JPH0738661Y2 - Engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an intake device having a bypass passage that bypasses a throttle valve in a V-type engine.

(Prior Art) Conventionally, for supplying intake air to each cylinder of a multi-cylinder engine, the cylinder group is divided into two groups, the inside of the surge tank is similarly divided, and both spaces in the surge tank are divided. The structure that connects the bypass passage that introduces intake air by bypassing the throttle valve at the time of idling while forming a communication passage that connects It is publicly known as seen in Japanese Laid-Open Publication No. 61-84133.

The bypass passage is configured to supply the intake air to the cylinder groups on both sides from the communication passage in order to equalize the distribution of intake air between the cylinder groups during idling.

(Problems to be solved by the invention) However, in the above serial engine,
It can be configured by installing a surge tank in the cylinder arrangement direction and dividing the inside into front and rear, but when applied to a V-type engine, it is difficult to configure while satisfying the requirement to suppress the overall height of the engine to be low. It will be.

That is, in the V-type engine, the intake passages are connected to the banks on both sides, they are gathered on the upstream side, and the throttle valve is provided on the upstream side to adjust the intake amount. However, due to the layout of the intake passages as a whole, there are problems that the bypass passages become long and it is difficult to construct a compact intake system.

In view of the above circumstances, the present invention provides an intake system for an engine, in which a bypass passage for bypassing a throttle valve is shortened while ensuring a supercharging action due to a dynamic effect of intake and an intake system is configured compactly. The purpose is to do.

(Means for Solving the Problems) In order to achieve the above object, an intake system for an engine of the present invention is a V-type engine in which an intake collecting section is formed for each bank, and a resonance intake upstream of both intake collecting sections. The passage is formed to extend to one side in the engine axial direction and is connected to a common throttle body, while the communication passage that connects the intake collecting portions on both sides to each other is provided to one side in the same engine axial direction as the throttle body. It is arranged such that the downstream end of the bypass passage bypassing the throttle valve arranged in the throttle body is connected and opened to the communication passage.

(Operation) In the intake system as described above, in the V-type engine, the cylinders in which intake is not continuous in each bank are connected and collected to the respective intake collecting portions, and the resonance intake passages on the upstream side of both intake collecting portions are arranged in the engine axial direction. It is formed by extending to one side, and a communicating passage that connects both intake collecting portions is provided to obtain a supercharging action by the dynamic effect of intake air, and both the throttle body and the communicating passage are provided on one side in the engine axial direction. The throttle bypass passage having one end connected to the upstream side of the throttle valve is open-connected to the communication passage to shorten the length of the bypass passage and equalize the bypass air at the same time;
It is less affected by blow-by gas and reduces the intrusion of foreign matter such as carbon.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 respectively show a schematic plan structure and a front structure of a horizontal V-type engine.

The 6-cylinder V-type engine E of this example is placed laterally in the front-rear direction of the vehicle, and the engine main body 1 has front and rear cylinder heads 3a on the front and rear sides at a predetermined angle on both sides of the cylinder block 2 at the lower center. , 3b are arranged in the front side bank 1A and the rear side bank 1B, the front side bank 1A is provided with the first, third and fifth cylinders, and the rear side bank 1B is provided with the second and fourth cylinders. , 6 cylinders are arranged. Further, each cylinder is inhaled and ignited in the order of the first to sixth cylinders,
The intake sequence is not continuous between the cylinders in 1A and 1B.

Intake air is supplied to each cylinder of the banks 1A, 1B on both sides by the intake device 4, and the cylinder heads 3a, 1B of both banks 1A, 1B are supplied.
The intake ports (not shown) of the cylinders are opened so as to face each other on the inner surface side of 3b, and the intake device 4 includes the cylinder head.
The downstream side of the throttle body 6 is integrally formed by the intake manifold 5 whose downstream side is connected to 3a and 3b.

The intake manifold 5 includes a pair of first and second collective intake pipes 7 arranged parallel to each other in the engine axial direction (vertical direction in FIG. 1) along the cylinder row direction between the banks 1A and 1B.
The first intake manifold 7a is provided with a first intake manifold 11a and the second intake manifold 7b is formed with a second intake manifold 11b. The first collective intake pipe 7a is arranged at a substantially central portion between the banks 1A and 1B, and the second collective intake pipe 7a is provided.
b is arranged on the inner side of the second bank 1B.

On the lower surface of the first collective intake pipe 7a, there are three first independent intake pipes.
, And three second independent intake pipes 8b are integrally joined to the lower surface of the second collective intake pipe 7b. Each independent intake pipe
The lower ends of 8a and 8b are fastened to the respective cylinder heads 3a and 3b, and the first and second independent intake passages 12a, which supply the intake air from the respective intake collecting portions 11a and 11b to the respective cylinders of the banks 1A and 1B, respectively. 12b is formed.

