JP3856773B2 - High frequency induction heating coil with stepped shaft - Google Patents

Description

  The present invention relates to a high-frequency induction heating coil of a stepped shaft-shaped member, and in particular, for example, a CVJ (constant velocity joint) of an automobile, that is, a stepped shaft-shape employed as a component such as an outer race or an inboard joint of a constant velocity joint. The present invention relates to a heating coil for high-frequency induction heating of a stepped shaft-shaped member capable of stably forming a prescribed hardened layer on the outer peripheral portion of the stepped shaft-shaped member upon induction hardening of the member.

  The target stepped shaft-shaped member, for example, an outer race of a constant velocity joint, an inboard joint, or the like is made of a metal material, particularly an iron-based material, and has a stepped shaft-shaped member having a shape as shown in FIG. 1 is used. This stepped shaft-shaped member 1 is a single step formed integrally with a small-diameter shaft portion 2 having a relatively small diameter and a base end portion 3 as shown in the drawing, and has a large diameter having a relatively large diameter. It consists of a radial shaft part 4. A shoulder portion 5 is formed at the base end portion 3 of the small diameter shaft portion 2 as shown in the figure, and an arcuate portion 6 is formed between the shoulder portion 5 and the outer peripheral surface of the large diameter shaft portion 4. .

  The illustrated stepped shaft-shaped member 1 includes the small-diameter shaft portion 2 and one large-diameter shaft portion 4 formed integrally with the small-diameter shaft portion 2, but adjacent to the large-diameter shaft portion 4, Further, there is a stepped shaft-like member (not shown) in which a large-diameter large-diameter shaft portion is formed in a plurality of stages, and it has been conventionally demanded to perform induction hardening on these shaft-like members.

  As shown in FIG. 1, it is required that a hardened layer 7 by quenching as shown in the figure is formed on the outer periphery of the stepped shaft-like member 1, and the hardened layer 7 has a hardened layer depth. For each surface hardness, a heat treatment standard value is provided.

Various known techniques are already available as a high-frequency induction heating coil for forming the hardened layer 7 by induction hardening on the outer periphery of the stepped shaft-shaped member 1.
Japanese Utility Model Publication No. 55-80358 JP 2002-180128 A JP 2002-180129 A

  Further, the present applicant has already developed the high-frequency induction heating coil 31 shown in FIG. As shown in FIG. 6, the high frequency induction heating coil 31 is connected to one end on the current output side of the high frequency power supply unit 8 so that the proximal end portion 3 of the small-diameter shaft portion 2 of the stepped shaft-shaped member 1 is substantially half. A semi-annular induction heating conductor 32 arranged so as to surround an annular shape (at a central angle of 120 ° to 140 °), and parallel to the central axis X0 of the stepped shaft-like member 1 through the connecting conductor from the end thereof. Along the small-diameter shaft portion 2, the linear heating conductor 33 arranged toward the tip end side thereof is connected to the end portion of the linear heating conductor 31, and the tip end side of the small-diameter shaft portion 3 is substantially semicircularly enclosed. A semi-annular heating conductor 34 arranged in this manner, and a straight line arranged from the end of the semi-annular heating conductor 34 toward the base end 3 of the small-diameter shaft portion 2 in parallel to the linear heating conductor 33. A heating conductor 35 and a proximal end portion 3 of the small-diameter shaft portion 2 connected to the end portion of the heating conductor 35 The semicircular heating conductor 36 is disposed so as to surround the semicircular ring and is connected to the other end on the output side of the high frequency power supply unit 8.

  FIG. 7 shows various conditions related to induction hardening in which the stepped shaft-like member 1 is rapidly cooled at the outer peripheral portion thereof after high-frequency induction heating by the high-frequency induction heating coil 31, and formed on the outer peripheral portion thereby. 3 is a cross-sectional view showing a hardened and hardened layer 37. FIG.

  However, as shown in FIG. 7, the hardened and hardened layer 37 formed using the high-frequency induction heating coil 31 satisfies the heat treatment standard value for the portion of the small-diameter shaft portion 2, Unlike the hardened layer 7 shown in FIG. 1, the hardened layer 37 for the base end 3 and the shoulder 5 is formed in a non-uniform form. Further, the arc-shaped portion 6 has a problem that the hardened layer 37 is not formed at all.

