An electric push rod with a hand-screw release device

Abstract

The present invention discloses an electric push rod with a hand-turned release device, which belongs to the field of linear transmission technology, and includes a housing, a driving motor, a transmission assembly, a rotating screw and a transmission nut, and also includes: a clutch device for connecting or cutting off the power transmission between the transmission assembly and the rotating screw; a self-locking device for generating friction resistance to the rotating screw when the rotating screw is reversed; a hand-turned release device, including a release knob, a first driving member connected to the clutch device, a second driving member for connecting the self-locking device, and the release knob presenting an initial state and a fully released state through rotational motion, and from the initial state to the fully released state, the first driving member drives the clutch device to disconnect the power connection, and the second driving member drives the release torsion spring to loosen. The advantage of the present invention is that the hand-turned release device can control two devices, and the operation is smoother and more convenient.

Description

[Technical field]

[0001] The invention relates to an electric push rod with a hand-twist release device, belonging to the technical field of linear transmission. [Background technology]

[0002] Electric push rods, also known as linear actuators, are widely used in furniture, medical equipment, solar power generation and other fields. Their main structure includes a drive motor, a transmission worm, a worm wheel, a lead screw and a nut. The working principle is that the drive motor drives the transmission worm to rotate, the transmission worm engages with the worm wheel to drive the worm wheel to rotate, the rotation of the worm wheel drives the lead screw to rotate, and the rotation of the lead screw drives the nut to move axially. The nut is generally connected to an inner tube to realize the telescopic movement of the inner tube.

[0003] In combination with the application environment of the electric push rod, when the electric push rod encounters a drive motor failure, or a power outage or other situation where the power needs to be cut off, a clutch device will be added. The clutch device is mainly used to cut off the power between the drive motor and the rotating screw, so that reverse push can be achieved by manually driving the rotating screw to rotate. For example, CN201621013870.3 discloses a solution of adding a clutch device to the electric push rod.

[0004] In addition, in order to make the electric push rod generate resistance when it retracts, a self-locking device is usually provided on the electric push rod. Such self-locking device usually includes a friction sleeve and a self-locking torsion spring sleeved outside the friction sleeve. When the friction sleeve reverses with the rotating lead screw, the self-locking torsion spring will radially retract and hold the friction sleeve tightly, thereby generating self-locking resistance to the rotating lead screw. Such self-locking devices have been widely disclosed on electric push rods.

[0005] However, currently available electric push rods are usually only provided with a clutch device, or only with a self-locking device. Even if both a clutch device and a self-locking device are provided, the driving components that drive the two devices are usually separated from each other. That is, when the operator needs to control the clutch device and the self-locking device at the same time, the two devices need to be operated independently, which makes the operation more complicated.

[0006] In addition, the current clutch device or self-locking device basically relies on the method of pulling the pull rod by pulling the wire. In this operation mode, the pulling force or stroke is difficult to control, which causes the clutch device or self-locking device to operate not very smoothly. Of course, there are also release devices similar to hand-twist on the market, such as the Chinese utility model patent CN201220326831.4, which uses hand-twist to release, but this type of hand-twist device is generally installed at the end of the electric push rod. If the installation stroke of the electric push rod is relatively limited, the installation space of the electric push rod with a hand-twist device will be affected. [Summary of the invention]

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an electric push rod with a hand-turn release device, so that the hand-turn release device can control two devices, and the operation is smoother and more convenient.

[0008] To solve the above technical problems, the present invention adopts the following technical solutions:

[0009] An electric push rod with a hand-twist release device comprises a housing, a driving motor, a transmission assembly, a rotating screw and a transmission nut. The driving motor drives the rotating screw to rotate through the transmission assembly, and the rotating screw drives the transmission nut to move axially along the rotating screw. The electric push rod also comprises:

[0010] The clutch device is located between the transmission assembly and the rotating screw rod, and is used to connect or disconnect the transmission assembly and the rotating screw rod.

[0011] Power transmission between moving screws;

[0012] The self-locking device generates friction resistance on the rotating screw when the rotating screw is reversed.

