JPS5941015B2 - Engine new automatic control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an engine pneumatic system configured so that the operating characteristics of a vacuum motor, which is controlled according to the magnitude of negative pressure generated in the engine intake system, are not adversely affected by changes in atmospheric pressure. This relates to a control device.

The present invention can be applied to an engine intake control device, a mixture concentration control device, an output control device, or an auxiliary device attached to an engine for the purpose of exhaust gas purification or safety measures.

Generally, in a vacuum motor in which atmospheric pressure acts on one side wall of a movable wall such as a diaphragm, and engine intake system negative pressure acts on the other side wall, when the atmospheric pressure changes, the vacuum changes depending on the magnitude of the intake system negative pressure. The operating characteristics of the motor change.

Therefore, conventional exhaust gas recirculation devices using vacuum motors such as those mentioned above, vacuum ignition advance control devices, secondary air supply devices to the exhaust system or intake system, carburetor dashpots, engine intake control devices, mixing The operations of air concentration control devices, output control devices, etc. are affected by changes in atmospheric pressure, and it may be better to make altitude corrections from the perspective of exhaust gas purification or engine output.

By the way, some automobile carburetors have been equipped with an altitude compensation device for altitude correction, but the conventional altitude compensation device has nothing to do with the altitude compensation of the engine's pneumatic control device (it is installed separately). This structure is formed by a bellows or the like having a vacuum chamber, and has the drawbacks that the control characteristics are different from those of the present invention and that it is expensive.

The present invention is an engine pneumatic control device that can correct the air pressure of the vacuum motor with an inexpensive device, in which the vacuum motor is controlled and operated according to the magnitude of the negative pressure in the intake system of the engine. The configuration includes two negative pressure chambers partitioned by the same movable wall, a control means attached to the movable wall, and a spring that biases the movable wall in one direction, each of which has an orifice interposed therein. A pair of negative pressure passages are arranged in parallel, and one end of each of the pair of negative pressure passages is connected to a pressure capo-l- in which a negative pressure pm having particularly desired negative pressure characteristics is generated in the engine intake system. , the other end is opened to the air at atmospheric pressure or pressure Pa exhibiting pressure characteristics close to atmospheric pressure that changes depending on the altitude, and the aperture characteristics of each of the orifices are made different, thereby reducing the pressure of the pair of negative pressure passages. The differential pressure between the two generates negative pressure with different characteristics depending on the magnitude of the negative pressure generated in the pressure port at each specific position, and one of the different negative pressures is applied to one negative pressure chamber of the vacuum motor. , the other is configured to be guided to the other negative pressure chamber of the same vacuum motor.

Next, the present invention will be explained in detail according to embodiments shown in the drawings.

Note that substantially the same parts in each figure are given the same reference numerals.

In a first embodiment of the present invention shown in FIG. 1, a double venturi 3 is disposed inside an intake passage 2 for an automobile vaporizer 1,
A main nozzle 6 opens in an inner venturi 5 arranged substantially concentrically within an outer venturi 4 of the double venturi 3, and a main system fuel passage 9 leading from a float chamber 7 to the main nozzle 6 via a main jet 8. A bleed pipe 10 is fitted inside, and the Air Jets I.11
is provided.

The upper end of the air jet 11 opens into the intake passage 2, and the intake passage is connected to an air cleaner (not shown) on the upstream side, and to each cylinder of the engine via an intake manifold (not shown) on the downstream side.

A throttle valve 12 is interposed downstream of the intake passage 202 and the double venturi 3, and an idle port 13 and a plurality of slow ports 14 are bored in the passage wall forming the intake passage 2 near the throttle valve 12. A pilot jet 16 is installed in a slow system fuel passage 15 extending from the chamber 7 to the ports N3 and 14 via the main jet 8, and the pilot air jet 1 opens into the intake passage 2.
7 is provided.

