CN218000315U - A linear actuator with a contact safety nut and an aerial work platform - Google Patents

Abstract

The utility model relates to the technical field of high-altitude work platforms, in particular to a linear driver with a contact safety nut and an high-altitude work platform. The linear driver includes a central screw and a transmission nut mechanism and a safety nut mechanism that cooperate with it. The transmission nut mechanism Engaged transmission with the central screw; wherein, an elastic ball mechanism is provided between the safety nut mechanism and the central screw, and the safety nut mechanism is always kept in engagement with the central screw through the elastic ball mechanism. The contact safety nut enables the linear actuator to always maintain safety and stability without loss of precision during the conversion process when the transmission nut mechanism fails and the safety nut mechanism intervenes to play a role.

Description

A linear drive and aerial work platform with a contact safety nut

technical field

The utility model relates to the technical field of high-altitude work platforms, in particular to a linear driver with a contact safety nut and a high-altitude work platform.

Background technique

Linear actuators are currently widely used in various fields, including medical equipment, home office, solar power generation and so on. The structure of this linear actuator usually includes a driving motor, a driving screw, a worm wheel, and a driving nut. The driving motor drives the rotating screw to rotate, and when the rotating screw rotates, it drives the driving nut to move axially. achieve the driving purpose. During operation, the linear actuator not only needs to bear the axial force, but also needs to bear a certain lateral force, so that the drive nut is damaged due to abnormal wear and material defects, resulting in a sudden drop, which is very dangerous. In order to improve the use of The safety performance of many linear actuators is provided with a safety nut in the drive nut. The setting of the safety nut is not to keep the push rod running after the thread or ball of the drive nut is damaged, but to allow the push rod to drop to a safe position. When the drive nut is in normal operation, the safety nut is ineffective, so the safety nut is usually not engaged with the screw at this time; and when the drive nut is damaged during the upward process, the linear actuator will not continue to rise, but rotate at the original position , if the motor reverses, the drive by means of the safety nut allows the linear actuator to return to a safe position.

Because the safety nut is only engaged with the screw rod to play a role when the screw rod fails, the safety nut does not work when the screw lift is in normal operation, and the safety nut does not engage with the screw rod and does not affect the screw rod normal operation of the lift. A lifting device disclosed in a patent with publication number CN113840794A includes a central screw, a main nut mechanism and an auxiliary nut mechanism, the main nut mechanism engages with the central screw, and the auxiliary nut mechanism separates from the central screw, In the event of a failure of the primary nut mechanism, the secondary nut mechanism is configured to engage the central screw, avoiding a dangerous rapid descent of the hoist, and the hoist controller is then configured to allow the work platform to be lowered for stowage or transport position to allow workers or operators to exit the vehicle safely. The auxiliary nut mechanism in this patent can be engaged with the central screw to ensure safety when the main nut mechanism fails, but the auxiliary nut mechanism always breaks away from the central screw when the main nut mechanism is in normal operation. The moment of engagement with the central screw will produce a relatively severe impact, which may cause damage to the central screw and the auxiliary nut mechanism, and will cause relatively severe vibrations to the actuator, and the lifted platform will also vibrate, endangering the personnel on the platform In addition, when the auxiliary nut mechanism works, the lifting device does not directly remain at the current position and wait for maintenance, the actuator still needs to run to complete the current lifting task, or at least needs to descend to a safe height, while the auxiliary nut The mechanism and the central screw are joined by helical threads, specifically, they approach and engage with each other along the axial direction of the central screw. Although the original gap is not large, the actuator will still be in the axial direction of the central screw after engagement. An obvious position error is produced, resulting in a large error in the entire lifting control.

Utility model content

The utility model makes improvements to the problems existing in the above-mentioned prior art, that is, the technical problem to be solved by the utility model is to provide a linear actuator with a contact safety nut, including a central screw and a transmission nut mechanism and a safety nut that cooperate with it. A nut mechanism, the transmission nut mechanism is engaged with the central screw for transmission; wherein, an elastic ball mechanism is provided between the safety nut mechanism and the central screw, and the safety nut mechanism is always kept in contact with the central screw through the elastic ball mechanism. Engagement of the central screw. The drive nut mechanism, such as a conventional ball screw nut, converts the rotational actuation of the central screw into translational motion. In the normal working state of the drive nut mechanism without failure, compared with the prior art where the safety nut mechanism remains disengaged from the central screw, the patented safety nut mechanism always maintains elastic engagement with the central screw through a specially constructed elastic ball mechanism , which means contact safety nut. When the drive nut mechanism fails, the elastic ball mechanism does not affect the snap engagement of the safety nut mechanism with the central screw rod.

