Electric push rod

Abstract

The embodiment of the utility model discloses an electric push rod, which comprises a motor, a screw rod, a movable pipe and an outer pipe, the output end of the motor is connected with the lead screw, the movable pipe is arranged on the outer side of the lead screw in a sleeving mode and is in threaded connection with the lead screw, and the motor can drive the lead screw to rotate and drive the movable pipe to move in the axial direction; the outer pipe is arranged on the outer side of the movable pipe in a sleeving mode, one end of the outer pipe is fixedly connected with a shell of the motor, the other end of the outer pipe is covered with a pipe cap, and one end of the movable pipe penetrates out of the pipe cap; a limiting ring is arranged on the outer side of the movable pipe, a sliding block is slidably connected to the inner side wall of the outer pipe, a travel switch electrically connected with the motor is fixedly connected to the sliding block, the limiting ring can touch the travel switch to enable the motor to stop working, one end of the sliding block is in threaded connection with a bolt, and the bolt penetrates out of the pipe cap. When the bolt is rotated, the sliding block slides axially and drives the travel switch to move.

Description

Technical Field

[0001] The utility model relates to the technical field of electric devices, in particular to an electric push rod. Background Art

[0002] An electric push rod is an electric device that drives a lead screw by a motor to drive a movable tube to extend and retract relative to an outer tube. Usually, the limit position of the movable tube's movement is adjusted by setting a micro switch, that is, two fixed micro switches are set. When the movable tube touches any one of them, the motor is powered off, thereby achieving the extension and retraction of the movable tube. However, since the position of the micro switch cannot be adjusted at will, the limit distance of the movable tube's movement is difficult to adjust, and it cannot be applied to more usage scenarios, and its applicability is poor. Utility Model Content

[0003] In view of this, the utility model provides an electric push rod, which is used to solve the problem that it is difficult for the electric push rod in the prior art to adjust the limit distance of movement of the movable tube.

[0004] To achieve one or part or all of the above purposes or other purposes, the present application provides an electric push rod, including a motor, a screw rod, a movable tube and an outer tube;

[0005] The output end of the motor is connected to the screw rod, the movable tube is sleeved outside the screw rod and is threadedly connected to the screw rod, and the motor can drive the screw rod to rotate and drive the movable tube to move axially;

[0006] The outer tube is sleeved on the outer side of the movable tube, one end of the outer tube is fixedly connected to the housing of the motor, and the other end is covered with a tube cap, and one end of the movable tube passes through the tube cap;

[0007] A limit ring is provided on the outside of the movable tube, a slider is slidably connected to the inner wall of the outer tube, a travel switch electrically connected to the motor is fixedly connected to the slider, the limit ring can touch the travel switch to stop the motor, a bolt is threadedly connected to one end of the slider, the bolt passes through the pipe cap, and when the bolt is rotated, the slider slides axially and drives the travel switch to move.

[0008] Furthermore, one end of the sliding block close to the pipe cap is fixedly connected to a connecting piece with a hollow structure, one end of the connecting piece is provided with a screw hole, and the bolt passes through the pipe cap and then passes through the screw hole into the interior of the connecting piece.

[0009] Furthermore, a left limiter and a right limiter are provided on the inner side wall of the outer tube, the left limiter and the right limiter form a slide groove, the slider can slide in the slide groove, and the connecting member can move between the left limiter and the right limiter.

[0010] Furthermore, the connecting piece includes an upper connecting piece and a lower connecting piece, a cavity is formed between the upper connecting piece and the lower connecting piece, one end of the upper connecting piece and the lower connecting piece is fixedly connected with a connecting ring, the connecting ring abuts against the inner wall of the pipe cap, and the bolt passes through the connecting ring.

[0011] Furthermore, a guide protrusion is provided on the inner side wall of the outer tube, and a guide groove adapted to the guide protrusion is provided on the outer side of the limiting ring.

[0012] Furthermore, the travel switch is arranged on a side close to the movable tube, and a limit block is formed on the limit ring, and the limit block can press the contact of the travel switch.

[0013] Furthermore, the limiting ring is arranged at an end close to the motor.

