JPH01280669A - Control device for carburetor - Google Patents

Abstract

PURPOSE:To increase an amount of fuel to a main nozzle on the primary side during the starting and to improve startability, by a method wherein based on the number of revolutions of an engine during the starting and an engine running starting time after the starting, an electromagnetic mechanism to regulate a pressure in the suction pipe of the fuel increase system of a carburetor on the primary side is controlled. CONSTITUTION:During the starting of an internal combustion engine, the number of revolutions of an engine is detected by a sensor 112 along with turning ON of an ignition switch 114, and an engine running starting time is decided by a timer 110. Based on outputs from the sensor 112 and the timer 110, a valve body 106 of an electromagnetic mechanism 102 is reciprocated by means of a control part 108. A power pressure passage 76 is opened and closed, and a pressure in a suction pipe exerted on a power pressure chamber 74 is regulated. Namely, through the energizing force of a power jet control spring 80, a valve rod 90 is depressed through a piston rod 82, and a power valve body 98 is separated away from a valve seat 100 to open a power fuel hole 88. This constitution causes increase of an amount of fuel to a main nozzle on the primary side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a carburetor control device, and more particularly to a carburetor control device that can improve the startability of an internal combustion engine.

[Background Art] An internal combustion engine is provided with a carburetor that appropriately generates a mixture of fuel and air depending on the operating state of the engine.

The carburetor includes a series type carburetor equipped with a - throttle valve, and a double series type carburetor in which a primary side vaporizer with a primary side throttle valve and a secondary side carburetor with a secondary side throttle valve are installed side by side. There are utensils etc.

As a control device for such a vaporizer, for example, Japanese Patent Application Laid-open No. 6
It is disclosed in Japanese Patent Application Laid-open No. 1-58959 and Japanese Patent Application Laid-Open No. 178758-1982. The device described in Japanese Patent Application Laid-Open No. 61-58959 increases the diameter of the jet controlled by a duty solenoid, detects suction negative pressure, supplies air, and supplies more air when the piston is fully detonated. This improves drivability at low temperatures. Furthermore, the device described in Japanese Patent Application Laid-open No. 62-178758 controls the opening duty ratio of a fuel increase solenoid valve at the time of starting an internal combustion engine according to the cooling water temperature and the opening degree of the throttle valve. Even if cranking operation is performed at the opening, an appropriate starting air-fuel ratio can be obtained.

Further, as a structure of the power valve of the fuel increase system provided in the dual carburetor, there is one shown in FIG. That is, a power pressure chamber 74 is formed in the upper wall portion 72 of the primary float chamber 40, and a power pressure passage 76 for introducing intake pipe pressure is communicated with the power pressure chamber 74. In the power pressure chamber 74, a piston 78 is controlled by a power pump.
It is supported by a spring 80. One end 82a of a piston rod 82 is connected to the piston 78. Further, a holding body 8 is provided on the lower wall portion 84 of the primary side float chamber 40.
Install 6. A power fuel hole 88 is formed in the holder 86, and a reciprocating valve rod 90 is loosely fitted into the power fuel hole 88.

One end 90a of the valve rod 90 is fixed to the support plate 94, protruding slightly from the support plate 94 fixed to the tip of a holding spring 92 installed on the upper surface of the holding body 86. Further, a valve chamber 96 is formed in the holding body 86, and a power valve body 98 fixed to the other end of the valve rod 90 is located in this valve chamber 9G. This power valve body 98 is for opening and closing the power fuel hole 88 by coming into contact with and separating from the valve seat 100.

On the other hand, the valve rod 90 is pressed so that the end surface of the other end 82b of the piston mouth/nod 82 comes into contact with one end 90a. As a result, the power valve 46 reciprocates the piston rod 82 by the intake pipe negative pressure, which is the intake pipe pressure acting on the power pressure chamber 74, and moves the power valve body 98 toward and away from the valve seat 100 to open the power fuel hole 88. By moving it to open and close, the supply of fuel to the power fuel path 48 is adjusted.

