EP3071829A1

EP3071829A1 - Pump for injecting fuel having lubrication incorporated at the spindle of the roller

Info

Publication number: EP3071829A1
Application number: EP14814934.7A
Authority: EP
Inventors: Jean-Baptiste CHANCERELLE; Fabrice Agnoli; Franck Vincent; Gonzalo PORTELA-GARNIKA
Original assignee: Renault SAS
Current assignee: Renault SAS
Priority date: 2013-11-22
Filing date: 2014-11-20
Publication date: 2016-09-28
Also published as: FR3013774A1; WO2015075383A1; FR3013774B1

Abstract

A pump for injecting fuel (10) at high pressure, in particular diesel fuel, for a motor vehicle engine, comprises a tappet (11) including a tappet body (12), a spindle (13) that is fixed with respect to the tappet body (12), a roller (14) that is mounted so as to rotate with respect to the tappet body (12) about the spindle (13) and a bearing (15) disposed between the spindle (13) and the roller (14). The roller (14) is able to cooperate with a cam integral with a crankshaft of the engine. Elements for lubricating the bearing (15) are formed in the material of the spindle (13).

Description

Fuel injection pump with lubrication integrated with the axis of rotation of the roller

Technical field of the invention

The invention relates to a high-pressure fuel injection pump, particularly a diesel fuel pump, for a motor vehicle engine, comprising a pusher including a pusher body, a fixed axis of rotation relative to the pusher body, a roller mounted at rotation relative to the pusher body around the fixed axis of rotation and a bearing disposed between the axis of rotation and the roller, the roller being adapted to cooperate with a cam integral with a crankshaft of the engine.

The subject of the invention is also a motor vehicle engine, in particular of the diesel type, comprising at least one high-pressure fuel injection pump, in particular of gas oil.

State of the art

In the field of such fuel injection pumps, the rotational speed of the roller is important due to the diameter of the cam which is implanted on the crankshaft. It is necessary to provide effective lubrication of the bearing.

A current lubrication solution consists of lubricating by means of nozzles formed in the pusher body and injecting oil at their outlet on the sidewalls of the bearing, which makes it impossible to ensure good homogeneity and good oil flow. in the landing. There is also a problem of providing a good supply of fuel injection pump lubricant in terms of pressure and cooling, while being simple and economical.

A known solution of such a feed consists of a circulation of oil outside the support of the fuel injection pump and specifically dedicated to the lubricant supply function of the injection pump. This is a complex, expensive solution that induces high pressure losses for the lubricant.

Object of the invention

The object of the present invention is to provide a fuel injection pump that overcomes the disadvantages listed above.

In particular, an object of the invention is to provide a solution that allows: a simple, effective and inexpensive lubrication of the bearing within the pump,

a supply of lubricant pump that is simple, effective and economical.

This object can be achieved by means of a high-pressure fuel injection pump, in particular diesel, for a motor vehicle engine, comprising a pusher including a pusher body, a fixed axis of rotation relative to the body. pusher, a roller mounted to rotate relative to the pusher body about the axis of rotation and a bearing disposed between the axis of rotation and the roller, the roller being adapted to cooperate with a cam integral with a crankshaft of the engine , lubricating elements of the bearing being formed in the material of the axis of rotation. Preferably, the lubricating elements comprise at least one supply channel allowing the circulation of a lubricating fluid, especially oil, and formed in the volume of the axis of rotation.

Said at least one supply channel may in particular lead to one of its ends at a zone of the contact interface between an inner face of the bearing and an outer face of the axis of rotation at which the lubricant flows out of the supply channel.

Preferably, said zone of the interface is a zone of the axis of rotation diametrically opposite with respect to the zone of the axis of rotation accommodating the forces transmitted by the roller when it cooperates with the cam of the crankshaft.

Said at least one feed channel can also lead to one of its ends at a feed zone of the pusher body at which the lubricating fluid enters the axis of rotation.

According to one embodiment, the lubrication elements comprise first and second rectilinear supply ducts arranged in a series and a V-shaped fluidic connection.

