WO2014183907A2

WO2014183907A2 - Pump, in particular high-pressure fuel pump of an internal combustion machine

Info

Publication number: WO2014183907A2
Application number: PCT/EP2014/055363
Authority: WO
Inventors: Friedrich Boecking
Original assignee: Robert Bosch Gmbh
Priority date: 2013-05-15
Filing date: 2014-03-18
Publication date: 2014-11-20
Also published as: WO2014183907A3; DE102013209021A1

Abstract

The invention relates to a pump, in particular a high-pressure fuel pump of an internal combustion engine, having a pump cylinder (2), which is covered by a pump cylinder head (1) and in which a pump plunger (3) can be moved up and down in a translatory manner, wherein the pump plunger (3) together with the pump cylinder head (1) delimits a pump working chamber (4), which is connected via an inlet valve (5) to a low-pressure connection and via an outlet valve (6) to a high-pressure connection, and wherein the inlet valve (5) and the outlet valve (6) are arranged axially in relation to each other. According to the invention, a pump with an inlet valve (5) and an outlet valve (6) having good closing behaviour is provided. This is achieved in that the inlet valve (5) and the outlet valve (6) have a guided valve body (15, 15a).

Description

Title:

Pump, in particular high-pressure fuel pump of an internal combustion engine

The invention relates to a pump, in particular high-pressure fuel pump of an internal combustion engine, comprising a covered by a pump cylinder head pump cylinder in which a pump plunger is translationally movable up and down, the pump plunger together with the

Pump cylinder head delimits a pump work space that is over

Inlet valve is connected to a low pressure port and via an exhaust valve to a high pressure port, and wherein the inlet valve and the outlet valve are arranged axially to each other.

State of the art

Such a pump is known from DE 10 2009 027 273 AI. This designed as a high-pressure fuel pump has a pump cylinder head, in which in axial arrangement and extension to a pump plunger designed as a suction valve inlet valve and designed as a check valve outlet valve are recessed. The inlet valve is as

Ball valve formed and has a spring holder and a spring which holds the ball of the ball valve in a valve seat. The valve seat is in one

Inserted exhaust valve seat part of the exhaust valve. The spring holder protrudes into a pump working space of the high-pressure fuel pump. The disadvantage of this known suction valve is that, especially at high speeds, the closing behavior is problematic because the ball can migrate laterally and thus lead to a slower and uncontrolled closing behavior. The exhaust valve is guided with a guide part loose in an exhaust valve body, so that a valve body of the exhaust valve can migrate laterally. The invention has for its object to provide a pump with an inlet valve and an exhaust valve, which have a good closing behavior.

Disclosure of the Invention Advantages of the Invention

This object is achieved in that the inlet valve and the outlet valve have a guided valve body. In this case, the valve body can be designed in a general form as an arbitrarily designed guided valve body. The guidance of the valve body causes the valve body to be guided out of the valve seat or sealing seat, in particular at high rotational speeds, without lateral migration into the valve seat or sealing seat and out of the valve seat or sealing seat. As a result, an exact delay-free opening and closing of both the intake valve and the exhaust valve

ensured.

In a further development of the invention, the valve body has a conical sealing part and a guide part adjoining the cone tip. This embodiment is easily implemented in terms of manufacturing technology and also has a small space requirement.

In a development of the invention, the guide part has guide wings. In turn, in another embodiment of the invention, the guide part with the guide wings in an inlet valve seat part or

Outlet valve seat part out. At the same time is in the intake valve seat part

or the exhaust valve seat part each incorporated a seat, which cooperates with the conical sealing part of the valve body. The guide vanes, of which, for example, three or four are distributed on the circumference of the guide member, ensure reliable guidance of the guide member in a guide bore and allow in the area between the guide vanes unimpeded flow of the fluid controlled by the sealing member. In addition to the guide hole need in this Design edited only cooperating with the guide bore end faces of the guide wings, for example, be ground.

The pump may in principle be designed for delivery of any fluid, but is preferred for the promotion of fuel as

High-pressure fuel pump is formed. Such a high-pressure fuel pump delivers fuel supplied from a low-pressure circuit, for example diesel fuel or gasoline, into a high-pressure accumulator from which the fuel stored there is fuel! Njektoren for injection into associated combustion chambers of an internal combustion engine is removed.

In a further embodiment of the invention, the valve body on the

Cone base on a cylindrical stop. Again, in another embodiment, the stop a stop piece is arranged lying opposite. The stop and the stop piece limit the possible stroke of the valve body, wherein the maximum stroke is advantageously set so that the valve body remains in a control range of throttling.

