Load Control Unit

Abstract

To apply a load to a degree that does not cause discomfort to a user even when the user performs an operation quickly. [Solution] In the load control unit (1), a target value of the braking force that the control unit (15) applies to the magnetorheological fluid device (14) in relation to the amount of cable (12) unwound from the reel (11) is predetermined, and if the number of rotations per unit time of the rotating shaft member (11a) when the cable (12) is unwound from the reel (11) is equal to or greater than a predetermined threshold, the target value is set to a value that corresponds to an amount of unwound that is greater than the actual amount of unwound.

Description

[Technical Field]

[0001] The present invention relates to a load control unit. [Background technology]

[0002] Patent Document 1 discloses an MR (Magneto Rheological) fluid loading mechanism that applies a braking force to the rotation of a moving part by using an MR fluid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-110448 Summary of the Invention [Problem to be solved by the invention]

[0004] In a load control unit that uses a magnetorheological fluid to apply a braking force to the rotation of a rotating shaft member, a braking force is applied when the rotating shaft member is rotating in the forward direction, and the application of the braking force is stopped when the rotating shaft member is completely stopped, i.e., when the number of rotations per unit time of the rotating shaft member is zero.When the rotating shaft member is rotating slowly in the forward direction, the number of rotations per unit time of the rotating shaft member repeatedly goes between being slightly above zero and being zero, causing the load control unit to alternate between applying a braking force and not applying a braking force, which can result in small vibrations.

[0005] The present disclosure aims to provide a load control unit that can apply a load that does not cause discomfort to the user even when the user performs an operation quickly. [Means for solving the problem]

[0006] In order to solve the above problem, a load control unit according to one embodiment of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid, a reel that rotates around the rotating shaft member, a cable that is unwound from the reel in accordance with the rotation of the rotating shaft member, a control unit that controls the magnetorheological fluid device, and a measurement unit that measures the rotational speed of the rotating shaft member, wherein a target value of the braking force that the control unit causes the magnetorheological fluid device to apply is predetermined for the amount of cable that is unwound from the reel, and when the number of rotations per unit time of the rotating shaft member when the cable is unwound from the reel is equal to or greater than a predetermined threshold, the control unit sets the target value to a value that corresponds to an amount of unwound that is greater than the actual amount of unwound.

[0007] In order to solve the above problem, a load control unit according to one embodiment of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid, a reel that rotates around the rotating shaft member, a cable that is reeled out from the reel in accordance with the rotation of the rotating shaft member, a control unit that controls the magnetorheological fluid device, and a measurement unit that measures the speed at which the cable is reeled out, and a target value of the braking force that the control unit applies to the magnetorheological fluid device is predetermined for the amount of cable that is reeled out from the reel, and when the speed at which the cable is reeled out from the reel is equal to or greater than a predetermined threshold, the control unit sets the target value of the braking force to a value that corresponds to an amount of cable that is greater than the actual amount of cable that is reeled out. [Effects of the Invention]

[0008] According to one aspect of the present invention, even when a user performs an operation quickly, it is possible to apply a load to the extent that the user does not feel uncomfortable. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a general configuration of a load generating device to which a load control unit according to an embodiment of the present invention is retrofitted; [Figure 2] FIG. 2 is a cross-sectional view of the load control unit as seen from the left side in the left-right direction. [Figure 3] 3A and 3B are diagrams illustrating the control of the magnetorheological fluid device by the control device. [Figure 4] 10 is a diagram used to explain control when the payout speed of the second cable is high. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Fig. 1 is a schematic diagram showing the general configuration of a load generating device to which a load control unit according to one embodiment of the present invention is retrofitted. Fig. 1 shows a training device 100 as an example of a load generating device. The training device 100 is used for exercise or rehabilitation aimed at strengthening muscles. Hereinafter, the up-down direction, left-right direction, and front-back direction will be defined as shown in Fig. 1.

[0011] The training device 100 employs a weight stack system and includes a frame 101, a first cable 102, a pulley group 103, a weight stack 104, a lift shaft 105-1, a left guide shaft 105-2, and a right guide shaft 105-3.

[0012] The frame 101 is a skeleton that supports the weight stack 104. The frame 101 shown in FIG. 1 includes a right frame 101-1, an upper frame 101-2, a left frame 101-3, and a lower frame 101-4. The right frame 101-1 and the left frame 101-3 are pillars that extend in the vertical direction. The upper frame 101-2 connects the upper end of the right frame 101-1 to the upper end of the left frame 101-3. The lower frame 101-4 connects the lower end of the right frame 101-1 to the lower end of the left frame 101-3.

