JPS6046253B2 - Throttle opener device for multiple carburetor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention automatically opens a throttle valve to a predetermined opening slightly larger than the idling opening when a multi-cylinder internal combustion engine in a vehicle such as an automobile or a motorcycle is operated at deceleration. The present invention relates to a throttle opener device for a multiple carburetor, which controls the air-fuel mixture filling efficiency of a multiple carburetor.

Generally, when an internal combustion engine suddenly decelerates, that is, when the throttle valve is suddenly closed to the idle opening while operating at high speed, the engine misfires due to an extremely low air-fuel mixture filling efficiency, and the amount of unburned components such as HC in the exhaust gas increases. increases.

To prevent this, in conventional multiple carburetors, all throttle valves are opened to the same specified opening in response to engine boost negative pressure that exceeds a certain value on the valve shaft that connects all throttle valves. A throttle opener is connected to prevent the filling efficiency of the air-fuel mixture from dropping below the ignition limit value during engine deceleration operation, but such a system reduces the engine braking effect and impairs operating performance to some extent. There are drawbacks to it.

The present invention was proposed in view of the above-mentioned problems, and the present invention divides multiple carburetors into at least two or two sets, and examines the characteristics of the throttle opener connected to the throttle valve of each carburetor, especially the operating negative pressure value and the operating It is an object of the present invention to provide the device in which the engine braking effect during deceleration operation of the engine is improved by making the amounts different from each other.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. The illustrated example shows a two-speed carburetor which is one form of a multiple carburetor, and it includes a first carburetor Cl on the left side and a second carburetor Co on the right side. It's getting more familiar.

The intake passages 2, , 22 formed in the main body 1, , 10 of each vaporized BiC, , C2 are provided with throttle valves 3, , 32, which are connected to the valve shafts 4, , 4, arranged coaxially, respectively. The valve stems 4, 42 are fixed and separate from each other and are supported on the corresponding carburetor body 1, 12 so as to be able to rotate independently.

A main throttle lever 5 is fixed to the valve shaft 41 of the first carburetor Cl, and valve opening and closing wires 6 and 7 which are alternately pulled by a throttle grip (not shown) are connected to this. The throttle valve 3 can be opened by pulling the valve closing wire 7, and it can be closed by pulling the valve closing wire 7. The main throttle lever 5 also has a throttle valve 31.
A valve closing spring 8 is connected which biases the valve in the closing direction. Further, the main throttle lever 5 has two projecting arms 5a and 5b,
An idle stopper screw 9 screwed onto the carburetor main body 1 is provided opposite to one of the projecting arms 5a.
determines the idle opening degree of the throttle valve 31 by supporting the protruding arm 5a. The other protruding arm 5b is connected to an operating rod 12 of a first throttle opener T1 via a seesaw lever 10 and a bell crank lever 11. The first throttle opener T1 has a diaphragm 13 connected to the operating rod 12, and a negative pressure chamber 14 defined by the diaphragm 13. 2 An intake path 2 downstream of the throttle valve 32 of the carburetor C2. When the diaphragm 13 responds to the boost negative pressure of the engine introduced into the negative pressure chamber 14 through the negative pressure passage 16, the throttle valve 31 is idled. It is designed to open to a specified opening degree that is slightly larger than the opening degree. This diaphragm 1
A spring 17 that determines the value of the operating negative pressure of No. 3 is compressed in the negative pressure chamber 14, and a stopper screw 18 that determines the specified opening degree of the throttle valve 31 is provided facing the diaphragm 13. On the other hand, a sub-throttle lever 19 and an intermediate lever 20 are fixedly installed at the tip and middle of the valve shaft 42 of the second carburetor C2, respectively. A valve closing spring 28 biased in the closing direction is connected,
Furthermore, the second throttle opener T is connected via the interlocking lever 21.
Two operating rods 22 are connected.

The second throttle opener T2 has a diaphragm 23 connected to the operating rod 22, and a negative pressure chamber 24 defined by the diaphragm 23, and the negative pressure chamber 24 is parallel to the negative pressure chamber 14 of the first throttle opener T1. The negative pressure passage 1
6, and when the diaphragm 23 responds to the boost negative pressure of the engine introduced into the negative pressure chamber 24 through the negative pressure passage 16, the throttle valve 32 is opened to a value greater than the idle opening. It is designed to open to the specified opening degree. A spring 25 that determines the operating negative pressure of the diaphragm 23 is compressed in the negative pressure chamber 24, and a stopper screw 26 that determines the specified opening degree of the throttle valve 32 is provided opposite the diaphragm 23. In this case, the operating negative pressure of the second throttle opener T2 is set higher than that of the first throttle opener T1, and at the same time, the opening degree of the throttle valve 32 by the second throttle opener T2 is equal to the opening degree of the throttle valve 31 by the first throttle opener T1. is set larger.

