A composite lubrication structure of a guide rail and a manufacturing method thereof

Abstract

The present invention discloses a composite lubrication structure for a guide rail, comprising: laser ablation of several sine groove micro-textures and several polygon pit micro-textures on the surface of the guide rail; the sine groove micro-textures are ablated along the width direction of the guide rail, and several sine groove micro-textures are ablated at equal intervals, with wave peaks facing wave peaks and wave valleys facing wave valleys, and MoS2 is filled in the grooves of the sine groove micro-textures; the polygon pit micro-textures are ablated on the surface of the guide rail between the wave peaks of two adjacent sine groove micro-textures and between the wave valleys of two adjacent sine groove micro-textures, and MoS2 is filled in the grooves of the polygon pit micro-textures. The present invention uses a combination of sine-shaped micro-textures and polygon pit-shaped micro-textures. Compared with the smooth surface specimen, the creep time is reduced by 72%, and the average friction coefficient is decreased by 44.88%; compared with the circular micro-pit specimen, the creep time is reduced by 69.83%, and the average friction coefficient is decreased by 30.67%.

Description

Technical Field

[0001] The present invention relates to the technical field of functional surfaces, and particularly relates to a composite lubrication structure of a guide rail and a manufacturing method thereof. Background Art

[0002] As a key moving component of a machine tool, the accuracy and dynamic stability of the guide rail are the prerequisite conditions for high-precision machining. The machining workload of the guide rail accounts for about 40% of the total workload of the whole machine. Steel metal guide rails are widely used due to their good rigidity, low price, excellent load-bearing capacity, etc., but they have certain limitations such as low hardness and high friction coefficient. Under the working conditions of low speed and heavy load, creep phenomenon occurs, reducing the positioning accuracy and shortening the service life of the machine tool. With the rapid improvement of the requirements for the positioning accuracy of machine tools, especially for numerical control machine tools, it is very necessary to improve the anti-creep performance of machine tool guide rails.

[0003] Adopting the matrix surface texturing technology to machine orderly arranged micro-textures on the surface of the counter-grinding pair can effectively improve the friction characteristics of the contact surface, reduce the friction coefficient and wear rate between the friction pairs, and extend the service life of the parts. Chinese Patent (Application No. 201711406914.8) discloses a combined micro-texture guide rail and its manufacturing method, in which micro-grooves are machined between micro-pits. Although the lubrication performance is improved, the function of the texture to collect wear debris cannot be fully exerted. Chinese Patent (Application No. 202010474739.1) discloses a composite guide rail and method of micro-texture grooves and lubricating oil grooves. This method is to set lubricating oil grooves on the surface of the sliding guide rail in contact with the fixed guide rail, and a plurality of micro-texture grooves are evenly arranged between adjacent lubricating oil grooves. However, the surface density of the given micro-texture grooves is between 5% - 50%, and the distribution density between it and the lubricating oil grooves does not give an accurate value or range. Chinese Patent (Application No. 202111265776.!) discloses a micro-nano texture guide rail and method based on ultrasonic rolling and femtosecond laser processing. This method first uses ultrasonic rolling to machine micro-texture grooves, and then uses femtosecond laser to machine nano-texture grooves in the micro-texture grooves to realize the preparation of a micro-nano composite textured guide rail. However, the groove width of the machined micro-texture grooves given is 50 - 500μm, and the range is too large; and no method is given to ensure the machining accuracy of the nano-scale nano-texture grooves. Chinese Patent (Application No. 201721812052.4) discloses a concave-convex interval distributed micro-texture composite guide rail. This guide rail has micro-grooves connecting single micro-pit morphologies along the length direction of the guide rail in the micro-pit morphology array. The running stability of the machine tool can be improved by reducing the critical creep speed, but the area occupancy rate range of the given micro-texture and the oil distribution groove is relatively large, and no optimal area combination is given. Summary of the Invention

[0004] The present invention provides a composite lubrication structure for a guide rail and a manufacturing method thereof to solve the problem of crawling phenomenon that occurs in a sliding guide rail under low-speed and heavy-load conditions in the prior art.

