Electric cylinder capable of automatically resetting

Abstract

The utility model relates to the technical field of electric cylinders, in particular to an automatic reset electric cylinder which comprises a cylinder barrel and a piston rod, and the piston rod is inserted into the cylinder barrel and is in sliding connection with the cylinder barrel in the axial direction of the cylinder barrel; the spring seat is arranged on the outer side of the cylinder barrel; the gland is arranged at the end, located outside the cylinder barrel, of the piston rod. And the reset spring is arranged outside the cylinder barrel in a sleeving manner, and the reset spring is arranged between the spring seat and the gland. The reset spring is arranged between the bottom of the cylinder barrel of the electric cylinder and the rod head of the piston rod, the reset spring directly acts on reset of the piston rod, rapid reset of the whole electric cylinder can be achieved, and the reset efficiency of the electric cylinder is improved.

Description

Technical Field

[0001] The present application relates to the technical field of electric cylinders, and in particular to an electric cylinder capable of automatically resetting. Background Art

[0002] Hydraulic cylinders are commonly used linear actuating devices. For example, when a ship docks at a port, it needs to drop anchor. During the anchoring process, it is necessary to control the anchor chain wheel to control the anchoring depth, and control the mooring drum to fix the cable to tie the hull.

[0003] The existing anchoring operation is generally completed by a hydraulic cylinder, but the hydraulic cylinder needs to be equipped with oil pipes, pumps, and valves, and it is easy for the oil pipes and cylinders to leak internally or externally, which can easily pollute the water system. It also requires professional maintenance. In addition, the hydraulic oil will also be affected by seasonal changes, and its physical properties will also change. The overall cost is high and it is inconvenient to use and maintain. Therefore, in these special working conditions, electric cylinders are required for driving.

[0004] In order to improve working efficiency, a buffer and reset structure is provided in the electric cylinder. Usually, the electric cylinder adopts the combination of a screw and a nut to drive the linear movement of a piston rod connected to the nut. The reset structure in the existing electric cylinder is usually provided on the lead screw to control the rotation of the lead screw to automatically reset, thereby realizing rapid reset of the piston rod. This reset method of indirectly controlling the reset of the piston rod by controlling the reset of the lead screw has low reset efficiency, and the reset rotation of the screw can easily cause the piston rod to stall, resulting in a reduced service life of the electric cylinder. Utility Model Content

[0005] The technical problem to be solved by the utility model is that the existing electric cylinder realizes the overall resetting of the electric cylinder by partially automatically resetting the screw rod, and the resetting efficiency is low.

[0006] To this end, the utility model provides an electric cylinder which can automatically reset.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] An electric cylinder capable of automatically resetting, comprising

[0009] Cylinder, and

[0010] A piston rod, the piston rod is inserted into the cylinder barrel and is slidably connected to the cylinder barrel along the axial direction of the cylinder barrel;

[0011] A spring seat, the spring seat being arranged outside the cylinder;

[0012] A gland, the gland being arranged on one end of the piston rod outside the cylinder;

[0013] A return spring, wherein the return spring is sleeved outside the cylinder and arranged between the spring seat and the pressure cover;

[0014] By adopting the above technical solution, the reset spring is arranged between the bottom of the cylinder barrel of the electric cylinder and the head of the piston rod. The reset spring directly acts on the reset of the piston rod, which can realize the rapid reset of the electric cylinder as a whole and improve the reset efficiency of the electric cylinder.

[0015] Furthermore, a guide block is connected to the outside of the cylinder, and the return spring is sleeved on the guide block along the radial direction of the cylinder. Along the radial direction of the cylinder, the distance between the spring seat and the guide block is D, and the wire diameter d of the return spring is adapted to D.

[0016] Furthermore, a limiting member is threadedly connected to the piston rod, and the limiting member is located on a side of the gland away from the spring seat.

[0017] Furthermore, a first embedding groove is provided on the spring seat, a second embedding groove is provided on the pressure cover, and two ends of the return spring are respectively located in the first embedding groove and the second embedding groove.

[0018] Furthermore, it also includes a driving device, the driving device is used to drive the piston rod to move, and a centrifugal braking mechanism is arranged in the driving device;

[0019] A proximity switch assembly, one end of which is connected to a spring seat, and the other end of which is connected to a gland; the proximity switch assembly is electrically connected to a driving device.

[0020] By adopting the above technical solution, a proximity switch assembly is set to limit the retraction path of the piston rod. When the piston rod stalls, the centrifugal braking mechanism can brake the rapid extension of the piston rod through friction braking, preventing the rebound force of the return spring and the extension speed of the piston rod from being too large, reducing the large impact between the pressure cover and the limit member, and improving the service life of the electric cylinder.

