Exhaust heat recovery device

Abstract

This exhaust heat recovery device (1) comprises: a first flow path member (10) that has a first flow path through which exhaust gas flows; a second flow path member (20) that is adjacent to the first flow path member (10), has a heat exchange unit (30), and has a second flow path; and a valve mechanism (40) that opens / closes the first flow path and blocks or inhibits the flow of exhaust gas from the second flow path. The valve mechanism (40) comprises: a valve body (43) that closes the first flow path in a heat recovery state in which the first flow path is closed; and a shutter unit (42) that blocks or inhibits the flow of exhaust gas from the second flow path in a heat non-recovery state in which the first flow path is opened. The first flow path member (10) has a first upright section (17) that rises up toward the inside of the first flow path. An end section (43a) of the valve body (43) abuts or is close to the first upright section (17) in the heat recovery state of the valve body (43).

Description

Exhaust heat recovery device

[0001] The present invention relates to an exhaust heat recovery device.

[0002] JP2021-188567A discloses an exhaust heat recovery device having a first flow path member having a first flow path through which exhaust gas flows, a second flow path member provided adjacent to the first flow path and having a second flow path that bypasses the first flow path, and a heat exchange unit that exchanges heat between the exhaust gas and a refrigerant.

[0003] The exhaust heat recovery device described in JP2021-188567A has a butterfly valve that opens and closes the first flow path using a rotating shaft that is perpendicular to the flow direction of the exhaust gas in the first flow path, and a shutter unit that blocks the outlet from the second flow path, which is a bypass path, when the butterfly valve opens the first flow path, and opens the outlet when the butterfly valve blocks the first flow path, and is equipped with a valve mechanism that switches the flow path of the exhaust gas to the first flow path or the second flow path.

[0004] In the exhaust heat recovery device disclosed in JP2021-188567A, it is assumed that the outer peripheral wall of the cylindrical shutter portion will come into surface contact with the inner wall of the first flow path member to block the outlet, but to achieve this, it is necessary to precisely match the dimensions of the two. In other words, if the cylindrical shape of the shutter portion is formed relatively larger than the inner wall (inner periphery) of the first flow path member due to the tolerance between the two, the tip of the shutter portion will come into corner contact with the inner wall of the first flow path member.

[0005] According to one aspect of the present invention, there is provided an exhaust heat recovery device that recovers heat from exhaust gas emitted from an engine by heat exchange with a fluid, the device comprising: a first flow path member having a first flow path formed therein through which exhaust gas flows; a second flow path member provided adjacent to the first flow path member, having a second flow path formed therein that bypasses a part of the first flow path and having a heat exchange portion that exchanges heat between the exhaust gas flowing in the second flow path and the fluid; and a valve mechanism provided in the first flow path, wherein the first flow path member has an outlet for exhaust gas from the first flow path to the second flow path, an inlet for exhaust gas from the second flow path to the first flow path, and a first upright portion that is located upstream of the inlet in the first flow path, extends in a direction perpendicular to the flow direction of the exhaust gas, and uprights toward the inside of the first flow path; and the valve mechanism has a rotary shaft portion and a rotary shaft portion. An exhaust heat recovery device is provided, comprising: a valve body that rotates with rotation and closes or opens the first flow path; and a shutter portion that rotates with rotation of the rotating shaft portion and closes or obstructs the flow of exhaust gas from the inlet, wherein in a heat recovery state, the valve body of the valve mechanism closes the first flow path and the shutter portion opens the flow of exhaust gas from the inlet, and in a heat non-recovery state, the valve body of the valve mechanism opens the first flow path and the shutter portion closes or obstructs the flow of exhaust gas from the inlet, and in the heat non-recovery state, a gap is formed in the direction separating the inlet and the shutter portion, and in the height direction from the outside to the inside of the first flow path, the first upright portion is formed larger than the gap, and the tip of the shutter portion abuts or is close to the first upright portion in the heat non-recovery state.

