JP6028397B2 - Vehicle heating system - Google Patents

Description

  The present invention relates to a vehicle heating apparatus, and more particularly, to a vehicle heating apparatus that recovers waste heat and heats air blown into a vehicle interior.

  In general, in a vehicle heating device, cooling water heated by an engine is supplied to a heater core, and air blown into the vehicle interior is heated by this cooling water. Such a vehicle heating device is described in Patent Document 1, for example.

JP 2003-34126 A

  By the way, in order to promote warm-up when starting the engine, it is necessary to raise the coolant temperature early. Therefore, in a general engine, during the warm-up operation, the cooling water temperature is effectively increased by bypassing the circulation path of the cooling water from the radiator. However, when the cooling water heated by the engine is used to heat the air that is blown into the passenger compartment as in the prior art described above, it takes time to increase the cooling water temperature, resulting in a decrease in the warm-up performance of the engine. there is a possibility.

  This invention is made in view of such a point, The objective is to provide the heater for vehicles which can improve heater performance effectively, preventing the warming-up performance fall of an engine. is there.

  In order to achieve the above object, a vehicle heating apparatus according to the present invention is provided in an exhaust passage of an engine, and exchanges heat between an exhaust flowing through the exhaust passage and a fluid to be circulated, and the heat A heater core that circulates the heated fluid in the exchange channel and exchanges heat between the fluid and the air blown into the vehicle interior, a fluid outlet portion of the heat exchange channel, and a fluid inlet of the heater core A first fluid flow path that connects the fluid outlet section of the heater core and a fluid inlet section of the heat exchange flow path, and the first fluid flow path or the It is provided with the pump which is provided in the 2nd fluid channel and pumps fluid.

  Further, a flow for switching an exhaust flow path provided at a branch exhaust passage formed by branching from an exhaust passage upstream of the heat exchange flow path and the exhaust passage and the branched exhaust passage. And a flow path switching valve, wherein the flow path switching valve opens the exhaust flow path when the temperature of the fluid heated in the heat exchange flow path is equal to or lower than a first upper limit threshold value that prevents boiling of the fluid. While the exhaust passage is provided with a heat exchange passage, the exhaust passage is switched to the branch exhaust passage when the temperature of the fluid heated in the heat exchange passage is higher than the first upper limit threshold. It may be a thing.

  The fluid may be cooling water for the engine, and at least a part of the second fluid flow path may be formed in a cylinder block of the engine.

  A bypass flow path that connects the first fluid flow path and the second fluid flow path positioned upstream of the cylinder block to bypass the cooling water flow path from the heater core; A bypass valve that switches the flow path of the cooling water to the heater core or the bypass flow path, and the bypass valve has a temperature that allows the temperature of the cooling water flowing into the heater core to sufficiently heat the air as a heat source for heating. If it becomes higher than the upper limit threshold of 2, the flow path of the cooling water may be switched to the bypass flow path.

  Further, an exhaust purification catalyst for purifying exhaust gas may be provided in the exhaust passage, and the heat exchange flow path may be provided in an exhaust passage downstream of the exhaust purification catalyst.

  According to the vehicle heating device of the present invention, it is possible to effectively improve the heater performance while preventing a decrease in the warm-up performance of the engine.

It is a typical whole block diagram which shows the heating apparatus for vehicles which concerns on 1st embodiment of this invention. In the first embodiment of the present invention, (a) is a diagram for explaining an exhaust passage when the exhaust passage switching valve is turned on, and (b) is an exhaust when the exhaust passage switching valve is turned off. It is a figure explaining a flow path. It is a flowchart which shows the control content which concerns on 1st embodiment of this invention. It is a typical whole block diagram which shows the heating apparatus for vehicles which concerns on 2nd embodiment of this invention. In 2nd embodiment of this invention, (a) is a figure explaining a cooling water flow path when a bypass valve is closed, (b) is a figure explaining a cooling water flow path when a bypass valve is opened. (C) is a figure explaining a cooling water flow path when a thermostat is opened. It is a flowchart which shows the control content which concerns on 2nd embodiment of this invention.

