JP7829907B2 - High-frequency induction hardening system - Google Patents

Description

This disclosure relates to a high-frequency induction hardening system for hardening steel machine parts and forged products, such as various machine parts and automatic components, using a water-soluble hardening agent.

Generally, to prevent distortion of the workpiece during quenching, when quenching forged products, it is known that cooling water, which is a solution of water containing 5-10% of a water-soluble quenching agent (water-soluble organic solute) as a solute, is sprayed onto the workpiece while maintaining the liquid temperature at room temperature.
However, even when using cooling water with added water-soluble quenching agents, quench cracking can still occur, even if the quality and performance are good.
The reasons for this are: (1) When water comes into contact with a metal at a high temperature, a large amount of latent heat of vaporization is rapidly removed during the evaporation of the water, causing it to cool too quickly; (2) Also, because the state of water on the metal surface differs from place to place, such as bubbles or steam, severe heat unevenness occurs; (3) Furthermore, forged products in particular accumulate a large amount of stress internally, and are more prone to cracking due to the complex heat unevenness.
Patent Document 1 prevents the occurrence of quenching cracks or fissures in the workpiece by setting the concentration of the water-soluble quenching agent relative to the total amount of cooling water (hereinafter simply referred to as the concentration of the cooling water) to 15% to 20%.

Figure 8 is a schematic diagram of a conventional high-frequency induction hardening apparatus 10. The conventional high-frequency induction hardening apparatus 10 will be explained using Figure 8.
The high-frequency induction hardening apparatus 10 comprises a main container 11 and a cooling water tank 12. The main container 11 has a cooling jacket 14, a heating coil 15, and an opening 19 at its top. The cooling water tank 12 and the cooling jacket 14 are connected by a connecting pipe 13. Cooling water is stored in the lower part of the main container 11. The heating coil 15 is located inside the main container 11, outside the surface of the workpiece 16 and inside the cooling jacket 14.
The piping, route 1 (25), connects the lower part of the main container 11 and the upper part of the cooling water tank 12. On route 1 (25), the first pump 51 and the first gate valve 41 are arranged in the order of first pump 51 and first gate valve 41, starting from the side closest to the lower part of the main container 11.
A concentration sensor 20 for measuring the concentration of the cooling water is placed in the cooling water tank 12, and the concentration of the cooling water is displayed on the display device 21.

The main operation of the conventional high-frequency induction hardening apparatus 10 will be explained below.
First, the workpiece 16 is inserted into the main container 11 and stopped in a position facing the cooling jacket 14.
Next, the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method.
Next, when the workpiece 16 is heated to a predetermined temperature, the power supply to the heating coil 15 is stopped. The second gate valve 42 is opened, and cooling water is supplied from the cooling water tank 12 to the cooling jacket 14, and the cooling water is sprayed from the cooling jacket 14 onto the workpiece 16. When the cooling water is sprayed onto the workpiece 16, the workpiece 16 is cooled.
When cooling water is being sprayed onto the workpiece 16, the first gate valve 41 is opened, the first pump 51 is driven, and the cooling water sprayed from the cooling jacket 14 is returned to the cooling water tank 12 via the path 1 (25).
Once the hardening of the workpiece 16 is complete, the workpiece 16 is removed from the main container 11.

Japanese Unexamined Patent Publication No. 170415/1986

The hardening process for prototypes and other workpieces (16) involves varying the concentration of the cooling water depending on the prototype.
In a conventional high-frequency induction hardening apparatus 10, when performing high-frequency induction hardening on multiple workpieces 16 in succession using cooling water with different concentrations, the following problems arise.

(When increasing the concentration of the cooling water)
For example, consider a case where the first quenching of workpiece 16 is performed with a cooling water concentration of 10%, and the second quenching of workpiece 16 is performed with a cooling water concentration of 15%.
In that case, for the second quenching of the workpiece 16, the concentration of the cooling water in the cooling water tank 12 needs to be increased from 10% to 15%. The cooling water in the cooling water tank 12 is normally always full.

To increase the cooling water concentration from 10% to 15%, a portion of the 10% concentration cooling water is taken from the cooling water tank 12, and concentrated water-soluble quenching agent is added to bring the concentration to 15%. The extracted 10% concentration cooling water is treated as wastewater. This wastewater treatment presented challenges in terms of time and cost.

