JP6933978B2 - Torque generator - Google Patents

Description

The present invention relates to a torque generator capable of changing torque using a ferrofluid.

The brake described in Patent Document 1 includes a rotor, a shaft to which the rotor is connected and rotatable, a housing that supports the shaft and a magnetic field generator is arranged, a magnetic field controllable material (ferrofluid), and an electronic device. And have. In this brake, the magnetic field of the magnetic field generator acts on the ferrofluid around the rotor to suppress the rotation of the shaft.

Japanese Patent No. 5425269

In a torque generator that changes the torque in an operation unit such as a shaft by applying a magnetic field to a magnetically viscous fluid, such as the brake described in Patent Document 1, the operation feel is similar to that of physically stopping on a wall. There is a growing demand for both end-stop control that imparts a small torque control that imparts an appropriate frictional force corresponding to an operation feel with almost no resistance, and torque control within a range between these. However, Patent Document 1 does not describe in detail the control of the current applied to the magnetic field generator in order to control the torque generated in the ferrofluid, and the common control is performed regardless of the magnitude of the operation feel. it is conceivable that. In such a common control, for example, if the control suitable for the end stop control is applied to the minute torque control, the amount of change in torque is too large, so that the minute torque control cannot be substantially performed.

Therefore, an object of the present invention is to provide a torque generator capable of fine torque control corresponding to the magnitude of torque.

In order to solve the above problems, the torque generator of the present invention includes a ferrofluid whose viscosity changes according to an applied magnetic field, a coil portion that generates a magnetic field applied to the ferrofluid by energization, and a magnetic field. It is characterized by including an operation unit whose torque changes depending on the viscosity of the viscous fluid, a control unit that controls energization of the coil unit, and a switching means that can switch the upper limit value at which a magnetic field can be generated by the coil unit.
In this configuration, the upper limit value at which the magnetic field generated by the coil portion can be generated can be switched by the switching means, so that the torque control range can be changed according to the magnitude of the torque. It becomes possible to provide a generator.

In the torque generator of the present invention, the switching means includes a switching circuit for switching the upper limit value at which a magnetic field can be generated by the coil portion by switching the current range of energizing the coil portion, and the switching circuit is a switching signal from the control unit. It is preferable to be controlled by.
This makes it possible to switch the upper limit value at which the magnetic field generated by the coil portion can be generated with a simple configuration.

In the torque generator of the present invention, the switching means includes a current limiting element connected in series with the coil portion, and the switching circuit is a path passing through the current limiting element or a current limiting element by a switching signal from the control unit. It is preferable to be controlled to select one of the circuits that do not pass through.
In this configuration, by energizing the coil portion via the current limiting element, the applied current can be precisely controlled even in a range where the upper limit of the range of the applied current to the coil portion is small.

In the torque generator of the present invention, the coil unit is composed of a plurality of coils, and the switching means is a path for energizing a part of the plurality of coils or a plurality of coils by a switching signal from the control unit. It can also be configured to be controlled to select either one of the paths that energize the other part of it or all of the coils.
As a result, even if the current value for energizing the coil portion is the same, when energizing a part of a plurality of coils, the generated magnetic flux density becomes small, so that minute torque control can be performed more precisely. can. Further, the resistance of the coil to which the current is applied can be made different from that of other coils, so that the upper limit of the current value for energizing the coil portion can be changed.

In the torque generator of the present invention, the switching means includes a drive circuit connected to the coil unit and a plurality of different power supply voltage circuits, and a power supply unit that supplies power to the drive circuit by a switching signal from the control unit. It is preferable that the control is performed so that one power supply voltage circuit is selected from a plurality of power supply voltage circuits.
This makes it possible to switch the upper limit of the magnetic field generated by the coil portion with a simple configuration.

In the torque generator of the present invention, a housing in which the coil portion is fixedly arranged, a shaft portion as an operation portion that is pivotally supported by the housing so as to be rotatable, and a shaft portion that is fixed to the shaft portion and rotatably provided. A movable member and a rotation angle detecting means for detecting the rotation of the shaft portion are provided, and the control unit includes a storage unit that stores setting data for changing the torque applied to the shaft portion according to the rotation angle of the shaft portion, and a rotation unit. It has a torque calculation unit that calculates the torque applied to the shaft portion based on the detection result by the angle detection means and the setting data, and the switching means is switched according to the magnitude of the torque applied to the calculated shaft portion. It is preferable to control and control the current value that energizes the coil portion.
As a result, even in a configuration provided with a shaft portion or a movable member as an operation portion, the upper limit value of the magnetic field generated by the coil portion can be switched by the switching means, so that the torque can be controlled according to the magnitude of the torque. Since the range can be changed, fine torque control is possible and the operation feel of the operation unit is improved.

According to the present invention, it is possible to provide a torque generator capable of fine torque control corresponding to the magnitude of torque.

It is a vertical sectional view which shows the 1st structural example of the torque generator which concerns on embodiment of this invention. It is an exploded perspective view of the torque generator shown in FIG. It is a functional block diagram which shows the control circuit and the rotation angle detecting means in embodiment of this invention. It is an exploded perspective view of the 2nd structural example of the torque generator which concerns on embodiment of this invention. It is a functional block diagram in the torque generator of 1st Embodiment. It is a functional block diagram in the torque generator of the 2nd Embodiment. It is a functional block diagram in the torque generator of the 3rd Embodiment. It is a functional block diagram in the torque generator of 4th Embodiment. It is a functional block diagram in the torque generator of 5th Embodiment.

