Method for producing magnetic viscosity fluid device

Abstract

To provide a method for producing a magnetic viscosity fluid device in which a variation (tolerance) of a rate (magnetic particle content) of magnetic particles in a magnetic viscosity fluid filled in the magnetic viscosity fluid device can be decreased.SOLUTION: A method for producing a magnetic viscosity fluid device is configured to interpose a magnetic viscosity fluid between members and transmit a force corresponding to the magnetic intensity applied to the magnetic viscosity fluid between the members. The method includes: a filling step of supplying and filling a predefined amount of the magnetic viscosity fluid from a container 20 in which the magnetic viscosity fluid is stored to the magnetic viscosity fluid device 12; a measurement step of measuring a weight of the predefined amount of the magnetic viscosity fluid filled in the magnetic viscosity fluid device 12; a calculation step of calculating a specific gravity of the magnetic viscosity fluid filled in the magnetic viscosity fluid device 12 based on a measurement result of the weight and the predefined amount; and a selection step of selecting the magnetic viscosity fluid device 12 in which the specific gravity calculated in the calculation step is within a predefined tolerance range with respect to a predefined value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a magnetorheological fluid device in which a magnetorheological fluid is interposed between members and a force corresponding to the strength of a magnetic field applied to the magnetorheological fluid is transmitted between the members. [Background technology]

[0002] A magnetorheological fluid (hereinafter also referred to as "MRF") is a functional fluid whose viscosity changes depending on the strength of an applied magnetic field. A magnetorheological fluid device (hereinafter also referred to as "MRF device") using this MRF makes it possible to realize various operations and controls that are difficult to achieve with devices that do not use MRF. An example of an MRF device is the one disclosed in Patent Document 1.

[0003] MRF is a fluid in which magnetic particles such as iron are dispersed in a dispersion medium such as oil, and even when a magnetic field of the same strength is applied, the greater the proportion of magnetic particles contained in the MRF, the higher the viscosity will be, and the smaller the proportion of magnetic particles contained in the MRF, the lower the viscosity will be. Therefore, in order for an MRF device to perform as designed, it is important to adjust the proportion of magnetic particles in the MRF used in the MRF device (hereinafter also referred to as the "magnetic particle content") to a specified value.

[0004] Generally, when an MRF device user obtains MRF, they purchase a fixed amount of MRF in a container (e.g., 300 ml, 500 ml, 1000 ml, etc.). If the MRF device is small and only a small amount of MRF (e.g., a few ml or less) is used, the MRF can be efficiently filled into the MRF device by using a dispenser. When using a dispenser, the obtained MRF is transferred from the container to the syringe of the dispenser. Then, by pressurizing the syringe using the dispenser's function, a fixed amount of MRF is discharged from the outlet at the bottom of the syringe and filled into the MRF device. Dispensers that can be used in this way are disclosed in Patent Documents 2 to 4, etc. Containers may also be used as the syringe of a dispenser. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-152401 [Patent Document 2] Japanese Patent Application Publication No. 6-126227 [Patent Document 3] Japanese Patent Application Publication No. 8-80464 [Patent Document 4] Japanese Patent Application Laid-Open No. 2014-104453 Summary of the Invention [Problem to be solved by the invention]

[0006] In an MRF device, an MRF is interposed between components, and the force transmitted between the components is determined by the strength of the magnetic field applied to the MRF. Since the force transmitted between the components is determined by the viscosity of the MRF, any variation (error) in the state of the MRF filled into the MRF device (the proportion of magnetic particles contained in the MRF, the particle size distribution of the magnetic particles contained in the MRF) will result in variation in the force transmitted between the components of the MRF device. For an MRF device to perform as designed, it is necessary to ensure that the state of the MRF filled into each MRF device is uniform.

[0007] The factor that has the greatest impact on the force transmitted between components of an MRF device is the proportion of magnetic particles in the MRF. Due to the nature of MRF, the magnetic particles contained in the MRF do not mix completely with the dispersion medium. Furthermore, the magnetic particles contained in the MRF have a particle size distribution. Therefore, within the container, the dispersion state of the magnetic particles may vary depending on the location due to aggregation or sedimentation of the magnetic particles.

[0008] When the MRF device is small and the amount of MRF used is extremely small (for example, a few ml or less), a portion of the MRF contained in a syringe (container) is filled into the MRF device using a dispenser. However, if the dispersion state of the magnetic particles in the syringe is different, the magnetic particle content in the MRF filled into the MRF device may differ significantly from the magnetic particle content in the MRF originally contained in the syringe.

