JPH0783133A - Spark ignition type multiple cylinder engine - Google Patents

Abstract

PURPOSE:To distribute uniformly an air-fuel mixture formed in a mixing passage to each cylinder on throttle valve both sides by forming the throttle valve which is in opening condition linear-symmetrically with the passage center axial line of the mixing passage, viewing in direction which is in parallel with the cylinder center axial line. CONSTITUTION:The inlet 5 of an air-fuel mixture distributing passage 4 is connected to the outlet 3 of a mixing passage 2 in an air mixer 1. A valve shaft 8 is rotated by means of rocking of a governor lever 15 through an interlocking rod 12 and an interlocking arm 10 so as to open/close a throttle valve 9. In this case, the governor lever 15 is arranged in a direction which is in parallel with a cylinder arranging axial line 13 for connecting together those cylinder center axial line 6, 6, viewing in direction which is in parallel with each cylinder axial line 6, 6. The interlocking rod 12 is arranged in direction which is in parallel with the cylinder center axial line 6, viewing in direction which is in parallel with the passage center axial line 7 of the mixing passage 2. And the valve shaft 8 is arranged in direction which is in parallel with the cylinder arranging axial line 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spark ignition type multi-cylinder engine, and more particularly to a spark ignition type multi-cylinder engine capable of equalizing the distribution amount of air-fuel mixture to each cylinder.

[0002]

2. Description of the Related Art As a prior art of a spark ignition type multi-cylinder engine, there is one shown in FIG. Like the present invention, it has the following basic structure. That is, as shown in FIG. 5A, the mixing passage 102 of the air-fuel mixer 101.
The passage inlet 1 of the mixture distribution passage 104 to the passage outlet 103 of the
05 are connected to each other and viewed in a direction parallel to the cylinder center axis 106, the mixing passage 102 is directed in a direction orthogonal to the cylinder arrangement axis 113 connecting the cylinder center axes 106 and 106, and the mixture distribution passage 104 is It is formed in a shape branching from the passage inlet 105 toward each cylinder 107.

A valve shaft 108 is rotatably provided in the mixing passage 102 of the air-fuel mixer 101.
8, the throttle valve 109 is fixed, and the valve shaft 10
The interlocking arm 110 is fixed to the end portion of 8, and the interlocking arm 110 is attached via the interlocking rod 112 to the governor lever 115.
In order to perform opening / closing interlocking of the throttle valve 109 with the valve shaft 108 as the center of rotation through the push-pull operation of the interlocking rod 112 and the oscillating operation of the interlocking arm 110 in order by the pivoting operation of the governor lever 115. Is configured.

With such a basic structure, according to the opening degree of the throttle valve 109 which is interlocked with the governor lever 115, the passage outlet 103 of the mixing passage 102 is formed.
The air-fuel mixture is introduced into the passage inlet 105 of the air-fuel mixture distribution passage 104, and is distributed and supplied to each cylinder 107 via the air-fuel mixture distribution passage 104.

By the way, in this prior art, the governor lever 115 is oriented parallel to the cylinder center axis 106, the interlocking rod 112 is oriented parallel to the cylinder arrangement axis 113, and the valve shaft 108 of the throttle valve 109 is aligned with the cylinder center axis. It is oriented parallel to 106.

[0006]

In the above-mentioned prior art, since the throttle valve 109 is opened / closed with the valve shaft 108 in the direction parallel to the cylinder center axis 106 as the center of rotation, as shown in FIG. When viewed in a direction parallel to the central axis 106, the throttle valve 109 in the open state tilts with respect to the central axis 117 of the mixing passage 102.
Therefore, most of the air-fuel mixture formed in the mixing passage 102 hits the throttle valve 109, is guided along the inclination thereof, and escapes from one side of the throttle valve 109 to the passage inlet 105 of the air-fuel mixture distribution passage 104. .

Then, a small amount of air-fuel mixture that does not hit the throttle valve 109 escapes from the other side of the throttle valve 109 to the passage inlet 105 of the air-fuel mixture distribution passage 104. In this way, since the amounts of the air-fuel mixture that escape from both sides of the throttle valve 109 to the passage inlet 105 of the air-fuel mixture distribution passage 104 are different, the mixing to the cylinders 107, 107 located on both sides of the throttle valve 109 is different. The distribution of air becomes uneven, which is a factor that hinders smooth engine operation.

An object of the present invention is to provide a spark ignition type multi-cylinder engine which can achieve uniform distribution of air-fuel mixture to each cylinder.

