JP2009000366A - Actuator and artificial muscle using actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an actuator which uses electromagnets for supplying stable and large driving force by a simple structure. <P>SOLUTION: In the actuator equipped with an axial member, at least two independent sliding members which slide with respect to the axial member, a plurality of electromagnets disposed in series with respect to the sliding direction on the sliding members, and a current supplying part for supplying a current to the electromagnets, the polarity of the plurality of electromagnets is determined in a manner to generate repulsive force or attractive force in the direction to slide the sliding members for at least one of the directions of contracting and of extending the entire length of the actuator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an actuator that uses an electromagnet to supply a driving force by controlling an electric current, and an artificial muscle using the actuator.

  As a general actuator for obtaining a driving force, an actuator constituted by a combination of a motor and a speed reducer is known. While such an actuator can have a relatively simple structure, it is difficult to realize high back drivability (reverse mobility) due to the frictional resistance of the gears in the speed reducer that occurs during driving. Therefore, in recent years, actuators using electromagnets using the principle of linear motors are being developed as drive mechanisms that do not have frictional resistance such as gears when driven.

  As such an actuator, for example, as disclosed in Patent Document 1, an electromagnet is fixed to the outside of a cylindrical flexible member, and a plurality of permanent magnets are arranged in series inside the flexible member. There is something to have. Such an actuator is intended to obtain a linear driving force without causing frictional resistance by expanding and contracting a flexible member by controlling the amount of current supplied to an electromagnet arranged outside.

In addition, the actuator described in Patent Document 2 has a structure in which electromagnets are arranged in series at the contact portions of adjacent connectors in a plurality of connectors arranged in a chain, and current is supplied so as to repel these electromagnets. have. The actuator having such a structure is intended to control the length of a plurality of connectors configured in a chain.
JP-A-2005-58351 JP-A-8-182698

  However, such an actuator has the following problems. That is, since such an actuator uses the repulsive force or attractive force of an electromagnet as a driving force, when the electromagnets are arranged in series, the repulsion or attraction between the electromagnets locally due to the repulsive force or attractive force generated between the electromagnets. Occurs. Therefore, the force generated between the electromagnets (the pulling force or the repulsive force) is not uniform as a whole, the output as the actuator is not stable, and it becomes difficult to stably generate a large driving force. Problems arise.

  The present invention has been made to solve such problems, and is an actuator using an electromagnet, which can supply a stable large driving force with a simple structure, and uses such an actuator. It aims at providing the artificial muscle obtained by this.

  An actuator according to the present invention is for solving the above-described problems, and includes a shaft member, at least two independent sliding members that slide with respect to the shaft member, and the sliding member. An actuator comprising: a plurality of electromagnets arranged in series in the sliding direction; and a current supply unit that supplies current to the electromagnet, and at least one of a direction in which the entire length of the actuator contracts and a direction in which the actuator expands In the above, the polarities of the plurality of electromagnets are determined so that repulsive force or attractive force is generated in a direction in which the sliding member is slid.

  According to such an actuator, the repulsive force or attractive force of the plurality of electromagnets is added in the direction in which the sliding member slides relative to the shaft member. Therefore, it is possible to supply a large force, which is the sum of the repulsive force or attractive force of the electromagnet, as the driving force.

  In such an actuator, even if an electromagnet is arranged only on one sliding member and a permanent magnet is arranged on the other sliding member, a certain effect can be obtained. It is preferable to arrange the electromagnet so that the repulsive force or attractive force generated in the direction of sliding the sliding member is generated by the magnetic forces generated by these electromagnets. When the electromagnet is arranged in this way, it is possible to adjust the magnitude of the magnetic force of the electromagnet arranged on the sliding member, so that the driving force can be easily adjusted and a larger driving force can be obtained. .

