JP2001336417A - Exhaust apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust apparatus for an internal engine having an exhaust-purifying function, a noise-suppressing function and the like, in which breakage of a catalyst due to high temperature exhaust gas is prevented, temperature rise characteristics of the catalyst during a start of the internal combustion engine is improved, and further, reduction in a manufacturing cost, space saving, improvement of assemble-ability, and so on are achieved. SOLUTION: An exhaust apparatus comprises an exhaust-purifying unit 20 arranged in an exhaust passage 3 and having a catalyst 26, and a radiator unit 10 arranged at an upstream side of the exhaust gas-purifying unit 20 in the exhaust passage 3 and being able to control temperature of the exhaust gas flowing into the exhaust-purifying unit 20. The radiator unit 10 comprises a heat exchanger 11 arranged in the exhaust passage 3 for radiating the heat of exhaust gas, a bypass passage 4 for passing the exhaust gas by bypassing the heat exchanger 11, and a flow control valve 12 for regulating a ratio of the exhaust gas passing through the heat exchanger 11 arranged in the exhaust passage 3 and the bypass passage 4. The exhaust gas-purifying unit 20 and the radiator unit 10 are integrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a vehicle, a mechanical device,
The present invention relates to an exhaust device used for an internal combustion engine of a plant or the like.

[0002]

2. Description of the Related Art For example, an exhaust system used for an automobile, which is a typical internal combustion engine, generally includes a catalyst (exhaust gas purifying unit) for purifying exhaust gas and a muffler (silent unit) for silencing noise. I have. Specifically, the exhaust system of an automobile includes an exhaust manifold, a start catalyst, piping, a vibration absorption mechanism, a catalyst,
It is composed of components such as piping, sub-muffler, piping, muffler, tail pipe, etc. Internal combustion engine (engine)
The exhaust gas discharged from the exhaust gas passes through the above-described constituent devices in order, is purified of harmful substances by a catalyst, is silenced by a muffler, and is then released into the atmosphere.

[0003]

The catalyst cannot purify the exhaust gas until a predetermined activation temperature is reached. Therefore, in order to activate the catalyst early and purify the exhaust gas at the time of starting the engine having a low exhaust gas temperature, the catalyst is disposed upstream of the exhaust passage so that the catalyst is discharged from the engine and before the temperature drops. It is desirable to raise the temperature of the catalyst early by exposing it to exhaust gas. However, the exhaust gas temperature fluctuates greatly as in a vehicle engine,
If the temperature reaches close to ° C., the catalyst may be overheated and destroyed by the high temperature exhaust gas.

For this reason, in a conventional exhaust system of an internal combustion engine, a main catalyst is disposed downstream of an exhaust passage which is not exposed to exhaust gas immediately after being exhausted from the engine, so that exhaust gas purification at engine start-up is performed. Therefore, a small-capacity start catalyst is provided upstream of the exhaust passage.

[0005] Further, there is a demand to integrate the exhaust system of the internal combustion engine to reduce the manufacturing cost, save the whole space, and improve the assemblability, but as described above, the conventional exhaust system has a plurality of exhaust systems. For reasons such as providing a catalyst,
It was complicated.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an exhaust system for an internal combustion engine, in which the catalyst is prevented from being destroyed by high-temperature exhaust gas while improving the temperature rise characteristics of the catalyst when the internal combustion engine is started. , Manufacturing cost reduction, space saving,
Another object of the present invention is to provide an exhaust device capable of improving the assemblability and the like.

[0007]

According to the first aspect of the present invention, an exhaust device for an internal combustion engine (1) is provided in an exhaust passage (3) of the internal combustion engine (1). And an exhaust gas purification unit (20) having a catalyst (26) and an exhaust gas purification unit (20) provided upstream of the exhaust gas purification unit (20) in the exhaust passage (3) to control the temperature of exhaust gas flowing into the exhaust gas purification unit (20). A heat radiating section (10).

As described above, by providing the heat radiating portion (10) capable of controlling the exhaust gas temperature on the upstream side of the catalyst (26),
The destruction of the catalyst due to the high-temperature exhaust gas can be prevented, and the catalyst can be arranged near the internal combustion engine in the exhaust passage. This allows
Early temperature rise of the catalyst can be achieved when the internal combustion engine is started, and an exhaust gas purifying effect can be obtained early. Also, there is no need to provide a start catalyst for purifying exhaust gas at the time of starting the internal combustion engine separately from the main catalyst,
These catalysts can be integrated.

Further, the invention according to claim 2 is characterized in that the exhaust gas purifying section and the heat radiating section are integrated. As described above, by integrally configuring the exhaust gas purifying unit and the heat radiating unit, it is possible to reduce manufacturing costs, save space, improve assemblability, and the like.

