JP6098122B2 - Hydraulic actuator - Google Patents

Description

  The present invention relates to a hydraulic actuator.

  Patent Document 1 listed below discloses a suspension that improves braking performance. This suspension increases the wheel load and shortens the braking distance by controlling the hydraulic cylinder to extend when the slip ratio is greater than the target slip ratio when the braking state of the vehicle is sudden braking. When the slip ratio is smaller than the target slip ratio, the hydraulic cylinder is controlled to be contracted.

JP 2007-320413 A

  By the way, in the said prior art, the supply amount of the hydraulic fluid to a hydraulic cylinder is adjusted by controlling the hydraulic pump which supplies working oil to a hydraulic cylinder, and the operation | movement of a hydraulic cylinder is controlled. However, in the above prior art, the hydraulic pressure applied to the hydraulic cylinder fluctuates due to the influence of hydraulic oil pulsation caused by the hydraulic pump, ambient temperature change, and the like, so that the operation of the hydraulic cylinder cannot be stabilized.

  This invention is made | formed in view of the situation mentioned above, and aims at stabilizing operation | movement by stabilizing the applied hydraulic pressure.

  In order to achieve the above object, in the present invention, as a first solution, a hydraulic oil storage chamber that stores hydraulic oil is provided, and an operating unit that is driven by the hydraulic oil in the hydraulic oil storage chamber, and a hydraulic oil storage A means is provided that includes an auxiliary storage chamber that is provided in communication with the chamber and includes an expandable and contractible gas container sealed with gas.

  In the present invention, as the second solving means, a means is provided in which, in the first solving means, a sensor for detecting the expansion / contraction state of the gas container is further provided.

  In the present invention, as the third solving means, the means in the first solving means is further provided with a generator that generates electric power by expansion and contraction of the gas container.

  In the present invention, as a fourth solving means, in any one of the first to third solving means, the gas container is formed by joining the outer peripheries of two diaphragms, and one of the diaphragms Adopt a means that is opposed to hydraulic oil.

  In the present invention, as a fifth solving means, in any one of the first to fourth solving means, the operating portion includes a piston that receives the pressure of the hydraulic oil and a rod that is fixed to the piston. A means is adopted in which the storage chamber is provided in one or both of the piston and the rod.

  According to the present invention, the working oil is stored in the auxiliary storage chamber by providing the auxiliary storage chamber provided in communication with the hydraulic oil storage chamber and having a gas container in which the gas is sealed. Since the hydraulic pressure applied to the operating unit can be stabilized, the operation of the operating unit can be stabilized. Further, according to the present invention, the auxiliary storage chamber is provided in communication with the hydraulic oil storage chamber of the operating portion, that is, since the auxiliary storage chamber is provided in the operating portion, the auxiliary storage chamber and the operating portion are connected by piping. When connected, a reaction delay caused by the length of the pipe can be suppressed.

1 is a schematic configuration diagram of a hydraulic actuator A according to an embodiment of the present invention. It is sectional drawing of the thrust generator 1 in one Embodiment of this invention. It is sectional drawing which shows the modification of one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The hydraulic actuator A according to the present embodiment dynamically controls the thrust generated by the thrust generator 1 interposed between the damping object T and the support base D to vibrate the damping object T. As shown in FIG. 1, the thrust generator 1, the first hydraulic pump 2a, the first oil storage tank 3a, the first pump motor 4a, and the first motor driver are realized. 5a, a first pulse generator 6a, a second hydraulic pump 2b, a second oil storage tank 3b, a second pump motor 4b, a second motor driver 5b, a second pulse generator 6b, and a controller 7. Yes.

  Assuming that the hydraulic actuator A is used as, for example, a vehicle suspension, the vibration damping object T is a vehicle body, and the support frame D is a tire support arm. Further, the vibration source in the figure is a road surface, and the spring element E1 interposed between the road surface and the support frame D is a tire. Further, the spring element E2 interposed between the vibration control object T (vehicle body) and the support base D (support arm) is a spring coil, and the damping element E3 is, for example, a gas-filled damper.

As shown in FIG. 2, the thrust generator 1 includes an operation unit 11, an auxiliary storage chamber 12, a gas introduction pipe 13, and an expansion / contraction state detection unit 14.
The operation unit 11 is interposed between the vibration suppression target T and the support base D, and is driven by hydraulic pressure to generate a thrust necessary for vibration control of the vibration suppression target T. The cylinder 11a, A piston 11b and a rod 11c are provided.

