Simple tool for online polishing of lathe outer circle and its using method

Abstract

A simple fixture for online polishing of the outer diameter of a lathe and its method of use are disclosed. The fixture includes a sleeve body, a piston slidably integrated into the sleeve body, a screw driving the piston axially, a support frame hinged to the front end of the piston via a pin, and a buffer plate and a polishing layer stacked sequentially from the inside out at the front end of the support frame, which are detachably clamped and fixed by a pressure plate and screws. The sleeve body has set screws on its sidewalls, the inner ends of which extend into the guide groove of the piston for limiting and preventing rotation. This invention utilizes screw thread transmission to achieve fine adjustment of polishing pressure, and utilizes the free swing of the support frame around the pin to achieve adaptive floating fit to the outer diameter contour. Combined with the elastic buffer plate absorbing vibration, online grinding and polishing can be achieved under lathe turret mounting. The fixture has a simple structure, low manufacturing cost, and convenient operation, and is suitable for polishing the outer diameter of shaft parts of different diameters, effectively improving processing efficiency and surface quality consistency.

Description

Technical Field

[0001] This invention relates to the field of surface treatment technology in machining, specifically to a simple tooling and method for online polishing of the outer diameter of a lathe, which is particularly suitable for the precision grinding and subsequent polishing of the outer diameter of the piston rod in the moving components of marine diesel engines. Background Technology

[0002] The piston rod is one of the core components of the moving parts of a marine diesel engine. Its outer diameter typically works in conjunction with seals, guide sleeves, and cylinder liners. Under high temperature, high pressure, and reciprocating motion conditions, extremely stringent requirements are placed on the dimensional accuracy, cylindricity, surface roughness, and control of microscopic defects of the outer diameter. Currently, the typical machining process for piston rods is: rough turning → semi-finish turning → finish turning → rough grinding → finish grinding. After precision grinding, the surface roughness of the outer diameter can generally reach Ra 0.2~0.4 μm. However, the grinding process often leaves grinding burn layers, micro-grinding scratches, vibration marks, or metal burrs on the surface. These microscopic defects directly affect the sealing performance and service life of the piston rod. Therefore, after precision grinding, a fine polishing process is usually added to eliminate grinding marks, reduce the surface roughness to below Ra 0.1 μm, and improve the residual compressive stress state of the surface.

[0003] However, for a long time, this polishing process has mainly relied on the following two methods: one is manual polishing, in which the operator holds sandpaper or felt and uses polishing paste to manually polish the surface while the piston rod is rotating. This method is not only labor-intensive and inefficient, but also makes it difficult to control the polishing force and feed speed evenly, which can easily cause local over-polishing or under-polishing of the outer circle, resulting in out-of-tolerance cylindricity. At the same time, manual operation is highly dependent on the operator's skills and has poor quality consistency. The second method is to unload the workpiece from the lathe and transfer it to a dedicated polishing machine or abrasive flow equipment for processing. This method increases the number of workpiece clamping and transfers, which not only prolongs the production cycle, but also makes it easy for secondary clamping to introduce positioning errors, affecting the positional accuracy of the outer circle and other coaxial features.

[0004] Furthermore, while existing lathes possess spindle rotation and turret feed capabilities, the market lacks a simple, low-cost, and directly mountable online polishing attachment. Existing lathe polishing devices often employ complex hydraulic or pneumatic floating mechanisms, resulting in high manufacturing costs or applicability only to specific diameter ranges, hindering rapid adoption in workshops. Therefore, there is an urgent need for a simple tooling that fully utilizes the existing motion capabilities of the lathe, offers convenient assembly and disassembly, provides adjustable polishing pressure, and allows for quick replacement of polishing elements. This would enable online polishing of the piston rod's outer diameter after grinding in a single setup on the machine tool, thereby improving machining efficiency, ensuring surface quality stability, and increasing part yield. Summary of the Invention

[0005] To overcome the shortcomings of existing piston rod polishing methods, which rely on manual polishing or offline dedicated equipment after precision grinding, resulting in low efficiency, poor quality consistency, large secondary clamping errors, and high dependence on operator skills, this invention provides a simple tooling for online polishing of piston rod outer diameters on a lathe and its usage method. This tooling has a compact structure, and its components can be self-made or purchased as standard parts. It can be directly installed on the lathe turret, utilizing the rotation of the lathe spindle and the feed motion of the turret to achieve online fine grinding and polishing of the piston rod in a single clamping operation. It is also widely applicable to the surface finishing of shaft parts of different diameters.

