KR101402119B1 - Relief valve of heavy equipment - Google Patents

Abstract

The present invention relates to a relief valve for a heavy construction equipment with a drain port on a main piston without a drain port on a relief valve guide of an existing heavy construction equipment. Thus, the present invention relates to an improved relief valve for heavy construction equipment, which enables users to conveniently reset secondary relief operation pressure caused by the main piston by changing pilot signal pressure (Pi) from the outside including an operation chamber when an option device or a hydraulic device is replaced or a relief operation pressure settings are adjusted; and prevents foreign substances such as moisture, dust, and water from flowing inside through the drain port which is structurally formed on a guide.

Description

Relief Valve Of Heavy Equipment

The present invention relates to a relief valve for construction heavy equipment, and more particularly, to a method for changing a pilot signal pressure Pi from outside, including a cab, when changing an option device, a hydraulic device, The secondary relief operation pressure generated by the main piston can be easily reset, and foreign substances such as moisture, dust, and water can be prevented from flowing into the interior through the drain port formed in the guide And more particularly to a relief valve for a heavy construction equipment.

Generally, in order to improve the work efficiency during the work using the heavy construction equipment including the excavator and the loader, there are many cases where the optional equipment is installed and removed from the work site. At this time, the set pressure (hereinafter referred to as "relief setting pressure") of the required relief valve is reset according to the replaced option apparatus.

The relief valve that controls the pressure of the construction machine and other hydraulic devices is a pressure that functions to maintain the pressure in the hydraulic circuit below the relief set pressure by discharging part or all of the pressure oil when the pressure of the hydraulic circuit reaches the relief setting pressure As one of the control valves, it is possible to adjust the relief setting pressure from the standard pressure to the high pressure through the pilot signal pressure Pi input for its intended use.

Generally, when the initial relief setting pressure is changed, it is inconvenient to set the pressure while observing the pressure gauge directly using a pressure gauge from the outside. In order to solve this inconvenience, a predetermined pilot signal pressure signal pressure It is necessary to change the relief setting pressure of the relief valve by using the apparatus.

FIG. 1 is a cross-sectional view schematically showing a conventional relief valve. As shown in FIG. 1, a conventional relief valve for heavy construction according to the related art includes a pump line P and a tank line A poppet 20 for controlling the flow rate of the fluid flowing from the pump side to the tank side while moving inside the sleeve 10 and a poppet spring 22 for elastically supporting the poppet 20, When a high pressure equal to or higher than a relief setting pressure is generated in the first pressure chamber (d) formed in the first pressure chamber (10), the poppet pilot (30) which drains to the hydraulic tank through the tank line (T) A poppet seat 40 on which the pilot 30 is seated, a poppet pilot spring 38 for resiliently supporting the poppet pilot 30, a piston 50 sliding on the inside of the poppet 20, The piston spring 58, the tank passage 14, A plug 60 connected to the sleeve 10 and formed with a tank flow passage inlet 62, a guide 70 coupled to the plug to control the relief operating pressure generated in the second pressure chamber e, A main piston 80 which variably adjusts the relief operating pressure when supplied with the pilot signal Pi, a plug adjuster 90 which controls the relief operating pressure generated in the second pressure chamber e, A pressure control flow path 84 for connecting the pilot signal pressure Pi by forming a flow path in the main piston 80 so as to form a secondary relief operating pressure which is lower than the initial relief working pressure in the second pressure chamber e, And a drain port 72 formed in the guide 70 to discharge the pressure oil of the third pressure chamber f to the outside .

Since the conventional relief valve has a structure in which the drain port is open to the atmosphere, moisture or foreign matter enters the drain port and causes malfunction of the control relief valve. The spring element and the piston Which causes the elements to be blown, and the leakage phenomenon occurs, which often causes the falling of the working device.

Korean Patent No. 10-0950571 discloses a drain coupler connected to a drain port, but it is not a fundamental solution since there is still a drain port.

The relief valve for construction heavy equipment according to the present invention aims to solve the following problems.

First, by deleting the drain port, it is intended to prevent penetration of external foreign matter or moisture caused by the drain port.

Second, the O-ring installed in the main piston is eliminated to provide a simple relief valve, thereby reducing the time and cost consumed in manufacturing the relief valve.

Third, we want to perform piping connection work without interfering with the pilot port and surrounding elements when exchanging optional equipment or adjusting relief set pressure.

