JP7240967B2 - Exhaust heat recovery equipment for vehicles - Google Patents

Description

The present invention relates to an exhaust heat recovery device for a vehicle.

In a vehicle, an engine burns a mixture of air and fuel, and the exhaust gas after combustion is discharged from an exhaust pipe.
In such vehicles, a device for recovering the exhaust heat of the exhaust gas, which has reached a high temperature and a high pressure due to combustion in the engine, is sometimes used.
In the vehicle exhaust heat recovery device of Patent Document 1 or Patent Document 2, a branch pipe is provided in an exhaust pipe for discharging exhaust gas from a vehicle engine, and a heat exchanger for exhaust heat recovery is provided in the branch pipe. The heat exchanger recovers exhaust heat by heat exchange from the exhaust gas flowing through the branch pipe.

JP 2006-312884 A JP 2008-133783 A JP 2009-013838 A

However, when a branch pipe is provided in the exhaust pipe, it is necessary to newly secure a large space in the vehicle for providing the branch pipe. Moreover, at least the branch pipes add extra weight to the vehicle compared to simply providing a heat exchanger.

Therefore, as in Patent Document 3, it is conceivable to provide a rotatable heat exchanger in an exhaust pipe that discharges exhaust gas from a vehicle engine.
However, the heat exchanger of Patent Document 3 is supported by a rotating shaft provided in the center of the exhaust pipe.
In this case, even when the exhaust heat is not used, the heat exchanger is positioned in the center of the exhaust pipe so as to lie along the direction in which the exhaust pipe extends, and exists in the center of the flow path of the exhaust gas in the exhaust pipe. do. The flow of exhaust gases in the exhaust pipe is always impeded by heat exchangers. In order to obtain a predetermined flow rate, the exhaust pipe must be formed with a diameter larger than that originally required for exhaust, taking into account the obstruction. It may affect the overall design of the vehicle, including the exhaust pipes, for exhaust heat recovery.
Moreover, the heat exchanger of Patent Document 3 is always exposed to high-temperature exhaust gas even when exhaust heat is not used. The heat exchanger, which is constantly exposed to high-temperature exhaust gas, may heat the heat medium flowing through the heat exchanger to a higher temperature than necessary.

Thus, there is a need to improve exhaust heat recovery systems for vehicles.

A vehicle exhaust heat recovery device according to the present invention is a rotating shaft provided rotatably along the extending direction of an exhaust pipe that discharges exhaust gas from a vehicle engine at a position shifted outward from the center of the exhaust pipe. a heat exchanger having one end edge supported by the rotating shaft; and a rotary actuator rotating the heat exchanger around the rotating shaft, wherein the rotary actuator does not recover exhaust heat. In this case, the heat exchanger is tilted along the extending direction of the exhaust pipe, and when exhaust heat is to be recovered, the heat exchanger is rotated from the tilted position to stand on the exhaust pipe.

Preferably, the exhaust pipe is formed with an accommodating recess formed by projecting a part of the peripheral surface outward, and the rotating shaft extends in the accommodating recess in a direction in contact with the peripheral surface of the exhaust pipe. , and the heat exchanger is preferably housed in the housing recess in a tilted posture.

Preferably, the rotating shaft is positioned upstream of the heat exchanger in the inverted position in the housing recess.

Preferably, a heat insulating cover that covers the housing recess and an opening/closing actuator that drives the heat insulating cover to move away from the housing recess are provided, and the opening/closing actuator is closed by the heat insulation cover when exhaust heat is not recovered. When recovering exhaust heat by covering the housing recess, the heat insulating cover is preferably displaced from the housing recess.

Preferably, it has a heat insulating shutter that covers the surface of the heat exchanger, and an open/close actuator that drives the heat insulating shutter to expose the surface of the heat exchanger, and the open/close actuator recovers exhaust heat. If not, it is preferable to cover the surface of the heat exchanger with the heat insulating shutter and expose the surface of the heat insulating shutter when exhaust heat is recovered.

Another vehicle exhaust heat recovery device according to the present invention includes an opening formed in an exhaust pipe for discharging exhaust gas from a vehicle engine, and a center portion of the opening in the extending direction of the exhaust pipe. a rotating shaft provided rotatably along the extending direction of the tube; a clogging member supported by the rotating shaft so as to close the opening; a heat exchanger supported by the rotating shaft; and a rotating actuator rotating the heat exchanger around the rotating shaft. When the heat exchanger is located outside the opening and the closing member is driven to block the opening and recovers exhaust heat, the closing member is rotated while the heat exchanger is located inside the opening. Rotating drive is performed so as to close the opening.

Preferably, the heat exchanger is formed so as not to block the entire exhaust pipe when positioned within the opening.

Preferably, the rotary actuator rotates to tilt the heat exchanger when the temperature of the heat medium flowing through the heat exchanger becomes high.

Preferably, the heat exchanger is provided downstream of the catalytic device in the exhaust pipe.