Further, a valve 18 for opening and closing the slow system fuel passage 15 is provided in the middle of the slow system fuel passage 15, and the quantity valve 18 is connected to the vacuum motor 1.
9, the vacuum motor 19 has a diaphragm 20 with a valve 18 protruding from the center thereof, and two negative pressure chambers 22 and 23 partitioned by the diaphragm 20 within the casing 21 of the vacuum motor 19. , a spring 24 built into the negative pressure chamber 22 and biasing the diaphragm 20 in the direction in which the valve 18 opens.

Further, the carburetor 1 has a pair of valves, the upstream side of which communicates with the upstream side of the venturi 3 of the intake passage 2 via a port 25, and the downstream side of which communicates with the downstream side of the throttle valve 12 of the intake passage 2 via a port 26. Negative pressure passages 27 and 28 are arranged in parallel, and two orifices 29 and 30 are arranged in series in the negative pressure passage 27, which are set to satisfy the characteristics described later. 8 is also provided with two orifices 31 and 32 arranged in series so as to satisfy the characteristics described later.

A negative pressure passage 33 branched from between orifice 29 and orifice 30 of negative pressure passage 27 is connected to negative pressure chamber 22 of vacuum motor 19, and a negative pressure passage 33 branched from between orifice 31 and orifice 32 of negative pressure passage 28 is connected to negative pressure chamber 22 of vacuum motor 19. The pressure passage 34 is connected to the negative pressure chamber 23 of the vacuum motor 19.

In the above configuration, when the engine is driven, negative pressure is generated in the intake passage 2, and especially high negative pressure called intake manifold negative pressure is generated downstream of the throttle valve 12. Through the port 26, the negative pressure passage 27,
Negative pressure is also generated at 28.

By the way, the throttling characteristics of each orifice 29, 30, 31°32 are as follows: With reference to standard atmospheric pressure, the above-mentioned intake manifold negative pressure is Pm, the atmospheric pressure generated in the port I 25 is Pa, and negative pressure is expressed as Pm. The negative pressure generated between the orifices 29 and 30 of the pressure passage 27 is Px, and the orifice 31 of the negative pressure passage 28 is
, 32 is Py, Pyo is Py at Pa=0, and α and β are constants satisfying 1 in α±β, then Px:Pa +a(Pm-Pa) is satisfied,
Further, under the condition of l Pm-Pal > 300 mmHg, that is, under the condition of low-load operation or engine braking operation where the opening degree of the throttle valve 120 is small,
It is set to satisfy Py:Pyo+βPa.

Here, FIG. 2 shows an example of the change characteristics of Px and py with respect to pm, using Pa as a parameter.

In Fig. 2, the solid line and the broken line indicate Pa = 0 (standard atmospheric pressure), Pa = -1,00 mmHg (130 mmHg above sea level).
shows the PxO value at 0.07fl (equivalent to atmospheric pressure),
One-dot chain line and two-dot chain line Pa=O1Pa −-1,0
The value of py at 0 mmHg is shown.

In order to satisfy the condition of Px==Pa+α(Pm-Pa), the passage must be elongated as shown in FIG. 1 or have a labyrinth structure as shown as the orifice 35 in FIG. 300
It is necessary to create a structure in which the pressure above mmHg also reaches the speed of sound and is not choked.

On the other hand, l Pm-Pa l > 300 mmH
In order to satisfy Py + βPa under the condition of g, the orifice 31 should have a structure that exhibits the same characteristics as the above-mentioned orifices 29 and 30, and the orifice 32 should have a flow passage cross-sectional area from the upstream side to the downstream side as shown in Fig. 1. It was rapidly reduced towards
Further, it is necessary to have a structure in which the flow rate rapidly expands after passing the highest constriction point, and when lpm-Pal>300 mmHg or more, the flow reaches the sonic velocity and reaches a critical flow rate.

Px generated in the negative pressure passage 27 is guided to the negative pressure chamber 22 via the negative pressure passage 33, and py generated in the negative pressure passage 28 is guided to the negative pressure passage 23 via the negative pressure passage 34.

