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CN-122014709-A - Pressure-reducing overflow valve for pilot handle

CN122014709ACN 122014709 ACN122014709 ACN 122014709ACN-122014709-A

Abstract

The application discloses a pressure-reducing overflow valve for a pilot handle, which comprises a main valve body and two valve core components, wherein the main valve body is provided with two mounting cavities for mounting the valve core components, each mounting cavity is provided with a P port, an A port and a T port, each valve core component comprises a pressure-reducing valve core, a piston rod, a reset spring and a pressure-reducing spring, each piston rod and each pressure-reducing valve core are sequentially coaxially arranged and are all mounted in each mounting cavity, each mounting cavity is provided with a mounting port for extending out one end of each piston rod, each pressure-reducing spring is sleeved on each pressure-reducing valve core, one end of each mounting cavity, far away from each piston rod, forms a dodging hole for the pressure-reducing valve core to stretch out and draw back, one end of each pressure-reducing valve core, far away from a limiting part, is provided with a drain hole, one end of each drain hole is communicated with the T port, and the other end of each drain hole is communicated with the dodging hole of the main valve body. The relief hole arranged on the pressure reducing valve core replaces a hole on the main valve body, so that leakage of oil liquid of the main valve body can be reduced, and the reliability of a system can be enhanced.

Inventors

  • YIN TIEJUN
  • ZOU WEI
  • ZHANG HUAN

Assignees

  • 湖南凯恩利液压机械制造有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (9)

  1. 1. A pressure-reducing overflow valve for a pilot handle is characterized by comprising a main valve body (1) and two valve core components (2), wherein the main valve body (1) is provided with two mounting cavities (11) for mounting the valve core components (2), each mounting cavity (11) is provided with a P port (12), an A port (13) and a T port (14), the A port (13) is positioned between the P port (12) and the T port (14), the valve core components (2) comprise a pressure-reducing valve core (21), a piston rod (22), a return spring (24) and a pressure-reducing spring (25), the piston rod (22) and the pressure-reducing valve core (21) are coaxially arranged in sequence and are mounted in the mounting cavities (11), the mounting cavities (11) are provided with mounting ports (15) for one ends of the piston rod (22) to extend out, the pressure-reducing spring (25) is sleeved on the periphery of the pressure-reducing spring (25), the return spring (24) is sleeved on the periphery of the pressure-reducing spring (25), a pressure-reducing spring seat (24) is arranged between the return spring (24) and the piston rod (22) and the pressure-reducing spring seat (23), one end (21) is provided with a pressure-reducing spring seat (21), the piston rod (22) is provided with a containing hole (221) for containing the limiting part (211), the spring seat (23) can prevent the limiting part (211) from being separated from the containing hole (221), the pressure reducing spring (25) can force the limiting part (211) to prop against the spring seat (23), one end, far away from the piston rod (22), of the mounting cavity (11) forms an avoidance hole (111) for the expansion and contraction of the pressure reducing valve core (21), one end, far away from the limiting part (211), of the pressure reducing valve core (21) is provided with a drainage hole (215), one end of the drainage hole (215) is communicated with the T-shaped opening (14), and the other end of the drainage hole is communicated with the avoidance hole (111) of the main valve body (1).
  2. 2. The relief valve for a pilot handle according to claim 1, further comprising two valve sleeve assemblies (3), wherein the two valve sleeve assemblies (3) are respectively arranged corresponding to the two valve core assemblies (2), the valve sleeve assemblies (3) are installed inside the installation cavity (11), the valve sleeve assemblies (3) comprise a relief valve sleeve (31), an inner limit sleeve (32) and an outer limit sleeve (33) which are sequentially arranged along the axial direction, the outer limit sleeve (33) is positioned at the installation opening (15) of the installation cavity (11), the piston rod (22) is connected with the outer limit sleeve (33) in a penetrating mode, the spring seat (23), the return spring (24) and the relief spring (25) are all positioned inside the inner limit sleeve (32), the relief valve sleeve (31) is in clearance fit with the valve core (21), the inner limit sleeve (32) is provided with a T-shaped through hole (321), the T-shaped through hole (321) is communicated with the T-shaped opening (14), the piston rod (22) is connected with the outer limit sleeve (33) in a penetrating mode, and the relief valve sleeve (31) is provided with the P-shaped through hole (313A) is communicated with the through hole (313A).
  3. 3. The relief valve for a pilot handle according to claim 2, wherein a plurality of pressure equalizing grooves (214) are formed in the outer peripheral surface of the relief valve core (21), a sealing plug (28) is arranged at one end of the relief hole (215) close to the avoidance hole (111), a plurality of radial connecting holes (216) communicated with the closed end of the relief hole (215) are formed in the relief valve core (21), a plurality of communication holes (315) are formed in the relief valve sleeve (31), the communication holes (315) are inclined relative to the center line of the relief valve sleeve (31), one end of each communication hole (315) is communicated with the avoidance hole (111), and the other end of each communication hole is communicated with an inner hole of the relief valve sleeve (31).
  4. 4. A relief and overflow valve for a pilot handle according to claim 3, characterized in that the sealing plug (28) is mounted in a threaded connection, the centre line of the radial connecting hole (216) and the centre of the relief valve core (21) are in a different-plane straight line, and the liquid entering the relief hole (215) from the radial connecting hole (216) can form a rotational flow, the direction of which is the same as the locking direction of the sealing plug (28).
  5. 5. A relief and overflow valve for a pilot handle according to claim 3, characterized in that the dimension of the opening of the communication hole (315) for communicating with the inner hole of the relief valve sleeve (31) in the direction of the center line of the relief valve sleeve (31) is larger than or equal to the minimum distance between the adjacent two pressure equalizing grooves (214).
  6. 6. A relief and overflow valve for a pilot handle according to claim 3, characterized in that said communication holes (315) are provided with at least two, wherein the axial positions of two of said communication holes (315) close to the opening of said relief valve core (21) are mutually staggered, and the total extent is greater than the minimum spacing between adjacent two of said pressure equalizing grooves (214).
  7. 7. A relief and overflow valve for a pilot handle according to claim 3, characterized in that the wall of the inner bore of the relief valve housing (31) is provided with an oil guiding slit (316), both ends of the oil guiding slit (316) have inner end surfaces, and the oil guiding slit (316) communicates with the communication hole (315).
  8. 8. A relief valve for a pilot handle according to claim 2 characterized in that three partition sealing rings (314) are axially arranged at intervals on the relief valve sleeve (31), wherein the partition sealing rings (314) in the middle are used for partitioning the P-port through hole (312) and the A-port through hole (313), the parts of the outer peripheral surface of the relief valve sleeve (31) corresponding to the three partition sealing rings (314) are distributed in a stepped shaft shape, the parts of the relief valve sleeve (31) matched with the partition sealing rings (314) in the middle are arranged as conical surfaces, the parts of the relief valve sleeve (31) matched with the partition sealing rings (314) at two ends are arranged as cylindrical surfaces, the parts of the inner wall of the installation chamber (11) matched with the three partition sealing rings (314) are distributed in a stepped hole shape, the parts of the inner wall of the installation chamber (11) matched with the partition sealing rings (314) in the middle are arranged as conical surfaces, and the parts of the inner wall of the installation chamber (11) matched with the partition sealing rings (314) at two ends are arranged as cylindrical surfaces.
  9. 9. A relief and overflow valve for a pilot handle according to claim 8, characterized in that an elastic washer (34) is arranged between the inner stop collar (32) and the relief valve sleeve (31).

