WO2013108551A1

WO2013108551A1 - Water-cooling apparatus for engine

Info

Publication number: WO2013108551A1
Application number: PCT/JP2012/083441
Authority: WO
Inventors: 岩崎　充
Original assignee: カルソニックカンセイ株式会社
Priority date: 2012-01-17
Filing date: 2012-12-25
Publication date: 2013-07-25
Also published as: JP6023430B2; JP2013147942A; US20150053777A1

Abstract

A water-cooling apparatus for an engine, that cools an internal combustion engine using cooling water, and comprises: a radiator that cools the cooling water; a first flow path that causes the cooling water to flow into the engine; a second flow path that branches from the first flow path, and causes the cooling water to flow into the radiator; a third flow path that causes the cooling water from the radiator to flow into the first flow path, further downstream from the branching point of the second flow path from the first flow path; an adjustment valve arranged upon the first flow path and which controls the flow volume of the cooling water that flows through the radiator; and a pump arranged upon the first flow path, that circulates the cooling water through the engine and/or the radiator. The adjustment value is configured such that, when the adjustment valve is open, the cooling water from the radiator is caused to flow into the first flow path. This water-cooling apparatus is capable of performing suitable cooling by having a simple circulation flow path for cooling water, and adjusting the flow volume of the cooling water that flows through the circulation flow path.

Description

Engine water cooling device

The present invention relates to an engine water cooling device [a [water-cooling apparatus for engine], and more particularly to an engine water cooling device that controls cooling water by a pump and a regulating valve.

An engine water cooling system that drives an engine-driven pump (engine-driven pump) according to the rotational speed (revolving speed) of an internal combustion engine (hereinafter simply referred to as the engine) to circulate cooling water to the cylinder head and cylinder block is well known. It has been.

In such a water cooling device, since the flow rate of the cooling water [flow volume] is proportional to the engine speed, the cooling water flow rate may become excessive under cold conditions where the rotation speed is high or during high speed driving. For this reason, warm-up may be delayed due to excessive heat dissipation of the cooling water, resulting in a large power loss. Further, since the flow rate of the cooling water is proportional to the engine speed, knocking due to a cooling delay may occur when the engine load suddenly increases due to sudden acceleration or the like.

In order to cool the engine according to the engine load, a water cooling device is also proposed in which a bypass flow path that bypasses the radiator and a dedicated pump for cooling the combustion cylinder are provided (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-161606

However, such a water cooling device increases the number of parts and complicates the flow path of the cooling water. Accordingly, an object of the present invention is to provide an engine water cooling device having a simple cooling water circulation channel and capable of performing suitable cooling by adjusting the flow rate of the cooling water flowing through the circulation channel. is there.

A feature of the present invention is an engine water cooling device that cools an internal combustion engine with cooling water, the radiator cooling the cooling water by heat exchange between the cooling water and air, and the cooling water flowing into the engine A first flow path, a second flow path branched from the first flow path and allowing the cooling water to flow into the radiator, and the cooling water from the radiator is passed through the first flow of the second flow path. A third flow path that flows into the first flow path downstream from a branch point from the path; an adjustment valve that is disposed on the first flow path and that controls the flow rate of the cooling water that flows through the radiator; And a pump that circulates the cooling water to the engine and / or the radiator, and the adjustment valve causes the cooling water from the radiator to flow into the first flow path when opened. It is configured to provide an engine water cooler.

It is a schematic block diagram of the engine water cooling apparatus which concerns on 1st Embodiment. It is a schematic side view which shows arrangement | positioning of the said engine. (A) is a graph which shows the relationship between the cooling water temperature at the time of high load of the said engine, and combustion efficiency, (b) is a graph which shows the relationship between the cooling water temperature at the time of low load, and combustion efficiency. It is a flowchart which shows the warming-up control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the said warm-up control. (A) is a schematic perspective view which shows the natural convection of the cooling water in the said water cooling engine, (b) is a schematic side view. It is a flowchart which shows the normal control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the said normal control (low load state). It is the schematic (2) which shows the flow of the cooling water in the said normal control (high load state). It is a schematic block diagram of the engine water cooling apparatus which concerns on the modification of 1st Embodiment. It is the schematic which shows the flow of the cooling water in the warming-up control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the normal control (low load state) of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the normal control (high load state) of the said water cooling apparatus. It is a schematic block diagram of the engine water cooling apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the warming-up control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the said warm-up control. It is a flowchart which shows the normal control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the said normal control (low load state). It is a schematic block diagram of the engine water cooling apparatus which concerns on the modification of 2nd Embodiment. It is the schematic which shows the flow of the cooling water in the warming-up control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the normal control (low load state) of the said water cooling apparatus. It is a schematic block diagram of the engine water cooling apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the warming-up control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the said warm-up control. It is a flowchart which shows the normal control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the said normal control (low load state). It is a schematic block diagram of the engine water cooling apparatus which concerns on the modification of 3rd Embodiment. It is the schematic which shows the flow of the cooling water in the warming-up control of the said water cooling apparatus. It is the schematic which shows the flow of the cooling water in the normal control (low load state) of the said water cooling apparatus.

Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same or equivalent components are denoted by the same reference numerals. Note that the drawings are schematically shown, and the dimensions and ratios of each part in the figure do not accurately show the actual dimensions, and the actual dimensions and ratios of each part are determined in consideration of the following explanation. It should be. Also, the dimensions, ratios, and the like of each part may be shown differently between the drawings.

(First embodiment)
As shown in FIG. 1, the engine water cooling device 1 a according to the first embodiment is configured to convert a water-cooled internal combustion engine (hereinafter simply referred to as an engine) 2 into cooling water (cooling liquid [ cool]). The water cooling device 1 a includes a radiator 3, a first flow path 31, a second flow path 30, a third flow path 32, a regulating valve 11, and a pump 10. Yes. In the radiator 3, heat exchange is performed between the cooling water of the engine 2 and the air, and the cooling water is cooled. The first flow path 31 is located on the upstream side of the engine 2 on the cooling water circulation path, and allows the cooling water to flow into the engine 2. The second flow path 30 is located on the upstream side of the radiator 3 on the circulation path, and allows cooling water to flow into the radiator 3. The third flow path 32 is located on the downstream side of the radiator 3 on the circulation path, and allows cooling water to flow into the first flow path 31 from the radiator 3.

