JP2000161052A - Layout of secondary air passage for exhaust emission in v-engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize space by arranging a secondary air passage for exhaust emission for connecting a pair of exhaust emission passage extending from the right and left banks of a V-engine. SOLUTION: In this V-engine E having a first bank BR and second bank BL, a second exhaust emission passage 18L stretching a second cylinder 16L which functions as an air pump and can pause, and a first exhaust emission passage 18R having an exhaust emission control catalyst 19 are connected by the secondary air passage 21 for exhaust emission, which is arranged so as to pass above the transmission M connected to the rear end section of an engine block 11 to supply the exhausted air to the exhaust emission control catalyst 19 from the pausing second cylinder 16L. This constitution makes it possible to compactly lay out the secondary air passage 21 for exhaust emission by effectively utilizing a dead space above the transmission M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-type engine in which a cylinder of one bank can be stopped, and more particularly to an arrangement structure of an exhaust secondary air passage for guiding air discharged from the stopped cylinder to an exhaust gas purification catalyst. .

[0002]

2. Description of the Related Art Some cylinders of a multi-cylinder engine can be deactivated, and air discharged from a deactivation cylinder functioning as an air pump is discharged as secondary air to an exhaust gas upstream of an exhaust gas purification catalyst provided in an exhaust passage. One that activates this exhaust gas purifying catalyst by supplying it is known from Japanese Patent Application Laid-Open No. 8-334016.

[0003]

It is known that a V-type engine in which a cylinder of one bank can be deactivated can be operated. The deactivation side bank and the operation side bank of the V-type engine are connected to an exhaust secondary. If an attempt is made to supply air to the exhaust gas purifying catalyst by connecting through the air passage, there is a problem that the length of the exhaust secondary air passage is inevitably increased. Therefore, in order to effectively use the space in the narrow engine room, it is essential to arrange the exhaust secondary air passage rationally.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has an efficient use of space by rationally disposing exhaust secondary air passages connecting a pair of exhaust passages extending from right and left banks of a V-type engine. The purpose is to plan.

[0005]

According to the first aspect of the present invention, there is provided an engine block having a first bank and a second bank arranged in a V-shape. A normally-operated first cylinder provided in one bank, a restable second cylinder provided in a second bank, an exhaust gas purification catalyst provided in a first exhaust passage extending from the first cylinder, An exhaust secondary air passage connecting a second exhaust passage extending from the cylinder to a position upstream of the exhaust gas purifying catalyst in the first exhaust passage. An arrangement structure of an exhaust secondary air passage in a V-type engine, which is arranged so as to pass above a transmission connected to the vehicle, is proposed.

According to the above configuration, the second exhaust passage connected to the deactivated second cylinder functioning as an air pump is connected to the first exhaust passage having the exhaust gas purifying catalyst to supply air to the exhaust gas purifying catalyst. The exhaust secondary air passage for supply is located above the transmission connected to the rear end of the engine block, so the dead space above the transmission is effectively used and the exhaust secondary air passage is compact. Can be laid out.

According to the second aspect of the present invention,
In addition to the configuration of claim 1, a flow control valve for controlling the flow rate of air flowing through the exhaust secondary air passage is supported between the first and second banks at the rear end of the engine block or on the upper surface of the transmission. There is proposed an arrangement structure of an exhaust secondary air passage in a V-type engine, characterized by the following.

According to the above configuration, the flow control valve is supported by effectively utilizing the dead space between the first and second banks at the rear end of the engine block or the dead space on the upper surface of the transmission. Can be laid out compactly and the flow control valve can be supported with high rigidity. In addition, since the flow control valve can be attached and detached from above, maintenance is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 3 show a first embodiment of the present invention. FIG. 1 is an overall plan view of a V-type engine, FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1, and FIG. It is an arrow view of three directions.

