JP4030065B2 - Fuel injection engine - Google Patents

Description

  The present invention relates to a fuel injection engine.

  In a fuel injection engine, a fuel injection valve is usually provided facing the intake passage on the downstream side of the throttle valve of each cylinder. A trumpet-shaped funnel is attached to the end of the intake passage to take in outside air. This funnel is usually disposed in an intake box that constitutes an air cleaner, and outside air that has been purified through the air cleaner element is sucked into the intake passage through the funnel. In general, when the length of such a funnel is increased, the torque performance in a low rotation range is improved, and when the length is short, the torque performance in a high rotation range is improved.

  In order to improve the output of such a fuel injection engine, an engine has been developed in which a fuel injection valve downstream of the throttle valve is used as a first fuel injection valve and a second fuel injection valve is provided on the intake passage of each cylinder. Has been.

  However, if the second fuel injection valve is provided on the intake pipe constituting the intake passage, the injection port must be opened in the intake pipe of the cast product, and the configuration of the intake pipe itself becomes complicated, and a new casting process In addition, a fuel injection valve and a fuel pipe must be provided in a narrow space around the engine, and space restrictions are large.

  Therefore, a configuration in which the second fuel injection valve is provided in the funnel portion at the end of the intake passage is conceivable. In this case, if the fuel injection valve is provided in the funnel opening surface, the intake resistance due to unevenness or steps in the outer shape of the fuel injection valve Is a problem. In addition, when the funnel is disposed in the air cleaner, there are problems such as leakage due to penetration of the fuel pipe and maintainability.

  The present invention takes the above-described points into consideration, and in an engine having first and second fuel injection valves for one cylinder, the second fuel injection valve is not provided in the intake pipe of the engine. An object of the present invention is to suppress an increase in intake resistance due to the second fuel injection valve.

A fuel injection engine according to the present invention faces an intake passage, a throttle valve provided in the intake passage, and an intake passage downstream of the throttle valve corresponding to each cylinder of the engine having a plurality of cylinders. a first fuel injection valve, and a funnel provided at the upstream end of the intake passage provided with a second fuel injection valve facing the intake passage, a fuel injection type engine provided with an intake box, the funnel is provided in said intake box, smooth outer surface shape that covers the circumferential side surface of said each fuel pipe for supplying fuel to the second fuel injection valve provided in said intake box and the respective second fuel injection valves and a cover, the cover, along the contour of the respective second fuel injection valves, is formed in a shape tapered toward the ejection port side of each second fuel injection valve, the fuel pipe It is assumed to be fixed.

  In the present invention, since the funnel is provided in the intake box such as an air cleaner, the space can be effectively used. Further, since the second fuel injection valve is covered with a cover having a smooth outer shape, an increase in intake resistance can be suppressed.

  FIG. 1 is a configuration diagram showing a main part of a fuel injection valve arrangement structure according to an embodiment of the present invention. The engine 1 is, for example, a four-cylinder engine (only one cylinder is shown), and is provided with a throttle valve 3 in the intake passage 2 for each cylinder, and in the intake passage 2 downstream of the throttle body portion provided with the throttle valve 3. A first fuel injection valve 4 is provided. An air cleaner 5 is provided at the upstream end of the intake passage 2. A funnel 6 connected to the end of the intake passage 2 is provided in the air cleaner 5.

  The air cleaner 5 includes an upper case 5a and a lower case 5b, takes outside air from a duct 7 provided in the upper case 5a, and supplies it to the funnel 6 side through the air cleaner element 8. On the front side of the lower case 5b, there is provided an air intake port 9 for supercharging that is used particularly when traveling at a high output operation. The air intake 9 is normally closed with a cap 10.

  A second fuel injection valve 11 is provided at the enlarged opening end of the funnel 6. The second fuel injection valve 11 is disposed at a position where the injection port portion at the tip of the second fuel injection valve 11 is inserted inward from the opening surface of the funnel 6 in a state where the second fuel injection valve 11 is covered with a curved cover 12 having a smooth outer shape. The cover 12 has a shape that covers the peripheral side surface along the outer shape of the fuel injection valve 11, a small-diameter injection port portion is inserted into the funnel opening surface, and a large-diameter upper portion protrudes outside the funnel opening surface. . More specifically, the smallest diameter portion on the tip side enters the basic diameter portion of the funnel, and the larger diameter portion is positioned so as to correspond to the enlarged diameter portion of the funnel. Thus, by inserting only the small-diameter injection port portion of the fuel injection valve 11 into the funnel 6, the portion that closes the funnel opening surface can be reduced and the increase in intake resistance can be suppressed to a small value.

  The cover 12 is supported by a support member (not shown) to which the cover 12 is attached and a column (not shown) made of a bolt standing from the lower case 5b side, a collar or the like through which the bolt is inserted. A second fuel injection valve 11 for each cylinder is mounted on such a cover 12 and arranged in a row in the cylinder arrangement direction (vertical direction in the drawing).

