JP2007327128A - High-frequency induction heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency induction heating apparatus having narrow width shaft part which, without changing the whole shape of a coil portion and a silicon steel material covering the coil portion in a semi-opening saddle type high frequency induction heating coil, can cope with the narrow width shaft part, wherein the existing structure of semi-opening saddle type high frequency induction heating coil can be used and the generation of melting part to one pair of side plates can be prevented and such trouble as the development of electric power loss and also, the lowering of heating efficiency can be avoided. <P>SOLUTION: In the semi-opening saddle type high frequency induction heating coil 2, the opposite side interval between one pair of coil portions 2a, 2b oppositely and parallely set and also, oppositely set to surfaces to be heated, are set to be wider than the length size along the opposite direction of the one pair of coil portions 2a, 2b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a high-frequency induction heating device, and more specifically, a semi-open saddle type high-frequency induction heating coil disposed between a pair of side plates facing each other with a gap on a narrow shaft portion having a width of 17 mm to 22 mm. The high-frequency induction heating apparatus is configured to perform high-frequency induction heating of the shaft portion while causing the semi-open saddle type high-frequency induction heating coil to follow the shaft portion. The present invention also provides a high-frequency induction heating apparatus including a high-frequency induction heating coil for performing high-frequency quenching on a narrow shaft portion such as a pin portion of a crankshaft of a small engine, and a side plate that holds the high-frequency induction heating coil. In particular, a high-frequency induction heating apparatus that can reduce the set voltage and reduce the heating time and output, can stably form a desired hardened and hardened layer, and can improve durability. About.

  5 (a) and 5 (b) show a high-frequency induction heating apparatus 1 generally used in an induction hardening mechanism for quenching a shaft portion such as a pin portion P (see FIGS. 5a and 8) of a crankshaft, for example. The structure around the heating coil in 'is shown. As shown in FIGS. 5 (a) and 5 (b), this high-frequency induction heating device 1 'is connected to a semi-open saddle type high-frequency induction heating coil 2 made of a pipe material having a cooling water circulation hollow portion. Cooling water is supplied to the power supply lead conductors 3a and 3b, the connection terminals (blocks) 4a and 4b that connect the power supply lead conductors 3a and 3b and the high-frequency power source (not shown), the high-frequency induction heating coil 2, and the like. The cooling water supply conduit 5 to be sent and the semi-open saddle type high-frequency induction heating coil 2 made of ceramic for mounting on a pin part of a crankshaft (work to be heated) (not shown) with a slight gap therebetween, or Chips 6a, 6b, 6c made of cemented carbide are provided, and these members are held and installed between a pair of side plates 7a, 7b arranged to face each other in parallel. Thus, under the state where the semi-open saddle type high frequency induction heating coil 2 installed between the pair of side plates 7a and 7b is placed on the pin portion of the crankshaft via the chips 6a to 6c with a slight gap therebetween. The follower mechanism (not shown) is moved to follow the pin portion P (shaft portion) rotated about the axis of the crankshaft, and the outer peripheral surface of the pin portion P is heated by high frequency induction during this time. ing.

  In this case, as shown by arrows A and B in FIG. 6, a certain instantaneous current supplied from a high-frequency power supply (not shown) to the high-frequency induction heating coil 2 is a series of power supply lead conductors 3a from the power supply side. It is introduced into the high-frequency induction heating coil 2 (including the coil portions 2a and 2b), proceeds to the return-side power supply lead conductor 3b, and is sent to the power supply side. At the next moment, a current flows in the opposite direction. However, in the present specification, for simplification of description, for convenience, one of the power supply lead conductors 3a and 3b of one instantaneous pair of power supply lead conductors 3a is referred to as an “advance side”, and the other The direction feeding lead conductor 3b is referred to as "return side".

  On the other hand, the pin portion P of the crankshaft is hardened in a range of a dimension T in the depth direction perpendicular to the axis B and having a dimension L in the lateral direction along the axis B of the pin part P as shown in FIG. It is necessary to form the hardened layer S. For example, in the case of a pin portion P having a narrow pin width dimension of about 18 mm, various devices are used to accurately form the hardened hardened layer S. Therefore, conventionally, pipe materials 8a and 8b for the semi-open saddle type high frequency induction heating coil 2 as shown in FIG. 8 have been used.