  On the other hand, the “surface hardening coil body by high frequency induction” disclosed in Japanese Utility Model Laid-Open No. 55-80358 of Patent Document 1 mainly sets the hardened layer in the vicinity of the shoulder portion 5 of the shaft-shaped member 1 to a normal form. Therefore, unlike the present invention, a hardened and hardened layer according to the standard cannot be formed on the shoulder portion 5 and the arc-shaped portion 6.

On the other hand, the “high frequency induction heating coil” disclosed in Japanese Patent Application Laid-Open Nos. 2002-180128 and 2002-180129 of Patent Documents 2 and 3 includes a small-diameter shaft portion 2, a shoulder portion 5, and a stepped shaft-shaped member 1. The shape of a high-frequency induction heating coil that forms a good hardened and hardened layer on the arc-shaped portion 6 is disclosed. The overall shape of the high-frequency induction heating coil is considerably complicated, and the first step heating is performed. There is a limitation on the center angle θ1 of the arc of the conductor (39) and the center angle θ2 of the arc of the second step heating conductor (41), respectively, which makes it difficult to manufacture a high-frequency induction heating coil and is expensive. There was a point.
Further, the third small-diameter shaft heating conductor (36) is inclined and connected to the connecting conductors (37) and (38) and the second small-diameter shaft heating conductor (35) connected thereto. The heating conductors (43) and (42) are also complicatedly bent and connected to the second stepped heating conductor (41), resulting in an expensive structure.

The present invention has been made in view of the foregoing, the purpose is to solve the above problems, the hardened layer by high-frequency induction hardening of the standard as instructed is formed, productivity is good stepped high frequency induction heating coil An object of the present invention is to provide a high-frequency induction ripening coil of a shaft-shaped member.

In order to achieve the above object, the structure of the present invention includes a small-diameter shaft portion having a relatively small diameter, and a single step or a plurality of steps formed integrally with the base end portion, and gradually and gradually. A large-diameter shaft portion having a large diameter, a shoulder portion at a connection portion between the small-diameter shaft portion and the large-diameter shaft portion or a connection portion between the adjacent large-diameter shaft portions, the shoulder portion and the A high-frequency induction heating coil for forming a hardened layer by high-frequency induction quenching on an outer peripheral portion of a stepped shaft-like member formed with an arc-shaped portion formed between the outer periphery of a large-diameter shaft portion, The high frequency induction heating coil
(A) One end of each is connected to the output end of the high-frequency power supply unit, and both sides surround the outer periphery of the stepped shaft-shaped member on the tip end side of the small-diameter shaft portion in a semicircular shape through a certain interval. Two arcuate heating conductors arranged as follows:
(B) One end of each of the two arc-shaped heating conductors is connected to the other end of the two arc-shaped heating conductors, and the stepped shaft-shaped member extends along the outer periphery via a space on the outer peripheral side of the small-diameter shaft portion. Two linear heating conductors arranged parallel to the central axis direction;
The other end of each of (c) the two linear heating conductors are each one end connected and via the proximity to the shoulder intervals in the proximal portion of the small-diameter shaft portion, semicircular Two first semi-annular heating conductors arranged to surround
(D) two connecting conductors , each of which is connected to the other end of each of the two first semi-annular heating conductors and bent at 90 °;
(E) The other end of each of the two connection conductors is connected to one end thereof and the other end at a position 180 degrees apart from the one end with respect to the central axis, and is adjacent to the arcuate portion. through some distance, are arranged annularly so as to surround the arc-shaped portion, and a stepped shaft-like member made of an annular heating conductor according to the two second semi-annular heating conductors that will be formed in parallel circuit with each other A high frequency induction heating coil.

  With this configuration, the high-frequency induction ripening coil of the present invention is shaped as described above so that the center axis X0 of the stepped shaft-like member coincides with the center axis X of the ripening coil, When the shaft-shaped member is rotated around the central axis X while the shaft-shaped member is high-frequency induction heated by the high-frequency induction ripening coil, the shaft-shaped member is stopped and rapidly cooled. In addition to the outer periphery of the small-diameter shaft portion, a hardened layer having a shape and hardness in accordance with the heat treatment standard can be stably and reliably formed not only on the shoulder portion, particularly on the arc-shaped portion. Further, the shape of the high-frequency induction heating coil is also made compact compared to the prior art, the productivity is good, and it can be manufactured at a relatively low cost.

According to a second aspect of the present invention, each of the two arc-shaped heating conductors is a stepped shaft-shaped high-frequency induction ripening coil having a 90 ° arc around the central axis.
With this configuration, the high-frequency induction heating coil can be manufactured with higher productivity and at lower cost.

