JP5214365B2 - Actuator device and power assist device - Google Patents

Description

  The present invention relates to an actuator device including an actuator that is driven when a fluid is supplied, and a power assist device equipped with the actuator device.

  For example, an actuator device that includes a fluid pressure cylinder such as a hydraulic cylinder, a pump that supplies fluid to the fluid pressure cylinder, and a motor that drives the pump is known as an actuator device that amplifies and outputs human force. (For example, refer to Patent Documents 1 to 3).

  FIG. 7 shows an example of such an actuator device. The actuator device 100 includes a hydraulic cylinder 101, a hydraulic pump 102, and a motor 103 that drives the hydraulic pump 102. The hydraulic cylinder 101 includes a cylinder body 101a and a piston rod 101b. The inside of the cylinder body 101a is partitioned into a first pressure chamber 111 and a second pressure chamber 112 by a piston rod 101b. The hydraulic pump 102 and the first pressure chamber 111 communicate with each other via a pipe line 104. The hydraulic pump 102 and the second pressure chamber 112 communicate with each other via a pipe line 105.

  The motor 103 can rotate in both directions. When the motor 103 rotates in the clockwise direction in FIG. 7, the oil in the first pressure chamber 111 is sucked into the hydraulic pump 102 through the conduit 104, while the oil is supplied from the hydraulic pump 102 to the second pressure chamber 112 through the conduit 105. Is supplied. As a result, the thrust of the second pressure chamber 112 (where thrust = pressure receiving area × pressure) is higher than the thrust of the first pressure chamber 111, and the piston rod 101b moves to the left and contracts. Conversely, when the motor 103 rotates counterclockwise in FIG. 7, the oil in the second pressure chamber 112 is sucked into the hydraulic pump 102 through the conduit 105, while the first pressure is supplied from the hydraulic pump 102 through the conduit 104. Oil is supplied to the chamber 111. As a result, the thrust of the first pressure chamber 111 becomes larger than the thrust of the second pressure chamber 112, and the piston rod 101b moves rightward and extends. In addition, the relationship between the rotation direction of the motor 103 and the movement direction of the piston rod 101b is not limited to the above relationship, and may be a relationship opposite to the above relationship. That is, when the motor 103 rotates in the clockwise direction, the piston rod 101b may move in the right direction. Conversely, when the motor 103 rotates in the counterclockwise direction, the piston rod 101b may move in the left direction.

  In the actuator device 100, the expansion / contraction speed of the piston rod 101 b is determined by the rotation speed of the hydraulic pump 102, and the rotation speed of the hydraulic pump 102 depends on the rotation speed of the motor 103. Therefore, the piston rod 101 b is controlled by controlling the motor 103.

By the way, for example, in a large device that tends to have large inertia or a device that performs an agile operation, some response delay occurs between the operation input from the person or the controller and the operation of the piston rod 101b. Alternatively, a situation may occur in which the piston rod 101b moves in the direction opposite to the direction instructed by the controller. In the actuator device 100, in such a case, the movement of the piston rod 101b is attenuated by controlling the motor 103. That is, the movement of the piston rod 101b is actively attenuated in software by adding a drive signal of a component that rotates in the opposite direction to the motor 103 by feedback of speed information or the like.
JP-A-1-247805 JP 7-110006 A JP 7-190003 A

  However, the above-described method may cause control instability. For example, even if a drive signal is added to the motor 103, instability may occur if there is a delay before the drive force of the piston rod 101b is actually generated. Next, such an unstable phenomenon will be described with reference to FIG.

  In FIG. 8, symbols V1, S1, and D1 represent the speed of the piston rod 101b, the drive signal added to the motor 103, and the drive force generated in the piston rod 101b, respectively. As shown in FIG. 8 (a), for example, when the person or the controller operates to stop this when the piston rod 101b is moving in the positive direction, the person or the controller outputs the drive signal S1 in the negative direction. This is added to the motor 103. Thereby, the piston rod 101b decelerates. However, as shown in FIG. 8B, when the speed V1 reaches 0 and the addition of the drive signal S1 is stopped, if a delay occurs, the drive force D1 in the negative direction of the piston rod 101b continues to be output. The piston rod 101b turns from the decelerated state to the acceleration in the negative direction (see the region DL1 in FIG. 8B). In response, the person or controller, in turn, adds a positive direction drive signal S1 to the motor 103, decelerates the speed in the negative direction, and accelerates until the speed becomes zero, but again the piston rod 101b. Due to the delay of the driving force, acceleration in the positive direction starts (see region DL2). By repeating this, an unstable vibration phenomenon may occur.

