JP2002047514A - Induction hardening method for crank shaft and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction hardening method for crank shaft and an apparatus therefor with which the hardening treatment of the crank shaft can be performed in a short time and the efficiency of the hardening treatment of the crank shaft can be improved. SOLUTION: During applying the hardening-cooling process for performing hardening and cooling by injecting the cooling liquid for hardening to pin parts 3a-3d after applying the high frequency induction heating to the pin parts 3a-3d of the crank shaft 1, the hardening treatment process is applied to a flange part F at the one end side of the crank shaft 1 or a shaft part S at the other end side of the crank shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of quenching a pin portion of a crankshaft used for a gasoline engine or a diesel engine, etc., and a flange portion at one end of the crankshaft or a shaft portion at the other end of the crankshaft. The present invention relates to an induction hardening method and apparatus for hardening a spline portion or a seal portion).

[0002]

2. Description of the Related Art There are various types of crankshafts used for gasoline engines or diesel engines, and FIG. 4 shows a crankshaft 1 for a four-cylinder engine as an example. This crankshaft 1 is an integrally molded product formed by forging, and as shown in FIG. 4, five journals J1 to J5 extending along the same axis and one between journals adjacent to each other. A total of four pin portions P1 to P4
And a total of eight counterweights K1 to K1 arranged one by one between the pin portion and the journal portion adjacent to each other.
8, a flange portion F integrally formed coaxially with the journal portion 1J at one end, and a shaft portion (spline portion or seal portion) S coaxially formed integrally with the journal portion 5J at the other end. Have.

The pin portions P1 and P4 and the pin portions P2 and P3
Are arranged at positions shifted from each other by 180 °, but their shapes are the same. In FIG. 4, X is a straight line connecting the centers of the journals J1 to J5 and is the rotation center axis (axis) of the crankshaft 1, and Y1 and Y2 are the pins P1, P4, P2, and P3. The central axis (axis).

[0004] In the crankshaft 1 as described above, for example, the pin portion P
1 to P4 and the flange portion F are subjected to induction hardening, and thereafter, the journal portions J1 to J5 are subjected to induction hardening at the second quenching station.
In this case, first, in the first quenching station, the pin portions P1 to P4 of the crankshaft 1 are induction-heated to a required quenching temperature by high-frequency induction and quenched with a quenching coolant, whereby the pin portions P1 to P4 are cooled. After performing the quenching process of ~ P4, the flange portion F of the crankshaft 1 is subjected to high-frequency induction heating to a required quenching temperature and rapidly cooled with a quenching coolant to perform the quenching process of the flange portion F. Like that. Then, at the subsequent second quenching station,
The journal portions J1 to J5 of the crankshaft 1 are quenched.

FIG. 5 shows a pin portion P1 of the crankshaft 1.
1 shows an induction hardening apparatus 2 conventionally used for quenching P4 and the flange portion F. Although not shown, the induction quenching apparatus 2 has a crankshaft rotation drive mechanism for holding the crankshaft 1 as a quenched body (heated body) and rotating the crankshaft 1 about a rotation center axis X. So that the crankshaft 1 is driven to rotate about the rotation center axis X in a state where the rotation center axis X of the crankshaft 1 is horizontally disposed by the crankshaft rotation drive mechanism. Has become.

Further, when the crankshaft 1 is held by the crankshaft rotation drive mechanism, as shown in FIG.
A semi-open saddle-type high-frequency induction heating coil (first high-frequency induction heating coil) 3a,
3b, 3c, 3d (hereinafter simply referred to as heating coils 3a to 3d) are arranged correspondingly as shown in FIGS. These heating coils 3a to 3d are fixed to the lower ends of the power transformers 4a, 4b, 4c and 4d, respectively.
6 and a disk transformer 4a to 4d are integrally connected to each other, and a combined body 5 is attached to a lower portion of the link-type following mechanism 6 as shown in FIG. The heating coils 3a to 3d are supported by the link-type following mechanism 6 in a suspended state. Further, the assembly 7 including the combination 5 and the link-type follow-up mechanism 6 is held movably in the vertical direction by an elevating mechanism (not shown) provided at the pin portion heating station.

