WO2022209880A1

WO2022209880A1 - Air suction device for internal combustion engine

Info

Publication number: WO2022209880A1
Application number: PCT/JP2022/011754
Authority: WO
Inventors: 洋平中村; 達也川手
Original assignee: 本田技研工業株式会社
Priority date: 2021-03-31
Filing date: 2022-03-15
Publication date: 2022-10-06

Abstract

In an internal combustion engine that has an air intake passage 80, an air intake passage pipe 6, a throttle body 7, a throttle valve 75, and a resonator 100: the air intake passage pipe 6 is disposed on the downstream side of the throttle body 7; the air intake passage 80 comprises a partitioning wall 81 that divides the air intake passage 80 into a tumble flow path 80A and a main flow path 80B; and the air intake passage pipe 6 has a communication hole 102 that is positioned on the downstream side of the throttle valve 75 and opens to a communication pipe 101 connecting the resonator 100 and the air intake passage 80. This air intake device for internal combustion engines prevents reduction in flow through the air intake passage, strengthens tumble flow, and increases fuel efficiency.　

Description

Intake system for internal combustion engine

The present invention relates to an intake system for an internal combustion engine, in which an intake passage is partitioned into a main flow passage and a tumble flow passage, and a resonator communicating with the intake passage is provided.

For example, Patent Document 1 discloses a structure in which an intake passage of an internal combustion engine is partitioned into a main flow path and a tumble flow path to generate a tumble flow.
The intake system disclosed in Patent Document 1 does not include a resonator that communicates with the intake passage, and the amount of intake air remaining in the intake port is small. The squeezed opening is in a small state. Therefore, in the intake stroke from when the intake valve opens to when it closes, the volume on the intake port side increases as the piston descends. As a result, the intake port suddenly becomes negative pressure, weakening the flow in the intake passage, and there is a problem that the tumble flow is reduced.

Japanese Patent Application Publication No. 2016-070166

The present invention has been made in view of the above problems, and includes an intake passage that introduces intake air into a combustion chamber, an intake passage pipe that is a part of the intake passage, and an intake passage pipe that introduces intake air into the intake passage pipe. An intake structure for an internal combustion engine having a throttle body, a throttle valve arranged inside the throttle body for controlling the opening of the intake passage, and a resonator,
The intake passage pipe is disposed downstream of the throttle body and has a partition wall that divides the intake passage into a tumble flow passage and a main flow passage along the longitudinal direction, which is the inflow direction of the intake air,
The intake passage pipe is positioned downstream of the throttle valve and has a communication hole opening to a communication pipe that connects the resonator and the intake passage.

According to the above configuration, the intake passage pipe has a communication hole communicating with the interior of the resonator on the downstream side of the throttle valve, and even when the throttle valve is throttled during operation in a low load region of the internal combustion engine, Since the intake air flows into the intake passage from the resonator arranged downstream of the throttle valve, the flow in the intake passage is not lowered, and the tumble flow can be strengthened to improve the combustion efficiency. .

In the above configuration, the communication hole may be positioned on the tumble flow path side portion of the intake passage pipe.

According to the above configuration, the flow of the tumble flow is further enhanced by the inflow of air from the resonator to the tumble flow path side, further improving the combustion efficiency.

In the above configuration, the communication hole may be arranged between the downstream end of the throttle body and the upstream end of the partition wall.

According to the above configuration, since the communication hole communicating with the resonator is arranged at a location away from the internal combustion engine, which is a heat-generating portion, even if airflow with a relatively high temperature flows into the intake passage, Heat is not transmitted to the communicating pipe, and the effect of exhaust heat from the internal combustion engine is reduced, thereby preventing reduction in intake efficiency.

In the above configuration, the intake passage pipe may have a valve at a position close to the upstream end of the partition wall for changing the amount of intake air in the tumble flow path by means of a rotatable plate-like valve body.

According to the above configuration, the amount of intake air flowing through the tumble flow path can be controlled by the plate-shaped valve body, and the flow of the tumble flow can be strengthened even in the low-load region of the internal combustion engine, improving combustion efficiency.

In the above configuration, the intake passage may have a mounting portion to which one end of the communication pipe is mounted, and the mounting portion and the intake passage pipe may be integrated.

According to the above configuration, since the mounting portion to which the communicating pipe is mounted and the intake passage pipe are integral parts, fixing parts for fixing the mounting portion to the intake passage pipe are not required, thereby preventing an increase in the number of parts, Processing time can be reduced.

In the above configuration, the communication hole may be located downstream of the downstream end of the connection member that connects the throttle body and the intake passage pipe.

According to the above configuration, by providing the communication hole at a position that does not overlap the mounting surface of the connection member, the communication hole and the mounting portion can be prevented from interfering with the fixing member, and the assembling property can be improved.

