JPS5825867B2 - 2 Jiku Uki Beno Sonaeta - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes an injection device, a throttle valve disposed in an intake pipe, and a secondary air valve.
The present invention relates to an internal combustion engine for compressing an air-fuel mixture, which is arranged in a bypass passage that goes around a throttle valve, and whose passage cross-sectional area is adjusted depending on the temperature.

Various secondary air valve systems are used in known injection devices.

2, including a rotatable control piston with a control groove disposed around the circumference and a bimetallic spring formed in a spiral shape;
Sub-air valves are also known.

There, a bimetallic spring is immersed in the lubricating oil circuit of the internal combustion engine and is arranged in such a way that it only blocks the bypass around the throttle valve when the lubricating oil has risen to the operating temperature of the internal combustion engine.

Known secondary air valves are relatively expensive to manufacture and also require that the internal combustion engine have a sufficient reservoir of lubricating oil to ensure the necessary heat transfer to the bimetallic spring.

The object of the invention is to propose a secondary air valve for a fuel injection system, which allows the no-load air amount to be determined in a simple manner during warm-up.

The invention provides that the secondary air valve has a vane member with a window-like passage opening, which vane member is swingable about an axis by a bimetallic spring that can be heated by at least one electric heating element; and, during the oscillating movement, at least partially covers the cross section of two air guide channels which are spaced apart from one another and belong to the bypass channel, the vane member, at least in the closed position, controlling the direction of the flow of the secondary air. It is proposed that, downstream of the vane element, it is in close contact with a packing lip surrounding the air guide channel.

The vane element is advantageously designed as a stamped part, the stamped piece being adapted to the shape and construction of the internal combustion engine.

The configuration of the present invention described above provides the following effects.

First, by providing a window-like passage opening in the vane member of the air valve, the amount of secondary air can be adjusted accurately.

A bimetallic spring that can be heated by an electric heating element is used to enable the blade member to pivot about its axis, so that when this heating element is energized at the start of the internal combustion engine, the bimetallic spring is heated to a predetermined value corresponding to the heating function of the internal combustion engine. heating according to the time constant of , the vane member can shut off the bypass precisely as soon as the internal combustion engine reaches operating temperature.

By placing the two air conduits spaced and facing each other, and by providing a sealing lip around the opening of the second air conduit downstream of the vane member in the direction of secondary air flow, the vane member may It is necessary to cover a smaller area, and the closing effect is enhanced because it is tightly adsorbed to the gasket lip by the negative pressure of the intake pipe acting from the second air conduit.

Embodiments will now be described in detail with reference to the figures.

The gasoline injection device shown in FIG. 1 is for operating a four-cylinder internal combustion engine 10 used as a drive device for an automobile, and its spark plug 11 is connected to a high-voltage ignition device (not shown).

Directly in the vicinity of the not shown intake valves of the internal combustion engine, an electromagnetically actuated injection valve 13 is located on the manifold of the intake pipe 12 leading to the individual cylinders.

Fuel is introduced into each injection valve from a distributor 15.

Fuel is drawn from the fuel tank 18 in the distributor and in conduit 14 by means of an electromagnetically driven pump indicated at 16, the distributor 15 serving to maintain the pressure of the fuel in front of the injection valve at a practically constant value of about 2 cage pressures. pressure regulator 1 installed in front of
7.

Each injection valve 13 has a magnetized winding (not shown), one end of which is grounded, while the other end is connected to the
1 of the resistors 20.

Each resistor 20 is connected to the collector of an output run sister, indicated at 21, which receives a square wave pulse at each rotation of the crankshaft 24 via a transistor amplifier 22 by means of an electronic control device to be described in detail below. , and at the same time supplies a current that opens the injector 13 for the duration of this pulse.

The injection quantity reaching into the intake pipe and from there to the cylinder in each injection stroke, which must be adapted to the respective operating conditions of the internal combustion engine, is proportional to the opening duration.

The control device 25 used for this purpose is shown surrounded by a broken line in FIG. 1 and consists essentially of a monostable relaxation oscillator including a first relaxation oscillator transistor T1 of pnp type and a second relaxation oscillator transistor of the same type. .

The emitters of both transistors are connected via a positive conductor 26 to the positive terminal of a vehicle battery (not shown) having a nominal voltage of 12.6 V and used as an operating power source.

A load resistor 27 is connected from the collector of the first transistor T1, and a load resistor 28 is connected from the collector of the second transistor to a negative conductor 29 which is connected to the negative pole of a common ground-connected vehicle battery.

In the rest state of the relaxation oscillator 25, the transistor T
, is kept conductive by a resistor 30 connected from its base to a negative conductor 29, and the transistor T
2 is then in the cut-off state.

A cam, indicated at 31 and rotating together with the crankshaft 24, presses the switch arm 32 associated therewith against the force of the return spring against a counter contact connected to the positive pole 26, thereby connecting it to the positive conductor 26 up to this point. When connecting the negatively charged electrode of the control capacitor 33, which has been charged through the resistor 35 connected to the resistor 34 and the negative wire 29, to the positive conductor, the instability that determines the opening duration of the solenoid valve 13 is established. The relaxation oscillation process of the relaxation oscillator is started.

