JPS5922068B2 - Internal combustion engine fuel injection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel pump having a body forming an air intake duct and directing fuel from an inlet to the pump body toward an outlet for supplying one or more fuel injectors. A device is provided between the inlet and outlet portions of the pump body and is adapted to time the engine crankshaft or other rotational output member for delivering a metered amount of fuel toward the outlet for each operating cycle of the engine. A metering device driven in conjunction with the engine, a detection device acting on the metering device to detect the amount of fuel, and an auxiliary pressure to detect when the engine is rapidly accelerated. The present invention relates to a fuel injection device for an internal combustion engine (hereinafter referred to as a designated type of fuel injection device), which is provided with a detection device.

The present invention relates to a specified type of fuel injection device intended for use in an engine having one or more cylinders and an ignition device for igniting the air-fuel mixture in the cylinders by a spark discharge. This was done by

The invention also comprises a metering cylinder containing a free piston element or a shuttle piston element movable between stops, the distance between said stops being such that the distance between the stops determines the amount of fuel supplied during each stroke of the free piston. The cylinder spaces on both sides of the piston are respectively connected to the pump and the outlet via a commutator valve during continuous operation, in each case the other cylinder space being connected to the outlet and It has been developed in conjunction with specified types of fuel injection devices each coupled to a pump.

If the fuel injection system is to be used in a multi-cylinder engine, the outlet section is provided with a plurality of outlets, and the commutator valve is combined with a distribution valve system or made as a distribution valve system, each of which is connected in an appropriate sequence. Supply fuel from the outlet.

One of the requirements that should be met in order to achieve satisfactory performance of the engine is to temporarily enrich the mixture (low air to fuel ratio) and use the specified type of fuel injector. A vehicle equipped with an engine that has
This is to meet a sudden demand for increased power, such as when acceleration is caused by a sudden opening of a throttle valve.

The main objective of the invention is to provide a simple, reliable and economical fuel injection device.

According to the invention, the detection device includes an air pressure detection device (herein referred to as main pressure detection device) for detecting the air pressure in the air intake duct, a temperature responsive device for detecting the air temperature, and a temperature responsive device (for slow opening of the throttle valve). and an auxiliary pressure sensing device configured to detect sudden changes in air pressure, such as those caused by the sudden opening of a throttle valve, and the settings of the metering device are determined by a combination of sensing parameters. The sensing devices each provide a mechanical output that is combined with a mechanism connecting the sensing device to the metering device so that a specified type of fuel injector is obtained.

In an internal combustion engine where air-fuel mixture is supplied through a carburetor, if the engine is equipped in a vehicle, the acceleration of the engine will be reduced if the throttle valve is suddenly opened, such as by suddenly stepping on the accelerator pedal. There is a momentary delay before this occurs.

The reason for this delay is that there is a relatively long original mixture column between the carburetor and the engine intake valve, and the length is about 30 to 50 crn (about 12 to 20 inches). Until this mixture column is combusted by the engine,
This is because the engine does not receive the extra air and fuel required to accelerate it.

In order to eliminate or reduce such undesirable effects, an accelerating piston is provided which operates in a chamber containing liquid fuel and which supplies extra fuel into the air inlet duct when the piston is jerked. It is common practice to have a vaporizer with a

The increase in fuel supply occurs before the throttle valve is opened to proactively meet engine demands by enriching the mixture column before it reaches the engine intake valve. , the piston is typically actuated by a link connected to a slotted link.

This method is effective in reducing acceleration delays.

On the other hand, once acceleration occurs, the mixture ratio in the air-fuel mixture column becomes extremely small, which can lead to severe air pollution in traffic conditions where many vehicles are forced to repeatedly stop and accelerate. I'll wake you up.

Although the preferred embodiment of the present invention uses an accelerating piston as described below, it is quite different from the conventional practice.

In the present invention, the increment of fuel is delivered by the same injector normally used to inject fuel into the engine's intake manifold, but the timing of this increment is determined by the air flow caused by the opening of the throttle valve. Determined by the increase in absolute pressure in the intake duct.

The length of the mixture column enriched in this way is much shorter than that of an engine using a carburetor.

