JP2009041444A - Exhaust heat recovery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust heat recovery device restraining change of operation characteristics of a valve mechanism. <P>SOLUTION: The device comprises: an evaporator 110 provided in an exhaust conduit 11 for evaporating an operation medium sealed inside thereof by heating by heat exchange with an exhaust gas; a condenser 120 provided in an exhaust heat recovery circuit 30 for condensing the operation medium by heat exchange of the operation medium evaporated by the evaporator 110 with cooling water, and heating the cooling water; a steam pipe 102 for having the operation medium evaporated by the evaporator 110 flow into the condenser 120; a reflux pipe 103 for having the operation medium condensed by the condenser 120 reflux to the evaporator 110; a communication channel 133 for communication between the condenser 120 and the reflux pipe 103; a diaphragm 134 to be displaced according to the internal pressure of the communication channel 133; and an internal pressure operation valve 130 having a valve body 138 connected with the diaphragm 134 for switching the communication channel 133. The internal pressure operation valve 130 is provided so that the diaphragm 134 is disposed toward the exhaust conduit 11 downstream side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust heat recovery device that recovers exhaust heat discharged from an internal combustion engine.

  Patent Document 1 discloses an exhaust heat recovery device using a heat pipe. This exhaust heat recovery device is mounted on a vehicle equipped with a water-cooled engine, and has a loop heat pipe that recovers exhaust heat from the engine and heats engine coolant. The heat pipe condenses the working medium by heat exchange between the evaporating part that heats and evaporates the working medium enclosed inside by heat exchange with the exhaust, and the working medium evaporated in the evaporating part and the engine cooling water. And a condensing part for heating the engine cooling water. The evaporator is provided in the middle of an exhaust pipe extending from the engine toward the rear of the vehicle. The condensing part is provided in the side of the evaporation part in the middle of the cooling water circuit which distribute | circulates engine cooling water. The working medium evaporated in the evaporating unit flows into the condensing unit through the vapor pipe, and the working medium condensed in the condensing unit returns to the evaporating unit through the reflux pipe.

A diaphragm type valve mechanism is provided downstream of the condensing unit. This valve mechanism includes a valve body that opens and closes a flow path from the condensing unit to the evaporation unit, and a metal diaphragm (reversing plate) that displaces the valve body in a predetermined direction based on the internal pressure of the heat pipe. . As a result, the valve mechanism closes when the internal pressure of the heat pipe rises and exceeds a predetermined valve closing pressure, and opens again when the internal pressure decreases and falls below a predetermined valve opening pressure lower than the valve closing pressure. It has become. When the internal pressure of the heat pipe rises, the valve mechanism closes to prevent the working medium from recirculating and the vaporization in the evaporation section stops, so that the rise of the internal pressure of the heat pipe is suppressed.
JP 2007-170299 A

  However, in the configuration as described above, since the valve mechanism is arranged in an environment where the ambient temperature is high and the heat radiation from the exhaust pipe is high, the physical properties such as softening occur in the diaphragm, and the operating characteristics of the valve mechanism change. Problem arises. If the operating characteristics of the valve mechanism change, the valve mechanism may close before the internal pressure of the heat pipe reaches the valve closing pressure, and exhaust heat recovery efficiency may be reduced.

  An object of the present invention is to provide an exhaust heat recovery device that can suppress a change in operating characteristics of a valve mechanism.

  In order to achieve the above object, the present invention employs the following technical means.

  The invention according to claim 1 includes an exhaust pipe (11) through which exhaust gas discharged from the internal combustion engine (10) flows, and a cooling water circuit (30) through which cooling water for cooling the internal combustion engine (10) flows. An exhaust heat recovery device mounted on a vehicle equipped with an evaporation unit (110) provided in an exhaust pipe (11) and configured to heat and evaporate a working medium enclosed therein by heat exchange with exhaust gas, A condensing unit (120) that is provided in the cooling water circuit (30), condenses the working medium by heat exchange between the working medium evaporated in the evaporation unit (110) and the cooling water, and heats the cooling water, and the evaporation unit (110). ), The steam pipe (102) for flowing the working medium evaporated in the condensing part (120), the reflux pipe (103) for returning the working medium condensed in the condensing part (120) to the evaporating part (110), and the condensing part (120) and the reflux tube (103) The communication flow path (133) to be communicated, the atmosphere side space (132) maintained at atmospheric pressure, the communication flow path (133), and the atmosphere side space (132) are isolated and the internal pressure of the communication flow path (133). And a valve mechanism (130) including a diaphragm (134) that is displaced based on the valve and a valve body (138) that is connected to the diaphragm (134) and opens and closes the communication flow path (133). 130) is characterized in that the diaphragm (134) is provided so as to face the downstream side of the exhaust pipe (11).

