A hands-free emergency braking device for an engineering vehicle

Abstract

The application belongs to the technical field of engineering vehicles, and discloses a hand-automatic integrated emergency braking device for an engineering vehicle, which comprises a cylinder body, the top end of the cylinder body is provided with a piston rod, the cylinder body and the piston rod are used for controlling the pitch angle of a hoist arm of an engineering hoisting vehicle, further comprises a guide assembly which is fixed to the upper end of the piston rod, and a transmission assembly which is installed at the upper end outside the cylinder body. The application realizes real-time pressure monitoring through the communication between the liquid storage pipe and the hydraulic oil path inside the cylinder body. When the hydraulic pipeline bursts or the overall system loses pressure, the elastic telescopic rod releases and pushes the piston ring to go up, the brake teeth are clamped into the transmission gear teeth to realize mechanical locking, the piston rod movement is constrained through the gear and rack meshing pair, a second mechanical braking defense line which is completely independent of the hydraulic system is formed, automatic triggering is not required, and pure mechanical rigid locking is realized, which is not dependent on hydraulic sealing, and the problem of gradual failure of locking caused by hydraulic leakage is eliminated.

Description

Technical Field

[0001] This invention belongs to the field of engineering vehicle technology, specifically a manual / automatic emergency braking device for engineering vehicles. Background Technology

[0002] Engineering cranes are indispensable key equipment in large-scale infrastructure construction, logistics transportation, and emergency rescue. The pitch angle of their boom is controlled by the luffing cylinder. As the only load-bearing actuator of the boom, the luffing cylinder bears the combined loads of the boom's own weight, the load being lifted, and wind loads during lifting operations. The controllability of its movement and the reliability of its position are directly related to the stability of the entire machine and the safety of the operation. Once the luffing cylinder moves unexpectedly under load, the boom will lose support and fall rapidly, causing a serious safety accident.

[0003] Currently, the safety protection of the luffing cylinder of an engineering crane mainly relies on the balance valve and hydraulic lock in the hydraulic circuit. Under normal operating conditions, the balance valve controls the movement speed of the luffing cylinder through throttling to prevent the boom from falling too quickly due to its own weight. When the high-pressure hose or pipeline of the luffing cylinder bursts, the balance valve locks the working oil from the lower chamber of the cylinder in an attempt to prevent the boom from falling. At the same time, the two-way hydraulic lock is installed on the oil circuit of the two chambers of the cylinder. Through the sealing effect of the check valve, it blocks the pressure oil in the two chambers of the cylinder to prevent the cylinder from shifting due to internal leakage of valve components during the pressure holding process.

[0004] However, the above-mentioned existing technical solutions have the following technical defects: Firstly, the locking functions of both the balance valve and the hydraulic lock rely on the integrity and sealing of the hydraulic circuit. When the pipeline ruptures between the balance valve and the cylinder, although the balance valve has activated, it cannot seal the leak at the ruptured section. The hydraulic oil in the lower chamber of the cylinder will continue to leak through the rupture opening, and the boom will still fall under its own weight. Similarly, the one-way valve seals of the hydraulic lock will age, wear, or become contaminated and stuck after long-term use, leading to a gradual increase in internal leakage. The locking reliability decreases with the use time, and this defect is difficult to detect in a timely manner during routine inspections.

[0005] Secondly, in the event of a complete loss of hydraulic system pressure (such as engine shutdown, hydraulic pump failure, or simultaneous rupture of multiple pipelines), all safety devices that rely on hydraulic pressure fail simultaneously, lacking a second line of defense independent of the hydraulic system. Although some solutions use accumulators as emergency power sources, the energy storage capacity of accumulators is limited, which can only sustain a limited number of operations, and the accumulators themselves are also at risk of leakage and failure. Summary of the Invention

