Vehicular heat accumulating system

A heat accumulating unit includes an upstream heat accumulator and a downstream heat accumulator each accommodating a supercooling heat accumulating material. Each of the upstream heat accumulator and the downstream heat accumulator has a channel in which fluid flows. In heat accumulation of the supercooling heat accumulating material, the channel of the upstream heat accumulator and the channel of the downstream heat accumulator are set in a serial connection state by a serial connection pipe. In a temperature rise mode, fluid that has passed through the channel of the upstream heat accumulator flows in a bypass pipe.

TECHNICAL FIELD

The present invention relates to a vehicular heat accumulating system mounted on a vehicle including a heat source.

BACKGROUND

An automobile generally includes a cooling water circuit for cooling an engine. The cooling water circuit includes, for example, a radiator for cooling engine cooling water flowing in a water jacket of the engine and a heater core for heating air-conditioning air by engine cooling water.

In recent years, there has been an increasing demand for quickly warming an engine after cold start in order to enhance fuel efficiency and promote exhaust gas purification. Japanese Patent Application Publication No. 2004-239591 describes that a supercooling heat accumulation device as well as the radiator and the heater core is connected to the cooling water circuit. The supercooling heat accumulation device includes a supercooling heat accumulating material, and a heat accumulator tank storing the supercooling heat accumulating material. The supercooling heat accumulating material has a property that does not solidify and has latent heat of solidification while being in a liquid-phase state to enter a supercooling state even at a temperature of a melting point or less and that quickly solidifies and rapidly emits a large quantity of latent heat of solidification when the supercooling state is canceled by a specific external stimulus. While the supercooling heat accumulating material quickly emits heat, the temperature of the supercooling heat accumulating material is maintained at a melting point of the supercooling heat accumulating material.

In Japanese Patent Application Publication No. 2004-239591, during operation of the engine, engine cooling water is caused to flow into a tube in the heat accumulator tank in a heat accumulating mode so that heat of engine cooling water is accumulated in the supercooling heat accumulating material, and in a quick engine warming mode, the supercooling state of the supercooling heat accumulating material is canceled by an ultrasonic trigger device so that the supercooling heat accumulating material emits latent heat of solidification. This latent heat of solidification is transferred to engine cooling water flowing by way of the supercooling heat accumulation device to thereby quickly increase the temperature of engine cooling water.

SUMMARY

A typical supercooling heat accumulating material is liquid in supercooling and is solidified by emitting latent heat of solidification. In heat accumulation, the supercooling heat accumulating device melts from the solid state and becomes liquid, but does not generate heat unless the entire amount of the supercooling heat accumulating material melts. Accordingly, in the case of Japanese Patent Application Publication No. 2004-239591, the supercooling heat accumulating material starts accumulating heat after the temperature of engine cooling water has reached a melting point or more of the supercooling heat accumulating material.

To enhance an engine warm-up effect in the quick engine warming mode, the amount of the supercooling heat accumulating material, that is, the total amount of accumulated heat, needs to be at a certain level or more. Thus, in the heat accumulating mode, a sufficient heat accumulation time is needed to change the entire amount of the supercooling heat accumulating material to a liquid state for heat accumulation. In consideration of use conditions of an automobile, however, the automobile stops after short-period traveling before the entire amount of the supercooling heat accumulating material becomes liquid, and accordingly, the engine as a heat source stops in some cases, and the frequency of this stop is not low. In this case, the supercooling heat accumulating material does not dissipate heat even by heat generation operation, and no quick engine warm-up effect can be obtained.

To obtain the quick engine warm-up effect, reduction of the amount of the supercooling heat accumulating material may be effective. However, this reduction would not achieve an engine warm-up effect in the quick engine warming mode as described above. Thus, reduction of the amount of the supercooling heat accumulating material is preferably avoided.

In view of this, it may be effective to use a plurality of heat accumulator tanks whose size is reduced to reduce the capacity of the supercooling heat accumulating material in each heat accumulator tank so that a predetermined total amount of the supercooling heat accumulating material is obtained. In the case of providing a plurality of heat accumulator tanks, if engine cooling water is caused to flow into the tanks in parallel in the heat accumulating mode, the problem described above occurs. Thus, engine cooling water needs to be caused to flow into the tanks in series. Accordingly, with reduction of the amount of the supercooling heat accumulating material stored in each heat accumulator tank, the supercooling heat accumulating material in a heat accumulator tank located upstream in a flow direction of engine cooling water completely melts so that heat generation operation of the heat accumulator tank can be performed.

However, in the case of performing heat generation operation in order to expect quick engine warm-up at next engine start after an automobile is stopped after short-period driving, the upstream supercooling heat accumulating material dissipates heat so that the temperature of engine cooling water can be temporarily increased. However, while this engine cooling water flows in a downstream heat accumulator tank, heat of the engine cooling water is taken by the supercooling heat accumulating material stored in the downstream heat accumulator tank. This heat dissipation loss reduces the temperature of engine cooling water before the engine cooling water flows into the engine. Consequently, the quick engine warm-up effect significantly decreases.

Other examples of the device requiring a quick engine warm-up effect include an automatic transmission, as well as the engine. The automatic transmission, for example, also has similar problems.

It is therefore an object of the present invention to obtain a heat dissipation effect of a supercooling heat accumulating material even after a short heat accumulation time with an enhanced warm-up effect by the supercooling heat accumulating material obtained by reducing a heat dissipation loss.

To achieve the object, according to the present invention, an upstream heat accumulator and a downstream heat accumulator each storing a supercooling heat accumulating material are provided, and the upstream heat accumulator and the downstream heat accumulator operate as a series circuit in heat accumulation, whereas fluid flows while bypassing the downstream heat accumulator in heat dissipation.

In a first aspect, in a vehicular heat accumulating system including a circulation circuit in which fluid circulates, the circulation circuit includes a heat accumulating unit that accumulates heat from the fluid or dissipates heat to the fluid, the heat accumulating unit includes an upstream heat accumulator, the upstream heat accumulator accommodating a supercooling heat accumulating material, having a channel in which the fluid flows, configured to enable heat exchange between the fluid flowing in the channel and the supercooling heat accumulating material, disposed at an upstream side in a flow direction of the fluid, a downstream heat accumulator, the downstream heat accumulator accommodating a supercooling heat accumulating material, having a channel in which the fluid flows, configured to enable heat exchange between the fluid flowing in the channel and the supercooling heat accumulating material, disposed at a downstream side in the flow direction of the fluid, a serial connection pipe connecting the channel of the upstream heat accumulator and the channel of the downstream heat accumulator to each other in series, a bypass pipe configured to cause the fluid that has flowed in the channel of the upstream heat accumulator to bypass the channel of the downstream heat accumulator, a pipe switching section configured to perform switching between the serial connection pipe and the bypass pipe, a supercooling cancel device configured to cancel a supercooling state of the supercooling heat accumulating material, and a control device configured to control the pipe switching section and the supercooling cancel device, the control device causes the supercooling cancel device to cancel the supercooling state of the supercooling heat accumulating material so that a temperature rise mode in which a temperature of a warming target is increased, if the supercooling heat accumulating material is in the supercooling state and a temperature rise of the warming target is requested, and the control device controls the pipe switching section such that the channel of the upstream heat accumulator and the channel of the downstream heat accumulator are set in a serial connection state by the serial connection pipe in heat accumulation of the supercooling heat accumulating material, and the fluid that has passed through the upstream heat accumulator flows in the bypass pipe in the temperature rise mode.

With this configuration, while fluid circulates in the circulation circuit, the heat accumulating unit takes heat from the fluid to thereby accumulate heat. In heat accumulation, the pipe switching section causes the channel of the upstream heat accumulator and the channel of the downstream heat accumulator are connected in series by the serial connection pipe, and thus, after fluid has flowed in the channel of the upstream heat accumulator, the fluid flows in the channel of the downstream heat accumulator. Accordingly, the supercooling heat accumulating material of the upstream heat accumulator tends to melt more quickly to be in a supercooling state than the supercooling heat accumulating material of the downstream heat accumulator. Thus, even in a case where the heat source is an engine and stops in a short time after cold start, for example, the supercooling heat accumulating material of the upstream heat accumulator can be set in the supercooling state.

