphery of the cylindrical portion 36, and a fourth passage 40 penetrating the pillar portion 26 and the base portion 24 is formed at the center of the cylindrical portion 36. Further, in the columnar portion 26, outside the cylindrical portion 36, parallel to the fourth passage 40, a fifth passage 42a to an eighth passage 42d.
Is formed. The fifth passage 42a to the eighth passage 42d extend into the base portion 24 and then bend at about 90 °, and
42a and the seventh passage 42c open outward from one side of the base portion 24, while the sixth passage 42b and the eighth passage 42d form the base portion.
24 Open outward from the other side.

Then, a cooling jacket is attached to the end portions of the supporting corner members 28a to 28c.
46a to 46c are detachably attached. The cooling jackets 46a to 46c are made of brass, for example, and are used as the support members 28.
It has cylindrical portions 48a to 48c which are fitted to the first passage 32a to the third passage 32c of a to 28c and have a positioning action. As shown in FIG. 5, the cylindrical portions 48a to 48c are the cooling jackets 46a.
To the chambers 50a to 50c defined in the chambers 46a to 46c, and slit openings 52a to 52c for opening the chambers 50a to 50c to the outside while being connected to the upper edge of each cooling jacket 46a to 46c. It is formed. Also, cooling jacket 46a
The upper portions of to 46c are formed to correspond to the shape of the heating coil 54.

The heating coil 54 is composed of a rectangular tube member substantially made of a copper material, and has a polygonal shape corresponding to the inner peripheral surface shape of a later-described object to be heated and is provided at intervals of 120 °. 56a to 56c and the ring portion 58 for fitting the cylindrical portion 36 of the columnar portion 26, and the lead portion inserted into the notch 34 of the columnar portion 26.
Including 60a and 60b. For this reason, a passage 62 having a rectangular cross section is defined in the heating coil 54, and the passage 62 is opened to the outside through tubular portions 64a to 64d provided in the ring portion 58.
In this case, the tubular portions 64a to 64d are the fifth passages 42a of the columnar portion 26.
Through the function of positioning the heating coil 54 by fitting into the eighth passage 42d and the function of communicating the passage 62 with the respective passages 42a through 42d (see FIG. 5).

Further, the lead portions 60a and 60b extend vertically downward along the cutout portion 34 of the columnar portion 26, and then bend at about 90 ° and extend in the horizontal direction. The ends of the lead portions 60a and 60b are connected to a high frequency power source (not shown) and communicate with fluid discharge ports (not shown).

Further, a pair of ferrite cores 66a and 66b are engaged with the respective heating portions 56a to 56c from above and below. The ferrite cores 66a, 66b have a substantially polygonal shape corresponding to the shape of the heating portions 56a to 56c, and the swelling portions 68a fitted inside the heating portions 56a to 56c on the respective facing surface portions, 68b is integrally provided. Note that at least the heating units 56a to 5
The ferrite core 66a that engages with the lower side of 6c has a cylindrical portion 64a.
The arc-shaped relief portion 70 is formed so as not to interfere with the to 64d.

Therefore, a pressing plate 72 is provided which abuts on each ferrite core 66b and presses the heating coil 54 against the coil supporting body 22. The pressing plate 72 is made of a phenol resin or the like, has a substantially ring shape, and has pressing pieces 74a to 74c that extend outward in the radial direction at a predetermined angle (120 °) apart from each other and support the ferrite core 66b. Furthermore, a rectangular nut member made of phenolic resin or the like is also provided on the holding plate 72.
The nut member 76 is mounted on the screw groove 38 of the cylindrical portion 36.

The induction hardening apparatus for the inner peripheral surface of the tubular component according to the present embodiment is basically constructed as described above, and its operation and effect will be described below.

In this case, as shown in FIGS. 4 and 5, a constant velocity joint 90 is used as the object to be heated, and the work of quenching the inner peripheral surface 92 thereof will be described.

Therefore, first, a constant velocity joint is attached to the coil support body 22.
The heating coil 54 corresponding to 90 is attached. That is, a predetermined cooling jacket 46a is provided in the first passage 32a to the third passage 32c formed in the support corners 28a to 28c of the coil support body 22.
The tubular parts 48a to 48c of the to 48c are fitted. Therefore, the cooling jackets 46a to 46c are positioned at the respective step portions 30a to 30c, and the first passage 32a to the third passage 32c communicate with the chambers 50a to 50c.