[0009] Thus, in the case of a small MRF device that requires only a very small amount of MRF, even if the magnetic particle content of the MRF in the syringe matches the specified value recommended by the manufacturer of the small MRF device, the magnetic particle content of the MRF actually filled in the small MRF device may differ significantly from the specified value, and there is a risk of variation in the proportion of magnetic particles contained in the MRF filled in the MRF device (magnetic particle content), which will prevent the MRF device from performing to its full potential.

[0010] In order to manage the state of the MRF filled into the MRF device, it is important to manage the magnetic particle content in the MRF. Therefore, when filling the MRF device with the MRF, simply measuring and managing the volume or weight of the MRF is not sufficient to accurately manage the state of the MRF.

[0011] The present invention was devised in consideration of the above-mentioned situation, and aims to provide a method for producing a magnetorheological fluid device that can reduce the variation (error) in the proportion of magnetic particles (magnetic particle content) in the magnetorheological fluid filled in the magnetorheological fluid device. [Means for solving the problem]

[0012] A first aspect of the present invention relates to a method for producing a magnetorheological fluid device, which is configured to interpose a magnetorheological fluid between components and transmit a force between the components according to the strength of the magnetic field applied to the magnetorheological fluid. The method includes a filling step of supplying a predetermined amount of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device to fill it; a measurement step of measuring the weight of the predetermined amount of the magnetorheological fluid filled in the magnetorheological fluid device; a calculation step of calculating the specific gravity of the magnetorheological fluid filled in the magnetorheological fluid device from the weight measurement result and the predetermined amount; and a selection step of selecting the magnetorheological fluid device whose specific gravity calculated in the calculation step is within a predetermined error range from a specified value.

[0013] A second aspect of the present invention relates to a method for producing a magnetorheological fluid device, which is configured to interpose a magnetorheological fluid between components and transmit a force between the components according to the strength of the magnetic field applied to the magnetorheological fluid, and is characterized by including a filling step of supplying a predetermined amount of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device to fill it; a measuring step of measuring the weight of the predetermined amount of the magnetorheological fluid filled in the magnetorheological fluid device; and a selection step of selecting the magnetorheological fluid device such that the weight measured in the measuring step is within a predetermined error range of a specified weight value calculated in advance from a specified value of the specific gravity of the magnetorheological fluid and the predetermined amount.

[0014] In addition, a third aspect of the present invention relates to a method for producing a magnetorheological fluid device, which is configured to interpose a magnetorheological fluid between components and transmit a force between the components corresponding to the strength of the magnetic field applied to the magnetorheological fluid, and is characterized by including: a filling step for supplying a predetermined weight of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device to fill it; a measurement step for measuring the volume of the predetermined weight of the magnetorheological fluid filled in the magnetorheological fluid device; a calculation step for calculating the specific gravity of the magnetorheological fluid filled in the magnetorheological fluid device from the volume measurement result and the predetermined weight; and a selection step for selecting the magnetorheological fluid device whose specific gravity calculated in the calculation step is within a predetermined error range from a specified value.

[0015] Furthermore, a fourth aspect of the present invention relates to a method for producing a magnetorheological fluid device, which is configured to interpose a magnetorheological fluid between components and transmit a force between the components according to the strength of the magnetic field applied to the magnetorheological fluid, and is characterized by including a filling step of supplying a predetermined weight of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device, filling it; a measuring step of measuring the volume of the predetermined weight of the magnetorheological fluid filled in the magnetorheological fluid device; and a selection step of selecting the magnetorheological fluid device such that the volume measured in the measuring step is within a predetermined error range with respect to a predetermined volume value calculated in advance from a predetermined value of the specific gravity of the magnetorheological fluid and the predetermined weight.

[0016] According to the above-described method for producing a magnetorheological fluid device, the specific gravity of the magnetorheological fluid filled in the magnetorheological fluid device is measured and controlled so that it falls within a predetermined error range from the specified value, making it possible to provide a high-quality magnetorheological fluid device that can perform as designed.

[0017] A fifth aspect of the present invention is a method for producing a magnetorheological fluid device according to any one of the first to fourth aspects, which includes a supply step of supplying an amount of the magnetorheological fluid from another container to the container after or while stirring the magnetorheological fluid in the other container before the filling step, in an amount sufficient to fill a plurality of the magnetorheological fluid devices.