The heat radiating section (10) is specifically provided in the exhaust passage (3) and releases heat of the exhaust gas to the atmosphere. 11)
And a bypass passage (4) for allowing the exhaust gas to bypass the heat exchanger (11) and a flow rate of the exhaust gas provided in the exhaust passage (3) and flowing through the heat exchanger (11) and the bypass passage (4). And a flow rate adjusting means (12) for adjusting the ratio.

Further, the flow rate adjusting means (12) adjusts the flow rate ratio of the exhaust gas flowing through the heat exchanger (11) and the bypass passage (4).
The temperature of the exhaust gas flowing into the exhaust gas purification unit (20) is detected by exhaust gas temperature detection means, and the control unit (40) controls the exhaust gas temperature based on the detected exhaust gas temperature.

Further, in the invention described in claim 5, the flow rate adjusting means (12) is provided in the exhaust passage (4) downstream of the heat exchanger (11). Accordingly, the flow rate adjusting means (12) comes into contact with the exhaust gas having a low temperature after the heat radiation, and the flow rate adjusting means (12) can be prevented from being destroyed at a high temperature.
Therefore, it is possible to improve the durability and reliability of the flow rate adjusting means (12).

In the invention described in claim 6, the exhaust passage (3) has a smaller exhaust resistance on the heat exchanger (11) side than on the bypass passage (4) side. . Thereby, at the branch point between the heat exchanger (11) side and the bypass passage (4) side in the exhaust passage (3),
The exhaust gas from the exhaust manifold (2) is configured to flow toward the heat exchanger (11) by inertia. With such a configuration, when the exhaust passage (3) on the heat exchanger (11) side is opened by the flow rate adjusting means (12), the exhaust gas flows smoothly to the heat exchanger (11) side and the heat exchanger (1
When the exhaust passage (3) on the 1) side is closed, the exhaust gas flows to the bypass passage (4) side.

Further, the invention according to claim 7 is characterized in that the internal combustion engine (1) is provided with a muffling part (20) for reducing exhaust noise. Further, the invention according to claim 8 is characterized in that the sound deadening section (20) includes a sound absorbing material (25), and the catalyst (26) is supported by the sound absorbing material (25). With such a configuration, the exhaust gas purification unit and the noise reduction unit can be easily integrated.

The apparent heat capacity of the supported catalyst (26) can be reduced by forming the sound absorbing material (25) in, for example, a wire shape. Thus, when the temperature of the exhaust gas rises immediately after the start of the internal combustion engine, the temperature of the catalyst (26) can be raised quickly. Further, by supporting the catalyst (26) on the wire-shaped sound absorbing material (25), the catalyst (26)
Although a temperature difference occurs in each place, the exhaust gas purifying action can be obtained from a place where the temperature is raised early. In addition, when the exhaust gas purifying action starts even partially, the exhaust gas purifying reaction is an exothermic reaction, so that the time for raising the temperature of the catalyst (26) can be further reduced.

According to a ninth aspect of the present invention, there is provided an exhaust heat recovery section (30) for recovering exhaust heat of exhaust gas and heating a fluid to be heated in the internal combustion engine (1). Features. As a result, the exhaust heat of the exhaust gas released into the atmosphere can be effectively used.

According to the tenth aspect of the present invention, the heat radiating section (10) includes the case member (13) forming the exhaust passage (3), and the heat exchanger (11) includes the case member (13). 13) is provided on the outer peripheral portion. With such a configuration, the surface area of the heat exchanger (11) can be increased, a high heat exchange capacity can be obtained, and it is possible to cope with a case where the exhaust gas temperature is high.

According to the eleventh aspect of the present invention, the heat exchanger (11) is provided on the outer wall (13a) of the case member (13) that comes into contact with the outside air, and exchanges heat with the outside air. ). Thereby, the surface area of the heat exchange can be further increased, and the heat exchange ability can be improved.

In the twelfth aspect of the present invention, the heat exchanger (11) exchanges heat with exhaust gas provided between the outer wall (13a) of the case member (13) and the outside wall (13a) in contact with the outside air. It is characterized by comprising a first fin (11a) for performing the transfer and a second fin (11b) for transferring the outside air and heat. Thereby, the heat of the exhaust gas can be efficiently released to the atmosphere.

Further, in the invention according to claim 13, the first
And the second fins (11a, 11b) are connected to the joint between the first fin (11a) and the outer wall (13a).
The fin (11b) and the joint with the outer wall (13a) are configured to overlap each other.

