Automobile shock absorber piston rod integrated with self-lubricating noise elimination structure

Abstract

The invention discloses an automobile shock absorber piston rod integrated with a self-lubricating noise reduction structure, a spiral microgroove is machined in the outer circumferential surface of the piston rod, a pumping angle is formed between the spiral direction of the spiral microgroove and the descending direction of the piston rod, and the depth of the groove is gradually shallower from the axial middle to the two ends; a porous bronze sintered layer covers the outer surface of the piston rod, and the thickness is smaller than the depth of the spiral microgroove; an annular oil collecting groove is formed in the wall face of an inner hole of the guide sleeve and periodically communicates with the spiral microgroove in the movement process. When the piston rod moves downwards, the spiral microgroove pumps oil liquid to a guide sleeve matching area, the annular oil collecting groove collects temporarily-stored oil liquid, and the porous bronze sintering layer adsorbs the stored oil liquid; during ascending, the two cooperate to release oil to a matching surface, and a full-stroke lubricating oil film is maintained.

Description

Technical Field

[0001] This invention relates to the field of automotive shock absorber technology, and more specifically, to an automotive shock absorber piston rod with an integrated self-lubricating noise reduction structure. Background Technology

[0002] In an automotive shock absorber, the piston rod reciprocates axially within the cylinder. The piston rod passes through a guide sleeve and an oil seal fixed to the end of the cylinder. The guide sleeve provides radial support and axial guidance, while the oil seal prevents the shock absorber fluid from leaking outwards.

[0003] In the prior art, the piston rod relies on the natural adhesion of damping oil inside the cylinder to the outer surface of the rod body to lubricate the mating surface between the guide sleeve and the piston rod.

[0004] However, when the piston rod moves upward, the oil seal scrapes off the oil adhering to the outer surface of the piston rod, resulting in a state of insufficient oil on the surface of the piston rod when it moves downward, leading to insufficient lubrication of the guide sleeve and piston rod mating surfaces, and producing dry friction noise. This problem is particularly prominent during cold starts or the first operation after a long period of inactivity. Summary of the Invention

[0005] This invention provides a spiral microgroove oil storage self-circulating piston rod, which solves the technical problems in related technologies where the oil seal scrapes off the oil on the outer surface of the piston rod when the piston rod moves upward, resulting in the piston rod surface being in a state of oil deficiency when it moves downward and enters the guide sleeve area, causing insufficient lubrication of the mating surface between the guide sleeve and the piston rod and generating dry friction noise.

[0006] This invention discloses a spiral microgroove oil-storing self-circulating piston rod for automotive shock absorbers. It includes a piston rod, a guide sleeve, and an oil seal. The piston rod passes through a cylinder and reciprocates linearly along the cylinder's axial direction. The guide sleeve is fixedly connected to the inner hole of the cylinder's open end. The oil seal is fixedly connected to the cylinder's open end and located outside the guide sleeve along the piston rod's extension direction. The outer circumferential surface of the piston rod is provided with spiral microgrooves extending along a spiral line. The spiral direction of the microgrooves is configured to direct the oil in the grooves towards the guide sleeve when the piston rod moves downwards. The pumping drive force is directed by a spiral microgroove. The groove depth gradually decreases from the axial middle of the piston rod towards both ends, while the groove width remains constant along the spiral stroke. The outer surface of the piston rod is covered with a porous bronze sintered layer, which is sintered and fixed to the outer surface of the piston rod's base metal and covers the ridge surface between adjacent spiral microgrooves. The thickness of the porous bronze sintered layer is less than the groove depth of the spiral microgrooves. The inner wall of the guide sleeve has an annular oil collecting groove extending circumferentially. When the piston rod reciprocates, the spiral microgrooves and the annular oil collecting groove are periodically connected.

[0007] Furthermore, a piston is fixedly connected to the end of the piston rod away from the extended end. The outer circumferential surface of the piston forms a sealed sliding fit with the inner wall of the cylinder, dividing the inner cavity of the cylinder into two oil chambers. The damping oil fills the inner cavity of the cylinder and the fitting gap between the piston rod and the guide sleeve.