  The present invention has been made in view of this point, and an object of the present invention is to provide an actuator device having a function of attenuating the operation of the actuator and a function of suppressing the occurrence of a vibration phenomenon.

An actuator device according to the present invention includes an actuator that is driven when fluid is supplied, a pump that supplies fluid to the actuator, a conduit that connects the pump and the actuator, a motor that drives the pump, provided in the conduit, and freely stop mechanism switched between a non-aperture state which does not substantially reduce the flow rate of the fluid and the diaphragm state flow through the conduit to reduce the flow rate of the fluid flowing through the conduit, wherein A sensor for detecting the operation of the actuator, an operating device for operating the actuator via the pump by giving a command to the motor, a command given to the motor from the operating device, and an operation of the actuator And a control device for setting the diaphragm mechanism to the throttle state or the non-throttle state based on To have. The direction of the driving force that should be generated in the actuator when a positive command is given from the operating device is the positive direction, and the direction of the driving force that should be generated in the actuator when a negative command is given from the operating device. When the direction is the negative direction, the control device compares the sign of the command (hereinafter referred to as the initial command) that the operating device is giving with the sign of the speed of the actuator detected by the sensor. When the sign of the initial command and the speed of the actuator is different, the absolute value of the command actually given to the motor from the operating device is 0 or smaller than the absolute value of the initial command, When the aperture mechanism is set to the aperture state and the signs of the initial command and the speed of the actuator are the same, the initial command is It was actually given command from the device to the motor, to set the diaphragm mechanism to the non-stop state.

According to the actuator device described above, the throttle mechanism can exhibit a damping function that attenuates the operation of the actuator by reducing the flow rate of the fluid flowing through the pipe. Further, the diaphragm mechanism does not activate the actuator actively unlike the conventional technique in which the operation of the actuator is damped in software and actively by feedback of speed information by devising the control of the motor. Therefore, there is no risk that the actuator will vibrate if it is intended to attenuate. Therefore, the actuator can be damped without causing a vibration phenomenon. Further, according to the actuator device described above, when the signs of the initial command and the actuator speed are different, the absolute value of the command actually given to the motor from the operating device is 0 or smaller than the absolute value of the initial command. In addition, the flow rate of the oil flowing through the pipeline is reduced by setting the throttle mechanism to the throttle state. As a result, the operation of the actuator is attenuated, and the unstable operation is suppressed accordingly. On the other hand, when the signs of the initial command and the actuator speed are the same, the initial command is actually given to the motor from the operating device, and the throttle mechanism is set to the non-throttle state, so that The flow rate of the flowing oil is not substantially reduced. Thereby, with respect to the operation of the actuator, the same performance as in the case where there is no diaphragm mechanism can be obtained.

An actuator device according to the present invention includes an actuator that is driven when fluid is supplied, a pump that supplies fluid to the actuator, a conduit that connects the pump and the actuator, a motor that drives the pump, A throttling mechanism provided in the pipe and capable of switching between a throttling state in which the flow rate of the fluid flowing through the pipe is reduced and a non-throttling state in which the flow rate of the fluid flowing through the pipe is not substantially reduced; A sensor for detecting the operation of the actuator, an operating device for operating the actuator via the pump by giving a command to the motor, a command given to the motor from the operating device, and an operation of the actuator And a control device for setting the diaphragm mechanism to the throttle state or the non-throttle state based on To have. The control device determines whether or not the operation of the actuator is stable based on a command given to the motor from the operating device and the operation of the actuator. If the aperture state is not stable, the aperture mechanism is set to the aperture state.