If a temperature rise of a warming target is requested, the supercooling cancel device cancels the supercooling state of the supercooling heat accumulating material of the upstream heat accumulator, and the heat accumulating unit is switched from the heat accumulating mode to the temperature rise mode. In the temperature rise mode, the pipe switching section causes fluid that has flowed in the upstream heat accumulator to flow in the bypass pipe. At this time, since the supercooling heat accumulating material of the upstream heat accumulator dissipates latent heat of solidification, fluid flowing in the channel of the upstream heat accumulator takes heat and increases in temperature. Accordingly, the warm-up effect is enhanced. On the other hand, if the heat accumulation time is short, the supercooling heat accumulating material of the downstream heat accumulator does not reach the supercooling state in some cases. In such cases, the supercooling heat accumulating material of the downstream heat accumulator does not dissipate heat, but since fluid does not flow in the channel of the downstream heat accumulator, latent heat is not taken from the fluid, and a heat dissipation loss can be reduced accordingly.

In a second aspect, the heat accumulating unit may include a heat dissipation completion detecting section that detects completion of heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator, and the control device may control the pipe switching section such that the fluid that has flowed in the channel of the upstream heat accumulator flows in the bypass pipe until the heat dissipation completion detecting section detects completion of heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator, whereas when the heat dissipation completion detecting section detects completion of heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator, the fluid that has flowed in the channel of the upstream heat accumulator flows in the channel of the downstream heat accumulator.

With this configuration, since fluid takes heat until heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed, it is possible to prevent fluid from flowing in the channel of the downstream heat accumulator where a heat dissipation loss might occur. On the other hand, when heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed, fluid flows in the channel of the downstream heat accumulator. At this time, if the heat accumulating material of the downstream heat accumulator is in the state of enabling heat dissipation, the fluid takes heat from this supercooling heat accumulating material so that the temperature of the fluid increases. The heat dissipation completion detecting section can individually perform detection of heat dissipation completion of the supercooling heat accumulating material of the upstream heat accumulator and detection of heat dissipation completion of the supercooling heat accumulating material of the downstream heat accumulator.

In a third aspect, the pipe switching section may be disposed between the upstream heat accumulator and the downstream heat accumulator.

Specifically, the presence of the pipe switching section increases an outer surface area, and accordingly, a heat dissipation loss occurs from this area. In heat dissipation of the supercooling heat accumulating material, the temperature of fluid before flowing into the downstream heat accumulator through the upstream heat accumulator is supposed to be lower than the temperature of fluid at an outlet side of the downstream heat accumulator. The pipe switching section is provided not at the outlet side of the downstream heat accumulator where fluid having a relatively high temperature flows but in a portion between the upstream heat accumulator and the downstream heat accumulator where fluid having a relatively low temperature flows so that a loss in heat dissipation due to an increase in the outer surface area can be thereby reduced.

In a fourth aspect, the pipe switching section may be disposed downstream of the channel of the downstream heat accumulator.

Specifically, the presence of the pipe switching section increases an outer surface aera, and accordingly, a heat dissipation loss occurs from this area. In heat accumulation of the supercooling heat accumulating material, the temperature of fluid that has flowed out of the downstream heat accumulator through the upstream heat accumulator is considered to be lower than the temperature of fluid at the inlet side of the upstream heat accumulator or the temperature of fluid flowing between the upstream heat accumulator and the downstream heat accumulator. Since the pipe switching section is provided in a portion where fluid having a relatively low temperature flows, a loss in heat accumulation due to an increase in the outer surface area can be reduced. The pipe switching section may be constituted by, for example, a motor-operated valve.

In a fifth aspect, the heat dissipation completion detecting section may be configured to determine that dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed when a temperature difference of the fluid between an inlet side and an outlet side of the channel of the upstream heat accumulator becomes smaller than a predetermined value.

That is, while the supercooling heat accumulating material of the upstream heat accumulator dissipates heat, a fluid temperature difference between the inlet side and the outlet side of the channel of the upstream heat accumulator is large. This temperature difference decreases as the amount of heat dissipation of the supercooling heat accumulating material decreases, and when heat dissipation of the supercooling heat accumulating material is completed, the temperature difference decreases below a predetermined value. Thus, it is reliably detected whether heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed or not.

In a sixth aspect, the supercooling cancel device may be disposed in each of the upstream heat accumulator and the downstream heat accumulator, and configured to cancel the supercooling state of the supercooling heat accumulating material of the upstream heat accumulator and the supercooling state of the supercooling heat accumulating material of the downstream heat accumulator individually.

With this configuration, the supercooling state of each of the supercooling heat accumulating material of the upstream heat accumulator and the supercooling heat accumulating material of the downstream heat accumulator can be canceled at an appropriate timing.

In a seventh aspect, the control device may cause the supercooling cancel device to cancel the supercooling state of the supercooling heat accumulating material of the upstream heat accumulator when a heat source changes from a state where no heat is generated to a state where heat is generated, and cause the supercooling cancel device to cancel the supercooling state of the supercooling heat accumulating material of the downstream heat accumulator when the heat dissipation completion detecting section detects completion of heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator.

With this configuration, heat dissipation of the supercooling heat accumulating material of the downstream heat accumulator starts after dissipation of the supercooling heat accumulating material of the upstream heat accumulator has been completed, and thus, the quantity of heat accumulated in the supercooling heat accumulating material of the upstream heat accumulator and the quantity of heat accumulated in the supercooling heat accumulating material of the downstream heat accumulator are supplied to fluid.

In an eighth aspect, the heat accumulating unit may include a first heat accumulator and a second heat accumulator, and a wall portion of a part of the first heat accumulator may be shared by a wall portion of the second heat accumulator.

With this configuration, the wall portion of a part of the first heat accumulator and the wall portion of the second heat accumulator are shared. Thus, the area of heat dissipation to the outside decreases in the temperature rise mode, and efficiency in warming fluid by the supercooling heat accumulating material increases. In addition, the number of parts can be reduced, and the size of the heat accumulating unit can be reduced.

In a ninth aspect, the heat accumulating unit may include a first heat accumulator and a second heat accumulator, and a gap may be provided between the first heat accumulator and the second heat accumulator.

With this configuration, heat transfer between the first heat accumulator and the second heat accumulator is reduced. Thus, the time before completion of heat accumulation of the supercooling heat accumulating material of the first heat accumulator can be shortened.

In the first aspect, the upstream heat accumulator and the downstream heat accumulator each accommodating the supercooling heat accumulating material are provided, and the upstream heat accumulator and the downstream heat accumulator operate as a series circuit in heat accumulation, whereas fluid is caused to flow while bypassing the downstream heat accumulator in heat dissipation. Thus, in the case of accumulating heat by using the supercooling heat accumulating material, even if the heat accumulation time is short, a heat dissipation effect can be obtained after the short heat accumulation time. In addition, a heat dissipation loss is reduced so that the effect of warming the warming target with the supercooling heat accumulating material can be thereby enhanced.

In the second aspect, fluid that has flowed in the channel of the upstream heat accumulator is caused to flow in the bypass pipe until heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed, whereas when heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed, fluid that has passed in the channel of the upstream heat accumulator is caused to flow in the channel of the downstream heat accumulator. Thus, the effect of warming the warming target can be further enhanced.

In the third aspect, since the pipe switching section is disposed between the upstream heat accumulator and the downstream heat accumulator, a loss in heat dissipation due to the presence of the pipe switching section can be reduced.

In the fourth aspect, since the pipe switching section is disposed downstream of the channel of the downstream heat accumulator, a loss in heat accumulation due to the presence of the pipe switching section can be reduced.

In a fifth aspect, it is reliably detected whether heat dissipation of the supercooling heat accumulating material of the upstream heat accumulator is completed or not based on the fluid temperature difference between the inlet side and the outlet side of the channel of the upstream heat accumulator.

In the sixth aspect, the supercooling state of each of the supercooling heat accumulating material of the heat accumulator and the supercooling heat accumulating material of the downstream heat accumulator can be canceled at an appropriate timing.

In the seventh aspect, it is possible to ensure supply of the quantity of heat accumulated in the supercooling heat accumulating material of the upstream heat accumulator and the quantity of heat accumulated in the supercooling heat accumulating material of the downstream heat accumulator to the fluid.

In the eighth aspect, by sharing the wall portion of a part of the first heat accumulator and the wall portion of the second heat accumulator, efficiency of warming fluid in the temperature rise mode can be enhanced so that the fluid temperature can be increased early. In addition, the number of parts constituting the heat accumulating unit can be reduced, and the size of the heat accumulating unit can be reduced.

