JP4164675B2 - Servo valve characteristic measuring device - Google Patents

Description

  The present invention relates to a servo valve characteristic measuring apparatus that measures various characteristics of a servo valve.

  The hydraulic device sends hydraulic oil pressurized by a hydraulic pump to a hydraulic cylinder and a hydraulic motor through a servo valve, and drives various devices by extending and contracting the hydraulic cylinder and rotating the hydraulic motor. The servo valve needs to be overhauled regularly to maintain its function, and various characteristics of the servo valve such as pressure gain characteristics are measured in order to specify the overhaul time. In order to measure the characteristics of the servo valve, it is necessary to prepare various measuring devices according to the characteristics to be measured and to set conditions for the hydraulic circuit by a specialized engineer.

  By the way, the following Patent Document 1 proposes a “hydraulic system parameter identification method” aimed at measuring and identifying static characteristics and system parameters simply and accurately for various hydraulic equipment elements. FIG. 8 is a block diagram of an apparatus for carrying out this “hydraulic system parameter identification method”. A block diagram configured on the BDSP 84 and an operation in accordance with a certain control law (PID control, etc.) are performed in the internal CPU. The control input based on this is converted into a current signal i to drive the hydraulic servo valve 81, whereby the piston of the hydraulic cylinder 82 moves. The moving amount y of the piston is detected by a sensor 85 such as a laser displacement meter and fed back to the CPU of the BDSP 84. The spool displacement x can be measured by a gap sensor or the like. This system identifies the viscous damping rate of the valve spool, dead time, the friction characteristics of the hydraulic cylinder, the servo valve gain, and the like.

JP 2001-117627 A

  In the conventional characteristic measurement, it is necessary to prepare different measuring devices depending on the type of characteristic to be measured, and the condition setting of the hydraulic circuit must be done by an engineer with specialized knowledge, which is troublesome. . For these reasons, there are many cases where overhaul is performed uniformly after a certain period of use, rather than overhauling based on specific evaluation of performance degradation of the servo valve. For this reason, there is a problem in that the overhaul time is not always optimal because the progress of performance deterioration of the servo valve varies depending on the usage state of the servo valve.

  Patent Document 1 is intended to identify static characteristics and system parameters for a certain hydraulic system, and cannot measure pressure gain characteristics, neutral point bias / threshold characteristics, etc. of a servo valve. . Therefore, a specific deterioration evaluation of the servo valve based on these measurement results cannot be performed, and the above problem has not been solved.

  The present invention has been developed to solve the above-described problems. That is, the object of the present invention is to measure the characteristics with a single device regardless of the servo valve characteristics to be measured, without requiring a special engineer, and to optimize the overhaul timing of the servo valve. An object of the present invention is to provide a servo valve characteristic measuring apparatus capable of performing the above.

In order to solve the above-described problems of the present invention, a servo valve characteristic measuring apparatus according to the present invention includes a characteristic measuring hydraulic apparatus to which a servo valve to be measured is attached, and data necessary for measuring a predetermined servo valve characteristic. Servo valve control means for driving the servo valve so as to obtain data, data detection means for detecting data necessary for measurement of the servo valve characteristics, and servo valve characteristic information based on data from the data detection means. Characteristic information creating means for creating, wherein the characteristic information creating means creates a data sampling device for sampling data from the data detecting means, and creates servo valve characteristic information based on the sampling data from the data sampling device A plurality of measurement items obtained by classifying a plurality of types of servo valve characteristics by type. Output a measurement start command signal corresponding to one measurement item selected by the user, and have hydraulic circuit setting information of the characteristic measurement hydraulic device associated with each of the plurality of measurement items, When the measurement item is selected by the user, the hydraulic circuit setting information corresponding to the measurement item is displayed. The hydraulic circuit setting information includes guidance information on the open / close states of a plurality of manual stop valves and the set pressures of the pressure reducing valves. The servo valve control means drives the servo valve based on a measurement start command signal from the arithmetic processing unit .

