WO2010040586A1

WO2010040586A1 - Magnetic coil, motor vehicle component having a magnetic coil, and use

Info

Publication number: WO2010040586A1
Application number: PCT/EP2009/060467
Authority: WO
Inventors: Klaus-Volker Schuett; Thomas Grossschatz; Cornelius Gaida; Stephan Geise; Bertram Sugg
Original assignee: Robert Bosch Gmbh
Priority date: 2008-10-08
Filing date: 2009-08-13
Publication date: 2010-04-15
Also published as: DE102008042686A1

Abstract

The invention relates to a magnetic coil (18) wound from a coil wire (22), particularly for a motor vehicle component. According to the invention, the cross-sectional area of the coil wire (22) has a square contour.

Description

description

title

Magnetic coil, motor vehicle component with magnetic coil and use

State of the art

The invention relates to a wound from a coil wire te solenoid, in particular for a motor vehicle component, such as a fuel injector, a solenoid valve or a sensor according to the preamble of claim 1, a motor vehicle component with a magnetic coil according to claim 8 and a use according to claim 10.

From DE 10 2006 058 073 Al a solenoid valve for a fuel injection system is known. This comprises an electromagnetic actuator with a wound from a coil wire magnetic coil. The coil wire has a circular contoured cross-sectional area and is provided with a, usually applied in the wet-coating process, insulation. The copper fill factor (winding density) of known magnetic coils for the automotive sector is about 63%, which adversely affects the space requirement and the maximum achievable power density.

From the Japanese entertainment industry insulated coil wires (winding wires) are known with rectangular cross-section. These have a width / thickness ratio of typically two to five and are provided with insulating wall thicknesses of below 10 microns having insulating layers, wherein the insulating layers are typically applied by electrostatic methods. DISCLOSURE OF THE INVENTION Technical Problem

The invention has for its object to provide an optimized in terms of space requirements magnet coil, in particular for a motor vehicle component. Preferably, large power densities should be realizable with the magnetic coil. Furthermore, the object is to provide a motor vehicle component, such as a fuel injector, a solenoid valve or a sensor with a correspondingly optimized magnetic coil.

Technical solution

This object is achieved in terms of the magnetic coil having the features of claim 1 and by a use according to claim 10. With regard to the motor vehicle component, the object is achieved with the features of claim 8. Advantageous developments of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention.

The invention has recognized that large coil wire fill factors (winding densities), in particular copper fill factors, can not be realized with circularly contoured coil wires. Furthermore, the invention has recognized that even rectangularly contoured coil wires do not lead to optimum coil wire filling factors, since at least in areas of the winding layer transitions unfilled areas result, which increase with increasing wire width due to the then forced Incidentally increasing winding pitch become larger. The invention is based on the idea to use coil wires (winding wires) with a square cross section for producing a magnet coil, in particular for the motor vehicle sector, thereby avoiding unfilled gussets and minimizing unfilled areas in the winding layer junctions. In addition, square coil wires basically have a more favorable volume-surface ratio than rectangular coil wires, and thus, with the same insulation wall thickness, a smaller need for insulation material. This also accommodates the demand for a large coil wire fill factor. A trained according to the concept of the invention solenoid is particularly suitable for modern diesel injection technology with increasing demands on consumption, CO ₂ emission and particulate emission. These requirements are met only highly dynamic fuel injectors with short switching times for the realization of a multipoint injection, with which also high magnetic forces to control the increasing diesel pressures can be realized. Quite essential here is the minimization of the required installation space, which can be realized with a coil wire shaped according to the concept of the invention in a square cross-section. A magnetic coil designed according to the concept of the invention can be realized with an extremely compact electrical winding with a high coil wire fill factor, in particular a copper fill factor, a sufficiently large wire cross section and a low number of turns. Preferably, the edge length of the coil wire is chosen so that it is optimally adapted to the winding window and the windings of this, at least approximately, completely fill. In a further development of the invention is advantageously provided that the coil wire is provided with an insulating layer, which is applied by an electrostatic process. As a result, very uniform insulation layers with layer thicknesses of 10 microns or less can be achieved.

