JP5180686B2 - Fuel injection device for backbone type motorcycle - Google Patents

Description

The present invention is, half straight portion Ru extends linearly from the head pipe supporting a front fork inclined rearwardly downward, between straight portion and both straight portions late extending linearly rearward downward from the gentle slope the half linear portion a backbone consisting of an intermediate bent portion which continuously connected, constitute a body frame with a rear frame for supporting the re Ahu forks attached integrally to the rear end of the backbone, to the rear frame, below the backbone Attach an engine that causes the cylinder block and cylinder head to protrude substantially horizontally toward the front, and between the intake port opened on the upper surface of the cylinder head and the air cleaner disposed at the front end of the backbone, It is connected via an intake passage that is arranged at the bottom and tilts backward and downward, and is connected to the middle of the intake passage. The liters valve provided, the backbone, the cylinder block, a cylinder head, a fuel injection device in the backbone-type motorcycle fitted with a leg shield for covering the air cleaner and the intake passage on the body frame.

Such a backbone type motorcycle is widely used worldwide as a small motorcycle with the trade name “Super Cub” related to the manufacture of the applicant company. In this case, a vaporizer is installed in the middle of the intake passage. (For example, see Patent Document 1 below).
Japanese Utility Model Publication No. 62-39993

  In the backbone type motorcycle described above, if the fuel injection valve is attached to the intake passage instead of the carburetor without changing the body frame or the engine layout, the injected fuel is supplied from the fuel injection valve to the cylinder head of the engine. In order to be surely directed to the intake port that opens on the upper surface of the intake passage, it must be attached to the upper side wall of the intake passage. However, since the backbone of the frame is disposed relatively close above the intake passage, the fuel injection valve easily interferes with the backbone and cannot be easily attached to the upper side wall of the intake passage. .

  Therefore, the present invention can attach the fuel injection valve to the upper side wall of the intake passage without interfering with the backbone of the body frame without changing the layout of the conventional body frame and engine. It is an object of the present invention to provide a fuel injection device for the backbone type motorcycle that can inject fuel toward an intake port of a cylinder head.

To achieve the above object, the present invention is the first half straight portion Ru extends linearly from the head pipe supporting a front fork inclined rearwardly downward, extends straight rearward downward from the gentle slope the half linear portion a backbone consisting of an intermediate bent portion which continuously connects the second half linear portion and both straight portions, constitute a body frame with a rear frame for supporting the re Ahu forks attached integrally to the rear end of the backbone, the An engine that causes the cylinder block and the cylinder head to protrude forward in a substantially horizontal direction below the backbone is attached to the rear frame, and an intake port that opens to the upper surface of the cylinder head and an air cleaner disposed at the front end of the backbone And an intake passage that is disposed below the backbone and is inclined rearward and downward. The throttle valve provided in an intermediate portion of the intake passage, the backbone, the cylinder block, a cylinder head, in the backbone-type motorcycle mounted a leg shield for covering the air cleaner and the intake passage on the body frame, the intake passage, the cylinder head A first bent portion that bends forward along the backbone while rising from the upper surface of the air cleaner, a second bent portion that bends rearward along the backbone while descending from the lower surface of the air cleaner, and the first and second bent portions A straight portion extending linearly to connect the two, and standing on the upper end wall of the first bent portion of the intake passage on the downstream side of the throttle valve, toward the intake port of the cylinder head. downward the fuel injection valve for injecting fuel, and it intermediate below said backbone Te Disposed forward of the midpoint of the outer curve of the curved portion, the lower extension axis extending in the vertical direction of the fuel injection valve and the axis of the intake valve for opening and closing the downstream end of the intake port intersects within the intake port and thus, the fuel injection valve a fuel supply pipe connected to the upper end of the upstream end portion side of it sloped arranged along the lower side of the backbone so that the rear downward, the upstream end of the fuel supply pipe A fuel conduit arranged along the backbone and connected to a fuel pump is connected to the upper portion of the fuel injection valve and the fuel supply pipe. The upper portion of the fuel injection valve and the fuel supply pipe are connected to the backbone, the lower portion is connected to the cylinder head, and the front surface is connected to the intake passage. Thus, the first feature is that the left and right side portions are respectively covered with the leg shield.

The present invention, in addition to the first feature, placed with the the straight portion of the intake passage line for disposing the throttle valve, the throttle valve, in the horizontal direction where the rotation axis is perpendicular to the axis of said backbone And a boss having a horizontal upper end surface and a vertical mounting hole opening in the upper end surface on the upper side wall of the first bent portion facing the intake port. A second feature is that the lower end portion of the fuel injection valve is fitted into the mounting hole, and the lower end surface where the fuel injection hole opens faces the intake passage of the first bent portion. To do .

