Flat roller

Abstract

To provide a double row linear flat roller that can bring an angle between adjacent two flat surfaces of a retainer closer to a desired finish angle precisely.SOLUTION: A flat roller includes: a plurality of rollers installed so as to be rotatable along a slide surface to be rectilinearly guided; and a retainer for retaining the rollers, where the rollers are arrayed in parallel with the slide surface. The retainer includes a bending part that is bendable as a joint part between the rows, where the bending part is made of a material that makes the deformation rate 50-90%.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flat roller that can be widely used in industrial machines, and more specifically, to a flat roller that can be used in places that require linear reciprocating motion, such as the table of a machine tool. [Background technology]

[0002] Conventionally, there has been known a double-row flat roller in which rollers are arranged in multiple parallel rows, and in which the joints between the rows can be bent and deformed at any angle so that they can be incorporated into a V-shaped sliding surface (for example, Patent Document 1).

[0003] In the double row flat roller described in Patent Document 1, the cages of each row are connected to each other on the upper and lower sides by thin resin plates. In a flat roller with such a configuration, when only the plate on the lower side is bent, the plate on the upper side stretches in a flat state without bending, and the plate on the upper side is fixed in a stretched state, so that it can be bent while maintaining the desired bending angle. However, after bending, the cage becomes trapezoidal, which may cause interference, making it difficult to attach it to a V-shaped surface.

[0004] On the other hand, in order to attach flat rollers to a V-shaped surface, two methods were considered: installing a single row of flat rollers on both sides of the V-shaped surface, or heating a double row of flat rollers and bending them into a V shape starting from the joints between the rows and fitting this to the V-shaped surface. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 6-52084 Summary of the Invention [Problem to be solved by the invention]

[0006] However, using a single-row flat roller for a sliding surface inclined into a V-shape increases costs, and when using double-row flat rollers that are plastically deformed to a desired angle, it is difficult to precisely adjust the bending angle to match the inclination angle of the V-shape surface, which increases the number of manufacturing steps.

[0007] In view of the above circumstances, an object of the present invention is to provide a technique that can accurately bring the angle between two planes forming adjacent double rows of flat rollers close to a desired finish angle. [Means for solving the problem]

[0008] The flat roller of the present invention comprises a plurality of rollers arranged so as to be able to roll along a linearly guided sliding surface, and a retainer for holding these rollers, the plurality of rollers being arranged in double rows parallel to the sliding surface, the retainer having a bent portion which can be bent as a joint between the rows, and made of a material in which the deformation rate of the bent portion when bent by heat treatment is 50% to 90%. Here, the "deformation rate" is a value expressed as a percentage of the ratio of the finished angle after bending to the set angle set in the jig used for bending. According to this configuration, by deforming the bent portion in consideration of the deformation rate, the angle between adjacent sliding surfaces can be made to approach the finished angle with high precision.

[0009] For example, in the flat roller according to the present invention, the cage is made of a relatively inexpensive polyamide resin. In this case, by determining the setting angle of the jig taking into consideration the material properties, such as the thermal deformation temperature of the polyamide resin, it is possible to set the sliding surface of the flat roller to the desired angle with high precision.

[0010] Preferably, the cage made of polyamide resin is bent at a heating temperature of 70°C or more and 120°C or less. According to this configuration, the angle between adjacent sliding surfaces of the flat roller can be made to approach the finished angle with high precision without causing deterioration of the material of the flat roller.

[0011] Preferably, the bent portion of the flat roller according to the present invention has a thickness of 0.5 mm or less. According to this configuration, the flat roller can be thermally deformed more flexibly.

