JP6170842B2 - Exhaust heat recovery device - Google Patents

Description

  The present invention relates to an exhaust heat recovery apparatus.

  Conventionally, as an exhaust heat recovery device, a first flow path for exhaust gas to pass through a heat exchanger on the exhaust system and a second flow path to bypass the heat exchanger are provided, and these flow paths can be opened and closed by opening and closing the valve body. The switching is controlled, the heat exchanger is provided above the first flow path, and the second flow is provided downstream of the communication port that communicates the junction of the first flow path and the second flow path and the second flow path. A valve shaft of a first valve body that opens and closes a path is provided, and a second valve body that is separate from the first valve body is provided on the valve shaft (for example, see Patent Document 1). .

JP 2012-246835 A

  In the conventional exhaust heat recovery device, the valve shaft of the second valve body that opens and closes the communication port is provided on the downstream side of the communication port, the first valve body is located on the downstream side of the valve shaft, and the second valve body Is located on the upstream side of the valve shaft, so that it is necessary to secure the rotation space of the second valve body in addition to the rotation space of the first valve body. It was an obstacle to doing.

  Therefore, an object of the present invention is to provide an exhaust heat recovery device that can be made smaller than the conventional exhaust heat recovery device.

In order to solve the above-mentioned problem, the invention according to claim 1 is a heat exchanger that performs heat exchange between exhaust gas and a medium in an exhaust system such as an internal combustion engine, a first flow path through which the exhaust gas passes, A second flow path through which the exhaust gas bypasses the heat exchanger, and a merge portion where the first flow path and the second flow path merge;
A first communication portion that communicates the second flow path and the merge portion; a second communication portion that communicates the first flow path and the merge portion; a valve shaft provided on the upstream side of the second communication portion; A first valve body that rotates about the valve shaft to open and close the first communication portion; and a second valve body that rotates about the valve shaft to open and close the second communication portion,
A pair of arm portions for attaching the first valve body to the valve shaft is provided on both sides of the second communication portion, and the second communication portion is positioned between the pair of arm portions. To do.

  According to a second aspect of the present invention, in the first aspect of the present invention, the valve shaft is provided so as to penetrate the case, a housing that forms a part of the first flow path is provided in the case, and the valve A bearing for supporting the shaft is provided in the housing, and a seal member is provided in a case portion through which the valve shaft passes.

  According to a third aspect of the invention, in the first or second aspect of the invention, the first valve body and the second valve body are integrally formed.

  According to the present invention, a first communication part that communicates with the second flow path, a second communication part that communicates the first flow path and the merging part, a valve shaft provided on the upstream side of the second communication part, A first valve body that rotates about the valve shaft and opens and closes the first communication portion; and a second valve body that rotates about the valve shaft and opens and closes the second communication portion. A pair of arm portions for attaching a body to the valve shaft is provided on both side portions of the second communication portion, and the second communication portion is positioned between the pair of arm portions. The second valve body can be positioned in the rotation space of the above, and can be made smaller than the exhaust heat recovery device of the prior art.

1 is a front view of an exhaust heat recovery apparatus according to Embodiment 1 of the present invention. The top view of FIG. The left view of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. Sectional drawing of the state which opened the 1st valve body from the state of FIG. BB sectional drawing of FIG. The CC sectional view taken on the line of FIG. The DD sectional view taken on the line of FIG. The EE sectional view taken on the line of FIG. FF sectional view taken on the line of FIG. The GG sectional view taken on the line of FIG. Sectional drawing equivalent to the EE line | wire of FIG. 1 in the exhaust heat recovery apparatus of Example 2 of this invention. Sectional drawing equivalent to the AA line of FIG. 2 in the exhaust heat recovery apparatus of Example 3 of this invention.

A mode for carrying out the present invention will be described based on an embodiment shown in the drawings.
[Example 1]
1 to 11 show a first embodiment of the present invention.

  The exhaust heat recovery apparatus 1 according to the first embodiment is disposed in an exhaust system of a vehicle or the like that uses an internal combustion engine. An upstream exhaust pipe (not shown) is provided at an upstream side of an inflow port 1a. A downstream exhaust pipe (not shown) is connected to 1b.

