JP2019113127A - Detection of piston unit position in actuator - Google Patents

Abstract

To provide an actuator which enables a position of a piston unit to be specified without using a linear variable differential transformer (LVDT).SOLUTION: An actuator 10 includes: a cylinder; a piston unit which is provided so as to be movable relative to the cylinder; a wire 55 attached to the piston unit; a drum 62 around which the wire 55 is wound and which rotates in response to movement of the piston unit relative to the cylinder; a torsion coil spring 64 which applies rotational force to the drum 62; and a sensor 65 which detects a rotation quantity of the drum 62.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to an actuator. The present disclosure relates more specifically to the detection of the position of a piston unit in an actuator.

  BACKGROUND ART In transportation equipment such as aircraft and various industrial machines, an actuator is widely used to drive movable members. A hydraulic actuator is known as one of such actuators. A hydraulic actuator generally includes a cylinder, a piston unit having a piston that divides the internal space of the cylinder into two pressure chambers, and a position sensor that detects the position of the piston unit relative to the cylinder. The piston unit is provided with a rod projecting to the outside of the cylinder, and the rod is connected to a movable member to be driven.

  In the hydraulic actuator, the servo mechanism controls the position of the piston unit. The servo mechanism controls the position of the piston unit in the cylinder by adjusting the pressure of the working fluid supplied to the two pressure chambers based on the position of the piston unit detected by the position sensor.

  A linear variable differential transformer (also called "LVDT" or "linear actuation transformer") is known as a position sensor applicable to hydraulic actuators. Japanese Patent Laid-Open No. 2011-127674 (Patent Document 1) discloses an LVDT that detects the position of a piston of a hydraulic actuator for driving a control surface of an aircraft.

  The LVDT generally comprises a rod-like probe fixed to a piston or a rod, a core provided at the tip of the probe, and a coil assembly fixed to a cylinder. The coil assembly has a primary coil excited by an AC input voltage, and a pair of secondary coils provided on both axial sides of the primary coil. The LVDT is configured to change the position of the core relative to the coil assembly as the core moves along the central axis in response to the displacement of the piston unit. The change in the position of the core relative to the coil assembly changes the differential voltage which is the difference between the induced voltages generated in the respective secondary coils, so that the position relative to the reference position of the core is detected based on the differential voltage. The reference position of the core is the position of the core at the null point where the differential voltage is zero. Since the core moves integrally with the piston unit, the position of the piston unit can be detected based on the differential voltage.

JP 2011-127674 A

  The LVDT requires the probe, the core, and the coil assembly to be arranged along the direction in which the piston slides, in principle. Thus, the arrangement of the components of the LVDT is not flexible.

  One of the objects of the present invention is to provide an actuator capable of specifying the position of the piston unit without using the LVDT.

  One of the more specific objects of the present invention is to increase the degree of freedom in the arrangement of members for detecting the position of the piston unit in the actuator.

  Other objects of the invention will become apparent by reference to the entire specification.

  An actuator according to one aspect of the present invention includes a cylinder, a piston unit movably provided relative to the cylinder, a wire attached to the piston unit, and the wire wound around, and the cylinder of the piston unit And a first sensor that detects the amount of rotation of the first drum.

  According to the actuator, since the wire attached to the piston unit is wound around the first drum, the amount of movement of the piston unit in the cylinder can be calculated by detecting the amount of rotation of the first drum. . That is, in the actuator, the movement amount of the piston unit is converted into the rotation amount of the drum by using a wire, and the movement amount of the piston unit is obtained by detecting the rotation amount of the drum. The position of the piston unit is identified based on the amount of movement of the piston unit. Thereby, the position of the piston unit can be specified without using the LVDT. The arrangement of the first drum and the first sensor can be flexibly determined by pulling around the wire.

  In LVDT, when the core or the probe is broken, the broken core or the probe may not move relative to the coil unit. In this case, breakage of the core or the probe can not be detected immediately. For example, when the LVDT is used in a posture in which the sliding direction of the core is horizontal, the broken core or probe remains at the broken position and does not move relative to the coil unit. It is difficult to detect immediately. On the other hand, according to the actuator according to one aspect of the present invention described above, when a member (for example, a wire) for measuring the position of the piston unit or the piston unit breaks, the first drum rotates differently. Since this is done, breakage or abnormality of the member can be determined immediately based on the detected value of the amount of rotation of the first drum.

  The actuator according to one aspect of the present invention further comprises first biasing means for applying a rotational force in a direction to wind the wire on the first drum.

  According to the actuator, when the piston unit moves in the direction of the first drum, the wire can be immediately wound on the first drum. Thereby, the bending of the wire can be suppressed. Further, the amount of movement of the piston unit can be accurately converted to the amount of rotation of the first drum.

