JP2004360635A - Cooling water temperature control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling water temperature control device capable of efficiently and rapidly controlling the temperature of cooling water. <P>SOLUTION: This cooling water temperature control device controlling the temperature of the cooling water according to the operating state of the engine of a vehicle comprises an engine water temperature detection means 26 detecting the cooling water temperature T<SB>A</SB>of the engine 1, a heat storage device 23 connected to the engine 1 and storing cooling water while insulating after the engine 1 is cooled, a heat storage device water temperature detection means 24 detecting the cooling water temperature T<SB>B</SB>of the heat storage device 23, and a control means 11 supplying the cooling water of the heat storage device 23 to the engine 1 when the engine 1 is in a low load state and the heat storage device water temperature T<SB>B</SB>detected by the heat storage device water temperature detection means 24 is higher than the engine water temperature T<SB>A</SB>detected by the engine water temperature detection means 26 and holding the cooling water of the heat storage device 23 without supplying to the engine 1 when the heat storage device water temperature T<SB>B</SB>is lower than the engine water temperature T<SB>A</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling water temperature control device suitable for use in an engine mounted on an automobile.
[0002]
[Prior art]
The engine is generally provided with a thermostat in order to keep the temperature of the cooling water at an appropriate temperature (for example, around 80 ° C.). The valve element of such a thermostat is opened when the cooling water temperature becomes higher than a predetermined temperature, so that cold cooling water from the radiator is supplied to the engine.
[0003]
By the way, in addition to keeping the cooling water temperature constant, there is a demand to actively change the cooling water temperature according to the load of the engine. This is because when the engine is operating at a low load, the engine temperature is actively raised to reduce friction loss and improve fuel efficiency, while the engine is operating at a high load. Are based on a demand that the engine temperature be actively lowered to increase the intake air density to increase the output and suppress knocking.
[0004]
However, according to the above-described general thermostat, even when the engine load is increased, if the cooling water temperature is equal to or lower than the predetermined temperature, the cooling water from the radiator is not supplied to the engine, so that the engine temperature increases. Resulting in. On the other hand, if the cooling water temperature is equal to or higher than the predetermined temperature, the cooling water from the radiator is supplied to the engine even when the engine load decreases, and the engine temperature decreases.
[0005]
That is, according to the above-described general thermostat, although the purpose of keeping the cooling water temperature constant can be achieved, the purpose of controlling the cooling water temperature according to the load of the engine cannot be achieved.
Therefore, as an example of a technique for controlling the cooling water temperature with respect to the engine load, a technique as disclosed in Patent Document 1 below is disclosed. In this technology, it is described that an engine and a heat storage device are connected by a refrigerant pipe, cooling water is circulated between the refrigerant pipe and the heat storage device, and the engine is warmed by the cooling water kept warm by the heat storage device. I have.
[0006]
[Patent Document 1]
JP-A-2002-195035
[Problems to be solved by the invention]
However, in the technique of Patent Document 1, when the load on the engine is small (partial load), the cooling water circulation to the regenerator is started, while when the engine load is large (full load), the cooling water is recirculated to the regenerator. Since the cooling water circulation is stopped, the cooling water of the regenerator is supplied to the engine even when the cooling water temperature of the regenerator is low at a partial load, for example. For this reason, there is a case where the engine temperature is lowered even though the engine temperature is desired to be raised.
[0008]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a cooling water temperature control device capable of efficiently and quickly adjusting a cooling water temperature.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a cooling water temperature control device for controlling a cooling water temperature in accordance with an engine operating state of a vehicle, wherein the engine water temperature detecting means for detecting a cooling water temperature of the engine; A regenerator which is connected and stores the cooling water after cooling the engine while keeping the temperature warm; a regenerator water temperature detecting means for detecting a cooling water temperature of the regenerator; and the regenerator water temperature detecting means when the engine is in a low load state. When the detected regenerator water temperature is higher than the engine water temperature detected by the engine water temperature detecting means, the cooling water of the regenerator is supplied to the engine, and even if the engine is in a low load state, the cooling water is supplied to the engine. When the regenerator water temperature is lower than the engine water temperature, control means is provided for holding the cooling water of the regenerator without supplying the cooling water to the engine.