[0006] The objective of this invention is achieved by adopting the following technical solution: A simple tooling for online polishing of the outer diameter of a lathe includes a screw, a sleeve, a plug, a set screw, a pin, a cotter pin, a support frame, a buffer plate, a polishing layer, screws, and a pressure plate.

[0007] Sleeve body: This sleeve body serves as the supporting base for the entire tooling. Its rear end has a mounting shank (such as a rectangular or cylindrical shank) for fixed connection with the lathe turret clamping part. Its dimensions are adapted to the tool holder clamping groove of the lathe turret, ensuring the tooling can be firmly fixed by the turret's clamping mechanism. A guide hole is axially extended through the sleeve body to accommodate and provide sliding guidance for subsequent components.

[0008] Piston: This piston is slidably installed in the guide hole of the sleeve body with a clearance fit (preferably H7 / f6 or H7 / g6 clearance fit), which allows it to slide freely along the axial direction of the sleeve body while ensuring smooth movement and guiding accuracy. The rear end of the piston has an internally threaded hole along the axial direction for cooperating with the screw to transmit driving force; the front end of the piston extends to the outside of the front end face of the sleeve body for connecting the support frame; the outer surface of the side wall of the piston has a guide groove recessed along the axial direction.

[0009] Set screw: This set screw passes radially and is threaded to the side wall of the sleeve body. Its inner end extends into the guide groove of the piston and forms a sliding fit with the guide groove. This structure restricts the circumferential rotation of the piston relative to the sleeve body, ensuring that the piston only moves axially in a linear motion and does not rotate, thus guaranteeing the accuracy of the pressure application direction. On the other hand, the front and rear ends of the guide groove form a first stop and a second stop, respectively. When the piston slides to the front or rear limit position, the inner end of the set screw abuts against the corresponding stop, forming a mechanical limiting structure for the axial sliding of the piston and preventing the piston from slipping out of the sleeve body. Preferably, a gap of 0.5mm to 1mm is left between the inner end face of the set screw and the bottom surface of the guide groove to avoid excessive sliding friction resistance.

[0010] Screw: This screw is a drive and pressure regulating element. Its rear end has a screw-operating part (such as a hexagonal head or knurled handle) located outside the rear end face of the sleeve body, allowing for manual rotation by the operator. The front end of the screw passes through the rear end face of the sleeve body and has an external thread, which engages with the internal threaded hole at the rear end of the plug. By rotating the screw, the plug is driven axially forward or backward within the sleeve body using the thread transmission principle, thereby precisely adjusting the contact pressure between the polished layer and the outer diameter of the workpiece. Preferably, the external thread section at the front end of the screw has a stepped thread structure, including a complete thread section in the middle, a front reducing section at the front end, and a rear reducing section at the rear end. When the plug moves to the front limit position, the front reducing section screws into the internal threaded hole of the plug and idles. When the plug moves to the rear limit position, the rear reducing section disengages from the internal threaded hole of the plug, thus achieving bidirectional overload protection and preventing the operator from damaging the threads or jamming the tool due to excessive rotation.

[0011] Support Frame: This support frame is the load-bearing component of the polishing actuator. The rear end of the support frame is hinged to the front end of the shaft plug via a pin. A cotter pin passes through the end of the pin to prevent axial disengagement. Specifically, the rear end of the support frame has a pair of spaced-apart, parallel ear plates forming a U-shaped mounting groove. The front end of the shaft plug has a flat hinge joint that fits into the U-shaped mounting groove. Both ear plates and the flat hinge joint have coaxial through holes through which the pin passes. The front end of the support frame has a flat bearing surface for mounting the buffer plate and polishing layer. Through this hinged structure, the support frame can freely swing circumferentially around the pin's axis during polishing, adaptively following the cylindricity error and installation eccentricity of the workpiece's outer diameter, maintaining uniform line contact between the polishing layer and the workpiece's outer surface, effectively avoiding localized over-polishing or intermittent contact problems caused by rigid tooling.

