JPH0660096U - High frequency heating coil body - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] When quenching the surface of a work in which openings or grooves in the work are formed, there are no quench cracks around the openings or the grooves and it is uniform. Provided is a heating coil body which can be heated to a high temperature. [Structure] The heating coil body 80 has three heating coils 10, 20, 30 of the same shape which are provided so as to face the surface 120 to be heated. These heating coils are arranged at intervals in the circumferential direction over substantially half the circumference of the surface to be heated, and each heating coil is arranged along the outer circumference of the surface to be heated. , 20a, 30a and the second heating conductors 10b, 20b, 30b arranged substantially along the inner circumference of the surface to be heated, and one end and the other end of the first and second heating conductors are connected to each other. Third heating conductor arranged substantially in the radial direction of the heating surface
10c, 20c, 30c and the fourth heating conductor 10d, 20d, 30d
And the heating coils are arranged such that the distances R1, R2, R3 from the center 110 of the heated surface to the outer surface of each second heating conductor are different from each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a high-frequency heating coil body (hereinafter referred to as high-frequency heating) that is used when quenching the surface of the work in which holes are formed in the work or the surface of the work in which grooves are formed. The coil body is also simply referred to as a heating coil body).

[0002]

[Prior art]

 Hereinafter, a conventional technique will be described with reference to the drawings. 7 to 9 are drawings for explaining the work. FIG. 7 is a plan view of the work, FIG. 8 is a cross-sectional view taken along the line XX of FIG. 7, and FIG. It is a Y line arrow cross section explanatory drawing. FIG. 10 is a cross sectional view taken along the line ZZ of FIG. 7 and a cross sectional explanatory view of a conventional heating coil.

The work 100 picked up here is a flow distributor used in, for example, a hydraulic circuit of a traveling system of a bulldozer, and has a disk shape having a cylindrical hole 101 in the center as shown in FIGS. The upper surface 111 (upper side in FIG. 8) and the lower surface 112 (lower side in FIG. 8) are both formed into an annular flat surface. An annular groove 108 is formed near the periphery of the upper surface 111, and a plurality of taps 103 and a plurality of bolt holes 102 penetrating from the upper surface 111 to the lower surface 112 are provided inside the groove 108. .

Reference numerals 104, 105, and 106 denote oil holes that open to the upper surface 111, respectively, and these oil holes 104, 105, and 106 are curved, and the opening of the lower surface 112 is the opening of the upper surface 11 1. Not directly under. Further, on the upper surface 111, a groove 107 is formed in a substantially pentagonal shape so as to surround the oil holes 104, 105 and 106 so as to accommodate an O-ring (not shown).

On the upper surface 111, a hardened layer 113 is formed on the heated surface 120 which is an annular portion between the outer circumference 121 (radius Ra) and the inner circumference 122 (radius Rb) with the axis 110 of the work 100 as the center 110. It is required to To form the hardened layer 113, as shown in FIG. 10, an annular heating coil 200 formed so as to correspond to the shape of the heated surface 120 is arranged close to the heated surface 120 so as to face the heated surface 120. Then, while rotating the workpiece 100 around the center 110, a high frequency current is applied to the heating coil 200 for a predetermined time to heat it, and then a cooling liquid is sprayed from a jacket (not shown) onto the heated surface 120 to cool it. .

A step 201 is provided on the surface 201 of the heating coil 200 facing the heated surface 120, and the closer the heated surface to the center 110, the larger the gap distance between the heated surface 120 and the heating coil 200. The reason for this is that when such a step is not provided, the annular induced current generated on the heated surface 120 concentrates on the center 110 side, and the formed hardened layer is deep on the center 110 side and extends from the center 110 side. This is because the distance becomes shallower and the depth does not become uniform.

[0007]

[Problems to be solved by the device]

 However, when the above-mentioned heating coil 200 is used to quench the heated surface 120 of the upper surface 111 of the work 100, the following problems occur. That is, the high-frequency current generated in the heated surface 120 and flowing in an annular shape is concentrated around the openings of the oil holes 104, 105, and 106 and around the O-ring groove 17 as compared with the other portions, so that the oil holes The openings of 104, 105, and 106 and the periphery of the groove 17 are likely to be overheated and to cause quench cracking.