[0006] To address the problems mentioned in the background art, the present invention provides a manual-automatic emergency braking device for engineering vehicles, which solves the two major defects of existing engineering cranes that rely on balance valves and hydraulic locks for the safety protection of the luffing cylinder: the locking fails when the pipeline bursts, and there is no independent second line of defense against hydraulic pressure loss in the event of overall system depressurization.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a manual / automatic emergency braking device for engineering vehicles, comprising a cylinder body, a piston rod disposed at the top of the cylinder body, the cylinder body and the piston rod being used to control the pitch angle of the boom of an engineering crane, and further comprising: A guide assembly, which is fixedly mounted on the upper end of the piston rod; A transmission assembly, which is mounted on the upper end of the cylinder body; A braking assembly, disposed at the bottom of the transmission assembly, is used to brake the piston rod by locking the transmission assembly; The guide assembly includes a connector fixed to the upper end of the piston rod, and racks are fixed to both ends of the connector; The transmission assembly includes a mounting bracket fixed to the upper end of the cylinder body, a spindle mounted on the mounting bracket, and transmission gears that mesh with the rack mounted at both ends of the spindle. The braking assembly includes a liquid storage tube fixed to the bottom of the mounting bracket. A piston ring is movably sleeved inside the liquid storage tube. An elastic telescopic rod is connected to the bottom of the piston ring. A connecting rod is fixed to the top of the piston ring. A support member is fixed to the top of the connecting rod. Braking teeth are provided on both sides of the top of the support member. The braking teeth cooperate with the transmission gear. A connector is installed on the outside of the upper end of the liquid storage tube, and a connecting pipe is provided between the connector and the cylinder body.

[0008] Preferably, the liquid storage pipe forms a hydraulic oil passage with the inside of the cylinder through the connector and the connecting pipe.

[0009] Preferably, a sliding collar is installed at the bottom of each of the two racks, and the sliding collar is movably sleeved on the outside of the cylinder body.

[0010] Preferably, a sealing ring is embedded on the outside of the piston ring, and the piston ring divides the inner cavity of the liquid storage tube into an upper chamber and a lower chamber, and the connecting pipe communicates with the upper chamber above the piston ring.

[0011] Preferably, a limiting ring is fixedly installed on the inner wall of the upper chamber of the liquid storage tube, and the limiting ring is located below the connecting tube; The bottom surface of the limiting ring is located on the upward path of the piston ring, and is used to stop the piston ring to limit its maximum upward stroke.

[0012] Preferably, the connecting pipe is located above the limiting ring to prevent the limiting ring from blocking the oil passage between the connecting pipe and the upper chamber.

[0013] Preferably, the connecting pipe is detachably connected to the connector; After the brake teeth engage with the transmission gear, the connecting pipe is detached from the mating head, and the external oiling device is connected to the mating head. Hydraulic oil is injected into the upper chamber through the external oiling device via the mating head. The oil pressure acts on the piston ring to overcome the elastic force of the elastic telescopic rod, pushing the piston ring downward. The piston ring drives the support and brake teeth downward through the connecting rod, causing the brake teeth to disengage from the transmission gear.

[0014] Preferably, a buffer assembly is installed on the transmission assembly; The buffer assembly includes a rubber roller fixed in the middle of the mandrel, and the outer annular array of the rubber roller has damping grooves.

[0015] Preferably, a buffer spring is fixedly mounted at the center of the top of the support member, and a friction plate is fixedly mounted on the top of the buffer spring. The inner arc surface of the friction plate is adapted to the outer arc surface of the rubber roller.

[0016] Preferably, under normal operating conditions, the elastic telescopic rod is in a compressed state, and the friction plate is separated from the rubber roller and does not contact it; When the cylinder and the upper chamber of the liquid storage pipe lose pressure, the elastic telescopic rod releases and pushes the piston ring upward. The friction plate contacts the outer surface of the rubber roller before the brake teeth, applying frictional damping to the rotation of the rubber roller. Subsequently, the brake teeth mesh with the transmission gear to complete the locking.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves real-time pressure monitoring by connecting the liquid storage pipe to the internal hydraulic circuit of the cylinder. When the hydraulic line bursts or the entire system loses pressure, the elastic telescopic rod releases and pushes the piston ring upward. The braking teeth engage with the teeth of the transmission gear to achieve mechanical locking. The piston rod movement is constrained by the gear and rack meshing pair, forming a second mechanical braking defense line that is completely independent of the hydraulic system. It is automatically triggered without manual intervention and is a purely mechanical rigid locking mechanism that does not rely on hydraulic sealing, thus eliminating the problem of progressive locking failure caused by hydraulic leakage.