  The actuator according to one aspect of the present invention further includes a second drum which is wound with the wire and which rotates in response to the movement of the piston unit relative to the cylinder, and a second sensor which detects the amount of rotation of the second drum. Prepare.

  According to the actuator, the breakage or abnormality in the cylinder unit, the first drum, the second drum, or the wire can be more accurately determined by comparing the detection value of the first sensor with the detection value of the second sensor. Can.

  The actuator according to an aspect of the present invention further comprises second biasing means for applying a rotational force in a direction in which the wire is wound on the second drum.

  According to the actuator, the wire can be immediately wound around the second drum by the biasing force from the second biasing means. Thereby, bending of the wire can be further suppressed. Further, the amount of movement of the piston unit can be accurately converted to the amount of rotation of the second drum.

  In the actuator according to one aspect of the present invention, the piston unit further includes a hollow piston rod connected to the piston, and the piston rod has a cylindrical guide member for guiding the wire.

  According to the actuator, the guide member restricts movement of the wire in the direction other than the winding direction. Thereby, bending of the wire can be further suppressed.

  In the actuator according to one aspect of the present invention, the wire is a stranded wire obtained by twisting a plurality of strands.

  According to the actuator, breakage of the wire can be detected more reliably.

  Various embodiments of the present invention provide an actuator that can locate the position of the piston without using an LVDT.

FIG. 1 schematically shows a system in which an actuator according to an embodiment of the present invention is used. It is sectional drawing of the actuator of FIG. It is an expanded sectional view which expands and shows a part of actuator of FIG. FIG. 7 is an enlarged cross-sectional view showing a part of an actuator according to another embodiment of the present invention. It is a figure which shows typically the wire drawn around by the pulley.

  Hereinafter, various embodiments of the present invention will be described with reference to the attached drawings as appropriate. The same referential mark is attached | subjected to the component which is common in each drawing. It should be noted that the drawings are not necessarily drawn to scale for the convenience of the description.

  The present invention can be applied to an actuator including a cylinder and a piston unit slidably provided relative to the cylinder. An actuator according to an aspect of the present invention and a system using the actuator will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a view schematically showing a moving blade drive system 1 for driving a moving blade 52 of an aircraft wing 50 by operating an actuator 10 according to an aspect of the present invention, and FIG. It is a front view. The moving blade 52 is, for example, a main control surface such as an aileron, a rudder, and an elevator, or a secondary control surface such as a flap and a spoiler. The moving blade drive system 1 is an example of a system in which the actuator according to the present invention is used. The actuator of the present invention can be used in various systems other than a rotor blade drive system.

  The moving blade drive system 1 includes an actuator 10 for driving the moving blades 52, a hydraulic pressure source 2 for supplying oil to the actuator 10, and a reservoir 3 for storing the oil discharged from the actuator 10. In the illustrated embodiment, the actuator 10 is a hydraulic actuator. It should be noted that the actuators to which the present invention can be applied are not limited to hydraulic actuators. For example, the present invention may also be applied to hydraulic actuators actuated by a hydraulic fluid other than pressure oil, and pneumatic actuators actuated by compressed air.

  The actuator 10 has a hollow cylinder 11 and a piston unit 12 provided in the cylinder 11. One of the longitudinal directions of the cylinder 11 is open and the other is closed. The cylinder 11 has a first cylinder member 11a formed in a tubular shape, and a second cylinder member 11b connected to one end of the first cylinder member 11a. The piston unit 12 is provided inside the first cylinder member 11a. A position detection mechanism 60 (described later) for detecting the position of the piston unit 12 is disposed inside the second cylinder member 11 b.

  The piston unit 12 has a piston 13 that divides the cylinder 11 into a first hydraulic chamber 15a and a second hydraulic chamber 15b, and a piston rod 14 connected to the piston 13. The piston rod 14 partially protrudes outside the cylinder 11.

  The piston rod 14 has a rod body 14 a and a rod end 14 b provided at the tip of the rod body 14 a. In the illustrated embodiment, the rod body 14a is formed in a hollow cylindrical shape. The rod body 14a may be formed in part or all in solid form. The piston rod 14 is connected to the moving blade 52 at the rod end 14 b. The rod end 14b is fixed to the rod body 14a by, for example, screwing. The rod body 14a and the rod end 14b may be formed as one member.

