JPS6262432B2 - - 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 FIG. 1, the heating temperature at that point in time of the heating surface H, which is being heated by the inductor C disposed facing the rotating workpiece W with a predetermined gap, and especially the heating temperature. The highest temperature is approximately at the center in the width direction of the surface, so even if you want to measure the heating temperature using that point as temperature measurement point P, it is difficult to measure the heating temperature at least properly using the line of sight temperature measurement line L of a sensing device such as a radiation thermometer. It is almost impossible to measure the temperature at the temperature measurement point P from a predetermined angle with respect to the heating surface H that allows temperature measurement with the required field of view f. In FIG. 1, Δ is a predetermined gap 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 the center point P in the width direction of the heating surface H. 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 in the width direction at a predetermined position.
The temperature at point P is measured using a radiation thermometer or the like through ex. However, since the current flows through the inductor C' avoiding the detection hole ex, the current density is not uniform in the width direction, and as a result, the periphery of the heated material W facing the inductor is Since an induced current as indicated by the arrow shown in FIG.
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 by B, the temperature near point P 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 temperature of the highest temperature portion on the heating surface H cannot be achieved. Aside from the inadequacy of the inductor C' for the temperature measurement mentioned 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 cooling fluid for self-cooling flowing through the pipe of the inductor C′ formed of a pipe material may be reduced. Because it is narrow, the cooling effect is reduced and the wear and tear of the part concerned is accelerated.
This can also cause pipe clogging due to adhesion of metals and non-metallic substances dissolved in the cooling fluid. Therefore, this inductor C' is considered to be of no practical use except as a large inductor where the size of the detection hole ex can be ignored, and is rarely used, and the heating temperature in hardening and tempering is still The current situation is that we rely on many years of experience and intuition.

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 5. FIGS. 3a and 3b show a first embodiment of the present invention, in which an inductor C1 is wound around a predetermined gap Δ that allows efficient heating of a rotating workpiece W, for example _a shaft member. position, e.g. lead part R
A slit portion S parallel to the perpendicular line X to the heating surface H is formed on the inner periphery on the opposite side. The slit portion S is, for example, a temperature detection device such as a radiation thermometer,
A point P approximately at the center in the width direction of the heating surface H, that is, the highest temperature part, is set as a temperature measurement point, and the temperature measurement point P is viewed with a field of view f within a predetermined range from an angle α that allows at least appropriate temperature measurement. The length and width are set to ensure the temperature measurement line L. Therefore, it is possible to properly measure the temperature near the point P showing the highest temperature on the heating surface H, and the width of the inductor _C1 facing the heating surface is kept uniform over the entire circumference. The current density in the width direction of the flowing current is average, and even if the current flows in the slit portion S along the circumferential wall of the inductor _C1 in a short section away from the material W to be treated, the current densities in the width direction of the flowing current are A current having the same strength as the opposite surface of the winding part facing the opposite part with a predetermined gap Δ flows through the heated surface H of the material W to be processed, and therefore, despite the existence of the slit part S, the current is normally used. It exhibits a heat generation phenomenon due to the induced current similar to that of an inductor, and the temperature reaches almost the maximum near the temperature measurement point P, thus achieving the purpose of temperature measurement. In addition, the above description is about 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 will be on the heating surface. Since it appears slightly displaced in the opposite relative movement direction from approximately the center in the width direction, it goes without saying that the position of the temperature measurement point P is also displaced accordingly. Nao is
The electrical insulating material shown as is inserted between the parallel lead members R ₁ and R ₂ .

In the above embodiment, even if the slit portion S is formed between the inner circumference and the outer circumference of the inductor _C1 , that is, the thickness is relatively larger than the width, and the slit portion S is able to measure the temperature appropriately, the inductor
Applicable when the flow of cooling fluid for self-cooling of _C1 is not significantly obstructed.

