CN2349583Y

CN2349583Y - Magnetic assembly for shock-sensor

Info

Publication number: CN2349583Y
Application number: CN 98232597
Authority: CN
Inventors: 孙碧华; 冯哲
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-31
Filing date: 1998-03-31
Publication date: 1999-11-17
Anticipated expiration: 2008-03-31

Abstract

The utility model relates to a magnetic assembly for a shock sensor. The magnetic body of the magnetic assembly is embedded in a compensation ring; the junction face end of a yoke and the magnetic body is provided with a cylindrical type lug boss, and the cylindrical type lug boss is embedded in the compensation ring. The utility model utilizes the performance of the magnetic body maximumly to generate a uniform working air gap field with high intensity, and the utility model has the advantages of reasonable structure and assembly, simple production process and low cost.

Description

The magnet assembly of shock sensor

The utility model relates to a kind of magnet assembly of shock sensor, relates in particular to a kind of magnet assembly of seismic sensor.

Little harmonic distortion is the important technology index that current seismic sensor is pursued.Harmonic distortion is can produce a kind of nonlinear distortion that harmonic wave is a feature with an incoming frequency.The factor that influences transducer distortion mainly contains two: one is the harmonic distortion that spring leaf causes, one is the harmonic distortion that non-homogeneous work magnetic field causes.For reducing the harmonic distortion of sensor, the design of spring leaf has reached its maturity at present, but the uniform magnetic field problem is not resolved always.The ring-like space that forms between sensor yoke and the shell forms the work magnetic field of sensor.To this sensor owing to be subjected to the sensor whole height, especially the very low restriction of magnet coercive force, can not make the yoke height greater than coil height by increasing the yoke height, reducing the magnet height and widen uniform magnetic field, reach the purpose that reduces sensor harmonic distortion.If so, the magnetic field that magnet produces with deficiency so that normal operation of sensor.The magnet assembly of existing inductosyn, generally all be on round permanent magnet two pole-faces, respectively to put a dish-type yoke, be used for reducing the magnetic resistance of air gap, the leakage flux of magnet, the susceptibility that magnet influences demagnetization, for the requirement that guarantees to obtain evenly and strong air-gap field and guarantee machinery assembling rationally, all adopt the version of dish-type yoke diameter dimension greater than the permanent magnet diameter dimension.At present, the aluminium-nickel-cobalt magnetic body sensor of domestic and international output maximum, because coercive force and magnetic energy product are all very low, thereby the magnet volume root is big; Because this material closes a large amount of rare metal cobalts, make the magnet price very high, and it is almost unworkable to reduce cost in addition.Chinese patent ZL93228334.2 discloses " a kind of seismoreceiver ", its use be the rare-earth magnet of high-temperature coefficient, the neodymium iron boron magnetic body of terres rares specifically.The compensation sheath ring that this sensor has used pyromagnetic compensator alloy with temperature compensation characteristic to make.Sheath is located in the middle of the magnet, or integrally is placed in the magnet outside.The sort of structure no matter, magnet or magnet all will embed the dish-type yoke with the sheath ring.This combination of magnet, sheath ring, yoke has limited the performance of magnet performance.Rare-earth magnet coercive force and magnetic energy product are all very high, consider that from the angle of saving material, performance magnetic property this combination also is difficult to accomplish the optimal design of magnet.Use the wave detector of this technology development at present, only can take out 23% of its maximum magnetic energy product.Adopt this combination, when two yoke spacings near or during smaller or equal to the spacing of working sensor magnetic field yoke and shell, the leakage field between two yokes will obviously increase, this is very to be harmful to sensor.To eddy current sensor, influence especially obvious.Because have coil and eddy current becket between eddy current sensor work magnetic field, its gap, work magnetic field will be obviously greater than the electrodynamic type sensor that has only coil between work magnetic field.When magnet embeds yoke with compensation sheath ring, because sheath ring magnetoconductivity is low, and is subject to influence of temperature change, thereby will influence the homogeneity in working sensor magnetic field, make the harmonic distortion characteristic of sensor become big or unstable.The Chinese patent " high resolution earth-quake detector " of Canada Shore industrial group application, number of patent application: 95195123.8; What this sensor used is the higher rare-earth magnet of temperature coefficient, the samarium-cobalt magnet of terres rares specifically.Its temperature stability is relatively poor.Though this wave detector magnet volume is little, the combination of magnet and yoke still can not be given full play to the optimum performance of magnet, and the magnet cost is very high.Because it still adopts magnet to embed the version of dish-type yoke.So, when the axial minimum dimension of two yokes near or during smaller or equal to the spacing of working sensor magnetic field yoke and shell, still have the bigger shortcoming of leakage field between two yokes.For avoiding this leakage field phenomenon, general employing increases the mode of magnet length, and it will cause the waste of magnet material; Reduce the mode that magnet embeds the yoke part if adopt, then can not make full use of the magnetic property of magnet, also will cause the waste of magnet.