  The piston unit 12 is provided movably along the central axis A with respect to the cylinder 11. When the piston unit 12 moves in the first movement direction W1, the actuator 10 extends, and when the piston unit 12 moves in the second movement direction W2, the actuator 10 contracts. In the illustrated embodiment, the actuator 10 operates by supplying and discharging pressure oil to the hydraulic chamber 15a and the hydraulic chamber 15b. When the actuator 10 is actuated, the piston 13 is displaced in the cylinder 11 to drive the moving blade 52 through the piston rod 14.

  A control valve 4 is provided between the actuator 10 and the hydraulic pressure source 2 and the reservoir 3. The control valve 4 is connected to the hydraulic pressure source 2 by an oil passage 7a, and to the reservoir 3 by an oil passage 7b. The control valve 4 is connected to the first hydraulic chamber 15a of the hydraulic actuator 11 by the oil passage 8a, and is connected to the second hydraulic chamber 15b of the hydraulic actuator 11 by the oil passage 8b. The cylinder 11 has a first port 18a and a second port 18b. The oil passage 8a communicates with the first hydraulic chamber 15a via the first port 18a, and the oil passage 8b communicates with the second hydraulic chamber 15b via the second port 18b.

  The control valve 4 is, for example, a solenoid valve, and is configured to be able to switch the path of the hydraulic fluid communicated to each of the hydraulic chambers 15a, 15b based on a control signal input from the actuator controller 6 based on the command of the flight controller 5. Be done. For example, the control valve 4 supplies oil to the first hydraulic chamber 15a and discharges the oil from the second hydraulic chamber 15b, and discharges oil from the first hydraulic chamber 15a to the second hydraulic chamber 15b. It is configured to be switchable to a second communication position for supplying and a blocking position for blocking the supply of oil to the respective hydraulic pressure chambers 15a and 15b and the discharge of oil from the respective hydraulic pressure chambers 15a and 15b.

  The flight controller 5 specifies the position of the piston unit 12 based on a detection signal from the position detection mechanism 60 described later, and based on the specified position of the piston unit 12, the position of the moving wing 52 is in the flight state of the aircraft. Feedback control can be performed to achieve the target position according to the request.

  Next, referring to FIG. 3 in addition to FIG. 2, the position detection mechanism 60 for detecting the position of the piston unit 12 will be described. FIG. 3 is a schematic enlarged cross-sectional view showing a part of the actuator 10 in an enlarged manner.

  In the illustrated embodiment, the position detection mechanism 60 is provided in the cylinder 11. More specifically, the position detection mechanism 60 is provided in the storage chamber 17 in the cylinder 11. The storage chamber 17 is mainly defined by the second cylinder member 11 b and the partition wall 11 c. The partition wall 11c is provided at the boundary between the first cylinder member 11a and the second cylinder member 11b, and divides the internal space of the cylinder 11 into the storage chamber 17 and the other region. The partition wall 11c is integrally formed with the first cylinder member 11a and the second cylinder member 11b. The arrangement of the position detection mechanism 60 in the illustrated embodiment is exemplary. Part or all of the position detection mechanism 60 may be provided outside the cylinder 11.

  The position detection mechanism 60 is connected to the rod head 14 b by a wire 55. The wire 55 extends from the position detection mechanism 60 to the rod head 14 b through a communication hole formed in the vicinity of the central axis A of the partition 11 c. The wire 55 has one end attached to the rod head 14 b and the other end attached to the drum 62 of the position detection mechanism 60.

  A cylindrical straw guide 56 is attached to the rod head 14b. In the illustrated embodiment, the straw guide 56 is disposed coaxially with the rod body 14a and is screwed into the end of the rod head 14b. The straw guide 56 is an elongated cylindrical member, into which the wire 55 is inserted. The straw guide 56 is disposed inside the inner circumferential surface of the rod body 14a in the radial direction of the rod body 14a. The straw guide 56 may be formed such that its outer diameter is smaller than the inner diameter of the rod body 14a.

  One end of the wire 55 may be attached not to the rod head 14 b but to the rod body 14 a, the piston 13, or another portion of the piston unit 12. The wire 55 is, for example, a stranded wire obtained by twisting and bundling steel strands. The wire 55 preferably has high tensile strength.

  The position detection mechanism 60 includes a drum 62 around which a wire 55 is wound, a torsion coil spring 64 for applying a rotational force to the drum 62, and a sensor 65 for detecting the number of rotations and the rotation angle of the drum 62 from a reference position. And a connector 66 to which the signal line is connected. A signal line connected to the connector 66 is used to transmit a detection signal indicating the number of rotations and the rotation angle of the drum 62 detected by the sensor 65 to an external device such as the flight controller 5 or the like.

  The drum 62 is configured to be rotatable around a drum axis B extending in a direction orthogonal to the central axis A. The drum 62 includes a cylindrical spool 62a extending along the drum axis B, and flanges 62b and 62c respectively provided at both ends of the spool 62a in the drum axis B direction. The wire 55 is wound between the flange 62b and the flange 62c on the outer surface of the spool 62a.

