JP3154878U - engine - Google Patents

Abstract

To provide an engine capable of ensuring a necessary intake pipe length without causing an intake resistance in order to make fuel atomization in a high-speed rotation / high-load operation range good. An engine includes an intake device. The intake device 9 includes an air cleaner (intake box) 35 having a required capacity that is common to all cylinders, four sets of intake passages 44 provided for each cylinder that connects the air cleaner 35 and each combustion chamber, An intake control valve 31 disposed in each intake passage 44, a first fuel injection valve 39 for supplying fuel to the downstream side of the intake control valve 31, and a second fuel injection valve 40 for supplying fuel to the upstream side; It has. The first fuel injection valve 39 injects and supplies fuel in a low, medium speed rotation / low, medium load operation region, and the second fuel injection valve 40 fuels in a medium, high speed rotation / medium, high load operation region. Is controlled to be supplied by injection. [Selection] Figure 4

Description

  The present invention relates to an engine in which fuel injection valves are arranged on a downstream side and an upstream side of a throttle valve in an intake passage.

  In this type of engine, a low-rotation / low-load fuel injection valve may be disposed on the downstream side of the throttle valve in the intake passage, and a high-speed rotation / high-load fuel injection valve may be disposed on the upstream side.

  In this case, in order to improve the atomization of the fuel in the high speed rotation / high load operation region, the intake pipe length from the fuel injection valve for the high speed rotation / high load to the combustion chamber is made as long as possible. . For example, Patent Document 1 proposes a structure in which a bracket is provided so as to straddle an intake opening of an intake passage located in an air cleaner, and a fuel injection valve for high-speed rotation and high load is attached to the bracket.

Patent No. 3690824

  By the way, in the structure in which the bracket is provided so as to straddle the conventional intake opening, there is a concern that the bracket and the fuel injection valve may become resistance to air flow, and there is a concern that the output in the high speed rotation / high load region may be reduced. .

  The present invention has been made in view of the above-described conventional situation, and an object thereof is to provide an engine that can secure a necessary intake pipe length without causing intake resistance.

  The present invention provides an intake box having a predetermined capacity, an intake passage connecting the intake box and a combustion chamber of the engine, an intake control valve interposed in the middle of the intake passage, and intake air in the intake passage An engine comprising: a first fuel injection valve that supplies fuel downstream from a control valve; and a second fuel injection valve that supplies fuel upstream from the intake control valve of the intake passage, wherein the intake passage is The second fuel injection valve has a cylindrical portion protruding into the intake box, and the second fuel injection valve injects and supplies fuel to the inside through a wall portion of the protruding portion in the intake box of the cylindrical portion.

  According to the present invention, since the second fuel injection valve is arranged so as to supply fuel into the protrusion in the intake box, the second fuel injection valve to the combustion chamber is equivalent to the protrusion in the intake box of the cylinder portion. The length of the intake pipe can be lengthened, fuel atomization can be promoted at high speed and high load, and fuel and air can be mixed uniformly.

  Further, since the second fuel injection valve is arranged so as to inject and supply the fuel through the wall portion of the protruding portion in the intake box of the cylindrical portion, there is nothing that becomes an intake resistance in the intake opening of the cylindrical portion. The amount of intake air can be increased and the engine output can be improved.

1 is a left side view of a snowmobile equipped with an engine according to Embodiment 1 of the present invention. It is a left view of the engine. It is a top view of the intake device portion of the engine. It is a cross-sectional side view which shows the arrangement state of the 1st, 2nd fuel injection valve of the said engine.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 4 are views for explaining an engine according to a first embodiment of the present invention.

  In the figure, reference numeral 1 denotes a snowmobile. The snowmobile 1 includes a vehicle body frame 2, an engine 3 mounted on the front portion of the vehicle body frame 2, a straddle-type seat 4 disposed above the rear portion of the vehicle body frame 2, A fuel tank 8 disposed in front, a bar-type steering handle 5 disposed in front of the seat 4 so as to be steerable left and right, and disposed on the left and right front ends of the body frame 2 The skis 6 and 6 and the driving track 7 mounted on the rear portion of the vehicle body frame 2 are provided.

  The snowmobile 1 includes a front cover 10 that covers a front portion of the vehicle body frame 2 including the engine 4, a side cover 11 that covers the lower periphery of the seat 4, and front and rear portions that are disposed on the left and right sides below the seat 4. Foot boards 12, 12 extending in the direction are provided.

  A windshield 45 is disposed in front of the steering handle 5, and a headlight 13 is disposed on the windshield 45.

  The drive track 7 includes a wide track belt 15, a drive wheel 16 that is rotationally driven by the engine 3, a slide rail 17 that presses the track belt 15 against a snow surface, and the track belt 15 that is substantially a parallelogram. The lower guide wheel 18 and the upper guide wheel 19 are supported so as to form the following.

