JP2019113150A - Actuator - Google Patents

Abstract

To provide an actuator that allows health monitoring of a differential transformer to be performed.SOLUTION: An actuator 10 comprises a cylinder 11, a piston unit 12 slidably provided in the cylinder, a differential transformer 20 for detecting a position of the piston unit with respect to the cylinder, a closed loop structure body 50 comprising a closed loop structure of which at least a portion is provided in the differential transformer, and a sensor unit 30 for detecting a physical change in the closed loop structure body.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to an actuator. The present disclosure relates more specifically to an actuator provided with a differential transformer.

  In transportation equipment such as aircraft and various industrial machines, an actuator is used to drive a movable member. One type of actuator is a hydraulic actuator. 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 detector that detects the position of the piston unit relative to the cylinder. The piston unit is provided with a piston rod that protrudes to the outside of the cylinder, and the piston 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 detector.

  A differential transformer is known as a position detector applicable to a hydraulic actuator. The hydraulic actuator for driving the control surface of an aircraft is disclosed by Unexamined-Japanese-Patent No. 2011-127674 (patent document 1), and the position of the piston in the said actuator is linear which is 1 type of a differential transformer. It is detected by a variable differential transformer (LVDT).

  The LVDT generally comprises a rod-like probe fixed to a piston or a piston 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 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

  In order for the actuator to operate properly, it is necessary to correctly detect the position of the piston unit by a differential transformer such as LVDT.

  One of the objects of the present disclosure is to provide an actuator capable of performing health monitoring of differential transformers. Other objects of the present disclosure 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 slidably provided in the cylinder, a differential transformer for detecting the position of the piston unit with respect to the cylinder, and at least a part of the differential A closed loop structure provided in a transformer, and a sensor unit for detecting a physical change in the closed loop structure.

  According to the above-described actuator, since the sensor unit detects a physical change in the closed loop structure, the soundness of the differential transformer can be determined based on the detection result. Also, the closed loop structure can provide structural redundancy to the differential transformer. Thereby, breakage can be made less likely to occur in the differential transformer.

  In the actuator according to one aspect of the present invention, the sensor unit is configured to detect a physical quantity related to current or magnetic flux flowing through the closed loop structure.

  According to the above-described actuator, the soundness of the differential transformer can be determined by detecting the current or magnetic flux flowing through the closed loop structure by the sensor unit. For example, when the differential transformer breaks or degrades, the electrical resistance or magnetic resistance of the closed loop structure changes, so by detecting a change in current or magnetic flux flowing through the closed loop structure formed in the differential transformer, The soundness of the differential transformer can be monitored.

  In the actuator according to one aspect of the present invention, the sensor unit is configured to detect that the closed loop structure is opened.

  According to the above-described actuator, breakage or deterioration of the differential transformer can be detected by detecting that the closed loop structure formed in the differential transformer is opened by the sensor unit.

  In the actuator according to one aspect of the present invention, the sensor unit is configured to detect that the closed loop structure is opened based on the current value of the current flowing through the closed loop structure.

  According to the above-mentioned actuator, it is possible to detect breakage or deterioration of the differential transformer by detecting that the closed loop structure is opened by the current value of the current flowing through the closed loop structure.

  In the actuator according to one aspect of the present invention, the closed loop structure is made of a magnetic material, and the sensor unit detects that the closed loop structure is opened by detecting a leakage flux from the closed loop structure. Is configured as.

  According to the above-described actuator, it is possible to detect breakage or deterioration of the differential transformer by detecting that the closed loop structure is opened by leakage flux from the closed loop structure.

  In the actuator according to one aspect of the present invention, the differential transformer has a probe attached to the piston unit, and at least a part of the closed loop structure is formed on the probe.

  According to the above-described actuator, breakage or deterioration of the probe can be detected.

  In the actuator according to one aspect of the present invention, the closed loop structure is made of a material having higher toughness than the probe.

  According to the above-described actuator, structural strength can be imparted to the probe by the high toughness closed loop structure. This makes it difficult for the probe to be broken.

  In the actuator according to one aspect of the present invention, the differential transformer has a core provided to the probe, and at least a part of the closed loop structure is formed on the probe and the core.

  According to the above-described actuator, breakage or deterioration of the core can also be detected.

  In the actuator according to one aspect of the present invention, the closed loop structure is made of a material having higher toughness than the core.

  According to the above-described actuator, structural strength can be imparted to the core by the high toughness closed loop structure. This makes it difficult for the core to be broken.

  In the actuator according to one aspect of the present invention, at least a part of the closed loop structure is provided in a through hole formed in at least one of the probe and the core.

  The above-described actuator can form a closed loop structure so as not to disturb the operation of the differential transformer.

  In the actuator according to one aspect of the present invention, the through hole is formed to have a first hole portion having a first inner diameter and a second hole portion having a second inner diameter smaller than the first inner diameter. The second hole portion is disposed more distally than the first hole portion from an attachment position at which the probe is attached to the piston unit.

  According to the above-described actuator, water accumulated in the differential transformer can be scraped out via the through hole.

  In the actuator according to one aspect of the present invention, at least a part of the closed loop structure is provided inside a groove formed in at least one of the probe and the core.

  The above-described actuator can form a closed loop structure so as not to disturb the operation of the differential transformer.

  In the actuator according to one aspect of the present invention, the groove is formed to have a first groove portion having a first outer diameter and a second groove portion having a second outer diameter larger than the first outer diameter. The second groove portion is arranged more distally than the first groove portion from an attachment position where the probe is attached to the piston unit

  According to the above-described actuator, water accumulated in the differential transformer can be scraped out via the groove.

