JP2889073B2 - Air introduction device in exhaust pipe of internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe air introduction device for purifying exhaust gas by introducing air heated by a heater into an exhaust pipe of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, a catalyst is generally provided in an exhaust passage for purifying exhaust gas of an internal combustion engine. In some cases, air heated by a heater is introduced upstream of the catalyst in the pipe, thereby increasing the temperature of the catalyst and improving the purification efficiency at an early stage. FIG. 4 is a block diagram of a conventional exhaust pipe air introduction device for introducing air heated by a heater into a general exhaust pipe. In the figure, 1
Denotes an internal combustion engine, 2 denotes a transmission attached to the internal combustion engine 1, 3 denotes an intake pipe connected to the internal combustion engine 1, 4 denotes an exhaust pipe connected to the internal combustion engine 1, 5 denotes an exhaust pipe, and 5 denotes an exhaust pipe. A supported catalyst case, 6 is a throttle valve provided in the intake pipe 3, and 7 is an air cleaner which is provided on the upstream side of the intake pipe 3 and incorporates a detector (not shown) for measuring an amount of air taken into the internal combustion engine. , 8 is an electric air pump provided at an inlet of a secondary air introduction pipe described later,
The secondary air introduction pipes 9 and 10 are connected together and connected to the exhaust pipe 4, 11 is a check valve provided near the center of the secondary air introduction pipes 9 and 10, and 12 is a check valve A heater for heating the secondary air downstream of the valve 11; 13 a control valve provided in the secondary air introduction pipe 9 between the electric air pump 8 and the check valve 11 for controlling the amount of secondary air; A controller 15 for controlling the electric air pump 8, the heater 12, and the control valve 13 includes a battery 1 for supplying power to the internal combustion engine,
6 is an air pump relay connected to the electric air pump 14 for supplying or stopping power to the electric air pump 14,
Reference numeral 17 denotes a heater relay that is connected to the heater 12 and supplies or stops power to the heater 12.

Next, the operation will be described. 4, the controller 14 outputs an operation signal to the relay 16 for the air pump and the relay 17 for the heater at the same time when the internal combustion engine 1 is started to operate the air pump 8 and the heater 12. The electric air pump 8 introduces air into the exhaust pipe 4 through the air introduction pipe 9, the control valve 13, the check valve 11, the heater 12, and the air introduction pipe 10. Next, the air introduced into the exhaust pipe 4 reacts with the exhaust gas components HC and CO in the exhaust pipe 4 and the catalyst case 5 to purify the exhaust gas.

In the above-described exhaust pipe air introduction device, the heater 12 is fixed to a vehicle or the internal combustion engine 1 (not shown), but the vibration of the vehicle or the internal combustion engine 1 and the vibration of the exhaust pipe 4 are different from each other. As the air introduction pipe 10 connecting the vessel 12 and the exhaust pipe 4, a pipe having a flexible structure made of metal is generally used because it is necessary to absorb these different vibrations.

[0005]

The conventional air introduction device in the exhaust pipe of an internal combustion engine has a structure in which the air introduction pipe 10 connecting the heater 12 and the exhaust pipe 4 has a flexible structure made of metal as described above. However, since the vibration state of the exhaust pipe 4 is different from that of the vehicle body or the internal combustion engine 1 to which the heater 12 is fixed, the durability of the air introduction pipe 10 is reduced due to the vibration acting on the air introduction pipe 10. was there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has an improved air durability in an exhaust pipe of an internal combustion engine with improved durability against vibration of an air introduction pipe communicating a heater and an exhaust pipe. The purpose is to obtain an introduction device.

[0007]

According to a first aspect of the present invention, there is provided a device for introducing air into an exhaust pipe of an internal combustion engine, wherein a heater for heating air introduced into the exhaust pipe is supported by the exhaust pipe via a retainer. Things.

According to a second aspect of the present invention, there is provided a device for introducing air into an exhaust pipe of an internal combustion engine, wherein a heater for heating air to be introduced into the exhaust pipe is provided on the exhaust pipe via a retainer to provide a catalyst. This is supported by the held catalyst case.

[0009]

According to the air introduction device in the exhaust pipe of an internal combustion engine according to claim 1 or 2 of the present invention, the heater can be separated from the vibration of the vehicle body or the engine, and the vibration acting on the air introduction pipe can be reduced. The same phase as the vibration of the exhaust pipe or the catalyst can be used, and the vibration phase acting on the air introduction pipe is almost eliminated due to the different phase of the conventional vibration, thereby improving the durability of the air introduction pipe. It becomes possible.

[0010] Further, by supporting the exhaust air or the catalyst case of the internal combustion engine into which the heated air is introduced,
Since the distance from the heater to the exhaust pipe or the catalyst for introducing air can be shortened, the temperature of the heated air can be prevented from lowering, and the exhaust gas component in the catalyst by promoting the temperature rise of the catalyst The purification efficiency of CO and HC can be improved.

[0011]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment, and the same reference numerals as those in FIG. 4 indicate the same objects. FIG. 2 is a partially enlarged view of the heater 12, the exhaust pipe 4, and the catalyst case 5 (part) shown in FIG. 1. FIGS. 1 and 2 show an example in which the exhaust pipe 4 and the heater 12 are fixed. Is shown. In FIG. 2, reference numeral 18 denotes a holder for fixing the heater 12 to the exhaust pipe 4, and 10 A denotes an air introduction pipe connected to the exhaust pipe 4.