  Further, in this way, the actuator has the electromagnets arranged on the sliding member each provided with a pair of polarities, the polarities of the electromagnets arranged opposite to each other, and the electromagnets arranged opposite to each other. It is more preferable that the repulsive force and the attractive force generated simultaneously with the respective polarities are configured to slide the sliding member in the direction in which the entire length of the actuator contracts or in the direction in which it extends. By configuring the actuator as described above, the repulsive force and attractive force generated from the electromagnet are combined and used as the driving force of the actuator, so that a larger force can be supplied as the driving force.

  The sliding member is preferably formed in a comb-like shape including a plurality of plate-like members arranged along the sliding direction with respect to the shaft member and a support member for supporting the plate-like member. Furthermore, it is preferable that the electromagnet is fixed to the plate member. According to such an actuator, the total repulsive force and attractive force obtained by the electromagnet can be used as a driving force for sliding the sliding member with a simple configuration.

  Note that a plurality of the supporting members may be provided, and it is preferable that the plate-like member is supported from both sides by these supporting members. In this case, the strength of the connection portion between the plate-like member and the support member is increased, so that the sliding member is less likely to be damaged even when a large driving force is output by the actuator.

  Further, in such an actuator, the electromagnets arranged on the plate-like member each have a pair of polarities, and the polarities of the electromagnets arranged opposite to each other and the electromagnets arranged facing away from each other. It is preferable that the repulsive force and the attractive force simultaneously generated by the polarities of each other act so as to slide the sliding member in the direction in which the entire length of the actuator contracts or in the direction in which it extends. As a result, the repulsive force and the attractive force acting on each other can be utilized as the driving force of the actuator for the electromagnet arranged on the plate-like member.

  Further, it is more preferable that the pair of polarities provided in the electromagnet is configured to be switchable, and the direction in which each sliding member slides can be reversed by switching the polarity. The actuator configured as described above can easily reverse the driving force of the actuator by simultaneously switching the polarities of the electromagnets.

  The sliding member may be made of any material as long as it has a certain degree of rigidity, such as metal, but is preferably formed of a non-metallic material that can pass through a magnetic field. Good. Actuators in which the sliding member is made of non-metal do not block the magnetic field generated from the electromagnet by the sliding member constituting the actuator, and the magnetic field generated from the electromagnet slides the sliding member without waste. Since it is used for the force, it becomes possible to obtain the driving force with high efficiency.

  In such an actuator, a cover for physically blocking the plurality of sliding members from the outside as a whole may be further provided. Such an actuator can be used in an environment such as outdoors or underwater because the sliding movement of the sliding member is not affected by the outside.

  Further, such an actuator may further include a distance measuring unit that measures a relative distance in the sliding direction between the sliding members. With this configuration, the amount of current supplied to the electromagnet can be adjusted based on the distance between the sliding members obtained by the distance measuring unit, so that more precise driving force control can be performed. Become. As the distance measuring unit as described above, a known measuring unit such as an optical sensor that measures the distance without contact or a rotary encoder can be used.

  The sliding member may further include a force detection unit that detects the magnitude of an external force acting in the sliding direction of the sliding member. According to such an actuator, since the force for sliding the sliding member can be changed according to the detected external force, the output driving force can be appropriately controlled as necessary.

  In such an actuator, an elastic body having at least a spring characteristic may be provided between the sliding members. With such an elastic body, for example, when a large force is applied in a direction in which the sliding member is attracted (that is, in the contraction direction), the sliding members can be prevented from interfering with each other and being damaged by the force. Therefore, when such an actuator is used to generate a driving force in the vertical direction, for example, the weight of the sliding member (or an object fixed to the sliding member) can be supported by the elastic force of the elastic body. As a result, it is possible to suppress the power consumed by the actuator.

  In addition, although an ordinary rubber member or the like may be used as such an elastic body, it is more preferable that the spring characteristics and the damping characteristics are variably controlled by an electric current. Such an actuator can control the output of the actuator by the force of sliding the sliding member generated by the electromagnet, the spring characteristic of the elastic body, and the damping specification. Therefore, for example, when an external force is applied to the sliding member or when the sliding member responds excessively to the supplied current amount, it is possible to suppress the vibration of the actuator and stabilize its operation. .