  On the downstream side of the exhaust pipe (11), the exhaust gas whose temperature has decreased due to heat exchange with the working medium in the evaporation section (110) flows. For this reason, by providing the valve mechanism (130) so that the diaphragm (134) faces the downstream side of the exhaust pipe (11), the diaphragm (134) has a low ambient temperature and less heat radiation from the exhaust pipe (11). Located in the environment. Therefore, it is possible to suppress a change in the operating characteristics of the valve mechanism (130) due to a change in physical properties of the diaphragm (134).

  The invention according to claim 2 is characterized in that the condensing part (120) is arranged to be shifted downstream of the exhaust pipe (11) with respect to the evaporation part (110).

  Accordingly, since the valve mechanism (130) is arranged away from the upstream side of the exhaust pipe (11), the diaphragm (134) is arranged in an environment where the ambient temperature is low and the heat radiation from the exhaust pipe (11) is low. The Therefore, the change of the operation characteristic of the valve mechanism (130) due to the change of physical properties of the diaphragm (134) can be further suppressed.

  The invention according to claim 3 is characterized in that the condensing part (120) is arranged so as to overlap the exhaust pipe (11) when viewed in the vertical direction.

  As a result, the exhaust heat recovery device can be made thinner, so that the mounting property on the vehicle is improved.

  The invention according to claim 4 further includes a cap (150) provided with openings (151 and 152) for circulating air and attached to the atmosphere side space (132) side of the valve mechanism (130). It is characterized by that.

  Thereby, since heat radiation from the exhaust pipe (11) is blocked by the cap (150), the temperature rise of the diaphragm (134) can be suppressed. Further, it is possible to prevent water and foreign matter from entering the atmosphere side space (132).

  The invention according to claim 5 is characterized in that at least one opening (151) is provided in a lower portion of the cap (150).

  Thereby, even if water permeates into the cap (150), it can be drained to the outside from the opening (151).

  According to a sixth aspect of the present invention, the cap (150) has a maze structure (155) that complicates the flow path between the opening (151, 152) and the atmosphere side space (132). It is characterized by.

  Thereby, it can further suppress that water and a foreign material permeate into atmosphere side space (132).

  The invention described in claim 7 includes an exhaust pipe (11) through which exhaust gas discharged from the internal combustion engine (10) flows, and a cooling water circuit (30) through which cooling water for cooling the internal combustion engine (10) flows. An exhaust heat recovery device mounted on a vehicle equipped with an evaporation unit (110) provided in an exhaust pipe (11) and configured to heat and evaporate a working medium enclosed therein by heat exchange with exhaust gas, A condensing unit (120) that is provided in the cooling water circuit (30), condenses the working medium by heat exchange between the working medium evaporated in the evaporation unit (110) and the cooling water, and heats the cooling water, and the evaporation unit (110). ), The steam pipe (102) for flowing the working medium evaporated in the condensing part (120), the reflux pipe (103) for returning the working medium condensed in the condensing part (120) to the evaporating part (110), and the condensing part (120) and the reflux tube (103) The communication flow path (133) to be communicated, the atmosphere side space (132) maintained at atmospheric pressure, the communication flow path (133), and the atmosphere side space (132) are isolated and the internal pressure of the communication flow path (133). A valve mechanism (130) having a diaphragm (134) that is displaced based on the valve, a valve body (138) that is connected to the diaphragm (134) and opens and closes the communication channel (133), and an opening through which air flows (151, 152) and a cap (150) attached to the atmosphere side space (132) side of the valve mechanism (130).