[0018] This invention uses a friction plate elastically connected to the support member via a buffer spring. When pressure is lost, the friction plate contacts the rubber roller before the braking teeth. The friction of the arc surface consumes the inertial kinetic energy of the transmission gear and the boom, so that the gear teeth only engage and lock when the gear is in a near-stationary state. This achieves two-stage braking of "flexible deceleration followed by rigid locking", avoiding tooth breakage due to sudden rigid locking of the high-speed gear. The damping groove further increases the friction coefficient and provides elastic buffering in conjunction with the rubber material.

[0019] This invention features a detachable connection between a connecting pipe and a connector. After braking is triggered, oil pressure can be independently established in the upper chamber via an external oil injection device, pushing the piston ring downwards to disengage the brake teeth. Manual reset can be completed without relying on the vehicle's own hydraulic system. At the same time, a limit ring stops the piston ring to limit the maximum upward stroke and prevent excessive meshing of the teeth from causing structural damage. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the side planar structure of the present invention; Figure 2 This is a schematic diagram of the front structure of the present invention; Figure 3 This is a schematic diagram of the disassembled structure of the cylinder block, piston rod, and guide assembly of the present invention; Figure 4 This is a schematic diagram of the external structure of the guide component of the present invention; Figure 5 This is a schematic diagram of the external structure of the transmission assembly, braking assembly and buffer assembly of the present invention; Figure 6 This is a schematic diagram of the cooperative structure of the transmission component, braking component, and buffer component of the present invention; Figure 7 This is a disassembled structural diagram of the transmission assembly, braking assembly, and buffer assembly of the present invention; Figure 8 This is a schematic diagram of the combined structure of the braking component and the buffer component of the present invention.

[0021] In the diagram: 1. Cylinder body; 2. Piston rod; 3. Guide assembly; 31. Rack; 32. Connector; 33. Sliding collar; 4. Transmission assembly; 41. Mounting bracket; 42. Spindle; 43. Transmission gear; 5. Braking assembly; 51. Liquid reservoir; 52. Limiting ring; 53. Piston ring; 54. Elastic telescopic rod; 55. Connecting rod; 56. Connecting joint; 57. Connecting pipe; 58. Support component; 59. Brake teeth; 6. Buffer assembly; 61. Rubber roller; 62. Friction pad; 63. Buffer spring. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1 to 8 As shown, the present invention provides a manual / automatic emergency braking device for engineering vehicles, including a cylinder body 1, a piston rod 2 disposed at the top of the cylinder body 1, the cylinder body 1 and the piston rod 2 being used to control the pitch angle of the boom of the engineering crane, and further including: Guide assembly 3 is fixedly mounted on the upper end of piston rod 2; Transmission assembly 4 is mounted on the upper part of the cylinder body 1. Braking assembly 5, which is located at the bottom of transmission assembly 4, is used to brake piston rod 2 by locking transmission assembly 4; The guide assembly 3 includes a connector 32 fixedly mounted on the upper end of the piston rod 2, and racks 31 are fixedly mounted on both ends of the connector 32. The transmission assembly 4 includes a mounting bracket 41 fixed to the upper end of the cylinder body 1, a spindle 42 is mounted on the mounting bracket 41, and transmission gears 43 that mesh with the rack 31 are mounted on both ends of the spindle 42. The braking assembly 5 includes a fluid storage tube 51 fixedly mounted at the bottom of the mounting bracket 41. A piston ring 53 is movably sleeved inside the fluid storage tube 51. An elastic telescopic rod 54 is connected to the bottom of the piston ring 53. A connecting rod 55 is fixedly mounted at the top of the piston ring 53. A support member 58 is fixedly mounted at the top of the connecting rod 55. Braking teeth 59 are provided on both sides of the top of the support member 58. The braking teeth 59 cooperate with the transmission gear 43. A connector 56 is installed on the outside of the upper end of the liquid storage pipe 51, and a connecting pipe 57 is provided between the connector 56 and the cylinder body 1.