[0021] Furthermore, the proximity switch assembly includes a sensing block, a mounting rod, and a proximity switch body, one end of the mounting rod is fixedly connected to the spring seat, and the other end is slidably connected to the pressure cover, the proximity switch body is connected to the mounting rod, and the sensing block is connected to the pressure cover, and the sensing block and the proximity switch body are inductively coordinated to monitor the relative distance between the pressure cover and the spring seat.

[0022] Furthermore, the driving device also includes a driving assembly, which includes a screw, a motor and a reducer. The screw is coaxially rotatably connected in the cylinder, and a screw nut is connected to the screw. The screw nut is connected to the piston rod and slides axially with the cylinder along the cylinder. The motor is used to drive the screw to rotate, and the reducer is arranged between the motor and the screw.

[0023] Furthermore, the centrifugal braking mechanism includes a counterweight, a speed limit box is arranged between the motor and the reducer, a transition shaft for connecting the motor shaft of the motor and the reducer is arranged in the speed limit box, the counterweight is slidingly connected to the transition shaft along the radial direction of the motor shaft, the side wall of the counterweight away from the transition shaft has friction and is used to abut against the inner wall of the speed limit box, and a centrifugal spring is arranged on the counterweight.

[0024] Furthermore, an electromagnetic brake is arranged inside the motor, and the motor and the electromagnetic brake inside the motor are each provided with a separate power supply, and the electromagnetic brake is closed when powered on and opened when powered off.

[0025] Furthermore, a guide sleeve is connected to the mouth end of the cylinder, and a buffer pad is connected to one end of the guide sleeve facing the inside of the cylinder, and the buffer pad is used to abut against the screw nut.

[0026] Furthermore, a bearing seat is connected to the bottom of the cylinder, the screw rod passes through the bearing seat, the screw rod and the bearing seat are connected via a bearing, and an oil seal is also provided between the screw rod and the bearing shaft.

[0027] The beneficial effect of the utility model is that the reset assembly is arranged between the bottom of the cylinder barrel of the electric cylinder and the head of the piston rod, and the method of directly resetting the piston rod is adopted to realize the rapid resetting of the electric cylinder as a whole, thereby improving the resetting efficiency of the electric cylinder. By arranging a centrifugal braking mechanism, the piston rod is effectively prevented from stalling and retracting, thereby avoiding safety accidents and improving the service life of the electric cylinder.

[0028] In the present application, during the retraction process of the piston rod, the retraction process of the piston rod is controlled by the electrical connection between the proximity switch assembly and the drive device. When the electromagnetic brake is powered off or the entire system is suddenly powered off, the piston rod stalls and extends rapidly. On the one hand, the rebound of the return spring causes the piston rod to quickly return to the pre-tightened position. On the other hand, the centrifugal braking mechanism can brake the rotation of the screw rod through friction braking, preventing the rebound force of the return spring and the extension speed of the piston rod from being too large, thereby reducing the greater impact between the pressure cover and the limit member, and improving the service life of the electric cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0030] Figure 1 It is a structural schematic diagram of the utility model.

[0031] Figure 2 It is a structural schematic diagram of the centrifugal brake mechanism in the utility model.

[0032] In the figure: 1. reset assembly; 10. spring seat; 11. reset spring; 12. pressure cover; 13. limiter; 14. guide block; 2. actuating mechanism; 20. cylinder; 21. screw; 22. screw nut; 23. piston rod; 24. guide sleeve; 25. buffer pad; 26. rod head; 27. bearing seat; 28. bearing; 3. driving device; 30. motor; 31. reducer; 32. speed limit box; 33. centrifugal brake mechanism; 331. counterweight; 332. centrifugal spring; 333. center seat; 334. annular groove; 34. transition shaft; 35. adapter sleeve; 36. coupling; 4. proximity switch assembly; 40. mounting rod; 41. support seat; 42. proximity switch body; 43. induction block; 5. adapter flange. DETAILED DESCRIPTION

[0033] Now the utility model is further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the components related to the utility model.

[0034] In the description of the present utility model, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Reference Figure 1 , 2An electric cylinder capable of automatic reset includes a reset assembly 1, an actuating mechanism 2 and a driving device 3. The actuating mechanism 2 includes a cylinder barrel 20 and a piston rod 23 inserted in the cylinder barrel 20. The driving device 3 includes a driving assembly and a centrifugal brake mechanism 33. The driving assembly is used to control the movement of the piston rod 23. The reset assembly 1 is used to provide a buffer for the retraction of the piston rod 23 and to provide a limit for the reset extension of the piston rod 23. The centrifugal brake mechanism 33 is used to perform emergency braking on the rapid extension of the piston rod 23. The reset assembly 1 also includes a proximity switch assembly 4, which is used to sense the degree of retraction of the piston rod 23. The proximity switch assembly 4 is electrically connected to the driving device 3.

