JP2532666B2 - V-type engine intake device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a V-type engine for an automobile, and particularly to an intake passage for introducing intake air into an intake port of each cylinder according to an engine operating condition. The present invention relates to an intake device for a V-type engine, which is configured to appropriately switch between a low speed intake passage having a long path length and a high speed intake passage having a short path length.

<< Prior Art >> Conventionally, as an intake device of this type, there is one disclosed in JP-A-62-162723.

In the intake system of Japanese Patent Laid-Open No. 62-162723, a long surge tank is provided above each bank of a V-type multi-cylinder engine along the cylinder arrangement direction, and each surge tank has one bank below it. A high-speed intake passage that introduces intake air with a short path length to each cylinder and a low-speed intake passage that introduces intake air with a long path length to each cylinder of the other bank are provided. An on-off valve is provided to close the engine in the low speed rotation range.Further, each surge tank is provided with a communication passage at one end side in the longitudinal direction of the surge tank, and an air cleaner at the other end side. An intake pipe system, which is communicated with the atmosphere via, is connected and configured.

In the engine low speed operation range, the high speed intake passages are closed by the on-off valves, and the intake ports of the cylinders of the right bank are passed from the surge tank above the left bank through the low speed intake passages of long path length. While intake air is introduced, intake air is introduced into the intake port of each cylinder of the left bank from the surge tank on the right bank through the low-speed intake passage also having a long path length. Also,
In the high speed operation range, the high speed intake passage is opened so that the intake air is introduced into each of the intake ports not only from the low speed air passage but also from the high speed intake port having a short path length. In other words, in this high-speed operation range, most of the intake air amount filled in the cylinder is introduced into the intake port of each cylinder of each bank from the surge tank on one bank above it through the high-speed intake passage, and The part is introduced from the surge tank on the other bank through the low speed intake passage. That is, the intake passage communicating with the intake port is switched according to the operating speed of the engine, thereby optimizing the engine operation.

<Problems to be Solved by the Invention> However, in the above-described conventional intake device, each surge tank is used in the entire operating band from the low speed region to the high speed region and has the same function. In order to equalize the distribution of intake air to each cylinder of each bank, both surge tanks are symmetrically arranged almost directly above each bank, while an intake pipe connected to the upstream side of each surge tank. It is necessary to arrange the systems symmetrically, and the throttle body has to be arranged at a position apart from the surge tanks on the upstream side of the branch portion to each surge tank in the intake pipe system.

Therefore, for example, the length of the entire intake passage including the throttle body on the upstream side of the surge tank is still long in the high-speed operation range, and there is a problem that the intake efficiency is reduced accordingly. In addition, there is a problem that the handling of the intake pipe system on the upstream side including the throttle body becomes relatively complicated, impairing the appearance of the engine room, or impairing the workability such as assembling and maintenance. It was

On the other hand, as an apparatus that improves the intake efficiency in the high speed range, there is an intake device disclosed in Japanese Patent Laid-Open No. 64-66416. This intake device is provided with a long surge tank along the cylinder arrangement direction and a throttle body connected to this surge tank, above one bank of a V-type multi-cylinder engine.
The independent intake passage of each cylinder is connected to the surge tank.

However, in the proposal, since the independent intake passages above the V banks are arranged in a curved manner in a narrow space, there is a problem that the intake resistance increases and the charging efficiency is affected. Since there is a large dead space above the bank, effective use of the dead space is desired.

The present invention has been made in view of such circumstances, and an object thereof is to effectively utilize the upper space of the V bank to improve the intake efficiency in the high speed range and to classify the intake resistance of the low speed intake passage. Highly space efficient V that can be reduced
To provide an intake device for a type engine.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention configures an intake device for a V-type engine as follows.

That is, a first passage through which intake air introduced into each cylinder during high-speed operation flows, and a second passage that has a longer path length than the first passage and through which intake air introduced into each cylinder during low-speed operation flows,
In an intake device for a V-type engine, which includes an opening / closing valve that switches between the first passage and the second passage according to an operating state, in one bank above the first and second passages, the upstream side is connected. And a throttle body, and the second passage has an upper and lower two-stage structure in which the second passage extends from between the V banks toward the outside between the V banks and outwardly, and is folded back to form the first passage. The second passage is integrated between the V banks.

Here, it is desirable that the on-off valve is arranged so that the intake resistance with respect to the second passage is low.

Further, it is desirable to arrange the V-type engine vertically.