Therefore, if the load F acts on the diaphragm 20 due to the differential pressure between Px and Py, and if the area of the diaphragm 200 is A, then A(Px-Py)=F, and the clonic state is Px:P.
a+α(Pm-Pa), Py=Pyo+βPa and α+
When β-1 is substituted, A(αPm-Pyo)=F.

As is clear from the above equation, the load F acting on the diaphragm 20 is a function of only Pm and is not affected by atmospheric pressure.

Therefore, when pm becomes -600 mmHg, the biasing force F' of the spring 24 of the vacuum motor 19 is set to A(α
Pm-Pyo) = F', the engine brake state where the intake manifold negative pressure pm becomes higher than -600mmHg will become F>F',
The valve 18 closes the slow system fuel passage 15 against the urging force of the spring 24.

On the other hand, in a negative pressure operating state where pm is lower than -600 mmHg, the valve 18 is biased by the biasing force of the spring 24 into the passage 1.
5 is open.

Therefore, under normal operating conditions, the valve 18 is open, and in the main system fuel passage 9, the fuel diluted and measured by the air taken in from the air jet 11 is injected from the main nozzle 6 into the inner venturi 5. In the slow system fuel passage 15, fuel that has been diluted and metered with air taken in from the pilot air jet 11 is injected into the intake passage 2 from the idle port 13 and the slow port 14, and when the load is low, the fuel is mainly injected from the slow system fuel passage 15. An appropriate air-fuel mixture is generated by the supplied fuel, and at high load, an appropriate air-fuel mixture is generated mainly by the fuel supplied from the main system fuel passage 9.

By the way, in the engine braking state, the air-fuel mixture taken into each cylinder becomes enriched, but in this example, the intake manifold negative pressure is maintained at 6.5 m without being affected by changes in atmospheric pressure.
When the high negative pressure reaches 007njnHg or more, the valve 18 closes to reduce the fuel supply from the slow system fuel passage 15,
This prevents the mixture from becoming thicker.

Therefore, according to the above embodiment, when the automobile runs at a high altitude, the air pressure decreases, but the intake manifold negative pressure pm is always maintained at the predetermined value set by the spring 24 without being affected by such changes in air pressure. Became 18
The opening/closing operation is carried out, the amount of unburned gas in the exhaust gas is effectively reduced, heat loss of the exhaust gas purification device installed in the exhaust gas passage is prevented, and problems such as afterburn are also prevented. Ru.

By the way, in the above embodiment, the slow system fuel passage 1
A valve 18 is installed downstream of the pilot jet 16 in the passage 15, and a valve 18 is installed in the passage 15 upstream of the pilot jet 16, so that when the valve 18 closes the passage 15, the pilot air jet It may be configured such that only air from 1γ is guided to each port N3, 14.

FIG. 4 shows a second embodiment of the present invention, in which an air passage 36 bypasses the venturi 3 of the intake passage 2 and the throttle valve 12 and communicates from the upstream side of the venturi 3 to the downstream side of the throttle valve 12. The present invention is applied to a coasting valve 37 that opens and closes, and the valve 37 is connected to the center of the diaphragm 20 of the vacuum motor 19 via a rod 38.

Also in the second embodiment, each orifice 29,
30, 31, and 32 are set.

According to this embodiment, when the intake manifold negative pressure pm exceeds a predetermined value, the negative pressure Px generated in the negative pressure chamber 24 and the negative pressure chamber 2
The differential pressure with the negative pressure py generated at 3 overcomes the biasing force of the spring 24, causing the diaphragm 20 to shift to the left in FIG. 4, and the coasting valve 37 also shifts to the left via the rod 38. The air passage 36 is opened, and air is injected from the air passage 36 to the downstream side of the throttle valve 12 in the intake passage 2, thereby preventing the mixture from enriching during engine braking.

Note that an orifice 39 and a check valve 40 that allows air to flow only in the direction of the negative pressure passage 27 from the negative pressure chamber 22 are installed in parallel in the negative pressure passage 33, and the orifice 39 and check valve 40 are provided in a coasting manner. This prevents the valve 37 from notching and also prevents a delay in the opening operation.

