CN219413101U - Hydraulic cylinder with built-in limiting valve - Google Patents

Abstract

The utility model relates to the technical field of hydraulic equipment, in particular to a hydraulic cylinder with a built-in limiting valve; the piston comprises a piston and a limiting valve, wherein the piston is provided with a stepped hole, the limiting valve comprises a screw plug, a spring, a steel ball and a valve rod, the screw plug is connected with the piston and is positioned in the stepped hole, two ends of the spring are respectively connected with the screw plug and the steel ball, the valve rod is connected with the steel ball and penetrates through the piston, one end of the valve rod is extruded, the steel ball is jacked by the valve rod, hydraulic oil at one end of the piston flows to the other end of the piston through the stepped hole at the side surface of the valve rod, the piston loses pressure, the purpose of pressure relief and limiting is achieved, and the effect of avoiding damage to parts caused by impact of the piston to a cylinder cover due to inertia force and hydraulic pressure of the piston is improved.

Description

Hydraulic cylinder with built-in limiting valve

Technical Field

The utility model relates to the technical field of hydraulic equipment, in particular to a hydraulic cylinder with a built-in limiting valve.

Background

The dumper is a special automobile which can incline a carriage by a certain angle through a hydraulic or mechanical lifting mechanism so as to achieve automatic unloading and reset the carriage by means of the dead weight of the cargo box. In the design of a dump truck, a hydraulic cylinder is a key device of the dump truck. The hydraulic cylinder, which is an important executive component in the hydraulic system, plays a role of an executive component in the whole hydraulic machine, and has the function of converting hydraulic energy into linear and swinging reciprocating mechanical motion, and the hydraulic cylinder converts the hydraulic energy into mechanical energy in the whole process. In the process of tipping a carriage of the dump truck, the stroke of the oil cylinder is gradually increased along with the rising of the piston, the distance between the piston and the cylinder cover is reduced, and when the stroke is ended, the piston is in direct contact with the cylinder cover and the movement of the piston is limited only by the cylinder cover, so that the cylinder cover is easy to damage; if the bolts are increased to reinforce the cylinder head, the overall installation space is increased. Therefore, the hydraulic oil pressure pushing the piston to move is timely discharged when the ascending movement stroke of the piston is about to be ended, so that the damage to parts caused by the impact of the piston on the cylinder cover due to the inertia force and the hydraulic pressure of the piston is avoided.

One of the pressure relief devices commonly used in the prior art is to arrange a stop valve in a hydraulic oil way, and cut off the oil way when a piston in an oil cylinder moves to a position where pressure relief is needed, so as to achieve the purpose of pressure relief, but the pressure relief method has a complex structure and unreliable action; the other is that a pressure relief valve is arranged on a piston in the hydraulic cylinder, when the ascending movement stroke of the piston is about to be finished, the pressure relief valve arranged on the piston is in advance contact with a cylinder cover to open the pressure relief valve for pressure relief, so that the mechanical impact of the piston on the cylinder cover is avoided, the common pressure relief valve is a cone valve, a valve rod in the pressure relief valve is easy to fail, and the unloading action is unreliable; the structure has poor effect of avoiding the damage of parts caused by the impact of the piston on the cylinder cover due to the inertia force and the hydraulic force of the piston.

Disclosure of Invention

The utility model aims to provide a hydraulic cylinder with a built-in limiting valve, which solves the problem of poor effect of avoiding damage to parts caused by impact of a piston on a cylinder cover due to inertia force and hydraulic pressure of the piston in the prior art.

In order to achieve the above purpose, the hydraulic cylinder with the built-in limiting valve comprises a piston and the limiting valve, wherein the piston is provided with a stepped hole, the limiting valve comprises a screw plug, a spring, a steel ball and a valve rod, the screw plug is connected with the piston and is positioned in the stepped hole, two ends of the spring are respectively connected with the screw plug and the steel ball, and the valve rod is connected with the steel ball and penetrates through the piston.