According to another embodiment, the lubrication elements comprise a feed channel having a first end opening into the supply zone of the pusher body and a second end opening into the interface zone between the bearing and the axis. rotation coinciding with the region of the axis of rotation accommodating the forces transmitted by the roller when it cooperates with the cam of the crankshaft.

Each supply duct may in particular be a bore made in the material of the axis of rotation. Preferably, the lubrication elements comprise at least one distribution groove formed in the outer face of the axis of rotation at the contact interface between the inner face of the bearing and the outer face of the axis of rotation and allowing the circulation of a lubricating fluid, especially oil, to distribute said lubricant fluid along this interface.

The distribution groove may be rectilinear, oriented along the axis of revolution of the axis of rotation and arranged in the zone of the interface formed by a zone of the axis of rotation diametrically opposite to the zone of the rotation axis accommodating the forces transmitted by the roller when it cooperates with the cam of the crankshaft.

Lubricant supplying elements lubricating the lubrication elements formed in the material of the axis of rotation may be formed in the material of the pusher body, especially in the form of at least one communicating supply channel. fluidic with the lubrication elements.

A motor vehicle engine, particularly of diesel type, may include at least one such high-pressure fuel injection pump, in particular diesel, a crankshaft comprising a cam cooperating with the pump roller, wherein the lubricant circulating in the bearing lubrication elements formed in the material of the axis of rotation is the same lubricant as that which provides the lubrication inside the engine block.

In the case where the engine comprises a lubrication circuit of the engine, it may comprise lubricant supply elements formed in the material of the engine block and / or in the pump support on the engine block and in which the engine circulates. lubricant taken from the lubrication circuit and supplying the lubrication elements of the pump bearing with the lubricant taken from the engine lubrication circuit. According to one embodiment, the feed elements formed in the material of the engine block and / or in the support comprise at least one lubricant circulation duct opening into the main lubricant ramp delimited by the engine block.

Lubricant return elements may be formed in the material of the engine block and / or carrier, ensuring the return of the lubricant into the engine lubrication circuit after it has been circulated in the pump lubrication elements.

Brief description of the drawings

Other advantages and features will emerge more clearly from the following description of particular embodiments of the invention given as non-restrictive examples and shown in the accompanying drawings, in which:

FIG. 1 is a front view of an example of a fuel injection pump according to the invention,

FIG. 2 is a side view in axial / vertical section of the portion of the pump located in zone A of FIG. 1;

FIG. 3 is a perspective view from below of the part of FIG. 2, the axis of rotation being represented in a transparent manner,

FIG. 4 is a perspective view of the axis of rotation represented in an axial / vertical section,

FIG. 5 is a side view in axial / vertical section of another variant of the portion of the pump located in zone A of FIG. 1;

FIG. 6 is a perspective view of the engine block supporting the fuel injection pump,

FIG. 7 represents the same elements as FIG. 6 but in a vertical section through the fuel injection pump,

and FIG. 8 is a detailed side view of the elements of FIG. 7, at the level of the injection pump and its support. Description of preferred modes of the invention

With reference to FIGS. 1 to 8, the invention relates to a high-pressure fuel injection pump 10, in particular a diesel fuel pump, for a motor vehicle engine, comprising a pusher 11 including a pusher body 12, an axis of rotation 13 fixed relative to the pusher body 12, a roller 14 rotatably mounted relative to the pusher body 12 about the fixed axis of rotation 13 and a bearing 15 disposed between the axis of rotation 13 and the roller 14. The roller is adapted and intended to cooperate with a cam integral with a crankshaft of the engine. The displacement of the pusher body 12 under the impetus of the roller 14 in contact with this cam, during the rotation of the crankshaft, controls the fuel injection.

The fuel injection pressure is of the order of 2000 bar for commercially known fuel pumps and the force between the roller and the cam is of the order of 10 KN at an engine speed of 4000 rpm. The lubricating oil pressure then required is between 1 and 4 l / min.

