JP4122636B2 - Multiple vaporizer acceleration / deceleration device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a multiple carburetor that adjusts and controls the concentration and amount of an air-fuel mixture supplied to an engine, and in particular, both acceleration failure when the throttle valve is suddenly opened and engine stall when the throttle valve is suddenly closed. The present invention relates to an acceleration / deceleration device for a multiple carburetor for preventing.
[0002]
[Prior art]
A conventional multiple vaporizer acceleration / deceleration device will be described with reference to FIG. C is a carburetor. The intake passage 2 passes through the inside of the carburetor body 1 and the intake passage is controlled to be opened and closed by a throttle valve 3. Reference numeral 4 denotes a floating chamber body disposed below the vaporizer body 1. The floating body 5 is formed by the vaporizer body and the floating chamber body 4, and the floating chamber 5 includes a floating body 6 and the like. A constant fuel liquid level XX is formed by the liquid level control mechanism. M is a main fuel system comprising a main fuel jet 7 and a main nozzle 8 having a bleed hole 8A. The fuel in the float chamber 5 is controlled by the main fuel jet 7 and passes through the main nozzle 8. Sucked into the venturi portion V provided in the intake passage 2. A is a main air system for supplying air to the main fuel system M, and is controlled by the main air jet 10 into the well chamber W formed by surrounding the outer periphery of the main nozzle 8 from the main air passage 9. Is supplied. That is, the air in the atmospheric chamber 11 of the carburetor body 1 is controlled by the main air jet 10, and this air is supplied into the well chamber W through the main air passage 9, and then the main nozzle from the bleed hole 8A. 8 is supplied. In the main nozzle 8, the main fuel controlled by the main fuel jet 7 and the main air are mixed, and this air-fuel mixture is sucked into the venturi portion V from the tip of the main nozzle 8. A plurality of carburetors C are arranged to form a multiple carburetor, and the throttle valves 3 of the respective carburetors are connected so as to be interlocked via throttle valve levers of the respective carburetors described later. In this example, three are arranged in the vertical direction. Reference numeral 12 denotes a rotatable throttle valve shaft that holds and holds the throttle valve 3 that opens and closes the intake passage 2. A throttle valve lever 13 is integrally attached to the throttle valve shaft 12. The throttle valve shaft 12 and the throttle valve lever 13 are provided in each carburetor. One end of a throttle valve return spring 14 is engaged with the throttle valve lever 13, and the throttle valve lever 13 is given a force in the closing direction of the throttle valve 3 by the spring force of the throttle valve return spring 14. The The closing direction of the throttle valve 3 is clockwise in the figure. Moreover, one end of the accelerator wire 15 is latched by the throttle valve lever 13 of a single vaporizer among the vaporizers which comprise a multiple vaporizer. Reference numeral 16 denotes a driven lever corresponding to the throttle valve lever 13 of the single vaporizer and rotatably disposed on the throttle valve shaft 12, and the end surface 16 A of the driven lever 16 is connected to the bent portion 13 A of the throttle valve lever 13. A driven spring 17 is disposed between the throttle valve lever 13 and the driven lever 16. The bent portion 13A of the throttle valve lever 13 is separated from the end surface 16A of the driven lever 16 when the throttle valve 3 rotates in the opening direction, and the bent portion 13A contacts the end surface 16A when the throttle valve 3 rotates in the closing direction. The driven spring 17 elastically biases the bent portion 13A toward the end face 16A. Therefore, when the throttle valve lever 13 rotates counterclockwise to open the throttle valve 3, the bent portion 13A also rotates counterclockwise simultaneously, and the driven spring 17 follows the rotation of the bent portion 13A. The driven lever also rotates counterclockwise. On the other hand, when the throttle valve lever 13 rotates clockwise to close the throttle valve 3 from the open state of the throttle valve 3, this rotational force is mechanically applied to the end face 16A of the driven lever 16 via the bent portion 13A. The follower lever 16 rotates clockwise. The movement of the throttle valve lever 13 in the single vaporizer is transmitted to the throttle valve levers of other vaporizers by a link (not shown), and the throttle valves 3 of all the vaporizers open and close synchronously. Reference numeral 18 denotes a pump device, which is divided into a pump chamber 20 and an air chamber 21 sealed by a partition body 19. The partition body 19 is a diaphragm, and the partition body 19 and the driven lever 16 are connected by a rod 22. Reference numeral 23 denotes a control pressure path, one end of which is connected to the pump chamber 20 of the pump device 18, and the other end is branched to be connected to the main air passage 9 of each carburetor C. In this example, the control pressure path 23 is branched into three. The branched control pressure passages 23 allow the air flow from the pump chamber 20 toward the main air passage 9 and block the air flow from the main air passage 9 toward the pump chamber 20. Are arranged respectively. Further, a leak passage 25 is branched from the control pressure passage 23 toward the atmosphere. The leak passage 25 blocks air flow from the leak passage 25 to the atmosphere and allows air flow from the atmosphere to the leak passage 25. A second control valve 26 that controls the amount of air that flows in the leak passage 25 is disposed.
