JP7001538B2 - Fluid leak detection system - Google Patents

Description

The present invention relates to a fluid leak detection system.

Patent Document 1 discloses a pressure detector that detects the pressure of a working fluid as a fluid detector that detects the state of the working fluid supplied to the fluid pressure device. Such a pressure detector has a detection unit that comes into contact with the working fluid and an output unit that outputs the value detected by the detection unit to the outside.

Japanese Unexamined Patent Publication No. 2006-288444

In a fluid pressure cylinder, in order to detect a fluid leak through a sealing member on the outer periphery of a piston rod, it is conceivable to detect the leaked fluid by using a fluid detector as disclosed in Patent Document 1. In this case, for example, the shorter the detection interval by the detector, the faster and more reliable the detection of fluid leakage. On the other hand, if the detection interval is short, unnecessary data such as data in a state where the fluid pressure cylinder is not operating may be collected.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fluid leakage detection system capable of efficiently detecting a fluid leakage in a fluid pressure cylinder.

The present invention is a fluid leakage detection system for detecting leakage of working fluid in a fluid pressure cylinder, and the state amount of working fluid leaking through a gap between a piston rod and a cylinder head provided in a fluid pressure cylinder is determined. A measuring unit for measuring and a controller for acquiring the measurement result of the measuring unit are provided, and the measuring unit has a measuring unit for measuring and outputting the state amount of the working fluid in the detection space under predetermined operating conditions. The unit is configured to be able to measure at least one of the pressure and temperature in the detection space, and the controller determines the leak determination unit that determines the leakage of the working fluid and the operating conditions of the measurement unit based on the state quantity measured by the measurement unit. It has a condition setting unit for setting and a determination unit for determining whether to change the operating condition according to at least one of the pressure and temperature measured by the measuring unit, so that the measuring unit can measure the pressure. The determination unit is configured, and is characterized in that the pressure data before and after the time series obtained from the measurement result of the measurement unit is compared to determine the change of the operating condition .

In the present invention, the operating conditions of the measuring unit are changed according to at least one of the pressure and the temperature measured by the measuring unit of the measuring unit. As a result, for example, the operating conditions are set so that the operating frequency is relatively low in normal times, and when a sign of fluid leakage is detected from the measurement results, the operating conditions are changed so as to increase the operating frequency, and the fluid leakage occurs. The detection accuracy of can be improved. As described above, in the present invention, the measurement unit can be operated under the optimum operating conditions depending on whether high detection accuracy is required or not.

In the present invention, the measuring unit measures the pressure in each measurement cycle having a predetermined time length and repeated at a predetermined time interval, and the judgment unit measures the pressure data before and after in time series within the same measurement cycle. It is characterized in that the change of the operating condition is judged by comparing.

In the present invention, the measuring unit measures the pressure in each measurement cycle having a predetermined time length and repeated at a predetermined time interval, and the judgment unit uses the pressure data in the current measurement cycle input to the controller and the pressure data in the current measurement cycle. It is characterized by comparing with the pressure data in the measurement cycle before the previous time to judge the change of the operating condition.

The present invention is characterized in that the determination unit determines that the operating condition is changed if the difference between the pressure data before and after the time series is equal to or more than a predetermined difference threshold value.

In these inventions, the sign of the occurrence of an oil leak can be detected by comparing the pressure data before and after in time series.

The present invention includes, as a measurement unit, a first measurement unit and a second measurement unit provided in a pair of fluid pressure cylinders that drive the same drive target, respectively, and the determination unit includes the measurement results of the first measurement unit and the measurement results of the first measurement unit. It is characterized by comparing with the measurement result of the second measurement unit.

In the present invention, by comparing the pressure data of a pair of fluid pressure cylinders driving the same drive target, it is possible to detect a sign of accidental oil leakage occurring in one of the fluid pressure cylinders. can.

The present invention is characterized in that, when it is determined by the determination unit that the operating conditions are changed, the operating conditions of the measuring units in each of the first measuring unit and the second measuring unit are changed to the same conditions.

In the present invention, the operating conditions of the measuring units in each of the first measuring unit and the second measuring unit are changed under the same conditions, so that even after the operating conditions are changed, the fluid pressure cylinder remains in the same operating state. The measurement results of each other can be compared. This facilitates comparison of the measurement results of the first measurement unit and the second measurement unit.

The present invention is characterized in that the determination unit calculates the operating time of the fluid pressure cylinder and determines the change of the operating condition based on the operating time.

The present invention is characterized in that the measuring unit is configured to be able to measure the temperature, and the determining unit calculates the operating time based on the measurement time when the measuring unit detects a temperature equal to or higher than a predetermined temperature threshold.

In these inventions, signs of oil leakage based on the life of the rod seal can be detected.

In the present invention, the controller has an information acquisition unit that acquires operation information of the fluid pressure cylinder or the fluid pressure drive machine including the fluid pressure cylinder, and the determination unit operates based on the operation information acquired by the information acquisition unit. It is characterized by calculating the time.

In the present invention, the hydraulic pressure drive machine is a construction machine, the judgment unit acquires the on-off signal of the ignition switch for starting the construction machine as operation information, and the cumulative time during which the ignition switch is turned on. It is characterized in that the operating time is calculated based on the above.

In these inventions, in addition to the measurement result of the measuring unit, the sign of oil leakage based on the life of the rod seal can be detected based on the operation information of the fluid pressure cylinder or the fluid pressure drive machine.

In the present invention, the measuring unit measures at least one of pressure and temperature by a predetermined sampling cycle for each measurement cycle having a predetermined time length and repeated at a predetermined time interval, and as a predetermined data capacity. When at least one of the pressure and the temperature is measured by the transmission capacity of, the measurement result is output to the controller, and the condition setting unit sets the operating conditions such as the length of the measurement cycle, the time interval in which the measurement cycle is repeated, the sampling cycle, and the measurement cycle. It is characterized by changing at least one of the transmission capacities.

In the present invention, the measuring unit has a battery as a power source, and the condition setting unit determines an aspect of changing the operating conditions based on the remaining battery level of the battery.

In the present invention, it is possible to improve the accuracy of detecting fluid leakage and suppress the decrease in battery life at the same time.

According to the present invention, the detection of fluid leakage by the fluid leakage detection system is made efficient.

It is a schematic diagram which shows the structure of the fluid leakage detection system which concerns on embodiment of this invention. It is a partial sectional view of the hydraulic cylinder which concerns on embodiment of this invention. It is an enlarged sectional view of the hydraulic cylinder which concerns on embodiment of this invention. It is a block diagram which shows the measurement unit of the fluid leakage detection system which concerns on embodiment of this invention. It is a block diagram which shows the control unit of the fluid leakage detection system which concerns on embodiment of this invention. It is a schematic graph for explaining the operation of the fluid leakage detection system which concerns on embodiment of this invention, the vertical axis shows the data capacity stored in the data storage part, and the horizontal axis shows time. It is a block diagram which shows the modification of the control unit of the fluid leakage detection system which concerns on embodiment of this invention.

Hereinafter, the fluid leakage detection system 100 according to the embodiment of the present invention will be described with reference to the drawings.

First, with reference to FIG. 1, the overall configuration of the fluid pressure system 101 including the fluid leakage detection system 100 will be described.

The fluid pressure system 101 is used for construction machinery as a fluid pressure drive machine, particularly a hydraulic excavator. The fluid pressure system 101 controls the flow of working fluid supplied to and discharged from the plurality of fluid pressure cylinders to drive the fluid pressure cylinders.

As shown in FIG. 1, the fluid pressure system 101 includes a hydraulic cylinder 1 as a fluid pressure cylinder for driving a drive target (not shown) such as a boom, an arm, and a bucket, and hydraulic oil supplied to and discharged from the hydraulic cylinder 1 (not shown). Fluid leak detection that detects oil leakage through the fluid pressure control device 102 that controls the operation of the hydraulic cylinder 1 by controlling the working fluid) and the rod seal 11 (see FIG. 3) as a sealing member provided in the hydraulic cylinder 1. The system 100 is provided.

