DE102021205173B3 - Method for determining an air quantity, method for filling a hydraulic door closer and measuring device for carrying out the method for determining an air quantity - Google Patents

Abstract

A method for determining an air quantity of air present in a chamber of a hydraulic door closer comprises the following steps: establishing a reference air space with variable volume, which at least includes the air present in the chamber of the hydraulic door closer, determining an initial air pressure in the reference air space, reducing the volume of the reference air space until a predetermined target air pressure is reached in the reference air space,determining a volume difference between an initial volume, which corresponds to the volume of the reference air space before reduction, and a final volume, which corresponds to the volume of the reference air space after reduction, anddetermining the amount of air in the chamber Based on the starting air pressure, the target air pressure and the volume difference.

Description

The invention relates to a method for determining an air quantity of air present in a chamber of a hydraulic door closer, a method for filling a hydraulic door closer and a measuring device for carrying out the method for determining an air quantity of air present in a chamber of a hydraulic door closer.

In order to ensure the functional reliability of hydraulic door closers, they must contain a precisely defined amount of air. Too little air leads to leaks when the temperature rises, whereas too much air can lead to functional failures, also because hydraulic door closers usually do not have an expansion tank.

However, due to component tolerances, the amount of oil required to achieve the exact amount of air is unknown and differs from door closer to door closer. The precise filling of the door closer with oil in order to achieve the exact amount of air is therefore extremely difficult in practice and often cannot be accomplished with sufficient accuracy.

WO 2017/008 853 A1 discloses a method for determining an amount of air in a limited volume, in which a previously known amount of liquid is supplied and a resulting changed air pressure is then measured. The amount of air in the volume is then determined from this. From the DE 10 2020 001 473 A1 a method for filling a hydraulic system of a motor vehicle is known.

It is an object of the present invention to achieve high functional reliability of a door closer.

This object is solved by the subject matter of the independent claims. Advantageous developments are the subject matter of the dependent claims and specified in the description and the drawing.

• Festlegen eines Referenzluftraums mit veränderbarem Volumen, welcher zumindest die in der Kammer des hydraulischen Türschließers vorhandene Luft einschließt,
• Ermitteln eines Ausgangsluftdrucks in dem Referenzluftraum,
• Verkleinern des Volumens des Referenzluftraums bis zum Erreichen eines vorbestimmten Zielluftdrucks in dem Referenzluftraum,
• Ermitteln einer Volumendifferenz zwischen einem Ausgangsvolumen, das dem Volumen des Referenzluftraums vor dem Verkleinern entspricht, und einem Endvolumen, das dem Volumen des Referenzluftraums nach dem Verkleinern entspricht, und
• Ermitteln der Luftmenge in der Kammer auf Basis des Ausgangsluftdrucks, des Zielluftdrucks und der Volumendifferenz.

The method according to the invention serves to determine an air quantity of air present in a chamber of a hydraulic door closer and comprises the following steps:

• Establishing a reference air space with variable volume, which includes at least the air present in the chamber of the hydraulic door closer,
• determining an initial air pressure in the reference air space,
• reducing the volume of the reference air space until a predetermined target air pressure is reached in the reference air space,
• determining a volume difference between an initial volume, which corresponds to the volume of the reference air space before the reduction, and a final volume, which corresponds to the volume of the reference air space after the reduction, and
• Determine the amount of air in the chamber based on the starting air pressure, the target air pressure and the difference in volume.

In the context of this application, a reference air space is understood to be a space which encloses at least all of the air contained in the chamber. In particular, the reference air space can be defined in such a way that it corresponds exactly to the space in which all the air contained in the chamber is located. The reference air space can, for example, correspond to the interior of the chamber when the chamber has not yet been filled with oil, since in this case the air is distributed throughout the chamber. If there is already oil in the chamber, it makes sense to define the reference air space in such a way that it corresponds to the proportion of the interior in which the air is in the chamber. The reference air space can consequently be delimited in whole or in part by walls, for example by the inner walls of the chamber, or by a hydraulic fluid, in particular oil.