The adjusting valve 11 is disposed on the first flow path 31 and adjusts the flow rate of the cooling water flowing through the engine 2 and / or the radiator 3. The pump 10 is also disposed on the first flow path 31 (on the downstream side of the adjustment valve 11), and circulates the cooling water along the circulation path. The upstream end of the second flow path 30 is connected to the first flow path 31 (regulation valve 11), and the downstream end is connected to the radiator 3. The upstream end of the third flow path 32 is connected to the radiator 3, and the downstream end is connected to the first flow path 31. When the adjustment valve 11 is opened, the cooling water flows into the first flow path 31 through the second flow path 30, the radiator 3 and the third flow path 32.

As shown in FIG. 2, the engine 2 is disposed so as to be inclined so that the exhaust side faces downward. Since the exhaust side of the engine 2 is on the bottom, when the pump 10 is stopped, as a result of the rise of the exhaust side cooling water temperature, the cooling water flows to the intake side (upward) by natural convection. Therefore, even if the pump 10 is stopped, the cooling water temperature around the cylinder head of the engine 2 can be made uniform by natural convection, and the cooling water can be circulated through the radiator 3. The inclination α (°) of the engine 2 is preferably about 20 ° in consideration of natural convection of the cooling water. If the inclination of the combustion cylinder central axis of the engine 2 with respect to the horizontal is β (°), α = 90 ° −β.

The engine 2 is cooled by the cooling water from the first flow path 31, and the cooling water flows out to the fourth flow path 20. A temperature sensor (not shown) is disposed in the fourth flow path 20. The temperature sensor detects the coolant temperature flowing out of the engine 2 (that is, in the engine 2). The detection data of the temperature sensor is output to a controller (not shown).

The combustion efficiency depending on the cooling water temperature of the engine 2 will be described with reference to the graphs of FIGS. 3 (a) and 3 (b). When the load of the engine 2 (here, the indicated mean effective pressure [Indicated Mean Effective Pressure]: indicating the load by IMEP) is low (low load: 300 kPa), as shown in FIG. The fuel efficiency (here, the combustion efficiency is indicated by the indicated thermal efficiency) is higher at a high temperature of 100 ° C. (second temperature). On the other hand, when the load is high (high load: 900 kPa), as shown in FIG. 3B, the fuel efficiency is better at the cooling water temperature of 80 ° C. (first temperature).

The radiator 3 is a device that dissipates the heat of the engine 2 through cooling water, and has a structure in which many tubes having fins made of aluminum alloy or the like are arranged. The inflow side of the radiator 3 is connected to the downstream end of the second flow path 30, and the outflow side is connected to the upstream end of the third flow path 32.

The heater core 4 is disposed on the downstream side of the fourth flow path 20 on the cooling water circulation path, and the outflow side is connected to the pump 10 by the fifth flow path 22. An electromagnetic valve 25 that adjusts the flow rate of the cooling water is disposed on the fourth flow path 20 on the upstream side of the heater core 4. The flow rate of the cooling water flowing through the heater core 4 is adjusted by adjusting the valve opening degree of the electromagnetic valve 25, and the heat radiation amount in the heater core 4 is adjusted. As a result, the cooling water temperature is also adjusted. The heater core 4 heats the air by heat exchange between the cooling water heated by the engine 2 and the air. The heated air is used for air conditioning and the like.

Furthermore, a sixth flow path 24 that bypasses the heater core 4 is also provided. The upstream end of the sixth flow path 24 is connected to the fourth flow path 20 on the upstream side of the electromagnetic valve 25, and the downstream end is connected to the fifth flow path 22. When the electromagnetic valve 25 is closed, the cooling water bypasses the heater core 4 and flows through the sixth flow path 24.

The pump 10 of the present embodiment is an electric pump P ₁ that can be operated independently of the operation of the engine 2. The pump 10 (electric pump P ₁ ) controls the flow rate of the cooling water based on a signal from a controller (not shown).

The adjustment valve 11 is disposed on the downstream side of the pump 10 on the first flow path 31. A second flow path 30 is branched from the adjustment valve 11. The adjustment valve 11 is a three-way valve that allows cooling water from the pump 10 to flow to the engine 2 and / or the second flow path 30. The adjustment valve 11 is an electronically controlled thermostat, and controls the flow rate of the cooling water flowing to the engine 2 and / or the radiator 3 with respect to the cooling water from the pump 10 based on a signal from a controller (not shown). The adjustment valve 11 of the present embodiment controls the flow rate of the cooling water that flows to the radiator 3 upstream of the radiator 3.

Hereinafter, warm-up control of the engine 2 by the water cooling device 1a will be described with reference to the flowchart shown in FIG.

First, it is determined whether or not the cooling water temperature detected by the temperature sensor is equal to or lower than a first temperature (80 ° C.) as an index for completion of warm-up (step S10). When the cooling water temperature is higher than the first temperature (80 ° C.) (NO in step S10), the control shifts to normal control after warm-up (step S30), and the warm-up control ends. The normal control will be described in detail later. On the other hand, when the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), it is determined whether or not the air conditioning heater switch is on (step S11).

If the heater switch is not on (NO in step S11), the controller sends control signals to the pump 10, the adjustment valve 11 and the electromagnetic valve 25 so that the cooling water temperature becomes higher than the first temperature (80 ° C.) earlier. Send. Here, since the heater switch is off, there is no need to flow cooling water through the heater core 4. Therefore, the solenoid valve 25 on the upstream side of the heater core 4 is closed based on the control signal from the controller (step S12). Further, as shown in FIG. 5, the second flow path 30 is also closed by the adjustment valve 11 (step S <b> 14 described later), and the cooling water is not allowed to flow to the radiator 3. As a result, heat is not dissipated in the radiator 3 and the heater core 4, and the cooling water is made higher than the first temperature (80 ° C.) earlier.