[0012] In the following description of this specification, the "longitudinal direction" refers to the direction in which the flat roller linearly guides an object, specifically the direction in which three or more rollers are arranged parallel to one another. In addition, in this specification, the "width direction" refers to the direction perpendicular to the longitudinal direction and in the arrangement plane in which the rollers are arranged parallel to one another. In other words, in this specification, the "width direction" refers to the axial direction of the rollers. Effect of the Invention

[0013] According to the present invention, it is possible to accurately bring the angle between two flat surfaces forming adjacent double rows of flat rollers close to a desired finishing angle. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a plan view of a flat roller according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 4 is a front view showing a state in which the flat roller is used. [Figure 4A] 13 is a front view of a jig for thermally deforming and bending the cage of the flat roller of FIG. [Figure 4B] FIG. [Diagram 5] 5A to 5C are schematic diagrams illustrating the angles of the cage. [Figure 6] 1 is a graph showing the relationship between the amount of heat (J) and the deformation rate (%) observed when a test piece was bent at a set angle of 45° by test A or B. [Figure 7] 1 is a graph showing the relationship between the amount of heat (J) and the deformation rate (%) observed when a test piece was bent at a set angle of 90° by test A or B. [Figure 8] 1 is a graph showing the relationship between heat removal time (s) and deformation rate (%) when a test piece larger than the standard size is bent on a flat roller at a set angle of 45° or 90° using test A or B. [Figure 9] 1 is a graph showing the relationship between heat removal time (s) and deformation rate (%) when a standard-sized test piece was bent on a flat roller at a set angle of 45° or 90° using tests A or B. [Figure 10] This is a graph showing the relationship between the heat removal time (s) and the deformation rate (%) when a test piece smaller than the standard size was bent on a flat roller at a set angle of 45° or 90° using tests A or B. [Figure 11] 1 is a graph showing the correlation between a desired angle (θx) between two adjacent planes of a flat roller and an actual angle (θy) after thermal deformation, assuming that the deformation rate is constant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] [First embodiment: FF ZW type, Figs. 1-2] The flat roller according to this embodiment will be described with reference to the drawings. The flat roller according to this embodiment is a double-row type, and by bending the sliding surface 31 of one row relative to the sliding surface 32 of the other row, it can be applied to a V-shaped inclined slide surface of a machine tool, for example, and can cause an object to move back and forth linearly.

[0016] <Outline of the flat roller structure> 1 is a plan view showing a schematic configuration of a flat roller 30 according to an embodiment of the present invention. The flat roller 30 according to this embodiment is a double-row linear flat roller, and includes a cage 10 and a plurality of rollers 20.

[0017] The cage 10 has multiple (two in this embodiment) plates 11, 12 that are rectangular in plan view. Both adjacent long sides of the plates 11, 12 are connected to a bent portion 16 that extends in the longitudinal direction at the boundary between the plates 11, 12, and the plates 11, 12 extend parallel to each other across the bent portion 16 in the longitudinal direction, which is the direction in which an object is linearly guided. In this embodiment, the plates 11, 12 and the bent portion 16 are integrally formed from the same material. In this specification, "integral" or "integrally" refers to something that is made of a single material and is molded as part or all of a single object by, for example, machining, rather than being made of multiple components joined together in a later process.

[0018] The plate 11 is provided with a plurality of pockets 13 for accommodating rollers (rolling elements). Each pocket 13 is a hole penetrating the plate 11 in the thickness direction and has a shape extending in the width direction. The multiple pockets 13 are arranged parallel to one another and spaced apart from one another in the longitudinal direction. A roller 20 is accommodated in each pocket 13 so as to be rotatable about its axis. The multiple pockets 14 provided in the plate 12 have the same function and shape as the multiple pockets 13 provided in the plate 11, so a detailed description thereof will be omitted.

[0019] The rollers 20 housed in each of the pockets 13, 14 are cylindrical or columnar rotating bodies (rolling bodies) and are provided so as to be rotatable in the circumferential direction about their axes. The rollers 20 are easily attachable to and detachable from the pockets 13, 14. The rollers 20 may be, for example, needle rollers or rolling rollers having a larger radial dimension than a needle roller.

[0020] The arrangement of the pockets 13 and / or rollers 20 on the plate 11 described above forms a first row that slides on one sliding surface 31 in Fig. 3. The arrangement of the pockets 14 and / or rollers 20 on the plate 12 described above forms a second row that slides on the other sliding surface 32. The sliding surfaces 31, 32 are provided so as to be located on, for example, a table 40 of a machine tool. The first row and the second row are arranged so as to be aligned side by side in the width direction.