  Thereby, since the heat radiation from the exhaust pipe (11) is blocked by the cap (150), the temperature rise of the diaphragm (134) can be suppressed. Therefore, it is possible to suppress a change in the operating characteristics of the valve mechanism (130) due to a change in physical properties of the diaphragm (134). Further, it is possible to prevent water and foreign matter from entering the atmosphere side space (132).

  Here, the reference numerals in parentheses of the above means indicate an example of a correspondence relationship with specific means described in the embodiments described later.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing a state in which the exhaust heat recovery device of the present embodiment is mounted on a vehicle. In FIG. 1, the flow direction of engine cooling water is indicated by arrows. As shown in FIG. 1, the vehicle on which the exhaust heat recovery apparatus 100 is mounted includes a water-cooled engine (internal combustion engine) 10 as a driving source for traveling. An exhaust pipe 11 for discharging exhaust from the engine 10 to the outside is connected to the engine 10. The exhaust pipe 11 extends toward the rear of the vehicle. In the middle of the exhaust pipe 11, a catalytic converter 12 for purifying the exhaust gas flowing through the exhaust pipe 11 is interposed. Further, a duct portion 13 of an exhaust heat recovery device 100 described later is provided in the exhaust pipe 11 on the downstream side of the catalytic converter 12. In the present specification, the exhaust pipe 11 upstream of the duct portion 13 is also referred to as an upstream exhaust pipe 11a, and the exhaust pipe 11 downstream of the duct portion 13 is also referred to as a downstream exhaust pipe 11b.

  A radiator circuit 20, an exhaust heat recovery circuit 30, and a heater circuit 40 are connected to the engine 10 as a cooling water circuit. In the radiator circuit 20, the exhaust heat recovery circuit 30 and the heater circuit 40, engine coolant for cooling the engine 10 is circulated by, for example, an engine-driven water pump 22. For example, LLC is used as the engine cooling water.

  The radiator circuit 20 is provided with a radiator 21 that cools the engine coolant by heat exchange with the outside air, and a bypass passage 23 that bypasses the radiator 21 and distributes the engine coolant. The flow rate of the engine cooling water passing through the radiator 21 and the flow rate of the engine cooling water passing through the bypass passage 23 are adjusted by a thermostat 24.

  The exhaust heat recovery circuit 30 branches off from the radiator circuit 20 at the engine outlet, and is joined to the radiator circuit 20 by the water pump 22. In the middle of the exhaust heat recovery circuit 30, a water tank 31 of the exhaust heat recovery apparatus 100 described later is provided.

  The heater circuit 40 is a circuit in which engine cooling water (hot water) flows out from a portion different from the engine outlet of the radiator circuit 20 and joins the exhaust heat recovery circuit 30 on the downstream side of the exhaust heat recovery device 100. The heater circuit 40 is provided with a heater core 41 as a heat exchanger for heating. The heater core 41 is disposed in an air conditioning case of an air conditioning unit (not shown), and heats conditioned air blown by a blower by heat exchange with engine cooling water.

  FIG. 2 is a schematic diagram showing the configuration of the exhaust heat recovery apparatus 100 in the present embodiment. FIG. 3 is a cross-sectional view schematically showing the configuration of the exhaust heat recovery apparatus 100 cut along line III-III in FIG. The left-right direction in FIG. 2 generally represents the front-rear direction of the vehicle, and the up-down direction represents the left-right direction of the vehicle. A thick arrow in FIG. 2 represents the flow direction of the exhaust gas. Further, the vertical direction in FIG. 3 generally represents the vertical vertical direction. The solid arrow in FIG. 3 represents the flow direction of the working medium in the liquid state, the broken arrow represents the flow direction of the working medium in the gas state, and the thick arrow represents the flow direction of the engine coolant.

  As shown in FIGS. 2 and 3, the exhaust heat recovery apparatus 100 includes a loop heat pipe 101 that recovers exhaust heat exhausted from the engine 10 and heats engine cooling water. The heat pipe 101 is provided with a sealing portion (not shown) used when the working medium is sealed inside. The sealing portion is sealed after the inside of the heat pipe 101 is decompressed and the working medium is injected. As the working medium, water, alcohol, fluorocarbon, chlorofluorocarbon (fluorocarbon) or the like is used.

