JP2008261015A - Induction heating coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating coil capable of sufficiently heating a center portion of the wall thickness. <P>SOLUTION: The induction heating coil 1 heats a flange part 81 of a workpiece 80 in which the disk-shaped flange part 81 is expanded from the central axis 82, and comprises a radial part 21 which radially extends toward the outer circumferential direction from the central axis 82, an arc-shaped part 22 extending in the arc-shape by a range of a predetermined angle from the radial part 21, and a return part 23 returning from the arc-shaped part 22 to a center part side of the central axis 82. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an induction heating coil that quenches a flange surface of a workpiece, and more particularly to an induction heating coil that can sufficiently heat a central portion of a wall thickness.

As an induction heating coil for quenching a flange surface, which is a workpiece to be hardened, for example, a coil as described in Japanese Patent No. 2841169 has been proposed. FIG. 5 is a plan view showing the induction heating coil described in the publication.
The induction heating coil 100 includes a circular arc part 110 facing a quenching surface over a half circumference and a semi-open saddle type part 120 protruding from the center position of the circular arc part 110.

The arc portion 110 has a shape that connects a plurality of small arc portions 111 to 115 whose distance (radius) from the center decreases stepwise, and the semi-open saddle portion 120 is formed at the center of the arc portion 110. The semicircular portion 121 is formed, and linear portions 122 and 122 are formed in the central axis direction from both end portions of the semicircular portion 121. The arc portion 110 and the semi-open saddle portion 120 are joined to the power supply terminal plates 150 and 150 with the insulating material interposed therebetween via the L-shaped lead portion 130, and further, the water supply base 160 and the like. 160 is connected. When quenching, the arc portion 110 is opposed to the flange surface of the workpiece, and the half-open saddle portion 120 is opposed to the inner surface of the inlet portion of the shaft hole, and the induction heating coil 100 is rotated with high frequency current while rotating the workpiece. Is heated.
Japanese Patent No. 2841169

  However, the induction heating coil 100 having a shape in which the small circular arc portions 111 to 115 are stepped from the central portion to the outer periphery in this manner and the circular arc portion 110 returns from the outer periphery to the central portion via the linear portion 140 along the radius. Is not suitable for heating a conical flange portion having a thick central portion. For example, in the case of a pulley shaft (see FIG. 2) in which a shaft protrudes from the center of the pulley disk, the thickness in the vicinity of the shaft is the thickest and becomes thinner toward the outer periphery in order to increase the durability of the shaft. For this reason, the closer the hardened surface is to the center side, the greater the heat capacity, and the easier the heat is dissipated. Therefore, the small arc portion 111 cannot be heated sufficiently and is insufficiently heated.

  Therefore, in the configuration such as the induction heating coil 100, it is conceivable that the small arc portion 111 on the center side is a larger arc than the small arc portion 115 on the outer peripheral side. However, since the current mainly flows through the shortest distance in the coil, in the coil formed in a stepped manner, for example, the flow does not follow the arc as indicated by the broken line arrow in FIG. Proportional effects cannot be obtained. Furthermore, the configuration in which the small circular arc portions 111 to 115 continue in a staircase shape is complicated in shape and difficult to produce, and also causes an increase in production cost.

  Then, this invention aims at providing the induction heating coil which can fully heat the center part of thickness, in order to solve this subject.

An induction heating coil according to the present invention is for heating a flange-shaped workpiece projecting from a central axis of a disc-shaped flange, and extends in a radial direction from the central axis toward an outer peripheral direction. A shape having a radius portion, an arc portion extending in an arc shape from the radius portion by a predetermined angle range, and a return portion returning from the arc portion to the center portion side having the central axis. .
In the induction heating coil according to the present invention, the radius portion and the arc portion are formed symmetrically with respect to the central axis, and the return portion that connects the arc portions on both sides is close to the central axis. It is preferably formed so as to pass through.

In the induction heating coil according to the present invention, it is preferable that the return portion has an inner arc portion formed along the central axis in the central axis portion.
The induction heating coil according to the present invention is connected to the pair of radius portions or the radius portion and the return portion, and the pair of shaft heating portions formed along the center axis is It is preferably formed symmetrically at a position inverted by 180 °.
In addition, in the induction heating coil according to the present invention, it is preferable that the arc portion is located at a position where an inner circumference thereof overlaps with an outer circumference of the flange portion or is located outside the outer circumference.