The end of the first collective intake pipe 7a on one side (downward in FIG. 1) in the engine axial direction and the end of the second collective intake pipe 7b on the same direction side are connected by a communication passage 20. ing. A part of the communication passage 20 is formed by fastening a cover member 21 formed separately. Further, the open / close valve 19 is provided in the communication passage 20.
Is provided, and the communication state is opened and closed. FIG. 2 shows a state in which the cover member 21 is removed, and the first member on both sides is shown.
Also, the opening 22 communicating with the second collective intake pipe 7a, 7b is integrally opened, and the flange 22a on the outer periphery of the opening is fastened to the peripheral edge of the cover member 21 having a concave inner surface to form the opening. A communication passage 20 that connects the intake air collecting portions 11a and 11b on both sides is formed by 22 and the inner space of the cover member 21.

Further, upstream first and second resonance intake pipes 9a, 9b are connected to the first and second collective intake pipes 7a, 7b at positions displaced from the central portion to the side opposite to the communication passage 20. First and second resonance intake passages 13a and 13b are formed inside. The first resonance intake pipe 9a extends from the first collective intake pipe 7a to above the second collective intake pipe 7b, and is curved above the second bank 1B in one axial direction (downward in the figure) of the communication passage 20. It is extended to the formation side. The second resonance intake pipe 9b extends outward from the second collective intake pipe 7b above the second bank 1B,
It is curved and extends in the output shaft direction (downward in the figure).

The upstream ends of both resonance intake pipes 9a and 9b are connected to a common throttle body 6. The throttle body 6 is provided with a single throttle valve 23, and a portion immediately downstream of the throttle body 6 is branched into first and second resonance intake pipes 9a, 9b vertically and forward and backward, and both resonance intake pipes are branched at this portion. 9a and 9b are connected to each other to obtain a low speed resonance action. An air pipe 14 is connected to the upstream side of the throttle body 6 and communicates with an air cleaner 15 to introduce intake air.

A plug hole 24 for attaching an ignition plug (not shown) to each cylinder is formed in each of the cylinder heads 3a and 3b.

Further, a throttle bypass passage 17 that bypasses the throttle valve 23 of the throttle body 6 is provided. The upstream end of the throttle bypass passage 17 is connected to the throttle body 6 on the upstream side of the throttle valve 23, while the downstream end is connected to the intake passage near the communication passage 20, and the bypass valve 18 is connected to the throttle bypass passage 17. It is installed.

That is, the lower surface of the throttle body 6 has a throttle valve.
A bypass valve 18 that opens and closes a bypass passage 17 that is open on the upstream side of 23 is installed, a connection pipe 17a is provided at the lower end of this bypass valve 18, and a hose 17b is connected to this. A connecting pipe 17c is also provided below the opening 22 of the one-collecting intake pipe 7a, and the other end of the hose 17b is connected to the connecting pipe 17c. Bypass valve 18 of the throttle bypass passage 17
Is for controlling the idle speed by adjusting the amount of bypass air introduced when the throttle valve 23 is in the fully closed state at idle.

Next, the opening / closing valve 19 of the communication passage 20 is controlled to be opened / closed by an actuator (not shown) according to an operating state, and the operating region of the opening / closing control is shown in FIG. First, in the low load area (including the idle area) where the required output is low and the output increase due to the dynamic supercharging effect is not necessary,
The on-off valve 19 is opened. This allows the throttle valve 23
In the idle area where is closed, the on-off valve 19 opens and the bypass air supplied by the throttle bypass passage 17 is
Intake manifolds 11a, 11b on both sides through the open communication passage 20
And is supplied to each cylinder.

Further, in order to obtain a dynamic effect, in the high load region in the low speed range where the engine speed is equal to or lower than the set value No, the communication opening / closing valve 19 is closed to lengthen the pressure wave propagation path to obtain the low speed side tuning point, At this time, the torque curve I has a peak value at the tuning point and has a characteristic that decreases before and after that. On the other hand, in the high speed range where the engine speed exceeds the set value No, the on-off valve 19 opens and the pressure wave propagation path is shortened to obtain the high speed side tuning point, and the torque curve II at this time is also the tuning point. It shows a peak value and has characteristics that decrease before and after that. And
The intersection of the torque curves I and II represents the set value No.

The tuning point in each state in the above example is determined by the substantial passage diameter and length of each intake system, and the intake collecting portions 11a and 11b and the independent intake passages 12a and 12a.
b, the natural frequency of the intake system is set according to the diameter and length of the resonance intake passages 13a, 13b, etc., so that dynamic supercharging can be obtained in each state in the rotation region.

According to the above-described embodiment, since the communication passage 20 and the throttle body 6 are arranged in the same direction, the total length of the throttle bypass passage 17 is shortened, and the bypass air passage is connected to the downstream side portion of the bypass passage. Control responsiveness is improved. Furthermore, the supply to the communication passage 20 improves the distribution of intake air to the banks 1A and 1B on both sides, and is less affected by the blow-by gas passage (not shown) connected immediately downstream of the throttle valve 23. And so on.

