DE1526736C3

DE1526736C3 - Fuel rail injection pump

Info

Publication number: DE1526736C3
Application number: DE19661526736
Authority: DE
Inventors: Vernon Davis West Hartford Conn.(V.St.A.) Roosa
Original assignee: Stanadyne LLC
Current assignee: Stanadyne LLC
Priority date: 1965-11-01
Filing date: 1966-10-31
Publication date: 1976-08-19

Description

einstellbar ist. Er weist mehrere Paare diametral gegenüberliegender, nach innen gerichteter Nockenwölbungen 52 auf, die so angeordnet sind, daß die beiden Pumpenkolben 44 gleichzeitig nach innen gestoßen werden, wodurch die Pumpe Kraftstoff abgibt. Die auf Rollen 43 gelagerten Schuhe 46 stellen Rollenstößel dar, die zwischen den Pumpenkolben 44 und dem Nockenring 50 angeordnet sind und bei Drehung des Rotors dem Umrißverlauf der Innenfläche des Nockenringes folgen, wodurch ihre hin- und hergehende Bewegung auf die Pumpenkolben 44 übertragen wird. Der C-förmige Ring 56, der mit einer Befestigungsschraube 58 am Rotor angebracht ist (Fig. 2), stellt einen einstellbaren äußeren Anschlag für die Schuhe 46 dar. Zur Verhinderung der Leckage von Kraftstoff in oder aus dem Raum zwischen der Antriebswelle 60 und dem Gehäuse 10 ist eine Dichtung 62 vorgesehen.is adjustable. It has several pairs of diametrically opposed, inwardly directed cam lobes 52, which are arranged so that the two pump pistons 44 pushed inward at the same time causing the pump to deliver fuel. The shoes 46 mounted on rollers 43 represent roller tappets, which are arranged between the pump piston 44 and the cam ring 50 and when the rotor rotates follow the contour of the inner surface of the cam ring, causing its reciprocating motion is transmitted to the pump piston 44. The C-shaped ring 56, with a fastening screw 58 attached to the rotor (Fig. 2) provides an adjustable outer stop for the shoes 46. To prevent leakage of fuel into or out of the space between the drive shaft 60 and the Housing 10, a seal 62 is provided.

Wenn sich die Antriebswelle 60 dreht, werden die Flügelzellenpumpe 18 und die Einspritzpumpe 40 so gedreht, daß abgemessene Kraftstoffmengen unter Druck nacheinander an mehrere Einspritzleitungsanschlüsse 64 abgegeben werden, die mit Kraftstoffeinspritzdüsen eines Verbrennungsmotors in Verbindung stehen. Während des nach außen gerichteten oder Ansaughubes der Pumpenkolben 44 wird von einem Dosierkanal 41 durch einen im Gehäuse 10 befindlichen Kraftstoffzuführkanal 66 und eine im Rotor 14 diagonal verlaufende Kraftstoffzuführbohrung 68 Kraftstoff an den Pumpenarbeitsraum der Einspritzpumpe abgegeben. Während des nach innen gerichteten oder Druckhubes der Pumpenkolben 44 wird Kraftstoff unter hohem Druck durch eine Axialbohrung 76 an ein druckbetätigtes Abgabeventil 77 und eine im allgemeinen radial gerichtete Verteilerbohrung 78 geliefert, die so angelegt ist, daß sie hintereinander mit mehreren, einen gleichen Winkelabstand aufweisenden, radialen Kraftstoffabgabekanälen 63 und damit mit mehreren Einspritzleitungsanschlüssen 64 in Strömungsverbindung tritt. Ein Rückschlagventil 68a sperrt während des Druckhubes der Einspritzpumpe 40 den Rückfluß durch die Kraftstoffzuführbohrung 68.When the drive shaft 60 rotates, the vane pump 18 and the injection pump 40 become so rotated that metered amounts of fuel under pressure successively to several injection line connections 64, which are in connection with fuel injectors of an internal combustion engine stand. During the outward or suction stroke of the pump piston 44 is of a Metering channel 41 through a fuel supply channel 66 located in housing 10 and one in rotor 14 diagonally running fuel supply bore 68 fuel delivered to the pump working chamber of the injection pump. During the inward or pressure stroke of the pump piston 44, fuel is under high pressure through an axial bore 76 to a pressure actuated dispensing valve 77 and one in general supplied radially directed distributor bore 78, which is designed so that it is one behind the other with several, Equally angularly spaced, radial fuel delivery channels 63 and thus with several Injection line connections 64 enters into flow connection. A check valve 68a blocks during the The pressure stroke of the injection pump 40 controls the return flow through the fuel supply bore 68.

