WO2018134193A1

WO2018134193A1 - Pressure regulator for a common fuel line of a high pressure injection system

Info

Publication number: WO2018134193A1
Application number: PCT/EP2018/050994
Authority: WO
Inventors: David Lacroix; Raphael Combe
Original assignee: Robert Bosch Gmbh
Priority date: 2017-01-18
Filing date: 2018-01-16
Publication date: 2018-07-26
Also published as: FR3061935A1

Abstract

The invention relates to a pressure regulator (1), which is combined with a common fuel line (4) having an electromagnetic valve (2 and 3) having a pressure threshold value, the input (22) of which is connected to the high pressure chamber (42) and the output of which opens into a relief chamber (14), which is connected to the fluid return (15). The valve seat (24) is covered by a beam regulation element (25), which forms a regulating chamber (251) together with the valve seat (24). The beam regulation element (25) is traversed by an opening (252) in order to connect the regulating chamber (251) and the relief chamber (14) and to orient the return fluid flow lines through the opening (252) and to generate a stabilization pressure of the flow in the regulation chamber (251).

Description

Pressure regulator for a common fuel line a

High-pressure injection system

Field of the invention

The present invention relates to a pressure regulator, which is combined with a common fuel line of a high-pressure injection system, which supplies an internal combustion engine, wherein the regulator comprises an electromagnetic valve with a pressure threshold whose input is connected to the high pressure chamber of the fuel line and its output in a Relief chamber opens, which is connected to the liquid return, wherein the valve has a body through which a channel, whose input is connected to the high-pressure chamber and whose outlet opens through the valve seat in the discharge chamber, and a closure member in the form of a ball, the is carried by the end of the rod, which is firmly connected to the electromagnet core and traverses the cavity.

State of the art

Such a pressure regulator is known for common diesel fuel rail systems. So far, this type of regulator has been used primarily as a controlled relief valve and less as a pressure regulator as such.

Today, it is being used more and more to regulate the common rail pressure in an ever-increasing pressure / flow range in a stable manner, for example, for heating the diesel fuel in the recirculation loop to avoid paraffinizing the diesel fuel filter.

In this case, the stability of the pressure of the fuel pipe, which is regulated by the regulator, must be strongly promoted since it is indirectly caused by the environmental standards. Various design improvements for increasing the stability of the regulated by the regulator pressure are described in the documents DE 10 2007 013 525 and DE 10 2013 222 483 of the applicant.

Increasing the pressure in the common fuel line of the last generation systems operating at pressures of 2500-2700, even 3000 bar, also leads to ever greater miniaturization of the geometry of the valve body. The fine geometry of this part has a major influence on the flow of the fluid, which relieves itself of the high pressure for return through the seat of the valve body. Even a minimal change in the flow lines downstream of the passage section of the seat of the valve body directly affects the resulting hydraulic force applied to the ball / rod assembly and, consequently, the balance of forces: the hydraulic force applied by pushing on the ball / rod assembly. Assembly opens and the magnetic force of the electromagnet, which counteracts this. The regulated fuel line pressure can thus be directly influenced. More particularly, the return zones consisting of vortices may themselves appear to depend very much on the average pressure downstream of the recirculation loop, and thus this constitutes a potential source of variations in the total hydraulic force exerted on the rod / ball assembly.

Hydraulic simulations have shown that different types of flows could be present at the valve outlet for a range of increased flow / pressure.

These types of flows are a function of the distribution of downstream pressure around the ball / bar assembly, which alters the resultant force and produces non-linearity effects of the hydraulic force. This non-linearity creates pressure instabilities of the regulated fuel rail.

The document DE 10 2012 111106 describes and represents an electromagnetic pressure regulator whose valve seat 11, which cooperates with the closure member 12, is provided with fixed blades 18a, b, c, d of very complex shape, radially the valve seat in the discharge chamber extend. This very complex shape of the valve seat and its extension is intended to improve the flow by reducing the turbulence of the valve seat, which in turn is widened according to a curved cross-section. The end of the rod of the electromagnet carries the ball that forms the lock. she will passed through the edges of the fixed blades on the axial inner side. But this solution would be too expensive to industrialize due to the complexity of its geometry and would not be suitable for automotive applications.

Object of the invention

The object of the present invention is to develop a pressure regulator which makes it possible to have additional stability in a pressure / flow capacity, with reduced economic means compatible with the aim of this regulator.

