JPH03271558A - Intake device of multiplecylinder v-engine - Google Patents

Abstract

PURPOSE:To make possible positioning of a surge tank in a low position in V-shaped space so as to contrive miniaturization of an engine total unit by extending a secondary air intake passage diagonally upward from a cylinder and also a primary air intake passage upward so as to detour around the axial line of a valve turning shaft of a control valve. CONSTITUTION:An intake device 10 of a multicylinder V-engine has a surge tank 14 connected to the downstream side of a throttle box through an intake pipe 12 and to primary and secondary ports 5, 6 of each cylinder through an intake passage block 13. The intake passage block 13 has primary and secondary air intake passages 13a, 13b, but here the secondary air intake passage 13b is extended diagonally upward toward the center side in a width direction of the engine 1 from a cylinder, and on the other hand, the primary air intake passage 13a is extended upward from the cylinder at a tilt angle larger than the above mentioned secondary air intake passage 13b so as to detour around a valve shaft 16 of a control valve 15 by which the secondary air intake passage 13b is closed, when an engine speed is at a low value, and further opened when the engine speed is at a high value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intake system for a multi-cylinder V-type engine installed in a passenger car or the like.

[Conventional technology]

Conventionally, the intake system for type II engines changes the effective pipe length or substantial cross-sectional area of the intake pipe that communicates the intake surge tank with the cylinder depending on the engine speed, thereby reducing intake resonance and inertial supercharging effects. There is a system that maintains high charging efficiency from low rotational speed range to high rotational speed range to obtain high output (for example, Japanese Patent Application No. 61-50444). A surge tank was placed above each cylinder row of the engine, and a plurality of intake pipes were arranged in a V-shaped space. The intake pipe consists of a low-speed (primary) pipe with a relatively long overall length so that the effect of inertia supercharging can be obtained at low engine speeds, in other words, during normal engine speeds, and a low-speed (primary) pipe with a control valve that controls engine speed. It was equipped with two types of tubes: a high-speed (secondary) tube with a short overall length to achieve the effect of inertia supercharging during rotation. The secondary intake pipe, to which intake air is supplied when the engine rotates at high speeds, is connected from the cylinder through the square-shaped space to the surge tank above the cylinder, and is bent at a substantially right angle in the square-shaped space.

[Problem to be solved by the invention]

However, in the conventional intake system configured as described above, it is difficult to install a relatively long low-speed pipe within the limited V-shaped space, and the surge tank is not placed above the cylinder. It must be installed with a large protrusion. Therefore, there was a problem in that the engine as a whole became large. In addition, if the secondary intake pipe is bent in the ■-shaped space, the intake resistance will increase,
There is also a problem in that the intake air filling efficiency decreases at high engine speeds when a large amount of intake air is supplied.

[Means to solve the problem]

The intake system for a multi-cylinder V-type engine according to the present invention has a secondary intake passage extending obliquely upward from the cylinder, and
The primary intake passage extends upward so as to bypass the axis of the valve rotation shaft of the control valve.

[Function] The secondary intake passage communicates with the bottom of the surge tank, and the primary intake passage passes through the side of the surge tank and communicates with the internal air chamber, so the length of each intake passage must be It is possible to position the surge tank at a low position within the ■-shaped space while ensuring safety. In addition, since the secondary intake passage communicates approximately linearly with the intake passage within the cylinder,
Inhalation resistance can be reduced.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

FIG. 1 is a front view with a cutaway view showing the main parts of the intake system of a multi-cylinder V-type engine according to the present invention, and FIG. 2 is a plan view showing an enlarged view of the intake system of a multi-cylinder V-type engine according to the present invention. , 3rd
The figures are the same (side view, Figure 4 is rV-IV in Figure 2)
A line cross-sectional view is shown. In these figures, reference numeral 1 indicates a V-type 8-cylinder engine with four cylinders on each side, and reference numerals 2 and 3 indicate cylinder rows arranged in two rows on the left and right of this engine 1. Cylinder row 2 includes cylinders 2a to 2
d, and the cylinder row 3 includes cylinders 3a to 3d.

A primary port 5 and a secondary port 6, which communicate with each other near the intake valve 4 in the cylinder, are opened for each cylinder on surfaces of the cylinder rows 2 and 3 that face each other. A fuel injection nozzle 7 is provided in the intake passage between the primary port 5 and the intake valve 4 so as to face the inside of the passage.

10 is an intake system for a multi-cylinder V-type engine according to the present invention,
This intake device 10 includes a throttle valve (not shown), and a throttle box 11 whose upstream side is communicated with an air cleaner (not shown), and a downstream side of the throttle box 11 which is communicated via an intake pipe 12. , each primary port 5. of each cylinder via the intake passage block 13. It is composed of a surge tank 14 and the like connected to the secondary port 6. The intake pipe 12 of this intake system 10, the intake passage block 13, and the surge tank 14 are connected to both cylinder rows 2.
, 3 is installed in the V-shaped space between the surge tank 14
are two intake passage blocks 13 corresponding to the cylinder row 2.3.
．． It is fixed to the engine 1 via 13.

