JP3059167B1 - Oxidation-free induction heat treatment method and apparatus - Google Patents

Abstract

An atmosphere chamber can be completely sealed, and the atmosphere chamber can be uniformly replaced with an inert gas or a reducing gas in a short time. So that high-frequency heat treatment can be performed. SOLUTION: At the time of high-frequency induction heating, a work cooling liquid is stored in a liquid receiving tank 21 attached to a work holding jig 20, and atmosphere chambers 101 and 102 are filled with the work cooling liquid L stored in the liquid receiving tank 21. In addition to shielding from the atmosphere, an on-off valve 80 is installed at the work coolant discharge port 22 provided on the work holding jig 20, and the on-off valve 80
1, 102 is shielded from the atmosphere, and when cooled, the on-off valve 80
Is switched to the valve open state, the work holding jig 20
The work cooling liquid L stored in the work holding jig 20 is discharged to the outside of the work holding jig 20, and the atmosphere chamber 10 is placed in the work holding jig 20.
Form 2

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-oxidizing induction heat treatment method and apparatus, for example, a method and a method for non-oxidizing induction hardening of an inner surface, an outer surface or an end surface of a work having open ends. It is suitable for application to an apparatus.

[0002]

2. Description of the Related Art Conventionally, when an inner surface, an outer surface, or an end surface of a work whose both end surfaces have an open shape is non-oxidized and quenched,
A non-oxidizing induction hardening apparatus 200 as shown in FIG. 4 is used. This non-oxidation induction hardening device 200
As shown in FIG. 4, atmosphere holding chambers 101 and 102 for performing high-frequency induction heating and quenching and cooling, and a box-shaped (box-shaped body including a peripheral wall and a bottom wall) work for holding and holding a work W are provided. 20, a high-frequency induction heating coil 30, a heating coil mounting plate 40 to which the high-frequency induction heating coil 30 is mounted, a base 50, and a spray jacket 60 for cooling the outer periphery of the work.

[0003] Thus, the above-described non-oxidizing induction hardening apparatus 2
00, the inner surface of the workpiece W (for example, the ring gear 10
In performing the non-oxidation induction hardening of the gear portion 11) formed on the inner peripheral surface of the workpiece W, the inert gas or the reducing gas is introduced into the atmosphere chambers 101 and 102 through the gas introduction pipe 41 while the work W Is heated by the high-frequency induction heating coil 30 while being driven to rotate about its axis, and when the predetermined heating is completed, the work W is transferred downward by a predetermined distance, and the work W The non-oxidative quenching is performed by injecting a work coolant from the lower portion 61b of the circumferential cooling spray jacket 70 and the work outer circumferential cooling spray jacket 60 toward the heating surface of the work W to rapidly cool the work W.

[0004]

However, the conventional non-oxidizing induction hardening apparatus 200 as described above, and the conventional non-oxidizing induction hardening method for performing the non-oxidizing induction hardening using this apparatus 200. Then, there are the following problems.

That is, in order to move the work W up and down between the heating position and the cooling position, the work holding jig is formed in the cylindrical hollow portion S of the work outer periphery cooling spray jacket 60 constituting the lower region of the atmosphere chamber 101. The tool 20 must be configured to be able to move along its axial direction and to be able to inject the outer peripheral cooling liquid from the lower portion 61b of the outer peripheral cooling spraying jacket 60. Inner peripheral surface 6 of cooling spray jacket 60
It is necessary to provide a gap γ (see FIG. 4) between the workpiece holding jig 20 and the outer peripheral surface 20a of the work holding jig 20.

Further, the work holding jig 20 has a plurality of work cooling liquid discharge ports 22 for discharging the cooling liquid jetted from the work inner peripheral cooling jetting jacket 70. There is a problem that the airtightness of the atmosphere chamber 102 is deteriorated. Further, from the time when the heating is completed to the time when the work W is transferred from the heating position to the cooling position thereafter, the airtightness of the atmosphere chambers 101 and 102 is further deteriorated, so that the work surface is oxidized, resulting in good non-oxidation. There is a problem that induction hardening cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to completely seal an atmosphere chamber and to allow an inert gas or an inert gas in an atmosphere chamber in a short time. An object of the present invention is to provide a non-oxidizing high-frequency heat treatment method and apparatus that can be uniformly replaced with a reducing gas and thereby perform high-frequency heat treatment under a favorable oxygen-free state.

[0008]

