JP2016014382A - Exhaust heat recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust heat recovery device capable of preventing the leakage of a heat medium to outside of a heat medium flow passage by heat damage from an exhaust system.SOLUTION: An exhaust heat recovery device 100 comprises: a heat exchange unit 10 implementing heat exchange with exhaust gas discharged from an engine; a bypass unit 20 causing the exhaust gas to bypass the heat exchange unit 10; a valve 50 distributing the exhaust gas to the heat exchange unit 10 and the bypass unit 20; and a valve switchover mechanism 60 rotating the valve 50. The heat exchange unit 10 includes a heat medium flow passage 11 in which a heat medium for the heat exchange with the exhaust gas circulates. The valve switchover mechanism 60 includes a temperature sensor 61 disposed apart from the heat medium and responding to heat of the heat medium; and an actuator 62 rotating the valve 50 by the response of the temperature sensor 61.

Description

  The present invention relates to an exhaust heat recovery device including a valve switching mechanism.

  Patent Document 1 discloses a valve switching mechanism of an exhaust heat recovery device that rotates a valve provided in the exhaust heat recovery device according to the heat of the heat medium circulating in the heat medium flow path of the exhaust heat recovery device. . The valve switching mechanism of the exhaust heat recovery device of Patent Document 1 uses an actuator that is operated by the heat of the heat medium, and the thermal expansion body in the element of the actuator expands and contracts by the heat of the heat medium. Moves back and forth to switch valves.

JP 2010-31669 A

  However, in the valve switching mechanism described in Patent Document 1, the actuator element is installed in the heat medium flow path in order to respond to the heat of the circulating heat medium, and is sealed with a rubber O-ring. For this reason, there is a problem that the heat medium leaks to the outside of the heat medium flow path when the seal deteriorates or breaks due to heat damage from the exhaust system.

  The present invention was invented to solve such problems, and an object thereof is to provide an exhaust heat recovery device in which the heat medium does not leak outside the heat medium flow path due to heat damage from the exhaust system. To do.

  An exhaust heat recovery device according to an aspect of the present invention includes a heat exchange unit that exchanges heat with exhaust discharged from an engine, and a bypass unit that bypasses the exhaust from the heat exchange unit. The exhaust heat recovery device includes a valve that distributes the exhaust gas to the heat exchange unit and the bypass unit, and a valve switching mechanism that rotates the valve. The heat exchange unit includes a heat medium flow path through which a heat medium for exchanging heat with the exhaust gas circulates. The valve switching mechanism includes a temperature sensor serving as a heat response unit that is arranged apart from the heat medium and responds with heat from the heat medium, and an actuator serving as an operation unit that rotates the valve according to the response of the temperature sensor.

  According to this aspect, since the actuator element is not directly installed in the heat medium flow path circulating through the exhaust heat recovery device body, there is no need to use a seal that may be deteriorated or damaged, and heat from the exhaust system is eliminated. The heat medium can be prevented from leaking outside due to harm.

It is a perspective view of the waste heat recovery device of a 1st embodiment of the present invention. It is a figure which shows the state of the valve | bulb in the case of introduce | transducing exhaust_gas | exhaustion into the heat exchange part which concerns on a certain aspect of this invention. It is a figure which shows the state of the valve | bulb when introducing exhaust_gas | exhaustion into the bypass part which concerns on a certain aspect of this invention. It is a structure figure when the inside of the heat exchange part of 1st Embodiment is seen from the side. 3B is a cross-sectional view taken along line IIIb-IIIb in FIG. 3A. FIG. It is a perspective view of the waste heat recovery device of a 2nd embodiment of the present invention. It is a structural diagram when the inside of the actuator of 2nd Embodiment is seen from the side. It is a cross-sectional view which follows the Vb-Vb line | wire of FIG. 5A. It is a modification of the internal structure of the actuator of 2nd Embodiment. FIG. 6B is a cross-sectional view taken along line VIb-VIb in FIG. 6A.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view of the exhaust heat recovery device 100 of the present embodiment. The exhaust heat recovery device 100 includes a heat exchange unit 10 that exchanges heat with exhaust, a bypass unit 20 that bypasses without exchanging heat, an exhaust introduction unit 30, and an exhaust discharge unit 40. The exhaust heat recovery device 100 includes a valve 50 that distributes exhaust gas to the heat exchange unit 10 and the bypass unit 20, a valve switching mechanism 60 that controls the rotation of the valve 50, a controller 70 that controls the operation of the actuator 62, Is provided. The outer peripheries of the heat exchange unit 10 and the bypass unit 20 are surrounded by the outer wall 101 of the exhaust heat recovery unit 100. The outer wall portion 101 is formed of a thin metal material or the like so as to improve heat transferability. A concave portion 101 a that is recessed toward the heat exchange unit 10 is formed in the outer wall 101 that is located outside the heat exchange unit 10.