As a preference of the present utility model, the central screw has a spiral raceway, the safety nut mechanism includes a safety nut seat sleeved on the periphery of the central screw, and the safety nut seat is provided with a limit point pointing to the central screw. channel, the elastic ball mechanism includes an elastic buffer provided in the limit channel and a safety ball provided between the elastic buffer and the central screw, and the safety ball partially falls on the screw The raceway is partly located in the limiting hole, and the safety ball can roll along the spiral raceway and move along the limiting hole.

As a preference of the present invention, the safety nut seat is provided with a plurality of limiting channels along the circumference, and each of the limiting channels is provided with the elastic buffer and the safety ball.

As a preference of the present invention, the inner wall of the safety nut seat has a helical crest, and the helical crest protrudes into the spiral raceway and is spaced from the central screw.

As a preference of the present invention, the limiting hole is filled with oil, and the cross-sectional diameter of the limiting hole is consistent with the diameter of the safety ball.

As a preference of the present utility model, the limiting channel runs through the inner and outer walls of the safety nut seat, the safety ball blocks the outlet of the limiting channel close to the central screw, and the limiting channel is far away from the A plunger is detachably installed at the entrance of the central screw, and the plunger blocks the entrance of the limiting hole, and the elastic buffer is located between the plunger and the safety ball.

As a preference of the present utility model, there is a gap between the safety nut seat and the transmission nut mechanism and an oil supply chamber is formed, and the oil supply chamber surrounds the central screw rod, and the safety nut seat is opened to communicate with the The limit hole and the transfer hole of the oil supply chamber.

As a preference of the present utility model, the limiting holes are arranged in a circular array on the screw top teeth along the circumferential direction of the safety nut seat.

As a preference of the present invention, the outlets of all the limiting holes are arranged along the helical extension direction of the helical crown.

As a preference of the present invention, the elastic buffer is a spring, and the diameter of the spring is smaller than that of the safety ball.

An aerial work platform includes the linear driver with a contact safety nut.

Beneficial effect:

The design of the contact safety nut enables the linear actuator to always maintain safety and stability without loss of precision during the conversion process when the transmission nut mechanism fails and the safety nut mechanism intervenes.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram that described transmission nut mechanism and safety nut mechanism are installed on the central screw rod;

Fig. 2 is the schematic diagram of safety nut seat and central screw rod;

Fig. 3 is the sectional view of Fig. 1;

Fig. 4 is a schematic diagram omitting the plunger and the elastic buffer in Fig. 3;

Fig. 5 is a schematic diagram showing that the outlet of the limiting hole is located on the helical top;

Fig. 6 is a schematic diagram of the outlets of all the limiting holes arranged on the helical apex along the helical extension direction of the helical apex;

Fig. 7 is the general structure schematic diagram of described scissor lifting equipment;

Fig. 8 is a schematic diagram of the working of the hydraulic buffer;

Fig. 9 is a structural schematic diagram of the hydraulic buffer;

Figure 10 is a schematic diagram of the lower connection end;

Figure 11 is a schematic diagram of the upper connection end;

In the figure: 1, central screw, 11, spiral raceway, 2, drive nut mechanism, 3, safety nut mechanism, 31, safety nut seat, 32, limiting hole, 33, elastic buffer, 34, safety ball, 35 , screw top tooth, 36, plunger, 37, transfer hole, 38, oil supply cavity; 4, scissor mechanism, 41, horizontal strut, 42, scissor frame, 5, hydraulic buffer, 51, hydraulic cylinder, 52, piston rod, 53, dust cover, 6, lower connecting end, 61, lower arc seat, 62, lower arc groove, 63, lower opening and closing part, 64, mounting piece, 7, upper connecting end, 71, Upper arc seat, 72, upper arc groove, 73, upper opening and closing part, 81, lower fastener, 82, upper fastener, 9, hoisting mechanism.

detailed description

The following specific examples are only explanations of the utility model, and it is not a limitation of the utility model. Those skilled in the art can make modifications without creative contribution to the present embodiment as required after reading this description, but as long as they are within the utility model All new claims are protected by patent law.