The cylinder 11a is a cylindrical part that accommodates hydraulic oil in an internal chamber.
The piston 11b is a disk-shaped component that divides a chamber inside the cylinder 11a into two chambers (first chamber R1 and second chamber R2) and is reciprocally moved along the inner wall of the cylinder 11a. Further, the first chamber R1 is provided with an oil supply port P1, and working oil is supplied from the first hydraulic pump 2a. The second chamber R2 is also provided with an oil supply port P2, and working oil is supplied from the second hydraulic pump 2b.

  The rod 11c is a rod-like component having one end fixed to the piston 11b so that its own central axis coincides with the central axis of the piston 11b. The other end of the rod 11c penetrates from the first chamber R1 side of the cylinder 11a to the outside, and is connected to a vibration control target T to which a thrust generated by the operating unit 11 is to be applied.

  The auxiliary storage chamber 12 is connected to the bottom of the cylinder 11a and communicates with the second chamber R2 of the cylinder 11a. The auxiliary storage chamber 12 includes an expandable / contractible gas container 12a sealed with gas. In the auxiliary storage chamber 12, a male screw portion B is formed on the surface, and the male screw portion B is coupled to the cylinder 11 a by screwing into a screw hole that penetrates the bottom portion of the cylinder 11 a. Further, an elongated tube B1 is formed in the male threaded portion B of the auxiliary storage chamber 12 along the central axis. That is, the auxiliary storage chamber 12 and the second chamber R2 of the cylinder 11a communicate with each other via the pipe B1 provided in the male screw portion B.

  The gas container 12a is formed by joining the outer peripheries of two stretchable metal diaphragms a1 and a2, and one diaphragm a1 is opposed to the pipe B1 provided in the male screw portion B. That is, it is arranged in the auxiliary storage chamber 12 so as to oppose the hydraulic oil. In such a gas container 12a, one end of a gas introduction pipe 13 is inserted, and the pressurized gas supplied through the gas introduction pipe 13 is sealed inside. In addition, although the said pressurized gas may be air, it suppresses that pressurized gas leaks into working oil from the gas container 12a by selecting nitrogen gas whose molecular size which comprises gas is larger than oxygen and a carbon dioxide. it can.

  The auxiliary storage chamber 12 configured in this manner functions as an accumulator. That is, when the pressure of the hydraulic oil stored in the second chamber R2 of the cylinder 11a becomes higher than the pressure of the pressurized gas sealed in the gas container 12a, the gas container 12a is compressed and the hydraulic oil is stored in the auxiliary storage chamber 12. On the other hand, when the pressure of the hydraulic oil stored in the second chamber R2 of the cylinder 11a becomes lower than the pressure of the pressurized gas sealed in the gas container 12a, the expansion of the gas container 12a causes the cylinder 11a to move from the auxiliary storage chamber 12 to the cylinder 11a. The hydraulic oil is discharged into the second chamber R2.

  One end of the gas introduction pipe 13 is inserted into the gas container 12a, the other end is connected to a gas pump (not shown), and is connected to the opposite side of the male screw portion B communicating the auxiliary storage chamber 12 and the second chamber R2 of the cylinder 11a. Is provided. Such a gas introduction pipe 13 introduces the pressurized gas supplied from the gas pump into the gas container 12, or sends out the pressurized gas in the gas container 12a to the gas pump by the suction operation of the gas pump.

  The expansion / contraction state detection unit 14 is a sensor that detects the expansion / contraction state of the gas container 12, and includes a coil 14a and a magnet 14b. The coil 14 a is an insulating film-covered wire in which the surface of a metal wire such as copper (Cu) or Ag is covered with a predetermined insulating film, and is wound around the peripheral surface of the gas introduction pipe 13. Both ends of such a coil 14 a are connected to the input ends of the controller 7. The magnet 14b is an arc-shaped permanent magnet that is fixed along the outer periphery of the coil 14a at a distance from the coil 14a.