In this embodiment, the fluid pressure system 101 includes a pair of hydraulic cylinders 1 that drive the same drive object. In the fluid pressure system 101, one drive target is driven by the pair of hydraulic cylinders 1 operating in synchronization with each other. Hereinafter, each of the pair of hydraulic cylinders 1 is also referred to as a “hydraulic cylinder 1a” and a “hydraulic cylinder 1b”.

As shown in FIG. 2, the hydraulic cylinder 1 includes a cylindrical cylinder tube 2, a piston rod 3 inserted into the cylinder tube 2, and a piston 4 provided at the base end of the piston rod 3. The piston 4 is slidably provided along the inner peripheral surface of the cylinder tube 2. The inside of the cylinder tube 2 is divided into a rod side chamber (fluid pressure chamber) 2a and an anti-rod side chamber 2b by a piston 4.

The tip of the piston rod 3 extends from the open end of the cylinder tube 2. When hydraulic oil is selectively guided from a hydraulic source (not shown) to the rod side chamber 2a or the anti-rod side chamber 2b, the piston rod 3 moves with respect to the cylinder tube 2. As a result, the hydraulic cylinder 1 expands and contracts.

A cylinder head 5 through which the piston rod 3 is inserted is provided at the open end of the cylinder tube 2. The cylinder head 5 is fastened to the open end of the cylinder tube 2 using a plurality of bolts 6.

Since the fluid pressure control device 102 can adopt a known configuration, detailed illustration and description thereof will be omitted. The fluid pressure control device 102 controls the flow of hydraulic oil guided from the hydraulic pump (hydraulic source) to each hydraulic cylinder 1 to operate each hydraulic cylinder 1.

Next, the fluid leakage detection system 100 will be specifically described.

In the fluid leak detection system 100, hydraulic oil leaks from the rod side chamber 2a between the outer peripheral surface of the piston rod 3 and the inner peripheral surface of the cylinder head 5 in each of the pair of hydraulic cylinders 1 that drive the same drive target. Detects the occurrence of oil leaks (fluid leaks).

As shown in FIGS. 1 and 3, the fluid leak detection system 100 is provided in the hydraulic cylinder 1 and has an annular gap between the outer peripheral surface of the piston rod 3 and the inner peripheral surface of the cylinder head 5 (hereinafter, “annular gap 8”. A measurement unit 10 for measuring the state amount of the hydraulic oil leaking from the measurement unit 10 and a control unit 70 for determining the occurrence of an oil leak in the hydraulic cylinder 1 based on the measurement result of the measurement unit 10.

As shown in FIG. 1, the measuring unit 10 is provided in each of the pair of hydraulic cylinders 1. Hereinafter, the measuring unit 10 provided in one hydraulic cylinder 1a is also referred to as a “first measuring unit 10a”, and the measuring unit 10 provided in the other hydraulic cylinder 1b is also referred to as a “second measuring unit 10b”, if necessary.

As shown in FIG. 3, the measuring unit 10 includes a rod seal 11 provided on the cylinder head 5 and a rod seal 11 for sealing an annular gap 8 between the outer peripheral surface of the piston rod 3 and the inner peripheral surface of the cylinder head 5, and a rod side chamber. A detection space 20 in which hydraulic oil leaking from 2a beyond the rod seal 11 is guided, a detection seal 12 provided in the cylinder head 5 to seal the annular gap 8 and partitioning the detection space 20 together with the rod seal 11, and detection. The communication passage 21 communicating with the space 20, the relief valve 30 that opens when the pressure of the communication passage 21 reaches the relief pressure to release the pressure of the communication passage 21, and the relief valve 30 that exceeds the rod seal 11 and leaks into the detection space 20. It includes a measuring unit 50 for measuring the state amount of the hydraulic oil, and a housing 40 for accommodating the relief valve 30 and the measuring unit 50.

A rod seal 11, a bush 13, a detection seal 12, and a dust seal 14 are interposed on the inner circumference of the cylinder head 5 in this order from the base end side (right side in FIG. 3) to the tip side (left side in FIG. 3). Will be done. The rod seal 11, the bush 13, the detection seal 12, and the dust seal 14 are housed in the annular grooves 5a, 5b, 5c, and 5d formed on the inner circumference of the cylinder head 5, respectively.

When the bush 13 is in sliding contact with the outer peripheral surface of the piston rod 3, the piston rod 3 is supported so as to move in the axial direction of the cylinder tube 2.

The rod seal 11 is compressed between the outer periphery of the piston rod 3 and the annular groove 5a on the inner circumference of the cylinder head 5, thereby sealing the annular gap 8. The rod seal 11 faces the rod side chamber 2a (see FIG. 2), and the rod seal 11 prevents the hydraulic oil in the rod side chamber 2a from leaking to the outside. The rod seal 11 is a so-called U packing.

The dust seal 14 is provided on the cylinder head 5 so as to face the outside of the cylinder tube 2 and seals the annular gap 8. The dust seal 14 scoops out dust adhering to the outer peripheral surface of the piston rod 3 to prevent dust from entering the cylinder tube 2 from the outside.

Like the rod seal 11, the detection seal 12 is compressed between the outer periphery of the piston rod 3 and the annular groove 5c on the inner circumference of the cylinder head 5, thereby sealing the annular gap 8. The detection seal 12 is provided between the rod seal 11 and the dust seal 14, and together with the rod seal 11, partitions the detection space 20. That is, the detection space 20 is a space partitioned by the piston rod 3, the cylinder head 5, the rod seal 11, and the detection seal 12 (in this embodiment, the bush 13 in addition to the piston rod 3). The detection seal 12 is a U packing like the rod seal 11.

The communication passage 21 is formed over the cylinder head 5 and the housing 40 so as to communicate with the detection space 20. The communication passage 21 has a first communication passage 22 formed in the cylinder head 5 and opening to the detection space 20, and a second communication passage 23 formed in the housing 40 and communicating with the first communication passage 22. The hydraulic oil of the rod side chamber 2a leaking from the rod seal 11 is guided to the communication passage 21 through the annular gap 8 and the detection space 20.

The relief valve 30 opens when the pressure of the hydraulic oil in the second connecting passage 23 reaches a predetermined pressure (relief pressure), and discharges the hydraulic oil in the detection space 20 to the outside through the second connecting passage 23. As a result, the pressure in the detection space 20 is limited to the relief pressure by the relief valve 30. Since a known structure can be adopted for the structure of the relief valve 30, detailed illustration and description thereof will be omitted.

The housing 40 is fixed to the end of the cylinder head 5 by press fitting. The housing 40 is further formed with a sensor accommodating hole 41 accommodating the measuring unit 50 and a valve accommodating hole 42 accommodating the relief valve 30. The sensor accommodating hole 41 and the valve accommodating hole 42 communicate with the second communication passage 23, respectively, and the valve accommodating hole 42 communicates with the second communication passage 23 on the first communication passage 22 side (upstream side) of the sensor accommodating hole 41. is doing.

The measuring unit 50 executes the measurement of the pressure as the state quantity of the hydraulic oil and the output of the measurement result to the control unit 70 under predetermined operating conditions. In other words, the measuring unit 50 measures the pressure and outputs the measurement result at a predetermined operating frequency based on a predetermined operating condition. The operation frequency includes a measurement frequency in which the measuring unit 50 measures pressure and temperature, and a transmission frequency in which the measurement result is transmitted from the measuring unit 50 to the control unit 70. Further, the measuring unit 50 is configured to be able to measure the temperature in the detection space 20.

As shown in FIG. 4, the measuring unit 50 outputs a command signal to the sensor unit 51, which is a pressure temperature sensor capable of measuring both pressure and temperature, and acquires the measurement result of the sensor unit 51. A sensor controller 60, a first communication unit 52 that transmits and receives signals to and from the control unit 70 by wireless communication, a sensor unit 51, a sensor controller 60, and a battery 54 that is a power source (power source) for the first communication unit 52. Has.

