Hydraulic cylinder with ceramic piston rod absolute displacement detection function

Abstract

The present application relates to the field of hydraulic cylinder, disclose a kind of hydraulic cylinder with ceramic piston rod absolute value displacement detection function, including radial linkage mechanism is located ceramic piston rod, for forming the synchronous displacement structure of magnetic displacement detection;Linkage limiting mechanism is located hydraulic cylinder body, cooperates strip magnetic scale for forming the limiting structure of synchronous ceramic piston rod displacement of detection structure;Output detection mechanism is located linkage limiting mechanism, cooperates strip magnetic scale, limiting sleeve frame, guide inclined table and arc magnetic scale for forming the displacement detection structure of synchronous displacement.It is avoided that stroke loss or mechanical hysteresis in transmission process by using rigid connection, while guide carriage is subjected to the pure physical geometric constraint of arc limiting path inner wall, cleverly separate the linear shuttle slip of strip magnetic scale and circumferential deflection thrust in space, the embedding sliding of strip magnetic scale in guide carriage and the circumferential rotation of guide carriage along arc track are not interfered with each other.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder technology, specifically to a hydraulic cylinder with absolute displacement detection function of ceramic piston rod. Background Technology

[0002] Hydraulic cylinders, as core actuators widely used in engineering machinery, metallurgical equipment, and automated production lines, are primarily used to convert the pressure energy of liquids into linear reciprocating mechanical energy. With the continuous advancement of industrial automation and intelligent manufacturing technologies, systems are placing higher demands on the precise control of hydraulic actuators. In many complex operating conditions, it is not only necessary to acquire real-time and accurate linear extension and retraction displacement data of the ceramic piston rod, but also to monitor the radial deflection angle generated by the ceramic piston rod under external torque, thereby providing reliable data support for equipment attitude compensation and multi-dimensional closed-loop control.

[0003] Currently, the industry commonly uses external cable displacement sensors or unidirectional magnetic / optical scales to detect hydraulic cylinder displacement. However, these conventional detection devices typically only possess single-dimensional linear monitoring capabilities. When the ceramic piston rod rotates or deflects radially during actual operation, single-dimensional detection elements not only fail to capture this displacement, but their rigid connection parts are also highly susceptible to mechanical jamming, interference, and even structural damage due to torsional stress. If independent linear and rotational dual detection systems are installed externally, it not only leads to a bulky overall equipment and cumbersome wiring, but the mechanical coupling between multi-dimensional motions can easily cause transmission lag, making it difficult to achieve synchronous acquisition of linear and rotational signals.

[0004] Furthermore, hydraulic equipment typically operates in harsh industrial environments filled with dust, oil, metal shavings, and corrosive media. On one hand, the surface of the long-exposed ceramic piston rod easily accumulates hard particles from the environment during frequent reciprocating extension and retraction. These impurities enter the cylinder end as the ceramic piston rod retracts, drastically accelerating the wear of internal sealing components, leading to hydraulic oil leakage and significantly shortening the cylinder's lifespan. On the other hand, high-precision external displacement detection elements are highly dependent on the physical cleanliness of their surfaces. Once dust or oil film adheres, electrostatic adsorption and physical adhesion effects severely weaken the penetration rate of magnetic field lines, causing frequent loss or misreading of electrical pulse signals, resulting in a precipitous decline in detection accuracy. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a hydraulic cylinder with absolute displacement detection function for ceramic piston rods. This solves the problems of existing external displacement detection schemes for hydraulic cylinders, which struggle to achieve non-interference synchronous acquisition of linear and rotational composite displacements, and the exposed ceramic piston rods and high-precision detection elements being highly susceptible to corrosion from dust and oil under harsh working conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a hydraulic cylinder with absolute displacement detection function of a ceramic piston rod, comprising: Hydraulic cylinder body, used to form the cylinder body structure of a hydraulic cylinder; The docking end is located in the hydraulic cylinder and is used to form the cylinder mounting end of the hydraulic cylinder; The output end is located in the hydraulic cylinder and is used to form the mounting end of the ceramic piston rod of the hydraulic cylinder; The ceramic piston rod is located in the hydraulic cylinder and is the ceramic piston rod part used to form the hydraulic cylinder; The diaphragm linkage mechanism is located on the ceramic piston rod and is used to form a synchronous displacement structure for magnetic displacement detection; The linkage limit mechanism is located in the hydraulic cylinder and works with the strip magnetic grating ruler to form a limit structure for detecting the synchronous displacement of the ceramic piston rod. The output detection mechanism is located in the linkage limit mechanism, and together with the strip magnetic scale, limit sleeve, guide ramp and arc magnetic scale, it forms a displacement detection structure for synchronous displacement. The sealed air compressor mechanism is located in the hydraulic cylinder, and works with the linkage ring sleeve and the air inlet expansion bucket to provide synchronous protection for the ceramic piston rod and to generate an air-blowing dust removal structure during contraction.