In the above configuration, the communication hole may be positioned so as not to overlap a fixing member for fastening the intake passage pipe to the cylinder head when viewed from the mounting direction of the fixing member.

According to the above configuration, by providing the communication hole at a position that does not overlap with the fixing member when viewed in the mounting direction of the fixing member, the communication hole can be prevented from interfering with the fixing member, and the assembling property can be improved.

The configuration includes a fuel injection valve that injects fuel toward the interior of the intake passage,
A notch portion is provided in the inner wall of the intake passage pipe from the upstream side toward the downstream side in the intake air flow direction,
The communication hole may be provided at a position overlapping with the notch.

According to the above configuration, it is possible to prevent the injected fuel from accumulating in the communication hole and the notch.

According to the present invention, since the intake passage pipe has the communication hole communicating with the inside of the resonator on the downstream side of the throttle valve, when the throttle valve is throttled when the internal combustion engine is operating in a low load range, Also, since the intake air flows into the intake passage from the resonator located downstream of the throttle valve, the flow in the intake passage is not reduced, and the tumble flow is strengthened to improve the combustion efficiency. can.

1 is a right side view of a motorcycle equipped with a power unit having an intake structure for an internal combustion engine according to Embodiment 1 of the present invention. 2 is a rear right side surface of the motorcycle of FIG. 1 with a body cover removed. FIG. 3 is a side cross-sectional view of a power unit taken out from FIG. 2 and shown in substantially the same orientation as that shown in FIG. 2 and having an intake structure for an internal combustion engine according to Embodiment 1; 4 is an enlarged view of a main part of FIG. 3; FIG. 5 is an enlarged view of a main part of FIG. 4; FIG. FIG. 6 is an enlarged cross-sectional perspective view of a main part of FIG. 5; FIG. 4 is a cross-sectional view of the inlet pipe, the communicating pipe, and the resonator cut at a position where the communicating hole passes; Fig. 3 is a left side view showing the vicinity of the throttle body and the inlet pipe; Fig. 3 is a perspective view showing the periphery of an inlet pipe mounting portion; It is the figure which looked at the periphery of a communicating hole from the inside of an inlet pipe. FIG. 4 is a schematic diagram of an intake passage showing a region downstream of a throttle valve; FIG. 12 shows the pressure variation at the point indicated in FIG. 11 during the cycle of the internal combustion engine;

An intake system for an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 12. FIG.
It should be noted that the directions of front, back, left, right, up and down in the description of this specification and the scope of the claims follow the directions of the vehicle when the power unit equipped with the intake device for the internal combustion engine according to the present embodiment is mounted on the vehicle. do. In this embodiment, the vehicle is a small vehicle, specifically a motorcycle. However, regarding the intake passage 70 of the throttle body 7 and the intake passage 80, the upper side of the partition portion 81 as a partition dividing them along the intake air flow direction F is described as the "upper" side, and the lower side is described as the "lower" side. do. In the drawing, an arrow FR indicates the front of the vehicle, LH the left of the vehicle, RH the right of the vehicle, and UP the upper of the vehicle.

FIG. 1 shows the right side of a motorcycle 1 equipped with a power unit 3 equipped with an intake device for an internal combustion engine according to an embodiment of the present invention. 2 shows the rear right side of the motorcycle 1 of FIG. 1 with the body cover 10 removed.

A motorcycle 1 according to the present embodiment is a so-called scooter type motorcycle, in which a vehicle front portion 1A and a vehicle rear portion 1B are connected via a low floor portion 1C. , generally comprising a down tube 21 and a main pipe 22 (see FIG. 2).
That is, a down tube 21 extends downward from a head pipe 20 in the front portion 1A of the vehicle body, and the down tube 21 bends horizontally at its lower end to extend rearward under the floor portion 1C, and as shown in FIG. A pair of left and right main pipes 22 are connected via a connecting frame 23 arranged in the width direction of the vehicle. It bends and extends backward.

A storage box 11 and a fuel tank 12 are supported above the inclined portion 22a of the main pipe 22, and the storage box 11 and the fuel tank 12 are closed by an occupant seat 13 mounted thereabove. A vehicle body cover 10 covers the lower part of the passenger seat 13 including the fuel tank 12 .
On the other hand, in the front part 1A of the vehicle body, a handlebar 14 is provided upwardly while being pivotally supported by a head pipe 20, and a front fork 15 extends downward, and a front wheel 16 is pivotally supported at the lower end thereof.