This is because the fuel injectors are mounted in the intake manifold close to the intake valves of the engine, so that the enrichment phenomenon that occurs in carbureted engines due to the long mixture column is completely avoided.

A main pressure sensing device responds to the absolute pressure in the duct, and an auxiliary pressure sensing device responds to the difference between the air pressure in the duct after the throttle valve is opened and the air pressure in the device body before the throttle valve is opened. It is preferable to do so.

In one embodiment of the invention, the main pressure sensing device comprises an evacuated deformable container that is compressed by pressure and expanded by a spring, and the main pressure sensing device is controlled by an auxiliary pressure sensing device in the air inlet duct. and the position of the primary pressure sensing device also moves in response to the operation of the auxiliary pressure sensing device, but when the primary pressure sensing device expands due to an increase in air pressure in said air intake duct. moves in the direction of increasing output.

The main pressure sensing device can therefore include an evacuated bellows.

One end of this bellows is disposed in conjunction with an auxiliary pressure sensing device, and the other end is connected to the mechanism.

The auxiliary pressure sensing device may include an acceleration cylinder within the body of the device, including an acceleration piston biased toward the air intake duct, the acceleration piston being biased towards the acceleration cylinder in response to an increase in absolute pressure within the air intake duct. the duct is moved within the duct in a direction away from the duct.

A leakage device is provided on the accelerator piston and accelerator cylinder assembly to allow the piston to return to its original position under the action of said biasing device.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

A complete fuel supply system for a fuel injection system and an example of its construction are described in British patent application no.
It is explained in detail in No. 72.

Before explaining in more detail the fuel supply device and the fuel injection device of the embodiment of the fuel injection device of the present invention, an example of the fuel supply device and its structure described in the above-mentioned patent application will be explained.

The fuel supply system shown in FIG. 1 includes a fuel tank 10. The fuel supply system shown in FIG.

From this fuel tank, fuel is supplied from a pipe 11 to an inlet of a fuel injection device 15 through a filter 12, a low pressure pump 13, and a pipe 14.

Excess fuel is returned to tank 10 via pipe 32.

Fuel injector 15 is shown in FIG. 1 as mounted on an intake manifold 16 of a V-cylinder internal combustion engine 17.

This internal combustion engine 17 has fuel injectors 26, which are supplied with fuel by a pipe 27 from the outlet of the fuel injection device.

Fuel injector 26 includes a spring loaded injection valve.

These injection valves are normally closed, but open in response to a constant injection pressure of fuel supplied to the injector.

A rotary vane high-pressure pump 18 generates the required injection pressure and supplies fuel, such as petroleum, from its inlet side 14a via a diversion and distribution valve arrangement 19 to a metering device 20.

The valve 19 also functions to continuously distribute fuel to six outlet sides which are metered by the action of the free piston 20a of the metering device 20 and which are connected by pipes 27 to the injectors 26.

Excess fuel is returned to pipe 325 via blow-off valve 31.

The stroke of piston 20a of metering device 20 between stops 20b and 20c is determined by detection device 29.

The metering device includes an evacuated bellows 29a to detect the absolute pressure within the chamber 34.

The chamber 34 forms part of an air intake duct in which the intake of air is controlled by a throttle valve section 35 having a manually operable butterfly valve plate 36.

The air temperature in the chamber 34 is detected by a wax capsule temperature sensing element 37 and further temperature parameters, such as the temperature of the engine coolant, are detected by a temperature sensing device 38.

The displacements of the temperature detection elements 37 and 38 in the axial direction are such that one displacement is added to the other displacement inside an adding mechanism 39.

The output element of this mechanism is a rotating sleeve 40, onto which one end plate of the bellows 29a is fixed.

A cam element 41 is additionally added to the other end plate of the bellows, and this cam element 41 has a truncated conical cam surface that is eccentric with respect to the shaft 41a, and the cam element 41 has a cam surface eccentric to the shaft 41a. Axial displacement and temperature detection element 37
．． The movement of the cam element 41 adjusts the position of the lower stop 20c of the metering piston via a cam roller rolling in contact with the cam element 41. Mepet 42
can be added to.

FIG. 5 shows the overall configuration of the metering device 20 and the commutation and distribution valve device 19, as well as the mode of their operation.