[0010]
Thus, when the engine is in a low load state, if the temperature of the cooling water stored in the regenerator is higher than the cooling water of the engine, the cooling water of the regenerator is supplied to the engine to quickly raise the engine temperature. In addition, when the temperature of the cooling water stored in the regenerator is lower than the cooling water of the engine, the cooling water of the regenerator is not supplied to the engine, so that the temperature of the cooling water can be adjusted efficiently.
[0011]
Further, in the cooling water temperature control device according to the second aspect of the present invention, in the configuration according to the first aspect, when the regenerator water temperature is lower than the engine water temperature and the engine water temperature is equal to or higher than a predetermined temperature, The cooling water after cooling the engine is introduced into the regenerator.
Thereby, when the engine water temperature is lower than the regenerator water temperature and the engine water temperature is equal to or higher than the predetermined temperature, the cooling water after engine cooling is introduced into the regenerator to store the heat, and thereafter the engine temperature can be increased. In a favorable situation, the cooling water in the regenerator can be discharged to the engine, so that the temperature raising performance can be significantly improved.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a cooling water temperature control device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a schematic diagram showing the configuration, FIG. 2 is a time chart for explaining its operation, 3 to 5 are flowcharts showing the operation.
A cooling system 10 mainly composed of a water pump 4, a heater core 5, a radiator 6, and a thermostat (water temperature control valve) 7 is connected to a water-cooled engine (hereinafter simply referred to as an engine) 1 shown in FIG. _A water temperature sensor (engine water temperature detecting means) 26 for detecting the water temperature TA is additionally provided. Further, the water pump 4 is connected to the crankshaft 2 of the engine 1 via a belt 3, and the cooling water is circulated between the engine 1 and the cooling system 10 by the water pump 4. .
[0013]
Further, according to the thermostat 7 provided in the cooling system 10 is interposed between the first port 1a and the radiator 6 and the water pump 4 of the engine 1, the outlet water temperature (engine water temperature) of the engine 1 T _A Thus, the temperature sensing part (not shown) of the thermostat 7 expands and contracts. A valve (not shown) of the thermostat 7 is opened and closed according to the expansion and contraction of the temperature sensing portion.
[0014]
As a result, the thermostat 7 flows into the engine 1 again from the engine 1 via the radiator 6 and the cooling water (see arrows F ₄ and F _{6 in the} figure) that flows into the engine 1 again without passing through the radiator 6. The flow rate with the cooling water (arrows F ₅ and F _{6 in the} figure) can be adjusted. Further, the valve body of the thermostat 7 described above, not only to open and close in response to changes in the engine coolant temperature T _A as described above, is controlled so as to open and close by ECU (control means) 11 to be described later, so-called electrostatic control thermostat Has been applied.
[0015]
The radiator 6 cools the cooling water by radiating heat, and is interposed between the second port 1 b of the engine 1 and the thermostat 7. The heater core 5 has an input port 5a and an output port 5b. The input port 5a is connected to the third port 1c of the engine 1, and the output port 5b is connected to the water pump 4. Thus, the cooling water after cooling the engine 1 is supplied to the heater core 5 through the input port 5a, and functions as a heat source of a heater (not shown) by removing heat from the cooling water. The cooling water whose heat has been removed by the heater core 5 is returned to the engine 1 from the output port 5b via the water pump 4.
[0016]
Further, in the cooling water temperature control device according to the present embodiment, a regenerator 23 is provided in the cooling system 10 between the water channels 21 and 22 that bypass the heater core 5, the radiator 6, and the thermostat 7. so that the cooling water after cooling the engine 1 (see FIG arrow F ₂₎ is stored while being kept warm by. Furthermore, so that the provided with a water temperature sensor (heat accumulator water temperature detecting means) 24 can detect the coolant temperature T _B stored in the heat accumulator 23 in this regenerator 23.
