KR20060117577A - Hybrid actuator system of electric-hydraulic united control type - Google Patents

Abstract

An electric-hydraulic integrated control type hybrid actuator system is provided to reduce possibility of pressure loss and oil leakage by removing unnecessary pipe or hose and to immediately precisely compensate and control operation by reflecting operation of the actuator itself to operation of a hydraulic pressure generating unit as feedback. An electric-hydraulic integrated control type hybrid actuator system comprises a servo motor(10) giving the driving force to a pump and having a shaft connected with a shaft of a hydraulic pump(20) to regulate rotation speed and direction by regulation of a control system; the two-way hydraulic pump converting the driving force into hydraulic pressure and having the shaft connected with the shaft of the servo motor, a discharge port, and an inflow port about operating oil; two check valves(30) installed adjacent to the discharge port and the inflow port of the hydraulic pump to block reverse flow of the operating oil to the hydraulic pump; a pilot check valve(40) installed adjacent to an oil tank(50) to block the operating oil discharged to the oil tank; the oil tank storing operating oil and supplying to the hydraulic pump; a double-acting actuator(60) having a cylinder(61) and a piston(62) tightly contacted on the inner wall of the cylinder to form two independent hydraulic chambers(63,64) in the cylinder; a hydraulic pipe(70) connecting the hydraulic pump, the check valve, the pilot check valve, the oil tank, and the actuator; and the control system measuring hydraulic pressure of both hydraulic chambers, position of the piston, and power generated by the actuator while working with external load to regulate rotation speed and direction of the servo motor.

Description

Hybrid Actuator System of Electric-Hydraulic United Control Type

1 is a perspective view showing a hydraulic motor and a hydraulic pump integrated in accordance with the present invention,

Figure 2 is a perspective view showing a state in which the oil tank is mounted on the hydraulic motor and the hydraulic pump integrated in accordance with the present invention,

Figure 3a is a side view showing the piping structure of the integrated hydraulic motor and the hydraulic pump of the present invention,

Figure 3b is a plan view showing a piping structure of the integrated hydraulic motor and the hydraulic pump of the present invention,

4 is a cross-sectional view showing the structure of a hydraulic pump used in the present invention,

5 is a hydraulic circuit diagram of the actuator system of the present invention;

6 is a configuration diagram showing a control system of the actuator system of the present invention;

7 is a control block diagram of the actuator system of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: servo motor 20: hydraulic pump

30: check valve 40: pilot check valve

50: oil tank 60: actuator

70: hydraulic piping 80: control system

81: pressure sensor 82: position sensor

83: force sensor B: control block

The present invention relates to a hybrid actuator using a hydraulic pressure, to an electro-hydraulic integrated hybrid actuator capable of realizing a compact appearance, capable of precise control, and an intermediate stop function.

Actuator is a device that converts various energy such as light energy, pressure, electric force, wind into useful work, and it is a mechanical device with a wide range of use from a huge oil drilling device to a recently developed polymer actuator. it means.

The present invention relates to an actuator in the form of a cylinder that converts the pressure energy generated by the working oil into a form of mechanical work, wherein the piston mounted inside the cylinder operates according to the change in the hydraulic pressure generated by the hydraulic motor and the hydraulic pump. A hydraulic actuator for performing work.

In general, the hydraulic pump refers to a device that converts the state of the hydraulic fluid flow, specifically, pressurizes the hydraulic oil and converts the hydraulic oil into pressure energy in the form of hydraulic pressure. According to the structure of the pump operation part, it is classified into rotary type (gear pump, vane pump, screw pump) and reciprocating type (piston pump), and most of these hydraulic pumps are operated by receiving the driving force from the hydraulic motor rotating by electricity. do.

The hydraulic motors, hydraulic pumps, actuators connected to them, and the pipes, valves and control systems connecting them form a single hydraulic system. These hydraulic systems can be classified according to their operating patterns. It can be divided into valve control system and pump control system.