The measuring unit 50 is configured by incorporating the sensor unit 51, the sensor controller 60, and the battery 54 into the same housing, respectively, and as shown in FIG. 3, one in the sensor accommodating hole 41 formed in the housing 40. The part is housed. Further, the measuring unit 50 is fixed to the screw hole 24 communicating with the second communication passage 23 of the housing 40 by screwing.

The sensor unit 51 measures the pressure and temperature in the detection space 20. As a result, the pressure and temperature of the hydraulic oil guided to the detection space 20 through the first passage 22 and the second passage 23 (see FIG. 3) are measured by the sensor unit 51. The operation of the sensor unit 51 will be described in detail later.

The battery 54 is electrically connected to the sensor controller 60, the sensor unit 51, and the first communication unit 52. The sensor controller 60, the sensor unit 51, and the first communication unit 52 operate by supplying power from the battery 54, respectively.

The sensor controller 60 is composed of a microcomputer provided with a CPU (central processing unit), ROM (read-only memory), RAM (random access memory), and an I / O interface (input / output interface). The RAM stores data in the processing of the CPU, the ROM stores the control program of the CPU in advance, and the I / O interface is used for input / output of information with the connected device. The sensor controller 60 may be composed of a plurality of microcomputers. The sensor controller 60 is programmed to be capable of performing at least the processes required for control by the sensor controller 60 described herein. The sensor controller 60 may be configured as one device, or may be divided into a plurality of devices, and each control by the sensor controller 60 may be configured to be distributed and processed by the plurality of devices.

The sensor controller 60 has a command unit 61 that outputs a command signal to the sensor unit 51, and a data storage unit 62 that acquires and stores the measurement result of the sensor unit 51 and the remaining battery level of the battery 54.

Based on the command signal from the command unit 61, the sensor unit 51 operates under predetermined operating conditions to measure the pressure and temperature of the detection space 20. The measurement result of the sensor unit 51 is input to the data storage unit 62.

The data storage unit 62 accumulates the measurement result of the sensor unit 51 and the remaining battery level of the battery 54, and outputs the accumulated data to the control unit 70 under predetermined operating conditions (transmission frequency). The transmission frequency for outputting data from the data storage unit 62 can be changed according to the command signal of the command unit 61.

The first communication unit 52 is electrically connected to the sensor controller 60 and transmits / receives a signal to / from the sensor controller 60. Further, the first communication unit 52 is configured to enable wireless communication with the control unit 70.

The control unit 70 is arranged, for example, in the cab of the construction machine. As shown in FIG. 5, the control unit 70 has a second communication unit 71 that transmits and receives signals by wireless communication with the first communication unit 52 of the measurement unit 50, and the measurement unit 50 of the measurement unit 10 through the second communication unit 71. A controller 80 for transmitting and receiving signals to and from the controller 80 is provided.

The controller 80 is composed of a microcomputer including a CPU (central processing unit), a ROM (read-only memory), a RAM (random access memory), and an I / O interface (input / output interface). The RAM stores data in the processing of the CPU, the ROM stores the control program of the CPU in advance, and the I / O interface is used for input / output of information with the connected device. The controller 80 may be composed of a plurality of microcomputers. The controller 80 is programmed to be capable of performing at least the processing necessary for control by the controller 80 described herein. The controller 80 may be configured as one device, or may be divided into a plurality of devices, and each control in the present embodiment may be configured to be distributed and processed by the plurality of devices.

The controller 80 acquires the measurement result of the measuring unit 50, and determines whether or not an oil leak has occurred in the hydraulic cylinder 1 based on the measurement result of the measuring unit 50. Further, the controller 80 changes the operating conditions of the measuring unit 50 of the measuring unit 10 through the second communication unit 71.

The controller 80 changes the operating conditions of the storage unit 81 that stores the measurement result of the measurement unit 50, the leak determination unit 82 that determines the presence or absence of oil leakage according to the measurement result of the measurement unit 50, and the measurement unit 50. It has a condition setting unit 83, and a determination unit 84 that determines whether or not the operation condition of the measurement unit 50 is changed by the condition setting unit 83 according to the measurement result of the measurement unit 50.

Information transmitted from the sensor controller 60 of the measuring unit 50 (pressure and temperature of the detection space 20 and the remaining battery level of the battery 54) is stored in the storage unit 81 and input to the determination unit 84 and the leakage determination unit 82. To.

The leak determination unit 82 determines whether or not oil leakage has occurred in each of the pair of hydraulic cylinders 1 based on the pressure value as the state quantity measured by the sensor unit 51 of the first measurement unit 10a and the second measurement unit 10b. Is determined. The leak determination unit 82 determines the occurrence of an oil leak each time the measurement results of the first measurement unit 10a and the second measurement unit 10b are input.

The determination unit 84 determines whether there is a sign that oil leakage occurs in the hydraulic cylinder 1 to which the measurement unit 10 is attached, based on the measurement result of the measurement unit 50 of the measurement unit 10. When the determination unit 84 determines that there is a sign of oil leakage, it determines that the operating conditions of the measurement unit 50 are changed. The determination result of the determination unit 84 is input to the condition setting unit 83.

When the judgment result of the judgment unit 84 changes the operating condition, the condition setting unit 83 makes a new change to the command unit 61 of the sensor controller 60 through the first and second communication units 52 and 71. A command signal including various operating conditions is transmitted. Upon receiving the command signal from the condition setting unit 83, the command unit 61 of the sensor controller 60 outputs the command signal to the sensor unit 51 and / or the data storage unit 62 so as to operate under the new operating conditions.

Next, the operation of the fluid leak detection system 100 will be described.

First, the operation of the measuring unit 50 of the measuring unit 10 will be specifically described.

The sensor unit 51 measures the pressure and temperature by a predetermined sampling cycle for each measurement cycle having a predetermined time length and repeated at a predetermined time interval. The data storage unit 62 transmits the accumulated data (measurement result of the sensor unit 51 and the remaining battery level of the battery 54) to the control unit 70 through the first communication unit 52 at a predetermined frequency. In the following, the time length of the measurement cycle (time from the start to the end of the measurement cycle) is referred to as "measurement time Td", and the time interval from the start of one measurement cycle to the start of the next measurement cycle is referred to as "cycle interval CT". .. Further, the sampling cycle of the sensor unit 51 is referred to as “sampling cycle SC”, and the data capacity accumulated until the data storage unit 62 transmits (outputs) the measurement result is referred to as “transmission capacity Dc”. The operating conditions of the measuring unit 50 are the measurement time Td, the sampling cycle SC, the cycle interval CT, which are the conditions under which the sensor unit 51 detects pressure and temperature, and the data storage unit 62 controls the measurement results of the sensor unit 51. The transmission capacity Dc to be transmitted to the controller 80 of the above is included.

FIG. 6 is a schematic graph showing the relationship between the time and the data capacity of the measurement result stored in the data storage unit 62. As shown in FIG. 6, the sensor unit 51 measures the pressure and temperature in the detection space 20 for each sampling cycle SC during the measurement time Td, and when the measurement time Td elapses from the start of the measurement, the pressure and temperature are measured. To finish. After the measurement of pressure and temperature is completed, the sensor unit 51 goes into a standby state (sleep state) in which the pressure and temperature are not measured.

The measurement result of the sensor unit 51 is stored in the data storage unit 62. The data storage unit 62 outputs the accumulated data to the first communication unit 52 every time the measurement result is accumulated for the transmission capacity Dc. In FIG. 6, the data capacity of the measurement results for five times corresponds to the transmission capacity Dc. The first communication unit 52 wirelessly transmits the data output from the data storage unit 62 to the second communication unit 71 of the controller 80. The transmission frequency is determined according to the transmission capacity Dc in which data is transmitted from the data storage unit 62 of the sensor controller 60 in the measurement unit 50 to the controller 80.

As shown in FIG. 6, the data storage unit 62 erases the accumulated data each time the accumulated data is output to the first communication unit 52, but the data storage unit 62 is not limited to this and continues to accumulate the data. But it may be.

