JP2003184552A - Cooling water control system for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling water control system for internal combustion engine which simply and efficiently performs, without cost increase, the release of chilled water that has been stored in a heat accumulator in place of hot water to a cooling water circuit, while preventing the drop-off in engine performance and heater performance. <P>SOLUTION: At the time of cold starting of engine, when a change-over valve is changed over to heat accumulator side, cooling water at high temperature (hot water) thermally insulated and stored in the heat accumulator is released to the cooling water circuit and circulated, thereby engine warm-up is promoted, cooling water at low temperature (chilled water) is accumulated to replace hot water (S14). Subsequently, when the change-over valve is changed over to non-heat accumulation passage side, cooling water in the cooling water circuit gradually rises in temperature while circulating through the non-heat accumulation passage (S16), but when engine warm-up is complete, for example, it reaches the predetermined temperature or over (S18), the change-over valve will be changed over intermittently among a number of times to the heat accumulator side, and thus cooling water at low temperature accumulated in the heat accumulator is efficiently release more in predetermined quantity at a time to the cooling water circuit (S20 to S32). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling water control apparatus for an internal combustion engine, and more particularly to a cooling water circuit having a heat accumulator, the heat of the cooling water accumulated in the heat accumulator when the internal combustion engine is warmed up. The present invention relates to a technique for promoting warm-up by utilizing the engine at the cold start of the internal combustion engine.

[0002]

[Related Background Art] A heat storage device is installed in a cooling water circuit of an engine mounted on a vehicle to warm up the engine (internal combustion engine) for the purpose of promoting warm-up at cold start and ensuring heater performance. A high-temperature engine cooling water (warm water) is stored in the regenerator when the engine is in a warm state, and a cooling water control device that guides the high-temperature cooling water stored in the regenerator to the engine when the engine is cold started has been developed. Has been put to practical use.

In the cooling water control device having such a heat storage device, hot water is discharged from the heat storage device and at the same time, low temperature cooling water (cool water) from the engine is stored in the heat storage device. When the warm-up is completed, the cold water thus stored in place of the hot water is discharged from the heat accumulator to the cooling water circuit at once.

[0004]

By the way, when the cold water is discharged from the heat accumulator to the cooling water circuit at once at the time of completion of warming up of the engine, the once-heated engine is cooled rapidly and the engine performance is improved. Is temporarily lowered. In addition, a vehicle heater uses the heat of engine cooling water to heat the interior of the vehicle, but the heater temperature that has risen sufficiently after warm-up has been completed is temporarily reduced by the cold water discharged from the heat accumulator. There is also a problem in that the heater performance temporarily deteriorates, and the occupant of the vehicle feels uncomfortable.

For this reason, for example, there is an apparatus constructed so as to prevent the cooling water in the engine from being lowered by gradually discharging the cold water from the heat accumulator after the engine is warmed up. Is disclosed in.
However, in the device disclosed in the above publication, a water temperature sensor is separately provided in addition to the water temperature sensor provided at the cooling water outlet of the conventional engine, which leads to an increase in cost.
Further, in the device, when the heat is stored, the thermostat is opened and the high temperature cooling water from the engine is also circulated to the radiator to release the heat of the cooling water, which causes a problem that the heat storage of the heat storage device takes time. is there.

The present invention has been made to solve the above problems, and an object thereof is to discharge the cold water stored in the heat accumulator in place of the hot water to the cooling water circuit for the engine performance and the heater. An object of the present invention is to provide a cooling water control device for an internal combustion engine, which can be implemented efficiently while preventing deterioration in performance and without increasing cost.