According to the present invention, a work held by a vertically movable work holding jig is provided in an atmosphere chamber containing an inert gas or a reducing gas. In a non-oxidizing high-frequency heat treatment method in which a heated portion of the work is subjected to high-frequency induction heating and then a work coolant is sprayed onto a heated portion of the work to cool the work, the work is held during high-frequency induction heating. The work cooling liquid is stored in a liquid receiving tank attached to a jig, the atmosphere chamber is shielded from the atmosphere by the work cooling liquid stored in the liquid receiving tank, and a work provided on the work holding jig is provided. An on-off valve is installed at the cooling liquid discharge port, the atmosphere chamber is shielded from the atmosphere by the on-off valve, and at the time of cooling, the on-off valve is switched to an open state, so that the work holding jig is placed in the work holding jig. The fit was workpiece coolant is discharged to the outside of the workpiece holding jig, and to form an atmospheric chamber to the work holding fixture within. Further, in the present invention, in the step of high-frequency induction heating of the heated portion of the work, an oxygen-containing air is exhausted from the atmosphere chamber to the atmosphere, and then an inert gas or a reducing gas is fed into the atmosphere chamber, or By sending an inert gas or a reducing gas into the atmosphere chamber while exhausting the air from the atmosphere chamber into the atmosphere, the atmosphere in the atmosphere chamber is replaced with the inert gas or the reducing gas. Further, in the present invention, in the step of high-frequency induction heating the heated portion of the work, by using an oxygen concentration measurement suction pipe disposed in the atmosphere chamber, by measuring the oxygen concentration in the atmosphere chamber, The atmosphere in the atmosphere chamber is confirmed to be lower than a predetermined oxygen concentration. Further, in the present invention, the workpiece is transferred to the cooling position while maintaining the oxygen-free state after the high-frequency induction heating. Further, in the present invention, the inner surface, the outer surface, or the end surface of the work whose both end surfaces have an open shape is subjected to high-frequency heat treatment.

According to the present invention, a work held by a vertically movable work holding jig is arranged in an atmosphere chamber containing an inert gas or a reducing gas, and a heated portion of the work is induced by high-frequency induction. (A) A box-shaped jig for holding the work at a predetermined position in the non-oxidizing high-frequency heat treatment apparatus in which a work cooling liquid is sprayed onto a heated portion of the work after heating to cool the work. A work holding jig having a work coolant discharge port for discharging the work coolant stored in the jig to the outside of the jig, and an open / close valve for opening and closing the work coolant discharge port; B) a high-frequency induction heating coil arranged to correspond to the work and high-frequency induction-heats a heated portion of the work; and (C) a work coolant spray jacket for spraying a work coolant to the work. (D) a liquid receiving tank arranged to surround an outer periphery of the work holding jig for storing a work cooling liquid injected from the work cooling liquid spray jacket to the work; An air suction pipe for discharging the air outside the atmosphere chamber;
And (F) a gas introduction pipe for introducing an inert gas or a reducing gas into the work, and the work cooling liquid spray jacket extends in the work cooling liquid stored in the liquid receiving tank. By inserting a ring-shaped part, the atmosphere in the atmosphere chamber and the atmosphere are shut off. Further, in the present invention, a work held by a vertically movable work holding jig is arranged in an atmosphere chamber in which an inert gas or a reducing gas is used as an atmosphere, and the heated portion of the work is subjected to high-frequency induction heating. And (A) a box-shaped jig for holding the work at a predetermined position, wherein the work cooling liquid is sprayed onto a heated portion of the work to cool the work. A work coolant discharge port for discharging the work coolant stored in the fixture to the outside of the jig, an open / close valve for opening and closing the work coolant discharge port, and a liquid receiving tank for storing the work coolant. (B) a high-frequency induction heating coil arranged corresponding to the work and for high-frequency induction heating of a heated portion of the work, and (C) oxygen-containing air. (D) an inert gas or reducing property for the work, the air suction pipe including an air suction pipe for discharging to the outside of the atmosphere chamber, and an air suction means connected to the air suction pipe to apply suction force; It comprises a gas introduction pipe for introducing gas, a gas flow rate adjustment valve for adjusting the flow rate of the gas flowing through the gas introduction pipe, and an electromagnetic valve for opening or closing the gas introduction pipe to supply or shut off the gas. A gas introduction mechanism, and (E) an oxygen concentration measurement mechanism including an oxygen concentration measurement gas suction pipe for measuring the oxygen concentration in the atmosphere chamber, and oxygen concentration measurement means connected to the oxygen concentration measurement gas suction pipe. , (F)
A work coolant injection jacket having a ring-shaped portion inserted into the work coolant in the liquid receiving tank to shut off the atmosphere from the atmosphere in the atmosphere chamber, and introducing the work coolant into the work coolant injection jacket. A work coolant introducing pipe, a work coolant flow regulating valve for adjusting a flow rate of the work coolant flowing through the work coolant introducing pipe, and a work coolant supplying or shutting by opening and closing the work coolant introducing pipe. A work cooling mechanism composed of a solenoid valve;
Are provided.

According to a preferred embodiment of the present invention, there is provided a non-oxidation induction hardening method for quenching the inner peripheral surface of a work having both open end faces. Shielding the work coolant outlet,
(B) storing a work coolant at a predetermined pressure and flow rate sprayed onto the work outer peripheral surface from the work outer peripheral cooling spray jacket in a liquid receiving tank attached outside the work holding jig; Exhausting oxygen (air) in the atmosphere chamber to the outside through an air suction pipe attached to the inner peripheral cooling injection jacket; and (d) high-frequency induction heating of an inert gas or a reducing gas at a predetermined pressure and flow rate Injecting toward the inner peripheral surface of the work at the periphery of the coil, and injecting from the heating coil mounting plate toward the upper surface of the work, the high-frequency induction heating coil and the work are heated at the heated portion of the inner peripheral surface to the work. Making the inner peripheral surface of the workpiece oxygen-free by flowing the fluid into the passage formed between the workpiece and (e) through an oxygen concentration measurement suction pipe disposed above the workpiece. A step of confirming that the atmosphere in the atmosphere chamber is equal to or lower than a predetermined oxygen concentration by sucking gas in the atmosphere and measuring the oxygen concentration,
(F) a step of high-frequency induction heating of the heated portion on the inner peripheral surface of the work under the anoxic condition; and (g) a step of heating the heated portion on the inner peripheral surface of the work to a predetermined quenching temperature. Stopping the high-frequency induction heating; and (h) stopping the injection of the gas after moving the heated portion of the work by a predetermined distance to a position facing the injection hole of the injection jacket for cooling the inner circumference of the work, Opening the work coolant discharge port of the work holding jig; and (i) simultaneously spraying the work coolant to the heated portion on the inner peripheral surface and the outer peripheral surface of the work heated to a predetermined quenching temperature. And rapidly cooling the inner peripheral surface.

