JP6713964B2 - Quenching equipment - Google Patents

Description

The present disclosure relates to a quenching device that quenches a workpiece such as a machine part.

BACKGROUND ART Conventionally, as a device for quenching a workpiece such as a mechanical component (eg, gear or shaft), a quenching device including a heating chamber for heating the workpiece and a cooling tank for cooling the workpiece heated in the heating chamber has been proposed. (For example, see Patent Document 1).

The cooling tank of the quenching apparatus of Patent Document 1 is filled with oil (quenching oil) as a coolant for cooling the work. The work is cooled by immersing the work in the quenching oil in the cooling tank.

When the quenching device of Patent Document 1 is operated, the temperature of the quenching oil used for cooling the work rises each time. Therefore, it is necessary to cool the quenching oil to a predetermined temperature in preparation for the next cooling process. Therefore, a cooling device for cooling the temperature of the quenching oil as in Patent Document 2 has been proposed.

JP, 2014-237886, A JP, 6-158148, A

However, in the case of using the quenching oil cooling device as in Patent Document 2, after cooling a certain work, the quenching oil is cooled and heated until the next work comes, and the quenching oil is maintained at a predetermined heat retention temperature. There is a need to. On the other hand, the method of processing the work includes a continuous method of continuously processing the work and a batch method of collectively processing a plurality of works, and the time interval until the next work is conveyed to the cooling tank is also set. Varies (eg, minutes to hours).

In such a case, particularly when the time interval until the next work is conveyed is long, the heat retention operation for keeping the temperature of the quenching oil long. As described above, the temperature control of the coolant such as quenching oil for cooling the work may be inefficiently performed, and it can be said that there is still room for improvement in efficiently performing the temperature control of the coolant. ..

The present disclosure solves the above problems, and an object of the present disclosure is to provide a quenching apparatus that can more efficiently control the temperature of a coolant.

A quenching apparatus according to an aspect of the present disclosure is a quenching apparatus that quenches a work, and includes a cooling tank containing a liquid coolant for cooling the heat-treated work, and a cooling agent in the cooling tank. A cooling unit, a heating unit that heats the coolant in the cooling tank, a temperature measurement unit that measures the temperature of the coolant in the cooling tank, and a control unit that controls the operation of the cooling unit and the heating unit. And the control unit releases the coolant without operating the cooling unit and the heating unit after the quenching time of the work with the coolant, and before the next work is input. When the temperature measured by the temperature measuring unit for the coolant is higher than the predetermined heat retention temperature at a predetermined timing, the cooling unit is operated to control to cool the coolant.

According to the above configuration, after the quenching time of the work, the cooling agent is not cooled and the cooling agent is allowed to cool, and the cooling section is started based on the measured temperature of the cooling agent thereafter. As a result, temperature control can be performed more efficiently than in the conventional case where the cooling unit is operated to perform forced cooling immediately after cooling the work.

In the quenching apparatus, the control unit, before the predetermined timing, when the measured temperature is lower than the heat retention temperature, instead of the operation of the cooling unit, until the next work is input. In the meantime, the heating unit may be controlled so that the measured temperature approaches the heat retention temperature. Thus, by maintaining the temperature of the coolant near the heat retention temperature, the temperature of the coolant can be set to the heat retention temperature when the next work is input, and the desired cooling process can be performed on the work.

In the quenching apparatus, the control unit, after operating the cooling unit at the predetermined timing, until the next work is input, the measured temperature approaches the heat retention temperature, the heating unit. You may control so that it may drive. Thus, by maintaining the temperature of the coolant near the heat retention temperature, the temperature of the coolant can be set to the heat retention temperature when the next work is input, and the desired cooling process can be performed on the work.

In the quenching device, the control unit has a prediction program for predicting a temperature transition when cooling the coolant and/or a prediction program for predicting a temperature transition when cooling the coolant in the cooling unit, The timing for starting the operation of the cooling unit may be determined based on the prediction program so that the measured temperature becomes the heat retention temperature when or before the next work is input. Thereby, the temperature control of the coolant can be performed more efficiently.