[0024] The liquid storage pipe 51 forms a hydraulic oil passage with the inside of the cylinder 1 through the connector 56 and the connecting pipe 57.

[0025] Both racks 31 are fitted with sliding collars 33 at their bottoms, which are movably fitted around the outside of the cylinder body 1.

[0026] The hydraulic oil in the cylinder 1 is connected to the inside of the cylinder body 1 through the connector 56 and the connecting pipe 57. The liquid storage pipe 51 forms a hydraulic oil passage with the inside of the cylinder body 1 through the connector 56 and the connecting pipe 57. During normal operation, the hydraulic oil in the cylinder body 1 enters the upper end of the liquid storage pipe 51 through the connecting pipe 57 and the connector 56. The oil pressure acts on the piston ring 53 to overcome the elastic force of the elastic telescopic rod 54 and put the elastic telescopic rod 54 in a compressed state. The piston ring 53 moves down to separate the brake teeth 59 from the transmission gear 43. The transmission gear 43 can rotate freely, and the piston rod 2 extends and retracts normally to control the boom pitch. When the hydraulic line bursts or the entire system loses pressure, the oil pressure in the reservoir pipe 51 drops rapidly. The compression force of the elastic telescopic rod 54 is released, pushing the piston ring 53 upward along the reservoir pipe 51. The piston ring 53 drives the support member 58 to move upward through the connecting rod 55. The support member 58 drives the brake teeth 59 to engage with the teeth of the transmission gear 43 to achieve mechanical locking. When the boom attempts to fall under its own weight, the piston rod 2 follows downward and drives the rack 31 to move downward synchronously through the connecting member 32. Since the transmission gear 43 has been locked by the brake teeth 59 and cannot rotate, the linear motion of the rack 31 is constrained by the gear and rack meshing pair, thereby achieving emergency braking of the piston rod 2. This scheme achieves real-time pressure monitoring by connecting the liquid storage pipe 51 to the internal hydraulic oil circuit of the cylinder 1. The elastic telescopic rod 54 serves as an elastic power source independent of the hydraulic system, and the mechanical meshing of the brake teeth 59 and the transmission gear 43 serves as the actuator. This constitutes a second mechanical braking defense line that is completely independent of the main locking circuit of the hydraulic system. Even if the hydraulic line bursts or the system loses pressure completely, the braking response can be automatically triggered without manual intervention. Furthermore, the meshing of the brake teeth 59 and the transmission gear 43 is a purely mechanical rigid locking mechanism that does not rely on hydraulic sealing or valve sealing performance, thus avoiding the problem of gradual locking failure caused by internal hydraulic leakage.

[0027] like Figure 7 and Figure 8 As shown, a sealing ring is embedded on the outside of the piston ring 53. The piston ring 53 divides the inner cavity of the liquid storage tube 51 into an upper chamber and a lower chamber. The connecting tube 57 is connected to the upper chamber above the piston ring 53. A limiting ring 52 is fixedly installed on the inner wall of the upper chamber of the liquid storage tube 51, and the limiting ring 52 is located below the connecting tube 57; The bottom surface of the limiting ring 52 is located on the upward path of the piston ring 53, and is used to stop the piston ring 53 to limit its maximum upward stroke. The connecting pipe 57 is located above the limiting ring 52 to prevent the limiting ring 52 from blocking the oil passage between the connecting pipe 57 and the upper chamber.

[0028] A sealing ring is embedded on the outside of the piston ring 53. The sealing ring ensures the sealing between the piston ring 53 and the inner wall of the liquid storage tube 51, preventing hydraulic oil leakage between the upper and lower chambers. The piston ring 53 divides the inner cavity of the liquid storage tube 51 into an upper chamber and a lower chamber. The connecting pipe 57 is connected to the upper chamber above the piston ring 53, so that the hydraulic oil in the cylinder 1 enters the upper chamber through the connecting pipe 57 and applies downward oil pressure to the piston ring 53, which forms a counterbalance with the upward elastic force of the elastic telescopic rod 54 in the lower chamber. When the hydraulic system loses pressure and the elastic telescopic rod 54 pushes the piston ring 53 upward, the piston ring 53 is stopped at the bottom surface of the limit ring 52. The limit ring 52 restricts the maximum upward stroke of the piston ring 53, preventing excessive meshing between the brake teeth 59 and the transmission gear 43 and causing structural damage. The connecting pipe 57 is located above the limit ring 52 to prevent the limit ring 52 from blocking the oil passage between the connecting pipe 57 and the upper chamber, ensuring that the hydraulic oil passage remains unobstructed throughout the entire stroke range.