The operation of the present invention is as follows. That is, the work coolant discharge port of the work holding jig is shielded,
The work coolant on the inner peripheral surface of the work is opposed to the high-frequency induction heating coil by storing the work cooling liquid sprayed from the spray jacket for cooling the outer periphery of the work in a liquid receiving tank mounted outside the work holding jig. At the position (heating position), the atmosphere chamber is completely shielded from the outside. An air suction port provided on the lower surface of the injection jacket for cooling the inner circumference of the work below the atmosphere chamber to replace oxygen (air) in the atmosphere chamber closed to the outside with an inert gas or a reducing gas in a short time. More oxygen (air) is exhausted to the outside for a predetermined flow rate and time, and at the same time, above the heating portion of the high-frequency induction heating coil facing the heated portion on the inner peripheral surface of the work, between turns of the high-frequency induction heating coil, and high-frequency induction. By injecting an inert gas or reducing gas at a predetermined pressure and flow rate from the lower side of the heating portion of the heating coil and the upper portion of the work toward the heated portion on the inner circumferential surface of the work, the inner circumferential surface of the work is The gas is caused to flow in a passage formed between the heated portion and the outer peripheral surface of the heating portion of the high-frequency induction heating coil, and accordingly, the inner peripheral surface of the work becomes anoxic.

The gas in the atmosphere chamber is suctioned from an oxygen concentration measuring suction pipe provided on the upper portion of the work in the vicinity of the heated portion on the inner peripheral surface of the work to measure the oxygen concentration.
It is confirmed that the heated portion has reached a predetermined oxygen concentration. After the atmosphere in the chamber is confirmed to have a predetermined oxygen concentration or less, the heated portion on the inner peripheral surface of the work is heated by the high frequency heating coil, and after the heating is completed, the heated portion of the work is cooled for the inner circumferential surface of the work. Move to the position facing the injection hole of the injection jacket, and then stop the injection of the inert gas or reducing gas, while the work coolant discharge port of the work holding jig is also blocked by the open / close valve, Since the atmosphere chamber is closed (the atmosphere chamber and the atmosphere are shielded) by the work coolant stored in the liquid receiving tank outside the work holding jig, the time from the end of heating until the work is cooled is extremely short. During this period, the atmosphere chamber maintains an oxygen-free state.

Thereafter, a work cooling liquid is injected from the injection jacket for cooling the inner circumference of the work and the injection jacket for cooling the outer circumference of the work to the heated portion on the inner peripheral surface and the outer peripheral surface of the work heated to a predetermined quenching temperature. At the same time, by opening the work coolant discharge port of the work holding jig, the work coolant ejected from the work inner circumference cooling spray jacket is discharged to the outside from the work coolant discharge port of the work holding jig, and The work coolant discharged from the work outer peripheral cooling spray jacket is discharged to the outside from a liquid receiving tank outside the work holding jig. Therefore, the quenching process in an oxygen-free state is performed automatically and continuously for a short time.

[0014]

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 FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 shows an oxidation-free induction hardening apparatus 100 used for performing an oxidation-free induction hardening method according to an embodiment of the present invention. In the present embodiment, the work (hardened body) W to be subjected to non-oxidizing (oxygen-free) quenching is a ring gear 1 as shown in FIGS.
0, and the non-oxidizing and quenching-processed portion (the portion to be heated) is a portion indicated by oblique lines α in FIG. 3, that is, the gear portion 11 formed on the inner peripheral surface of the ring gear 10. Thus,
The device 100 includes a gear portion 11 on the inner periphery of the ring gear 10.
This is used to form a quench hardened layer A (see FIG. 3) on the (work inner peripheral surface) by non-oxidative quenching.

A non-oxidizing induction hardening apparatus 1 according to the present embodiment.
Reference numeral 00 denotes a box-shaped work holding jig 20 for holding the work W (ring gear 10) at a predetermined position, a liquid receiving tank 21 disposed so as to surround the outside of the work holding jig 20, A high-frequency induction heating coil 30 that is disposed corresponding to the gear portion 11 on the inner peripheral surface and that performs high-frequency induction heating of the gear portion 11; and gas introduction pipes 41a to 41d that introduce an inert gas or a reducing gas into the gear portion 11. The gear unit 11 is disposed below the high-frequency induction heating coil 30.
Spray jacket 7 for cooling the inner circumference of the work that injects coolant
0, which is disposed above the high-frequency induction heating coil 30 to hold the high-frequency induction heating coil 30 and
1, a heating coil mounting plate 40 serving as an upper lid, and a base 5 for holding the heating coil mounting plate 40.
0, and an outer peripheral cooling spray jacket 60 attached to the lower portion of the base 50 and arranged corresponding to the outer peripheral surface of the work W.
Respectively.

