DE2125605A1 - Piston pump operated by pressure medium, in particular for the dosed and calibration-compliant dispensing of liquids - Google Patents

Description

Piston pump operated by pressure medium, in particular for metered and calibrated dispensing of liquids.

The invention relates to a pressure fluid operated piston pump, especially for the dosed and legal-for-trade delivery of liquids, e.g. of Lubricating oil from containers, with one displaceable in a cylinder tube, at least piston pressurized on one side, a device for reversing the Piston, and with one check valve each on the inlet side and the outlet side the pump.

A pump of this type is known in which the device to reverse the piston a manually operated pressure medium supply, i.e. in this case has the compressed air supply controlling valve. In a position of Valve is admitted pressure medium to one side of the piston, so that the piston under the action of compressed air moved against the force of a spring will. In the other position of the valve, the compressed air is vented so that then the piston is returned to its original position under the force of the spring. An automatic delivery of various precisely measured quantities is known Pump not possible due to the design of the reversing valve.

The invention is based in particular on the object of a pressure medium-operated To create a piston pump with which it is possible to dispense different amounts of liquid to submit in the simplest possible way. In accordance with the invention this essentially becomes achieved in that the device for reversing the piston is a programmable Has control device for causing an actuation of the pressure medium supply cooperates with a device which senses the position of the piston.

The invention achieves that the programmable control device any amount to be dispensed is entered, after which the control device is in communication with the device sensing the position of the piston that the 1) return medium supply controlling valve or the like actuated accordingly, i.e. actuated until the in the programmable controller dispenses the amount entered by the pump is. In practice, this means that only a one-time setting of the Quantity is required and that afterwards all further processes relating to the delivery this amount can be carried out automatically by the pump.

According to a preferred embodiment of the invention, the programmable Control device designed as an electrical device, which a pressure medium supply contains controlling valve.

The device sensing the position of the piston can preferably have magnetically operated switches associated with the programmable controller are electrically connected. With such an implementation, the Pistons For example, carry at least one magnetic element with the in the end regions The piston arranged magnetically operated switches works together.

For the arrangement of the magnetically actuated piston position sensing Switches can, for example, be arranged in a rod-like element be, which is arranged extending through the piston in the cylinder tube and from which one end extends out of the cylinder tube. The rod-like Element can preferably be hollow, in which case the magnetic switch by suitable Means can be arranged in the rod-like element, and it continues may be useful, the rod-like element after attaching the magnetic switch and pour their lines with an insulating compound, for example resin.

Further advantageous developments of the subject matter of the invention are placed under protection in additional claims.

The invention is illustrated below with reference to the drawing, for example explained.

Fig. 1 is a vertical section of one embodiment a pump according to the invention.

FIG. 2 is a view similar to FIG. 1 of a modified embodiment the invention.

FIG. 3 is a view similar to FIG. 1 of a further modified one Embodiment of the invention.

Fig. 4 is a view similar to Fig. 1 of yet another modified one Embodiment of the invention.

According to Fig. 1, an embodiment of a pressure medium-actuated, For example, with compressed air operated pump on a housing, which consists of a Cylinder tube 1, a head piece 2 and a foot piece 3 is formed. In the cylinder tube 1, a piston 4 is displaceable, which by means of suitable seals 5 against the Cylinder tube 1 is sealed.

The piston can move between two end positions, from which one formed by one on the head piece 2 Shoulder 6, and from those the other is formed by a stop part-7, which is attached to a through the Piston 4 extending therethrough tube 8 is formed or attached, the details of which will be described later.

In the head piece 2, a chamber 9 is formed into which a Passage 10 pressure medium, for example compressed air, can be admitted. Simultaneously the passage 10 can also be used to discharge pressure medium from the chamber 9 will. For the control of the supply and the relief of the pressure medium is one programmable control device provided, their execution and function later is described. The piston 4 is on its side facing away from the head piece 2 spring-loaded, by means of a helical compression spring 12, one end of which is supported on the piston 4 ′, and the other end thereof is supported on a shoulder surface 13 which is formed at the upper end of the base 3.

