DE3210465A1 - Device for detecting the quantity of milk given by a cow during a milking process - Google Patents

Abstract

A device for detecting the quantity of milk which is given by a cow in the course of a milking process, with a container which can be acted upon by vacuum and in which the milk is first separated from the milk/air mixture given by the cow. Connected to the container is a measuring device which is characterised in that no moving parts come into contact with the milk so that an even milk throughflow and particularly favourable cleaning opportunities are made possible. The measuring device has essentially a calibrated measuring pipe which is connected to the deepest point of the container. Interacting with the measuring pipe is a throughflow measuring device, by which the flow rate of the milk is first detected using measurement techniques and, from this as well as from the other known data of the entire flow arrangement, the required quantity of milk is then calculated.

Description

Device for detecting the amount of a cow in a

Milk dispensed during the milking process The invention relates to a milk measuring device which is used to detect the amount of milk produced by a cow a milking process delivered milk between the milking cluster and during milking the milking line is switched on, with a cylindrical one that can be acted upon by negative pressure Container in which from the delivered by the cow and via a supply line from Milk-air mixture supplied to the milking unit, the milk is separated, and with a measuring device connected to the container.

Such a device is known from DE-OS 30 20 161.

This known device relates to a milk quantity measuring device for milking systems for direct measurement of the amount of milk given off by a cow in the course of milking, with a separating chamber acted upon by a negative pressure for separating the milk from the milked milk-air mixture and with a downstream of the separation chamber Measuring chamber for the milk, which at its lower end has a valve body Has closable milk outlet opening and assigned to a measuring device is. Extends from the separation chamber to a collection chamber or manifold an air duct, which at the same time acts as a slide rail for a swimmer serves as a level indicator for the milk in the measuring chamber is used. The float acts with at least one in the wall of the measuring chamber arranged magnetic sensor together.

This known device has the disadvantage that with the milk moving parts such as valves and / or floats come into contact with the necessary careful cleaning of the entire facility after completion the milking process cause considerable difficulties. Furthermore there is with this known device the disadvantage that the entire device is carefully in a vertical Arrangement must be aligned, otherwise there is a risk that the The float jammed on its guide and thus impaired its proper function will.

The invention is based on the A u f g a b e, a device for Detection of the amount of milk given off by a cow during a milking process To create the type mentioned in more detail at the outset, with which while maintaining good measurement accuracy a particularly reliable function and extremely easy cleaning can be achieved.

According to a preferred embodiment of the subject matter of the invention it is provided that between the container in which the coming from the milking cluster Feed line opens, and the container jacket is provided with an interspace, the one Forms flow cross-section which is larger than the flow cross-section of the milking line is, and that the container has pressure compensation openings in its upper area, through which a connection between the interior of the container and the intermediate space is made between the container and the container jacket. It can also be preferred it can be provided that the pressure compensation opening has a total opening cross-section have, at least together with the flow cross-section of the measuring tube at least is equal to the flow cross-section of the milking line.

The main advantages of the device according to the invention are that practically no moving parts come into contact with the milk the function could lead to malfunctions and during cleaning to difficulties.

Furthermore, according to the invention, a compact, robust, Achieve inexpensive and operationally reliable arrangement that is also below the expected harsh operating conditions maximum reliability and durability to ensure.

It is preferred in terms of being compact yet accurate Measuring device also provided that the measuring tube as a straight pipe socket with circular inner cross-section is formed, which fes attached to the container is.

A particularly advantageous embodiment of the subject matter of the invention provides that the measuring tube is assigned a capacitor with which the dielectric constant the milk flowing through the measuring tube is to be measured, so that the The proportion of air still contained in the milk can be determined because it is known that the Dielectric constants of milk and air are very different. It can however, the detection of air bubbles in the milk inside the measuring tube also optically be done by light scattering by using, for example, a laser.

A very advantageous measurement results from a preferred one Embodiment of the subject matter of the invention in that the flow measuring device is designed as an inductive measuring device that the measuring tube concentrically within a solenoid is arranged, through which with the help of a pulsating direct current A magnetic field is generated perpendicular to the measuring tube axis, whereby the Measuring tube flowing milk a voltage that can be tapped off at electrodes is generated, the Size serves as a measure of the flow rate of the milk through the measuring tube. Included the strength of the magnetic field is preferably about 5000 Gauss.

