[0001] The present invention relates to a vehicle, and in particular to a fuel feed device
that feeds a fuel to an engine, and a vehicle provided with the same.
[0002] Conventionally, a fuel injection type engine provided with an injector is known.
Usually, an engine of this type comprises an intake passage directed toward a combustion
chamber of the engine from an air cleaner, and an injector (referred below to as a
downstream injector) provided on a downstream side of the intake passage. Since the
downstream injector is arranged in a position close to the combustion chamber, however,
a fuel jetted from the downstream injector flows, in some cases, into the engine while
being not adequately atomized.
[0003] On the other hand, a fuel feed device is also known, in which an injector is provided
on an upstream side of an intake passage (for example, see JP-A-10-196494 and JP-A-2004-100632).
With the fuel feed device disclosed in these documents, an upstreamside opening of
the intake passage is opened in an air cleaner, and the injector (referred below to
as an upstream injector) is provided in a position away from the opening in the air
cleaner.
[0004] With the fuel feed device disclosed in these documents, an improvement in engine
performance is achieved by making use of the upstream injector, as by using the upstream
injector to replenish a fuel injection quantity, which is short only with the downstream
injector.
[0005] By the way, when an upstream injector is to be arranged, it must be taken account
of that a fuel jetted from the upstream injector is scattered outside an intake passage
(this phenomenon is referred below to as "blowing-over") due to turbulence of an air
flow in, for example, an air cleaner. Hereupon, it is conceivable as a method of restricting
blowing-over to restrict a quantity of a fuel jetted from the upstream injector.
[0006] When a quantity of a fuel jetted from the upstream injector is restricted, however,
there is a fear that a quantity of a fuel fed to a combustion chamber becomes short.
Therefore, it is difficult to achieve a sufficient improvement in engine performance.
[0007] The invention has been thought of in view of the matter and has its object to restrict
blowing-over of a fuel from an upstream injector while achieving a sufficient improvement
in engine performance.
[0008] This objective is solved in an inventive manner by a vehicle comprising an introduction
port, through which air is introduced to an intake chamber, an intake passage, which
includes an opening opened into the intake chamber and through which an air in the
intake chamber is led from the opening to an engine, fuel feed device having an injector
that jets a fuel toward the opening from between the introduction port and the opening
in the intake chamber, and a tubular jet protection member arranged between the injector
and the opening in the intake chamber to protect a fuel jetted from the injector and
passing therethrough toward the opening.
[0009] Preferably, the tubular member includes a downstream end positioned toward the intake
passage, and wherein an outside diameter of the downstream end is smaller than an
inside diameter of the opening of the intake passage.
[0010] Further, preferably the injector includes a nozzle portion formed with a jet port,
through which a fuel is jetted. Therein, the tubular member might include an upstream
end positioned toward the injector, wherein an inside diameter of the upstream end
of the tubular member is larger than an outside diameter of the nozzle portion. Therein,
the upstream end of the tubular member further might be formed to be bell-mouth-shaped.
[0011] Still further, preferably the nozzle portion is surrounded by the tubular member.
[0012] Yet further, preferably the tubular member and the intake passage are separable from
or separated from each other.
[0013] According to another embodiment, the opening of the intake passage is formed to be
bell-mouth-shaped.
[0014] According to still another embodiment, the tubular member includes an upstream end
positioned toward the injector, and wherein both, the upstream end of the tubular
member and the opening of the intake passage, are formed to be bell-mouth-shaped.
[0015] In the following, the present invention is explained in greater detail with respect
to several embodiments thereof in conjunction with the accompanying drawings, wherein:
- Fig. 1
- is a side view showing a motorcycle,
- Fig. 2
- is a cross sectional view showing a fuel feed device,
- Fig. 3
- is a cross sectional view showing the fuel feed device,
- Fig. 4
- is a plan view showing an interior of the fuel feed device,
- Fig. 5
- is a conceptual view showing a part of a fuel feed device according to a modification,
- Fig. 6
- is a conceptual view showing a part of a fuel feed device according to a further modification.
- Fig. 7
- is a conceptual view showing a part of a fuel feed device according to a further modification,
and
- Fig. 8
- is a conceptual view showing a part of a fuel feed device according to a further modification.
[0016] An embodiment will be described in detail with reference to the drawings.