[0029] like Figure 7 and Figure 8 As shown, the connecting pipe 57 and the connector 56 are detachably connected; After the brake tooth 59 engages with the transmission gear 43, the connecting pipe 57 is disconnected from the connector 56, and the external oil injection device is connected to the connector 56. Hydraulic oil is injected into the upper chamber through the external oil injection device via the connector 56. The oil pressure acts on the piston ring 53 to overcome the elastic force of the elastic telescopic rod 54, pushing the piston ring 53 to move downward. The piston ring 53 drives the support member 58 and the brake tooth 59 to move downward through the connecting rod 55, so that the brake tooth 59 disengages from the transmission gear 43.

[0030] The connecting pipe 57 is detachably connected to the connector 56. When the hydraulic system is restored or the brake needs to be manually released, the connecting pipe 57 is detached from the connector 56, and the external oil injection device is connected to the connector 56. Hydraulic oil is injected into the upper chamber of the reservoir pipe 51 through the external oil injection device via the connector 56. The oil pressure acts on the piston ring 53 to overcome the elastic force of the elastic telescopic rod 54, pushing the piston ring 53 down along the reservoir pipe 51. The piston ring 53 drives the support member 58 and the brake teeth 59 to move down synchronously through the connecting rod 55, so that the brake teeth 59 disengage from the transmission gear 43, and the brake reset is completed. By setting a detachable connection structure between the connecting pipe 57 and the connector 56, oil pressure can be independently established in the upper chamber through an external oil injection device after the brake is triggered. Manual reset can be completed without relying on the vehicle's own hydraulic system. Even in extreme conditions where the hydraulic system fails completely, the brake can still be released by manual oil injection, ensuring the equipment's recoverability and emergency handling capabilities.

[0031] like Figures 5-8 As shown, a buffer assembly 6 is installed on the transmission assembly 4; The buffer assembly 6 includes a rubber roller 61 fixed in the middle of the spindle 42, and the outer annular array of the rubber roller 61 has damping grooves. A buffer spring 63 is fixedly installed in the middle of the top of the support member 58, and a friction plate 62 is fixedly installed on the top of the buffer spring 63. The inner arc surface of the friction plate 62 is adapted to the outer arc surface of the rubber roller 61. Under normal operating conditions, the elastic telescopic rod 54 is in a compressed state, and the friction plate 62 is separated from the rubber roller 61 and does not contact it. When the cylinder 1 and the upper chamber of the liquid storage pipe 51 lose pressure, the elastic telescopic rod 54 releases and pushes the piston ring 53 upward. The friction plate 62 contacts the outer surface of the rubber roller 61 before the brake teeth 59, applying frictional damping to the rotation of the rubber roller 61. Then the brake teeth 59 mesh with the transmission gear 43 to complete the locking.