[0017]
A regenerator valve 25 is interposed between the water channels 21 and 22 and the regenerator 23. The regenerator valve 25 controls the amount of cooling water flowing from the engine 1 to the regenerator 23 via the water passage 21 and controls the amount of cooling water discharged from the regenerator 23 to the engine 1 via the water passage 22 and the water pump 4. You can do it. The regenerator valve 25 is electrically connected to the ECU 11 described below, and the regenerator valve 25 is controlled by the ECU 11.
[0018]
The ECU 11 is electrically connected to the engine 1, the thermostat 7, and the regenerator valve 25, and includes a target water temperature setting unit 11a, an engine load determining unit 11b, a regenerator valve control unit 11c, and a thermostat control unit (not shown). It is configured.
The ECU 11 also includes an engine water temperature T _A detected by a water temperature sensor 26 attached to the engine 1, a water temperature T _B detected by a water temperature sensor 24 attached to the regenerator 23, and a rotation speed sensor (not shown). detected by the engine speed N _E, it adapted to receive various kinds of information such as the engine load L _D. Here, the engine load L _D, for example, is adapted to be set accelerator pedal depression amount and the like (accelerator opening) and an intake manifold pressure as a parameter.
[0019]
Among the above, the target water temperature setting means 11a is for setting the target water temperature T _T in response to engine load L _D, here is provided as a map. That is, the target water temperature setting means 11a, by applying the engine load L _D above, so that the target water temperature T _T is obtained. Further, the target water temperature T _T, while being set to be lower as the engine load increases, and is set to be higher as the engine load decreases. This is because, as described above in the section of the prior art, when the engine is operating at a low load, the engine temperature is positively increased to reduce friction loss and improve fuel efficiency, while improving the engine efficiency. When the engine is operated under a high load, the engine temperature is positively lowered to increase the intake air density to increase the output and to suppress knocking.
[0020]
The engine load determining means 11b determines whether the load on the engine 1 is high or low based on the accelerator pedal depression amount (accelerator opening).
Further, heat accumulator valve control means 11c is configured to control the heat accumulator valve 25 based on the target temperature T _T and regenerator temperature T _B which is set according to the coolant temperature T _A and the engine load L _D of the engine 1 It is.
[0021]
Then, the engine load _{L D} by the engine load determining means 11b described above is determined as the low load, by the regenerator valve control means _{11c, T} T> T _A, and provided that _T A _{<T B} is If it is determined that the cooling water has been filled, the regenerator valve 25 is opened to release the cooling water stored in the regenerator 23 to the engine 1, and the cooling water supplied to the engine 1 (in FIG. temperature rise control to raise quickly the temperature of the arrow reference F ₆₎ (details are adapted to perform the described later).
[0022]
On the other hand, when the engine load by the engine load determiner 11b along with is determined to be a high load, the engine coolant temperature T _A is the condition that is regenerator temperature T _B above is satisfied, the heat accumulator valve 25 releasing relatively cold cooling water to open the valve is stored in the heat accumulator 23 to the engine 1 to quickly reduce the temperature of the cooling water supplied to the engine 1 (see FIG arrow F ₆₎ Water temperature lowering control (which will be described in detail later) is executed.
[0023]
Further, the water temperature increase control, when the thermostat 7 is closed by the ECU11 thermostat control means (not shown), increase the engine coolant temperature T _A by blocking the inflow of cooling water from the radiator 6 to the engine 1 As a result, the temperature rise of the engine 1 is further promoted. On the other hand, in the above-mentioned water temperature reduction control, the thermostat 7 is opened by the thermostat control means, so that the cooling water from the radiator 6 is supplied to the engine 1 so that the engine 1 during high load operation is actively operated. It is designed to be cooled.
[0024]
Since the cooling water temperature control device of the present invention is configured as described above, its operation will be described below. First, as shown in the time chart of FIG. 2, when the engine load is low (see section A), T if _B> T _a, regenerator valve 25 is opened, the water temperature increase control is performed so that the engine coolant temperature T _{a =} target temperature T _T1 by the heat accumulator valve control means 11c.