[0037] Specifically, the actuating mechanism 2 also includes a guide sleeve 24, a screw rod 21 and a screw rod nut 22. The bottom of the cylinder barrel 20 is connected to the bearing 28 shaft through a locking nut. The screw rod 21 is coaxially arranged in the cylinder barrel 20. One end of the screw rod 21 passes through the bearing seat 27 and is rotatably connected to the bearing seat 27 through the bearing 28. A bearing inner sleeve is arranged between the bearing 28 and the screw rod 21. The bearing inner sleeve is coaxially fixedly connected to the screw rod 21. An oil seal is arranged between the bearing inner sleeve and the bearing seat 27. A bearing pressure cover is arranged at one end of the bearing 28 close to the cylinder barrel 20.

[0038] The screw nut 22 is located in the cylinder 20 and slides axially along the cylinder 20. The screw nut 22 is threadedly connected to the screw 21. The screw nut 22 is fixedly connected to the piston rod 23. The screw 21 is rotatably connected to the piston rod 23. The guide sleeve 24 is fixedly connected to the mouth of the cylinder 20. The piston rod 23 passes through the guide sleeve 24. A buffer pad 25 is provided at one end of the guide sleeve 24 facing the bottom of the cylinder. The buffer pad 25 is used to abut against the screw nut 22.

[0039] The reset assembly 1 includes a spring seat 10, a reset spring 11 and a pressure cover 12. The spring seat 10 includes a first base plate and a first annular portion connected to the first base plate. The first base plate is fixedly connected to the bearing seat 27. The first annular portion is coaxially sleeved on the cylinder 20 and spaced apart from the cylinder 20. A first embedding groove is formed between the first annular portion, the first base plate and the cylinder 20. A rod head 26 is coaxially connected to the piston rod 23, and a pressure cover 12 is coaxially fixedly connected to the rod head 26. A limit member 13 is threadedly connected to the rod head 26. The limit member 13 can be a hexagonal nut. The limit member 13 is located on the side of the pressure cover 12 away from the cylinder barrel 20. The pressure cover 12 includes a second bottom plate and a second annular portion connected to the second bottom plate. The second bottom plate is sleeved on the piston rod and can slide along the circumference of the piston rod 23. The second annular portion is coaxially sleeved on the piston rod. A second embedding groove is formed between the second annular portion, the second bottom plate and the piston rod 23. The first embedding groove is arranged opposite to the second embedding groove. One end of the return spring 11 is arranged in the first embedding groove and connected to the spring seat 10, and the other end is located in the second embedding groove and connected to the pressure cover 12. The cylinder 20 is externally connected to a guide block 14, and a plurality of guide blocks 14 are arranged along the circumference of the cylinder. The return spring 11 is sleeved on the plurality of guide blocks 14 along the radial direction of the cylinder 20. The return spring 11 abuts against the outer wall of the guide block 14 and the inner wall of the first annular portion, that is, along the radial direction of the cylinder 20, the spacing between the first annular portion and the guide block 14 is D, and the wire diameter d of the return spring is adapted to D.

[0040] The proximity switch assembly 4 includes a sensing block 43, a mounting rod 40, and a proximity switch body 42. A support seat 41 is connected to the outer side wall of the annular portion of the pressure cover 12. One end of the mounting rod 40 is fixedly connected to the spring seat 10, and the other end is slidably connected to the support seat 41 along the axis of the piston rod 23. Multiple proximity switch bodies 42 are arranged along the axial direction of the piston rod 23. Multiple proximity switch bodies 42 are all connected to the mounting rod 40. The sensing block 43 is connected to the pressure cover 12. The sensing block 43 and the proximity switch body 42 are inductively matched to monitor the relative distance between the pressure cover 12 and the spring seat 10.

[0041] The driving assembly includes a motor 30 and a reducer 31. The bottom of the spring seat 10 is connected to the reducer 31 through an adapter flange 5. The output shaft of the reducer 31 extends into the adapter flange 5 and is connected to the screw rod 21 through a coupling 36. The motor 30 is arranged on the side of the reducer 31 away from the screw rod 21. The centrifugal brake mechanism 33 is arranged between the motor 30 and the reducer 31. An electromagnetic brake is arranged in the motor 30. In particular, the motor 30 and the electromagnetic brake inside the motor 30 are each provided with a separate power supply. More particularly, the electromagnetic brake is closed when the power is on and opened when the power is off.

