A voice coil motor-driven dual-chamber pump-controlled actuator and its working method

Abstract

The present invention discloses a voice coil motor-driven double-chamber pump-controlled actuator and its working method, which relates to the field of electro-hydraulic actuators. The voice coil motor-driven double-chamber pump-controlled actuator includes: a piston, a pump cover plate, a pump head, a coil bobbin, a set screw nut, a permanent magnet, an isolation ring, a coil, an iron core, a core shaft, a housing, a displacement sensor, a rear plug, an accumulator, a hydraulic cylinder, a first one-way control valve, a second one-way control valve, a third one-way control valve, and a fourth one-way control valve. One piston and one pump head form two pump chambers. The piston is servo-driven by a voice coil motor, and the two pump chambers pump out flow at high frequency in parallel. Through the rectification of the one-way control valve, the hydraulic cylinder can move twice in one cycle, which can improve the power-to-weight ratio of the actuator.

Description

Technical Field

[0001] The present invention relates to the technical field of electro-hydraulic actuators, and in particular to a voice coil motor-driven double-chamber pump-controlled actuator and its working method. Background Art

[0002] In the aviation field, electro-hydraulic actuators are drive structures for aircraft control surface actuation, landing gear retraction and extension, engine fuel regulation, nozzle vector control, etc. At present, they are developing in the direction of integration. With the proposal of the concept of power-by-wire, electro-hydrostatic actuators have become a research hotspot, and their structure is a closed-loop local hydraulic volume control system highly integrated with motors, pumps, hydraulic valves, and hydraulic cylinders.

[0003] Patent 201911081525.1 discloses an intelligent material-driven double-pump integrated electro-hydrostatic actuator and its working method. This patent uses the design forms of double-pump series and parallel drives, which can improve the flow and pressure output performance of the actuator and achieve good results. However, the double-drive pump parallel structure occupies a large space layout, brings a large weight, and there is currently no structural form of a voice coil motor pump-controlled actuator. Summary of the Invention

[0004] In order to solve the above problems, the object of the present invention is to provide a voice coil motor-driven double-chamber pump-controlled actuator and its working method. A piston and a pump head form two pump chambers. The piston is servo-driven by a voice coil motor, and the two pump chambers pump out flow at high frequency in parallel. After rectification by one-way control valves, two movements of the hydraulic cylinder can be achieved in one cycle, which can improve the power-to-weight ratio of the actuator.

[0005] To achieve the above object, the voice coil motor-driven double-chamber pump-controlled actuator and its working method provided by the present invention adopt the following technical solutions:

[0006] A voice coil motor-driven double-chamber pump-controlled actuator includes: a piston, a pump cover plate, a pump head, a coil skeleton, a set screw nut, a permanent magnet, an isolation ring, a coil, an iron core, a core shaft, a housing, a displacement sensor, a rear plug, an accumulator, a hydraulic cylinder, a first one-way control valve, a second one-way control valve, a third one-way control valve, and a fourth one-way control valve;

[0007] The bottom end of the piston is fixedly connected to the coil skeleton through a set screw nut. The coil is wound outside the coil skeleton and is in clearance fit with the core shaft inside. The outside of the coil is in clearance fit with the inner hole of the isolation ring. The outside of the isolation ring is closely attached to the inside of the permanent magnet. The outside of the permanent magnet is closely attached to the inner hole of the housing. The core shaft is press-fitted into the inner hole of the housing. The displacement sensor is installed in the inner hole of the core shaft through a thread. The upper end of the iron core is threadedly connected to the piston, and the lower end is placed in the inner hole of the displacement sensor. The housing is connected to the pump head by screws, and the pump cover plate is installed in the inner hole of the pump head through a thread;

[0008] The area between the piston and the bottom surface of the inner hole of the pump head forms a first pump chamber. A first oil outlet and a first oil inlet are provided in the first pump chamber. The first oil outlet is communicated with the high-pressure chamber of the hydraulic cylinder through a first one-way control valve, and the first oil inlet is communicated with the low-pressure chamber of the hydraulic cylinder through a second one-way control valve;