[0017] As shown in Fig. 1, a motorcycle 100 comprises an air intake port 1, through which
an air is taken in, an air cleaner 5, an engine body 13, and a muffler 17. The air
intake port 1 and the air cleaner 5 are connected to each other through an intake
duct 3. The air cleaner 5 and combustion chambers 13c (see Fig. 2, not shown in Fig.
1) of the engine body 13 are connected to each other through intake passages 9. The
combustion chambers 13c and the muffler 17 are connected to each other through an
exhaust passage 15. Upstream injectors 7 are arranged inside the air cleaner 5 and
downstream injectors 11 are arranged inside the intake passages 9. The engine 13 is
a parallel 4-cylinder engine and the four intake passages 9 are provided along in
a vehicle breadth direction (a front-back surface direction in Fig. 1).
[0018] As shown in Fig. 2, a fuel feed device according to the embodiment comprises the
air cleaner 5, the upstream injectors 7, cylinders 23, second funnels 25, the intake
passages 9, and the downstream injectors 11.
[0019] The air cleaner 5 comprises a lower bowl-shaped casing 4 opened upward, and an upper
bowl-shaped casing 2 opened downward. The upper casing 2 and the lower casing 4 are
joined together in a state, in which mutual peripheral edges are butted against each
other. Thereby, an intake chamber 12 is compartmented inside the upper casing 2 and
the lower casing 4. An element 8 is arranged inside the intake chamber 12 to remove
dust and impurities contained in the air.
[0020] An introduction port 10, through which an air is introduced, is formed on a front
side (the left side in Fig. 2) of the lower casing 4. Also, four through-holes 22
aligned in the vehicle breadth direction are formed on a rear portion of a bottom
surface of the lower casing 4.
[0021] As described above, the four intake passages 9 aligned in the vehicle breadth direction
are formed in the engine. The respective intake passages 9 comprise a first funnel
24 fitted into the through-hole 22, a throttle body 26 fitted into the first funnel
24, a joint member 36 connected to a downstream end of the throttle body 26, and an
intake port 13f connected to a downstream end of the joint member 36. The first funnel
24 is opened into the intake chamber 12 to form openings of the intake passages 9.
A throttle valve 28 is provided inside the throttle body 26.
[0022] The intake port 13f is communicated to the combustion chamber 13c. Arranged in the
intake port 13f is an intake valve 13b driven by an intake cam 13a. Also, an exhaust
passage 15 (not shown in Fig. 2, see Fig. 1) is communicated to the combustion chamber
13c. Provided in an exhaust port (not shown) of the exhaust passage 15 is an exhaust
valve 13e driven by an exhaust cam 13d.
[0023] A mount 26b, to which the downstream injector 11 is mounted, is formed on a portion
of the throttle body 26 downstream of the throttle valve 28. The downstream injector
11 is mounted to the mount 26b and a nozzle 11 a of the downstream injector 11 is
extended inside the intake passage 9. Accordingly, the downstream injector 11 jets
a fuel downstream of the throttle valve 28.
[0024] A separate chamber cover 14 is mounted to an inner surface of a rear portion of the
upper casing 2. A separate chamber 16 is compartmented between the separate chamber
cover 14 and the upper casing 2, and the upstream injectors 7 are arranged in the
separate chamber 16. However, nozzles 7a of the upstream injectors 7 extend through
the separate chamber cover 14 to extend to the intake chamber 12. The upstream injector
7 is arranged so as to jet a fuel inside the first funnel 24.
[0025] An obliquely upwardly projecting support base 18 is formed on the bottom surface
of the rear portion of the lower casing 4. The support base 18 mounts thereto support
rods 19 extending in parallel to a direction, in which the first funnels 24 are opened.
A support plate 20 extending in the vehicle breadth direction (a front-back surface
direction in Fig. 2) is fixed to upper ends of the support rods 19 with bolts 21.
As shown in Fig. 4, four second funnels 25 aligned in the vehicle breadth direction
are fixed to the support plate 20.
[0026] Like the first funnels 24, the second funnels 25 comprise a cylindrical-shaped body,
an upper end of which is formed to be bell-mouth-shaped. In the embodiment, the second
funnels 25 are substantially the same in inside diameter as the first funnels 24.
Also, the second funnels 25 are substantially the same in outside diameter as the
first funnels 24. However, the first funnels 24 and the second funnels 25 may be different
in inside or outside diameter from each other.