[0014] Furthermore, the output shaft of the motor is a worm, and a gear adapted to the worm is also provided in the motor. The gear is transmission-connected to the worm, and the axis of the worm is perpendicular to the axis of the gear.

[0015] Furthermore, one end of the screw rod is inserted into the gear, and a ball bearing is provided between the gear and the housing of the motor.

[0016] Furthermore, a clamping piece is provided at one end of the movable tube close to the tube cap.

[0017] Implementing the embodiments of the present utility model will have the following beneficial effects:

[0018] The electric push rod provided by the utility model is connected to the slider through the threaded connection of the bolt, and the bolt is turned. The slider will undergo axial linear displacement on the bolt under the action of friction, driving the travel switch connected to the slider to move in the outer tube, so as to adjust the distance between the travel switch and the upper limit ring of the movable tube. When it needs to be reset, the bolt is rotated in the opposite direction to the limit position, and the slider is reset. At this time, the distance between the travel switch and the limit ring returns to the maximum value. The user can adjust the limit distance that the movable tube can move according to the use requirements, with few restrictions, simple operation and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] in:

[0021] Figure 1 This is a schematic structural diagram of an embodiment of the electric linear actuator proposed in this application;

[0022] Figure 2 This is a schematic diagram of the exploded structure of an embodiment of the electric push rod proposed in this application;

[0023] Figure 3 This is a schematic structural diagram of an outer tube in one embodiment of the electric push rod proposed in this application;

[0024] Figure 4 This is a partial structural diagram of a slider, a connecting piece and other structures in one embodiment of the electric push rod proposed in this application;

[0025] Figure 5 This is a partial structural schematic diagram of the motor and movable tube in one embodiment of the electric push rod proposed in this application.

[0026] Reference numerals:

[0027] 1. Motor; 11. Worm; 12. Gear; 13. Ball bearing;

[0028] 2. Screw rod;

[0029] 3. movable tube; 31. limiting ring; 32. guide groove; 33. limiting block; 34. clamping piece;

[0030] 4. Outer tube; 41. Tube cap; 42. Slider; 43. Travel switch; 431. Contact; 44. Bolt; 45. Connector; 451. Upper connector; 452. Lower connector; 453. Connecting ring; 46. Left limiter; 47. Right limiter; 48. Guide protrusion. DETAILED DESCRIPTION

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0034] Reference Figures 1 to 5 , the present application proposes an electric push rod, comprising a motor 1, a screw rod 2, a movable tube 3 and an outer tube 4;

[0035] The output end of the motor 1 is connected to the screw rod 2, and the movable tube 3 is sleeved on the outside of the screw rod 2 and threadedly connected with the screw rod 2. The motor 1 can drive the screw rod 2 to rotate and drive the movable tube 3 to move axially; the screw rod 2 and the movable tube 3 are coaxially arranged, and a thread (not shown in the figure) is provided on the outer wall of the screw rod 2, and a thread matching it is provided on the inner wall of the movable tube 3. The thread on the movable tube 3 can be provided only at the end away from the motor 1, or on the entire inner wall of the movable tube 3. When the screw rod 2 rotates, it is affected by the friction force, and the movable tube 3 performs axial linear motion relative to the screw rod 2. When the motor 1 rotates forward, the movable tube 3 moves forward, and when the motor 1 reverses, the movable tube 3 moves backward and resets.

[0036] Specifically, the output shaft of the motor 1 is a worm 11, and a gear 12 adapted to the worm 11 is also provided in the motor 1. The gear 12 is connected to the worm 11 in a transmission manner, and the axis of the worm 11 is perpendicular to the axis of the gear 12. The gear 12 is meshed with the worm 11. When the motor 1 is working, the worm 11 rotates, driving the gear 12 to rotate. Since the motor 1 rotates at a high speed and the gear 12 has a large number of teeth, the motor 1 has to rotate for many turns before the gear 12 rotates for one turn, which has the effect of decelerating the motor 1. While protecting the motor 1 from overload, it can also improve the moving accuracy of the movable tube 3. One end of the screw 2 is inserted into the gear 12, and a ball bearing 13 is provided between the gear 12 and the housing of the motor 1, so that the position of the gear 12 and the screw 2 is more stable. In addition, the gear 12 is arranged on one side of the motor 1, so that the motor 1 and the screw 2 are arranged vertically, which reduces the overall length of the electric push rod and improves the space utilization rate.

