WO2018202346A1

WO2018202346A1 - Metering device and method for production

Info

Publication number: WO2018202346A1
Application number: PCT/EP2018/056298
Authority: WO
Inventors: Jochen Wessner
Original assignee: Robert Bosch Gmbh
Priority date: 2017-05-05
Filing date: 2018-03-13
Publication date: 2018-11-08
Also published as: DE102017207577A1

Abstract

The invention relates to a metering device (1), comprising: an elongate nozzle body (2) having a cavity (3), which has a first end region (31) and a second end region (32); a fluid opening (4), which is arranged in the first end region (31), for conducting a fluid; a nozzle needle (5), which is arranged for axial sliding in the cavity (3), the nozzle needle (5) closing the fluid opening (4) when moved toward the first end region (31) and opening the fluid opening (4) when moved toward the second end region (32); a spring apparatus (6), which is arranged between a wall section (10) of the nozzle body (2) in the second end region (32) and the nozzle needle (5) and applies a preloading force to the nozzle needle (5) toward the first end region (31); and a magnet apparatus (7), which is designed to produce a magnetic field in such a way that the nozzle needle (5) can be moved toward the second end region (32) against the preloading force of the spring apparatus (6); the wall section (10) of the nozzle body (2) in the second end region (32) being deformable by application of force from outside in the axial direction in such a way that the preloading force of the spring apparatus (6) can be adjusted.

Description

DOSING DEVICE AND METHOD OF MANUFACTURING

The present invention relates to a metering device and a method for producing a metering device. In particular, the present invention comprises a metering device for a fuel cell.

State of the art

In fuel cell systems dosing come to adjust the

Amount of hydrogen used. The amount of hydrogen depends on a stroke of the valve needle of the metering valve. To ensure accurate adjustment and fine adjustment, the stroke of the dispensing needle must be precisely set. such

Metering valves are also used to inject fuel into engines.

The accuracy of the metering valve depends inter alia on manufacturing tolerances of the spring used, which exerts a biasing force on the dispensing needle. In order to allow an accurate adjustment, a method for controlling a fuel injection device is known from the document US 4610080 A, wherein the stroke of the dispensing needle is measured and depending on the measured stroke intermediate discs are used, which influence the biasing force.

Disclosure of the invention

The invention provides a metering device, in particular for a fuel cell, having the features of patent claim 1 and a method for producing a

Dosing device with the features of claim 10 ready.

According to a first aspect, the invention accordingly provides a metering device, in particular for a fuel cell, which has an elongate nozzle body with a cavity, the cavity having a first end region and a second end region. In the first end region is a fluid port to the line a fluid arranged. A nozzle needle is arranged axially displaceable in the cavity, wherein the nozzle needle closes the fluid opening when moving in the direction of the first end region and at least partially opens the fluid opening upon movement in the direction of the second end region. A spring means is disposed between a wall portion of the nozzle body in the second end portion and the nozzle needle and exerts a biasing force on the nozzle needle in the direction of the first end portion. A magnetic device is designed to generate a magnetic field in such a way that the nozzle needle is movable against the biasing force of the spring device in the direction of the second end region. The wall portion of the nozzle body is deformable in the end region by a force from the outside in the axial direction such that the biasing force of the spring device is adjustable.

According to a second aspect, the invention relates to a method for producing a metering device. An elongated nozzle body is provided having a cavity with a first end portion and a second end portion, wherein in the first end portion a fluid port is formed for conducting a fluid. A nozzle needle is provided which is axially slidably disposed within the cavity, the nozzle needle closing the fluid opening as it moves toward the first end region and opening the fluid opening upon movement toward the second end region. A spring device is disposed between a wall portion of the

Nozzle body disposed in the second end portion and the nozzle needle, wherein the spring means a biasing force on the nozzle needle in the direction of the first

Endbereich exerts. A magnetic device is arranged, which is designed to generate a magnetic field such that the nozzle needle is movable counter to the biasing force of the spring device in the direction of the second end region. For deforming the wall portion of the nozzle body, a force is exerted externally in the axial direction on the wall portion of the nozzle body in the second end portion to adjust the biasing force of the spring means. Preferred embodiments are the subject of the respective subclaims.

Advantages of the invention

The invention provides a metering device which is easily adjustable in operation, so that error tolerances in the production easily after installation of the Metering device can be compensated. Thus, by exerting a pressure or force on the wall section, a technician can increase the biasing force which the spring device exerts on the nozzle needle and thereby influence the stroke of the nozzle needle.