[0013] The self-locking device includes a release torsion spring for unlocking the self-locking device;

[0014] A hand-turn release device is arranged on the housing, and includes a first drive member, a second drive member and a release knob for driving the first drive member and the second drive member, the first drive member is connected to the clutch device, the second drive member is used to connect the self-locking device, and the release knob presents an initial state and a fully released state through rotational movement. In the process from the initial state to the fully released state, the first drive member drives the clutch device to disconnect the power connection, and the second drive member drives the release torsion spring to loosen.

[0015] The beneficial effects of the present invention are as follows:

[0016] The electric push rod in the present invention is provided with both a clutch device and a self-locking device, so that the function of the electric push rod is more comprehensive. In addition, the clutch device combined with the self-locking device has another advantage. After the clutch device disconnects the power, the rotating screw is almost in a completely free rotation state, which easily causes the electric push rod to retract too quickly. The self-locking device can provide a certain resistance to prevent the retraction speed from being too fast.

[0017] Secondly, the self-locking device in the present invention also has a release torsion spring, that is, the self-locking device itself can be unlocked. When the release torsion spring is loosened, the self-locking device is in an unlocked state. At this time, no matter the electric push rod rotates forward or reverse, the self-locking device produces almost no resistance. This situation can put the electric push rod in a quick release state, that is, it can retract quickly.

[0018] In addition, the electric push rod in the present invention is provided with a hand-turned release device, which includes a first drive member, a second drive member and a release knob for driving the first drive member and the second drive member, the first drive member and the second drive member are respectively used to drive the clutch device and the self-locking device. When the electric push rod needs to be released quickly, the operator operates the hand-turned release device to put it in a fully released state, which can put the clutch device in a disconnected state and the self-locking device in an unlocked state. The user only needs to operate one hand-turned release device to control the two devices, which is very convenient to operate.

[0019] Finally, the hand-twist release device of the present invention is released by a release knob. This rotation method can better control the driving stroke of the first drive member and the second drive member, and can minimize the problem of the driving stroke of the first drive member and the second drive member being too large in an instant, and its smoothness is better. Moreover, the setting position of the hand-twist release in the present invention is located on the housing, not at the end of the electric push rod like the traditional hand-twist device, so there is no need to increase the axial installation distance of the electric push rod itself, so that the axial installation space is not affected.

[0020] Preferably, the hand-turned release device further comprises a pull rod which can move axially along the rotating screw, the pull rod is provided with a rack portion, and the release knob is connected to a release gear which meshes with the rack portion.

[0021] Preferably, the electric push rod comprises an outer tube and an inner tube telescopic relative to the outer tube, a mounting base is mounted on the outer tube, the release knob is rotatably mounted on the mounting base, and the pull rod is at least partially slidably mounted on the mounting base.

[0022] Preferably, a limiting step is provided on the pull rod, and a pull rod reset spring for resetting the pull rod is provided between the limiting step and the mounting base.

[0023] Preferably, the second driving member includes a push block, which is arranged on the pull rod or integrated with the pull rod, and the push block is provided with a guide surface. The release torsion spring includes a radially extending pin. When the pull rod moves axially, the guide surface on the push block contacts the pin to expand the release torsion spring outward.

[0024] Preferably, the first driving member comprises a rocker arm rotatably arranged relative to the housing, and the pull rod drives the rocker arm to rotate when the pull rod moves axially, and the rocker arm swings to axially push the clutch device.

[0025] Preferably, the transmission assembly comprises a transmission worm and a transmission worm wheel, the transmission worm is connected to the driving motor, the transmission worm wheel is sleeved outside the rotating screw, and the clutch device is arranged between the transmission worm wheel and the rotating screw.

[0026] Preferably, the clutch device comprises a coupling sleeve, the transmission worm wheel is provided with tooth grooves matching the coupling sleeve for transmission, and the coupling sleeve is sleeved on the rotating screw and can move axially relative to the rotating screw.

[0027] Preferably, the self-locking device comprises a first friction sleeve and a second friction sleeve, the first friction sleeve and the second friction sleeve are respectively mounted on the rotating screw, and the axial end faces of the first friction sleeve and the second friction sleeve are abutted against each other, the first friction sleeve rotates synchronously with the rotating screw, and the second friction sleeve rotates freely relative to the rotating screw, the first friction sleeve is mounted with a self-locking torsion spring, and the release torsion spring is mounted on the second friction sleeve; or, the self-locking device comprises a third friction sleeve, the third friction sleeve rotates synchronously with the rotating screw, and the release torsion spring is mounted on the third friction sleeve.

