DE102014211472A1 - Fluid pump - Google Patents

Abstract

Fluid feed pump, comprising a pump housing (3) with two at least approximately v-shaped pump elements (2) whose pump piston (9) via a plunger (7) with a in the pump housing (3) rotatably mounted pump drive shaft (5) cooperate, wherein the Stroke (7) of each pump element (2) delimits a plunger space (19), and the two plunger chambers (19) via a connecting line (18) are interconnected, and wherein each pump element (2) via a inlet valve (16) fluid-fillable pump working space ( 15). According to the invention, a fluid delivery pump is specified in which the function of the fluid delivery device is improved with little effort. This is achieved in that the connecting line (18) via a connection line (20) to the inlet valves (16) or to the inlet valve (16) belonging fuel inlet valve chamber (23) is flow-connected and in particular at a partial load promotion, the inlet valve (16) of the ausschiebenden Pump element (2) can be opened.

Description

The invention relates to a fluid delivery pump, comprising a pump housing with two at least approximately V-shaped pump elements whose pump pistons cooperate via a plunger with a rotatably mounted in the pump housing pump drive shaft, wherein the plunger of each pump element delimits a plunger space, and the two plunger chambers via a connecting line connected to each other, and wherein each pump element has a fluid-fillable via an inlet valve pump working space. Furthermore, the invention relates to a method for operating such a fluid delivery pump.

State of the art

Such a fluid delivery pump is from the DE 10 2011 082 704 A1 known. This fluid delivery pump is designed as a high-pressure fuel pump for an injection system on an internal combustion engine. The high-pressure fuel pump has a pump housing with two approximately V-shaped pump elements. The pump pistons of the two pump elements cooperate via a respective roller tappet with a camshaft having a double cam and are moved in opposite directions up and down by the v-shaped arrangement during a rotational movement of the camshaft. In order to achieve a pressure equalization and volume compensation between the plunger chambers of the two pump elements, a connecting line is provided, which connects the two plunger chambers together.

The invention is based on the object to provide a fluid delivery pump and a method for operating a fluid delivery pump, which improves the function of the fluid delivery device with little effort.

Disclosure of the invention

This object is achieved in that the connecting line via a connection line with the intake valves or to the intake valves associated fuel inlet valve spaces is fluidly connected. The corresponding method for operating the fluid delivery pump provides that the pump working space of the ausschiebenden pump element with the pump working space of the pump element to be filled is connectable. In this case, according to the method claim, the connection can first be made in any desired manner.

In a further development of the invention, the inlet valves of the pump elements are connected via a connection line with the connecting line and the inlet valve of the ausschiebenden pump element can be opened during the delivery stroke. As a result, in addition to the normal filling of the pump working space to be filled from a low-pressure line with a low-pressure pump used, a filling can take place from the ejecting pump element. In this case, an efficient filling of the pumping work space to be filled is already achieved in normal operation by a filling support of the priming pump element due to the incoming flow and pressure wave coming from the ram spring chamber of the momentarily conveying pump element and the basic inlet connection of the inlet valve of the pump element to be filled is shown.

In a further embodiment of the invention, the opening of the inlet valve of the conveying pump element takes place at a partial load and consequently only a partial load delivery of the conveying pump element. As a result, there is no impairment of the delivery volume, for example, in a high-pressure accumulator of the promotional pump element.

The connection line is embedded in a further embodiment of the invention in a pump cylinder head and a pump housing. This embodiment is structurally and manufacturing technology easily implemented.

In a further development of the invention, the connection line as well as the connection line is throttle-free. This allows the bulk wave and pressure wave of the ausschiebenden pump element hydraulically well throttled move to the pump working space of the suctioning pump element.

In a further embodiment of the invention, an engine room of the fluid delivery pump is connected via a supply line to the connecting line. In this case, a fluid supply from a low-pressure circuit in the engine room of the fluid pump and from there via the supply line into the connecting line. As a result, a manufacturing technology easily implementable supply of the pump elements with fluid is made possible in which no additional line to the connection line.

In a further development of the invention, it is provided that the fluid feed pump is a high-pressure fuel pump. Although the object of the invention is applicable to any fluid pump for promoting any fluid, the preferred application is given in a high-pressure fuel pump, which promotes fuel as fuel, for example diesel fuel, preferably in a high pressure accumulator of a common rail injection system.