[0018] A sixth aspect of the present invention is a method for producing a magnetorheological fluid device according to any one of the first to fourth aspects, wherein in the filling step, the magnetorheological fluid is supplied from the container to the magnetorheological fluid device and filled after or while stirring the magnetorheological fluid in the container. [Effects of the Invention]

[0019] According to the present invention, it is possible to reduce the variation (error) in the ratio of magnetic particles (magnetic particle content) in the magnetorheological fluid filled in the magnetorheological fluid device. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing an example of the configuration of a magnetorheological fluid filling device, a container, etc. for an MRF device according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 10 is a diagram showing a configuration example of a magnetorheological fluid filling device, a container, etc. for an MRF device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] First Embodiment A method for producing a magnetorheological fluid device according to a first embodiment of the present invention will be described below. The method for producing a magnetorheological fluid device described in this and other embodiments is a method for the steps subsequent to the step of filling the device with magnetorheological fluid, among the many steps carried out to produce a magnetorheological fluid device.

[0022] First, we will explain the MRF filling device 1 used when carrying out the method for producing a magnetorheological fluid device. As shown in Figure 1, the MRF filling device 1 is composed of an MRF supply device 2, a weight measuring device 3, etc.

[0023] The MRF supply device 2 is composed of a storage container 5, an agitator 6, a supply pipe 7, a container 20, a piston 21, a switching valve 22, a nozzle 23, a flow detector 8, a control device 10, and the like.

[0024] The storage container 5 contains the MRF 13 to be filled into the MRF device 12. The MRF device 12 is configured such that the MRF is interposed between members, and a force corresponding to the strength of the magnetic field applied to the MRF is transmitted between the members.

[0025] The agitator 6 is a device that agitates the MRF 13 in the storage container 5, and is mainly composed of an agitator blade 14, a shaft 15, a motor 16, etc. The agitator blade 14 is rotatably disposed in the storage container 5, and is rotated by the motor 16 via the shaft 15. In this embodiment, the drive of the motor 16 is controlled by the control device 10.

[0026] The base end of the supply pipe 7 is in communication with the bottom of the storage container 5, and the MRF 13 in the storage container 5 is supplied to the container 20 through the supply pipe 7.

[0027] The container 20 has a cylindrical shape with a bottom and can store an amount of MRF 13A that can be supplied to a plurality of MRF devices 12.

[0028] The piston 21 is slidably fitted into the container 20. The piston 21 is moved up and down by an actuator 24. When the actuator 24 moves the piston 21 upward relative to the container 20, the MRF 13 is supplied from the storage container 5 into the container 20.

[0029] The switching valve 22 is disposed between the supply pipe 7 and the container 20, and between the container 20 and the nozzle 23. In this embodiment, a three-position switching valve is used as the switching valve 22. When the switching valve 22 is in a first valve position, the supply pipe 7 and the container 20 are connected to each other, and the flow path connecting the container 20 and the nozzle 23 is closed. When the switching valve 22 is in a second valve position, the container 20 and the nozzle 23 are connected to each other, and the flow path connecting the supply pipe 7 and the container 20 is closed. When the switching valve 22 is in a third valve position, the flow path connecting the container 20 and the nozzle 23 is closed, and the flow path connecting the supply pipe 7 and the container 20 is closed. The switching valve 22 is not particularly limited, and may be configured to switch the flow paths of a three-way cock or the like. The switching position of the switching valve 22 is controlled by a switching valve actuator (not shown) driven based on commands from the control device 10.

[0030] The nozzle 23 supplies the MRF 13A in the container 20 to the MRF device 12 to fill it.

[0031] The flow rate detector 8 is provided to detect the flow rate of the MRF supplied from the nozzle 23 to the MRF device 12. The flow rate detector 8 detects the amount (volume) of MRF supplied from the container 20 to the MRF device 12. In this embodiment, the flow rate detector 8 transmits information about the flow rate of the MRF that has passed through the nozzle 23 to the control device 10.

[0032] The control device 10 controls the valve position of the switching valve 22, the drive of the actuator 24, the drive of the motor 16, and the like based on various input information.

[0033] The weight measuring device 3 measures the weight of the MRF filled in the MRF device 12. In this embodiment, the weight measuring device 3 measures the weight obtained by subtracting a predetermined weight from the weight of the MRF device 12 filled with the MRF as the weight of the MRF filled in the MRF device 12. Here, the predetermined weight is the weight of the MRF device 12 in a state where the MRF is not filled, and is registered in advance in the weight measuring device 3. The weight measured individually by the weight measuring device 3 before filling the MRF with the MRF may also be used as the predetermined weight. By individually measuring the predetermined weight, it is possible to suppress the influence of variations in the weight of the MRF device 12 before filling the MRF on the measurement results of the weight of the MRF. The weight measurement results are displayed on the display unit 3a of the weight measuring device 3, and information on the weight measurement results is transmitted to the control device 10.

