Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B5/00—Machines or pumps with differential-surface pistons
  • F04B5/02—Machines or pumps with differential-surface pistons with double-acting pistons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/08—Regulating by delivery pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/10—Valves; Arrangement of valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/14—Pistons, piston-rods or piston-rod connections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
  • F04B9/14—Pumps characterised by muscle-power operation

Definitions

• the invention belongs to the technical field of machinery and relates to a plunger pump, in particular to a variable displacement plunger pump. Background technique
• Plunger pumps for low-pressure, high-flow, high-pressure, low-flow, liquid-delivery are widely used in hydraulic tools, hydraulic handling equipment, and lifting equipment.
• the purpose of setting the plunger pump is to improve the pumping efficiency and high pressure of the plunger pump at low pressure.
• Taiwan Patent Office TW401484 provides a "piston pump” which includes a pump body having a slidable plunger in the pump body, the plunger separating the interior of the pump body into two chambers adjacent to each other:
• the upper cavity and the lower cavity have an oil inlet hole communicating with the lower cavity and an oil outlet communicating with the upper cavity, and the oil inlet hole and the oil outlet hole are respectively provided with a flow direction consistent with the oil flow direction To the valve.
• a check valve is also provided on the plunger.
• a spring is disposed in the lower cavity, and the plunger has a tendency to move upward toward the cavity under the action of the spring.
• the high pressure plunger at the upper chamber presses the low pressure plunger, and the low pressure plunger opens over the spring force during the downward movement of the spring force, and the oil at the lower chamber enters through the overflow valve.
• the upper chamber is then discharged by the upper chamber.
• the low pressure plunger is reset by the spring force of the spring.
• the one-way valve at the oil inlet opens and the oil enters the lower chamber; at the same time, the upper chamber is enlarged. The oil opens the check valve at the oil outlet, and the oil is discharged through the oil outlet.
• the reciprocating action described above allows the oil to be continuously discharged from the oil outlet.
• the oil of the lower chamber enters the upper chamber through the overflow valve when the low pressure plunger moves downward, the plunger is discharged from the oil outlet hole at the upper chamber during the upward movement.
• the amount of pump oil is large during the plunger moving up; the amount of pump oil is less during the plunger pressing process.
• the handle is released, the hydraulic cylinder piston protrudes more, the hydraulic pressure when the handle is pressed The phenomenon that the cylinder protrudes less, which causes the oil to be unbalanced during the low pressure operation, and then suddenly and slowly.
• Chinese Patent Publication No. CN102080641A provides a "reciprocating plunger pump oil supply device" which includes a pump body having a piston and a piston separating the pump body into two independent chambers: a left chamber and a right chamber body.
• the pump body has an oil inlet hole and an oil outlet hole communicating with the left cavity body, and an oil inlet hole 2 and an oil outlet hole 2 communicating with the right cavity body on the pump body.
• the piston is driven by gears and racks. When the piston moves left and right, the oil outlet hole and the oil outlet hole can continue to flow out.
• the above device suddenly fails to discharge oil.
• An object of the present invention is to provide a variable displacement plunger pump which is simple in structure and can quickly realize oil discharge in view of the above problems in the prior art.
• a variable displacement piston pump comprising a pump body having a cavity inside, a low pressure plunger and a high pressure plunger, wherein the low pressure plunger is disposed in the pump body and
• the upper low pressure plunger can divide the interior of the pump body into two independent cavities: an upper cavity and a lower cavity, wherein the lower cavity is provided with a spring and the two ends of the spring respectively act on the low pressure plunger