In the ninth aspect, since the gap is provided between the first heat accumulator and the second heat accumulator, heat transfer between the first heat accumulator and the second heat accumulator is reduced so that the time before completion of heat accumulation of the supercooling heat accumulating material of the first heat accumulator can be shortened, and heat dissipation effect can be sufficiently obtained after the short heat accumulation time.

DETAILED DESCRIPTION

Embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are merely preferred examples in nature, and are not intended to limit the invention, applications, and use of the applications.

FIG.1is a schematic view illustrating an overall configuration of a vehicular heat accumulating system1according to an embodiment of the present invention. A vehicle on which the vehicular heat accumulating system1is mounted is an automobile including an engine2, and also includes an automatic transmission3, a vehicular air-conditioning device4, a radiator5, and so forth, as well as the engine2.

The engine2is mounted in an engine room (not shown) disposed in a front portion of the automobile, and generates a driving force for driving wheels of the automobile. Although not shown, an electric generator may be driven by the engine2so that electric power generated by the electric generator is supplied to a motor and the wheels are driven by an output of the motor. The automobile may be a so-called hybrid vehicle configured to travel by both an output of the engine2and an output of the motor. The automobile may be a plug-in type hybrid vehicle. The engine2generates heat during driving, and thus, corresponds to a heat source of the vehicle. The motor and an inverter device for controlling the motor, for example, also generate heat, and thus, can be heat sources. A plurality of heat sources may be provided.

The engine2includes a water jacket2ain which engine cooling water (coolant) as cooling fluid flows. The engine2includes, for example, a water pump2b, an engine cooling water control valve2c, and a thermostat2d. The water pump2bis used for feeding engine cooling water to flow in the water jacket2a. The water pump2bmay be driven by a rotary force of a crankshaft or may be driven by an unillustrated electric motor. The cooling water control valve2cis used for changing a flow rate of engine cooling water circulated by the water pump2b. As illustrated inFIG.3, the engine cooling water control valve2cis connected to a control device7described later, and is controlled by the control device7in accordance with, for example, a temperature of engine cooling water.

The thermostat2dis a valve that is closed when engine cooling water flowing in the water jacket2ais less than a predetermined temperature so that engine cooling water does not flow to the radiator5, and is open when engine cooling water is at the predetermined temperature or more so that engine cooling water flows to the radiator5. The predetermined temperature in this case is a temperature at which engine cooling water needs to be cooled by the radiator5, and may be set at about 80° C. to 90° C., for example.

The engine2includes an engine oil pump2efor feeding engine oil to flow in an oil passage2fdisposed in the engine2. The engine2includes an engine oil supply pipe P10and an engine oil discharge pipe P11. An upstream end of the engine oil supply pipe P10is connected to an outlet of the engine oil pump2e. A downstream end of the engine oil supply pipe P10is connected to an oil inlet of an engine oil heat exchanger30described later. An upstream end of the engine oil discharge pipe P11is connected to an oil outlet of the engine oil heat exchanger30. A downstream end of the engine oil discharge pipe P11is connected to the oil passage2fof the engine2. Accordingly, engine oil that has flowed out of the oil passage2fflows from the engine oil supply pipe P10in an oil channel formed in the engine oil heat exchanger30and returns to the oil passage2ffrom the engine oil discharge pipe P11.

The engine2is provided with an engine cooling water temperature sensor2gfor detecting a temperature of engine cooling water. The engine cooling water temperature sensor2gis configured to detect a temperature of engine cooling water flowing in the water jacket2a, for example. As illustrated inFIG.3, the engine cooling water temperature sensor2gis connected to the control device7, and outputs the detected engine cooling water temperature to the control device7.

(Configuration of Automatic Transmission3)

The automatic transmission3is a so-called automatic gear-shift device, and receives a driving force output from the crankshaft of the engine2. The driving force received by the automatic transmission3is decelerated with deceleration gears or accelerated with acceleration gears, and is output from the automatic transmission3. The automatic transmission3accommodates oil called automatic transmission fluid (ATF). The automatic transmission3includes an ATF pump3afor feeding ATF. Although not shown, the automatic transmission3may be replaced by a continuously variable transmission (CVT).

The automatic transmission3includes an ATF feed pump P20and an ATF discharge pipe P21. An upstream end of the ATF feed pump P20is connected to an outlet of the ATF pump3a. A downstream end of the ATF feed pump P20is connected to an oil inlet of an ATF heat exchanger31described later. An upstream end of the ATF discharge pipe P21is connected to an oil outlet of the ATF heat exchanger31. A downstream end of the ATF discharge pipe P21is connected to the body of the automatic transmission3. Accordingly, ATF that has flowed out of the automatic transmission3flows through an ATF channel in the ATF heat exchanger31from the ATF feed pump P20, and returns to the automatic transmission3from the ATF discharge pipe P21.

The automatic transmission3is provided with an ATF temperature sensor3bfor detecting a temperature of ATF. The ATF temperature sensor3bis configured to detect a temperature of ATF in the automatic transmission3, for example. As illustrated inFIG.3, the ATF temperature sensor3bis connected to the control device7, and outputs the detected ATF temperature to the control device7.

(Overall Configuration of Vehicular Heat Accumulating System1)

The vehicular heat accumulating system1includes a circulation circuit A in which engine cooling water circulates, and the control device7illustrated inFIG.3. The circulation circuit A includes the water jacket2a, the water pump2b, the cooling water control valve2c, and the thermostat2dof the engine2, the radiator5, a heater core17, the engine oil heat exchanger30, the ATF oil heat exchanger31, and a heat accumulating unit40.

The circulation circuit A also includes a heater core supply pipe P1extending from the water jacket2ato the heater core17, a radiator supply pipe P2extending from an outlet side of the thermostat2dto the radiator5, a radiator discharge pipe P3extending from an outlet side of the radiator5to an inlet side of the engine cooling water control valve2c, a heater core discharge pipe P4extending from an outlet side of the heater core17to an intermediate portion of the radiator discharge pipe P3, an engine oil heat exchanger supply pipe P5extending from the water jacket2ato a cooling water inlet side of the engine oil heat exchanger30, a heat accumulating unit supply pipe P6extending from a cooling water outlet side of the engine oil heat exchanger30to a cooling water inlet side of the heat accumulating unit40, an ATF oil heat exchanger supply pipe P7extending from a cooling water outlet side of the heat accumulating unit40to a cooling water inlet side of the ATF oil heat exchanger31, and a heat exchanger discharge pipe P8extending from a cooling water outlet side of the ATF oil heat exchanger31to an intermediate portion of the radiator discharge pipe P3. The heater core discharge pipe P4and the radiator discharge pipe P3are connected to each other. The heat exchanger discharge pipe P8and the radiator discharge pipe P3are connected to each other. The circulation circuit A may have a configuration other than the unillustrated configuration. For example, the engine oil heat exchanger30may be provided when necessary, and may be omitted.

When warming of the engine2is completed and the engine cooling water temperature increases, the thermostat2dis opened. When the thermostat2dis opened, engine cooling water flows in the radiator supply pipe P2from the water jacket2a, and enters the radiator5from an inlet of the radiator5to enable heat exchange with external air. Engine cooling water that has flowed out of an outlet of the radiator5is fed by the water pump2bsuch that the engine cooling water flows in the radiator discharge pipe P3to enter an inlet of the engine cooling water control valve2cand returns to the water jacket2athrough the engine cooling water control valve2cand the water pump2b.

The water pump2bcauses engine cooling water in the water jacket2ato be supplied from the heater core supply pipe P1to an inlet of the heater core17and enter the heater core17. The engine cooling water that has entered the heater core17can exchange heat with air-conditioning air. Engine cooling water that has flowed out of an outlet of the heater core17flows in the heater core discharge pipe P4to enter the radiator discharge pipe P3, and returns to the water jacket2athrough the engine cooling water control valve2cand the water pump2b.

The water pump2balso causes engine cooling water in the water jacket2ato be supplied from the engine oil heat exchanger supply pipe P5to a cooling water inlet of the engine oil heat exchanger30and enter the engine oil heat exchanger30. In the engine oil heat exchanger30, since the oil passage is formed in the engine oil heat exchanger30and engine oil flows in this oil passage as described above, heat exchange can be performed between this oil passage and engine cooling water flowing in the engine oil heat exchanger30. In an example configuration enabling heat exchange, a tube, for example, in which engine cooling water flows is provided in the engine oil heat exchanger30and an oil passage is formed such that engine oil flows along the outer surface of the tube, for example. For example, if the temperature of engine cooling water is higher than the temperature of engine oil, the engine oil takes heat from the engine cooling water so that the temperature of the engine oil rises.