Subsequent to step S12, the pump 10 (electric pump P ₁ ) is stopped based on a control signal from the controller, and stops the supply of cooling water to the engine 2 (step S13). Since the engine 2 is inclined as shown in FIGS. 6A and 6B, the cooling water flows by natural convection even when the pump 10 is stopped. Therefore, even if the cooling water is not forced to circulate by the pump 10, the cooling water circulates in the water cooling device 1a by natural convection. However, as a result, the coolant temperature in the engine 2 is quickly increased to a temperature with good thermal efficiency by absorbing the heat of the engine 2.

Subsequent to step S13, the adjustment valve 11 closes the second flow path 30 (at its upstream end) based on a control signal from the controller (step S14). Since the second flow path 30 is closed, heat is not radiated by the radiator 3, and a decrease in the coolant temperature during the warm-up control can be prevented. After step S14, the process flow returns to step S10. When the cooling water temperature becomes higher than the first temperature (80 ° C.) (NO in step S10), the process proceeds to normal control (step S30).

On the other hand, when the heater switch is on in step S11 (YES in step S11), the solenoid valve 25 on the upstream side of the heater core 4 is controlled so that the cooling water flows through the heater core 4 for heating. Specifically, the electromagnetic valve 25 is set to a valve opening degree at which the cooling water flows through the heater core 4 at 10 L / min based on a control signal from the controller (step S20).

Subsequent to step S20, the discharge amount of the pump 10 is also controlled based on the control signal from the controller so that the cooling water flow rate to the heater core 4 is 10 L / min (step S21). Here, natural convection also occurs due to the inclination of the engine 2 shown in FIGS. 6A and 6B, so that the driving energy of the pump 10 can be reduced. That is, the cooling water amount of 10 L / min to the heater core 4 is realized by the valve opening degree of the electromagnetic valve 25 and the discharge amount of the pump 10.

Following step S21, the adjustment valve 11 closes the second flow path 30 based on the control signal from the controller (step S22). Since the second flow path 30 is closed, heat is not radiated by the radiator 3, and a decrease in the coolant temperature during the warm-up control can be prevented. Although heat is dissipated in the heater core 4 for heating, heat is not dissipated in the radiator 3, and the cooling water becomes higher than the first temperature (80 ° C.) earlier. After step S22, the process flow returns to step S10. When the cooling water temperature becomes higher than the first temperature (80 ° C.) (NO in step S10), the process proceeds to normal control (step S30).

Next, normal control (after warming up) of the engine 2 by the water cooling device 1a will be described with reference to the flowchart shown in FIG.

First, it is determined whether or not the engine 2 is idling (step S110). If the engine is not idling (NO in step S110), it is determined whether or not the change in the throttle opening is small in order to determine the operating state of the engine 2 (step S111). The throttle opening is a valve opening of a throttle valve that is disposed on the intake passage of the engine 2 and adjusts the intake air amount (in an engine having an intake air amount control mechanism of a type in which no throttle valve is provided). (The change in throttle opening means the change in intake air amount control parameter). The case where the change in throttle opening is small is a steady state such as traveling at a constant speed and the case where the engine 2 is operated at a low load. On the other hand, the case where the throttle opening change is large is a transient state such as acceleration or climbing, and is a case where the engine 2 is operated at a high load.

When the throttle opening change is small (smaller than the predetermined opening change), that is, when the engine 2 is in a low load state (YES in step S111), the cooling water temperature becomes the second temperature (100 ° C.). The controller transmits control signals to the pump 10, the regulating valve 11, and the electromagnetic valve 25. As shown in FIG. 3A, when the engine 2 is in a low load state, the fuel efficiency is better when the cooling water temperature is the second temperature (100 ° C.) higher than the first temperature (80 ° C.). The cooling water temperature is set to the second temperature (100 ° C.).

Specifically, since the warm-up has been completed, the electromagnetic valve 25 is opened based on the control signal from the controller in order to circulate the cooling water through the heater core 4 (step S112). Thereby, the air conditioner can use the heat of the heater core 4 at any time. If idling is being performed in step S110 (YES in step S110), the control flow proceeds to step S112 without performing the determination in step S111 because the throttle load is not changed.

Subsequent to step S112, based on the control signal from the controller, the pump 10 (electric pump P ₁ ) circulates the cooling water, but the flow rate is controlled to be small (step S113). By reducing the flow rate, heat dissipation in the heater core 4 and the radiator 3 is suppressed, and the cooling water temperature rises to the second temperature (100 ° C.) (the flow of cooling water to the radiator 3 is the next step S114) explain).

Subsequent to step S113, the valve opening of the adjustment valve 11 is adjusted based on a control signal from the controller, and the flow rate of the cooling water flowing through the radiator 3 is adjusted at the upstream end of the second flow path 30 (step S114). . In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are relatively reduced (FIG. 8). reference). The adjustment valve 11 also flows the cooling water from the pump 10 to the engine 2.

On the other hand, when the throttle opening change is large (larger than the predetermined opening change) in step S111, that is, when the engine 2 is in a high load state (NO in step S111), the cooling water temperature is the first temperature (80 ° C.). The controller transmits control signals to the pump 10, the regulating valve 11 and the electromagnetic valve 25. As shown in FIG. 3B, when the engine 2 is in a high load state, the fuel efficiency is better when the cooling water temperature is the first temperature (80 ° C.) lower than the second temperature (100 ° C.). The cooling water temperature is set to the first temperature (80 ° C.).

Specifically, since the warm-up has been completed, the electromagnetic valve 25 is opened based on the control signal from the controller in order to circulate the cooling water through the heater core 4 as in step S112 described above (step S112). S120). Subsequent to step 120, based on the control signal from the controller, the pump 10 (electric pump P ₁ ) circulates the cooling water, but the flow rate is controlled to a high level (step S121). Increasing the flow rate promotes heat dissipation in the radiator 3, and the cooling water temperature is kept at the first temperature (80 ° C.) by suppressing the rise (the next step for the cooling water flow to the radiator 3 This will be described in S122).

