JP2009108841A - Water pump control system and water pump control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent cavitation by increasing circulation water quantity according to a predetermined temperature rise of water near a preheater. <P>SOLUTION: In this water pump control system, temperature of cooling water near the preheater 23 heating cooling water passing through the same by circulated by a rear water pump 22 is detected, and a control part 30 controls the rear water pump 22 to increase circulation water quantity in a second circulation system 20 when detected cooling water temperature gets higher than predetermined temperature. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to control of a water pump that circulates water, and more particularly to a water pump control system and a water pump control method that are mounted in a heater system of a vehicle.

  Various methods have been devised and implemented as a heater system for heating the interior of a vehicle. For example, there is a so-called warm water type heater system using cooling water for cooling the engine. In general, an engine, which is an internal combustion engine mounted on a vehicle, includes a cooling mechanism that cools cooling water by circulating it with a water pump in order to burn fuel inside (for example, Patent Document 1).

The hot water heater system is configured to warm the interior of the vehicle by using the amount of heat of the cooling water provided by heat exchange between the cooling water circulated by the water pump mounted on the engine and the engine in this way. It has become.
Japanese Utility Model Publication No. 60-26231

  However, in buses and the like used for commercial purposes, there is a strong demand for improving the fuel efficiency of the engine, and therefore, an engine having the best fuel efficiency is being installed. As described above, since the amount of heat given to the cooling water by heat exchange with the engine with improved fuel efficiency is reduced, there is a possibility that the entire interior of the vehicle cannot be sufficiently heated by the conventional warm water heater system. There was a problem.

  In order to solve such a problem, a method has been devised in which a preheater is provided and the cooling water is heated by heat exchange using the preheater. However, when such a preheater is provided, cavitation occurs due to boiling of the cooling water by the preheater, and there is a possibility that the blades of the water pump are damaged by air bubbles collected in the water pump mounted on the engine. There is a problem.

  Then, this invention is proposed in view of the above-mentioned situation, and it aims at providing the water pump control system and water pump control method which can prevent generation | occurrence | production of cavitation.

  The present invention detects the water temperature in the vicinity of the preheater that heats the passing water by being circulated by the water pump, and in response to the detected water temperature in the vicinity of the preheater becoming higher than a predetermined temperature, The water pump is controlled so as to increase.

  According to the present invention, the occurrence of cavitation can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a heater system shown as an embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the heater system is mounted on a vehicle (not shown) and is configured to warm the interior of the vehicle using cooling water that is circulated to cool the engine 5 of the vehicle. The heater system is circulated by the engine circulating water pump 6 of the engine 5 as well as the first circulation system 10 that warms the front side (driver's seat) in the vehicle by the cooling water circulated by the engine built water pump 6 of the engine 5. A second circulation system 20 that warms the rear side of the vehicle (passenger seats other than the driver's seat) with cooling water, a control unit 30, and an operation unit 31 that is mainly operated by a user such as a vehicle driver. Yes.

  The engine built-in water pump 6 rotates cooling blades in both the first circulation system 10 and the second circulation system 20 by rotating blades (not shown) in conjunction with the engine 5.

  A vehicle (not shown) on which this heater system is mounted is assumed to be a medium-sized bus, for example, but the present invention is not limited to this, and a vehicle heater that requires a pre-heater. Can be applied to the system.

  The first circulation system 10 includes a front heater 11 and a front water pump 12.

  The front heater 11 is provided on a cooling water circulation line in the first circulation system 10, electrically heats the passing cooling water, and heats the air around the front heater 11 with the heated cooling water. Warm by replacement. The front heater 11 is provided with a fan (not shown), and warms the front side in the vehicle by sending out the warmed ambient air.

  The front water pump 12 is an electric water pump and circulates cooling water through the first circulation system 10. The front water pump 12 is installed at the rear stage of the front heater 11 and supplies the cooling water heated by the front heater 11 to the water pump 6 with a built-in engine.

  The second circulation system 20 includes rear heaters 21 </ b> A and 21 </ b> B and a rear water pump 22.

  The rear heaters 21A and 21B are provided on the cooling water circulation line in the second circulation system 20 so as to be parallel to each other, and electrically heat the cooling water passing therethrough so that the air around the rear heaters 21A and 21B is Warm by heat exchange with heated cooling water. Each of the rear heaters 21A and 21B is provided with a fan (not shown), and warms the rear side in the vehicle by sending out the warmed ambient air.