[0008] Furthermore, the spiral microgroove is a single-headed spiral groove that extends continuously along the outer circumference of the piston rod at a constant spiral angle, forming a single uninterrupted spiral channel.

[0009] Furthermore, the spiral microgroove is a multi-head spiral groove, with multiple spiral microgrooves evenly distributed circumferentially along the outer circumference of the piston rod, and the spiral direction and spiral helix angle of each spiral microgroove are the same.

[0010] Furthermore, the groove depth of the spiral microgroove changes linearly along the axial direction, decreasing at a constant slope from the middle of the piston rod to both ends.

[0011] Furthermore, the groove depth of the spiral microgroove exhibits a non-linear gradual change along the axial direction. The groove depth changes gently in the section near the middle of the piston rod's axial direction, while the change intensifies in the section near both ends of the piston rod.

[0012] Furthermore, the cross-section of the spiral microgroove is arc-shaped, with a smooth arc transition between the groove wall and the groove bottom, and rounded corners between the two sides of the groove opening and the ridge surface of the outer circumference of the piston rod.

[0013] Furthermore, the cross-section of the spiral microgroove is rectangular, the groove wall and the groove bottom intersect at right angles, and there is a chamfer transition between the two sides of the groove opening and the ridge surface of the outer circumference of the piston rod.

[0014] Furthermore, the groove edge of the spiral microgroove is provided with a smooth transition surface, which smoothly connects the groove wall and the ridge surface of the outer circumference of the piston rod.

[0015] Furthermore, the annular oil collecting groove consists of multiple annular grooves spaced apart along the axial direction of the inner hole of the guide sleeve. The cross-section of the annular oil collecting groove is an arc shape that opens radially toward the piston rod. The opening width of the arc-shaped cross-section at the inner hole wall of the guide sleeve is greater than the groove width of the spiral micro-groove.

[0016] This invention solves the technical problem of insufficient lubrication and dry friction noise caused by oil seal scraping at the guide sleeve mating surface during piston rod descent by setting a spiral microgroove with a pumping angle on the outer circumferential surface of the piston rod, covering the outer surface of the piston rod with a porous bronze sintered layer, and opening an annular oil collecting groove on the inner wall of the guide sleeve. The invention achieves the following technical effects: During piston rod descent, the spiral microgroove actively pumps oil to the guide sleeve mating area, overcoming the oil-deficient state during the lower stroke; the gradually changing groove depth of the spiral microgroove causes the oil to be subjected to increasing compression at the end of pumping, improving the filling efficiency of the mating gap; the porous bronze sintered layer continuously supplies oil to the mating surface through capillary oil release during the upward phase, maintaining the continuity of the lubricating oil film in the reciprocating cycle; the annular oil collecting groove collects and temporarily stores the pumped oil, ensuring that the oil supply is not interrupted by the switching of the piston rod's movement direction; the three elements work together to maintain the lubricating oil film covering the guide sleeve and piston rod mating surface throughout the entire reciprocating stroke of the piston rod. Attached Figure Description

[0017] Figure 1 This is a front view of the spiral microgroove oil storage self-circulation piston rod of the present invention; Figure 2 This is a longitudinal sectional view of the spiral microgroove oil storage self-circulating piston rod of the present invention; Figure 3 This is a cross-sectional view of the spiral microgroove oil storage self-circulating piston rod of the present invention in the guide sleeve area; Figure 4 This is an isometric view of the piston rod surface features of the spiral microgroove oil storage self-circulating piston rod of the present invention.

