CN113460875B

CN113460875B - Telescopic mechanism anti-collision device and lifting appliance

Info

Publication number: CN113460875B
Application number: CN202110845106.1A
Authority: CN
Inventors: 周东才; 吴乐尧; 王孝忱
Original assignee: Hunan Sany Port Equipment Co Ltd; Sany Marine Heavy Industry Co Ltd
Current assignee: Hunan Sany Port Equipment Co Ltd; Sany Marine Heavy Industry Co Ltd
Priority date: 2021-07-26
Filing date: 2021-07-26
Publication date: 2023-09-22
Anticipated expiration: 2041-07-26
Also published as: CN113460875A

Abstract

The application relates to the technical field of mechanical equipment, and particularly provides a telescopic mechanism anti-collision device and a lifting appliance, wherein the telescopic mechanism anti-collision device comprises: positioning mechanism and stop gear, positioning mechanism installs on first components of a whole that can function independently, and stop gear installs on the second components of a whole that can function independently, and stop gear constructs: the positioning mechanism is locked when the second split body stretches to a specific position relative to the first split body, and is released when the interaction force of the limiting mechanism and the positioning mechanism is larger than a threshold value. When the second split body moves to a specific position in use, the limiting mechanism can lock the positioning mechanism. When the second split receives the impact in the retraction direction, a part of the impact force received by the second split is received by the limiting mechanism and the positioning mechanism, so that the second split is prevented from receiving all the impact force, the effect of protecting the second split is achieved, and the damage rate of the second split when the second split receives the impact in the retraction direction is reduced to a certain extent.

Description

Telescopic mechanism anti-collision device and lifting appliance

Technical Field

The application relates to the technical field of mechanical equipment, in particular to a telescopic mechanism anti-collision device and a lifting appliance.

Background

At present, as a plurality of transport vehicles are transported in container yard operation sites such as wharfs and railways, and the containers are stacked densely, when the front crane and the stacker are operated, the second split of the lifting appliance system is easy to collide with other vehicles or barriers slightly on the side after extending out. Especially when the larger-size container is hung, the lifting appliance system stretches out and draws back Liang Shen to a longer state, when the lifting appliance system is impacted by the side, the second split and the structure linked with the second split are damaged easily, so that the second split and the structure linked with the second split are required to be maintained and then can be operated again, the operation efficiency is reduced, and the maintenance cost of enterprises is improved.

Disclosure of Invention

In view of the above, the application provides an anti-collision device and a lifting appliance for a telescopic mechanism, which solve the problem that the second split body is easy to damage and the structure linked with the second split body when the second split body is impacted sideways after being elongated.

In a first aspect, the application provides an anti-collision device for a telescopic mechanism, which is suitable for a telescopic mechanism, wherein the telescopic mechanism comprises a first split body and a second split body, and the second split body is arranged on the first split body in a telescopic manner along the length direction of the first split body; wherein, telescopic machanism buffer stop includes: the positioning mechanism is arranged on the first split body; and a limiting mechanism mounted on the second split, the limiting mechanism configured to: the positioning mechanism is locked when the second split body stretches to a specific position relative to the first split body, and is released when the interaction force between the limiting mechanism and the positioning mechanism is larger than a threshold value.

When the positioning mechanism is used, the positioning mechanism can be locked by the limiting mechanism when the second split moves to a specific position, and the limiting effect of the limiting mechanism on the positioning mechanism is equivalent to the limiting effect of the first split on the second split. When the second split receives the impact in the retraction direction, a part of the impact force received by the second split is received by the limiting mechanism and the positioning mechanism, so that the second split is prevented from receiving all the impact force, the effect of protecting the second split is achieved, and the damage rate of the second split when the second split receives the impact in the retraction direction is reduced to a certain extent. When the second segment is coupled to some other mechanism, such as a power assembly, it can also act to protect other structures coupled to the second segment.

