WO1992016748A1

WO1992016748A1 - Method for pumping liquid by multiple plunger pump and pump therefor

Info

Publication number: WO1992016748A1
Application number: PCT/JP1992/000319
Authority: WO
Inventors: Masafumi Matsunaga; Ikuo Yamagata
Original assignee: Nordson Corporation
Priority date: 1991-03-18
Filing date: 1992-03-18
Publication date: 1992-10-01
Also published as: AU1445092A

Abstract

Shear-sensitive or heat-sensitive liquid is pumped by means of a multiple plunger pump (1, 1A, 21, 21A) without allowing any of the liquid to leak out of the pump and further to set. A plurality of plungers (3, 3A, 23, 23A, 73, 73A) are provided in a liquid tank (7, 32, 71) with any one of the plungers being pressurized so as to be put in action at all times. Liquid leaking from a sealing portion (13, 13A, 33, 33A) between the plungers (3, 3A, 23, 23A, 73, 73A) and cylinders (5, 5A, 35, 35A, 75, 75A) is returned into the liquid tank (7, 32, 71).

Description

Specification

Liquid pumping method by multiple plunger pump and its pump

Technical field

The present invention relates to a multiple plunger pump for liquid pressure feeding. .

Background art

Conventionally, gear pumps and bridge pumps have generally been used as liquid pressure pumps. However, for paints and adhesives, the pigments and fillers contained in them can act as abrasives, damaging the gear flank tooth surface and significantly reducing their life. because there is a problem, such as say, a relatively small bra down jar pump of the wear occurs has been much used in _c rollers, recently, used paints and adhesives, such as UV (U l tra Vi o let ) system rather than multi It has come. These UV-based systems are mainly resins that are cured by ultraviolet rays, but many are shear-sensitive (heat-sensitive) or heat-sensitive (heat-sensitive). These are caused by the reciprocating operation of the plunger in the pump, causing shear or friction between the seal attached to the cylinder and the plunger, or between the seal attached to the plunger and the cylinder. Part of the liquid is cured by the heat generated by the action. In addition, liquids containing a large amount of inorganic particles (talc, calcium carbonate, clay, etc.) and pigments have worn plungers and seals. Thus, in a blender pump: (1) Shea-sensitive or heat-sensitive liquids tend to harden, which reduces the performance of the pump. (2) The reciprocating operation of the plunger causes the discharge fluid pressure to pulsate, or the resistance between the seal and the plunger or between the seal and the cylinder increases, causing the plunger to stop. To make the coating non-uniform.

(3) The seal and plunger or cylinder wear out, and the liquid Leakage, contaminating the area around the pump, and wasting liquid, wasting time to clean up, and hindering continuous operation.

Among these, the leakage problem in item (3) and the pulsation problem in item (2) are contradictory. If the gap between the seals is made small, the leakage will decrease but the frictional heat will increase. As the curing progresses, the pump stops and if the liquid is highly abrasive, the seal will wear. In addition, when a relatively low-viscosity (less than 10 O cps) liquid is made to have a relatively high liquid pressure (50 to 210 kg / cm ² ), there is a problem that leakage increases, and the No solution has been obtained. And item (1) was still not resolved.

In addition, a method in which the liquid is pressurized with two plungers and the liquid pressure is constantly and continuously pumped is invented and known by Nordson Corporation of the United States. The leakage (L 1) of the liquid from the seal (93) of the plunger (83) and the inside of the cylinder (96) and the local curing phenomenon of the liquid generated in the seal (93) are as follows. Not resolved. Therefore, the industry has switched to an air-play coating method that does not cause these problems. However, this method had other problems such as environmental pollution and waste of resources due to the occurrence of mist at the work site, and the industry had strongly requested the emergence of an airless spray system that solved these problems.

Multi-plunger pump that continuously pumps liquid under constant pressure to pump liquids containing sensitive and heat-sensitive paints and adhesives without reducing the performance of the pump. It is an object of the present invention to improve. Disclosure of the invention

The present invention relates to a method of operating a multiple-type plunger bomb in which a plurality of plungers are reciprocally movable, and one of them is always operated to pressurize and pump a liquid. The present invention provides a method for operating a multi-speed plunger pump characterized in that liquid is sucked in the outward stroke and liquid is pumped in the return stroke of the plunger.

Further, the present invention provides a plurality of cylinders each having one end connected to the liquid pressure feed passage and having an opening at the other end, and reciprocatingly moves into the cylinder through the opening of the cylinder. A plurality of plungers for pressure-feeding the liquid in the chamber from the cylinder to the liquid pressure-feeding passage, and the plurality of plungers; A multiple plunger pump having a plunger connected to a plunger and always operating one of the plungers, the plunger being connected to a liquid source; The plunger penetrates through the opening, and the liquid plunger penetrates the inside of the plunger. And a liquid passage communicating between them, Thus, when the plunger moves to enlarge the chamber in the cylinder, liquid is supplied from the liquid tank into the cylinder through the liquid passage. Provided is a multiple-type plunger pump characterized in that:

According to a first aspect of the present invention, there is provided a multi-link type blower pump for continuously feeding a liquid under a constant pressure, wherein the respective blowers are provided directly above each cylinder in which the respective blower is inserted. By providing a liquid tank surrounding the plunger, even if the liquid leaks from the seal part of the above-mentioned plunger, the liquid is returned to the liquid tank and the liquid leaks to the outside. How to prevent and its multiple It also provides a method of reusing the liquid in the leaked liquid tank.