In an alternative advantageous development of the invention can be provided that the flow measuring device as an ultrasonic measuring device is designed in which the ultrasonic beam directed obliquely into the measuring tube Frequency change occurring in the milk flow due to the Doppler effect serves as a measure of the flow rate of the milk through the measuring tube.

A particularly simple and at the same time reliable arrangement results in an alternative embodiment also in that the measuring device on two opposite areas of the wall of the container electrical Has electrodes through which to capacitively determine the fill level of the milk in the container is, whereby with a known fill level and calibrated flow cross-section of the measuring tube the flow is to be determined.

It can preferably be provided that the electrodes have a metal coating the container wall are formed.

As generally for control purposes the filling of a milk sample is desired, an advantageous development of the invention provides that below the mouth of the measuring tube opens the opening of a catch tube, in which a milk sample taken from the milk stream continuously emerging from the measuring tube is conveyed via a pump into a milk sample bottle. Here is the arrangement advantageously made such that the pump is designed as a hose pump is.

Another advantageous development of the subject matter of the invention provides that the pump in dependence on that specifiable milking phase which the milk sample is taken within the entire milking process, such it is controllable that an amount of milk is taken as a sample which is proportional to the current one occurring in the milking line at the time the sample was taken Milk flow is. The arrangement is preferably made such that the Operating time of the pump for volume-proportional dosing of the milk sample as a function the respective filling rod height in the container is controllable. In this way, the The advantage achieved is that the sample milk has essentially the same composition how the milk actually totaled from a single milk shows.

Furthermore, it can preferably be provided that at the free end a hose valve is attached to the measuring line and the hose valve through an electromagnet can be actuated.

A preferred embodiment is characterized in that the electromagnet can be controlled at a predeterminable level in the container is. In this way, difficulties can be elegantly eliminated can be caused by the fact that at the beginning of a milking process in particular there are many air bubbles in the milk and that in the beginning still very much low level in the container may affect the accuracy of the measurement can be.

Another advantageous development of the subject matter of the invention provides that a time recording device is provided with which during of a milking process, the time span between the inflow of the first milk the supply line in the container or in the measuring tube and the drainage of the last Milk can be determined and registered from the measuring tube. With such an arrangement the advantageous possibility is created that the so-called milkability is recorded can be. In this way it can be determined in what time the milking process is finished.

Overall, according to the invention, there is an advantageous measuring device created, which is characterized in particular by the fact that of the entire measuring device only a calibrated measuring tube comes into contact with the flowing milk, in which no flow obstacles are arranged, so that with good measurement accuracy a smooth milk flow is made possible and an easy cleaning of the whole Device is possible.

The invention is explained below, for example, with reference to the drawing described; 1 shows a schematic vertical section through a milk quantity measuring device, Fig. 2 is a corresponding representation of a particularly preferred embodiment of the milk quantity measuring device, FIG. 3 shows a corresponding one Representation of an advantageous development of the milk quantity measuring device and Fig. 4 is a graphic representation in which for a single milk the flow is shown as a function of time.

According to the illustration in the drawing opens into a substantially cylindrical container 12 a milk supply line 14, through which incoming milk from the cluster Milk is guided tangentially against the wall of the container 12. More precisely, it a milk-air mixture comes from the milking cluster, from which the milk is separated, by the mixture flowing in through the supply line 14 at a sufficient speed is directed tangentially against the container wall. The container 12 is in the form of a upright cylinder with a diameter of about 100 mm and a height of about 250 mm. In its lower area, the container 12 has a base 17 in the form of a cone shell. At the deepest point of the bottom 17 is a Measuring tube 15 connected to container 12. As shown in the drawing the measuring tube 15 is designed as a pipe socket with a length of about 60 mm. This pipe socket has a calibrated inner diameter, so that a defined Flow cross-section is present. The lower free end of the measuring tube 15 opens into a space which is arranged inside a container jacket 13. In this Container jacket 13, the entire container 12 is inserted, and between the container jacket 13 and the container 12, a seal 22 is attached in the region of the upper edges. In addition, there are pressure compensation openings between the container 12 and the container jacket 13 26 arranged.