[0012] Buffer plate: This buffer plate is made of elastic material (such as rubber sheet, polyurethane sheet or spring steel sheet), and its back is attached to the bearing surface of the support frame. The buffer plate generates elastic deformation when the polishing pressure fluctuates, so as to absorb the high-frequency vibration during the polishing process and buffer the instantaneous pressure impact, making the contact between the polished layer and the outer circle of the workpiece more gentle and stable, avoiding surface scratches or vibration marks caused by rigid contact.

[0013] Polishing layer: This polishing layer is a consumable functional layer that directly contacts the outer diameter of the workpiece for grinding and polishing. Its back side is attached to the front side of the buffer plate, and its front side is used to directly contact the outer diameter of the workpiece. The polishing layer can be selected from any of the following materials, such as felt, fine sandpaper, polishing cloth, or non-woven fabric containing abrasive, depending on the different surface roughness states of the outer diameter of the workpiece after precision grinding, so as to achieve flexible switching from coarse polishing to fine polishing.

[0014] Pressure plate and screws: The pressure plate is pressed onto the front side of the polishing layer. Multiple screws pass through corresponding through holes on the pressure plate, polishing layer, and buffer plate, and then connect to the internally threaded holes on the support frame's bearing surface. This stacks the buffer plate and polishing layer sequentially from the inside out and detachably presses them firmly onto the support frame's bearing surface. Preferably, the pressure plate has multiple countersunk screw holes evenly distributed circumferentially, and each screw is a hexagonal head screw. The buffer plate and polishing layer are evenly pressed together by diagonally alternating tightening. This detachable connection structure allows for quick replacement when the polishing layer wears down or when different polishing tools need to be changed.

[0015] This invention also provides a method for online polishing of the outer diameter of a lathe using the aforementioned simple tooling, comprising the following steps: Step S1: Select a polishing layer with the appropriate material and grit according to the surface condition of the workpiece after precision grinding of the outer circle. Attach the back of the buffer plate to the bearing surface of the support frame, attach the back of the polishing layer to the front of the buffer plate, cover with the pressure plate, and screw the screws through the pressure plate, polishing layer and buffer plate into the internal threaded hole of the support frame to press and fix the three together.

[0016] Step S2: Insert the mounting shank at the rear end of the sleeve into the tool holder of the lathe turret, and operate the turret clamping mechanism to fix the sleeve, so that the entire fixture has radial (X-axis) and axial (Z-axis) feed capabilities along with the turret.

[0017] Step S3: Adjust the radial position of the lathe turret so that the front side of the polishing layer is 3mm to 5mm away from the outer surface of the workpiece. At the same time, rotate the screw so that the complete thread section of its stepped thread engages with the internal thread hole of the shaft plug at the middle stroke position. This ensures that the screw has sufficient advance margin to compensate for the wear of the polishing layer and sufficient retraction space during the subsequent polishing process.

[0018] Step S4: Start the lathe spindle to rotate the workpiece at a set speed (preferably, the workpiece outer diameter linear speed is 30m / min to 80m / min). Manually rotate the screw's turning mechanism. Through the threaded engagement between the screw and the piston, the piston slides forward within the sleeve. The piston pushes the support frame, buffer plate, and polishing layer together towards the workpiece until the polishing layer's front surface contacts the rotating workpiece's outer diameter. Continue to fine-tune the screw to the set polishing pressure in small increments (e.g., 1 / 8 to 1 / 4 turn each time). At this time, the support frame automatically swings under the action of the pin hinge to adapt to the outer diameter contour, and the buffer plate simultaneously undergoes a small elastic deformation to absorb vibration. Then, operate the turret to perform a uniform feed motion along the workpiece axis (preferably, the feed speed is 0.1mm / r to 0.5mm / r) to grind and polish the entire outer diameter of the workpiece. During the polishing process, the operable turret can reciprocate along the workpiece axis. The number of reciprocating polishing cycles is preferably 2 to 4. During each reciprocating polishing cycle, the contact pressure between the polishing layer and the outer circle of the workpiece is gradually reduced by micro-rotating the screw, forming a polishing process that progresses from coarse polishing to fine polishing, ultimately obtaining a high-quality surface finish.