  Hereinafter, each embodiment of the heating device for vehicles concerning the present invention is described with reference to the drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[First embodiment]
First, based on FIG. 1, it demonstrates from the exhaust system of the vehicle by which the heating apparatus 20A for vehicles of 1st embodiment is mounted.

  In the exhaust system of the present embodiment, an oxidation catalyst (Diesel Oxidation Catalyst: hereinafter referred to as DOC) 12, diesel particulates, and the like are sequentially provided in an exhaust passage 11 of a diesel engine (hereinafter simply referred to as engine) 10 from the exhaust upstream side. A filter (Diesel Particulate Filter, hereinafter referred to as DPF) 13 and a selective catalytic reduction (hereinafter referred to as SCR) 14 are provided.

DOC12 generates the NO ₂ to oxidize NO in the exhaust, to NO in the exhaust to increase the proportion of NO _2, functions to raise the denitration efficiency by SCR 14.

  The DPF 13 collects particulate matter (hereinafter referred to as PM) in the exhaust gas, and when the collected amount of PM exceeds a predetermined amount, regeneration that accumulates and removes the accumulated PM is performed. The regeneration of the DPF 13 is performed by supplying unburned fuel to the DOC 12 on the upstream side of the exhaust by post-injection and increasing the exhaust temperature by heat due to oxidation.

  The SCR 14 adsorbs ammonia generated from urea water sprayed in the exhaust passage 11 by a urea water injector (not shown) and reduces and purifies NOx from the exhaust gas passing through the adsorbed ammonia.

  Next, a detailed configuration of the vehicle heating device 20A of the present embodiment will be described. The vehicle heating device 20A includes a heat exchange exhaust passage 11a, a branch exhaust passage 11b, an exhaust passage switching valve 21, a waste heat recovery heat exchange passage 22, a vehicle interior heating unit 23, and an upstream fluid. A flow path 24, a downstream fluid flow path 25, an electric pump 26, a fluid temperature sensor 27, and an electronic control unit (hereinafter referred to as ECU) 40 are provided.

  In this embodiment, the waste heat recovery heat exchange channel 22 corresponds to the heat exchange channel of the present invention, the upstream fluid channel 24 corresponds to the first fluid channel of the present invention, and the downstream side. The fluid channel 25 corresponds to the second fluid channel of the present invention.

  The heat exchange exhaust passage 11a is formed in the exhaust passage 11 on the exhaust downstream side of the SCR 14 and a silencer (not shown). In the heat exchange exhaust passage 11a, a waste heat recovery heat exchange passage 22 described later in detail is interposed.

  The branch exhaust passage 11 b is formed by branching from the exhaust passage 11 located between the SCR 14 and the waste heat recovery heat exchange passage 22. In the present embodiment, the branch exhaust passage 11b and the heat exchange exhaust passage 11a also function as a tail pipe that discharges the exhaust to the outside.

  The exhaust flow path switching valve 21 is, for example, a known butterfly valve, and is provided at a branch portion between the heat exchange exhaust passage 11a and the branch exhaust passage 11b. When the exhaust flow path switching valve 21 is turned on in response to an instruction signal input from the ECU 40, the upstream end of the branch exhaust passage 11b is closed. That is, the exhaust gas from the SCR 14 flows into the heat exchange exhaust passage 11a and is released to the outside air (see FIG. 2A). On the other hand, when the exhaust flow path switching valve 21 is turned OFF in response to an instruction signal input from the ECU 40, the upstream end of the heat exchange exhaust passage 11a is closed. That is, the exhaust gas from the SCR 14 flows into the branch exhaust passage 11b and is released to the outside air (see FIG. 2B).

  The waste heat recovery heat exchange flow path 22 exchanges heat between the fluid flowing through the flow path and the exhaust flowing through the heat exchange exhaust passage 11a, and meanders in the heat exchange exhaust passage 11a. Is formed. In the present embodiment, the waste heat recovery heat exchange flow path 22 is provided on the exhaust downstream side of the SCR 14, so that the SCR 14 becomes lower than the catalyst activation temperature due to a decrease in exhaust temperature due to waste heat recovery. Can be prevented.