The intake passage block 13 is a primary intake passage 13a that communicates with the primary port 5 and secondary port 6 of each cylinder.

A secondary intake passage 13b is provided, and two intake passages 13a and 13b are integrally formed for each cylinder for four cylinders. Each of the secondary intake passages 13b extends obliquely upward from the cylinder toward the center side in the width direction of the engine 1, and communicates linearly with the intake passage in the cylinder when the intake passage block 13 is attached to the engine 1. The inclination angle is set so that Note that the length of the secondary intake passage 13b is set so that the effect of inertial supercharging can be obtained in a high-speed operating range where the engine speed is high. Further, in the vicinity of the upper opening of each secondary intake passage 13b, a control valve 15 that closes this passage when the engine speed is low and opens when the engine speed is high is installed on the valve shaft 1.
It is rotatably attached via 6. This valve shaft 16
In order to interlock each control valve 15, the intake passage block l passes through all the secondary intake passages 13b.
3, and is configured to be driven by an actuator 17. This actuator 17 is operated by the intake negative pressure of the engine 1 or operated by the engine control computer according to the engine speed, and is installed below the surge tank 14 in the V-shaped space. has been done. The primary intake passage 13a has a larger inclination angle than the secondary intake passage 13b upward from the cylinder,
It extends so as to bypass the valve shaft 16. In this embodiment, when the intake passage block 13 is attached to the engine 1, it is bent from the connecting portion with the primary port 5 almost directly upward.

The surge tank 14 is formed long along the longitudinal direction of a crankshaft (not shown), and has cylinder rows 2 inside.
A partition plate 14a is integrally provided to define the interior of the surge tank 14 into two air chambers, an A chamber and a B chamber, corresponding to the cylinder rows 3.

Further, the intake pipe 1 is provided at the bottom of the surge tank 14.
2 and the air chambers A and B, and a secondary intake passage 13b of the intake passage BROLAC 13.
An opening 14c communicating with is provided. Reference numeral 18 denotes a primary intake passage for the surge tank 14, and the primary intake passages 18 have a total of eight passages, one for each cylinder, and are arranged around the outside of the surge tank 14 to obtain a predetermined length. The surge tank 14 is integrally provided with the surge tank 14 and communicates with the primary intake passage 13a of the intake passage block 13.
They are each opened at the bottom. Of these primary intake passages 18°18..., the cylinders 2a, 2
d, 3a, and 3d communicate with the nearest air chamber of the two air chambers A and B in the surge tank 14 through the longitudinal side (front or rear) of the surge tank 14. has been done. That is, cylinder 2a.

The air chamber 2d communicates with the air chamber A located on the cylinder row 2 side, and the air chamber B that communicates with the cylinders 3a and 3d communicates with the air chamber B located on the cylinder row 3 side. Also, the primary intake passage 18 that communicates with the cylinders 2b, 2c, 3b, and 3C passes through the upper part of the surge tank 14 and is connected to the air chamber located on the other cylinder row side of the two air chambers A and B. Each is connected. That is, those that communicate with the cylinders 2b and 2c are connected to the air chamber B located on the side of the cylinder row 3 opposite to the cylinder row 2, and those that are connected to the cylinders 3b and 3c are connected to the cylinder row 3.
It communicates with the air chamber A located on the side of the cylinder row 2 facing the cylinder row 2. The length of each primary intake passage 18 described above is the sum of the length of the primary intake passage 13a in the intake passage block 13, and the effect of inertial supercharging is determined in the low-speed operating range where the engine speed is low. It is set up so that you can get it. As described above, the primary intake passage 18 that communicates with the cylinders in the same cylinder row is divided into air chambers A for each cylinder.

The reason why the structure was adopted is that the ignition order of the engine 1 used in this embodiment was taken into consideration.

The engine 1 of this embodiment is equipped with a crankshaft in which crank pins are provided in four directions, each 90 degrees offset from the center of the crankshaft, and the ignition order is arranged in cylinders 2a-2b-
The order of 3b-2cm3cm3a-2d-3d is adopted. In other words, the primary air passage 18 that communicates with cylinders with consecutive firing order (for example, cylinder 2a and cylinder 2b) is connected to the air chamber located on the opposite side of each cylinder (for example, the one for cylinder 2a is connected to the air chamber). A, cylinder 2b
By communicating the air chamber B) with the air chamber B, intake air can be supplied from separate air chambers to cylinders in which the ignition order is continuous. For this reason, one air chamber of the surge tank 14 can be used alternately with other cylinders for intake without being interfered with by the intake of other cylinders when the engine is running at low speeds. It is possible to suppress intake interference in the low rotation range due to overlapping valve overlap timings.

