KR20230085651A - Cushion performance analysis device of hydraulic cylinder and cushion performance analysis method using thereof - Google Patents

Abstract

An apparatus and method for analyzing cushion performance of a hydraulic cylinder according to the present invention include a hollow cylinder; a piston installed inside the cylinder to be movable in the longitudinal direction of the cylinder; a rod installed to move integrally with the piston; a head cover installed at one end of the cylinder and provided with a passage through which fluid flows; a rod cover installed at the other end of the cylinder and provided with a passage through which fluid flows; and a cushion part provided on the head cover and the rod cover to prevent sudden collision of the piston, wherein a displacement-velocity detection sensor for measuring displacement and speed of the piston in real time is installed in the cylinder. A first pressure sensor for measuring the pressure of the fluid between the piston and the head cover is installed on the head cover, and a second pressure sensor for measuring the pressure of the fluid between the piston and the rod cover is installed on the rod cover. a data collection device for receiving and storing measured values of the displacement-velocity detection sensor, the first pressure sensor, and the second pressure sensor; and a data processing device that calculates a deceleration rate generated in a cushioning process in real time from measured values stored in the data collection device.

Description

Cushion performance analysis device of hydraulic cylinder and cushion performance analysis method using it}

The present invention relates to an apparatus for analyzing cushion performance of a hydraulic cylinder and a method for analyzing cushion performance.

In general, a hydraulic cylinder is a mechanical element that inputs fluid into the cylinder using hydraulic pressure, pushes a piston with the force of the fluid, receives the movement of the piston to a rod, and generates mechanical reciprocating motion.

Hydraulic cylinders are installed and used in various equipment, for example, are widely used in aerial work vehicles, forklifts, excavators, and the like. In this hydraulic cylinder, work is performed while the rod is repeatedly stretched and compressed.

During the process of extension and compression of the rod, the piston reciprocates inside the cylinder, and on both sides of the inside of the cylinder, there is a cushion part, which is a part where the transfer of the piston is decelerated and then stopped.

The cushion performance of the hydraulic cylinder is determined by looking at the shape of the graph or the deceleration rate according to the pressure and time acting on the hydraulic cylinder during operation of the hydraulic cylinder.

By the way, the conventional cushion performance testing apparatus or method of the hydraulic cylinder is configured to measure the displacement of the rod with a sensor, measure the pressure of the fluid with a sensor, and calculate the deceleration rate from the values of the displacement and pressure.

However, in the process of operating the cushion function of the hydraulic cylinder, there is a lot of noise in the displacement (stroke) value of the rod measured by the sensor, so the structure and method for calculating the deceleration rate based on the displacement value are less accurate, real-time measurement There is this difficult problem.

001 KR10-1468557 B1 (2014.11.27)

An object of the present invention has been made to solve the problems described above, and by improving a cushion performance measuring device and method of a hydraulic cylinder, cushion performance measurement of a hydraulic cylinder that can precisely measure the cushion performance of a hydraulic cylinder in real time It is to provide an apparatus and method.

In order to achieve the above object, an apparatus for analyzing cushion performance of a hydraulic cylinder according to the present invention includes a hollow cylinder;

a piston installed inside the cylinder to be movable in the longitudinal direction of the cylinder;

a rod installed to move integrally with the piston;

a head cover installed at one end of the cylinder and provided with a passage through which fluid flows;

a rod cover installed at the other end of the cylinder and provided with a passage through which fluid flows; and

In the hydraulic cylinder device provided with a cushion portion for preventing the piston from rapidly colliding with the head cover and the rod cover,

A displacement-velocity detection sensor for measuring the displacement and speed of the piston in real time is installed in the cylinder,

A first pressure sensor for measuring the pressure of the fluid between the piston and the head cover is installed on the head cover,

A second pressure sensor for measuring the pressure of the fluid between the piston and the rod cover is installed on the rod cover,

a data collection device receiving and storing measured values of the displacement-velocity detection sensor, the first pressure sensor, and the second pressure sensor; and

It is characterized in that it includes a data processing device that calculates the deceleration rate generated in the cushioning process in real time from the measured values stored in the data collection device.

Preferably, the data processing device is configured to extract, as a cushion end speed, a speed of the piston at a point in time when a change in an absolute value of the first pressure sensor or the second pressure sensor is greater than a predetermined value.