This commutation/distribution valve device 19 is for 6 cylinders, and the rotary valve plates 48 and 49I/'i planes are connected, and the flat part 48a of the plate 48 engages with the carrier 47, and these are integrally connected. The crankshaft 23 is connected to the rotating shaft 21 so that it can be rotated by 1/2 rotation of the crankshaft 23.

A T-shaped recess passage is formed in the left side of the valve plate 48, the rim b6 of this passage overlaps the port d of the plate 49 and is longer than the other rims b2 and b4.

The rotary valve plate 48, 49 has a port indicated by the letter bye and corresponds to the port f of the cylinder block.

Furthermore, the subscripts 1 to 6 attached to these letters refer to specific outlets g1 to g6, that is, engine cylinders No. 1 to 6.
It corresponds to the number injector 26.

Ports a1, bl, and cl are in communication with each other, and ports a3, b3, and c3, and ports a5, b5, and c5 are also provided in communication with each other.

Solid arrow 43 indicates high pressure pump 18 in one operating cycle.
The dashed arrow 45 shows the flow of fuel from the lower cylinder space S2 to one of the outlets g6.

In this operating cycle, the fuel from the high pressure pump is at port a1.
, bl, cl and the port e1 of the cylinder block to reach the cylinder space S1.

As a result, the metering free piston 20a moves downward, and the fuel in the cylinder space S2 is transferred to the ports e2, c4, b3, the rims b4 and b6 of the T-shaped passage, and the port d%f61g6.
It reaches the trajector 26 via the path.

If the engine rotates 120°, i.e. carrier 4
1 and play) 48.49 is 6 clockwise in Figure 5.
When rotated by 0°, ports a5, b5, and c5 communicate with port e2 of the cylinder block.

The high pressure fuel then flows into the cylinder space S2.

As a result, the free piston moves upward, the fuel in the cylinder space S1 is pushed out, and the ports e1 and c2 are
through the T-shaped passage in plate 48, port d in plate 49, outlet ports) f5 and g5 to the injector.

When carrier 47 and plate 48.49 further rotate 60° clockwise, ports a3, b3, and c3 will open to port e.
1 and the metering piston moves downward again.

The fuel metered in this manner is sequentially supplied to each cylinder.

At the starting speeds that can be obtained with the starting motor attached to the engine, the pressure of the fuel supplied by the high pressure pump 18 is too low for the injector 26 to inject fuel.

Therefore, a carburetor 30 as shown in FIG. 3.4 is provided.

This carburetor is equipped with a cylindrical internal jet element 55, and the fuel sent from the low pressure pump 13 is supplied to the internal passage 70 after passing through the inlet 14a, passes through a limit valve 57 that opens at a predetermined low pressure, and enters the jet element 55. enter.

This fuel flows into a chamber 60 connected to the air intake vibro 0a, passes through an orifice 59 provided circumferentially opposite the outer cylindrical jet element 58, and then passes through a passage 60b to the main air amplification chamber. 34.

Air drawn through suction tube 60a, chamber 60, and passageway 60b breaks up the fuel exiting internal jet element 55 and passing through orifice 59 into fine particles, as in the slow jet of a conventional carburetor.

External jet element 58 is formed as part of plunger 61 .

The plunger moves from the position in which it is held by the spring 62 to its operating position in the high pressure pump 18.
The space 63VC is driven by fuel which is directed from the outlet side of the space 63VC through an inlet 63a and a passage 63b leading to the chamber 65.

Fuel is supplied to the chamber 65 from the outlet side of the high-pressure pump 18 through a hole 65a, and when the high-pressure pump 18 generates sufficient pressure to inject fuel from the injector 26. , the plunger 61 moves and the fuel shutoff valve 64 closes the end of the internal jet element 55, blocking air and fuel from passing through the carburetor to the passageway 60b.

The supply pressure of the high-pressure pump is determined by the blow-off valve 31.

Fuel from the outlet side of the high pressure pump is admitted into chamber 65.

This fuel passes through the filter 66 and the hole 6T, and the spring 6
9 opens the blow-off valve element 68, and excess fuel flows from the passage 70 to the add-on 56, which has a flow path leading to the pipe 32, although not specifically shown. from there through pipe 32 and back into the tank.

