Valve element position closed-loop control type hydraulic direction valve for aerial work machine

Abstract

The invention discloses a valve core position closed-loop control type hydraulic directional valve for high-altitude operation machinery, which belongs to the technical field of hydraulic directional valves and comprises a valve body, a valve core is arranged in the valve body, one end of the valve body is sealed, a spring is compressed between the valve core and one end of the valve body, and the other end of the valve body is communicated with an inner cavity of an outer shell; a direct-drive nut is connected into an inner cavity of the outer shell in a sliding mode, and the valve element is connected with the direct-drive nut. A motor is arranged in an inner cavity of the outer shell, a transmission assembly is arranged between the motor and the direct-drive nut, the motor is used for driving the direct-drive nut to do linear reciprocating motion, and a displacement sensor is fixedly embedded in the inner wall of the outer shell and right faces the side wall of the direct-drive nut. And the motor and the displacement sensor are electrically connected with the controller. Through real-time feedback of a closed-loop control system and the displacement sensor, the position control precision of the valve element is improved, meanwhile, vibration and noise generated in the movement process of the valve element are reduced, the system runs more stably, and the control method is particularly suitable for the fields such as high-altitude operation machines with high requirements for control precision and stability.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic directional valves, and in particular to a valve core position closed-loop control type hydraulic directional valve for aerial work machinery. Background Art

[0002] Hydraulic directional valves are widely used in aerial work machinery to control the direction of hydraulic fluid, thereby achieving the movement of mechanical arms or other working parts. Currently, common hydraulic directional valves often have disadvantages such as low control accuracy, large vibration, and high noise. Especially under high-precision, variable load and complex working conditions, they often cannot meet the requirements of aerial work machinery for precise control and stability.

[0003] Therefore, a valve core position closed-loop control type hydraulic directional valve for aerial work machinery is proposed. Summary of the invention

[0004] The object of the present invention is to provide a valve core position closed-loop control type hydraulic directional valve for aerial work machinery, aiming to solve or improve at least one of the above-mentioned technical problems.

[0005] To achieve the above-mentioned purpose, the present invention provides the following solution: The present invention provides a valve core position closed-loop control type hydraulic directional valve for aerial work machinery, comprising a valve body, a valve core is arranged in the valve body, one end of the valve body is sealed and a spring is pressed between the valve core, and the other end is connected to the inner cavity of the outer shell; a direct drive nut is slidably connected in the inner cavity of the outer shell, and the valve core is connected to the direct drive nut;

[0006] A motor is arranged in the inner cavity of the outer shell, a transmission assembly is arranged between the motor and the direct-drive nut, the motor is used to drive the direct-drive nut to move back and forth in a straight line, a displacement sensor is fixedly embedded on the inner wall of the outer shell, and the displacement sensor faces the side wall of the direct-drive nut; the motor and the displacement sensor are both electrically connected to the controller.

[0007] Preferably, a ball head is fixedly connected to one end of the valve core close to the direct-drive nut, and a ball head hole is formed at one end of the direct-drive nut close to the valve core, and the ball head is located in the ball head hole.

[0008] Preferably, one end of the inner cavity of the outer shell close to the valve core is a U-shaped channel, the displacement sensor is installed in the U-shaped channel, the radial cross-section of the direct-drive nut is U-shaped, the direct-drive nut is slidingly connected to the U-shaped channel, and a thread groove is provided at one end of the direct-drive nut away from the valve core, a transmission shaft is threadedly connected to the thread groove, the transmission shaft is rotatably connected to the inner cavity of the outer shell, and a reduction mechanism is provided between the transmission shaft and the output shaft of the motor.

[0009] Preferably, the reduction mechanism comprises a planet carrier fixedly sleeved on the outer wall of the transmission shaft, a plurality of planetary gears are circumferentially rotatably connected to the outer wall of the planet carrier, a sun gear is fixedly connected to the output shaft of the motor, and a plurality of planetary gears are wound around the sun gear and meshed with the sun gear;

[0010] An inner gear ring is fixedly connected in the inner cavity of the outer shell. The inner gear ring is sleeved outside the plurality of planetary gears, and the planetary gears are meshed with the inner gear ring.