[0018] In the diagram: Cylinder-1, Piston rod-2, Guide sleeve-3, Oil seal-4, Annular oil collection groove-5, Spiral microgroove-6, Porous bronze sintered layer-7, Piston-8. Detailed Implementation

[0019] The technical problem to be solved by this embodiment In an automotive shock absorber, piston rod 2 reciprocates axially within cylinder 1, generating damping force through the interaction of piston 8 and damping fluid. Piston rod 2 passes through guide sleeve 3 and oil seal 4, both fixed to the end of cylinder 1. Guide sleeve 3 provides radial support and axial guidance, while oil seal 4 prevents fluid leakage. When piston rod 2 moves upward, oil seal 4 scrapes away the fluid adhering to its outer surface. When piston rod 2 moves downward, the surface of the rod is de-lubricated due to the scraped fluid, entering the guide sleeve 3 area. This results in insufficient lubrication of the mating surfaces between guide sleeve 3 and piston rod 2, causing dry friction noise. This problem is particularly pronounced during cold starts or the first operation after a long period of inactivity, as the residual oil film on the piston rod 2 surface is extremely thin or even completely absent at this time.

[0020] Product Structure of This Embodiment This embodiment provides a spiral microgroove 6 oil-storing self-circulating piston rod 2, which is used in an automotive shock absorber. The spiral microgroove 6 on the outer surface of the piston rod 2 generates a pumping action as the piston rod 2 descends, delivering oil to the guide sleeve 3 area. Simultaneously, the porous bronze sintered layer 7 on the outer surface of the piston rod 2 continuously adsorbs and releases oil, ensuring that the mating surface between the guide sleeve 3 and the piston rod 2 always maintains a sufficient oil film. The spiral microgroove 6 oil-storing self-circulating piston rod 2 includes at least a piston rod 2, a guide sleeve 3, and an oil seal 4. The piston rod 2 passes through a cylinder 1 and reciprocates linearly along the axis of the cylinder 1. The guide sleeve 3 is fixedly connected to the inner hole of the open end of the cylinder 1, and the oil seal 4 is fixedly connected to the open end of the cylinder 1 and located outside the guide sleeve 3 along the extension direction of the piston rod 2.

[0021] The outer circumferential surface of the piston rod 2 is machined with continuous spiral microgrooves 6 along the axial direction. The spiral microgrooves 6 extend spirally along the outer circumferential surface of the piston rod 2. The spiral direction of the spiral microgrooves 6 forms a pumping angle with the direction of movement of the piston rod 2 relative to the cylinder 1 when the piston rod 2 moves downward. That is, when the piston rod 2 moves away from the extended end, the spiral direction of the spiral microgrooves 6 causes the oil in the groove to be driven by a component force in the direction towards the extended end, thereby pumping the oil in the direction towards the guide sleeve 3. The groove depth of the spiral microgrooves 6 gradually decreases from the axial middle of the piston rod 2 to both ends of the piston rod 2, while the groove width remains constant throughout the entire spiral stroke. It should be understood that the groove depth is the largest at the axial middle, making the oil storage volume and pumping capacity strongest in this area; as the groove depth gradually decreases towards both ends, the oil is squeezed during pumping due to the gradually decreasing cross-sectional area of ​​the groove cavity, and is thus pushed into the fitting gap between the guide sleeve 3 and the piston rod 2.

[0022] The outer surface of the piston rod 2 is covered with a porous bronze sintered layer 7, which is sintered and fixed to the outer surface of the base metal of the piston rod 2. The thickness of the porous bronze sintered layer 7 is less than the groove depth of the spiral microgroove 6, so that the bottom of the spiral microgroove 6 is exposed to the base metal of the piston rod 2. It should be understood that the porous bronze sintered layer 7 covers the ridge surface between adjacent spiral microgrooves 6, that is, the surface of the boss between each adjacent spiral microgroove 6 is covered with the porous bronze sintered layer 7, while the groove cavity of the spiral microgroove 6, because the groove depth is greater than the thickness of the porous bronze sintered layer 7, the groove bottom area remains the base metal surface, thus ensuring that the spiral microgroove 6 has a complete groove cavity cross section for oil flow and pumping. The porous bronze sintered layer 7 has a large number of interconnected micropores, which can adsorb and store damping oil through capillary action; when the pressure of the mating surface changes during the movement of the piston rod 2, the oil stored in the porous bronze sintered layer 7 is squeezed out and released to the mating surface, maintaining the lubricating oil film.