Subsequent to step S121, the valve opening of the adjusting valve 11 is adjusted based on a control signal from the controller, the flow path to the first flow path 31 connected to the engine 2 is closed, and the second flow path 30 The valve opening degree of the upstream end is fully opened (step S122), and the cooling water is allowed to flow only in the second flow path 30, the radiator 3, and the third flow path 32 (see FIG. 9). In order to promote heat dissipation in the radiator 3 and set the cooling water temperature to the first temperature (80 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are increased. The cooling water flows to the engine 2 after flowing through the second flow path 30, the radiator 3, and the third flow path 32. As a result, heat dissipation in the radiator 3 is promoted, and the cooling water temperature is lowered to the first temperature (80 ° C.).

According to the water cooling device 1a of the present embodiment, since the third flow path 32 for flowing the cooling water flowing out from the radiator 3 to the engine 2 is provided, the cooling water flow path is not increased without increasing the number of parts. The cooling water temperature control and flow rate adjustment can be easily performed without complicating the flow rate.

Furthermore, the third flow path 32 at the time of low load (see FIG. 8) is filled with cooling water of about 60 ° C. cooled by the radiator 3. Here, when the cooling water is pushed into the radiator 3 through the second flow path 30 by the adjustment valve 11, the water in the third flow path 32 is cooled by the cooling in the first flow path 31 because water is an incompressible fluid. After joining with water, it flows into the engine 2. Therefore, when the flow rate to the second flow path 30 is increased by the adjustment valve 11 when shifting from a low load state to a high load such as sudden acceleration (FIG. 8 → FIG. 9), the temperature in the third flow path 32 is 60 ° C. A certain amount of cooling water flows into the engine 2 after joining with the cooling water in the first flow path 31. As a result, the cooling water temperature can be instantaneously changed from the second temperature at low load (100 ° C.) to the first temperature at high load (80 ° C.). When the load is low, the fuel consumption can be improved by about 3% by setting the coolant temperature to the second temperature (100 ° C.) with good combustion efficiency. Furthermore, knocking can also be prevented by rapidly lowering the cooling water temperature to the first temperature (80 ° C.) during high load (acceleration).

(Modification of the first embodiment)
As shown in FIG. 10, the engine water cooling device 1a ′ according to the modification of the first embodiment differs from the water cooling device 1a according to the first embodiment (see FIG. 1) in the position of the adjustment valve 11. Since the other structure of water cooling device 1a 'of this modification is the same as the water cooling device 1a of 1st Embodiment, those overlapping description is abbreviate | omitted.

The adjustment valve 11 of this modification is also a three-way valve arranged downstream of the pump 10 on the first flow path 31. However, the adjustment valve 11 of the first embodiment is disposed at the branch point of the second flow path 30 on the first flow path 31, whereas the adjustment valve 11 of the present modification example has the first flow path 31. It is arranged at the junction with the upper third flow path 32. The adjustment valve 11 is an electronically controlled thermostat, and controls the mixing ratio of the cooling water from the pump 10 and the cooling water from the third flow path 32 based on a signal from a controller (not shown) to 2 and / or the flow rate of the cooling water flowing to the radiator 3 is controlled. The adjustment valve 11 of the present modification controls the flow rate of the cooling water that flows to the radiator 3 downstream of the radiator 3.

The warm-up control of the engine 2 by the water cooling device 1a 'is different from the warm-up control in the first embodiment in the processes of steps S14 and S22 (see FIG. 4) related to the adjustment valve 11. Also in this modified example, since the whole warm-up control is performed according to the flowchart shown in FIG. 4, only different steps S14 and S22 will be described below.

In step S14, the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), and the heater switch is off (NO in step S11). Therefore, heat is not radiated from the radiator 3 and the heater core 4, and the cooling water is made higher than the first temperature (80 ° C.) earlier. That is, as shown in FIG. 11, the electromagnetic valve 25 is closed (step S12) and the pump 10 is stopped (step S13). Furthermore, the adjusting valve 11 closes the third flow path 32 (at its downstream end) based on the control signal from the controller (step S14).

On the other hand, in step S22, the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), and the heater switch is on (YES in step S11). Therefore, heat is not dissipated in the radiator 3 and the cooling water is made higher than the first temperature (80 ° C.) earlier. That is, the electromagnetic valve 25 is opened (step S20: heat is dissipated by the heater core 4 because the heater switch is on), and the pump 10 is operated (step S21). Furthermore, the adjusting valve 11 closes the third flow path 32 (at its downstream end) based on the control signal from the controller (step S22).

Further, the normal control (after warming up) by the water cooling device 1a 'differs from the normal control in the first embodiment in the processes of steps S114 and S122 (see FIG. 7) related to the adjustment valve 11. Also in this modification, the entire normal control is performed according to the flowchart shown in FIG. 7, and therefore only different steps S114 and S122 will be described below.

In step S114, the engine 2 is in a low load state during idling (YES in step S110) or because the change in throttle opening is small (YES in step S111). For this reason, the pump 10 controls the flow rate of the cooling water to be small (step S113), suppresses heat radiation in the heater core 4 and the radiator 3, and raises the cooling water temperature to the second temperature (100 ° C.). Further, the valve opening of the adjustment valve 11 is adjusted based on a control signal from the controller, and the flow rate of the cooling water flowing through the radiator 3 is adjusted at the downstream end of the third flow path 32 (step S114). In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are relatively reduced (FIG. 12). reference). The adjusting valve 11 also allows cooling water from the pump 10 to flow into the engine 2.

On the other hand, in step S122, the change in throttle opening is large (NO in step S111), and the engine 2 is in a high load state. For this reason, the pump 10 controls the circulating flow of the cooling water to a large extent (step S121), promotes heat radiation in the heater core 4 and the radiator 3, and sets the cooling water temperature to the first temperature (80 ° C.). That is, the valve opening of the adjustment valve 11 is adjusted based on the control signal from the controller, the flow path from the first flow path 31 is closed, and the valve opening at the downstream end of the third flow path 32 is fully opened. (Step S122), the cooling water flows only through the second flow path 30, the radiator 3, and the third flow path 32 (see FIG. 13).

