JP5430180B2 - Induction hardening coil device - Google Patents

Description

  The present invention relates to a coil apparatus for induction hardening used when, for example, a shaft-like workpiece having a flange at the end of a shaft such as a turbine shaft is quenched by high-frequency induction heating.

Generally, a turbine shaft for a turbocharger has a shaft portion having a predetermined length, and a flange portion having a predetermined shape that can be fitted into a wheel fitting hole at an end portion of the shaft portion and is larger in diameter than the shaft portion. Are integrally formed. Conventionally, when quenching such a shaft portion of a turbine shaft, a coil device 51 as shown in FIG. 9 is used. The coil device 51 has a predetermined thickness, a cooling water flow path 52b formed therein, and a plane having a work insertion hole 52a through which the shaft portion Wa of the turbine shaft W can be inserted with a predetermined gap at the center. A coil portion 52 having a substantially annular shape in view, and a silicon plywood 53 and the like that are fixed to the lower surface side (the flange portion Wb side of the turbine shaft W) in the drawing of the coil portion 52 to block the magnetic flux.

  Then, both ends of the coil unit 52 are electrically connected to a high-frequency current generator such as a transistor inverter through a holder or the like, and a high-frequency current of a predetermined frequency is supplied to the coil unit 52, thereby generating from the coil unit 52. An eddy current is induced in the shaft portion Wa by the generated magnetic flux, and the shaft portion Wa is induction-heated. In addition, after induction heating, the cooling water is injected from the cooling water flow path 52b connected to the cooling water supply device through the injection holes 52c provided in the coil portion 52 toward the shaft portion Wa and the flange portion Wb as shown by the arrow a. By doing so, the shaft portion Wa is rapidly cooled and quenched. As a coil device for quenching a small-diameter workpiece, there is, for example, Patent Document 1.

JP 7-258725 A

  However, in such a coil device 51, the coil portion 52 has a substantially disk shape, and the injection hole 52c provided at the lower end edge of the inner surface of the workpiece insertion hole 52a has a boundary portion between the shaft portion Wa and the flange portion Wb (end surface of the shaft portion). 9), when cooling water is injected as shown by the arrow A in FIG. 9 during cooling after induction heating, the cooling water abuts against the shaft portion Wa and the flange portion Wb by the momentum, etc. Cooling water is easily scattered. Therefore, the scattered cooling water adheres to the quenching device attached to the coil device 51, and the quenching device is soiled to make the cleaning work cumbersome, and it is necessary to enlarge the scattering prevention cover of the quenching device, for example. The configuration of the quenching device is likely to be complicated.

  Further, since the opening edge of the injection hole 52c is located on the flange Wb, even if the injection of the cooling water is stopped after the cooling is completed, the remaining remaining in the cooling water flow path 52b of the coil part 52 is left. Water may drop on and adhere to the flange Wb from the injection hole 52c as indicated by an arrow B in FIG. 9 to adversely affect the quenching quality of the shaft end face Wc. Further, since the lower end edge of the workpiece insertion hole 52a of the coil portion 52 is an inclined surface because it is necessary to provide the injection hole 52c, the coil portion 52 cannot be brought closer to the shaft end surface Wc by a predetermined distance or more, and the shaft end surface It is difficult to quench to the limit of Wc. Accordingly, it is difficult to obtain a high-quality and stable quenching state on the shaft end face Wc. Furthermore, when quenching the shaft end face Wc, it is necessary to provide the silicon plywood 53 in order to prevent quenching of the flange portion Wb. Therefore, the number of members increases and the cost of the coil device 51 is likely to increase.

  The present invention has been made in view of such circumstances, and an object of the present invention is to disperse cooling water by providing a convex portion on the edge of the workpiece insertion hole and providing an injection hole on the outer peripheral side of the convex portion. To provide a coil apparatus for induction hardening that can stably obtain a high-quality quenching state on the end surface of the shaft portion of the shaft-like work, for example, by suppressing the adhesion of residual water to the work while restraining is there.

In order to achieve this object, the invention according to claim 1 of the present invention includes a coil portion having a work insertion hole in the center portion and formed in a substantially annular shape in plan view, and both end portions of the coil portion. A coil device for induction hardening capable of hardening a shaft-like workpiece with a holder that can be supported and connected to a high-frequency current generator, wherein the coil portion is formed on a surface of the coil portion at an edge of the workpiece insertion hole. An annular projection protruding to the side is formed, and an injection hole is provided on the outside of the projection that can inject cooling water in the cooling water flow path provided in the coil portion into the quenching portion of the shaft-like workpiece , The injection hole is provided outside the outer peripheral edge of the flange portion of the shaft-shaped workpiece having the shaft portion and the flange portion .

