fuel supply unit

Abstract

The present invention comprises: a fuel delivery pipe 35 that extends along the direction in which cylinders of an engine are arranged and that supplies fuel to a plurality of fuel injection valves; a pulsation damper 40 that is installed to a side surface of the fuel delivery pipe 35 and absorbs fluctuations in the pressure of the fuel in the fuel delivery pipe 35; and a damper pressing plate 50 that fixes the fuel delivery pipe 35 and the pulsation damper 40. The damper pressing plate 50 is configured from a U-shaped first plate 51 that is disposed so as to wrap around the fuel delivery pipe 35 and the pulsation damper 40, and a second plate 42 that supports the pulsation damper 40. The first plate 51 and the second plate 52 are fixed with a snap-fit-type fixation part such that the pulsation damper 40 is fixed and biased toward the fuel delivery pipe 35.

Description

Technical Field

[0001] The present invention relates to a fuel supply device for an engine, and more particularly to an attachment structure of a pulsation damper in a fuel delivery pipe.

Background Art

[0002] An engine mounted on a motorcycle or the like is provided with a throttle device having a throttle valve in an intake passage in order to control the intake air amount. In addition, in a throttle device used for an engine of a motorcycle or the like, a throttle device provided with a fuel injection valve in an intake passage near the throttle valve is often used. On the other hand, in a multi-cylinder engine, fuel is distributed and supplied from a fuel tank to fuel injection valves of respective cylinders through a fuel delivery pipe. For example, Patent Documents 1 and 2 describe a fuel delivery type for a four-cylinder engine. The fuel delivery types of Patent Documents 1 and 2 are tubular passages that distribute and supply fuel to four fuel injection valves. Fuel is supplied from one end of the fuel delivery type, and fuel is supplied to the fuel injection valves of respective cylinders from four discharge ports provided on the side surface. Furthermore, the fuel delivery pipes of Patent Documents 1 and 2 are provided with a pulsation damper that absorbs fluctuations in the pressure of fuel in the fuel delivery pipe. In Patent Document 1, a pulsation damper is provided inside an end portion of the fuel delivery pipe. In Patent Document 2, a pulsation damper is provided on the side surface of the fuel delivery pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

[0004] However, as described in Patent Document 1, if a pulsation damper is to be installed within the end of the fuel delivery pipe, it is difficult to install a large pulsation damper. Furthermore, if a relatively large pulsation damper is to be installed at the end of the fuel delivery pipe, the entire throttle device may become larger. In Patent Document 2, the pulsation damper is a separate unit from the fuel delivery pipe so that it can be easily replaced. In Patent Document 2, the pulsation damper is installed by inserting a projection with a fuel intake port at its tip into a mounting hole provided on the side of the fuel delivery pipe. Furthermore, a clip is used to prevent the pulsation damper from falling out of the fuel delivery pipe.

[0005] However, in the mounting structure for the pulsation damper described in Patent Document 2, a clip is inserted from the side onto the protruding part of the pulsation damper to secure it. This structure may make it difficult to attach and detach the clip due to obstructions from surrounding structures. Furthermore, vibrations may cause the pulsation damper to move in the attachment / detachment direction relative to the fuel delivery pipe.

[0006] The present invention has been made in view of these problems, and its objective is to provide a fuel supply device that allows for easy attachment and detachment of a pulsation damper to a fuel delivery pipe, as well as secure fixation, and that is also miniaturized. [Means for solving the problem]

[0007] To achieve the above objective, the fuel supply device of the present invention comprises: a fuel delivery pipe extending in a predetermined direction and having a fuel supply passage inside, which supplies fuel to the fuel injector of an engine; a pulsation damper installed on the side of the fuel delivery pipe and absorbing fluctuations in the fuel pressure in the fuel supply passage; and a damper fixing device that wraps around the fuel delivery pipe and the pulsation damper, pressing down on the fuel delivery pipe and the pulsation damper, and fixing the fuel delivery pipe and the pulsation damper, wherein the damper fixing device is The system comprises a U-shaped first fixing device installed around the fuel delivery pipe in a lateral direction relative to its extension direction, and a second fixing device that supports the pulsation damper, It has a snap-fit ​​fastening section, The fixing portion fixes the first fixing device and the second fixing device, so that the first fixing device and the second fixing device surround the fuel delivery pipe and the pulsation damper. The pulsation damper is biased toward the fuel delivery pipe by the fixing part, and the pulsation damper is detachably fixed to the fuel delivery pipe. It is characterized by the following:

[0009] Preferably, the first fastener is made of an elastic material and is bent in the direction in which the pulsation damper is attached to the fuel delivery pipe.