The same effect as that of the water cooling device 1a of the first embodiment can also be realized by the water cooling device 1a 'of the present modification configured as described above.

(Second Embodiment)
As shown in FIG. 14, in the engine water cooling device 1 b according to the second embodiment, the pump 10 (electric water pump P ₁ ) in the water cooling device 1 a (see FIG. 1) of the first embodiment is driven by the engine 2. The pump 12 is replaced with an engine drive pump P ₂ . Therefore, according to the pump 12 of the present embodiment, the flow rate of the cooling water changes according to the engine speed. Since the other structure of the water cooling device 1b of this embodiment is the same as the water cooling device 1a of 1st Embodiment, those overlapping description is abbreviate | omitted.

Hereinafter, warm-up control of the engine 2 by the water cooling device 1b will be described with reference to the flowchart shown in FIG.

If the heater switch is not on (NO in step S11), the controller transmits a control signal to the adjustment valve 11 and the electromagnetic valve 25 so that the coolant temperature becomes higher than the first temperature (80 ° C.) earlier. Here, since the heater switch is off, there is no need to flow cooling water through the heater core 4. Therefore, the solenoid valve 25 on the upstream side of the heater core 4 is closed based on the control signal from the controller (step S12). Further, as shown in FIG. 16, the second flow path 30 is also closed by the adjustment valve 11 (step S <b> 14 described later), and the cooling water is not allowed to flow to the radiator 3. As a result, heat is not dissipated in the radiator 3 and the heater core 4, and the cooling water is made higher than the first temperature (80 ° C.) earlier.

Subsequent to step S12, the adjusting valve 11 closes the second flow path 30 (at its upstream end) based on a control signal from the controller (step S14). Since the second flow path 30 is closed, heat is not radiated by the radiator 3, and a decrease in the coolant temperature during the warm-up control can be prevented. After step S14, the process flow returns to step S10. When the cooling water temperature becomes higher than the first temperature (80 ° C.) (NO in step S10), the process proceeds to normal control (step S30).

Following step S20, the adjustment valve 11 closes the second flow path 30 based on the control signal from the controller (step S22). Since the second flow path 30 is closed, heat is not radiated by the radiator 3, and a decrease in the coolant temperature during the warm-up control can be prevented. Although heat is dissipated in the heater core 4 for heating, heat is not dissipated in the radiator 3, and the cooling water becomes higher than the first temperature (80 ° C.) earlier. After step S22, the process flow returns to step S10. When the cooling water temperature becomes higher than the first temperature (80 ° C.) (NO in step S10), the process proceeds to normal control (step S30).

Next, normal control (after warming up) of the engine 2 by the water cooling device 1b will be described with reference to the flowchart shown in FIG.

First, it is determined whether or not the engine 2 is idling (step S110). If the engine is not idling (NO in step S110), it is determined whether or not the change in throttle opening is small in order to determine the operating state of the engine 2 (step S111).

When the change in throttle opening is small, that is, when the engine 2 is in a low load state (YES in step S111), the controller controls the adjusting valve 11 and the electromagnetic valve 25 so that the cooling water temperature becomes the second temperature (100 ° C.). A control signal is transmitted to. As shown in FIG. 3A, when the engine 2 is in a low load state, the fuel efficiency is better when the coolant temperature is the second temperature (100 ° C.) higher than the first temperature (80 ° C.). Therefore, the cooling water temperature is set to the second temperature (100 ° C.).

Subsequent to step S112, the degree of solution of the adjustment valve 11 is adjusted based on the control signal from the controller, and the flow rate of the cooling water flowing through the radiator 3 is adjusted at the upstream end of the second flow path 30 (step S114). In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are relatively reduced (FIG. 18). reference). The adjustment valve 11 also flows the cooling water from the pump 12 to the engine 2.

On the other hand, if the change in throttle opening is large in step S111, that is, if the engine 2 is in a high load state (NO in step S111), the controller adjusts the adjustment valve so that the cooling water temperature becomes the first temperature (80 ° C.). 11 and the electromagnetic valve 25 are transmitted with control signals. As shown in FIG. 3B, when the engine 2 is in a high load state, the fuel efficiency is better when the cooling water temperature is the first temperature (80 ° C.) lower than the second temperature (100 ° C.). The cooling water temperature is set to the first temperature (80 ° C.).

Specifically, since the warm-up has been completed, the electromagnetic valve 25 is opened based on the control signal from the controller in order to circulate the cooling water through the heater core 4 as in step S112 described above (step S112). S120). Subsequent to step 120, the valve opening of the adjustment valve 11 is adjusted based on a control signal from the controller, the flow path to the first flow path 31 connected to the engine 2 is closed, and the second flow path 30. Is opened fully (step S122), and cooling water flows only through the second flow path 30 (similar to FIG. 9; however, pump 12 instead of pump 10). In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are increased. The cooling water flows to the engine 2 after flowing through the second flow path 30, the radiator 3, and the third flow path 32. As a result, heat dissipation in the radiator 3 is promoted, and the cooling water temperature is lowered to the first temperature (80 ° C.).

The same effect as that of the water cooling device 1a of the first embodiment can be realized by the water cooling device 1b of the present embodiment configured as described above.

(Modification of the second embodiment)
As shown in FIG. 19, the engine water cooling device 1 b ′ according to the modification of the second embodiment is different from the water cooling device 1 b (see FIG. 14) according to the second embodiment in the position of the adjustment valve 11. The other configuration of the water cooling device 1b ′ of the present modification is the same as that of the water cooling device 1b of the second embodiment, and thus redundant description thereof is omitted.