[0021] The bent portion 16 is a thin-walled portion located at the boundary between the first row and the second row. The bent portion 16 extends in the longitudinal direction parallel to the first row and the second row. The bent portion 16 in this embodiment connects the ends of the plates 11 and 12 on one side in the thickness direction on the opposing surfaces of the plates 11 and 12. As described later, the bent portion 16 is deformed by applying heat or the like, thereby bending the flat roller 30 and changing the angle between the plates 11 and 12 to a desired finished angle.

[0022] Engagement portions 17, 17 that are trapezoidal in plan view are provided at the ends of the plates 11, 12 on one side of the linear reciprocating motion (one side in the longitudinal direction in this embodiment). Meanwhile, dovetail-shaped engaged portions 18, 18 are provided at the ends of the plates 11, 12 on the other side in the linear guiding direction (the other side in the longitudinal direction in this embodiment). The engagement portion 17 has a shape that corresponds to the engaged portion 18. With this configuration, it is possible to use the flat rollers 30 with any number of cages 10 connected vertically in the longitudinal direction.

[0023] In the longitudinal center of the bent portion 16 of the cage 10 of this embodiment, a long hole 19 is provided penetrating the bent portion 16 in the thickness direction. By providing this long hole 19 that is long in the longitudinal direction, it is possible to reduce the weight of the flat roller 30. In addition, during the bending process described below, the operator can conveniently use this long hole 19 to position a jig 60 (described later) at an appropriate location between the plates 11 and 12.

[0024] <Details of the bending section configuration> The configuration and function of the bending portion 16 will be described in detail below.

[0025] The flat roller 30 of this embodiment may be made of polyamide resin. More preferably, the plates 11, 12 and the bent portion 16 may be integrally formed of the same material, and the common material may be polyamide resin. In this case, the temperature of the heat treatment (heating treatment) when bending the flat roller 30 may be a temperature below the lower limit of the usable heat resistance temperature, taking into account the heat resistance of this material. Specifically, when a polyamide resin with a usable heat resistance temperature of 120 to 150°C is used as the material of the flat roller 30, the temperature of the heat treatment during bending may be 70 to 120°C, preferably 80 to 110°C. The flat roller 30 is preferably made of a material that provides a deformation rate of the bent portion 16 of 50 to 90%, preferably 50 to 80%.

[0026] The thickness of the bent portion 16 in the direction perpendicular to the longitudinal direction and the width direction is smaller than the thicknesses of the plates 11 and 12, which are defined similarly. Specifically, the thicknesses of the plates 11 and 12 are, for example, 0.8 to 3.0 mm, preferably 1.0 to 2.8 mm, and more preferably 1.5 to 2.5 mm. On the other hand, the thickness of the bent portion 13 before bending, which will be described later, is, for example, 0.1 to 0.7 mm, preferably 0.2 to 0.6 mm, more preferably 0.3 to 0.5 mm, and most preferably 0.4 mm or more and 0.5 mm or less. In this way, by making the thickness of the bent portion 16 thinner than the thickness of the plates 11 and 12, it becomes easier to deform the flat roller 30.

[0027] The method of bending the flat roller 30 according to the present invention will be described in detail below. There are two methods of bending, which will be described in order.

[0028] <First bending method> (Test A described later corresponds to this method.) First, a container containing oil is placed in a thermostatic bath and heated until the temperature of the oil reaches 80° C. The cage 10 with the rollers 20 removed is immersed in this heated oil and heating is continued for 10 minutes (first heating step).

[0029] After the 10-minute heating is completed, the retainer 10 is removed from the oil, and the retainer 10 is bent along the set angle of the jig 60 (bending step). Here, the jig 60 may be any known bending tool or device, but may be, for example, a plate-like member with a large thickness as shown in FIG. 4A (see FIG. 4B for the thickness), and the set angle θ may be α1 (e.g., 45°) at the first corner C1, α2 (e.g., 60°) at the second corner C2, and α3 (e.g., 90°) at the third corner C3. The jig 60 can change the angle between the adjacent plates 11 and 12, for example, by pressing the arrangement surfaces of the plates 11 and 12 against both sides (flat surfaces) that form one of these corners and performing heat treatment. In this case, the intersection (vertex) of the two sides that form the set angle to be applied this time among the vertices of the jig 60 is arranged so as to correspond to the bent portion 16.

