CN212721467U - Code wheel and magnetic encoder - Google Patents

Abstract

The utility model discloses a code wheel and magnetic encoder, including metal framework and the magnetic layer of setting on metal framework, metal framework is the annular, the magnetic layer includes reference track and vernier track, the vernier track is located the reference track inboard, reference track and vernier track all are the annular and set up with one heart; the reference track comprises n pairs of magnetic poles, the vernier track comprises m pairs of magnetic poles, the number of the magnetic poles of the reference track and the vernier track is n which is m +1, and n is an integer which is more than or equal to 16. The magnetic pole positioning device can realize absolute positioning, has more magnetic pole pairs, and is more accurate in positioning precision.

Description

Code wheel and magnetic encoder

Technical Field

The utility model relates to an encoder technical field, concretely relates to code wheel and magnetic encoder.

Background

At present, the encoders widely used in the industrial field are mainly photoelectric encoders and rotary transformers.

The photoelectric encoder uses grating induction to generate signals, the photoelectric encoder separates a light source into two 90-degree out-of-phase light beams and penetrates through a transparent and uniform window to reach a rotating optical code disc, a stable signal is always dependent on a clear and continuous light beam, and any material pollution can block the light source and cause signal interference and code failure. In addition, the optical encoder is very vulnerable to shock and vibration, which can directly lead to damage to the rotating optical code pick-up. Therefore, the traditional solutions mainly include the packaging protection of the broadcast encoder, but unfortunately, the additional packaging protection not only increases the cost, but also increases the volume of the product, and the limitation on the application range is increased.

Rotary transformers are more stable than photoelectric encoders, typical brushless rotary transformers are often constructed with two stationary coils, up to 90 degrees mechanical phase difference, and one rotating or reference coil is used to compensate for the positive spin current provided by the rotary transformer. Once the rotation is established, the induced current in each stationary coil is measured and the relative signal strengths of the coils provide the corresponding positions. The material of structure and the mode of signal output create stability for resolver. While resolvers are almost immune to industrial environments, their control systems tend to be much more costly than photoelectric and magnetic encoders. In addition, the structure is complex, and the installation and maintenance are inconvenient.

In view of the various drawbacks associated with the two types of encoders described above, magnetic encoder solutions have been proposed.

The magnetic encoder mainly comprises a magnetic code disc and a Hall sensor, wherein a plurality of pairs of magnetic poles are uniformly distributed on the magnetic code disc, N poles and S poles are distributed in a staggered manner, magnetic fields of the N poles and the S poles alternate along with the rotation of the code disc to generate a pulse magnetic field, the Hall sensor can sense the change of the magnetic field, processes signals through a chip and outputs corresponding sine and cosine signals, and therefore the corresponding control function is achieved. Magnetic encoder can realize with photoelectric encoder and resolver similar function, but magnetic encoder is better than photoelectric encoder to the tolerance of environment, and magnetic encoder does not need clean transparent clearance, as long as contactless strong magnetic field, oil, water, dust, vibration impact etc. can not influence its output signal, and the distance between code wheel and the sensor chip can reach 4mm moreover, and the cooperation required precision is not high, so, the structural design of product has more probably. The magnetic encoder has long service life, simple structure and convenient installation, so that the magnetic encoder is much higher in cost performance.

At present, a code wheel of a traditional magnetic encoder only has one magnetic pole track, only a single sine and cosine signal can be output, only the rotating or moving speed and stroke can be controlled, and absolute position output cannot be realized.

Disclosure of Invention

The to-be-solved technical problem of the utility model is to provide a code wheel and magnetic encoder, it can realize absolute positioning, and the magnetic pole logarithm is many, and positioning accuracy is more accurate.

In order to solve the technical problem, the utility model provides a code wheel, including metal framework and the magnetic layer that sets up on metal framework, metal framework is the annular, the magnetic layer includes reference track and vernier track, the vernier track is located the reference track inboard, reference track and vernier track all are the annular and set up concentrically;

the reference track comprises n pairs of magnetic poles, the vernier track comprises m pairs of magnetic poles, the number of the magnetic poles of the reference track and the vernier track is n which is m +1, and n is an integer which is more than or equal to 16.

Preferably, n-16 × k is an integer of 1 or more.

Preferably, the magnetic layer is rubber mixed with magnetic powder.

Preferably, the rubber is NRR rubber.

Preferably, the reference track and the vernier track are obtained by magnetizing a magnetic material.

Preferably, an adhesive layer is provided between the magnetic layer and the metal skeleton.

Preferably, the bonding layer is a heat-curable adhesive.

Preferably, the lower end of the metal framework is provided with a chamfer.

The utility model discloses a magnetic encoder, including foretell magnetic encoder code wheel.

The utility model has the advantages that:

the utility model discloses upgrading current magnetic encoder's code wheel, having gone up the level by original monorail code wheel and has become the double track code wheel, forming reference track and vernier track, on the basis of control speed and stroke, making it realize absolute positioning, and the magnetic pole logarithm is many, and positioning accuracy is more accurate.

Drawings

Fig. 1 is a schematic diagram of the mechanism of the magnetic layer of the present invention;

fig. 2 is a sectional view of the code wheel of the present invention.

The reference numbers in the figures illustrate: 10. a metal skeleton; 20. a magnetic layer; 21. a cursor track; 22. a reference track.

Detailed Description

The present invention is further described with reference to the following drawings and specific embodiments so that those skilled in the art can better understand the present invention and can implement the present invention, but the embodiments are not to be construed as limiting the present invention.

