JP2016074380A - Vehicle heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle heating apparatus capable of sufficiently using, for a heating operation, the quantity of heat obtained from an exhaust heat recovery unit while suppressing the reduction of engine warm-up operation efficiency.SOLUTION: This vehicle heating apparatus 100 comprises: an engine cooling water passage 1a; an exhaust heat recovery passage 1c that includes an exhaust heat recovery unit 13; an electric W/P 16b circulating cooling water in the exhaust heat recovery passage 1c; an electric W/P 16a circulating the cooling water in the engine cooling water passage 1a; a heater core 14; and a sub-heater core 15 smaller in heat radiation amount than the heater core 14. The vehicle heating apparatus 100 also comprises three-way valves 17a to 17c switching over between a circulation route A in which the sub-heater core 15 is connected to the exhaust heat recovery passage 1c without connecting the engine cooling water passage 1a thereto and a circulation route B in which the heater core 14 is connected to the exhaust heat recovery passage 1c without connecting the engine cooling passage 1a thereto.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle heating device.

  2. Description of the Related Art Conventionally, a vehicle heating apparatus including an exhaust heat recovery passage including an exhaust heat recovery device is known (see, for example, Patent Document 1).

  In Patent Document 1, as a first embodiment, a heat exchange flow path for exchanging heat between exhaust gas and cooling water in an exhaust passage of an engine, and heat exchange between cooling water and air in a passenger compartment are disclosed. There is disclosed a vehicle heating apparatus including a heater core to be performed, a cooling water flow path connecting the heat exchange flow path and the heater core, and a pump for circulating the cooling water. In the vehicle heating apparatus of the first embodiment, a fluid circuit separate from the engine coolant circuit is provided in order to suppress a decrease in engine warm-up operation efficiency. Moreover, in the vehicle heating device of the first embodiment, when the cooling water reaches a predetermined temperature or higher, the exhaust passage is switched, so that the exhaust air between the exhaust and the cooling water in the exhaust passage of the engine in the heat exchange passage is changed. It is configured to stop heat exchange.

  Further, in Patent Document 1, as a second embodiment, in addition to the configuration of the first embodiment, a cylinder block flow path for exchanging heat between the engine and the cooling water is connected to the cooling water flow path. In addition, a vehicle heating device is disclosed. In the vehicle heating device of the second embodiment, the cooling water is circulated through the heater core and the cylinder block flow path until the temperature of the cooling water rises to a predetermined temperature, thereby performing the heating operation, It is configured to perform warm-up operation.

JP 2013-249012 A

  However, in the vehicle heating apparatus according to the first embodiment of Patent Document 1, heat exchange between the exhaust gas and the cooling water is performed in the exhaust passage of the engine in the heat exchange flow path when the cooling water reaches a predetermined temperature or higher. Therefore, the heat exchange is not performed in the heater core after the heat exchange between the exhaust gas and the cooling water is stopped. For this reason, there exists a problem that the heat obtained from a heat exchange channel cannot fully be used for heating operation.

  Further, in the vehicle heating device of the second embodiment, it is considered that the cooling water is circulated through the heater core and the cylinder block passage even when the engine is not warmed up sufficiently. For this reason, in a state where engine warm-up operation is insufficient, the engine heat is transmitted to the cooling water in the heater core (deprived), resulting in a decrease in engine warm-up operation efficiency. It is believed that there is.

  The present invention has been made to solve the above-described problems, and one object of the present invention is obtained from an exhaust heat recovery device while suppressing a decrease in engine warm-up operation efficiency. An object of the present invention is to provide a vehicle heating apparatus that can sufficiently use heat for heating operation.

  In order to achieve the above object, a vehicle heating apparatus according to one aspect of the present invention is provided so as to be connectable to an engine cooling water passage for cooling an engine and the engine cooling water passage, and recovers exhaust heat of the engine. An exhaust heat recovery passage including an exhaust heat recovery device that transmits the coolant to the cooling water, a first water pump that causes the cooling water to flow through the exhaust heat recovery passage, and a second water pump that causes the cooling water to flow through the engine cooling water passage; The cooling water passage is connected to the main heater core that transmits the heat of the cooling water to the air, the auxiliary heater core that transmits the heat of the cooling water to the air, and the heat dissipation amount is smaller than that of the main heater core. A path switching unit that switches between a first circulation path that connects the auxiliary heater core without connecting to a second circulation path that connects the main heater core without connecting the engine coolant passage to the exhaust heat recovery path; Provided.

  In the vehicle air conditioning system according to one aspect of the present invention, as described above, the exhaust heat recovery passage includes the first circulation path that connects the auxiliary heater core without connecting the engine cooling water passage, and the exhaust heat recovery passage. A path switching unit that switches between the second circulation path that connects the main heater core without connecting the engine coolant passage is provided. As a result, when the amount of exhaust heat recovered by the exhaust heat recovery device is small, it is possible to efficiently use a small amount of heat for heating operation by switching to the first circulation path and dissipating heat with an auxiliary heater core with a small amount of heat dissipation. it can. In addition, when the amount of exhaust heat recovered by the exhaust heat recovery device is large, the heat obtained from the exhaust heat recovery device can be sufficiently used for heating operation by switching to the second circulation path and dissipating heat from the main heater core. it can. In addition, since neither the first circulation path nor the second circulation path is connected to the engine coolant passage, the main heater core and the auxiliary heater core are connected to the engine coolant passage in a state where the engine warm-up operation is insufficient. As a result, it is possible to suppress the heat of the engine from being transmitted (taken away) to the cooling water and released from the main heater core or the auxiliary heater core. Thereby, it can suppress that the engine warm-up operation efficiency falls. As a result, it is possible to sufficiently use the heat obtained from the exhaust heat recovery device for the heating operation while suppressing a decrease in the engine warm-up operation efficiency.

