JP5887161B2 - Heating coil and heating device provided with the same - Google Patents

Description

  The present invention relates to a heating coil that heats a heated portion in order to quench a workpiece such as a machine part, and a heating device including the heating coil.

  A heating coil is used to heat a heated part of a machine part for the purpose of improving the hardness of a nut having an inner peripheral surface formed with an internal thread and other machine parts.

As this heating coil, a space for passing cooling water is formed continuously inside, and a heating coil is provided with a linear heating conductor facing the heated part, and this heating conductor is connected to a power source such as a high-frequency transformer. Is known (Patent Document 1). In the heating coil shown in Patent Document 1, the heating conductor is formed in a square pipe shape.
Conventionally, there is also known a heating coil provided with a spiral head portion that is disposed so as to face the heated portion and is disposed along the axial direction of the workpiece (Patent Document 2).

JP 2001-172716 A Japanese Utility Model Publication No. 63-192455

  However, in the conventional heating coil as described in Patent Document 1, since the heating conductor portion of the heating coil is in the shape of a square pipe, it can be easily estimated that the cross-sectional shape is a rectangle having a certain thickness. Therefore, the area of the heating coil facing the inner peripheral surface of the nut is small, the inner peripheral surface of the nut cannot be efficiently heated by the heating coil, and it takes time to heat the inner peripheral surface of the nut.

  Moreover, in the conventional heating coil as described in Patent Document 2, because the adjacent tubes among the helical tubes constituting the head portion are arranged at a predetermined interval in the extending direction of the heated portion, The area through which the cooling water passes is small and high power cannot be input to the heating coil. For this reason, if the workpiece is heated when the workpiece is thin, the efficiency is poor and heating takes time, and heat is transmitted to the entire thin workpiece so that only the heated portion cannot be heated.

  An object of the present invention is to provide a heating coil that can efficiently heat a heated portion in a short time and can cope with a thin workpiece and a heating device including the heating coil.

The heating coil of the present invention is a heating coil having a space in which a heated portion is a work that is an inner peripheral surface in which irregularities are formed along the axial direction, and has a space formed continuously inside to allow a cooling medium to pass therethrough. A first linear portion and a second linear portion that respectively oppose the heated portion, a connecting portion that connects the tips of the first linear portion and the second linear portion, the first linear portion and the second linear portion. A pair of connecting parts, one end of which is connected to the base end side of each part, the first straight line part and the second straight line part are parallel to each other, and each is divided into an outer peripheral part and an inner peripheral part The cross section is formed so that the outer peripheral portion facing the inner peripheral surface of the heated portion protrudes along the inner peripheral surface of the heated portion, the central portion is thick, and both side portions of the outer peripheral portion are It is thin.

In the present invention with this configuration, the rectangular cross section defined by the outer peripheral portion and the inner peripheral portion in the first straight portion and the second straight portion is thick at the center of the outer peripheral portion facing the heated portion. Since both sides are thin, the outer peripheral surfaces of the first straight line part and the second straight line part have a small difference in the distance between the heated part over the circumferential direction, and the first straight line part and the second straight line facing the heated part The outer peripheral area of the straight portion, that is, the area of the heating coil facing the heated portion is increased. Therefore, the heated part can be efficiently heated by the heating coil, and the heated part can be heated in a short time.
In addition, since a space through which the cooling medium passes is formed and the first straight portion and the second straight portion that face the heated portion are provided, the area through which the cooling medium passes can be increased, and high output can be input to the heating coil. Therefore, even if the workpiece, which is the inner peripheral surface with unevenness along the axial direction, is thin, the thin workpiece can be heated efficiently and in a short time, and heat is transferred to the entire thin workpiece. It is possible to heat only the heated part.

In the present invention, it is preferable that the connecting portion has a linear shape.
In this invention of this structure, since a connection part is a linear shape, the structure of a heating coil can be simplified.

In the present invention, it is preferable that the connecting portion has a curved shape.
In the present invention having this configuration, since the connecting portion has a curved shape, for example, when the heating coil is moved relative to the workpiece in the circumferential direction, the connecting portion causes, for example, the bottom portion of the heated portion to face the connecting portion. Can also be heated.

The heating device of the present invention includes the above-described heating coil and a moving mechanism that moves the workpiece relative to the heating coil, and the moving mechanism moves the heating coil and the workpiece axially and circumferentially. It is possible to move relative to each direction.
In the present invention having this configuration, since the moving mechanism for moving the workpiece relative to the heating coil is provided, the heating coil and the workpiece can be moved relative to each other in the axial direction and the circumferential direction. There is no heating unevenness and the heated portion can be reliably heated by the heating coil.

