JP5173688B2 - Industrial vehicle filter fault diagnosis method and apparatus - Google Patents

Description

  The present invention relates to a filter failure diagnosis method and apparatus for industrial vehicles.

  In an industrial vehicle such as a forklift, conventionally, a detection signal of a sensor that detects a filter differential pressure before and after a filter such as an oil filter in the industrial vehicle is monitored in real time, and the value of the detection signal is compared with a threshold value. Thus, whether the filter is normal or abnormal is determined.

Related prior art documents include the following.
JP 2002-92137 A

  In particular, in an industrial vehicle such as a forklift, the driving situation (situation such as driving frequency and driving environment) varies greatly depending on the user's work contents and the like. Therefore, the failure time (life) due to clogging of a filter such as an oil filter in a forklift is also very varied depending on the operation status, so the maintenance time of the filter cannot be set uniformly. For this reason, when the maintenance of the filter is to be performed efficiently, for example, by preparing a replacement filter in advance, it is necessary to estimate the maintenance time of the filter by obtaining the life of the filter according to the operation status There is.

  However, as described above, in the past, only the normal / abnormal judgment is made by monitoring the detection signal of the sensor in real time. Therefore, how much operating time the filter fails (how long is it)? It was not possible to judge, and the maintenance time of the filter could not be estimated.

  Therefore, in view of the above circumstances, an object of the present invention is to provide a filter failure diagnosis method and apparatus for industrial vehicles such as forklifts that can determine the filter life and the filter remaining life according to the driving situation.

A filter failure diagnosis method for an industrial vehicle according to a first invention that solves the above problem is a method for diagnosing a failure due to clogging of a filter in an industrial vehicle,
Detecting the filter differential pressure ΔP before and after the filter at a plurality of times;
Based on the filter differential pressure ΔP before and after the filter detected at the plurality of times, an approximate expression representing the temporal change of the filter differential pressure ΔP is set, and the value of this approximate expression is the filter differential pressure at the life limit. the time to be a [Delta] P _limit, and obtaining a filter life L _H.

を特徴とする。 An industrial vehicle filter failure diagnosis method according to a second aspect of the present invention is the industrial vehicle filter failure diagnosis method according to the first aspect of the present invention,
Based on the filter life L _H and the detected vehicle operating time t _N , the filter remaining life L _R is calculated from the following [Equation 3].

It is characterized by.

The industrial vehicle filter failure diagnosis device according to the third aspect of the present invention is a device for diagnosing a failure due to clogging of a filter in an industrial vehicle,
Filter differential pressure detection means for detecting the filter differential pressure ΔP before and after the filter at a plurality of times;
Based on the filter differential pressure ΔP detected at a plurality of times by the filter differential pressure detecting means, an approximate expression representing the temporal change of the filter differential pressure ΔP is set, and the value of the approximate expression is a filter difference of the life limit. A filter life calculating means for obtaining a time when the pressure ΔP _limit is obtained as a filter life L _H ;
It is provided with.

を備えたことを特徴とする。 An industrial vehicle filter failure diagnosis device according to a fourth aspect of the present invention is the industrial vehicle filter failure diagnosis device according to the third aspect of the invention,
Vehicle operating time detecting means for detecting the operating time t _N of the industrial vehicle;
Based on the filter life L _H calculated by the filter life calculation means and the vehicle operation time t _N detected by the vehicle operation time detection means, the filter remaining life L _R is calculated from the following [Equation 4]. Filter remaining life calculation means,

It is provided with.

According to the filter failure diagnosis method for an industrial vehicle of the first aspect of the present invention, there is provided a method for diagnosing a failure due to filter clogging in an industrial vehicle, wherein the filter differential pressure ΔP before and after the filter is detected at a plurality of times. Based on the filter differential pressure ΔP before and after the filter detected at a plurality of times, an approximate expression representing a temporal change of the filter differential pressure ΔP is set, and the value of this approximate expression is the filter differential pressure ΔP at the life limit. the _limit and becomes time, because it and obtaining a filter life L _H, can be obtained filter life L _H in accordance with the operating conditions of the industrial vehicle.

According to the filter failure diagnosis method for industrial vehicles of the second invention, in the filter failure diagnosis method for industrial vehicles of the first invention, based on the filter life L _H and the detected vehicle operating time t _N , from] expression, because it is characterized in that to calculate the filter remaining lifetime L _R, it is possible to obtain a filter remaining lifetime L _R according to the operating conditions of the industrial vehicle. Therefore, based on this filter remaining lifetime L _R, it is possible to estimate the maintenance timing of the filter in accordance with the operating conditions of the industrial vehicle.