According to the configuration of the present invention, the servo valve is driven so that the data necessary for measuring the characteristics of the servo valve can be obtained by the servo valve control means, and the data necessary for characteristic measurement is detected by the data detection means. Since the servo valve characteristic information is created by the characteristic information creating means, a specialized engineer is not required for measuring the characteristics of the servo valve. As a result, the servo valve characteristics can be measured easily and reliably, and the servo valve user can perform the overhaul timing of the servo valve at a constant period after performing a specific deterioration evaluation. become.
Further, since the characteristic information creating means is configured to be separated into the data sampling device and the arithmetic processing device, the degree of freedom of configuration can be increased by using, for example, a personal computer as the processing device.
In addition, when a measurement item for servo valve characteristics is prepared in advance and a desired measurement item is selected by the user, the arithmetic processing unit outputs a measurement start command signal corresponding to the measurement item to the servo valve control means. Therefore, a plurality of types of servo valve characteristics can be measured with a single measuring device. This eliminates the need to prepare different measuring devices depending on the type of servo valve characteristics to be measured.
In addition, since the setting information of the hydraulic circuit is displayed according to the measurement item selected by the user, the hydraulic circuit can be easily set even by a non-specialized engineer by following the display.

  In the servo valve characteristic measuring apparatus according to the present invention, preferably, the servo valve control means drives a servo valve based on a function generator for outputting a servo valve displacement target command signal and a signal from the function generator. The data sampling device and the function generator are housed in the same casing to constitute a data sampling device / function generator.

  According to such a configuration, since the data sampling device and the function generator are stored in the same housing and this is used as the data sampling device and function generator, the configuration of the characteristic measuring device itself is simplified, and also by the user Work such as connection between devices becomes unnecessary.

In the servo valve characteristic measuring apparatus according to the present invention, preferably, the arithmetic processing unit is a personal computer .

  By using a personal computer as the arithmetic processing unit, the degree of freedom in design is increased, and it is possible to respond quickly to future system upgrades. In addition, since management of characteristic information (characteristic data) can be stored in a storage medium, past results can be easily searched, compared, and edited.

  As described above, according to the servo valve characteristic measuring apparatus of the present invention, characteristic measurement can be performed with one apparatus regardless of the type of servo valve characteristic to be measured, and a specialized engineer is not required for measurement. There is an effect that the overhaul time of the servo valve can be optimized.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings 1 to 7.

  FIG. 1 is a diagram showing a configuration of a servo valve characteristic measuring apparatus according to the present invention. As shown in this figure, the servo valve characteristic measuring device 10 is roughly composed of a characteristic measuring hydraulic device 11 and a characteristic measuring control device 12.

  The characteristic measuring hydraulic device 11 incorporates a servo valve 1 to be measured, and the servo valve 1 constitutes a hydraulic circuit together with a pressure reducing valve and a manual open / close valve (not shown). The servo valve 1 includes a pilot valve 1a and a slave valve 1b. Each of the pilot valve 1a and the slave valve 1b has a spool, and the spool of the slave valve 1b according to the displacement of the spool of the pilot valve 1a. Is displaced, the flow of hydraulic oil is changed to drive a hydraulic cylinder serving as a drive unit.

  The characteristic measuring hydraulic device 11 is provided with pressure sensors 13, 14 for detecting the pressure on the secondary side of the hydraulic circuit, a flow sensor 15, and a spool sensor 16 for detecting the spool displacement of the slave valve 1b. Each of these sensors plays a role of detecting data necessary for measuring the servo valve characteristics, and functions as a data detecting means in the present invention.

  The characteristic measurement control device 12 includes a personal computer 4, a printer 5, a data sampling device / function generator 6, and a servo amplifier 9.

  The personal computer 4 has a main body 4a storing a CPU, a memory, a hard disk, etc., a monitor 4b for displaying various information such as servo valve characteristic information, and input means 4c such as a mouse and a keyboard. Application software (servo test software) is installed to execute the servo valve characteristic measurement. This software measures various servo valve characteristics such as step response, frequency response, pressure gain, internal leak, etc. of the servo valve 1 in cooperation with the data sampling device / function generator 6 and reports measurement results, measurement data Is executed. When the characteristic measurement is performed, the personal computer 4 outputs a measurement start command signal to the data sampling device / function generator 6 for the item to be measured from the various servo valve characteristics, and also functions as the data sampling device. It has a function as an arithmetic processing unit that receives sampling data from the function generator 6, creates servo valve characteristic information based on the sampling data, and displays it.