The present invention has been made in view of the above circumstances, and when an annular heated surface having holes or grooves formed on its surface is heated for quenching, these openings and The purpose of the present invention is to provide a heating coil body capable of uniformly heating without causing cracking around the groove.

[0009]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the heating coil body of the present invention is arranged so as to substantially oppose an annular heated surface having a predetermined width and having holes or grooves formed therein so as to heat the heated surface. A high-frequency heating coil body having a plurality of high-frequency heating coils, wherein the high-frequency heating coils are arranged at intervals in the circumferential direction of the surface to be heated over substantially half the circumference of the surface to be heated. The high frequency heating coil includes a first heating conductor arranged substantially along the outer circumference of the heated surface, a second heating conductor arranged substantially along the inner circumference of the heated surface, and first and second heating conductors. The high-frequency heating coil is provided with third and fourth heating conductors, which are respectively connected to one end of the conductor and the other end thereof and are arranged substantially in the radial direction of the surface to be heated. The distance of each heating coil to the second heating conductor is different from each other. It is arranged.

The high-frequency heating coils are three of the first to third high-frequency heating coils, and the first high-frequency heating coil has a substantially inner portion and a substantially central portion of the surface to be heated, and a second high-frequency heating coil. It is preferable that the high-frequency heating coil heats a substantially central portion of the heated surface, and the third high-frequency heating coil heats a substantially central portion and a substantially outer portion of the heated surface.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 to 6 are drawings for explaining a heating coil body of this embodiment, FIG. 1 is a sectional view taken along the line AA of FIG. 4, FIG. 2 is an electric circuit diagram, and FIG. A perspective view, FIG. 4 is a perspective view of one heating coil, FIG. 5 is a sectional view taken along the line BB in FIG. 5, and FIG. 6 is a high frequency quenching apparatus using the heating coil of this embodiment. It is a schematic front explanatory drawing. As the work, the same work 100 as described in the related art is adopted, and thus the description of the work will be omitted. Further, the same components as those described in the conventional technique are designated by the same reference numerals.

As shown in FIG. 1, the heating coil body 80 of the present embodiment is arranged so as to be substantially opposed to the annular surface 120 to be heated of the work 100, and the three heating coil bodies 80 are heated to heat the surface 120 to be heated. The basic configuration is that the same heating coils 10, 20, and 30 (first, second, and third heating coils) are provided. The heating coils 10, 20, and 30 are arranged at intervals in the circumferential direction of the surface to be heated 120 over approximately half the circumference of the surface to be heated 120.

The structure of the heating coil body 80 will be described in detail with reference to FIGS. 2 and 3. First, the electric circuit will be described. The heating coil body 80 includes power feeding conductors 41 and 42 to which a high frequency power source 90 is connected at one end, and three heating coil circuits 81 to 83 connected in series between the other ends of the power feeding conductors 41 and 42. I have it.

The heating coil circuit 81 includes the heating coil 10, a pair of linear feeding conductors 13 and 14, a pair of connecting blocks 12 and 15, and a pair of substantially arc-shaped feeding conductors 11 and 16. I have it. The heating coil 10 has a first heating conductor 10a formed so as to be a part of an arc centered on the center 110 of the heated surface 120 and having a radius substantially equal to the radius Ra of the outer circumference 121 of the heated surface 120, Similarly, the second heating conductor 10b, which is formed so as to be centered around the center 110 and whose radius is slightly smaller than the radius Rb of the inner circumference 122 of the heated surface 120, the first heating conductor 10a, and the second heating conductor 10a. One end and the other end of the heating conductor 10b are connected to each other, and a linear third heating conductor 10c and a fourth heating conductor 10d which are formed in the radial direction of the surface 120 to be heated are provided. Therefore, the maximum width C in the radial direction of the heating coil 10 from the first heating conductor 10a to the second heating conductor 10b is, in this embodiment, the half radius Ra of the outer circumference of the heated surface 120 and the inner circumference 122. A little larger than the difference from the radius Rb. The same applies to the heating coils 20 and 30.