Fourth, if the option is to be replaced or the relief setting pressure adjustment is required, the relief setting pressure should be easily adjusted.

The problems to be solved by the present invention are not limited to those mentioned above, and other solutions not mentioned can be clearly understood by those skilled in the art from the following description.

The relief valve for construction heavy equipment according to the present invention comprises:

For relief valves for construction heavy equipment,

A first pressure chamber formed in the first pressure chamber and having an inlet through which the high pressure hydraulic oil flows from the hydraulic pump and a tank passage through which the hydraulic oil flowing into the inlet port is drained to the hydraulic tank;

A poppet movably installed in the sleeve for controlling the hydraulic fluid flowing from the hydraulic pump to the hydraulic tank;

A poppet spring for elastically supporting the poppet so as to open and close the flow path between the inlet port and the tank flow path;

A poppet pilot for draining the hydraulic oil to the hydraulic tank when a high pressure is generated that exceeds a primary relief operating pressure set in advance in the first pressure chamber;

A poppet pilot spring for resiliently supporting the poppet pilot against the direction in which the poppet pilot is open;

A poppet seat inserted into the sleeve and seating the poppet pilot;

A piston slidably moved in the poppet by the operating pressure introduced from the hydraulic pump through the inlet port and brought into contact with the poppet pilot;

A piston spring elastically supporting the piston against the poppet seat;

A plug coupled to the sleeve to form a tank flow passage opening communicating with the tank flow path, and a guide screwed into the plug to control a relief working pressure occurring in the second pressure chamber;

The pilot signal spring is slidably supported by the guide and supports the one end of the pilot spring when the pilot signal pressure is supplied from the outside, and the pilot pressure spring is compressed to adjust the relief operating pressure variably. Main piston;

A plug adjuster threadably engaged with the guide to control a relief operating pressure generated in the second pressure chamber and supporting the main piston spring such that the main piston is resiliently biased against the poppet pilot spring;

The main piston is moved against the elastic force of the main piston spring by the pilot signal pressure so as to communicate with the internal pressure of the main piston so as to communicate with the internal pressure of the main piston, A pressure control flow path connecting the pilot signal pressure so as to form a secondary relief operating pressure which is lower than the relief working pressure of the pilot signal pressure;

A first coupling nut coupled to the guide and preventing the relief operating pressure from changing after setting; And

And a second fastening nut coupled to the plug adjuster and preventing the relief operating pressure from being changed after the setting,

And a drain path is formed in the main piston so that the fourth pressure chamber and the second pressure chamber in which the main piston spring is installed are communicated with each other.

Further, in the relief valve for heavy construction use according to the present invention, it is preferable that a pressure seal member is installed on the outer circumference of the poppet so as to prevent leakage of the first pressure chamber formed in the sleeve.

In the relief valve for heavy construction use according to the present invention, it is preferable that a pressure seal member is installed on the outer circumference of the guide to prevent leakage of the second pressure chamber formed inside the plug.

The relief valve for construction heavy equipment according to the present invention can be expected to have the following effects.

First, by eliminating the drain port and forming the drain path, it is possible to prevent penetration of external foreign matter and moisture generated due to the drain port.

Second, by providing an easy-to-assemble relief valve by eliminating the O-rings installed in the main piston, the time and cost consumed in manufacturing the relief valve can be reduced.

Third, it is possible to perform the piping connection operation without interfering with the pilot port and peripheral elements during the exchange of the option device or the relief setting pressure adjustment operation.

Fourth, the relief setting pressure can be easily adjusted if the optional equipment is replaced or the relief set pressure adjustment is required.

1 is a schematic view of a conventional relief valve for heavy construction use.
2 is a schematic diagram of a relief valve for heavy construction use according to an embodiment of the present invention.
FIGS. 3 to 4 are schematic views of a relief valve according to an embodiment of the present invention, according to an internal pressure state of the relief valve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a relief valve for heavy construction equipment according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a schematic view of a relief valve for construction heavy equipment according to an embodiment of the present invention, and FIGS. 3 to 4 are schematic views according to an internal pressure state of a relief valve for construction heavy equipment according to an embodiment of the present invention.

