KR102660325B1 - Yoke shaft induction heat treatment method - Google Patents

Abstract

The present invention relates to a yoke shaft induction heat treatment method. The yoke shaft induction heat treatment method according to the present invention includes a supply unit for supplying the yoke shaft, a heat treatment unit for induction heat treatment, a rust prevention treatment unit for rust prevention treatment, and a discharge unit for discharging the yoke shaft. and a transfer unit for transporting the yoke shaft, wherein the transfer unit includes a linear guide rail and a plurality of linear guide blocks that move horizontally on the linear guide rail, and the linear guide block includes the heat treatment unit and the rust prevention treatment unit. A first gripper that moves, a second gripper that moves the rust prevention treatment unit and the discharge unit, the first gripper and the second gripper simultaneously perform horizontal movement and lifting movement while maintaining the separation distance, and the supply unit , a first turntable including a plurality of first yoke shaft jigs and a plurality of first spindle jigs spaced apart along the circumference, and rotating at a predetermined angle; an input gripper disposed above the first turntable and horizontally and vertically moving in a section between the supply unit and the heat treatment unit; It includes a heat treatment unit, a second turntable including four second yoke shaft jigs and four second spindle jigs spaced apart along the circumference, and rotating at a predetermined angle; an insertion confirmation sensor disposed on the upper side of the second turntable and detecting the presence or absence of the yoke shaft; A heat treatment jig disposed above the second turntable and moving up and down; and a heat treatment power unit for supplying power to the heat treatment jig. The heat treatment jig includes a movable induction coil through which the yoke shaft is inserted to heat the yoke shaft at high frequency; and a plurality of coolant nozzles through which coolant is discharged. It includes a heat treatment power unit, a CT BOX capable of transmitting power to the induction coil; A yoke shaft high frequency heat treatment system including a high frequency oscillator capable of supplying power to the CT BOX, comprising: supplying the yoke shaft; A heat treatment step of performing heat treatment on the yoke shaft; A rust prevention treatment step of performing a rust prevention treatment on the yoke shaft for which the heat treatment step has been completed; and a discharging step of discharging the yoke shaft on which the rust prevention treatment step has been completed. It is characterized by including.

Description

Yoke shaft induction heat treatment method

The present invention relates to a high-frequency heat treatment system for a yoke shaft. More specifically, it consists of a full-line automated equipment system to perform the yoke shaft high-frequency heat treatment work process to increase the effective hardened layer depth of the yoke shaft to satisfy the required hardened layer hardness. In addition, it is about an economical yoke shaft high-frequency heat treatment system that reduces management costs.

In general, the yoke shaft is a component of the propeller shaft that transmits power generated from a car engine through a transmission and rotational force to the rear differential.

This yoke shaft is made of casting, so it is weak in brittleness. It is a part that requires high torsional strength and durability when a rotational force is transmitted, and high-frequency heat treatment is essential to increase hardness to satisfy the torsional strength against impact when a rotational force is transmitted.

Meanwhile, various high-frequency heat treatment devices have been used for high-frequency heat treatment of the yoke shaft. However, since the high-frequency heat treatment process is performed manually, productivity is low, labor costs are high, and the defect rate is increased because a separate comprehensive inspection process is not provided. There is.

In other words, looking at the heat treatment process of the conventional yoke shaft, the yoke shaft is manually inputted in an elevator-type high-frequency heat treater, and after the high-frequency heat treatment process is completed, the worker discharges it manually and performs a rust prevention process. This process requires a lot of travel time. Not only is there a problem of low productivity, but the precision of heat-treated parts varies depending on the worker's skill or working time, resulting in quality deviations. Defects such as process omissions, cracks, poor effective hardened layer depth, and heat treatment pattern mismatch occur frequently. It happens.

Patent Document 1 was proposed to solve this problem, but there is a problem in that the worker has to manually place the shaft on the pallet, which reduces work efficiency and productivity and increases labor costs.

Therefore, by improving the automated high-frequency heat treatment process to an automated high-frequency heat treatment process, production volume per hour is increased and process omissions, heat treatment section inconsistencies, local melting, cracks, hardened layer structure defects, hardened layer hardness exceeding and falling short, and effective hardened layer depth exceeded. There is a need for the development of a yoke shaft high-frequency heat treatment method that not only prevents defects caused by operator errors such as under-skilling, but also reduces labor costs by reducing the number of workers.

[Patent Document] KR 10-2065757 (registration date: January 7, 2020)

In order to solve the above problems, the present invention implements an automated high-frequency heat treatment method in which the heat treatment process is performed including the supply step, heat treatment step, rust prevention treatment step, and discharge step, thereby increasing production per hour and reducing the risk of operator error. The purpose is to provide a yoke shaft high-frequency heat treatment method that not only prevents defects but also reduces labor costs by reducing the number of workers.