  The vehicle interior heating unit 23 includes an inlet tank 23a connected to the upstream fluid passage 24, an outlet tank 23b connected to the downstream fluid passage 25, and an inlet tank 23a and an outlet tank 23b. The heater core portion 23c and a sub tank 23d as a reservoir tank connected to the inlet tank 23a are provided. The heater core 23c heats the air blown into the vehicle interior by using the fluid heated in the waste heat recovery heat exchange channel 22 and flowing from the inlet tank 23a as a heat source. The fluid that has flowed through the heater core 23c and exchanged heat with air flows into the outlet tank 23b.

  The upstream fluid passage 24 supplies the fluid heated to the vehicle interior heating unit 23 by heat exchange with the exhaust gas in the waste heat recovery heat exchange passage 22. Therefore, the upstream fluid passage 24 is connected at its upstream end to the fluid outlet portion of the waste heat recovery heat exchange passage 22 and at the downstream end to the inlet tank 23a of the vehicle interior heating unit 23. Has been.

  The downstream fluid flow path 25 allows the fluid heat-exchanged with the air in the heater core portion 23 c to flow into the heat exchange flow path 22 for waste heat recovery. For this reason, the downstream side fluid passage 25 is connected at its upstream end to the outlet tank 23b of the vehicle interior heating unit 23 and at its downstream end to the fluid inlet of the heat exchange passage 22 for waste heat recovery. Has been.

  The electric pump 26 pumps fluid and is provided in the upstream fluid flow path 24. The driving of the electric pump 26 is controlled according to an instruction signal input from the ECU 40. When the electric pump 26 is driven, the fluid to be pumped includes the waste heat recovery heat exchange channel 22, the upstream fluid channel 24, the inlet tank 23 a, the heater core 23 c, the outlet tank 23 b, and the downstream fluid channel 25. Circulates through the fluid circuit. The electric pump 26 may be provided in the downstream fluid flow path 25.

The fluid temperature sensor 27 detects the temperature of the fluid heated by heat exchange with the exhaust, and is provided in the upstream fluid flow path 24 adjacent to the fluid outlet portion of the waste heat recovery heat exchange flow path 22. ing. The fluid temperature T _WA detected by the fluid temperature sensor 27 is input to the electrically connected ECU 40.

  The ECU 40 performs various controls such as fuel injection of the engine 10, and includes a known CPU, ROM, RAM, input port, output port, and the like. In order to perform these various controls, output signals of various sensors are input to the ECU 40.

  The ECU 40 includes an electric pump drive control unit 41 and a switching valve control unit 42 as some functional elements. In the present embodiment, these functional elements are described as being included in the ECU 40, which is an integral piece of hardware. However, any one of these functional elements may be provided in separate hardware.

The electric pump drive control unit 41 controls the driving of the electric pump 26 according to the fluid temperature T _WA detected by the fluid temperature sensor 27. More specifically, the ECU 40 stores, as the heating / heating upper limit threshold T _LIM1 , a fluid temperature (for example, 50 ° C.) at which the air blown into the passenger compartment is heated by the heater core portion 23c and can be sufficiently heated. ing.

Electric pump operation control unit 41, when the fluid temperature T _WA inputted from the fluid temperature sensor 27 is below the heating heat upper threshold T _LIM1 inputs a drive instruction signal to the electric pump 26. On the other hand, when the fluid temperature T _WA inputted from the fluid temperature sensor 27 exceeds the heating heat upper threshold T _LIM1, the electric pump operation control unit 41 inputs a stop instruction signal to the electric pump 26. Thereby, it is comprised so that the useless power consumption which drives the electric pump 26 may be avoided.

The switching valve control unit 42 controls the exhaust flow path switching valve 21 according to the fluid temperature T _WA detected by the fluid temperature sensor 27. More specifically, the ECU 40 stores a temperature (for example, 80 ° C.) that prevents boiling of the fluid as the fluid temperature upper limit threshold T _LIM2 . Switching valve control unit 42, the fluid temperature T _WA inputted from the fluid temperature sensor 27 when following this fluid temperature upper threshold T _LIM2 inputs an instruction signal to the ON exhaust flow switching valve 21. That is, the upstream end of the branch exhaust passage 11b is closed, and the exhaust flows into the heat exchange exhaust passage 11a (see FIG. 2A).