[0019] Step S5: After polishing is completed, rotate the screw in the opposite direction, and drive the shaft plug to slide backward in the sleeve body, so that the support frame drives the polished layer to move backward and separate from the outer circle of the workpiece. Stop the spindle rotation and remove the workpiece.

[0020] When processing workpieces of different diameters, the radial position of the polishing layer can be adjusted by replacing the polishing layer or buffer plate of different thicknesses, so that it is always within the effective working range of the screw stroke, without the need to replace the main tooling body, thus achieving good versatility.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: A hinged joint consisting of a pin and a cotter pin is used between the front end of the piston rod and the rear end of the support frame, allowing the support frame to swing freely around the pin axis in the circumferential direction. This floating structure ensures that even with minor roundness errors or installation eccentricities during piston rod rotation, the polished layer automatically follows the outer circumference contour and maintains a uniform line contact state. This effectively solves the problem of local over-polishing or intermittent contact caused by rigid tooling's inability to conform to the shape, significantly improving the stability and reliability of polishing quality.

[0022] This invention uses a pressure plate and screws to detachably press and fix the polishing layer to the front end of the support frame. The operator can flexibly select polishing tools of different materials and grits, such as felt, fine sandpaper, and polishing cloth, according to the different surface roughness states after the outer circle of the piston rod is ground. This allows for quick replacement and significantly expands the applicability of a single tooling. It also enables progressive operations of rough polishing, semi-fine polishing, and fine polishing on the same tooling.

[0023] This invention employs a screw and a threaded shaft plug to drive the polishing layer forward and backward. Utilizing the self-locking characteristics and high transmission ratio of the threaded drive, the operator can manually achieve continuous and precise adjustment of the polishing pressure, which remains stable after adjustment and will not loosen due to vibration. The combination of the set screw and guide groove provides limiting and guiding action, ensuring that the shaft plug only performs axial linear movement without rotation, guaranteeing the accuracy and controllability of the pressure application direction. Furthermore, the stepped thread structure of the screw forms a reduced-diameter idle section at both ends of the stroke, achieving bidirectional overload protection and preventing damage to the tooling due to misoperation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the simplified tooling for online polishing of the outer diameter of a lathe according to the present invention; In the diagram: 1. Screw; 2. Sleeve body; 3. Shaft plug; 4. Set screw; 5. Pin; 6. Cotter pin; 7. Support frame; 8. Buffer plate; 9. Polished layer; 10. Screw; 11. Pressure plate. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, 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.

[0026] Taking the grinding and polishing of the outer diameter of the piston rod in a marine diesel engine fuel injection assembly as an example, the present invention will be described in detail below: See Figure 1 This invention provides a simple tooling for online polishing of the outer diameter of a lathe, comprising a screw 1, a sleeve body 2, a shaft plug 3, a set screw 4, a pin 5, a cotter pin 6, a support frame 7, a buffer plate 8, a polishing layer 9, a screw 10, and a pressure plate 11. The sleeve body 2 serves as the base, with its rear end used for connection and fixation to the lathe turret. The screw 1 is screwed into the rear end of the sleeve body 2 and threadedly engages with the internal shaft plug 3. Rotating the screw drives the shaft plug 3 to move axially back and forth within the sleeve body. The front end of the shaft plug 3 is hinged to the support frame 7 via the pin 5 and the cotter pin 6, allowing the support frame to swing freely around the pin. The front end of the support frame 7 is sequentially stacked with the buffer plate 8 and the polishing layer 9, and is pressed and fixed by the pressure plate 11 and the screw 10. The set screw 4 is radially positioned on the side wall of the sleeve body, with its tail extending into the guide groove of the shaft plug 3, serving as a limit and preventing rotation.

[0027] Follow these steps to install the tooling of the present invention onto the lathe and adjust it to the state to be processed.

