JP2779763B2 - Semi-open induction hardened coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-open induction hardening coil, and more particularly to a semi-open induction hardening coil for quenching an annular hardened surface of an object to be hardened such as a pin or a journal of a crankshaft.

[0002]

2. Description of the Related Art A conventional technique will be described below with reference to the drawings, taking as an example the case of hardening a pin of a crankshaft. 4 is a perspective view showing the appearance of a conventional semi-open induction hardening coil, FIG. 5 is a cross-sectional view taken along the line BB of FIG. 4, and FIG. 6 is a high-frequency wave explaining a state where the induction hardening coil is mounted on a part to be hardened. It is a principal part front view of a quenching apparatus.

[0003] A conventional semi-open induction hardening coil (hereinafter referred to as "quenching coil") 50 has a heating coil 5 as shown in FIG.
1, 52, 53, 54, connection coils 55, 56, 57, feeding coils 58, 59 and a core 60. All of these coils are made of hollow good conductive metal.

The heating coils 51, 52, 53, 54 have substantially the same shape and are formed in a substantially quarter-arc shape corresponding to the shape of the surface 11 of the pin 10. Heating coil 51
Has a leading end at one end of the feeding coil 58 and a rear end at the connecting coil 5.
5, and the tip of the heating coil 52 is connected to the rear end of the connection coil 55, respectively. The rear end of the heating coil 52 and the front end of the heating coil 53 are connected to a connection coil 56. The heating coils 53 and 54 are connected to the connection coil 57 and the power supply coil 59 as described above. The shape of the quenched coil 50 in plan view is S-shaped.
The power supply coils 58 and 59 are connected to the power supply 4 via the lead body 41.
0, and the hollow portion of the coil is
1. The discharge pipe 62 is connected.

As shown in FIG. 5, the surfaces of the heating coils 51, 52, 53, 54 and the connection coils 55, 56 are covered with a core 60 made of laminated steel sheet or ferrite except for 60A. The core 60 includes heating coils 51, 5
The magnetic flux generated by the current flowing through the connection coils 53, 54 and the connection coils 55, 56 is focused in the core 60, and the magnetic flux emitted from the core 60 is concentrated on the surface 11 of the pin.

The quenching coil 50 is mounted on an induction hardening device as shown in FIG. In the figure, 64 is a coil side plate, 6
Reference numeral 8 denotes a jacket for injecting a cooling liquid for quenching to the surface 11 of the pin 10.

In order to prevent the quenched coil 50 from coming into contact with the pin 10 during quenching of the pin 10 and to keep the quenched coil 50 at a constant gap distance from the pin 10,
A spacer 65 is provided at a central portion of the coil 0, and side spacers 66 are provided on both sides of the quenched coil 50. The spacers 65 and 66 are both bolted by the bolt 67 to the coil side plate 6.
4 is fixed.

[0008] The coil side plate 64 is responsible for load fluctuations of the quenching coil 50 and a transformer (not shown) for supplying power to the quenching coil 50 due to crank motion.
It is composed of an aluminum plate, a brass plate, a glass laminate plate or the like. Each of the spacers, particularly the spacer 65 at the center, uses a chip material made of carbide.

After the quenching coil 50 is disposed so as to approach and face the surface 11 of the pin 10, the crankshaft is rotated. The coolant of the quenching coil 50 is supplied to the supply pipe 61, passes through the hollow portion of the quenching coil 50, cools the coil, and is discharged from the discharge pipe 62.

The high-frequency current is supplied from a power source 40 to a feeding coil 58.
The heat flows through the heating coil 51, the connection coil 55, the heating coil 52, the connection coil 56, the heating coil 53, the connection coil 57, the heating coil 54, and the power supply coil 59, and the surface 1 of the pin 10
1 is heated by the induced current of each coil.
The cooling liquid is supplied from a power supply pipe 61, cools the coils, and is discharged from a discharge pipe 62.

[0011]

However, in the quenched coil 50, the spacer 65 located at the central portion of the quenched coil 50 is induced by the high-frequency current flowing through the connecting coil 56 at the central portion forming the S-shape. Is heated and eventually reaches a glowing state. Therefore, the temperature of the coil side plate 63 also becomes high.

