JPH08337821A - Method for quenching chip saw basis metal for circular saw and device therefor - Google Patents

Abstract

PURPOSE: To obtain a highly precise and uniformly quenched quality by heating a prescribed annular part of a basis metal with a laser beam and cooling. CONSTITUTION: A cover moving device 6 is operated by a control signal of a control unit 10, and an upper cover 5a is risen to set a gap between a lower cover 5b and the upper cover. A center hole 2a of the basis metal 2 is inserted into a projecting part 3a of a basis stand 3. The upper cover 5a is abutted on the lower cover 5b to closely shut the inner part of a cover 5, and an inert gas is supplied from a gas supplying device 9. The laser beam is emitted by rotating the basis metal 2, and also, operating a laser beam device 7. The laser beam is made incident into the cover 5 from an incident window 11 through a condenser lens 16, and irradiates the basis metal 2 and heats it in an annular- state. Thereafter, a cooling medium supplying device 8 is operated to open a medium supplying valve 14, and cooling water is supplied to the inner part of the cover 5. The basis metal 2 is quenched by this water cooling. Thus, the quenching cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for quenching a circular saw tip saw base metal and an apparatus for the same, in which a tip is brazed and fixed to an outer peripheral portion.

[0002]

2. Description of the Related Art Conventionally, a circular saw tip saw used for cutting grass, cutting wood, etc. has a disc-shaped base metal made of a material such as SKS and is formed on the outer peripheral portion of the base metal. A chip made of cemented carbide is brazed and fixed to a chip mounting portion including a stepped portion and a recess. Then, the base metal is generally subjected to quenching treatment in order to prevent a buckling phenomenon and the like, and as an apparatus therefor, for example, Japanese Patent Publication No. 3-40085.
As disclosed in the publication, a high-frequency induction heating type quenching device is known.

This quenching apparatus comprises an upper die that can move up and down,
A lower die on which a mounting table is arranged is provided, and a heating coil connected to a high-frequency transformer is arranged between the upper and lower dies so that the heating coil can be moved back and forth by the transfer means. Then, after setting the base metal on the mounting table, position the heating coil on the upper and lower surfaces of approximately half of the base metal, and while rotating the base metal, supply a high frequency current from the high frequency transformer to the heating coil to remove the base metal. Induction heating to a specified temperature. After that, the heating coil is withdrawn from between the molds, the upper mold is lowered, and the base metal heated by the upper and lower molds is pressed into a pressed state, and cooling oil is supplied in this state to rapidly cool the base metal. Let it harden.

[0004]

However, in this quenching apparatus, since induction hardening of high frequency is used, the quenching portion is largely influenced by the shape of the heating coil, and the quenching portion should be controlled with high accuracy. Then, the shape of the heating coil is required to have high accuracy, and the cost of the heating coil increases. In addition, the positional relationship between the heating coil and the base metal must be managed with high accuracy, which makes the quenching work troublesome and raises the quenching cost as a whole and provides uniform quenching quality. There was a problem of difficulty.

The present invention has been made in view of such circumstances, and an object thereof is a quenching method for a circular saw tip saw base metal capable of reducing quenching cost and obtaining uniform quenching quality. And to provide the device.

[0006]

In order to achieve the above object, a method for quenching a circular saw tip saw base metal according to claim 1 is
A base metal having a tip mounting portion on the outer periphery is rotatably set, the base metal is rotated while irradiating a laser beam on one surface of the base metal, and a predetermined ring portion of the base metal is laser-heated, The base metal is then quenched by cooling the annular portion.

Further, in a quenching device for a circular saw tip saw base metal according to a second aspect of the present invention, there is provided a base on which a base metal having a tip mounting portion on the outer periphery is rotatably set, and a base metal set on the base. It is characterized by comprising a laser device for irradiating a laser beam on one surface and a rotating means for rotating the base metal.

Further, in the quenching apparatus according to the third aspect of the invention, there is provided a base on which a base metal having a chip mounting portion on the outer peripheral portion is rotatably set, a cover enclosing the base metal in a substantially sealed state, and a cover. A laser device for irradiating one surface of the base metal with a laser beam through the beam entrance window and a cooling medium supply device for supplying a cooling medium into the cover are provided.

[0009]

According to the method for quenching a circular saw tip saw base metal according to claim 1, the rotatable base metal is irradiated with a laser beam while rotating the base metal. The annular portion is laser-heated. By cooling the heated base metal, the base metal is hardened, for example, put into the waist.