With reference to the first aspect, in one possible implementation manner, the limiting mechanism includes: the limiting plate is arranged on the second split body, and one surface of the limiting plate, facing the positioning mechanism, is provided with a limiting groove; when the second split body stretches to a specific position relative to the first split body, the positioning mechanism is clamped into the limiting groove, and when the interaction force between the limiting groove and the positioning mechanism is greater than the threshold value, the positioning mechanism is separated from the limiting groove.

With reference to the first aspect, in one possible implementation manner, the positioning mechanism includes: the positioning pin is arranged on the first split body; the second split body is clamped into the limiting groove towards one end of the limiting plate when the second split body stretches to a specific position relative to the first split body, and the locating pin is separated from the limiting groove when the interaction force of the limiting groove and the locating pin is larger than the threshold value.

With reference to the first aspect, in one possible implementation manner, an end of the locating pin facing the limiting plate has a first inclined plane facing a retraction direction of the second component and a vertical plane facing an extension direction of the second component, and the first inclined plane is inclined from the retraction direction to the extension direction.

With reference to the first aspect, in a possible implementation manner, the positioning mechanism further includes: and the positioning pin is mutually and elastically connected with the first split body through the elastic component.

With reference to the first aspect, in a possible implementation manner, the first split body is provided with a step hole, and the positioning pin passes through the step hole from one side of the first split body to pass through to the other side of the first split body; the positioning mechanism further comprises a nut, wherein the pin body of the positioning pin is provided with external threads, and the nut is screwed on the external threads of the part of the positioning pin penetrating out of the step hole; the elastic assembly comprises a spring, the spring is sleeved on the pin body of the positioning pin, one end of the spring is connected with the pin body of the positioning pin, and the other end of the spring stretches into the step hole and is mutually abutted with the step of the step hole.

With reference to the first aspect, in a possible implementation manner, a surface of the limiting plate facing the positioning mechanism has at least one second inclined surface, and the second inclined surface is disposed adjacent to the limiting groove; one end of the locating pin, which faces the limiting plate, is provided with an arc surface.

With reference to the first aspect, in one possible implementation manner, the limiting mechanism includes: a first boss mounted on the second body; the positioning mechanism comprises: a second boss mounted on the first split; when the second split body extends to a specific position relative to the first split body, the first boss is clamped on the first side of the second boss, and the first side is the side, opposite to the retraction direction of the second split body, of the second boss.

In a second aspect, the present application provides a spreader comprising: a main beam; the telescopic beam is telescopically arranged on the main beam; the telescopic mechanism anti-collision device in any one of the previous implementations; the positioning mechanism is mounted on the main beam, and the limiting mechanism is mounted on the telescopic beam.

The telescopic mechanism anti-collision device in any of the foregoing implementation manners is included in the present aspect, so that the technical effects of any of the foregoing telescopic mechanism anti-collision devices are achieved, and are not described herein.

With reference to the second aspect, in a possible implementation manner, the lifting appliance further includes: the telescopic oil cylinder comprises a cylinder body and an oil rod, wherein the cylinder body is arranged on the main beam, and the oil rod is linked with the telescopic beam.

With reference to the second aspect, in one possible implementation manner, the telescopic cylinder includes: the hydraulic reversing valve adopts a Y-shaped functional hydraulic reversing valve.

Drawings

Fig. 1 is a schematic view of a part of a telescopic mechanism anti-collision device according to an embodiment of the present application.

Fig. 2 is a schematic structural view of a limiting plate in a telescopic mechanism anti-collision device according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of a positioning pin in a telescopic mechanism anti-collision device according to an embodiment of the present application.

Fig. 4 is a schematic structural view of a positioning pin according to an embodiment of the application.

Fig. 5 is a schematic view of the structure of fig. 1 without the positioning pin.

Fig. 6 is a schematic view of a part of a telescopic mechanism anti-collision device according to another embodiment of the present application.

Fig. 7 is a schematic structural diagram of a lifting appliance according to an embodiment of the present application.