As shown in FIG. 2, the rear right side of the motorcycle 1 with the vehicle body cover 10 removed, a bracket 24 is protruded near the lower end of the inclined portion 22a of the main pipe 22, and the power unit is connected to the bracket 24 via a link member 25. 3 is connected and supported so as to be able to swing.
The front portion of the power unit 3 is a single-cylinder four-stroke cycle air-cooled internal combustion engine (hereinafter simply referred to as the "internal combustion engine") 30, and a crankshaft is mounted in the front portion of the power unit case 50 constituting the crankcase portion 50a. 51 is arranged in the vehicle width direction and rotatably supported, and the end of the hanger arm 52 protruding forward from the lower end of the power unit case 50 is in a posture in which the cylinder axis C is greatly inclined forward to a substantially horizontal state. are connected via a link member 25 attached to a bracket 24 of the main pipe 22 so as to be vertically swingable.

In the power unit 3, a cylinder block 31, a cylinder head 32, and a cylinder head cover 33, which constitute the internal combustion engine 30, are stacked in order on the front portion of the power unit case 50, which constitutes the crankcase portion 50a. In addition to being fastened, a power transmission case portion 55 equipped with a belt-type continuously variable transmission and the like extends integrally from the crankcase portion 50a to the rear left side, and a rear axle 56, which is the output shaft of the power unit 3, is provided at its rear portion. and the rear wheels 17 are attached.
That is, the power unit 3 is a so-called swing unit, and a rear cushion (not shown) is interposed between the power transmission case portion 55 at the rear of the power unit 3 and the rear of the main pipe 22 .

As shown in FIG. 2, in the upper portion of the power unit 3, the inlet pipe 6 extends from the upper portion of the cylinder head 32 of the internal combustion engine 30, which tilts forward greatly, and curves rearward. is located above the cylinder block 31 , and an air cleaner device 86 connected to the throttle body 7 via a connecting tube 85 is arranged above the power transmission case portion 55 .
On the other hand, an exhaust pipe 38 extending downward from the lower portion of the cylinder head 32 is bent rearward and extends rearward while biased to the right side, and is connected to a muffler 39 on the right side of the rear wheel 17 .

FIG. 3 is a side sectional view of the power unit 3 taken from FIG. 2 and shown in substantially the same orientation as shown in FIG.
The internal combustion engine 30 in the power unit 3 is shown in cross-section of the left half of the cylinder block 31, the cylinder head 32, and the cylinder head cover 33, and the power unit case 50 has a left case half 50L which is a mating surface with a right case half (not shown). 50b is shown facing forward in the drawing.

The power unit case 50 is constructed by combining a left-right split left case half 50L and a right case half (not shown). The half body 50L has a front portion forming the left half of the crankcase portion 50a, and extends rearward to form a long belt (not shown) between the crankshaft 51 and the rear axle 56 of the rear wheel 17. A power transmission case portion 55 is formed to accommodate a transmission including a type continuously variable transmission and a reduction gear mechanism 57 and the like.
The reduction gear mechanism 57 is housed inside the rear right open surface 55R of the power transmission case portion 55 and is covered with a speed reducer case (not shown). The output shaft of the reduction gear mechanism 57 is the rear axle 56 of the rear wheel 17 .
Rotational power of the crankshaft 51 of the crankcase portion 50a of the internal combustion engine 30 is transmitted to the rear wheels 17 through the belt-type continuously variable transmission and the reduction gear mechanism 57 in the power transmission case portion 55. .

A piston 34 that reciprocates in a cylinder bore 31a of the cylinder block 31 is connected by a connecting rod 35 to a crankpin 51a of a crankshaft 51 of the crankcase portion 50a.
A combustion chamber 36 is formed between the top surface 34a of the piston 34 slidably fitted in the cylinder bore 31a of the cylinder block 31 and the combustion chamber ceiling surface 32a of the cylinder head 32 facing the top surface 34a. be.

The internal combustion engine 30 employs a SOHC type two-valve system, and a cylinder head 32 is provided with a valve mechanism 9 . A cylinder head cover 33 is overlaid on the cylinder head 32 so as to cover the valve mechanism 9 .
In order to transmit power to the valve mechanism 9 in the cylinder head cover 33, an endless cam chain (not shown) is provided on one side of the crankcase portion 50a, the cylinder block 31, and the cylinder head 32 in the crankshaft 51 direction. The camshaft 91 and the crankshaft 51 are spanned through a cam chain chamber that does not rotate, and the camshaft 91 rotates in synchronism with the crankshaft 51 at a rotation speed of 1/2.
An ignition plug (not shown) is inserted into the combustion chamber 36 from the opposite side of the cam chain chamber (the other side in the crankshaft 51 direction) of the cylinder head 32 .