On the other hand, the above-mentioned link type follow-up mechanism 6 comprises, for example, a parallelogram link mechanism,
3d is placed on the pins P1 to P4 of the crankshaft 1 and the crankshaft 1
, The heating coil 3a to 3d and the disk transformers 4a to 4d are integrally coupled to each other. Are configured to follow the revolution of each of the pin portions P1 to P4 respectively, and to ascend and descend and swing independently from each other. In addition, the link type following mechanism 6
Is a power supply lead conductor 8 connected to a high-frequency power supply (power matching board) (not shown). The disk transformers 4a to 4d are connected to the power supply lead conductor 8, respectively, and required high-frequency power is supplied to the heating coils 3a to 4d via the power supply lead conductor 8 and the disk transformers 4a to 4d, respectively.
3d.

On the other hand, in this heating station, as shown in FIG. 5, in addition to the heating coils 3a to 3d for heating the pin portion, the flange portion F of the crankshaft 1 is subjected to high frequency induction heating to a required quenching temperature. The second high-frequency induction heating coil 9 (hereinafter simply referred to as heating coil 9) is provided. The heating coil 9 is disposed on one side of a holding position of the crankshaft 1 held by a crankshaft rotation drive mechanism (not shown), and is moved in a horizontal direction by a cylinder (not shown). It is designed to be moved linearly with.

Although not shown, quenching coolant spray jackets are arranged at lower positions corresponding to the pins P1 to P4 and the flange F of the crankshaft 1, respectively.

The operation of high-frequency induction heating of the pin portions P1 to P4 and the flange portion F of the crankshaft 1 to a required quenching temperature by using the induction hardening apparatus 2 having such a configuration will be described as follows. It is.

First, the crankshaft 1 to be quenched is
Is mounted on a crankshaft rotation drive mechanism (not shown) and its rotation center axis X is held in a horizontal direction.
Is moved down from a predetermined standby position by a lifting mechanism (not shown), and the four heating coils 3a to 3d
Are mounted on the four pin portions P1 to P4 with a slight gap therebetween. Next, the crankshaft 1 is rotationally driven in the direction of the arrow α (see FIG. 6) about the rotation center axis X by a crankshaft rotation drive mechanism (not shown), and a high-frequency power from a high-frequency power supply (power matching panel) not shown. The power is supplied to the power supply lead conductor 8 and the disk transformers 4a to 4a.
4d are sequentially supplied to the heating coils 3a to 3d. Along with this, the rotation of the pins P1 to P4 (the rotation center of the crankshaft 1) while the heating coils 3a to 3d are mounted on the pins P1 to P4 by the function of the link-type following mechanism 6 (Revolution operation around the axis X), and during this follow-up movement, the surfaces of the pins P1 to P4 are induction-heated to a required quenching temperature by the heating coils 3a to 3d.

Thereafter, the supply of high-frequency power to the heating coils 3a to 3d is cut off while the crankshaft 1
When the quenching coolant is heated from the quenching coolant spray jacket (not shown) under the state where the rotation of
1 to P4, and the surfaces of the pins P1 to P4 are hardened. Then, while the rotational drive of the crankshaft 1 is stopped, the assembly 7 is moved upward by a lifting mechanism (not shown), and the heating coils 3a to 3d are connected to the pin portions P1 to P3.
4, the assembly 7 is locked at a predetermined standby position.

After the surface quenching of the pin portions P1 to P4, a cylinder (not shown) is actuated and the moving body 10 is moved linearly, so that the heating coil 9 is moved toward the flange portion F of the crankshaft 1 by an arrow β. It is moved in the direction (see FIG. 5) and is arranged at a position facing the outer peripheral surface of the flange portion F. Then
The crankshaft 1 is driven to rotate again, and high-frequency power is supplied to the heating coil 9, whereby the outer peripheral surface of the flange portion F is induction-heated to a required quenching temperature. Thereafter, the supply of high-frequency power to the heating coil 9 is cut off, and the outer periphery of the flange portion F in a heated state from a quenching coolant spray jacket (not shown) under a state in which the rotational drive of the crankshaft 1 is maintained. The quenching coolant is sprayed onto the surface, and the surface of the flange portion F is quenched. Thereafter, the rotational drive of the crankshaft 1 is stopped, and the heating coil 9 is separated from the flange portion F as the moving body 10 is operated by a cylinder (not shown), and returns to a predetermined standby position. Be moved.

