Unlocking protection device for cab overturning hydraulic oil cylinder assembly

Abstract

The unlocking protection device comprises a cylinder body which is hinged to the outer side of a turnover oil cylinder and connected with a cylinder body end cover, a plunger cavity and a guide hole are formed in the cylinder body in a penetrating mode, and the side, close to the guide hole, of the plunger cavity is communicated with a short oil pipe. The short oil pipe is connected to a rod cavity and a high-pressure oil way of the overturning oil cylinder through a three-way pipe, the cylinder body end cover is provided with a through hole communicated to a plunger cavity, the through hole is communicated to an air inlet end located at the cylinder body end cover, a plunger penetrating through a guide hole is slidably connected in the plunger cavity, and a first sealing ring and a first check ring are arranged in the guide hole; the end, close to the through hole, of the plunger is provided with a second sealing ring and a second check ring, and the end, away from the cylinder body, of the plunger is hinged to a pawl. According to the hydraulic cylinder assembly, an original stay wire unlocking mode is replaced, potential safety hazards caused by sliding of the piston rod due to internal leakage of the hydraulic cylinder can be avoided, and the safety performance of the hydraulic cylinder assembly in the lifting or descending operation process is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic cylinders, in particular to an unlocking protection device for a cab tilting hydraulic cylinder assembly. Background Art

[0002] The front-end structure of existing commercial trucks is generally a flat-nose type, that is, the cab is arranged above the engine. If the engine compartment needs to be maintained and repaired, the cab needs to be lifted and tilted, so a cab tilting cylinder is required. The tilting cylinder is mainly used to realize the tilting lift and fall of the cab. To ensure the safety of the tilting cylinder during the lift and fall processes, a locking mechanism is used to protect the lift and fall of the tilting cylinder. Generally, an unlocking protection device is required to control the opening and closing of the locking mechanism.

[0003] For example, the patent document with the publication number CN215719914U discloses "a lifting device with a self-locking function". Its locking mechanism includes a mounting seat, a pawl, a locking plate, a torsion spring, and a pull rope. The mounting seat is fixedly installed on the outer wall of the hydraulic cylinder; the pawl is rotatably installed on the mounting seat; the locking plate is slidably installed on the mounting seat, and one end of it is fixedly connected to the piston rod corresponding to the tilting cylinder; several positioning holes are formed in the locking plate along its length direction for cooperating with the pawl, and a pull rope can be used to control the connection between the pawl and the locking plate. However, in this technical solution, the locking plate and the pawl of the locking mechanism often get damaged. After investigation, it is found that maintenance personnel often operate the hydraulic tilting oil pump to control the tilting cylinder to make the cab fall back without operating the pull rope and without disengaging the locking plate and the pawl on the tilting cylinder. Since the locking plate is still stuck in the groove of the pawl at this time, the locking mechanism is not opened, and the pulling force generated by the piston rod of the tilting cylinder will cause damage to the locking plate and the pawl, thereby rendering the locking mechanism ineffective. Summary of the Utility Model

[0004] To solve the technical problem that the locking plate and the pawl of the existing locking mechanism often get damaged, thereby rendering the locking mechanism ineffective, the utility model provides the following technical solutions.

[0005] An unlocking protection device for a cab tilting hydraulic cylinder assembly of the utility model includes a cylinder body connected with a cylinder head cover hinged to the outside of the tilting cylinder. The cylinder body is provided with a plunger cavity and a guiding hole in a penetrating manner. A short oil pipe is communicated with one side of the plunger cavity close to the guiding hole. The short oil pipe is connected to the rodless cavity and the high-pressure oil circuit of the tilting cylinder through a tee pipe. The cylinder head cover is provided with a through hole communicated with the plunger cavity, and the through hole is communicated to the air inlet end located on the cylinder head cover. A plunger slidingly connected in the plunger cavity passes through the guiding hole. A first sealing ring and a first retaining ring are arranged in the guiding hole. A second sealing ring and a second retaining ring are arranged at one end of the plunger close to the through hole. A ratchet pawl is hinged to one end of the plunger away from the cylinder body.