[0042] A speed limit box 32 is connected between the motor 30 and the reducer 31. The speed limit box 32 is rigidly connected to the motor as a whole. A transition shaft 34 is arranged in the speed limit box 32. One end of the transition shaft 34 is coaxially connected to the motor shaft of the motor 30 through an adapter sleeve 35, and the other end passes through the speed limit box 32 and is connected to the reducer 31. The centrifugal brake mechanism 33 includes a center seat 333 and a counterweight 331. The center seat 333 is coaxially connected to the transition shaft 34. The counterweight 331 is slidably connected to the center shaft along the radial direction of the transition shaft 34. The side wall of the counterweight 331 away from the transition shaft 34 has friction and is used to abut against the inner wall of the speed limit box 32. There are multiple counterweights 331 arranged along the circumference of the transition shaft 34, and multiple counterweights 331 form a group. There are multiple groups of counterweights 331 arranged along the axial direction of the transition shaft 34. A centrifugal spring 332 is arranged on each group of counterweights 331. The centrifugal spring 332 is arranged in a ring shape. An annular groove 334 is arranged on the counterweight 331, and the centrifugal spring 332 is embedded in the annular groove 334.

[0043] The implementation principle of the present application is: the pressure cover 12 is pressed against the limiter 13 under the elastic force of the return spring 11, and the limiter 13 is rotated so that the return spring 11 maintains a certain pressure pre-tightening on the pressure cover 12 to achieve the force required when the device is closed.

[0044] The motor 30 is powered on and operates, and the electromagnetic brake inside the motor 30 remains in a power-off state. The electromagnetic brake is opened, and the motor 30 drives the transition shaft 34 and the reducer 31 to rotate, and the counterweight 331 rotates with the transition shaft 34. At this time, the pulling force of the centrifugal spring 332 can counteract the centrifugal force of the counterweight 331. The counterweight 331 is spaced apart from the inner wall of the speed limit box 32. The reducer 31 drives the coupling 36 and the screw 21 to rotate. Correspondingly, the screw nut 22 drives the piston rod 23 to retract, and the pressure cover 12 moves toward the spring seat 10 and compresses the reset spring 11. When a certain stroke is traveled, the proximity switch body 42 will sense the sensing block 43, and an electrical signal is generated at this time. The electromagnetic brake of the motor 30 is powered on and braked to lock the motor shaft.

[0045] When the electromagnetic brake is powered off or the entire system is suddenly powered off, the screw 21 loses speed and reverses, the piston rod 23 extends quickly, and the return spring 11 pushes the spring cover 12 back in the opposite direction until it returns to the position where the return spring 11 begins to pre-tighten. At this time, the counterweight 331 is at a high speed of the motor 30, and the centrifugal force overcomes the pulling force of the centrifugal spring 332, and the friction with the inner wall of the speed limit box 32 generates resistance to achieve the speed limiting effect, thereby preventing the return spring 11 from rebounding with excessive force and speed, reducing the greater impact between the cover 12 and the limit member 13, and improving the service life of the cover 12 and the limit member 13.

[0046] During the expansion and contraction and compression of the reset spring 11, the guide block 14, the spring seat 10 and the pressure cover 12 play the role of axial guide support to prevent equipment problems caused by eccentric expansion and contraction of the spring.

[0047] In summary, the present application sets the reset assembly 1 between the bottom of the electric cylinder barrel 20 and the rod head 26 of the piston rod 23 to achieve rapid reset of the electric cylinder as a whole, improve the reset efficiency of the electric cylinder, and set a centrifugal braking mechanism 33 to effectively prevent the piston rod 23 from stalling and retracting, thereby avoiding safety accidents and increasing the service life of the electric cylinder.

[0048] In the present application, during the retraction of the piston rod 23, the retraction process of the piston rod 23 is controlled by the electrical connection between the proximity switch assembly 4 and the drive device 3. When the electromagnetic brake is powered off or the entire system is suddenly powered off, the piston rod 23 stalls and extends rapidly. On the one hand, the return spring 11 rebounds to make the piston rod 23 quickly return to the pre-tightened position. On the other hand, the centrifugal brake mechanism 33 can brake the rotation of the screw 21 through friction braking, preventing the rebound force of the return spring 11 and the extension speed of the piston rod 23 from being too large, thereby reducing the greater impact between the pressure cover 12 and the limit member 13, and improving the service life of the electric cylinder.