  The present invention also provides an artificial muscle using the actuator configured as described above. Since the above-mentioned actuator can quickly change the sliding direction of the sliding member, when such an actuator is used for an artificial muscle, the expansion and contraction operation of the artificial muscle should be performed with high response and high force. Can do.

  Such an artificial muscle may include a plurality of the actuators, and the actuators may be arranged in parallel. If it does in this way, it will become possible to obtain the big driving force required for the expansion-contraction operation | movement of a muscle by simple structure.

  As described above, according to the present invention, it is possible to provide an actuator capable of supplying a stable and large driving force with a simple structure, and an artificial muscle obtained by using such an actuator.

Embodiment 1 of the Invention
The actuator according to the first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 shows the appearance of the actuator in the present embodiment, and FIG. 2 is a side view of the actuator 1 shown in FIG.

  As shown in FIGS. 1 and 2, the actuator 1 includes a shaft member 10, a first sliding member 11 and a second sliding member 12 that slide along the shaft member, and on these sliding members. And a plurality of electromagnets 13 disposed in the. Note that the current supply unit that supplies current to the electromagnet 13 and the control unit that controls the amount of current supplied from the current supply unit are not shown in the present embodiment.

  The first sliding member 11 and the second sliding member 12 have substantially the same shape, and are disposed so as to face each other with the shaft member 10 as the center. In the present embodiment, the structure of the first sliding member 11 will be described in detail with reference to FIG. 3, and the description of the structure of the second sliding member 12 is omitted.

  As shown in FIG. 3, the first sliding member 11 includes a support member 111 that extends in the same direction as the shaft member, and a plurality of plate-like members that are supported so as to extend in a direction substantially perpendicular to the support member 111. 121, 122, 123, 124, 125 are formed in a comb-teeth shape. Each plate-like member has a through hole at the approximate center thereof, and the electromagnets 13 are arranged in the vicinity of the through-holes except for the first plate-like member 121. The plate-like member has a shape that is substantially rectangular in a plan view, but the present invention is not limited to this, and may be a shape that is substantially circular in a plan view or other shapes. Good. Further, the support member and the plate-like member are made of a non-metallic material that transmits a magnetic field, such as ceramic, and can efficiently transmit the magnetic field generated from the electromagnet.

  Further, on the outer surface of the first plate-like member 121 located at one end of the first sliding member 11, a cylindrical portion 121 a provided with a cavity through which the shaft member 10 penetrates in the vicinity of the through hole at the substantially center. Is provided. The cylindrical part 121a protrudes substantially perpendicularly outside the substantially center of the plate-like member 121 at the end, and the shaft member 10 penetrates the center thereof. The cylindrical portion 121a ensures that the sliding member slides along the shaft member.

  As described above, the electromagnet 13 is fixed on each plate-like member, and the shape thereof is not particularly limited. However, as shown in FIG. 4, the electromagnet 13 is similarly provided with a through-hole 13 a penetrating the shaft member, It is preferable that the plate-like member includes a through hole and surfaces (magnetic field generating surfaces) 131 and 132 that generate a substantially circular magnetic field fixed around the through hole. The electromagnet 13 disposed on the plate-like member is supplied with a current from a current supply unit (not shown) to generate a pair of polarities (N pole, S pole) that generate a magnetic field in a direction perpendicular to the magnetic field generating surface. ) Is provided on each magnetic field generating surface side. Details of the internal structure of the electromagnet will be omitted, but in these electromagnets, a magnetic field generating means such as a coil that generates a magnetic field by supplying a current is provided and supplied from the current supply unit. The strength of the generated magnetic field is variable depending on the amount of current. In addition, by switching the direction of the current supplied to the magnetic field generating means, the polarity generated on the magnetic field generating surface can be switched reversely.