In the quenching apparatus, the control unit may determine the timing to start the operation of the cooling unit so that the measured temperature becomes the heat retention temperature when the next work is input. As a result, it is possible to perform control without operating the heating unit, and it is possible to more efficiently control the temperature of the coolant.

According to the present disclosure, the temperature control of the coolant can be performed more efficiently.

The figure which shows schematic structure of the hardening apparatus of Embodiment 1. The figure which shows an example of the flow of the hardening process by the hardening apparatus of Embodiment 1. The figure which shows an example of the flow of the hardening process by the hardening apparatus of Embodiment 1. The figure which shows an example of the flow of the hardening process by the hardening apparatus of Embodiment 1. The figure which shows an example of the flow of the hardening process by the hardening apparatus of Embodiment 1. The figure which shows an example of the flow of the hardening process by the hardening apparatus of Embodiment 1. The figure which shows an example of the temperature transition of a coolant when temperature control is performed by the temperature control mechanism of the quenching apparatus of Embodiment 1. The figure which shows an example of the temperature transition of a coolant when temperature control is performed by the temperature control mechanism of the quenching apparatus of Embodiment 1. The figure which shows the example of the temperature transition of the coolant when the conventional temperature control method is performed. The figure which shows the example of the temperature transition of the coolant at the time of controlling the temperature by the temperature control mechanism of the quenching apparatus of Embodiment 2.

Hereinafter, preferred embodiments of a quenching apparatus and a quenching method according to the present disclosure will be described with reference to the accompanying drawings. The present disclosure is not limited to the specific configurations of the following embodiments, and configurations based on the same technical idea are included in the present disclosure.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of a quenching device 2 according to the first embodiment.

The quenching device 2 shown in FIG. 1 is a heat treatment furnace as a device for quenching a workpiece W (machine part (eg, gear, shaft) etc.) as an object to be treated.

The quenching device 2 shown in FIG. 1 has a function of performing a cooling process in addition to a heating process of the work W, and is configured as a multi-chamber heat treatment furnace that constitutes a plurality of spaces. As shown in FIG. 1, the quenching device 2 includes a heating chamber 4, a relay chamber 6, a cooling tank 8, a carrier tray 10, a lift elevator 12, a first door 14, and a second door 16. , A third door 18, a control unit 20, and a temperature control mechanism 24.

When the quenching device 2 is operated, the work W is heat-treated in the heating chamber 4, and the heat-treated work W is horizontally conveyed to the relay chamber 6 and then lowered to the cooling tank 8 below by the elevator 12 for cooling. To process. In such a configuration, the cooling tank 8 contains a liquid coolant C (oil, water, chemical liquid, etc.) for cooling (quenching) the work W.

The cooling tank 8 is provided with a temperature control mechanism 24 for controlling the temperature of the coolant C. The temperature control mechanism 24 shown in FIG. 1 includes a stirring unit 26, a motor 28, a temperature measuring unit 30, a heating unit 32, a cooling flow path 33, a pump 34, and a cooling unit 36. These functions will be described later.

The invention of the present disclosure is particularly characterized by the method for controlling the temperature of the coolant C by the temperature control mechanism 24, and a specific method will be described later.

Next, each component of the quenching device 2 will be described.

The heating chamber 4 is a space for heat-treating the work W. The work W is heated to a predetermined temperature in the heating chamber 4. FIG. 1 illustrates a state in which the work W is arranged in the heating chamber 4.

A first door 14 and a second door 16 are provided as doors for loading and unloading the work W into and from the heating chamber 4. The first door 14 and the second door 16 are moved up and down by a drive mechanism (not shown). The heating chamber 4 can be opened and closed by the vertical movement of the first door 14 and the second door 16. Since the third door 18 has the same configuration, the description will be omitted.

The relay chamber 6 is a space provided beside the heating chamber 4. The relay chamber 6 is a space that serves as a relay point when the work W heated in the heating chamber 4 moves to the cooling tank 8. In the example of FIG. 1, the cooling tank 8 is provided below the relay chamber 6.