As shown in FIG. 3 and FIG. 4, which is an enlarged view of the main part of FIG. 3, in the cylinder head 32 in which the cylinder axis C is substantially horizontal and greatly inclined forward, the intake valve port 40 opens to the combustion chamber ceiling surface 32a. An intake port 42 and an exhaust port 43 extend from the and exhaust valve openings 41 while curving in directions away from each other in the vertical direction.
The upstream end of the intake port 42 opens upward from the cylinder head 32 and is connected to the inlet pipe 6 to form a continuous intake passage 80 . As shown in FIG. 5, a downstream end 7a of the throttle body 7 is connected to an upstream end 6e of the inlet pipe 6 via an insulator 8 as a connecting member.
A downstream end of the exhaust port 43 opens downward in the cylinder head 32 and is connected to an exhaust pipe 38 (see FIG. 2).

As shown in FIG. 4, a cylindrical intake valve guide 44 is integrally fitted to the curved outer wall portion 42a of the intake port 42 in the cylinder head 32, and an intake valve 46 is slidably supported by the intake valve guide 44. opens and closes the intake valve port 40 facing the combustion chamber 36 of the intake port 42 .
Also, an exhaust valve 47 slidably supported by an exhaust valve guide 45 integrally fitted to the curved outer wall portion 43a of the exhaust port 43 in the cylinder head 32 is an exhaust valve opening facing the combustion chamber 36 of the exhaust port 43. Open and close 41.

The intake valve 46 and the exhaust valve 47 are urged upward by a valve spring 48 so that the

head portions

46a and 47a of the intake valve 46 and the exhaust valve 47 close the intake valve port 40 and the exhaust valve port 41 facing the combustion chamber 36. As shown in FIG. 3, stem ends 46b and 47b of the intake valve 46 and the exhaust valve 47 are pushed down by an intake rocker arm 94 and an exhaust rocker arm 95 which contact and oscillate with the intake cam 92 and the exhaust cam 93 of the camshaft 91. , the intake valve 46 and the exhaust valve 47 are opened at a predetermined timing, the intake port 42 and the combustion chamber 36 and the exhaust port 43 and the combustion chamber 36 are communicated, and intake and exhaust are performed at predetermined timing.

In the internal combustion engine 30 as described above, an intake device is configured to give a tumble vortex T, that is, vertical rotation of the fuel-air mixture in the combustion chamber 36 in order to obtain more favorable combustion in the combustion chamber 36 .
That is, the inlet pipe 6 is connected to the upstream end of the intake port 42 of the internal combustion engine 30 through an insulator 61 to form a continuous intake passage 80 having a substantially circular cross section. A throttle body 7 is connected to the upstream side of the inlet pipe 6 via an insulator 8 as a fixing member.
The throttle body 7 has an intake passage 70 with a substantially circular cross section forming part of an intake passage 80 connected to the combustion chamber 36 of the internal combustion engine 30, and an air cleaner device 86 ( (See Fig. 2).

As shown in FIG. 4, the throttle body 7 has a throttle valve 75. The throttle valve 75 is of the butterfly type, and has a throttle valve shaft 76 and a disc-shaped valve body 77 fixed to the throttle valve shaft 76 and rotating integrally therewith. The valve body 77 is fixed to the throttle valve shaft 76 so as to substantially bisect the disk. The valve element 77 is rotatably supported in the throttle body 7 by a throttle valve shaft 76 which is oriented substantially horizontally perpendicular to the intake flow direction F of the intake passage 70, that is, intersects perpendicularly with the central axis of the intake passage 70. ing. The throttle valve 75 is rotated by an instruction of an operator or the like, and variably controls the flow area of the intake passage 70 to change the amount of intake air flowing through the intake passage 70 .

The intake passage 80 continues from the inlet pipe 6 to the intake port 42 and is divided by a partition 81 along the intake flow direction F so that the passing intake air generates a tumbling vortex T in the combustion chamber 36. It is partitioned into a tumble channel 80A and a main channel 80B excluding the tumble channel 80A. The intake passage 80 is partitioned by a partition portion 81 such that the tumble passage 80A is narrower than the main passage 80B.
In the present invention, the "tumble flow path" is an intake air flow path for generating a tumble vortex T in the combustion chamber 36 when the throttle valve 75 is at a low opening, that is, when the internal combustion engine 30 is at a low load.

The lower portion of the intake passage 80 partitioned by the partition portion 81 serves as the tumble passage 80A, and the upper portion thereof serves as the main passage 80B, but the present invention is not limited to their vertical arrangement.
In this specification, "upper" and "lower" with respect to the intake passage 80, the intake passage 70, and the throttle valve 75 mean "up" in the direction of the cylinder head 32 or the cylinder head cover 33 in the direction of the cylinder axis C, and "up" in the direction of the crankshaft 51. is called ``lower,'' and it does not mean ``upper, lower'' in space.