Hereinafter, the torque generator according to the embodiment of the present invention will be described in detail with reference to the drawings.
<Structure of torque generator>
First, the structure of the torque generator will be described with reference to the drawings. In the following description, when the shaft portion 111 of the operation unit 100 is rotated around the central shaft 11, the resistance due to the ferrofluid 160 via the magnetic disk 120 fixed to the tip portion 113 of the shaft portion 111. An example of a structure that receives a force is given, but the structure of the torque generator of the present invention is not limited to this.

<First structural example>
FIG. 1 is a vertical sectional view showing a first structural example of the torque generator according to the embodiment of the present invention. FIG. 2 is an exploded perspective view of the torque generator shown in FIG. FIG. 1 shows a cross section cut in a plane passing through the central axis 11.

The torque generator 10 includes a holding portion 20 (housing) and an operating portion 100 (movable member). The operation unit 100 includes a shaft unit 110 and a magnetic disk 120, and is integrally connected so as to rotate about a central shaft 11 (rotational shaft). The operation unit 100 is pivotally supported by the holding unit 20 in a state in which it can be rotationally operated via a support member 140, a radial bearing 151, and a pusher 152. Further, the gap 80 provided in the torque generator 10 is filled with the ferrofluid 160.

The holding portion 20 includes three yokes 31, 32, 33 as the first yoke, a second yoke 40, a coil 50 as a coil portion (magnetic field generating portion), a sealing member 60, and a first annular member. It includes 65, a second annular member 70, and a third yoke 90 as an upper case. As shown in FIG. 1, in the first direction D1 along the central axis 11, three yokes 31, 32, 33 as the first yokes are positioned on one side of sandwiching the magnetic disk 120, respectively, and sandwiches the magnetic disk 120. On the other hand, the second yoke 40 is combined so as to be located. The three yokes 31, 32, 33 as the first yoke, the second yoke 40, and the third yoke 90 are formed by being processed separately. However, any of these yokes may be combined and integrally formed.

As shown in FIG. 2, the coil 50 as the magnetic field generating portion has an annular shape. The coil 50 is a coil including a conducting wire wound around the central shaft 11. The coil 50 is fixedly arranged in the holding portion 20 (housing) by three yokes 31, 32, 33. A current is supplied to the coil 50 via a connecting member (not shown) with a waveform generated based on a control signal from the control circuit 200 (control unit) (FIG. 3). When a current is supplied to the coil 50, a magnetic field is generated.

FIG. 3 is a functional block diagram showing the control circuit 200 and the rotation angle detecting means 210 according to the embodiment of the present invention. The energization of the coil 50 is controlled by the control circuit 200. The control circuit 200 includes at least a storage unit 201 and a torque calculation unit 202. The storage unit 201 stores setting data for changing the torque applied to the shaft unit 111 according to the rotation angle of the shaft unit 111. The torque calculation unit 202 calculates the torque to be given to the shaft unit 111 based on the detection result by the rotation angle detecting means 210 and the setting data stored in the storage unit 201. The control circuit 200 outputs a pulse width modulation signal (PWM signal) to the drive circuit according to the magnitude of the torque calculated by the torque calculation unit 202, and also outputs an end stop signal as a switching signal to the switching means (FIG. FIG. Output to 5 to (see Fig. 9). As a result, the control circuit 200 controls the switching means and also controls the current value that energizes the coil 50. The DIR signal is a control signal that changes the direction of the current that energizes the coil 50.

The rotation angle detecting means 210 detects the rotation angle when the magnetic disk 120 rotates about the central axis 11. For example, from a light source that emits inspection light toward the magnetic disk 120 and the magnetic disk 120. It is composed of a light receiving element that receives the reflected light of.

As shown in FIG. 1, the first yoke is arranged on the inner side of the coil 50 (the side closer to the central axis 11) and the upper yoke 31 arranged on the upper side, and on the outer side of the coil 50 (the side far from the central axis 11). The outer yoke 32 and the lower yoke 33 arranged below the coil 50 are provided. These three yokes 31, 32, and 33 are arranged concentrically with respect to the central axis 11, and are arranged so as to be connected to each other so as to surround the coil 50.

A third yoke 90 is fixed to the upper side of the upper yoke 31, and a magnetic path surrounding the coil 50 is formed by the three yokes 31, 32, 33 as the first yoke and the third yoke 90.

An annular space is formed between the two yokes 32 and 33 facing each other in the radial direction (second direction D2) on the lower side of the coil 50, and the sealing member 60 is arranged in this space. This forms a magnetic gap. The sealing member 60 has an annular shape and is made of a non-magnetic material such as a synthetic resin. The sealing member 60 is arranged, for example, by filling the space with a fluid material and solidifying the material. Alternatively, the sealing member 60 may be arranged by press-fitting an elastic material formed in an annular shape in advance into the space. Further, the sealing member 60 may be formed by processing the non-elastic material into an annular shape and fixing it with an adhesive.

