DE2047470A1 - Carburetors for internal combustion engines - Google Patents

Description

Patent application

Carburetors for internal combustion engines

The invention relates to a carburetor for internal combustion engines with a throttle valve arranged in the intake duct.

The increasing number of vehicles powered by the engine of a motor vehicle Additional units mean that even when the internal combustion engine is idling, torques of different magnitudes from the drive machine must be submitted. In known arrangements, the procedure has hitherto been such that the idling speed fluctuates within a relatively wide range Interval was accepted. In known arrangements, for example, the idle speed, which is normally 900 rpm, is reduced to less than 500 rpm. starting when an automatic transmission and various accessories such as an air conditioning system or the pump of a power steering system can be put into operation. It has already been proposed to do so with individual control systems to connect the larger accessories, such as the air conditioning system, so that when these units are switched on, the idle speed is influenced will. These individual systems, which also usually have an opening of the throttle valve effect, but are not applicable as the number of accessories increases. In addition, through these units a fixed adjustment of the Throttle valve is made so that this adjustment does not also go through

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other accessories, the load on the engine or the atmospheric conditions can be influenced.

Accordingly, the aim of the invention is to propose a better device, by the idle speed of the internal combustion engine regardless of which accessory units are switched on, within a narrow area can be kept constant. In addition, there is the promotion regarding the limitation of the emission of the internal combustion engine makes it necessary that the throttle valve is opened somewhat during the deceleration of the vehicle. This effect can also be achieved by the device according to the invention.

The aim of the invention is achieved in that a speed large device is provided for the speed of the internal combustion engine, with an operative connection between the speed measuring device and the throttle valve. inden is such that when the idling speed of the engine drops, for example due to a greater load on the same by opening the throttle valve, the idling speed can be regulated to a value within a limited interval.

The throttle valve can be fitted with a cam rod on a control surface be connected sliding follower pin, wherein the cam rod is adjustable by an adjusting device.

According to the invention, the actuating device can counteract the action of a spring contain displaceable piston by generating a negative pressure, the piston rod of which is connected to the cam rod.

It is advantageous that the vacuum supplied to the actuating device, the Underpressure modulated by the engine speed in the intake manifold the internal combustion engine is.

In detail, the speed measuring device can be one of the internal combustion engine driven shaft exist, on which a centrifugal weight displaceable against the action of a spring at a radial distance from the central axis of the shaft is arranged on a bushing provided with an opening, the

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negative pressure fed through a channel in the shaft of the opening by the corresponding the speed can be throttled by the flyweight in the size variable opening and this negative pressure is fed to the actuating device.

Advantageously, the control surface has a V-shape, with normal The speed of the follower pin lies at the point of intersection of the two legs, while the throttle valve is evident when moving to both sides.

The channel is advantageously within the shaft of the speed measuring device with an opening that is directly on the lower edge of the throttle valve, connected, so that the negative pressure prevailing there is fed to the speed measuring device will.

In a further exemplary embodiment, the speed measuring device can consist of a With the internal combustion engine speed rotating and a magnetic portion containing shaft exist, in addition to the shaft, a magnet on a Hahnkern is arranged so that when changed according to the speed, by the shaft generated magnetic field the magnet is deflectable against the action of a tension spring and thus arranged in the valve core by rotation of the valve core Opening to different degrees can be brought to coincide with an opening located in a socket, as a result of which the opening is fed to the opening through a channel Negative pressure emerges from the opening in a throttled manner according to the speed.

In this case, too, the channel arranged in the rotational speed measuring device is included an opening located directly on the lower edge of the throttle valve.

A so-called lost motion connection can be created within the connection between the foot pedal and the throttle valve be arranged, the aim of which is the pressure of the follower pin on the control surface not by the existing return spring of the drive foot lever to get too big. When the vehicle is decelerating at relatively high speeds, the resulting negative pressure acts on the intake motor the adjusting device in such a way that the control surface is moved back. This also opens the throttle valve slightly, which reduces the situation with respect to the emission of the engine can be improved.

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The invention is explained on the basis of the exemplary embodiments shown in the figures.

Show it:

Figure 1

a schematic representation of the device according to the invention, where as RPM measuring device a flat weight device is used;

Figure 2

a cross section through the neck bar as used according to the invention will;

* Figure 3

a schematic representation of the connection of the drive foot lever with the others Devices of the carburetor according to the invention;

Figure 4

another embodiment of a speed measuring device according to the invention.