As shown in FIG. 4, the partitioning portion 81 includes an inlet pipe side partitioning portion 81A, an insulator side partitioning portion 81B, and an intake port side partitioning portion 81C positioned continuously from the upstream side to the downstream side of the intake air flow. configured as
A main flow passage 80B on the upper side of the drawing and a tumble flow passage 80A on the lower side of the drawing vertically extend from the inlet pipe 6 to the intake port 42, and the intake passage 80 on the downstream side of the throttle valve 75 is vertically partitioned by the partition portion 81. , each having a substantially semicircular cross section.
The surface of the partition portion 81 in the width direction of the intake passage 80 and the throttle valve shaft 76 are parallel.

Further, as shown in FIG. 4, the downstream end 81b of the partition 81, that is, the downstream end 81b located in the intake port 42 of the cylinder head 32 is directed toward the cylinder block 31 in the cylinder head 32. The end 80Ab of the tumble flow path 80A is bent and integrally formed, and is formed so as to point toward the combustion chamber ceiling surface 32a of the cylinder head 32. As shown in FIG.
Therefore, the intake air flowing through the tumble flow path 80A can pass above the head portion 46a of the intake valve 46 and then flow into the cylinder bore 31a, as indicated by the middle and small arrows in FIG. The tumble vortex T can be easily generated inside. As such, the tumble flow path 80A is configured such that the passing intake air generates the tumble vortex T. As shown in FIG.

As shown in FIG. 5, a tumble control valve 65 is arranged near the upstream end 81a of the partition 81 formed in the inlet pipe 6. As shown in FIG. The tumble control valve 65 has a tumble valve shaft 66 and a tumble valve body 67 fixed to the tumble valve shaft 66 and integrally rotated together.
The tumble valve body 67 is formed in a plate-like semi-disk that closes the opening of the main flow path 80B near the upstream end 81a of the partition portion 81 in the inlet pipe 6. As shown in FIG. A tumble valve shaft 66 is attached to one linear end of the tumble valve body 67 .
The tumble valve shaft 66 is rotatably supported by the inlet pipe 6 so as to be parallel to the plane of the partition 81 in the width direction of the intake passage 80, and is appropriately rotated by an actuator (not shown). As the tumble valve shaft 66 rotates, the tumble valve body 67 also rotates, the opening degree of the main flow path 80B is changed, and as the intake air amount flowing through the main flow path 80B is adjusted, the intake air amount of the tumble flow path 80A is also adjusted. adjusted.
In the present embodiment, the tumble control valve 65 is arranged with an interval from the upstream end 81a of the partition 81, but may be arranged at the upstream end 81aa of the partition 81 on the upstream side.

As shown in FIG. 4 , a fuel injection valve 87 is attached to the throttle body 7 so as to penetrate from the upper outside and is arranged to inject fuel toward the intake passage 80 .
Also attached to the inlet pipe 6 is a fuel injection valve 88 which penetrates the main flow path 80B from the upper outside and is arranged to inject and supply fuel toward the intake valve port 40 . When attaching the fuel injection valve 88 to the inlet pipe 6, in order to prevent the fuel from adhering to the wall surface of the intake passage, it is preferable to attach the fuel injection valve 88 to the side of the main flow passage 80B, which has a larger flow passage cross-sectional area than the tumble flow passage 80A. .
In this embodiment, the

fuel injection valves

88 and 87 are arranged in the inlet pipe 6 and the throttle body 7, but the number of fuel injection valves is not limited to two, and may be, for example, one. Either one of the

fuel injection valves

87 and 88 may be attached. Further, a direct injection structure in which a fuel injection valve is arranged in the cylinder head 32 or the cylinder block 31 to inject fuel into the combustion chamber 36 may be used.

As shown in FIG. 7, the inlet pipe 6 is connected to a resonator 100 via a communicating pipe 101. As shown in FIG.
The inlet pipe 6 is formed with a mounting portion 104 for mounting one end of the communicating pipe 101 so as to protrude from the outer wall surface 6d of the inlet pipe 6 . The attachment portion 104 is formed in a tubular shape and has a communicating passage 104a inside. A collar-shaped portion 104b is formed on the outer surface of the mounting portion 104. As shown in FIG. In the present embodiment, the communication pipe 101 is an integral part that is formed integrally with the inlet pipe 6, but it may be structured to be attached to the inlet pipe 6 separately from the inlet pipe 6.
The inner wall 6c of the inlet pipe 6 is formed with a communication hole 102 opening to the communication passage 104a inside the communication pipe 101. As shown in FIG.
One end 101 a of the communication pipe 101 is connected to a mounting portion 104 projecting from the inlet pipe 6 , and the other end 101 b of the communication pipe 101 is connected to the resonator 100 . An intake passage 80 inside the inlet pipe 6 communicates with the inside of the resonator 100 via a communicating pipe 101 .

