JP2009047368A - Cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid wasting material by easily adapting when a cooling system is changed; to reduce the whole cost; to improve cooling efficiency and stabilize cooling temperature in the whole cooling system; to contribute to improvement of durability of the cooling system. <P>SOLUTION: A reservoir tank part 2 is composed of a plurality of tank members 2a corresponding to the number of cooling circuits 3a, and the respective tank members 2a are incorporated in the cooling circuits 3a of a plurality of systems. Feeding paths 4a supplied with cooling fluid W from the respective cooling circuits 3a and the respective cooling circuits 3a are joined by respective returning paths 5a through which the cooling fluid W returns to connect with a cooled part M. Fluid surface detection parts 6a for detecting heights Hw of fluid surfaces Wf of the cooling fluid W housed in the respective tank members 2a and flow rate control parts 7a for controlling flow rates of the cooling fluid W flowing through the corresponding returning paths 5a, according to detection results of the respective fluid surface detection parts 6a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling system including a plurality of cooling circuits that perform cooling by circulating a coolant stored in a storage tank portion to a predetermined portion to be cooled.

  Conventionally, a cooling system that circulates cooling liquid cooled by a plurality of cooling circuits to a predetermined portion to be cooled and cools the portion to be cooled is known, for example, in Patent Literature 1 and Patent Literature 2. Since this type of cooling system includes a plurality of cooling circuits, each cooling circuit can be used in accordance with the cooling performance and cooling accuracy required in the portion to be cooled. For example, in the case of Patent Document 1, the cooling accuracy is improved by properly using a plurality of cooling circuits, and in the case of Patent Document 2, a plurality of cooling circuits are used for troubleshooting. In addition, even if a cooling circuit with a small cooling capacity is used, it is possible to increase the substantial cooling capacity by using a plurality of cooling circuits at the same time. Therefore, it is possible to flexibly cope with various parts to be cooled. Can do.

By the way, in this type of cooling system including a plurality of cooling circuits, a plurality of cooling circuits are usually connected to one storage tank unit that contains cooling liquid, including Patent Document 1 and Patent Document 2. Yes. That is, like the cooling system 100 shown in FIG. 9, a plurality of cooling circuits 101a, 101b, and 101c are connected to the shared storage tank unit 102, and the coolant W stored in the storage tank unit 102 is supplied to each cooling circuit 101a, The cooling liquid W in the storage tank unit 102 was circulated to the cooled part 110 using the circulation circuit 103 including the liquid feed pump 103p separately connected to the storage tank unit 102, while being cooled by 101b and 101c.
JP-A-5-126418 JP-A-8-219615

  However, the conventional cooling system described above has the following problems.

  First, since a common storage tank is used for a plurality of cooling circuits, the cooling system cannot be easily changed. For example, when upgrading two installed cooling circuits to three cooling circuits, the storage tank part used in the two systems can no longer be used, so it is necessary to prepare a newly designed storage tank part. There is a waste of material and an increase in cost.

  Second, the cooling of each cooling circuit tends to vary. That is, since the temperature of the cooling liquid in the storage tank cannot be made completely uniform, it is likely to cause a problem such that the cooling load is shifted to a specific cooling circuit. Therefore, the cooling efficiency is likely to be lowered and the cooling temperature of the whole cooling liquid is unstable, and the durability of the entire cooling system is reduced.

  The object of the present invention is to provide a cooling system that solves such problems in the background art.

  In order to solve the above-described problems, the present invention configures a cooling system 1 including a plurality of cooling circuits that circulate cooling liquid W stored in a storage tank unit 2 through a predetermined cooled part M and perform cooling. The storage tank unit 2 is composed of a plurality of tank members 2a, 2b, 2c corresponding to the number of cooling circuits 3a, 3b, 3c, and each tank member 2a, 2b, 2c is composed of a plurality of cooling circuits 3a, 3b, 3c, respectively, and supply paths 4a, 4b, 4c to which the cooling liquids W are supplied from the respective cooling circuits 3a, 3b, 3c, and return paths for returning the cooling liquids W to the respective cooling circuits 3a, 3b, 3c. 5a, 5b, 5c are joined together and connected to the cooled portion M, and the liquid level for detecting the height Hw ... of the liquid level Wf ... of the coolant W ... contained in each tank member 2a, 2b, 2c. Detection unit 6 , 6b, 6c and the flow rate for controlling the flow rate of the coolant W ... flowing through the corresponding return paths 5a, 5b, 5c or the supply paths 4a, 4b, 4c according to the detection results of the liquid level detectors 6a, 6b, 6c. Control units 7a, 7b and 7c are provided.