The invention according to claim 2, together with the inner surface of the workpiece insertion hole of said coil portion the convex portion is formed in a tapered face as a small diameter, an outer surface of said convex portion projecting direction side becomes smaller in diameter It is formed with a tapered surface.

  According to the invention described in claim 1 of the present invention, an annular convex portion projecting to the surface side of the coil portion is formed at the edge of the work insertion hole of the coil portion, and the outside of the convex portion. Since the injection hole that can inject the cooling water in the coil part into the quenching part of the shaft-like work is provided, the convex part can be brought close to the end of the shaft part end face of the shaft-like work. The end face can be effectively quenched, and the splashing of the cooling water can be suppressed by the convex portion, so that a high-quality quenching state can be stably obtained for the shaft-like workpiece.

In addition, since the injection hole is provided outside the outer peripheral edge of the shaft part of the shaft-like workpiece, the residual water in the coil portion will not drop on the collar portion of the shaft-like workpiece after quenching, A higher quality quenching state can be obtained on the end face of the shaft portion of the shaft workpiece.

Further, according to the invention described in claim 2, in addition to the effect of the invention described in claim 1 , since the inner surface of the workpiece insertion hole of the coil portion and the outer surface of the convex portion are formed as tapered surfaces, the workpiece insertion The taper surface on the inner surface of the hole can easily insert the shaft-like workpiece into the insertion hole, and the tapered surface of the convex portion can prevent the adverse effect on the cooling water injection state.

The top view of the coil apparatus for induction hardening concerning this invention Same side view The back view Top view of the coil Bottom view of the coil Front view of the coil Same half sectional view Illustration of the quenching condition Illustration of conventional quenching condition

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
1 to 8 show an embodiment of a coil apparatus for induction hardening according to the present invention. As shown in FIGS. 1 to 3, the coil device 1 includes a holder 2 and a coil portion 3 supported by the holder 2 by being attached to the tip of the holder 2.

  The holder 2 is formed in a substantially strip-like plate shape when viewed from the side by fixing a pair of copper plates 4 with an insulating bushing bolt 6 via an insulating plate 5, and an upper portion on the tip side thereof is notched. Is formed in a substantially triangular shape in side view. A terminal plate 7 made of a copper plate thicker than the copper plate 4 is brazed to the rear end portion of the holder 2 at a right angle to the outside. Further, copper square pipes 8 are brazed and fixed to the outer surfaces of the pair of copper plates 4 along the longitudinal direction thereof, and both ends of the coil portion 3 are connected to the ends of the square pipes 8. .

  The rear end of each square pipe 8 is fixed to the surface of the terminal plate 7 by brazing and communicates with one end of a cooling water passage (not shown) provided in the terminal plate 7, and the other end of the cooling water passage is a terminal. An opening is formed on the upper surface of the plate 7, and one end of a copper round pipe 9 is fixed to the opening by brazing. A hose connector 10 is fixed to the other end of the round pipe 9 by brazing. A cooling water circulation path is formed in the holder 2 by the pair of square pipes 8, the cooling water flow path of the terminal plate 7, the round pipe 9 and the hose connector 10.

  As shown in FIGS. 4 to 7, the coil portion 3 has a thickness t <b> 1 (e.g., 8 mm) in a plan view by brazing and fixing a predetermined-shaped copper plate having a thickness of about 2 mm or 2.5 mm. It is formed in an annular shape. Further, the coil portion 3 is formed with a workpiece insertion hole 3a having an inner diameter corresponding to the outer shape of the shaft portion Wa of the turbine shaft W which is a shaft-shaped workpiece that penetrates in the vertical direction at the center position and is quenched. A substantially annular convex portion 11 protruding downward by a dimension t2 (for example, 2 mm) is formed around the work insertion hole 3a on the lower end edge of 3a, that is, the lower surface 3d of the coil portion 3.

  At this time, the convex portion 11 is formed with a tapered surface having an angle θ1 = 45 degrees whose outer surface has a small diameter on the protruding direction side, and the workpiece insertion hole 3a has a small diameter on the inner surface of the workpiece insertion hole 3a. It is formed of a tapered surface with an angle θ2 = 45 degrees. Further, an annular cooling water flow path 3c is formed inside the coil part 3, and a plurality of injection holes 3c are formed outside the convex part 11 on the lower surface 3d of the coil part 3 in a state communicating with the cooling water flow path 3c. Is directed in the direction of the convex portion 11 at an angle θ3 = 30 degrees, and is formed on the lower surface 3d of the coil portion 3 at regular intervals in the circumferential direction. Then, both ends of the coil portion 3 in the circumferential direction are opposed to each other with a predetermined slit 12, and the pair of ends are brazed and fixed to the tips of the respective square pipes 8 of the holder 2, respectively. The coil portion 3 is supported by the holder 2.

