Abstract:
This invention involves a type of pneumatic non-load quick dual-speed hydraulic jack, of which, the small of piston ring ( 17 ) of hydraulic pump cylinder integrates with pump body ( 19 ) and external ring of step pump core ( 14 ) to form movable assembly; the middle part of step pump core ( 14 ) is provided with pump core step interface ( 8 ); the step hole on the same axis of pneumatic valve block on special pneumatic valve structure is provided with washer ( 48 ), button ( 49 ), pneumatic valve core ( 45 ), compressed spring ( 68 ) and valve core securing seat ( 46 ). The available effect of this invention is stated as follows: the pump core interface used for conversion of hydraulic speed is characterized by the excellent process and low cost; the pneumatic valve parts specially provided for the jack can replace the hydraulic quick pump structure partially when the high-pressure air source is available. High-pressure air delivered to the oil reservoir of the external sleeve ( 4 ) will press the hydraulic oil into the oil chamber of oil cylinder, and thus facilitate the quick lift of jack piston under light load or empty load.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention involves a type of hoisting tool, especially a type of pneumatic non-load quick dual-speed hydraulic jack. 
       BACKGROUND OF THE INVENTION 
       [0002]    Hydraulic jack is a type of hoisting equipment widely applied to lift of vehicles or heavy goods. Existing hydraulic jack normally adopts the dynamic oil cylinder using single-post pump core and pump body hole to realize the clearance fit, which is characterized by simple structure and low technical cost. However, it is far from being able to satisfy the functional requirement for quick ascending as required by the hydraulic jack under zero or light load. As disclosed by Chinese patent ZL200620075069.1, the dual-speed vertical hydraulic jack, oil sucked by the pump core of hydraulic system of zero load or light load under low pressure can be fully pressed into the working oil chamber; whereas, partial oil is pressed into the upper chamber of the pump cylinder when the system is under high pressure. Partial oil pressed into the chamber of working oil cylinder can drive the piston assembly to hoist the loaded goods stably and quickly under the action of oil of minimal flux. As the structural technique of the pump core and pump body is so complicated, the high fabrication cost would affect the competition power of the product in international market. 
       SUMMARY OF THE INVENTION 
       [0003]    In consideration of the deficiencies of aforesaid comparative technical proposal, this invention aims to put forward a type of dynamic pump of manual operation for hydraulic jack for the purpose of realizing the function of quick pump under low pressure and slow pump under high pressure for hydraulic jack in the form of relatively simple composite pump core. Meanwhile, it is also expected to provide an optional proposal for non-load pneumatic structure: make use of the high-pressure air as the driving force to press the high-pressure air into the oil chamber of the jack, so as to make the chamber of piston cylinder of the jack absorb the hydraulic oil of high flux pressed out from the oil chamber under relatively high pressure, and thus realize the quick lift of piston rod under zero or light load. 
         [0004]    Aforesaid purposes of this invention are realized through the following technical proposal: A type of pneumatic non-load quick hydraulic dual-speed jack, including framework, base, piston rod, oil cylinder, external sleeve, connecting rod, pin, pedal rod, pump core, pump body, seal and oil return valve, has the following features: valve soleplate is fixed to the base; the lower fastness set on the pump body is sealed and fixed to the valve soleplate; the pump body is sealed and fixed to the upper fastness set and lower fastness set respectively; small piston ring on the pump cylinder is integrated with inner hole on the pump body and lower external ring of the step pump core to form movable assembly; the upper end of the fastness set and big external ring of upper fastness set aim to position the compressed spring in accommodation with spring seat; the circlip is used to position the compressed spring; the middle part of step pump core is provided with pump core step interface; a type of pneumatic non-load quick hydraulic dual-speed jack, including pneumatic valve bridge, pneumatic valve block and air source tie-in assembly, has the following features: washer, button, pneumatic valve core, compressed spring and valve core fastness set are provided inside the step hole of pneumatic valve block on the same axis. 