  The polarities of the electromagnets 13 are such that when the current is supplied from the current supply unit and a magnetic field is generated from the electromagnets 13, the first sliding member 11 in the direction in which the entire length of the actuator 1 contracts and the direction in which it extends. The second sliding member 12 is determined to slide. That is, when a driving force is applied so that the actuator 1 contracts in the extending direction of the shaft member, the electromagnet 13 and the second sliding member 12 arranged on the first sliding member 11 as shown in FIG. The polarities of the electromagnets 13 arranged in the above are determined so that the electromagnets 13 arranged opposite to each other repel each other. If it does in this way, while the electromagnet 13 arrange | positioned at the 1st sliding member 11 and the electromagnet 13 arrange | positioned at the 2nd sliding member 12 adjoin and oppose, repulsive force arises, Since the adjacent back-facing members generate an attractive force, the repulsive force and the attractive force slide the first sliding member 11 and the second sliding member 12 in the direction in which the entire length of the actuator 1 contracts. It works to let you. That is, the repulsive force and attractive force generated from each electromagnet disposed on the sliding member are all used as the driving force for the entire length of the actuator 1 in the contraction direction.

  On the contrary, when the driving force is applied so that the actuator 1 extends in the direction in which the shaft member extends, as shown in FIG. 6, the electromagnet 13 and the second sliding member arranged on the first sliding member 11 The polarity of the electromagnet 13 arranged at 12 is determined so that the electromagnets arranged facing each other repel each other.

  If it does in this way, while the electromagnet 13 arrange | positioned at the 1st sliding member 11 and the electromagnet 13 arrange | positioned at the 2nd sliding member 12 adjoin and oppose, repulsive force arises, Since the adjacent back-facing members generate an attractive force, the repulsive force and the attractive force slide the first sliding member 11 and the second sliding member 12 in the direction in which the entire length of the actuator 1 extends. It works to let you. This makes it possible to generate a driving force so that the entire length of the actuator 1 is extended.

  In the actuator configured in this manner, the attractive force and repulsive force generated by the electromagnet disposed on the sliding member act in parallel as the driving force of the actuator 1, so that a large output can be obtained. In addition, since such actuators operate directly with the repulsive force of the magnetic force generated by the electromagnet, there is less leakage flux compared to actuators using the principle of linear motors that operate by electromagnetic induction, and large outputs can be efficiently performed. It is possible to obtain In addition, since a driving force can be applied in both the contracting direction and the extending direction along the shaft member, an effect of widening the range of use as an actuator can be obtained.

  In the present embodiment, the number of plate-like members and electromagnets provided on each sliding member is described using four examples. However, the present invention is not limited to this, and a required drive Needless to say, it can be designed as appropriate according to the magnitude of the force, the overall length of the required actuator, and the like.

  In addition, the actuator configured as described above may further include a cover C that physically blocks each sliding member from the outside, for example, as shown in FIG. This is more preferable because foreign matter or the like is not mixed between the plate-like member of the first sliding member 11 and the plate-like member of the second sliding member 12. FIG. 8 shows a state in which an actuator further including a cover for physically blocking each sliding member from the outside is used as an artificial muscle.

  As shown in FIG. 8, the artificial muscle 100 has a plurality of actuators (actuators 1a, 1b, 1c, 1d) arranged in parallel, and is driven at the end portions (cylindrical portions in the present embodiment) of the respective sliding members. The driven parts 200 and 300 corresponding to muscles to which force is applied are connected. As described above, the amount of movement of the driven part can be controlled according to the amount of current supplied to the actuator by determining the polarity of each actuator so that the non-driving part moves in the same direction. It becomes. In such an artificial muscle, since the driving force supplied by each actuator is added and output, it is possible to contract by a large force and to control the driving amount of each actuator independently. As a result, an effect that the shape of the driven part can be precisely changed is obtained.