[0023] An annular oil collecting groove 5 is formed on the inner wall of the guide sleeve 3. The annular oil collecting groove 5 is an annular groove extending circumferentially along the inner hole of the guide sleeve 3 and is formed within the inner wall of the guide sleeve 3. When the piston rod 2 passes through the guide sleeve 3 and reciprocates axially, the spiral microgroove 6 moves synchronously with the piston rod 2. The spiral microgroove 6 and the annular oil collecting groove 5 are periodically connected during the movement: when a section of the spiral microgroove 6 moves to a position radially aligned with the annular oil collecting groove 5, a fluid passage is formed between the groove cavity of the spiral microgroove 6 and the groove cavity of the annular oil collecting groove 5, and the oil pumped to this position enters the annular oil collecting groove 5 for temporary storage; when the piston rod 2 continues to move and causes that section of the spiral microgroove 6 to leave the axial position of the annular oil collecting groove 5, the porous bronze sintered layer 7 on the ridge surface of the piston rod 2 blocks the fluid passage. The annular oil collecting groove 5 collects and temporarily stores the pumped oil, forming a local oil-rich area in the fit gap between the guide sleeve 3 and the piston rod 2, continuously supplying oil to the mating surface.

[0024] The piston 8 is fixedly connected to the end of the piston rod 2 away from the extended end. The outer circumferential surface of the piston 8 forms a sealed sliding fit with the inner wall of the cylinder 1, dividing the inner cavity of the cylinder 1 into two oil chambers. The damping oil fills the inner cavity of the cylinder 1 and the fitting clearance between the piston rod 2 and the guide sleeve 3.

[0025] In some embodiments, the spiral microgroove 6 is a single-headed spiral groove that extends continuously along the outer circumference of the piston rod 2 at a constant spiral angle, forming a single uninterrupted spiral channel.

[0026] In some embodiments, the spiral microgroove 6 is a multi-head spiral groove, with multiple spiral microgrooves 6 evenly distributed circumferentially along the outer circumference of the piston rod 2. The spiral direction and spiral helix angle of each spiral microgroove 6 are the same. It should be noted that the number of times the multi-head spiral groove connects with the annular oil collecting groove 5 in each stroke cycle of the piston rod 2 increases with the increase of the number of spiral heads, and the total flow rate of oil pumped per unit stroke increases accordingly.

[0027] In some embodiments, the cross-section of the spiral microgroove 6 is arc-shaped, with a smooth arc transition between the groove wall and the groove bottom, and a rounded transition between the two sides of the groove opening and the ridge surface of the outer circumference of the piston rod 2.

[0028] In some embodiments, the cross-section of the spiral microgroove 6 is rectangular, the groove wall and the groove bottom intersect at right angles, and a chamfer transition is provided between the two sides of the groove opening and the ridge surface of the outer circumference of the piston rod 2.

[0029] In some embodiments, the groove depth of the spiral microgroove 6 is linearly gradual along the axial direction, that is, the groove depth decreases at a constant slope from the middle of the piston rod 2 to both ends.

[0030] In some embodiments, the groove depth of the spiral microgroove 6 is non-linearly gradual along the axial direction. The groove depth changes gently in the section near the middle of the piston rod 2 and changes more intensely in the section near both ends of the piston rod 2. This causes the oil to be subjected to a sharp increase in the extrusion pressure when it approaches the mating area of ​​the guide sleeve 3, thereby enhancing the filling of the mating gap by the oil.

[0031] In some embodiments, the annular oil collecting groove 5 is a single annular groove, which is opened at the axial center position of the inner wall of the guide sleeve 3.

[0032] In some embodiments, the annular oil collecting groove 5 consists of multiple annular grooves spaced apart along the axial direction of the inner hole of the guide sleeve 3. It should be noted that the multiple annular oil collecting grooves 5 increase the total volume of oil collection and temporary storage, allowing a larger oil-rich area to be formed on the mating surface of the guide sleeve 3 along the axial direction, thereby improving the axial coverage uniformity of the lubricating oil film.