In the relief valve for heavy construction equipment according to the embodiment of the present invention,

For relief valves for construction heavy equipment,

A first pressure chamber d is formed in the first pressure chamber d and an inlet 12 through which the high pressure hydraulic oil flows from the hydraulic pump and a tank passage 14 through which the hydraulic oil flowing into the inlet 12 is drained to the hydraulic tank, (10);

A poppet (20) movably installed in the sleeve (10) for controlling hydraulic fluid flowing from a hydraulic pump to a hydraulic tank;

A poppet spring (28) for elastically supporting the poppet (20) so as to open and close the flow path between the inlet port (12) and the tank flow path (14);

A poppet pilot (30) for draining hydraulic oil to a hydraulic tank when a high pressure exceeding a preset first relief operating pressure is applied to the first pressure chamber (d);

A poppet pilot spring (38) for resiliently supporting the poppet pilot (30) against the direction in which the poppet pilot (30) opens;

A poppet seat (40) installed in the sleeve (10) and seating the poppet pilot (30);

A piston 50 slidingly moved within the poppet 20 by the operating pressure introduced from the hydraulic pump through the inlet 12 to contact the poppet pilot 30;

A piston spring (58) for resiliently supporting the piston (50) against the poppet seat;

A plug 60 is connected to the sleeve 10 so as to form an inlet of a tank flow passage 14 communicating with the tank flow passage 14 and a plug 60 to control a relief working pressure generated in the second pressure chamber e, A guide 70 screwed on the guide rail 70;

The pilot pressure spring 38 is inserted into the guide 70 and supports one end of the poppet pilot spring 38. When the pilot signal pressure is supplied from the outside, the pilot pressure spring 38 is slidably moved to adjust the relief operation pressure variably, A main piston (80) having an internal flow passage (82) communicating with a pilot signal pressure;

The main piston (80) is screwed to the guide (70) to control the relief operating pressure generated in the second pressure chamber (e), and the main piston (80) is resiliently biased against the poppet pilot spring A plug adjuster 90 for holding the plug 88;

A flow path is formed at one side of the main piston 80 so as to communicate with the internal flow path 82 of the main piston 80 and the third pressure chamber f inside the guide 70, A pressure control for connecting the pilot signal pressure so that the main piston 80 is moved against the elastic force of the piston spring 88 to form a secondary relief operating pressure in the second pressure chamber e which is lower than the initial relief operating pressure A flow path 84;

A first coupling nut 71 coupled to the guide 70 to prevent the relief operating pressure from being changed after the setting; And

And a second fastening nut (91) coupled to the plug adjuster (90) to prevent the relief operating pressure from being changed after setting,

A drain path 86 is formed in the main piston 80 such that the fourth pressure chamber g in which the main piston spring 88 is installed communicates with the second pressure chamber e. do.

When the high-pressure hydraulic fluid from the hydraulic pump P is introduced into the inlet port 12, the primary relief setting pressure is supported by the main piston 80 so that the pilot poppet 0.0 > 28 < / RTI >

For example, when the relief setting pressure is normally maintained, the hydraulic fluid discharged from the hydraulic pump flows into the first pressure chamber (d) through the orifice in the poppet (20) and the orifice in the piston (50). In this case, the inflowing working pressure acts on the poppet 20 in the left direction in the figure due to the difference in area, so that the poppet 20 is brought into close contact with the seat surface inside the sleeve 10.

4, when the hydraulic pressure introduced through the inlet 12 reaches the relief operating pressure set value by the pilot poppet spring 28, the pilot poppet is opened and the hydraulic pressure in the first pressure chamber d is transmitted to the poppet 20 Through the tank flow path inlet 16 and the tank flow path 14 to the hydraulic tank T side.

5, the pilot poppet is opened and the pressure inside the first pressure chamber d is instantaneously lowered to move the poppet 20 to the right. Therefore, the pressurized oil in the inlet 12 is discharged to the outlet 16 To the hydraulic tank (T).

At this time, the relief operation pressure setting is adjusted by changing the elastic holding force of the spring in accordance with the adjustment of the guide 70.

Particularly, when the relief operating pressure according to the present invention is changed, for example, when an optional secondary relief operating pressure is required for an option device suitably exchanged and installed according to the working environment, The elastic force generated between the main piston springs 88 can be controlled by the pilot signal pressure Pi supplied through the pressure control passage 84. [

For example, the pilot pressure oil can be pressurized through the hydraulic connector connected to the pilot port side of the plug adjuster 90 in the relief operating condition described above.

