High-frequency induction hardening system

Abstract

To suppress the generation of waste solution when a number of workpiece are continuously quenched in a high-frequency quenching system.SOLUTION: A high-frequency quenching system according to the present disclosure includes a high-frequency quenching device having a cooling water tank and a decompression concentrator having a main body tank and a concentrator tank. When a work is quenched, if the concentration of the cooling water tank is lower than a prescribed concentration, a part of the cooling water in the cooling water tank is supplied to the main body tank. The supplied cooling water is decompressed in the main body tank and concentrated to a prescribed concentration. The concentrated cooling water is supplied from the main body tank to the concentrator tank. The concentrated cooling water is supplied from the concentrator tank to the cooling water tank to increase the concentration of the cooling water in the cooling water tank so that the cooling water in the cooling water tank has the prescribed concentration.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a high-frequency quenching system for quenching steel machine parts, forgings, etc., such as various machine parts and automatic parts, using a water-soluble quenchant.

Background Art

[0002] Generally, in order to prevent distortion of the workpiece during quenching, when quenching forgings, etc., cooling water, which is a solution obtained by adding 5 to 10% of a water-soluble quenchant (water-soluble organic solute), which is a solute, to water as a solvent, is sprayed onto the workpiece while maintaining the liquid temperature at room temperature. However, even when using cooling water added with a water-soluble quenchant, cracking may occur even when the quality and performance are good. The reasons are as follows: (1) When water comes into contact with metal in a high-temperature state, a large amount of latent heat of vaporization is suddenly taken away during the evaporation of water, resulting in excessive rapid cooling. (2) In addition, since the state of the water on the metal surface is different for each part, such as bubbles and vapor, intense heat unevenness occurs. (3) In addition, forgings, in particular, have a large amount of stress accumulated inside, and cracks are more likely to occur along with complex heat unevenness. Patent Document 1 prevents the occurrence of cracking or fissures in the workpiece by setting the concentration of the water-soluble quenchant in the entire cooling water (hereinafter, simply referred to as the concentration of the cooling water) to 15% to 20%.

[0003] FIG. 8 is a schematic configuration diagram of a conventional high-frequency quenching apparatus 10. The conventional high-frequency quenching apparatus 10 will be described using FIG. 8. The high-frequency quenching apparatus 1 is provided with a main body container 11 and a cooling water tank 12. The main body container 11 has a cooling jacket 14, a heating coil 15, and an opening 19 at the upper part. The cooling water tank 12 and the cooling jacket 14 are connected by a communication pipe 13. Cooling water accumulates at the lower part of the main body container 11. The heating coil 15 is disposed inside the main body 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 is placed in the cooling water tank 12 to measure the concentration of the cooling water, and the concentration of the cooling water is displayed on the display device 21.

[0004] The main operation of the conventional high-frequency induction hardening apparatus 10 will be described 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 cut off. 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. Once 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 path 1(25). Once the hardening of the workpiece 16 is complete, the workpiece 16 is removed from the main container 11. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 170415 / 1983 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The hardening process for prototypes and other workpieces (workpiece 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.

[0007] (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, the second quenching of the workpiece 16 requires increasing the concentration of the cooling water in the cooling water tank 12 from 10% to 15%. The cooling water in the cooling water tank 12 is normally always full.

[0008] To increase the concentration of the coolant from 10% to 15%, a portion of the 10% concentration coolant is taken from the coolant tank 12, and concentrated water-soluble quenching agent is added to bring the coolant concentration to 15%. The extracted 10% concentration coolant is treated as waste liquid. However, waste liquid treatment presented challenges in terms of time and cost.

[0009] (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 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.

[0010] 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 coolant concentration down to 5%. The removed 10% concentration coolant is then treated as wastewater. However, wastewater treatment presented challenges in terms of time and cost.

[0011] 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. [Means for solving the problem]

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] Another high-frequency quenching system according to an aspect of the present disclosure is a high-frequency quenching system including a high-frequency quenching device and a vacuum concentration device. The high-frequency quenching device has a cooling water tank for storing cooling water with a water-soluble quenchant added thereto, a heating coil, and a cooling jacket. The high-frequency quenching device arranges a workpiece at a position facing the heating coil, heats the workpiece with the heating coil, cools the workpiece by bringing the heated workpiece into contact with the cooling water ejected from the cooling jacket, performs a quenching process on the workpiece, and can return the cooling water ejected from the cooling jacket to the cooling water tank. The vacuum concentration device has a main body tank for concentrating the cooling water supplied from the high-frequency quenching device under reduced pressure to a predetermined concentration, and a distilled water tank for evaporating the cooling water as distilled water and storing the evaporated distilled water as water when concentrating the cooling water in the main body tank. When performing a quenching process on the workpiece, when the concentration of the cooling water in the cooling water tank is higher than the 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 aspect, by using the vacuum concentration device to evaporate the water in the cooling water at a low temperature below 100 °C (for example, 60 °C or lower) to concentrate the cooling water, the water-soluble quenchant does not deteriorate, and the concentrated cooling water can be stored for a long time. Further, in the high-frequency quenching system, when continuously performing a quenching process on a plurality of workpieces, no waste liquid is generated, and the generation of waste liquid can be suppressed.