[0009]

The present invention has the following basic structure as illustrated in FIG. 1 (A). That is, the passage outlet 3 of the mixing passage 2 of the air-fuel mixer 1
Is connected to the passage inlet 5 of the mixture distribution passage 4, and when viewed in a direction parallel to the cylinder center axis 6, the mixing passage 2 is oriented in a direction orthogonal to the cylinder array axis 13 connecting the cylinder center axes 6 and 6. At the same time, the air-fuel mixture distribution passage 4 is formed in a shape branched from the passage inlet 5 toward each cylinder 7.

As shown in FIGS. 1A and 1B, a valve shaft 8 is rotatably provided in the mixing passage 2 of the air-fuel mixer 1, and a throttle valve 9 is fixed to the valve shaft 8. At the same time, the interlocking arm 10 is fixed to the end of the valve shaft 8, and the interlocking arm 10 is interlockingly connected to the governor lever 15 via the interlocking rod 12, and the swinging operation of the governor lever 15 pushes and pulls the interlocking rod 12. The throttle valve 9 having the valve shaft 8 as the rotation center is interlocked with the opening and closing of the throttle valve 9 by rotating the interlocking arm 10 in order.

The present invention has the following features in the spark ignition type multi-cylinder ethidine having the above basic structure. That is, as shown in FIG. 1 (A), when viewed in a direction parallel to the cylinder center axis 6, the governor lever 15 is oriented parallel to the cylinder arrangement axis 13, and mixing is performed as illustrated in FIG. 1 (B). When viewed in a direction parallel to the passage center axis 7 of the passage 2, the interlocking rod 12 is oriented parallel to the cylinder center axis 6 and the valve shaft 8 of the throttle valve 9 is oriented parallel to the cylinder arrangement axis 13.

[0012]

As illustrated in FIG. 1, the throttle valve 9 has a valve shaft 8 oriented parallel to the cylinder array axis 13.
Since the opening / closing operation is performed with the center of rotation as the rotation center, as shown in FIG. 1 (A), when viewed in a direction parallel to the cylinder center axis 6,
The throttle valve 9 in the open state is line-symmetric with respect to the passage center axis line 17 of the mixing passage 2,
The air-fuel mixture formed inside of the air-fuel mixture uniformly flows out from both sides of the throttle valve 9 to the passage inlet 5 of the air-fuel mixture distribution passage 4, and the air-fuel mixture is distributed to the cylinders 7 located on both sides of the throttle valve 9. The amount becomes uniform. Therefore, the engine operating state can be smoothed.

[0013]

Embodiments of the present invention will be described with reference to the drawings.
1 to 4 are views for explaining a water-cooled two-cylinder gasoline engine of an overhead cam type according to an embodiment of the present invention. The structure of this engine is as follows. That is, as shown in FIG. 4, the cylinder head 19 is provided above the cylinder block 18.
Is assembled, the head cover 20 is assembled on the upper part thereof, and the gear case 21 is provided on the front side of the cylinder block 18.
And the belt case 22 are assembled. A cooling fan 23 is attached to the front side of the belt case 22, and a radiator 24 is arranged on the front side of the cooling fan 23. Also, FIG.
As shown in FIG. 1, a crank shaft 14 is installed inside a crank case 11 formed in the lower portion of the cylinder block 18. The crankshaft 14 has a crankpin angle of 0 ° and the cylinders 7 and 7 are ignited in sequence at 360 ° crank angle intervals.

The intake system of this engine is constructed as follows. That is, the air-fuel mixer 1 is attached to the central portion of the left lateral wall of the cylinder head 19 in the front-rear direction, and the air cleaner 25 is communicatively connected thereto. As shown in FIG. 1 (A), the cylinder head 19 includes a mixture distribution passage 4
Is installed in the air-fuel mixer 1, and the mixture outlet 2 of the mixing passage 2 of the air-fuel mixer 1 is provided with an air-fuel mixture distribution passage 4 through an insulator 26.
The passage entrance 5 is connected to and communicated with. When viewed in a direction parallel to the cylinder center axis 6, each cylinder center axis 6
The mixing passage 2 is oriented in a direction orthogonal to the cylinder array axis 13 that connects the six.

The mixture distribution passage 4 includes a pair of intake ports 2
The base ends of 7 and 27 are merged, and the common passage entrance 5
Is formed in a V-shape that branches from each of the cylinders 7 to 7. Since the air-fuel mixture distribution passage 4 is formed in the cylinder head 19 by utilizing the intake port 27,
No intake manifold required.

