WO2002066997A1 - Device, amperemeter and motor vehicle - Google Patents

Abstract

The invention relates to a device, an amperemeter and to a motor vehicle, whereby the measurement of the electric current intensity is carried out in an electrical conductor (1) through which current flows and which has at least one sensor means (15). Said conductor (1) comprises a first section (10), a second section (20), a third section (30) and a fourth section (40), whereby a first current direction is provided in the first and third sections (10, 30), a second current direction is provided in the second and fourth sections (20, 40), and the first current direction and the second current direction are antiparallely provided. The sensor means (15) is provided between the first, the second, the third and the fourth sections (10, 20, 30, 40).

Description

Device, ammeter and motor vehicle

State of the art

Magnetic field sensors are known which can be used as current sensors, the generation of a magnetic field around a current-carrying conductor being used. Hall or magnetoresistive sensors or also lateral magnetotransistors are known as magnetic field sensors. The basic prerequisite for such methods is precise knowledge of the possible field distribution to be measured, in order to be able to make statements regarding the positioning and the positioning accuracy of the sensor element. The measurement is made significantly more difficult in a magnetically disturbed environment and with very small currents to be detected. In such difficult situations, previous solutions used flux concentrators, for example made of ferritic material and / or magnetic shielding measures. However, such measures are expensive and complex and take up a lot of space.

Advantages of the invention

In contrast, the device according to the invention, the current meter according to the invention and the motor vehicle according to the invention with the features of the independent claims have the advantage that a sensor means senses a larger magnetic field than would be possible on a simple straight conductor at a given current strength.

The measures listed in the subclaims permit advantageous developments and improvements of the device, ammeter and motor vehicle specified in the independent claims.

It is particularly advantageous that the conductor is essentially horseshoe-shaped in a first conductor area and thus forms a first horseshoe shape, that the conductor is essentially horseshoe-shaped in a second conductor area and thus forms a second horseshoe shape, the first section being part of a first Legs of the horseshoe shape and wherein the second portion forms part of a second leg of the first horseshoe shape, the third portion forms part of a first leg of the second horseshoe shape and the fourth portion forms part of a second leg of the second horseshoe shape, the first Legs of the first horseshoe shape and the first leg of the second horseshoe shape are connected by a first connecting piece, and the second leg of the first horseshoe shape and the second leg of the second horseshoe shape are connected by a second connecting piece. As a result, the incoming current-carrying conductor is divided into two parallel conductors and bent by 180 °, so that an increase in the magnetic field at the location of the sensor element is achieved in the order of two compared to the equivalent, non-curved arrangement.

It is also advantageous that the conductor has a first reversing piece, that the conductor has a second reversing piece, and that the conductor has a third reversing piece, the first reversing piece being attached connects the first section, the second reversing section being followed by the second section, the second reversing section following the second section, the second reversing section being followed by the third section, the third reversing section being connected to the third section, the third reversal piece of the fourth section follows, the center points of the first, second, third and fourth sections lying in a common plane perpendicular to the sections essentially forming the corner points of a rectangle and the corner point belonging to the first section forming the rectangle in the rectangle the second section of the corner point diagonally opposite. As a result, a magnetic field overlay can be achieved, which leads to an even larger magnetic field, the magnetic field overlay being of the order of magnitude of four times that of the equivalent, non-curved arrangement. There is no current distribution in the conductor used.

Another advantage is that the conductor cross section is round. As a result, the field distribution of the magnetic field around the current-carrying conductor is only weakly dependent on the frequency of the current.

It is also advantageous that the sensor means is a magnetic field sensor, in particular a Hall sensor, a lateral magneto-transistor and / or a magnetoresistive resistor. This makes it possible in particular for the sensor element or sensor means to have a magnetic field sensitivity in the lateral direction, ie parallel to its surface. drawing

Embodiments of the invention are shown in the drawing and explained in more detail in the following description. Show it

Figure 1 shows a first embodiment of an inventive

Conductor in a perspective view,

Figure 2 shows the first embodiment of the invention

Ladder in front view,

Figure 3 shows a second embodiment of the invention

Ladder in perspective view,

Figure 4 is a cross-sectional view of the conductor to the first and second embodiment and

Figure 5 shows another example of the construction of the invention

Contraption.

Description of the embodiments

In Figure 1, a first embodiment of a conductor 1 according to the invention is shown in perspective. The conductor 1 comprises a first conductor region 100 and a second conductor region 200. The first conductor region 100 and the second conductor region 200 are bent in the shape of a horseshoe or a U-shape. This means that the conductor areas 100, 200 in addition to a first leg and a second leg, which are essentially provided straight, have an approximately semicircular connecting piece which connects the first leg and the second leg for each conductor area 100, 200. The first conductor region 100 has a first section 10 of the conductor in the region of a first leg and a second section 20 of the conductor 1 in the region of its second leg. The second conductor area 200 has a third section 30 in the area of its first leg and in the area a fourth section 40 of the conductor 1 on its second leg. The first leg of the first conductor region 100 and the first leg of the second conductor region 200, that is to say the first section 10 and the third section 30, are connected by means of a first connecting piece 5. In the area of the first connecting piece 5 there is a first connection of the conductor 1, which is provided for the supply and discharge of the current. Likewise, the second leg of the first conductor area 100 and the second leg of the second conductor area 200, thus the second section 20 and the fourth section 40, are connected by means of a second connecting piece 25, again in the area of the second connecting piece 25 a further connection for the Supply or discharge of the current is provided.