[0006] According to the exhaust heat recovery device of the present invention, in the heat recovery state, it is possible to sufficiently achieve blocking of the inlet or obstruction of gas flow while preventing corner contact between the tip of the shutter portion and the inner wall of the first flow path member.

[0007] FIG. 1 is a perspective view illustrating an exhaust heat recovery device according to a first embodiment of the present invention. FIG. 2 is a front view showing a portion of the exhaust heat recovery device according to the first embodiment, with a cutaway portion. FIG. 3 is a side view seen from the upstream side of the first flow path, illustrating the heat recovery state of the exhaust heat recovery device according to the first embodiment. FIG. 4 is a perspective view showing a valve mechanism of the exhaust heat recovery device according to the first embodiment. FIG. 5 is a front view showing a portion of the exhaust heat recovery device according to the first embodiment, with a cutaway portion. FIG. 6 is a side view seen from the upstream side of the first flow path, illustrating the heat non-recovery state of the exhaust heat recovery device according to the first embodiment. FIG. 7 is a front view showing a portion of the exhaust heat recovery device according to a second embodiment. FIG. 8 is a front view showing a portion of the exhaust heat recovery device 2 according to the second embodiment, with a cutaway portion.

[0008] First Embodiment An exhaust heat recovery device 1 according to a first embodiment of the present invention will be described below with reference to the drawings.

[0009] Fig. 1 is a perspective view illustrating an exhaust heat recovery system 1 according to a first embodiment of the present invention. Fig. 2 is a front view showing a portion of the exhaust heat recovery system 1 in a cutaway state. Fig. 3 is a side view showing the heat recovery state of the exhaust heat recovery system 1 shown in Fig. 2 as viewed from the upstream side of a first flow path 14.

[0010] As shown in FIG. 1 , the exhaust heat recovery device 1 includes a first flow path member 10 , a second flow path member 20 , and a heat exchange section 30 .

[0011] The first flow path member 10 has a main body 11, a first inlet 12, and a first outlet 13. The main body 11 has a hollow structure, and a first flow path 14 through which exhaust gas flows is formed inside the main body 11.

[0012] The first inlet portion 12 is an opening on one side of the main body portion 11 and is connected to the flow path of exhaust gas from the engine. The first outlet portion 13 is an opening on the other side of the main body portion 11 and is connected to the flow path of exhaust gas. The first inlet portion 12 is located upstream of the first outlet portion 13 in the exhaust gas flow.

[0013] The main body 11 is formed with a first upstream opening 15 as an outlet through which exhaust gas flows from the first flow path 14 to the second flow path 24 (see Figure 2), and a first downstream opening 16 as an inlet through which exhaust gas flows from the second flow path 24 to the first flow path 14.

[0014] The second flow path member 20 is provided adjacent to the first flow path member 10. The second flow path member 20 has a main body portion 21, a second upstream opening 22, and a second downstream opening 23.

[0015] The main body 21 has a hollow structure, and a second flow path 24 is formed inside the main body 21, through which exhaust gas that has bypassed a part of the first flow path 14 flows.

[0016] The second upstream opening 22 is located upstream of the second flow path 24, and takes in the exhaust gas that has bypassed a part of the first flow path 14 into the inside of the main body 21. The second downstream opening 23 allows the exhaust gas that has flowed inside the main body 21 to flow into the first flow path 14.

[0017] The second upstream opening 22 is connected to the first upstream opening 15 formed in the first flow path member 10 by a first communication portion 25. The second downstream opening 23 is connected to the first downstream opening 16 formed in the first flow path member 10 by a second communication portion 26.

[0018] The inside of the first communication portion 25 , the interior of the second flow path member 20 , and the inside of the second communication portion 26 form a second flow path 24 .

[0019] The above-described first flow path member 10 and second flow path member 20 allow exhaust gas to be diverted from the first flow path 14 to the second flow path member 20 through the first communicating portion 25. In addition, the exhaust gas that has flowed through the second flow path member 20 can be made to flow into the first flow path 14 through the second communicating portion 26.