  Note that examples of artificial muscles using such an actuator are not limited to those in which a plurality of actuators as described above are arranged in parallel, as shown in FIG. As shown in FIG. 10, the actuators arranged in series may be further arranged in parallel. As described above, when the actuators are arranged in series, the distance that the actuator expands and contracts can be increased, which is preferable when a larger expansion / contraction amount is required.

  Further, in order to more strictly control the amount of expansion / contraction obtained by the actuator, it is necessary to strictly feed back the relative positional relationship between the first sliding member 11 and the second sliding member 12 provided in the actuator. There is. That is, as shown in FIG. 11, an optical distance is provided as an example of a distance measuring unit at the end of the plate member (plate member 121) of one slide member (for example, the first slide member 11). May be provided, and a distance L in the sliding direction with respect to the other sliding member may be measured, and the measurement result may be transmitted to a control unit that controls the amount of current to be supplied. . In this way, the amount of expansion / contraction obtained by the actuator is fed back to the control unit, so that the drive amount of the actuator can be controlled more accurately.

  The sensor S described above is not limited to the one that optically measures the distance. For example, as shown in FIG. 12, a rotating part such as a gear provided rotatably on one sliding member and a contact member fixed to the other sliding member and contacting the rotating part, It is also possible to use a rotary encoder that calculates the amount by which the full length contracts or extends by the amount of rotation of the rotating unit. When the drive amount of the actuator is controlled by such a rotary encoder, since the measurement error can be suppressed as compared with a sensor that optically measures the distance, the drive amount of the actuator can be controlled more accurately.

  Although not shown in the drawings, in the above-described actuator, a force detection unit that detects an external force acting in the sliding direction on the sliding member may be provided. As an example of the force detector, one that detects the magnitude of a force such as a pressure sensor or an acceleration sensor, or one that detects the presence or absence of an external force such as a touch sensor can be used. In particular, in the case of a sensor that can detect the magnitude of an external force, such as a pressure sensor or an acceleration sensor, the magnitude of the external force obtained by the force detection unit is used for controlling the amount of current supplied to the electromagnet, thereby making the actuator more precise. It becomes possible to drive.

  In the above-described embodiment, the plate-like member provided on the sliding member has a structure in which only one end is supported by the support member. In such a cantilever beam structure, the structural strength of the sliding member may not be sufficiently obtained. Therefore, the following embodiment may be employed.

Embodiment 2 of the Invention
FIG. 13 shows the appearance of the actuator in the present embodiment (second embodiment), and FIG. 14 shows one sliding member (first sliding member 11 ′) of the actuator 1 ′ shown in FIG. ) Only from the side. In the description of the present embodiment, the same or similar components as those described in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 13, the actuator 1 ′ includes a first sliding member 11 ′ and a second sliding member 12 ′, and these sliding members are configured to be slidable along the shaft member. Yes. In addition, about the polarity of the electromagnet arrange | positioned at a sliding member, it has arrange | positioned similarly to the above-mentioned embodiment.

  As shown in FIG. 14, the first sliding member 11 ′ includes a first support member 111a and a second support member 111b, and plate members (121, 122, 123, 124, 125) is supported from both sides. The plate-like member is fixed so as to extend substantially vertically from each support member, or is configured integrally. As shown in FIG. 13, these sliding members are configured such that the respective plate-like members are substantially orthogonal to each other when viewed from the direction in which the shaft member 10 extends (the arrow direction Q in FIG. 13). Each sliding member is provided with a stopper (not shown) so that the sliding member does not rotate around the shaft member and the relative position of each sliding member is not changed except in the sliding direction. ing.

  In the actuator 1 ′ configured as described above, sufficient structural strength of the sliding member can be obtained, so that an effect that a sliding force of the sliding member, that is, a driving force can be output greatly can be obtained. In such an embodiment, in order to further increase the structural strength of the sliding member, not only the sliding member is supported from both sides, but also the plate-like member is supported by more supporting members. Also good. For example, the periphery of the plate member may be fixed by the support member within a range where the sliding members do not interfere with each other.

