JP2912625B2 - V-type engine intake system - Google Patents

Description

The present invention relates to an intake device for a V-type engine, and more particularly to a structure of an intake distribution pipe connecting a surge tank and an intake port.

2. Description of the Related Art Conventionally, for example, in Japanese Unexamined Patent Publication No. 60-81458, surge tanks connected to air cleaners are arranged above a pair of cylinder rows arranged in a V-shape and extend from these surge tanks. A V-type engine in which a plurality of intake pipes are connected to intake ports of each cylinder row is disclosed.

In this V-type engine, since the intake ports are opened on the opposite side surfaces of the cylinder row, a plurality of intake distribution pipes extending from the surge tank are led out into a substantially V-shaped space sandwiched between the cylinder rows. I have. For this reason, a plurality of intake pipes are alternately arranged in the space in the axial direction of the crankshaft in the space, and in the adjacent intake pipes in the space, the cylinder row is connected to the axis of the crankshaft. When viewed from the direction, they intersect in a substantially X-shape.

[Problems to be Solved by the Invention] However, according to this configuration, since a plurality of intake pipes connected to the cylinders are collectively led into a limited space between the cylinder rows, these intake pipes are not provided. The piping becomes complicated and complicated in the space.

For this reason, taking into account dimensional crossings and assembly errors around the intake system including the intake distribution pipe and surge tank, it is necessary to secure an appropriate clearance between adjacent intake distribution pipes. There is a problem that the dimension of the distribution pipe in the juxtaposition direction becomes long.

Also, since the intake port to which each intake distribution pipe is connected is located at the deep bottom of the space, when the downstream end of this intake distribution pipe is bolted around the intake port, it extends toward the surge tank. The upstream side of the intake pipe becomes an obstacle. For this reason, it is difficult for fingers and tools to reach deep inside the space between the cylinder rows, and there is also a problem that the assembling work of the intake distribution pipe requires a great deal of work.

The present invention has been made based on such circumstances, and can easily perform the work of assembling the intake distribution pipe.
It is not necessary to secure a special clearance between adjacent intake pipes, making it possible to make the intake system more compact and simplify the shape of the opening between the upstream and downstream pipes of the intake pipe. A V-shaped engine that can match these mating surfaces with high precision and has a good appearance without large exposure of the fuel piping and wiring connected to the fuel injection valve above the intake distribution pipe. The purpose of the present invention is to provide an air intake device.

Means for Solving the Problems In order to achieve the above object, the present invention provides a pair of cylinder rows in which a plurality of cylinders are juxtaposed at intervals in the axial direction of the crankshaft, These cylinders are arranged in a V-shape as viewed from the axial direction, and a plurality of intake ports connected to the respective cylinders are provided on the first side surfaces of the cylinder rows facing each other. A plurality of exhaust ports connected to each cylinder are provided on the side surface of the cylinder 2, and an intake camshaft and an exhaust camshaft are arranged side by side on the upper surface of the cylinder row.
Surge tanks are respectively arranged above the head cover that covers the exhaust camshaft and at positions corresponding to the exhaust camshafts, and lead to the space between the cylinder rows on the opposing side surfaces of these surge tanks. A plurality of intake pipes connected to the intake ports of the cylinder rows on the surge tank side facing each other are provided, and these intake pipes are alternately arranged in the axial direction of the crankshaft in the space, and adjacent to each other. It is premised on an intake device of a V-type engine in which matching intake distribution pipes are crossed in the above space.

The plurality of intake pipes are divided into an upstream pipe section extending from each surge tank to the space and a downstream pipe section extending from the intake port of each cylinder row to an intersection in the space. The part and the downstream pipe part each have a mating surface orthogonal to the pipe axis at each divided end, and are detachably connected by abutting these mating surfaces with each other. The upstream pipe part of the intake distribution pipe, Are formed integrally with a surge tank connected thereto, and the downstream pipe portions of all the intake distribution pipes that intersect in the space are formed integrally with each other, and at a position corresponding to the intake port of each of the cylinder rows. ,
A fuel injection valve for injecting fuel is installed at the intake port, and the fuel injection valve is provided in an intake distribution pipe connected to the intake port of the opposed cylinder row when the cylinder row is viewed from the axial direction of the crankshaft. It is characterized by being located below the upstream pipe section.