As shown in FIG. 2, the second yoke 40 has a disk shape and is arranged below the two lower yokes 32 and 33 of the first yoke. The second yoke 40 has an upper surface 41 orthogonal to the vertical direction along the central axis 11. The second yoke 40 is provided with an annular hole 42 that penetrates vertically at a position surrounding the central shaft 11. As shown in FIG. 1, a support member (pivot support member) 140 extending in the vertical direction is inserted in the hole 42, and the support member 140 is a holder 141 fixed to the lower surface 43 of the second yoke 40. Is fixed to the second yoke 40 by. The tip 113 of the shaft 110 is rotatably supported by the support member 140.

The bottom surfaces of the two lower yokes 32 and 33 of the first yoke and the bottom surface of the sealing member 60 form continuous surfaces in a direction orthogonal to the central axis 11, and these surfaces and the first yoke form a continuous surface. A gap 80 is formed between the two yokes 40 and the upper surface 41. In the gap 80, the magnetic disk 120 is arranged so as to extend along the radial direction orthogonal to the central axis 11, and the magnetic viscous fluid 160 is filled. The magnetic disk 120 is positioned so as to overlap with the coil 50 in the first direction D1 along the central axis 11.

Here, the magnetic viscous fluid 160 is a substance whose viscosity changes when a magnetic field is applied, and is, for example, a fluid in which particles (magnetic particles) made of a magnetic material are dispersed in a non-magnetic liquid (solvent). .. As the magnetic particles contained in the ferrofluid 160, for example, iron-based particles containing carbon and ferrite particles are preferable. As the iron-based particles containing carbon, for example, the carbon content is preferably 0.15% or more. The diameter of the magnetic particles is preferably 0.5 μm or more, more preferably 1 μm or more. For the magnetic viscous fluid 160, it is desirable to select a solvent and magnetic particles so that the magnetic particles are less likely to precipitate due to gravity. Further, the ferrofluid 160 preferably contains a coupling material that prevents the precipitation of magnetic particles.

In the radial direction, the first annular member 65 is arranged on the outside of the magnetic disk 120, and the second annular member 70 is arranged on the outside of the first annular member 65. Each of these annular members 65 and 70 has an annular shape centered on the central axis 11, is arranged concentrically, and is made of a non-magnetic material such as a synthetic resin. The inner peripheral surface of the second annular member 70 has a shape along the second yoke 40, and is fixed to the outer peripheral surface of the second yoke 40 and the bottom surface of the outer yoke 32, respectively. As a result, the outer yoke 32 and the second yoke 40 are connected to each other in the first direction D1 by the second annular member 70 extending along the first direction D1. In this way, the second annular member 70 connects the three yokes 31, 32, 33 as the first yoke and the second yoke 40 to each other, and the holding portion 20 is integrally fixed.
The second annular member 70 does not have to be entirely made of a non-magnetic material, and is a composite material having a non-magnetic part that does not magnetically short-circuit the outer yoke 32 and the second yoke 40. You may.

Further, the first annular member 65 is fixed to the inner peripheral surface of the second annular member 70, whereby the gap 80 is closed by the first annular member 65 in the radial direction. The first annular member 65 is arranged over the entire circumference so as to surround the magnetic disk 120 with a gap from the outer peripheral surface.

As described above, the coil 50 is formed by connecting the three yokes 31, 32, 33 of the first yoke and the third yoke 90, and further connecting the second yoke 40 with the magnetic disk 120 interposed therebetween. A magnetic path (magnetic circuit) that makes the generated magnetic field a closed loop is formed. In this configuration, when a current is applied to the coil 50, a magnetic field is formed so that the magnetic flux passes around the coil 50, and when a current is applied in the opposite direction to the coil 50, a magnetic field having a reverse flow is formed. .. For example, the magnetic flux from the upper yoke 31 and the lower yoke 33 toward the second yoke 40 along the direction of the central axis 11 passes through the magnetic disk 120 in the gap 80, and this magnetic flux is mainly in the second yoke 40. Proceed in the direction away from the central axis 11. Further, on the radial outer side of the second yoke 40, the process mainly proceeds from the bottom to the top along the direction of the central axis 11, that is, from the second yoke 40 to the outer yoke 32 side. On the upper side of the coil 50, this magnetic flux travels mainly from the outer yoke 32 side through the upper yoke 31 in the direction approaching the central axis 11, and from top to bottom in the region corresponding to the inside of the coil 50. , Proceeds in the upper yoke 31 and the lower yoke 33 of the first yoke, passes through the magnetic disk 120 again, and reaches the second yoke 40.

In such a magnetic path, a magnetic gap is provided between the outer yoke 32 and the lower yoke 33, and the sealing member 60 is arranged. In the vicinity of this magnetic gap, the magnetic flux of the magnetic field generated by the coil 50 is restricted from traveling from the lower yoke 33 toward the outer yoke 32 along the radial direction orthogonal to the central axis 11. As a result, the magnetic flux passing through the lower side or the lower yoke 33 of the upper yoke 31 surely travels downward to the second yoke 40 side, and the magnetic flux passing through the outer yoke 32 surely goes up to the second yoke. It proceeds from the yoke 40 side through the upper yoke 31 to the third yoke 90 side.

Next, the structure of the operation unit 100 will be described.
As shown in FIG. 1, the shaft portion 110 as the operation shaft is a rod-shaped member extending along the first direction D1 parallel to the central axis 11, and is on the upper side (upper side in FIG. 1) in the first direction D1. It has a shaft portion 111 and a flange portion 112 provided below the shaft portion 111. The flange portion 112 has a flange-like shape that extends outward from the outer peripheral surface of the shaft portion 111. The tip portion 113 provided at the center of the lower surface of the flange portion 112 has a shape that tapers toward the bottom.