[0006] As a further technical solution, the cylinder body is provided with a through hole communicated with the plunger cavity, and the short oil pipe is welded outside the cylinder body and communicated to the plunger cavity.

[0007] As a further technical solution, the cylinder head cover is provided with an internal thread part, and the cylinder body is provided with an external thread part threadedly connected with the internal thread part. Both the internal thread part and the external thread part are coated with thread fastening glue.

[0008] As a further technical solution, a dust-proof net plug is embedded in the air inlet end.

[0009] The beneficial effects of the utility model: The unlocking protection device of the utility model is integrated on the hydraulic cylinder assembly, which is convenient for operation. A plunger is slidingly connected in the plunger cavity and the guiding hole in the cylinder body. The plunger is hinged to the ratchet pawl, and the plunger cavity is communicated with a short oil pipe. The short oil pipe is communicated to the rodless cavity and the high-pressure oil circuit of the tilting cylinder. By using the principle of plunger oil pressure in the cylinder body, it replaces the original way of unlocking with a wire rope, prevents damage to the locking plate and the ratchet pawl, avoids the failure of the locking mechanism, can avoid potential safety hazards caused by the slippage of the piston rod due to internal leakage of the hydraulic cylinder, and improves the safety performance of the hydraulic cylinder assembly during the lifting or lowering operation. Description of the Drawings

[0010] Figure 1 is the external structure schematic diagram of the utility model;

[0011] Figure 2 is the sectional plane schematic diagram of the utility model;

[0012] In the figure: 1 - cylinder head cover; 101 - air inlet end; 102 - dust-proof net plug; 103 - internal thread part; 104 - through hole; 2 - cylinder body; 201 - external thread part; 202 - plunger cavity; 203 - guiding hole; 3 - short oil pipe; 4 - plunger; 5 - first sealing ring; 6 - first retaining ring; 7 - second sealing ring; 8 - second retaining ring. Detailed Implementation Manner

[0013] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model. It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments may be combined with each other.

[0014] In the description of the present utility model, it should be understood that the terms "upper" and "lower" are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0015] As Figure 1 and Figure 2 shown, a unlocking protection device for a cab tilting hydraulic cylinder assembly of the present utility model is used to control the existing locking mechanism to open or close the existing locking mechanism. It includes a cylinder body 2 hinged to the outside of the tilting cylinder. One side of the cylinder body 2 is connected with a cylinder end cover 1. The cylinder body 2 is integrated on the hydraulic cylinder assembly, which is convenient for workers to operate.

[0016] In a preferred embodiment, the cylinder body 2 is provided with a plunger cavity 202 and a guide hole 203 running through it. A plunger 4 is slidably connected in the plunger cavity 202 and the guide hole 203. One end of the plunger 4 is on one side of the plunger cavity 202, and the other end of the plunger 4 passes through the plunger cavity 202 and the guide hole 203 and extends to the outside of the cylinder body 2. The other end of the plunger 4 is hinged to the existing pawl to replace the pull rope. One side of the plunger cavity 202 close to the guide hole 203 is communicated with a short oil pipe 3. The cylinder body 2 is provided with a through hole communicating with the plunger cavity 202. The short oil pipe 3 is welded to the outside of the cylinder body 2 and communicated with the plunger cavity. The short oil pipe 3 is connected to the rodless cavity and the high-pressure oil circuit of the tilting cylinder through a tee pipe. Thus, when the tilting cylinder lifts or falls back, the hydraulic oil flows in the plunger cavity 202, providing positive oil pressure or reverse oil pressure in the plunger cavity 202, so that the plunger 4 extends or retracts in the plunger cavity 202 to control the locking or unlocking of the pawl to the locking plate.

[0017] In a preferred embodiment, the cylinder block end cover 1 is provided with a through hole 104 communicating with the plunger chamber 202. The through hole 104 communicates with the air inlet end 101 of the cylinder block end cover 1. A dust-proof net plug 102 is embedded in the air inlet end 101. The dust-proof net plug 102 can prevent dust in the air from entering the plunger chamber 202. When hydraulic oil flows in the plunger chamber 202 and provides positive or reverse oil pressure in the plunger chamber 202, due to the different pressures on both sides of the plunger 4 in the plunger chamber 202, the plunger 4 can move linearly to extend or retract.