FIG. 5 shows a third embodiment of the present invention, in which the operation of the valve 18 is controlled by the vacuum motor 1 in the first embodiment.
The coil 42 of the solenoid valve 41 is directly connected to the battery 45 via a switch 43 and a key switch 44, and the switch 43 is opened and closed by a vacuum motor 19. When the solenoid valve 41 is demagnetized, the slow system fuel passage 15 is closed by the urging force of the spring 46, and when it is energized, the valve 18 is closed by the excitation force against the spring 46.
is configured to open the passage 15.

In this embodiment, when the intake manifold negative pressure pm exceeds a predetermined value, the vacuum motor 19 operates regardless of changes in the atmospheric pressure Pa, and the normally closed switch 43 opens, and in response, the valve 18 closes. The same effects as in the first embodiment can be obtained.

FIG. 6 shows a fourth embodiment of the present invention, in which the valve 18 is replaced by a slow system fuel passage in the first embodiment.
A valve 48 for opening and closing the atmosphere opening hole 47 attached to 5 is provided,
The valve is configured to be opened and closed by a vacuum motor 19, and the diaphragm 2 is connected via a rod 49.
A valve 48 connected to the center of the valve 48 is opened regardless of changes in atmospheric pressure Pa when the intake manifold negative pressure exceeds a predetermined value, and is normally closed by the biasing force of the spring 24.

Therefore, in this embodiment, the engine braking valve 4
8 is opened and a large amount of air flows into the slow system fuel passage 15 from the atmosphere opening hole 47, and in this embodiment as well, enrichment of the air-fuel mixture during engine braking is properly prevented without being adversely affected by changes in air pressure. be done.

FIG. 7 shows a fifth embodiment of the present invention, in which the present invention is applied to a vacuum advance angle control device or an exhaust gas recirculation amount control device of a disk l-1, 1 computer (not shown). According to this embodiment, the advance control of the ignition timing or the control of the control valve that opens and closes the exhaust gas recirculation passage (not shown) is performed by the vacuum motor 19 via the rod 50. According to this embodiment, the ignition is not affected by changes in atmospheric pressure. Advance angle characteristics or exhaust gas recirculation characteristics are obtained, and delays in ignition timing or reduction in the amount of exhaust gas recirculation during high-altitude driving are prevented.

FIG. 8 shows a sixth embodiment of the present invention, in which one orifice 51 is provided in place of the orifices 31 and 32 provided in the negative pressure passage 28 in the first embodiment. ,
The orifice 51 is formed in the shape of a medium-thin nozzle, with a negative pressure outlet hole 52 provided at the most constricted part, and the negative pressure outlet hole 52 is connected to the negative pressure passage 34.The orifice 51 will be described below. It is set to satisfy the characteristics.

That is, let Pz be the negative pressure generated in the negative pressure outlet hole 52,
When Pzo is Pz at Pa=O, l pm-
Under the condition of P a l > 300 mmHg, the velocity of sound near the negative pressure outlet hole 52 is Pz:Pz.

+ () It is set to satisfy P a.

In this case, the orifices 29 and 30 are set to α key ↑ in the first embodiment, and Px key + (Pa-1-P
m) is set to satisfy.

In the sixth embodiment, the same effects as in the first embodiment can be obtained.