As shown in FIG. 2, the magnetic disk 120 has a disk shape having a circular plane arranged so as to be orthogonal to the first direction D1, and is made of a magnetic material. The magnetic disk 120 is fixed to the shaft portion 110.

As shown in FIG. 1, in the shaft portion 110, the shaft portion 111 is rotatably supported by the radial bearing 151, and the tip portion 113 at the lower end of the flange portion 112 passes through the central hole portion 121 (see FIG. 2) of the magnetic disk 120. It is pivotally supported by a support member (pivot support member) 140. The radial bearing 151 is supported so as to be urged upward by the pusher 152, and the pusher 152 is maintained in the vertical position between the outer peripheral surface of the shaft portion 111 and the inner peripheral surface of the upper yoke 31. It is supported by an arranged O-ring 153. As a result, the radial bearing 151 is supported at a predetermined position in the first direction D1 while maintaining close contact with the upper yoke 31. The upper part of the shaft portion 111 is exposed above the third yoke 90, and a member necessary for the input operation is coupled.

When a current is applied to the coil 50 from the control circuit 200, a magnetic field as described above is generated, magnetic flux in the vertical direction passes through the magnetic disk 120, and the diameter inside the magnetic disk 120. No magnetic flux is generated along the direction, or even if it is generated, its magnetic flux density is small. A magnetic field line along the radial direction is generated in the second yoke 40, and a magnetic field line in the vertical direction is generated outside the coil 50. At the upper portion of the upper yoke 31 and the third yoke 90, magnetic lines of force are generated in the direction opposite to the magnetic field lines of the second yoke 40 and along the radial direction.

In the ferrofluid 160, the magnetic particles are dispersed in the solvent when no applied magnetic field is generated. Therefore, when an operating member (not shown) connected to the shaft portion 110 is operated, the operating portion 100 rotates relative to the holding portion 20 without receiving a large resistance force.

When a magnetic field is generated, a magnetic field is applied to the ferrofluid 160 along the vertical direction. Due to this magnetic field, the magnetic particles dispersed in the ferrofluid 160 are gathered along the lines of magnetic force, and the magnetic particles arranged in the vertical direction are magnetically connected to each other. In this state, when a force (not shown) for rotating the operating member (not shown) connected to the shaft portion 110 is applied in the direction centered on the central shaft 11, the resistance force (torque) due to the connected magnetic particles acts. Therefore, the operator can feel the resistance as compared with the state where the magnetic field is not generated.

<Second structural example>
FIG. 4 is an exploded perspective view showing a second structural example of the torque generator according to the embodiment of the present invention. In the first structural example shown in FIGS. 1 and 2, a magnetic field is applied to the ferrofluid 160 by one coil 50 as a coil portion, but the number and shape of the coils constituting the coil portion are this. Not limited to. For example, as shown in FIG. 4, two coils 51 and 52 may be laminated along the central axis 11 as the coil portion. As a result, different control can be performed for each coil, and the magnetic field applied to the ferrofluid 160 can be controlled based on the control that was difficult in the case of one coil.

<Torque control>
The torque control in the torque generator according to each embodiment will be described with reference to FIGS. 5 to 9. In each embodiment, the upper limit value at which the magnetic field generated by the coil portion can be generated can be switched by the switching means. The physical property values and settings of each element such as electric resistance shown in FIGS. 5 to 9 are examples, and the present invention is not limited thereto.

<First Embodiment>
FIG. 5 is a functional block diagram of the torque generator of the first embodiment. The torque generator of the first embodiment has, for example, the first structure shown in FIGS. 1 and 2, and includes the circuit shown in FIG. 5 and the like.

As shown in FIG. 5, the coil 50 (resistance value: 10 ohms, N-turn) has two outputs M1 and M2 of the drive circuit D10 (for example, Maxim Integrated's full bridge DC motor driver, MAX14870). Each is connected. The output M1 of one of these is connected to the coil 50 via an electric resistance R11 (resistance value: 50 ohms) as a current limiting element. Both ends of the electric resistance R11 are connected to two output terminals OUT1 and OUT2 of a relay circuit S1 (for example, OMRON MOS FET relay, G3VM-41GR8) as a switching means (switching circuit), respectively. Since the relay circuit S1 can be switched at high speed by using, for example, a semiconductor relay (solid state relay), it is possible to smoothly switch the upper limit value at which the magnetic field can be generated by the coil 50 without making the operator aware of the switching. can.

An end stop signal (FIG. 3) is output to the input terminal (ANODE terminal) of the relay circuit S1 when it is detected that the control circuit 200 is in the end stop state based on the detection result by the rotation angle detecting means 210 (FIG. 3). The output signal A1 (switching signal) is input as (see 3), and the CATHODE terminal is grounded via the electric resistance R12 (resistance value 330 ohms). When the output signal A1 is input to the anode terminal from the control circuit 200 (FIG. 3), the relay circuit S1 switches from the off state to the on state. As a result, the path passing through the current limiting element is switched to the bypass circuit not passing through the current limiting element. When the output signal A1 detects that the detected rotation angle has reached a predetermined predetermined angle in order to give the operator of the operation unit 100 an operation feeling as if it hits a virtual wall and stops. Is output to.