[0028] Preferably, when the hand-twist release device returns from a fully released state to an initial state, the second drive member first disengages from a release torsion spring on the self-locking device to generate a self-locking force, and after the release torsion spring returns, the first drive member correspondingly disengages from the clutch device.

[0029] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

Brief Description of the Drawings

[0030] The present invention will be further described below in conjunction with the accompanying drawings:

[0031] Figure 1 The overall schematic diagram of the electric push rod of the embodiment of the present invention is Figure 1 ;

[0032] Figure 2 Schematic diagram of the decomposition of the electric push rod of the first embodiment of the present invention Figure 1 ;

[0033] Figure 3 Schematic diagram of the decomposition of the electric push rod of the first embodiment of the present invention Figure 2 ;

[0034] Figure 4 It is a partial enlarged schematic diagram of an electric push rod in Embodiment 1 of the present invention;

[0035] Figure 5 Schematic diagram of the explosion of internal parts in an electric push rod according to an embodiment of the present invention. [Specific implementation method]

[0036] The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0037] In the following description, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate orientation or position relationship are based on the orientation or position relationship shown in the drawings and are only for the convenience of describing the embodiments and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] Embodiment 1:

[0039] like Figures 1 to 5 As shown, this embodiment is an electric push rod, which is also generally called a linear drive or a linear actuator. The electric push rod includes a housing, an outer tube 13, an inner tube 14, a driving motor, a transmission assembly, a rotating screw 20 and a transmission nut 21. The driving motor drives the rotating screw 20 to rotate through the transmission assembly. The rotating screw 20 rotates to drive the transmission nut 21 to move axially along the rotating screw 20. The transmission nut 21 is fixedly connected to the inner tube 14. When the transmission nut 21 moves axially, it drives the inner tube 14 to move axially relative to the outer tube 13 and the housing. The outer end of the inner tube 14 is connected to the object to be driven. The electric push rod in this embodiment also includes:

[0040] The clutch device is provided between the transmission assembly and the rotating screw 20, and is used to connect or cut off the power transmission between the transmission assembly and the rotating screw 20;

[0041] A self-locking device, which generates friction resistance to the rotating screw 20 when the rotating screw 20 is reversed, and the self-locking device includes a release torsion spring 43 for unlocking the self-locking device;

[0042] A hand-turn release device is arranged on the outer shell. In this embodiment, the outer shell includes an upper shell 11 and a lower shell 12, including a first drive member, a second drive member and a release knob 55 for driving the first drive member and the second drive member. The first drive member is connected to a clutch device, and the second drive member is used to connect the self-locking device. The release knob presents an initial state and a fully released state through rotational movement. In the process from the initial state to the fully released state, the first drive member drives the clutch device to disconnect the power connection, and the second drive member drives the release torsion spring to loosen.

[0043] The electric push rod in this embodiment is provided with both a clutch device and a self-locking device, so that the function of the electric push rod is more comprehensive. In addition, the clutch device combined with the self-locking device has another advantage. After the clutch device disconnects the power, the rotating screw 20 is almost in a completely free rotation state, which easily causes the electric push rod to retract too quickly. The self-locking device can provide a certain resistance to prevent the rotating screw 20 from rotating too quickly, thereby preventing the drive nut 21 from retracting too quickly.

[0044] Secondly, the self-locking device in this embodiment also has a release torsion spring 43, that is, the self-locking device itself can also be unlocked. When the release torsion spring is loosened, the self-locking device is in an unlocked state. At this time, no matter the electric push rod rotates forward or reverse, the self-locking device produces almost no resistance to the rotating screw 20. This situation can put the electric push rod in a quick release state, that is, it can retract quickly.

[0045] In addition, the electric push rod in the present invention is provided with a hand-turned release device, which includes a first drive member, a second drive member and a release knob 55 for driving the first drive member and the second drive member. The first drive member and the second drive member are respectively used to drive the clutch device and the self-locking device. When the electric push rod needs to be released quickly, the operator operates the hand-turned release device to put it in a fully released state, which can put the clutch device in a disconnected state and the self-locking device in an unlocked state. The user only needs to operate one hand-turned release device to control the two devices, which is very convenient to operate.

