JP4512831B2 - Sliding linear motion guide device - Google Patents

Description

  The present invention relates to a sliding linear motion guide device that reciprocally slides, and is used as a guide device for a machine tool used for cutting difficult-to-cut materials such as dies.

  One method of reducing the sliding friction coefficient of the sliding linear guide is to scrape the sliding surface of the sliding guide. The original purpose of scraping is to ensure the parallelism and flatness of the sliding surface. However, the recess of about 5 μm to 10 μm provided on the sliding surface by this scraping is Non-Patent Document 1 describes that an oil groove (oil reservoir) acts during sliding to improve lubricity.

  Much of the linear motion guide scraping used for machine tools is done by hand-finishing by skilled workers. Against this background, paying attention to the oil groove action of the scrape provided on the sliding surface, there are many conventional methods for reducing the sliding friction coefficient of the sliding linear guide by providing a fine recess on the sliding surface. Although publicly available, it cannot be said that these conventional techniques exhibit a sufficient scavenging effect.

  In the methods disclosed in Patent Document 1, Patent Document 2, and Patent Document 3, a fine recess is provided in one or both of the sliding surfaces, and a lubricant is held in the recess to improve the lubricity between the sliding surfaces. It is a way to improve. For example, Patent Document 3 discloses an optimum arrangement of fine grooves provided on a sliding surface of a sliding member of an engine crankshaft or camshaft by providing fine grooves of 0.5 μm to 20 μm. With respect to this sliding guide, the effect of forming fine grooves on the sliding surface has been clarified from the sliding test result in the oil bath lubrication of the cylindrical shaft and the bearing metal.

  However, in an open-type sliding linear guide with a parallel sliding surface, such as a sliding linear guide of a machine tool, there is a side leakage of lubricating oil. It is very different from the oil bath lubrication type bearings that are supplied abundantly. In addition, in the slide guide having the sliding surfaces between the cylindrical surfaces, a dynamic pressure is generated in the lubricating oil between the sliding surfaces due to the wedge effect in a part of the sliding surfaces, and the effect of preventing the metal contact between the sliding surfaces is achieved. I can expect. However, such an effect cannot be expected with the sliding guide of the machine tool. For these reasons, even if the above method is applied to the sliding surface of the machine tool as it is, it can be said that it is difficult to reduce the sliding friction coefficient of the sliding linear motion guide of the machine tool.

  In addition, in Patent Document 4, for the purpose of efficiently diffusing the lubricating oil to the sliding surface for the sliding linear guide of the machine tool, a recess is provided on one of the sliding surfaces, and the recesses are A sliding surface characterized by having grooves connected by oil grooves is disclosed. In sliding guides with sliding surfaces between cylindrical surfaces, dynamic pressure is generated in the lubricating oil between the sliding surfaces, and a lubricating oil flow is easily generated between the sliding surfaces. Such a lubricating oil flow hardly occurs with a few machine tool slide linear motion guides, and the retention of the lubricating oil film is poor. As described in Patent Document 4, the recesses provided on the sliding surfaces are connected to each other to facilitate the flow of the lubricating oil between the sliding surfaces, thereby diffusing the lubricating oil over a wide area of the sliding surface. Therefore, it is considered effective. From the surface roughness measurement results of the scraped surface by the inventors, it was confirmed that the recesses by scraping do not form a single recess but large recesses are connected to each other.

On the other hand, to reduce the sliding friction coefficient, it is effective to prevent metal contact between the sliding surfaces. For example, in order to prevent this metal contact in the static pressure guide, lubricating oil to which static pressure is applied is supplied from the outside, but in order to secure a sufficient fluid lubricating oil film thickness, the static pressure receiving surface is processed with high precision. Thus, the device has been devised to reduce the surface roughness. In the prior art of the above-mentioned Patent Document 4, there is no description regarding the surface state of the mating surface facing the sliding surface provided with the concave portion or the portion of the sliding surface where there is no concave portion. Even in the guide using pressure, it is difficult to form a fluid lubricating oil film that can contribute to the reduction of the sliding friction coefficient unless the surface roughness of the surface other than the surface facing the sliding surface or the groove portion of the sliding surface is small.

