JP4188670B2 - Measuring method of hydraulic supply system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a measurement method of a hydraulic pressure supply system including an accumulator that stores pressurized hydraulic fluid supplied from a hydraulic pressure source.
[0002]
[Prior art]
Conventionally, this type of accumulator is divided into a gas chamber filled with a gas at a predetermined pressure and an oil reservoir chamber that stores hydraulic oil, and the gas chamber expands and contracts as the pressure in the oil reservoir chamber fluctuates to absorb hydraulic pulsation. Or increase the response of oil pressure changes.
[0003]
By the way, in the accumulator, the gas sealed in the gas chamber may leak and the gas charging pressure may be insufficient. Therefore, it is necessary to constantly monitor the gas charging pressure of the accumulator.
[0004]
For this reason, as shown in FIG. 3, the hydraulic pressure supply system disclosed in Japanese Patent Application Laid-Open No. 8-14501 is a detection signal of the hydraulic sensor 6 in the process in which the controller (measuring means) 5 is filled with the working oil. The pressure rise characteristic of the accumulator 1 is obtained based on the above, and the pressure P0 at the change point of the oil pressure rise rate is measured as the gas filling pressure of the accumulator 1.
[0005]
In the process of filling the accumulator 1 with hydraulic oil, the oil pressure in the oil passage 12 rapidly increases until the gas chamber 3 starts to contract as shown in FIG. 4, and when the gas chamber 3 starts to contract via the bladder 2. It has a characteristic of rising slowly. Therefore, the oil pressure P1 at this change point can be detected as the gas charging pressure.
[0006]
[Problems to be solved by the invention]
However, when a plurality of accumulators 1 are connected to the hydraulic power source 9, if each accumulator 1 is filled with hydraulic oil at the same time, the hydraulic pressure increase characteristics of the accumulators 1 detected by the hydraulic sensor 6 overlap. There was a problem that the gas filling pressure of each accumulator 1 could not be measured individually. That is, or has been set different gas filling pressure in each accumulator 1, or if the variation in the gas filling pressure of the accumulator 1 occurs, the pressure of the low accumulator 1 of the gas charged pressure is high gas charged pressure accumulator 1 It is difficult to detect the inflection point of the pressure rise characteristic of each accumulator 1. In FIG. 5, points A, B, and C represent pressure inflection points of the respective accumulators 1 with different gas filling pressures. As can be seen from this figure, accumulators with high gas filling pressures are shown. 1 indicates that the waveform is distorted at the pressure inflection point, making it difficult to detect.
[0007]
Also, the branch passage stop valve each time introducing hydraulic oil to the accumulator 1 is provided, if filled with hydraulic fluid in order for each accumulator 1, that the inflection point of the pressure rise characteristics of the accumulators 1 individually detected it can. However, in this case, open the stop valve when filling the hydraulic oil in the accumulator 1, close the stop valve when filling the hydraulic oil to other accumulator 1, again after filling the hydraulic oil to all of the accumulator 1 stop Since it is necessary to open the valve, there is a problem that it takes time to open and close the stop valve.
[0008]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a measurement method of a hydraulic pressure supply system that individually measures gas filling pressures of a plurality of accumulators.
[0009]
[Means for Solving the Problems]
The first invention is applied to a hydraulic pressure supply system including a plurality of accumulators that store pressurized hydraulic fluid supplied from a hydraulic pressure source.
[0010]
And a plurality of check valves for guiding the hydraulic oil stored in each accumulator, a plurality of stop valves for returning the hydraulic oil in each accumulator to the tank, a plurality of hydraulic sensors for detecting the hydraulic pressure of each accumulator, and each stop valve. It opens with a display means for displaying a detection signal that the hydraulic change seeking oil pressure characteristics of the accumulators based on the respective hydraulic pressure sensor in the process of hydraulic oil is extracted from the accumulators, in order to each valve with a time difference The measuring method of the hydraulic pressure supply system is characterized in that the change point of the hydraulic pressure drop rate in each accumulator displayed on the display means is detected as the gas filling pressure of each accumulator .