  In the coil device 1 configured as described above, the terminal plate 7 is electrically connected to the output terminal of the transistor inverter as a high-frequency current generator, for example, by a pair of flexible cables (not shown), and the transistor inverter operates. Thus, a high-frequency current having a predetermined frequency is supplied to the coil unit 3 via the terminal plate 7 and the copper plate 4 (square pipe 8) of the coil device 1. Further, for example, a cooling water supply device (not shown) arranged integrally with the transistor inverter is connected to a hose connector 10, a round pipe 9, a cooling water flow path of the terminal plate 7, a square pipe through a pair of hoses (not shown). The cooling water is circulated and supplied into the cooling water flow path 3b of the coil portion 3 through the nozzle 8, and this cooling water is jetted from the injection hole 3c.

  Next, the effect | action at the time of quenching the turbine shaft W using the said coil apparatus 1 is demonstrated based on FIG. First, the turbine shaft W has a shaft portion Wa having a predetermined outer diameter and a predetermined length, and a flange portion Wb that is integrally formed at a predetermined position such as an end portion of the shaft portion Wa and is larger in diameter than the shaft portion Wa. ing. Further, a concave portion Wd as a polishing relief is formed at a connection portion between the flange portion Wb and the shaft portion Wa. And this turbine shaft W is inserted in the workpiece insertion hole 3a of the coil part 3 of the coil apparatus 1, and the convex part 11 of the coil part 3 is located in the upper surface side of the collar part Wb with a predetermined space | interval. The Further, the injection hole 3c formed in the lower surface 3d of the coil part 3 is set so as to be directed in the direction of the flange Wb that is obliquely below, and so that the flange Wb is not positioned below the injection hole 3c. 11 is set at the same height position as the end surface of the recess Wd whose lower surface is the shaft end surface Wc of the shaft Wa.

  In this state, when a high frequency current is supplied to the coil portion 3 for a predetermined time, an eddy current is induced at the end portion of the shaft portion Wa by the magnetic flux generated from the convex portion 11 portion and the end portion is induction-heated. After induction heating for a predetermined time, the supply of the high-frequency current to the coil unit 3 is stopped, and the cooling water is supplied from the cooling water supply device into the cooling water supply passage 3b of the coil unit 3 at a predetermined pressure. The cooling water is injected from the three injection holes 3c toward the flange portion Wb of the turbine shaft W and the end portion of the shaft portion Wa as indicated by an arrow A in FIG. The end of the shaft portion Wa is rapidly cooled by the injection of the cooling water, and the portion is quenched. At this time, the injection hole 3c is provided on the outer side of the convex portion 11 of the coil portion 3 so as to be directed obliquely inward and downward, and since the outer surface of the convex portion 11 is formed with a tapered surface, the injection hole 3c is injected from the injection hole 3c. The cooling water is injected well toward the step portion of the flange portion Wb and the shaft portion Wa. When quenching is completed by injecting the cooling water for a predetermined time, the cooling water supply device is deactivated and the injection of the cooling water from the injection hole 3c is stopped.

  After the cooling water is stopped, the remaining water remaining in the cooling water flow path 3b of the coil portion 3 drops downward as indicated by the arrow B in FIG. 8, and at this time, the injection hole 3c is placed outside the flange portion Wb. Since it is located and remaining water is prevented from dripping on the collar part Wb. Thereby, the end of the shaft portion Wa of the turbine shaft W can be quenched, and at this time, the shaft end surface Wc is well quenched. In addition, when quenching the whole shaft portion Wa, it is performed while moving the shaft portion Wa in the axial direction with respect to the coil portion 3 or moving the coil portion 3 in the axial direction with respect to the turbine shaft W. That is, in the case of the coil device 1, by providing the annular convex portion 11 projecting downward at the lower end edge of the work insertion hole 3a of the coil portion 3, the shaft end face Wc can be quenched to the limit, and the injection hole By providing 3c outside the protrusion 11 and outside the flange Wb, dripping of residual water onto the flange Wb is also prevented.

