US3015326A

US3015326A - Control arrangement for fuel injection devices

Info

Publication number: US3015326A
Application number: US802912A
Authority: US
Inventors: Robert J Wirsching; Conrad Ulrich
Original assignee: Daimler Benz AG
Current assignee: Daimler Benz AG
Priority date: 1958-04-12
Filing date: 1959-03-30
Publication date: 1962-01-02
Anticipated expiration: 1979-01-02

Description

Jan. 2, 1962 R. J. WIRSCHING ETAL 3,015,326

CONTROL ARRANGEMENT FOR FUEL INJECTION DEVICES Filed March 30, 1959 PUMP P/sm/v TEMPE RH TUBE ZESPONS/VE TEMPE/PH TUBE EESPONS/VE 'll/III/IIII/I/l/IIIII/IA IIIIIIIIIIIIIIIIIII C001. 1N6 WA 7' EH INVENTORS ROBERT J. WIRSCHING ULRICH CONRAD w @1 1 wza wm ATTOR YS R071? 7'! UNA SP'EP EESPONSIVE l THR a T TL E United States Patent 3,015,326 CQNTRQL ARRANGEMENT FOR FUEL INJECTION DEVICES Robert I. Wh'sching, Korntal, near Stuttgart,

Conrad, Ludwigsburg-Ossweil, Germany, Daimler-Benz Alrtiengeselischaft, heim, Germany Filed Mar. 36, 1959, Ser. No. 802,912 Claims priority, application Germany Apr. 12, 1958 15 Claims. (Cl. 123-440) The present invention relates to a control arrangement for the fuel injection quantity of fuel injection pumps, especially of mixture-compressing internal combustion engines of the injection-type, which adjusts automatically the injection quantity of the fuel, in addition to an automatic adjustment in dependence on the rotational speed and on the throttle valve position, also in dependance on the air pressure, on the air temperature, and on the cooling-water temperature.

The present invention is concerned with the problem to improve such a control arrangement and to complete the same so as to perform its intended function in a more reliable and appropriate manner. Additionally, the present invention seeks to provide a continuous correction over the entire control range in dependence on the prevailing air density.

The present invention is characterized essentially by a double-armed pivotal lever operative to transmit the control magnitudes, the pivot point or axis of rotation of which is automatically adjusted by a cooling-water temperature sensing device and by one or several barometric pressure boxes as well as by an air-temperature sensing device whereby the transmission ratio of the two arms of the double-armed lever changes in dependence on the prevailing air density.

According to the adjusting and control principle of the present invention, it is possible to undertake an accurate metering of the injected fuel quantity in dependence on the rotational speed, on the throttle valve position as well as on the cooling-water temperature, the air temperature and the barometric condition. Furthermore, it is achieved in connection with an arrangement in accordance with the present invention that the forces within the lever mechanism of the control arrangement are effective only in one direction, i.e., are effective only unilaterally. The individual members thereby all abut unilaterally at the places of connections thereof so that no play can occur which would impair the accuracy of the operation of the control arrangement in accordance with the present invention. Furthermore, the accessibility for the assembly and the fine adjustment of the control arrangement is considerably improved by the present invention.

in a particularly appropriate arrangement of the present invention, the double-armed lever may cooperate with a three-dimensional cam member of known suitable construction which is adapted to be both axially displaced and rotated under the influence of the throttle valve position and the rotational speed respectively. It is significant thereby for the present invention that one of the lever arms of the double-armed lever which is constructed as sensing lever is adjusted by the three-dimensional cam member, and that the other end of the double-armed lever adjusts or displaces the control rack of the injection pump and that the pivot point or axis of rotation of the doublearmed lever is adjustable approximately perpendicularly to the longitudinal direction of the lever under the influence of a cooling-water sensing device and that simultaneously therewith the pivot axis of the double-armed lever is adjustable in the longitudinal direction thereof to thereby effectively vary the transmission ration of the lever, under the influence of the air temperature sensing and Ulrich assignors to tuttgart-Unterturk- 7 3,015,326 Patented Jan. 2, 1962 device and of the barometric pressure boxes, i.e., under the influence of the air density.

A further advantage is achieved in connection with the control arrangement according to the present invention by enabling a percentagewise correction in dependence on the air density over the entire control range thereof with an engine operating under normal hot running conditions, i.e., at normal operating temperatures. With a setting of zero-fuel supply and an engine at normal operating temperature, the control magnitude derived from the air density is no longer fuel pump.