[0010] Preferably, the fuel delivery pipe extends along a plurality of fuel injectors arranged at intervals in the predetermined direction, and the pulsation damper is installed between adjacent fuel injectors.

[0011] Preferably, the fuel injection device and the fuel delivery pipe are fixed to a throttle device that controls the intake air volume of the engine. [Effects of the Invention]

[0012] According to the fuel supply device in the fuel delivery pipe of the present invention, by providing a pulsation damper on the side of the fuel delivery pipe, it is possible to incorporate a relatively large pulsation damper while keeping the overall length of the fuel supply device down. The damper mounting fixture that secures the pulsation damper to the side of the fuel delivery pipe is, The fuel delivery pipe and the pulsation damper are surrounded by the first and second fixing devices.The pulsation damper is fixed by a snap-fit fixing portion, so that the pulsation damper can be easily and removably fixed. In addition, by adopting the snap-fit fixing portion, the damper fixture can be made compact, and the entire fuel supply device can be made compact.

Brief Description of the Drawings

[0013] [Figure 1] It is an external view of a throttle device adopting the pulsation damper mounting structure of an embodiment of the present invention. [Figure 2] It is a perspective view showing the structure of the attachment portion of the pulsation damper in the fuel delivery pipe. [Figure 3] It is a longitudinal sectional view of the attachment portion of the pulsation damper. [Figure 4] It is a side view of the damper pressing plate. [Figure 5] It is a top view of the damper pressing plate. [Figure 6] It is a side view of the damper pressing plate in the state of supporting the pulsation damper.

Mode for Carrying Out the Invention

[0014] Hereinafter, an embodiment of the present invention will be described based on the drawings.

[0015] FIG. 1 is an external view of a throttle device adopting the pulsation damper mounting structure of an embodiment of the present invention. FIG. 2 is a perspective view showing the structure of the attachment portion of the pulsation damper in the fuel delivery pipe. FIG. 3 is a longitudinal sectional view of the attachment portion of the pulsation damper in the fuel delivery pipe. Note that FIG. 3 is a sectional view of the A-A portion described in FIG. 2.

[0016] The throttle device 10 adopting the pulsation damper mounting structure of the present invention is a multi - type throttle device that is mounted on a multi - cylinder engine and controls the intake air amount. The throttle device 10 of the present embodiment is adopted for an in - line four - cylinder engine mounted on a vehicle such as a motorcycle. In the engine, four cylinders (♯1 to ♯4), not shown, are arranged in order in the vehicle width direction (left - right direction). The throttle device 10 is a throttle device for two adjacent cylinders and two are provided for the engine. The throttle devices 10 are arranged in two along the cylinder arrangement.

[0017] As shown in FIG. 1, the throttle device 10 includes a throttle body 14 in which intake passages 13a for the ♯1 cylinder and 13b for the ♯2 cylinder are formed.

[0018] A reduction mechanism 20 is provided on one side surface of the throttle body 14. A motor 17 is connected to the reduction mechanism 20.

[0019] The throttle device 10 further includes a throttle shaft (not shown), throttle valves 16a and 16b, and a throttle position sensor 22. A throttle valve 16a is provided in the intake passage 13a, and a throttle valve 16b is provided in the intake passage 13b.

[0020] The intake passages 13a and 13b are formed to extend perpendicular to the left - right direction (the front - rear direction described in FIG. 1), which is the direction in which the cylinders are arranged. The throttle shaft passes through the throttle body 14 and extends in the left - right direction, passes through the two intake passages (13a, 13b), and is rotatably supported by the throttle body 14.

