The piston-type reciprocating double-action single-cylinder pumping device of vacuum pump
Technical field
The present invention relates to the piston-type reciprocating double-action single-cylinder pumping device of a kind of air extractor of vacuum pump, particularly a kind of vacuum pump, belong to field of vacuum.
Background technique
Every gas bleeding from equipment, the machinery that makes device interior reach vacuum is called vacuum pump, vacuum pump is widely used in the fields such as plastics machinery, pesticide chemical, dye chemical industry, Cryo Equipment, food machinery, electron trade, metallurgy, printing, oil, mine ground processing, according to the difference of motion mode, vacuum pump is broadly divided into: reciprocating vacuum pump, rotary vaccum pump and jet type vacuum pump.Wherein, reciprocating vacuum pump claims again piston type vacuum pump, and it is that the swept volume generating period variation of pump chamber (cylinder) is bled.
Existing conventional reciprocating formula vacuum pump structure as shown in Figure 1, comprise cylinder body 1 ' and this cylinder body 1 ' in move reciprocatingly piston 2 ', piston 2 ' by connecting rod 3 ' drive, and cylinder body 1 ' left end be equipped with outlet valve 4 ' and Aspirating valves 5 ', outlet valve 4 ' can be communicated with inner chamber of cylinder block and the external world, Aspirating valves 5 ' can be communicated with cylinder body 1 ' inner chamber and taken out container 6 ', during original state, outlet valve 4 ' and Aspirating valves 5 ' all be in closed condition, when connecting rod 3 ' drive piston 2 ' when moving right, cylinder body 1 ' left cavity volume constantly increase, pressure reduces gradually, at this moment, and Aspirating valves 5 ' open, by take out container 6 ' in gas through Aspirating valves 5 ' enter cylinder body 1 ' left chamber, until piston 2 ' finish pumping process when moving to extreme right position; Then piston 2 ' to left movement, air pressure head-on makes Aspirating valves 5 ' close, gas in cylinder body 1 ' left chamber is compressed, when the pressure in cylinder body 1 ' left chamber during greater than ambient pressure, outlet valve 4 ' be opened, make the gas of compression discharge cylinder body 1 ', until piston 2 ' finish exhaust process when moving to the left end limit position, so circulation is reached required degree of vacuum until take out container repeatedly.
Obviously, in above-mentioned air extraction structure, pumping process only carries out in the left chamber of cylinder body, and right chamber is in idle condition, and cause piston in to-and-fro motion, can only in left chamber, finish one and inhale a row, be a kind of single structural type, working efficiency is low; The air pressure in left and right two chambeies of cylinder body is inhomogeneous, so that the active force near place, the left chamber of cylinder body is large on the piston, is easy to wearing and tearing; In addition, Aspirating valves and outlet valve all are located at the same end of cylinder body, cause piston easily to produce the vibration of shear wave pessimum in the process of air-breathing and exhaust, and noise is large.
Summary of the invention
The objective of the invention is the problem that exists for prior art, proposed a kind of can make in the cylinder body about the equal piston-type reciprocating double-action single-cylinder pumping device of vacuum pump able to drawing air in two chambeies.
Purpose of the present invention can realize by following technical proposal: the piston-type reciprocating double-action single-cylinder pumping device of vacuum pump, comprise a columnar cylinder body, be installed on piston and the inner piston rod that is connected mutually with this piston in this cylinder body, described piston relatively cylinder body does reciprocating linear motion, and between described piston and cylinder body, be provided with and prevent two Sealings that cavity volume communicates of being separated by and forming by piston in the cylinder body, cylinder body is stretched out in the outer end of described piston rod, it is characterized in that, the bleed-off passage that has axial perforation in the described piston rod, described piston has the hollow structure that is communicated with this bleed-off passage, and all be installed with in the both sides of described piston and can prevent that two gases in the cavity volume from entering the one-way valve one of piston cavity, and the gas in the piston is entered in the corresponding cavity volume, the two ends of described cylinder body all are installed with and can prevent that ambient atmos from entering the one-way valve two in the corresponding cavity volume, and after described one-way valve two utilizes air pressure to open the gas in the corresponding cavity volume are discharged.
