Patent Publication Number: US-7717649-B2

Title: Suspending hydraulic pillar

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
   This application claims priority to and the benefit of China Patent Application No. 200510095108.4, filed on Oct. 31, 2005, and PCT Patent Application No. PCT/CN2005/002422, filed on Dec. 31, 2005, both of which were filed in the China Patent and Trademark Office. 
   FIELD OF THE INVENTION 
   The present invention relates to a suspending hydraulic pillar, which is particularly suitable for support of underground mining face, and is also applicable to other occasions in need of support. 
   BACKGROUND OF THE INVENTION 
   Support of underground mining face is one of indispensable equipments in mining. The support equipment adopted in China includes various forms, such as wooden pillar, single frictional metal pillar, single hydraulic pillar, and dual-extension hydraulic pillar, etc. In recent years, owning to continuous research and practice effort of the engineers, the support technique gains significant development; the wooden pillar is rarely adopted; the single fractional metal pillar is also rarely used due to its poor and uniform setting load and uncertain constant increasing resistance lowering distance; the single hydraulic pillar is a new product developed after the single fractional metal pillar, and has been applied for more than 30 years. The single hydraulic pillar is provided with three-way valve, and hydraulic fluid supplied by emulsion station preset by working face is injected into oil cylinder of pillar via the three-way valve for initial support; when pressure is applied to the top plate and released, the emulsion is then discharged via the three-way valve, and the pillar is lowered; the hydraulic fluid from the emulsion station is reused in repeat work for initial support. The application of the single hydraulic pillar brings great convenience for the mining face, but issues as below still exist: 1) arc welding seam is provided on movable prop, which leads to lowered mechanical strength of the movable prop; when pressure is applied on the top plate, the welding seam is prone to fracture and crack, which is a potential safety hazard; 2) after wearing of the cylinder inner surface which is high pressure sealed surface, inner leakage of the pillar may occur, which is a potential safety hazard for mining workers; 3) the emulsion quality is not guaranteed due to poor underground water quality in coal mine, which leads to severe corrosion to the cylinder and the pillar failure; the quantity of failed pillars is about 300,000 each year, which is a dramatic waste. Now most coal mines adopt single hydraulic pillar, the demand for single hydraulic pillar is over 2,000,000 each year, therefore it is very important to further modify and improve the single support equipment. 
   SUMMARY OF THE INVENTION 
   As the available techniques have aforementioned disadvantages, the object of the present invention is to provide a suspending hydraulic pillar which has improved structure, low vulnerability to stuck, low cost, high strength, good application effect, and long service life. 
   The inventive suspending hydraulic pillar comprises a top cover and a movable prop, a sealing cover is arranged in the movable prop, the movable prop is arranged in an oil cylinder; a handle-valve body is arranged between the oil cylinder port and the movable prop; a reset spring is connected with the sealing cover; an oil inlet is arranged on the movable prop; a three-way valve is arranged in the handle-valve body; a dust-prevention ring, a seal ring, and a connecting steel wire are arranged between the handle-valve body and the movable prop and the oil cylinder; and an oil inlet is provided for connecting the oil cylinder and the three-way valve; a seal ring and a connecting steel wire are arranged between the cylinder bottom seat and the oil cylinder; a gasket is arranged below the sealing cover in the movable prop, the gasket is provided with several through holes; outer ring of the gasket is disposed against the shoulder of the movable prop inner diameter; the movable prop outer diameter is provided with a position-limiting steel wire and a guiding ring which are fitted on the groove of the movable prop outer diameter; a guiding ring is provided between the handle-valve body and the movable prop; all the sealing rings are provided with retaining rings therein; the outer cylinder radial direction of the sealing cover is provided with through hole matching drilling with the top cover and the movable pillar, and an elastic cylindrical pin is arranged in the through hole. 
   The inventive suspending hydraulic pillar has said sealing cover lower end face in shape of plane or cone flat bottom. The sealing cover with lower end face in shape of cone flat bottom is provided with a connecting steel wire at jointing face between the top cover and the movable prop. 
   The inventive suspending hydraulic pillar comprises a top cover, a movable prop, and an oil cylinder cooperating with the movable prop; a handle-valve body arranged between an oil cylinder port and a movable prop, a reset spring, an oil inlet on the movable prop; a three-way valve arranged in the handle-valve body; a dust-preventing ring, a sealing ring, and a connecting steel wire provided between the handle-valve body and the movable prop and the oil cylinder; an oil inlet for communicating the oil cylinder and the three-way valve; a sealing ring and a connecting steel wire arranged between the cylinder bottom seat and the cylinder; an upper hanging ring arranged in the movable prop, connected with the reset spring, and directly welded on inner wall of the top cover; a sealing ring and a connecting steel wire arranged between the top cover and the movable prop fitting face; a position-limiting steel wire and a guide ring arranged on outer diameter of the movable prop which are fit on groove of the movable prop outer diameter; a guiding ring arranged between the handle-valve body and the prop; and retaining rings arranged in all the sealing rings. 
   The inventive suspending hydraulic pillar is particularly suitable for support of underground mining face. It mainly comprises oil cylinder, movable piston, handle-valve body, reset spring, top cover, bottom seat, and three-way valve. The handle-valve is arranged between the oil cylinder port and the movable prop, and position-limiting steel wire and guide ring are arranged at lower part of the outer diameter of the movable prop with an oil inlet. The arc base and movably connected pin are arranged on the top cover; the three-way vale is mounted on the handle-valve body; the dust-preventing ring and sealing member are provided between the handle-valve body and the movable prop and the oil cylinder, and provided with connecting steel wire for fixing them on the oil cylinder; the handle-valve body does not move up or down along with telescopic extension/contraction of the movable prop; the sealing cover is optionally arranged in the movable prop. The gasket with through holes is arranged in the movable prop with the sealing cover, and the reset spring is connected with the sealing cover. In the movable prop without the sealing cover, the reset spring and the top cover are connected. The invention can ensure strength of the movable prop, reduce weight of the pillar, and also reduce wearing caused by relative movement between the movable prop, cylinder prop and the cylinder; which effectively avoids stuck of the movable prop, is convenient and safe for operator, reduces labor intensity, and protects the three-way valve from damage in use. In dismounting, the top cover can be taken off without damaging other relevant parts only by dismounting the elastic cylindrical pin. The invention has the advantage of compact and reasonable structure, good stability, high strength of movable prop, high bearing capability, long and reliable work stroke, light weight of pillar, good sealing, good corrosion resistance, convenient mounting/dismounting, convenient use, long service life, low cost, good effect, and wide practicability. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is the section view of structure in embodiment 1. 
       FIG. 2  is the section view of structure in embodiment 2. 
       FIG. 3  is the section view of structure in embodiment 3. 
       FIG. 4  is the section view of structure in embodiment 4. 
     