For this purpose, the wall section is preferably deformable in such a way that even after

Termination of the force stops the deformation. Thus, the invention allows to adjust the dosing without constructive modifications.

According to a preferred development of the nozzle body comprises a sleeve which surrounds the cavity at least partially, wherein the sleeve comprises at least a portion of the wall portion. In particular, the wall portion may be part of the sleeve. The sleeve can in particular surround and delimit the valve interior or the cavity of the metering device.

Preferably, the sleeve in the region of the wall portion has a smaller wall thickness, as in an adjacent area. This is a lightweight

Ensuring ductility of the wall section so that a technician can assist

Commissioning the metering device, for example, for use for a

Fuel cell, without much effort by light pressure on the

Wall section can adjust the biasing force of the spring device.

Preferably, the sleeve is formed of metal.

Preferably, the sleeve is produced by means of a forming process. The

Dosing device can thus be made very inexpensive, but still allows a precise fine adjustment.

Preferably, the metering device comprises a plastic extrusion which at least partially surrounds the sleeve, wherein the plastic extrusion coating comprises at least a part of the wall section. The plastic extrusion serves as protection of the nozzle body and preferably the magnetic device against external chemical or physical influences. In particular, the plastic extrusion can

Include wall section. Preferably, the wall portion is formed by the plastic extrusion and by the sleeve.

The plastic encapsulation may preferably have a smaller wall thickness in the area of the wall section than in an adjacent area. As a result, the good deformability of the wall section is ensured.

According to a development of the metering device, the wall section comprises a surface structuring, in particular grooves and / or knobs and / or grooves. Through this surface structuring, the force required to deform the

Wall section, which is required for adjusting the biasing force of the spring device can be reduced. The fine adjustment is thus comfortably possible.

Preferably, the wall portion comprises a recess. In particular, the wall portion may be located in a recess of the nozzle body. This can be prevented by an unintentional exercise of force after the end of the

Adjustment process, the biasing force of the spring device is adjusted by mistake. Since the wall section needed to adjust the biasing force is inside the recess, it is protected against accidental deformation.

According to one embodiment of the invention, the nozzle body has a sleeve, which is produced by means of a forming process. The sleeve may have a cylindrical side wall and a sleeve bottom, wherein in the sleeve bottom in the axial direction of a recess is formed. The sleeve is flexible and deformable in the region of the sleeve bottom and consists there for example of plastic or a thin metal layer. To protect the nozzle body, a plastic extrusion can further be formed around it.

For adjusting the biasing force of the sleeve bottom, for example, be pushed further into the interior of the metering device to increase the biasing force of the spring means.

Preferably, the biasing force is adjusted after assembly of the metering device. Brief description of the drawings In the drawings:

Figure 1 is a schematic cross-sectional view of a metering device according to an embodiment of the invention; and

Figure 2 is a schematic cross-sectional view of a detail of the metering device according to an embodiment of the invention for illustrating the deformation of the wall portion.

In all figures, the same or functionally identical elements and devices are provided with the same reference numerals. Various embodiments can be combined as desired, if appropriate.

Description of the embodiments

FIG. 1 illustrates a schematic cross-sectional view of a metering device 1 according to an embodiment of the invention. The metering device 1 is preferably provided for a fuel cell and serves, for example, for metering the supplied amount of fluid, for example hydrogen H2.

The metering device 1 comprises an elongated nozzle body 2, which comprises a sleeve 21. The sleeve 21 is preferably produced inexpensively by means of a forming process. It is elongated and has a side wall 211, which is arranged cylindrical about an axis X around. The sleeve 21 further comprises at one axial end a sleeve bottom 212 which has a recess.

At the opposite axial end, the sleeve 21 is a first

Düsenkörperendstück 27 positively connected, wherein the first nozzle body end piece 27 at one of the sleeve 21 facing away from the axial end with a second

Nozzle body end piece 28 is positively connected.

The sleeve 21, the first nozzle body end piece 27 and the second nozzle body end piece 28 form the nozzle body 2, which encloses a cavity 3. This conclude that first nozzle body end piece 27 and the second nozzle body end piece 28 a first end portion 31 of the cavity 3, while a second end portion 32 of the cavity 3 in the region of the sleeve bottom 212 is formed. A nozzle needle 5 is arranged axially displaceably in the cavity 3. At an axial end of the nozzle needle 5, this is a spring plate 25 with a

Spring device 6 is connected, wherein the spring means 6 along the axis X between a wall portion 10 of the nozzle body 2 in the second end portion 32 and the nozzle needle 5 is arranged.