As is clear from the above, according to the present invention, various vacuum motors that are controlled according to the magnitude of negative pressure generated in the intake system of an engine can be operated with an inexpensive structure without being adversely affected by atmospheric pressure. It becomes possible to do so.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a vaporizer showing the first embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the above embodiment, and Fig. 3 is a modification of the orifice adopted on the actual flow side. Fragment diagram showing, No. 4
The figure is a cross-sectional view of a vaporizer showing a second embodiment of the present invention, FIG. 5 is a schematic cross-sectional view of main parts showing a third embodiment of the present invention, and FIG. FIG. 7 is a schematic cross-sectional view of a carburetor showing a fifth embodiment of the present invention, and FIG. 8 is a cross-sectional view of essential parts showing a sixth embodiment of the present invention. 1: Carburetor, 2: Intake passage, 12: Throttle valve, 13
: Idle port, 14 Nisro port, 15 Nisro fuel passage, 16: Pilot jet, 18: Valve, 1
9: Vacuum motor, 20: Diaphragm, 22,2
3: Negative pressure chamber, 24 springs, 25, 26: ports,
27, 28: Negative pressure passage, 29, 30, 3L32 niorifice, 33.34: Negative pressure passage, 35 niorifice, 36
: Air passage, 37: Coasting valve, 38: Rod, 41: Solenoid valve, 43: Switch, 47: Atmospheric release hole, 48: Valve, 49, 50: Rod, 51 Niorifice, 52: Negative pressure outlet hole.

Claims (1)

[Scope of Claims] 1. A vacuum motor that is controlled and operated according to the magnitude of negative pressure in the intake system of an engine is connected to a movable wall, two negative pressure chambers partitioned by the movable wall, and a vacuum motor that is attached to the movable wall. The configuration includes a control means and a spring that biases the movable wall in one direction, and a pair of negative pressure passages each having an orifice are arranged in parallel, and each of the pair of negative pressure passages is One end is connected to the negative pressure P of the engine intake system having particularly desired negative pressure characteristics.
m is connected to the pressure port where m is generated, and the other end is connected to the atmospheric pressure P that changes depending on the altitude or exhibits atmospheric pressure characteristics close to it.
By opening into the air in the state of state a and making the throttle characteristics of each of the orifices different, both of the orifices are placed at specific positions in each of the pair of negative pressure passages depending on the magnitude of the negative pressure generated in the pressure port. The differential pressure between generates negative pressure with different characteristics,
A pneumatic control device for an engine, characterized in that one of the negative pressures is guided to one negative pressure chamber of the vacuum motor, and the other is guided to the other negative pressure chamber of the vacuum motor. 2. In the device according to claim 1, each of the pair of negative pressure passages is provided with at least two orifices in series, and the throttling characteristic of each orifice is equal to that of the pair of negative pressure passages. Among the passages, the negative pressure Px generated between a specific orifice in one of the negative pressure passages and the negative pressure py generated between a specific orifice in the other negative pressure passage are determined by the magnitude of the negative pressure pm generated in the pressure port. A pneumatic control device for an engine, characterized in that the differential pressure between the two is set to exhibit different characteristics depending on the pressure, and the negative pressures Px and Py are guided to each negative pressure chamber of the vacuum motor. 3. In the device according to claim 2 above, P
y, Pa, pm, Pyo are standard atmospheric pressure standards, Pyo
is py at Pa=0, and α and β are constants satisfying α+βf−1, then Px×Pa+α(Pm−Pa
), and I Pm-Pal > 300 m
A pneumatic control device for a tossing engine, characterized in that it is set to satisfy Py f - Pyo + βPa under mHg conditions. 4. In the device according to claim 1, the pair of negative pressure passages are arranged such that the first negative pressure passage has at least two orifices interposed in series, and the first negative pressure passage has at least one orifice interposed therebetween. and a second negative pressure passage equipped with the first negative pressure passage.
Negative pressure Px generated between specific orifices of the orifices installed in the negative pressure passage and negative pressure Pz generated in the specific orifice installed in the second negative pressure passage are generated in the pressure port. The differential pressure between the two is set to exhibit different characteristics depending on the magnitude of the negative pressure pm, and the negative pressure Px, P
A pneumatic controller for an engine, characterized in that z is guided to each negative pressure chamber of the vacuum motor.
-L device. 5 In the device according to claim 4 above, P
When x, Pz, pm, and Pa are standard atmospheric pressure standards, P
x f:+ (P a + Pm) is set to satisfy, and when Pzo is set to pz at Pa=0,
l Under the condition of Pm-Pa l>300mmHg, Pz
A pneumatic control device for an engine, characterized in that it is set to satisfy f-Pzo +-)Pa.