  As shown in FIG. 4, the exhaust heat recovery apparatus 1 has a case 2, and a heat exchanger 3, a first flow path 4 passing through the heat exchanger 3, and the heat exchanger 3 are included in the case 2. A second flow path 5 that bypasses is provided. The second flow path 5 communicates with the upstream exhaust pipe and the downstream exhaust pipe.

  As shown in FIGS. 1 to 3, the case 2 includes a cylindrical main body 2 a and a reduced diameter portion 2 b provided on the downstream side of the main body 2 a. 3 to 6, the second flow path 5 is formed by a cylindrical tube that is open at both ends, and is disposed at the center of the main body 2 a of the case 2 as shown in FIG. 5. Yes.

  Two heat exchangers 3 are provided between the main body 2 a of the case 2 and the second flow path 5 so as to be located on both sides of the axis of the second flow path 5. As shown in FIG. 8, both the heat exchangers 3 and 3 are formed in the circular arc shape centering on the axial center of the main-body part 2a. The heat exchanger 3 has a medium flow path 3a through which a medium such as cooling water of a cooling system such as an internal combustion engine flows, and a fluid flow path 3b through which an exhaust gas fluid flows. As shown in FIGS. 1 to 5, the medium flow path 3a has a medium inlet 10a and a medium outlet 10b, and the medium inlet 10a and the medium outlet 10b are connected to a cooling system such as an internal combustion engine. . Thereby, in the heat exchanger 3, heat exchange can be performed between the medium and the exhaust gas.

  In a state where the exhaust heat recovery device 1 is installed in a vehicle or the like, as shown in FIGS. 1 and 4, the medium inlet 10 a is located below the second flow path 5, and the medium outlet 10 b is set in the second flow path 5. It is provided so that it may be located above. The medium flows in from the medium inlet 10a, branches into the left and right medium flow paths 3a, 3a at the branching section 10c, and flows upward in the medium flow paths 3a, 3a from the lower side to the upper side. It merges and is discharged from the medium outlet 10b.

  A cross section perpendicular to the axis of the main body 2a of the case 2 in the fluid flow path 3b is formed in an arc shape as shown in FIG. Further, as shown in FIG. 4, a plurality of fluid flow paths 3b are provided in parallel from the upstream side toward the downstream side. Although the number of the fluid flow paths 3b is arbitrary, in this embodiment, the left and right heat exchangers 3, 3 are each provided with four fluid flow paths 3b. Moreover, although the shape of the fluid flow path 3b is arbitrarily formed, it is preferable to form the outer edge portion 3c of the inner peripheral surface in a curved shape, and the outer edge portion 3c of the inner peripheral surface is thus formed in a curved shape. Thus, when the fluid flows in the fluid flow path 3b, the fluid always hits the outer edge 3c of the inner peripheral surface, so that the turbulent flow of the exhaust gas flowing is promoted and the heat exchange efficiency can be improved.

  In the main body 2a of the case 2, a recovery space 13 for recovering condensed water generated when the exhaust gas performs heat exchange or the like in the fluid flow path 3b is provided in the lower part of the heat exchanger 3, and the heat exchanger 3 Is provided with a space 14 where exhaust gases flowing through the left and right fluid flow paths 3b merge. The fluid flow path 3b communicates with the recovery space 13 and the space 14, and the fluid flow path 3b, the recovery space 13 and the space 14 etc., the 1st flow path 4 is comprised. Thus, the heat exchangers 3 and 3 are provided on both side portions in the case 2 and are not provided on the upper and lower portions of the case 2.

  As shown in FIGS. 4 and 6, a communication hole 18 is formed in the lower part of the second flow path 5, and the second flow path 5 communicates with the recovery space 13 through the communication hole 18 and a heat exchanger. 3 fluid flow paths 3b.

  A junction 21 where the second flow path 5 and the first flow path 4 merge is provided downstream of the communication hole 18. The second flow path 5 is formed with a first communication portion 24 that communicates the second flow path 5 and the merging portion 21. Further, the first flow path 4 is formed with a second communication portion 25 that communicates the space 14 of the first flow path 4 and the merging portion 21. The second communication part 25 is formed so as to be positioned above the first communication part 24. The second communication part 25 is formed in a housing 26 provided on the downstream side of the space 14. In the housing 26, only the upstream and downstream second communication portions 25 are opened, and the upstream opening communicates with the space 14.

