JP5291656B2 - Waste heat recovery device - Google Patents

Description

  The present invention relates to an exhaust heat recovery apparatus that recovers exhaust heat by transmitting heat of exhaust gas to cooling water.

  By operating the vehicle engine, hot exhaust gas is generated. There is known an exhaust heat recovery device that warms cooling water with the heat of this high-temperature exhaust gas (see, for example, Non-Patent Document 1 (FIGS. 1 and 4)).

Non-Patent Document 1 will be described with reference to the following figure.
As shown in FIG. 6, the exhaust heat recovery apparatus 100 includes an introduction member 101 into which exhaust gas is introduced, a cylindrical main body 102 connected to the introduction member 101, and exhaust gas that is connected to the main body 102 to the outside. A discharge member 103 that discharges; a partition wall 104 that divides the main body 102 up and down; a first passage 107 that includes a heat exchanger 105 disposed at an upper portion of the partition wall 104 and heats the cooling water with the heat of the exhaust gas; A second passage 108 that is disposed below the first passage 107 with the partition wall 104 interposed therebetween and bypasses the first passage 107, a rotary shaft 109 provided on the upstream side of the partition wall 104, and the rotary shaft 109 The valve 111 is supported and closes either the first passage 107 or the second passage 108 to define the exhaust gas flow path.

  When the valve 111 closes the second passage 108, the exhaust gas passes through the first passage 107. The heat of the exhaust gas passing through the first passage 107 is transmitted to the cooling water by the heat exchanger 105, and the temperature of the cooling water rises. After the temperature of the cooling water rises to a predetermined temperature, the first passage 107 is closed by the valve 111 and the exhaust gas is passed through the second passage 108. By passing the exhaust gas through the second passage 108, the heat exchange is completed. When the temperature of the cooling water falls below a predetermined temperature, the second passage 108 is closed again by the valve 111, and the exhaust gas is passed through the first passage 107.

  The rotating shaft 109 is connected to a thermoactuator (FIG. 7, reference numeral 113) that operates at the temperature of the cooling water. Such a thermoactuator will be described with reference to the next figure.

  As shown in FIG. 7, the thermoactuator 113 includes a case 116 in which a cooling water introduction unit 114 and a cooling water discharge unit 115 are provided and wax is stored therein, and a piston that is stored in the case 116 and is operated by the wax. 117, a rod 121 disposed at the tip of the piston 117 via an absorption spring 118, a lid 122 that houses a part of the rod 121 and is connected to the case 116, and a wax that is housed in the lid 122 And a return spring 123 for returning the rod 121 at the time of contraction.

  One end of a lever 125 is connected to the tip of the rod 121 of such a thermoactuator 113 via a pin 124, and the rotating shaft 109 is connected to the other end of the lever 125.

  By performing heat exchange, the temperature of the cooling water sent from the cooling water introduction unit 114 increases. When the temperature rises, the wax stored in the case 116 starts to melt. As the wax melts, the volume of the wax expands, and the piston 117 extends toward the left side of the drawing against the force of the return spring 123. As a result, the rod 121 is moved leftward. The lever 125 and the valve 111 are rotated clockwise around the rotation shaft 109, whereby the first passage (FIG. 6, reference numeral 107) is closed (see the imaginary line).

  The valve | bulb 111 closes the 1st channel | path 107 because a front-end | tip contacts the introduction member (FIG. 6, code | symbol 101). For this reason, the piston rod 121 cannot advance to the left from the position indicated by the imaginary line. If the wax is further expanded in a state where the valve 111 closes the first passage (indicated by an imaginary line), the movement of the piston 117 to the left is absorbed by the absorption spring 118. The absorption spring 118 absorbs the movement of the piston 117, thereby preventing the rod 121 from moving to the left side.

  The movement of the piston 117 with the first passage 107 closed in this way is called overlift. That is, the absorption spring 118 absorbs overlift.

  On the other hand, when the temperature of the cooling water is lowered from the state indicated by the imaginary line, the wax in the case 116 is solidified and the volume of the wax is reduced. As a result, the return spring 123 extends toward the right side of the drawing. As a result, the rod 121 is moved rightward, and the lever 125 and the valve 111 are rotated counterclockwise. By turning, the second passage (FIG. 6, reference numeral 108) is closed.

  By the way, according to such a thermo actuator 113, the space for mounting the absorption spring 118 is required, and the thermo actuator 113 is enlarged. When the thermoactuator 113 is large, the degree of freedom of arrangement of the thermoactuator 113 decreases.

  Miniaturization of the thermoactuator used in the exhaust heat recovery device is desired.

Japanese Patent Application No. 2009-0765887

  An object of the present invention is to reduce the size of a thermoactuator used in an exhaust heat recovery apparatus.