The hydraulic cylinder with the built-in limiting valve further comprises a trunnion, a cylinder body, a piston rod and a cylinder cover, wherein the piston is arranged in the cylinder body, the trunnion and the cylinder cover are respectively arranged at two ends of the cylinder body, and the piston rod penetrates through the cylinder cover and is inserted into the piston.

Wherein the valve rod is provided with an oil drain groove.

The hydraulic cylinder with the built-in limiting valve further comprises a first cylindrical protrusion, wherein the first cylindrical protrusion is connected with the trunnion and is located on one side of the trunnion.

The hydraulic cylinder with the built-in limiting valve further comprises a second cylindrical protrusion, wherein the second cylindrical protrusion is connected with the trunnion and is located at one side, far away from the first cylindrical protrusion, of the trunnion.

The utility model relates to a hydraulic cylinder with a built-in limiting valve,

when the piston moves to a stop position, one end of the valve rod is extruded, the valve rod pushes the steel ball away, hydraulic oil at one end of the piston flows to the other end of the piston through the stepped hole at the side surface of the valve rod, so that the piston loses pressure, and the purposes of pressure relief and limiting are achieved; the steel ball is matched and sealed with the inner chamfer of the stepped hole, so that the inner leakage of the oil cylinder is avoided, and the stable operation of the hydraulic oil cylinder with the built-in limiting valve is ensured; when the hydraulic oil cylinder with the built-in limiting valve returns, the steel ball is reset under the action of the spring, so that the action is reliable; the effect of avoiding damage to parts caused by impact of the piston on the cylinder cover due to inertial force and hydraulic force of the piston is obtained.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a hydraulic cylinder with a built-in limiting valve according to the present utility model.

Fig. 2 is a schematic structural view of the limiting valve of the present utility model.

Fig. 3 is a schematic structural view of the trunnion of the present utility model.

1-trunnion, 2-piston, 3-cylinder, 4-piston rod, 5-cylinder cover, 6-plug screw, 7-spring, 8-steel ball, 9-valve rod, 10-first cylinder boss, 11-second cylinder boss, 12-step hole.

Detailed Description

Referring to fig. 1 to 3, fig. 1 is a schematic structural diagram of a hydraulic cylinder with a built-in limiting valve, fig. 2 is a schematic structural diagram of the limiting valve, and fig. 3 is a schematic structural diagram of a trunnion.

The utility model provides a hydraulic cylinder with a built-in limiting valve, which comprises a cylinder body, a cylinder body and a valve body, wherein the cylinder body is provided with a valve body, the valve body is provided with a valve seat, the valve seat is provided with a valve seat, the valve: the piston 2 is provided with a stepped hole 12, the limiting valve comprises a plug screw 6, a spring 7, a steel ball 8 and a valve rod 9, the plug screw 6 is connected with the piston 2 and is positioned in the stepped hole 12, two ends of the spring 7 are respectively connected with the plug screw 6 and the steel ball 8, and the valve rod 9 is connected with the steel ball 8 and penetrates through the piston 2.

In this embodiment, one end of the valve rod 9 is extruded, the valve rod 9 pushes the steel ball 8 open, hydraulic oil at one end of the piston 2 flows to the other end of the piston 2 through the stepped hole 12 at the side surface of the valve rod 9, so that the piston 2 loses pressure, and the purpose of pressure relief and limiting is achieved; the steel ball 8 is matched with the inner chamfer of the stepped hole 12 for sealing, so that the leakage of the cylinder body 3 is avoided, and the hydraulic cylinder with the built-in limiting valve is ensured to run stably; when the hydraulic oil cylinder with the built-in limiting valve returns, the steel ball 8 is reset under the action of the spring 7, so that the action is reliable; an effect of improving the prevention of damage to parts caused by the impact of the piston 2 against the cylinder head 5 due to the inertial force and hydraulic force of the piston 2 is obtained.