According to a second aspect of the present invention, there is provided a multiple plunger pump for continuously supplying a liquid under constant pressure and pressure, wherein the plungers are provided immediately above the respective cylinders in which the respective plungers are inserted. By providing a hermetic liquid chamber provided with a liquid supply passage enclosing the plunger, even if liquid leaks from the seal portion of the plunger, the liquid is transferred to the hermetic liquid chamber. Return, that is, to prevent leakage of liquid to the outside, and at the same time, use the returned liquid again, and automatically supply liquid to the chamber by gravity hydraulic pressure or low pressure supply and its multiple plunger pump. It provides

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FIG. 1 is a side sectional view of a liquid pressure feeding multiple plunger pump according to the present invention.

FIG. 2 is a side sectional view of a multiple plunger pump for liquid pressure feeding according to the first embodiment of the first aspect of the present invention.

FIG. 3 is a comparison diagram of the stroke gauge of the two plungers in the above pump and the pressure of the liquid pressurized thereby.

FIG. 4 is a side sectional view of a liquid tank in a multiple pressure type multiple plunger pump for liquid pressure feeding according to Example 4 of the first embodiment of the present invention.

FIG. 5 is a side sectional view of a liquid pressure feeding multiple plunger pump according to a second embodiment of the present invention.

FIG. 6 is a sectional side view of a multiple pressure type multiple plunger pump for pumping liquid according to the first embodiment of the second aspect of the present invention.

FIG. 7 shows a plunger and a seal according to the second embodiment of the present invention. FIG. 4 is a side sectional view of a low-pressure seal with a chamber-type liquid chamber, which is a bellows-type seal.

FIG. 8 is a side sectional view of another example in the above drawing.

FIG. 9 is a side sectional view of a low-pressure seal according to a third embodiment of the second aspect of the present invention, which is a diaphragm-type seal.

FIG. 10 is a side sectional view of another example of the above drawing.

FIG. 11 is a side sectional view of a multiple plunger pump for liquid pressure feeding. Description of the invention with reference to the drawings.

Next, the method of the first embodiment of the present invention will be described. The present invention is an improvement in an operation method of a multiple plunger pump in which a plurality of plungers are provided, one of them constantly pressurizes the liquid, and continuously pumps the liquid. . See FIG. These plungers are going up and down with each other, but for the sake of explanation it is assumed that the first plunger 3 is on the upstroke. The inside of the cylinder 6 in which the plunger is housed has a negative pressure, and if necessary, the action of the pressurized gas loaded on the upper part of the liquid tank 7 also plays a role. The liquid L flows from the immersed liquid tank 7 through the liquid passage 8, and the inside 6 of the cylinder is filled with liquid. The state is the second plunger pump 1A adjacent to it, and when the plunger 3A drops next, the liquid inside 6A inside the cylinder is pressurized and the check valve for pumping is sent. The valve of 15 A is opened and the liquid is fed into the liquid feed passages 16 A, 17 and 18. Further, the gap between the flange 3A or 3 and the seal 13A or 13 may be larger than that in the general case. Although the seal is attached to the cylinder in the drawing, the seal may be attached to the blinder. Therefore, the gap between the seal and the cylinder may be larger than in the general case. In other words, the seal and the plunger or cylinder The purpose is to reduce the sliding resistance of the cylinder as much as possible without affecting the pumping performance. Therefore, it may be leaked. In the larger gap C t, the friction and shearing effects that occur are small, and the resulting liquid does not deteriorate. The leaked liquid is mixed with the liquid in the liquid tank 7 and used again.

In addition, as described above, when the gap Ct is larger than the gap Ct, the amount of inflow at the time of the negative pressure inside the cylinder 6 is also large, and particularly the liquid of relatively high viscosity (several hundred cps or more) In this case, the seal 13 may be removed, and the liquid passage 8 that connects the liquid tank 7 with the pressure-feeding pick-up valve 15 and the liquid tank and the cylinder 5 may also be omitted.

Therefore, as described above, the action of friction and shear at the seals 13 and 13A can be reduced, so that the present invention can be applied to a share-sensitive / heat-sensitive liquid without any problem.

The pressure in the liquid tank 7 may be normal pressure, and in the case of a liquid having a relatively high viscosity (several hundred cps or more), the pressure may be increased up to 10 kgZcm ² by a compressed gas.

Next, the structure of the multiple plunger pump according to the first embodiment of the present invention will be described. For simplicity, we will take a twin plunger pump. See FIG. In the above, the air cylinder type was described as an air cylinder type, but in actuality, there are many other types such as compressed air instead of air, or hydraulic type, electric type, crank type, rack and pinion type, cam type, etc. It is. Since any of these can be applied, they are collectively referred to simply as an automatic device. However, as shown in the graph in Fig. 3, during the pressurizing operation of the first plunger, the pressurizing operation of the other plungers is paused or waiting, and Automatically before the end of The relay is relayed to the second plunger and the pressurizing operation is started. In this way, just before the end of each pressurization operation, and alternately to another bundler (again, the first or third bundler ...) or in a circle. And pressurize as if one or all of them were pressurizing to m as a whole, that is, pressurizing action was performed in a time series. It is a driving device that continuously pressurizes the plunger, sometimes with a slight gap.

The tip of each of the plungers 3, 3A directly connected to the driving device 2 as described above is inserted into the cylinder 5, 5A in which it is accommodated, as in the general case. In the present invention, a liquid tank 7 is provided immediately above the cylinders 5 and 5A so as to surround the flanges 3 and 3A. The liquid tank 7 communicates with the check valves 15 and 15 A for pressure feeding, and the liquid top and the cylinders 5 and 5 A communicate with each other through a liquid passage 8. A suction check valve 9 is provided on the passage 8. Further, the gap C between the plunger 3 and 3A or the cylinders 5 and 5A and the seals 13 and 13A may be larger than that in a general case.