Thus, at the first quenching station shown in FIG.
After the surface quenching of P4 and the flange portion F is performed, the crankshaft 1 is transferred to a subsequent second quenching station (not shown) by a transfer / conveyance device (not shown). The quenching process is performed on the journal portions J1 to J5 of the crankshaft 1.

[0015]

However, the conventional induction hardening method and apparatus for a crankshaft as described above have the following problems. That is, a plurality of pin portions of the crankshaft (in the case of the four-cylinder engine crankshaft 1, four pin portions P1 to P4) are simultaneously surface-hardened, and thereafter, a flange portion (for example, a flange of the crankshaft 1) is formed. Since the part F) is quenched, there is a problem that the time required for quenching one crankshaft becomes long and the efficiency of the quenching processing is low.

The present invention has been made in order to solve such a problem, and an object of the present invention is to perform quenching of a crankshaft in a short time, thereby improving the efficiency of quenching of the crankshaft. An object of the present invention is to provide a method and an apparatus for induction hardening of a crankshaft which can be improved.

[0017]

In order to achieve the above object, a method of induction hardening of a crankshaft according to the present invention comprises the steps of: induction heating a pin portion of a crankshaft; During the quenching cooling step of performing quenching cooling by injecting into the quenching, the quenching process of the flange portion at one end of the crankshaft or the shaft portion at the other end of the crankshaft is performed. ing. Further, in the induction hardening device for a crankshaft according to the present invention, (a) the pin portion of the crankshaft, which is to be quenched, is mounted on the pin portion of the crankshaft as the object to be hardened, While following the rotation,
A first high-frequency induction heating coil for high-frequency induction heating of the surface of the pin portion; and (b) a high-frequency induction heating for high-frequency induction heating of a flange portion on one end side of the crankshaft or a shaft portion on the other end side of the crankshaft. (C) a first quenching coolant injection mechanism for injecting a quench coolant onto the pins heated by high-frequency induction by the first high-frequency induction heating coil; A second quenching coolant injection mechanism for injecting a quench coolant onto the flange portion or the shaft portion, which has been subjected to high-frequency induction heating by the second high-frequency induction heating coil, and (e) the first high-frequency induction. After the high frequency induction heating of the pin portion with a heating coil, the first
When the quenching coolant is injected from the quenching coolant spray mechanism to quench and cool the pin portion, the quenching coolant is prevented from splashing on the flange portion or the shaft portion. And a mechanism, respectively, at the time of quenching and cooling of the pin portion,
The quenching liquid for quenching and cooling the pin portion is prevented from splashing on the shaft portion by the quenching coolant scattering prevention mechanism, and the quenching process of the flange portion or the shaft portion is performed. ing. In the induction hardening apparatus for a crankshaft according to the present invention, the quenching coolant scattering prevention mechanism may be configured to harden as the first high-frequency induction heating coil is mounted on the pin portion. A quenching cooling liquid scattering prevention cover inserted between the flange portion or the shaft portion to be provided and the pin portion closest to the flange portion or the shaft portion, and the flange portion or the shaft portion is simultaneously quenched and cooled in the pin portion. During the quenching process, the flange portion or the shaft portion and the pin portion closest to the flange portion or the shaft portion are partitioned by a quenching coolant scattering prevention cover. Further, in the induction heating apparatus for a crankshaft according to the present invention, the recess for the journal portion of the crankshaft to enter into the cover for preventing the quenching coolant from splashing, and the positioning tip whose tip slightly projects from the recess. During rotation of the crankshaft about the rotation center axis, the tip of the tip is journaled under the condition that the journal enters the recess of the quenching coolant scattering prevention cover. The quenching coolant scattering prevention cover is configured to maintain a fixed position by being in contact with the peripheral surface of the portion.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 6 are denoted by the same reference numerals, and redundant description will be omitted.

FIGS. 1 to 3 show an induction quenching apparatus 20 used for quenching pins P1 to P4 and a flange F of a crankshaft 1 for a four-cylinder engine. The induction hardening device 20 hardens the flange portion F while cooling the pin portions P1 to P4.