On the other hand, the fluid temperature T _WA inputted from the fluid temperature sensor 27 is more than the fluid temperature upper threshold T _LIM2, switching valve control unit 42 inputs an instruction signal to the OFF exhaust flow switching valve 21. That is, the upstream end of the heat exchange exhaust passage 11a is closed, and the exhaust flows into the branch exhaust passage 11b (see FIG. 2B).

  Next, based on FIG. 3, the control flow by the vehicle heating device 20A of the present embodiment will be described. This control starts simultaneously with the start of the engine 10 (key switch ON of the ignition switch).

  In step (hereinafter, “step” is simply referred to as “S”) 100, the drive instruction signal is input from the electric pump drive control unit 41 to the electric pump 26, and at the same time, the exhaust flow path switching valve 21 is turned on from the switching valve control unit 42. An instruction signal is input. That is, the temperature of the fluid is raised by heat exchange with the exhaust gas in the waste heat recovery heat exchange passage 22, and the heated fluid flows into the vehicle interior heating unit 23 through the upstream fluid passage 24. Then, heating of the air blown into the passenger compartment is started.

In S110, the fluid temperature T _WA inputted from the fluid temperature sensor 27 whether or not reached the heating heat upper threshold T _LIM1 is determined. When the fluid temperature T _WA is equal to or lower than the heating / heating upper limit threshold T _{LIM1, the process returns to} S100, whereas when the fluid temperature T _WA exceeds the heating / heating upper limit threshold T _LIM1 , the process proceeds to S120.

In S120, upon receiving the fluid temperature T _WA has reached the heating heat upper threshold T _LIM1, in order to avoid unnecessary power consumption, stop instruction signal to the electric pump 26 is inputted from the electric pump operation control unit 41.

In S130, whether the fluid temperature T _WA inputted from the fluid temperature sensor 27 has reached the fluid temperature upper threshold T _LIM2 is determined. When the fluid temperature T _WA exceeds the fluid temperature upper limit threshold T _LIM2 , an instruction signal for turning off the exhaust flow path switching valve 21 is input from the switching valve control unit 42 in S140 in order to avoid boiling of the fluid. Control is returned.

  Next, the effect by the vehicle heating device 20A according to the present embodiment will be described.

  In a general vehicle heating apparatus, air blown into a vehicle compartment is heated using cooling water heated by an engine as a heat source. For this reason, particularly at the time of starting, there is a possibility that the heat of the cooling water is taken away by the heating air for heating and the warm-up performance of the engine is deteriorated.

  On the other hand, in the vehicle heating device 20A of the present embodiment, a fluid circuit that is separate from the cooling water circuit of the engine 10 is provided, and the air blown into the vehicle interior using the fluid heated by the exhaust heat as a heat source. Heating.

  Therefore, according to the vehicle heating device 20A of the present embodiment, the heater performance can be effectively improved without degrading the warm-up performance of the engine 10.

  Further, in the vehicle heating device 20A of the present embodiment, the waste heat recovery heat exchange flow path 22 that performs heat exchange between the exhaust and the fluid is provided on the exhaust downstream side of the SCR.

  Therefore, according to the vehicle heating device 20A of the present embodiment, the exhaust gas (NOx emission) is effectively deteriorated by avoiding that the SCR 14 is lower than the catalyst activation temperature due to a decrease in exhaust temperature due to waste heat recovery. Can be prevented.

[Second Embodiment]
Hereinafter, based on FIGS. 4-6, the heating apparatus 20B for vehicles which concerns on 2nd embodiment of this invention is demonstrated. In the second embodiment of the present invention, the fluid that heats the air blown into the passenger compartment is used as cooling water for the engine 10, and further the warming up of the engine 10 is promoted by cooling water that is heated by waste heat recovery. is there. Constituent elements having the same functions as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the vehicle heating device 20 </ b> B of the present embodiment includes a heat exchange exhaust passage 11 a, a branch exhaust passage 11 b, an exhaust passage switching valve 21, and a waste heat recovery heat exchange passage 22. The vehicle interior heating unit 23, the upstream cooling water flow path 30, the connection cooling water flow path 31, the cylinder block internal flow path 32, the water pump 33, the downstream cooling water flow path 34, and the bypass flow path 35 , A bypass valve 36, a radiator flow path 37, a coolant temperature sensor 38, and an ECU 40 are provided.