[0003]
According to the conventional acceleration / deceleration device of the multiple carburetor, the throttle valve lever 13 is rotated counterclockwise when the throttle valve 3 is operated in the opening direction. At this time, the driven lever 16 is a spring of the driven spring 17. It follows the throttle valve lever 13 by force and rotates counterclockwise. When the follower lever 16 rotates counterclockwise, the rod 22 presses the partition body 19 of the pump device 18 to reduce the volume of the pump chamber 20 and increase the air pressure in the pump chamber 20. The increased air pressure in the pump chamber 20 acts on each control pressure passage 23, opens each first control valve 24 in each control pressure passage 23, and enters the well chamber W through the main air passage 9. Thus, the mixture concentration of each carburetor can be increased, and a favorable engine acceleration operation can be performed. In this state, the main air restricted by the main air jet 10 is continuously supplied into the well chamber W of each vaporizer, and the second control valve 26 blocks the leak passage 25 from the atmosphere.
[0004]
Next, when the throttle valve 3 is operated in the closing direction, the throttle valve lever 13 is rotated clockwise. At this time, the driven lever 16 has the bent portion 13A of the throttle valve lever 13 at the end surface 16A of the driven lever 16. By abutting, it follows the throttle valve lever 13 and tries to rotate clockwise. On the other hand, in a state where the throttle valve 3 is opened, the partition body 19 is in an obliquely upper right position in the drawing and the volume of the pump chamber 20 is reduced. When the throttle valve 3 is operated in the closing direction, the driven lever When 16 moves to follow the throttle valve lever 13 and rotate in the clockwise direction, the rotational speed of the driven lever 16 in the clockwise direction is slowly increased. That is, when the partition body 19 is moved to the left position from the state in which the partition body 19 is in the right position and the volume of the pump chamber 20 is decreased, the second control valve is moved. 26 opens the leak passage 25, and only the air restricted by the throttle valve 27 enters the pump chamber 20. According to this, the speed at which the partition 19 is displaced from the pump chamber 20 side to the atmosphere chamber 21 side. Is greatly limited and is performed slowly. This gradual displacement of the partition 19 is transmitted to the driven lever 16 via the rod 22 and slows the rotational speed of the driven lever 16 in the clockwise direction. The end surface 16A of the driven lever 16 is bent via the bent portion 13A. The throttle valve 3 is engaged with the throttle valve lever 13 so that the throttle valve 3 can be slowed in the closing direction. Accordingly, when the throttle valve 3 is operated in the closing direction, the throttle valve 3 can be gradually closed, and the occurrence of engine stall due to the sudden closing of the throttle valve 3 is suppressed.
[0005]
[Problems to be solved by the invention]
According to the conventional multiple carburetor acceleration / deceleration device, it is necessary to provide each carburetor body 1 with a main air passage 9A connected to the control pressure passage 23 and a main air passage 9B connected to the main air jet 10. . And it is necessary to arrange | position the 1st control valve 24 to each control pressure path 23, respectively. Therefore, the design freedom of the multiple vaporizer is hindered and it is not preferable in reducing the manufacturing cost.
[0006]
The present invention has been made in view of the above problems, and provides a multiple vaporizer acceleration / deceleration device that has a high degree of design freedom in the main air system of a multiple vaporizer and can reduce manufacturing costs. Main purpose.
