DE102008015548A1 - High-pressure pump i.e. radial or series piston pump, for fuel injection system of air-compressing self-ignition internal-combustion engine, has anti-twist protection pin indirectly connecting with roller support and housing parts - Google Patents

Abstract

The pump (1) has a pump assembly (11) and a drive shaft (6) with a cam (10) that is attached to the pump assembly. The pump assembly has a roller (27) running on the cam of the drive shaft. The pump assembly has a roller support (26) accommodating the roller. An anti-twist protection pin (35) indirectly stays in effective connection with the roller support and with housing parts (3-5) such as base body, cylinder head and flange. The anti-twist protection pin is inserted into the roller support at an end (36).

Description

State of the art

The The invention relates to a high-pressure pump, in particular a radial or inline piston pump for fuel injection systems for Conveying fuel. Specifically, the invention relates the field of fuel pumps for fuel injection systems of air-compressing, self-igniting internal combustion engines.

From the DE 10 2005 046 670 A1 a high pressure pump for a fuel injector of an internal combustion engine is known. The known high-pressure pump has a pump housing, in which a pump element is arranged, which has a driven by a drive shaft in a stroke pump piston. The pump piston is slidably guided in a cylinder bore of a part of the pump housing and limited in this one pump working space. The pump piston is supported on the drive shaft via a hollow-cylindrical plunger, wherein the plunger is displaceably guided in a bore of a part of the pump housing in the direction of a longitudinal axis of the pump piston. Furthermore, the plunger has a groove extending in its outer jacket in the direction of its longitudinal axis, in which engages radially to the longitudinal axis of the plunger in a part of the pump housing in a tangential direction to the plunger fixed ball for preventing rotation of the plunger.

The from the DE 10 2005 046 670 A1 known high-pressure pump has the disadvantage that the design of the rotation is expensive, especially since design changes to the pump housing are required and additional components are needed. Furthermore, there is the disadvantage that in the operation of the high-pressure pump by the periodic stroke of the hollow cylindrical plunger friction forces in the ball to prevent rotation of the plunger occur, which adversely affect the efficiency of the high-pressure pump.

Disclosure of the invention

The High-pressure pump according to the invention with the features of claim 1 has the advantage that a force-closing Anti-rotation is guaranteed. Especially one can Verdrehsicherung be achieved, the rotation of a roller shoe or a tappet body receiving the roller shoe prevented without wear.

By the measures listed in the dependent claims are advantageous developments of specified in claim 1 High pressure pump possible.

In Advantageously, the anti-rotation pin is at a first Inserted end of the anti-rotation pin in the roller shoe. Furthermore, the anti-rotation pin at its first end with be connected to the roller shoe. This allows a permanent stable Operative connection between the anti-rotation pin and the roller shoe. Advantageously, the anti-rotation pin is at a first End at least partially in a ram body the pump assembly used, wherein the plunger body connected to the roller shoe. It is also advantageous that the anti-rotation pin at its first end with the plunger body the pump assembly is connected. This can be achieved that a permanently stable operative connection between the anti-rotation pin and the plunger body is configured. The roller shoe stands thereby at least indirectly over the with the roller shoe connected ram body with the anti-rotation pin in operative connection. And that's it possible that the anti-rotation pin on its first End with both the plunger body as also engaged with and / or connected to the roller shoe is.

Further It is advantageous that the anti-rotation pin on a second End of the anti-rotation pin inserted into the housing part is. In this case, the anti-rotation pin at the second end in advantageously also connected to the housing part be. This allows a permanently stable operative connection between the anti-rotation pin and the housing part.

In Advantageously, on the anti-rotation pin is a bending section provided on which the anti-rotation pin is bendable. The bending section can be designed so that a required movement play allows for the stroke generated by the cam is. Furthermore, by the bending portion a certain twisting of the Roller shoe with respect to a starting position allows Be that for a smooth unrolling the role on the cam may be required.