The induction hardening apparatus 20 according to the present embodiment comprises:
As shown in FIGS. 1 and 2, a quenching coolant scattering prevention mechanism 21 is additionally provided in addition to various components provided in the conventional apparatus. The quenching coolant scattering prevention mechanism 21 includes a quenching coolant scattering prevention cover 22 and a swing guide 23 having one end 23a welded to the quenching cooling solution scattering prevention cover 22. ing.

The above-described quenching coolant scattering prevention cover 22
As shown in FIGS. 2 and 3, a flat cover body 22a having a U-shaped recess 24 corresponding to the journal portion J1 on the flange portion F side of the crankshaft 1 and a projecting portion protruding from the cover body 22a. Support piece 2 attached to
2b and a hinge piece 22c fixed to the tip of the support piece 22b. And hinge piece 22c
Is rotatably attached to a hinge shaft 26 provided on a fixed base 25, so that the quenching coolant scattering prevention cover 22 is rotatable about the hinge shaft 26.
5 is assembled. Further, a ceramic chip (positioning chip) 27 whose tip end slightly projects into the U-shaped concave portion 24 is fixedly arranged on the cover main body 22a.

On the other hand, the above-mentioned swing guide 23 is made of a band-shaped member formed into a curved shape, and the other end side portion 23b
Is arranged so as to be guided and moved while sliding along a roller bearing 28 rotatably mounted on the leftmost disk transformer 4a in FIG. In addition,
The roller bearing 28 is attached only to the disk transformer 4a, and the roller bearings 28 are not attached to the other disk transformers 4b to 4d. Thus, as the assembly 7 is moved down from the predetermined standby position to place the heating coils 3a to 3d on the pins P1 to P4 of the crankshaft 1, the state shown in FIG. The state shown in FIG. That is, as the swinging guide 23 slides on the roller bearing 28 along with the downward movement of the assembly 7, an arc direction indicated by an arrow γ in FIG. 3 (the other end 23b of the swinging guide 23 is 28 (in a direction away from 28). In response, the quenching coolant scattering prevention cover 22 is rotated about the hinge shaft 26 in the direction of arrow β in FIG. 3, and the journal J1 of the crankshaft 1 is inserted into the U-shaped recess 24 of the cover main body 22a. It is configured to be inserted and arranged.

In the state shown in FIG. 3, the tip of the ceramic chip 27 slightly projecting from the U-shaped recess 24 of the cover body 22a is in contact with the cover 22 for preventing the quenching coolant from scattering. The journal portion J1 is inserted and accommodated in the U-shaped concave portion 24 in a state where there is a slight space between the journal portion J1 and the contact therebetween.

In the induction hardening device 20 of the present embodiment, although not shown, a first quenching coolant injection mechanism is provided at a lower position corresponding to the pin portions P1 to P4 of the crankshaft 1. The quenching coolant injection jacket constituting the second quenching coolant injection mechanism is arranged at a lower position corresponding to the flange portion F of the crankshaft 1. I have.

Next, the induction hardening apparatus 2 having the above-described structure is used.
The operation when the induction hardening method of the present invention is carried out by using No. 0 to harden the pin portions P1 to P4 and the flange portion F of the crankshaft 1 will be described below.

First, when the crankshaft 1 is set to a crankshaft rotation driving mechanism (not shown), the assembly 7 is moved down by a lifting mechanism (not shown), and the heating coils 3a to 3d are connected to the four pins of the crankshaft 1. It is placed on each of the parts P1 to P4. At this time, the heating coils 3a and 3d are mounted on the pins P1 and P4 at the top dead center, and the heating coils 3b and 3c are mounted on the pins P2 and P3 at the bottom dead center. Is placed. on the other hand,
When the heating coils 3a to 3d descend, the disk transformer 4a also moves downward, so that the roller bearing 28 attached to the disk transformer 4a also moves downward. Accordingly, the swing guide 23 is slid along the roller bearing 28 in the direction of arrow γ in FIG. 3, and the cover 22 for preventing the quenching coolant from splashing is supported by the hinge shaft 26 as a fulcrum and the arrow δ in FIG. Pivoted in the direction.