Sectional drawing which shows the heating apparatus which concerns on 1st Embodiment of this invention. The perspective view which shows the heating coil which concerns on 1st Embodiment of this invention. The side view which shows the heating coil which concerns on 1st Embodiment of this invention. Sectional drawing in the IV-IV line of FIG. Sectional drawing which shows the heating apparatus which concerns on 2nd Embodiment of this invention. The perspective view which shows the heating coil which concerns on 2nd Embodiment of this invention.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings.
In each embodiment, the same reference numerals are given to the same components, and descriptions thereof are omitted or simplified.

<First Embodiment>
FIG. 1 shows the entire heating device 1, and FIG. 2 shows the entire heating coil.
In FIG. 1, the heating apparatus 1 of the present embodiment is for induction-quenching a nut W as a workpiece. The nut W is used as a part for an automobile, and a female screw portion (not shown) as an unevenness is formed along the axial direction (vertical direction in FIG. 1). This female screw portion has an inner peripheral surface W1 as a heated portion. The female screw is mainly formed in the upper part W10 of the inner peripheral surface W1, and the inner peripheral surface W1 is heated by the heating device 1 to quench the portion where the female screw is formed.

  The heating device 1 is provided with a heating coil 2 having an outer shape, a forward / backward mechanism (not shown) for moving the heating coil 2 in the axial direction of the heating coil 2 relative to the nut W, and a nut W. A rotary table 3 that rotates a nut W with respect to the coil 2 is provided. The advance / retreat mechanism and the rotary table 3 constitute a moving mechanism of the present embodiment.

  As shown in FIGS. 1 and 2, the heating coil 2 includes a first straight portion 21 and a second straight portion 22 that face the inner circumferential surface W <b> 1, and tips of the first straight portion 21 and the second straight portion 22. (A lower end portion in FIG. 1) A pair of connecting portions 23 that connect each other, and a pair of connection portions whose one ends are respectively connected to the base end sides (upper side in FIG. 1) of the first straight portion 21 and the second straight portion 22. 24, 24 and a pair of linear bases 25, 25 having one end connected to the other end side (the upper side in FIG. 1) of the connection portions 24, 24 and the other end connected to a power source (not shown) such as a high frequency transformer, And a flow path 26 is continuously formed as a space through which a cooling medium, for example, cooling water passes.

As shown in FIG. 1, each base portion 25 has an outer peripheral portion 251 and a rectangular inner peripheral portion 252. A rectangular lead plate 40 (see FIG. 3) is attached to one base portion 25. The lead plate 40 is connected to a power source via one base portion 25.
As shown in FIG. 1, each of the connecting portions 24 has an outer peripheral portion 241 and a rectangular inner peripheral portion 242, and one end of one connecting portion 24 is larger than 90 ° and smaller than 180 ° with the first straight portion 21. One end of the other connecting portion 24 is connected to the second linear portion 22 at an angle α2 that is greater than 90 ° and smaller than 180 °.
Further, the outer peripheral portion 241 of the connecting portion 24 is connected to the outer peripheral portion 251 of the base portion 25, and the inner peripheral portion 242 of the connecting portion 24 is connected to the inner peripheral portion 252 of the base portion 25.

As shown in FIGS. 1 and 4, the first straight part 21 has an outer peripheral part 211 and a rectangular inner peripheral part 212. The outer peripheral portion 211 of the first straight portion 21 is connected to the outer peripheral portion 241 of the one connecting portion 24, and the inner peripheral portion 212 of the first straight portion 21 is connected to the inner peripheral portion 242 of the one connecting portion 24.
As shown in FIG. 4, the cross-sectional shape divided by the outer peripheral portion 211 and the inner peripheral portion 212 has a thick central portion 201 of the outer peripheral portion 211 facing the inner peripheral surface W <b> 1 and both side portions 202 of the outer peripheral portion 211. , 202 is thin. That is, the cross section of the flow path 26 is rectangular, and the outer peripheral portion 211 facing the inner peripheral surface W1 is formed in an arc shape along the shape of the inner peripheral surface W1.