It is also advantageous that the anti-rotation pin has an elastic spring portion which allows a bending and / or a change in length of the anti-rotation pin. Specifically can be compensated by the change in length of the anti-rotation pin occurring when rolling the roller on the cam stroke, while the flexibility of the elastic spring portion a certain backlash for the roller shoe and thus the roller running on the cam is enabled. Thus, a reliable operation of the high-pressure pump is ensured, whereby excessive rotations of the roller shoe and thus the roller with respect to the running surface of the cam prevented are.

Of the Elastic spring section can advantageously by a Spring element or by an at least approximately wave-shaped Embodiment of the anti-rotation pin in the elastic spring section be designed.

Of the Anti-rotation pin preferably has a relatively low rigidity on, but which is chosen so that an excessive Rotation of the roller shoe and thus the role is prevented.

Of the Anti-rotation pin can be attached to its second end at one in the Near the pump assembly lying point with the housing part be in operative connection, in particular be connected to this. This is particularly suitable for an anti-rotation pin, having a bending section.

Further it is also advantageous that the anti-rotation pin sections is guided around the drive shaft and that the anti-rotation pin on a remote from the pump assembly body with the housing part is in operative connection, in particular connected to this. This embodiment is particularly suitable for a wave-shaped Section or the like within the anti-rotation pin provide, with the space required for this purpose possibly present or with little design effort can be created.

Advantageous It is also provided that another anti-rotation pin is, wherein the anti - rotation pins on different sides of the Cam of the drive shaft are arranged. This results in a symmetrical design. Depending on the particular If necessary, the operating behavior of the Pump assembly, in particular the leadership of the plunger body in a bore of the housing, favorably influenced become.

Brief description of the drawings

preferred Embodiments of the invention are in the following Description with reference to the accompanying drawings, in which corresponding elements with matching reference numerals are provided, explained in more detail. It shows:

1 a high pressure pump in a schematic, axial sectional view according to a first embodiment of the invention;

2 the in 1 labeled II section of a high-pressure pump according to a second embodiment of the invention;

3 an anti-rotation pin of a high-pressure pump according to a third embodiment of the invention and

4 an anti-rotation pin of a high-pressure pump according to a fourth embodiment of the invention.

embodiments the invention

1 shows a high pressure pump 1 in a schematic, axial sectional view according to a first embodiment of the invention. The high pressure pump 1 can be used in particular as a radial or inline piston pump for fuel injection systems of air-compressing, self-igniting internal combustion engines. A preferred use of the high-pressure pump 1 consists of a fuel injection system with a fuel rail, a so-called common rail, which stores diesel fuel under high pressure. The high-pressure pump according to the invention 1 However, it is also suitable for other applications.

The high pressure pump 1 has a multi-part housing 2 on. There are in the 1 the housing parts 3 . 4 . 5 shown. The housing part 3 serves as a basic body, the housing part 4 represents a cylinder head and the housing part 5 is designed as a flange. Here are the housing parts 4 . 5 with the housing part 3 connected.

The high pressure pump 1 also has a drive shaft 6 on that in the case 2 at two in the direction of an axis 7 the drive shaft 6 spaced bearings 8th . 9 is stored. Between the two bearings 8th . 9 has the drive shaft 6 a cam 10 on. The cam 10 can also by an eccentric to the axis 7 formed section on the drive shaft 6 be formed. Furthermore, the cam 10 be designed as a multiple cam.

The high pressure pump 1 also has a pump assembly 11 on, with the cam 10 the drive shaft 6 the pump assembly 11 is assigned and for driving the pump assembly 11 during operation of the high pressure pump 1 serves. In this case, the high-pressure pump 1 have further pump assemblies, which correspond to the pump assembly 11 are designed.