In the data processing, the device extracts a displacement value measured by a displacement-velocity detection sensor corresponding to a time having the cushion end speed value as a maximum stroke value,

It is preferable to extract the speed of the piston as the cushion start speed for a speed value of the piston at a time corresponding to a displacement value obtained by subtracting the cushion stroke value input in advance from the maximum stroke value.

In order to achieve the above object, as a cushion performance analysis method using a cushion performance analysis device of a hydraulic cylinder,

Moving the piston at a constant speed by entering and exiting the cylinder, and operating the hydraulic cylinder so that the piston is decelerated by a cushioning action,

a cushion end speed extraction step of extracting, as a cushion end speed, a speed of a piston at a point in time when a change in an absolute value of the first pressure sensor or the second pressure sensor is greater than a predetermined value due to the cushion action;

a maximum stroke value extraction step of extracting, as a maximum stroke value, a displacement value measured by a displacement-velocity detection sensor corresponding to a time having the cushion end velocity value, which is performed after the cushion end velocity extracting step;

a cushion start speed extraction step, which is performed after the maximum stroke value extraction step, and extracts, as a cushion start speed, a speed value of the piston at a time corresponding to a displacement value obtained by subtracting a cushion stroke value input in advance from the maximum stroke value; and

It is characterized in that it includes a deceleration rate calculation step of storing a value obtained by calculating a difference between the cushion start speed and the cushion end speed as a percentage of the cushion start speed as a deceleration rate.

An apparatus for measuring cushion performance of a hydraulic cylinder and a method for measuring cushion performance of a hydraulic cylinder according to the present invention extract cushion end speed and cushion start speed using the value of a displacement-velocity detection sensor that simultaneously measures the speed and displacement of a piston in real time. It provides the effect of quickly and accurately calculating the deceleration rate, which is a major factor in determining cushion performance.

In addition, since the cushion performance measurement device and cushion performance measurement method of a hydraulic cylinder according to the present invention can calculate a deceleration rate in real time, there is an effect of providing an environment in which an optimal cushion condition can be applied in a short time.

In addition, the cushion performance measuring device and cushion performance measuring method of the hydraulic cylinder according to the present invention obtain and store the pressure of the fluid, the speed and displacement of the piston in real time, thereby providing data for the utilization of big data in designing the hydraulic cylinder cushion structure. Provides actionable effects that can be built.

1 is a diagram showing the configuration of an apparatus for analyzing cushion performance of a hydraulic cylinder according to a preferred embodiment of the present invention.
FIG. 2 is a graph showing values measured by a sensor of the cushion performance analyzer shown in FIG. 1 .
FIG. 3 is a diagram microscopically showing a graph in a section in which a cushion function is performed in the graph shown in FIG. 2 .
4 is a process chart of a cushion performance analysis method according to the present invention.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing the configuration of an apparatus for analyzing cushion performance of a hydraulic cylinder according to a preferred embodiment of the present invention. FIG. 2 is a graph showing values measured by a sensor of the cushion performance analyzer shown in FIG. 1 . FIG. 3 is a diagram microscopically showing a graph in a section in which a cushion function is performed in the graph shown in FIG. 2 . 4 is a process chart of a cushion performance analysis method according to the present invention. 2 and 3, the horizontal axis represents time (seconds), and the vertical axis represents piston displacement (mm), piston speed (mm/s), and fluid pressure (bar). 2 and 3, the RC pressure is the pressure value of the fluid on the rod cover side, and the HC pressure is the pressure value of the fluid on the head cover side.

1 to 3, the apparatus 10 for analyzing cushion performance of a hydraulic cylinder according to a preferred embodiment of the present invention includes a hydraulic cylinder 20, a displacement-speed detection sensor 50, and a first pressure sensor ( 60), a second pressure sensor 70, a data collection device 80, and a data processing device 90.

The hydraulic cylinder 20 includes a cylinder 22, a piston (not shown), a rod 26, a head cover 28, and a rod cover 30.

The cylinder 22 is a hollow member. Inside the cylinder 22, a piston and a rod 26 to be described later are movably installed.

The piston is installed inside the cylinder to be movable in the longitudinal direction of the cylinder.

The rod 26 is installed to move integrally with the piston. The rod 26 may be coupled with a known structure such as screw coupling with the piston.