With such a configuration, it is possible to improve the heat conductivity of the heat exchanger (11) from the aspect of the configuration. Thereby, it is possible to configure the heat exchanger by using stainless steel or the like, which is excellent in heat resistance but inferior in heat conductivity as compared with aluminum generally used for the heat exchanger,
Heat resistance can be ensured even when exposed to high-temperature exhaust gas.

Further, in the invention according to claim 14, the first
And the second fins (11a, 11b) and the outer wall (13).
The connection with a) is performed by welding. In this way, the fins (11a, 11
By welding b) and the partition (13a), the fin and the partition can be joined without using an expensive brazing material, and the heat exchanger (11) can be provided at low cost.

The welding between the fins and the partition walls can be carried out by laser welding or ultrasonic welding. Thus, for example, in the case of laser welding, by splitting a laser beam using a prism or the like, it is possible to simultaneously weld a plurality of joints in one scan, and perform welding in a short time. be able to.

In the exhaust heat recovery section (30), the heating of the fluid to be heated by the exhaust heat recovered from the exhaust gas receives the heat from the exhaust gas and transfers the heat to the heated fluid. This is performed via a mediating fluid to be transmitted, and is characterized in that the amount of heating of the fluid to be heated is controlled by adjusting the flow rate of the mediating fluid. As the mediating fluid, a gas can be used as in the invention of the seventeenth aspect, and further, air can be used as in the invention of the eighteenth aspect.

The reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the exhaust device of the present invention is applied to a vehicle including an internal combustion engine (engine).

FIG. 1 shows a schematic configuration of the exhaust device.
Exhaust gas generated by the engine 1 passes through an exhaust manifold 2 and an exhaust passage 3 and is released into the atmosphere. As shown in FIG. 1, the exhaust device 100 of the present embodiment is disposed in the exhaust passage 3 near the exhaust manifold 2.
The exhaust device 100 includes a heat radiating unit 10 that emits heat of exhaust gas to the atmosphere, an exhaust purifying unit that purifies exhaust gas by a catalyst, and a silencing unit that reduces and eliminates exhaust noise. The muffler includes a silencer 20 and an exhaust heat recovery unit 30 that recovers exhaust heat of exhaust gas.

FIG. 2 shows the vehicle mounting position of the exhaust device 100. The exhaust device 100 is arranged at a position on the front side of the engine 1 where cooling air (running air) is likely to hit. Exhaust gas discharged from the engine 1 flows into the exhaust device 100 from above via the exhaust manifold 2 and is discharged from below. Thus, the exhaust device 100 is connected to the engine 1
By arranging immediately below, high-temperature exhaust gas flows into the catalyst provided in the purification silencer 20. For this reason, immediately after the engine 1 is started, the catalyst reaches the activation temperature early and can purify the exhaust gas.

As shown in FIG. 1, the radiator 10 includes a heat exchanger 11 for radiating heat of exhaust gas to the atmosphere, a bypass passage 4 for bypassing the heat exchanger 11 for exhaust gas, and a heat exchanger 11. And a flow rate adjusting valve (flow rate adjusting means) 12 for adjusting a flow rate ratio of the exhaust gas flowing to the bypass passage 4. In the heat radiating section 10, after the engine 1 is started, when the exhaust gas temperature is low, the exhaust gas flows to the bypass passage 4 side, and when the exhaust gas temperature increases, the exhaust gas flows to the heat exchanger 11 side to radiate the exhaust gas. It is configured.

The flow rate of the exhaust gas is controlled by adjusting the opening of the flow control valve 12. The flow control valve 12 controls the control device 4 based on the temperature of the exhaust gas introduced into the purification silencer 20.
Controlled by 0. Specifically, when the exhaust gas temperature is lower than the predetermined temperature, the flow control valve 12 is closed to allow the exhaust gas to flow only to the bypass passage 4 side. The control valve 12 is opened so that the exhaust gas flows to the heat exchanger 11 side.
As the temperature of the exhaust gas increases, the opening of the flow control valve 12 is increased to increase the flow rate to the heat exchanger 11, and the temperature of the exhaust gas is controlled so as not to be higher than necessary.

The temperature of the exhaust gas introduced into the purification silencer 20 is detected by exhaust gas temperature detecting means. In the present embodiment, by detecting the engine speed as the exhaust gas temperature detecting means, it is determined that the exhaust gas temperature is high when the engine 1 is running at high speed and high load, and the exhaust gas temperature is detected indirectly. are doing. Further, a temperature sensor for detecting the temperature of the exhaust gas flowing into the purification muffler 20 in the exhaust passage 3 may be provided, and the temperature of the exhaust gas may be directly detected by the temperature sensor. Furthermore, for example, since the change in the engine coolant temperature is substantially proportional to the change in the exhaust gas temperature, the exhaust gas temperature may be detected indirectly by detecting the engine coolant temperature.