[0020] The second flow path member 20 has a heat exchanger 30. The heat exchanger 30 has a refrigerant inlet 31, a heat exchanger main body 32, and a refrigerant outlet 33, and coolant flows through the heat exchanger 30 as a refrigerant. The heat exchanger 30 exchanges heat between the exhaust gas flowing through the second flow path 24 and the refrigerant.

[0021] The refrigerant inlet 31 is a hollow pipe-shaped section that connects a flow path (not shown) through which coolant flows before cooling the engine and the inside of the heat exchanger main body 32. The refrigerant inlet 31 allows the coolant supplied from the flow path to flow into the heat exchanger main body 32.

[0022] The refrigerant outlet 33 is a hollow tube-shaped section that connects the inside of the heat exchanger main body 32 to a flow path (not shown) that supplies cooling water to the engine. The refrigerant inlet 31 allows the cooling water that has flowed inside the heat exchanger main body 32 to flow out into the flow path.

[0023] When exhaust gas flows through the portion of the main body 21 of the second flow path member 20 surrounded by the heat exchanger main body 32 (the portion of the second flow path 24 surrounded by the heat exchanger main body 32), the heat exchanger 30 performs heat exchange between the exhaust gas and the cooling water flowing inside the heat exchanger main body 32, and transfers and recovers heat from the exhaust gas to the cooling water. Note that a state in which the valve mechanism 40 described below closes the first flow path 14 and the exhaust gas flows through the second flow path 24 to perform the heat exchange is called a heat recovery state. On the other hand, a state in which the valve mechanism 40 opens the first flow path 14 and the exhaust gas does not flow through the second flow path 24 is called a heat non-recovery state.

[0024] In the first embodiment, the first flow path member 10 has a first upright portion 17 that stands toward the inside of the first flow path 14. The first upright portion 17 is located upstream of the first downstream opening 16 in the first flow path 14. It can also be said that the first upright portion 17 is disposed between the first upstream opening 15 and the first downstream opening 16 on the inner surface of the first flow path member 10. Furthermore, the first upright portion 17 is formed across the first downstream opening 16 in a direction perpendicular to the flow direction of exhaust gas.

[0025] The first flow path member 10 has, on its inner surface, a second upright portion 18 that stands toward the inside of the first flow path 14. The second upright portion 18 is disposed on the inner surface of the first flow path member 10, on the side opposite to the side on which the first upright portion 17 is formed. In the heat recovery state, the second upright portion 18 is located upstream of the valve body 43 ( FIG. 4 ) of the valve mechanism 40. The second upright portion 18 is formed in a direction perpendicular to the flow direction of the exhaust gas.

[0026] In this embodiment, the first upright portion 17 is formed so that its height h1 from the inner surface of the first flow path member 10 is larger than the gap d1 formed in the separation direction between the first downstream opening 16 and the valve mechanism 40 (shutter portion 42) in the heat non-recovery state (FIG. 5). Furthermore, the second upright portion 18 is formed so that its height h2 from the inner surface of the first flow path member 10 is larger than the gap d2 in the separation direction between the inner surface of the first flow path member 10 and the valve mechanism 40 (valve body 43) in the heat recovery state (FIG. 2).

[0027] As shown in FIG. 2 , the exhaust heat recovery device 1 includes a valve mechanism 40 inside the first flow path member 10 .

[0028] FIG. 4 is a perspective view illustrating the valve mechanism 40 of the exhaust heat recovery system 1 shown in FIG.

[0029] The valve mechanism 40 has a butterfly valve 41 that opens and closes the first flow path 14, a shutter portion 42 that blocks or obstructs exhaust gas flowing from the second flow path 24 into the first flow path 14, and a valve body 43 that opens and closes the first flow path 14.

