JPH06346136A - Quenching apparatus in liquid - Google Patents

Abstract

PURPOSE:To provide a quenching apparatus in liquid, by which the quenching can uniformly be applied so that the property of a work is uniformized. CONSTITUTION:To a work supporting table 8 arranged in a cooling liquid vessel 2 in the quenching apparatus into liquid, a work holding tool 13 for holding the work M is hinged so as to be freely rotatable. A DC electric motor 31 is connected with the work holding tool 13, and high-frequency induction quenching is applied with a heating heater 7 while rotating the work M in the condition of dipping into the cooling liquid W with the DC electric motor 31. The work M does not develop uneven quenching because of the rotation- driving with the DC electric motor 31, and since the revolutional speed of the Dc electric motor 31 is controlled through revolutional speed controlling mechanism, the cooling speed of the work M can be controlled, and the flow speed of convection developed in the cooling liquid can be adjusted, and the quenching hardened layer at the prescribed depth to the work M can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a submerged quenching apparatus used for induction hardening.

[0002]

2. Description of the Related Art Conventionally, induction hardening is carried out by applying a high-frequency current to a hardening coil and utilizing induction heating generated on the surface of the work adjacent to the hardening coil to perform hardening on the work surface. There is. This induction hardening is for intensive hardening at the desired location on the work,
In order to prevent quenching distortion, the work may be performed while being immersed in a cooling liquid.

As an apparatus for subjecting a work to induction hardening in a cooling liquid as described above, Japanese Patent Application Laid-Open No. 62-10702 is disclosed.
There is a submerged quenching apparatus described in Japanese Patent Laid-Open No. This device
A workpiece is held by a component holder that is rotatably supported by a component support table arranged in a coolant tank that stores the coolant,
The workpiece is held by the component receiver while rotating the workpiece by injecting a liquid flow to a fan provided on the pivot of the component receiver to perform induction hardening on the workpiece with a heating coil.

Therefore, in this apparatus, by jetting the liquid flow from the liquid jet nozzle, a convection is forcibly caused in the cooling liquid to stir the cooling liquid whose liquid temperature has risen due to the heat of quenching, and the work is It is intended to prevent the occurrence of quenching unevenness caused by using a heating coil which is rotated to have a normal plan view circular shape.

[0005]

However, in this apparatus, since the work is rotated by utilizing the liquid jet from the liquid jet nozzle, the convection speed of the cooling liquid and the rotation speed of the work are not stable. Therefore, the cooling rate of the work by the cooling liquid becomes unstable, the quench-hardened layer cannot be formed on the work at a desired constant depth, and the occurrence of quenching unevenness cannot be completely prevented. There is a problem that the physical properties vary. Therefore, an object of the present invention is to provide an in-liquid quenching apparatus that can perform quenching processing so that the physical properties of a quenched workpiece are uniform.

[0006]

According to a first aspect of the present invention, there is provided a submerged quenching apparatus for quenching a work immersed in a cooling fluid with a heating coil in a cooling fluid tank for storing the cooling fluid. A work support table disposed on the work support table, a work support tool pivotally supported by the work support table to hold the work, an electric motor for rotationally driving the work support tool, and an electric motor of the electric motor. And a rotation speed control means for controlling the rotation speed.

[0007]

In the submerged quenching apparatus of the present invention, since the work held by the work holder is driven to rotate by the electric motor, the rotation speed of the electric motor is controlled by the rotation speed control means. Since the flow velocity of convection that occurs in the cooling liquid is adjusted, the cooling rate of the work can be controlled, so that it becomes possible to form a quench hardening layer of a desired constant depth on the work. Moreover, since the work is rotated without uneven rotation, uneven hardening does not occur.

[0008]

As described above, according to the submerged quenching apparatus of the present invention, the work holder for holding the work is
It is driven to rotate by an electric motor, and its rotation speed is adjustable by a rotation speed control mechanism. Therefore, the workpiece is rotated evenly, and the rotation speed of the motor is controlled so that the cooling liquid is generated. It is possible to adjust the flow velocity of convection that occurs. Therefore, the work is uniformly hardened without causing uneven hardening,
The cooling rate of the work can be controlled, and a quench hardening layer having a desired depth can be formed on the surface of the work.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, a liquid quenching apparatus of the embodiment will be described with reference to the drawings. In this embodiment, a liquid for induction hardening the inner surface of a through hole a of a work M having through holes a such as gears and rings. This is a case where the present invention is applied to a medium quenching device. As shown in FIGS. 1 and 2, this submerged quenching apparatus includes a cooling liquid tank 2 fixed on a base frame 1, a machine base 3 adjacent to the cooling liquid tank 2, and an air cylinder 4
And a high-frequency heating device 5 which is arranged so as to be movable up and down.