• the high pressure plunger passes through the pump body and the inner end thereof is located in the upper cavity, and the outer end thereof protrudes out of the pump body, wherein the low pressure plunger is arranged
• the pump body has an oil inlet hole and an oil outlet hole communicating with the upper cavity body
• the pump body further has an oil inlet hole 2 and an oil outlet hole 2 communicating with the lower cavity body
• the oil inlet hole 1, the oil inlet hole 2, the oil outlet hole 1 and the oil outlet hole are respectively provided with an oil inlet check valve
• the applied external force drives the high pressure plunger to move up and down during the low pressure state.
• the oil hole one and the oil outlet hole can be continuously separated from each other; in the high pressure state, only the oil outlet hole can be separated from the oil, and the oil discharge amount of the oil outlet hole 2 at this time is small relative to the low pressure state.
• the overflow mechanism In the low pressure state, when the high pressure plunger moves up, the low pressure plunger moves up under the action of the spring force.
• the overflow mechanism is closed, the oil inlet check valve is opened, and the oil discharge check valve is opened.
• the overflow mechanism is closed, the oil inlet check valve is opened, and the oil discharge check valve is opened. The oil enters the upper chamber through the oil inlet hole, and the oil in the lower chamber is discharged through the oil outlet hole. .
• the low pressure plunger moves up under the spring force of the spring. Due to the high oil pressure at the upper chamber, the low pressure plunger cannot be fully moved with the high pressure plunger. Contact. During this process, the relief valve is closed, the oil inlet check valve is opened, the oil enters the lower chamber through the oil inlet hole 2, and the oil in the upper chamber cannot be discharged; when the high pressure plunger moves down, the high pressure plunger overcomes the spring. After the elastic force, the low pressure plunger is pressed to move downwards. In this process, the overflow mechanism is opened, the oil discharge check valve is opened, and the oil at the upper chamber is discharged through the oil outlet hole.
• the low pressure plunger side portion has a convex rib, and the spring sleeve is sleeved on the low pressure plunger and one end of the spring abuts against the rim.
• the spring is positioned by the rim.
• the low pressure plunger includes a cylindrical body, and the overflow mechanism is a plug and an overflow spring located in the body, and the inside of the body has a seal capable of contacting the plug to form a seal.
• the sealing portion, the two ends of the overflow spring respectively act on the body and the plug and the plug has a tendency to abut against the sealing portion under the elastic force of the overflow spring.
• the overflow mechanism is only open when the high pressure state is high and the high pressure plunger is moved up. Specifically, in this state, the oil in the lower chamber can overcome the elastic force of the overflow spring to disengage the plug from the sealing surface, so that the oil in the lower chamber enters the upper chamber through the overflow mechanism.
• the spring force of the overflow spring is greater than the spring force of the medium spring of the oil discharge check valve one.
• the body is screwed with a pressure cap, and both ends of the overflow spring act on the pressure cap and the plug respectively, and the pressure cap has an oil hole for circulating oil. .
• the overflow spring and plug can be conveniently placed in the low pressure plunger and positioned.
• the oil passage hole has a "T" shape, and the lower port of the oil passage hole communicates with the lower chamber body, and the two upper ports of the oil passage hole communicate with the upper chamber body.
• This arrangement allows the high pressure plunger to be directly pressed against the pressure cap. Since the two upper ports of the oil passage are located on the side of the pressure cap, the high pressure plunger does not hinder the flow of oil.
• the oil inlet check valve 1 and the oil inlet check valve 2 are both located on the pump body side, and the oil discharge check valve 1 and the oil discharge check valve 2 are both located in the pump body.
• the oil inlet hole and the oil outlet hole are both located at the top of the upper chamber.
• the body port has a connecting seat having a large aperture
• the end of the pressing cap has an annular protruding stop
• the gap between the blocking head and the body end connecting seat has a gap