As can be seen in particular from FIG. 1, a carburetor has a total of 10 designated. The carburetor is connected in the usual way to an intake pipe (not shown) of an internal combustion engine. The carburetor 10 contains an intake passage 12 which is in communication with the intake pipe of the internal combustion engine; through it, air and fuel enter the engine's combustion chamber. A throttle valve 14 is rotatable in the inlet duct of the carburetor befc strengthens; it determines the amount of air fuel that gets to the engine, regulated.

A speed measuring device for measuring the speed of the internal combustion engine is denoted by 15 as a whole. This device contains a shaft 16 which is connected by the internal combustion engine within a small housing 18.

in
is driven. The shaft has a radially extending sleeve 20 which is attached to the upper end of the shaft and is rotatably seated within the housing 18. A channel 22 extends ³ axially through the shaft 16 and is in communication with a short channel 24, the opening of which points into the interior of the housing 18 through an opening 26 in the wall of the bushing 20. The other linden

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of the channel 22 is in communication with the inlet channel 12, namely at one Point that is just below the throttle in the closed position. A Flyweight 28 is slidably mounted on sleeve 20, with a spring 30 normally pushing the flyweight into a position in which it opens the opening 26 covers so that no connection "between the channel 24 and the interior of the housing 18 consists.

A line 32 connects the interior of the housing 18 with an adjusting device 34. The adjusting device 3 ^ contains a movable piston 36 which is spring-loaded _x by a spring 38 and which presses the piston to the left in the arrangement according to FIG. Line 32 contains an adjusting screw 40 which can be used to manually adjust the amount of pressure on the right side of piston J6.

The left side of the piston 36 is through a piston rod 42 with a cam rod 44 connected. The cam rod has a control surface 46 on one side; A follower pin 48 slides on this control surface is adjustable attached to a lever 50, which in turn connects to the throttle valve l4 is connected. As can be seen in particular from FIG. 2, the control surface is 46 V-shaped with a leg point on which the follower pin 48 is seated during normal operation or when the engine is idling without load. the calculated from this point on the left side of the control surface comes into effect when the vehicle decelerates, while the right side comes into effect when the engine is loaded while idling by switching on additional units. The right end of this area is the start-up production of the plant.

The function of the system, as shown in Figures 1 and 2 is as follows: When the internal combustion engine is not operating, atmospheric pressure prevails in the channel 22 and in the chamber on the right S g _e of the piston 36. The spring 38 moves characterized the cam bar 44 to the left in Figure 1 to a position where the stylus 48 contacts the control surface 46 at the starting point (see Figure 2) . n _{eP follower} pin 48 is connected to the throttle valve in such a way that when the engine is started the throttle valve is slightly above normal

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- 6 idle position is open, which results in good starting properties.

When the engine has started, a negative pressure appears in the channel 22. The Shaft 16 is driven accordingly by the motor. The flyweight 28 and the spring 30 are matched to the rotation of the shaft 16 that with a normal Speed of about 600 rpm. the Fliehgewicfet 28, .radial along the Socket 20 moves, βο that the opening 26 is exposed. This will make the im Channel 22 prevailing pressure changed accordingly, so that the pressure changed in this way in the housing 18 through the line 352 of the right chamber of the adjusting device 34 can be forwarded. The adjusting screw 4o is a further change of the pressure in the right chamber of the adjusting device is possible, so that the cam rod 44 can be adjusted by the piston 36, ^ That the follower pen touches the control surface exactly at the idle point.

to the idling internal combustion engine through the connection a unit is loaded, the engine speed drops. A corresponding A decrease in the speed causes a reduction in the number of revolutions of the shaft 15 and allows the spring 30 to move the flyweight 28 radially inward, so that the flyweight 28 covers a larger amount of the opening 26. The pressure signal, which is then sent to the right-hand side of the adjustment device 34 is passed is thereby changed and the spring 38 moves the cam rod 44 to the left. The follower pin 48 thus touches the control surface 46 at a point which causes the throttle valve 14 to open. The opening of the However, the throttle valve now has an increase in the torque output by the machine result, whereby the idling speed is increased and now P is not significantly below the normal speed for idling.

This ensures that when the torque output is increased by the engine the idling speed of the engine is essentially maintained and only insignificantly sinks. The control surface 46 can be designed so that it is for adjusts the throttle valve in the same way for all operating states and for switching on all accessory units and thus for the increase of the torque output at an only insignificantly reduced idling speed cares. In most applications, the arrangement can be made so that the drop in speed is less than 30-60 r.p.m. amounts to.