The purpose of this utility model is to avoid above-mentioned weak point of the prior art, and provide a kind of structure, assembling rationally, and maximally utilise magnet performance, can produce the intensity height and uniform working gas gap magnetic field, production technology is simple, the magnet assembly of the shock sensor that cost is low.

Design proposal of the present utility model is as follows:

A kind of magnet assembly of shock sensor, comprise yoke (1), magnet (2) and annular compensated loop (3), its special character is: the magnet of described magnet assembly (2) is embedded in the compensated loop (3), described yoke (1) is provided with cylindrical boss (4) with the faying face end of magnet (2), and this cylindrical boss (4) is embedded in the compensated loop (3).

Magnet of the present utility model (2) is advisable to adopt neodymium iron boron magnetic body.

The external diameter of the external diameter of the utility model compensated loop (3) and yoke (1) can be identical.

The outside surface of the utility model compensated loop (3) can be protruding in yoke (1) outside surface, constitutes boss (5).

The outside surface of the utility model compensated loop (3) can be recessed in yoke (1) outside surface, constitutes groove (6).

The accompanying drawing drawing is described as follows:

Fig. 1～3 are respectively the structural representation of three embodiment of the utility model.

The utility model is described in further detail below in conjunction with accompanying drawing:

Referring to Fig. 1, magnet 2 of the present utility model embeds in the pyromagnetic compensated loop 3, and the axial dimension of compensated loop 3 is greater than magnet 2 axial dimensions.Magnet 2 can adopt rare-earth magnet, is advisable to adopt neodymium iron boron magnetic body, and the length-diameter ratio of magnet 2 is advisable with≤0.9, is the best with 0.23.Yoke 1 is provided with cylindrical boss 4 with the faying face end of magnet 2, and this boss 4 embeds in the compensated loop 3.The size axial length that embeds the yoke boss 4 in the compensated loop 3 is advisable with 〉=0.1.mm, that is to say that compensated loop 3 axial dimensions are than magnet 2 axial dimensions 〉=0.2mm.The axial dimension of yoke 1 maximum gauge circle and magnet 2 axial dimensions are than being advisable with 〉=0.20.The external diameter of compensated loop 3 can be identical with the maximum outside diameter of yoke 1.Referring to Fig. 2, the external diameter of compensated loop 3 also can be greater than the maximum outside diameter of yoke 1, and promptly compensated loop 3 outside surfaces have protruding boss 5 in yoke 1 outside surface.Referring to Fig. 3, the external diameter of compensated loop 3 also can be less than the maximum outside diameter of yoke 1, and promptly compensated loop 3 is depressed in the outside surface of yoke 1, forms groove 6.Available in use one group of magnetic assembly of the present utility model also can adopt two groups or many groups.Magnet 2 and yoke 1 can be solid construction according to needs, also can be hollow-core construction.

The utility model compared with prior art has following advantage:

1, the utility model magnet and pyromagnetic compensation structure of rings have axially and radially pyromagnetic compensated loop concurrently and limit The position effect. Thereby make the yoke structure break first the old model of disc-shape, and make the direct and yoke of magnet two pole-faces Iron circle flat pole face combines.