Embodiment one:

The utility model provides a linear actuator with a contact safety nut, which includes a central screw 1 and a transmission nut mechanism 2 and a safety nut mechanism 3 that cooperate with it, and the transmission nut mechanism 2 is engaged with the central screw 1 for transmission; wherein An elastic ball mechanism is provided between the safety nut mechanism 3 and the central screw 1, and the safety nut mechanism 3 is always engaged with the central screw 1 through the elastic ball mechanism.

Further, the central screw 1 has a spiral raceway 11, the safety nut mechanism 3 includes a safety nut seat 31 sleeved on the periphery of the central screw 1, there is no contact between the safety nut seat 31 and the central screw 1, the The safety nut seat 31 is provided with a limiting hole 32 pointing to the center screw 1, and the elastic ball mechanism includes an elastic buffer 33 provided in the limiting hole 32 and the elastic buffer 33 is connected to the center. The safety ball 34 provided between the screw rods 1; the end of the elastic buffer 33 away from the safety ball 34 can be supported, specifically, it can be fixedly connected with the inner wall of the limiting hole 32, or it can be a limiting The end of the hole 32 away from the central screw 1 is closed and there is a bottom surface, and the elastic buffer 33 directly abuts against this bottom surface; the safety ball 34 partially falls in the spiral raceway 11 and partially lies in the limiting hole 32 , the safety ball 34 can roll along the spiral raceway 11 and can move along the limiting hole 32, the safety ball 34 and the spiral raceway 11 are completely fitted, the safety ball 34 can be in the spiral Smooth rolling in raceway 11. When the linear actuator is in normal operation, the transmission nut mechanism 2 plays the main transmission role, and the safety nut mechanism 3 does not work but still needs to travel with the transmission nut. In the safety nut mechanism 3, only the safety ball 34 falls in the center The screw 1 is in the spiral raceway 11 and can roll along the spiral raceway 11, and the rest of the safety nut mechanism 3 is not in contact with the central screw 1, but the safety nut mechanism 3 is engaged with the central screw 1 through the safety ball 34 The safety ball 34 is located between the elastic buffer 33 and the central screw 1, and when subjected to an external force, the safety ball 34 can overcome the elastic force of the elastic buffer 33 and move in the limiting hole 32, so the safety ball 34 is not tightly pressed on the screw roller. In the track 11, it only rolls along the spiral raceway 11, so the existence of the safety ball 34 will not affect the normal operation of the drive nut mechanism 2. When the drive nut mechanism 2 breaks down, it is usually the failure caused by the loss of balls in the drive nut mechanism 2; at this time, in the axial direction along the central screw 1, the safety ball 34 in the safety nut mechanism 3 is tightly pressed On the side wall of the spiral raceway 11, the safety ball 34 itself fits perfectly with the spiral raceway 11, so the safety ball 34 has no displacement in the axial direction. There is no instantaneous violent impact, which ensures the stability of the entire linear drive, and also avoids damage to the safety ball 34 and the central screw 1; and part of the safety ball 34 is located in the limit hole 32, so it can be locked by locking the limit The hole 32 is used to limit the displacement of the safety nut seat 31 in the axial direction, so that the safety nut mechanism 3 will not cause a position error in the axial direction of the linear actuator when the safety nut mechanism 3 is working, and the safety ball 34 also acts as a substitute at this time The lost balls in the transmission nut mechanism 2 act temporarily as a transmission, so that the linear actuator can still complete the current lifting task, or descend to a safe height. 2, there is no need to re-calibrate the accuracy. On the side perpendicular to the axial direction of the central screw 1, the safety nut seat 31 is pressed toward the central screw 1, and the safety ball 34 will overcome the elastic force of the elastic buffer 33 and move into the limiting hole 32, and the elastic buffer 33 will act as a buffer function, to avoid the violent vibration of the safety nut mechanism 3, avoid the severe vibration of the linear drive, and ensure the safety of the lifting equipment, but in this direction, the safety ball 34 cannot be pressed tightly in the spiral raceway 11, and the safety nut seat 31 directly Pressing on the central screw rod 1 plays a locking role of the safety nut mechanism 3 on the central screw rod 1 to ensure safety. In short, the design of the contact safety nut enables the linear actuator to always maintain safety and stability without loss of precision during the conversion process when the transmission nut mechanism 2 fails and the safety nut mechanism 3 intervenes to play a role.

