JP7032999B2 - 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. Therefore, it is difficult to set the optimum operating conditions for the detector.

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, which is provided in a fluid pressure cylinder and acquires a measurement unit for measuring the state amount of working fluid leaking through a gap between a piston rod and a cylinder head, and a measurement result of the measurement unit. The measuring unit is provided with a rod seal provided in the cylinder head to seal the gap between the piston rod and the cylinder head, and a detection space in which the working fluid leaking from the rod seal is guided, and a detection space. It has a measuring unit that measures the state amount of the working fluid and outputs the measurement result under predetermined operating conditions, and the controller has a signal acquisition unit that acquires a change signal input from the outside and a measuring unit. On the other hand, it has a condition setting unit that outputs a command signal to command the operating condition and changes the operating condition, and the command signal includes a first command signal that operates the measuring unit under the first operating condition and a first. The condition setting unit includes a second command signal for operating the measuring unit under a second operating condition, which is more frequently operated than the operating condition, and the condition setting unit receives a first command signal or a first command signal according to a change signal acquired by the signal acquisition unit. 2 The command signal is output , the timer outputs the change signal when a predetermined time elapses from the output of the second command signal, and the condition setting unit outputs the first command signal when the signal acquisition unit acquires the change signal from the timer. Output.

The present invention is a fluid leakage detection system, which is provided in a fluid pressure cylinder and acquires a measurement unit for measuring the state amount of working fluid leaking through a gap between a piston rod and a cylinder head, and a measurement result of the measurement unit. The measuring unit is provided with a rod seal provided in the cylinder head to seal the gap between the piston rod and the cylinder head, and a detection space in which the working fluid leaking from the rod seal is guided, and a detection space. It has a measuring unit that measures the state amount of the working fluid and outputs the measurement result under predetermined operating conditions, and the controller has a signal acquisition unit that acquires a change signal input from the outside and a measuring unit. On the other hand, it has a condition setting unit that outputs a command signal to command the operating condition and changes the operating condition, and the command signal includes a first command signal that operates the measuring unit under the first operating condition and a first. The condition setting unit includes a second command signal for operating the measuring unit under a second operating condition, which is more frequently operated than the operating condition, and the condition setting unit receives a first command signal or a first command signal according to a change signal acquired by the signal acquisition unit. 2 The command signal is output, the measuring unit is configured to be able to measure the temperature of the detection space, and the controller further has a temperature determination unit that outputs a return signal to the signal acquisition unit based on the temperature measured by the measuring unit. When the signal acquisition unit acquires the return signal from the temperature determination unit, the condition setting unit outputs the first command signal.

In these inventions, by inputting a change signal to the condition setting unit from the outside, the operating condition of the measuring unit is changed between the first operating condition in which the operating frequency is relatively low and the second operating condition in which the operating frequency is relatively high. Switch. Therefore, the measuring unit can be operated under the optimum operating conditions according to the situation. Further, even if the operator forgets to return to the first operating condition after setting the measuring unit as the second operating condition, the operating condition of the measuring unit is set to the first operating condition by the signal from the timer or the temperature determination unit. It is changed to a condition. Therefore, it is possible to suppress the collection of unnecessary data and the power consumption.

The present invention is a fluid leakage detection system, which is provided in a fluid pressure cylinder and acquires a measurement unit for measuring the state amount of working fluid leaking through a gap between a piston rod and a cylinder head, and a measurement result of the measurement unit. The measuring unit is provided with a rod seal provided in the cylinder head to seal the gap between the piston rod and the cylinder head, and a detection space in which the working fluid leaking from the rod seal is guided, and a detection space. It has a measuring unit that measures the state amount of the working fluid and outputs the measurement result under predetermined operating conditions, and the controller has a signal acquisition unit that acquires a change signal input from the outside and a measuring unit. On the other hand, it has a condition setting unit that outputs a command signal to command the operating condition and changes the operating condition, and the command signal includes a first command signal that operates the measuring unit under the first operating condition and a first. The condition setting unit includes a second command signal for operating the measuring unit under a second operating condition, which is more frequently operated than the operating condition, and the condition setting unit receives a first command signal or a first command signal according to a change signal acquired by the signal acquisition unit. 2 A command signal is output, and the measuring unit measures the state quantity by a method common to the first operating condition and the second operating condition, has a predetermined measurement time, and repeats every measurement cycle at a predetermined time interval. , The state amount is measured by a predetermined sampling cycle, and when the accumulated data amount reaches a predetermined transmission capacity, the accumulated measurement result is transmitted to the controller and changed by the condition setting unit. The operating conditions to be performed are characterized by including at least one of a measurement time of a measurement cycle, a sampling cycle, and a transmission capacity.