[0027] The second funnels 25 are arranged between the nozzles 7a of the upstream injectors
7 and upstream ends of the first funnels 24. Also, the second funnels 25 are arranged
on extensions of the first funnels 24. That is, the second funnels 25 are arranged
to be coaxial with the first funnels 24. The second funnels 25 are arranged in positions
away from the first funnels 24, and clearances are defined between the upstream ends
of the first funnels 24 and the downstream ends of the second funnels 25.
[0028] Cylinders 23 made of aluminum are inserted inside the second funnels 25. The cylinders
23 are also arranged between the nozzles 7a of the upstream injectors 7 and the upstream
ends of the first funnels 24. The cylinders 23 are arranged to be coaxial with the
first funnels 24 and the second funnels 25. The cylinders 23 have a length substantially
equal to a distance between the upstream ends of the first funnels 24 and the downstream
ends of the second funnels 25.
[0029] As described later, the cylinders 23 are freely moved in an axial direction. Specifically,
the cylinders 23 are moved between positions (see Fig. 2), in which lower ends thereof
are fitted into the first funnels 24, and positions (see Fig. 3), in which the lower
ends thereof are away from the first funnels 24.
[0030] The cylinders 23 have an outside diameter substantially equal to an inside diameter
of the second funnels 25. Therefore, no clearances are substantially formed between
the cylinders 23 and the second funnels 25. Accordingly, while the cylinders 23 are
freely moved axially, the cylinders 23 and the second funnels 25 are contiguous to
each other.
[0031] Also, the cylinders 23 have an outside diameter substantially equal to an inside
diameter of the first funnels 24. Therefore, when the cylinders 23 are fitted into
the first funnels 24, the cylinders 23 are made contiguous to the first funnels 24.
Irrespective of positions of the cylinders 23, the cylinders 23 are contiguous to
the second funnels 25. Accordingly, when the cylinders 23 are fitted into the first
funnels 24, the first funnels 24 and the second funnels 25 are made contiguous to
each other through the cylinders 23, so that intake paths become longer than the intake
passages 9.
[0032] In a state, in which the cylinders 23 are away from the first funnels 24, the upstream
ends of the first funnels 24 serve as opened ends of the intake paths. On the other
hand, in a state, in which the cylinders 23 are fitted into the second funnels 25,
the upstream ends of the second funnels 25 serve as opened ends of the intake paths.
Hereinbelow, a state (see Fig. 3), in which the cylinders 23 are away from the first
funnels 24, is referred to a short state, and a state (see Fig. 2), in which the cylinders
23 are fitted into the first funnels 24, is referred to a long state. In addition,
the cylinders 23 and the second funnels 25 in the short state correspond to tubular
members of the embodiment.
[0033] As described above, the cylinders 23 are positioned between the nozzles 7a of the
upstream injectors 7 and the first funnels 24. The nozzles 7a are arranged obliquely
upward from the upstream ends of the cylinders 23. More specifically, the nozzles
7a are arranged in positions distant a predetermined distance from the upstream ends
of the cylinders 23 in an axial direction of the cylinders 23. Also, the nozzles 7a
are arranged centrally in openings of the cylinders 23 as viewed in the axial direction
of the cylinders 23. That is, the nozzles 7a jet a fuel toward centers of the cylinders
23 from positions away from the upstream ends of the cylinders 23. In addition, a
fuel jetted from the nozzles 7a pass through the cylinders 23 to flow into the intake
passages 9. In this manner, the cylinders 23 are arranged in positions, in which a
fuel jetted from the upstream injectors 7 is led to the intake passages 9.
[0034] The cylinders 23 project obliquely upward from the second funnels 25 in the short
state (see Fig. 3). In the embodiment, the nozzles 7a are positioned obliquely upward
from upper ends of the cylinders 23 in the short state. Accordingly, the nozzles 7a
jet a fuel toward positions distant obliquely upwardly from the cylinders 23 at all
times.
[0035] Also, the nozzles 7a jet a fuel in a manner to have the same spreading upstream of
the upstream ends of the cylinders 23. Such configuration of jetting can be readily
realized by appropriately setting a diameter of the nozzles 7a, a distance of the
nozzles 7a from the cylinders 23, a jetting direction of the nozzles 7a, a jet velocity,
etc.