According to the actuator device described above, the throttle mechanism can exhibit a damping function that attenuates the operation of the actuator by reducing the flow rate of the fluid flowing through the pipe. Further, the diaphragm mechanism does not activate the actuator actively unlike the conventional technique in which the operation of the actuator is damped in software and actively by feedback of speed information by devising the control of the motor. Therefore, there is no risk that the actuator will vibrate if it is intended to attenuate. Therefore, the actuator can be damped without causing a vibration phenomenon. Also, according to the actuator device, when the operation of the actuator is not stable, the throttle mechanism is set to the throttle state, whereby the flow rate of the oil flowing through the pipeline is reduced. As a result, the operation of the actuator is attenuated, and the unstable operation is suppressed accordingly. On the other hand, when the operation of the actuator is stable, the flow rate of oil flowing through the pipeline is not substantially reduced by setting the throttle mechanism to the non-throttle state. Thereby, with respect to the operation of the actuator, the same performance as in the case where there is no diaphragm mechanism can be obtained.

  The actuator includes a cylinder body, a fluid pressure having a cylinder body and a piston rod that divides the inside of the cylinder body into a first pressure chamber and a second pressure chamber and extends outside the cylinder body through the second pressure chamber. The cylinder includes a first pipe that communicates the pump and the first pressure chamber, and a second pipe that communicates the pump and the second pressure chamber. When the rod is extended, the fluid is supplied to the first conduit through which the fluid flows from the pump toward the first pressure chamber, and when the piston rod is contracted, the fluid flows from the pump toward the second pressure chamber. You may further provide the storage means which collect | recovers some fluids of a 2nd pipe line.

  This eliminates excess or deficiency of fluid in the pipe line, and smooth operation can be performed even when a so-called single rod type fluid pressure cylinder is used as the actuator.

  The aperture mechanism may be configured such that the aperture amount can be arbitrarily adjusted.

  Accordingly, for example, the operator can arbitrarily limit the aperture amount of the aperture mechanism, so that the operation speed of the actuator can be appropriately limited.

  A power assist device according to the present invention is equipped with the actuator device.

  ADVANTAGE OF THE INVENTION According to this invention, the actuator apparatus which has a function which attenuates the operation | movement of an actuator without vibrating can be implement | achieved.

<Embodiment 1>
FIG. 1 is a block diagram illustrating a configuration of an actuator device 1 according to the present embodiment. As shown in FIG. 1, the actuator device 1 includes a hydraulic cylinder 2 as an actuator, a hydraulic pump 3, and a motor 4 that drives the hydraulic pump 3. The hydraulic cylinder 2 has a cylinder body 2a and a piston rod 2b inserted into the cylinder body 2a. The inside of the cylinder body 2a is partitioned into a first pressure chamber 11 and a second pressure chamber 12 by a piston rod 2b. The piston rod 2b extends through the second pressure chamber 12 and out of the cylinder body 2a. The hydraulic cylinder 2 is a so-called single rod type hydraulic cylinder. The hydraulic pump 3 is rotatable in both directions, and performs an operation of discharging oil from one end 3a and sucking oil from the other end 3b, and an operation of sucking oil from the one end 3a and discharging oil from the other end 3b. It is feasible. The motor 4 is a bidirectionally rotatable motor and is connected to the hydraulic pump 3.

  One end 3 a of the hydraulic pump 3 communicates with the first pressure chamber 11 of the hydraulic cylinder 2 through the first pipe 5. On the other hand, the other end 3 b of the hydraulic pump 3 communicates with the second pressure chamber 12 of the hydraulic cylinder 2 via the second pipe 6. A first throttle mechanism 7 is provided in the first pipeline 5, and a second throttle mechanism 8 is provided in the second pipeline 6. The first throttle mechanism 7 is a mechanism capable of reducing the flow rate of oil flowing through the first pipeline 5, and the second throttle mechanism 8 is a mechanism capable of reducing the flow rate of oil flowing through the second pipeline 6. Further, the throttle mechanisms 7 and 8 can be set to a state in which the flow rate of oil flowing through the pipelines 5 and 6 is not substantially reduced. That is, the first throttling mechanism 7 and the second throttling mechanism 8 can be switched between a throttling state in which the oil flow rate is reduced and a non-throttle state in which the oil flow rate is not substantially reduced. The first diaphragm mechanism 7 and the second diaphragm mechanism 8 may be configured such that the diaphragm amount can be arbitrarily adjusted. The specific configurations of the first throttle mechanism 7 and the second throttle mechanism 8 are not limited at all. For example, as the first throttle mechanism 7 and the second throttle mechanism 8, a proportional electromagnetic flow rate adjusting valve, a proportional electromagnetic pressure reducing valve, or the like can be used. It can be used suitably.