The present invention is a fluid leakage detection system, which is provided in a fluid pressure cylinder and acquires a measurement unit for measuring the state amount of working fluid leaking through a gap between a piston rod and a cylinder head, and a measurement result of the measurement unit. The measuring unit is provided with a rod seal provided on the cylinder head to seal the gap between the piston rod and the cylinder head, and a working fluid leaking from the rod seal. It has a detection space to which it is guided, and a measurement unit that measures the state amount of the working fluid in the detection space and outputs the measurement result under predetermined operating conditions, and the controller receives a change signal input from the outside. It has a signal acquisition unit to acquire and a condition setting unit that outputs a command signal to command the measurement unit to change the operating condition, and the command signal includes a measurement unit under the first operating condition. The condition setting unit includes a first command signal to be operated and a second command signal to operate the measurement unit under the second operating condition, which is more frequently operated than the first operating condition, and the condition setting unit is a change signal acquired by the signal acquisition unit. The first command signal or the second command signal is output according to the above, the measuring unit measures the state quantity by a method common to the first operating condition and the second operating condition, and the signal acquisition unit is operated by the operator. Acquires a change signal according to the operation of the operation unit.

In the present invention, the operator can change the operating conditions of the measuring unit at any timing.

The present invention is characterized in that the measuring unit accumulates the measurement result of measuring the state quantity, and when the accumulated data amount reaches a predetermined data amount, the accumulated measurement result is transmitted to the controller.

In the present invention, under the first operating condition, the measuring unit intermittently measures the state quantity of the working fluid in the detection space, and under the second operating condition, the measuring unit continuously measures the state quantity of the working fluid in the detection space. It is characterized by measuring.

In the present invention, under the first operating condition, the measuring unit intermittently transmits the measurement result to the controller, and under the second operating condition, the measuring unit continuously transmits the measurement result to the controller.

In these inventions, by setting the operating condition of the measuring unit as the second operating condition having a high operating frequency, the detection accuracy of fluid leakage can be greatly improved.

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 1st operation condition of the measurement part 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. show. It is a block diagram which shows the control unit which concerns on the modification 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.

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.

The fluid leakage detection system 100 detects the occurrence of oil leakage (fluid leakage) in which 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 the hydraulic cylinder 1. ..

As shown mainly in FIGS. 1 and 3, the fluid leakage 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”. A measurement unit 10 that measures the amount of hydraulic oil leaking from the gap 8), a control unit 70 that determines the occurrence of oil leakage in the hydraulic cylinder 1 based on the measurement results of the measurement unit 10, and an operator. It includes an operation unit 90 (see FIG. 5) to be operated.

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 partitions the detection space 20 together with the rod seal 11. 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. The measuring unit 50 measures the pressure and outputs the measurement result according to the operating frequency based on the operating conditions. The operation frequency includes a measurement frequency in which the measuring unit 50 measures the pressure 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 is a sensor unit 51 which is a pressure temperature sensor capable of measuring pressure and temperature, and a sensor controller which outputs a command signal to the sensor unit 51 and acquires the measurement result of the sensor unit 51. It has 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. ..

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 (measurement frequency) 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 of 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. It includes a controller 80 for transmitting and receiving signals to and from the controller 80, and a timer 75 for measuring time.

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 sets 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 to be set, and a signal acquisition unit 84 to acquire a change signal input from the outside.

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 leak determination unit 82.

The leak determination unit 82 determines whether or not an oil leak has occurred in the hydraulic cylinder 1 based on the pressure as the state quantity measured by the sensor unit 51 of the measurement unit 10. The leak determination unit 82 determines the occurrence of an oil leak each time the measurement result of the measurement unit 10 is input.

The condition setting unit 83 outputs a command signal for commanding the operating conditions of the measurement unit 50 to the command unit 61 of the sensor controller 60 through the first and second communication units 52 and 71. Upon receiving the command signal from the condition setting unit 83, the command unit 61 of the sensor controller 60 outputs a signal to the sensor unit 51 and / or the data storage unit 62 so as to operate under the operating conditions corresponding to the command signal.

Specifically, the condition setting unit 83 uses the first command signal to operate the measuring unit 50 under the first operating condition and the measuring unit 50 under the second operating condition, which has a higher operating frequency than the first operating condition, as command signals. The second command signal to operate is output.

