JP2014101834A - Thermo-actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermo-actuator that can improve a force transmitted from a thermo-element to a rod member and can improve the responsivity of the thermo-element.SOLUTION: A thermo-actuator 21 comprises a support member 67 including a support part 67A sandwiched between mating surfaces 55a and 62a of cases 55 and 62 and supported by the cases 55 and 62 and a support part 67B that supports a thermo-element 57. The support part 67B of the support member 67 is connected to the support part 67A via a step part 67C so as to protrude toward the thermo-element 57 with respect to the support part 67A sandwiched between the mating surface 55a of the case 55 and the mating surface 62a of the case 62.

Description

  The present invention relates to a thermoactuator having a thermal expansion body that is provided in a vehicle or the like and is displaced according to the temperature of cooling water.

  2. Description of the Related Art Conventionally, an exhaust heat recovery device is known in which an open / close valve that switches an exhaust gas flow path is driven by a thermo actuator. A thermoactuator of the exhaust heat recovery apparatus is housed in a main body case that forms a cooling water passage therein, and includes a thermoelement having a thermal expansion body, and a cover case, and the thermoelement according to the displacement of the thermal expansion body. A rod member that moves along the central axis, and a biasing member that is provided around the rod member and biases the rod member toward the thermo element.

  The thermoactuator is interposed between the main body case and the thermoelement. The main body is sandwiched between the O-ring that seals the outer periphery of the thermoelement and the mating surface of the main body case and the mating surface of the cover case. It is comprised including the case and the disk-shaped support member supported by a cover case (for example, refer patent document 1).

JP 2011-231714 A

  However, in such a conventional thermoactuator, since the thermoelement is supported by the main body case and the cover case by the disc-shaped support member, the rigidity of the support member is small.

  For this reason, when the rod member is moved against the urging force of the urging member by the thermo element, the support member may be bent by a reaction force applied from the urging member to the support member via the rod member. . Therefore, there is a possibility that the thermo element is retracted to the opposite side to the rod member and the transmission force from the thermo element to the rod member is reduced.

  In addition to this, in order to increase the support force of the thermo element by the disc-shaped support member, it is necessary to support the thermo element by the support member inwardly in the central axis direction than the end of the thermo element. The force applied point that is the contact surface between the thermo element and the rod member is separated from the mating surface of the main body case and the cover case. For this reason, it is difficult to ensure the coaxiality between the thermo element and the rod member, and the rod member is bent and pushed out by the thermo element, and the transmission force from the thermo element to the rod member may be reduced.

  Furthermore, since the thermo element is supported by the main body case by the O-ring, the portion of the thermo element that contacts the cooling water is limited by the O-ring, and the contact area between the thermo element and the cooling water is reduced. For this reason, there exists a possibility that the responsiveness of a thermo element may fall.

  The present invention has been made to solve the conventional problems as described above, and can improve the transmission force from the thermo element to the rod member and improve the responsiveness of the thermo element. An object is to provide an actuator.

  In order to achieve the above object, the exhaust heat recovery apparatus according to the present invention includes (1) a thermo element having a thermal expansion body that expands and contracts according to the temperature of cooling water, and the thermo element facing the thermo element. A rod member that moves along the central axis in response to expansion and contraction of the thermal expansion body, a biasing member that biases the rod member toward the thermo element, and the thermostat A first case that houses an element and in which a cooling water passage through which the cooling water flows is formed; and is interposed between the first case and the thermo element; and an outer peripheral portion of the thermo element The rod member and the biasing portion, the holding member holding the seal member for sealing the seal member, and the second mating surface facing the first mating surface of the first case. A first case that accommodates the first case, and the first support portion and the thermoelement that are sandwiched between the first case and the second case and are supported by the first case and the second case A support member having a second support part for supporting the first support part, and the second support part of the support member via a step part so as to protrude from the first support part toward the thermo element. It is comprised from what is connected with the said 1st support part.

  In this thermoactuator, the second support portion of the support member faces the thermo element from the first support portion sandwiched between the first mating surface of the first case and the second mating surface of the second case. Since the first support portion is connected via the step portion so as to protrude, the rigidity of the support member can be increased by the step portion.

  For this reason, when the rod member is moved by the thermo element, it is possible to prevent the support member from being bent by a reaction force applied from the rod member to the thermo element. Therefore, it is possible to prevent the thermo element from moving backward in the direction opposite to the rod member, and it is possible to improve the transmission force from the thermo element to the rod member.