  A first fuel pipe 13 for supplying fuel to the first fuel injection valve 4 is provided below the air cleaner 5 along the arrangement direction (vertical direction in the drawing) of the first fuel injection valves 4 of each cylinder. It is done. Similarly, a second fuel pipe 14 for supplying fuel to the second fuel injection valve 11 is provided in the air cleaner 5.

  The first fuel pipe 13 has an inlet side end connected to a forward or downstream pipe 15b branched from a fuel supply pipe 15 connected to a fuel pump (not shown), and a fuel return pipe 16b connected to the outlet side end. .

  A forward pipe 15a branched or continuous from the fuel supply pipe 15 is connected to the inlet side end of the second fuel pipe 14, and a return pipe 16a is connected to the outlet side end. The return pipe 16 a is connected to the first fuel pipe 13.

  The forward pipe 15a connected to the second fuel pipe 14 is disposed inside the air cleaner 5 through the side wall of the lower case 5b via a grommet (not shown). The return pipe 16a of the second fuel pipe 14 is disposed outside the air cleaner 5 through the lower wall of the lower case 5b via a grommet (not shown). Since the forward pipe 15a and the return pipe 16a pass through the lower case 5b of the air cleaner 5 through such a sealing member such as a grommet, the sealing performance of the through portion is sufficiently ensured.

  In the fuel piping path having such a configuration, the fuel sent from the fuel pump (not shown) through the fuel supply pipe 15 passes through the first fuel pipe 13 and the first fuel pipe 15b through the forward pipes 15b and 15a branched from the fuel supply pipe 15. 2 is supplied to the fuel pipe 14. The surplus fuel supplied to the first fuel pipe 13 returns to a fuel tank (not shown) through the return pipe 16b. The surplus fuel supplied to the second fuel pipe 14 is supplied to the first fuel pipe 13 through the return pipe 16a, and then returns to the fuel tank through the return pipe 16b.

  2 to 12 show a more detailed embodiment of the present invention. In each figure, the same number is attached | subjected to the part corresponding to each part of the said FIG. 2 is a cross-sectional view of the air cleaner, FIG. 3 is a plan view thereof, and FIG. 4 is a cross-sectional view of the AA portion of FIG.

  The fuel supply pipe 15 connected to the fuel pump 18 (FIG. 2) branches into two forward pipes 15b and 15a for supplying fuel to the first and second fuel pipes 13 and 14, respectively. ) To the fuel pipes 13 and 14. The forward pipe 15a connected to the second fuel pipe 14 penetrates the lower case 5b of the air cleaner 5 through the grommet 17a. Four first fuel injection valves 4 corresponding to each cylinder are attached to the first fuel pipe 13, and the outlet side end portions thereof are connected to the return pipe 16b via the joint 21 (FIG. 3). T indicates the bottom surface of the fuel tank. An air cleaner or the like is disposed in a narrow space below the bottom surface T of the fuel tank.

  Four second fuel injection valves 11 corresponding to the respective cylinders are attached to the second fuel pipe 14, and their outlet side end portions are connected to the return pipe 16 a via the joints 21. As shown in FIG. 4, the return pipe 16 a passes through the lower case 5 b of the air cleaner 5 through the grommet 17 b and is connected to the first fuel pipe 13.

  The second fuel injection valve 11 is mounted in the cover 12 and supported by a support member 22 (see FIGS. 10, 11, and 12 described later) integrally formed with the second fuel pipe 14. The support member 22 is fixedly supported to a flange at the lower part of the funnel by a support column including four bolts 20 and a collar 28 through which the bolts 20 are inserted. An electric wiring 23 is connected to each fuel injection valve via a connector 29 (FIG. 3). The four funnels are individually fixed and supported on the throttle body 2c by bolts 20 '.

  On each pipe constituting the fuel flow path, connecting tools 19a, 19b, 19c for connecting the pipe members are provided. These connecting tools are configured to be connected in a snap-type manner by pushing a pipe. Each pipe has a rigid metal pipe (or a rigid pipe) in order to keep its position fixed, in particular to ensure the sealing performance of the penetration part to the air cleaner and to reduce the pressure loss of the fuel sent from the pump. Large resin material). Accordingly, the connection tools 19a and 19b are close to each other, so it is necessary to attach and detach them together. The connection push-in direction of each connection tool 19 is one in consideration of maintenance workability and the like. It is desirable to arrange them.

  FIG. 5 is a sectional view of the air cleaner alone, and FIG. 6 is a plan view thereof. The upper case 5a and the lower case 5b of the air cleaner 5 have a fitting type configuration in which the concave and convex portions of the mating surfaces along the peripheral edge are fitted and hermetically coupled, and are fixed to each other by screws 25. A seal member 83 for sealingly inserting the upper end portion of the throttle body of the intake passage 2 (FIGS. 1 and 2) is attached to the lower case 5b. The air cleaner element 8 is arranged in a substantially U shape as shown by the oblique lines in FIG. 6 and is attached to the upper case 5 a side by screws 24.