  Therefore, according to the present invention, a flange projecting from the center axis by flowing high-frequency current through a radius part extending in the outer peripheral direction from the center axis, an arc part extending in an arc shape, and a return part returning to the center axis. Since the portion is heated, even if the center portion of the flange portion is thick, the thick portion can be sufficiently heated by the return portion in addition to the radius portion. Further, since the high-frequency current flowing from the radius portion to the arc portion and the return portion flows on the inner peripheral side which is the shortest distance, the center portion of the flange portion located on the inner peripheral side of the return portion can be sufficiently heated. it can.

Next, an embodiment of the induction heating coil according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of an induction heating coil. 2 is a cross-sectional view of the same induction heating coil shown in the AA plane of FIG. 3, and FIG. 3 is a cross-sectional view of the same induction heating coil shown in the B-B plane of FIG.
The work to be quenched by the induction heating coil 1 of the present embodiment is a pulley shaft 80 shown in FIG. The pulley shaft 80 is formed by integrally forming a pulley disk 81 and a shaft 82, and the pulley disk 81 is formed so that the wall thickness is thick at the central portion and gradually becomes thinner toward the outer peripheral direction. Yes.

  In the induction heating coil 1, a pulley heating section 10 is formed along the to-be-quenched surface W as a heating conductor for heating the to-be-quenched surface W of the pulley disk 81. The induction heating coil 1 is further formed with linear shaft heating portions 11 and 11 extending in the axial direction from the pulley heating portion 10 with the shaft 82 interposed therebetween, and an overhang portion 12 projecting in parallel. A pair of lead portions 13 and 13 are fixed to the overhanging portion 12 and the one shaft heating portion 11, and are joined to the superposed power supply terminal plates 14 and 14 with an insulating material interposed therebetween, and a water supply base. 15 and 15 are connected.

  The pulley heating unit 10 of the induction heating coil 1 is formed as shown in FIG. That is, the radial portions 21 and 21 extend in the radial direction from the base portion of the shaft 82 at the center of the pulley disk 81, and are connected to the arc portions 22 and 22 along the outer periphery of the pulley disk 81. The radius portion 21 and the arc portion 22 are configured symmetrically with the shaft 82 interposed therebetween, and a pair of radius portions 21 and 21 are arranged on a straight line. And it is connected by the straight return part 23 extended in parallel with the radius parts 21 and 21 so that it may return from the circular arc parts 22 and 22 to the center part side. In particular, the return portion 23 is disposed so as to pass through a position close to the central shaft 82 as shown in the figure.

  As described above, the pulley heating unit 10 is formed in the shape shown in the drawing including the radius portions 21 and 21, the arc portions 22 and 22, and the return portion 23. When the pulley heating unit 10 is viewed from the side as shown in FIG. 2, the hardened surface W of the pulley disk 81 in which each of the radius part 21, the arc part 22, and the return part 23 is formed in a conical shape. It is formed so as to keep a certain distance along. Further, a circumferential recess 83 is formed at the base of the shaft 82, and the jaw portion 25 projects from the radius portion 21 and the return portion 23 so that the pulley heating portion 1 can sufficiently quench the recess 83. It is installed.

  The pulley heating unit 10 thus formed is connected to shaft heating units 11 and 11 for heating the shaft 82. The pair of shaft heating portions 11, 11 are coupled to the radius portions 21, 21 and are formed symmetrically with the shaft 82 interposed therebetween. The shaft heating unit 11 that is far from the lead unit 13 is connected to the shaft 13 through the overhanging unit 12. The overhanging portion 12 is formed so as to pass through a position away from the tip of the shaft 82 so as not to heat the shaft 82 excessively.

  The induction heating coil 1 includes a region surrounded by the pulley heating unit 10 and the overhanging unit 12, and the pulley shaft 80 is inserted from the direction of arrow S shown in FIG. Therefore, in order to insert the shaft 82, for example, the pair of radius portions 21 and 21 shown in FIG. 3 is inclined so that the arc portions 22 and 22 are lowered to the lower side of the drawing (to be in a C shape). If so, the interval between the shaft heating portions 11 and 11 shown in FIG. Therefore, in the present embodiment, the extending angle at which the radius portions 21 and 21 are arranged on a straight line is formed at 180 °.

