JPH03117680A - Fuel feed device for two cycle engine - Google Patents

Abstract

PURPOSE:To compact and simplify constitution and to facilitate a work to mount and demount devices to from the engine side by a method wherein an assembly where an intake air pipe, an injection valve, and a fuel pump are assembled together integrally with each other is integrally attachable to and detachable from the engine side. CONSTITUTION:An assembly 60 comprising an intake air pipe 19, an injection valve 23, a fuel pump 24, a regulator 37, a throttle valve 48, and a support member 49 is mounted to the engine 10 side through engagement to integrally constitute the devices attachably and detachably. Thus, a pipe for intercoupling the devices is eliminated to simplify constitution. Besides, since the assembly 60 is integrally attachable to and detachable from the engine 10 side, when each constituting device is removed from the engine 10 side, the assembly 60 is first removed from the engine 10 side, and a work may be effected at other place where a work condition is convenient. During assembly, above procedures may be reversed, and a work to mount and demount the devices can be facilitated compared with a conventional work made on each device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel supply device for a two-stroke engine equipped with a fuel injection valve.

(Prior Art) For example, two-stroke engines are often used in motorcycles, and the fuel supply system for this type of engine includes an intake pipe connected to the intake boat 17, and fuel injected into the intake pipe B. There is a system that is equipped with an injector and a fuel pump that pressurizes and feeds fuel into the injector (for example, Japanese Patent Publication No. 63-40257).

(Problem to be Solved by the Invention) By the way, in the -2 conventional configuration (,j:, the intake pipe, injection valve, and fuel pump are located on the vehicle body), on the engine side supported by the 1 norm! 7.Since these 8 devices and the fuel supply system are not installed individually, firstly, the overall structure of these 8 devices and the fuel supply system is bulky7.Also, secondly, the fuel pump is connected to the injection valve. The configuration is also complicated, as additional piping is required. Furthermore, thirdly, when attempting to remove and install these from the engine side during maintenance and inspection of each of the above devices, it is necessary to perform this removal and removal work for each device, and moreover, it is necessary to perform work on the vehicle body where these are installed. Since the space is narrow, the above-mentioned attachment/detachment work is extremely complicated. (Objective of the Invention) This invention has the following features. This was done with attention to the circumstances described in J-J, and it was designed to make the fuel supply system compact and simple in its configuration, as well as to make it possible to attach and detach each device that makes up this fuel supply system from the engine side. The purpose is to make the work easier.

(Structure of the Invention) A feature of the present invention for achieving the above object is that an intake pipe, a fuel injection valve, and a fuel pump that supplies fuel to this injection valve are integrally assembled with each other. The main feature is that the assembly can be attached to and detached from the engine side as a whole.

(for production) The effect of the above configuration is as follows.

The intake pipe 19, the injection valve 23, and the fuel pump 24 are integrally assembled with each other. Therefore, the overall configuration of the fuel supply device 11 becomes more compact than in the past in which these components were installed separately.

Further, since the injection valve 23 and the fuel pump 24 are integrally assembled, there is no need for piping, which was conventionally necessary, to connect the two.

Moreover, since the assembly 60 including the intake pipe 19, the injection valve 23, and the fuel pump 24 can be integrally attached to and removed from the engine IO side, the intake pipe 19, the injection valve 23. When attempting to remove these from the engine 10 side, such as during maintenance and inspection of the fuel pump 24, first remove the assembly 60 from the engine IO side, and then remove the assembly 60 from the engine IO side. By the way, it is only necessary to disassemble the above assembly 60 into each device such as the intake pipe 19, and when assembling each of the above devices to the engine 10 side,
The procedure may be reversed to that described above.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, ■ is a motorcycle, and arrow Fr in the figure indicates the front thereof. A front fork 3 is supported at the front end of the body frame 2 of the motorcycle 1 so as to be freely steerable, a front wheel 4 is supported at the lower end of the front fork 3, and a handle 5 is attached to the upper end. On the other hand, a rear arm 6 is pivotally supported at the rear end of the vehicle body frame 2, and a rear wheel 7 is supported at the rear end of this rear arm 6. 8 is a buffer.

Further, an engine 10 is supported on the vehicle body frame 2, and a fuel supply device 11 and an air cleaner 12 are sequentially attached to an intake port loa of the engine IO. Further, a fuel tank 13 is provided to store fuel to be supplied to the fuel supply device 11, and this fuel tank 13
is supported by the vehicle body frame 2 above the engine IO. On the other hand, an exhaust pipe 14 is connected to the exhaust port of the engine 10 as described above.