[Operation] According to this configuration, the intake pipe is divided into an upstream pipe section and a downstream pipe section, and the total length of each of the upstream pipe section and the downstream pipe section is shortened. If the downstream pipe section is connected to the cylinder row, there is no upstream pipe section extending from the space between the cylinder rows to the surge tank, and if the downstream pipe section is connected to the intake port of the cylinder row in order, there is no cylinder pipe from the top of this space. The range from above to the upper side is opened widely. For this reason, fingers and tools can be easily inserted deep into the space where the intake port opens, and the intake distribution pipe itself does not hinder the connection operation.

In addition, since the downstream pipes of all the intake pipes that intersect in the space are integrated into one unit, there is no need to provide a special clearance between these downstream pipes. Thus, the size of the intake distribution pipe in the direction in which it is arranged can be reduced.

Furthermore, since the mating surfaces of the upstream pipe portion and the downstream pipe portion that abut each other extend in a direction orthogonal to the pipe axis, the shapes of these mating surfaces substantially match the basic cross-sectional shape of the intake distribution pipe. . For this reason, the shape of the mating surface becomes simple and is less susceptible to the influence of dimensional crossing, and a shift or a step is less likely to occur at the abutting portion between the upstream pipe portion and the downstream pipe portion. Therefore, the upstream pipe section and the downstream pipe section can be smoothly continued, and the intake resistance can be reduced.

In addition, when the engine is viewed from the axial direction of the crankshaft, since the fuel injection valve is located below the upstream pipe portion of the intake distribution pipe toward the intake port of the mating cylinder row,
Fuel pipes and wiring connected to the fuel injection valve can be disposed below the intake pipe. Therefore, the fuel pipes and wirings can be covered from above by using the intake pipe, and the appearance of the V-type engine in a plan view is improved.

Embodiment An embodiment of the present invention will be described below with reference to the drawings applied to a V-type six-cylinder engine.

The cylinder block denoted by reference numeral 1 in FIG. 1 includes a lower case 2, and a single crankshaft 3 is supported on the lower case 2. On the upper surface of the lower case 2, a pair of cylinder rows 4 a and 4 b stand upright in a V-shape when viewed from the axial direction of the crankshaft 3.

The cylinder rows 4a and 4b include cylinder bodies 6a and 6b in which three cylinders 5 are arranged in the axial direction of the crankshaft 3, and cylinder heads 7a and 6b connected to the upper surfaces of the cylinder bodies 6a and 6b.
7b and head covers 8a and 8b. A piston 9 is accommodated in each cylinder 5 of the cylinder bodies 6a and 6b. The pistons 9 of the cylinders 5 facing each other are connected to the same crank pin 3a on the crank shaft 3 via a connecting rod 10. I have. For this reason, a pair of cylinder rows 4a, 4b
Are offset in the axial direction of the crankshaft 3.

The cylinder heads 7a, 7b of each cylinder row 4a, 4b are
An intake port 12 and an exhaust port 13 connected to
The exhaust port 12 and the exhaust port 13 are individually opened by an intake valve 14 and an exhaust valve 15. As shown in FIG. 1, the intake ports 12 of the respective cylinders 5 are opened in a line in the axial direction of the crankshaft 3 on the first side surfaces 16 of the cylinder heads 7a and 7b facing each other. The open end of the intake port 12 extends obliquely upward into a substantially V-shaped space 17 sandwiched between the first side surfaces 16 of the cylinder heads 7a and 7b. Further, the intake port 13 of each cylinder is opened on a second side face 19 opposite to the first side face 16 of the cylinder heads 7a and 7b.

As shown in FIG. 1, the intake port 1 of the cylinder heads 7a, 7b
A fuel injection valve 18 for injecting fuel into the intake port 12 is attached to a base portion of 2. The fuel injection valve 18 has an intake port
In a space defined by 12 and the side surfaces of the head covers 8a and 8b, the head covers 8a and 8b are arranged in a vertical posture along the vertical direction.

An intake camshaft 21 for opening and closing the intake valve 14 is provided in the valve operating chamber 20 between the cylinder heads 7a, 7b and the head covers 8a, 8b.
And an exhaust camshaft 22 that drives the exhaust valve 15 to open and close. The intake camshaft 21 is located above the intake port 12 and is located on the side near the space 17 in the valve operating chamber 20. The exhaust camshaft 22 is located above the exhaust port 13 and is away from the space 17 in the valve operating chamber 20.