The space arranged in the lower region of the container jacket 13, in which the measuring tube 15 opens, has a suction line 11 which is connected to a vacuum line can be connected.

The milk flows through the calibrated measuring tube 15 into the lower area of the container jacket 13 and is sucked off via the vacuum.

When passing through the measuring tube 5, the flow rate is the Milk measured, and it can then because of the known flow cross-section of the Measuring tube 15, the amount of milk can be determined. It can namely with the schematic flow measuring device shown at 16 from the measured flow velocity and the required amount of milk can be calculated from the otherwise known flow data.

In the arrangement shown in the drawing, the measuring tube 15 surrounded by a magnetic coil 18. It becomes vertical with the help of this magnetic coil 18 generated to the axis of the measuring tube 15, a magnetic field of about 5000 Gauss, namely by a pulsating direct current. When the milk is flowing, then in the measuring tube 15 a Voltage that can be tapped off by electrodes is generated, the magnitude of which is a measure of the flow rate the milk is through the measuring tube 15. In this way, measuring accuracies in the order of 1%.

Below the mouth of the measuring tube 15, a catch tube 19 is shown, with which from the milk jet emerging from the measuring tube 15 a milk sample can be taken. Since there is a vacuum within the container jacket 13, must the milk must be forcibly removed. This is done as shown in the drawing with the aid of a pump 20 designed as a hose pump, with which the milk sample is conveyed into a milk sample bottle 21.

Except for the measurement method shown purely schematically in the drawing some other type of flow measurement can be used, and even any other method can be used in which there are no disruptive internals must be made in the measuring tube 15. For example, it could be an ultrasound beam sufficiently high frequency are directed obliquely into the measuring tube 15 to reduce the flow rate to investigate. When the milk or other liquid in the tube stand still a signal with that frequency could be sent to an ultrasonic receiver received, which is also emitted by an ultrasonic transmitter. If the Milk, however, flowing at sufficient speed changes at the recipient the frequency through the Doppler effect. This change in frequency is a measure of that Flow rate.

With the assumed defined inside diameter of the measuring tube in an alternative embodiment, the amount of milk can also be determined if at the same time the level in the container 12 is detected. It is known that in principle by timing the data assumed to be known here, the amount can be calculated. About the filling level, i.e. the level of the milk in the container 12 To determine, the container 12 could be provided with a metal coating be that two opposing electrodes are formed. Through the relatively large dielectric constant of the milk can be the filling height convert into a capacitance and thus also into a voltage or current change, so that in this way the flow through the measuring tube 15 at certain time intervals can be determined and in this way the amount of milk that has passed through the measuring tube could be calculated.

The one described above and shown schematically in the drawing Device according to the invention also has the considerable advantage that therefore hardly any vacuum losses occur because the cross-sections of the supply line 14 up to the measuring tube 15 can be kept practically constant.

The difference in diameter between the container 12 on the one hand and the container jacket 13 on the other hand is chosen so that a sufficient Flow cross-section is guaranteed, so that pressure losses between the suction line 11 and the supply line 14 practically do not occur. This is for practical use of great importance because in this way pressure losses or repercussions on the milking cluster can be avoided.

The milk coming from the milking cluster and flowing into the container 12 is heavily enriched with air bubbles. Although these are largely released, by the tangential flow into the container; however, there remains a residue back to air. This air flows through the measuring tube 15 and falsifies the measurement. Therefore, according to the invention, the influence of the air on the measurement result is taken into account. As shown in FIG. 2, a capacitor is located outside the measuring tube 15 23, the pads 23a and 23b of which are attached along the circumference of the measuring tube 15 are. The capacity of this capacitor is determined by the area of the pads, the distance of the pads from each other and the dielectric arranged between the pads is determined. For water, the dielectric constant has a value of about 80, while it for air only has the much lower value of 1. So if a measurement signal it is determined which of the setpoint signal given for water or milk is worth mentioning deviates, this deviation is due to the influence of air. You can also imagine that the trapped air bubbles are concentrated in a thin layer and thus the dielectric would not be the entire space between the capacitor plates fills, whereby the capacitance of the capacitor decreases.