[0007]
[Means for solving the problems]
In order to achieve the object, the acceleration / deceleration device for a carburetor according to the present invention reduces the volume of the pump chamber of the pump device in synchronization with the opening operation of the throttle valve, and a plurality of air pressures increased in the pump chamber. In the closing operation of the throttle valve, the volume of the pump chamber is gradually increased and returned, giving resistance to the return of the throttle valve of each vaporizer, In the accelerating / decelerating device of the multiple carburetor that slowly returns to the closing direction, the switching valve device includes a sealed valve chamber, an atmosphere opening path that opens to the valve chamber, and a plurality of air introduction paths that open to the valve chamber; A control pressure path that opens to the valve chamber via the valve seat hole, and a control valve that closes the atmosphere open path when the valve seat hole of the control pressure path is opened and holds the atmosphere open path open when the valve seat hole is closed Each air introduction path to each well chamber of a plurality of vaporizers, and control pressure Branches the leak passage toward the air from the control pressure passage with communicates a tract in the pump chamber of the pump device, wherein the leak passage sequentially toward the control pressure passage from the atmosphere side, and the diaphragm portion, the control pressure passage from the leak passage allows air flow toward the, the first characterized in that each of arranging the one-way control valve to prevent air flow toward the leak passage from the control pressure channel.
[0008]
Furthermore, in addition to the first feature, the present invention has a second feature that each air introduction path is connected to a main air passage of each carburetor through an air pipe made of a pipe material.
[0009]
[Action]
According to the first feature, during the acceleration operation when the throttle valve is opened, the increased air pressure in the pump chamber is supplied to the control pressure passage, the valve chamber, each air introduction passage, each air pipe, and each main air passage. Through each well chamber of the vaporizer body of each vaporizer. During the deceleration operation when the throttle valve is closed, only the air restricted by the throttle portion flows into the pump chamber, whereby the closing direction speed of each throttle valve can be suppressed slowly.
[0010]
Further, according to the second feature, the air from the main air passage toward the well chamber of each carburetor is affected by the intake pulsation in each air pipe, and changes the mixture concentration characteristic during the period from the intermediate rotation to the high rotation. It is also possible to change the mixture concentration characteristics of each vaporizer by changing the length of the air tube.
[0011]
【Example】
An embodiment of an acceleration / deceleration device for a multiple carburetor according to the present invention will be described below with reference to FIG. In addition, about the same structure part as FIG. 2, the description is abbreviate | omitted using the same code | symbol. A main air passage 30 is provided in the vaporizer body 1 of the single vaporizer C constituting the multiple vaporizer, one end of which is connected to the well chamber W, and the other end is provided with a joint 31 including the main air jet 10. Provided. Reference numeral 40 denotes a switching valve device comprising the following. A sealed valve chamber 42 is formed in the main body 41 and the following passages open in the valve chamber 42. Reference numeral 43 denotes an atmosphere opening path, and one end is open to the atmosphere . 44 is an air introduction path, and one end communicates with the main air passage 30 via an air pipe 45 made of a pipe material such as a rubber pipe. In this example, since the multiple vaporizers are formed by three single vaporizers, three air introduction paths 44 are prepared, and each air introduction path is connected to each vaporizer joint 31 via each air pipe 45. Connected to. Reference numeral 46 denotes a control pressure path, one end of which is communicated with the valve chamber 42 via the valve seat hole 47, and the other end of which is communicated with the pump chamber 20 of the pump device 18. 48 is a control valve that opens and closes a valve seat hole 47 from the control pressure path 46 to the valve chamber 42 and a valve seat hole 49 at the open end to the valve chamber 42 of the atmosphere opening path 43. It works. When the control valve 48 closes the valve seat hole 47, the control valve 48 opens the valve seat hole 49 . On the other hand, when the control valve 48 opens the valve seat hole 47, the control valve 48 closes the valve seat hole 49. In this example, the control valve 48 is composed of a small-diameter cylindrical first valve portion 48A and a large-diameter cylindrical second valve portion 48B above the first valve portion 48A. The first valve portion 48A is a valve seat hole. 47 is opened and closed, and the second valve portion 48B opens and closes the valve seat hole 49. Reference numeral 50 denotes a leak passage which branches off from the control pressure passage 46 and opens toward the atmosphere. A one-way control valve 51 and a throttle portion 52 are disposed in the leak passage 50. The one-way control valve 51 blocks the air flow from the control pressure path 46 to the atmosphere and allows the air flow from the atmosphere to the control pressure path 46. Further, the throttle unit 52 limits the amount of air flowing through the leak passage 50.
