Electrohydraulic servo cylinder driven by linear motor
By combining linear motors with hydraulic cylinders and using electromagnetic drive to directly control hydraulic cylinder pistons, the complexity of traditional hydraulic cylinder control system and insufficient output force of linear motors is solved, the combination of high response speed and large thrust is achieved, and the system is enhanced anti-pollution capacity and adaptability range.
Patent Information
- Application Number
- CN202422943765.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-12-02
AI Technical Summary
The control system of traditional hydraulic cylinders is complex and has a hysteresis, making it difficult to achieve the combination of high response speed and large thrust, and the position accuracy and response speed of linear motors are also difficult to amplify the output force.
Combine the linear motor with the hydraulic cylinder, and directly control the action of the hydraulic cylinder piston through position signals. Use the electromagnetic drive part and the hydraulic part to drive the valve core to slide with the magnetic steel jacket and coil winding to achieve the extension and retraction of the piston rod. Simplify the control system.
It improves the control response speed of the hydraulic cylinder, amplifies the output force of the linear motor, reduces the equipment volume, and enhances the anti-pollution ability and adaptability range.
Smart Images
Figure CN222296618U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of servo actuators, in particular to an electro-hydraulic servo cylinder driven by a linear motor. Background Art
[0002] Both hydraulic cylinders and linear motors are devices for achieving linear motion. The advantage of hydraulic cylinders is that they can output greater thrust under the same volume, and the advantage of linear motors is that they have higher positioning accuracy and response speed. Conventional hydraulic cylinders achieve fixed piston rod position by controlling the on and off of a control valve when the preset position is reached. The process of achieving position feedback requires a complex control system, and there is lag in the process of multi-stage servo control through hydraulic valves. Therefore, the utility model proposes a new technical solution, combining the principles of linear motors with those of hydraulic cylinders, and directly controlling the movement of the hydraulic cylinder piston through position signals, which not only improves the control response speed of the hydraulic cylinder but also amplifies the output force of the linear motor, thereby combining the advantages of the two. Utility Model Content
[0003] In view of the above technical problems, the technical solution adopted by the utility model is: a linear motor-driven electro-hydraulic servo cylinder, including a hydraulic part and an electromagnetic drive part, the hydraulic part including a hydraulic cylinder housing, a piston, and a piston rod, the piston is arranged inside the hydraulic cylinder housing, the piston is fixedly connected to the piston rod, a valve core is arranged inside the piston, the electromagnetic drive part includes a first part arranged inside the piston rod and a second part arranged on the hydraulic cylinder housing, the first part is fixedly connected to the valve core, the first part and the second part cooperate to drive the valve core to slide inside the piston, and then to control the extension and retraction of the piston rod.
[0004] Furthermore, a slide is arranged inside the piston, the valve core is arranged inside the slide, the piston divides the internal area of the hydraulic cylinder housing into a rod chamber and a rodless chamber, the piston is provided with a first oil circuit for connecting the slide with the rod chamber and a second oil circuit for connecting the slide with the rodless chamber, the piston is also provided with a connecting oil circuit for connecting the slides located on both sides of the valve core end face, and the piston rod is provided with an oil supply circuit and an oil return circuit connected to the slide inside the piston.
[0005] Furthermore, the first part of the electromagnetic drive part includes a magnetic steel jacket, the interior of the piston rod is set as a hollow structure, the magnetic steel jacket is set in the hollow structure of the piston rod, the magnetic steel jacket is fixedly connected to the valve core, and multiple magnets are set inside the magnetic steel jacket.
[0006] Furthermore, the second part of the electromagnetic drive part includes a coil winding, which is fixedly mounted on the hydraulic cylinder housing and arranged on the outside of the first part. The coil winding includes a winding A and a winding B. The winding directions of winding A and winding B are opposite. Winding A is provided with one group and winding B is provided with two groups. The coils of winding A and winding B are arranged in sequence.
[0007] Furthermore, two surfaces close to each other between two adjacent magnetic steels inside the magnetic steel housing are set to have the same magnetic poles.
[0008] Furthermore, the diameters of the two end portions of the valve core are larger than the diameter of the middle portion, and the diameters of the two end portions are equal to the inner diameter of the slideway inside the piston.