  The drum 62 is provided with a rotating shaft 63a extending from the flange 62b along the drum axis B, and a rotating shaft 63b extending from the flange 62c along the drum axis B. The rotating shaft 63 b is attached to the cover 72 via a bearing 71. The cover 72 is fixed to the second cylinder member 11b by screws 73a and 73b. The cover 72 is attached to the second cylinder member 11 b after the position detection mechanism 60 is disposed in the storage chamber 17.

  The torsion coil spring 64 is provided between the drum 62 and the cover 72 so as to bias the drum 62 in the circumferential direction of the drum shaft B. One end of the torsion coil spring 64 is attached to the flange 62 c and the other end is attached to the cover 72. The torsion coil spring 64 is configured to bias the drum 62 in the winding direction for winding the wire 55. Thereby, when the piston unit 12 moves in the second movement direction W2 approaching the drum 62, the drum 62 is wound in the winding direction to wind the wire 55 around the drum axis B by the rotational force applied from the torsion coil spring 64. Rotate. Therefore, when the piston unit 12 moves in the second moving direction W2, the wire 55 is wound around the drum 62 by a length corresponding to the moving amount (moving distance) of the piston unit 12 in the second moving direction W2. On the other hand, when the piston unit 12 moves in the first movement direction W1 away from the drum 62, the wire 55 is pulled out of the drum 62 against the biasing force from the torsion coil spring 64. Therefore, when the piston unit 12 moves in the first movement direction W1, the drum 62 rotates in the feeding direction in which the wire 55 is fed out, whereby the wire 55 moves the piston unit 12 in the first movement direction W1 (movement ) Is pulled out of the drum 62 by a length corresponding to the distance). Thus, the drum 62 is configured to rotate in either the winding direction for winding the wire 55 or the feeding direction in which the wire 55 is pulled out, depending on the movement direction of the piston unit 12.

  The sensor 65 is a rotation sensor that detects the number of rotations of the drum 62 from the reference position and the rotation angle of the drum 62 in one rotation, and, for example, the number of rotations of a rotary encoder, hall element, RVDT, resolver, or the like. And known sensors capable of measuring the rotation angle, or a combination of these various sensors. The reference position of the drum 62 is, for example, the position of the drum 62 when the piston unit 12 is in the neutral position which is the center of the movable range in the central axis A direction.

Assuming that the number of rotations of the drum 62 from the reference position detected by the sensor 65 is n and the rotation angle in one rotation of the drum 62 is θ (0 ° ≦ θ ≦ 360 °), the rotation of the drum 62 from the reference position The amount P (absolute rotation angle) is calculated by the following equation.
P = 360 × n + θ (Equation 1)
The amount of rotation P is calculated by, for example, the flight controller 5 based on the number of rotations and the rotation angle of the drum 62 detected by the sensor 65.

Since the wire 55 is wound around the outer surface of the spool 62a of the drum 62, the wire wound around the drum 62 based on the rotation amount P of the drum 62 from the reference position and the shape of the outer surface of the spool 62a. The length of 55 can be calculated. For example, when the outer surface of the spool 62a has a cylindrical shape with a radius r centered on the drum axis B, when the drum 62 rotates from the reference position by the absolute rotation angle P, the drum 62 is wound by the rotation. The length L of the wire 55 is calculated based on the following equation.
L = 2πr × P / 360 (Equation 2)

  Next, operations of the moving blade driving system 1 and the actuator 10 will be described. At the start of operation, the piston unit 12 is in the neutral position. Therefore, the drum 62 is at the reference position.

  When the actuator controller 6 contracts the actuator 10, the control valve 4 is set to the first communication position based on the command from the flight controller 5, thereby supplying oil to the first hydraulic chamber 15a and the second hydraulic chamber 15b. Drain oil from Thus, the piston unit 12 moves from the neutral position in the second movement direction W2.

  When the piston unit 12 starts moving in the second moving direction W2, the tension acting on the wire 55 is slightly relaxed, so the drum 62 is rotated in the winding direction from the reference position by the biasing force from the torsion coil spring 64. Take up the wire 55. The biasing force from the torsion coil spring 64 causes the wire 55 to be wound around the drum 62 without bending. While the piston unit 12 moves from the neutral position by the distance L1 in the second movement direction W2, the drum 62 rotates in the winding direction from the reference position, and the wire 55 has the same length L1 as the movement amount of the piston unit 12. Only wind on the surface of the spool 62a.

