JPH0464733A - Magnetic particle type electromagnetic coupling device - Google Patents

Abstract

PURPOSE:To detect a torque without increasing the size of a magnetic particle type electromagnetic coupling device, to perform sufficient torque management or control by incorporating a torque detector in the magnetic particle type electromagnetic coupling device. CONSTITUTION:An exciting coil 2 is energized so that a magnetic flux PHI is generated, and accordingly, magnetic particles 10 are magnetized so as to be connected in a chain-like manner between a drive member 7 and a driven member 9 which are accordingly coupled with each other so as to transmit a power from a drive shaft 29 to a driven shaft 11. In this arrangement, a torque corresponding to the transmitted power is applied to the drive shaft 29 so that a tension is effected in one of magnetic layers 31, 32 and a compression is effected in the other thereof, resulting in generation of a strain. This strain causes the magnetic permeability to vary, that is, the magnetic permeabilities caused by the tension and the compression vary in opposite directions, respectively. Detecting coils 37, 38 detects variations in these magnetic permeabilities as variations in impedance, and a detection circuit 41 amplifies a difference between outputs from the detecting coils 37, 38 and delivers a detection voltage in accordance with the value of a strain in the drive shaft 29 or a torque.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tMi clutch that connects two rotating bodies via magnetic particles, and particularly relates to a magnetic particle type electromagnetic coupling device that can detect torque in the clutch itself. It is.

[Prior Art] Fig. 3 shows a cross-sectional view of a conventional magnetic particle type electromagnetic coupling device. This bracket supports the stator l and supports the drive shaft 6 via a bearing 4.5. 7 is attached to the drive shaft 6,
A drive member serving as a first coupling body is arranged on the inner diameter side of the stator 1 with a predetermined gap in between, 8 is a plate fixed to the end of the drive member 7, and 9 is on the inner diameter side of the drive member 7. A driven member serving as a second connection body is disposed through a predetermined gap, 10 is a magnetic particle filled in the gap between the two members 7 and 9, and 11 is fixed to the driven member 9 and connected to the drive shaft. A driven shaft 12 is fixed to the stator 1 and rotatably supports the driven shaft 1 through bearings 13 and 14.

Next, the operation will be explained. When the drive shaft 6 is rotationally driven by a drive source (not shown) and the muco drive member 7 is rotating together with it, the 11J built in the stator I [coil 2 When the current flows, a magnetic flux Φ is generated as shown by the dotted line in FIG. The driven member 9 is rotated by being connected in a chain between
is also rotated. Note that when the current to the excitation 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. Further, the torque value transmitted from the drive member 7 to the driven member 9 is approximately linearly proportional to the t current value flowing through the exciting coil 2.

[Problem 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 based on the value of the excitation current. Therefore, if the relationship between the excitation current and the torque changes due to product variations in the electromagnetic coupling device, deterioration of the powder (magnetic particles), or changes over time, there is a problem in that sufficient torque management and control cannot be performed. Further, in order to perform sufficient torque management, a torque detector must be provided separately outside the magnetic coupling device, resulting in a problem that the configuration becomes complicated and expensive.

FIG. 4 is a perspective view showing one embodiment equipped with a torque detector and using an electromagnetic coupling device. In the coupling device, a belt 19 is wound between a pulley 17 attached to a driven shaft 11 serving as an output shaft of the magnetic coupling device 16 and a pulley 18 of a winding shaft 20. The material 21 is wound up. 22 is the tension roller of the film material 21, 23.24 is the film material 21
The tension is detected by the detection roller 25. 26. ．． 27 is a roller that applies tension to the detection roller; 28 receives commands from the detectors 23 and 24; A control arrangement for varying the current to the magnetic coupling device 16.

Therefore, according to the above configuration, detectors 23, 24 for detecting tension are required on the left and right sides of the film 21, and rollers 26, 27 for applying tension are also required, which makes the configuration complicated and expensive. Ta. Further, depending on the location, it may not be possible to install a detector, and in this case, the winding operation may not be accurate because the winding operation relies on a rough feeling.

This invention was made to solve the above-mentioned problems, and the purpose is to obtain a small and inexpensive magnetic particle type 1M1 coupling device that can easily detect torque and perform sufficient torque management and control. do.

[Means to solve the problem]

The magnetic particle type electromagnetic coupling device according to the present invention includes a first coupling body, a second coupling body disposed so as to be connectable with the first coupling body, and a magnetic particle filled between the two coupling bodies. A magnetic particle type electromagnetic coupling device comprising particles and an excitation coil that magnetizes the magnetic particles and applies a transmission torque between the coupling bodies, characterized in that the device has a built-in torque detector.

