JP4292143B2 - Semi-open saddle type high frequency induction heating coil - Google Patents

Description

  The present invention relates to a semi-open saddle type high-frequency induction heating coil used when induction-hardening a cylindrical object to be heated such as a pin part or a journal part of a crankshaft for a gasoline engine or a diesel engine, for example. The present invention relates to a semi-open saddle type high frequency induction heating coil having a simple structure capable of performing efficient high frequency induction heating when the object to be heated is narrow.

  FIG. 4 shows a crankshaft 1 used in a 4-cylinder gasoline engine or a diesel engine. The crankshaft 1 has four pin portions 2, five journal portions 3, and a counterweight portion 4 provided therebetween. Usually, a hardened hardening layer H as shown in FIG. 5 is formed on the cylindrical outer peripheral surface 2a of the pin portion 2 of the crankshaft 1 by, for example, induction hardening. Although not shown, a hardened and hardened layer substantially similar to the hardened and hardened layer H of the pin portion 2 is also formed on the cylindrical outer peripheral surface 3a of the journal portion 3 of the crankshaft 1 by, for example, induction hardening. .

  FIG. 6 shows an induction hardening apparatus 5 that has been conventionally used to form the hardened hardening layer H as described above. As shown in FIG. 6, the induction hardening device 5 includes a pair of side plates 6, 6 arranged opposite to each other in parallel, and a half-open saddle type high frequency induction heating coil provided between the side plates 6, 6. 7, a high-frequency power source 9 for supplying a high-frequency current to the semi-open saddle type high-frequency induction heating coil 7 through power supply lead conductors 8 and 8, and the high-frequency power source 9 and power supply lead conductors 8 and 8 are connected. Connection terminals 10, 10, a block 11 made of an insulating material attached to the top of the side plates 6, 6 to hold the connection terminals 10, 10 and the power supply lead conductors 8, 8, and a heated object 12 For example, a plurality of (three in the case of FIG. 4) ceramics or superstructures for maintaining a predetermined gap between the cylindrical outer peripheral surface 2a of the pin part 2 and the semi-open saddle type high frequency induction heating coil 7 Hard alloy contactor (chip member) 14, And 4, 14, and a like cooling liquid injection means 15 and 15 for quenching cooling attached to the lower end portions of the pair of side plates 6, 6 in the lower part of the semi-open saddle type high frequency induction heating coil 7.

  As shown in FIG. 7, the semi-open saddle type high frequency induction heating coil 7 in the induction hardening device 5 described above is connected to the upper half portion of the cylindrical outer peripheral surface 12a of the heated body 12 via the contacts 14, 14, 14. A semi-opened saddle type (substantially semi-circular arc shape in a side view) coil head 7a disposed to face each other at a predetermined interval is provided. The coil head 7a includes two identical heating conductors 16 and 16 that are electrodes arranged opposite to each other along the width direction (axial direction) of the body 12 to be heated, and a magnetic flux concentrating member that surrounds them. It consists of magnetic bodies (magnetic flux concentrating members) 17 and 17. The heating conductors 16 and 16 are made of, for example, a hollow pipe member having a rectangular cross section arranged parallel to each other as shown in the figure, and these are connected in series with each other by a connection conductor (not shown). Of the heating conductors 16, 16, the surface portions S, S (see FIG. 7) disposed opposite to the cylindrical outer peripheral surface 12 a of the body to be heated 12 are exposed to the outside at the surface portions P, P of the magnetic flux concentration magnetic bodies 17, 17. Exposed.

The magnetic flux concentrating magnetic bodies 17 and 17 are for increasing the heating efficiency, and are composed of, for example, a silicon steel plate or a dust core. As shown in FIG. 7, the total width W ₁ of the coil head portion 7a substantially corresponds to the width W ₂ of the hardened and hardened layer H shown in FIG. 5 (W ₁ ≈W ₂ ). is set slightly narrower than the width (pin width of the pin 2 _{axial) W 3 (W 1 <W} 3).