  Further, the methods disclosed in Patent Document 5 and Patent Document 6 are provided with a fine recess on one or both of the sliding surfaces in the same manner as the prior art disclosed in Patent Document 1 to Patent Document 3 described above. This method is aimed at improving the lubricity between moving surfaces, but it also aims to improve the lubricity between sliding surfaces by reducing the surface roughness of the surface facing the sliding surface with a recess. It is a thing. Although it becomes the same as the reason demonstrated about patent documents 1-3, since the dent of the method shown in these patent documents forms the independent oil groove where oil grooves are not connected, oil bath The effect cannot be expected unless the condition is such that the lubricating oil is sufficiently supplied as in the lubrication state.

As described above, various methods are disclosed for reducing the sliding friction coefficient of the sliding linear guide having the sliding surface. However, even if these conventional techniques are applied to a sliding linear guide having an open sliding surface, the fluid lubrication film is low, as the surface pressure acting on the sliding surface is low, as in the sliding linear guide of a machine tool. It was difficult to prevent the metal contact between the sliding surfaces by forming the low sliding friction coefficient.
Published on March 30, 2001, edited by Japan Tribology Society, Tribology Handbook, pp. 343-345. Japanese Patent Application Laid-Open No. 2004-308779 Japanese Patent Laid-Open No. 11-63386 JP 2006-17259 A JP 2003-213333 A JP 2002-235852 A JP 2006-17218 A

  In order to realize high-precision and high-efficiency machining of difficult-to-cut materials such as dies, machining with a machine tool equipped with a high-rigidity, high-vibration-damping linear motion guide device is desired. Rolling guides that have been widely used as machine tool linear motion guides have a low rolling friction coefficient and can ensure high positioning accuracy relatively easily. However, the rigidity and vibration damping required for high-efficiency machining of difficult-to-cut materials It could not be said to have sex.

  In recent years, in order to cope with this problem, a sliding guide type linear motion guide has been reviewed as a guide device for machine tools capable of dealing with high-efficiency machining of dies. Since the sliding guide device slides in a state where the sliding surfaces are in surface contact with each other via the lubricating oil, the load capacity is large and the vibration damping property is also high. However, on the other hand, the sliding friction coefficient of the sliding linear guide is higher than the rolling friction coefficient of the rolling guide, and securing the positioning accuracy and increasing the power consumption have been problems.

  Therefore, the problem to be solved by the present invention is to realize a sliding linear motion guide device having a small sliding friction coefficient in a wide sliding speed range as compared with the conventional sliding linear motion guide device.

According to the first aspect of the present invention, lubricating oil is supplied to the gaps between the sliding surfaces of a pair of opposing guide members so as to move relative to each other, and the surface pressure acting on the sliding surfaces is low and released. In a sliding linear guide device having a sliding surface of a mold, a first oil groove for diffusing lubricating oil between the sliding surfaces on the sliding surface of one guide member, and the first oil groove concatenated and the plurality of second oil grooves acting to generate a lubricating oil film pressure between the sliding surface during sliding by the lubricating oil supplied from the first oil groove provided with respective further said one The sliding member is provided with a lubricating oil supply hole connected to the first oil groove.

In the invention of claim 2, the lubricating oil is supplied to the gaps between the sliding surfaces of the pair of opposing guide members so as to move relative to each other, and the surface pressure acting on the sliding surfaces is low and the open type is provided. In a sliding linear motion guide apparatus having a sliding surface, the surface roughness of one or both of the sliding surfaces is set to 1 μmRz or less, and lubricating oil is slid on the sliding surface of one guide member. A lubricating oil film pressure is generated between the sliding surfaces during sliding by a first oil groove for diffusing between the surfaces and the lubricating oil connected to the first oil groove and supplied from the first oil groove. And a plurality of second oil grooves acting so as to cause each of the first guide members to further include a lubricating oil supply hole connected to the first oil groove. It is a guidance device.

  As a precaution, Rz indicates the interval in the direction of the vertical magnification between the peak line and the valley line of the reference length extracted from the roughness curve.