Next, the operation will be described. In FIG. 1, during operation of the internal combustion engine, vibration generated by combustion of the internal combustion engine is transmitted from the engine 1 to the exhaust pipe 4, so that the exhaust pipe 4 always vibrates according to the operation of the internal combustion engine.

By fixing the heater 12 to the exhaust pipe 4 via the retainer 18, the heater 12 has the same vibration phase as the exhaust pipe 4. The air introduction pipe 10A that connects the heater 12 and the exhaust pipe 4 to introduce the secondary air has a vibration phase between the heater 12 and the exhaust pipe 4 that is the same.
The same vibration as that of the heater 12 is performed.

The air introduction pipe 10A is composed of the exhaust pipe 4 and the heater 1
2, the vibration of the air introduction pipe 10A and the exhaust pipe 4 and the vibration of the air introduction pipe 10A and the heater 12 are eliminated. The durability of the tube 10 is improved.

Further, since the heater 12 is attached to the exhaust pipe 4, the distance between the heater 12 and the exhaust pipe 4 can be shortened, and the heat loss due to heat radiation of the air introduction pipe can be reduced. Since the temperature of the air heated in step 12 can be reduced and introduced into the exhaust pipe 4, CO and H of the exhaust gas components by promoting the temperature rise of the catalyst can be increased.
C can be efficiently purified in the catalyst.

Since the heater 12 is attached to the exhaust pipe 4 because it receives the heat of the exhaust gas from the exhaust pipe 4, a heat shield plate or the like (if necessary) is provided between the exhaust pipe 4 and the heater 12. Needless to say, a not-shown) is provided.

Embodiment 2 FIG. In the first embodiment, the heater 12
Is fixed to the exhaust pipe 4, but the heater 12 is
A similar effect can be expected even if the battery is fixed to the catalyst case 5 as shown in FIG. Hereinafter, a second embodiment in which the heater 12 is fixed to the catalyst case 5 will be described. FIG. 3 is an enlarged view of a portion near the air introduction pipe when the heater 12 shown in FIG. 1 is connected to the catalyst case 5. In FIG. 3, 5 is a catalyst case, 18 is a holder for holding the heater 12, 10B
Reference numeral denotes an air introduction pipe communicating the heater 12 and the catalyst case 5. Note that the operation is exactly the same as that of the first embodiment, and a description thereof will be omitted.

[0018]

As described above in detail, according to the air introducing device for an exhaust pipe of an internal combustion engine according to the first aspect of the present invention,
Through the retainer a heater for heating the air introduced into the exhaust pipe
In addition, the exhaust pipe air introduction device of the internal combustion engine according to claim 2 of the present invention, the heater for heating the air introduced into the exhaust pipe, via a retainer,
Because the catalyst is supported by the catalyst case holding the catalyst, the heater has the same phase as the vibration of the exhaust pipe or the catalyst even if it is affected by the vibration generated from the vehicle body or the engine. Alternatively, since it can be reduced as compared with the case where it is fixed to the engine, there is an effect that deterioration of durability due to vibration acting on the air introduction pipe communicating the heater with the exhaust pipe or the catalyst can be prevented.

Further, the position at which the heated air is introduced by attaching the heater to the exhaust pipe or the catalyst case can shorten the distance between the heater and the exhaust pipe or the catalyst. The decrease is small and the effect of promoting the temperature rise of the catalyst is obtained.
Has the effect of being able to purify efficiently.
In addition, the heater holds the exhaust pipe and catalyst through the holder.
The heater and exhaust pipe are supported by the supported catalyst case.
It is possible to install a heater without changing the structure or with a small change
To minimize the cost increase associated with the heater.
Can be obtained. Furthermore, the exhaust heat in the inlet pipe is used.
In the heating used, the inlet pipe must crawl directly on the exhaust pipe
In the case of a heater, such an arrangement is not effective
And can be placed where you want,
This increases the degree of freedom in designing the exhaust pipe system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a side view showing Embodiment 2 of the present invention.

FIG. 4 is a block diagram showing a conventional apparatus for introducing air into an exhaust pipe of an internal combustion engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 4 Exhaust pipe 5 Catalyst case 9 Air introduction pipe 10A, 10B Air introduction pipe 12 Heater 18 Cage

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F01N 3/30-3/36 F01N 3/20

Claims (2)

(57) [Claims] 1. An exhaust pipe air introduction device for an internal combustion engine for introducing heated air into an exhaust pipe of an internal combustion engine, wherein a heater for heating the air introduced into the exhaust pipe is held.
A device for introducing air into an exhaust pipe of an internal combustion engine, the apparatus being supported by the exhaust pipe via a vessel . 2. An exhaust pipe air introduction device for an internal combustion engine, wherein heated air is introduced into an exhaust pipe of the internal combustion engine and exhaust gas is purified by a catalyst provided in the exhaust pipe. Holds heater to heat air to be introduced
An air introduction device in an exhaust pipe of an internal combustion engine, wherein the air introduction device is supported by a catalyst case holding the catalyst via a vessel .