As shown in FIG. 2, a plug cap which covers an unillustrated spark plug is provided on the upper surfaces of the head covers 8a and 8b.
23 are located. The plug caps 23 are located on the center of the bore of the cylinder 5 and are arranged at intervals in the axial direction of the crankshaft 3.

As shown in FIGS. 1 and 2, the cylinder rows 4a, 4b
The surge tanks 25a and 25b are disposed above the respective components. Each of the surge tanks 25a and 25b has an elongated box shape extending in the axial direction of the crankshaft 3. These surge tanks 25
The a and 25b are directly attached to the upper surfaces of the head covers 8a and 8b, and are located right above the exhaust camshaft 22 that has moved away from the space 17.

Three intake distribution pipes 27 are connected to side surfaces 26 of the surge tanks 25a and 25b facing each other. These intake distribution pipes 27 are guided to the space 17 between the cylinder heads 7a, 7b through above the head covers 8a, 8b. The downstream end of the intake distribution pipe 27 facing this space 17 is smoothly curved downward, and then guided to the intake ports 12 of the cylinder heads 7a, 7b on the side of the opposing surge tanks 25a, 25b.

That is, as shown in FIGS. 1 to 3, the intake distribution pipes 27 extending from the surge tanks 25a and 25b are guided into the space 17 in parallel with each other. These six intake distribution pipes 27 are arranged alternately in the axial direction of the crankshaft 3 when the engine is viewed in plan. For this reason,
The intake distribution pipe 27 connected to the cylinder 5 opposed to the V-shape forms an X when the space 17 is viewed from one axial end of the crankshaft 3.
It is crossed in the shape of a letter.

By the way, such an intake distribution pipe 27 is connected to a surge tank.
An upstream pipe section 28 extending from 25a, 25b above the head covers 8a, 8b to the space 17 and a downstream pipe section 29 extending from the intake port 12 to a crossing point in the space 17 are divided into two parts. The pipe length of the downstream pipe section 29 is set shorter than the pipe length of the upstream pipe section 28.

The upstream pipe section 28 and the downstream pipe section 29 have flange portions 30a, 30b at their respective divided ends. As shown in FIG. 3, the flange portions 30a and 30b extend in a direction orthogonal to the pipe axes of the upstream pipe portion 28 and the downstream pipe portion 29, and form a mating surface at each of the divided ends. And these flange parts 30a, 30b are abutted with each other, and two places separated in the radial direction are fastened and fixed via bolts 31,
Thereby, the upstream pipe section 28 and the downstream pipe section 29 are connected to each other.

In addition, the downstream pipe portion 29 has a flange portion 32 at the downstream end thereof, which is overlapped with the opening peripheral portion 12a of the intake port 12. The flange 32 extends in a direction orthogonal to the pipe axis of the downstream pipe 29. The flange portion 32 has two radially-spaced portions, each having an opening peripheral portion 12
a, whereby the downstream pipe section 29 is connected to the cylinder heads 7a, 7b.

As shown in FIGS. 1 to 3, the upstream pipe portion 28 of the intake distribution pipe 27 is molded together with the surge tanks 25a and 25b connected thereto, and is integrated with the surge tanks 25a and 25b. Further, the upstream pipe portion 28 of the intake distribution pipe 27 is led to the space 17 through a position higher than the fuel injection valve 18. For this reason, as shown in FIG.
When the shaped engine is viewed from the axial direction of the crankshaft 3, it is located below an upstream pipe portion 28 of an intake distribution pipe 27 connected to the intake ports 12 of the opposed cylinder rows 4a and 4b.
It is housed in a dead space surrounded by the intake port 12 and the side surfaces of the head covers 8a and 8b.

As shown in FIG. 4, the space 17 between the cylinder rows 4a and 4b
The downstream pipe portions 29 of all the intake distribution pipes 27 adjacent to each other form an elongated intake pipe unit 34 that is integrally formed with each other and extends in the axial direction of the crankshaft 3. In this intake pipe unit 34, The outer peripheral surfaces of the adjacent downstream pipe portions 29 are in contact with each other without any gap.

Therefore, in this V-type six-cylinder engine, the intake path from the pair of surge tanks 25a and 25b to the intake port 12 of each cylinder 5 is divided into three blocks.