In the drive circuit D10, a pulse width modulation signal (hereinafter, PWM signal) C11 is input to the PWM terminal as a signal from the control circuit 200, and a DIR signal C12 is input to the DIR terminal. Further, the drive circuit D10 is provided with a power supply V1 (voltage 12V). The PWM signal C11 is a signal having a duty ratio corresponding to the torque calculated based on the detection result by the rotation angle detecting means 210 and the setting data stored in the storage unit 201 of the control circuit 200. When the duty ratio of the pulse wave changes in the PWM signal C11, the output current from the drive circuit D10, that is, the current applied to the coil 50 increases or decreases. By controlling the PWM signal C11 by the control circuit 200 in this way, the current applied to the coil 50 is controlled, and the magnetic field generated by the coil 50 changes. As a result, the dispersed state of the magnetic particles in the ferrofluid 160 changes, so that the operator can control the resistance force (torque) that acts when the shaft portion 110 is rotated. The DIR signal C12 output from the control circuit 200 and input to the drive circuit D10 is a control signal that changes the direction of the current applied to the coil 50 in the present embodiment. In the present specification, the DIR signal is omitted in the following description, assuming that the direction of the generated magnetic field is not changed.

Further, when the relay circuit S1 is in the off state, the output from the drive circuit D10 goes to the coil 50 via the electric resistance R11 as a current limiting element, whereas the output from the relay circuit S1 is an end stop signal ( When the output signal A1) is input and turned on, the switching is made toward the coil 50 without passing through the electric resistance R11. Therefore, the electric resistance value in the wiring from the drive circuit D10 to the coil 50 differs depending on whether the relay circuit S1 is in the ON state or the OFF state, and the flowing current value differs. Therefore, it is possible to switch the upper limit value at which the magnetic field generated by the coil 50 can be generated depending on whether or not the operation unit 100 is in the end stop state. In the first embodiment, the electric resistance R11 is used as the current limiting element, but an element other than the electric resistance may be used as long as the current value flowing from the drive circuit D10 to the coil 50 can be switched.

More specifically, first, in the on state where the end stop signal is input, a large resistance force can be given to the rotation of the shaft portion 110 by applying a large current to the coil 50. As a result, when the rotation angle of the shaft portion 110 reaches a predetermined angle, the operator of the operation unit 100 can be given an operation feeling as if it hits a virtual wall and stops.

On the other hand, in the off state, which is not the end stop state, the applied current increases or decreases with respect to the coil 50 in a smaller current range than in the on state. As a result, it is possible to change the dispersed state of the magnetic particles in the magnetic viscous fluid 160 according to the change of the PWM signal within the range where the upper limit value at which the magnetic field can be generated by the coil 50 is small. You will be able to finely control the resistance.

<Second Embodiment>
FIG. 6 is a functional block diagram of the torque generator of the second embodiment. The torque generator of the second embodiment has, for example, the second structure shown in FIG. 4, and includes the circuit shown in FIG. 6 and the like.

As shown in FIG. 6, the coil 51 (resistance value: 60 ohms, N-n) and the coil 52 (resistance value: 12 ohms, N-turn) are connected to the output M1 of the drive circuit D20 in a parallel relationship with each other. .. The other output M2 of the drive circuit D20 is connected to the coil 51 and also to the output terminal OUT2 of the relay circuit S2. A coil 52 is connected to the other output terminal OUT1 of the relay circuit S2.

An output signal A2 (switching signal) is input as an end stop signal (see FIG. 3) to the input terminal (ANODE terminal) of the relay circuit S2, as in the first embodiment shown in FIG. Is grounded via an electrical resistance R2 (resistance value 330 ohms). When the output signal A2 is input to the anode terminal from the control circuit 200 (FIG. 3), the relay circuit S2 switches from the off state to the on state.

In the drive circuit D20, a pulse width modulation signal (hereinafter referred to as PWM signal) C21 is input to the PWM terminal as a signal from the control circuit 200, as in the first embodiment shown in FIG. Further, the drive circuit D20 is provided with a power supply V2 (voltage 12V). The PWM signal C21 is a signal having the same duty ratio as the PWM signal C11 of the first embodiment. When the duty ratio of the pulse wave changes in the PWM signal C21, the output current from the drive circuit D20, that is, the current flowing to the coils 51 and 52 side increases and decreases. By controlling the PWM signal C21 by the control circuit 200 in this way, the current flowing to the coils 51 and 52 is controlled, and the magnetic fields generated by the coils 51 and 52 change. As a result, the dispersed state of the magnetic particles in the ferrofluid 160 changes, so that the operator can control the resistance force (torque) that acts when the shaft portion 110 is rotated.

Further, the output from the drive circuit D20 is given only to the coil 51 and not to the coil 52 when the relay circuit S2 is in the off state, whereas the output is given to the relay circuit S2 as an end stop signal (output). When the signal A2) is input and turned on, the two coils 51 and 52 are switched so as to be given. In other words, a path for energizing a part of the coils 51 and 52 (coil 51) or a path for energizing all of the plurality of coils 51 and 52 can be selected. Therefore, the number of coils to which the current is applied differs depending on whether the relay circuit S2 is in the on state or the off state. Therefore, it is possible to switch the upper limit value of the magnetic field applied to the ferrofluid 160 depending on whether or not the operation unit 100 is in the end-stop state.