A work W is held on the work holding jig 20 in a mounted state, and the work W is held together with the work holding jig 20 by a rotating mechanism and a lifting mechanism (not shown). Are configured to be rotationally driven and moved up and down. That is, as the rotating shaft 81 coaxially connected to the work holding jig 20 is driven to rotate by a rotating mechanism (not shown), the work W is driven to rotate about its axis, and the rotating shaft 81 The workpiece W is moved up and down along its axis along with the vertical movement of the workpiece W by a lifting mechanism (not shown).

At the lower part of the work holding jig 20, there are provided work coolant discharge ports 22 at a plurality of locations at substantially equal intervals on the circumference, and these work coolant discharge ports 22 are provided. An on-off valve 80 that opens and closes is installed below the work holding jig 20. This on-off valve 80
Rod 8 slidably mounted on the axis of the rotating shaft 81
2, the on-off valve 80 is operated in response to the rod 82 being moved up and down by a cylinder or the like (not shown),
A plurality of work coolant discharge ports 22 are opened and closed simultaneously.

The above-described high-frequency induction heating coil 30
Is formed of a water-cooled copper pipe through which a cooling liquid is passed inside (hollow portion), and is formed concentrically with the work W to heat the surface of the gear portion 11 on the inner peripheral surface of the work W; An upper heating unit 31 and a lower heating unit 32 which are formed in a circular shape so as to have a predetermined gap with the surface of the gear unit 11 which is the surface to be heated. And a lead portion 33 for supplying a high-frequency current from the power supply 35. The high-frequency induction heating coil 30 is mounted and fixed to the heating coil mounting plate 40 by a suitable mounting structure, and the gas mounting pipes 41a to 41d are arranged on the heating mounting plate 40, respectively.

In this embodiment, as described later in detail, an inert gas or a reducing gas is supplied from a gas supply unit (not shown) to the above-described gas introduction pipes 41a to 41d, and these gas introduction pipes 41a to 41d are supplied. By injecting an inert gas or a reducing gas at a predetermined pressure and a predetermined flow rate onto the work heating surface via the, the oxidation of the heating surface of the gear portion 11 on the inner peripheral surface of the work W is prevented.

The gas introduction pipe 41a is disposed above the workpiece W, while the gas introduction pipe 41b is connected to a gas injection jacket 41e disposed below the heating coil mounting plate 40. A predetermined pressure and a predetermined flow rate of the inert gas or the reducing gas are injected from the gas injection hole 41e toward the upper part of the inner peripheral surface of the work. Further, the gas introduction pipe 41 c is provided with a magnetic force concentrating material 34 attached inside the high-frequency induction heating coil 30.
The gap between the heating sections 31 and 32 of the high-frequency induction heating coil 30 has a predetermined pressure and a predetermined flow rate that are not suitable for the central portion of the gear section 11 on the inner peripheral surface of the work W. The active gas or the reducing gas is configured to be injected. The gas introduction pipe 41d is connected to a gas injection jacket 70a disposed above the work inner peripheral cooling injection jacket 70, and the gas injection jacket 70a
A predetermined pressure and a predetermined flow rate of an inert gas or a reducing gas are injected from a to a lower portion of the gear portion 11 on the inner peripheral surface of the work W.

On the other hand, the spray jacket 70 for cooling the inner circumferential surface of the work for cooling the gear portion 11 on the inner circumferential surface of the work W has a large number of coolant injection holes 70b formed on the outer circumferential surface thereof. Coolant introduction pipe 7 on the inner surface of the work
1 is connected. An air suction pipe 72 is provided coaxially with the injection pipe 70 for cooling the inner circumference of the work and the cooling liquid introduction pipe 71 for the inner circumference of the work. Thus, in the present embodiment, in order to quickly and more uniformly replace the oxygen-containing air in the atmosphere chambers 101 and 102 with the inert gas or the reducing gas, the cooling jacket 70 for cooling the inner circumference of the work and the inner circumference of the work are used. A predetermined amount of air is exhausted to the outside of the atmosphere chambers 101 and 102 within a predetermined time by an air suction means 73 from a suction port 72a of an air suction pipe 72 arranged coaxially with a cooling liquid introduction pipe 71. Have been.

Further, when the gear portion 11 on the inner peripheral surface of the work W is subjected to high-frequency induction heating, the outer peripheral portion of the gear portion 11 on the inner peripheral surface of the work W is cooled while reducing the distortion of the work W. A method of heating the gear portion 11 on the inner peripheral surface of the work W is adopted. For this purpose, the outer peripheral work coolant is injected from the upper portion 61a of the outer peripheral work spray jacket 60 attached to the lower part of the base 50. Further, when cooling the gear portion 11 on the inner peripheral surface of the work W, in order to cool the work in a shorter time, the work cooling liquid is ejected from the injection jacket 70 for cooling the inner periphery of the work, and the outer peripheral surface of the work W is also cooled. The work coolant is sprayed from the lower portion 61b of the work outer peripheral cooling spray jacket 60.

Next, an operation and an operation when the inner peripheral surface of the work W is non-oxidized and quenched by the non-oxidized induction hardening apparatus 100 having the above-described configuration will be described below.

