1. The utility model provides a hydraulic support stand prevents valve that rises stifled which characterized in that: the high-flow-rate valve comprises a valve body, a high-flow-rate valve core, a small-flow-rate valve core, a strong spring and a weak spring, wherein a liquid inlet flow channel and a pressure relief cavity are formed in the valve body, the front end of the pressure relief cavity is communicated with a liquid outlet of the liquid inlet flow channel, a plug is arranged at the rear end of the pressure relief cavity, the pressure relief cavity is communicated with the outside through a liquid outlet on the side face, the high-flow-rate valve core is plugged at a liquid outlet of the liquid inlet flow channel, two ends of the strong spring are respectively connected with the plug and the large-flow-rate valve core, a thin flow channel is formed in the central shaft of the high-flow-rate valve core in a penetrating mode, the small-flow-rate valve core.

2. The hydraulic support column expansion valve block as claimed in claim 1, wherein: the large-flow valve core and the liquid outlet of the liquid inlet flow channel and the small-flow valve core and the liquid outlet of the thin flow channel are butted by conical contact surfaces.

3. The hydraulic support column expansion valve block as claimed in claim 1 or 2, wherein: the rear end of the large-flow valve core is provided with a thick-diameter positioning column corresponding to the front end of the strong spring, the plug is provided with a positioning groove corresponding to the rear end of the strong spring, and the rear end of the strong spring is clamped inside the positioning groove.

4. The hydraulic support column expansion valve block as claimed in claim 3, wherein: and the rear end of the small-flow valve core and the center of the plug are respectively provided with small-diameter positioning columns corresponding to two ends of the weak force spring.

Background

The hydraulic support is a support piece frequently used in underground coal mine mining, the upright column is a key part in the hydraulic support, the telescopic action is realized through the liquid inlet and outlet of an external liquid supply pipeline, an operating valve is arranged on the liquid supply pipeline, and due to the fact that pulverized coal under the mine or other impurities in working liquid are easily gathered on the operating valve, the phenomenon that the operating valve is blocked instantly when the operating valve returns liquid is often caused in the using process, the liquid return on the upper cavity of the upright column is not smooth, the pressure of the upper cavity is rapidly increased, the pressure of the lower cavity can reach several times or even dozens of times, the upper cavity expands a cylinder, and the upper cavity can not be used and can only be discarded.

In addition, when the operating valve is blocked, generally, the blocking impurities can be automatically flushed away after the working fluid flows through for a period of time, normal use cannot be influenced, but the working fluid cannot completely flush the blocking, so that later-stage blocking is continuously aggravated until the blocking is completely damaged, and an effective method for detecting the blocking condition of the operating valve is not available at present. This causes a situation in which the upper chamber of the column is damaged by the expansion cylinder once the operating valve is completely blocked, resulting in a large loss.

In order to solve the above problems, people are always seeking an ideal technical solution.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides the hydraulic support upright post expansion-proof valve block which is scientific in design, timely in pressure relief, capable of prolonging the service life of an upright post and capable of being used for evaluating the blocking condition of an operating valve.

In order to achieve the purpose, the invention adopts the technical scheme that: a hydraulic support stand column expansion valve plug comprises a valve body, a large-flow valve core, a small-flow valve core, a strong spring and a weak spring, wherein a liquid inlet flow channel and a pressure relief cavity are formed in the valve body, the front end of the pressure relief cavity is communicated with a liquid outlet of the liquid inlet flow channel, a plug is arranged at the rear end of the pressure relief cavity, the pressure relief cavity is communicated with the outside through a liquid discharge hole in the side face, the large-flow valve core is plugged at a liquid outlet of the liquid inlet flow channel, two ends of the strong spring are respectively connected with the plug and the large-flow valve core, a thin flow channel is formed in the center shaft of the large-flow valve core in a penetrating mode, the small-flow valve core is plugged at the liquid outlet of the thin flow channel, and two ends of the weak spring are.