In this embodiment, the limiting channel 32 is directed to the central screw 1. Specifically, the extending direction of the limiting channel 32 is perpendicular to the axial direction of the central screw 1. Each limiting channel 32 in the safety nut mechanism 3 There is only one safety ball 34 in the center, so in order to ensure the overall effect of the safety nut, in this embodiment, the safety nut seat 31 is preferably provided with a plurality of limiting holes 32 along the circumference, and each of the limiting holes The elastic buffers 33 and the safety balls 34 are arranged in the position holes 32 . In this embodiment, the safety nut mechanism 3 mainly relies on the direct extrusion between the safety nut seat 31 and the central screw 1 to resist the lateral force and play a locking role, but the inner wall of the safety nut seat 31 and the central screw 1 is smooth If the lateral force is small, the locking effect is average, and the effect on the axial locking effect is very general. Therefore, in this embodiment, the inner wall of the safety nut seat 31 preferably has a helical crown 35, and the helical apex 35 extends into the spiral raceway 11 and is spaced from the central screw 1, and the transmission nut mechanism 2 is normal. During operation, the screw top teeth 35 do not contact the central screw rod 1; and when the drive nut mechanism 2 breaks down, the safety ball 34 still plays the above-mentioned role, and the safety nut seat 31 no longer directly squeezes the central screw rod 1, but The helical top teeth 35 are squeezed into the spiral raceway 11 of the central screw 1, so that the helical top teeth 35 can directly press the central screw 1 in the lateral direction, and the locking effect is good, and at the same time, the safety ball can also be shared in the axial direction. 34 to ensure the strength and reliability of the safety nut mechanism 3.

When the drive nut mechanism 2 is in normal operation, the safety ball 34 is not tightly pressed in the spiral raceway 11, and rolls in the spiral raceway 11, so it will not cause serious problems to the normal operation of the drive nut mechanism 2. However, the friction between the safety ball 34 and the spiral raceway 11 will still have a slight impact on the normal operation of the drive nut mechanism 2, especially the operating efficiency, accuracy and energy consumption. Therefore, in this embodiment, it is preferable that the limiting hole 32 is filled with oil, the cross-sectional diameter of the limiting hole 32 is consistent with the diameter of the safety ball 34, and the outer ring of the safety ball 34 is completely attached to the limiting hole 32. The inner wall of the inner wall, the safety ball 34 blocks the limit hole 32 to limit the effect of the safety nut seat 31. The movement of the safety ball 34 in the limit hole 32 is fully restricted by the limit hole 32, which is very stable, and the safety ball 34 blocks the limit hole 32 to prevent the oil from directly flowing out of the limit hole 32; while the oil is in direct contact with the surface of the safety ball 34, the safety ball 34 with oil on the surface rolls in the spiral raceway 11, and the oil rises Lubrication can reduce the frictional force between the safety ball 34 and the spiral raceway 11, and further reduce the influence of the safety nut mechanism 3 on the normal operation of the transmission nut mechanism 2. In addition, the oil in the limiting hole 32 can also play a certain buffering effect on the safety ball 34, further improving the shock absorbing effect.

As a further improvement, in this embodiment, it is preferred that the limiting hole 32 penetrates the inner and outer walls of the safety nut seat 31, and the safety ball 34 blocks the exit of the limiting hole 32 close to the central screw 1, and the limiting hole 32 The position hole 32 is detachably installed with a plunger 36 away from the entrance of the center screw 1, and the plunger 36 blocks the entrance of the limit hole 32, and the elastic buffer 33 is located between the plunger 36 and the position hole. Between the above-mentioned safety balls 34, the stop hole 32 penetrates and the design of the plunger 36 can facilitate the installation of the elastic buffer 33 and the safety ball 34, and can also facilitate the filling of oil; when installing, first install the safety nut seat 31 OK, then put the safety ball 34 and the elastic buffer 33 into the limiting hole 32 in sequence, then pour the oil, and finally install the plunger 36 in the entrance of the limiting hole 32 to block, the installation is very convenient, no need The elastic buffer 33, the safety ball 34 and the safety nut seat 31 are made together during production, which reduces the manufacturing cost and maintenance cost; the oil will be continuously lost during use, and when it is necessary to add oil, just disassemble it Plunger 36, replenish and pour oil liquid then, install plunger 36 again, continue to use. Preferably, the plunger 36 and the limiting hole 32 are threaded.