Der Rotor 14 erstreckt sich über die Stirnfläche 11 des Einspritzpumpengehäuses 10 hinaus und bildet hier den Nabenteil der Flügelzellenpumpe, der, wie in F i g. 3 gezeigt, zur Aufnahme federbelasteter Pumpenflügel 19 mit Schlitzen versehen ist. Die Flügelzellenpumpe 18 wird von einem exzentrisch zum Nabenteil gebohrten Gehäuse 21 umgeben, das durch einen Stift 23 in seiner Lage fixiert ist.The rotor 14 extends beyond the end face 11 of the injection pump housing 10 and forms here the hub part of the vane pump, which, as shown in FIG. 3, for receiving spring-loaded pump blades 19 is provided with slots. The vane pump 18 is drilled from an eccentric to the hub part Surrounding housing 21, which is fixed in position by a pin 23.

Der Rotor 14 ist mit einer Ringnut 15 versehen, in der ein Dichtungsring 53 angeordnet ist. Der Dichtungsring liegt zwischen dem Gehäuse 21 der Flügelzellenpumpe und der Gehäusestirnfläche 11 sowie zwischen der radialen Stirnfläche 15.a der Nut 15 und der Stirnfläche 11 des Einspritzpumpengehäuses, wodurch er die Eintritts- und Austrittsöffnungen 16 und 17 der Flügelzellenpumpe 18 isoliert. Wie aus Fig. 3 entnommen werden kann, besteht der Dichtungsring 53 aus zwei halbkreisförmigen Elementen, so daß er in die Nut 15 eingesetzt werden kann.The rotor 14 is provided with an annular groove 15 in which a sealing ring 53 is arranged. The sealing ring lies between the housing 21 of the vane pump and the housing face 11 and between the radial end face 15.a of the groove 15 and the end face 11 of the injection pump housing, whereby he the Inlet and outlet openings 16 and 17 of the vane pump 18 are insulated. As can be seen from Fig. 3, the sealing ring 53 consists of two semicircular elements so that it can be inserted into the groove 15.

Zur Befestigung der Flügelzellenpumpe 18 ist eine haubenförmige Kappe 27 vorgesehen, die diese Pumpe umgibt und in eine in ihrer Außenwand mit Gewinde versehene Ringnut 13 in der Gehäusestirnfläche 11 eingeschraubt ist. Innerhalb der Kappe 27 ist an derTo attach the vane pump 18, a hood-shaped cap 27 is provided, which this pump and in an annular groove 13 provided with a thread in its outer wall in the housing end face 11 is screwed in. Inside the cap 27 is on the

ίο Stirnfläche der Kraftstofförderpumpe 18 eine Abdeckplatte 36 angeordnet, die gesondert aus Fig. 4 ersichtlich ist. Die Abdeckplatte 36 weist eine konische Oberfläche auf, die in einer Spitze endet, welche mit der Bodenfläche der Kappe 27 in einem konzentrisch zur Rotorachse liegenden Punkt in Berührung steht. Außerdem besitzt die Abdeckplatte 36 eine flache Seite, die an der dem Rotor abgewandten Stirnseite des Gehäuses 21 und den Enden der Flügel 19 anliegt. Die Kappe 27 weist ferner eine Ringschulter 37 auf, durch die die Abdeckplatte 36 konzentrisch zur Stirnfläche des Rotors 14 angeordnet werden kann. Zur Abdichtung der Kappe 27 gegen das Gehäuse 10 ist ein Dichtungsring 38 vorgesehen. Bei einer solchen Anordnung kann sich die Abdeckplatte 36 automatisch in Bezug auf das Ende der Kraftstofförderpumpe 18 ausrichten und ist in der Lage, sich Fertigungsabweichungen oder Toleranzen anzupassen.ίο the end face of the fuel feed pump 18 is a cover plate 36, which can be seen separately from FIG. The cover plate 36 has a conical Surface that ends in a tip which is concentric to the bottom surface of the cap 27 in a The point lying on the rotor axis is in contact. In addition, the cover plate 36 has a flat side, which rests against the end face of the housing 21 facing away from the rotor and the ends of the blades 19. the Cap 27 also has an annular shoulder 37 through which the cover plate 36 is concentric to the end face of the Rotor 14 can be arranged. A sealing ring is used to seal the cap 27 against the housing 10 38 provided. With such an arrangement, the cover plate 36 can automatically move with respect to the end align the fuel pump 18 and is able to deal with manufacturing deviations or tolerances adapt.