  A tank 23 is connected between the hydraulic pump 3 and the first throttle mechanism 7 in the first pipeline 5 via a first pilot check valve 21. A tank 23 is connected between the hydraulic pump 3 and the second throttle mechanism 8 in the second pipeline 6 via a second pilot check valve 22. When the single rod type hydraulic cylinder 2 and the hydraulic pump 3 are connected by the first pipe line 5 and the second pipe line 6, excess or deficiency of oil corresponding to the volume difference of the rods of the hydraulic cylinder 2 occurs. Therefore, the tank 23 stores an amount of oil that can compensate for this.

  The actuator device 1 includes an operation device 14. The operation device 14 is a device operated by an operator or a controller. The specific configuration of the operating device 14 is not limited at all. For example, an operation lever or an operation handle can be suitably used as the operation device 14. Further, as the operation device 14, for example, a device that can input a control command from a personal computer or the like may be used.

  In addition, the actuator device 1 includes a control device 15. The control device 15 drives the motor 4 based on an operation input to the operation device 14. That is, when the operator operates the operation device 14 (in other words, when an operation input is given to the operation device 14), the control device 15 drives the motor 4 according to the operation input of the operation device 14, and the piston of the hydraulic cylinder 2 The rod 2b is expanded and contracted.

  When the motor 4 rotates in the clockwise direction in FIG. 1, oil is sucked from one end 3a of the hydraulic pump 3, and oil is discharged from the other end 3b. Then, the oil in the first pressure chamber 11 of the hydraulic cylinder 2 flows out of the first pressure chamber 11 and flows into the hydraulic pump 3 through the first pipe 5. As a result, the hydraulic pressure in the first pressure chamber 11 decreases. On the other hand, the oil discharged from the other end 3 b of the hydraulic pump 3 flows into the second pressure chamber 12 through the second pipe 6. As a result, the hydraulic pressure in the second pressure chamber 12 increases. Thereby, the thrust of the 2nd pressure chamber 12 becomes larger than the thrust of the 1st pressure chamber 11, and the piston rod 2b moves to the left side of FIG. 1 by the thrust difference. That is, the piston rod 2b contracts. At this time, the first pilot check valve 21 is opened by the pilot pressure introduced from the second pipe 6, and excess oil is discharged to the tank 23.

  On the other hand, when the motor 4 rotates counterclockwise in FIG. 1, oil is discharged from one end 3a of the hydraulic pump 3 and oil is sucked from the other end 3b. Then, the oil in the second pressure chamber 12 of the hydraulic cylinder 2 flows out of the second pressure chamber 12 and flows into the hydraulic pump 3 through the second pipe 6. as a result. The hydraulic pressure in the second pressure chamber 12 decreases. On the other hand, the oil discharged from the one end 3 a of the hydraulic pump 3 flows into the first pressure chamber 11 through the first pipe 5. As a result, the hydraulic pressure in the first pressure chamber 11 increases. Thereby, the thrust of the 1st pressure chamber 11 becomes larger than the thrust of the 2nd pressure chamber 12, and the piston rod 2b moves to the right side of FIG. 1 by the thrust difference. That is, the piston rod 2b extends. At this time, the second pilot check valve 22 is opened by the pilot pressure introduced from the first pipe 5, and the oil in the tank 23 is supplied to the second pipe 6.

  In the present embodiment, the actuator device 1 includes a sensor 16 that detects the expansion / contraction operation of the piston rod 2b. The sensor 16 can detect how much the piston rod 2b contracts or how much it extends. The specific configuration of the sensor 16 is not limited at all. For example, the sensor 16 may be a position sensor that detects the position of the tip of the piston rod 2b. Then, the position information obtained by the sensor 16 may be calculated by the control device 15 as the piston rod speed.