Embodiment 3 of the Invention
Next, a third embodiment of the present invention will be described with reference to FIG.

  FIG. 15 shows the appearance of the actuator according to the present embodiment (third embodiment), and has substantially the same configuration as that of the first embodiment described above. Also in the description of the present embodiment, the same or similar components as those described in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 15, the actuator 1 ″ includes a shaft member 10, a first sliding member 11 and a second sliding member 12 that slide along the shaft member 10, and on these sliding members. A plurality of electromagnets 13 are provided, wherein a current supply unit that supplies current to the electromagnet 13 and a control unit that controls the amount of current supplied from the current supply unit are implemented in this embodiment. In the embodiment, the illustration is omitted.

  In the present embodiment, the plate-like members provided in the first sliding member 11 and the second sliding member 12 are each provided with an electromagnet 13 at the approximate center thereof and elastic on the back surface on the fixed side of the electromagnet 13. The body 14 is fixed. That is, as shown in FIG. 15, the elastic body 14 is attached to a position where the first sliding member 11 and the second sliding member 12 are in contact with each other with the entire length of the actuator 1 ″ being most contracted. The elastic body 14 is configured to be supplied with a current from an external current supply unit (not shown) and change its spring characteristics and damping characteristics, and a known electromagnetic brake or the like is preferably used.

  By using such an elastic body, even when the entire length of the actuator 1 "is contracted, a force is applied in a direction in which the entire length of the actuator 1" is extended when each sliding member contacts the elastic member. It becomes possible. By using an elastic body having such spring characteristics and damping characteristics, the following effects can be obtained. In other words, when the sliding member responds excessively to the amount of current input to the electromagnet 13, the amount of current supplied to the elastic body 14 is controlled in addition to the amount of current supplied to the electromagnet 13. By controlling the spring characteristics and damping characteristics in accordance with the polarity of the electromagnet 13, the sliding amount of the sliding member can be adjusted. By doing so, the phenomenon that the sliding member vibrates is suppressed, and the operation of the entire actuator can be stabilized.

  Further, for example, even when an external force is applied to the sliding member of the actuator 1 "and the actuator 1" contracts, a force due to the spring characteristic of the elastic body 14 can be applied, and hence an attractive force due to magnetism generated from the electromagnet 13 Or, in addition to the repulsive force, a larger driving force can be applied. That is, for example, when the actuator 1 "is used in such a configuration that it slides in the vertical direction, the weight of the sliding member (and the driven object connected to the sliding member) acts, but the reaction force against this weight. Thus, it is necessary to supply a current to the electromagnet 13 in a state where only the weight is supported by applying the force that supports the own weight only by the elastic body 14. As a result, there is an effect that current consumption is suppressed.

  In the case of such an embodiment, if the actuator 1 ″ includes a force detector that detects an external force acting on the sliding member, it is easy to appropriately control the reaction force applied by the elastic body 14. Therefore, it is more preferable.

  In the present embodiment, an actuator 1 ″ is shown in which an elastic body 14 having a spring characteristic and a damping characteristic is provided at a portion where the sliding member interferes. As such an elastic body 14, a simple spring member or rubber is used. It is also possible to use an elastic body such as a member, and even when such an elastic body 14 is used, the impact due to the interference of the sliding member can be suppressed to some extent.