  Further, since the second support portion protrudes from the first support portion toward the thermo element, the thermo element is supported by the second support portion inward in the central axis direction from the end portion of the thermo element. Can do. For this reason, it is possible to shorten the distance from the first support portion to the contact surface of the thermo element and the rod member (that is, the force application point) while improving the support force of the thermo element.

  Therefore, the coaxiality between the thermo element and the rod member can be easily ensured when the thermo element and the rod member are assembled to the first case and the second case, respectively. As a result, the rod member is not bent and pushed out by the thermo element, and the transmission force from the thermo element to the rod member can be improved.

  Moreover, since the 2nd support part can be located in the thermo element side rather than the 1st support part by the level | step-difference part, the protrusion amount of the thermo element from a holding member can be increased to the cooling water side. For this reason, the contact area of a thermo element and cooling water can be increased, and the responsiveness of a thermo element can be improved.

  In the thermoactuator described in the above (1), (2) the thermo element is provided in the housing so as to abut on the housing for housing the thermal expansion body and the rod member. Correspondingly, it has a plunger whose amount of protrusion from the housing is variable.

  In this thermoactuator, the distance from the first support portion to the force applied points of the plunger and the rod member can be made shorter than when a conventional flat support member is used. For this reason, when the thermo element and the rod member are assembled to the first case and the second case, the coaxiality between the plunger and the rod member can be easily ensured.

  In the thermoactuator described in the above (1) or (2), (3) the thermoactuator is mounted on an exhaust heat recovery device, and the exhaust heat recovery device is disposed at an exhaust passage portion through which exhaust gas flows and a branch position. A heat receiving passage portion branched from the exhaust passage portion and performing heat exchange between the exhaust gas and the cooling water, and provided in the exhaust passage portion so as to be located downstream of the branch position, An opening / closing valve that switches to either the exhaust passage portion or the heat receiving passage portion is included, and the actuator is configured to drive the opening / closing valve.

  This thermoactuator is mounted on the exhaust heat recovery device and is configured to drive the open / close valve. Since the thermoactuator can improve the response of the thermoelement, the response of expansion and contraction of the thermal expansion body is improved according to the set temperature of the cooling water for expanding and contracting the thermal expansion body. be able to.

  For this reason, the thermo-actuator can open and close the open / close valve at an optimal timing according to the cooling water temperature.For example, when the cooling water temperature is low, the thermo-actuator is positioned at the position where the exhaust gas is circulated through the heat receiving passage. By switching the open / close valve, heat exchange can be performed between the exhaust gas flowing through the heat receiving passage and the cooling water. For this reason, the temperature of the cooling water can be raised by the heat of the exhaust gas.

  Further, for example, when the cooling water temperature is high, the exhaust gas can be flowed to the exhaust passage portion by switching the open / close valve to a position where the exhaust gas is circulated to the exhaust passage portion by the thermo actuator. It is possible to prevent heat exchange with the cooling water. For this reason, it is possible to prevent the cooling water from being excessively heated by the heat of the exhaust gas.

  In the thermoactuator described in the above (2) and (3), (4) the heat receiving passage portion has a flow pipe through which exhaust gas flows, a cooling water pipe through which cooling water flows, and a high temperature section facing the flow pipe. In addition, a low-temperature portion is opposed to the cooling water pipe, and a thermoelectric conversion module that generates power according to a temperature difference between the high-temperature portion and the low-temperature portion is configured.

  This thermoactuator is mounted on an exhaust heat recovery device having a thermoelectric conversion module and is configured to drive an on-off valve. Since the thermoactuator can improve the response of the thermoelement, the response of expansion and contraction of the thermal expansion body is improved according to the set temperature of the cooling water for expanding and contracting the thermal expansion body. be able to.

  For this reason, the thermo-actuator can open and close the open / close valve at an optimal timing according to the cooling water temperature.For example, when the cooling water temperature is low, the thermo-actuator is positioned at the position where the exhaust gas is circulated through the heat receiving passage. By switching the open / close valve, power generation can be performed according to the temperature difference between the exhaust gas flowing through the flow pipe and the cooling water flowing through the cooling water pipe.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to improve the transmission force from a thermo element to a rod member, the thermo actuator which can improve the responsiveness of a thermo element can be provided.