[0021] The throttle valves 16a and 16b are disc-shaped members with approximately the same diameter as the inner diameter of the intake passages 13a and 13b, fixed to the throttle shaft, and positioned within the intake passages 13a and 13b. The throttle valves 16a and 16b rotate within the intake passages 13a and 13b as the throttle shaft rotates, and are capable of rotating to any angle between a closed position that closes the intake passages 13a and 13b and an open position that opens the intake passages 13a and 13b.

[0022] Motor 17 is an electric motor. Motor 17 is fixed to the throttle body 14, and a rotary drive shaft (not shown) is positioned parallel to the throttle shaft.

[0023] The reduction mechanism 20 has multiple gears inside and reduces the rotation of the motor 17's rotational drive shaft to rotate the throttle shaft.

[0024] The throttle position sensor 22 is located at one end of the throttle shaft and has the function of detecting the rotation angle of the throttle shaft 15. The throttle position sensor 22 is located, for example, in the throttle body 14.

[0025] Furthermore, the throttle device 10 is equipped with a fuel injector 30 (fuel injector). A fuel injector 30 is provided for each cylinder and is located near the intake passages 13a and 13b (upper part in Figure 1). The injection port 30a of the fuel injector 30 is located near the downstream side of the throttle valves 16a and 16b and opens toward the intake passages 13a and 13b.

[0026] The throttle device 10 is equipped with a fuel delivery pipe 35 adjacent to the throttle body 14. The fuel delivery pipe 35 is a tubular member that extends in the left-right direction (a predetermined direction) in the direction in which the intake passages 13a and 13b are aligned, near the fuel injection valve 30.

[0027] Near the end of the fuel delivery pipe 35 opposite to the reduction mechanism 20, there is an inlet 36 into which fuel flows. Two fuel injector mounting sections 37, each having a fuel discharge port, are provided on the side of the fuel delivery pipe 35, and the end of the fuel injector 30 opposite to the nozzle 30a is fixed to these fuel injector mounting sections 37. The fuel injector mounting sections 37 on the fuel delivery pipe 35 are spaced apart from each other in the axial direction of the fuel delivery pipe 35, in accordance with the left and right positions of the fuel injector 30, that is, in accordance with the left and right positions of the intake passages 13a and 13b.

[0028] Furthermore, a pulsation damper 40 is attached to the fuel delivery pipe 35. The pulsation damper 40 is positioned on the side of the fuel delivery pipe 35, and is located on the left and right sides between the intake passage 13a and the intake passage 13b.

[0029] As shown in Figures 2 and 3, the pulsation damper 40 has a cylindrical shape and a projection 45 that protrudes at one axial end and is equipped with an intake port for taking in fuel at its tip. The pulsation damper 40 is a known component, and a detailed explanation of its internal structure will be omitted, but for example it has a diaphragm that divides the internal space into two spaces, and the diaphragm moves in response to pressure fluctuations in one of the spaces that communicate with the intake port, thereby absorbing the pressure fluctuations in that space. The side surface of the pulsation damper 40 is provided with a ring-shaped flange portion 46 for support.

[0030] A damper mounting section 38 for attaching a pulsation damper 40 is provided on the side of the fuel delivery pipe 35. The damper mounting section 38 has a circular opening 48 into which the protruding portion 45 of the pulsation damper 40 is inserted. The opening 48 communicates with the fuel supply passage 49 inside the fuel delivery pipe 35. The opening 48 is closed when the protruding portion 45 of the pulsation damper 40 is inserted. The outermost edge of the opening 48 has a smaller diameter than the flange portion 46 of the pulsation damper 40.

[0031] The pulsation damper 40 is supported on the fuel delivery pipe 35 by a damper retaining plate 50 (damper fixing device).

[0032] Figure 4 is a side view of the damper retaining plate 50. Figure 5 is a top view of the damper retaining plate 50. Figure 6 is a side view of the damper retaining plate 50 in the supported state of the pulsation damper 40. In Figure 6, the damper retaining plate 50 in the supported state of the pulsation damper 40 is shown by a solid line, and the damper retaining plate 50 in the state before the pulsation damper 40 is supported is shown by a dashed line.