Presentation and advantages of the invention

To this end, the invention has as subject matter a pressure regulator of the type defined above, characterized in that the valve seat is covered with a jet regulator element forming a regulation chamber with the valve seat, this jet regulator element being traversed by at least one passage connecting the regulation chamber and the discharge chamber which is connected to the discharge fluid exit to orient the liquid flow lines through the passage and to produce a stabilizing pressure of the flow in the regulation chamber.

The cross-section of the passage between the regulation chamber and the discharge chamber at the exit creates a pressure drop to create a pressure inside the regulation chamber. This pressure is stabilized by this jet regulator member, which directs the hydraulic flow directly downstream of the flow near the ball / rod assembly and significantly reduces the effects of hydraulic flow fluctuations. This results in a strong improvement in stability in an even greater pressure / flow functional area than the current one.

The shape of the jet regulator member is advantageously very simple, being adaptable by the washer according to the various structures of the body of the regulator for adjustment to the gap according to each case / application. The invention considerably simplifies the execution of a pressure regulator that corresponds to various functional parameters. Thus, the pressure regulators of various series are manufactured according to the applications with jet regulator bodies corresponding to each application.

According to another advantageous feature, the jet regulator member which covers the valve seat is a plate which is applied to the surface of the valve body around the valve seat, this plate being provided with a recess forming the regulation chamber which communicates with the discharge chamber through at least one Passage is connected.

According to another advantageous feature, the jet regulator element is traversed by the rod of the electromagnet which carries the closure member of the valve, leaving a passage for the discharge liquid.

According to a further advantageous feature, the jet regulating element comprises an opening which is traversed by the rod of the electromagnet carrying the closing member and at least one other opening which thus connects the regulating chamber to the discharge chamber.

The annular passage cross-section defined between the outer diameter of the rod in the regulation position and the diameter of the central opening of the jet regulator element and the adapted cross-section of any other openings create an optimal pressure drop for generating a pressure inside the regulation chamber. Other peripheral openings may be added to orient other flow lines of the recirculation flow and adjust the pressure drop depending on the stroke of the rod. The other openings are advantageously distributed symmetrically about the axis.

The shape of the jet regulator body and the inner contour of the volume, the number, size and shape of the openings are optimized by simulation depending on the geometry of the other parts of the valve body and the rod.

The Strahlreguliererorgan is advantageously a metallic part. The invention also relates to the combination formed from a pressure regulator, as defined above, and a common fuel line of a high-pressure injection system.

drawings

The present invention will be described in more detail below with the aid of two embodiments of a pressure regulator, which are illustrated in the accompanying drawings, in which:

Fig. 1 is an axial section of a first embodiment of a pressure regulator according to the invention,

Fig. 1a is a sectional view of the pressure regulator shown opposite the end of the common rail where it is installed;

Fig. 1b is an enlarged scale view of the front end of the pressure regulator, shown in section, showing the valve separate from the receptacle in which it is installed at the end of the body of the regulator;

Fig. 2 is an axial sectional view of the second embodiment of the pressure regulator, which is limited to the front end of the pressure regulator.

Description of embodiments of the invention

According to Fig. 1 and the detailed views of Fig. La, lb, the invention as subject matter has a pressure regulator 1, which is provided with a valve 2, which is controlled by an electromagnet 3, said regulator having a common fuel line 4 of an injection system of fuel is combined under high pressure in an internal combustion engine.

Only the end of the common rail 4 receiving the pressure regulator 1 is shown.

The components 1, 2, 3, 4 of the assembly thus formed have at least partially a rotational symmetry about the axis XX. The pressure regulator 1 regulates the high pressure in the common rail 4 to a target pressure by opening to discharge the relief liquid from the high-pressure chamber 42.

Referring to Figures 1, la, the common rail 4 is formed of a cylindrical body 41 with a thick wall axis XX which surrounds the high pressure chamber 42 having its outlets connected to the high pressure injectors and having an inlet connected to the high pressure pump of the engine ,

The body 41 comprises a receptacle 43, which opens on the outside through an inlet 44, which is provided with an internal thread 441 in order to screw the pressure regulator 1. The receptacle 43 forms a shoulder 431 at its junction with the opening of the chamber 42 in order to realize a sealing system for the regulator 1. The receptacle 43 also has an outlet 45 for the liquid of the fuel line 4, which passes through the regulator 1. The outlet 45 is connected to the fuel reservoir.