In addition, the reason why the above gap may be larger than that in the general case is that, especially when the target liquid is shear-sensitive and heat-sensitive, even if the gap is small as in the past, the friction is small. This is because heat and shearing action are likely to be generated, and the liquid is liable to be hardened, thereby preventing such a phenomenon.

In order to reduce the occurrence of the above-mentioned frictional force and shearing action, it is desirable to use a fluororesin having the lowest friction coefficient. That is, at least one of a bridger, a seal, and a cylinder is made of a fluorine-based resin, or is processed with the same resin. At that time, multiple seals A 0-ring made of fluororesin (Teflon) is more desirable than a V-packing that is stacked.

As described above, in the case of a high-viscosity liquid, the liquid tank 7 and the pressure-feeding check valve 15 and the liquid passage 8 that connects the liquid tank and the cylinder 5 are deleted, and the gap C! The liquid may be sucked directly between the plunger 3 and the cylinder 5 except for the seal 13 in order to keep the pressure large. The operation of the multiple plunger pump according to the first embodiment of the present invention will be described. See FIG. The operation of each of these plurality of plungers is performed by the drive from the talter, as described above, and in a time series, at least one of them always performs the pressurizing operation. It can be done. The operation is first started from a state where the leading portion of the first plunger 3 is located at the position of the bottom dead center D p in the cylinder 15. When the tip of the plunger 3 rises from the position of its bottom dead center Dp at a required constant speed by the action of the above-mentioned opening device 2, the inside 6 of the cylinder becomes negative pressure, and if necessary, The liquid L in the liquid tank 7 passes through the suction check valve 9 of the liquid passage 8 communicating with the liquid tank 7, while also supporting the pressurizing action of the relatively low-pressure gas loaded in the upper part of the liquid tank 7. Inhaled. When the plunger 3 reaches the top dead center Up, the inside 6 of the cylinder is filled with liquid. In this state, the system waits for the timing of starting from the vehicle 2.

On the other hand, the second Blanc jar 3 A prior to it, therefore the same operation as described above, in the position of the top dead center U _f, the silicon Nda internal 6 A, waiting already filled liquid. Before and after the description, just before the above-mentioned first plunger — 3 reaches the bottom dead center D p, the second plunger 3 A starts to descend by the operation of the driving device 2 and starts pressurizing operation. Do it. The pressure is Performed under the constant pressure, the liquid L _P pressurized to a predetermined pressure is to Tsudori pumping for Chiwe click valve 1 5 A, than it is pumped to the required apparatus through the liquid collecting passage 1 8 . In the above pressurizing operation, because the pressurized liquid L _P of sheet re Nda internal 6 A, but leaks when the gap C of the seal 1 3 A portion is large, is it within the liquid tank 7, the Absorbed by liquid L. And it will be used again.

Ni will Yo described above, by lowering the second bra changers 3 A, just before reaching its bottom dead center D _P, Ri by the driving of Ri by the same rather drive the above-described case, the top dead center U _The above-mentioned first plunger 3 waiting at _P starts descending and performs the pressurizing operation. Their to inherit the liquid pumping by the second plug changers 3 A above, Aborting and a Ku certain pressurized liquid L _P Subsequently, through the liquid collecting passage 1 8, since the pumping in the same device is there.

In addition, in such liquid pressurization, the pressurized pressure is usually 10 kg / cm ^{2 to} 210 kg / cm ² .

The gap C, between the seals 13 and 13A and the plungers 3 and 3A or the cylinders 5 and 5A, can be made larger than usual. It is effective to prevent the generation of frictional heat and shear force. However, by making the gap C! Larger, consideration should be given to the case where the liquid pressure does not rise to a required value using a liquid having a relatively low viscosity (100 cps or less). There is a need. In that case, a fluororesin having a relatively small friction coefficient may be used. That is, the seal or the Z, the plunger, and the cylinder may be made of a fluorine-based resin or may be processed with the same resin.

Further, when the liquid passing through the gap has a relatively high viscosity (several hundred CPS or more), the liquid tank 7 and the check valve 15 for pressure feeding are provided with The liquid passage 8 communicating the tank with the cylinder 1 may be omitted. In this case, liquid can be sucked from the plunger 3 and the cylinder 5.

In the above description, the plunger has been described, but it may be a plunger that moves sideways.

Example of the first embodiment of the present invention

In the embodiment, an air cylinder and its related devices are used as a driving device. The air cylinder-type plunger pump uses a balanced feed method, so it has good follow-up characteristics.The pump can be operated only when the valve of the gun 46 is open or when the flow adjustment valve or the stop valve 48 is open. It works and when closed, the liquid is kept pressurized at a constant pressure, which is ideal. First, the structure of the present example will be described. See FIG. The difference between the structure of this example and the structure shown in Fig. 1 in particular is that the liquid tank 32 is made smaller and compacted by incorporating it between the air cylinders 25 and 25A and the cylinders 35 and 35A. This is what has become. The small liquid tank 32 and the check valve for pressure feed 42, 42 A, and the small liquid tank and the cylinders 35, 35 A are communicated with each other by liquid passages 37, 37 A. The suction check valves 38 and 38 A are attached to the pump. The small liquid tank 32 is connected to a large liquid tank 40 with a liquid supply pipe 39, and a liquid transfer pump 45 is provided on the liquid supply pipe 39. In addition, a level gauge 53 is provided for the small liquid tank 32, and level switches 54, 55 are provided for the gauge if necessary. The switch is a motor for the liquid transfer pump 45. To the electrical wiring via the controller 50. From the above-mentioned cylinders 35 and 35A, the liquid pressure feed passage 41 passes through the pressure feed check valve 42, the collective joint 43, and the liquid collective passage 44, and the gun 4 as the final working tool. 6 Connected to nozzle 4 7 with piping. In addition, the gun 46 is connected to a return pipe 49 to the liquid tank 32 via a flow control valve or a stop valve 48.