[0005] The present invention provides a composite lubrication structure for a guide rail, including: laser ablation of several sine groove micro-textures and several polygon pit micro-textures on the surface of the guide rail;

[0006] The sine groove micro-textures are ablated along the width direction of the guide rail, and several sine groove micro-textures are ablated at equal intervals, with wave peaks opposite to wave peaks and wave valleys opposite to wave valleys. MoS2 is filled in the grooves of the sine groove micro-textures; the polygon pit micro-textures are ablated on the surface of the guide rail between the wave peaks of two adjacent sine groove micro-textures and between the wave valleys, and MoS2 is filled in the grooves of the polygon pit micro-textures.

[0007] Further, the groove width range of the sine groove micro-texture is: 0.1 mm to 0.2 mm; the spacing range between adjacent sine groove micro-textures is: 1 mm to 2 mm; the sine period range of the sine groove micro-texture is: 1 mm to 3 mm, and the diagonal length range of the polygon pit micro-texture is: 0.1 mm to 0.3 mm.

[0008] Further, the groove width of the sine groove micro-texture is: 0.15 mm; the spacing between adjacent sine groove micro-textures is: 1.5 mm; the sine period of the sine groove micro-texture is: 2 mm; the groove depth of the sine groove micro-texture is: 100 μm.

[0009] Further, the spacing between adjacent polygon pit micro-textures is: 1 mm; the spacing range between the polygon pit micro-texture and the sine groove micro-texture is: 0.33 mm; the diagonal length range of the polygon pit micro-texture is: 0.2 mm; the groove depth of the polygon pit micro-texture is: 100 μm.

[0010] Further, the polygon pit micro-texture is a regular hexagon.

[0011] The present invention also provides a manufacturing method for the composite lubrication structure of a guide rail, including the following steps:

[0012] Step 1: Polish the surface of the guide rail with 800-2000 mesh sandpaper until the roughness Ra≤0.8 μm, ultrasonically clean it with 99% anhydrous ethanol, and air-dry it naturally;

[0013] Step 2: Use a nanosecond laser to ablate sine groove micro-textures and polygon pit micro-textures on the surface of the guide rail. After ablation, remove the slag on the surface of the guide rail with 2000 mesh sandpaper, and ultrasonically clean it with 99% anhydrous ethanol;

[0014] Step 3: Mix MoS2 and 32# Morinke high-quality guideway oil to make a mixed paste, and apply it evenly in the grooves of the micro-texture;

[0015] Step 4: Use a setting machine to solidify the mixed paste in the micro-textured grooves and polish to complete the manufacturing process.

[0016] Furthermore, in step 2, the nanosecond laser is an FB50-1 nanosecond laser.

[0017] Furthermore, in step 2, the operating parameters of the nanosecond laser are: output power of 10 W, repetition frequency of 60 kHz, and ablation times of 10 times.

[0018] Furthermore, in step 3, the mixing ratio of MoS2 and 32# Morinke high-quality guide rail oil is 1:2.

[0019] Beneficial effects of the present invention:

[0020] The present invention uses a sinusoidal micro-texture and a polygonal pit-type micro-texture in combination. Compared with a smooth surface sample, the crawling time is reduced by 72% and the average friction coefficient is reduced by 44.88%; compared with a circular micro-pit sample, the crawling time is reduced by 69.83% and the average friction coefficient is reduced by 30.67%.

[0021] The polygonal dimple micro-texture of the present invention adopts a regular hexagonal pattern, which can produce a better "suction cup" effect due to elastic deformation, and at the same time produce a better "trap effect" on the surface due to high contact pressure and low sliding speed.

[0022] The manufacturing process of the present invention adopts laser processing and inlaying MoS2, which improves the efficiency and reduces the cost.