1 is a diagram illustrating an embodiment of an exhaust heat recovery apparatus according to the present invention, and is a schematic configuration diagram of a vehicle including the exhaust heat recovery apparatus. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is a top view of a waste heat recovery apparatus. It is a figure which shows one Embodiment of the exhaust heat recovery apparatus which concerns on this invention, and is a front view of an exhaust heat recovery apparatus. It is a figure which shows one Embodiment of the exhaust heat recovery apparatus which concerns on this invention, and is a perspective view of an exhaust heat recovery apparatus. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is AA direction arrow sectional drawing of FIG. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is BB direction arrow sectional drawing of FIG. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is an external view of a thermoelectric conversion module. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is CC sectional view taken on the line of FIG. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is DD sectional view taken on the line of FIG. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is a figure which shows the positional relationship of a cam and a rod member when a cam is displaced. It is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention, and is sectional drawing of the actuator provided with the flat support member used for the comparison.

  Hereinafter, embodiments of an exhaust heat recovery apparatus according to the present invention will be described with reference to the drawings. In this embodiment, the case where the exhaust heat recovery device is applied to a water-cooled multi-cylinder internal combustion engine mounted on a vehicle such as an automobile, for example, a four-cycle gasoline engine (hereinafter simply referred to as an engine) will be described. ing. The engine is not limited to a gasoline engine.

FIGS. 1-11 is a figure which shows one Embodiment of the waste heat recovery apparatus which concerns on this invention.
First, the configuration will be described.
As shown in FIG. 1, an engine 1 as an internal combustion engine mounted on a vehicle such as an automobile is formed by mixing air supplied from an intake system and fuel supplied from a fuel supply system at an appropriate air-fuel ratio. After the air-fuel mixture is supplied to the combustion chamber and combusted, the exhaust gas generated with this combustion is discharged from the exhaust system to the atmosphere.

  The exhaust system includes an exhaust manifold 2 attached to the engine 1 and an exhaust pipe 4 connected to the exhaust manifold 2 via a spherical joint 3. The exhaust manifold 2 and the exhaust pipe 4 An exhaust passage is formed.

The spherical joint 3 allows moderate swinging of the exhaust manifold 2 and the exhaust pipe 4 and functions so as not to transmit the vibration and movement of the engine 1 to the exhaust pipe 4 or to attenuate and transmit them.
Two catalysts 5 and 6 are installed in series on the exhaust pipe 4, and the exhaust gas is purified by the catalysts 5 and 6.

  Among the catalysts 5 and 6, the catalyst 5 installed upstream in the exhaust gas exhaust direction in the exhaust pipe 4 is a so-called start catalyst (S / C). The catalyst 6 installed downstream in the exhaust direction is a so-called main catalyst (M / C) or underfloor catalyst (U / F).

  These catalysts 5 and 6 are constituted by, for example, a three-way catalyst. This three-way catalyst exhibits a purifying action in which carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) are collectively changed to harmless components by a chemical reaction.

  A water jacket is formed inside the engine 1, and the water jacket is filled with a coolant called long life coolant (LLC) (hereinafter simply referred to as coolant).

The cooling water is led out from the outlet pipe 8 attached to the engine 1 and then supplied to the radiator 7, and is returned from the radiator 7 to the engine 1 through the cooling water reflux pipe 9.
The radiator 7 cools the cooling water circulated by the water pump 10 by heat exchange with the outside air.

Further, a bypass pipe 12 is connected to the reflux pipe 9, and a thermostat 11 is interposed between the bypass pipe 12 and the reflux pipe 9. The amount of cooling water flowing through the pipe 12 is adjusted.
For example, during the warm-up operation of the engine 1, the amount of cooling water on the bypass pipe 12 side is increased to promote warm-up.

  A heater pipe 13 is connected to the bypass pipe 12, and a heater core 14 is provided in the middle of the heater pipe 13. The heater core 14 is a heat source for heating the passenger compartment using the heat of the cooling water.

  The air heated by the heater core 14 is introduced into the vehicle interior by the blower fan 15. A heater unit 16 is configured by the heater core 14 and the blower fan 15.

  The heater pipe 13 is provided with an upstream pipe 18A for supplying cooling water to an exhaust heat recovery device 17 described later. Between the exhaust heat recovery device 17 and the reflux pipe 9, the exhaust heat recovery device 17 The reflux pipe 9 is provided with a downstream pipe 18B for discharging cooling water.

  For this reason, when the exhaust heat recovery operation is performed in the exhaust heat recovery device 17 (details of this exhaust heat recovery operation will be described later), the cooling water flowing through the downstream side pipe 18B passes through the upstream side pipe 18A. It becomes higher than the temperature of the flowing cooling water.

  On the other hand, an exhaust heat recovery device 17 is provided in the exhaust system of the engine 1, and this exhaust heat recovery device 17 recovers the heat of the exhaust gas discharged from the engine 1 and exchanges heat with the cooling water. Thus, the cooling water is heated.

