DE29706074U1 - Dosing pump - Google Patents

Description

ARNE MISSLING Dipi.-mg. PATENT ATTORNEY

-Sf (06 41) 9 74 60-0, 35390 Giessen

7 April 1997
Wed/To 97.032GM

WiWa Wilhelm Wagner GmbH & Co. KG,
Gewerbestrasse 1 - 3, D-35633 Lahnau

Dosing pump

Description:

The invention relates to a metering pump for removing materials from containers, in particular for 2-component systems, which can be driven by an air motor, with a piston arranged in a pump cylinder and movable back and forth by means of a piston rod and with suction and outlet lines connected to the pump cylinder.

These materials are then mixed in a static or dynamic mixer and fed for further use, for example in a spray gun. A piston-cylinder unit serves as the air motor, which is automatically switched over when the respective piston end position is reached, so that an essentially uninterrupted piston rod movement is achieved. This air motor then drives the metering pumps, whereby with the known metering pumps that convey two or more different materials, tipping moments, which have a major influence on the wear of the metering pumps, cannot be avoided. In addition, these known dosing pumps are

Sieve pumps are also expensive to manufacture and have relatively high maintenance costs.

The invention is based on the object of designing a metering pump, in particular a metering pump for the delivery of two or more components, in such a way that it is on the one hand easy to install and thus inexpensive to manufacture, is subject to only little wear and tear and on the other hand is easy to assemble and disassemble.

This object is achieved according to the invention in that a suction and outlet line is connected to each pump cylinder end, that a check valve acting in the same flow direction is provided in each suction and outlet line

is switched on, that the intake lines and outlet lines are connected to each other in the flow direction before and after the check valves and that the air motor with its drive piston is arranged in the axial extension of the piston rod of the metering pump.

In a metering pump designed according to the invention, the piston rod of the pump cylinder is directly connected to the piston rod of the air motor, so that forces from the air motor are introduced into the metering pump without any tilting moment. The housing of the air motor is rigidly connected to the housing of the metering pump, so that the piston rods of the air motor and metering pump are coaxial. The packings are therefore subject to less wear.

Due to this coaxial arrangement of metering pumps and air motor, theoretically any number of metering pumps can be driven by one air motor. In practice, however, this will usually be two or three, whereby when two metering pumps are used, these are connected to both sides of the air motor.

3s. This has the further advantage that the piston

Pump arrangement in a dosing pump can be replaced without having to dismantle the air motor or the other dosing pump. This replacement of pump cylinder and piston is carried out, for example, when they are worn or when other mixing ratios are required.

The design of the dosing pumps using two plates that enclose the pump cylinder allows for an extremely simple

xo earlier construction of the dosing pump is ensured. The connection holes are formed directly in the plates, whereby the check valves are also advantageously attached directly to the plates. The plates themselves are connected to one another by tension rods, so that the exchange of the

is pump cylinder, piston and packing can be reached by dismantling only a few parts.

It is advantageous to arrange the check valves so that they are parallel to one another, whereby the appropriate arrangement of the metering pump unit ensures that the check valves close solely due to gravity. This has the advantage that additional springs etc. are not required.

2β An embodiment of the invention is described below with reference to the drawing, which shows a metering pump unit, partly in section.

The dosing pump unit shown in the drawing is used to convey two material components that are delivered in containers 1, 2. A line 32 is dipped into each of these containers and is divided into two suction lines 3, 4. These suction lines 3, 4 are connected to the dosing pump unit 5.

Each dosing pump unit is made up of two plates 6, 7, which are connected to one another by tension rods 8. A pump cylinder 9 is clamped between the plates 6, 7 and sealed from the plates 6, 7 by means of seals 10. A piston 11 is arranged in the pump cylinder, which has a piston rod 12, 13 on each side.

In the plates 6, 7, holes 14 are formed which connect the intake lines 3, 4 with the interior of the pump cylinder 9. Check valves 15, 16, 17 and 18 are inserted into these holes 14 and are arranged parallel to one another in such a way that the valve balls 19 rest on their valve seat solely due to gravity when the metering pump unit is arranged horizontally. The check valves 15, 16 are assigned to the intake lines 3, 4, while the other check valves 17, 18 are assigned to the output lines 20, 21. These output lines 20, 21 merge into a common line 22 which leads to a mixer (not shown) in which the two material components are mixed together. A paint spray gun, for example, is then connected downstream of the mixer.