[0017] A preferred aspect is a high-frequency quenching system including an operation of supplying a part of the cooling water in the cooling water tank to the main body tank, concentrating a part of the supplied cooling water in the main body tank under reduced pressure to a predetermined concentration, evaporating a part 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. According to the above aspect, in the high-frequency quenching system, when continuously performing a quenching process on a plurality of workpieces, no waste liquid is generated, and the generation of waste liquid can be suppressed.

[0018] A more preferred embodiment is a high-frequency quenching system including an 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 quenching process on the workpiece. According to the above embodiment, in the high-frequency quenching system, when continuously quenching a plurality of workpieces, the water in the distilled water tank is used, so that no waste liquid is generated and the generation of waste liquid can be suppressed.

[0019] A more preferred embodiment is a high-frequency quenching system in which the vacuum concentration device further has a concentrated liquid tank in which the cooling water concentrated in the main body tank is supplied from the main body tank while evaporating the cooling water in the main body tank as distilled water and concentrating the cooling water in the main body tank to a predetermined concentration. According to the above embodiment, the concentrated cooling water can be stored in the concentrated liquid tank.

Effect of the Invention

[0020] According to one embodiment of the present disclosure, in a high-frequency quenching system, when continuously quenching a plurality of workpieces, the generation of waste liquid can be suppressed.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic configuration diagram of a high-frequency quenching system in Embodiment 1 which is one embodiment of the present disclosure. [Figure 2] In Embodiment 1 which is one embodiment of the present disclosure, it is a flowchart showing a schematic operation of a high-frequency quenching system for increasing the concentration of cooling water. [Figure 3] In Embodiment 1 which is one embodiment of the present disclosure, it is a flowchart showing a schematic operation of a high-frequency quenching system for reducing the concentration of cooling water. [Figure 4] It is a schematic configuration diagram of a high-frequency quenching system in Embodiment 2 which is another embodiment of the present disclosure. [Figure 5] In Embodiment 2, it is a schematic configuration diagram of the high-frequency quenching system when the workpiece moves. [Figure 6]This is a schematic diagram of the high-frequency induction hardening system in Embodiment 3, which is another aspect of the present disclosure. [Figure 7] This is a schematic diagram of the high-frequency induction hardening system in Embodiment 4, which is another aspect of the present disclosure. [Figure 8] This is a schematic diagram of a conventional high-frequency induction hardening apparatus. [Modes for carrying out the invention]

[0022] More specific embodiments of the present disclosure are described below. However, some unnecessarily detailed descriptions may be omitted. For example, detailed descriptions of already well-known matters or redundant descriptions of substantially identical components may be omitted. This is to avoid the following description becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. The inventors provide the accompanying drawings and the following description so that those skilled in the art can fully understand the present disclosure, and not to limit the subject matter described in the claims. In the following description, identical or similar components are denoted by the same reference numerals.

[0023] (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.

[0024] Figure 1 is a schematic diagram of a high-frequency induction hardening system 1, which represents 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.

[0025] 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 is placed in the cooling water tank 12 to measure the concentration of the cooling water, and the concentration of the cooling water is displayed on the display device 21.

[0026] 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.

[0027] 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.

[0028] 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 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.

[0029] 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. Upon 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.

[0030] I will now explain the second quenching process.

[0031] (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.

[0032] 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 transferred 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 to stop the operation of the second pump 52.

[0033] In 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 a predetermined concentration. The evaporated water vapor is supplied to the distilled water tank 33 and stored as water.

[0034] In S103, 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 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.

[0035] In S104, concentrated coolant (coolant 1) is supplied from the concentrate tank 32 to the coolant tank 12, and coolant 1 is supplied so that the coolant in the coolant tank 12 reaches a predetermined concentration (here, 15%; this coolant is called coolant 2). The concentration of coolant 1 is concentrated to be higher than the concentration of coolant 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.

[0036] In step S105, the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method.

[0037] In S106, the second gate valve 42 is opened to supply cooling water from the cooling water tank 12 to the cooling jacket 14.

[0038] In step S107, cooling water is sprayed from the cooling jacket 14, and the heated workpiece 16 is brought into contact with the cooling water sprayed from the cooling jacket 14 to cool the workpiece 16, thereby hardening the workpiece 16.

