JP2009162275A - Movement guide device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an influence that a machining error causes unevenness of load distribution. <P>SOLUTION: A movement guide device 10 has a track rail 11 formed with a rolling element rolling groove 11a along the longitudinal direction, a moving block 21 formed with a load rolling element rolling groove 25 opposite to the rolling element rolling groove 11a, and a plurality of balls 12 provided freely to roll in a load rolling element rolling path 32 structured of the rolling element rolling groove 11a and the load rolling element rolling groove 25, and the moving block 21 can be moved for reciprocation in the longitudinal direction of the track rail 11. The load rolling element rolling path 32 is formed with a group of double-row load rolling element rolling path 36 by arranging two routes of the load rolling element rolling paths 32 and 32 close to each other and in parallel with each other. The double-row rolling element rolling path 36 is structured so that contact angles θ<SB>1</SB>and θ<SB>2</SB>with the ball 12 are different from each other between the two routes of the load rolling element rolling paths 32 and 32 forming a group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motion guide device, and more particularly to a motion guide device that can reduce the influence of non-uniform load distribution due to machining errors.

  2. Description of the Related Art Conventionally, a motion guide device as shown in FIGS. 22 and 23 is known as a machine element part that moves a linear motion portion of a machine lightly and accurately. The configuration of this type of motion guide device will be described with reference to FIGS. 22 and 23. A motion guide device 40 according to the prior art includes a track rail 41 and balls 42 installed on the track rail 41 as a large number of rolling elements. And a moving block 43 that is reciprocally mounted via the... The track rail 41 is a long member whose cross section perpendicular to the longitudinal direction is formed in a substantially rectangular shape, and on its surface (upper surface and both side surfaces), a rolling element rolling groove serving as a track when the ball 42 rolls. 41 a... Are formed over the entire length of the track rail 41. The track rail 41 may be formed to extend linearly or may be formed to extend in a curved manner.

  On the other hand, the moving block 43 includes a moving block main body 43a made of a metal material, and a pair of end plates 43b and 43b made of a resin material installed on both end surfaces in the moving direction of the moving block main body 43a. ing. The moving block body 43a is provided with load rolling element rolling grooves 43c at positions corresponding to the rolling element rolling grooves 41a. The rolling element rolling grooves 41a of the track rail 41 and the loaded rolling element rolling grooves 43c formed in the moving block main body 43a form a loaded rolling element rolling path 52, and a plurality of the rolling element rolling paths 52 introduced into the passage. The balls 42 roll while receiving a load. Further, the moving block main body 43a includes unloaded rolling element rolling paths 53 extending in parallel with the loaded rolling element rolling grooves 43c. Further, each of the pair of end plates 43b, 43b is provided with a direction changing path 55 that connects the unloaded rolling element rolling paths 53 to the loaded rolling element rolling paths 52. One endless circulation path is constituted by a combination of one loaded rolling element rolling path 52 and unloaded rolling element rolling path 53 and a pair of direction changing paths 55, 55 connecting them (see FIG. 23). ).

  A plurality of balls 42 are installed in an infinite circulation path composed of a loaded rolling element rolling path 52, an unloaded rolling element rolling path 53, and a pair of direction changing paths 55, 55 so that infinite circulation is possible. A reciprocating motion of the moving block 43 relative to the track rail 41 is possible.

  By the way, in the recent industry, there is a request to expand the application range of the above-described motion guide device, and for device manufacturers, there is a market for motion guide devices with further improved guidance accuracy. Has been requested to provide. As an example of such a request, for example, there is a case where minimization is required for a change in the posture of a moving block, vibration (pulsation), etc., which is called a waving phenomenon, which has not been a problem in general applications. As a conventional measure for improving this kind of guidance accuracy, for example, in order to move the ball 42 smoothly from the loaded rolling element rolling path 52 which is the load area of the ball in the direction change path 55 which is the no-load area. In addition, efforts have been made to improve the dimensional accuracy of equipment parts by improving the processing technology, or to provide a crowning shape at the entrance of the direction change path 55, and to optimize the crowning shape. .

  However, there is a limit to the improvement from the viewpoint of a slight design change of the existing shape as described above and the optimization of the processing technique, and the creation of a new improvement technique for increasing the accuracy of the motion guide device is required. It was.