According to an essential characteristic, lubricating elements of the bearing 15 are formed in the material of the axis of rotation 13. They are essentially elements making it possible to supply lubricant, in particular of the liquid type such as oil. , at the level of the bearing 15 to ensure its lubrication during the rotation of the roller 14 about the axis of rotation 13.

Preferably, the lubrication elements comprise at least one feed channel allowing the circulation of a lubricating fluid, especially oil, and formed in the volume of the axis of rotation 13, that is to say the Rotational axis material 13. Two variants of such lubrication elements will be detailed. In all cases, said at least one feed channel preferably opens at one of its ends at a zone 16 of the contact interface between an inner face of the bearing 15 and a face outside of the axis of rotation 13 at which the lubricant flows out of the supply channel.

In a first variant with reference to FIGS. 2 and 4, this zone 16 of the interface is a zone of the axis of rotation 13 that is diametrically opposite with respect to zone 17 of the axis of rotation 13, accommodating the forces F transmitted by the roller 14 when it cooperates with the cam of the crankshaft.

Preferably, said at least one feed channel opens at one of its ends at a feed zone 18 formed in the pusher body 12 at which the lubricant fluid enters the axis of rotation 13 .

In the embodiment of FIGS. 2 and 4, the lubrication elements comprise a first supply duct 19 and a second straight supply duct 20 arranged in a series and a V-shaped fluid connection, in particular a such that:

a first end of the first feed channel opens to the pusher body 12 at the feed zone 18,

a second end of the first channel 19 opens into a first end of the second supply channel 20,

- A second end of the second feed channel 20 opens out to the zone 16 of the interface between the bearing 15 and the pivot axis 13.

Each supply duct 19, 20 is formed in particular by a hole made in the material of the axis of rotation 13. The advantage of such a double V-shaped boring is that it is possible to practice the oil inlet drilling. the opposite of the most stressed zone of the axis of rotation 13 in terms of loading forces F.

In a second variant and with reference to FIG. 5, implemented alternatively or in combination with the first variant, the elements of lubrication comprise a feed channel 21 having a first end opening into the feed zone 18 of the pusher body 12 and a second end opening into the region of the interface between the bearing 15 and the axis of rotation 13 coinciding with the zone 17 of the axis of rotation 13 accommodating the forces F transmitted by the roller 14 when it cooperates with the cam of the crankshaft.

The feed duct 21 is formed in particular by a hole made in the material of the axis of rotation 13. In other words, if the mechanical stresses of the axis of rotation 13 are sufficiently small, it is possible to perform a single drilling. in the axis of rotation 13 directly down this axis 13 from the zone 18 located near the top of the axis 13.

Preferably, the lubrication elements comprise at least one distribution groove 22 formed in the outer face of the axis of rotation 13 at the contact interface between the inner face of the bearing 15 and the outer face of the axis of rotation. rotation 13 and allowing the circulation of a lubricating fluid, especially oil, to distribute this lubricant fluid along said zone 16.

Thus, in the first variant, the second end of the second feed channel 20 opens preferentially into the distribution groove 22.

Although its shape may be arbitrary, the distribution groove 22 is preferably rectilinear, oriented along the axis of revolution X of the axis of rotation 13 and arranged in the zone 16 of the interface formed by a zone of the axis 13 of diametrically opposite rotation with respect to the zone 17 of the axis of rotation 13 accommodating the forces F transmitted by the roller 14 when it cooperates with the cam of the crankshaft.

This optional dispensing groove 22 can therefore be machined on the top of the axis of rotation 13, which again corresponds to the zone 16 no. loaded in the case where the forces F are only applied to the bottom of the axis of rotation 13 and directed from bottom to top of the axis of rotation. The distribution of the oil is optimum throughout the width of the bearing 15.

The dimensions of the distribution groove 22 have two impacts on the lubrication conferred on the bearing 15:

the length of the distribution groove 22 according to X makes it possible to dimension the homogeneity of the lubrication over the width of the bearing 15: the homogeneity grows at the same time as the length of the groove 22,

the distance between the distribution groove 22 and the axial ends of the bearing 15 and the cutting section of the distribution groove 22 (perpendicular to X) makes it possible to size the oil flow: the cooling increases at the same time as the flow rate.