In the embodiment shown, the piston stroke is determined by the position the shoulder or stop surfaces 6 and 7 determined. The piston stroke can if there is desired can be changed as described below.

A further tube 14 is arranged around the cylinder tube 1 in such a way that that between it and the cylinder tube 1, an annular space is formed in which medium to be pumped can be conveyed. This annular space between the both tubes 1 and 14 is one or more openings 15, which are close to the lower End of the cylinder tube 1 are formed with the interior of the cylinder tube 1 in Link. The interior of the cylinder tube 1 is in turn over suitable passages and in connection with the medium to be pumped via a conventional check valve. At the upper end of FIG. 1, the annular space ends in the head piece 2 and stands there via a conventional spring-loaded non-return valve 16 to the discharge line in Connection, which is indicated by a connecting piece 17.

The connection from the inside of the cylinder tube 1 to the one to be pumped Medium takes place via one or more formed in the upper part of the base 3 Passages 18, on which a downwardly formed by two sleeves or pieces of pipe Annular space 19 connects, the lower end of which in turn has one or more passages 20 is connected to the space in which the check valve 21 is arranged.

The programmable controller (not shown) is preferred an electrical control device attached to any convenient, also removed is arranged lying point and via a cable line to the valve 11 for the admission of pressure medium into the chamber 9 and for the discharge of pressure medium from this chamber 9 is connected. In this case, this is a pressure medium control valve suitably a solenoid operated or electromagnetically operated valve. the Control device 11 is further designed so that åe after the desired with the Pump from the amount to be added an adjustment is made, after which the required number of actuations of the pressure medium control valve takes place automatically.

For such an operation it is necessary to have the control device to be supplied with information regarding the position of the piston 4. For this Purpose are provided within the cylinder tube 1 magnetic switch 22, 23 of each of which is arranged in an end region of the piston stroke. To work together with these magnetic switches 22, 23 the piston 4 is provided with a magnetic element, which in the described embodiment has an annular permanent magnet 24, which is arranged in the piston 4 and whose diameter is only slightly larger than the diameter of the rod extending through the piston 8 is. It is it is desirable to place the magnet 24 close to the rod 8, so that the distance between the magnet 24 and the magnetic switches 22, 23 as possible becomes small.

The permanent magnet in the piston 4 can also have a different design be, for example, be rod-shaped.

The magnetic switches 22 and 23 are together with their electrical Ladders arranged in the switch tube 8. This arrangement can be different Way. For example, the magnetic switches 22, 23 with their conductors initially arranged at predetermined distances from one another and by, for example a small sleeve can be fixed in place by means of adhesive tape, with then the sleeve 25 pushed into the switch tube 8 and in an appropriate manner, for example by pouring resin od.

Like. Is set in the correct position. The switch tube 8 itself can then through the piston 4 through into the cylinder tube? introduced will. Here, the lower end of the switch tube 8 is inserted into the base 3, where it is arranged in a sealed manner using appropriate seals 26, 27 will. At the upper end of the switch tube 8 can be fixed by a nut 28, which is screwed into the upper end of the head piece 2.

The electrical conductors of the magnetic switches 22 23 are then in a suitable Way connected to the programmable controller.

The nut 28 is firmly connected to the switch tube 8. aside from that the nut 28, as said, is connected to the head piece 2 via a thread. Will now the nut 28 is rotated, the height position of the switch tube 8 in the Pump changed. As a result, the position of the lower piston stroke stop 7, the is connected to the switch tube 8, changed accordingly, creating a piston stroke adjustment is possible because the upper stop 6 for the piston 4 in the head piece 2 remains unchanged.

Another feature of the invention is that a swimmer 29 is provided, which gives an indication, if in the container, from soft liquid or the like.

is to be dispensed, there is not enough liquid left. In the embodiment shown, the float is inside the foot piece 3 arranged. The float 29 is provided with a central opening so that it , as can be seen from the drawing, on the switch tube 8 or along this can move freely. For the upper limit of the movement of the float 29 is on the base 3 formed a stop surface in an appropriate manner. as well is in the lower part of the foot 3 another stop surface for the swimmer 29 formed.