• the stop head abuts against the connecting seat and the outlets of the above-mentioned oil passing holes are respectively located at two sides of the blocking head.
• the connecting seat cooperates with the blocking head so that the upper cavity has as much space as possible.
• the position of the oil inlet hole and the oil outlet hole makes it possible to stably discharge the oil at the upper chamber through the oil outlet hole even if the upper chamber has less oil.
• a seal ring is provided between the high pressure plunger and the pump body.
• the pump body has a recessed spring seat, and one end of the spring is located at the spring seat.
• Fig. 1 is a schematic cross-sectional view showing the high pressure plunger moving up when the plunger pump of this variable is in a low pressure state.
• Fig. 2 is a schematic cross-sectional view showing the high pressure plunger moving downward when the plunger pump of this variable is in a low pressure state.
• Fig. 3 is a cross-sectional structural view showing the high pressure plunger moving up when the plunger pump of the variable is in a high pressure state.
• Fig. 4 is a cross-sectional structural view showing the high pressure plunger moving downward when the plunger pump of the variable is in a high pressure state.
• Figure 5 is a cross-sectional structural view of a cable cutter having a plunger pump of the present variable.
• variable displacement piston pump includes a pump body 1 having a cavity inside, and a pumping body 1 is provided with a low pressure plunger 3 and a high pressure plunger 2.
• the low pressure plunger 3 is disposed in the pump body 1 and can slide up and down.
• the low pressure plunger 3 divides the interior of the pump body 1 into two independent cavities: an upper chamber l a and a lower chamber l b.
• a spring 4 is disposed in the lower chamber lb, and both ends of the spring 4 act on the inside of the low pressure plunger 3 and the pump body 1, respectively.
• the side of the low pressure plunger 3 has a convex rib 3a
• the spring 4 is sleeved on the low pressure plunger 3, and one end of the spring 4 abuts against the rib 3a, and the lower cavity lb of the pump body 1
• the high pressure plunger 2 passes through the pump body 1.
• the inner end of the high pressure plunger 2 is located in the upper chamber la, and the outer end of the high pressure plunger 2 extends out of the pump body 1.
• a seal ring is provided between the high pressure plunger 2 and the pump body 1.
• the low pressure plunger 3 is provided with an overflow mechanism.
• the pump body 1 has an oil inlet hole 5 and an oil outlet hole 6 communicating with the upper cavity la, and the pump body 1 further has an oil inlet communicating with the lower cavity lb.
• the hole 2 and the oil outlet 2, the oil inlet hole 5, the oil inlet hole 2, the oil outlet hole 6 and the oil outlet hole 8 are respectively provided with an oil inlet check valve 5a, oil inlet The check valve 2 7a, the oil discharge check valve 6a and the oil discharge check valve 2 8a, and the directions of the above four check valves are consistent with the flow direction of the oil.
• the low pressure plunger 3 includes a cylindrical body 3b, the overflow mechanism is a plug 3c and a overflow spring 3d located in the body 3b, and the inside of the body 3b has a sealing portion capable of contacting the plug 3c to form a seal, and the overflow spring Both ends of 3d act on the body 3b and the plug 3c, respectively, and the plug 3c has a tendency to abut against the seal under the elastic force of the overflow spring 3d.
• the spring force of the overflow spring 3d is greater than the spring force of the medium spring of the oil check valve 6a.
• a pressure cap 9 is screwed onto the body 3b, and both ends of the overflow spring 3d act on the pressure cap 9 and the plug 3c, respectively, and the pressure cap 9 has an oil passage hole 9a through which the oil flows.
• the oil hole 9a has a "T" shape, and the lower port of the oil hole 9a communicates with the lower chamber lb, and the two upper ports of the oil hole 9a communicate with the upper chamber la.
• the oil inlet check valve 5a and the oil inlet check valve 2a are located on the pump body 1 side, and the oil discharge check valve 6a and the oil discharge check valve 2a are located on the other side of the pump body.
• the oil inlet hole 5 and the oil outlet hole 6 are located at the top of the upper chamber l a.
• the body 3b has a connecting seat 3b l having a large aperture at the port
• the end of the pressing cap 9 has an annular protruding head 9b