(When lowering the concentration of the cooling water)
For example, consider a case where the first quenching of workpiece 16 is performed with a cooling water concentration of 10%, and the second quenching of workpiece 16 is performed with a cooling water concentration of 5%.
In that case, for the second quenching of the workpiece 16, the concentration of the cooling water in the cooling water tank 12 needs to be reduced from 10% to 5%. The cooling water in the cooling water tank 12 is normally always full.

Therefore, to lower the coolant concentration from 10% to 5%, a portion of the 10% concentration coolant is taken from the coolant tank 12, and water is added to bring the concentration down to 5%. The removed 10% concentration coolant is treated as waste liquid. However, waste liquid treatment presented challenges in terms of time and cost.

As described above, in the conventional high-frequency induction hardening apparatus 10, when high-frequency induction hardening is performed on multiple workpieces 16 in succession using cooling water with different concentrations, waste liquid is generated, which has the problem of being time-consuming and costly.
In view of the above issues, this disclosure provides a high-frequency induction hardening system that suppresses the generation of waste liquid in a high-frequency induction hardening system that performs hardening treatment on multiple workpieces in succession.

A high-frequency induction hardening system according to one aspect of the present disclosure is a high-frequency induction hardening system comprising a high-frequency induction hardening apparatus and a vacuum concentration apparatus, wherein the high-frequency induction hardening apparatus has a cooling water tank for storing cooling water in which a water-soluble hardening agent is added to water, a heating coil, and a cooling jacket, the high-frequency induction hardening apparatus is capable of arranging a workpiece in a position opposite the heating coil, heating the workpiece with the heating coil, cooling the workpiece by bringing the heated workpiece into contact with cooling water sprayed from the cooling jacket, performing a hardening treatment on the workpiece, and returning the cooling water sprayed from the cooling jacket to the cooling water tank, and the vacuum concentration apparatus has a main tank for concentrating the cooling water supplied from the high-frequency induction hardening apparatus to a predetermined concentration by reducing the pressure, and a concentrate tank to which the cooling water concentrated in the main tank is supplied, and when performing a hardening treatment on a workpiece, if the concentration in the cooling water tank is lower than the predetermined concentration, the concentrate tank is supplied with the cooling water tank to increase the concentration of the cooling water in the cooling water tank.
According to the above embodiment, the cooling water is concentrated by evaporating the water in the cooling water at a low temperature of less than 100°C (for example, 60°C or less) using a vacuum concentration device, so that the water-soluble quenching agent does not deteriorate and the cooling water can be used for a long period of time. In addition, when quenching multiple workpieces in succession in a high-frequency induction hardening system, no waste liquid is produced, and the generation of waste liquid can be suppressed.

A preferred embodiment is a high-frequency induction hardening system that includes the operation of supplying a portion of the cooling water from a cooling water tank to a main tank, reducing the pressure of the supplied portion of the cooling water in the main tank to concentrate it to a predetermined concentration, supplying the concentrated cooling water from the main tank to a concentrate tank, and supplying the concentrated cooling water supplied from the main tank to the concentrate tank back to the cooling water tank.
According to the above embodiment, when performing a continuous hardening treatment on multiple workpieces in a high-frequency induction hardening system, no waste liquid is generated, and the generation of waste liquid can be suppressed.

A more preferred embodiment is a high-frequency induction hardening system that includes the operation of supplying concentrated cooling water from a concentrate tank to a cooling water tank, increasing the concentration of the cooling water in the cooling water tank, and then performing a hardening treatment on the workpiece.
According to the above embodiment, when performing a continuous hardening treatment on multiple workpieces in a high-frequency induction hardening system, no waste liquid is generated, and the generation of waste liquid can be suppressed.

A more preferred embodiment is a high-frequency induction hardening system in which the vacuum concentration device further has a distilled water tank that evaporates the cooling water in the main tank as distilled water and stores the evaporated distilled water as water when the cooling water supplied from the high-frequency induction hardening device is concentrated to a predetermined concentration by reducing the pressure in the main tank.
According to the above embodiment, when performing a continuous hardening treatment on multiple workpieces in the high-frequency induction hardening system, water from a distilled water tank can be used, thus eliminating waste liquid and suppressing waste liquid generation.