<Operation> According to the intake system for the V-type engine according to the present invention, the second passage has an upper and lower two-stage structure in which the second passage extends halfway between the banks toward the outside between the banks above the other bank and is folded back. By doing so, the second passages above the V banks can be formed in parallel with each other, and in particular, the bending rate between the V banks can be formed as small as possible to reduce the ventilation resistance. In addition, by forming the second passage in a two-stage configuration, it is possible to create a margin in the space between the banks, and thus the first passage can be guided to the volume chamber with a short path length while keeping its curvature small. The filling efficiency can be improved at both low speed and high speed.

The volume chamber and the throttle body are arranged in the space above one bank, and the upper and lower two chambers are provided above the other bank.
By disposing the second passage having the stepped structure, it is possible to form an intake device having a variable intake length with a layout excellent in space efficiency as a whole while suppressing the height of the intake system.

Further, even if a large intake system component such as a volume chamber or a throttle body is arranged above one bank, a second passage having a long path length is guided and folded back above the other bank, and the second passage is divided into two stages. This second by forming as a configuration
Not only can the passage length be sufficiently secured, but also the heights of the intake systems above both banks can be equalized, and an intake system suitable for a vertically installed engine can be obtained.

In addition, an increase in intake resistance in the integrated portion due to the integration of the first passage and the second passage can be reduced by appropriately disposing the on-off valve.

Example An example of the present invention will be described below with reference to the drawings.

This embodiment shows an example applied to a vertical V-type 6 cylinder engine. FIG. 1 is a front view, FIG. 2 is a plan view,
FIG. 3 is a side view and FIG. 4 is a vertical sectional view.

The intake system for a V-type engine according to the present invention includes a first passage (high-speed intake passage 10) through which intake air introduced into each cylinder flows at high speed operation, and a path length longer than this first passage for low speed operation. V-type having a second passage (communication passage 11, low-speed intake passage 12) through which intake air introduced into a cylinder flows, and an on-off valve 14 that switches between the first passage and the second passage according to operating conditions In the intake system of the engine, a volume chamber (first surge tank 8) connected upstream of the first and second passages and a throttle body 15 are provided above one bank 2 and the second passage is provided with V banks 2, 3 Between the V banks above the other bank 3 is outwardly extended between the V banks to be folded back into two upper and lower stages, and the first passage and the second passage are integrated between the V banks. To do.

More specifically, the engine body 1 has three cylinders 4 in each of the banks 2 and 3 facing each other in a V shape on the left and right,
Intake ports 7 of the respective cylinders are formed in the respective cylinder heads 5, 6 on the opposite surface side of the respective banks 2, 3. Above the right bank 5 of the engine body 1, there is provided a first surge tank 8 as an elongated collecting portion and a volume chamber along the cylinder arrangement direction. Above the left bank 3, there is provided a first surge tank. An elongated second surge tank 9 is provided so as to face 8 and extends along the cylinder arrangement direction.

The first surge tank 8 is connected to a throttle body, which will be described later, and is mainly used for a high speed operation range. That is, the first surge tank 8 is connected to the intake port 7 of each cylinder 4 by the first surge tank 8.
Communication is performed through a high-speed intake passage 10 having a short passage length. As shown in FIGS. 2 and 3, the first surge tank 8 is formed by crossing between the left and right banks 2 and 3 by a single communicating passage 11 forming a part of the second passage. It communicates with the second surge tank 9. And
The pipes forming the communication passage 11 are eccentrically provided on the rear side of both surge tanks 8 and 9.

On the other hand, the second surge tank 9 is mainly used for the medium-low speed operation range, and each intake port 7 of the six cylinders 4 forms a part of the second passage, and has a long low-speed intake passage 12.
Are communicated via. Further, the low speed intake passage 12 is located at a lower position lower than the communication passage 11, and the second surge tank 9
And the second passage as a whole is arranged in an upper and lower two-stage configuration.

The intake passages 10 and 12 are integrated at the center between the banks 2 and 3 and communicate with the intake ports 7 by a branch pipe 13 having a bifurcated appearance. That is, as shown by the broken line in FIG. 1, the branch pipe 13 has two independent passages that communicate with the two intake ports 7 that are formed in the left and right banks 2 and 3 so as to be shifted forward and backward. And a flange portion on the upper end side is made common and integrally formed to achieve compactness and space saving.