  As shown in FIG. 9, a valve shaft 27 is provided on the upstream side of the second communication portion 25 so as to penetrate the left and right walls of the housing 26. As shown in FIGS. 4 and 5, the downstream end portion of the housing 26 is formed in an arc shape centering on the valve shaft 27, and the second communication portion 25 is formed in the arc portion.

  The valve shaft 27 is supported by bearings 29 and 29 provided on both sides in the housing 26. A bearing case 34 is provided on the outer periphery of the bearings 29 and 29 over the entire left and right direction of the first flow path 4. The housing 26 and the bearing case 34 prevent the exhaust gas in the first flow path 4 from coming into contact with the valve shaft 27.

  A pair of arm portions 30a, 30a formed on the swing arm type first valve body 30 is fixed to the valve shaft 27 protruding leftward and rightward in the axial direction from the housing 26, and the valve shaft 27 is rotated forward and backward. The first valve body 30 can be rotated forward and backward to open and close the second flow path 5. As shown in FIG. 10, the pair of arm portions 30 a and 30 a are provided in the axial direction of the valve shaft 27 so as to be longer than the length of the second communication portion 25 in the left-right direction. On the side surface of the second flow path 5 of the first valve body 30, a sealing material 30 b that contacts and separates from the first communication portion 24 is fixed.

  As shown in FIG. 9, the valve shaft 27 is provided so as to penetrate the case 2, and a seal member 28 is provided on the outer periphery of the valve shaft 27 and so as to penetrate the case 2. The seal member 28 has a labyrinth structure that prevents the exhaust gas from leaking out of the case 2.

  In the conventional exhaust heat recovery device, since the bearing is provided so as to penetrate the case, the bearing suppresses the exhaust gas from leaking outside the case in addition to supporting the valve shaft. Because it is necessary to do so, the bearing becomes large. On the other hand, in the present embodiment, the bearing 29 and the seal member 28 are configured as separate members, and the bearing 29 is provided in the case 2, so that the seal member 28 does not need a function of the bearing, and the exhaust gas is not generated. Since it is only necessary to suppress leakage outside the case 2, the axial length of the seal member 28 can also be shortened. Further, since the bearing 29 only needs to consider the durability as a bearing, the diameter of the bearing 29 can be made smaller than the diameter of the bearing of the exhaust heat recovery device of the prior art, and the exhaust heat recovery device 1 Can be made smaller than the conventional exhaust heat recovery device.

  In the first valve body 30, a second valve body 31 is formed integrally with the first valve body 30 so as to be positioned between the arm portions 30 a and 30 a. The second valve body 31 is formed in an arc shape centered on the valve shaft 27, and the second valve body 31 is formed on the downstream side portion of the housing 26 by rotating the valve shaft 27 forward and backward. The second communication part 25 can be opened and closed by moving in the vertical direction along the part. The upstream side surface of the second valve body 31 may or may not be provided with a sealing material. In this embodiment, no sealing material is provided.

  The first valve body 30 and the second valve body 31 rotate integrally around the valve shaft 27, and when the first valve body 30 is opened as shown in FIG. Is closed to close the second communication portion 25. Also, as shown in FIG. 4, when the first valve body 30 is closed, the second valve body 31 is opened and the second communication portion 25 is opened. Is to be released.

  The junction 21 and the recovery space 13 communicate with each other through a discharge hole 23a formed at the lower end of the partition wall 23 provided between them, and the condensed water recovered in the recovery space 13 passes through the discharge hole 23a. After being discharged to the merging portion 21, it is discharged to the outside together with the exhaust gas.

  As shown in FIG. 11, a medium flow path 32 that guides the medium in the medium flow path 3 a to the heat receiving portion of a thermo-element 36 that is a temperature-actuated actuator provided outside the case 2 is provided above the heat exchanger 3. Is provided. Wax is stored in the heat receiving portion. Note that the heat receiving portion of the thermo element 36 may be provided directly in the medium flow path 3 a of the heat exchanger 3.

  A rod 38 urged toward the thermo element 36 by the urging member 37 is in contact with the distal end portion of the thermo element 36. When the wax in the thermo element 36 reaches a predetermined temperature or more, it thermally expands, its tip portion expands, and the rod 38 is pushed and moved by the tip portion, whereby the valve shaft 27 rotates, as shown in FIG. As described above, the first valve body 30 is opened to open the second flow path 5, and the second valve body 31 is closed to close the first flow path 4.