[0034] It is desirable that the materials of the storage container 5, supply pipe 7, container 20, piston 21, stirring blade 14, shaft 15, etc. are non-magnetic so as not to affect the magnetic particles in the MRF.

[0035] Next, the steps of the manufacturing method for the magnetorheological fluid device will be described.

[0036] First, in the "MRF preparation process," magnetic particles and a dispersion medium are mixed in a preparation container (not shown), and an MRF is prepared so that the magnetic particle content is a predetermined value while measuring the specific gravity (volume and weight). It is assumed that the particle size distribution of the magnetic particles contained in the prepared MRF is the same each time. After powering on the control device 10, the prepared MRF is transferred to the storage container 5. Note that, in the initial state upon powering on, the control device 10 controls the valve position of the switching valve 22 to the third valve position.

[0037] Next, in the "supply step", the MRF 13 is stirred in the storage container 5 for a predetermined time, and then, preferably while continuing to stir the MRF 13, the MRF 13 in the storage container 5 is supplied to the container 20. At this time, the amount of MRF 13 supplied to the container 20 can be an amount that can fill multiple MRF devices 12.

[0038] In this embodiment, when a user performs a predetermined operation (for example, pressing a start button) on the operation unit of control device 10, motor 16 of agitator 6 rotates, and MRF 13 in storage container 5 is agitated by agitator blade 14 rotating together with motor 16, dispersing the magnetic particles in storage container 5. Then, when a predetermined time has elapsed since the start of agitation, control device 10 switches the valve position of switching valve 22 from the third valve position to the first valve position, thereby establishing communication between supply pipe 7A and container 20. Next, control device 10 drives actuator 24 to raise piston 21, thereby supplying MRF from storage container 5 to container 20 through supply pipe 7.

[0039] Thereafter, when piston 21 rises to a predetermined position and a predetermined amount of MRF is supplied to container 20, control device 10 stops actuator 24 from raising piston 21, and further switches switching valve 22 from the first valve position to the third valve position to close the flow path connecting supply pipe 7 and container 20. As a result, the supply of MRF from storage container 5 to container 20 stops.

[0040] Next, in the "filling step", the MRF 13A in the container 20 is supplied to the MRF device 12 by a predetermined specified amount.

[0041] In this embodiment, when a user performs a predetermined operation on the operation unit of the control device 10, the control device 10 switches the valve position of the switching valve 22 from the third valve position to the second valve position, thereby bringing the nozzle 23 into communication with the container 20. Furthermore, the control device 10 drives the actuator 24 to lower the piston 21, thereby supplying the MRF 13A in the container 20 to the MRF device 12. At this time, instead of continuously supplying the MRF 13A to the MRF device 12 until the amount of MRF reaches a specified value (specified amount), the MRF 13A may be supplied to the MRF device 12 in multiple batches.

[0042] Thereafter, when the flow rate detector 8 detects that the amount of MRF supplied to the MRF device 12 has reached a specified value (specified amount), the control device 10 stops the actuator 24 from lowering the piston 21. Furthermore, the control device 10 switches the valve position of the switching valve 22 from the second valve position to the third valve position to close the flow path connecting the nozzle 23 and the container 20. As a result, the supply of MRF 13A from the container 20 to the MRF device 12 stops. When multiple MRF devices 12 are to be continuously filled with MRF 13A, the control device 10 may control only the actuator 24 to lower and stop the piston 21 while keeping the switching valve 22 in the second valve position, without switching the valve position of the switching valve 22. Note that in this embodiment, the amount of MRF 13A supplied from the nozzle 23 to the MRF device 12 is extremely small (for example, a few ml or less).

[0043] Next, in the "weight measurement process," the weight of the specified amount of MRF supplied to the MRF device 12 is measured by the weight measuring instrument 3. In this embodiment, the measured weight is displayed on the display unit 3a of the weight measuring instrument 3, and measurement result information is sent to the control device 10.

[0044] Next, in the "calculation step," the specific gravity of the MRF is calculated from the measurement result of the weight of the MRF filled in the MRF device 12 and the specified amount of MRF filled in the MRF device 12. In this embodiment, the control device 10 calculates the specific gravity of the MRF filled in the MRF device 12 from the measurement result of the weight of the MRF filled in the MRF device 12 and a specified value previously set and stored in the control device 10, and the specific gravity is displayed on a display unit (not shown) provided in the control device 10. The specified amount of MRF filled in the MRF device 12 may be the amount (volume) of MRF actually supplied from the container 20 to the MRF device 12, measured by the flow detector 8.