[0033] Furthermore, in order to reduce the stress concentration at the groove edge of the spiral microgroove 6 when it slides in contact with the mating surface of the guide sleeve 3, the groove edge of the spiral microgroove 6 is provided with a smooth transition surface. The smooth transition surface smoothly connects the groove wall and the ridge surface of the outer circumference of the piston rod 2, thereby reducing the resistance of oil flowing in and out at the groove opening, and at the same time reducing the wear of the spiral microgroove 6 edge on the inner wall of the guide sleeve 3.

[0034] Furthermore, in order to improve the collection efficiency of pumped oil in the annular oil collecting groove 5, the cross-section of the annular oil collecting groove 5 is an arc shape with a radial opening towards the piston rod 2. The opening width of the arc-shaped cross-section at the inner wall of the guide sleeve 3 is greater than the groove width of the spiral micro groove 6, so that when the spiral micro groove 6 moves to the position of axial alignment with the annular oil collecting groove 5, the communication area between the two increases, and the oil flows more easily from the spiral micro groove 6 into the annular oil collecting groove 5.

[0035] Execution steps When the shock absorber is working, the piston rod 2 reciprocates linearly along the axial direction inside the cylinder 1, and the piston 8 moves synchronously with the piston rod 2 and throttles the damping oil through the damping hole to generate damping force.

[0036] As piston rod 2 moves downwards, it moves away from the extended end, and the spiral microgroove 6 moves synchronously with it. Because the spiral direction of the spiral microgroove 6 forms a pumping angle with the downward direction of piston rod 2, the groove wall of the spiral microgroove 6 generates a pushing force on the oil within the groove in the direction towards the extended end, driving the oil to flow along the spiral microgroove 6 towards the guide sleeve 3 area. During the flow, as the groove depth of the spiral microgroove 6 gradually decreases from the axial middle of piston rod 2 towards the extended end, the cross-sectional area of ​​the groove cavity gradually decreases, and the oil is gradually pushed into the mating gap between the guide sleeve 3 and piston rod 2 under increasing pressure.

[0037] As the piston rod 2 descends, each segment of the spiral microgroove 6 passes sequentially through the axial position of the annular oil collecting groove 5. Whenever a segment of the spiral microgroove 6 aligns radially with the annular oil collecting groove 5, a fluid passage is formed between the groove cavity of the spiral microgroove 6 and the groove cavity of the annular oil collecting groove 5. The oil pumped to this location enters the annular oil collecting groove 5 through this fluid passage for temporary storage. As the piston rod 2 continues to descend, this segment of the spiral microgroove 6 disengages from the axial position of the annular oil collecting groove 5, and the porous bronze sintered layer 7 on the ridge surface of the piston rod 2 moves to the corresponding radial position of the annular oil collecting groove 5, thus interrupting the fluid passage. This process of connection and interruption alternates periodically with the movement of the piston rod 2, allowing the annular oil collecting groove 5 to continuously collect the pumped oil, forming a locally oil-rich area on the mating surface of the guide sleeve 3.

[0038] Meanwhile, when the porous bronze sintered layer 7 on the ridge surface of the piston rod 2 passes through the oil-rich area, it adsorbs the oil through the capillary action of the porous structure and stores the oil in the interconnected micropores inside the porous bronze sintered layer 7.

[0039] As piston rod 2 moves upward, it extends in the direction of extension. Oil seal 4 scrapes away excess oil adhering to the outer surface of piston rod 2 to prevent leakage. At this time, the outer surface of the rod is in a state of oil deficiency after being scraped by oil seal 4. However, the oil temporarily stored in the annular oil collection groove 5 is continuously supplied to the mating surface through the fitting gap between guide sleeve 3 and piston rod 2. In addition, during the upward movement of piston rod 2, the radial support force distribution of guide sleeve 3 on piston rod 2 changes. Under the action of pressure change at the mating surface, the oil stored in the porous bronze sintered layer 7 is released from the micropores to the mating surface, reforming a lubricating oil film on the outer surface of piston rod 2.