The adjustment valve 11 of this modification is also a three-way valve arranged downstream of the pump 12 on the first flow path 31. However, the adjustment valve 11 of the second embodiment is disposed at the branching point of the second flow path 30 on the first flow path 31, whereas the adjustment valve 11 of the present modification example has the first flow path 31. It is arranged at the junction with the upper third flow path 32. The adjustment valve 11 is an electronically controlled thermostat, and controls the mixing ratio of the cooling water from the pump 12 and the cooling water from the third flow path 32 based on a signal from a controller (not shown) to 2 and / or the flow rate of the cooling water flowing to the radiator 3 is controlled. The adjustment valve 11 of the present modification controls the flow rate of the cooling water that flows to the radiator 3 downstream of the radiator 3.

The warm-up control of the engine 2 by the water cooling device 1b 'is different from the warm-up control in the second embodiment in steps S14 and S22 (see FIG. 15) regarding the adjustment valve 11. Also in this modified example, since the whole warm-up control is performed according to the flowchart shown in FIG. 15, only different steps S14 and S22 will be described below.

In step S14, the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), and the heater switch is off (NO in step S11). Therefore, heat is not radiated from the radiator 3 and the heater core 4, and the cooling water is made higher than the first temperature (80 ° C.) earlier. That is, as shown in FIG. 20, the electromagnetic valve 25 is closed (step S12), and the adjustment valve 11 closes the third flow path 32 (at its downstream end) based on the control signal from the controller ( Step S14).

On the other hand, in step S22, the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), and the heater switch is on (YES in step S11). Therefore, heat is not dissipated in the radiator 3 and the cooling water is made higher than the first temperature (80 ° C.) earlier. That is, the electromagnetic valve 25 is opened (step S20: the heater switch is turned on to dissipate heat in the heater core 4), and the adjustment valve 11 opens the third flow path 32 (on the downstream end thereof) based on the control signal from the controller. (Step S22).

Further, the normal control (after warming up) by the water cooling device 1b 'is different from the normal control in the second embodiment in the processes of steps S114 and S122 (see FIG. 17) related to the adjustment valve 11. Also in this modification example, the entire normal control is performed according to the flowchart shown in FIG. 17, and therefore only different steps S114 and S122 will be described below.

In step S114, the engine 2 is in a low load state during idling (YES in step S110) or because the change in throttle opening is small (YES in step S111). For this reason, the adjustment valve 11 controls the flow rate of the cooling water to the radiator 3 to be small, suppresses the heat radiation at the radiator 3, and raises the cooling water temperature to the second temperature (100 ° C.). That is, the valve opening of the adjustment valve 11 is adjusted based on the control signal from the controller, and the flow rate of the cooling water flowing through the radiator 3 is adjusted at the downstream end of the third flow path 32 (step S114). In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are relatively reduced (FIG. 21). reference). The adjustment valve 11 also allows cooling water from the pump 12 to flow into the engine 2.

On the other hand, in step S122, the change in throttle opening is large (NO in step S111), and the engine 2 is in a high load state. For this reason, the adjustment valve 11 controls the flow rate of the cooling water to the radiator 3 to increase the heat dissipation in the radiator 3 and sets the cooling water temperature to the first temperature (80 ° C.). That is, the valve opening of the adjustment valve 11 is adjusted based on the control signal from the controller, the flow path from the first flow path 31 is closed, and the valve opening at the downstream end of the third flow path 32 is fully opened. (Step S122), the cooling water flows only through the second flow path 30, the radiator 3, and the third flow path 32 (similar to FIG. 13; however, the pump 12 instead of the pump 10).

Even with the water cooling device 1b ′ of the present modification configured as described above, it is possible to achieve the same effect as the water cooling device 1b of the second embodiment, that is, the same effect as the water cooling device 1a of the first embodiment. it can.

(Third embodiment)
As shown in FIG. 22, the engine water cooling device 1 c according to the third embodiment has a configuration in which an on / off valve 13 is added to the water cooling device 1 b (see FIG. 14) of the second embodiment. One side (outflow side) of the on / off valve 13 is connected to the fifth flow path 22 (upstream side of the pump 12), and the other side (inflow side) is the first flow path 31 (downstream side of the pump 12 and adjustment). It is connected to the upstream side of the valve 11. The on / off valve 13 adjusts the flow rate of the cooling water to the adjustment valve 11 (that is, the engine 2). Since the other structure of the water cooling device 1c of this embodiment is the same as the water cooling device 1b of 2nd Embodiment, those overlapping description is abbreviate | omitted.

Hereinafter, warm-up control of the engine 2 by the water cooling device 1c will be described with reference to a flowchart shown in FIG.

If the heater switch is not on (NO in step S11), the controller sends control signals to the adjustment valve 11, the electromagnetic valve 25, and the on / off valve 13 so that the cooling water temperature becomes higher than the first temperature (80 ° C.) earlier. Send. Here, since the heater switch is off, there is no need to flow cooling water through the heater core 4. Therefore, the solenoid valve 25 on the upstream side of the heater core 4 is closed based on the control signal from the controller (step S12). Furthermore, as shown in FIG. 24, the second flow path 30 is also closed by the adjustment valve 11 (step S <b> 16 described later), and the cooling water is not allowed to flow to the radiator 3. As a result, heat is not dissipated in the radiator 3 and the heater core 4, and the cooling water is made higher than the first temperature (80 ° C.) earlier.

Following step S12, the on / off valve 13 is opened based on the control signal from the controller (step S15). When the on / off valve 13 is opened, as shown in FIG. 24, the cooling water is recirculated from the downstream side (high pressure side) of the pump 12 to the upstream side (low pressure side), and is supplied to the regulating valve 11 (ie, the engine 2). The flow rate of the cooling water is reduced. By reducing the flow rate to the engine 2, the cooling water temperature in the engine 2 absorbs the heat of the engine 2 and quickly rises to a temperature with good thermal efficiency.

Subsequent to step S15, the adjustment valve 11 closes the second flow path 30 (at its upstream end) based on the control signal from the controller (step S16). Since the second flow path 30 is closed, heat is not radiated by the radiator 3, and a decrease in the coolant temperature during the warm-up control can be prevented. After step S16, the process flow returns to step S10. When the cooling water temperature becomes higher than the first temperature (80 ° C.) (NO in step S10), the process proceeds to normal control (step S30).