Fig. 8 is a schematic view showing a part of the construction of the spreader shown in fig. 7.

Fig. 9 shows a front view of the spreader of fig. 7.

Fig. 10 is a schematic diagram of the hydraulic structure of the Y-functional hydraulic directional valve.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The application provides a telescopic mechanism anti-collision device which is suitable for a telescopic mechanism, as shown in fig. 1, wherein the telescopic mechanism comprises a first split body 1 and a second split body 2, the second split body 2 is arranged on the first split body 1 in a telescopic manner along the length direction of the first split body 1, and when the telescopic mechanism anti-collision device works, the second split body 2 can move in a telescopic manner relative to the first split body 1.

Fig. 1 is a schematic view of a part of a telescopic mechanism anti-collision device according to an embodiment of the present application. In some embodiments, as shown in fig. 1, the telescopic mechanism bump guard includes: a positioning mechanism 3 and a limiting mechanism 4. The positioning mechanism 3 is mounted on the first split 1. The limiting mechanism 4 is installed on the second sub-body 2, and the limiting mechanism 4 is configured to: the positioning mechanism 3 is locked when the second split 2 is extended and contracted to a specific position with respect to the first split 1, and released from each other when the interaction force between the stopper mechanism 4 and the positioning mechanism 3 is greater than a threshold value.

In use, when the second split 2 moves to a specific position, the positioning mechanism 3 can be locked by the limiting mechanism 4, and the limiting effect of the positioning mechanism 3 exerted by the limiting mechanism 4 is equivalent to the limiting effect of the first split 1 on the second split 2. When the second split body 2 is impacted in the retraction direction, part of the impact force borne by the second split body 2 is borne by the limiting mechanism 4 and the positioning mechanism 3, so that the second split body 2 is prevented from bearing all the impact force, the effect of protecting the second split body 2 is achieved, and the damage rate of the second split body 2 when being impacted in the retraction direction is reduced to a certain extent. When the second segment is coupled to some other mechanism, such as a power assembly, it can also act to protect other structures coupled to the second segment. The specific position may be a relative position of the second split body 2 relative to the first split body 1, or a position of the second split body 2 which extends to the longest relative to the first split body 1, or other positions where protection of the second split body 2 is required.

When the impact force makes the interaction force of the limiting mechanism 4 and the positioning mechanism 3 larger than the threshold value, the limiting mechanism 4 does not lock the positioning mechanism 3 any more, the threshold value can be designed in advance, and the threshold value can avoid the damage of the limiting mechanism 4 and the positioning mechanism 3. The protective action of the limiting mechanism 4 and the positioning mechanism 3 on the second split 2 is determined by the threshold value, and the greater the threshold value is, the stronger the protective action is. The threshold value can be reached to the required value in advance by the structural design and material selection of the limiting mechanism 4 and the positioning mechanism 3.

Fig. 2 is a schematic structural view of a limiting plate in a telescopic mechanism anti-collision device according to an embodiment of the present application. In some embodiments, as shown in connection with fig. 1 and 2, the spacing mechanism 4 comprises: the limiting plate 401, the limiting plate 401 is installed on the second split body 2, and one surface of the limiting plate 401 facing the positioning mechanism 3 is provided with a limiting groove 4011. When the second split body 2 stretches to a specific position relative to the first split body 1, the positioning mechanism 3 is clamped into the limiting groove 4011, and when the interaction force between the limiting groove 4011 and the positioning mechanism 3 is greater than a threshold value, the positioning mechanism 3 is separated from the limiting groove 4011.

When the positioning mechanism 3 is clamped into the limiting groove 4011 in use, the limiting groove 4011 plays a limiting role on the positioning mechanism 3, which is equivalent to the limiting role of the first split body 1 on the second split body 2. But the limiting groove 4011 has limited acting force for limiting the positioning mechanism 3, when the second split body 2 is subjected to enough large impact force, and when the acting force applied by the positioning mechanism 3 to the limiting groove 4011 is larger than a threshold value, the positioning mechanism 3 can be separated from the limiting groove 4011, and the mutual locking between the positioning mechanism 3 and the limiting groove 4011 is released.