  The upstream cooling water flow path 30 supplies the cooling water heated by the heat exchange with the exhaust gas in the waste heat recovery heat exchange flow path 22 to the vehicle interior heating unit 23. For this reason, the upstream side fluid passage 24 is connected at its upstream end to the cooling water outlet of the waste heat recovery heat exchange passage 22 and at the downstream end to the inlet tank 23a of the vehicle interior heating unit 23. It is connected.

  The cooling water flow path 31 for connection allows the cooling water flowing through the vehicle interior heating unit 23 to flow into the flow path 32 in the cylinder block. For this reason, the connecting coolant passage 31 is connected at its upstream end to the outlet tank 23b of the vehicle interior heating unit 23 and at its downstream end to the coolant inlet of the cylinder block passage 32. Yes.

  The in-cylinder block flow path 32 circulates the cooling water flowing from the connection cooling water flow path 31 through a water jacket (not shown), and is formed in the cylinder block of the engine 10.

  The water pump 33 pumps and supplies cooling water, and is provided adjacent to the cooling water inlet of the in-cylinder block flow path 32. The water pump 33 is driven by power transmitted from a crankshaft (not shown) of the engine 10.

  The downstream cooling water flow path 34 causes the cooling water that has flowed through the cylinder block flow path 32 to flow into the waste heat recovery heat exchange flow path 22. For this reason, the downstream side cooling water flow path 34 is connected at its upstream end to the cooling water outlet part of the in-cylinder block flow path 32 and at the downstream end thereof is the cooling water inlet of the heat exchange path 22 for waste heat recovery. Connected to the department.

  The bypass flow path 35 diverts the cooling water from the vehicle interior heating unit 23 and connects the upstream side cooling water flow path 30 and the connection cooling water flow path 31.

  The bypass valve 36 is provided in the bypass flow path 35 and selectively switches the flow path of the cooling water. The opening and closing of the bypass valve 36 is controlled in accordance with an instruction signal input from the electrically connected ECU 40. When the bypass valve 36 is closed, the cooling water flows into the vehicle interior heating unit 23 (see FIG. 5A), while when the bypass valve 36 is opened, the cooling water flows into the bypass passage 35 (see FIG. 5). 5 (b)).

  The radiator flow path 37 allows cooling water to flow into the radiator 39 that exchanges heat between the cooling water and the outside air, and connects the downstream side of the connection cooling water flow path 31 and the upstream side of the downstream cooling water flow path 34. To do. A known thermostat 50 is provided at a branch portion between the radiator flow path 37 and the downstream cooling water flow path 34. When the cooling water temperature exceeds 87 ° C., the thermostat 50 causes the cooling water to flow through the radiator flow path 37. That is, the cooling water circulates in the cooling water circuit constituted by the cylinder block inner passage 32 and the radiator passage 37 (see FIG. 5C).

The cooling water temperature sensor 38 detects the temperature of the cooling water heated by the heat exchange with the exhaust gas, and is provided in the upstream cooling water passage 30 adjacent to the cooling water outlet portion of the heat exchange passage 22 for waste heat recovery. Is provided. The coolant temperature T _CO detected by the coolant temperature sensor 38 is inputted to the electrically connected ECU 40.

  The ECU 40 includes a bypass valve control unit 43 and a switching valve control unit 42 as some functional elements.

Bypass valve control unit 43, depending on the coolant temperature T _CO detected by the coolant temperature sensor 38, controls the bypass valve 36. More specifically, the ECU 40 stores, as the heating / heating upper limit threshold T _LIM1 , a fluid temperature (for example, 50 ° C.) at which the air blown into the passenger compartment is heated by the heater core portion 23c and can be sufficiently heated. ing.