Feeding conductors 13 and 14 are connected to the cut points of the first heating conductor 10 a, and the feeding conductors 13 and 14 are connected to the feeding conductors 11 and 16 via connection blocks 12 and 15, respectively. . Therefore, the feeding conductor 11, the connection block 12, the feeding conductor 13, the first heating conductor 10a, the third heating conductor 10c, the second heating conductor 10b, the fourth heating conductor 10d, and the other of the cut ones are cut. The first heating conductor 10a, the feeding conductor 14, the connection block 15, and the feeding conductor 16 are connected in series. The feeding conductors 41, 42, 11, 13, 14, 16 and the first to fourth heating conductors 10a to 10d are each composed of a square tube made of a good conductive metal.

The second heating coil circuit 82 includes the heating coil 10, the feeding conductors 11, 13, 14, 16 of the first heating coil circuit 81, and the heating coil 20 and the feeding conductor 21 respectively corresponding to the connection blocks 12, 15. , 23, 24, 26 and connection blocks 22, 25. Similarly, the third heating coil circuit 83 includes the heating coil 30, feeding conductors 31, 33, 34, 36, and connection blocks 32, 35.

The heating coils 20 and 30 respectively include the first to fourth heating conductors 20a to 20d and the first to fourth heating conductors 30a corresponding to the first to fourth heating conductors 10a to 10d of the heating coil 10, respectively. It has ~ 30d.

As shown in FIGS. 4 and 5, a magnetic core 19 is attached to the heating coil 10 so as to contact the upper surface and the inner side surface of the heating coil 10 and fill the inside of the heating coil 10. It is included. Similarly, cores (not shown) are attached to the heating coils 20 and 30. Note that 10e and 10f are the outer side surfaces of the first heating conductor 10a and the second heating conductor 10b, respectively.

As shown in FIG. 3, the power supply conductors 41, 42, the power supply conductors 11, 16, the connection blocks 12, 15, and the power supply conductors 13, 14 are respectively connected to each other via insulating plates 50, 51, 52, 53. Bonded and fixed. Further, the power feeding conductors 21, 26, the connection blocks 22, 25, and the power feeding conductors 23, 24 are coupled and fixed to each other via insulating plates 54, 55, 56, respectively. Further, the power feeding conductors 31, 36, the connection blocks 32, 35, and the power feeding conductors 33, 34 are coupled and fixed to each other via insulating plates 57, 58, 59, respectively.

Next, the circuit of the cooling liquid for the heating coil body 80 will be described. As shown in FIG. 3, the power supply conductor 41 is provided with a connection port 61 for a flexible cooling liquid supply pipe (not shown), and the power supply conductor 42 is provided for a flexible cooling liquid discharge pipe (not shown). A connection port 62 is provided. One end of the pipe 63 fixed to the outer surface of the power supply conductor 11 and the upper surface of the connection block 12 is connected to the connection port 61, and the other end is connected to the lower surface of the connection block 12 via a flexible pipe 64. It is connected to one end of a fixed pipe 65. The other end of the pipe 65 communicates with the upper end of the hollow portion of the power feeding conductor 13.

One end of the pipe 66 fixed to the lower surface of the connection block 15 is communicated with the upper end of the hollow portion of the power supply conductor 14, and the other end is connected to the upper surface of the connection block 15 via a flexible pipe 67. It is connected to the side surface of the power supply conductor 16 and one end of the pipe 68 fixedly attached to the upper surface of the connection block 22. The other end of the pipe 68 is connected via a flexible pipe 69 to one end of a pipe 70 fixed to the lower surface of the connection block 22. The other end of the pipe 70 is connected to the upper end of the hollow portion of the power supply conductor 23.