[0036] Subsequently, an explanation will be given to a moving mechanism 40 that moves the
cylinders 23. As shown in Fig. 4, a connection rod 27 extending in the vehicle breadth
direction is mounted to the cylinders 23. The connection rod 27 extends through the
respective cylinders 23 to connect the four cylinders 23 together. As shown in Fig.
2, slots 29 extending in the axial direction of the second funnels 25 are formed on
both sides of the second funnels 25 in the vehicle breadth direction. The connection
rod 27 is arranged in the slots 29.
[0037] A longitudinally central portion of the connection rod 27 is supported rotatably
on one end of a lever 30 extending in a longitudinal direction (a left and right direction
in Fig. 2). A cam bearing roller 31 projecting laterally is provided on the other
end of the lever 30. A cam 32 and a motor 33 for rotation of the cam 32 are arranged
on the other end side of the lever 30. The cam 32 is arranged above the cam bearing
roller 31 to contact with the cam bearing roller 31. A middle portion of the lever
30 is supported rotatably on a support shaft 34, and a spring 35 is mounted on a rear
side of the support shaft 34 to pull the other end of the lever 30 upward.
[0038] When the other end of the lever 30 is lifted by the spring 35, the cylinders 23 are
pushed obliquely downward. As a result, the cylinders 23 are fitted into the first
funnels 24 to put the intake paths in the long state. On the other hand, when the
cam 32 rotates to push down the other end of the lever 30, the cylinders 23 are pushed
obliquely upward. As a result, the cylinders 23 get out from the first funnels 24
and the intake paths are put in the short state.
[0039] In addition, the reference numeral 60 denotes a controller that controls injection
of the upstream injectors 7 and the downstream injectors 11 and the moving mechanism
40.
[0040] Subsequently, an explanation will be given to a fuel feeding operation of the fuel
feed device.
[0041] An air introduced from the introduction port 10 of the air cleaner 5 is purified
by the element 8 and then sucked into the intake passages 9. At this time, when the
intake paths are put in the long state, an air is sucked from the second funnels 25.
On the other hand, when the intake paths are put in the short state, an air is sucked
from the first funnels 24. More specifically, a part of the air passes through the
second funnels 25 and the cylinders 23 and is then sucked into the first funnels 24,
and the remainder of the air is sucked into the first funnels 24 through clearances
between the first funnels 24 and the second funnels 25.
[0042] In the intake stroke of the engine body 13, the intake valves 13b are opened by the
intake cams 13a and a fuel is jetted from one of the upstream injectors 7 and the
downstream injectors 11.
[0043] A fuel jetted from the upstream injectors 7 passes inside the second funnels 25 and
the cylinders 23 to flow into the intake passages 9 from the first funnels 24. A fuel
inflowing from the first funnels 24 is fed to the combustion chambers 13c via the
throttle bodies 26 and the intake ports 13f.
[0044] According to the embodiment, when the intake paths are put in the short state, blowing-over
of a fuel from the upstream injectors 7 is restricted by the cylinders 23. That is,
even when a fuel from the upstream injectors 7 is scattered outside due to turbulence
of an air flow in the air cleaner 5, the fuel adheres to inner peripheral surfaces
of the cylinders 23 and is then sucked into the intake passages 9. Accordingly, there
is less fear that a fuel scattered blows over. Therefore, expediting atomization of
a fuel and prevention of blowing-over of a fuel are made compatible with each other,
so that it is possible to restrict blowing-over of a fuel while achieving a sufficient
improvement in engine performance.
[0045] Also, the upstream ends of the cylinders 23 have an inside diameter larger than an
outside diameter of the nozzles 7a. Therefore, when a fuel is jetted from the nozzles
7a, an air inflows from between edges of the upstream ends of the cylinders 23 and
outer peripheries of the nozzles 7a. Thereby, spreading of a fuel from the nozzles
7a is suppressed by the inflowing air. Accordingly, blowing-over is restricted. Also,
the inflowing air expedites atomization of a fuel.
[0046] Also, according to the embodiment, downstream ends of the cylinders 23 have an outside
diameter smaller than an inside diameter of the upstream ends of the first funnels
24. Therefore, there is no fear that a fuel flowing downstream of the cylinders 23
scatters outside the first funnels 24, so that blowing-over is further restricted.