[0018] In a preferred embodiment, a first sealing ring 5 and a first retaining ring 6 are arranged in the guiding hole 203 to guide the movement of the plunger 4 and keep the plunger 4 in a sealed state with the guiding hole 203. A second sealing ring 7 and a second retaining ring 8 are nested inside the outer wall of one end of the plunger 4 close to the through hole 104 to seal one end of the plunger 4 close to the through hole 104 with the plunger hole 202. The cylinder block end cover 1 is provided with an internal thread portion 103, and the cylinder block 2 is provided with an external thread portion 201 threadedly connected to the internal thread portion 103. The internal thread portion 103 and the external thread portion 201 are both coated with thread fastening glue, which can make the connection between the cylinder block 2 and the cylinder block end cover 1 more stable.

[0019] When the present utility model is in use, when the tipping oil cylinder lifts or descends, under the action of oil pressure, the plunger 4 makes a reciprocating motion of extending or retracting. The plunger 4 drives the pawl to pull it back, so that the pawl is disengaged from the locking plate, and the tipping oil cylinder is unlocked; when the tipping oil cylinder lifts to stop moving, the plunger 4 drives the pawl to extend and cooperate with the locking plate, and the tipping oil cylinder is locked to prevent the hydraulic cylinder from suddenly sliding down.

[0020] The unlocking protection device of this technical solution simplifies the operation of maintenance personnel and effectively avoids the damage of the locking mechanism and potential safety hazards caused by the operation of maintenance personnel. Due to the limited installation space of the heavy truck tipping system, on the premise of not affecting the dimensions and installation relationship of the existing components of the cab tipping system, the added unlocking protection device in this solution is integrated on the hydraulic cylinder, and the device occupies a small space and will not interfere with the existing components, so it has good applicability.

[0021] The above has described in detail the preferred specific embodiments and examples of the present utility model in conjunction with the accompanying drawings. However, the present utility model is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes or equivalent replacements can be made without departing from the concept of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present utility model.

Claims

1. An unlocking protection device for a cab tilting hydraulic cylinder assembly, characterized in that: It includes a cylinder block (2) connected with a cylinder head cover (1) hinged to the outside of a tipping oil cylinder. The cylinder block (2) is provided with a plunger cavity (202) and a guide hole (203) running through it. One side of the plunger cavity (202) close to the guide hole (203) is communicated with a short oil pipe (3). The short oil pipe (3) is connected to the rodless cavity of the tipping oil cylinder and a high-pressure oil circuit through a tee pipe. The cylinder head cover (1) is provided with a through hole (104) communicated with the plunger cavity (202). The through hole (104) is communicated with an air inlet end (101) located on the cylinder head cover (1). A plunger (4) passing through the guide hole (203) is slidably connected in the plunger cavity (202). A first sealing ring (5) and a first retaining ring (6) are arranged in the guide hole (203). A second sealing ring (7) and a second retaining ring (8) are arranged at one end of the plunger (4) close to the through hole (104). A pawl is hinged to one end of the plunger (4) away from the cylinder block (2).

2. The unlocking protection device for the cab tilting hydraulic cylinder assembly according to claim 1, characterized in that: The cylinder block (2) is provided with a through hole communicated with the plunger cavity (202). The short oil pipe (3) is welded outside the cylinder block (2) and communicated with the plunger cavity.

3. The unlocking protection device for the cab tilting hydraulic cylinder assembly according to claim 1, characterized in that: The cylinder head cover (1) is provided with an internal thread part (103). The cylinder block (2) is provided with an external thread part (201) threadedly connected with the internal thread part (103). Both the internal thread part (103) and the external thread part (201) are coated with thread fastening glue.

4. The unlocking protection device for the cab tilting hydraulic cylinder assembly according to claim 1, characterized in that: A dust-proof net plug (102) is embedded in the air inlet end (101).

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