Based on the above, conical contact surfaces are adopted for butt joint between the large-flow valve core and the liquid outlet of the liquid inlet flow channel and between the small-flow valve core and the liquid outlet of the thin flow channel.

Based on the above, the rear end of the large-flow valve core is provided with a large-diameter positioning column corresponding to the front end of the strong spring, the plug is provided with a positioning groove corresponding to the rear end of the strong spring, and the rear end of the strong spring is clamped inside the positioning groove.

Based on the above, the rear end of the small-flow valve core and the center of the plug are respectively provided with small-diameter positioning columns corresponding to the two ends of the weak force spring.

Compared with the prior art, the small-flow valve core and the large-flow valve core form a two-stage pressure relief mechanism, the small-flow valve core is provided with restoring force by the weak spring, the large-flow valve core is provided with restoring force by the strong spring, when the pressure in the upper cavity of the upright post rises in a small amplitude, the small-flow valve core is independently opened for pressure relief, the reaction is timely, the pressure relief flow can be controlled in a small range, when the pressure in the upper cavity of the upright post rises in a large amplitude, the small-flow valve core and the large-flow valve core can be simultaneously opened, the pressure relief flow is increased, and therefore the cylinder rising condition in the upper cavity of the upright post is avoided; compared with a single-stage pressure relief mode, the invention can start small-flow pressure relief when the pressure is very small, the pressure continues to rise, and then start large-flow pressure relief, thereby avoiding cylinder expansion caused by that the single-stage pressure relief is not as long as the working fluid is led outwards, and greatly improving the system stability; in addition, according to the opening conditions of the small-flow valve core and the large-flow valve core after the operation valve is opened every time, the plugging condition of the operation valve can be judged, the operation valve is evaluated in advance, the operation valve is maintained or replaced in time, and larger loss is avoided; the pressure relief device has the advantages of scientific design, timely pressure relief, capability of prolonging the service life of the upright post and capability of being used for evaluating the blocking condition of the control valve.

Furthermore, the return directions of the small-flow valve core and the large-flow valve core are conveniently guided by adopting a mode of butt joint of conical contact surfaces, so that the small-flow valve core and the large-flow valve core can automatically return to a central position, and the situations of displacement and untight plugging of the valve cores are avoided; the two ends of the strong spring are fixed by the large-diameter positioning column and the positioning groove, so that the strong spring is prevented from being separated from the telescopic track; the two small-diameter positioning columns ensure that two ends of the weak force spring are not separated from the small-flow valve core and the plug.

Drawings

Fig. 1 is a schematic structural diagram of an anti-expansion valve plug of a hydraulic support column.

In the figure: 1. a valve body; 2. a liquid inlet flow channel; 3. a pressure relief cavity; 4. plugging by screwing; 5. a drain hole; 6. a high-flow valve core; 7. a strong spring; 8. a small flow valve core; 9. a weak force spring; 10. a thin flow channel; 11. a small-diameter positioning column; 12. a coarse diameter positioning column; 13. and (6) positioning a groove.

Detailed Description

The technical solution of the present invention is further described in detail by the following embodiments.

As shown in figure 1, the anti-expansion valve plug of the hydraulic support upright column comprises a valve body 1, a large-flow valve core 6, a small-flow valve core 8, a strong spring 7 and a weak spring 9, a liquid inlet flow channel 2 and a pressure relief cavity 3 are arranged in the valve body 1, the front end of the pressure relief cavity 3 is communicated with a liquid outlet of the liquid inlet flow channel 2, the rear end of the pressure relief cavity 3 is provided with a plug 4, the pressure relief cavity 3 is communicated with the outside through a liquid discharge hole 5 on the side surface, the large-flow valve core 6 is blocked at the liquid outlet of the liquid inlet flow channel 2, two ends of the strong spring 7 are respectively connected with the plug 4 and the large-flow valve core 6, a thin flow channel 10 is arranged at the central shaft of the large-flow valve core 6 in a penetrating way, therefore, two ends of the thin flow passage 10 are respectively communicated with the liquid inlet flow passage 2 and the pressure relief cavity 3, the small flow valve core 8 is blocked at the liquid outlet of the thin flow passage 10, and two ends of the weak force spring 9 are respectively connected with the plug 4 and the small flow valve core 8.