The valve control system is a system that finally controls the position, speed, and direction of the actuator by distributing and controlling the oil pressure generated from the oil pressure generating device using only various valves. Since it controls opening and closing etc., it is a system also called a hydraulic control system.

On the other hand, the pump driving system controls the rotation angle and the speed of the electric servo motor directly connected to the hydraulic generator to control the distribution and size of the hydraulic pressure without the intervention of the valve, thereby finally controlling the position, speed, pressure and force of the actuator. As a system to be controlled, it is also called an electric control system because it controls whether or not the size of the hydraulic pressure is applied (or opened or closed) in the generation step using the motor drive.

Of these, the pump control (electric control) system can supply a hydraulic source only to the corresponding actuator instead of the existing large-capacity hydraulic source, thereby miniaturizing the hydraulic source, and supplying hydraulic pressure to the actuator only when necessary, thereby providing a valve control system. Compared to the hydraulic system that can save a lot of energy.

It is rare to selectively use only such an electric control system when implementing a hydraulic system for actual actuator operation, and it is usually used together with the hydraulic control system to obtain a desired control effect.

As described above, a number of examples of implementing a hydraulic actuator using a hydraulic control system or an electric control system are also disclosed as a technique on an existing patent / utility model. For example, Japanese Patent Laid-Open No. 2001-234869 discloses a rotational speed. In the attempt to detect the rotational speed of the hydraulic pump connected to the electric motor by using a detector, adjust the current value of the three-phase alternating current and adjust the rotational speed of the electric motor again, and stably control the speed regardless of the load. Has been disclosed.

In addition, Japanese Patent Laid-Open No. 2001-132649 discloses a flow rate / pressure using a pressure compensated flow control valve by measuring a discharge flow rate and a pressure of a hydraulic pump (hydraulic pump) while simultaneously controlling the generated hydraulic pressure using a servo motor. Japanese Patent Laid-Open Publication No. 2001-248566 discloses a hydraulic system for controlling a hydraulic pressure for detecting a discharge pressure of a liquid pump, calculating a flow compensation amount based on the hydraulic pressure, and then controlling the speed of the motor according to the compensation amount. It has been disclosed for the system.

In addition, in Japanese Patent Laid-Open No. 2003-214351, variables such as a pressure command, a pressure feedback signal, a flow rate command, a flow rate feedback signal, and the like are designated, respectively, and the pressure and flow rate deviation are compared to select which one to control. Thereafter, an attempt has been made to perform control using both pressure and flow rate by comparing, feeding back, and controlling the corresponding variables.

However, all of these attempts still employ pressure or flow compensating mechanisms in the form of control valves, which not only slows the reaction but also reduces the accuracy, or measures the discharge pressure or flow rate of the hydraulic pump or even the rotational speed of the hydraulic pump itself. By using a method of compensating pressure or flow rate, one or more disadvantages of the actual actuator may be questioned whether the control result can be obtained as precisely as desired.

This means that the components of the hydraulic tank, hydraulic motor, hydraulic pump, and actuator used in these systems are connected to each other through a hydraulic hose, etc., and each of the components is individually driven by a kind of independent hydraulic system, thereby providing a distance from the hydraulic source. This is because it can have different pressure loss and characteristics.

Therefore, the hydraulic pressure compensated based on the discharge hydraulic pressure or the flow rate from the hydraulic pump, or even the rotation speed of the hydraulic pump or the motor itself, is not easy to perform the control operation with the desired precision for the actual actuator operation. Can be.

As one of ways to solve the problem, there may be an attempt to suppress the occurrence of hydraulic loss itself. For example, in Korean Utility Model Registration No. 328483, by connecting the shaft of the electric motor and the shaft of the hydraulic pump, Attempts have been made to minimize the occurrence of hydraulic losses by integrating and mounting them on a single rod actuator.

However, such a prior art approach has a clear limitation in the approach of minimizing pressure loss to suppress the occurrence of an error in actuator control itself, because the pressure loss can be minimized but not completely prevented.