[0009] The beneficial effects of the utility model compared with the prior art are: the technical solution of the utility model combines the principles of linear motors and hydraulic cylinders, and directly controls the stroke of the hydraulic cylinder piston by controlling the stroke of the valve core. Compared with the traditional hydraulic valve control system, the size of the equipment is reduced. At the same time, since the utility model only requires one-level servo to realize the control of the electro-hydraulic servo cylinder, the response speed is improved. In addition, compared with linear motors, the output thrust is amplified. Finally, compared with the traditional electro-hydraulic servo system, the technical solution of this case has stronger anti-pollution ability and a wider range of adaptability. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a sectional view of the overall structure of the utility model.
[0011] Figure 2 It is a schematic diagram of the internal structure of the utility model when working.
[0012] Figure numbers: 1-hydraulic cylinder housing; 2-piston; 3-first oil circuit; 4-piston rod; 5-coil winding; 501-winding A; 502-winding B; 6-oil supply circuit; 7-magnetic steel jacket; 8-magnet; 9-oil return circuit; 10-rod chamber; 11-connecting oil circuit; 12-second oil circuit; 13-rodless chamber; 14-valve core. DETAILED DESCRIPTION
[0013] The technical solution of the utility model is further described below in conjunction with the accompanying drawings.
[0014] Example: Figure 1-Figure 2As shown, a linear motor-driven electro-hydraulic servo cylinder includes a hydraulic part and an electromagnetic drive part. The hydraulic part includes a hydraulic cylinder housing 1, a piston 2, and a piston rod 4. The piston 2 is arranged inside the hydraulic cylinder housing 1. The piston 2 is fixedly connected to the piston rod 4. A valve core 14 is arranged inside the piston 2. The electromagnetic drive part includes a first part arranged inside the piston rod 4 and a second part arranged on the hydraulic cylinder housing 1. The first part is fixedly connected to the valve core 14. The first part and the second part cooperate to drive the valve core 14 to slide inside the piston 2, thereby controlling the extension and retraction of the piston rod 4.
[0015] A slide is arranged inside the piston 2, and a valve core 14 is arranged inside the slide. The piston 2 divides the internal area of the hydraulic cylinder housing 1 into a rod chamber 10 and a rodless chamber 13. A first oil circuit 3 for connecting the slide with the rod chamber 10 and a second oil circuit 12 for connecting the slide with the rodless chamber 13 are arranged inside the piston 2. A connecting oil circuit 11 for connecting the slides located on both sides of the end face of the valve core 14 is also arranged inside the piston 2. An oil supply circuit 6 and an oil return circuit 9 connected with the internal slide of the piston 2 are arranged inside the piston rod 4. The diameter of the two end parts of the valve core 14 is larger than the diameter of the middle part, and the diameter of the two end parts is equal to the inner diameter of the slide inside the piston 2.
[0016] The first part of the electromagnetic drive part includes a magnetic steel jacket 7. The interior of the piston rod 4 is set as a hollow structure. The magnetic steel jacket 7 is set in the hollow structure of the piston rod 4. The magnetic steel jacket 7 is fixedly connected to the valve core 14. A plurality of magnets 8 are set inside the magnetic steel jacket 7. The two surfaces close to each other between two adjacent magnets 8 inside the magnetic steel jacket 7 are set as the same magnetic poles.
[0017] The second part of the electromagnetic drive part includes a coil winding 5, which is fixedly mounted on the hydraulic cylinder housing 1. The coil winding 5 is arranged on the outside of the first part. The coil winding 5 includes a winding A501 and a winding B502. The winding directions of the winding A501 and the winding B502 are opposite. The winding A501 is provided with one group, and the winding B502 is provided with two groups. The coils of the winding A501 and the winding B502 are arranged in sequence.