It includes a supply part for supplying the yoke shaft, a heat treatment part for high-frequency heat treatment, a rust prevention treatment part for rust prevention treatment, a discharge part for discharging the yoke shaft, and a transfer part for transferring the yoke shaft, and the transfer part includes a linear guide rail and the linear It includes a plurality of linear guide blocks that move horizontally on a guide rail, wherein the linear guide blocks include a first gripper that moves the heat treatment unit and the rust prevention treatment unit, a second gripper that moves the rust prevention treatment unit and the discharge unit, and the first gripper that moves the rust prevention treatment unit and the discharge unit. The first gripper and the second gripper simultaneously perform horizontal movement and lifting movement while maintaining the separation distance, and the supply unit includes a plurality of first yoke shaft jigs and a plurality of first spindle jigs spaced apart along the circumference. A first turntable comprising: a first turntable rotating at a predetermined angle; an input gripper disposed above the first turntable and horizontally and vertically moving in a section between the supply unit and the heat treatment unit; It includes a heat treatment unit, a second turntable including four second yoke shaft jigs and four second spindle jigs spaced apart along the circumference, and rotating at a predetermined angle; an insertion confirmation sensor disposed on the upper side of the second turntable and detecting the presence or absence of the yoke shaft; A heat treatment jig disposed above the second turntable and moving up and down; and a heat treatment power unit for supplying power to the heat treatment jig. The heat treatment jig includes a movable induction coil through which the yoke shaft is inserted to heat the yoke shaft at high frequency; and a plurality of coolant nozzles through which coolant is discharged. It includes a heat treatment power unit, a CT BOX capable of transmitting power to the induction coil; A yoke shaft high frequency heat treatment system including a high frequency oscillator capable of supplying power to the CT BOX, comprising: supplying the yoke shaft; A heat treatment step of performing heat treatment on the yoke shaft; A rust prevention treatment step of performing a rust prevention treatment on the yoke shaft for which the heat treatment step has been completed; and a discharging step of discharging the yoke shaft on which the rust prevention treatment step has been completed. It is characterized by including.

In addition, the supply step according to the present invention includes a first turntable rotation process in which the first turntable of the supply unit rotates to rotate the first yoke shaft jig to a position below the insertion gripper; and a first turntable transfer process of transferring the yoke shaft to a second turntable using the insertion gripper; The heat treatment step includes a second turntable primary rotation process in which the second turntable rotates to rotate the second yoke shaft jig downward to the insertion gripper; a second turntable transfer process of transferring the yoke shaft to the second yoke shaft jig using the insertion gripper; A second turntable secondary rotation process in which the second turntable rotates to rotate the second yoke shaft jig downward to the heat treatment jig; A heat treatment process in which the heat treatment jig performs heat treatment of the yoke shaft; and a second turntable secondary rotation process in which the second turntable rotates to transfer the yoke shaft to a heat treatment jig to a lower position of the first gripper. It is characterized by including.

In addition, in the heat treatment process according to the present invention, the high frequency oscillation capacity of the high frequency oscillator is 150 kW, the frequency is 10 kHz, the output is 8.0, the lowering distance of the induction coil is 258 mm, and the lowering speed of the induction coil is 40 mm/sec. , the rising delay time of the induction coil is 2.0 sec, the rising speed of the induction coil is 12 mm/sec, and the cooling time is 35 sec, and high frequency heat treatment conditions are provided.

According to the yoke shaft high-frequency heat treatment method according to the present invention as described above, by implementing an automated high-frequency heat treatment method in which the heat treatment process is performed including the supply step, heat treatment step, rust prevention treatment step, and discharge step, the production per hour is increased and the worker's safety is increased. It not only prevents defects caused by mistakes, but also reduces labor costs by reducing the number of workers.

In addition, by increasing the effective hardened layer depth after heat treatment of the yoke shaft, the hardened layer hardness can be improved compared to the prior art.

Figure 1 is a block diagram showing the overall configuration of the yoke shaft induction heat treatment method according to the present invention.
Figure 2 is a block diagram showing the configuration of the supply step according to the present invention.
Figure 3 is a block diagram showing the configuration of the heat treatment step according to the present invention.
Figure 4 is a block diagram showing the configuration of the rust prevention treatment step according to the present invention.
Figure 5 is a block diagram showing the configuration of the discharge step according to the present invention.
Figure 6 is a plan view showing the overall configuration of the yoke shaft high-frequency heat treatment system according to the present invention.
Figure 7 is a right side view showing the overall configuration of the yoke shaft high-frequency heat treatment system according to the present invention.
Figure 8 is a detailed view showing the rotating positions of the first and second turntables according to the present invention.
Figure 9 is a detailed view of the induction coil of the heat treatment jig according to the present invention.
Figure 10 is a detailed view of the rust prevention treatment unit according to the present invention.
Figure 11 is a detailed view of the transfer unit according to the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. First of all, it should be noted that the same components or parts in the drawings are given the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the gist of the present invention.