  In the present embodiment, the control device 15 determines whether or not the operation of the hydraulic cylinder 2 is stable based on the operation input to the operation device 14 and the operation of the piston rod 2b. Here, stable means that the cylinder 2 is operating as intended by the operator or controller. Conversely, unstable means that the cylinder 2 operates unintended by the operator or controller. Say that state.

  When the operation of the hydraulic cylinder 2 is stable, the control device 15 sets the first throttle mechanism 7 and the second throttle mechanism 8 to the non-throttle state. For example, when the 1st throttle mechanism 7 and the 2nd throttle mechanism 8 are comprised by the flow regulating valve, those valves are set to a full open state. On the other hand, the control device 15 sets the first throttle mechanism 7 or the second throttle mechanism 8 to the throttle state when the operation of the hydraulic cylinder 2 is not stable. For example, when the first throttling mechanism 7 and the second throttling mechanism 8 are configured by flow rate adjusting valves, at least one of the valves is throttled to a predetermined opening, and the first pipe line 5, the second pipe line 6, or both Reduce the flow rate of oil flowing through. As a result, the thrust difference between the first pressure chamber 11 and the second pressure chamber 12 of the hydraulic cylinder 2 changes gently. As a result, the first throttle mechanism 7 or the second throttle mechanism 8 functions as a so-called damper, and the contraction operation or extension operation of the piston rod 2b becomes gentle. In addition, when narrowing down the 1st pipe line 5 and the 2nd pipe line 6 simultaneously, it is more preferable to employ | adopt a circuit structure as shown in FIG. In the circuit shown in FIG. 2, the passage having the check valve 25 is arranged in parallel with the throttle mechanisms 7 and 8.

  A method for determining whether or not the operation of the hydraulic cylinder 2 is stable is not limited in any way, but here, an example is provided in which a so-called virtual power monitor is provided and the stability of the operation is determined by the virtual power monitor. (See Japanese Patent No. 3809614).

  As shown in FIG. 3, the actuator device 1 according to the present embodiment is an actuator device of the power assist device 20 that amplifies and outputs a human force.

  In FIG. 3, symbol Kusr represents a force amplification factor (power assist gain). Symbol Uh represents an operating force (also referred to as an operation input) given by the operator, and symbol Uusr represents an amplified force. In the present embodiment, the motor 4 is controlled so that the piston rod 2b of the hydraulic cylinder 2 outputs the amplified force Uusr.

In the power assist device 20, the input / output of a control system (hereinafter simply referred to as a system) (here, the operator's operating force Uh is used as the system input and the output of the sensor 16 is used as the system output) is virtual. Observed by the power monitor 31, the stability of the system is evaluated by the virtual energy Ev calculated from the observation result Pv as shown in the following equation.

  When an unstable behavior (for example, Ev <0, etc., the criteria for determination of instability / stability is not limited to this, but may be arbitrarily determined according to system characteristics) is detected. In the embodiment, the first diaphragm mechanism 7 and the second diaphragm mechanism 8 are adjusted to reduce the movement of the piston rod 2b, thereby stabilizing the system. The stability is evaluated based on the virtual energy Ev calculated from the observation result Pv, and the virtual power limiter 32 adjusts the weights Wv1 and Wv2 of the first diaphragm mechanism 7 and the second diaphragm mechanism 8 based on the virtual energy Ev. To do. That is, the degree of restriction of the first throttle mechanism 7 and the second throttle mechanism 8 (in other words, the flow rate of oil in the first pipe line 5 and the second pipe line 6) is adjusted.

  When the virtual power monitor 31 determines that the system is stable, the first throttling mechanism 7 and the second throttling mechanism 8 are set to a non-throttle state that does not substantially reduce the oil flow rate. For example, when the first throttling mechanism 7 and the second throttling mechanism 8 are proportional electromagnetic flow control valves, the fully throttled state is set. On the other hand, if it is determined by the virtual power monitor 31 that the system is not stable, the flow rate of the oil is throttled by the first throttle mechanism 7 and the second throttle mechanism according to the degree of stability. For example, when the first throttling mechanism 7 and the second throttling mechanism 8 are proportional electromagnetic flow rate adjusting valves, the respective opening amounts are set to reduce the oil flow rate.