The working principle is as follows:

the expansion-proof valve plug is arranged on an upper cavity of a vertical column of a hydraulic support, a liquid inlet channel 2 is communicated with an upper cavity channel, a large-flow valve core 6 and a small-flow valve core 8 form a two-stage pressure relief mechanism, a weak spring 9 provides restoring force for the small-flow valve core 8, a strong spring 7 provides restoring force for the large-flow valve core 6, when the pressure of the upper cavity of the vertical column rises in a small amplitude, for example, when the pressure reaches 20 MPa, the elastic force of the weak spring 9 can only be overcome, the small-flow valve core 8 is independently opened for pressure relief, the reaction is timely, the pressure relief flow can also be controlled in a small range, when the pressure of the upper cavity of the vertical column rises greatly, for example, 40 MPa is reached, the elastic forces of the strong spring 7 and the weak spring 9 are overcome, and the large-flow valve core 8 and the large-flow valve core 6 can be simultaneously opened for pressure relief flow, so that the cylinder expansion condition of the upper cavity of the vertical column is avoided.

In order to ensure that the valve core does not clamp and shift in the opening and closing process, conical contact surfaces are adopted for butt joint between the large-flow valve core 6 and the liquid outlet of the liquid inlet flow channel 2 and between the small-flow valve core 8 and the liquid outlet of the thin flow channel 10; when the valve core is used, the conical contact surface is convenient for guiding the return directions of the small-flow valve core 8 and the large-flow valve core 6, so that the valve core can automatically return to the central position, and the situations of valve core displacement and untight plugging are avoided.

In order to avoid derailment in the process of extension and retraction of the strong spring 7 or the weak spring 9, a large-diameter positioning column 12 is arranged at the rear end of the large-flow valve core 6 corresponding to the front end of the strong spring 7, a positioning groove 13 is arranged at the rear end of the plug 4 corresponding to the strong spring 7, the front end of the strong spring 7 is sleeved outside the large-diameter positioning column 12, and the rear end of the strong spring 7 is clamped inside the positioning groove 13; the rear end of the small-flow valve core 8 and the center of the plug 4 are respectively provided with a small-diameter positioning column 11 corresponding to the two ends of the weak force spring 9, and the end part of the weak force spring 9 is sleeved outside the small-diameter positioning column 11.

When the pressure relief valve is used specifically, when the pressure of the upper cavity is very low, the small-flow valve core 8 can be opened to relieve the pressure, the pressure is continuously increased, and then the large-flow valve core 6 is opened, so that the phenomenon of cylinder expansion caused by the fact that single-stage pressure relief can only be opened when the pressure is higher and working liquid cannot be drained out in time can be avoided, and the stability of the system is greatly improved; in addition, the condition of the operating valve can be evaluated according to the opening conditions of the large-flow valve core 6 and the small-flow valve core 8 when the operating valve is opened every time, specifically, for example, when the operating valve is opened for the first times, the small-flow valve core 8 is opened, and when the operating valve is opened for the second times, the large-flow valve core 6 is also opened, which indicates that the plugging of the operating valve is not completely flushed and is more and more serious, and the operating valve should be maintained or replaced in time at this time; for example, when the valve is opened for several times, the small-flow valve element 8 and the large-flow valve element 6 are opened irregularly, or the small-flow valve element and the large-flow valve element 6 are not opened at times, which indicates that impurities are completely flushed away by the working fluid after the operating valve is opened for a period of time, and the operating valve belongs to a normal working state.

Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the same; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.