       
         
           
               
             
               
                   
               
               
                 Symbols 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 1 
                 top cover 
               
               
                 2 
                 sealing cover 
               
               
                 3 
                 movable prop 
               
               
                 4 
                 handle valve body 
               
               
                 5 
                 oil cylinder 
               
               
                 6 
                 position-limiting steel wire 
               
               
                 7 
                 reset spring 
               
               
                 8 
                 oil inlet 
               
               
                 9 
                 bottom seat 
               
               
                 10  
                 pin 
               
               
                 11  
                 arc base 
               
               
                 12  
                 elastic cylindrical pin 
               
               
                 13, 18, 20, 24, 29 
                 sealing ring 
               
               
                 14, 19, 21, 25, 30 
                 retaining ring 
               
               
                 15  
                 dust-preventing ring 
               
               
                 16  
                 gasket 
               
               
                 17, 26 
                 guiding ring 
               
               
                 27  
                 three-way valve 
               
               
                 22, 23, 28 
                 connecting steel wire 
               
               
                   
               
            
           
         
       
     
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   The present invention will be further described with reference to the accompanying drawings: 
   Embodiment 1 
   As illustrated in  FIG. 1 , it mainly comprises top cover  1 , sealing cover  2 , movable prop  3 , handle-valve body  4 , oil cylinder  5 , reset spring  7 , and sealing members at each connection part. The top cover  1  is provided with arc base  11  rotatable along arbitrary directions and movably connected pin  10 . The arc base  11  is arranged in groove of the top cover  1  square plate central part, center of the groove is provided with the pin  10  through the top cover  1  and making the arc base  11  and the top cover  1  be movably connected, tail of the pin  10  is fixed on a gasket by welding, and the pin  10  can move in the hole. Y-shaped sealing ring  13  and retaining ring  14  are provided between the sealing cover  2  and the movable prop  3 , the sealing cover  2  is provided with gasket  16  at lower part, outer ring of the gasket  16  is against the shoulder of the movable prop  3  inner diameter, and multiple through holes are opened on the gasket  16  according to diameter thereof. The sealing cover  2  has a lower end face in planar shape, an upper end in bowl shape, the outer cylinder radial direction of the sealing cover ( 2 ) is provided with through hole matching drilling with the top cover ( 1 ) and the movable pillar ( 3 ); and elastic cylindrical pin  12  slightly movable along axial direction of the sealing cover  2  is arranged in the through hole. The movable prop  3  is arranged in the oil cylinder  5 , the handle-valve body  4  is arranged between the cylinder  5  top and the movable prop  3 . Dust-preventing ring  15 , guiding ring  17 , Y-shaped sealing ring  18 , and retaining ring  19  are sequentially mounted between the handle-valve body  4  and the movable prop  3  fitting face. Y-shaped sealing ring  20 , the retaining ring  21 , and the connecting steel wire  22  for fixing the handle-valve body  4  are disposed between the handle-valve body  4  and the oil cylinder  5 . Lower hook of reset spring  7  arranged in the movable prop  3  is arranged in hanging ring welded on the cylinder base seat  9 , and the upper hook is disposed in hanging ring welded on the sealing cover  2  lower end. Outer