[0009] The area between the piston and the pump cover plate forms a second pump chamber. A second oil outlet and a second oil inlet are provided in the second pump chamber. The second oil outlet is communicated with the high-pressure chamber of the hydraulic cylinder through a third one-way control valve, and the second oil outlet is communicated with the low-pressure chamber of the hydraulic cylinder through a fourth one-way control valve;

[0010] Further, the first one-way control valve and the third one-way control valve have the same function, and the second one-way control valve and the fourth one-way control valve have the same function. They can be either passive one-way valves or active one-way valves or high-speed switching valves;

[0011] Further, the first one-way control valve only allows the oil fluid to flow from the first oil outlet to the high-pressure chamber and is cutoff in the reverse direction. The second one-way control valve allows the oil fluid to flow from the low-pressure chamber to the first oil inlet and is cutoff in the reverse direction. The third one-way control valve allows the oil fluid to flow from the second oil outlet to the high-pressure chamber and is cutoff in the reverse direction. The fourth one-way control valve allows the oil fluid to flow from the low-pressure chamber to the second oil inlet and is cutoff in the reverse direction;

[0012] Further, the accumulator is installed on the oil path connecting the high-pressure chamber for providing a system bias voltage. Further, the inner ring of the magnet has an N-pole polarity and the outer ring has an S-pole polarity;

[0013] Further, when a positive electric signal is applied to the coil, a magnetic field with the N pole facing down and the S pole facing up is generated. When a negative electric signal is applied, a magnetic field with the S pole facing down and the N pole facing up is generated;

[0014] The present invention also discloses a working method of a voice coil motor-driven double-chamber actuator, which is as follows:

[0015] When a positive signal in a period is given to the coil, according to the Ampere's force rule, the coil receives an Ampere's force upward along the axial direction of the coil. The coil bobbin drives the piston to move upward. The volume of the first pump chamber becomes smaller, and the fluid is discharged through the first oil outlet and the one-way control valve and enters the high-pressure chamber, causing the hydraulic cylinder to move to the right. The volume of the second pump chamber becomes larger, and the fluid in the low-pressure chamber is sucked into the second pump chamber through the one-way control valve and the second oil inlet. The whole process completes one actuation of the hydraulic cylinder, and the displacement sensor real-time feedbacks the position information of the piston in the pump chamber;

[0016] When a negative signal is given to the coil in a cycle, according to Ampere's force rule, the coil is subjected to an Ampere force downward along the axial direction of the coil. The coil skeleton drives the piston to move downward, the volume of the second pump chamber becomes smaller, and the fluid is discharged through the second oil outlet and the one-way control valve and enters the high-pressure chamber, causing the hydraulic cylinder to move to the right. The volume of the first pump chamber becomes larger, and the fluid in the low-pressure chamber is sucked into the first pump chamber through the one-way control valve and the second oil inlet. The entire process completes one actuation of the hydraulic cylinder, and the displacement sensor real-time feedbacks the position information of the pump chamber piston.

[0017] During the working process, the controller real-time collects the piston position signal real-time feedbacked by the displacement sensor and the displacement signal of the output rod of the hydraulic cylinder. Among them, the pump output flow is adjusted through the pump chamber piston position information, and the output displacement of the actuator is adjusted through the displacement signal of the output rod, constituting a double closed-loop control.

[0018] To sum up the above two movement processes, under the positive and negative signals of one cycle, the piston moves twice, completes two oil suction and discharge operations, and the hydraulic cylinder moves twice.

[0019] Compared with the existing actuator structure, the present invention has the following advantages:

[0020] (1) Using a voice coil motor as the drive to improve the response speed;

[0021] (2) Using a displacement sensor to real-time feedback the position to improve the control accuracy;

[0022] (3) Adopting a single piston to achieve the driving effect of a double pump, with a compact and simple structure and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the actuator structure. DETAILED DESCRIPTION OF THE INVENTION

[0024] In order to more intuitively and clearly describe the structural principle and working method in the embodiments of the present invention, the following will introduce the embodiments in combination with the relevant drawings. The drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0025] The embodiment of the present invention provides a voice coil motor-driven double-chamber pump-controlled actuator and its working method. The piston and the pump head form a double chamber. The piston is servo-driven by a voice coil motor. The two pump chambers alternately pump out the flow, which is rectified by a one-way control valve, and two movements of the hydraulic cylinder are realized in one cycle, which can improve the power-to-weight ratio of the actuator.