[0045] Next, in the "selection process," "MRF devices" whose specific gravity calculated in the "calculation process" falls within a predetermined error range from the specified value are selected as those that have passed the quality standards. The selected "MRF devices" are shipped as products. On the other hand, for "MRF devices" whose specific gravity calculated in the "calculation process" falls outside the predetermined error range from the specified value, the filled MRF is temporarily removed, and the MRF is once again filled into the MRF device 12 using the MRF filling apparatus 1.

[0046] According to the above-described method for producing a magnetorheological fluid device, the specific gravity of the MRF filled in the MRF device 12 is measured and controlled so that it falls within a predetermined error range from the specified value. Since the error in the specific gravity of the solvent contained in the MRF is usually small, the specific gravity of the MRF (density of the MRF) is calculated by multiplying the density of water (1.0 g / cm 3 ) is large, the proportion of magnetic particles contained in the MRF is high, and the proportion of magnetic particles contained in the MRF is low if the specific gravity of the MRF is small. Therefore, if the specific gravity of the MRF filled in the MRF device 12 is measured and managed so that it is within a predetermined error range from the specified value, the variation in the force transmitted between the components of the MRF device can be reduced, and the MRF device 12 is more likely to perform as designed. Note that the particle size distribution of the magnetic particles contained in the MRF filled in the MRF device 12 can also affect the magnitude of the force transmitted between the components of the MRF device. However, since it is relatively easy to maintain a constant particle size distribution of the magnetic particles contained in the MRF when fabricating the MRF, this embodiment assumes that the particle size distribution of the magnetic particles contained in the MRF will be the same each time.

[0047] Furthermore, according to the above-described method for producing a magnetorheological fluid device, rework is reduced compared to when an error (deviation from the reference value of the force transmitted between components of the MRF device) is detected during finished product inspection of the MRF device 12, and manufacturing costs can also be reduced.

[0048] Second Embodiment In the first embodiment, MRF 13 is supplied from storage container 5 to MRF device 12 via container 20 to fill it, but as shown in Fig. 2, MRF 13 may be supplied directly from storage container 5 to MRF device 12. In this case, storage container 5 can be read as a container in the claims.

[0049] A method for producing a magnetorheological fluid device according to a second embodiment of the present invention will now be described with reference to Fig. 2. First, an MRF filling apparatus 1A and other components used when carrying out the method for producing a magnetorheological fluid device will be described. The MRF filling apparatus 1A is composed of an MRF supply device 2A, a weight measuring device 3, and other components. In the following description, when the functions of the components constituting each section are the same as those in the MRF filling apparatus 1 described in the first embodiment, the same reference numerals as in the first embodiment will be used and description thereof will be omitted even if the shape, etc., is slightly different.

[0050] The MRF supply device 2A of this embodiment is composed of a storage container (container) 5, an agitator 6, a supply pipe 7A, a flow rate detector 8A, a valve 9, a control device 10A, and the like.

[0051] The supply pipe 7A has a base end that communicates with the bottom of the storage container 5, and supplies the MRF 13 in the storage container 5 to the MRF device 12 to fill it.

[0052] The flow rate detector 8A is provided to detect the flow rate of the MRF flowing through the supply pipe 7A. This flow rate detector 8A detects the amount (volume) of MRF supplied from the storage container 5 to the MRF device 12. In this embodiment, the flow rate detector 8A transmits information about the flow rate of the MRF that has passed through the supply pipe 7A to the control device 10A.

[0053] Valve 9 is provided at a predetermined position (in this embodiment, at the tip) of supply pipe 7A, and opens and closes the flow path of supply pipe 7A. In this embodiment, a solenoid valve or the like is used as valve 9, and opening and closing of valve 9 is controlled by control device 10A.

[0054] The control device 10A controls the opening and closing of the valve 9, the driving of the motor 16, and the like based on various input information.

[0055] It is desirable that the materials of the storage container 5, supply pipe 7A, stirring blade 14, shaft 15, etc. be non-magnetic so as not to affect the magnetic particles in the MRF.

[0056] Next, the steps of the manufacturing method for the magnetorheological fluid device will be described.

[0057] First, a storage container 5 containing an MRF having a specific gravity of a predetermined value is prepared in the "MRF preparation process." The particle size distribution of the MRF 13 in the storage container 5 is assumed to be constant.

[0058] Next, in the "filling step", the MRF 13 is stirred in the storage container 5 for a predetermined time, and then a predetermined amount of the MRF 13 in the storage container 5 is supplied to the MRF device 12, preferably while the MRF 13 continues to be stirred.