  The heat exchange unit 10 performs heat exchange between the circulating heat medium and the exhaust gas that has flowed. The heat exchanging unit 10 includes an exhaust heat recovery device inlet channel 11 a that allows a heat medium to flow into the heat exchange unit 10, and an exhaust heat recovery device outlet channel 11 b that allows the heat medium to flow out of the heat exchange unit 10. . The heat medium is engine cooling water or cooling water having a cycle independent of engine cooling water, and for example, LLC is used. The heat medium whose temperature has been increased by heat exchange is used for heating the passenger compartment or warming up the engine.

  The bypass unit 20 is arranged in parallel with the heat exchange unit 10. The exhaust gas that has flowed in can be bypassed to the bypass unit 20, and can flow to the exhaust discharge unit 40 without performing heat exchange in the heat exchange unit 10.

  The exhaust introduction unit 30 is an inlet that is disposed upstream of the heat exchange unit 10 and the bypass unit 20 and introduces exhaust exhausted from the engine into the exhaust heat recovery unit 100. Exhaust gas introduced from the exhaust gas introduction unit 30 passes through the heat exchange unit 10 or the bypass unit 20 and flows to the exhaust gas discharge unit 40.

  The exhaust exhaust unit 40 is an outlet that is disposed downstream of the heat exchange unit 10 and the bypass unit 20 and exhausts the exhaust gas that has passed through the heat exchange unit 10 or the bypass unit 20 to the outside of the exhaust heat recovery unit 100.

  The valve 50 is installed in the exhaust introduction unit 30 and rotates according to the operation of the valve switching mechanism 60 to distribute the exhaust exhausted from the engine to the heat exchange unit 10 and the bypass unit 20. As shown in FIGS. 2A and 2B, the valve 50 can be rotated about a rotation shaft 50a. Stoppers 51 and 2 for restricting the rotation of the valve 50 are formed in the exhaust introduction part 30. FIG. 2A is a diagram illustrating a state of the valve 50 when exhaust is introduced into the heat exchange unit 10, and FIG. 2B is a diagram illustrating a state of the valve 50 when exhaust is introduced into the bypass unit 20. When the exhaust gas is allowed to flow into the heat exchanging unit 10, the valve 50 comes into contact with the stopper 51 and the flow path to the bypass unit 20 is blocked as shown in FIG. 2A. On the other hand, when the exhaust gas is caused to flow into the bypass unit 20, the valve 50 comes into contact with the stopper 52 as shown in FIG. 2B, and the flow path to the heat exchange unit 10 is blocked.

  Returning to FIG. 1, the valve switching mechanism 60 includes a temperature sensor 61 installed in the recess 101 a of the outer wall 101 and an actuator 62 attached to the valve 50.

  The temperature sensor 61 is a sensor that measures the temperature of the heat medium via the concave portion 101 a of the outer wall portion 101. For example, the temperature sensor 61 is a thermistor, a thermocouple, or a platinum resistance thermometer.

  The actuator 62 is a device that rotates the valve 50 and is operated by, for example, hydraulic pressure, pneumatic pressure, or electric power.

  The controller 70 is configured by a microcomputer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). A response signal from the temperature sensor 61 that responds to the heat of the heat medium is input to the controller 70. Then, the controller 70 determines whether or not the actuator 62 is operable based on the response signal.

  Here, the internal structure of the heat exchange unit 10 and the valve switching mechanism 60 will be described with reference to FIGS. 3A and 3B. FIG. 3A is a structural view when the inside of the heat exchange unit 10 is viewed from the side, and FIG. 3B is a cross-sectional view taken along line IIIb-IIIb in FIG. 3A.