The cooling tank 8 is a tank for cooling the work W. The cooling tank 8 according to the first embodiment has a function of performing an oil-cooling type cooling process, and contains oil at a predetermined temperature (for example, 120° C.) as a liquid coolant C.

The transport tray 10 is a member for placing and transporting the work W in the quenching device 2. Similarly, the elevating elevator 12 is a member for elevating the transport tray 10 on which the work W is placed between the relay chamber 6 and the cooling tank 8.

The control unit 20 is a member that controls the operation of the quenching device 2. The control unit 20 is electrically connected to each component of the quenching device 2 described above, and can control the operation of each component. The control unit 20 is composed of, for example, a microcomputer.

Next, each component of the temperature control mechanism 24 will be described.

The stirring unit 26 is a member that stirs the coolant C in the cooling tank 8. By stirring by the stirring unit 26, the temperature of the coolant C in the cooling tank 8 is made uniform. The stirring unit 26 shown in FIG. 1 has a propeller 26a at its tip and is rotationally driven by a motor 28.

The temperature measuring unit 30 is a member that measures the temperature of the coolant C in the cooling tank 8. Although the temperature measuring unit 30 in the first embodiment is a thermocouple (temperature sensor), the temperature measuring unit 30 is not limited to this, and may have any configuration capable of measuring the temperature of the coolant C in the cooling tank 8.

The heating unit 32 is a member that heats the coolant C in the cooling tank 8. Although the heating unit 32 in the first embodiment is a heater, the present invention is not limited to this, and may be any configuration capable of heating the coolant C in the cooling tank 8.

The cooling channel 33 is a channel for sending the coolant C in the cooling tank 8 to a cooling unit 36 described later. The cooling channel 33 shown in FIG. 1 is provided as a channel that bypasses the cooling tank 8. The cooling flow path 33 includes an upstream flow path 33 a connected from the cooling tank 8 to the cooling unit 36, and a downstream flow path 33 b connected from the cooling unit 36 to the cooling tank 8.

The pump 34 is a pump for drawing the coolant C in the cooling tank 8 into the upstream flow path 33 a and sending it to the cooling unit 36.

The cooling unit 36 is a member that cools the coolant C. Although the cooling unit 36 in the first embodiment is a heat exchanger, the present invention is not limited to this and may be any configuration as long as it can cool the coolant C in the cooling tank 8.

The operation of each component of the temperature control mechanism 24 described above is controlled by the control unit 20.

An example of the flow of the quenching process when the quenching device 2 configured as above is operated will be described with reference to FIGS. 2A to 2E.

First, as shown in FIG. 2A, the work W is carried into the heating chamber 4. Specifically, the first door 14 is lifted and opened. The heating chamber 4 is preheated by a heater or the like (not shown) provided inside. Next, the work W placed on the transport tray 10 outside the hardening device 2 is carried into the hardening device 2 (A1 in the figure). The carrying tray 10 may be carried in by any carrying mechanism such as a roller (not shown) on which the carrying tray 10 is placed, which is rotationally driven from the outside. After that, the first door 14 is lowered and closed, and the work W in the heating chamber 4 is heated to a predetermined temperature (for example, 850° C.).

Next, the transfer tray 10 is moved to the relay chamber 6. Specifically, the second door 16 is lifted and opened, and the work W after the heat treatment is horizontally moved toward the relay chamber 6 (A2 in the figure). The transfer mechanism (not shown) is used to move the transfer tray 10.

As shown in FIG. 2B, the transfer tray 10 and the work W are placed on the elevator 12 in the relay room 6. After that, the second door 16 is lowered and closed.

Next, as shown in FIG. 2C, the transport tray 10 is lowered into the cooling tank 8 by using the lift elevator 12. Due to the lowering of the elevating elevator 12, the carrier tray 10 is placed in the cooling tank 8 and the work W is immersed in the liquid coolant C (A3 in the figure). As a result, the work W is cooled to a predetermined temperature (for example, 120° C.) and quenched.

The work W for which the cooling process in the cooling tank 8 is completed is then returned to the relay chamber 6 as shown in FIG. 2D (A4 in the figure). After that, as shown in FIG. 2E, the third door 18 is opened, and the transport tray 10 on which the work W is placed is carried out of the quenching device 2 (A5 in the figure).

