JPS6262433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inductor that can measure the temperature of a heated surface while performing appropriate heating when hardening or tempering is performed by induction heating.

When hardening or tempering the surface layer of a material to be treated by induction heating, the facing gap between the material to be treated and the inductor should be 1 mm or more for high heating efficiency.
It is well known that it is extremely narrow at 2 mm. Therefore, as shown in FIGS. 1a and 1b, an inductor C is placed facing the rotating workpiece W with a predetermined gap therebetween.
The heating temperature at that point in time of the heating surface H, which is heating up due to heating, is particularly the highest temperature at approximately the center in the width direction of the heating surface, so we would like to measure the heating temperature by setting that point as the temperature measurement point P. However, it is not possible to measure the temperature at the temperature measurement point P with the required field of view f from a predetermined angle with respect to the heating surface H that allows at least appropriate temperature measurement using the line of sight temperature measurement line L of a sensing device such as a radiation thermometer. It was almost impossible. Note that in FIGS. 1a and 1b, Δ is a predetermined distance between the material W to be treated and the inductor C.

If the predetermined gap Δ is made large in order to facilitate temperature measurement, there will be problems such as poor heating efficiency and a change in the heating pattern. Therefore, an inductor C' as shown in FIG. 2a was developed for the purpose of measuring the temperature at a point P at the center of the heating surface H in the width direction. The inductor C' has a detection hole ex with a diameter of 4 mm to 10 mm that penetrates vertically from the outside to the inside in the center direction at a predetermined position in the width direction.
Ex is removed and the temperature at point P is measured using a radiation thermometer or the like. However, since the current flows through the inductor C' avoiding the detection hole ex, the current density in the width direction is not uniform, and accordingly, there is no uniformity in the inductor of the heated material W. Since the induced current i as shown by the arrow shown in Fig. 2b flows, the point P on the circumference of the workpiece W that is originally opposed to the inductor.
The temperature is highest near the center, including the area shown in Figure 2c.
The temperature characteristic curve shown by A is supposed to be
As shown as B, the temperature near the point is low, and the inductor
The temperature characteristic curve has the highest temperature portions in opposing portions corresponding to the portions sandwiched between both end faces of C′ and the detection hole ex, and the purpose of measuring the highest temperature portion on the heating surface H cannot be achieved. Aside from the inadequacy of the inductor C' for the temperature measurement described above, the particularly problematic drawback is that in heating methods such as stationary hardening, in which the inductor C' is fixed, the low temperature near the center in the width direction causes The result is non-uniform heat treatment.
Moreover, since the diameter of the detection hole ex is quite large, if the width of the inductor C' is narrow, the flow path of the self-cooling fluid flowing through the tube of the inductor C' formed of a tube material will be narrowed. As a result, the cooling effect is reduced, leading to accelerated wear and tear on the relevant parts, and also causing pipe clogging due to adhesion of metals, non-metallic substances, etc. dissolved in the cooling fluid. Therefore, this inductor
C' is considered to be of no practical use except for large inductors where the size of the detection hole ex can be ignored, and is rarely used, and the heating temperature for quenching and tempering is still based on years of experience and intuition. The current situation is that we rely on them.

However, in recent years, there has been an extremely strong demand for eliminating experience and intuition and determining heat treatment conditions based on measured values in order to achieve a uniform finish on the treated material.

The present invention meets the above requirements and provides an inductor capable of measuring the temperature of a heated surface without any of the drawbacks of conventional inductors.

