Method and device for treating hydraulic fluid

Abstract

A method and apparatus (10) for treating a hydraulic fluid (6) is disclosed. The method has the following steps: detecting (1) a state and exceeding (2) a warning threshold for the state, and replenishing (3) the hydraulic fluid (6) with the additive to be replenished. The device comprises: a sensor device (7) which is designed and designed to detect (1) a state; and a dosing unit (8) which is designed and set up to replenish (3) the additive to be replenished to the hydraulic fluid (6) when a warning threshold value (2) for the state is exceeded.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for treating hydraulic fluid in a hydraulic device. Background Art

[0002] Oil is usually used as the pressure medium or hydraulic fluid in hydraulic systems, which is subject to aging and wear.

[0003] A measuring system for determining oil quality is known from the article “COPS—Combined Oil quality and Particle measurement System” (“COPS—Combined Oil quality and Particle measurement System”, by T. Bley, E. Pignanelli and A. Schütze, in the “6th International Conference on Sensor Technology (ICST) 2012”, starting at page 561). In this case, the oil is guided through a measuring cell and irradiated with, for example, infrared light, wherein the light emitted from the measuring cell is measured by means of a photodiode.

[0004] DE 10 2021 201 017 A1 of the applicant discloses a measuring system with which a plurality of characteristic parameters characterizing the state of a hydraulic fluid can be obtained. These characteristic parameters can then be considered together to draw conclusions about whether the hydraulic fluid can continue to be used. The measuring device is preferably used directly on the hydraulic device or vehicle, for example to decide when a hydraulic fluid needs to be replaced.

[0005] The applicant's DE 10 2019 217 198 A1 discloses a measuring system for condition monitoring of a hydraulic fluid using a measuring device, the measuring device having at least two light sources and at least two receivers, which can be set in different spectral ranges. The measuring device can detect the infrared spectral region and the visible spectral region simultaneously. According to the disclosed method, the hydraulic fluid should be irradiated substantially continuously and the aging state of the hydraulic fluid should be determined.

[0006] US Pat. No. 6,331,704 B1 discloses the detection of dirt particles in hydraulic fluids by means of infrared radiation. This is intended to take place during the continuous operation of the relevant system.

[0007] Furthermore, it is known from the prior art to meter a cleaning agent continuously into the hydraulic fluid by means of a system integrated into the hydraulic system when the purity requirements are high, on which the dirt particles accumulate. Summary of the invention

[0008] The task of the present invention is to further improve the quality or state of the hydraulic fluid. Here, even a temporary deterioration of the hydraulic fluid state should be avoided. In other words, the hydraulic fluid state should always be kept optimal.

[0009] This object is achieved with a method according to claim 1 and a device according to claim 6 and a hydraulic system according to claim 10 .

[0010] The method according to the invention is used for treating a hydraulic fluid and comprises the following steps:

[0011] - continuously or periodically or regularly checking the state (parameters) of the hydraulic fluid, in particular the aging state,

[0012] - a warning threshold for said state (parameter) is exceeded,

[0013] - Adding (dosing) the additive to be replenished to the hydraulic fluid, wherein the steps are carried out in the sequence mentioned and wherein the steps are then carried out again from the beginning.

[0014] The corresponding device according to the invention is used for processing hydraulic fluids and has a sensor system which is designed and configured to continuously or periodically or regularly detect a state (parameter), in particular an aging state, of the hydraulic fluid. The device also has a metering unit which is designed and configured to add (add) an additive to be added to the hydraulic fluid when a warning threshold value for the state is exceeded. Preferably, the aforementioned state is automatically determined, in particular measured or calculated, wherein the determined state is automatically compared with the warning threshold value, wherein, depending on the result of the comparison, i.e., when the determined state exceeds the warning threshold value, the additive to be added is automatically metered into the hydraulic fluid.

[0015] The invention makes it possible to significantly extend the life of the hydraulic fluid in the device (until the service life of the device expires). The advantages arise on the one hand from economic savings, and on the other hand from reduced CO2 emissions of the device due to reduced demand for hydraulic fluid.

[0016] In many applications, the hydraulic fluid is a hydraulic oil or a lubricating oil with at least one existing additive.

[0017] In the method according to the invention, detecting the state of the hydraulic fluid is preferably detecting the proportion of additive present in the hydraulic fluid, wherein exceeding the warning threshold is a critical value below which the proportion of additive present in the hydraulic fluid is below.

[0018] In a corresponding device according to the invention, the sensor device is preferably designed and arranged to detect the proportion of additive present in the hydraulic fluid. Exceeding the warning threshold is a critical value below which the (proportion of) additive present in the hydraulic fluid is exceeded.

[0019] In the method according to the invention and in the device according to the invention, the additive to be replenished is preferably identical to the existing additive.

[0020] In the method according to the invention and in the device according to the invention, the additive to be replenished and the existing additive are preferably antiwear additives. The antiwear additive is preferably zinc dithiophosphate (ZDDP).

[0021] In the method according to the invention, the hydraulic fluid is preferably homogenized after the additive to be supplemented (dosed) into the hydraulic fluid, or the device according to the invention preferably has a homogenization unit for the hydraulic fluid.

[0022] From a plurality of successively detected states (parameters) of the hydraulic fluid, in particular the aging state, the remaining time until replenishment of the additive to be replenished and / or the service life of the hydraulic fluid is or can be determined with the aid of an algorithm.

[0023] In the method according to the invention, a hydraulic fluid preferably circulates in a hydraulic device, for example in a hydraulic drive, wherein the three to five steps mentioned are carried out continuously or periodically or regularly during operation of the hydraulic device.