  The second circulation system 20 is provided with two rear heaters 21A and 21B as heaters for heating the cooling water on the assumption that it is necessary to warm a wide range as compared with the first circulation system 10. Depending on the situation, the number may be one or may be further increased.

  The rear water pump 22 is an electric water pump and circulates cooling water through the second circulation system 20. The rear water pump 22 is installed in front of the rear heaters 21A and 21B, and distributes the cooling water supplied from the engine built-in water pump 6 to the rear heaters 21A and 21B.

  The rear water pump 22 has a built-in front heater (not shown). Here, the preheater 23 built in the rear water pump 22 will be described with reference to FIG.

  As shown in FIG. 2, the preheater 23 includes an inner pipe 23 </ b> A made of a hollow metal member and an inner pipe 23 so as to form a gap 24 that is larger than the diameter of the inner pipe 23 </ b> A and allows cooling water to pass through. It consists of an outer pipe 23B arranged for 23A. A gas burner 23G is provided inside the inner pipe 23A, and the cooling water passing through the gap 24 can be indirectly heated by heating the inner pipe 23A with the gas burner 23G.

  Thereby, since the cooling water can be heated by the pre-heater 23 in the front stage of the rear heaters 21A and 21B that electrically heat the cooling water passing therethrough, in the second circulation system 20 that needs to be heated over a wide range, The cooling water can be heated quickly and reliably to the temperature of

  As shown in FIG. 2, a temperature detection sensor 25 that detects the surface temperature of the surface 23 a is provided on the surface 23 a that is the surface of the inner pipe 23 </ b> A of the preheater 23 on the gap 24 side. The surface temperature of the surface 23 a detected by the temperature detection sensor 25 is output to the control unit 30 and recognized as the temperature of the cooling water near the preheater 23.

  As described above, the temperature of the cooling water in the vicinity of the preheater 23 can be easily detected by using the temperature detection sensor 25. In addition, since the temperature rise of the surface 23a of the inner pipe 23A is faster than the temperature of the cooling water actually rises, the control process by the control unit 30 for preventing cavitation occurring in the preheater 23 described later is quickly performed. Can be migrated to.

  The control unit 30 controls the first circulatory system 10 and the second circulatory system 20 in an integrated manner. Specifically, the control unit 30 controls the front water pump 12 of the first circulation system 10 and the rear water pump 22 of the second circulation system 20 independently, and circulates the cooling water to be circulated in each circulation system. Adjust.

  The operation unit 31 includes a switch for inputting whether the front heater 11, the rear heaters 21A and 21B, and the preheater 23 are turned on or off. An operation request from the operation unit 31 is input to the control unit 30, and the control unit 30 performs on / off control of the front heater 11, the rear heaters 21 </ b> A and 21 </ b> B, and the preheater 23.

  The controller 30 mainly controls the amount of circulating water in the second circulation system 20 to prevent cavitation generated by the pre-heater 23, and improves the heating performance according to the heating requirements in the vehicle in the entire heater system. The optimal circulating water amount control process for the purpose is executed.

  First, the control processing operation of the circulating water amount in the second circulation system 20 for preventing the cavitation generated by the preheater 23 by the control unit 30 will be described using the flowchart shown in FIG.

  In step S <b> 1, the control unit 30 determines whether or not there has been a request from the operation unit 31 to turn on the preheater 23. When there is a request to turn on the preheater 23, the control unit 30 proceeds to step S2, while when there is no request, the control unit 30 proceeds to step S9.

In step S2, the control unit 30 determines whether or not the surface temperature _Tsurface ° C of the surface 23a of the inner pipe 23A detected by the temperature detection sensor 25 is higher than a predetermined temperature T ° C ( _Tsurface > T). . When the control section 30 was T _Surface> T, while proceeding to step S3, if not a T _Surface> T, the process proceeds to step S4.

  In step S3, the control unit 30 controls the front water pump 12 to be in an off state and controls the rear water pump 22 to be in an on state.