Ferner ist ein Zentrierring 39 vorgesehen, der so dimensioniert ist, daß er sich über die Innenwand der Ringnut 13 schieben läßt und den Dichtungsring 53 sowie das Gehäuse 21 der Flügelzellenpumpe so umgibt, daß er diese Teile in fluchtender Anordnung hält. Diese Konstruktion führt zu einer erheblichen Erleichterung beim Zusammenbau und vereinfacht die Herstellung der Pumpe.Furthermore, a centering ring 39 is provided which is dimensioned so that it extends over the inner wall of the Annular groove 13 can be pushed and surrounds the sealing ring 53 and the housing 21 of the vane pump in such a way that that he keeps these parts in alignment. This construction leads to a considerable relief during assembly and simplifies the manufacture of the pump.

Wie im obigen beschrieben wurde, sind die Antriebswelle 60 und der Rotor 14 zwei getrennte Teile, wobei die Antriebswelle 60 den Rotor dadurch antreibt, daß ihre zusammenwirkenden Schullern 48, 45 einander berühren. In einem in der Welle vorhandenen Ringraum sitzt eine Schraubenfeder 61 und drückt den Rotor 14 von F i g. 1 aus gesehen nach rechts, wodurch die axiale Relativbewegung zwischen der Welle 60 und dem Rotor 14 auf ein Mindestmaß beschränkt wird. Ein Sprengring 97 begrenzt die Bewegung des Rotors 14 nach rechts, wenn die Kappe 27 abgenommen wird.As described above, the drive shaft 60 and the rotor 14 are two separate parts, wherein the drive shaft 60 drives the rotor by virtue of its cooperating Schullern 48, 45 each other touch. A helical spring 61 is seated in an annular space in the shaft and presses the rotor 14 from F i g. 1 to the right as seen, whereby the axial relative movement between the shaft 60 and the rotor 14 is kept to a minimum. A snap ring 97 limits the movement of the rotor 14 to the right, when the cap 27 is removed.

Bei der hier beschriebenen Konstruktion der Kraftstoffverteilereinspritzpumpe wird somit eine Vereinfachung der Herstellung der Pumpe dadurch erreicht, daß die Flügelzellenpumpe 18 außerhalb des Pumpengehäuses angeordnet und ihr stirnseitiges Ende von einer Anordnung aus Kappe und sich selbst einstellender Stirnplatte umschlossen wird, wodurch die Konstruktion unempfindlicher ist gegen bei der Herstellung der Pumpe unvermeidliche Fertigungstoleranzen.The construction of the fuel distributor injection pump described here is thus a simplification the manufacture of the pump is achieved in that the vane pump 18 is outside the pump housing arranged and its front end from an arrangement of cap and self-adjusting Front plate is enclosed, whereby the construction is less sensitive to in the manufacture of the Pump unavoidable manufacturing tolerances.

