DE102010002109A1 - Sensor arrangement for underpressure plate in automobile engineering, has guiding element and magnet arranged concentrically to each other, where guiding element extends from sensor to ring magnet, which is magnetized in axial direction - Google Patents

Abstract

The arrangement (1) has a flux guiding element (4) and a ring magnet (3) arranged concentrically to each other with respect to center axes (A, B) extending in an axial direction (X). The flux guiding element extends from a magnetic flux-sensitive sensor (2) e.g. hall sensor, in the axial direction to the ring magnet. The magnet is magnetized in the axial direction. The sensor is provided for detection of an axial relative position of the magnet to the sensor. The magnet is axially moved relative to the guiding element. The flux guiding element is arranged at a front surface (2a) of the sensor. An independent claim is also included for a pressure cell comprising a pneumatic actuatable actuator and a sensor arrangement.

Description

The present invention relates to a sensor arrangement according to the preamble of claim 1.

Sensor arrangements of the present type, which can be used in particular for position detection or for distance measurement, z. B. used in pressure boxes or pressure cells, z. B. in automotive technology, where they z. B. for controllable operation of valves, flaps, etc. are used.

In such a pressure cell capture such sensor arrangements z. B. the position of a pneumatically movable in a housing of the pressure cell or operable actuator, for. B. in the form of a plunger, wherein the actuator z. B. is supported on a counter-pressure spring.

A sensor arrangement of the present type, which uses a magnetic signal transmitter, a flux guide and a Hall sensor for position detection is, for. B. from the document DE 203 15 735 U1 known, which relates to a piston-cylinder assembly. Another sensor arrangement, which relates to a magnetic position sensor is, for. B. from the document DE 10 2006 025 429 A1 known. The system described therein comprises two flux guide elements and a field probe arranged between them for detecting the relative position of a radially magnetized ring magnet. However, the known systems are disadvantageous insofar as they require a high cost of materials, condition a significant size or provide complicated arrangements, each accompanied by a high cost.

Proceeding from this, the present invention seeks to propose a sensor arrangement which overcomes the disadvantages of the prior art, allows a small size and can be implemented easily and inexpensively with low material costs.

This object is achieved by the features of claim 1.

According to the invention, a sensor arrangement with a magnetic flux-sensitive transducer, a ring magnet and a flux guide, wherein the flux guide is arranged on an end face of the magnetic flux sensitive and substantially perpendicular to the end face in the axial direction extending therefrom, and wherein the ring magnet relative to the flux guide is axially movable, wherein the annular cross-section of the ring magnet surrounds a central axis extending in the axial direction, wherein the transducer is provided for detecting the axial relative position of the ring magnet to the transducer, and wherein the flux and the ring magnet with respect to their respective axially extending central axes arranged concentrically to each other are, wherein the sensor arrangement has exactly one flux guide which extends from the transducer in the axial direction to the ring magnet, and wherein the ring magnet in the axial direction magne Magne is tisiert.

In an embodiment of the sensor arrangement according to the invention, the flux guide element and the ring magnet and the transducer are arranged concentrically with respect to their respective center axes extending in the axial direction.

In a further embodiment of the sensor arrangement according to the invention, the magnetic flux-sensitive sensor has a Hall element, in particular a neck sensor or a Hall sensor chip.

In yet another embodiment of the sensor arrangement according to the invention, the sensor acts together with an evaluation device for generating a magnetic flux-based output signal.

According to one aspect of the sensor arrangement according to the invention, the evaluation device generates a linearized output signal which corresponds to the axial relative position of transducer and ring magnet.

Furthermore, a sensor arrangement is proposed according to the invention, the ring magnet being movable in the axial direction between a first distal end position remote from the sensor and a second proximal end position adjacent to the sensor, the flux guide element having an extension from the sensor in the direction of the ring magnet, such that the ring magnet is spaced in the first end position in the axial direction of the flux guide.

In one embodiment of the invention, the sensor arrangement, the flux guide is formed rod-shaped.