  The heat pipe 101 includes an evaporation unit 110 that heats and evaporates the working medium sealed inside by heat exchange with exhaust gas. The evaporation part 110 is provided in a duct part 13 interposed in the middle of the exhaust pipe 11.

  The evaporation unit 110 has a structure in which a plurality of flat tubes 111 each extending in a substantially vertical direction are stacked in a horizontal direction with a gap 112 interposed therebetween. The gap 112 functions as an exhaust passage through which exhaust flows. The gap 112 is provided with a corrugated fin 113 that is thermally connected to the outer wall surface of the flat tube 111. The fin 113 facilitates heat exchange between the exhaust gas flowing through the gap 112 and the working medium flowing through the flat tube 111.

  A flat container-like lower tank 114 is connected to the lower end of each flat tube 111. A flat container-like upper tank 115 is connected to the upper end of each flat tube 111. The lower tank 114 and the upper tank 115 are communicated with each other via each flat tube 111.

  The heat pipe 101 also has a condensing unit 120 that cools and condenses the working medium and heats the engine cooling water by heat exchange between the working medium evaporated in the evaporation unit 110 and the cooling water. The condensing unit 120 is accommodated in a water tank 31 provided in the exhaust heat recovery circuit 30.

  The condensing unit 120 has a plurality of flat tubes 121 that extend substantially in the vertical direction and are stacked in the horizontal direction. A lower tank 124 is connected to the lower end of each flat tube 121, and an upper tank 125 is connected to the upper end of each flat tube 121. In the lower tank 124 on the downstream side of the condensing unit 120, an internal pressure operation valve 130 described later is provided.

  Below the side surface of the water tank 31, an introduction pipe 32 for introducing engine cooling water flowing through the exhaust heat recovery circuit 30 into the water tank 31 is provided. In addition, an outlet pipe 33 for leading the engine coolant in the water tank 31 to the exhaust heat recovery circuit 30 is provided above the side surface of the water tank 31.

  The upper tank 115 on the evaporation unit 110 side and the upper tank 125 on the condensing unit 120 side communicate with each other by a steam pipe 102 that passes through the duct unit 13 and the water tank 31. Further, the internal pressure operation valve 130 and the flat tube 111 of the evaporation unit 110 are communicated with each other by a reflux pipe 103 that penetrates the water tank 31 and the duct part 13 and has a smaller diameter than the steam pipe 102. Accordingly, the lower tank 114, the flat tube 111, the upper tank 115, the steam pipe 102, the upper tank 125, the flat tube 121, the lower tank 124, the internal pressure operation valve 130, the return pipe 103, the flat tube 111, and the lower tank 114 are arranged in this order. It is connected in an annular shape and circulates the internal working medium.

  Each member constituting the heat pipe 101 is made of stainless steel having high corrosion resistance. After the members are assembled with each other, the members are integrally brazed with a brazing material provided at the contact portion or the fitting portion.

  FIG. 4 is a cross-sectional view showing the configuration of the internal pressure operating valve 130 in more detail. As shown in FIG. 4, the internal pressure operating valve 130 has a substantially cylindrical main body 131. The main body 131 is inserted into the inside from the side surface of the lower tank 124, and one end 131 a protrudes from the side surface of the lower tank 124. A vent hole 135 is formed in the bottom surface of the end 131a. A condensate inflow hole 136 through which the working medium condensed in the condensing unit 120 flows into the main body 131 from the lower tank 124 is formed on the side surface of the main body 131. In addition, a condensed water outflow hole 137 through which the working medium that has flowed into the main body 131 flows into the reflux pipe 103 is formed at the other end of the main body 131 (see FIG. 3).

  In the main body 131, the atmosphere side space 132 that communicates with the atmosphere side through the vent hole 135 and is maintained at atmospheric pressure, and the lower tank 124 circulates through the condensed water inflow hole 136 and the condensed water outflow hole 137. A communication channel 133 that communicates with the tube 103 is formed. The atmosphere side space 132 and the communication flow path 133 are isolated by a diaphragm 134.

  The diaphragm 134 has a substantially thin disk shape in which the vicinity of the center portion is convex toward one surface side. The outer peripheral part of the diaphragm 134 is fixed by the inner wall part of the main body part 131. Moreover, the diaphragm 134 is urged | biased toward the communicating flow path 133 side by elastic members (not shown), such as a spring. Between the condensed water inflow hole 136 and the condensed water outflow hole 137 in the main body 131, a gate portion (valve seat) 139 having a substantially circular opening hole 140 at the center is formed.

