JPS5815760A - Fuel feed device having low speed injector - Google Patents

Abstract

PURPOSE:To obtain stable air-fuel ratio at low speed and improve driveability in a main nozzle range, by providing an injector nozzle in the downstream of a throttle valve and controlling the injector nozzle through a feedback signal of an engine operational condition and air-fuel ratio in a main nozzle range. CONSTITUTION:In an operational range of a small intake air quantity to an engine 1, fuel is not fed from a main nozzle 7, and fuel, injected from an injector nozzle 12, is fed to the engine 1. In this case, an opening time of the injector nozzle 12 is controlled by an output signal of a computer 21 on the basis of each signal from an exhaust concentration sensor 22, cooling water temperature sensor 23 and intakef pipe negative pressure sensor 24, and a speed signal 25 of the engine. Further in a main nozzle range, an injector 11 performs correction of air-fuel ratio through feedback control by the computer 21 received with a signal from each sensor, to feed optimum fuel to the engine 1.

Description

[Detailed Description of the Invention] This invention is an internal combustion engine (hereinafter also referred to as an engine) that stabilizes the air-fuel ratio during low-speed operation by attaching a combination fuel-controlled injector to a carburetor that does not have a slow system fuel passage. ) relates to a fuel supply device for

Conventionally, as shown in FIG. 3, the slow fuel passage of a carburetor has promoted mixing of fuel and air and atomization and atomization of the fuel by air bleed. however,
When fuel and air are mixed, the inside of the slow system fuel passage 41 becomes a mixed flow consisting of two phases of gas and liquid, which flows in a double-track pattern (piston flow, slug flow, and froth flow). , the ratio of air and fuel changes over time, which causes fluctuations in engine speed and causes deterioration in drivability.

There is also the problem that drivability deteriorates due to fluctuations in the air-fuel ratio during the transition between the slow system 42 and the main system 43, which is unique to the carburetor.

Furthermore, electronically controlled fuel injection devices (e.g. EF I).

In a fuel injection device using an injector such as an EGI (eg, EGI) or a single point fuel injection device, it is not easy to ensure the maximum fuel flow rate of the injector. In addition, the particle size of the fuel injected from the injector is large, making it difficult to achieve good combustion within the engine, which further reduces drivability.

An object of the present invention is to provide a fuel supply system that stabilizes the air-fuel ratio during low-speed operation of the engine and enables feedback control of the air-fuel ratio in the main range, thereby improving engine drivability.

The present invention will be described below based on drawings showing embodiments. In Fig. 1, 1 is an engine, 2 is an intake manifold pipe,
3 is an exhaust pipe. Reference numeral 4 denotes a carburetor, which has a main nozzle 7 opened in a pliers-shaped portion 6 in an intake passage 5, and is supplied with fuel from a float φ chamber 9 through a main fuel passage 8. 10 is the throttle pulp. 11 is an injector, and injector nozzle 12 is a throttle
It is located at the opening of the intake passage side wall 5a on the downstream side of the pulp 10. Fuel in a fuel tank 13 is pressurized by a fuel pump 14, regulated by a regirator 15, and then fed into the injector 11. Regi.

The rotor 15 has a negative pressure chamber 16 and a fuel chamber 17, with a diaphragm 18 partitioning the two. The pressure in the fuel chamber 17 is regulated by nine compression springs 19 housed in the negative pressure chamber 16 and negative pressure introduced from the intake manifold pipe 2 . The fuel chamber 17 communicates with the fuel pump 14 and the fuel tank 13 through fuel passages 20m and 20b, respectively. Reference numeral 21 is a combination sensor which receives signals from an exhaust temperature sensor 22, a cooling water temperature sensor 23, an intake pipe negative pressure sensor 24, and an engine speed signal 25, and injects an injector IIK.
A control signal is sent according to the operating state of the engine 10.

FIG. 2 shows an embodiment in which a bypass air passage 31 bypassing the throttle pulp 10 is provided.

The inlet 311 of the bypass air passage 31 is connected to the throttle
It opens at the intake passage side wall 5bK on the upstream side of the pulp 10 and merges with the opening of the injector nozzle 12 on the downstream side of the outlet line throttle pulp 10. An air swirl guide 32 is installed at the outlet of the bypass air passage 31, and an air swirl guide 32 is installed at the outlet of the bypass air passage 31, and the bypass air
A nozzle 33 is attached.

In the fuel supply system configured as described above, in an operating range where the intake air amount of the engine 1 is small, there is no fuel supply from the main nozzle 7, and the injector nozzle 12
Fuel injected from the engine is supplied to the engine 1. That is, the injector 11 serves as a substitute for the conventional slow system fuel passage. The fuel injected from the injector 11 is pressurized by the fuel pump 14 in the fuel tank 13, and is always regulated to a constant pressure by the intake pipe negative pressure control of the regirator 15. Therefore, injector 1
The fuel flow rate supplied by 1 is determined by the opening time of the injector nozzle 12.