According to FIGS. 1 a, 1 b, the pressure regulator 1 has a cylindrical body 11, through which an axial bore 12 runs, which on the side of the common fuel line into a cavity 13, which receives the valve 2, by means of a discharge chamber 14 with a diameter , which is greater than that of the bore 12, which is connected by radial bores 15 with the return line 45 of the common fuel line 4, opens.

At the other end, the body 11 has a receptacle 16 for the electromagnet 3, which is closed by a lid 161 which is pressed into the body (111) and is itself covered by a connecting element 17 which is connected to the electromagnet 3 by a non Wiring shown connected.

The valve 2 consists of a valve body 21 in the form of a plate, which is traversed by an axial channel 22, whose input is on the side of the common rail 4 in a nozzle 21 which is covered with a filter 23 in the form of a cap. The channel 22 opens into a valve seat 24 with a conical shape. The surface 21 a of the body 21, into which the seat 24 opens, is covered with a plate 25, which forms a regulation chamber 251 above the valve seat 24 and is provided with an opening 252. This plate 25 is generally at the bottom 131 of the receptacle 13 with Zwischenfügung an annular fitting 26th supported, which leaves the opening 252. This fitting 26 makes it possible to compensate for the various adjustments of valves and electromagnets for one and the same body 11 of the pressure regulator. The plate 25, which forms a discharge substance jet regulator element exiting the valve 2, thus limits the regulation chamber 251.

The valve 2 has a closure member 27 in the form of a ball, which is supported by the conical end 321 of the rod 32 of the electromagnet 3.

The other side 21 b of the body 21 has a sealing edge 212 to be applied to the shoulder 431 of the receptacle 43 and to realize a tight separation for the operating pressure of the common rail, so that the transmission of liquid to the output only via the channel 22 of the valve 2 can take place.

The opening 252 is traversed by the conical end 321 of the rod of the electromagnet, while leaving a circular space connecting the regulation chamber 251 with the discharge chamber 14. The plate 25 breaks the jet of liquid at the exit of the valve seat 24 and creates in this regulation chamber 251 an intermediate pressure between the high pressure of the common rail 4 and the recirculation pressure in the unloading chamber 14, which is substantially equal to the ambient pressure, passing the discharge fluid through the opening of the valve 2 is released.

The free surface between the conical end 321 and the opening 252 increases as the valve opens and the conical end 321 recedes. The liquid that escapes from the valve 2 is inevitably directed to the opening 252, so that it arrives in the discharge chamber 14, then in the radial bores 15 to the return 45.

The solenoid 3, which controls the valve 2, has a core 31 carrying the rod 32, the conical end 321 of which is provided with the ball 27 constituting the closing member of the valve 2, as described above.

In this embodiment, the core 31 of the electromagnet 3 is a planar core, but without the invention being limited to this type of electromagnet core. The core 31 is fixedly connected to the rod 32, which slides in the bore 12 in the closing direction F of the valve 2 pushed by the electromagnet 3, which is controlled to regulate the high pressure to the target pressure. Since the liquid flow from the regulation chamber 251 must exit through the passageway which is exposed in the opening 252, it is itself stabilized, that is regulated, which attenuates the arrival of the relief fluid and the vibrations of the jet between the seat 24 and the ball 27 passes, dampens.

The core 31 is covered in the receptacle 16 by the cover 161, which is pressed into the receptacle 16 by the bent edges 111. The electromagnet has a coil 33 which is embedded in the body 11 of the pressure regulator. A return spring 34 is applied to the surface of the core 31, which is turned to the fuel line to act in the opening direction of the valve 2. This retraction movement of the core 31 and the rod 32 is limited by the fact that it comes to rest on the lid 161.

The pressure regulator 1 is fixed to the fuel line 4 by means of a nut 18 which freely surrounds the cylindrical body 11 and abuts a ring 181 which is in engagement with a groove 112 of the body 11.

The external thread 182 of the nut 18 is screwed into the internal thread 441 and the sealing edge 212 of the body 21 of the valve comes to rest against the surface of the shoulder 431 to ensure the tightness.