Since the side spacer 66 is not surrounded by the quenching coil 50, it is not heated unlike the spacer 65, but in any case, it is dangerous that the coil holding member of the induction hardening device becomes red hot. There was a demand for improvement in safety measures.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a quenched coil that is safe without a heating of a coil holding member and has a long life.

[0014]

According to the present invention, a semi-open high circumference is provided.
The wave hardening coil is located above the annular hardened surface of the hardened object.
A substantially semi-circular or semi-circular disposed close to the surface to be quenched
Hollow first part having an arc portion formed by a small circle
The heating coil has substantially the same shape as the first heating coil.
And faces the first heating coil at a predetermined distance.
And a second heating coil disposed close to the surface to be quenched.
And the approximate center of the arc of the first and second heating coils.
A pair of hollow power supply coils having one end connected thereto;
And a pair of hollows connecting both ends of the second heating coil
Connection coil and the other end of the feeding coil
Connected to the cooling supply pipe and the first and second heating coils
A coolant discharge pipe, and the first and second heating coils and connection
So as to cover the surface of the coil not facing the quenched surface
A first heating coil and a second heating coil.
Spacer that keeps the gap distance between the tool and the hardened surface constant
The center of the arc of the first and second heating coils present
The vicinity of the minute is arranged to be narrower than the predetermined distance interval.
In addition, a high-frequency voltage is applied between the other ends of the power supply coils.
It has become so.

[0015] The coolant discharge pipe is provided at opposite ends of the heating coil, and hollow portions of the first and second heating coils and the connection coil are provided in accordance with the length of the coolant flow path. In this case, the cooling liquid is made to flow evenly in each of the coils by forming grooves having different widths.

[0016]

[Function] The high frequency current is divided into two parts to the left and right from the feeding coil.
Powered. The divided current is applied to one feeding coil,
1 heating coil, one connecting coil, 2nd heating coil
The route through the left half of the thermal coil and the other feeding coil,
The right half of the first heating coil, the other connecting coil, the second
It flows into a route that passes through the right half of the heating coil.
Near the center of the arc, the high-frequency current flows
The spacer located in this part is induced current
Is negated.

The coolant for the quenching coil is divided into two and supplied from a supply pipe. One of the two is cooled from the discharge pipe after passing through the left half of the first heating coil of the feeding coil, and the other is discharged from the discharge pipe through the right half of the feeding coil, the first heating coil and the connection coil. Is discharged.
One of the two halves is discharged from the discharge pipe via the power supply coil and the left half of the second heating coil to the discharge pipe via the connection coil, and the other is discharged from the discharge pipe via the power supply coil and the left half of the second heating coil. You.

Further, since the coolant flowing from the supply pipe changes the groove width based on the length of the passage, it flows uniformly in each coil and is discharged from the discharge pipe. Therefore, the first and second heating coils are uniformly cooled.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A semi-open induction hardening coil for hardening the surface of a pin of a crankshaft will be described as an example.

FIG. 1 is a schematic external perspective view for explaining one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG.
FIG. 4 is an explanatory diagram of a current and a coolant flow path. The same components as those described in the related art will be described with the same reference numerals.
The semi-open induction hardening coil (hereinafter referred to as “hardening coil”) 20 of this embodiment is disposed close to the surface 11 of the pin 10 of the crankshaft and is used to harden this surface 11.

As shown in FIGS. 1 and 3, the quenching coil 20 includes a first heating coil 21, a second heating coil 22, feeding coils 23 and 24, connecting coils 25 and 26, and a core 60. ing. All of these coils are made of hollow good conductive metal.

The first heating coil 21 has an arc portion 21a formed in a substantially semicircular or smaller circle than the semicircle so as to correspond to the shape of the surface 11 of the pin. However, an appropriate value is selected depending on the required depth of the hardened layer and the like, without being limited to the semicircle.

The second heating coil 22 has substantially the same shape as the first heating coil 21. The second heating coil 22 faces the first heating coil 21 at a predetermined distance D and faces the first surface of the pin.
1.

First heating coil 21 and second heating coil
Reference numeral 22 denotes a distance in the vicinity of substantially the center of the arc portions 21a and 22a.
Fold so that the separation distance is smaller than the predetermined distance distance D.
The power supply coils 23 and 24
One end is electrically connected.