  The first hydraulic pump 2a is, for example, a two-way discharge type displacement pump, and has an input shaft connected to the rotating shaft of the first pump motor 4a and one discharge port through the pipe. The other discharge port is connected to the first oil storage tank 3a through a pipe. In the first hydraulic pump 2a, the discharge direction of the hydraulic oil (in other words, from which discharge port the hydraulic oil is discharged) is determined by the rotation direction of the input shaft, and the rotation speed (rotation speed) of the input shaft. Determines the discharge flow rate. The first oil storage tank 3a is a container for storing the hydraulic oil discharged from the first hydraulic pump 2a.

  The first pump motor 4a is, for example, an AC servo motor, and rotates according to a motor drive signal supplied from the first motor driver 5a. Since the rotation shaft of the first pump motor 4a is connected to the input shaft of the first hydraulic pump 2a, the first pump motor 4a can be controlled by controlling the rotation direction and the rotation speed of the first pump motor 4a. The discharge direction and discharge flow rate of the hydraulic oil by the hydraulic pump 2a can be arbitrarily controlled.

  The first motor driver 5a generates a motor drive signal (drive current) for driving the first pump motor 4a in accordance with the rotational speed command value input from the controller 7 to the first pump motor 4a. Output. The first pulse generator 6a is, for example, a rotary encoder, and a pulse signal corresponding to the rotation of the first pump motor 4a (specifically, the time required for the first pump motor 4a to rotate at a certain angle). This is a pulse generator that generates a pulse signal having one cycle and outputs it to the first motor driver 5a. The first motor driver 5a is fed back with such a pulse signal output from the first pulse generator 6a, and the rotational speed indicated by the rotational speed command value and the actual first pump motor 4a. The feedback control can be performed so that the rotational speed of the two coincides.

  Similarly to the first hydraulic pump 2a, the second hydraulic pump 2b is, for example, a two-way discharge type displacement pump, and has an input shaft connected to the rotating shaft of the second pump motor 4b, The discharge port is connected to the second chamber R2 of the operating unit 11 via a pipe, and the other discharge port is connected to the second oil storage tank 3b via the pipe. In the second hydraulic pump 2b, similarly to the first hydraulic pump 2a, the discharge direction of the hydraulic oil is determined by the rotation direction of the input shaft, and the discharge flow rate is determined by the rotation speed of the input shaft. The second oil storage tank 3b is a container for storing the hydraulic oil discharged from the second hydraulic pump 2b.

  The second pump motor 4b is, for example, an AC servo motor, and rotates according to a motor drive signal supplied from the second motor driver 5b. Since the rotation shaft of the second pump motor 4b is connected to the input shaft of the second hydraulic pump 2b, the second pump motor 4b can be controlled by controlling the rotation direction and the rotation speed of the second pump motor 4b. The discharge direction and discharge flow rate of the hydraulic oil by the hydraulic pump 2b can be arbitrarily controlled.

  The second motor driver 5b generates a motor drive signal (drive current) for driving the second pump motor 4b in accordance with the rotational speed command value input from the controller 7, and sends it to the second pump motor 4b. Output. The second pulse generator 6b is, for example, a rotary encoder, and a pulse signal corresponding to the rotation of the second hydraulic pump 2b (specifically, the time required for the second pump motor 4b to rotate at a certain angle). This is a pulse generator that generates a pulse signal having one cycle and outputs it to the second motor driver 5b. The pulse signal output from the second pulse generator 6b is fed back to the second motor driver 5b, and the rotation speed indicated by the rotation speed command value and the actual second pump motor 4b. The feedback control can be performed so that the rotational speed of the two coincides.

  As described above, in the present embodiment, the first pump motor 4a and the second pump motor 4b are controlled between the first chamber R1 and the second chamber R2 by controlling the rotation direction and the rotation speed of the second pump motor 4b. Pressure difference can be generated, and as a result, the thrust (force acting on the vibration control target T) generated in the operating portion 11 can be arbitrarily controlled.