Similarly to the first straight line portion 21, the second straight line portion 22 has an outer peripheral portion 221 and a rectangular inner peripheral portion 222, and is parallel to the first straight line portion 21. The outer peripheral portion 221 of the second straight portion 22 is connected to the outer peripheral portion 241 of the other connecting portion 24, and the inner peripheral portion 222 of the second straight portion 22 is connected to the inner peripheral portion 242 of the other connecting portion 24.
As shown in FIG. 4, the cross-sectional shape defined by the outer peripheral portion 221 and the inner peripheral portion 222 is thick at the central portion 203 of the outer peripheral portion 221 facing the inner peripheral surface W1, as in the first linear portion 21. Both side portions 204 and 204 of the outer peripheral portion 221 are thin. That is, the outer peripheral portion 221 facing the inner peripheral surface W1 is formed in an arc shape along the shape of the inner peripheral surface W1. In addition, the other outer peripheral parts 241 and 251 are formed in the circular arc shape connected with the external shape of the outer peripheral parts 211 and 221.
As shown by an imaginary line in FIG. 4, a pair of cores 27, 27 for confining magnetic flux is sandwiched between the first straight portion 21 and the second straight portion 22. The core 27 has a bulging portion 271 that covers the connecting portion between the outer peripheral portion 211 and the inner peripheral portion 212 and the connecting portion between the outer peripheral portion 221 and the inner peripheral portion 222 from the outside of the first straight portion 21 and the second straight portion 22. . Note that the shape and size of the core are not limited to this, and any shape and size of the core can be used as long as the core can be disposed within the imaginary line within the range indicated by the imaginary line in FIG.

  As shown in FIGS. 1 and 3, the connecting portion 23 has a linear shape, and includes an outer peripheral portion 231 and a rectangular inner peripheral portion 232. The outer peripheral portion 231 connects the tips of the outer peripheral portion 211 of the first linear portion 21 and the outer peripheral portion 221 of the second linear portion 22, and the inner peripheral portion 232 is connected to the inner peripheral portion 212 of the first linear portion 21 and the second straight line. The tips of the portion 22 and the inner peripheral portion 222 are connected to each other.

  As shown in FIG. 1, the flow channel 26 has a hairpin shape as a whole and is rectangular in cross-sectional view (see FIG. 3). The first straight portion 21, the second straight portion 22, the connecting portion 23, the connecting portion 24, and the base portion 25 is formed inside. The upper end of the flow path 26 in FIG. 1 is connected to a cooling medium supply source (not shown), and when the inner peripheral surface W1 is quenched, the cooling medium that cools the inside of the heating coil 2 is supplied from the cooling medium supply source to the inside of the flow path 26. To be supplied.

Next, a method for quenching the inner peripheral surface W1 using the heating device 1 will be described.
First, the nut W is placed and fixed on the rotary table 3. Next, the heating coil 2 is moved downward in FIG. 1 by the advance / retreat mechanism to enter the inside of the nut W, and the first straight portion 21 and the second straight portion 22 are formed on the inner peripheral surface W1, particularly the portion where the female screw is formed. Face each other.

And while supplying the cooling medium from a cooling-medium supply source in the flow path 26, the 1st linear part 21, the 2nd linear part 22, the connection part 23, the connection part 24, and the base 25 via the lead plate 40 from a power supply. A high-frequency current is passed through. If it does so, magnetic flux will generate | occur | produce and heat will generate | occur | produce from the 1st linear part 21 and the 2nd linear part 22, and the internal peripheral surface W1 will be heated by this heat. Thereby, the internal thread portion is continuously heated.
Further, when the rotary table 3 is rotated and the nut W is rotated with respect to the heating coil 2, the entire circumferential surface of the inner circumferential surface W1 is heated, and the inner circumferential surface W1 is quenched.

Therefore, in this embodiment, the following effects can be obtained.
(1) In the heating coil 2 of the present embodiment, in the cross section defined by the outer peripheral portion 211 and the inner peripheral portion 212 of the first linear portion 21, the central portion 201 of the outer peripheral portion 211 facing the inner peripheral surface W1 is thick. Both side portions 202, 202 of the outer peripheral portion 211 are thin. Further, the cross section defined by the outer peripheral portion 221 and the inner peripheral portion 222 of the second straight portion 22 is also thick at the center portion 203 of the outer peripheral portion 221 facing the inner peripheral surface W1, and both side portions 204 of the outer peripheral portion 221. 204 are thin. For this reason, the difference in the distance between the outer peripheral surfaces of the first linear portion 21 and the second linear portion 22 in the circumferential direction and the inner peripheral surface W1 is reduced, and the first linear portion 21 and the second straight line facing the inner peripheral surface W1. The outer peripheral area of the part 22, that is, the area of the heating coil 2 facing the inner peripheral surface W1 is increased. Therefore, the inner peripheral surface W1 can be efficiently heated by the heating coil 2, and the inner peripheral surface W1 can be heated in a short time.