When the engine IO operates, outside air is drawn into the engine 10 through the air cleaner 12 and the fuel supply device 11, and fuel in the fuel tank 13 is supplied to the intake air A passing through the fuel supply device 11. It has become so. The power of the engine IO is transmitted to the rear wheel 7 via a power transmission device 16 and chain winding means 17.

The fuel supply device ll will be explained in more detail with reference to FIGS. 1 and 3.

An intake pipe 19 is connected to the intake boat of the engine 10, and the intake pipe 19 is divided into a front pipe 20 and a rear pipe 21, which are detachably screwed to each other.

Further, an electromagnetic opening/closing type injection valve 23 that can inject the fuel F into the intake pipe 19 is provided.
is attached so as to be sandwiched between protrusions 20a and 21a formed on the lower surfaces of the front tube 20 and the rear tube 21. In other words, if the front tube 20 and the rear tube 21 are separated, , the injection valve 23 can be removed from the intake pipe 19. Further, the injection direction of the injection valve 23 is directed forward and in a direction intersecting the axis of the intake pipe 19 at an acute angle.

A fuel pump 24 is provided to pressurize and feed fuel F to the injection valve 23. This fuel pump 24 is a centrifugal pump, and has a casing 25 disposed in a space between the lower surface of the protrusion 20a of the front pipe 20 and the lower front surface of the protrusion 21a of the rear pipe 21, A rotor 26 is rotatably supported within the casing 25, and an electric motor 27 for rotationally driving the rotor 26 is contained therein.

A suction hole 30 for the fuel F is formed on one side of the casing 25, and the inside of the fuel tank 13 is connected to this suction hole 30 by a pipe 31. Further, a first discharge hole 32 is formed in the casing 25, and this first discharge hole 32 is connected to a passage 33 formed in the protrusion 21a of the rear tube 21.
This communicates with the injection valve 23, and the fuel F pressurized within the casing 25 is sent into the injection valve 23 through the passage 33.

Furthermore, the internal pressure of the crank chamber in the engine 10,
Electronic control means 35 is provided for controlling the injection valve 23 by inputting the rotation angle of the crankshaft. That is, this control means 35 opens the injection valve 23 at the optimum timing for the operating conditions, and injects the fuel F sent into the injection valve 23 from the fuel pump 24 toward the intake air A flowing in the intake pipe 19. The amount of fuel F to be injected is determined according to the amount of intake air A by opening the injection valve 23 for an optimal period depending on the amount of intake air A at that time. There is.

Further, a regulator 37 is provided to adjust the pressure of the fuel F sent from the fuel pump 24 to the injection valve 23 to a predetermined pressure. This regulator 37 is a cylindrical casing 3
8, and the inside of this casing 38 is an upper chamber 38a and a lower chamber 38b.
A diaphragm 39 is provided, and a spring 40 is provided to bias the diaphragm 39 upward. Furthermore, an inverted valve seat tube 41 is provided in the upper chamber 38a, and the lower end of the valve seat tube 41 is opened and closed by the diaphragm 39, which bends up and down.

Meanwhile, a second discharge hole 42 is formed in the casing 25 of the fuel pump 24, and this second discharge hole 42 is connected to the front pipe 20.
It communicates with the valve seat pipe 41 through a passage 43 formed in the valve seat pipe 41 . Further, the upper chamber 38a is connected to the fuel tank 13 by a return pipe 44. Furthermore, the lower chamber 38b and the inside of the intake pipe 19 are connected by a pressure pipe 45.

Therefore, the fuel F flowing from the fuel pump 24 to the injection valve 23
When the pressure increases to a certain extent, this pressure causes the fuel F in the valve seat pipe 41 to move against the spring 40 and push against the diaphragm 39.
Push down on the fuel pump 2 as shown by the arrow in Figure 3.
A portion of the fuel F from 4 passes through the return pipe 44 to the fuel tank 1.
Returned to 3. As a result, the fuel pump 24
The pressure of the fuel F fed into the injection valve 23 is kept below a predetermined pressure.

Also, when the negative pressure inside the intake pipe 19 becomes thick (this negative pressure becomes large), this negative pressure resists the spring 40 and pulls down the diaphragm 39, and in this case, as shown by the arrow in FIG. A portion of the fuel F from the fuel pump 24 flows into the return pipe 44.
As a result, the pressure of the fuel F sent from the fuel pump 24 to the injection valve 23 is kept below a predetermined pressure.