  In this case, according to a preferred aspect of the present invention, the liquid level detectors 6a ... are installed above the coolant W ... contained in the tank members 2a ... so that the height Hw ... of the liquid level Wf ... is not contacted. The reflection type distance sensors 11a to be detected can be used. In this case, the tank members 2a can be provided with wave suppression plates 12a for suppressing the wave of the liquid level Wf detected by the reflection type distance sensors 11a, and the wave suppression plates 12a for heat conduction. It is possible to use the support plate 13a for supporting the reflection type distance sensors 11a. Moreover, the air blower 14a ... which ventilates to the reflection type distance sensor 11a ..., and prevents the condensation of the said reflection type distance sensor 11a ... can be provided. On the other hand, the flow rate control unit 7a ... performs signal processing of the control valve 15a ... for controlling the flow rate of the coolant W ... flowing through the return path 5a ... or the supply path 4a ... and the detection signal Sad ... obtained from the liquid level detection unit 6a ... Then, it can be constituted by signal processing circuits 16a supplied to the control valves 15a. On the other hand, if the coolant blocking means 17a ... for blocking the coolant W ... flowing in the return path 5a ... or the supply path 4a ... is provided and the coolant W ... is shut off by the coolant blocking means 17a ... A controller 19 having a control function for stopping the liquid feed pumps 18a built in the cooling circuits 3a after the time Tf has elapsed can be provided. In addition, the controller 19 can be provided with a control function for starting the liquid feeding pumps 18a after a predetermined set time Ts has elapsed if the blocking of the cooling liquids W ... by the cooling liquid blocking means 17a ... is released. Further, the controller 19 supplies the coolant flowing through the return path 5a or the supply path 4a by the coolant blocking means 17a when the height Hw of the liquid level Wf is equal to or higher than the predetermined upper limit height He. It is possible to provide a control function for shutting off W over a predetermined set time Te. In addition, it is desirable to connect the backflow prevention valves 20a, 20b, and 20c to each supply path 4a.

  According to the cooling system 1 according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) The storage tank section 2 is constituted by a plurality of tank members 2a... Corresponding to the number of cooling circuits 3a... And each tank member 2a is incorporated in a plurality of cooling circuits 3a. The liquid level detection unit 6a for detecting the height Hw of the liquid level Wf of the cooling liquid W contained in the ... and the return path 5a corresponding to the detection result of each liquid level detection unit 6a ... or supply Since the flow rate control units 7a... For controlling the flow rate of the coolants W flowing in the paths 4a... Are provided, it is possible to easily cope with the case where the cooling system 1 is changed. In particular, the old storage tank section becomes unnecessary or it becomes unnecessary to prepare a newly designed storage tank section, so that waste of materials can be avoided and the overall cost can be reduced.

  (2) Since the cooling liquid W that has been cooled for each of the cooling circuits 3a can be supplied, variation in cooling (cooling load) for each cooling circuit 3a can be suppressed. Therefore, the cooling efficiency of the entire cooling system 1 can be improved and the cooling temperature can be stabilized, and the durability of the cooling system 1 can be improved.

  (3) According to a preferred embodiment, the liquid level detectors 6a ... are installed above the cooling liquid W ... contained in the tank members 2a ... to detect the height Hw ... of the liquid level Wf ... in a non-contact manner. If the mold distance sensors 11a are used, the height Hw of the liquid level Wf can be accurately detected without contacting the coolant W.

  (4) According to a preferred embodiment, if the tank members 2a are provided with wave suppression plates 12a that suppress the wave of the liquid level Wf detected by the reflection type distance sensor 11a, the liquid level Wf is unnecessary. High-precision detection can be performed while suppressing vertical fluctuation.

  (5) According to a preferred embodiment, when the wave suppression plates 12a are formed of a heat conductive material and are also used as the support plates 13a for supporting the reflection type distance sensors 11a, the cooling liquid W and the reflection type are used. By reducing the temperature difference between the distance sensors 11a, the condensation of the reflective distance sensors 11a can be prevented.

  (6) According to a preferred embodiment, if a blower 14a is provided to blow air to the reflective distance sensors 11a to prevent condensation of the reflective distance sensors 11a, condensation should occur in the reflective distance sensors 11a. Can be removed quickly.