Engine cooling water that has flowed out of a cooling water outlet of the engine oil heat exchanger30flows into a channel of engine cooling water in the heat accumulating unit40from the heat accumulating unit supply pipe P6. The heat accumulating unit40will be described later. Engine cooling water that has flowed out of the cooling water outlet side of the heat accumulating unit40is supplied from the ATF oil heat exchanger supply pipe P7to the cooling water inlet of the ATF oil heat exchanger31and enters the ATF oil heat exchanger31. In the ATF oil heat exchanger31, the oil passage is formed therein and ATF flows in this oil passage as described above. Thus, heat exchange can be performed between the ATF and engine cooling water flowing in the ATF oil heat exchanger31. In an example configuration enabling heat exchange, a tube in which engine cooling water flows, for example, is provided in the ATF oil heat exchanger31and an oil passage is formed such that ATF flows along the outer surface of the tube.

Here, if the temperature of engine cooling water is higher than the temperature of ATF, the ATF takes heat from the engine cooling water so that the temperature of the ATF rises. The ATF oil heat exchanger31is a heat exchanger that takes heat from engine cooling water and increases the temperature of ATF as a warming target. The automatic transmission3can also be a warming target. Engine cooling water that has flowed out of a cooling water outlet of the ATF oil heat exchanger31flows in the heat exchanger discharge pipe P8to enter the radiator discharge pipe P3, and returns to the water jacket2a.

The vehicular air-conditioning device4illustrated inFIG.2is configured such that both air in a cabin (indoor air) and air outside the cabin (outdoor air) are introduced therein and subjected to temperature adjustment and then supplied to portions of the cabin. The vehicular air-conditioning device4includes an air-conditioning casing10and an air-conditioning control section7a(shown inFIG.3). The air-conditioning casing10is housed in an instrument panel (not shown) disposed in a front end portion of the cabin, for example. The air-conditioning casing10includes an air supply casing11, a temperature adjustment section12, and an air discharge direction switching section13that are arranged in this order from an upstream side to a downstream side in an airflow direction. The air supply casing11has an outdoor air inlet11aand an indoor air inlet11b. The outdoor air inlet11acommunicates with the outside of the cabin through an unillustrated intake duct, for example, and introduces air outside the cabin (outdoor air). The indoor air inlet11bis open inside the instrument panel, introduces air in the cabin (indoor air), and allows the air to circulate in the cabin. The amount of outdoor air introduced from the outdoor air inlet11ais an outdoor air introduction amount. The amount of indoor air introduced from the indoor air inlet11bis an indoor air circulation amount.

In the air supply casing11, an indoor/outdoor air switching damper11cthat opens and closes the outdoor air inlet11aand the indoor air inlet11bis disposed. The indoor/outdoor air switching damper11cis constituted by, for example, a cantilever damper or a rotary damper each made of, for example, a plate-shaped member, and supported to be pivotable with respect to a side wall of the air supply casing11. The indoor/outdoor air switching damper11cmay be constituted by, for example, an unillustrated film damper.

The indoor/outdoor air switching damper11cis driven to be at an intended pivot angle by an indoor/outdoor air switching actuator (indoor/outdoor air switching damper driving section)11d. Accordingly, an intake mode is switched. The indoor/outdoor air switching actuator11dis controlled in a manner described above by the air-conditioning control section7aof the control device7.

For example, as illustrated by solid lines inFIG.2, when the indoor/outdoor air switching damper11cpivots such that the outdoor air inlet11ais fully closed and the indoor air inlet11bis fully opened, the intake mode changes to an indoor air circulation mode. It is assumed that the opening degree of the indoor/outdoor air switching damper11cat this time is 100%. On the other hand, as illustrated by imaginary lines inFIG.2, when the indoor/outdoor air switching damper11cpivots such that the outdoor air inlet11ais fully opened and the indoor air inlet11bis fully closed, the intake mode changes to an outdoor air introduction mode. It is assumed that the opening degree of the indoor/outdoor air switching damper11cat this time is 0%. While the opening degree of the indoor/outdoor air switching damper11cis between 1% to 99%, both the outdoor air inlet11aand the indoor air inlet11bare open so that both indoor air and outdoor air are introduced to the temperature adjustment section12. This intake mode is an indoor/outdoor air mixed mode. In the indoor/outdoor air mixed mode, an introduction ratio of indoor air and outdoor air is changed in accordance with the opening degree of the indoor/outdoor air switching damper11c. Accordingly, the outdoor air introduction amount and the indoor air circulation amount change.

The air supply casing11is provided with an air blower15. The air blower15includes a fan15aand a blower motor15bfor driving the fan15a. At least one of indoor air or outdoor air is introduced to the air supply casing11by rotation of the fan15a, and then is sent to the temperature adjustment section12provided below the air supply casing11. The blower motor15bis configured to adjust the rotation speed per a unit time by changing a voltage to be applied to the blower motor15b. The air blow rate changes in accordance with the rotation speed of the blower motor15b. The blower motor15bis controlled by the air-conditioning control section7aof the control device7.

The temperature adjustment section12is a section for adjusting the temperature of air-conditioning air introduced from the air supply casing11. In the temperature adjustment section12, a cooling heat exchanger16, a heating heat exchanger17, and an air-mix door18are disposed. Specifically, a cold air passage R1is formed at an upstream side in the airflow direction in the temperature adjustment section12, and the cold air passage R1houses the cooling heat exchanger16. A lower side of the cold air passage R1is branched into a warm air passage R2and a bypass passage R3, and the warm air passage R2houses a heater core (heating heat exchanger)17. The cooling heat exchanger16may be constituted by, for example, a refrigerant evaporator such as a heat pump device. However, the present invention is not limited to this example, and the cooling heat exchanger16only needs to cool air.

The air-mix door18is disposed between the cooling heat exchanger16and the heater core17, and opens and closes an upstream end of the warm air passage R2and an upstream end of the bypass passage R3. The air-mix door18can be constituted by, for example, a plate-shaped member, and is supported to be pivotable with respect to a side wall of the temperature adjustment section12. The air-mix door18is driven to be at an intended pivot angle by an air-mix actuator18a. The air-mix actuator18ais controlled by the air-conditioning control section7aof the control device7.

When the air-mix door18fully opens the upstream end of the warm air passage R2and fully closes the upstream end of the bypass passage R3, the entire amount of cold air generated in the cold air passage R1flows in the warm air passage R2to be heated, and thus, warm air flows into the air discharge direction switching section13. On the other hand, when the air-mix door18fully closes the upstream end of the warm air passage R2and fully opens the upstream end of the bypass passage R3, the entire amount of cold air generated in the cold air passage R1flows into the bypass passage R3, and thus, cold air flows into the air discharge direction switching section13. While the air-mix door18is in a pivot position in which the air-mix door18opens the upstream end of the warm air passage R2and the upstream end of the bypass passage R3, a mixture of cold air and warm air flows into the air discharge direction switching section13. The amount of cold air and the amount of warm air flowing into the air discharge direction switching section13are changed in accordance with the pivot position of the air-mix door18so that conditioned air having an intended temperature is generated. The air-mix door18is not limited to the plate-shaped door described above, and may have any structure as long as the amount of cold air and the amount of warm air can be changed. The air-mix door18may be, for example, a rotary door, a film door, or a louver damper. The structure for temperature adjustment does not need to be the structure described above, and only needs to be a structure capable of changing the amount of cold air and the amount of warm air.

The air discharge direction switching section13is a section for supplying conditioned air subjected to temperature adjustment in the temperature adjustment section12, to portions of the cabin. The air discharge direction switching section13includes a defroster outlet opening21, a vent outlet opening22, and a heat outlet opening23. The defroster outlet opening21is connected to a defroster nozzle24formed in the instrument panel. The defroster outlet opening21is used for supplying conditioned air to a cabin inner surface of a front window pane (not shown). In the defroster outlet opening21, a defroster door21ais provided for opening and closing the defroster outlet opening21.

The vent outlet opening22is connected to a vent nozzle25formed in the instrument panel. The vent nozzle25is used for supplying conditioned air to the upper body of a passenger on a front seat, and provided at each of a center portion and the left and right sides of the instrument panel in the vehicle width direction. In the vent outlet opening22, a vent door22afor opening and closing the vent outlet opening22is provided.

The heat outlet opening23is connected to a heat duct26extending to the vicinity of the feet of a passenger. The heat duct26is used for supplying conditioned air to the feet of a passenger. In the heat outlet opening23, a heat door23afor opening and closing the heat outlet opening23is provided.