[0007] Preferably, the ceramic piston rod extends into the hydraulic cylinder to form a basic hydraulic cylinder structure. The diaphragm linkage mechanism is mounted on the end of the ceramic piston rod and moves synchronously with the ceramic piston rod, while being the same length as the ceramic piston rod. The linkage limit mechanism is mounted on one side of the end of the hydraulic cylinder. The output detection mechanism is mounted on the linkage limit mechanism and can move synchronously with the circumferential displacement of the diaphragm linkage mechanism. The sealing air compressor mechanism is mounted on the hydraulic cylinder and docks with the diaphragm linkage mechanism.

[0008] Preferably, the diaphragm linkage mechanism includes a linkage ring sleeve, which is fixed to the top end of the ceramic piston rod, and an extension suspension is fixed to the side of the linkage ring sleeve facing the linkage limiting mechanism, and a strip magnetic grating ruler is mounted and fixed to the end of the extension suspension.

[0009] Preferably, the linkage limiting mechanism includes a limiting sleeve, which is fixed to one side of the top of the hydraulic cylinder. An inclined guide platform with an inner side is fixed to the outer side of the limiting sleeve. An arc-shaped limiting channel is fixed inside the limiting sleeve and forms an arc-shaped guiding structure. An arc-shaped magnetic grating ruler is set inside the limiting sleeve and arranged in parallel with the arc-shaped limiting channel. The arc-shaped limiting channel and the arc-shaped magnetic grating ruler allow the strip magnetic grating ruler to pass through and fit together.

[0010] Preferably, the output detection mechanism includes a guide slide, which is embedded in the limiting sleeve and moves along the arc-shaped limiting track. The guide slide is sleeved on the strip magnetic ruler and moves circumferentially with the strip magnetic ruler.

[0011] Preferably, the sealed air compressor mechanism includes a stationary side frame, which is fixed to the side of the hydraulic cylinder and extends to the output port of the hydraulic cylinder at the top. A sealing collar is fixed to the bent end of the stationary side frame and is also fixed to the output port of the hydraulic cylinder. A stacked clamping ring is fixed to the top of the stationary side frame, with the topmost stacked clamping ring fixed to the linkage ring, so that the stacked clamping ring completely covers the exposed surface of the ceramic piston rod. An exhaust outlet pipe is fixed to the side wall of the sealing collar facing the air intake hopper, and a connecting slot is provided between the exhaust outlet pipe and the inside of the stacked clamping ring.

[0012] Preferably, the docking end is located at the end of the hydraulic cylinder, while the output end is located in the output port direction of the hydraulic cylinder, and a ceramic piston rod is fixed inside.

[0013] Preferably, the air intake hopper is fixed to the inner port of the limiting sleeve to form an air outlet.

[0014] Preferably, the first reading head element is fixed on the outside of the guide slide and positioned in the output direction of the guide ramp, with the detection end of the first reading head element suspended and attached to the surface of the arc-shaped magnetic scale, while the second reading head element is fixed on the inside of the guide slide, with the inspection end of the second reading head element attached to the inner side of the strip-shaped magnetic scale.

[0015] Preferably, the surface of the ceramic piston rod is machined with two sets of equally spaced annular grooves along the axial direction, wherein the spacing of the first set of annular grooves is a reference value, and the spacing of the second set of annular grooves is greater than the reference value. The relative distance between the two sets of annular grooves changes cyclically along the axial direction of the ceramic piston rod, and within each cycle, the relative distance between the two sets of grooves gradually increases from the initial value and then gradually decreases back to the initial value; The sensor detection unit is located at the output port of the hydraulic cylinder. Its detection surface width is greater than twice the reference value. It is used to capture the distance relationship between four adjacent grooves in order to calculate the absolute displacement position of the ceramic piston rod.

[0016] This invention provides a hydraulic cylinder with absolute displacement detection function for a ceramic piston rod. It has the following beneficial effects: 1. This invention avoids stroke loss or mechanical lag during transmission by utilizing rigid connection. At the same time, the guide carriage is subject to the pure physical geometry constraint of the inner wall of the arc-shaped limiting track, which cleverly separates the linear shuttle sliding of the strip magnetic grating ruler from the circumferential deflection thrust in space. When the hydraulic cylinder performs the compound action, the embedded sliding of the strip magnetic grating ruler inside the guide carriage and the circumferential rotation of the guide carriage along the arc track do not interfere with each other.

[0017] 2. This invention utilizes the natural retraction action of the hydraulic cylinder to cause the ceramic piston rod to shift and pull the linkage sleeve downwards synchronously, forcing the clamping sleeve to buckle and fold. This sudden drop in volume caused by mechanical displacement is directly converted into high-pressure potential energy of the internal air. Subsequently, the high-pressure airflow is guided by the exhaust pipe, accelerated by the intake expansion bucket, and guided by the guide ramp, ultimately transforming into a high-speed jet output to the detection interface. The triggering, energy storage, and directional release of the entire dust removal process are linked to the mechanical contraction action of the hydraulic cylinder, enabling the automatic removal of dust and oil stains using the byproducts of the action while the equipment is in daily operation.

[0018] 3. During the actual reciprocating extension and retraction process of the equipment, the flexible covering structure composed of the stationary side frame, sealing ring and overlapping ring always wraps around the outside of the ceramic piston rod. The overlapping ring relies on its accordion-like folding characteristics to closely follow the displacement trajectory of the linkage ring and adjust its deformation, and moves in sync with the ceramic piston rod, thus establishing a dynamic physical barrier for the exposed metal surface of the ceramic piston rod.

