US2717805A - Fuel injection device for internal combustion engines, especially for motor vehicles - Google Patents

Description

Sept. 13, 1955 SE|FERT ETAL N DEVI ENGINES, ESPECIALLY FOR MOTOR VEH Flled Sept 15 1951 FUEL INJECTIO CE FOR INTERNAL COMBUSTION ICLES 2 Sheets-Sheet l VII/9 747! f INVENTORS:

RICHARD SE/FERT WALTER BART/7 ATTORNEK Se t. 13, 1955 R. SEIFERT ET AL 2,717,805 'FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES, ESPECIALLY FOR MOTOR VEHICLES 2 Sheets-Sheet 2 Filed Sept. 15, 1951 INVENTORS: RICHARD SE/FERT WALTER BART/7 Jay/(4m ATTORNEY.

United States Patent 'Ofiice 2,717,805 FUEL INJECTION DEVICE FOR RNTERNAL GOM- BUgIOIETSENGHVES, EPECIALLY FGR MOTQR VE CL Richard Seifert and Waiter Barth, Friedrichshafen, Germany, assignors to Karl Maybaeh, Friedrichshafen, Geimny Application September'- 15, 1951, Serial No. Ciaims priority,

246,782 application Germany September 16, 1950 3 Claims. (Cl. 299-107.2)

gine or after the adjustment linkage has been broken or taken apart in the course of maintenance work.

numerals refer to like and in which:

Fig. 1 is a View, partly in cross-section along line 1-1 of Fig. 2, of a fuel injection device according to our invention;

Fig. 2 is a plan view lever 20 and pusher 19 Fig. 3 is a view in Fig. 1; and

Fig. 4 is a view, similar to Fig. 1, of a modification of our invention.

Referring now to Figs. 1 to 3, acne-piece casing 1 has an upper portion 2 in which a transmission member or sleeve 3 is rotatably supported. A drive member in the form of a worm gear sleeve 4- is rotatable on sleeve 3 and rests on a flange 5 formed on sleeve 3. A ring 6 has an internal conical surface mating with an external conical surface on gear sleeve 4, and a nut 7 on sleeve 3 with lock washer 44 serves to press the ring 6 against the gear sleeve 4 and thereby clamp or lock the latter of the device of Fig. 1 With the removed; cross-section along line 33 of At the same serves to lock the adjustment.

A pump plunger or adjustment member 16 has a por- 2,717,805 Patented Sept. 13, 1955 plunger 16 without interfering with the square portion 15 being able to 16. 53 forces the roller 51 up, rocking the lever 20 and exerting a downward push against the plunger 16 through adjustment screw 18, pusher 19 and follower 17. When shown in Fig. 1. the distance between the lever 20 pusher 19,. i. e. of the upper and lower positions of plunger 16.

in the lower 22 communicates through a a groove 43 provided in a liner or cylinder 47 mounted" in casing 1. The outlet connection 23 communicates with a passage 29 which in turn communicates with bores 27 and 28- in liner 47.

which communicates with a groove 48 that is connected 24. The other end of passage 25 is chamber 26. The plunger groove 30 which is adapted to register with an annular channel 32 which communidevice to a cylinder measurement of the quantity of fuel discharged by nozzle 54' on each stroke of the plunger 16.

During the upward stroke of plunger'16, the ball check valve 38 opensand fuel from its source flows via connection: 22; passage 24, groove 48, passage 25, valve 38, and passages 39 into the pressure chamber 26. During the downward stroke of plunger 16, starting with the position shown in Fig. 1, the fuel. in chamber 26 at first escapes through bore 27 and passage 29 into the return connection 23 until the face 31 passes the lower edge of bore 27 which is thus closed by the plunger 16. At that instant, the injection of fuel through nozzle 54 begins as there is now no other escape for the fuel in pressure chamber 26. After some further downward movement of plunger 16, the helical groove 32 comes into register with groove 33, and this terminates the injection of fuel through nozzle 54, because the fuel in chamber 26 now can again escape to the return connection 23 via groove 33, helical groove 30, annular channel 32, bore 28 and passage 29.