The defroster door21a, the vent door22a, and the heat door23aare driven by an air discharge direction switching actuator27, and are opened and closed. The air discharge direction switching actuator2is controlled by the air-conditioning control section7aof the control device7. The defroster door21a, the vent door22a, and the heat door23ainteract with one another through an unillustrated linkage, are switched to an intended air discharge mode among a plurality of air discharge modes such as a defroster mode in which the defroster door21ais open and the vent door22aand the heat door23aare closed, a vent mode in which the defroster door21aand the heat door23aare closed and the vent door22ais open, a heat mode in which the defroster door21aand the vent door22aare closed and the heat door23ais opened, a def-vent mode in which the defroster door21aand the vent door22aare open and the heat door23ais closed, and a bi-level mode in which the defroster door21aand the heat door23aare open and the vent door22ais closed.

(Configuration of Heat Accumulating Unit40)

As illustrated inFIG.1, the heat accumulating unit40is disposed upstream of the ATF oil heat exchanger31in the flow direction of engine cooling water. The heat accumulating unit40is configured to take heat from engine cooling water and accumulate heat in a supercooling heat accumulating material when engine cooling water is at a predetermined temperature or more. The supercooling heat accumulating material does not solidify and remains in a liquid-phase state and has latent heat of solidification to enter a supercooling state even at a temperature less than or equal to a melting point, and rapidly releases a large amount of latent heat of solidification. During the rapid discharge of heat, the temperature of the supercooling heat accumulating material is kept at a melting point of the supercooling heat accumulating material. As such a supercooling heat accumulating material, a conventionally known material, such as materials disclosed in Japanese Patent Application Publication No. 2004-239591 (sodium acetate trihydrate, and erythritol (meso-erythritol)), may be used.

Specifically, as illustrated inFIG.6, the heat accumulating unit40includes a first heat accumulator41, a second heat accumulator42, a switching valve43, and a bypass pipe B1. The first heat accumulator41is disposed upstream of the second heat accumulator42in the flow direction of engine cooling water. Thus, the first heat accumulator41is an upstream heat accumulator of the present invention, and the second heat accumulator42is a downstream heat accumulator of the present invention. Although the bypass pipe B1is disposed between the first heat accumulator41and the second heat accumulator42inFIG.6, the bypass pipe B1may be disposed in a position except for the position between the first heat accumulator41and the second heat accumulator42. In this case, as illustrated inFIG.4, the heat accumulating unit40is constituted without any gap present between the first heat accumulator41and the second heat accumulator42.

As illustrated inFIG.4, the first heat accumulator41includes a first accommodation space41afor accommodating a supercooling heat accumulating material, and a first channel41bin which engine cooling water flows. The first channel41bis located between the first accommodation spaces41aand41a, and engine cooling water flowing in the first channel41band the supercooling heat accumulating material can exchange heat. The first channel41bis formed to extend upward and downward. The number of first accommodation spaces41aand the number of first channels41bmay be one or more. The first heat accumulator41is mounted on the vehicle such that an upper portion inFIG.4is located above, but the present invention is not limited to this example. The configuration may be changed depending on layout. In the description of this embodiment, the upper side and the lower side are defined for convenience of description, but may be changed in accordance with the direction in which the heat accumulating unit40is mounted. With respect to the flow direction of engine cooling water, the upper side of the first heat accumulator41is an upstream side, the lower side of the first heat accumulator41is a downstream side, a lower side of the second heat accumulator42is an upstream side, and the upper side of the second heat accumulator42is a downstream side. A portion to contact the supercooling heat accumulating material is coated with a known resin in order to prevent corrosion by the supercooling heat accumulating material.

The second heat accumulator42is configured in a manner similar to the first heat accumulator41, and includes a second accommodation space42afor accommodating a supercooling heat accumulating material and a second channel42bin which engine cooling water flows. The first heat accumulator41and the second heat accumulator42may be disposed side by side horizontally. In this embodiment, a part of a wall portion of the first heat accumulator41of the heat accumulating unit40may be shared by a wall portion of the second heat accumulator42. That is, a wall portion41cof the first heat accumulator41toward the second heat accumulator42is a wall portion defining the first accommodation space41a. The wall portion41cdefines the second accommodation space42alocated in the second heat accumulator42toward the first heat accumulator41. Thus, the first accommodation space41aof the first heat accumulator41and the second accommodation space42aof the second heat accumulator42are adjacent to each other with the wall portion41cinterposed therebetween. Since a part of the wall portion41cof the first heat accumulator41and the wall portion of the second heat accumulator42are shared, the area of heat dissipation to the outside decreases, and efficiency in warming engine cooling water by the supercooling heat accumulating material increases. In addition, the number of parts can be reduced, and the size of the heat accumulating unit40can be reduced.

The first heat accumulator41is provided with a first upper pipe41dconnected to an upper side of the first channel41band a first lower pipe41econnected to a lower side of the first channel41b. In the flow direction of engine cooling water, the first upper pipe41dis an upstream pipe, and the first lower pipe41eis a downstream pipe. As illustrated inFIG.6, an upper side of the first upper pipe41dis connected to a downstream side of the heat accumulating unit supply pipe P6. The second heat accumulator42is provided with a second upper pipe42dconnected to an upper side of the second channel42band a second lower pipe42econnected to a lower side of the second channel42b. In the flow direction of engine cooling water, the second upper pipe42dis a downstream pipe, and the second lower pipe42eis an upstream pipe

As illustrated inFIG.3, the heat accumulating unit40includes a heat accumulation completion detecting section44connected to the control device7. As illustrated inFIG.4, the heat accumulation completion detecting section44includes a first lower temperature sensor44adisposed in a lower portion of the first heat accumulator41, and a second lower temperature sensor44bdisposed in a lower portion of the second heat accumulator42. The first lower temperature sensor44ais a sensor for detecting a temperature of a supercooling heat accumulating material accommodated in a lower portion of the first accommodation space41a. The second lower temperature sensor44bis a sensor for detecting a temperature of a supercooling heat accumulating material accommodated in a lower portion of the second accommodation space42a. The heat accumulation completion detecting section44is configured to determine that heat accumulation of the supercooling heat accumulating material in the first heat accumulator41is completed when the temperature detected by the first lower temperature sensor44areaches a predetermined value or more. That is, while the supercooling heat accumulating material of the first heat accumulator41accumulates heat, although the phase of the supercooling heat accumulating material changes add from solid to liquid, heat is transferred from the supercooling heat accumulating material in the liquid state to an upper portion of the first heat accumulator41by natural convection. Thus, a lower portion of the first heat accumulator41has a lowest temperature. That is, when the portion of the first heat accumulator41having the lowest temperature reaches a temperature of a melting point or more, for example, it is determined that the entire supercooling heat accumulating material of the first heat accumulator41is liquefied and heat accumulation is completed. With this detection, detection accuracy at completion of heat accumulation is enhanced. The heat accumulation completion detecting section44is configured to determine that heat accumulation of the supercooling heat accumulating material of the second heat accumulator42is completed when the temperature detected by the second lower temperature sensor44breaches a predetermined value or more. The heat accumulation completion detecting section44is not limited to the configuration described above, and only needs to be configured to detect completion of heat accumulation of the supercooling heat accumulating material.

As illustrated inFIG.3, the heat accumulating unit40includes a heat dissipation completion detecting section45connected to the control device7. As illustrated inFIG.4, the heat dissipation completion detecting section45includes a first inlet/outlet temperature sensor45athat detects a temperature difference of engine cooling water between an inlet side and an outlet side of the first channel41bof the first heat accumulator41. The heat dissipation completion detecting section45determines that heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is completed when the temperature difference detected by the first inlet/outlet temperature sensor45abecomes smaller than the predetermined value. That is, while the supercooling heat accumulating material of the first heat accumulator41dissipates heat, the temperature difference of engine cooling water between the inlet side and the outlet side of the channel of the first heat accumulator41is large. This temperature difference decreases as the amount of heat dissipation of the supercooling heat accumulating material decreases, and when heat dissipation of the supercooling heat accumulating material is completed, the temperature difference decreases below the predetermined value. Thus, it is reliably detected whether heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is completed or not. The heat dissipation completion detecting section45also includes a second inlet/outlet temperature sensor45bthat detects a temperature difference of engine cooling water between the inlet side and the outlet side of the second channel42bof the second heat accumulator42. The heat dissipation completion detecting section45is configured to determine that heat dissipation of the supercooling heat accumulating material of the second heat accumulator42is completed when the temperature difference detected by the second inlet/outlet temperature sensor45bbecomes smaller than a predetermined value.