Another high-frequency induction hardening system according to one aspect of the present disclosure is a high-frequency induction hardening system comprising a high-frequency induction hardening apparatus and a vacuum concentration apparatus, wherein the high-frequency induction hardening apparatus has a cooling water tank for storing cooling water in which a water-soluble hardening agent is added to water, a heating coil, and a cooling jacket, the high-frequency induction hardening apparatus is capable of placing a workpiece in a position opposite the heating coil, heating the workpiece with the heating coil, cooling the workpiece by bringing the heated workpiece into contact with cooling water sprayed from the cooling jacket, performing a hardening treatment on the workpiece, and returning the cooling water sprayed from the cooling jacket to the cooling water tank, and the vacuum concentration apparatus has a main tank for concentrating the cooling water supplied from the high-frequency induction hardening apparatus to a predetermined concentration by reducing the pressure, and a distilled water tank for evaporating the cooling water as distilled water when concentrating the cooling water in the main tank, and storing the evaporated distilled water as water, and when performing a hardening treatment on a workpiece, if the concentration in the cooling water tank is higher than a predetermined concentration, water is supplied from the distilled water tank to the cooling water tank to lower the concentration of the cooling water in the cooling water tank.
According to the above embodiment, the cooling water is concentrated by evaporating the water in the cooling water at a low temperature of less than 100°C (for example, 60°C or less) using a vacuum concentration device, so that the water-soluble quenching agent does not deteriorate and the concentrated cooling water can be stored for a long period of time. Furthermore, in the high-frequency induction hardening system, when quenching multiple workpieces in succession, no waste liquid is produced, and the generation of waste liquid can be suppressed.

A preferred embodiment is a high-frequency induction hardening system that includes the operation of supplying a portion of the cooling water from a cooling water tank to a main tank, reducing the pressure in the main tank to concentrate the supplied cooling water to a predetermined concentration, evaporating the supplied cooling water as distilled water, storing the evaporated distilled water as water in a distilled water tank, and supplying water from the distilled water tank to the cooling water tank.
According to the above embodiment, when performing a continuous hardening treatment on multiple workpieces in a high-frequency induction hardening system, no waste liquid is generated, and the generation of waste liquid can be suppressed.

A more preferred embodiment is a high-frequency induction hardening system that includes the operation of supplying water from a distilled water tank to a cooling water tank, reducing the concentration of the cooling water in the cooling water tank, and then performing a hardening treatment on the workpiece.
According to the above embodiment, when performing a continuous hardening treatment on multiple workpieces in the high-frequency induction hardening system, water from a distilled water tank is used, so no waste liquid is produced, and the generation of waste liquid can be suppressed.

A more preferred embodiment is a high-frequency induction hardening system in which, when the cooling water in the main tank is concentrated to a predetermined concentration by reducing the pressure in the main tank, the cooling water in the main tank is evaporated as distilled water, and the concentrated cooling water is supplied from the main tank to a concentrated liquid tank.
According to the above embodiment, concentrated cooling water can be stored in a concentrated liquid tank.

According to one aspect of this disclosure, in a high-frequency induction hardening system, the generation of waste liquid can be suppressed when hardening multiple workpieces in succession.

This is a schematic diagram of the high-frequency induction hardening system in Embodiment 1, which is one aspect of the present disclosure. This is a flowchart illustrating the general operation of a high-frequency induction hardening system with a high concentration of cooling water in Embodiment 1, which is one aspect of this disclosure. This flowchart shows the general operation of a high-frequency induction hardening system that reduces the concentration of cooling water in one embodiment of the present disclosure. This is a schematic diagram of the high-frequency induction hardening system in Embodiment 2, which is another aspect of the present disclosure. This is a schematic diagram of the high-frequency induction hardening system in the case of workpiece movement in Embodiment 2. This is a schematic diagram of the high-frequency induction hardening system in Embodiment 3, which is another aspect of the present disclosure. This is a schematic diagram of the high-frequency induction hardening system in Embodiment 4, which is another aspect of the present disclosure. This is a schematic diagram of a conventional high-frequency induction hardening apparatus.

The following describes more specific embodiments of this disclosure. However, unnecessary details may be omitted. For example, detailed descriptions of already well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessarily verbose descriptions and to facilitate understanding for those skilled in the art. The inventors provide the accompanying drawings and the following description to enable those skilled in the art to fully understand this disclosure, and do not intend to limit the subject matter described in the claims. In the following description, identical or similar components are denoted by the same reference numerals.

(Embodiment 1)
Hereinafter, a high-frequency induction hardening system 1, which represents one aspect of this disclosure, will be described with reference to the drawings.