Description

Pressure-reducing overflow valve for pilot handle Technical Field The application relates to the field of excavating engineering machinery, in particular to a pressure reducing overflow valve for a pilot handle. Background The core function of the excavator pilot system is to accurately control the action of the high-pressure main hydraulic system through the low-pressure pilot oil way, so that the sensitive and stable operation of each working device (such as a movable arm, a bucket rod, a bucket, walking, turning and the like) of the excavator is realized. The key control components of the excavator pilot system, which control the action of the high-pressure main hydraulic system through the low-pressure pilot oil way, are two relief valves, the relief valves are switched by utilizing pilot handles, the relief valves are proportional pressure control valves which are usually arranged below the operating handles of the cab, and the control valves can output corresponding control oil pressure according to the stroke of the operating handles of the driver, so that the main control valve core has corresponding movement amount, and the speed of the working device is controlled. The prior pressure-reducing overflow valve shown in fig. 1 mainly comprises a main valve body and two valve core components, wherein the two valve core components are respectively arranged in two installation cavities of the main valve body, the installation cavities of the main valve body are provided with a P port, an A port and a T port, the A port is positioned between the P port and the T port, the valve core components comprise a pressure-reducing valve core, a piston rod, a spring seat, a return spring and a pressure-reducing spring, the piston rod and the pressure-reducing valve core are coaxially arranged in sequence and are all arranged in the installation cavities, the installation cavities are provided with installation ports for extending out one end of the piston rod, when a worker pulls a pilot handle to incline towards one valve core component, the pilot handle pushes the piston rod of the valve core component to move so as to drive the pressure-reducing valve core of the valve core component to overcome the elasticity of the return spring to axially move, so that the valve core component is switched to a working state, and when the pilot handle is at a make a comeback neutral position, the return spring drives the piston rod and the pressure-reducing valve core to move and reset. The principle of the pressure reducing overflow valve for realizing pressure reduction is that the diameter of the pressure reducing valve core is different at two sides of the P port, so that the pressure receiving area of the pressure reducing valve core in oil liquid at two sides of the P port is enabled to enable the pressure reducing valve core to be subjected to axial acting force, the pressure reducing valve core overcomes the elasticity of a pressure reducing spring and axially moves to be retracted into a containing hole reserved at the inner side of a piston rod, and the oil liquid passage of the pressure reducing overflow valve is changed in the process of axially moving the pressure reducing valve core, so that the pressure reducing effect is generated. In order to enable the valve core to move smoothly under the pressure of oil, in the prior art, an installation cavity matched with the pressure reducing valve core on the main valve body is arranged in a penetrating mode at the tail end, so that the installation cavity is communicated with an oil return pipeline of an oil pressure system, an external pipeline connecting point of the main valve body can be increased under the condition, leakage points of the main valve body are correspondingly increased, and the operation reliability of the pressure reducing overflow valve is affected. Disclosure of Invention In order to solve the problem that the leakage possibility of the main valve body is increased due to an external pipeline arranged on the main valve body and adapted to the movement of the pressure reducing valve core, the application provides a pressure reducing overflow valve for a pilot handle. The application provides a pressure-reducing overflow valve for a pilot handle, which adopts the following technical scheme: A pressure reducing overflow valve for a pilot handle comprises a main valve body and two valve core assemblies, wherein the main valve body is provided with two mounting cavities for mounting the valve core assemblies, each mounting cavity is provided with a P port, an A port and a T port, the A port is located between the P port and the T port, each valve core assembly comprises a pressure reducing valve core, a piston rod, a return spring and a pressure reducing spring, the piston rods and the pressure reducing valve cores are coaxially arranged in sequence and are all mounted in the mounting cavities, each mounting cavity is provided with a mounting port for