As illustrated inFIG.3, the heat accumulating unit40includes a supercooling cancel device46connected to the control device7. The supercooling cancel device46is configured to individually cancel a supercooling state of the supercooling heat accumulating material of the first heat accumulator41and a supercooling state of the supercooling heat accumulating material of the second heat accumulator42. That is, as illustratingFIG.4, the supercooling cancel device46includes a first trigger generating section46aand a second trigger generating section46b. The first trigger generating section46ais provided in the first heat accumulator41and used for canceling the supercooling state of the supercooling heat accumulating material of the first heat accumulator41. The second trigger generating section46bis provided in the second heat accumulator42, and used for canceling the supercooling state of the supercooling heat accumulating material of the second heat accumulator42.

Examples of the trigger for canceling the supercooling state include vibrations. Thus, the first trigger generating section46aand the second trigger generating section46bcan be constituted by, for example, ultrasonic wave generating devices (ultrasonic trigger devices) that continuously generate ultrasonic waves. An amplitude and a frequency may be set such that a supercooling heat accumulating material in a supercooling state nucleates, which is well known.

The supercooling cancel device46is controlled by the control device7. The control device7is configured to output any one of a control signal for actuating only the first trigger generating section46a, a control signal for actuating only the second trigger generating section46b, or a control signal for actuating both the first trigger generating section46aand the second trigger generating section46b, to the supercooling cancel device46depending on situations in a manner described later. When the supercooling cancel device46receives the control signal for actuating only the first trigger generating section46a, only the first trigger generating section46ais actuated. When the supercooling cancel device46receives the control signal for actuating only the second trigger generating section46b, only the second trigger generating section46bis actuated. When the supercooling cancel device46receives the control signal for actuating both the first trigger generating section46aand the second trigger generating section46b, both the first trigger generating section46aand the second trigger generating section46bare actuated. Thus, the supercooling states of the supercooling heat accumulating material of the first heat accumulator41and the supercooling heat accumulating material of the second heat accumulator42can be canceled at a time. The first trigger generating section46aand the second trigger generating section46bmay be united such that the supercooling states of the supercooling heat accumulating material of the first heat accumulator41and the supercooling heat accumulating material of the second heat accumulator42can be canceled at a time by a common trigger generating section.

FIG.5illustrates a part of the heat accumulating unit40according to a first variation of the first embodiment. In the heat accumulating unit40of the first variation, a gap S is provided between the first heat accumulator41and the second heat accumulator42. The presence of the gap S can reduce heat transfer between the first heat accumulator41and the second heat accumulator42.

As illustrated inFIG.6, the bypass pipe B1is a pipe for causing engine cooling water that has flowed out of the first channel41bof the first heat accumulator41to bypass the second channel42bof the second heat accumulator42. A downstream side of the first lower pipe41eof the first heat accumulator41, an upstream side of the bypass pipe B1, and an upstream side of the second lower pipe42eof the second heat accumulator42are connected to the switching valve43illustrated inFIG.6. Thus, the switching valve43is disposed between the first heat accumulator41and the second heat accumulator42.

A downstream side of the bypass pipe B1is connected to a downstream side of the second upper pipe42dof the second heat accumulator42. The downstream side of the bypass pipe B1and the downstream side of the second upper pipe42dof the second heat accumulator42are connected to an upstream side of the ATF oil heat exchanger supply pipe P7.

When the downstream side of the first lower pipe41eof the first heat accumulator41and the upstream side of the second lower pipe42eof the second heat accumulator42are connected to each other, the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42can be connected in series. Thus, the first lower pipe41eof the first heat accumulator41and the second lower pipe42eof the second heat accumulator42are a serial connection pipe B2connecting the channel of the upstream heat accumulator and the channel of the downstream heat accumulator in series according to the present invention.

The switching valve43serves as a pipe switching section for switching between the serial connection pipe B2and the bypass pipe B1, is constituted by an electric channel switching valve device known to date, and is connected to the control device7. The control device7controls the switching valve43to perform switching between a bypass state shown inFIG.6(a)and a serial connection state shown inFIG.6(b). As illustrated inFIG.6(a), when the switching valve43causes the first lower pipe41eof the first heat accumulator41to communicate with the bypass pipe B1, causes the first lower pipe41eof the first heat accumulator41to non-communicate with the second lower pipe42eof the second heat accumulator42, and causes the bypass pipe B1to non-communicate with the second lower pipe42eof the second heat accumulator42, a bypass state is established. The control device7can output a control signal to the switching valve43to obtain the bypass state. In the bypass state, engine cooling water that has flowed out of the first channel41bof the first heat accumulator41flows in the first lower pipe41e, the switching valve43, and the bypass pipe B1to enter the ATF oil heat exchanger supply pipe P7.

On the other hand, as illustrated inFIG.6(b), when the switching valve43causes the first lower pipe41eof the first heat accumulator41to communicate with the second lower pipe42eof the second heat accumulator42, causes the first lower pipe41eof the first heat accumulator41to non-communicate with the bypass pipe B1, and causes the second lower pipe42eof the second heat accumulator42to non-communicate with the bypass pipe B1, a serial connection state is established. The control device7can output a control signal to the switching valve43to obtain the serial connection state. In the serial connection state, engine cooling water that has flowed out of the first channel41bof the first heat accumulator41flows in the first lower pipe41e, the switching valve43, the second lower pipe42eof the second heat accumulator42, the second channel42b(shown inFIG.5), and the second upper pipe42d, and enters the ATF oil heat exchanger supply pipe P7.

FIG.7illustrates a second variation of the first embodiment. In the second variation, the location of the switching valve43is changed. Specifically, the switching valve43is disposed downstream of the second channel42bof the second heat accumulator42in the flow direction of engine cooling water. To this switching valve43, the downstream side of the bypass pipe B1, a downstream side of the second upper pipe42dof the second heat accumulator42, and the upstream side of the ATF oil heat exchanger supply pipe P7are connected. The upstream side of the bypass pipe B1is connected to the downstream side of the first lower pipe41eof the first heat accumulator41and the upstream side of the second lower pipe42eof the second heat accumulator42. The downstream side of the first lower pipe41eof the first heat accumulator41is connected to the upstream side of the second lower pipe42eof the second heat accumulator42.

The control device7controls the switching valve43to perform switching between a bypass state shown inFIG.7(a)and a serial connection state shown inFIG.7(b). As illustrated inFIG.7(a), when the switching valve43causes the bypass pipe B1to communicate with the ATF oil heat exchanger supply pipe P7, causes the bypass pipe B1to non-communicate with the second upper pipe42dof the second heat accumulator42, and causes the second upper pipe42dof the second heat accumulator42to non-communicate with the ATF oil heat exchanger supply pipe P7, a bypass state is established. The control device7can output a control signal to the switching valve43to obtain the bypass state. In the bypass state, engine cooling water that has flowed out of the first channel41bof the first heat accumulator41flows in the first lower pipe41e, the bypass pipe B1, and the switching valve43, and enters the ATF oil heat exchanger supply pipe P7.

On the other hand, as illustrated inFIG.7(b), when the switching valve43causes the second upper pipe42dof the second heat accumulator42to communicate with the ATF oil heat exchanger supply pipe P7, causes the bypass pipe B1to non-communicate with the second upper pipe42dof the second heat accumulator42, and causes the bypass pipe B1to non-communicate with the ATF oil heat exchanger supply pipe P7, a serial connection state is established. The control device7can output a control signal to the switching valve43to obtain the serial connection state. In the serial connection state, engine cooling water that has flowed out of the first channel41bof the first heat accumulator41flows in the first lower pipe41e, the second lower pipe42eof the second heat accumulator42, the second channel42b(shown inFIG.5), the second upper pipe42d, and the switching valve43, and enters the ATF oil heat exchanger supply pipe P7.

(Configuration of Control Device7)

The control device7illustrated inFIG.3is constituted by a microcomputer including a central processing unit (CPU), a RAM, a ROM, and so forth, and is configured to operate in accordance with programs. Although the control device7includes the air-conditioning control section7afor controlling the vehicular air-conditioning device4and a heat accumulation control section7bfor controlling the heat accumulating unit40in this embodiment, the air-conditioning control section7aand the heat accumulation control section7bmay be constituted by other control devices.

