Hydraulic cylinder with piston rod displacement detection function

Abstract

The hydraulic cylinder with the piston rod displacement detection function comprises a cylinder barrel, a cylinder bottom, a piston rod and a piston, a non-metal plug and a displacement detection assembly are installed on the cylinder bottom, a signal transmitting and receiving unit is arranged on the displacement detection assembly, and the signal transmitting and receiving unit is externally connected with a centralized control center, a controller, a driver and an electromagnetic reversing valve; the signal transmitting and receiving unit is coaxial with the inner connecting hole, the displacement of the piston rod is obtained by calculating the interval between transmitted sound waves and returned sound waves, meanwhile, displacement data is transmitted to the controller and the centralized control center, and the controller receives a hydraulic cylinder stroke instruction sent by the centralized control center and controls the hydraulic cylinder stroke instruction to move. And then, the driver is used for controlling the opening and closing of the electromagnetic reversing valve and controlling the liquid inlet of the upper cavity or the lower cavity of the hydraulic cylinder. The hydraulic cylinder can realize non-contact real-time detection of the displacement of the piston.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic cylinder equipment, and in particular to a hydraulic cylinder with a piston rod displacement detection function. Background Art

[0002] With the improvement of the automation level of coal mines, the overall movement accuracy of hydraulic supports has become higher, especially the pushing and pulling movements of the push jacks, which directly affect the straightness of the working surface. The value of the push jack stroke sensor is the key reference value for automatic pushing and pulling. If the stroke sensor fails, it will not be possible to accurately control the movement of the push jack and automatically straighten the working surface. Other guard jacks, balance jacks, etc., can only realize automatic and accurate control of the hydraulic support posture after integrating the stroke sensor and forming a closed-loop control with the electro-hydraulic controller.

[0003] In the prior art, there are mainly contact and non-contact methods for measuring the stroke of the piston rod in the hydraulic cylinder. Draw-wire sensors, magnetostrictive sensors, laser sensors, etc. are usually used to detect the displacement of the piston rod in the hydraulic cylinder. However, the use of draw-wire sensors to detect the stroke of the piston rod has low reliability, and long-term operation will cause a decrease in accuracy and difficult maintenance; magnetostrictive sensors are contact sensors, which are expensive and large in size. The use of non-contact laser sensors to measure the stroke of the piston rod requires a large amount of processing on the piston, and the installation and maintenance of the measuring device are difficult. In addition, during measurement, the laser sensor is usually installed on the outside of the hydraulic cylinder. Hydraulic cylinders are commonly used in heavy industry, so the detection device is easily damaged and is also limited by the installation and use scenario environment.

[0004] The invention patent with the authorization announcement number CN221278149U discloses a hydraulic cylinder with a piston rod displacement detection function, including a cylinder body, a moving mechanism and a disassembly mechanism; the cylinder body is movably connected to a piston rod, and a scale line is fixedly provided on one side of the outer wall of the piston rod; the moving mechanism includes a motor and a plate body respectively fixedly connected to the outer side of the cylinder body, the output shaft of the motor is fixedly connected to a screw rod, and the plate body is slidably connected to the rod body. The hydraulic cylinder with the piston rod displacement detection function can detect the displacement state of the piston rod, so that the displacement of the piston rod can be detected more promptly, thereby ensuring that the working efficiency of the hydraulic cylinder will not be affected. However, the device has a weak anti-interference ability. Summary of the invention

[0005] In order to provide a hydraulic cylinder with a non-contact real-time piston displacement detection function that has high reliability, small processing volume, strong adaptability, and convenient installation and maintenance, the technical solution adopted by the present invention is: a hydraulic cylinder with a piston rod displacement detection function, comprising a cylinder barrel, a cylinder bottom, a piston rod arranged inside the cylinder barrel, and a piston arranged at the lower end of the piston rod; A non-metal plug installation cavity communicating with the cylinder barrel is provided at one end of the cylinder bottom, and a detection component installation hole is provided along a radial direction at one side of the cylinder bottom, wherein the detection component installation hole and the non-metal plug installation cavity are connected via an inner connection hole; A non-metal plug is arranged in the non-metal plug installation cavity, a displacement detection component is arranged in the detection component installation hole, the displacement detection component comprises a base body and a signal transmitting and receiving unit arranged on the base body, and the signal transmitting and receiving unit is externally connected to a centralized control center, a controller, a driver and an electromagnetic reversing valve; The signal transmitting and receiving unit is coaxial with the inner connecting hole, and obtains the displacement of the piston rod by calculating the interval between the transmitted and returned sound waves, and transmits the displacement data to the controller and the centralized control center at the same time. The controller receives the hydraulic cylinder stroke command issued by the centralized control center, and determines whether the hydraulic cylinder reaches the stroke required to extend or retract, and then controls the opening and closing of the electromagnetic reversing valve through the driver to control the liquid inlet to the upper chamber or lower chamber of the hydraulic cylinder in the cylinder barrel.