Therefore, the new hydraulic actuator can minimize the pressure loss itself, and thus the hydraulic pressure generated by the driving motor can be transmitted as far as possible to the actuator as it is, and at the same time, the control to compensate for the inevitable errors can be performed. It is a situation that requires the advent of the system.

Accordingly, the present invention has been made in view of the above-mentioned conventional defects, and its object is to reduce the possibility of pressure loss and leakage itself by eliminating unnecessary pipes and hoses by constituting the driving motor and the hydraulic pump in one piece. In addition to the number of rotations of the motor, the number of rotations of the hydraulic pump, the hydraulic pressure or the flow rate of the actuator itself is immediately feedback to the operation of the hydraulic generator, the desired compensation control operation can be performed immediately and precisely, the hydraulic actuator To provide a system.

Another object of the present invention is to provide a hydraulic actuator system, which is not only able to reduce costs by using energy only when necessary for actuator operation, but also is configured to allow intermediate stopping of the actuator.

In addition, other objects, objects and advantages of the present invention will be described below, and will be appreciated by the embodiments of the present invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the claims.

The present invention relates to an electro-hydraulic integrated control hybrid actuator system that can realize a compact appearance, precise control, and an intermediate stop function, which can prevent pressure loss at the generation stage as well as reduce errors in actuator operation. The present invention relates to an electro-hydraulic integrated control hybrid actuator system capable of feedback control of hydraulic pressure.

Specifically, the present invention is configured so as to form a single hydraulic system by connecting the shaft of the hydraulic motor and the shaft of the hydraulic pump so as not to generate a hydraulic loss due to the pipe or hose, and to measure the hydraulic pressure in the hydraulic line entering the actuator The present invention relates to an electro-hydraulic integrally controlled hybrid actuator configured to feedback control the generated pressure and configured to feedback control the generated pressure by reflecting the position of the actuator.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and the appended claims should not be construed as being limited to the ordinary or dictionary meanings, and the inventors should properly explain the concept of terms in order to explain their own invention in the best way. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the configuration shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be substituted for them at the time of the present application It should be understood that there may be equivalents and variations.

In addition, detailed and detailed descriptions of the parts of the electrohydraulic integrated control hybrid actuator system of the present invention described in detail below, which are not directly related to the actual contents and effects of the present invention, such as a specific shape of a power supply, wiring, and a valve, are omitted. It is noted that any device that can be applied without departing from the technical spirit of the present invention may be used.

1 is a perspective view showing a hydraulic motor and a hydraulic pump integrated in accordance with the present invention, Figure 2 is a perspective view showing a state in which the oil tank is mounted on the hydraulic motor and the hydraulic pump integrated in accordance with the present invention, Figure 3a Figure 3 is a side view showing the piping structure of the integrated hydraulic motor and the hydraulic pump, Figure 3b is a plan view showing the piping structure of the integrated hydraulic motor and the hydraulic pump of the present invention, Figure 4 is a structure of the hydraulic pump used in the present invention It is sectional drawing shown, FIG. 5 is a hydraulic circuit diagram of the actuator system of this invention, FIG. 6 is a block diagram which shows the control system of the actuator system of this invention, and FIG. 7 is a block diagram which shows the control block diagram of the actuator system of this invention.