[0024] The device according to the invention is preferably further developed into a hydraulic device (eg a hydraulic drive), wherein the device can be operated during operation of the hydraulic device. For this purpose, the device is preferably connected to a closed circuit or an open circuit of the hydraulic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments of the present disclosure are described below based on related drawings.

[0026] Figure 1 A flowchart for illustrating an embodiment of a method according to the present disclosure is shown; and

[0027] Figure 2 A hydraulic device having a device according to the disclosure is shown. DETAILED DESCRIPTION

[0028] The invention is based on a control circuit for regularly monitoring 1 the health of a hydraulic fluid in a hydraulic device (eg a crane, a transmission, a machine such as a motor, etc.). Figure 1When the state of the hydraulic fluid reaches 2 a critical value, an additive is added 3 by the metering unit so that the properties of the original state of the hydraulic fluid and thus the properties of the hydraulic device are restored or even improved.

[0029] Here, the hydraulic fluid is measured instantaneously or at short intervals using suitable sensors. These values ​​are fed into an algorithm that calculates the remaining service life of the hydraulic fluid. The algorithm runs either offline or online as a cloud solution.

[0030] The algorithm determines how much of the quality-determining additive has been consumed by use. If a critical value is below 2, the additive concentrate is metered 3 into the hydraulic system by the metering unit and homogenized.

[0031] In addition, there is the possibility of deliberately changing (regulating) the hydraulic fluid and better adapting it to the respective requirements of the hydraulic system. The invention functions without prior purification of the hydraulic fluid and does not require any additional hydraulic fluid volume during operation of the hydraulic system.

[0032] Figure 2 A hydraulic device 4 is shown which is designed as a hydrostatic drive with an open circuit 5 via which a pump P is connected to a motor M. A hydraulic fluid 6 flows under high pressure from the pump P to the motor M via the open circuit 5. The hydraulic fluid 6 contains at least one known additive 6a.

[0033] The hydraulic system 4 or the open circuit 5 has a tank T. In the region of the tank T, a device 10 is arranged which comprises a sensor system 7 and a metering unit 8 as well as a homogenizing unit 9. The sensor system 7 has a sensor, by means of which the proportion of additive 6a present in the hydraulic fluid 6 is detected. If a warning threshold is exceeded, the metering unit 8 and the homogenizing unit 9 are activated and the added additive is mixed with the hydraulic fluid 6. The sensor system 7 is then activated again at regular time intervals.

[0034] More specifically, the device 10 is used to perform the reference Figure 1 The method of explanation.

[0035] List of reference numerals:

[0036] 1. Detection steps

[0037] 2 Steps beyond

[0038] 3 Dosing steps

[0039] 4 Hydraulic equipment

[0040] 5 Open circuit

[0041] 6 Hydraulic fluid

[0042] 6a Existing additives

[0043] 7 Sensing mechanism

[0044] 8 dosing units

[0045] 9 Homogenization unit

[0046] 10. Installation

[0047] P Pump

[0048] M Motor

[0049] T tank

Claims

1. A method for treating a hydraulic fluid (6), the method comprising the following steps: - continuous or periodic or regular monitoring (1) of the state (parameters), in particular the aging state, of the hydraulic fluid (6), - exceeding (2) the warning threshold for said status, - dosing (3) or adding the additive to be replenished to the hydraulic fluid (6), in, Steps (1, 2, 3) are performed in the order mentioned.

2. The method according to claim 1, wherein: Detecting (1) the state of the hydraulic fluid (6) is detecting the proportion of the additive (6a) present in the hydraulic fluid (6), and wherein exceeding (2) the warning threshold is below a critical value of the proportion of the additive (6a) present in the hydraulic fluid (6).

3. The method according to claim 2, wherein: The additive to be supplemented and the existing additive (6a) are anti-wear additives, in particular zinc dithiophosphate (ZDDP).

4. A method according to any one of the preceding claims, wherein: After the additive to be replenished has been metered (3) or added to the hydraulic fluid (6), the hydraulic fluid (6) is homogenized.

5. A method according to any one of the preceding claims, wherein: The remaining time until the additive to be replenished and / or the service life of the hydraulic fluid (6) is determined by means of an algorithm from a plurality of successively detected states (parameters), in particular aging states, of the hydraulic fluid (6).

6. A device (10) for processing a hydraulic fluid (6), comprising: a sensor device (7), which is constructed and established for continuously or periodically or regularly detecting (1) a state (parameter) of the hydraulic fluid (6), in particular an aging state; and a metering unit (8), which is constructed and established for metering (3) or replenishing an additive to be replenished into the hydraulic fluid (6) when (2) a warning threshold value for the state is exceeded.

7. The device (10) according to claim 6, wherein: The sensor device (7) is constructed and arranged to detect (1) the proportion of the additive (6a) present in the hydraulic fluid (6), and wherein exceeding (2) a warning threshold is below a critical value of the proportion of the additive (6a) present in the hydraulic fluid (6).

8. The device (10) according to claim 6, comprising a homogenization unit (9) for the hydraulic fluid (6).

9. The device (6) according to any one of claims 6 to 8, wherein: By means of an algorithm, the remaining time until activation of the metering unit (8) and / or the service life of the hydraulic fluid (6) can be determined from a plurality of successively detected states (parameters), in particular aging states.

10. A hydraulic system (4) comprising a device (10) according to any one of claims 6 to 9.

11. The hydraulic device (4) according to claim 10, wherein: The device (10) is operable during operation of the hydraulic unit (4).

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