[0026] To achieve the above object, the embodiment of the present invention adopts the following technical solutions:

[0027] A voice coil motor-driven double-chamber pump-controlled actuator, as shown in Figure 1 the figure, includes: piston 1, pump cover plate 2, pump head 3, coil bobbin 4, set screw 5, permanent magnet 6, spacer ring 7, coil 8, iron core 9, core shaft 10, housing 11, displacement sensor 12, rear plug 13, accumulator 14, hydraulic cylinder 15, first one-way control valve 17, second one-way control valve 18, third one-way control valve 16, fourth one-way control valve 19;

[0028] The bottom end of the piston 1 is fixedly connected to the coil bobbin 4 through the set screw 5. The coil 8 is wound around the outer side of the coil bobbin 4 and is in clearance fit with the core shaft 10 on the inner side. The outer side of the coil 8 is in clearance fit with the inner hole of the spacer ring 7. The outer side of the spacer ring 7 is closely attached to the inner side of the permanent magnet 6. The outer side of the permanent magnet 6 is closely attached to the inner hole of the housing 11. The core shaft 10 is press-fitted into the inner hole of the housing 11. The displacement sensor 12 is installed in the inner hole of the core shaft 10 by means of a thread. The upper end of the iron core 9 is threadedly connected to the piston 1, and the lower end is placed in the inner hole of the displacement sensor 12. The housing 11 and the pump head 3 are connected by screws. The pump cover plate 2 is installed in the inner hole of the pump head 3 by means of a thread;

[0029] The area between the piston 1 and the bottom surface of the inner hole of the pump head 3 forms a first pump chamber I. The first pump chamber I is provided with a first oil outlet 3.2 and a first oil inlet 3.3. The first oil outlet 3.2 is communicated with the high-pressure chamber 15.1 of the hydraulic cylinder 15 through the first one-way control valve 17. The first oil inlet 3.3 is communicated with the low-pressure chamber 15.2 of the hydraulic cylinder 15 through the second one-way control valve 18;

[0030] The area between the piston 1 and the pump cover plate 2 forms a second pump chamber II. The second pump chamber II is provided with a second oil outlet 3.1 and a second oil inlet 3.4. The second oil outlet 3.1 is communicated with the high-pressure chamber 15.1 of the hydraulic cylinder 15 through the third one-way control valve 16. The second oil inlet 3.4 is communicated with the low-pressure chamber 15.2 of the hydraulic cylinder 15 through the fourth one-way control valve 19;

[0031] The first one-way control valve 17 and the third one-way control valve 16 have the same function. The second one-way control valve 18 and the fourth one-way control valve 19 have the same function. They can be either passive one-way valves or active one-way valves or high-speed switching valves;

[0032] The first one-way control valve 17 only allows the oil to flow from the first oil outlet 3.2 to the high-pressure chamber 15.1 and is cut off in the reverse direction. The second one-way control valve 18 allows the oil to flow from the low-pressure chamber 15.2 to the first oil inlet 3.3 and is cut off in the reverse direction. The third one-way control valve 16 allows the oil to flow from the second oil outlet 3.1 to the high-pressure chamber 15.1 and is cut off in the reverse direction. The fourth one-way control valve 19 allows the oil to flow from the low-pressure chamber 15.2 to the second oil inlet 3.4 and is cut off in the reverse direction;

[0033] The accumulator 14 is installed on the oil path connecting to the high-pressure chamber 15.1 and is used to give a system bias voltage.

[0034] The inner ring of the permanent magnet 6 has an N-pole polarity and the outer ring has an S-pole polarity.

[0035] When a positive electrical signal is applied to the coil 8, a magnetic field with the N pole facing down and the S pole facing up is generated. When a negative electrical signal is applied, a magnetic field with the S pole facing down and the N pole facing up is generated.