In this way, the sensor unit 51 does not constantly (continuously) measure the pressure and temperature in the detection space 20, but intermittently measures them. Further, the measurement result of the sensor unit 51 is not immediately transmitted to the controller 80, but is transmitted to the controller 80 when only the transmission capacity Dc is stored in the data storage unit 62. That is, the measurement result of the sensor unit 51 is intermittently transmitted to the controller 80. Since the measurement by the sensor unit 51 and the transmission of the measurement result from the data storage unit 62 are executed intermittently, the power consumption can be reduced. The sensor unit 51 and the data storage unit 62 can also execute continuous measurement and output (data transmission) of the measurement results, respectively.

Next, the determination of oil leakage by the controller 80 will be described.

As the deterioration of the rod seal 11 of the hydraulic cylinder 1 progresses, the hydraulic pressure of the rod side chamber 2a is guided beyond the rod seal 11 into the detection space 20. Therefore, as the rod seal 11 deteriorates, the pressure and temperature of the detection space 20 increase. In the fluid leak detection system 100, the pressure in the detection space 20 is measured by the measuring unit 50 of the measuring unit 10, and the controller 80 of the control unit 70 determines whether or not an oil leak has occurred based on the measurement result. An oil leak in the cylinder 1 is detected. In the present specification, the "deterioration" of the rod seal 11 includes wear and damage. The wear is caused by a steady load such as the reciprocating movement of the piston rod 3, and refers to deterioration due to the life. Damage refers to deterioration caused by accidental load due to an accident or the like.

To specifically explain the determination of oil leakage, in the present embodiment, the determination of oil leakage is performed based on the pressure in the detection space 20. The leak determination unit 82 of the controller 80 acquires the maximum pressure value as pressure data from the transmitted data group each time the measurement result of the sensor unit 51 is transmitted from the data storage unit 62 of the sensor controller 60. The leak determination unit 82 compares the maximum pressure value with a predetermined determination threshold value, and determines that an oil leak has occurred when the maximum pressure value is equal to or greater than the determination threshold value. When the leak determination unit 82 determines that an oil leak has occurred, the determination result is transmitted to the notification unit (not shown), and the operator is notified of the occurrence of the oil leak. In this way, an oil leak in the hydraulic cylinder 1 is detected. On the other hand, when the maximum pressure value is smaller than the determination threshold value, the leak determination unit 82 determines that no oil leak has occurred.

In addition, "no oil leakage" in the present specification does not mean exactly, but does not mean only that the hydraulic oil does not leak into the detection space 20 beyond the rod seal 11. do not have. For example, even if the hydraulic oil leaks from the rod side chamber 2a into the detection space 20, if the deterioration (wear / damage) of the rod seal 11 is tolerable, the leak determination unit 82 will be set to ". No oil leak has occurred. " That is, "oil leakage has occurred" refers to a state in which deterioration (wear / damage) of the rod seal 11 exceeds an allowable range. Therefore, the determination threshold value is set according to the allowable degree of deterioration (wear / damage) of the rod seal 11.

Further, the pressure data used for determining the oil leak is not limited to the maximum pressure value, and may be other data. For example, the pressure data may be one measured value included in the transmitted data group such as the minimum pressure value or the median value, or may be a value calculated by calculating the measured value such as an average value. May be good. That is, the pressure data includes the measured value of the pressure measured by the sensor unit 51 itself and the value obtained from the measured value.

Next, the change of the operating condition of the measuring unit 50 will be described.

The shorter the sampling cycle SC and the cycle interval CT of the sensor unit 51 and the longer the measurement time Td, the higher the measurement frequency of the sensor unit 51. As a result, the pressure and temperature are measured more, the data capacity acquired by the sensor unit 51 becomes large, and the accuracy of detecting oil leakage is improved. For example, when the sensor unit 51 constantly measures the pressure and temperature in the detection space 20 without entering the standby state (in other words, when the measurement time Td = cycle interval CT), when an oil leak occurs, it is promptly measured. The occurrence of oil leaks can be detected. Further, the smaller the transmission capacity Dc, the higher the transmission frequency. As the transmission frequency increases, the occurrence of oil leaks is frequently determined, so that the accuracy of oil leak detection is improved. As described above, the higher the operation frequency of the measurement unit 50 (measurement frequency of the sensor unit 51 and transmission frequency from the data storage unit 62), the higher the accuracy of oil leak detection by the fluid leak detection system 100.

On the contrary, the longer the sampling cycle SC and the cycle interval CT and the shorter the measurement time Td, the lower the measurement frequency of the sensor unit 51 and the smaller the data capacity of the measured pressure and temperature. Further, the larger the transmission capacity Dc, the lower the transmission frequency. That is, since the number of times the measurement result is output from the sensor controller 60 is small, the number of times the controller 80 determines the occurrence of oil leakage is small. The lower the operating frequency of the measuring unit 50, the lower the accuracy of detecting oil leakage, but the data processing load is reduced, and the power consumption of the battery 54 can be suppressed.

As described above, in order to improve the detection accuracy of oil leakage, it is preferable that the operation frequency of the measuring unit 50 (measurement frequency of the sensor unit 51 and transmission frequency from the data storage unit 62) is high. On the other hand, if the operation frequency of the measuring unit 50 is increased, unnecessary data such as data in a state where the construction machine or the hydraulic cylinder 1 is not operating may be collected. Further, when the measurement frequency and the transmission frequency are high, the power consumption of the battery 54 by the sensor unit 51, the first communication unit 52, and the sensor controller 60 also increases.

Therefore, in the fluid leakage detection system 100 according to the present embodiment, change control for changing the operating conditions of the measuring unit 50 is executed according to the situation.

In the fluid leak detection system 100, when the possibility of oil leakage is small, the measuring unit 50 is operated under the condition that the operation frequency is relatively low to suppress the collection of unnecessary data and the power consumption. .. On the other hand, when a sign of oil leakage appears, the measuring unit 50 is operated under a condition where the operation frequency is relatively high so that the occurrence of oil leakage can be detected early and surely. In this way, by detecting the sign of the oil leak before it occurs and changing the operating conditions of the measuring unit 50, it is possible to improve the efficiency of the oil leak detection.

In change control, as a criterion for determining whether to change the operating conditions, a sign detection process that detects signs of oil leakage and oil with a high operating frequency when signs of oil leakage are detected. Condition change processing, which changes the operating conditions so that the leak detection accuracy is improved, is executed.

[Sign detection processing]
The method for detecting the sign of oil leakage includes pressure sign detection for detecting the sign based on the pressure data of the sensor unit 51 and measurement of the first measuring unit 10a and the second measuring unit 10b provided in the pair of hydraulic cylinders 1. It includes comparative sign detection for comparing the results and time sign detection based on the operating time calculated from the temperature data of the sensor unit 51. In this embodiment, the controller 80 is programmed to enable pressure sign detection, comparative sign detection, and time sign detection, respectively. The controller 80 may execute the pressure sign detection, the comparative sign detection, and the time sign detection independently, or may execute two or more at the same time (in parallel).

Hereinafter, pressure sign detection will be described.

In the pressure sign detection, the signs of oil leakage in the hydraulic cylinder 1 are detected by comparing the pressure data before and after in time series.

As a method of comparing pressure data before and after in time series, there are a comparison of pressure data in the same measurement cycle and a comparison of pressure data in different measurement cycles.

The comparison of the pressure data in the same measurement cycle is, for example, as shown in FIG. 6, in the same measurement cycle as the maximum pressure value included in the current data group G11 transmitted from the measurement unit 50 to the controller 80. The maximum pressure value included in the data group G12 transmitted before the data group G11 is compared with the maximum pressure value. The determination unit 84 acquires the respective maximum pressure values from the data group G11 transmitted this time and the data group G12 transmitted last time. If the difference between the maximum pressure values is equal to or greater than a predetermined difference threshold value, the determination unit 84 determines that the operating conditions are changed because there is a sign that an oil leak has occurred. The data group to be compared is not limited to the previous data group, but may be data before that transmitted within the same measurement cycle (for example, the data group G13 in FIG. 6).