  A valve body 138 that opens and closes the gate portion 139 is provided in the communication flow path 133. The valve body 138 is a substantially circular flat member having a diameter larger than that of the opening hole 140 of the gate portion 139, and is disposed to face the left side surface of the gate portion 139. The valve body 138 is connected to the central portion of the diaphragm 134 through a rod-shaped valve shaft 141 having a diameter smaller than that of the opening hole 140.

  The diaphragm 134 is applied from the left side in FIG. 4 by the atmospheric pressure and the biasing force of the elastic member from the atmosphere-side space 132 side, and from the communication channel 133 side by the internal pressure of the heat pipe 101 (communication channel 133). 4 Displacement in the left-right direction due to the balance with the rightward force. With the displacement of the center portion of the diaphragm 134, the valve body 138 is displaced in the left-right direction in FIG.

  Thus, the internal pressure operation valve 130 functions as a diaphragm type valve that opens and closes the communication flow path 133 in accordance with the internal pressure of the heat pipe 101. Specifically, in a normal state where the internal pressure of the heat pipe 101 is less than a predetermined valve closing pressure Pi1, the communication channel 133 is in an open state. When the internal pressure of the heat pipe 101 rises and becomes equal to or higher than the valve closing pressure Pi1, the valve body 138 is displaced in the right direction and the communication flow path 133 is closed. Further, when the internal pressure of the heat pipe 101 decreases from the closed state of the communication channel 133 to a predetermined valve opening pressure Pi2 (Pi1> Pi2) lower than the valve closing pressure Pi1, the communication channel 133 is opened again. It becomes a state. In FIG. 4, the valve body 138 and the diaphragm 134 in a state where the communication channel 133 is opened are indicated by solid lines, and the diaphragm 134 and the communication channel 133 are displaced in the right direction so that the communication channel 133 is closed. The valve body 138 and the diaphragm 134 in the state are indicated by broken lines.

  The internal pressure operation valve 130 of the present embodiment is provided such that the diaphragm 134 faces the downstream side (vehicle rear side) of the exhaust pipe 11. That is, the internal pressure operation valve 130 is inserted into the lower tank 124 in a direction substantially parallel to the extending direction of the exhaust pipe 11 and from the downstream side to the upstream side of the exhaust pipe 11. Thereby, the distance between the diaphragm 134 and the downstream side exhaust pipe 11b becomes comparatively short, and the distance between the diaphragm 134 and the upstream side exhaust pipe 11a becomes longer. The displacement direction of the valve body 138 and the diaphragm 134 and the extending direction of the exhaust pipe 11 are substantially parallel.

  In addition, a cap 150 is attached to an end 131 a that protrudes from the side surface of the lower tank 124 and is exposed to the outside in the main body 131 of the internal pressure operating valve 130. The cap 150 includes a main body portion 156 having a cylindrical shape that covers the end portion 131a, and a flange portion 157 that contacts the side surface of the lower tank 124. The cap 150 is made of stainless steel like the members of the internal pressure operation valve 130, for example. On the side surface of the main body 156 of the cap 150, for example, a plurality of openings 151 and 152 are formed to allow air to flow in order to maintain the atmosphere-side space 132 of the internal pressure operation valve 130 at atmospheric pressure. Among these, one opening 151 is formed in the lower part of the side surface of the main body 156 of the cap 150 so as to face vertically downward.

  A maze structure 155 such as a protrusion 154 is formed on the bottom surface of the main body 156. The flow path through which air flows between the openings 151 and 152 and the vent hole 135 is complicated by the maze structure 155.

  On the inner wall surface of the main body portion 156, a protruding press-fit portion 153 protruding inward is formed. When the cap 150 is attached to the end 131a of the internal pressure operating valve 130, the cap 150 is positioned in the circumferential direction so that the opening 151 (or 152) faces vertically downward, and press-fitted into the end 131a. It has become. The cap 150 is positioned in the axial direction by bringing the flange portion into contact with the side surface of the lower tank 124. Thereby, the cap 150 can be easily attached and fixed to the internal pressure operation valve 130.