In the present invention, the heat exchanger of the vehicle exhaust heat recovery device is rotatable along the extending direction of the exhaust pipe at a position shifted outward from the center of the exhaust pipe that discharges the exhaust gas of the vehicle engine. One end edge is pivotally supported by the rotating shaft provided. A rotary actuator rotates the heat exchanger around the rotary shaft.
For example, when exhaust heat is not recovered, the rotary actuator causes the heat exchanger to lie down along the extending direction of the exhaust pipe. An inverted heat exchanger is positioned so that the entire heat exchanger is shifted outward from the center of the exhaust pipe. Therefore, it is difficult for the inverted heat exchanger to cut off the flow of exhaust gas flowing through the exhaust pipe. The exhaust gas flow with the heat exchanger lying down can be in one flow, as can the upstream and downstream portions of the heat exchanger for the exhaust pipe. Exhaust gas efficiently flows through the exhaust pipe, including where the heat exchanger is located.
On the other hand, if the heat exchanger is rotatably supported by a rotation shaft that is rotatably provided at the center of the exhaust pipe, the heat exchanger can be tilted along the direction in which the exhaust pipe extends. Even if it does, the whole remains in the center of the exhaust pipe. A heat exchanger that is collapsed in the middle of the exhaust pipe splits the exhaust gas into two streams. The exhaust gases that are in one stream upstream of the heat exchanger are split in two by the heat exchanger and recombined back into one stream downstream of the heat exchanger. In this case, on the downstream side of the heat exchanger, the two opposing flows merge so that they are involved in the downstream side of the heat exchanger. A vortex is generated when two opposing flows meet. When the vortex flow is generated in the exhaust pipe, the flow of the exhaust gas along the extending direction of the exhaust pipe is obstructed, and the exhaust efficiency is lowered. Moreover, since the exhaust efficiency is constantly reduced by the heat exchanger, in order to obtain a predetermined flow rate, the exhaust pipe must be formed with a larger diameter than in the case without the heat exchanger so as to compensate for the reduction. must. Increasing the diameter of the exhaust pipe to recover exhaust heat can also affect the overall design of the vehicle. In the present invention, it is possible to secure the flow rate of the exhaust gas in the exhaust pipe by providing the heat exchanger in the exhaust pipe without increasing the diameter of the exhaust pipe.
Further, in the present invention, the heat exchanger for exhaust heat recovery is rotatably provided inside the exhaust pipe. Therefore, in the present invention, it is not necessary to connect a branch pipe to the exhaust pipe and provide a heat exchanger in the branch pipe in order to provide a heat exchanger for exhaust heat recovery. INDUSTRIAL APPLICABILITY The exhaust heat recovery device of the present invention can preferably use the internal space of an existing exhaust pipe to minimize the space required outside the exhaust pipe, and can be provided in a small size in a vehicle.

FIG. 1 is an explanatory diagram of an automobile according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of the mechanical configuration of the exhaust heat recovery device provided in the exhaust pipe of the automobile according to the first embodiment of the present invention. 3 is an explanatory diagram of a control system of the exhaust heat recovery device of FIG. 2. FIG. FIG. 4 is a flow chart of exhaust heat recovery control by the exhaust heat recovery ECU of FIG. FIG. 5 is an explanatory diagram of a first modification of the exhaust heat recovery device according to the first embodiment. FIG. 6 is an explanatory diagram of a second modification of the exhaust heat recovery device according to the first embodiment. FIG. 7 is an explanatory diagram of the mechanical configuration of the exhaust heat recovery device provided in the exhaust pipe of the automobile according to the second embodiment of the present invention. FIG. 8 is an explanatory diagram of a modification of the exhaust heat recovery device according to the second embodiment. FIG. 9 is an explanatory diagram of the mechanical configuration of the exhaust heat recovery device provided in the exhaust pipe of the automobile according to the third embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described based on the drawings.

[First embodiment]
FIG. 1 is an explanatory diagram of an automobile 1 according to an embodiment of the present invention.
A car 1 in FIG. 1 is an example of a vehicle. An automobile 1 has an engine 2 and an exhaust pipe 3 arranged in the front part of the vehicle body. The exhaust pipe 3 extends from the front part of the vehicle body to the rear edge. An automobile 1 burns a mixture of air and fuel in an engine 2 and discharges exhaust gas after combustion to the outside through an exhaust pipe 3 . A catalyst device 4 is provided in the middle of the exhaust pipe 3 . The catalyst device 4 adsorbs or detoxifies nitrogen oxides and the like contained in the exhaust gas. If the engine 2 has multiple cylinders, a collecting pipe may be used as the exhaust pipe 3 . In this case, the exhaust gas moves from the upstream side to the downstream side in the exhaust pipe 3 while pulsating according to the exhaust gas from the plurality of cylinders of the engine 2 , and is exhausted from the exhaust pipe 3 .

By the way, such an automobile 1 may use a device for recovering exhaust heat from the exhaust gas, which has become high temperature and high pressure due to combustion in the engine 2 . In a conventional exhaust heat recovery device 10 for an automobile 1, an exhaust pipe 3 for discharging exhaust gas from an engine 2 of the automobile 1 is provided with a branch pipe, and the branch pipe is provided with a heat exchanger 12 for exhaust heat recovery. The heat exchanger 12 recovers exhaust heat by heat exchange from the exhaust gas flowing through the branch pipe. However, when a branch pipe is provided in the exhaust pipe 3, it is necessary to newly secure a large space in the automobile 1 for providing the branch pipe. Moreover, at least due to the branch pipes, the weight of the vehicle 1 is increased as compared with the case where the heat exchanger 12 is simply provided. Changing the design of the automobile 1 in order to provide the exhaust heat recovery device 10 in the automobile 1 hinders the use of the exhaust heat recovery device 10 .
Thus, the exhaust heat recovery device 10 of the automobile 1 is required to be improved.

FIG. 2 is an explanatory diagram of the mechanical configuration of the exhaust heat recovery device 10 provided in the exhaust pipe 3 of the automobile 1 according to the first embodiment of the present invention.
FIG. 2 shows a housing recess 11, a heat exchanger 12, a rotating shaft 13, and a heat insulating cover 14 as the mechanical configuration of the exhaust heat recovery device 10 provided in the exhaust pipe 3 of the automobile 1. As shown in FIG.
FIG. 2A shows a state in which the heat exchanger 12 is placed in an inverted position along the extending direction of the exhaust pipe 3 and accommodated in the accommodation recess 11 , and the accommodation recess 11 is closed by the heat insulating cover 14 .
FIG. 2(B) shows a state in which the heat insulating cover 14 is moved to open the housing recess 11, and the heat exchanger 12 is rotated from the laid down position to stand in the exhaust pipe 3. FIG.