  As shown in FIG. 3A, a heat medium flow path 11 through which a heat medium circulates and an exhaust passage 12 through which exhaust gas flows are formed inside the heat exchange unit 10.

  The heat medium flow channel 11 circulates the heat medium introduced from the exhaust heat recovery device inlet flow channel 11a shown in FIG. The heat medium is discharged from the exhaust heat recovery device outlet flow path 11b after circulating through the heat medium flow path 11. As shown in FIG. 3A, the exhaust heat recovery device outlet channel 11 b passes through the outer wall portion 101 and the exhaust passage 12 and is connected to the outside of the exhaust heat recovery device 100.

  The exhaust passage 12 is a passage through which the exhaust gas flowing into the heat exchange unit 10 flows. The exhaust gas flowing into the heat exchange unit 10 exchanges heat with the heat medium circulating in the heat medium channel 11, and the exhaust gas after the heat exchange flows to the exhaust gas discharge unit 40. The exhaust passage 12 is formed between the heat medium flow paths 11 or between the outer wall portion 101 and the heat medium flow path 11. Alternatively, the exhaust passage 12 formed between the outer wall portion 101 and the heat medium passage 11 is partially blocked by the bottom portion of the recess 101 a formed in the outer wall portion 101 being in contact with the heat medium passage 11. Has been. The side of the recess 101a is formed obliquely with respect to the exhaust passage 12 so as not to give resistance to the exhaust flow.

  Thus, the recessed part 101a which obstruct | occludes a part of exhaust passage 12 is formed in the outer wall part 101 vicinity of the exhaust heat recovery device exit flow path 11b. The recess 101a and the exhaust heat recovery device outlet channel 11b are arranged so as to be aligned in the direction in which the exhaust gas flows in the exhaust passage 12, as shown in FIGS. 3A and 3B. The arrows in FIGS. 3A and 3B illustrate the flow of exhaust flowing through the exhaust passage 12. The recess 101a is located on the upstream side of the exhaust passage 12 with respect to the exhaust heat recovery device outlet channel 11b. The recess 101a is formed in a triangular shape with a corner facing the upstream side so as not to give resistance to the flow of exhaust. By making the recess 101a triangular, it is possible to guide the flow of exhaust gas, so that it is possible to suppress the exhaust heat recovery device outlet flow channel 11b located on the downstream side from interfering with the exhaust gas.

  A temperature sensor 61 is installed outside the bottom of the recess 101a. A gap formed between the temperature sensor 61 and the side portion of the recess 101a is a predetermined distance ΔS or more. The distance ΔS is set to a distance at which the temperature sensor 61 does not malfunction due to the heat effect of the exhaust flowing inside the side portion of the recess 101a. The heat of the heat medium flowing through the heat medium flow path 11 is transmitted to the temperature sensor 61 only through the bottom of the recess 101a. As shown in FIG. 3B, it is preferable that the recess 101a has a slightly rounded shape so that the installation area of the temperature sensor 61 and the distance ΔS can be easily secured.

  According to the exhaust heat recovery device 100 according to the first embodiment described above, the following effects can be obtained.

  The exhaust heat recovery device 100 according to the present embodiment includes a heat exchanging unit 10 that exchanges heat with the exhaust discharged from the engine, and a bypass unit 20 that bypasses the exhaust from the heat exchanging unit 10. The exhaust heat recovery device 100 includes a valve 50 that distributes exhaust gas to the heat exchange unit 10 and the bypass unit 20, and a valve switching mechanism 60 that rotates the valve 50. The heat exchange unit 10 includes a heat medium flow path 11 through which a heat medium for exchanging heat with the exhaust gas circulates. The valve switching mechanism 60 is disposed away from the heat medium, and a temperature sensor 61 serving as a heat response unit that responds by the heat of the heat medium, and an actuator 62 serving as an operation unit that rotates the valve 50 according to the response of the temperature sensor 61. And comprising.