One end of the pipe 71 fixed to the lower surface of the connection block 25 communicates with the upper end of the hollow portion of the power supply conductor 24, and the other end is connected to the upper surface of the connection block 25 via the flexible pipe 72. It is connected to the side surface of the power supply conductor 31 and one end of a pipe 73 fixedly attached to the upper surface of the connection block 32. The other end of the pipe 73 is connected to one end of a pipe 75 fixed to the lower surface of the connection block 32 via a flexible pipe 74. The other end of the pipe 75 is connected to the upper end of the hollow portion of the power supply conductor 33.

One end of the pipe 76 fixed to the lower surface of the connection block 35 communicates with the upper end of the hollow portion of the power supply conductor 34, and the other end is connected to the upper surface of the connection block 35 via a flexible pipe 77. It is connected to one end of a pipe 78 fixed to the side surface of the power feeding conductor 36 and the side surface of the power feeding conductor 42. The other end of the pipe 78 is connected to the connection port 62.

Next, an induction hardening apparatus for hardening the heated surface 120 of the upper surface 111 of the work 100 using the heating coil body 80 will be described. As shown in FIG. 6, this apparatus includes a heating coil body 80, a work supporting / rotating device 150, and a jacket 160 for injecting the quenching liquid L onto the heated work 100. The work supporting and rotating device 150 includes a work receiver 152 on which the horizontally arranged work 100 is placed, a work receiving and rotating device 151 for supporting and rotating the work receiver 152, and a lower part of the work and receiving rotating device 151. And wheels 153 mounted on the rails and moving on rails 154.

The heating coils 10, 20, and 30 of the heating coil body 80 are, as shown in FIG. 1, when the work 100 placed on the work receiver 152 approaches and faces the heating coil body 80. The second heating conductor 10b of the heating coil 10, the second heating conductor 20b of the heating coil 20, and the heating coil are arranged so as to be spaced apart from each other in the circumferential direction of the heated surface 120 over substantially the half circumference of the heating surface 120. The outer surfaces 10f, 20f, 30f of each of the 30 second heating conductors 30b and the center 110 of the heated surface 120 are arranged such that the distances are R1, R2, and R3.

However, R1 <R2 <R3, and R1 is slightly smaller than the half length Rb of the inner circumference 122 of the heated surface 120, R2 is slightly larger than this length Rb, and R3 Is slightly larger than the length Rb. Therefore, the outer side surface 10e of the first heating conductor 10a of the heating coil 10 substantially coincides with the outer periphery 121 of the heated surface 120, and the outer side surface 20e of the first heating conductor 20a of the heating coil 20 corresponds to the heated surface 120. It is slightly outside the outer circumference 121, and the outer surface 30e of the first heating conductor 30a of the heating coil 30 is slightly outside the outer circumference 121 of the heated surface 120.

The size of these distances R1, R2, and R3 and the size of the width C of the heating coils 10, 20, 30 are empirically selected. In this embodiment, each of the heating coils 10, 20, and 30 is connected to the feeding conductors 13 and 14, the feeding conductors 23 and 24, and the feeding conductor 33 with respect to the cut points of the first heating conductors 10a, 20a, and 30a, respectively. , 34 are connected, so the magnetic flux decreases near this breaking point. In order to compensate for the decrease in heating near the outer circumference 121 due to the decrease in the magnetic flux, the heating coil 20 is slightly closer to the outer circumference 121 than the center of the width C of the heated surface 120, and the heating coil 30 is also The center of the width C of the heating surface 120 is closer to the outer circumference 121 than the position symmetrical with the heating coil 10.

Next, a method of quenching the heated surface 120 of the work 100 by the heating coil body 80 of this embodiment will be described. At the start of quenching, a cooling liquid is passed through the heating coil body 80. That is, when the cooling liquid is supplied to the connection port 61 in the direction of the arrow P through the cooling liquid supply pipe (not shown), the cooling liquid is supplied to the pipes 63 to 65, the power feeding conductor 13, the heating coil 10, the power feeding conductor 14, and the pipes 66 to 66. 70, the feeding conductor 23, the heating coil 20, the feeding conductor 24, the pipes 71 to 75, the feeding conductor 33, the heating coil 30, the feeding conductor 34, and the pipes 76 to 78, after cooling each feeding conductor and heating coil , Is discharged from the connection port 62 in the direction of arrow Q through a cooling liquid discharge pipe (not shown).