  Therefore, the pulley shaft 80 moves up in the direction of arrow S shown in FIG. 3 in a standing state as shown in FIG. 2 so that the shaft 82 enters between the shaft heating portions 11 and 11, so that the induction heating coil 1 is moved. Placed against. And the pulley disk 81 is arrange | positioned adjacently under the pulley heating part 10, as shown in FIG. The pulley shaft 80 is quenched in such a state, and is rotated about the shaft 82 as a rotation axis, and a high-frequency current is passed through the induction heating coil 1.

  Thereby, about the pulley shaft 80, the to-be-quenched surface W of the pulley disk 81 and the shaft 82 are heated. And the pulley shaft 80 is taken out from the induction heating coil 1 after predetermined | prescribed heating, and a cooling fluid is sprayed on the heated hardening surface. A hardened layer is formed on the workpiece surface by rapidly cooling the heated portion with such cooling water.

  Therefore, according to the induction heating coil 1 of the present embodiment, the radius portions 21 and 21 extending from the shaft 82 and the return portion 23 passing through the position approaching the shaft 82 are the central portion of the pulley disk 81 having a flange shape. As a result, the thick central portion can be sufficiently heated. Since the current mainly flows through the shortest distance of the coil, the high-frequency current flows in the return portion 23 on the inner side facing the shaft 82. Therefore, the central portion of the thick pulley disk 81 is sufficiently heated also in this respect. I was able to do that. Further, since the pulley heating unit 10 has a symmetrical shape with the shaft 82 interposed therebetween, the hardened surface W of the rotating pulley disk 81 passes through the same heating unit twice for each rotation, so that efficient heating is achieved. Is done.

  In the pulley heating unit 10, jaw portions 25 are respectively provided on the radius portion 21 and the return portion 23, and the concave portion 83 formed at the base of the shaft 82 can be sufficiently heated. Further, in the induction heating coil 1, since the extending angles of the radius portions 21 and 21 are 180 ° and the work entrance is wide, the pulley shaft 80 inserted from the direction of arrow S in FIG. 3 can be easily inserted. It has become. Furthermore, the pulley heating unit 10 includes a radius part 21, an arc part 22, and a return part 23, and is simple in shape because it has many straight lines. In this respect, the cost can be reduced. Such a simple shape is also a shape that eliminates an extra corner shape that does not allow a current to flow through the shortest distance. In addition, since it has a simple shape, it has an effect that a heating promoting core can be easily attached, and thus heat adjustment is easy.

  Next, a second embodiment of the induction heating coil will be described. FIG. 4 is a view showing the induction heating coil of the present embodiment, and corresponds to FIG. 3 of the first embodiment. That is, the induction heating coil 2 of the present embodiment is for quenching the pulley shaft 80 and changing the pulley heating unit 10 of the induction heating coil 1. Therefore, the induction heating coil 2 is the same as the shaft heating units 11 and 11, the overhanging unit 12, the lead units 13 and 13, the terminal plates 14 and 14, and the caps 15 and 15 shown in FIG. 1 except for the pulley heating unit 30. It is configured.

  The pulley heating unit 30 of the induction heating coil 2 is formed in a shape as shown in FIG. That is, the radius portion 31 extends in the radial direction from the shaft 82 at the center of the pulley disk 81 and is connected to the arc portion 32 along the outer periphery of the pulley disk 81. From the arc portion 32, a return portion 33 that returns to the center portion side substantially extends in parallel with the radius portion 31, and an inner arc portion 33 a that is curved along the side surface of the shaft 82 is formed at the center portion. The inner arc portion 33 a is connected to the shaft heating portion 11 opposite to the radius portion 31. In addition, the radial portion 31 and the inner circular arc portion 33a are respectively formed with jaw portions 35 protruding in the center direction.

  Thus, the pulley heating part 30 is formed in the shape which consists of the return part 33 which has the radius part 31, the circular arc part 32, and the inner side arc part 33a, and the pulley disk 81 is the same as that of 1st Embodiment shown in FIG. It is formed so as to maintain a certain distance along the to-be-quenched surface W. And the induction heating coil 2 comprises the area | region enclosed by this pulley heating part 30 grade | etc., And the pulley shaft 80 is inserted from the arrow S direction. For this reason, the shaft heating sections 11 and 11 are formed symmetrically at positions that are inverted by 180 ° with respect to the central axis so as not to narrow the interval, as in the first embodiment.