[0036] The present invention also discloses a working method of a voice coil motor-driven double-chamber actuator, which is as follows:

[0037] When a positive signal in a cycle is given to the coil 8, according to the Ampere's force rule, the coil 8 receives an Ampere's force upward along the axial direction of the coil. The coil bobbin 4 drives the piston 1 to move upward. The volume of the first pump chamber Ⅰ becomes smaller, and the fluid is discharged through the first oil outlet 3.2 and the one-way control valve 17 and enters the high-pressure chamber 15.1, causing the hydraulic cylinder 15 to move to the right. The volume of the second pump chamber Ⅱ becomes larger, and the fluid in the low-pressure chamber 15.2 is sucked into the second pump chamber Ⅱ through the one-way control valve 19 and the second oil inlet 3.4. The whole process completes one actuation of the hydraulic cylinder 15, and the position sensor 12 feeds back the position information in real time.

[0038] When a negative signal in a cycle is given to the coil 8, according to the Ampere's force rule, the coil 8 receives an Ampere's force downward along the axial direction of the coil. The coil bobbin 4 drives the piston 1 to move downward. The volume of the second pump chamber Ⅱ becomes smaller, and the fluid is discharged through the second oil outlet 3.1 and the one-way control valve 16 and enters the high-pressure chamber 15.1, causing the hydraulic cylinder 15 to move to the right. The volume of the first pump chamber Ⅰ becomes larger, and the fluid in the low-pressure chamber 15.2 is sucked into the first pump chamber Ⅰ through the one-way control valve 18 and the second oil inlet 3.3. The whole process completes one actuation of the hydraulic cylinder 15, and the position sensor 12 feeds back the position information in real time.

[0039] In summary of the above two movement processes, under the positive and negative signals in one cycle, the piston 1 moves twice, completing two suction and discharge operations of oil, and the hydraulic cylinder 15 moves twice.

[0040] Compared with the existing actuator structure, the present invention has the following advantages:

[0041] (1) Using a voice coil motor as the drive to improve the response speed;

[0042] (2) Using a position sensor to feed back the position in real time to improve the control accuracy;

[0043] (3) Using one piston to achieve the driving effect of a double pump, with a compact and simple structure and high efficiency.

[0044] The present invention has been described in detail above in connection with the accompanying drawings of the specification or specific embodiments. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described and these examples should not be construed as being limited to the examples set forth herein. On the contrary, these examples are described so as to better illustrate the positive effects of the present invention. Those parts not elaborated in this text are regarded as well-known techniques or conventional technical means in the art.

Claims

1. A voice coil motor-driven double-chamber pump-controlled actuator, characterized in that, Including: Piston (1), pump cover plate (2), pump head (3), coil bobbin (4), set screw nut (5), permanent magnet (6), isolation ring (7), coil (8), iron core (9), mandrel (10), housing (11), displacement sensor (12), rear plug (13), accumulator (14), hydraulic cylinder (15), first one-way control valve (17), second one-way control valve (18), third one-way control valve (16), fourth one-way control valve (19); The bottom end of the piston (1) is fixedly connected to the coil bobbin (4) through the set screw nut (5). The coil (8) is wound around the outside of the coil bobbin (4) and has a clearance fit with the mandrel (10) on the inside. The outside of the coil (8) has a clearance fit with the inner hole of the isolation ring (7). The outside of the isolation ring (7) is in close contact with the inside of the permanent magnet (6). The outside of the permanent magnet (6) is in close contact with the inner hole of the housing (11). The mandrel (10) is press-fitted into the inner hole of the housing (11). The displacement sensor (12) is installed in the inner hole of the mandrel (10) by threading. The upper end of the iron core (9) is threadedly connected to the piston (l), and the lower end is placed in the inner hole of the displacement sensor (12). The housing (11) is connected to the pump head (3) by screws. The pump cover plate (2) is installed in the inner hole of the pump head (3) by threading; The area between the piston (1) and the bottom surface of the inner hole of the pump head (3) forms a first pump chamber (Ⅰ). A first oil outlet (3.2) and a first oil inlet (3.3) are provided in the first pump chamber (Ⅰ). The first oil outlet (3.2) is communicated with the high-pressure chamber (15.1) of the hydraulic cylinder (15) through the first one-way control valve (17). The first oil inlet (3.3) is communicated with the low-pressure chamber (15.2) of the hydraulic cylinder (15) through the second one-way control valve (18); The area between the piston (1) and the pump cover plate (2) forms a second pump chamber (Ⅱ). A second oil outlet (3.1) and a second oil inlet (3.4) are provided in the second pump chamber (Ⅱ). The second oil outlet (3.1) is communicated with the high-pressure chamber (15.1) of the hydraulic cylinder (15) through the third one-way control valve (16). The second oil outlet (3.1) is communicated with the low-pressure chamber (15.2) of the hydraulic cylinder (15) through the fourth one-way control valve (19).