• the gap between the blocking head 9b and the end connecting seat 3b of the body 3b has a gap.
• the stopper 9b abuts against the joint 3b and the outlet of the above-mentioned oil passage 9a is located on both sides of the stopper 9b.
• the variable displacement piston pump can be used in a hydraulic wire crimping tool or a cable cutting tool.
• the crimping die of the hydraulic wire crimping tool must first advance without load and then contact the pressed terminal.
• the hydraulic pump only needs to overcome the spring and frictional resistance of the hydraulic cylinder, and the required pressure is small.
• the piston can be slowly advanced to reduce the impact of the piston on the hydraulic cylinder and the working head. At the same time, it can be achieved easily and effortlessly.
• the cable cutting tool is also the above principle, which includes a variable displacement piston pump, a cylinder 10 and an oil storage chamber 11.
• the variable displacement piston pump is fixedly connected to the oil storage chamber 1 1 , and the variable displacement piston pump and the oil storage chamber 1 The oil passage between the ones is communicated, and the variable displacement piston pump has a pressurizing mechanism for pressing the motive oil in the oil reservoir 11 into the cylinder 10.
• the pressurizing mechanism includes a movable handle 12 and a fixed handle 13.
• the movable handle 12 is hinged to the variable plunger pump, and the fixed handle 13 is fixed to the variable plunger pump, and the movable handle 12 is coupled to the high pressure plunger 2.
• the high pressure plunger 2 reciprocates up and down so that the motive oil in the oil reservoir 3 can be pressed into the cylinder 10 through the oil inlet passage.
• the movable handle 12 drives the high voltage column
• the plug 2 moves up, and the low pressure plunger 3 moves up under the elastic force of the spring 4.
• the overflow mechanism is closed, the oil inlet check valve 2a is opened, and the oil discharge check valve 6a is opened, and the oil flows through.
• the oil hole 2 7 enters the lower chamber lb while the oil in the upper chamber la is discharged through the oil outlet hole 6. The oil drives the piston and the mold to move quickly.
• the movable handle 12 drives the high pressure plunger 2 to move downward, and the high pressure plunger 2 overcomes the spring force of the spring 4 and then presses the low pressure plunger 3 to move downwards.
• the overflow mechanism is closed and the oil inlet is closed.
• the valve 1a is opened, the oil discharge check valve 2a is opened, and the oil enters the upper cavity la through the oil inlet hole 5, and the oil in the lower cavity lb is discharged through the oil outlet hole 8-8.
• the oil drives the piston and the mold to move quickly.
• the movable handle 12 drives the high pressure plunger 2 to move up, and the low pressure plunger 3 moves up under the elastic force of the spring 4, because the upper cavity la has a higher oil pressure, and the low pressure plunger 3 It cannot be in contact with the high pressure plunger 2 which is completely moved up.
• the relief valve is closed, the oil inlet check valve 2a is opened, and the oil enters the lower chamber l b through the oil inlet hole 7 and the oil in the upper chamber l a cannot be discharged.
• the movable handle 12 drives the high pressure plunger 2 to move downward, and the high pressure plunger 2 overcomes the spring force of the spring 4 and then presses the low pressure plunger 3 to move downwards.
• the overflow mechanism is opened and the oil discharge sheet is opened.
• the oil at the upper chamber la is discharged through the oil outlet hole 6.
• the male mold moves slowly.
• the cable shearing tool with the variable displacement piston pump is easy to operate with low pumping efficiency and high pressure.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Details Of Reciprocating Pumps (AREA)
• Reciprocating Pumps (AREA)

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Publications (1)

Family

ID=46559876

Family Applications (1)

Country Status (3)

Cited By (9)

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Citations (5)

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• 2012
  • 2012-04-09 CN CN201210100818.1A patent/CN102619739B/zh active Active
  • 2012-05-25 WO PCT/CN2012/076051 patent/WO2013152549A1/zh active Application Filing
  • 2012-05-25 DE DE112012000630.5T patent/DE112012000630B4/de active Active

Patent Citations (5)

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