That is, in the power valve shown in FIG. 5, fuel equivalent to the power jet flow rate is increased to the primary side main nozzle side in a predetermined intake pipe pressure range by the set pressure of the power jet control spring 80.

[Problems to be Solved by the Invention] However, in conventional carburetor operation control, fuel increase/decrease is controlled by the set pressure of the power jet control spring under all temperature conditions such as cooling water temperature. In an internal combustion engine using an air-fuel ratio on the lean side, the air-fuel ratio at the time of starting also shifts to the lean side, resulting in a disadvantage that the startability deteriorates.

[Object of the invention] Therefore, the object of this invention is to eliminate the above-mentioned disadvantages.
By controlling the operation of the electromagnetic mechanism based on signals from the rotation sensor and the delay timer mechanism, even if the mixture ratio is set to the lean side, the mixture ratio can be set to the rich side when starting the internal combustion engine. The object of the present invention is to realize a carburetor control device that can improve startability.

[Means for solving the problem] In order to achieve this object, the present invention provides a carburetor control system that controls the operation of a dual carburetor having a primary side carburetor and a secondary side carburetor based on intake pipe pressure. In the device, a rotation sensor is provided to detect the rotation speed at the time of starting the internal combustion engine, a delay timer mechanism is provided to determine the operation start time after the internal combustion engine is started, and the power increaser of the fuel increasing system provided in the primary side carburetor is provided. An electromagnetic mechanism is provided to adjust the intake pipe pressure that operates the valve, and the electromagnetic mechanism is operated and controlled to increase fuel based on the signal state from the rotation sensor and the delay timer mechanism at the time of the 17JIJ start operation. It is characterized by the provision of a control section to

[Operation] According to the configuration of the present invention, the engine rotation speed at the time of starting the internal combustion engine is detected by the rotation sensor, and the operating time at the time of starting is determined by the delay timer mechanism, and the electromagnetic mechanism is operated. By operating the mechanism, it is possible to adjust the intake pipe pressure that operates the power valve, increasing fuel at the time of starting, and improving starting performance.

[Examples] Examples of the present invention will be described below in detail and specifically based on the drawings.

1 to 4 show embodiments of this invention. In the figure, 2 is an internal combustion engine, 4 is an air cleaner, 6 is a dual carburetor (hereinafter simply referred to as "carburetor"), 8 is an intake manifold, 10 is an intake passage, 12 is an exhaust manifold, 14
is the exhaust passage.

The intake passage 10 communicates with an intake port 16 of the internal combustion engine 2. This intake port 16 communicates with a combustion chamber 20 via an intake valve 18, and this combustion chamber 20 communicates with an exhaust passage 14 via an exhaust valve 22. Also, this υ1−
The air passage 14 communicates with the inside of the exhaust pipe 24.

The carburetor 6 consists of a primary side carburetor 6A in a low speed operating range and a secondary side carburetor 6B in a high speed operating range, and only the primary side carburetor 6A is operated during low speed operation to increase the engine speed. As the rotation speed increases, the secondary side carburetor 6B starts to operate, and at high speed rotation, both of them are operated, and the structure is as follows. That is, as shown in FIG. 2, the carburetor 6 includes a primary throttle valve 28 disposed within the primary intake passage 26 on the primary carburetor 6A side, and a secondary throttle valve 28 disposed within the primary intake passage 26 on the secondary carburetor 6B side. The secondary throttle valve 32 is disposed within the intake passage 30. In addition, a primary side main nozzle 34 is provided in the primary side intake passage 28.
is provided facing the primary side main nozzle 34, and one end side of a primary side fuel passage 36 communicates with this primary side main nozzle 34. The other end side of this primary fuel passage 36 communicates with a primary float chamber 40 via a primary main jet 38 . A primary side float 42 is provided in this primary side flow 1-chamber 40, and a needle valve 44 is installed on this primary side float 42. A power fuel passage 48 communicating with a power valve 46 constituting a fuel increase system is communicated midway through the primary fuel passage 34 . Further, a power jet 50 is interposed in the middle of this power fuel path 48. The power valve 46 is operated by intake pipe negative pressure, which is intake pipe pressure.