         [0005]    As compared with existing technologies, this invention has the following favorable effects: axes hole of small piston ring of the pump cylinder forms a movable pair with step pump core post section through clearance fit; whereas, the external circle of the small piston ring of the pump cylinder forms a movable pair with pump body hole. Owing to the simple structural design, the pump core step interface used for conversion between quick and slow pump has high reliability, which is characterized by the excellent fabricating technique and low cost. Furthermore, the high-pressure air provided for the pneumatic valve parts of this type of jack can quickly press the hydraulic oil into the chamber of working oil cylinder to realize the quick lift of piston cylinder or rod of the jack under zero or light load, and thus improve the practicability of the product, and enhance its competitive power in the market. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Illumination of attached drawings for empirical examples: 
           [0007]      FIG. 1 : solid diagram for appearance of this invention 
           [0008]      FIG. 2 : general view of local sections of this invention 
           [0009]      FIG. 3 : Planform of this invention 
           [0010]      FIG. 4 : “A-A” cutaway view of this invention as shown in  FIG. 3   
           [0011]      FIG. 5 : “B-B” cutaway view of this invention as shown in  FIG. 3   
           [0012]      FIG. 6 : “C-C” cutaway view of this invention as shown in  FIG. 3   
           [0013]      FIG. 7 : “D-D” cutaway view of this invention as shown in  FIG. 3   
           [0014]      FIG. 8 : “E-E” cutaway view of this invention enlarged in reference to  FIG. 2   
           [0015]      FIG. 9 : “F” local diagram enlarged in reference to  FIG. 2   
           [0016]      FIG. 10 : another working status diagram corresponding to “F” local diagram enlarged in reference to  FIG. 9 , which specially indicates the position of button and pneumatic valve core when the high-pressure air is delivered to the oil chamber 
           [0017]      FIG. 11 : “G” local diagram enlarged in reference to  FIG. 2   
       
    
    
       [0018]    Designations of parts as indicated by the tabs on the attached drawings are stated as follows: 
         [0000]      1  piston rod,  2 . piston cylinder;  3 . oil cylinder;  4 . external sleeve;  5 . framework part;  6 . base;  7 . valve soleplate;  8 . pump core step interface;  9 . connecting rod;  10 . pedal rod;  11 . pin;  12 . pin;  13 . pin;  14 . step pump core;  15 . circlip;  16 . compressed spring seat;  17 . small piston ring on pump cylinder;  18 . compressed spring;  19  pump body,  20  upper fastness set,  21  lower fastness set,  22  seal ring,  23  circlip,  24  seal ring,  25  seal ring,  26  pump chamber,  27  inner end surface of step hole,  28  steel ball of oil pressing unilateral valve,  29  oil way,  30  oil way,  31  oil way,  32  steel ball of oil sucking unilateral valve,  33  oil way,  34  oil way,  35  oil way,  36  oil way,  37  oil return joy stick,  38  positioning sleeve of torsion spring,  39  torsion spring,  40  oil return valve rod,  41  fastness set of oil return valve,  42  valve mandril,  43  steel ball of oil return valve,  44  compressed spring,  45  pneumatic valve core,  46  fastness set of valve core,  47  air chamber,  48  washer,  49  button,  50  muffler,  51  seal,  52  seal,  53  high-pressure air chamber,  54  air way,  55  pneumatic valve block,  56  air source tie-in assembly,  57  high-pressure regulating valve assembly,  58  seal,  59  inner cone face,  60  sealing pad,  61  screw pair,  62  elastic column pin,  63  pneumatic valve bridge,  64  pin positioning block of connecting rod,  65  sealing pad,  66  column slanting plane,  67  working oil chamber of oil cylinder,  68  compressed spring,  69  seal,  70  seal,  71  seal,  72  inner hole,  73  seal,  74  hole axial circlip,  75  flat headed screw,  76  ball bearing,  77  seal. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    Further description of this invention in combination with attached drawings for empirical examples is helpful to the understanding of contents and effect of this technology. However, the empirical example will not impose any limitation on technical proposal of this invention. 