Referring to fig. 1-2, the utility model discloses a code wheel, including metal framework 10 and the magnetic layer 20 of setting on metal framework 10, metal framework 10 is the annular, and magnetic layer 20 includes reference track 22 and vernier track 21, and vernier track 21 is located reference track 22 inboardly, and reference track 22 and vernier track 21 all are the annular and set up with one heart. The reference track 22 includes n pairs of magnetic poles, the vernier track 21 includes m pairs of magnetic poles, and the number of pairs of magnetic poles between the reference track 22 and the vernier track 21 satisfies n ═ m +1, where n is an integer greater than or equal to 16. And n is 16 x k, wherein k is an integer greater than or equal to 1.

As shown in fig. 1, a schematic diagram of the structure of the magnetic layer 20 is shown. The outer side is called the reference track 22 and has 32 pairs of magnetic poles, the inner side is called the cursor track 21 and has 31 pairs of magnetic poles. Each pole of the cursor track 21 is offset from the pole of the reference track 22, and the magnetic encoder can read these values to achieve absolute positioning.

The magnetic layer 20 is rubber mixed with magnetic powder. The rubber is NRR rubber. The NRR rubber mixed with the magnetic powder is directly molded with the metal skeleton 10 by a vulcanization process.

The reference rail 22 and the vernier rail 21 are obtained by magnetizing a magnetic material, permanently magnetize the magnetic layer 20, and form a magnetic pole distribution as shown in fig. 1. And a pair of magnetic poles are charged at one time through the charging head, the charging head is integrated by a pair of electrified coils, the winding directions of the adjacent coils are opposite, after the charging, the coils can generate a strong magnetic field, the magnetic material is magnetized by the strong magnetic field generated by the electrified coils to form a pair of magnetic poles, the winding directions of the adjacent coils are opposite, so that the directions of the generated magnetic fields are also different, and the charged magnetic poles are in staggered distribution of N poles and S poles. The utility model discloses in, the N utmost point after magnetizing and S utmost point naked eye can not watch, need just can watch the magnetic pole distribution of this code wheel through magnetic pole observation piece.

The magnetic layer 20 is provided with an adhesive layer between itself and the metal skeleton 10. The bond coat is a kelvin 205(Chemlok 205) hot cure adhesive.

The lower end of the metal framework 10 is provided with a chamfer angle, which is convenient for installation.

The utility model discloses magnetic encoder utilizes the slide caliper principle on the basis of current monorail code wheel, has increased a magnetic pole track, has made a double track way code wheel. We define the outer track as the reference track 22, typically having 16, 32, or 64 pairs of poles, and the inner track as the cursor track 21, the number of pole pairs being one pair less than the reference track 22, i.e. 15, 31, or 63 pairs, depending on the size of the code disc. The hall sensor integrated in the encoder will scan two separate tracks and determine the "binary code" of the different positions using the principle of a vernier caliper, thus providing an absolute position signal based on the reference track 22 and the vernier track 21.

The utility model has the advantages as follows:

1. the utility model discloses absolute position magnetic encoder code wheel has two tracks, and the benchmark way is used for the definition of high accuracy position, and vernier track 21 is than benchmark track 22 a pair of magnetic pole less, and like this, "uniqueness" of every position within the round has just been marked with the form of vernier by the different magnetic pole number on these two rails. Not only can control the rotating speed and the stroke, but also can realize accurate positioning.

2. The magnetic rubber material used by the utility model has very good tolerance to the environment, oil resistance, aging resistance, high and low temperature resistance, once the permanent magnet is magnetized, the permanent magnet can not be demagnetized as long as the permanent magnet does not meet a stronger magnetic field, and the service life is very long, so that the magnetic encoder has absolute advantages in severe environments;

3. the magnetic encoder of the utility model has simple structure, convenient installation and disassembly, low requirement on the relative assembly precision of the code disc and the sensor, great help to the structure optimization of the terminal product and high comprehensive cost performance;

4. the utility model discloses in, magnetic encoder's code wheel can be made various different sizes as required, and the commonality is also very strong.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. Equivalent substitutes or changes made by the technical personnel in the technical field on the basis of the utility model are all within the protection scope of the utility model. The protection scope of the present invention is subject to the claims.

Claims (9)

1. A coded disc is characterized by comprising a metal framework and a magnetic layer arranged on the metal framework, wherein the metal framework is annular, the magnetic layer comprises a reference track and a cursor track, the cursor track is positioned on the inner side of the reference track, and the reference track and the cursor track are both annular and concentrically arranged;

the reference track comprises n pairs of magnetic poles, the vernier track comprises m pairs of magnetic poles, the number of the magnetic poles of the reference track and the vernier track is n which is m +1, and n is an integer which is more than or equal to 16.

2. The code wheel of claim 1, wherein n-16 k, where k is an integer greater than or equal to 1.

3. The codewheel of claim 1 wherein said magnetic layer is rubber mixed with magnetic powder.

4. The codewheel of claim 3 wherein said rubber is NRR rubber.

5. The codewheel of claim 4, wherein the reference track and cursor track are obtained by magnetizing a magnetic material.

6. The code wheel of claim 1, wherein an adhesive layer is disposed between the magnetic layer and the metal skeleton.

7. The code wheel of claim 6, wherein the bonding layer is a heat-curable adhesive.

8. The code wheel of claim 1, wherein a lower end portion of the metal skeleton is provided with a chamfer.

9. A magnetic encoder comprising the magnetic encoder code wheel of any of claims 1-8.

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