Title of Invention

A DISTRIBUTOR INJECTION PUMP

Abstract

In a distributor injection pump, with a casing (10) and with a roller ring (12) which is arranged adjustably in the casing and is provided with at least one roller (20), on which can be supported a cam disk (28) serving for actuating a pump piston, the roller being mounted in the roller ring by means of a bolt (24) which extends in the radial direction in relation to the mid-axis of the roller ring, the force which acts on the bolt when the roller is under load and which is directed radially outward is to be prevented from leading to the casing being damaged, For this purpose, there is provision for a supporting element (40) to be arranged at the radially outer end of the bolt (24).

Full Text

The invention relates to a distributor injection pump with a casing and with a roller ring which is arranged adjustably in the casing and is provided with at least one roller, on which can be supported a cam disk serving for actuating a pump piston, the roller being mounted in the roller ring by means of a bolt which extends in the radial direction in relation to the mid-axis of the roller ring. Such a distributor injection pump serves for supplying the correct quantity of fuel at the correct time to a cylinder of an internal combustion engine. For this purpose, the pump piston is provided, which is connected to the cam disk. When the cam disk is rotated in relation to the roller ring, its surface provided with cams rolls on the rollers. The cam disk thereby experiences a stroke movement which is transmitted to the pump piston. The forces acting on the bolts during a stroke produce a periodic force component which acts on the bolt and moves the bolt outwards in the radial direction with respect to the mid-axis of the roller ring. The result of this may be that, when the roller ring is under high loads, the bolts, which normally consist of steel, hammer or dig with their radially outer end into that part of the casing which is located opposite this end and mostly consists of aluminum. This may, in the long term, impair the functional reliability of the injection pump. The object on which the invention is based is, therefore, to develop a distributor injection pump of the type initially mentioned, to the effect that the bolts of the roller ring are reliably prevented from digging into the casing of the distributor injection pump. Advantages of the invention The distributor injection pump having a supporting element arranged at the radially outer end of the bolt. The supporting element serves for introducing the axial force acting on the bolt into the casing of the distributor injection pump over a large area. The wearing force exerted locally on the casing by the bolt is thus greatly reduced, so that material damage cannot occur. According to a preferred embodiment of the invention, there is provision for the supporting element to be a clip which is arranged on the roller ring and is snapped into orifices on the roller ring. The clip covers the radially outer end of the both and, when an axial force is exerted on the bolt, is deformed outward toward the casing of the distributor injection pump, so that it comes to bear on the casing and introduces the axial force acting on the boll into the casing over a large area. The material preferably selected for the clip is steel. According to an alternative embodiment, there is provision for the supporting element to be arranged on the casing. In this embodiment, the supporting element, which preferably consists of steel, is designed as an insertion part which prevents direct contact between the bolt consisting of steel and the casing consisting of aluminum, in this embodiment, too, an axial force acting on the bolt is first transmitted to the supporting element, from which it is introduced, in turn, into the casing over a large area. Advantageous refinements of the invention are described herein. The invention is described below with reference to a preferred embodiment illustrated in the accompanying drawings in which: fig. 1 shows a diagrammatic sectional view of part of a distributor injection pump according to the invention; fig. 2 shows a perspective view of part of a roller ring which is used in the distributor injection pump of fig. 1; and fig. 3 shows a further perspective view of part of the roller ring. Description of the exemplary embodiment Fig. 1 shows a diagrammatic part section through a distributor injection pump according to the invention, which serves for injecting fuel into a cylinder of an internal combustion engine. The injection pump contains a casing 10, in which a roller ring 12 is arranged. The roller ring 12 has an inner ring 14 and an outer ring 16 which between them form an annular receptacle 18. Within the annular receptacle 18 are arranged a plurality of rollers 20 which are mounted in each case via a bush 22 on a bolt 24. Each bolt 24 extends in the radial direction with respect to a mid-axis of the roller ring 12 and is received with its radially inner end in the inner ring 14, while its