Bypass valve control unit 43, the cooling water temperature T _CO input from coolant temperature sensor 38 when the following heating heating upper threshold T _LIM1 inputs closing instruction signal to the bypass valve 36. That is, the cooling water heated in the waste heat recovery heat exchange flow path 22 flows into the vehicle interior heating unit 23 (see FIG. 5A).

On the other hand, when the cooling water temperature T _CO input from coolant temperature sensor 38 exceeds the heating heat upper threshold T _LIM1, bypass valve control unit 43 inputs a valve-opening instruction signal to the bypass valve 36. That is, the cooling water heated in the waste heat recovery heat exchange flow path 22 flows into the bypass flow path 35 and bypasses the vehicle interior heating unit 23 (see FIG. 5B).

Switching valve control unit 42, depending on the coolant temperature T _CO detected by the coolant temperature sensor 38, and controls the exhaust flow switching valve 21. More specifically, the ECU 40 stores a temperature (for example, 80 ° C.) that prevents boiling of the cooling water as the cooling water temperature upper limit threshold T _LIM3 . Switching valve control unit 42, the cooling water temperature T _CO input from coolant temperature sensor 38 when the cooling water temperature upper threshold T _{LIM 3} below, inputs an instruction signal for turning ON the exhaust flow switching valve 21. On the other hand, the cooling water temperature T _CO input from coolant temperature sensor 38 is more than the cooling water temperature upper threshold T _{LIM 3,} the switching valve control unit 42 inputs an instruction signal to the OFF exhaust flow switching valve 21.

  Next, based on FIG. 6, the control flow by the vehicle heating device 20B of the present embodiment will be described. This control starts simultaneously with the start of the engine 10 (ignition switch key switch ON).

  In S <b> 200, the water pump 33 is driven by the start of the engine 10, and an instruction signal for turning on the exhaust flow path switching valve 21 is input from the switching valve control unit 42. That is, the temperature of the cooling water is raised by heat exchange with the exhaust gas in the waste heat recovery heat exchange flow path 22, and the raised cooling water flows into the vehicle interior heating unit 23 via the upstream fluid flow path 24. Then, heating of the air blown into the passenger compartment is started.

Thereafter, in S210, the cooling water temperature T _CO input from coolant temperature sensor 38 whether the reached heating heating upper threshold T _LIM1 is determined. While the cooling water temperature T _CO is returned to S200 in the following cases: heating heating upper threshold T _LIM1, when the cooling water temperature T _CO exceeds the heating heat upper threshold T _LIM1 proceeds to S220.

In S220, in response to the fact that the cooling water temperature T _CO reaches the heating heat upper threshold T _LIM1, the valve opening instruction signal is inputted from the bypass valve control unit 43 to the bypass valve 36. That is, the cooling water bypasses the vehicle interior heating unit 23.

In S230, the cooling water temperature T _CO input from coolant temperature sensor 38 whether or not reached in the cooling water temperature upper threshold T _{LIM 3} is determined. If the cooling water temperature T _CO is below the cooling water temperature upper threshold T _{LIM 3} is returned to S220 to continue the warming up of the engine 10. On the other hand, the cooling water temperature T _CO may exceed the cooling water temperature upper threshold T _{LIM 3} an instruction signal to turn OFF the exhaust passage switching valve 21 from the switching valve control unit 42 in S240 is input.

  Further, in S250, in response to the cooling water temperature exceeding 87 ° C., the cooling water flow path is switched from the downstream cooling water flow path 34 to the radiator flow path 37 by the thermostat 50. That is, the flow path of the cooling water is switched to the cooling water circuit constituted by the in-cylinder block flow path 32 and the radiator flow path 37, and this control is returned.

  Next, the effect by the vehicle heating device 20B of this embodiment is demonstrated. In addition, description is abbreviate | omitted about what has the same effect as the heating apparatus 20A for vehicles of 1st embodiment.