After the initial air pressure in the reference air space has been determined, for example using a manometer, the reference air space is reduced. According to Boyle-Mariotte's law, the pressure of ideal gases is inversely proportional to the volume for isothermal changes of state and constant amount of substance. The reduction in the volume of the reference air space consequently results in an inversely proportional increase in the pressure in the reference air space.

The volume of the reference air space is reduced until the predetermined target air pressure has been reached. The volume difference is then determined, ie the amount by which the volume had to be reduced in order to achieve the increase in air pressure from the initial air pressure to the target air pressure.

Finally, knowing the initial air pressure, the target air pressure and the difference in volume, the amount of air in the chamber can be determined, for example, using the Boyle-Mariotte law: $$p\cdot V=cOnst$$

For example, if the target air pressure is twice the initial air pressure, it can be concluded that the volume has halved. The difference in volume therefore corresponds to half the amount of air, or the amount of air in the chamber corresponds to twice the difference in volume.

With this method, the amount of air in the chamber can be reliably determined, which in turn is the basis for then being able to set the exact amount of air, for example by adding oil if there is too much air in the chamber or by removing oil, when there is not enough air in the chamber. The method thus makes it possible to increase the functional reliability of the door closer.

The volume of the reference air space can be reduced, for example, by filling a hydraulic fluid, in particular oil, into the chamber of the door closer or by displacing a piston within the chamber. The hydraulic fluid or the piston can reduce the space available for the air, and thus the reference air space. The air in the reference air space is compressed and the air pressure increases. Filling in a hydraulic fluid can be particularly advantageous since the volume of the hydraulic fluid that is filled in corresponds to the difference in volume. If a piston is used, the difference in volume can be calculated from the displacement of the piston and the cross-sectional area of the reference air space.

• Anschließen der Messvorrichtung, die eine Zusatzkammer mit einer Druckmessvorrichtung, insbesondere einem Manometer, und eine mit der Zusatzkammer verbundene Fluidleitung aufweist, an den Türschließer derart, dass die Fluidleitung die Zusatzkammer mit der Kammer des hydraulischen Türschließers verbindet.
• Dabei wird der Referenzluftraum derart festgelegt, dass dieser ferner die in der Zusatzkammer vorhandene Luft einschließt. Das Ermitteln der Luftmenge in der Kammer erfolgt durch das Ermitteln der Differenz zwischen einer Gesamtluftmenge des Referenzluftraums und einer Teilluftmenge in der Zusatzkammer.

The method is carried out using a separate measuring device that is not part of the door closer, the method additionally comprising the following step:

• Connecting the measuring device, which has an additional chamber with a pressure measuring device, in particular a manometer, and a fluid line connected to the additional chamber, to the door closer such that the fluid line connects the additional chamber to the chamber of the hydraulic door closer.
• The reference air space is defined in such a way that it also includes the air present in the additional chamber. The air quantity in the chamber is determined by determining the difference between a total air quantity of the reference air space and a partial air quantity in the additional chamber.

The use of the measuring device is particularly useful in order to obtain a possibility of determining the air pressure. For this purpose, the measuring device is provided with the pressure measuring device.

When the method is carried out with the measuring device, the total amount of air in the reference air space is determined, analogously to the process described above. For example, the reference airspace may correspond to the space within the chamber plus the space within the auxiliary chamber. The fluid line can be neglected as an approximation. By reducing the volume of the reference air space and thereby increasing the air pressure up to the target air pressure, the total amount of air in the reference air space can be determined, in this example the total amount of air in the additional chamber and in the chamber, knowing the initial air pressure, the target air pressure and the volume difference.

The amount of air in the chamber can then be determined by subtracting the partial amount of air in the additional chamber from the total amount of air. The partial amount of air in the additional chamber can be determined, for example, if the fluid line has a valve for opening and closing the fluid line. The partial amount of air is then determined by closing the valve in order to close the fluid line, determining an initial air pressure in the additional chamber, reducing the volume of the additional chamber until a predetermined target air pressure is reached in the additional chamber, determining a volume difference between an initial additional volume which corresponds to the volume of the auxiliary chamber before contraction, and a final auxiliary volume corresponding to the volume of the auxiliary chamber after contraction, and determining the amount of air in the auxiliary chamber based on the starting air pressure, the target air pressure and the difference in volume.