[0040] It should be understood that during each reciprocating cycle of the piston rod 2, in the downward phase, the spiral microgroove 6 continuously pumps oil to the guide sleeve 3 area, the annular oil collecting groove 5 collects and temporarily stores the pumped oil, and the porous bronze sintered layer 7 simultaneously adsorbs and stores the oil; in the upward phase, the annular oil collecting groove 5 releases the temporarily stored oil into the mating gap, and the porous bronze sintered layer 7 releases the stored oil under pressure changes. This forms a self-circulating supply of oil in the mating area of ​​the guide sleeve 3, ensuring that the mating surface between the guide sleeve 3 and the piston rod 2 remains covered with an oil film throughout the entire motion cycle.

[0041] In some embodiments, when the spiral microgroove 6 is a multi-head spiral groove, each spiral microgroove 6 connects to the annular oil collecting groove 5 in sequence for every pitch distance the piston rod 2 moves downward. Within the same motion cycle, the frequency of oil receiving by the annular oil collecting groove 5 increases with the number of spiral heads, and the oil replenishment is more uniform and continuous.

[0042] In some embodiments, when the annular oil collecting groove 5 is a plurality of annular grooves spaced apart along the axial direction, the spiral microgroove 6 communicates with the plurality of annular oil collecting grooves 5 simultaneously or sequentially during the downward movement of the piston rod 2. Each annular oil collecting groove 5 collects oil at its respective axial position, so that the mating surface of the guide sleeve 3 forms a plurality of segmented oil-rich areas along the axial direction. Each segmented oil-rich area together maintains the continuity of the oil film over the entire length of the mating surface.

[0043] Technical effects of this embodiment In this embodiment, a spiral microgroove 6 is provided on the outer circumferential surface of the piston rod 2. The spiral direction of the spiral microgroove 6 forms a pumping angle with the downward direction of the piston rod 2. Therefore, when the piston rod 2 moves downward, the groove wall of the spiral microgroove 6 generates a pushing force on the oil in the direction toward the guide sleeve 3, actively transporting the oil to the mating area between the guide sleeve 3 and the piston rod 2, thus overcoming the oil-deficient state in the lower stroke caused by the scraping of the oil seal 4 on the surface of the piston rod 2.

[0044] The depth of the spiral microgroove 6 gradually decreases from the middle of the piston rod 2 towards both ends. Therefore, the oil is subjected to increasing extrusion pressure during pumping due to the gradual reduction of the cross-sectional area of ​​the groove cavity, which prompts the oil to fill the mating gap between the guide sleeve 3 and the piston rod 2 more effectively, thereby improving the filling efficiency of the pumped oil on the mating surface.

[0045] The porous bronze sintered layer 7 covering the outer surface of the piston rod 2 adsorbs and stores oil through the capillary action of its porous structure. During the stroke of the piston rod 2, when the pressure at the mating surface changes, the stored oil is released. Therefore, even during the upward movement of the spiral microgroove 6 when it does not pump, oil can still be supplied to the mating surface, maintaining the continuity of the lubricating oil film throughout the entire reciprocating cycle. Simultaneously, the thickness of the porous bronze sintered layer 7 is less than the groove depth of the spiral microgroove 6, and the bottom of the spiral microgroove 6 is exposed above the base metal. Therefore, the presence of the porous bronze sintered layer 7 does not reduce the effective groove cross-section of the spiral microgroove 6, ensuring that the pumping function and the oil storage function do not interfere with each other.

[0046] The annular oil collecting groove 5 and the spiral micro-groove 6 on the inner wall of the guide sleeve 3 are periodically connected during movement, collecting and temporarily storing pumped oil to form a local oil-rich area. Therefore, a stable oil reserve is maintained on the mating surface of the guide sleeve 3, so that the oil supply is not interrupted due to the instantaneous change of the piston rod 2's movement direction.