The comparison of the pressure data in different measurement cycles is, for example, comparing the pressure data in the current measurement cycle with the pressure data in the measurement cycle before the previous time. As shown in FIG. 6, assuming that data transmission is performed three times in the measurement cycle, the maximum pressure values of the data groups G11, G12, and G13 transmitted in the current measurement cycle correspond to those in the previous measurement cycle. The maximum pressure values of the data groups G21, G22, and G23 transmitted in order are compared with each other. If the difference between the maximum pressure values of the previous time and the current time is equal to or greater than the difference threshold value, the determination unit 84 determines that the operating conditions are changed because there is a sign of oil leakage. The measurement cycle to be compared is not limited to the previous measurement cycle, and may be a measurement result comparing the measurement results of the previous measurement cycle, for example, the current measurement cycle and the measurement cycle of the previous day detected at substantially the same time.

As described above, by comparing the pressure data before and after in time series, it is possible to detect the pressure increase in the detection space 20 due to the deterioration of the rod seal 11, in other words, the sign of the occurrence of oil leakage.

Next, comparative sign detection will be described.

Normally, the pair of hydraulic cylinders 1a and 1b that drive the same drive target have the same operation history and usage status, so that the pressure and temperature of the detection space 20 in both of them are different regardless of the deterioration of the rod seal 11. , It is hard to make a big difference. However, for example, when an accidental impact acts only on the rod seal 11 of one of the hydraulic cylinders 1a, one of the rod seals 11 may be relatively significantly deteriorated. In such a case, oil leakage occurs from one of the deteriorated rod seals 11, and the pressure and temperature rise only in one of the hydraulic cylinders 1a.

Therefore, in the comparative sign detection, the signs of oil leakage in the pair of hydraulic cylinders 1a and 1b are detected by comparing the measurement results of the first measurement unit 10a and the second measurement unit 10b provided in the pair of hydraulic cylinders 1a and 1b, respectively. To detect.

In the state where no oil leak occurs, the first measurement unit 10a and the second measurement unit 10b operate in synchronization with each other under the same operating conditions. That is, the sensor unit 51 of the first measurement unit 10a and the second measurement unit 10b measures the pressure and temperature at the same timing and in the same measurement cycle. Further, the measurement results of the first measurement unit 10a and the second measurement unit 10b are transmitted from the respective sensor controllers 60 to the controller 80 at the same timing.

The determination unit 84 of the controller 80 acquires pressure data or temperature data from the measurement results of the first measurement unit 10a and the second measurement unit 10b transmitted at the same timing. As with the pressure data, the temperature data is not limited to the measured value of the actually measured temperature, but is the maximum or minimum value of the temperature measured value within a predetermined time range, and further, the temperature measured value such as the average value. It also includes the value obtained by calculating. In the present embodiment, the determination unit 84 acquires the maximum pressure value in each data group transmitted from the first measurement unit 10a and the second measurement unit 10b at the same timing as pressure data, and compares the two. If the difference between the maximum pressure values is equal to or greater than a predetermined comparison threshold value, the determination unit 84 determines that there is a sign of oil leakage and determines that the operating conditions are changed.

By comparing the measurement results of the first measurement unit 10a and the second measurement unit 10b provided in the pair of hydraulic cylinders 1a and 1b in this way, one of the hydraulic cylinders 1 due to accidental deterioration of the rod seal 11 A pressure or temperature rise in the detection space 20, that is, a sign of oil leakage, is detected.

Next, the time sign detection will be described.

Since the rod seal 11 is in sliding contact with the piston rod 3 of the hydraulic cylinder 1, wear (deterioration) occurs as the piston rod 3 slides. Therefore, if the time (period) in which the hydraulic cylinder 1 is used becomes long, oil leakage due to wear of the rod seal 11 is likely to occur.

Therefore, in the time sign detection, the time (operating time) in which the hydraulic cylinder 1 has been used is calculated from the temperature data detected by the sensor unit 51, and the sign of oil leakage is detected.

The determination unit 84 determines the operating time of the hydraulic cylinder 1 as temperature data from the reference time (for example, when the measurement unit 10 is attached) to the time when the data of the measurement unit 50 is transmitted and the determination is made to determine the sign of oil leakage. Calculated from. The determination unit 84 considers that the hydraulic cylinder 1 is operating when the temperature is measured above a predetermined temperature threshold, and measures the temperature above the temperature threshold between the reference time and the determination time (sampling). (Number of times) is accumulated. More specifically, when the data is transmitted from the measurement unit 50, the determination unit 84 measures the temperature equal to or higher than the temperature threshold from the past temperature data stored in the storage unit 81 including the data transmitted this time. The cumulative time (cumulative number of times) is calculated, and the cumulative time (cumulative number of times) is taken as the operating time of the hydraulic cylinder 1. If the operating time exceeds the time threshold value, the determination unit 84 determines that there is a sign of oil leakage, and determines that the operating conditions of the measurement unit 50 are changed.

The temperature threshold value is set to an appropriate value so that the hydraulic cylinder 1 is not determined to be operating due to the influence of changes in the outside air temperature, temperature changes at the time of starting (idling) of the fluid pressure control device 102, and the like.

The time threshold value is appropriately set so that signs of oil leakage can be detected according to the driving target driven by the hydraulic cylinder 1 and the situation in which the hydraulic cylinder 1 is used.

By calculating the operating time of the hydraulic cylinder 1 in this way, a sign of oil leakage due to the life (deterioration over time) of the rod seal 11 is detected.

[Condition change processing]
Next, the change of the operating condition of the measuring unit 50 by the condition setting unit 83 will be described.

When the determination unit 84 detects the sign of oil leakage and determines that the operating condition of the measurement unit 50 is changed by the pressure sign detection, the comparison sign detection, and the time sign detection, the determination result is input to the condition setting unit 83. Based on the determination result of the determination unit 84, the condition setting unit 83 determines the mode of changing the operating condition, such as which operating condition is changed and how much. The condition setting unit 83 outputs a command signal for changing the operating conditions to the command unit 61 of the sensor controller 60 based on the determined mode of change.

When a sign of an oil leak is detected by the determination unit 84, the condition setting unit 83 measures so that the accuracy of detecting the oil leak by the fluid leak detection system 100 is improved, specifically, the operation frequency is increased. The operating conditions of the unit 50 are changed. The condition setting unit 83 outputs a command signal for executing at least one of shortening the sampling cycle SC, shortening the cycle interval CT, extending the measurement time Td, and reducing the transmission capacity Dc as a mode for changing the operating conditions. do.

The mode of change, such as which operating condition is changed to what extent, is determined based on the specification status of the hydraulic cylinder 1, the detection method for detecting a sign, the remaining battery level of the battery 54 of the measuring unit 50, and the like. The operating conditions such that the detection accuracy is relatively high, the more data is measured by the measuring unit 50, and the transmission frequency transmitted from the measuring unit 50 to the controller 80 also increases. Therefore, the power consumption in the measuring unit 50 is increased by that amount, and the life of the battery 54 is shortened. Therefore, by determining the mode of changing the operating conditions based on the remaining battery level of the battery 54, it is possible to detect oil leaks while improving the accuracy of detecting oil leaks and suppressing the decrease in the life of the battery 54. It can be further improved in efficiency.

When a command signal for changing the operating conditions is input from the condition setting unit 83 of the controller 80, the command unit 61 of the sensor controller 60 has the sensor unit 51 and / or the data storage unit 62 according to the mode of changing the operating conditions. A command signal is output to. As a result, the measuring unit 50 (sensor unit 51, data storage unit 62) operates under new operating conditions.