More specifically, first, in the on state where the end stop signal is input, by applying a current to both the two coils 51 and 52, a magnetic field due to the coils 51 and 52 is generated at the same time, and the shaft portion 110 It can give a large resistance to rotation. As a result, when the rotation angle of the shaft portion 110 reaches a predetermined angle, the operator of the operation unit 100 can be given an operation feeling as if it hits a virtual wall and stops.

On the other hand, in the off state, which is not the end stop state, a current is applied only to the coil 51, and a smaller magnetic field is generated than in the on state. As a result, it is possible to change the dispersed state of the magnetic particles in the magnetic viscous fluid 160 according to the change of the PWM signal within the range where the upper limit value at which the magnetic field can be generated by the coil 50 is small. You will be able to finely control the resistance.
The other configurations, actions, and effects are the same as those in the first embodiment.

<Third Embodiment>
FIG. 7 is a functional block diagram of the torque generator according to the third embodiment. The torque generator of the third embodiment has, for example, the second structure shown in FIG. 4, and includes the circuit shown in FIG. 7 and the like.

As shown in FIG. 7, the coil 51 (resistance value: 10 ohms, N turns) and the coil 52 (resistance value: 110 ohms, N turns) are connected in order to the output M1 of the drive circuit D30 so as to be in series. Has been done. The other output M2 of the drive circuit D30 is connected to the coil 52 and also to the output terminal OUT1 of the relay circuit S3. The other output terminal OUT2 of the relay circuit S3 is connected to the connection point between the coil 51 and the coil 52.

An output signal A3 (switching signal) is input as an end stop signal (see FIG. 3) to the input terminal (ANODE terminal) of the relay circuit S3, as in the first embodiment shown in FIG. Is grounded via an electrical resistance R3 (330 ohms). When the output signal A3 is input to the anode terminal from the control circuit 200 (FIG. 3), the relay circuit S3 switches from the off state to the on state.

In the drive circuit D30, a pulse width modulation signal (hereinafter referred to as PWM signal) C31 is input to the PWM terminal as a signal from the control circuit 200, as in the first embodiment shown in FIG. Further, the drive circuit D30 is provided with a power supply V3 (voltage 12V). The PWM signal C31 is a signal having the same duty ratio as the PWM signal C11 of the first embodiment. When the duty ratio of the pulse wave changes in the PWM signal C31, the output current from the drive circuit D30, that is, the current flowing to the coils 51 and 52 side increases and decreases. By controlling the PWM signal C31 by the control circuit 200 in this way, the current flowing to the coils 51 and 52 is controlled, and the magnetic fields generated by the coils 51 and 52 change. As a result, the dispersed state of the magnetic particles in the ferrofluid 160 changes, so that the operator can control the resistance force (torque) that acts when the shaft portion 110 is rotated.

Further, the output from the drive circuit D30 is given only to the coil 51 and not to the coil 52 when the end stop signal is input and the relay circuit S3 is in the on state, whereas the output from the relay circuit S2 is in the off state. When it becomes, it switches so that it is given to both of the two coils 51 and 52. In other words, a path for energizing a part of the coils 51 and 52 (coil 51) or a path for energizing all of the plurality of coils 51 and 52 can be selected. Therefore, the resistance of the coil to which the current is applied differs depending on whether the relay circuit S2 is in the ON state or the OFF state, and the upper limit of the current value differs. In the present embodiment, the upper limit of the current value becomes larger when the relay circuit S2 is turned on, and the upper limit of the magnetic field applied to the ferrofluid 160 becomes larger. Therefore, it is possible to switch the upper limit value of the magnetic field applied to the ferrofluid 160 depending on whether or not the operation unit 100 is in the end-stop state.
The other configurations, actions, and effects are the same as those in the second embodiment.

<Fourth Embodiment>
FIG. 8 is a functional block diagram of the torque generator according to the fourth embodiment. The torque generator of the fourth embodiment has, for example, the first structure shown in FIGS. 1 and 2, and includes the circuit shown in FIG. 8 and the like.

As shown in FIG. 8, the coil 50 is connected to the two outputs M1 and M2 of the drive circuit D40. The output from the relay circuit S4 is connected to the power input terminal VIN of the drive circuit D40. A switching element T4 and two power supplies V42 (voltage 2V) and V43 (voltage 12V) are connected to the relay circuit S4.

The switching element T4 is, for example, an NPN type transistor, and an output signal A41 (switching signal) as an end stop signal output from the control circuit 200 is input to the base terminal via the electric resistance R4. When the output signal A41 detects that the detected rotation angle has reached a predetermined predetermined angle in order to give the operator of the operation unit 100 an operation feeling as if it hits a virtual wall and stops. Is output to.

A power supply V41 (voltage 12V) is connected to the collector terminal of the switching element T4, and the emitter terminal is connected to the relay circuit S4. With this configuration, when the output signal A41 is input to the switching element T4, the switching signal A42 (switching signal) is output to the relay circuit S4.