  Therefore, in this embodiment, the pulley shaft 80 is installed with respect to the induction heating coil 2 as shown in FIG. Thereafter, the pulley shaft 80 is rotated about the shaft 82 as a rotation axis, and a high-frequency current is passed through the induction heating coil 2. Thereby, the hardening surface W of the pulley disk 81 and the pulley shaft 80 are heated about the pulley shaft 80. And the pulley shaft 80 is taken out from the induction heating coil 2, and a cooling fluid is sprayed on the heated hardening surface. A hardened layer is formed on the workpiece surface by rapidly cooling the heated portion with such cooling water.

  Therefore, according to the induction heating coil 2 of the present embodiment, not only the radius portion 31 extending from the shaft 82 but also the center portion of the flange shape is heated by the inner arc portion 33a positioned around the shaft 82, so The central portion of the thick pulley disk 81 can be sufficiently heated. And since the high frequency current which flows through the shortest distance of a coil flows through the inner peripheral side of the inner side arc part 33a, it became possible to fully heat the center part of the thick pulley disk 81. FIG. Further, the pulley heating portion 30 has a jaw portion 35 projecting from the radius portion 31 and the inner circular arc portion 33a, respectively, so that the pulley heating portion 30 is sufficiently provided for a recess 83 (see FIG. 2) formed at the base of the shaft 82. Can be heated.

  Since the induction heating coil 2 is in a position where the shaft heating units 11 and 11 are open and the workpiece entrance is wide, the pulley shaft 80 inserted from the direction of arrow S in FIG. 4 can be easily inserted. Furthermore, since the pulley heating unit 30 has a simple shape including the return portion 33 having the radius portion 31, the arc portion 32, and the inner arc portion 33a, it can be easily manufactured, and the cost can be reduced in this respect. And this simple shape is also the shape which eliminated the extra corner | angular part shape which the electric current which passes through the shortest distance does not flow. In addition, since it has a simple shape, it has an effect that a heating promoting core can be easily attached, and thus heat adjustment is easy.

  By the way, in 1st and 2nd embodiment, the circular arc parts 22 and 32 of the pulley heating parts 10 and 30 are formed so that it may overlap with the outer periphery of the pulley disk 81, as shown in FIG.3 and FIG.4. However, for example, the configuration may be such that the positions of the arc portions 22 and 32 are further moved outward in the radial direction, and the inner circumferences 22a and 32a overlap the outer circumference of the pulley disk 81 or further outside. This is because the current flows on the inner circumferences 22a and 32a side where the shortest distance is reached, so that the outermost circumference of the pulley disk 81 can be further heated.

As mentioned above, although embodiment was demonstrated about the induction heating coil of this invention, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the pulley heating units 10 and 30 of the above embodiment, the shapes of the radius portions 21 and 32 and the return portions 23 and 33 are straight in the plan views shown in FIGS. There may be.

It is the perspective view which showed the induction heating coil of 1st Embodiment. It is sectional drawing shown by the AA surface of FIG. 3 about the induction heating coil of 1st Embodiment. It is sectional drawing shown by the BB surface of FIG. 2 about the induction heating coil of 1st Embodiment. It is the figure which showed the heating part about the induction heating coil of 2nd Embodiment. It is the figure which showed the conventional induction heating coil.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Induction heating coil 10 Pulley heating part 11 Shaft heating part 12 Overhang | projection part 13 Lead part 14 Terminal board 15 Base 21 Radial part 22 Arc part 23 Return part 80 Pulley shuff 81 Pulley disk 82 Shaft

Claims (5)

In an induction heating coil for heating the flange part of a workpiece with a disk-shaped flange part protruding from the central axis,
A radial portion extending radially from the central axis toward the outer circumferential direction, an arc portion extending in an arc shape from the radial portion by a predetermined angle range, and returning from the arc portion to the central portion side where the central axis is located An induction heating coil characterized by having a shape with a portion. In the induction heating coil according to claim 1,
The radius part and the arc part are formed symmetrically with respect to the central axis, and the return part that connects the arc parts on both sides passes through a position close to the central axis. An induction heating coil characterized by being. In the induction heating coil according to claim 1,
The induction heating coil according to claim 1, wherein the return portion has an inner arc portion formed along the central axis in the central axis portion. In the induction heating coil according to any one of claims 1 to 3,
The pair of shaft heating portions connected to the pair of radius portions or the radius portion and the return portion and formed along the central axis are symmetrically formed at positions inverted by 180 ° with respect to the central axis. An induction heating coil characterized by being made. In the induction heating coil according to any one of claims 1 to 4,
The induction heating coil, wherein the arc portion is located at a position where an inner circumference thereof overlaps with an outer circumference of the flange portion, or is located outside the outer circumference.

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