[0033] As shown in Figures 4 and 5, the damper retaining plate 50 is composed of a first plate 51 (first fixing device) and a second plate 52 (second fixing device). The first plate 51 is formed by bending a plate-shaped member, which is narrower than the pulsation damper 40, into a roughly U-shape. The first plate 51 is formed by folding it around the fuel delivery pipe 35 and the damper mounting portion 38 along the side opposite the opening 48. A support hole 53 is provided in the central part of the first plate 51 in the extension direction, i.e., the bottom of the U-shape. The support hole 53 is inserted into a protrusion 54 provided on the side of the fuel delivery pipe 35, and the axial position of the damper retaining plate 50 relative to the fuel delivery pipe 35 is defined.

[0034] Rectangular holes 55a and 55b are formed at both ends of the first plate 51 to support both ends of the second plate 52.

[0035] The second plate 52 is formed from an elastic material, such as a plate-shaped steel material. The second plate 52 has a ring-shaped plate-shaped main body 56 in the center that presses against the flange portion 46 of the pulsation damper 40, and a pair of projections 57a and 57b that protrude radially outward from the main body 56 in opposite directions. The tip of one projection 57a ​​is inserted into one of the holes 55a of the first plate 51, locking the first plate 51 and the second plate 52 together. As shown in Figure 6, the projection 57a ​​and the hole 55a support the second plate 52 so that it can swing relative to the first plate 51.

[0036] The tip of the other projection 57b of the second plate 52 is inserted into the other hole 55b of the first plate 51 and is detachably supported. The projection 57b of the second plate 52 and the hole 55b of the first plate 51 have a snap-fit ​​fixing structure that provides elastic support when inserted. The projection 57b of the second plate 52 and the hole 55b of the first plate 51 correspond to the fixing parts of the present invention.

[0037] Furthermore, the second plate 52 is slightly curved toward the first plate 51. Therefore, when the first plate 51 and the second plate 52 are fixed together and the pulsation damper 40 is fixed to the fuel delivery pipe 35, the second plate 52 biases the pulsation damper 40 toward the fuel delivery pipe 35.

[0038] As described above, the fuel delivery pipe 35 that supplies fuel to the fuel injectors 30 in the throttle device 10 according to this embodiment is equipped with a pulsation damper 40. This absorbs pressure fluctuations of the fuel in the fuel delivery pipe 35, suppresses the influence on fuel injection in each fuel injector 30, and improves the accuracy of the fuel injection amount.

[0039] Since the pulsation damper 40 is positioned on the side of the fuel delivery pipe 35, a relatively large pulsation damper 40 can be positioned without protruding in the direction of extension of the fuel delivery pipe 35, compared to when it is provided at the end of the fuel delivery pipe 35.

[0040] The fuel delivery pipe 35 extends along a plurality of fuel injectors 30 that are spaced apart in the left-right direction, and the pulsation damper 40 is installed between adjacent fuel injectors 30. Therefore, the fuel supply device consisting of the fuel injectors 30, fuel delivery pipe 35, and pulsation damper 40 can be compactly arranged. Consequently, the throttle device 10, which includes the fuel injectors 30, fuel delivery pipe 35, and pulsation damper 40, can be configured compactly.

[0041] The pulsation damper 40 is fixed to the fuel delivery pipe 35 by a damper retaining plate 50. The damper retaining plate 50 wraps around the fuel delivery pipe 35 and the pulsation damper 40 attached to the fuel delivery pipe 35, pressing down on the fuel delivery pipe 35 and the pulsation damper 40, thereby fixing the fuel delivery pipe 35 and the pulsation damper 40 together. The damper retaining plate 50 has a snap-fit ​​type fixing part (hole 55b, projection 57b), and since the pulsation damper 40 is fixed to the fuel delivery pipe 35 by fixing with this fixing part, the fixing part can be made small.

[0042] Furthermore, the damper retaining plate 50 is composed of a U-shaped first plate 51 that extends laterally with respect to the extension direction of the fuel delivery pipe 35 and wraps around the fuel delivery pipe 35 and the pulsation damper 40, and a second plate 52 that supports the pulsation damper 40. This allows for a simpler configuration of the damper retaining plate 50.