During the up and down motions of plunger 16, the helical groove always remains in register with the annular channel 32. The point of the down-stroke at which the fuel injection is terminated when the helical groove 3% comes into register with groove 33 can be varied by rotating the plunger 16. Such rotation also affects, although to a much lesser extent, the time at which the injection of fuel starts, because of the inclination of face 31. Such inclination of the face 31 is not an essential feature of our invention. If desired, the face of the plunger may be made flat as shown in Fig. 4 (to be described later). If the face of plunger 16 is not inclined, the point of the down-stroke at which the fuel injection starts does not change on rotation of the piston.

In calibrating the device, it is placed on the test stand with the nut 7 and screws 43 loose. Next, the nut 7 is tightened to lock the gear sleeve 4 and transmission sleeve 3 together. Any rotation of gear sleeve 4 is now transmitted through transmission sleeve 3, pins sleeve 14 to the plunger 16. The plunger 16 is then so positioned by rotation of gear sleeve 4 that with a predetermined stroke a predetermined quantity of fuel, as, for instance, a desired maximum quantity of 300 cubic millimeters per stroke, is injected through nozzle 54. Then the markings 41 and 42 are brought into register, and the disc 4% is locked to casing 1 by tightening screws 43. When all fuel injection devices for a given engine have thus been similarly adjusted and calibrated for injection of the same quantity of fuel, they are removed from the test stand and mounted by means of clamps on the cylinder head 36. The gear sleeve 4 of each device is brought into mesh with worm 9 with the markings 41 and 42 in register with each other, so that the calibrated position determined on the test stand is re-established.

The nut 7 is left tight so that sleeves 3 and 4 remain locked together for joint rotatability.

During operation of the engine with the fuel injection devices in their calibrated positions, the rotation of shaft 52 with cam 53 causes each fuel pump each downward stroke the same basic quantity of fuel for which it was adjusted. Rotation of shaft 8, the actuating means for the adjustment device, causes all plungers to rotate through the same angle so that the increased or decreased quantity of fuel injected remains identical for 1 all cylinders of the engine.

In the modification shown in Fig. 4, a one-piece casing has on its upper portion 61 a transmission sleeve 62 rotatably supported. A transmission member in the form of a worm gear sleeve sleeve 62 and rests on flange 64. The worm gear 63 meshes with worm 65 on shaft 66 for actuation thereby.

A pump plunger or adjustment member 67 is adapted to be moved downward against the upward pressure of a spring 68 by a lever 69 acting through a pusher 70 and a follower "71 on the top of plunger 67.

The plunger 67 is movable in a liner or cylinder 72 and has an inlet passage 73 terminating in face 74 (and advantageously provided with a check valve such as valve 38 of Fig. l). The passage 73 registers with an annular channel 75 in communication with a fuel inlet passage 76. A fuel return passage 77 communicates through a passage 78 with a bore 79 leading to an annular channel 39 and with a bore 81. A pressure chamber 82 below plunger 67 communicates with a fuel injection nozzle 83.

13, and

to discharge during 63 is rotatable on transmission The plunger 67 has, furthermore, a helical groove 34 adapted to interconnect the annular channel 8% with a groove 85 in communication with pressure chamber 82.

For purposes of adjustment and calibration, the sleeve 62 has threaded thereon a lock nut 86 which may be tightened to lock the sleeve 63 to the sleeve 62 for joint rotatability, and the upper portion 61 of casing 60 has threaded thereon a lock nut 87 which may be tightened to lock the sleeve 62 to the casing 60.

To transmit rotation of sleeve 62 to the plunger 67, a transverse member is provided consisting of a sleeve 83 fitting over fiat surfaces 89 on plunger 67, and pins 90 extending through elongated openings 91 in casing 60 into grooves 92 in sleeve 62.