Further, the hydraulic cylinder with the built-in limiting valve further comprises a trunnion 1, a cylinder body 3, a piston rod 4 and a cylinder cover 5, the piston 2 is arranged in the cylinder body 3, the trunnion 1 and the cylinder cover 5 are respectively arranged at two ends of the cylinder body 3, and the piston rod 4 penetrates through the cylinder cover 5 and is inserted into the piston 2.

In this embodiment, one end of the valve rod 9 contacts with the cylinder cover 5, the valve rod 9 pushes the steel ball 8 open, hydraulic oil at one end of the piston 2 flows to the other end of the piston 2 through the stepped hole 12 at the side surface of the valve rod 9, so that the piston 2 loses pressure, and the purpose of pressure relief and limiting is achieved; the steel ball 8 is matched with the inner chamfer of the stepped hole 12 for sealing, so that the internal leakage of the oil cylinder is avoided, and the stable operation of the hydraulic oil cylinder with the built-in limiting valve is ensured; when the hydraulic oil cylinder with the built-in limiting valve returns, the steel ball 8 is reset under the action of the spring 7, so that the action is reliable; an effect of improving the prevention of damage to parts caused by the impact of the piston 2 against the cylinder head 5 due to the inertial force and hydraulic force of the piston 2 is obtained.

Further, the valve stem 9 has an oil drain groove.

In this embodiment, one end of the valve rod 9 contacts with the cylinder cover 5, the valve rod 9 pushes the steel ball 8 open, hydraulic oil at one end of the piston 2 flows to the other end of the piston 2 through the oil drain groove and the stepped hole 12 at the side surface of the valve rod 9, so that the piston 2 loses pressure, and the purpose of pressure relief and limiting is achieved.

Further, the hydraulic cylinder with the built-in limiting valve further comprises a first cylindrical protrusion 10, and the first cylindrical protrusion 10 is connected with the trunnion 1 and located at one side of the trunnion 1.

Further, the hydraulic cylinder with the built-in limiting valve further comprises a second cylindrical protrusion 11, and the second cylindrical protrusion 11 is connected with the trunnion 1 and is located at one side of the trunnion 1 away from the first cylindrical protrusion 10.

In this embodiment, the trunnion 1 is adopted, the first cylindrical protrusions 10 and the second cylindrical protrusions 11 on both sides of the trunnion 1 can form a revolute pair with the sub-frame of the dump truck, so that the connecting device is reduced, and the weight is further reduced.

The above disclosure is only a preferred embodiment of the present utility model, and it should be understood that the scope of the utility model is not limited thereto, and those skilled in the art will appreciate that all or part of the procedures described above can be performed according to the equivalent changes of the claims, and still fall within the scope of the present utility model.

Claims (5)

1. A hydraulic cylinder with a built-in limiting valve is characterized in that,

the piston is provided with a stepped hole, the limiting valve comprises a plug screw, a spring, a steel ball and a valve rod, the plug screw is connected with the piston and is positioned in the stepped hole, two ends of the spring are respectively connected with the plug screw and the steel ball, and the valve rod is connected with the steel ball and penetrates through the piston.

2. The hydraulic cylinder with a built-in limit valve according to claim 1, wherein,

the hydraulic cylinder with the built-in limiting valve further comprises a trunnion, a cylinder body, a piston rod and a cylinder cover, wherein the piston is arranged in the cylinder body, the trunnion and the cylinder cover are respectively arranged at two ends of the cylinder body, and the piston rod penetrates through the cylinder cover and is inserted into the piston.

3. The hydraulic cylinder with a built-in limit valve according to claim 1, wherein,

the valve stem has a drain groove.

4. The hydraulic cylinder with a built-in limit valve according to claim 2, wherein,

the hydraulic cylinder with the built-in limiting valve further comprises a first cylindrical protrusion, and the first cylindrical protrusion is connected with the trunnion and is located on one side of the trunnion.

5. The hydraulic cylinder with a built-in limit valve according to claim 4, wherein,

the hydraulic cylinder with the built-in limiting valve further comprises a second cylindrical protrusion, wherein the second cylindrical protrusion is connected with the trunnion and is located at one side, far away from the first cylindrical protrusion, of the trunnion.