JP-A-2002-226919 (Patent Document 1) is known as a known technique related to the semi-open saddle type high frequency induction heating coil 7 described above.
JP 2002-226919 A

As shown in FIG. 8, in the case of a general arrangement of the heating conductors 16 and 16 of the coil head portion 7a, in the present specification, for convenience, the inner side surfaces of the pair of heating conductors 16 and 16 are referred to as the coil inner surface M, M is referred to as the outer surface of the coil is referred to as coil outer surfaces N and N, the outer diameter is referred to as coil outer diameter D ₁ , and the inner diameter is referred to as coil inner diameter D ₂ . 9 and 10 show the positional relationship between the heating conductors 16 and 16 and the magnetic flux concentrating magnetic bodies 17 and 17 surrounding them, respectively. The portions 17a and 17a on the coil inner surfaces M and M side in the coil head portion 7a in FIG. 10 are formed thicker than the portions 17a and 17a on the coil inner surfaces M and M side in the coil head portion 7a shown in FIG. . The thicker the portions 17a and 17a (that is, the larger the volume), the better the heating efficiency. When the pin width W ₃ of the pin portion 2 is relatively wide as shown in FIG. 7, the thickness t ₀ of the coil inner surfaces M and M portions 17a and 17a can be increased as shown in FIG. If the dimensions of the pin width W ₃ is narrow, it can not be made thicker coil inner surface M, the portion 17a of the side of M, the thickness t ₀ of 17a as shown in FIG. 10.

On the other hand, the crankshaft 1 used in recent reciprocating engines has been shortened due to the demand for a more compact engine. For this reason, the width dimension (the width in the axial direction) of the pin portion 2 and the journal portion 3 is reduced, and the thickness t ₀ of the portions 17a and 17b on the coil inner surfaces M and M side is sufficiently increased as described above. However, there is a problem that the heating efficiency is lowered (see FIG. 11).

  The present invention has been made to solve the above-described problems, and its object is to provide a heated object having a narrow width such as a pin part or a journal part of a crankshaft, for example. Another object of the present invention is to provide a semi-open saddle type high frequency induction heating coil which can efficiently perform high frequency induction heating and can improve durability.

In order to achieve the above-described object, in the present invention, one half of the object to be heated is arranged opposite to the cylindrical outer peripheral surface of the object to be heated in order to subject the object to be heated (having a short dimension in the axial direction) to high frequency induction heating. The open saddle type high frequency induction heating coil includes two heating conductors arranged opposite to each other along the width direction of the object to be heated, and a magnetic flux concentration magnetic body surrounding each of the two heating conductors. A coil head, and the two heating conductors are configured to have a cross-sectional shape that inclines in a direction that widens the distance from the coil inner diameter side toward the coil outer diameter side, and for the magnetic flux concentration. In the magnetic body, the width dimension on the outer diameter side of the coil at the location where the two heating conductors face each other is made thicker than the width dimension on the inner diameter side of the coil , whereby the two heating elements of the magnetic substance for concentration of magnetic flux are heated. The inner side of the conductor coil It has a volume of a portion to increase significantly by the amount obtained by tilting the two heating conductors.
Moreover, in this invention, the said coil head is arrange | positioned corresponding to the cylindrical outer peripheral surface of the said to-be-heated body whose width | variety of an axial direction is 12.0 mm-55.0 mm.

The present invention according to claim 1 comprises two heating conductors arranged opposite to each other along the width direction of the object to be heated, and a magnetic flux concentrating magnetic body surrounding each of the two heating conductors. A coil head, and the two heating conductors are configured to have a cross-sectional shape that inclines in a direction that widens the distance from the coil inner diameter side toward the coil outer diameter side, and for the magnetic flux concentration. In the magnetic body, the width dimension on the outer diameter side of the coil at the location where the two heating conductors face each other is made thicker than the width dimension on the inner diameter side of the coil , whereby the two heating elements of the magnetic substance for concentration of magnetic flux are heated. Since the volume of the portion on the coil inner surface side of the conductor is greatly increased by the inclination of the two heating conductors, even a narrow object to be heated is arranged opposite to this. The magnetic substance for concentrating the magnetic flux Since the magnetic flux concentrating magnetic body on the coil outer diameter side is thicker than the coil inner diameter side, the current flowing on the coil inner diameter side can be increased. Moreover, since the cancellation of magnetic flux due to mutual interference of the heating conductors on the coil outer diameter side can be reduced, the object to be heated can be efficiently induction-heated at high frequency, and the durability of the semi-open saddle type high-frequency coil can be improved. Can be achieved.

  In the present invention according to claim 2, the coil head is arranged corresponding to the cylindrical outer peripheral surface of the heated body having an axial width of 12.0 mm to 55.0 mm. High-frequency induction heating can be efficiently performed at the time of induction hardening of a pin portion or a journal portion of a crankshaft used in a recent reciprocating engine or the like.