[0019] 4. This invention only requires machining two sets of equidistant annular grooves on the surface of the ceramic piston rod, eliminating the need for complex multiple sets of non-equidistant grooves. The machining process is simple, and the manufacturing cost is significantly reduced. The absolute position is uniquely determined by the combination of the distances of four adjacent grooves. The algorithm is simple, the computational load is small, the real-time performance is good, and there is no need for zeroing calibration after power failure. The detection accuracy is high, and the groove identification code depends entirely on the geometric distribution relationship of the annular grooves. When the ceramic piston rod rotates around the axis during extension and retraction, the relative distance between the grooves remains unchanged. Therefore, the detection result is not affected by the rotation of the ceramic piston rod, making it suitable for hydraulic systems with torque or rotation conditions. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of the main structure of the present invention. Figure 1 ; Figure 2 This is a three-dimensional schematic diagram of the main structure of the present invention. Figure 2 ; Figure 3 This is a three-dimensional unfolded schematic diagram of the main structure of the present invention; Figure 4 This is a schematic diagram of the main structural components of the present invention; Figure 5This is a schematic diagram of the diaphragm linkage mechanism of the present invention; Figure 6 This is a schematic diagram of the hydraulic cylinder structure assembly of the present invention. Figure 1 ; Figure 7 This is a schematic diagram of the hydraulic cylinder structure assembly of the present invention. Figure 2 ; Figure 8 This is a schematic diagram of the linkage limiting mechanism of the present invention; Figure 9 This is a schematic diagram of the output detection mechanism structure of the present invention. Figure 10 This is a schematic diagram of the installation of the sealed air compressor mechanism of the present invention; Figure 11 This is a schematic diagram of another detection method of the present invention; Figure 12 This is a schematic diagram showing the distribution of the annular groove structure of the ceramic piston rod of the present invention.

[0021] The components include: 1. Hydraulic cylinder; 2. Connecting end; 3. Output end; 4. Ceramic piston rod; 5. Diameter linkage mechanism; 6. Linkage limit mechanism; 7. Output detection mechanism; 8. Sealed air compressor mechanism; 51. Linkage ring sleeve; 52. Extension suspension; 53. Strip magnetic grating ruler; 61. Limiting sleeve; 62. Intake expansion hopper; 63. Guide ramp; 64. Arc-shaped limiting track; 65. Arc-shaped magnetic grating ruler; 71. Guide slide; 72. Reading magnetic head element one; 73. Reading magnetic head element two; 81. Stationary side frame; 82. Sealing ring; 83. Clamping ring sleeve; 84. Exhaust output end pipe. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides two preferred displacement detection implementation methods. Both methods are based on the same hydraulic cylinder main structure (including core components such as the hydraulic cylinder 1 and the ceramic piston rod 4), and both share the common technical objective of accurately detecting absolute displacement even when the ceramic piston rod rotates radially. The two implementation methods are described in detail below with reference to the accompanying drawings.

[0024] Please see the appendix Figure 1 -Appendix Figure 3This invention provides a hydraulic cylinder with absolute displacement detection function of ceramic piston rod, comprising: a hydraulic cylinder 1 for forming the cylinder body structure of the hydraulic cylinder; a docking end 2 located in the hydraulic cylinder 1 for forming the cylinder body mounting end of the hydraulic cylinder; an output end 3 located in the hydraulic cylinder 1 for forming the mounting end of the ceramic piston rod of the hydraulic cylinder; and a ceramic piston rod 4 located in the hydraulic cylinder 1 for forming the ceramic piston rod portion of the hydraulic cylinder. The docking end 2 is located at the end of the hydraulic cylinder 1, while the output end 3 is located in the output port direction of the hydraulic cylinder 1, and the ceramic piston rod 4 is fixed inside the cylinder. The ceramic piston rod 4 extends into the hydraulic cylinder 1 to form a basic hydraulic cylinder structure. Please see the appendix Figure 3 -Appendix Figure 5 The diaphragm linkage mechanism 5 is located on the ceramic piston rod 4 and is used to form a synchronous displacement structure for magnetic displacement detection. The diaphragm linkage mechanism 5 is mounted on the end of the ceramic piston rod 4 and moves synchronously with the ceramic piston rod 4, while being the same length as the ceramic piston rod 4. Please see the appendix Figure 4 -Appendix Figure 5 The axial linkage mechanism 5 includes a linkage ring sleeve 51, which is fixed to the top end of the ceramic piston rod 4. An extension suspension 52 is fixed to the side of the linkage ring sleeve 51 facing the linkage limiting mechanism 6, and a strip magnetic grating ruler 53 is mounted and fixed to the end of the extension suspension 52. The axial thrust or radial torque of the ceramic piston rod 4 acts directly on the linkage ring sleeve 51, driving the linkage ring sleeve 51 to produce synchronous linear sliding or coaxial rotation. The linkage ring sleeve 51 transmits the received mechanical kinetic energy laterally through the extension suspension 52 on the side. Utilizing the cantilever support of the extension suspension 52, the strip magnetic grating ruler 53 is forced to perform a constant-speed linear sliding outside the hydraulic cylinder that is completely parallel to the ceramic piston rod 4, or to perform a circular deflection with the ceramic piston rod 4 as the center, converting the internal displacement into the precise physical trajectory of the external component.