  By adopting such a configuration, the temperature sensor 61 is disposed separately from the heat medium circulating in the heat medium flow path 11 and thus is not in contact with the heat medium. For this reason, it is not necessary to provide a seal that may be deteriorated or broken due to heat damage at a portion where the temperature sensor 61 and the heat medium are in contact with each other, and the heat medium can be prevented from leaking to the outside.

  The exhaust heat recovery device 100 according to the present embodiment includes an outer wall portion 101 formed on the outer periphery of the heat exchange portion 10. Further, the temperature sensor 61 of the valve switching mechanism 60 is placed in contact with the outer wall portion 101.

  With such a configuration, the temperature sensor 61 can accurately respond to the heat of the heat medium circulating in the heat medium flow path 11 inside the outer wall 101 via the outer wall 101.

  In the exhaust heat recovery device 100 according to the present embodiment, the heat exchanging unit 10 includes an exhaust passage 12 between the outer wall portion 101 and the heat medium passage 11. Further, in the exhaust heat recovery device 100 of the present embodiment, the outer wall portion 101 is formed with a recess 101 a that is recessed toward the exhaust passage 12 and comes into contact with the heat medium passage 11. In the recess 101a, the temperature sensor 61 is installed with a distance ΔS or more as a predetermined gap from the side of the recess 101a.

  Thus, since the temperature sensor 61 is installed in the recess 101a that contacts the heat medium flow path 11, it can respond to the heat of the heat medium flowing through the heat medium flow path 11 only through the bottom of the recess 101a. . Further, since the temperature sensor 61 is installed at a distance ΔS or more from the side of the recess 101a, the temperature sensor 61 malfunctions due to the heat effect of the exhaust gas flowing inside the side of the recess 101a. Can be prevented.

  In the exhaust heat recovery device 100 according to the present embodiment, an exhaust heat recovery device outlet flow channel 11 b through which the heat medium circulated in the exhaust heat recovery device 100 flows out to the heat medium flow channel 11 passes through the exhaust passage 12. Formed as follows. Further, the concave portion 101a of the outer wall portion 101 is formed in the vicinity of the exhaust heat recovery device outlet flow path 11b, and the concave portion 101a and the exhaust heat recovery device outlet flow channel 11b are arranged in the exhaust flow direction in the exhaust passage 12. Be placed.

  By setting it as such a structure, compared with the case where the recessed part 101a and the exhaust heat recovery device exit flow path 11b are arrange | positioned separately, it is hard to prevent the flow of exhaust gas, Therefore Exhaust gas can be flowed efficiently. Moreover, since the temperature sensor 61 is formed in the vicinity of the exhaust heat recovery device outlet channel 11b, it can accurately respond to the heat of the heat medium after heat exchange. For this reason, since a heat medium can be controlled to suitable temperature, it can suppress that a heat medium becomes too hot and boils.

  The temperature sensor 61 only needs to be able to measure the temperature of the bottom of the recess 101a of the outer wall 101 to which the heat of the heat medium is transmitted, and may be installed apart from the recess 101a. For example, a radiation thermometer is used for the temperature sensor 61 installed away from the recess 101a.

(Second Embodiment)
With reference to FIG. 4, the exhaust heat recovery device 100 of 2nd Embodiment of this invention is demonstrated.

  In the exhaust heat recovery device 100 according to the second embodiment, the configurations of the heat exchange unit 10 and the valve switching mechanism 60 are different from those of the first embodiment. In the following embodiments, the same functions as those in the first embodiment are denoted by the same reference numerals, and repeated description will be omitted as appropriate.

  In the exhaust heat recovery device 100 according to the second embodiment, as shown in FIG. 4, the actuator 62 of the valve switching mechanism 60 is directly attached to the outer wall portion 101 located outside the heat exchange unit 10 in the exhaust heat recovery device 100. It has been. A heat medium passage 11 through which a heat medium flows is formed inside the outer wall portion 101.

  Here, the structure of the valve switching mechanism 60 will be described with reference to FIGS. 5A and 5B. FIG. 5A is a structural diagram when the inside of the actuator 62 is viewed from the side. FIG. 5B is a cross-sectional view taken along line Vb-Vb in FIG. 5A. 5A shows a cross section taken along the line Va-Va in FIG. 5B.

  5A and 5B, the valve switching mechanism 60 includes an actuator 62 that rotates the valve 50, a grease 64 that transmits heat of the heat medium to the actuator 62, and a case 65 that encloses the grease 64 inside. .