• – Es wird zunächst einmal eine bekannte Füllunterstützung des ansaugenden Hochdruckpumpenelements aufgrund der zulaufenden Mengenwelle und Druckwelle, kommend aus dem Stößelraum des momentan fördernden Hochdruckpumpenelements sowie durch die grundsätzliche Zulaufanbindung des zu befüllenden Pumpenelements dargestellt,
• – insbesondere bei Teillast kann eine zusätzliche Füllunterstützung des ansaugenden Pumpenelements aufgrund der Teilmengenrückförderung des ausschiebenden teilfördernden Pumpenelements erfolgen, wobei sich die Mengenwelle und Druckwelle des ausschiebenden Pumpenelements vorzugsweise hydraulisch gut entdrosselt und in Vorzugsrichtung auf das ansaugende Pumpenelement zubewegt,
• – es ist eine sehr schnelle Entlüftung der Fluidförderpumpe möglich,
• – es ist eine verbesserte Kühlung und Schmierung der Pumpenantriebskomponenten durch eine optimierte Einleitung der aus einem Tank geförderten Niederdruckmenge in den Triebwerksraum der Fluidförderpumpe möglich,
• – es besteht ein reduzierter Zerspannungsaufwand an dem Pumpengehäuse,
• – die Kanäle der Saugventilzulaufbohrungen können vorzugsweise so zu der Verbindungsleitung angeordnet sein, dass kein Pilotwerkzeug für die Saugventilzulaufbohrungen erforderlich ist und
• – es wird eine Reduzierung von Druckspitzen im Zulaufbereich und Rücklaufbereich der Kraftstoffförderpumpe erreicht, wobei weitere Komponenten des Kraftstoffeinspritzsystems geringeren hydraulischen Belastungen ausgesetzt sind beziehungsweise weniger in eine hydraulische Wechselwirkung mit der Kraftstoffhochdruckpumpe treten.

In summary, the following advantages are achieved with the high-pressure fuel pump according to the invention or the method for operating the high-pressure fuel pump.

• - It is first of all a known Füllunterstützung the aspirating high-pressure pump element due to the incoming Mengenwelle and pressure wave, coming from the plunger chamber of the currently promoting high-pressure pump element and by the basic inlet connection of the pump element to be filled,
• - Especially at partial load, an additional filling support of the priming pump element due to the partial amount of promotion of ausschiebenden partially promoting pump element done, with the bulk wave and pressure wave of the ausschiebenden pump element preferably well throttled hydraulically and moves in the preferred direction to the priming pump element,
• - It is a very fast venting of the fluid delivery pump possible,
• An improved cooling and lubrication of the pump drive components is possible by an optimized introduction of the low pressure quantity conveyed from a tank into the engine room of the fluid feed pump,
• There is a reduced machining effort on the pump housing,
• The channels of the Saugventilzulaufbohrungen may preferably be arranged to the connecting line, that no pilot tool for the Saugventilzulaufbohrungen is required and
• - It is achieved a reduction of pressure peaks in the inlet area and return area of the fuel delivery pump, with other components of the fuel injection system are exposed to lower hydraulic loads or less occur in a hydraulic interaction with the high-pressure fuel pump.

Further advantageous embodiments of the invention are described in the drawings, are described in more detail in the embodiments illustrated in the figures.

Show it:

1 a schematic sectional view through a v-shaped fluid pump in a first embodiment and

2 a schematic sectional view through a v-shaped fluid pump in a second embodiment.

In the 1 shown sectional view through a fluid delivery pump relates to a high-pressure fuel pump 1 , which is designed in particular for a common rail injection system, which is installed on an internal combustion engine. The common-rail injection system points next to the high-pressure fuel pump 1 a tank, which is connected via a low-pressure line with built-in filter device and low-pressure pump to the high-pressure fuel pump. The fuel tank becomes the high-pressure fuel pump 1 Fuel supplied by the high-pressure fuel pump 1 is conveyed into a high-pressure accumulator. From the high-pressure fuel accumulator, stored fuel from fuel injectors for controlled injection into associated combustion chambers of the internal combustion engine is taken there at a pressure of up to 3000 bar.