  While the piston unit 12 moves from the neutral position by the distance L1 in the second movement direction W2, the rotation number n from the reference position of the drum 62 and the rotation angle θ in one rotation are detected by the sensor 65.

  A detection signal indicating the rotation number n from the reference position of the drum 62 and the rotation angle θ in one rotation is transmitted to the flight controller 5 through a signal line connected to the connector 66. The flight controller 5 calculates the amount of rotation (absolute rotation angle) P from the reference position of the drum 62 according to the above equation 1 based on the detection signal of the sensor 65.

  Next, the flight controller 5 calculates the length L of the wire 55 wound around the drum 62 while the drum 62 is rotated by the absolute rotation angle P from the reference position, according to the equation 2 above.

  The amount of movement of the piston unit 12 from the neutral position to the second movement direction W2 is equal to the length of the wire 55 wound around the drum 62 during this movement, so the flight controller 5 feeds back the actuator 10 When performing control, the value of the calculated winding length L of the wire 55 can be used as the amount of movement of the piston unit 12.

  On the other hand, when the actuator 10 is extended, the actuator controller 6 sets the control valve 4 to the second communication position to supply the oil to the second hydraulic chamber 15b and discharge the oil from the first hydraulic chamber 15a. Thus, the piston unit 12 moves in the first movement direction W1.

  When the piston unit 12 moves in the first movement direction W1, the wire 55 is pulled out of the drum 62. While the piston unit 12 moves from the neutral position by the distance L2 in the first movement direction W1, the wire 55 is pulled out of the drum 62 by the length L2. At this time, the drum 62 rotates in the feeding direction from the reference position.

  While the piston unit 12 moves from the neutral position by the distance L2 in the first movement direction W1, the rotation number n from the reference position of the drum 62 and the rotation angle θ in one rotation are detected by the sensor 65.

  Based on the rotation number n from the reference position of the drum 62 and the detection signal indicating the rotation angle θ in one rotation, the rotation amount (absolute rotation angle) P from the reference position of the drum 62 is It is calculated by the controller 5. Further, the length L of the wire 55 drawn from the drum 62 while rotating by the absolute rotation angle P is calculated by the flight controller 5 on the basis of the above equation 2.

  Since the movement amount of the piston unit 12 from the neutral position to the first movement direction W1 is equal to the length of the wire 55 drawn from the drum 62 during this movement, the flight controller 5 performs feedback control to the actuator 10 The calculated value L of the drawn-out length of the wire 55 can be used as the amount of movement of the piston unit 12.

  As described above, the actuator 10 converts the movement amount of the piston unit 12 from the neutral position to the rotation amount from the reference position of the drum 62 by using the wire 55, and the rotation amount of the drum 62 from the reference position Is detected by the sensor 65. Then, based on the amount of rotation of the drum 62 from the reference position detected by the sensor 65, the length of the wire 55 wound on the drum 62 by the movement of the piston unit 12 or the drum by the movement of the piston unit 12 The length of the wire 55 drawn from 62 can be calculated. Since the amount of movement of the piston unit 12 from the neutral position and the length of the wire 55 wound around or drawn from the drum 62 during this movement are equal, the drum during the movement of the piston unit 12 The calculated value of the length of the wire 55 wound around 62 or drawn from the drum 62 can be used as the amount of movement of the piston unit 12 to specify the position of the piston unit 12. Then, based on the position of the identified piston unit 12, feedback control of the actuator 10 can be performed.

  Another embodiment of the present invention is described with reference to FIG. FIG. 4 is an enlarged cross-sectional view showing a portion of the actuator 110 in another embodiment of the present invention. In the embodiment shown in FIG. 4, a position detection mechanism 160 is provided instead of the position detection mechanism 60 in the embodiment of FIG.

  As illustrated, a plate-shaped support plate 11 d extending along the central axis A is formed on the inner wall of the cylinder 11. The first storage chamber 17A is divided on one side of the support plate 11d in the rotation axis B direction by the support plate 11d, the second cylinder member 11b, and the partition wall 11c, and the other of the support plate 11d in the rotation axis B direction. The second storage chamber 17B is partitioned on the side.

  The position detection mechanism 160 has a first position detection unit 160A provided in the first storage chamber 17A and a second position detection unit 160B provided in the second storage chamber 17B.

  The first position detection unit 160A includes a first drum 162A, a first torsion coil spring 164A that applies a rotational force in a direction to wind the wire 55 around the first drum 162A, and the number of rotations and rotations of the drum 162A from a reference position. A first sensor 165A for detecting an angle and a connector 166A to which a signal line is connected are provided. The first drum 162A is provided with a first rotation shaft 163A extending along the drum axis B to the first sensor 165A. The first drum 162A is rotatably supported around the drum axis B by the support plate 11d and the first sensor 165A.