In Figure 2, the conductor 1 is shown in side view. It is particularly clear here that the conductor 1 is bent in a horseshoe shape in its first conductor region 100 and in its second conductor region 200. The first and third sections 10, 30 as well as the second and fourth sections 20, 40 and the connecting pieces 5, 25 can again be seen.

FIG. 3 shows a second embodiment of the conductor 1 according to the invention. In contrast to the first embodiment, the second embodiment provides that the conductor 1 has the same current strength over its entire course, ie there is no division of the current as in the first embodiment. In the second embodiment, the first section 10, the second section 20, the third section 30 and the fourth section 40 are again provided, each of which in turn runs essentially parallel to one another. To do this by means of the single To reach continuous conductor 1, the conductor comprises three reversing pieces, which invert the conductor by approximately 180 ° each. A first reversing piece 6 adjoins the first section 10, the first reversing piece 6 being followed by the second section 20, which in turn is provided essentially parallel to the first section 10. The second section 20 is followed by a second reversing piece 7, which in turn reverses the conductor by approximately 180 °. The second reversing piece 7 is followed by the third section 30, which in turn is provided essentially parallel to the first section 10 and the second section 20. Furthermore, the conductor 1 comprises, after the third section 30, a third reversing piece 8, which in turn reverses the conductor by approximately 180 °. The first reversing piece 6 and the third reversing piece 8 cross each other in such a way that no electrically conductive connection is provided between the first reversing piece 6 and the third reversing piece 8. Following the third reversal piece 8, the fourth section 40 of the conductor 1 is provided. The geometry of the conductor 1 is provided in such a way that, if a sectional plane is considered which runs in the region of the sections 10, 20, 30, 40 perpendicular to the course of the sections 10, 20, 30, 40, the center points or the centers of the Sections 10, 20, 30, 40 form a rectangle or a square. It is then according to the above description that the centers or the centers of the first section 10 and the second section 20 are diagonally opposite with respect to the said rectangle or said square. It is also clear from the description that the orientation of the current direction in the first section 10 and in the third section 30 is the same and specifies a first current direction. Furthermore, the current direction in the second section 20 and in the fourth section 40 is the same and specifies a second current direction. It is also clear that the first current direction and the second current direction are provided in anti-parallel. The statements about the current direction also apply to the first embodiment, since the current conductor is divided into the first section 10 and the third section 30 starting from the first connecting piece 5 and the current conductor is divided into the second section 20 and starting from the second connecting piece 25 the fourth section 40, so that the current direction in the first and third sections 10, 30 on the one hand and in the second and fourth sections 20, 40 on the other hand each run in parallel, but are oriented antiparallel to one another.

FIG. 4 shows a sectional illustration of the first embodiment of the conductor 1 in the region of the sections 10, 20, 30, 40. It can again be seen that the first current direction in the first section 10 and in the third section 30 is the same, which is represented by a cross which is attached in the first section 10 and in the third section 30 in FIG. 4 and is intended to represent that the current direction is oriented into the drawing plane in the first section 10 and in the third section 30. Accordingly, in the second section 20 and in the fourth section 40 in FIG. 4 there is a point which is intended to clarify that in the second section 20 and in the fourth section 40 the second current direction is oriented out of the plane of the drawing. The current directions defined for sections 10, 20, 30, 40 generate magnetic fields which are indicated by magnetic field lines which are provided with an arrow. A first magnetic field line 11 runs around the first section 10 in a clockwise direction. A second magnetic field line 21 runs counterclockwise around the second section 20. A third magnetic field line 31 runs around the third section 30 in a clockwise direction. A fourth magnetic field line 41 runs counterclockwise around the fourth section 40. On According to the invention, sensor means 15 is provided between the first, second, third and fourth sections 10, 20, 30, 40. The sensor means 15 is held by a mounting plate 50. Because the sensor means 15 is provided exactly in the center between the sections 10, 20, 30, 40, the sensor means 15 for the first embodiment measures approximately twice the magnetic field than it does with the same sensor means 15 and the same distance from the current conductor 1 in one straight conductor would be the case.

The sectional illustration for the second embodiment is identical to that shown in FIG. 4 except for the fact that the reference symbols for the second section 20 and the fourth section 40 (and then of course also the second and fourth magnetic field lines 21, 41) because of the crossing of the first and third connector 6, 8 must be interchanged. It then follows that the center or the center of the first section 10 in the square or rectangle mentioned in connection with FIG. 3 lies diagonally opposite the center or the center of the second section 20. Basically nothing changes in the constellation of the magnetic fields. The difference is that the magnetic field present at the location of the sensor means in the second embodiment is even about 4 times as large as in the comparable case for a straight conductor because the current in the second embodiment is not divided.