  The controller 7 is a control device that performs overall control of the hydraulic actuator A, and is electrically connected to the first motor driver 5a, the second motor driver 5b, the expansion / contraction state detector 14 and the like. For example, the controller 7 controls the rotation of the first pump motor 4a and the second pump motor 4b based on the damping force command value input from the host controller J. Here, the damping force command value input from the host controller J is, for example, a value corresponding to the resistance force to the relative speed calculated based on the relative speed between the control object T and the support base D. (In other words, attenuation coefficient). That is, the host control device J calculates the damping force command value corresponding to the resistance force to the relative speed based on the output signal of the relative speed detection unit S that detects the relative speed between the control object T and the support base D. And output to the controller 7. Moreover, although mentioned later for details, the controller 7 detects the expansion-contraction state of the auxiliary storage chamber 12 based on the electric power input from the coil 14a of the expansion-contraction state detection part 14. FIG.

  Next, the effect and operation of the hydraulic actuator A configured as described above will be described. The auxiliary storage chamber 12 functions as an accumulator provided in the operating unit 11. That is, the auxiliary storage chamber 12 is operated by compressing the gas container 12a when the pressure of the hydraulic oil stored in the second chamber R2 of the cylinder 11a becomes higher than the pressure of the pressurized gas sealed in the gas container 12a. When the pressure of the hydraulic oil stored in the second chamber R2 of the cylinder 11a becomes lower than the pressure of the pressurized gas sealed in the gas container 12a, the second chamber R2 of the cylinder 11a is expanded by the expansion of the gas container 12a. To release hydraulic oil.

  In the gas container 12a, when one diaphragm a1 is compressed, the other diaphragm a2 is expanded by the compressed gas inside. As a result, the coil 14 a of the expansion / contraction state detection unit 14 moves downward, so that an electromotive force is generated by electromagnetic induction and input to the controller 7. Further, when the pressure of the hydraulic oil becomes low and one diaphragm a1 swells, the other diaphragm a2 contracts. Also at this time, since the coil 14a of the expansion / contraction state detector 14 moves upward, an electromotive force is generated by electromagnetic induction and input to the controller 7. And the controller 7 detects the expansion-contraction state of the gas container 12a based on the electromotive force input from the coil 14a of the expansion-contraction state detection part 14. FIG.

  According to this embodiment, by providing the auxiliary storage chamber 12 provided in communication with the second chamber R2 of the cylinder 11a and having a gas container 12a in which gas is sealed, the auxiliary storage chamber 12 is provided. Since the working oil can be stored in the storage chamber 12 and the hydraulic pressure applied to the operating unit 11 can be stabilized, the operation of the operating unit 11 can be stabilized. Moreover, according to this embodiment, since the auxiliary storage chamber 12 is provided in the operation part 11, when the auxiliary storage chamber 12 and the operation part 11 are connected by piping, it generate | occur | produces with the length of piping. Reaction delay can be suppressed. Moreover, according to this embodiment, the expansion-contraction state of the gas container 12a is detectable by using the said expansion-contraction state detection part 14 and the controller 7. FIG.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, For example, the following modifications can be considered.
(1) In the above embodiment, the case of adopting the configuration in which the hydraulic oil is supplied to the first chamber R1 and the second chamber R2 of the cylinder 11a is exemplified, but the present invention is not limited to this, and the second chamber R2 is not limited to this. A configuration in which only hydraulic oil is supplied may be employed.

(2) In the above-described embodiment, for example, a vehicle suspension is assumed as an application. However, the present invention is not limited to this, and a medium such as a die cushion device provided in a press machine is interposed between a vibration control object and a support frame. By dynamically controlling the thrust generated by the installed thrust generator 1, the present invention can be widely used in applications for performing vibration suppression control of vibration suppression objects.

(3) In the above embodiment, the first and second motor drivers 5a and 5b are used. However, a torque control motor driver may be used instead of the first and second motor drivers 5a and 5b. . That is, the motor driver for torque control generates a motor drive signal for controlling the torque of the first and second pump motors 4a and 4b in accordance with the rotation speed command value input from the controller 7 to generate the first To the second pump motors 4a and 4b. In this case, the first and second pulse generators 6a and 6b are not necessary.

(4) In the above embodiment, the auxiliary storage chamber 12 including the gas containers including the diaphragms a1 and a2 is employed as the accumulator. However, in addition to the diaphragm, the auxiliary storage chamber 12 including the bladder as the gas container may be employed. Good.
(5) Although the expansion / contraction state detection unit 14 is mounted in the above embodiment, the expansion / contraction state detection unit 14 may not be mounted. Further, instead of the expansion / contraction state detection unit 14, as in the expansion / contraction state detection unit 14, a generator that is configured and includes a coil and a magnet and generates electricity by expansion / contraction of the gas container 12 may be mounted. Further, instead of the expansion / contraction state detection unit 14, a position adjustment unit made of a coil and a magnet is installed as in the expansion / contraction state detection unit 14, and power is supplied from the controller 7 to the coil of the position adjustment unit. Thus, the vertical position of the gas container 12 may be adjusted to change the characteristics when the auxiliary storage chamber 12 functions as an accumulator.