[0007]

In order to achieve the above-mentioned object, the invention of claim 1 provides a cooling water control apparatus for an internal combustion engine, comprising a cooling water circuit for circulating cooling water of the internal combustion engine by a water pump. , Interposed in the cooling water circuit,
A heat accumulator that accumulates cooling water that has flowed out from the internal combustion engine and stores it warm, and a non-heat storage passage that circulates the cooling water that has flowed out of the internal combustion engine without passing through the heat accumulator, and is provided by bypassing the heat storage device, A switching valve for guiding cooling water flowing out of the internal combustion engine to the heat storage side and the non-heat storage passage side and a control means for controlling the switching valve are provided, and the control means controls the internal combustion engine to cool. In the state, the switching valve is temporarily switched to the heat storage side and then to the non-heat storage passage side to release the high temperature cooling water kept warm in the heat storage circuit to the cooling water circuit for circulation. When the low temperature cooling water is accumulated in the regenerator and the internal combustion engine is warmed up, the switching valve is intermittently switched to the regenerator side in a plurality of times to intermittently switch the low temperature of the low temperature accumulated in the regenerator. The specified amount of cooling water It is characterized in that to release circulated in 却水 circuit.

Therefore, when the engine (internal combustion engine) is started in the cold state, when the switching valve is switched to the heat storage side, the high temperature cooling water (warm water) kept warm in the heat storage is discharged to the cooling water circuit and circulated. When the engine warm-up is promoted, low-temperature cooling water (cold water) is accumulated in the heat storage device in turn, and when the switching valve is switched to the non-heat storage passage side, the cooling water in the cooling water circuit passes through the non-heat storage passage. The temperature gradually rises while circulating, but when the engine is warmed up and reaches, for example, a predetermined temperature or higher, the switching valve is intermittently switched to the heat accumulator side in multiple times. The accumulated low temperature cooling water is efficiently discharged into the cooling water circuit by a predetermined amount.

As a result, the engine performance is prevented from being deteriorated without being rapidly cooled, and when the cooling water circuit has the heater unit, the heater temperature is not drastically decreased and the heater performance is prevented from being deteriorated. To be done. Also,
In the invention of claim 2, when the internal combustion engine is warmed up, the control means discharges the low temperature cooling water accumulated in the heat accumulator to the cooling water circuit and lowers the cooling water by the low temperature cooling water. The heat quantity is obtained, and the switching valve is intermittently switched to the heat accumulator side in a plurality of times so that the heat quantity does not exceed an allowable decrease heat quantity.

Therefore, although the engine is cooled when the low-temperature cooling water is discharged to the cooling-water circuit, the switching valve is provided on the heat accumulator side a plurality of times so that the amount of heat reduced by the low-temperature cooling water does not exceed the allowable reduction heat amount. By intermittently switching to, the cold water accumulated in the heat accumulator is efficiently discharged,
Supercooling of the engine is reliably suppressed. As a result, deterioration of the engine performance is reliably prevented, and when the cooling water circuit has a heater unit, the deterioration of the heater performance is reliably prevented.

Further, according to the invention of claim 3, there is further provided cooling water temperature detecting means for detecting the temperature of the cooling water immediately after flowing out from the internal combustion engine, and the control means includes the cooling water temperature detecting means. Characterizing that the amount of heat stored in the regenerator is obtained based on the temperature of the cooling water when the internal combustion engine is in the cold state and when the warm-up is completed, and the amount of heat that is reduced by the low-temperature cooling water is obtained from the amount of the stored heat. There is.

Therefore, the amount of heat stored in the regenerator is obtained based on the temperature of the cooling water immediately after it has flowed out from the engine in the cold state and when the warm-up is completed. This amount of heat storage and the amount of heat reduced by the low-temperature cooling water Can be regarded as almost the same,
By determining the amount of heat stored in the regenerator, the amount of heat reduced by the low-temperature cooling water can be easily obtained with a simple and inexpensive structure.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. Referring to FIG. 1, there is shown a schematic configuration diagram of a cooling water control apparatus for an internal combustion engine mounted on a vehicle according to the present invention. Hereinafter, the configuration of the cooling water control apparatus will be described. Cylinder head 2 of engine (internal combustion engine) 1
The cylinder block 4 is provided with a water jacket through which engine cooling water (hereinafter, cooling water) flows,
As shown in the figure, the water outlet 6 and the water inlet 8 of the water jacket are connected by a cooling water passage 10.
That is, the engine 1 and the cooling water passage 10 constitute a cooling water circuit, and the cooling water circulates in the cooling water circuit.