[0046] Finally, the hand-turned release device of the present invention is released by releasing the knob 55. This rotation method can better control the driving stroke of the first driving member and the second driving member, and can minimize the problem of the driving stroke of the first driving member and the second driving member being too large in an instant, and its smoothness is better. Moreover, the hand-turned release device of the present invention is set on the housing, not at the end of the electric push rod like the traditional hand-turned device, so there is no need to increase the axial installation distance of the electric push rod itself, so that the axial installation space is not affected.

[0047] In order to ensure better operating accuracy when the release knob 55 is rotated, the hand-turned release device in this embodiment also includes a pull rod 51 that can move axially along the rotating screw, and a rack portion 511 is provided on the pull rod. The rack portion 511 can be an integral structure with the pull rod 51, or can be separately connected. The release knob 55 is connected to a release gear 551 that meshes with the rack portion 511. When the release knob 55 is rotated, the release gear 551 is driven to rotate. When the release gear 551 rotates, it drives the rack portion 511 to move axially along the rotating screw 20, thereby driving the pull rod 51 to move axially. When the pull rod 51 moves axially, it drives the first drive component and the second drive component to move, thereby achieving the purpose of driving the clutch device and the self-locking device.

[0048] In order to make the pull rod 51 more stably installed, a mounting base 6 is installed on the outer tube in this embodiment, the release knob 55 is rotatably mounted on the mounting base 6, and the pull rod 51 is at least partially slidably mounted on the mounting base 6. Figure 1 and 2 As shown in the figure, in this embodiment, the mounting base 6 is mounted on the outer tube 13, the rack portion 511 of the pull rod 51 is located inside the mounting base 6, and a portion of the pull rod 51 extends out of the mounting base 6. At the same time, a base cover plate 61 is provided above the mounting base 6 to cover the release gear 551, the rack portion 511 and other components.

[0049] In this embodiment, the pull rod is provided with a limit step, and a pull rod reset spring 56 for resetting the pull rod 51 is provided between the limit step and the mounting base 6. The pull rod in this embodiment includes a first pull rod and a second pull rod, the first pull rod is mainly used to drive the first driving member and the second driving member, and the second pull rod is provided with a corresponding rack portion 511, wherein the first pull rod is rectangular and flat as a whole, and the second pull rod is relatively thin, so that a limit step is formed at the connection between the first pull rod and the second pull rod, and the pull rod reset spring 56 is located between the limit step and the mounting base 6, and when the applied force on the release knob disappears, the pull rod will be reset to the initial position under the action of the pull rod reset spring 56.

[0050] In this embodiment, the transmission assembly includes a transmission worm 35 and a transmission worm wheel 34. The transmission worm 35 is connected to the driving motor. The transmission worm wheel 34 is mounted outside the rotating screw 20 and is coaxial with the rotating screw 20. The clutch device is arranged between the transmission worm wheel 34 and the rotating screw 20. In this embodiment, the clutch device is mainly used to cut off the power connection between the transmission worm wheel 34 and the rotating screw 20.

[0051] For the clutch device and the self-locking device, the specific structure of this embodiment is as follows:

[0052] Combination Figure 4 and Figure 5As shown, the specific structure of the clutch device in this embodiment is as follows: the clutch device includes a ball sleeve 31, a spline sleeve 32, and a coupling gear sleeve 33. The ball sleeve 31 is mounted on the rotating screw 20 through a flat position and rotates synchronously with the rotating screw 20. A plurality of balls are provided on the outer periphery of one end of the ball sleeve 31. The spline sleeve 32 is mounted outside the ball sleeve 31. The spline sleeve 32 is always meshed with the transmission worm gear 34. The spline sleeve 32 and the ball sleeve 31 are not directly connected. The coupling gear sleeve 33 is used to connect or disconnect the spline sleeve 32 and the ball sleeve 31. The coupling gear sleeve 33 can move axially relative to the rotating screw 20.