As described above, in the fluid leak detection system 100, the measuring unit 50 is operated under operating conditions where the operating frequency is relatively low in normal times when the risk of oil leakage is low, and when a sign of oil leakage is detected, the measuring unit 50 is operated. The detection accuracy can be improved by changing the operating conditions so that the operating frequency becomes high. That is, in the fluid leak detection system 100, the measuring unit 50 is operated under the optimum operating conditions depending on whether high detection accuracy is required or not, so that the detection of oil leaks is made more efficient.

Further, the measurement result of the measuring unit 50 may include a large value suddenly generated by noise or the like. Due to such a large value that occurs suddenly, there is a possibility of erroneous detection that the determination unit 84 determines that there is a sign of oil leakage even though there is no sign of oil leakage.

Therefore, the determination unit 84 continues to detect the sign even after the operating condition is changed by the condition setting unit 83. After changing the operating conditions, for example, when the state in which no sign of oil leakage is detected continues for a predetermined time, the determination unit 84 determines that there is no sign of oil leakage. When the determination unit 84 determines that there is no sign of oil leakage, the condition setting unit 83 outputs a command signal to the sensor controller 60 to change the operating condition of the measuring unit 50 to return to the original operating condition. .. As a result, even if there is an erroneous detection of a sign of an oil leak, it is possible to suppress the continuous collection of unnecessary data and improve the efficiency of detecting the oil leak by the fluid leak detection system 100.

Further, in the condition change process, when the sign of oil leakage is detected by the comparative sign detection, the operating conditions of both the first measurement unit 10a and the second measurement unit 10b may be changed, or only one of them may be changed. The operating conditions of may be changed.

For example, if the cycle interval CT of the sensor unit 51 of the first measurement unit 10a and the cycle interval CT of the sensor unit 51 of the second measurement unit 10b are different, the same time (in other words, the operation of the pair of hydraulic cylinders 1 is the same). ), Both data cannot be compared. Therefore, when the sign of oil leakage is detected by the comparative sign detection, it is desirable to change the operating conditions of both the first measurement unit 10a and the second measurement unit 10b in the same manner. According to this, since the operating conditions of the first measurement unit 10a and the second measurement unit 10b are maintained in the same state, the measurement results at the same time can be compared with each other. Therefore, it is possible to improve the detection accuracy of the sign of oil leakage in the comparative sign detection that is continued to suppress the false detection even after the operating condition is changed.

Further, for example, when a sign of an oil leak is detected by the comparative sign detection, the method of detecting the sign may be switched from the comparative sign detection to the pressure sign detection or the time sign detection. In this case, even if only one of the first measuring unit 10a and the second measuring unit 10b, in which the sign of oil leakage is detected, is changed under the operating conditions, the detection accuracy does not deteriorate.

Next, a modification of the present embodiment will be described.

In the above embodiment, as a method of acquiring the operating time of the hydraulic cylinder 1, the operating time of the hydraulic cylinder 1 is calculated from the temperature data measured by the sensor unit 51. On the other hand, as shown in FIG. 7, the controller 80 may further include an information acquisition unit 85 for acquiring operation information of the construction machine, and may acquire the operation time from the operation information of the construction machine or the hydraulic cylinder 1.

The information acquisition unit 85 acquires operation information regarding the running of the construction machine and the operating state of the hydraulic cylinder 1 from an ECU or the like that controls the operation of the construction machine. The operation information includes, for example, an on-off signal of an ignition switch, an operation signal generated when an operator operates an operation lever of a construction machine, a pilot signal of a control valve for controlling the operation of the hydraulic cylinder 1, and the like.

Explaining the case where the operation information is an on-off signal of the ignition switch, the information acquisition unit 85 accumulates the time during which the ignition switch is on from the reference time to the determination time. The information acquisition unit 85 calculates this cumulative time as the operating time of the hydraulic cylinder 1. Then, the determination unit 84 determines that there is a sign of oil leakage if the operating time is equal to or longer than the time threshold value, as in the case of the time sign detection. Even in this modified example, the same action and effect as the above-mentioned time sign detection can be obtained. It is desirable that this modification be performed in combination with pressure sign detection and / or comparative sign detection. According to this, since the sign of oil leakage is detected by two parameters having different properties of the measurement result of the sensor unit 51 and the operation information of the construction machine and the hydraulic cylinder 1, the detection accuracy of the sign can be improved. ..

Further, in the above embodiment, when a sign of oil leakage is detected in the hydraulic cylinder 1, the operating conditions of the measuring unit 50 provided in the hydraulic cylinder 1 are changed. On the other hand, when a sign of oil leakage is detected in one of the plurality of hydraulic cylinders 1 provided in the fluid pressure system 101, the operating conditions of the measuring unit 50 provided in the other hydraulic cylinder 1 are changed. You may.

Further, in the above embodiment, the sensor unit 51 measures the pressure as a state quantity used for detecting the leakage of the hydraulic oil. The leak determination unit 82 of the controller 80 determines the leakage of hydraulic oil based on the pressure measured by the sensor unit 51. On the other hand, the sensor unit 51 may measure a state amount other than the pressure, and the leak determination unit 82 may determine the leakage of hydraulic oil based on the state amount measured by the sensor unit 51. For example, the sensor unit 51 may measure the dielectric constant of the hydraulic oil guided to the detection space 20 as a state quantity, and the leak determination unit 82 may determine the leakage of the hydraulic oil based on the dielectric constant.

Further, in the above embodiment, the measuring unit 50 is configured to be capable of measuring the pressure and temperature of the detection space 20 by the sensor unit 51, which is a pressure temperature sensor capable of measuring both pressure and temperature. The oil leak is determined by the pressure measured by the measuring unit 50, and the sign of the oil leak is detected by at least one of the pressure and the temperature measured by the measuring unit 50. On the other hand, the measuring unit 50 has an arbitrary configuration as long as it can measure either the state quantity for detecting the oil leak and the pressure or the temperature for detecting the sign of the oil leak. be able to. In addition, "the measuring unit 50 measures the state quantity and either the pressure or the temperature" means to measure the parameters in which the determination of the oil leak and the detection of the sign of the oil leak can be performed. This is meant, and it is not essential for the measuring unit 50 to measure two different parameters. For example, when pressure is used to detect an oil leak and pressure is also used to detect a sign of an oil leak, the measuring unit 50 (sensor unit 51) may at least detect the pressure. That is, pressure may be used in common for detecting oil leaks and detecting signs of oil leaks. Furthermore, the state quantity for detecting an oil leak and the parameter for a sign of an oil leak do not mean that they are different from each other, and may be the same parameter (for example, pressure). On the other hand, when the temperature is used to detect the sign of the oil leak, the measuring unit 50 not only the temperature but also the state quantity for detecting the oil leak (pressure, dielectric constant described in the above modification, etc.). Is configured to measure.

According to the above embodiment, the following effects are obtained.

In the fluid leakage detection system 100, the operating conditions of the measuring unit 50 are changed according to the measurement result of the sensor unit 51 of the measuring unit 50. As a result, when the possibility of oil leakage is low, the operating condition is set to a relatively low operating condition, and when a sign of oil leakage is detected from the measurement results, the operating condition is set so that the operating frequency is high. It can be changed to improve the detection accuracy by the fluid leakage detection system 100. As described above, in the fluid leakage detection system 100, the measuring unit 50 can be operated under the optimum operating conditions depending on whether high detection accuracy is required or not. Therefore, the detection of oil leaks by the fluid leak detection system 100 is streamlined.

Further, in the fluid leakage detection system 100, the mode of changing the operating conditions of the measuring unit 50 is determined based on the remaining battery level of the battery 54 of the measuring unit 50. As a result, it is possible to further improve the efficiency of oil leak detection by the fluid leak detection system 100 by achieving both improvement in oil leak detection accuracy and suppression of deterioration of battery life.

Further, in the fluid leak detection system 100, even after the operating conditions of the measuring unit 50 are changed, the controller 80 continues to detect signs of oil leakage. After the operating conditions have been changed, if no signs of oil leakage are detected, the operating conditions will be returned to the state they were in before the change. In this way, the fluid leak detection system 100 detects the sign of oil leakage even after the operating condition is changed, and if the sign of oil leakage is erroneous detection, it controls to restore the operating condition. As a result, even if there is an erroneous detection of a sign of an oil leak, it is possible to suppress the continuous collection of unnecessary data and improve the efficiency of detecting the oil leak by the fluid leak detection system 100.

Hereinafter, the configurations, actions, and effects of the embodiments of the present invention will be collectively described.

In a hydraulic cylinder 1 having a piston rod 3 extending from the cylinder tube 2 and a cylinder head 5 through which the piston rod 3 is inserted and provided in the cylinder tube 2, the annular gap 8 between the piston rod 3 and the cylinder head 5 is passed through. The fluid leakage detection system 100 for detecting the leakage of the hydraulic oil is a measuring unit 10 provided in the hydraulic cylinder 1 and measuring the state amount of the hydraulic oil leaking through the annular gap 8 between the piston rod 3 and the cylinder head 5. A rod seal 11 provided on the cylinder head 5 and sealing an annular gap 8 between the piston rod 3 and the cylinder head 5 is provided with a controller 80 for acquiring the measurement result of the measurement unit 10. A detection space 20 in which the hydraulic oil leaking from the rod seal 11 is guided, and a measuring unit 50 that measures and outputs at least one of pressure and temperature as the state amount of the hydraulic oil in the detection space 20 under predetermined operating conditions. The measuring unit 50 is configured to be capable of measuring at least one of the pressure and the temperature in the detection space 20, and the controller 80 is a leak determination unit that determines the leakage of the hydraulic oil based on the pressure measured by the measuring unit 50. It has 82, a condition setting unit 83 for changing the operating conditions of the measuring unit 50, and a determination unit 84 for determining whether or not to change the operating conditions according to the measurement result of the measuring unit 50.

In this configuration, the operating conditions of the measuring unit 50 are changed according to the pressure measured by the measuring unit 50 of the measuring unit 10. As a result, for example, the operating conditions are set to be relatively low in normal times, and when a sign of oil leakage is detected from the measurement results, the operating conditions are changed so that the operating frequency is high, and fluid leakage occurs. The accuracy of detecting oil leaks by the detection system 100 can be improved. As described above, in the fluid leakage detection system 100, the measurement unit 10 can be operated under the optimum operating conditions depending on whether high detection accuracy is required or not. Therefore, the detection of oil leaks by the fluid leak detection system 100 is streamlined.

Further, in the fluid leakage detection system 100, the measuring unit 50 is configured to be able to measure the pressure, and the determining unit 84 operates by comparing the pressure data before and after in time series obtained from the measurement result of the measuring unit 50. Judge the change of conditions.

Further, in the fluid leakage detection system 100, the measuring unit 50 measures the pressure in each measurement cycle having a predetermined time length and being repeated at a predetermined time interval, and the determination unit 84 measures the pressure within the same measurement cycle. The change in operating conditions is judged by comparing the pressure data before and after the series.

Further, in the fluid leakage detection system 100, the measurement unit 50 measures the pressure in each measurement cycle having a predetermined time length and repeated at a predetermined time interval, and the determination unit 84 is input to the controller 80 this time. The change in operating conditions is determined by comparing the pressure data in the measurement cycle with the pressure data in the measurement cycle before the previous time.

Further, in the fluid leakage detection system 100, the determination unit 84 determines that the operating condition is changed if the difference between the pressure data before and after the time series is equal to or more than a predetermined difference threshold value.

In these configurations, signs of oil leaks can be detected by comparing pressure data back and forth over time.

Further, the fluid leakage detection system 100 includes, as the measurement unit 10, a first measurement unit 10a and a second measurement unit 10b provided in a pair of hydraulic cylinders 1 for driving the same drive target, respectively, and the determination unit 84 has a determination unit 84. The measurement result of the first measurement unit 10a and the measurement result of the second measurement unit 10b are compared.

In this configuration, by comparing the pressure data of a pair of hydraulic cylinders 1 that drive the same drive target, it is possible to detect a sign of accidental oil leakage that has occurred in one of the hydraulic cylinders 1. ..

Further, in the fluid leakage detection system 100, when the determination unit 84 determines that the operating conditions are changed, the operating conditions of the first measurement unit 10a and the second measurement unit 10b are changed to the same conditions.

In this configuration, the operating conditions of the first measuring unit 10a and the second measuring unit 10b are changed to the same conditions, so that even after the operating conditions are changed, the measurement of each other is performed in the same operating state of the hydraulic cylinder 1. The results can be compared. This facilitates comparison of the measurement results of the first measurement unit 10a and the second measurement unit 10b.

Further, in the fluid leakage detection system 100, the determination unit 84 calculates the operating time of the hydraulic cylinder 1 and determines the change of the operating condition based on the operating time.

Further, in the fluid leakage detection system 100, the measurement unit 10 is configured to be capable of measuring the temperature, and the determination unit 84 determines the operating time based on the measurement time Td at which the measurement unit 10 measures the temperature equal to or higher than a predetermined temperature threshold. calculate.

With these configurations, signs of oil leakage based on the life of the rod seal 11 can be detected.

Further, in the fluid leakage detection system 100, the controller 80 has an information acquisition unit 85 for acquiring operation information of the hydraulic cylinder 1 or a fluid pressure drive machine (construction machine) including the hydraulic cylinder 1, and the determination unit 84 has a determination unit 84. The operating time is calculated based on the operation information acquired by the information acquisition unit 85.

Further, in the present embodiment, the hydraulic pressure drive machine is a construction machine, and the determination unit 84 acquires an on-off signal of the ignition switch for starting the construction machine as operation information, and the ignition switch is on. The operating time is calculated based on the cumulative time.

In these configurations, in addition to the measurement result of the sensor unit 51, it is possible to detect a sign of oil leakage based on the life of the rod seal 11 based on the operation information of the hydraulic cylinder 1 or the fluid pressure drive machine (construction machine). , It is possible to improve the detection accuracy of oil leaks.

Further, in the fluid leakage detection system 100, the measurement unit 10 measures at least one of pressure and temperature by a predetermined sampling cycle SC for each measurement cycle having a predetermined time length and repeated at predetermined time intervals. When at least one of the pressure and the temperature is measured by the transmission capacity Dc which is a predetermined data capacity, the measurement result is transmitted to the controller 80, and the condition setting unit 83 repeats the time length of the measurement cycle and the measurement cycle as operating conditions. At least one of the time interval, the sampling cycle SC, and the transmission capacity Dc is changed.

Further, in the fluid leakage detection system 100, the measurement unit 10 has a battery 54 as a power source, and the condition setting unit 83 determines an aspect of changing the operating conditions based on the remaining battery level of the battery 54.

In this configuration, it is possible to improve the accuracy of detecting oil leakage and suppress the decrease in the life of the battery 54 at the same time.

Although the embodiments of the present invention have been described above, the above embodiments are only a part of the application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiments. do not have.