As a result, the transistor T1 is switched off, the transistor T2 and also the output transistor 21 are rendered conductive, and the solenoid valve 13 is opened.

The solenoid valve consists of monostable relaxation oscillator transistors T and T.
2 closes again when it returns to its initial state.

This point in time is determined by the inductance of the primary winding 37, which is inserted into the collector circuit of the transistor T2 and forms, together with the secondary winding 38 and the displaceable core 39, a transformer.

The iron core 39 is connected via a rod 40 to the membrane of a pressure chamber 41, which is connected to the suction pipe immediately in the suction direction of a throttle valve 48 which can be actuated by the gas pedal 36 and which reduces the inductance. The lower the absolute pressure in the suction pipe, the more this iron core is pulled out from between the primary and secondary windings.

One end of the winding of the secondary winding 38 is connected to the base of the transistor T1 via the diode 45, and the other end is connected to the positive conductor 26.
and two resistors 43 connected between the negative conductor 29 and
．． It is connected to 44 connection points.

As soon as the switch arm 32 contacts the counter contact and interrupts the transistor T1 via the diode 42, the transistor T2 supplies a current flowing through the primary winding 37, which increases at a rate inversely proportional to the inductance. 2
In the next winding 38, a transistor T2 is placed in the switch arm 32.
It induces a voltage that remains conductive regardless of the subsequent position of the primary winding 37 and until the current in the primary winding 37 reaches approximately a saturation value.

The induced voltage that cuts off the transistor T1 via the diode 45 becomes smaller as it approaches this saturation, and finally becomes negative when the transistor T1 set by the resistor 43.
The bias voltage of 1 becomes dominant and decreases until it returns transistor T1 to its initial conductive state.

When transistor T1 returns to conduction, output transistor 21 is cut off and the injection process is completed.

Various electronic compensation elements, not shown in FIG. 1, ensure that in all operating states of the internal combustion engine 10 at operating temperature, the amount of fuel previously introduced into the intake valve of the internal combustion engine during the individual injection strokes can be adjusted in the subsequent operating strokes. Complete combustion is achieved with virtually no excess air.

When the internal combustion engine is started from a cold state, it is necessary to additionally introduce air into the internal combustion engine so that it does not pass past the closed throttle valve in the no-load rotational position and the internal combustion engine stalls.

This secondary air quantity is indicated at 50 in FIG. 1 and is regulated in a time- and temperature-dependent manner by means of a secondary air valve, detailed below, while the additional fuel quantity belonging to the secondary air is regulated by a control device, not shown. The adjustment is made by means of a compensation element belonging to 25.

The secondary air valve forms a bypass with two air conduits 51 and 52 for bypassing the throttle valve which is closed during idle rotation.

Furthermore, the first conduit 51 is connected to the suction pipe 12 after the air filter 53 but before the throttle valve 48 in the suction direction.

The second air conduit 52 directs the secondary air to the suction pipe 1 immediately after the throttle valve.
2. Introduce it into the middle of the day.

In all the embodiments shown, the secondary air valves 50 are eccentrically arranged and pivotable about an axis formed by a bearing shaft 56, so that during their pivoting movement they are arranged coaxially with each other and spaced apart from each other. It has a vane member 55 used as a valve member that more or less opens or closes the inner diameter cross-sectional area of the air conduits 51 and 52.

An air conduit 52 which is connected behind the throttle valve and which can be connected to the suction pipe by means of a rubber hose (not shown) is integrally connected to a housing 57 having a neck 58.

A longitudinally extending bimetallic spring 60 is incorporated into the neck 58 , and the bimetallic spring is embedded in a plug 61 pushed into the neck 58 .

In two offset planes facing and parallel to the bimetallic spring 60, the plug 61 has two connecting pieces, one of which is indicated at 62 in FIG.

This is connected to one end of the heating coil 64, and the other end is connected to a second plug piece (not shown).

The free end 65 of the bimetallic spring 60 has a short lever protrusion 66
comes into contact with.

The lever protrusion is thus cut by punching out the blade member 55.

The vane members are shown in solid lines for clarity.

The tension spring 67 causes the blade member 55 to move as shown in FIG.
The lever protrusion 66 is rotated counterclockwise until it abuts the bimetallic spring 60.

When the heating coil 64 is energized and heat is applied to the bimetallic spring, its free end 65 presses against the projection and at the same time pushes against the vane member 5.
5 in the same direction with the spring force, therefore clockwise.

As a result, the vane member 55 has an increasingly smaller flow cross-section bounded by the opening 68, and the secondary air decreases towards zero until the normal engine operating temperature is reached.

For adjusting the size of the flow cross section, a support plate 70 is rotatably arranged on a concentric collar 71 on the air conduit 52 and has a bearing shaft 56 inserted for the vane element 55. It is provided.