  In the actuator according to one aspect of the present invention, the closed loop structure is formed in a helical shape on at least one of the probe and the core.

  According to the above-described actuator, at least one of the probe and the core can be reinforced by the spiral shaped closed loop structure.

  In the actuator according to one aspect of the present invention, the sensor unit further includes a lamp that lights, blinks, or extinguishes in response to a physical change in the closed loop structure.

  According to the above-described actuator, breakage or deterioration of the differential transformer can be transmitted by the lamp.

  In the actuator according to one aspect of the present invention, the sensor unit is configured to transmit a signal generated in response to a physical change in the closed loop structure to an external device.

  According to the above-described actuator, breakage or deterioration of the differential transformer can be monitored by an external device.

  Embodiments of the present invention provide an actuator capable of performing health monitoring of differential transformers.

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 a figure which shows typically the differential transformer with which the actuator of FIG. 1 is provided. It is a typical sectional view of a probe and a core with which a differential transformer of Drawing 3 is provided. It is sectional drawing which shows typically the cross section which followed the II line of FIG. 4 a. It is a typical sectional view of a probe and core with which a differential transformer in another embodiment of the present invention is provided. It is sectional drawing which shows typically the cross section which followed the II-II line of FIG. 5 a. It is a typical sectional view of a probe and core with which a differential transformer in another embodiment of the present invention is provided. It is sectional drawing which shows typically the cross section which followed the III-III line of FIG. 6 a. It is a typical sectional view of a probe and core with which a differential transformer in another embodiment of the present invention is provided. It is sectional drawing which shows typically the cross section which followed the IV-IV line of FIG. 7 a. It is a typical sectional view of the core with which the differential transformer in another embodiment of the present invention is provided. It is a typical sectional view of the core with which the differential transformer in another embodiment of the present invention is provided. It is a figure which shows typically the cross section of the probe with which the differential transformer in another embodiment of this invention is provided, and a core. It is a block diagram explaining the sensor unit in another embodiment of the present invention. It is a typical sectional view of a probe and core with which a differential transformer in another embodiment of the present invention is provided. It is sectional drawing which shows typically the cross section which followed the VV line | wire of FIG. 12 a.

  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, a piston unit slidably provided in the cylinder, and a differential transformer that detects the position of the piston unit. An actuator according to an aspect of the present invention and a system in which the actuator is used 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 1A of an aircraft by operating an actuator 10 according to one aspect of the present invention, and FIG. FIG. The moving blade 1A 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 according to the present invention can be used in various systems other than the rotor blade drive system.

  The moving blade drive system 1 includes an actuator 10 for driving the moving blade 1A, a hydraulic pressure source 2 for supplying pressure 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 (directions along the axis A) of the cylinder 11 is open and the other is closed. The cylinder 11 has a first cylinder member 11a, a second cylinder member 11b, and a third cylinder member 11c. The first cylinder member 103a, the second cylinder member 103b, and the third cylinder member 103c are fixed to one another.

  The first cylinder member 11a is formed in a bottomed cylindrical shape in which one in the longitudinal direction is open and the other is closed. The third cylinder member 11c is formed in a cylindrical shape with both ends in the longitudinal direction open, and is screwed into the inside of the first cylinder member 11a. The second cylinder member 11b is formed in a cylindrical shape with both ends in the longitudinal direction open, and is fitted inside the first cylinder member 11a and the third cylinder member 11c. In the illustrated embodiment, the first cylinder member 103a, the second cylinder member 103b, and the third cylinder member 103c described in this specification are examples, and the first cylinder member 103a, the second cylinder member 103b, and the second cylinder member 103b are illustrated. The shape, arrangement, and joining aspect of the third cylinder member 103c are not limited to the aspect explicitly described herein. The cylinder 11 may include members other than the first cylinder member 103a, the second cylinder member 103b, and the third cylinder member 103c.

  The piston unit 12 has a piston 13, a piston rod 14 connected to the piston 13, and a clevis 15 attached to the piston rod 14. The piston 13 and the piston rod 14 are disposed inside the cylinder 11. The piston rod 14 partially protrudes to the outside of the cylinder 11 through the opening of the cylinder 11.

  The piston 13 is formed in a cylindrical shape. The piston 13 is disposed inside the first cylinder member 11a such that the outer peripheral surface thereof abuts on the inner peripheral surface of the first cylinder member 13a. Thus, the piston 13 divides the cylinder 11 into the first hydraulic chamber 19a and the second hydraulic chamber 19b.

  The piston rod 14 has a first cylindrical member 14a formed in a hollow cylindrical shape, a solid portion 14b closing one end of the first cylindrical member 14a, and a first cylindrical portion from the solid portion 14b. And a cylindrical second cylindrical member 14c extending to the side opposite to the member 14. The piston rod 14 is provided such that its outer peripheral surface abuts on the inner peripheral surface of the second cylinder member 103 b. A seal member such as an O-ring is disposed between the outer peripheral surface of the piston rod 14 and the inner peripheral surface of the second cylinder member 103b. The pressure oil is sealed in the first hydraulic chamber 19a by the seal member.

  The clevis 15 has an attaching portion 15a rotatably attached to the moving blade 1A, and a shaft portion 15b projecting from the attaching portion 15a. An external thread is formed on the outer surface of the shaft portion 15b, and an internal thread is formed on the inner circumferential surface of the second cylindrical member 14c. The shaft portion 15 b is screwed into the second cylindrical member 14 c. The fixing ring 17 is screwed into the shaft portion 15 b via the key member 16. The shaft portion 15 b is tightened to the second cylindrical member 14 c by the fixing ring 17.

