Linear guide device

Abstract

This linear guide device comprises a guide rail 10 extending linearly, and a traveling body 20 capable of traveling along the guide rail 10. The guide rail 10 includes a base portion 11, and a pair of guide portions 12 formed on both sides in the width direction of the base portion 11. Each of the pair of guide portions 12 has guide surfaces 15, 16 on which rollers 25, 26 of the traveling body 20 roll. The guide rail 10 is formed by linearly connecting a plurality of rail members 10A. Each of the adjacent rail members 10A has a main portion 19 and a transition portion 18. Guide surfaces 15T, 16T of the transition portions 18 deviate outward from a virtual extension surface of the guide surfaces 15, 16 of the main portions 18. The amount of deviation from the virtual extension surface increases toward a joint 17. This allows the traveling body to travel stably even if there is a step at the joint of the rail members.

Description

Linear guide device

[0001] The present invention relates to a linear guide device having a guide rail that extends linearly and a running body that runs along the guide rail, and in particular to an improvement in the guide rail.

[0002] As disclosed in Patent Document 1 (Japanese Patent No. 7478909), the guide rail of the linear guide device has a base portion and a pair of guide portions formed on both sides of the base portion in the width direction. Each of the pair of guide portions has at least one guide surface on which the rollers of the traveling body roll.

[0003] The running body is press-fitted into one end of the guide rail, and the roller rolls on the guide surface while a pressing force is applied, thereby allowing the running body to run stably.

[0004] When the guide rail is long, it is constructed by arranging multiple rail members in a straight line. In this case, the ends of adjacent rail members touch or face each other with a small gap between them, forming a joint. If there is even a slight step at the joint, the roller to which pressure is applied will get caught on the step at the joint, making it impossible to run stably.

[0005] The present invention has been made to solve the above-mentioned problems, and provides a linear guide device comprising: a guide rail that extends linearly, having a base portion and a pair of guide portions formed on both sides of the base portion in a width direction, each of the pair of guide portions having at least one guide surface; and a running body that can run along the guide rail, having a running body main body and at least one roller that is rotatably supported on each side of the running body main body and rolls on the guide surface, wherein the guide rail is formed by arranging a plurality of rail members in a straight line and connecting adjacent rail members via joints, each of the adjacent rail members having a main portion extending in the longitudinal direction of the guide rail and a transition portion between the main portion and the joint, and the guide surface of the transition portion is biased outward from an imaginary extension plane of the guide surface of the main portion.

[0006] According to the above-mentioned configuration, the guide surface is biased outward at the transition portion near the joint of the rail member, which weakens the pressing force applied to the roller of the traveling body. As a result, even if there is a step at the joint, the roller can roll without getting caught, ensuring stable running of the traveling body.

[0007] In one embodiment, the guide surface of the transition portion has an inclined region in which the deviation from the imaginary extension plane gradually increases toward the joint. The guide surface of the transition portion may have the inclined region along its entire length. In this case, the deviation from the imaginary extension plane is greatest at the joint.

[0008] In one embodiment, the pair of guide portions at the transition portion of the rail member are bent outward around the connection portion between the pair of guide portions and the base portion, so that the guide surfaces at the transition portion are biased outward from the imaginary extension plane. With this configuration, the guide surfaces at the transition portion can be biased outward with a relatively simple process.

[0009] According to the present invention, even if there is a step at the joint of the rail members, the traveling body can travel stably.

[0010] 1. A perspective view of a linear guide device according to a first embodiment of the present invention, as seen from above. 2. An exploded perspective view of a running body of the linear guide device. 3. A bottom view of the running body. 4. A top view of a guide rail of the linear guide device. 5. A front view of a rail member constituting the guide rail, as seen from a joint. 6. A cross-sectional view taken along arrows VI-VI in FIG. 5. 7. A front view taken along arrows VII-VII in FIG. 1. 8. A cross-sectional view of a linear guide device according to a second embodiment of the present invention, showing a state in which the running body is running on a main part of the rail member away from a joint. 9. A front view of a rail member of a guide rail of the second embodiment, as seen from a joint. 10. A view equivalent to FIG. 7, showing a linear guide device according to a third embodiment of the present invention.