First, at the start of the quenching process, the work holding jig 20 is disposed at a position directly below the high-frequency induction heating coil 30 (a position not shown, which is separated from the high-frequency induction heating coil 30 by a predetermined distance below). In this position, the work W is fixedly held on the work holding jig 20 by means such as a loader. After the attachment of the work W to the work holding jig 20 is completed in this manner, the rotating shaft 81 is moved upward by an elevating mechanism (not shown) to move the gear portion 11 on the inner peripheral surface of the work W as shown in FIG. Is raised to a height position facing the high-frequency induction heating coil 30, and thereafter, the work W is rotationally driven about its axis by a rotational driving force transmitted from a rotating mechanism (not shown) to the rotating shaft.

Next, the work outer peripheral coolant flow rate adjusting valve 64a
The coolant around the work adjusted to a predetermined amount in
By switching the valve 5a to the valve open state, the coolant is supplied to the upper portion 61a of the injection jacket 60 for cooling the outer periphery of the work through the coolant introduction pipe 63a, and the coolant is supplied from the many coolant injection holes 61c of the upper portion 61a. It is injected toward the outer peripheral surface of W. At this time, the outer peripheral coolant L of the work falls on the outer peripheral surface of the work W and then falls and is stored in the liquid receiving tank 21 outside the work holding jig 20 (see FIG. 1). In order to compensate for the shortage of the work coolant in the liquid receiving tank 21 due to the lifting and lowering operation and the rotating operation of the work holding jig 20, the liquid receiving tank 21 has already been filled by the operation one cycle before this operation. A predetermined amount of coolant has accumulated.

Next, at the same time as the work outer periphery cooling liquid is jetted from the upper portion 61a of the work outer periphery cooling spraying jacket 60, the air suction pipe 73 is blown by the air suction means 73.
While sucking oxygen (air) in the atmosphere chamber 102 of the work holding jig 20 from the second air suction port 72a, the gas flow control valves 42a to 42d pass through the gas introduction pipes 41a to 41d.
The inert gas or reducing gas adjusted to a predetermined amount in d is switched to the open state of the solenoid valve 43 to switch the atmosphere chamber 10 to the open state.
1 and the gear portion 11 on the inner peripheral surface of the work W. In this state (while the outer peripheral coolant L is continuously injected from the upper portion 61a of the outer peripheral cooling spray jacket 60,
(A state in which gas is injected into the atmosphere chamber 101 and the gear portion 11 on the inner peripheral surface of the work W while sucking oxygen (air) from the air suction port 72a), and after a predetermined time elapses, air suction means Only the operation of 73 is stopped, and the injection of the coolant around the workpiece and the inert gas or the reducing gas is continued as it is.

At this time, a ring-shaped portion 62 protrudingly extended from the lower part of the injection jacket 60 for cooling the outer periphery of the work.
Is inserted (immersed) into the outer peripheral coolant L accumulated in the liquid receiving tank 21 as shown in FIG.
The lower part of the workpiece 1 is provided with the coolant L around the work and the ring-shaped part 6.
2 makes it shielded from the atmosphere. further,
Since the plurality of work coolant discharge ports 22 located below the work holding jig 20 are closed by the on-off valve 80, the atmosphere chamber 102 in the work holding jig 20 is also shielded from the atmosphere. Becomes

As described above, under the condition that the atmosphere in the atmosphere chambers 101 and 102 is completely shielded from the atmosphere, the work W
After the inert gas or the reducing gas is injected into the heated portion (the inner peripheral surface of the work) for a predetermined time, the gas in the atmosphere chamber 101 is sucked by operating the oxygen concentration measuring means 45, and the heating coil is heated. The oxygen concentration at the opening 44a of the oxygen concentration measurement suction pipe 44 installed on the mounting plate 40 is measured. Then, after confirming that the measurement result is equal to or lower than the predetermined oxygen concentration, a high-frequency current of a predetermined frequency is supplied from the high-frequency power supply 35 to the high-frequency induction heating coil 30, and thereby the gear portion on the inner peripheral surface of the work W 1
1 (the surface to be heated or the surface to be quenched) is subjected to high frequency induction heating to a predetermined quenching temperature for a predetermined time. At this time, the atmosphere chambers 101, 1 are connected through the gas introduction pipes 41a to 41d.
02 and the state in which the gas is injected into the gear portion 11 on the inner peripheral surface of the workpiece W are kept.

Thus, when the surface to be heated of the workpiece W reaches the predetermined quenching temperature, the power supply to the high-frequency induction heating coil 30 is stopped, and the high-frequency induction heating is terminated. Accordingly, the injection of the coolant from the upper portion 61a of the work outer periphery cooling spray jacket 60 is stopped, and the work W outer periphery cooling is stopped. At the same time as the power supply to the high-frequency induction heating coil 30 is stopped, the work holding jig 20 is lowered by an elevating mechanism (not shown), and a gear portion on the inner peripheral surface of the work W is used as shown in FIG. 11 is stopped at a height position facing the work inner peripheral cooling jacket 70.