[0006] Based on the above, in order to facilitate control, a lower chamber joint seat is provided at one end of the cylinder, and an upper chamber joint seat is provided at the other end of the cylinder. The lower chamber joint seat and the upper chamber joint seat are respectively connected to the electromagnetic reversing valve through hydraulic pipelines.

[0007] Based on the above, the cylinder is respectively provided with a lower chamber liquid through hole and an upper chamber liquid through hole, the lower chamber joint seat is connected with the lower chamber liquid through hole, and the upper chamber liquid through hole is connected with the upper chamber joint seat through a liquid through pipe.

[0008] Based on the above, a mounting seat and a wiring port are provided on the top of the base, and a dustproof ring is provided on the mounting seat.

[0009] Based on the above, a guide sleeve is provided on the top of the cylinder.

[0010] Based on the above, in order to avoid damage, sealing rings are respectively installed between the non-metallic plug and the non-metallic plug installation cavity, and between the piston and the cylinder.

[0011] Based on the above, in order to improve the detection accuracy, the center line of the inner connecting hole coincides with the axis of the piston rod.

[0012] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, the hydraulic cylinder with piston rod displacement detection function provided by the present invention can detect the displacement of the piston rod inside the hydraulic cylinder in real time, and transmit the detection results to the controller to achieve accurate control of the telescopic stroke of the hydraulic cylinder and judgment and adjustment of the equipment posture. The advantages are that the sensor is built-in and not easy to damage, not subject to external interference, high measurement accuracy and will not reduce accuracy due to long-term use, the sensor is small in size and cheap, the piston rod does not need to be drilled deep, and is easy to process. It is only connected by two screws and is easy to disassemble and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of a hydraulic cylinder with a piston rod displacement detection function provided by the present invention.

[0014] Figure 2 It is a schematic diagram of the structure of a displacement detection component in a hydraulic cylinder with a piston rod displacement detection function provided by the present invention.

[0015] Figure 3 It is a schematic diagram of the end surface structure of a hydraulic cylinder with a piston rod displacement detection function provided by the present invention.

[0016] Figure 4 It is a schematic diagram of the local structure of a hydraulic cylinder with a piston rod displacement detection function provided by the present invention.

[0017] In the figure: 1. Cylinder bottom; 2. Displacement detection component; 3. Non-metallic plug; 4. Internal connection hole; 5. Non-metallic plug installation cavity; 6. Piston rod; 7. Detection component installation hole; 8. Cylinder barrel; 9. Piston; 10. Lower cavity joint seat; 11. Communication line; 12. Hydraulic pipeline; 13. Upper cavity joint seat; 14. Liquid pipe; 15. Upper cavity liquid hole; 16. Guide sleeve; 17. Central control center; 18. Controller; 19. Driver; 20. Solenoid reversing valve; 21. Wiring port; 22. Mounting seat; 23. Signal transmitting and receiving unit; 24. Connecting ear shaft; 25. Lower cavity liquid hole. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0019] Example 1 This embodiment provides a hydraulic cylinder with a piston rod displacement detection function, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it comprises a cylinder barrel 8, a cylinder bottom 1, a piston rod 6 arranged inside the cylinder barrel 8, and a piston 9 arranged at the lower end of the piston rod 6. Connecting trunnions 24 are arranged on both sides of the cylinder bottom 1.

[0020] A non-metal plug installation cavity 5 is provided at one end of the cylinder bottom 1 and communicates with the cylinder barrel 8. A detection assembly installation hole 7 is provided along a radial direction at one side of the cylinder bottom 1. The detection assembly installation hole 7 is connected to the non-metal plug installation cavity 5 through an inner connection hole 4.

