JP2556177B2 - Magnetic particle type electromagnetic coupling device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic clutch that connects two rotating bodies via magnetic particles, and more particularly to a magnetic particle type electromagnetic coupling device that can detect torque with the clutch itself. Is.

[Conventional technology]

FIG. 3 shows a cross-sectional view of a conventional magnetic particle type electromagnetic coupling device, in which 1 is a stator which is a fixed body, and 2 is a stator.
Is a magnetizing coil incorporated in the stator 1, and 3 is a bracket for supporting the stator 1, which supports the drive shaft 6 via bearings 4 and 5. 7 is attached to the drive shaft 6,
A drive member, which is a first connecting main body and is arranged on the inner diameter side of the stator 1 with a predetermined gap, is a plate fixed to the end of the drive member 7, and 9 is an inner diameter side of the drive member 7. A driven member serving as a second connecting main body disposed through a predetermined gap, 10 is a magnetic particle filled in the gap between both members 7 and 9, and 11 is fixed to the driven member 9 and the drive shaft. 6 and a driven shaft arranged on one axis, and 12 is a bracket which is fixed to the stator 1 and rotatably supports the driven shaft 11 via bearings 13 and 14.

Next, the operation will be described. When the drive shaft 6 is rotationally driven by a drive source (not shown), and the drive member 7 is integrally rotated with the drive shaft 6, when a current is passed through the exciting coil 2 incorporated in the stator 1, a dotted line in FIG. As shown, the time flux Φ is generated. As a result, the magnetic particles 10 that are a part of the magnetic path are connected in a chain between the rotating drive member 7 and the stopped driven member 9, whereby the driven member 9 is rotated and the driven shaft 11 is rotated. Is also rotated. When the current to the exciting coil 2 is cut off, the magnetic flux Φ disappears, the chain-like connection of the magnetic particles 10 is released, and the driven member 9 becomes free. The torque value transmitted from the drive member 7 to the driven member 9 is almost linearly proportional to the value of the current flowing through the exciting coil 2.

[Problems to be Solved by the Invention]

Since the conventional magnetic particle type electromagnetic coupling device is configured as described above, torque management or control is performed according to the value of the exciting current. Therefore, if the relationship between the exciting current and the torque changes due to variations in products of the electromagnetic coupling device, deterioration of powder (magnetic particles), or changes over time, there is a problem that sufficient torque management and control cannot be performed. Further, in order to perform sufficient torque management, a torque detector must be separately provided outside the electromagnetic coupling device, resulting in a problem that the configuration becomes complicated and expensive.

FIG. 4 is a perspective view showing an embodiment using a torque detector and an electromagnetic coupling device. In the figure, 15 is a motor as a drive source, and 16 is a magnetic particle type electromagnetic shown in FIG. In the coupling device, the driven shaft that is the output shaft of this electromagnetic coupling device 16.
Belt between the pulley 17 attached to 11 and the pulley 18 of the winding shaft 20.
A film material 21 is wound around the winding shaft 20. 22 is a tension roller of the film material 21,
Reference numerals 23 and 24 are detectors for detecting the tension of the film material 21, which are detected by the detection roller 25. Numerals 26 and 27 are rollers that give tension to the detection rollers, and numeral 28 is a control device for receiving a command from the detectors 23 and 24 and changing the current to the electromagnetic coupling device 16.

Therefore, according to the above configuration, the detectors 23 and 24 for detecting the tension on the left and right of the film 21 are required, and the rollers 26 and 27 for further imparting the tension are also required, which makes the configuration complicated and expensive. It was In some places, the detector cannot be attached, and in this case, the winding operation cannot be performed accurately because the driver operates according to the feeling.

The present invention has been made to solve the above problems, and an object thereof is to obtain a small and inexpensive magnetic particle type electromagnetic coupling device capable of easily detecting torque and performing sufficient torque management and control. To do.

[Means for solving the problem]

A magnetic particle type electromagnetic coupling device according to the present invention includes a first coupling body, a rotating shaft to which the first coupling body is fixed,
A bearing that supports the rotary shaft at at least two positions in the axial direction, and a second bearing that is arranged to be connectable to the first connecting body.
In the magnetic particle type electromagnetic coupling device including the coupling main body, the magnetic particles filled between the two coupling main bodies, and the exciting coil that magnetizes the magnetic particles to give a transfer torque between the coupling main bodies, A magnetic part made of a magnetic material provided on the part of the rotating shaft, a coil means provided facing the magnetic part with a predetermined gap, and a torque for detecting a transmission torque based on an output from the coil means. And a detection means.