  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 along the central axis A, the actuator 10 extends, and when the piston unit 12 moves in the second movement direction W2 along the central axis A, the actuator 10 contracts. A contracted actuator 10 is shown in FIG. The actuator 10 operates by supplying and discharging pressure oil to the hydraulic chamber 19a and the hydraulic chamber 19b. When the actuator 10 is actuated, the piston 13 is displaced in the cylinder 11, whereby the moving blade 1A is driven through the piston rod 14 and the clevis 15.

  The piston unit 12 illustrated and described herein is an example, and the shapes, arrangements, and joining aspects of the components of the piston unit 12 are not limited to the aspects explicitly described herein. For example, in the piston unit 12, the piston rod 14 and the clevis 15 may be formed as one member.

  Inside the first cylindrical member 14 a of the piston rod 14, a differential transformer 20 for detecting the position of the piston unit 12 is provided. The differential transformer 20 includes a cylindrical housing 20a, and accommodates various components described later in the housing 20a. The housing 20a is fixed to the first cylinder member 11a at one end thereof. A power cable 28 is drawn out of the housing 11 from the differential transformer 20. Details of the differential transformer 20 will be described later.

  As shown in FIG. 1, 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 a first hydraulic chamber 19a of the hydraulic actuator 11 by an oil passage 8a, and connected to a second hydraulic chamber 19b of the hydraulic actuator 11 by an 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 19a via the first port 18a, and the oil passage 8b communicates with the second hydraulic chamber 19b 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 19a, 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 19a and discharges the oil from the second hydraulic chamber 19b, and discharges oil from the first hydraulic chamber 19a to the second hydraulic chamber 19b. 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 hydraulic chambers 19a and 15b and the discharge of oil from the hydraulic chambers 19a and 15b.

  The flight controller 5 identifies the position of the piston unit 12 based on the detection signal from the position detection mechanism 20, and based on the identified position of the piston unit 12, the position of the moving wing 1A corresponds to the flight state of the aircraft Feedback control can be performed to achieve the target position.

  Next, with further reference to FIG. 3, the differential transformer 20 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 differential transformer 20 in an enlarged manner. In FIG. 3, the illustration of the housing 20a is omitted.

  In the illustrated embodiment, differential transformer 20 is a linear variable differential transformer (LVDT). The differential transformer 20 includes an inner case 22a, an outer case 22b, a primary coil 23a, a pair of secondary coils 23b and 23c, a probe 24, and a core 25.

  The outer case 22b has a first outer case 22b1 and a second outer case 22b2. The first outer case 22b1 and the second outer case 22b2 are both formed in a cylindrical shape. The second outer case 22b2 is provided inside the first outer case 22b1. The inner case 22a has a base 22a1 closing one open end of the first outer case 22b1, and a cylindrical cylindrical portion 22a2 extending in the central axis A direction from the base 22a1. Since one open end of the first outer case 22b1 is closed by the base 22a1 of the inner case 22a, the differential transformer 20 has a bottomed cylindrical shape.

  The primary coil 23a and the secondary coils 23b and 23c are respectively held between the inner case 22a and the outer case 22b. These coils are disposed in the order of the secondary coil 23b, the primary coil 23a, and the secondary coil 23c from the bottom of the differential transformer 20 along the central axis A toward the opening.

  The primary coil 23a is excited by an AC input voltage. The secondary coils 23 b and 23 c are magnetically coupled to the primary coil 23 a via the core 25. Therefore, when the primary coil 23a is excited, an induced voltage is generated in the secondary coils 23b and 23c.

  The probe 24 has a rod-like probe main body 24 a extending along the central axis A, and a fixed shaft portion 24 b provided at one end of the probe 24 a. The probe 24 is fixed to the piston rod 14 at the fixed shaft portion 24 b. Specifically, an external thread is formed on the outer surface of the fixed shaft portion 24b, and the fixed shaft portion 24b is screwed to the solid portion 14b of the piston rod 14 as shown in FIG. Thus, the probe 24 is fixed to the piston rod 14. The probe 24 is configured and arranged to be displaced integrally with the piston unit 12.

  The core 25 is formed in a cylindrical shape and is fixed to the tip of the probe 24. The core 25 is constructed and arranged to be displaced integrally with the probe 24. The core 25 is made of, for example, permalloy, electromagnetic soft iron, or a material other than these.

  In the differential transformer 20, when the core 25 moves along the central axis A according to the displacement of the piston unit 12, the core 25 moves with respect to the primary coil 23a and the secondary coils 23b and 23c. When the position of the core 25 with respect to the primary coil 23a and the secondary coils 23b and 23c changes when the primary coil 23a is excited, the difference between the induced voltage generated in the secondary coil 23b and the induced voltage generated in the secondary coil 23c Since a certain differential voltage changes, the position relative to the reference position of the core is detected based on this differential voltage. The reference position of the core is the position of the core at the null point where the differential voltage is zero. The core 25 moves integrally with the piston unit 12 so that the position of the piston unit 12 can be detected based on the differential voltage. The differential voltage is output to the flight controller 5 or other information processing unit

  The differential transformer 20 specifically described in the present specification is an example, and the shapes, arrangements, and junction modes of components of the differential transformer 20 are the aspects explicitly described in the present specification. It is not limited to For example, the probe 24 may be joined to the piston rod 14 in a manner other than screwing. Also, the probe 24 is attached to the piston unit 12 in any manner as long as the probe 24 and the core 25 can move integrally with the piston unit 12.