1 ... Hydraulic cylinder (fluid pressure cylinder), 2 ... Cylinder tube, 3 ... Piston rod, 5 ... Cylinder head, 8 ... Circular gap (gap), 10 ... Measuring unit, 10a ... First measuring unit 10b ... Second measuring unit , 11 ... Rod seal, 50 ... Measurement unit, 54 ... Battery, 80 ... Controller, 83 ... Condition setting unit, 84 ... Judgment unit, 85 ... Information acquisition unit, 100 ... Fluid leak detection system

Claims (11)

Leakage of working fluid through a gap between the piston rod and the cylinder head in a fluid pressure cylinder having a piston rod extending from the cylinder tube and a cylinder head through which the piston rod is inserted and provided in the cylinder tube. A fluid leak detection system for detecting
A measuring unit provided in the fluid pressure cylinder and measuring the state amount of the working fluid leaking through the gap between the piston rod and the cylinder head.
A controller for acquiring the measurement result of the measurement unit is provided.
The measuring unit is
A rod seal provided on the cylinder head and sealing the gap between the piston rod and the cylinder head,
The detection space where the working fluid leaking from the rod seal is guided,
It has a measuring unit that performs measurement of the state quantity of the working fluid in the detection space and output of the measurement result under predetermined operating conditions.
The measuring unit is configured to be capable of measuring at least one of the pressure and the temperature in the detection space.
The controller
A leak determination unit that determines leakage of the working fluid based on the state quantity measured by the measurement unit, and a leak determination unit.
A condition setting unit that sets the operating conditions of the measurement unit, and a condition setting unit.
It has a determination unit for determining whether or not to change the operating conditions according to at least one of the pressure and the temperature measured by the measurement unit.
The measuring unit is configured to be able to measure pressure.
The determination unit is a fluid leakage detection system characterized in that it determines a change in operating conditions by comparing pressure data obtained from the measurement results of the measurement unit in time series . The measuring unit measures the pressure every measurement cycle having a predetermined time length and being repeated at a predetermined time interval.
The fluid leakage detection system according to claim 1 , wherein the determination unit compares the pressure data before and after in time series within the same measurement cycle to determine a change in the operating conditions. .. The measuring unit measures the pressure every measurement cycle having a predetermined time length and being repeated at a predetermined time interval.
The determination unit compares the pressure data in the current measurement cycle input to the controller with the pressure data in the measurement cycle before the previous time, and determines a change in the operating conditions. The fluid leak detection system according to claim 1 or 2 . 1 . The described fluid leak detection system. Leakage of working fluid through a gap between the piston rod and the cylinder head in a fluid pressure cylinder having a piston rod extending from the cylinder tube and a cylinder head through which the piston rod is inserted and provided in the cylinder tube. A fluid leak detection system for detecting
A measuring unit provided in the fluid pressure cylinder and measuring the state amount of the working fluid leaking through the gap between the piston rod and the cylinder head.
A controller for acquiring the measurement result of the measurement unit is provided.
The measuring unit is
A rod seal provided on the cylinder head and sealing the gap between the piston rod and the cylinder head,
The detection space where the working fluid leaking from the rod seal is guided,
It has a measuring unit that performs measurement of the state quantity of the working fluid in the detection space and output of the measurement result under predetermined operating conditions.
The measuring unit is configured to be capable of measuring at least one of the pressure and the temperature in the detection space.
The controller
A leak determination unit that determines leakage of the working fluid based on the state quantity measured by the measurement unit, and a leak determination unit.
A condition setting unit that sets the operating conditions of the measurement unit, and a condition setting unit.
It has a determination unit for determining whether or not to change the operating conditions according to at least one of the pressure and the temperature measured by the measurement unit.
The measuring unit includes a first measuring unit and a second measuring unit provided for each of the pair of fluid pressure cylinders that drive the same driving object.
The determination unit is a fluid leakage detection system characterized in that the measurement result of the first measurement unit and the measurement result of the second measurement unit are compared. When the determination unit determines that the operating conditions are to be changed, the operating conditions of the measuring unit in each of the first measuring unit and the second measuring unit are changed to the same conditions. The fluid leak detection system according to claim 5 . Leakage of working fluid through a gap between the piston rod and the cylinder head in a fluid pressure cylinder having a piston rod extending from the cylinder tube and a cylinder head through which the piston rod is inserted and provided in the cylinder tube. A fluid leak detection system for detecting
A measuring unit provided in the fluid pressure cylinder and measuring the state amount of the working fluid leaking through the gap between the piston rod and the cylinder head.
A controller for acquiring the measurement result of the measurement unit is provided.
The measuring unit is
A rod seal provided on the cylinder head and sealing the gap between the piston rod and the cylinder head,
The detection space where the working fluid leaking from the rod seal is guided,
It has a measuring unit that performs measurement of the state quantity of the working fluid in the detection space and output of the measurement result under predetermined operating conditions.
The measuring unit is configured to be capable of measuring at least one of the pressure and the temperature in the detection space.
The controller
A leak determination unit that determines leakage of the working fluid based on the state quantity measured by the measurement unit, and a leak determination unit.
A condition setting unit that sets the operating conditions of the measurement unit, and a condition setting unit.
It has a determination unit for determining whether or not to change the operating conditions according to at least one of the pressure and the temperature measured by the measurement unit.
The measuring unit is configured to be capable of measuring temperature.
The determination unit calculates the operating time of the fluid pressure cylinder based on the measurement time when the measuring unit measures a temperature equal to or higher than a predetermined temperature threshold, and determines the change of the operating condition based on the operating time. Featuring fluid leak detection system. Leakage of working fluid through a gap between the piston rod and the cylinder head in a fluid pressure cylinder having a piston rod extending from the cylinder tube and a cylinder head through which the piston rod is inserted and provided in the cylinder tube. A fluid leak detection system for detecting
A measuring unit provided in the fluid pressure cylinder and measuring the state amount of the working fluid leaking through the gap between the piston rod and the cylinder head.
A controller for acquiring the measurement result of the measurement unit is provided.
The measuring unit is
A rod seal provided on the cylinder head and sealing the gap between the piston rod and the cylinder head,
The detection space where the working fluid leaking from the rod seal is guided,
It has a measuring unit that performs measurement of the state quantity of the working fluid in the detection space and output of the measurement result under predetermined operating conditions.
The measuring unit is configured to be capable of measuring at least one of the pressure and the temperature in the detection space.
The controller
A leak determination unit that determines leakage of the working fluid based on the state quantity measured by the measurement unit, and a leak determination unit.
A condition setting unit that sets the operating conditions of the measurement unit, and a condition setting unit.
It has a determination unit for determining whether or not to change the operating conditions according to at least one of the pressure and the temperature measured by the measurement unit.
The controller has an information acquisition unit that acquires operation information of the fluid pressure cylinder or the fluid pressure drive machine including the fluid pressure cylinder.
The determination unit calculates the operating time of the fluid pressure cylinder based on the operation information acquired by the information acquisition unit, and determines the change of the operating condition based on the operating time. system. The fluid pressure drive machine is a construction machine and
The determination unit acquires the on-off signal of the ignition switch for starting the construction machine as the operation information, and calculates the operating time based on the cumulative time during which the ignition switch is turned on. The fluid leak detection system according to claim 8 . Leakage of working fluid through a gap between the piston rod and the cylinder head in a fluid pressure cylinder having a piston rod extending from the cylinder tube and a cylinder head through which the piston rod is inserted and provided in the cylinder tube. A fluid leak detection system for detecting
A measuring unit provided in the fluid pressure cylinder and measuring the state amount of the working fluid leaking through the gap between the piston rod and the cylinder head.
A controller for acquiring the measurement result of the measurement unit is provided.
The measuring unit is
A rod seal provided on the cylinder head and sealing the gap between the piston rod and the cylinder head,
The detection space where the working fluid leaking from the rod seal is guided,
It has a measuring unit that performs measurement of the state quantity of the working fluid in the detection space and output of the measurement result under predetermined operating conditions.
The measuring unit is configured to be capable of measuring at least one of the pressure and the temperature in the detection space.
The controller
A leak determination unit that determines leakage of the working fluid based on the state quantity measured by the measurement unit, and a leak determination unit.
A condition setting unit that sets the operating conditions of the measurement unit, and a condition setting unit.
It has a determination unit for determining whether or not to change the operating conditions according to at least one of the pressure and the temperature measured by the measurement unit.
The measuring unit measures at least one of pressure and temperature by a predetermined sampling cycle for each measurement cycle having a predetermined time length and repeated at a predetermined time interval, and only the transmission capacity as a predetermined data capacity. When at least one of pressure and temperature is measured, the measurement result is transmitted to the controller.
The condition setting unit changes, as the operating condition, at least one of the time length of the measurement cycle, the time interval in which the measurement cycle is repeated, the sampling cycle, and the transmission capacity. Leak detection system. The measuring unit has a battery as a power source.
The fluid leakage detection system according to any one of claims 1 to 10 , wherein the condition setting unit determines an aspect of changing the operating condition based on the remaining battery level of the battery.

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