[0028] Step 1: Selection and installation of polishing layer 9 The operator first visually inspects the surface roughness of the piston rod's outer diameter after precision grinding, checking for any obvious grinding burns or scratches. If deep grinding textures are present (visible as uniform, fine lines), P800 fine sandpaper is selected as the polishing layer 9. If the surface is close to a mirror finish and only requires the removal of the surface oxide layer or minor burrs, industrial felt is selected with a small amount of kerosene or polishing fluid added as a lubricant. The selected polishing layer 9 is cut into a rectangle the same size as the front bearing portion of the support frame 7, neatly stacked with the buffer plate 8, and then pressed and fixed using the pressure plate 11 and screws 10. When tightening the screws 10, a diagonal alternating tightening method is used, gradually increasing the force in 2-3 stages to ensure that the pressure of the pressure plate 11 on the polishing layer 9 is evenly distributed, preventing local wrinkles.

[0029] Step 2: Insert sleeve 2 into the lathe turret. Select the appropriate tool holder or collet based on the type of lathe turret (e.g., turret type, rotary type, or VDI turret). Insert the rear end of the sleeve body 2 into the mounting groove of the tool holder, and adjust the axial extension length of the sleeve body 2 so that the middle position of the polishing layer 9 is roughly aligned with the axial center area of ​​the outer circle of the piston rod to be polished. Tighten the turret clamping screws with a torque wrench to the specified torque (generally 80~120 N·m, depending on the turret model) to ensure that the tooling does not loosen or shift during machining.

[0030] Step 3: Assembly and initial positioning of the remaining parts of the tooling Insert the shaft plug 3 into the central through hole of the sleeve body 2 from the front end, so that the front end of the shaft plug 3 extends out of the front end face of the sleeve body 2. Screw the set screw 4 into the threaded hole on the side wall of the sleeve body 2, so that its tail extends into the guide groove of the shaft plug 3, but it does not need to be fully tightened. It is advisable that the shaft plug 3 can be pushed by hand without obvious jamming. Screw the screw 1 into the rear end of the sleeve body 2, so that the thread at the front end of the screw 1 begins to engage with the internal threaded hole at the rear end of the shaft plug 3. Manually tighten until the stepped thread of the screw 1 is in the middle position, that is, the effective engagement length of the thread section of the screw 1 is about 40% to 60% of the total thread length. This ensures that the screw 1 can both advance the polishing layer 9 to compensate for wear during the subsequent polishing process and has enough room to retreat.

[0031] Align the U-shaped groove at the rear end of the support frame 7 with the flat head of the shaft plug 3, insert the pin 5, and install cotter pins 6 at both ends of the pin 5 to prevent axial movement.

[0032] Step 4: Precise adjustment of radial position Manually move the lathe turret along the X-axis (radial) towards the piston rod, gradually bringing the surface of the polished layer 9 closer to the outer circle of the piston rod. While moving the turret, observe the clearance using a feeler gauge or visual inspection until the clearance between the surface of the polished layer 9 and the outer circle of the piston rod is controlled within the range of 3-5 mm. The rationale for this clearance value is to ensure that the polished layer 9 can quickly contact the workpiece by rotating the screw 1, without wasting the screw 1's stroke due to excessive clearance, and to avoid collisions with the workpiece during rapid turret feed.

[0033] Once the tooling is installed and the initial positioning is complete, proceed with the formal polishing operation according to the following procedure.

[0034] Operation Procedure 1: Start the spindle and make initial contact Start the lathe spindle and set the spindle speed to the linear velocity range of the piston rod's outer diameter. Depending on the piston rod diameter (typically Φ100~Φ300mm) and surface condition, a linear velocity of 30~80m / min is preferred, corresponding to a spindle speed of 40~250r / min. If using sandpaper for polishing, the linear velocity should be lower (30~50m / min) to reduce grinding heat; if using felt for polishing, the linear velocity can be higher (50~80m / min). Turn on the lathe coolant or air-assisted cooling (if available) to remove polishing debris and reduce frictional heat.

[0035] Operation Procedure 2: Apply polishing pressure by rotating screw 1 With the spindle rotating, the operator holds a wrench or directly rotates the hexagonal head or knurled handle of screw 1 slowly and evenly clockwise. Screw 1 drives the piston 3 to move axially forward (towards the workpiece) along the sleeve body 2 through thread engagement. The piston 3 pushes the support frame 7, buffer plate 8, and polishing layer 9 forward as a whole until the surface of the polishing layer 9 lightly contacts the outer circle of the rotating piston rod. At this time, the operator will hear a uniform friction sound and feel a slight increase in the rotational resistance of screw 1.