  As described above, according to the coil device 1, the annular convex portion 11 projecting toward the lower surface 3 d side of the coil portion 3 is formed at the lower end edge of the workpiece insertion hole 3 a of the coil portion 3, and the convex portion Since the injection hole 3c which can inject the cooling water in the coil part 3 into the quenching part of the turbine shaft W is provided on the outer side of the coil 11, the convex part 11 may be brought close to the end of the shaft part end surface Wc of the turbine shaft W. It is possible to effectively quench the shaft end surface Wc of the turbine shaft W and to suppress the splashing of the cooling water at the convex portion 11, and to stably obtain a high-quality quenching state on the turbine shaft W. It becomes.

Further, since the injection hole 3c of the coil portion 3 is provided outside the outer peripheral edge of the flange portion Wb of the turbine shaft W, the remaining water in the coil portion 3 is the flange portion Wb of the turbine shaft W after quenching is completed. It is possible to prevent dripping onto the flange portion Wb that does not require quenching to cause the portion to be in a quenching state, and to obtain a higher quality quenching state on the shaft end surface Wc of the turbine shaft W. Can do. Furthermore, since the inner surface of the workpiece insertion hole 3a of the coil portion 3 and the outer surface of the convex portion 11 are formed as tapered surfaces, the insertion of the turbine shaft W into the insertion hole 3a is easy with the tapered surface of the inner surface of the workpiece insertion hole 3a. In addition, the taper surface of the convex portion 11 can prevent adverse effects on the cooling water injection state. Further, by forming the inner surface of the workpiece insertion hole 3a with a tapered surface, it is possible to scatter by spraying and flow down the cooling water while collecting it in the workpiece insertion hole 3a, and the quenching device itself becomes dirty with the cooling water. Can be suppressed.

  Further, the lower surface of the convex portion 11 protruding from the lower surface of the coil portion 3 can function as a positioning member for the shaft end surface Wc of the coil portion 3, and the adjustment of the quenching width or the like of the shaft end surface Wc can be easily performed. And can be suitably used for quenching the turbine shaft W (shaft workpiece) of various forms. In addition, since the coil portion 3 is fixedly supported at the tip of the side-view plate-shaped holder 2 having a cooling function and an energizing function, the induction heating and cooling can be performed almost simultaneously by the holder 2, and it is easy to use. The coil device 1 can be obtained.

  In addition, in the said embodiment, although the inner surface of the workpiece | work insertion hole 3a of the coil part 3 was made into the taper surface, this invention is not limited to this, Even if it is a form which the workpiece | work insertion hole 3a has a vertical surface like the past. good. Moreover, in the said embodiment, although the coil apparatus 1 itself was exchangeable according to the form (outside diameter) of a shaft-shaped workpiece | work by fixing the coil part 3 to the holder 2, for example, the holder 2 is made common, It is good also as a structure which can replace only the coil part 3 according to the form of an axial workpiece. Furthermore, the thickness and width of the convex portion 11, the shape such as the inclination angle, the shape such as the thickness and size of the coil portion 3, the shape of the holder 2, and the like in the embodiment are merely examples, and each invention of the present invention. Appropriate configurations can be employed without departing from the gist of the invention.

  The present invention is not limited to the quenching of a turbine shaft having a flange, but can be used for quenching all shaft-like workpieces such as a shaft-shaped workpiece having no flange.

  DESCRIPTION OF SYMBOLS 1 ... Coil apparatus, 2 ... Holder, 3 ... Coil part, 3a ... Workpiece insertion hole, 3b ... Cooling water flow path, 3c ... Injection hole, 3d ... Lower surface, 4 ... Copper plate, 5 ... Insulating plate, 6 ... Bolt, 7 ... Terminal plate, 8 ... Square pipe, 9 ... Round pipe, 10 ... Hose connector, 11 ... Projection, 12 ... slit, W ... turbine shaft (shaft-shaped workpiece), Wa ... shaft, Wb ... collar, Wc ... shaft end surface.

Claims (2)

A shaft-shaped workpiece comprising: a coil portion having a workpiece insertion hole in the center portion and formed in a substantially annular shape in plan view; and a holder that supports both ends of the coil portion and can be connected to a high-frequency current generator. A coil apparatus for induction hardening capable of quenching,
The coil part is formed with an annular convex part projecting to the surface side of the coil part at the edge of the workpiece insertion hole, and the cooling water in the cooling water flow path provided in the coil part outside the convex part. Is provided in the quenching portion of the shaft-like workpiece , and the injection hole is provided outside the outer peripheral edge of the flange portion of the shaft-like workpiece having the shaft portion and the flange portion. A coil apparatus for induction hardening characterized by the above. The inner surface of the workpiece insertion hole of the coil portion is formed with a tapered surface with a small diameter on the convex portion side, and the outer surface of the convex portion is formed with a tapered surface with a small diameter on the protruding direction side. The induction hardening coil device according to claim 1.

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