JPH0454322A - Magnetic particle type electormagnetic connection device - Google Patents

Abstract

PURPOSE:To detect a rotation toque correctly by fixing high magnetic permeability soft magnetic materials to the surface of a drive rotation shaft, providing a magnetism shielding layer selectively in its surface, and sending a magnetic flux to the magnetic layer in parts where the magnetism shielding layer is not formed, and detecting a change of the magnetic permeability. CONSTITUTION:Magnetic particles 10 are filled in a circular cavity between a drive member 7 of a first connection main body of a drive rotation shaft 29 and a driven member of a second connection main body of a driven shaft 11, and they are magnetized by an excitation coil 2 to connect them with each other. High magnetic permeability soft magnetic materials are fixed to the circumference of the drive rotation shaft 29 uniformly, a magnetism shielding layer 50 is fixed on it uniformly, rectangular cut parts are provided at parts corresponding to detection coils 37, 38 and magnetic layers 31, 32 are formed by the exposed parts of the high magnetic permeability soft magnetic material. Changes in the magnetic permeability for the magnetic layers 31, 32 generated by a torque by the drive rotation shaft 29 are detected by the detection coils and a detection circuit 41. In this constitution, the magnetic layers can be processed uniformly without generating thermal stress, and torque detection precision is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic particle type electromagnetic coupling device having a torque detection function.

[Conventional technology]

Figure 6 shows a conventional magnetic particle type 9M1 coupling device, where 1 is a stator, 2 is an excitation coil built into the stator 1, and 3 is a magnetic particle type 9M1 coupling device.
3 is a bracket that supports the stator 1, and a bearing 3
4.35 to rotatably support the drive rotation shaft 29. 7 is a drive member that is fixed to the drive rotating shaft 29 and is provided inside the stator 1 with a predetermined gap therebetween; 8 is a plate that is fixed to the end of the drive member 7; 9; 1 is a driven member constituting a second connecting body provided inside the drive member 7 through a predetermined radial annular gap; 10 is a magnetic particle filled in the annular gap; 11 is a driven member fixed to the trigger member 9; The driven rotating shaft 12 is a bracket that is fixed to the stator 1 and rotatably supports the driven rotating shaft 11 via hair rings 13 and 14.

Next, the operation will be explained. When the drive rotation shaft 29 connected to a drive shaft (not shown) is rotated and the drive member 7 is rotating together with this drive rotation shaft 29, when current is passed through the excitation coil 2 built in the stator 1, as shown in the figure. A magnetic flux Φ is generated as shown by the dotted line. The magnetic particles 10 constituting a part of the magnetic path are connected in a chain between a rotating drive member 7 and a stationary driven member 9,
The driven member 9 also rotates, and the driven rotating shaft 11 coupled to the load side rotates. Here, when the current in the excitation coil 2 is cut off, the magnetic flux Φ disappears, the chain-like connection of the magnetic particles 10 is broken, and the trifun member 9 becomes free. Note that the transmitted torque value is approximately linearly proportional to the current value flowing through the exciting coil 2.

Further, 30 is the central axis of the drive rotation shaft 29, 31.32 is a magnetic layer made of a high magnetic permeability soft magnetic material fixed on the outer peripheral surface of the drive rotation shaft 29, and the magnetic layer 31 is oriented toward the center axis 30. +4
The magnetic 1i32 is formed in the 5'' direction and the 45' direction. 36 is a coil bobbin disposed around the magnetic layer 31, 32, 37.38 is a detection coil wound around the coil bobbin 36, 39.40 is the detection coil 37.
A magnetic convergence layer made of a high magnetic permeability soft magnetic material is provided around 38, and 41 is a detection circuit.

When torque is applied to the drive rotation shaft 29, the magnetic layer 31.3
2, the magnetic permeability of each changes in the opposite direction, and in response, the detection coils 37 and 38 generate outputs, and the detection circuit 41 differentially amplifies these outputs and applies them to the above torque. Generate output accordingly.

[Problem to be solved by the invention]

However, in the conventional device described above, the drive rotation shaft 29
Since there is a large difference in linear expansion coefficient between the magnetic layer 3132 and the magnetic layer 3132 fixed to the surface thereof, thermal stress is generated in the magnetic layer 31, 32, and this thermal stress is superimposed on the stress generated by strain. However, there is a problem in that it is not possible to accurately measure the amount of strain, that is, the amount of torque. Further, the magnetic layers 31 and 32 need to be formed into strips, but since the magnetic layers 31 and 32 are made of a relatively hard material, there is a problem in that it is not easy to process.

This invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to obtain a magnetic particle type 1i magnetic coupling device which can accurately detect the amount of torque of a drive rotating shaft and whose magnetic layer can be easily processed. With the goal.

[Means to solve the problem]

Magnetic particle type according to this invention! The magnetic coupling device includes a drive rotating shaft made of a non-magnetic material fixed to a first coupling main body, a high magnetic permeability soft magnetic material fixed to the surface of the drive rotating shaft, and a high magnetic permeability soft magnetic material fixed to the surface of the high magnetic permeability soft magnetic material. A magnetic flux is passed through a selectively formed magnetic shielding layer made of a non-magnetic or diamagnetic high conductivity material and a magnetic layer formed in a high permeability soft magnetic material in the area where the magnetic shielding layer is not formed, thereby causing distortion. It is equipped with a magnetic drive source that detects changes in magnetic permeability.