[0030] A rotary shaft 44 is connected to the valve body 43 and is rotatably supported within the first flow path 14. The rotary shaft 44 is connected to a drive shaft of an actuator (not shown) as a drive unit.

[0031] The valve element 43 of the butterfly valve 41 is a plate-shaped member formed to a length and width sufficient to close the first flow path 14. The valve element 43 can switch between opening and closing the first flow path 14 by rotating the rotary shaft portion 44.

[0032] The shutter 42 is provided on the valve body 43. The shutter 42 has a plate-shaped shutter main body 42a and a pair of connecting portions 42b. The shutter main body 42a closes the first downstream opening 16 in the heat non-recovery state and opens the first downstream opening 16 in the heat non-recovery state.

[0033] The connecting portion 42b supports the shutter main body portion 42a by maintaining a distance from the valve body 43 that prevents the shutter main body portion 42a from contacting the inner wall portion (first downstream opening 16) of the first flow path member 10 and is capable of blocking the first downstream opening 16.

[0034] The shutter portion 42 has a protrusion 45 that protrudes outward in the direction of the radius of rotation of the rotating valve mechanism 40. The surface of the protrusion 45 is formed in a curved shape, and in the non-heat recovery state (FIGS. 5 and 6), the protrusion 45 abuts against or is close to the inner surface of the first flow path member 10 downstream of the first downstream opening 16 in the flow direction of the exhaust gas.

[0035] In the heat non-recovery state, the tip 42 e (end face) of the shutter portion 42 on the upstream side in the flow direction of the exhaust gas is configured to abut or come close to the first upright portion 17 .

[0036] <Operation of Valve Mechanism and Flow of Exhaust Gas> Next, the operation of the valve mechanism 40 and the flow of exhaust gas in the exhaust heat recovery system 1 according to the first embodiment will be described.

[0037] Fig. 5 is a partially cutaway front view of the exhaust heat recovery device 1. Fig. 6 is a side view of the exhaust heat recovery device 1 shown in Fig. 5 in a non-heat recovery state, as viewed from the upstream side of the first flow path 14.

[0038] The valve mechanism 40 in the exhaust heat recovery device 1 can be switched between a heat recovery state (Figures 2 and 3) in which the first downstream opening 16 is opened by the shutter portion 42 and the first flow path 14 is closed by the butterfly valve 41, and a non-heat recovery state (Figures 5 and 6) in which the first downstream opening 16 is closed by the shutter portion 42 and the first flow path 14 is opened by the butterfly valve 41.

[0039] 5 and 6 , in the first embodiment, when the valve mechanism 40 rotates so that the main surface of the valve element 43 of the valve mechanism 40 is parallel to the flow direction of exhaust gas (see the arrow in FIG. 5 ) and the heat non-recovery state is entered, the tip 42 e of the shutter portion 42 abuts against the surface of the first upright portion 17 on the downstream side in the exhaust gas flow direction, and the convex portion 45 formed on the shutter portion 42 abuts against the inner surface of the first flow path member 10 downstream of the first downstream opening 16 in the exhaust gas flow direction. Note that in the heat non-recovery state, the tip 42 e may abut against the first upright portion 17, and the convex portion 45 may be close to the inner surface of the first flow path member 10. Alternatively, in the heat non-recovery state, the tip 42 e may be close to the first upright portion 17, and the convex portion 45 may abut against the inner surface of the first flow path member 10. In the heat non-recovery state, the tip 42e may abut against the first upright portion 17, and the protrusion 45 may also abut against the inner surface of the first flow path member 10. "Close" here refers to a state in which they face each other with a slight gap therebetween.

[0040] In this state, the exhaust gas flows into the first flow path member 10 from the first inlet portion 12 , flows through the first flow path 14 formed inside the first flow path member 10 , and flows out from the first outlet portion 13 .

