JPH0363671B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an intake system for a V-type engine mainly installed in an automobile.

(Prior Art) As an intake system for a V-type engine consisting of two banks each having a plurality of cylinders, for example, according to FIGS. 1 to 3 of US Pat. No. 3,303,832, two
Two common passages 52 and 54 extending in the crankshaft direction are arranged above the two banks 9 and 9a, and intake passages 55 to 58 and 59 to 62 are branched from the common passages 52 and 54, respectively, and are connected to each other. The common passages 52,
54, an intake system is disclosed which includes a throttle valve 78 and an air cleaner 80, respectively.
According to the intake system having such a configuration, the intake passage to each cylinder has a shape with less curvature, the required passage length required when utilizing intake inertia is secured, and the intake system The entire structure is compact.

On the other hand, when a cooler compressor, power steering pump, or other electrical load acts on an automobile engine when it is idling,
There are idle up systems that increase engine speed to prevent engine stalling, fast idle systems that promote warm-up by increasing idle speed during cold starts, mainly in the case of electronic fuel control engines, and In some cases, an idle control system or the like is provided to perform comprehensive control. All of these systems have a bypass passage in the intake passage that bypasses the throttle valve, and a control valve on the bypass passage to supply a controlled amount of air to the cylinder according to the operating state during idle. By doing so,
It is designed to control the idle speed.

However, when this type of system is applied to a V-type engine having two intake passages as described above, a bypass passage for bypassing the throttle valve is provided in each of both intake passages, and a bypass passage for bypassing the throttle valve is provided in each of both intake passages. Because it must be equipped with a control valve,
The structure becomes significantly more complex, and it is difficult to precisely match the opening degrees of both control valves, resulting in differences in the amount of air supplied to each cylinder during idle.
A problem arises in that the combustion state varies from cylinder to cylinder.

(Object of the Invention) The present invention deals with the above-mentioned problems in the intake system of a V-type engine, and when two systems of intake passages are provided,
As shown in Figs. 1 and 2, we focused on the fact that a balance passage 50 is provided that communicates the intake passages (common passages 52 and 54) on both sides, and by using this balance passage, one bypass passage is created. Bypass air is supplied to the cylinders of both banks via control valves. By adding ingenuity to the arrangement of each passage and control valve, etc.,
The purpose of the present invention is to enable air to be evenly distributed and supplied to each cylinder during idling without complicating the piping structure or increasing the size of the engine.

(Structure of the Invention) The intake system of a V-type engine according to the present invention is angled as follows in order to achieve the above object.

In other words, it is a V-type engine in which two banks each having a plurality of cylinders are arranged at an angle around the crankshaft, and throttle valves are provided in two separate intake passages that communicate with the cylinders of both banks. In the engine, the upstream portions of the above-mentioned two intake passages are gathered together at one side with respect to the crankshaft direction, an air cleaner is provided at the upstream end of the gathering portion, and one intake passage branched from this gathering portion is , the other intake passage extends in the direction perpendicular to the crankshaft along the bank of the side where the air cleaner is arranged, and then extends on the side opposite to the side where the air cleaner is arranged. The throttle valves are provided so as to extend in the crankshaft direction along the banks of the intake passages, and the throttle valves are respectively disposed upstream of the portions of both intake passages that extend in the crankshaft direction. A balance passage is provided for communicating these intake passages downstream of the throttle valve, and a bypass passage is provided for communicating the balance passage and a portion of the other intake passage extending in a direction orthogonal to the crankshaft. A control valve is provided on the bypass passage, located between the two banks, for controlling the amount of air supplied to each cylinder at least during idle. According to such a configuration, bypass air is evenly distributed and supplied to the two intake passages or the cylinders of the banks on both sides by one bypass passage during idle time or the like. And the above balance passage,
Since the bypass passage and the control valve are disposed in a plane above the two banks, an increase in the dimensions in the crankshaft direction and the overall height of the engine is suppressed.

(Example) Hereinafter, an example of the present invention shown in the drawings will be described.