The screw top teeth 35 can effectively improve the locking ability of the safety nut mechanism 3, but in actual operation, when the safety nut mechanism 3 works, the linear actuator still needs to run to complete the current lifting task, or to descend to In terms of safety height, under the action of the driving force, it is required that the helical top teeth 35 on the safety nut mechanism 3 can slide along the spiral raceway 11 to realize the advancement of the safety nut mechanism 3 . In this embodiment, it is preferred that there is a gap between the safety nut seat 31 and the transmission nut mechanism 2 and an oil supply chamber 38 is formed. The oil supply chamber 38 surrounds the central screw 1, and the safety nut seat 31 is provided with The transfer hole 37 connecting the limiting hole 32 and the oil supply chamber 38 is filled with oil in the limit hole 32, the transfer hole 37 and the oil supply chamber 38 when the oil is filled, and the oil supply chamber 38 The oil directly flows into the helical raceway 11 of the central screw 1, reducing the friction between the helical top teeth 35 and the helical raceway 11, so that the safety nut mechanism 3 can be driven more easily when it works. Driven by force, it travels along the central screw 1.

In this embodiment, it is preferred that the limiting channels 32 are arranged in a circular array along the circumference of the safety nut seat 31, which refers to the planar arrangement of the limiting channels 32 in the viewing angle along the axial direction of the central screw 1. In practice, these limiting channels There may be spacing between the bit holes 32 in the axial direction of the central screw 1 , but they are not in a cross section. This embodiment is further improved, preferably, the outlets of all the limiting holes 32 are arranged on the screw top teeth 35 along the spiral extension direction of the screw top teeth 35, so that all safety balls 34 are also Arranged along the helical extension direction of the helical top teeth 35, so that the safety ball 34 and the helical top teeth 35 are combined to play their respective roles at the same position of the helical raceway 11, and simultaneously play an axial role at the same position. The upper and side locking functions improve the locking effect. In this embodiment, the elastic buffer 33 is a spring, and the diameter of the spring is smaller than the diameter of the safety ball 34. The two do not need to be connected before, and they can interact with each other directly against each other, which is convenient for installation and transmission of force. works well.

The utility model relates to an aerial work platform, which includes the linear driver with a contact safety nut. When the safety nut mechanism 3 in the linear driver works, it is safe and stable, and the accuracy is not lost, which can ensure that the aerial work platform is in contact with linear actuators. It is still safe and stable with good precision when the drive fails. The aerial work platform described above may be a common aerial work platform such as a scissor-type aerial work platform and an aerial work platform with a loading platform.

Embodiment two:

The utility model is a kind of scissor lifting equipment with a hydraulic buffer 5 for maintenance, including a hydraulic buffer 5 and a scissor mechanism 4, the hydraulic buffer 5 includes a hydraulic cylinder 51 and a piston rod 52, and the hydraulic cylinder 51 It has a lower connecting end 6, and the piston rod 52 has an upper connecting end 7. After the hydraulic buffer 5 is engaged with the scissor mechanism 4 through the upper connecting end 7 and the lower connecting end 6, it can support the Scissor mechanism4. The hydraulic buffer 5 is used for support. When the scissor mechanism 4 exerts pressure on the hydraulic buffer 5, the piston rod 52 will be gradually pressed into the hydraulic cylinder 51. In this process, the buffering capacity of the hydraulic buffer 5 itself is utilized. Strong and strong load capacity, the hydraulic buffer 5 is not only safe and stable when supporting the scissor mechanism 4, but also resists impact with cushioning performance, avoiding damage to itself and the scissor mechanism 4, and the maximum load that can be satisfied Larger, even only the hydraulic buffer 5 can be used for support during actual maintenance, and there is no need to start the hoisting mechanism 9 to provide additional support force, which can effectively save energy during the generally long maintenance process. In this embodiment, the hydraulic shock absorber 5 has a lower connection end 6 and an upper connection end 7 specially connected with the scissors mechanism 4, and the joint is firm enough to further ensure safety.