  The second position detection unit 160B is configured in the same manner as the first position detection unit 160A. That is, the second position detection unit 160B includes the second drum 162B, the second torsion coil spring 164B that applies a rotational force in the direction to wind the wire 55 around the second drum 162B, and the number of rotations of the drum 162B from the reference position. And a second sensor 165B for detecting the rotation angle, and a connector 166B to which a signal line is connected. The second drum 162B is provided with a second rotation shaft 163B extending along the drum axis B to the second sensor 165B. The second drum 162B is rotatably supported around the drum axis B by the support plate 11d and the second sensor 165B.

  The wire 55 has one end attached to the first drum 162A and the other end attached to the second drum 162B, and is wound around each of the first drum 162A and the second drum 162B. The wire 55 is attached to a pin 14c provided on the rod body 14a substantially at the center thereof. The pin 14c is a cylindrical member provided on the inner wall of the rod body 14a and extending in the direction orthogonal to the central axis A.

  When the piston unit 12 moves in the second movement direction W2, the first drum 162A and the second drum 162B are rotated around the drum axis B by the rotational force respectively applied from the first torsion coil spring 164A and the second torsion coil spring 164B. The wire 55 is rotated in the winding direction. Therefore, when the piston unit 12 moves in the second movement direction W2, the wire 55 is wound around the first drum 162A and the second drum 162B by a length according to the movement amount of the piston unit 12 in the second movement direction W2. Be done. On the other hand, when the piston unit 12 moves in the first movement direction W1, the wire 55 is pulled out from the first drum 162A and the second drum 162B. Therefore, when the piston unit 12 moves in the first movement direction W1, the wire 55 is pulled out from the first drum 162A and the second drum 162B by a length corresponding to the movement amount of the piston unit 12. As described above, the first drum 162A and the second drum 162B are configured to rotate in either the winding direction for winding the wire 55 or the drawing direction in which the wire 55 is drawn, depending on the moving direction of the piston unit 12. Be done.

  Next, the operation of the actuator 110 will be described. At the start of operation, the piston unit 12 is in the neutral position. Each of the first drum 162A and the second drum 162B may be at the reference position.

  When the piston unit 12 starts moving from the neutral position to the second movement direction W2 under the control of the actuator controller 6, the tension applied to the wire 55 is slightly relaxed, so the first drum 162A and the second drum 162B The wire 55 is wound by rotating in the winding direction from the reference position by the biasing force from the first torsion coil spring 164A and the second torsion coil spring 164B. While the piston unit 12 moves from the neutral position by the distance L1 in the second movement direction W2, each of the first drum 162A and the second drum 162B rotates in the winding direction from the reference position, and the wire 55 has a length L1. Take up only.

  While the piston unit 12 moves from the neutral position by the distance L1 in the second movement direction W2, the rotation speed n and the rotation angle θ in one rotation from the reference position of the first drum 162A are detected by the first sensor 165A. The rotation speed n from the reference position of the two drums 162B and the rotation angle θ in one rotation are detected by the second sensor 165B.

  The flight controller 5 calculates the amount of rotation (absolute rotation angle) from the reference position of the first drum 162A and the second drum 162B according to the above equation 1, and according to the above equation 2, the first drum 162A and the second drum 162B The length of the wire 55 wound around the first drum 162A and the second drum 162B while being rotated by the absolute rotation angle P from the reference position is calculated.

  The amount of movement of the piston unit 12 from the neutral position in the second movement direction W2, and the length of the wire 55 wound around the first drum 162A during this movement and the length of the wire 55 wound around the second drum 162B Since the length is equal, the flight controller 5 can use the calculated winding length of the wire 55 as the movement amount of the piston unit 12 when performing feedback control to the actuator 110.

  On the other hand, when the piston unit 12 starts moving from the neutral position to the first movement direction W2 under the control of the actuator controller 6, the wire 55 is pulled out from the first drum 162A and the second drum 162B. While the piston unit 12 moves from the neutral position by the distance L2 in the first movement direction W1, the wire 55 is pulled out from the first drum 162A and the second drum 162B by the length L2. At this time, both the first drum 162A and the second drum 162B rotate in the delivery direction from the reference position.

  While the piston unit 12 moves from the neutral position by the distance L2 in the first movement direction W1, the rotational speed n and the rotational angle θ in one rotation from the reference position of the first drum 162A and the second drum 162B are the first sensor It is detected by 165A and the 2nd sensor 165B.