As can be seen from the drawing, the switch tube extends 8 to near the lower end of the foot piece 3. Is in a suitable place A further magnetic switch 30 is arranged here in the switch tube 8.

The float 29 contains magnetic material, for example in In the form of chips or powder or in the form of a ring magnet that is in the base material of the float is embedded, so that when the float 29 drops when the liquid level reaches the area of the magnetic switch 30, this is actuated. The magnetic switch 30 is also connected to the control device via an electrical line.

The float 29 is arranged so that the switch 30 so timely is operated so that the entry of air into the pump is avoided. When actuated of the switch 30, the control device receives corresponding information. the The control device then stops the liquid dispensing after completion, the last one started piston stroke. In this way it is reliably avoided that air gets into the pump penetrates. The ingress of air is not permitted for calibration purposes.

The connection of the room in which the float 29 is located is, with the medium to be pumped takes place at the lower end via a passage 31, who gets through the lower part of the foot piece through to the outside extends, and at the upper end via a passage 32 which passes through the upper part of the foot piece 3 is guided to the outside.

It is to be understood that the cylinder tube 1, the outer tube 14 and the sleeves 33 and 34 of the foot piece 3 each with the head piece 2 and the foot piece 3 are connected in a medium-tight manner.

The operation of the pump described so far is as follows. It it is assumed that the piston 4 is in its upper position shown in FIG and that accordingly -in the cylinder tube 1 contain liquid to be pumped is. Should now an amount of liquid corresponding to the amount that the piston 4 on a stroke is required, the control device is set in such a way that that the pressure medium control valve is actuated twice. The first actuation leads to the fact that pressure medium is admitted into the chamber 9 via the passage 10, so that the piston 4 is pressed downwards against the force of the spring 12 as shown in FIG will. Here, of course, the check valve 21 is on the suction side of the Pump closed, so that the liquid contained in the cylinder tube 1 through the opening 15 or the openings 15 at the lower end of the cylinder tube 1 through is pressed into the annular space between the cylinder tube 1 and the outer tube 14 and in this annulus rises upwards, where it passes through the outlet valve 16 exits into the delivery line. When the piston 4 reaches its lower end position, which is through the stop 7 is determined, reaches the magnet 24 carried by it in the area of the magnetic switch 31 so that it is actuated. By doing this of the magnetic switch 23, the switching of the pressure medium control valve takes place via the control device 11 such that the previously admitted pressure medium is now omitted, so that the Piston 4 is now under the action of spring 12 upwards moved into its position shown in Fig. 1.

During this movement there is a suction stroke, during which through the now opening check valve 21, the passages 20, 19 and 18 to be pumped Medium is sucked into the interior of the cylinder tube. The dispensing valve 16 is here closed.

If a larger amount of liquid is to be dispensed, for their Dispensing several piston strokes are required, the corresponding one is set on the control device Number of piston strokes or actuations of the pressure medium control valve 11 is set. The mode of operation is essentially as described above, in addition, when the piston 4 reaches its upper end position, through the magnet 24 carried by it, actuation of the magnetic switch 22 takes place, which again via the control device for a further switchover of the pressure medium control valve leads.

Should the liquid level be corrected during the delivery of liquid in the container from which the pump is being pumped sink so far that the float 29 reaches the area of the magnetic switch 30, the latter is actuated and A signal is sent to the control device via its electrical connection, which then conveniently gives the operator an indication that the liquid level has dropped to a certain value.

The details of the execution of the programmable controller are not shown and also not described, since a person skilled in the art is able to if instructed to do so, an appropriate control device, for example in the form of an electrical circuit.

In Fig. 2 is a modified embodiment of a pump according to of the invention in which the operation of the operation of the embodiment according to FIG. 1 is practically identical, but in which the constructive Execution is modified. The same or corresponding parts as in the embodiment 1 are denoted by the same reference numerals.

The cylinder tube 1 is in turn at the upper end with a head piece 2 and provided with a base 3 at the lower end. The piston 4 is in turn in the cylinder tube 1 is arranged displaceably and is facing the head piece 2 on its Side acted upon by pressure medium, while he is on its opposite side is loaded by means of the spring 12, the ends of which are in turn on the piston 4 or on a shoulder 13 formed in the base 3.

The control of the pressure medium supply takes place as in the embodiment according to FIG. 1.

The switch tube containing the magnetic switches 22> 23 and 30 In this embodiment, 8 is partially arranged within a riser pipe 35, which, starting from the Eopfstück 2, extends over part of the length of the cylinder tube 1 extends. At its lower end, the riser pipe 35 carries the lower limit stop 7 for the piston stroke.

The riser pipe 35 takes the place of the in this embodiment outer tube 14 of the embodiment according to FIG. 1.

Accordingly, when the piston 4 is moved downward, i.

medium to be pumped in the riser pipe 35 during its pressure stroke pushed upwards and occurs via the dispensing check valve arranged on the head piece 2 16 into the delivery line.

In this embodiment, the float 29 is on a piece of pipe 36 of the foot piece 3 arranged displaceably. The lower end of the switch tube 8 extends into the pipe section 36 here. The medium connection between the container from which the pump is to be carried out. and the interior of the cylinder tube takes place here via the check valve 21, the interior of the pipe section 36 and over an opening 37 which connects the upper end of the pipe section 36 with the interior of the cylinder tube 1 connects.

In this embodiment, the piston 4 is secured by means of suitable seals guided on the pipe section 35 in a sealing manner.

In the embodiment according to FIG. 2, the pipe section 35, which carries the lower piston stop, connected to the head piece 2 via a thread. If there is a relative rotation between the head piece 2 and the pipe section 35, then the relative position between the piston hub stop 6 in the head piece 2 and the piston stroke stop 7 on the pipe section 35 and accordingly the piston stroke changed.

In Fig. 3, a further modified embodiment is described, the mode of operation of the mode of operation of the embodiment according to FIGS. 1 and 2 is essentially identical, i.e. the piston 4 is on its head piece 2 facing side with pressure medium applied, while he is on its opposite Page is loaded by the spring 12. Extends through the piston 4 the switch tube 8 containing the magnetic switches 22, 23 and 30, as in the embodiment according to-Fig. 1.

The according to Fig. 3 upper end position of the piston 4 can by means of a Adjustment part 3? be changed, the sealing in a bore of the head piece 2 is axially guided and its position is adjustable by an adjusting part 38, the again, for example, by means of screws (not shown) in its relative position is adjustable to the head piece 2 and thereby determines the position of the control part 37, the lower end face of which forms the stop face for the piston 4. In the representation According to FIG. 3, the actuating part 37 is arranged in its uppermost position accordingly maximum piston stroke.

In this embodiment, too, an outer tube 39 is provided, which forms the riser pipe and via the check valve 16 to the discharge line connected is.

However, the tube 39 does not extend the full length of the cylinder tube 1, but only up to a point shortly beyond, to the lower one Limiting stop 7 is arranged for the piston stroke. In the cylinder tube 1 are in turn one or more openings 15 are formed, via which a medium connection between the interior of the cylinder tube and the annular space between the cylinder tube 1 and the riser pipe 39 is created.

The lower limit stop 7 for the piston stroke has a the switch tube 8 arranged around the part, which is at the upper end of a pipe section 40 is formed, which extends within the cylinder tube up to the base 3, i.e. extends to the end of the cylinder tube 1. One passage with one size corresponding to the size of the pipe section 40 is formed in the foot piece 3 and extends down to its lower end. The switch tube 8 is up close to the lower one End of Fuß'stückes 3 in the above passage where the magnetic switch 30 is arranged, which cooperates with the float 29. For better support of the switch tube 8 is in. The pipe section 40 is an additional bearing point or Support point 41 created. The float 29 is in this embodiment essential ringfört-.g and is arranged in an annular space that is surrounded by two sleeves 33 34 is formed in the foot 3. This annulus is at the lower end to the environment open and is at the upper end via an opening 32 with the environment or with the medium to be pumped in connection.

At the junction between the cylinder tube 1 and the base 3, a substantially annular component 42 of the foot piece 3 is provided, which the space between the pipe section 40 and the cylinder tube 1 fills and on its upper surface creates the support surface for the spring 12.

In this embodiment, the medium connection takes place between the container from which to pump should and the interior of the Cylinder tube 1 via the check valve 21, the interior of the foot piece, i.e. the Annular space that is present between the switch tube 8 and the sleeve 33, and about Openings 43 formed in the pipe section 40.

The operation in this embodiment is similar to the operation of the embodiment described above, so that a repeated description is not required here he follows.

In Fig. 4 is a further modified embodiment of the invention shown, which differ from the previous embodiments essentially thereby differs in that the piston 4 is acted upon by pressure medium from both sides so that the spring 12 is not present.

According to FIG. 4, the head piece 2 and the foot piece 3 are designed in this way as in the embodiment according to FIG. 3 with the exception that the dispensing opening is not formed in the head piece, but at a lower point.

For the application of the piston 4 on its of the head piece 2 side facing away with pressure medium, the cylinder tube is divided so that'unter a pressure medium chamber 44 is formed on the piston 4 via an intermediate piece 45 formed passage 47 and a pipe 47a or the like with the pressure medium control valve 11 communicates.

Another pipe section closes at the bottom of the intermediate piece 45 46, which practically represents the lower part of the cylinder tube 1 and extends up to the foot piece 3, the execution of which in the description of the embodiment is already described in accordance with FIG. 3, it being noted that of course no spring 12 is provided.

The piston 4 is on its surface facing away from the head piece 2 a tube 48 is connected, which extends through the intermediate piece 45 therethrough and is guided in this sealing. The tube 48 bears at its lower end Slider 49, which is guided in the lower pipe section 46 in a sealing manner. The slider 49 represents the liquid piston or the piston for the medium to be pumped. A plurality of medium passages 50 are formed in the piston 49 ', the upper ends of which pass through a slide valve member 51 which is arranged around the pipe 48, depending on the prevailing pressure are closed or open, ie.

when the pressure above the valve member 51 is greater than the pressure is in the passages 50, the passages 50 are closed and vice versa. at open passages 50, a medium connection to the dispensing nozzle 17 is created, which is formed in the intermediate part 45.

As in the embodiments described above, this is the magnetic switch 22, 23 and 50 supporting switch tube 8 is inserted centrally into the pump and extends up close to the lower end of the foot piece 3. Accordingly, it is not only the piston 4 but also the piston 49 on the switch rohr'8 sealingly guided.

The medium connection between the inlet end and the outlet end of the The pump takes place via the check valve 21, the interior of the base 3, the interior of the pipe section 46, the passages 50 and over the interior of the intermediate piece 45 with the dispensing opening 17.

To explain the mode of operation of this embodiment, it is assumed that that the parts are in the position shown in Fig. 4 and that the Pipe section 46 is filled with medium to be pumped. If now under the effect the control device and the pressure medium control valve 11 pressure medium into the chamber 9 is admitted, the pistons 4 and 49 are moved downwards as shown in FIG. While this movement is due to the pressure of the Pumping medium below of the piston 49 lifted the valve member 51, so that the medium from the pipe section 46 through the passages 50 in the piston 49 to the other side of the piston 49 flows. When the piston 4 reaches its lower end position, takes place via the Magnet 24 and the magnetic switch 23 are reversing and both pistons 4, 49 are then moved upwards according to 'Fig. 4, under the action of pressure medium, which is let into the intermediate piece 45 via the line 47 and the passage 47 is, at the same time the chamber 9 is relieved. During this upward movement the valve member 51 closes the passages 50 in the piston 49, so that the above The medium located in the piston 49 is discharged through the discharge opening 17 is, at the same time from the piston 49 medium to be pumped into the pipe section 46 is sucked. How it works when a quantity is dispensed that contains a plurality of Piston strokes required is the same as used in conjunction with the others above Embodiments has been described.

The piston 4 is in all embodiments by means of a suitable one Seal, for example one or more O-ring seals 4a, which are in a corresponding Piston groove is or are arranged along the switch tube 8 or the tube 35 or the tube 48 out sealing.

It should be noted that in the embodiments 2 to 4, the lower End of the foot piece has an annular base, opposite which the Check valve 21 is set back axially.

The invention creates a piston pump operated by pressure medium, whose execution is made so that different exactly in a very simple way measured quantities, e.g. of lubricating oil from a container, can be dispensed automatically can by simply setting the amount to be dispensed on the control device to become needs, after which the number of necessary reversal processes of the piston is carried out automatically. As is known per se, the piston stroke is adjustable,

Claims (16)

Claims v 5 pressure medium-operated piston pump, in particular for the dosed and calibrated dispensing of liquids, e.g. of lubricating oil from containers, with a sliding in a cylinder tube, at least one side pressurized piston, a device for reversing of the piston, and with a check valve each on the inlet side and the outlet side the pump, characterized in that the device for reversing the piston (4) has a programmable controller capable of inducing actuation the pressure medium supply with a device that senses the position of the piston (22, 23) cooperates. 2. Pump according to claim 1, characterized in that the control device is designed as an electrical device with a pressure medium supply controlling valve (11) is connected. 3. Pump according to claim 1 or 2, characterized in that the Device for reversing the piston (4) magnetically operated switches (22, 23) which is electrically connected to the programmable control device (11) are. 4. Pump according to claim 3, characterized in that the piston (4) contains at least one magnetic element (24), which with the in the end region of the piston stroke arranged magnetically operated switches (22, 23) cooperates. 5. Pump according to one of claims 1 to 4, characterized in that that the piston position sensing magnetic switch (22, 26) in a tubular Element (8) are arranged which extend through the piston (4) is arranged in the cylinder tube (1) and which one, if any extends out of the cylinder tube at one end. 6. Pump according to claim 5, characterized in that the magnetic switch (22, 23) with their associated electrical lines via which they connect to the programmable control device (11) connected by tubular element (8) are held in place by suitable holding means. 7. Pump according to claim 6, characterized in that the magnetic switch (22, 23) and the associated electrical lines in the rod-like Element (8) are fixed in their position by a cast resin. 8. Pump according to one of claims 1 to 7, characterized in that that the control device (11) has a further magnetic switch (30) which with an element (29) indicating the pump medium level in a container or the like cooperates. 9. Pump according to claim 8, characterized in that the medium level indicating element; a float (29) is arranged on the foot part (3) of the pump is. 10. Pump according to claim 8 or 9, characterized in that the Float arranged in the interior of the tubular foot part (3) is, and that the interior space via openings or passages (31, 32) with the environment connected is. 11. Pump according to one of claims 8 to 10, characterized in that that the float (29) associated magnetic switch (30) in which the magnetic switch (22, 23) carrying tube (8) is arranged, which is for this purpose up in the foot part (3) extends, and that the float (29) is tubular and around the Rod (8) is arranged around; 12. Pump according to one of claims 8 to 11, characterized characterized in that the float is magnetic material, in particular in the form of a Ring magnet. 13. Pump according to one of claims 4 to 12, characterized in that that the piston (4) contains a preferably annular magnetic element (24) which is arranged in the piston (4) around a central passage of the piston (4). 14. Pump according to one of claims 1 to 13, characterized in that that the control device (11) each via a pressure medium line (10 or 47, 47a) is connected to spaces on both sides of the piston (4). 15. Pump according to claim 14, characterized in that the piston (4) is connected to a further piston (49) for common movement, which is designed as a piston for sucking in and dispensing the medium to be pumped. 16. Pump according to claim 15, characterized in that the pump medium piston (49) has a plurality of axial passages (50) on the medium discharge side of the piston (49) can be closed by means of an axially displaceable valve member (51) are.