The invention also proposes a pressure cell with a housing in which a pneumatically actuable actuator is guided, wherein in the housing a sensor arrangement according to the invention is received, wherein the ring magnet of the sensor assembly is movable together with the actuator in the housing in the axial direction relative to the transducer ,

In one embodiment of the pressure cell according to the invention, the pressure cell is designed as a vacuum actuator.

In yet another embodiment of the pressure cell according to the invention, the sensor is arranged in the housing on a housing front side, to which the actuator can move, wherein the flux guide extends in the direction of the actuator.

Further features and advantages of the invention will become apparent from the following description of embodiments of the invention, with reference to the figures of the drawings, which show details essential to the invention, and from the claims. The individual features can be realized individually for themselves or for several in any combination in a variant of the invention.

Preferred embodiments of the invention are explained below with reference to the accompanying drawings.

Show it:

1 an exemplary sensor arrangement according to a possible embodiment of the invention;

2 an example of the sensor arrangement of 1 in a sectional view, wherein the section is guided radially through the flux guide;

3 an example of a pressure cell in section at a first end position of an actuator according to a possible embodiment of the invention; and

4 exemplarily the pressure box of 3 at a displacement position of the actuator.

In the following description and the drawings, the same or comparable functions have the same reference numerals.

1 and 2 show an example of a sensor arrangement according to the invention 1 , which a magnetic flux sensitive transducer 2 , a ring magnet 3 and a flux guide 4 having. The sensor arrangement 1 is intended to the axial relative position of the ring magnet 3 which z. B. with an axially movable, with respect to its travel to be monitored element is connected, with respect to the pickup 2 to detect or detect to detect a position. The sensor arrangement 1 can z. B. be accommodated in a housing, for. B. in a sensor housing or in a housing of a device which requires a travel detection or position detection of an actuator.

The sensor arrangement according to the invention 1 As mentioned, has a ring magnet 3 on, which in the axial direction X relative to the transducer 2 or to which in particular exactly one flux guide 4 the sensor arrangement 1 is movable, in particular from a first, distal end position ( 1 ), in which the ring magnet 3 from the picker 2 is removed, to a second, proximal end position, in which he to the transducer 2 is adjacent. The first and second end positions limit the extent of the measurement path of the sensor arrangement 1 , synonymous with the travel of the ring magnet 3 , The end positions are z. B. by engagement elements z. B. in the form of a sensor housing or a stop element, etc. defined. The first and second end positions are related to the transducer 2 especially on exactly one side of the pickup 2 defined in the axial direction X, in particular on that side on which the flux guide 4 from the pickup 2 extends away.

The ring magnet 3 is in particular an axially magnetized magnet, for. B. a permanent magnet whose magnetic poles north (N) and south (S) in the axial direction X adjacent to each other, wherein in 1 the north pole (N) to the transducer 2 points, while the south pole (S) facing away from it. A reverse arrangement is possible.

The ring magnet 3 extends in the sensor arrangement 1 in particular z. B. cylindrical or hollow cylindrical in the axial direction X, wherein the annular cross-section 3b or the annular end face 3b the transducer 2 facing, z. B. parallel to its end face 2a is aligned. In other words, the runs of the ring cross-section 3b or the cylinder embraced center axis B of the ring magnet 3 in the axial direction X. The term ring form or ring magnet in the present case also denotes a deviation from the circular shape, in particular also from the closed ring shape. The ring magnet 3 can in a traversing movement in connection with a position detection z. B. the flux guide 4 embrace, ie the inside 3a is in this case radially adjacent to the outside 4a of the flux guide 4 , The ring magnet 3 is in the sensor array 1 In particular concentric with the flux guide 4 arranged or aligned, ie the axial axes X extending center axes A and B of the same fall together ( 1 . 2 ) or are coaxial with each other.