Then, the quenching cooling liquid scattering prevention cover 22
The journal portion J1 of the crankshaft 1 is inserted and arranged in the U-shaped concave portion 24, and the cover main body 22a of the quenching coolant scattering prevention cover 22 is arranged between the flange portion F of the crankshaft 1 and the journal portion J1. You. In this case, with the tip of the ceramic chip 27 attached to the cover main body 22a abutting on the uppermost portion of the journal J1, the cover 22 for preventing quenching cooling liquid from scattering is connected to the journal J1 via the ceramic chip 27. The cover body 22a of the quenching coolant scattering prevention cover 22 is placed as a partition plate or a shielding plate between the flange portion F of the crankshaft 1 and the journal portion J1.

Thereafter, the crankshaft 1 is rotationally driven in the direction of the arrow α in FIG. 3 by a crankshaft rotary drive mechanism (not shown), and the respective heating coils 3a to 3d are driven by the link type follower mechanism 6 to the respective pin portions P1 to P4. The high-frequency induction heating of the pin portions P1 to P4 is started under the state where the pins are moved. Even if the crankshaft 1 is driven to rotate about the rotation center axis X, the rotation center of the journal J1 on which the ceramic chip 27 of the quenching coolant scattering prevention cover 22 is placed is the rotation center axis X. Therefore, the quenching coolant scattering prevention cover 22 and the cover main body 22a are arranged between the flange portion F and the journal portion J1 in a stationary state without swinging. When the surfaces of the pin portions P1 to P4 reach a required quenching temperature by high-frequency induction heating for a predetermined time, a quenching cooling liquid spray jacket (not shown) disposed below each of the heating coils 3a to 3d. The cooling quench liquid is jetted from the (first quench quench liquid jetting mechanism) to the surfaces of the heated pin portions 3a to 3d. Thereby, the surfaces of the pin portions 3a to 3d are rapidly cooled, and a quenched and hardened layer is formed on those surfaces.

On the other hand, simultaneously with the start of the above-described quenching and cooling process for the pin portions P1 to P4, the moving body 10 is driven by a cylinder (not shown), and a flange portion integrated with the moving body 10 for heating the flange portion. The heating coil 9 is horizontally moved in the arrow β direction in FIG. 1 toward the flange portion F of the crankshaft. Next, when the heating coil 9 is arranged corresponding to a position surrounding the flange portion F, high-frequency induction heating of the flange portion F is started. Thus, in the present embodiment, the high-frequency induction heating step of the flange portion F is simultaneously performed during the quenching and cooling step of the pin portions P1 to P4.
When the surfaces of the pin portions P1 to P4 reach a required quenching temperature by high-frequency induction heating for a predetermined time, a quenching coolant for cooling a flange portion (not shown) attached to the lower portion of the flange portion F is provided. A cooling quench liquid is sprayed from a spray jacket (second quenching coolant spray mechanism) to the surface of the flange portion F in a heated state, the surface of the flange portion F is rapidly cooled, and a quench hardened layer is formed on those surfaces. It is formed.

At this time, the quenching cooling is performed so as to partition between the flange portion F and the pin portion P1 with the quenching coolant scattering prevention cover 22 placed on the journal J1 as described above. Since the liquid scattering prevention cover 22 is interposed,
The quenching coolant sprayed from the quenching coolant spray jacket for cooling the pin portion and the quenching coolant splashed from the pin portions P1 to P4, the counterweights K1 to K8, etc., cause the flange portion F during high frequency induction heating. Is prevented.

When the quenching and cooling step of the flange portion F is completed, the quenched crankshaft 1 is removed from a crankshaft rotation drive mechanism (not shown) and is subsequently moved by a transfer / conveyance device (not shown). To a journal quenching station (not shown).

According to the crankshaft quenching method and apparatus according to this embodiment,
The surface quenching of the four pin portions P1 to P4 between each of the journal portions J1 to J5 is simultaneously performed, and in addition to the purpose of obtaining a required hardened hardened layer, the entire distortion and bending of the crankshaft 1 are performed. Since the quenching process of the flange portion F, which is also performed for the purpose of reducing the amount of heat, is performed during the quenching and cooling process of the pin portions P1 to P4, the quenching process time of the crankshaft 1 can be greatly reduced. . In particular, the pin portion 3a
If both the quenching process of the flange portion F and the flange portion F must be completed, the quenching process of the flange portion F is started after the quenching process of the pin portions 3a to 3d is completed as in the related art. By simultaneously performing the quenching and cooling process after the high-frequency induction heating of the pin portions 3a to 3d and the high-frequency induction heating process and the quenching and cooling process of the flange portion F at the same time,
It is possible to improve the quenching processing efficiency per one crankshaft 1 (reduce the processing time).