Following step S20, the on / off valve 13 is closed based on the control signal from the controller (step S23). When the on / off valve 13 is closed, the cooling water is not recirculated, and the flow rate of the cooling water to the regulating valve 11 (that is, the engine 2) is not reduced.

Following step S23, the adjustment valve 11 closes the second flow path 30 based on the control signal from the controller (step S24). Since the second flow path 30 is closed, heat is not radiated by the radiator 3, and a decrease in the coolant temperature during the warm-up control can be prevented. Although heat is dissipated in the heater core 4 for heating, heat is not dissipated in the radiator 3, and the cooling water becomes higher than the first temperature (80 ° C.) earlier. After step S24, the process flow returns to step S10. When the coolant temperature becomes higher than the first temperature (80 ° C.) (NO in step S10), the process proceeds to normal control (step S30).

Next, normal control (after warming up) of the engine 2 by the water cooling device 1c will be described with reference to the flowchart shown in FIG.

When the change in throttle opening is small, that is, when the engine 2 is in a low load state (YES in step S111), the controller controls the adjusting valve 11 and the electromagnetic valve 25 so that the cooling water temperature becomes the second temperature (100 ° C.). The control signal is transmitted to the on / off valve 13. As shown in FIG. 3A, when the engine 2 is in a low load state, the fuel efficiency is better when the cooling water temperature is the second temperature (100 ° C.) higher than the first temperature (80 ° C.). The cooling water temperature is set to the second temperature (100 ° C.).

Following step S112, the on / off valve 13 is closed based on the control signal from the controller (step S115). When the on / off valve 13 is closed, the cooling water is not recirculated, and the flow rate of the cooling water to the regulating valve 11 (that is, the engine 2) is not reduced.

Subsequent to step S115, the valve opening of the adjustment valve 11 is adjusted based on a control signal from the controller, and the flow rate of the cooling water flowing through the radiator 3 is adjusted at the upstream end of the second flow path 30 (step S116). ). In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are relatively reduced (FIG. 26). reference). The adjustment valve 11 also flows the cooling water from the pump 12 to the engine 2.

On the other hand, if the change in throttle opening is large in step S111, that is, if the engine 2 is in a high load state (NO in step S111), the controller adjusts the adjustment valve so that the cooling water temperature becomes the first temperature (80 ° C.). 11. Control signals are transmitted to the electromagnetic valve 25 and the on / off valve 13. As shown in FIG. 3B, when the engine 2 is in a high load state, the fuel efficiency is better when the cooling water temperature is the first temperature (80 ° C.) lower than the second temperature (100 ° C.). The cooling water temperature is set to the first temperature (80 ° C.).

Specifically, since the warm-up has been completed, the electromagnetic valve 25 is opened based on the control signal from the controller in order to circulate the cooling water through the heater core 4 as in step S112 described above (step S112). S120). Subsequent to step 120, the on / off valve 13 is closed based on a control signal from the controller (step S123). When the on / off valve 13 is closed, the cooling water is not recirculated, and the flow rate of the cooling water to the regulating valve 11 (that is, the engine 2) is not reduced. Since the flow rate of the cooling water to the regulating valve 11 (that is, the engine 2) is not reduced, the flow rate of the cooling water circulating in the cooling device 1c is controlled to be large. Increasing the flow rate promotes heat dissipation in the radiator 3, and the cooling water temperature is kept at the first temperature (80 ° C.) by suppressing the rise (the next step for the flow of cooling water to the radiator 3 (It will be described in S124).

Subsequent to step S123, the valve opening of the adjusting valve 11 is adjusted based on a control signal from the controller, the flow path to the first flow path 31 connected to the engine 2 is closed, and the second flow path 30 The valve opening at the upstream end is fully opened (step S124), and the cooling water flows only through the second flow path 30, the radiator 3, and the third flow path 32. In order to promote heat dissipation in the radiator 3 and set the cooling water temperature to the first temperature (80 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are increased. The cooling water flows to the engine 2 after flowing through the second flow path 30, the radiator 3, and the third flow path 32. As a result, heat dissipation in the radiator 3 is promoted, and the cooling water temperature is lowered to the first temperature (80 ° C.).

Also by the water cooling device 1c of this embodiment configured as described above, the same effect as the water cooling device 1b of the second embodiment, that is, the same effect as the water cooling device 1a of the first embodiment can be realized. .

(Modification of the third embodiment)
As shown in FIG. 27, the engine water cooling device 1c ′ according to the modification of the third embodiment differs from the engine water cooling device 1c according to the third embodiment (see FIG. 22) in the position of the adjustment valve 11. Since the other structure of water cooling device 1c 'of this modification is the same as the water cooling device 1c of 3rd Embodiment, those overlapping description is abbreviate | omitted.

The adjustment valve 11 of this modification is also a three-way valve arranged downstream of the pump 12 on the first flow path 31. However, the adjustment valve 11 of the third embodiment is disposed at the branching point of the second flow path 30 on the first flow path 31, whereas the adjustment valve 11 of the present modification example has the first flow path 31. It is arranged at the junction with the upper third flow path 32. The adjustment valve 11 is an electronically controlled thermostat, and controls the mixing ratio of the cooling water from the pump 12 and the cooling water from the third flow path 32 based on a signal from a controller (not shown) to 2 and / or the flow rate of the cooling water flowing to the radiator 3 is controlled. The adjustment valve 11 of the present modification controls the flow rate of the cooling water that flows to the radiator 3 downstream of the radiator 3.

The warm-up control of the engine 2 by the water cooling device 1c 'is different from the warm-up control in the third embodiment in steps S16 and S24 (see FIG. 23) regarding the adjustment valve 11. Also in this modified example, since the whole warm-up control is performed according to the flowchart shown in FIG. 23, only different steps S16 and S24 will be described below.

In step S16, the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), and the heater switch is off (NO in step S11). Therefore, heat is not radiated from the radiator 3 and the heater core 4, and the cooling water is made higher than the first temperature (80 ° C.) earlier. That is, as shown in FIG. 28, the electromagnetic valve 25 is closed (step S12) and the on / off valve 13 is opened (step S15). Furthermore, the regulating valve 11 closes the third flow path 32 (at its downstream end) based on the control signal from the controller (step S16).