As shown in Figs. 1 to 4, the electrohydraulic integrally controlled hybrid actuator system of the present invention provides a driving force to the pump, and the shaft 11 is connected to the shaft 21 of the hydraulic pump 20 to be integrated. Servo motor 10 is configured to control the stop / rotation, rotation speed and rotation direction by the control of the control system 80; The driving force transmitted from the servo motor 10 is converted into hydraulic pressure. The shaft 21 is connected to the shaft 11 of the servo motor 10 to be integrally formed, and the discharge port 22 and the inlet port 23 of the hydraulic oil are integrated. A bidirectional hydraulic pump 20 is provided; Two check valves 30 provided adjacent to the discharge port 22 and the inlet port 23 of the hydraulic pump 20 to block hydraulic oil from flowing back to the hydraulic pump 20; A pilot check valve 40 provided adjacent to the oil tank 50 to block hydraulic oil from being discharged to the oil tank 50; An oil tank 50 for storing hydraulic oil and supplying the hydraulic oil; A double-acting actuator (60) provided with a cylindrical cylinder (61) and a piston (62) in close contact with the inner wall of the cylinder (61) to form two independent hydraulic chambers (63) (64) in the cylinder (61); A hydraulic pipe 70 connecting the hydraulic pump 20, the check valve 30, the pilot check valve 40, the oil tank 50, and the actuator 60; And the rotational direction of the servomotor 10 by detecting the hydraulic pressure of both the hydraulic chambers 63 and 64 of the actuator 60 and the position of the piston 62 in the cylinder 61 and the force generated by the actuator during external load operation. It is configured to include a control system 80 for controlling the speed.

In the present invention, the servo motor 10 is controlled to stop and rotate, the speed and the rotation direction by the control of the control system 80, the control amount for the stop and rotation, rotation speed and the rotation direction in advance by the user It is determined by the input data about the forward and backward, the operating speed and the operation direction of the predetermined actuator and the feedback signal transmitted from the pressure sensor 81 and the position sensor 82.

In addition, the servomotor 10 used in the present invention is configured by directly connecting the shaft 11 to the shaft 21 of the hydraulic pump 20, so that side effects such as hydraulic loss or leakage due to the use of pipes and hoses, etc. In this way, it is possible to give greater precision to the compensation operation of the pump according to the feedback control.

In the present invention, the hydraulic pump 20, as shown in Figure 4, by rotating the shoe member 26 connected to the piston 25 in the hydraulic cylinder 24 along the upper surface of the fixed swash plate member 27 reciprocating motion Axial piston type hydraulic pump is used.

In addition, the applicant of the Republic of Korea Utility Model Registration No. 0169204, the spherical portion is formed in the center so as to contact the spherical barrel of the lower end of the cylinder, the groove is formed so that the shoe member connected to the piston can be fitted in the circumference, As described above, a shoe holder, which is formed of a curved elastic body as a whole and has one or more bends configured to add elasticity to a groove portion into which a male member is fitted, is used in the hydraulic pump 20 of the present invention. Holder 28 was used.

In the present invention, the check valve 30 for preventing the hydraulic oil from flowing back to the hydraulic pump 20 is basically a pilot check valve for maintaining the pressure while preventing the hydraulic oil from being discharged to the oil tank 50 ( The servo motor 10 is stopped by the control system 80 by making the actuator 60 an independent hydraulic system together with 40), thereby enabling the actuator 60 to be stopped in the middle.

In addition, the check valve 30 is separated from the hydraulic side by removing the front pump 20, which can be said to occupy a relatively large volume in the entire hydraulic system to prevent hydraulic loss or leakage, such as to reduce the operating error of the system It also plays a role.

In the present invention, the pilot check valve 40 is basically, the control system 80 by making the actuator 60 as an independent hydraulic system together with the check valve 30 to block the hydraulic oil discharged to the hydraulic pump 20. By the servo motor 10 is stopped by this serves to enable the actuator (60) to be an intermediate stop.

In addition, the pilot check valve 40 is separated from the hydraulic side by removing the oil tank 50, which can be said to occupy the largest volume in the entire hydraulic system to prevent hydraulic loss or leakage, such as to reduce the operating error of the system It also plays a role.

In the present invention, the check valve 30 and the pilot check valve 40 configured as described above have the function of enabling the intermediate stop of the actuator and the pressure maintenance while the main connection part is connected by a simple hydraulic pipe.

In the present invention, the oil tank 50 is configured in a size and shape that covers and seals the hydraulic pump 20.