[0053] like Figure 5 As shown, in this embodiment, the inner wall of the coupling sleeve 33 is provided with a spline groove 331 matching the spline sleeve 32, that is, the coupling sleeve 33 always rotates synchronously with the spline sleeve 32, and the inner wall of the coupling sleeve 33 is also provided with a ball groove 332 matching the ball on the ball sleeve 31. When the coupling sleeve 33 moves axially toward the ball on the ball sleeve 31, the ball docks into the ball groove 332, so that the coupling sleeve 33 and the ball groove 332 are matched and docked, thereby completing the torque transmission between the coupling sleeve 33 and the ball sleeve 31. Therefore, at this time, the coupling sleeve 33 is equivalent to connecting the rotating screw 20 and the transmission worm gear 34, as shown in FIG. Figure 4 The state shown is the state where the coupling sleeve 33 and the ball sleeve 31 have been docked. When the coupling sleeve 33 moves away from the ball, the coupling sleeve 33 and the ball sleeve 31 are separated, so that the torque transmission between the coupling sleeve 33 and the rotating screw 20 is disconnected.

[0054] The structure of the self-locking device in this embodiment includes a first friction sleeve 41, a second friction sleeve 42, a release torsion spring 43, and a self-locking torsion spring 44. The second friction sleeve 42 is sleeved outside the first friction sleeve 41, and the outer end face of the first friction sleeve 41 is against the inner end face of the second friction sleeve 42. The first friction sleeve 41 and the rotating screw 20 are positioned by flat position, that is, in the circumferential direction, the first friction sleeve 41 and the rotating screw 20 rotate synchronously, and the second friction sleeve 42 is free to rotate relative to the rotating screw 20. In the axial direction, the outer end face of the first friction sleeve 41 is against the inner end face of the second friction sleeve 42. At the same time, the release torsion spring 43 is sleeved on the second friction sleeve 42, and the release torsion spring 43 always holds the second friction sleeve 42 in the initial state. The first friction sleeve 41 is sleeved with a self-locking torsion spring 44. The advantage of this self-locking device is that the installation space is smaller, mainly in that the axial space will be smaller, which is conducive to reducing the volume of the entire electric push rod.

[0055] When the inner tube 14 in the electric push rod is extended normally, the driving motor drives the rotating screw 20 to rotate forward through the clutch device. When the inner tube 14 is extended to a predetermined position, the driving motor stops. At this position, when the inner tube 14 has a tendency to retract, the axial end faces of the first friction sleeve 41 and the second friction sleeve 42 are against each other. Since the self-locking torsion spring 44 has a holding resistance effect on the first friction sleeve 41, and the second friction sleeve 42 is also held by the release torsion spring 43 under normal conditions, when the end faces of the first friction sleeve 41 and the second friction sleeve 42 are against each other, friction resistance is generated between the two, and the friction resistance generates resistance to the rotating screw 20 to prevent it from reversing, so as to complete the self-locking force.

[0056] When the electric push rod needs to be retracted normally, the driving motor drives the rotating screw 20 to rotate in the opposite direction through the clutch device. At this time, the rotation torque of the rotating screw 20 will overcome the self-locking force provided by the self-locking device, and the rotating screw 20 will continue to reverse.

[0057] When the electric push rod is extended to a predetermined position and needs to be quickly retracted, the present embodiment can unlock the self-locking device to achieve the purpose of quick release. The unlocking in the present embodiment is mainly achieved by a second driving member, and the specific structure is as follows: the second driving member includes a push block 52, and the push block 52 and the pull rod are preferably an integrated structure, that is, in the present embodiment, the self-locking device and the clutch device share a pull rod 51, the push block 52 is provided with a guide surface 521, the release torsion spring 43 includes a radially extending pin 431, and the guide surface 521 is provided on the side of the push block 52. When the pull rod 51 is pulled, the guide surface 521 on the push block 52 The second friction sleeve 42 will rotate synchronously with the first friction sleeve 41 when the end faces of the first friction sleeve 41 and the second friction sleeve 42 are against each other, so that the first friction sleeve 41 will not generate any resistance to the rotating screw rod 20, thereby achieving the purpose of rotating the screw rod 20 without resistance. At this time, if the clutch device is disconnected and the self-locking device is also unlocked, the rotating screw rod 20 is basically in a free idling state in this state, and the transmission nut 21 can be quickly retracted.