[Function] The magnetic particle type electromagnetic coupling device of the present invention has a torque detector built into the device, so that accurate torque values can be measured, and torque management and control can be performed using this torque value.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure shows a cross-sectional view of the magnetic particle type tM1 coupling device according to the present invention, and in the figure, the same parts as those of the conventional af111 coupling device explained in FIG. In the figure, 29 is a drive shaft to which the drive member 7 is attached.

30 is the axis center of the drive shaft 29, 31.32 is the drive shaft 2
The magnetic layer 31 is formed in the +45'' direction with respect to the axis center 30, and the magnetic layer 32 is formed in the -45'' direction with respect to the axial center 30. . 33 is a bracket fixed to the stator 1;
A drive shaft 29 is rotatably supported via bearings 34 and 35. 36 is a coil bobbin arranged on the inner diameter side of the bracket 33, 37.38 is a detection coil wound around the coil bobbin 36, and 39.40 is this detection coil 37.
．． A magnetic convergence layer provided around 38 and made of a high permeability magnetic material. 41 is a detection circuit connected to the detection coils 37 and 38, a block diagram of which is shown in FIG. Note that this detection circuit 41 is a generally known inductance differential amplifier circuit, and a description of its contents will be omitted.

Next, the operation of this invention will be explained. A magnetic flux Φ is generated by passing a current through the excitation coil 2, and as a result,
[Magnetic particles] O are magnetized and connected in a chain between the drive member 7 and the driven member 9, and the drive member 7 and the driven member 9 are connected, and the drive shaft 29 is connected to the driven shaft 11.
Power is transmitted to. Here, torque for power transmission is applied to the drive shaft 29, and the magnetic layers 31, 32
A tensile force is generated on one side, and a compressive force is generated on the other side, causing distortion. When this strain occurs, the magnetic permeability changes, and the magnetic permeability changes in opposite directions when a tensile force is applied and when a compressive force is applied. The detection coils 37 and 38 magnetically detect this change in magnetic permeability as a change in impedance, and the detection circuit 41 differentially amplifies the output of each detection coil 37 and 38 to adjust the output according to the amount of distortion, that is, torque of the drive shaft 29. Outputs the detected voltage.

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 not only to support the drive shaft 29 but also to extend the life of the bearing. This invention provides a magnetic layer 31 in this space.
．． 32, the device itself can be built compactly without increasing its size. Furthermore, it is no longer necessary to install a detector in the machine shown in the conventional device, and even in places where it cannot be installed, it is installed inside the coupling device, which makes torque control easier and allows the mechanical device to be manufactured at a lower cost. In the device shown in the figure, the film material can be wound accurately.

As described above, in the embodiment of the present invention, the detection coils 37 and 38 are disposed between the hair rings 34 and 35 of the 29 drive shafts, which were conventionally spaces, and are placed on the outer peripheral surface of the drive shaft 29 inside the hair rings. Since the magnetic layers 31 and 32 are fixed, the overall size of the device does not increase.

In the embodiment, a case has been described in which the torque detector is provided on the drive shaft 29 side, but the same effect as described above can be obtained even if the torque detector is provided on the driven wheel 11 side. In addition, although the torque detection method has been explained using a magnetostrictive method, detection methods such as a phase difference method or a strain gauge method may also be used.Furthermore, the case where the magnetic particle type electromagnetic coupling device is applied to a clutch device has been explained. It can also be used in flake equipment. in this case,
Just fix the driven wheel.

〔Effect of the invention〕

As explained above, according to this invention, magnetic particle type! A torque detector is built into the magnetic coupling device, so
Torque detection is possible without increasing the size of the device itself, sufficient torque management or control can be performed, and it can be manufactured at low cost.

[Brief explanation 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. DESCRIPTION OF SYMBOLS 1... Stator, 2... Excitation coil, 7... Drive member, 9... Driven member, 10... Magnetic particle, 11... Driven shaft, 29... Drive shaft, 31. 3
2...Magnetic layer, 34.35...Bearing, 37.
38...Detection coil, 39.40...Magnetic convergence layer,
41...Detection circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent: Masu Oiwa ■ 9-tatami Figure 3

Claims (1)

[Claims] A first connecting entity, a second connecting entity arranged to be connectable to the first connecting entity, magnetic particles filled between the two connecting entities, and magnetizing the magnetic particles to create the connection. What is claimed is: 1. A magnetic particle electromagnetic coupling device comprising an excitation coil for transmitting torque between main bodies, characterized in that the device has a built-in torque detector.