By performing the processing of FIGS. 2A-2E described above, the quenching processing for the work W is executed. A similar quenching process is performed on a plurality of works W that are sequentially loaded into the quenching device 2.

When such a quenching process is continued, the temperature of the coolant C in the cooling tank 8 used for cooling the work W rises with each quenching process (for example, rises to about 140° C.). On the other hand, when the next work W is put into the cooling tank 8, the temperature of the coolant C needs to be lowered to a predetermined temperature (for example, 120° C.). That is, it is necessary to cool the coolant C each time the quenching process is completed.

In the quenching device 2 of the first embodiment, the temperature control mechanism 24 described above is used to control the temperature of the coolant C. A specific temperature control method will be described with reference to FIGS.

3 and 4 are graphs showing the temperature transition of the coolant C when the temperature of the coolant C is controlled by the temperature control mechanism 24 of the first embodiment. In FIGS. 3 and 4, the horizontal axis represents time and the vertical axis represents temperature (temperature measured by the temperature measuring unit 30).

As shown in FIGS. 3 and 4, the temperature control mechanism 24 of the first embodiment releases the coolant C without operating the heating unit 32 and the cooling unit 36 after the quenching time X1 for one work W is completed. A cold operation (heat radiation) is performed (cooling time X2, X5). In parallel with the cooling operation of the cooling agent C, the temperature of the cooling agent C is continuously measured by the temperature measuring unit 30 (for example, every 1 minute), and the measured temperature is increased by a predetermined timing Xt. Determines whether the temperature is lower than the heat retention temperature T1.

The quenching time X1 is the time from when the work W is attached to the coolant C to when it is pulled up. The predetermined timing Xt is a timing stored (set) in the control unit 20 in advance as a time point (for example, 10 minutes before) the time point Xn when the next work W is loaded into the cooling tank 8 ( The time point Xn at which the next work W is put into the cooling tank 8 is also stored in the control unit 20). The heat retention temperature T1 is a temperature stored in advance in the control unit 20 as a desired temperature of the coolant C at the start of the cooling process of the work W.

The example shown in FIG. 3 shows a case where the measured temperature does not fall below the heat retention temperature T1 by the predetermined timing Xt. In such a case, the cooling operation of the coolant C is continued without operating the heating unit 32 and the cooling unit 36 from the end of the quenching time X1 to the predetermined timing Xt (cooling time X2).

Then, the cooling unit 36 is operated at a predetermined timing Xt. The coolant C is cooled by the operation of the cooling unit 36 and reaches the heat retention temperature T1 (cooling time X3).

Furthermore, after the measured temperature of the coolant C reaches the heat retention temperature T1, the heat retention operation is performed to intermittently operate the heating unit 32 so that the measured temperature approaches the heat retention temperature T1 (heat retention time X4).

On the other hand, FIG. 4 shows a case where the measured temperature of the coolant C falls below the heat retention temperature T1 by the predetermined timing Xt. As shown in FIG. 4, after the quenching time X1 ends, the cooling operation is performed until a predetermined timing Xt (cooling time X5), and then the operation of the cooling unit 36 shown in FIG. 3 (cooling time X3) is changed. Then, the same heat retention operation as that shown in FIG. 3 is performed until the time point Xn when the next work W is loaded into the cooling tank 8 (heat retention time X6).

According to the control shown in FIGS. 3 and 4, the temperature of the coolant C is maintained at the heat retention temperature T1 in any case at the time Xn when the next work W is introduced into the cooling tank 8. .. As a result, a desired cooling process can be performed on the next work W.

FIG. 5 shows an example of the temperature transition of the coolant C by the conventional temperature control method in contrast to the temperature control method of the first embodiment described above.

In the conventional example shown in FIG. 5, the cooling unit 36 is operated immediately after the quenching time X1 of the work W ends (cooling time X7). After that, until the time point Xn when the next work W is loaded, the heat retention operation is performed at the heat retention temperature T1 (heat retention time X8).