  (7) According to a preferred embodiment, the flow rate control unit 7a is detected from the control valve 15a for controlling the flow rate of the coolant W flowing in the return path 5a or the supply path 4a and the liquid level detection unit 6a. If the signal processing circuit 16a... Is configured to process the signal Sad... And supply it to the control valve 15a..., The flow rate control system can be simplified to improve control responsiveness and reliability, and to reduce cost. Can also contribute.

  (8) According to a preferred embodiment, there is provided a coolant blocking means 17a for blocking the coolant W flowing in the return path 5a or the supply path 4a, and the coolant W is blocked by the coolant blocking means 17a. If a controller 19 having a control function for stopping the liquid supply pumps 18a built in the cooling circuits 3a after a predetermined set time Tf has elapsed is provided, the response delay of the flow rate control system including the control valves 15a. Therefore, it is possible to prevent the stoppage of the liquid feed pump 18a in a state where the coolant W is not completely shut off, and the coolant W in the tank members 2a increases unnecessarily. Can avoid the problem.

  (9) According to a preferred embodiment, the controller 19 has a control function for starting the liquid feeding pumps 18a ... after a predetermined set time Ts has elapsed if the coolant 19 is shut off by the coolant shut-off means 17a ... If provided, the response delay of the flow rate control system including the control valves 15a can be offset, so that the liquid feed pumps 18a can be prevented from starting in a state where the blocking of the coolant W is not completely released, The problem that the coolant W in the tank members 2a decreases unnecessarily can be avoided.

  (10) According to a preferred embodiment, when the height Hw of the liquid level Wf is equal to or greater than the predetermined upper limit height He ..., the return path 5a ... or the supply path 4a is supplied to the controller 19 by the coolant blocking means 17a ... If a control function for shutting off the coolant W flowing in the ... for a predetermined set time Te ... is provided, it is possible to quickly protect against the occurrence of a failure or the like.

  (11) If the backflow prevention valves 20a ... are connected to the supply passages 4a ... according to a preferred embodiment, even if the supply passages 4a ... of the plurality of cooling circuits 3a ... are joined, the supply passages 4a ... Since backflow to the side is blocked, interference between the cooling circuits 3a can be prevented.

  Next, the best embodiment according to the present invention will be given and described in detail with reference to the drawings.

  First, the configuration of the cooling system 1 according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the cooling system 1 includes three systems of cooling circuits 3a, 3b, and 3c. Each cooling circuit 3a, 3b, 3c is configured as an independent unit. Therefore, although the illustration is constituted by three cooling circuits 3a ..., basically any quantity can be combined. Each of the cooling circuits 3a, 3b, 3c is supplied with cooling liquid W ... in the supply paths 4a, 4b, 4c and the cooling circuits 3a, 3b, 3c that supply the cooling liquid W ... from the cooling circuits 3a, 3b, 3c to the outside. Since the return paths 5a, 5b, and 5c are returned, the supply paths 4a, 4b, and 4c are joined and connected to the cooled part M, and the returned paths 5a, 5b, and 5c are joined and cooled. Connect to. The cooled portion M is an electric device or a machine tool that is cooled by the cooling system 1. Therefore, the coolant W supplied from the cooling system 1 passes through the inside of the cooled part M and is subjected to heat exchange, and the heat-exchanged coolant W is returned to the cooling system 1 again.

  On the other hand, in this type of cooling system, since it is necessary to circulate a required amount of the coolant W to the cooled portion M, the storage tank portion 2 that can accommodate the amount of the coolant W corresponding to the cooled portion M is provided. Necessary. In the cooling system 1 according to the present embodiment, the storage tank unit 2 is constituted by three tank members 2a, 2b, 2c corresponding to the number of cooling circuits 3a, 3b, 3c, and each tank member 2a, 2b, 2c Built in the cooling circuits 3a, 3b, 3c.

  FIG. 2 shows a specific configuration of one cooling circuit 3a. 2a is a tank member built in the cooling circuit 3a, and a specific configuration is shown in FIGS. The tank member 2a is configured by a rectangular parallelepiped tank main body 2am having an opening at the upper end capable of containing the coolant W therein, and a cover portion 2ar covering the upper end of the tank main body 2am, thereby improving the cooling capacity of the cooling circuit 3a. Select the corresponding volume. In addition, the forming material of the tank main body part 2am and the cover part 2ar illustrated is a stainless steel material.