Furthermore, as shown in FIGS. 5, 6 and 10, the inner wall 6c of the inlet pipe 6 has a notch 103 recessed from the inner wall 6c toward the upstream side and the downstream side of the intake air across the communication hole 102. is provided. The notch 103 is deepest in the vicinity of the communication hole 102 and gradually becomes shallower toward the upstream end 103a and the downstream end 103b. As shown in FIG. 10, the lower edge 103c of the notch 103 slopes downward from the upstream end 103a toward the downstream end 103b, so that the injected fuel injected into the inlet pipe 6 It is designed so that it can be prevented from accumulating in the communication hole 102 and the notch 103 .

As shown in FIG. 5, the intake passage 80 inside the inlet pipe 6 is partitioned by a partition portion 81 into a tumble passage 80A and a main passage 80B. In the inlet pipe 6, a plane passing through the center of the plate in the thickness direction of the partition 81 is defined as a partition central plane Pa, and an extended central plane Pb extending the partition central plane Pa along the shape of the inlet pipe 6 is defined. , a plane composed of the partition central plane Pa and the extension central plane Pb is defined as a central plane P such as a partition. The inlet pipe 6 is divided by the central plane P such as the partition, the portion on the tumble flow path 80A side is defined as the tumble flow path side portion 6a, and the portion on the main flow path 80B side is defined as the main flow path side portion 6b.

The communication hole 102 formed in the inlet pipe 6 is located in the inner wall surface _6a1 of the tumble flow path side portion 6a, as shown in FIGS. By providing the communication hole 102 in the tumble flow path side portion 6a in this manner, the intake air accumulated in the resonator 100 can be positively flowed to the tumble flow path 80A side when the intake valve 46 is being opened. You can try to strengthen the flow.

The communication hole 102 is formed between the downstream end 7a of the throttle body 7 and the upstream end 81a of the partition portion 81, as shown in FIG. By providing the communication hole 102 at a position relatively far from the combustion chamber 36, which is a heat-generating portion, even when airflow with a relatively high temperature flows into the intake passage 80, the communication pipe 101 connected to the resonator 100 is maintained. It is possible to prevent the heat from being transferred to the air intake, and to prevent the intake efficiency from being lowered.

Furthermore, as shown in FIG. 5, the communication hole 102 is provided downstream of the downstream end 8a of the insulator 8 that connects the throttle body 7 and the inlet pipe 6. As shown in FIG. Even if the inlet pipe 6 is connected to the throttle body 7 via the insulator 8, the communication hole 102 is not blocked by the insulator 8. - 特許庁

As shown in FIGS. 8 and 9, the inlet pipe 6 is fixed to the cylinder head 32 via the insulator 61 by bolts 37, which are fastening members. The communication hole 102 and the mounting portion 104 communicate with the communication hole 102 and project from the inlet pipe 6 so that the mounting portion 104 does not interfere with fastening the bolt 37 to the cylinder head 32. , are positioned so as not to overlap with the bolt 37.

Next, referring to FIGS. 11 and 12, the effect of enhancing the flow of the tumble flow by providing the resonator 100 downstream from the throttle valve 75 in communication with the intake passage 80 will be described with reference to FIGS. A description will be given in comparison with the case of an intake device. As shown in FIG. 11, in these intake devices, a tumble control valve 65 is attached to the upper passage of the intake passage, the upper side being the main passage 80B and the lower side being the tumble passage 80A. In FIG. 11, A and B indicate the positions of various locations representing changes in pressure within the intake system shown in FIG. Point A is located downstream of the throttle valve 75 and upstream of the upstream end 81a of the partition 81 separating the tumble flow path 80A and the main flow path 80B, and point B is located within the tumble flow path 80A. is doing.

FIG. 12 shows crank angles in one cycle when the throttle valve 75 is gradually opened for an intake system in which the resonator 100 is connected downstream of the throttle valve 75 and an intake system in which the resonator 100 is not connected downstream of the throttle valve 75. The pressure data at each location are shown with the crank angle on the horizontal axis and the pressure on the vertical axis. An intake passage area in the intake system from downstream of the throttle valve 75 to the intake valve 46 is defined as a throttle valve downstream intake area, and this volume is defined as a throttle valve downstream intake volume. These definitions also include areas and volumes within resonator 100 when resonator 100 is connected.