[0041] On the other hand, the end 43a of the valve element 43, which was located upstream in the flow direction in the heat non-recovery state, approaches the first upright portion 17, and the end 43b of the valve element 43, which was located downstream in the flow direction, rotates in a direction approaching the second upright portion 18, causing the valve mechanism 40 to rotate so that the main surface of the valve element 43 of the valve mechanism 40 is perpendicular to the flow direction of the exhaust gas, thereby transitioning to the heat recovery state. The second upright portion 18 will be described later.

[0042] 2 and 3, in the heat recovery state, the upstream surface of the first upright portion 17 in the flow direction comes into contact with the downstream surface of the end 43a of the valve body 43. Also, the downstream surface of the second upright portion 18 in the flow direction comes into contact with the upstream surface of the end 43b of the valve body 43 in the flow direction.

[0043] In this state, when exhaust gas flows into the first flow path member 10 from the first inlet portion 12, it remains in the space S formed by the valve body 43 and the first flow path member 10, and then flows into the second flow path 24 from the first upstream opening 15 (see the arrow in Figure 2).

[0044] In the heat recovery state, the upstream surface of the first standing portion 17 may be configured to abut against the downstream surface of the end 43a of the valve body 43, or the downstream surface of the second standing portion 18 may be configured to abut against the upstream surface of the end 43b of the valve body 43.

[0045] The exhaust gas flows through the second flow path 24 inside the second flow path member 20, and exchanges heat with the refrigerant flowing through the heat exchange section 30. After flowing through the second flow path 24, the exhaust gas returns to the first flow path 14 from the first downstream opening 16, flows through the first flow path, and flows out from the first outlet section 13.

[0046] <Action and effect> The exhaust heat recovery device 1 according to the first embodiment comprises: a first flow path member 10 having a first flow path 14 formed therein through which exhaust gas flows; a second flow path member 20 provided adjacent to the first flow path member 10 and having a second flow path 24 formed therein that bypasses part of the first flow path 14 and having a heat exchange section 30 that exchanges heat between the exhaust gas flowing through the second flow path 24 and the refrigerant; and a valve mechanism 40 disposed within the first flow path member 10 and having a butterfly valve 41 that opens and closes the first flow path 14 and a shutter section 42 that blocks or obstructs the flow of exhaust gas from the second flow path 24.

[0047] The first flow path member 10 is formed with a first upstream opening 15 as an outlet for exhaust gas from the first flow path 14 to the second flow path 24, and a first downstream opening 16 as an inlet for exhaust gas from the second flow path 24 to the first flow path 14.

[0048] The valve mechanism 40 is configured to be switched between a heat recovery state and a heat non-recovery state by rotation of a rotary shaft 44 that is perpendicular to the flow direction of exhaust gas in the first flow path 14. As described above, in the heat non-recovery state, the shutter 42 closes the first downstream opening 16, and the butterfly valve 41 opens the first flow path 14. In the heat recovery state, the shutter 42 opens the first downstream opening 16, and the butterfly valve 41 closes the first flow path 14.

[0049] The first flow path member 10 has a first upstanding portion 17 that stands toward the inside of the first flow path 14 in a direction perpendicular to the flow direction of the exhaust gas (from the outside to the inside of the first flow path 14). The first upstanding portion 17 is located upstream of the first downstream opening 16 in the first flow path 14. In addition, in the direction from the outside to the inside of the first flow path 14, the first upstanding portion 17 is formed to be larger than the gap d1 that occurs in the direction separating the first downstream opening 16 and the shutter portion 42 that closes the first downstream opening 16 in the heat non-recovery state.

[0050] Therefore, in the non-heat recovery state, the first upright portion 17 can block the gap d1 that forms in the direction of separation between the first downstream opening 16 and the shutter portion 42. Here, when exhaust gas flows through the first flow path 14, that flow makes it easier for the first downstream opening 16 to draw in exhaust gas from the second flow path 24. However, in the exhaust heat recovery device 1, despite the presence of a gap between the shutter portion 42 and the first downstream opening 16, the formation of the first upright portion 17 suppresses such exhaust gas drawing. This makes it possible to prevent exhaust gas from flowing into the second flow path 24 at the first upstream opening 15.