According to such a temperature control method, both the cooling time X7 and the heat retention time X8 become long, and in particular, the later the time point Xn when the next work W is input, the longer the heat retention time X8 becomes. As a result, the heat-retaining operation for controlling the ON/OFF of the heating unit 32 becomes long, resulting in an inefficient temperature control method.

On the other hand, according to the temperature control method of the first embodiment described above, after the quenching time X1 of the workpiece W is finished, the cooling unit 36 and the heating unit 32 are not allowed to cool, and the cooling agent is used thereafter. The operation of the cooling unit 36 is started based on the measured temperature of C. According to such a method, as compared with the conventional example shown in FIG. 5, the period for operating the cooling unit 36 and the period for operating the heating unit 32 are shortened, and particularly the period for operating the heating unit 32 is significantly shortened. can do. Thereby, the temperature control of the coolant C can be performed more efficiently.

(Embodiment 2)
A temperature control method for the coolant C according to the second embodiment of the present disclosure will be described. In the second embodiment, points different from the first embodiment will be mainly described, and the description overlapping with the first embodiment will be omitted.

In the second embodiment, in addition to the temperature control method of the first embodiment, the control unit 20 has a prediction program for predicting the temperature transition of the coolant C, and temperature control is performed based on the prediction program. Different from the form 1.

The prediction program according to the second embodiment includes a temperature transition of the coolant C when the coolant C is allowed to cool without operating the cooling unit 36 and a temperature of the coolant C when the coolant C is cooled by the cooling unit 36. It predicts the transition. The temperature transition when the coolant C is allowed to cool can be obtained from, for example, an arithmetic expression that predicts the temperature transition based on factors such as the type of the coolant C and the heat radiation amount from the cooling tank 8. Further, the temperature transition when the cooling agent 36 is cooled by the cooling unit 36 is based on factors such as the type of the cooling agent C, the amount of heat released from the cooling tank 8 and the magnitude of the output of the cooling unit 36. It can be obtained from the calculation formula to be predicted.

FIG. 6 shows an example of the temperature transition of the coolant C by the temperature control method of the second embodiment.

As shown in FIG. 6, according to the temperature control method of the second embodiment, based on the above-described prediction program, the cooling time for cooling the coolant C is X9, and the cooling unit 36 cools after the cooling time X9. The cooling time X10 for cooling the agent C is set. Specifically, the operation start timing of the cooling unit 36, which is the timing of switching from the cooling time X9 to the cooling time X10, is determined based on the prediction program.

In the second embodiment, in particular, the operation start timing of the cooling unit 36 is determined so that the measured temperature of the coolant C becomes exactly the heat retention temperature T1 at the time point Xn when the next work W is input. As a result, the heat retention operation using the heating unit 32 becomes unnecessary, and the desired cooling process for the next work W can be performed only by operating the cooling unit 36. By such a method, the temperature of the coolant C can be controlled more efficiently.

When the prediction program is used, an air temperature measuring unit, a timer, and a cooling rate storage unit may be provided as a new configuration of the quenching device 2. Thereby, the heat quantity required for cooling can be calculated from the heating temperature, the specific heat of the work W, and the weight.

Although the invention of the present disclosure has been described with reference to the above-described first and second embodiments, the invention of the present disclosure is not limited to the above-described first and second embodiments. For example, in the above-described first embodiment, the heating unit 32 and the cooling unit 36 are illustrated in FIG. 1 as different configurations, but the present invention is not limited to such a case. The cooling unit and the heating unit may be in the same place, or a device in which the functions of cooling and heating are combined may be used.

Although the case where the coolant C housed in the cooling tank 8 is the quenching oil has been described in the first embodiment, the present invention is not limited to such a case and may be a liquid coolant other than oil.

Further, in the first embodiment, the case where the work W is conveyed in the order shown in FIGS. 2A to 2E has been described, but the present invention is not limited to such a case. As long as the heating process is performed in the heating chamber 4 and then the cooling process is performed in the cooling tank 8, the sheets may be conveyed in any order. In addition, one that heats and cools in one processing chamber, or a wall without the third door 18 is used as a wall and the cooled work W opens and closes the second door 16 and the first door 14 to restore the original work. The configuration of the transfer path and the processing chamber may be changed according to the processing type of the work W, such as a batch method of returning to the position.