The river management element 4 is z. B. a rod-shaped element, for. B. a round rod-shaped or substantially cuboidal element, with other shapes and associated Cross sections are also conceivable. The flux guide 4 is formed for example of ferromagnetic material, for. B. from a sheet or wire. The flux guide 4 serves in a known manner to focus the field lines of the magnetic field, which of the ring magnet 3 out. Such a bundling results in high field strengths in the flux guide 4 , which of the at the flux guide 4 arranged transducers 2 can be detected. The flux guide 4 has z. B. dimensions, the immersion in the ring cross-section of the ring magnet 3 allow, where it is its greatest length z. B. in the axial direction X has.

It is inventively provided that the flux guide 4 in the axial direction X up to the ring magnet 3 extends in the first, distal end position, z. B. to the inner cavity. Furthermore, the invention also provides the flux guide 4 shorter or shorter form, which can be realized in addition to a material and a cost savings. The flux guide 4 is in particular designed such that the ring magnet 3 in the first, distal end position, towards which or in the direction of which the flux guiding element 4 extends, from the flux guide 4 is spaced in the axial direction X. One end each 3b respectively. 4b of the flux guide 4 and the ring magnet 3 lie in the first end position of the ring magnet 3 consequently in the axial direction X opposite. In this arrangement, the measuring path is also on the flux guide 4 used in the direction of the first end position, without a detection of the position is canceled. This can be z. B. be realized by means of an appropriately trained evaluation or evaluation, with such z. B. can also linearize the resulting nonlinearities in the waveform.

The flux guide 4 is at the magnetic flux sensitive transducer 2 , in particular on one side, arranged such that it extends away from it substantially perpendicularly in the axial direction X, ie towards the ring magnet 3 , Here is the flux guide 4 According to the invention, in particular on an end face 2a which z. B. is formed magnetic flux sensitive, the pickup 2 arranged. The flux guide 4 is z. B. with one of the first end face 4b in the axial direction opposite end face 4c at the pickup 2 An arrangement with an air gap is also conceivable. During a movement of the ring magnet 3 from the first end position, which z. In 3 is shown, towards the second end position or vice versa, which changes from the pickup 2 detectable or detected magnetic flux along the axial travel or measurement path.

The pickup 2 In the present case, a magnetic flux-sensitive or magnetic flux-sensitive transducer, for. B. a field probe, z. B. in the form of a Hall element, a Hall sensor or a Hall sensor chips, which z. B. may have an integrated evaluation or an integrated evaluation. To achieve the smallest possible sensor arrangement is z. B. provided, the transducer 2 with his face 2a at the flux guide 4 to arrange such that both the ring magnet 3 , the flux guide 4 as well as the pickup 2 are arranged concentrically with respect to their axially extending central axes B and A and C, ie, their central axes A, B, C are coaxial with each other.

It is inventively provided, the transducer 2 in such a way that its magnetic flux sensitive front side 2a at the front 4c of the flux guide 4 can be arranged. According to the invention, for. B. a pickup 2 be used in the form of a transversal sensor, z. B. a Hall element or a Hall sensor, wherein a B-field perpendicular to the end face 2a of the pickup 2 or whose housing is measured. The pickup 2 can z. B. have a cuboid or platelet shape.

The pickup 2 may be operatively connected to an evaluation unit based on that of the transducer 2 detected, from the flux guide 4 bundled magnetic flux, generates an output signal for position evaluation, in particular a linearized output signal, which with the detected magnetic flux, starting from the ring magnet 3 corresponds. The evaluation unit is z. B. equipped with a microprocessor and / or z. B. be part of a control or regulation.

According to the invention, the sensor arrangement is provided 1 z. B. for travel detection or position detection of a movable element z. B. in the form of an actuator, wherein the ring magnet 3 together with the actuator relative to the transducer 2 is axially movable, for. B. towards or away from this. Such an arrangement is present z. B. in a vacuum plate or a pressure box ( 3 . 4 ) used.

An inventive pressure cell or pressure cell 5 has a housing 6 on, which for receiving a sensor arrangement according to the invention 1 as well as B. for receiving and guiding an actuator 7 is provided. In the case 6 is still z. B. a counter-pressure element 8th , z. B. in the form of a spring 9 , z. B. a coil spring arranged. The housing 6 is through the actuator 7 which z. B. a membrane 10 has, in two gas-tight separated, axially adjacent chambers 11a . 11b ( 4 ) divisible.