  In the vehicle heating device according to the above aspect, preferably, at the initial stage of engine warm-up operation, the vehicle is switched to the first circulation path, the cooling water is circulated to the first circulation path by the first water pump, and then the path is switched. It is configured to switch to the second circulation path by the section and to circulate the cooling water to the second circulation path by the first water pump. With this configuration, when it is desired to minimize the amount of heat transferred (sucked) from the engine to the cooling water, such as in the early stage of engine warm-up, both the main heater core and the auxiliary heater core are connected to the engine cooling water passage. By not doing so, it is possible to reliably suppress the heat of the engine from being transferred (taken away) to the cooling water. Thereby, it can suppress reliably that the engine warm-up operation efficiency falls. Further, at the initial stage of engine warm-up operation, the engine is switched to the first circulation path, and then switched to the second circulation path by the path switching unit. If comprised in this way, when the amount of exhaust heat recovery from an exhaust heat recovery device at the time of engine starting etc. is small, a small amount of heat is efficiently generated by the auxiliary heater core by switching to the first circulation path by the path switching unit. It can be used for heating operation. Further, after the switch to the first circulation path, when the amount of exhaust heat recovery from the exhaust heat recovery device becomes large due to the operation of the engine, the main heater core exhausts the heat by switching to the second circulation path by the path switching unit. The heat obtained from the recovery unit can be sufficiently used for the heating operation.

  In this case, preferably, at the initial stage of the warm-up operation of the engine, based on the fact that the exhaust heat recovery amount of the exhaust heat recovery device is equal to or greater than a predetermined exhaust heat recovery amount, the path switching unit causes the second circulation path to be It is configured to switch to a circulation path. If comprised in this way, it can suppress that a circulation path is switched in a state with a small waste heat recovery amount by switching a circulation path based on a waste heat recovery amount. Thereby, the heat obtained from the exhaust heat recovery device can be effectively used for the heating operation.

  In the configuration in which the engine is switched to the first circulation path in the initial warm-up operation of the engine and then switched to the second circulation path, preferably, the path switching unit further includes a main heater core and an engine coolant passage connected to the exhaust heat recovery passage. It is configured to be switchable to the third circulation path, and is configured to switch to the third circulation path in the middle of the warm-up operation of the engine and to circulate the cooling water to the third circulation path by the second water pump. Yes. With this configuration, in the middle of the warm-up operation of the engine in which the engine has been warmed up to some extent, the heat recovered by the exhaust heat recovery device is connected by connecting the main heater core and the engine coolant passage to the exhaust heat recovery passage. And the heat from the engine can be used for the heating operation by the main heater core and the engine warm-up operation. Thereby, when the exhaust heat recovery amount is large, a part of the exhaust heat recovery amount can be used for the engine warm-up operation, so that the engine warm-up operation efficiency can be improved. In addition, when the heating requirement is large and it is necessary to release a larger amount of heat than the exhaust heat recovery amount from the main heater core, the heating requirement is surely satisfied by using a part of the engine heat for heat radiation from the main heater core. Can do. As a result, it is possible to achieve both improvement in the engine warm-up operation efficiency and improvement in the heating performance of the vehicle heating device. In the middle of the warm-up operation of the engine, the temperature of the engine has risen to some extent. Therefore, even if a part of the heat of the engine is used for the heating operation, it is not considered a problem.

  In the configuration in which the engine is switched to the third circulation path in the middle of the warm-up operation of the engine, the cooling water is preferably disposed between the radiator connected in parallel to the engine cooling water passage and the engine cooling water passage and the radiator. A valve member that opens when the temperature rises to a value equal to or higher than the value temperature, and the cooling water flowing through the third circulation path rises to a temperature equal to or higher than a threshold temperature when the warm-up operation of the engine is completed. Thus, the valve member is opened, a fourth circulation path in which a radiator is connected to the third circulation path is formed, and cooling water is circulated to the fourth circulation path by the second water pump. Yes. With this configuration, the heat of the cooling water can be released not only in the main heater core but also in the radiator at the completion of the warm-up operation of the engine that has been sufficiently warmed up. Cooling can be ensured.

  In the configuration in which the engine is switched to the third circulation path in the middle of the warm-up operation of the engine, preferably, in the middle period of the warm-up operation of the engine, the cooling water is circulated to the first circulation path by the first water pump, Is provided independently, and after controlling to circulate the cooling water by the second water pump to the fifth circulation path connecting the engine cooling water passage and the main heater core, the second water pump is switched to the third circulation path. The cooling water is circulated through the third circulation path by the pump. If comprised in this way, by providing the 5th circulation path which connected the engine cooling water passage and the main heater core separately from the 1st circulation path which makes heat dissipation with the auxiliary heater core with small heat dissipation, and the 1st circulation path, While using a small amount of heat from the exhaust heat recovery device for the heating operation by the auxiliary heater core, the heat of the engine can be used for the heating operation by the main heater core. Thereby, since the amount of heat required for the heating operation of the main heater core can be reduced by the amount of heating operation of the auxiliary heater core, it is possible to suppress the heat of the engine from being significantly transmitted (taken away) to the cooling water. . As a result, it is possible to suppress the engine warm-up operation efficiency from greatly decreasing. In addition, after the first circulation path and the fifth circulation path are provided, the engine cooling water passage and the exhaust heat recovery passage are then switched to the third circulation route connected to the main heater core, thereby recovering the exhaust heat. After the amount has increased to some extent, switching to the third circulation path makes it possible to achieve both improvement in engine warm-up operation efficiency and improvement in the heating performance of the vehicle heating device.

  In addition, in this application, the following structures are also considered in the heating apparatus for vehicles by the said one situation.