The speed governor of this engine is constructed as follows. That is, as shown in FIG. 1, a valve shaft 8 is rotatably provided in the mixing passage 2 of the air-fuel mixer 1, and a throttle valve 9 is fixed to the valve shaft 8.
An interlocking arm 10 is fixed to an end of the valve shaft 8, and a tip end of an interlocking rod 12 is pivotally supported on a swinging end 11 of the interlocking arm 10. The swing end 16 of the governor lever 15 is pivotally supported at the base end of the interlocking rod 12, and the swinging motion of the governor lever 15 pushes and pulls the interlocking rod 12.
The throttle valve 9 with the valve shaft 8 as the rotation center is interlocked with the opening and closing of the throttle valve 9 through the swinging motion of the interlocking arm 10 in order.

The governor lever 15 also has a cabana shaft 28.
Is rotatably supported by the cylinder block 18 via the cab, and is linked to the speed control lever 30 via the cabana spring 29. The spring force 31 of the cabana spring 29 urges the fuel increase side. Further, as shown in FIG. 2, a pair of left and right balancer shafts 32 are arranged in parallel on the cylinder block 18, and balancer gears 33 externally fitted and fixed to respective tip ends of the balancer shafts 32 are meshed with crank gears 34, respectively.

A governor weight 35 is pivotally supported behind the balancer gear 33 on the left side when viewed from the front side of the engine, and a cabana sleeve 36 is axially slidably fitted on the balancer shaft 32 behind it. As shown in FIG. 3 (A), the output end portion 37 of the governor weight 35 is brought into contact with the governor sleeve 36 from the front side thereof, and the centrifugal force generated in the governor weight 35 is directed from the output end portion 37 to the rearward governor force. It outputs to the governor sleeve 36 as 38.
Then, as shown in FIG. 3 (B), a fork lever 39 is fixed to the governor shaft 28, and a tip portion 40 of the fork lever 39 is abutted against the governor sleeve 36 from behind, and the governor force 38 is used as a force in the fuel reducing direction. 15 (see FIG. 1).

In this speed governor, when the engine speed fluctuates based on the fluctuation of the engine load, the governor force 38 fluctuates up and down, and the governor force 38 and the spring force 31 of the governor spring 29 shown in FIG. 1 (B). The governor lever 15 swings so as to balance with, the opening of the throttle valve 9 is changed, and the supply amount of the air-fuel mixture to the cylinder 7 is adjusted to be increased or decreased.
Maintains a constant engine speed regardless of load fluctuations.

In this embodiment, in order to equalize the distribution amount of the air-fuel mixture to each cylinder 7, the following structure is adopted in the speed governor. That is, as shown in FIG. 1A, the governor lever (15) is oriented parallel to the cylinder arrangement axis 13 when viewed in a direction parallel to the cylinder center axis 6. Further, as shown in FIG. 1B, the interlocking rod 12 is oriented parallel to the cylinder central axis 6 when viewed in a direction parallel to the central axis 7 of the mixing passage 2. The valve shaft 8 of the throttle valve 9 is oriented parallel to the cylinder array axis 13. Incidentally, reference numeral 41 in the drawing
Is a choke valve.

With such a configuration, as illustrated in FIG. 1A, the throttle valve 9 is opened and closed with the valve shaft 8 along the arrangement direction of the cylinders 7 as the center of rotation.
When viewed in a direction parallel to the cylinder center axis 6, the opened throttle valve 9 is line-symmetric with respect to the center axis 7 of the mixing passage 2, and the mixture formed in the mixing passage 2 is throttle valve 9 Evenly flowing from both sides to the passage inlet 5 of the air-fuel mixture distribution passage 4, the amount of air-fuel mixture distributed to each cylinder 8 located on both sides of the throttle valve 9 is made uniform.
Therefore, the engine operating state can be smoothed.

Further, in this embodiment, as shown in FIG. 2, a cam 42 is attached to an intermediate portion in the front-rear direction of the left balancer shaft 32 to which the governor weight 35 and the like are attached, and the front and rear of the left side wall of the cylinder block 18 is attached. The fuel supply pump 43 attached to the middle portion of the direction is driven by the cam 42. Therefore, as shown in FIG.
The fuel supply pump 43 is arranged at a position directly below the air-fuel mixer 1 arranged in the center of the cylinder head 19 on the left-hand side in the front-rear direction, and the fuel supply tube 44 connecting the fuel supply pump 43 and the air-fuel mixer 1 is moved up and down. Piped in the direction. For this reason, the fuel supply tube 44 can be short, and slack can be eliminated, so that the occurrence of vapor lock in the fuel supply tube 44 can be suppressed. In addition, the fuel supply tube 44
A support tool such as a clamp that supports the cylinder block 18 on the cylinder block 18 is also unnecessary.