It should be noted, however, that instead of capacitive detection the proportion of air in the milk, a corresponding detection of air bubbles also optically could be done. Using a laser device, for example the light emission caused by air is used to verify the air content will. Such an optical device would be equivalent to the capacitive measuring device.

Basically, the level in the container 12 is constant fluctuations subject, since the milk flow coming from the milking cluster also fluctuates accordingly is exposed. If the container 12 according to the above explanations with capacitor plates fitted is, the capacitor formed in this way is dependent on the level changed in size, and the derived signal can be used in a computing device processed in such a way that the milk actually flowing out in the meantime is calculated.

Certain problems may arise due to the fact that to At the beginning of a milking process, there is a particularly large amount of air in the milk. Farther The accuracy of the measurement can also be impaired as a result be that at the beginning of the milking process, the level in the container 12 is still very high is low. It is therefore useful to have an in at the free end of the measuring tube 15 3 to attach the hose valve 24 shown schematically, which via to actuate an electromagnet also shown schematically in FIG. 3 is. By such an arrangement, the hose can be compressed so that in this way the milk flow through the measuring tube 15 can be interrupted. With such an arrangement, with a predeterminable fill level in the container 12, the hose valve 24 can be opened so that the milk can then run out. The amount of milk that runs out as a function of time can be seen in itself determine in a known manner.

The pump 20 already mentioned with reference to FIG. 1 has also already explained purpose nor the task, the milk sample taken during the milking process to be dosed in a suitable manner. In Fig. 4 is a diagram of the flow Q of the milk during the milking process as a function of the milking time t in the form of a Curve shown. It must also be taken into account that the milked in the time interval a Milk has a different fat content than the milk milked in time interval b.

When the pump 20 runs continuously or in proportion to time for sampling is clocked, then the same amount of milk comes from the time interval a into the Sample bottle as with a sampling in the time interval b. As a result, however, the sample milk is not of the same composition as the total milk milked during a milking process. According to the invention is therefore it is provided that the pump 20 is clocked proportionally to the amount. It becomes through it to take a sample, a quantity of milk obtained in a dose such that this sample quantity of milk is normalized to the curve shown in FIG. As a criterion for the quantity proportional Control of the pump 20, the fill level in the container 12 can be used. Despite certain fluctuations, this fill level is accurate enough proportional to the current flow. With the arrangement described with reference to FIG it is thus possible to ensure when taking the milk sample that the Milk sample has essentially the same composition as the total amount of milk of the Has single milking.

Finally, according to the invention, the so-called milkability can also be used capture. The milkability provides information about the time within which the entire milking process of a single milk can be carried out. According to the Invention can be determined when the first milk in the condenser 23 of the measuring tube 12 arrives and when the last milk leaves this condenser. The one from a corresponding The time determined by the time recording device can be expediently provided Data processing device, which can also be referred to as a computer, in evaluated in the desired way and output in the form of a suitable representation will.

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Claims (17)