[0025] Please see the appendix Figure 4 -Appendix Figure 5 The linkage limiting mechanism 6 is located in the hydraulic cylinder 1 and works with the strip magnetic grating ruler 53 to form a limiting structure for the synchronous displacement of the ceramic piston rod of the detection structure. The linkage limiting mechanism 6 is mounted on one side of the end of the hydraulic cylinder 1. The linkage limiting mechanism 6 applies a forced constraint on the spatial attitude of the strip magnetic grating ruler 53 that follows the displacement of the ceramic piston rod 4. When the strip magnetic grating ruler 53 moves linearly or swings in a circular motion in the external space, the physical structure of the linkage limiting mechanism 6 guides and limits its range of movement. Please see the appendix Figure 4 -Appendix Figure 9The linkage limiting mechanism 6 includes a limiting sleeve 61, which is fixed to the top side of the hydraulic cylinder 1. An inwardly inclined guide ramp 63 is fixed to the outer side of the limiting sleeve 61. An arc-shaped limiting channel 64 is fixed inside the limiting sleeve 61, forming an arc-shaped guiding structure. An arc-shaped magnetic grating ruler 65 is disposed inside the limiting sleeve 61 and arranged parallel to the arc-shaped limiting channel 64. A strip-shaped magnetic grating ruler 53 passes through and fits into the arc-shaped limiting channel 64 and the arc-shaped magnetic grating ruler 65. When the limiting sleeve 61 moves in a straight line, its direction of movement is constrained by the parallel of the inner wall of the limiting sleeve 61. If the strip magnetic grid ruler 53 rotates and deflects, its trajectory is forcibly guided by the curved surface structure of the arc-shaped limiting channel 64. It slides in a pure arc along the annular channel formed by the parallel arc-shaped limiting channel 64 and the arc-shaped magnetic grid ruler 65. At the same time, the guide ramp 63 on the outside of the limiting sleeve 61 uses its inner inclined surface to provide physical refraction guidance for the subsequent airflow jet, and cooperates to complete the pre-movement preparation for air blowing cleaning. Please see the appendix Figure 9 -Appendix Figure 10 The air intake hopper 62 is fixed to the inner port of the limiting sleeve 61 to form an air outlet. The air intake hopper 62 uses its trumpet-shaped internal cavity structure to collect the compressed airflow introduced from the outside. When the high-pressure airflow rushes into the air intake hopper 62, the gradually narrowing inner wall shape of the air intake hopper 62 produces a physical compression effect on the airflow, forcing the flow rate of gas molecules to increase sharply in this area and spray directly towards the internal channel of the limiting sleeve 61, providing high-pressure airflow to remove the adhering particles on the surface of the detection element.

[0026] Please see the appendix Figure 9 -Appendix Figure 10 The output detection mechanism 7 is located on the linkage limiting mechanism 6. It works with the strip magnetic scale 53, the limiting sleeve 61, the guide inclined platform 63 and the arc magnetic scale 65 to form a displacement detection structure for synchronous displacement. The output detection mechanism 7 is mounted on the linkage limiting mechanism 6 and can synchronously follow the circumferential displacement of the diameter linkage mechanism 5. Please see the appendix Figure 9 -Appendix Figure 10 The output detection mechanism 7 includes a guide slide 71, which is embedded in the limiting sleeve 61 and moves along the arc-shaped limiting channel 64. The guide slide 71 is sleeved on the strip magnetic ruler 53 and moves circumferentially with the strip magnetic ruler 53. When the strip magnetic ruler 53 deflects circumferentially, it applies a tangential pushing force to the guide slide 71. After being subjected to force, the guide slide 71 is forcibly constrained by the pure arc-shaped inner wall of the arc-shaped limiting channel 64 and can only perform precise circumferential sliding along the trajectory of the arc-shaped limiting channel 64. During this sliding process, the guide slide 71 is continuously sleeved on the strip magnetic ruler 53, so that while the strip magnetic ruler 53 pushes the guide slide 71 to rotate, it can still make linear embedding displacement inside the guide slide 71. Please see the appendix Figure 9 -Appendix Figure 10 The first reading head element 72 is fixed on the outside of the guide slide 71 and positioned in the output direction of the guide ramp 63. The detection end of the first reading head element 72 is suspended and attached to the surface of the arc-shaped magnetic grating 65. The second reading head element 73 is fixed on the inside of the guide slide 71, and the inspection end of the second reading head element 73 is attached to the inner side of the strip-shaped magnetic grating 53.