(Additional item 1)
That is, in the vehicle heating apparatus according to the above aspect, the path switching unit is disposed between the exhaust heat recovery passage, the main heater core, and the auxiliary heater core, and switches between the first circulation path and the second circulation path. It includes a first switching valve, and a second switching valve that is disposed between the exhaust heat recovery passage and the engine coolant passage and switches between connection and disconnection of the exhaust heat recovery passage and the engine coolant passage.

(Appendix 2)
In the vehicle heating device according to the first aspect, the water capacity of the cooling water in the first circulation path is smaller than the water capacity of the cooling water in the second circulation path.

  According to the present invention, as described above, the amount of heat obtained from the exhaust heat recovery device can be sufficiently used for the heating operation while suppressing a decrease in the warm-up operation efficiency of the engine.

In the vehicle by one Embodiment of this invention, it is the schematic which showed the positional relationship of the main components of the heating apparatus for vehicles. It is the figure which showed roughly the heating apparatus for vehicles by one Embodiment of this invention. It is the figure which showed roughly the circulation path | route A of the heating apparatus for vehicles by one Embodiment of this invention. It is the figure which showed roughly the circulation path | route B of the heating apparatus for vehicles by one Embodiment of this invention. It is the figure which showed roughly the state in which the circulation paths C and D of the heating apparatus for vehicles by one Embodiment of this invention are provided together. It is the figure which showed roughly the circulation path | route E of the heating apparatus for vehicles by one Embodiment of this invention. It is the figure which showed roughly the circulation path F of the heating apparatus for vehicles by one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1 and FIG. 2, the structure of the heating apparatus 100 for vehicles by one Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the vehicle heating apparatus 100 according to the first embodiment is configured to be applied to air conditioning (heating) of a passenger compartment 95 of a vehicle 90 such as a passenger car, a bus, and a truck provided with an engine 91. ing. The vehicle heating device 100 is configured to be driven and controlled by an ECU (not shown). Moreover, the layout of piping and apparatus arrangement | positioning is comprised so that the heating apparatus 100 for vehicles can be mounted in the vehicle 90. FIG.

  The vehicle heating device 100 is configured such that cooling water (coolant) for cooling the engine 91 can be circulated. As shown in FIG. 2, the vehicle heating apparatus 100 includes a radiator 11, a thermostat 12, an exhaust heat recovery unit 13, a heater core 14, a sub heater core 15, and a pair of electric water pumps (electric W / P) 16a and 16b.

  The radiator 11 includes a radiator core, and has a role of cooling the cooling water by outside air mainly taken from the front of the vehicle 90 (see FIG. 1). Further, the thermostat 12 is closed when the temperature of the cooling water is lower than the valve opening temperature (for example, about 90 ° C.), and is opened when the temperature of the cooling water is equal to or higher than the valve opening temperature. It is configured. The exhaust heat recovery unit 13 is, for example, a plate heat exchanger, a high-temperature (about 300 ° C. to about 400 ° C.) exhaust gas flowing through an exhaust gas pipe 92 connected to the engine 91 of the vehicle 90, and exhaust heat recovery. The cooling water flowing through the vessel 13 is configured to exchange heat. Thereby, the exhaust heat recovery device 13 is configured to recover the exhaust heat of the engine 91 and transmit it to the cooling water. The exhaust heat recovery device 13 is not limited to a plate heat exchanger, and may be a tube heat exchanger or the like.

  Each of the heater core 14 and the sub-heater core 15 has a function of transmitting heat of the cooling water to the circulating air, and is used when heating the interior of the passenger compartment 95 (see FIG. 1). Here, the sub-heater core 15 is configured to be able to release a heat amount of about 2 kW or less to the air. The heat dissipation amount of the sub-heater core 15 is smaller than the heat dissipation amount of the heater core 14 because the heat dissipation surface is smaller than that of the heater core 14.

  Further, as shown in FIG. 1, the sub heater core 15 is disposed in a position closer to the exhaust heat recovery device 13 than the heater core 14 in the vehicle 90. Specifically, the exhaust heat recovery device 13 is disposed on the front side of the seat 95 a disposed in the passenger compartment 95 and below the vehicle 90 below. The heater core 14 is disposed in front of the seat 95a, and is disposed in an upper portion of the vehicle 90 that is spaced upward from the exhaust heat recovery device 13. On the other hand, the sub-heater core 15 is disposed immediately before the seat 95a and immediately above the exhaust heat recovery unit 13, and as a result, is disposed nearer the exhaust heat recovery unit 13 than the heater core 14.

  As shown in FIG. 2, the electric W / Ps 16 a and 16 b are electric water pumps, and are configured to be driven by stored power of a battery (not shown) regardless of the operating state of the engine 91. Thus, the engine 91 is configured such that the electric W / Ps 16a and 16b can be driven by the generated power of an alternator (not shown) when the engine 91 is in operation.

  Further, in the vehicle heating apparatus 100, each component is connected by the cooling water passage 1. The cooling water passage 1 includes an engine cooling water passage 1a, a radiator passage 1b, an exhaust heat recovery passage 1c, an exhaust heat recovery device bypass passage 1d, a heater passage 1e, a sub heater passage 1f, an engine bypass passage 1g, And a thermostat passage 1h.

  An engine 91 and an electric W / P 16a are arranged in the engine coolant passage 1a, and the engine 91 is cooled in the passage. Specifically, when the cooling water flows through an engine cooling water passage 1a in a water jacket (not shown) provided in the engine 91, heat generated from the engine 91 is transmitted to the cooling water, and the engine 91 is cooled. The

  A radiator 11 connected in parallel to the engine coolant passage 1a is disposed in the radiator passage 1b. An exhaust heat recovery device 13 is disposed in the exhaust heat recovery passage 1c. A heater core 14 is disposed in the heater passage 1e. A sub-heater core 15 is disposed in the sub-heater passage 1f. An electric W / P 16b is disposed in the engine bypass passage 1g.