[0036] Continue rotating screw 1 in small increments of 1 / 8 to 1 / 4 turn each time (approximately equivalent to 0.1 to 0.3 mm of axial feed), gradually increasing the polishing pressure. During this process, the operator should carefully observe the friction state and sound changes between the polishing layer 9 and the workpiece, as well as the generation of polishing sparks or debris. When the friction sound generated by the contact between the polishing layer 9 and the outer circle is continuous and uniform, debris is continuously discharged, and the surface gloss gradually increases, it indicates that the polishing pressure has reached the appropriate state. The generally recommended initial contact pressure (axial thrust generated by the screw 1 thread drive) is controlled within the range of 20 to 50 N, which can be adjusted appropriately according to the piston rod diameter and sandpaper grit. The principle is "light contact, uniform pressure, and avoid instantaneous heavy pressure".

[0037] Operation Procedure 3: Axial Feed Polishing Once the polishing pressure is adjusted, start the lathe turret's Z-axis (axial) automatic or manual feed, moving the turret axially along the piston rod. The polishing band gradually covers the rod from one end to the other. The axial feed speed is selected according to the polishing requirements, generally 0.1~0.5 mm / r (feed per revolution). Lower speeds are used for polishing with coarser sandpaper to ensure sufficient material removal, while higher speeds are used for fine polishing with felt to improve efficiency. During the turret movement, the operator should continuously monitor the contact state of the polishing layer 9 and make minor adjustments to the screw 1 as needed based on feedback—for example, when moving to the middle of the rod, the contact pressure may change due to workpiece cylindricity errors. In this case, the screw 1 can be finely adjusted to maintain a constant frictional resistance.

[0038] Operation Procedure Four: Reversal Polishing and Finishing For high-precision polishing, a reciprocating polishing method is typically used: after the turret moves from one end of the shaft to the other, it is not immediately retracted, but instead moved in the opposite direction along the Z-axis, allowing the polishing layer 9 to perform a second polishing on the outer circle of the shaft. The number of reciprocations is generally 2 to 4 times, and the polishing pressure can be appropriately reduced each time according to the improvement of surface gloss (achieved by slightly rotating the screw 1 in the opposite direction), forming a progressive polishing process of "rough polishing → semi-fine polishing → fine polishing", ultimately achieving the design requirement of Ra≤0.1μm.

[0039] Operation Step 5: Finishing Polishing and Retracting the Tool After polishing, first stop the lathe spindle rotation (or first reverse the screw 1 to detach the polished layer 9 from the workpiece before stopping the spindle, depending on operating habits, but for safety reasons, it is recommended to retract the tool before stopping the spindle). Reverse the screw 1 about 3-5 turns to retract the piston plug 3 about 3-8mm, completely disengaging the polished layer 9 from the outer circle of the piston rod. Then, operate the turret to retract radially along the X-axis to a safe position (at least 20mm away from the outer circle of the workpiece). Turn off the lathe spindle and coolant, and remove the piston rod to inspect the surface quality.

[0040] When the polishing layer 9 is worn down to less than 1 / 3 of its initial thickness, or when there is obvious abrasive shedding, blackening, burning, or a significant decrease in polishing effect, it needs to be replaced. The replacement procedure is as follows: Use an Allen wrench to loosen and remove the screws 10 one by one, remove the pressure plate 11, peel the worn polishing layer 9 from the buffer plate 8, and clean the residual abrasive debris from the surface of the buffer plate 8. Stack the newly cut polishing layer 9 in its original position, replace the pressure plate 11, and tighten it with the screws 10 in an alternating diagonal manner. After replacement, because the thickness of the new polishing layer 9 is increased, the initial gap and polishing pressure need to be readjusted according to the above steps.

[0041] This tooling has excellent versatility. When the piston rod diameter changes (for example, from Φ120mm to Φ200mm), there is no need to replace the main tooling; only the following simple adjustments are required: If the diameter change is small (≤±30mm), it can be compensated by adjusting the initial radial position of the turret and the stroke of screw 1.