The lower parts 27, 27A of the pistons 22, 22A of the heads of the bundlers 23, 23A are coaxial with each other, and these parts are They are housed in the corresponding cylinders 28, 28 A with slightly smaller diameters and serve as guides. The upper and lower portions of the above-mentioned cylinders 25, 25 A are provided with air supply / exhaust ports 61, 61 A for the operating air, and are connected to the K pipe to the five-way switching valve 65 for the operating air. . The lower part of the air cylinders 25, 25 A is connected to the air compressor 168 through supply ports 29, 29 A for constant low-pressure gas and their pipes 51, 51 A. . The lower part of the cylinder 27, 28 A for the above-mentioned parts 27, 27 A has openings 34, 34 A at the lower part, and the air limit switch 66 When the tip 62, 62A comes in contact with the lower surface of the neck 27, 27A, the air limit switch is mounted. Is activated.

Next, the operation will be described with reference to FIG. The Start of the operation, the position of the first bra changers 2 3 bottom dead center of the tip D _P2. In this case, operating air pressure A _c used to take the upper surface of the piston tons 2 2 is discharged. And on the back of the Koroga該piston t 2 2 at all times, because the air pressure P ₂ lower Ri by the operating air pressure is taking the piston t 2 2 is pushed up, both plug-changers 23 is also increased. Then, the inside of the cylinder 35 becomes negative pressure, the liquid L in the small liquid tank 32 is sucked through the liquid passage 37 connected to the cylinder 35, and the top of the cylinder 2 3 is dead. At point _UP2 , the liquid is full. Then, it waits for the next pressurizing operation.

Description will be back and forth, but just before the first plug Nji catcher - 2 3 it reaches the bottom dead center D _P2, second bra down jar pump 2 1 A starts pressurizing operation Nodea You. The five-way switching valve 65 is switched by the operation of the air limit switch 66, and the operating air Ac enters through the supply / exhaust port 61A on the second plunger pump 21A side. And press down the second piston 22 A with pressure Pi. That is, the second plunger 23 A descends. Before that, the second cylinder interior 36 A is already filled with liquid by the same suction action as in the first plunger 23 described above. The liquid is pressurized by a drop of 23 A, and the pressurized liquid LP is passed through the liquid pumping passage 41 A and used through the check valve for pumping 42 A and the liquid collecting passage 44. In this figure, a constant pressure liquid is continuously supplied to the gun 46 nozzle 47.

As described above, the switching between the operations of the two air cylinders is performed in the same way as shown in Fig. 3 above, with a slight time lap at the time of switching, and a continuous, constant liquid pumping. You can do it.

It should be noted that the liquid leaked from the gap C 2 between the plungers 23 and 23 A and the cylinders 35 and 35 A is returned to the small liquid tank 32 in the case of FIG. Is the same as

In addition, since the volume of the liquid tank 32 is relatively small, when the liquid level drops, the liquid tank 40 is connected to the liquid tank 40 via the level switches 54, 55. And automatically replenish them. When the liquid tank is at atmospheric pressure, the supply pressure may be several kg / cro: '.

Second, for liquids with relatively high viscosity (several hundred cps or more), remove the seal between the plunger 3, 3 A and the cylinder 1, 5, 5 A. Even if the liquid tank 7 and the check valves 15 and 15 for pressure feed and the liquid passages 8 and 8 A connecting the liquid tank and the cylinders 5 and 5 A are removed, the required fluid pressure is maintained. Pressure (50 kg / cm- to 210 kg / cm-) Can be. In this case, the above gap can be made larger, so that not only heat generation due to friction but also heat generation due to shear can be reduced, and in particular, the shear-sensitive and heat-sensitive high Suitable for viscous liquids.

Part 3, seals 13 and 13 A or / and plungers 3 and 3 A and cylinders 5 and 5 A are made of a fluororesin layer or those resin processed. Their use reduces frictional resistance, reduces heat generation and shear, making them suitable for share-sensitive and heat-sensitive liquids.

Please refer to Part 4, Figure 4. The bottom of the liquid tank 71 is an inclined type or a mortar type 72 b, 72 bA, and the lowest part thereof and the pumping valve 74, 74 A, and the lowest part and the cylinder 75, 7 5 A is communicated with the liquid passages 7 8 and 7 8 A. As a result, the stagnation of the liquid is eliminated, the flow is smooth, and the deterioration of the liquid in the liquid tank 71 or 72 is prevented.

Effect of the first aspect of the present invention Hu

If the liquid pumping method using the multiple plunger pump of the first embodiment or the pump is used, the liquid does not leak out of the pump, and the liquid of the assured heat or the heat sensitive is discharged. Pure liquid can be pumped without hardening. Also, conventional pumps require maintenance such as replacement of seals when 1 ccZ of liquid leaks from between the bridge and the seal. According to the present invention, the pump pumping capacity is reduced. In the case of a pumping capacity of half, for example, 30000 ccZ, even if there is a liquid leak of 1500 cc / min, there is no problem as described above. Furthermore, the liquid in the liquid tank also has the effect of cooling the plunger and seal. It is.