It should be noted that this distribution groove 22 may be absent if the value of the forces F which load the axis is quite low.

In addition to the lubrication elements described above, the fuel injection pump includes lubricant supply elements supplying lubricant to these lubrication elements. These feed elements are formed in the material of the pusher body 12, in particular in the form of at least one supply channel 23 in fluid communication with the lubrication elements and hollowed out of the material of the pusher body 12.

The lubricating solution described above allows so-called forced lubrication of the bearing 15 and makes it possible to establish a homogeneous lubricant film and to effectively evacuate the calories. The channels and conduits are machined so as to supply the pressurized lubricant directly where it is needed, that is to say at the interface between the bearing 15 and the axis of rotation 13. Thus, a motor vehicle engine, particularly diesel type, may include at least one such high-pressure fuel injection pump 10, including diesel, a crankshaft (not shown) comprising a cam (not shown) cooperating with the roller 14 of the pump 10. In this engine, the lubricant flowing in the bearing lubrication elements 15 formed in the material of the axis of rotation 13 is the same lubricant as that which provides the lubrication inside the engine block 24.

Preferably, in the particular case where the engine comprises a lubricating circuit of the engine, in particular for the operation of the pistons and the crankshaft, the engine comprises lubricant supply elements formed in the material of the engine block 24 and / or in the support 25 of the pump 10 on the engine block 24 and in which circulates lubricant taken from the lubrication circuit and supplying the lubrication elements of the bearing 15 of the pump 10 with the lubricant taken from the lubrication circuit of the engine.

For this purpose, the feed elements formed in the material of the engine block 24 and / or in the support 25 comprise at least one lubricant circulation duct 27 opening into the main lubricant ramp 26 defined by the engine block 24.

Said at least one supply channel 23 thus comprises an end 29 opening towards one end of the circulation duct 27 and an opposite second end opening into the supply zone 18. The first end 29 of this channel 23 is in fluid communication with the circulation duct 27. The second end of this channel 23 is in fluid communication with either the first end of the duct 19 or the first end of the duct 21.

In addition to the lubricant supply elements, the motor preferably comprises lubricant return elements 28 formed in the material of the engine block 24 and / or the support 25, ensuring the return of the lubricant in the engine lubrication circuit after its circulation in the lubrication elements of the pump 10.

Thus, the supply of the lubricant injection pump 10 used for the lubrication of the bearing 15 necessary for the operation of the roller 14 is a dedicated supply circuit coming from the engine lubrication circuit, in the direction relating to the supply of the pump 10 and in the direction relating to the return of the pump 10 to the engine lubrication circuit. The injection pump 10 is supplied with high pressure oil, at the pressure and at the temperature of the main lubricant ramp 26, through the circulation duct 27, for example in the form of a bore formed in the engine block 24 and / or in the support 25 of the injection pump 10 on the engine block 24. Then after its circulation in the fuel injection pump 10, a portion of the oil is recovered through the return elements 28 which provide the return of this recovered oil by falling by gravity into the oil pan of the engine block 24, the other part is diffused by the sides of the roller bearing.

The preceding solution provides a good supply of lubricant to the fuel injection pump 10 in terms of pressure and cooling, as close as possible to the injection pump 10 and directly in its support 25 and / or in the engine block 24 These arrangements allow a great simplicity and a reduction in costs compared to current solutions that require a dedicated supply only for the lubrication of the injection pump.

Claims

1. High-pressure fuel injection pump (10), in particular a diesel fuel pump, for a motor vehicle engine, comprising a pusher (1 1) including a pusher body (12), an axis of rotation (13) fixed relative to the pusher body (12), a roller (14) rotatably mounted relative to the pusher body (12) about the axis of rotation (13) and a bearing (15) disposed between the axis of rotation (13). and the roller (14), the roller (14) being adapted to cooperate with a cam integral with a crankshaft of the engine, characterized in that bearing lubrication elements (15) are formed in the material of the axis of rotation (13).