[0012]
Next, the operation will be described. First, when the opening degree of the throttle valve 3 is kept constant or when the change in the opening degree of the throttle valve 3 is slight, the illustrated control valve 48 is in the lower position, and The first valve portion 48A closes and holds the valve seat hole 47, while the second valve portion 48B opens and holds the valve seat hole 49. According to the above, the main air passage 30 of each carburetor main body 1 of each carburetor is connected to the main air jet via the atmosphere opening passage 43 -the valve chamber 42 -the air introduction passage 44 -the air pipe 45 -the joint 31. The air controlled by 10 is supplied, and this air is supplied into the well chamber W of each carburetor, mixed with fuel in the main nozzle 8 and sucked into the venturi section V. None of the air supply paths obstructs the air flow, and the same main air supply as in the prior art is supplied to each carburetor.
[0013]
Next, the acceleration operation in which the throttle valve 3 is rapidly opened will be described. As in the prior art, when the throttle valve lever 13 is suddenly rotated counterclockwise and the throttle valve 3 is suddenly opened, the driven lever 16 is also rotated in synchronism with this, and this rotation is effected via the rod 22 and the partition body 19. , The compartment 19 reduces the volume of the pump chamber 20 and increases the air pressure in the pump chamber 20. The increased air pressure flows in the control pressure path 46, and the control valve 48 that receives the increased pressure moves upward at a stroke and closes the valve seat hole 49 connected to the atmosphere opening path 43. At the same time, the valve seat hole 47 is opened. According to the above, the air pressure increased in the pump chamber 20 is introduced into the sealed valve chamber 42 through the valve seat hole 47, and this air pressure is supplied to each air introduction path 44, each air pipe 45, each joint. 31, and supplied to the well chamber W of each vaporizer through each main air passage 30. Therefore, the air pressure in each well chamber W increases, the amount of fuel sucked into the venturi portion V from each main nozzle 8 can be increased, and a favorable engine acceleration operation can be performed. When the pressurized air flows through the control pressure passage 46, the one-way control valve 51 prevents the air flow from the leak passage 50 to the atmosphere, so that the pressurized air pressure in the control pressure passage 46 can be weakened. Absent.
[0014]
Then, the air pressure increased in the control pressure passage 46 is weakened substantially in synchronization with the end of the acceleration operation of the engine (for example, due to the inflow of minute air from the valve seat hole 47 into the control pressure passage 46). Therefore, the control valve 48 returns to the original position again, closes the valve seat hole 47 and opens the valve seat hole 49, and introduces the atmosphere into the valve chamber 42 from the atmosphere opening path 43 again. Therefore, the subsequent engine operation is continued well.
[0015]
Next, a description will be given of a deceleration operation in which the throttle valve 3 is rapidly returned to a low opening from a state where the throttle valve 3 is opened to a high opening. When the throttle valve 3 is in the high opening state, the partition body 19 is pressed by the rod 22 as in the conventional case, and the chamber volume of the pump chamber 20 is reduced, that is, in the right position in the figure. When the throttle valve lever 13 is rotated clockwise from such a state, this rotational force is directly transmitted to the end surface 16A of the driven lever 16 through the bent portion 13A, and the driven lever 16 and the throttle valve lever 13 are moved. Try to rotate clockwise in a synchronous manner. Then, the clockwise rotational force of the driven lever 16 is transmitted to the partition body 19 via the rod 22, and the volume of the pump chamber 20 is increased by pulling the partition body 19 toward the atmosphere chamber 21 side. The pressure of is reduced. On the other hand, the valve seat hole 47 of the control pressure passage 46 communicated with the pump chamber 20 in this state is closed and held by the first valve portion 48A of the control valve 48, and the inside of the pump chamber 20 acting on the control pressure passage 46 The reduced pressure acts on the one-way control valve 51 in the leak passage 50 to open the hole, and the control pressure passage 46 is opened to the atmosphere through the leak passage 50. According to the above, the pressure reduced in the pump chamber 20 is released to the atmosphere while being restricted by the throttle portion 52 in the leak passage 50, and the pressure in the pump chamber 20 reduced over time is The pressure is gradually returned to the atmospheric pressure, and the reduced pressure in the pump chamber 20 gives a large resistance to the movement of the partition body 19 toward the atmosphere chamber 21 side. Accordingly, the clockwise rotation of the throttle valve lever 13 is subjected to resistance by the driven lever 16 communicated with the partition body 19 via the rod 22, and the clockwise rotation of the throttle valve lever is performed slowly. The throttle valve 3 of the container will also rotate slowly in the closing direction. Therefore, occurrence of engine stall due to sudden closing of the throttle valve 3 is suppressed.