[0013] One end 102a of first cable 102 is located outside frame 101 of training device 100. A user of training device 100 (hereinafter simply referred to as the user) connects an attachment to one end 102a of first cable 102 according to the training to be performed. The other end 102b of first cable 102 is fixed to upper frame 101-2. For example, by connecting a handle to be held by the user to one end 102a of first cable 102, training device 100 functions as an adjustable pulley.

[0014] The pulley group 103 is arranged to smooth the movement of the first cable 102, and each pulley has a rotatable structure. The pulley group 103 shown in Fig. 1 includes a pulley 103-1, a pulley 103-2, a pulley 103-3, and a pulley 103-4. The pulley 103-4 is hung on the first cable 102 and is connected to the tip of the lift shaft 105-1.

[0015] In the weight stack 104, multiple weight plates are aligned vertically along the left guide shaft 105-2 and the right guide shaft 105-3. The weight stack 104 is provided so that the load applied to the first cable 102 can be adjusted for each weight plate. In FIG. 1, a weight pin P is inserted into one of the multiple weight plates.

[0016] Lift shaft 105-1 is integrated with a weight plate into which a weight pin P is inserted. When a user performs training by pulling a handle connected to one end 102a of first cable 102, a load corresponding to the total weight of the weight plate integrated with lift shaft 105-1 and a weight plate disposed above the weight plate integrated with lift shaft 105-1 is applied upward to one end 102a of first cable 102. Hereinafter, the weight plate integrated with lift shaft 105-1 by weight pin P will be referred to as the first weight.

[0017] When the user pulls down the handle against the load, first cable 102 is reeled out to the outside of training apparatus 100. Because the other end 102b of first cable 102 is fixed to upper frame 101-2, when first cable 102 is reeled out to the outside of training apparatus 100, pulley 103-4, lift shaft 105-1 connected to pulley 103-4, the first weight, and the weight plate located above the first weight are lifted upward.

[0018] The pulley 103-4 is not essential to the training apparatus 100. Providing the pulley 103-4 in the training apparatus 100 provides the following effect. The pulley 103-4 is a movable pulley, and has the effect of increasing the stroke of the user pulling a handle or the like connected to one end 102a of the first cable 102. When the pulley 103-4 is provided, the stroke is doubled compared to when the pulley 103-4 is not provided. Providing the pulley 103-4 in the training apparatus 100 increases the stroke, thereby providing the effect of enabling more effective training. When the pulley 103-4 is not used, the tip of the lift shaft 105-1 is connected to the other end 102b of the first cable 102, which is fixed to the upper frame 101-2 in FIG. 1.

[0019] A load control unit 1 is installed as an add-on directly below the weight stack 104 of the training device 100. FIG. 2 is a cross-sectional view of the load control unit 1 as viewed from the left side in the left-right direction. As shown in FIG. 2, the load control unit 1 includes a reel 11, a second cable 12, a rotation detection unit 13, a magnetorheological fluid device 14, and a laser distance measuring device 19 inside a unit case 17. The load control unit 1 also includes a control device 15 housed inside a protective case 18. The control device 15 is an example of a control unit.

[0020] The reel 11 has a rotary shaft member 11a and rotates around the rotary shaft member 11a. A second cable 12 is wound around the reel 11. The tip 12a of the second cable 12 is connected to a joint 12b. The second cable 12 is connected to the lower end of the lift shaft 105-1 via the joint 12b.

[0021] The rotation detector 13 detects the amount and direction of rotation of the rotating shaft member 11a. The rotation detector 13 is, for example, a rotary encoder, a magnetic sensor, or the like. When the lift shaft 105-1 rises, the rotating shaft member 11a rotates in the normal direction, and the second cable 12 is unwound from the reel 11. At this time, the rotation detector 13 transmits to the control device 15 a detection signal including information indicating that the rotating shaft member 11a has rotated in the normal direction and information indicating the amount of rotation. The normal direction is an example of the second direction.

[0022] The rotating shaft member 11a is biased in a reverse direction opposite to the normal rotation direction by a biasing member such as a spiral spring. For example, when the magnetorheological fluid device 14 is not applying a braking force, the second cable 12 is wound onto the reel 11 by the biasing force of the biasing member. The reverse direction is an example of the first direction.