The cooling water passage 10 mainly comprises a radiator passage 12, a heater passage 14 and a bypass passage 16. The configuration of the cooling water passage 10 will be described below.
The radiator passage 12 is provided so as to connect the water outlet 6 and the water inlet 8 of the water jacket, and the radiator passage 12 is provided with a radiator 11 for heat exchange. Also, the water inlet 8 of the radiator passage 12
A water pump 13 is interposed in the vicinity, and when the water pump 13 operates, the cooling water is pumped and circulates in the cooling water circuit.

The heater passage 14 is provided so as to bypass the radiator passage 12, and a heater unit 15 for heating the interior of the vehicle is provided in the heater passage 14. A heat accumulator 20 is further provided in the heater passage 14 via a control valve 22. The heat accumulator 20 accumulates and temporarily stores cooling water that has been heated during warm-up of the engine 1, that is, warm water, and the stored warm water can be used for the purpose of promoting warm-up when the engine 1 is cold started. It is a heat storage type water storage container configured.

The control valve 22 circulates the cooling water flowing through the heater passage 14 to the regenerator 20, or shuts off the communication between the heater passage 14 and the regenerator 20 so as not to circulate to the regenerator 20. And the control valve controller 4
It is electrically connected to 0. That is, the control valve 22 is configured to cause the cooling water to flow to the heat storage device 20 at the valve position P1 and to shut off the communication between the heater passage 14 and the heat storage device 20 at the valve position P2 in response to a command from the control valve controller 40. Has been done.

The bypass passage 16 is provided so as to branch from the control valve 22 and bypass the heater passage 14.
As a result, the control valve 22 is configured so that it can be combined with the valve positions P1 and P2 to switch between communication and cutoff of the cooling water to the bypass passage 16. That is, the cooling water circuit, based on the command from the control valve controller 40,
When the control valve 22 is switched to the valve position P1, the cooling water is circulated to the regenerator 20 and accumulated in the regenerator 20, and the cooling water in the regenerator 20 flows out to the heater passage 14 or the bypass passage 16, and When the control valve 22 is switched to the valve position P2, the cooling water bypasses the heat accumulator 20 and flows through the heater passage 14 or the bypass passage 16 and the cooling water accumulated in the heat accumulator 20 is blocked and stored in the heat accumulator 20. It is configured to be stored (non-heat storage passage).

A thermostat (T / S) 24 is provided at the confluence of the radiator passage 12 and the heater passage 14. The thermostat (T / S) 24 is provided in the heater passage 1
It is an on-off valve that opens when the temperature of the cooling water flowing through 4 rises to a predetermined temperature and allows the cooling water to flow through the radiator passage 12. As the thermostat (T / S) 24,
A common wax type thermostat is used.

Further, as shown in the figure, in the vicinity of the water outlet 6 of the radiator passage 12, a water temperature sensor (cooling water temperature detecting means) for detecting the temperature of the cooling water immediately after it comes out of the engine 1.
30 are provided. The water temperature sensor 30 is electrically connected to the control valve controller 40. The control valve controller 40 is further electrically connected to an outside air temperature sensor 34 that detects the temperature of outside air and a heater SW (switch) 36 that supplies an operation command to the heater unit 15.

The control valve controller 40 is also connected to an electronic control unit (ECU) 50. E
The CU 50 is a main control unit that performs overall control of the engine 1 and the like. The input side of the ECU 50 is connected with an ignition SW (switch) 52 for starting the engine 1, various switches and various sensors, and an output side. Various devices are electrically connected to the.