[0051] Therefore, when heat recovery from the exhaust gas is not required, the inflow of the exhaust gas into the heat exchange section 30 can be suppressed, and a decrease in exhaust efficiency can be prevented.

[0052] In a conventional exhaust heat recovery device, the main surface of the cylindrical shutter is in surface contact with the inner wall of the first flow path member to open the first flow path and close the second flow path. However, with this structure, if there is a difference in the dimensions of the shutter and the inner wall (inner periphery) of the first flow path member, a corner collision may occur, in which a part of the shutter interferes with the inner wall of the first flow path member.

[0053] On the other hand, the exhaust heat recovery device 1 includes the first upright portion 17 and forms the above-described gap d1, so that the valve mechanism 40 and the first flow path member 10 do not come into contact with each other due to the rotation of the valve mechanism 40, even if the relative sizes and positions of the valve mechanism 40 and the first flow path member 10 are not strictly designed. The exhaust heat recovery device 1 can prevent corner contact, in which a part of the shutter portion interferes with the inner wall of the first flow path member. Furthermore, the exhaust heat recovery device 1 can sufficiently block or obstruct the gas flow from the second flow path 24 at the first downstream opening 16 when the valve mechanism 40 is in a non-heat recovery state.

[0054] The first flow path member 10 has, on its inner surface opposite the first upright portion 17, a second upright portion 18 that stands toward the inside of the first flow path 14 in a direction perpendicular to the flow direction of the exhaust gas.

[0055] The second raised portion 18 is larger than the gap d2 in the direction of separation between the inner surface of the first flow path member 10 and the butterfly valve 41 when the valve mechanism 40 is in the heat recovery state, and is formed downstream of the butterfly valve 41 when the valve mechanism 40 is in the heat recovery state.

[0056] When the valve mechanism 40 is in the heat recovery state, the second upright portion 18 can shield the gap d2 in the separation direction between the inner surface of the first flow path member 10 and the butterfly valve 41 from the downstream side.

[0057] This makes it possible to prevent exhaust gas from flowing into the first flow path 14 in the heat recovery state in which the shutter portion 42 opens the first downstream opening 16 and the butterfly valve 41 closes the first flow path 14.

[0058] Therefore, the exhaust heat recovery device 1 can suppress leakage of exhaust gas into the first flow passage 14 when heat recovery from exhaust gas is required, and can prevent a decrease in heat recovery efficiency.

[0059] In the heat recovery state of the exhaust heat recovery device 1 according to the first embodiment, the downstream surface in the flow direction at the end of the valve body 43 of the valve mechanism 40 abuts against the upstream surface in the flow direction of the first upright portion 17. Furthermore, the upstream surface in the flow direction at the end of the valve body 43 abuts against the downstream surface in the flow direction of the second upright portion 18.

[0060] As a result, the first upright portion 17 and the second upright portion 18 contribute to positioning the butterfly valve 41 when the valve mechanism 40 is in the heat recovery state.

[0061] Therefore, when heat recovery from exhaust gas is required, leakage of exhaust gas into the first flow passage 14 is suppressed, and the effect of preventing a decrease in heat recovery efficiency is enhanced.

[0062] Furthermore, if the valve mechanism 40 is configured to abut either the first upright portion 17 or the second upright portion 18, the positioning effect of the butterfly valve 41 can be obtained when the valve mechanism 40 is in the heat recovery state.

[0063] The shutter portion 42 has a protrusion 45 that protrudes outward in the direction of the radius of rotation of the rotating valve mechanism 40. When the valve mechanism 40 is in a heat non-recovery state, the protrusion 45 abuts against the inner surface of the first flow path member 10 downstream of the first downstream opening 16 in the flow direction of the exhaust gas.