As shown in FIGS. 1 to 3, a V-shape for an automobile
The engine block 11 of the six-cylinder engine E has a cylinder
90 ° to the block 12 and the cylinder block 12
A pair of left and right syringes connected in a V-shape with a bank angle of
Dahead 13_L, 13_RAnd each cylinder head 13_L,
13_RCover 14 joined to the upper end of the head_L, 14 _R
And an oil pump coupled to the lower surface of the cylinder block 12.
And the right cylinder head 13_RYou
And head cover 14_RTo first bank B_RIs composed
And the left cylinder head 13_LAnd head cover 1
4_LTo second bank B_RIs configured. Cylinder block
The transmission M connected to the rear end of the
The cross-sectional area decreases toward. Note that in FIG.
Cover 14_L, 14_RHas been omitted.

[0012] The first bank B _R 3 pieces of the first cylinder 1
6 _R are provided, and these first cylinders 16 _R.
The exhaust gas purifying catalyst 19 is provided on the first rear end of the exhaust passage 18 _R connected via an exhaust manifold 17 _R on. The second bank B _L has three second cylinders 16 _L.
... is provided, the rear end of the second exhaust passage 18 _L connected through an exhaust manifold 17 _L of these second cylinders 16 _L ... is connected to an inlet of the exhaust gas purifying catalyst 19. The third exhaust passage 20 is connected to the outlet of the exhaust gas purification catalyst 19.

The three second cylinders 16 of the second bank B _L
L can be stopped, and the fuel supply from a fuel injection valve (not shown) is interrupted under predetermined operating conditions. At this time 3
The second cylinders 16 _L ... Function as an air pump, and supply air (exhaust not containing fuel) to the second exhaust passage 18 _L.
To be discharged.

The first exhaust passage _18R and the second exhaust passage _18L
Are connected by the exhaust secondary air passage 21. The exhaust secondary air passage 21 has an upstream side (a second exhaust passage 18).
The check valve 22 on the _L side and the downstream side (the first exhaust passage 18 _R)
Side) and the flow control valve 23 are provided in series. The check valve 22 is connected to the first exhaust passage 18 from the second exhaust passage 18 _L side.
Permitting air flow to the _R side, to regulate the air flow from the first exhaust passage 18 _R side to the second exhaust passage 18 _L side. The flow control valve 23 is fixed at the rear end of the cylinder block 12 and between the first and second banks B _R and B _L , and the exhaust secondary air passage 21 extends from the rear end of the cylinder block 12. It is arranged above the transmission M so as to project rearward.

Second exhaust passage 18_LOn-off valve 2 provided in
4 is located immediately downstream of the branch of the exhaust secondary air passage 21
In the closed position shown by a solid line in FIG.
18 _LTo close the exhaust secondary air passage 21 and
In the open position shown by the line, the second exhaust passage 18_LOpen
The exhaust secondary air passage 21 is closed. Connect to on-off valve 24
Diaphragm actuator 25 is
25₁Negative pressure chamber 25 partitioned by_TwoAnd this
Switching valve 26 for driving the ear actuator 25
Is the negative pressure chamber 25_TwoThe atmospheric pressure port where the atmospheric pressure acts
26₁And negative pressure port 26 to which intake negative pressure acts_TwoWhat
Connect to one or the other.

[0016] changeover valve 26 communicates the negative-pressure chamber 25 ₂ of the diaphragm actuator 25 to the negative pressure port 26 _2, the on-off valve 24 diaphragm 25 ₁ drawn in is driven to the solid-line position in FIG. 1, the negative pressure chamber 25 ₂ to atmospheric pressure port 26
_When communicating with ₁ , the diaphragm 251 is pushed and the on-off valve 24 is driven to the position indicated by the dashed line in FIG.

A temperature sensor 27 provided in the third exhaust passage 20
The electronic control unit U, to which a signal from is input, controls the switching valve 26 and the flow control valve 23.

Next, the operation of the embodiment of the present invention having the above configuration will be described.

When the warm-up of the engine E is not completed and the temperature of the cooling water is lower than a predetermined value, it is determined that the exhaust gas purifying catalyst 19 has not been activated, and the supply of the exhaust secondary air is stopped. Execute. When the three second cylinders 16 _L ... Of the second bank B _L are in a rest state, the supply of the exhaust secondary air is discharged from the second cylinders 16 _L. the air to be, is performed by supplying to the second exhaust passage 18 _L, check valve 22, flow control valve 23 and the first exhaust passage 18 exhaust gas purifying catalyst 19 through _R. Second cylinder 16 _L ...
The stop condition is that the engine speed Ne is low to medium speed (for example,
1500 rpm <Ne <3500 rpm), the vehicle speed V is the start completion vehicle speed (for example, V> 15 km / h), and the throttle opening θ is a low opening (for example, 5 ° <θ <2).
0 °).