[0032] The rubber roller 61 rotates synchronously with the spindle 42. The outer annular array of the rubber roller 61 has damping grooves, which increase the friction coefficient of the outer surface of the rubber roller 61 and enhance the friction braking effect. The friction plate 62 and the rubber roller 61 form an arc-shaped friction fit with surface contact. Under normal working conditions, the elastic telescopic rod 54 is in a compressed state under the action of oil pressure, the piston ring 53 moves down, the friction plate 62 and the rubber roller 61 separate and do not contact each other, the rubber roller 61 rotates freely, and does not affect the normal telescopic operation of the luffing cylinder. When the hydraulic line bursts or the entire system loses pressure, the upper chambers of cylinder 1 and reservoir pipe 51 lose pressure simultaneously. The elastic telescopic rod 54 releases and pushes the piston ring 53 upward. The support member 58 moves upward synchronously with the piston ring 53. Since the friction plate 62 is elastically connected to the support member 58 through the buffer spring 63, the friction plate 62 contacts the outer surface of the rubber roller 61 before the brake teeth 59. During the rotation of the rubber roller 61, the arc-shaped surface friction applies braking damping to it, so that the rotation speed of the spindle 42 and the transmission gear 43 gradually decreases. Then the brake teeth 59 mesh with the transmission gear 43 to complete rigid locking. By setting the buffer braking sequence so that the friction plate 62 contacts the brake teeth 59 before the gear teeth are rigidly engaged, the inertial kinetic energy of the transmission gear 43 and the boom is consumed by frictional damping before the gear teeth are rigidly engaged. This allows the transmission gear 43 to engage with the brake teeth 59 in a near-stationary state, avoiding the risk of violent impact and breakage between the teeth when the high-speed gear is suddenly rigidly locked. At the same time, the rubber material and damping groove of the rubber roller 61 further increase the friction braking effect and provide elastic buffering, realizing a two-stage braking protection of "flexible deceleration first, then rigid locking".

[0033] Working principle and usage process of this invention: Under normal operating conditions, the hydraulic oil in cylinder 1 enters the upper chamber of storage pipe 51 through connecting pipe 57 and connector 56. The oil pressure acts on piston ring 53 to overcome the elastic force of elastic telescopic rod 54, causing elastic telescopic rod 54 to be in a compressed state. Piston ring 53 moves down, and support member 58 moves down synchronously with piston ring 53. Brake teeth 59 separate from transmission gear 43 and do not contact. At the same time, friction plate 62 separates from rubber roller 61 and does not contact. Both transmission gear 43 and rubber roller 61 can rotate freely. Piston rod 2 extends and retracts normally to control boom pitch. When the hydraulic line bursts or the entire system loses pressure, the oil pressure in the upper chamber of the storage pipe 51 drops rapidly. The compression force of the elastic telescopic rod 54 is released, pushing the piston ring 53 upward along the storage pipe 51. When the piston ring 53 reaches the limit ring 52, its maximum stroke is limited by the bottom stop. The piston ring 53 drives the support member 58 to move upward through the connecting rod 55. The friction plate 62 contacts the outer surface of the rubber roller 61 before the brake teeth 59. The friction of the arc surface applies braking damping to the rubber roller 61, causing the spindle 42 and the transmission gear 43 to gradually reduce their speed. Then the brake teeth 59 engage with the teeth of the transmission gear 43 to achieve rigid locking. When the boom attempts to fall under its own weight, the piston rod 2 follows downward and drives the rack 31 to move downward synchronously through the connector 32. The rack 31 drives the transmission gear 43 to rotate through the meshing pair. Since the transmission gear 43 has been locked by the brake teeth 59 and cannot rotate, the linear motion of the rack 31 is completely constrained, thereby achieving emergency braking of the piston rod 2. When the brake is released, disconnect the connecting pipe 57 from the connector 56, connect the external oil injection device to the connector 56, and inject hydraulic oil into the upper chamber through the connector 56. The oil pressure acts on the piston ring 53 to overcome the elastic force of the elastic telescopic rod 54 and push the piston ring 53 downward. The piston ring 53 drives the support 58 and the brake teeth 59 downward through the connecting rod 55. The brake teeth 59 disengage from the transmission gear 43, and the brake reset is completed.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manual / automatic emergency braking device for engineering vehicles, comprising a cylinder (1), wherein a piston rod (2) is disposed at the top of the cylinder (1), and the cylinder (1) and piston rod (2) are used to control the pitch angle of the boom of the engineering crane, characterized in that, Also includes: Guide assembly (3), which is fixedly mounted on the upper end of the piston rod (2); Transmission assembly (4), which is mounted on the upper part of the cylinder body (1); Braking assembly (5), which is disposed at the bottom of the transmission assembly (4), is used to brake the piston rod (2) by locking the transmission assembly (4). The guide assembly (3) includes a connector (32) fixed to the upper end of the piston rod (2), and both ends of the connector (32) are fixed with racks (31). The transmission assembly (4) includes a mounting bracket (41) fixed to the upper end of the cylinder (1), a spindle (42) is mounted on the mounting bracket (41), and transmission gears (43) that mesh with the rack (31) are mounted on both ends of the spindle (42). The braking assembly (5) includes a liquid storage tube (51) fixedly mounted on the bottom of the mounting bracket (41). A piston ring (53) is movably sleeved inside the liquid storage tube (51). An elastic telescopic rod (54) is connected to the bottom of the piston ring (53). A connecting rod (55) is fixedly mounted on the top of the piston ring (53). A support member (58) is fixedly mounted on the top of the connecting rod (55). Braking teeth (59) are provided on both sides of the top of the support member (58). The braking teeth (59) cooperate with the transmission gear (43). A connector (56) is installed on the outside of the upper end of the liquid storage tube (51), and a connecting pipe (57) is provided between the connector (56) and the cylinder (1).