The heat exchanger 12 is formed, for example, by folding narrow tubes in which a heat medium flows, with a gap between them, so that the overall shape of the heat exchanger 12 is generally a thin plate. A heat exchanger 12 is provided inside the exhaust pipe 3 . The heat exchanger 12 provided in the exhaust pipe 3 converts the exhaust heat of the high-temperature and high-pressure exhaust gas flowing from the upstream side to the downstream side along the extending direction of the exhaust pipe 3 into cooling water or the like flowing through the heat exchanger 12 . heat transfer medium. The heat exchanger 12 performs heat exchange by transferring the waste heat of the exhaust gas to the heat medium.
The heat medium is connected, for example, with a heat medium circulation cycle of an air conditioner of the motor vehicle 1 (not shown). In this case, the heat medium heated by the exhaust heat of the exhaust gas in the heat exchanger 12 is supplied to the heater core of the air conditioner through the circulation cycle. The heater core heats the air supplied to the interior of the automobile 1 with the exhaust heat recovered from the exhaust gas. Exhaust heat recovered from the exhaust gas can be used to heat the cabin of the automobile 1 . Exhaust heat recovered from the exhaust gas may also be used to heat the battery, for example, in conjunction with a heat medium circulation cycle that surrounds the battery of the vehicle 1 . Also, the exhaust heat recovered from the exhaust gas may be used for power generation by rotating the power generation turbine through a circulation cycle in which a heat medium is circulated between the heat exchanger 12 and the power generation turbine.

The housing recess 11 is formed in the exhaust pipe 3 by, for example, projecting outward from a portion of the peripheral surface of the substantially cylindrical exhaust pipe 3 .
The accommodation recess 11 has a substantially cubic inner shape that is one size larger than the substantially thin plate-shaped heat exchanger 12 . Thereby, as shown in FIG. 2A , the substantially thin plate-like heat exchanger 12 can be entirely housed in the housing recess 11 in a tilted posture in which it is laid down along the extending direction of the exhaust pipe 3 .
The housing recess 11 is formed at a position downstream of the catalyst device 4 in the exhaust pipe 3, as shown in FIG. Thereby, the heat exchanger 12 is provided downstream of the catalyst device 4 in the exhaust pipe 3 . The heat exchanger 12 is supplied with the exhaust gas in which temperature and pressure pulsations are reduced by the catalyst device 4 . The heat exchanger 12 is not directly exposed to the very hot, high pressure, pulsating exhaust gases exiting the engine 2 .

The rotary shaft 13 is a shaft member that is rotationally driven by a rotary actuator 17, which will be described later. The rotating shaft 13 is rotatably provided in the housing recess 11 . The rotating shaft 13 is provided at a position shifted from the center of the substantially cylindrical exhaust pipe 3 to the outer peripheral side.
The rotating shaft 13 is provided in the housing recess 11 so as to extend along a tangential direction in contact with the peripheral surface of the substantially cylindrical exhaust pipe 3 . In this case, the rotating shaft 13 is rotatably provided along the extending direction of the exhaust pipe 3 .
The rotating shaft 13 is provided at a portion on the upstream side with respect to the housing recess 11 .
A substantially thin plate-shaped heat exchanger 12 is pivotally supported by a rotary shaft 13 at one end edge on the upstream side in a tilted posture accommodated in the accommodation recess 11 . The rotating shaft 13 is positioned upstream of the heat exchanger 12 in the reclined position in the housing recess 11 . In this case, the substantially thin plate-like heat exchanger 12 in the inverted posture of FIG. Stand up toward the inside of 3. The substantially thin plate-shaped heat exchanger 12 standing up in the exhaust pipe 3 is positioned substantially entirely inside the exhaust pipe 3 as shown in FIG. 2(B). Most of the exhaust gas flowing through the exhaust pipe 3 passes through the heat exchanger 12 .

The heat insulating cover 14 has a plate shape that is slightly larger than the opening of the housing recess 11 to the exhaust pipe 3 . The heat insulating cover 14 may have a laminated structure of a base material made of the same material as the exhaust pipe 3 and a heat insulating material adhered to the surface of the base material. The heat insulating cover 14 is provided inside the exhaust pipe 3 so as to be movable between a position covering the housing recess 11 and a position shifted so as to be separated from the housing recess 11 . The heat insulating cover 14 may be curved along the peripheral surface of the exhaust pipe 3 if it is movable in the extending direction of the exhaust pipe 3, for example. The heat insulating cover 14 at the closed position shown in FIG. 2A moves along the extending direction of the exhaust pipe 3 and is removed from the housing recess 11 as shown in FIG. 2B. When the heat insulating cover 14 is in the open position shown in FIG. 2B, the substantially thin plate-shaped heat exchanger 12 that has been housed in the reclined position with respect to the housing recess 11 rotates into the upright position toward the inside of the exhaust pipe 3. become drivable.

FIG. 3 is an explanatory diagram of the control system of the exhaust heat recovery device 10 of FIG.
The control system of the exhaust heat recovery device 10 of FIG. 3 has a heat medium temperature sensor 15, a timer 16, a rotary actuator 17, an opening/closing actuator 18, and an exhaust heat recovery ECU 19 to which these are connected.

A heat medium temperature sensor 15 detects the temperature of the heat medium circulating through the heat exchanger 12 . Heat medium temperature sensor 15 is provided, for example, in the flow path of the heat medium discharged from heat exchanger 12 as shown in FIG.
The timer 16 measures elapsed time and time.
The rotary actuator 17 rotationally drives the rotary shaft 13 . As a result, the heat exchanger 12 is rotationally driven around the rotating shaft 13 and switched between the lying posture and the standing posture. The rotary actuator 17 may be, for example, a motor. The rotary actuator 17 may be capable of rotationally driving the rotary shaft 13 and holding the rotary shaft 13 by an arbitrary amount of rotation. An arbitrary ratchet mechanism or the like may be used to hold the rotating shaft 13 by an arbitrary amount of rotation.
The opening/closing actuator 18 moves and drives the heat insulation cover 14 to be displaced from the housing recess 11 . The open/close actuator 18 may be, for example, a motor that moves and drives the heat insulating cover 14 to the open position against the urging force that maintains the cover 14 at the closed position.