  The pipe members 8a and 8b shown in FIG. 8 are continuously connected to each other and arranged to face each other, and are composed of a pair having the same cross-sectional dimension. For example, the lateral dimension of the pin portion P is 18 mm. In this case, a size as shown in FIG. 8 is adopted. These pipe members 8a and 8b (coil portions) are composed of those having a horizontal dimension of 5 mm and a vertical dimension of 9 mm, and a part of the outer periphery of the pipe members 8a and 8b (excluding portions α and β facing the pin portion P). The whole portion is encapsulated by magnetic steel plates 9a and 9b for concentrating magnetic flux in order to improve heating efficiency. These silicon steel plates 9a and 9b are for efficient current flow, and are used for pipe materials 8a and 8b for ordinary high-frequency induction heating coils. In addition, as shown in FIG. 8, the interval in the horizontal direction (direction along the axis C) of the silicon steel plates 9a and 9b enclosing the pipe materials 8a and 8b is set to 1 mm, for example, and a pair of pipe materials (coils facing each other) The interval between the portions 8a and 8b is set to be narrower than the lateral dimension (5 mm) of the pipe members 8a and 8b.

  Table 1 below shows the experimental results in the case where the quenching treatment was performed by high-frequency induction heating and rapid cooling of the pin portion P of the crankshaft by the semi-open saddle type high-frequency induction heating coil 2 shown in FIGS. 6 and 8. Is shown.

As shown in Table 1 above, when the set voltage is 450 V to 510 V, the formed hardened layer has a depth even if the heating time is 10 sec to 12 sec and the output is 57.5 kW to 82.4 kW. In addition, both the range and the range were not measurable (see tests 1 to 7). On the other hand, when the set voltage is 520 V, the heating time is 15 sec, and the output is 84.0 kW (see test 8) as conditions, the hardened and hardened layer S ₁ (the axis of the journal portion of the crankshaft) as shown in FIG. (The top portion on the side far from the not shown) and the hardened hardened layer S ₂ (the bottom portion on the side relatively close to the axis (not shown) of the journal portion of the crankshaft). A measurable hardened layer was obtained, but the hardened layers S ₁ and S _{2 were} insufficient (non-uniform and shallow hardened layer). In order to form an ideal hardened and hardened layer S as shown in FIG. 4, it is necessary to further increase the set voltage, heating time and output, which requires high power consumption, and the problem of breakage of the high-frequency induction heating coil body In addition, there is a problem that the heating time becomes long and the productivity is lowered. The reason why the hardened and hardened layers S ₁ and S ₂ are insufficient as described above is that the interval between the pipe members 8a and 8b facing each other is narrow, and the magnetic flux is largely canceled at the interval. .

  Further, when high frequency induction heating (high frequency quenching) is continued under the above conditions, a melting portion W (melt hole 10 in the worst case) is generated at a specific location on the side plates 7a and 7b as shown in FIG. It may be a defective product. Incidentally, the melted portion W is mainly formed at a position indicated by a symbol γ in FIGS. 5 (a) and 5 (b). This portion γ is a position where the lead-side power supply lead conductor 3a and the return-side power supply lead conductor 3b of the semi-open saddle type high frequency induction heating coil 2 are closest to each other or in the vicinity thereof. That is, the position γ is a position where the advancing side portion and the return side portion of the lead conductor for feeding are closest to each other as shown in FIG. 5A, and the feeding side of the advancing side as shown in FIG. 5B. The lead conductor 3a for return and the lead conductor 3b for feeding on the return side are arranged so as to overlap each other in the width direction between the side plates 7a and 7b in a side view, and the lead conductors 3a and 3b for feeding and the side plates 7a and 7b Is the portion where the distance between the two is the narrowest (the portion where it is narrower than the other portions), the high frequency induction action between them is the largest, and the portion is generally hotter than the other portions, and the melting portion W This is because it is the most likely place. In addition, when such a melt | dissolution part W arises, the loss of high frequency electric power will have arisen for this melt | dissolution part W, and it will result in causing the efficiency fall of high frequency induction heating.

  The present invention has been made in view of the problems as described above, and its purpose is to change the coil portion of the semi-open saddle type high frequency induction heating coil and the overall shape of the silicon steel material enclosing it. It is possible to use a narrow shaft portion (for example, a pin portion of a crankshaft), a semi-open saddle type high frequency induction heating coil having an existing structure can be used, and a melted portion is generated on a pair of side plates. It is an object of the present invention to provide a high-frequency induction heating apparatus having a narrow shaft portion that can be prevented and avoids problems such as generation of power loss and thus reduction in heating efficiency.