Figure 1 is a schematic diagram of a high-frequency induction hardening system 1 showing one aspect of the present disclosure.
As shown in Figure 1, the high-frequency induction hardening system 1 comprises a high-frequency induction hardening apparatus 10 and a vacuum concentration apparatus 30.
The high-frequency induction hardening apparatus 10 is a device for hardening a workpiece 16 and comprises a main container 11 and a cooling water tank 12. The main container 11 has a cooling jacket 14, a heating coil 15, and an opening 19 at the top. The cooling water tank 12 and the cooling jacket 14 are connected by a connecting pipe 13, and a gate valve 42 is located in the connecting pipe 13. The cooling water in the cooling water tank 12 is normally always full.
Cooling water is stored in the lower part of the main container 11. The heating coil 15 is located inside the main container 11, outside the surface of the workpiece 16 and inside the cooling jacket 14.

The piping, route 1 (25), connects the lower part of the main container 11 and the upper part of the cooling water tank 12. On route 1 (25), the first pump 51 and the first gate valve 41 are arranged in the order of first pump 51 and first gate valve 41, starting from the side closest to the lower part of the main container 11.
The piping, route 2 (26), connects the lower part of the cooling water tank 12 to the upper part of the main tank 31 of the vacuum concentrator 30, which will be described later. On route 2 (26), the second pump 52 and the third gate valve 43 are arranged in the order of second pump 52 and third gate valve 43, starting from the side closest to the lower part of the cooling water tank 12.
A concentration sensor 20 for measuring the concentration of the cooling water is placed in the cooling water tank 12, and the concentration of the cooling water is displayed on the display device 21.

Now, let's explain the cooling water. Cooling water is a solution, and its solvent is water. The water-soluble quenching agents that are the solutes of the cooling water are water-soluble organic solutes such as polyalkylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol.
The concentration of the cooling water is, for example, 1% to 30%, preferably 5% to 20%. The temperature of the cooling water is, for example, 20°C to 40°C, preferably 29°C to 35°C.

The vacuum concentrator 30 comprises a main tank 31, a concentrate tank 32, and a distilled water tank 33. The vacuum concentrator 30 reduces the pressure in the main tank 31, boils the cooling water (the solution stored in the main tank 31) at a temperature below 100°C, and separates the cooling water into concentrate and distilled water. The vacuum concentrator 30 is also called a vacuum distillation concentrator or evaporator.
The concentrated liquid tank 32 stores the separated cooling water (concentrated liquid) which has a higher concentration. The distilled water tank 33 receives the separated distilled water and stores it as water.

The main tank 31 and the concentrated liquid tank 32 are connected by a piping route 3 (27).
On the path 3 (27), the third pump 53 and the fourth gate valve 44 are arranged in the order of the third pump 53 and the fourth gate valve 44, starting from the side closest to the bottom of the main tank 31.
The concentrated liquid tank 32 and the cooling water tank 12 are connected by a piping route 4 (28).
On the path 4 (28), the fourth pump 54 and the fifth gate valve 45 are arranged in the order of the fourth pump 54 and the fifth gate valve 45, starting from the side closest to the bottom of the concentrated liquid tank 32.
The distilled water tank 33 and the cooling water tank 12 are connected by a piping route 5 (29).
On the path 5 (29), the fifth pump 55 and the sixth gate valve 46 are arranged in the order of fifth pump 55 and sixth gate valve 46, starting from the side closest to the bottom of the distilled water tank 33.

Figure 2 is a flowchart illustrating the general operation of the high-frequency induction hardening system 1. The main operations of the high-frequency induction hardening system 1 will be explained using Figure 2.
The first quenching operation is the same as the conventional technique shown in Figure 8, so the explanation will be omitted.
At the completion of the first quenching operation, the cooling water tank 12 is almost full of cooling water. The second gate valve 42, the first gate valve 41, and the third gate valve 43 are closed.

The second quenching process will now be explained.

(When increasing the concentration of the cooling water)
Consider a case where, for example, a 10% concentration cooling water is used for the first quenching operation, and a 15% concentration cooling water is used for the second quenching operation.
Since the concentration of the cooling water used in the second quenching operation is higher than that of the cooling water used in the first quenching operation, it is necessary to increase the concentration of the cooling water in the first cooling water tank 12 after the first quenching operation is completed.