[0027] Please see the appendix Figure 7 -Appendix Figure 10 The sealed air compressor mechanism 8 is located on the hydraulic cylinder 1, and works with the linkage ring 51 and the air inlet expansion hopper 62 to provide synchronous protection for the ceramic piston rod and to generate an air blowing cleaning structure during contraction. The sealed air compressor mechanism 8 is mounted on the hydraulic cylinder 1 and is connected to the diameter linkage mechanism 5. Please see the appendix Figure 7 -Appendix Figure 10 The sealed air compressor mechanism 8 includes a stationary side frame 81, which is fixed to the side of the hydraulic cylinder 1 and extends to the output port of the hydraulic cylinder 1 with a curved top. A sealing collar 82 is fixed to the curved end of the stationary side frame 81 and is also fixed to the output port of the hydraulic cylinder 1. A stacked clamping ring sleeve 83, which is folded and joined sequentially, is fixed to the top of the stationary side frame 81. The topmost stacked clamping ring sleeve 83 is fixed to the linkage ring sleeve 51, so that the stacked clamping ring sleeve 83 completely covers the exposed surface of the ceramic piston rod 4. The linkage ring sleeve 51 and... As the ceramic piston rod 4 retracts towards the hydraulic cylinder 1, a longitudinal downward thrust is applied to the top clamping ring sleeve 83. Due to the static side frame 81 and sealing ring 82 providing a static reaction force at the bottom, the clamping ring sleeve 83 is compressed and buckles and gradually stacks and closes. During the extension and retraction process, the clamping ring sleeve 83 always maintains a dynamic physical shield around the exposed outer wall of the ceramic piston rod 4, preventing external impurities from entering. At the same time, its folding action greatly compresses the volume of the internal sealed cavity, causing the air pressure inside the cavity to rise rapidly. Please see the appendix Figure 7 -Appendix Figure 10 The sealing collar 82 has an exhaust outlet pipe 84 fixed to its side wall facing the air intake hopper 62. The exhaust outlet pipe 84 and the inside of the clamping ring 83 are connected by a connecting slot. The extremely high pressure airflow generated inside the clamping ring 83 due to the sudden reduction in volume is rapidly discharged outward through the connecting slot and directly injected into the inner cavity of the exhaust outlet pipe 84. The exhaust outlet pipe 84 constrains and directs the flow of this high pressure gas, preventing it from ineffectively diffusing into the external environment and accurately guiding the airflow to the side wall area where the air intake hopper 62 is located. With the rigid support of the sealing collar 82, the exhaust outlet pipe 84 establishes a stable gas delivery channel.

[0028] The above describes the displacement detection implementation method based on the mechanical linkage structure of the present invention. As another preferred implementation method based on the aforementioned hydraulic cylinder main structure, the difference between this implementation method and Embodiment 1 lies in the specific form of the displacement detection module. Please see Figure 11 as well as Figure 12 In this embodiment, the surface of the ceramic piston rod 4 is machined with two sets of equally spaced annular grooves along the axial direction. The spacing of the first set of annular grooves is a reference value D, and the spacing of the second set of annular grooves is greater than the reference value D. The relative distance between the two sets of annular grooves changes cyclically along the axial direction of the ceramic piston rod 4. In each cycle, the relative distance between the two sets of grooves gradually increases from the initial value, reaches the maximum value, and then gradually decreases back to the initial value. Through this cyclic arrangement, long-range absolute position detection can be achieved within the limited length of the ceramic piston rod 4.

[0029] The sensor detection unit 9 is fixedly installed at the output port of the hydraulic cylinder 1. It integrates a magnet and a magnetic sensor. The detection surface width of the sensor detection unit 9 is more than twice the reference value D, thereby ensuring that at least four adjacent annular grooves can be captured in the detection surface at any detection position. When the ceramic piston rod 4 extends or retracts, the sensor detection unit 9 scans the distribution of the annular grooves below it in real time to obtain the spacing combination between the four adjacent grooves. Since the spacing of each set of grooves changes according to the above-mentioned cyclic law, the spacing combination of any four adjacent grooves is unique in the entire stroke range of the ceramic piston rod 4. Therefore, the sensor detection unit 9 can directly calculate the current absolute displacement position of the ceramic piston rod 4 according to the pre-stored mapping relationship, and there is no need to zero-calibrate after power failure.

[0030] As a specific example, assuming the detection surface width of sensor detection unit 9 is 85 mm, the maximum reference distance between the two sets of annular grooves can be set to 43 mm. In the initial position, the minimum distance D between the two sets of annular grooves is 4 mm. Subsequently, the spacing of the first set of grooves gradually increases from 20 mm and 21 mm to 40 mm, and the spacing of the second set of grooves gradually increases from 21 mm and 22 mm to 41 mm. When the reference distance between the annular grooves reaches 40 mm and 41 mm, the detectable effective stroke exceeds 8 meters. If the detection surface width of the sensor detection unit is 115 mm, the detectable stroke can reach 22 meters, which can meet the displacement detection requirements of most hydraulic cylinders.

[0031] Furthermore, since the detection in this embodiment relies entirely on the geometric distribution of the annular grooves, even if the ceramic piston rod 4 rotates around the axis during the extension and retraction process, it will not change the relative spacing between the annular grooves. Therefore, the detection results are not affected by the rotation of the ceramic piston rod 4.