The support plate 70 has a lever 72 extending laterally and a safety screw 7.
4 has a long hole 73 passing through it.

With this screw loosened, the support plate can pivot within the slot, and is fixed by tightening this screw.

This results in easy adjustment and control possibilities for the vane element 55 and the bimetallic spring 60.

The secondary air valve has a housing cover 75 deep-drawn from sheet steel, into which the air conduit 51 is inserted.

At its outer edge, the shoulder surface 76 of the cover covers the housing 57
It rests on a flange-like edge 77 of and is secured thereto by an edge region 78.

The mass of the blade member 55 and the bimetal spring 60 is the same as that of the support shaft 5.
6 is sufficiently included.

In the embodiment according to FIGS. 2 and 3, the vane member 55 in the closed position is moved by a narrow packing grip running along the opening 68 on the front side of the support plate 70 by means of the suction pipe negative pressure acting from the second air conduit. 79, so that the blocking effect is further enhanced.

In order to avoid lateral deflection of the vane member 55, arcuate guide ribs 80 and 81, shown in broken lines in FIG. 3, are additionally provided.

This is located on the same plane as the packing grip 79.

The flow cross-sectional area between both air conduits 51 and 52 is the same as that of the blade member 5.
It is determined by the outline of the window 83 punched out from 5.

When the bimetallic spring 60 is not heated and at the same time at a low temperature, the window is located on the inner diameter cross-section of both conduits 51 and 52, but as the bimetallic spring increases in heating and deflects, it moves out of the area of the air conduit. It is configured to reduce the amount of air passing through the air.

The variation of the window profile as a function of the window shape and the swivel angle of the vane element 55 differs for the individual construction of the internal combustion engine, but is very precisely defined for internal combustion engines of the same construction type;
Further, by adjusting the support plate 70, the amount of secondary air can be adjusted accurately.

A good airtightness of the interior space surrounded by the housing 57 and by the housing cover 75 is particularly important in order to maintain the set values over long operating times.

As a result of the severe temperature changes during operation of the internal combustion engine, the pressure-tight connection between the plug 61 and the housing neck 58 is particularly very compromised.

The plug is made of glass fiber reinforced polyamide to maintain a low coefficient of thermal expansion of about 20-30.

Additionally, an axial groove 84 is provided.

In this groove, the O-shaped lathed end 85 of the casing neck 58 is placed, and when the temperature rises, the cylindrical portion 86 of the plug 61, which expands more sharply, comes into strong surface pressure contact with the opening wall of the casing neck. None, while at temperatures below ambient temperature the edge 87
are inserted into a tight radial fit so that the ends are tightened on end 85.

By technically modifying the embodiment described, an arrangement can be made in which as the temperature increases, the contact pressure of the bimetallic spring increases and the return spring 67 acts more strongly.

[Brief explanation of the drawing]

Fig. 1 is an overview of the fuel injection system, Fig. 2 is a vertical cross-sectional view of the first embodiment of the secondary air valve, and Fig. 3 is a cross-sectional view taken along line 1-11I in Fig. 2. be. 10... Internal combustion engine, 11... Spark plug,
12...Intake pipe, 13...Injection valve, 1
5...Distributor, 16...Electromagnetic drive pump, 17...Pressure regulator, 18...Fuel tank, 21...Output Transistor, 22・
...Transistor amplifier device, 24...Crankshaft, 25...Relaxation oscillator, 28...
...Load resistance, 32...Switch arm, 33.
... Control capacitor, 36 ... Cas pedal, 37 ... Primary winding, 38 ... Secondary winding, 39 ... Iron core, 40... Rod, 41... Pressure chamber, 42, 45... Diode, 48... Throttle valve, 50...
Secondary air valve, 51°52...Air conduit, 57.
...housing, 58 ... neck, 60.
...bimetal spring, 61...plaque,
62... Connection piece, 64... Heating coil, 66... Lever protrusion, 68... Opening, 70... Adjustment plate, go , si...Guide rib, 83...Flow opening.

Claims (1)

[Scope of Claims] 1. An injection device, a throttle valve disposed in an intake pipe, and 2.
A secondary air valve is provided, which is arranged in the bypass passage around the throttle valve and which adjusts the passage cross-section of the bypass passage in a temperature-dependent manner. In a compressing internal combustion engine, the secondary air valve includes a vane member 5 having a window-like passage opening 83.
5, the vane member being swingable about an axis 56 by means of a bimetallic spring 60 which can be heated by at least one electric heating element, and facing each other at a distance during the swinging movement and having a bypass passage. at least partially covers the cross section of the two air guide channels 51.52.107 belonging to the vane element 55, at least in the closed position, the vane element 55 in the direction of the secondary air flow.
A packing lip 7 surrounding the air guide passage downstream of 5
9. Electrically controlled fuel injection device with secondary air valve, characterized in that it is in close contact with 9.