[0021] A non-metal plug 3 is arranged in the non-metal plug installation cavity 5. A displacement detection component 2 is arranged in the detection component installation hole 7. The displacement detection component 2 includes a base and a signal transmitting and receiving unit 23 arranged on the base, and the signal transmitting and receiving unit 23 is externally connected to the centralized control center 17, the controller 18, the driver 19 and the electromagnetic reversing valve 20.

[0022] The signal transmitting and receiving unit 23 is coaxial with the inner connecting hole 4, and obtains the displacement of the piston rod by calculating the interval between the transmitted and returned sound waves, and transmits the displacement data to the controller 18 and the centralized control center 17 through the communication line 11. The controller 18 receives the hydraulic cylinder stroke command issued by the centralized control center 17, and determines whether the hydraulic cylinder reaches the required extension or retraction stroke, and then controls the opening and closing of the electromagnetic reversing valve through the driver to control the liquid inlet to the upper or lower chamber of the hydraulic cylinder in the cylinder barrel.

[0023] For the convenience of control, a lower chamber joint seat 10 is provided at one end of the cylinder 8, and an upper chamber joint seat 13 is provided at the other end of the cylinder 8. The lower chamber joint seat 10 and the upper chamber joint seat 13 are connected to the electromagnetic reversing valve 20 through hydraulic pipelines 12, respectively.

[0024] The cylinder 8 is provided with a lower cavity liquid hole 25 and an upper cavity liquid hole 15, respectively, and the lower cavity joint seat 10 is connected with the lower cavity liquid hole 25. The upper cavity liquid hole 15 is connected with the upper cavity joint seat 13 through a liquid pipe 14. A guide sleeve 16 is provided at the top of the cylinder 8.

[0025] Example 2 This embodiment provides a hydraulic cylinder with a piston rod displacement detection function, which is different from Embodiment 1 in that, in this embodiment, a mounting seat 22 and a wiring port 21 are provided on the top of the base, and a dust ring is provided on the mounting seat 22. To avoid damage, sealing rings are respectively installed between the non-metal plug and the non-metal plug mounting cavity, and between the piston and the cylinder barrel.

[0026] Example 3 This embodiment provides a hydraulic cylinder with a piston rod displacement detection function. The difference from Embodiment 1 is that in this embodiment, in order to improve detection accuracy, the center line of the inner connecting hole coincides with the axis of the piston rod.

[0027] Specifically, the cylinder barrel of the hydraulic cylinder with piston rod displacement detection function provided by the present invention is provided with an upper chamber liquid hole, and the cylinder barrel, cylinder bottom, upper chamber joint seat, lower chamber joint seat, and liquid pipe are welded into an assembly. The upper chamber joint seat is connected to the upper chamber liquid hole through the liquid pipe, and the lower chamber joint seat is connected to the rodless chamber through the lower chamber liquid hole. An inner nest, i.e., a non-metal plug installation cavity, is provided on the right end surface of the cylinder bottom, and a vertical hole, i.e., a detection component installation hole, is drilled on the outer circle, and the inner nest is connected to the vertical hole through the inner connecting hole.

[0028] The non-metal plug is made of thermoplastic or ceramic material, can withstand pressure above 40MPa, is installed in the inner nest of the cylinder bottom, and is separated from the inner connection hole by a seal. The displacement detection component is installed in the vertical hole at the bottom of the cylinder, and a dust ring is installed to effectively protect the sensor from damage. The upper part of the displacement detection component is provided with a mounting seat and a wiring port, and the lower part is provided with a signal transmitting and receiving unit. The mounting seat is fixed to the cylinder bottom by screws, and the wiring port is connected to the controller through a communication line, which is convenient for installation and disassembly.

[0029] The signal transmitting and receiving unit is coaxial with the inner connection hole, and the displacement of the piston rod is obtained by calculating the interval between the transmitted and returned sound waves, and the displacement data is transmitted to the controller at the same time. The controller receives the hydraulic cylinder stroke command issued by the centralized control center and determines whether the hydraulic cylinder has reached the required extension or retraction stroke. Then, the driver controls the opening and closing of the electromagnetic reversing valve to realize the liquid inflow to the upper or lower chamber of the hydraulic cylinder, ensuring that the hydraulic cylinder reaches the required extension or retraction stroke. At the same time, the position or posture of the equipment can also be determined by real-time detection of the hydraulic cylinder stroke.