An on-off valve 14 is provided in the high speed intake passage 10 at the integrated portion of the intake passages 10 and 12. The on-off valve 14 is set in shape and arrangement such that a surface on the intake port 7 side has a large-diameter curved surface so that the cross-sectional area of the low-speed intake passage 12 is small and the intake resistance is low. As a result, it is possible to prevent the occurrence of torque fluctuations in the engine low speed operation range where intake is performed via the low speed intake passage 12.

By the way, the first surge tank 8 is the second surge tank 9
It is located closer to the center between banks. As a result, the length of the high speed intake passage 10 is set as short as possible, and a space is formed above the right bank 2. A throttle body 15 is arranged in the space above the right bank 2, and the throttle body 15 is connected to the outer side portion of the first surge tank 8. In addition, 15
Reference numeral a is piping for an air cleaner detachably connected to the throttle body 15, and reference numeral 15b is an idle speed controller.

Therefore, according to the intake system of the V-type engine configured as described above, the high-speed intake passage 10 is closed by the opening / closing valve 14 in the engine low-speed operation range, so the intake air flows from the throttle body 15 to one of the first surge tanks. After flowing into 8,
Each bank 2 flows into the other second surge tank 9 through the communication passage 11 that forms the second passage, and from the second surge tank 9 also forms the second passage through the long low-speed air supply passage 12 , 3 are introduced into each cylinder 4.

That is, in the low speed operation range, the first surge tank 8 and the second surge tank 9 that are communicated with each other by the communication passage 11 are connected.
And function as a large surge tank that combines the two volumes, it is possible to obtain a sufficient inertia supercharging effect.

Also, in the high-speed operating range, the on-off valve 14 of the high-speed intake passage 10 is
Is opened, and most of the intake air is introduced from one of the first surge tanks 8 to each cylinder 4 through a high speed intake passage 10 having a short path length, and a part of the intake air is introduced through the low speed intake passage 12 described above. It

Here, the one first surge tank 8 is arranged near the center between the banks, and the throttle body 15 is connected to the first surge tank 8 and is arranged in a space formed above the right bank 3 on the outer side thereof. Since it is provided, the length of the air supply pipe system including the throttle body 15 on the upstream side of the first surge tank 8 and the air cleaner can be shortened as much as possible to configure a compact intake system, and thus the upstream intake air The pipe system can be easily handled, and the appearance of the engine room and the assembling and maintainability can be improved.

Further, since the length of the intake pipe system on the upstream side of the first surge tank 8 can be made as short as possible, the length of the high speed intake passage 10 itself can be made as short as possible. Since it can be set short, the ventilation resistance is reduced particularly in the high-speed operating range where intake air is introduced from the high-speed air supply passage 10, and the intake efficiency in the high-speed operating range can be improved as much as possible. Become.

The first surge tank 8 is shaped so that its cross-sectional area gradually expands from the intake port on the throttle body 15 side toward the downstream side along the intake streamline. As a result, the intake air distribution at the time of high speed operation is improved.

Further, the piping forming the communication passage 11 between the first surge tank 8 and the second surge tank 9 is eccentrically provided on the rear side of both surge tanks 8 and 9 as shown in FIGS. 2 and 3. Has been. As a result, since the communication passage 11 having the highest height in the intake system is arranged on the rear side, the bonnet line of an automobile that is normally inclined forward (the phantom line in FIGS. 2 and 3 is assumed). The height relationship is the same as that of the line a), and it meets the demand for lowering the hood line.

In addition, the communication passage 11 includes an EGR gas passage 16 and a PCV gas passage 17
And are connected. The EGR gas passage 16 is led out from an EGR valve 18 arranged approximately in the center between the banks, and is connected to the upstream side of the communication passage 11. The PCV gas passage 17 is led out from the cylinder head 6 portion of the left bank 3 and is connected to the downstream side of the communication passage 11. According to such a configuration, the EGR gas and the PCV gas flow down in the long passage including the communication passage 11, the second surge tank 9 and the low speed intake passage 12, so that they are sufficiently mixed with the air. Each cylinder 4
Will be evenly distributed to.

In addition, since the EGR gas passage 16 is connected to the upstream side of the PCV gas passage 17, the EGR gas that affects
Gas can be sufficiently mixed and both passages 1
When 6 and 17 are reversely arranged, the oil content in the PCV gas, which is a concern, is not attached to the EGR gas passage opening.