The high-pressure fuel pump 1 is V-shaped and has two pump elements 2 on that in a pump housing 3 the high-pressure fuel pump 1 are installed. The pump housing 3 closes an engine room 4 in which a camshaft having a double cam 5 is rotatably mounted. With the double cam of the camshaft 5 each act a roller 6 a roller plunger 7 together, in a cylindrical housing recess 8th of the pump housing 3 is used. The roller plunger 7 is in the housing recess 8th slidably guided. On the roller tappet 7 supports a pump piston foot 10 a pump piston 9 of the pump element 2 from. The pump piston foot 10 is about a pushrod disc 11 from a pestle spring 12 Opposite to a pump cylinder head 13 of the pump element 2 supports, against the roller tappet 7 pressed so that the roller 6 is in permanent contact with the tread of the double cam.

The pump piston 9 is in one piece with the pump cylinder head 13 trained pump cylinder 14 guided. Above the pump piston 9 is a pump workroom 15 in the pump cylinder head 13 let in, with the pump workspace 15 with an inlet valve 16 and an exhaust valve 17 interacts. About the inlet valve 16 becomes during a downward movement of the pump piston 9 Fuel from the low pressure line into the pump work space 15 introduced, which in a subsequent upward movement of the pump piston 9 via the outlet valve 17 is conveyed into the high-pressure accumulator.

In the pump housing 3 is a connection line 18 let in, the two in the respective housing recess 8th through the roller tappets 7 on the camshaft 5 opposite side limited plunger spaces 19 connects with each other. As a result, in each case in the opposite direction upward movement and downward movement of the pump piston 9 and the roller plunger 7 one Pressure equalization and a volume compensation in the ram spaces 19 , Between the plunger room 19 and the engine room 4 follows a volume compensation and pressure compensation via a hydraulic bypass 22 for example, as a hole in the roller tappet 7 is trained.

In addition, the connection line 18 via one into the pump housing 3 and the pump cylinder head 13 of the respective pump element 2 taken in connection line 20 with the respective inlet valve 16 or a part of the inlet valve 16 forming fuel inlet valve chamber 23 connected. As a result, that of the promotional pump element in the plunger space 19 caused mass wave and pressure wave to the opposite fuel inlet valve space 23 the inlet valve 16 of the pump element to be filled 2 directed. This alone is a filling support of the pump work space to be filled 15 in addition to the filling of the inlet valve 16 by suitably in this embodiment directly with the inlet valve 16 or the fuel inlet valve space 23 connected low-pressure line.

In addition, in particular at a partial load promotion of the opposite pump element 2 during the delivery stroke the associated inlet valve 16 , which may be actuated electromagnetically, for example, is opened by this pump element 2 subsidized fuel via the two connection lines 20 and the enclosed connection line 18 ultimately into the opposite pump workspace 15 initiated for further filling support.

In the embodiment according to 2 is the connection line 18 via a supply line 21 with the engine room 4 the high-pressure fuel pump 1 connected. In this embodiment, the from the low pressure pump from the tank of the high pressure pump 1 fed fuel into the engine room 4 so that supplied fuel is also used for efficient lubrication and cooling in the engine room 4 arranged engine parts is used. From the engine room 4 the fuel to be delivered then continues via the supply line 21 , the connection line 18 and the respective connection line 20 over the respective inlet valve 16 into the pump workroom 15 brought in. This further simplifies the machining of the pump housing 3 and the pump cylinder head 13 achieved by the elimination of other lines or channels.

• – Bei einer bekannten Kraftstoffhochdruckpumpe 1 erfolgt eine begrenzte Füllung der Pumpenelemente 2 bei mittleren und hohen Drehzahlen aufgrund interner hydraulischer Drosselstellung mit der Folge, dass die Kraftstoffhochdruckpumpe 1 prinzipiell großvolumiger ausgeführt werden muss, um Mengenbilanzen zu erfüllen. Eine großvolumigere Kraftstoffhochdruckpumpe 1 bringen die bekannten Nachteile mit sich, wie größere Antriebsmomente, Spitzendrehmomente, hydraulische Pulsationen und erhöhte Umpumpverluste,
• – Bei einer bekannte Kraftstoffhochdruckpumpe 1 besteht eine schlechte Entlüftung des Triebwerksraum 4 einschließlich einer schlechten Kühlung der Triebwerkskomponenten,
• – Bei einer bekannten Kraftstoffhochdruckpumpe 1 werden Pulsationen in das gesamte Kraftstoffeinspritzsystem eingeleitet und
• – Bei einer bekannten Kraftstoffhochdruckpumpe 1 ist der Zerspannungsaufwand zur Generierung des hydraulischen Kreislaufs in der Kraftstoffhochdruckpumpe 1 hoch.