[0032] This invention also provides a working principle for a hydraulic cylinder with absolute displacement detection function of ceramic piston rod, comprising the following: The hydraulic system injects pressurized hydraulic oil into the internal chamber of the hydraulic cylinder 1 through the docking end 2. The fluid pressure of the hydraulic oil directly acts on the inner end face of the ceramic piston rod 4, pushing the ceramic piston rod 4 to overcome frictional resistance and extend linearly outward from the output end 3 along the central axis of the inner wall of the hydraulic cylinder 1. During the linear displacement of the ceramic piston rod 4, the axial tension of the ceramic piston rod 4 is directly transmitted to the linkage ring 51 fixed at its top, causing the linkage ring 51 to move synchronously with the ceramic piston rod 4 at the same speed and displacement. The linkage ring 51 receives the linear displacement... The linear kinetic energy is transmitted laterally through the side extension suspension 52, causing the strip-shaped magnetic ruler 53 mounted at the end of the extension suspension 52 to perform equidistant and constant-speed linear sliding along the axis parallel to the ceramic piston rod 4. During the stage when the strip-shaped magnetic ruler 53 follows the ceramic piston rod 4 to perform linear sliding, the rod-shaped entity of the strip-shaped magnetic ruler 53 penetrates the reserved space inside the guide slide 71 from top to bottom. Since the guide slide 71 is embedded inside the limiting sleeve 61, and the movement trajectory of the guide slide 71 is rigidly physically constrained by the purely arc-shaped geometric inner wall of the arc-shaped limiting channel 64, the guide slide 71 cannot move in any linear direction along the axis of the ceramic piston rod 4. Based on this constraint relationship, when the strip-shaped magnetic ruler 53 penetrates the guide slide 71... The surface of the strip magnetic scale 53 slides purely linearly relative to the guide slide 71. As the strip magnetic scale 53 continues to slide linearly, the detection end of the reading head element 2 73, fixed inside the guide slide 71, is tightly attached to the inner surface of the strip magnetic scale 53. The sensing probe of the reading head element 2 73 continuously cuts and scans the alternating magnetic pole scale layers on the surface of the strip magnetic scale 53. The reading head element 2 73 converts the captured dynamic magnetic signal into a continuous electrical pulse signal in real time by sensing the periodic physical alternation of the magnetic field strength, and calculates the linear sliding distance of the strip magnetic scale 53 relative to the reading head element 2 73. Given that the strip magnetic scale 53 maintains rigidity with the ceramic piston rod 4 through the extension suspension 52 and the linkage ring sleeve 51, The long transmission connection allows the linear slip data to reflect the actual linear extension and retraction length of the ceramic piston rod 4 relative to the hydraulic cylinder 1 in real time and proportionally. When the ceramic piston rod 4 undergoes radial deflection and rotation displacement due to the torque force transmitted by the outer docking device, the rotational torque of the ceramic piston rod 4 is converted into rotational energy within the hydraulic cylinder 1. This rotational energy is directly transmitted from the ceramic piston rod 4 to the top linkage ring 51, driving the linkage ring 51 to rotate coaxially. The coaxial rotational torque of the linkage ring 51 is amplified by the lateral force arm of the extended suspension 52, transforming it into a circular oscillating thrust centered on the central axis of the ceramic piston rod 4. This forces the strip magnetic scale 53 to deflect by tracing an arc trajectory in space. As the strip magnetic scale 53 performs circular deflection...The side edge of the strip-shaped magnetic scale 53 directly presses against the inner wall of the guide slide 71, applying a tangential pushing force to the guide slide 71. After bearing this tangential pushing force, the guide slide 71 is guided by the trajectory of the arc-shaped limiting channel 64 and slides in a circular arc along the inner wall curvature of the arc-shaped limiting channel 64. The arc-shaped limiting channel 64 forcibly guides the guide slide 71 to make precise arc movements with the axis of the hydraulic cylinder 1 as the reference point. During the synchronous process of the guide slide 71 moving along the arc-shaped limiting channel 64, the reading magnetic head element 72 mounted on the outside of the guide slide 71 slides in a circular motion synchronously with the guide slide 71. During this sliding, the detection end of the reading magnetic head element 72 is tightly attached to the arc surface of the arc-shaped magnetic scale 65. The magnetic field lines on the surface of the arc-shaped magnetic grating ruler 65 are cut during relative motion. The pre-distributed arc magnetic pole signals on the arc-shaped magnetic grating ruler 65 are picked up, and the read magnetic pole change is converted into a phase electrical signal. The control system analyzes the specific arc length of the guide carriage 71 sliding in the arc-shaped limiting channel 64 based on the signal, and further calculates the precise radial deflection angle of the ceramic piston rod 4 in the hydraulic cylinder 1. Under the combined motion state of the ceramic piston rod 4 simultaneously performing linear extension and radial rotation, the strip magnetic grating ruler 53, while pushing the guide carriage 71 to circumferential displacement, still maintains linear shuttle sliding inside it. The reading head element 1 72 and the reading head element 2 73 independently perform magnetic pole scanning based on their independent sliding sectional surfaces, completing multi-dimensional space without interference. Synchronous acquisition of displacement data: When the hydraulic cylinder executes the retraction command, the ceramic piston rod 4 retracts into the inner cavity of the hydraulic cylinder 1. The retraction of the ceramic piston rod 4 pulls the linkage ring 51 to rapidly approach the output port of the hydraulic cylinder 1. The rearward displacement of the linkage ring 51 directly applies a longitudinal downward thrust to the top stacked clamping ring 83. Due to the rigid support reaction force provided by the stationary side frame 81 and its end sealing ring 82, under the dual compression of the thrust of the linkage ring 51 and the reaction force of the sealing ring 82, the various folded joint sections of the stacked clamping ring 83 buckle under the force. The ring sections begin to stack and shrink downwards in sequence. With the rapid folding and shrinking of the stacked clamping ring 83, the stacked clamping ring 83, the outer wall of the ceramic piston rod 4, and the sealing