[0023] The magnetorheological fluid device 14 has a magnetorheological fluid 14a and a container 14b that stores the magnetorheological fluid 14a. The magnetorheological fluid 14a has a property that its viscosity changes depending on the strength of a magnetic field. The container 14b has an opening 14c on its side that faces the reel 11 in the front-to-rear direction. A portion 11b of the rotating shaft member 11a is inserted into the container 14b through the opening 14c.

[0024] The control device 15 is, for example, a semiconductor substrate equipped with a microcontroller (MCU), and controls the magnetorheological fluid device 14. Under the control of the control device 15, the magnetorheological fluid device 14 applies a magnetic field to the magnetorheological fluid, thereby changing the viscosity of the magnetorheological fluid and applying a braking force to the rotating shaft member 11a. Specifically, the magnetorheological fluid device 14 has a rotor to which the rotating shaft member 11a is fixed and a coil that applies a magnetic field to the rotor. A magnetic field is generated in response to an electrical signal input to the coil of the magnetorheological fluid device 14. This magnetic field changes the viscosity of the magnetorheological fluid. The change in viscosity of the magnetorheological fluid applies a braking force that inhibits rotation of the rotor, i.e., the rotating shaft member 11a. The electrical signal input to the coil is, for example, a DC signal with a current value corresponding to the magnetic field generated by the magnetorheological fluid device 14. The electrical signal input to the coil of the magnetorheological fluid device 14 may be a pulse signal, and the generated magnetic field may be changed by changing the pulse width relative to the pulse period. When a pulse signal is input, the braking force can be controlled by controlling the duty ratio, based on the change in the magnitude of the magnetic field that accompanies a change in the effective current caused by the electrical signal.

[0025] When the lift shaft 105-1 is lifted upward, the second cable 12 connected to the lower end of the lift shaft 105-1 via the joint 12b is unwound from the reel 11. At this time, the load control unit 1 applies an additional load to the training load provided by the weight stack 104 by causing the magnetorheological fluid device 14 to apply a braking force to the rotating shaft member 11a of the reel 11.

[0026] The laser range finder 19 measures the distance to the first weight among the multiple weight plates included in the weight stack 104. The laser range finder 19 is housed on the upper surface side of the unit case 17, and the laser light emitting surface and light receiving surface are exposed to the outside of the unit case 17.

[0027] 2 shows the weight plates that make up the weight stack 104, including the bottom weight plate 104-1, the second-lowest weight plate 104-2, and the third-lowest weight plate 104-3. The weight plates that make up the weight stack 104 each have a pin insertion hole into which a weight pin P can be inserted. For example, weight plate 104-1 has a pin insertion hole 104-1h, and weight plate 104-2 has a pin insertion hole 104-2h. In FIG. 2, the weight pin P is inserted into the pin insertion hole 104-2h of weight plate 104-2, and weight plate 104-2 is the first weight.

[0028] The lift shaft 105-1 has pin insertion holes 105-1h that correspond to the pin insertion holes 104-2h of the weight plates 104-2 that make up the weight stack 104. The weight pins P are inserted from the front openings of the pin insertion holes 104-2h of the weight plate 104-2, pass through the pin insertion holes 105-1h at the positions corresponding to the weight plate 104-2, and reach the rear sides of the pin insertion holes 104-2h. This allows the weight plate 104-2 to become one with the lift shaft 105-1.

[0029] Fig. 3 is a diagram illustrating the control of the magnetorheological fluid device 14 by the control device 15. Fig. 3 shows the relationship of the control of the magnetorheological fluid device 14 by the control device 15 with respect to the number of rotations per unit time of the rotating shaft member 11a. In other words, Fig. 3 shows the relationship of the control of the magnetorheological fluid device 14 by the control device 15 with respect to the speed at which the second cable 12 is paid out from or wound onto the reel 11.

[0030] The rotation detector 13 and the controller 15 are examples of a measuring unit. Based on the amount and direction of rotation of the rotating shaft member 11a obtained from the rotation detector 13, the controller 15 obtains one or more of the speed at which the second cable 12 is paid out from the reel 11, the speed at which the second cable 12 is wound onto the reel 11, and the number of rotations per unit time of the rotating shaft member 11a.