The percentage correction is achieved by means of elongated or oblong apertures in the sensing lever and in the flattened end of the slide member which, with a setting of zero-fuel supply and the position thereof corresponding to the temperature of the normally operating engine are disposed coincidental one above the other so that both of these apertures coincide. The coinciding elongated apertures then form the ineffectual guidance for a connecting shackle or lug which transmits to the doublearmed sensing lever the control magnitudes of the air density in the other positions.

Accordingly, is is an object of the present invention to provide a control arrangement for injection-type mixturecompressing internal combustion engines in which the control of the fuel injection quantity is automatically controlled in dependence, not only on the rotational speed of the engine and on the position of the throttle valve, but also in dependence on the air pressure, on the air temperature and the cooling-water temperature.

Still another object of the present invention is the provision of a control arrangement automatically adjusting the amount of injected fuel in an automatic manner in dependence on the engine speed, the throttle valve position, the air density and the cooling water temperature of the engine.

Still a further object of the present invention is to provide a control arrangement of the type described hereinabove for automatically adjusting the amount of injected fuel in a continuous manner over the entire control range in dependence on the prevailing atmospheric conditions, especially the density thereof.

Still another object of the present invention resides in the provision of a control arrangement automatically adjusting the quantity of injected fuel in dependence on the rotational speed, the throttle valve position, the air temperature, the air pressure and the cooling-water temperature, in which any play in the control arrangement is essentially eliminated thereby improving the operation condition and the accuracy of operation thereof.

A further object of the present invention resides in the provision of a control arrangement for automatically controlling the amount of injected fuel in injection-type mixture-compressing internal combustion engines which facilitates assembly, repair and fine adjustment of the contIOi arrangement.

These and other objects, features and advantages of the present invention will become more obvious from the following description, when taken in connection with the accompanying drawing, which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIGURE 1 is a schematic view, partly in cross section, of portions of the control arrangement in accordance with the present invention, and

FIGURE 2 is a part perspective, part sectional view on an enlarged scale, of the central part of the lever mechanism for transmitting and coordinating the individual control magnitudes, and of elements of the control arrangement not illustrated in FIGURE 1.

Referring now to the drawing wherein like reference transmitted to the control rack of the this type of sensing ing device 1, which is connected to any conventional temperature responsive device in the cooling water cir-- cuit, the air temperature sensing device 2, which is connected to a temperature responsive device in the air intake, and three barometric pressure boxes 3 belong to devices which are illustrated in FIG URE 1. Additional control magnitudes are transmitted by the three-dimensional cam member 4 to the lever mechanism as illustrated in FIGURE 2 as will be discussed hereinafter.

The lever mechanism itself which serves for purposes of transmitting the individual control magnitudes and coordinating the magnitudes into a single adjusting magnitude for the control rack of the injection pump consists of a pivot lever 5 which is pivotally supported essentially in the center thereof on an eccentric bolt member 6. A further lever 7 is secured at the bolt member 6 which itself is actuated by the air-temperature sensing device 2. The pivot lever 5 is operatively connected over a servo device or amplifier 8 of suitable construction with an angle lever or bell crank 9. The connecting shackle or lug 10 is operatively connected with the bell crank 9 at one end thereof and carries at the other end thereof the bolt member 11 which is disposed within the two elongated apertures 12 and the elongated aperture 13 (FIGURE 2) of the fork-shaped double-armed sensing lever 14 and of the flattened end 15 of the slide member or plunger 16 respectively. The slide or plunger member 16 is operatively connected over a pivot lever 17 with the cooling-water-temperature sensing device 1. For purposes of clarity of FIGURE 1, the two elongated apertures 12 and the elongated aperture 13 in the doublearmed sensing lever 14 and the flattened end 15 of the slide member 16 are shown only in FIGURE 2. The double-armed sensing lever 14 includes at one end thereof the sensing roller or follower 18 which is in continuous engagement with the three-dimensional cam member 4 and is thereby adjusted during any rotary or axial movement of the latter. A drag-lever 19 is pivotally secured to this same end of the sensing lever 14 which drag-lever 19 is pivotally connected at the other end thereof with the control housing and is operative to secure the sensing device 14 against longitudinal displacement. At the other end of the sensing lever 14, i.e., at the end thereof opposite the sensing roller 18, the lever 14 acts on the control rack 20, of the injection pump (not shown) with the resulting adjusting control magnitude.