  The tank member 2a is provided with a wave suppression plate 12a that suppresses the wave of the liquid level Wf. The wave suppression plate 12a is formed of a heat conductive material, preferably the same material (stainless steel) as the tank member 2a, and as shown in FIGS. 3 and 5, a punching panel Pn having a large number of small holes h. Use. As shown in FIG. 4, the wave suppression plate 12a is bent into an L shape and attached to a corner portion in the tank body 2am. At this time, the lower end of the wave suppression plate 12a reaches the bottom surface of the tank main body 2am or near the bottom surface, and the upper end (upper portion) of the wave suppression plate 12a has a predetermined height upward from the opening at the upper end of the tank main body 2am. Make it protrude. Therefore, the cover portion 2ar is formed or configured in a shape that allows the wave suppression plate 12a to penetrate upward. As a result, a small chamber Ra surrounded by the wave suppression plate 12a is formed inside the tank body 2am, and even if a wave is generated on the liquid level Wf of the coolant W outside the small chamber Ra, the wave suppression plate 12a. And is not transmitted to the liquid level Wf in the small chamber Ra.

  On the other hand, the tank member 2a is provided with a liquid level detection unit 6a for detecting the height Hw of the liquid level Wf of the coolant W accommodated in the tank main body 2a. The liquid level detector 6a uses a reflective distance sensor 11a that is installed above the coolant W and detects the height Hw of the liquid level Wf in a non-contact manner. The illustrated reflective distance sensor 11a is an ultrasonic sensor including a transmitter and a receiver. If such a reflective distance sensor 11a is used for the liquid level detection unit 6a, there is an advantage that the height Hw of the liquid level Wf can be accurately detected without contacting the cooling liquid W. In this case, the portion of the wave suppressing plate 12a that protrudes upward from the upper end opening of the tank main body 2am also serves as the support plate 13a that supports the reflective distance sensor 11a. Therefore, as shown in FIG. 5, the reflective distance sensor 11a can be attached to the support plate 13a. Reference numeral 31 denotes a mounting bracket for mounting the reflective distance sensor 11a to the support plate 13a. Thereby, the reflection-type distance sensor 11a suppresses waves by the wave suppression plate 12a, that is, performs highly accurate detection with respect to the height Hw of the liquid level Wf in the small chamber Ra in which unnecessary vertical fluctuation of the liquid level Wf is suppressed. It can be carried out. In addition, the wave suppression plate 12a is formed of a thermally conductive material and also serves as a support plate 13a that supports the reflective distance sensor 11a, so that the temperature difference between the coolant W and the reflective distance sensor 11a is reduced. Therefore, there is an advantage that the condensation of the reflective distance sensor 11a can be prevented.

  The blower 14a is attached to the cover portion 2ar. The blower 14a includes a blower body 14af and a blower cover 14ac, and has a function of blowing air to the reflective distance sensor 11a to prevent condensation of the reflective distance sensor 11a. In this case, a blowing guide 32 is interposed between the reflective distance sensor 11a and the blower 14a. By this blower guide 32, the blower from the blower 14a is guided to the most necessary part of the reflection type distance sensor 11a for preventing condensation. Therefore, even if dew condensation should occur in the reflection type distance sensor 11a, there is an advantage that it can be quickly removed.

  On the other hand, as shown in FIG. 2, the supply port 33 provided in the tank member 2a is connected to the inflow side of the supply path 4a, and in the middle of the supply path 4a, from the tank member 2a side, the liquid feed pumps 18a, The cooling unit 34, the manual valve 35, and the backflow prevention valve 20a are sequentially connected. In this case, the cooling unit 34 includes a heat exchanger 34m and a refrigeration cycle 34c, and connects the primary side of the heat exchanger 34m to the refrigeration cycle 34c and connects the secondary side of the heat exchanger 34m to the supply path 4a. . Reference numeral 36 denotes a hydraulic pressure gauge connected to the supply path 4a on the outflow side of the heat exchanger 34m. A return port 37 provided in the tank member 2a is connected to the outflow side of the return path 5a. A manual valve 38, a control valve 15a, and a flow meter 39 are connected to the return path 5a from the tank member 2a side. Connect sequentially. In addition, 41 is a manual valve connected between the outflow side of the heat exchanger 34m and the return port 37 described above, and 42 is connected between the outflow side of the manual valve 38 and the inflow side of the manual valve 35, and the hydraulic pressure is not less than a set value. , A pressure regulating valve 43 that bypasses the coolant W, and a manual valve 43 that is connected in parallel to the control valve 15a and is used when the control valve 15a fails.