Next, the method of the second embodiment of the present invention will be described. The second aspect is an improvement in an operation method of a multiple plunger pump in which a plurality of plungers are provided, and one of them constantly pressurizes the liquid and pumps the liquid. . See FIG. These plungers are going up and down each other, but for the sake of explanation, it is assumed that the first plunger 3 is on the up stroke. The inside of the cylinder, in which the plunger is housed, becomes negative pressure and, if necessary, the liquid is supplied from the sealed liquid chamber 7 in which the plunger is immersed by a low supply liquid pressure. L flows in through the liquid passage 8, and when the ascending stroke ends, the inside 6 of the cylinder is filled with liquid. This state is the second plunger pump 1 A with instantaneous connection, and when the plunger 3 A descends, the liquid inside the cylinder 6 A is pressurized, and the check valve for pumping 15 A is supplied. Is opened to be fed into the liquid pressure feed passages 16A, 17 and 18. Further, the gap between the plunger 3A or 3 and the seal 13A or 13 may be larger than that in a general case. In the drawing, a seal is attached to the cylinder, but a seal may be attached to the plunger. The fact that the gap between the seal and the cylinder described above may be larger than in the ordinary case means that the sliding resistance of the seal and the plunger or the cylinder should be reduced within a range that does not affect the pumping performance. It is. Therefore, it may be leaked. The larger gap C: has less friction and shearing action in the area, does not cause the liquid to deteriorate, and leaks the liquid to the liquid in the closed liquid chamber 7. It is mixed and used again.

In addition, as described above, when the dog is more narrow than the gap C, the amount of inflow at the time of the negative pressure inside the cylinder 6 is large, and the viscosity is particularly high. (Several hundred cps or more) In the case of liquid, the seal 13 is removed, and the above-mentioned hermetically sealed liquid chamber 17 and the pressure-feeding chuck valve 15 are communicated with each other. The liquid passage 8 that connects the member 5 and the cylinder 5 may be omitted. Further, the closed type liquid chambers having the liquid supply passages may be independently provided by the number of plungers.

As described above, the action of friction shearing at the seals 13 and 13A can be reduced, so that the present invention can be applied to liquids having high sensitivity and low heat sensitivity.

Next, the structure of the multiple type bridge pump according to the second embodiment of the present invention will be described. Lift up the dual plunger pump for ease of explanation. See FIG. In the above-mentioned conventional technology, the drive system has been described as a cylinder type, but in actuality, instead of air, other compressed gas or hydraulic, electric, crank, or rack type is used. There are many types such as quad pinion type and cam type. Since any of these can be applied, they are collectively referred to simply as a drive device. First, the driving device will be described. The operation by the same device, as shown in the graph in Fig. 3, is that during the pressurizing operation of the first plunger, the pressurizing operation of the other plungers is paused or waiting, and The relay is automatically relayed to the second plunger immediately before the end of the pressurizing operation, and the pressurizing operation is started. In this way, immediately before the end of each pressurization operation, and alternately to another plunger (again, the first plunger or the third plunger ...) or in a circle. As a whole, and as a whole, one of them always performs the pressurizing operation, that is, performs the pressurizing action in a chronological series, and at the time of those relays. It is a driving device that continuously pressurizes the plunger by rubbing it slightly at intervals. The tip of each of the plungers 3, 3A directly connected to the driving device 2 as described above is inserted into the cylinder 5, 5A in which the plungers 3, 3A are housed, as in the general case. The present invention is characterized in that a sealed liquid chamber 17 is provided directly above the cylinders 5 and 5A so as to surround the plungers 3 and 3A. The closed type liquid chamber 17 and the pressure check valves 15 and 15 A, and the chamber 1 and the cylinders 5 and 5 A are communicated with each other by a liquid passage 8. Above 8 is provided a suction valve 9 for suction. Further, the gap C between the plunger 3, 3A or the cylinder 5, 5A and the seal 13, 13A may be larger than that in a general case.

In addition, the reason why the above gap may be larger than that in the general case is that frictional heat and shearing are not particularly effective in the case of a small gap as in the past, especially when the target liquid is shear-sensitive and heat-sensitive. This is because the action is likely to occur and the liquid is liable to harden, thereby preventing the liquid from occurring.

In order to further reduce the occurrence of the above-mentioned frictional force and shearing work, it is desirable to use a fluororesin having the lowest friction coefficient. That is, at least one of the plunger, seal, and cylinder is made of a fluorine-based resin, or is processed with the same resin. In this case, it is more desirable to use a 0-ring made of fluororesin (Teflon) rather than a V-packing in which a plurality of seals are stacked.

As described above, in the case of a high-viscosity liquid, the hermetic liquid chamber 7 and the check valve 15 for pressure feed are connected, and the hermetic liquid chamber and the cylinder 15 are communicated. The liquid passage 8 is deleted, and the seal 13 is also removed directly from the plunger 3 to increase the clearance C :. Liquid may be sucked in from between the 5th and the 5th. The closed liquid chamber 7 is connected to the liquid tank 10 and the like by a communication pipe 19, and between the side wall of the chamber of the chamber 17 and the plunger 3 or 3A. Is fitted with a low pressure seal 11 or 11A. At this time, the lid shall be regarded as a wall.

Pressure in the liquid tank is usually Ri general der to add an atmospheric pressure or pressure required number kg / cm ² depending on, command and liquid leakage from the low-pressure seal 1 1, 1 1 A Ho You can think that there is not. If necessary, a chamber filled with the same type of liquid, solvent, or plasticizer may be provided outside the low-pressure seal to prevent solidification of the liquid containing the slightly leaked solids.