  In addition, three-way valves 17a, 17b, and 17c that connect two of the three passages are disposed at a predetermined connection portion of the cooling water passage 1. Specifically, the engine cooling water passage 1a on the downstream side of the engine 91, the exhaust heat recovery passage 1c on the upstream side of the exhaust heat recovery device 13, and the exhaust heat recovery device bypass passage 1d are connected to the three-way valve 17a. Has been. That is, the three-way valve 17a is disposed between the engine coolant passage 1a and the exhaust heat recovery passage 1c, and has a function of switching connection and disconnection between the engine coolant passage 1a and the exhaust heat recovery passage 1c. ing.

  The three-way valve 17b is connected to an exhaust heat recovery passage 1c on the downstream side of the exhaust heat recovery device 13, a heater passage 1e on the upstream side of the heater core 14, and a sub heater passage 1f on the upstream side of the sub heater core 15. That is, the three-way valve 17b is disposed between the heater core 14 and the sub-heater core 15, and has a function of switching between a circulation path A and a circulation path B described later.

  A heater passage 1e on the downstream side of the heater core 14, an engine bypass passage 1g on the upstream side of the electric W / P 16b, and a thermostat passage 1h are connected to the three-way valve 17c.

  Further, a temperature sensor 18a for detecting the temperature of the cooling water flowing in the engine cooling water passage 1a is disposed in the engine cooling water passage 1a on the downstream side of the engine 91. This temperature sensor 18a is used to determine whether the engine 91 has not been warmed up substantially (initial stage of engine warmup), or has been performed to some extent (mid-time or when the engine is warmed up). Is provided. Specifically, when the temperature of the cooling water detected by the temperature sensor 18a is less than about 60 ° C., it is determined that the engine is warming up, and the temperature of the cooling water detected by the temperature sensor 18a is about When the temperature is 60 ° C. or higher, it is determined that the engine is warming up or being completed.

  In addition, a temperature sensor 18b for detecting the temperature of the cooling water flowing in the exhaust heat recovery passage 1c is disposed in the exhaust heat recovery passage 1c on the downstream side of the exhaust heat recovery device 13. The temperature sensor 18b is configured to detect whether the temperature of the cooling water flowing through the exhaust heat recovery passage 1c is equal to or higher than the boiling point of the cooling water. It is possible to calculate the amount of exhaust heat recovered that is recovered in the cooling water in the exhaust heat recovery unit 13 based on the detection results of the temperature sensors 18a and 18b and the flow rate of the cooling water. It is also possible to calculate the exhaust heat recovery amount from the intake air amount to the exhaust gas pipe 92 and the exhaust temperature before the catalyst.

  The upstream side of the thermostat 12 is connected to the thermostat passage 1h, and the downstream side is connected to the engine coolant passage 1a on the upstream side of the electric W / P 16a and the radiator passage 1b on the upstream side of the radiator 11. It is connected. The radiator passage 1 b is connected to the engine coolant passage 1 a on the downstream side of the engine 91 on the downstream side of the radiator 11.

  The exhaust heat recovery device bypass passage 1d is connected to the three-way valve 17a, and is connected to the heater passage 1e upstream of the heater core 14 and downstream of the three-way valve 17b. The downstream side of the sub-heater passage 1f is connected to the engine bypass passage 1g upstream of the electric W / P 16b and downstream of the three-way valve 17c. The downstream side of the engine bypass passage 1g is connected to the exhaust heat recovery passage 1c upstream of the exhaust heat recovery unit 13 and downstream of the three-way valve 17a.

  Here, in the present embodiment, the vehicle heating apparatus 100 is configured so that the passage of the three-way valves 17a to 17c is based on the warm-up operation state of the engine 91 and the exhaust heat recovery amount in the exhaust heat recovery unit 13 during the heating operation. By switching between the connection state and the open / close state of the thermostat 12, a plurality of circulation paths (circulation paths A to F) are switched. The three-way valves 17a to 17c are examples of the “path switching unit” of the present invention, and the thermostat 12 is an example of the “valve member” of the present invention.

  Next, with reference to FIG. 1 and FIGS. 3-7, the specific switching of the circulation path by the driving | operation of the engine 91 in this embodiment is demonstrated.

  The temperature of the cooling water detected by the temperature sensor 18a is less than about 60 ° C., and the exhaust heat recovery in the exhaust heat recovery unit 13 is performed at the initial stage of the engine warm-up operation where the warm-up operation of the engine 91 is not substantially performed. When the amount is less than the maximum heat dissipation amount (about 2 kW) of the sub-heater core 15 (the exhaust heat recovery amount is small), the circulation path of the vehicle heating device 100 is switched to the circulation path A shown in FIG. It is configured. In addition, as a case where the engine warm-up operation is in the initial stage and the exhaust heat recovery amount is small, the engine is immediately after starting.

  The circulation path A is constituted by an exhaust heat recovery passage 1c, a sub-heater passage 1f, and an engine bypass passage 1g as shown by a thick line in FIG. That is, in the circulation path A, the engine coolant passage 1a is not connected to the exhaust heat recovery passage 1c, and the sub heater passage 1f in which the sub heater core 15 is disposed is connected.

  In the circulation path A, the engine cooling water passage 1a on the downstream side of the engine 91 and the exhaust heat recovery device bypass passage 1d are connected by the three-way valve 17a. Further, the three-way valve 17 b connects the exhaust heat recovery passage 1 c on the downstream side of the exhaust heat recovery device 13 and the sub heater passage 1 f on the upstream side of the sub heater core 15. Further, the three-way valve 17c connects the heater passage 1e on the downstream side of the heater core 14 and the engine bypass passage 1g on the upstream side of the electric W / P 16b. Further, in the circulation path A, the thermostat 12 is in a closed state. In the circulation path A, the cooling water is circulated by driving the electric W / P 16b of the engine bypass path 1g. The circulation path A is an example of the “first circulation path” in the present invention, and the electric W / P 16b is an example of the “first water pump” in the present invention.