         [0020]    As indicated in attached drawing, framework part  5  is firmly fixed to base  6 ; oil cylinder is welded to base  6 ; upper and lower parts of external sleeve  4  are sealed and welded to oil cylinder  3  and base  6  respectively; piston rod  1  and piston cylinder  2  form a movable assembly through sealing; piston cylinder  2  and oil cylinder  3  form a movable assembly through sealing; pin positioning block of connecting rod  64  is firmly fixed to the valve soleplate  7 ; base  6  is firmly fixed to the valve soleplate  7 , which subjects to the treatment for hydraulic sealing connection at the junction of corresponding oil way; firmly connect the lower fastness set  21  of pump body to the valve soleplate  7  provided with unilateral valve steel ball  32 , oil way  33  and  34  as well as oil pressing unilateral valve steel ball with the help of screw pairs, and provide a sealing pad  65  at the axle of external thread end of the lower fastness set  21  to seal the high-pressure oil between lower fastness set  21  and valve soleplate  7 ; pump body  19  is connected to the lower fastness set  21  with screw pairs with the seal ring  77  used as the axial static seal between them; the small piston ring  17  on the pump cylinder is installed with the seal ring  22  available for dynamic sealing of hole and axis with step pump core  14 ; lower end of the step pump core  14  is provided with axial circlip  23 ; upper fastness set is connected to the upper part of the pump body  19  installed on the small piston ring  17  of the pump cylinder and its fittings with screw pairs, which uses the seal ring  25  as the static seal between the upper external circle of the pump body  19  and upper fastness set  20 ; clearance fit between the big external circle at the upper part of the step pump core  14  and inner hole of the upper fastness set  20  is not sealed, and the upper end of the lower fastness set  21  as well as the big external circle of upper fastness set  20  are used to position the compressed spring  18  in combination with spring seat  16  and circlip  15 ; the pin positioning block  64  of connecting rod is equipped with pin  11  to form revolute pair between the lower part of the connecting rod  9  and pin  11 ; left end of the pedal rod  10  integrates with upper part of connecting rod  9  and pin  12  to form a revolute pair, which makes use of pin  13  to realize revolute connection between the upper part of step pump core  14  and pedal rod  10 ; the oil pressing oil way  29  is crossly equipped with branch oil way installed with high-pressure regulating valve  57  to limit the loaded oil pressure of the hydraulic system; The upper part of the regulating valve  57  is installed with flat headed screw  75 . 
         [0021]    As indicated in attached drawing  6 , compressed spring  44  is installed under the steel ball  43  of the oil return valve in the discharge oil way of valve soleplate  7 ; whereas, the upper part of the steel ball  43  is installed with a valve mandril  42  constituting hole and axis moving pair with valve soleplate  7 ; an inner screw hole is provided at the upper part of the valve mandril  42 , which forms screw pair  61  with external screw of oil return valve fastness set; axle face of external screw end of fastness set  41  of oil return valve as well as the sealing pad  60  and upper face of valve soleplate  7  are sealed via tightening screw pair; oil return valve rod  40  and fastness set  41  form a dynamic sealing revolute pair; after the axle and hole fit with positioning sleeve  38  of torsion spring, the upper part of the valve rod  40  is firmly connected with elastic post pin  62  to facilitate the firm connection between the upper part of valve rod  40  and oil return joy stick; a ball bearing  76  is installed between the inner hole face of the fastness set  41  of oil return valve rod and moving face of valve rod  40 ; the lower part of the oil return valve rod is provided with a column slanting plane  66  which is in sliding contact with valve mandril  42 . Furthermore, a torsion spring  39  is installed between the positioning sleeve  38  of torsion spring and fastness set  41  of oil return valve; both ends of the torsion spring  39  are firmly fixed to the positioning sleeve  38  and fastness set  41  respectively. 
         [0022]    According empirical example as indicated in  FIGS. 8 ,  9  and  10 , the left side of pneumatic valve bridge  63  is welded to external sleeve  4  with the right side in sealed connection with pneumatic valve block  55  via seal  69 ; air way  54  on the pneumatic valve block  55  is connected with oil chamber inside the external sleeve  4 ; whereas, the high-pressure air chamber  53  is connected with air source tie-in assembly  56 ; pneumatic valve core  45  and relevant parts are provided with seal  51 ,  52 ,  58  and  70  used for dynamic sealing as well as seal  71  used as static seal; pneumatic valve block  55  constitute hole and axle seal with column washer  48  for axial positioning; at normal state, the seal  52  on the pneumatic valve core  45  acts on the inner cone sealed face  59  of the pneumatic valve block  55  under the pressure imposed by the compressed spring  68  to realize the combined sealing, and separate the high-pressure air chamber  53  from air way  54 . Air way  47  installed on the pneumatic valve block  55  in connection with air way  54  is connected to muffler  50 ; fastness set  46  of valve core is connected to the pneumatic valve block  55  and seal  73  via screw pair through static sealing, of which, the axial hole forms dynamic sealed moving pair with left end of pneumatic valve core  45  with the right end face used to position the left end of the compressed spring; the middle part of the pneumatic valve block  55  is provided with an inner hole  72  which can form dynamic sealed moving pair with upper seal  51  on the pneumatic valve core; right end section of pneumatic valve core  45  is firmly fixed to button  49 ; whereas, external circle of left end of button  49  forms dynamic sealed moving pair with integrated seal  70  for penetrating hole of washer  48 ; the hole groove of pneumatic valve block on the right end of washer  48  is provided with hole axial circlip  74 . 