[0031] When the rotating shaft member 11a of the reel 11 is rotating in the reverse direction and the number of rotations per unit time of the rotating shaft member 11a is equal to or greater than the first threshold value Vth1, the control device 15 does not cause the magnetorheological fluid device 14 to apply a magnetic field to the magnetorheological fluid 14a and does not apply a braking force to the rotating shaft member 11a. In other words, when the rotating shaft member 11a of the reel 11 is rotating in the reverse direction and the number of rotations per unit time of the rotating shaft member 11a is equal to or greater than the first threshold value Vth1, the control device 15 does not cause the magnetorheological fluid device 14 to input an electric signal to the coil and does not apply a braking force to the rotating shaft member 11a.

[0032] When the rotating shaft member 11a of the reel 11 is rotating in the reverse direction and the number of rotations per unit time of the rotating shaft member 11a is less than the first threshold value Vth1, the control device 15 causes the magnetorheological fluid device 14 to apply a magnetic field to the magnetorheological fluid 14a and apply a braking force to the rotating shaft member 11a. In other words, when the rotating shaft member 11a of the reel 11 is rotating in the reverse direction and the number of rotations per unit time of the rotating shaft member 11a is less than the first threshold value Vth1, the control device 15 causes the coil to input an electric signal and apply a braking force to the rotating shaft member 11a.

[0033] When the rotating shaft member 11a of the reel 11 is rotating in the forward direction, the control device 15 controls the magnetorheological fluid device 14 to apply a magnetic field to the magnetorheological fluid 14a and apply a braking force to the rotating shaft member 11a. In other words, when the rotating shaft member 11a of the reel 11 is rotating in the forward direction, the control device 15 inputs an electric signal to the coil and applies a braking force to the rotating shaft member 11a.

[0034] While the magnetorheological fluid device 14 applies a braking force sufficient to prevent the second cable 12 from being wound onto the reel 11, the second cable 12 is not wound onto the reel 11. To prepare for the user's next training motion, it is desirable to control the magnetorheological fluid device 14 to stop applying the braking force when the rotating shaft member 11a completely stops, i.e., when the number of rotations per unit time of the rotating shaft member 11a becomes zero. However, such control can cause discomfort to the user. For example, during training or rehabilitation, the user may slowly pull the first cable 102. In this case, the number of rotations per unit time of the rotating shaft member 11a during forward rotation does not always exceed zero, but actually alternates between being slightly above zero and being zero. In other words, the state in which the braking force is applied and the state in which the braking force is not applied alternately, which may cause discomfort to the user. Furthermore, the alternating state in which the braking force is applied and the state in which the braking force is not applied may cause minute vibrations in the load control unit 1. This vibration may also cause discomfort to the user.

[0035] 3, the control device 15 performs control to stop the application of braking force by the magnetorheological fluid device 14 when the rotation speed per unit time of the rotating shaft member 11a during reverse rotation becomes equal to or greater than the first threshold value Vth1, so that even if the rotation speed per unit time of the rotating shaft member 11a during forward rotation alternates between being slightly above 0 and being 0, braking force is always applied by the magnetorheological fluid device 14. As a result, even if the user slowly pulls the first cable 102, there is no intermittent switching between a state in which braking force is applied and a state in which braking force is not applied.

[0036] Control when the payout speed of the second cable 12 is high will be described using Figure 4. Figure 4 is a diagram used to explain control when the payout speed of the second cable 12 is high. The load control unit 1 changes the braking force applied to the rotating shaft member 11a depending on the amount of second cable 12 paid out from the reel 11. In Figure 4, the broken line shows a program waveform used by the control device 15 when controlling the magnetorheological fluid device 14. Program waveform 30 shows a target value of the braking force that the control device 15 applies to the magnetorheological fluid device 14 in relation to the amount of payout of the second cable 12.

[0037] In the magnetorheological fluid device 14, a predetermined delay occurs between the time when an electrical signal is input to the coil and the time when a braking force is actually applied. The predetermined delay is, for example, 0.5 seconds. If the user pulls the first cable 102 quickly and the number of rotations per unit time (rotational speed) when the rotating shaft member 11a rotates in the forward direction exceeds the second threshold, the stroke may end during the delay of the magnetorheological fluid device 14. For example, in a training tool 100 capable of pulling the first cable 102 by 2.2 m, if a braking force is applied when the first cable 102 is pulled by 1.5 m or more, and the first cable 102 is pulled over a 0.7 m range (1.5 m to 2.2 m) in 0.5 seconds or less, the stroke may end during the delay of the magnetorheological fluid device 14. In this case, the second threshold is the rotational speed of the rotating shaft member 11a when the first cable 102 is pulled at a speed of 1.4 m / s.