The scissor mechanism 4 includes two groups of scissor frames 42 at the front and rear and a cross strut 41 erected between the two groups of scissor frames 42, and the cross strut 41 is on the left and right sides of the scissor mechanism 4. Arranged along the up and down direction; when the scissor frame 42 is unfolded, the cross struts 41 on the same side are away from each other in the up and down direction, and when the scissor frame 42 shrinks, the cross struts 41 on the same side are close to each other in the up and down direction; The hydraulic buffer 5 is arranged between two vertically adjacent horizontal struts 41 in one side of the horizontal strut 41, and is connected with the upper horizontal strut 41 through the upper connecting end 7, and connected with the upper horizontal strut 41 through the lower connecting end 6. The lower cross struts 41 are connected, and the whole scissors mechanism 4 is supported through the support of these two cross struts 41 . The hydraulic shock absorber 5 may be damaged, and the load capacity of the hydraulic shock absorber 5 required in different actual situations is also different. In both cases, the hydraulic shock absorber 5 needs to be replaced, so the lower connecting end 6 and the The joint form between the cross struts 41 is a detachable fixation.

As for the specific joint form between the hydraulic buffer 5 and the cross strut 41, in this embodiment, the lower connecting end 6 preferably includes a lower arc-shaped seat 61, and the lower arc-shaped seat 61 has a function that can be completely attached to the cross strut. The lower arc groove 62 for engagement is realized on the outer wall of the pole 41; both ends of the lower arc seat 61 are rotatably connected with a lower opening and closing portion 63, and the lower opening and closing portion 63 is arc-shaped and can be completely attached to On the outer wall of the cross strut 41 , the ends of the two lower opening and closing parts 63 are connected with lower fasteners 81 , and the lower fasteners 81 can connect the ends of the two lower opening and closing parts 63 Pull towards each other to lock. The lower arc-shaped seat 61 is a one-piece molded part with high structural strength and plays a major supporting role. The cross strut 41 is a circular rod, and the shape of the lower arc groove 62 matches the shape of the outer wall of the cross strut 41. , the lower arc-shaped seat 61 half-wraps the cross strut 41 through the lower arc groove 62, and the engagement relationship is very stable and reliable; while the lower opening and closing part 63 makes the lower connecting end 6 completely encircle the cross strut 41, further improving the engagement. Firmness, when the lower fastener 81 is locked, it has the force to pull the ends of the two lower opening and closing parts 63 towards each other, so that the two lower opening and closing parts 63 tighten the cross strut 41 . When installing, the two lower opening and closing parts 63 are in an open state. After the lower arc-shaped seat 61 is engaged with the cross strut 41, the two lower opening and closing parts 63 are hooped to the cross strut 41, and the lower fasteners are used to 81 for locking.

If the two lower opening and closing parts 63 are in contact with the two ends after the cross struts 41 are hooped, there is actually interference between the two, and no matter how the lower fastener 81 increases the locking force, the It is difficult to act on the two lower opening and closing parts 63, so in this embodiment, after the two lower opening and closing parts 63 are completely attached to the outer wall of the horizontal strut 41, the two lower opening and closing parts 63 There is an interval between the ends; in this way, when the lower fastener 81 increases the locking force, the clamping force between the lower opening and closing part 63 and the cross strut 41 can be improved, and the locking effect is further improved. After locking, the lower connection It is difficult for the end 6 to move relative to the cross strut 41, so it can be considered that it has reached a fixed state. The end of the lower opening and closing part 63 has a mounting piece 64 for the installation of the lower fastener 81. The mounting piece 64 is vertical up and down, and the locking force generated by the lower fastener 81 is perpendicular to the mounting piece 64. , the lower fastener 81 pulls the two mounting pieces 64 to improve the transmission effect of the lower fastener 81 on the locking force and further improve the locking effect. Preferably, the lower fastener 81 includes a bolt and a nut, and the mounting piece 64 is provided with a through hole for the bolt to pass through. force.

In this embodiment, the upper connecting end 7 includes an upper arc-shaped seat 71, and the upper arc-shaped seat 71 has an upper arc groove 72 that can be completely attached to the outer wall of the cross strut 41 to achieve engagement; Both ends of the upper arc-shaped seat 71 are rotatably connected with an upper opening and closing portion 73. The upper opening and closing portion 73 is arc-shaped and can be completely attached to the outer wall of the horizontal strut 41. The two upper openings An upper fastener 82 is connected to the ends of the closing portion 73, and the upper fastener 82 can pull the ends of the two upper opening and closing portions 73 toward each other to achieve locking. The functions of the upper arc-shaped seat 71 , the upper opening and closing portion 73 and the upper fastener 82 are consistent with those of the lower arc-shaped seat 61 , the lower opening and closing portion 63 and the lower fastener 81 respectively, and the installation principles are also consistent. Of course, it can be further preferred that there is an interval between the ends of the two upper opening and closing parts 73 after the cross strut 41 is hooped, and the ends of the two upper opening and closing parts 73 all have mounting pieces 64 for the installation of the upper fastener 82, so as to better The locking function of the upper fastener 82 is fully exerted. The composition of the upper fastener 82 is also consistent with that of the lower fastener 81 .