  Further, when the wax in the thermo element 36 becomes lower than a predetermined temperature, the wax contracts, the tip of the wax contracts, the rod 38 is urged by the urging member 37, and the valve shaft 27 rotates, so that FIG. As shown, the first valve body 30 is closed to close the second flow path 5, and the second valve body 31 is opened to open the first flow path 4.

  When the medium of the heat exchanger 3 is lower than a predetermined temperature, the second flow path 5 is closed and the first flow path 4 is opened as shown in FIG. After passing through the communication hole 18 from the second flow path 5, it passes through the recovery space 13, the fluid flow path 3 b of the heat exchanger 3, and the space 14, and flows from the second communication section 25 to the merging section 21. .

  Condensed water generated when the exhaust gas undergoes heat exchange moves downward in the fluid flow path 3b by its own weight and is recovered into the recovery space 13, and then is recovered through the exhaust hole 23a and the merging portion 21. It is discharged downstream of the device 1. Further, by forming the medium flow path 3a in an arc shape communicating in the vertical direction, when bubbles are generated due to boiling of the medium in the medium flow path 3a, the bubbles easily move upward, It is preferable that air bubbles escape from the medium flow path 3a.

  On the other hand, when the medium of the heat exchanger 3 is at a predetermined temperature or higher, the second flow path 5 is opened and the first flow path 4 is closed as shown in FIG. Then, it passes through the second flow path 5 and flows to the junction 21.

  Since the heat receiving portion of the thermo-element 36 that is a temperature-actuated actuator comes into contact with the medium in the medium flow path 3a of the heat exchanger 3, the thermo-element responds immediately to the temperature of the medium in the heat exchanger 3. 36 operates and it can prevent that the medium temperature of the heat exchanger 3 becomes high too much.

  The second valve body 31 is disposed between the pair of arm portions 30a, 30a of the first valve body 30, and the first valve body 30 and the second valve body 31 are integrally formed, whereby the second valve body 31 is formed. Since 31 can be disposed in the rotation space of the first valve body 30, it can be made smaller than the exhaust heat recovery device of the prior art. Moreover, since the 2nd valve body 31 can be simultaneously manufactured in series with the material between the arm parts 30a and 30a of the 1st valve body 30 in the material which manufactures the 1st valve body 30, the material of the 1st valve body 30 The yield and the cost and man-hours can be reduced.

  In the conventional exhaust heat recovery apparatus, it is necessary to provide bearings for supporting the valve shaft on the left and right inner walls of the case. However, in this embodiment, since the bearings 29 and 29 are provided and supported on the housing 26 in the case 2, it is only necessary to provide the seal member 28 on the outer peripheral wall of the case 2 at the portion through which the valve shaft 27 passes. Compared with the conventional exhaust heat recovery device, the length of the exhaust heat recovery device 1 in the direction of the valve shaft 27 can be shortened, and the size can be reduced. Moreover, since the bearings 29 and 29 should just ensure the durability as a bearing, the diameter of the bearing 29 can be made smaller than the diameter of the bearing of the said conventional exhaust heat recovery apparatus, and size reduction is achieved. I can do it.

  Note that the temperature-actuated actuator may be bimetal or shape memory alloy, and the valve body may be rotated by changing the shape thereof.

  A valve system that opens and closes according to the flow rate of exhaust gas is well known in the exhaust system as a so-called variable valve, and an arbitrary mechanism can be used.

[Example 2]
In the first embodiment, the two bearings 29 and 29 are provided in the housing 26. However, the bearings 29 and 29 are not provided, and both end portions of the valve shaft 27 are arranged on the left and right sides of the case 2 as shown in FIG. You may make it support by the 1st bearing 42 provided penetrating the inner wall, and the other 2nd bearing 43. FIG. The first bearing 42 has a labyrinth structure that prevents the exhaust gas from leaking out of the case 2.

  Further, a sealing material 41 is wound around the entire valve shaft 27 in the housing 26 to suppress contact between the exhaust gas and the valve shaft 27, and the housing 26 and the valve shaft 27. The exhaust gas is prevented from leaking out of the housing 26 from between.