2. The voice coil motor-driven double-chamber pump-controlled actuator according to claim 1, characterized in that, The first one-way control valve (17) and the third one-way control valve (16) have the same function. The second one-way control valve (18) and the fourth one-way control valve (19) have the same function.

3. The voice coil motor-driven double-chamber pump-controlled actuator according to claim 2, wherein The four one-way control valves are passive one-way valves, active one-way valves or high-speed switching valves.

4. The voice coil motor-driven double-chamber pump-controlled actuator according to claim 3, characterized in that The first one-way control valve (17) only allows the oil fluid to flow from the first oil outlet (3.2) to the high-pressure chamber (15.1) and is cut off in the reverse direction. The second one-way control valve (18) allows the oil fluid to flow from the low-pressure chamber (15.2) to the first oil inlet (3.3) and is cut off in the reverse direction. The third one-way control valve (16) allows the oil fluid to flow from the second oil outlet (3.1) to the high-pressure chamber (15.1) and is cut off in the reverse direction. The fourth one-way control valve (19) allows the oil fluid to flow from the low-pressure chamber (15.2) to the second oil inlet (3.4) and is cut off in the reverse direction.

5. The voice coil motor-driven double-chamber pump-controlled actuator according to claim 1, characterized in that, The accumulator (14) is installed on the oil path connecting to the high-pressure chamber (15.1) and is used to provide a system bias voltage.

6. The voice coil motor-driven double-chamber pump-controlled actuator according to claim 1, characterized in that, The inner ring of the magnetic steel (6) has an N-pole polarity, and the outer ring has an S-pole polarity.

7. The voice coil motor-driven double-chamber pump-controlled actuator according to claim 1, wherein When a positive electrical signal is applied to the coil (8), a magnetic field with the N pole facing down and the S pole facing up is generated. When a negative electrical signal is applied, a magnetic field with the S pole facing down and the N pole facing up is generated.

8. A working method of a voice coil motor-driven double-chamber pump control actuator according to any one of claims 1-7, characterized in that, The first pump chamber (Ⅰ) and the second pump chamber (Ⅱ) alternately pump out flow in parallel, and the hydraulic cylinder (15) moves twice in one cycle, specifically as follows: When the coil (8) is given a positive signal in a cycle, according to the Ampere's force rule, the coil (8) receives an Ampere's force upward along the axial direction of the coil. The coil skeleton (4) drives the piston (1) to move upward. The volume of the first pump chamber (Ⅰ) becomes smaller, and the fluid is discharged through the first oil outlet (3.2) and the first one-way control valve (17) and enters the high-pressure chamber (15.1), causing the hydraulic cylinder (15) to move to the right. The volume of the second pump chamber (Ⅱ) becomes larger, and the fluid in the low-pressure chamber (15.2) is sucked into the second pump chamber (Ⅱ) through the fourth one-way control valve (19) and the second oil inlet (3.4). The entire process completes one actuation of the hydraulic cylinder (15), and the position sensor (12) provides real-time feedback of the position information. When the coil (8) is given a negative signal in a cycle, according to the Ampere's force rule, the coil (8) receives an Ampere's force downward along the axial direction of the coil. The coil skeleton (4) drives the piston (1) to move downward. The volume of the second pump chamber (Ⅱ) becomes smaller, and the fluid is discharged through the second oil outlet (3.1) and the third one-way control valve (16) and enters the high-pressure chamber (15.1), causing the hydraulic cylinder (15) to move to the right. The volume of the first pump chamber (Ⅰ) becomes larger, and the fluid in the low-pressure chamber (15.2) is sucked into the first pump chamber (Ⅰ) through the second one-way control valve (18) and the second oil inlet (3.4). The entire process completes one actuation of the hydraulic cylinder (15), and the position sensor (12) provides real-time feedback of the position information. Under the positive and negative signals in one cycle, the piston (1) moves twice, completing two oil suction and discharge processes, and the hydraulic cylinder (15) moves twice.

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