The main and sub throttle levers 5 and 19 are connected to each other via a tuning mechanism 27. The tuning mechanism 27 is constructed by screwing a tuning screw 29, which is connected to the projecting arm 5a of the main throttle lever 5 with a certain play 1, into the sub throttle lever 19. 2 throttle opener T
2, and therefore both valve shafts 41, 4 by an angle corresponding to the opening degree. can perform relative rotation. The engagement position of the tuning screw 29 with respect to the sub-throttle lever 19 is adjusted to adjust the gap between the protruding arm 5a and the sub-throttle lever 19, and thereby the throttle valves 31 and 32 of both carburetors Cl and C2 are adjusted. Idle opening can be synchronized. Therefore, normally, when the main throttle lever 5 is operated, the throttle valve 32 is controlled via the tuning mechanism 27.
The valve 32 can also be opened, and the valve 32 is mainly closed by the valve closing spring 28.
depends on the torsional torque. In addition, 30 in FIG. 3 is a lock nut of the tuning screw 29. A three-way solenoid valve 31 is interposed in the negative pressure passage 16, and a ventilation passage 32 having an air opening with an air cleaner 32a is inserted through the solenoid valve 31.
is connected.

The valve member 33 of the electromagnetic valve 31 has a first position where the ventilation passage 32 is shut off and the negative pressure passage 16 is made conductive, and a first position where the upstream side of the negative pressure passage 16 (negative pressure outlet hole 15 side) is shut off and the same downstream side is closed off. It can be operated between a second position and a second position in which the side is communicated with the air passage 32, and the first position is operated by the biasing force of the valve spring 34, and the second position is operated by the biasing force of the solenoid 35. Each will be done. A main switch 37 and a vehicle speed detection switch 38 are inserted in series in the circuit that connects the solenoid 35 to the power supply 36, and the vehicle speed detection switch 38 operates at a constant vehicle speed (for example, 17
．． 5h/h) or less. Next, to explain the operation of this embodiment, when the vehicle is traveling at a high speed where the vehicle speed detection switch 38 is open,
The main throttle lever 5 is connected to the throttle valves 31,3.

When the engine rotates in the closing direction, the boost negative pressure of the engine that increases accordingly is detected from the negative pressure outlet hole 15, and the negative pressure passage 1
6 through each negative pressure chamber 1 of both throttle openers Tl, T2.
4,24. Therefore, as mentioned above, the operating negative pressure of the second throttle opener T2 is equal to the operating negative pressure of the first throttle opener T.
Since the boost negative pressure of the engine is higher than the operating negative pressure of the second throttle opener T2, both throttle openers Tl and T2 operate simultaneously to open the corresponding throttle valves 31 and 3. Open to each specified opening. Thereafter, if the boost negative pressure of the engine falls below the operating negative pressure of the second throttle opener T2 (however, it is still higher than the operating negative pressure of the first throttle opener T1).

), the second throttle opener T2 returns to the inoperative state, so the throttle valve 32 of the second carburetor C2 moves in the closing direction by the action of the valve closing spring 28. However, since the first throttle opener T1 is still in operation, the second carburetor C
The closing of the second throttle valve 32 is stopped at the opening maintained by the first throttle opener T1 via the tuning mechanism 27, and as a result, both throttle valves 31 and 32 have the same opening. When the vehicle decelerates and the vehicle speed falls below the specified value (17.5-/h), the vehicle speed detection switch 38 senses this and closes (main switch 3
7 is, of course, already closed.

), the solenoid 35 of the electromagnetic valve 31 is energized, so that the valve member 33 moves to the second position and opens both throttle openers T.
The negative pressure chambers 14 and 24 of T2 and T2 are opened to the atmosphere opening 32a. In this way, the first throttle opener T1 also returns to the inoperative state, and both throttle valves 31 and 32 can be closed to the idle opening degree. FIG. 4 is a diagram showing the relationship between the boost negative pressure of the engine and the opening degrees of the throttle valves 31 and 32 controlled by the throttle openers Tl and T2 during the above operation, where line A is the first
Line B shows the opening degree changes of the throttle valve 31 of the carburetor C1, line B shows the throttle valve 32 of the second carburetor C2, and line C shows the opening changes of the throttle valve of the conventional carburetor, and θo represents each throttle valve 31, 3.

, θ1 is the opening degree of the throttle valve 31 by the first throttle opener T1, and 02 is the idle opening degree of the second throttle opener T.
2 and θc respectively indicate the opening degree of the throttle valve 32 by a conventional throttle opener. Also the fifth
The figure shows the boost negative pressure during engine deceleration and the unburned components in the exhaust gas (
In the present invention, the opening degree 02 of the throttle valve 32 by the second throttle opener T2 is determined from the opening degree θ1 of the throttle valve 31 by the first throttle opener T1.
is increased, so when both throttle openers Tl and T2 are activated, the boost negative pressure P1 of the cylinder on the second carburetor C2 side is increased.
is low, and the amount of unburned components E1 in the exhaust gas of that cylinder is relatively small, but the boost negative pressure P3 of the cylinder on the first carburetor C1 side is
is high, the amount of unburned components E3 in the exhaust gas of that cylinder is relatively large, and the total amount of unburned components for the two cylinders is eventually E1+E3.