Air-conditioning control sensors28are connected to the air conditioning control device7. The air-conditioning control sensors28are, for example, an outdoor air temperature sensor, an indoor air temperature sensor, a solar radiation quantity sensor, or an evaporator sensor. The air-conditioning control section7aof the control device7controls the indoor/outdoor air switching actuator11d, the blower motor15b, the air-mix actuator18a, and the air discharge direction switching actuator27, for example, based on information obtained from the air-conditioning control sensors28. The indoor/outdoor air switching actuator11d, the blower motor15b, the air-mix actuator18a, and the air discharge direction switching actuator27are also controlled based on an air-conditioning operation state of a passenger.

The heat accumulation control section7bis configured such that when the supercooling heat accumulating material is in a supercooling state and a temperature rise of ATF as a warming target is requested, the heat accumulation control section7bcauses the supercooling cancel device46to cancel the supercooling state of the supercooling heat accumulating material and establishes a temperature rise mode of increasing the temperature of ATF. The heat accumulation control section7bcontrols the switching valve43such that the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42are set in the serial connection state by the serial connection pipe B2in heat accumulation of the supercooling heat accumulating material, whereas engine cooling water that has flowed in the first channel41bof the first heat accumulator41flows in the bypass pipe B1in the temperature rise mode.

The heat accumulation control section7bmay also be configured such that while the supercooling heat accumulating material of at least one of the first heat accumulator41or the second heat accumulator42of the heat accumulating unit40is in the supercooling state and a temperature rise of ATF is requested, the heat accumulation control section7bcauses the supercooling cancel device46to cancel the supercooling state of the supercooling heat accumulating material that is in the supercooling state and the temperature rise mode of increasing a warming target is established.

Whether the first heat accumulator41and the second heat accumulator4are in the supercooling states or not can be individually detected by the first lower temperature sensor44aand the second lower temperature sensor44bof the heat accumulation completion detecting section44. Specifically, the heat accumulation completion detecting section44determines that heat accumulation of the supercooling heat accumulating material of the first heat accumulator41is completed when the temperature detected by the first lower temperature sensor44areaches a predetermined value or more, and determines that heat accumulation of the supercooling heat accumulating material of the second heat accumulator42is completed when the temperature detected by the second lower temperature sensor44breaches a predetermined value or more, and these detection signals are received by the control device7so that the heat accumulation control section7bcan determine whether the first heat accumulator41and the second heat accumulator4are in the supercooling states or not.

Whether a temperature rise of ATF is requested or not can be determined by the heat accumulation control section7bbased on reception by the control device7of information on the ATF temperature output from the ATF temperature sensor3b. If the ATF temperature detected by the ATF temperature sensor3bis a low temperature less than or equal to a predetermined temperature, it is determined that a temperature rise of ATF is requested, whereas if the ATF temperature detected by the ATF temperature sensor3bis higher than the predetermined temperature, it is determined that a temperature rise of ATF is not requested. This predetermined temperature can be a temperature when warming of the automatic transmission3is completed, and can be set at a temperature between 40° C. to 60° C., for example.

Since the serial connection state (shown inFIGS.6(b) and7(b)) is established in the heat accumulating mode, while engine cooling water that has taken heat from the engine as a heat source circulates in the circulation circuit A, the engine cooling water flows in the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42in the heat accumulating unit40in this order. The supercooling heat accumulating material takes heat from engine cooling water flowing in the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42to thereby accumulate heat. In this heat accumulating mode, engine cooling water flows in the first channel41bof the first heat accumulator41located at an upstream side in the flow direction of the engine cooling water and then flows in the second channel42bof the second heat accumulator42. Thus, the supercooling heat accumulating material of the first heat accumulator41tends to melt more quickly to be in a supercooling state than the supercooling heat accumulating material of the second heat accumulator42. Thus, even in a case where the engine2stops in a short time after cold start, for example, the supercooling heat accumulating material of the first heat accumulator41can be made in a supercooling state.

In a case where an ATF temperature rise is requested, the supercooling state of the supercooling heat accumulating material of the first heat accumulator41is canceled by the supercooling cancel device46, and the heat accumulating unit40is switched from the heat accumulating mode to the temperature rise mode. In the temperature rise mode, engine cooling water flows while bypassing the second channel42bof the second heat accumulator42. At this time, since the supercooling heat accumulating material of the first heat accumulator41releases latent heat of solidification, engine cooling water flowing in the first channel41bof the first heat accumulator41takes heat and increases in temperature. Accordingly, the effect of warming ATF is enhanced. On the other hand, if the heat accumulation time is short, the supercooling heat accumulating material of the second heat accumulator42does not reach the supercooling state in some cases. In such cases, the supercooling heat accumulating material of the second heat accumulator42does not dissipate heat, but since engine cooling water does not flow in the second heat accumulator42, latent heat is not taken from the engine cooling water, and a heat dissipation loss can be reduced accordingly.

The heat accumulation control section7bmay be configured such that the heat accumulation control section7ballows engine cooling water that has flowed in the first channel41bof the first heat accumulator41to flow in the bypass pipe B1until the heat dissipation completion detecting section45detects completion of heat dissipation of the supercooling heat accumulating material of the first heat accumulator41, whereas when the heat dissipation completion detecting section45detects completion of heat dissipation of the supercooling heat accumulating material of the first heat accumulator41, the heat accumulation control section7bcontrols the switching valve43such that engine cooling water that has flowed in the first channel41bof the first heat accumulator41flows in the second channel42bof the second heat accumulator42. This control is applicable to a case where heat accumulation is completed in both the supercooling heat accumulating material of the first heat accumulator41and the supercooling heat accumulating material of the second heat accumulator42. Weather heat accumulation is completed in both the supercooling heat accumulating material of the first heat accumulator41and the supercooling heat accumulating material of the second heat accumulator42or not can be determined by the heat accumulation control section7bbased on an output of the heat accumulation completion detecting section44.

Specifically, the switching valve43is kept in a bypass state until the heat dissipation completion detecting section45detects completion of heat dissipation of the supercooling heat accumulating material of the first heat accumulator41, and the switching valve43is set in the serial connection state when completion of heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is detected. Accordingly, engine cooling water takes heat until heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is completed, and thus, it is possible to prevent engine cooling water from flowing in the second channel42bof the second heat accumulator42where a heat dissipation loss might occur. Accordingly, the temperature of ATF can be increased early. Thereafter, when heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is completed, engine cooling water flows in the second channel42bof the second heat accumulator42. At this time, if the supercooling heat accumulating material of the second heat accumulator42is in the state of enabling heat dissipation, engine cooling water takes heat from this supercooling heat accumulating material so that the temperature of the engine cooling water increases.

The heat accumulation control section7bmay also be configured such that the first trigger generating section46aof the supercooling cancel device46cancels the supercooling state of the supercooling heat accumulating material of the first heat accumulator41when the engine2as a heat source reaches the state of generating heat from the state of generating no heat, and the second trigger generating section46bof the supercooling cancel device46cancels the supercooling state of the supercooling heat accumulating material of the second heat accumulator42when the heat dissipation completion detecting section44detects completion of heat dissipation of the supercooling heat accumulating material of the first heat accumulator41. In this case, this control is applicable to the case where heat accumulation is completed in both the supercooling heat accumulating material of the first heat accumulator41and the supercooling heat accumulating material of the second heat accumulator42.

In this manner, heat dissipation of the supercooling heat accumulating material of the second heat accumulator42starts after heat dissipation of the supercooling heat accumulating material of the first heat accumulator41has been completed. Thus, both the quantity of heat accumulated in the supercooling heat accumulating material of the first heat accumulator41and the quantity of heat accumulated in the supercooling heat accumulating material of the second heat accumulator42can be supplied to engine cooling water.

Advantages of Embodiment

As described above, in the vehicular heat accumulating system1according to this embodiment, while engine cooling water that has taken heat from the engine2circulates in the circulation circuit A, the heat accumulating unit40takes heat from the engine cooling water so that heat is accumulated. In heat accumulation, the switching valve43causes the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42to be connected in series by the serial connection pipe B2so that engine cooling water flows in the second channel42bof the second heat accumulator42, after flowing in the first channel41bof the first heat accumulator41. Accordingly, the supercooling heat accumulating material of the first heat accumulator41tends to melt more quickly to be a supercooling state than the supercooling heat accumulating material of the second heat accumulator41. Thus, even in a case where the engine2stops in a short time after cold start, the supercooling heat accumulating material of the first heat accumulator41can be set in the supercooling state.