When reality is used, cylinder body should be connected on the driving mechanism of vacuum pump, driving mechanism is generally by driven by motor, the outer end of piston rod is fixed and is connected and taken out container, Sealing is separated into inner chamber of cylinder block left and right two cavity volumes of sealing, the one-way valve one of piston both sides guarantees that the gas in the piston cavity enters in the cavity volume that volume constantly increases in the cylinder body, air pressure reduces gradually in order, and the one-way valve two at cylinder body two ends discharges the gas in the cavity volume that the cylinder body internal volume constantly reduces, air pressure increases gradually.Its working procedure is as follows: when driving mechanism promotes cylinder body to left movement, the left chamber volume of cylinder body constantly increases, and air pressure constantly reduces, force the gas of being taken out in the container to back down the one-way valve one in piston left side by the bleed-off passage of piston rod, gas is entered in the left chamber of cylinder body, be that the left chamber of cylinder body is in suction condition, simultaneously, the volume in the right chamber of cylinder body constantly reduces, air pressure is more and more higher, so that the one-way valve one on piston right side keeps closed condition, and back down the one-way valve two of cylinder body right-hand member, the gas of compression in the right chamber is discharged, be that the right chamber of cylinder body is in exhaust condition, until cylinder body is when shifting limit position onto left, the left chamber of cylinder body has been finished air-breathing, and exhaust has been finished in the right chamber of cylinder body; Otherwise when cylinder body moved right, according to working principle same as above, the gas in the left chamber of cylinder body was discharged fully, and the right chamber of cylinder body then has been full of from the gas of being taken out container, has realized thus Bidirectional.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, have the air outlet hole that several axially connect and communicate with piston cavity on the described piston, described one-way valve one comprises on the end face that is fixedly arranged on described piston and can stop the elastic valve plate one of the oral area of each air outlet hole.One-way valve one mainly is made of the elastic valve plate of a sheet, and is simple in structure, easily manufactured.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, described air outlet hole is circumferential arrangement take the center of piston as the center of circle.A plurality of air outlet holes are circumferential arrangement so that gas is discharged evenly, and noise is little, and make elastic valve plate one stressed even, wear and tear little long service life.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, the middle part of described elastic valve plate one is fixed on the piston by screw.This structure is rigidly fixed on the piston middle part of elastic valve plate one, and the perimembranous of elastic valve plate one directly is resisted against on the piston, when the pressure of piston cavity during greater than the pressure in this elastic valve plate one outside, be easy to back down the perimembranous of elastic valve plate one, and air outlet hole is communicated with the corresponding cavity volume of cylinder body.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, described piston and piston rod are made one.When the relative piston reciprocates of cylinder body so that cylinder body all the time relatively piston keep same straight line motion (automatically regulating), prevent from that inboard wall of cylinder block from causing to lose circle, be conducive to increase the service life.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, described piston comprises discoidal piston body and piston cap, be shaped with the air cavity that communicates with the bleed-off passage of piston rod on the end face of described piston body, described piston cap covers the hollow structure that the air cavity oral area forms sealing, and described air outlet hole axially runs through piston body and piston cap and communicates with described air cavity.Piston body and the piston cap of piston by split fixedly formed, be convenient to process the hollow structure that communicates with bleed-off passage.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, the two ends of described cylinder body all are fixed with an end cap, all have several exhaust ports on the two end cap, described one-way valve two is to be fixed with an elastic valve plate two that can stop the oral area of each exhaust port in the outside of end cap.One-way valve two simple in structure, easily manufactured, cost is low.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, described exhaust port is circumferential arrangement take the center of end cap as the center of circle.Exhaust port is circumferential arrangement so that exhaust is even, and noise is little.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, the middle part of described piston has annular groove, and described Sealing is fixedly sleeved to be slidingly matched in annular groove and with the inwall of cylinder body.Sealing reliably is fixed on the piston, and when cylinder body is reciprocating, can also makes inner chamber of cylinder block be blocked into two cavity volumes of sealing all the time.
In the piston-type reciprocating double-action single-cylinder pumping device of above-mentioned vacuum pump, the both sides of described Sealing all have closely connected annular seal lip in inboard wall of cylinder block.When cylinder body was reciprocating, the gas in the cavity volume that air pressure raises gradually can make the automatic swelling of sealing lip near the compression end place of this cavity volume, helps further to improve sealing, thereby effectively avoided two mutual gas blowbies of cavity volume in the cylinder body.