The signal acquisition unit 84 acquires a change signal output when the operator operates the operation unit 90. The condition setting unit 83 outputs the first command signal or the second command signal to the command unit 61 of the sensor controller 60 according to the change signal acquired by the signal acquisition unit 84.

The timer 75 starts measuring the time when it receives the start signal, and outputs the end signal when the predetermined time elapses. More specifically, the timer 75 measures the time during which the measuring unit 50 is operating under the second operating condition.

The operation unit 90 is an operation button arranged in the driver's cab and can be operated by an operator. The operation unit 90 has a first button 91 for operating the measurement unit 50 under the first operating condition, and a second button 92 for operating the measurement unit 50 under the second operating condition. When the first button 91 is pressed (operated) by the operator, the first change signal is output to the controller 80 as a change signal from the operation unit 90. When the signal acquisition unit 84 acquires the first change signal, the condition setting unit 83 outputs the first command signal. Similarly, when the second button 92 is pressed by the operator, the second change signal is output from the operation unit 90 to the controller 80 as a change signal. When the signal acquisition unit 84 acquires the second change signal, the condition setting unit 83 outputs the second command signal.

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 measuring unit 50 is configured to be operable by a first operating condition having a relatively low operating frequency and a second operating condition having a relatively high operating frequency.

Under the first operating condition, 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. When the stored data (measurement result of the sensor unit 51 and the remaining battery level of the battery 54) reaches a predetermined data capacity, the data storage unit 62 transmits the data stored in the control unit 70 through the first communication unit 52. do. 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”.

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, and shows the case where the measurement unit 50 operates under the first operating condition. 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 detection, 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.

As described above, under the first operating condition, the sensor unit 51 does not constantly (continuously) measure the pressure and temperature in the detection space 20, but intermittently measures each measurement cycle. 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. Under the first operating condition, the measurement by the sensor unit 51 and the transmission of the measurement result from the data storage unit 62 are executed intermittently, so that the power consumption can be reduced.

Under the second operating condition, the sensor unit 51 measures the pressure and temperature with the maximum sampling period as a sensor. That is, in the second operating condition, the measurement cycle is not set as in the first operating condition, and the pressure and temperature are continuously measured. In other words, in the second operating condition, the measurement time in the first operating condition is set to be the same as the cycle cycle (measurement time = cycle cycle), and the condition is set so as not to be in the standby state. be. Under the second operating condition, each time the pressure and temperature are measured according to the sampling cycle, the measurement result is transmitted to the control unit 70 through the data storage unit 62. As described above, the second operating condition is that the measurement of the pressure and the temperature by the sensor unit 51 and the transmission of the measurement result are always (continuously) executed.

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 and temperature in the detection space 20 are 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 results. , Oil leakage in the hydraulic cylinder 1 is detected. In addition, in this specification, "deterioration" of a 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. Further, since the controller 80 determines the occurrence of oil leakage each time the measurement result of the measuring unit 50 is input, 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, as in the second condition, the higher the operation frequency of the measuring unit 50 (measurement frequency of the sensor unit 51 and transmission frequency from the data storage unit 62), the higher the accuracy of oil leakage detection by the fluid leakage detection system 100. improves.

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. Therefore, if the operation frequency of the measuring unit 50 is low as in the first operating condition, the accuracy of detecting oil leakage is lowered, 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, 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, so that the operation frequency is higher than that of the first operating condition. Two operating conditions are preferred. On the other hand, assuming that the operating condition of the measuring unit 50 is the second operating condition having a relatively high operating frequency, unnecessary data such as data in a state where the construction machine or the hydraulic cylinder 1 is not operating is collected. There is. 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, in a normal state, the measuring unit 50 is operated under the first operating condition in which the measurement of the pressure and the temperature and the transmission of the measurement result are intermittently executed. As a result, it is possible to secure the accuracy of detecting oil leakage and suppress the power consumption of the battery 54 at the same time.

On the other hand, for example, when a sign of an oil leak appears in the hydraulic cylinder 1 or when an oil leak is suspected, an inspection work is performed to operate the hydraulic cylinder 1 to check whether or not an oil leak has occurred. May be done. When performing such an inspection work, if the measuring unit 50 operates intermittently, data cannot be efficiently collected. That is, when the measuring unit 50 operates intermittently, the inspection work cannot be performed until the next measurement cycle, so that the occurrence of oil leakage in the hydraulic cylinder 1 cannot be immediately inspected.