[0023] The manufacturing process of the present invention generates little processing heat, and the guide rail has no risk of thermal deformation.

[0024] The manufacturing process of the present invention adopts non-contact processing and does not generate mechanical extrusion or mechanical stress on the material.

[0025] The present invention adopts a mixing ratio of 1:2 of MoS2 and 32# Morinke high-quality guide rail oil as the optimal quality ratio, which not only ensures the viscosity of the lubricant, but also ensures the effect of applying the mixed oil on the guide rail surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0027] Figure 1 A three-dimensional view of a specific embodiment of the present invention;

[0028] Figure 2 The front view of the specific embodiment of the present invention;

[0029] Figure 3 The schematic diagram of the manufacturing process in the specific embodiment of the present invention;

[0030] Figure 4 The change curve of the crawling time of different micro-textured specimens;

[0031] Figure 5 The change curve of the average friction coefficient of different micro-textured specimens. Specific embodiments

[0032] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0033] As Figure 1 、 2 shown, the embodiments of the present invention provide a composite lubrication structure for a guide rail, including: laser ablation of several sinusoidal groove micro-textures 1 and several regular hexagon pit micro-textures 2 on the surface of the guide rail 3;

[0034] The sinusoidal groove micro-texture 1 is ablated along the width direction of the guide rail 3, the array direction of the sinusoidal groove micro-texture 1 is perpendicular to the movement direction of the guide rail 3, several sinusoidal groove micro-textures 1 are ablated at equal intervals, the wave peaks are opposite to each other, and the wave valleys are opposite to each other. MoS2 is filled in the grooves of the sinusoidal groove micro-texture 1; the regular hexagon pit micro-texture 2 is ablated on the surface of the guide rail 3 between the wave peaks and between the wave valleys of two adjacent sinusoidal groove micro-textures 1, and MoS2 is filled in the grooves of the regular hexagon pit micro-texture 2.

[0035] The groove width b of the sinusoidal groove micro-texture 1 ranges from 0.1 mm to 0.2 mm; the spacing c between adjacent sinusoidal groove micro-textures 1 ranges from 1 mm to 2 mm; the sinusoidal period e of the sinusoidal groove micro-texture 1 ranges from 1 mm to 3 mm.

[0036] The spacing t x between adjacent regular hexagon pit micro-textures 2 y and the spacing t y between the regular hexagon pit micro-texture 2 and the sinusoidal groove micro-texture 1 change with the change of the sinusoidal groove micro-texture 1, and it is only necessary to ensure that the regular hexagons are arranged horizontally in the middle of the sinusoidal grooves; the diagonal length d of the regular hexagon pit micro-texture 2 ranges from 0.1 mm to 0.3 mm.

[0037] As Figure 3 shown, the present invention also provides a manufacturing method for a composite lubrication structure of a guide rail, including the following steps:

[0038] Step 1: Polish the surface of the guide rail with 800 - 2000 - mesh sandpaper until the roughness Ra ≤ 0.8μm, ultrasonically clean it with 99% anhydrous ethanol for 5 minutes, and air - dry it naturally;

[0039] Step 2: Use an FB50 - 1 nanosecond laser: with a repeatability accuracy ≤ 10urad, a laser wavelength of 1064nm, an engraving line speed ≤ 7000mm / s, a repetition frequency of 20 - 80KHz, a power adjustment range of 10 - 100%, and a maximum output power of 50W. Ablate sinusoidal groove micro - textures and regular - hexagon pit micro - textures on the surface of the guide rail. The operating parameters of the nanosecond laser are: output power of 10W, repetition frequency of 60kHz, ablation times of 10 times. After ablation, remove the slag on the surface of the guide rail with 2000 - mesh sandpaper, and ultrasonically clean it with 99% anhydrous ethanol for 15 minutes;