Compared with prior art, the piston-type reciprocating double-action single-cylinder pumping device of this vacuum pump is on the basis of pot type piston cylinder, piston rod and piston are made the structure that communicates, and in the both sides of piston and the two ends of cylinder body one-way valve is set all, its simple structure, low cost of manufacture, when cylinder body is reciprocating, two cavity volumes of cylinder body all can be realized air extracting function, are a kind of double-acting structural type, and working efficiency can double, and the both sides of piston and the two ends of cylinder body thereof have symmetrical structure, evenly wear and tear little so that each moving element is stressed, noise is low; Each one-way valve only is made of the elastic valve plate of a sheet, and it utilizes the draught head of both sides and resiliently deformable occurs realizes opening and closing automatically, and structure is extremely simple, convenient fixing; In addition, piston and piston rod are made one, can obtain better concentricity, prevent that inboard wall of cylinder block from losing circle, is conducive to increase the service life.
Description of drawings
Fig. 1 is the structural representation of reciprocating vacuum pump in the prior art.
Fig. 2 is the structural representation of the piston-type reciprocating double-action single-cylinder pumping device of this vacuum pump.
Among the figure, 1 ' cylinder body; 2 ' piston; 3 ' connecting rod; 4 ' outlet valve; 5 ' Aspirating valves; 6 ' quilt is taken out container; 1 cylinder body; The left chamber of 1a; The right chamber of 1b; The 2a air outlet hole; The 2b piston body; The 2c piston cap; The 2d air cavity; The 2e annular groove; 3 piston rods; The 3a bleed-off passage; 4 elastic valve plates one; 5 screws; 6,7 end caps; The 6a exhaust port; 8 elastic valve plates two; 9 Sealings; The 9a annular seal lip.
Embodiment
Below be specific embodiments of the invention and by reference to the accompanying drawings, technological scheme of the present invention is further described, but the present invention be not limited to these embodiments.
As shown in Figure 2, the piston-type reciprocating double-action single-cylinder pumping device of this vacuum pump mainly is comprised of cylinder body 1, piston, piston rod 3 and one-way valve, wherein cylinder body 1 is movement parts, it drives by driving mechanism, and piston is relatively static, and the motion by cylinder body is so that two cavity volume generation volume-variation of being separated by and being formed by piston in the cylinder body.
Specifically, cylinder body 1 in this device is cylindrical, its two ends all are fixed with an end cap, two end cap 6, all have several circumferentially exhaust port 6a uniform and that communicate with cylinder body 1 inner chamber on 7, two end cap 6,7 the outside all is equipped with the one-way valve two that is made of elastic valve plate 28, corresponding end cap 6 is fixed in by screw in the middle part of elastic valve plate 28, on 7, elastic valve plate 28 can be made by rubber material or resilient blade, elastic valve plate 28 is blocked the oral area of each exhaust port 6a during normality, when the chamber pressure of cylinder body 1 during less than ambient pressure, ambient pressure acts on and makes it be close to end cap 6 on the elastic valve plate 28, on 7, be that one-way valve two is closed, thereby prevent that ambient atmos from entering in the cylinder body 1; When the chamber pressure of cylinder body 1 during greater than ambient pressure, will back down elastic valve plate 28, like this, the gas in the cylinder body 1 has been discharged.
Piston in this device has hollow structure, it is installed in this cylinder body 1 and is fixed as one with the inner of piston rod 3, the outer end of piston rod 3 is passed the end cap 6 of cylinder body 1 and is stretched out outside the cylinder body 1, in piston rod 3, have the bleed-off passage 3a of axial perforation, the collar extension of bleed-off passage 3a is used for connecting is taken out container, in order to guarantee certain join strength, can open outside thread processed in the outer end of piston rod 3, making piston rod 3 be taken out container with quilt is threaded connection, the internal orifice of bleed-off passage 3a is communicated with the inner chamber of piston, have an annular groove 2e on the peripheral wall of piston, fixed cover is connected to the Sealing 9 of being made by rubber material in annular groove 2e, the both sides of the seal 9 all have the annular seal lip 9a that is affixed on cylinder body 1 inwall, the inwall of the circumferential surface of Sealing 9 and cylinder body 1 forms sealing so that the cavity volume 1a of two sealings of cylinder body 1 interior formation, 1b, the both sides of piston also have several air outlet hole 2a that axially connects and communicate with piston cavity, and be fixed with the one-way valve one that is consisted of by elastic valve plate 1 by screw 5 in the both sides of piston, elastic valve plate 1 can stop the oral area of each air outlet hole, one-way valve one is identical with the working principle of one-way valve two, but it is used for preventing both sides cavity volume 1a, gas in the 1b enters piston cavity.For so that exhaust is even, air outlet hole 2a can be pressed even circumferential and distribute centered by piston.