The piston rod 12 or 13 of the metering pump 5 is directly connected to the piston rod 23 of an air motor 24. This air motor is formed by two plates 25, 26, between which a cylinder 27 is clamped. The plates 25, 26 are connected to one another by tension rods 28. The plates 21 or 26 of the air motor are rigidly connected to the plates 6, 7 of the metering pump via spacer elements 31.

so 5. The air motor controls itself automatically, i.e. when the respective end position of the piston 29 is reached, a two-way valve 30 is switched accordingly.

The dosing pump works as follows. If the piston 11 is moved to the left from the position shown for 3s,

Material is pumped out of the container 1, 2 via the suction line 3 and the check valve 16. The material in the pump cylinder 9 is pushed out to the left via the bore 14, the check valve 16 into the outlet line 20, 22.

B ben, whereby the check valve 15 prevents the material from flowing back into the container 1. Once the piston 11 has reached the left end position, it is moved in the opposite direction by the air motor 24, whereby material is then drawn out of the

&iacgr;&ogr; container 1, 2. At the same time, the material in the pump cylinder 9 is pressed out via the check valve 18 and the lines 14, whereby the check valve 16 now prevents the material from flowing back into the container 1, 2 and the check valve 17 prevents the material from flowing back into the pump cylinder 9. The two metering pumps 5 work synchronously so that the mixer (not shown) is continuously supplied with the intended quantities of the materials 1, 2.

container ; :: . 6 : : .* container ·« * ·« · ·· Intake line <·· <« Intake line Reference number list Dosing pump 1 plate 2 plate 3 Tension rods 4 Pump cylinder 5 Seals 6 Pistons 7 Piston rod 8th Piston rod 9 Connection hole 10 check valve 11 check valve 12 check valve 13 check valve 14 Valve ball 15 Output line 16 Output line 17 Line 18 Piston rod 19 Air motor 20 plates 21 plates 22 cylinder 23 Tension rods 24 Drive piston 25 Two-way valve 26 Spacer elements 27 Line 28 29 30 31 32

Claims (1)

ARNE MISSLING Dipi.-mg. PATENT ATTORNEY 'S· (06 41) 9 74 60-0, 35390 Giessen 7 April 1997
Wed/To 97.032GM WiWa Wilhelm Wagner GmbH & Co. KG,
Gewerbestrasse 1-3, D-35633 Lahnau Dosing pump Expectations: 1. Dosing pump (5) for removing materials from 2s holders (1, 2), in particular for 2-component systems, which can be driven by an air motor (24), with a piston (11) arranged in a pump cylinder (9) and movable back and forth by means of a piston rod (12, 13) and with suction and outlet lines (3, 4; 20, 21) connected to the pump cylinder (9), characterized in that a suction and outlet line (3, 4; 20, 21) is connected to each pump cylinder end, that a check valve (15, 16; 17, 18) acting in the same flow direction is connected to each suction and outlet line (3, 4; 20, 21) 3s is that the intake lines (3, 4) and outlet lines (20, 21) are connected to each other in the flow direction before and after the check valves (15, 16; 17, 18) and that the air motor (5) with its drive piston (29) is in axial extension of the piston rod (12, 13) of the metering * ϳ pump (5) is arranged. 2 : 2. Dosing pump according to claim 1, characterized in that several dosing pumps (5) are arranged one behind the other in axial alignment, with their piston rods (12, 13) being connected either to the piston rod (23) of the air motor (24) and/or to dosing pumps (5) adjacent to the piston rod (12, 13). 3. Dosing pump according to one of claims 1 or 2, characterized in that the check valves (15, 16; 17, 18) of each dosing pump (5) are arranged parallel to one another in such a way that each check valve (15, 16; 17, 18) can be closed automatically solely due to gravity. 4. Dosing pump according to one of claims 1 to 3, characterized in that the dosing pump (5) consists of two interconnected plates (6, 7), between which the pump cylinder (9) receiving the piston (11) is clamped and that the connection bores (14) for the suction and outlet lines (3, 4; 20, 21) are formed in the plates (6, 7). 5. Dosing pump according to claim 4, characterized in that the check valves (15, 16; 17, 18) are inserted directly into the connection bores (14) of the plates (6, 7). 6. Dosing pump according to one of claims 1 to 5, characterized in that the plates (6, 7) are connected to one another via tension rods (8) and the pump cylinders (9) are sealed in the plates. 7. Dosing pump according to one of claims 1 to 5, characterized in that an air motor (24) is arranged between two dosing pumps (5).