Injection pump (10) according to claim 1, characterized in that the lubrication elements comprise at least one feed channel (19, 20, 21) for the circulation of a lubricating fluid, in particular of the oil, and formed in the volume of the axis of rotation (13).

3. Injection pump (10) according to claim 2, characterized in that said at least one feed channel (19, 20, 21) opens at one of its ends at a zone of the contact interface between an inner face of the bearing (15) and an outer face of the axis of rotation (13) at which the lubricant flows out of the feed channel (19, 20, 21).

4. Injection pump (10) according to claim 3, characterized in that said zone of the interface is a zone (16) of the axis of rotation (13) diametrically opposite to the zone (17) of the axis of rotation (13) accommodating the forces (F) transmitted by the roller (14) when it cooperates with the cam of the crankshaft.

5. Injection pump (10) according to one of claims 2 to 4, characterized in that said at least one feed channel (19, 20, 21) opens at one of its ends at the level of a feed zone (18) of the pusher body (12) at which the lubricating fluid enters the axis of rotation (13).

Injection pump (10) according to one of claims 2 to 5, characterized in that the lubrication elements comprise first and second rectilinear supply ducts (19, 20) arranged in a series fluid connection and according to a provision in V.

Injection pump (10) according to one of claims 2 to 5, characterized in that the lubrication elements comprise a feed channel (21) having a first end opening into the feed zone (18). of the pusher body (12) and a second end opening into the interface zone between the bearing (15) and the axis of rotation (13) coinciding with the zone (17) of the rotating axis (13) the forces (F) transmitted by the roller (14) when it cooperates with the cam of the crankshaft.

Injection pump (10) according to one of claims 2 to 7, characterized in that each supply duct (19, 20, 21) is a bore made in the material of the axis of rotation (13). ).

9. Injection pump (10) according to one of claims 1 to 8, characterized in that the lubrication elements comprise at least one distribution groove (22) formed in the outer face of the axis of rotation (13). ) at the contact interface between the inner face of the bearing (15) and the outer face of the axis of rotation (13) and allowing the circulation of a lubricating fluid, especially oil, to distribute said lubricant fluid along this interface.

10. Injection pump (10) according to claim 9, characterized in that the distribution groove (22) is rectilinear, oriented along the axis of revolution (X) of the axis of rotation (13) and arranged in the zone of the interface formed by an area (16) of the axis of rotation (13) diametrically opposite to the zone (17) of the axis of rotation (13) accommodating the forces (F) transmitted by the roller (14) when it cooperates with the cam of the crankshaft.

1 1. Injection pump (10) according to one of claims 1 to 10, characterized in that lubricant feed elements supplying lubricant to the lubrication elements formed in the material of the rotational axis (13) are formed. in the material of the pusher body (12), especially in the form of at least one supply channel (23) in fluid communication with the lubrication elements.

12. Motor vehicle engine, including Diesel type, comprising at least one fuel injection pump (10) at high pressure, in particular diesel, according to any one of the preceding claims, a crankshaft comprising a cam cooperating with the roller (24) of the pump, wherein the lubricant circulating in the bearing lubrication elements (15) formed in the material of the axis of rotation (13) is the same lubricant as that which provides the lubrication inside. of the engine block (24).

13. Engine according to claim 12, comprising a motor lubrication circuit, characterized in that it comprises lubricant supply elements (27, 28) formed in the material of the engine block (24) and / or in the support (25) of the pump (10) on the engine block (24) and in which lubricant is withdrawn from the lubrication circuit and supplying the lubrication elements of the bearing (15) of the pump (10) with the lubricant taken from the engine lubrication circuit.

Motor according to Claim 13, characterized in that the feed elements (27, 28) formed in the material of the motor unit (24) and / or in the support (25) comprise at least one lubricant circulation duct (27) opening into the main lubricant ramp (26) delimited by the engine block (24).

15. Motor according to one of claims 13 or 14, characterized in that lubricant return elements (28) are formed in the material of the engine block (24) and / or the support (25), ensuring the return of the lubricant in the engine lubrication circuit after it has been circulated in the lubrication elements of the pump (10).