[0039] In step S108, the injected coolant is returned to the coolant tank 12. Specifically, when coolant is injected from the cooling jacket 14, the first gate valve 41 is opened, the first pump 51 is driven, and the coolant is returned from the main container 11 to the coolant tank 12. This circulation continues until the quenching is complete.

[0040] 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.

[0041] 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 cooling water can be used 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.

[0042] (When lowering the concentration of the cooling water) Consider a scenario 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. Upon 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.

[0043] 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.

[0044] In step S201 of Figure 3, a portion (a predetermined amount) of the cooling water in the cooling water tank 12 is moved 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.

[0045] 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.

[0046] In step S203, concentrated cooling water is supplied from the main tank 31 to the concentrate tank 32, and the concentrated cooling water is stored there. Specifically, the fourth gate valve 44 is opened to drive the third pump 53, which supplies concentrated cooling water from the main tank 31 to the concentrate tank 32. When the supply of cooling water is finished, the fourth gate valve 44 is closed to stop the third pump 53 from driving. Alternatively, the concentrated cooling water in the concentrate tank 32 may be moved to another tank for storage.

[0047] 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 becomes 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 running.

[0048] In step S205, the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method.

[0049] In S206, the second gate valve 42 is opened to supply cooling water from the cooling water tank 12 to the cooling jacket 14.

[0050] In step S207, cooling water is sprayed from the cooling jacket 14, and the heated workpiece 16 is brought into contact with the cooling water sprayed from the cooling jacket 14 to cool the workpiece 16, thereby quenching the workpiece 16.

[0051] In step S208, the cooling water injected from the main container 11 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, the first pump 51 is driven, and the cooling water is returned from the main container 11 to the cooling water tank 12. This circulation is continued until the quenching is complete.

[0052] 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 to complete the process.

[0053] 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)

[0054] 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 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.

[0055] The steps S101 to S104 in Figure 2 of Embodiment 1 and the steps S201 to S204 in Figure 3 are the same operation. The following describes the processes from the step in which the workpiece 16 is heated by the heating coil 15 using a high-frequency induction heating method (S105 and S205) onward.

[0056] 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)

[0057] Hereinafter, Embodiment 3, which is a high-frequency induction hardening system 1 illustrating another aspect of this 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.

[0058] 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 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. Once 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)

[0059] Hereinafter, Embodiment 4, which is a high-frequency induction hardening system 1 representing another aspect of this 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 tray 60 or onto the floor, and the dropped cooling water is returned to the cooling water tank 12.

[0060] 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 injected onto the workpiece 16, so a quenching treatment with high cooling capacity can be performed.

[0061] In Figure 2, cooling water is moved from the cooling water tank 12 to the main tank 31 (S101), the cooling water is 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, and the concentrated cooling water may be supplied directly from the concentrate tank 32 to the cooling water tank 12 without going through steps S101 to S103.

[0062] In Figure 3, cooling water is moved from the cooling water tank 12 to the main tank 31 (S201), the cooling water is 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.

[0063] In addition, although in steps S202 and S203 of Figure 3, step S202 was performed first, followed by step S203, steps S202 and S203 may be performed in parallel.

[0064] 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, the workpiece 16 may also be partially heated by the heating coil 15 while moving the workpiece 16, and the partially heated portion may be cooled by bringing it into contact with cooling water.

[0065] Furthermore, the inventions according to Embodiments 1 to 4 can be substituted or combined, as long as no contradictions arise. [Explanation of symbols]

[0066] 1. High-frequency induction hardening system 10. High-frequency induction hardening equipment 11 Main container 12 Cooling water tank 14 Cooling Jacket 15 Heating coil 16 Work 20 Concentration Sensor 21 Display device 30 Vacuum Concentrator 31 Main Tank 32 Concentrated liquid tanks 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. ​​The sixth gate valve 51 First pump 52. Second pump 53 The third pump 54 The fourth pump 55 The fifth pump

Claims

1. 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 reduces the pressure of the cooling water supplied from the cooling water tank of the high-frequency induction hardening device and concentrates it to a predetermined concentration, 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.

2. 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.

3. The high-frequency induction hardening system according to claim 1 or 2, characterized in that it includes 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.

4. The high-frequency induction hardening system according to any one of claims 1 to 3, further characterized in that the vacuum concentration device 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.

5. 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.

6. The high-frequency induction hardening system according to claim 5, 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 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 the distilled water tank, and supplying water from the distilled water tank to the cooling water tank.

7. The high-frequency induction hardening system according to claim 5 or 6, characterized in that it includes 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.

8. The vacuum concentration device further comprises a concentrated liquid tank to which the concentrated cooling water is supplied from the main tank, characterized in that 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 also concentrated. This is the high-frequency induction hardening system according to any one of claims 5 to 7.

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