The present invention will be explained according to the embodiments shown in FIGS. 3 to 6. FIGS. 3a and 3b show a first embodiment of the present invention, in which an inductor C ₁ is wound around a predetermined gap Δ that allows efficient heating of a rotating workpiece W, for example, a shaft member. For example, a protrusion B protruding perpendicularly to the heating surface is formed on the outside of the opposite side of the lead portion R, and a slit S is formed on the corresponding inside. The slit section S allows for proper temperature measurement at least at the temperature measurement point using a temperature detection device such as a radiation thermometer, for example, at a point P approximately at the center in the width direction of the heating surface H, that is, at the highest temperature point. The required range of field of view f from the angle α
The inductor is set to a length and width that can ensure the temperature measurement line L that is viewed with a
The cross-sectional area of the bent portion of C ₁ is formed to be approximately the same as the cross-sectional area of the portion wound around the workpiece W with a predetermined gap therebetween. Therefore, not only is it possible to properly measure the temperature near the point P showing the highest temperature on the heating surface H, but also the current density in the width direction of the current flowing through the inductor _C1 is averaged, and moreover, Even if the current is separated from the workpiece W, the slit portion S
Since a current having the same strength as the opposite surface of the winding section facing the opposite surface with a predetermined gap Δ flows through the heating surface H of the workpiece W facing the slit section S, the presence of the slit section S causes It exhibits the induced heat generation phenomenon due to induced current similar to that of an inductor that is normally used without holding, and therefore the temperature near the temperature measurement point P is almost the highest, so the purpose of temperature measurement can be achieved. Moreover, since the passage for the self-cooling cooling fluid is also designed so that the cross-sectional area of the bent portion does not change, the flow is not obstructed.
Note that the above describes the case where the inductor C ₁ is stationary with respect to the material to be treated W, but when the inductor C ₁ and the material to be treated W move relative to each other, the part showing the highest temperature is the heating surface. Since it appears slightly displaced in the opposite relative movement direction from approximately the center in the width direction of H, it goes without saying that the position of the temperature measuring point P is also displaced accordingly.

Figures 4a and 4b show a second embodiment of the invention. At a predetermined position of the inductor _C2 , a protrusion B', which is almost the same in appearance as the first embodiment, is formed to protrude in a direction perpendicular to the heated surface H of the material W to be processed.
As shown in FIG. 4b, the slit portion
The upper half of the protrusion B'-direction wall of S' in the figure is on the inclined surface B' ₁ that is almost parallel to the temperature measuring line L, and the lower half is on the inclined surface B' 1 to the extent that it does not block the field of view f looking at the temperature measuring point P. Since it is formed on the parallel plane B' ₂ close to the material to be treated W, the cross section of the inductor C ₂ at this part has a trapezoidal shape. The cross-sectional area is also set to be the same as that of the other winding parts. The current density in the width direction flowing through the inductor _C2 is uniform as explained in the first embodiment, and the cooling fluid can easily circulate, so the effects of the inductor _C2 of this embodiment are also the same as those of the first embodiment. Although it is almost the same as the previous example, it is used when higher heating efficiency is desired, even if it is only a small amount.

In the third embodiment inductor _C3 shown in FIG. 5, for example, a shaft having a flange is used as the material to be treated W'
Used when heating the surface layer of the connection between the shaft and flange for hardening or tempering. Therefore, the circumferential surface of the shaft portion and the end surface of the flange portion are heated simultaneously by one inductor C ₃ that maintains an appropriate heating gap △ with each, but the protrusion of the inductor C ₃
B'' is formed to protrude in the perpendicular direction to the flange portion which is both the heating surface H and the temperature measuring surface, and the slit portion S'' is formed to a predetermined depth and a width extending from the outer periphery to the inner periphery of the inductor _C3 toward the center. It is formed as a wide through groove. Therefore, in addition to measuring the temperature of the heating surface H of the flange part using the dielectric _C3 , it is also possible to measure the temperature of the heating surface H of the flange part after heating the connection part between the flange part and the shaft part, and then when heating the shaft part by the relative movement shown by the arrow, which is generally performed. The temperature of the heating surface can also be measured within an appropriate temperature measurement angle range (it is also possible to set the temperature measurement line L of the detection device perpendicular to the heating surface). The cross-sectional area of the bent portion is, of course, the same as that of the winding portion. The current flowing through the inductor _C3 also has the same density in the width direction, which causes the material to be treated to
Since most of the induced current induced on the surface of W' facing the inductor _C3 is short-circuited in the circumferential direction at the portion facing the slit, no irregularity occurs in the heating in the width direction of the heating surface H. However, since a negligible amount of heat is generated around the shaft portion facing the protrusion B'', the heating efficiency for the surface to be heated is slightly lower than in the above two embodiments.