As shown in FIG. 1, a V-type engine 1 has two banks 5, 5 arranged at a constant angle around a crankshaft 4 by one cylinder block 2 and two cylinder heads 3, 3'. ′
has. These banks 5, 5' have a plurality of cylinders 6, 6' arranged along the crankshaft direction (in this embodiment, three cylinders are arranged as shown in FIG. 2).
each cylinder 6,
Pistons 7, 7' are fitted into the pistons 6' and connected to the crankshaft 4 via connecting rods 8, 8'. In addition, each of the above cylinder heads 3,
3' is provided with intake ports 9, 9' and exhaust ports 10, 10' which communicate with the cylinders 6, 6', respectively, and an opening of each port to the cylinders 6, 6' is provided with a movable port. Intake valves 12, 12' and exhaust valves 13, 1 opened and closed by valve mechanisms 11, 11'
3', and both cylinder heads 3,
Exhaust manifolds 14, 14' are mounted on the outer side of the exhaust manifolds 14, 14' for merging a plurality of exhaust ports 10, 10' in each of the exhaust manifolds 14, 14'.

On the other hand, in the space between the two banks 5, 5' or above both banks 5, 5', there is an intake air which supplies combustion air to the cylinders 6, 6' through the above-mentioned intake ports 9, 9'. A device 15 is provided. As shown in FIGS. 1 and 2, this intake device 15 includes two surge tanks 16, 16' which are disposed above the banks 5, 5' substantially in the direction of the crankshaft and have one end closed. A plurality of ports (three ports) are branched from these surge tanks 16, 16', respectively, and intake ports 9', 9' in banks 5', 5 located on opposite sides of each other.
The branch passages 17 and 17' are provided so as to alternately intersect with each other. Throttle bodies 18 and 18' are disposed at the open ends of both surge tanks 16 and 16', respectively, and a branch pipe 19 is connected to the upstream side of the throttle body 18 on one surge tank 16 side. This branch pipe 19 and the throttle body 18' on the other side of the surge tank 16' are connected by a connecting pipe 21 extending in a direction substantially perpendicular to the crankshaft and an L-shaped bent pipe 20. Branch pipe 1
An air cleaner 23 is connected to an end portion of the air filter 9 that opens outward through an air flow meter 22 . As a result, the air is guided from the air cleaner 23 on one side and branched at the branch pipe 19, one of which extends in the crankshaft direction along one bank 5 via the throttle body 18, and the other extends perpendicularly to the crankshaft direction. Stretched and then bent,
Two intake passages are constructed that extend in the crankshaft direction along the other bank 5' via the throttle body 18'. Here, throttle valves 24, 24' are installed in the throttle bodies 18, 18', respectively, and both valves 24,
24' is connected to the interlocking shaft 26 by the throttle lever 25.
It is designed to open and close at the same time via the

In addition, as shown in FIG.
Fuel injection nozzles 27 and 27' are mounted on the nozzles 7 and 17', respectively, so as to face the intake ports 9' and 9 of the cylinder heads 3' and 3 that communicate with these nozzles.
These fuel injection nozzles 27, 27' are pressed and fixed by fuel distribution pipes 28, 28' arranged above the intersection of each branch passage 17, 17', and are also distribution pipe 2
Fuel is distributed and supplied to each nozzle 27, 27' via nozzles 8, 28'.

However, in this intake system 15, as shown in FIG. 2, a balance passage 30 extending in a direction perpendicular to the crankshaft is provided between the surge tanks 16, 16' on both sides on the downstream side of the throttle valves 24, 24'. The passage 30 communicates with both surge tanks 16 and 16' so that the internal pressures are equal, and the balance passage 30
First and second bypass passages 31 and 32 are provided in parallel between the approximately central part of the connection gap 21 and the approximately central part of the connecting gap 21 constituting the intake passage on the side of the surge tank 16', and both bypass passages 31, First and second control valves 33 and 34 are installed on the valve 32, respectively.

The first control valve 33 is an air valve provided as a first idle means in the electronic fuel control system, that is, a means for promoting warm-up at the time of cold start, and as shown in FIGS. It is provided integrally with a thermostat case 35 mounted across the cylinder heads 3 and 3' at 5 and 5'. This thermostat case 35 allows the cooling water discharged from the water jackets of the cylinder heads 3, 3' to flow out from the outlet 35a to the radiator side according to the temperature thereof by the operation of a thermostat 36 installed therein. Then, the air valve (first control valve) 33
is opened and closed by a bimetal 37 that operates by sensing the temperature of the cooling water in the thermostat case 35, and the valve element 33a opens the bypass passage 31 when the temperature of the cooling water is low. A heat coil 38 is wound around the bimetal 37, and when the coil 38 is energized during startup, the bimetal 37 is deformed in the direction of closing the air valve 33, and the valve opening at that time is adjusted to the cooling water temperature. It is now being adjusted accordingly.