At this time, the pilot pressure acts on the internal flow path 82 of the main piston 80 through the orifice formed inside the plug adjuster 90, and ultimately, the above-mentioned pilot pressure is applied to the pressure control flow path 84 to the inner wall of the third pressure chamber f formed inside the guide 70. [

3, the main piston 80 moves in the rightward direction in the drawing to a predetermined distance range w, and by compressing the main piston spring 88 so that the initial elastic force is reduced, the relief operation The pressure set point is adjusted to a secondary relief operating pressure in the reduced state.

This means that it is possible to adjust the secondary relief pressure required for the option device exchanged according to the working environment.

At this time, the drain port 72 is removed and a drain path 86 is formed in the main piston 80 to connect the second pressure chamber e and the fourth pressure chamber g to the second pressure chamber e, It is possible to prevent external foreign matter or moisture from penetrating through the drain port 72 and to remove the O-ring 89, which is also helpful for cost reduction.

In addition, leakage of oil is prevented by the pressure seal members 29, 69, thereby achieving an energy saving effect.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is not intended to limit the technical spirit and scope of the present invention.

10: Sleeve
12: inlet
14: tank flow
16: Outlet
20: Poppet
28: Poppit spring
29: Pressure seal member
30: Poppet pilot
38: Poppet pilot spring
40: Poppet sheet
50: Piston
58: Piston spring
60: Plug
62: inlet of tank channel
70: Guide
71: first fastening nut
79: pressure seal member
80: main piston
82: Internal flow path
84: Pressure control flow path
86: drain path
88: Main piston spring
89: O ring
90: Plug adapter
91: second fastening nut
d: first pressure chamber
e: second pressure chamber
f: third pressure chamber
g: fourth pressure chamber

Claims (3)

For relief valves for construction heavy equipment,
A first pressure chamber formed in the first pressure chamber and having an inlet through which the high pressure hydraulic oil flows from the hydraulic pump and a tank passage through which the hydraulic oil flowing into the inlet port is drained to the hydraulic tank;
A poppet movably installed in the sleeve for controlling hydraulic fluid flowing from the hydraulic pump to the hydraulic tank;
A poppet spring for elastically supporting the poppet so as to open and close a flow path between the inlet port and the tank flow path;
A poppet pilot for draining the hydraulic oil to the hydraulic tank when a high pressure is generated that exceeds a primary relief operating pressure set in advance in the first pressure chamber;
A poppet pilot spring for elastically supporting the poppet pilot against the direction in which the poppet pilot is opened;
A poppet seat inserted into the sleeve and seating the poppet pilot;
A piston slidingly moved in the poppet by an operating pressure introduced from an oil pressure pump through an inlet port to contact the poppet pilot;
A piston spring for elastically supporting the piston against the poppet sheet;
A plug coupled to the sleeve to form a tank flow passage opening communicating with the tank flow path, and a guide screwed into the plug to control a relief operating pressure occurring in the second pressure chamber;
The pilot signal spring is slidably moved when the pilot signal pressure is supplied from the outside, and the pilot pressure spring is compressed to adjust the relief operating pressure variably. An internal flow path communicated with the pilot signal pressure A main piston provided;
A plug adjuster screwed to the guide to control a relief operating pressure generated in the second pressure chamber and supporting the main piston spring such that the main piston is resiliently biased against the poppet pilot spring;
The main piston is moved in a direction opposite to the elastic force of the main piston spring by the pilot signal pressure so as to communicate with the inner piston of the main piston and the third pressure chamber inside the guide, A pressure control flow path connecting the pilot signal pressure so that a second relief working pressure is formed which is lower than an initial relief working pressure in the chamber;
A first fastening nut coupled to the guide and preventing a relief operating pressure from being changed after setting; And
And a second coupling nut coupled to the plug adjuster and preventing the relief operating pressure from being changed after the setting,
And a drain path is formed in the main piston so that the fourth pressure chamber in which the main piston spring is installed and the second pressure chamber are in communication with each other.
The method according to claim 1,
And a pressure seal member is installed on an outer circumference of the poppet to prevent leakage of the first pressure chamber formed inside the sleeve.
The method according to claim 1,
And a pressure seal member is installed on the outer circumference of the guide to prevent leakage of the second pressure chamber formed in the plug.

Images