Also, the first and second heating coils 21 and 22
Are connected by a pair of connecting tiles 25 and 26.
It is electrically connected. In addition, the feeding coils 23 and 24
Is connected to a high-frequency power supply 40 by a lead body 41 (see FIG. 6).
Are electrically connected via the power supply coils 23, 2
The hollow portions of No. 4 are respectively connected to the coolant supply pipes 61A and 61B.
It is connected. The first and second heating coils 21 and 2
The coolant discharge pipes 62 and 63 are located
Each is connected.

As shown in FIG. 2, the first and second heating coils 21 and 22 and the connection coils 25 and 26 are made of laminated steel sheets or ferrite-based steel sheets. , Except for a surface 60A facing the surface 11 with a core 601 having a substantially U-shaped cross section. In the figure, reference numeral 30 denotes a groove formed on the inner surface in the longitudinal direction of the coil. (The description of the groove 30 will be described later.)

The gap between the quenched coil 20 and the pin 10
In order to keep the distance constant, use a method according to FIG.
The sensor 65 is mounted near the power feeding coils 23 and 24
I have. That is, the spacer 65 is formed by the first and second spacers.
Of the arc portions 21a and 22a of the heating coils 21 and 22
It is provided near the portion. Also, the connection coil
Side spacers 66 are attached near 25 and 26
Have been. Further, it is heated by the quenching coil 20.
Coolant for quenching the surface 11 of the pin 10 to be quenched
A jacket 68 (not shown) for injecting air is provided according to FIG.
Is provided.

Next, the operation of this embodiment will be described. The quenching coil 20 is arranged so that the first and second heating coils 21 and 22 approach the pin surface 11 and face the pin 10, and the crankshaft rotates.

As shown by the black arrows in FIG. 3, the coolant of the quenching coil 20 is divided into two and supplied to the supply pipes 61A and 61B. One of them is the feeding coil 23, the first heating coil 21
After cooling these coils through the left half of the drawing,
2, and the other is discharged from the discharge pipe 63 via the power supply coil 23, the right half of the first heating coil 21 in the drawing, and the connection coil 26. The coolant supplied to the supply pipe 61B passes through the power supply coil 24, the left half of the second heating coil 22 in the drawing, the connection coil 25, and the discharge pipe 62 according to the above, and the other is supplied with the power supply coil 24 and the second heating coil. After passing through the right half of FIG.

As shown by the white arrows in FIG. 3, the high-frequency current is divided into two parts by the power supply coil 23 to the left and right, and flows through each half of the first and second heating coils 21 and 22 and one of the connection coils 25 and 26. , And returns to the power supply 40 via the feeding coil 24. The surface 11 of the pin 10 has the first and second heating coils 2
It is heated by the induction current induced by the high-frequency current flowing through the first and second 22 and the connection coils 25 and 26.

Accordingly, the impedance of the quenched coil 20 decreases with the inductance, so that a large current can flow and a large power can be obtained.

Further, the cooling liquid flow path is substantially halved as compared with the conventional hardening coil, so that the cooling effect can be enhanced.
Therefore, the temperature rise can be reduced as compared with the conventional quenched coil, so that the degree of deterioration thermal fatigue is reduced, and the occurrence of cracks caused by the decrease in mechanical strength due to the progress of deterioration is prevented. Can be. Therefore, the life of the quenched coil can be extended.

The central portion of the surface 11 is made up of the first and second
Narrower than the predetermined distance D between the heating coils 21 and 22
It's getting worse. Therefore, the distance between the feeding coils 23 and 24
The gap is narrowing. Then, the arc portions 21a, 22
In the vicinity of the center of a, the directions of the currents are opposite to each other.
Therefore, the spacer 65 is not heated by the induced current.
And not. The operation of the core 60 will be described in the related art.
The description is omitted here.

As described above, the core 60 is provided on the first and second heating coils 21 and 22 and the connection coils 25 and 26. However, in order to equalize the flow path of the coolant, the discharge pipes 62, 63 are provided at the central portions of the connection coils 25, 26.
Are connected, the installation location of the core 60 is changed to the connection coil 25,
26 cannot be located at the center of the pin 26, and it becomes difficult to uniformly heat the surface of the pin 10.