[0059] In this embodiment, when a user performs a predetermined operation (for example, pressing a start button) on the operation unit of the control device 10A, the motor 16 of the agitator 6 rotates, and the MRF 13 in the storage container 5 is agitated by the agitator blades 14 rotating together with the motor 16, dispersing the magnetic particles in the storage container 5. Then, when a predetermined time has elapsed since the start of agitation, the control device 10A opens the valve 9 to supply and fill the MRF 13 from the storage container 5 through the supply pipe 7A to the MRF device 12. At this time, instead of continuously supplying the MRF 13 to the MRF device 12 until the amount of MRF reaches a specified value (specified amount), the MRF 13 may be supplied to the MRF device 12 in multiple batches.

[0060] Thereafter, when the control device 10A detects via the flow detector 8A that the amount of MRF supplied to the MRF device 12 has reached a specified value (specified amount), it closes the valve 9 to stop the supply of MRF 13 from the storage container 5 to the MRF device 12. At this time, the rotation of the motor 16 also stops. Note that the supply of MRF 13 from the storage container 5 to the MRF device 12 can be achieved by, for example, the action of the MRF 13's own weight or by pressurizing the inside of the storage container 5.

[0061] Next, in the "weight measurement process," the weight of the specified amount of MRF supplied to the MRF device 12 is measured by the weight measuring instrument 3. In this embodiment, the measured weight is displayed on the display unit 3a of the weight measuring instrument 3, and measurement result information is sent to the control device 10A.

[0062] Next, in the "calculation step," the specific gravity of the MRF is calculated from the measurement results of the weight of the MRF filled into the MRF device 12 and the specified amount of MRF filled into the MRF device 12. In this embodiment, the control device 10A calculates the specific gravity of the MRF filled into the MRF device 12 from the measurement results of the weight of the MRF filled into the MRF device 12 and a specified value previously set and stored in the control device 10A, and the specific gravity is displayed on a display unit (not shown) provided in the control device 10A. The specified amount of MRF filled into the MRF device 12 may be the amount (volume) of MRF actually supplied from the storage container 5 to the MRF device 12, measured by the flow detector 8A.

[0063] Next, in the "selection process," "MRF devices" whose specific gravity calculated in the "calculation process" falls within a predetermined error range from the specified value are selected as those that have passed the quality standards. The selected "MRF devices" are shipped as products. On the other hand, for "MRF devices" whose specific gravity calculated in the "calculation process" falls outside the predetermined error range from the specified value, the filled MRF is temporarily removed, and the MRF is once again filled into the MRF device 12 using the MRF filling apparatus 1.

[0064] According to the above-described method for producing a magnetorheological fluid device, the specific gravity of the MRF filled in the MRF device 12 is measured and managed so as to fall within a predetermined error range from a specified value, and therefore, the same effects as those of the first embodiment are achieved.

[0065] Third Embodiment In the embodiment described above, in the "calculation step," the specific gravity of the MRF is calculated based on the weight of the MRF filled into the MRF device 12 measured in the "weight measurement step." Then, in the "selection step," an "MRF device" in which the specific gravity of the MRF filled into the MRF device 12 falls within a predetermined error range from a specified value is selected as one that meets the quality standard. However, it is also possible to select an "MRF device" that meets the quality standard in the "selection step" without calculating the specific gravity of the MRF filled into the MRF device 12 in the "calculation step."

[0066] For example, a specified value for the weight of the MRF to be filled into the MRF device 12 is calculated in advance based on a specified value for the specific gravity of the MRF to be filled into the MRF device 12 and a specified amount (volume) of MRF to be filled into the MRF device 12. Then, in the "selection process," an "MRF device" is selected as one that meets the quality standards if the weight of the MRF filled into the MRF device 12 measured in the "weight measurement process" is within a specified margin of error with respect to the previously calculated specified value for the weight of the MRF.

[0067] In this way, by calculating in advance the specified value of the weight of MRF to be filled into the MRF device 12, it is possible to omit the "calculation step" from being performed each time MRF is filled into the MRF device 12.

[0068] <Fourth embodiment> In the above-described embodiments, the "supply step," "filling step," "calculation step," etc. are automatically performed by the control devices 10, 10A, etc., but these steps can also be performed manually by an operator. For example, in the "supply step," the MRF 13 in the storage container 5 can be stirred manually using a stirring tool without using the stirring device 6, and in the "filling step," the valve 9 can be opened and closed manually. Also, for example, in the "calculation step," the specific gravity can be calculated manually by an operator.