As shown in FIGS. 6 and 7, the yoke shaft high-frequency heat treatment system 1 according to the present invention includes a supply unit 100, a heat treatment unit 200, a rust prevention treatment unit 400, a discharge unit 500, and a transfer unit 600. , may include a control unit 700.

Figure 8 is a detailed view showing the rotating positions of the first turntable 110 and the second turntable 210 according to the present invention.

The supply unit 100 of the present invention includes a first turntable 110 that includes a plurality of first yoke shaft jigs 111 and a first spindle jig 112 spaced apart along the circumference and rotates intermittently at a certain angle. It may include an insertion gripper 115 that is disposed on the upper side of the first turntable 110 and moves horizontally and vertically to transfer the yoke shaft 10.

The first turntable 110 is divided on the circumference in the order of the first yoke shaft jig 111 and then the first spindle jig 112, so that the first yoke shaft jig 111 includes the first yoke shaft 10. The spindle jig 112 may be configured to mount the spindle 15.

At this time, mounting of the yoke shaft 10 or spindle 15 may be done manually.

Therefore, the first turntable 110 may also be capable of mounting a spindle 15 of a similar shape to the yoke shaft 10.

Specifically, the first turntable 110 is divided into four positions and is provided with a first yoke shaft jig 111 and a first spindle jig 112 at each of the first, second, third and fourth positions. can do.

Accordingly, when the yoke shaft 10 of the first turntable 210 is mounted on the first yoke shaft jig 111, it can be rotated counterclockwise and transferred to a lower position of the insertion gripper 115.

At this time, when the spindle 15 is mounted on the first spindle jig 112, it can be rotated 90° counterclockwise and transferred to the lower position of the input gripper 115.

In addition, the first spindle jig 112 can be rotated 90° counterclockwise when the spindle 15 is mounted and transferred to a position below the input gripper 115.

Here, the first turntable 110 may include a rotating device (not shown) at the bottom that rotates the first turntable 110, and the rotating device may be any known device without limitation.

The heat treatment part is divided into 8 parts along the circumference and includes 4 second yoke shaft jigs 211 and 4 second spindle jigs 212, and the fifth position of the supply part, whether to input or not, is determined using an index divided into four parts. It may include a second turntable 210 that can be divided into a sixth position for checking, a seventh position for high-frequency heat treatment, and an eighth position for discharge, and can be rotated counterclockwise by exactly 90° and then stopped.

At this time, the second turntable 210 may include a rotating device (not shown) at the bottom, and any known rotating device can be applied without limitation.

In addition, it is configured to fix and rotate the inserted yoke shaft 10 or the spindle 15 for uniform heating during high-frequency heat treatment of the yoke shaft 10 or the spindle 15, and the eccentricity during rotation is It may be desirable to process it precisely to prevent it from occurring.

At this time, if the second yoke shaft jig 211 or the second spindle jig 212 is processed without precision, deformation is likely to occur during heat treatment and the yoke shaft 10 or the spindle 15 may be damaged locally due to coil contact. Many melting defects occur.

Here, the second yoke shaft jig 211 or the second spindle jig 212 may include a rotating device (not shown) at the bottom, and the rotating device can be any known device without limitation. there is.

Here, an insertion confirmation sensor 215 may be included, which is disposed on the upper side of the second turntable 210 and checks whether the yoke shaft 10 or the spindle 15 is inserted.

In addition, it may include a heat treatment jig 220 that is disposed on the upper side of the second turntable 210 and moves up and down to heat treat the yoke shaft 10 or the spindle 15.

At this time, the yoke shaft 10 delivered from the insertion gripper 115 can be mounted on the second spindle jig 212 when the spindle 15 is delivered to the second yoke shaft jig 211.

At this time, when the yoke shaft 10 is mounted on the second yoke shaft jig 211 of the second turntable 210, it can be rotated 90° counterclockwise and transferred to the lower position of the input gripper 115. there is.

As shown in FIG. 7, the heat treatment jig 220 according to the present invention is disposed on the upper side of the second turntable 210 and moves the yoke shaft ( 10) is placed, it descends to perform a high-frequency heat treatment process on the yoke shaft.

In addition, the heat treatment jig 220 approaches the yoke shaft 10 in a lifting manner to perform high-frequency heating of the yoke shaft 10 and at the same time sprays coolant to perform cooling treatment on the inner surface of the yoke shaft 10. Allows heating and cooling to be performed simultaneously.