The housing part 3 has a hole 12 on, in which the pump assembly 11 is arranged. Furthermore, the housing part 4 an approach 13 up into the hole 12 protrudes. The approach 13 is at least substantially radially symmetric to an axis 14 of the approach 13 formed perpendicular to the axis 7 the drive shaft 6 , that is, in the radial direction, is oriented. The approach 13 has one in the direction of the axis 14 of the approach 13 extending cylinder bore 15 on, in which a piston 16 in the direction of the axis 14 slidably guided. The piston 16 limits a pump work space 17 the cylinder bore 15 , The pump workroom 17 is with a fuel channel 18 connected, in which an inlet valve 19 that is towards the pump work space 17 opens. Further, the pump work space 17 with a fuel channel 20 connected, in which an outlet valve 21 is arranged, that of the pump work space 17 opens away. Above the fuel channel 20 can the high pressure pump 1 promote a fuel to a common rail or the like.

The pump assembly 11 has a plunger body 25 on, which is configured at least substantially hollow cylindrical. Here is the plunger body 25 in the hole 12 of the housing part 3 guided. The plunger body 25 takes a roller shoe 26 on that with the plunger body 25 connected is. Further, a role 27 provided by the roller shoe 26 is included. The role 27 is located on the cam 10 on and runs during operation of the high-pressure pump 1 on an outer surface of the cam 10 from. This is the roller shoe 26 over the tappet body 25 from a return spring 28 acted, even at high speeds of rotation a concern of the roller shoe 26 on the roll 27 and a concern of the role 27 on the cam 10 guaranteed.

Further, in the plunger body 25 a carrier element 29 used that the piston 16 above a covenant 30 encloses and thus the piston 16 at the federal government 30 holds and against the roller shoe 26 holds. This will cause the piston 16 together with the tappet body 25 and thus the roller shoe 26 and the role 27 while running the role 27 on the cam 10 taken along, causing a periodic reciprocation of the piston 16 during operation of the high pressure pump 1 is reached, as indicated by the double arrow 31 is illustrated. At this movement of the piston 16 takes place alternately a promotion of fuel through the fuel channel 18 from a feed pump into the pump work space 17 , then a compression of the fuel in the pump workspace 17 and conveying the high pressure fuel from the pump working space 17 over the fuel channel 20 to a common rail.

In the 1 is shown a starting position in which an axis 32 the role 27 coaxial to the axis 7 the drive shaft 6 is. Already during commissioning and during operation of the high-pressure pump 1 can the role 27 however from the in the 1 be shown tilted starting position, so that the axis 32 the role 27 no longer coaxial with the axis 7 the drive shaft 6 is. Within certain limits, such tilting has no influence on the operation of the high-pressure pump 1 And a certain amount of leeway can also be used for reliable operation of the high-pressure pump 1 to be required. However, there is excessive rotation of the axle 32 the role 27 from their coaxial basic position the danger that the functioning of the high-pressure pump 1 is impaired or the high pressure pump 1 even fails. This can already at the first start of the high-pressure pump 1 as a problem.

To an excessive rotation of the axle 32 the role 27 to prevent from their coaxial basic position is an anti-rotation pin 35 intended. The anti-rotation pin 35 is at least partially in the hole 12 of the housing part 3 arranged. A first end 36 is both sections in the ram body 25 as well as sections in the roller shoe 26 used and with the plunger body 25 as well as the roller shoe 26 connected. This is the anti-rotation pin 35 both with the tappet body 25 as well as with the roller shoe 26 in active connection. There is also a second end 37 of the anti-rotation pin 35 at one of the pump assembly 11 remote location with the housing part 5 connected. This is the second end 37 of the anti-rotation pin 35 in the housing part 5 used, so that an operative connection between the housing part 5 and the anti-rotation pin 35 consists. There is also a section 38 of the anti-rotation pin 35 around the axis 7 guided. Furthermore, the anti-rotation pin 35 an elastic spring section 39 on, the bending and / or a change in length of the anti-rotation pin 35 allows. The spring section 39 is by a wave-shaped design of the anti-rotation pin 35 in this spring section 39 educated. Furthermore, the anti-rotation pin 35 a relatively low rigidity. In particular, by the spring section 39 of the anti-rotation pin 35 can be used while unrolling the roll 27 on the cam 10 occurring strokes of the plunger body 25 and the roller shoe 26 be compensated. Furthermore, excessive rotation of the roller shoe 26 and thus from the roller shoe 26 recorded role 27 that is a function of the high pressure pump 1 impaired, prevented.