Particularly preferred is an embodiment in which the coil wire is wound on a coil carrier, preferably made of plastic, wherein the coil wire particularly preferably with one, in particular as Finalumspritzung

(Protective layer of plastic) formed, preferably thin-walled, envelope is provided, preferably to the

Coil wire against corrosive media, such as

Fuel, optimal protection. It is particularly preferred if the envelope has a wall thickness of less than 200 μm, preferably of less than 175 μm, very preferably of around 150 μm or less. This can be achieved particularly well by the use of highly flowable thermoplastics (for example modified polyphenylene sulfide trade name Ryton R4 or Xtel XK 2340). Through the use of highly flowable thermoplastics, the necessary process pressure and the necessary process temperature for realizing the final extrusion can be reduced so far that thermal and / or mechanical damage to the coil wire and / or displacement of the coil wires of the uppermost winding are avoided. It is also conceivable to realize the enclosure by casting with reaction resin.

Particularly preferred is an embodiment in which the coil wire fill factor, in particular the copper fill factor, is greater than 70%, preferably greater than 80%, very particularly preferably greater than 90%. Optimum power densities can be achieved with a coil wire having a copper core with a square cross-section within the insulation layer.

The invention also leads to a motor vehicle component having at least one magnetic coil designed according to the concept of the invention. Particularly preferably, the motor vehicle component is a fuel injector or a solenoid valve, in particular a control valve (servo valve) of the fuel injector. This can be realized by providing a designed according to the concept of the invention magnetic coil with a minimum space requirement. In addition, high power densities and thus high magnetic forces can be realized. Furthermore, the motor vehicle component may, for example, be a solenoid valve, for example an ABS and / or driving dynamics valve or a hydraulic valve. Also, the use of a trained according to the concept of the invention solenoid coil in dynamic electromagnetic sensors, especially in the automotive field can be realized.

In addition, the invention leads to the use of a square contoured, in particular a copper core having wire for winding a magnetic coil, in particular for a motor vehicle application. Preferably, the solenoid is integrated into a fuel injector, a solenoid valve or an electromagnetic sensor.

Brief description of the drawings

Further advantages, features and details of the invention will become apparent from the following description Embodiments and with reference to the drawings. These show in:

Fig. 1 in a schematic, fragmentary Dar- position a fuel injector with a a

Solenoid-driven control valve (servo valve), and

2 is a sectional view of a Magnetspulen- winding and an enlarged view of

Cross section of the coil wire of the coil winding.

Embodiments of the invention

In the figures, like elements and elements having the same function are denoted by the same reference numerals.

In Fig. 1 is a detail of a fuel injector 1 (here common rail injector) shown for injecting fuel into a combustion chamber of an internal combustion engine, not shown. The fuel injector 1 comprises an injection valve element 2 which can be adjusted in one or more parts between a closed position and an open position which releases the fuel flow into the combustion chamber. With its upper end in the plane of the drawing, the injection valve element 2 is guided in a sleeve-shaped section 3 of a throttle plate 4 and defines, with its upper side 5, which is in the plane of the drawing, a control chamber 6 formed within the sleeve-shaped section 3. The control chamber 6 is permanently hydraulically connected via an inlet throttle 7 to a pressure chamber 8 of the fuel injector 1 that is substantially under rail pressure. From the control chamber 6 opens an outlet throttle 9, which connects the control chamber 6 with a valve chamber 10 which is bounded radially outwardly by a sleeve-shaped control valve element 11 of a control valve 12 (servo valve). With the aid of the control valve 12, the valve chamber 10 and thus the control chamber 6 is hydraulically connected to a low-pressure region 13 of the fuel injector 1 that is at low pressure and which is connected via a return connection (not shown) to a reservoir (also not shown). The valve chamber 10 is bounded in the axial direction upwards by a pressure pin 14, which protrudes from the top of the drawing in a central bore 15 of the control valve element 11.

For axial adjustment of the control valve element 11, an electromagnetic actuator 16 is provided, which comprises a coil spool 17 arranged on a magnetic coil 18.