2, to have a process for machining simple for the yoke of Step Circular shape, and surface accuracy, positional precision realize easily Advantage, thereby reduced magnet two pole-faces and yoke pole-face seam and and pyromagnetic compensated loop between the assembling air gap, Make the more closely combination of each parts, reduced the magnetic pressure of working gas gap and fallen.

3. it is spacing much smaller than the pyromagnetic compensated loop of yoke that the magnet two ends have utilized permeability, and the magnetic line of force is by magnet two End is more by the very big yoke of permeability, and reduced the non-working-gap between pyromagnetic compensated loop and magnet Leakage field has increased the magnetic line of force by the more uniform ability by working gas gap in the work side of yoke, maximum limit Utilized magnetic property degree.

4, the utility model maximally utilised the rare earth permanent magnet hysteresis curve have straight line demagnetization and high rectify stupid The characteristic of power reduces the magnet height greatly, and sectional area increases relatively, and the magnetic property of magnet is fully sent out Shoot, can make again the structure of magnetic circuit accomplish optimal design.

5, adopt the neodymium iron boron magnet, its remanent magnetism reversible temperature coefficient is less than samarium-cobalt magnet, magnetic energy product then greater than Samarium-cobalt magnet. The control of the uniformity of magnet magnetic property is much better than samarium-cobalt magnet, its will make wave detector production efficiency, Yield rate, production cost obviously are better than samarium-cobalt magnet. The price of neodymium iron boron magnet is lower than samarium-cobalt magnet more than 40%, Its mechanical performance also obviously is better than samarium-cobalt magnet.

6, uniform high-intensity magnetic field in the working gas gap strengthens its ability that suppresses stray magnetic field, has improved work The magnetic induction intensity of air gap is conducive to reduce the distortion factor of sensor, in other parts frame for movement of sensor In the constant situation, magnetic structure of the present utility model and ZL93228234.2 " a kind of geophone " are special Profit is compared, and sensing sensitivity can improve more than 10%.

7, the utility model is applied in the sensor, the design of its work magnetic field clearance height and coil height can be designed to work magnetic field clearance height by the requirement of sensor performance index more than or equal to coil height, also can be designed to work magnetic field clearance height less than coil height.Improved oscillatory type Design of Sensor degree of freedom thus.That is, make its inner structure size, the scope that ratio is regulated increases, and simultaneously, can adopt the less magnet of volume, and cost is reduced greatly.

8, the utility model is widely applicable, can be used for seismic prospecting and measurement.Adopt inductosyn of the present utility model, as measuring absolute vibration, vibration monitoring and vibrations research, can be used for aircraft engine, various large-size machine, air compressor, lathe, vehicle, sleeper bumper, chemical plant, various waterpipe, feed channel, bridge, building etc.

Claims

1, a kind of magnet assembly of shock sensor, comprise yoke (1), magnet (2) and annular compensated loop (3), it is characterized in that: the magnet of described magnet assembly (2) is embedded in the compensated loop (3), described yoke (1) is provided with cylindrical boss (4) with the faying face end of magnet (2), and this cylindrical boss (4) is embedded in the compensated loop (3).

2, the magnet assembly of shock sensor as claimed in claim 1 is characterized in that: described magnet (2) is a neodymium iron boron magnetic body.

3, the magnet assembly of shock sensor as claimed in claim 1 or 2 is characterized in that: the external diameter of described compensated loop (3) is identical with the external diameter of yoke (1).

4, the magnet assembly of shock sensor as claimed in claim 1 or 2 is characterized in that: the outside surface of described compensated loop (3) is protruding in yoke (1) outside surface, constitutes boss (5).

5, the magnet assembly of shock sensor as claimed in claim 1 or 2 is characterized in that: the outside surface of described compensated loop (3) is recessed in yoke (1) outside surface, constitutes groove (6).