The intermediate bent portion of the intake pipe 23 in the embodiment corresponds to the first bent portion of the present invention, and the intermediate bent portion of the horn tube 22 in the embodiment corresponds to the second bent portion of the present invention. The intake passage 24a corresponds to the straight portion of the present invention.

According to the first feature of the present invention, the intake passage connecting the air cleaner and the intake port is bent forward along the backbone while rising from the upper surface of the cylinder head so as to secure a space between the intake passage and the backbone. A first bent portion, a second bent portion bent rearward along the backbone while descending from the lower surface of the air cleaner, and a straight portion extending along the backbone to connect the first and second bent portions. As a result, the space between the intake passage and the backbone is secured , and the small space between the backbone and the intake passage can be used rationally without changing the layout of the conventional body frame or engine. The fuel injection valve attached to the upper side wall of the intake passage is accommodated together with the fuel supply pipe, while the fuel injection valve is in a substantially horizontal posture. Fuel can be injected downward toward the intake ports of the cylinder head.

Moreover the intake passage, as the whole will be tilted backwards downwards, can contribute to improvement in output of the engine E by reducing the intake resistance.

Further, a fuel supply pipe connected to the upper end of the fuel injection valve, to tilt disposed along the lower side of the backbone to the upstream end side of it is rear downward Runode, the fuel supply pipe, the backbone and the fuel injection It can be easily arranged in a narrow space between the valves without being interfered by the backbone. Since fuel conduit connected to the upstream end of the fuel supply pipe is disposed along the backbone, it no fuel conduit out seen largely from the backbone, is possible to easily avoid interference with other products it can.

Embodiments of the present invention will be described below based on examples of the present invention and reference examples shown in the accompanying drawings.

1 to 4 show a reference example of the present invention, FIG. 1 is a side view of a backbone type motorcycle, FIG. 2 is a side view of an engine and an intake system around the motorcycle, and FIG. 3 is an intake view of FIG. enlarged side view showing around a fuel injection device in the system, Figure 4 is 4 arrow view of FIG. 3, FIG. 5 is a real施例shows a similar side view to FIG. 3 of the present invention.

First, a reference example of the present invention will be described with reference to FIGS. In FIG. 1, a vehicle body frame F of a motorcycle M is welded to the rear side surface of the head pipe 1 at the front end, and is welded to a backbone Ff made of a steel pipe extending obliquely rearward and downward, and to the rear end of the backbone Ff. A rear frame Fr made of a steel plate is configured. A front fork 2 that pivotally supports the front wheel Wf is pivotally supported on the head pipe 1 and a rear fork 3 that pivotally supports the rear wheel Wr is pivotally supported on the rear frame Fr. The rear cushion 4 is connected between the rear frames Fr. A saddle 5 is attached to the upper surface of the rear frame Fr, and the fuel tank 6 is housed and held in the rear frame Fr immediately below the saddle 5. Furthermore, the crankcase 7 of the engine E is attached to the front end of the rear frame Fr below the connection point with the backbone Ff. The engine E has a cylinder block 8 that protrudes from the front surface of the crankcase 7 and is disposed substantially horizontally, and a cylinder head 9 is joined to the front surface of the cylinder block 8. An air cleaner 10 is attached to the front end portion of the backbone Ff, and the air cleaner 10 is connected to an intake port (see FIG. 2) of the cylinder head 9 via an intake passage 12 disposed below the backbone Ff.

  The backbone Ff, the cylinder block 8, the cylinder head 9, the air cleaner 10, and the intake passage 12 are covered with a leg shield 13 attached to the vehicle body frame F.

  As shown in FIGS. 2 and 3, the backbone Ff is coupled to the head pipe 1 and has a front half straight line portion 14a inclined downward and downwardly extending linearly, and a lower slope with a lower inclination than the front half straight line portion 14a. The second straight line portion 14b that extends linearly and is coupled to the rear frame Fr, and the intermediate bent portion 14c having a radius of curvature R that continuously couples the two straight line portions 14a and 14b. The cylinder head 9 is located below the intermediate bent portion 14c, and the intake port 11 is opened on the upper surface of the cylinder head 9. An opening end of the intake port 11 to the combustion chamber 16 is opened and closed by an intake valve 15.

  The air cleaner 10 includes a cleaner case 17 that is disposed immediately below the front straight line portion 14a of the backbone Ff and has a front surface opened, a case cover 18 that is coupled to the cleaner case 17 and closes the open surface, and the cleaner case 17 and The cleaner element 19 is sandwiched between the case covers 18 and an inlet duct 20 connected to the upper end of the case cover 18. A connection hole 21 for the intake passage 12 is provided in the bottom wall of the cleaner case 17. Then, the inlet duct 20 and the cleaner case 17 are screwed to the front half straight portion 14a of the backbone Ff.