In order to achieve the above-mentioned object, in the present invention, a semi-open saddle type high frequency induction heating coil disposed between a pair of side plates facing each other is placed on a narrow shaft portion having a width of 17 mm to 22 mm which is a heating target. In the high-frequency induction heating apparatus in which the shaft portion is subjected to high-frequency induction heating while the semi-opened saddle type high-frequency induction heating coil is made to follow the shaft portion under a state of being placed with a gap therebetween, the half-opening Among the saddle type high frequency induction heating coils, the facing distance between a pair of coil portions having the same width is disposed opposite to and parallel to the heated surface of the shaft portion. The coil portion is set wider than the length dimension along the facing direction of the coil portion.
In the present invention, when the width dimension of the shaft portion is 18 mm, the overall width in the facing direction of the pair of coil portions is 13 mm, the lateral width dimension of the coil portions is 4 mm, and the vertical length of the coil portions is The dimension is 8 mm, and the distance between the pair of coil portions is 5 mm.
In the present invention, a part of the outer periphery of the coil portion is encapsulated with a silicon steel material.
Moreover, in this invention, a part of outer periphery of the said coil part encapsulated by the said silicon steel material is made to be the whole part except the surface facing the said axial part.
In the present invention, the high-frequency induction heating coil and a part of the side plate holding the power-feeding lead conductor connected to the high-frequency induction heating coil, and the lead-side power feeding lead conductor and the return side A through hole is formed at a position closest to or near the power supply lead conductor.

  The present invention according to claim 1 is a pair of coil portions having a width equal to each other, arranged in parallel with each other, and opposed to the heated surface of the shaft portion, of the half-open saddle type high frequency induction heating coil. The spacing between the coil portions is set to be wider than the length dimension along the facing direction of the pair of coil portions. Therefore, the spacing between the pair of coil portions is widened as much as possible. By making it larger than (width dimension along the axial direction of the shaft portion), interference (cancellation of magnetic flux) between a pair of opposing coil portions can be suppressed, and power loss can be reduced as a result. A desired quench hardened layer can be stably formed with low power and short heating time. In addition, it can be applied to a narrow shaft portion (for example, a pin portion of a crankshaft) without changing the entire shape of the coil portion of the semi-open saddle type high frequency induction heating coil and the silicon steel material enclosing the coil portion. It is possible to use a semi-open saddle type high frequency induction heating coil of the structure.

  According to the second aspect of the present invention, when the width of the shaft portion is 18 mm (in the case of a narrow shaft portion), the overall width in the facing direction of the pair of coil portions is 13 mm. Since the width dimension is 4 mm, the vertical dimension of the coil part is 8 mm, and the distance between the pair of coil parts is 5 mm, the standard is used when the dimension of the shaft part is limited as described above. By using a coil portion (for example, a pipe material) having the structure described above, it has been confirmed by experiments that the above-described effects can be efficiently achieved with respect to the narrowest shaft portion.

  Further, in the present invention according to claim 3, since a part of the outer periphery of the coil portion is encapsulated by the silicon steel material, the magnetic flux can be concentrated on the heated portion, and the high frequency The efficiency of induction heating can be further increased, and as a result, a desired hardened and hardened layer can be formed.

  Further, in the present invention according to claim 4, since a part of the outer periphery of the coil part encapsulated by the silicon steel material is the whole part excluding the surface facing the shaft part, It is possible to further increase the efficiency of heating and to reliably form a desired hardened layer.

  According to a fifth aspect of the present invention, there is provided a high frequency induction heating coil and a part of a side plate for holding a power supply lead conductor connected to the high frequency induction heating coil, and a lead side of the power supply lead conductor. Since the through hole is formed at a position where the part and the return side part are closest to each other or at a position near the position, there is a through hole at a predetermined position of the side plate, so that high heat is generated at the formation part of the through hole. Therefore, the generation of the melted portion in the side plate can be reliably prevented, and as a result, the durability of the high-frequency induction heating device can be improved.