When the suspension condition is satisfied, the second bank B _L
Stop supplying fuel to the three second cylinders 16 _L , and after a predetermined time (for example, one second) elapses therefrom, the second
After confirming that the residual fuel in the cylinders 16 _L has been completely discharged, the diaphragm actuator 25 is operated by a command from the electronic control unit U to switch the open / close valve 24 to the position indicated by the solid line in FIG. As a result, the second bank B _L
Three air discharged from the second cylinder 16 _L ... of is supplied from the second exhaust passage 18 _L in the exhaust secondary air passage 21 and the first exhaust passage 18 exhaust gas purifying catalyst 19 through _R. When the exhaust secondary air is supplied to the exhaust gas purifying catalyst 19 in this manner, the three first cylinders 16
_R ... unburned components in the exhaust gas flowing through the first exhaust passage 18 _R is discharged to secondary combustion with oxygen in the exhaust secondary air from the activation of the exhaust gas purifying catalyst 19 is promoted by the heat .

In the meantime, the electronic control unit U performs feedback control of the opening of the flow rate control valve 23 so that the temperature of the exhaust gas purification catalyst 19 detected by the temperature sensor 27 falls within an appropriate range. The exhaust gas purifying catalyst 19 is prevented from deteriorating due to overheating while optimizing activation. When the temperature detected by the temperature sensor 27 exceeds the deterioration temperature of the exhaust gas purifying catalyst 19 for a predetermined time, the on-off valve 24 is switched to the chain line position in FIG. Is stopped to prevent the exhaust gas purification catalyst 19 from deteriorating. Of course, even when the operating condition of the engine E changes and the stop condition of the second cylinders 16 _L ...
And the supply of exhaust secondary air is stopped.

Since the exhaust secondary air passage 21 connecting the second exhaust passage 18 _L and the first exhaust passage 18 _R is disposed above the transmission M, the dead space above the transmission M is utilized. The exhaust secondary air passage 21 can be laid out compactly, and the space in the narrow engine room can be effectively used. Also, the flow control valve 23 provided in the middle of the exhaust secondary air passage 21 is connected to the left and right banks B _L , B _R
Since the flow control valve 23 is supported on the upper surface of the engine block 11 located therebetween, the flow control valve 23 can be compactly laid out using the dead space in the V bank, and the flow control valve 23 can be firmly supported. In addition, since the flow control valve can be attached and detached from above, maintenance is improved. In particular, the bank B _L of the flow control valve 23 left, by arranging the rear end of the B _R, (not shown) intake manifold disposed in the V-bank and the flow control valve 23
Can be avoided.

Further, since the exhaust secondary air passage 21 is arranged in a substantially arc shape along the upper surface of the transmission M (see FIG. 2), when the exhaust secondary air passage 21 is formed of a metal pipe, the exhaust secondary air passage 21 is connected to the engine E. Thus, the thermal stress generated when the exhaust secondary air passage 21 thermally expands due to the heat can be effectively absorbed.

In the first embodiment described above, the flow control valve 2
3 is supported on the upper surface of the engine block 11, and the exhaust secondary air passage 21 is disposed on the upper surface of the transmission M, and the flow control valve 23 is connected to the transmission M as shown by a chain line in FIGS. It can be supported on the upper surface. Also in this case, the exhaust secondary air passage 21 and the flow control valve 23 can be laid out compactly by utilizing the dead space above the transmission M, and the flow control valve 23 is firmly supported. And the maintainability of the flow control valve 23 is improved. In particular, the transmission M
Since the cross section of the rear side is narrower than the cross section of the cylinder block 12, the curvature of the exhaust secondary air passage 21 passing above the transmission M is reduced,
Its length can be minimized.