Therefore, it is possible to design the heat treatment jig 220 of the yoke shaft 10 that can prevent cracks with the above-described configuration.

Additionally, the heat treatment jig 220 may include an induction coil 221, a coolant nozzle 222, and a heat treatment power unit 300.

Figure 9 is a detailed view of the induction coil 221 of the heat treatment jig 220 according to the present invention.

The induction coil 221 may be movable by being inserted through the yoke shaft 10 to heat the yoke shaft 10 at high frequency.

Specifically, the induction coil 221 is the most important core component of high-frequency heat treatment, and its curing pattern, effective hardening layer depth, and surface hardness may vary depending on its shape, and the yoke shaft 10 is uniformly heated or It can be configured to maintain the coolant spray angle, coolant flow, and appropriate distance from heat treated parts to ensure cooling.

Therefore, it may be desirable that the induction coil 221 is composed of a single coil and is movable so that changes in inductance (magnetic induction) can be minimized and cooling delay time can be adjusted.

At this time, the coolant nozzle 222 may be composed of multiple coolant nozzles through which coolant is discharged.

Here, the heat treatment power unit 300 may include a CT BOX 310 capable of supplying power required for the induction coil 221 and a high frequency oscillator 312 for supplying power to the CT BOX 310. there is.

More specifically, the CT BOX (310) further includes a CT BOX Adjuster (311) so that the heat treatment jig (220) can be moved up and down on the yoke shaft (10). At this time, the CT BOX Adjuster (311) ) may include an elevating means such as a lift and a forward/backward moving means such as an LM guide to elevate the CT BOX 310 simultaneously with the heat treatment jig 220.

As shown in FIG. 10, the rust prevention treatment unit 400 of the present invention may be provided to prevent rust treatment of the yoke shaft 10 by adding rust prevention oil to the yoke shaft 10.

Specifically, the rust prevention treatment unit 400 is provided with a rust prevention oil tank 410 in the shape of a box with an open top and a certain space in which rust prevention oil can be stored, and the yoke shaft 10 is provided inside the rust prevention oil tank 410. It may be configured to include a fixed jig 420 and a hydraulic vertical transfer piston 430 that raises and lowers the fixed jig 420.

More specifically, the rust prevention treatment unit 400 is formed when the yoke shaft 10 that has completed the high-frequency heat treatment process is taken out from the heat treatment unit 200 by a first gripper 621, which will be described later, and transferred to the fixing jig 420. The fixing jig 420 is lowered by the downward movement of the vertical transfer piston 430 so that the yoke shaft 10 can be immersed in the anti-rust oil and treated for rust prevention.

The discharge unit 500 of the present invention is provided to discharge the yoke shaft 10.

Specifically, the discharge unit 500 may be composed of a longitudinal conveyor belt that allows the yoke shaft 10, which has passed through the heat treatment unit 200 and the rust prevention treatment unit 400, to be discharged to the outside.

At this time, as an example, the discharge unit 500 may be configured to prevent the yoke shaft 10 from falling by installing V-shaped stoppers (not shown) at both ends.

Here, the discharge unit 500 may be configured to stop operating when the yoke shaft 10 moves for a certain period.

Additionally, the discharge unit 500 may be configured to adjust transfer speed and height.

Figure 11 is a detailed view of the transfer unit 600 according to the present invention.

The transfer unit 600 of the present invention is provided to transfer the yoke shaft 10 to the heat treatment unit 200, the rust prevention treatment unit 400, and the discharge unit 500 in stages.

Specifically, the transfer unit 600 is a gantry type consisting of two grippers and a transfer piston capable of simultaneously moving the grippers to transfer the yoke shaft 10 to each stage, and charges the yoke shaft 10, It may be composed of a robot system for transport and retrieval.

Here, the transfer unit 600 may include a longitudinal linear guide rail 610 and a plurality of linear guide blocks 620 moving on the linear guide rail 610.

At this time, the linear guide block 620 may be configured to repeatedly horizontally move a certain section on the linear guide rail 610 and move up and down for loading and unloading the yoke shaft 10.

Additionally, the linear guide block 620 may include a first gripper 621 and a second gripper 622.

The first gripper 621 is provided to horizontally move the section between the heat treatment unit 200 and the rust prevention treatment unit 400.

Specifically, the first gripper 621 moves horizontally to the upper side of the first position of the second turntable 210 of the heat treatment unit 200 and then descends to the second yoke shaft jig 211 at the first position. The yoke shaft 10 is charged and raised, moved horizontally from the raised position to the upper side of the rust prevention treatment unit 400, and then lowered to charge the yoke shaft 10 into the fixing jig 420 of the rust prevention treatment unit 400. The yoke shaft 10 is configured to be disposed on the rust prevention treatment unit 400.