Therefore, the fluid leak detection system 100 is configured so that the operating conditions of the measuring unit 50 can be changed at a timing desired by the operator.

When performing the inspection work as described above, the second button 92 of the operation unit 90 is pressed by the operator. As a result, the second change signal is output from the operation unit 90, and when the signal acquisition unit 84 of the controller 80 acquires the second change signal, the second command signal is output from the condition setting unit 83 to the command unit 61 of the sensor controller 60. Will be done. As a result, the operating condition of the measuring unit 50 is switched from the first operating condition in the normal state to the second operating condition.

Further, the condition setting unit 83 outputs a start signal to the timer 75 at the same time as outputting the second command signal. The timer 75 starts measuring the time when the start signal is acquired. That is, the timer 75 measures the operating time after the measuring unit 50 switches to the second operating condition.

When the first button 91 is pressed by the operator while the measuring unit 50 is operating under the second operating condition, the first change signal is output from the operation unit 90 and input to the signal acquisition unit 84. As a result, the condition setting unit 83 outputs the first command signal to the command unit 61, and the operating condition of the measuring unit 50 is switched from the second operating condition to the first operating condition.

Further, the timer 75 outputs an end signal as a change signal when a predetermined time elapses after the measuring unit 50 switches to the second operating condition. When the signal acquisition unit 84 acquires the end signal, the condition setting unit 83 outputs the first command signal. As a result, even if the operator forgets to press the first button 91 to end the operation of the measuring unit 50 under the second operating condition at the end of the inspection work, the operating condition is automatically set to the first operation. Switch to the condition. Therefore, even after the inspection work is completed, it is prevented from continuing to operate under the second operating condition where the operation frequency is high, and unnecessary data collection and power consumption are suppressed.

As described above, in the fluid leak detection system 100, due to the operation of the operation unit 90 by the operator, the operation condition of the measurement unit 50 is the first operation condition in which the operation frequency is relatively low and the operation frequency in which the operation unit is relatively high. It can be switched according to 2 operating conditions. Therefore, it is possible to improve the efficiency of detecting oil leaks.

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

In the above embodiment, the change signal is output by the operation of the operation unit 90 by the operator, and the operating conditions of the measurement unit 50 are switched. On the other hand, the change signal may be output by another method. The change signal is externally input to the controller 80, for example, an on signal of the ignition switch of the construction machine, a signal output from the timer 75, a signal output from the operation lever for operating the construction machine (hydraulic cylinder 1), and the like. It can be any signal.

Further, in the above embodiment, when a predetermined time elapses after the measuring unit 50 switches to the second operating condition, the timer 75 outputs an end signal as a change signal, and the condition setting unit 83 outputs the first command signal. Output. As a result, even if the operator forgets to press the first button 91 to end the operation of the measuring unit 50 under the second operating condition at the end of the inspection work, the operating condition is automatically set to the first operation. Switch to the condition. On the other hand, as shown in FIG. 7, instead of the timer 75, or in addition to the timer 75, the controller is configured to exert the function of preventing forgetting to return the operating conditions (automatic switching function) after the inspection work is completed. 80 may have a temperature determination unit 85. The temperature determination unit 85 outputs a return signal to the signal acquisition unit 84 based on the temperature measured by the sensor unit 51, and sets the operating condition of the measuring unit 50 as the first operating condition. If the hydraulic cylinder 1 continues to be inoperable after the inspection work is completed, the temperature of the detection space 20 drops. Therefore, when the temperature measured by the sensor unit 51 becomes less than a predetermined temperature threshold value, the temperature determination unit 85 determines that the inspection work is completed and the hydraulic cylinder 1 is not operating, and outputs a return signal. When the signal acquisition unit 84 acquires the return signal, the condition setting unit 83 outputs the first command signal. According to such a modification, even if it is forgotten to return to the first operating condition after the inspection work for operating the hydraulic cylinder 1 with the operating condition of the measuring unit 50 as the second operating condition is completed, the temperature drops. The operating condition of the measuring unit 50 is automatically changed to the first operating condition. Therefore, even after the inspection work is completed, it is prevented from continuing to operate under the second operating condition where the operation frequency is high, and unnecessary data collection and power consumption are suppressed.

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 sensor unit 51 is a pressure temperature sensor capable of detecting both pressure and temperature. On the other hand, the sensor unit 51 may be a pressure sensor that merely measures the pressure.

