JPS6050677B2 - liquid dosing device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a metered liquid dispensing device.

This device consists of a piston pump having at least two pistons with a common supply rate which act on a common pump chamber which is closed by an inlet valve and an outlet valve. In certain known dosing devices, the amount of liquid to be dispensed is determined by varying the piston stroke.

The piston is sealed to its cylinder housing by an O-ring seal. Such devices require significant equipment and labor costs to convert the liquid volume. SUMMARY OF THE INVENTION The object of the invention is to provide a dosing device which is simple in construction and allows rapid changes in liquid quantity.

This problem is solved by the present invention as follows.

This means that one or both of the synchronized pistons, which can be operated independently of each other, can be stopped during each working cycle, and the stroke of each piston can be adjusted, with the exception of minor adjustments that may be necessary for scale verification. It is constant for each work cycle. In the dosing device according to the invention, in order to convert a first feed quantity into a second and even subsequent quantity, it is necessary to simply add the second piston and the third piston together with the first piston. It is enough to operate it.

No adjustment is required during conversion. Since all pistons have one common piston chamber, the cost of the valve is
It is no more expensive than a single pump with only one piston. Inasmuch as it is desired that the delivery be carried out only sequentially, the piston stroke of each piston remains constant, except for minor calibration adjustments which may be made. In some embodiments, the stroke volumes of the pistons are mutually equal.

In other embodiments, the stroke volumes of the pistons are different from each other. By selecting the stroke volume of the piston, the delivery volume can be varied epidemiologically by inserting or cutting a single piston. In order to be able to aseptically fill the liquid, in one embodiment of the invention the piston is constructed as a pusher piston with a sealing diaphragm.

This type of piston has certain difficulties in discharging a given amount due to the pressure sensitivity of the diaphragm, and the valve is not operated by negative pressure or overpressure generated by the piston. Therefore, it is appropriate to provide a servo tube control. In one simple version of construction, part of the pump chamber is formed by a pipe section between the supply pipe and the outlet, into which the piston chamber opens.

Next, the present invention will be explained by means of examples shown in the drawings.

Via a filling pipe 1 with a valve 2, the milk reaches a raw material container 3.

Milk is transferred from the container 3 to a supply pipe 5 by a piston and a pump 4.
through which it is delivered to a discharge section 6 for a container 7. The piston pump 4 consists of two ejector pistons 10, 11 housed in one housing 8, 9, respectively.

Each extrusion piston 10, 11 has a diaphragm 12, 13
The inside of the housings 8 and 9 is sealed. Each housing 8 , 9 is connected to a tube section 14 , which tube section is arranged coaxially between the supply tube 5 and the discharge tube 6 . The pipe section 14 can be disconnected from the supply pipe by an inlet valve 15 and from the discharge by an outlet valve 16. both valves 15
, 16 are connected to a common rod 17 through which the valves can be commonly operated by a servo driver 18. The servo driver 18 is constructed as a cylinder-piston unit with a pressure medium. For the independent operation of the pistons 10, 11, two operating parts 19, 20, which are also designed as pressure medium-containing cylinder-piston units, are provided. The operation of this device is as follows.

After start-up, the feed line 5 and the common pump chamber (which consists of the piston chambers 8, 9 and the tube section 14 from valve 15 to valve 16) are filled with milk.

In the illustrated valve configuration position, the valve 16 provided in the discharge part 6 is closed, while the valve 15 leading to the raw material container 3 is open. In this operating position of the valve configuration, the pump chambers 8, 9, 1
4 is filled with milk from the raw material container 3 by the leftward movement of the pistons 10 and 11. When the pump chamber is maximally filled, the valve arrangement is reversed and valve 15 is thus closed.
After a slight dead stroke caused by the deployment spring 21 between the valves 15 and 16, the lower valve 1
6 opens. The operation during the dead stroke (TOtweg) during the switching of the valves 15, 16 ensures that no liquid flows directly from the supply pipe 5 to the outlet 6 during the switching.

By actuating the drive parts 19, 20, the extrusion pistons 10, 11 are moved to the right into the pump chambers, which in each case expel a certain amount of liquid from the pump chambers 8, 9, 14, and the liquid is transferred to the discharge part. It reaches container 7 through . The strokes of both extrusion pistons 10, 11 are constant.

In order to obtain various volumes of discharge liquid, it is necessary to actuate only one piston or both pistons 10, 11. In order to change the amount of liquid to be discharged in stages, it is even better to make the chambers 8 and 9 of different sizes. After the filling process is completed, the servo driving section 1
8 closes and opens valve 16, and again, after some dead stroke, opens valve 15. Fresh milk can thus enter the pump chamber from the raw material container 3. Instead of a diaphragm piston, an O-ring piston or a sleeve piston can be used for non-sterile milk filling.

[Brief explanation of the drawing]

The accompanying drawing is a side view schematically showing one embodiment of an apparatus for carrying out the invention. 1, Filling pipe, 2, Valve, 3, Raw material container, Male piston pump, 5, Supply pipe, 6, Discharge part, 7, Container, 8, 9, Housing, 10, 11, Extrusion piston, 12, 13, Diaphragm , 1 Male pipe part, 15, Inlet valve, 16, Outlet valve, 1
7, rod, 18, servo driving section, 19, 20, driving section.

Claims (1)

Claims: 1. A piston with at least two pistons with a common supply rate that act on a common pump chamber closed by an inlet valve and an outlet valve. In a liquid dosing device consisting of a pump, one or both of the synchronously running pistons 10, 11, which can be operated independently of each other, can be stopped in each working cycle, and each piston 10, 1
A dosing device in which the stroke of 1 is constant for each working cycle, except for minor adjustments that may be necessary for scale verification. 2. The metering device according to claim 1, wherein the stroke volumes of the pistons 10 and 11 are the same. 3. The metering device according to claim 1, wherein the stroke volumes of the pistons 10 and 11 are different from each other. 4. Dosing device according to claim 1, wherein the pistons 10, 11 are designed as extruded pistons with diaphragms 12, 13 as gas-tight members. 5 A part of the pump chamber is formed from a pipe section 14 between the supply pipe 5 and the discharge part 6, in which piston chambers 8, 9 are formed.
5. Dispensing device according to any one of claims 1 to 4, wherein the dosing device is open. 6. The metering device according to any one of claims 1 to 5, wherein the valves 15 and 16 are provided with a servo operating section 18.