Because each injector 26 is located in close proximity to the intake valve of its associated cylinder, the air-fuel mixture is delivered from the injector at a much shorter time interval than in engines where the mixture is supplied via a carburetor. The supplied fuel is injected into the cylinder.

This is because the length of the mixture column that exists between the fuel supply point, that is, the engine intake valve and the injector, is much hotter than the length of the mixture column when using a carburetor. .

This becomes clear when considering a single carburetor engine in which the two cylinders at each end of the engine's cylinder block are farther from the carburetor than the remaining cylinders.

In this case, a relatively long mixture column exists between the intake valves of the two cylinders and the jet assembly of the carburetor where the fuel supply takes place.

Therefore, there is still some difficulty in ensuring that the engine accelerates without delay due to the rapid opening of the fuel injector throttle valve, but this problem is also comparable to that encountered in engines using carburetors. If you do that, it's not a big deal.

Based on these differences, the throttle can be opened suddenly without incurring the air pollution that results from the enrichment of a long mixture column that exists in conventional engines using carburetors. The present invention provides a device with a simple structure, high reliability, and low cost, which temporarily enriches the air-fuel mixture entering the intake valve of an engine when the air-fuel mixture enters the intake valve of an engine.

In engines using a carburetor, the mixer enrichment device is operated in conjunction with the throttle valve link and is designed to operate shortly before the throttle valve is fully opened. The device employed in the present invention responds to the air pressure within the chamber 34, whereas the device employed in the present invention responds to the air pressure within the chamber 34. The bellows 29a is expanded and contracted to adjust the position of the stop 20c via the cam element 41, and is further provided with an auxiliary pressure detection device that responds to temperature and is linked to the pressure response detection device. It has become.

The auxiliary pressure detection device connects the addition mechanism 39 via the ball bearing 51.
The accelerating piston 50 is rotatably supported by the output sleeve 40 of the accelerating piston 50.

This accelerating piston moves in a Calorie cylinder T1 formed in the body 33 of the device.

The bearing 51 is substantially sealed, but has a structure that allows air to leak little by little from one side to the other.

Therefore, when the throttle valve 36 is suddenly opened, the absolute pressure in the chamber 34 increases and the piston 50 is moved to the right in the figure against the force of the spring 52 used in the summing mechanism 39.

The air pressure on the right side of the piston is the pressure that existed in the chamber before the throttle valve was opened.

The bellows 29a, which has a right end plate that contacts the mating member 51 provided on the shoulder of the sleeve 40, also connects to the cam element 4.
1 and move to the right side, Mepet 42 and lower stop 2
0c downward to increase the stroke of the free piston 20a.

Therefore, the metered amount of fuel delivered on each stroke instantly enriches the boosted old-1 mixture.

The piston gradually returns to its original position under the action of spring 52 at a speed determined by the rate of air leakage through bearing 51.

With this configuration, air pollution is greatly reduced.

Movement of the piston 50 to the right is received by the summing mechanism 39.

The adding mechanism 39 has two sleeves 72, 73 which are axially fitted into each other.

Each sleeve is provided with two slots facing each other on the circumference and extending in the direction of the axial force, and arms γ2a and 73a are left between the slots.

Since the arm of one sleeve is slidably fitted in the slot of the other sleeve in the axial direction, the two sleeves can move relative to each other in the axial direction.
They are in an alternating driving-following relationship.

The sleeve 72 can be moved in the axial direction by the temperature detection element 37, and has a spiral groove T4.

This helical groove is secured to the output sleeve 40 of the summing mechanism and engages a pin 75 projecting radially inwardly therefrom.

The sleeve γ3 also has a helical groove 76 which engages a pin 77 which is fixed to a housing 78 which is fixed to the main body 33.

The spring 52 pushes the sleeves apart so that each sleeve 72,73 remains in contact with the output of the temperature sensing device 3.gamma., 38.

Due to the expansion of the temperature detection element in the direction of axis B, the sleeve 12°73
When any one of the sleeves is moved in the axial direction, the amount of rotation of this sleeve increases, and this increase is added to rotate the output sleeve 40.

This rotation is transmitted from the bellows through the cam element 41 and via the mepet 42 to the lower stop 20c.

When the accelerating piston 50 moves to the right, the piston 50 carries the output sleeve 40 together with the temperature sensing element 37 and the sleeve 12.