Although the embodiments of the present invention have been described in detail above, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the first embodiment, the first exhaust passage 18
Is provided with the _R and the second exhaust passage 18 common exhaust gas purifying catalyst 19 downstream of the merging portion of the _L, as in the second embodiment shown in FIG. 4, the first exhaust passage 18 _R and the second exhaust passage 1
8 _L to the first exhaust gas purification catalyst 19 _R and the second
It is also possible to provide 19 _{L of} exhaust gas purifying catalyst. In this case, it can be activated by the first exhaust passage 18 of the first exhaust gas purifying catalyst 19 _R provided on _R is introduced through the second exhaust passage 18 exhaust from _L secondary air passage 21 an air.

[0027]

As described above, according to the first aspect of the present invention, the second stoppable functioning as an air pump is provided.
An exhaust secondary air passage for connecting the second exhaust passage connected to the cylinder and the first exhaust passage having the exhaust gas purifying catalyst and supplying air to the exhaust gas purifying catalyst is connected to the rear end of the engine block. Since it is arranged so as to pass above the transmission, the exhaust secondary air passage can be laid out compactly by effectively utilizing the dead space above the transmission.

According to the invention described in claim 2,
Since the dead space between the first and second banks at the rear end of the engine block or the dead space on the upper surface of the transmission was effectively used to support the flow control valve,
The flow control valve can be laid out compactly and the flow control valve can be supported with high rigidity. In addition, since the flow control valve can be attached and detached from above, maintenance is improved.

[Brief description of the drawings]

FIG. 1 is an overall plan view of a V-type engine.

FIG. 2 is a view in the direction of arrows in FIG. 1;

3 is a view in the direction of arrows in FIG. 1 in three directions.

FIG. 4 is a view corresponding to FIG. 1 according to a second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 11 engine block 16 _R first cylinder 16 _L second cylinder 18 _R first exhaust passage 18 _L second exhaust passage 19 exhaust gas purification catalyst 19 _R first exhaust gas purification catalyst (exhaust gas purification catalyst) 21 exhaust secondary air passage 23 Flow control valve B _R 1st bank B _L 2nd bank M Transmission

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Ryuji Kono 1-4-1 Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Morio Fukuda 1-4-1, Chuo, Wako, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3D038 BA05 BA13 BB01 BC19 3G091 AA02 AA29 BA03 BA32 CA13 CA22 CA23 CB02 CB06 CB07 DA01 DA02 DA03 DA05 DA08 DB10 DC01 EA01 EA07 EA16 EA17 EA30 EA39 FC02 FA04 FA05 FC05 HB02 HB03 HB07 3G092 AA14 AA15 AA16 AC00 BB01 BB10 CA04 CA07 CB05 DC12 DC15 DC16 DF02 DF06 DF08 DF09 DF10 DG06 DG07 EA01 EA02 EA07 EA11 EA21 EA22 EA28 EA29 EC01 FA01 FBX GA17

Claims (2)

[Claims] 1. A first bank (B _R ) arranged in a V-shape
And an engine block (11) having a second bank (B _L ), a constantly operating first cylinder (16 _R ) provided in the first bank (B _R ), and an engine block (11) provided in the second bank (B _L ). A second cylinder (16 _L ) that can be stopped and a first exhaust passage (18) extending from the first cylinder (16 _R ).
_R ), an exhaust gas purification catalyst (19, 19 _R )
And a second exhaust passage (18) extending from the second cylinder ( _16L ).
_L ) to the exhaust gas purifying catalyst (1) in the first exhaust passage ( _18R ).
9, 19 _R ), the exhaust secondary air passage (21) is connected to the engine block (1).
1) An arrangement structure of an exhaust secondary air passage in a V-type engine, which is arranged so as to pass above a transmission (M) connected to a rear end portion. 2. A flow control valve (23) for controlling a flow rate of air flowing through an exhaust secondary air passage (21) is provided to first and second banks (B _R , B _R ) at the rear end of an engine block (11).
The arrangement structure of an exhaust secondary air passage in a V-type engine according to claim 1, characterized in that the exhaust secondary air passage is supported between B _L ) or on the upper surface of the transmission (M).