[0011] Preferably, the outer shell includes a shell flange, a first shell, a second shell, a third shell and a top cover which are connected in sequence, the shell flange is a bolt structure, the shell flange is axially provided with the U-shaped channel, the screw on the shell flange is threadedly connected to the valve body, the nut end face of the shell flange is in contact with the valve body end face, and sealing rings are respectively sandwiched between the nut end face of the shell flange and the valve body end face, and between the valve core and the U-shaped channel.

[0012] Preferably, the inner ring gear is fixed to the inner wall of the second shell, the planetary carrier is located in the first shell, the motor is fixed in the third shell, and a plurality of bolts are threadedly connected on the top cover. The bolts sequentially penetrate the top cover, the third shell, the second shell, the first shell and are threadedly connected to the shell flange.

[0013] Preferably, a first shoulder is fixedly connected to the inner wall of the third shell at one end close to the second shell, the top cover is placed on the end surface of the motor away from its output shaft, and the boss on the motor housing is placed on the first shoulder.

[0014] Preferably, one end of the sun gear and the planetary gear close to the motor is attached to the end surface of the third housing in contact with the second housing.

[0015] Preferably, a bearing is arranged between the transmission shaft and the inner wall of the first shell, and the bearing is located at the end of the planetary carrier away from the motor. The outer ring of the bearing at the end away from the planetary carrier is pressed against the shoulder of the inner wall of the first shell, and the end of the planetary carrier close to the motor is pressed against the shoulder of the transmission shaft, and the other end is pressed against the end face of the bearing.

[0016] The present invention discloses the following technical effects: the present application drives the valve core to move left and right through a motor, and monitors the position of the valve core in real time through a displacement sensor while moving and feeds back the information to the controller. The controller adjusts the speed and direction of the motor, thereby realizing closed-loop control. Through closed-loop control, the small errors of the valve core can be continuously corrected to ensure that the valve core reaches the predetermined position accurately, thereby improving the control accuracy. Even in the case of load changes and pressure fluctuations in the hydraulic system, the system can still ensure stable control of the valve core. In this process, the spring provides the necessary resilience for the valve core on the one hand, and improves the motion characteristics of the valve core through the damping effect on the other hand, realizing smooth reversing, reducing vibration and noise, and improving the stability and dynamic performance of the valve core movement during the dynamic control of the valve core. It is suitable for applications with high requirements for noise control (especially for fields such as aerial work machinery that have high requirements for control accuracy and stability). BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the speed reduction mechanism in the present invention;

[0020] Figure 3 It is a schematic diagram of the structure of the direct-drive nut and the U-shaped channel in the present invention.

[0021] In the figure: 1. valve body; 2. valve core; 3. direct drive nut; 4. transmission shaft; 5. planetary carrier; 6. sun gear; 7. planetary gear; 8. motor; 9. controller; 10. displacement sensor; 11. bearing; 12. housing flange; 13. sealing ring; 14. bolt plug; 15. spring; 16. first housing; 17. second housing; 18. third housing; 19. top cover. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Reference Figure 1-Figure 3 The present invention provides a valve core position closed-loop control type hydraulic directional valve for aerial work machinery, comprising: a valve body 1, a valve core 2 is arranged in the valve body 1, one end of the valve body 1 is sealed and a spring 15 is pressed between the valve core 2, and the other end is connected to the inner cavity of the outer shell; a direct drive nut 3 is slidably connected in the inner cavity of the outer shell, and the valve core 2 is connected to the direct drive nut 3;

[0025] A motor 8 is arranged in the inner cavity of the outer shell, and a transmission assembly is arranged between the motor 8 and the direct-drive nut 3. The motor 8 is used to drive the direct-drive nut 3 to move back and forth in a straight line. A displacement sensor 10 is fixedly embedded on the inner wall of the outer shell, and the displacement sensor 10 is opposite to the side wall of the direct-drive nut 3; the motor 8 and the displacement sensor 10 are both electrically connected to the controller 9.