[0064] The end of the valve mechanism 40 on the upstream side in the exhaust gas flow direction is prone to come into contact with the inner surface of the first flow path member 10 because it precedes the valve mechanism 40 in rotating. In contrast, according to the exhaust heat recovery device 1, the shutter portion 42 has a convex portion 45. Therefore, even if the gap between the end of the valve mechanism 40 on the upstream side in the exhaust gas flow direction and the inner surface of the first flow path member 10 is designed with enough margin to prevent contact, the end of the valve mechanism 40 on the downstream side in the exhaust gas flow direction abuts against the convex portion 45. This positions the shutter portion 42 when the valve mechanism 40 is in a non-heat recovery state. Note that the convex portion 45 comes into contact with the inner surface of the first flow path member 10 from an obtuse angle, and the surface of the convex portion 45 is curved, so that galling (digging into the inner surface) is unlikely to occur.

[0065] Second Embodiment Next, an exhaust heat recovery device 2 according to a second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, components having the same functions as those in the first embodiment are assigned the same reference numerals, and detailed descriptions thereof will be omitted.

[0066] 7 and 8 are partially cutaway front views of the exhaust heat recovery device 2 according to the second embodiment. Fig. 7 illustrates the valve mechanism 40 in the exhaust heat recovery device 2 in a heat recovery state, and Fig. 8 illustrates the valve mechanism 40 in a non-heat recovery state.

[0067] In the second embodiment, the first upright portion 17 and the second upright portion 18 in the first embodiment are formed at the downstream end of the inner member 70 in the flow direction of exhaust gas.

[0068] That is, the exhaust heat recovery device 2 includes an inner member 50 inside the first flow path member 10, the inner member 50 covering at least a part of the inner surface of the first flow path member 10. The inner member 50 is integrally formed with a first upright portion 51 and a second upright portion 52 that are folded back toward the inside of the first flow path 14.

[0069] In the second embodiment, the first upright portion 51 is formed so that its height H1 from the inner surface of the first flow path member 10 is larger than the gap D1 formed in the separation direction between the first downstream opening 16 and the valve mechanism 40 (shutter portion 42) when the valve mechanism 40 is in the heat non-recovery state ( FIG. 8 ). Furthermore, the second upright portion 52 is formed so that its height H2 from the inner surface of the first flow path member 10 is larger than the gap D2 in the separation direction between the inner surface of the first flow path member 10 and the valve mechanism 40 (valve body 43) when the valve mechanism 40 is in the heat recovery state ( FIG. 7 ).

[0070] In the exhaust heat recovery device 2, when the valve mechanism 40 is in the heat recovery state, the upstream surface of the first upright portion 51 in the flow direction comes into contact with the downstream surface of the end 43a of the valve body 43. Also, the downstream surface of the second upright portion 52 in the flow direction comes into contact with the upstream surface of the end 43b of the valve body 43 in the flow direction.

[0071] As a result, the first upright portion 51 and the second upright portion 52 contribute to positioning the butterfly valve 41 when the valve mechanism 40 is in the heat recovery state.

[0072] Therefore, the exhaust heat recovery device 2 suppresses leakage of exhaust gas into the first flow passage 14 when heat recovery from exhaust gas is required, and the effect of preventing a decrease in heat recovery efficiency is enhanced.

[0073] Furthermore, in the exhaust heat recovery device 2 according to the second embodiment, exhaust gas comes into contact with the inner member 50 provided inside the first flow path member 10. This reduces the thermal stress difference that occurs in the first flow path member 10 due to the heat of the exhaust gas, thereby increasing the heat resistance strength of the exhaust heat recovery device 2.

[0074] [Other Embodiments] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0075] In the first embodiment, the fluid that cools the exhaust gas may be other than cooling water, and a medium such as a liquid or gas that is suitable for heat exchange can be applied.