Further, in the above embodiment, as the second operating condition, the measurement by the sensor unit 51 and the output of the measurement result from the measurement unit 50 to the controller 80 are continuously performed, respectively. On the other hand, either one of the measurement by the sensor unit 51 and the output of the measurement result may be continuously performed, and the other may be performed intermittently. Further, as long as the operation frequency is higher than that of the first operating condition, the second operating condition may be one in which the measurement by the measurement sensor and the output of the measurement result are intermittently executed. The high frequency of operation means that the amount of data acquired by the controller 80 per unit time is large.

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

In the fluid leak detection system 100, the operating conditions of the measuring unit 50 are the first operating condition having a relatively low operating frequency and the second operating condition having a relatively high operating frequency due to the operation of the operating unit 90 by the operator. Can be switched with. As a result, the operating conditions of the measuring unit 50 can be changed at a desired timing, so that the detection of oil leakage is made more efficient.

Further, in the fluid leakage detection system 100, the second operating condition is to continuously execute the measurement of pressure and temperature by the measuring unit 50 and the output of the measurement result. Therefore, by setting the operating condition of the measuring unit 50 as the second operating condition, the accuracy of detecting oil leakage can be greatly improved.

Further, in the fluid leakage detection system 100, when the time for the measuring unit 50 to operate under the second operating condition reaches a predetermined time, the timer 75 outputs a change signal with the operating condition as the first operating condition. As a result, even if the operator forgets to return from the second operating condition to the first operating condition, the second operating condition having a relatively high operating frequency does not continue. Therefore, it is possible to suppress the collection of unnecessary data and power consumption due to the operator forgetting to operate.

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 to which the hydraulic oil leaking from the rod seal 11 is guided, and a measuring unit 50 for measuring the temperature of the hydraulic oil in the detection space 20 and outputting the measurement result under predetermined operating conditions. The controller 80 includes a signal acquisition unit 84 that acquires a change signal input from the outside, and a condition setting unit 83 that outputs a command signal for instructing the operation condition to the measurement unit 50 to change the operation condition. The command signals include a first command signal that operates the measuring unit 50 under the first operating condition, and a second command signal that operates the measuring unit 50 under the second operating condition, which has a higher operating frequency than the first operating condition. , And the condition setting unit 83 outputs the first command signal or the second command signal according to the change signal acquired by the signal acquisition unit 84.

In this configuration, by inputting a change signal to the condition setting unit 83 from the outside, the operating condition of the measuring unit 50 is between the first operating condition having a relatively low operating frequency and the second operating condition having a relatively high operating frequency. Is switched. Therefore, the measuring unit 10 can be operated under the optimum operating conditions according to the situation, and the oil leak detection by the fluid leak detecting system 100 is made efficient.

Further, in the fluid leak detection system 100, under the first operating condition, the measuring unit 50 intermittently measures the pressure and temperature of the hydraulic oil in the detection space 20, and under the second operating condition, the measuring unit 50 continuously measures. The state amount of the hydraulic oil in the detection space 20 is measured.

Further, in the fluid leakage detection system 100, under the first operating condition, the measuring unit 50 intermittently transmits the measurement result to the controller 80, and under the second operating condition, the measuring unit 50 continuously transmits the measurement result to the controller 80. Send to 80.

In these configurations, by setting the operating condition of the measuring unit 50 as the second operating condition, the accuracy of detecting oil leakage can be greatly improved.

Further, the fluid leakage detection system 100 further includes an operation unit 90 operated by the operator, and the signal acquisition unit 84 acquires a change signal according to the operation of the operation unit 90 by the operator.

In this configuration, the operator can change the operating conditions of the measuring unit 50 at an arbitrary timing, so that the detection of oil leakage can be further made more efficient.

Further, the fluid leakage detection system 100 further includes a timer 75 for measuring the time, the timer 75 outputs a change signal when a predetermined time has elapsed from the output of the second command signal, and the condition setting unit 83 is a signal acquisition unit. When the 84 acquires the change signal from the timer 75, it outputs the first command signal.

Further, in the fluid leak detection system 100, the measuring unit 50 is configured to be able to measure the temperature of the detection space 20, and the controller 80 outputs a return signal to the signal acquisition unit 84 based on the temperature measured by the measuring unit 50. Further having a temperature determination unit 85, the condition setting unit 83 outputs a first command signal when the signal acquisition unit 84 acquires a return signal from the temperature determination unit 85.

In these configurations, even if the operator forgets to return to the first operating condition after setting the measuring unit 50 to the second operating condition, the measuring unit 50 receives a signal from the timer 75 or the temperature determination unit 85. The operating condition of is changed to the first operating condition. Therefore, it is possible to suppress the collection of unnecessary data and the power consumption.