[0026] In this embodiment, a bolt plug 14 is threadedly connected to one end of the valve body 1 away from the outer shell, a sealing ring is installed between the bolt plug 14 and the valve body 1, a spring 15 is pressed between the bolt plug 14 and the valve core 2, and a gasket is arranged between the valve core 2 and the spring 15;

[0027] The present application drives the valve core 2 to move left and right through the motor 8, and monitors the displacement of the direct-drive nut 3 in real time through the displacement sensor 10 while moving, so that the position of the valve core 2 can be monitored and the information can be fed back to the controller 9, and the controller 9 adjusts the speed and direction of the motor 8, thereby realizing closed-loop control. Through closed-loop control, the small errors of the valve core 2 can be continuously corrected to ensure that the valve core 2 accurately reaches the predetermined position, and the control accuracy is improved; even in the case of load changes and pressure fluctuations in the hydraulic system, the system can still ensure stable control of the valve core. In this process, the spring 15 provides the necessary resilience for the valve core 2 on the one hand, and improves the motion characteristics of the valve core 2 through the damping effect on the other hand, so as to achieve smooth reversing, reduce vibration and noise, and improve the stability and dynamic performance of the valve core movement during the dynamic control of the valve core 2.

[0028] According to a further optimized solution, a ball head is fixedly connected to one end of the valve core 2 close to the direct drive nut 3, and a ball head hole is opened at one end of the direct drive nut 3 close to the valve core 2, and the ball head is located in the ball head hole.

[0029] A further optimized solution is that the end of the inner cavity of the outer shell close to the valve core 2 is a U-shaped channel, the displacement sensor 10 is installed in the U-shaped channel, the radial cross-section of the direct drive nut 3 is U-shaped, the direct drive nut 3 is slidingly connected to the U-shaped channel, and a thread groove is provided at the end of the direct drive nut 3 away from the valve core 2, and a transmission shaft 4 is threadedly connected in the thread groove, the transmission shaft 4 is rotatably connected to the inner cavity of the outer shell, and a reduction mechanism is arranged between the transmission shaft 4 and the output shaft of the motor 8.

[0030] The displacement sensor 10 is directly installed in the U-shaped channel to directly feedback the displacement of the valve core 2, thereby avoiding signal feedback errors caused by mechanical transmission errors and further improving control accuracy.

[0031] The U-shaped channel guides the movement of the direct-drive nut 3, and has a simple structure, low friction and wear, smoother transmission, and longer service life of the equipment. The ball head connection between the valve core 2 and the direct-drive nut 3 improves the flexibility of the mechanical connection and prevents the valve core from getting stuck due to installation errors; and even if the direct-drive nut 3 wears against the U-shaped channel after long-term use, causing the direct-drive nut 3 to rotate slightly, the valve core 2 will still maintain linear motion under the action of the ball head.

[0032] Further optimized solution, the speed reduction mechanism includes a planet carrier 5 fixedly sleeved on the outer wall of the transmission shaft 4, a plurality of planetary gears 7 are circumferentially connected to the outer wall of the planet carrier 5, a sun gear 6 is fixedly connected to the output shaft of the motor 8, and a plurality of planetary gears 7 are arranged around the sun gear 6 and meshed with the sun gear 6;

[0033] An inner gear ring is fixedly connected to the inner cavity of the outer shell. The inner gear ring is sleeved outside a plurality of planetary gears 7. The planetary gears 7 are meshed with the inner gear ring.

[0034] When in use, a command is issued through the controller 9 to start the drive motor 8, thereby driving the sun gear 6 to rotate, and under the action of the planetary gear 7, the transmission shaft 4 is driven to rotate. The transmission shaft 4 and the direct-drive nut 3 are threadedly rotated, causing the direct-drive nut 3 to produce a linear displacement, driving the valve core 2 to move left and right, thereby realizing the reversal of the hydraulic directional valve; the displacement sensor 10 feeds back the position of the valve core 2, and the controller 9 adjusts the motor 8 according to the feedback information, forming a closed-loop control system for the position of the valve core 2.