The casing 69 is mounted on cylinder head 93.

Gperaticn of the device shown in Fig. 4 is similar to that of Figs. 1 to 3. When the arm 69 moves up, the spring 68 lifts the plunger 67 causing fuel to how through inlet passage 76, channel 75, and passage 73 into the pressure chamber 82. When the arm 69 moves down, it depresses the plunger 67. Then fuel at first returns to its source via bore 31 and passages 73 and 77. When the face '74 passes the lower edge of bore 81, the injection of fuel through nozzle 83 begins and is terminated as soon as helical groove 84 interconnects groove $5 with annular channel 89 and thus allows the fuel to return through bore 7% and passages 78 and 77.

To initially adjust and calibrate the device of Fig. 4, it is placed on a test stand with lock nuts 86 and 87 loosened. desired quantity of fuel per stroke has been achieved, both lock nuts 86 and 37 are tightened. Upon transfer of the device to the engine and bringing worm 65 into mesh with worm gear 63, the lock nut 87 is loosened to permit free rotation of the plunger 67 by the actuating shaft 66 through sleeves 63 and 62 (the lock nut 86 remaining tightened), pins 90, and sleeve 88.

The device of Fig. 4 is somewhat simpler. The device of Figs. 1 to 3, on the other hand, has the advantage that the original setting can be readily re-established at any time by merely bringing markings 41 and 42 into register with each other, provided the calibrated adjustment of disc 49 on casing 1 has not been disturbed.

While we have shown and described what we consider the preferred embodiments of our invention, modifications other than those disclosed herein may be made without departing from its spirit, and reference is, therefore, made to the following claims for a definition of the scope of our invention.

What we claim is:

l. A fuel injection device for internal combustion engines comprising a fuel injection nozzle and a fuel pump having a casing, an adjustment member for said pump, a transmission member connected with said adjustment member for joint rotatability, a drive member adapted to actuate said transmission member, the position of said drive member relative to said transmission member being variable, means for locking said transmission member to said drive member, actuating means for said drive member, a disc adjustably mounted on said casing, a marking on said disc, and a marking on said transmission member, said two markings being arranged to register in the basic setting of said adjustment member.

2. A fuel injection device for internal combustion engines comprising a casing, a pump plunger axially movable and rotatable in said casing, a fuel injection nozzle at one end of said casing, an inclined face on said plunger at the end thereof facing said nozzle, a fuel conduit extending through said plunger and having an inlet at the side of the plunger and an outlet extending through said face, a fuel inlet port in said casing communicating with the inlet of said conduit, a fuel outlet port in said casing proximal of said nozzle, said outlet port being adapted to be closed by the end of said plunger facing When adjustment resulting in injection of the said nozzle, and adjustment means connected with said face on said drive member and a clamping ring having plunger for rotating the latter. a conical surface fitting on the conical surface of said drive 3. A fuel injection device for internal combustion member, and a lock nut screwed on said transmission engines comprising a fuel pump having a plunger, 21 casmember for pressing said conical surfaces against each ing for said pump, and adjustment means for said pump, 5 other. said adjustment means comprising, in combination, a transverse member axially movably connected with said References Cited in the file Of this Patent plunger and rotatable in said casing about the longitu- UNITED STATES PATENTS dinal axis of said plunger, a transmission member rotatable on and surrounding said casing and having a sur- 10 Keller 3 face portion adapted to abut against said transverse memh her for rotating said transverse member and said plunger 1854O09 Wflkmson 1932 upon rotation of said transmission member, a drive mem- 16 Gosslau Sept 1932 her for said transmission member, and clamping means 2222593 Hurst 1940 for clamping said drive member to said transmission 15 French July 1950 member, said clamping means comprising a conical sur- 2571501 Truxeu 1951

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