[0012]
Operation and effect of the invention
According to the first invention, the gas of the different accumulators connected to the common hydraulic power source is configured to measure the gas filling pressure of each accumulator according to the detection signal of each hydraulic sensor when the hydraulic oil is extracted from each accumulator. The sealing pressure can be measured individually.
[0013]
Moreover, it can implement easily by changing the processing content of a controller etc., without using the pneumatic sensor etc. which detect the gas pressure of an accumulator.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0016]
FIG. 1 shows a hydraulic pressure supply system provided in a magnetically levitated vehicle. The magnetically levitated vehicle is provided with a hydraulic actuator that brakes the wheel as well as a hydraulic actuator that raises and lowers the wheel, although not shown, in order to run the wheel before and after the levitating run.
[0017]
The hydraulic fluid from the hydraulic pressure source 9 is stored in the accumulator 1 through the check valve 13, and the accumulator 1 functions to absorb hydraulic pressure pulsations and increase the response to changes in hydraulic pressure.
[0018]
The accumulator 1 is a pressure accumulator that stores hydraulic oil from a hydraulic source 9 in a pressurized state. The accumulator 1 includes a gas chamber 3 in which a gas of a predetermined pressure is sealed in a pressure accumulator via a bladder 2 made of an elastic member. Is separated from the oil reservoir chamber 4, and the gas chamber 3 expands and contracts in accordance with the pressure fluctuation of the oil reservoir chamber.
[0019]
In addition, the accumulator 1 is good also as a structure provided with the piston which slides with respect to a pressure accumulation container, and a gas chamber and an oil reservoir chamber are partitioned off via this piston.
[0020]
An oil passage 12 that connects the accumulator 1 and an actuator (not shown) is provided, and the oil passage 12 is connected to the tank 11 via a stop valve 10. When the vehicle leaves the vehicle, the stop valve 10 is closed and the hydraulic pressure source 9 is operated to fill the oil passage 12 and the accumulator 1 with hydraulic oil. On the other hand, when the vehicle is stored, the stop valve 10 is opened, and the hydraulic oil in the oil passage 12 and the accumulator 1 is returned to the tank 11.
[0021]
A hydraulic pressure sensor 6 that detects the hydraulic pressure of the accumulator 1 is connected to the oil passage 12. The detection signal of the hydraulic sensor 6 is input to the controller 5, and the controller 5 inputs the detection signal of the hydraulic sensor 6, and operates the hydraulic source 9 so that the operating hydraulic pressure stored in the accumulator 1 is maintained at a predetermined value or more. Control.
[0022]
A plurality of accumulators 1 are connected to a common hydraulic pressure source 9, and an oil passage 12, a manual stop valve 10, a hydraulic sensor 6, and the like are provided for each accumulator 1.
[0023]
Since each accumulator 1 leaks the gas sealed in the gas chamber 3 and the gas sealing pressure, which is the pressure in the gas chamber 3 when the accumulator 1 is not filled with hydraulic oil, may be insufficient. It is necessary to constantly monitor the gas filling pressure.
[0024]
The gist of the present invention is that, in order to individually measure the gas filling pressure of each accumulator 1, the controller 5 uses the detection signal of the hydraulic sensor 6 in the process of extracting the hydraulic oil from the accumulator 1 at the time of warehousing. The hydraulic pressure drop characteristic of the accumulator 1 is displayed on the screen, and the pressure at the change point of the hydraulic pressure drop rate can be measured as the gas filling pressure of the accumulator 1.