The additional chamber can be provided with a movable piston, the volume of the additional chamber being reduced by moving the piston within the additional chamber, for example by means of a lifting spindle, or by filling the additional chamber with hydraulic fluid. The piston makes it possible, for example, to calculate the difference in volume from the displacement path of the piston and the cross section of the additional chamber.

• Vorbefüllen des Türschließers mit Öl,
• Ermitteln der Luftmenge in der Kammer des hydraulischen Türschließers durch das zuvor beschriebene Verfahren und
• Nachfüllen von Öl in den Türschließer oder Entnehmen von Öl aus dem Türschließer, um eine gewünschte Luftmenge in der Kammer zu erreichen.

The method according to the invention for filling a hydraulic door closer has the following steps:

• Pre-filling the door closer with oil,
• Determining the amount of air in the chamber of the hydraulic door closer by the method previously described and
• Adding oil to the door closer or removing oil from the door closer to achieve a desired amount of air in the chamber.

The hydraulic door closer can thus be filled precisely based on the previously described method for determining the amount of air, which leads to improved functional reliability of the door closer.

The measuring device according to the invention is used to carry out the above-described method for determining an air quantity of air present in a chamber of a hydraulic door closer and has an additional chamber with a pressure measuring device, in particular a manometer, a movable piston arranged in the additional chamber, a fluid line connected to the additional chamber for fluidly connecting the auxiliary chamber to a chamber of a hydraulic door closer and a valve for opening and closing the fluid line.

The invention is explained below using an exemplary embodiment. thereby illustrated 1 the exemplary embodiment is schematic and shows a chamber of a hydraulic door closer and a measuring device.

1 shows a chamber 10, shown abstractly as a cylinder, of a hydraulic door closer, not shown in detail. Furthermore shows 1 a measuring device 20, which has an additional chamber 21 with a pressure measuring device 23 designed as a manometer in the present example, a movable piston 29 arranged in the additional chamber 21, a fluid line 27 connected to the additional chamber 21, and a valve 25 in the fluid line 27. When the valve 25 is open, the additional chamber 21 and the chamber 10 are connected to one another in a fluid-conducting manner by means of the fluid line 27 .

In order to determine the amount of air in the chamber 10, several steps can be taken. For example, the amount of air in the additional chamber 21 can be determined first. For this purpose, the valve 25 is first closed so that the fluid line 27 is closed and there is no fluid-conducting connection between the additional chamber 21 and the chamber 10 .

An initial air pressure in the additional chamber 21 is then determined by means of the manometer 23 . The piston 29 is then displaced within the additional chamber 21 in order to reduce the volume within the additional chamber 21 which is available for the air. The reduction in volume results in an increase in the air pressure in the auxiliary chamber 21. Once a predetermined target air pressure in the auxiliary chamber 21 is reached, a volume difference between an initial auxiliary volume, which corresponds to the volume of the auxiliary chamber 21 before the reduction, and a final auxiliary volume, which corresponds to the volume of the auxiliary chamber 21 after the reduction can be determined, for example, on the basis of the displacement distance of the piston 29 within the auxiliary chamber 21 and the cross-sectional area of the auxiliary chamber 21.

Finally, knowing the initial air pressure, the target air pressure and the difference in volume, the amount of air in the auxiliary chamber 21 can be calculated, for example by Boyle-Mariotte's law. For example, if the target air pressure is twice the initial air pressure, it can be concluded that the volume has halved. The difference in volume therefore corresponds to half the amount of air, or the amount of air in the additional chamber 21 corresponds to twice the difference in volume.

In a further step, the total amount of air in the chamber 10 and in the additional chamber 21 can then be determined. This takes place with the valve 25 open, so that the additional chamber 21 and the chamber 10 are fluidly connected to one another.

A reference airspace is established. It makes sense to define the reference air space in the present example in such a way that it corresponds to the space inside the chamber 10 plus the space inside the additional chamber 21 . For the sake of simplicity, the volume within the fluid line 27 is neglected.