According to the quenching device for a circular saw tip saw base metal according to a second aspect of the present invention, the base metal set on the base is placed on one surface of the laser device at a predetermined radial position to be hardened. A laser beam is emitted from the laser to heat the laser. The base metal is
The circular portion is laser-heated by being rotated by the rotating means, and the heated base metal is cooled, so that the base metal is quenched and put into the waist.

According to the quenching apparatus of the third aspect,
A base metal set on the base is surrounded by a cover, and a laser beam is irradiated into the cover through a beam entrance window of the cover.
The laser beam is applied to a predetermined position in the radial direction of the base metal,
By rotating the base metal, the ring portion of the base metal is laser-heated, and the base metal is quenched by cooling the heated base metal with the cooling medium supplied from the cooling medium supply means. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. 1 and 2 show a quenching device for a circular saw tip saw base metal according to the present invention. FIG. 1 is a schematic configuration diagram thereof, and FIG. 2 is a plan view of the base metal. In FIG. 1, a quenching apparatus 1 includes a base 3 on which a base metal 2 is set, a motor 4 for rotating the base 3, and a cover 5 surrounding the base metal 2 set on the base 3. A cover moving device 6 that moves the cover 5, a laser device 7 that irradiates a laser beam into the cover 5, a cooling medium supply device 8 that supplies a cooling medium into the cover 5, and an inert gas inside the cover 5. It has a gas supply device 9 for supplying, a control device 10 for controlling the motor 4, the cover moving device 6, the laser device 7, the cooling medium supply device 8 and the gas supply device 9.

The cover 5 includes an upper cover 5a and a lower cover 5b.
And the upper cover 5a is connected to the cover moving device 6. The upper cover 5a moves up and down in the direction of arrow A when the cover moving device 6 is activated by a control signal from the control device 10, and the upper cover 5a is lifted to move the upper cover 5a.
Is separated from the lower cover 5b. A beam entrance window 11 is provided on the upper cover 5a.
The position 1 is preset according to the diameter of the base metal 2 set in the cover 5.

The upper cover 5a has a gas supply valve 12
A gas discharge valve 13 is provided, and the gas supply valve 12 is connected to the gas supply device 9. The gas discharge valve 13 operates when the pressure inside the cover 5 reaches a predetermined pressure, and maintains the pressure inside the cover 5 constant.

On the other hand, the medium supply valve 14 is attached to the lower cover 5b.
A medium discharge valve 15 is provided, and a cooling medium supply device 8 is connected to the medium supply valve 12. The cooling medium supply device 8 is operated when the upper cover 5a is lowered and the lower end thereof is brought into contact with the lower cover 5b so that the inside of the cover 5 is in a substantially hermetically sealed state. Supply water. The medium discharge valve 15 is opened by a control signal from the control device 10 to discharge the cooling water in the cover 5 to the outside. As the cooling medium, an appropriate medium such as cooling gas or oil other than cooling water is used.

As the laser device 7, for example, a CO 2 laser device is used, and the laser beam emitted from this device is emitted from the beam entrance window 11 of the cover 5 into the cover 5 through the condenser lens 16. As the laser to be used, a YAG laser can be used instead of the CO2 laser.

Next, a method of quenching the base metal 2 by the quenching apparatus 1 will be described. First, the cover moving device 6 is operated by the control signal of the control device 10 to move the upper cover 5a.
To raise a predetermined gap with the lower cover 5b. In this state, the hole 2a in the central portion of the base metal 2 is fitted into the convex portion 3a of the base 3, and the base metal 2 is set on the base 3 in a substantially horizontal state.

Then, according to the control signal of the control device 10,
The upper cover 5a is lowered and brought into contact with the lower cover 5b to make the inside of the cover 5 in a substantially sealed state. In this state, the gas supply device 9 is operated and the gas supply valve 12 is opened so that the inside of the cover 5 is filled with argon gas. An inert gas such as nitrogen gas is supplied for a predetermined time. When the inert gas is supplied for a predetermined time, the inside of the cover 5 is gas-replaced so that the cover 5 is in an unoxidized state.

Next, in response to a control signal from the control device 10, the motor 4 is rotated to rotate the base metal 2 and the laser device 7 is operated to emit a laser beam. This laser beam is made incident on the inside of the cover 5 through the beam entrance window 11 through the condenser lens 16 and is applied to a predetermined portion of the rotating base metal 2. The base metal 2 is laser-heated by this laser beam, its surface rises to a predetermined temperature (quenching temperature), and this heated portion is irradiated with the laser beam while the base metal 2 rotates, It becomes a ring.