  Thus, since the amount of circulating water of the cooling water in the first circulation system 10 is reduced by turning off the front water pump 12, the reduced amount becomes an increase in the second circulation system 20, and the rear water pump 22 is reduced. The circulating water amount of the cooling water in the second circulation system 20 in which is turned on can be increased. Thereby, since the excess heat quantity in the surface 23a vicinity of the inner pipe 23A which is a heat exchange location with the cooling water of the preheater 23 can be given to the increased cooling water, boiling of the cooling water can be suppressed. . Therefore, since cavitation generated in the preheater 23 can be prevented, damage to the blades of the engine built-in water pump 6 of the engine 5 can be avoided.

  In order to prevent cavitation of the preheater 23, the amount of circulating water in the second circulation system 20 only needs to be increased. Therefore, the control unit 30 not only completely stops the front water pump 12, but also the first circulation system 10 The driving of the front water pump 12 and the rear water pump 22 may be controlled so as to reduce the amount of circulating water.

  In step S <b> 4, the control unit 30 determines whether or not there is a request from the operation unit 31 to turn on the front heater 11. If there is a request to turn on the front heater 11, the control unit 30 proceeds to step S5. If there is no request, the control unit 30 proceeds to step S8.

  In step S5, the control unit 30 determines whether or not there is a request from the operation unit 31 to turn on the rear heaters 21A and 21B. When there is a request to turn on the rear heaters 21A and 21B, the control unit 30 proceeds to step S6. On the other hand, when there is no request, the control unit 30 proceeds to step S7.

  In step S6, the control unit 30 drives the front water pump 12 and the rear water pump 22, respectively.

  In step S <b> 7, the control unit 30 drives the front water pump 12. At this time, in the second circulation system 20, the cooling water is circulated only by the engine built-in water pump 6 of the engine 5.

  In step S <b> 8, the control unit 30 drives the rear water pump 22. At this time, in the first circulation system 10, the cooling water is circulated only by the engine built-in water pump 6 of the engine 5.

  In step S <b> 9, the control unit 30 determines whether or not there is a request from the operation unit 31 to turn on the front heater 11. If there is a request to turn on the front heater 11, the control unit 30 proceeds to step S10. If there is no request, the control unit 30 proceeds to step S13.

  In step S10, the control unit 30 determines whether or not there is a request from the operation unit 31 to turn on the rear heaters 21A and 21B. If there is a request to turn on the rear heaters 21A and 21B, the control unit 30 proceeds to step S11. If there is no request, the control unit 30 proceeds to step S12.

  In step S11, the control unit 30 drives the front water pump 12 and the rear water pump 22, respectively.

  In step S12, the control unit 30 drives the front water pump 12. At this time, in the second circulation system 20, the cooling water is circulated only by the engine built-in water pump 6 of the engine 5.

  In step S <b> 13, the control unit 30 determines whether there is a request from the operation unit 31 to turn on the rear heaters 21 </ b> A and 21 </ b> B. If there is a request to turn on the rear heaters 21A and 21B, the control unit 30 proceeds to step S14. If there is no request, the control unit 30 proceeds to step S15.

  In step S <b> 14, the control unit 30 drives the rear water pump 22. At this time, in the first circulation system 10, the cooling water is circulated only by the engine built-in water pump 6 of the engine 5.

  In step S15, the control unit 30 does not drive either the front water pump 12 or the rear water pump 22. At this time, in the first circulation system 10 and the second circulation system 20, cooling water is circulated only by the engine built-in water pump 6 of the engine 5, respectively.

In this way, when the surface temperature _Tsurface ° C of the surface 23a of the inner pipe 23A detected by the temperature detection sensor 25 is higher than the predetermined temperature T ° C ( _Tsurface > T), the control unit 30 The driving of the front water pump 12 and the rear water pump 22 is controlled so that the amount of circulating water in one circulation system 10 decreases. Thereby, since the circulating water amount of the cooling water of the second circulation system 20 increases, the excess heat amount in the vicinity of the surface 23a of the inner pipe 23A, which is a heat exchange portion with the cooling water of the preheater 23, is increased to the increased cooling water. By giving, the boiling of cooling water can be suppressed and cavitation generated in the preheater 23 can be prevented. Therefore, damage to the blades of the engine built-in water pump 6 of the engine 5 caused by cavitation can be avoided.

  Next, an optimal control process of the circulating water amount according to the heating requirement in the vehicle in the entire heater system by the control unit 30 will be described.