The supply of the gas is continued through the gas introduction pipes 41a to 41d even before the work W is moved down from the high frequency induction heating position to the height position shown in FIG. 2 and stopped. As shown in FIG. 5, the atmosphere chamber 101 is kept shielded from the atmosphere by the work outer peripheral coolant L accumulated in the liquid receiving tank 21 and the ring-shaped portion 62 protruding below the work outer peripheral cooling spray jacket 60. . Further, the plurality of work coolant discharge ports 22 disposed below the work holding jig 20 are kept closed at the same time by the on-off valve 80, whereby the atmosphere chamber 102 in the work holding jig 20 is closed. Is shielded from the atmosphere. As described above, the work W is completely shielded from the atmosphere for a short time from the end of the heating to the start of the cooling. Therefore, the work W is kept in the gas atmosphere state without being in contact with the air during this time. Is placed.

Next, the gear portion 11 on the inner peripheral surface of the work W is stopped at the height position facing the inner circumferential cooling jacket 70, and at the same time, the solenoid valve 76 and the solenoid valve 65b are switched to the open state. As a result, the work coolant is supplied into the work inner circumference cooling spray jacket 70 through the work inner circumference cooling liquid introduction pipes 74 and 71, and the work inner circumference cooling spray jacket 70 is supplied.
The work coolant adjusted to a predetermined amount and pressure by the work inner circumferential coolant flow rate adjusting valve 75 is injected from the coolant spray hole 70b of the work W into the gear portion 11 on the inner circumferential surface of the work W, while cooling the work outer circumferential surface. The work coolant is supplied into the lower portion 61b of the work outer peripheral cooling spray jacket 60 through the liquid flow rate adjusting valve 64b and the work outer circumferential coolant injection pipe 63b, and a plurality of cooling operations of the lower portion 61b of the work outer circumferential cooling spray jacket 60 are performed. From the liquid injection hole 61d, the coolant flow control valve 6 for the outer periphery of the work
The work coolant adjusted to a predetermined amount and pressure in 4b is sprayed onto the outer surface of the work W.

Further, as the electromagnetic valve 43 is switched to the closed state simultaneously with the injection of the work coolant, the injection of the inert gas or the reducing gas is stopped, and the lower part of the work holding jig 20 is stopped. The on-off valve 80 is moved to a valve-opening position by raising a rod 82 connected to a cylinder or the like (not shown).
), And a plurality of work coolant discharge ports 22 are opened accordingly.

Thus, when the work coolant discharge port 22 is opened, the work inner peripheral coolant ejected from the coolant ejection holes 70 b of the work inner periphery cooling spray jacket 70 is discharged to the lower part of the work holding jig 20. The liquid is discharged to the outside of the atmosphere chamber 102 through a plurality of coolant cooling liquid outlets 22 located therein. In addition, as shown by an arrow β in FIG. 2, the outer peripheral work liquid of the work injected from the cooling liquid injection hole 61d of the lower portion 61b of the outer peripheral work cooling jacket 60 is cooled by the inner peripheral surface of the liquid receiving tank 21 and the outer peripheral work of the work. Injection jacket 60
It is discharged to the outside through the space between the ring-shaped portion 62 and the outer peripheral surface. Then, after cooling for a predetermined time, the solenoid valves 76 and 65b for supplying and shutting off the inner peripheral coolant and the outer peripheral coolant of the work are respectively switched to the closed state, and the injection of the work coolant is stopped, and quenching is performed. The process ends.

Thereafter, the work holding jig 20 is lowered to a predetermined position, the rotation thereof is stopped, and the quenched work W is removed from the work holding jig 20 by means such as a loader (not shown).

The non-oxidizing induction hardening is completed by the above-described series of operation procedures, and the quenched work W is transferred to the next step.

The non-oxidizing induction hardening apparatus 1 having such a configuration
According to 00, the atmosphere chamber 10 that performs high-frequency heating and cooling
1, 102, a work holding jig 20 having a liquid receiving tank 21 for storing a work cooling liquid, a high frequency induction heating coil 30, a heating coil mounting plate 40, a base 50, and a spray jacket for cooling the outer periphery of the work. 60, when the inner peripheral surface or the outer peripheral surface or the end surface of the work W (for example, the ring gear 10) whose both end surfaces have an open shape is induction hardened in a short time, automatically and continuously. Oxidation quenching can be performed.

The work holding jig 20 itself is in the atmosphere chamber 10.
1 and 102, the formation of the atmosphere chambers 101 and 102 is canceled when the work holding jig 20 moves up and down, so that the work can be easily transferred to another position.

Further, the above-described non-oxidizing induction hardening apparatus 10
0, the work holding jig 20 on which the work W is placed and fixed moves, and accordingly, the atmosphere chamber 10 in a closed state is moved.
When the gas chambers 1 and 102 are formed, oxygen (air) in the atmosphere chambers 101 and 102 can be exhausted in a short time, and then the inert gas or the reducing gas is purged from the atmosphere chambers 101 and 102.
By feeding an inert gas or a reducing gas into the atmosphere chambers 101 and 102 while exhausting oxygen (air).
02 can be replaced with an inert gas or a reducing gas. Accordingly, the work W is induction-heated in a high-frequency atmosphere in this oxygen-free atmosphere and rapidly cooled with a work cooling liquid, so that the non-oxidative quenching can be efficiently performed in an extremely short time and by an automatic continuous operation. It is possible to do.