[0030] When the plates 11, 12 are aligned along both sides of the jig 60, the cage 10 is fixed to the jig 60 in this state, and heat is removed for a predetermined time (five minutes in this embodiment) (heat removal step). The heat may be removed by exposing the material to room temperature, or by actively cooling the material using cooling water or the like.

[0031] After the heat removal for a predetermined time has been completed, the jig 60 is removed from the retainer 10, the above-mentioned fixed state is released (removal step), and this state is left at room temperature for several hours.

[0032] Next, the angle between plate 11 provided corresponding to sliding surface 31 in FIG. 3 and plate 12 provided corresponding to sliding surface 32 is measured using a known means such as a protractor, and the deformation ratio, which indicates the magnitude of the actual angle relative to the desired angle (target angle) that the operator wanted to achieve as the finished angle, is calculated according to the following formula (deformation ratio measurement process).

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[0033] Finally, by substituting the deformation rate obtained above and the desired angle (i.e., the set angle of the jig) into the following equation, a calibration curve can be obtained that shows the relative relationship between the set angle of the jig to be used in the bending process and the finished angle expected to be achieved by using it (in the equation below, α represents the rate of change, θx represents the desired angle, and θy represents the actual angle after thermal deformation).

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[0034] Depending on the shape and configuration of the jig, a jig such as that shown in FIG. 4A, which has the set angle calculated above as its inherent angle, may be selected (from a number of options), or a jig with a variable set angle may be used by adjusting the angle so that it forms the set angle calculated above.

[0035] With this configuration, the set angle of the jig to be used in the subsequent bending process can be obtained based on a simple measurement and calculation method, which makes it possible to precisely set the angle between the two adjacent planes (surfaces of plates 11 and 12) of flat roller 30 to the desired finished angle.

[0036] <Second bending method> (Test A described later corresponds to this method.) Next, the second folding method will be described. The differences from the above-mentioned first folding method are mainly in the following three points.

[0037] First, the second bending method is different from the first bending method in that not only the retainer but also the jig 60 is heated in the first heating step. According to this configuration, it is possible to suppress the risk that a part of the heat of the retainer 10 is transferred to the jig 60 during the bending process, causing a drop in the temperature of the bent portion 16 and making it difficult to thermally deform the bent portion 16.

[0038] Secondly, the second bending method differs from the first bending method in that it includes a second heating step, which is performed after the bending step and before the heat removal step, in which the retainer 10 and the jig 60 are further heated while keeping the jig 60 acting on the retainer 10. According to this configuration, by performing the second heating step in addition to the first heating step, a sufficient amount of heat can be supplied to the retainer 10, and the retainer 10 can be thermally deformed more flexibly.

[0039] Thirdly, in the second bending method, the time required for removing heat in the heat removal step while the retainer 10 is fixed to the jig 60 is longer than the time required for the first bending direction (10 minutes in this embodiment). According to this configuration, the heat removal time can be changed depending on whether the jig 60 was heated in the first heating step, that is, depending on the amount of heat that is likely to remain when the cage 10 and the jig 60 are viewed as a whole, and wasteful heat removal time can be eliminated and the cage 10 can be efficiently thermally deformed and bent. In other words, when an improvement in the deformation rate cannot be expected even if the heat removal time is extended (specifically, after 5 minutes have elapsed in the heat removal step of the first bending method), the heat removal is stopped early, and the time efficiency in performing the bending process can be improved.

[0040] In the following, various data obtained when the first bending method (Test A) and the second bending method (Test B) were performed on a test piece, which was a sample of a flat roller retainer, will be described with reference to Figs. 6 to 11. In these figures, the four numbers written in parentheses, for example "test piece 45 (45 x 35 x 2.0 x 0.4)", represent, from left to right, the length L of the test piece, the width W of the test piece, the thickness T1 (of the plate part) of the test piece, and the thickness T2 of the bent part.