[0016]
According to the present invention, when the throttle valve 3 is at a substantially constant opening, the control pressure path 46 and the valve chamber 42 are shut off, and the air release path 43 and the valve chamber 42 are directed toward the well W of each vaporizer. The main air is supplied through the air introduction passages 44, the air pipes 45, and the main air passages 30. When the throttle valve 3 is suddenly opened, the air release passage 43 and the valve chamber 42 are shut off, and the pump The pressurized air pressure in the chamber 20 was supplied into the well chamber W of each carburetor via the control pressure passage 46, the valve chamber 42, each air introduction passage 44, each air pipe 45, and each main air passage 30. Therefore, the main air passage 30 provided in the vaporizer main body 1 can be made single. This is preferable in that the design freedom of the vaporizer body can be greatly improved and the manufacturing cost thereof is reduced.
[0017]
Further, when each air introduction path 44 and the main air passage 30 of each carburetor main body 1 are connected with each air pipe 45 made of a pipe material such as a rubber pipe, the air-fuel mixture concentration particularly from the intermediate rotation region to the high rotation region of the engine. This is effective in changing (A / F). This is shown in the experimental results of FIG. In FIG. 3, the vertical axis indicates the air-fuel ratio (A / F), and the horizontal axis indicates the engine speed (rpm). The symbols in the figure are as follows. A square indicates a conventional vaporizer shown in FIG. The mark ● indicates the vaporizer of the present invention in which the length L of the air tube 21 is 10 mm. The symbol (2) indicates the vaporizer of the present invention in which the length L of the air tube 21 is 150 mm. The symbol ▲ indicates the vaporizer of the present invention in which the length L of the air tube 21 is 280 mm. A circle indicates a vaporizer of the present invention in which the length L of the air tube 21 is 430 mm. From the above experimental results, the following will be clarified. According to the conventional carburetor not provided with the air pipe 45, the air-fuel mixture concentration (A / F) shows a substantially constant 13 between the engine speed of 3500 rpm and 5500 rpm. According to this, it is difficult to change the mixture concentration (A / F) at the time of intermediate opening operation and the mixture concentration (A / F) at the time of high opening operation. In the case where the length L of the air pipe 45 is 10 mm, 150 mm, and 430 mm, the air-fuel mixture concentration (A / F) can be greatly increased especially at 4000 rpm and 4500 rpm of the engine. Further, the air pipe 45 has a length L of 280 mm, and the mixture concentration (A / F) can be increased at 4000 rpm of the engine. That is, according to the use of the air pipe 45 in the multiple vaporizer of the present invention, each main air passage 20 of each vaporizer is opened to the atmosphere via the air pipe 45 made of a pipe material. And changing the length L of the air tube. The air-fuel mixture concentration (A / F) can be increased in a specific engine speed range higher than the intermediate opening operation of the engine. And the concentration ratio of the air-fuel mixture concentration can be changed. There was found. This is considered to be caused by the fact that the pulsating pressure generated in the engine acts in the air pipe 45 through the intake passage 2 and affects the air flow passing through the main air jet 10.
[0018]
Moreover, the air introduction path 44 opened to the valve chamber 42 may be a single, the air introduction path 44 may be branched into three, and connected to the joint 31 of each vaporizer.