  The above is no different from the layout of a conventional small motorcycle.

The intake passage 12 includes a horn pipe 22 that is fitted into the connection hole 21 and enters the cleaner case 17, an intake pipe 23 that is coupled to the upper surface of the cylinder head 9 to communicate with the intake port 11, and A throttle body 24 is connected between the horn pipe 22 and the intake pipe 23. The horn tube 22 has an obtuse bent portion in the middle and has a substantially L shape with the downstream opening end facing backward and downward. The intake pipe 23 also has an obtuse bent portion in the middle and has an upstream opening end. the has a substantially L-shape with the front upwards. That is, the intake pipe 23 is then flexion song forward along the backbone Ff while rising from the upper surface of the cylinder head 9, in particular, the bent is started from the joint surface between the cylinder head 9. A space S is secured between the bent intake pipe 23 and the backbone Ff. The throttle body 24 arranged to be inclined so as to connect the pipes 22 and 23 has a straight intake passage 24a communicating with the inside of the pipes 22 and 23, and is a butterfly type that opens and closes the intake passage 24a. The throttle valve 25 is pivotally supported on the throttle body 24 with its rotating shaft 25a oriented in a horizontal direction perpendicular to the axis Y of the backbone Ff. The intake pipe 23 is formed such that the joint surface with the upper surface of the cylinder head 9 and the joint surface with the downstream end of the throttle body 24 form an acute angle. In this way, the intake passage 12 is disposed substantially along the backbone Ff.

An electromagnetic fuel injection valve 30 is erected on the upper side wall of the bent portion of the substantially L-shaped intake pipe 23. That is, a boss 27 having a horizontal upper end surface and a vertical valve mounting hole 26 opened at the upper end surface is integrally formed on the upper side wall of the bent portion of the intake pipe 23. The lower end portion of the fuel injection valve 30 is fitted through the seal member 28. A fuel inlet is formed at the upper end surface of the fuel injection valve 30 and a fuel injection hole is opened at the lower end surface. The lower end surface of the fuel injection valve 30 faces the intake pipe 23. The fuel injection valve 30 is arranged such that a vertically extending downward axis J extending in the vertical direction and an axis V of the intake valve 12 intersect in the intake port 11, and the injected fuel 31 from the fuel injection hole is supplied to the fuel injection valve 30. The intake port 11 is directed toward the downstream end that is opened and closed by the intake valve 15 in particular. Further, the fuel injection valve 30 is arranged such that the upper end thereof is in front of the midpoint 32 of the outer curve 14ca in the intermediate bent portion 14c of the backbone Ff.

As shown in FIGS. 3 and 4, a mounting hole 35 that opens to the side wall of the fuel supply pipe 34 is fitted to the upper end portion of the fuel injection valve 30 via a seal member 36. The fuel supply pipe 34 is disposed directly below the backbone Ff and perpendicular to the axis Y of the backbone Ff, that is, in the left-right direction of the vehicle body. A fuel conduit 39 connected to a discharge port of a fuel pump 38 (see FIG. 1) disposed in the fuel tank 6 is connected to one end of the fuel supply pipe 34, and an injection pressure regulator 40 is connected to the other end. Are concatenated. Thus, the fuel injection valve 30 erected on the upper wall of the intake pipe 23 and the fuel supply pipe 34 connected to the upper end of the fuel injection valve 30 are located below the backbone Ff and the intermediate bent portion 14c thereof. Is arranged in front of the midpoint 32 of the outer curve 14ca , and the fuel supply pipe 34 is accommodated in the space S while facing the lower surface of the backbone Ff. The upper portions of the fuel injection valve 30 and the fuel supply pipe 34 are covered by the backbone Ff, the lower portion thereof is covered by the cylinder head 9, the front surface thereof is covered by the intake passage 12, and the left and right side portions thereof are covered by the leg shield 13.

As shown in FIG. 4, the injection pressure regulator 40 includes a regulator body 42 having a fuel chamber 41 communicating with the fuel supply pipe 34, and a cap 44 having a boost negative pressure chamber 43 and coupled to the regulator body 42. And a diaphragm 45 that is sandwiched between the regulator body 42 and the cap 44 and partitions the fuel chamber 41 and the boost negative pressure chamber 43. A valve seat 47 in which a fuel return hole 46 is opened is provided at the center of the regulator body 42, and a valve body 48 that can be seated on the valve seat 47 is attached to the center of the diaphragm 45 so as to swing. A valve spring 49 that urges the valve body 48 toward the valve seat 47 via the diaphragm 45 is accommodated in the boost negative pressure chamber 43. The boost negative pressure chamber 43 communicates with the intake pipe 23 via a negative pressure conduit 50, and the fuel return hole 46 communicates with the fuel tank 6 via a fuel return pipe 51. Further, a fuel filter 52 is provided in the fuel chamber 41.