  Here, in the circulation path A, the cooling water in the engine cooling water passage 1 a where the engine 91 is located is not circulated, so that the heat of the engine 91 is suppressed from being transmitted to the sub heater core 15. As a result, it is possible to perform the heating operation by circulating the cooling water through the exhaust heat recovery unit 13 and the sub heater core 15 without circulating the cooling water through the engine 91 as a heat source.

  While the warming-up operation of the engine 91 is still insufficient (the engine warm-up operation initial stage), the exhaust heat recovery amount in the exhaust heat recovery device 13 is maximized by the sub-heater core 15 due to the engine 91 running at high speed or high load operation. When the heat amount (about 2 kW) or more (exhaust heat recovery amount is large), the circulation path of the vehicle heating device 100 is configured to be switched from the circulation path A to the circulation path B shown in FIG. .

  The circulation path B is composed of an exhaust heat recovery passage 1c, a heater passage 1e, and an engine bypass passage 1g as shown by a thick line in FIG. That is, in the circulation path B, similarly to the circulation path A, the engine coolant passage 1a is not connected to the exhaust heat recovery passage 1c, and the heater core 14 is different from the circulation path A in which the sub heater passage 1f is connected. Is connected to the heater passage 1e.

  In the circulation path B, unlike the circulation path A, the three-way valve 17 b connects the exhaust heat recovery passage 1 c on the downstream side of the exhaust heat recovery device 13 and the heater passage 1 e on the upstream side of the heater core 14. In other words, the circulation path A is switched to the circulation path B by the three-way valve 17b. Further, in the circulation path B, as in the circulation path A, the thermostat 12 is in a closed state, and the cooling water is circulated by driving the electric W / P 16b of the engine bypass path 1g. The circulation path B is an example of the “second circulation path” in the present invention.

  Here, in the circulation path B, similarly to the circulation path A, the cooling water in the engine cooling water passage 1a where the engine 91 is located is not circulated, so that the heat of the engine 91 is suppressed from being transmitted to the heater core 14. As a result, it is possible to perform the heating operation by circulating the cooling water through the exhaust heat recovery device 13 and the heater core 14 without circulating the cooling water through the engine 91 as a heat source.

Further, in the present embodiment, as shown in FIG. 1, the circulation path A (broken line) through which the cooling water flows through the sub-heater core 15 disposed nearer the exhaust heat recovery unit 13 than the heater core 14 is provided by the sub-heater core 15. In addition, the flow path length through which the cooling water flows is shorter than the circulation path B (one-dot chain line) through which the cooling water flows through the heater core 14 disposed at a position separated from the exhaust heat recovery unit 13. As a result, the water capacity of the cooling water flowing through the circulation path A is about 1 × 10 ⁻³ m ³ , while the water capacity of the cooling water flowing through the circulation path B is 3 × 10 ⁻³ to 4 × 10. becomes about ^-3 m ^3, the result, the water capacity of the cooling water circulation path a is smaller than the water volume of the cooling water circulation path B. Therefore, the amount of heat required to warm the cooling water flowing through the circulation path A is less than the amount of heat required to warm the cooling water flowing through the circulation path B.

  Thereby, when switching to the circulation path A, even if the exhaust heat recovery amount in the exhaust heat recovery device 13 is small, it is possible to warm the cooling water flowing through the circulation path A with a small amount of heat. A small amount of heat can be efficiently used for the heating operation by the sub-heater core 15. On the other hand, when the exhaust heat recovery amount greater than the amount of heat that can be radiated by the sub-heater core 15 (maximum heat dissipation amount, about 2 kW) is recovered from the exhaust heat recovery device 13, the water capacity of the cooling water in the circulation path A is small. The temperature of the cooling water in the circulation path A easily rises and the cooling water may boil. Therefore, when the exhaust heat recovery amount equal to or greater than the maximum heat dissipation amount is recovered from the exhaust heat recovery device 13, the cooling water is supplied from the circulation path A to the heater core 14 having a large cooling water capacity and a large heat dissipation amount. By switching to the circulation path B that circulates, it is possible to suppress the boiling of the cooling water, and it is possible to sufficiently use the amount of heat obtained from the exhaust heat recovery device 13 for the heating operation.

  An engine in which the temperature of the cooling water detected by the temperature sensor 18a is about 60 ° C. or higher and lower than the valve opening temperature of the thermostat 12, and the engine 91 is warmed up to some extent (the temperature of the engine 91 has increased). In the middle of the warm-up operation and when the exhaust heat recovery amount is small, as shown in FIG. 5, the circulation path of the vehicle heating device 100 is switched to a state in which both of the circulation paths C and D are provided. It is configured. In general, the engine is switched to a state in which both of the circulation paths C and D are provided at the initial stage of the engine warm-up operation and after the circulation path A with a small exhaust heat recovery amount.

  The circulation path C is the same as the circulation path A shown in FIG. 3, as shown by a thick line in FIG. Further, as shown by a thick line in FIG. 5, the circulation path D includes an engine cooling water passage 1a, an exhaust heat recovery device bypass passage 1d, a heater passage 1e, and a thermostat passage 1h. That is, in the circulation path D, the engine coolant passage 1a and the heater passage 1e in which the heater core 14 is disposed are connected. The circulation paths C and D are examples of the “first circulation path” and the “fifth circulation path” of the present invention, respectively.

  In the state where both the circulation paths C and D are provided, unlike the case of only the circulation path A, the heater passage 1e on the downstream side of the heater core 14 and the thermostat passage 1h are connected by the three-way valve 17c. That is, the three-way valve 17c is configured to switch the circulation path A to a state in which the circulation paths C and D are both provided. Further, in a state where the circulation paths C and D are both provided, the thermostat 12 is in a closed state.