[0019]
【The invention's effect】
As described above, according to the accelerating / decelerating device for a multiple carburetor according to the present invention, the switching valve device 40 includes the sealed valve chamber 42, the atmosphere open passage 43 that opens to the valve chamber 42, and the valve chamber 42 that opens. A plurality of air introduction passages 44, a control pressure passage 46 that opens to the valve chamber 42 via the valve seat hole 47, and the air release passage 43 is closed when the valve seat hole 47 of the control pressure passage 46 is opened. And a control valve 48 for opening and holding the air release path 43 when the seat hole 47 is closed, the air introduction paths are connected to the well chambers W of the plurality of vaporizers, and the control pressure path 46 is connected to the pump device 18. A leak passage 50 that communicates with the pump chamber 20 and branches from the control pressure passage 23 to the atmosphere is branched, and the leak passage is sequentially controlled from the throttle portion 52 and the leak passage 50 from the atmosphere side toward the control pressure passage 23. Allow air flow to pressure path 23 Because a one-way control valve 51 that prevents air flow from the control pressure passage 23 toward the leak passage 50 respectively arranged, the main air passage of single to be formed in the carburetor body constituting the multiple-vaporizer Therefore, the design freedom of the vaporizer can be increased and the manufacturing cost can be reduced.
[0020]
Furthermore, according to the connection to the main air passage of each carburetor body through each air introduction path and an air pipe made of a pipe material, the mixture concentration in a specific engine speed range above the intermediate opening operating range of the engine. (A / F) can be increased, the density characteristics can be easily adjusted, setting workability can be improved, and development efficiency can be improved. Further, by changing the length of the air pipe, the concentration ratio of the air-fuel mixture concentration can be changed, and further improvement in setting workability can be achieved. The above is particularly effective when making a difference in the mixture concentration characteristics of the vaporizers constituting the multiple vaporizer.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of an acceleration / deceleration device for a multiple carburetor according to the present invention.
FIG. 2 is a longitudinal sectional view of a main part showing an acceleration / deceleration device for a conventional multiple carburetor.
FIG. 3 is a diagram showing the relationship between the mixture concentration (A / F) of the carburetor constituting the multiple carburetor of the present invention and the engine speed (Ne rpm).
[Explanation of symbols]
3 Throttle valve 18 Pump device 20 Pump chamber W Well chamber 40 Switching valve device 42 Valve chamber 43 Air release path 44 Air introduction path 45 Air pipe 46 Control pressure path 48 Control valve 50 Leak path 51 One-way control valve 52 Throttle part

Claims (2)

The volume of the pump chamber (20) of the pump device ( 18 ) is reduced in synchronism with the opening operation of the throttle valve (3) , and the air pressure boosted in the pump chamber (20) is changed to each vaporizer of the plurality of vaporizers. Supply into the well chamber (W ) of the main body (1) , and in the closing operation of the throttle valve ( 3 ) , the volume of the pump chamber (20) is gradually increased and returned, and the throttle valve (3) of each vaporizer is returned. In the accelerating / decelerating device of the multiple carburetor that slowly returns the throttle valve (3) in the closing direction, the switching valve device (40) includes a sealed valve chamber (42) and a valve chamber (42 the atmosphere open passage which is open (43) in), a plurality of air introducing passage that opens to the valve chamber (42) and (44), the control pressure passage which opens to the valve chamber via a valve seat hole (47) (42) ( 46 ) and when the valve seat hole ( 47 ) of the control pressure passage (46) is opened, the air release passage ( 43 ) is closed, and when the valve seat hole (47) is closed. And a control valve (48) for keeping the atmosphere open passage (43) open, and the air introduction passages (44) communicate with the well chambers (W) of the plurality of vaporizers, and the control pressure passage (46 ) the pump chamber of the pumping device (18) (control pressure passage with contact 20) (branching the leak passage (50) toward the atmosphere than 23), the control pressure passage from the atmosphere side to the leak passage (23) blocking sequentially toward a throttle portion (52), allowing the air to flow toward the control pressure passage (46) from the leak passage (50), the air flow towards the leak passage (50) from the control pressure passage (46) to An accelerating / decelerating device for a multiple carburetor, characterized in that a one-way control valve 51 is disposed. The acceleration / deceleration device for a multiple carburetor according to claim 1, wherein each of the air introduction paths (44) is connected to a main air passage (30) of each carburetor via an air pipe (45) made of a pipe material.

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