The high-frequency induction ripening coil of the stepped shaft-shaped member of the present invention, as described above, is a first semi-annular made of the two arc-shaped heating conductors so as to conform to the shape of the stepped shaft-shaped member. Since it consists of a heating conductor, the two linear heating conductors, the two second semi-annular heating conductors, the two connecting conductors, and the annular heating conductor, by high-frequency induction quenching according to standard instructions In addition to the formation of a hardened layer, there is an excellent effect that the productivity of the high frequency induction heating coil is extremely improved.

The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a form after quenching of a stepped shaft member as an object to be induction hardened by the high frequency induction heating coil of the present invention.

  In FIG. 1, a stepped shaft-shaped member 1 which is a to-be-hardened member for forming a hardened layer 7 by desired hardening by a high-frequency induction heating coil of the present invention is made of a metal material, particularly an iron-based material, A small-diameter shaft portion 2 that is elongated and has a relatively small diameter, and a large-diameter shaft portion 4 that is integrally formed with the base end portion 3 and has a relatively large diameter. A stepped shoulder portion 4 is formed at the base end portion 3 of the small diameter shaft portion 2, and an arcuate portion 6 is formed between a corner portion of the shoulder portion 5 and an outer peripheral end portion of the large diameter shaft portion 4. Is formed. And the thing of the form shown by the hatching of the same figure as said hardened layer 7 is desired. Note that X0 in FIG. 1 is the central axis of the stepped shaft-like member 1.

  2 and 3 are diagrams showing Example 1 of the high-frequency induction heating coil of the stepped shaft-shaped member of the present invention, and FIG. 2 shows the heating conductor of the high-frequency induction heating coil of the stepped shaft-shaped member of the present invention. FIG. 3 is a schematic perspective view showing the arrangement structure, and FIG. 3 is a diagram showing quenching conditions by the high-frequency induction heating coil shown in FIG. 2 and a hardened layer formed on the stepped shaft member and the shaft member. FIG. 2 and 3 is the central axis of the high frequency induction heating coils 11 and 21. In FIG.

The high-frequency induction heating coil 11 shown in FIG. 2 has the small-diameter shaft portion 2 of the stepped shaft-shaped member 1, the base end portion 3, the shoulder portion 5, The arcuate part 6 is used for high-frequency induction heating, and is a conductive part composed of a continuous coil structure for conducting high-frequency current.
Reference numeral 8 denotes a high-frequency power source, which outputs a current to be passed through the high-frequency induction heating coil 11 (21, 31) at a frequency of 1 kHz to 100 kHz (in some cases up to 400 kHz). The arrow direction in FIG. 2 is the direction of current.

The high-frequency induction heating coil 11 includes two arc-shaped heating conductors 12a and 12b each made of an arc-shaped heating conductor, two linear heating conductors 13a and 13b, and two first semi-annular heating conductors 14a and 14b, It consists of two connecting conductors 16a and 16b and two annular semicircular heating conductors 15a and 15b, and an annular heating conductor 15 connected to each other in series, and a series of conductors having substantially the same diameter. The coil is formed.

  That is, the two arc-shaped heating conductors 12a and 12b, each formed of an arc-shaped heating conductor, are connected to the respective terminals at the output end of the high-frequency power supply unit 8 by connecting conductors 12c and 12d. The two arc-shaped heating conductors 12a and 12b are spaced apart from each other by an outer periphery of the stepped shaft-like member 1 on the distal end side of the small-diameter shaft portion 2, that is, in the vicinity of the end portion of the small-diameter shaft portion 2. And are arranged so as to be surrounded by a semicircular shape on both sides. Each of the two arc-shaped heating conductors 12a and 12b is formed so that a central angle about the central axis X of the small-diameter shaft portion 2 is about 90 °. Accordingly, the two arcuate heating conductors 12a and 12b can be formed in a 180 °, ie semicircular shape. For this reason, power is supplied from the substantially center position of the semicircular ring by the two arc-shaped heating conductors 12a and 12b.

  On the outer peripheral side of the small-diameter shaft portion 2, the two linear heating conductors 13 a and 13 b are arranged along the outer periphery with a certain interval in parallel with the central axis X direction of the small-diameter shaft portion 2. From the vicinity of the end portion to the vicinity of the base end portion 3. One end of each of the two linear heating conductors 13a and 13b is connected to the other end of each of the two arcuate heating conductors 12a and 12b.