If an ATF temperature rise is requested, the supercooling state of the supercooling heat accumulating material of the first heat accumulator41is canceled by the supercooling cancel device46, and the heat accumulating unit40is switched from the heat accumulating mode to the temperature rise mode. In the temperature rise mode, the switching valve43causes engine cooling water that has flowed in the first channel41bof the first heat accumulator41to flow in the bypass pipe B1. At this time, since the supercooling heat accumulating material of the first heat accumulator41dissipates latent heat of solidification, cooling fluid flowing in the first channel41bof the first heat accumulator41takes heat and increases in temperature. Accordingly, warm-up effect is enhanced. On the other hand, if the heat accumulation time is short, the supercooling heat accumulating material of the second heat accumulator42does not reach the supercooling state in some cases. In such cases, the supercooling heat accumulating material of the second heat accumulator42does not dissipate heat, but since cooling fluid does not flow in the second channel42bof the second heat accumulator42, latent heat is not taken from the cooling fluid, and a heat dissipation loss can be reduced accordingly.

In addition, since engine cooling water takes heat until heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is completed, it is possible to prevent cooling fluid from flowing in the second channel42bof the second heat accumulator42where a heat dissipation loss might occur. On the other hand, when heat dissipation of the supercooling heat accumulating material of the first heat accumulator41is completed, engine cooling water flows in the second channel42bof the second heat accumulator42. At this time, if the supercooling heat accumulating material of the second heat accumulator42is in the state of enabling heat dissipation, engine cooling water takes heat from this supercooling heat accumulating material so that the temperature of the engine cooling water increases.

In addition, the presence of the switching valve43increases an outer surface area, and accordingly, a heat dissipation loss occurs from this area. In heat dissipation of the supercooling heat accumulating material, the temperature of cooling fluid before flowing into the second heat accumulator42through the first heat accumulator41is supposed to be lower than the temperature of the engine cooling water at the outlet side of the second heat accumulator42. The switching valve43is provided not at the outlet side of the second heat accumulator42where engine cooling water having a relatively high temperature flows but in a portion between the first heat accumulator41and the second heat accumulator42where cooling water having a relatively low temperature flows so that a loss in heat dissipation due to an increase in the outer surface area can be thereby reduced.

In heat accumulation of the supercooling heat accumulating material, the temperature of engine cooling water that has flowed out of the second heat accumulator42through the first heat accumulator41is supposed to be lower than the temperature of cooling fluid at the inlet side of the first heat accumulator41and the temperature of engine cooling water flowing between the first heat accumulator41and the downstream heat accumulator. Since the switching valve43is provided in a portion where engine cooling water having a relatively low temperature flows in heat accumulation, a loss in heat accumulation due to an increase in the outer surface area can be reduced.

In addition, as illustrated inFIG.4, a wall portion of a part of the first heat accumulator41and a wall portion of the second heat accumulator42are shared, warming efficiency of engine cooling water in the temperature rise mode can be increased so that the temperature of engine cooling water can be increased early. In addition, the number of parts constituting the heat accumulating unit40can be reduced, and the size of the heat accumulating unit40can be reduced.

As illustrated inFIG.5, since the gap S is provided between the first heat accumulator41and the second heat accumulator42, heat transfer between the first heat accumulator41and the second heat accumulator42is reduced so that the time before completion of heat accumulation of the supercooling heat accumulating material of the first heat accumulator41can be shortened, and heat dissipation effect after the short heat accumulation time can be sufficiently obtained.

Second Embodiment

FIG.8illustrates an example configuration of a vehicular heat accumulating system1according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in that a warming target is engine oil. In the following description, the same components as those of the first embodiment are denoted by the same reference characters and will not be described again, and components different from those of the first embodiment will be described in detail.

Specifically, a heat accumulating unit40is disposed between a water jacket2aand an engine oil heat exchanger30. A circulation circuit A includes a heat accumulating unit supply pipe P40extending from a water jacket2ato a heat accumulating unit40, an engine oil heat exchanger supply pipe P41extending from the heat accumulating unit40to an engine oil heat exchanger30, and an ATF oil heat exchanger supply pipe P42extending from the engine oil heat exchanger30to an ATF oil heat exchanger31. Engine cooling water that has flowed through the heat accumulating unit supply pipe P40enters a first channel41bof a first heat accumulator41and a second channel42bof a second heat accumulator42of the heat accumulating unit40. Engine cooling water that has flowed in the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42enters the engine oil heat exchanger30.

In a configuration of this second embodiment, while a supercooling heat accumulating material in at least one of the first heat accumulator41or the second heat accumulator42of the heat accumulating unit40is in a supercooling state and a temperature rise of engine oil as a warming target is requested, the supercooling state of the supercooling heat accumulating material that is in the supercooling state is canceled by the supercooling cancel device46, and a temperature rise mode of increasing the temperature of the warming target is established. The temperature rise request of engine oil can be determined by a heat accumulation control section7bby reception, by the control device7, of information on engine cooling water temperature output from an engine cooling water temperature sensor2g. This is because the engine cooling water temperature and the engine oil temperature have a correlation. If the engine cooling water temperature detected by the engine cooling water temperature sensor2gis a low temperature less than or equal to a predetermined temperature, it is determined that a temperature rise of engine oil is requested, whereas if the engine cooling water temperature of the engine cooling water temperature sensor2gis higher than the predetermined temperature, it is determined that a temperature rise of engine oil is not requested. The predetermined temperature in this case can be a temperature when warming of an engine2is completed, and can be set at a temperature between 40° C. to 60° C., for example.

In the second embodiment, advantages similar to those of the first embodiment can be obtained, and the engine2can be warmed early.

Third Embodiment

FIG.9illustrates an example configuration of a vehicular heat accumulating system1according to a third embodiment of the present invention. The third embodiment is different from the first embodiment in that a warming target is air-conditioning air to be warmed by a heater core17. In the following description, the same components as those of the first embodiment are denoted by the same reference characters and will not be described again, and components different from those of the first embodiment will be described in detail.

Specifically, a heat accumulating unit40is disposed between a water jacket2aand a heater core17. A circulation circuit A includes a heat accumulating unit supply pipe P30extending from the water jacket2ato a heat accumulating unit40, and a heater core supply pipe P31extending from the heat accumulating unit40to the heater core17. Engine cooling water that has flowed through the heat accumulating unit supply pipe P30enters a first channel41bof a first heat accumulator41and a second channel42bof a second heat accumulator42of the heat accumulating unit40. Engine cooling water that has flowed in the first channel41bof the first heat accumulator41and the second channel42bof the second heat accumulator42enters the heater core supply pipe P31.

The circulation circuit A includes an ATF oil heat exchanger supply pipe P33extending from an outlet side of an engine oil heat exchanger30to an inlet side of an ATF oil heat exchanger31.

In the configuration of the third embodiment, while a supercooling heat accumulating material in at least one of the first heat accumulator41or the second heat accumulator42of the heat accumulating unit40is in a supercooling state and a temperature rise of air-conditioning air as a warming target is requested, the supercooling state of the supercooling heat accumulating material that is in the supercooling state is canceled by the supercooling cancel device46, and a temperature rise mode of increasing the temperature of the warming target is established. A request for a temperature rise request of air-conditioning air, that is, a temperature rise of the heater core17, can be determined by a heat accumulation control section7bby reception, by the control device7, of information on engine cooling water temperature output from an engine cooling water temperature sensor2g. If the engine cooling water temperature detected by the engine cooling water temperature sensor2gis a low temperature less than or equal to a predetermined temperature, it is determined that a temperature rise of the heater core17is requested, whereas if the engine cooling water temperature of the engine cooling water temperature sensor2gis higher than the predetermined temperature, it is determined that a temperature rise of the heater core17is not requested. The predetermined temperature in this case can be a temperature at which a heating capacity requested by the air-conditioning control section7ais obtained, and can be set at a temperature between 40° C. to 60° C., for example.

In the third embodiment, advantages similar to those of the first embodiment can be obtained, and heating capacity especially in a winter season can be enhanced.

The above-described embodiments are merely examples in all respects, and should not be construed as limiting. Further, all variations and modifications belonging to the equivalent scope of the claims are within the scope of the present invention. For example, cooling fluid may be a substance except for engine cooling water, and may be cooling water of a water or cooling water of an inverter, for example.

As described above, a vehicular heat accumulating system according to the present invention is applicable to an automobile on which an automatic transmission and/or an air-conditioning device is mounted, for example.