[0076] In this embodiment, the valve mechanism 40 has a structure in which a pair of connecting portions 42b support both ends of the shutter main body 42a. However, for example, there may be one connecting portion 42b in the center of the shutter main body 42a. Alternatively, there may be a plurality of connecting portions 42b arranged in parallel, forming a so-called louver.

[0077] In the exhaust heat recovery device 2 according to the second embodiment, the inner member 50 provided inside the first flow path member 10 may be structured to be divided along a horizontal plane including the axis of the rotary shaft portion 44 of the valve mechanism 40. Alternatively, the inner member 50 may be structured to be divided along a plane perpendicular to the axis of the rotary shaft portion 44 of the valve mechanism 40.

[0078] This application claims priority based on Japanese Patent Application No. 2023-117570, filed with the Japan Patent Office on July 19, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. An exhaust heat recovery device that recovers heat from exhaust gas discharged from an engine by heat exchange with a fluid, comprising: a first flow path member having a first flow path formed therein through which exhaust gas flows; a second flow path member provided adjacent to the first flow path member, having a second flow path formed therein that bypasses a portion of the first flow path, and having a heat exchange portion that exchanges heat between the exhaust gas flowing in the second flow path and the fluid; and a valve mechanism provided in the first flow path, wherein the first flow path member has: an exhaust gas outlet from the first flow path to the second flow path; an exhaust gas inlet from the second flow path to the first flow path; and a first upright portion that is located upstream of the inlet in the first flow path, extends in a direction perpendicular to the exhaust gas flow direction and upright toward the inside of the first flow path, and the valve mechanism comprises: a rotating shaft portion; and a valve body that rotates in conjunction with the rotation of the rotating shaft portion to close or open the first flow path; an exhaust heat recovery device comprising: a shutter portion that rotates with rotation of the rotating shaft portion and blocks or obstructs the flow of exhaust gas from the inlet; in a heat recovery state, the valve body of the valve mechanism blocks the first flow path and the shutter portion opens the flow of exhaust gas from the inlet; in a heat non-recovery state, the valve body of the valve mechanism opens the first flow path and the shutter portion blocks or obstructs the flow of exhaust gas from the inlet; in the heat non-recovery state, a gap is formed in the direction separating the inlet and the shutter portion; in a height direction from the outside to the inside of the first flow path, the first upright portion is formed larger than the gap; and in the heat non-recovery state, a tip of the shutter portion abuts or is close to the first upright portion.

2. An exhaust heat recovery device as described in claim 1, wherein the shutter portion has a convex portion protruding outward in the direction of the radius of rotation of the rotating valve mechanism, and in the non-heat recovery state, the convex portion abuts or is close to the inner wall of the first flow path member downstream of the inlet in the flow direction of the exhaust gas, and in the non-heat recovery state, rotation of the valve mechanism is restricted by at least one of the tip of the shutter portion abutting the first upright portion or the convex portion abutting the inner wall of the first flow path member.

3. An exhaust heat recovery device as described in claim 1, wherein the first upright portion abuts or faces the tip of the shutter portion on a downstream surface in the exhaust gas flow direction, and abuts or faces the valve body on an upstream surface in the exhaust gas flow direction.

4. An exhaust heat recovery device as described in claim 1, wherein the first flow path member has a second upright portion extending in a direction perpendicular to the exhaust gas flow direction and upright toward the inside of the first flow path, the second upright portion is located on the inner surface of the first flow path on the side opposite to the first upright portion and upstream of the first upright portion in the exhaust gas flow direction, the first upright portion abuts or faces the valve body on its upstream surface in the exhaust gas flow direction in the heat recovery state, the second upright portion abuts or faces the valve body on its downstream surface in the exhaust gas flow direction in the heat recovery state, and the valve body abuts at least one of the first upright portion and the second upright portion in the heat recovery state.

5. An exhaust heat recovery device as claimed in claim 4, comprising an inner member covering at least a portion of the inner surface, the first raised portion and the second raised portion being formed at a downstream end of the inner member in the flow direction of the exhaust gas.

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