Fig. 3 is a schematic structural diagram of a positioning pin in a telescopic mechanism anti-collision device according to an embodiment of the present application. In some embodiments, as shown in fig. 1 and 3, the positioning mechanism 3 includes: the positioning pin 301, the positioning pin 301 is mounted on the first split body 1. When the second split body 2 stretches to a specific position relative to the first split body 1, one end of the positioning pin 301, facing the limiting plate 401, is clamped into the limiting groove 4011, and when the interaction force between the limiting groove 4011 and the positioning pin 301 is greater than a threshold value, the positioning pin 301 is separated from the limiting groove 4011. In this embodiment, the positioning pin 301 is snapped into the limit groove 4011 to lock the positioning mechanism 3 and the limiting mechanism 4 to each other. During the process of moving the second split body 2 to a specific position, the positioning pin 301 is continuously close to the limit groove 4011 until the positioning pin is clamped into the limit groove 4011, and the limit groove 4011 locks the positioning pin 301.

Fig. 4 is a schematic structural view of a positioning pin according to an embodiment of the application. In some embodiments, as shown in fig. 4, the end of the positioning pin 301 facing the limiting plate 401 has a first inclined surface 3011 and a vertical surface 3012, the first inclined surface 3011 facing the retraction direction of the second split 2, the vertical surface 3012 facing the extension direction of the second split 2, the first inclined surface 3011 being inclined from the retraction direction toward the extension direction. Under the action of the first inclined surface 3011, when the second split body 2 is impacted in the retracting direction, the positioning pin 301 is more likely to come out of the limit groove 4011 of the limit plate 401. And under the action of the elevation 3012, after the positioning pin 301 is clamped into the limiting groove 4011, the second split body 2 is less prone to moving towards the extending direction.

In some embodiments, referring to the structure of fig. 3, the shape of the end of the locating pin 301 toward the limit plate 401 matches the shape of the limit groove 4011. Specifically, the shape of the end of the positioning pin 301 facing the limiting plate 401 may be hemispherical, ellipsoidal or a part of a sphere.

In some embodiments, as shown in fig. 1, the positioning mechanism 3 further comprises: the elastic component 302, the positioning pin 301 is mutually elastically connected with the first split body 1 through the elastic component 302. In use, the positioning pin 301 can have a certain free movement amount relative to the first split body 1 through the elastic component 302. In the process of enabling the positioning pin 301 to be clamped into and separated from the limiting groove 4011, the interaction force of the limiting groove 4011 and the positioning pin 301 presses the elastic assembly 302, so that the positioning pin 301 moves to be separated from the limiting groove 4011.

Fig. 5 is a schematic view of the structure of fig. 1 without the positioning pin. In some embodiments, as shown in fig. 1 and 5, the first split body 1 is provided with a stepped hole 101, and the positioning pin 301 passes through the stepped hole 101 from one side of the first split body 1 to pass through to the other side of the first split body 1; the positioning mechanism 3 further includes a nut 303, the pin body of the positioning pin 301 has external threads, and the nut 303 is screwed on the external threads of the portion of the positioning pin 301 that passes out of the stepped hole 101. The elastic component 302 comprises a spring, wherein the spring is sleeved on the pin body of the positioning pin 301, one end of the spring is connected with the pin body of the positioning pin 301, and the other end of the spring extends into the stepped hole 101 and is mutually abutted with the step of the stepped hole 101.