  Hereinafter, the high frequency induction heating apparatus 1 which concerns on one Embodiment of this invention is demonstrated with reference to FIGS. The high-frequency induction heating device 1 of the present embodiment is a device of the same type as that shown in FIGS. 5 (a) and 5 (b), and is a half-open saddle type disposed between a pair of side plates facing each other. Under the state where the high frequency induction heating coil 2 is placed on the narrow shaft portion 14 having a width of 17 mm to 22 mm to be heated with a gap, the semi-open saddle type high frequency induction heating coil 2 is moved to the shaft portion 14 ( This is a high frequency induction heating device in which the shaft portion 14 is subjected to high frequency induction heating while following the pin portion P) of the crankshaft. Accordingly, in FIGS. 1 to 4, the same parts as those shown in FIGS.

  As shown in FIG. 2, the high frequency induction heating coil 2 used in the high frequency induction heating apparatus 1 (see FIG. 1) in the present embodiment has a pair of coil portions 2a and 2b extending in parallel and facing each other with a silicon steel material 9a. , 9b and is made of pipe members 8a, 8b having a rectangular cross section having a hollow portion 12 for circulating a coolant. The high frequency induction heating coil 2 of the present embodiment is applied to high frequency induction heating of a narrow shaft portion (for example, a pin portion P of the crank shaft) having a dimension along the axis of 18 mm. Even when the dimension of the shaft portion 14 is different from this, it is possible to adopt one having substantially the same overall configuration as this example, and it is desirable to determine the detailed dimension experimentally. In this case, it is possible to use a semi-open saddle type high frequency induction heating coil 2 having an existing structure.

In the present embodiment, a pair of coil portions having equal widths that are disposed opposite to each other in parallel with each other and are opposed to the surface to be heated of the shaft portion 14 in the semi-open saddle type high frequency induction heating coil 2. 2a, opposing distance L ₁ between 2b is set to 5 mm, a pair of coil portions 2a, is wider set than 2b length L ₂ along the opposing direction of the (4 mm). Specifically, when the width of the shaft portion 14 is 18 mm, the horizontal width L ₂ of the coil portions 2a and 2b is 4 mm, and the vertical length L ₃ of the coil portions 2a and 2b is 8 mm. The distance L ₁ between the coil portions 2a and 2b is 5 mm. Here, the reason why L ₁ > L ₂ is set is that the interval between the pair of coil portions 2a and 2b is widened as much as possible to avoid canceling out magnetic flux between them. Further, part of the coil portions 2a and 2b (in the present embodiment, the entire portion excluding the surfaces 2c and 2d facing the shaft portion 14) are encapsulated by the silicon steel materials 9a and 9b, but are opposed to each other. The gap L _{4 in} the lateral direction between the silicon steel materials 9a and 9b is set to 1 mm (see FIG. 2).

  On the other hand, as shown in FIGS. 1 and 3, the pair of side plates 7a and 7b used in the high-frequency induction heating device 1 of the present embodiment has a specific portion γ, that is, a lead conductor 3a for feeding on the leading side. And the return-side power supply lead conductor 3b are closest to each other, and the portion γ where the distance between the power-supply lead conductors 3a, 3b and the side plates 7a, 7b is the narrowest (originally the highest heat The through-holes 15 are formed in advance in portions corresponding to the locations).

  Table 2 below shows the formation state of the hardened and hardened layer S when the shaft portion 14 is induction-heated by the high-frequency induction heating apparatus 1 having the above-described configuration and subjected to quenching treatment.

  As shown in Table 2 above, using the semi-open saddle type high frequency induction heating coil 2 shown in FIG. 2 with a heating voltage of 8 to 10 seconds at a set voltage of 300 V or 350 V and an output of 27.0 kW to 36.5 kW. When quenching was performed by high-frequency induction heating, as shown in Table 2, the depth and range were close to the desired value or the desired value, respectively. Thus, by applying the high frequency induction heating coil 2 shown in FIG. 2 to the shaft portion 14 having a dimension of 18 mm under the conditions of Table 2, a good hardened and hardened layer S as shown in FIG. 4 can be formed. Was confirmed. Table 3 below shows the results of experiments conducted to compare the present invention with the prior art.