Further, as shown in FIGS. 2 and 3 (A),
The Oldham joint 45 is attached to the front end of the balancer shaft 32 on the left side.
The input shaft 47 of the lubricating oil pump 46 is interlocked and coupled to the left balancer shaft 32 by the Oldham coupling 45, the governor weight 35, the governor sleeve 36, and the cam 42 for driving the fuel supply pump 43 of the lubricating oil pump 46. Are integrated, the space in the cylinder block 18 is saved, and the engine is downsized.

Further, as shown in FIG. 4, a pair of spark plugs 48, 48 are arranged on the left side of the cylinder head 19.
Oil level gauge 4 on the left side wall of the cylinder block 18.
9 is disposed, and the oil element 50 is disposed on the left side of the gear case 21. Therefore, the spark plug 48,
Air cleaner 25, air-fuel mixer 1, fuel supply pump 4
3, the speed control lever 30, the cabana lever 15, the oil level gauge 49, and the oil element 50 are collected on the left side of the engine, so that maintenance of the engine can be smoothly performed.

The contents of the embodiments of the present invention are as described above, but the present invention is not limited to the above embodiments. Although the above embodiment has been described with respect to an overhead cam type water-cooled two-cylinder gasoline engine, the present invention can be applied to a spark ignition type multi-cylinder engine. Therefore, it can be applied to various types of engines such as an overhead valve engine, an air-cooled engine, a liquid-cooled engine, a multi-cylinder engine with three or more cylinders, a gas engine, and the like. Further, as the air-fuel mixer, a carburetor is used in a gasoline engine and a gas mixer is used in a gas engine.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an engine according to an embodiment of the present invention, FIG. 1 (A) is a cross-sectional plan view near a cylinder head, and FIG. 1 (B) is a partially longitudinal front view near an air-fuel mixer. is there.

FIG. 2 is a cross-sectional plan view of the engine according to the embodiment of the present invention.

3 is a diagram illustrating a governor device used in the engine of FIG. 2, FIG. 3 (A) is a vertical cross-sectional side view near the governor device, and FIG.
FIG. 3B is a sectional view taken along line BB of FIG.

FIG. 4 is a side view of the engine of FIG.

5 is a diagram illustrating an engine according to a conventional technique, and FIG.
(A) is a cross-sectional plan view near the cylinder head, FIG. 5 (B)
FIG. 4 is a partially longitudinal front view of the vicinity of an air-fuel mixer.

[Explanation of symbols]

1 ... Air-fuel mixer, 2 ... Mixing passage, 3 ... Passage outlet,
4 ... Mixture distribution passage, 5 ... Passage inlet, 6 ... Cylinder center axis line, 7 ... Cylinder, 8 ... Valve shaft, 9 ... Throttle valve, 1
0 ... interlocking arm, 12 ... interlocking rod, 13 ... cylinder array axis, 15 ... governor lever.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Inoue 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Co., Ltd.

Claims (1)

[Claims] 1. A passage inlet (5) of a mixture distribution passage (4) is communicatively connected to a passage outlet (3) of a mixing passage (2) of an air-fuel mixer (1) and a cylinder center axis (6). Looking in parallel directions,
Cylinder array axis that connects each cylinder center axis (6) and (6)
The mixing passage (2) is directed in a direction orthogonal to (13), and the mixture distribution passage (4) is formed into a shape branched from the passage inlet (5) toward each cylinder (7) / (7). , A valve shaft (8) is rotatably provided in the mixing passage (2) of the air-fuel mixer (1), the throttle valve (9) is fixed to the valve shaft (8), and the end of the valve shaft (8) is fixed. The interlocking arm (10) is fixed to the part, and the interlocking arm (10) is interlockingly connected to the governor lever (15) through the interlocking rod (12).
With the swinging motion of (15), the valve shaft is pushed through the pushing and pulling motion of the interlocking rod (12) and the swinging motion of the interlocking arm (10) in this order.
In a spark ignition type multi-cylinder engine, which is configured to interlock the opening and closing of the throttle valve (9) with (8) as the rotation center, the governor lever (15) is seen when viewed in a direction parallel to the cylinder center axis (6). Orient it parallel to the cylinder array axis (13),
When viewed in a direction parallel to the passage center axis (7) of the mixing passage (2), the interlocking rod (12) is oriented parallel to the cylinder center axis (6), and the valve shaft (8) of the throttle valve (9) is A spark ignition type multi-cylinder engine characterized in that it is oriented parallel to the cylinder array axis (13).