[0040] Step 3: Mix MoS2 with 32# Morunke high - quality guide rail oil to form a mixed paste. The mixing ratio of MoS2 to 32# Morunke high - quality guide rail oil is 1:2, and evenly apply it on the surface of the guide rail;

[0041] The MoS2 embedded in the composite micro - texture can, during the reciprocating friction process and under a large load, the stress concentration effect promotes the precipitation of MoS2 in the micro - texture onto the surface of the wear track, and diffuses to the upper and lower specimen surfaces and the lubricating oil. Since MoS2 has a strong adsorption effect on the metal surface, a solid lubricating transfer film is formed at the friction interface;[[ID=1']]

[0042] Too much guide rail oil (too little MoS2) cannot ensure the viscosity of the solid lubricant, which easily leads to the rapid loss of the solid lubricant during the friction process, and thus cannot continuously maintain the lubrication and anti - wear effect at the friction interface; too little guide rail oil (too much MoS2) can enhance the viscosity to prevent rapid loss during the friction process, but at the same time, it also causes the paste to be viscous, the mixing of MoS2 and the guide rail oil is insufficient, affecting the surface coating, and thus affecting the embedding effect.

[0043] Step 4: Use an XQ - 2B embedding machine: rated voltage of 220V, rated power of 650W, temperature adjustment range of 100 - 180°C, cure the mixed paste in the micro - texture grooves, keep it at 100°C for 10 minutes after pressurization. After standing and cooling, use 2000 - mesh sandpaper to remove the surface hard lumps, and then complete the manufacturing process.

[0044] The following are the comparative data of the friction test under low - speed and heavy - load conditions for specific embodiments of the present invention, as follows:

[0045] The lower specimen SS is: a guide rail with a smooth surface;

[0046] The lower specimen SR is: a guide rail with only polygonal pit micro-texture (not filled with MoS2) on the surface;

[0047] The lower specimen SN is: a guide rail with only sinusoidal groove micro-texture (not filled with MoS2) on the surface;

[0048] The lower specimen SF is: a guide rail with only sinusoidal groove micro-texture (filled with MoS2) on the surface;

[0049] The lower specimen SP is: a guide rail with only sinusoidal groove micro-texture (filled with MoS2 at intervals) on the surface;

[0050] The lower specimen SF-1 is: a guide rail with polygonal pit micro-texture and sinusoidal groove micro-texture (not filled with MoS2) on the surface;

[0051] The lower specimen SF-2 is: a guide rail with polygonal pit micro-texture (not filled with MoS2) and sinusoidal groove micro-texture (filled with MoS2) on the surface;

[0052] The lower specimen SF-3 has a guide rail with the structure of the present invention: the groove width of the sinusoidal groove micro-texture is: 0.15 mm; the spacing between adjacent sinusoidal groove micro-textures is: 1.5 mm; the length of one period of the sinusoidal texture is: 2 mm; the groove depth of the sinusoidal groove micro-texture is: 100 μm, the spacing between adjacent regular hexagonal pit micro-textures is: 1 mm; the spacing between the regular hexagonal pit micro-texture and the sinusoidal groove micro-texture is: 0.34 mm; the diagonal length of the regular hexagonal pit micro-texture is: 0.2 mm; the groove depth of the regular hexagonal pit micro-texture is: 100 μm.

[0053] The upper specimen is: a cylindrical pin with a diameter of 6 mm, a length of 15 mm, and a material of 45# steel for friction tests under low-speed and heavy-load conditions.

[0054] The experimental process is as follows: the equivalent condition of low-speed and heavy-load for reciprocating friction tests: the load is 30 N, the stroke is 6 mm, the reciprocating frequency is 1 Hz, and the time is 30 min. The friction contact method is pin-slider reciprocating friction, and the ambient temperature is 20°C. The lubricating oil is 32# Morunke high-quality guide rail oil, which is filled in the oil pool to exceed the specimen surface by 3 mm. Each group of tests is repeated 3 times, and the average value of the 3 test data is taken.