  As mentioned above, although the embodiment of the actuator concerning the present invention was described, the present invention is not limited to these embodiments. That is, for example, in the above-described embodiment, only the rod-shaped member that penetrates the sliding member is described as the shaft member, but instead of this, a cylindrical case 15 as shown in FIG. 16 is used. It may be used as a shaft member. That is, the cross section of the sliding member (that is, the shape of the plate-like member) is made to substantially coincide with the cross section of the case 15, and the outer peripheral surface of the sliding member moves (slides) along the inner periphery of the case 15. You can also If comprised in this way, while between the plate-shaped member of the 1st sliding member 11 and the plate-shaped member of the 2nd sliding member 12 can be physically interrupted from the outside, a sliding member and It is not necessary to provide a hole for penetrating the shaft member in the electromagnet or the like, and an effect is obtained that man-hours required when manufacturing the actuator are reduced.

  In the above-described embodiments, the driving force is supplied by the attractive force and the repulsive force from the plurality of electromagnets, but the electromagnet disposed on one sliding member is replaced with a normal permanent magnet. It is also possible to implement. If it does in this way, labor saving of the electric power used at the time of a drive, and man-hours, such as electrical wiring, can be reduced.

  In addition, the actuator according to the present invention can be used in many forms. For example, a parallel link as shown in FIG. 17 is configured using the actuator according to the present invention, and the link shape is changed by driving the actuator, whereby the internal force of the link is controlled by the driving force of the actuator, and the rigidity of the link Can be virtually changed.

  Further, for two triangular pyramid shaped rigid bodies as shown in FIG. 18, one rigid body is fixed, its vertex is connected to the vertex of the other rigid body by a ball joint, and the other end of the other rigid body is connected to the above-mentioned one. It is also possible to configure a three-dimensional parallel link that is connected by actuators such as Such a three-dimensional parallel link makes it possible to direct the bottom surface (output surface) of the other rigid body in an arbitrary direction with respect to the space by changing the length of the actuator.

  In addition, since the actuator according to the present invention can provide high output and high responsiveness, it can also be used for opening and closing an engine valve, for example. As a result, it is possible to electrically open and close the engine valve, which could not be realized with a direct acting motor such as a conventional electric rotary motor or linear motor.

  Furthermore, the actuator according to the present invention can be used by converting a linear motion into a rotational motion instead of using it only in the linear motion direction. For example, such an actuator can be used for driving a leg portion of a legged walking type robot, that is, a joint portion to which a large load such as a knee joint or a hip joint is applied. In particular, when a load in the vertical direction is always applied, it is preferable to use the actuator that can obtain the elastic force by the elastic body described in the third embodiment, because the power consumption of the actuator is suppressed. It is. In addition, an example in which a linear motion is converted into a rotational motion is not limited to this, and can also be used in a normal joint such as a robot arm or hand.

  Further, as described in the first embodiment, an artificial muscle in which a plurality of such actuators are arranged and the amount of expansion and contraction and the driving force are increased can also be used as the driving means for the robot joint as described above.

It is the schematic which shows roughly the external appearance of the actuator which concerns on 1st Embodiment. It is the schematic which shows a mode that the actuator shown in FIG. 1 was seen from the side. It is a figure which represents notionally the structure of the 1st sliding member which comprises the actuator shown in FIG. 1 and FIG. It is a conceptual diagram which shows an example of the electromagnet used for the actuator which concerns on this embodiment. It is the schematic which shows the example which determined the polarity of the electromagnet arrange | positioned at the actuator shown in FIG. 1 so that the full length of an actuator might shrink | contract. It is the schematic which shows the example which determined the polarity of the electromagnet arrange | positioned at the actuator shown in FIG. 1 so that the full length of an actuator might expand | extend. FIG. 2 is a schematic view showing an example in which the actuator shown in FIG. 1 further includes a cover that physically blocks each sliding member from the outside. It is the schematic which shows the example which comprised the artificial muscle using the actuator shown in FIG. It is the schematic which shows the example which arrange | positions the actuator shown in FIG. 1 in series, and comprises an artificial muscle. It is the schematic which shows the example which comprises what arranged the actuator shown in FIG. 1 in series, arrange | positions in parallel, and comprises an artificial muscle. In the embodiment shown in FIG. 1, it is the schematic which shows the example which provided the sensor which optically measures the distance about the sliding direction between sliding members. It is the schematic which shows the example which used the rotary encoder about the sensor of the actuator shown in FIG. It is the schematic which shows roughly the external appearance of the actuator which concerns on 2nd Embodiment. It is the schematic which shows a mode that one sliding member of the actuator shown in FIG. 13 was seen from the side. It is the schematic which shows roughly the external appearance of the actuator which concerns on 3rd Embodiment. It is the schematic which shows an example of embodiment of the actuator using the cylindrical case which covers the exterior as a shaft member which a sliding member slides. It is the schematic which shows the example which comprised the parallel link using the actuator which concerns on this invention. It is the schematic which shows the example which comprised the three-dimensional parallel link using the actuator which concerns on this invention.