At the same time form the stop and the stop piece turn in another embodiment of the invention, a guide for a valve spring, the

In the idle state, the valve body presses with the conical sealing part into the valve seat of the inlet valve seat part or of the outlet valve seat part.

In a further development of the invention, the stop piece of the inlet valve is inserted into an outlet valve seat part of the outlet valve. This embodiment contributes to a space-optimized design.

In a development of the invention, the inlet valve and the outlet valve have an at least largely identical structure. On the one hand, due to the largely identical structure, it is possible to install uniform components in both valves, for example a uniform valve spring and a uniform stop piece. Optimally, the components of the two valves are completely identical, so that assembly and stocking of the parts is simplified and minimized. In addition, by the similar or same structure a similar performance of the two valves guaranteed. This is advantageous for a reliable and reliable operation of the pump.

In a further development of the invention, the inlet valve seat part and the

Exhaust valve seat part with the other components of the respective valve inserted into a bore in the pump cylinder head and of a than

High-pressure fitting formed holding piece in the hole set. For this purpose, the holding piece preferably has an external thread, with which it is screwed into an internal thread in the bore. On the front side depressions, for example in the form of blind holes, can be incorporated in the holding piece, which make it possible to apply a tool. This embodiment also contributes to a compact construction of the intake valve and the exhaust valve. Incidentally, the end surfaces of the intake valve seat part and the exhaust valve seat part and the holding piece which cooperate with each other and with a base of the bore are machined as sealing surfaces which allow a fluid-tight seal with each other.

Further advantageous embodiments of the invention are the

See drawing description in which an embodiment of the invention is described in detail.

Brief description of the drawings

It shows:

1 shows a longitudinal section through a pump cylinder head as

High-pressure fuel pump designed pump with integrated inlet valve and exhaust valve.

Embodiment of the invention

Figure 1 shows an integrally formed with a pump cylinder head 1 pump cylinder 2 designed as a high-pressure fuel pump, in particular a common-rail injection system. Of the

High-pressure fuel pump is supplied by a low pressure system Fuel under high pressure in a high-pressure accumulator (rail) promoted, from which the fuel stored there is taken from fuel injectors for injection into the associated combustion chambers of an internal combustion engine. In the pump cylinder 2, a pump plunger 3 is translationally movable up and down. To generate the up and down movement, the pump plunger 3 cooperates with a Pumpenplungerfuss directly or with the interposition of a roller tappet with a cam track of a cam of a camshaft, the rotational movement up and down the

Pump plunger 3 generated. The camshaft is arranged in a pump housing to which the pump cylinder 2 is attached to the pump cylinder head 1, or the camshaft is arranged directly in an internal combustion engine, in which case the pump with the pump cylinder 2 and the

Pump cylinder head 1 directly into a housing part, for example the

Crankcase, the internal combustion engine is installed. In this case, the

Camshaft be extended by an injection cam gas exchange camshaft of the internal combustion engine.

The pump plunger 3 and the pump cylinder head 1 limit one

Pump working space 4, which is designed with a suction valve designed as inlet valve 5 and with a designed as a check valve outlet 6th

interacts. Via the inlet valve 5, a fluid in the form of a fuel, so for example diesel fuel or gasoline, introduced in the pump working chamber 4, which in an upward movement of the pump plunger 3 and closed inlet valve 5 via the outlet valve 6 and a

High-pressure port 7 in a designed as a high-pressure connector holding piece 8 in a connected to the high-pressure port 7

High-pressure line is promoted. The high pressure line is further connected to the high pressure accumulator, in which the subsidized fuel is introduced. The inlet valve 5 and the outlet valve 6 each have one

Inlet valve seat part 9 and an exhaust valve seat part 10, which are inserted axially one behind the other into a bore 11 in the pump cylinder head 1 and are held by the holding piece 8. For this purpose, the holding piece 8 a

External thread, which interacts with an internal thread in the bore. For screwing or unscrewing the holding piece 8 or in the hole has the holding piece next to the

High pressure port 7 arranged blind holes 12 into which a tool can be used. The end faces of the intake valve seat part 9 and the exhaust valve seat part 10 and a front-side abutment surface 13 of the

Pump cylinder head 1 in the region of the bore 11 as well as the outlet valve seat part 10 facing holding piece end face 14 are formed as sealing surfaces, which allow a liquid-tight seal with each other. Additionally or alternatively, a liquid or solid sealant can be installed in the region of the sealing surfaces.