When the embodiment is used, the nut 303 plays a limiting role on the positioning pin 301, so that the positioning pin 301 is prevented from falling out of the stepped hole 101 upwards. Under the action of the spring, the positioning pin 301 can move in the up-down direction shown in fig. 1, and in the process that the second split body 1 drives the positioning pin 301 to move towards the limiting groove 4011, the positioning pin 301 is pressed downwards first, and when the positioning pin enters the limiting groove 4011, the spring rebounds the positioning pin 301 upwards, so that the top end of the positioning pin 301 is clamped into the limiting groove 4011. When the second split 1 receives a large impact force in the retraction direction, the limit groove 4011 cannot lock the positioning pin 301 any more, the positioning pin 301 moves downwards to be separated from the limit groove 4011, and after the positioning pin 301 is separated from the limit groove 4011 and is no longer in contact with the limit plate 401, the positioning pin 301 is sprung upwards until the nut 303 abuts against the second split 1. Moreover, the nut 303 is rotated to adjust the spring-to-dowel 301 rebound force, which determines the difficulty of the dowel 301 to disengage from the limit groove 4011, i.e. the preset threshold of the aforementioned interaction force. The greater the repulsive force, the tighter the contact of the positioning pin 301 with the limit groove 4011, the more difficult the positioning pin 301 is to escape from the limit groove 4011. When it is necessary to increase the aforementioned preset threshold value, a spring having a larger elastic force may be replaced, or the nut 303 may be rotated so that the positioning pin 301 moves toward the nut 303.

In some embodiments, as shown in fig. 1, a side of the limiting plate 401 facing the positioning mechanism 3 has at least one second inclined surface 4012, and the second inclined surface 4012 is disposed adjacent to the limiting groove 4011. One end of the positioning pin 301 facing the limiting plate 401 has an arc surface. When the positioning pin 301 is used, in the process that the second split 1 drives the positioning pin 301 to move towards the limiting groove 4011, the second inclined plane 4012 and the cambered surface of the positioning pin 301 are matched with each other, so that the positioning pin 301 can conveniently slide into the limiting groove 4011 more easily.

Fig. 6 is a schematic view of a part of a telescopic mechanism anti-collision device according to another embodiment of the present application. In some embodiments, as shown in fig. 6, the spacing mechanism 4 includes a first boss 402, the first boss 402 being mounted on the second sub-body 2. The positioning mechanism 3 includes a second boss 304, and the second boss 304 is mounted on the first split body 1. When the second sub-body 2 extends to a specific position relative to the first sub-body 1, the first boss 402 is clamped on a first side of the second boss 304, and the first side is a side of the second boss 304 facing away from the retraction direction of the second sub-body 2. In use, when the second sub-body 2 is extended, the first boss 402 collides with the second boss 304, the second sub-body 2 continues to extend toward a specific position, and finally the first boss 402 reaches the left side of the second boss 304, and the second boss 304 limits the first boss 402 to the left side. When the second split 2 is impacted in the retracting direction, the interaction force between the first boss 402 and the second boss 304 is greater than a threshold value, the second boss 304 cannot limit the first boss 402 any more, and the first boss 402 breaks through the limit of the second boss 304 and moves towards the direction pointed by the first side.

Fig. 7 is a schematic structural diagram of a lifting appliance according to an embodiment of the present application. Fig. 8 is a schematic view showing a part of the construction of the spreader shown in fig. 7. The present application also provides a spreader, in some embodiments, as shown in fig. 7 and 8, comprising: main beam 5, telescopic beam 6 and the aforesaid telescopic machanism buffer stop. The telescopic beam 6 is telescopically arranged on the main beam 5. Wherein, telescopic machanism buffer stop's positioning mechanism 3 is installed on girder 5, and stop gear 4 is installed on telescopic girder 6. When the telescopic girder 6 is extended to a specific position, the limiting mechanism 4 locks the positioning mechanism 3. When the lifting appliance works, if the telescopic beam 6 is impacted in the retraction direction, a part of impact force is born by the limiting mechanism 4 and the positioning mechanism 3, the telescopic beam 6 and the main beam 5 are protected, and the telescopic beam 6 and the main beam 5 are prevented from being damaged due to overlarge stress. When the positioning mechanism 3 is separated from the limiting mechanism 4, the positioning mechanism 3 moves along with the telescopic beam 6, and the size of the positioning mechanism 3 is designed in advance so that the positioning mechanism 3 cannot rub against the main beam 5.