The high-frequency heating device 5 includes a power supply 6 for supplying a high-frequency current, and a heating coil having a circular shape in plan view for quenching the work M by high-frequency induction heating with the high-frequency current supplied from the power supply 6. 7 and 7. A cooling liquid W made of an aqueous solution of ethylene glycol or polyvinyl alcohol is stored in the cooling liquid tank 2, and a disk-shaped work support 8 is arranged in a state of being immersed in the cooling liquid W.

The work support base 8 is rotatably supported by a bearing 9 provided at the bottom of the cooling liquid tank 2 via a support shaft 10, and a connecting tool 12 is provided at the lower end of the support shaft 10. A gear mechanism 14 that is provided and is connected to the index motor 11 via a chain 13 is provided at a lower end portion of the connecting tool 12.
Are connected to each other, and the work support base 8 is indexed and rotated at every rotation angle of 45 degrees by the rotation of the index motor 11. Further, eight work holders 13 are vertically movable on the peripheral portion of the work support base 8 so that they can be moved up and down.
It is supported at an indexing angle position of 5 degrees, that is, a position at which the circumference is divided into eight.

As shown in FIG. 3, the work holder 13 holds the work M, and a work holding portion 14 for fitting the work M on the upper surface of the peripheral wall 13a of the holder main body having a cylindrical shape with a bottom. Is formed, the shaft portion 15 is formed downward from the bottom wall 13b.
The shaft portion 15 is rotatably supported via a bearing 18 in a bearing cylinder 17 that is vertically inserted through a bearing 16 attached to the work support 8.

Further, the shaft portion 15 of the work holder 13 is disposed on the bottom portion of the cooling liquid tank 2 so as to be inclined downward toward the high-frequency heating device 5 side and has an annular inclined track plate 19 in plan view.
When the work holder 13 is indexed and rotated by being supported above and the index motor 11 being rotationally driven, the shaft portion 1 is rotated.
The lower end of 5 is moved along the inclined surface of the inclined track plate 19, the shaft portion 15 moves up and down in the bearing cylinder 17, and the work holder 13 is moved up and down.

A drainage hole 20 is formed in the peripheral wall 13a of the work holder 13 in a direction orthogonal to the extension line of the shaft portion 15, and the work holder 13 rotates about the shaft portion 15 as a rotation center. When driven, centrifugal force acts on the cooling liquid around the through hole a of the work M held therein to cause convection, and as shown by the arrow in FIG. It is configured to be discharged to.

A timing pulley 21 is provided at the lower end portion of the shaft portion 15 of the work holder 13, and the timing pulley 21 is positioned immediately below the heating coil 7 by the indexing rotation of the index motor 11 (see a later-described processing position). 5
When the stage S5 position is reached, the work rotation drive mechanism 3
0, the work holder 13 is driven to rotate,
The work M held by this is configured to rotate.

The work rotation drive mechanism 30 will be described. As shown in FIGS. 1 to 4, a DC electric motor 31 disposed on the cooling liquid tank 2 and a lower end portion of the shaft portion 15 of the work holder 13 are provided. The transmission 3 attached to the DC electric motor 31 is interlocked with the timing pulley 21 provided in the
A drive pulley 34 is provided at the lower end of a drive shaft 33 that extends downward from 2, and a driven pulley 35 is disposed at a predetermined distance from the drive pulley 34. The synchro belt 36 is wound, and the shaft portion 15 of the work holder 13 is attached to the double-sided synchro belt 36.
Is engaged with the timing pulley 21 and the work holder 13 is driven to rotate as the DC electric motor 31 rotates.