  The data sampling device / function generator 6 is configured by storing the data sampling device 7 and the function generator 8 in the same casing. The data sampling device / function generator 6 is connected to the personal computer 4 via a LAN. The function generator 8 generates a servo valve displacement target command signal based on the measurement start command signal from the personal computer 4 and outputs the command signal to the servo amplifier 9 via a D / A converter (not shown). have. The data sampling device 7 measures servo valve characteristics such as pressure results, flow results, spool displacement results, servo current results from the servo amplifier 9 and the like, which are respectively input from the pressure sensors 13 and 14, the flow sensor 15 and the spool sensor 16. It has a function of sampling necessary data and outputting the sampling data to the personal computer 4. The personal computer 4 and the data sampling device 7 function as characteristic information creating means in the present invention.

  The servo amplifier 9 has a function of driving the pilot valve 1a based on a command signal from the function generator 8 and controlling the position (opening) of the spool of the slave valve 1b. The servo current record and the spool displacement record detected by the spool sensor 16 are output to the data sampling device 7 via an A / D converter (not shown).

  Next, the operation and operation of the servo valve characteristic measuring apparatus 10 having the above configuration will be described. FIG. 2 is a diagram for explaining a “valve information input screen” displayed on the monitor 4 b of the personal computer 4. As shown in this figure, when the servo test software described above is activated in the personal computer 4, a “valve information setting dialog” is displayed. Here, the user inputs the type of the servo valve 1 in the type column 101, and inputs the serial numbers of the pilot valve 1a and the slave valve 1b in the input columns 102 and 103, respectively. Note that only the serial number of the pilot valve 1a is input when measuring the pilot valve alone, and both serial numbers are input when measuring the combined pilot valve and slave valve. Then, after confirming the input content, the “OK” button 104 is clicked. A series of test results performed thereafter are managed and stored in the unit set and registered here, and a test report is also output in this unit.

  After the input of the valve information is completed, a “measurement item selection screen” as shown in FIG. 3 is displayed. As shown in this figure, the “measurement item selection screen” displays servo valve characteristics classified as types and displayed as measurement items. In the servo valve characteristic measuring apparatus 10 of the present embodiment, a pressure gain characteristic, a threshold / neutral bias characteristic, and an internal leak characteristic are set as the characteristics of the pilot valve alone, and the pressure gain characteristic is set as the pilot valve / slave valve combination characteristic. Threshold / neutral bias characteristics, internal leak characteristics, step response characteristics, frequency response characteristics, and hysteresis characteristics are set. The user can select the item keys 201 to 209 to be measured from these measurement items by clicking on them.

When a measurement item is selected, a “guidance screen” as shown in FIG. 4 is displayed. In this “guidance screen”, setting information (setting conditions) of the hydraulic circuit of the characteristic measurement hydraulic device 11 is displayed according to the item selected on the “measurement item selection screen” described above. The name of the valve, the state of opening and closing, etc. are displayed with pictures and characters. In this example, the text guidance is as follows.
(1) A pilot valve and a slave valve are properly attached to the hydraulic device for characteristic measurement.
(2) Connect the connector to the pilot valve and slave valve.
(3) Set the manual stop valves (12-1 to 2, 13-1 to 2, 14-1 to 2, 15-1 to 4) as illustrated. Valves that are filled and displayed are closed and valves that are outlined are opened.
(4) No. 6 manual direction switching valve is operated to select the direction of the oil cooler.
(5) Start the hydraulic pump and confirm that there is no oil leak. Stop hydraulic pump when oil leak is found.
(6) Adjust the pressure reducing valves (17-1, 17-2) to be suitable for the hydraulic system. The pressure reducing valve 17-1 is set to 20.6 MPa. The pressure reducing valve 17-2 is set to 20.6 MPa.
(7) Turn the gain VR dial on the front panel of the servo amplifier to obtain an appropriate servo gain.
(8) Turn on the servo amplifier.
(9) Set the state of the valve as shown in the picture, and click the “Confirm” button 301 after confirming that everything is complete.
Thereby, the user can set the hydraulic circuit easily and reliably.