With this configuration, after the engine is started,
When the exhaust gas has a low temperature, the exhaust gas is
If the temperature of the exhaust gas becomes high, the temperature of the exhaust gas is lowered by the heat exchanger 11 and then the exhaust gas is introduced into the catalyst. Can be prevented.

In the heat radiating section 10 of the present embodiment, the flow regulating valve 12 is provided downstream of the heat exchanger 11. For this reason, the exhaust gas after the heat is radiated by the heat exchanger 11 flows through the flow control valve 12, so that the temperature of the flow control valve 12 can be prevented from becoming high. As a result, the durability and reliability of the flow control valve 12 can be improved.

In general, the exhaust system of an internal combustion engine is designed to have a low pressure loss in order to secure an engine output. In addition, in the exhaust device 100 of the present embodiment, for example, the cross-sectional area of the exhaust passage 3 on the side of the heat exchanger 11 is made larger than the cross-sectional area of the exhaust passage 3 on the side of the bypass passage 4. Is configured to have a lower pressure loss. In other words, the exhaust resistance is made smaller on the heat exchanger 11 side than on the bypass passage 4 side, so that the exhaust gas flows more easily on the heat exchanger 11 side. That is, at the branch point between the heat exchanger 11 side and the bypass passage 4 side, the exhaust gas from the exhaust manifold 2 flows to the heat exchanger 11 side by inertia force. With such a configuration, when the flow control valve 12 is open, the exhaust gas smoothly flows to the heat exchanger 11 side, and when the flow control valve 12 is closed, the exhaust gas flows to the bypass passage 4 side.

FIG. 3 is a perspective view showing a specific configuration of the exhaust device 100 of the present embodiment. As shown in FIG. 3, the exhaust device 100 of the present embodiment includes a radiator 10,
0, the exhaust heat recovery unit 30 is integrally formed. Specifically, the heat radiating unit 10 is arranged so as to surround the purification / silence unit 20 and the exhaust heat recovery unit 30 from the upper surface to the front surface in FIG.

Next, the radiator 10 will be described with reference to FIGS. FIG. 4 is a perspective view showing a specific configuration of the heat radiating unit 10, and FIG. 5 is a developed perspective view of the heat radiating unit 10. In the heat radiating portion 10, the exhaust passage 3 is formed by the case member 13. The inside of the case member 13 is partitioned into three exhaust passages 3 by two guide portions 14. Three
A heat exchanger 11 is provided in each of the two exhaust passages 3.

Exhaust gas flows in from a gas inlet 15 opened on the upper surface of the case member 13 and flows downward through the central exhaust passage 3. Then, the exhaust gas is divided into right and left from a lower gap in the drawing of the guide portion 14, flows upward through the exhaust passages 3 on both right and left sides, and then flows out from two gas outlet portions 16. A gap is provided on the back side of the guide portion 14 in the drawing, which serves as a bypass passage 4, and the exhaust gas flowing from the gas inlet portion 15 bypasses the heat exchanger 11 and flows to the gas outlet portion 16. Can be.

Gas outlet 1 in exhaust passage 3 at both ends
6, flow control valves 12 are provided respectively. The flow control valve 12 is formed of a plate-like member fixed to a shaft member, and is configured such that the opening of the flow control valve 12 is adjusted by rotating the shaft member.

The heat exchanger 11 of the heat radiating section 10 includes an outer wall (partition) 13a of the case member 13 and two corrugated fins 11a and 11b symmetrically arranged with the partition 13a interposed therebetween. The first fin 11a is arranged in the exhaust passage 3 inside the case member 13 to exchange heat with exhaust gas.
The second fin 11b is arranged outside the case member 13 to exchange heat with outside air. The second fin 11b is configured to be hit by the traveling wind or the blast by a radiator fan.

Since the heat exchanger 11 requires a high heat exchange capacity when the exhaust gas temperature is high, the heat exchanger 11 is provided on the outer peripheral portion of the case to increase the surface area, and furthermore, the fins 11a and 11b bent in a wave shape are used. The heat exchange capacity is improved by increasing the surface area. Also, the fins 11 outside the case
The exhaust gas is cooled by a forced counterflow by blowing wind of a radiator fan or running wind to b, and heat is radiated into the engine room by radiation.