[0038] For example, when the control device 15 controls the magnetorheological fluid device 14 based on the program waveform 30, if the number of rotations per unit time of the rotating shaft member 11a rotating in the forward direction exceeds the second threshold, there is a risk that the braking force may not be applied satisfactorily, as shown in the actual waveform 40. Therefore, when the number of rotations per unit time when the rotating shaft member 11a is rotating in the forward direction exceeds the second threshold, the control device 15 sets the target value of the braking force to a value that corresponds to a larger amount of extension than the actual amount of extension in the program waveform 30, as shown in the program waveform 31. By advancing the setting in this way, the braking force applied is increased, as shown in the actual waveform 41, and the user does not feel uncomfortable.

[0039] [Modification] In the above embodiment, the control device 15 controls the magnetorheological fluid device 14 based on the number of rotations per unit time of the rotating shaft member 11a to determine whether to apply a braking force to the rotating shaft member 11a. However, the parameter used by the control device 15 to determine whether to apply a braking force to the rotating shaft member 11a does not have to be the number of rotations per unit time of the rotating shaft member 11a. For example, when the second cable 12 is being wound around the reel 11 at a speed equal to or faster than the first set speed, the magnetorheological fluid device 14 may not apply a magnetic field to the magnetorheological fluid 14a, and when the second cable 12 is being wound around the reel 11 at the first set speed or when the second cable 12 is being unwound from the reel 11, the magnetorheological fluid device 14 may apply a magnetic field to the magnetorheological fluid 14a.

[0040] In the above embodiment, when the number of rotations per unit time when the rotating shaft member 11a rotates in the forward direction is equal to or greater than the second threshold value, the control device 15 sets the target value of the braking force to a value associated with a payout amount greater than the actual payout amount in the program waveform 30, as in the program waveform 31. However, the parameter used by the control device 15 to determine whether to set the target value of the braking force to a value associated with a payout amount greater than the actual payout amount does not have to be the rotational speed of the rotating shaft member 11a when rotating in the forward direction. For example, when the payout speed at which the second cable 12 is paid out from the reel 11 is equal to or greater than the second set speed, the control device 15 may set the target value of the braking force to a value associated with a payout amount greater than the actual payout amount.

[0041] In the above embodiment, the control device 15 does not cause the magnetorheological fluid device 14 to apply a magnetic field to the magnetorheological fluid 14a when the number of rotations per unit time when the rotating shaft member 11a is rotating in the reverse direction is equal to or greater than the first threshold value. However, as long as it does not interfere with winding of the second cable 12 onto the reel 11, the control device 15 may cause the magnetorheological fluid device 14 to continue applying a magnetic field to the magnetorheological fluid 14a even when the number of rotations per unit time when the rotating shaft member 11a is rotating in the reverse direction is equal to or greater than the first threshold value. For example, the control device 15 may cause the magnetorheological fluid device 14 to apply a predetermined magnetic field to the magnetorheological fluid 14a when the number of rotations per unit time of the rotating shaft member 11a when rotating in the reverse direction is equal to or greater than a first threshold value, and may cause the magnetorheological fluid device 14 to apply a magnetic field greater than the predetermined magnetic field to the magnetorheological fluid 14a when the rotating shaft member 11a when rotating in the reverse direction is equal to or greater than the first threshold value Vth1 or when the rotating shaft member 11a when rotating in the forward direction. In other words, the control device 15 may cause the magnetorheological fluid device 14 to input a predetermined electric signal when the number of rotations per unit time of the rotating shaft member 11a when rotating in the reverse direction is equal to or greater than the first threshold value, and may cause the magnetorheological fluid device 14 to input an electric signal greater than the predetermined electric signal when the rotating shaft member 11a when rotating in the reverse direction is equal to or greater than the first threshold value Vth1 or when the rotating shaft member 11a when rotating in the forward direction. Here, the predetermined magnetic field has a strength that does not interfere with winding of the second cable 12 onto the reel 11. The predetermined electrical signal has a strength that does not interfere with winding of the second cable 12 onto the reel 11.