The operation of the multiple-type blender pump according to the second embodiment will be described. See also Figure 5. The operation of each of these plurality of bridges is performed by driving rather than driving and concealing, as described above, which is performed in a chronological series, at least one of them. However, the pressurizing operation is always performed. Its operation first tip of the first plug changers 3 and the Start child from one state to the position of the bottom dead center D _P at Shi Li Nda 5. When the tip of the plunger 3 rises at a required constant speed from the position of its bottom dead center D p by the operation of the above-mentioned drive device 2, the inside 6 of the cylinder 1 becomes negative pressure. As a result, the liquid L in the chamber 7 is sucked through the suction check valve 9 of the liquid passage 8 communicating with the sealed liquid chamber 7. Its the same Shi Li Sunda first internal 6 I'm in and the child to reach the dead point U _P on top of the plastic Nja-3 and is Takashi满in the liquid. In this state, it waits for the moment when the drive unit 2 starts.

On the other hand, the second bra changers 3 A before it I by the operation similar to the above, already Ri position near the top dead center U _P, the sheet re Nda internal 6 A, already Fluid drained and waiting. Before and after the description, just before the first plunger 3 reaches the bottom dead center D, that is, after a short time lap, the second plunger 3A is driven by the movement of the driving device 2 above. It starts to descend and pressurizes. Its pressure is carried out under a constant pressure, the liquid L _P, which is pressurized to a constant pressure passes through the pumping for Chiwe' Kubarubu 1 5 A, is pumped to a required apparatus through the liquid collection communication path 1 8 Because In the above pressurized hydraulic, pressurized liquid L _P Siri Nda internal 6 A is leaking in the case between gap seal 1 3 A portion is large, in it within sealed liquid for tea Nba one 7 Therefore, it is absorbed by the liquid L. And it will be used again.

As described above, the second plunger 3 A is lowered, just before reaching its bottom dead center D, the drive than similarly ¾ braking system in the case described above, waiting in the top dead center U _P The above-mentioned first plunger 3 starts to descend and performs the pressurizing operation. Then瑭technique undergo liquid pumping by the second Blanc jar 3 A above, the constant pressurized liquid L _P subsequently without interruption, through the liquid collecting passage 1 8 is to pump in the device of the Shoyo .

The gap between the seals 13 and 13 A and the plungers 3 and 3 A or the cylinders 5 and 5 A was made larger than usual, but this was due to frictional heat and shear force as described above. It is effective to prevent the occurrence of. However, if the gap C: is made larger and the liquid pressure does not rise to a required value using a liquid having a relatively low viscosity (100 cps or less), it is necessary to consider SB. There is. In that case, a fluororesin having a relatively small coefficient of friction may be used. That is, the seal or / and the plunger and the cylinder may be made of a fluorine resin, or may be processed with the resin. Further, when the liquid passing through the upper i> d gap has a relatively high viscosity (several hundred cps or more), the above-mentioned sealed liquid chamber 17 and the pressure feeding valve 15 are In addition, the liquid passage 8 in which the closed liquid chamber and the cylinder 5 communicate with each other may be omitted. In this case, liquid can be sucked from between the plunger 3 and the cylinder 15.

In the above description, the plunger is described as a vertical plunger. However, since the champers 17 of the present apparatus are of a closed type, the plunger can be used not only in a horizontal plunger but also in any posture. can do. Further, the shape of the chamber is desirably a shape that allows the liquid to easily flow into the cylinder.

Example of the second aspect of the present invention

First, the present embodiment uses an air cylinder and its related devices as a driving device. The air cylinder type plunger pump uses a balanced feed method, so it has good follow-up characteristics.When the gun 46 valve is open, the pump will only operate when the stop valve or the flow control valve 48 is open. It works, and when closed, it is ideal because the liquid is held at a constant pressure. First, the structure of this example will be described. See FIG. The sealed liquid chamber 1 32 and the check valve for pressure feed 42, 42 A, and the sealed liquid chamber and the cylinders 35, 35 A are connected to the liquid passages 37, 37 A. Thus, a suction check valve 38.38 A is mounted on the passage. The hermetic liquid chamber 32 is connected to the liquid tank 40 via a communication pipe 39. A seal 33, 33 A is provided above the cylinder 35, 35 A. Further, low pressure seals 31 and 31 A are attached between the drive unit side wall of the hermetically sealed liquid chamber 32 and the bridge 23. And the above cylinder 3 5 From 35A, the liquid pressure feed passage 41 is connected to the gun 46 nozzle 47, which is the final work implement, through the pressure feed check valve 42, the collecting device 43, and the liquid collecting passage 44 by an SE pipe. In addition, a return pipe 49 to the liquid tank 40 is connected from the gun 46 via a stop valve or a flow control valve 48.

In addition, the air cylinders 25, 25 A that accommodate the pistons 22, 22, 25 A at the heads of the plungers 23, 23 A, respectively, are located above the air cylinders 25, 25 A. 61 A is provided, and is connected to the operating air five-way switching valve 65 by piping. The lower part of the air cylinders 25 and 25 A is a cylinder that accommodates the glue parts 27 and 27 A of the bistons 22 and 22 A.

The lower part of the air cylinder 25, 25 A is connected to the air inlet 29, 29 A for constant low-pressure gas and its piping 51, 51 A. 6 Connected to 8. Also, the lower part of the cylinder 27, 28 A for the above-mentioned parts 27, 27 A has openings 34, 34 A at the lower part, and the holes 62, 28 A have the tip 62, 2 of the gear limit switch. The air limit switch is operated when the 62 A is mounted and the head 62, 62 28 contacts the lower surface of the class 27, 27 A.

Next, the operation will be described with reference to FIG. The start of this operation is the position of the bottom dead center _DP2 of the first plunger 23 tip. In this case, the operating pressure Ac applied to the upper surface of the piston 22 is discharged to normal pressure. However, since an air pressure P: lower than the operation air pressure is always applied to the back of the piston 22, the piston 22 is pushed up, and the plunger 23 also rises together. Then, the inside of the cylinder 35 becomes negative pressure and passes through the liquid passage 37 connected to it, and the sealed liquid chamber is closed.

3 Liquid L in 2 is sucked in and reaches top dead center U _F2 of plunger 2 3 Liquid is filled. Then, it waits for the next pressurizing operation. Description is back and forth, the immediately preceding first plug Nji catcher - 2 3 it reaches the bottom dead center D _{P 3,} Ru Nodea the second plan jars pump 2 1 A starts pressurizing operation. By operating the air limit switch, the five-way switching valve 65 is switched, and the operating air Ac enters through the exhaust port 61A of the second plunger pump 21A and enters the second air port. Press down the second piston 22 A and press down. That is, the second blanker 23 A descends. Prior to that, the second cylinder 1 interior 36 A is already filled with liquid by the same suction action as in the first cylinder 23 described above, so that the second cylinder The liquid is pressurized by the drop of 23 A, and the pressurized liquid Lp is to be used through the liquid pumping passage 41 A and the pumping thin film check valve 42 A and the liquid collecting passage 44. In the device, in this figure, the liquid at a constant pressure is continuously supplied to the gun 46 and the nozzle 47.

As described above, switching between the operations of the two air cylinders is performed in the same way as shown in Fig. 3 above, with a slight time lap at the time of switching, and continuous constant pressure pumping. You can do that.

It should be noted that the liquid leaked from the gap C 2 between the plungers 23 and 23 A and the cylinders 35 and 35 A is returned to the closed liquid chamber 32. Same as in 5.

Part 2, the force showing the vacuum seals 11 and 11 A between the plunger and the side wall of the drive section of the hermetically sealed liquid chamber in the multiple-type bridge pump shown in Fig. 5; When a seal is used, there are various problems such as high frictional resistance in the moving part, insufficient sealing against negative pressure, and short life. In this embodiment, as described above, a low-pressure sealing device having no moving parts is employed. That is, refer to Figs. 7 and 8, which are bellows. I want to be. The lower end of the bellows 54 is placed on the outer periphery of the plunger through hole on the deflector side wall 52 of the sealed liquid chamber 1, and the upper end is placed on the flange 57 fixed on the plunger 53. It is fixed to. As the bellows 54 moves up and down as shown by the phantom line in the figure, the bellows 54 completely seals the gas even if it expands and contracts, so there is no sliding part, so there is no friction or wear. It can withstand long term complete gas sealing. In FIG. 7, a bellows may be installed outside the sealed liquid chamber or may be housed in the chamber (see FIG. 8). Third, a diaphragm is used in place of the bellows in the second embodiment. See FIG. 9 and FIG. The advantage is the same as that of the bellows described above, but by reducing the stroke of the plunger 63, the problem that the liquid stays in the concave portion of the bellows can be solved. In FIG. 9, the diaphragm 64 is installed outside the closed liquid chamber, but it may be stored in the chamber (see FIG. 10). in the case of one hundred c _PS higher) liquid, the plunger 3, 3 a and Series Nda 5, 5 seal 1 between a 3, 1 3 except Ri preparative a, further sealed fluid chamber one 7 and pumping Even if the fluid check valves 15 and I5A and the fluid passages 8 and 8A that connect the sealed fluid chamber 1 and the cylinders 5 and 5A are removed, the fluid pressure is maintained at the required pressure.

(50 kg / cm ² to 210 kg / cm ² :). In this case, the above gap can be made larger, so that not only heat generation due to friction but also heat generation due to shear can be reduced, and it is particularly suitable for a shear-sensitive and heat-sensitive high-viscosity liquid. is there.

Part 5. Seals 13 and 13 A or / and plungers 3 and 3 A and cylinders 5 and 5 A are made of fluororesin or processed with them. Their use results in less frictional resistance, less heat generation and less shear, making them suitable for shear sensitive liquids.

Effect confectionery of the second embodiment of the present invention

The use of the method for pumping liquid by the multiple plunger pump of the present invention or the use of the pump prevents the liquid from leaking out of the pump, and also cures the liquid which is sensitive or heat-sensitive. Instead, pure liquids can be pumped. In addition, liquid supply into the relatively small hermetic liquid chamber is automatic, and because it is hermetic, it can be used in any position of the pump. In addition, in the case of the conventional bomb, when liquid leakage of 1 cc / min was found between the banger and the seal, maintenance such as replacement of the seal was required. In the case of a pumping capacity of half of, for example, 300 cc ccZ, even if there is a liquid leak of 1500 cc / min, there is no problem as described above.

Claims

The scope of the claims

1. A method of operating a multiple plunger pump in which a plurality of plungers are reciprocally movable, and one of them is always operated to pressurize and pump a liquid.

In the plunger's outbound travel, it sucks in liquid,

A liquid pumping method using a multiple plunger pump, wherein the liquid is pumped in the plunger return stroke.

2. A method of operating a multiple plunger pump in which a plurality of plungers are provided, and one of them is always pressurized to pump the liquid under pressure.

In the ascending stroke of the plunger (3 or 38,...), The plunger (3, 3 A, ...) is soaked and the liquid tank (7) is in contact with the atmosphere and the liquid level. A liquid pumping method using a multiple-type plunger pump, characterized in that liquid is sucked into a cylinder (5 or 58,) downstream of the pump and the liquid is pumped during its descending stroke.

3. The liquid pumping method using a multiple plunger pump according to claim 2, wherein the liquid is a liquid sensitive or Z- and heat-sensitive.

4. The multiple brass according to claim ² , wherein the pressure in the liquid tank (7) is pressurized by compressed gas to within 10 kgZcm2 and smaller than the pressure. Liquid pumping method using a anger pump.