  The heater system shown in FIG. 1 controls the front water pump 12 and the rear water pump 22 by the control unit 30, so that the heating performance according to the heating requirement in the vehicle that changes due to the influence of the number of passengers of the vehicle and the external environment. Execute the optimal circulating water volume control process for the purpose of improvement. Basically, in the heater system, the controller 30 controls the front so as to improve the heating performance of one of the first circulation system 10 and the second circulation system 20 according to the heating requirement as described above. One of the water pump 12 and the rear water pump 22 is controlled.

<1> When the heating performance of the first circulation system 10 is improved In order to improve the heating performance of the first circulation system 10, the circulating water amount of the cooling water in the first circulation system 10 may be increased. Since the circulating water amount of the cooling water circulated in the entire heater system, that is, the first circulating system 10 and the second circulating system 20 is constant, only the front water pump 12 is used to increase the circulating water amount of the first circulating system 10. And driving of the rear water pump 22 may be stopped.

  For example, when only the driver is in the vehicle, there is no need to warm the rear side. That is, as a heating requirement, only the front side needs to be heated. In such a case, the control unit 30 controls to drive only the front water pump 12 of the first circulation system 10 and stop driving the rear water pump 22 of the second circulation system 20. Thereby, when the rear water pump 22 is driven, the circulating water amount circulating through the second circulation system 20 can be reduced to the first circulation system 10, so that the circulating water amount in the first circulation system 10 can be reduced. Accordingly, the heating performance of the first circulation system 10 responsible for heating the front side of the vehicle can be improved.

  At the normal time when both the front water pump 12 and the rear water pump 22 are driven, the amount of circulating water in the first circulation system 10 is expressed by the following equation (1).

(Normal time)
Circulating water volume of the first circulation system 10:
Circulating water volume by front water pump 12 + (circulating water volume by engine built-in water pump 6-rear circulating water volume)

  On the other hand, when the heating performance is improved such that the front water pump 12 is driven and the rear water pump 22 is stopped, the amount of circulating water in the first circulation system 10 is expressed by the following equation (2).

(When heating performance is improved)
Circulating water volume of the first circulation system 10:
Circulating water amount by front water pump 12 + (circulating water amount by engine built-in water pump 6 -rear side circulating water amount x A) (2) where A is A <1

  Since the rear water pump 22 is stopped in this manner, the amount of circulating water in the first circulation system 10 that drives the front water pump 12 is increased by the amount of reduction in the amount of circulating water in the second circulation system 20. Depending on the heating requirement, the heating performance of the first circulation system 10 is improved. Further, in order to improve the heating performance of the first circulation system 10, it is only necessary to increase the amount of circulating water in the first circulation system 10, so that the control unit 30 not only completely stops the rear water pump 22 but also the first circulation system 10. (2) The driving of the rear water pump 22 is controlled so as to reduce the amount of circulating water in the circulation system 20.

  That is, the control unit 30 controls the front water pump 12 and the rear water pump 22 so as to reduce the amount of circulating water in the second circulation system 20, so that the heating performance of the first circulation system 10 according to the heating requirement. Can be improved.

<2> When the heating performance of the second circulation system 20 is improved In order to improve the heating performance of the second circulation system 20, the circulating water amount of the cooling water in the second circulation system 20 may be increased. As described above, since the circulating water amount of the cooling water circulated in the entire heater system, that is, the first circulating system 10 and the second circulating system 20 is constant, in order to increase the circulating water amount of the second circulating system 20, It is only necessary to drive only the rear water pump 22 and stop driving the front water pump 12.

  For example, in a driver's seat that is covered with window glass and is more susceptible to solar radiation than passenger seats other than the driver's seat, if only the driver does not need heating due to the effects of solar radiation or driving action, the front side There is no need to warm up. That is, as a heating requirement, only the rear side needs to be heated. In such a case, the control unit 30 controls to drive only the rear water pump 22 of the second circulation system 20 and stop driving the front water pump 12 of the first circulation system 10. Thereby, when the front water pump 12 is driven, the circulating water amount circulating through the first circulating system 10 can be reduced to the second circulating system 20, so the circulating water amount in the second circulating system 20 Accordingly, the heating performance of the second circulation system 20 responsible for heating the rear side of the vehicle can be improved.

  During normal operation when both the front water pump 12 and the rear water pump 22 are driven, the amount of circulating water in the second circulation system 20 is expressed by the following equation (3).