The second gripper 622 is provided to horizontally move the section between the rust prevention treatment unit 400 and the discharge unit 500.

At this time, the second gripper 622 is provided to horizontally move the section between the rust prevention treatment unit 400 and the discharge unit 500.

Specifically, the second gripper 622 descends from the rust prevention treatment unit 400, takes out the yoke shaft 10 disposed on the fixing jig 420 of the rust prevention treatment unit 400, then rises and discharges the yoke shaft 10 from the raised position. It is configured to move horizontally to the upper side of the unit 500 and then descend to insert the yoke shaft 10 into the discharge unit 500 so that the yoke shaft 10 can be placed in the discharge unit 500.

Here, the first gripper 621 and the second gripper 622 are arranged to be spaced apart at a predetermined distance, move horizontally left and right at the same time while maintaining the separation distance, and load and extract the yoke shaft 10 at the moved distance. It is structured so that it can be done.

The control unit 700 of the present invention is provided to control the operation of the supply unit 100, heat treatment unit 200, heat treatment power unit 300, rust prevention treatment unit 400, discharge unit 500, and transfer unit 600. .

Specifically, the control unit 700 controls each configuration so that all processes of insertion, transfer, induction heat treatment, and rust prevention treatment of the yoke shaft 10 can be performed step by step when working conditions are input, and the supply unit 100 ) is controlled so that the yoke shaft 10 supplied to the machine can be discharged after induction heat treatment and anti-rust treatment.

In addition, when the yoke shaft 10 is placed in the fifth position of the second turntable 210, the second turntable 210 is rotated 90° and the yoke shaft is placed in the sixth position, and at this time, the insertion confirmation is performed. After the sensor 215 descends and detects the presence or absence of the yoke shaft 10, the first turntable 210 rotates 90° so that the yoke shaft is placed in the 7th position and the heat treatment jig 220 of the heat treatment unit 200 ) is controlled to descend and perform a high-frequency heat treatment process on the transported yoke shaft.

At this time, when the operation of the heat treatment jig 220 is completed, the second turntable 210 rotates 90°, and the yoke shaft 10 for which induction heat treatment has been completed is transferred to the 8th position of the second turntable 210 for induction heat treatment. The first gripper 621 descends and takes out the completed yoke shaft 10, then rises and moves horizontally to the upper side of the rust prevention treatment unit 400, and the horizontally moved first gripper 621 descends to hold the yoke shaft ( 10) is controlled to be inserted into the fixing jig 420 of the rust prevention device.

In addition, when the yoke shaft 10 is inserted into the fixing jig 420 of the rust prevention treatment unit 400, the fixing jig 420 is lowered and the yoke shaft 10 is immersed in the rust prevention oil to perform rust prevention treatment and then rise. do.

In addition, when the yoke shaft 10 that has completed rust prevention treatment rises to its original position, the second gripper 622 descends, takes out the yoke shaft 10 that has completed rust prevention, rises, and then moves horizontally to the upper side of the discharge unit 500. Then, it is lowered and controlled so that the yoke shaft on which all processes have been completed is transferred to the discharge unit 500 for collection.

Hereinafter, the yoke shaft induction heat treatment method according to the present invention will be described.

Figure 1 is a block diagram showing the overall configuration of the yoke shaft induction heat treatment method according to the present invention.

As shown in FIG. 1, the yoke shaft heat treatment method according to the present invention may include a supply step (S100), a heat treatment step (S200), a rust prevention treatment step (S300), and a discharge step (S400).

Figure 2 is a block diagram showing the configuration of the supply step (S100) according to the present invention.

The supply step (S100) according to the present invention may be a step of supplying the yoke shaft 10 as shown in FIG. 2.

Specifically, in the supply step (S100), the yoke shaft 10 is inserted into the first yoke shaft jig 111 of the first turntable 110 by the operator and the first turntable 110 is rotated. This may be a step in which the gripper 115 descends and transfers the yoke shaft 10.

Accordingly, the supply step (S100) may include a first turntable rotation process (S110), a first turntable primary rotation process (S110), and a first turntable transfer process (S120).

The first turntable rotation process (S110) may be a process in which the first turntable 110 rotates at a certain angle.

Specifically, the first turntable rotation process (S110) is performed after the yoke shaft 10 is mounted on the first yoke shaft jig 111 at the first position of the first turntable 110. ) may be a process in which the first turntable 110 rotates to the second position and the yoke shaft 10 rotates to a position below the insertion gripper 115.

The first turntable transfer process (S120) may be a process in which the insertion gripper 115 transfers the yoke shaft 10 from the first turntable 110 to the second turntable 210.

Specifically, in the first turntable transfer process (S120), the input gripper 115 descends from the upper side of the second position to extract the yoke shaft 10 and then moves to the upper side of the fifth position of the second turntable 210. This may be a process of mounting the yoke shaft 10 at the fifth position of the second turntable 210 after horizontal movement.