[0041] 6 to 11 show data obtained by heating a cage sample and bending it using a jig. Increasing the temperature of the cage makes it easier to deform, but the resin material of the cage deteriorates or melts. In the present invention, the cage is immersed in oil heated to 80°C, a temperature at which the resin does not deteriorate or melt. As can be seen from FIGS. 6 to 11, the deformation rate is kept to 50 to 80%. This makes it possible to obtain a sufficient deformation rate without damaging the cage material. If the deformation rate is less than 50%, the bending angle does not reach the set angle. On the other hand, if the deformation rate exceeds 80%, the bending angle will be bent more than the set angle, and it may be difficult to achieve the set angle. The maximum allowable deformation rate is 50 to 90%. FIG. 6 is a graph showing the relationship between the amount of heat (J) of the combined cage and jig and the deformation rate (%) of the cage, obtained when three cage samples of different sizes were bent at a set angle of 45° using test A or test B. FIG. 7 is a graph showing the relationship between the amount of heat (J) of the combined cage and jig and the deformation rate (%) of the cage, obtained when three cage samples of different sizes were bent at a set angle of 90° using test A or test B.

[0042] According to the data shown in Figures 6 and 7, when comparing the results of Test A and Test B, the heat generated by the cage and jig combined was much greater in Test B, and the deformation rate was also higher. In other words, it can be seen that the deviation between the angle set by the jig and the angle actually achieved was smaller in Test B than in Test A.

[0043] FIG. 8 is a graph comparing the deformation rate when a sample of a cage larger than the standard size was bent at a set angle of 45° or 90° by applying Test A and Test B, and when the heat removal time was set to 5 minutes or 10 minutes. FIG. 9 is a graph comparing the deformation rate when a standard size cage sample is bent at a set angle of 45° or 90° by applying Test A and Test B, and when the heat removal time is set to 5 minutes or 10 minutes. FIG. 10 is a graph comparing the deformation rate when a cage sample smaller than the standard size is bent at a set angle of 45° or 90° by applying Test A and Test B, and when the heat removal time is set to 5 minutes or 10 minutes.

[0044] According to the data shown in Figures 8, 9 and 10, in Test A, in which the jig was not heated, there was no significant difference in the deformation rate whether the heat removal time was 5 minutes or 10 minutes. In other words, if the heat removal time was 5 minutes or more, the deformation rate seemed to plateau. On the other hand, in Test B, in which not only the cage sample but also the jig was heated, it was found that the deformation rate continued to increase over time even if the heat removal time exceeded 5 minutes. Therefore, when the jig is heated, it is presumed that the finished angle can be made closer to the ideal by extending the heat removal time (for example, 5 minutes or more, preferably about 10 minutes).

[0045] Fig. 11 is a graph showing the correlation between the angle (θx) set in the jig as the desired angle between two adjacent planes (surfaces of plates 11 and 12) of the cage sample and the actual finished angle (θy) after the thermal deformation process, assuming that the deformation rate is constant. In Fig. 11, inclined straight lines are drawn as calibration curves to roughly grasp the correlation for each of the cases of test A and test B.

[0046] 11, it is possible to roughly estimate the actual bending angle that will be achieved when the jig setting angle (θx) is set to a certain degree. By using a calibration curve showing such a correlation, it is believed that it will be possible to achieve a finished angle, i.e., a deformation rate, that is closer to the target when subsequently bending a cage made of the same material.

[0047] <Modification> In the above embodiment, the entire retainer is immersed in oil and heated, but this is not limited to this, and instead, only a portion of the retainer, including the bent portion, may be immersed in oil.

[0048] In the above embodiment, the plates 11, 12 and the bent portion 16 of the cage are integrally formed from the same material, but this is not limited thereto, and the plates and the bent portion may be made from different materials. In other words, the cage 10 may be integrally formed from two or more different materials.