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Internal combustion engines that are not equipped with the system according to the invention are, on the other hand, show a decrease in speed by an amount of more than 500 rpm, under the same conditions.

When the internal combustion engine is accelerated, for example by the fact that the If the throttle valve is opened, the follower pin 48 leaves the control surface 46. An actuation of the carburetor in the normal operating range of the motor vehicle is not affected by the arrangement according to the invention.

If the engine is decelerated from a high speed, it becomes considerable Improvement of the conditions with regard to the emission achieved in that the throttle valve is held in a somewhat open position. This effect can be achieved by the arrangement according to the invention as follows. At engine speeds above idle speed, the flyweight moves 28 on the socket 20 radially outward so that the opening 26 is exposed. If the speed of the internal combustion engine is now reduced, occurs Relatively unmodulated amount of the pressure in the intake pipe through the opening 26 into the right chamber of the actuating device J54, this negative pressure din The cam rod 44 in the arrangement according to FIG. 1 is displaced to the right until the follower pin 48 touches the control surface 46 in the left-hand area. The tracer pen 48 thus acts on the lever 50 that the. v: r el., My Bcir-an, -'Je Throttle valve 14 opens. If the internal combustion engine reaches the normal idling speed, the increasing negative pressure in the intake manifold and the modulating effect on the pressure caused by the action of the unconcerned 28, if this slides over opening 26, slide cam rod 44 back to the point where follower pin 48 contacts control surface 46 when the position is to be taken for normal idling or if there is an idling in which, however, certain accessory units are switched on.

The lost motion connection shown in FIG. J5 connects the drive pedal of the motor vehicle with the throttle valve; this connection has the task of keeping the pressures exerted by the follower pin 48 on the control surface 46 as small as possible. As can be seen in particular from FIG. 3, the lever 50 is part of an L-shaped lever 52 which has a second arm 54. Ei _ne rod 56 is attached to the arm 54, this attachment

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takes place within an elongated hole 58 in a lever 60. The lever 60 is rotatable about an axis of rotation 62 attached to the housing of the carburetor. A tension spring 64 connects the lower end of the lever 16 to an attachment point 65. The upper part of the lever 60 is connected by a rod 66 to the drive foot lever. A tension spring 68 with a relatively small spring constant connects the arm 64 to a fastening point (not shown), so that the tension spring 68 normally moves lever 52 clockwise as shown in Figure J5. During normal driving of the vehicle, the rod 56 is on the right End of elongated hole 58. Depressing the foot lever pulls rod 66 to the left, so that rod 56 is held on the right side of elongated hole 58 where it remains during normal driving.

II When the drive foot lever is moved back, the lever 60 is clockwise below the influence of the tension spring 64 swung back. The tension spring 68 moves the Lever 62 clockwise so that follower pin 48 is in contact with the control surface 46 is held, whereby the rod 56 near the left end of the elongated hole 58 is held. When the speed of the internal combustion engine is in the normal idle range drops, the follower pin 48 moves to the normal position for the idle range or in the position for the loaded idle range correspond to the adjustment by the adjusting device 34. The tension spring 64 thus ensures that the throttle valve is returned to the idle position with a great deal of force, but this force is not caused by the Transfer stylus 48 to control surface 46.

Another embodiment of a speed measuring device is provided DAR ψ in Fig. 4 A ferromagnetic shaft 70 is driven via a conventional transmission by a rotating part of the internal combustion engine. O '.. e shaft 70 protrudes into a housing 72 in which at least one pair of ferromagnetic poles is arranged on the cylindrical circumference within the housing 72.

The housing 72 also includes a faucet core which extends axially Contains channel 76. The valve core 74 is shown in section in FIG it can be seen that the channel 76 does not protrude beyond the head of the cock core 74, but opens into the housing via a radially extending opening 78. One Bushing 80 surrounds the tap core 74, this bushing also being radial

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Has opening 82, which is arranged offset in the clockwise direction to the opening 78 is.

The opening 82 is in communication with the interior of the housing 70, the Channel 76 connected by a line 84 to the inlet channel 12 to the carburetor is, namely at a point which is just below the position at which the closed throttle valve rests on the housing wall of the carburetor. One end of an arm 86 is attached to the faucet core 74, while the other The end protrudes against the rotatable shaft 70. A magnet 88 is attached to the end of the arm 86, this magnet being in the vicinity of a magnetized portion of the Shaft 70 is arranged. A tension spring 90 connects the arm 86 to the wall of the housing.