  The actuator 62 is attached to the outer wall 101 of the exhaust heat recovery device 100 located outside the heat exchange unit 10. The actuator 62 includes an element 62a, a rod 62d, a non-linear spring 62e, a thermal expansion body 62b, and a piston 62c. One end of the actuator 62 is connected to the valve 50.

  The element 62 a is formed on the other end side of the actuator 62, that is, on the side opposite to the valve 50. A piston 62c is inserted into the element 62a so as to be able to advance and retract. The element 62a is filled with a thermal expansion body 62b so as to fill a space other than the piston 62c.

  The thermal expansion body 62b is solid when the temperature is low, and a material that melts and expands when the temperature becomes high is used. The thermal expansion body 62 b functions as a thermal response unit that expands and contracts by the heat of the heat medium transmitted through the element 62 a of the actuator 62.

  The piston 62c advances and retreats due to the expansion and contraction of the thermal expansion body 62b. The piston 62c is pushed out from the initial position in the element 62a by the expansion of the thermal expansion body 62b, and moves forward in the valve 50 direction. A rod 62d is disposed in contact with the end of the piston 62c on the valve 50 side.

  The rod 62d advances in the direction of the valve 50 by pushing one end of the rod 62d toward the piston 62c. The other end of the rod 62d is connected to the valve 50, and the valve 50 is rotated by advancing and retreating. A nonlinear spring 62e is attached to the rod 62d. In this manner, the rod 62d functions as an operating unit that rotates the valve 50.

  The nonlinear spring 62e biases the rod 62d toward the piston 62c. Therefore, since the piston 62c is biased by the nonlinear spring 62e via the rod 62d, it can return to the initial position in the element 62a when the thermal expansion body 62b contracts.

  A grease 64 is disposed outside the element 62a so that heat exchange with the element 62a can be performed. As the grease 64, a material having high heat conductivity and high heat resistance capable of exhibiting stable performance even in an environment of 150 ° C. to 200 ° C. is used. For example, a copper mesh may be used as a member having high thermal conductivity and high heat resistance.

  The case 65 is formed of a heat insulating material and is formed around the element 62a. A space is formed between the case 65 and the element 62a. For the case 65, a heat insulating structure is used, for example, one having a double tube structure inside. The case 65 has a flange 65 a at a portion that comes into contact with the outer wall portion 101. The flange 65a of the case 65 is joined and fixed to the outer wall 101 by welding or caulking. When the flange 65a is joined and fixed to the outer wall portion 101, the case 65 is sealed, and the grease 64 and the element 62a are enclosed in a sealed space in the case 65.

  Thus, between the thermal expansion body 62b and the heat medium of the heat medium flow path 11, the outer wall portion 101, the grease 64, and the element 62a having good heat transfer properties are disposed. Accordingly, the thermal expansion body 62b expands and contracts in response to the heat of the heat medium transmitted through the outer wall portion 101, the grease 64, and the element 62a. A dimple 101b is provided on the outer wall portion 101 in contact with the grease 64 so as to increase the heat transfer efficiency by locally accelerating the flow of the heat medium in the heat medium flow path 11.

  When the temperature of the heat medium in the heat medium flow path 11 is low, the thermal expansion body 62b in the element 62a is fixed, and the rod 62d is biased by the nonlinear spring 62e, so that the piston 62c is in the initial position. Retained. When the temperature of the heat medium is low, for example, the engine is not warmed up and the temperature of the exhaust gas is low. When the piston 62c is held at the initial position, the valve 50 abuts against the stopper 51 and closes the bypass portion 20 as shown in FIG. 2A. For this reason, the exhaust gas introduced into the exhaust gas introduction unit 30 flows to the heat exchange unit 10.

  When the temperature of the exhaust gas becomes higher and the temperature of the heat medium in the heat medium flow path 11 becomes higher, the heat expansion body 62b in the element 62a is melted and expanded by the heat of the transmitted heat medium, and pushes out the piston 62c. The rod 62d moves forward against the reaction force of the nonlinear spring 62e. The valve 50 rotates to a position where it comes into contact with the stopper 52 as shown in FIG. 2B. For this reason, the exhaust gas introduced into the exhaust gas introduction unit 30 flows to the bypass unit 20. As described above, since the exhaust gas flows into the bypass unit 20, heat exchange between the heat medium and the exhaust gas is not performed in the heat exchanging unit 10, so that the temperature of the heat medium can be suppressed from becoming too high.