According to the filter failure diagnosis apparatus for industrial vehicles of the third aspect of the present invention, it is an apparatus for diagnosing a failure due to filter clogging in an industrial vehicle, wherein the filter difference detecting the filter differential pressure ΔP before and after the filter at a plurality of times. Based on the pressure detection means and the filter differential pressure ΔP detected at a plurality of times by the filter differential pressure detection means, an approximate expression representing the temporal change of the filter differential pressure ΔP is set, and the value of this approximate expression is filter the time the filter differential pressure [Delta] P _limit the life limit, since the characterized in that a filter life calculation means for calculating a filter life L _H, according to the operating condition of the first invention and the same industrial vehicle Life L _H can be obtained.

According to the filter failure diagnosis apparatus for an industrial vehicle of the fourth invention, in the filter failure diagnosis apparatus for an industrial vehicle of the third invention, the vehicle operation time detection means for detecting the operation time t _N of the industrial vehicle, and the filter life calculation means The filter remaining life calculating means for calculating the filter remaining life L _R from the equation (4) based on the filter life L _H calculated in step S4 and the vehicle operating time t _N detected by the vehicle operating time detecting means. due to the characterized, as in the second invention, it is possible to determine the filter remaining lifetime L _R according to the operating conditions of the industrial vehicle. Therefore, based on this filter remaining lifetime L _R, it is possible to estimate the maintenance timing of the filter in accordance with the operating conditions of the industrial vehicle.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic diagram of a forklift filter failure diagnosis apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram for explaining functions of the filter failure diagnosis apparatus.

  As shown in FIG. 1, the forklift is equipped with a filter 1 such as an oil filter for filtering oil supplied to a clutch of a power transmission system and an air filter for filtering air supplied to an engine or the like. Yes.

  The filter 1 is clogged each time a forklift is operated and a fluid such as oil is filtered, and eventually the fluid filtering function is not performed (the fluid becomes very difficult to flow). For this reason, the filter needs to be appropriately maintained. However, how long the filter will fail, that is, how long the filter clogging will reach its limit (how much filter life has) depends on the operating conditions of the forklift. There are various.

Therefore, in the present embodiment, the filter failure diagnosis device 11 provided in the forklift determines the filter life L _H and the filter remaining life L _R according to the operation status of the forklift.

  Based on FIG. 1 and FIG. 2, each means of this filter failure diagnosis apparatus 11 will be described in detail. Note that the filter failure diagnosis apparatus 11 includes a microcomputer, and calculation processing of each means is performed by software.

  As shown in FIG. 2, in the filter failure diagnostic apparatus 11, first, the filter differential pressure detection means 21 detects the filter differential pressure ΔP before and after the filter 1.

  As the filter differential pressure detection means 21, for example, a first pressure sensor 21A provided on the front side (upstream side in the flow direction of fluid such as oil) of the filter 1 as shown in FIG. The second pressure sensor 21B provided on the downstream side of the flow direction, the pressure detection value of the first pressure sensor 21A (the pressure P1 of the fluid), and the pressure detection value of the second pressure sensor 21B (the above-mentioned And means for calculating a difference (P1−P2) from the fluid pressure P2).

Subsequently, in the filter life calculation means 22, the filter differential pressure ΔP is obtained by an approximation means such as linear approximation or least square method based on the filter differential pressure ΔP before and after the filter 1 detected by the filter differential pressure detection means 21. Set an approximate expression that represents the temporal change in. For example, based on the values of a plurality of filter differential pressures ΔP such as ΔP ₁ , ΔP ₂ , ΔP ₃ detected at each time t ₁ , t ₂ , t ₃ , the time difference of the filter differential pressure ΔP as in the illustrated example is shown. Set an approximate expression that represents the change.

Then, the filter life calculation means 22 calculates the filter life L _H based on the set approximate expression and the life limit filter differential pressure ΔP _limit . That is, the time when the value of the approximate expression becomes the filter differential pressure ΔP _{limit of the} life limit can be obtained as the filter life L _H. For example, when the approximate expression is set by linear approximation of the detected filter differential pressure ΔP, the filter life L _H can be calculated by the following [Equation 5].

The life limit filter differential pressure ΔP _limit is stored in advance in storage means (not shown) such as an IC memory provided in the filter failure diagnosis device 11. The life limit filter differential pressure ΔP _limit is a value at which the filter differential pressure ΔP that increases in response to clogging becomes a limit, that is, the limit filter difference at which the filter 1 becomes too clogged to function as the filter 1. Pressure, which can be determined by experimentation or desktop calculation.

The vehicle operating time detecting means 23 detects a vehicle operating time t _N that is an integrated value of the time for which the forklift is operated. As the vehicle operating time detection means 26, for example, an hour meter 23A as shown in FIG. 1 can be used. The hour meter 23A is provided in the console box of the forklift, and integrates the time from when the starter switch of the engine is turned on to when it is turned off.