  Further, as shown in FIG. 5, the circulation path D is not connected to the circulation path C and is provided independently of the circulation path C by the three-way valves 17 a to 17 c. That is, the circulation path C in which the exhaust heat recovery device 13 is arranged is configured such that the cooling water is circulated independently with respect to the circulation path D in which the engine 91 and the thermostat 12 are arranged. In the circulation path C, the cooling water is circulated by driving the electric W / P 16b of the engine bypass passage 1g, and in the circulation path D, the electric W / P 16a of the engine cooling water path 1a is driven. Thus, the cooling water is circulated.

  Here, since the thermostat 12 is not disposed in the circulation paths A to C, the temperature of the cooling water flowing through the circulation paths A to C can be made higher than the valve opening temperature of the thermostat 12. Thereby, since the temperature difference between the cooling water in the temperature range higher than the valve opening temperature of the thermostat 12 and the air in the passenger compartment 95 can be increased, the heating efficiency by the sub heater core 15 or the heater core 14 is improved. Is possible.

  In the middle of the engine warm-up operation and when the exhaust heat recovery amount is large, the circulation path of the vehicle heating device 100 is configured to be switched to the circulation path E as shown in FIG. In general, the circulation paths C and D at the initial stage of the engine warm-up operation and after the circulation path B with a large exhaust heat recovery amount or at the middle stage of the engine warm-up operation and with a small exhaust heat recovery amount After being provided together, the circuit is switched to the circulation path E. The circulation path E includes an engine coolant passage 1a, an exhaust heat recovery passage 1c, a heater passage 1e, and a thermostat passage 1h. That is, in the circulation path E, the engine 91 and the exhaust heat recovery device 13 are connected to the heater core 14. The circulation path E is an example of the “third circulation path” in the present invention.

  In the circulation path E, the engine cooling water passage 1a on the downstream side of the engine 91 and the exhaust heat recovery passage 1c on the upstream side of the exhaust heat recovery device 13 are connected by the three-way valve 17a. Further, the exhaust heat recovery passage 1 c on the downstream side of the exhaust heat recovery device 13 and the heater passage 1 e on the upstream side of the heater core 14 are connected by the three-way valve 17 b. Further, the heater passage 1e on the downstream side of the heater core 14 and the thermostat passage 1h are connected by the three-way valve 17c. Further, in the circulation path E, the thermostat 12 is in a closed state. Further, in the circulation path E, the coolant is circulated by driving the electric W / P 16a of the engine coolant passage 1a.

  Here, in the circulation path E, the heat of the engine 91 and the heat of the exhaust heat recovery device 13 are transmitted to the heater core 14. In addition, when the exhaust heat recovery amount in the exhaust heat recovery unit 13 is large, a part of the exhaust heat recovery amount can be used for the warm-up operation of the engine 91. Further, when the heating requirement is large and it is necessary to release a heat amount larger than the exhaust heat recovery amount from the heater core 14, a part of the heat of the engine 91 can be used for heat radiation from the heater core 14.

  Further, when the operation of the engine 91 is stopped, by switching to the circulation path E shown in FIG. 6, it is possible to perform heating by the heater core 14 using the heat remaining in the engine 91. At this time, in the circulation path E, the cooling water is circulated by the electric W / P 16a. Therefore, even if the operation of the engine 91 is stopped, the cooling water is circulated in the circulation path E. It is possible.

  When the temperature of the cooling water flowing through the thermostat 12 is equal to or higher than the valve opening temperature of the thermostat 12 and the engine 91 is sufficiently warmed up, as shown in FIG. The circulation path of the apparatus 100 is configured to be switched to the circulation path F when the thermostat 12 opens from the state of the circulation path E. That is, the circulation path F is formed by connecting the radiator 11 to the circulation path E. Further, in the circulation path F, the coolant is circulated by driving the electric W / P 16a of the engine coolant passage 1a. The circulation path F is an example of the “fourth circulation path” in the present invention, and the valve opening temperature of the thermostat 12 is an example of the “threshold temperature” in the present invention.

  Here, in the circulation path F, the heat of the engine 91 and the heat of the exhaust heat recovery device 13 are transmitted not only to the heater core 14 but also to the radiator 11, whereby the heat of the cooling water in the circulation path F is changed to the radiator 11. Is efficiently released from

  Thus, the connection state of the passages of the three-way valves 17a to 17c and the open / close state of the thermostat 12 are appropriately switched based on the warm-up operation state of the engine 91 and the exhaust heat recovery amount in the exhaust heat recovery unit 13. Thus, by switching a plurality of circulation paths (circulation paths A to F), it is possible to improve the heating performance of the vehicle heating device 100 while suppressing a decrease in the warm-up operation efficiency of the engine 91. .

  In the present embodiment, the following effects can be obtained.

  In the present embodiment, as described above, the three-way valve 17b causes the exhaust heat recovery passage 1c to be connected to the circulation path A that connects the sub heater core 15 without connecting the engine cooling water passage 1a and the exhaust heat recovery passage 1c. The circulation path B to which the heater core 14 is connected is switched without connecting the engine coolant passage 1a. Thereby, when the exhaust heat recovery amount by the exhaust heat recovery device 13 is small, the heat is efficiently used for the heating operation by switching to the circulation path A and dissipating heat with the sub-heater core 15 having a small heat dissipation amount. it can. When the amount of exhaust heat recovered by the exhaust heat recovery unit 13 is large, the amount of heat obtained from the exhaust heat recovery unit 13 can be sufficiently used for the heating operation by switching to the circulation path B and dissipating heat by the heater core 14. it can. Since neither the circulation path A nor the circulation path B is connected to the engine coolant passage 1a, the heater core 14 or the Due to the connection of the sub-heater core 15, it is possible to suppress the heat of the engine 91 from being transmitted (taken away) to the cooling water and released from the heater core 14 or the sub-heater core 15. Thereby, it can suppress that the warming-up operation efficiency of the engine 91 falls. As a result, it is possible to sufficiently use the heat obtained from the exhaust heat recovery device 13 for the heating operation while suppressing a decrease in the warm-up operation efficiency of the engine 91.