[0042] If the diameter changes significantly (≥±50mm), the buffer plate 8 or the polishing layer 9 can be replaced with a different thickness to ensure that the surface of the polishing layer is always within the effective working range of the screw 1's stroke. If necessary, shims can be added to the front end of the support frame 7 to adjust the overall thickness. The shim thickness is calculated as "(new diameter - original diameter) / 2".

[0043] If the polishing length of the piston rod changes significantly, simply select a support frame 7 and polishing layer 9 with the corresponding width dimensions; core components such as the sleeve body 2 and the shaft plug 3 remain interchangeable.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simple tooling for online polishing of the outer diameter of a lathe, characterized in that, include: The sleeve body (2) has a mounting shank at its rear end for fixed connection with the lathe tool turret clamping part, and the sleeve body (2) has a guide through hole through it along the axial direction; A shaft plug (3) is slidably installed in the guide through hole of the sleeve body (2) in a clearance fit manner. The rear end of the shaft plug (3) is provided with an internal thread hole along the axial direction. The front end of the shaft plug (3) extends to the outside of the front end face of the sleeve body (2), and the outer surface of the side wall of the shaft plug (3) is provided with a guide groove along the axial direction. Set screw (4) is radially threaded and connected to the side wall of the sleeve body (2). The inner end of the set screw (4) extends into the guide groove of the piston (3) and slides in the guide groove to restrict the circumferential rotation of the piston (3) relative to the sleeve body (2) and limit the axial sliding stroke of the piston (3). The screw (1) has a screwing operation part at its rear end, and its front end passes through the rear end face of the sleeve body (2) and has an external thread. The external thread engages with the internal thread hole at the rear end of the shaft plug (3). By rotating the screw (1), the shaft plug (3) is driven to move forward or backward axially within the sleeve body (2). Pin (5) and cotter pin (6); The support frame (7) has its rear end hinged to the front end of the shaft plug (3) via the pin (5). The cotter pin (6) passes through the end of the pin (5) to achieve axial anti-disengagement and limiting. The front end of the support frame (7) has a flat bearing surface. The buffer plate (8) is made of elastic material and its back is attached to the bearing surface of the support frame (7); The back of the polishing layer (9) is attached to the front of the buffer plate (8), and the front of the polishing layer (9) is used to directly contact the outer circle of the workpiece for grinding and polishing. A pressure plate (11) is pressed onto the front side of the polished layer (9); and Multiple screws (10) pass through the corresponding through holes on the pressure plate (11), polishing layer (9) and buffer plate (8) respectively, and are threaded to the internal threaded holes opened on the bearing surface of the support frame (7), so that the buffer plate (8) and polishing layer (9) are stacked from the inside to the outside and detachably pressed and fixed on the bearing surface of the support frame (7).

2. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The rear end of the support frame (7) is connected to the front end of the shaft plug (3) via the pin (5), so that the support frame (7) can swing freely around the axis of the pin (5) in the circumferential direction during the polishing operation, so as to adaptively follow the cylindricity error and installation eccentricity of the outer circle of the workpiece, and maintain uniform line contact between the polishing layer (9) and the outer circle surface of the workpiece.

3. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The polishing layer (9) is any one of felt, fine sandpaper, polishing cloth or abrasive nonwoven fabric that can be detached and replaced by the pressure plate (11) and screws (10), so as to quickly change the corresponding polishing tool according to the different surface roughness states after the outer circle of the workpiece is precision ground.

4. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The buffer plate (8) is any one of rubber plate, polyurethane plate or spring steel sheet. The buffer plate (8) generates elastic deformation when the polishing pressure fluctuates, so as to absorb the high frequency vibration during the polishing process and buffer the instantaneous pressure impact.

5. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The inner end of the set screw (4) extends into the guide groove of the shaft plug (3), and there is a gap of 0.5mm to 1mm between the inner end face of the set screw (4) and the bottom surface of the guide groove. The front end and the rear end of the guide groove form a first stop and a second stop, respectively. When the shaft plug (3) slides to the front end limit or the rear end limit position, the inner end of the set screw (4) abuts against the first stop or the second stop, forming a mechanical limiting structure for the axial sliding of the shaft plug (3).

6. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The external thread section at the front end of the screw (1) is a stepped thread structure. The stepped thread includes a complete thread section in the middle, a front reducing section at the front end, and a rear reducing section at the rear end. When the piston (3) moves to the front limit position, the front reducing section is screwed into the internal thread hole of the piston (3) and forms free rotation. When the piston (3) moves to the rear limit position, the rear reducing section disengages from the internal thread hole of the piston (3) to achieve bidirectional overload protection.

7. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The mounting shank at the rear end of the sleeve body (2) is a rectangular shank or a cylindrical shank, and its external dimensions are adapted to the tool holder clamping groove of the lathe turret. The guide through hole of the sleeve body (2) and the outer circle of the shaft plug (3) are in clearance fit of H7 / f6 or H7 / g6.

8. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The pressure plate (11) has multiple countersunk holes evenly distributed along the circumference. Each screw (10) is an internal hexagonal head screw. The bearing surface of the support frame (7) has corresponding internal thread blind holes. Each screw (10) passes through the corresponding countersunk hole, the polishing layer (9) and the through hole on the buffer plate (8) and is screwed into the internal thread blind hole. The buffer plate (8) and the polishing layer (9) are evenly pressed by diagonal alternating tightening.

9. The simple tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The rear end of the support frame (7) is provided with a pair of ear plates that are spaced apart and parallel to each other, and a U-shaped mounting groove is formed between the two ear plates. The front end of the shaft plug (3) is provided with a flat hinge joint that fits the U-shaped mounting groove. Both ear plates and the flat hinge joint are provided with coaxial through holes, and the pin (5) passes through the coaxial through hole.

10. The simplified tooling for online polishing of the outer diameter of a lathe according to claim 1, characterized in that, The screw (1) has a hexagonal head or knurled handle at the rear end. This screw is located outside the rear end face of the sleeve (2) and is operated manually by the operator to finely adjust the polishing pressure.

11. A method for online polishing of the outer diameter of a lathe using the simple tooling described in any one of claims 1 to 10, characterized in that, Includes the following steps: Step S1: Select the polishing layer (9) with the corresponding material and grit according to the surface condition of the workpiece after precision grinding. Place the back of the buffer plate (8) on the bearing surface of the support frame (7), place the back of the polishing layer (9) on the front of the buffer plate (8), cover with the pressure plate (11), and screw (10) through the pressure plate (11), polishing layer (9) and buffer plate (8) and screw it into the internal thread hole of the support frame (7) to press and fix the three together. Step S2: Install the mounting shank at the rear end of the sleeve body (2) into the tool holder of the lathe tool turret, operate the tool turret clamping mechanism to fix the sleeve body (2), so that the tooling as a whole has radial and axial feed capabilities with the tool turret. Step S3: Adjust the radial position of the lathe turret so that the front surface of the polished layer (9) is 3mm to 5mm away from the outer circle surface of the workpiece. At the same time, rotate the screw (1) so that the complete thread section of its stepped thread engages with the internal thread hole of the shaft plug (3) in the middle stroke position. Step S4: Start the lathe spindle to make the workpiece rotate at the set speed. Manually rotate the screw (1) and the screw (3) screw screw (3) screw screw (1) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (3) screw screw (7) screw screw (7) screw screw (8) screw screw (8) screw screw (9) screw screw (9) screw screw (7) screw screw (8) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (1) screw screw (1) screw screw (2) screw screw (3) screw screw (2) screw screw (3) screw screw (2) screw screw (3) screw screw (2) screw screw (3) screw screw (2) screw screw (3) screw screw (4) screw screw (5) screw screw (6) screw screw (7) screw screw (8) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (9) screw screw (1) screw screw (2) screw screw (1) screw screw (2) screw screw (3 ... Step S5: After polishing is completed, rotate the screw (1) in the opposite direction and drive the shaft plug (3) to slide backward in the sleeve body (2), so that the support frame (7) drives the polishing layer (9) to move backward and separate from the outer circle of the workpiece, stop the spindle rotation and remove the workpiece.

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