  A semi-open saddle type high frequency induction heating coil 20 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3, the same parts as those in FIGS. 4 to 8 are denoted by the same reference numerals, and redundant description is omitted.

The semi-open saddle type high frequency induction heating coil 20 of the present embodiment shown in FIGS. 1 to 3 has a narrow pin portion 2 of the crankshaft 1 (axial width (pin width) W ₃ is 12.0 mm to 55. 0 mm) for high-frequency induction heating for quenching, and the coil head 20a of the semi-open saddle type high-frequency induction heating coil 20 faces the cylindrical outer peripheral surface 2a of the pin portion 2 during high-frequency induction heating. It is arranged. The support mechanism and power feeding mechanism of the half-open saddle type high frequency induction heating coil 20 are the same as the mechanism shown in FIG.

As shown in FIG. 1, the half-open saddle type high frequency induction heating coil 20 has a pair of power supply lead conductors 8, 8 connected at one end to a high frequency power source, and the other end of the power supply lead conductors 8, 8. The coil head 20a is connected to the coil head 20a, and magnetic flux concentrating magnetic bodies 17 and 17 are attached to the coil head 20a and surround the coil head 20a. As shown in FIG. 2, the coil head 20a described above is composed of heating conductors 21 and 21 that are two electrodes, and these heating conductors 21 and 21 are shown in FIGS. In this way, they are arranged in parallel with each other at a predetermined interval, and are connected in series with each other via a connection conductor (not shown). On the other hand, the magnetic bodies 17 and 17 for concentrating magnetic flux are members formed by stacking a large number of plate-like magnetic materials.

As shown in FIGS. 2 and 3, the two heating conductors 21 and 21 described above are inclined so as to widen the distance from the coil inner diameter side β and β toward the coil outer diameter side α and α. It is comprised so that it may have a cross-sectional shape like a parallelogram. On the other hand, in the magnetic flux concentrating magnetic bodies 17, 17, the width dimension t ₁ of the coil outer diameter side α, α is the width dimension t of the coil inner diameter side β, β at the location where the two heating conductors 21, 21 face each other. _It is thicker than ₂ .

The heating conductors 21 and 21 correspond to the cylindrical outer peripheral surface 12a of the narrow body to be heated 12 (that is, the cylindrical outer peripheral surface 2a of the pin portion 2), and the width dimension of the coil head 20a. L (see FIG. 3) is limited by corresponding to the width W ₃ of the pin 2 is heated body 12 (see FIG. 7). Therefore, when the heating conductors 21 and 21 have rectangular cross-sectional shapes (heating conductors 16 and 16) arranged in parallel as shown in FIG. 11, the coils of the magnetic bodies 17 and 17 for concentrating magnetic fluxes. The thickness t ₀ of the inner surface M, M side portion 17a, 17a is a constant dimension (same dimension) in both the coil inner diameter side portion and the coil outer diameter side portion, and as described above, it is possible to make it thicker than the illustrated dimensions. Can not.

On the other hand, since the heating conductors 21 and 21 of the half-open saddle type high frequency induction heating coil 20 of the present embodiment are configured to have a parallelogram-shaped cross section inclined as described above, FIG. As shown in FIG. 4, the thickness t ₁ of the coil outer diameter side α, α of the magnetic flux concentrating magnetic bodies 17, 17 surrounding the heating conductors 21, 21 can be made larger than the thickness t ₂ of the coil inner diameter side β, β. (T ₁ > t ₂ ). For this reason, it is possible to make the total volume of the portions on the coil inner surfaces M, M side of the magnetic flux concentrating magnetic bodies 17, 17 (portions 17b, 17b shown by cross-hatching in FIG. 3) significantly larger than the conventional one. it can. That is, the volume of the portions 17b and 17b on the coil inner surface side of the two heating conductors 21 and 21 in the magnetic flux concentrating magnetic bodies 17 and 17 is greatly increased by the amount of inclination of the two heating conductors 21 and 21. be able to.

In the coil head 20a shown in FIG. 3, the angle θ formed by the surfaces 21a and 21a where the pair of heating conductors 21 and 21 face each other is set to 25 °, for example. However, the angle θ is not limited to 25 °, and can be changed as appropriate. Further, the widths of the surface portions S and S of the pair of heating conductors 21 and 21, that is, the surface portions S and S exposed from the magnetic flux concentrating magnetic bodies 17 and 17 and corresponding to the object to be heated are T _1. the surface S, and the distance between S and _{T 2, T 2 = T 1} × K ( where the constant of K = 0.5 to 1.5) is set to be. For example, when the T ₁ to 4.0mm is, T ₂ is set to 2.0Mm～6.0Mm, when the T ₁ to 8.0mm is, T ₂ is 4.0mm~12.0mm Set to

  Table 1 below shows a comparison between a conventional coil (conventional product) and a coil of the present invention (product of the present invention), and heating such as coil damage according to heating power, heating time, and heating power amount. Comparison data for items related to efficiency is shown. In addition, the data described in Table 1 below is comparative data for the same quenching depth.