[0042] In the above embodiment, the rotating shaft member 11a of the reel 11 is biased in the reverse direction opposite to the normal rotation direction by a biasing member such as a power spring. The method of biasing the rotating shaft member 11a of the reel 11 does not have to use a biasing member such as a power spring, and the rotating shaft member 11a may be biased using an electric motor under the control of the control device 15.

[0043] 〔summary〕 A load control unit according to a first aspect of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a measurement unit that measures the rotational speed of the rotating shaft member, a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid, and a control unit that controls the magnetorheological fluid device, wherein the control unit does not cause the magnetorheological fluid device to apply a magnetic field to the magnetorheological fluid when the number of rotations per unit time when the rotating shaft member is rotating in a first direction is equal to or greater than a first threshold value, and causes the magnetorheological fluid device to apply a magnetic field to the magnetorheological fluid when the number of rotations per unit time when the rotating shaft member is rotating in the first direction is less than the first threshold value or when the rotating shaft member is rotating in a second direction opposite to the first direction.

[0044] According to the above configuration, vibration can be suppressed in the load control unit that applies a braking force to the rotation of the rotating shaft member by utilizing a magnetorheological fluid.

[0045] A load control unit according to a second aspect of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a measurement unit that measures the rotational speed of the rotating shaft member, a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid in accordance with an input electrical signal, and a control unit that controls the magnetorheological fluid device, wherein the control unit does not input the electrical signal to the magnetorheological fluid device when the number of rotations per unit time when the rotating shaft member is rotating in a first direction is equal to or greater than a first threshold value, and inputs the electrical signal to the magnetorheological fluid device when the number of rotations per unit time when the rotating shaft member is rotating in the first direction is less than the first threshold value or when the rotating shaft member is rotating in a second direction opposite to the first direction.

[0046] The above configuration also makes it possible to suppress vibrations in the load control unit that applies a braking force to the rotation of the rotating shaft member by utilizing a magnetorheological fluid.

[0047] A load control unit according to a third aspect of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid, a control unit that controls the magnetorheological fluid device, a reel that rotates around the rotating shaft member, a cable that is unwound from or wound onto the reel in accordance with the rotation of the rotating shaft member, and a measurement unit that measures the speed at which the cable is wound, and the control unit does not cause the magnetorheological fluid device to apply a magnetic field to the magnetorheological fluid when the cable is wound onto the reel at a speed greater than or equal to a first set speed, and causes the magnetorheological fluid device to apply a magnetic field to the magnetorheological fluid when the cable is wound onto the reel at a speed less than the first set speed or when the cable is unwound from the reel.

[0048] The above configuration also makes it possible to suppress vibrations in the load control unit that applies a braking force to the rotation of the rotating shaft member by utilizing a magnetorheological fluid.

[0049] A load control unit according to a fourth aspect of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a measurement unit that measures the rotational speed of the rotating shaft member, a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid, and a control unit that controls the magnetorheological fluid device, wherein the control unit causes the magnetorheological fluid device to apply a predetermined magnetic field to the magnetorheological fluid when the number of rotations per unit time of the rotating shaft member when rotating in a first direction is equal to or greater than a first threshold value, and causes the magnetorheological fluid device to apply a magnetic field greater than the predetermined magnetic field to the magnetorheological fluid when the number of rotations per unit time of the rotating shaft member when rotating in the first direction is less than the first threshold value or when the rotating shaft member is rotating in a second direction opposite to the first direction.

[0050] The above configuration also makes it possible to suppress vibrations in the load control unit that applies a braking force to the rotation of the rotating shaft member by utilizing a magnetorheological fluid.

[0051] A load control unit according to a fifth aspect of the present invention is a load control unit that applies a desired braking force to the rotation of a rotating shaft member, and includes a measurement unit that measures the rotational speed of the rotating shaft member, a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid in accordance with an input electrical signal, and a control unit that controls the magnetorheological fluid device, wherein the control unit inputs a predetermined electrical signal to the magnetorheological fluid device when the number of rotations per unit time when the rotating shaft member is rotating in a first direction is equal to or greater than a first threshold value, and inputs an electrical signal greater than the predetermined electrical signal to the magnetorheological fluid device when the number of rotations per unit time of the rotating shaft member when the rotating shaft member is rotating in the first direction is less than the first threshold value, or when the rotating shaft member is rotating in a second direction opposite to the first direction.