Then, the ring portion 58 of the heating coil 54 is replaced with the cylindrical portion of the columnar portion 26.
The tubular portion 64 fitted on the ring portion 58 and fitted on the 36
The lead portions 60a and 60b are inserted into the cutout portion 34, while the a to 64d are fitted into the fifth passage 42a to the eighth passage 42d. that time,
A pair of ferrite cores 66a and 66b are attached to the heating portions 56a to 56c of the heating coil 54 from above and below, respectively, and a pressing plate with the pressing pieces 74a to 74c in contact with the respective ferrite cores 66a and 66b. 72 is placed above the heating coil 54. Then, the nut member 76 is attached to the cylindrical portion 36 from above the holding plate 72.
The heating coil 54 is attached to the coil supporting body 22 by screwing it into the spiral groove 38.

On the other hand, the lead portions 60a and 60b of the heating coil 54 are connected to a high frequency power source (not shown), and the openings of the lead portions 60a and 60b are communicated with a fluid discharge port (not shown). Also,
First passage 32a to third passage 32c formed in the base portion 24
Fluid passages (not shown) are connected to the fourth passage 40, the fifth passage 42a to the eighth passage 42d, respectively.

After assembling the quenching device 20 in this way, as shown in FIG. 4, the constant velocity joint 90 and the quenching device 20 are relatively displaced close to each other, and, for example, the end portion of the nut member 76 is moved to the above-mentioned position. Abut on the inner end surface of the quick joint 90. next,
While the quenching device 20 and the constant velocity joint 90 are displaced relative to each other at a predetermined speed, a high frequency power source (not shown) is driven to supply a high frequency current to the heating coil 54 via the lead parts 60a and 60b. Here, ferrite cores 66a and 66b having high magnetic permeability are attached to both sides of the heating portions 56a to 56c, respectively, and the ferrite cores 66a and 66b and the heating portions 56a to 56c and the constant velocity joint 90 are attached. A magnetic closed circuit is formed between the inner peripheral surface 92 and the inner peripheral surface 92, and the inner peripheral surface 92 is efficiently induction-heated.

After heating a predetermined portion of the inner peripheral surface 92 by the quenching device 20, the driving of the high frequency power supply is stopped. And the base part 24
The first passage 32a to the third passage 32c and the fourth passage 40 penetrating the lower surface of the base plate 24 and the fifth passage 42a to the seventh passage 42c formed on both sides of the base portion 24 are provided with a cooling fluid, for example, , Supply cooling water. Therefore, as shown in FIG.
Cooling water is introduced into the chambers 50a to 50c of the cooling jackets 46a to 46c, which communicate with the passages 32a to the third passages 32c through the tubular portions 48a to 48c, and the cooling water is fed from the openings 52a to 52c at constant speeds. It is ejected onto the inner peripheral surface 92 of the joint 90. Further, the cooling water supplied to the fourth passage 40 passes through the inside of the cylindrical portion 36 of the columnar portion 26 and is similarly jetted to the inner peripheral surface 92. As a result, the heated portion of the inner peripheral surface 92 is rapidly cooled and the hardened layer 94 is formed.

On the other hand, the cooling water supplied to the fifth passage 42a and the sixth passage 42b is introduced into the passage 62 of the heating coil 54 from the tubular portions 64a and 64b, and a part of each is illustrated via the lead portions 60a and 60b. Not discharged to the fluid outlet. Further, the cooling water introduced into the seventh passage 42c is supplied from the tubular portion 64c into the passage 62 of the heating coil 54, and then is discharged from the tubular portion 64d to the outside through the eighth passage 42d. Therefore, the heating coil 54 itself is cooled.

In this case, in this embodiment, the coil support body 22 is provided with the first passage 32a to the third passage 32c and the fourth passage 40 for cooling the inner peripheral surface 92 of the constant velocity joint 90, and the heating coil 54 is cooled. The fifth passage 42a to the eighth passage 42d are formed for this purpose. Therefore, the cooling jackets 46a to 46c can be directly attached to the coil support body 22, and the heating coil 54 itself can be downsized. Therefore, in particular, even when the size of the constant velocity joint 90 is small, a sufficient space can be secured between the inner peripheral surface 92 and the heating portions 56a to 56c, and the cooling water can be supplied to the inner peripheral surface 92. Hardened layer with excellent quality that ensures efficient quenching and reliable quenching
Is obtained.

Moreover, the passage 62 of the heating coil 54 and the respective passages 42a to 42d
The heating coil 54 is positioned with respect to the coil support body 22 via tubular portions 64a to 64d for communicating with each other. Therefore, the heating coil 54 can be accurately attached to the coil support body 22, and the heating coil 54 can be positioned with high accuracy with respect to the inner peripheral surface 92 of the constant velocity joint 90 to make the inner peripheral surface 92 uniform. Induction heating is possible.