[0058] In addition, in this embodiment, the release method of using the guide surface 521 to gradually push the torsion spring 43 can achieve the purpose of gradually reducing the self-locking force so that the self-locking force does not disappear immediately, thereby achieving the purpose of stepless adjustment.

[0059] In view of the presence of a clutch device and a self-locking device in this embodiment, the axial force transmission of this embodiment is as follows:

[0060] When the inner tube 14 of the electric push rod extends to the predetermined position and has a tendency to retract, the axial force of the inner tube 14 is transmitted to the transmission nut 21, and the transmission nut 21 transmits the axial force to the rotating screw 20. The rotating screw 20 will be subjected to the axial force, and the ball sleeve 31 is against the shoulder position of the rotating screw 20. Therefore, the axial force of the rotating screw 20 is transmitted to the ball sleeve 31 at the first time, and the end face of the ball sleeve 31 is against the end face of the first friction sleeve 41, that is, the ball sleeve 31 is axially limited by the first friction sleeve 41, so the axial force will be transmitted to the first friction sleeve 41, and the tail end face of the first friction sleeve 41 is against the inner end face of the second friction sleeve 42, so the axial force is transmitted to the second friction sleeve 42, and a tapered roller bearing 25 is provided between the tail end face of the second friction sleeve 42 and the tail pull head 15, so the axial force is finally transmitted to the tail pull head 15 through the tapered roller bearing 25.

[0061] In this embodiment, the ball sleeve 31, the first friction sleeve 41, and the second friction sleeve 42 together constitute an axial limit kit. The rotating screw 20 transmits the axial force to the tail pull head 15 through the axial limit kit. From the perspective of the entire axial force transmission process, the coupling gear sleeve 33 in this embodiment will never be affected by the axial force, so it is also very labor-saving when moving the coupling gear sleeve 33.

[0062] At the same time, since the clutch device is not subjected to the axial force from the rotating screw 20, the service life of the clutch device can be greatly improved. Of course, it should be noted that if there is no self-locking device in the electric push rod, a structure similar to a sleeve can be additionally provided on the rotating screw 20 as an axial limit kit.

[0063] In this embodiment, the first friction sleeve 41 preferably includes a front sleeve and a rear sleeve, and a thrust bearing is used to abut the middle of the front sleeve and the rear sleeve in the axial direction. In other embodiments, the first friction sleeve 41 can be in the form of an integrated sleeve.

[0064] The structure of the first driving component of this embodiment: the first driving component includes a rocker rod 53, and the rocker rod 53 is connected to the pull rod 51. During installation, the upper end of the rocker rod 53 is rotatably connected to the pull rod 51. Specifically, a notch is provided at the bottom of the pull rod 51, and the top of the rocker rod 53 is positioned in the notch. The middle of the rocker rod 53 is rotatably installed on a rocker rod sleeve 531, and the lower end of the rocker rod 53 is connected to the coupling gear sleeve 33. When the pull rod 51 is pulled, the rocker rod 53 swings to push the coupling gear sleeve 33 to move axially.

[0065] In order to better optimize the operation of the clutch device and the self-locking device, the operation sequence of the clutch device and the self-locking device is optimized in this embodiment:

[0066] like Figure 2 and Figure 3As shown in, in the initial state, the guide surface 521 of the push block 52 needs to move a certain stroke before it will contact the pin 431 of the release torsion spring 43. This stroke can be understood as the idle stroke of the push block 52. During this idle stroke, the clutch device is operating normally. The purpose of this is that the coupling sleeve 33 will be moved first, and at the same time, when resetting, the self-locking device will self-lock first, and then the clutch device will perform power connection. The advantage of this is that after the self-locking device generates a self-locking force, the rotation speed of the rotating screw 20 will decrease, so that when the coupling sleeve 33 engages with the ball sleeve 31, the coupling sleeve 33 and the ball sleeve 31 will not be damaged, which can greatly extend the service life.

[0067] It should be noted that the structure of the self-locking device and the clutch device is not limited to the structure shown in the present embodiment. Taking the self-locking device as an example, the self-locking device may only include a single third friction sleeve, which rotates synchronously with the rotating screw 20. The release torsion spring 43 is mounted on the third friction sleeve. In the initial state, the release torsion spring 43 holds the third friction sleeve tightly to generate resistance to the rotating screw 20, which is equivalent to the release torsion spring 43 being a self-locking torsion spring 44. When the release torsion spring 43 is pushed by the push block 52, the resistance of the release torsion spring 43 to the third friction sleeve disappears. Taking the clutch device as an example, the clutch device may be realized by a combination of other spline sleeves 32 and splines.