[0037] In this embodiment, the outer tube 4 is sleeved on the outside of the movable tube 3, one end of the outer tube 4 is fixedly connected to the outer shell of the motor 1, and the other end is covered with a tube cap 41, and one end of the movable tube 3 passes through the tube cap 41; the tube cap 41 only plays a partial supporting role for the movable tube 3. When the motor 1 is working, the friction between the movable tube 3 and the tube cap 41 is small, and the movable tube 3 can move relative to the tube cap 41 without being affected.

[0038] In addition, a limit ring 31 is provided on the outside of the movable tube 3, a slider 42 is slidably connected to the inner wall of the outer tube 4, and a travel switch 43 electrically connected to the motor 1 is fixedly connected to the slider 42. The limit ring 31 can touch the travel switch 43 to stop the motor 1 from working. A bolt 44 is threadedly connected to one end of the slider 42, and the bolt 44 passes through the pipe cap 41. When the bolt 44 is rotated, the slider 42 slides axially and drives the travel switch 43 to move.

[0039] Specifically, one end of the slider 42 near the pipe cap 41 is fixedly connected with a connector 45 of a hollow structure, and one end of the connector 45 is provided with a screw hole. The bolt 44 passes through the pipe cap 41 and then passes through the screw hole to the inside of the connector 45. A left limiter 46 and a right limiter 47 are provided on the inner side wall of the outer tube 4. The left limiter 46 and the right limiter 47 form a slide groove. The slider 42 can slide in the slide groove, and the connector 45 can move between the left limiter 46 and the right limiter 47. The slide groove guides and supports the slider 42 and the connector 45, so that the slider 42 and the connector 45 move along the axial direction, ensuring the accuracy of the electric push rod when adjusting the stroke. In addition, the left limiter 46 and the right limiter 47 abut against both sides of the connector 45 to prevent the connector 45 from radially deviating when the bolt 44 rotates. Both sides of the slider 42 are flanged structures, which are respectively in contact with the left stopper 46 and the right stopper 47 to enhance the connection strength between the slider 42 and the stopper groove and improve the sliding stability of the slider 42. In addition, since the widths of the slider 42 and the connecting member 45 are similar to the diameter of the bolt 44, the longitudinal section of the outer tube 4 is small at the top and large at the bottom, which can save space as much as possible and improve precision.

[0040] The limit ring 31 is arranged on the movable tube 3 at one end close to the motor 1. Before the motor 1 is started, the screw rod 2 is in the movable tube 3, and the movable tube 3 is retracted in the outer tube 4. At this time, the distance between the travel switch 43 and the limit ring 31 is the farthest, which is the maximum travel that the electric push rod can achieve. The user can determine the maximum travel of the movable tube 3 within this range according to the needs.

[0041] One end of the bolt 44 is provided with a slot, which may be a hexagonal slot or a square slot. The user can turn the bolt 44 through the slot, and at the same time, the user applies a force pointing inward to the bolt 44. The bolt 44 is connected to the connector 45 through a thread. Under the action of the friction between the bolt 44 and the connector 45, the bolt 44 moves linearly relative to the outer tube 4, driving the slider 42 to move in the slide slot, so that the travel switch 43 connected to the slider 42 is displaced, the distance between the travel switch 43 and the limit ring 31 changes, and the maximum displacement that the movable tube 3 can occur changes. When the user turns the bolt 44 in one direction, the distance between the travel switch 43 and the limit ring 31 is shortened, and when the user turns the bolt 44 in the other direction, the distance between the travel switch 43 and the limit ring 31 becomes longer.

[0042] In one embodiment, the connecting member 45 includes an upper connecting member 451 and a lower connecting member 452, a cavity is formed between the upper connecting member 451 and the lower connecting member 452, a connecting ring 453 is fixedly connected to one end of the upper connecting member 451 and the lower connecting member 452, the connecting ring 453 abuts against the inner side wall of the pipe cap 41, and the bolt 44 passes through the connecting ring 453. The connecting member 45 can also be integrally formed, formed by bending a strip plate, the connecting ring 453 is arranged at one end of the connecting member 45, and the other end of the connecting member 45, that is, the two ends of the strip plate, clamps one end of the slider 42 and is fixed by a fastener.