[0047] In addition, since the upstream ends of the second funnels 25 are formed to be bell-mouth-shaped,
the inflowing air can be led smoothly and inflow of an air can be expedited by using
the second funnels 25 as tubular members for prevention of blowing-over, in place
of the cylinders 23 (see Fig. 5). Also, since the second funnels 25 makes it possible
to suck an air from a relatively large region, scattering of a fuel as jetted can
be suppressed by the inflowing air and blowing-over can be further effectively restricted.
With the example shown in Fig. 5, upstream sides of both the tubular members (in this
case, the second funnels 25) and the intake passages 9 are formed to be bell-mouth-shaped,
so that the effect of smoothly leading an air is great.
[0048] Also, according to the embodiment, the cylinders 23 and the first funnels 24 separate
completely from each other when the intake paths are put in the short state. Accordingly,
as compared with the case where the cylinders 23 and the first funnels 24 are partially
connected to each other, large opened areas of the intake passages 9 can be ensured
to maintain the intake performance favorable.
[0049] In addition, according to the embodiment, the cylinders 23 are provided to axially
move relative to the second funnels 25, and tubular members for prevention of blowing-over
are formed by the cylinders 23. However, the tubular members are not limited to movable
ones but may comprise of course ones that are stationary in fixed positions.
[0050] Also, the tubular members are not limited to round pipes but may comprise rectangular
pipes. In addition, in the case where the tubular members, etc. are other than round
pipes, a diameter means a hydraulic diameter. Further, the tubular members are not
limited to pipes having a constant inside diameter but may comprise pipes having a
inside diameter varying in an axial direction. For example, the tubular members may
be cone-shaped or pyramid-shaped. Also, the tubular members may be a little curved
as far as a fuel can be smoothly led to the intake passages 9.
[0051] According to the embodiment, the nozzles 7a of the upstream injectors 7 are separated
obliquely upward from the upstream ends of the cylinders 23. As shown in Fig. 6, however,
the nozzles 7a may get inside the tubular members 50. Thereby, blowing-over of a fuel
is further restricted.
[0052] According to the embodiment, the cylinders 23 and the first funnels 24 separate from
each other when the intake paths are put in the short state. As shown in, for example,
Fig. 7, however, the tubular members 50 and the intake passages 9 may be partially
connected to each other. That is, the tubular members 50 and the intake passages 9
may be made integral with each other. In addition, a configuration, in which the tubular
members 50 and the intake passages 9 are connected to each other, is not especially
limitative.
[0053] Also, as shown in Fig. 8, the tubular members 50 and the intake passages 9 may be
made integral with each other and openings 51 thereof may be formed to be bell-mouth-shaped.
Thereby, inflow of an air from the openings 51 can be made smooth.
[0054] In addition, the engine according to the embodiment comprise the upstream injectors
7 and the downstream injectors 11, and is a so-called twin injector type engine. However,
the engine according to the invention may be one provided with only the upstream injectors
7.
[0055] According to the embodiment, the upstream injectors 7 are arranged inside the air
cleaner 5. However, the upstream injectors 7 may be arranged outside the air cleaner
5 as far as a fuel is jetted inside the intake chamber 12.
[0056] The vehicle according to the embodiment comprises a motorcycle 100. However, the
vehicle according to the embodiment is not limited to a motorcycle. In addition, a
motorcycle referred herein includes a scooter, etc. in addition to a so-called motorbike.
[0057] As described above, the teaching of the embodiment is useful for a fuel feed device
and a vehicle provided with the same.
[0058] The description above discloses (amongst others) an embodiment of a fuel feed device
which comprises an intake chamber having an introduction port, through which an air
is introduced, an intake passage, which includes an opening opened into the intake
chamber and through which an air in the intake chamber is led from the opening to
an engine, an injector that jets a fuel toward the opening from between the introduction
port and the opening in the intake chamber, and a tubular member arranged between
the injector and the opening in the intake chamber to permit a fuel jetted from the
injector to pass therethrough toward the opening.
[0059] With the fuel feed device, a jet flow from the injector is surrounded by the tubular
member. Therefore, blowing-over of a fuel is restricted by the tubular member. Accordingly,
even when the injector is not made close to the opening of the intake chamber, it
is possible to restrict blowing-over. Therefore, with the fuel feed device, it is
possible to expedite atomization of a fuel and prevent blowing-over of a fuel in a
compatible manner.
[0060] According to this embodiment, it is possible to restrict blowing-over of a fuel while
achieving a sufficient improvement in engine performance.