Further, a secondary side main nozzle 52 is provided in the secondary side intake passage 30.
is provided facing the secondary side main nozzle 52, and one end side of a secondary side fuel passage 54 communicates with this secondary side main nozzle 52. The other end of the secondary fuel passage 54 communicates with a secondary float chamber 58 via a secondary main jet 56 . Further, a secondary main air bleed tube 60 is interposed in the middle of the secondary fuel passage 54 . Further, the secondary float chamber 58 is provided with a secondary float 62 .

In addition, in the secondary side carburetor 6B, the pump arm 64
A pump plunger 66 is provided which is actuated by the
Additionally, a HIC valve 68 is provided.

An actuator 70 that operates the secondary throttle valve 32 using intake pipe negative pressure is connected to the secondary throttle valve 32 .

On the other hand, the power valve 46 is constructed as shown in FIG. That is, the earthen wall portion 72 of the primary float chamber 40
A power pressure chamber 74 is formed in the engine, and a power pressure passage 76 for introducing intake pipe pressure is communicated with the power pressure chamber 74. A piston 78 is supported within the power pressure chamber 76 by a power jet control spring 80. The piston 78 includes one end 82 of a piston rod 82.
Connect a. In addition, the lower wall portion 8 of the primary side float chamber 40
4, a holding body 86 is installed. A power fuel hole 88 is formed in this holding body 86, and this power fuel hole 88 is
A reciprocating valve rod 90 is loosely fitted within the valve 8. One end 90a of this valve rod 90 is fixed to the support plate 94, protruding slightly from the support plate 94 fixed to the tip of a holding spring 92 installed on the upper surface of the holding body 86. Further, a valve chamber 96 is formed in the holding body 86, and a power valve body 98 fixed to the other end of the valve rod 90 is located in this valve chamber 96. This power valve body 98 is for opening and closing the power fuel hole 88 by coming into contact with and separating from the valve seat 100.

On the other hand, the valve rod 90 is pressed so that the end surface of the other end 82b of the piston rod 82 comes into contact with one end 90a. As a result, the power valve 46 reciprocates the piston rod 82 by the intake pipe negative pressure acting on the power pressure chamber 74 and the power jet control spring 80, and moves the power valve body 98 toward and away from the valve seat 100, thereby discharging the power fuel. By moving the hole 88 to open or close, the supply of fuel to the power fuel path 48 is adjusted.

Further, as shown in FIG. 3, an electromagnetic mechanism 102 for adjusting the intake pipe negative pressure acting on the power pressure chamber 74 is provided in the middle of the power pressure passage 76 that guides the intake pipe negative pressure. This electromagnetic mechanism 102 includes an electromagnetic coil 104 and a valve body 106, and its operation is controlled by a control section 108.

This control unit 108 is in communication with a power supply 116 via a delay timer 110 that is a delay timer mechanism, a rotation sensor 112, and an ignition switch 114.

The delay timer 110 determines the operation start time after the internal combustion engine 2 is started.

Further, the rotation sensor 112 determines whether the internal combustion engine 2 is started, that is, detects the engine rotation speed at the time of startup, and determines the setting range.

The control unit 108 controls the operation of the electromagnetic mechanism 102 based on signals from the rotation sensor 112 and the delay timer 110, that is, moves the valve body 106 forward and backward to adjust the negative pressure in the intake pipe to the power pressure chamber 74. It is.