In S101 of Figure 2, a portion (a predetermined amount) of the cooling water from the cooling water tank 12 of the high-frequency induction hardening apparatus 10 is moved to the main tank 31 of the reduced-pressure concentration device 30. In other words, the amount of cooling water in the cooling water tank 12 is reduced.
Specifically, the third gate valve 43 is opened to drive the second pump 52, and a predetermined amount of cooling water is moved from the cooling water tank 12 to the main tank 31 via the path 2 (26). Once the predetermined amount of cooling water has been moved, the third gate valve 43 is closed and the operation of the second pump 52 is stopped.

In step S102, the cooling water supplied to the main tank 31 is concentrated to a predetermined concentration. Specifically, the pressure in the main tank 31 is reduced, and the water in the cooling water is evaporated at a low temperature of less than 100°C to concentrate the cooling water to the predetermined concentration. The evaporated water vapor is supplied to the distilled water tank 33 and stored as water.

In S103, the cooling water concentrated to a predetermined concentration is supplied from the main tank 31 to the concentrate tank 32. Specifically, the fourth gate valve 44 is opened, the third pump 53 is driven, and the concentrated cooling water is supplied from the main tank 31 to the concentrate tank 32 via the path 3 (27). Once the supply of concentrated cooling water is complete, the fourth gate valve 44 is closed, and the operation of the third pump 53 is stopped. Here, the cooling water concentrated to a predetermined concentration is referred to as cooling water 1. Alternatively, the concentrated cooling water in the concentrate tank 32 may be moved to another tank for storage.

In S104, concentrated cooling water (cooling water 1) is supplied from the concentrate tank 32 to the cooling water tank 12, and cooling water 1 is supplied so that the cooling water in the cooling water tank 12 reaches a predetermined concentration (here, 15%; this cooling water is called cooling water 2). The concentration of cooling water 1 is concentrated to be higher than the concentration of cooling water 2.
Specifically, the fifth gate valve 45 is opened, the fourth pump 54 is driven, and cooling water 1 is supplied from the concentrate tank 32 to the cooling water tank 12 via the path 4 (28). Once the supply is complete, the fifth gate valve 45 is closed, and the operation of the fourth pump 54 is stopped.

In step S105, the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method.

In S106, the second gate valve 42 is opened to supply cooling water from the cooling water tank 12 to the cooling jacket 14.

In step S107, cooling water is sprayed from the cooling jacket 14, bringing the heated workpiece 16 into contact with the sprayed cooling water to cool the workpiece 16, thereby quenching it.

In S108, the injected cooling water is returned to the cooling water tank 12. Specifically, when cooling water is injected from the cooling jacket 14, the first gate valve 41 is opened, driving the first pump 51 and returning the cooling water from the main container 11 to the cooling water tank 12. This circulation continues until the quenching is complete.

Once the hardening process is complete, the first gate valve 41 and the second gate valve 42 are closed, the drive of the first pump 51 is stopped, and the series of operations is completed.

According to the above embodiment, the cooling water is concentrated by evaporating the water in the cooling water at a low temperature of less than 100°C using the vacuum concentration device 30. Therefore, the water-soluble quenching agent does not deteriorate, and the cooling water can be used for a long period of time. Furthermore, when quenching multiple workpieces 16 consecutively in the high-frequency induction hardening system 1, no waste liquid is generated, thus suppressing the generation of waste liquid.

(When lowering the concentration of the cooling water)
Let's consider a case where, for example, a 10% concentration cooling water is used for the first quenching operation, and a 5% concentration cooling water is used for the second quenching operation.
Since the concentration of the cooling water used in the second quenching operation is lower than that of the cooling water used in the first quenching operation, it is necessary to lower the concentration of the cooling water in the first cooling water tank 12 after the first quenching operation is completed.
At the completion of the first quenching operation, the cooling water tank 12 is almost full of cooling water. The second gate valve 42, the first gate valve 41, and the third gate valve 43 are closed.

Figure 3 is a flowchart illustrating the general operation of the high-frequency induction hardening system 1, which reduces the concentration of the cooling water. The general operation of the high-frequency induction hardening system 1 will be explained using Figure 3.

In step S201 of Figure 3, a portion (a predetermined amount) of the cooling water in the cooling water tank 12 is transferred from the cooling water tank 12 to the main tank 31 so that the cooling water in the cooling water tank 12 reaches a predetermined concentration (here, from 10% to 5%). In other words, the amount of cooling water in the cooling water tank 12 is reduced.