Next, the operation of this reference example will be described.

  During operation of the engine E, the fuel in the fuel tank 6 is pumped into the fuel chamber 41 of the injection pressure regulator 40 through the fuel conduit 39 and the fuel supply pipe 34 by the fuel pump 38, and the fuel pressure causes the valve body 48 to be seated in the valve seat 48. Acts on the diaphragm 45 in a direction away from the diaphragm 47. On the other hand, the boost negative pressure in the intake pipe 23 is introduced into the boost negative pressure chamber 43 through the negative pressure conduit 50, and this boost negative pressure causes the valve body 48 to act as a valve seat, contrary to the load direction of the valve spring 49. Acts on the diaphragm 45 in a direction away from the diaphragm 47. Therefore, when the load on the engine E is small and the boost negative pressure is high, the valve opening pressure of the valve body 48 by the fuel in the fuel chamber 41 is low, and when the load on the engine E is large and the boost negative pressure is low, the fuel chamber The valve opening pressure of the valve body 48 due to the fuel 41 becomes high, and when the valve body 48 is opened, it returns to the fuel tank 6 through the fuel return pipe 51 that has flowed out of the fuel chamber 41 into the fuel return hole 46. Thus, the fuel pressure in the fuel supply pipe 34 is controlled according to the load of the engine E.

  Thus, during the intake stroke of the engine E, when the intake valve 15 is opened and the fuel injection valve 30 is excited and opened, the pressure-controlled fuel is injected from the valve 30 as described above. Since 31 is directed to the downstream end of the intake port 11 opened by the intake valve 15, the intake port 11 is efficiently sucked into the fuel chamber 41 together with the intake air filtered by the air cleaner 10 and flowing down the intake passage 12. Therefore, there is little loss due to adhesion of the injected fuel 31 to the pipe wall, which can contribute to reduction of fuel consumption. In addition, the intake passage 12 connecting the air cleaner 10 and the intake port 11 is only inclined by the horn pipe 22 and the intake pipe 23 at an obtuse angle, and as a whole is inclined backward and downward, the intake resistance is reduced, and the engine E Can contribute to the improvement of the output.

Incidentally, the fuel injection valve 30 is erected on the upper wall of the bent portion of the intake pipe 23, valve 3 0 is arranged to come in front of the midpoint 32 of the outer curve in the intermediate bent portion 14c of the backbone Ff Therefore, without changing the layout of the conventional vehicle body frame F or engine E, the fuel injection valve 30 is provided on the upper wall of the intake passage 12 by rationally using the small space S between the backbone Ff and the intake passage 12. Therefore, fuel can be injected from the valve 30 toward the intake port 11 particularly toward the downstream end as described above.

  In addition, the fuel supply pipe 34 connected to the upper end of the fuel injection valve 30 is disposed horizontally and perpendicular to the axis of the backbone Ff, so that the fuel supply pipe 34 is disposed in a narrow space between the backbone Ff and the fuel injection valve 30. It can be easily arranged without being interfered by the backbone Ff.

Next, referring to FIG. 5, described real施例of the present invention.

In the real施例this, the fuel supply pipe that will be connected to the upper end of the fuel injection valve 30 (34), that the upstream end side of which is arranged in an inclined manner along the lower side of the backbone Ff such that the rear downward A fuel conduit 39 arranged along the backbone Ff is connected to the upstream end of the fuel supply pipe 34, and a regulator body 42 of the injection pressure regulator 40 is integrally connected to the front end of the fuel supply pipe 34. except that is, a pre-Symbol reference example similar arrangement, in the figure, the parts corresponding to the previous SL reference example are denoted by the same reference numerals, and description thereof is omitted.

Thus, since the fuel supply pipe 34 is inclined along the lower side surface of the backbone Ff so that the upstream end side thereof is rearward and downward, also in this case, between the backbone Ff and the fuel injection valve 30. The fuel supply pipe 34 can be easily disposed in a narrow space without being interfered by the backbone Ff. Since fuel conduit 39 connected to the rear end of the fuel supply pipe 34 is disposed along the backbone Ff, it without the fuel conduit 39 is out largely viewed from the backbone Ff, easily interfere with other product It can be avoided.