  As shown in FIGS. 1 to 4, the exhaust heat recovery device 17 includes an exhaust pipe portion 19 constituting an exhaust passage portion, an exhaust heat recovery device 20 constituting a heat receiving passage portion, a thermo actuator 21, an upstream side pipe 18 </ b> A, and a downstream side. The side pipe 18B is included.

  As shown in FIGS. 1 and 5, the upstream end of the exhaust pipe portion 19 is connected to the exhaust pipe 4, and an exhaust passage 22 into which exhaust gas is introduced from the exhaust pipe 4 is provided inside the exhaust pipe portion 19. Is formed. The downstream end of the exhaust pipe portion 19 is connected to the tail pipe 23, and the exhaust gas introduced into the exhaust passage 22 is discharged to the tail pipe 23.

  For this reason, the exhaust gas discharged from the engine 1 to the exhaust passage 22 through the exhaust pipe 4 is discharged to the tail pipe 23 through the exhaust passage 22 and then discharged from the tail pipe 23 to the outside air.

  The exhaust heat recovery device 20 includes an exhaust heat recovery pipe 24. The exhaust heat recovery pipe 24 is installed above the exhaust pipe portion 19, and a heat receiving passage is provided inside the exhaust heat recovery pipe 24. 25 is formed.

  A communication hole 26 is formed on the upstream side of the exhaust pipe portion 19, and the upstream side of the exhaust passage 22 and the upstream side of the heat receiving passage 25 communicate with each other via the communication hole 26. That is, the communication hole 26 is formed at a branch position between the exhaust pipe portion 19 and the exhaust heat recovery device 20. A communication hole 27 is formed on the downstream side of the exhaust pipe portion 19, and the downstream side of the exhaust passage 22 and the downstream side of the heat receiving passage 25 communicate with each other via the communication hole 27.

  As shown in FIGS. 5 and 6, the exhaust heat recovery pipe 24 is provided with a plurality of flow pipes 28 and 29. The insides of the flow pipes 28 and 29 communicate with the upstream side and the downstream side of the heat receiving passage 25, and exhaust gas is introduced into the flow pipes 28 and 29.

  Further, the upstream side and the downstream side of the flow pipes 28 and 29 are respectively attached to plates 30 and 31, and the flow pipes 28 and 29 are supported by the plates 30 and 31 so as to be separated in the vertical direction.

  Further, the cooling water pipe 36 is constituted by the plates 30 and 31 and the upper part 24a and the lower part 24b of the exhaust heat recovery pipe 24, and the space surrounded by the plates 30 and 31 and the upper part 24a and the lower part 24b of the exhaust heat recovery pipe 24 is A cooling water passage 37 of the cooling water pipe 36 is configured.

Further, a comb-shaped heat transfer member 38 is provided inside the flow pipes 28 and 29. The heat transfer member 38 is bent along the width direction of the flow pipes 28 and 29 (left and right direction in FIG. 6) and extends in the longitudinal direction of the flow pipes 28 and 29 (left and right direction in FIG. 5). The bent portions at the upper and lower ends are in contact with the inner peripheral upper surface and the inner peripheral lower surface of the flow pipes 28 and 29.
For this reason, the heat of the exhaust gas flowing through the flow pipes 28 and 29 is efficiently transmitted to the flow pipes 28 and 29 through the heat transfer member 38.

  An upstream pipe 18A and a downstream pipe 18B are connected to the side surface of the exhaust heat recovery pipe 24, and cooling water is introduced into the cooling water passage 37 of the cooling water pipe 36 from the upstream pipe 18A. ing. The cooling water introduced into the cooling water passage 37 flows through the cooling water passage 37 and is discharged from the downstream pipe 18B.

  Outer pipes 32 and 33 are provided outside the circulation pipes 28 and 29, and a space between the circulation pipes 28 and 29 and the outer pipes 32 and 33 is a sealed space in which the thermoelectric conversion module 41 is accommodated. Module chambers 34 and 35 are defined.

  As shown in FIG. 7, the thermoelectric conversion module 41 has a temperature difference due to the Seebeck effect between the heat receiving substrate 42 made of insulating ceramics constituting the high temperature portion and the heat radiating substrate 43 made of insulating ceramics constituting the low temperature portion. A plurality of N-type thermoelectric conversion elements 44 and P-type thermoelectric conversion elements 45 that generate the corresponding electromotive force are installed, and the N-type thermoelectric conversion elements 44 and the P-type thermoelectric conversion elements 45 are alternately arranged via the electrodes 46a and 46b. Connected in series. Further, the adjacent thermoelectric conversion modules 41 are electrically connected via the wiring 47.

