A VACUUM CONTROL SYSTEM

Abstract: The invention relates to a vacuum control system (1) for controlling the vacuum during milking an animal, which vacuum control system is provided with a vacuum pump (2) with a milk line (3), a pulse line (4) and at least one teat cup (7) connected thereto, as well as a regulator (8) by means of which the vacuum in the system (1) is controlled at a desired vacuum level, characterized in that the regulator (8) comprises a speed regulator, preferably a frequency regulator (9), by means of which the number of revolutions of the vacuum pump (2) is controlled, and/or an electronic valve (12) by means of which air can be admitted to the system (1).

Description: A VACUUM CONTROL SYSTEM The invention relates to a vacuum control system as described in the preamble of claim 1. Such a vacuum control system is known. In the known vacuum control systems the vacuum pump runs at a constant rotational speed of approximately 1,500 revolutions per minute and the regulator comprises a mechanical valve with the aid of which air is admitted to the vacuum control system, so that a desired vacuum level is maintained in the system. If the regulator operates properly, the vacuum level is independent of the air consumption of the teat cup or a pulsator, if any. In that case the vacuum pump always displaces a quantity of air of approximately 400 litres per minute. As a result of this, the vacuum level is maintained within the maximally allowed deviation from the desired value, even in the situation of an open teat cup. If all the teat cups are connected to the teats of an animal to be milked, this means that the greater part of the 400 litres of air per minute flows through the mechanical valve of the regulator. This has the disadvantage that the energy consumption of the vacuum pump is high, because the pump always displaces the maximum quantity of air. The vacuum level further depends on the pump capacity. Another disadvantage is that, if it is desired to guarantee the stability of the vacuum level in the long term, it is necessary to check the mechanical valve regularly, the latter having no calibration point. The invention aims at obviating the above-mentioned drawbacks or at least minimizing same. In accordance with the invention, this is achieved by means of the measures described in claim 1. In this manner it is possible to reduce the number of revolutions of the vacuum pump during milking when the air consumption is very low, as a result of which much energy is saved relative to the known system. Because of the fact that it is possible to choose a higher rotational speed of the pump than in the situation of the existing pump, e.g. 3,600 revolutions per minute, it is further possible still to displace the same quantity of air of 400 litres per minute with a smaller pump. A further advantage of the frequency regulator is that the stability of the vacuum level can be guaranteed in the long term. The frequency regulator further offers the possibility of controlling the vacuum level per animal or per teat. A further advantage is that by means of the electronic valve, which is known per se from the automobile engineering, it is possible to anticipate vacuum fluctuations, because of the fact that the valve comprises a very fast-acting control valve. In this manner a very stable vacuum level can be guaranteed in the situation of suddenly occurring alterations in the system, such as e.g. falling down of a teat cup. According to an inventive feature, a vacuum sensor is connected to the regulator. By means of the vacuum sensor it is possible to activate the frequency regulator on the basis of the vacuum measured. The invention will now be explained in further detail with reference to the accompanying drawing. Figure 1 shows schematically the vacuum control system according to the invention. Figure 1 shows a vacuum control system 1 for controlling the vacuum when milking an animal. The vacuum control system 1 may constitute part of a conventional milking machine or a milking robot. The vacuum control system 1 comprises a vacuum pump 2 with a milk line 3 and a pulse line 4 connected thereto. In the milk line 3 there is included a buffer vessel 5 which, in the present embodiment, is designed as a milk glass. To the buffer vessel 5 there is further connected a non-shown line which is connected to a neither shown milk tank. In the pulse line 4 there is further included a pulsator 6 by means of which an alternating vacuum can be applied in a pulsation room of a teat cup 7. The vacuum control system 1 further comprises a regulator 8 by means of which the vacuum level in the system can be controlled at a desired vacuum level. The regulator 8 comprises a frequency regulator 9 by means of which the number of revolutions of the vacuum pump 2 can be controlled. In the vacuum control system 1 there is further included a vacuum sensor 10 which supplies its signal to the regulator 8. In the regulator 8 there is further included a filter unit 11 for filtering the signal emanating from the vacuum sensor 10. In the vacuum control system 1 there is further included an electronic valve 12 by means of which air can be admitted to the vacuum control system. The electronic valve 12 comprises a non-shown fast-acting control valve, which is known per se from the automobile engineering. The electronic valve 12 is activated by the regulator 8, on the basis of the signals supplied by the vacuum sensor 10. The vacuum sensor 10 and the electronic valve 12 are included in that part of the vacuum line system which is located between the buffer vessel 5 and the vacuum pump 2. In accordance with the invention it is further possible to omit the electronic valve 12 in the above described embodiment. It is also possible only to make use of the electronic valve 12 and consequently to omit the frequency regulator 9.

Claims: CLAIMS 1. A vacuum control system for controlling the vacuum during milking an animal, which vacuum control system is provided with a vacuum pump (2) with a milk line (3), a pulse line (4) and at least one teat cup (7) connected thereto, as well as a regulator (8) by means of which the vacuum in the system (1) is controlled at a desired vacuum level, characterized in that the regulator (8) comprises a speed regulator, preferably a frequency regulator (9), by means of which the number of revolutions of the vacuum pump (2) is controlled, and/or an electronic valve (12) by means of which air can be admitted to the system ( 1 ) . 2. A vacuum control system as claimed in claim 1, characterized in that a vacuum sensor (10) is connected to the regulator (8) . 3. A vacuum control system as claimed in claim 2, characterized in that the regulator (8) comprises a filter unit (11) by means of which the signal emanating from the vacuum sensor (10) is filtered. 4. A vacuum control system as claimed in any one of the preceding claims, characterized in that the electronic valve (12) is connected to the regulator (8). 5. A vacuum control system as claimed in any one of the preceding claims, characterized in that the valve (12) is included in a vacuum line. 6. A vacuum control system as claimed in any one of the preceding claims, characterized in that the system (1) comprises several teat cups (7) and that in the system (1) each of the teat cups (7) has an own valve (12). 7. A vacuum control system as claimed in any one of the preceding claims, characterized in that the system (1) comprises a vacuum buffer vessel (5). 8. A vacuum control system as claimed in any one of the preceding claims, characterized in that the system (1) comprises a pulsator (6) for applying a pulsating vacuum in the teat cup (7). 9. A milking robot for automatically connecting teat cups to an animal to be milked, which milking robot is provided with a vacuum control system as described in any one of claims 1 to 8.

Inventors: OORT DICK MARIUS, OORT, DICK, MARIUS
Applicants: MAASLAND NV, OORT DICK MARIUS, MAASLAND N.V., OORT, DICK, MARIUS
Application year: 2000
Main classification: A01J5
IPC codes: A01J5