The pressure change in the intake passage and the flow of intake air when the resonator 100 is not connected downstream of the throttle valve 75 will be described. The case where the resonator 100 is not connected downstream of the throttle valve 75 means that the intake system does not have the resonator 100, and even if the intake system has the resonator 100, it is connected upstream of the throttle valve 75. is the case.
In an intake system in which the resonator 100 is not connected to the downstream side of the throttle valve 75, the intake volume downstream of the throttle valve is not large. , air is taken in from the atmosphere upstream of the throttle valve 75 through the opening of the throttle valve 75 . However, since the opening of the throttle valve 75 is small, the volume of air that increases as the piston 34 descends cannot be charged in time, and the pressure inside the intake port rapidly becomes negative (at crank angle 380 in FIG. 12). between about 540 degrees). When the pressure inside the intake port suddenly becomes negative in this way, as the piston 34 descends, the air in the intake area downstream of the throttle valve expands and is drawn in, weakening the flow and forming a tumble flow in the cylinder. weakens.

Next, the pressure change in the intake passage and the flow of intake air when the resonator 100 is connected downstream of the throttle valve 75 will be described. In the intake stroke from when the intake valve 46 opens to when it closes, compared to when the resonator 100 is not connected, the intake volume downstream of the throttle valve is larger by the volume inside the resonator 100, so the mass of the accumulated air is larger.
When the intake valve 46 opens, the volume of air that increases with the descent of the piston 34 is charged from the air accumulated in the intake area downstream of the throttle valve 75, and the throttle valve 75 opens. The amount of air taken from the atmosphere upstream of valve 75 is relatively small.
Therefore, even when the opening of the throttle valve 75 is small, such as when the throttle valve 75 is gradually opened, the change in the negative pressure in the intake port is relatively small (in FIG. ). Since the pressure inside the intake port does not suddenly drop to a negative pressure in this way, the expansion of the intake air in the intake area downstream of the throttle valve as the piston descends is relatively small, and the flow does not decrease, and the flow is formed in the cylinder. It is possible to increase the flow of the tumble flow.

Since the intake device for the internal combustion engine of the first embodiment is configured as described above, it has the following effects.

The intake device for an internal combustion engine of the first embodiment includes an intake passage 80 for introducing intake air into the combustion chamber 36, an inlet pipe 6 as an intake passage pipe whose interior is part of the intake passage 80, and the inlet pipe 6 In an intake structure of an internal combustion engine having a throttle body 7 for introducing intake air, a throttle valve 75 arranged inside the throttle body 7 for controlling the opening degree of an intake passage 80, and a resonator 100, the inlet pipe 6 is disposed downstream of the throttle body 7 and has a partition portion 81 that divides the intake passage 80 into a tumble passage 80A and a main passage 80B along the longitudinal direction, which is the inflow direction of the intake air. The inlet pipe 6 communicates with the inside of the resonator 100 via a communicating pipe 101, and the inlet pipe 6 has a communicating hole 102 located downstream of the throttle valve 75 and communicating between the intake passage 80 and the communicating pipe 101. ing.

Because of this configuration, even when the throttle valve 75 is throttled when the internal combustion engine 30 operates in a low load region, the intake air is discharged from the resonator 100 arranged downstream of the throttle valve 75. Since it flows into the passage 80, the flow in the intake passage 80 does not decrease, and the flow of the tumble flow can be strengthened to improve the combustion efficiency.

Furthermore, since the communication hole 102 is positioned on the tumble flow path side portion 6a of the inlet pipe 6, the air from the resonator 100 can flow into the tumble flow path 80A, which is narrower than the main flow path 80B. , the flow of the tumble flow is further enhanced, and the combustion efficiency is further improved.

Further, since the communication hole 102 is arranged between the downstream end 7a of the throttle body 7 and the upstream end 81a of the partition portion 81, the communication hole 102 communicates with the resonator 100 at a location distant from the combustion chamber 36 which is a heat generating portion. Even if the hole 102 is arranged and airflow with a relatively high temperature flows into the intake passage 80, the heat is not transmitted to the communicating pipe 101 communicating with the resonator 100, and the influence of the exhaust heat of the internal combustion engine 30 is reduced. It becomes difficult to be affected, and a reduction in intake efficiency can be prevented.

Furthermore, the inlet pipe 6 is provided at a position close to the upstream end 81a of the partition portion 81. A tumble control valve for changing the amount of intake air in the tumble flow path 80A is provided by a tumble valve body 67 as a rotatable plate-shaped valve body. 65, the amount of intake air flowing through the tumble flow path 80A can be controlled by the tumble control valve 65, and the flow of the tumble flow can be strengthened even in the low load region of the internal combustion engine 30, resulting in combustion efficiency. improves.

Further, the inlet pipe 6 has a mounting portion 104 to which one end 101a of the communicating pipe 101 is mounted, and the mounting portion 104 is integrated with the inlet pipe 6. This makes it possible to prevent an increase in the number of parts and reduce the labor required for processing.