  In this thermoelectric conversion module 41, the heat receiving substrate 42 faces the flow tubes 28, 29 and contacts the flow tubes 28, 29, and the heat dissipation substrate 43 faces the outer tubes 32, 33 and contacts the outer tubes 32, 33. It is installed in parallel with the exhaust gas exhaust direction. 5 and 6, the thermoelectric conversion module 41 shown in FIG. 7 is simplified.

  The thermoelectric conversion module 41 supplies (charges) generated power to the auxiliary battery via the cable 48 by generating power according to the temperature difference between the heat receiving substrate 42 and the heat radiating substrate 43. .

  As shown in FIG. 5, an opening / closing valve 49 is provided in the exhaust pipe portion 19, and this opening / closing valve 49 opens and closes a cylindrical throttle portion 19 a provided in the exhaust pipe portion 19. The flow path of the exhaust gas introduced into the heat receiving passage 25 is switched to either the heat receiving passage 25 or the exhaust passage 22 of the exhaust heat recovery device 20.

  The opening / closing valve 49 is provided integrally with the shaft member 50 supported by the exhaust pipe portion 19, and the opening / closing valve 49 rotates the shaft member 50 with respect to the exhaust pipe portion 19, thereby restricting the throttle portion 19 a. Open and close.

  As shown in FIG. 8, one end portion of the shaft member 50 protrudes laterally from the exhaust pipe portion 19 and is provided outside the exhaust pipe portion 19. A cam holding member 51 is connected to one end of the shaft member 50, and the cam holding member 51 has a cam 52 shown in FIG. 10, and the cam 52 is rotationally driven by the thermoactuator 21.

  Further, a coil spring 53 is provided on the outer peripheral portion of one end portion of the shaft member 50, and one end portion of the coil spring 53 is fixed to a spring housing case 54 fixed to the exhaust pipe portion 19. The other end of the coil spring 53 is fixed to the cam holding member 51.

The coil spring 53 urges the opening / closing valve 49 so that the opening / closing valve 49 is located at a closing position where the opening / closing valve 49 is closed, and the initial position of the opening / closing valve 49 is a position where the opening / closing valve 49 is closed. Is set to
The thermoactuator 21 is provided in the middle of the upstream pipe 18A, and the thermoactuator 21 is installed on the side of the exhaust pipe portion 19 as shown in FIGS.

  8 and 9, the thermoactuator 21 includes a cylindrical case 55 as a first case that is provided in the middle of the upstream pipe 18A and constitutes a part of the upstream pipe 18A. A cooling water passage 56 is formed inside the case 55, and the cooling water flows through the cooling water passage 56 through the upstream side pipe 18 </ b> A.

  A thermo element 57 is accommodated inside the case 55, and the thermo element 57 includes a housing 58 containing a thermal expansion body such as thermo wax that expands and contracts according to the temperature of the cooling water.

  The housing 58 is liquid-tightly attached to the case 55 via a guide member 60 that holds an O-ring 59 that seals the outer peripheral portion of the housing 58. That is, the guide member 60 is interposed between the case 55 and the housing 58. In the present embodiment, the O-ring 59 constitutes a seal member, and the guide member 60 constitutes a holding member.

  Further, a rod member 61 is provided on the central axis O of the thermo element 57, that is, on the central axis O of the housing 58 so as to face the thermo element 57. The rod member 61 is used as a second case. It is accommodated in a cylindrical case 62.

  The housing 58 is provided with a plunger 63, and the tip of the plunger 63 is in contact with the rod member 61. The plunger 63 is configured such that the amount of protrusion from the housing 58 is variable according to the displacement of the thermal expansion body in the housing 58.

A coil spring 64 as a biasing member is accommodated in the case 62 so as to surround the rod member 61. One end of the coil spring 64 abuts on a flange 61 a formed on one end of the rod member 61, and the other end of the coil spring 64 abuts on the end of the case 62 via the spring seat 65. The rod member 61 is urged toward the thermo element 57 side.
Further, the other end portion of the rod member 61 protrudes outward from the case 62, and a pressing portion 61 b is provided on the other end portion of the rod member 61.