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 inner surface (the gear portion 11 on the inner peripheral surface) of the work W (ring gear 10) whose both end surfaces have an open shape is quenched. The present invention is also applicable to the case of quenching or the case of quenching the outer surface or end surface of a solid workpiece. Further, it goes without saying that the present invention can be used for induction hardening, induction annealing, and the like.

[0041]

As described above, the induction hardening method and apparatus of the present invention utilize the work coolant for sealing the atmosphere chamber and discharge the work coolant flowing into the work holding jig to the outside. The opening / closing valve is provided on the work holding jig, so that an atmosphere chamber with an extremely high degree of sealing can be formed. Further, in addition to the high degree of sealing of the atmosphere chamber, an inert gas or a reducing gas is supplied to the atmosphere after exhausting oxygen-containing air from the atmosphere chamber to the atmosphere or while discharging oxygen (air) in the atmosphere chamber to the outside. Since it is introduced into the room, it is possible to perform induction hardening without oxidation in an oxygen-free atmosphere.

Further, in the present invention, an air suction port for exhausting oxygen-containing air to the outside is provided inside the work holding jig, and a gas injection hole for injecting the gas into the atmosphere chamber is provided in the work holding jig. Since it is arranged at the upper part, the only gap existing between the air suction port and the gas injection hole is between the outer peripheral surface of the heating portion of the high frequency induction heating coil and the heated surface of the inner peripheral portion of the work. Only the gap formed at Therefore, when oxygen (air) in the atmosphere chamber is discharged to the outside, the gas is also discharged to the outside through the heated surface of the inner peripheral portion of the work, and the oxygen concentration in the entire atmosphere chamber is gradually and uniformly reduced. Therefore, after a predetermined time, almost the entire atmosphere chamber can be filled (replaced) with the gas. Furthermore, at that stage, stop the oxygen (air) suction,
By injecting only the gas to the heated portion of the work, the heated portion of the work can be made ideally oxygen-free. Further, by measuring the oxygen concentration near the heated portion of the work, it can be confirmed whether or not the work is heated in a favorable atmosphere.

In the non-oxidizing high-frequency heat treatment apparatus according to the present invention, the upper part of the atmosphere chamber is a heating coil mounting plate, the outer peripheral part is a spray jacket for cooling the outer peripheral part of the work, and the lower part is a work holding jig and a work cooling fluid. Since the liquid chamber is constituted by a liquid receiving tank, the entire volume of the atmosphere chamber can be reduced, and the time for replacing oxygen (air) with the gas can be shortened. Moreover, despite the fact that the work holding jig is moved downward between the time when the heating is stopped and the time when the cooling is started, the atmosphere chamber is completely open to the outside, and the atmosphere chamber is kept completely oxygen-free. be able to. Therefore, the atmosphere chamber can be formed in accordance with the vertical movement of the work holding jig, and the high frequency heat treatment can be automatically and continuously performed under a completely oxygen-free state in this atmosphere.

Therefore, according to the present invention, there is provided a practical non-oxidizing high-frequency heat treatment method and apparatus capable of automatically and continuously performing high-frequency heat treatment such as induction hardening in an oxygen-free atmosphere in a very short time. Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of an oxidation-free high-frequency heat treatment apparatus according to an embodiment of the present invention, and showing a state where a work is installed at a heating position.

FIG. 2 is a cross-sectional view illustrating a state where a work is installed at a cooling position in the above-described non-oxidizing high-frequency heat treatment apparatus.

FIG. 3 is a longitudinal sectional view of a ring gear used in the present invention.

FIG. 4 is a longitudinal sectional view showing a conventional high-frequency non-oxidizing and quenching apparatus.

[Explanation of symbols]

 Reference Signs List 10 ring gear (work) 11 gear part 20 work holding jig 21 liquid receiving tank 22 work cooling liquid discharge port 30 high-frequency induction heating coil 35 high-frequency power supply 40 heating coil mounting plate 41a to 41d gas introduction pipe 42a to 42d gas flow control valve 43 Solenoid valve 44 Suction pipe for oxygen concentration measurement 45 Oxygen concentration measurement means 50 Base 60 Injection jacket for cooling the outer circumference of the work 64a, 64b Valve for controlling the flow rate of the coolant around the outer circumference of the work 65a, 65b Solenoid valve 70 Injection jacket for cooling the inner circumference of the work 70a Gas Injection jacket 70b Coolant injection hole 72 Air suction pipe 72a Air suction port 73 Air suction means 75 Work inner circumference coolant flow control valve 76 Solenoid valve 80, 80a Open / close valve 81 Rotary shaft 100 Non-oxidizing induction hardening device 101, 102 Atmosphere Chamber A Hardened layer L Work coolant W Work

Continued on the front page. (72) Inventor Shuji Arata 4-1-1 Kasugadai, Aikawa-cho, Aiko-gun, Kanagawa Prefecture Nakatsu dormitory for electric industry (72) Inventor Akihiko Miyaji 10 Takane, Fujii-cho, Anjo-shi, Aichi Aisin AW (56) References JP-A-5-51631 (JP, A) JP-A-5-1320 (JP, A) JP-A-3-170617 (JP, A) JP-A-61-76611 (JP, A) A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C21D 1/10 C21D 1/667 H05B 6/10 331

Claims (7)