  Next, a closed loop structure for detecting breakage or deterioration of the differential transformer and a sensor unit for detecting a physical change in the closed loop structure will be described. The actuator 10 is provided with a closed loop structure 50 having a closed loop structure. The closed loop structure 50 is at least partially provided inside the differential transformer 20.

  The closed loop structure 50 is provided with a sensor unit 30 that detects a physical change in the closed loop structure 50. The physical quantities detected by the sensor unit 30 change in response to physical changes in the closed loop structure 50. The physical quantity detected by the sensor unit 30 is any physical quantity that changes before and after the occurrence of breakage or deterioration when the closed loop structural body 50 is broken or deteriorated. For example, the sensor unit 30 can detect a physical quantity related to the current or magnetic flux flowing through the closed loop structure 50. The physical quantity related to the current flowing through the closed loop structure 50 is, for example, the current value of the current flowing through the closed loop structure 50 when a predetermined voltage is applied to the closed loop structure 50. The physical quantity related to the magnetic flux flowing through the closed loop structure 50 is, for example, the flux of leakage flux leaking from the closed loop structure 50.

  The closed loop structure in one embodiment of the present invention will be further described with further reference to FIGS. 4a and 4b. FIG. 4a schematically shows a cross section of a probe and core provided in a differential transformer according to an embodiment of the present invention and a sensor unit, and FIG. 4b is a sectional view taken along line I-I of FIG. 4a. It is a sectional view showing typically the section taken along.

  As shown, the closed loop structure 50 provided in the actuator 10 includes a wire 27 excellent in conductivity, a power supply 31 connected to the wire 27, an LED lamp provided in series with the power supply 31, etc. The lamp 32 is provided. In the illustrated embodiment, sensor unit 30 includes a power supply 31 and a lamp 32. The sensor unit 30 is provided on the actuator 10 so as to be able to move integrally with the piston unit 12. By providing the sensor unit 30 so as to be able to move integrally with the piston unit 12, the length of the wire 27 can be shortened compared to the case where the sensor unit 30 is provided in the cylinder 11.

  In the closed loop structure 50, the voltage applied from the power supply 31 causes a current to flow through the wire 27 and the lamp 32, and the lamp 32 is lit. Thus, an electrically closed circuit is configured along the closed loop structure of the closed loop structure 50. If the wire 27 breaks, the electrically closed circuit in the closed loop structure 50 is opened, and no current flows through the wire 27 and the lamp 32, so the lamp 32 is turned off.

  Thus, the lamp 32 constitutes a part of the closed loop structure 50 and also functions as a component of the sensor unit 30 for detecting the presence or absence of breakage of the closed loop structure 50.

  In the illustrated embodiment, the probe 24 and core 25 are formed with a hole structure 26 for inserting the wire 27 therethrough. The hole structure 26 includes a first through hole 26a, a second through hole 26b, a third through hole 26c, a fourth through hole 26d, and a fifth through hole 26e. The first through holes 26 a and the second through holes 26 b are formed in the probe 24. Each of the first through holes 26 a and the second through holes 26 b extends along the central axis A from one end of the probe 24 to the other end. The third through hole 26 c and the fourth through hole 26 d are formed in the core 25. The third through holes 26 c and the fourth through holes 26 d both extend along the central axis A from one end of the core 25 to the other end. The third through hole 26c is formed to be in communication with the first through hole 26a, and the fourth through hole 26d is formed to be in communication with the second through hole 26b. Further, the third through hole 26 c and the fourth through hole 26 d are connected by a fifth through hole 26 e extending in a direction perpendicular to the central axis A.

  The third through hole 26c, the fourth through hole 26d, and the fifth through hole 26e are divided in half along the central axis A along the central axis A of the cylindrical body to be the core 25, as shown in FIG. 4b. Prepare the half members 25a and 25b, and form the grooves corresponding to the third through holes 26c, the fourth through holes 26d, and the fifth through holes 26e on the joint surfaces of the half members 25a and 25b, respectively. It forms by joining the said half members 25a and 25b mutually after forming. Similarly to this, the first through holes 26a and the second through holes 26b are formed by forming grooves in a half-split member in which a cylindrical element body to be the probe 24 is split along the central axis A, It is formed by joining the half members.

  A portion of the wire 27 passes through the first through hole 26a, the third through hole 26c, the fifth through hole 26e, the fourth through hole 26d, and the second through hole 26b in the probe 24 and the core 25. It is arranged. The portion of the wire 27 outside the probe 24 and the core 25 enters the second cylindrical member 14c of the piston rod 14 from the end of the fixed shaft 24b, as shown in FIG. It is guided along the central axis A in the cylindrical member 14c and then pulled out of the gap between the second cylinder member 11b and the fixing ring 17 to the outside of the cylinder 11, and the sensor unit 30 ( Specifically, it is connected to the power supply 31 and the lamp 32).

  In the above embodiment, a portion of the wire 27 is disposed within both the probe 24 and the core 25, but a portion of the wire 27 is disposed within at least one of the probe 24 and the core 25. Good. In order to prevent the current flowing through the wire 27 from leaking out, at least a portion of the probe 24 and the core 25 in contact with the wire 27 is formed of an insulating material having excellent insulation. Further, a portion of the second cylinder member 11 b in contact with the wire 27 is also formed of an insulating material.