[0035] The closed-loop control system of the valve core 2 position can ensure that the valve core 2 maintains the neutral position when the system is closed, and realizes high-precision control of the valve core 2 position through the displacement sensor 10 and the controller 9, which can ensure that the system can still operate reliably during load fluctuations and electrical failures.

[0036] The planetary gear reducer reduces the transmission speed and increases the valve core driving force at the same time.

[0037] A further optimized solution is that the outer shell includes a shell flange 12, a first shell 16, a second shell 17, a third shell 18 and a top cover 19 which are connected in sequence. The shell flange 12 is a bolt structure. The shell flange 12 is provided with a U-shaped channel along the axial direction. The screw on the shell flange 12 is threadedly connected to the valve body 1. The nut end face of the shell flange 12 is in contact with the end face of the valve body 1. Sealing rings 13 are respectively sandwiched between the nut end face of the shell flange 12 and the end face of the valve body 1, and between the valve core 2 and the U-shaped channel.

[0038] To further optimize the solution, the inner ring gear is fixed to the inner wall of the second housing 17, the planetary carrier 5 is located in the first housing 16, the motor 8 is fixed in the third housing 18, and a plurality of bolts are threadedly connected to the top cover 19. The bolts pass through the top cover 19, the third housing 18, the second housing 17, the first housing 16 in sequence and are threadedly connected to the housing flange 12.

[0039] As a further optimization scheme, a first shoulder is fixedly connected to the inner wall of one end of the third shell 18 close to the second shell 17, the top cover 19 is pressed against the end face of the motor 8 away from its output shaft, and the boss on the outer shell of the motor 8 is pressed against the first shoulder.

[0040] This design enhances the stability of the overall structure and facilitates the installation, fixation and disassembly of the motor 8 and other components.

[0041] According to a further optimized solution, the ends of the sun gear 6 and the planetary gear 7 close to the motor 8 are attached to the end surfaces of the third housing 18 and the second housing 17 that are in contact with each other.

[0042] This makes the gear meshing stable.

[0043] A further optimized solution is that a bearing 11 is arranged between the transmission shaft 4 and the inner wall of the first housing 16. The bearing 11 is located at the end of the planetary carrier 5 away from the motor 8. The outer ring of the bearing 11 at the end away from the planetary carrier 5 is pressed against the shoulder of the inner wall of the first housing 16. The end of the planetary carrier 5 close to the motor 8 is pressed against the shoulder of the transmission shaft 4, and the other end is pressed against the end face of the bearing 11.

[0044] This design fixes the transmission shaft 4 and the planet carrier 5 axially, preventing the transmission shaft 4 from moving axially and affecting the displacement accuracy of the valve core.

[0045] In actual operation, the system works as follows:

[0046] 1. Initialization: When the system starts, the controller 9 sends a signal to the motor 8, the motor 8 starts and drives the reduction transmission shaft 4 to rotate through the planetary gear reducer. The valve core 2 starts to move under the drive of the U-shaped direct drive nut 3, ensuring that the valve core 2 is in the middle position.

[0047] 2. Adjustment of the position of the valve core 2: The motor 8 drives the U-shaped direct drive nut 3 to move linearly through the planetary gear reducer, so that the valve core 2 is displaced. At this time, the displacement sensor 10 feeds back the position change of the valve core 2 to the controller 9 in real time.

[0048] 3. Closed-loop control: The controller 9 adjusts the speed and direction of the motor 8 in real time according to the valve core position fed back by the displacement sensor 10. When the valve core 2 position reaches the target position, the controller 9 stops the motor 8 or slows down the speed of the motor 8 to complete the position adjustment.

[0049] 4. Position accuracy control: Through closed-loop control, the system can continuously correct the slight error of the valve core to ensure that the valve core reaches the predetermined position accurately. Even in the case of load changes and pressure fluctuations in the hydraulic system, the system can still ensure stable control of the valve core.