Similarly, the tubular portions 48a to 48c of the cooling jackets 46a to 46c.
By fitting the first passage 32a to the third passage 32c,
The passages 32a to 32c are communicated with the chambers 50a to 50c and the cooling jackets 46a to 46c are positioned. Therefore, the cooling jackets 46a to 46c can be accurately arranged with respect to the inner peripheral surface 92 of the constant velocity joint 90.
It becomes possible to cool 92 well. As a result, a high-quality hardened layer 94 free from quenching distortion, quenching cracks, etc. can be obtained.

Further, as shown by the chain double-dashed line in FIG. 4, if the pressing pieces 74a to 74c of the pressing plate 72 are configured so as to be in sliding contact with the inner peripheral surface 92, the quenching device 20 and the inner peripheral surface 92 will face each other. There is also an advantage that the position can be secured more accurately and good quenching work can be performed.

Further, when the heating coil 54 itself is subjected to thermal deformation or the like, or when the size of the constant velocity joint 90 that is the object to be heated is different, it is not necessary to replace the entire quenching device 20 as in the conventional case, and the heating is performed. The coil 54 need only be replaced with the desired heating coil 54. That is, the assembling work of the quenching device 20 described above is performed in reverse, and the heating coil 54 is set to the ferrite core.
The coils 66a and 66b are integrally removed from the coil support body 22, and the cooling jackets 46a to 46c are detached from the support corners 28a to 28c as necessary. Next, as described above, the work of attaching the new heating coil 54 to the coil support body 22 integrally with the new ferrite cores 66a and 66b may be performed.
As described above, only the heating coil 54 needs to be replaced for the constant velocity joint 90 having different dimensions.
It is possible to obtain the effect that the replacement work is easy and extremely economical.

[Advantages of the Invention] As described above, according to the present invention, the first device for cooling the object to be heated is provided.
And a hollow heating coil and a cooling jacket which are detachably attached to the coil support body, and the heating coil has a second passage for cooling the heating coil and a second passage for cooling the heating coil. By connecting the cooling jacket to the first and second passages, the heating coil and the cooling jacket can be positioned at the same time. Therefore, the heating coil can be accurately positioned with respect to the coil supporting body, and the effect that the heated object can be uniformly induction-heated is obtained. Moreover, by directly mounting the cooling jacket on the coil supporting body, the heating coil itself can be downsized. In particular, even in the case of a heated object having a small size, the heating coil and the inner peripheral surface which is the heated portion are A sufficient space can be defined between them. Therefore, there is an advantage that cooling water can be effectively supplied to the inner peripheral surface and a highly accurate quenching process can be performed. Further, when the heating coil is thermally deformed or when the size of the object to be heated is different, only the heating coil may be replaced with the coil support body. As a result, it is possible to obtain a substantial advantage that it is extremely economical as compared with the conventional one in which the entire quenching apparatus is exchanged for each object to be heated.

Although the present invention has been described with reference to the preferred embodiment, the present invention is not limited to this embodiment.
It goes without saying that various improvements and design changes can be made without departing from the scope of the present invention.

[Brief description of drawings]

FIG. 1 is a partially omitted vertical explanatory view of a quenching device according to the prior art, FIG. 2 is an exploded perspective view of the quenching device according to the present invention, and FIG. 3 is a plan view of a coil supporting body constituting the quenching device. FIG. 4 is a partially omitted explanatory view when quenching an object to be heated by the quenching apparatus, and FIG. 5 is a sectional explanatory view when the quenching apparatus is cut along the line VV shown in FIG. 20 ... Quenching device, 22 ... Coil support body 32a-32c, 40, 42a-42d ... Passage 46a-46c ... Cooling jacket 54 ... Heating coil, 62 ... Passage

Claims (1)

[Scope of utility model registration request] 1. An induction hardening apparatus for quenching by introducing a cooling fluid to the inner peripheral surface after induction heating of the inner peripheral surface of a tubular component, the coil supporting main body being attached to and detached from the coil supporting main body. A hollow heating coil that is freely mounted and a cooling jacket that is removably mounted on the coil support body and draws a cooling fluid to the inner peripheral surface, and the coil support body supplies the cooling fluid to the cooling jacket. First to do
And a second passage for supplying a cooling fluid to the passage in the heating coil, and a fitting for positioning the first and second passages with respect to the cooling jacket and the heating coil with respect to the coil support body. An induction hardening device for an inner peripheral surface of a cylindrical part, which is configured as a joint part.