The inlet valve 5 has a guided valve body 15 which consists of a conical sealing part 16, a guide part 17 adjoining the apex of the cone and an opposite cylindrical stop 18 arranged on the cone base side. The valve body 15 is connected to the

Guide member 17 is guided in a guide bore 19 in the inlet valve seat part 9 by means of guide vanes 20 which are arranged distributed on the circumference of the guide member 17. In the rest state, the sealing part 16 is pressed by a valve spring 22 into a corresponding sealing seat 21 of the inlet valve seat part 9. The valve spring 22 is supported on a stop member 23, which is used as a separate component in a recess 24 of the Auslaßventilsitzteils 10 and on the cone base surrounding the stop 18 from. The stop 18 and the opposite stop member 23 limit the possible stroke of the valve body 15th

The fuel is the intake valve 5 via a low pressure port forming inlet channel 25 in the pump cylinder head 1, a the

Inlet valve seat part 9 is supplied to surrounding annular space 26, an inlet valve seat part channel 27 and a central inlet valve space 28 before the guide part 17. The fuel then flows along with the intake valve 5 open

Guide wing 20 and along the conical sealing member 16 in the

Recess 24, which in turn through connecting holes 29 in the

Inlet valve seat part 9 is connected to the pump working space 4. Of the

Inlet valve space is further connected to a return 31, is discharged through the excess fuel. To limit the return amount can be used in the return 31, a throttle. After filling the pump working chamber 4, the inlet valve 5 closes and during a subsequent upward movement of the pump plunger 3, the fuel located in both the pump working chamber 4 and the recess 24 is supplied to the outlet valve 6, which also has a valve body 15a with a conical sealing part 16a, a guide part 17a and a stop 18a. The guide part 17 a further has guide vanes 20 a, which is guided in a guide bore 19 a in the outlet valve seat part 10 adjacent to the recess 24. Also in the case of the outlet valve 6, the sealing part 16a is pressed by a valve spring 22a into a corresponding sealing seat 21a of the outlet valve seat part 10 in the idle state. The valve spring 22a is supported on a stop member 23a, which is used as a separate component in a recess 24a of the retaining piece 8 and on the cone base surrounding the stop 18a. The stop 18a and the opposite stop member 23 also limit the possible stroke of the valve body 15a here.

The fuel flowing through the exhaust valve 6 passes into the as

High-pressure chamber acting recess 24 a, which is embedded in the retaining piece 8. In the holding piece 8, an outlet hole 30 is inserted, which forms the actual high-pressure outlet.

Claims

claims

1. Pump, in particular high-pressure fuel pump of an internal combustion engine, comprising one of a pump cylinder head (1) covered

Pump cylinder (2) in which a pump plunger (3) is translationally movable up and down, wherein the pump plunger (3) together with the

Pump cylinder head (1) a pump working space (4) limited, via an inlet valve (5) with a low pressure port and a

Exhaust valve (6) is connected to a high-pressure port (7), and wherein the inlet valve (5) and the outlet valve (6) are arranged axially to each other,

characterized in that the inlet valve (5) and the outlet valve (6) each have a guided valve body (15, 15a).

2. Pump according to claim 1,

characterized in that the valve body (15, 15a) has a conical sealing part (16, 16a) and a guide part (17, 17a) adjoining the apex of the sealing part (16, 16a).

3. Pump according to claim 2,

characterized in that the guide part (17, 17a) has guide wings (20, 20a).

4. Pump according to claim 2 or 3,

characterized in that the guide part (17, 17a) with the

Guide vanes (20, 20a) in an inlet valve seat part (9) and in an outlet valve seat part (10) is guided.

5. Pump according to one of claims 2 to 4,

characterized in that the valve body (15, 15a) on the

Cone base has a cylindrical stop (18, 18a).

6. Pump according to claim 5,

characterized in that the stop (18, 18 a) a stop piece (23, 23 a) is arranged opposite.

7. Pump according to claim 6,

characterized in that the stop (18, la) and the

Stop piece (23, 23 a) form a guide for a valve spring (22, 22 a).

8. Pump according to one of claims 6 or 7,

characterized in that the stop piece (23) in a

Exhaust valve seat part (10) of the exhaust valve (6) is recessed.

9. Pump according to one of the preceding claims,

characterized in that the inlet valve (5) and the outlet valve (6) have an at least substantially identical structure.

10. Pump according to one of the preceding claims,

characterized in that the inlet valve seat part (9) and the outlet valve seat part (10) are inserted into a bore (11) in the pump cylinder head (1) and fixed in the bore (11) by a holding piece (8) formed as a high pressure fitting.