When the base metal 2 is laser-heated in an annular shape, the operation of the laser device 7 is stopped by the control signal of the control device 10, and then the cooling medium supply device 8 is operated and the medium supply valve 14 is opened. Then, cooling water is supplied into the cover 5. By supplying this cooling water, the gas in the cover 5 is discharged to the outside from the gas discharge valve 13,
The heated base metal 2 is rapidly cooled by the cooling water supplied therein, and as shown in FIG. 2, the quenched portion Y of the base metal 2 is quenched into an annular shape. At this time, the base metal 2 is quenched in an unoxidized state, so that the scale and the like are surely prevented from being generated.

Then, when a predetermined amount of cooling water is supplied, the operation of the cooling medium supply device 8 is stopped, the medium supply valve 14 is closed, and the medium discharge valve 15 is opened. Medium discharge valve 1
By opening 5, the cooling water in the cover 5 is discharged to the outside. When the cooling water in the cover 5 is discharged, the cover moving device 6 is operated by the control signal of the control device 10 to raise the upper cover 5a and separate it from the lower cover 5b. Then, by removing the base metal 2 from the base 3, the quenching work of one base metal 2 is completed.

In this embodiment, the inside of the cover 5 is made non-oxidized by using the inert gas. However, for example, the gas supply device 9 may be omitted and the quenching may be simply performed in the atmosphere. Alternatively, the cooling medium supply device 8 may be omitted and the base metal 2 may be cooled by natural cooling.

As described above, in the above quenching method,
Since the base metal 2 is set on the base 3 and the surface of the base metal 2 is hardened by irradiating it with a laser beam while rotating the base metal 2, there is no need for a heating coil whose shape requires high precision. Accordingly, it is not necessary to manage the positional relationship between the heating coil and the base metal 2 and the quenching range can be easily set by adjusting the laser beam. As a result, the quenching work can be performed easily and easily, and the quenching cost can be reduced.

Further, by appropriately adjusting the laser beam, the surface of the base metal 2 in the quenching portion is not melted and the roughness due to the melting is not generated, and local heating for heating the annular portion of a predetermined width is performed. It is possible to minimize the influence on other parts, and since the input heat quantity and power can be reduced by partial heating, the cooling rate can be increased and the quenching part Y It is possible to obtain a highly accurate quenching quality such as the position of can be controlled with high precision, and it is possible to perform quenching of uniform quality.

Further, by using the laser beam, there is no atmospheric limitation, and it is possible to perform quenching in an atmosphere most suitable for quenching, for example, argon gas, and also quenching in the atmosphere is easy. In addition to being able to perform, it is possible to perform clean quenching without pollution. Further, a press machine, a large electric furnace for quenching, etc. are not required, the quenching apparatus 1 can be constructed at low cost, and maintenance of the quenching apparatus 1 becomes easy.

In the above embodiment, the base metal 2 is hardened into an annular shape. However, as shown in FIG. 3, for example, by controlling the irradiation of laser light, the hardened portion Y is entirely circular. It may be quenched so as to present an annular shape, or base metal 2
It is also possible to quench the entire area within and outside the radius of a predetermined distance from the center of. The configuration of the quenching device and the quenching method in the above embodiment are also examples, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0027]

As described in detail above, in the method for quenching a circular saw tip saw base metal and the apparatus therefor according to the present invention, a heating coil and the like are not required, and the quenching cost can be reduced. By the laser heating, it is possible to obtain effects such as obtaining highly accurate and uniform quenching quality.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a quenching device for a circular saw tip saw base metal according to the present invention.

[FIG. 2] A plan view of the quenched base metal.

FIG. 3 is a plan view of another base metal.

[Explanation of symbols]

 1 quenching device 2 base metal 3 base 4 motor 5 cover 6 cover moving device 7 laser device 8 cooling medium supply device 9 gas supply device 10 control device 11 beam entrance window Y quenching part

Claims (3)

[Claims] 1. A predetermined ring of a base metal, wherein a base metal having a chip mounting portion on its outer periphery is rotatably set, and the base metal is rotated while irradiating a laser beam on one surface of the base metal. A method for quenching a circular saw tip saw base metal, characterized in that the base metal is quenched by laser heating the portion and then cooling the annular portion. 2. A base on which a base having a chip mounting portion on its outer periphery is rotatably set, a laser device for irradiating a laser beam on one surface of the base set on the base, A circular saw tip saw base metal quenching device, comprising: a rotating means for rotating the base metal. 3. A pedestal on which a base metal having a chip mounting portion on its outer periphery is rotatably set, a cover surrounding the base metal in a substantially sealed state, and the base via a beam entrance window of the cover. A laser device that irradiates one side of gold with a laser beam,
And a cooling medium supply device that supplies a cooling medium into the cover.