FIG. 6 shows a main part of the heat exchanger 11, and FIG. 7 shows a method of joining the fins of the heat exchanger 11. Since the heat exchanger 11 is exposed to high-temperature exhaust gas, it is necessary to ensure heat resistance. Therefore, in the present embodiment, the heat exchanger 11 is made of stainless steel, which is a heat-resistant material. Stainless steel is inferior in heat conductivity to aluminum generally used for heat exchangers. For this reason,
In the present embodiment, as shown in FIG. 6, the joint portion between the first fin 11a and the partition wall 13a and the joint portion between the second fin 11b and the partition wall 13a are joined at corresponding positions so as to overlap. . That is, the first fin 11a and the second fin 11b are joined such that the positions of the peaks and valleys of the corrugated shape overlap via the partition 13a.

By adjusting the position of the joint between the first fin 11a and the second fin 11b in this manner, the first fin 1a
The heat is efficiently transmitted from 1a to the second fins 11b through the partition 13a, which can help transfer heat from the exhaust gas to the outside air. With such a configuration of the heat exchanger, it is possible to improve the heat conductivity of the heat exchanger 11 from the aspect of the configuration.

The fins 11a and 11b are joined to both surfaces of the partition 13a by laser welding or ultrasonic welding.
At the time of this welding, it is necessary to join a plurality of joining portions of the partition wall 13a and the fins 11a and 11b one by one. The joints are formed on the same plane.
For this reason, as shown in FIG.
, It is possible to split a laser beam by a prism or the like and to weld a plurality of places simultaneously by one scanning.

Thus, the joining process can be simplified, and the time required for joining can be reduced. In addition, the partition 13a and the fins 11a and 11b can be joined without using a brazing material, and the manufacturing cost of the heat exchanger can be reduced. Further, the partition 13a and the fin 11
When the fins 11a and 11b are joined to each other, the position of the joint between the partition 13a and the fins 11a and 11b can be reliably controlled at the time of joining.
The positions of the peaks and valleys of 11b can be easily adjusted.

Next, the purifying / muffling section 20 will be described with reference to FIGS.
It will be described based on. FIG. 8 is a perspective view of the purification / muffling unit 20, and FIG. 9 is a developed perspective view of the purification / muffling unit 20. As shown in FIGS. 8 and 9, in the purification / muffling unit 20, the inside of the case member 21 is divided by two partition plates 22. A plurality of resonance tubes 23 are arranged between the two partition plates 22. The partition plate 22 and the side surface of the resonance tube 23 are formed of a punched metal having a through hole formed therein, and the exhaust sound is resonantly attenuated by optimizing the design of the diameter of the through hole and the diameter and length of the resonance tube 23. Let me. Furthermore, case member 2
1. Elastic material is disposed on the inner wall surface to attenuate exhaust noise.

A sound absorbing material 25 such as a glass wire or a metal wire is disposed in a gap between the resonance pipes 23 in the purification / silencer 20. The sound absorbing material 25 absorbs the exhaust sound to prevent diffusion and lowers the sound pressure level. On the surface of the wire-shaped sound absorbing material 25, a catalyst 26 for purifying harmful components in exhaust gas is carried. Thus, in the purification silencer 20, the exhaust purification unit that purifies the exhaust gas and the silencer that reduces the exhaust noise are integrated.

Since the wire-shaped sound absorbing material 25 has a large surface area and is divided into small parts, the apparent heat capacity of the supported catalyst 26 can be reduced. As a result, when the exhaust gas temperature rises immediately after starting the engine,
The temperature of the catalyst 26 can be raised early. Further, by supporting the catalyst 26 on the wire-shaped sound absorbing material 25, the catalyst 2
Although the temperature difference 6 occurs in each place, the exhaust gas purifying action can be obtained from the place where the temperature is raised early. Further, when the exhaust gas purifying action is started even partially, the exhaust gas purifying reaction is an exothermic reaction, so that the time for raising the temperature of the catalyst 26 can be further reduced.

In the present embodiment, the catalyst 26 is supported on the wire-shaped sound absorbing material 25. However, the present invention is not limited to this. For example, the catalyst 26 may be supported on a wire-meshed carrier. May be.

Next, the exhaust heat recovery section 30 will be described with reference to FIGS. The exhaust heat recovery unit 30 is disposed downstream of the purification and noise reduction unit 20 and recovers exhaust heat of exhaust gas to heat a fluid to be heated (for example, engine cooling water, engine oil, automatic oil, or the like) in the internal combustion engine. It is used as a source.