[0055] As Figure 4 shown, the creep time of the lower specimen SS is the longest, and its creep time is about 125 s; the creep time of the lower specimen SF-3 is the shortest, and its creep time is about 35 s. The lower specimen SF-3 has decreased by 72% compared with the lower specimen SS; and has decreased by 69.83% compared with the lower specimen SR.

[0056] As Figure 5As shown, the lower specimen SS has the largest friction coefficient, with an average friction coefficient of 0.205; the lower specimen SF-3 has the smallest friction coefficient, with an average friction coefficient of 0.113. The lower specimen SF-3 has decreased by 44.88% compared to the lower specimen SS; and has decreased by 30.67% compared to the lower specimen SR.

[0057] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A composite lubrication structure for a guide rail, characterized in that, Including: Laser ablating several sine groove micro-textures and several polygon pit micro-textures on the surface of the guide rail; The sine groove micro-textures are ablated along the width direction of the guide rail. Several sine groove micro-textures are ablated at equal intervals, with wave peaks opposite to wave peaks and wave valleys opposite to wave valleys. The grooves of the sine groove micro-textures are filled with a paste. The polygon pit micro-textures are ablated on the surface of the guide rail between the wave peaks and between the wave valleys of two adjacent sine groove micro-textures. The grooves of the polygon pit micro-textures are filled with a paste. Among them, the paste is a mixture of MoS2 and 32# guide rail oil, and the mixing ratio of MoS2 to 32# guide rail oil is 1:2; The groove width range of the sine groove micro-textures is: 0.1 mm to 0.2 mm; the spacing range between adjacent sine groove micro-textures is: 1 mm to 2 mm; the sine period range of the sine groove micro-textures is: 1 mm to 3 mm, and the diagonal length range of the polygon pit micro-textures is: 0.1 mm to 0.3 mm; the groove depth of the sine groove micro-textures is: 100 μm; the spacing between the polygon pit micro-textures and the sine groove micro-textures is: 0.33 mm; the groove depth of the polygon pit micro-textures is: 100 μm.

2. The composite lubrication structure of the guide rail according to claim 1, characterized in that, The polygon pit micro-textures are regular hexagons.

3. A manufacturing method of a composite lubrication structure for a guide rail, applicable to the composite lubrication structure of the guide rail as described in any one of claims 1 or 2, characterized in that, The manufacturing method of the composite lubrication structure of the guide rail includes the following steps: Step 1: Polish the surface of the guide rail with 800 - 2000 mesh sandpaper until the roughness Ra ≤ 0.8 μm, ultrasonically clean it with 99% anhydrous ethanol, and air-dry it naturally; Step 2: Use a nanosecond laser to ablate sine groove micro-textures and polygon pit micro-textures on the surface of the guide rail. After ablation, remove the slag on the surface of the guide rail with 2000 mesh sandpaper, and ultrasonically clean it with 99% anhydrous ethanol; Step 3: Mix MoS2 and 32# guide rail oil to make a mixed paste, and evenly apply it in the grooves of the sine groove micro-textures and polygon pit micro-textures; Step 4: Use an embedding machine to cure the mixed paste in the micro-texture grooves, and complete the manufacturing process after grinding.

4. The manufacturing method of the composite lubrication structure of the guide rail according to claim 3, characterized in that In the above Step 2, the nanosecond laser is an FB50 - 1 nanosecond laser.

5. The manufacturing method of the composite lubrication structure of the guide rail according to claim 3 or 4, characterized in that, In the above Step 2, the working parameters of the nanosecond laser are: output power is 10 W, repetition frequency is 60 kHz, and ablation times are 10 times.

6. The manufacturing method of the composite lubrication structure of the guide rail according to claim 3, characterized in that In the above Step 4, the embedding machine is an XQ - 2B embedding machine.

Images