[0043] In addition, a guide protrusion 48 is provided on the inner side wall of the outer tube 4, and a guide groove 32 adapted to the guide protrusion 48 is provided on the outer side of the limiting ring 31. Since the movable tube 3 is relatively long, the cooperation between the guide protrusion 48 and the guide groove 32 can make the movable tube 3 always move along the axial direction without deviation, thereby improving the movement accuracy of the movable tube 3.

[0044] In this embodiment, the travel switch 43 is arranged on a side close to the movable tube 3, and a limit block 33 is formed on the limit ring 31, and the limit block 33 can press the contact 431 of the travel switch 43. The diameter of the limit ring 31 is larger than the diameter of the movable tube 3, and the contact 431 on the travel switch 43 is arranged on a side close to the limit ring 31. When the limit ring 31 moves to the position of the contact 431, the travel switch 43 can quickly cut off the power to the motor 1.

[0045] In this embodiment, a clamping member 34 is provided at one end of the movable tube 3 near the tube cap 41. A clamping structure is also provided on the housing of the motor 1, and the user can fix the electric push rod on other structures, and can also be hinged with an external structure through the clamping member 34.

[0046] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. An electric push rod, characterized in that: It includes a motor, a lead screw, a movable tube and an outer tube; The output end of the motor is connected to the screw rod, the movable tube is sleeved outside the screw rod and is threadedly connected to the screw rod, and the motor can drive the screw rod to rotate and drive the movable tube to move axially; The outer tube is sleeved on the outer side of the movable tube, one end of the outer tube is fixedly connected to the housing of the motor, and the other end is covered with a tube cap, and one end of the movable tube passes through the tube cap; A limit ring is provided on the outside of the movable tube, a slider is slidably connected to the inner wall of the outer tube, a travel switch electrically connected to the motor is fixedly connected to the slider, the limit ring can touch the travel switch to stop the motor, a bolt is threadedly connected to one end of the slider, the bolt passes through the pipe cap, and when the bolt is rotated, the slider slides axially and drives the travel switch to move.

2. The electric linear actuator according to claim 1, characterized in that: One end of the sliding block close to the pipe cap is fixedly connected with a connecting piece with a hollow structure. One end of the connecting piece is provided with a screw hole. The bolt passes through the pipe cap and then passes through the screw hole to the inside of the connecting piece.

3. The electric linear actuator according to claim 2, characterized in that: A left limiter and a right limiter are provided on the inner side wall of the outer tube. The left limiter and the right limiter form a slide groove. The slider can slide in the slide groove. The connecting member can move between the left limiter and the right limiter.

4. The electric linear actuator according to claim 2, characterized in that: The connecting piece includes an upper connecting piece and a lower connecting piece, a cavity is formed between the upper connecting piece and the lower connecting piece, one end of the upper connecting piece and the lower connecting piece is fixedly connected with a connecting ring, the connecting ring abuts against the inner side wall of the pipe cap, and the bolt passes through the connecting ring.

5. The electric linear actuator according to claim 1, characterized in that: A guide protrusion is arranged on the inner side wall of the outer tube, and a guide groove matched with the guide protrusion is arranged on the outer side of the limiting ring.

6. The electric linear actuator according to claim 1, characterized in that: The travel switch is arranged on a side close to the movable tube, and a limit block is formed on the limit ring, and the limit block can press the contact of the travel switch.

7. The electric linear actuator according to claim 1, characterized in that: The limiting ring is arranged at one end close to the motor.

8. The electric linear actuator according to claim 1, characterized in that: The output shaft of the motor is a worm, and a gear adapted to the worm is also provided in the motor. The gear is transmission-connected to the worm, and the axis of the worm is perpendicular to the axis of the gear.

9. The electric linear actuator according to claim 8, characterized in that: One end of the screw rod is inserted into the gear, and a ball bearing is arranged between the gear and the housing of the motor.

10. The electric linear actuator according to claim 1, characterized in that: A clamping piece is arranged at one end of the movable tube close to the tube cap.

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