Operation The control arrangement in accordance with the present invention operates as follows: As shown in FIG- URE 2, the three-dimensional member 4 is axially displaced in the direction of double arrow 21 in dependence on the throttle valve position and is rotated in the direction of double arrow 22 under the influence of the rotational speed. Both. of these movements, namely the axially and rotary displacement of the cam member 4 may be achieved in any suitable, conventional manner known in the prior art. For example, the rotational speed control means may include crankshaft speed responsive means, and suitable means to rotate the three dimensional cam member 4. The means for axially displacing the cam member 4 may include cable means connected at one end to the member 4 and at the other end to lever means responsive to the positions of the throttle valve. By the movements of the three-dimensional cam member 4 under the influence of the throttle valve position and the rotational speed, the sensing roller 18 is adjusted in the direction of the double arrow 23 (FIGURES l and 2). The movements of the roller member 13 are transmitted over the sensing lever 14 to the control rack 20 against or in the direction of the force of a spring corresponding to the direction of the double arrow 24 and depending on the direction of the actual adjustment. The cooling-Water temperature sensing device 1 adjusts simultaneously the pivot lever 17 by reason of the change in the length thereof, i.e., in the longitudinal direction thereof. The cooling-water temperature sensing device 1 may thereby be of any conventional construction which translates changes in the temperature of the cooling water into longitudinal movements of a mechanical member. The slide member or plunger 16 is thereupon actuated by the pivot lever 17 and transmits the mov ments corresponding to variations in the cooling water temperature to the sensing lever 14. The particular manner of transmission thereof will be described more fully hereinafter with reference to FIGURE 2.

The control magnitudes of the air temperature sensing device 2 and of the barometric pressures boxes 3 translated into longitudinal changes or displacement by the sensing devices 2 and 3 are each transmitted to the doublearmed pivot lever 5, and more particularly in such a manner that the two-armed pivot lever 5 is pivoted at one arm thereof over an adjusting screw 25 by the barometric pressure boxes 3 and that the eccentric bolt member 6 which serves as bearing support for the pivot lever 5 is rotated over lever 7 by the air-temperature sensing device 2 in the direction of the double arrow 26. The resulting adjusting magnitude of the two-armed pivot lever 5 is transmitted to the servo device 8, whereby the servo device or amplifier 8 serves the purpose to amplify the control magnitude applied thereto by the pivot lever 5 and to transmit the thus amplified control magnitude to the angle lever 9. On the other hand, prevent that any reverse or retrograde adjusting forces which act on the servo device 8 in the direction from angle lever 9 are transmitted on to the pivot lever 5. The special construction of the servo device 8 and the arrangement of the eccentric shaft 6 and of the lever 7 make possible to achieve that the barometric pressure boxes 3 are loaded or acted on by a far-reachingly constant and relatively slight force which benefits to a large extent the measuring accuracy thereof. The small spring 27 of the servo device 8 abuts at the left end thereof, as seen in FIGURE 1, against stop member 28 which is rigidly connected with the sleeve 29. The other end of the spring 27 is supported over the control piston 30 and pivot lever 5 against the barometric pressure boxes 3. By reason of this particular construction of the servo device 8, it is possible to realize a spring force or spring tension exerted on the barometric pressure boxes 3 which remains essentia ly constant throughout. The angle lever or bell-crank 9 effects an adjustment of the connecting lug or shackle 10. The connecting lug or shackle 10 is provided at the end thereof remote from the angle lever 9 with a bolt member 11 which extends through both elongated apertures 12 and through the elongated aperture 13 (FIG- URE 2) in sensing lever 14 and in the flattened end 15 of plunger or slide member 16.