Hierzu 2 Blatt ZeichnungenFor this purpose 2 sheets of drawings

Claims

Claim:

Fuel distributor injection pump for internal combustion engines with a distributor rotor, which is arranged on the drive side transversely to the distributor axis Bore the piston actuated by a cam ring via roller tappets when the rotor rotates of the injection pump, whose working space between the pump pistons is constantly connected to both a when the rotor rotates alternately to fuel delivery channels connected to injection nozzles in the injection pump housing connectable distributor bore as well as to a Fuel supply bore is connected, via which the pump working chamber during the suction stroke of the pump piston Fuel is supplied from a channel in the injection pump housing, which is connected to a the end facing away from the drive side of the rotor, designed as a vane pump Fuel pump is in connection, the radially displaceable pump blades of which receiving hub part is formed in one piece with the distributor rotor, and with one for Hub part eccentric bore provided housing by means of a remote from the rotor Cover plate resting on the end face on the rotor side against a cover plate resting on the injection pump housing Sealing ring is pressed, characterized in that the hub part of the Vane pump (18) over the end face (11) of the Injection pump housing (10) protrudes and the attachment of the by one on the inner wall of a in the end face (11) of the injection pump housing (10) arranged annular groove (13) and on the housing circumference the vane pump (18) adjacent centering ring (39) aligned coaxially to the rotor axis Housing (21) of the vane pump (18) through one in the outer wall of the annular groove (13) screwed cap (27) takes place, through which the around a in the bottom surface and in the Extension of the bearing point lying on the rotor axis, pivotable cover plate (36) against the end face of the housing (21) of the vane pump is pressed.

The invention relates to a fuel distributor injection pump according to the preamble of the patent claim.

A known injection pump of this type (US Pat. No. 715) is relative in terms of manufacturing technology elaborately built than for the vane pump housing within the housing of the fuel rail injection pump a hole must be provided. which the first-mentioned pump housing completely receives and centered with respect to the rotor. A cover plate placed on the face of the pump housing holds the vane pump housing in the housing bore. This construction demands the Compliance with tight manufacturing tolerances in the manufacture of the vane pump parts and the mounting hole of the injection pump housing so that the rotating Wear occurring parts is limited to a minimum.

The invention is therefore based on the object of providing the fuel feed pump in a fuel distributor injection pump of the type described to be attached so that the manufacturing effort this is low and dimensional deviations can easily be compensated for.

According to the invention, this object is achieved by the features according to the characterizing part of the patent claim.

ίο This construction enables the vane pump to be arranged outside the injection pump housing and the necessary centering of the housing the vane pump in relation to the distributor rotor of the injection pump by means of a simple centering ring ensure that engages in an annular groove of the injection pump housing. The fastening of the pump housing the vane pump through a cap screwed to the injection pump housing over a The cover plate, which is supported centrally on its bottom surface, is relatively simple. Also can certain manufacturing inaccuracies are automatically compensated for by the cover plate.

The invention is explained in more detail below with reference to the exemplary embodiment shown in the drawing explained. In the drawing shows

1 shows a longitudinal section through a fuel distributor injection pump,

Fig. 2 is an enlarged cross-section along the line 4-4 in Fi g. 1,

Fig. 3 is an enlarged cross-section along the line 5-5 in Fi g. 1 and

FIG. 4 is a perspective view of the FIG cover plate shown.

As can be seen from the drawing, the pump has an outer housing 10 with an axial bore 12, in which a distributor rotor 14 is rotatably mounted.

At the right end of the housing 10 shown in Fig. 1 is a serving as a fuel pump Vane pump 18 attached, which is driven by rotor 14 and via an inlet opening 16 and an outlet opening 17 to an inlet channel 20 running diagonally in the pump housing and an outlet channel 24 is connected. The inlet channel 20 supplies the pump 18 with fuel from a Inlet line 22 which is connected to a fuel tank. The feed pump gives the Fuel under pressure through the outlet channel 24 to an air separator 26 located in the housing away.

A high pressure injection pump, generally designated 40 is of a transverse bore 42 in the rotor 14, in which two pump pistons working in opposite directions 44 are arranged displaceably formed. The outer ends of the pump pistons rest on shoes 46 which are slidably installed in transverse passages 48. These passages are made by the fork-shaped end 47 of a drive shaft 60 which is separate from the rotor and which is connected to the transverse bore 42 flees. From the fork-shaped end of the drive shaft 60 there are also two flat, opposite ones Formed shoulders, which are complementary to them shoulders 45 on the rotor 14 in contact to the To drive the rotor. The rotor 14 is surrounded by an annular cam ring 50, which consists of hardened steel and the rotor 14 encloses in the plane of rotation of the pump piston 44. The cam ring 50 is installed in an annular bore 49 in the pump housing so that its angular position