As shown in FIG. 5, a rotation speed control device 40 is connected to the DC electric motor 31, and the rotation speed of the DC electric motor 31 can be controlled by the rotation speed control device 40. The rotation speed control device 40 is
A liquid temperature sensor 41 for detecting the liquid temperature of the cooling liquid, a keyboard 42 for inputting the size of the heating coil 7, the hardenability of the work M and the depth of the quench hardened layer, and a micro computer for calculating these input data. A control box 43 mainly composed of an input / output interface, and a motor drive circuit 4 for rotationally driving the DC electric motor 31 at a rotational speed set by a control signal from a micro computer incorporated in the control box 43.
The DC electric motor 31 corresponds to the change of the quenching condition including the liquid temperature of the cooling fluid, the size of the heating coil, the quenching characteristics of the workpiece, the quench hardening layer depth of the workpiece, and the like.
Is controlled so that the cooling rate of the work M can be controlled, and a quench hardened layer having a desired depth can be formed on the work M.

Further, below the heating coil 7, a quenching position switching mechanism 50 for holding the shaft portion 15 of the work holder 13 and moving it up and down is arranged. In this quenching position switching mechanism 50, as shown in FIGS. 1 and 3, an elevating rod 52 is movably supported by a bearing 51 arranged at the bottom of the cooling liquid tank 2 below the heating coil 7. A holding member 54 for holding a disk-shaped holding plate 53 provided on the shaft portion 15 of the work holder 13 is provided at the upper end of the elevating rod 52, and a roller 55 is rotatably provided at the lower end. There is.

The roller 55 is supported on a cam surface 57a of a cam member 57 which is rotatably supported by a cam support member 56 provided upright on the base frame 1. As the cam member 57 is rotated, the roller 55 moves up and down. The holding plate 5 in which the rod 52 is moved up and down corresponding to the shape of the cam surface 57a and is clamped by this.
5 is moved up and down, and the work holder 13 is moved up and down. Further, the elevating rod 52 is biased downward by a spring member 58 so that the work holder 13 is securely held. Therefore, the quenching position switching mechanism 50 can be used to quench the workpiece M by switching the quenching position in the vertical direction.

As shown in FIGS. 1 and 2, the work support base 8 is indexed and rotated so that the work holder 13 is sequentially moved from the first stage S1 to the eighth stage S8. Work attachment, quenching, cooling and work removal are performed. In the first stage S1, the workpiece holder 13 is in the raised position, the workpiece M is attached to the workpiece holder 13, and when the workpiece holder M is moved toward the second stage S2, the axis of the workpiece holder M moves. The part M is lowered along the inclined surface of the inclined track plate 19, and the work M is immersed in the cooling liquid W. Then the fifth
Induction hardening is performed by the heating coil 7 at the stage S5 (corresponding to the processing position immediately below the heating coil), and the work M is immersed in the cooling liquid W at the sixth and seventh stages S6, S7. After cooled, the work holder 1
3 is lifted by the inclined track plate 19, and the eighth stage S8
In, the work M is taken out.

The operation of the above-described submerged hardening apparatus will be described below. In the first stage S1, the workpiece holder 13 is in the raised position, and the workpiece M is fitted and attached to the workpiece holder 14 of the workpiece holder 13 at the raised position, and the workpiece is driven by the rotation drive of the index motor 11. As the holder 13 is moved to the second stage, the lower end of the shaft portion 15 of the workpiece holder 13 is moved along the inclined surface of the inclined track plate 19, and the workpiece holder 13 is moved.
Is gradually lowered, and the work M is immersed in the cooling liquid W.

Further, when the work support base 8 rotates and the work holder 13 reaches the fifth stage S5, the induction hardening apparatus 5 is lowered by the drive of the air cylinder 4, and the coil 7 is placed in the through hole a of the work M. Will be located in. At this position, a high-frequency current is supplied to the heating coil 7 and the work M
Induction hardening is applied to the surface of the through hole a. On this occasion,
The timing pulley 34 provided at the lower end of the shaft portion 15 of the work holder 13 is engaged with the double-sided synchro belt 36 of the work rotation drive mechanism 30, and the work holder 13 is driven at a constant speed by the rotation drive of the DC electric motor 31. Is rotated. Since the work M is rotated by the DC electric motor 31, the work M is induction hardened without causing uneven hardening.