The invention according to claim 3 is the sliding linear guide device according to claim 1 or 2, wherein a plurality of second oil grooves formed on the sliding surface are connected to each other.

The invention according to claim 4 is the sliding linear motion guide device according to claim 1, 2 or 3, wherein the first oil groove or the second oil groove is formed by scraping.

  According to the present invention, the lubricating oil supplied from the lubricating oil supply hole can be diffused over the entire sliding surface by the first and second oil grooves and the oil groove connecting the oil grooves, and the second oil groove. Since the fluid lubrication film can be formed between the sliding surfaces, metal contact between the sliding surfaces can be prevented even in a sliding linear motion guide having a parallel flat sliding surface that slides at a low surface pressure. Therefore, as will be apparent from the description of the embodiments described below, it is possible to realize a sliding linear guide device having a small sliding friction coefficient in a wide sliding speed range as compared with the conventional sliding linear guide device.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

  1 and 2 are a partial cross-sectional view (A-A cross-sectional view in FIG. 2) and a partial plan view, respectively, of a sliding linear motion guide device according to an embodiment of the present invention. 1 and 2, reference numeral 5 denotes a first oil groove provided on the sliding surface 1 of one guide member 4 of a pair of opposing guide members 3 and 4, and 6 denotes a first oil groove 5. The lubricating oil supply hole 7 is connected to the second oil groove 7 on the sliding surface 1, 8 is an oil groove connecting the first oil groove 5 and the second oil groove 7, and 2 is a guide. The sliding surfaces of the member 3 are shown respectively. The first oil groove 5 diffuses the lubricating oil between the sliding surfaces 1 and 2, and the plurality of second oil grooves 7 are lubricated between the sliding surfaces 1 and 2 when sliding with the lubricating oil. Acts to generate pressure.

  FIG. 3 is a schematic diagram of a high-speed sliding friction tester used for measuring the sliding friction coefficient of the sliding linear motion guide model. This sliding friction tester is a device for measuring the sliding frictional force of a slider 4 '(corresponding to one guide member 4) and a plate 3' (corresponding to the other guide member 3), and is applied to a fixed slider 4 '. On the other hand, the plate 3 ′ reciprocates linearly at a sliding speed of 1000 to 50000 mm / min. These frictional forces were detected by the load cell 14 via a wire 15 having a diameter of 0.8 mm attached to the slider 4 '. The vertical load was applied by a weight installed on the table 16, and the vertical load acting on the sliding surface was detected by the load cell. In this example, a vertical load corresponding to a sliding surface pressure of 0.1 MPa was applied between the sliding surfaces. Reference numeral 10 denotes a guide roller.

FIG. 4 shows the shape of the slider sliding surface 1 used in the sliding friction test of this embodiment. A lubricating oil supply hole 6 having a diameter of 4 mm is provided at the center of the slider 4 ′, and the first oil groove 5 according to claim 1 is provided in connection with the lubricating oil supply hole 6. In the present embodiment, the depth of the first oil groove 5 is 1 mm, and the lubricating oil 11 supplied from the lubricating oil supply hole 6 is diffused over the entire sliding surface 1, so that the first groove shape is Z-shaped. However, it is not limited to that. In the sliding friction test, the lubricating oil 11 having a viscosity index VG of 10 was used, and the lubricating oil 11 was quantitatively supplied from the lubricating oil supply hole 6 at 0.06 ml per reciprocating sliding.

  FIG. 5 shows the measurement results of the surface roughness in the region where the first oil groove 5 is not present on the sliding surface 1 of the slider 4 ′. In this embodiment, the sliding surface 1 of the slider 4 'is scraped. As is apparent from the measurement results shown in FIG. 5, the sliding surface 1 forms an oil groove in which a concave portion 7 ′ having a depth of about 10 μm and a concave portion 8 ′ having a smaller groove depth are connected to each other. The second oil groove 7 described in claims and the oil groove 8 described in claim 3 are formed on the sliding surface 1. As in the case of the first oil groove 5 described above, the second oil groove 7, the oil groove 8 connecting them and the processing method thereof are not limited to those described in this embodiment.