[0011] A linear guide device according to a first embodiment of the present invention will be described below with reference to Figures 1 to 7. As shown in Figure 1, the linear guide device comprises an elongated metal guide rail 10 that extends linearly, and a metal running body 20 that can run along the longitudinal direction of the guide rail 10. In this embodiment, the guide rail 10 is disposed horizontally on the lower side, and the running body 20 is disposed on the upper side.

[0012] <Basic configuration of guide rail> The guide rail 10 has a flat, elongated base portion 11, a pair of elongated guide portions 12 formed symmetrically on both sides of the base portion 11 in the left-right direction (width direction), and an open portion 13 formed between the pair of guide portions 12. The base portion 11 and the open portion 13 face each other in the vertical direction. The base portion 11 is configured to be fixed to the top surface of a first object, for example, a stationary object.

[0013] Each guide portion 12 has a plate shape with a V-shaped cross section, and its inner surfaces serve as a first guide surface 15 and a second guide surface 16. The first guide surface 15 on the lower side close to the base portion 11 is connected to the base portion 11 at an obtuse angle of 135°, and the second guide surface 16 on the upper side close to the open portion 13 is connected to the first guide surface 15 at an angle of 90°. The first guide surfaces 15 of the pair of guide portions 12 are inclined so as to widen toward the open portion 13, and the second guide surfaces 16 of the pair of guide portions 12 are inclined so as to converge toward the open portion 13.

[0014] <General Configuration of Running Body> As shown in Figures 2 and 3, the running body 20 includes a running body main body. This running body main body is configured by connecting a main holder 21 and an auxiliary holder 22 below it at their centers with a connecting shaft member 23. The main holder 21 has multiple, for example, four, support plate portions 21a inclined downward at 45°, and a first roller 25 is rotatably supported by each support plate portion 21a via a roller shaft member 25a. The auxiliary holder 22 has multiple, for example, four, support plate portions 22a inclined upward at 45°, and a second roller 26 is rotatably supported by each support plate portion 22a via a roller shaft member 26a.

[0015] <Installing the Running Body into the Guide Rail> The running body 20 having the above-described configuration is installed by press-fitting it into one end of the guide rail 10. With this installation, as shown in Fig. 7, the main holder 21 is positioned above the guide rail 10, and the sub-holder 22 and rollers 25, 26 are housed within the guide rail 10. Note that a moving object (second object) is fixed to the main holder 21.

[0016] In the assembled state, the first roller 25 of the running body 20 abuts against the first guide surface 15 of the guide rail 10, and the second roller 26 abuts against the second guide surface 16. As described above, the running body 20 is press-fitted into the guide rail 10, and therefore the rollers 25, 26 abut against the guide surfaces 15, 16 while applying a pressing force, with some elastic deformation of components such as the support plate portions 21 a, 22 a. When the running body 20 runs along the guide rail 10, the rollers 25, 26 roll on the guide surfaces 15, 16 while applying a pressing force, thereby ensuring stable running.

[0017] <Detailed Structure of the Guide Rail> As shown in FIGS. 1 and 4 , the guide rail 10 of this embodiment is constructed by arranging multiple rail members 10A having the above-described cross-sectional shape in a straight line and fixing the base portions 11 of the multiple rail members 10A to a stationary object with screws or the like (not shown). Adjacent rail members 10A are essentially connected, with their ends either touching or facing each other at a small distance. These ends form a joint 17. At this joint 17, a slight step may occur between the guide surfaces 15, 16 of adjacent rail members 10A due to assembly errors or the like. In this case, because the rollers 25, 26 are in contact with the guide surfaces 15, 16 while applying a pressing force, the joint 17 may catch on the step between the guide surfaces 15, 16, potentially hindering stable running.

