CN1834587A - Absolute multi-coil magnetic encoder - Google Patents

Abstract

The invention relates to an absolutely multi-turn magnetism coder. The metal coding disc is distortion round disk shape. And four arcs are set on the radial direction, two opposite side of the same radius has tow arcs, and the third arc is between the next one side, and the fourth arc is set on another side. The coder is simple structure, few components, long useful life, high reliability, etc.

Description

The absolute type multi-coil magnetic encoder

Technical field

The present invention relates to magnetic coder.

Background technology

Scrambler is the displacement transducer that physical quantitys such as spin angular position, angular displacement and angular velocity is converted to electric signal.Along with the development of factory automation, direct current generator is controlled to numerically controlled transformation to the change and the simulation of alternating current generator, and scrambler has shown its superiority, its demand surge.According to the difference of metering system, scrambler is divided into two kinds of increment type and absolute types.Absolute type encoder has, and to detect absolute position, antijamming capability accumulated error strong, that caused by noise at any time be that its application demand of advantage such as zero is increasing year by year.Especially absolute type encoder, measurement range is wide, has both made the rotation that power failure also can the accurate recording measured axis, is widely used in occasions such as for example aperture (displacement) measurement, level gauging.Present absolute type encoder mostly is photoelectric encoder, to wet gas and pollution sensibility, mounting process is had strict requirement, in some applications poor reliability, needs a kind of novel scrambler.In order to adapt to the requirements at the higher level of industry to scrambler, people have developed magnetic coder.For example Chinese patent publication number CN1271416A has announced a kind of absolute type individual pen magnetic coder.Yet in the absolute type magnetic coder technology that formerly has, the data recording in the time of can not solving the axle rotation above a circle, and also the scrambler that CN1271416A announces uses linear transducer, debug difficulties during batch process.

Summary of the invention

The objective of the invention is: provide a kind of and be suitable for rugged surroundings, multi-turn data recording, install simple, reliability is high, cost is low, produce the simple absolute type multi-coil magnetic encoder of debugging.

Concrete structural design scheme is as follows:

The absolute type multi-coil magnetic encoder comprises shell, main shaft, metal code disk, magneto sensor and data processing unit, and metal code disk is fixedly installed on the main shaft, and the magneto sensor correspondence is located on the printed circuit board (PCB) of the axial side of metal code disk, it is characterized in that:

Described metal code disk is discoid for distortion, it directly upwards is provided with four circular arcs, wherein circular arc 14 and circular arc 16 are located at the relative both sides of same radius, and arc length equates, between circular arc 14 and the circular arc 16 adjacent sides is interior concave arc 15, be provided with interior concane gap between the opposite side, interior concane gap is provided with interior concave ring groove along circular arc 16 1 sides, and interior concane gap circular arc limit and the interior trough rim of the annular groove that links to each other are circular arc 17.

Useful technique effect of the present invention is:

1, by on code-disc, engraving groove by certain coded system, detect the position that the coding of code-disc in a certain position obtains code-disc by magneto sensor, the cumulative errors of having avoided incremental encoder to exist are simultaneously owing to used the switching mode magneto sensor, high conformity is produced debugging conveniently;

2, use interrupter-type magnetic field detection mode, the accuracy of detection height, in 125 ℃ temperature range, the positional repeatability of groove can reach 50 μ m;

3, use central processing element, the number of turns that the record code-disc turns over realizes absolute type multi-turn coding, has cancelled gear set, not wearing and tearing, and long service life, the basic element of character is few, and is simple in structure, the reliability height.

Description of drawings

Fig. 1 is a structural representation of the present invention,

Fig. 2 is the code-disc structural representation.

Fig. 3 is the code-disc state transition graph.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further described by embodiment.

Embodiment 1:

The absolute type multi-coil magnetic encoder comprises shell 1, main shaft 8, metal code disk 12, magneto sensor and data processing unit 6.Metal code disk 12 is fixed on the main shaft 8 by sleeve 9, rotate with main shaft 8, magnet steel 13 and magneto sensor 10, magneto sensor 11 are installed in respectively on the printed-wiring board (PWB) 2 and printed-wiring board (PWB) 4 on metal code disk 12 both sides, its number is determined by the fluting number of turns of metal code disk 12, printed-wiring board (PWB) 2 and printed-wiring board (PWB) 4 are fixed together with housing by snap ring 3 and snap ring 5, do not rotate, be used to detect the position that metal code disk turns over main shaft; Data processing unit 6 is installed on the bonnet 7, is connected by lead between data processing unit 6 and magneto sensor 10, the magneto sensor 11, sees Fig. 1.