  The wire 27 described in the present specification is an example, and the shape of the wire 27, the arrangement in the actuator 10, and the connection aspect with the sensor unit 30 are not limited to the aspect explicitly described in the present specification. .

  The sensor unit 30 described herein is exemplary, and the arrangement of the sensor unit 30, the constituent members, and the detection principle of the physical change of the closed loop structure are the embodiments explicitly described herein. Is not limited.

  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. At this time, the core 25 is at the reference position where the differential voltage is zero.

  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 the oil to the first hydraulic chamber 19a and the second hydraulic chamber 19b. 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 core 25 also moves in the moving direction W2 according to the movement of the piston unit 12. Thereby, the core 25 moves in the direction approaching the secondary coil 23b from the reference position. As a result, the generated differential voltage is output to the flight controller 5.

  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 19 b and discharge the oil from the first hydraulic chamber 19 a. Thus, the piston unit 12 moves in the first movement direction W1.

  When the piston unit 12 starts moving in the first moving direction W1, the core 25 also moves in the moving direction W1 according to the movement of the piston unit 12. Thereby, the core 25 moves in the direction approaching the secondary coil 23c. As a result, the generated differential voltage is output to the flight controller 5.

  The flight controller 5 identifies the position of the piston unit 12 based on the differential voltage, and feedback control of the actuator 10 is performed based on the identified position of the piston unit 12.

  As described above, when the actuator 10 is actuated, the probe 24 and the core 25 move in the piston rod 14. The probe 24 and the core 25 may completely or partially break due to seizure with other members, stress corrosion cracking, or other causes.

  According to the above embodiment, at least a part of the closed loop structure 50 is provided inside at least one of the probe 24 and the core 25, and the sensor unit 30 detects a physical change in the closed loop structure 50. Therefore, if a break occurs in the probe 24 or the core 25, the sensor unit 30 can detect a physical change that occurs in the closed loop structure 50 due to the break. Specifically, when breakage or deterioration occurs to the extent that the electrical closed circuit in the closed loop structure 50 is opened in the probe 24 or the core 25, a voltage is applied by the power supply 31 in the sensor unit 30. However, since the lamp 32 does not light, the sensor unit 30 can detect breakage or deterioration of the probe 24 or the core 25.

  According to the above embodiment, since the wire 27 constituting the closed loop structure 50 is provided in the hole structure 26 formed in at least one of the probe 24 and the core 25, the operation of the differential transformer 20 is impaired. It does not take.

  Another embodiment of the invention will be described with reference to FIGS. 5a and 5b. Fig. 5a schematically shows a cross section of a probe and core provided in a differential transformer according to another embodiment of the present invention and a sensor unit, and Fig. 5b shows a II-II line of Fig. 5a. It is sectional drawing which shows typically the cross section which followed. In the embodiment shown in FIGS. 5a and 5b, a core 125 is provided instead of the core 25 in the embodiment of FIGS. 4a and 4b.

  The core 125 has a first portion 125 a connected to the probe 24 and a second portion 125 b connected to the first portion. The first portion 125a and the second portion 125b are integrally formed. The second portion 125 b is disposed farther from the fixed shaft portion 24 b than the first portion 125 a.

  A core first through hole 126 a and a core second through hole 126 b are formed in the first portion 125 a of the core 125. Each of the core first through hole 126 a and the core second through hole 126 b extends along the central axis A from one end to the other end of the first portion 125 a of the core 125. The core first through holes 126 a communicate with the first through holes 26 a formed in the probe 24, and the core second through holes 126 b communicate with the second through holes 26 b formed in the probe 24. The core first through hole 126a may be formed to have the same inner diameter as the first through hole 26a, and the core second through hole 126b may be formed to have the same inner diameter as the second through hole 26b. Good.

  A core third through hole 127a, a core fourth through hole 127b, and a core fifth through hole 127c for connecting the core third through hole 127a and the core fourth through hole 127b are provided in the second portion 125b of the core 125. It is formed. Each of the core third through hole 127 a and the core fourth through hole 127 b extends along the central axis A from one end of the second portion 125 b of the core 125 to the other end. The core third through hole 127a is in communication with the core first through hole 126a, and the core fourth through hole 127n is in communication with the core second through hole 126b.

  Core third through hole 127a is formed to have an inner diameter smaller than core first through hole 126a, and core fourth through hole 127b is formed to have an inner diameter smaller than core second through hole 126b. . The inner diameter of the core third through hole 127a is smaller than the inner diameter of the core first through hole 126a, and the inner diameter of the core fourth through hole 127b is smaller than the inner diameter of the core second through hole 126b. A step is generated at the boundary with the second portion 125b. Similarly to this, the core fourth through hole 127 b is formed to have an inner diameter smaller than that of the core second through hole 126 b.

  According to the above-described embodiment, the water accumulated at the bottom of the bottomed differential transformer 20 is formed on the boundary between the third core through hole 127a and the first core through hole 126a, and the fourth core The trapped water is trapped by the step formed at the boundary between the through hole 127b and the core first through hole 126b, and the trapped water is moved to the outside of the differential transformer 20 by the movement of the probe 24 and the core 125 in the first movement direction W1. Can be discharged.

  In yet another embodiment of the present invention, by forming a portion of the first through hole 26a formed in the probe 24 at a position distal to the fixed shaft portion 24b to a small diameter, the principle similar to the above is obtained. Water accumulated at the bottom of the differential transformer 20 can be discharged to the outside of the differential transformer 20.