A throttle valve 48 is provided between the front pipe 20 and the rear pipe 21 so as to be slidable up and down to freely open and close the passage in the intake pipe 19, and this throttle valve 48 can be attached to and detached from the intake pipe 19. It is covered by an attached support member 49. Further, a pivot shaft 51 is rotatably supported on the support member 49, a pivot arm 52 is attached to the pivot shaft 51, and a pivot end of the pivot arm 52 is connected to the throttle valve 48. ing.

Further, a throttle wire 54 is connected to the pivot shaft 51 via a pulley 53.
4, the pulley 53
The opening degree of the throttle valve 48 can be adjusted through the rotary arm 52 and the rotary arm 52.

Also, a potentiometer 55 interlocked with the pivot shaft 51
The potentiometer 55 detects the opening degree of the throttle valve 48 and outputs this detection signal to the control means 35. And this signal is
It is used as a signal for determining the injection time of the fuel F of the injection valve 23 and the number of injections relative to the rotation speed of the engine 10.

A coupler 57 is attached to one side of the fuel pump 24, and each wiring 58 of the injection valve 23, electric motor 27, and potentiometer 55 is centrally connected to the coupler 57. In other words, this fuel supply device 11
It is sufficient to connect the external terminal to the coupler 57.

In addition, the intake pipe 19, the injection valve 23, the fuel pump 24,
An assembly 60 including the regulator 37, the throttle valve 48, and the support member 49 can be integrally attached to and detached from the engine 10 side by fitting.

Moreover, the assembly 60 is formed to have almost the same external shape as a carburetor that is conventionally attached to the engine IO of the motorcycle 1 and has a unique shape for motorcycles, and The above assembly 60 can be attached to the engine lO to which the above carburetor has been attached, without requiring a separate connecting tool.
can be installed. That is, the carburetor and assembly 60 are compatible with the engine IO and can be selectively installed.

According to the embodiment described above, the intake pipe 19, the injection valve 23, etc. are made into one assembly 60, and the overall configuration of the fuel supply device 11 is made compact.

Furthermore, since the injection valve 23, fuel pump 24, and regulator 37 are integrally assembled, there is no need for piping to connect them, which simplifies the configuration.

Moreover, since the assembly 60 can be attached and detached integrally to the engine 10 side, when removing each device that makes up this assembly 60 from the engine 10 side, first the assembly 6
0 from the engine 10 side, and then perform other work on it at another location with good working conditions.Conversely, when assembling each of the above devices on the engine 10 side, The procedure may be reversed to that described above, and therefore, this attachment/detachment work is easier than in the past, which is performed for each device.

Further, the work for associating external equipment with the assembly 60 only requires piping for the suction hole 30, piping for the return pipe 44, and connecting external terminals to the coupler 57, so the above work is extremely simple. It's easy to do.

Although the above is based on the illustrated example, the rotor 26 in the fuel pump 24 may be driven not by the electric motor 27 but by the crankshaft or camshaft of the engine 10 via a flexible wire or the like.

(Effects of the Invention) According to the present invention, the intake pipe, the injection valve, and the fuel pump are integrally assembled with each other, compared to the conventional case where these were installed separately.

The overall configuration of the fuel supply device becomes compact.

Further, since the injection valve and the fuel pump are integrally assembled, the structure of the fuel supply device is simplified, such as eliminating the need for piping, which was conventionally necessary to connect the two.

Furthermore, the assembly consisting of the intake pipe, injection valve, and fuel pump can be attached and removed from the engine side as a whole, so it can be removed from the engine side when performing maintenance and inspection of the intake pipe, injection valve, and fuel pump. When attempting to remove it, first remove the above assembly from the engine side, then
The above assembly may be disassembled into each piece of equipment, such as the intake pipe, in a place with good working conditions such as a large working space. Also,
When assembling each of the above-mentioned devices to the engine side, the procedure described above may be reversed. Therefore, the intake pipe, injection valve, and fuel pump can be easily attached and detached from the engine side.

(Margin below)

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Fig. 1 is a sectional view of the right side of the fuel supply system, Fig. 2 is an overall view of the left side of the motorcycle, and Fig. 3 is a cross-sectional view of the left side of the motorcycle. FIG. 10... Engine, lOa... Intake boat, 11... Fuel supply device, 19... Intake pipe, 23... Injection valve, 24...
・Fuel pump, 60... Assembly, F... Fuel. Funeral map

Claims (1)

[Claims] 1. A two-stroke engine that has an intake pipe connected to the intake port of the engine, an injection valve that can inject fuel into the intake pipe, and a fuel pump that pressurizes and feeds fuel into the injection valve. A fuel supply system for a two-stroke engine, in which the intake pipe, the injection valve, and the fuel pump are integrally assembled with each other, and the assembly can be integrally attached to and detached from the engine side.