The hydraulic shock absorber 5 is only supported during maintenance. When the scissor lift equipment works normally, the hydraulic shock absorber 5 does not work and can be directly removed through the lower connection end 6 and the upper connection end 7, but usually the equipment There is no extra place to place it on the phone, and it must be removed every time it is used up, which is too cumbersome. Therefore, in this embodiment, one of the scissor frames 42 is preferably provided with a storage box with an opening facing upward on the side wall of the other scissor frame 42. When the lower fastener 81 is loosened, the lower connecting end 6 can move along the cross strut 41 towards the scissor frame 42 with the storage box, and the lower fastener 81 can rotate relative to the cross strut 41 to make the hydraulic shock absorber 5 fall into the storage box. When in use, the hydraulic shock absorber 5 is usually located in the middle of the cross strut 41 for better support, while the storage box is set on the side wall of the scissor frame 42, which is a directly fixed connection relationship, and the closer it is, the higher the firmness , and can avoid interference with the lifting mechanism 9; so when storing the hydraulic shock absorber 5, first release the engagement of the upper connecting end 7 and the cross strut 41, and then loosen the nut in the lower fastener 81 to make the lower The opening and closing part 63 no longer tightens the cross strut 41, and the lower connecting end 6 can move or rotate relative to the cross strut 41, first moving towards the scissor frame 42 provided with the storage box until the hydraulic buffer 5 is aligned with the storage box , and then the lower connection end 6 is rotated relative to the cross strut 41, and the hydraulic buffer 5 falls into the storage box to realize storage. Further, it is preferable that the opening of the storage box is provided with a detachable cover plate. When the hydraulic buffer 5 is stored in the storage box, the cover plate is installed to prevent the hydraulic buffer 5 from detaching from the storage box and affecting the normal operation of the equipment. .

Since the piston rod 52 will enter and leave the hydraulic cylinder 51 when the hydraulic buffer 5 is working, in order to prevent impurities from entering the hydraulic cylinder 51 through the gap and affecting the normal operation of the hydraulic cylinder 51, it is preferred in this embodiment that the hydraulic buffer 5 also includes a A dust cover 53 at one end of the hydraulic cylinder 51, the dust cover 53 is fixed on the piston rod 52, and the dust cover 53 can follow the piston rod 52 to move relative to the hydraulic cylinder 51, preventing The dust cover 53 surrounds one end of the hydraulic cylinder 51 on the circumferential side, one side of the axial side is sealed and fixed to the piston rod 52 , and the other side of the axial direction is open for the hydraulic cylinder 51 to extend into. In this way, the dust cover 53 can prevent impurities from entering the hydraulic cylinder 51 . The hydraulic buffer cylinder has a maximum load. If it exceeds this load, it will be damaged and invalidated. Therefore, in this embodiment, the outer wall of the hydraulic cylinder 51 is preferably provided with a warning scale. When the dust cover 53 moves, its lower edge A visible distance change is generated between the warning scale and the hydraulic buffer 5 reaches the maximum load when the lower edge of the dust cover 53 reaches the warning scale. When using the hydraulic buffer 5, it is first necessary to use the lifting mechanism 9 to raise the scissor mechanism 4, so that the distance between the upper and lower adjacent horizontal struts 41 is greater than the total length of the initial state of the hydraulic buffer 5, and then the hydraulic buffer The device 5 is supported from the storage box, and the upper arc groove 72 in the upper arc-shaped seat 71 of the upper connection end 7 is most aligned with the upper horizontal strut 41, and then the lowering function module of the lifting mechanism 9 is started to drive the scissor mechanism 4 Shrink down, let the cross strut 41 enter in the upper arc groove 72, continue to descend to make the hydraulic buffer 5 support the cross strut 41. In the process of continuing to descend, it is necessary to allow the lifting mechanism 9 to stop descending in time before the lower edge of the dust cover 53 exceeds the warning scale, so as to avoid damage to the hydraulic buffer 5 . Only the scissor mechanism 4 presses on the hydraulic buffer 5 like this, usually the load that the hydraulic buffer 5 can bear.