(57) [Claims] A work held by a vertically movable work holding jig is arranged in an atmosphere chamber containing an inert gas or a reducing gas, and a heated portion of the work is subjected to high-frequency induction heating. In the non-oxidizing high-frequency heat treatment method in which a work coolant is sprayed onto a heated portion of the work to cool the work, during high-frequency induction heating, the work coolant is stored in a liquid receiving tank attached to the work holding jig. While shielding the atmosphere chamber from the atmosphere with the work coolant stored in the liquid receiving tank, an on-off valve is installed at a work coolant discharge port provided on the work holding jig, and the on-off valve is used for the on-off valve. The atmosphere chamber is shielded from the atmosphere, and at the time of cooling, the on-off valve is switched to the open state, thereby discharging the work coolant stored in the work holding jig to the outside of the work holding jig. Wherein an atmosphere chamber is formed in the workpiece holding jig. In the step of high-frequency induction heating of a heated portion of the workpiece, oxygen-containing air is exhausted from the atmosphere chamber to the atmosphere, and then an inert gas or a reducing gas is fed into the atmosphere chamber. An inert gas or a reducing gas is sent into the atmosphere chamber while the air is exhausted from the atmosphere chamber to the atmosphere, thereby replacing the atmosphere in the atmosphere chamber with the inert gas or the reducing gas. The non-oxidizing high frequency heat treatment method according to claim 1. 3. In the step of high-frequency induction heating of a heated portion of the work, the oxygen concentration in the atmosphere chamber is measured by using an oxygen concentration measurement suction pipe disposed in the atmosphere chamber. 3. The non-oxidizing high frequency heat treatment method according to claim 1, wherein the atmosphere in the atmosphere chamber is confirmed to have a predetermined oxygen concentration or less. 4. The non-oxidizing high-frequency heat treatment method according to claim 1, wherein the work is transferred to a cooling position while maintaining an oxygen-free state after the high-frequency induction heating of the work. . 5. An inner surface of a work having both open ends.
The non-oxidizing high frequency heat treatment method according to any one of claims 1 to 4, wherein the outer surface or the end surface is subjected to high frequency heat treatment. 6. A work held by a vertically movable work holding jig is placed in an atmosphere chamber containing an inert gas or a reducing gas, and a heated portion of the work is subjected to high-frequency induction heating. (A) A box-shaped jig for holding the work at a predetermined position, wherein the jig is a non-oxidizing high-frequency heat treatment apparatus configured to spray a work cooling liquid onto a heated portion of the work to cool the work. (B) a work holding jig having a work coolant discharge port for discharging the work coolant stored therein to the outside of the jig, and an open / close valve for opening and closing the work coolant discharge port; A high frequency induction heating coil for high frequency induction heating of a heated portion of the work; (C) a work coolant spray jacket for spraying a work coolant to the work; From click coolant injection jacket to accumulate workpiece coolant injected into the workpiece,
A liquid receiving tank disposed so as to surround the outer periphery of the work holding jig, (E) an air suction pipe for discharging oxygen-containing air to the outside of the atmosphere chamber, and (F) an inert gas for the work. Or a gas introduction pipe for introducing a reducing gas, respectively, by inserting a ring-shaped portion extending to the work coolant spray jacket into the work coolant stored in the liquid receiving tank. An oxidation-free high-frequency heat treatment apparatus, wherein the atmosphere in the atmosphere chamber is cut off from the atmosphere. 7. A work held by a vertically movable work holding jig is arranged in an atmosphere chamber having an inert gas or a reducing gas as an atmosphere, and a heated portion of the work is subjected to high-frequency induction heating. (A) A box-shaped jig for holding the work at a predetermined position, wherein the jig is a non-oxidizing high-frequency heat treatment apparatus configured to spray a work cooling liquid onto a heated portion of the work to cool the work. A work coolant discharge port for discharging the work coolant stored in the jig to the outside of the jig, an open / close valve for opening and closing the work coolant discharge port, and a liquid receiving tank for storing the work coolant are provided. A work holding jig provided on the outside, and (B)
A high-frequency induction heating coil arranged corresponding to the work for high-frequency induction heating of a heated portion of the work, (C) an air suction pipe for discharging oxygen-containing air to the outside of the atmosphere chamber, and the air suction pipe An air suction mechanism connected to the air suction mechanism configured to apply suction force,
(D) a gas introduction pipe for introducing an inert gas or a reducing gas into the work, a gas flow control valve for adjusting a flow rate of the gas flowing through the gas introduction pipe, and a gas opening and closing the gas introduction pipe. (E) a gas suction pipe for measuring oxygen concentration in the atmosphere chamber, and a gas introduction mechanism constituted by an electromagnetic valve for supplying or shutting off oxygen, and a gas suction pipe connected to the gas suction pipe for measuring oxygen concentration. (F) a work coolant having a ring-shaped portion inserted into the work coolant in the liquid receiving tank so as to shut off the atmosphere in the atmosphere chamber from the atmosphere. Injection jacket, work coolant introduction pipe for introducing work coolant to the work coolant ejection jacket, work coolant flow rate for adjusting the flow rate of work coolant flowing through the work coolant introduction pipe Seiben, and, non-oxidizing induction heat treatment apparatus characterized by comprising said the workpiece cooling mechanism consists solenoid valve to open and close the workpiece coolant inlet pipe for supplying or interrupting the work coolant, respectively.