In the present invention, the actuator 60 is provided with a position sensor 82 for use in the intermediate stop, specifically for the intermediate position control of the piston 62 in the cylinder 61 by the control system 80.

In the present invention, the hydraulic pipe 70 was actually used only between the hydraulic pump 20 and the actuator 60, which is composed of the servo motor 10 and the hydraulic pump 20 are integrally connected by the shaft connection in the present invention. At the same time, the oil tank 50 is configured to cover and seal the hydraulic pump 20, thereby minimizing its use, thereby minimizing the possibility of hydraulic loss and leakage.

In the present invention, the control system 80 is a pressure sensor 81 for measuring the hydraulic pressure in the hydraulic pipe 70 of the inlet of the hydraulic chamber (63) (64) of the actuator (60), the actuator (60) cylinder 61 Position sensor 82, which is mounted to the inner piston 62 and configured to protrude in one of the two hydraulic chambers (63) (64) to measure the relative position of the piston in the cylinder (61), is provided at one end of the actuator Force sensor 83 for measuring the force generated during external load operation, rotary encoder 84 for measuring the rotational speed of the servomotor 10, both hydraulic chambers 63, 64 measured at the pressure sensor 81 Pressure, the position in the cylinder 61 of the piston 62 measured by the position sensor 82, the force measured by the force sensor 83 and the rotational speed of the servomotor 10 measured by the rotary encoder 84 By amplifying the control signal of the controller (C) and the controller (C) which control the forward / reverse rotation of the servomotor, increase / decrease and stop / rotation of the servomotor It is configured to include an amplifier 85 for transmission to the servo motor 10.

In the control system 80 of the present invention as described above, any position sensor 82 can be used as long as it can measure the relative position of the piston 62 in the cylinder 61. It is preferable to use a stroke sensor that measures in such a way as to detect.

As shown in FIG. 7, the control block diagram for the actuator proposed in the present invention uses the position Yr, the pressure Pr, and the force Fr measured from the three sensors as described above. Y), the comparison with the target value of the pressure (P) and the target value of the force (F), and corrected through the servo amplifier 94 in order to eliminate the difference, and then to control the servomotor 10, Depending on the type of work, one or two or more of position, speed, pressure and force control can be controlled in combination.

As described above, the actuator system of the present invention, which is implemented in the form of an electro-hydraulic integrated control hybrid, minimizes the occurrence of hydraulic loss, and can feedback control the operating state of the actuator itself. As the hydraulic pump is axially connected and integrated, it can be realized not only in a compact form requiring minimal space but also in taking up less installation space. It also has the effect of saving energy.

Such an electro-hydraulic integrated control hybrid actuator system of the present invention is applicable to various fields including a servo press device, an injection molding machine, an active suspension system, a vehicle niling system, and the like.

The electro-hydraulic integrated control hybrid actuator system configuration of the present invention described above is not limited to the above-described embodiment as described above, but may be variously modified and used in other embodiments. It should be noted that the above technical idea may not be impaired at all.

By completing the present invention as described above, the shaft is connected to the axis of the hydraulic pump is configured integrally, the servo motor is controlled by the control of the stop / rotation, rotational speed and rotational direction; A two-way hydraulic pump whose shaft is connected to the shaft of the servomotor and configured integrally with a discharge port and an inlet port of the working oil; Two check valves provided adjacent to the discharge port and the inlet port of the hydraulic pump; A pilot check valve provided adjacent to the oil tank; An oil tank for storing hydraulic oil and supplying the hydraulic oil; A double-acting actuator having a piston in close contact with the cylindrical cylinder and the inner wall of the cylinder to form two independent hydraulic chambers in the cylinder; A hydraulic pipe connecting the hydraulic pump, the check valve, the pilot check valve, the oil tank and the actuator; And a control system for controlling the rotational direction and the speed of the servomotor by measuring the hydraulic pressure of both actuators and the position of the piston in the cylinder and the force generated by the actuator, to provide an electro-hydraulic integrally controlled hybrid actuator system. It became possible.