  Further, in the present embodiment, in the initial warm-up operation of the engine 91, switching to the circulation path A is performed, the cooling water is circulated through the circulation path A by the electric W / P 16b, and then the circulation path B is switched by the three-way valve 17b. Then, the cooling water is circulated through the circulation path B by the electric W / P 16b. As a result, when it is desired to reduce the amount of heat transferred (sucked) from the engine 91 to the cooling water as much as possible at the beginning of the engine warm-up operation, neither the heater core 14 nor the sub-heater core 15 is connected to the engine cooling water passage 1a. As a result, the heat of the engine 91 can be reliably suppressed (taken away) to the cooling water, so that the warm-up operation efficiency of the engine 91 can be reliably suppressed from decreasing.

  In the present embodiment, the engine 91 is switched to the circulation path A at the initial stage of the warm-up operation, and then switched to the circulation path B by the three-way valve 17b based on the increase in the exhaust heat recovery amount. As a result, when the amount of exhaust heat recovered from the exhaust heat recovery device 13 is small, such as when the engine 91 is started, the sub heater core 15 efficiently reduces the amount of heat by switching to the circulation path A by the three-way valve 17b. It can be used for heating operation. Further, after switching to the circulation path A, when the exhaust heat recovery amount from the exhaust heat recovery device 13 becomes large due to the operation of the engine 91, the heat is exhausted by the heater core 14 by switching to the circulation path B by the three-way valve 17b. The amount of heat obtained from the recovery unit 13 can be sufficiently used for the heating operation.

  In the present embodiment, the three-way valve 17b controls the exhaust heat recovery amount of the exhaust heat recovery device 13 to be equal to or greater than a predetermined exhaust heat recovery amount (about 2 kW) in the initial warm-up operation of the engine 91. Switch from circulation path A to circulation path B. Thereby, by switching the circulation path based on the exhaust heat recovery amount, switching of the circulation path in a state where the exhaust heat recovery amount is small can be suppressed. As a result, the heat obtained from the exhaust heat recovery device 13 can be effectively used for the heating operation.

  In the present embodiment, the three-way valves 17a to 17c are switched to the circulation path E in which the engine 91 and the exhaust heat recovery device 13 are connected to the heater core 14 in the middle of the warm-up operation of the engine 91. Cooling water is circulated through the circulation path E by P16a. Thereby, in the middle of the warm-up operation of the engine 91 in which the engine 91 has been warmed up to some extent, the heater core 14 and the engine coolant passage 1a are connected to the exhaust heat recovery passage 1c, and the exhaust heat recovery device 13 collects the heat. Heat and heat from the engine 91 can be used for heating operation by the heater core 14 and warm-up operation of the engine 91. As a result, when the exhaust heat recovery amount is large, a part of the exhaust heat recovery amount can be used for the warm-up operation of the engine 91, so that the warm-up operation efficiency of the engine 91 can be improved. Further, when the heating requirement is large and it is necessary to release a larger amount of heat than the exhaust heat recovery amount from the heater core 14, the heating requirement is surely satisfied by using a part of the heat of the engine 91 for heat radiation from the heater core 14. be able to. As a result, it is possible to improve both the warm-up operation efficiency of the engine 91 and the heating performance of the vehicle heating device 100.

  In the present embodiment, when the warm-up operation of the engine 91 is completed, the cooling water flowing in the circulation path E rises to a temperature equal to or higher than the threshold temperature (the valve opening temperature of the thermostat 12), so that the thermostat 12 The valve is opened to form a circulation path F in which the radiator 11 is connected to the circulation path E, and the cooling water is circulated through the circulation path F by the electric W / P 16a. Thereby, when the engine 91 is sufficiently warmed up, the heat of the cooling water can be released not only in the heater core 14 but also in the radiator 11 when the engine 91 is warmed up. Cooling can be ensured.

  In the present embodiment, in the middle of warm-up operation of the engine 91, the cooling water is circulated by the electric W / P 16b through the same circulation path C as the circulation path A, and provided independently of the circulation path C. After controlling the circulation of the cooling water by the electric W / P 16 a to the circulation path D connecting the engine cooling water passage 1 a and the heater core 14, the circulation in which the engine 91 and the exhaust heat recovery device 13 are connected to the heater core 14. Switching to the route E, the cooling water is circulated through the circulation route E by the electric W / P 16a. Thus, when the amount of exhaust heat recovered from the exhaust heat recovery unit 13 is small, the engine coolant passage 1a and the heater core 14 are separated from the circulation path C for radiating heat with the sub-heater core 15 having a small heat dissipation amount, and the circulation path C. By providing the circulation path D to which the heat exchanger 13 is connected, the heat of the engine 91 can be used for the heating operation by the heater core 14 while using a small amount of heat from the exhaust heat recovery device 13 for the heating operation by the sub-heater core 15. As a result, since the amount of heat required for the heating operation of the heater core 14 can be reduced by the amount of heating operation of the sub-heater core 15, it is possible to suppress the heat of the engine 91 from being significantly transmitted (taken away) to the cooling water. Can do. Therefore, it can suppress that the warming-up operation efficiency of the engine 91 falls significantly. Further, after the circulation path C and the circulation path D are provided, the engine coolant passage 1a and the exhaust heat recovery path 1c are then switched to the circulation path E connected to the heater core 14, whereby the amount of exhaust heat recovery is increased. Can be switched to the circulation path E after a certain degree of increase, and both improvement in the warm-up operation efficiency of the engine 91 and improvement in the heating performance of the vehicle heating device 100 can be achieved.