  Thereafter, when the temperature of the heat medium is lowered and the thermal expansion body 62b is solidified and contracted, the rod 62d is retracted by the reaction force of the nonlinear spring 62e, and the piston 62c is returned to the initial position. As a result, as shown in FIG. 2A, the valve 50 rotates again to a position where it comes into contact with the stopper 51, so that the flow path to the bypass unit 20 is closed and the exhaust gas flows to the heat exchange unit 10.

  According to the exhaust heat recovery device 100 according to the second embodiment described above, the following effects can be obtained.

  In the exhaust heat recovery device 100 according to the present embodiment, the valve switching mechanism 60 includes an actuator 62. The actuator 62 includes a thermal expansion body 62b that functions as a thermal response unit by performing expansion and contraction by the heat of the heat medium, and a rod 62d that functions as an operation unit by moving forward and backward by the expansion and contraction of the thermal expansion body 62b. . The actuator 62 includes an element 62a that is filled with a thermal expansion body 62b and a rod 62d and that transmits heat of the heat medium to the thermal expansion body 62b.

  With such a configuration, the thermal expansion body 62b expands and contracts due to the heat of the heat medium and moves the rod 62d forward and backward, so that the valve switching mechanism 60 rotates the valve 50 accurately according to the heat of the heat medium. can do.

  In the exhaust heat recovery device 100 according to the present embodiment, the valve switching mechanism 60 includes a grease 64 that is disposed outside the element 62a and serves as a heat transfer body that transfers the heat of the heat medium. The grease 64 transfers the heat of the heat medium to the thermal expansion body 62b via the element 62a.

  With such a configuration, the thermal expansion body 62b can be expanded and contracted by the heat of the heat medium transmitted through the grease 64 without providing the element 62a in the heat medium flow path 11. . For this reason, it is not necessary to use a seal that may be deteriorated or broken due to heat damage at the contact portion between the element 62a and the heat medium flow path 11, and the heat medium can be prevented from leaking to the outside.

  The exhaust heat recovery device 100 according to the present embodiment includes a case 65 having a heat insulating structure that forms a sealed space with the exhaust heat recovery device 100. The grease 64 and the element 62a as a heat transfer body are enclosed in a sealed space between the exhaust heat recovery device 100 and the case 65.

  By adopting such a configuration, the thermal expansion body 62b is thermally insulated from the surroundings by the case 65 having a heat insulating structure, so that the actuator 62 can be prevented from malfunctioning due to the thermal influence around the exhaust heat recovery device 100. Further, since the grease 64 and the element 62a enclosed in the sealed space transmit the heat of the heat medium in the heat medium flow path 11 to the thermal expansion body 62b via the outer wall portion 101 of the exhaust heat recovery device 100, the thermal expansion body Heat exchange can be accurately performed between 62b and the heat medium.

  In the exhaust heat recovery device 100 according to the present embodiment, the case 65 is joined to the actuator 62 and the exhaust heat recovery device 100.

  With this configuration, the case 65 can be installed on the outer wall 101 of the actuator 62 and the exhaust heat recovery device 100 without using additional components such as a shielding plate. The score can be reduced. Moreover, since the case 65 is fixed by joining, it is possible to eliminate the concern of deterioration or damage due to heat damage.

  In the present embodiment, the heat medium flow path 11 through which the heat medium flows is formed inside the outer wall portion 101. However, for example, even if the exhaust passage 12 through which exhaust gas flows is formed inside the outer wall portion 101, Good. In this case, the thermal expansion body 62b in the element 62a expands and contracts by the heat of the exhaust gas flowing through the exhaust passage 12, whereby the rod 62d advances and retreats, and the valve 50 can be rotated.