The spring device 6 is designed as a helical spring and is preferably made of a metallic material. The spring means 6 is adapted to apply a biasing force to the nozzle needle 5 in the direction of the first end portion 31 of the

Exercise cavity 3. A pole piece 22 with a cylindrical outer side is arranged in a form-fitting manner in the sleeve 21 and surrounds the spring means 6. A seal 24 positively connected to the pole piece 22 has an opening in the axial direction and serves to guide the nozzle needle 5. The pole piece 22 and the seal 24 separate the first end portion 31 of the cavity 3 from a middle one

Cavity 33 of the cavity. 3

The nozzle needle 5 comprises a cylindrical anchoring needle 52 and an armature 51, which is also substantially cylindrical and about a central portion of the

Ankernadel 52 is arranged around. The armature 51 is arranged axially movable in the central cavity chamber 33. The anchoring needle 52 extends through a second seal 26 and into the first end region 31 of the cavity 3, wherein the second seal 26 is arranged in a form-fitting manner in the first nozzle body end piece 27.

The second nozzle body end piece 28 has a fluid inlet opening 92, which is designed to introduce a gas, for example hydrogen H2. The

Fluid inlet opening 92 is connected via a fluid opening 4 with the first end portion 31 of the cavity 3. A fluid can emerge from the first end region 31 via a fluid outlet opening 91. In the Fluidöfmung 4 a seal 8 is arranged, which closes the Fluidöfmung 4 when the nozzle needle 5 is moved in the direction of the fluid port 4. The nozzle needle 5 is thus adapted to close the fluid opening 4 during a movement in the direction of the first end region 31, so that no fluid from the

Fluid inlet opening 92 can reach the fluid outlet opening 91.

Around the sleeve 21, a magnetic device 7 is arranged in the radial direction, which comprises a coil and is adapted to generate a magnetic field. When a magnetic field is applied, a force is exerted on the armature 51 of the nozzle needle 5 via the pole shoe 22, so that the nozzle needle 5 is moved counter to the biasing force of the spring device 6 in the direction of the second end region 32. The nozzle needle 5 is moved away from the fluid port 4 and opens the fluid port 4, so that a fluid can flow from the gas inlet port 92 to the gas outlet port 91 through the fluid port 4. By applying the magnetic field by means of the magnetic device 7, thus, the inflowing amount of fluid can be controlled.

The magnet device 7 and the axial end region of the sleeve 21 are surrounded by a plastic extrusion coating 23. The plastic extrusion coating 23 comprises a cylindrical portion 231, which is arranged axially around the magnetic device 7, and an axial end portion 232, which extends along the

Sleeve bottom 212 extends. The plastic extrusion 23 is optional.

FIG. 2 illustrates a schematic cross-sectional view of the metering device 1, wherein the wall section 10 of the nozzle body 2 is shown in detail.

As can be seen from FIG. 2, the sleeve bottom 212 has a

annular outer sleeve bottom seal 212c which contacts the

Side wall 211 of the sleeve 212 connects and is formed substantially perpendicular to the axis X. In addition to this in the radial direction outer outer

At the bottom of the sleeve 212c, the sleeve bottom 212 has a circular inner sleeve bottom shoulder 212a, which is also substantially perpendicular to the axis X. Inner sleeve bottom seal 212a is connected to outer sleeve bottom seal 212c via a tapered central sleeve bottom seal 212b. The sleeve bottom 212 has a depression, ie the inner sleeve bottom portion 212a is offset relative to the outer sleeve bottom portion 212c along the axis X in the direction of the cavity 3. The sleeve base 212 is preferably made of a metallic material, wherein the inner sleeve bottom portion 212a preferably has a wall thickness d1 which is smaller than the wall thickness d2 of the outer sleeve bottom portion 212c.

By exerting a force externally in the radial direction along the axis X on the inner sleeve bottom portion 212a, such as a technician's finger or tool, the inner sleeve bottom portion 212a may move from a dashed initial position a distance d toward the second end portion 32 of FIG Cavity 3 are moved. The position of the inner sleeve bottom portion 212a is thereby preferably permanently changed.

By applying the pressure, the spring device 6 is also displaced in the direction of the second end region 32. As a result, the force exerted on the nozzle needle 5 biasing force is increased. Thus, it is possible after commissioning the

Dosing device 1 to make a fine adjustment of the biasing force of the spring means 6 and thereby the counterforce, which must generate the magnetic device 7 to the nozzle needle 5 to open the fluid port 4 in the direction of the second

End section 32 to move.