But in actual operation, the operator will forget to close the hoisting mechanism 9 if he does not pay attention, the hoisting mechanism 9 continues to descend, the hydraulic buffer 5 bears the pressure of the scissor mechanism 4 and the thrust of the hoisting mechanism 9, and waits until the dust cover 53 The edge exceeds the warning scale, and the hydraulic shock absorber 5 is damaged. Therefore, it is preferred in this embodiment that the scissor lifting device also includes a lifting mechanism 9, a controller and a switch, and the lifting mechanism 9 supports the scissor mechanism 4 and has the function of pushing the scissor mechanism 4 to expand or contract The rising function module and the falling function module; the switch is arranged on the hydraulic buffer 5, and the switch can be triggered when the lower edge of the dust cover 53 reaches the warning scale; the controller can receive the The signal of the above-mentioned switch can control the lifting mechanism 9 to stop the descending action, so as to avoid the damage of the hydraulic buffer 5. The lifting mechanism 9 adopts the linear driver with contact safety nut described in the first embodiment.

The above is only a specific embodiment of the utility model, but the scope of protection of the utility model is not limited thereto, and any person familiar with the technical field can easily think of various Equivalent modifications or replacements shall all fall within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims (11)

1. A linear actuator with a contact safety nut, including a central screw (1) and a drive nut mechanism (2) and a safety nut mechanism (3) that cooperate with it, the drive nut mechanism (2) and the center The screw (1) is engaged for transmission; it is characterized in that an elastic ball mechanism is provided between the safety nut mechanism (3) and the central screw (1), and the safety nut mechanism (3) is always connected through the elastic ball mechanism Remain engaged with the central screw (1). 2. A linear actuator with a contact safety nut according to claim 1, characterized in that the central screw (1) has a helical raceway (11), and the safety nut mechanism (3) includes a The safety nut seat (31) on the periphery of the central screw (1), the safety nut seat (31) is provided with a limiting hole (32) pointing to the central screw (1), and the elastic ball mechanism includes the The elastic buffer (33) provided in the limiting hole (32) and the safety ball (34) arranged between the elastic buffer (33) and the central screw (1), the safety ball (34) partly falling in the spiral raceway (11) and partly in the limiting hole (32), the safety ball (34) can roll along the spiral raceway (11) and along the The limit hole (32) moves. 3. A linear actuator with a contact safety nut according to claim 2, characterized in that, the safety nut seat (31) is provided with a plurality of limiting holes (32) along the circumference, each Each of the limiting holes (32) is provided with the elastic buffer (33) and the safety ball (34). 4. A linear actuator with a contact safety nut according to claim 2, characterized in that the inner wall of the safety nut seat (31) has a screw top (35), and the screw top (35) Extending into said helical raceway (11) and spaced apart from said central screw (1). 5. A linear actuator with a contact safety nut according to claim 2, characterized in that the limiting hole (32) is filled with oil, and the cross-sectional diameter of the limiting hole (32) is Consistent with the diameter of the safety ball (34). 6. A linear actuator with a contact safety nut according to claim 2, characterized in that, the limiting channel (32) runs through the inner and outer walls of the safety nut seat (31), and the safety ball (34) Blocking the outlet of the limiting channel (32) close to the central screw (1), the limiting channel (32) is detachably installed with a plunger ( 36), the plunger (36) blocks the entrance of the limiting hole (32), and the elastic buffer (33) is located between the plunger (36) and the safety ball (34). 7. A linear actuator with a contact safety nut according to claim 2, characterized in that there is a gap between the safety nut seat (31) and the transmission nut mechanism (2) and forms an oil supply chamber (38), the oil supply chamber (38) surrounds the central screw (1), and the safety nut seat (31) is provided with a channel connecting the limiting hole (32) and the oil supply chamber (38) transport channels (37). 8 . The linear actuator with contact safety nut according to claim 2 , characterized in that, the limiting holes ( 32 ) are arranged in a circular array along the circumferential direction of the safety nut seat ( 31 ). 9. A linear actuator with a contact safety nut according to claim 4, characterized in that, the outlets of all the limiting holes (32) are along the helical extension direction of the helical crown (35) Arranged on the spiral top teeth (35). 10. A linear actuator with a contact safety nut according to claim 2, characterized in that the elastic buffer (33) is a spring, and the diameter of the spring is smaller than the diameter of the safety ball (34) . 11. An aerial work platform, characterized in that it comprises a linear actuator with a contact safety nut according to any one of claims 1-9.

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