[0068] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. An electric push rod with a hand-twist release device, comprising a housing, a drive motor, a transmission assembly, a rotating screw and a transmission nut, wherein the drive motor drives the rotating screw to rotate through the transmission assembly, and the rotating screw drives the transmission nut to move along the axial direction of the rotating screw, characterized in that: The transmission assembly includes a transmission worm and a transmission worm wheel, and the electric push rod also includes: The clutch device is provided between the transmission assembly and the rotating screw rod, and is used to connect or cut off the power transmission between the transmission assembly and the rotating screw rod; A self-locking device, which generates frictional resistance to the rotating screw when the rotating screw is reversed, and the self-locking device includes a release torsion spring for unlocking the self-locking device; A hand-turned release device is arranged on the housing, and includes a first drive member, a second drive member and a release knob for driving the first drive member and the second drive member, the first drive member is connected to the clutch device, the second drive member is used to connect the self-locking device, and the release knob presents an initial state and a fully released state through rotational movement. In the process from the initial state to the fully released state, the first drive member drives the clutch device to disconnect the power connection, and the second drive member drives the release torsion spring to loosen; the hand-turned release device also includes a pull rod that can move axially along the rotating screw, the pull rod is provided with a rack portion, and the release knob is connected to a release gear that meshes with the rack portion; the second drive member includes a push block, the push block is provided on the pull rod or integrated with the pull rod, the push block is provided with a guide surface, and the release torsion spring includes a radially extending pin, when the pull rod moves axially, the guide surface on the push block contacts the pin to expand the release torsion spring outward.

2. The electric push rod with a hand-twist release device as claimed in claim 1, characterized in that: The electric push rod comprises an outer tube and an inner tube which is telescopic relative to the outer tube, a mounting base is mounted on the outer tube, the release knob is rotatably mounted on the mounting base, and the pull rod is at least partially slidably mounted on the mounting base.

3. The electric push rod with a hand-twist release device as claimed in claim 2, characterized in that: The pull rod is provided with a limiting step, and a pull rod reset spring for resetting the pull rod is provided between the limiting step and the mounting base.

4. The electric push rod with a hand-twist release device as claimed in claim 1, characterized in that: The first driving member comprises a swing rod rotatably arranged relative to the housing, and the pull rod drives the swing rod to rotate when the pull rod moves axially, and the swing rod swings to axially push the clutch device.

5. The electric push rod with a hand-twist release device as claimed in claim 1, characterized in that: The transmission worm is connected to the driving motor, the transmission worm wheel is sleeved outside the rotating screw, and the clutch device is arranged between the transmission worm wheel and the rotating screw.

6. The electric push rod with a hand-twist release device as claimed in claim 5, characterized in that: The clutch device comprises a coupling gear sleeve, the transmission worm wheel is provided with a tooth groove matching with the coupling gear sleeve for transmission, and the coupling gear sleeve is sleeved on the rotating screw and can move axially relative to the rotating screw.

7. The electric push rod with a hand-twist release device as claimed in claim 1, characterized in that: The self-locking device comprises a first friction sleeve and a second friction sleeve, the first friction sleeve and the second friction sleeve are respectively sleeved on the rotating screw, and the axial end faces of the first friction sleeve and the second friction sleeve are against each other, the first friction sleeve rotates synchronously with the rotating screw, and the second friction sleeve rotates freely relative to the rotating screw, the first friction sleeve is sleeved with a self-locking torsion spring, and the release torsion spring is sleeved on the second friction sleeve; or, the self-locking device comprises a third friction sleeve, the third friction sleeve rotates synchronously with the rotating screw, and the release torsion spring is sleeved on the third friction sleeve.

8. The electric push rod with a hand-twist release device as claimed in claim 1, characterized in that: During the process of the hand-twist release device returning from the fully released state to the initial state, the second drive member first disengages from the release torsion spring on the self-locking device to generate a self-locking force. After the release torsion spring returns, the first drive member disengages from the clutch device accordingly.

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