radially outer end is received in the outer ring 16. A thrust washer 2 6 is also arranged between the outer ring 16 and each roller 20, A cam disk 28 cooperates with the rollers 20 and is loaded against the rollers 20 by a compression spring 30. Connected to the cam disk 28 is an extension 32 which, in turn, is connected to a pump piston (not illustrated). A driveshaft 36 is provided, which can set the cam disk 28 in rotation via coupling 3 8. The cam disk 2 8 then runs on the rollers 20 with its surface facing the rollers 2 0 and provided with cams, thus producing a periodic stroke movement of the cam disk 2 8 which is transmitted to the pump piston which finally conveys the fuel to be injected. In order to set the injection time in relation to the crankshaft angle of the internal combustion engine supplied, an injection timer (not illustrated) is also provided, by means of which the roller ring 12 can be rotated through a specific angle in the casing. The construction and functioning of such an injection timer are generally known, and therefore they are not reproduced here. Mounted on the roller ring 12 is a supporting element 40 (see also figures 2 and 3) provided with two bent ends 42 which serve as spring shackles. Each bent end engages into an orifice 44 which is formed on the outer ring 16 of the roller ring 12, The supporting element 4 0 extends over an angular range which is very much larger than the angular range over which the radially outer end of the corresponding bolt 24 extends and essentially covers the radially outer end of the corresponding bolt, In order to prevent the supporting element 40 from projecting beyond the outer circumference of the outer ring 16, each supporting element is arranged in a clearance 46 which extends between two orifices 44 assigned to the same supporting element 40, When a high force is exerted on the rollers 20 during the operation of the distributor injection pump, an axial force acting in the direction of the arrow F of fig. 3 is produced. During a resulting displacement of the bolt 24, the latter presses the supporting element 40 outward, so that this is supported on the casing 10 of the distributor injection pump. A large contact area, over which the acting axial force can be introduced into the casing, is thereby obtained. The material which may be used for the supporting element 4 0 is, in particular, steel. Alternatively, it may also be envisaged to use a suitable plastic, Contrary to the embodiment shown, in which a separate supporting element is used for each bolt, it may also be envisaged to use a single supporting element for all the bolts. Also, instead of the supporting element shown, made of flat material, it is possible, for example, to use a wire clip which either surrounds the entire outer ring 16 and is arranged in the region of the axially outer ends of the bolts 24 or is snapped in each case separately into the orifices 44. WE CLAIM : 1. A distributor injection pump, with a casing (10) and with a roller ring (12) which is arranged in the casing and is provided with at least one roller (20), on which is supported a cam disk (28) serving for actuating a pump piston, the roller being mounted in the roller ring by means of a bolt (24) which extends in the radial direction in relation to the mid-axis of the roller ring, characterized in that a supporting element (40) is arranged at the radially outer end of the bolt (24). 2. The distributor injection pump as claimed in claim 1, wherein the supporting element (40) is arranged on the roller ring (12). 3. The distributor injection pump as claimed in claim 2, wherein the supporting element (40) is a clip which is snapped into orifices (44) in the roller ring. 4. The distributor injection pump as claimed in claim 3, wherein the clip is a spring clip. 5. The distributor injection pump as claimed in any one of claims 2 to 4, wherein the roller ring is provided with a clearance (46) for the supporting element (40). 6. The distributor injection pump as claimed in claim 1, wherein the supporting clement is arranged on the casing (10). 7. The distributor injection pump as claimed in claim 6, wherein the supporting clement (40) is an insertion part. 8. The distributor injection pump as claimed in any one of claims 1 to 7, wherein the supporting element (40) consists of metal. 9. The distributor injection pump as claimed in any one of claims 1 to 7, wherein the supporting element consists of plastic.

Documents:

abs-in-pct-2001-1414-che.jpg

in-pct-2001-1414-che-abstract.pdf

in-pct-2001-1414-che-claims filed.pdf

in-pct-2001-1414-che-claims granted.pdf

in-pct-2001-1414-che-correspondnece-others.pdf

in-pct-2001-1414-che-correspondnece-po.pdf

in-pct-2001-1414-che-description(complete)filed.pdf

in-pct-2001-1414-che-description(complete)granted.pdf

in-pct-2001-1414-che-drawings.pdf

in-pct-2001-1414-che-form 1.pdf

in-pct-2001-1414-che-form 18.pdf

in-pct-2001-1414-che-form 26.pdf

in-pct-2001-1414-che-form 3.pdf

in-pct-2001-1414-che-form 5.pdf

in-pct-2001-1414-che-other document.pdf

in-pct-2001-1414-che-pct.pdf