JP5111239B2 - Linear guide device - Google Patents

Description

  The present invention relates to a linear guide device in which a moving block is assembled to a track rail via a large number of balls, and a movable body fixed to the moving block can freely reciprocate along the track rail. .

  In a work table of a machine tool and a linear guide portion of various conveying devices, a linear guide device in which a moving block on which a movable body such as a table is continuously moved along a track rail is frequently used. In this type of linear guide device, the track rail and the moving block are assembled through a large number of balls, and the balls roll while applying a load between the moving block and the track rail. The movable body mounted on the moving block can be moved lightly with very little resistance along the track rail. Further, the moving block is provided with an infinite circulation path of the ball, and the moving block can continuously move along the track rail by circulating the ball in the infinite circulation path. Yes.

  In such a linear guide device, a track rail is laid on a fixed portion such as a base or a column, while the movable body is fixed to a moving block that moves along the track rail, and the movable body is fixed to the fixed portion. It was possible to guide in a fixed posture.

  The track rail is formed with ball rolling grooves along the longitudinal direction, while the moving block is formed with a load rolling groove opposite to the track rail rolling grooves. Roll while touching the groove and load rolling groove. The number of rolling grooves formed on the track rail varies depending on the load capacity required for the linear guide device, but in the case of a small linear guide device suitable for light load applications, one strip is provided on both sides of the track rail. The mainstream is formed with each rolling groove.

Conventionally, as a manufacturing method of the track rail, first, a rod-shaped steel material is drawn, and an approximate cross-sectional shape of the track rail is given to the rod-shaped steel material, and then grinding is performed to perform the rolling. The running groove was machined with high accuracy. In order to carry out the grinding process, it is necessary to fix the track rail to be processed to the grinding machine with high accuracy. For this reason, the track rail is processed with a bottom surface serving as a grinding processing standard after the drawing process. The rolling groove is ground with respect to the track rail with reference to. That is, the processed track rail has a laying direction with respect to the fixed portion, and the track rail is laid on the fixed portion with the bottom surface in contact with the fixed portion.
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  By the way, when the ball rolling groove is machined on the track rail, a machining position error occurs between the actual machining position and the designed machining position. Since this machining position error occurs independently for each rolling groove, when rolling grooves are machined on both the left and right sides of the track rail, the rolling groove located on the right side and the rolling groove located on the left side Relative processing error will occur between the two. This is the same when machining the load rolling groove with respect to the moving block, and a relative machining error is generated between the load rolling grooves located on the left and right of the moving block.

  For this reason, when the relative processing error in the rolling groove of the track rail and the relative processing error in the load rolling groove of the moving block overlap when the moving block is assembled to the track rail, There was a tendency that the mounting surface of the movable body in the block was largely inclined with respect to the bottom surface of the track rail. If the moving block is forcibly fixed to the movable body in this state, a moment load is always applied to the moving block, and the partial wear of the ball is promoted and the life of the linear guide device may be shortened. is there.

  On the other hand, the processing position error of the above-described rolling groove or load rolling groove can be reduced as much as possible by taking time and effort to process the track rail and the moving block. For example, as in the conventional track rail Finally, by finishing the rolling groove by grinding, the inclination of the movable body mounting surface of the moving block can be reduced to a negligible level.

  However, such a processing method is laborious and expensive, and is a major obstacle to reducing the production cost of the linear guide device. Therefore, there is a demand for a linear guide device that can reduce the inclination of the movable body mounting surface of the moving block as much as possible while adopting a simple processing method.

  The present invention has been made in view of such problems, and its object is to provide a pair of rolling grooves formed on the left and right side surfaces of the track rail and a load rolling groove of a moving block opposite to the rolling grooves. Provides a linear guide device that can reduce the inclination of the movable body mounting surface of the moving block and that can be produced easily and inexpensively while advising that relative machining errors are included There is to do.

  In order to achieve the above-mentioned object, the linear guide device of the present invention is provided with a large number of balls and a fixed portion and rolling grooves of the balls are formed on each side surface one by one along the longitudinal direction. A track rail having a horizontal web and a pair of skirts projecting from the horizontal web and having a guide groove, and a mounting surface of a movable body is formed on the horizontal web. On the other hand, the inner side surface of the skirt portion facing the guide groove has a pair of load straight grooves facing the rolling groove of the track rail, and includes a moving block assembled to the track rail via the ball. Has been. The shape of the cross section perpendicular to the longitudinal direction of the track rail is line symmetric with respect to a line segment connecting the centers of the ball rolling grooves located on both side surfaces thereof, and the moving block includes the track rail. Even if the longitudinal direction is turned upside down as the rotation axis, it can be assembled to the track rail.