  Next, still another embodiment of the present invention will be described with reference to FIGS. 6a and 6b. Fig. 6a schematically shows a cross section of a probe and core provided in a differential transformer according to another embodiment of the present invention and a sensor unit, and Fig. 6b shows a line III-III in Fig. 6a. It is sectional drawing which shows typically the cross section which followed. In the embodiment shown in FIGS. 6a and 6b, a probe 224 is provided instead of the probe 24 in the embodiment of FIGS. 4a and 4b and a core 225 is provided instead of the core 25.

  The outer surface of the probe 224 is formed with a first probe groove 226a and a second probe groove 226b. Each of the probe first groove 226 a and the probe second groove 226 b extends along the central axis A. Each of the probe first groove 226a and the probe second groove 226b is formed in a V-shaped cross section.

  In the outer surface of the core 225, a core first groove 227a and a core second groove 227b are formed. Each of the core first groove 227 a and the core second groove 227 b extends along the central axis A. As shown in FIG. 6b, the core first groove 227a and the core second groove 227b are both formed in a V-shaped cross section. The core 225 is formed with a connection hole 228 which connects the bottom of the core first groove 227a and the bottom of the core second groove 227b.

  The wire 27 is arranged such that a portion thereof passes through the probe first groove 226a, the core first groove 227a, the connection hole 228, the core second groove 227b, and the probe second groove 226b.

  According to this embodiment, the sensor unit 30 can detect breakage or deterioration of the probe 24 or the core 25 on the same principle as the above embodiment. In addition, since the wire 27 constituting the closed loop structure 50 is provided in the groove formed in the probe 224 and the core 225, it does not disturb the operation of the differential transformer 20.

  Next, still another embodiment of the present invention will be described with reference to FIGS. 7a and 7b. Fig. 7a schematically shows a cross section of a probe and core provided in a differential transformer according to another embodiment of the present invention and a sensor unit, and Fig. 7b shows a line IV-IV of Fig. 7a. It is sectional drawing which shows typically the cross section which followed. In the embodiment shown in FIGS. 7a and 7b, a core 325 is provided instead of the core 225 in the embodiment of FIGS. 6a and 6b.

  The core 325 has a first portion 325 a connected to the probe 224 and a second portion 325 b connected to the first portion on the opposite side of the probe 224. The second portion 325b is disposed more distally than the fixed shaft portion 24b than the first portion 325a.

  A core first groove 327 a and a core second groove 327 b are formed in the first portion 325 a of the core 325. Each of the core first groove 327a and the core second groove 327b extends along the central axis A from one end of the first portion 325a of the core 325 to the other end.

  A core third groove 329a, a core fourth groove 329b, and a communication hole 328 connecting the core third groove 329a and the core fourth groove 329b are formed in the second portion 325b of the core 325. Each of the core third groove 329 a and the core fourth groove 329 b extends along the central axis A from one end of the second portion 325 b of the core 325 to the other end.

  The core third groove 329a is shallower than the core first groove 327a, and the core fourth groove 329b is shallower than the core second groove 327b. Thus, a step is formed at the boundary between the first portion 325 a and the second portion 325 b of the core 325.

  According to the above embodiment, the water accumulated at the bottom of the bottomed differential transformer 20 is trapped by the step in the boundary between the first portion 325 a and the second portion 325 b of the core 325, and the trapped water Can be discharged to the outside of the differential transformer 20 by the movement of the probe 24 and the core 325 in the first movement direction W1.

  In still another embodiment of the present invention, in each of the probe first groove 226a and the probe second groove 226b formed in the probe 224, the portion distal to the fixed shaft portion 24b is formed in a small diameter. The water accumulated at the bottom of the differential transformer 20 can be discharged to the outside of the differential transformer 20 according to the same principle as described above.

  The groove in which the wire 27 is disposed may not have a V-shaped cross section, but may have a flat bottom as shown in FIGS. 8 and 9.

  FIG. 8 shows a variant of the embodiment shown in FIG. In the embodiment shown in FIG. 8, a core 425 is provided instead of the core 225 shown in FIG. In the core 425 of FIG. 8, a core first groove 427a is formed instead of the core first groove 227a, and a core second groove 427b is formed instead of the core second groove 227b. The bottoms of the core first groove 427a and the core second groove 427b are each formed flat.

  FIG. 9 shows a variant of the embodiment shown in FIG. In the embodiment shown in FIG. 9, a core 525 is provided instead of the core 325 shown in FIG. Instead of the core first groove 327a, the core second groove 327b, the core third groove 329a, and the core fourth groove 329b in the core 525 of FIG. 9, the core first groove 527a and the core second groove 527b are used. The third core groove 529a and the fourth core groove 529b are formed. The bottoms of the core first groove 527a, the core second groove 527b, the core third groove 529a, and the core fourth groove 529b are all formed flat.

  Similarly, the groove for receiving the wire 27 formed on the outer surface of the probe 224 may also be shaped to have a flat bottom, as shown in FIGS. 8 and 9.

  Next, still another embodiment of the present invention will be described with reference to FIG. FIG. 10 is a view schematically showing a cross section of a probe and a core provided in a differential transformer according to another embodiment of the present invention. In the embodiment shown in FIG. 10, a probe 624 is provided instead of the probe 224 in the embodiment of FIGS. 7a and 7b, and a core 625 is provided instead of the core 225.