Figure 3 is a block diagram showing the configuration of the heat treatment step according to the present invention.

The heat treatment step (S200) according to the present invention may be a step of performing high-frequency heat treatment of the yoke shaft 10 as shown in FIG. 3.

Therefore, the heat treatment step (S200) includes the second turntable first rotation process (S210), the second turntable transfer process (S220), the second turntable second rotation process (S230), the heat treatment process (S240), and the second turntable 3. It may include a second rotation process (S250).

The second turntable first rotation process (S210) may be a process in which the second turntable 210 is rotated at a certain angle so that the second yoke shaft jig 211 rotates below the input gripper 115.

Specifically, the second turntable first rotation process (S320) is a process in which the second turntable 310 rotates to the fifth position, and the second turntable 210 rotates to the second yoke shaft jig 211. ) may be a process of rotating the input gripper 115 downward.

The second turntable transfer process (S220) may be a process in which the input gripper 115 transfers the yoke shaft 10 to the second yoke shaft jig 211.

Specifically, the second turntable transfer process (S220) may be a process in which the insertion gripper 115 transfers the yoke shaft 10 from the first turntable 110 to the second turntable 210.

Specifically, in the second turntable transfer process (S220), the input gripper 115 descends from the upper side of the second position of the first turntable 110 to extract the yoke shaft 10, and then the second turntable 210 This may be a process of mounting the yoke shaft 10 at the fifth position of the second turntable 210 after moving it horizontally to the top of the fifth position.

The second turntable secondary rotation process (S230) may be a process of rotating the second turntable 210 at a certain angle.

Specifically, the second turntable first rotation process (S320) is a process in which the second turntable 210 rotates after the yoke shaft 10 is placed at the fifth position of the second turntable 310. This may be a process in which the second turntable 210 rotates 90° counterclockwise to place the yoke shaft 10 in a sixth position where high-frequency heat treatment is possible.

The heat treatment process (S240) may be a process in which the heat treatment jig 220 performs high-frequency heat treatment of the yoke shaft 10.

Specifically, the heat treatment process (S240) may be a process in which, when the yoke shaft 10 is placed in the sixth position, the heat treatment jig 220 disposed on the upper side is lowered to perform high-frequency heat treatment on the yoke shaft 10. there is.

Therefore, in the heat treatment process (S230), the heat treatment jig 220 is lowered so that the induction coil 221 heats the yoke shaft 10 at high frequency and discharges coolant from the second coolant nozzle 222, This may be a process in which high-frequency heating and cooling are simultaneously performed so that heating and cooling of the yoke shaft 10 can be performed simultaneously.

The second turntable 3rd rotation process (S250) may be a process in which the second turntable 310 rotates at a certain angle after the heat treatment process (S230).

Specifically, the second turntable third rotation process (S250) is arranged at the sixth position of the second turntable 210 and the yoke shaft 10 that has completed the heat treatment process (S230) is performed on the second turntable (210). In the process of transferring to the seventh position, the second turntable 210 may be rotated 90° counterclockwise to place the yoke shaft 10 in the seventh position.

Figure 4 is a block diagram showing the configuration of the rust prevention treatment step according to the present invention.

The rust prevention treatment step (S300) according to the present invention may be a step of performing rust prevention treatment on the yoke shaft 10 on which induction heat treatment has been completed, as shown in FIG. 4.

Specifically, the rust prevention treatment step (S300) involves transferring the yoke shaft disposed on the second turntable 210 by the first gripper 621 to the rust prevention treatment unit 400, and then transferring the yoke shaft placed on the second turntable 210 to the rust prevention treatment unit 400. This may be a step of performing rust prevention treatment on the yoke shaft.

Therefore, the rust prevention treatment step (S300) may include a first gripper transfer process (S310) and a rust prevention treatment process (S320).

The first gripper transfer process (S310) may be a process in which the first gripper 621 of the transfer unit 600 transfers the yoke shaft from the second turntable 210 to the rust prevention treatment unit 400.

Specifically, in the first gripper transfer process (S310), the first gripper 621 descends from the upper side of the 7th position and takes out the yoke shaft 10, and then the upper side of the fixing jig 320 of the rust prevention treatment unit 300. This may be a process of mounting the yoke shaft 10 on the fixing jig 420 after horizontal movement.

The rust prevention treatment process (S320) may be a process of treating the yoke shaft 10 disposed on the fixing jig 320 to prevent rust.

Specifically, in the rust prevention treatment process (S320), the fixing jig 320 on which the yoke shaft is disposed is lowered by the vertical transfer piston 330 to immerse the yoke shaft 10 in the rust prevention liquid, and the rust prevention treatment is performed. When is completed, the fixing jig 320 is raised by the transfer piston 330, which may be a process of returning the yoke shaft 10 to its original position.