Furthermore, since the communication hole 102 is located downstream of the downstream end 8a of the insulator 8 as a connection member connecting the throttle body 7 and the inlet pipe 6, the communication hole 102 overlaps with the mounting surface of the insulator 8. By providing the connecting hole 102 and the mounting portion 104 at such a position as not to interfere with the insulator 8, it is possible to improve the ease of assembly.

In addition, since the mounting portion 104 is positioned so as not to overlap the bolt 37 as a fixing member for fastening the inlet pipe 6 to the cylinder head 32 when viewed from the mounting direction of the bolt 37, the communication hole 102 and the mounting portion 104 do not overlap. It is possible to prevent interference with the bolt 37 and improve the ease of assembly.

Furthermore, a fuel injection valve 87 for injecting fuel toward the inside of the intake passage 80 is provided, and is provided on the inner wall 6c of the inlet pipe 6 at a position overlapping the communication hole 102, and is directed from the upstream side to the downstream side in the intake air flow direction. Since the notch portion 103 is provided, it is possible to prevent the injected fuel from accumulating in the communication hole 102 and the notch portion 103 .

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes are possible without departing from the gist of the present invention. , vehicles, internal combustion engines, etc., of course, include those implemented in various modes.
For convenience of explanation, the left-right arrangement of the illustrated embodiment has been described, but the present invention includes a different left-right arrangement as long as it is within the scope of the invention.

6... Inlet pipe 6a... Tumble flow path side part 6c... Inner wall 7... Throttle body 7a... Downstream end 8... Insulator 8a... Downstream end
30... internal combustion engine, 32... cylinder head, 36... combustion chamber, 37... bolt,
65 ... tumble control valve, 67 ... tumble valve element,
75 ... Throttle valve,
80... intake passage, 80A... tumble flow path, 80B... main flow path, 81... partition, 81a... upstream end, 87... fuel injection valve,
100... Resonator, 101... Communication tube, 101a... One end, 102... Communication hole, 103... Notch, 104... Mounting part.

Claims

An intake passage (80) that introduces intake air into the combustion chamber (36), an intake passage pipe (6) that is part of the intake passage (80), and intake air is introduced into the intake passage pipe (6). an internal combustion engine having a throttle body (7) for controlling the opening of the intake passage (80), a throttle valve (75) provided inside the throttle body (7) for controlling the opening of the intake passage (80), and a resonator (100) In the intake structure,
The intake passage pipe (6) is disposed on the downstream side of the throttle body (7), and extends along the longitudinal direction of the intake passage (80), which is the inflow direction of intake air. 80B) and a partition wall (81) dividing the
The intake passage pipe (6) is positioned downstream of the throttle valve (75) and has a communication hole (102) that opens into a communication pipe (101) that connects the resonator (100) and the intake passage (80). ), an intake device for an internal combustion engine.
The intake system for an internal combustion engine according to claim 1, wherein the communication hole (102) is located on the tumble flow path side portion (6a) of the intake passage pipe (6).
1. The communication hole (102) is located between the downstream end (7a) of the throttle body (7) and the upstream end (81a) of the partition wall (81). 3. The intake device for an internal combustion engine according to 2.
The intake passage pipe (6) is positioned close to the upstream end (81a) of the partition wall (81), and a rotatable plate-shaped valve body (67) controls the amount of intake air in the tumble flow passage (80A). 4. An intake system for an internal combustion engine according to any one of claims 1 to 3, characterized in that it has a valve (65) for changing the .
The intake passage pipe (6) has a mounting portion (104) to which one end (101a) of the communication pipe (101) is mounted,
An intake system for an internal combustion engine according to any one of claims 1 to 4, wherein said mounting portion (104) and said intake passage pipe (6) are integral parts.
The communication hole (102) is located downstream of a downstream end (8a) of a connecting member (8) connecting the throttle body (7) and the intake passage pipe (6). 6. An intake system for an internal combustion engine according to claim 3 or 5.
The communication hole (102) is positioned so as not to overlap a fixing member (37) for fastening the intake passage pipe (6) to the cylinder head (32) when viewed from the mounting direction of the fixing member (37). 7. An intake system for an internal combustion engine according to any one of claims 3 to 6, characterized by:
a fuel injection valve (87) for injecting fuel toward the inside of the intake passage (80);
The inner wall (6c) of the intake passage pipe (6) is provided with a notch (103) extending from the upstream side to the downstream side in the flow direction of the intake air,
An intake system for an internal combustion engine according to any one of claims 1 to 7, wherein the communication hole (102) is provided at a position overlapping with the notch (103).