In particular, the spreader may also include a turret assembly 10, and the spreader may be mounted on the boom of the crane by the turret assembly 10.

Fig. 9 shows a front view of the spreader of fig. 7. As shown in fig. 9, a telescopic beam 6 may be provided on each of the left and right sides of the main beam 5, and a telescopic mechanism collision preventing device 7 may be installed at the position shown in the drawing. The two telescopic mechanism anti-collision devices 7 correspond to the two telescopic beams 6 on the left side and the right side, and play a role in protecting the two telescopic beams 6 on the left side and the right side respectively. Specifically, the specific position of the telescopic beam 6 when the positioning mechanism 3 is locked by the limiting mechanism 4 may be one or more. For example, the number of specific positions can be two, and the two specific positions can be two states corresponding to the case that a lifting appliance lifts a 20 inch or 40 inch container, so that the stress condition when the lifting appliance lifts the 20 inch or 40 inch container is impacted laterally is improved. The telescopic mechanism collision preventing device 7 is not limited to the position shown in fig. 9, and may be provided above, sideways, or the like of the telescopic beam 6.

In some embodiments, as shown in fig. 7, the spreader further comprises: the telescopic oil cylinder 8, the telescopic oil cylinder 8 includes cylinder body and oil pole, and the cylinder body is installed on girder 5, and oil pole and flexible roof beam 6 linkage. When the telescopic beam is used, the main beam 5 provides support for the cylinder body, and the telescopic cylinder 8 applies force to the telescopic beam 6 so that the telescopic beam 6 can move in a telescopic mode. When the telescopic beam 6 stretches and the telescopic beam 6 is impacted in the retraction direction, if the telescopic mechanism anti-collision device is not arranged, the telescopic cylinder 8 can be subjected to larger impact force, and the telescopic cylinder 8 is easily damaged. When the telescopic beam 6 stretches to a specific position and the positioning mechanism 3 is locked by the limiting mechanism 4, the telescopic mechanism anti-collision device can protect the telescopic beam 6 and the main beam 5 and simultaneously protect the telescopic cylinder 8. In this embodiment, the telescopic mechanism anti-collision device bears a part of impact force, so that the telescopic cylinder 8 is not easy to damage.

In some embodiments, the telescopic ram 8 comprises: the hydraulic reversing valve adopts a Y-shaped functional hydraulic reversing valve. In this embodiment, the reversing valve of the telescopic cylinder 8 adopts a hydraulic reversing valve, and the hydraulic reversing valve has a Y-shaped function, so that a certain floating range is provided after the oil rod extends, and when the telescopic beam 6 is impacted laterally, the oil rod can float in a certain range, and the oil rod is not easy to bend due to the floating of the oil rod. Fig. 10 is a schematic diagram of the hydraulic structure of the Y-functional hydraulic directional valve. Because the length of the oil rod of the telescopic oil cylinder 8 is longer, the telescopic oil cylinder 8 is easy to be unstable and bent after being stressed, and the telescopic oil cylinder 8 is of a precise structure and is easy to be damaged by impact force. Based on this embodiment, when the hoist after the improvement receives side impact, stop gear 4 cooperation positioning mechanism 3 shared a part impact to telescopic cylinder 8's oil pole is in the floating state, receives external force and assaults corresponding follow-up, has consequently protected telescopic cylinder 8's structure, reduces telescopic cylinder 8's damage rate.

The basic principles of the present application have been described above in connection with specific embodiments, however, it should be noted that the advantages, benefits, effects, etc. mentioned in the present application are merely examples and not intended to be limiting, and these advantages, benefits, effects, etc. are not to be considered as essential to the various embodiments of the present application. Furthermore, the specific details disclosed herein are for purposes of illustration and understanding only, and are not intended to be limiting, as the application is not necessarily limited to practice with the above described specific details.