Figure 5 is a block diagram showing the configuration of the discharge step according to the present invention.

The discharging step (S500) according to the present invention may be a step of discharging the yoke shaft 10 on which the rust prevention treatment step (S400) has been completed, as shown in FIG. 5.

Therefore, the discharge step (S400) may include a second gripper transfer process (S410) and a discharge unit driving process (S420).

Specifically, the second gripper transfer process (S410) may be a transfer process in which the second gripper 622 moves horizontally to the upper side of the fixing jig 320 and then transfers the yoke shaft 10 to the discharge unit 500. there is.

The discharge unit driving process (S420) may be a process of discharging the yoke shaft 10 from the discharge unit 500.

The material of the yoke shaft 10 to be subjected to induction heat treatment in the present invention is SAE J403 grade 1045, and the hardened portion structure may be composed of a fine martensite structure.

The general quenching temperature is AC3+20∼30℃, and since the heating rate is fast, the high-frequency heat treatment heating temperature must be selected higher than that of general heat treatment, taking this into account. Since the yoke shaft 10 is a QT-treated material, it is selected at 880℃. can be

Accordingly, the high-frequency oscillation capacity and frequency required for induction heat treatment of the yoke shaft 10 can be optimized.

1) Heated weight calculation

[Equation 1]

2) Calculate power consumption

[Equation 2]

Therefore, considering heat loss, conductivity, etc., the actual power required is about 5 times the theoretical value, so a capacity of 24.43 × 5 = 122.15 is appropriate, and the high-frequency output can be determined to be 150 kW.

3) Frequency calculation

[Equation 3]

Therefore, the effective hardened layer depth actually goes deeper than the theoretical value and can be adjusted by heating time, so it can be determined at 10KHz.

Meanwhile, in order to obtain a uniform martensite structure during high-frequency heat treatment, the critical zone (high-frequency heat treatment temperature ~ Nose point of the S curve) must be cooled faster than the upper critical cooling rate, and the critical zone (M _s ~ M _f ) must prevent cracking due to transformation stress. To do this, it must be cooled slowly.

In addition, according to research reports, it is reported that cracking can be prevented when the coolant PVA (polyvinyl alcohol) concentration is 8 to 12%. By analyzing preliminary experiment data and empirical data, the cooling control condition setting values were derived as shown in Table 1. can do.

small water concentration 10±2% small water pressure 0.2±0.01MPa Soaking water temperature 25±5℃ Cooling delay time 0 cooling time 35.0±0.05Sec

After setting the high-frequency oscillator power, frequency, and output settings and cooling control condition settings previously developed, high-frequency heat treatment work process control values are developed through several experiments. Table 2 shows the yoke shaft developed in this project ( 10) shows the induction heat treatment process control settings.

Setting items Setting value note Induction coil descent distance 258.0±0.05mm Induction coil descending speed 40.0±0.05mm/Sec Rise delay time 2.0±0.5Sec Start heating

In addition, the standard operating conditions settings for induction heat treatment of the yoke shaft 10 are shown in Table 3.

Setting items Setting value Setting items Setting value high frequency power 150kW Soaking water temperature 25℃ high frequency frequency 10kHz Small water pressure (kgf/㎠) 0.2±0.01MPa Print 8.0 Cooling delay time 0.Sec small water concentration 10% cooling time 35.0Sec Induction coil descent distance 258.0mm Induction coil descent distance 40.0mm/Sec Induction coil rise delay 2Sec

According to the yoke shaft high-frequency heat treatment system 1 according to the present invention as described above, the yoke shaft 10 is gradually transferred to the supply unit 100, heat treatment unit 200, rust prevention treatment unit 400, and discharge unit 500. It is composed of an automated high-frequency heat treatment system including a transfer unit 600, which not only increases production per hour and prevents defects due to operator error, but also reduces labor costs by reducing the number of workers. In addition, the yoke shaft After the heat treatment process, the degree and hardness can be increased and the wear resistance can be improved compared to before.

The terms and words used in the specification and claims described above should not be construed as limited to their usual or dictionary meanings, and the inventor has appropriately used the concept of terms to explain his invention in the best way. It must be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined clearly.

Therefore, the configuration shown in the drawings and examples described in this specification is only one of the most preferred embodiments of the present invention, and does not represent the entire technical idea of the present invention, so they cannot be replaced at the time of filing the present application. It should be understood that various equivalents and variations may exist.