  In the thermoactuator 21 of the present embodiment, when the temperature of the cooling water flowing through the cooling water passage 56 through the upstream pipe 18A is lower than a predetermined temperature, the thermal expansion body of the thermo element 57 contracts, and the rod member 61 becomes a coil spring. 8 is moved to the left in FIG. 8 along the central axis O. When the rod member 61 moves to the left in FIG. 8, the shaft member 50 rotates in the clockwise direction by the urging force of the coil spring 53 and moves the open / close valve 49 to the closed position.

  Further, when the temperature of the cooling water flowing through the cooling water passage 56 through the upstream side pipe 18A becomes equal to or higher than a predetermined temperature, the thermal expansion body of the thermo element 57 expands, and the protruding amount of the plunger 63 with respect to the housing 58 increases, so that the plunger 63 The rod member 61 is pressed. When the rod member 61 is pressed by the plunger 63, it moves to the right in FIG. 8 along the central axis O.

  When the rod member 61 moves rightward in FIG. 8, the pressing portion 61 b attached to the tip of the rod member 61 presses the cam 52. When the pressing portion 61b presses the cam 52, the shaft member 50 rotates counterclockwise against the urging force of the coil spring 53, whereby the on-off valve 49 moves from the closed position to the open position, and the throttle portion 19a. Is released.

  On the other hand, the flange 55A of the case 55 and the flange 62A of the case 62 are fastened to the bracket 19b formed on the exhaust pipe portion 19 by bolts 66a and 66b (see FIGS. 3 and 4). It is attached to the exhaust pipe part 19 via a bracket 24c.

  The flange 55A of the case 55 and a part of the flange 62A of the case 62 are directly fastened by bolts 66c. The thermo element 57 is attached to the cases 55 and 62 by a support member 67.

  The flange 55A includes a mating surface 55a as a first mating surface, and the facing surface of the flange 62A facing the flange 55A includes a mating surface 62a as a second mating surface. The support member 67 includes an annular support portion 67A as a first support portion fastened to the flanges 55A and 62A by bolts 66a and 66b so as to be sandwiched between the mating surfaces 55a and 62a.

  Further, the support member 67 includes an annular support portion 67B as a second support portion for supporting the housing 58 of the thermo element 57. The support portion 67B faces the thermo element 57 with respect to the support portion 67A. Are connected to the support portion 67A through the stepped portion 67C.

  The stepped portion 67C is formed by being bent into an L-shaped cross section, and an annular portion 67a extending in the same direction as the central axis O of the housing 58 and a disc extending in a direction perpendicular to the central axis O of the housing 58. Part 67b. For this reason, a step is formed between the support portion 67A and the disc portion 67b with the annular portion 67a interposed therebetween.

  Further, the support portion 67B extends along the central axis O of the housing 58 from the disc portion 67b.

Next, the operation will be described.
When the engine 1 is cold started, the catalysts 5 and 6 and the cooling water of the engine 1 are all at a low temperature (about the outside temperature).

When the engine 1 is started from this state, the exhaust gas is discharged from the engine 1 to the exhaust pipe 4 through the exhaust manifold 2 with the start of the engine 1, and the two catalysts 5, 6 are exhausted by the exhaust gas. The temperature will rise.
Further, the cooling water is returned to the engine 1 through the bypass pipe 12 without passing through the radiator 7, so that the warm-up operation is performed.

  When the engine 1 is cold-started, for example, the temperature of the cooling water is low, so that the open / close valve 49 is closed. Therefore, the exhaust gas introduced from the exhaust pipe 4 into the exhaust passage 22 of the exhaust pipe portion 19 is introduced into the heat receiving passage 25 of the exhaust heat recovery pipe 24 through the communication hole 26.

The cooling water flowing through the upstream side pipe 18 </ b> A is introduced into the cooling water pipe 36 through the cooling water passage 56 of the case 55 of the thermoactuator 21. For this reason, the temperature of the cooling water flowing through the cooling water pipe 36 is raised by the exhaust gas flowing through the flow pipes 28 and 29, and the engine 1 is warmed up.
Further, the exhaust gas introduced into the flow pipes 28 and 29 is introduced into the exhaust passage 22 of the exhaust pipe portion 19 through the communication hole 27 and is discharged to the outside air through the tail pipe 23.

  Since the high temperature exhaust gas flowing through the flow pipe 28 acts on the heat receiving substrate 42 of the thermoelectric conversion module 41 and the low temperature cooling water flowing through the cooling water pipe 36 acts on the heat radiating substrate 43, the temperature between the heat receiving substrate 42 and the heat radiating substrate 43. Due to the difference, the thermoelectric conversion module 41 generates power.