The exhaust heat recovery ECU 19 controls the operation or stop of each part of the exhaust heat recovery device 10 based on the detection signal of the sensor of the exhaust heat recovery device 10 or the like.
The exhaust heat recovery ECU 19 is one of a plurality of ECUs provided in the vehicle 1 to control the vehicle 1 . FIG. 3 also exemplifies an engine ECU 21, an air conditioning ECU 22, a battery management ECU 23, and a charging ECU 24. As shown in FIG. These multiple ECUs are connected by an in-vehicle network 20 provided in the automobile 1 so as to be capable of two-way communication.
For example, when the engine 2 is started in the cold winter, the engine ECU 21 notifies the air conditioning ECU 22 of the start of the engine 2 . When the air conditioning ECU 22 receives notification that the engine 2 has started and it is necessary to heat the air supplied to the passenger compartment by the heater core, the air conditioning ECU 22 circulates the heat medium that has been circulating through the engine 2 to the exhaust heat recovery device 10 to heat the air. To do this, a request for starting exhaust heat recovery is sent to the exhaust heat recovery ECU 19 . The exhaust heat recovery ECU 19 controls the open/close actuator 18 and the rotary actuator 17 to open the heat insulating cover 14 and control the heat exchanger 12 to the standing position. As a result, the air conditioning ECU 22 does not circulate the heat medium to the engine 2 which has not yet warmed up because it has just been started, but to the exhaust heat recovery device 10 which recovers the exhaust heat from the high-temperature exhaust gas combusted by the engine 2. By circulating the heat medium, the warm air warmed by the exhaust gas can be supplied to the passenger compartment before the engine 2 is warmed up.
Further, when the engine 2 warms up, the exhaust heat recovery ECU 19 controls the open/close actuator 18 and the rotation actuator 17 based on the exhaust heat recovery end request from the air conditioning ECU 22, controls the heat exchanger 12 to the tilted posture, and adjusts the heat insulating cover. 14 to the closed position. This makes it difficult for the heat medium to be heated in the exhaust heat recovery device 10 . The air conditioning ECU 22 can circulate the heat medium in the warmed engine 2 to supply warm air to the passenger compartment.

FIG. 4 is a flow chart of exhaust heat recovery control by the exhaust heat recovery ECU 19 of FIG.
The exhaust heat recovery ECU 19 repeatedly executes the exhaust heat recovery control shown in FIG.
In the exhaust heat recovery device 10, the exhaust heat recovery ECU 19 controls the heat exchanger 12 to be tilted and accommodated in the accommodation recess 11 as shown in FIG. It covers the accommodation recess 11 . Thereby, the heat exchanger 12 is stored in a state separated from the flow path of the exhaust gas in the exhaust pipe 3 . Exhaust heat of the exhaust gas in the exhaust pipe 3 is hardly transmitted to the heat exchanger 12 . The heat exchanger 12 of the exhaust heat recovery device 10 does not recover exhaust heat.

In step ST1 in FIG. 4, the exhaust heat recovery ECU 19 determines whether or not there is a request to start exhaust heat recovery by the heat exchanger 12. FIG. For example, the air conditioning ECU 22 transmits an exhaust heat recovery start request to the exhaust heat recovery ECU 19 through the in-vehicle network 20 when exhaust heat recovery becomes necessary. If there is no exhaust heat recovery start request, the exhaust heat recovery ECU 19 terminates the exhaust heat recovery control shown in FIG. When there is an exhaust heat recovery start request, the exhaust heat recovery ECU 19 advances the process to step ST2.

In step ST2, the exhaust heat recovery ECU 19 causes the open/close actuator 18 to drive the heat insulation cover 14 based on the exhaust heat recovery start request. The open/close actuator 18 shifts the heat insulating cover 14 from the closed position covering the housing recess 11 to the open position shown in FIG. 2(B).

In step ST<b>3 , the exhaust heat recovery ECU 19 rotates the heat exchanger 12 with the rotary actuator 17 . The rotary actuator 17 rotates the heat exchanger 12 from the laid down position to the upright position shown in FIG. 2(B). As a result, the heat exchanger 12 rotates to the maximum and stands on the exhaust pipe 3, efficiently transferring the exhaust heat of the exhaust gas flowing through the exhaust pipe 3 to the heat medium. The heat medium is heated by the high-temperature and high-pressure exhaust gas.

In step ST4, the exhaust heat recovery ECU 19 acquires the detected temperature of the heat medium from the heat medium temperature sensor 15, and compares the detected temperature with the upper limit temperature. The upper limit temperature may be, for example, the upper limit temperature of the operating temperature range of the heat medium. Also, the upper limit temperature may be the upper limit heat resistant temperature of the heat medium. When the detected temperature is equal to or higher than the upper limit temperature, the exhaust heat recovery ECU 19 advances the process to step ST5. When the detected temperature is lower than the upper limit temperature, the exhaust heat recovery ECU 19 advances the process to step ST7.

In step ST5, the exhaust heat recovery ECU 19 determines whether or not a predetermined post-adjustment period has elapsed after the previous adjustment in step ST6, which will be described later. The exhaust heat recovery ECU 19 may determine, based on the time measured by the timer 16, whether or not the post-adjustment period has elapsed since the previous adjustment. If the post-adjustment period is, for example, after the angle of the heat exchanger 12 is adjusted in step ST6, which will be described later, the period corresponding to the time in which the heat exchange from the exhaust gas to the heat medium can reach equilibrium in the adjusted state. good. If the post-adjustment period has elapsed, the exhaust heat recovery ECU 19 advances the process to step ST6 for readjustment. If the post-adjustment period has not elapsed, the exhaust heat recovery ECU 19 advances the process to step ST7.