At the same time, a centrifugal force acts on the cooling liquid W as the work holder 13 rotates, and the cooling liquid whose temperature has risen due to the heat of quenching around the through hole a of the work M is indicated by the arrow in FIG. The convection in the direction shown occurs, and the cooling liquid W in the upper part of the work M in which the liquid temperature is not relatively increased flows into the through hole a of the work M, and the drain hole formed in the peripheral wall 13a of the work holder 13. It comes to be discharged from the work holder 13 from 19. Since the convection flow velocity can be adjusted by controlling the rotation speed of the DC electric motor 31 by the rotation speed control device 40, the cooling speed of the work M can be controlled, so that the work M is quenched at a desired constant depth. A hardened layer can be formed, and quenching is performed so that the hardened work M has uniform physical properties.

The rotation speed control device 40 for the DC electric motor 31 will be described with reference to FIG. Work M
DC electric motor 31 for controlling the cooling rate of the work M in order to form the depth D of the quench hardened layer of
The parameters for setting the rotation speed are the heating coil size S, the hardenability U depending on the metal composition of the work material, and the liquid temperature T of the cooling liquid. From these parameters, the rotation speed N of the DC electric motor 31 is set by the following arithmetic expression. N = a × T + b × S + c × U + d × D (a> 0, b <
0, c <0, d <0) In the above equation, the coefficient a of the liquid temperature T of the cooling liquid, the coefficient b of the size S of the heating coil, the coefficient c of the hardenability U of the work, and the quenching depth D of the work Coefficients d, which are set based on a large number of test data.

The coefficient a of the liquid temperature T of the cooling liquid is set to a positive predetermined value, and the rotation speed N of the electric motor 31 is set to increase as the liquid temperature of the cooling liquid increases. There is. In induction hardening, the heating coil 7
And the work M are subjected to quenching with a predetermined range of space therebetween, so that the heating coil size S increases, that is, as the work size increases, the work M increases.
Of the heating coil size S, the coefficient b of the heating coil size S is set to a negative predetermined value because the peripheral speed increases and the thermal conductivity decreases, so the hardenability of the work M decreases. Is set so that the rotation speed N of the electric motor 31 becomes slower so that the cooling rate of the work becomes slower in accordance with the increase of the.

Further, the coefficient c of the hardenability U of the work is set to a predetermined negative value, and the cooling rate is lowered as the hardenability of the work increases (exhibits excellent hardenability). In addition, the rotation speed of the electric motor is set to be slow. Then, the coefficient d of the depth D of the quench hardened layer is set to a predetermined negative value, and the rotation of the electric motor 31 is reduced so that the cooling rate of the work becomes slower as the depth D of the quench hardened layer increases. The speed N is set to be slow.

The cooling liquid temperature T is input to the control box 43 by the liquid temperature sensor 41, and the heating coil size S, the hardenability U of the work and the depth D of the hardened layer are set.
Is input through the keyboard 42, each of these data is applied to the above-mentioned arithmetic expression to be calculated by the control box 43, and the motor drive circuit 44 is controlled from the control box 43 so as to obtain the obtained rotation speed N. A signal is sent to the motor drive circuit 44 based on this control signal.
The control current set in 1 is supplied to the DC electric motor 31, and the DC electric motor 31 is rotationally driven at the rotation speed N set by the arithmetic expression. In addition, instead of the method of setting the rotation speed of the DC electric motor 31 by the above-described arithmetic expression, a map made up of the parameters of the above-mentioned quenching condition is created,
The rotation speed of the electric motor 31 may be controlled based on this map.

Therefore, the rotation speed N of the electric motor is controlled in response to changes in quenching conditions such as the temperature of the cooling fluid, the size of the heating coil, the quenchability of the workpiece, the depth of the quench hardened layer of the workpiece, and the like. Since the cooling rate of the work M is controlled, in the induction hardening process performed by this submerged quenching apparatus, even if the hardening conditions are changed, a hardened layer is desired for the work M. Can be formed at a certain depth.

When the induction hardening process for the work M is completed, the induction hardening device 5 is moved up by the cylinder 4, and the coil 7 is moved up to the upper opening of the cooling liquid tank 2. On the other hand, the work holder 13 has a seventh stage S.
The work M is cooled in the cooling liquid W until the temperature reaches 7.
Then, in the eighth stage S8, the work holder 13
Is gradually raised along the inclined track plate 19, and the work M for which quenching has been completed is taken out. As described above, in this submerged quenching apparatus, the work M is continuously subjected to induction hardening, so that the workability is improved and the work M is processed.
Since the cooling rate can be controlled, it is possible to form a quench-hardened layer with a desired depth on the work.