However, the temperature of the exhaust gas fluctuates depending on the operating conditions, and may rise to about 1000 ° C. Therefore, if heat is directly exchanged between the exhaust gas (first fluid) and the engine oil or the like (second fluid), problems such as deterioration of the engine oil due to overheating and boiling of the cooling water occur. Therefore, the exhaust heat recovery unit 30 of the present embodiment
Uses air as a medium fluid, temporarily performs heat exchange between exhaust gas and air (third fluid) to transfer heat from exhaust gas to air, and then transfers heat from air to engine oil and the like. It is configured to be.

The exhaust heat recovery section 30 of the present embodiment includes two heat exchangers 32 and 33 housed in a case member 31, and the first heat exchanger 32 converts heat between exhaust gas and air. Exchange is performed, and heat is exchanged between the air and the engine oil in the second heat exchanger 33. That is, the exhaust heat of the exhaust gas as the first fluid is indirectly transmitted to the second fluid, such as engine oil, through the air as the third fluid. Then, the amount of heating of the engine oil and the like (the amount of recovered exhaust heat) is controlled by adjusting the flow rate of the air with a blowing fan or the like (not shown).

In this embodiment, the two heat exchangers 32, 3
3 is plates 32a, 33a and tubes 32b, 33
The plate fin tube type heat exchanger composed of b and b is used as an example. In the first heat exchanger 32, the exhaust gas flows through the gap between the plates 32a from above to below in the drawing, and the air flows through the tube 32b to receive heat from the exhaust gas. In the second heat exchanger 33, air is supplied to the plate 33.
A flows from the right to the left in the gap in the figure, and engine oil and the like flows in the tube 33b and receives heat from the air.

With such a configuration, even if the temperature of the exhaust gas fluctuates rapidly, overheating of the engine oil or the like can be easily prevented by controlling the flow rate of the air as the third fluid.

The reason why the exhaust heat recovery unit 30 is disposed downstream of the purification / silence unit 20 is to give priority to exhaust gas purification by raising the temperature of the catalyst 26 early. That is, the cooling water and the like are supplementarily heated by utilizing the remaining exhaust heat obtained by raising the temperature of the catalyst 26.

FIG. 12 is a cross-sectional view showing a specific configuration example of the exhaust device 100 of the present embodiment. As shown in FIG. 12, the exhaust device 100 heats the engine oil and the like using the exhaust heat recovered by the exhaust heat recovery unit 30, and radiates excess heat by the exhaust heat radiator 35, The intake air is heated by the heater 36, and the vehicle interior is further heated by the vehicle interior auxiliary heater 37.

Next, the operation of the exhaust device 100 having the above configuration will be described with reference to the above-described drawings and FIG. FIG.
Indicates the flow of heat in the exhaust device 100;
(A) shows an engine start and an engine low / medium load, and (b) shows an engine high load.

First, the operation at the time of starting the engine will be described.
When the engine 1 starts, emission of exhaust gas from the engine 1 is started. The exhaust gas flows from the exhaust manifold 2 to the exhaust passage 3. Immediately after the start of the engine, since the exhaust gas temperature is low, there is no need to radiate heat in the heat exchanger 11. Therefore, the flow control valve 12 of the heat radiating unit 10 is closed. Therefore, as shown in FIG. 13A, the exhaust gas flows into the bypass passage 4, bypasses the heat exchanger 11, and flows into the purification silencer 20 without heat radiation.

The exhaust gas flowing into the purification silencer 20 has its exhaust noise reduced by the resonance tube 23 and the like. Further, since the exhaust gas flowing into the purification silencer 20 is not dissipated, the temperature of the catalyst 26 is quickly raised to reach the activation temperature, and
Exhaust gas purification is started early.

In the exhaust device 100 of this embodiment, FIG.
As shown in FIG. 2, the purification silencer 20 is disposed upstream of the exhaust passage 3 where the exhaust gas temperature is high, so that the catalyst 26 can reach the activation temperature early even at the start of the engine where the exhaust gas temperature is low. . Further, in the present embodiment, FIG.
Since the catalyst 26 is supported on the wire-shaped sound absorbing material 25 to reduce the apparent heat capacity of the catalyst 26, the catalyst 26 can reach the activation temperature earlier.

The exhaust gas that has passed through the purification / muffling section 20 flows into the exhaust heat recovery section 30, where the exhaust heat is recovered. The exhaust heat recovered from the exhaust gas is used for heating engine oil and the like and for heating the interior of the vehicle as necessary. Exhaust heat recovery unit 30
The exhaust gas that has passed through is then discharged into the atmosphere.

Even when the warm-up of the engine 1 is completed and the engine 1 is under a low / medium load, the exhaust gas temperature is low, and the exhaust gas is silenced, purified, and exhausted in the same process as described above. Heat recovery is performed.