  For this reason, when the moving block is once assembled to the track rail, the relative machining errors of the ball rolling groove on the right side surface of the track rail and the load straight groove on the right side surface of the moving block are superimposed. When the mounting surface of the movable body in the moving block is greatly inclined with respect to the bottom surface of the track rail, the track rail is turned upside down with its longitudinal direction as the rotation axis, and the moving block is assembled to the track rail again. Thus, the ball rolling groove on the right side surface of the track rail and the load straight groove on the left side surface of the moving block face each other. As a result, relative processing errors cancel each other out, contributing to a reduction in the inclination of the mounting surface of the moving block.

  In addition, when processing the track rail, not only the relative processing error occurs between the ball rolling grooves on the left and right side surfaces of the track rail, but also the processing error occurs by the same distance with respect to the top and bottom surfaces of the track rail. In some cases. The machining error also occurs between the load straight grooves on the left and right side surfaces of the moving block, similarly to the ball rolling grooves of the track rail. Therefore, when the moving block is once assembled to the track rail, if the processing errors of the ball rolling groove of the track rail and the load straight groove of the moving block are superimposed, the track rail is laid. The height from the fixed part to the mounting surface of the moving block varies. Therefore, by turning the track rail upside down with its longitudinal direction as the axis of rotation, and assembling the moving block to the track rail again, the machining errors cancel each other and move from the fixed part where the track rail is laid. The height to the mounting surface of the block can also be adjusted.

  Therefore, according to the linear guide device of the present invention, even when there is a relative machining error in each of the track rail and the moving block, the inclination of the mounting surface of the moving block resulting from the superposition of these relative machining errors is reduced. It can be mitigated. That is, according to the present invention, even if the track rail machining accuracy is low, the inclination of the mounting surface of the moving block can be relaxed. The apparatus can be manufactured easily and inexpensively.

  Furthermore, the fact that the track rail has the above shape means that the track rail has a vertically and horizontally symmetrical shape, so that the track rail is produced using plastic processing such as drawing and cold rolling. Even so, the track rail is less likely to be distorted. That is, according to the linear guide device of the present invention, the track rail is suitable for production by plastic working, and further, the track rail produced by plastic working is ground by the effect of reducing the inclination of the mounting surface of the moving block. It is possible to configure the linear guide device by using it as it is without processing. This also contributes to a reduction in manufacturing cost.

  Hereinafter, the linear guide device of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a first embodiment of a linear guide device to which the present invention is applied. This linear guide device is composed of a long track rail 1 having a substantially rectangular cross section and a moving block 2 which is formed in a channel shape and is assembled to the track rail 1 via a large number of balls 3. The moving block 2 straddles the track rail 1 so as to freely reciprocate on the track rail 1.

  FIG. 2 shows a cross section perpendicular to the longitudinal direction of the linear guide device of the present invention shown in FIG. One rolling groove 10 of the ball 3 is formed on each side surface of the track rail 1 along the longitudinal direction. The rolling grooves 10 are the same distance from the top surface 11 and the bottom surface 12 of the track rail 1. It is formed only at a position apart. Further, a plurality of bolt mounting holes 13 are formed through the track rail 1 at predetermined intervals in the longitudinal direction. The bolt rails 1 are used to connect the track rail 1 to beds or columns of various machines. It can be attached to the fixed portion 4.

  The moving block 2 has a lateral web 20 and a pair of skirt portions 21 orthogonal to the lateral web 20, and is formed in a channel shape, and has a guide groove 22 between the pair of skirt portions 21. . As shown in FIG. 1, the moving block 2 has the upper portion of the track rail 1 loosely fitted in the guide groove 22 and straddles the track rail 1 through a slight gap. That is, both side surfaces of the track rail 1 are opposed to the inner surface of the skirt portion 21 of the moving block 2. The upper surface of the horizontal web 20 is a mounting surface 23 for a movable body such as a table, and the horizontal web 20 has a tap hole 24 into which a mounting screw is screwed. Further, the moving block 2 has a track groove 30 in which the ball 3 circulates infinitely.