  Also in the present embodiment, when the system is in a stable state, the first throttle mechanism 7 and the second throttle mechanism 8 are set to the non-throttle state, so that the piston rod 2b of the hydraulic cylinder 2 expands and contracts smoothly. On the other hand, when the system is in an unstable state, the first throttle mechanism 7 or the second throttle mechanism 8 can attenuate the operation of the piston rod 2b and suppress the occurrence of a vibration phenomenon.

  In the present embodiment, the virtual power monitor 31 detects whether or not the system is stable. Therefore, the stability of the system can be detected at a higher level.

<Embodiment 2>
In the first embodiment, the diaphragm mechanisms 7 and 8 are controlled based on whether the system is stable or not. However, the control of the diaphragm mechanisms 7 and 8 is not limited to that based on whether the system is stable or not. In the second embodiment, the throttle mechanisms 7 and 8 are controlled based on whether or not the sign of the command to be given by the operating device 14 (hereinafter referred to as the initial command) matches the speed of the piston rod 2b. It is.

  FIG. 4 is a control block diagram according to the present embodiment. Similar to the first embodiment, the actuator device 1 includes a hydraulic cylinder 2, a hydraulic pump 3, and a motor 4. A first throttle mechanism 7 is disposed in the first pipeline 5 that connects the hydraulic pump 3 and the first pressure chamber 11 of the hydraulic cylinder 2. A second throttle mechanism 8 is disposed in the second pipeline 6 that connects the hydraulic pump 3 and the second pressure chamber 12 of the hydraulic cylinder 2. In addition, the same code | symbol is attached | subjected to the part similar to Embodiment 1, and those description is abbreviate | omitted.

In the following description, the symbols y _d represent the operation input symbol Uusr represents a current command, namely initial instruction operating device 14 is about to give the motor 4. The symbol u represents a current command given to the motor 4 as a result of control by the determination unit 30, that is, a current command actually given to the motor 4. The symbol y represents the actuator speed. Symbol Wu represents the weight by the determination unit 30, symbol Wv1 represents the weight of the first diaphragm mechanism 7, and symbol Wv2 represents the weight of the second diaphragm mechanism 8.

  Whether or not the operation of the actuator is attenuated by the aperture mechanisms 7 and 8 is determined based on, for example, comparing the sign of the initial command Uusr and the sign of the actuator speed y and whether the signs are the same or different. Can do. Specifically, the determination unit 30 can determine that attenuation is not necessary when the codes are the same. If the signs are different, it can be determined that attenuation is necessary.

  FIG. 5 is a timing chart showing an example of control. In this example, when the initial command Uusr and the actuator speed y have the same sign, the weights Wu = 1 and Wv1 = Wv2 = 0. That is, when the signs of the initial command Uusr and the actuator speed y are the same, the initial command Uusr is set as a command that is actually given from the controller 14 to the motor 4 (u = Uusr). Further, the first diaphragm mechanism 7 and the second diaphragm mechanism 8 are set to the non-throttle state. On the other hand, if the initial command Uusr and the actuator speed y have different signs, the weight Wu = 0. That is, when the signs of the initial command Uusr and the actuator speed y are different, a signal for driving the motor 4 is not given (u = 0). Further, at least one of the first aperture mechanism 7 and the second aperture mechanism 8 is set to the aperture state. Specifically, the weight Wv1 of the first aperture mechanism 7 or the weight Wv2 of the second aperture mechanism 8 is set to a value commensurate with the initial command Uusr. That is, 0 <Wv1 ≦ 1 or 0 <Wv2 ≦ 1. Here, 1 represents the maximum aperture state.

  The first diaphragm mechanism 7 or the second diaphragm mechanism 8 may be configured to be able to change the diaphragm amount in an analog manner (in other words, continuously so that the diaphragm amount can be arbitrarily set). The aperture amount may be configured to be changed digitally (in other words, discontinuously so that the aperture amount can be set stepwise).