When the quenching cooling liquid for cooling the pin portion is applied to the flange portion F at the same time when the quenching and cooling process for the pin portions 3a to 3d and the high-frequency induction heating process for the flange portion F are performed simultaneously, In this embodiment, the cover 7 for preventing the quenching coolant from scattering is provided in conjunction with the ascending and descending movement of the assembly 7 and thus the high-frequency induction heating coils 3a to 3d. It is possible to prevent the quenching coolant injected into the 3d from splashing on the flange portion F during high-frequency induction heating. In addition, according to the configuration of the present embodiment, the cover 22 for preventing the quenching coolant from scattering is placed on the journal J1 coaxial with the rotation center axis X of the crankshaft 1 and used. Even when the crankshaft 1 is rotationally driven, the quenching coolant scattering prevention cover 22 can function as a partition plate or a shielding plate for the quenching coolant in a stationary state.

Although the embodiment of the present invention has been described above, the present invention is not limited to this embodiment.
Various modifications and changes are possible based on the technical concept of the present invention. For example, in the above-described embodiment, a case has been described in which the flange portion F on one end side of the crankshaft 1 is quenched together with the pin portions 3a to 3d of the crankshaft 1, but together with the pin portions 3a to 3d of the crankshaft 1. The present invention can be applied to a case where a shaft portion (spline portion or seal portion) S on the other end side of the crankshaft 1 is subjected to quenching. In addition, it goes without saying that the present invention is not limited to the crankshaft 1 for a four-cylinder engine, but can be applied to quenching processing of various other types (for example, crankshafts for three- and six-cylinder engines). No.

[0035]

According to the first aspect of the present invention, a quenching cooling step of quenching and cooling by injecting a quenching coolant to the pin portion after high-frequency induction heating of the pin portion of the crankshaft is performed. Since the quenching process of the flange portion at one end of the crankshaft or the shaft portion at the other end of the crankshaft is performed, the quenching process time per one crankshaft is reduced. can do.
That is, according to the induction hardening method of the crankshaft according to the present invention, the quenching process of the flange portion at one end or the shaft portion at the other end is simultaneously performed while quenching and cooling the pin portion of the crankshaft. To do it,
The quenching process of the crankshaft can be performed in a short time, and the quenching process efficiency of the crankshaft can be improved.

According to a second aspect of the present invention, when the pin portion is subjected to high-frequency induction heating, a quenching coolant is injected to quench and cool the pin portion, the quenching coolant is supplied to the flange of the crankshaft. A quenching coolant scattering prevention mechanism is provided to prevent the quenching coolant from splashing on the shaft or the shaft. The quenching process of the flange portion or shaft portion is performed while preventing the quenching liquid scattering prevention mechanism, so the quenching process of the flange portion or shaft portion is performed in parallel with the quenching and cooling process of the pin portion. The quenching process can be performed simultaneously on the pin portion and the flange portion, or the pin portion and the shaft portion, so that the quenching time can be significantly reduced, that is, the cycle time can be reduced. Therefore, according to the present invention, it is possible to provide a practical induction hardening device with extremely high quenching efficiency.

According to a third aspect of the present invention, there is provided a quenching coolant provided in a quenching coolant scattering prevention mechanism when quenching a flange portion or a shaft portion simultaneously with quenching and cooling of a pin portion. Since the shatterproof cover is used to partition between the flange or shaft and the pin closest to it,
While having the above-described functions and effects, the apparatus can be configured with a simple configuration in which a cover for preventing scattering of the quenching coolant is added to the conventional induction hardening apparatus.

According to a fourth aspect of the present invention, a cover for preventing the quenching coolant from scattering is provided with a concave portion into which the journal of the crankshaft enters, and a tip having a tip slightly projecting from the concave portion. At the time of rotation about the rotation center axis of the crankshaft, the tip of the tip abuts on the peripheral surface of the journal under the condition that the journal enters the recess of the quenching coolant scattering prevention cover. Since the quenching coolant scattering prevention cover is configured to maintain a fixed position, the quenching cooling solution scattering prevention cover fluctuates even when the crankshaft is driven to rotate and, consequently, also when the pin portion rotates. And the cover is always disposed at a predetermined partition position between the pin portion and the flange portion or the shaft portion. It is possible, it is possible to make quenching coolant flange portion or the shaft portion is not applied.