By the completion of the present invention, by constituting the drive motor and the hydraulic pump integrally, it is possible to reduce the possibility of pressure loss itself by eliminating unnecessary pipes and hoses, as well as the rotational speed of the motor or the rotational speed, hydraulic pressure or flow rate of the hydraulic pump. In addition, the actuator itself is immediately fed back to the operation of the hydraulic generator so that the desired compensation control operation can be performed immediately and precisely, and the energy can be saved only when the actuator is required. It is possible to provide a hydraulic actuator system, which is configured to enable an intermediate stop of the.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and the present invention is provided by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

Claims (3)

As the driving force is applied to the pump, the shaft 11 is connected to the shaft 21 of the hydraulic pump 20 to be integrally formed, and the stop / rotation, the rotation speed and the rotation direction are controlled by the control system 80. The controlled servomotor 10; The driving force transmitted from the servo motor 10 is converted into hydraulic pressure. The shaft 21 is connected to the shaft 11 of the servo motor 10 to be integrally formed, and the discharge port 22 and the inlet port 23 of the hydraulic oil are integrated. Bidirectional hydraulic pump 20 is provided; Two check valves 30 provided adjacent to the discharge port 22 and the inlet port 23 of the hydraulic pump 20 to block hydraulic oil from flowing back to the hydraulic pump 20; A pilot check valve 40 provided adjacent to the oil tank 50 to block hydraulic oil from being discharged to the oil tank 50; An oil tank 50 for storing hydraulic oil and supplying the hydraulic oil; A double-acting actuator (60) provided with a cylindrical cylinder (61) and a piston (62) in close contact with the inner wall of the cylinder (61) to form two independent hydraulic chambers (63) (64) in the cylinder (61); A hydraulic pipe 70 connecting the hydraulic pump 20, the check valve 30, the pilot check valve 40, the oil tank 50, and the actuator 60; And The rotational direction and speed of the servomotor 10 are measured by measuring the hydraulic pressure of the actuators 60 and 63 and 64, the position of the piston 62 in the cylinder 61, and the force generated by the actuator during external load operation. Characterized in that it comprises a control system 80 for controlling the, Electro-hydraulic integrally controlled hybrid actuator system. The method of claim 1, The hydraulic pump 20 is a swash plate type hydraulic pump using a method of rotating the shoe member 26 connected to the piston 25 in the hydraulic cylinder 24 along the upper surface of the fixed swash plate member 27 to reciprocate. , A spherical portion is formed in the center portion so as to contact the spherical barrel at the lower end of the cylinder, and a groove is formed so that the shoe member 26 connected to the piston can be inserted in the circumference thereof, and is formed entirely of a curved elastic body. The groove portion to be fitted is characterized in that the shoe holder 28 is provided with one or more bends to add elasticity, Electro-hydraulic integrally controlled hybrid actuator system. The method of claim 1, The control system 80 includes a pressure sensor 81 for measuring the oil pressure in the hydraulic pipe 70 at the inlet of both the hydraulic chambers 63 and 64 of the actuator 60, and a piston in the cylinder 61 of the actuator 60. 62 is mounted on one end of the actuator, the position sensor 82 for measuring the relative position of the piston in the cylinder 61, and is configured to protrude in any one of the two hydraulic chambers (63) (64) Force sensor 83 for measuring the force generated at the time, the rotary encoder 84 for measuring the rotational speed of the servomotor 10, the pressure of the two hydraulic chambers 63, 64 measured by the pressure sensor 81, Servo motor by the position in the cylinder 61 of the piston 62 measured by the position sensor 82, the force measured by the force sensor 83 and the rotational speed of the servomotor 10 measured by the rotary encoder 84 Controller C, which controls forward / reverse rotation and rotational speed, stops / rotates, and amplifies a control signal of the controller C to the servomotor 10. It characterized by configured by an amplifier 85 for transmission, Electro-hydraulic integrally controlled hybrid actuator system.

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