In step ST6, the exhaust heat recovery ECU 19 executes control for suppressing heating of the heat medium.
For example, the exhaust heat recovery ECU 19 rotates the heat exchanger 12 by a predetermined amount using the rotary actuator 17 so as to tilt the heat medium in the exhaust pipe 3 . When the temperature of the heat medium flowing through the heat exchanger 12 becomes high, the rotary actuator 17 rotates to tilt the heat exchanger 12 . As a result, the vertical angle of the heat exchanger 12 at the exhaust pipe 3 is reduced, the amount of exhaust gas passing through the heat exchanger 12 is reduced, and the amount of heat transferred to the heat medium is reduced.
Also, when the heat exchanger 12 is knocked over a plurality of times, the heat exchanger 12 is finally accommodated in the accommodation recess 11 . The heat exchanger 12 can be accommodated in an inverted position in the accommodation recess 11 with the heat insulating cover 14 opened. If the heat medium is still heated in this state, the exhaust heat recovery ECU 19 causes the open/close actuator 18 to drive the heat insulating cover 14 to move. As a result, the accommodation recess 11 that accommodates the heat exchanger 12 in the inverted position is closed by the heat insulating cover 14 . Note that the exhaust heat recovery ECU 19 may divide the movement of the heat insulation cover 14 from the open position to the closed position into a plurality of control operations.

At step ST7, the exhaust heat recovery ECU 19 determines whether or not there is an exhaust heat recovery end request. For example, when exhaust heat recovery becomes unnecessary, the air conditioning ECU 22 transmits an exhaust heat recovery end request to the exhaust heat recovery ECU 19 through the in-vehicle network 20 . If there is no exhaust heat recovery end request, the exhaust heat recovery ECU 19 returns the process to step ST4. The exhaust heat recovery ECU 19 repeats the processing from step ST4 to step ST7 until an exhaust heat recovery end request is received. During this time, the heat exchanger 12 continues to transfer exhaust heat of the exhaust gas to the heat medium. When there is an exhaust heat recovery end request, the exhaust heat recovery ECU 19 advances the process to step ST8.

In step ST8, the exhaust heat recovery ECU 19 rotates the heat exchanger 12 by the rotating actuator 17 so as not to recover exhaust heat. The rotary actuator 17 rotationally drives the heat exchanger 12 in an inverted posture along the extending direction of the exhaust pipe 3 .
In step ST9, the exhaust heat recovery ECU 19 causes the opening/closing actuator 18 to drive the heat insulating cover 14 to move. The open/close actuator 18 moves and drives the heat insulating cover 14 to the closed position covering the housing recess 11 . The heat exchanger 12 is housed in the housing recess 11 covered with the heat insulating cover 14 and is separated from the exhaust heat of the exhaust gas.

As described above, in this embodiment, the heat exchanger 12 of the exhaust heat recovery device 10 of the automobile 1 is located at a position shifted outward from the center of the exhaust pipe 3 through which the exhaust gas of the engine 2 of the automobile 1 is discharged. , one end edge is pivotally supported by a rotating shaft 13 rotatably provided along the extending direction of the exhaust pipe 3 at a position where it comes in contact with the peripheral surface of the exhaust pipe 3 . The rotary actuator 17 rotates the heat exchanger 12 around the rotary shaft 13 .

For example, when exhaust heat is not recovered, the rotary actuator 17 causes the heat exchanger 12 to lie down along the extending direction of the exhaust pipe 3 . In the inverted position heat exchanger 12 , the entire heat exchanger 12 is shifted outward from the center of the exhaust pipe 3 . Therefore, it becomes difficult for the heat exchanger 12 in the inverted position to cut off the flow of the exhaust gas flowing through the exhaust pipe 3 . The exhaust gas flow with the heat exchanger 12 lying down can be one flow, as can the upstream and downstream portions of the heat exchanger 12 for the exhaust pipe 3 . The exhaust gas efficiently flows through the exhaust pipe 3 including the portion where the heat exchanger 12 is arranged.
On the other hand, for example, if the heat exchanger 12 is rotatably supported by the rotating shaft 13 at the center position of the exhaust pipe 3, the heat exchanger 12 extends along the extending direction of the exhaust pipe 3. Even if it assumes a reclined posture, the whole remains in the center of the exhaust pipe 3. A heat exchanger 12 lying down in the middle of the exhaust pipe 3 splits the exhaust gas into two streams. The exhaust gases that are in one stream upstream of the heat exchanger 12 are split into two by the heat exchanger 12 and recombined back into one stream downstream of the heat exchanger 12 . In this case, on the downstream side of the heat exchanger 12 , the two opposing flows join together so as to be involved in the downstream side of the heat exchanger 12 . A vortex is generated when two opposing flows meet. When the vortex is generated in the exhaust pipe 3, the flow of the exhaust gas along the extending direction of the exhaust pipe 3 is obstructed, and the exhaust efficiency is lowered. Moreover, since the heat exchanger 12 steadily lowers the exhaust efficiency, in order to obtain a predetermined flow rate, the diameter of the exhaust pipe 3 must be made larger than in the case without the heat exchanger 12 so as to compensate for the reduction. must be formed. If the diameter of the exhaust pipe 3 is increased for exhaust heat recovery, the overall design of the automobile 1 may also be affected. In this embodiment, the heat exchanger 12 can be provided in the exhaust pipe 3 to secure the flow rate of the exhaust gas in the exhaust pipe 3 without increasing the diameter of the exhaust pipe 3 .

Moreover, in the present embodiment, when recovering exhaust heat, the rotary actuator 17 rotates the heat exchanger 12 from the inverted position to stand on the exhaust pipe 3 . As a result, the amount of exhaust gas that hits and passes through the heat exchanger 12 is increased, and the heat exchanger 12 can efficiently recover the exhaust heat of the exhaust gas. Moreover, even in this upright state, the heat exchanger 12 stands from near the outer periphery of the exhaust pipe 3 toward the center, so that one end edge of the standing heat exchanger 12 on the rotating shaft 13 side It is difficult for the exhaust gas to flow toward the exhaust pipe 3 . Therefore, even when the heat exchanger 12 is standing in the exhaust pipe 3 , the flow of the exhaust gas is less likely to be divided into two by the heat exchanger 12 . The flow of exhaust gas is less likely to be split into two large streams as it passes through the standing heat exchanger 12 and can maintain one flow from upstream to downstream of the heat exchanger 12 .