  The other end of each of the two linear heating conductors 13a and 13b is opposed to and close to the shoulder 5 of the small-diameter shaft portion 2 through an interval in the base end portion 3. Two first semi-annular heating conductors 14a and 14b are arranged so as to surround the end 3 in a semicircular shape (circular shape on both sides). One end of each of the two first semi-annular heating conductors 14a and 14b is connected to the other end of each of the two linear heating conductors 13a and 13b.

  Next, two second semi-annular rings are formed in an annular shape so as to surround the arc-shaped portion 6 with a space in the arc-shaped portion 6 facing and close to the arc-shaped portion 6 of the small-diameter shaft portion 2. An annular heating conductor 15 composed of the heating conductors 15a and 15b is arranged. Then, one end (connection point) 15c of the annular heating conductor 15 and the other end (connection point) 15d at a position 180 ° apart from the one end 15c with respect to the central axis line X are approximately 90 °. The bent connection conductors 16a and 16b are connected to the other ends of the two first semi-annular heating conductors 14a and 14b, respectively. Since each of the two second semi-annular heating conductors 15a and 15b of the annular heating conductor 15 forms a parallel circuit, the current flowing through each of the second semi-annular heating conductors 15a and 15b is: The current flows through each of the two second semi-annular heating conductors 14a and 14b.

Therefore, as shown in FIG. 2, the path of the current flowing through the high-frequency induction heating coil 11 is from one output terminal of the high-frequency power supply unit 8 to one arcuate heating conductor 12a via the connection conductor 12c. The linear heating conductor 13a, one of the first semi-annular heating conductors 14b , the connecting conductor 16b , the second semi-annular heating conductors 15a, 15b connected in parallel, and the connecting conductor 16a , a path that reaches the other output terminal of the high-frequency power source through the other first semi-annular heating conductor 14a , the other linear heating conductor 13b, the other arc-shaped heating conductor 12b, and the connection conductor 12d. .

First, formation of the hardened layer 7 of the stepped shaft-like member 1 when the high-frequency induction heating coil 11 of FIG. 2 is used will be described.
FIG. 3 shows the quenching condition of the stepped shaft-like member 1 by the high-frequency induction heating coil 11 having the structure of FIG. 2 and the formation state of the hardened layer 7 thereby. As shown in FIG. 3, the quenching conditions for this assortment include frequency (kHz), voltage (V, effective value), current (A, effective value), current output (kW), heating time (sec), air cooling Time (sec), cooling time (sec), quenching water (Yukon), quenching water concentration (%), quenching water temperature (° C), quenching water flow rate (l / min), coil gap (mm), etc. Values are shown. Of course, the values shown are merely examples, and the present invention is not limited to these values.

  When induction hardening is performed under the above conditions, a hardened layer 7 as shown in FIG. 3 is formed on the shaft-shaped member 1. In this case, it can be seen that the hardened layer 7 is also formed on the small-diameter shaft portion 2, the shoulder portion 5, and the arc-shaped portion 6, and a result satisfying the standard value is obtained.

  Next, FIG. 4 and FIG. 5 are diagrams showing Example 2 of the high-frequency induction heating coil of the stepped shaft-shaped member of the present invention, and FIG. 4 shows the high-frequency induction heating coil of the stepped shaft-shaped member of the present invention. FIG. 5 is a schematic perspective view showing an arrangement structure of heating conductors, FIG. 5 is a diagram showing quenching conditions by the high-frequency induction heating coil shown in FIG. 4, and a hardened layer formed on the stepped shaft-like member thereby, It is sectional drawing of a shaft-shaped member. 4, the same members as those shown in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted.

  The high-frequency induction ripening coil 21 shown in FIG. 4 has the same basic structure as that shown in FIG. 2, but the two second semi-annular shapes that form the semicircular heating conductor 15 shown in FIG. Of the heating conductors 15a and 15b, one of the second semi-annular heating conductors 15a is cut and deleted, and only the other one of the second semi-annular heating conductors 15b is configured. Accordingly, the other second semi-annular heating conductor 15b is directly connected in series at the ends (connection points) 15c and 15d.

For this reason, the annular heating conductor 15 in FIG. 2 is only the other second semi-annular heating conductor 15b, and no parallel circuit is formed. The current flowing through the annular heating conductor 15b is the same as the current flowing through the first semi-annular heating conductors 14a and 14b.
The high-frequency induction ripening coil 21 of the present embodiment has a structure in which the annular heating conductor 15 in FIG. 2 is constituted by one second semi-annular heating conductor 15b in FIG. Compared to the heating coil 11, the length of the coil can be reduced.