As shown in FIG. 2, suction introduction pipes 38a and 38b are connected to one end faces of the surge tanks 25a and 25b located in the longitudinal direction, respectively. The intake inlet pipes 38a, 38b are curved in an arc shape and their upstream ends face each other. At the upstream ends of the intake inlet pipes 38a, 38b, throttle bodies 39a, 39b each containing a throttle valve (not shown) are provided. Are linked. The upstream ends of the throttle bodies 39a and 39b are joined to each other via a joint 40.
Is connected to an air cleaner (not shown).

In the case of the present embodiment, the joint 40 and the intake pipe
38a and 38b are bypass passages 41 that bypass the throttle valve.
Is communicated by An electromagnetic control valve 42 that keeps the idle speed constant by opening and closing the communication portion is provided in a communication portion of the bypass passage 41 with the joint 40.

In such a configuration, when connecting the intake distribution pipe 27 from the surge tanks 25a, 25b to the intake port 12 to the intake port 12 of each of the cylinder rows 4a, 4b, first, the flange portion of the downstream pipe portion 29 having a short pipe length is used. 32 is superimposed on the opening peripheral portion 12a of the intake port 12, and two places thereof are fastened and fixed by bolts 33.

Next, the flange portion of the downstream pipe portion 29 located in the space 17
The flange portion 30a of the upstream pipe portion 28 is overlapped with the upper portion 30b from above, and the two portions are similarly fastened and fixed by bolts 31. As a result, the six intake distribution pipes 27 are alternately arranged in the space 17 along the axial direction of the crankshaft 3, and the surge tanks 25a, 25b and The intake ports 12 of the cylinder rows 4a and 4b communicate with each other.

When the intake pipe 27 extending from the surge tanks 25a and 25b to the intake port 12 is divided into an upstream pipe section 28 and a downstream pipe section 29, the intake pipe 27 is connected to the cylinder heads 7a and 7b. May be connected to the cylinder heads 7a and 7b sequentially from the downstream pipe portion 29 having a shorter pipe length.

Therefore, when connecting the intake distribution pipe 27 to the cylinder heads 7a, 7b, there is no upstream pipe section 29 extending from the upper part of the space 17 toward the surge tanks 25a, 25b. , 7b is open widely, so that fingers and tools can be easily inserted around the connecting portion.

Therefore, the connection work of the intake distribution pipe 27 does not require any trouble, and the workability is improved as compared with the related art.

Moreover, the downstream pipes of all the cylinders 5 intersecting in the space 17
29 are integrally formed to form one intake pipe unit 34, so that the outer peripheral surfaces of the adjacent downstream pipe sections 29 can be brought into close contact with no gap. For this reason, the intake distribution pipe 27
It is no longer necessary to provide a special clearance at the intersection of the two, and the size L in the direction in which the intake distribution pipes 27 are arranged can be reduced correspondingly, and the area around the intake system can be made compact.

Further, according to the above configuration, the upstream pipe section 28 and the downstream pipe section
Flange portions 30a, 30 which are mating surfaces of 29
Since b extends in a direction orthogonal to the pipe axes of the upstream pipe section 28 and the downstream pipe section 29, the shapes of the inner peripheral edges of these flange sections 30a, 30b substantially match the basic cross-sectional shape of the intake distribution pipe 27. Will do.

For this reason, since the shape of the inner peripheral edges of the flange portions 30a and 30b becomes simple, the influence of the dimension crossing at the time of casting is less likely to occur, and the position of the butt between the upstream pipe portion 28 and the downstream pipe portion 29 is shifted. And steps are less likely to occur. Therefore, the divided ends of the upstream pipe section 28 and the downstream pipe section 29 can be accurately coupled, and the upstream pipe section 28 and the downstream pipe section 29 are smoothly continuous, and the intake resistance is reduced accordingly. be able to.

In addition, when the V-type engine is viewed from the axial direction of the crankshaft 3, the fuel injection valve 18 of each cylinder 5 is an upstream pipe of an intake distribution pipe 27 toward the intake port 12 of the other cylinder row 4 a, 4 b. Part 2
8, the fuel injection valve 18 is connected to the upstream pipe section 2 of the intake distribution pipe 27 extending from the surge tanks 25a and 25b.
The fuel pipes and wires connected to the fuel injection valve 18 can be disposed below the intake distribution pipe 27 without protruding above the fuel injection valve 18.

For this reason, the fuel pipes and wirings can be covered from above by using the intake pipe 27, and there is an advantage that the appearance of the V-type engine when viewed in plan is improved.