  When, for example, “pressure gain characteristics” is selected on the “measurement item selection screen” described above, when the “confirmation” button 301 is clicked on the “guidance display screen”, a “pressure gain screen” as shown in FIG. 5 is displayed. When “Threshold / Neutral Point Bias” or “Internal Leakage” is selected in the “Measurement Item Selection Screen”, the “Threshold / Neutral Point Bias Screen” or “Internal Leakage Screen” is displayed respectively. . When other measurement items are selected, the corresponding screens are similarly displayed (hereinafter, these screens are collectively referred to as “measurement screens”). As shown in this figure, the “measurement screen” includes a graph area 401, a measurement result area 402 for displaying the pressure gain reference value and measurement value, an area 403 for displaying the servo valve type, a file name, a registration date, and the like. An area 404 for displaying the date and an area 405 for displaying the date and the like are provided. The “reference value” refers to a value (initial value) when the servo valve is not used. If a “measurement start” button 406 is clicked here, measurement is started. When the measurement is completed, a waveform is displayed in the graph area 401, and a pressure gain measurement value is displayed in the measurement result area 402. As a result, the user can evaluate the deterioration of the servo valve by comparing the measured value with the reference value, so that the servo valve user performs the servo valve overhaul time in a uniform period. It becomes possible to carry out after specific deterioration evaluation.

  Next, the contents of the characteristic measurement process by the servo valve characteristic measurement apparatus 10 will be described with reference to the flowcharts shown in FIGS. First, in FIG. 6, the user selects one measurement item from a plurality of measurement items on the “measurement item selection screen” in the personal computer (PC) 4 (S1). Then, a “guidance screen” is displayed, and when the user who has finished setting the hydraulic circuit clicks the “confirm” button (S2), a measurement screen such as a “pressure gain screen” is displayed. Here, when the “measurement start” button is clicked (S3), a measurement start command signal (measurement command) corresponding to the measurement item is sent to the sampling device / function generator (hereinafter referred to as “SU” in this figure) 6. Is output (S4), and the process proceeds to processing in the data sampling device / function generator 6 (S5).

  Moving to FIG. 7, when the data sampling device / function generator 6 receives the measurement command signal from the personal computer 4 at the PC communication processing unit (S 51), the measurement item is extracted (S 52), and the measurement condition data Reading is performed (S53). In reading the measurement data, the sampling time, the number of sampling data, the sampling data (sampling target signal), and the servo Ref function are read. Next, the measurement processing start FLAG is set (S54), and the clock processing (S55) and servo Ref function output processing (S56) are entered. When a servo ref function signal is generated in the servo ref function output process and output to the servo amplifier 9 via the D / A converter (S56), the servo valve 9 is driven by the servo amplifier 9, and the servo valve opening degree is increased. The results, servo current results, flow results, pressure results A, and pressure results B are detected by each sensor as data. The detected data is converted into a digital signal by the A / D converter and subjected to scaling processing (S57). Moreover, the differential pressure | voltage calculation of the pressure results A and the pressure results B is performed here (S57).

  On the other hand, when the clock is generated in the clock process (S55), the sampling (sampling interrupt process) of the data that has been subjected to the scaling process and the differential pressure calculation is performed (S58). In the sampling interrupt process, the sampling counter is incremented and data is written (S58). When the sampling counter matches the number of sampling data, the measurement start FLAG is reset (S59, S60). The sampling data created in this way is transmitted to the personal computer 4 (S61), thereby ending the processing in the data sampling device / function generator 6 (S62).

  Now, referring back to FIG. 6, when the personal computer 4 receives sampling data from the sampling device / function generator 6 (S6), the sampling data is rearranged according to the measurement item, size discrimination, Fourier expansion, etc. Processing, editing, and calculation are performed (S7), and measurement results (servo valve characteristic information) such as graphs and measurement values are displayed on a measurement screen such as a “pressure gain screen” according to the characteristics (S8). The servo valve characteristic information is stored in a hard disk of the personal computer 4 or a recording medium such as FD, MO, etc. (S9), and the measurement of the servo valve characteristic is completed (S10).

  According to the configuration of the present invention as described above, the servo valve is driven so that the data necessary for measuring the characteristics of the servo valve can be obtained by the servo valve control means, and the data required for the characteristic measurement by the data detecting means. Since the servo valve characteristic information is created by the characteristic information creating means, a special engineer is not required for measuring the characteristic of the servo valve. This makes it possible to easily and reliably measure the characteristics of the servo valve and to perform a specific deterioration assessment of what the servo valve user has performed overhaul of the servo valve for a fixed period of time. It becomes like this.