Next, a case where a high load is applied to the engine 1 will be described. In this case, since the exhaust gas temperature is high, as shown in FIG.
The exhaust gas is radiated by the heat radiating unit 10 to adjust the temperature of the exhaust gas flowing into the purification / silencing unit 20. Specifically, the radiator 1
0, the flow control valve 12 is opened and the exhaust gas is
1 to reduce the exhaust gas temperature to a temperature at which the catalyst 26 is not destroyed. At this time, the opening degree of the flow control valve 12 is controlled by the control unit 40 based on the engine speed, and the flow rate ratio of the exhaust gas flowing through the bypass passage 4 and the heat exchanger 11 is adjusted.

The exhaust gas flowing into the purification silencer 20 is subjected to purification of harmful components by the catalyst 26. At this time, the exhaust gas flowing into the purification silencer 20 is dissipated by the upstream radiator 1.
Since the temperature is adjusted in advance to 0, the catalyst 26 can be prevented from being destroyed by the high-temperature exhaust gas.

Further, the exhaust noise is reduced by the resonance pipe 23 and the like as in the case of starting the engine. After the engine is warmed up, it is considered that the engine oil and the like are sufficiently heated, so that the exhaust heat recovery unit 30 does not recover the exhaust heat. Of course, if you need to heat the cabin,
The exhaust heat recovery by the exhaust heat recovery unit 30 may be performed as needed.

As described above, according to the exhaust system 100 of the present embodiment, the radiator 10 capable of controlling the exhaust gas temperature is provided on the upstream side of the catalyst 26 so that the catalyst 26 can be disposed in the exhaust passage 3 near the engine where the exhaust gas temperature is high. Can be arranged. As a result, the catalyst 26
, The exhaust gas purifying effect can be obtained by increasing the temperature of the catalyst, and the catalyst 26 can be prevented from being destroyed at a high temperature even when the exhaust gas temperature becomes high.

Further, with the configuration of the exhaust device 100 of the present embodiment, an exhaust device (exhaust module) in which the heat radiating unit 10, the purification / silencing unit 20, and the exhaust heat recovery unit 30 are integrated can be provided. As described above, the exhaust device 100 having the exhaust gas purifying function, the silencing function, the exhaust gas temperature control function, the exhaust heat recovery function, and the like achieves a reduction in manufacturing cost, a reduction in space as a whole, an improvement in assemblability, and the like. be able to.

(Other Embodiments) In the above embodiment, the exhaust device 100 is provided with the exhaust heat recovery section 30 for recovering the exhaust heat of the exhaust gas, but the exhaust device 100 shown in FIG.
The exhaust heat recovery unit may be omitted as in the above. Further, the exhaust device 100 shown in FIG. 14 is provided with a temperature sensor 41 for detecting the temperature of the exhaust gas flowing into the purification muffler 20, and the controller 40 controls the opening of the flow regulating valve 12 based on the sensor value. It is configured as follows.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a schematic configuration of an exhaust device in the embodiment.

FIG. 2 is a perspective view showing a vehicle mounting position of the exhaust device of FIG. 1;

FIG. 3 is a perspective view showing a specific configuration of the exhaust device of FIG.

FIG. 4 is a perspective view of a radiator in the exhaust device of FIG. 3;

FIG. 5 is an exploded perspective view of a heat radiating unit of FIG. 4;

FIG. 6 is a perspective view of a heat exchanger in the heat radiating unit of FIG. 4;

FIG. 7 is a cross-sectional view illustrating a method of manufacturing the heat exchanger of FIG.

FIG. 8 is a perspective view of a purification silencer of the exhaust device of FIG. 3;

9 is an exploded perspective view of the purification / muffling unit of FIG.

FIG. 10 is a perspective view of the exhaust heat recovery unit of FIG.

11 is an exploded perspective view of the exhaust heat recovery unit of FIG.

FIG. 12 is a cross-sectional view showing a state in which the exhaust device of the embodiment is mounted on a vehicle.

FIG. 13 is a conceptual diagram showing a heat flow of the exhaust device of the embodiment.

FIG. 14 is a conceptual diagram showing a modified example of the exhaust device of the present invention.