Since other structures are the same as those of the first embodiment, the description thereof is omitted.
Also in the second embodiment, the same operations and effects as the first embodiment are exhibited.

  In the second embodiment, since the first bearing 42 and the second receiving shaft 43 are provided on the left and right inner walls of the case 2, the second flow path 5 of the exhaust heat recovery apparatus 1 is compared with the first embodiment. The length in the direction orthogonal to the axis of

[Example 3]
In the first and second embodiments, the first valve body 30 and the second valve body 31 are integrally formed. However, the first valve body 30 and the second valve body 31 may be formed separately.

  For example, as shown in FIG. 13, the 1st valve body 30 and the arm parts 30a and 30a are formed integrally, and the 2nd valve body 31 is formed separately from these. Further, the second valve body 31 is disposed between the arm portions 30 a and 30 a, and the lower end portion of the second valve body 31 is fixed to the first valve body 30.

Since other structures are the same as those of the first and second embodiments, description thereof is omitted.
Also in the third embodiment, the same operations and effects as those of the first embodiment are exhibited.

[Example 4]
A second communication portion 25 is provided above the first communication portion 24, a valve shaft 27 is provided on the upstream side of the second communication portion 25, and the first valve element is disposed on the valve shaft 27 positioned on the left and right of the second communication portion 25. 30 arm portions 30a, 30a are fixed, and if the second valve body 31 is provided between the pair of arm portions 30a, 30a, the first flow path 4, the second flow path 5, and the heat exchanger 3 The shape and arrangement can be set arbitrarily. For example, as in the exhaust heat recovery device of Patent Document 1, the first flow path 4 and the second flow path 5 may be provided in parallel, and the exhaust gas may flow in the lateral direction in the heat exchanger 3. .

Since other structures are the same as those in the first to third embodiments, description thereof is omitted.
Also in the fourth embodiment, the same operations and effects as those of the first embodiment are exhibited.

[Other Examples]
In the above-described embodiment, the temperature-actuated actuator is used. However, any actuator can be used as long as the actuator is not limited to the temperature-actuated actuator. For example, a negative pressure actuator or an electric actuator can be used.

  The present invention is not limited to a narrowly-defined heat recovery device (heat collector, oil warmer, etc.) whose main purpose is heat recovery to a medium, but is also a heat exchanger (exhaust cooler, EGR cooler, etc.) whose main purpose is cooling exhaust gas ) Is also included as a heat recovery device. Furthermore, the application target is not limited to an internal combustion engine such as a vehicle, but can be applied to an exhaust system of a device that generates any exhaust gas such as a general-purpose engine or a stationary combustion device.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and any design changes that do not depart from the spirit of the present invention are included in the present invention. It is.

1 Exhaust heat recovery device.
Reference Signs List 3 Heat exchanger 4 First flow path 5 Second flow path 21 Merge section 24 First communication section 25 Second communication section 26 Housing 27 Valve shaft
28 Seal member 29 Bearing 30 First valve body 30a Arm 31 Second valve body

Claims (3)

In an exhaust system such as an internal combustion engine, a heat exchanger that performs heat exchange between exhaust gas and a medium, a first flow path through which the exhaust gas passes, a second flow path through which the exhaust gas bypasses the heat exchanger, Having a merge portion where the first flow path and the second flow path merge;
A first communication portion that communicates the second flow path and the merge portion; a second communication portion that communicates the first flow path and the merge portion; a valve shaft provided on the upstream side of the second communication portion; A first valve body that rotates about the valve shaft to open and close the first communication portion; and a second valve body that rotates about the valve shaft to open and close the second communication portion,
A pair of arm portions for attaching the first valve body to the valve shaft is provided on both sides of the second communication portion, and the second communication portion is positioned between the pair of arm portions. Exhaust heat recovery device.   The valve shaft is provided so as to penetrate the case, a housing constituting a part of the first flow path is provided in the case, a bearing for supporting the valve shaft is provided in the housing, and the valve shaft penetrates The exhaust heat recovery apparatus according to claim 1, wherein a sealing member is provided in a case portion to be operated. The exhaust heat recovery apparatus according to claim 1 or 2, wherein the first valve body and the second valve body are integrally formed.

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