Next, a second embodiment of the present invention is shown in FIGS. 4a and b.
The following will be explained. In this embodiment, the slit portion S' formed at a predetermined position of the inductor _C2 is provided between the lead members _R1 and _R2 of the lead portion R that connects both ends of the winding portion to the output terminal, respectively. ing. Therefore, unlike the slit portion S in the first embodiment, the passage of the cooling fluid for self-cooling is not made narrow, and the measurement is performed when viewed from an angle β that is more perpendicular to the heating surface H of the workpiece W. It is possible to secure the warm line L with the required field of view f. Of course, the induced current flowing through the heating surface H of the workpiece W facing the winding part short-circuits the slit part S' and flows at a uniform current density in the same width direction as in the winding part, so normally A heat generation phenomenon occurs in a pattern similar to that of the inductor C, and the part showing the highest temperature is near the temperature measurement point P, so that proper temperature measurement can be performed.

The embodiment shown in FIGS. 5a and 5b is an application example of the second embodiment shown in FIG.
By making the length l of S'' longer than in the above embodiment, the width of the inductor _C3 facing the heating surface H of the material W to be treated is wide, that is, the point P showing the highest temperature at the center in the width direction. This is suitable when the position is deeper than the end surface of the inductor _C3 , or when it is desired to secure the temperature measurement line L viewed at an angle β' that is more perpendicular to the heating surface H.The above-mentioned slit portion S The length of the workpiece W is determined by moving the temperature measurement line L from L ₁ to L ₂ while maintaining the angle β, as shown in Fig. 5b.
It is possible to measure the temperature over a wide range of heating surfaces H in the width direction.
These effects are sufficient to compensate for the slight increase in impedance in the lead portion R.

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, the same heating efficiency as that of a normal inductor can be obtained, and (3) proper temperature measurement of not only the highest temperature part but also the necessary part is possible. (4) Furthermore, even though it is a temperature measuring structure, it does not obstruct the flow of the cooling fluid for self-cooling the inductor, so it can guarantee the same service life as a normal inductor. ) Moreover, since the structure of the inductor is simple, there are no particular difficulties in manufacturing it, and it can be easily manufactured.
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]

Figure 1 is a partially sectional front view for explaining the positional relationship between the material to be treated and the inductor, Figure 2a is a partially sectional front view of a conventional temperature measuring inductor, and Figure 2b is
is a front view showing the current flowing through the material to be treated to explain the drawbacks when using the inductor shown in Fig. 2a, and Fig. 2c shows the temperature characteristics of the heated surface by the inductor shown in Fig. 2a. A diagram comparing curve B with temperature characteristic curve A of a heating surface by a normal inductor, FIG.
Fig. b is a cross-sectional front view taken along line A-A in Fig. 3a, Fig. 4a is a plan view of an inductor according to a second embodiment of the present invention;
FIG. 4b is a front view of the section taken along line B-B in FIG. 4a, FIG. 5a is a plan view of the third embodiment of the inductor of the present invention, and FIG. It is a cross-sectional front view. C ₁ , C ₂ , C ₃ ... Inductor, W ... Material to be treated, H
...Heating surface of the material to be treated, X...Perpendicular to the heating surface of the material to be processed, S, S', S''...Slit part, α,
β, β'...Appropriate temperature measurement angle, f...Field of view, L,
L ₁ , L ₂ ... Temperature measurement line, R and R ₁ , R ₂ ... Lead part and lead member.

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 slit portion is provided on the inner periphery at a predetermined position parallel to a perpendicular to the heating surface of the material to be treated. A method for measuring a heating surface, characterized in that the heating surface is formed so as to ensure a temperature measurement line that can be viewed with a 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. Warmable inductor. 2. Claim 1, characterized in that the slit portion formed on the inner periphery at a predetermined position is provided between parallel lead members connecting both ends of the winding portion to the output terminal, respectively. An inductor that can measure the temperature of the heating surface.