  In this case, the control valve 15a controls the flow rate of the coolant W flowing through the return path 5a, and uses the electric valve 15am. Therefore, the opening degree of the electric valve 15am is variably controlled in accordance with the magnitude of the control signal Sac given to the electric valve 15am. On the other hand, the control signal input unit of the electric valve 15am is connected to the reflective distance sensor 11a via the relay 45 and the signal processing circuit 16a. Thereby, the detection result of the reflection type distance sensor 11a, that is, the detection signal Sad output from the reflection type distance sensor 11a is given to the control signal input unit of the electric valve 15am via the signal processing circuit 16a and the relay 45. The signal processing circuit 16a and the electric valve 15am constitute a flow rate control unit 7a that controls the flow rate of the coolant W flowing in the return path 5a in accordance with the detection signal Ssd output from the reflective distance sensor 11a.

  The relay 45 constitutes a coolant blocking means 17a and has a function of turning on / off a signal line between the signal processing circuit 16a and the electric valve 15am. Reference numeral 19 denotes a controller that controls the entire cooling system 1, and is connected to at least the relay 45, the liquid feed pump 18a, and the refrigeration cycle 34c described above. By configuring such a control system, the above-described control by the flow rate control unit 7a is performed without going through the controller 19, so that the control response and reliability can be improved by simplifying the flow rate control system. At the same time, there is an advantage that it can contribute to low cost improvement.

  Although one cooling circuit 3a has been described above, the other cooling circuits 3b and 3c are configured in the same manner as the cooling circuit 3a. In the cooling circuits 3b and 3c, 2b and 2c are tank members, 4b and 4c are supply paths, 5b and 5c are return paths, 6b and 6c are liquid level detection units, 7b and 7c are flow rate control units, and 15b and 15c. Is a control valve, 16b and 16c are signal processing circuits, 17b and 17c are coolant blocking means, and 20b and 20c are backflow prevention valves.

  Next, operation | movement of the cooling system 1 which concerns on this embodiment is demonstrated with reference to each figure including the flowchart shown to FIG.7 and FIG.8.

  First, a normal cooling operation will be described. The cooling circuits 3a, 3b, and 3c are mainly described only for the cooling circuit 3a, but the other cooling circuits 3b and 3c basically perform the same operation as the cooling circuit 3a.

  First, by the operation of the liquid feed pump 18a, the coolant W accommodated in the tank member 2a is fed in the direction of the arrow Fs through the supply path 4a. At this time, the coolant W is cooled to the target temperature in the cooling unit 34. That is, the refrigerant and the coolant W cooled by the refrigeration cycle 34c are heat-exchanged in the heat exchanger 34m, and the coolant W is cooled. The coolant W sent through the supply path 4a merges with the coolant W sent through the supply paths 4b and 4c of the other cooling circuits 3b and 3c, and then supplied to the cooled portion M. In this case, since the backflow prevention valves 20a, 320b, and 20c are connected to the supply paths 4a, 4b, and 4c, respectively, even when the three supply paths 4a are joined, the supply paths 4a. Backflow to the side is prevented, and interference between the cooling circuits 3a is prevented. On the other hand, the coolant W supplied to the cooled portion M passes through the inside of the cooled portion M and undergoes heat exchange, and the heat-exchanged coolant W is sent out to the return path 5a. Then, a basic cooling operation is performed in which the liquid is sent through the return path 5a in the direction of the arrow Fr and returned to the tank member 2a.

  By the way, when the three cooling circuits 3a, 3b, and 3c are continued in the state of the basic cooling operation described above, the following problems occur. That is, since the three cooling circuits 3a, 3b, 3c are not connected in exactly the same state, for example, the return path 5a of the cooling circuit 3a is shorter than the return paths 5b of the other cooling circuits 3b. For example, when the resistance to the water flow is relatively small, the flow rate of the coolant W returned to the tank member 2a is relatively large. As a result, there arises a problem that the coolant W in the tank member 2a increases with time. For this reason, in the cooling system 1 according to the present embodiment, each cooling circuit 3a, 3b, 3c has a flow rate control system with independent minor loops including liquid level detection units 6a, 6b, 6c and flow rate control units 7a, 7b, 7c. To solve this problem.

  Hereinafter, the operation of the flow rate control system including the liquid level detection unit 6a and the flow rate control unit 7a will be described with reference to the flowchart shown in FIG.