The second control valve 34 is provided as an air control valve in the idle up system, and opens the second bypass passage 32 when a cooler compressor, power steering pump, or other electrical load acts. It works like this.

Next, the operation of the above embodiment will be explained.

First, during normal operation, air taken in from the air cleaner 23 passes through the air flow meter 22, and then is branched into two directions by the branch pipe 19, one of which passes through the throttle valve 24, One flows into the tank 16, and the other flows into the surge tank 16' on the other side through the connecting pipe 21, the bending pipe 20, and the throttle valve 24'. Then, the air flows branchingly from both surge tanks 16, 16' into a plurality of branch passages 17, 17', respectively, and passes through each intake port 9', 9 in banks 5', 5 located on opposite sides to the cylinder. 6', 6.

In that case, the surge tanks 16, 16' are
Since they are communicated by the balance passage 30, the pressure in both surge tanks 16, 16' is equal, and therefore air is evenly supplied to each cylinder 6, 6' of banks 5, 5' on both sides. become.

On the other hand, during idling when the throttle valves 24, 24' are closed, especially during a cold start, the air valve (first control valve) 33 in the electronic fuel control system is activated by the bimetal 37 that senses the cooling water temperature. Thus, the first bypass passage 31 is in an open state. Therefore, even though the throttle valves 24, 24' are closed,
From the air cleaner 23 to the air flow meter 22, the branch pipe 19, the communication pipe 21, and the first bypass passage 3
1 and the balance passage 30, air flows into the surge tanks 16, 16' of both banks 5, 5',
Furthermore, it is sucked into each cylinder 6, 6'. At this time,
The air flow meter 22 detects the air flow rate,
By correspondingly increasing the amount of fuel injected from the fuel injection nozzles 27, 27', the idle speed is increased and the engine 1 is warmed up quickly.

Also, when a load from a cooler compressor or the like is applied during idle, the second control valve 34 on the second bypass passage 32 opens, allowing air sucked from the air cleaner 23 to flow through the communication pipe 21.
from the second bypass passage 32 and the balance passage 30
through the surge tanks 16 and 1 of both banks 5 and 5'
6' or each cylinder 6, 6', and the idle speed is increased in the same manner as in the above case.

However, when air is supplied to the cylinders 6, 6' by bypassing the throttle valves 24, 24' during idle as described above, the two banks 5,
5', two systems of intake passages are provided, each consisting of a surge tank 16, 16' and each branch passage 17, 17', each having a throttle valve 24, 24'. A bypass passage 3 is connected to a balance passage 30 that communicates both surge tongues 16, 16' from the connecting pipe 21 on the upstream side of the throttle valve 24' that constitutes the intake passage of one system.
1, 32, one bypass passage 31 or 32 and one control valve 33 on the passage.
or 34 to bypass air to both banks 5,
5' cylinders 6, 6', and each cylinder 6, 6' can be supplied from one bypass passage.
Since air is distributed and supplied to each cylinder 6, 6'
The amount of air supplied to the two becomes approximately equal.

In particular, the balance passage 30 is provided between the surge tanks 16 and 16' on both sides in a direction perpendicular to the crankshaft, and the bypass passage 3
Reference numerals 1 and 32 denote a connecting pipe 21 extending in a direction perpendicular to the balance passage 30 and the crankshaft.
and these bypass passages 3
Since the control valves 33 and 34 are arranged above the balance passage 30, the bypass passage 31, and
32 and the control valves 33, 34 are both arranged in a plane above the banks 5, 5' on both sides, thus suppressing an increase in the dimensions and overall height of the engine in the crankshaft direction. It becomes.

In this embodiment, first and second bypass passages 31 and 32 are provided, and the first and second bypass passages 31 and 32 are provided respectively.
Although control valves 33 and 34 are installed, these are not provided corresponding to the two throttle valves 24 and 24', but both bypass passages 31 and 32 or control valves 33 and 34 are provided respectively. It independently performs a bypass action on the two throttle valves 24, 24'.