cylindrical face of the movable prop  3  lower part is provided with position-limiting steel wire  6  and guide ring  26  which are fit in groove of the movable prop  3  outer cylindrical face. The handle-valve body  4  is provided with three-way valve  27 , and oil inlet connecting the cylinder  5  and the three-way valve. The lower part cylinder of the movable prop  3  has multiple oil inlets  8  communicating with oil path of the oil cylinder  5 . Y-shaped sealing ring  24  and the retaining ring  25  are disposed between the oil cylinder bottom seat  9  and the oil cylinder  5 , which are closely jointed via the connecting steel wire  23 . 
   Embodiment 2 
   As shown in  FIG. 2 , it is substantially the same as the embodiment 1, the only difference is in that the lower end face of the sealing cover  2  is cone flat bottom, the sealing cover  2  upper end face is opened with blind hole, only Y-shaped sealing ring  13  and gasket  14  are fitted between the sealing cover  2  and the movable prop  3  fitting face, and the top cover  1  is directly fixed with the movable prop  3  via connecting steel wire  28 . 
   Embodiment 3 
   As shown in  FIG. 3 , it is substantially the same as the embodiment 2, the only difference is in that the top of the top cover  1  is a flat plane, without arc base  11  rotatable along arbitrary direction and movably connected pin  10 . 
   Embodiment 4 
   As shown in  FIG. 4 , it mainly comprises top cover  1 , movable prop  3 , handle-valve body  4 , oil cylinder  5 , reset spring  7 . The movable prop  3  is arranged in the oil cylinder  5 , the handle-valve body  4  with three-way valve  27  is arranged between the oil cylinder port and the movable prop  3 . Dust-preventing ring  15 , guiding ring  17 , Y-shaped sealing ring  18 , and retaining ring  19  are sequentially mounted between the handle-valve body  4  and the movable prop  3 . Y-shaped sealing ring  20  and the retaining ring  21  are disposed between the handle-valve body  4  and the oil cylinder  5 , and the handle-valve body  4  are fixed on the cylinder  5  via the connecting steel wire  22 . Oil inlet for communicating the oil cylinder  5  and the three-way valve is arranged on the handle-valve body  4 . When the movable prop  3  moves up and down, the handle-valve body does not move along with it. Upper hanging ring connected with the reset spring  7  in the movable prop  3  is directly welded on inner wall of the top cover  1 ; lower hook of reset spring  7  is arranged in hanging ring welded on the cylinder base seat  9 , and the upper hook is disposed in hanging ring in the top cover  1 . Sealing ring  29 , retaining ring  30 , and connecting steel wire  28  for fixing are provided between the top cover  1  and the movable prop  3  fitting face. Outer diameter of the movable prop  3  is provided with position-limiting steel wire  6  and guide ring  26  which are fit in groove of the movable prop  3  outer diameter. Guide ring  17  is provided between the handle-valve body  4  and the movable prop  3 . The lower part cylinder of the movable prop  3  has multiple oil inlets  8  communicating with oil path of the oil cylinder  5 . Y-shaped sealing ring  24  and the retaining ring  25  are disposed between the bottom seat  9  and the oil cylinder  5 , which are closely jointed via the connecting steel wire  23 . 
   In application, oil is injected to pillar via three-way valve  27 , the oil enters into annular cavity formed by the oil cylinder  5  and the movable prop  3  via through hole on the handle-valve body, and enters into the movable prop cavity via the through hole  8  of the movable prop  3  lower part, hence along with injection of the oil, when certain pressure is reached, the movable prop  3 , the top cover  1 , and the sealing cover  2  rise to a certain height for pillar support; when the pillar is lowered, under the action of reset spring, oil is discharged to annular cavity between the movable prop  3  and the oil cylinder  5  via radial through holes  8  at the movable prop  3  lower end, and is drained via the through hole on the handle-valve body  4  and the three-way valve thereon. The pillar is lifted and lowered once for each injection and drainage to finish one working cycle.