         [0023]    Operating procedures of empirical example for this invention are stated as follows: firstly, place the upper top of jack piston rod  1  under the object to be propped up; Under the action of torsion spring  39 , the normal position of oil return valve rod  40  can ensure the highest position of oil return valve mandril in structural space; in other words, the steel ball  43  of oil return valve is thoroughly enclosed in the upper valve seat under the action of compressed spring  44 . When the pedal rod  10  is pressed by the operator, moving mechanism would drive the step pump core  14  to move to the lower position under the combined action of connecting rod  9 , pin  11 ,  12 , and  13 ; when the pump core step interface  8  move downwards to contact with upper end of small piston ring  17 ; meanwhile, the pressure imposed on the step pump core  14  would make the small piston ring  17  of pump cylinder move downwards to the lower end of small piston ring  17  to connect with inner face of step hole; when the step pump core  14  and small piston ring of pump cylinder  17  are pressed, the hydraulic oil inside the pump chamber  26  would pressed into the working oil chamber  67  via the steel ball  28  of oil pressing unilateral valve, oil way  29 ,  30  and  31 ; the process of combined displacement of this step pump core  14  and small piston ring  17  of pump cylinder aims to supply oil at high flux for the purpose of facilitating the quick lift of piston rod  1  and piston cylinder  2 ; when the pressure imposed on the pedal rod  10  is released, the step pump core  14  would quickly move upwards for reverse displacement under the rebound force imposed by the compressed spring  18  to contact with the lower end of small piston ring  17  of pump cylinder at circlip  23  for the purpose of drawing the small piston ring  17  back to the highest position in the pump chamber  26 . The process of combined displacement of step pump core  14  and small piston ring  17  of pump cylinder moving upwards aims to produce negative pressure inside the pump chamber  26 ; the hydraulic oil inside the external sleeve  4  would be pressed into the pump chamber  26  under the action of atmosphere via the oil way  34  and  33  to complete the oil absorption at high flux; when the load imposed on the jack reaches the specific value, pressure inside the oil pressing system would prop up the small piston ring  17 ; when the pedal rod  10  is pressed or released at this point, the relative displacement is only available between the lower external circle of step pump core  14  and inner hole of small piston ring  17 , which enables the jack to press and absorb oil in circulation for the purpose of realizing the automatic conversion of hydraulic dual-speed pump through pressing. 
         [0024]    In the hydraulic system of this empirical example, when the loaded oil pressure exceeds the pressure regulating value of high-pressure valve assembly  57 , the hydraulic oil pressed out from the pump chamber  26  would automatically prop up and open the steel ball of unilateral valve of high-pressure regulating valve assembly  57  to enable the oil return to the oil chamber of external sleeve  4  via the oil way  35 ,  36 ,  33  and  34  to realize the automatic overload protection of the system. 
         [0025]    Operating procedures of this pneumatic non-load quick lifting structure as indicated by this empirical example are stated as follows: firstly, deliver the high-pressure air to the high-pressure air chamber  53  of pneumatic valve block  55  via the air source tie-in assembly  56 , and then press the button  49  to the left side to enable the pneumatic valve block to overcome the resistance imposed by the compressed spring  68  to move to the left side for the purpose of making seal  52  move away from the inner cone face  59  to facilitate the seal  51  to come into the inner hole  72  for dynamic sealing. At this point, air source inside the high-pressure air chamber  52  would be pressed into the upper position of oil inside the external sleeve  4  to maximize the air pressure inside the oil chamber quickly for the purpose of pressing the hydraulic oil into the working oil chamber  67  of oil cylinder via the oil way  34 ,  33 ,  32 ,  26 ,  28 ,  29 , and  31 ; when the button  49  is released, the force imposed by the compressed spring  68  would make the pneumatic valve core  45  move to the left side, and the seal  52  would contact with inner cone face  59  for sealing to suspend the further delivery of high-pressure air into the air way  54 ; meanwhile, the high-pressure air inside the oil chamber of external sleeve  4  would discharge air to the air chamber  47  and muffler  50  to keep balance with atmosphere. 
         [0026]    Once the lifting load process of the jack is completed, it is only need to overcome the force imposed by the torsion spring to turn the lowest point on the column slanting face  66  on the lower end of oil return joy stick  37  to the top junction of valve mandril  42  for the purpose of making steel ball  43  of oil return valve move away from the valve seat by overcoming the pressure imposed by the compressed spring  44  under the pressure imposed by the valve mandril  42 ; at this point, the high-pressure oil inside the working chamber  67  of oil cylinder would return to the oil chamber inside the external sleeve  4  via the oil way  31 , steel ball of oil return valve, oil way  36  and  34  respectively.