Next, an in-liquid quenching apparatus of another embodiment will be described. This submerged quenching apparatus, as shown in FIGS. 6 to 9, is a work holder 1 of the submerged quenching apparatus of the above-described embodiment.
3 has substantially the same configuration except that the lifting mechanism of 3 and the work rotating mechanism 30 have different configurations, and the same parts are denoted by the same reference numerals and description thereof is omitted.

Work holder 13A of this submerged hardening apparatus
As shown in FIG. 8, the shaft portion 15 is rotatably supported by a bearing 63 in a bearing cylinder 62 that is vertically inserted in a cylinder 60 attached to the work support 8. . The bearing cylinder 62 is configured to be moved up and down by the air supplied to the upper and lower cylinder inner chambers 65 and 66 partitioned by the piston 64 that moves up and down in the cylinder 60. Air passages 67 and 68 are connected to the upper and lower cylinder chambers 65 and 66, respectively, and a rotary valve 69 for switching and controlling the supply of air is connected to the air passages 67 and 68. Therefore, as the work holder 13A that holds the work M is index-rotated by the index motor 11, the rotary valve 6 is rotated in response to the index rotation from the first stage to the eighth stage.
9 is sequentially switched, and the work holder 13A is moved up and down.

A spline portion 15a is formed at the lower end of the shaft portion 15 of the work holder 13, and the spline portion 15a is interlocked with the work rotation drive mechanism 30A to rotate the work holder 13A. Is configured. The work rotation drive mechanism 30A is rotatably supported by a bearing 70 provided at a bottom position of the cooling liquid tank 2 corresponding to a position below the fifth stage.
Is provided with a connecting portion 72 at the upper end thereof, and the shaft portion 1 of the work holder 13 is inserted into the spline hole 72a formed in the connecting portion 72.
5, the spline portion 15a is detachably inserted,
At the time of fitting, the work holder 13 and the work rotation shaft 71 are configured to be interlocked and connected.

A timing pulley 73 is provided at the lower end of the work rotating shaft 71. The timing pulley 73 is engaged with a double-sided synchro belt 76 wound around a drive pulley 74 and a driven pulley 75, and the lower end of the drive pulley 74 is engaged. The work holder 13 is rotationally driven by rotationally driving the DC electric motor 31 provided in the section. This submerged quenching apparatus is similar to the submerged quenching apparatus of the above-described embodiment in that the work holder 1
Since 3A is driven to rotate by the DC electric motor 31, uneven quenching does not occur. Further, by controlling the rotation speed of the DC electric motor 31 via the rotation speed control device, the cooling speed of the work M is controlled, and the quench hardening layer having a desired depth can be formed on the work M.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of an in-liquid quenching apparatus according to an embodiment.

2 is a plan view of the submerged quenching apparatus of FIG. 1. FIG.

FIG. 3 is a vertical sectional front view of a main part of the submerged quenching apparatus of FIG.

4 is a perspective view showing an outline of a work rotation drive mechanism of the submerged quenching apparatus of FIG. 1. FIG.

5 is a configuration diagram of a rotation speed control mechanism of the liquid quenching apparatus of FIG.

FIG. 6 is a partially longitudinal front view of a submerged quenching apparatus according to another embodiment.

FIG. 7 is a plan view of FIG.

8 is a vertical cross-sectional front view of a main part of the submerged quenching apparatus of FIG.

9 is a perspective view schematically showing a work rotation drive mechanism of the submerged quenching apparatus of FIG.

[Explanation of symbols]

 2 Coolant tank 7 Heating coil 8 Work support 13, 13A Work holder 31 DC electric motor 40 Rotation speed control mechanism M Work W Coolant

Claims (1)

[Claims] 1. A submerged quenching apparatus for quenching a work immersed in a cooling liquid with a heating coil, wherein the work support is disposed in a cooling liquid tank for storing the cooling liquid, and the work support is provided. A work holder that is rotatably pivoted to and holds a work; an electric motor that rotationally drives the work holder; and a rotation speed control unit that controls the rotation speed of the electric motor. Submerged quenching device.