[Brief description of the drawings]

FIG. 1 is a front view showing an induction hardening device for a four-cylinder engine crankshaft according to an embodiment of the present invention.

FIG. 2 is an enlarged side view showing a main part of the induction hardening apparatus of FIG. 1, and is a side view showing a state when a heating coil is raised.

FIG. 3 is an enlarged side view showing a main part of the induction hardening apparatus of FIG. 1 and is a side view showing a state when a heating coil is lowered.

FIG. 4 is a front view of a crankshaft as a member to be quenched.

FIG. 5 is a front view showing a conventional induction hardening apparatus for implementing the conventional crankshaft induction hardening method.

FIG. 6 is an enlarged side view showing a main part of the induction hardening apparatus of FIG. 5, and is a side view showing a state when a heating coil is lowered.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 4-cylinder engine crankshaft 3a-3d High frequency induction heating coil 4a-4d Disk transformer 6 Link type follow-up mechanism 7 Assembly 8 Power supply lead conductor 20 High frequency quenching device 21 Quenching coolant scattering prevention mechanism 22 Quenching coolant Shatterproof cover 22a Cover body 23 Swing guide 24 U-shaped recess 26 Hinge shaft 27 Ceramic chip (chip for positioning) 28 Roller bearing F Flange J1 to J5 Journal K1 to K8 Counterweight P1 to P4 Pin S Part (spline part or seal part)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 6/44 H05B 6/44

Claims (4)

[Claims] 1. A quenching cooling step of injecting a quenching coolant to the pin portion after high-frequency induction heating of a pin portion of the crankshaft to perform quenching cooling, the quenching cooling process being performed at one end of the crankshaft. A high-frequency quenching method for a crankshaft, wherein a quenching process is performed on a flange portion or a shaft portion on the other end side of the crankshaft. 2. A method according to claim 1, wherein the pin is mounted on a pin of a crankshaft as a material to be quenched while following the rotation of the pin in accordance with the rotation of the crankshaft. A first high-frequency induction heating coil for high-frequency induction heating of the surface of the portion, and (b) a second high-frequency induction heating for high-frequency induction heating of a flange portion at one end of the crankshaft or a shaft portion at the other end of the crankshaft. A high-frequency induction heating coil, (c) a first quenching cooling liquid injection mechanism for injecting a quench cooling liquid to the pin portion that has been subjected to high-frequency induction heating by the first high-frequency induction heating coil, and (d) A second quench coolant injection mechanism for injecting a quench coolant into the flange portion or the shaft portion, which has been induction-heated by a second high-frequency induction heating coil, and (e) the first high-frequency induction heating coil At the pin When the quenching coolant is injected from the first quenching coolant injection mechanism after the high frequency induction heating to quench and cool the pin portion, the quenching coolant is applied to the flange portion or the shaft portion. And a quenching coolant scattering prevention mechanism for preventing quenching of the pin portion, wherein the quenching coolant for quenching and cooling the pin portion is applied to the shaft portion during quenching and cooling of the pin portion. An induction hardening device for a crankshaft, wherein a quenching process is performed on the flange portion or the shaft portion while preventing the coolant from splashing. 3. The quenching coolant scattering prevention mechanism includes: a first HF induction heating coil mounted on the flange portion; A quenching cooling liquid scattering prevention cover inserted between the pin portion and the cover portion, the quenching process of the flange portion or the shaft portion simultaneously with the quenching and cooling of the pin portion; The induction hardening device for a crankshaft according to claim 2, wherein a portion between the shaft portion or the shaft portion and the pin portion closest to the shaft portion is partitioned by a quenching coolant scattering prevention cover. 4. A recess into which the journal of the crankshaft enters the quenching coolant scattering prevention cover;
A positioning tip whose tip slightly projects from the recess is provided, and the journal portion is located in the recess of the quenching coolant scattering prevention cover when the crankshaft rotates about the rotation center axis. The quenching coolant scattering prevention cover is configured to maintain a fixed position by abutting a tip portion of the tip against a peripheral surface of the journal portion in a state where the tip is intruded. 3. The induction hardening device for a crankshaft according to 3.