ring 82... The internal cavity volume of the enclosed ring structure is significantly reduced. This compression forces the normally compressed air inside to undergo intense pressure, shortening the distance between air molecules. This causes the air pressure inside the stacked ring 83 to rise exponentially, rapidly forming a high-pressure compressed airflow with kinetic energy. This high-pressure airflow seeks a pressure release channel within the stacked ring 83. The pressurized gas surges out at high speed through the connecting slot and directly enters the inner cavity of the exhaust outlet pipe 84. The exhaust outlet pipe 84 guides the high-pressure airflow in a directional manner, delivering it to the intake hopper 62 inside the limiting sleeve 61. After entering the intake hopper 62, the high-pressure airflow is subjected to secondary compression by the gradually narrowing inner wall geometry of the intake hopper 62, significantly accelerating the airflow velocity.The airflow is transformed into a high-speed jet with physical impact. This high-speed jet is ejected from the air intake hopper 62 and directly impacts the inclined surface of the guide ramp 63 opposite to the outer side of the limiting sleeve 61. The specific inward tilt angle of the guide ramp 63 generates a forced guiding effect on the high-speed airflow, changing the jet vector direction of the airflow and causing the airflow to refract upward and inward along the inclined surface, accurately focusing and covering the detection movement area where the guide slide 71 is located. The directionally refracted high-speed airflow powerfully sweeps the outer surface of the read head element 72 located in the output direction of the guide ramp 63, while the airflow penetrates the internal gap of the limiting sleeve 61. The continuous impact on the surface of the arc-shaped magnetic scale 65 and the detection interface where the reading head element 73 and the strip magnetic scale 53 are attached, causes the high-speed airflow molecules to generate kinetic energy impacts. These impacts directly affect the dust, oil, and small hard particles attached to the scale layer of the strip magnetic scale 53, the arc-shaped magnetic scale 65, and the sensing ends of the two reading head elements. The airflow forcefully overcomes the electrostatic adsorption and physical adhesion between the impurities and the surface of the detection elements, completely peeling the dust particles off the surface of the elements. The peeled dust is suspended in the turbulent flow and blown into the external environment from the open area of ​​the limiting sleeve 61, ensuring the magnetic scale is protected. The cleanliness of the magnetic pole scale on the ruler surface maintains the accuracy of signal pickup by the reading head element. When the ceramic piston rod 4 extends outward from the hydraulic cylinder 1 again to perform the extension action, the linkage ring 51 moves away from the hydraulic cylinder 1. The linkage ring 51 applies a reverse upward pulling force to the stacking ring 83, pulling each folded section of the stacking ring 83 to unfold sequentially. The internal cavity volume of the stacking ring 83 gradually expands with the unfolding action, causing the internal air pressure to drop sharply, forming a negative pressure state lower than the external atmospheric pressure. Driven by the pressure difference, the external ambient air flows in the opposite direction along the original path, passes through the air intake hopper 62, and is discharged through the exhaust pipe. Guided by the outlet pipe 84, the gas is forcibly drawn back into the inner cavity of the stacked ring sleeve 83 through the connecting slot, replenishing the total amount of gas stored inside the gas chamber. During the continuous extension and retraction cycle of the ceramic piston rod 4, the flexible covering structure formed by the stationary side frame 81, the sealing ring 82, and the stacked ring sleeve 83 always surrounds the outside of the ceramic piston rod 4. Utilizing its retractable and expandable physical properties, the stacked ring sleeve 83 closely follows the movement trajectory of the ceramic piston rod 4, adaptively adjusting its length in real time to construct a dynamic isolation barrier, continuously preventing wear particles and corrosive media from the external environment from directly contacting the exposed metal surface of the ceramic piston rod 4.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod, characterized in that, include: Hydraulic cylinder (1), used to form the cylinder structure of a hydraulic cylinder; The docking end (2) is located in the hydraulic cylinder (1) and is used to form the cylinder mounting end of the hydraulic cylinder; The output end (3) is located in the hydraulic cylinder (1) and is used to form the mounting end of the ceramic piston rod of the hydraulic cylinder; The ceramic piston rod (4) is located in the hydraulic cylinder (1) and is used to form the ceramic piston rod part of the hydraulic cylinder; The diaphragm linkage mechanism (5) is located on the ceramic piston rod (4) and is used to form a synchronous displacement structure for magnetic displacement detection; The linkage limiting mechanism (6) is located in the hydraulic cylinder (1) and works with the strip magnetic grid ruler (53) to form a limiting structure for detecting the synchronous displacement of the ceramic piston rod. The output detection mechanism (7) is located in the linkage limit mechanism (6), and works with the strip magnetic grid ruler (53), the limit sleeve (61), the guide inclined platform (63) and the arc magnetic grid ruler (65) to form a displacement detection structure for synchronous displacement; The sealed air compressor mechanism (8) is located in the hydraulic cylinder (1), and works with the linkage ring sleeve (51) and the air inlet expansion bucket (62) for synchronous protection of the ceramic piston rod and to generate an air blowing dust removal structure during contraction; The sealed air compressor mechanism (8) includes a stationary side frame (81), which is fixed to the side of the hydraulic cylinder (1) and extends to the output port of the hydraulic cylinder (1) with its top bent. A sealing collar (82) is fixed to the bent end of the stationary side frame (81) and fixed to the output port of the hydraulic cylinder (1). A stacked clamping ring (83) is fixed to the top of the stationary side frame (81) and is folded and joined in sequence. The topmost stacked clamping ring (83) is fixed to the linkage ring (51), so that the stacked clamping ring (83) completely covers the exposed surface of the ceramic piston rod (4). An exhaust outlet pipe (84) is fixed to the side wall of the sealing collar (82) facing the air intake expansion bucket (62), and a connecting slot is provided between the exhaust outlet pipe (84) and the inside of the stacked clamping ring (83).

2. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 1, characterized in that, The ceramic piston rod (4) extends into the hydraulic cylinder (1) to form a basic hydraulic cylinder structure. The diaphragm linkage mechanism (5) is mounted on the end of the ceramic piston rod (4) and moves synchronously with the ceramic piston rod (4). It is also the same length as the ceramic piston rod (4). The linkage limit mechanism (6) is mounted on one side of the end of the hydraulic cylinder (1). The output detection mechanism (7) is mounted on the linkage limit mechanism (6) and can move synchronously with the circumferential displacement of the diaphragm linkage mechanism (5). The sealing air pressure mechanism (8) is mounted on the hydraulic cylinder (1) and docks with the diaphragm linkage mechanism (5).

3. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 1, characterized in that, The diaphragm linkage mechanism (5) includes a linkage ring sleeve (51), which is fixed to the top end of the ceramic piston rod (4). An extension suspension (52) is fixed to the side of the linkage ring sleeve (51) facing the linkage limiting mechanism (6), and a strip magnetic grid ruler (53) is mounted and fixed to the end of the extension suspension (52).

4. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 1, characterized in that, The linkage limiting mechanism (6) includes a limiting sleeve (61), which is fixed on the top side of the hydraulic cylinder (1). An inclined guide platform (63) is fixed on the outer side of the limiting sleeve (61). An arc-shaped limiting channel (64) is fixed inside the limiting sleeve (61) and forms an arc-shaped guiding structure. An arc-shaped magnetic grating ruler (65) is set inside the limiting sleeve (61) and arranged in parallel with the arc-shaped limiting channel (64). The arc-shaped limiting channel (64) and the arc-shaped magnetic grating ruler (65) allow the strip magnetic grating ruler (53) to pass through and fit together.

5. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 1, characterized in that, The output detection mechanism (7) includes a guide slide (71), which is embedded in the limiting sleeve (61) and moves along the arc-shaped limiting channel (64). The guide slide (71) is sleeved on the strip magnetic grating ruler (53) and moves circumferentially following the strip magnetic grating ruler (53).

6. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 1, characterized in that, The docking end (2) is located at the end of the hydraulic cylinder (1), while the output end (3) is located in the output port direction of the hydraulic cylinder (1), and a ceramic piston rod (4) is fixed inside.

7. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 4, characterized in that, The air intake hopper (62) is fixed to the inner port of the limiting sleeve (61) to form an air outlet.

8. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 5, characterized in that, The guide slide (71) is fixed with a reading head element (72) on the outside and placed in the output direction of the guide ramp (63). The detection end of the reading head element (72) is suspended and attached to the surface of the arc-shaped magnetic grid ruler (65). The guide slide (71) is fixed with a reading head element (73) on the inside and the inspection end of the reading head element (73) is attached to the inner side of the strip magnetic grid ruler (53).

9. A hydraulic cylinder with absolute displacement detection function of ceramic piston rod according to claim 1, characterized in that, The surface of the ceramic piston rod (4) is machined with two sets of equally spaced annular grooves along the axial direction. The spacing of the first set of annular grooves is a reference value, and the spacing of the second set of annular grooves is greater than the reference value. The relative distance between the two sets of annular grooves changes cyclically along the axial direction of the ceramic piston rod (4), and the relative distance between the two sets of grooves gradually increases from the initial value and then gradually decreases back to the initial value in each cycle; The output port of the hydraulic cylinder (1) is equipped with a sensor detection unit (9), whose detection surface width is more than twice the reference value, which is used to capture the distance relationship between four adjacent grooves in order to calculate the absolute displacement position of the ceramic piston rod (4).

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