Sleeve 72 and sleeve 73 have the above-described interfitting relationship.

It slides against the sleeve 73.

However, since there is no relative movement between the pin 75 and the sleeve 72, even if the accelerating piston 50 moves, no rotational component occurs in the movement of the sleeve 40.

The present invention is configured as described above, and instantly responds to the air pressure and temperature in the air intake duct by opening the throttle valve, and maintains l/'i not only during normal operation of the engine, but also during acceleration. It is designed to inject a certain amount of fuel.

Generally, internal combustion engines that supply a mixture of air and fuel using a carburetor are equipped with an accelerating piston device, which pushes the piston through a link device in response to the operation of a throttle valve during acceleration to increase the amount of fuel supplied. However, when vehicles repeatedly stop and accelerate, the mixture ratio is not maintained properly, resulting in severe air pollution.

In contrast, the present invention provides a metering cylinder with a commutation and distribution valve device and a free piston element between the fuel injector and the fuel pump, and also includes a metering cylinder with a free piston element for detecting the amount of fuel. A working detection device is provided.

The main pressure detection device provided in the detection device is connected to an auxiliary pressure detection device for detecting rapid fluctuations in air pressure within the duct.

During normal operation of the engine, the main pressure detection device injects the appropriate amount of fuel from the injector, and during acceleration, the auxiliary pressure detection device operates according to fluctuations in air pressure inside the tank, thereby injecting the appropriate amount of fuel. is injected from said injector.

Therefore, there is no delay in fuel supply during acceleration, and excessive enrichment can be avoided, making it possible to save fuel and prevent air pollution, which is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the main parts of a fuel supply system equipped with the fuel injection device of the present invention, FIG. 2 is a sectional view showing the structure of an embodiment of the fuel injection device of the present invention, and FIG. FIG. 4 is a cross-sectional view taken along line 3-3 in FIG. 2 showing a carburetor used in the fuel injection device of the invention; FIG. FIG. 5 is a diagram showing the overall configuration and operation of a metering device including a metering piston, a cylinder unit, and a commutation/distribution valve device. 15... Fuel injection device, 18... High pressure pump, 19... Commutation/distribution valve, 20...
...Measuring device, 20a...Cree piston, 29
a... Bellows, 30... Carburizer, 2
6... Fuel injector, 37, 38... Temperature detector, 55... Internal jet element, 58...
...External jet element, 50 ... Acceleration piston, 71 ... Acceleration cylinder.

Claims (1)

[Scope of Claims] 1. A body forming an air intake duct; a fuel pump conveying fuel from an inlet to an outlet, the outlet connecting to one or more fuel injectors; a metering device located between the inlet and the outlet for delivering a metered amount of fuel to the outlet for each operating cycle of the engine; and a sensing device for adjusting the metering device to determine the amount of fuel supplied. The detection device includes a main pressure detection device, a temperature detection device that detects the air temperature in the duct, and an auxiliary pressure detection device that detects a sudden change in air pressure in the duct, and the main pressure detection device includes: an evacuated deformable container that is contracted by air pressure and expanded by a spring is movably added to the duct, and the temperature sensing device is provided in operative connection with the main pressure sensing device. The detection value is determined by integrating the change values of the rain detection device, and the auxiliary pressure detection device is connected to the main pressure detection device and is movably installed in the duct, The main pressure detection device changes its position in response to the movement of the auxiliary pressure detection device, and moves so that an increase in the absolute pressure in the duct causes a container constituting the main pressure detection device to contract and increase its output. A fuel injection device for an internal combustion engine characterized by: 2. The main pressure sensing device has an evacuated bellows, and one end of the bellows is connected to an auxiliary pressure device, the auxiliary pressure device has an acceleration cylinder in the device body, and the cylinder includes an acceleration piston. , the accelerating piston is pushed towards the air intake duct by a biasing device;
A fuel leakage device is provided for movement within the acceleration cylinder in a direction away from said duct in response to an increase in the absolute pressure in the air intake duct, and is associated with the acceleration piston and acceleration cylinder assembly to control the action of said biasing device. 2. The fuel injection device according to claim 1, wherein the accelerating piston is downwardly movable to return to its original position.