In Figure 5 is another assembly example with respect. the first embodiment of the device according to the invention. In addition to the first mounting plate 50, on which the sensor means 15 is fastened, a second mounting plate 51 is provided which, together with the first mounting plate 50, the sensor means 15 exactly between two of the sections, for example positioned between the first section 10 and the second section 20 and the third section 30 and the fourth section 40. For the positioning of the sensor means 50 in the direction perpendicular thereto, for example, webs 52 which are mounted on the mounting plates 50, 51 and the positioning of the sensor means between the first section 10 and the third section 30 or between the second section 20 and the fourth section 40 guaranteed.

For the second embodiment, only the reference numerals for the second section 20 and the fourth section 40 would have to be exchanged in FIG.

It is particularly advantageous to use the device in an ammeter, such an ammeter according to the invention, in addition to the sensor means (15), which is designed, for example, as a Hall sensor, as a lateral magnetotransistor and / or as a magnetoresistive resistor, an evaluation circuit, for example in the form of an ASIC , includes. Such a current meter according to the invention further comprises the conductor 1 in its special geometry. Furthermore, it is provided to integrate such an ammeter according to the invention into a housing by means of the conductor 1 according to the invention, the sensor means 15 including its assembly aids 50, 51, 52, so that only the control and signal lines for the evaluation circuit on the one hand and the feeds and discharges for the current to be measured in conductor 1 is accessible outside the housing. Such a housing is provided according to the invention in particular in the form of a casting compound. In particular, such a casting compound comprises magnetically active material which serves to shield interference magnetic fields at the seat of the sensor means 15. The use of the device according to the invention or the current sensor according to the invention in a motor vehicle for measuring currents of different sizes, in particular over a very wide range of orders of magnitude, is particularly advantageous since electromagnetic interference fields are particularly intense and disruptive in a motor vehicle or in its environment. When setting up the ammeter, care must be taken that the materials used for mounting the sensor means 15 do not influence the field distribution of the magnetic field generated by the current-carrying conductor 1, or only do so to an insignificant extent.

According to the invention, the cross section of the sections 10, 20, 30, 40 is particularly round, but can also be provided differently, for example oval, square, rectangular or the like.

Claims

Expectations 1. Device for measuring the electrical current in an electrical conductor (1) with at least one sensor means (15), a first section (10) of the conductor (1), a second section (20) of the conductor (1), a third section (30) of the conductor (1) and a fourth section (40) of the conductor (1), a first current direction being provided in the first and third sections (10, 30), a second current direction in the second and fourth sections (20, 40) is provided and the first current direction and the second current direction are provided antiparallel and the sensor means (15) is provided between the first, the second, the third and the fourth section (10, 20, 30, 40). 2. Device according to claim 1, characterized in that the first section (10), the second section (20), the third section (30) and the fourth section (40) in the region of the highest sensitivity of the sensor means (15) essentially run parallel to each other. 3. Device according to claim 1 or 2, characterized in that the conductor (1) in a first conductor area (100) is substantially horseshoe-shaped and thus forms a first horseshoe shape that the conductor in a second conductor area (200) is essentially horseshoe-shaped is provided and thus forms a second horseshoe shape, the first section (10) forms part of a first leg of the first horseshoe shape and wherein the second section (20) forms part of a second leg of the first horseshoe shape, the third section (30) forms part of a first leg of the second horseshoe shape and the fourth section (40 ) forms part of a second leg of the second horseshoe shape, wherein the first leg of the first horseshoe shape and the first leg of the second horseshoe shape are connected by a first connecting piece (5) and wherein the second leg of the first horseshoe shape and the second leg of the second horseshoe shape a second connector (25) are connected. 4. The device according to claim 1 or 2, characterized in that the conductor (1) is a first reversing piece (6) has that the conductor (1) a second reversing piece (7) and that the conductor (1) has a third reversal piece (8), the first reversing piece (6) adjoining the first section (10), the first reversing piece (6) being followed by the second section (20), the second reversing piece (7) adjoining the second section (20), with the second reversing piece (7) being followed by the third section (30), the third reversing piece (8) following the third section (30), the fourth reversing piece (8) being followed by the fourth section (8) 40) follows, the center points of the first, second, third and fourth sections (10, 20, 30, 40) lying in a common plane perpendicular to the sections (10, 20, 30, 40) essentially forming the corner points of a rectangle and wherein in the rectangle the corner point belonging to the first section (10) is diagonally opposite the corner point belonging to the second section (20). 5. Device according to one of the preceding claims, characterized in that the conductor cross section is provided round. 6. Device according to one of the preceding claims, characterized in that the sensor means (15) is a magnetic field sensor, in particular a Hall sensor, a lateral magneto-transistor and / or a magnetoresistive resistor. 7. ammeter with a device according to any one of the preceding claims. 8. Motor vehicle with a device or an ammeter according to one of the preceding claims.