The invention according to claim 1 includes a first passage provided with a heat exchanger through which exhaust gas flows and transmits heat of the exhaust gas to cooling water, and a second passage provided around the first passage. A rotating shaft provided upstream of the first and second passages, a thermoactuator connected to the rotating shaft and operating when the temperature of the cooling water exceeds the first set temperature, and the first setting In the exhaust heat recovery apparatus comprising a valve attached to the rotary shaft so as to be operated in a direction to close the first passage when the temperature is exceeded,
When the temperature of the cooling water exceeds a second preset temperature higher than the first preset temperature, the valve of the valve is used to absorb the overlift when the thermoactuator operates over a predetermined range. A pocket portion formed in a shape along the locus of the tip while maintaining a predetermined gap is provided in the first passage.

  The invention according to claim 2 is characterized in that the pocket portion is provided on the downstream side of the introduction port into which the exhaust gas is introduced in a side view.

  In the invention according to claim 1, the first passage is provided with a pocket portion formed in a shape along the locus of the tip of the valve while maintaining a predetermined gap. Since the pocket portion has a shape along the locus of the tip of the valve, the valve can be further operated from the state where the valve closes the first passage. Even when the thermoactuator is operated beyond the predetermined range, the excess can be absorbed by the pocket portion. Since it absorbs in a pocket part, it is not necessary to arrange | position an absorption spring in a thermo actuator. The thermoactuator can be miniaturized by the amount that the absorbing spring is not disposed.

  In the invention according to claim 2, the pocket portion is provided on the downstream side of the introduction port into which the exhaust gas is introduced in a side view. That is, only the thermoactuator is reduced in size without increasing the size around the inlet. By reducing the size of only the thermoactuator, the exhaust heat recovery device as a whole can be reduced in size.

It is a perspective view of the waste heat recovery device concerning the present invention. It is sectional drawing of the waste heat recovery apparatus which concerns on this invention. It is sectional drawing of the thermo actuator used for a waste heat recovery apparatus. It is a figure explaining the relationship between the temperature of a cooling water, and the position of a valve | bulb. It is a figure which compares the conventional thermoactuator and the thermoactuator which concerns on an Example. It is a figure explaining the conventional waste heat recovery apparatus. It is a figure explaining the conventional thermo actuator.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

First, Embodiment 1 of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the exhaust heat recovery apparatus 10 includes an introduction member 12 into which exhaust gas is introduced from a cylindrical introduction port 11, a bypass circuit 14 connected to the bypass port 13 of the introduction member 12, and an introduction Heat exchange for providing cooling water with heat of exhaust gas supported by a gas inflow member 17 connected to the heat recovery port 16 of the member 12 and a rectangular heat exchanger support 17a formed integrally with the gas inflow member 17 The heat exchanger 18, the heat exchanger support 21 a that supports the heat exchanger 18, and the exhaust gas exhaust member 21 that exhausts the exhaust gas after the heat exchange, and the side surface of the heat exchanger 18. A cooling water introduction pipe 22 for introducing cooling water into the heat exchanger 18, a cooling water discharge pipe 24 from which the cooling water introduced into the heat exchanger 18 is discharged from the cooling water introduction pipe 22 and supported by the support member 23, The support member together with the cooling water discharge pipe 24 A thermo-actuator 25 which is supported operated at a temperature of the cooling water to 3, in contact with the tip of the thermo-actuator 25 consists of biasing means 26 for biasing the drawing clockwise.

The gas inflow member 17 for flowing the exhaust gas and the end 17a for supporting the heat exchanger 18 are integrally formed. By forming these integrally, the number of parts can be reduced. The same applies to the gas outflow member 21 and the end 21a of the gas outflow member. By making the shape of a split line, the number of parts can be reduced.
Details of the exhaust gas flow path of the exhaust heat recovery apparatus 10 will be described with reference to the following drawings.

  As shown in FIG. 2, a rotation shaft 27 is provided perpendicular to the axial direction of the introduction member 12, and a V-shaped valve 29 is attached to the rotation shaft 27 via a bolt 28.

  The introduction member 12 includes an introduction port 11 through which exhaust gas is introduced, a pocket portion 33 bulged along the locus of the tip 32 of the V-shaped valve 29 above the introduction port 11, and gas from the pocket portion 33. The heat recovery port 16 connected to the inflow member 17, the boundary 34 between the heat recovery port 16 and the pocket 33, the boundary 34 where the heat recovery port 16 is closed by the rotation of the V-shaped valve 29, and the introduction port 11 A seat portion 36 that is bent downward from the end of the seat and on which the other end 35 of the V-shaped valve 29 is seated, a detour port 13 that is connected to the detour 14 on the downstream side of the seat portion 36, and an upper portion of the detour port 13. And a bulging portion 37 bulged. The pocket portion 33 is provided on the downstream side of the introduction port 11 in a side view.