In step S202, the cooling water in the main tank 31 is concentrated to a predetermined concentration, and the distilled water is stored in the distilled water tank 33. Specifically, the pressure in the main tank 31 is reduced, and the cooling water is concentrated by evaporating it at a low temperature of less than 100°C. The evaporated water vapor is supplied to the distilled water tank 33 and stored as water.

In S203, concentrated cooling water is supplied from the main tank 31 to the concentrate tank 32, and the concentrated cooling water is stored. Specifically, the fourth gate valve 44 is opened to drive the third pump 53, supplying concentrated cooling water from the main tank 31 to the concentrate tank 32. Once the cooling water supply is complete, the fourth gate valve 44 is closed to stop the third pump 53 from operating. Alternatively, the concentrated cooling water in the concentrate tank 32 may be moved to another tank for storage.

In S204, water is supplied from the distilled water tank 33 to the cooling water tank 12 to dilute the cooling water so that its concentration reaches a predetermined concentration (in this case, 5% as displayed on the display device 21). Specifically, the sixth gate valve 46 is opened to drive the fifth pump 55 and supply water from the distilled water tank 33 to the cooling water tank 12. Once the water supply is complete, the sixth gate valve 46 is closed to stop the fifth pump 55 from operating.

In step S205, the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method.

In S206, the second gate valve 42 is opened to supply cooling water from the cooling water tank 12 to the cooling jacket 14.

In step S207, cooling water is sprayed from the cooling jacket 14, bringing the heated workpiece 16 into contact with the sprayed cooling water to cool the workpiece 16, thereby quenching it.

In step S208, the cooling water sprayed from the main container 11 is returned to the cooling water tank 12. Specifically, when cooling water is sprayed from the cooling jacket 14, the first gate valve 41 is opened, driving the first pump 51 to return the cooling water from the main container 11 to the cooling water tank 12. This circulation continues until the quenching is complete.

Once the hardening process is complete, the first gate valve 41 and the second gate valve 42 are closed, and the operation of the first pump 51 is stopped, thus completing the process.

According to the above embodiment, the cooling water is concentrated by evaporating the water in the cooling water at a low temperature of less than 100°C using the vacuum concentration device 30, so that the water-soluble quenching agent does not deteriorate and the concentrated cooling water can be stored for a long period of time. In addition, when quenching multiple workpieces 16 in succession in the high-frequency induction hardening system 1, no waste liquid is produced, and the generation of waste liquid can be suppressed.

(Embodiment 2)

Hereinafter, Embodiment 2, which is a high-frequency induction hardening system 1 illustrating another aspect of this disclosure, will be described with reference to the drawings.
Figure 4 is a schematic diagram of the high-frequency induction hardening system in Embodiment 2. Cooling water is stored in the lower part of the main container 11, at a height greater than or equal to the height of the workpiece 16 (see Figure 5).
Embodiment 2 differs from Embodiment 1 in that the entire workpiece 16 is immersed in the cooling water stored in the lower part of the main container 11.

Steps S101 to S104 in Figure 2 of Embodiment 1 and steps S201 to S204 in Figure 3 are the same operation.
The following describes the steps after the process in which the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method (S105 and S205).

As shown in Figure 4, the workpiece 16 is heated by the heating coil 15. When the workpiece 16 is heated, it reaches a predetermined temperature. When the workpiece 16 reaches the predetermined temperature and a predetermined time has elapsed, the heating of the workpiece 16 is stopped.
Then, as shown in Figure 5, the entire workpiece 16 is immersed in the cooling water stored in the lower part of the main container 11. By immersing the entire workpiece 16, the workpiece 16 is cooled and subjected to a quenching treatment. As the temperature of the stored cooling water rises due to the workpiece 16, the cooling jacket 14 sprays cooling water to lower the temperature of the stored cooling water. Finally, similar to Embodiment 1, the cooling water sprayed by the cooling jacket 14 is returned to the cooling water tank 12.
According to the above embodiment, a workpiece 16 with a large heat capacity can be cooled.

(Embodiment 3)

Hereinafter, Embodiment 3, which is a high-frequency induction hardening system 1 representing another aspect of the present disclosure, will be described with reference to the drawings.
Embodiment 3 differs from Embodiment 1 in that the workpiece 16 has a cylindrical shape with a hollow interior, and the workpiece 16 is heated and cooled from the inside.