[0047] It is evident that the pumping action of the spiral microgroove 6, the storage and release action of the porous bronze sintered layer 7, and the collection and temporary storage action of the annular oil collecting groove 5 work together to maintain a sufficient lubricating oil film on the mating surface between the guide sleeve 3 and the piston rod 2 throughout the entire stroke of the piston rod 2 reciprocating motion. This eliminates the dry friction noise between the guide sleeve 3 and the piston rod 2 under the condition of insufficient oil, and in particular improves the lubrication conditions of the mating area of ​​the guide sleeve 3 during low-temperature start-up and the first operation after a long period of static storage.

[0048] The embodiments of the present invention have been described above. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make more equivalent embodiments under the guidance of the present embodiments, and all of them are within the protection scope of the present embodiments.

Claims

1. A spiral microgroove oil-storing self-circulating piston rod for use in automotive shock absorbers, characterized in that, include: The piston rod (2) passes through the cylinder (1) and reciprocates linearly along the cylinder axis. A guide sleeve (3) is fixedly connected to the inner hole of the cylinder opening end; an oil seal (4) is fixedly connected to the cylinder opening end and located outside the guide sleeve along the piston rod extension direction; a spiral microgroove (6) extending along the spiral line is provided on the outer circumferential surface of the piston rod, and the spiral direction of the spiral microgroove is set to generate a pumping driving force towards the guide sleeve for the oil in the groove when the piston rod moves downward, the groove depth of the spiral microgroove gradually becomes shallower from the axial middle of the piston rod to both ends, and the groove width remains constant along the spiral stroke; a porous bronze sintered layer (7) is provided on the outer surface of the piston rod, the porous bronze sintered layer is sintered and fixed to the outer surface of the piston rod base metal and covers the ridge surface between adjacent spiral microgrooves, and the thickness of the porous bronze sintered layer is less than the groove depth of the spiral microgroove; an annular oil collecting groove (5) extending along the circumferential direction is opened on the inner wall of the guide sleeve, and the spiral microgroove and the annular oil collecting groove are periodically connected when the piston rod reciprocates.

2. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, A piston (8) is fixedly connected to the end of the piston rod away from the protruding end. The outer circumferential surface of the piston forms a sealed sliding fit with the inner wall of the cylinder, dividing the inner cavity of the cylinder into two oil chambers. The damping oil fills the inner cavity of the cylinder and the fitting gap between the piston rod and the guide sleeve.

3. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The spiral microgroove is a single-headed spiral groove that extends continuously along the outer circumference of the piston rod at a constant spiral angle, forming a single uninterrupted spiral channel.

4. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The spiral microgroove is a multi-head spiral groove, with multiple spiral microgrooves evenly distributed along the outer circumference of the piston rod. The spiral direction and spiral helix angle of each spiral microgroove are the same.

5. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The groove depth of the spiral microgroove changes linearly along the axial direction, decreasing at a constant slope from the middle of the piston rod to both ends.

6. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The groove depth of the spiral microgroove exhibits a non-linear gradual change along the axial direction. The groove depth changes gently in the section near the middle of the piston rod's axial direction, while the change intensifies in the section near both ends of the piston rod.

7. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The cross-section of the spiral microgroove is arc-shaped, with a smooth arc transition between the groove wall and the groove bottom, and rounded corners between the two sides of the groove opening and the ridge surface of the outer circumference of the piston rod.

8. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The cross-section of the spiral microgroove is rectangular, with the groove wall and the groove bottom intersecting at right angles. The two sides of the groove opening are chamfered to transition between the groove opening and the ridge surface of the outer circumference of the piston rod.

9. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The groove edge of the spiral microgroove has a smooth transition surface, which smoothly connects the groove wall and the ridge surface of the outer circumference of the piston rod.

10. The spiral microgroove oil storage self-circulating piston rod according to claim 1, characterized in that, The annular oil collecting groove consists of multiple annular grooves spaced apart along the axial direction of the inner hole of the guide sleeve. The cross-section of the annular oil collecting groove is an arc shape that opens radially toward the piston rod. The opening width of the arc-shaped cross-section at the inner hole wall of the guide sleeve is greater than the groove width of the spiral micro-groove.

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