[0043] In particular, the first plate 51 and the second plate 52 are fixed together by a snap-fit ​​type fixing structure in which the projection 57b of the second plate 52 is engaged with the hole 55b provided in the first plate 51, and the pulsation damper 40 can be fixed to the fuel delivery pipe 35, thus simplifying the fixing structure of the pulsation damper 40. In addition, the first plate 51 and the second plate 52 can be easily attached and detached, and the pulsation damper 40 can be easily replaced.

[0044] Furthermore, the fuel injector 30 is equipped with a connector 30b for connecting wiring for operation control. Therefore, by making the damper retaining plate 50 that fixes the pulsation damper 40 installed between adjacent fuel injectors 30 compact, it is possible to make it so as not to interfere with the attachment and detachment of the connector 30b, thereby improving the maintainability of the fuel injector 30.

[0045] Furthermore, the second plate 52 is made of an elastic material, and when the pulsation damper 40 is fixed to the fuel delivery pipe 35 by the first plate 51 and the second plate 52, it biases the pulsation damper 40 toward the fuel delivery pipe 35, thereby preventing the pulsation damper 40 from falling out.

[0046] This concludes the description of the embodiments, but the embodiments of the present invention are not limited to those described above. For example, in the above embodiment, the damper retaining plate 50 has a U-shaped first plate 51 supported by the fuel delivery pipe 35 and a second plate 52 that supports the pulsation damper 40, but the detailed shapes of the first plate 51 and the second plate 52 may be changed as appropriate.

[0047] Furthermore, although the present invention is applied to the fuel delivery pipe 35 that supplies fuel to two fuel injectors 30 in this embodiment, the present invention may also be applied to a fuel delivery pipe that supplies fuel to fuel injectors other than two.

[0048] Furthermore, in this embodiment, the throttle device 10 is equipped with a fuel injection valve 30, and the present invention is applied to the fuel delivery pipe 35 connected to this fuel injection valve 30. However, the present invention can also be applied to a fuel delivery pipe 35 installed in a location other than the throttle device 10.

[0049] Furthermore, the present invention can also be applied to throttle devices for engines used in vehicles other than motorcycles. [Explanation of Symbols]

[0050] 1 Engine 10 Throttle device 16a, 16b Throttle valve 30. Fuel Injector (Fuel Injection System) 49 Fuel supply path 35 Fuel delivery pipe 40 Pulsation Damper 50 Damper retaining plate (damper fixing device) 55b Hole (fixed part) 57b Projection (fixed part) 51. First plate (first fixing device) 52. Second plate (second fixing device)

Claims

1. A fuel delivery pipe extending in a predetermined direction and having a fuel supply passage inside, which supplies fuel to the engine's fuel injector, A pulsation damper is installed on the side of the fuel delivery pipe and absorbs fluctuations in the fuel pressure within the fuel supply passage. The system includes a damper fixing device that wraps around the fuel delivery pipe and the pulsation damper, pressing down on the fuel delivery pipe and the pulsation damper, and fixing the fuel delivery pipe and the pulsation damper together. The damper fixing device is, A U-shaped first fixing device is installed around the fuel delivery pipe in a lateral direction relative to its extension direction, It comprises a second fixing device that supports the pulsation damper, It has a snap-fit ​​fastening section, The fixing portion fixes the first fixing device and the second fixing device, so that the first fixing device and the second fixing device surround the fuel delivery pipe and the pulsation damper. The pulsation damper is biased toward the fuel delivery pipe by the fixing part, and the pulsation damper is detachably fixed to the fuel delivery pipe. A fuel supply device characterized by the following features.

2. The first fastener is made of an elastic material and is bent in the direction in which the pulsation damper is attached to the fuel delivery pipe. The fuel supply device according to feature 1.

3. The fuel delivery pipe extends along a plurality of fuel injectors that are arranged at intervals in the predetermined direction. The fuel supply device according to claim 1 or 2, characterized in that the pulsation damper is installed between adjacent fuel injection devices.

4. The fuel supply device according to claim 3, characterized in that the fuel injection device and the fuel delivery pipe are fixed to a throttle device that controls the intake amount of the engine.

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