The operation of the cooling water control device according to the present invention thus constructed will be described below. Referring to FIG. 2, a control routine of the cooling water control at the time of cold start of the cooling water control device according to the present invention is shown in a flow chart (control means), and referring to FIG. 3, the control routine is executed. The change in the control valve position and the change in the temperature of the cooling water in the case of the above are shown in a time chart, which will be described below with reference to FIG. In FIG. 3, the solid line indicates the cooling water temperature T, that is, the water temperature sensor 30.
Shows the temperature of the cooling water near the water outlet 6 based on the information from
The broken line indicates the temperature of the warm air blown out from the heater unit 15, and the alternate long and short dash line indicates the temperature of the cooling water in the heat storage unit 20.

First, in step S10, the water temperature sensor 3
Based on the information from 0, the starting water temperature T0, that is, the temperature of the low-temperature cooling water (cold water) in the engine 1 before the cold start is detected. In step S12, the ignition SW5
2 is operated to determine whether the engine 1 has been started. If the determination result is false (No), the detection of the starting water temperature T0 is continued, and if the determination result is true (Yes), the process proceeds to step S14.

In step S14, the cooling water control device is set to the hot water discharge mode. That is, the cooling water accumulated when the engine 1 is warmed up is stored in the heat storage unit 20 as hot water, and in step S14, the control valve 22 is switched to the valve position P1 to change the hot water stored in the heat storage unit 20. Engine 1
Release towards. As a result, the engine 1 in the cold state
Warming up is promoted. On the other hand, at this time, instead of the discharged warm water, the cold water in the engine 1 flows into and accumulates in the heat storage device 20.

Immediately after the cold start, the thermostat 24 is closed and the cooling water is supplied to the heater SW3.
When 6 is turned on or when the heater unit 15 is operating according to the information from the outside air temperature sensor 34, it flows through the heater passage 14, and when the heater SW 36 is turned off, the control valve 22 is switched. And flow through the bypass passage 16. That is, at this time point, the cooling water does not flow through the radiator passage 12 and is not cooled by the radiator 11.

The temperature of the thermostat 24 is set so as not to open until the engine 1 sufficiently exceeds the warmed-up state, and therefore, the thermostat 24 does not open while the cooling water control is being performed. . In step S16, the cooling water control device is set to the cold water holding mode. That is, the control valve 22
Is switched to the valve position P2, and cold water is stored and held in the heat accumulator 20.

When the control valve 22 is switched to the valve position P2 in this way, as shown in FIG. 3, the temperature inside the regenerator 20 (dashed line) decreases, and the cooling water temperature T (solid line) also changes.
After passing through the engine 1, the hot water from is temporarily decreased, but thereafter, the cooling water temperature T (solid line) is gradually increased by the combustion heat of the engine 1. And
In step S18, the cooling water temperature T exceeds the first predetermined temperature T1 corresponding to the warm-up completion state of the engine 1 (T> T
1) Determine whether or not. If the determination result is false (No) and the cooling water temperature T has not yet reached the predetermined temperature T1,
In step S16, the cold water holding mode is maintained, and the rise of the cooling water temperature is waited for. On the other hand, when the determination result of step S18 is true (Yes) and it is determined that the cooling water temperature T exceeds the predetermined temperature T1, the process proceeds to step S20.

In step S20, in response to the fact that the temperature T of the cooling water exceeds the predetermined temperature T1, the discharge of the cold water stored in the heat accumulator 20 is started. That is, the control valve 22 is switched to the valve position P1 again, and the discharge of the cold water stored in the heat storage device 20 is started. In other words, the storage of the cooling water whose temperature has risen due to warming up in the heat storage device 20, that is, the heat storage in the heat storage device 20 is started.