[Effect of the Invention] According to the present invention described in detail above, when connecting the downstream pipe portion of the intake distribution pipe to the intake port, there is no upstream pipe portion extending from the space between the cylinder rows toward the surge tank. Since the range from the upper part of the space to the upper part of the cylinder row is wide open, fingers and tools can be easily inserted into the connection between the downstream pipe and the intake port. Therefore, when connecting the intake distribution pipe to the cylinder row, the intake distribution pipe itself can be easily connected without obstructing the work.

In addition, since the downstream pipes of all the intake pipes that intersect in the space are integrated as one unit, the outer peripheral surfaces of the adjacent downstream pipes can be closely contacted without any gap. For this reason, it is not necessary to provide a special clearance at the intersection of the intake distribution pipes, and the size in the direction in which the intake distribution pipes are arranged can be reduced by that amount, and the area around the intake system can be made compact.

In addition, since the shape of the mating surface of the upstream pipe portion and the downstream pipe portion that abuts each other approximately matches the basic cross-sectional shape of the intake distribution pipe, the shape of this mating surface becomes simple, and the influence of dimensional intersection is reduced. This makes it difficult to cause a shift or a step at the abutting portion between the upstream pipe portion and the downstream pipe portion. Therefore, the divided ends of the upstream pipe section and the downstream pipe section can be accurately coupled, and the continuous portion between the upstream pipe section and the downstream pipe section becomes smooth, so that the intake resistance can be reduced.

Furthermore, when the engine is viewed from the axial direction of the crankshaft, the fuel injection valve is located below the upstream pipe of the intake distribution pipe extending from the surge tank. Can be placed under the intake manifold. For this reason, the fuel pipe and the wiring can be covered and hidden from above using the intake pipe, and there is an advantage that the appearance of the V-type engine when viewed in plan is improved.

[Brief description of the drawings]

 BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention. FIG. 1 is a front view of a V-shaped engine partially sectioned, FIG. 2 is a plan view around an intake system, and FIG. 3 is an intake distribution pipe and a surge tank. FIG. 4 is a side view of a downstream pipe portion of an intake distribution pipe. 3 ... Crankshaft, 4a, 4b ... Cylinder row, 5 ... Cylinder, 8a, 8b ... Head cover, 12 ... Inlet, 16 ... First side face, 17 ... Space, 18 ... Fuel injection Valve 19, 2nd side, 21 ... Camshaft for intake, 22 ... Camshaft for exhaust, 25a, 25b ... Surge tank, 27 ... Pipe for intake, 28 ... Upstream pipe, 29 ... … Downstream pipe part, 30a, 30b …… Mating surface (flange part).

Claims (1)

(57) [Claims] 1. A pair of cylinder rows comprising a plurality of cylinders arranged side by side in the axial direction of a crankshaft with a space therebetween are arranged in a V-shape when viewed from the axial direction of the crankshaft. A plurality of intake ports connected to each cylinder are provided on a first side surface facing each other, and a plurality of exhaust ports connected to each cylinder are provided on a second side surface of the cylinder row opposite to the intake port in the cylinder row. The intake camshaft and the exhaust camshaft are arranged side by side on the upper surface of these cylinder rows, and are located above the head cover covering these intake / exhaust camshafts at a portion corresponding to the exhaust camshaft. Surge tanks are respectively arranged, and a plurality of suction tanks are provided on opposite sides of the surge tank in a space sandwiched by the cylinder rows and connected to the intake ports of the cylinder rows on the side of the surge tank facing each other. In a V-type engine in which an air distribution pipe is provided, and these intake distribution pipes are alternately arranged in the axial direction of the crankshaft in the space, and adjacent intake distribution pipes intersect in the space, The pipe is divided into an upstream pipe section from each surge tank to the space and a downstream pipe section from the intake port of each cylinder row to a crossing point in the space, and these upstream pipe section and downstream pipe section are Each split end has a mating surface orthogonal to the pipe axis, and is connected detachably by abutting these mating surfaces with each other. The upstream pipe portion of the intake distribution pipe is integrally formed with a surge tank to which each is connected. The downstream pipes of all the intake distribution pipes that intersect in the space are formed integrally with each other, and the intake pipes are located at positions corresponding to the intake ports of the cylinder rows. A fuel injection valve for injecting fuel is installed in the mouth, and this fuel injection valve is an upstream pipe of an intake distribution pipe connected to the intake port of the opposed cylinder row when the cylinder row is viewed from the axial direction of the crankshaft. An intake device for a V-type engine, wherein the intake device is located below the section.