Further, the magnetic particle type electromagnetic coupling device according to the present invention has a first
A rotating shaft made of a high magnetic permeability soft magnetic material fixed to the connecting main body of the drive rotating shaft, a magnetic shielding layer made of a non-magnetic or diamagnetic high conductivity material selectively formed on the surface of the driving rotating shaft, A magnetic drive source is provided for passing a magnetic flux through a magnetic layer formed in a portion of the shaft where a magnetic shielding layer is not formed, and detecting a change in magnetic permeability due to strain.

[Function] In the present invention, a magnetic layer is formed on the high magnetic permeability soft magnetic material or the portion of the drive rotating shaft where the magnetic shielding layer is not formed.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure shows a sectional view according to a first embodiment of the invention, and a second embodiment of the invention.
3 and 3 show an enlarged sectional view and an enlarged front view of the torque detection portion. 29 is a drive rotating shaft made of a non-magnetic material such as stainless steel; 52 is a high magnetic permeability soft magnetic material fixed uniformly around the drive rotating shaft 29; 50 is a high magnetic permeability soft magnetic material 52
A magnetic shielding layer uniformly fixed on top, e.g. Au,
It is made of a non-magnetic or diamagnetic material such as NCu, Ag, or Pt and has high conductivity. This magnetic shielding layer 50
A plurality of strip-shaped cutout portions 50a and 50b are provided in portions corresponding to the detection coils 37 and 38, and the cutout portions 50
The high magnetic permeability soft magnetic material 52 exposed from a and 50b forms strip-shaped magnetic layers 31 and 32.

The operation of magnetically connecting 1 in the above device is the same as the conventional one.

On the other hand, even in the torque detection operation, since the magnetic shielding layer 50 is non-magnetic or diamagnetic, there is no influence of magnetic variations or magnetization, and the magnetic layer 31 consisting of the exposed portion of the high magnetic permeability soft magnetic material 52. 32 has the same function as the conventional one, and can perform the same torque detection as the conventional one. Moreover, the magnetic layer 31
．． Since the shape of 32 is determined by the magnetic shielding layer 50, the magnetic layers 31 and 32 do not require etching, making their formation easy. Note that the magnetic shielding layer 50 can also be used as a collar for hair rings 34 and 35.

FIGS. 4 and 5 show an enlarged sectional view and an enlarged front view of a torque detection portion of a device according to a second embodiment of the present invention,
In this embodiment, the drive rotation shaft 29 is made of a soft magnetic material with high magnetic permeability such as permalloy.
A magnetic shielding layer 50 made of a non-magnetic or diamagnetic highly conductive metal is fixed around the magnetic shielding layer 50, and strip-shaped cutout portions 50a and 50b are provided in the magnetic shielding layer 50 in correspondence with the detection coil 3738. A magnetic layer 3132 is formed on the exposed portion of the shaft 29. In this case as well, the torque detection operation similar to the conventional one can be performed. In addition, the present embodiment has the same effects as the first embodiment, and since the magnetic layers 31 and 32 are made of the same member as the drive rotating shaft 29, no thermal stress is generated, and torque detection accuracy can be improved.

〔Effect of the invention〕

As described above, according to the present invention, since the magnetic layer is formed on the high magnetic permeability soft magnetic material or the portion of the drive rotating shaft where the magnetic shielding layer is not formed, the shape of the magnetic layer is determined by the magnetic shielding layer, and the magnetic layer is processed. becomes easier. Furthermore, according to this invention, since the drive rotating shaft itself becomes a magnetic layer, no thermal stress is generated.
Torque detection accuracy can be improved. Moreover, the magnetic shielding layer can also be used as a hair ring collar.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the inventive device, FIGS. 2 and 3 are an enlarged sectional view and an enlarged front view of the torque detection portion of the first embodiment of the inventive device, and FIG. 5 are an enlarged sectional view and an enlarged front view of a torque detection portion according to a second embodiment of the device of the present invention, and FIG. 6 is a sectional view of a conventional device. 2... Excitation coil, 7... Drive member, 9...
- Driven member, 10... Magnetic particle, 29... Drive rotation shaft, 31.32... Magnetic layer, 37.38...
Detection coil, 50... Magnetic shielding layer, 52... High magnetic permeability soft magnetic material. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A first connecting entity, a second connecting entity arranged to be connectable to the first connecting entity, and magnetic particles filled between the first and second connecting entities; An excitation coil that is magnetized to transmit torque between each connecting body, a drive rotation shaft made of a non-magnetic material fixed to the first connection body, and a high permeability soft magnetic material fixed to the surface of the drive rotation shaft. , a magnetic shielding layer made of a nonmagnetic or diamagnetic high conductivity material selectively formed on the surface of the high magnetic permeability soft magnetic material, and a magnetic shielding layer formed on the part of the high magnetic permeability soft magnetic material where the magnetic shielding layer is not formed. What is claimed is: 1. A magnetic particle type electromagnetic coupling device comprising a magnetic drive source that passes a magnetic flux through a magnetic layer and detects a change in magnetic permeability due to strain. (2) A first connecting body, a second connecting body disposed so as to be connectable to the first connecting body, magnetic particles filled between each connecting body, and magnetic particles that are magnetized to each other. An excitation coil that provides a transmission torque between the connecting bodies, a drive rotating shaft made of a high permeability soft magnetic material fixed to the first connecting body, and a non-magnetic or antimagnetic material selectively formed on the surface of the drive rotating shaft. Equipped with a magnetic shielding layer made of a magnetic high-conductivity material and a magnetic drive source that passes magnetic flux through the magnetic layer formed in the portion of the drive rotating shaft where the magnetic shielding layer is not formed to detect changes in magnetic permeability due to strain. A magnetic particle type electromagnetic coupling device featuring: