JPS5983811A - Fault diagnostic device of hydraulic apparatus - Google Patents

Abstract

PURPOSE:To conduct a fault diagnosis while a hydaulic apparatus is operated by detecting a flow rate flowing a drain circuit to be compared with a preset flow rate and operating a display device when a detection value is more than a set value. CONSTITUTION:A drain circuit 4 of a hydraulic pump 1 and a drain circuit 5 of a hydraulic motor 2 are provided with flow detectors 6, 7 and the detection values EP1, EM1 are sent to a control portion 8 to be compared with respective preset values corresponding to flow rate flowing in the respective drain circuits when any abnormality is caused in the hydraulic pump and the hydraulic motor. When an abnormality abrasion or breakage of sliding portions is caused in the hydraulic pump or the hydraulic motor, the quantity of oil flowing from the sliding portion increases to increase flow rate flowing in the drain circuit. If the flow rate is more than a preset value, signals EP2, EM2 are output from the control portion to operate fault indication lamps 9P, 9M for the hydraulic pump and the hydraulic motor in a display device 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is intended to prevent failures in hydraulic equipment equipped with a drain circuit, such as hydraulic pumps, hydraulic motors, and hydraulic control valves, among hydraulic equipment used in hydraulic equipment such as machine tools and working machines. Related to diagnostic equipment.

BACKGROUND OF THE INVENTION Normally, in hydraulic equipment for machine tools, working machines, etc., failure diagnosis is performed on the hydraulic equipment used in the equipment in order to operate the equipment smoothly and prevent accidents. Traditionally, failure diagnosis for hydraulic equipment involves stopping the operation of the hydraulic equipment, and
This was done by disassembling the hydraulic equipment and inspecting each part. For this reason, there has been a drawback that it poses a problem in carrying out work using the hydraulic system and requires a lot of effort and time for fault diagnosis.

An object of the present invention is to provide a failure diagnosis device for hydraulic equipment, which eliminates the above-mentioned conventional drawbacks and is capable of diagnosing a failure in a hydraulic equipment equipped with a drain circuit while the hydraulic equipment and the hydraulic equipment are kept in operation. It is in.

In order to achieve this object, the present invention, in a hydraulic device equipped with a drain circuit, stores in advance a flow rate flowing into the drain circuit as a set value when an abnormality occurs in the hydraulic device; A flow rate detection device is interposed in the flow rate detection device, the flow rate detected by the flow rate is compared with the set value, and a display device is activated when the detected flow rate exceeds the set value. .

The present invention will be explained below based on the embodiment shown in FIG.

In the figure, 1 is a hydraulic pump, 2 is a hydraulic motor driven by the hydraulic pump 1, and 3 is a tank for storing hydraulic oil. A hydraulic pump 1, a hydraulic motor 2, and a tank 3 constitute one hydraulic system. 4 is a drain circuit provided between the hydraulic pump 1 and the tank 3; 5 is the hydraulic motor 2 and the tank 3;
This is a drain circuit provided between the As is well known, the hydraulic pump 1 and the hydraulic motor 2 have sliding parts that slide when they are driven, and a small amount of oil flows out from these sliding parts when they are driven. Smooth sliding of parts is maintained. This spilled oil is usually 1
Whenever the pressure of the collected oil is higher than the pressure of the pneumatically pressurized hydraulic oil stored in the tank 3, it is discharged into the tank 3. The drain circuit 4.5 is a conduit provided for this purpose. 6 is a flow rate detector that detects the flow rate of the drain circuit 4, and 7 is a flow rate detector that detects the flow rate of the drain circuit 5, both of which output electrical signals according to the detected flow rate. A control section 8 inputs signals from the flow rate detectors 6 and 7 and performs necessary processing based on the signals, and is composed of an && Qi circuit, a microcomputer, and the like. Details of the control unit 8 will be described later. Reference numeral 9 denotes a display section that is activated by an output signal from the control section 8, and is composed of an indicator lamp 9P that indicates a failure of the hydraulic pump 1 and an indicator lamp 9M that indicates a failure of the hydraulic motor 2.

By the way, if an abnormality occurs in the hydraulic pump 1 or the hydraulic motor 2 (1), for example, if an abnormality occurs in the sliding parts, such as wear or damage,
The amount of oil flowing out from this sliding part increases suddenly, the pressure of the collected oil also increases, and eventually the flow rate of oil flowing through the drain circuit also increases. In this embodiment, this phenomenon is captured to determine the presence or absence of a failure. For this purpose, a flow rate detector 6.7 is provided in the drain circuit 4.5, and the detected flow rate indicates a failure. The controller 8 is configured to make a determination as to whether or not this is the case.

Here, the operation of this embodiment will be explained with reference to the flowchart of the operation of the control section shown in FIG.

As described above, oil flowing out from the hydraulic pump 1 and the hydraulic motor 2 flows into the drain circuits 4 and 5, and the flow rate of this oil is detected by the flow rate detectors 6 and 7.

The flow rate signal of the drain circuit 4 detected by the flow rate detector 6 is expressed as E, 1. Drain circuit 5 detected by flow rate detector 7
If the flow rate signal of is EMI, these signals E□, 9,
is input to the control section 8. In the control section 8, first, the signal "
Input the PI.From the first step S1, each step S3, S, . . . is indicated by a parable. ), then this signal EP,
is compared with the set value EP0 (S,). Setting value E. teeth,
When there is an abnormality in the hydraulic pump 1, that is, when a failure occurs or there are signs of failure, for example, when the sliding parts have progressed to a considerable degree of wear, the value corresponding to the flow rate flowing into the drain circuit. It is said that This setting value E. can be set to various values empirically or experimentally for each hydraulic pump. In the second step St, the signal By
+ is the setting value E. If it is determined that the above is the case, the control unit 8
From the indicator lamp 9PI/r of the display unit 9, the signal E
, t is output (S,), and the display lamp 9P is turned on or flashed to indicate an abnormality in the hydraulic pump l. Second step S! When it is determined that the signal E, 1 is smaller than the set value E'po, and after outputting the signal Pot, the signal EM'l is input this time (S4), and this signal EMI and the set value E
,. Compare with (S,). The set value EMO is also a set value determined for the hydraulic motor 2 in the same manner as for the hydraulic pump 1. Signal EM 1 is set value E,. If it is determined that the above is the case, the control unit 8 outputs a signal EM2 to the indicator lamp 9M of the display unit 9 (S6), and the indicator lamp 9M is turned on or blinks to indicate the abnormality of the hydraulic motor 1. In the fifth step S, the signal EMI changes to the set value EMO.
When it is determined that it is smaller, and after outputting the signal EM2, the operation returns to the first step S, and this is repeated thereafter.

In this way, in this embodiment, the flow rate of oil flowing into the drain circuit of the hydraulic pump and hydraulic motor is detected, this is compared with a predetermined set value, and when the detected flow rate is greater than the set value, the indicator lamp is turned on. Since the hydraulic pump and the hydraulic motor are operated, a failure diagnosis can be performed while the hydraulic pump and hydraulic motor are in an operating state. Furthermore, it is possible to clearly distinguish whether an abnormality has occurred in the hydraulic pump or the hydraulic motor.

In addition, in the above embodiment, an indicator lamp is shown to notify an abnormality, but other indicators or alarms can also be used. In addition, although one hydraulic pump and one hydraulic motor were shown in the above embodiment, it is of course applicable to any hydraulic equipment having a drain circuit, without being limited to a hydraulic pump or a hydraulic motor. Moreover, there is no limit to the number of hydraulic devices. Furthermore, instead of the flow rate detector in the above embodiment, a type of detector that detects a differential pressure that varies depending on the flow rate may be used. Furthermore, it is also possible to use a flow rate switch that operates when the flow rate exceeds a predetermined value. In this case, by connecting this flow rate switch to a display device, the flow rate detector and control unit can be integrated into one. can.

As described above, in the present invention, the flow rate of oil flowing into the drain circuit of hydraulic equipment is detected, this is compared with a predetermined set value, and when the detected flow rate is equal to or higher than the set value, the display device is activated. This makes it possible to diagnose failures while the hydraulic equipment is in operation. Furthermore, in a hydraulic system in which a large number of hydraulic devices are used, it is possible to clearly distinguish which hydraulic device is experiencing an abnormality.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a hydraulic circuit and an electric circuit of a failure diagnosis apparatus for hydraulic equipment according to an embodiment of the present invention, and FIG. 2 is a flowchart of the operation of the control section shown in FIG. 1. 1... Hydraulic pump, 2... Hydraulic motor, 4, 5... Drain circuit, 6, 7...
Flow rate detector, 8...Control unit, 9...Display unit, 9P, 9M...Display lamp. 1st diagram 2nd diagram

Claims (1)

[Claims] In a hydraulic device equipped with a drain circuit, there is provided a flow rate detection device that detects the flow rate of the drain circuit, a detection value detected by the flow detection device, and a predetermined drain circuit flow rate setting value at the time of an abnormality of the hydraulic device. A failure diagnosis device for hydraulic equipment, comprising means for comparing the flow rate and a display device that is activated when the detected value exceeds the flow rate setting value.