The opening time of the injector nozzle 12 is feedback-controlled by a signal from the combination nozzle 21 so as to supply a fuel flow rate that provides an optimum air-fuel ratio depending on the operating state of the engine 1. That is, the combination signal is based on signals from the exhaust gas concentration sensor 22, the cooling water temperature sensor 23, the intake pipe negative pressure sensor 24, and the engine speed signal 25.
According to the output signal of 1, the injector nozzle 2, L2
The opening time of the injector 11 is controlled thereby.
The fuel flow rate is controlled so that it is in the optimal state required by the engine l.

As the intake air amount of the engine 1 increases, the fuel in the flow chamber 9 is discharged from the main nozzle 7. In this case, the fuel discharged from the main nozzle 7 is preliminarily reduced to a large extent. The air-fuel ratio is corrected through control to ensure optimal fuel supply to the engine 1.

Furthermore, in the second invention of the present application, as shown in FIG. 2, air is introduced into the tip of the injector nozzle 12 through the bypass air passage 31 to promote atomization of the fuel injected by the injector 11.

At this time, the air swirl at the bypass air outlet (by the β-id 32)
is generated, and the fuel is atomized.

As explained above, this invention combines a carburetor without a slow fuel system with an injector that injects fuel by positive pressure, and the injector nozzle is located downstream of the throttle valve of the carburetor. Equipped with an output scombinator, which sends a control signal to the injector to inject fuel for low-speed operation in response to a signal indicating the engine operating status, and also to perform feedback control of the air-fuel ratio applied to the main range. This fuel supply device eliminates the conventional fuel discharge system using a gas-liquid two-phase mixed flow in the slow system fuel passage, stabilizes the air-fuel ratio during low-speed operation, and improves engine drivability. effective.

Furthermore, feedback control of the air-fuel ratio in the main region is enabled, and a mixture with an optimum air-fuel ratio can be supplied to the engine, thereby improving engine drivability.

Furthermore, since the injector is used only for supplying low-flow fuel, there is an advantage that the injector can be used without the problem of ensuring the maximum flow rate.

It has the effect of improving engine drivability by eliminating air-fuel ratio fluctuations in the slow system and main system (switching between the slow system and main system).

The second invention has the structure of the first invention further provided with an air swirl guide, nine bypass air passages are provided, and the air outlet is merged with the injector nozzle to obtain the nine structure. In addition to this effect, it also promotes atomization and atomization of the injected fuel, making combustion in the engine smoother, reducing fluctuations in engine speed, and thus improving engine drivability.

[Brief explanation of the drawing]

The figures show an embodiment according to the present invention, and Fig. 1 is a longitudinal cross-sectional view of the entire fuel supply system of the first invention including an engine, and Fig. 2 shows a bypass air passage and a main part of the invention of Odate 2. The vertical cross-sectional view, FIG. 3, is a cross-sectional view of a conventional carburetor OIm. G...Intake passage 7...Main nozzle 11...Injector 13...Fuel tank 14...Fuel bonder 15...Regi island regulator 1
8...Diaphragm 21...Combinator 31.
...Bypass air passage 32...Air swirl guide Patent applicant Aisan Kogyo Co., Ltd.

Claims (1)

[Claims] (1) Main nozzle and float in the bench trim section
A carburetor includes a main fuel passage communicating with a chamber and a throttle valve at the bottom of the intake passage, and an injector nozzle is attached to the side wall of the intake passage downstream of the throttle valve and is controlled by a fuel pump and a regulator. Signals and engine speed signals from an injector that injects the pressure-regulated fuel from the fuel tank into the intake passage, an exhaust gas concentration sensor, a cooling water temperature sensor, and an intake pipe negative pressure sensor attached to the internal combustion engine. A fuel supply device for an internal combustion engine, which is configured to include a conbeater that causes the injector to inject fuel at low speed operation in response to the above, and sends a control signal to the injector that causes feedback control of the air-fuel ratio in the main region. (It is equipped with a main fuel passage that communicates between the main nozzle and the float chamber in the main part, and a throttle valve at the bottom of the intake passage.)
The nozzle is attached to the side wall of the intake passage downstream of the throttle pulp, and the injector is pressurized and regulated by a fuel pump and regulator and injects the fuel from the nine fuel tanks into the intake passage, and the nozzle is attached to the internal combustion engine. In response to signals from an exhaust concentration sensor, a cooling water temperature sensor, an intake pipe negative pressure sensor, and an engine rotation speed signal, a control signal is generated to cause the injector to inject fuel at low speed operation, and to feedback control the air-fuel ratio in the main region. Communication is provided between a combeater that sends air to the injector, an inlet that opens on the side wall of the intake passage upstream of the throttle valve, and an outlet that opens to join the opening of the injector nozzle and is equipped with an air swirl guide. A first fuel supply device for an internal combustion engine, which is composed of a bypass air passage.