  As shown in Table 3, in the case of the present invention test (a), the set voltage is 300 V, the heating time is 8.0 sec, the output is 27.0 kV, and in the case of the present invention test 6 (b), the set voltage is Compared to 350V, the heating time is 8.0 sec, and the output is 34.0 kV. In the conventional test 1 (c), the output is 57.5 kw when the heating time is 10.0 sec at the set voltage 450V, and the conventional test 8 (d). Then, even if the heating time is 15 sec at a set voltage of 520 V and the output is 84.0 kw, the shape of the hardened and hardened layer to be formed is the same as the desired one in the present invention, and is formed stably. On the other hand, it has been found that the conventional technology cannot stably form a material satisfying the desired value. Further, due to the presence of the through holes 15 in the side plates 7a and 7b, no melted portion was generated in the present invention.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, in the description, the shaft body (pin part) having a width of 18 mm is described in the embodiment, but the present invention is applicable to high-frequency induction heating for a narrow shaft part having a width of 17 mm to 22 mm. Further, the coil portions 2a and 2b are not limited to the cross-sectional shape and cross-sectional dimensions of the coil portions 2a and 2b exemplified in the above-described embodiment, and the coil portions 2a and 2b are not pipe members 8a and 8b but are solid without a hollow portion. It may be a conductor. Moreover, the shape of the through-hole 15 formed in the side plates 7a and 7b is not limited to a longitudinal hole whose upper and lower ends are semicircular, but may be various shapes such as a rectangular shape and a square shape. The dimensions and shapes of the silicon steel materials 9a and 9b may not be the same as each other. For example, as shown in FIGS. 9 (a), 9 (b), and 9 (c), the overall dimensions and It is possible to obtain a desired hardened and hardened layer by appropriately changing the size of each part.

It is a side view of the high frequency induction heating apparatus which concerns on one Embodiment of this invention. FIG. 2 shows a cross-sectional shape of a high frequency induction heating coil used in the high frequency induction heating apparatus of FIG. 1. It is a front view of the side plate used for the high frequency induction heating apparatus of FIG. It is sectional drawing which shows the hardening hardening layer obtained when a shaft part is induction-heated by high frequency induction heating with the high frequency induction heating apparatus of FIG. It is a figure which shows the conventional high frequency induction heating apparatus. FIG. 5A is a front view of a conventional high-frequency induction heating apparatus, and FIG. 5B is a side view of the conventional high-frequency induction heating apparatus. It is a perspective view which shows notionally a high frequency induction heating coil. It is sectional drawing which shows the hardening hardening layer obtained when a shaft part is induction-heated by the high frequency induction heating coil of FIG. It is sectional drawing of the high frequency induction heating coil used for the conventional high frequency induction heating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High frequency induction heating apparatus 2 High frequency induction heating coil 3 Lead conductor for feeding 3a Lead conductor for feeding on the leading side 3b Lead conductor for feeding on the return side 7a, 7b Side plate 8a, 8b Pipe material 9a, 9b Silicon steel material 14 Shaft portion 15 Through Hole

Claims (5)

  Under the state where the semi-open saddle type high frequency induction heating coil arranged between a pair of side plates facing each other is placed on a narrow shaft portion having a width of 17 mm to 22 mm to be heated with a gap therebetween, In the high-frequency induction heating apparatus in which the shaft portion is subjected to high-frequency induction heating while causing the half-open saddle type high-frequency induction heating coil to follow the shaft portion, the half-open saddle type high-frequency induction heating coils are parallel to each other. The facing distance between a pair of coil portions that are disposed opposite to each other and are opposed to the surface to be heated of the shaft portion and having the same width is wider than the length dimension along the facing direction of the pair of coil portions. A high frequency induction heating device characterized by being set.   When the width of the shaft portion is 18 mm, the overall width in the opposing direction of the pair of coil portions is 13 mm, the width of the coil portions is 4 mm, and the length of the coil portions is 8 mm. The high-frequency induction heating apparatus according to claim 1, wherein an interval between the pair of coil portions is 5 mm.   The high frequency induction heating device according to claim 1 or 2, wherein a part of the outer periphery of the coil portion is encapsulated with a silicon steel material.   The high frequency induction heating device according to claim 3, wherein a part of the outer periphery of the coil portion encapsulated by the silicon steel material is an entire portion excluding a surface facing the shaft portion.   A part of the side plate that holds the high-frequency induction heating coil and the power-feeding lead conductor connected to the high-frequency induction heating coil, and the lead-side power feeding lead conductor and the return-side power feeding lead conductor; A high frequency induction heating apparatus characterized in that a through hole is formed at a position closest to or near the position.

Images