Further, in the above-described embodiment, the opening / closing valve 19 of the communication passage 20 is closed in the high load low speed range of the engine, and the first and second intake collecting portions 11a, 11b in the collecting intake pipes 7a, 7b have the first and second resonances. The intake passages 13a and 13b communicate with each other at an upstream communication portion near the throttle body 6. In this state, each bank 1A or 1B
In this case, the tuning frequency of the intake resonance generated between the cylinders becomes low, and as a result, the intake air is resonantly supercharged in the low speed region of the engine as shown by the torque curve I in FIG. That is, the negative pressure wave of intake air generated near the intake port 6 at the beginning of the intake stroke of each cylinder of each bank 1A, 1B is generated by each of the independent intake passages 12
After propagating through the a and 12b and the intake collecting portions 11a and 11b, they are reflected by the upstream end communicating portions of the resonance intake passages 13a and 13b and are inverted into a positive pressure wave, and the positive pressure wave is generated in the same bank 1A, Resonance supercharging of intake air is performed by acting at the end of the intake stroke of the other cylinder of 1B.

On the other hand, when shifting to the high speed range, the on-off valve 19 is opened and the communication passage 20 is opened, so that both intake collecting portions 11a, 11b are also communicated by the communication passage 20. In this state, the negative pressure wave of the propagating intake air is reflected in the communication passage 20 that is close in distance and is inverted to the positive pressure wave, so that the resonance frequency increases and the engine speed increases as shown by the torque curve II in FIG. It is possible to effectively supercharge intake air even in the high speed range. When the communication passage 20 is opened, the intake air is supplied to the cylinders of the banks 1A and 1B from the intake collecting portions 11a and 11b corresponding to the banks 1A and 1B, and the intake air is supplied to the opposite side through the communication passage 20. Intake collection part 11
It is also supplied from b and 11a, and the intake charge amount in the high speed range can be increased.

In this case, since both the resonance intake passages 13a and 13b are arranged side by side on the second bank 1B of the engine 1, even if there is a restriction in the engine room such as the vehicle body bonnet line L,
The effective length of the resonance intake passages 13a and 13b can be set long. Further, the effective lengths of the two resonance intake passages 13a and 13b and the degree of bending thereof can be substantially equalized, the intake resistance in both the resonance intake passages 13a and 13b can be made equal, and the cylinders of both banks 1A and 1B can be made equal. The intake charge efficiency can be equalized.

It should be noted that in the above-described embodiment, the intake collecting portion 1 is provided in the collecting intake pipes 7a and 7b.
Although 1a and 11b are formed, a surge tank having a certain volume may be formed at the intake collecting portion. Further, the connection position of the downstream end of the throttle bypass passage 17 may be a portion of another communication passage such as a cover member in addition to the position of the above example, and the design is appropriately changed in relation to peripheral devices.

Further, in the above embodiment, the upstream side of both resonance intake passages 13a, 13b is made to communicate immediately downstream of the throttle body 6, but two throttle valves are provided and the communication portion of both resonance intake passages is made upstream thereof. May be provided and can be arbitrarily set according to the set rotational speed at which resonance occurs.

(Effect of the Invention) According to the present invention as described above, an intake collecting portion is provided for each bank of a V-type engine, and a resonance intake passage upstream of both intake collecting portions extends to one side in the engine axial direction. In addition, a communication passage that connects both intake collecting portions is provided to obtain a supercharging action by the dynamic effect of intake air, and both the throttle body and the communication passage are arranged on one side in the engine axial direction. Since the downstream end of the throttle bypass passage connected to the throttle body is open-connected to the communication passage, the length of the bypass passage can be shortened, and the supply of bypass air can be made uniform. In addition, the influence of blow-by gas is less likely to occur, and the intrusion of foreign matter such as carbon can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an intake device for a V-6 cylinder engine according to an embodiment of the present invention, FIG. 2 is a front view of relevant parts, and FIG. 3 is a torque curve showing an example of opening / closing operation depending on the operating state of the opening / closing valve. It is a characteristic view shown with. E ... Engine, 1 ... Engine body, 1A, 1B ... Bank, 3
a, 3b ... Cylinder head, 4 ... Intake device, 5 ... Intake manifold, 6 ... Throttle body, 7a, 7b ... Collective intake pipe, 8a, 8b ... Independent intake pipe, 9a, 9b ... Resonance Intake pipe, 11a, 11b ... Intake air collecting part, 12a, 12b ... Independent intake passage, 13a, 13b ... Resonance intake passage, 17 ... Bypass passage, 1
8 …… Bypass valve, 19 …… Open / close valve, 20 …… Communication passage, 2
1 …… Cover member, 23 …… Throttle valve.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F02M 69/32

Claims (1)

[Scope of utility model registration request] 1. A V-type engine intake device having an intake collecting portion formed for each bank, wherein a resonance intake passage upstream of both intake collecting portions is formed to extend to one side in an engine axial direction and is common. While being connected to the throttle body, a communication passage that connects the intake collecting portions on both sides to each other is disposed on one side in the same engine axial direction as the throttle body,
An intake device for an engine, wherein a downstream end of a bypass passage that bypasses a throttle valve disposed in the throttle body is connected and opened to the communication passage.