[Work]

Since the magnetic particle type electromagnetic coupling device of the present invention uses the non-contact type torque sensor, the torque can be stably detected over a long period of time. Further, since the magnetic portion and the coil means are provided between the bearings, the conventional dead space is eliminated. The space between the bearings was used to reduce the size of the device, and an accurate torque value can be measured without being affected by slip heat or magnetic flux. Torque management and control are performed by this torque value. be able to.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a magnetic particle type electromagnetic coupling device according to the present invention. In the figure, the same parts as those in the conventional electromagnetic coupling device described in FIG. To do. In the figure, 29 is a drive shaft, to which the drive member 7 is attached. Reference numeral 30 denotes the axis center of the drive shaft 29, and 31 and 32 denote magnetic layers made of a high magnetic permeability soft magnetic material attached to the outer peripheral surface of the drive shaft 29. The magnetic layer 31 is oriented at + 45 ° with respect to the axis center 30. ,
The magnetic layers 32 are each formed in the direction of -45 °. 33
Is a bracket fixed to the stator 1 and rotatably supports the drive shaft 29 via bearings 34 and 35. 3
6 is a coil bobbin arranged on the inner diameter side of the bracket 33, 3
7,38 is a detection coil wound around the coil bobbin 36, 39,40
Is a magnetic focusing layer provided around the detection coils 37 and 38,
It is made of high permeability magnetic material. Reference numeral 41 is a detection circuit connected to the detection coils 37 and 38, and its block diagram is shown in FIG. The detection circuit 41 is a generally known inductance differential amplifier circuit, and description of its contents will be omitted.

Next, the operation of the present invention will be described. Excitation coil 2
A magnetic flux Φ is generated by passing an electric current through the magnetic particles 10, whereby the magnetic particles 10 are magnetized and are connected in a chain shape between the drive member 7 and the driven member 9, and the drive member and the driven member 9 are connected to each other to form a drive shaft. Power is transmitted from 29 to the driven shaft 11. Here, torque for power transmission is applied to the drive shaft 29, a tensile force is generated in one of the magnetic layers 31 and 32, and a compressive force is generated in the other, which causes strain. When this strain occurs, the magnetic permeability changes, and the magnetic permeability changes in the opposite direction between the tensile force and the compressive force. Detection coil 37,38
Detects this change in magnetic permeability as a change in impedance magnetically, and the detection circuit 41 differentially amplifies the output of each detection coil 37, 38 and outputs a detection voltage corresponding to the amount of distortion of the drive shaft 29, that is, the torque. .

Here, the magnetic layers 31 and 32 are provided between the bearings 34 and 35, and the span of this bearing is a space necessary for supporting the drive shaft 29 and extending the life of the bearing. Since the magnetic layers 31 and 32 are provided in this space in the present invention, the device itself can be compactly incorporated without increasing the size. Further, it is not necessary to mount the detector on the machine shown in the conventional device, and since the detector is provided inside the coupling device even where it cannot be mounted, torque control is facilitated and the mechanical device can be manufactured at low cost. The apparatus shown in the figure can accurately wind the film material.

As described above, in the embodiment of the present invention, the detection coil 37, between the bearings 34, 35 on the side of the drive shaft 29, which is conventionally a space,
38 is provided, and the magnetic layer 3 is provided on the outer peripheral surface of the drive shaft 29 inside thereof.
Since 1,32 are fixed, the size of the entire device does not increase.

In the above embodiment, the torque detection method is the magnetostrictive method, but a phase difference detection method or the like may be used.
Furthermore, although the case where the magnetic particle type electromagnetic coupling device is applied to the clutch device is shown, it may be applied to the brake device.
In this case, the driven shaft may be fixed.

〔The invention's effect〕

As described above, according to the present invention, the magnetic portion made of a magnetic material provided at the portion of the rotating shaft between the bearings, and the coil means provided to face the magnetic portion with a predetermined gap therebetween. Since the torque detection means for detecting the transmission torque based on the output from the coil means is provided, the transmission torque can be accurately detected for a long period of time without increasing the size of the device.

[Brief description of drawings]

FIG. 1 is a sectional view of a magnetic particle type electromagnetic coupling device according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of a detection circuit, and FIG. 3 is a sectional view of a conventional magnetic particle type electromagnetic coupling device.
FIG. 4 is a perspective view showing an example of use of the conventional device. 1 ... Stator, 2 ... Excitation coil, 7 ... Drive member, 9 ... Driven member, 10 ... Magnetic particles, 11 ...
Driven shaft, 29 …… Drive shaft, 31,32 …… Magnetic layer, 34,35 …… Bearing, 37,38 …… Detecting coil, 39,40 …… Magnetic converging layer, 41 …… Detecting circuit. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A first connecting main body, a rotary shaft to which the first connecting main body is fixed, a bearing that supports the rotary shaft at at least two axial positions, and the first connecting main body. Magnetic particles provided with a second connecting main body arranged so as to be possible, magnetic particles filled between the two connecting main bodies, and an exciting coil for magnetizing the magnetic particles to give a transfer torque between the connecting main bodies. In the electromagnetic coupling device, a magnetic part made of a magnetic material is provided at a portion of the rotary shaft between the bearings, a coil means provided to face the magnetic part with a predetermined gap, and a coil means. And a torque detecting means for detecting a transmission torque based on the output of the magnetic particle type electromagnetic coupling device.