By reason of the fact that the sensing lever 14 is constructed in a fork-like manner, as shown particularly in FIGURE 2, and by reason of the fact that two arms of the fork thereof form two essentially fiat parts disposed fective in that connection as connecting bolt, and by reason of the fact that the connecting lug or shackle is also constructed in a fork-like manner the arms of which extend up to the region of the sliding head portion and of the center of the sensing lever 14 and are connected thereat with each other, as already mentioned, by means of the bolt member 11, the present invention achieves a control system in which the control magnitudes of the air density which are derived from the air temperature sensing device 2 and the barometric pressure boxes 3, and which are transmitted by the connecting lug or shackle 10, lead to a variation of the transmission ratio of the two arms of the double-armed sensing lever 14. The bolt member 11 thereby moves within the

elongated apertures

12 and 13. Since the bolt member 11 simultaneously therewith also represents the pivot point or axis of rotation of the double-armed lever 14, the two arms of the sensing lever 14 are respectively shortened or lengthened whereby the aforementioned change in the transmission ratio of lever 14 is achieved. Simultaneously therewith, the bolt member 11, and therewith also the sensing lever 14, is adjusted by the movement of the sliding member or plunger 16.

The movements of the sliding member or plunger 16 are directed essentially perpendicularly to the longitudinal direction of the doublearmed lever 14 which has as a result the fact that the transmission ratio of the doublearmed lever 14 is essentially unafiected by the movements of the siding or plunger member 16, i.e., by the control magnitude of the cooling-water sensing device 1. The transmission ratio is essentially adjusted only by the movements of the connecting lug or shackle 1t), i.e., of the bolt member 11, in the longitudinal direction of the double-armed connecting lever 14. The transmission ratio is, therefore, primarily dependent on the prevailing air density. As a result thereof, a correction over the entire control range in dependence on the prevailing air density is provided by the control arrangement in accordance with the present invention.

The

elongated apertures

12 and 13 in the plate-shaped sliding head member 15 and in the sensing lever 14 respectively are so arranged and constructed that with a zero-fuel supply adjustment and with normal operating temperatures of the engine they come to lie above one another in a substantially co-incidental manner. This position is shown in FIGURE 2. In this position, the bolt member 11 moves Within the

apertures

12 and 13 without causing any displacement or adjustment of the sensing lever 14.

While we have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of many changes and modifications within the spirit and scope of the present invention and we, therefore, do not wish to be limited to the specific details described and shown herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A control arrangement for controlling the fuel injection quantity, particularly of mixture-compressing injection-type internal combustion engines comprising first means for adjusting the quantity of injected fuel, second means for producing a control magnitude in response to the rotational speed of the engine, third means for producing a control magnitude in dependence on the engine control throttle position, fourth means for producing a control magnitude in dependence on the air pressure, fifth means for producing a control magnitude in dependence on the air temperature, sixth means for producing a control magnitude in dependence on the cooling-water temperature, and seventh means for transmitting the control magnitudes from said second, third, fourth, fifth and sixth means to said first means to provide a continuous correction over the entire control range in dependence on the prevailing air density including a double armed pivot lever means transmitting the control magnitudes and having a movable pivot means, and means for displacing said pivot means by any one of said sixth means, fifth means and fourth means, the transmission ratio of the two arms of said double-armed lever means being adjustable in dependence on the prevailing air density.

2. A control arrangement according to claim 1, wherein said first means is constituted by the adjusting rack of the injection pump, said double-armed lever means constituting a sensing lever, three-dimensional cam means con trolled by said second and third means and operatively connected with one arm of said double-armed lever means, and the other arm of said double-armed lever means being operatively connected with said adjusting rack to selectively adjust the latter.

3. A control arrangement according to claim 1, wherein said pivot means is so arranged as to be displaceable by said sixth means in a direction essentially perpendicularly to the longitudinal direction of said double-armed lever means, and wherein said pivot means is operative to be adjusted essentially in said longitudinal direction by said fourth and fifth means to thereby vary the lever ratio of said double-armed lever means.

4. A control arrangement according to claim 3, wherein said sixth means includes a sliding member provided with an elongated aperture in the free end thereof, said doublearmed lever means also being provided with aperture means so arranged as to coincide with said aperture in the respective positions thereof corresponding to a setting of zero-fuel supply and under normal engine operating temperature conditions to thereby render ineffectual the control magnitudes on said double-armed lever from said fourth and fifth means.

5. A control arrangement according to claim 4, further comprising connecting means pivotally secured at one end t ereof to said double-armed lever means and said sliding member by said pivot means engaging said aperture and said aperture means and operatively connected to said fourth and fifth means at the other end thereof.

6. A control arrangement according to claim 1, further comprising drag-lever means pivotally secured at one end thereof with said double-armed lever means and, at the other end thereof, with the control housing to prevent longitudinal displacement of said double-armed lever means.