  6A and 6B, a protrusion plate 62f may be provided on the outer periphery of the element 62a so as to increase the contact area with the grease 64 so that heat from the grease 64 is easily transmitted. By doing in this way, the heat of the heat medium which flows through the heat medium flow path 11 can be more efficiently transmitted to the thermal expansion body 62b.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  In the above embodiment, the heat of the heat medium flowing through the heat medium flow path 11 is transmitted via the outer wall portion 101 positioned outside the heat exchange unit 10, but the heat of the heat medium is also transmitted by other methods. be able to. For example, a through passage that penetrates to the inside of the heat exchanging portion 10 is formed independently so as not to directly contact the heat medium in the heat medium passage 11, and heat of the heat medium is transmitted from the heat medium passage 11 in the vicinity of the through passage. Can be made. Further, a part of the heat medium flow path 11 in the vicinity of the exhaust heat recovery device outlet flow path 11b may be wound around the temperature sensor 61 or the element 62a to transmit the heat of the heat medium.

DESCRIPTION OF SYMBOLS 100 Waste heat recovery device 10 Heat exchange part 11 Heat medium flow path 11b Waste heat recovery device exit flow path 20 Bypass part 30 Exhaust introduction part 50 Valve 60 Valve switching mechanism 61 Temperature sensor 62 Actuator 62a Element 62b Thermal expansion body 62c Piston 62d Rod 62e Non-linear spring 64 Grease 65 Case 70 Controller 101 Outer wall portion 101a Recessed portion

Claims (8)

A heat exchanging section for exchanging heat with the exhaust discharged from the engine;
A bypass section for bypassing exhaust gas from the heat exchange section;
A valve that distributes exhaust gas to the heat exchange section and the bypass section;
A valve switching mechanism for rotating the valve;
With
The heat exchange unit includes a heat medium flow path through which a heat medium for exchanging heat with the exhaust gas circulates,
The valve switching mechanism is
A thermal response portion that is disposed apart from the heat medium and responds by heat of the heat medium;
An operating part for rotating the valve in response to the thermal response part;
An exhaust heat recovery device comprising: The exhaust heat recovery device according to claim 1,
An outer wall formed on the outer periphery of the heat exchange unit;
The thermal response part of the valve switching mechanism is installed in contact with the outer wall part,
An exhaust heat recovery device characterized by that. The exhaust heat recovery device according to claim 2,
The heat exchange part includes an exhaust passage between the outer wall part and the heat medium flow path,
The outer wall is formed with a recess that is recessed toward the exhaust passage and contacts the heat medium flow path.
In the recess, the thermal response unit is installed with a predetermined gap from an end of the recess.
An exhaust heat recovery device characterized by that. The exhaust heat recovery device according to claim 3,
In the heat medium flow path, an exhaust heat recovery device outlet flow channel for allowing the heat medium circulated in the exhaust heat recovery device to flow out is formed so as to penetrate the exhaust passage,
The recess is formed in the vicinity of the exhaust heat recovery device outlet channel,
The concave portion and the exhaust heat recovery device outlet flow path are arranged so as to be aligned in a direction in which the exhaust gas flows in the exhaust passage.
An exhaust heat recovery device characterized by that. The exhaust heat recovery device according to any one of claims 1 to 4,
The valve switching mechanism includes an actuator.
A thermal expansion body that functions as the thermal response unit by performing expansion and contraction by the heat of the heat medium;
A rod that functions as the operating part by advancing and retracting due to expansion and contraction of the thermal expansion body;
An element filled therein with the thermal expansion body and the rod, and transmitting heat of the heat medium to the thermal expansion body;
Comprising
An exhaust heat recovery device characterized by that. The exhaust heat recovery device according to claim 5,
The valve switching mechanism is disposed outside the element and includes a heat transfer body that transfers heat of the heat medium,
The heat transfer body transfers heat of the heat medium to the thermal expansion body through the element.
An exhaust heat recovery device characterized by that. The exhaust heat recovery device according to claim 6,
A case with a heat insulating structure that forms a sealed space with the exhaust heat recovery device,
The heat transfer body and the element are enclosed in the sealed space between the exhaust heat recovery device and the case.
An exhaust heat recovery device characterized by that. The exhaust heat recovery device according to claim 7,
The case is joined to the actuator and the exhaust heat recovery unit,
An exhaust heat recovery device characterized by that.

Images