[0025]
Thereafter, when the load on the engine 1 increases (see section B), if T _B > T _A , the regenerator valve 25 closes and the thermostat 7 opens, and the cooling water circulates while passing through the radiator 6. in order to lower the engine water temperature T _a by the water temperature reduction control described above is executed. At this time, the valve opening of the thermostat 7 is adjusted by the temperature sensing unit, the engine coolant temperature T _A is stabilized at the target temperature T _T2.
[0026]
Then, decrease the load of the engine 1 again (see section C), and the temperature T _A of the cooling water after cooling the engine below the temperature T _B of the cooling water that is stored in the heat accumulator 23 (ie, T and _B> the T _a), the high-temperature cooling water is stored in the heat accumulator 23 is supplied to the engine 1, the engine coolant temperature T _a is increased to the target temperature T _T1.
[0027]
Thus, even when the engine load is shifted from a high load to a low load, as shown by arrow D, can be raised rapidly engine water temperature T _A. Incidentally, the line shown in the drawing the chain line arrow E indicates the characteristics when raising the coolant temperature to the target temperature T _T1 by conventional cooling systems. That is, according to the invention of the present embodiment, it is possible to speed up the temperature rise of the engine for the time indicated by the arrow F.
[0028]
Next, the operation of the present invention according to the present embodiment will be described with reference to the flowchart shown in FIG. 3. First, the engine water temperature T _A , the regenerator water temperature T _B , the engine speed N _E , the engine load L _D, etc. Is read (step S11). Next, read on the basis of the engine load _{L D,} the target temperature setting means 11a of the ECU 11, the target temperature _{T T} is obtained (step S12).
[0029]
Then, the engine load L _D is either an a or a low load and high load is determined (step S13). That is, in this step S13, it is determined whether to execute the control for increasing the cooling water temperature for the engine 1 or the control for decreasing the cooling water temperature.
[0030]
If it is determined in step S13 that the engine 1 is operating under low load ("low load" route in the figure), the water temperature rise control set as a subroutine is executed in step S20. If it is determined that the engine 1 is operating under a high load ("high load" route in the figure), a water temperature reduction control for reducing the cooling water temperature set as a subroutine in step S30 is executed.
[0031]
Among them, the water temperature increase control, as shown in FIG. 4, first, whether or not the engine coolant temperature T _A is less than the target temperature T _T is determined (step S21). Here, if the engine coolant temperature T _A is equal to or greater than the target temperature T _T moves to (No route), the water temperature reduction control to be described later. This is intended to prevent the engine 1 from overheating. On the other hand, in step S21 described above, if the engine coolant temperature T _A is less than the target temperature T _T (Yes route), the thermostat (temperature control valve) 7 of the valve closed, cooled after cooling the engine 1 Water is supplied to the engine 1 again (step S22).
[0032]
Thereafter, in step S23, regenerator temperature T _B is equal to or higher than the engine coolant temperature T _A is determined. Here, (Yes route) in the case of the heat accumulator temperature T _B is determined to be higher than the engine coolant temperature T _A, regenerator cooling water engines in regenerator 23 by the valve 25 is opened 1 And the temperature of the engine 1 is promoted (step S27).
[0033]
On the other hand, in step S23 described above, if the heat accumulator temperature T _B is not determined to be higher than the engine coolant temperature T _A (i.e., if the engine coolant temperature T _A is the heat accumulator temperature T _B above) (No route ), further the engine coolant temperature _{T a} is determined whether a temperature higher than the predetermined temperature _{T C} (step S24). The predetermined temperature T _C is set to a temperature lower than the target water temperature T _T (for example, about 20 ° C.). In other words, the predetermined temperature T _C means that the cooling water below the water temperature T _C is stored in the regenerator 23. This is a temperature at which a sufficient heat storage effect cannot be obtained even if introduced inside.
[0034]
Then, in step S24, if the engine coolant temperature T _A is determined to be higher than the predetermined temperature T _C (Yes route), the heat accumulator valve 25 is opened, the cooling after cooling the engine 1 Water is introduced into the heat accumulator 23 and heat is stored in the heat accumulator 23. That is, even during the temperature increase control, when the engine coolant temperature T _A is higher than the regenerator temperature T is at _B or more and the predetermined temperature T _C, the cooling water after actively cooling the engine 1 Is introduced into the heat accumulator 23. As a result, when the engine 1 is stopped and then started again (particularly when the engine 1 is started in a cold state), the time required for raising the engine temperature can be significantly reduced.