7. A control arrangement according to claim 6, wherein said double-armed lever means constitutes the sensing lever and is constructed in a fork-like manner including two arm portions of the fork forming flattened parts disposed one above the other at a predetermined distance, a three-dimensional cam member operatively connected with said second and third means to provide a spatial displacement upon axial and rotational movements thereof corresponding to the control magnitudes derived from said second and third means, a cam-follower roller abutting against said three-dimensional cam member and accommodated within said two arms and pivotally secured therein, said sixth means including a sliding member provided with a flattened end portion surrounded on both sides thereof by said two arm portions of said fork-shaped, double-armed lever means within the central region thereof, said flattened end portion being provided with an elongated aperture cooperating with the apertures provided in said two arm portions of said double-armed, forkshaped lever means through said pivot means, said doublearmed lever means being provided at the free end thereof with abutment means for engagement with the springloaded end of the control rack formed by said first means constituting the injection pump.

8. A control arrangement according to clairn 7, wherein said drag lever means is also fork-shaped and is pivotally secured with said double-armed lever means at the pivotal connection thereof with said cam follower roller.

9. A control arrangement according to claim 8, further comprising a fork-shaped connecting shackle operatively connected at one end thereof with said fourth and fifth means, the arms of said fork-shaped connecting shackle extending up to the region of said sliding member and the center portion of said doube-armed lever means and being connected thereat by said pivot means extending through said elongated apertures.

10. A control arrangement for controlling the fuel injection quantity, particularly of mixture-compressing injection-type internal combustion engines, comprising first means for adjusting the quantity of injected fuel, second means for producing a control magnitude in response to the rotational speed, third means for producing a control magnitude in dependence on the engine throttle position, fourth means for producing a control magnitude in dependence on the air pressure, fifth means for producing a control magnitude in dependence on the air temperatu're, sixth means for producing a control magnitude in dependence on the cooling-water temperature, and seventh means for transmitting the control magnitudes from said second, third, fourth, fifth and sixth means to said first means to provide a continuous correction over the entire control range in dependence on the prevailing air density, said fourth means including barometric pressure box means and said fifth means including an air-temperature sensing means, a common pivot lever, means transmitting the control magnitudes from said barometric pressure box means and said air-temperature sensing means to said common pivot lever, servo amplifier means having input means and output means, means for applying the control magnitudes from said common pivot lever to the input means of said servo amplifier means, and means for applying the amplified control magnitudes from the output means of said servo amplifier means to said seventh means, said servo amplifier means including means protecting said barometric pressure box means against retrograde loads.

11. A control arrangement according to claim 10, wherein said last means includes a sleeve member in said servo amplifier means displaced by pressure, a spring within said sleeve member, an abutment in said sleeve rigidly connected therewith, and a control piston member operatively connected with said barometric pressure box means, said spring abutting at one end against said abutment and at the other end thereof against said control piston memher.

12. A control arrangement for automatically controlling the injected fuel quantity, especially of mixture-compressinginjection-type internal combustion engines in which the injected fuel quantity is automatically controlled, inaddition to a control in dependence on the rotational speed and the engine throttle valve position, also in dependence on the air pressure, the air temperature and the engine cooling medium and which produces a continuous correction over the entire control range in dependence on the prevailing air density comprising adjusting-meansfor selectively varying the amount of injected fuel, double-armed pivotal lever means transmitting the displacements corresponding to the respective control magnitudes to said fuel adjusting means including adjustable pivot means, means for adjusting said pivot means in response to said engine cooling medium, and sensing means responsive to the air density for varying the transmission ratio of the two arms of said double-armed lever means in dependence on the prevailing air density.

13. A control arrangement according to claim 12, wherein said sensing means responsive to the air density for varying the transmission ratio of the two arms is inefiectual to change the position of said lever means with the first means adjusted to zero-fuel supply and under normal operating temperature conditions of said engine.

14. A control arrangement according to claim 13, wherein said sixth means is ineffectual to vary the transmission ratio of said double-armed lever means with said first means adjusted to zero-fuel position and with said temperature operating under normal running conditions.

15. A control arrangement according to claim 12, wherein said sensing means includes servo amplifier means preventing retrograde loads from said lever means to said air density sensing means to thereby protect the latter against varying forces.

References Cited in the file of this patent UNITED STATES PATENTS