In the embodiment shown in Figure 2, the deformable wall portion 10 of the nozzle body 2 through the middle sleeve bottom portion 212 b and the inner

Sleeve bottom portion 212a formed. Preferably, the sleeve 21 shown in Figure 2 may be additionally surrounded by a plastic extrusion coating 23, as illustrated in Figure 1. In this case, the deformable wall section 10 is additionally formed by the plastic encapsulation 23 surrounding the middle sleeve bottom section 212b and the inner sleeve bottom section 212a.

In this case, a wall thickness of the plastic extrusion coating 23 in the region of the wall section 10 is preferably smaller than in an adjacent region, ie in the region of the outer sleeve bottom section 212c. According to further embodiments, surface structuring may be formed in the region of the wall section 10 in the sleeve 21 and / or in the plastic extrusion coating 23. Thus, grooves or grooves, be formed to the for

Deformation of the wall portion 10 required force to reduce. For example, the grooves or grooves may be arranged in a circle about the axis X around. Furthermore, nubs or other surface structuring may be provided.

The recess of the sleeve bottom 212 and the plastic extrusion 23 is optional. Thus, only a flat, substantially perpendicular to the axis X trained sleeve bottom may be provided, which is deformable by the action of force in the axial direction.

Claims

claims

A metering device (1), in particular for a fuel cell, having an elongated nozzle body (2) with a cavity (3) which has a first end region (31) and a second end region (32); a fluid port (4) disposed in the first end region (31) for conducting a fluid; a nozzle needle (5), which is arranged axially displaceable in the cavity (3), wherein the nozzle needle (5) when moving in the direction of the first

End portion (31) closes the fluid opening (4) and when moving in the direction of the second end portion (32) opens the fluid port (4); a spring device (6) which is arranged between a wall section (10) of the nozzle body (2) in the second end region (32) and the nozzle needle (5) and a biasing force on the nozzle needle (5) in the direction of the first end region (31) exerts; and a magnetic device (7), which is designed to generate a magnetic field such that the nozzle needle (5) against the biasing force of the

Spring device (6) in the direction of the second end portion (32) is movable; characterized in that the wall portion (10) of the nozzle body (2) in the second end region (32) by a force from the outside in the axial direction is deformable such that the biasing force of the spring means (6) is adjustable.

2. Metering device (1) according to claim 1, wherein the nozzle body (2) has a

Sleeve (21) which surrounds the cavity (3) at least partially, wherein the sleeve (21) comprises at least a portion of the wall portion (10). Dosing device (1) according to claim 2, wherein the sleeve (21) in the region of the wall portion (10) has a smaller wall thickness than in a

adjacent area.

Dosing device (1) according to one of claims 2 or 3, wherein the sleeve (21) is formed of metal.

Dosing device (1) according to one of claims 2 to 4, wherein the sleeve (21) is produced by means of a forming process.

Dosing device (1) according to one of the preceding claims, with a plastic extrusion coating (23) which at least partially surrounds the sleeve, wherein the plastic extrusion coating (23) comprises at least part of the wall section (10).

Dosing device (1) according to claim 6, wherein the plastic extrusion (23) in the region of the wall portion (10) has a smaller wall thickness than in an adjacent region.

Dosing device (1) according to one of the preceding claims, wherein the wall section (10) comprises a surface structuring, in particular grooves and / or nubs and / or grooves.

Dosing device (1) according to one of the preceding claims, wherein the wall portion (10) comprises a recess.

Method for producing a metering device (1), comprising the steps:

Providing an elongated nozzle body (2) having a cavity (3) having a first end portion (31) and a second end portion (32), wherein in the first end portion (31) a fluid port (4) for conducting a fluid is formed;

Providing a nozzle needle (5) which is axially displaceable in the

Cavity (3) is arranged, wherein the nozzle needle (5) when moving in Direction of the first end portion (31) closes the Fluidöffhung (4) and on movement in the direction of the second end portion (32), the Fluidöffhung (4) opens;

Arranging a spring device (6) between a wall section (10) of the nozzle body (2) in the second end region (32) and the nozzle needle (5), the spring device (6) applying a biasing force to the nozzle needle (5) in the direction of the first end region (31) exercises;

Arranging a magnet device (7) which is designed to be

To generate magnetic field such that the nozzle needle (5) against the

Biasing force of the spring means (6) in the direction of the second end portion (32) is movable; and

Deforming the wall portion (10) of the nozzle body (2) in the second end portion (32) by exerting an external force in the axial direction to adjust the biasing force of the spring means (6).