[0035]
Further, in step S24 described above, the (No route) when the engine water temperature T _A is equal to or less than the predetermined temperature T _C, the heat accumulator valve 25 is closed, the cooling water after cooling the engine 1 Is supplied to the engine 1 again without being introduced into the regenerator 23. Thereby, the temperature rise of the engine 1 is prioritized over the heat storage of the regenerator 23, and the temperature rise of the engine 1 can be promoted.
[0036]
On the other hand, if the engine load L _D in step S13 of the operation flow described above shown in FIG. 3 is determined to be a high load, or the engine coolant temperature T _A is the target temperature in step S21 of the operation flow described above shown in FIG. 4 If it is determined that the T _T or more, the process proceeds to temperature reduction control shown in FIG. Hereinafter, the water temperature lowering control will be described. First, in step S31, the thermostat (water temperature control valve) 7 opens to supply the cooling water from the radiator 6 to the engine 1, thereby promoting the cooling of the engine 1. Thereafter, the cooling water temperature T _B in the heat storage device 23 detected by the water temperature sensor 24 provided in the heat accumulator 23, a coolant temperature T _A of the engine 1 detected by the temperature sensor 26 provided in the engine 1 is it is compared, whether a regenerator temperature _{T B>} engine coolant temperature _{T a} is determined (step S32).
[0037]
Here, if the direction of the heat accumulator temperature T _B is higher than the engine coolant temperature T _A (Yes route), the heat accumulator valve 25 is not opened, the cooling water stored in the heat accumulator 23 is discharged to the engine 1 Therefore, heat is not dissipated from the heat storage device 23 to the engine 1. Thereby, cooling of the engine 1 can be promoted.
On the other hand, if the heat accumulator temperature T _B is equal to or less than the engine coolant temperature T _A (No route), the heat accumulator valve 25 is opened, the heat storage in the cooling water after cooling the engine 1 is introduced into the regenerator 23 Heat is stored in the vessel 23. At this time, since the cooling water in the heat accumulator 23 is lower than the engine coolant temperature T _A is supplied to the engine 1, the engine 1 to enhance cooling.
[0038]
As described above, according to the present invention according to this embodiment, the engine coolant temperature T _A is measured by a water temperature sensor 26 which is attached to the engine 1 (engine water temperature detecting means), which is attached to the heat accumulator 23 water temperature sensor temperature T _B of the cooling water stored in the heat accumulator by (regenerator temperature detection means) 24 is measured. At this time, and the engine 1 is an in low-load operation, when the heat accumulator temperature T _B is higher than the engine coolant temperature T _A, while cooling water in the heat accumulator 23 is supplied to the engine, the heat accumulator water temperature when T _B is less than or equal to the engine coolant temperature T _a are in principle cooling water in the heat accumulator 23 is prevented being supplied to the engine.
[0039]
Thus, compared with the cooling water temperature T _A of the temperature T _B of the cooling water that is stored in the thermal storage unit 23 the engine 1, based on the comparison determination result, it can be quickly achieved an increase in water temperature, also Thus, the temperature rise of the engine 1 can be efficiently promoted.
Further, at the time of low load operation, the heat accumulator temperature T _B is equal to or less than the engine coolant temperature T _A, and, when the engine coolant temperature T _A is higher than the predetermined temperature T _C is the cooling water after cooling the engine 1 Since the heat is introduced into the heat accumulator 23 and heat is stored, the heat stored in the heat accumulator 23 (that is, the cooling water that has been kept warm) is used to increase the engine temperature (for example, when the engine is restarted). , It is possible to efficiently promote the temperature rise of the engine 1 and contribute to the improvement of the temperature rise performance.