(2) Further, since the first straight portion 21 and the second straight portion 22 respectively facing the inner peripheral surface W1 are provided, and the flow path 26 is formed inside the first straight portion 21 and the second straight portion 22, The area through which the cooling medium passes can be increased, and a high output can be input to the heating coil 2. Therefore, the thin nut W in which the internal thread is formed on the inner peripheral surface W1 can be efficiently heated in a short time, heat is not transmitted to the entire nut W, and only the inner peripheral surface W1 can be heated.

(3) Since the connecting portion 23 has a linear shape, the structure of the heating coil 2 can be simplified.
(4) One connecting portion 24 is connected to the first straight portion 21 at an angle α1 larger than 90 ° and smaller than 180 °, and the other connecting portion 24 is connected to the second straight portion 22 larger than 90 ° and smaller than 180 °. Since the connection is made at the angle α2, the resistance caused by the shape of the flow path 26 inside the connection portion 24 compared to the case where the connection portion is connected to the first straight portion and the second straight portion at 90 ° as in the prior art. The cooling medium is easy to pass through the flow path 26.

(5) Since the pair of cores 27 and 27 for confining the magnetic flux inside are provided, the first straight portion 21 and the second straight portion 22 can be reliably heated using the confined magnetic flux, and the outer diameter is Even the small nut W can be efficiently heated by the heating coil 2.

(6) The heating device 1 of the present embodiment includes the heating coil 2, an advancing / retracting mechanism (not shown) that moves the heating coil 2 in the axial direction of the heating coil 2, and the rotary table 3. And the inner peripheral surface W1 can be moved relative to each other in the axial direction and the circumferential direction, there is no uneven heating on the inner peripheral surface W1, and the inner peripheral surface W1 can be reliably heated by the heating coil 2.

Second Embodiment
Next, a second embodiment of the present invention will be described.
As shown in FIGS. 5 and 6, in the heating device 1 </ b> A and the heating coil 2 </ b> A of this embodiment, unlike the first embodiment, the connecting portion 23 has a curved shape, and the first straight portion 21 and the second straight portion 22 It is provided so as to protrude and straddle between the first straight part 21 and the second straight part 22.
In such a heating coil 2A of the present embodiment, the same effects (1) to (6) as in the first embodiment are exhibited, and the connecting portion 23 has a curved shape. Therefore, the rotary table 3 is rotated. When the nut W is rotated with respect to the heating coil 2A, the bottom portion W11 of the inner peripheral surface W1 can also be heated by the connecting portion 23.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the nut W having the inner peripheral surface W1 in which the female screw is formed is used as the work. However, if the machine part has the inner peripheral surface in which the unevenness is formed in the axial direction, Mechanical parts other than nuts may be used. Moreover, in the said embodiment, although the internal thread was mainly formed in the upper part W10 of the internal peripheral surface W1, you may form in the whole side surface of the internal peripheral surface W1.

  INDUSTRIAL APPLICATION This invention can be utilized as a heating coil which heats a to-be-heated part in order to quench workpieces, such as a machine part, and a heating apparatus provided with the same.

  DESCRIPTION OF SYMBOLS 1,1A ... Heating device, 2, 2A ... Heating coil, 3 ... Rotary table (movement mechanism), 21 ... First straight part, 22 ... Second straight part, 23 ... Connection part, 24 ... Connection part, 26 ... Flow path (Space), 201, 203 ... center, 202, 204 ... both sides, 211, 221 ... outer periphery, 212, 222 ... inner periphery, W ... nut (workpiece), W1 ... inner periphery (heated portion)

Claims (4)

A heating coil that heats a work that is an inner peripheral surface in which irregularities are formed along an axial direction of a heated portion, and has a space that is continuously formed inside and allows a cooling medium to pass therethrough,
A first straight portion and a second straight portion respectively facing the heated portion;
A connecting portion that connects the tips of the first straight portion and the second straight portion;
A pair of connection parts each having one end connected to the base end side of the first straight part and the second straight part;
The first straight portion and the second straight portion are parallel to each other, and each of the cross sections defined by the outer peripheral portion and the inner peripheral portion has an outer peripheral portion facing the inner peripheral surface of the heated portion. A heating coil, wherein the heating coil is formed so as to protrude along the inner peripheral surface of the heating portion, the central portion is thick, and both side portions of the outer peripheral portion are thin. The heating coil according to claim 1, wherein
The connecting portion has a linear shape. The heating coil according to claim 1, wherein
The connecting portion has a curved shape. A heating coil according to any one of claims 1 to 3,
A moving mechanism for moving the work relative to the heating coil;
This moving mechanism enables the said heating coil and the said workpiece | work to move relatively to an axial direction and the circumferential direction, respectively. The heating apparatus characterized by the above-mentioned.

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