The head cover 28 is installed on one end of the cylinder 22 . The head cover 28 is provided with a flow path through which fluid enters and exits the cylinder 22 .

The rod cover 30 is installed on the other end of the cylinder 22 . The rod cover 30 is provided with a flow path through which fluid enters and exits the cylinder 22 .

The head cover 28 and the rod cover 30 are each provided with a cushion part (not shown) to prevent a sudden collision of the piston. As the structure of the cushion part, a known conventional structure may be employed.

The displacement-speed detection sensor 50 is a sensor that measures the displacement and speed of the piston in real time. The displacement-velocity detection sensor 50 may be installed in the cylinder 22 . In the displacement-velocity detection sensor 50, a wire 52 having one end connected to a wire jig 54 fixed to an end of a rod 26 moving integrally with the piston is installed inside the displacement-velocity sensor 50. It is a sensor that is physically connected to rotate the rotating plate of the tachometer and can measure the displacement and speed of the piston at the same time. The wire jig 54 moves integrally with the rod 26 . More specifically, the displacement (STROKE) and speed of the piston have the same value as (26) the displacement and speed of the rod (26). The displacement-velocity detection sensor 50 outputs the displacement as a current value and outputs the velocity as a voltage value and transmits it to the data collection device 80 . The displacement-velocity detection sensor 50 may be configured by employing a displacement-velocity detection sensor having a known structure.

The first pressure sensor 60 is installed on the head cover 28 . The first pressure sensor 60 measures the pressure of the fluid between the piston and the head cover 28 and transmits it to the data collection device 80 . The first pressure sensor 60 may be configured by employing a pressure sensor having a known structure. The first pressure sensor 60 outputs the fluid pressure measured by the strain gauge as a current value.

The second pressure sensor 70 is installed on the rod cover 30 . The second pressure sensor 70 measures the pressure of the fluid between the piston and the rod cover 30 and transmits it to the data collection device 80 . The second pressure sensor 70 may be configured by employing a pressure sensor having a known structure. The second pressure sensor 70 outputs the fluid pressure measured by the strain gauge as a current value.

The data collection device 80 is a device that receives and stores measurement values of the displacement-velocity detection sensor 50, the first pressure sensor 60, and the second pressure sensor 70. The data collection device 80 may be wired or wirelessly connected to the sensors.

The data processing device 90 is a device that calculates the deceleration rate generated in the cushioning process in real time from the measured values stored in the data collecting device 80 . A process performed in the data processing device 90 will be described later in detail.

The data collection device 80 or the data processing device 90 is configured to transmit voltage or It is preferable to include an algorithm that converts the value of the current into an actual pressure value.

Referring to FIG. 2 , while the rod 26 repeats expansion and contraction according to the hydraulic pressure acting on the piston, the displacement-velocity detection sensor 50 receives the displacement and speed values of the piston and the first pressure sensor. 60 and a graph showing changes in pressure values of the fluid received from the second pressure sensor 70 based on the same time axis, it is easy to understand the tendency of the values of the corresponding sensors to change. More specifically, there is a constant speed section in which the displacement changes with a constant slope according to the movement of the piston, and there is a deceleration section in which the displacement value changes very gently as the cushion function operates. In this process, the speed value of the piston appears as an irregular waveform change. In addition, it can be seen that the value measured by the first pressure sensor 60 or the second pressure sensor 70 in the constant speed section maintains an almost constant value, but changes rapidly in the form of a curve in the deceleration section. In the present invention, a data processing device 90 to which an algorithm capable of accurately measuring cushion performance from variously changing sensor values is applied.

In analyzing the cushion performance of the hydraulic cylinder 20, a key factor is the deceleration rate. The deceleration rate represents the difference between the speed in the constant speed section and the speed in the deceleration section as a percentage of the speed in the constant speed section.

Conventionally, the speed of the constant speed section was calculated by calculating the slope of the change value of the displacement changed for a specific time in the section where the piston moves at constant speed, that is, the normal extension or extension section, in an analog method. On the other hand, the speed in the deceleration section was obtained by dividing the difference in displacement of the piston generated during the operation of the cushion function by the time during which the corresponding displacement occurred. However, the deceleration period is very short, about 0.2 to 0.5 seconds in some cases. Accuracy is significantly reduced when calculating the deceleration section speed in an analog manner from the displacement of the piston in such a short section. The present invention includes a displacement-velocity detection sensor 50 capable of simultaneously measuring the speed and displacement of the piston in real time so as to precisely calculate the speed in the deceleration section.