In step S22, the heat storage amount qc per unit time in the heat storage unit 20 is calculated from the following equation (1) based on the temperature difference (T1-T0). qc = dn · c · kn · (T1−T0) (1) where c is the specific heat of the cooling water, dn is the flow rate of the cooling water, and is proportional to the engine speed Ne, the following equation (2) It is calculated from

Dn = aNe (2) where a is a constant of proportionality. Further, kn is a reduction coefficient for (T1−T0) described later (0 <kn ≦
1), the initial value is 1. The engine 1 is actually
It is conceivable that the amount of heat generated by the heater unit, the amount of heat radiated from the heater unit 15, or the amount of heat radiated to the atmosphere may be transferred, but these can be ignored if the discharge time of cold water is short.
For simplification of calculation, it is not considered in the above formula (1).

Then, in step S24, the heat storage amount qc is integrated to obtain the heat storage amount Q (Q = Q
+ Qc) and the cooling water flow rate dn are integrated to obtain the cold water discharge amount D (D = D + dn). In step S26, the stored heat quantity Q exceeds the predetermined allowable heat quantity decrease Q1 (Q> Q
1) Determine whether or not. Here, the permissible decrease heat quantity Q1 is a value calculated from the following equation (3) based on the permissible water temperature decrease quantity dT preset for the cooling water and the heat capacity C of the effective circulating water quantity of the cooling water, and It shows the range of decrease in the allowable heat quantity.

Q1 = C · dT (3) That is, in step S26, the engine 1 is cooled by removing heat from the cooling water due to the release of the cooling water from the heat storage device 20, but the cooling water in the heat storage device 20 is cooled. Since the amount of water supplied and discharged can be considered to be the same, the amount of heat depleted from the cooling water and reduced is obtained from the amount of heat Q stored in the heat storage device 20, and whether or not this reduced amount of heat does not supercool the engine 1 is determined. To determine.

The determination result of step S26 is false (No).
When it is determined that the heat quantity Q has not exceeded the allowable decrease heat quantity Q1, the process returns to step S20 to continue the discharge of cold water from the heat storage device 20, and the determination result is true (Yes),
If it is determined that the heat quantity Q has exceeded the permissible reduced heat quantity Q1, the process proceeds to step S28. That is, the step S2
According to the determination of 6, the amount of cold water discharged once for discharging cold water from the heat storage device 20 is defined.

In step S28, the cold water discharge amount D exceeds a predetermined value D1 corresponding to the volume V of the heat storage device 20 (D
> D1) is determined. That is, the amount of cold water stored in the heat accumulator 20 should be basically equal to the volume V of the heat accumulator 20, and here, all the cold water in the heat accumulator 20 is discharged to be completely warm water. It is determined whether or not they have been replaced.

The predetermined value D1 is the coefficient K to the volume V here.
It is a value (D1 = K · V) multiplied by (K> 1). With this configuration, the warm water flowing into the heat storage unit 20 is stored in the heat storage unit 20.
As a result of mixing with cold water in the interior, even if cold water remains in the heat storage device 20 at the time when the cold water discharge amount D reaches the volume V of the heat storage device 20, the cold water discharge amount D does not change the volume V of the heat storage device 20. The discharge of cold water will be continued until it is sufficiently exceeded, and the heat accumulator 20 will be well filled with hot water.

The determination result of step S28 is false (No).
If it is determined that the cold water discharge amount D has not yet exceeded the predetermined value D1, the process proceeds to step S30. Step S
At 30, the cooling water control device is again set to the cold water holding mode. That is, the control valve 22 is switched to the valve position P2, and cold water is again stored and held in the heat storage device 20. As a result, as shown in FIG. 3, the temperature in the regenerator 20 (dashed line) is maintained higher than the previous time, and the cooling water temperature T (solid line) gradually rises again due to the combustion heat of the engine 1.