  First, the height Hw of the liquid level Wf of the coolant W accommodated in the tank member 2a is detected by the reflective distance sensor 11a constituting the liquid level detection unit 6a, and the size corresponding to the detected height Hw. Detection signal Sad is output (step S1). The detection signal Sad is applied to the signal processing circuit 16a and converted into a control signal Sac by signal processing including amplification processing (step S2).

  On the other hand, the control signal Sac is applied to the control signal input portion of the electric valve 15am via the relay 45. In this case, if the height Hw of the coolant W in the tank member 2a is set to a predetermined height in the initial state, the opening degree of the electric valve 15am is set (controlled) corresponding to the set height. Therefore, this state (opening degree) is maintained unless the height Hw of the coolant W varies (steps S3, S4, S5).

  On the other hand, the case where the height Hw of the coolant W accommodated in the tank member 2a becomes high for some reason is assumed (step S3). In this case, since the detection signal Sad is reduced, the opening degree of the electric valve 15am is controlled to be reduced, and control for reducing the flow rate of the coolant W flowing through the return path 5a is performed (step S6). As a result, the height Hw of the coolant W accommodated in the tank member 2a is returned to the initial state. Similarly, it is assumed that the height Hw of the coolant W accommodated in the tank member 2a is lowered for some reason (step S4). In this case, since the detection signal Sad is increased, the opening degree of the electric valve 15am is controlled to be increased, and control for increasing the flow rate of the coolant W flowing through the return path 5a is performed (step S7). As a result, the height Hw of the coolant W accommodated in the tank member 2a is returned to the initial state. Such flow rate control is performed independently for each control circuit 3a, 3b, 3c, and the coolant W contained in each tank member 2a, 2b, 2c is always at the initial height Hw. Maintained. The above control is continuously performed during the operation of the cooling system 1 (step S8).

  Therefore, according to the cooling system 1 according to the present embodiment, the storage tank unit 2 is configured by a plurality of tank members 2a ... corresponding to the number of the cooling circuits 3a ..., and each tank member 2a ... is provided with a plurality of cooling circuits 3a. The liquid level detectors 6a for detecting the height Hw of the liquid level Wf of the cooling liquid W contained in the tank members 2a, and the detection results of the liquid level detectors 6a. Since the flow rate control unit 7a for controlling the flow rate of the coolant W flowing through the corresponding return path 5a or the supply path 4a is provided, it is possible to easily cope with even when the cooling system 1 is changed. Can do. In particular, the old storage tank section becomes unnecessary or it becomes unnecessary to prepare a newly designed storage tank section, so that waste of materials can be avoided and the overall cost can be reduced. Moreover, since the cooling liquid W ... cooled for each of the cooling circuits 3a ... can be supplied, variation (offset) of the cooling (cooling load) for each cooling circuit 3a ... can be suppressed. Therefore, the cooling efficiency of the entire cooling system 1 can be improved and the cooling temperature can be stabilized, and the durability of the cooling system 1 can be improved.

  On the other hand, in the cooling system 1 according to this embodiment, since the flow rate control of the return path 5a ... is performed using the electric valves 15am ... (control valves 15a ...), the electric power is actually supplied after the control signal Sac ... is applied. Until the opening of the valve 15am is set, a temporal response delay occurs. Further, when the operation of the cooling system 1 is stopped, control for fully closing the electric valves 15am is performed from the viewpoint of safety or the like. Therefore, since the temporal response delay of the electric valves 15am is a problem, the cooling system 1 according to the present embodiment performs control to solve this problem. Hereinafter, this control operation will be described with reference to the flowchart shown in FIG.

  A case is assumed where the operation of the cooling system 1 in the stopped state is started. In the stopped state of the cooling system 1, the liquid feed pump 18a is stopped, and the relay 45, which is the coolant blocking means 17a, is OFF. In this state, an operation switch (not shown) is turned on (step S11). When the operation switch is turned on, the controller 19 turns on the relay 45. As a result, since the control signal Sac is applied to the electric valve 15am, the electric valve 15am performs an operation of opening from fully closed to an opening corresponding to the control signal Sac (step S12). On the other hand, when the operation switch is turned on, the controller 19 measures time for a predetermined time Tf set in advance (step S13). The set time Tf is set to a time corresponding to the response delay of the electric valve 15am (in the example, around 10 seconds). Then, when the time count for the set time Tf is up, control is performed to turn on the liquid feed pump 18a (steps S14 and S15). Thereby, the liquid feeding pump 18a is started, and the normal cooling operation described above is performed (step S16). By performing such control, the response delay of the flow rate control system including the electric valve 15am can be offset, so that it is possible to prevent the liquid feed pump 18a from starting in a state where the shutoff with respect to the coolant W is not completely released, Accordingly, it is possible to avoid the problem that the coolant W in the tank member 2a is unnecessarily reduced.