Now, with reference to FIGS. 1 to 4, how to extract the constant speed section speed and the deceleration section speed for calculating the deceleration rate from the values measured by the sensors will be described in detail.

In the present invention, it is configured to extract the speed of the deceleration section first than the speed of the piston in the constant speed section. More specifically, referring to the graph shown in FIG. 3 , in the deceleration section, values of fluid pressure, speed and displacement of the piston are noticeably changed by the cushioning action. In particular, when the cushion action ends, the value of the first pressure sensor 60 or the second pressure sensor 70 rapidly changes to zero. In effect, the cushioning action ends before the pressure of the fluid becomes zero. Therefore, the cushion end time in FIG. 3 is the time when the pressure starts to rapidly decrease to zero. At this time, the measured value of the displacement-velocity detection sensor 50 is not zero. The data processing device 90 extracts the time at which the pressure change is larger than a preset value from the data collected by the data collecting device 80 . The value of the displacement-velocity detection sensor 50 corresponding to the extracted time is stored as the cushion end velocity.

Now extract the cushion start velocity. Referring to FIG. 3 , the cushion start speed is the speed at the end of the constant velocity section and can be viewed as the cushion start speed. Accordingly, the speed of the constant speed section may be replaced with the cushion start speed. In order to obtain the cushion start speed, the stroke of the cushion section is input to the data processing device 90 in advance. The stroke of the cushion section is a value that can be known in advance in terms of design specifications. In the process of obtaining the cushion end speed, the cushion end time was extracted. The displacement value of the piston corresponding to the cushion end time is extracted and stored as the maximum stroke (displacement). The data processing device 90 obtains a value obtained by subtracting the previously input stroke of the cushion section from the maximum stroke. The stroke value calculated in this way corresponds to the cushion start displacement. Now extract the velocity value of the piston at the time corresponding to the cushion start displacement. Since the speed value of the piston is collected in real time by the displacement-velocity detection sensor 50, it can be easily extracted by specifying the time. The piston speed value extracted in this way is stored as the cushion start speed value. Now, cushion start and cushion end velocities have been extracted. The deceleration rate is a value obtained by subtracting the cushion end speed from the cushion start speed as a percentage of the cushion start speed. Through this process, the deceleration rate that occurs during the cushion action can be obtained.

Now, a cushion performance analysis method using the cushion performance analysis device including the components as described above will be described in detail.

First, the cushioning function of the hydraulic cylinder 20 must be performed in order to analyze the cushioning performance. That is, a constant velocity movement step of moving the piston at a constant velocity by moving the fluid into and out of the cylinder 22 is performed. A deceleration step is performed after the constant velocity movement step. The deceleration step is a step in which the cushion function is performed. That is, in the deceleration step, the piston is decelerated by a cushion action.

During the deceleration step, the cushion end speed extraction for extracting, as the cushion end speed, the speed of the piston at a point in time when the change in absolute value of the first pressure sensor 60 or the second pressure sensor 70 is greater than a predetermined value. Step S100 is performed.

After the cushion end speed extraction step (S100), a maximum stroke value extraction step (S200) is performed. In the maximum stroke value extraction step (S200), the displacement value measured by the displacement-velocity detection sensor 50 corresponding to the time having the cushion end speed value is extracted as the maximum stroke value.

After the maximum stroke value extraction step (S200), a cushion start speed extraction step (S300) is performed. In the cushion start speed extraction step ( S300 ), a piston speed value at a time corresponding to a displacement value obtained by subtracting a pre-input cushion stroke value from the maximum stroke value is extracted as a cushion start speed.

The deceleration rate calculation step (S400) is performed after the cushion start speed extraction step (S300). In the deceleration rate calculation step (S400), a value obtained by calculating a difference between the cushion start speed and the cushion end speed as a percentage of the cushion start speed is stored as the deceleration rate. The deceleration rate is a major factor for measuring cushion performance, and it is preferable that it can be output as a numerical value or graphic on a monitor.