Further, a cold start injector 19 is arranged in the connecting flow path portion of the throttle body 15 downstream of the throttle valve and upstream of the first surge tank 8. According to the arrangement of the cold start injector 19 as described above, the increased fuel from the cold start injector 19 at the cold start is taken in along with the intake air in the first surge tank 8, the communication passage 11, the second surge tank 9, and the low speed air supply. Since it is supplied to each cylinder through a long path flowing down the passage 12,
During that time, a sufficient mixing effect can be obtained, and the fuel can be distributed to each cylinder 4 satisfactorily.

A branch pipe 13 on the downstream side of the integrated portion of the high-speed intake passage 10 and the low-speed intake passage 12 serves as a negative pressure storage source for a brake master back or the like via a check valve 20 that opens and closes by intake negative pressure. The vacuum chamber 21 of is connected. This vacuum chamber 21 is the V of the engine body 1.
It is arranged in the space formed by the upper wall between the banks and the branch pipe 13. According to such a configuration, the space between the V banks can be effectively used and the vacuum chamber 21
Can be installed and the vacuum chamber 21 is arranged close to the cylinder 4 which is a negative pressure generation source, so that a large negative pressure can be stored. Therefore, it is extremely effective as a negative pressure storage source, and the vacuum chamber 21 and the brake master bag can be made compact.

Further, each component pipe of the air supply manifold forming the low speed intake passage 12 is formed by escaping the upper part of the ignition plug mounting position of each cylinder of the left bank, and a gap is formed therein. The plug cap 22 is inserted and arranged in this gap. And this plug cap
High tension cord 23 integrally connected to 22
Is hooked on the cylinder head cover at the upper end of the left bank 3 to prevent it from falling off during maintenance and inspection.

<< Effects of the Invention >> As described in detail in the above embodiments, according to the intake system for the V-type engine according to the present invention, the second passage is directed from the middle of the bank to the outside of the bank above the other bank. The upper and lower two-stage structure is extended and folded back to form a bend rate as small as possible to reduce the ventilation resistance, and the path length is long enough for low speed operation. Can be secured. In addition, by forming the second passage in a two-stage configuration, it is possible to create a margin in the space between the banks, and thus the first passage can be guided to the volume chamber with a short path length while keeping its curvature small. The filling efficiency can be improved at both low speed and high speed.

In addition, by arranging the volume chamber and the throttle body in the space above one bank, an intake device with a single-piece intake length is formed with a layout that is excellent in space efficiency as a whole while suppressing the height of the intake system. it can.

Further, even if a large intake system component such as a volume chamber or a throttle body is arranged above one bank, a second passage having a long path length is guided and folded back above the other bank, and the second passage is divided into two stages. This second by forming as a configuration
Not only can the passage length be sufficiently secured, but also the heights of the intake systems above both banks can be equalized, and an intake system suitable for a vertical engine can be obtained.

In addition, an increase in intake resistance in the integrated portion due to the integration of the first passage and the second passage can be reduced by appropriately disposing the on-off valve.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of an intake device for a V-type engine according to the present invention, FIG. 2 is a plan view, FIG. 3 is a side view, and FIG. 4 is a longitudinal sectional view. 1 ... Engine main body, 2, 3 ... Bank 4 ... Cylinder, 7 ... Intake port 8 ... Surge tank (collecting part, volume chamber), 10 ... High speed air supply passage (first passage) 11 ... … Communication passage (2nd passage), 12 …… Low speed intake passage (2nd passage) 14 …… Open / close valve, 15 …… Throttle body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiro Sunada 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References JP-A-60-156926 (JP, A) JP-A-64 -66416 (JP, A)

Claims (3)

(57) [Claims] 1. A first passage through which intake air introduced into each cylinder during high speed operation flows, and a second passage which has a longer path length than the first passage and through which intake air introduced into each cylinder during low speed operation flows. In an intake device for a V-type engine, comprising: an opening / closing valve for switching between the first passage and the second passage according to an operating state, an intake device for a V-type engine is connected to an upstream side of the first and second passages above one bank. And a throttle body, and the second passage is provided between the V banks and above the other V bank.
An intake device for a V-type engine, characterized in that it has an upper and lower two-stage configuration in which it extends outwardly between the banks and is folded back, and the first passage and the second passage are integrated between the V banks. 2. The first claim according to claim 1, wherein the on-off valve is arranged so that intake resistance is low with respect to the second passage.
An intake device for a V-type engine according to the above item. 3. The intake system for a V-type engine according to claim 1 or 2, wherein the V-type engine is arranged vertically.