[0018] 4, in this embodiment, each rail member 10A has a transition portion 18 extending over a predetermined length from the end that forms the joint 17. The main portion 19 excluding the transition portion 18 has the same cross-sectional shape along the longitudinal direction, similar to a normal guide rail.

[0019] 4 shows an example in which the guide rail 10 is constructed using two rail members 10A. In this case, each rail member 10A has a main portion 19 and one transition portion 18. When the guide rail 10 is constructed using three or more rail members 10A, the rail members 10A at both ends have a main portion 19 and one transition portion 18, and the middle rail member 10A has a main portion 19 and two transition portions 18.

[0020] The transition portions 18 of adjacent rail members 10A have substantially the same dimensions and shape. The shape of the transition portions 18 will be described below with reference to FIGS. 5 and 6. The guide portion of the transition portion 18 is designated by the reference numeral 12T, and the first and second guide surfaces are designated by the reference numerals 15T and 16T, respectively, to distinguish it from the guide portion 12 and guide surfaces 15, 16 of the main portion 19. The first guide surface 15T of the transition portion 18 is biased outward relative to an imaginary longitudinal extension 15' of the first guide surface 15 of the main portion 19. This bias gradually increases toward the joint 17 and is greatest at the end located at the joint 17. As a result, the first guide surface 15T of the transition portion 18 is inclined relative to the imaginary longitudinal extension 15' of the first guide surface 15 of the main portion 19 throughout its entire length. This inclination angle is 0.5° to 1°, but the inclination angle and amount of deviation are exaggerated in Figures 5 and 6 for ease of understanding. Similarly, the second guide surface 15T of the transition portion 18 is biased outward with respect to an imaginary longitudinal extension plane of the second guide surface 16 of the main portion 19. The amount of deviation increases toward the joint 17 and is greatest at the end located at the joint 17. At the joint 17, the end faces of the transition portions 18 of adjacent rail members 10A have substantially the same shape and are in surface contact or face each other with a small gap between them.

[0021] As described above, because the guide surfaces 15T, 16T of the transition portion 18 are biased outward with respect to the imaginary longitudinal extension plane of the guide surfaces 15, 16 of the main portion 19, the amount of elastic deformation of the support plate portions 21a, 22a, etc. is reduced, and the rollers 25, 26 roll on the guide surfaces 15T, 16T with a weakened pressing force. This pressing force is minimized at the joint 17. As a result, even if there is a slight step between the first guide surfaces 15T or the second guide surfaces 16T of adjacent rail members 10A at the joint 17, no snagging occurs, allowing for smooth running.

[0022] In this embodiment, the guide portions 12T are bent outward around the left and right ends of the base portion 11, i.e., the connecting portions 12x between the base portion 11 and the guide portions 12T, thereby biasing the guide surfaces 15T and 16T outward. Therefore, the guide surfaces 15T and 16T can be biased outward with simple machining. A longitudinally extending groove 12y is formed inside the connecting portions 12x.

[0023] 7, when the guide portion 12T is bent outward, the guide surfaces 15T, 16T are inclined relative to the circumferential surfaces of the rollers 25, 26 rolling on the guide surfaces 15, 16 of the main portion 19. However, the rollers 25, 26 can roll in line contact with the guide surfaces 15T, 16T of the transition portion 18 as viewed from the running direction, just as when they roll on the guide surfaces 15, 16 of the main portion 19. This is because the inclination of the guide surfaces 15T, 16T relative to the rollers 25, 26 is slight, and because the posture of the rollers 25, 26 changes so as to compensate for the inclination of the guide surfaces 15T, 16T relative to the rollers 25, 26 due to elastic deformation of the support plate portions 21a, 22a that support the rollers 25, 26.