While the internal combustion engine is running, the shaft rotates 70 counterclockwise a magnetic force on the arm 86, whereby the faucet core is rotated clockwise. A rotation of the cock core 74 takes place against the action of the tension spring 90, which is designed so that it allows a partial coverage of the openings 78 and 82 when the idle speed the internal combustion engine is complied with without a load being present. However, if there is a load while idling, a modulated one arrives Pressure from channel 76 through port 78 and port 82 into the interior of the housing 72 and from there to the actuating device j? 4. The further effect of this The adjusting device is then carried out as shown above.

A better adjustment of the facility to changes in the load can thereby be achieved that the channel 22 with the inlet channel 12 via an opening 92 takes place, which is arranged just below the edge 94 of the throttle valve 14 is. Larger pressure changes due to a change in the load on the internal combustion engine show up in this area, these changes being introduced directly into the present system and fed to piston 36, whereby a proportionally larger movement of the piston rod per speed unit of the internal combustion engine takes place than before.

Instead of the control surface shown here, a US-60 / September 9, 1970 - 10 -

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Control surface in the form of a cam can be used. The springs used within the speed measuring devices can also have a different shape without that the inventive idea is abandoned.

Through the subject matter of the invention, the idle speed of a ver

n internal combustion engine also kept within a narrow range when In this operating state there is a connection of to β atzaggregaten, which cause a load on the engine. The system according to the invention is relatively inexpensive and can be easily installed and maintained. In addition, this system improves the emissions of the internal combustion engine feasible if there is an improvement for the area of sudden delay of the motor vehicle is to be achieved.

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Claims (9)

Claims 1.j Carburettor for internal combustion engines with one arranged in the intake duct Throttle valve, characterized in that a speed measuring device (15) for the speed of the internal combustion engine is provided, whereby an operative connection between the speed measuring device (15) and the throttle valve (14) is present in such a way that when it drops the idling speed of the engine, for example due to greater load on the same, by opening the throttle valve (14), the idling speed to one Value can be regulated within a limited interval. 2. Carburetor according to claim 1, characterized in that the throttle valve (14) with one on a control surface (46) one Cam rod (44) sliding follower pin (48) is connected, wherein the cam rod (44) is adjustable by an adjusting device (34). 3 · Carburetor according to claim 2, characterized in, that the adjusting device (34) has a counter to the action of a spring (38) contains a piston (36) displaceable by generating a negative pressure, the piston rod (42) of which is connected to the cam rod (44). 4. Carburetor according to claim 1 to 3> characterized in that that the negative pressure supplied to the actuating device (34) is the same as that caused by the engine speed modulated negative pressure in the intake manifold of the internal combustion engine. 5. Carburetor according to claim 1 to 4, characterized in that that the Drehazahlmeßeinrichtung (15) from one of the internal combustion engine driven shaft (l6), on which at a radial distance from the central axis of the shaft (l6) a displaceable counter to the action of a spring (30) The flyweight (28) is arranged on a bushing (20) provided with an opening (26), the latter via a channel (22) in the shaft (l6) the vacuum supplied to the opening (26) can be throttled by the opening (26), which can be adjusted in size by the centrifugal weight (28) according to the speed and this negative pressure is fed to the actuating device (3 * 0. US-60 / September 9, 1970 - 2 - 10981 8/1287 6. Carburetor according to claim 1 to 5, characterized in that that the control surface (ft6) is V-shaped, with normal speed the follower pin (48) at the point of intersection of the two leg legs a movement to both sides the throttle valve is evident. 7. Carburetor according to claim 1 to 6, characterized in that that the channel (22) with an opening (92), which is immediately at the lower edge the throttle valve (14) is connected. 8. Carburetor according to 1 to k, characterized in that the speed measuring unit; consists of a shaft (70) rotating with the engine speed and containing a magnetized section, a magnet (88) being arranged on a cock core (7 ² O) next to the shaft, so that when the speed is changed according to the speed, the shaft (70) generated magnetic field, the magnet (88) can be deflected against the action of a tension spring (90) and thus, by rotating the tap core (7 ^), an opening (78) arranged in the tap core of different strengths to coincide with an opening (82) located in a socket (80) ) can be brought, as a result of which the negative pressure fed to the opening (78) through a channel (76) emerges from the opening (82) in a throttled manner corresponding to the speed. 9. Carburetor according to claim 8, characterized in that that the channel (76) is connected to an opening (92) which is located directly on the lower edge of the throttle valve (14). US 60 / September 9, 1970 109818/1287 Blank page