Metal code disk is discoid for distortion, it directly upwards is provided with four circular arcs, wherein circular arc 14 and circular arc 16 are located at the relative both sides of same radius, and arc length equates, between circular arc 14 and the circular arc 16 adjacent sides is interior concave arc 15, is provided with interior concane gap between the opposite side, and interior concane gap is provided with interior concave ring groove along circular arc 16 1 sides, interior concane gap circular arc limit and the interior trough rim of the annular groove that links to each other are circular arc 17, see Fig. 2.

Metal code disk one week design is divided into four calibration, encodes according to the ordinary binary mode when slotting on the code-disc, when code-disc rotates, circular arc 14, circular arc 15, circular arc 16, circular arc 17 passes through respectively in the middle of magnet steel and the Hall element.When circular arc 14 was between magnet steel and Hall element, owing to do not slot on this position code-disc, magnetic field was interdicted, and two Hall elements all detect less than magnetic field, are designated as state 0; When circular arc 15 was between magnet steel and Hall element, because outside fluting makes Hall element 11 detect magnetic field, Hall element 10 detected less than magnetic field, is designated as state 1; In like manner, when circular arc 16 was between magnet steel and Hall element, Hall element 11 detected less than magnetic field, and Hall element 10 detects magnetic field, is designated as state 2; When circular arc 17 was between magnet steel and Hall element, two Hall elements can both detect magnetic field, are designated as state 3.When code-disc rotated, central processing unit can be judged the position of code-disc and the number of turns that turns over according to the detected state variation of Hall element, and determination methods is:

Last detected state	This detected variation back state	The implication of state variation
			State 0	State 1	Just changeing a calibration, the number of turns is constant
State
	1	State 2	Just changeing a calibration, the number of turns is constant
State
	2	State 3	Just changeing a calibration, the number of turns is constant
State
	3	State 0	Just changeing a calibration, the number of turns adds 1
State 1				State 0	The calibration that reverses, the number of turns is constant
	State
2		State 1	The calibration that reverses, the number of turns is constant
	State
3		State 2	The calibration that reverses, the number of turns is constant
	State 0			State 3	The calibration that reverses, the number of turns subtracts 1

Other structure is with embodiment 1.

Magneto sensor is chosen as hall ic (also claiming Hall element).On the both sides of metal code disk, the Hall element that is provided with two shape of a hoof magnet steel and two low-power consumption is used for detecting the groove on the code-disc; Hall element links to each other with central processing unit on the data processing unit, makes central processing unit can obtain the detected state variation of Hall element, through obtaining the angle and the number of turns that code-disc rotates after the data analysis; Data processing unit 6 comprises central processing unit, rechargeable battery, interface chip, chargeable battery guarantees under the situation of no external power source, the data processing unit endure, can not cause losing of data message, interface chip provides communication port for external unit, makes external unit can obtain the detected data of the present invention.

Because central processing unit and Hall element are all low energy-consumption electronic device, can use powered battery, therefore the rotation of code-disc still can be detected under power down mode, thereby has realized absolute type multi-turn coding.

Concrete principle of work is as follows:

The switching mode magneto sensor is at the notch correspondence position of code-disc, Yi Bian the horseshoe type magnet steel is installed, it is corresponding with it that another side is equipped with magneto sensor, is used to detect the position of code-disc.The principle that magneto sensor detects the code-disc rotation is an interrupter-type magnetic field detection method, promptly in the code-disc rotation process, when the metal of code-disc partly forwards shape of a hoof magnet steel and magneto sensor centre to, magnet steel and code-disc form magnetic loop, blocked the magnetic line of force that passes magneto sensor, magneto sensor is detected less than magnetic field, and when the slot-open-section of code-disc forwarded shape of a hoof magnet steel and magneto sensor centre to, magneto sensor was passed in magnetic field; Magneto sensor is according to having or not magnetic field, output digital signal ' 0 ', ' 1 ', this signal is connected via wires to the input end of central processing unit, and central processing unit is judged the residing position of code-disc in view of the above, differentiates rotation direction, the number of turns that accumulative total turns over, thus realize the absolute multi-turn coding.

Central processing unit and magneto sensor are the low-power consumption element, and its power supply is a battery, the rotation that still can write down code-disc when not having externally fed with assurance.

Claims (1)

1, absolute type multi-coil magnetic encoder comprises shell, main shaft, metal code disk, magneto sensor and data processing unit, and metal code disk is fixedly installed on the main shaft, and the magneto sensor correspondence is located on the printed circuit board (PCB) of the axial side of metal code disk, it is characterized in that:

Described metal code disk is discoid for distortion, it directly upwards is provided with four circular arcs, wherein circular arc 14 and circular arc 16 are located at the relative both sides of same radius, and arc length equates, between circular arc 14 and the circular arc 16 adjacent sides is interior concave arc 15, be provided with interior concane gap between the opposite side, interior concane gap is provided with interior concave ring groove along circular arc 16 1 sides, and interior concane gap circular arc limit and the interior trough rim of the annular groove that links to each other are circular arc 17.

Images