[0052] The above configuration also makes it possible to suppress vibrations in the load control unit that applies a braking force to the rotation of the rotating shaft member by utilizing a magnetorheological fluid.

[0053] The load control unit of aspect 6 of the present invention is any one of aspects 1, 2, 4 and 5 above, and comprises a reel having the rotating shaft member and rotating around the rotating shaft member, and a cable that is unwound from the reel when the rotating shaft member rotates in the second direction, and the control unit changes the magnitude of the braking force depending on the amount of cable unwound from the reel.

[0054] Depending on the type of training, the training effect may be increased by applying a strong load at the beginning or end of pulling the first cable 102. With the above configuration, the braking force can be adjusted by changing the magnitude of the braking force according to the amount of cable payout, such as by applying a strong braking force at the beginning or end of pulling.

[0055] In the load control unit of aspect 7 of the present invention, in aspect 6 above, a target value of the braking force that the control unit applies to the magnetorheological fluid device is predetermined for the payout amount, and when the number of rotations per unit time of the rotating shaft member when rotating in the second direction is equal to or greater than a second threshold value, the control unit sets the target value of the braking force to a value corresponding to a payout amount that is greater than the actual payout amount.

[0056] According to the above configuration, even when the user operates first cable 102 quickly, it is possible to apply a load to the extent that the user does not feel uncomfortable.

[0057] In the load control unit of aspect 8 of the present invention, in aspect 3 above, a target value of the braking force that the control unit applies to the magnetorheological fluid device is predetermined in relation to the amount of cable that is unwound from the reel, and when the speed at which the cable is unwound from the reel is equal to or greater than a second set speed, the control unit sets the target value of the braking force to a value that corresponds to an amount of cable that is greater than the actual amount of cable that is unwound.

[0058] According to the above configuration, even when the user operates first cable 102 quickly, it is possible to apply a load to the extent that the user does not feel uncomfortable.

[0059] A load control unit according to aspect 9 of the present invention is the same as aspect 6 above, in that the rotating shaft member of the reel is biased in the first direction, and the cable is wound onto the reel when the magnetorheological fluid device is not applying a braking force to the rotating shaft member.

[0060] According to the above configuration, second cable 12 is wound around reel 11, allowing the user to repeat the movements for training or rehabilitation multiple times.

[0061] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0062] 1 Load Control Unit 11 reels 11a Rotating shaft member 12 Second Cable 13 Rotation detection unit 14 Magnetorheological fluid device 14a Magnetorheological fluid 15 Control device 30, 31 Program waveform 40, 41 Actual waveform 100 Training Equipment 102 First Cable Vth1 First threshold

Claims

1. A load control unit that applies a desired braking force to the rotation of a rotating shaft member, a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid; a reel that rotates around the rotary shaft member; a cable that is unwound from the reel in response to rotation of the rotary shaft member; a control unit for controlling the magnetorheological fluid device; a measuring unit that measures the rotation speed of the rotating shaft member, a target value of the braking force that the control unit applies to the magnetorheological fluid device is set in advance with respect to the amount of the cable that is paid out from the reel, The control unit is a load control unit that sets the target value to a value corresponding to a payout amount that is greater than the actual payout amount when the number of rotations per unit time of the rotating shaft member when the cable is being paid out from the reel is equal to or greater than a predetermined threshold value.

2. A load control unit that applies a desired braking force to the rotation of a rotating shaft member, a magnetorheological fluid device that applies the braking force to the rotating shaft member by applying a magnetic field to a magnetorheological fluid; a reel that rotates around the rotary shaft member; a cable that is unwound from the reel in response to rotation of the rotary shaft member; a control unit for controlling the magnetorheological fluid device; a measuring unit for measuring the speed at which the cable is paid out, a target value of the braking force that the control unit applies to the magnetorheological fluid device is set in advance with respect to the amount of the cable that is paid out from the reel, The control unit is a load control unit that sets the target value of the braking force to a value associated with a payout amount that is greater than the actual payout amount when the speed at which the cable is paid out from the reel is greater than a predetermined threshold value.

3. When the rotary shaft member rotates in a first direction, the cable is unwound from the reel, The rotary shaft member of the reel is biased in a second direction opposite to the first direction, 3. The load control unit according to claim 1, wherein the cable is wound around the reel when the magnetorheological fluid device is not applying a braking force to the rotating shaft member.

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