KR101659567B1 - Apparatus and Method for detecting leak - Google Patents

Abstract

The present invention includes a diagnosis system including a hydraulic system including a pump and a diagnosis unit, wherein the diagnosis unit calculates a leakage occurrence amount and a leakage amount using the loading time of the hydraulic system in a steady state and the loading time of the hydraulic system in response to occurrence of leakage And more particularly, to a leakage diagnosis apparatus and a leak diagnosis method. Accordingly, it is possible to determine whether the hydraulic system is leaked or leaked by utilizing the normal operating state of the hydraulic system and the loading operation time required when the leak occurs, without a sensor or an additional device in the hydraulic system.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a leak diagnosis apparatus and method. More particularly, the present invention relates to a leak diagnosis apparatus and method for detecting internal leakage and leak amount of the hydraulic system using a current value of an electric motor installed in the hydraulic system, without a sensor or an additional device for detecting internal leakage of the hydraulic system .

In the case of external leakage, the level of the hydraulic tank may be lowered or visually confirmed.

The inventor of the present invention disclosed in Korean Utility Model Application No. 20-2000-0009662 entitled " Device for Detecting Damage to Hydraulic Equipment in a Blast Furnace Loading Device "

As shown in FIG. 1, in the apparatus for detecting damage to a hydraulic equipment of the blast furnace charging device, oil of the hydraulic tank 1 is provided to the corresponding valve by operation of the hydraulic pump, Hydraulic equipment installed in a blast furnace charging device is described.

The apparatus for detecting damage to a hydraulic equipment of the blast furnace charging apparatus is provided with an arithmetic controller for converting the hydraulic current value detected by the differential pressure detector into an oil level and converting the amount of change of the oil level into a rate of change per hour to calculate an oil leak rate, The oil level and the oil leakage rate of the present hydraulic tank are outputted through the screen display unit through the main controller which performs the continuous calculation processing by setting the measurement time to be short in order to increase the accuracy of the measurement data.

However, unlike the external leakage amount, the internal leakage amount is independent of the naked eye or the tank level, and thus the internal leakage amount can not be managed in the hydraulic system.

However, since it is difficult to confirm the leak inside the hydraulic system, it is necessary to use a blue sound bar or the like to check whether leakage occurs in the hydraulic system. However, when the amount of leakage is small, there is almost no sound, so it is almost impossible to check the leak.

When leakage occurs in the interior of the hydraulic system, as the amount of leakage increases, the pressure in the hydraulic system becomes insufficient due to the lack of flow, and normal operation becomes impossible.

In addition, since the leakage amount is changed into thermal energy, the temperature of the fluid is increased to increase the load of the cooler. Therefore, the service life of the oil or the packing is lowered.

Further, since the pump must be operated by the amount of leakage, the power loss and the life of the pump are degraded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a hydraulic control system and a control method thereof, which are capable of detecting a steady state of the hydraulic system and a loading operation time And a leak diagnosis apparatus and method for detecting leakage and leakage of the hydraulic system.

According to a preferred embodiment of the present invention, the above-described problem is solved by providing a hydraulic system including a pump and a diagnosis unit, wherein the diagnosis unit uses the loading time of the hydraulic system in a steady state and the loading time of the hydraulic system in response to occurrence of a leak And a leaking amount and a leaking amount are obtained.

The leakage amount is characterized by being obtained by the following equation.

L = (T2-T1) * P

(L: leak amount, T2: loading time of hydraulic system when leak occurs, T1: loading time of hydraulic system in steady state, P:

Further, the hydraulic system further includes an electric motor for driving the pump, wherein the diagnosis unit includes: a signal detector for detecting a current value of the electric motor; A calculator for calculating a leak amount by calculating a load time of the hydraulic system based on a current value detected from the signal detector; And an output indicator for outputting the leak amount.

The hydraulic system may further include at least one of a valve stand, a relief valve, a pressure switch, a solenoid valve, a non-shock valve, an accumulator, and a check valve.