  The left and right skis 6 are supported by the vehicle body frame 2 via a front suspension device 20 so as to be swingable up and down, and can be steered left and right by the steering handle 5. The slide rail 17 is supported by the vehicle body frame 2 via the rear suspension device 21 so as to be swingable up and down.

  The snowmobile 1 is configured to travel freely on the snow by rotating the track belt 15 by rotationally driving the drive shaft 16a of the drive wheel 16 by the engine 3.

  The engine 3 is a four-cycle parallel four-cylinder engine, and is mounted with the cylinder axis A inclined rearward in the vehicle front-rear direction and the crankshaft 25 directed in the vehicle width direction.

  The engine 3 includes a crankcase 25 in which a crankshaft 25 and a transmission (not shown) disposed on the rear side of the crankshaft 25 are accommodated, a cylinder block 27 coupled to the crankcase 26, and the cylinder The cylinder head 28 is coupled to the block 27, and the head cover 29 is attached to the cylinder head 28.

  On the lower joint surface of the cylinder head 28, four combustion recesses 28a constituting a combustion chamber for each cylinder are formed. An intake port 28b communicating with each combustion recess 28a is opened on the front side wall of the cylinder head 28, and an exhaust port 28c communicating with each combustion recess 28a is opened on the rear side wall. An exhaust pipe (not shown) is connected to each exhaust port 28c, and a muffler 30 (see FIG. 1) common to each cylinder is connected to the downstream end of the exhaust pipe.

  The engine 3 includes an intake device 9. The intake device 9 includes an air cleaner (intake box) 35 having a required capacity and common to all cylinders, and four sets of intake passages 44 provided for each cylinder connecting the air cleaner 35 and the combustion chambers. An intake control valve 31 disposed in each intake passage 44, a first fuel injection valve 39 for supplying fuel to the downstream side of the intake control valve 31, and a second fuel injection valve 40 for supplying fuel to the upstream side. And.

  The first fuel injection valve 39 injects and supplies fuel in a low, medium speed rotation / low, medium load operation region, and the second fuel injection valve 40 fuels in a medium, high speed rotation / medium, high load operation region. Is controlled to be supplied by injection.

  The air cleaner 35 is disposed in front of the engine 3 and in the vicinity of the lower portion of the front cover 10, and connects the first box half 35a located on the lower side and the second box half 35b located on the upper side to each other. The mating surface 35c is detachably fitted and connected. The air cleaner 35 filters air introduced from an air suction port (not shown) through an element and supplies the air to the engine 3.

  The intake passage 44 includes the intake port 28b, a throttle body 32 connected to an external opening of the intake port 28b, and a funnel (tubular portion) 33 connected to the throttle body 32.

  The throttle body 32 is composed of a straight metal cylinder. On the other hand, the funnel 33 is made of rubber having a substantially cylindrical shape. The funnel 33 is a substantially straight straight tube portion 33a fastened and fixed to the throttle body 32 by a band 36, and the straight tube portion 33a is followed by the above-described straight tube portion 33a. The first box half body 35a has a curved cylinder portion (projecting portion in the intake box) 33b penetrating through the rear wall 35a 'and projecting inward from the rear wall 35a' toward the upstream side of the intake air flow. The intake opening 33e of the curved cylinder portion 33b is expanded in a trumpet shape. The straight cylinder portion 33a and the axis B of the throttle body 32 are substantially linear.

  A flange portion 33c having an engagement groove 33d is formed at the boundary portion between the curved tube portion 33b and the straight tube portion 33a, and the opening edge portion 35d of the first box half body 35a is hermetically sealed in the engagement groove 33d. Is engaged.

  The intake control valve 31 is disposed substantially in the center of the throttle body 32 in the axial direction, and the first fuel injection valve 39 is disposed in the throttle body 32. Specifically, the first fuel injection valve 39 is mounted on a boss portion 32 a formed on the upper wall portion 32 b of the throttle body 32. The injection port 39a of the first fuel injection valve 39 is located on the downstream side of the intake control valve 31, and is arranged to inject and supply fuel through the intake port 28b toward the back surface of the intake valve. .

  The intake control valve 31 is a butterfly type, and includes a valve plate 31a and a valve shaft 31b to which the valve plate 31a is fixed. The valve shaft 31b is disposed in parallel with the crankshaft 25, passes through the throttle body 32, and is rotatably supported by the throttle body 32. The valve shafts 31b of the cylinders are connected to each other via a connection mechanism (not shown).