Claims 1. Milk measuring device which is used to detect the Amount of milk given off by a cow during a milking process during milking is switched on between the milking cluster and the milking line, with a through negative pressure loadable cylindrical container in which from the delivered by the cow and the milk is separated off via a supply line from the milk-air mixture supplied by the milking machine is, and with a measuring device connected to the container, thereby g e k e n n -z e i c h n e t that at the lowest point of the container (12) a measuring tube (15) is connected with a calibrated flow cross-section, which is essentially is directed straight down and opens with its free end into a room, between the container (12) and a container jacket surrounding the container at a distance (13) is formed that the container jacket (13) is connected to a suction line (11) is, and that a flow measuring device arranged outside the measuring tube (15) (16) is provided with which the milk flow in that of any internals or obstacles free measuring tube (15) is to be determined. 2. Apparatus according to claim 1, characterized in that g e k e n n z e i c h -n e t that between the container (12) in which the supply line coming from the milking cluster (14) opens, and the container jacket (13) is provided with an intermediate space. is the one Forms flow cross-section which is larger than the flow cross-section of the milking line is, and that the container (12) in its upper region pressure compensation openings (26), through which a connection between the interior of the container (12) and the space between the container (12) and the container jacket (13) is made. 3. Apparatus according to claim 2, characterized in that g e k e n n z e i c h -n e t that the pressure equalization opening (26) have an overall opening cross-section, at least together with the flow cross-section of the measuring tube (15) is at least equal to the flow cross-section of the milking line. 4. Device according to one of claims 1 to 3, characterized g e -k e It is noted that the measuring tube (15) is a straight pipe socket with circular ones Internal cross-section is formed, which is firmly attached to the container (12). 5. Device according to one of claims 1 to 3, characterized g e -k e n n z e i c h n e t that the measuring tube (15) is assigned a capacitor (23), with which is the dielectric constant of the flowing through the measuring tube (15) Milk is to be measured. 6. Device according to one of the preceding claims, characterized in that g e k e n n n n z e i c h n e t that the flow measuring device (16) as an inductive measuring device is designed that the measuring tube (15) concentrically within a magnetic coil (18) is arranged through which with the help of a pulsating direct current perpendicular a magnetic field is generated to the measuring tube axis, whereby through the measuring tube (15) flowing milk generates a voltage that can be tapped off at electrodes, the magnitude of which is generated serves as a measure of the flow rate of the milk through the measuring tube (15). 7. Apparatus according to claim 6, characterized in that g e k e n n z e i c h -n e t that the strength of the magnetic field is about 5000 Gauss. 8. Device according to one of claims 1 to 5, characterized g e -k e n n z e i c h n e t that the flow measuring device as an ultrasonic measuring device is designed in which the ultrasonic beam directed obliquely into the measuring tube Frequency change occurring in the milk flow due to the Doppler effect serves as a measure of the flow rate of the milk through the measuring tube. 9. Device according to one of claims 1 to 5, characterized in that g e -k e n n z e i c h n e t that the measuring device is arranged on two opposite one another Areas of the wall of the container (12) having electrical electrodes through the capacitive to determine the fill level of the milk in the container (12), whereby with known fill level and calibrated flow cross-section of the measuring tube (15) the flow is to be determined. 10. The device according to claim 9, characterized in that there is a g etk e n n z e i c hn e t that the electrodes are designed as a metal coating of the container wall. 11. Device according to one of the preceding claims, characterized it is noted that the opening is below the mouth of the measuring tube (15) a catch tube (19) opens, in which one from the continuously from the Measuring tube (15) exiting milk stream, milk sample taken by a pump (20) is conveyed into a milk sample bottle (21). 12. Apparatus according to claim 11, characterized in that it is e k e n n z e i c hn e t that the pump (20) is designed as a hose pump. 13. Device according to one of claims 11 and 12, characterized g e k It is indicated that the pump (20) can be predetermined as a function of that Milking phase in which the milk sample is taken during the entire milking process is, is controllable in such a way that a sample of milk is taken which is proportional at the moment occurring in the milking line at the time the sample was taken Milk flow is. 14. The device according to claim 13, characterized in that g e k e n n z e i c h -n e t that the operating time of the pump (20) for the quantity-proportional metering of the Milk sample can be controlled as a function of the respective filling level in the container (12) is. 15. Device according to one of the preceding claims, characterized in that g e k It is noted that there is a hose valve at the free end of the measuring line (15) (24) is attached and that the hose valve (24) by an electromagnet (25) can be actuated. 16. The device according to claim 15, characterized in that it g e k e n n z e i c h -n e t that the electromagnet (25) at a predeterminable level in the container (12) is controllable. 17. Device according to one of the preceding claims, characterized in that g e k It is noted that a time recording device is provided with which during a milking process, the time span between the inflow of the first milk from the supply line (14) into the container (12) or into the measuring tube (15) and the outflow the last milk from the measuring tube (15) can be determined and registered.