  Further, since the temperature of the cooling water introduced from the engine 1 to the outlet pipe 8 becomes high after the warm-up of the engine 1 is finished, the communication between the bypass pipe 12 and the reflux pipe 9 is cut off by operating the thermostat 11. Therefore, the cooling water led out from the engine 1 through the lead-out pipe 8 is led out to the reflux pipe 9 through the radiator 7. For this reason, low-temperature cooling water is supplied to the engine 1, and the cooling performance of the engine 1 can be enhanced.

  Further, when the temperature of the cooling water introduced from the outlet pipe 8 to the upstream side pipe 18A reaches a predetermined temperature, the thermal expansion body of the thermo element 57 expands and presses the rod member 61 to the right in FIG. The pressing part 61 b presses the cam 52.

  At this time, when the shaft member 50 rotates counterclockwise against the urging force of the coil spring 53, the open / close valve 49 moves from the closed position to the open position to open the throttle portion 19a. Therefore, the exhaust gas introduced from the exhaust pipe 4 to the exhaust pipe portion 19 is discharged to the tail pipe 23 through the exhaust passage 22 and is discharged to the outside air through the tail pipe 23. Here, the predetermined temperature may be a warm-up temperature or a temperature equal to or higher than the warm-up temperature, and is not particularly limited.

  Further, in the thermoactuator 21 of the present embodiment, the support portion 67B of the support member 67 faces the thermoelement 57 with respect to the support portion 67A sandwiched between the mating surface 55a of the case 55 and the mating surface 62a of the case 62. It is connected to the supporting portion 67A through the stepped portion 67C so as to protrude. For this reason, the rigidity of the support member 67 can be increased by the stepped portion 67C.

  Specifically, as shown in FIG. 11, when the support member 71 is formed in a disc shape, the rigidity of the support member 71 is reduced. When the thermoelement having the disk-shaped support member 71 is used, the thermal expansion body is expanded by the cooling water having a predetermined temperature or higher, and the rod member 61 is moved to the left in FIG. Then, the support member 71 is bent by a reaction force applied from the rod member 61 to the thermo element 57.

On the other hand, since the thermoactuator 21 of the present embodiment can increase the rigidity of the support member 67 by the stepped portion 67C, the reaction force applied from the coil spring 64 to the support member 67 via the rod member 61. Therefore, it is possible to prevent the support member 67 from being bent.
Therefore, it is possible to prevent the thermo element 57 from retreating in the opposite direction to the rod member 61, and to improve the transmission force from the thermo element 57 to the rod member 61.

  Further, in the thermoactuator 21 of the present embodiment, since the support portion 67B protrudes toward the thermoelement 57 with respect to the support portion 67A, as shown in FIG. 9, the mating surfaces 55a, 62a of the cases 55, 62 The distance L2 from the contact point of the thermo element 57 and the rod member 61, that is, the applied point that is the contact surface of the plunger 63 and the rod member 61, can be shortened.

  Specifically, as shown in FIG. 11, in the case where a disk-shaped support member 71 is used, the support member 71 uses a support member 71 to make the housing more than the end of the housing 58 in order to increase the support force of the thermoelement 57. It is necessary to support 58 inward in the direction of the central axis O.

  If it does in this way, the housing 58 will protrude to the rod member 61 side with respect to the guide member 60, and the distance L1 from the mating surfaces 55a and 62a of the cases 55 and 62 to the force application point of the plunger 63 and the rod member 61 will become long. .

  As a result, it is difficult to ensure the coaxiality between the plunger 63 and the rod member 61, the rod member 61 is bent and pushed out by the plunger 63, and the transmission force from the thermo element 57 to the rod member 61 is reduced.

  On the other hand, in the thermo element 57 of the present embodiment, the support portion 67B protrudes toward the thermo element 57 with respect to the support portion 67A. The distance from the mating surfaces 55a, 62a of the cases 55, 62 to the force points of the plunger 63 and the rod member 61 can be reduced while the housing 58 is supported by the support portion 67B to improve the support force of the thermo element. it can.

  For this reason, when the thermo element 57 and the rod member 61 are assembled to the cases 55 and 62, the coaxiality between the thermo element 57 and the rod member 61 can be easily ensured. Therefore, the rod member 61 can be prevented from being bent and pushed out by the plunger 63, and the transmission force from the thermo element 57 to the rod member 61 can be improved.

Further, as shown in FIG. 11, when the thermo element 57 is held by the flat support member 71, the protrusion amount L3 of the housing 58 from the guide member 60 cannot be increased, and the housing 58 and the cooling water The contact area with is reduced.
In contrast, in the thermoactuator 21 of the present embodiment, the support portion 67B can be positioned closer to the thermoelement 57 than the support portion 67A by the stepped portion 67C. L4 can be increased on the cooling water side.