The block diagrams of the devices, apparatuses, devices, systems referred to in the present application are only illustrative examples and are not intended to require or imply that the connections, arrangements, configurations must be made in the manner shown in the block diagrams. As will be appreciated by one of skill in the art, the devices, apparatuses, devices, systems may be connected, arranged, configured in any manner. Words such as "including," "comprising," "having," and the like are words of openness and mean "including but not limited to," and are used interchangeably therewith. The terms "or" and "as used herein refer to and are used interchangeably with the term" and/or "unless the context clearly indicates otherwise. The term "such as" as used herein refers to, and is used interchangeably with, the phrase "such as, but not limited to.

It should also be noted that in the apparatus and device of the present application, the components may be disassembled and/or assembled. Such decomposition and/or recombination should be considered as equivalent aspects of the present application.

The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is to be construed as including any modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims

1. The telescopic mechanism anti-collision device is characterized by being suitable for a telescopic mechanism, wherein the telescopic mechanism comprises a first split body and a second split body, and the second split body is arranged on the first split body in a telescopic manner along the length direction of the first split body;

wherein, telescopic machanism buffer stop includes:

the positioning mechanism is arranged on the first split body; and

the limiting mechanism is installed on the second split body and is configured to: locking the positioning mechanism when the second split body stretches to a specific position relative to the first split body, and releasing the positioning mechanism when the interaction force between the limiting mechanism and the positioning mechanism is larger than a threshold value;

the limit mechanism comprises:

the limiting plate is arranged on the second split body, and one surface of the limiting plate, facing the positioning mechanism, is provided with a limiting groove;

when the second split body stretches to a specific position relative to the first split body, the positioning mechanism is clamped into the limiting groove, and when the interaction force between the limiting groove and the positioning mechanism is larger than the threshold value, the positioning mechanism is separated from the limiting groove;

the positioning mechanism comprises:

the positioning pin is arranged on the first split body;

the second split body is clamped into the limiting groove towards one end of the limiting plate when the second split body stretches to a specific position relative to the first split body, and the locating pin is separated from the limiting groove when the interaction force between the limiting groove and the locating pin is larger than the threshold value;

the end of the locating pin, which faces the limiting plate, is provided with a first inclined plane and a vertical plane, the first inclined plane faces the retraction direction of the second split, the vertical plane faces the extension direction of the second split, and the first inclined plane is inclined from the retraction direction to the extension direction;

the positioning mechanism further includes:

the positioning pin is mutually and elastically connected with the first split body through the elastic component;

the first split body is provided with a step hole, and the locating pin penetrates through the step hole from one side of the first split body to penetrate through the other side of the first split body; the positioning mechanism further comprises a nut, wherein the pin body of the positioning pin is provided with external threads, and the nut is screwed on the external threads of the part of the positioning pin penetrating out of the step hole;

the elastic assembly comprises a spring, the spring is sleeved on the pin body of the positioning pin, one end of the spring is connected with the pin body of the positioning pin, and the other end of the spring stretches into the step hole and is mutually abutted with the step of the step hole;

one surface of the limiting plate facing the positioning mechanism is provided with at least one second inclined surface, and the second inclined surface is arranged adjacent to the limiting groove; one end of the locating pin, which faces the limiting plate, is provided with an arc surface.

2. A spreader, comprising:

a main beam;

the telescopic beam is telescopically arranged on the main beam; and

the telescopic mechanism bump guard of claim 1;

the positioning mechanism is mounted on the main beam, and the limiting mechanism is mounted on the telescopic beam.

3. The spreader of claim 2, further comprising:

the telescopic oil cylinder comprises a cylinder body and an oil rod, wherein the cylinder body is arranged on the main beam, and the oil rod is linked with the telescopic beam.

4. The spreader of claim 3, wherein the telescopic ram comprises:

the hydraulic reversing valve adopts a Y-shaped functional hydraulic reversing valve.