  As described above, according to the actuator device 1 according to the present embodiment, when the signs of the initial command and the speed of the hydraulic cylinder 2 do not match, the first throttle mechanism 7 or the second throttle mechanism 8 The flow rate of oil in the first pipeline 5 or the second pipeline 6 is reduced. Therefore, when the signs of the initial command and the speed of the hydraulic cylinder 2 do not match, the operation of the hydraulic cylinder 2 (strictly speaking, the expansion and contraction operation of the piston rod 2b) can be attenuated. Further, unlike the prior art in which the movement of the piston rod 2b is actively attenuated by software by devising the control of the motor 4, the first throttle mechanism 7 and the second throttle mechanism 8 actively move the piston rod 2b. It doesn't let you. Therefore, in principle, only the operation of damping the piston rod 2b is performed. Therefore, there is no acceleration in the opposite direction in an attempt to damp the operation of the hydraulic cylinder, which was a problem in the prior art. Therefore, according to the present embodiment, it is possible to obtain the actuator device 1 having a function of attenuating the operation and a function of suppressing the occurrence of the vibration phenomenon.

  Further, according to this embodiment, when the signs of the initial command and the speed of the hydraulic cylinder 2 match, the first throttle mechanism 7 and the second throttle mechanism 8 are set to the non-throttle state. . For this reason, when the signs of the initial command and the speed of the hydraulic cylinder 2 coincide with each other even though the first throttle mechanism 7 and the second throttle mechanism 8 are provided, the first pipeline 5 and the second throttle mechanism The flow resistance of oil in the two pipe lines 6 is suppressed. Therefore, the piston rod 2b can be extended and contracted smoothly. Further, the operation of the piston rod 2b is not unnecessarily attenuated.

  In the above embodiment, when the signs of the initial command Uusr and the actuator speed y are different, the weight Wu = 0 is set (see FIG. 5). However, as shown in FIG. 6, 0 <Wu <1 may be set when the signs of the initial command Uusr and the actuator speed y are different. That is, the absolute value of the command u actually given to the motor 4 from the operating device 14 may be a value larger than zero and smaller than the absolute value of the initial command Uusr. Thereby, energy saving can also be achieved. Also in this case, at least one of the first aperture mechanism 7 and the second aperture mechanism 8 is set to the aperture state.

<Modification>
In each of the above-described embodiments, when the first throttle mechanism 7 and the second throttle mechanism 8 are throttled, the internal pressures of the first pipeline 5 and the second pipeline 6 may increase, respectively. Therefore, the torque of the motor 4 may be regulated when the internal pressure of the first pipeline 5 or the second pipeline 6 is equal to or higher than a predetermined pressure. That is, the motor 4 may be provided with a torque limiter. Moreover, you may make it arrange | position the relief valve open | released in the 1st pipe line 5 and the 2nd pipe line 6 when it becomes more than predetermined pressure.

  In each of the above embodiments, the first throttle mechanism 7 is provided in the first pipeline 5, and the second throttle mechanism 8 is provided in the second pipeline 6. However, one of the first aperture mechanism 7 and the second aperture mechanism 8 can be omitted. That is, a throttle mechanism may be provided only between the hydraulic pump 3 and the first pressure chamber 11, or a throttle mechanism may be provided only between the hydraulic pump 3 and the second pressure chamber 12.

  In each of the embodiments described above, the hydraulic cylinder 2 is used as the actuator. However, the actuator according to the present invention may be a fluid pressure cylinder other than the hydraulic cylinder, for example, a hydraulic cylinder, an air cylinder, or the like. Further, an actuator other than the fluid pressure cylinder, such as a hydraulic motor, may be used.

  In each of the above-described embodiments, the single rod type hydraulic cylinder 2 is used as an actuator, and the first pipe line 5 and the second pipe line 6 are used to eliminate the excess and deficiency of oil accompanying the expansion and contraction of the hydraulic cylinder 2. The tank 23 was provided as a storage means. However, the storage means is not limited to the tank 23 and may be other means such as an accumulator. If, for example, an accumulator incorporated in the piping is used as the storage means, unlike the case where the tank is fixed to a base other than the piping, the posture of the actuator device 1 can be changed. Can take any posture. As a result, when designing a device including the actuator device 1, the degree of freedom in the mounting direction is large, so that the design can be facilitated.

  The method for determining the stability of the operation of the actuator is not limited to the method of the first embodiment, and other methods can be used.