[0049] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without departing from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An electric cylinder capable of automatically resetting, characterized in that: include a cylinder (20), and A piston rod (23), wherein the piston rod (23) is inserted into the cylinder barrel (20) and is slidably connected to the cylinder barrel (20) along the axial direction of the cylinder barrel (20); A spring seat (10), wherein the spring seat (10) is arranged outside the cylinder (20); A gland (12), the gland (12) being arranged on one end of the piston rod (23) located outside the cylinder barrel (20); A return spring (11), wherein the return spring (11) is sleeved outside the cylinder (20), and the return spring (11) is arranged between the spring seat (10) and the pressure cover (12).

2. The electric cylinder capable of automatic reset according to claim 1, characterized in that: The cylinder (20) is externally connected to a guide block (14); the return spring (11) is sleeved on the guide block (14) along the radial direction of the cylinder (20); the spacing between the spring seat (10) and the guide block (14) is D; and the wire diameter d of the return spring (11) is adapted to D.

3. The electric cylinder capable of automatic reset according to claim 1, characterized in that: The piston rod (23) is connected to a limiting member (13), and the limiting member (13) is located on a side of the gland (12) away from the spring seat (10).

4. The electric cylinder capable of automatic reset according to claim 1, characterized in that: The spring seat (10) is provided with a first embedding groove, the pressure cover (12) is provided with a second embedding groove, and the two ends of the return spring (11) are respectively located in the first embedding groove and the second embedding groove.

5. The electric cylinder capable of automatic reset according to claim 1, characterized in that: Also includes, A driving device (3), the driving device (3) being used to drive the piston rod (23) to move, and a centrifugal braking mechanism (33) being arranged in the driving device (3); A proximity switch assembly (4), one end of the proximity switch assembly (4) is connected to a spring seat (10), and the other end is connected to a pressure cover (12), and the proximity switch assembly (4) is electrically connected to a driving device (3).

6. The electric cylinder capable of automatic reset according to claim 5, characterized in that: The proximity switch assembly (4) comprises a sensing block (43), a mounting rod (40), and a proximity switch body (42); one end of the mounting rod (40) is fixedly connected to the spring seat (10), and the other end is slidably connected to the pressure cover (12); the proximity switch body (42) is connected to the mounting rod (40), and the sensing block (43) is connected to the pressure cover (12); the sensing block (43) and the proximity switch body (42) are inductively matched to monitor the relative distance between the pressure cover (12) and the spring seat (10).

7. The automatically reset electric cylinder according to claim 5, characterized in that: The driving device (3) further comprises a driving assembly, the driving assembly comprising a screw (21), a motor (30) and a reducer (31); the screw (21) is coaxially rotatably connected in the cylinder (20); a screw nut (22) is connected to the screw (21); the screw nut (22) is connected to the piston rod (23) and slides axially along the cylinder (20); the motor (30) is used to drive the screw (21) to rotate; and the reducer (31) is arranged between the motor (30) and the screw (21).

8. The electric cylinder capable of automatic reset according to claim 7, characterized in that: The centrifugal brake mechanism (33) comprises a counterweight (331); a speed limit box (32) is arranged between the motor (30) and the reducer (31); a transition shaft (34) for connecting the motor shaft of the motor (30) and the reducer (31) is arranged in the speed limit box (32); the counterweight (331) is slidably connected to the transition shaft (34) along the radial direction of the motor shaft; the side wall of the counterweight (331) away from the transition shaft (34) has friction and is used to abut against the inner side wall of the speed limit box (32); and a centrifugal spring (332) is arranged on the counterweight (331).

9. The electric cylinder capable of automatic reset according to claim 7, characterized in that: An electromagnetic brake is arranged inside the motor (30), and the motor (30) and the electromagnetic brake are each provided with a separate power supply. The electromagnetic brake is closed in a power-on state and is opened in a power-off state.

10. The electric cylinder capable of automatic reset according to claim 7, characterized in that: The barrel end of the cylinder (20) is connected to a guide sleeve (24), and one end of the guide sleeve (24) facing the inside of the cylinder (20) is connected to a buffer pad (25), and the buffer pad (25) is used to abut against the screw nut (22).

11. The electric cylinder capable of automatic reset according to claim 7, characterized in that: The bottom of the cylinder (20) is connected to a bearing seat (27), the screw rod (21) passes through the bearing seat (27), the screw rod (21) and the bearing seat (27) are connected via a bearing (28), and an oil seal is also provided between the screw rod (21) and the bearing seat (27).

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