On the other hand, in step S26, the cooling water temperature is equal to or lower than the first temperature (80 ° C.) (YES in step S10), and the heater switch is on (YES in step S11). Therefore, heat is not dissipated in the radiator 3 and the cooling water is made higher than the first temperature (80 ° C.) earlier. That is, the electromagnetic valve 25 is opened (step S20: heat is dissipated by the heater core 4 because the heater switch is on), and the on / off valve 13 is closed (step S23). Furthermore, the adjusting valve 11 closes the third flow path 32 (at its downstream end) based on the control signal from the controller (step S26).

Further, the normal control (after warming up) by the water cooling device 1c 'is different from the normal control in the third embodiment in steps S116 and S124 (see FIG. 25) related to the adjustment valve 11. Also in this modified example, since the entire normal control is performed according to the flowchart shown in FIG. 25, only different steps S116 and S124 will be described below.

In step S116, the engine 2 is in a low load state during idling (YES in step S110) or because the change in throttle opening is small (YES in step S111). For this reason, the adjustment valve 11 controls the flow rate of the cooling water to the radiator 3 to be small, suppresses the heat radiation at the radiator 3, and raises the cooling water temperature to the second temperature (100 ° C.). That is, the valve opening of the adjustment valve 11 is adjusted based on a control signal from the controller, and the flow rate of the cooling water flowing through the radiator 3 is adjusted at the downstream end of the third flow path 32 (step S116). In order to suppress the heat radiation in the radiator 3 and set the cooling water temperature to the second temperature (100 ° C.), the flow rates to the second flow path 30, the radiator 3 and the third flow path 32 are relatively reduced (FIG. 29). reference). The adjustment valve 11 also allows cooling water from the pump 12 to flow into the engine 2.

On the other hand, in step S124, the throttle opening change is large (NO in step S111), and the engine 2 is in a high load state. For this reason, the adjustment valve 11 controls the circulating flow rate of the cooling water to the radiator 3 to increase the heat dissipation in the radiator 3 and brings the cooling water temperature to the first temperature (80 ° C.). That is, the valve opening of the adjustment valve 11 is adjusted based on the control signal from the controller, the flow path from the first flow path 31 is closed, and the valve opening at the downstream end of the third flow path 32 is fully opened. (Step S124), the cooling water flows only through the second flow path 30, the radiator 3, and the third flow path 32.

Even with the water cooling device 1c ′ of the present embodiment configured as described above, the same effects as the water cooling device 1c of the third embodiment, that is, the water cooling device 1a of the first embodiment and the water cooling device 1b of the second embodiment. The same effect can be realized.

(Other embodiments)
The present invention is not limited to the embodiment described above. For example, in the normal control described above, the operating state (low load state or high load state) of the engine 2 is determined based on the change in the throttle opening. However, the operating state of the engine 2 may be determined based on the vehicle speed, the throttle opening acceleration, or a combination thereof. Specifically, if the throttle opening acceleration is large, it is determined that the load is high, and if the acceleration is small, it is determined that the load is low.

In the above embodiment, the first temperature is 80 ° C. and the second temperature is 100 ° C., but the first temperature may be 70 ° C., and similarly, the second temperature is 90 ° C. There may be. The first temperature may be any temperature that is lower than the second temperature and that provides optimum combustion efficiency when the engine 2 is in a high load state. The second temperature may be any temperature that is higher than the first temperature and that provides optimum combustion efficiency when the engine 2 is in a low load state.

It should be understood that the present invention includes various modifications, and the present invention is limited only by the invention specifying matters in the scope of claims reasonable from the above disclosure.

Claims

An engine water cooling device for cooling an internal combustion engine with cooling water,
A radiator that cools the cooling water by heat exchange between the cooling water and air;
A first flow path for allowing the cooling water to flow into the engine;
A second flow path branched from the first flow path and allowing the cooling water to flow into the radiator;
A third flow path for allowing the cooling water from the radiator to flow into the first flow path downstream of a branch point from the first flow path of the second flow path;
An adjustment valve disposed on the first flow path for controlling the flow rate of the cooling water flowing through the radiator;
A pump disposed on the first flow path and circulating the cooling water to the engine and / or the radiator;
The adjustment valve is configured to allow the cooling water from the radiator to flow into the first flow path when opened.
The engine water cooling device according to claim 1,
When the temperature of the cooling water that provides optimum combustion efficiency when the engine is in a high load state is the first temperature,
The adjustment valve closes a flow path passing through the second flow path, the radiator, and the third flow path when the temperature of the cooling water in the engine is equal to or lower than the first temperature.
The engine water cooling device according to claim 1 or 2,
The pump is an electric pump that can be operated independently of the operation of the engine.
The engine water cooling device according to any one of claims 1 to 3,
The temperature of the cooling water that provides optimal combustion efficiency when the engine is in a high load state is a first temperature, and the temperature of the cooling water that provides optimal combustion efficiency when the engine is in a low load state is a second temperature that is higher than the first temperature. Then,
When the temperature of the cooling water in the engine is higher than the first temperature and the change in the throttle opening that adjusts the intake air amount to the engine is small, the adjustment valve adjusts the water temperature of the cooling water. The flow rate of the cooling water to the flow path passing through the second flow path, the radiator, and the third flow path is adjusted so as to be the second temperature.
The engine water cooling device according to any one of claims 1 to 4,
When the temperature of the cooling water that provides optimum combustion efficiency when the engine is in a high load state is the first temperature,
When the temperature of the cooling water in the engine is higher than the first temperature and the change in the throttle opening for adjusting the intake air amount to the engine is large,
The adjustment valve increases the flow rate of the cooling water to the flow path passing through the second flow path, the radiator, and the third flow path so that the temperature of the cooling water becomes the first temperature.
The engine water cooling device according to any one of claims 1 to 5,
The water-cooled engine is disposed so as to be inclined so that the exhaust side faces downward.