In the first embodiment, the case where the ON/OFF of the heating unit 32 is repeated is explained as the heat retention operation for bringing the temperature of the work W close to the heat retention temperature T1, but the method is not limited to such a method. Any operation method using the heating unit 32 and/or the cooling unit 36 may be used as long as the temperature of the work W can be brought close to the heat retention temperature T1.

Further, in the second embodiment, the case where the prediction program predicts both the temperature transition when the coolant C is left to cool and the temperature transition when the coolant C is cooled by the cooling unit 36 is described. However, it is not limited to such a case. It may be a case where only one of the predictions is performed. In other words, the control unit 20 has a prediction program that predicts the temperature transition when the coolant C is left to cool, and/or a prediction program that predicts the temperature transition when the coolant C is cooled by the cooling unit 36. May be.

In the second embodiment, the case where the cooling unit 36 is started so that the measured temperature of the coolant C is exactly the heat retention temperature T1 at the time point Xn when the next work W is input has been described. Not limited to Before the next work W is loaded, the operation start timing of the cooling unit 36 may be determined based on the prediction program so that the measured temperature of the coolant C becomes the heat retention temperature T1.

By properly combining the arbitrary embodiments of the aforementioned various embodiments, the effects possessed by them can be produced.

While the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. It is to be understood that such variations and modifications are included within the scope of the present disclosure as defined by the appended claims. In addition, the combination of elements and the change in order in each embodiment can be realized without departing from the scope and concept of the present disclosure.

The present disclosure can be applied to any quenching device that quenches a work.

2 Quenching device 4 Heating chamber 6 Relay chamber 8 Cooling tank 10 Transport tray 12 Elevating elevator 14 First door 16 Second door 18 Third door 20 Control unit 24 Temperature control mechanism 26 Stirring unit 26a Propeller 28 Motor 30 Temperature measurement Part 32 Heating part 33 Cooling flow path 33a Upstream flow path 33b Downstream flow path 34 Pump 36 Cooling part C Coolant W Workpiece T1 Insulation temperature X1 Quenching time X2, X5, X9 Cooling time X3, X7, X10 Cooling time X4 , X6, X8 Insulation time Xt Predetermined timing Xn When the next work is put into the cooling tank

Claims (4)

A quenching device for quenching a work,
A cooling tank containing a liquid coolant for cooling the heat-treated work,
A cooling unit for cooling the coolant in the cooling tank,
A heating unit for heating the coolant in the cooling tank,
A temperature measurement unit for measuring the temperature of the coolant in the cooling tank,
A control unit for controlling the operation of the cooling unit and the heating unit,
The control unit, after the quenching time of the work by the coolant, allows the coolant to cool without operating the cooling unit and the heating unit, at a predetermined timing before the next work is input, When the measured temperature of the coolant by the temperature measurement unit is higher than a predetermined heat retention temperature, the cooling unit is operated to control to cool the coolant ,
The control unit has a prediction program that predicts a temperature transition when the coolant is left to cool and/or a prediction program that predicts a temperature transition when the coolant is cooled by the cooling unit, and the next work is input. A quenching device that determines the timing to start the operation of the cooling unit based on the prediction program so that the measured temperature becomes the heat retention temperature before or at the time of being performed. If the measured temperature is lower than the heat retention temperature before the predetermined timing, the control unit replaces the operation of the cooling unit with the measured temperature until the next work is input. Controls the said heating part to operate|move so that it may approach the said heat retention temperature, The quenching apparatus of Claim 1. The control unit controls the heating unit so that the measured temperature approaches the heat retention temperature after the cooling unit is operated at the predetermined timing and until the next work is input. The quenching device according to claim 1 or 2. The quenching according to any one of claims 1 to 3, wherein the control unit determines the timing of starting the operation of the cooling unit so that the measured temperature becomes the heat retention temperature when the next work is input. apparatus.

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