  Next, the operation of the exhaust heat recovery apparatus of this embodiment will be described.

  When the engine 10 is started, the water pump 22 is activated, and the engine coolant circulates through the radiator circuit 20, the exhaust heat recovery circuit 30, and the heater circuit 40. Exhaust gas from the engine 10 flows through the exhaust pipe 11, passes through the catalytic converter 12 and the duct part 13 (evaporation part 110), and is discharged into the atmosphere. Further, the engine cooling water circulating in the exhaust heat recovery circuit 30 passes through the water tank 31 (condenser 120) of the exhaust heat recovery apparatus 100. The internal pressure of the heat pipe 101 is relatively low when the engine 10 is started, and gradually increases with the operation of the engine 10.

  In the evaporation section 110 of the heat pipe 101, the working medium is heated and evaporated by heat exchange with the exhaust. The working medium that has become vapor rises in the flat tube 111 and flows into the condensing unit 120 through the vapor pipe 102.

  In the condensing unit 120, the working medium is cooled and condensed by heat exchange between the working medium and the engine cooling water, and the engine cooling water is heated. When the internal pressure of the heat pipe 101 is less than the valve closing pressure Pi 1 of the internal pressure operation valve 130, the communication flow path 133 is open, so that the condensed working fluid flows down in the flat tube 121 and evaporates through the reflux pipe 103. Return to section 110.

  As described above, the exhaust heat discharged from the engine 10 is transported from the evaporation unit 110 to the condensing unit 120 by the working medium, and is released as condensation latent heat when the working medium condenses in the condensing unit 120. As a result, the engine coolant flowing through the exhaust heat recovery circuit 30 is positively heated, so that warm-up of the engine 10 is promoted and the heating performance using the engine coolant is improved.

  When the internal pressure of the heat pipe 101 rises and becomes equal to or higher than the valve closing pressure Pi1, the diaphragm 134 and the valve body 138 of the internal pressure operating valve 130 are displaced to the right in FIG. 4, and the communication flow path 133 is closed. Thereby, the return of the working fluid condensed in the condensing unit 120 to the evaporation unit 110 is prevented. For this reason, when all the working fluid remaining in the evaporation unit 110 evaporates, the recovery of the exhaust heat stops, and the condensed working medium is stored on the condensing unit 120 side. In this state, the internal pressure of the heat pipe 101 gradually decreases.

  When the internal pressure of the heat pipe 101 decreases and becomes equal to or less than the valve opening pressure Pi2, the diaphragm 134 and the valve body 138 return to the left in FIG. 4, and the communication flow path 133 is opened again. Thereby, the return of the working fluid condensed in the condensing unit 120 to the evaporation unit 110 is resumed, and the recovery of the exhaust heat is resumed.

  Here, the temperature of the exhaust in the exhaust pipe 11 is lowered by heat exchange with the working medium in the evaporation unit 110. For this reason, the downstream exhaust pipe 11b on the downstream side of the evaporation section 110 (the duct section 13) has a lower temperature than the upstream exhaust pipe 11a on the upstream side of the evaporation section 110. In the present embodiment, the diaphragm 134 of the internal pressure operating valve 130 is provided toward the downstream side of the exhaust pipe 11. Accordingly, the distance between the high temperature upstream exhaust pipe 11a and the diaphragm 134 can be increased, and the communication channel 133 and the like can be interposed between the upstream exhaust pipe 11a and the diaphragm 134. For this reason, the diaphragm 134 is disposed in an environment where the ambient temperature is relatively low and the heat radiation from the exhaust pipe 11 is small. Therefore, since the temperature rise of the diaphragm 134 is suppressed, a change in the operating characteristics of the internal pressure operating valve 130 can be suppressed.

  In the present embodiment, a cap 150 is attached to the end 131 a of the internal pressure operation valve 130. Thereby, since the heat radiation from the exhaust pipe 11 is blocked by the cap 150, the temperature rise of the diaphragm 134 can be suppressed.