To an axial positioning or movement of the actuator 7 to cause this can be operated pneumatically, z. B. by setting different pressure levels in at least one chamber 11a . 11b of the housing 6 , The housing 6 points to z. B. a vacuum connection 12 on, by means of which a chamber pressure level is adjustable in particular by negative pressure, present z. B. that of the chamber 11b , As a result of a negative pressure on the chamber 11b can that be in the case 6 guided actuator 7 in the axial direction (in 3 and 4 from right to left) move pneumatically.

According to the invention, the sensor arrangement is provided 1 such in the housing 6 to arrange that the ring magnet 3 together with the actuator 7 moves in the axial direction X leaves, z. B. as a result of actuation of the actuator 7 , wherein it is provided that the ring magnet 3 the transducer 2 facing, in particular with its ring cross-section 3b , and relative to this, z. B. towards and away from this, can move. Such an arrangement show 3 and 4 , wherein the ring magnet 3 on the actuator 7 is arranged for common movement with the same, for. B. by a force, material or positive fastening method. The axially extending center axes of the actuator 7 and the ring magnet 3 are z. B. coaxial.

The actuator 7 is z. B. in the form of a plunger, a rod, etc., which z. B. through a housing opening 13 the sensor arrangement 1 remote chamber 11a , extending, with the opening 13 z. B. is an end opening, which in another, the transducer 2 opposite housing front side 6b is formed and an axial movement of the actuator 7 at z. B. simultaneous guidance allows. By means of the actuator 7 can an actuation of another element, for. As a rotary valve, a valve shaft, a valve, etc. done in a planned and known manner. On the actuator 7 is arranged z. B. also the membrane 10 showing the gas tightness between both chambers 11a . 11b while z. B. an actuating or traversing movement of the actuator 7 guaranteed in a known manner, for. B. an elastomeric, Rollbalgartig formed membrane 10 ,

Upon actuation of the actuator 7 can the ring magnet 3 from his in 3 shown first, distal end position towards the transducer 2 the sensor arrangement 1 which is in the housing 6 the actuator 7 is arranged axially opposite, z. B. on a housing front 6a , move, with the flux guide 4 z. B. in the inner cavity of the ring magnet 3 can dive. In the absence of pneumatic (sub) pressurization or actuation, the actuator can 7 from the picker 2 in the axial direction remove X (in 3 . 4 from left to right), z. B. due to a back pressure, which z. B. from the counter-pressure element 8th in z. B. shape of the coil spring 9 is exercised. The feather 9 can be z. B. on the housing 6 , z. B. on the sensor-side housing end face 6a , and opposite to the actuator 7 supported or caught between them.

The pickup 2 which is in the housing 6 can be plugged, clipped or otherwise inexpensively integrated, is provided in the present case, by the actuator 7 or the ring magnet 3 to detect or detect axially traveled distance as a result of a pneumatic actuation. This is done by the transducer 2 with the magnetized in the axial direction and the actuator 7 arranged ring magnets 3 together, being at the pickup 2 the flux guide 4 as part of the sensor arrangement 1 arranged as described above.

The end positions of a movement of the ring magnet 3 or the actuator 7 be z. B. through the housing 6 and / or z. B. the counter-pressure element 8th defined, in the sense that the housing 6 limits the travel, z. B. by its cross-section or stop elements or the counter-pressure element 8th by a counter-pressure force due z. B. a spring compression.

It is inventively provided that the flux guide 4 from the ring magnet 3 can be spaced in the axial direction as soon as the ring magnet 3 the distal, first end position in the housing 6 has taken. This is illustrated by the distance a in 3 ,

The proposed sensor arrangement 1 is extremely tolerant of tilting and blurring of the ring magnet 3 , Since such movements automatically through the as described construction of a pressure box 5 is to strive, that the sensor assembly 1 not sensitive to what is achieved in the present case.