  Here, when the intake control valve 31 is fully closed, the portion close to the second fuel injection valve 40 from the valve shaft 31b of the valve plate 31a, that is, the upper portion 31a 'is located downstream from the portion farther (lower portion). It is arranged to be inclined. Therefore, in the intake control valve 31, the upper portion 31a 'opens in the downstream direction (arrow C direction). Therefore, in the operation region where the valve opening is small, an intake air flow D is generated in a portion close to the injection port 39a.

  Each first fuel injection valve 39 is connected to one first fuel supply rail 41 common to each cylinder. The first fuel supply rails 41 are attached to the throttle bodies 32, and fuel supply pipes 41a are connected to the axial ends of the first fuel supply rails 41. A fuel pump (not shown) disposed in the fuel tank 8 is connected to the fuel supply pipe 41a via a fuel hose (not shown).

  Each of the second fuel injection valves 40 is supported by the second box half 35b of the air cleaner 35 and is disposed so as to inject and supply fuel into the middle portion of the curved cylindrical portion 33b. It has a mounting structure.

  One recess 35e extending in the vehicle width direction is in contact with the rear end of the upper wall 35b 'of the second box half 35b. And, on the bottom wall of the recess 35e, four support bosses 35f are formed so as to bulge downward, and the recesses 35e are formed on the side of the curvature center of the curved cylindrical portion 33b of each funnel 33 ( It is close to the upper wall portion 33f located on the outer side.

  An insertion boss portion 33g is integrally formed on the upper wall portion 33f of the curved cylindrical portion 33b, and the insertion boss portion 33g has an injection hole 33h penetrating therethrough.

  Each of the second fuel injection valves 40 is mounted on the support boss portion 35f from above the second box half body 35b, and the injection port 40a of the second fuel injection valve 40 extends from the insertion hole 3535g to the insertion boss portion 33g. It faces the inside of the curved cylindrical portion 33b through the injection hole 33h.

  Each of the second fuel injection valves 40 is arranged so as to be substantially coaxial with the axis B, and injects and supplies fuel along the axis B. The second fuel injection valve 40 and the first fuel injection valve 39 are arranged on the same side with respect to the axis B.

  One second fuel supply rail 42 common to each cylinder is connected to the second fuel injection valve 40, and the second fuel supply rail 42 is attached to the recess 35e. The central portion of the second fuel supply rail 42 and the central portion of the first fuel supply rail 41 are connected by a fuel supply hose 43.

  When viewed from the side of the vehicle, the second fuel injection valve 40 is immersed in the recess 35e, so that the second fuel injection valve 40 is disposed outside the air cleaner 35 and the position of the second fuel injection valve 40 is less than that of the air cleaner 35. It avoids becoming high.

  Here, the concave portion 35e is disposed on the side opposite to the element from the intake opening 33e. Therefore, the air flow filtered by the element flows into the intake opening 33e without the concave portion 35e becoming a resistance. That is, in this embodiment, the recess 35e is formed by using a dead space that hardly affects the air flow in the air cleaner 35, and the second fuel injection valve 40 is not sacrificed in the capacity of the air cleaner 35. From the above, fuel can be supplied into the curved cylindrical portion 33b.

  According to the present embodiment, the second fuel injection valve 40 is disposed so as to supply fuel into the middle portion of the curved cylindrical portion 33b that projects and extends into the air cleaner 35 of the funnel 33, so that the curved cylindrical portion 33b is provided with the air cleaner. The length of the intake pipe from the second fuel injection valve 40 to the combustion recess 28a can be increased by the amount protruding inward. Thereby, the atomization of the fuel in the high speed rotation / high load region can be promoted, the mixing of the fuel and the air can be made uniform, and the engine output can be improved. Further, the charging efficiency can be increased by the amount that the intake air temperature becomes lower due to the latent heat of vaporization by the promotion of atomization, and the engine output can also be improved from this point.

  In addition, since the length of the intake pipe is increased by extending the curved cylindrical portion 33b into the air cleaner 35, it is not necessary to increase the length of the intake passage from the air cleaner 35 to the engine 3, and thus it is not necessary to increase the height of the air cleaner 35. And the problem of interference with the front cover 10 can be avoided.

  Since the second fuel injection valve 40 is disposed in the middle of the curved cylindrical portion 33b, there is nothing in the intake opening 33e of the curved cylindrical portion 33b that serves as an intake resistance, and a sufficient intake amount in the high speed range is provided. Can be ensured, and engine output can be improved.

  In the present embodiment, since the second fuel injection valve 40 is disposed on the center side of the curved surface of the curved cylindrical portion 33b (outside of the bend), the second fuel injection valve 40 faces the substantially central portion of the throttle body 32. The fuel can be supplied so as to be coaxial with the axis B. Thereby, it is possible to suppress the fuel from adhering to the passage wall surface, and from this point, the mixing of fuel and air can be made uniform.