Next, the work 100 is placed on the work receiver 152 with the work supporting / rotating device 150 positioned substantially below the jacket 160. After that, the work supporting / rotating device 150 is moved on the rail 154 to be arranged directly below the heating coil body 80. At this time, the heating coils 10, 20, and 30 of the heating coil body 80 are arranged close to and facing the heated surface 120, as shown in FIGS. The positional relationship between the heating coils 10, 20, and 30 with respect to the heated surface 120 at this time is as described above.

Next, the work receiving device 152 is rotated by the work receiving and rotating device 151, for example, in the direction of arrow D, and the high frequency power source 90 is operated for a predetermined time. During this time, the high frequency current is supplied to the feeding conductors 41 and 11. , Connection block 12, power supply conductor 13, heating coil 10, power supply conductor 14, connection block 15, power supply conductor 16, connection block 22, power supply conductor 23, heating coil 20, power supply conductor 24, connection block 25, power supply conductor 26, connection The block 32, the power supply conductor 33, the heating coil 30, the power supply conductor 34, the connection block 35, the power supply conductor 36, and the power supply conductor 42 flow in the path or in the reverse path, and the heating coil 10 mainly heats the surface 120 to be heated. The heating coil 20 mainly heats the central portion of the heated surface 120, and the heating coil 30 mainly heats the central portion of the heated surface 120 and the peripheral portion thereof. .

As described above, since the heating coils 10, 20, and 30 are arranged at appropriate intervals in the circumferential direction of the heated surface 120, the heated surface 120 is heated by the heating coil 10. Since the heating is stopped until the lower part of the heating coil 20, the temperature is equalized, and after reaching the lower part of the heating coil 20 to be heated, the temperature is equalized again until it reaches the heating coil 30. It is heated below 30. After that, the surface to be heated 120 is cooled for about half a circumference.

When the heating of the surface to be heated 120 is completed, the work supporting and rotating device 150 is moved on the rail 154 while the work 100 is being rotated, and the work 100 is arranged below the jacket 160, and then from the jacket 160. The quenching liquid L is sprayed onto the upper surface 111 of the work 100 for a predetermined time to cool the work 100 and the quenching is completed. Finally, the rotation of the work 100 is stopped, and the work 100 is removed from the work receiver 152.

It is needless to say that a hardened layer 113 having a uniform depth is formed on the heated surface 120 thus quenched, but the periphery of the openings of the oil holes 104 to 106 and the groove 107 are obviously formed. An excessive hardened layer 113 is not formed on the periphery of the above, or a quench crack does not occur.

That is, when the heated surface 120 is heated by the conventional heating coil 200, the circumferential current is continuously concentrated on the heated surface 120 around the openings of the holes 104 to 106 and the groove 107. However, when the surface 120 to be heated is heated by the heating coil body of this embodiment, the first heating conductors 10a, 20a, 30a and the second heating conductors 10a, 20a, 30a of the respective heating coils 10, 20, 30 and the second The heating conductors 10b, 20b, and 30b cause a current to flow in the circumferential direction of the heated surface 120, but it is not continuous. In addition, since a current also flows in the radial direction by the third heating conductors 10c, 20c, 30c and the fourth heating conductors 10d, 20d, 30d, the concentration of the circumferential current around the openings of the holes 104 to 106 and the groove 107 can be prevented. is decreasing. The heating of the surface to be heated 120 is not continuous, and heating and heating stop are alternated. As a result, the occurrence of quench cracks due to overheating around the holes 104 to 106 and the groove 107 is prevented.