  Further, since the characteristic information creating means is configured to be separated into the data sampling device and the arithmetic processing device, the degree of freedom of configuration can be increased by using, for example, a personal computer as the processing device.

  In addition, since the data sampling device and the function generator are stored in the same housing, and this is used as the data sampling device and function generator, the configuration of the characteristic measuring device itself is simplified, and each device is connected by the user. Is no longer necessary.

  In addition, when a measurement item for servo valve characteristics is prepared in advance and a desired measurement item is selected by the user, the arithmetic processing unit outputs a measurement start command signal signal corresponding to the measurement item to the servo valve control means. Therefore, a plurality of types of servo valve characteristics can be measured with a single measuring device. This eliminates the need to prepare different measuring devices depending on the type of servo valve characteristics to be measured.

  Further, since the hydraulic circuit setting information is displayed according to the measurement item selected by the user, by following the display, the hydraulic circuit can be easily set even by a specialized engineer.

  Further, by using a personal computer as the arithmetic processing unit, the degree of freedom in design is increased, and it is possible to quickly cope with future system upgrades. In addition, since management of characteristic information (characteristic data) can be stored in a recording medium, past results can be easily searched, compared, and edited.

  Therefore, according to the servo valve characteristic measuring apparatus of the present invention, regardless of the type of servo valve characteristic to be measured, characteristic measurement can be performed with one apparatus, and a specialized engineer is not required for measurement, and Excellent effects such as optimization of the servo valve overhaul timing can be obtained.

  In the above-described embodiment, the servo valve 1 is intended for a configuration including a pilot valve and a slave valve, but is not limited to this, and can be similarly applied to other types of servo valves. . Further, the servo valve characteristics are not limited to the above-described characteristics, and various other servo valve characteristics may be measured.

  In addition, the present invention is not limited to the above-described embodiments, and various changes can be made without departing from the scope of the present invention.

It is a block diagram of embodiment of the servo valve characteristic measuring apparatus of this invention. It is a figure explaining a "valve information input screen". It is a figure explaining a "measurement item selection screen". It is a figure explaining a "guidance screen." It is a figure explaining a "pressure gain screen". It is a flowchart of the characteristic measurement process by this invention. It is a flowchart of the characteristic measurement process by this invention. It is a block diagram of the apparatus which implements the method of patent document 1. FIG.

Explanation of symbols

1 Servo valve 4 Personal computer (processing unit)
6 Data Sampling Device / Function Generator 7 Data Sampling Device 8 Function Generator 9 Servo Amplifier 10 Servo Valve Characteristic Measuring Device 11 Characteristic Measuring Hydraulic Device 12 Characteristic Measuring Control Device 13, 14 Pressure Sensor 15 Flow Sensor 16 Spool Sensor

Claims (3)

A hydraulic device for measuring characteristics to which a servo valve to be measured is attached;
Servo valve control means for driving the servo valve so as to obtain data necessary for measuring a predetermined servo valve characteristic;
Data detection means for detecting data necessary for measuring the servo valve characteristics;
Characteristic information creating means for creating servo valve characteristic information based on data from the data detecting means,
The characteristic information creation means includes a data sampling device that samples data from the data detection means, and an arithmetic processing device that creates servo valve characteristic information based on sampling data from the data sampling device,
The arithmetic processing unit outputs a measurement start command signal corresponding to one measurement item selected by a user from a plurality of measurement items classified into a plurality of types of servo valve characteristics, and the plurality of measurement items. Each having the hydraulic circuit setting information of the characteristic measurement hydraulic device, and when the measurement item is selected by the user, the hydraulic circuit setting information corresponding to the measurement item is displayed,
The hydraulic circuit setting information includes guidance information on the open / close states of a plurality of manual stop valves and the set pressures of the pressure reducing valves,
The servo valve characteristic measuring apparatus, wherein the servo valve control means drives the servo valve based on a measurement start command signal from the arithmetic processing unit. The servo valve control means has a function generator that outputs a servo valve displacement target command signal and a servo amplifier that drives the servo valve based on a signal from the function generator,
2. The servo valve characteristic measuring device according to claim 1 , wherein the data sampling device and the function generator are stored in the same casing to constitute a data sampling device / function generator. The processor is a personal computer, a servo valve characteristic measuring apparatus according to claim 1 or 2, characterized in.

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