[0069] Fifth Embodiment In the first embodiment, a piston 21 is used as a configuration for supplying MRF from the storage container 5 to the container 20 and supplying MRF from the container 20 to the MRF device 12 to fill it, but this is not limited to the piston 21 and air pressure, etc. may also be used.

[0070] Sixth Embodiment In the first embodiment, the MRF 13 is stirred in the storage container 5 using the stirring device 6, but it is also possible to stir the MRF 13A in the container 20 using a stirring device as well.

[0071] Seventh Embodiment In the above-described embodiments, the amount (volume) of MRF supplied from the container 20 or the storage container 5 to the MRF device 12 is directly detected by the flow detectors 8, 8A, but it is also possible to indirectly detect it using other means instead of the flow detectors 8, 8A. For example, it is possible to use a photoelectric sensor to detect the liquid level of the MRF supplied to the MRF device 12, and by monitoring this liquid level, it is possible to fill a specified amount of MRF into the MRF device 12. Alternatively, it is possible to fill a specified amount of MRF into the MRF device 12 by controlling the actuator 24 with the control device 10, 10A to lower the piston 21 a specified distance and then stop it.

[0072] Eighth Embodiment In the above-described embodiments, the amount (volume) of MRF supplied from the container 20 or the storage container 5 to the MRF device 12 is detected by the flow detectors 8, 8A. However, instead of this, it is also possible to use a configuration in which a fixed amount of MRF is supplied to the MRF device 12 each time without measuring the amount (volume) of MRF using the flow detectors 8, 8A, etc.

[0073] Ninth Embodiment In the embodiment described above, the weight of the MRF filled in the MRF device 12 was measured by measuring the MRF device 12 after it had been filled with MRF using the weight measuring device 3. However, instead of this, it is also possible to measure the container 20 or storage container 5 before and after filling the MRF device 12 with MRF, and measure the weight of the MRF filled in the MRF device 12 based on the amount of weight loss of the MRF in the container 20 or storage container 5.

[0074] Tenth Embodiment In the previously described embodiment, a specified amount of MRF is supplied from container 20 or storage container 5 to MRF device 12, the weight of the MRF supplied to MRF device 12 is measured, and the specific gravity of the MRF filled in MRF device 12 is calculated from the weight measurement result and the specified amount. However, instead of this, a specified weight of MRF may be supplied from container 20 or storage container 5 to MRF device 12 in a "filling step," the volume of the specified weight of MRF supplied to MRF device 12 may be measured using flow detector 8, 8A, etc. in a "volume measurement step," and the specific gravity of the MRF filled in MRF device 12 may be calculated from the volume measurement result and the specified weight in a "calculation step." Then, in a "selection step," an "MRF device" whose specific gravity calculated in the "calculation step" falls within a specified error range from the specified value is selected as one that meets the quality standards.

[0075] In order to supply a specified weight of MRF from container 20 or storage container 5 to MRF device 12, it is possible to supply MRF until weight measuring device 3 detects that the weight of MRF filled in MRF device 12 has reached the specified weight, or until weight measuring device detects that the amount of weight loss on container 20 or storage container 5 supplying MRF has reached the specified weight. It is also possible to use a configuration in which a fixed amount of MRF is supplied to MRF device 12 each time without measuring the weight of the filled MRF using weight measuring device 3 or the like.

[0076] The volume of a specified weight of MRF supplied from the container 20 or storage container 5 to the MRF device 12 can be measured using a flow detector 8, 8A, etc. by measuring the amount of volume reduction based on images of the MRF in the container 20 or storage container 5 before and after the MRF is supplied.

[0077] Eleventh Embodiment In the tenth embodiment, in the "calculation step," the specific gravity of the MRF is calculated based on the volume of MRF filled in the MRF device 12 measured in the "volume measurement step." Then, in the "selection step," an "MRF device" in which the specific gravity of the MRF filled in the MRF device 12 falls within a predetermined error range with respect to a specified value is selected as one that meets the quality standard. However, it is also possible to select an "MRF device" that meets the quality standard in the "selection step" without calculating the specific gravity of the MRF filled in the MRF device 12 in the "calculation step."

[0078] For example, a specified value for the volume of MRF to be filled into MRF device 12 is calculated in advance based on a specified value for the specific gravity of the MRF to be filled into MRF device 12 and a specified weight of the MRF to be filled into MRF device 12. Then, in the "selection process," an "MRF device" is selected as one that meets the quality standards if the volume of MRF filled into MRF device 12 measured in the "volume measurement process" is within a specified error range with respect to the previously calculated specified value for the volume of MRF.