[0050] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0051] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A valve core position closed-loop control type hydraulic directional valve for aerial work machinery, characterized in that: The valve body (1) comprises a valve core (2) arranged in the valve body (1); one end of the valve body (1) is sealed and a spring (15) is pressed between the valve core (2); the other end of the valve body (1) is communicated with the inner cavity of an outer shell; a direct drive nut (3) is slidably connected in the inner cavity of the outer shell, and the valve core (2) is connected to the direct drive nut (3); A motor (8) is arranged in the inner cavity of the outer shell, a transmission assembly is arranged between the motor (8) and the direct-drive nut (3), the motor (8) is used to drive the direct-drive nut (3) to move back and forth in a straight line, a displacement sensor (10) is fixedly embedded on the inner wall of the outer shell, and the displacement sensor (10) faces the side wall of the direct-drive nut (3); the motor (8) and the displacement sensor (10) are both electrically connected to a controller (9).

2. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 1, characterized in that: A ball head is fixedly connected to one end of the valve core (2) close to the direct drive nut (3), and a ball head hole is opened at one end of the direct drive nut (3) close to the valve core (2), and the ball head is located in the ball head hole.

3. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 1, characterized in that: The end of the inner cavity of the outer shell body close to the valve core (2) is a U-shaped channel, the displacement sensor (10) is installed in the U-shaped channel, the radial cross-section of the direct drive nut (3) is U-shaped, the direct drive nut (3) is slidably connected to the U-shaped channel, and the end of the direct drive nut (3) away from the valve core (2) is provided with a thread groove, and a transmission shaft (4) is threadedly connected in the thread groove. The transmission shaft (4) is rotatably connected to the inner cavity of the outer shell body, and a speed reduction mechanism is provided between the transmission shaft (4) and the output shaft of the motor (8).

4. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 3, characterized in that: The speed reduction mechanism comprises a planet carrier (5) fixedly sleeved on the outer wall of the transmission shaft (4), a plurality of planetary gears (7) circumferentially rotatably connected to the outer wall of the planet carrier (5), a sun gear (6) fixedly connected to the output shaft of the motor (8), and a plurality of planetary gears (7) wound around the sun gear (6) and meshed with the sun gear (6); An inner gear ring is fixedly connected to the inner cavity of the outer shell, the inner gear ring is sleeved outside the plurality of planetary gears (7), and the planetary gears (7) are meshed with the inner gear ring.

5. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 4, characterized in that: The outer shell comprises a shell flange (12), a first shell (16), a second shell (17), a third shell (18) and a top cover (19) which are connected in sequence. The shell flange (12) is a bolt structure. The shell flange (12) is provided with the U-shaped channel along the axial direction. The screw on the shell flange (12) is threadedly connected to the valve body (1). The nut end face of the shell flange (12) contacts the end face of the valve body (1). A sealing ring (13) is respectively sandwiched between the nut end face of the shell flange (12) and the end face of the valve body (1), and between the valve core (2) and the U-shaped channel.

6. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 5, characterized in that: The inner gear ring is fixed to the inner side wall of the second housing (17), the planet carrier (5) is located in the first housing (16), the motor (8) is fixed in the third housing (18), and a plurality of bolts are threadedly connected to the top cover (19), the third housing (18), the second housing (17), the first housing (16) in sequence and are threadedly connected to the housing flange (12).

7. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 6, characterized in that: A first shoulder is fixedly connected to the inner wall of one end of the third shell (18) close to the second shell (17); the top cover (19) is pressed against the end surface of the motor (8) away from its output shaft; and the boss on the outer shell of the motor (8) is pressed against the first shoulder.

8. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 6, characterized in that: One end of the sun gear (6) and the planetary gear (7) close to the motor (8) is attached to the end surface of the third housing (18) in contact with the second housing (17).

9. The valve core position closed-loop control type hydraulic directional valve for aerial work machinery according to claim 6, characterized in that: A bearing (11) is arranged between the transmission shaft (4) and the inner wall of the first housing (16); the bearing (11) is located at the end of the planetary carrier (5) away from the motor (8); the outer ring of the end of the bearing (11) away from the planetary carrier (5) is pressed against the shoulder of the inner wall of the first housing (16); one end of the planetary carrier (5) close to the motor (8) is pressed against the shoulder of the transmission shaft (4), and the other end is pressed against the end face of the bearing (11).

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