Further, the control unit 106 is connected to the rotation sensor 112 on the input side and a starter signal generation unit 118 that outputs a signal only when the starter switch (not shown) is turned on, and the electromagnetic mechanism 102 on the output side. is in contact.

Next, the operation of this embodiment will be explained.

When starting the internal combustion engine 2, the ignition switch 11
4 is turned on, the rotation sensor 112 detects the engine rotation speed at the time of startup, and the delay timer 110 determines the operation start time after the internal combustion engine 2 is started. Signals from the rotation sensor 112 and the delay timer 110 are input to the control unit 108, and signals from the scooter signal generation unit 118 are input to the control unit 108 only when the starter switch is turned on.
08 is input.

The control unit 108 reciprocates the valve body 106 of the electromagnetic mechanism 102 based on the signals from the rotation sensor 112 and the delay timer 110, thereby causing the power pressure passage 76 to
is opened and closed to adjust the intake pipe pressure acting on the power pressure chamber 74. In other words, even if the biasing force of the power jet control spring 80 is constant, the power valve 46 can be operated by adjusting the intake pipe negative pressure acting on the power pressure chamber 74. As a result, when starting the internal combustion engine 2, the valve body 106 of the electromagnetic mechanism 102 is moved to close the power pressure passage 76, thereby weakening the intake pipe negative pressure that is the intake pipe pressure acting on the pub pressure chamber 74. , the piston rod 82 is pushed down by the biasing force of the power jet control spring 80, and the valve rod 90 is pushed down and moved by the other end 82b of the piston rod 82, thereby separating the power valve body 98 from the valve seat 100 and opening the power fuel hole. 88 is opened to increase the fuel to the primary side main nozzle 34, and as a result, even in an internal combustion engine using a leaner mixture ratio, fuel is increased at the time of startup to set the mixture ratio to the richer side. This makes it possible to improve startability.

[Effects of the Invention] As is clear from the detailed explanation above, according to the present invention,
By controlling the operation of the electromagnetic mechanism using signals from the rotation sensor and the delay timer mechanism, it is possible to adjust the intake pipe pressure that operates the power valve to increase the amount of fuel at the time of starting, thereby improving starting performance.

[Brief explanation of the drawing]

1 to 4 show embodiments of the present invention, FIG. 1 is a schematic diagram of an internal combustion engine equipped with a carburetor, FIG. 2 is an enlarged sectional view of a flower vase, and FIG. 3 is an explanatory diagram of a power valve. FIG. 4 is a block diagram of the control system. FIG. 5 is an explanatory diagram of a conventional power valve. In the figure, 2 is an internal combustion engine, 6 is a carburetor, 26 is a primary side intake passage, 2B is a primary side throttle valve, 30 is a secondary side intake passage, 3
2 is a secondary side throttle valve, 36 is a primary side fuel path, 46 is a power valve, 50 is a power jet, 54 is a secondary side fuel path,
74 is a power pressure chamber, 76 is a power pressure passage, 80 is a power jet control spring, 82 is a piston rod, 88 is a power fuel hole, 98 is a power valve body, 100 is a valve seat, 10
2 is an electromagnetic mechanism, 106 is a valve body, 108 is a control unit, 11
0 is a delay timer, 112 is a rotation sensor, and 11
8 is a starter signal generating section.

Claims (1)

[Claims] 1. In a carburetor control device that controls the operation of a dual carburetor having a primary side carburetor and a secondary side carburetor by intake pipe pressure, a rotation sensor is provided to detect the rotation speed at the time of starting the internal combustion engine, A delay timer mechanism is provided for determining an operation start time after the internal combustion engine is started, and an electromagnetic mechanism is provided for adjusting the intake pipe pressure for operating a fuel increase system power valve provided in the primary side carburetor, and the internal combustion engine is started. A carburetor control device comprising: a control unit configured to control the operation of the electromagnetic mechanism to increase the amount of fuel based on signal states from the rotation sensor and the delay timer mechanism.