  FIG. 3 is a diagram illustrating a state in which the track groove 30 of the moving block 2 is developed on a plane. The track groove 30 is formed on the lateral web 20 in parallel with the load straight groove 31 formed on the inner surface of the skirt portion 21 so as to face the rolling groove 10 of the track rail 1. The unloaded straight groove 32 and the ball deflection groove 33 for moving the ball 3 back and forth between the loaded straight groove 31 and the unloaded straight groove 32. The track groove 30 is open toward the track rail 1 in the entire area, and the balls 3 arranged in the track groove 30 circulate in the track groove 30 while facing the track rail 1. The details of the track groove are also described in WO2008038674A1.

  An unloaded ball guide surface 14a is formed at a position where the upper surface 11 and the side surface of the track rail 1 intersect, and the unloaded ball guide surface 14a has a convex curved surface. The unloaded ball guide surface 14a faces the unloaded straight groove 32 of the track groove. This is to facilitate infinite circulation of the ball 3 in the moving block 2. In addition, as will be described later, in the present invention, the track rail 1 is used in a state where the track rail 1 is turned upside down with the longitudinal direction as the rotation axis, so that the no-load ball guide is also provided at the position where the bottom surface 12 and the side surface of the track rail 1 intersect. An unloaded ball guide surface 14b having the same shape as the surface 14a is formed.

  The ball 3 is transferred while applying a load between the rolling groove 10 of the track rail 1 and the load linear groove 31 of the moving block 2, while entering the ball deflection groove 33 having a substantially U-shaped track. Then, it is released and after reversing its rolling direction, it enters into the unloaded straight groove 32 of the moving block 2. In addition, the ball 3 traveling in the no-load straight groove 32 enters the ball deflection groove 33 on the opposite side and reverses the rolling direction again, and then the load straight line between the rolling groove 10 of the track rail 1 and the moving block 2. As the ball deflection groove 33 gradually becomes shallower as it enters between the groove 31 and the ball deflection groove 33 becomes gradually shallower, the state shifts from the unloaded state to the loaded state.

  The ball 3 circulates in the track groove 30 of the moving block 2 in this way, and accordingly, the moving block 2 can continuously move along the track rail 1 without interruption.

  By the way, when the rolling groove 10 is actually formed on the side surface of the track rail 1, the width direction of the track rail (left and right direction in FIG. 2) and the height direction (FIG. 2) are located at the position where the rolling groove is formed. Machining position errors in the vertical direction of the paper surface).

  FIG. 4 shows a machining position error in the height direction of the rolling groove 10 formed on the track rail 1. For convenience of explanation, in FIG. 4, the rolling groove located on the right side of the track rail is denoted by reference numeral 10 </ b> R, and the rolling groove located on the left side is denoted by reference numeral 10 </ b> L.

  In the processing method used for the linear guide device, in the processing step of the ball rolling groove 10 of the track rail 1, a processing position error occurs between the actual processing position and the designed processing position on the left and right sides. For example, as shown in FIG. 4, the rolling groove 10L on the left side surface of the track rail has an error by a distance X from the design processing position, whereas the rolling groove 10R on the right side has a design error. An error is generated by a distance Y from the machining position. When the machining position error X and the machining position error Y are different, a relative machining error Y-X occurs due to both errors.

  FIG. 5 shows the machining position error in the height direction of the load straight groove 31 formed in the moving block 2. For convenience of explanation, in FIG. 4, reference numeral 31 </ b> R is attached to the rolling groove located on the right side surface of the moving block, and reference numeral 31 </ b> L is attached to the load straight groove located on the left side surface.

  In the moving block 2 as well as the rolling groove 10 of the track rail 1, a machining position error occurs when machining the left and right load straight grooves on both sides, and the design process is performed on the load straight groove 31 </ b> L on the left side. An error is generated by a distance x from the position, and an error is generated by a distance y from the designed machining position in the load straight groove 31R on the right side. When the machining position error x and the machining position error y are different, a relative machining error y-x occurs due to both errors.

  The bottom surface 12 of the track rail 1 is laid on the fixed portion in contact with the fixed portion 4, and the rolling groove 10L of the track rail 1 and the load straight groove 31L of the moving block 2 are balls. 3, when the moving block 2 is assembled to the track rail 1 so as to face each other, the relative processing error YX of the track rail 1 and the relative processing error xy of the moving block 2 are It overlaps on the right side of the linear guide device. In this case, the attachment surface 23 of the moving block 2 is greatly inclined.

  In view of this problem, as shown in FIG. 6, the rolling groove 10 of the ball 3 of the track rail 1 of the present invention is formed at the same distance from the top surface 11 and the bottom surface 12 of the track rail 1. That is, a line segment A connecting the centers of the rolling grooves on both side surfaces is formed, and the distance B from the line segment A to the upper surface 11 is equal to the distance C from the line segment A to the bottom surface 12. . Therefore, it has a line-symmetric shape with respect to the line segment A, and the track rail 1 can be turned upside down with its longitudinal direction as the rotation axis.