As shown in Table 1 above, it can be seen that the product of the present invention is reduced in all points of heating power, heating time, and coil loss as compared with the conventional product, and a significant improvement in heating efficiency is ensured. Further, when the heating time is the same, the heating power can be further reduced. The ratio base to the product of the present invention with conventional products, increases the coil circumference of the coil outer diameter side α is, the current flowing through the coil inner diameter side β with high frequency current flowing through that portion is reduced to increase accordingly Therefore, the heating efficiency can be improved. In addition, the effect of canceling the magnetic flux due to the mutual interference between the coils is reduced due to the expansion of the coil interval on the coil outer diameter side α, so that the heating efficiency can be further improved. From the above, it is possible to shorten the heat treatment time (heating time and cooling time), and since the need to power amount is small and it is possible to reduce the La running costs.

  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 above-described embodiment, the semi-open saddle type high frequency induction heating coil 20 used for high frequency induction heating of the pin portion 2 of the crankshaft 1 of an engine such as an automobile has been described. The high-frequency induction heating coil is not limited to the journal portion 3 of the crankshaft 1 (the journal width in the axial direction is 12.0 mm to 55.0 mm, similar to the pin width of the pin portion 2), as well as other various heated objects. It can be used for induction heating.

It is a front view of the semi-opening saddle type high frequency induction heating coil for a narrow body to be heated according to an embodiment of the present invention. It is an AA line cross section in FIG. It is sectional drawing which expands and shows the coil head of the half open saddle type high frequency induction heating coil of FIG. It is a top view which shows the crankshaft for 4 cylinder engines. It is sectional drawing which shows the hardening hardening layer in the pin part of a crankshaft. It is a front view of the induction hardening apparatus provided with the half open saddle type high frequency induction heating coil. It is sectional drawing which shows the coil head of the half open saddle type high frequency induction heating coil for performing high frequency induction heating of the pin part of a crankshaft. It is explanatory drawing for demonstrating arrangement | positioning of the heating conductor of a coil head, and the name of each part. It is sectional drawing which shows an example of the coil head part of the conventional half open saddle type high frequency induction heating coil. It is sectional drawing which shows the coil head of the conventional half open saddle type | mold high frequency induction heating coil with the thickness of the part of the coil inner surface side of the magnetic body for magnetic flux concentration being thick. It is sectional drawing which shows the coil head of the conventional semi-opening saddle type high frequency induction heating coil applied to a narrow cylindrical heated body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crankshaft 2 Pin part 2a Cylindrical outer peripheral surface 3 Journal part 3a Cylindrical outer peripheral surface 5 Induction hardening apparatus 12 Heated body 12a Cylindrical outer peripheral surface 17 Magnetic substance 20 for concentrating magnetic flux Semi-open saddle type high frequency induction heating coil 20a Coil Head 21 Heating conductor α Coil outer diameter side β Coil inner diameter side M Coil inner surface N Coil outer surface

Claims (2)

In one half-open saddle type high frequency induction heating coil arranged to oppose the cylindrical outer peripheral surface of the heated body for high frequency induction heating of the narrow heated body, facing each other along the width direction of the heated body A coil head composed of two heating conductors and a magnetic flux concentrating magnetic body surrounding each of the two heating conductors, the two heating conductors from the inner diameter side of the coil to the outside of the coil. The magnetic substance for concentrating the magnetic flux is formed on the outer diameter side of the coil at a location where the two heating conductors face each other. By making the width dimension thicker than the width dimension on the coil inner diameter side, the volume of the portion of the magnetic flux concentrating magnetic body on the coil inner surface side of the two heating conductors is inclined to the two heating conductors. Greatly increased by Semi-open saddle type high frequency induction heating coil, characterized in that the the like.   The semi-opened saddle type according to claim 1, wherein the coil head is disposed corresponding to a cylindrical outer peripheral surface of the heated body having an axial width of 12.0 mm to 55.0 mm. High frequency induction heating coil.

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