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, 20 ... Detection space, 50 ... Measuring unit, 54 ... Battery, 75 ... timer, 80 ... controller, 83 ... condition setting unit, 84 ... signal acquisition unit, 85 ... temperature determination unit, 90 ... operation unit, 100 ... fluid leak detection system

Claims (7)

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. Is 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 that acquires the measurement results of the measurement unit and
Equipped with a timer to measure time,
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, and
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 controller
A signal acquisition unit that acquires change signals input from the outside,
It has a condition setting unit that outputs a command signal for instructing the operating condition to the measuring unit and changes the operating condition.
The command signal is
The first command signal that operates the measuring unit under the first operating condition,
A second command signal for operating the measuring unit under a second operating condition, which has a higher operating frequency than the first operating condition, is included.
The condition setting unit outputs the first command signal or the second command signal in response to the change signal acquired by the signal acquisition unit.
The timer outputs the change signal when a predetermined time elapses from the output of the second command signal.
The condition setting unit is a fluid leakage detection system that outputs the first command signal when the signal acquisition unit acquires the change signal from the timer. 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, and
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 controller
A signal acquisition unit that acquires change signals input from the outside,
It has a condition setting unit that outputs a command signal for instructing the operating condition to the measuring unit and changes the operating condition.
The command signal is
The first command signal that operates the measuring unit under the first operating condition,
A second command signal for operating the measuring unit under a second operating condition, which has a higher operating frequency than the first operating condition, is included.
The condition setting unit outputs the first command signal or the second command signal in response to the change signal acquired by the signal acquisition unit.
The measuring unit is configured to be capable of measuring the temperature of the detection space.
The controller further has a temperature determination unit that outputs a return signal to the signal acquisition unit based on the temperature measured by the measurement unit.
The condition setting unit is a fluid leakage detection system characterized in that when the signal acquisition unit acquires the return signal from the temperature determination unit, the first command signal is output. 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, and
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 controller
A signal acquisition unit that acquires change signals input from the outside,
It has a condition setting unit that outputs a command signal for instructing the operating condition to the measuring unit and changes the operating condition.
The command signal is
The first command signal that operates the measuring unit under the first operating condition,
A second command signal for operating the measuring unit under a second operating condition, which has a higher operating frequency than the first operating condition, is included.
The condition setting unit outputs the first command signal or the second command signal in response to the change signal acquired by the signal acquisition unit.
The measuring unit measures the state quantity by a method common to the first operating condition and the second operating condition, has a predetermined measurement time, and has a predetermined measurement time and is repeated at a predetermined time interval. The state amount is measured according to the sampling cycle, and when the accumulated data amount reaches a predetermined transmission capacity, the accumulated measurement result is transmitted to the controller.
A fluid leakage detection system, wherein the operating condition changed by the condition setting unit includes at least one of the measurement time, the sampling cycle, and the transmission capacity of the measurement cycle. 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 that acquires the measurement results of the measurement unit and
Equipped with an operation unit operated by an operator,
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, and
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 controller
A signal acquisition unit that acquires change signals input from the outside,
It has a condition setting unit that outputs a command signal for instructing the operating condition to the measuring unit and changes the operating condition.
The command signal is
The first command signal that operates the measuring unit under the first operating condition,
A second command signal for operating the measuring unit under a second operating condition, which has a higher operating frequency than the first operating condition, is included.
The condition setting unit outputs the first command signal or the second command signal in response to the change signal acquired by the signal acquisition unit.
The measuring unit measures the state quantity by a method common to the first operating condition and the second operating condition.
The signal acquisition unit is a fluid leakage detection system characterized in that the change signal is acquired in response to an operation of the operation unit by an operator. The claim is characterized in that the measuring unit accumulates measurement results obtained by measuring the state quantity, and transmits the accumulated measurement results to the controller when the accumulated data amount reaches a predetermined data amount. The fluid leak detection system according to any one of 1 to 4 . Under the first operating condition, the measuring unit intermittently measures the state amount of the working fluid in the detection space.
The fluid leakage detection system according to any one of claims 1 to 5, wherein under the second operating condition, the measuring unit continuously measures the state quantity of the working fluid in the detection space. .. Under the first operating condition, the measuring unit intermittently transmits the measurement result to the controller.
The fluid leakage detection system according to any one of claims 1 to 6, wherein under the second operating condition, the measuring unit continuously transmits the measurement result to the controller.

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