To attach the intake system of the multi-cylinder ■ type engine configured in this way to the engine 1, first, assemble the intake pipe 12 and the intake passage block 13.13 to the bottom of the surge tank 14 according to Pol) 19.20. Attachment and then tightening of the surge tank 14 and the intake passage block 13 by passing through them and aligning them is done by fixing them to the engine 1 with bolts 21. If the structure is such that the surge tank 14 and the intake passage block I3 are stacked and assembled, not only can the assembly be easily carried out, but also the
, 3 can be rigidly connected to each other, and the engine 1 can be reinforced. Since the control valve 15 is closed when the engine 1 is running at low speed, the intake air supplied to both air chambers A and B of the surge tank 14 is transferred to the primary intake passage 18 of the surge tank 14 and the intake passage block 13.
The air is supplied to each cylinder through the primary intake passage 13a. In addition, since the control valve 15 is open during high rotation, the intake air supplied to both air chambers A and B of the surge tank 14 is added to the above-mentioned primary intake passages 18.13a as well as the relatively short intake air It also passes through the secondary intake passage 13b of the passage block 13 and is supplied to each cylinder.

In this way, when the engine 1 is running at low speeds, air is taken in through the long intake passage, and when the engine 1 is running at high speeds, air is taken in through the short intake passage, thereby maintaining high charging efficiency over a wide speed range from low to high speeds, resulting in high output. can be obtained.

Therefore, as shown in this embodiment, the secondary intake passage 13b is extended obliquely upward from the cylinder, and the primary intake passage 13a is extended upward so as to bypass the axis of the valve shaft 16 of the control valve 15. As a result, the secondary intake passage 13b is communicated with the lower part of the surge tank 14 from below, and the primary intake passage 13a is passed through the side of the surge tank 14 and communicated with the internal air chamber. Therefore, the surge tank 14 can be positioned at a low position within the ■-shaped space while ensuring the length of each intake passage. Furthermore, since the secondary intake passage 13b communicates substantially linearly with the intake passage within the cylinder, intake resistance can be reduced.

In this embodiment, the primary intake passages 18 of the surge tank 14 that communicate with the cylinders 2a, 3b, 3c, and 2d are connected to the air chambers A of the surge tank 14, respectively.
Although an example has been shown in which the cylinders 3a, 2b, 2C, and 3C are connected to the air chamber B, the present invention is not limited to such a limitation, and can be modified according to the ignition order of the engine used. You can change the air chamber to communicate with.

Further, in this embodiment, an example is shown in which the primary intake passage 18 is formed integrally with the surge tank 14, but both may be formed separately.

Further, in this embodiment, an example is shown in which a type 8 cylinder engine is used; however, the same effects as in this embodiment can be obtained with a V-type engine regardless of the number of cylinders.

〔Effect of the invention〕

As explained above, in the intake system for a multi-cylinder V-type engine according to the present invention, the secondary intake passage extends obliquely upward from the cylinder, and the primary intake passage is arranged along the axis of the valve surface movement axis of the control valve. Because it was extended upward as a detour,
The secondary intake passage communicates with the lower part of the surge tank, and the primary intake passage passes through the side of the surge tank and communicates with the internal air chamber. Therefore, since the surge tank can be positioned at a low position within the square space while ensuring the length of each intake passage, the engine as a whole can be made smaller.

Furthermore, since the secondary intake passage communicates substantially linearly with the intake passage within the cylinder, intake resistance can be reduced. Therefore, a large amount of intake air can be supplied when the engine rotates at high speed, and charging efficiency can be increased. Furthermore, since the primary intake passage can be prevented from interfering with the valve surface moving shaft, it is possible to prevent the valve surface moving shaft from penetrating the primary intake passage and increasing intake resistance.

[Brief explanation of drawings]

FIG. 1 is a front view with a cutaway view showing the main parts of the intake system of a multi-cylinder V-type engine according to the present invention, and FIG. 2 is a plan view showing an enlarged view of the intake system of a multi-cylinder V-type engine according to the present invention. , 3rd
The figure is also a side view, and Figure 4 is the TV-rV in Figure 2.
FIG. l...Engine, 2,3...Cylinder row, 5...
・Primary port, 6...Secondary port, 1
0...Intake device, 13...Intake passage block,
13a, 18...Primary intake passage, 13b.
...Secondary intake passage, 14...Surge tank, 14a...Partition plate, 15...Control valve, 1
6... Valve shaft.

Claims (1)

[Claims] A primary port and a secondary port opened on the V-shaped space side of each cylinder in a multi-cylinder V-type engine are communicated with a surge tank in the V-shaped space via a primary intake passage and a secondary intake passage, respectively, and the secondary port In an intake system for a multi-cylinder V-type engine in which a control valve is interposed in a secondary intake passage that closes when the engine speed is low and opens when the engine speed is high, the secondary intake passage extends obliquely upward from the cylinder, and the primary An intake system for a multi-cylinder V-type engine, characterized in that an intake passage extends upwardly so as to bypass the axis of the valve rotation axis of the control valve.