An initial air pressure in the reference air space is determined by means of the manometer 23 . The piston 29 is then displaced within the additional chamber 21 in order to reduce the reference air space until the air pressure measured on the manometer 23 corresponds to a predetermined target air pressure. Now, a volume difference between an initial volume, which corresponds to the volume of the reference air space before contraction, and a final volume, which corresponds to the volume of the reference air space after contraction, can be determined, for example based on the displacement distance of the piston 29 within the auxiliary chamber 21 and the cross-sectional area the additional chamber 21.

With knowledge of the initial air pressure, the target air pressure and the difference in volume, the total amount of air in the entire reference air space can finally be calculated, analogously to the previous one method described by the Boyle-Mariotte law.

Now that the total air volume in the reference air space and the partial air volume in the additional chamber 21 have been determined, the air volume present in the chamber 10 can be determined by forming the difference between the total air volume in the reference air space and the partial air volume in the additional chamber 21.

Knowing the amount of air in the chamber 10, oil can then be added to the door closer or removed from the door closer to obtain the desired amount of air in the chamber 10. The door closer can thus be provided with the exact amount of air, so that a high level of functional reliability of the door closer is achieved.

Reference List

10

chamber

20

measuring device

21

additional chamber

23

pressure gauge

25

Valve

27

fluid line

29

Pistons

Claims (6)

Method for determining an air quantity of air present in a chamber (10) of a hydraulic door closer, the method comprising the following steps: Establishing a reference air space with variable volume, which includes at least the air present in the chamber (10) of the hydraulic door closer, determining an initial air pressure in the reference air space, reducing the volume of the reference air space until a predetermined target air pressure is reached in the reference air space, determining a volume difference between an initial volume that corresponds to the volume of the reference airspace before contraction, and a final volume equal to the volume of the reference airspace after reduction, and Determining the amount of air in the chamber (10) based on the starting air pressure, the target air pressure and the volume difference, wherein a measuring device (20), which has an additional chamber (21) with a pressure measuring device (23), in particular a manometer, and a fluid line (27) connected to the additional chamber (21), is connected to the door closer in such a way that the fluid line ( 27) connects the additional chamber (21) to the chamber (10) of the hydraulic door closer, the reference air space being determined in such a way that it also includes the air present in the additional chamber (21), and the determination of the amount of air in the chamber (10 ) by determining the difference between a total air volume of the reference air space and a partial air volume in the additional chamber (21). procedure after claim 1 , characterized in that the volume of the reference air space is reduced by filling a hydraulic fluid, in particular oil, into the chamber (10) of the door closer or by displacing a piston within the chamber (10). procedure after claim 1 or 2 , characterized in that the fluid line (27) has a valve (25) for opening and closing the fluid line (27), the partial amount of air in the additional chamber (21) also being determined by: closing the valve (25) to the fluid line (27), determining an initial air pressure in the additional chamber (21), reducing the volume of the additional chamber (21) until a predetermined target air pressure is reached in the additional chamber (21), determining a volume difference between an initial additional volume which corresponds to the volume of the additional chamber ( 21) before contraction, and a final additional volume, which corresponds to the volume of the auxiliary chamber (21) after contraction, and determining the amount of air in the auxiliary chamber (21) based on the starting air pressure, the target air pressure and the difference in volume. Procedure according to one of Claims 1 until 3 , characterized in that the additional chamber (21) is provided with a movable piston (29), the reduction in the volume of the additional chamber (21) being achieved by moving the piston (29) within the additional chamber (21), for example by means of a lifting spindle, or by filling a hydraulic fluid into the additional chamber (21). A method for filling a hydraulic door closer, comprising the steps of: pre-filling the door closer with oil, determining the amount of air in the chamber (10) of the hydraulic door closer by the method according to any one of Claims 1 until 4 and adding oil to the door closer or removing oil from the door closer to a to achieve the desired amount of air in the chamber (10). Measuring device (20) for carrying out the method according to one of Claims 1 until 5 , which has an additional chamber (21) with a pressure measuring device (23), in particular a manometer, a movable piston (29) arranged in the additional chamber (21), a fluid line (27) connected to the additional chamber (21) for fluid-conducting connection of the additional chamber ( 21) having a chamber (10) of a hydraulic door closer and a valve (25) for opening and closing the fluid line (27).

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