2. The manual / automatic emergency braking device for engineering vehicles according to claim 1, characterized in that: The liquid storage pipe (51) forms a hydraulic oil passage with the cylinder body (1) through the connector (56) and the connecting pipe (57).

3. The automatic emergency braking device for engineering vehicles according to claim 1, characterized in that: The bottom of each of the two racks (31) is equipped with a sliding collar (33), which is movably sleeved on the outside of the cylinder body (1).

4. The manual / automatic emergency braking device for engineering vehicles according to claim 1, characterized in that: The piston ring (53) is fitted with a sealing ring on the outside. The piston ring (53) divides the inner cavity of the liquid storage tube (51) into an upper chamber and a lower chamber. The connecting tube (57) is connected to the upper chamber above the piston ring (53).

5. The manual / automatic emergency braking device for engineering vehicles according to claim 4, characterized in that: A limiting ring (52) is fixedly installed on the inner wall of the upper chamber of the liquid storage tube (51), and the limiting ring (52) is located below the connecting tube (57); The bottom surface of the limiting ring (52) is located on the upward path of the piston ring (53) and is used to stop the piston ring (53) to limit its maximum upward stroke.

6. The manual / automatic emergency braking device for engineering vehicles according to claim 5, characterized in that: The connecting pipe (57) is located above the limiting ring (52) to prevent the limiting ring (52) from blocking the oil passage between the connecting pipe (57) and the upper chamber.

7. The manual / automatic emergency braking device for engineering vehicles according to claim 4, characterized in that: The connecting pipe (57) is detachably connected to the connector (56); After the brake tooth (59) engages with the transmission gear (43) for braking, the connecting pipe (57) is disconnected from the connector (56), and the external oil injection device is connected to the connector (56). Hydraulic oil is injected into the upper chamber through the external oil injection device via the connector (56). The oil pressure acts on the piston ring (53) to overcome the elastic force of the elastic telescopic rod (54) and push the piston ring (53) to move down. The piston ring (53) drives the support (58) and brake tooth (59) to move down through the connecting rod (55), so that the brake tooth (59) disengages from the transmission gear (43).

8. The automatic emergency braking device for engineering vehicles according to claim 1, characterized in that: A buffer assembly (6) is installed on the transmission assembly (4); The buffer assembly (6) includes a rubber roller (61) fixed in the middle of the spindle (42), and the outer annular array of the rubber roller (61) has damping grooves.

9. The manual / automatic emergency braking device for engineering vehicles according to claim 8, characterized in that: A buffer spring (63) is fixedly mounted in the middle of the top of the support member (58), and a friction plate (62) is fixedly mounted on the top of the buffer spring (63). The inner arc surface of the friction plate (62) is adapted to the outer arc surface of the rubber roller (61).

10. The manual / automatic emergency braking device for engineering vehicles according to claim 9, characterized in that: Under normal working conditions, the elastic telescopic rod (54) is in a compressed state, and the friction plate (62) is separated from the rubber roller (61) and does not contact each other; When the cylinder (1) and the upper chamber of the liquid storage pipe (51) lose pressure, the elastic telescopic rod (54) releases and pushes the piston ring (53) upward. The friction plate (62) contacts the outer surface of the rubber roller (61) before the brake teeth (59) do, applying frictional damping to the rotation of the rubber roller (61). Subsequently, the brake teeth (59) mesh with the transmission gear (43) to complete the locking.

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