Explanation of symbols

1, 1 ', 1 ", 1a, 1b, 1c, 1d ... Actuator 10 ... Shaft member 11, 11' ... Sliding member (first sliding member)
12, 12 '... sliding member (second sliding member)
DESCRIPTION OF SYMBOLS 13 ... Electromagnet 111 ... Support member 111a ... 1st support member 111b ... 2nd support member 121,122,123,124,125 ... Plate-shaped member 121a ... Cylindrical shape Member 13a ... Through-hole 131, 132 ... Magnetic field generating surface 14 ... Elastic body 15 ... Cover 100 ... Artificial muscle S ... Distance measuring part (sensor)

Claims (14)

  A shaft member, at least two independent sliding members that slide with respect to the shaft member, a plurality of electromagnets arranged in series in the sliding direction on the sliding member, and a current to the electromagnet An at least one of a direction in which the entire length of the actuator contracts and a direction in which the actuator extends, so as to generate a repulsive force or an attractive force in a direction in which the sliding member is slid. The actuator is characterized in that polarities of the plurality of electromagnets are determined.   2. An electromagnet is disposed for each of the sliding members, and repulsive force or attractive force generated in a direction in which the sliding member is slid is generated by magnetic forces generated by these electromagnets. The actuator described.   The sliding member is formed in a comb-like shape including a plurality of plate-like members arranged along the sliding direction with respect to the shaft member, and a support member that supports the plate-like member, and the electromagnet includes The actuator according to claim 1, wherein the actuator is fixed to the plate-like member.   The actuator according to claim 3, wherein a plurality of the support members are provided to support the plate-like member from both sides.   The electromagnets arranged on the plate-like member each have a pair of polarities, and are generated simultaneously by the polarities of the electromagnets arranged opposite to each other and the polarities of the electromagnets arranged facing each other. 5. The actuator according to claim 3, wherein the repulsive force and the attractive force act so as to slide the sliding member in a direction in which the entire length of the actuator contracts or a direction in which the actuator extends.   6. The actuator according to claim 5, wherein a pair of polarities provided in the electromagnet is switchable, and the sliding direction of each sliding member can be reversed by switching the polarities.   The actuator according to any one of claims 1 to 6, wherein the sliding member is made of a non-metallic material capable of passing a magnetic field.   The actuator according to claim 1, further comprising a cover that physically blocks the plurality of sliding members from the outside.   The actuator according to claim 1, further comprising a distance measuring unit that measures a relative distance in a sliding direction between the sliding members.   The actuator according to any one of claims 1 to 9, further comprising a force detection unit that detects a magnitude of an external force acting on the sliding member in a sliding direction of the sliding member.   The actuator according to any one of claims 1 to 10, wherein an elastic body having at least a spring characteristic is provided at a position where the sliding members are in contact with each other.   The actuator according to claim 11, wherein the elastic body has a spring characteristic and a damping characteristic variably controlled by an electric current.   An artificial muscle comprising the actuator according to any one of claims 1 to 12, wherein an expansion and contraction operation is performed by the actuator.   The artificial muscle according to claim 13, comprising a plurality of the actuators, wherein the actuators are arranged in parallel.

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