  As described above, the present invention is useful for an actuator device suitable for, for example, suppressing vibrations in a mechanical device, ensuring safety, a power assist system, and the like.

1 is a block diagram illustrating a configuration of an actuator device according to a first embodiment. It is a block diagram of an actuator device concerning a modification. 3 is a control block diagram according to Embodiment 1. FIG. It is a block diagram which shows the structure of the power assist apparatus which concerns on Embodiment 2. FIG. 6 is a timing chart of control according to the second embodiment. It is a timing chart of control concerning a modification. It is a block diagram which shows the structure of the conventional actuator apparatus . It is a figure explaining that a vibration phenomenon occurs in the conventional actuator device at the time of operation attenuation.

Explanation of symbols

1 Actuator device 2 Hydraulic cylinder (actuator)
2a Cylinder body 2b Piston rod 3 Hydraulic pump 4 Motor 5 First pipe 6 Second pipe 7 First throttle mechanism 8 Second throttle mechanism 14 Operating device 15 Control device 16 Sensor 20 Power assist device

Claims (5)

An actuator that is driven by fluid supply;
A pump for supplying fluid to the actuator;
A conduit connecting the pump and the actuator;
A motor for driving the pump;
A throttling mechanism that is provided in the pipe and can be switched between a throttling state that reduces the flow rate of the fluid flowing through the pipe line and a non-throttle state that does not substantially reduce the flow rate of the fluid flowing through the pipe line ;
A sensor for detecting the operation of the actuator;
An operating device for operating the actuator via the pump by giving a command to the motor;
A control device that sets the diaphragm mechanism to the throttle state or the non-throttle state based on a command given to the motor from the operation device and an operation of the actuator;
The direction of the driving force that should be generated in the actuator when a positive command is given from the operating device is the positive direction, and the direction of the driving force that should be generated in the actuator when a negative command is given from the operating device. When the direction is negative,
The control device includes:
A sign of a command (hereinafter referred to as an initial command) to be given by the operating device is compared with a sign of the speed of the actuator detected by the sensor;
When the signs of the initial command and the speed of the actuator are different, the absolute value of the command actually given to the motor from the operating device is set to 0 or smaller than the absolute value of the initial command, and Set the aperture mechanism to the aperture state,
An actuator that, when the sign of the initial command and the speed of the actuator are the same, sets the initial command as a command that is actually given to the motor from the operating device, and sets the throttle mechanism to the non-throttle state apparatus. An actuator that is driven by fluid supply;
A pump for supplying fluid to the actuator;
A conduit connecting the pump and the actuator;
A motor for driving the pump;
A throttling mechanism that is provided in the pipe and can be switched between a throttling state that reduces the flow rate of the fluid flowing through the pipe line and a non-throttle state that does not substantially reduce the flow rate of the fluid flowing through the pipe line;
A sensor for detecting the operation of the actuator;
An operating device for operating the actuator via the pump by giving a command to the motor;
A control device that sets the diaphragm mechanism to the throttle state or the non-throttle state based on a command given to the motor from the operation device and an operation of the actuator;
The control device determines whether or not the operation of the actuator is stable based on a command given to the motor from the operating device and the operation of the actuator. An actuator device that is set to an aperture state and sets the aperture mechanism to the aperture state when it is not stable . The actuator includes a cylinder body, a fluid pressure having a cylinder body and a piston rod that divides the inside of the cylinder body into a first pressure chamber and a second pressure chamber and extends outside the cylinder body through the second pressure chamber. Consisting of cylinders,
The pipe has a first pipe that communicates the pump and the first pressure chamber, and a second pipe that communicates the pump and the second pressure chamber,
When the piston rod extends, fluid is supplied to the first conduit through which fluid flows from the pump toward the first pressure chamber, and when the piston rod contracts, the pump moves toward the second pressure chamber. A storage means for recovering a part of the fluid in the second pipe flowing;
The actuator device according to claim 1 or 2 . The aperture mechanism is configured to be able to arbitrarily adjust the aperture amount.
The actuator device according to any one of claims 1 to 3 . A power assist device equipped with the actuator device according to any one of claims 1 to 4 .

Images