  In the present embodiment, a three-way valve 17a having a function of switching connection and disconnection between the engine coolant passage 1a and the exhaust heat recovery passage 1c is disposed between the engine coolant passage 1a and the exhaust heat recovery passage 1c. A three-way valve 17b having a function of switching between the circulation path A and the circulation path B is disposed between the heater core 14 and the sub heater core 15. Thus, the circulation path can be easily switched by switching the three-way valves 17a and 17b.

  In the present embodiment, the water capacity of the cooling water in the circulation path A is made smaller than the water capacity of the cooling water in the circulation path B. Thereby, when it is switched to the circulation path A, the cooling water flowing through the circulation path A can be warmed with a small amount of heat, so that the sub-heater core 15 can efficiently use a small amount of heat for the heating operation. . In addition, when the cooling water has a large capacity and the heat dissipation amount is switched to the circulation path B through which the cooling water flows, the cooling water can be prevented from boiling, The amount of heat obtained from the exhaust heat recovery device 13 can be sufficiently used for the heating operation.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above embodiment, based on the fact that the exhaust heat recovery amount of the exhaust heat recovery unit 13 is equal to or greater than a predetermined exhaust heat recovery amount (about 2 kW) in the initial stage of engine warm-up operation, the circulation path is caused by the three-way valve 17b. The three-way valves 17a to 17c are switched from A to the circulation path B based on the fact that the exhaust heat recovery amount of the exhaust heat recovery unit 13 is equal to or greater than a predetermined exhaust heat recovery amount (about 2 kW) in the middle of the engine warm-up operation. However, the present invention is not limited to this example. In the present invention, switching of the circulation path by the three-way valve may be performed based on a parameter other than the exhaust heat recovery amount of the exhaust heat recovery device. For example, the circulation path may be switched by a three-way valve based on the magnitude of the heating request or the temperature detected by the temperature sensor.

  Moreover, in the said embodiment, although the example using the electrically driven water pump 16a and 16b was shown, this invention is not limited to this. In the present invention, a water pump driven by the driving force of the engine may be used.

  In the above embodiment, an example in which the temperature sensor 18a is arranged on the engine coolant passage 1a separately from the engine 91 is shown, but the present invention is not limited to this. In the present invention, a temperature sensor may be provided integrally with the engine.

1a Engine cooling water passage 1c Waste heat recovery passage 11 Radiator 12 Thermostat (valve member)
13 Waste heat recovery unit 14 Heater core (main heater core)
15 Sub heater core (auxiliary heater core)
16a Electric W / P (second water pump)
16b Electric W / P (1st water pump)
17a, 17b, 17c Three-way valve (path switching unit)
91 Engine 100 Vehicle heating device A, C Circulation path (first circulation path)
B Circulation route (second circulation route)
D Circulation route (5th circulation route)
E Circulation route (third circulation route)
F Circulation route (4th circulation route)

Claims (6)

An engine coolant passage for cooling the engine;
An exhaust heat recovery passage provided so as to be connectable to the engine cooling water passage, and including an exhaust heat recovery device that recovers the exhaust heat of the engine and transmits it to the cooling water;
A first water pump for circulating cooling water through the exhaust heat recovery passage;
A second water pump for circulating cooling water through the engine cooling water passage;
A main heater core that transfers heat of the cooling water to the air;
Auxiliary heater core that transmits heat of cooling water to air with a smaller heat dissipation amount than the main heater core,
A first circulation path for connecting the auxiliary heater core without connecting the engine cooling water path to the exhaust heat recovery path; and a main heater core without connecting the engine cooling water path to the exhaust heat recovery path. A vehicle heating device, comprising: a path switching unit that switches between a second circulation path to be connected.   In the early stage of warm-up operation of the engine, switching to the first circulation path, circulating cooling water to the first circulation path by the first water pump, and then switching to the second circulation path by the path switching unit. The vehicle heating device according to claim 1, wherein the first water pump is configured to circulate cooling water through the second circulation path.   Based on the fact that the exhaust heat recovery amount of the exhaust heat recovery device is equal to or greater than a predetermined exhaust heat recovery amount in the early stage of warm-up operation of the engine, the path switching unit causes the second circulation to be performed from the first circulation path. The vehicle heating device according to claim 2, wherein the vehicle heating device is configured to switch to a route. The path switching unit is further configured to be switchable to a third circulation path in which the main heater core and the engine cooling water path are connected to the exhaust heat recovery path,
4. The engine according to claim 2, wherein the engine is configured to switch to the third circulation path and to circulate cooling water to the third circulation path by the second water pump in the middle of warm-up operation of the engine. Vehicle heating device. A radiator connected in parallel to the engine coolant passage;
A valve member that is disposed between the engine coolant passage and the radiator and that opens when the coolant rises to a temperature equal to or higher than a threshold temperature;
When the warm-up operation of the engine is completed, the cooling water flowing through the third circulation path rises to a temperature equal to or higher than the threshold temperature, whereby the valve member is opened, and the third circulation path The vehicle heating device according to claim 4, wherein a fourth circulation path to which the radiator is connected is formed, and cooling water is circulated through the fourth circulation path by the second water pump. .   In the middle period of warm-up operation of the engine, the first water pump circulates cooling water through the first circulation path, and is provided independently of the first circulation path. The engine cooling water passage and the main heater core And control the flow of the cooling water through the second water pump to the fifth circulation path connected to the third circulation path, switch to the third circulation path, and supply the cooling water to the third circulation path by the second water pump. The vehicle heating device according to claim 4 or 5, wherein the vehicle heating device is configured to be distributed.

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