Figure 6 is a schematic diagram of the high-frequency induction hardening system 1 in Embodiment 3. In Figure 6, the workpiece 16 is cylindrical in shape with a hollow interior.
A heating coil 15 is placed inside the workpiece 16, and a cooling jacket 14 is placed inside the heating coil 15.
The heating coil 15 heats the workpiece 16 from the inside. When the workpiece 16 is heated, it reaches a predetermined temperature. When the workpiece 16 reaches the predetermined temperature and a predetermined time has elapsed, the heating of the workpiece 16 is stopped.
Then, the cooling jacket 14 sprays cooling water from inside the workpiece 16 to cool the workpiece 16 and perform a heat treatment on the workpiece 16.
Other operations are the same as in Embodiment 1.
According to the above embodiment, the inside of the cylindrical workpiece 16 can be hardened.

(Embodiment 4)

Hereinafter, Embodiment 4, which is a high-frequency induction hardening system 1 illustrating another aspect of the present disclosure, will be described with reference to the drawings.
Embodiment 4 differs from Embodiment 1 in that, instead of the main container 11, the sprayed cooling water is dropped into a low-height receiving tray 60 or onto the floor, and the dropped cooling water is returned to the cooling water tank 12.

Figure 7 is a schematic diagram of the high-frequency induction hardening system 1 in Embodiment 4. As shown in Figure 7, the cooling water from the cooling jacket 14 is received in a low-height tray 60 or on the floor. The cooling water is then returned from the low-height tray 60 or on the floor to the cooling water tank 12.
Other operations are the same as in Embodiment 1.
According to the above embodiment, a large amount of cooling water is sprayed onto the workpiece 16, so a hardening treatment with high cooling capacity can be performed.

In Figure 2, cooling water is moved from the cooling water tank 12 to the main tank 31 (S101), concentrated in the main tank 31 (S102), and the concentrated cooling water is supplied from the concentrate tank 32 to the cooling water tank 12 (S103). However, before the quenching treatment, that is, before the start of Figure 2, steps S101 to S103 may be performed in advance, leaving concentrated cooling water in the concentrate tank 32. The concentrated cooling water could then be supplied directly from the concentrate tank 32 to the cooling water tank 12 without going through steps S101 to S103.

In Figure 3, cooling water is moved from the cooling water tank 12 to the main tank 31 (S201), concentrated in the main tank 31 (S202), the concentrated cooling water is supplied from the concentrate tank 32 to the cooling water tank 12 (S203), and water is supplied from the distilled water tank 33 to the cooling water tank 12 (S204). However, before the quenching treatment, that is, before the start of Figure 3, steps S201 to S203 may be performed in advance, leaving water in the distilled water tank 33, and water may be supplied directly from the distilled water tank 33 to the cooling water tank 12 without going through steps S201 to S203.

Furthermore, in Figure 3, although step S202 is performed before step S203, steps S202 and S203 may be performed in parallel.

In embodiments 1 to 4, the entire workpiece 16 was heated by the heating coil 15 and cooled by bringing it into contact with cooling water. However, it is also possible to partially heat the workpiece 16 with the heating coil 15 while moving the workpiece 16, and then cool the partially heated area by bringing it into contact with cooling water.

Furthermore, the inventions according to Embodiments 1 to 4 can be substituted or combined, as long as no contradictions arise.

1. High-frequency induction hardening system 10. High-frequency induction hardening apparatus 11. Main container 12. Cooling water tank 14. Cooling jacket 15. Heating coil 16. Workpiece 20. Concentration sensor 21. Display device 30. Vacuum concentration apparatus 31. Main tank 32. Concentrated liquid tank 33. Distilled water tank 41. First gate valve 42. Second gate valve 43. Third gate valve 44. Fourth gate valve 45. Fifth gate valve 46. Sixth gate valve 51. First pump 52. Second pump 53. Third pump 54. Fourth pump 55. Fifth pump

Claims (8)