In the present embodiment, the case where three heating coils 10, 20, and 30 of the same shape are provided in the heating coil body has been described, but depending on the material of the work and the shape of the heated surface 120, an appropriate number of It is also possible to make some of the heating coils different in shape, or to make all the heating coils different in shape from each other so that each heating coil can exert a desired heating effect.

[0036]

[Effect of device]

 As described above, the heating coil body of the present invention is arranged so as to substantially face the annular heated surface having the predetermined width and having the groove or hole, and heats the heated surface. A heating coil body having a plurality of heating coils, wherein the heating coils are arranged at intervals in the circumferential direction of the surface to be heated over approximately half the circumference of the surface to be heated. A first heating conductor arranged substantially along the outer circumference of the heating surface, a second heating conductor arranged substantially along the inner circumference of the heated surface, one ends of the first and second heating conductors, and A third and a fourth heating conductor which are connected to each other at their other ends and are arranged substantially in the radial direction of the surface to be heated, and the heating coil is the second heating conductor of each heating coil from the center of the surface to be heated. They are arranged so that the distances to them are different from each other.

Therefore, the heating coil of the heating coil body of the present invention is arranged so as to face the surface to be heated of the rotating work, and after heating the surface to be heated, when cooling and quenching, the heating coil is heated. It is possible to prevent a hardened layer having a uniform depth from being formed on the surface, and further, to prevent an excessive hardened layer from being formed around the openings of the oil holes and the grooves, or to prevent the occurrence of quench cracks.

[Brief description of drawings]

FIG. 1 is a cross sectional view taken along the line AA of FIG.

FIG. 2 is an electric circuit diagram of a heating coil body according to an embodiment of the present invention.

FIG. 3 is a perspective view of a heating coil body according to an embodiment of the present invention.

FIG. 4 is a perspective view of one heating coil of the heating coil body according to the embodiment of the present invention.

5 is a cross sectional view taken along the line BB of FIG.

FIG. 6 is a schematic front explanatory view of an induction hardening apparatus using a heating coil body according to an embodiment of the present invention.

FIG. 7 is a front view of a work.

8 is a cross-sectional view taken along the line XX of FIG.

9 is a cross-sectional view taken along the line YY of FIG.

10 is a cross-sectional view taken along the line ZZ of FIG. 7 and a cross-sectional explanatory view of a conventional heating coil.

[Explanation of symbols]

 10, 20, 30 Heating coils 10a, 20a, 30a First heating conductors 10b, 20b, 30b Second heating conductors 10c, 20c, 30c Third heating conductors 10d, 20d, 30d Fourth heating conductor 80 Heating coil body 100 Workpiece 104 ~ 106 Oil hole 107 Groove 110 Center 120 Heated surface 121 Outer circumference 121 Inner circumference Ra, Rb Radius R1, R2, R3 Distance

Claims (2)

[Scope of utility model registration request] 1. A plurality of high-frequency heating coils, each of which has a predetermined width and is arranged so as to substantially face an annular heating surface having holes or grooves formed therein, and heats the heating surface. A high-frequency heating coil body, wherein the high-frequency heating coils are arranged at intervals in the circumferential direction of the surface to be heated over approximately half the circumference of the surface to be heated, and each high-frequency heating coil is substantially the outer periphery of the surface to be heated. A first heating conductor disposed along the first heating conductor, a second heating conductor disposed substantially along the inner circumference of the surface to be heated, and one end and the other end of the first and second heating conductors, respectively. And a third and a fourth heating conductors arranged substantially in the radial direction of the surface to be heated, and the high-frequency heating coil has a distance from the center of the surface to be heated to the second heating conductor of each heating coil with respect to each other. High frequency characterized by being arranged to be different Heating coil body. 2. The high-frequency heating coil is three of first to third high-frequency heating coils, and the first high-frequency heating coil has a substantially inner portion and a substantially central portion of the surface to be heated, and a second high-frequency heating coil. The high frequency heating coil according to claim 1, wherein the high frequency heating coil heats a substantially central portion of the heated surface, and the third high frequency heating coil heats a substantially central portion and a substantially outer portion of the heated surface. body.