[0025]
The controller 5 displays on the monitor 7 how the detection signal of the hydraulic sensor 6 changes with respect to the elapsed time. In the process of extracting hydraulic oil from the accumulator 1, the oil pressure in the oil passage 12 gradually decreases while the gas chamber 3 expands through the bladder 2 as shown in FIG. There is a deteriorating property. Therefore, the operator opens the stop valve 10 in order with a time difference, looks at the change point of the oil pressure decrease rate in each accumulator 1 from the monitor 7, and uses the oil pressures P <b> 2 and P <b> 3 at these change points as the gas filling pressure of each accumulator 1. It can be detected.
[0026]
In this system, not only the gas filling pressure is confirmed by looking at the accumulator hydraulic pressure drop characteristic displayed on the screen of the monitor 7, but also the controller 5 calculates the change rate of the detection signal of the hydraulic sensor 6, and this change rate is predetermined. The detected pressure P1 when the value is exceeded can be obtained, and the gas filling pressure can be automatically displayed as a numerical value.
[0027]
The controller 5 can also activate the alarm device 8 when the determined gas filling pressure falls below a predetermined value.
[0028]
As described above, since the gas filling pressure of the accumulator 1 is measured in accordance with the detection signal of the hydraulic sensor 6 when the hydraulic oil is extracted from the accumulator 1, the gas filling of each accumulator 1 connected to the common hydraulic pressure source 9 is performed. The pressure can be measured individually.
[0029]
By the way, when the flow rate at which the hydraulic oil is extracted from the accumulator 1 changes according to the opening degree of the stop valve 10, the degree of temperature drop due to the expansion of the gas chamber 3 differs, so the hydraulic pressure drop characteristic of the accumulator 1 changes. For this reason, the measurement value of the gas filling pressure varies depending on the opening of the stop valve 10.
[0030]
Therefore, as another embodiment, the controller 5 obtains the flow rate of the hydraulic oil flowing out from the accumulator 1 according to the change rate of the detection signal of the hydraulic sensor 6 in the process of extracting the hydraulic oil from the accumulator 1 at the time of warehousing. The gas filling pressure of the accumulator 1 may be corrected according to the flow rate of the hydraulic oil.
[0031]
By correcting the gas filling pressure of the accumulator 1 in accordance with the flow rate of the hydraulic oil, it is possible to suppress variations in the measured value of the gas filling pressure due to the degree of temperature drop caused by the expansion of the gas chamber 3.
[0032]
The present invention is not limited to the above-described embodiment, but can be applied to various hydraulic circuits provided with an accumulator, and it is obvious that various modifications can be made within the scope of the technical idea.
[Brief description of the drawings]
FIG. 1 is a system diagram of a hydraulic pressure supply system showing an embodiment of the present invention.
FIG. 2 is a graph showing a decrease in hydraulic pressure when hydraulic oil is extracted from the accumulator.
FIG. 3 is a system diagram of a hydraulic pressure supply system showing a conventional example.
FIG. 4 is a characteristic diagram of working oil pressure when the accumulator is filled with working oil.
FIG. 5 is a characteristic diagram of hydraulic pressure when hydraulic oil is charged into a plurality of accumulators.
[Explanation of symbols]
1 Accumulator 3 Bladder 4 Oil reservoir 5 Controller (Measuring means)
6 Hydraulic sensor 7 Monitor (display means)
9 Hydraulic source 10 Stop valve 12 Oil passage

Claims (1)

In a hydraulic supply system including a plurality of accumulators that store pressurized hydraulic fluid supplied from a hydraulic source , a plurality of check valves that guide hydraulic fluid stored in each accumulator, and a plurality of stops that return the hydraulic fluid in each accumulator to the tank A valve, a plurality of hydraulic sensors for detecting the hydraulic pressure of each accumulator, and determining the hydraulic pressure drop characteristics of each accumulator based on the detection signal of each hydraulic sensor in the process of opening each stop valve and extracting hydraulic oil from each accumulator Using a display means for displaying a change in hydraulic pressure , opening each stop valve in order with a time difference, and detecting the change point of the hydraulic pressure drop rate in each accumulator displayed on the display means as a gas filling pressure of each accumulator Measuring method of hydraulic supply system.

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