  As shown, a spiral shaped probe groove 624a is formed doubly on the outer surface of the probe 624, and a spiral shaped core groove 625a is formed on the outer surface of the core 625. . As illustrated, the probe groove 624 a and the core groove 625 a are formed in a helical shape which is wound around the central axis A and translated in the direction of the central axis A.

  A wire 127 made of a conductive material is provided in the probe groove 624a and the core groove 625a. The wire 127 extends in the direction of the core 625 in one spiral path of the probe groove 624a which is a double helix, and then the tip of the core 625 in one spiral path of the core groove 625a which is a double helix. And is folded back at the tip of the core groove 625a. The wire 127 is folded back at the tip of the core groove 625a, and then extends toward the probe 624 in the other spiral path of the core groove 625a, and then the base of the probe 624 in the other spiral path of the probe groove 624a. Stretch towards the end. A closed circuit structure is formed by pulling out both ends of the wire 127 arranged in this way and connecting it to the sensor unit 30.

  According to the embodiment shown in FIG. 10, the probe 624 and the core 625 can be reinforced by the wire 127 in a helical shape.

  Next, a modification of the sensor unit will be described. As noted above, the sensor unit 30 is configured to detect physical changes in the closed loop structure 50 or other closed loop structures applied to the present invention. One modification of the sensor unit 30 is shown in FIG. FIG. 11 is a block diagram illustrating a sensor unit 30 according to another embodiment of the present invention.

  The sensor unit 30 in the embodiment shown in FIG. 11 includes a current sensor 33 connected in series with the power supply 31, a controller 34, and a lamp 32 such as an LED lamp.

  The current sensor 33 is configured to detect the current value of the current flowing through the wire 27 and to output the detected current value to the controller 34.

  The controller 34 communicates with the CPU for performing various arithmetic processing, the memory for storing various programs and various data, the current sensor 33, the lamp 32, and the device interface connected to other devices, and the external device 40. And a communication interface for performing.

  In one embodiment, controller 34 may be configured to be able to identify that at least one of breakage and deterioration has occurred in closed loop structure 50 based on the current value from current sensor 33. The controller 34 is configured, for example, to determine that the closed loop structure 50 has a break or deterioration when the current value from the current sensor 33 becomes lower than a predetermined lower limit value. Since the current flowing through the wire 27 is zero when the closed loop structure 50 is opened, the controller 34 determines that the closed loop structure 50 is opened when the current value from the current sensor 33 becomes zero. May be configured.

  The controller 34 may be configured to turn on or blink the lamp 32 when it determines that the closed loop structure 50 is broken or degraded. The lamp 32 is normally on and may be configured to be extinguished under the control of the controller 34 when the closed loop structure 50 is broken or deteriorated.

  The controller 34 can transmit various data to the external device 40 via the communication interface. For example, the controller 34 can transmit to the external device 40 a signal generated in response to the current value from the current sensor 33 or other physical change of the closed loop structure 50. The signals generated in response to physical changes in the closed loop structure 50 may be signals indicating various physical quantities that represent the physical state of the closed loop structure 50 detected by various sensors other than the current sensor 33. . The communication link between the controller 34 and the external device 40 may be a wireless link or a wired link. The controller 34 may be configured to transmit an anomaly detection signal to the external device 40 when it determines that the closed loop structure 50 is broken or deteriorated. The abnormality detection signal is a signal indicating that the closed loop structure 50 has been broken or deteriorated.

  The operator can use the data received from the controller 34 in the external device 40 to monitor breakage or deterioration of the differential transformer 20.

  Next, with reference to FIGS. 12a and 12b, an embodiment in which a physical quantity related to the magnetic flux flowing in the closed loop structure is detected in the sensor unit 30 will be described. 12a is a schematic cross-sectional view of a probe and a core provided in a differential transformer according to another embodiment of the present invention, and FIG. 12b schematically shows a cross-section along line VV of FIG. 12a. FIG. The differential transformer in the illustrated embodiment comprises a probe 724, a core 725, and a closed loop structure 150 partially provided inside the probe 724 and the core 725.

  As shown, in the probe 724 and the core 725, a part of the closed loop structure 150 made of a magnetic material is embedded. The closed loop structure 150 may be entirely embedded within at least one of the probe 724 and the core 725. The closed loop structure 150 is a structure made of a magnetic material and is formed to have a closed loop structure. In order to form a closed magnetic path along the closed loop structure 150, at least a portion of the probe 724 and the core 725 in contact with the closed loop structure 150 is formed of nonmagnetic material.

  A coil 37 is wound around the closed loop structure 150. A power supply 36 is connected to the coil 37. The coil 37 is configured to be excited by an alternating voltage applied from the power supply 36. The magnetic flux generated from the excited coil 37 passes through a closed magnetic path formed along the closed loop structure 150.

  The sensor unit 30 in the present embodiment includes a magnetic sensor 38 and a controller 34. Magnetic sensor 38 is configured to detect leakage flux from closed loop structure 150. The magnetic sensor 38 is, for example, a Hall element. The detected value of the magnetic sensor 38 is output to the controller 34.

  The controller 34 may be configured to determine that breakage or deterioration has occurred in the closed loop structure 150 when the detected value from the magnetic sensor 38 becomes higher than a predetermined upper limit value. When the closed loop structure 150 is broken or deteriorated, the magnetic resistance of the closed loop structure 150 is increased, so that the leakage of the magnetic flux from the closed loop structure 150 to the outside tends to occur. Since the detection value of the magnetic sensor 38 indicates the leakage flux from the closed loop structure 150 or the magnetic flux density thereof, the controller 34 causes the closed loop structure 150 to be detected when the detection value of the magnetic sensor 38 becomes higher than the upper limit. It can be determined that breakage or deterioration has occurred.