  Furthermore, in this embodiment, even if the internal pressure operation valve 130 is installed under the floor of the vehicle body, the cap 150 can prevent water and foreign matter from entering the inside. Accordingly, it is possible to prevent the ventilation hole 135 from being blocked by water or foreign matter and adversely affecting the operation of the internal pressure operation valve 130.

  In the present embodiment, an opening 151 through which air is circulated is formed in the lower part of the side surface of the main body 156 of the cap 150. Thereby, since the opening part 151 functions also as a drain outlet, even if water infiltrates into the cap 150, it can drain from the opening part 151 outside.

  Furthermore, in this embodiment, the flow path between the openings 151 and 152 of the cap 150 and the atmosphere side space 132 of the internal pressure operation valve 130 is complicated by the maze structure 155. Thereby, it can further suppress that water and a foreign material enter the atmosphere side space 132.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic diagram showing the configuration of the exhaust heat recovery apparatus 104 in the present embodiment. The left-right direction in FIG. 5 generally represents the front-rear direction of the vehicle, and the up-down direction represents the left-right direction of the vehicle. As shown in FIG. 5, in the present embodiment, the condensing part 120 of the heat pipe 101 is arranged so as to be shifted downstream of the exhaust pipe 11 with respect to the evaporation part 110. Thereby, the distance between the condensation part 120 and the downstream exhaust pipe 11b is comparatively short, and the distance between the condensation part 120 and the upstream exhaust pipe 11a is longer than it.

  The steam pipe 102 and the reflux pipe 103 that connect between the evaporator 110 and the condenser 120 are both bent substantially vertically. The vaporization part 110 side of the steam pipe 102 and the reflux pipe 103 extends substantially perpendicular to the extending direction of the exhaust pipe 11 (vehicle left-right direction), and the condensing part 120 side is substantially parallel to the extending direction of the exhaust pipe 11 (vehicle longitudinal direction). It extends.

  The internal pressure operating valve 130 is provided so that the diaphragm 134 faces the downstream side of the exhaust pipe 11 as in the first embodiment. In the present embodiment, since the condensing part 120 is arranged so as to be shifted downstream of the exhaust pipe 11, the distance between the upstream exhaust pipe 11a and the diaphragm 134 can be made longer than in the first embodiment. Therefore, the ambient temperature of the diaphragm 134 can be further lowered, and the heat radiation from the upstream side exhaust pipe 11a to the diaphragm 134 can be further reduced. Therefore, since a change in physical properties due to heat of the diaphragm 134 can be suppressed, a change in operating characteristics of the internal pressure operating valve 130 can be suppressed.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic diagram showing a configuration of the exhaust heat recovery apparatus 105 in the present embodiment. FIG. 6A shows a configuration of the exhaust heat recovery device 105 viewed from the left side of the vehicle, and FIG. 6B shows a configuration of the exhaust heat recovery device 105 viewed from the rear of the vehicle. The vertical direction in FIGS. 6A and 6B represents the vertical vertical direction, the horizontal direction in FIG. 6A represents the longitudinal direction of the vehicle, and the horizontal direction in FIG. 6B represents the lateral direction of the vehicle. Represents.

  As shown in FIG. 6, in the present embodiment, the condensing unit 120 is arranged to be shifted to the downstream side of the exhaust pipe 11 with respect to the evaporation unit 110, and the condensing part 120 is downstream of the exhaust pipe 11 b as viewed in the vertical direction. It is arranged to overlap. Therefore, according to the present embodiment, the same effects as those of the second embodiment can be obtained, and the exhaust heat recovery device 105 can be thinned in the left-right direction of the vehicle.

(Other embodiments)
In the above embodiment, the cap 150 is fixed by being press-fitted into the internal pressure operating valve 130. However, the cap 150 may be fixed to the internal pressure operating valve 130 using a fastening member such as a screw.

It is a schematic diagram which shows the mounting state to the vehicle of the exhaust heat recovery apparatus in 1st Embodiment. It is a schematic diagram which shows the structure of the exhaust heat recovery apparatus in 1st Embodiment. It is sectional drawing which shows the structure of the exhaust-heat recovery apparatus cut | disconnected by the III-III line | wire of FIG. It is sectional drawing which expands and shows an internal pressure operating valve. It is a schematic diagram which shows the structure of the exhaust heat recovery apparatus in 2nd Embodiment. It is a schematic diagram which shows the structure of the exhaust heat recovery apparatus in 3rd Embodiment.