[0024] <Other Embodiments> Hereinafter, other embodiments of the present invention will be described. In a second embodiment, as shown in Fig. 8, a pair of guide portions 112 of a guide rail 110 are curved to have a C-shaped cross section, and a first guide surface 115 and a second guide surface 116 are concavely curved. Correspondingly, the outer peripheries of a first roller 125 and a second roller 126 of a running body 120 have convexly curved cross-sectional contours. As in the first embodiment, two first rollers 125 are arranged on each side, and two second rollers 126 are also arranged on each side. The structure of the running body main body of the running body 120 is the same as in the first embodiment, and therefore description thereof will be omitted.

[0025] 9, at the transition portion of the rail member 110A that constitutes the guide rail 110, a pair of guide portions 112T are bent so as to widen to the left and right at the connecting portion 112x with the base portion 111, and the guide surfaces 115T and 116T are biased outward from the imaginary extension plane of the guide surfaces 115 and 116 of the main portion. The amount of this bias gradually increases toward the joint and is maximum at the joint.

[0026] In the third embodiment shown in Figure 10, a pair of guide portions 212 of a guide rail 210 stand upright from both sides of a base portion 211. The upper portion of each guide portion 212 forms an arc, and its inner surface serves as a single guide surface 215. A running body 220 has a single holder 221 as the running body main body, and two rotatably supported rollers 225 provided on each side of the holder 221. The rollers 225 roll on the guide surface 215 around a rotation axis perpendicular to the base 211 of the guide rail 210.

[0027] The guide portion 212T at the transition portion of the rail member 210A is bent outward around the connecting portion 212x with the base portion 211, so that the guide surface 215T is biased outward in the width direction from the imaginary extension plane of the guide surface 215 of the main portion, and the amount of bias gradually increases toward the joint and reaches a maximum at the joint.

[0028] The present invention is not limited to the above-described embodiment and can employ various modifications. For example, only a portion of the guide surface of the transition portion may be an inclined region. The number of rollers rolling on the common guide surface is not limited to two, but may be one, three, or more.

[0029] The present invention can be applied to a linear guide device.

[0030] 10, 110, 210 Guide rail 10A, 110A, 210A Rail member 11, 111, 211 Base portion 12, 112, 212 Guide portion 12T, 112T, 212T Guide portion of transition portion 12x, 112x, 212x Connection portion 15, 16, 115, 116, 215 Guide surface 15T, 16T, 115T, 116T, 215T Guide surface of transition portion 15' Virtual extension surface 17 Joint 18 Transition portion 19 Main portion 20, 120, 220 Running body 25, 26, 125, 126, 225 Roller

Claims

1. A linear guide device comprising: a guide rail that extends linearly and has a base portion and a pair of guide portions formed on both sides of the base portion in the width direction, each of the pair of guide portions having at least one guide surface; and a running body that can run along the guide rail and has a running body main body and at least one roller that is rotatably supported on each side of the running body and rolls on the guide surface; wherein the guide rail is formed by arranging multiple rail members in a straight line and connecting adjacent rail members via joints, each of the adjacent rail members having a main portion extending in the longitudinal direction of the guide rail and a transition portion between the main portion and the joint, and the guide surface of the transition portion is biased outward from an imaginary extension of the guide surface of the main portion.

2. The linear guide device according to claim 1, wherein the guide surface of the transition portion has an inclined region in which the amount of deviation from the virtual extension surface gradually increases toward the joint.

3. The linear guide device according to claim 2, wherein the guide surface of the transition portion has the inclined region over the entire length, and the amount of deviation from the virtual extension surface is greatest at the joint.

4. A linear guide device as described in claim 1, characterized in that, in the transition portion of the rail member, the pair of guide portions are bent outward around the connection portion between the pair of guide portions and the base portion, thereby causing the guide surface of the transition portion to be biased outward from the imaginary extension plane.

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