  The flight controller 5 calculates the amount of rotation (absolute rotation angle) from the reference position of the first drum 162A and the second drum 162B according to the above equation 1, and according to the above equation 2, the first drum 162A and the second drum 162B The length of the wire 55 drawn from the first drum 162A and the second drum 162B while rotating from the reference position by the absolute rotation angle P is calculated.

  Since the movement amount of the piston unit 12 from the neutral position to the first movement direction W1 is equal to the length of the wire 55 drawn from the first drum 162A and the second drum 162B during this movement, the flight controller 5 When performing feedback control to the actuator 10, the calculated value of the drawn-out length of the wire 55 can be used as the movement amount of the piston unit 12.

  As described above, the actuator 110 converts the amount of movement of the piston unit 12 from the neutral position into the amount of rotation from the reference position of the first drum 162A and the second drum 162B by using the wire 55. The amount of rotation of the drum 162A and the second drum 162B from the reference position is detected by the first sensor 165A and the second sensor 165B. The first drum 162A and the second drum are moved by the movement of the piston unit 12 based on the amount of rotation from the reference position of the first drum 162A and the second drum 162B detected by the first sensor 165A and the second sensor 165B. The length of the wire 55 wound around 162B or the length of the wire 55 drawn out from the first drum 162A and the second drum 162B by the movement of the piston unit 12 can be calculated. The amount of movement of the piston unit 12 from the neutral position, and the length of the wire 55 wound around the first drum 162A and the second drum 162B during this movement or drawn from the first drum 162A and the second drum 162B The calculated lengths of the wires 55 wound around the first drum 162A and the second drum 162B or drawn out from the first drum 162A and the second drum 162B during the movement of the piston unit 12 are equal to The position of the piston unit 12 can be specified as the amount of movement of the piston unit 12. Then, based on the position of the identified piston unit 12, feedback control of the actuator 110 can be performed.

  In the embodiment of FIG. 4, the first position detection unit 160 </ b> A and the second position detection unit 160 </ b> B are disposed along the drum axis B. As a result, the size of the position detection mechanism 160 in the direction perpendicular to the drum axis B can be reduced. When the actuator 110 is attached to the wing of an aircraft, the wing of the aircraft needs to be aerodynamically thin. By arranging the actuator 110 such that the first position detection unit 160A and the second position detection unit 160B are juxtaposed along the drum axis B and the coil axis B is perpendicular to the thickness direction of the wing, The dimension in the direction perpendicular to the coil axis B can be reduced. Thus, the actuator 110 can be easily attached to the wing of an aircraft.

  Yet another embodiment of the present invention will be described with reference to FIG. A plurality of pulleys drawn wire 55 is shown in FIG. In the embodiment of FIG. 5, a plurality of pulleys 171a to 171d are drawn. The number and arrangement of the pulleys shown in FIG. 5 is exemplary and the wire 55 may be drawn around more or less than four pulleys.

  By arranging the wire 55 with a plurality of pulleys, the degree of freedom of the position detection mechanism 160 can be increased. As shown in FIG. 5, the position detection mechanism 160 may not be coaxial with the piston rod 14.

  In one aspect of the present invention, part or all of the position detection mechanism 160 can be disposed outside the cylinder 11 by pulling the wire 55 out of the cylinder 11. Thus, the cylinder 11 can be miniaturized.

  Also in the embodiment of FIG. 3 in which the wire 55 is wound by one drum, the wire 55 can be pulled around by using one or more pulleys. Thereby, the degree of freedom in the arrangement of the position detection mechanism 60 in the embodiment of FIG. 3 is further enhanced.

  According to the actuator according to each embodiment of the present invention described above, the wire 55 attached to the piston unit 12 is wound around the drum (the drum 62, the first drum 162A, and / or the second drum 162B) By detecting the amount of rotation of the drum from the reference position, the amount of movement of the piston unit 12 from the neutral position in the cylinder 11 can be calculated based on the detected detection value of the amount of rotation of the drum. That is, in the actuator according to each embodiment of the present invention, the movement amount of the piston unit 12 is converted into the rotation amount of the drum by using the wire 55, and the movement amount of the piston unit 12 is detected by detecting the rotation amount of the drum. Seeking. The position of the piston unit 12 is calculated from the amount of movement of the piston unit 12 from the neutral position. Thereby, the actuator according to each embodiment of the present invention can specify the position of the piston unit 12 without using the LVDT. Further, the arrangement of the position detection mechanism 60 and the position detection mechanism 160 can be flexibly determined by drawing the wire 55.