According to a preferred embodiment of the present invention, the above object can be accomplished by a method for controlling a hydraulic system, comprising: measuring a loading time of a hydraulic system in which a pump is provided; Measuring a loading time of the hydraulic system in response to a leak; Obtaining a leak amount by using a loading time of the hydraulic system in a steady state and a loading time of the hydraulic system in response to a leak; And recognizing the leakage occurrence and the leakage amount.

The leakage amount is characterized by being obtained by the following equation.

L = (T2-T1) * P

(L: leak amount, T2: loading time of hydraulic system when leak occurs, T1: loading time of hydraulic system in steady state, P:

The leak diagnosis apparatus according to a preferred embodiment of the present invention having the above-described structure is characterized in that the leak diagnosis apparatus is provided with a hydraulic system (not shown) for detecting a steady state of the hydraulic system and a loading operation time It is possible to determine whether or not the internal leakage of the fuel gas is leaking.

In addition, it is possible to periodically check the efficiency of the hydraulic system by detecting the internal leakage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a conventional apparatus for detecting damage to a hydraulic equipment of a blast furnace charging apparatus,
2 is a view showing a leak diagnosis apparatus according to a preferred embodiment of the present invention,
3 is a diagram illustrating a leak diagnosis method according to a preferred embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

2, the leak diagnosis apparatus 1 according to an embodiment of the present invention may include a hydraulic system 100 and a diagnosis unit 200. [ Here, the hydraulic system 100 may include a pump 110 and an electric motor 120.

The diagnosis unit 200 can detect the occurrence of a leak and the leakage loss amount by detecting the current value of the electric motor 120. [

In the case of the pump 110 installed in the hydraulic system 100, loading / unloading operation is performed. Accordingly, the current value of the electric motor 120 at the time of loading and unloading the pump 110 is significantly different.

The hydraulic system 100 repeats loading and unloading according to the flow rate of the hydraulic system 100.

If no leak occurs in the hydraulic system 100, the required flow rate is determined in the hydraulic system 100, so that the pressure is maintained so that the loading time and the unloading time are always kept the same.

However, when a leak occurs inside the hydraulic system 100, the flow rate required for the hydraulic system 100 is reduced, so that the pump 110 is driven to adjust the required flow rate in the hydraulic system 100. As a result, the loading time of the hydraulic system 100 becomes longer and the unloading time becomes shorter.

The diagnosis unit 200 detects leakage and leakage based on the current value of the electric motor 120.

The diagnosis unit 200 may include a signal detector 210, a calculator 230, and an output indicator 250, as shown in FIG.

The signal detector 210 detects a current value sent from the electric motor 120.

The computing unit 230 calculates a loading time T1 of the steady-state hydraulic system 100 and a loading time T2 when the leak occurs based on the current value. Then, the leakage amount is calculated using this.

The output indicator 250 recognizes the occurrence of the leak and the amount of leakage to the operator. For example, the output indicator 250 can display a set-up screen, a display screen for displaying whether a leak has occurred and a lease amount, a management screen, and the like using a device such as a display.

The output indicator 250 of the present invention may be a device such as a display, but the present invention is not limited thereto. It is needless to say that the operator can recognize the occurrence of leakage and the amount of leakage through a sound device such as a speaker .

Thereby, the operator can recognize whether or not the leak has occurred and the leak amount by using the leak diagnosis apparatus 1. [0042] Fig.

Hereinafter, the internal components of the hydraulic system 100 will be described in more detail.

The hydraulic system 100 includes a hydraulic pump 110, an electric motor 120, a plurality of valve stands 130, a relief valve 140, a pressure switch 150, a solenoid valve (not shown) 160, a non-shock valve 170, an accumulator 180, and a check valve 190, and the like. Each of the components installed in the hydraulic system 100 may be connected by a pipe 300 or the like. Here, the valve stand 130 may be a valve module in which various valves are installed.

Loading / unloading of the hydraulic system 100 may be performed in accordance with a preset pressure (for example, 195 to 210 bar) of the pressure switch 150 so that the relief valve 140 is in a loading / unloading state Thereby being driven in an energy saving operation mode.

That is, when the pressure is less than 195 bar, the pressure switch 150 sends a signal to the solenoid valve 160 to be in the loading state. When the pressure reaches 210 bar, the pressure switch 150 returns to the solenoid valve 160 Sends a signal (Off) to the Unloading state.