  On the other hand, to stop the operation of the cooling system 1, the operation switch is turned OFF (step S17). The controller 19 turns off the relay 45 by turning off the operation switch. As a result, since the signal line between the signal processing circuit 16a and the electric valve 15am is cut off, the control signal Sac for the electric valve 15am becomes a zero signal, and the electric valve 15am performs an operation of fully closing from opening (step S18). . On the other hand, when the operation switch is turned OFF, the controller 19 measures time for a predetermined time Ts set in advance (step S19). The set time Ts is set to a time corresponding to the response delay of the electric valve 15am (in the example, around 10 seconds). Then, when the time count for the set time Ts is up, control is performed to turn off the liquid feed pump 18a (steps S20 and S21). Thereby, the liquid feeding pump 18a stops. By performing such control, the response delay of the flow rate control system including the electric valve 15am is offset, so that it is possible to prevent the liquid feed pump 18a from stopping when the coolant W is not completely shut off. Therefore, it is possible to avoid the problem that the coolant W in the tank member 2a increases unnecessarily.

  Furthermore, when the height Hw of the liquid level Wf is equal to or greater than the predetermined upper limit height He, the controller 19 turns off the relay 45 (coolant blocking means 17a) to turn off the coolant W flowing in the return path 5a. A control function is provided that cuts off over a predetermined set time Te. When the height Hw of the liquid level Wf is greater than or equal to the predetermined upper limit height He, the occurrence of a failure or the like can be considered. Therefore, by providing such a control function, the cooling system 1 can be quickly protected. Can do.

  Although the best embodiment has been described in detail above, the present invention is not limited to such an embodiment, and the gist of the present invention is not limited to the detailed configuration, shape, material, quantity, numerical value, technique, and the like. Any change, addition, or deletion can be made without departing from.

  For example, the liquid level detection unit 6a and the flow rate control unit 7a may be configured as in the modified example shown in FIG. 6, and the liquid level detection units 6a ... and the flow rate control unit 7a ... exhibit similar functions. Various other configurations can be applied. The modification shown in FIG. 6 uses three electrodes 52c, 52d, and 52u with different lengths supported by the support base 51 in the liquid level detection unit 6a. The support base 51 is supported by the shaft 53 and can be set in the vertical position. The flow rate control unit 7a includes a series circuit 56 of a throttle valve 54 and an electromagnetic switching valve 55 connected in the middle of the return path 5a, a throttle valve 57 connected in parallel to the series circuit 56, and an electromagnetic switching circuit connected in parallel to the series circuit 56. While using the valve 58, the signal processing circuit 59 which converts the detection signal Sad obtained from the liquid level detection part 6a into the control signal Sac is used. In this case, the throttle amount of the throttle valve 57 is set larger than the throttle amount of the throttle valve 54. As a result, the lower limit liquid level is detected by energization of the common electrode 52n and the first electrode 52d, and the upper limit liquid level is detected by energization of the common electrode 52n and the second electrode 52u. At the time (when only the lower limit liquid level is detected), the electromagnetic on-off valve 55 is controlled to open and the electromagnetic on-off valve 58 is controlled to close. Thereby, the coolant W flows through the parallel circuit of the throttle valve 54 and the throttle valve 57. On the other hand, when the liquid level Wf decreases and both the lower limit liquid level and the upper limit liquid level are not detected, the electromagnetic on-off valve 58 is controlled to be opened. Thereby, since the coolant W flows by bypassing the throttle valve 54 and the throttle valve 57, the flow rate of the coolant W in the return path 5a can be increased. Furthermore, when the liquid level Wf rises and the common electrode 52n and the second electrode 52u are energized (when both the lower limit liquid level and the upper limit liquid level are detected), both the electromagnetic on-off valves 55 and 58 are controlled to be closed. Thereby, since the coolant W flows only through the throttle valve 57, the flow rate of the coolant W in the return path 5a can be reduced.