In addition, in the case of an engine equipped with an idle control system that comprehensively controls the idle speed during warm-up or load application, one intake passage of the intake device 15a is configured as shown in FIG. A bypass passage that simultaneously bypasses the two throttle valves 24a and 24a' is provided between the connecting pipe 21a extending perpendicular to the crankshaft and the balance passage 30a that communicates the surge tanks 16a and 16a' on both sides. 31a, and one air control valve 33a is provided on the bypass passage 31a.

Also in this case, the bypass air is evenly supplied to the cylinders of both banks, and the balance passage 30a, bypass passage 31a, control valve 33a, etc. are arranged in a plane above between the two banks, so that the engine This suppresses increases in the dimensions in the crankshaft direction and overall height.

Further, although not shown, the bypass passage may be provided with an idle screw for setting an initial value of the idle rotation speed if necessary.

Further, the present invention provides the intake device 1 shown in the above embodiments.
The branch passages 17, 17' branched from the surge tanks 16, 16' on both sides are not limited to those shown in FIG. The surge tank 16 located on the same side as the intake device 15b shown in FIG.
b, 16b' and banks 5, 5' are branch passage 1, respectively.
The same applies to those connected by 7b and 17b'. Also in this case, a bypass connects the balance passage 30b that communicates both surge tanks 16b, 16b' with the connecting pipe 21b that extends in a direction perpendicular to the crankshaft on the upstream side of the throttle valve 24b' in one intake passage. A passage 31b is provided, and an air control valve 33b is installed on the bypass passage 31b.

(Effects of the Invention) As described above, according to the present invention, there are provided two banks each having a plurality of cylinders, and two separate systems of intake passages each having a throttle valve corresponding to each bank. A V-type engine is equipped with two throttle valves: a bypass passage that bypasses the throttle valve to supply air to each cylinder during idle, etc., and a control valve that controls the amount of bypass air. Nevertheless, one of each will be sufficient. This simplifies the piping and other structures compared to the case where each throttle valve has a bypass passage and a control valve, and the opening degree of the control valve varies, so the amount of bypass air is reduced between the cylinders of both banks. This solves the problem of non-uniform combustion in the cylinders and equalizes the combustion state in each cylinder.

In addition, since the balance passage that communicates the downstream sides of the throttle valves in both intake passages, the bypass passage, and the control valves on the passage are arranged in a plane above the two banks, the direction of the engine crankshaft is Increases in size and overall height are suppressed, and the intake system for this type of engine can be configured compactly.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional rear view of a V-type engine showing an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is an enlarged longitudinal sectional front view of main parts taken along the line - Fig. 2, and Fig. 4 is FIG. 3 is an enlarged sectional view of the main part taken along the line 3--, and FIGS. 5 and 6 are a plan view and a rear view of the main part showing other embodiments, respectively. 1... Engine, 4... Crankshaft, 5, 5'
...Bank, 6,6'...Cylinder, 15,15
a, 15b...Intake device, 16, 16', 16a,
16a', 16b, 16b'...Intake passage (surge tank), 24, 24', 24a, 24a', 24b,
24b'... Throttle valve, 30, 30a, 3
0b... Balance passage, 31, 32, 31a, 3
1b... Bypass passage, 33, 34, 33a, 3
3b...Control valve.

Claims (1)

[Claims] 1 A V-type engine in which two banks each having a plurality of cylinders are arranged at an angle around the crankshaft, and two separate intake passages leading to the cylinders of both banks are each equipped with a throttle valve. In the intake device, the upstream portions of the intake passages of the two systems are gathered at one side with respect to the crankshaft direction, and an air cleaner is provided at the upstream end of the gathering portion, and the air cleaner is branched from the gathering portion. One of the intake passages extends in the direction of the crankshaft along the bank of the side where the air cleaner is arranged, and the other intake passage extends in a direction perpendicular to the crankshaft and then connects to the side where the air cleaner is arranged. The throttle valves extend in the crankshaft direction along the bank on the opposite side, and are respectively disposed at upstream portions of the portions of both intake passages that extend in the crankshaft direction; A balance passage is provided for communication on the downstream side of the intake passage, and a bypass passage is provided for communication between the balance passage and a portion of the other intake passage extending in a direction perpendicular to the crankshaft,
An intake system for a V-type engine, characterized in that a control valve is provided on the bypass passage, the control valve being located between the two banks and controlling the amount of air supplied to each cylinder at least during idle.