  In the vehicle heating apparatus 20B of the present embodiment, after the engine 10 is started, the cooling water whose temperature has been raised by heat exchange with the exhaust gas in the waste heat recovery heat exchange flow path 22 passes through the vehicle interior heating unit 23 and the cylinder block. It flows into the flow path 32. When the temperature of the cooling water flowing into the heater core portion 23c reaches a predetermined temperature at which heating can be sufficiently performed, the cooling water bypasses the vehicle interior heating unit 23 and waste heat is exhausted until the warm-up of the engine 10 is completed. It flows into the cylinder block flow path 32 while being further heated in the recovery heat exchange flow path 22. That is, even after the temperature of the heater core 23c is raised to a temperature at which the heater core 23c can be sufficiently heated with the cooling water heated by the waste heat recovery, the heating of the cooling water by the waste heat recovery is continued and the warm-up of the engine 10 is promoted. Is done.

  Therefore, according to the vehicle heating device 20B of the present embodiment, the heater performance can be effectively improved while the warm-up performance of the engine 10 is improved.

  The present invention is not limited to the above-described embodiments, and can be appropriately modified and implemented without departing from the spirit of the present invention.

  For example, although the heat exchange exhaust passage 11a and the branch exhaust passage 11b have been described as being formed in the exhaust passage 11 on the exhaust downstream side of the silencer, they may be formed immediately downstream of the SCR 14, and the catalyst heater If provided, it may be formed on the exhaust upstream side of the SCR 14.

  Moreover, in 2nd embodiment, it is good also as a structure further equipped with the electric pump 26 in the upstream cooling water flow path 30. FIG. In this case, if the water pump 33 is an electromagnetic clutch type water pump and the driving thereof is stopped as necessary, the engine load during the warm-up operation can be effectively reduced.

  The engine 10 is not limited to a diesel engine, and may be a gasoline engine or the like.

DESCRIPTION OF SYMBOLS 10 Engine 11 Exhaust passage 11a Heat exchange exhaust passage 11b Branch exhaust passage 21 Exhaust flow path switching valve 22 Waste heat recovery heat exchange flow path (heat exchange flow path)
23 Car interior heating unit 23c Heater core part 24 Upstream fluid flow path (first fluid flow path)
25 Downstream fluid channel (second fluid channel)
26 Electric pump 40 ECU

Claims (3)

A heat exchange passage provided in an exhaust passage of the engine for exchanging heat between the exhaust flowing through the exhaust passage and a fluid made of the cooling water of the engine to be circulated;
A heater core that circulates the fluid heated in the heat exchange flow path and performs heat exchange between the fluid and the air blown into the vehicle interior;
A first fluid channel connecting the fluid outlet of the heat exchange channel and the fluid inlet of the heater core;
A fluid outlet portion of the heater core and a fluid inlet portion of the heat exchange passage , and at least a second fluid passage formed in a cylinder block of the engine ;
A pump provided in the first fluid flow path or the second fluid flow path to pump the fluid;
A bypass flow path for connecting the first fluid flow path and the second fluid flow path positioned upstream of the cylinder block to bypass the fluid flow path from the heater core;
A bypass valve that switches the fluid flow path to the heater core or the bypass flow path ,
The bypass valve switches the fluid flow path to the bypass flow path when the temperature of the fluid flowing into the heater core becomes higher than a second upper limit threshold value that can sufficiently heat air as a heat source for heating. A vehicle heating device. A branched exhaust passage formed by branching from an exhaust passage upstream of the heat exchange passage;
A flow path switching valve provided at a branch portion between the exhaust passage and the branch exhaust passage to switch an exhaust flow path,
The flow switching valve is provided with the heat exchange flow path as an exhaust flow path when the temperature of the fluid heated in the heat exchange flow path is equal to or lower than a first upper limit threshold value that prevents boiling of the fluid. 2. The vehicle according to claim 1, wherein the exhaust passage is switched to the branched exhaust passage when the temperature of the fluid heated in the heat exchange passage becomes higher than the first upper limit threshold while the exhaust passage is used. Heating device. The vehicle heating device according to claim 1 or 2 , wherein an exhaust gas purification catalyst for purifying exhaust gas is provided in the exhaust gas passage, and the heat exchange flow path is provided in an exhaust gas passage downstream of the exhaust gas purification catalyst.