On the other hand, in the conventional case where one throttle opener opens both throttle valves to the same opening degree θc, the opening degree 0c is
Since it is set to an intermediate value between 1 and 02, the amount of unburned components E2 for one cylinder also shows the intermediate value between E1 and E3, and therefore the total amount of unburned components for two cylinders is twice E2. becomes.

This value is approximately equal to E1+E3 in the case of the present invention. Also,
Even if the second throttle opener T2 is inactive, the throttle valve 32 is kept open at the specified opening degree 01 by the first throttle opener T1, similar to the throttle valve 31, so that the second gasification RI
The boost negative pressure of the cylinder on the c2 side is prevented from increasing excessively, and the unburned components discharged from that cylinder do not particularly increase.

By the way, in the conventional system in which one throttle opener opens both throttle valves to the same opening degree θc, the operating negative pressure Pc of the opener is equal to the operating negative pressure Pa of the first throttle opener T1 and the operating negative pressure Pb of the second throttle opener T2. Since the boost negative pressure during engine deceleration drops below the opener activation negative Fc, both throttle valves are held at the same opening degree θc from beginning to end by one throttle opener, and the overall Engine braking effect remains unchanged.

In contrast, in the present invention, the boost negative pressure during engine deceleration drops below the operating negative pressure Pb of the second throttle opener T2 (however, it is still higher than the operating negative pressure AC of the conventional throttle opener).
Immediately, the second throttle opener T2 returns to the inoperative state and moves the throttle valve 32 of the second carburetor C2, which had been kept at a high opening, to the closing direction, thereby causing the throttle to close. Due to the high opening of valve 32, it was not fully utilized.
The engine braking effect of the cylinder on the second carburetor C2 side increases rapidly, and the overall engine braking effect is greatly enhanced. Therefore, in the operating range where the boost negative pressure is between the operating negative pressure Ab of the second throttle opener T2 and the operating negative Fc of the conventional throttle opener, the engine braking effect according to the present invention is significantly more effective than that of the conventional throttle opener. It is clear that it will get bigger. In addition, the boost negative pressure is lower than the operating pressure C of the conventional throttle opener, and
In the operating range higher than the operating negative pressure Pa of the throttle opener T1, comparing the conventional one and the present invention, in the former, both throttle valves are closed and the engine braking effect rapidly increases, while in the latter, the engine braking effect increases rapidly. 1 Throttle opener T1 is in operation from start to finish and keeps open the throttle valve 31 of the first carburetor C1, but since its opening is relatively small, the cylinder on the side of the first carburetor C1 also exerts a relatively large engine brake. The effect continues and the overall engine braking effect is therefore only slightly greater in the conventional case than in the present invention.

Comparing the engine braking effect of the present invention with that of the conventional engine braking effect as described above, it is found that the former is significantly stronger than the latter, and the boost negative pressure is smaller than the operating negative PEPc of the conventional throttle opener and larger than the operating negative pressure Pa of the first throttle opener T1 (
In this operating range (the engine speed is lower than the above operating range), the latter is only slightly increased compared to the former, so generally speaking, the closer the vehicle is to the initial stage of deceleration, the more (
Even taking into account the fact that engine braking is more effective (the higher the engine speed during deceleration), the engine braking effect of the former, that is, the engine braking effect of the present invention, is significantly greater than the latter, that is, the engine braking effect of the conventional one. It is clear that this will be improved.

In addition, in the present invention, since the closing operations of both throttle valves are performed at different times, there is no worry that the amount of unburned components discharged from each cylinder will be concentrated at one time, and the catalytic converter, etc. The load on the exhaust gas purification device can be reduced.

As described above, according to the multiple carburetor of the present invention, the amount of unburned components in the exhaust gas of the engine can be maintained at the same level as that of conventional ones or lower than that of conventional ones, and the engine braking effect during engine deceleration operation can be achieved. This can significantly improve the driving performance of the vehicle.

[Brief explanation of drawings]

Fig. 1 is a plan view of a dual carburetor embodying the present invention, Figs. 2 and 3 are sectional views taken along lines FIG. 5 is a graph showing the operating characteristics of the two-throttle opener, and is a graph showing the relationship between the boost negative pressure of the engine and the amount of unburned components in the exhaust gas. C1...First carburetor, C2...Second carburetor, T1...First throttle opener, T2...
...Second throttle opener, 31...First
Vaporizer throttle valve, 3.

Claims (1)

[Claims] 1 Opening the corresponding throttle valves of the first and second carburetors, which are divided into at least two or two sets of multiple carburetors, to a specified opening degree in response to the boost negative pressure of the internal combustion engine. The operating negative pressure of the second throttle opener is set higher than that of the first throttle opener, and the opening degree of the throttle valve of the second carburetor by the second throttle opener is set to the first throttle opener. A throttle opener device for a multiple carburetor, which is set to be larger than the opening degree of the throttle valve of the first carburetor by the throttle opener.