  FIG. 5 shows the quenching conditions of the stepped shaft-like member 1 by the high-frequency induction ripening coil 21 having the above-described current flow with the structure shown in FIG. 4 and the formation state of the hardened layer 7 thereby. As a result, a hardened layer 7 that satisfies the standard value as in the case of FIG. 3 can be obtained.

  Note that the technology of the present invention is not limited to the technology in the above-described embodiment, and may be implemented by means of other modes that perform the same function, and the technology of the present invention may be variously modified within the scope of the above-described configuration. Can be added.

It is an axial sectional view showing the form after quenching of the stepped shaft-shaped member induction-hardened by the high-frequency induction heating coil of the present invention. It is a typical perspective view which shows the arrangement structure of the heating conductor of the high frequency induction heating coil of Example 1 of this invention. FIG. 3 is a chart and a shaft cross-sectional view showing an example of quenching conditions by the high-frequency induction heating coil shown in FIG. 2 and an example of a hardened layer formed on the stepped shaft member. It is a typical perspective view which shows the arrangement structure of the heating conductor of the high frequency induction heating coil of Example 2 of this invention. FIG. 5 is a chart and an axial cross-sectional view showing an example of quenching conditions by the high-frequency induction heating coil shown in FIG. 4 and an example of a hardened layer formed on the stepped shaft-like member. It is a typical perspective view which shows an example of the arrangement structure of the ripening conductor of the conventional high frequency induction heating coil. FIG. 7 is an axial cross-sectional view showing quenching conditions by the conventional high-frequency induction heating coil shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stepped shaft-shaped member 2 Small diameter shaft part 3 Base end part 4 Large diameter shaft part 5 Shoulder part 6 Arc part 7 Hardened layer 8 High frequency power supply part 11, 21, 31 High frequency induction heating coil 12a, 12b Arc shaped heating conductor 12c, 12d, 16a, 16b Connecting conductors 13a, 13b Linear heating conductors 14a, 14b First semi-annular heating conductor 15 Circular heating conductors 15a, 15b Second semi-annular heating conductors 15c, 15d End (connection point)
X, X0 center axis

Claims (2)

It consists of a small-diameter shaft portion having a relatively small diameter and a single-stage or multiple-stage large-diameter shaft portion having a relatively large diameter that is formed stepwise and gradually. And a connecting portion between the small-diameter shaft portion and the large-diameter shaft portion or a connecting portion between the adjacent large-diameter shaft portions is formed between the shoulder portion and the outer periphery of the large-diameter shaft portion. A high-frequency induction heating coil for forming a hardened layer by high-frequency induction quenching on the outer periphery of a stepped shaft-shaped member formed with an arc-shaped part, the high-frequency induction heating coil,
(A) One end of each is connected to the output end of the high-frequency power supply unit, and both sides surround the outer periphery on the tip end side of the small-diameter shaft portion of the stepped shaft-shaped member in a semicircular shape through a certain interval. Two arcuate heating conductors arranged as follows:
(B) One end of each of the two arc-shaped heating conductors is connected to the other end of the two arc-shaped heating conductors, and the stepped shaft-shaped member is formed along the outer periphery via a space on the outer peripheral side of the small-diameter shaft portion. Two linear heating conductors arranged parallel to the central axis direction;
(C) One end of each of the two linear heating conductors is connected to the other end, and the base end portion of the small-diameter shaft portion is disposed in a semicircular shape adjacent to the shoulder portion with an interval therebetween. Two first semi-annular heating conductors arranged to surround
(D) two connecting conductors , each of which is connected to the other end of each of the two first semi-annular heating conductors and bent at 90 °;
(E) The other end of each of the two connection conductors is connected to one end thereof and the other end at a position 180 degrees apart from the one end with respect to the central axis, and is adjacent to the arcuate portion. through a certain interval, stage, characterized in that it consists disposed annularly so as to surround the arc-shaped portion, and an annular heating conductor according to the two second semi-annular heating conductors that will be formed in parallel circuit with each other High frequency induction heating coil with a shaft-shaped member.   The high frequency induction heating coil for a stepped shaft-shaped member according to claim 1, wherein each of the two arc-shaped heating conductors has a 90 ° arc centering on the central axis.