2 shows the in 1 designated II section of a high-pressure pump 1 according to a second embodiment. In this embodiment, the first end 36 of the anti-rotation pin 35 only in the ram body 25 used. The roller shoe 26 is with the plunger body 25 connected so that the roller shoe 26 by means of the plunger body 25 with the anti-rotation pin 35 is in active connection. Further, the second end 37 in this embodiment, at a near the pump assembly 11 lying position with the housing part 5 connected. Furthermore, the anti-rotation pin 35 a bending section 40 on, on which the anti-rotation pin 35 is bendable. In particular, by the bendability of the bending section 40 of the anti-rotation pin 35 can be a lifting movement of the roller shoe 26 with the tappet body 25 be compensated. This is an excessive rotation of the axis 32 the role 27 prevented from their coaxial basic position.

There is also another anti-rotation pin 35 ' provided at a first end 36 ' in the ram body 25 is used. Furthermore, the further anti-rotation pin 35 ' at a second end 37 ' in the housing part 3 used. The anti-rotation pin 35 ' is according to the anti-rotation pin 35 configured and has a bending section 40 ' on. In particular, by the bending section 40 ' also allows the spring section 35 ' a stroke compensation during operation of the high-pressure pump 1 , Furthermore, the anti-rotation pin acts 35 ' with the anti-rotation pin 35 together to ensure an anti-rotation, in particular an at least substantially coaxial alignment of the axis 32 the role 27 guaranteed. The anti-rotation pin 35 is on a first page 41 of the cam 10 arranged while the anti-rotation pin 35 ' on a second page 42 of the cam 10 is arranged. Thus, the anti-rotation pins 35 . 35 ' on different sides 41 . 42 of the cam 10 arranged. When an effect of the by the anti-rotation pins 35 . 35 ' Guaranteed anti-rotation thus results in an at least substantially symmetrical force introduction into the plunger body 25 , Furthermore, they are at a periodic stroke on the plunger body 25 acting forces coming from the anti-rotation pins 35 . 35 ' going out, at least essentially in the direction of the axis 14 , that is directed in the radial direction. This can change the performance of the pump assembly 11 possibly be favorably influenced.

3 shows an anti-rotation pin 35 ' a high pressure pump 1 according to a third embodiment of the invention. The anti-rotation pin 35 can be configured in a corresponding manner. In this embodiment, the anti-rotation pin 35 ' an at least substantially right-angled kink 43 on. Further, between the kink 43 and the second end 37 ' an elastic spring section 39 provided in which the anti-rotation pin 35 ' a spring element 44 having. The spring element 34 allows both a bend and a certain change in length of the anti-rotation pin 35 ' to the occurring stroke movement of the plunger body 25 compensate.

4 shows an anti-rotation pin 35 ' a high pressure pump 1 according to a fourth embodiment. In this embodiment, the anti-rotation pin 35 ' in the spring section 39 that between the kink 43 and the second end 37 ' is arranged, a wave-shaped configuration, which both a certain change in length of the mounted anti-rotation pin 35 ' in the direction of the axis 14 ( 2 ) as well as some bending of the anti-rotation pin 35 ' allows.

The at the high pressure pump 1 The rotation of the described embodiments provided has the advantage that it is designed kraftschluss and thus can work without wear. In this case, a good fatigue strength can be ensured with a large stroke. Another advantage is that a constructive effort to realize the rotation is relatively low and cost-effective components can be used, which provide a clean adhesion for the rotation. The anti-rotation pins 35 . 35 ' Depending on the arrangement, they can be subjected to tension, pressure or both tension and pressure. Especially with the in the 2 to 4 shown anti-rotation pins 35 . 35 ' is a stress on both train and on pressure of advantage. This allows a compact, ie design-saving, interpretation of the anti-rotation pins 35 . 35 ' be achieved.