[0040]
Furthermore, during high load operation or when the engine coolant temperature T _A even during low-load operation is determined to be equal to or greater than the target temperature T _T is fed coolant from the radiator 6 to the engine 1 and the engine 1 Cooling is promoted. At this time, if the regenerator water temperature T _B > the engine water temperature T _A , the regenerator valve 25 is kept closed and no heat is released from the regenerator 23 to the engine 1. Thereby, cooling of the engine 1 can be promoted. On the other hand, the heat accumulator when the water temperature T _B is equal to or less than the engine coolant temperature T _A is the heat accumulator valve 25 is opened, efficiently heat accumulator by introducing cooling water after cooling the engine 1 to the regenerator 23 The heat can be stored in the heat storage unit 23, and the cooling of the engine 1 can be promoted by supplying the relatively cold cooling water stored in the heat storage unit 23 to the engine 1.
[0041]
Note that the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the spirit of the present invention.
For example, you may comprise so that the valve opening degree of a heat storage valve can be changed suitably between 0-100%. As a result, the amount of water introduced or discharged into the regenerator can be accurately controlled, so that the temperature of the engine can be more finely controlled.
[0042]
Further, in the above-described embodiment, the case where the heat stored in the regenerator is applied to the engine has been described. In addition, for example, when the temperature of the cooling water in the regenerator is sufficiently high, the regenerator may be used. The cooling water can be supplied not only to the engine but also to the heater core, so that the temperature raising performance of the engine and the heater performance can be improved.
[0043]
【The invention's effect】
As described in detail above, according to the cooling water temperature control device of the present invention, the cooling water temperature can be adjusted efficiently and responsively. In other words, when the temperature of the cooling water stored in the regenerator is higher than the cooling water of the engine, the temperature of the engine is quickly raised by supplying the cooling water of the regenerator to the engine, and the cooling water stored in the regenerator is also increased. When the temperature of the water is lower than the cooling water of the engine, the cooling water of the regenerator is not supplied to the engine, so that the cooling water temperature can be adjusted efficiently.
[0044]
Further, when the engine water temperature is lower than the regenerator water temperature and the engine water temperature is equal to or higher than the predetermined temperature, it is preferable to introduce the cooling water after cooling the engine into the regenerator to store the heat, and thereafter increase the engine temperature. When a situation arises, the cooling water in the regenerator is discharged to the engine, so that the temperature raising performance of the engine can be greatly improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of a cooling water temperature control device according to an embodiment of the present invention.
FIG. 2 is a time chart schematically showing the operation of the cooling water temperature control device according to one embodiment of the present invention.
FIG. 3 is a flowchart schematically showing the operation of the cooling water temperature control device according to one embodiment of the present invention.
FIG. 4 is a flowchart schematically showing the operation of the cooling water temperature control device according to one embodiment of the present invention, and shows a subroutine water temperature increase control.
FIG. 5 is a flowchart schematically showing the operation of the cooling water temperature control device according to one embodiment of the present invention, and shows a subroutine water temperature lowering control.
[Explanation of symbols]
1 engine 11 ECU (control means)
11a Target water temperature setting means 11b Engine load determination means 11c Heat storage valve control means 23 Heat storage 24 Water temperature sensor (heat storage water temperature detection means)
26 Water temperature sensor (engine water temperature detection means)

Claims (2)

In a cooling water temperature control device that controls a cooling water temperature according to an engine operating state of a vehicle,
Engine water temperature detecting means for detecting a cooling water temperature of the engine;
A regenerator connected to the engine and storing the cooling water after cooling the engine while keeping the temperature warm;
Regenerator water temperature detecting means for detecting a cooling water temperature of the regenerator,
When the regenerator water temperature detected by the regenerator water temperature detecting means is higher than the engine water temperature detected by the engine water temperature detecting means in a low load state of the engine, the cooling water of the regenerator is supplied to the engine. On the other hand, when the regenerator water temperature is lower than the engine water temperature even when the engine is in a low load state, control means for holding the cooling water of the regenerator without supplying it to the engine is provided. A cooling water temperature control device. The cooling water after cooling the engine is introduced into the regenerator when the regenerator water temperature is lower than the engine water temperature and the engine water temperature is equal to or higher than a predetermined temperature. Cooling water temperature control device.

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