[0079] In this way, by calculating in advance the specified value of the volume of MRF to be filled into the MRF device 12, it is possible to omit performing the "calculation step" each time the MRF device 12 is filled with MRF.

[0080] <Twelfth embodiment> In the above-described embodiments, the MRF 13 in the storage container 5 may be evacuated as a pre-processing step prior to the "supplying step" or "filling step." Alternatively, the MRF 13 in the storage container 5 may be heated to a predetermined temperature as a pre-processing step prior to the "supplying step" or "filling step." By evacuating the MRF 13 or heating it, the air contained in the MRF 13 is removed, allowing for more accurate measurement of the specific gravity of the MRF. [Explanation of symbols]

[0081] 1,1A MRF filling equipment 2,2A supply device 3 Weight measuring device 5. Storage containers (other containers) 6. Mixing device 7,7A supply pipe 8,8A Flow Detector 9 Valves 10,10A control device 12 MRF Device (Magnetorheological Fluid Device) 13, 13A MRF (Magnetorheological Fluid) 14 Mixing blade 20 containers 21 Piston 22 Switching valve 23 nozzles 24 Actuators

Claims

1. A method for producing a magnetorheological fluid device, which is configured such that a magnetorheological fluid is interposed between members and a force corresponding to the strength of a magnetic field applied to the magnetorheological fluid is transmitted between the members, comprising: a filling step of supplying a predetermined amount of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device; a measuring step of measuring the weight of the predetermined amount of the magnetorheological fluid filled in the magnetorheological fluid device; a calculation step of calculating a specific gravity of the magnetorheological fluid filled in the magnetorheological fluid device from the weight measurement result and the predetermined amount; a selection step of selecting the magnetorheological fluid device whose specific gravity calculated in the calculation step falls within a predetermined error range with respect to a specified value; 1. A method of producing a magnetorheological fluid device, comprising:

2. A method for producing a magnetorheological fluid device, which is configured such that a magnetorheological fluid is interposed between members and a force corresponding to the strength of a magnetic field applied to the magnetorheological fluid is transmitted between the members, comprising: a filling step of supplying a predetermined amount of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device; a measuring step of measuring the weight of the predetermined amount of the magnetorheological fluid filled in the magnetorheological fluid device; a selection step of selecting the magnetorheological fluid device, the weight of which measured in the measurement step is within a predetermined error range with respect to a specified weight value calculated in advance from a specified value of the specific gravity of the magnetorheological fluid and the predetermined amount; 1. A method of producing a magnetorheological fluid device, comprising:

3. A method for producing a magnetorheological fluid device, which is configured such that a magnetorheological fluid is interposed between members and a force corresponding to the strength of a magnetic field applied to the magnetorheological fluid is transmitted between the members, comprising: a filling step of supplying a predetermined weight of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device; a measuring step of measuring the volume of the predetermined weight of the magnetorheological fluid filled in the magnetorheological fluid device; a calculation step of calculating a specific gravity of the magnetorheological fluid filled in the magnetorheological fluid device from the volume measurement result and the predetermined weight; a selection step of selecting the magnetorheological fluid device whose specific gravity calculated in the calculation step falls within a predetermined error range with respect to a specified value; 1. A method of producing a magnetorheological fluid device, comprising:

4. A method for producing a magnetorheological fluid device, which is configured such that a magnetorheological fluid is interposed between members and a force corresponding to the strength of a magnetic field applied to the magnetorheological fluid is transmitted between the members, comprising: a filling step of supplying a predetermined weight of the magnetorheological fluid from a container containing the magnetorheological fluid to the magnetorheological fluid device; a measuring step of measuring the volume of the predetermined weight of the magnetorheological fluid filled in the magnetorheological fluid device; a selection step of selecting the magnetorheological fluid device, the volume of which measured in the measurement step is within a predetermined error range with respect to a predetermined volume value calculated in advance from a predetermined value of the specific gravity of the magnetorheological fluid and the predetermined weight; 1. A method of producing a magnetorheological fluid device, comprising:

5. 5. A method for producing a magnetorheological fluid device according to claim 1, further comprising: a supply step of supplying the magnetorheological fluid from another container to the container in an amount sufficient to fill the plurality of magnetorheological fluid devices after or while stirring the magnetorheological fluid in the other container before the filling step; 10. A method for producing a magnetorheological fluid device comprising:

6. 5. A method for producing a magnetorheological fluid device according to claim 1, further comprising: In the filling step, the magnetorheological fluid is supplied from the container to the magnetorheological fluid device after or while being stirred in the container.

10. A method for producing a magnetorheological fluid device comprising:

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