Then, the filter remaining life calculation means 24 calculates the following [Equation 6] based on the filter life L _H calculated by the filter life calculation means 22 and the vehicle operation time t _N detected by the vehicle operation time detection means 23. From this, the remaining filter life _LR is calculated.

Thus, the filter failure diagnosis device 11 performs failure diagnosis of the filter 1 such as an oil filter, that is, diagnosis (estimation) of the filter life L _H and diagnosis (estimation) of the filter remaining life L _R according to the operating condition of the forklift. Is called.

As shown in FIG. 1, an alarm device 12 such as a lamp or a buzzer and a display device 13 such as a liquid crystal display are connected to the filter failure diagnosis device 11. As shown in FIG. 2, the alarm device 12 issues an alarm when the filter remaining life L _H is within a predetermined time, and the display device 13 displays the filter remaining life L _H time.

As described above, the forklift filter failure diagnosis device 11 according to the present embodiment is a device for diagnosing a filter failure in a forklift, and detects a filter differential pressure ΔP before and after the filter 1. Based on the pressure detection means 21 and the filter differential pressure ΔP detected by the filter differential pressure detection means 21, an approximate expression representing a temporal change of the filter differential pressure ΔP is set, and the approximate expression and the life limit filter are set. Since the filter life calculation means 22 for calculating the filter life L _H based on the differential pressure ΔP _limit is provided, the filter life L _H corresponding to the operating condition of the forklift can be obtained.

Furthermore, according to the forklift filter failure diagnosis device 11 of the present embodiment, the vehicle operating time detecting means 23 for detecting the operating time t _{N of the} forklift, the filter life L _H calculated by the filter life calculating means 22 and the vehicle The filter remaining life calculating means 24 for calculating the filter remaining life _LR from the equation [6] based on the vehicle operating time t _N detected by the operating time detecting means 23 is provided. it can be obtained filter remaining lifetime L _R according to the operating conditions. Therefore, based on this filter remaining lifetime L _R, maintenance time of the filter in accordance with the operating condition of the forklift (replacement timing) can be estimated.

  In addition, although the case where this invention was applied to a forklift was demonstrated above, it is not limited to this, This invention is applicable also to industrial vehicles other than a forklift.

  The present invention relates to a filter failure diagnosis method and apparatus for industrial vehicles, and is useful when applied to filter failure diagnosis (estimation of filter life and filter remaining life) in industrial vehicles such as forklifts.

1 is a schematic diagram of a forklift filter failure diagnosis apparatus according to an embodiment of the present invention. It is a block diagram explaining the function of the said filter failure diagnostic apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filter 11 Filter failure diagnosis apparatus 12 Alarm apparatus 13 Display apparatus 21 Filter differential pressure detection means 21A 1st pressure sensor 21B 2nd pressure sensor 22 Filter life calculation means 23 Vehicle operating time detection means 23A Hour meter 24 Filter remaining life calculation means

Claims (4)

A method for diagnosing a failure caused by clogging of a filter in an industrial vehicle,
Detecting the filter differential pressure ΔP before and after the filter at a plurality of times;
Based on the filter differential pressure ΔP before and after the filter detected at the plurality of times, an approximate expression representing the temporal change of the filter differential pressure ΔP is set, and the value of this approximate expression is the filter differential pressure at the life limit. the time to be a [Delta] P _limit, filter failure diagnosis method for an industrial vehicle and obtaining a filter life L _H. In the industrial vehicle filter failure diagnosis method according to claim 1,
Based on the filter life L _H and the detected vehicle operating time t _N , the filter remaining life L _R is calculated from the following [Equation 1]:

A filter failure diagnosis method for industrial vehicles. An apparatus for diagnosing a failure due to clogging of a filter in an industrial vehicle,
Filter differential pressure detection means for detecting the filter differential pressure ΔP before and after the filter at a plurality of times;
Based on the filter differential pressure ΔP detected at a plurality of times by the filter differential pressure detecting means, an approximate expression representing the temporal change of the filter differential pressure ΔP is set, and the value of the approximate expression is a filter difference of the life limit. A filter life calculating means for obtaining a time when the pressure ΔP _limit is obtained as a filter life L _H ;
An industrial vehicle filter failure diagnosis apparatus comprising: In the industrial vehicle filter failure diagnosis apparatus according to claim 3,
Vehicle operating time detecting means for detecting the operating time t _N of the industrial vehicle;
Based on the filter life L _H calculated by the filter life calculation means and the vehicle operation time t _N detected by the vehicle operation time detection means, the filter remaining life L _R is calculated from the following [Equation 2]. Filter remaining life calculation means,

An industrial vehicle filter failure diagnosis apparatus comprising:

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