The Invention is not limited to the described embodiments limited.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102005046670 A1 [0002, 0003]

Claims (15)

High pressure pump ( 1 ), in particular radial or inline piston pump for fuel injection systems of air-compressing, self-igniting internal combustion engines, with at least one pump assembly ( 11 ) and a drive shaft ( 6 ), which at least one of the pump assembly ( 11 ) associated cam ( 10 ), wherein the pump assembly ( 11 ) one on the cam ( 10 ) running role ( 27 ) and a roller shoe ( 26 ) having the role ( 27 ), characterized in that at least one anti-rotation pin ( 35 ) is provided, on the one hand at least indirectly with the roller shoe ( 26 ) is in operative connection and on the other hand at least indirectly with a housing part ( 3 . 4 . 5 ) is in operative connection. High-pressure pump according to claim 1, characterized in that the anti-rotation pin ( 35 ) at a first end ( 36 ) in the roller shoe ( 26 ) is used. High-pressure pump according to claim 1 or 2, characterized in that the anti-rotation pin ( 35 ) at a first end ( 36 ) with the roller shoe ( 26 ) connected is. High-pressure pump according to one of claims 1 to 3, characterized in that the anti-rotation pin ( 35 ) at a first end ( 36 ) at least in sections into a tappet body ( 25 ) of the pump assembly ( 11 ), which is connected to the roller shoe ( 26 ) connected is. High-pressure pump according to one of claims 1 to 4, characterized in that the anti-rotation pin ( 35 ) at a first end ( 36 ) with a tappet body ( 25 ) of the pump assembly ( 11 ) connected to the roller shoe ( 26 ) connected is. High-pressure pump according to one of claims 1 to 5, characterized in that the anti-rotation pin ( 35 ) at a second end ( 37 ) in the housing part ( 3 . 4 . 5 ) is used. High-pressure pump according to one of claims 1 to 6, characterized in that the anti-rotation pin ( 35 ) at a second end ( 37 ) with the housing part ( 3 . 4 . 5 ) connected is. High-pressure pump according to one of claims 1 to 7, characterized in that the anti-rotation pin ( 35 ) at least one bending section ( 40 ), on which the anti-rotation pin ( 35 ) is bendable. High-pressure pump according to one of claims 1 to 8, characterized in that the anti-rotation pin ( 35 ) at least one elastic spring portion ( 39 ) having a bend and / or a change in length of the anti-rotation pin ( 35 ). High-pressure pump according to claim 9, characterized in that the anti-rotation pin ( 35 ) on the elastic spring section ( 39 ) a spring element ( 44 ) having. High-pressure pump according to claim 9, characterized in that the anti-rotation pin ( 35 ) on the elastic spring section ( 39 ) is configured at least approximately wave-shaped. High-pressure pump according to one of claims 1 to 11, characterized in that the anti-rotation pin ( 35 ) has a relatively low rigidity. High-pressure pump according to one of claims 1 to 12, characterized in that the anti-rotation pin ( 35 ) at a near the pump assembly ( 11 ) lying position with the housing part ( 3 . 4 . 5 ) is in operative connection. High-pressure pump according to one of claims 1 to 12, characterized in that the anti-rotation pin ( 35 ) in sections around the drive shaft ( 6 ) and that the anti-rotation pin ( 35 ) on one of the pump assembly ( 11 ) remote location with the housing part ( 3 . 4 . 5 ) is in operative connection. High-pressure pump according to one of claims 1 to 14, characterized in that the anti-rotation pin ( 35 ) at least substantially on a first page ( 41 ) of the cam ( 10 ) of the drive shaft ( 6 ) is arranged that another anti-rotation pin ( 35 ' ) is provided and that the. further anti-rotation pin ( 35 ' ) at least substantially on a second side ( 42 ) of the cam ( 10 ) of the drive shaft ( 6 ) is arranged.