Then, in step S32, it is determined whether or not the cooling water temperature T exceeds the second predetermined temperature T2 corresponding to the completely warmed-up state of the engine 1 (however, T2 ≧ T1). The determination result is false (No) and the cooling water temperature T is still the predetermined temperature T.
If it has not reached 2, the cold water holding mode is maintained in step S30 and the temperature of the cooling water is waited for. On the other hand, when the determination result of step S32 is true (Yes) and it is determined that the cooling water temperature T exceeds the predetermined temperature T2, the process returns to step S20, and thereafter, the determination result of step S28 is true (Yes). Until, that is, until the chilled water discharge amount D exceeds the predetermined value D1, chilled water discharge and holding are repeated.

In this case, the reduction coefficient kn in the above equation (1) is reduced at a constant rate each time the cold water is repeatedly discharged and held. That is, when the cold water is discharged once, the hot water flows into the heat storage device 20 by the amount of the released cold water, and the temperature of the cooling water in the heat storage device 20 is the initial starting water temperature T.
It is higher than 0, and the actual temperature difference is (T1-T0)
Therefore, the reduction coefficient kn is reduced at a constant rate every time the cold water is released and held, and the temperature difference (T1−T0) is corrected.

As a result, the amount of hot water stored in the regenerator 20 once can be increased, and heat can be efficiently stored in the regenerator 20. The determination result of step S28 is true (Yes
In s), the cold water discharge amount D exceeds the predetermined value D1,
When it is determined that all the cold water in the inside has been discharged, the process proceeds to step S34, and the cooling water control device is set to the constant heat storage mode. That is, the control valve 22 is switched to the valve position P1 so that the cooling water always flows in the heat accumulator 20. As a result, hot water having a high temperature is always stored and stored in the heat storage device 20, and the hot water in the heat storage device 20 is effectively used at the next cold start.

At this time, as described above, the predetermined value D1 is the value obtained by multiplying the volume V by the coefficient K (D1 = KV), and when the determination result of step S28 is true (Yes), the heat storage unit 20 is stored. Therefore, the hot water at the substantially second predetermined temperature T2 is sufficiently filled, so that the cooling water temperature T will not be further reduced when the cooling water control device is constantly switched to the heat storage mode.

As described above, in the cooling water control device of the present invention, the amount of heat reduced by the discharge of the cold water falls within the preset allowable reduction heat amount Q1 without discharging the cold water in the heat storage device 20 at once. , The cold water is efficiently discharged repeatedly in several times. Therefore,
According to the cooling water control device of the present invention, when the cold water is discharged from the heat storage device 20, it is possible to prevent a sharp decrease in the cooling water temperature so as not to deteriorate the engine performance, and to prevent the heater temperature from decreasing. The heater performance can be prevented from deteriorating. Further, since the cooling water control can be performed only by the water temperature sensor 30, it is possible to easily store heat in the heat storage device 20 with a simple and inexpensive configuration while preventing deterioration of engine performance and heater performance.

Although the description is finished above, the embodiment of the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the amount of cold water discharged at one time is calculated based on the temperature difference (T1−T0) of the cooling water and the engine rotation speed Ne as in equations (1) and (2). The correction may be made according to the information from the outside air temperature sensor 34 or the operating condition of the heater unit 15.

[0042]

As described above in detail, according to the cooling water control apparatus for an internal combustion engine of claim 1 of the present invention, when the engine (internal combustion engine) is cold-started, the high temperature stored in the heat accumulator is maintained. Cooling water (warm water) is discharged to the cooling water circuit and circulated, and low temperature cooling water (cold water) from the engine is stored in the heat accumulator instead of the hot water to promote warming up of the engine and the engine is warmed up. When doing so, the cold water accumulated in the heat accumulator is divided into a plurality of predetermined amounts and discharged into the cooling water circuit, so that the cold water accumulated in the heat accumulator can be efficiently circulated in the cooling water circuit. The engine performance can be prevented from being deteriorated by not rapidly cooling the engine, and the heater performance can be prevented from being deteriorated by not decreasing the heater temperature when the cooling water circuit has a heater unit.