  The sensor unit 30 may comprise a lamp. The controller 34 may be configured to turn on, turn off, or blink the lamp when it determines that the closed loop structure 150 is broken or deteriorated.

  The controller 34 may be configured to transmit the detection value of the magnetic sensor 38 to the external device 40. The controller 34 may be configured to transmit an anomaly detection signal to the external device 40 when it determines that the closed loop structure 150 is broken or deteriorated.

  In one embodiment of the present invention, the closed loop structure 50 may be formed of a material that is tougher than the probe 24, the probe 224, and the probe 624. The closed loop structure 150 may be formed of a material that is tougher than the probe 724. The closed loop structure 50 may be formed of a material that is tougher than the core 25, the core 125, the core 225, the core 325, the core 425, the core 525, and the core 625. The closed loop structure 150 may be formed of a material that is tougher than the core 725. Thus, by forming the closed loop structure 50 and the closed loop structure 150 from a material of high toughness, it is possible to provide structural redundancy to each probe and each core, so that each probe and each core is less likely to break. Become.

  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.

  For example, the specific shapes and arrangements of the components of the actuator 10 and differential transformer 20 explicitly described herein are exemplary. The shapes, arrangements, and functions of the components of the actuator 10 and the differential transformer 20 may be changed as appropriate, as long as not departing from the spirit of the present invention.

  Some of the control and operations performed by the controller 34 may be performed by at least one of the flight controller 5 and the actuator controller 6. Some or all of the control and operations performed by the controller 34 may be distributed and executed by a plurality of controllers provided in the system 1 or external to the system 1.

  The physical quantities detected by the sensor unit 30 are not limited to those explicitly mentioned in the present specification. For example, the physical quantities detected by the sensor unit 30 include the electrical resistance, the electrical capacitance, the magnetoresistance, and the other of the closed loop structure 50, the closed loop structure 150, or any other closed loop structure applicable to the present invention. It may include any physical quantity that changes before or after the break or deterioration occurs when the closed loop structure 50 is broken or deteriorated.

REFERENCE SIGNS LIST 10 actuator 11 cylinder 12 piston unit 20 differential transformer 24, 224, 624, 724 probe 25, 125, 225, 325, 425, 525, 625, 725 core 27, 127 wire 30, 130 sensor unit 31, 36 power supply 32 Lamp 33 current sensor 37 coil 38 magnetic sensor 40 external device 50, 150 closed loop structure 125a, 325a first portion 125b, 325b second portion 126a core first through hole 126b core second through hole 127a core third through hole 127b core Fourth through hole 226a Probe first groove 226b Probe second groove 227a, 327a, 427a, 527a Core first groove 227b, 327b, 427b, 527b Core second groove 325a First portion 325b Second portion 329a, 29a Core third groove 329b, 529b core fourth grooves 624a probes groove 625a core groove

Claims (16)

With the cylinder,
A piston unit slidably provided in the cylinder;
A differential transformer for detecting the position of the piston unit relative to the cylinder;
A closed loop structure at least partially provided in the differential transformer;
A sensor unit for detecting a physical change in the closed loop structure;
An actuator comprising:   The actuator according to claim 1, wherein the sensor unit is configured to detect a physical quantity related to current or magnetic flux flowing through the closed loop structure.   The actuator according to claim 1, wherein the sensor unit is configured to detect that the closed loop structure has been opened.   The actuator according to claim 3, wherein the sensor unit is configured to detect that the closed loop structure is opened based on a current value of a current flowing through the closed loop structure. The closed loop structure is made of a magnetic material,
The sensor unit is configured to detect that the closed loop structure is opened by detecting a leakage flux from the closed loop structure.
The actuator according to claim 3. The differential transformer has a probe attached to the piston unit,
At least a portion of the closed loop structure is formed on the probe,
The actuator according to any one of claims 1 to 5.   The actuator according to claim 6, wherein the closed loop structure is made of a material having higher toughness than the probe. The differential transformer has a core provided to the probe,
At least a portion of the closed loop structure is formed on the probe and the core,
The actuator according to claim 6 or 7.   The actuator according to claim 8, wherein the closed loop structure is made of a material having higher toughness than the core. At least a portion of the closed loop structure is provided in a through hole formed in at least one of the probe and the core.
The actuator according to any one of claims 6 to 9. The through hole is formed to have a first hole portion having a first inner diameter and a second hole portion having a second inner diameter smaller than the first inner diameter.
The second hole portion is disposed more distally than the first hole portion from an attachment position at which the probe is attached to the piston unit.
The actuator according to claim 10. At least a portion of the closed loop structure is provided within a groove formed in at least one of the probe and the core.
The actuator according to any one of claims 6 to 11. The groove is formed to have a first groove portion having a first outer diameter and a second groove portion having a second outer diameter larger than the first outer diameter.
The second groove portion is disposed more distally than the first groove portion from an attachment position where the probe is attached to the piston unit.
The actuator according to claim 12.   The actuator according to claim 12, wherein the closed loop structure is formed in a helical shape on at least one of the probe and the core. The sensor unit further comprises a lamp that lights up, flashes or extinguishes in response to a physical change in the closed loop structure.
The actuator according to any one of claims 1 to 14. The sensor unit is configured to transmit the generated signal to an external device in response to a physical change in the closed loop structure.
The actuator according to any one of claims 1 to 17.

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