A high-frequency induction hardening system comprising a high-frequency induction hardening apparatus and a vacuum concentration apparatus,
The high-frequency induction hardening apparatus comprises a cooling water tank for storing cooling water in which a water-soluble hardening agent is added to water, a heating coil, a cooling jacket , and a main container having the heating coil and cooling jacket inside .
The high-frequency induction hardening apparatus has a path 1 which is a pipe connecting the lower part of the main container and the upper part of the cooling water tank.
The high-frequency induction hardening apparatus places the workpiece in a position opposite the heating coil, heats the workpiece with the heating coil, supplies cooling water stored in a cooling water tank to a cooling jacket, sprays the supplied cooling water from the cooling jacket, cools the workpiece by bringing it into contact with the heated workpiece and the cooling water sprayed from the cooling jacket, performs hardening on the workpiece, stores the cooling water sprayed from the cooling jacket in the lower part of the main container, and can return the cooling water stored in the lower part of the main container to the upper part of the cooling water tank via the path 1 .
The vacuum concentration device comprises a main tank that concentrates the cooling water supplied from the cooling water tank of the high-frequency induction hardening device to a predetermined concentration by reducing the pressure, and a concentrated liquid tank to which the cooling water concentrated in the main tank is supplied.
A high-frequency induction hardening system characterized by supplying concentrated cooling water from a concentrate tank to the cooling water tank to increase the concentration of the cooling water in the cooling water tank when the concentration of the cooling water in the cooling water tank is lower than a predetermined concentration when performing a hardening treatment on a workpiece. The high-frequency induction hardening system according to claim 1, characterized in that it includes the operation of supplying a portion of the cooling water from the cooling water tank to the main tank, reducing the pressure of the supplied portion of the cooling water in the main tank to concentrate it to a predetermined concentration, supplying the concentrated cooling water from the main tank to the concentrate tank, and supplying the concentrated cooling water supplied from the main tank to the concentrate tank from the concentrate tank to the cooling water tank. The high-frequency induction hardening system according to claim 1 or 2, characterized by including the operation of supplying concentrated cooling water from a concentrated liquid tank to a cooling water tank, increasing the concentration of the cooling water in the cooling water tank, and then performing a hardening treatment on the workpiece. The vacuum concentration device further comprises a distilled water tank that stores the evaporated distilled water as water when concentrating the cooling water supplied from the high-frequency induction hardening device in the main tank under reduced pressure to a predetermined concentration, as described in any one of claims 1 to 3. A high-frequency induction hardening system comprising a high-frequency induction hardening apparatus and a vacuum concentration apparatus,
The high-frequency induction hardening apparatus comprises a cooling water tank for storing cooling water in which a water-soluble hardening agent is added to water, a heating coil, a cooling jacket , and a main container having the heating coil and cooling jacket inside .
The high-frequency induction hardening apparatus has a path 1 which is a pipe connecting the lower part of the main container and the upper part of the cooling water tank.
The high-frequency induction hardening apparatus places the workpiece in a position opposite the heating coil, heats the workpiece with the heating coil, supplies cooling water stored in a cooling water tank to a cooling jacket, sprays the supplied cooling water from the cooling jacket, cools the workpiece by bringing it into contact with the heated workpiece and the cooling water sprayed from the cooling jacket, performs hardening on the workpiece, stores the cooling water sprayed from the cooling jacket in the lower part of the main container, and can return the cooling water stored in the lower part of the main container to the upper part of the cooling water tank via the path 1 .
The vacuum concentration apparatus comprises a main tank that concentrates the cooling water supplied from the cooling water tank of the high-frequency induction hardening apparatus to a predetermined concentration by reducing the pressure, and a distilled water tank that evaporates the cooling water as distilled water when concentrating the cooling water in the main tank, and stores the evaporated distilled water as water.
A high-frequency induction hardening system characterized by supplying water from a distilled water tank to the cooling water tank to lower the concentration of the cooling water in the cooling water tank when the concentration of the cooling water in the cooling water tank is higher than a predetermined concentration when performing a hardening treatment on a workpiece. The high-frequency induction hardening system according to claim 5, characterized by including the operation of supplying a portion of the cooling water from the cooling water tank to the main tank, concentrating a portion of the supplied cooling water in the main tank by reducing the pressure to a predetermined concentration, evaporating a portion of the supplied cooling water as distilled water, storing the evaporated distilled water as water in the distilled water tank, and supplying water from the distilled water tank to the cooling water tank. The high-frequency induction hardening system according to claim 5 or 6, characterized by including the operation of supplying water from a distilled water tank to a cooling water tank, lowering the concentration of the cooling water in the cooling water tank, and then performing a hardening treatment on the workpiece. The vacuum concentration device further comprises a concentrated liquid tank supplied from the main tank to a predetermined concentration, characterized in that, when the cooling water in the main tank is concentrated by reducing the pressure, the cooling water in the main tank is evaporated as distilled water, and the concentrated cooling water is supplied from the main tank. This is the high-frequency induction hardening system according to any one of claims 5 to 7.