[0049] The flat roller 30 in the above embodiment has a structure including an engaging portion 17, an engaged portion 18, and a long hole 19, but such detailed configurations are not essential and can be omitted, or other known configurations can be added.

[0050] In the above embodiment, the direction in which three or more rollers 20 (and pockets 13) are arranged in a plane is the longitudinal direction of the flat roller 30, and the direction in which the rollers 20 (and pockets 13, 14) are arranged side by side is the width direction, but this is not limited to this, and the longitudinal direction and width direction may be interchanged.

[0051] The present invention as described above includes the following methods.

[0052] The method for bending a flat roller by thermal deformation according to the present invention includes the steps of: A cage having a plurality of rollers, a plurality of pockets for accommodating the rollers being arranged in double rows at intervals from each other so as to be side-by-side on adjacent plates and along a sliding surface inclined in a V shape, and a bent portion that can be bent is provided at the boundary between the double rows, A method for bending a plate by thermally deforming the bent portion so that one plate is finished at a desired angle relative to the other plate, comprising: a first heating step of heating the retainer; a bending step of bending the heated retainer along a set angle set in a jig used for bending the retainer; a heat removal process of removing heat from the retainer while the retainer is fixed to the jig; a detachment step of detaching the jig from the retainer; A method in which the angle between adjacent plates is measured to obtain in advance a deformation rate that indicates the size of the actual angle relative to the desired angle, and if the obtained deformation rate is within the range of 50% to 90%, the deformation rate and the desired angle are substituted into the following equation to calculate a set angle of the jig to be used in the bending process, and the jig adjusted to the set angle is used in a subsequent bending process of a retainer made of the same material (in the following equation, α represents the rate of change, θx represents the desired angle, and θy represents the actual angle after thermal deformation).

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[0053] This configuration allows for a simple measurement and calculation method to determine the set angle of the fixture to be used in the subsequent bending steps, allowing the angle between adjacent plates of the flat roller to be accurately adjusted to the desired finished angle.

[0054] Preferably, in the method for thermally deforming and bending a retainer of a flat roller according to the present invention, the first heating step heats the jig in addition to the retainer. According to this configuration, it is possible to avoid a situation in which a portion of the heat of the retainer is transferred to the jig during the bending process, causing the temperature of the bent portion to drop and making thermal deformation difficult.

[0055] Preferably, the method of thermally deforming and bending a flat roller according to the present invention further comprises a second heating step, after the bending step and before the heat removal step, of heating the retainer and the jig while the jig is acting on the retainer. According to this configuration, the second heating step is further performed in addition to the first heating step, so that the flat roller can be thermally deformed more flexibly.

[0056] Preferably, in the method of thermally deforming and bending a flat roller according to the present invention, if the jig is heated in addition to the retainer in the first heating step, the heat removal time in the heat removal step is set longer than if the jig is not heated. According to this configuration, the heat removal time can be changed depending on whether or not the jig is heated in the first heating process, eliminating unnecessary heat removal time and efficiently thermally deforming and bending the retainer.

[0057] Although the embodiment for carrying out the present invention has been described above, the embodiment disclosed herein is illustrative in all respects and is not restrictive. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0058] 10...Cage 11. Plate 12…Plate 13…Pocket 14…Pocket 16…Bent section Around 20 30...Flat roller 31...Sliding surface 32...Sliding surface 40...machine tool table 60…Jig

Claims

1. A flat roller comprising a plurality of rollers provided so as to be capable of rolling along a linearly guided sliding surface, and a cage for holding the plurality of rollers, the plurality of rollers being arranged in double rows parallel to the sliding surface, The flat roller retainer has a bent portion that can be bent as a joint portion between rows, and is made of a material with a deformation rate of the bent portion of 50% to 90%.

2. 2. The flat roller according to claim 1, wherein the cage is made of a polyamide resin.

3. 3. The flat roller according to claim 2, wherein the retainer is bent at a heating temperature of 70° C. or more and 120° C. or less.

4. 3. The flat roller according to claim 1, wherein the bent portion has a thickness of 0.5 mm or less.

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