As described above, the cushion performance measuring device and cushion performance measuring method of a hydraulic cylinder according to the present invention are a cushion end speed and a cushion start speed using the value of a displacement-speed detection sensor that simultaneously measures the speed and displacement value of a piston in real time By extracting , it provides the effect of quickly and accurately calculating the deceleration rate, which is a major factor in determining cushion performance.

In addition, since the cushion performance measurement device and cushion performance measurement method of a hydraulic cylinder according to the present invention can calculate a deceleration rate in real time, there is an effect of providing an environment in which an optimal cushion condition can be applied in a short time.

In addition, the cushion performance measuring device and cushion performance measuring method of the hydraulic cylinder according to the present invention obtain and store the pressure of the fluid, the speed and displacement of the piston in real time, thereby providing data for the utilization of big data in designing the hydraulic cylinder cushion structure. Provides actionable effects that can be built.

In the above, the present invention has been described in detail with preferred embodiments, but the present invention is not limited to the above embodiments, and many variations are possible within the technical spirit of the present invention by those skilled in the art. is clear

10: Cushion performance analysis device
20: hydraulic cylinder
22: Cylinder
26: load
28: head cover
30: rod cover
50: displacement-velocity detection sensor
52: wire
54: wire jig
60: first pressure sensor
70: second pressure sensor
80: data collection device
90: data processing unit
S100: Cushion end speed extraction step
S200: Maximum stroke value extraction step
S300: Cushion start speed extraction step
S400: Deceleration Rate Calculation Step

Claims (4)

hollow cylinder;
a rod installed inside the cylinder to move integrally with a piston installed to be movable in the longitudinal direction of the cylinder;
a head cover installed at one end of the cylinder and provided with a passage through which fluid flows;
a rod cover installed at the other end of the cylinder and provided with a passage through which fluid flows; and
In the hydraulic cylinder device provided with a cushion portion for preventing the piston from rapidly colliding with the head cover and the rod cover,
A displacement-velocity detection sensor for measuring the displacement and speed of the piston in real time is installed in the cylinder,
A first pressure sensor for measuring the pressure of the fluid between the piston and the head cover is installed on the head cover,
A second pressure sensor for measuring the pressure of the fluid between the piston and the rod cover is installed on the rod cover,
a data collection device receiving and storing measured values of the displacement-velocity detection sensor, the first pressure sensor, and the second pressure sensor; and
A cushion performance analysis device for a hydraulic cylinder, characterized in that it comprises a data processing device for calculating the deceleration rate generated in the cushioning process in real time from the measured values stored in the data collection device. According to claim 1,
Wherein the data processing device is configured to extract the speed of the piston as the cushion end speed at a time when the change in the absolute value of the first pressure sensor or the second pressure sensor is greater than a predetermined value. Of the hydraulic cylinder, characterized in that Cushion performance analysis device. According to claim 2,
In the data processing, the device extracts a displacement value measured by a displacement-velocity detection sensor corresponding to a time having the cushion end speed value as a maximum stroke value,
A cushion performance analysis device for a hydraulic cylinder, characterized in that configured to extract the speed of the piston as the cushion start speed for the speed value of the piston at a time corresponding to the displacement value obtained by subtracting the cushion stroke value input in advance from the maximum stroke value. A cushion performance analysis method using the cushion performance analyzer of the hydraulic cylinder according to claim 1,
Moving the piston at a constant speed by entering and exiting the cylinder, and operating the hydraulic cylinder so that the piston is decelerated by a cushioning action,
a cushion end speed extraction step of extracting, as a cushion end speed, a speed of a piston at a point in time when a change in an absolute value of the first pressure sensor or the second pressure sensor is greater than a predetermined value due to the cushion action;
a maximum stroke value extraction step of extracting, as a maximum stroke value, a displacement value measured by a displacement-velocity detection sensor corresponding to a time having the cushion end velocity value, which is performed after the cushion end velocity extracting step;
a cushion start speed extraction step, which is performed after the maximum stroke value extraction step, and extracts, as a cushion start speed, a speed value of the piston at a time corresponding to a displacement value obtained by subtracting a cushion stroke value input in advance from the maximum stroke value; and
A method for analyzing cushion performance of a hydraulic cylinder, comprising a deceleration rate calculation step of storing a value obtained by calculating a difference between the cushion start speed and the cushion end speed as a percentage of the cushion start speed as a deceleration rate.

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