For this reason, as shown in FIGS.
2 and 63 are connected to the first and second heating coils 21 and 2.
2 connected to the opposite ends A and B, respectively,
The core 60 is provided so as to be located substantially at the center of the connection coils 25 and 26. That is, the ends A and B are hardened coils 2
It is symmetrical with respect to the center point C of 0.

When the discharge pipes 62 and 63 are connected as described above, the flow path of the cooling liquid becomes longer and shorter, and the cooling liquid does not flow evenly through each coil. Therefore, the size (cross-sectional area) of the first and second heating coils 21 and 22 and the connection coils 25 and 26 is changed, and the supply pipes 61A and 61B supply the discharge pipe 62,
The cooling liquid is made to flow evenly in each path leading to 63.

In this embodiment, the groove is formed by changing the width of the inner surface of the hollow portion of the coil in the lateral width direction. The above problem is solved by reducing the size.

[0038]

As described above, the quenching coil of the present invention
The annular surface formed on the surface of the object to be
A connection coil connects both ends of the first and second heating coils connected to each other.
Connection, two parallel circuits viewed from the feed coil
A road is formed.

Then, substantially the center of the first and second heating coils
Power supply to each coil by connecting the part to the power supply and coolant supply pipe
As well as a contact that is symmetrical about the center of the hardened coil.
Provide a coolant discharge pipe at the opposite end of the
A core is provided at the center of the file. further,
The distance interval near the center of the first and second heating coils is:
Arrange so that it is narrower than the specified distance interval of other parts
ing.

Therefore, the impedance of the quenched coil is small, and a large power can be obtained. Also, since the coolant passage is reduced by half compared to the conventional case, the cooling effect of the coil is enhanced, and the life of the quenched coil is prolonged.

Further , the first and second heating coils and the above-mentioned
Of the spacers that maintain a constant gap distance from the entrance surface,
Provided near the center of the arc of the first and second heating coils;
Are not heated by the induced current,
In addition, the safety of the quenching device is improved.

[0042]

[Brief description of the drawings]

FIG. 1 is a drawing according to the present invention, and is a schematic external perspective view of a quenched coil.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view illustrating a flow passage of a current cooling unit of the quenching coil.

FIG. 4 is a drawing related to the prior art, and is a schematic external perspective view of a quenched coil.

FIG. 5 is a view taken along line BB of FIG. 4;

FIG. 6 is a front view of a main part of the induction hardening apparatus for explaining a state in which a high-frequency coil is mounted on a portion to be hardened.

[Explanation of symbols]

 10 pin 20 semi-open induction hardening coil 21 first heating coil 22 second heating coil 23 power supply coil 24 power supply coil 25 connection coil 26 connection coil 40 power supply 60 core 61A, 61B supply pipe 62 discharge pipe 63 discharge pipe 64 coil Side plate 65 Spacer

Claims (2)

(57) [Claims] 1. An object to be quenched has an annular quench hardened surface at an upper position.
It is arranged close to the surface to be hardened and is approximately semicircular or
A hollow first member having an arc portion formed by a small circle
The heat coil has substantially the same shape as the first heating coil.
And faces the first heating coil at a predetermined distance.
A second heating coil disposed close to the surface to be quenched
And approximately one center of the arc portion of the first and second heating coils.
A pair of hollow feeding coils having ends connected thereto;
A pair of hollow shapes connecting both ends of the second heating coil
Connection coil and the other end of the feeding coil
A cooling supply pipe and a cooling supply pipe connected to the first and second heating coils;
A reject liquid discharge pipe, and the first and second heating coils and the connection coil.
So as to cover the surface of the il not facing the quenched surface.
And a first heating coil and a second heating coil.
Spacer that keeps the gap distance between the tool and the hardened surface constant
The center of the arc of the first and second heating coils present
The vicinity of the minute is arranged to be narrower than the predetermined distance interval.
In addition, a high-frequency voltage is applied between the other ends of the power supply coils.
A semi-open induction hardened coil characterized in that: 2. The cooling liquid discharge pipe is provided at opposite ends of the first and second heating coils, and a cooling liquid is provided in hollow portions of the first and second heating coils and the connection coil. 2. The semi-open induction hardened coil according to claim 1, wherein grooves having different widths are formed in accordance with the length of the flow path so that the coolant flows evenly in each of the coils.