  The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention.

1 is a side view of a backbone type motorcycle showing a first embodiment of the present invention. Fig. 2 is a side view around the engine and the intake system of the motorcycle. FIG. 3 is an enlarged side view around a fuel injection device in the intake system of FIG. 2. FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3. The side view similar to FIG. 3 which shows 2nd Example of this invention.

E ... Engine F ... Body frame Ff ... Backbone Fr ... Rear frame J ... Lower extension axis S of fuel injection valve S ... Space V ······· Intake valve axis Y ··· Backbone axis 1 ··· Head pipe 2 ··· Front fork 3 ··· Rear fork 8 · · · Cylinder block 9 ... Cylinder head 10 ... Air cleaner 11 ... Intake port 12 ... Intake passage 14a ... First half straight part 14b ... Second half straight part 14c ... Intermediate bent part 14ca・ Lower surface 15 of the intermediate bent portion .... Intake valve
22 ··· Second bent part (intake pipe)
23 ··· First bent part (horn tube)
24a ... straight section (intake passage)
25 ... Throttle valve 30 ... Fuel injection valve 34 ... Fuel supply pipe
38 ... Fuel pump
39 ... ・ Fuel conduit

Claims (2)

Half straight portion from a head pipe (1) Ru extend linearly inclined rearwardly downward to support the front fork (2) (14a), extending linearly rearward downward from the gentle slope the half linear portion (14a) A backbone (Ff) composed of a rear half straight portion (14b) and an intermediate bent portion (14c) continuously connecting the two straight portions (14a, 14b) and a rear end of the backbone (Ff) are integrally coupled. configure the vehicle body frame out with the rear frame (Fr) (F) for supporting the re Ahu forks (3), that the rear frame (Fr), the backbone (Ff) of the cylinder block (8) below and the cylinder head ( 9) An engine (E) that projects substantially horizontally toward the front is mounted, and an intake port (11) that opens to the upper surface of the cylinder head (9), and the backbone (F ) Is connected to an air cleaner (10) disposed at the front end portion via an intake passage (12) disposed below the backbone (Ff) and inclined substantially rearwardly downward. ) Is provided with a throttle valve (25), and a leg shield (13) covering the backbone (Ff), cylinder block (8), cylinder head (9), air cleaner (10) and intake passage (12) is provided. In the backbone type motorcycle mounted on the body frame (F),
A first bent portion (23) that bends forward along the backbone (Ff) while rising from the upper surface of the cylinder head (9) while descending from the lower surface of the air cleaner (10). A second bent portion (22) bent backward along the backbone (Ff) and a linear portion (24a) extending linearly to connect the first and second bent portions (22, 23). Configure
The intake passage (12) is erected on the upper end wall of the first bent portion (23) on the downstream side of the throttle valve (25) toward the intake port (11) of the cylinder head (9). A fuel injection valve (30) for injecting fuel downward is disposed below the backbone (Ff) and in front of the midpoint (32) of the outer curve (14ca) of the intermediate bend (14c) ; A vertically extending axis (J) extending in the vertical direction of the fuel injection valve (30) and an axis (V) of the intake valve (15) for opening and closing the downstream end of the intake port (11) are inside the intake port (11). Cross at
A fuel supply pipe (34) connected to the upper end of the fuel injection valve (30) is inclined along the lower side surface of the backbone (Ff) so that the upstream end side thereof faces downward and rearward. A fuel conduit (39) arranged along the backbone (Ff) and connected to the fuel pump (38) is connected to the upstream end of the supply pipe (34) ,
The upper part of the fuel injection valve (30) and the fuel supply pipe (34) is provided by the backbone (Ff), the lower part thereof is provided by the cylinder head (9), the front surface thereof is provided by the intake passage (12), and the left and right side parts thereof are provided. A fuel injection device for a backbone type motorcycle, which is covered with the leg shield (13). In the fuel injection device for a backbone type motorcycle according to claim 1,
The throttle valve (25) is disposed in the straight portion (24a ) of the intake passage (12 ), and the throttle valve (25) is arranged so that the rotation shaft (25a) is orthogonal to the axis of the backbone (Ff). A horizontal butterfly type structure is provided, and an upper side wall of the first bent portion (23) facing the intake port (11) is provided with a horizontal upper end surface and a vertical direction opening to the upper end surface. A boss (27) having a mounting hole (26) is integrally formed, and a lower end portion of the fuel injection valve (30) is fitted into the mounting hole (26) so that the fuel injection hole is opened. characterized in that the end face has to face the intake passage (12) in said first bent portion (23), the fuel injection equipment in backbone type motorcycle.

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