In the relay circuit S4, the off state is switched to the on state by inputting the switching signal A42. In the off state, the low voltage power supply V42 (power supply unit) is connected to the drive circuit D40, and in the on state, the high voltage power supply V43 (power supply unit) is connected to the drive circuit D40. Will be done. That is, one power supply voltage circuit is selected from the two power supply voltage circuits each including the two power supplies V42 and V43 by the switching signal A42 (switching signal).

In the drive circuit D40, a pulse width modulation signal (hereinafter referred to as PWM signal) C41 is input to the PWM terminal as a signal from the control circuit 200, as in the first embodiment shown in FIG. The PWM signal C41 is a signal having the same duty ratio as the PWM signal C11 of the first embodiment, and when the duty ratio of the pulse wave changes in the PWM signal C41, it is applied to the output current from the drive circuit D40, that is, the coil 50. The current that is generated increases or decreases. By controlling the PWM signal C41 by the control circuit 200 in this way, the current applied to the coil 50 is controlled, and the magnetic field generated by the coil 50 changes. As a result, the dispersed state of the magnetic particles in the ferrofluid 160 changes, so that the operator can control the resistance force (torque) that acts when the shaft portion 110 is rotated.

Further, the amplitude of the output from the drive circuit D40 changes according to the power supply connected to the power supply input terminal VIN. That is, when the relay circuit S4 is in the off state and the power supply V42 is connected, a current having a small amplitude is output to the coil 50, and when the relay circuit S4 is in the on state and is connected to the power supply V43. A current having a larger amplitude than that in the off state is output to the coil 50. Therefore, the current applied to the coil 50 increases or decreases depending on whether the relay circuit S4 is in the on state or the off state. Therefore, it is possible to switch the upper limit value of the magnetic field applied to the ferrofluid 160 depending on whether or not the operation unit 100 is in the end-stop state.

More specifically, first, in the on state where the end stop signal is input, a large resistance force can be given to the rotation of the shaft portion 110 by applying a large current having a large amplitude. As a result, when the rotation angle of the shaft portion 110 reaches a predetermined angle, the operator of the operation unit 100 can be given an operation feeling as if it hits a virtual wall and stops.

On the other hand, in the off state, which is not the end-stop state, a small current having a smaller amplitude than in the on state is applied, and a smaller magnetic field is generated than in the on state. As a result, it is possible to change the dispersed state of the magnetic particles in the magnetic viscous fluid 160 according to the change of the PWM signal within the range where the upper limit value at which the magnetic field can be generated by the coil 50 is small. You will be able to finely control the resistance.
The other configurations, actions, and effects are the same as those in the first embodiment.

<Fifth Embodiment>
FIG. 9 is a functional block diagram of the torque generator according to the fifth embodiment. The torque generator of the fifth embodiment has, for example, the second structure shown in FIG. 4, and includes the circuit shown in FIG. 9 and the like. The two coils 51 and 52 in this torque generator have different resistance values from each other, and as shown in FIG. 9, the resistance value of the coil 51 (60 ohms) is larger than the resistance value of the coil 52 (10 ohms). ing.

As shown in FIG. 9, one coil 51 is connected to two outputs M1 and M2 of the first drive circuit D51. A power supply V51 (voltage 12V) is connected to the power supply input terminal VIN of the first drive circuit D51.

The other coil 52 is connected to the two outputs M1 and M2 of the second drive circuit D52. A power supply V52 (voltage 12V) that supplies the same voltage as the power supply V51 is connected to the power supply input terminal VIN of the second drive circuit D52.

In the first drive circuit D51, a PWM signal (pulse width modulation signal) C51 is input to the PWM terminal as a signal from the control circuit 200, as in the first embodiment shown in FIG. The PWM signal C51 is a signal having the same duty ratio as the PWM signal C11 of the first embodiment, and when the duty ratio of the pulse wave changes in the PWM signal C51, the output current from the first drive circuit D51, that is, the coil. The current applied to 51 increases or decreases. By controlling the PWM signal C51 by the control circuit 200 in this way, the current applied to the coil 51 is controlled, and the magnetic field generated by the coil 51 changes.

Similarly to the first drive circuit D51, a PWM signal (pulse width modulation signal) C61 is input to the PWM terminal as a signal from the control circuit 200 in the second drive circuit D52. As a result, the control circuit 200 controls the PWM signal C61 to control the current applied to the coil 52, and the magnetic field generated by the coil 52 changes. Since the coil 52 has a smaller resistance value than the coil 51, a larger current flows.

The control circuit 200 detects whether or not it is in the end stop state based on the detection result of the rotation angle detecting means 210, and based on the detection result, the pulse width is set in one of the two drive circuits D51 and D52 as the switching means. Switch to give a modulated signal. That is, when it is not in the end-stop state, the PWM signal C51 is given to the first drive circuit D51, and when it is in the end-stop state, the PWM signal C61 is given to the second drive circuit D52. Since the resistance values of the coils 51 and 52 are different from each other, it is possible to switch the upper limit value at which the magnetic field generated by the coil can be generated by switching based on the end stop state.

More specifically, first, in the on state in which the end stop signal is input, a large resistance force can be given to the rotation of the shaft portion 110 by applying a current to the coil 52. As a result, when the rotation angle of the shaft portion 110 reaches a predetermined angle, the operator of the operation unit 100 can be given an operation feeling as if it hits a virtual wall and stops.