[0061] According to a preferred embodiment, the tubular member includes a downstream end
positioned toward the intake passage, and an outside diameter of the downstream end
is smaller than an inside diameter of the opening of the intake passage.
[0062] According to a further preferred embodiment, the tubular member includes an upstream
end positioned toward the injector, the injector includes a nozzle portion formed
with a jet port, through which a fuel is jetted, and an inside diameter of the upstream
end of the tubular member is larger than an outside diameter of the nozzle portion.
[0063] Therein, the upstream end of the tubular member may be formed to be bell-mouth-shaped.
[0064] According to another preferred embodiment, the injector includes a nozzle portion
formed with a jet port, through which a fuel is jetted, and the nozzle portion is
surrounded by the tubular member.
[0065] According to still another preferred embodiment, the tubular member and the intake
passage are separated from each other.
[0066] According to yet another preferred embodiment, the opening of the intake passage
is formed to be bell-mouth-shaped.
[0067] Further, preferably the tubular member includes an upstream end positioned toward
the injector, and both the upstream end of the tubular member and the opening of the
intake passage are formed to be bell-mouth-shaped.
[0068] The description also refers to a vehicle comprising the fuel feed device according
to any one of the above embodiments.
[0069] In order to restrict blowing-over of a fuel while achieving a sufficient improvement
in engine performance in a fuel feed device provided with an injector, which jets
a fuel from an upstream side of an intake passage, the description discloses, as a
particularly preferred embodiment, a fuel feed device which comprises an air cleaner
5 formed inside with an intake chamber 12, an intake passage 9 including a first funnel
24 opened to the intake chamber 12, an upstream injector 7 that jets a fuel to a position
away from the first funnel 24, and a cylinder 23 arranged between the upstream injector
7 and the first funnel 24. The cylinder 23 is arranged in a position, in which a fuel
jetted from the upstream injector 7 is led to the intake passage 9.
[0070] The description above still further discloses an embodiment of an engine comprising
an engine body having a combustion chamber, an intake chamber having an introduction
port, through which an air is introduced, an intake passage, which includes an opening
opened into the intake chamber and through which the air in the intake chamber is
led from the opening to the combustion chamber, an injector that jets a fuel between
the introduction port and the opening, an exhaust passage, through which combustion
gases are led from the combustion chamber, and a control mechanism that makes use
of pressure waves generated in at least one of the intake passage and the exhaust
passage to vary torque characteristics so as to eliminate valleys in a torque characteristic
curve indicating a change in torque relative to a change in engine speed.
[0071] Preferably, the control mechanism varies the torque characteristics at a larger rate
than that, at which the torque characteristics varies due to fuel injection of the
injector.
[0072] The description yet further discloses an embodiment of an engine comprising an engine
body having a combustion chamber, an intake chamber having an introduction port, through
which an air is introduced, an intake passage, which includes an opening opened into
the intake chamber and through which the air in the intake chamber is led from the
opening to the combustion chamber, an injector that jets a fuel between the introduction
port and the opening, and a control mechanism that exercises control to synchronize
phase of pressure waves generated in the intake passage and timing of intake of the
combustion chamber with each other.
[0073] The description above still further provides an embodiment of the engine comprising
an engine body having a combustion chamber, an intake chamber having an introduction
port, through which an air is introduced, an intake passage, which includes an opening
opened into the intake chamber and through which the air in the intake chamber is
led from the opening to the combustion chamber, an injector that jets a fuel between
the introduction port and the opening, and a control mechanism that exercises control
to synchronize phase of pressure waves generated in the exhaust passage and timing
of exhaust of the combustion chamber with each other.
[0074] With the engine according to the above embodiment, an air flowing through the intake
passage is evaporated and cooled by a fuel, which is jetted from the injector, over
a relatively long period of time. Therefore, the air density is increased and the
volumetric efficiency of the engine is enhanced. In addition, with the engine, the
control mechanism adjusts the torque characteristics so as to eliminate valleys in
a torque characteristic curve. Therefore, although injection of a fuel from the injector
varies the period of pulsation waves in the intake passage, a decrease in torque is
restricted. Accordingly, it is possible to demonstrate the effect of an increase in
volumetric efficiency, produced by the injector, to the maximum, and so a great improvement
in engine performance is achieved.
[0075] Accordingly, since the effect of an increase in volumetric efficiency, produced by
the injector, can be demonstrated to the maximum, it is possible to greatly improve
the engine performance.