In the loading state, a signal is applied to the solenoid valve 160 in a situation where the hydraulic system 100 works to supply a flow rate to an actuator such as a cylinder (not shown) . That is, the relief valve 140 functions at a predetermined set pressure.

Accordingly, a large amount of current flows through the electric motor 120 as the pump 110 is driven.

At this time, a non-shock valve 170 may be installed between the relief valve 140 and the solenoid valve 160. Here, the non-shock valve 170 slows down the flow rate of the relief valve 140 at the time of loading / unloading, thereby reducing the switching shock.

Then, when the cylinder stops operating, the pressure of the hydraulic system 100 is increased. When the pressure reaches the predetermined pressure, the pressure switch 150 is in the unloading state. Then, when the pressure of the hydraulic system 100 drops due to the work of the cylinder, the leakage, or the like again, the state becomes a loading state.

Taken together, in a case of a normal hydraulic system 100 in which no leak occurs, since a necessary flow rate is determined in an actuator such as a cylinder, the time taken for loading the hydraulic system 100 is always the same.

Further, after completion of the operation, the pressure rises and the pressure switch 150 switches to unloading. If there is no leak, the pressure is maintained, and this state is maintained until the cylinder is operated again.

That is, the time required for loading and unloading in the hydraulic system 100 (precisely, a system in which the cylinder operation is fixed periodically) is always the same.

However, if leakage occurs, a part of the flow rate to the cylinder is lost, so that the pump 110 must be operated more by the lost flow rate, so that the loading time is lengthened, and even when unloading, The pump 110 must be operated even if the cylinder is not operated because the pressure is reduced.

At this time, the leakage amount can be obtained by multiplying the flow rate of the predetermined pump 110 by measuring the time of additional loading according to occurrence of leakage.

In other words,

(Lpm, L) = [Current loading time (min, T2) - Loading time in normal condition (min, T1)] * Pump flow rate (lpm, P)

.

Therefore, the current loading time at the occurrence of the leak means the loading time according to the occurrence of the leak, and the leakage amount can be obtained accordingly. The occurrence of the leak amount is a factor that can recognize that the leak has occurred in the hydraulic system 100. [

That is, the leak diagnosis apparatus 1 utilizes the fact that the loading and unloading times are always constant in a normal hydraulic system 100 without leakage. The leakage diagnosis apparatus 1 monitors the current value of the electric motor 120, The first time T1 until the loading of the hydraulic system 100 is obtained and the second time T2 until the present time of loading the hydraulic system 100 is obtained and then the flow rate P of the pump 110 is multiplied to obtain the second time T2, 100) is obtained.

The current value of the electric motor 120 is monitored to determine the current value at the time of unloading (always constant). When a larger current flows, the loading time is counted as the loading, Measurement is possible.

Here, it is assumed that the flow rate of the pump 110 and the flow rate of the accumulator 180 (if present) are always constant, and in actual case, the flow rate is constant at a time of failure,

For reference, there is a leak point in the hydraulic system 100, which occurs mainly on the valve side. That is, it is generated in the valve stand 130, the relief valve 140, and the check valve 190 in which various valves are installed, and most of them are caused by wear of the sliding surface or damage to the packing.

Therefore, when a leakage amount due to the internal leakage of the hydraulic system 100 is generated, a problem occurs particularly on the valve side of the hydraulic system 100. Therefore, by using various diagnostic techniques to detect and repair the cause of leakage, It is possible to quickly cope with a failure of the hydraulic system 100 such as a speed reduction.

Hereinafter, the leak diagnosis method (S1) will be described with reference to FIG.

In explaining the leak diagnosis method (S1), description of the same components mentioned in the leak diagnosis apparatus (1) will be omitted.

The leak diagnosis method (S10) according to a preferred embodiment of the present invention includes a step (S10) of measuring a loading time of a hydraulic system in a steady state, a step (S20) of measuring a loading time of the hydraulic system due to a leak, (S30) of calculating a leak amount according to the equation of (S30), and recognizing the leak amount and the leak amount (S40).