[Explanation of symbols]

1 ... internal combustion engine (engine), 2 ... exhaust manifold, 3
... exhaust passage, 4 ... bypass passage, 10 ... radiator, 11 ...
Heat exchanger, 12 ... flow control valve (flow control means), 20 ...
Purification and silencing unit, 26: catalyst, 30: exhaust heat recovery unit, 40: control unit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F01N 7/08 F01N 7/08 A F02M 31/04 F02M 31/04 A F28D 1/047 F28D 1/047 B (72) Inventor Seiji Kawaguchi 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 3G004 AA01 CA01 CA13 DA08 DA09 DA14 GA06 3G091 AA02 AA05 AA06 AA28 AB01 BA03 BA04 BA08 BA10 CA07 CA08 CA13 DA01 DA02 DB10 EA16 EA17 FA02 FA04 FB02 FB03 FC07 FC08 HA36 HB03 3L103 AA01 AA02 AA05 BB39 CC22 CC27 DD13 DD54

Claims (18)

[Claims] An exhaust device for an internal combustion engine (1), comprising: an exhaust purification section (20) provided in an exhaust passage (3) of the internal combustion engine (1) and having a catalyst (26); (3) An exhaust gas provided with a heat radiator (10) provided upstream of the exhaust gas purification unit (20) and capable of controlling the temperature of exhaust gas flowing into the exhaust gas purification unit (20). apparatus. 2. The exhaust device according to claim 1, wherein the exhaust gas purifying unit and the heat radiating unit are integrated. 3. A heat exchanger (11) provided in the exhaust passage (3) for releasing heat of the exhaust gas into the atmosphere; and a heat exchanger (11) for exchanging the exhaust gas with the heat. A bypass passage (4) for bypassing a heat exchanger (11); and a heat exchanger (11) provided in the exhaust passage (3).
3. The exhaust device according to claim 1, further comprising a flow rate adjusting unit configured to adjust a flow rate ratio of the exhaust gas flowing through the exhaust gas and the bypass passage. 4. 4. An exhaust gas temperature detecting means for detecting a temperature of exhaust gas flowing into the exhaust gas purification section, and the flow rate adjusting means based on the exhaust gas temperature detected by the exhaust gas temperature detecting means. A) a control unit (40) that adjusts the flow rate ratio of the exhaust gas flowing through the heat exchanger (11) and the bypass passage (4) to control the temperature of the exhaust gas flowing into the exhaust gas purification unit (20). 4. The exhaust device according to claim 3, further comprising: 5. The flow rate adjusting means (12) is provided in the exhaust passage (4) downstream of the heat exchanger (11). The exhaust device according to any one of the above. 6. The exhaust passage (3) according to claim 3, wherein exhaust heat resistance is smaller on the heat exchanger (11) side than on the bypass passage (4) side. The exhaust device according to any one of the above. 7. A muffler (20) for reducing exhaust noise of the internal combustion engine (1), wherein the muffler is integrated with the exhaust purifier. The exhaust device according to any one of the above. 8. The sound absorber according to claim 7, wherein the silencer includes a sound absorbing material, and the catalyst is supported on the sound absorbing material. Exhaust device. 9. An exhaust heat recovery unit (30) for recovering exhaust heat of the exhaust gas and heating a fluid to be heated in the internal combustion engine (1), wherein the exhaust heat recovery unit The exhaust device according to any one of claims 2 to 8, wherein the exhaust device is integrated with a purifying unit and the heat radiating unit. 10. The heat radiator (10) includes a case member (13) forming the exhaust passage (3), and the heat exchanger (11) includes an outer peripheral portion of the case member (13). The exhaust device according to any one of claims 1 to 9, wherein the exhaust device is provided in the exhaust device. 11. The heat exchanger (11) is provided on an outer wall (13a) of the case member (13) that comes into contact with outside air, and includes a fin (11b) that exchanges heat with outside air. The exhaust device according to claim 10, characterized in that: 12. The heat exchanger (11) includes a first fin (11a) provided between the case member (13) and having an outer wall (13a) in contact with outside air for exchanging heat with exhaust gas. 11), and a second fin (11b) for exchanging heat with the outside air.
The exhaust device according to claim 1. 13. The first and second fins (11).
a, 11b) are joints between the first fin (11a) and the outer wall (13a) and the second fin (1a).
13. The exhaust device according to claim 12, wherein the first wall and the joint with the outer wall are configured to overlap each other. 14. 14. The first and second fins (11).
The joint between the outer wall (13a) and the outer wall (13a) is made by welding.
The exhaust device according to claim 1. 15. The exhaust device according to claim 14, wherein the welding is laser welding or ultrasonic welding. 16. The heating of the fluid to be heated by the exhaust heat recovered from the exhaust gas in the exhaust heat recovery section (30) is performed via an intermediate fluid that receives heat from the exhaust gas and transmits heat to the heated fluid. The heating amount of the fluid to be heated is controlled by adjusting a flow rate of the intermediate fluid.
5. The exhaust device according to any one of 5. 17. The exhaust device according to claim 16, wherein the intermediate fluid is a gas. 18. The exhaust device according to claim 17, wherein the gas is air.