On the other hand, in the off state, which is not the end stop state, a smaller current is applied to the coil 51 than in the on state. As a result, it is possible to change the dispersed state of the magnetic particles in the magnetic viscous fluid 160 according to the change of the PWM signal within the range where the upper limit value at which the magnetic field can be generated by the coil 50 is small. You will be able to finely control the resistance.
The other configurations, actions, and effects are the same as those in the first embodiment.
Although the present invention has been described with reference to the above-described embodiment, the present invention is not limited to the above-described embodiment, and can be improved or modified within the purpose of improvement or the idea of the present invention.

As described above, the torque generator according to the present invention is useful in that fine torque control corresponding to the magnitude of torque is possible.

10 Torque generator 11 Central shaft 20 Holding part 31 Upper yoke 32 Outer yoke 33 Lower yoke 40 Second yoke 41 Upper surface 42 Hole 43 Lower surface 50, 51, 52 Coil (magnetic field generator)
60 Sealing member 65 First annular member 70 Second annular member 80 Gap 90 Third yoke 100 Operation part 110 Shaft part (operation shaft)
111 Shaft (operation shaft)
112 Flange 113 Tip 120 Magnetic disk 121 Central hole 140 Support member 141 Holder 151 Radial bearing 152 Pusher 153 O-ring 160 Ferrofluid 200 Control circuit 201 Storage 202 Torque calculation unit 210 Rotation angle detection means A1, A2, A3, A41 output signal (switching signal)
A42 switching signal (switching signal)
C11, C21, C31, C41, C51, C61 Pulse width modulation signal (PWM signal)
D1 1st direction D2 2nd direction D10, D20, D30, D40, D51, D52 Drive circuit R11 Electrical resistance (current limiting element)
S1, S2, S3, S4 relay circuit

Claims (6)

A ferrofluid whose viscosity changes according to the applied magnetic field,
A coil portion that generates a magnetic field applied to the ferrofluid when energized,
An operation unit whose torque changes depending on the viscosity of the ferrofluid,
A control unit that controls energization of the coil unit and
A switching means for switching the upper limit value at which a magnetic field can be generated by the coil portion is provided .
A housing in which the coil portion is fixedly arranged and
A shaft portion as the operation portion, which is pivotally supported by the housing so as to be rotatable,
A movable member fixed to the shaft portion and integrally rotatably provided,
A rotation angle detecting means for detecting the rotation of the shaft portion is provided.
The control unit
A storage unit that stores setting data that changes the torque applied to the shaft unit according to the rotation angle of the shaft unit.
It has a detection result by the rotation angle detecting means and a torque calculation unit that calculates a torque applied to the shaft portion based on the setting data.
A torque generator characterized in that the switching means is controlled and the current value for energizing the coil portion is controlled according to the magnitude of the torque applied to the shaft portion calculated by the torque calculation unit. A ferrofluid whose viscosity changes according to the applied magnetic field,
A coil portion that generates a magnetic field applied to the ferrofluid when energized,
An operation unit whose torque changes depending on the viscosity of the ferrofluid,
A control unit that controls energization of the coil unit and
A switching means for switching the upper limit value at which a magnetic field can be generated by the coil portion is provided.
The switching means includes a switching circuit for switching an upper limit value at which a magnetic field can be generated by the coil portion by switching the current range for energizing the coil portion.
The torque generating device is characterized in that the switching circuit is controlled by a switching signal from the control unit. The switching means includes a current limiting element connected in series with the coil portion.
The second aspect of the present invention, wherein the switching circuit is controlled by a switching signal from the control unit to select either a path passing through the current limiting element or a circuit not passing through the current limiting element. Torque generator. A ferrofluid whose viscosity changes according to the applied magnetic field,
A coil portion that generates a magnetic field applied to the ferrofluid when energized,
An operation unit whose torque changes depending on the viscosity of the ferrofluid,
A control unit that controls energization of the coil unit and
A switching means for switching the upper limit value at which a magnetic field can be generated by the coil portion is provided.
The coil part is composed of a plurality of coils.
The switching means energizes a part of the plurality of coils by a switching signal from the control unit, or a path that energizes another part of the plurality of coils or all of the plurality of coils. A torque generator characterized in that it is controlled to select one of the two. A ferrofluid whose viscosity changes according to the applied magnetic field,
A coil portion that generates a magnetic field applied to the ferrofluid when energized,
An operation unit whose torque changes depending on the viscosity of the ferrofluid,
A control unit that controls energization of the coil unit and
A switching means for switching the upper limit value at which a magnetic field can be generated by the coil portion is provided.
The switching means includes a drive circuit connected to the coil unit and a plurality of different power supply voltage circuits, and the plurality of switching means are provided as a power supply unit that supplies power to the drive circuit by a switching signal from the control unit. A torque generator characterized in that it is controlled to select one power supply voltage circuit from the power supply voltage circuits of the above. A housing in which the coil portion is fixedly arranged and
A shaft portion as the operation portion, which is pivotally supported by the housing so as to be rotatable,
A movable member fixed to the shaft portion and integrally rotatably provided,
A rotation angle detecting means for detecting the rotation of the shaft portion is provided.
The control unit
A storage unit that stores setting data that changes the torque applied to the shaft unit according to the rotation angle of the shaft unit.
It has a detection result by the rotation angle detecting means and a torque calculation unit that calculates a torque applied to the shaft portion based on the setting data.
2. The torque generator described.

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