  For this reason, as shown in FIG. 7, in a state where the upper surface 11 of the track rail 1 is in contact with the fixed portion 4, that is, in a state where the track rail 1 is turned upside down around its longitudinal direction as a rotation axis, The moving block 2 can be assembled. As a result, the rolling groove 10L of the track rail 1 and the load straight groove 31R of the moving block 2 face each other via the ball 3, while the rolling groove 10R of the track rail 1 and the load straight groove 31L of the moving block 2 are also ball 3 Will face each other. As a result, the relative machining error YX of the track rail 1 and the relative machining error yx of the moving block 2 cancel each other, contributing to the reduction of the inclination of the mounting surface 23 of the moving block 2.

  Therefore, when the linear guide device of the present invention is assembled, the relative machining error YX of the produced track rail 1 and the relative machining error xy of the moving block 2 are individually measured, and these are offset. Thus, if the assembly direction of the track rail 1 with respect to the moving block 2 is selected, the inclination of the mounting surface 23 of the movable body of the moving block 2 can be reduced.

  Further, as described above, the track rail 1 has a line-symmetric shape with respect to the line segment A connecting the centers of the ball rolling grooves 10 on both side surfaces. Since it is arrange | positioned in the same position of a side surface, it will naturally have a left-right symmetric shape. Therefore, distortion hardly occurs during plastic processing such as drawing and cold rolling, and it is possible to provide rolling grooves with a certain degree of processing accuracy on the track rail without using grinding. And by selecting the assembly direction of the moving block with respect to the track rail, the inclination of the movable body mounting surface can be reduced as described above, so the track rail formed by plastic processing can be used in combination with the moving block as it is. is there. That is, according to the present invention, it is possible to reduce the labor for processing the track rail and reduce the production cost of the linear guide device. Further, as described above, as a result of the curved unloaded ball guide surfaces formed at the four corners of the track rail 1, the track rail 1 is suitable for production by plastic working.

1 shows a first embodiment of a linear guide device to which the present invention is applied. The cross section perpendicular | vertical to the longitudinal direction of the linear guide apparatus of this invention is shown. It is a figure which shows a mode that the track groove of the movement block was expand | deployed on the plane. It shows the machining position error in the height direction of the rolling groove formed on the track rail. It shows the machining position error in the height direction of the load straight groove formed in the moving block. The cross section perpendicular | vertical to the longitudinal direction of the track rail of this invention is shown. The track rail of the present invention is shown upside down with the longitudinal direction as the axis of rotation and assembled with the moving block.

Explanation of symbols

1 ... Track rail, 2 ... Moving block, 3 ... Ball, 10 ... Rolling groove, 20 ... Horizontal web, 21 ... Skirt, 23 ... Mounting surface of table etc., 30 ... Track groove, 31 ... Load straight groove , 32 ... No-load straight groove, 33 ... Ball deflection groove

Claims (3)

A large number of balls, a track rail that is laid on the fixed part and has a rolling groove for each ball formed on each side surface along the longitudinal direction, a lateral web, and a lateral web projecting from the lateral web. A channel having a pair of skirt portions and having a guide groove is formed. A mounting surface of a movable body is formed on the horizontal web, while a track is formed on an inner surface of the skirt portion facing the guide groove. It has a pair of load straight grooves facing the rolling grooves of the rail, and is composed of a moving block assembled to the track rail via the balls,
The cross-sectional shape perpendicular to the longitudinal direction of the track rail is axisymmetric with respect to a line segment connecting the centers of the ball rolling grooves located on both side surfaces thereof, and the moving block has the track rail extending in the longitudinal direction. It can be assembled to the track rail even if it is turned upside down with the direction as the axis of rotation .
The linear guide device, wherein the track rail is selectively reversed and assembled to the moving block so that the inclination of the mounting surface of the moving block with respect to the fixed portion becomes small. The linear guide device according to claim 1, wherein the track rail is produced by plastic working. The moving block has a track groove in which the ball circulates and is opened toward the track rail, and the track groove includes the load straight groove and a no-load that is arranged in parallel with the load straight groove. 3. The linear guide device according to claim 1, wherein the linear guide device comprises a straight groove and a pair of ball deflection grooves that connect and connect the loaded straight groove and the unloaded straight groove.

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