  7 is a plan view of the intake passage (throttle body) and the fuel piping path of the first fuel injection valve, FIG. 8 is a side view thereof, and FIG. 9 is a sectional view taken along line BB in FIG. An intake passage 2 is formed inside, and a throttle body 2c having a throttle valve 3 has a flange portion 2a integrally formed at the bottom thereof, and is attached to the engine side via the flange portion 2a. A fuel injection valve holding frame 2b is integrally formed at a position on the downstream side of the throttle valve 3 in the vicinity of the flange portion 2a, and the injection port portion at the tip of the first fuel injection valve 4 is attached to the holding frame 2b. Is done. Reference numeral 26 (FIG. 9) denotes a connector mounting portion for electrical wiring of the fuel injection valve 4.

  Four throttle bodies 2c are provided in parallel in the vehicle width direction corresponding to four cylinders (not shown) of the engine, and the first fuel pipe 13 is attached along the throttle body 2c. Each first fuel injection valve 4 is attached to the position of each throttle body 2 c of the first fuel pipe 13. As described above, the return pipe 16a from the upper second fuel pipe is connected to the middle of the first fuel pipe 13 (FIG. 8).

  10 is a plan view of the second fuel pipe 14, FIG. 11 is a side view thereof, and FIG. 12 is a cross-sectional view taken along the line CC of FIG. The second fuel pipe 14 is integrally formed with the four arm-shaped support members 22. A bolt through hole 20 a is formed at the tip of the support member 22. The second fuel pipe 14 passes the bolt 20 (FIGS. 2 and 3) through the hole 20a of the support member 22, and the funnel 6 (FIG. 2) on the upper side of the throttle body through the collar 28 (FIGS. 2 and 3). Is supported on the upper side. The cover 12 is attached to the fuel pipe 14 with screws 27 at predetermined intervals corresponding to the positions of the throttle bodies, and the second fuel injection valve 11 is attached. As described above, the cover 12 has a smooth outer surface shape, and covers the second fuel injection valve 11 by exposing the connector mounting portion 26 of the electrical wiring as shown in FIG.

  The bolt 20 and the collar 28 are provided between the funnels. The connector mounting portion 26 and the fuel pipes 15a and 16a are disposed on the opposite side of the filter element 8 with the second fuel passage interposed therebetween. This does not hinder the flow of intake air that passes through the filter element 8 and flows into each funnel.

The block diagram of a fuel-injection-valve arrangement structure. The cross-sectional block diagram of an air cleaner part. The top view of the air cleaner of FIG. Sectional drawing of the AA part of FIG. Sectional drawing of the air cleaner single-piece | unit of the structure of FIG. The top view of the air cleaner of FIG. FIG. 3 is a plan view of a throttle body and a first fuel pipe portion having the structure of FIG. 2. The side view of the structure of FIG. Sectional drawing of the BB part of FIG. The top view of the 2nd fuel pipe part of the structure of FIG. The side view of the fuel pipe of FIG. Sectional drawing of CC part of FIG.

Explanation of symbols

1: Engine 2: Intake passage 3: Throttle valve 4: First fuel injection valve 5: Air cleaner 5a: Upper case 5b: Lower case 6: Funnel 7: Duct 8: Air cleaner element 9: Air intake 10: Cap 11: First 2 fuel injection valve 12: cover 13: first fuel pipe 14: second fuel pipe 15: fuel supply pipe 15a, 15b: forward pipe 16a, 16b: return pipe 17a, 17b: grommet 18: fuel pump 19: connector 20 : Bolt 21: Joint 22: Support member 23: Electrical wiring 24, 25, 27: Screw 26: Connector holding part 28: Collar 29: Connector

Claims (4)

Corresponding to each cylinder of an engine having a plurality of cylinders, an intake passage, a throttle valve provided in the intake passage, a first fuel injection valve facing the intake passage on the downstream side of the throttle valve, and the intake passage In a fuel injection type engine provided with a funnel provided at the upstream end of the second fuel injection valve and a second fuel injection valve facing the intake passage, and provided with an intake box,
The funnel is provided in the intake box,
A fuel pipe for supplying fuel to each of the second fuel injection valves;
A cover having a smooth outer surface provided in the intake box and covering a peripheral side surface of each of the second fuel injection valves ,
The cover is formed in a tapered shape along the outer shape of each second fuel injection valve toward the injection port side of each second fuel injection valve, and is fixed to the fuel pipe. .   The fuel-injection engine according to claim 1, wherein the cover is disposed inside the funnel opening when viewed from the opening direction of the funnel. 2. The fuel injection engine according to claim 1, wherein the cover is attached to the fuel pipe with screws at predetermined intervals corresponding to positions of the intake passages .   The fuel injection engine according to claim 1, wherein the cover and the intake box are configured by separate members.

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