  Table 1 shows the material of the slider 4 ′ and the plate 3 ′ used in the sliding friction test and the surface roughness measurement results of the sliding surfaces 1 and 2. However, the surface roughness of the scraped surface shown in Table 1 is a result of measurement in a measurement range including a concave portion subjected to scraping. The sliding surface 2 of the plate 3 ′ according to this example was mirror-finished, and the maximum surface roughness height Rz was finished to 0.12 μm. This maximum surface roughness height Rz of 0.12 μm corresponds to claim 2 of the present invention. Further, in order to clarify the effectiveness of the embodiment according to the present invention, a sliding friction test using a slider 4 ′ obtained by scraping the sliding surface 1 and a ground plate 3 ′ was also performed. The maximum height of the surface roughness of the ground sliding surface was 1.20 μmRz.

FIG. 6 shows a sliding friction test result of the sliding linear motion guide. However, the sliding friction test result of the slider 4 ′ in which the sliding surface 1 is mirror-finished is a test result when the first oil groove 5 is not provided. Compared with the combination of the sliding surfaces 1 and 2 of the conventional scraping surface and the grinding surface, the sliding linear motion guide of the combination of the scraping surface and the mirror surface having the Z-shaped oil groove 5 according to the present invention is provided. The sliding friction coefficient was greatly reduced, and the sliding friction coefficient was 0.01 in the region where the sliding speed was 200 mm / s to 800 mm / s.

It is a partial sectional view showing a sliding linear motion guide device in one embodiment of the present invention. It is a top view which shows the sliding linear guide apparatus in one Example of this invention. It is a figure which shows the sliding friction tester used for the sliding friction test of the sliding linear guide model shown in an Example. It is a figure which shows the sliding face shape of the slider shown in an Example. It is a figure which shows the surface roughness measurement result of the slider sliding surface shown in an Example. It is a figure which shows the measurement result of the sliding friction coefficient of the sliding linear guide model shown in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sliding surface which provided 1st oil groove and 2nd oil groove 2 Sliding surface which opposes the sliding surface which provided 1st oil groove and 2nd oil groove 3 Guide member 4 Guide member 5 1st 1 oil groove 6 lubricating oil supply hole 7 second oil groove 8 oil groove connecting the first oil groove and the second oil groove 10 guide roller 11 lubricant oil 14 load cell 15 wire 16 table

Claims (4)

Lubricating oil is supplied to the gaps between the sliding surfaces of a pair of opposing guide members so as to move relative to each other, and the sliding surface having an open sliding surface has a low surface pressure acting on the sliding surface. In the motion guide device, a first oil groove for diffusing the lubricating oil between the sliding surfaces on the sliding surface of one guide member, and the first oil groove connected to the first oil groove. A plurality of second oil grooves that act so as to generate a lubricating oil film pressure between the sliding surfaces during sliding by the supplied lubricating oil are provided, respectively, and the one guide member is further provided with the first guide A sliding linear motion guide device comprising a lubricating oil supply hole connected to an oil groove. Lubricating oil is supplied to the gaps between the sliding surfaces of a pair of opposing guide members so as to move relative to each other, and the sliding surface having an open sliding surface has a low surface pressure acting on the sliding surface. In the motion guide device, the surface roughness of one or both of the respective sliding surfaces is set to 1 μmRz or less, and the lubricating oil is diffused between the sliding surfaces on the sliding surface of one of the guide members. A plurality of first oil grooves and a plurality of oils connected to the first oil grooves and acting to generate a lubricating oil film pressure between the sliding surfaces during sliding by the lubricating oil supplied from the first oil grooves; A sliding linear motion guide device characterized in that a second oil groove is provided, and a lubricating oil supply hole connected to the first oil groove is provided in the one guide member .   The sliding linear motion guide device according to claim 1 or 2, wherein a plurality of second oil grooves formed on the sliding surface are connected to each other.   The sliding linear motion guide device according to claim 1, 2 or 3, wherein the first oil groove or the second oil groove is formed by scraping.

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