  According to the actuator according to each embodiment of the present invention described above, a member for measuring the position of the piston unit 12 (for example, the wire 55, each member constituting the position detection mechanism 60, each member constituting the position detection mechanism 160) When the piston rod 14 is broken, the wire 55 moves differently from the normal state. The abnormal movement of the wire 55 is detected by the sensor 65, the first sensor 165A, and / or the second sensor 165B to detect the number of rotations of the drum 62, the first drum 162A, and the second drum 162B and the rotation angle in one rotation. Based on this, it can be determined in the flight controller 5. For example, when the wire 55 is broken while the piston unit 12 is moving in the first movement direction W1, the rotation of the drum changes rapidly from the feeding direction to the winding direction. The flight controller 5 can determine that an abnormality or a failure has occurred based on the rapid change in the rotational direction. Other than this, detection of the number of rotations and the rotation angle in one rotation of the drum 62, the first drum 162A, and the second drum 163A by the sensor 65, the first sensor 165A, and / or the second sensor 165B by various algorithms Based on the value, an anomaly or failure determination may be made. The drum 62, the first drum 162A, and the second drum 162B are always urged in the winding direction of the wire 55 even when the actuator 10 or the actuator 110 is used in a posture in which the central axis A is horizontal. Therefore, based on the detected values of the amount of rotation of the drum, it is possible to detect an abnormality or a failure in the member for measuring the position of the piston unit 12.

  In the actuator 110, since the rotation amount of the first drum 162A and the second drum 162B is detected by the first sensor 165A and the second sensor 165B, the detection value by the first sensor 165A and the detection value by the second sensor 165B By comparing with the above, it is possible to more accurately determine the abnormality or the failure.

  According to the actuator according to each embodiment of the present invention described above, the movement of the piston unit 12 is transmitted to the position detection mechanism 60 and the position detection mechanism 160 by the wire 55. Since the portion of the wire 55 sliding along the central axis A does not make frictional contact with the piston unit 12 or other members (for example, the straw guide 56), seizure hardly occurs. Further, since the wire 55 is wound around the drum 62, the first drum 162A, and the second drum 162B, rolling friction occurs between the wire 55 and these drums, and sliding friction hardly occurs. Therefore, burn-in does not easily occur between the wire 55 and the position detection mechanism 60 and the position detection mechanism 160.

  The dimensions, materials, and arrangements of each component described herein are not limited to those explicitly described in the embodiments, and each component is optional within the scope of the present invention. Can be deformed to have the dimensions, materials, and arrangement of In addition, components that are not explicitly described in the present specification can be added to the described embodiments, or some of the components described in the embodiments can be omitted.

  The specific shapes and arrangements of the components of actuator 10 and actuator 110 specified herein are exemplary. The shapes, arrangements, and functions of the components of the actuator 10 and the actuator 110 may be changed as appropriate without departing from the spirit of the present invention.

  The torsion coil spring 64, the first torsion coil spring 164A, and the second torsion coil spring 164B apply a rotational force in the direction of winding the wire 55 to the corresponding drum 62, the first drum 162A, and the second drum 162B. It is an example of an energizing means. The member that applies the rotational force to the drum 62, the first drum 162A, and the second drum 162B is not limited to a torsion coil spring.

  Some or all of the control and operations performed by the flight controller 5 may be performed by the actuator controller 6 or one or more other controllers. Some or all of the controls and operations performed by the actuator controller 6 may be performed by the flight controller 5 or one or more other controllers.

10, 110 actuator 11 cylinder 12 piston unit 13 piston 14 piston rod 55 wire 56 straw guide 60, 160 position detection mechanism 62 drum 62a spool 62b, 62c flange 64 torsion coil spring 65 sensor 160A 1st position detection unit 160B 2nd position detection Unit 162A First drum 162B Second drum 164A First torsion coil spring 164B Second torsion coil spring 165A First sensor 165B Second sensor

Claims (6)

With the cylinder,
A piston unit movably provided relative to the cylinder;
A wire attached to the piston unit;
A first drum on which the wire is wound and which rotates in response to movement of the piston unit relative to the cylinder;
A first sensor that detects the amount of rotation of the first drum;
An actuator comprising:   The actuator according to claim 1, further comprising first biasing means for applying a rotational force in a direction in which the wire is wound up on the first drum. A second drum wound with the wire and rotating in response to movement of the piston unit relative to the cylinder;
A second sensor that detects the amount of rotation of the second drum;
The actuator according to claim 1, further comprising:   The actuator according to claim 3, further comprising second biasing means for applying a rotational force in a direction in which the wire is wound up on the second drum. The piston unit comprises a piston and a hollow piston rod connected to the piston,
The piston rod has therein a cylindrical guide member for guiding the wire.
The actuator according to any one of claims 1 to 4. The wire is a stranded wire obtained by twisting a plurality of strands.
The actuator according to any one of claims 1 to 5.

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