  Further, since the fuel is injected and supplied from the middle portion of the curved cylindrical portion 33b, the injected fuel can be prevented from escaping out of the intake passage, and can be reliably supplied to the combustion chamber. That is, when fuel is injected from the upstream side of the intake opening 33e as in the conventional device, a part of the fuel may escape to the outside of the intake passage due to the spread of the spray.

  In this embodiment, since the second fuel injection valve 40 is supported by the air cleaner 35, the support rigidity of the second fuel injection valve 40 can be ensured and the support structure can be simplified. If the fuel injection valve is supported by the funnel 33, the funnel needs to have a strong structure such as resin, and the degree of freedom of shape may be reduced due to restrictions on resin molding. In this embodiment, it is not necessary to increase the strength of the funnel 33, so that it can be made of rubber or the like, and the curved cylindrical portion 33b can be formed easily and at low cost.

  In this embodiment, since the funnel 33 is connected to the first box half 35a of the air cleaner 35 and the second fuel injection valve 40 is supported by the second box half 35b, the funnel 33, the second fuel injection valve 40, As a result, the assembly work can be facilitated and the maintenance of the second fuel injection valve 40 can be easily performed.

  In the present embodiment, the first fuel injection valve 39 and the second fuel injection valve 40 are arranged on the same side with respect to the axis B, so that the first fuel injection valve 39 and the second fuel injection valve 40 are supplied with fuel. The fuel supply path including the first fuel supply rail 41 and the second fuel supply rail 42 can be configured with a simple structure and compactly.

  In this embodiment, the intake control valve 31 is configured such that the portion close to the second fuel injection valve 40 side of the valve plate 31a, that is, the upper portion 31a 'opens in the downstream direction. The intake flow D can be formed in the vicinity of the injection port 39a of the single fuel injection valve 39, and the atomization of fuel can be promoted.

  In the above-described embodiment, the air cleaner is described as an example of the intake box. However, the present invention can also be applied to an engine having a surge tank. In this case, an air cleaner is connected to the upstream side of the surge tank, and the downstream side. The intake passage is connected to the second tank, and the second fuel injection valve is disposed in the surge tank.

  In the above embodiment, a four-cylinder engine has been described as an example. However, the present invention can be applied to other multi-cylinder engines and single-cylinder engines.

  Furthermore, in the above-described embodiment, a snowmobile engine has been described as an example. However, the scope of application of the present invention is not limited to this, and for example, a vehicle engine such as a motorcycle, a three- or four-wheeled vehicle for running on rough terrain, and the like. It is also applicable to.

3 Engine 31 Intake Control Valve 31a Valve Plate 31b Valve Shaft 33 Funnel (Cylinder)
33b Curved cylinder part 35 Air cleaner (intake box)
35a First box half 35b Second box half 39 First fuel injection valve 40 Second fuel injection valve 44 Intake passage B Intake passage axis

Claims (7)

An intake box having a predetermined capacity, an intake passage connecting the intake box and the combustion chamber of the engine, an intake control valve interposed in the middle of the intake passage, and downstream of the intake control valve of the intake passage An engine comprising: a first fuel injection valve that supplies fuel to a side; and a second fuel injection valve that supplies fuel upstream of the intake control valve of the intake passage,
The intake passage has a cylindrical portion protruding into the intake box,
The engine is characterized in that the second fuel injection valve injects and supplies fuel to the inside through a wall portion of the protruding portion in the intake box of the cylindrical portion. The engine according to claim 1,
The protruding portion in the intake box of the cylindrical portion has a curved portion that curves toward the upstream side of the intake flow,
2. The engine according to claim 1, wherein the second fuel injection valve is disposed so as to be positioned on a side of the curvature center of the curved portion. The engine according to claim 2,
A portion of the intake passage between the curved portion and the intake port of the engine extends substantially linearly,
The engine is characterized in that the second fuel injection valve injects and supplies fuel substantially along an axis of the substantially straight portion of the intake passage. The engine according to claim 1,
The engine, wherein the second fuel injection valve is disposed outside the intake box and supported by the intake box. The engine according to claim 4,
The intake box has a first box half connected to the intake passage, and a second box half connected to the first box half,
The engine, wherein the second fuel injection valve is supported by the second box half. The engine according to claim 2,
The engine, wherein the first fuel injection valve and the second fuel injection valve are disposed on the same side with respect to the axis of the intake passage. The engine according to claim 1,
The intake control valve is a butterfly type in which a valve plate is fixed to a valve shaft, and the valve plate is inclined so that a portion close to the injection port of the first fuel injection valve is located on a downstream side from a far portion. An engine characterized by being arranged.

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