A seal 19 is also provided in a groove 112 to realize the tightness between the wall of the receptacle 43 and the body 11 for the liquid return, which exits from the radial bores 15 to the return line 45, which is integrated into the common fuel line 4 ,

In the pressure regulator 1 according to the invention, when the valve 2 is opened by the retraction of the rod 2 and the shutter 27 (opposite to the direction of closing F), the relief fluid flows under high pressure from the high pressure chamber 42 through the filter 23 and the passage 22 arrives between the ball 27 and the valve seat 24 and arrives in the regulation chamber 251, in which the liquid collects and dampens their movement, so as to be forcibly oriented in the opening 252 and to traverse the cross section passing through the conical End 321 is released. The liquid flow establishes an intermediate pressure between that of the high-pressure chamber 42 and the outlet pressure, which is practically at ambient pressure. This intermediate pressure regulates the flow exiting in the space between the opening 252 and the conical end 321 of the rod. This intermediate pressure makes it possible to reduce the turbulence at the exit of the seat 24. The relief flow is oriented to the open space between the rod 321 and the edge of the opening 252. This discharge fluid flow, which is so deflected, stabilizes the function of the regulator 1 and the common rail 4, the pressure of which is finely stabilized to the target pressure.

Fig. 2 shows another embodiment 2a of the pressure regulator 1. This embodiment differs from the previous one by the jet regulator element 25a, which is provided with an axial opening 252a for the end 321 of the rod 32 and openings 252b distributed around the axis in order to produce by their pressure drops a pressure of the regulation chamber 251 a, which stabilizes the pressure in the high pressure chamber 42 of the common rail 4. The orifices 252b are preferably distributed with rotational symmetry about the axis XX to regulate and distribute the relief flow to the relief chamber 14, while creating an intermediate level of pressure in the regulation chamber 251a. The number, dimensions and distribution of the flow passage cross sections of the various openings 251a, 251b are preferably defined by simulations.

The various embodiments are very simple and particularly adapt to any type of common rail pressure regulators.

Nomenclature pressure regulator

11 body

111 bent edge / pressfit

112 groove

113 groove

12 valve

13 cavity

14 discharge chamber

15 Radial bore

16 recording

161 lid

162 bent edge / pressfit

17 connecting element

18 mother

181 ring

182 thread

19 seal

25 beam regulator element / plate

25a another beam regulator element

251 Regulatory Chamber

251a regulatory chamber

252a opening

252b other opening

Valve

other valve

21 valve body

21a area of the valve body

21b other area

211 nozzles

22 axial channel

23 filters

24 valve seat

26 regulatory adapter

27 closure member

electromagnet 31 core

32 pole

321 conical end

33 coil of the electromagnet

34 return spring

Common fuel line

41 cylindrical body

42 high pressure chamber

43 recording

431 paragraph

44 entrance

441 female thread

45 output

Claims

claims

1. Pressure regulator, which is combined with a common fuel line of a high-pressure injection system, which supplies an internal combustion engine, wherein the regulator comprises an electromagnetic valve with a pressure threshold whose input is connected to the high pressure chamber of the fuel line and whose output opens into a discharge chamber with the liquid recycling is connected,

the valve having a body through which passes a channel whose inlet communicates with the high pressure chamber and whose outlet opens into the relief chamber through the valve seat, and a closure member in the form of a ball carried by the end of the rod integral with the valve The pressure regulator is characterized in that the valve seat (24) with a Strahlreguliererelement (25, 25 a) is formed, which forms a regulation chamber (251, 251 a), said Strahlreguliererelement (25, 25a) is traversed by at least one orifice (252, 252a, 252b) to communicate the regulation chamber and the relief chamber (14) to orient the liquid flow lines through the orifice (252, 252a, 252b) and Stabilization pressure of the flow in the regulation chamber (251, 251 a) to produce.

A pressure regulator according to claim 1, characterized in that the jet regulator element (25, 25a) covering the valve seat (24) is a plate which is applied to the surface (21a) of the valve body (21) around the valve seat (24) is and is provided with a recess which forms the regulation chamber (251) which is connected to the discharge chamber (14) through at least one opening (252).

3. Pressure regulator according to claims 1 and / or 2, characterized in that the Strahlreguliererelement (25, 25 a) of the rod (32, 321) of the electromagnet (3) is crossed, which carries the closure member (27) of the valve.

4. Pressure regulator according to one of claims 1 to 3, characterized in that the Strahlreguliererelement (25 a) has an opening (252 a), the is traversed by the rod of the electromagnet (32, 321) which carries the closure member (27) and at least one other aperture (252b) connecting the regulation chamber (251, 251a) to the relief chamber (14).

5. Pressure regulator according to claim 4, characterized in that the Strahlreguliererelement (25 a) comprises a plurality of openings (252 b) which are distributed rotationally symmetrically about the axial opening (252 a) which is traversed by the end of the rod (321), the closing member (25 27) of the valve (2) carries.