  In addition, although the case where one controller 19 is provided for each cooling circuit 3a, 3b, 3c has been shown, it is also possible to incorporate a controller in each cooling circuit 3a, 3b, 3c if necessary. That is, one controller 19 can be replaced with three controllers. Moreover, although the ultrasonic sensor which consists of a transmission part and a receiving part was illustrated as the reflection type distance sensor 11a, the optical sensor provided with the light emission part and the light-receiving part may be sufficient. On the other hand, the flow rate of the coolant W flowing through the return path 5a is controlled by the control valve 15a, but the flow rate of the coolant W flowing through the supply path 4a may be controlled. Furthermore, the cooling system 1 according to the present invention can be used not only for cooling objects such as electrical equipment and machine tools, but also for various other cooling objects (cooled part M) that can be similarly cooled by the coolant W. .

1 is an overall circuit diagram of a cooling system according to the best embodiment of the present invention; Detailed circuit diagram of the cooling circuit in the cooling system, A partially broken side view including a partial extraction view of a tank member in the cooling circuit of the cooling system, Plan view of the tank member, An enlarged side sectional view of the vicinity of the reflective distance sensor attached to the tank member, The circuit diagram which shows the example of a change of the liquid level detector and flow control part with which the cooling circuit of the cooling system is provided, A flowchart for explaining a cooling operation of the cooling system; A flowchart for explaining the operation at the start and stop of the cooling system; Configuration diagram of a conventional cooling system,

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1: Cooling system, 2: Storage tank part, 2a: Tank member, 2b: Tank member, 2c: Tank member, 3a: Cooling circuit, 3b: Cooling circuit, 3c: Cooling circuit, 4a: Supply path, 4b: Supply path 4c: supply path, 5a: return path, 5b: return path, 5c: return path, 6a: liquid level detection unit, 6b: liquid level detection unit, 6c: liquid level detection unit, 7a: flow rate control unit, 7b: Flow control unit, 7c: Flow control unit, 11a ...: Reflective distance sensor, 12a ...: Wave suppression plate, 13a ...: Support plate, 14a ...: Blower, 15a ...: Control valve, 16a ...: Signal processing circuit, 17a ...: Coolant blocking means, 18a ...: Liquid feed pump, 19: Controller, 20a: Backflow prevention valve, 20b: Backflow prevention valve, 20c: Backflow prevention valve, W: Coolant, Wf: Liquid level, Hw: Liquid level Height, M: part to be cooled, Sad ...: detection signal

Claims (10)

  In a cooling system comprising a plurality of cooling circuits that circulate cooling liquid stored in a storage tank unit to a predetermined cooled part and perform cooling, the storage tank unit is provided by a plurality of tank members corresponding to the number of cooling circuits. In addition, each tank member is built in a plurality of cooling circuits, and a supply path through which the cooling liquid is supplied from each cooling circuit and a return path through which the cooling liquid is returned to each cooling circuit are joined to each other. The return path or the supply path corresponding to the detection result of the liquid level detection unit and each liquid level detection unit connected to the cooling unit and detecting the height of the liquid level of the coolant stored in each tank member A cooling system comprising a flow rate control unit for controlling the flow rate of the coolant flowing through.   The said liquid level detection part is installed above the cooling liquid accommodated in the said tank member, The reflection type distance sensor which detects the height of the said liquid level by non-contact is used. Cooling system.   The cooling system according to claim 2, wherein the tank member includes a wave suppression plate that suppresses the wave of the liquid level detected by the reflective distance sensor.   4. The cooling system according to claim 3, wherein the wave suppression plate is formed of a heat conductive material and is also used as a support plate that supports the reflective distance sensor.   5. The cooling system according to claim 2, further comprising a blower that blows air to the reflective distance sensor to prevent condensation of the reflective distance sensor.   The flow rate control unit includes a control valve that controls the flow rate of the coolant flowing in the return path or the supply path, and a signal processing circuit that processes a detection signal obtained from the liquid level detection unit and supplies the detection signal to the control valve. The cooling system according to claim 1, further comprising a cooling system.   Provided is a coolant shut-off means for shutting off the coolant flowing in the return path or the supply path, and if the coolant is shut off by the coolant shut-off means, a feed built in the cooling circuit after a predetermined set time has elapsed. The cooling system according to claim 1, further comprising a controller having a control function for stopping the liquid pump.   8. The cooling system according to claim 7, wherein the controller has a control function of starting the liquid feeding pump after a predetermined set time has elapsed if the cooling liquid blocking by the cooling liquid blocking means is released. .   The controller has a control function for shutting off the coolant flowing in the return path or the supply path over a predetermined set time by the coolant shut-off means when the height of the liquid level is not less than a predetermined upper limit height. The cooling system according to claim 7, wherein the cooling system is provided.   The cooling system according to claim 1, wherein a backflow prevention valve is connected to the supply path.

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