Further, in this embodiment, the heat exchanger 12 for exhaust heat recovery is rotatably provided inside the exhaust pipe 3 . Therefore, in this embodiment, in order to provide the heat exchanger 12 for exhaust heat recovery, it is not necessary to connect a branch pipe to the exhaust pipe 3 and provide the heat exchanger 12 in the branch pipe. The exhaust heat recovery device 10 of this embodiment can preferably use the internal space of the existing exhaust pipe 3 to minimize the space required outside the exhaust pipe 3, and the vehicle 1 can be compact. can be set to The overall design of the motor vehicle 1 does not have to be changed in order to provide the waste heat recovery device 10 .

In this embodiment, the inverted heat exchanger 12 is housed in the housing recess 11 together with the rotating shaft 13, which is formed by projecting a portion of the peripheral surface of the exhaust pipe 3 outward. The cross section of the exhaust pipe 3 when the heat exchanger 12 is in the inverted position is equivalent to the cross section of the upstream side of the heat exchanger 12 and the downstream side of the heat exchanger 12 . In this embodiment, the pressure loss of the exhaust gas caused by the heat exchanger 12 can be substantially eliminated when the heat exchanger 12 is tilted.

In the present embodiment, the rotary shaft 13 is located upstream of the heat exchanger 12 in the down position in the housing recess 11 . As a result, the heat exchanger 12 that is driven to rotate from the inverted position and rises inside the exhaust pipe 3 rotates from the downstream side toward the upstream side of the exhaust gas flow and rises.
On the other hand, if the rotary shaft 13 is located downstream of the inverted heat exchanger 12, the heat exchanger 12 rotates from the upstream side to the downstream side of the exhaust gas flow and stands up. . The heat exchanger 12 in an oblique position directly entrains a portion of the exhaust gas flow in the exhaust pipe 3 and bisects it. A heat exchanger 12 in an oblique state tends to cause high pressure loss. In the present embodiment, such a high pressure loss can be made difficult to occur.

In this embodiment, a heat insulating cover 14 is provided to cover the accommodation recess 11 . Then, the opening/closing actuator 18 drives the heat insulation cover 14 so as to be displaced from the accommodation recess 11 . For example, when the exhaust heat is not recovered, the opening/closing actuator 18 covers the housing recess 11 with the heat insulating cover 14 . The heat of the exhaust gas flowing through the exhaust pipe 3 is less likely to be transmitted to the interior of the housing recess 11 covered by the heat insulating cover 14 . The heat of the exhaust gas is less likely to be transmitted to the inverted heat exchanger 12 accommodated in the accommodation recess 11 .
Moreover, when exhaust heat is to be recovered, the open/close actuator 18 displaces the heat insulation cover 14 from the housing recess 11 . Therefore, the heat of the exhaust gas is transferred to the heat exchanger 12 even when it is in a tilted posture accommodated in the accommodation recess 11 . In addition, the heat exchanger 12 can efficiently recover the exhaust heat of the exhaust gas because the rotary actuator 17 rotates the heat exchanger 12 from the inverted position.

In this embodiment, when the temperature of the heat medium flowing through the heat exchanger 12 becomes high, the rotary actuator 17 rotates the heat exchanger 12 so as to tilt it. As a result, the temperature of the heat medium flowing through the heat exchanger 12 can be prevented from becoming abnormally high.

In this embodiment, the heat exchanger 12 is provided downstream of the catalyst device 4 in the exhaust pipe 3 . Therefore, the exhaust heat recovery device 10 can recover the exhaust heat of the exhaust gas from the exhaust gas whose temperature and pressure have been lowered in the catalyst device 4, not from the very high temperature and high pressure exhaust gas discharged from the engine 2. . The heat exchanger 12 and the like of the exhaust heat recovery device 10 do not need to be made of high-performance materials so as to withstand the extremely high-temperature and high-pressure exhaust gas discharged from the engine 2 .

FIG. 5 is an explanatory diagram of a first modification of the exhaust heat recovery device 10 for the automobile 1 according to the first embodiment.
FIG. 5A shows a state in which the heat exchanger 12 is placed in an inverted posture along the extending direction of the exhaust pipe 3 and accommodated in the accommodation recess 11 .
FIG. 5(B) shows a state in which the heat exchanger 12 is rotated from the laid down position and stood up within the exhaust pipe 3 .
The exhaust heat recovery device 10 of FIG. 5 does not have the heat insulating cover 14 . Even in this case, the heat exchanger 12 is rotationally driven so as to be switched between the reclining posture so as to be accommodated in the housing recess 11 and the standing posture standing in the exhaust pipe 3, thereby transferring the exhaust heat of the exhaust gas to the heat exchanger. 12 can be used for efficient recovery, or the heat exchanger 12 can be used to make recovery difficult.

FIG. 6 is an explanatory diagram of a second modification of the exhaust heat recovery device 10 for the automobile 1 according to the first embodiment.
FIG. 6(A) shows a state in which the heat exchanger 12 is laid down along the extending direction of the exhaust pipe 3 .
FIG. 6(B) shows a state in which the heat exchanger 12 is rotated from the laid down position and stood up within the exhaust pipe 3 .
The exhaust heat recovery device 10 of FIG. 6 does not have the housing recess 11 . In this case, the rotating shaft 13 is provided inside the exhaust pipe 3 . However, in FIG. 6 , the rotating shaft 13 is provided at a position shifted outward from the center of the exhaust pipe 3 , here at a position shifted outward to the extent that it contacts the peripheral surface of the exhaust pipe 3 . In this case, the heat exchanger 12 that is controlled to have a tilted posture falls down at a position shifted outward from the center of the exhaust pipe 3 so as to follow the outer circumference of the exhaust pipe 3 . The flow of the exhaust gas is less likely to be divided into two by the heat exchanger 12 compared to the case where the exhaust pipe 3 is in an inverted position at the center.