LIST OF REFERENCE NUMBERS

1

sensor arrangement

2

Magnetic flow-sensitive transducer

2a

End face transducer

3

ring magnet

3a

Inside ring magnet

3b

ring-shaped front ring magnet

4

flux collector

4a

Outside flux guide

4b, c

End faces flux guide

5

Vacuum unit

6

casing

6a, b

Front side housing

7

actuator

8th

Counterpressure element

9

feather

10

membrane

11a, b

chambers

12

pressure connection

13

opening

N, S

magnetic poles

X

axial direction

a

distance

A, B, C

central axes

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 20315735 U1 [0004]
• DE 102006025429 A1 [0004]

Claims (10)

Sensor arrangement ( 1 ) with a magnetic flux sensitive transducer ( 2 ), a ring magnet ( 3 ) and a flux guide ( 4 ), wherein the flux guide ( 4 ) on an end face ( 2a ) of the magnetic flux sensitive transducer ( 2 ) is arranged and substantially perpendicular to the end face ( 2a ) extends in the axial direction (X) thereof, and wherein the ring magnet ( 3 ) relative to the flux guiding element ( 4 ) is axially movable, wherein the annular cross-section ( 3b ) of the ring magnet ( 3 ) extends in the axial direction extending central axis (B), wherein the transducer ( 2 ) for detecting the axial relative position of the ring magnet ( 3 ) to the transducer ( 2 ) is provided, and wherein the flux guide ( 4 ) and the ring magnet ( 3 ) are arranged concentrically with respect to their respective central axes (A, B) in the axial direction (X), characterized in that the sensor arrangement ( 1 ) exactly one flux guide ( 4 ), which extends from the transducer ( 2 ) in the axial direction (X) towards the ring magnet ( 3 ), and wherein the ring magnet ( 3 ) is magnetized in the axial direction. Sensor arrangement ( 1 ) according to claim 1, characterized in that the flux guide ( 4 ), the ring magnet ( 3 ) and the transducer ( 2 ) are arranged concentrically with respect to their respective, in the axial direction extending central axes (A, B, C) to each other. Sensor arrangement ( 1 ) according to one of the preceding claims, characterized in that the magnetic flux sensitive transducer ( 2 ) has a Hall element, in particular a Hall sensor or a Hall sensor chip. Sensor arrangement ( 1 ) according to one of the preceding claims, characterized in that the transducer ( 2 ) cooperates with an evaluation device for generating a magnetic flux-based output signal. Sensor arrangement ( 1 ) according to claim 4, characterized in that the evaluation device generates a linearized output signal, which with the axial relative position of transducer ( 2 ) and ring magnet ( 3 ) corresponds. Sensor arrangement ( 1 ) according to one of the preceding claims, characterized in that the ring magnet ( 3 ) between a first distal, from the transducer ( 2 ) distal end position and a second proximal, to the transducer ( 2 ) adjacent end position in the axial direction (X) is movable, wherein the flux guide ( 4 ) an extension of the transducer ( 2 ) in the direction of the ring magnet ( 3 ), such that the ring magnet ( 3 ) in the first end position in the axial direction (X) of the flux guide ( 4 ) is spaced. Sensor arrangement ( 1 ) according to one of the preceding claims, characterized in that the flux guide element ( 4 ) is formed rod-shaped. Pressure cell ( 5 ) with a housing ( 6 ), in which a pneumatically actuable actuator ( 7 ), characterized in that in the housing ( 6 ) a sensor arrangement ( 1 ) according to one of the preceding claims, wherein the ring magnet ( 3 ) of the sensor arrangement ( 1 ) together with the actuator ( 7 ) in the housing ( 6 ) in the axial direction (X) relative to the transducer ( 2 ) is movable. Pressure cell ( 5 ) according to claim 8, characterized in that the pressure box ( 5 ) is designed as a vacuum plate. Pressure cell ( 5 ) according to one of claims 8 and 9, characterized in that the transducer ( 2 ) in the housing ( 6 ) on a housing front side ( 6a ) is arranged, to which the actuator ( 7 ), wherein the flux guiding element ( 4 ) towards the actuator ( 7 ).

Images