[0018] The working principle of a linear motor-driven electro-hydraulic servo cylinder disclosed in the utility model is as follows: the oil supply circuit 6 and the oil return circuit 9 arranged inside the piston rod 4 are connected to the external oil circuit system through the piston rod 4. When the piston rod 4 needs to extend outward, the coil winding 5 is energized to enable it. The alternating magnetic field generated by the coil winding 5 after being energized is coupled with the magnetic field generated by the plurality of magnetic steels 8, driving the magnetic steel jacket 7 to slide inside the piston rod 4 in a direction away from the hydraulic cylinder housing 1. The valve core 14 can be set to positive cover, negative cover and zero cover inside the slideway. In this embodiment, zero cover is shown, such as Figure 2As shown, at this time, the slide is connected with the first oil circuit 3 and the second oil circuit 12, and the hydraulic oil delivered through the oil supply circuit 6 is delivered to the rodless chamber 13 through the slide and the second oil circuit 12. At this time, the pressure inside the rodless chamber 13 is greater than the pressure inside the rod chamber 10, so the piston 2 is pushed to slide in the direction of the rod chamber 10, and the oil inside the rod chamber 10 flows out through the first oil circuit 3, the slide, the connecting oil circuit 11 and the return oil circuit 9. The electromagnetic drive part reflects the distance moved by the magnetic steel jacket 7 relative to the coil winding 5 through the encoder. When the encoder detects that the distance moved by the magnetic steel jacket 7 is the same as the stroke required for the piston rod 4 to move, the magnetic steel jacket 7 stops moving. After the magnetic steel jacket 7 stops moving, the piston rod 4 and the piston 2 will continue to move until the channel between the slide and the valve core 14 is closed, completing the servo process. At this time, the state of the electro-hydraulic servo cylinder is as shown in FIG. Figure 1 As shown, when the piston rod 4 is subjected to external force and slides toward the inside of the hydraulic cylinder housing 1, since the position of the magnetic steel jacket 7 remains unchanged, the internal structure of the electro-hydraulic servo cylinder is as follows: Figure 2 As shown, the first oil circuit 3 and the second oil circuit 12 are connected with the slideway, and the oil now flows into the rodless chamber 13 through the oil supply circuit 6, driving the piston rod 4 to extend to the outside of the hydraulic cylinder housing 1 until the first oil circuit 3 and the second oil circuit 12 and the slideway are closed again, thereby fixing the position of the piston rod 4; according to the hydraulic principle, the stroke traveled by the magnetic steel jacket 7 is the length of the extension of the piston rod 4. When the piston rod 4 needs to be retracted, the magnetic steel jacket 7 is driven to slide in the direction close to the hydraulic cylinder housing 1, and the above-mentioned action process is repeated to achieve the retraction.
Claims
1. An electro-hydraulic servo cylinder driven by a linear motor, characterized in that: The invention comprises a hydraulic part and an electromagnetic drive part, wherein the hydraulic part comprises a hydraulic cylinder housing (1), a piston (2), and a piston rod (4), wherein the piston (2) is arranged inside the hydraulic cylinder housing (1), the piston (2) is fixedly connected to the piston rod (4), a valve core (14) is arranged inside the piston (2), and the electromagnetic drive part comprises a first part arranged inside the piston rod (4) and a second part arranged on the hydraulic cylinder housing (1), wherein the first part is fixedly connected to the valve core (14), and the first part cooperates with the second part to drive the valve core (14) to slide inside the piston (2), thereby controlling the extension and retraction of the piston rod (4); The first part of the electromagnetic drive part comprises a magnetic steel jacket (7), the interior of the piston rod (4) is arranged as a hollow structure, the magnetic steel jacket (7) is arranged in the hollow structure of the piston rod (4), the magnetic steel jacket (7) is fixedly connected to the valve core (14), and a plurality of magnetic steels (8) are arranged inside the magnetic steel jacket (7); The second part of the electromagnetic drive part comprises a coil winding (5), the coil winding (5) is fixedly mounted on the hydraulic cylinder housing (1), the coil winding (5) is arranged outside the first part, the coil winding (5) comprises a winding A (501) and a winding B (502), the winding directions of the winding A (501) and the winding B (502) are opposite, the winding A (501) is provided with one group, the winding B (502) is provided with two groups, and the coils of the winding A (501) and the winding B (502) are arranged in sequence.
2. The electro-hydraulic servo cylinder driven by a linear motor according to claim 1, characterized in that: The piston (2) is provided with a slideway inside, the valve core (14) is provided inside the slideway, the piston (2) divides the internal area of the hydraulic cylinder housing (1) into a rod chamber (10) and a rodless chamber (13), the piston (2) is provided with a first oil circuit (3) for realizing communication between the slideway and the rod chamber (10) and a second oil circuit (12) for realizing communication between the slideway and the rodless chamber (13), the piston (2) is also provided with a connecting oil circuit (11) for connecting the slideways located on both sides of the end surface of the valve core (14), and the piston rod (4) is provided with an oil supply circuit (6) and an oil return circuit (9) for communicating with the internal slideway of the piston (2).
3. The electro-hydraulic servo cylinder driven by a linear motor according to claim 1, characterized in that: Two surfaces close to each other between two adjacent magnetic steels (8) inside the magnetic steel jacket (7) are arranged to have the same magnetic poles.
4. The electro-hydraulic servo cylinder driven by a linear motor according to claim 1, characterized in that: The diameters of the two end portions of the valve core (14) are larger than the diameter of the middle portion, and the diameters of the two end portions are equal to the inner diameter of the internal slideway of the piston (2).