Explanation of symbols

10 Engine (Internal combustion engine)
11 Exhaust pipe 30 Exhaust heat recovery circuit (cooling water circuit)
DESCRIPTION OF SYMBOLS 100 Exhaust heat recovery apparatus 101 Heat pipe 102 Steam pipe 103 Recirculation pipe 110 Evaporating part 120 Condensing part 130 Internal pressure operation valve (valve mechanism)
132 atmosphere side space 133 communication channel 134 diaphragm 138 valve body 150 cap 151, 152 opening 155 labyrinth structure

Claims (7)

Exhaust gas mounted on a vehicle including an exhaust pipe (11) through which exhaust gas discharged from the internal combustion engine (10) flows and a cooling water circuit (30) through which cooling water for cooling the internal combustion engine (10) flows. A heat recovery device,
An evaporation section (110) provided in the exhaust pipe (11) and configured to heat and evaporate the working medium enclosed inside by heat exchange with the exhaust;
A condensing unit (120) provided in the cooling water circuit (30) for condensing the working medium by heat exchange between the working medium evaporated in the evaporation unit (110) and the cooling water and heating the cooling water; ,
A steam pipe (102) for allowing the working medium evaporated in the evaporation section (110) to flow into the condensation section (120);
A reflux pipe (103) for refluxing the working medium condensed in the condenser (120) to the evaporator (110);
A communication channel (133) for communicating the condenser (120) and the reflux pipe (103), an atmosphere side space (132) maintained at atmospheric pressure, the communication channel (133), and the atmosphere side A diaphragm (134) that isolates the space (132) and is displaced based on an internal pressure of the communication channel (133), and a valve body that is connected to the diaphragm (134) and opens and closes the communication channel (133). (138) with a valve mechanism (130),
The exhaust heat recovery apparatus according to claim 1, wherein the valve mechanism (130) is provided so that the diaphragm (134) faces the downstream side of the exhaust pipe (11).   The exhaust heat recovery device according to claim 1, wherein the condensing unit (120) is arranged to be shifted downstream of the exhaust pipe (11) with respect to the evaporation unit (110).   The exhaust heat recovery apparatus according to claim 2, wherein the condensing part (120) is disposed so as to overlap the exhaust pipe (11) when viewed in the vertical direction.   An opening (151, 152) through which air is circulated, and further comprising a cap (150) attached to the atmosphere side space (132) side of the valve mechanism (130). The exhaust heat recovery apparatus according to any one of 1 to 3.   The exhaust heat recovery device according to claim 4, wherein the at least one opening (151) is provided in a lower portion of the cap (150).   The cap (150) has a maze structure (155) that complicates a flow path between the opening (151, 152) and the atmosphere side space (132). The exhaust heat recovery apparatus according to 4 or 5. Exhaust gas mounted on a vehicle including an exhaust pipe (11) through which exhaust gas discharged from the internal combustion engine (10) flows and a cooling water circuit (30) through which cooling water for cooling the internal combustion engine (10) flows. A heat recovery device,
An evaporation section (110) provided in the exhaust pipe (11) and configured to heat and evaporate the working medium enclosed inside by heat exchange with the exhaust;
A condensing unit (120) provided in the cooling water circuit (30) for condensing the working medium by heat exchange between the working medium evaporated in the evaporation unit (110) and the cooling water and heating the cooling water; ,
A steam pipe (102) for allowing the working medium evaporated in the evaporation section (110) to flow into the condensation section (120);
A reflux pipe (103) for refluxing the working medium condensed in the condenser (120) to the evaporator (110);
A communication channel (133) for communicating the condenser (120) and the reflux pipe (103), an atmosphere side space (132) maintained at atmospheric pressure, the communication channel (133), and the atmosphere side A diaphragm (134) that isolates the space (132) and is displaced based on an internal pressure of the communication channel (133), and a valve body that is connected to the diaphragm (134) and opens and closes the communication channel (133). A valve mechanism (130) comprising (138),
An exhaust heat recovery apparatus comprising an opening (151, 152) for circulating air and a cap (150) attached to the atmosphere side space (132) side of the valve mechanism (130).

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