(6) In the above embodiment, the auxiliary storage chamber 12 is provided at the bottom of the cylinder 11a, but the present invention is not limited to this. For example, as shown in FIG. 3 (a), in a thrust generator 21 having a cylinder 21a and a piston / rod 21b, an auxiliary storage chamber 21c is provided in the piston / rod 21b, and a bladder type gas container is provided in the auxiliary storage chamber 21c. 21d may be provided. At this time, it is necessary to provide the opening K1 in order to connect the chamber R4 of the cylinder 21a and the auxiliary storage chamber 21c. A gas introduction pipe 21e is connected to the bladder type gas container 21d.

  Further, as shown in FIG. 3B, in the thrust generator 31 including the cylinder 31a and the piston / rod 31b, an auxiliary storage chamber 31c is provided in the piston / rod 31b, and a diaphragm type gas container is provided in the auxiliary storage chamber 31c. 31d may be provided. Also in this case, it is necessary to provide the opening K2 in order to connect the chamber R5 of the cylinder 31a and the auxiliary storage chamber 31c. A gas introduction pipe 31e is connected to the diaphragm type gas container 31d. In addition, about a gas container, you may make it provide in either a piston or a rod.

DESCRIPTION OF SYMBOLS A ... Hydraulic actuator, T ... Damping object, D ... Support stand, 1 ... Thrust generator, 2a ... 1st hydraulic pump, 3a ... 1st oil storage tank, 4a ... 1st pump motor, 5a ... 1st 1 motor driver, 6a ... 1st pulse generator, 2b ... 2nd hydraulic pump, 3b ... 2nd oil storage tank, 4b ... 2nd pump motor, 5b ... 2nd motor driver, 6b ... 2nd Pulse generator, 7 ... Controller 7, E1, E2 ... Spring element, E3 ... Damping element, 11 ... Actuator, 12 ... Auxiliary storage chamber, 13 ... Gas introduction pipe, 14 ... Stretching state detector, 11a ... Cylinder, 11b ... Piston, 11c ... Rod, R1 ... First chamber, R2 ... Second chamber, 12a ... Gas container, 14a ... Coil, 14b ... Magnet, B ... Male thread, B1 ... Pipe, J ... Host controller, S ... Relative speed Detector, a1, DESCRIPTION OF SYMBOLS 2 ... Diaphragm, 21 ... Thrust generator, 21a ... Cylinder, 21b ... Piston / rod, 21c ... Auxiliary accommodation chamber, 21d ... Bladder type gas container, 21e ... Gas introduction pipe, K1 ... Opening, R4 ... Room, 31 ... Thrust Generator 31a ... Cylinder, 31b ... Piston / rod, 31c ... Auxiliary storage chamber, 31d ... Diaphragm type gas container, 31e ... Gas introduction pipe, K2 ... Opening, R5 ... Room, P1, P2 ... Refueling port

Claims (4)

A hydraulic oil storage chamber for storing the hydraulic oil, and an operating portion driven by the hydraulic oil in the hydraulic oil storage chamber;
An auxiliary storage chamber provided in communication with the hydraulic oil storage chamber and having an expandable and contractible gas container sealed with gas ;
A coil interlocking with expansion and contraction of the gas container;
A hydraulic actuator, comprising: a magnet attached to the auxiliary storage chamber and surrounding the coil . The hydraulic actuator according to claim 1 , further comprising a detection unit electrically connected to the coil . 3. The hydraulic actuator according to claim 1, wherein the gas container is formed by joining outer peripheries of two diaphragms, and one of the diaphragms faces the hydraulic oil. The operating portion includes a piston that receives the pressure of hydraulic oil and a rod fixed to the piston, and the auxiliary storage chamber is provided in one or both of the piston and the rod. Item 4. The hydraulic actuator according to any one of Items 1 to 3 .

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