1: Yoke shaft high frequency heat treatment system
10: Yoke shaft 15: Spindle
100: supply unit 110: first turntable
111: 1st yoke shaft jig 112: 1st spindle jig
115: Insertion gripper
200: heat treatment unit 210: second turntable
211: 2nd yoke shaft jig 212: 2nd spindle jig
215: Input confirmation sensor
220: Heat treatment jig 221: Induction coil
222: Coolant nozzle
300: Heat treatment power unit 310: CT BOX
311: CT BOX Adjuster 312: High frequency oscillator
400: Rust prevention treatment unit 410: Rust prevention oil tank
420: Fixing jig 430: Up and down transfer piston
500: discharge unit 600: transfer unit
610: Linear guide rail 620: Linear guide block
621: first gripper 622: second gripper
700: Control unit
S100: Supply stage S110: First turntable rotation process
S120: 1st turntable transfer process
S200: Heat treatment step S210: 2nd turntable 1st rotation process
S220: Second turntable transfer process S230: Second turntable second rotation process
S240: Heat treatment process S250: 2nd turntable 3rd rotation process
S300: Rust prevention treatment step S310: First gripper transfer process
S320: Rust prevention treatment process
S400: Discharge step S410: Second gripper transfer process
S420: Discharge drive process

Claims (4)

It includes a supply part for supplying the yoke shaft, a heat treatment part for high-frequency heat treatment, a rust prevention treatment part for rust prevention treatment, a discharge part for discharging the yoke shaft, and a transfer part for transferring the yoke shaft, and the transfer part includes a linear guide rail and the linear It includes a plurality of linear guide blocks that move horizontally on a guide rail, wherein the linear guide blocks include a first gripper that moves the heat treatment unit and the rust prevention treatment unit, a second gripper that moves the rust prevention treatment unit and the discharge unit, and the first gripper that moves the rust prevention treatment unit and the discharge unit. The first gripper and the second gripper simultaneously perform horizontal movement and lifting movement while maintaining the separation distance, and the supply unit includes a plurality of first yoke shaft jigs and a plurality of first spindle jigs spaced apart along the circumference. A first turntable comprising: a first turntable rotating at a predetermined angle; an input gripper disposed above the first turntable and horizontally and vertically moving in a section between the supply unit and the heat treatment unit; It includes a heat treatment unit, a second turntable including four second yoke shaft jigs and four second spindle jigs spaced apart along the circumference, and rotating at a predetermined angle; an insertion confirmation sensor disposed on the upper side of the second turntable and detecting the presence or absence of the yoke shaft; A heat treatment jig disposed above the second turntable and moving up and down; and a heat treatment power unit for supplying power to the heat treatment jig. It includes a heat treatment jig, a movable induction coil composed of a single winding through which the yoke shaft is inserted to heat the yoke shaft at high frequency; and a plurality of coolant nozzles through which coolant is discharged. It includes a heat treatment power unit, a CT BOX capable of transmitting power to the induction coil; and a yoke shaft high-frequency heat treatment system including a high-frequency oscillator capable of supplying power to the CT BOX,
A supply step of supplying the yoke shaft;
A heat treatment step of performing heat treatment on the yoke shaft;
A rust prevention treatment step of performing a rust prevention treatment on the yoke shaft for which the heat treatment step has been completed; and
A discharge step of discharging the yoke shaft on which the rust prevention treatment step has been completed;
Including,
The supply stage is,
A first turntable rotation process in which the first turntable of the supply unit rotates to rotate the first yoke shaft jig to a position below the insertion gripper; and
A first turntable transfer process of transferring the yoke shaft to a second turntable using the insertion gripper;
Including,
The heat treatment step is,
A second turntable primary rotation process in which the second turntable rotates to rotate the second yoke shaft jig below the insertion gripper;
a second turntable transfer process of transferring the yoke shaft to the second yoke shaft jig using the insertion gripper;
a second turntable secondary rotation process in which the second turntable rotates to rotate the second yoke shaft jig downward to the heat treatment jig;
A heat treatment process in which the induction coil performs high-frequency heating and the plurality of coolant nozzles spray coolant to simultaneously heat and cool the inner surface of the yoke shaft while the heat treatment jig performs heat treatment of the yoke shaft; and
a second turntable third rotation process in which the second turntable rotates to transfer the yoke shaft to a lower position of the first gripper; A high-frequency heat treatment method for a yoke shaft, comprising: delete delete According to clause 1,
In the heat treatment process,
The high-frequency oscillator has a high-frequency oscillation capacity of 150 kW, a frequency of 10 kHz, and an output of 8.0,
The lowering distance of the induction coil is 258mm, the lowering speed of the induction coil is 40mm/sec, the rising delay time of the induction coil is 2.0sec, the rising speed of the induction coil is 12mm/sec, and the cooling time is 35sec, providing high frequency heat treatment conditions. A high-frequency heat treatment method for a yoke shaft, characterized in that.

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