  For this reason, the contact area of the housing 58 and cooling water can be increased, and the responsiveness of the thermal expansion body of the thermoelement 57 can be improved. That is, the response of expansion and contraction of the thermal expansion body can be improved according to the set temperature of the cooling water for expanding and contracting the thermal expansion body.

  Therefore, the opening / closing valve 49 can be opened and closed by the thermoactuator 21 at an optimum timing according to the cooling water temperature. When the cooling water temperature is low, the thermoactuator 21 is placed at a position where the exhaust gas is circulated through the heat receiving passage 25. The on-off valve 49 can be switched. As a result, the temperature of the cooling water can be raised by the heat of the exhaust gas, and power generation can be performed by the thermoelectric conversion module 41.

  Further, when the cooling water temperature is high, by switching the open / close valve 49 to a position where the exhaust gas flows through the exhaust passage 22 by the thermoactuator 21, the exhaust gas can flow into the exhaust passage 22, It is possible to prevent heat exchange with the cooling water. As a result, it is possible to prevent the cooling water from being excessively heated by the heat of the exhaust gas, and it is possible to prevent the cooling performance of the engine 1 from deteriorating and the engine 1 from being overheated.

  As described above, the exhaust heat recovery apparatus according to the present invention has an effect that the transmission force from the thermo element to the rod member can be improved and the response of the thermo element can be improved. And is useful as a thermoactuator having a thermal expansion body that is displaced according to the temperature of the cooling water.

  DESCRIPTION OF SYMBOLS 17 ... Waste heat recovery apparatus, 19 ... Exhaust pipe part (exhaust passage part), 20 ... Exhaust heat recovery device (heat receiving path part), 21 ... Thermo actuator, 36 ... Cooling water pipe, 41 ... Thermoelectric conversion module, 42 ... Heat receiving board (High temperature part), 43 ... heat dissipation substrate (low temperature part), 49 ... open / close valve, 55 ... case (first case), 55a ... mating surface (first mating surface), 57 ... thermo element, 58 ... housing, 59 ... O-ring (seal member), 60 ... guide member (holding member), 61 ... rod member, 62 ... case (second case), 62a ... mating surface (second mating surface), 63 ... plunger, 64 ... Coil spring (biasing member), 67 ... Support member, 67A ... Support part (first support part), 67B ... Support part (second support part), 67C ... Step part

Claims (4)

A thermo element having a thermal expansion body that expands and contracts according to the temperature of the cooling water;
A rod member which is provided on the center axis of the thermo element facing the thermo element and moves along the center axis in accordance with expansion and contraction of the thermal expansion body;
A biasing member that biases the rod member toward the thermo element;
A first case in which a cooling water passage is formed, in which the cooling element is accommodated while accommodating the thermo element;
A holding member that is interposed between the first case and the thermo element and holds a seal member that seals an outer peripheral portion of the thermo element;
A second case having a second mating surface facing the first mating surface of the first case, and housing the rod member and the biasing member;
A first support portion sandwiched between the first mating surface and the second mating surface and supported by the first case and the second case; and a second support portion for supporting the thermo-element. A support member having,
The second support portion of the support member is connected to the first support portion through a step portion so as to protrude from the first support portion toward the thermo element. Actuator.   The thermo element includes a housing that accommodates the thermal expansion body, a plunger that is provided in the housing so as to abut against the rod member, and whose protrusion amount from the housing is variable according to the displacement of the thermal expansion body; The thermoactuator according to claim 1, comprising: The thermo actuator is mounted on an exhaust heat recovery device,
The exhaust heat recovery device includes an exhaust passage portion through which exhaust gas flows and a heat receiving passage portion that is branched from the exhaust passage portion at a branch position and exchanges heat between the exhaust gas and cooling water, and a downstream of the branch position. An opening / closing valve that is provided in the exhaust passage portion so as to be located at one of the exhaust passage portion and the heat receiving passage portion.
The thermoactuator according to claim 1 or 2, wherein the actuator drives the open / close valve.   The heat receiving passage section includes a flow pipe through which exhaust gas flows, a cooling water pipe through which cooling water flows, a high temperature section facing the flow pipe, a low temperature section facing the cooling water pipe, and the high temperature section and the The exhaust heat recovery apparatus according to claim 2, further comprising a thermoelectric conversion module that generates electric power according to a temperature difference from the low temperature part.

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