5. A method of operating a multiple plunger pump in which a plurality of plungers are provided, and one of them is always pressurized and pressurized to pump the liquid, the plunger (3 or 3A, ... ), The plunger (3, 3 A,…) is immersed in the liquid supply passage. The liquid (L) is sucked into the cylinder (5 or 5 A, ...) downstream of the sealed liquid chamber (7) provided with A liquid pumping method using a multiple-type plunger pump.

The liquid pumping method using a multiple plunger pump according to claim 5, wherein the liquid is a share-sensitive or / heat-sensitive liquid.

A plurality of cylinders having one end connected to the liquid pressure feeding passage and the other end having an opening;

The liquid is reciprocally inserted into the cylinder through the opening of the cylinder, and forms a chamber between the cylinder and the cylinder. A plurality of plungers for pumping the liquid in the chamber to the pumping passage;

A multiple plunger pump connected to the plurality of plungers and having a plunger coarse movement source that always operates one of the plungers;

A liquid tank that is connected to the liquid 漯, is in fluid communication with the opening of the cylinder, has the plunger penetrating therethrough, and receives the liquid through the opening;

A liquid passage communicating between the other part of the cylinder and the liquid tank,

Thus, when the blender moves to enlarge the chamber in the cylinder, liquid is supplied from the liquid tank into the cylinder through the liquid passage. A multi-stage plunger pump characterized by having such a configuration.

8. The plunger is arranged so as to be movable up and down.

7. The multiple plunger pump according to claim 6, wherein the liquid tank is arranged at an upper part of a die. .

9. The multiple plunger pump according to claim 7, wherein the liquid surface of the liquid tank is in contact with the atmosphere.

10. The multiple pump according to claim 7, wherein the liquid tank is sealed.

11. In a multiple plunger pump in which a plurality of plungers are provided loosely and one of them is always pressurized and the liquid is continuously supplied under pressure, a. A drive unit (2) consisting of a drive unit for driving the drive unit is provided, and b. A plunger (3, 3A, ...) is connected to the drive unit of the drive unit (2). C. That the plunger (3, 3A, ...) is penetrated from the top downward in the non-sealed liquid tank (7), and d. A cylinder (5, 5A, ...) for the plunger (3, 3A, ...;) is provided below the liquid tank (7), and e. The liquid discharge side of (5, 5 A, one) is connected to the liquid pressure supply passage (16, 16 A, one). F. The liquid pressure supply passage (16, 16 A , 1) A check valve for pumping (15, 15A,...) Is provided at the top, and g. The liquid tank (7) and a check valve for pumping (15, 15) are provided. That the liquid tank (7) and the cylinder (5, 5A) are in communication with each other by the liquid passages (8, 8A, ...); h. The other end of each of the above-mentioned pressure feed passages (16, 16A, ...) is connected to the liquid collecting passage (18), and

Multi-function plunger pump characterized by ".

12. The multiple blower pump according to claim 10, wherein the driving device is driven by a compressed gas.

13. In the above liquid passage (8, 8A, ...), there is a suction check valve (9,

9A, ···) and j. Between the above-mentioned plunger (3, 3Α,… :) and the cylinder (5, 5A, ···) Seal (13,

13. The multiple plunger pump according to claim 10, wherein the multiple plunger pump is provided with:

14. Make sure that the seal (13, 13 A, ...) or the plunger (3, 3 A, ...) and the cylinder (5.5 A, ...) are made of fluororesin. 10. The multiple pump according to claim 10, wherein the pump is made of a resin or processed by a resin.

15. A multiple-type plunger pump in which a plurality of plungers are provided and one of them is always pressurized to continuously pressurize and pump the liquid, a. A drive unit (2) consisting of a drive unit for driving the puller is provided; b. A plunger (3, 3A,...) Is connected to the drive unit of the drive unit (2). C. The plunger (3, 3 A,...) Penetrates the sealed liquid chamber (7), and d. A low-pressure seal (11, 11A,…) shall be provided between the driving part side wall of the chamber (7) and the plunger (3, 3A,…). E. A cylinder (5, 5 A,… :) for the plunger (3, 3 A, ...) is provided downstream of the closed liquid chamber (7). F. The liquid discharge side of the above cylinder (5, 5 A,…) is connected to the liquid pressure feed passage (16, 16 A,…). g. A check valve for pumping (15, 15A,…) is provided on the liquid pumping passage (16, 16A,…). H. The other end of each of the liquid pressure feeding passages (16, 16A, 1) is connected to the liquid collecting passage (18), and i. A seal (13, 13A, ... ') must be installed between the plunger (3, 3A, ...) and the cylinder (5, 5A, ...). A multi-stage plunger pump characterized by the following.

16. The closed liquid chamber (7) and the pressure-feeding check valve (15, 15A, ···) are connected to the closed liquid chamber (7) and the cylinder (5, 5). 5A,...) Are connected to each other by the liquid passage (8, 8A,…), and the suction tube valve (8, 8A,…) 9. The multiple plunger pump according to claim 14, wherein: (9, 9 A, ...) is provided.

17. The multiple plunger pump according to claim 15, wherein the deer device is driven by a compressed gas.

18. The multiple plunger pump according to claim 15, wherein the low-pressure seal (11, 11A, ...) is a bellows-type seal.

19. The multiple-type plunger pump according to claim 15, wherein the low-pressure seal (11, 11A, ...) is a diaphragm seal.

20. Seal (13, 13 A, · ■ ·) or Z and plunger (3, 3 A,

16. The multiple plunger pump according to claim 15, wherein the cylinders (5, 5A,...) Are made of a fluorine-based resin or are processed with the resin.