When Practical manufacturing, piston rod 3 and piston can be made one, guarantee that both have better concentricity, make piston keep same straight line motion with respect to cylinder body, prevent that inboard wall of cylinder block from losing circle, is conducive to increase the service life; For the ease of processing the hollow structure that is used for being communicated with bleed-off passage 3a on the piston, the piston split can be made, namely make first discoidal piston body 2b and piston cap 2c, piston body 2b can make one with piston rod 3, open an air cavity 2d who communicates with the bleed-off passage 3a of piston rod 3 in the exterior edge face of piston body 2b, again piston cap 2c is covered air cavity 2d oral area, be screwed, so just can form the hollow structure of sealing, and the air outlet hole 2a that communicates with this hollow structure axially runs through piston body 2b and piston cap 2c.
The specific works process of this device is as follows: when cylinder body 1 promotes left, the sealing lip on Sealing right side is in the face of the automatic swelling of air pressure head-on, the elastic valve plate 1 on piston right side is closed, stoped the air-flow of the right chamber 1b of cylinder body to enter the left chamber 1a of cylinder body, since extraneous air pressure greater than the pressure of the left chamber 1a of cylinder body so that also autoshutdown of the elastic valve plate 28 of cylinder body 1 left end, and the volume of the left chamber 1a of cylinder body is in continuous increase, air pressure is more and more lower, force the gas of being taken out in the container to pass through the bleed-off passage 3a of piston rod 3, and open elastic valve plate 1 on the left of the piston, make air-flow enter the left chamber 1a of cylinder body, at this moment, the left chamber 1a of cylinder body enters air-breathing; Simultaneously, the elastic valve plate 1 on piston right side also is in closed condition, because the volume of the right chamber 1b of cylinder body is in continuous minimizing, air pressure is raising gradually, when air pressure during greater than the active force of the elastic valve plate 28 of cylinder body 1 right-hand member, will back down elastic valve plate 28, the beginning exhaust, until cylinder body 1 is when being pushed into limit position left, the left chamber 1a of cylinder body has finished air-breathing, and the right chamber 1b of cylinder body has finished exhaust, the one way working procedure of Here it is this air extractor.
Otherwise when cylinder body 1 oppositely resetted, according to aforesaid working principle, the gas of the left chamber 1a of cylinder body was discharged fully, and the right chamber 1b of cylinder body then has been full of from the gas of being taken out container, has realized thus Bidirectional.
This air extractor mainly applies to vacuum distillation, Vacuum Concentration, vacuum crystallization, vacuum filtration, vacuum drying and concrete vacuum operation etc., in practice, when extracting the gas that contains water vapour, can condenser be installed at the intakeport place of bleed-off passage, when extracting the gas that contains dust, can filter be installed at the intakeport place of bleed-off passage.Because the single living plug cylinder can only vacuumize a container, efficient is low, therefore, use generally combines a plurality of piston cylinders, as press the piston cylinder of circumference uniform distribution several in same level, make the cylinder body of each piston cylinder do to swing synchronously by driving mechanism, and the outer end of piston rod all connects one and is taken out container and axial restraint, swinging back and forth of cylinder body makes its relative piston do straight reciprocating motion, piston rod is made corresponding beat along the swing of cylinder body, thereby make the left side of cylinder body, the volume of right two cavity volumes changes, realize two-way bleeding, this is the mode of individual layer, also a plurality of such single layer structures can be stacked up up and down to consist of the mode of multilayer, realizes larger working efficiency; In addition, also a plurality of piston cylinders can be arranged in parallel, make the cylinder body of each piston cylinder make the synchronous reciprocating straight line motion by driving mechanism, the outer end of each piston rod all connects one is taken out container and is maintained static, and also can make the volume of left and right two cavity volumes of each cylinder body change two-way bleeding.