[Second embodiment]
Next, the exhaust heat recovery device 10 for the automobile 1 according to the second embodiment of the present invention will be described. In the following description, differences from the above-described embodiment are mainly described. The same reference numerals as in the above-described embodiment are used for the same components as in the above-described embodiment, and the description thereof is omitted.

FIG. 7 is an explanatory diagram of the mechanical configuration of the exhaust heat recovery device 10 provided in the exhaust pipe 3 of the automobile 1 according to the second embodiment of the present invention.
FIG. 7A shows a state in which the heat exchanger 12 is placed in an inverted posture along the extending direction of the exhaust pipe 3 and accommodated in the accommodation recess 11 .
FIG. 7(B) shows a state in which the heat exchanger 12 is rotated from the tilted posture to stand inside the exhaust pipe 3 .

The exhaust heat recovery device 10 of FIG. 7 has a heat insulating shutter 31 covering the surface of the heat exchanger 12 instead of the heat insulating cover 14 provided for the housing recess 11 .
The heat insulating shutter 31 is composed of a plurality of strip-shaped plates arranged vertically on the surface of the heat exchanger 12 . Each strip-shaped plate is attached to the surface of the heat exchanger 12 at its lower edge.
In this case, for example, when heat exchanger 12 is in an upright position as shown in FIG.
Further, when the heat exchanger 12 is in a tilted posture as shown in FIG. 7A, each strip-shaped plate closes along the surface of the heat exchanger 12 .

Then, the exhaust heat recovery ECU 19 controls recovery of exhaust heat by the heat exchanger 12 by the same control as in FIG.
However, the open/close actuator 18 drives the heat insulating shutter 31 composed of a plurality of strip-shaped plates so as to expose the surface of the heat exchanger 12 by the process following step ST3 instead of step ST2 in FIG. . When recovering exhaust heat, the open/close actuator 18 opens the heat insulating shutter 31 so as to open the heat insulating shutter 31 with respect to the surface of the heat exchanger 12 . Thereby, the surface of the heat exchanger 12 is exposed, and the exhaust gas can pass through the heat exchanger 12 efficiently.
In addition, the open/close actuator 18 drives the heat insulating shutter 31 composed of a plurality of strip-shaped plates so as to cover the surface of the heat exchanger 12 by the process preceding step ST8 instead of step ST9 in FIG. . When exhaust heat is not recovered, the opening/closing actuator 18 closes the heat insulating shutter 31 so that the surface of the heat exchanger 12 is covered with the heat insulating shutter 31 .

As described above, in this embodiment, the heat insulating shutter 31 that covers the surface of the heat exchanger 12 is provided. The opening/closing actuator 18 then drives the heat insulating shutter 31 so that the surface of the heat exchanger 12 is exposed. For example, when the exhaust heat is not recovered, the opening/closing actuator 18 covers the surface of the heat exchanger 12 with the heat insulating shutter 31 . The heat of the exhaust gas is less likely to be transmitted to the heat exchanger 12 whose surface is covered with the heat insulating shutter 31 .
Moreover, when recovering exhaust heat, the opening/closing actuator 18 drives the heat insulating shutter 31 so that the surface of the heat insulating shutter 31 is exposed. Therefore, the heat of the exhaust gas is transferred to the heat exchanger 12 . In addition, the heat exchanger 12 can efficiently recover the exhaust heat of the exhaust gas because the rotary actuator 17 rotates the heat exchanger 12 from the inverted position.

In this embodiment, the heat insulating shutter 31 opens and closes with respect to the surface of the heat exchanger 12 by being driven by the open/close actuator 18 .
In addition, for example, the heat insulating shutter 31 may be opened with respect to the surface of the heat exchanger 12 by the attendant when the heat exchanger 12 is in the standing posture. Even in this case, when the heat exchanger 12 is laid down, the heat insulating shutter 31 can be closed against the surface of the heat exchanger 12 by its own weight. The heat insulating shutter 31 can be opened and closed with respect to the surface of the heat exchanger 12 by its own weight.

FIG. 8 is an explanatory diagram of a modification of the exhaust heat recovery device 10 for the automobile 1 according to the second embodiment.
FIG. 8(A) shows a state in which the heat exchanger 12 is laid down along the extending direction of the exhaust pipe 3 .
FIG. 8(B) shows a state in which the heat exchanger 12 is rotated from the laid down position and stood up within the exhaust pipe 3 .
The exhaust heat recovery device 10 of FIG. 8 does not have the housing recess 11 . The heat exchanger 12 is rotationally driven within the exhaust pipe 3 . Even in such a case, by opening and closing the heat insulating shutter 31 with respect to the surface of the heat exchanger 12, it is possible to make it difficult for the exhaust heat of the exhaust gas to be transmitted to the heat exchanger 12.

[Third Embodiment]
Next, the exhaust heat recovery device 10 for the automobile 1 according to the third embodiment of the present invention will be described. In the following description, differences from the above-described embodiment are mainly described. The same reference numerals as in the above-described embodiment are used for the same components as in the above-described embodiment, and the description thereof is omitted.

FIG. 9 is an explanatory diagram of the mechanical configuration of the exhaust heat recovery device 10 provided in the exhaust pipe 3 of the automobile 1 according to the third embodiment of the present invention.
FIG. 9A shows a state in which the heat exchanger 12 is housed in the housing recess 11. FIG.
FIG. 9B shows a state in which the heat exchanger 12 is erected inside the exhaust pipe 3 .
In the exhaust heat recovery device 10 of FIG. 9 , the rotating shaft 13 is provided at the center of the opening formed in the circumferential surface of the exhaust pipe 3 by the housing recess 11 in the extending direction of the exhaust pipe 3 . The rotating shaft 13 is rotatably provided along the extending direction of the exhaust pipe 3 .