Due to the inventive design and the operation of the invention, the high-pressure fuel pump 1 the following disadvantages associated with known solutions are avoided:

• - In a known high-pressure fuel pump 1 there is a limited filling of the pump elements 2 at medium and high speeds due to internal hydraulic throttle position with the result that the high-pressure fuel pump 1 in principle must be carried out large volume to meet mass balances. A larger-volume high-pressure fuel pump 1 bring the known disadvantages, such as larger drive torques, peak torques, hydraulic pulsations and increased pumping losses,
• - In a known high-pressure fuel pump 1 there is a poor ventilation of the engine room 4 including poor cooling of the engine components,
• - In a known high-pressure fuel pump 1 pulsations are introduced into the entire fuel injection system and
• - In a known high-pressure fuel pump 1 is the Zerspannungsaufwand for generating the hydraulic circuit in the high-pressure fuel pump 1 high.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011082704 A1 [0002]

Claims (9)

Fluid delivery pump, comprising a pump housing ( 3 ) with two at least approximately V-shaped pump elements ( 2 ), whose pump pistons ( 9 ) via a pestle ( 7 ) with a in the pump housing ( 3 ) rotatably mounted pump drive shaft ( 5 ), the plunger ( 7 ) of each pump element ( 2 ) a ram space ( 19 ), and the two plunger spaces ( 19 ) via a connecting line ( 18 ), and wherein each pump element ( 2 ) via an inlet valve ( 16 ) fluid-fillable pump work space ( 15 ), characterized in that the connecting line ( 18 ) via a respective connection line ( 20 ) with the inlet valves ( 16 ) or one to the respective inlet valve ( 16 ) belonging fuel inlet valve space ( 23 ) of the two pump elements ( 2 ) is fluidly connected. Fluid delivery pump according to claim 1, characterized in that the connection line ( 20 ) in a pump cylinder head ( 13 ) and the pump housing ( 3 ) is admitted. Fluid delivery pump according to claim 1 or 2, characterized in that the connection line ( 20 ) throttle-free is formed. Fluid delivery pump according to one of the preceding claims, characterized in that an engine room ( 4 ) of the fluid delivery pump via a supply line ( 21 ) with the connecting line ( 18 ) connected is. Fluid feed pump according to one of the preceding claims, characterized in that the fluid feed pump is a high-pressure fuel pump ( 1 ). Method for operating a fluid delivery pump, comprising a pump housing ( 3 ) with two at least approximately V-shaped pump elements ( 2 ), whose pump pistons ( 9 ) via a pestle ( 7 ) with a in the pump housing ( 3 ) rotatably mounted pump drive shaft ( 5 ), the plunger ( 7 ) of each pump element ( 2 ) a ram space ( 19 ), and the two plunger spaces ( 19 ) via a connecting line ( 18 ), and wherein each pump element ( 2 ) via an inlet valve ( 16 ) fluid-fillable pump work space ( 15 ), characterized in that the pump work space ( 15 ) of the projecting pump element ( 2 ) with the pump work space ( 15 ) of the pump element to be filled ( 2 ) is connectable. Method according to claim 6, characterized in that the intake valves ( 16 ) or to the respective intake valve ( 16 ) belonging fuel inlet valve spaces ( 23 ) of the pump elements ( 2 ) via a respective connection line ( 20 ) with the connecting line ( 18 ) and that the inlet valve ( 16 ) of the projecting pump element ( 2 ) can be opened during the delivery stroke. A method according to claim 7, characterized in that the opening of the inlet valve ( 16 ) takes place at a partial load promotion. Method according to one of the preceding claims, characterized in that a fluid feed into an engine room ( 4 ) of the fluid pump and from there via a supply line ( 21 ) in the connecting line ( 18 ) he follows.

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