(Normal time)
Circulating water volume of the second circulation system 20:
Circulating water volume by the rear water pump 22 + (Circulating water volume by the engine built-in water pump 6-Front circulating water volume)

  On the other hand, when the heating performance is improved such that the rear water pump 22 is driven and the front water pump 12 is stopped, the amount of circulating water in the second circulation system 20 is expressed by the following equation (4).

(When heating performance is improved)
Circulating water volume of the second circulation system 20:
Circulating water amount by the rear water pump 22+ (circulating water amount by the engine built-in water pump 6−front-side circulating water amount × B) (4) where B is B <1

  As described above, since the front water pump 12 is stopped, the amount of circulating water in the second circulation system 20 that drives the rear water pump 22 increases as much as the amount of circulating water in the first circulation system 10 decreases. Depending on the heating requirements, the heating performance of the second circulation system 20 is improved. Further, in order to improve the heating performance of the second circulation system 20, the amount of circulating water in the second circulation system 20 only needs to be increased. Therefore, the control unit 30 not only completely stops the front water pump 12, The driving of the front water pump 12 is controlled so as to reduce the amount of circulating water in one circulation system 10.

  That is, the control unit 30 controls the front water pump 12 and the rear water pump 22 so as to reduce the amount of circulating water in the first circulation system 10, thereby heating the second circulation system 20 according to the heating requirement. Performance can be improved.

  Moreover, in the heater system shown as embodiment of this invention mentioned above, although the case where the pre-heater 23 is arrange | positioned to the 2nd circulation system 20 is demonstrated, this invention is not limited to this, Two In a heater system provided with a circulation system, when a preheater is arranged in at least one circulation system, it can apply to all.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

It is a figure for demonstrating the structure of the heater system shown as embodiment of this invention. It is a figure for demonstrating the structure of the pre-heater provided in the 2nd circulation system of the said heater system. It is a flowchart for demonstrating control processing operation | movement of the circulating water amount for preventing the cavitation generate | occur | produced by the said preheater.

Explanation of symbols

DESCRIPTION OF SYMBOLS 5 Engine 6 Engine built-in water pump 10 1st circulation system 11 Front heater 12 Front water pump 20 2nd circulation system 21A Rear heater 21B Rear heater 22 Rear water pump 23 Preheater 23A Inner pipe 25 Temperature detection sensor 30 Control part

Claims (5)

A water pump that circulates water,
A preheater that heats water passing by being circulated by the water pump;
Water temperature detecting means for detecting the water temperature in the vicinity of the preheater;
Water pump control means for controlling the driving of the water pump,
The water pump control means controls the water pump to increase the amount of circulating water in response to the water temperature in the vicinity of the preheater detected by the water temperature detecting means becoming higher than a predetermined temperature. Water pump control system. A first circulation system having a first water pump that circulates water, and a first heater that heats water passing by being circulated by the first water pump;
A second water pump that circulates water, and a second circulation system that has a second heater that heats the water that passes by being circulated by the second water pump,
The preheater is disposed in at least one of the first circulation system and the second circulation system;
In the water pump control means, the water temperature in the vicinity of the preheater of either the first circulation system or the second circulation system detected by the water temperature detection means is higher than a predetermined temperature. In response, the water pump control system according to claim 1, wherein the first water pump and the second water pump are controlled so as to reduce the amount of circulating water in the other circulation system. The water pump control means controls to stop the second water pump when the water temperature in the vicinity of the pre-heater of the first circulation system detected by the water temperature detection means is higher than a predetermined temperature;
3. The control according to claim 2, wherein when the water temperature in the vicinity of the pre-heater of the second circulation system detected by the water temperature detection means becomes higher than a predetermined temperature, the first water pump is controlled to stop. Water pump control system. The pre-heater indirectly heats the water passing through the outside of the metal member by heating the hollow metal member with a burner from the inside,
Surface temperature detecting means for detecting the surface temperature of the metal member;
The water pump according to any one of claims 1 to 3, wherein the water temperature detection means uses the surface temperature of the metal member detected by the surface temperature detection means as a water temperature in the vicinity of the preheater. Control system. A water temperature detection step for detecting the water temperature in the vicinity of the pre-heater that heats the water passing by being circulated by the water pump;
A water pump control step for controlling the driving of the water pump,
The water pump control step controls the water pump so as to increase the amount of circulating water in response to the water temperature in the vicinity of the preheater detected by the water temperature detection step becoming higher than a predetermined temperature. To control the water pump.

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