The first invention of the present application has been described in detail using three embodiments, and the second invention will be explained in accordance with the fourth embodiment shown in FIGS. 6a and 6b. The inductor _C4 shown in FIG. 6 is used when the angle (incidence angle) at which the temperature measurement line L of the detection device is viewed with respect to the heating surface H is set to an angle β that is closer to perpendicular than in the previous embodiment. hand,
Desired acute angle θ with respect to the perpendicular x drawn to the temperature measurement point P
The center line of the protrusion B is formed to protrude upward or downward in a side view so that the center line thereof is inclined. Therefore, the wall surface facing the heating surface H of the required width slit portion S formed inside the protrusion B is similar to this.
It is arranged obliquely at an angle of 90°-θ. inductor
The heating efficiency of C ₄ is completely unchanged from the first example.
In addition, since the protruding portion B protrudes at an acute angle with respect to the heated surface H, the non-heated surface is not affected by the magnetic flux.

FIG. 7 shows an inductor C ₅ which is an application example of the inductor C ₄ shown in FIG. 6 and which allows the temperature measuring line L to be viewed from a deeper angle β' than the heating surface H.

It goes without saying that in the two embodiments of the second invention, the cross-sectional area of the bent portion is set to be approximately the same as that of the other winding portions.

According to the present invention, (1) heating is possible without any influence of the structure for temperature measurement in the inductor, that is, the slit portion, on the heating surface; and (2) the heating is also possible between the material to be treated and the inductor. Since the gap is separated by a predetermined gap with high thermal efficiency, it is possible to obtain almost the same efficiency as in a normal inductor. (4) Moreover, since the temperature measuring structure does not obstruct the flow of the cooling fluid for self-cooling the inductor, it can guarantee the same service life as a normal inductor. Attach it to a hardening device etc. equipped with the function,
This inductor will have extremely high practical utility in the future as it is suitable for constantly detecting the temperature of the heating surface during heating and numerically controlling the heating time, heating power, etc. based on this.

[Brief explanation of the drawing]

Figures 1a and 1b are partially sectional front views for explaining the positional relationship between the material to be treated and the inductor, respectively;
Fig. 2a is a partial cross-sectional front view of a conventional temperature measuring inductor, and Fig. 2b shows a current flowing through the material to be treated to explain the drawbacks when using the inductor shown in Fig. 2a. 2c is a diagram comparing the temperature characteristic curve B of the heating surface by an inductor shown in FIG. 2a with the temperature characteristic curve A of the heating surface by a normal inductor,
Figures 3a and 3b are a plan view and a cross-sectional front view of an inductor according to the first embodiment of the present invention, respectively;
Figures a and b are a plan view and a sectional front view, respectively, of an inductor according to a second embodiment of the present invention, and Figures 5 a and b are a perspective view and a sectional front view, respectively, of an inductor according to a third embodiment of the present invention. 6a and 6b are a perspective view and a sectional front view of an inductor according to a fourth embodiment of the present invention, and FIG. 7 is a sectional front view of an applied inductor according to a fourth embodiment. C ₁ , C ₂ , C ₃ , C ₄ , C ₅ ... Inductor, W ... Material to be treated, B, B', B'', B ... Protrusion, S, S',
B'', S...Slit part, H...Heating surface of the material to be treated, α, β, β'...Angle that allows proper temperature measurement of the heating surface, L...Temperature measurement line, f...Measurement warm line field of view,
θ……Acute angle with respect to the perpendicular to the heating surface.

Claims (1)

[Scope of Claims] 1. In an inductor that winds a material to be treated with a predetermined gap and heats the opposing surface by induction, a protrusion that protrudes in a direction perpendicular to the heated surface of the material to be treated is provided outside a predetermined position. , a slit portion is formed on the inside corresponding to this to ensure a temperature measurement line that can be viewed with the required field of view from an angle that allows proper temperature measurement at least approximately at the center in the width direction of the heating surface, and the slit portion 1. An inductor capable of measuring temperature of a heating surface, characterized in that a cross-sectional area of a bent portion formed by the projection and the protruding portion is approximately the same as a cross-sectional area of the winding portion. 2. In an inductor that winds a material to be treated with a predetermined gap and heats the opposing surface by induction, a protrusion protrudes outward at an acute angle to a perpendicular to the heating surface of the material to be treated outside a predetermined position. A slit part is formed on the inside corresponding to this to ensure a temperature measurement line that can be viewed from an angle that allows proper temperature measurement with the required field of view, even if the approximate center of the heating surface is removed, and the slit part and the above-mentioned 1. An inductor capable of measuring temperature of a heating surface, characterized in that a cross-sectional area of a bent portion formed by a protruding portion is approximately the same as a cross-sectional area of a winding portion.