  The heat exchanger 18 has a core case 41 having one end connected to the gas inflow member 17 and the other end connected to the gas outflow member 21, and a plurality of (four in this example) are housed in the core case 41 in a stacked state. And a heat transfer member 42 through which exhaust gas flows and end plates 43 and 43 that support both ends of the heat transfer member 42.

  The rotating shaft 27 is urged clockwise by urging means (FIG. 1, reference numeral 26). The other end 35 of the V-shaped valve 29 is seated on the seat portion 36 with a force that biases it clockwise.

  When the V-shaped valve 29 closes the bypass port 13, exhaust gas generated in the internal combustion engine flows from the introduction port 11 toward the first passage 45. That is, the first passage 45 includes the pocket portion 33, the heat recovery port 16, the gas inflow member 17, the heat exchanger 18, and the gas outflow member 21.

  Exhaust gas is passed through the heat transfer member 42, and cooling water is passed outside the heat transfer member 42. The heat of the exhaust gas is transmitted to the cooling water through the heat transfer member 42, and the cooling water is warmed. That is, heat is exchanged between the exhaust gas and the cooling water.

  On the other hand, the tip 32 of the V-shaped valve 29 is rotated counterclockwise to the boundary portion 34 or the pocket portion 33 together with the rotating shaft 27, whereby the heat recovery port 16 is closed. By closing the heat recovery port 16, the exhaust gas introduced from the introduction port 11 flows toward the second passage 46. That is, the second passage 46 includes the seating portion 36, the bypass port 13, and the bypass route 14.

The V-shaped valve 29 is rotated by the exhaust gas flow rate or the cooling water temperature.
That is, when the flow rate of the exhaust gas is large, the exhaust gas directly rotates the V-shaped valve 29 counterclockwise against the force of the urging means (FIG. 1, reference numeral 26).

  On the other hand, when the temperature of the cooling water exceeds a predetermined first set temperature, the thermoactuator (FIG. 1, reference numeral 25) operates. By operating the thermoactuator, the rotating shaft 27 is rotated against the force of the urging means. The V-shaped valve 29 is rotated together with the rotating shaft 27. Details of the thermoactuator will be described with reference to the following figure.

  As shown in FIG. 3, the thermoactuator 25 includes a wax storage portion 47, a case 51 provided so as to surround the wax storage portion 47 and having a cooling water introduction portion 48 and a cooling water discharge portion 49, and the inside of the case 51. A piston 52 housed in the wax housing part 47 and actuated by wax, a rod support part 53 extending from the piston 52, a lid 54 housing a part of the rod support part 53 and connected to the case 51, A rod 55 having a tip facing the outside from the lid 54, a return spring 56 disposed so as to surround the base portion 55a of the rod 55 and returning the rod 55 when the wax contracts, and preventing the return spring 56 from coming off In order to do this, it consists of a retaining member 57 provided integrally with one end of the rod 55. This retaining member 57 is pushed by the rod support member 53.

  Wax or the like is housed inside the case 51 and the lid 54 that can be attached to and detached from the case 51. By making the lid 54 detachable, maintenance of the thermoactuator 25 is facilitated.

  In addition, the number of parts of the thermoactuator 25 is reduced by the amount of the absorption spring (FIG. 7, reference numeral 118) compared to the conventional thermoactuator. By reducing the number of parts, the maintenance of the thermoactuator 25 is further facilitated.

  If heat exchange is performed, the temperature of the cooling water sent from the cooling water introduction part 48 will rise. When the temperature rises and the temperature of the cooling water reaches the first set temperature, the wax starts to melt. As the wax melts, the volume of the wax expands, and the piston 52 moves forward toward the left side of the drawing against the force of the return spring 56. As a result, the rod 55 is moved in the left direction.

  An urging means (FIG. 1, reference numeral 26) is connected to the tip of the rod 55, and the urging means urges a V-shaped valve (FIG. 2, reference numeral 29) via a rotating shaft (FIG. 2, reference numeral 27). To do. As the wax expands, the rod 55 moves forward against the force of the urging means and rotates the V-shaped valve.

  On the other hand, when the temperature of the cooling water is lowered from the state where the wax is expanded, the wax is solidified. By solidifying, the volume of the wax is reduced. By contracting, the return spring 56 extends toward the right side of the drawing. The rod 55 is moved rightward.