The opening is closed by a closing member 32 pivotally supported by the rotating shaft 13 .
One end of the heat exchanger 12 is pivotally supported by the rotating shaft 13 so as to be erected with respect to the clogging member 32 .

Then, the exhaust heat recovery ECU 19 controls recovery of exhaust heat by the heat exchanger 12 by the same exhaust heat recovery control as in FIG. However, steps ST2 and ST9, which are processes using the open/close actuator 18, are unnecessary. The rotary actuator 17 rotates the heat exchanger 12 around the rotary shaft 13 .
For example, when the exhaust heat is not recovered, the rotary actuator 17 rotates the heat exchanger 12 so that the heat exchanger 12 is positioned in the housing recess 11 outside the opening as shown in FIG. 9A. The rotary actuator 17 stops rotating the heat exchanger 12 at a position where the opening is blocked by the blocking member 32 .
When recovering exhaust heat, the rotary actuator 17 rotates the heat exchanger 12 so that the heat exchanger 12 is positioned inside the exhaust pipe 3 as shown in FIG. 9B. The rotary actuator 17 stops rotating the heat exchanger 12 at a position where the opening is blocked by the blocking member 32 .
Moreover, the heat exchanger 12 of the present embodiment is formed in a size that does not block the entire exhaust pipe 3 even when positioned inside the exhaust pipe 3 as shown in FIG. 9B. As a result, the heat exchange efficiency is lower than when the heat exchanger 12 is formed in a size that substantially blocks the entire exhaust pipe 3, but the heat medium is less likely to reach an abnormally high temperature.

As described above, in the present embodiment, the heat exchanger 12 for exhaust heat recovery is rotatably provided in the exhaust pipe 3 as in the above-described embodiment, so that the heat exchanger 12 for exhaust heat recovery It is not necessary to provide a branch pipe for the exhaust pipe 3 in order to provide the . The exhaust heat recovery device 10 of the present invention can be installed in the motor vehicle 1 in such a way that it is compact and requires minimal additional space, preferably utilizing the inside of the existing exhaust pipe 3 .

In addition, you may provide the heat insulation shutter 31 on the surface of the heat exchanger 12 of this embodiment.

The above embodiments are examples of preferred embodiments of the present invention, but the present invention is not limited to these, and various modifications and changes are possible without departing from the gist of the invention. .

DESCRIPTION OF SYMBOLS 1... Automobile (vehicle), 2... Engine, 3... Exhaust pipe, 4... Catalyst device, 10... Exhaust heat recovery device, 11... Receiving recess, 12... Heat exchanger, 13... Rotating shaft, 14... Heat insulating cover, 15 Heat medium temperature sensor 16 Timer 17 Rotary actuator 18 Open/close actuator 19 Exhaust heat recovery ECU 31 Heat insulating shutter 32 Closing material

Claims (9)

a rotating shaft provided rotatably along the extending direction of the exhaust pipe at a position shifted outward from the center of the exhaust pipe for discharging the exhaust gas of the engine of the vehicle;
a heat exchanger having one end edge supported by the rotating shaft;
a rotary actuator that rotates the heat exchanger around the rotary shaft;
has
The rotary actuator is
When exhaust heat is not recovered, the heat exchanger is laid down along the extending direction of the exhaust pipe,
When recovering exhaust heat, the heat exchanger is rotated from the tilted position and erected in the exhaust pipe;
Exhaust heat recovery equipment for vehicles.
The exhaust pipe is formed with a housing recess formed by protruding a part of the peripheral surface to the outside,
The rotating shaft is provided so as to extend in a direction in contact with the peripheral surface of the exhaust pipe in the housing recess,
The heat exchanger is housed in the housing recess in an inverted posture,
The exhaust heat recovery device for a vehicle according to claim 1.
The rotating shaft is positioned upstream of the heat exchanger in the inverted position in the housing recess,
The exhaust heat recovery device for a vehicle according to claim 2.
a heat insulating cover covering the accommodation recess;
an opening/closing actuator that drives the heat insulating cover to move away from the housing recess;
has
The opening/closing actuator is
When exhaust heat is not recovered, the housing recess is covered with the heat insulating cover,
When recovering exhaust heat, the heat insulating cover is displaced from the accommodation recess,
4. The vehicle exhaust heat recovery system according to claim 2 or 3.
a heat insulating shutter covering the surface of the heat exchanger;
an open/close actuator that drives the thermal insulation shutter so as to expose the surface of the heat exchanger;
has
The opening/closing actuator is
When exhaust heat is not recovered, the surface of the heat exchanger is covered with the heat insulating shutter,
exposing the surface of the heat insulating shutter when recovering exhaust heat;
4. The vehicle exhaust heat recovery system according to claim 2 or 3.
an opening formed in an exhaust pipe for discharging exhaust gas from a vehicle engine;
a rotating shaft provided rotatably along the extending direction of the exhaust pipe at a central portion of the opening in the extending direction of the exhaust pipe;
a blocking member pivotally supported by the rotating shaft so as to block the opening;
a heat exchanger having one end pivotally supported by the rotating shaft so as to be erected with respect to the clogging member;
a rotary actuator that rotates the heat exchanger around the rotary shaft;
has
The rotary actuator is
When exhaust heat is not recovered, the heat exchanger is positioned outside the opening and is driven to rotate so that the closing member closes the opening;
When recovering exhaust heat, the heat exchanger is positioned inside the opening, and the closing member is driven to rotate so as to close the opening.
Exhaust heat recovery equipment for vehicles.
The heat exchanger is formed so as not to block the entire exhaust pipe when positioned within the opening.
The exhaust heat recovery device for a vehicle according to claim 6.
The rotary actuator is
When the temperature of the heat medium flowing through the heat exchanger reaches a high temperature, the heat exchanger is driven to rotate so as to fall down.
The vehicle exhaust heat recovery system according to any one of claims 1 to 7.
The heat exchanger is provided downstream of the catalyst device in the exhaust pipe,
The vehicle exhaust heat recovery system according to any one of claims 1 to 8.

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