(L) = [current loading time (T2) - loading time (T1) in a normal state) * Pump flow rate (P)

In the step S10 of measuring the loading time of the hydraulic system in a steady state, the time taken for loading in the steady-state hydraulic system 100 is measured.

That is, in the case of the normal hydraulic system 100, since the required flow rate is determined in the actuator such as the cylinder, the time taken for loading is always the same. Therefore, when the components of the hydraulic system 100 are determined, the loading time T1 of the hydraulic system 100 will also be set to a predetermined value.

In the step S20 of measuring the loading time of the hydraulic system due to the occurrence of the leak, the loading time of the hydraulic system 100 in which leakage occurs is measured.

 If a leak occurs, a part of the flow rate to the cylinder is lost, so that the pump 110 must be operated more by the lost flow rate, so that the loading time becomes long. In this case, the change of the current value of the electric motor 120 The load time T2 of the hydraulic system 100 according to the leak occurrence is measured.

In the step S30 of calculating the leak amount, the leak amount is calculated through the above-described formula.

In step S40 of recognizing the occurrence of the leak and the amount of the leak, the operator uses the output indicator 250 to recognize the occurrence of the leak and the amount of the leak.

That is, the operator can recognize whether or not the leak has occurred and the leak amount by using the leak diagnosis apparatus 1.

The leak diagnosis apparatus 1 and the leak diagnosis method S1 according to a preferred embodiment of the present invention having the above-described structure can be applied to the hydraulic system 100 without a sensor or an additional device for detecting the internal leakage of the hydraulic system 100, The internal leakage and the leakage amount of the hydraulic system 100 can be detected only by the loading time difference (T2-T1) according to the variation value of the current value of the electric motor 120 installed in the system 100.

As used in this embodiment, the term " portion " refers to a hardware component such as software or an FPGA (field-programmable gate array) or ASIC, and 'part' performs certain roles. However, 'part' is not meant to be limited to software or hardware. &Quot; to " may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, by way of example, 'parts' may refer to components such as software components, object-oriented software components, class components and task components, and processes, functions, , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

1: Liquefaction device 100: Hydraulic system
110: Pump 120: Electric motor
200: diagnosis part 210: signal detector
230: Operator 250: Output indicator
S1: Leak diagnosis method

Claims (6)

A hydraulic system having a pump and a diagnosis unit,
The diagnosis unit may determine leakage occurrence and leak amount by using a loading time of the hydraulic system in a steady state and a loading time of the hydraulic system in response to a leak,
The hydraulic system includes:
Pressure switch;
A solenoid valve opened and closed by the pressure switch;
A relief valve for allowing the hydraulic system to supply a flow rate to the actuator at a predetermined set pressure via the solenoid valve; And
And a non-shock valve disposed between the relief valve and the solenoid valve to reduce a switching shock. The method according to claim 1,
Wherein the hydraulic system is in a loading state below 195 bar by the relief valve and unloaded when it reaches 201 bar. The method according to claim 1,
The hydraulic system further includes an electric motor for driving the pump,
Wherein the diagnosis unit comprises:
A signal detector for detecting a current value of the electric motor;
A calculator for calculating a leak amount by calculating a load time of the hydraulic system based on a current value detected from the signal detector; And
And an output indicator for outputting the leak amount. delete Measuring a loading time of the hydraulic system in a steady state;
Measuring a loading time of the hydraulic system in response to a leak;
Obtaining a leak amount by using a loading time of the hydraulic system in a steady state and a loading time of the hydraulic system in response to a leak; And
And recognizing the leak occurrence and the leakage amount,
The hydraulic system includes:
Pressure switch;
A solenoid valve opened and closed by the pressure switch;
A relief valve for allowing the hydraulic system to supply a flow rate to the actuator at a predetermined set pressure via the solenoid valve; And
And a non-shock valve disposed between the relief valve and the solenoid valve to reduce a switching shock. 6. The method of claim 5,
Wherein the leakage amount is obtained by the following equation.
L = (T2-T1) * P
(L: leak amount, T2: loading time of hydraulic system when leak occurs, T1: loading time of hydraulic system in steady state, P:

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