As the rod 55 moves backward, the urging means (FIG. 1, reference numeral 26) rotates the rotating shaft (FIG. 2, reference numeral 27) and the V-shaped valve (FIG. 2, reference numeral 29).
The details of how the V-shaped valve is actuated by the advancement and retraction of the rod 55 will be described with reference to the following drawings.

  As shown in FIG. 4A, when the temperature of the cooling water rises and the rod (FIG. 3, reference numeral 55) moves forward, the V-shaped valve 29 is rotated counterclockwise. The heat recovery port 16 is closed by the tip 32 of the V-shaped valve 29 rotating to the boundary 34.

  As described with reference to FIG. 2, when the temperature of the cooling water is equal to or lower than the first set temperature, the V-shaped valve 29 is in a state where the second passage 46 is closed. As the temperature of the cooling water gradually rises from the first set temperature to the second set temperature, the heat recovery port 16 is gradually closed and the bypass port 13 is gradually opened. That is, the state shown in FIG.

  When the cooling water reaches the second set temperature, the heat recovery port 16 is closed. By closing the heat recovery port 16 (first passage 45), the exhaust gas flows toward the bypass port 13 (second passage 46). The temperature at which the heat recovery port 16 is closed is the second set temperature. The exhaust heat recovery apparatus 10 finishes the heat exchange when the cooling water reaches the second set temperature.

  Returning to FIG. 1, the thermoactuator 25 is connected to the support member 23. There is a slight time lag from when the cooling water in the heat exchanger 18 reaches the second set temperature until the cooling water at the second set temperature reaches the thermoactuator 25.

When the coolant at the second set temperature reaches the thermoactuator 25, the coolant in the heat exchanger 18 may become higher than the second set temperature.
When the cooling water having a temperature higher than the second set temperature reaches the thermoactuator 25, the wax further expands. As the wax expands, the rod 55 moves forward beyond a predetermined range. So-called overlift occurs.

  As shown in FIG. 4B, when an overlift occurs, the tip 32 of the V-shaped valve 29 moves to the pocket portion 33. The shape of the pocket portion 33 is a shape along the locus of the tip 32 of the V-shaped valve 29. For this reason, the overlift of the thermoactuator is absorbed while the first passage 45 is kept closed.

  As shown in FIG. 5A, the thermoactuator 113 according to the comparative example is provided with an absorption spring 118 for absorbing overlift.

  On the other hand, the thermoactuator 25 according to the embodiment shown in (b) absorbs the overlift by the pocket portion (FIG. 4, reference numeral 33) provided in the first passage (FIG. 4, reference numeral 45). For this reason, it is not necessary to use an absorption spring for the thermoactuator 25. The thermoactuator 25 can be reduced in size by α because the absorption spring is not disposed.

In addition, the following can be said.
Returning to FIG. 2, the pocket portion 33 is provided on the downstream side of the introduction port 11 through which the exhaust gas is introduced in a side view. That is, only the thermoactuator is reduced in size without increasing the size around the inlet 11. By reducing only the thermoactuator, the exhaust heat recovery apparatus 10 as a whole can be reduced in size.

The exhaust heat recovery apparatus according to the present invention uses a V-shaped valve in the embodiment, but may have other shapes such as a linear type.
However, when it is V-shaped, the valve can be arranged in a compact manner, contributing to further downsizing of the exhaust heat recovery device.

  The exhaust heat recovery device of the present invention is suitable for an exhaust system of a vehicle.

  DESCRIPTION OF SYMBOLS 10 ... Waste heat recovery apparatus, 11 ... Introduction port, 18 ... Heat exchanger, 25 ... Thermoactuator, 27 ... Rotary shaft, 29 ... V-shaped valve (valve), 32 ... Tip, 33 ... Pocket part, 45 ... 1st Passage 46, second passage.

Claims (2)

A first passage provided with a heat exchanger for flowing the exhaust gas and transferring the heat of the exhaust gas to the cooling water, a second passage provided around the first passage, and the first and second A rotating shaft provided upstream of the passage, a thermoactuator connected to the rotating shaft and operating when the temperature of the cooling water exceeds the first preset temperature, and the first actuator when the first preset temperature is exceeded. In an exhaust heat recovery apparatus comprising a valve attached to the rotary shaft so as to be operated in a direction to close one passage,
When the temperature of the cooling water exceeds a second preset temperature higher than the first preset temperature, the valve of the valve is used to absorb the overlift when the thermoactuator operates over a predetermined range. A waste heat recovery apparatus, wherein a pocket portion formed in a shape along a locus of a tip while maintaining a predetermined gap is provided in the first passage.   The exhaust heat recovery apparatus according to claim 1, wherein the pocket portion is provided on a downstream side of an introduction port into which the exhaust gas is introduced in a side view.

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