[0030] Specifically, when the signal transmitting and receiving devices are working, taking the millimeter wave sensor as an example, the basic principle of ranging is that the radar transmits a linear frequency modulation signal, mixes the echo signal with a copy of the transmitted signal to obtain an intermediate frequency signal containing information such as the target distance and speed, and estimates the frequency and phase of the intermediate frequency signal to obtain parameters such as the target distance and speed.

[0031] First, the modulation voltage generated by the digital-to-analog converter (DAC) controls the voltage-controlled oscillator (VCO) to generate a linear frequency modulation signal with a certain bandwidth. After passing through the power divider, two signals are generated. One signal is directly used as the local oscillator signal of the mixer, and the other signal is radiated into free space by the transmitting antenna after passing through the power amplifier.

[0032] When the transmitted signal hits the target during transmission in free space, part of it is absorbed by the target, and the other part is reflected by the target. The reflected signal is called the echo signal. Then, the echo signal is received by the receiving antenna, and after passing through the low-noise amplifier, it is used as the RF input signal of the mixer, and is mixed with the local oscillator signal in the mixer. The output signal is the intermediate frequency signal. Next, the intermediate frequency signal is filtered and amplified, and then collected and converted into a digital signal by the analog-to-digital converter (ADC). Finally, a series of signal processing is performed on the digital signal to obtain information such as the distance and speed of the target.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A hydraulic cylinder with a piston rod displacement detection function, comprising a cylinder barrel, a cylinder bottom, a piston rod arranged inside the cylinder barrel, and a piston arranged at the lower end of the piston rod, characterized in that: A non-metal plug installation cavity communicating with the cylinder barrel is provided at one end of the cylinder bottom, and a detection component installation hole is provided along a radial direction at one side of the cylinder bottom, wherein the detection component installation hole and the non-metal plug installation cavity are connected via an inner connection hole; A non-metal plug is arranged in the non-metal plug installation cavity, a displacement detection component is arranged in the detection component installation hole, the displacement detection component comprises a base body and a signal transmitting and receiving unit arranged on the base body, and the signal transmitting and receiving unit is externally connected to a centralized control center, a controller, a driver and an electromagnetic reversing valve; The signal transmitting and receiving unit is coaxial with the inner connecting hole, and obtains the displacement data of the piston rod by calculating the interval between the transmitted and returned sound waves, and transmits the displacement data to the controller and the centralized control center at the same time. The controller receives the hydraulic cylinder stroke command issued by the centralized control center, and determines whether the hydraulic cylinder reaches the stroke required to extend or retract, and then controls the opening and closing of the electromagnetic reversing valve through the driver to control the liquid inlet to the upper chamber or lower chamber of the hydraulic cylinder in the cylinder barrel.

2. The hydraulic cylinder with piston rod displacement detection function according to claim 1, characterized in that: A lower cavity joint seat is arranged at one end of the cylinder, and an upper cavity joint seat is arranged at the other end of the cylinder. The lower cavity joint seat and the upper cavity joint seat are respectively connected to the electromagnetic reversing valve through hydraulic pipelines.

3. The hydraulic cylinder with piston rod displacement detection function according to claim 2, characterized in that: The cylinder is provided with a lower chamber liquid through hole and an upper chamber liquid through hole respectively. The lower chamber joint seat is connected with the lower chamber liquid through hole, and the upper chamber liquid through hole is connected with the upper chamber joint seat through a liquid through pipe.

4. The hydraulic cylinder with piston rod displacement detection function according to claim 3, characterized in that: A mounting seat and a wiring port are arranged on the top of the base, and a dustproof ring is arranged on the mounting seat.

5. The hydraulic cylinder with piston rod displacement detection function according to claim 4, characterized in that: A guide sleeve is arranged on the top of the cylinder.

6. The hydraulic cylinder with piston rod displacement detection function according to claim 5, characterized in that: Sealing rings are respectively installed between the non-metal plug and the non-metal plug installation cavity, and between the piston and the cylinder.

7. The hydraulic cylinder with piston rod displacement detection function according to claim 6, characterized in that: The center line of the inner connecting hole coincides with the axis line of the piston rod.

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