Further, according to the cooling water control apparatus for an internal combustion engine of claim 2, the switching valve is intermittently switched to the heat accumulator side in plural times so that the amount of heat reduced by the cold water does not exceed the allowable amount of reduction heat. Since the cold water accumulated in the heat accumulator is efficiently discharged, it is possible to reliably prevent the engine from overcooling and prevent the engine performance from deteriorating, and when the cooling water circuit has a heater unit. It is possible to reliably prevent the deterioration of the heater performance.

Further, according to the cooling water control apparatus for an internal combustion engine of claim 3, the amount of heat stored in the heat accumulator is obtained based on the temperature of the cooling water immediately after flowing out from the engine in the cold state and when the warm-up is completed. Since the amount of heat reduced by cold water is obtained from this amount of stored heat, the amount of heat reduced by cold water can be easily obtained with a simple and inexpensive configuration.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a cooling water control device for an internal combustion engine according to the present invention, which is mounted on a vehicle.

FIG. 2 is a flowchart showing a control routine of cooling water control at the time of cold start of the cooling water control device according to the present invention.

FIG. 3 is a time chart showing changes in control valve position and changes in cooling water temperature when the control routine of FIG. 2 is executed.

[Explanation of symbols]

1 engine 10 Cooling water passage 12 radiator passage 13 Water pump 14 Heater passage 15 heater unit 20 heat accumulator 22 Control valve 30 Water temperature sensor 40 Control valve controller 50 Electronic Control Unit (ECU) 52 Ignition SW

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Souki Mizukami             Mitsubishi Motors, 5-3-8 Shiba, Minato-ku, Tokyo             Industry Co., Ltd. (72) Inventor Kiyoshi Hatano             Mitsubishi Motors, 5-3-8 Shiba, Minato-ku, Tokyo             Industry Co., Ltd.

Claims (3)

[Claims] 1. A cooling water control device for an internal combustion engine, comprising: a cooling water circuit for circulating cooling water for an internal combustion engine by a water pump; and storing cooling water which is interposed in the cooling water circuit and flows out from the internal combustion engine. And a heat storage device for keeping warm storage, a non-heat storage passage that is provided to bypass the heat storage device and circulates cooling water flowing out of the internal combustion engine without passing through the heat storage device, and cooling water flowing out of the internal combustion engine. A switching valve that switches between the heat storage device side and the non-heat storage passage side to guide the switching valve, and a control unit that controls the switching valve, the control unit temporarily turning on the switching valve when the internal combustion engine is in a cold state. After switching to the heat storage side, switching to the non-heat storage path side, the high temperature cooling water kept warm in the heat storage device is discharged to the cooling water circuit for circulation and at the same time the low temperature cooling water is stored in the heat storage device. Let, before When the internal combustion engine is completely warmed up, the switching valve is intermittently switched to the heat storage side by dividing it into a plurality of times to discharge the low temperature cooling water accumulated in the heat storage unit to the cooling water circuit in predetermined amounts. A cooling water control device for an internal combustion engine, which is circulated. 2. The control means discharges the low temperature cooling water accumulated in the heat accumulator to the cooling water circuit when the internal combustion engine is warmed up, and reduces the amount of heat reduced by the low temperature cooling water. 2. The cooling water control apparatus for an internal combustion engine according to claim 1, wherein the switching valve is intermittently switched to the heat accumulator side by dividing the switching valve into a plurality of times so that the heat amount does not exceed an allowable decrease heat amount. 3. A cooling water temperature detecting means for detecting the temperature of the cooling water immediately after flowing out from the internal combustion engine, wherein the control means is provided for the internal combustion engine detected by the cooling water temperature detecting means. The amount of heat stored in the heat accumulator is obtained based on the temperature of the cooling water in the cold state and at the time of completion of warm-up, and the amount of heat reduced by the low-temperature cooling water is obtained from the amount of the stored heat. Cooling water control device for internal combustion engine.