When the solenoid coil 18 is energized, an armature plate 19 formed integrally with the control valve element 11 is moved upward in the plane of the drawing in the direction of the electromagnetic actuator 16, whereby the fuel flow from the control chamber 6 is released into the low-pressure region 13 and from there to the return port. The flow cross-sections of the outlet throttle 9 and the inlet throttle 7 are matched to one another such that when the control valve 12 is open, a net outflow of fuel from the control chamber 6 results, with the result of a rapid pressure drop which, in turn, acts on a hydraulic pressure acting in the opening direction of the injection valve element 2 opening ensures force, so that the injection valve element 2 lifts from its injection valve element seat, not shown.

To end the injection process, the energization of the solenoid 18 is interrupted, whereby the control valve member 11 is adjusted by means of a closing spring 20 again on its formed on the throttle plate 4 control valve seat 21. The fuel flowing in via the inlet throttle 7 ensures a pressure increase in the control chamber 6 and thus a closing movement of the injection valve element 2.

As is apparent from Fig. 1, the magnetic coil 18 is formed by a wound coil wire 22 having a square in cross-section circumferential contour. As a result, a high coil wire filling factor can be achieved within a circumferential groove 23 (winding window) formed in the coil carrier 17. It can be seen that the circumferential groove 23 is closed radially on the outside by a ring-shaped final encapsulation 24 (thin-walled cladding) extending in the axial direction in the radial direction. This prevents direct contact of the coil wire 22 with fuel. The wall thickness of the Finalumspritzung 24 in the radial direction is about 150μm in the embodiment shown. With a radial distance to the Finalumspritzung 24 is an inner, the circumferential groove 23 bounding peripheral wall 25 of the bobbin 17 can be seen. The wall thickness of this peripheral wall 25 is also about 150μm.

2, a cross section through a magnetic coil 18 is shown. Evident is the coil winding formed by winding a coil wire 22. 2, it can be seen that the windings of the coil wire 22 fit snugly against each other. the abutment, so that a high Spulendrahtfüllfaktor is achieved. In the embodiment shown, the width B of the magnetic coil 18 is about 2.0 mm and the height H is about 1.2 mm. The cross-sectional contour of a coil wire 22 results from the detailed representation in the drawing plane according to FIG. 2 at the top right. A square-shaped copper core 26 is shown, which is surrounded by a circumferentially closed insulation layer 27. The insulating layer 27 can be applied in an electrostatic process.

The side length 1 of the copper core 26 in the embodiment shown is about 0.187 mm and the side length L of the entire coil wire 22 about 0.20 mm. Thus, the wall thickness of the insulating layer 27 is about 0.013mm.

Claims

claims

1. From a coil wire (22) wound magnetic coil

(18), in particular for a motor vehicle component,

characterized,

the cross-sectional area of the coil wire (22) is square-shaped.

2. Magnetic coil according to claim 1, characterized in that the coil wire (22) is provided with an electrostatically applied insulating layer (27).

3. Magnetic coil according to one of claims 1 or 2, characterized in that the coil wire (22) wound on a coil carrier (17) and provided with a, in particular as Finalum- injection (24) or formed as a reaction resin layer, preferably thin-walled, envelope is.

4. Magnetic coil according to claim 3, characterized in that the wall thickness of the Finalumspritzung (24) is less than 200μm, preferably less than 175μm and / or about 150μm.

5. Magnetic coil according to one of claims 3 or 4, characterized in that the final encapsulation (24) is formed from a highly flowable thermoplastic, in particular modified polyphenylene sulfide (PPS).

6. Magnetic coil according to one of the preceding claims, characterized in that the Spulendrahtfüllfaktor greater than 70%, preferably greater than 80%, most preferably greater than 90%.

7. Magnetic coil according to one of the preceding claims, characterized in that the coil wire (22) has a copper core (26).

8. motor vehicle component having a magnet coil (18) according to one of the preceding claims.

9. Motor vehicle component according to claim 8, characterized in that the motor vehicle component is a fuel injector (1), a solenoid valve, or a dynamic electromagnetic sensor.

10. Use of a square contoured cross-sectional area having coil wire (22) for winding a magnetic coil (18), in particular for a motor vehicle component.