  The present invention has been made in view of the above-described problems, and the object thereof is to provide a new and improved technique capable of improving the accuracy of the motion guide device, and thus compared with the conventional technique. Another object of the present invention is to provide a motion guide device that achieves higher accuracy.

  The motion guide device according to the present invention includes a track rail in which rolling element rolling grooves are formed along the longitudinal direction, a moving block in which a loaded rolling element rolling groove facing the rolling element rolling grooves is formed, A plurality of balls installed in a freely rolling manner in a loaded rolling element rolling path constituted by the rolling element rolling groove and the loaded rolling element rolling groove, so that the moving block has the track rail. The load rolling element rolling path is a set of double-row load rolling elements by arranging two load rolling element rolling paths in close proximity and in parallel. It is comprised so that a rolling path may be formed, and the said double-row load rolling element rolling path is comprised so that the contact angle with a ball | bowl may mutually differ in the load rolling element rolling path of 2 path | routes which comprise a pair. And

  In the exercise guide device according to the present invention, the double-row load rolling element rolling path is a load rolling element rolling path of any one of the two paths forming a set according to the direction of the load applied to the exercise guide apparatus. It functions as a main path that mainly receives the load from the ball, and the other rolling rolling element rolling path of the other pair of paths functions as a sub-path that auxiliaryly receives the load from the ball Can be configured.

  In the motion guide device according to the present invention, when the motion guide device receives a load and the ball in the main path is in contact with a gap, the ball in the sub path causes contact fluctuation. Thus, when the gap between the main path and the ball in the main path is eliminated and the ball in the sub path is in contact with a gap, the main path and the ball in the main path cooperate with each other. Thus, the load can be received.

Further, in another motion guide device according to the present invention, the double row rolling element rolling path has a contact angle θ ₁ with the ball in one of the two rolling element rolling paths forming a set, 45 ° <θ ₁ <90 ° is satisfied, and the contact angle θ ₂ with the ball in the other loaded rolling element rolling path of the two paths forming the set is 0 ° <θ ₂ < It can be configured to satisfy the inequality of 45 °.

  In another motion guide device according to the present invention, when the motion guide device receives a load, and the ball in the one loaded rolling element rolling path is in contact with a gap, the other load When the ball in the rolling element rolling path undergoes contact fluctuation, the gap between the one loaded rolling element rolling path and the ball in the one loaded rolling element rolling path is eliminated, and the other loaded rolling element rolling path When the inner ball is in contact with a gap, the one loaded rolling element rolling path and the ball in the one loaded rolling element rolling path cooperate to receive the load. be able to.

  Furthermore, in the motion guide device according to the present invention, it is preferable to provide the load rolling element rolling paths in eight paths.

  Furthermore, in the motion guide apparatus according to the present invention, it is preferable that the plurality of balls are configured with a diameter of 1/10 or less of a rail width of the track rail.

  According to the present invention, it is possible to reduce the influence of non-uniform load distribution due to machining errors, so that it is possible to further improve the accuracy of the infinite circulation path through which a plurality of rolling elements circulate. Thereby, the new motion guidance apparatus which improved the guidance precision compared with the prior art can be provided.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out the invention will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all the combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

  FIG. 1 is a partially broken perspective view for explaining a motion guide apparatus according to the present embodiment. FIG. 2 is a partial longitudinal cross-sectional front view of the motion guide device according to the present embodiment, in which the right side of the drawing shows the appearance and the left side of the drawing shows a cross section perpendicular to the longitudinal direction. Furthermore, FIG. 3 is a partially broken side view of the motion guide apparatus according to the present embodiment. The motion guide device 10 according to this embodiment includes a track rail 11 formed to extend in the longitudinal direction, and a moving block 21 that is assembled to the track rail 11 via a plurality of balls 12 so as to be relatively movable. ing.

  The outline of the members constituting the motion guide device 10 will be described. The track rail 11 is a long member whose cross section perpendicular to the longitudinal direction is formed in a substantially horizontally long rectangle, and its surface (upper surface and both side surfaces). Are formed with a rolling element rolling groove 11a, which becomes a track when the ball 12 rolls, over the entire length of the track rail 11.

  Moreover, about the track rail 11 which concerns on this embodiment, the rolling element rolling groove | channel 11a ... of a total of 8 articles | rows is formed, 4 articles | rows on an upper surface, and 2 articles | strands on both sides. The eight rolling element rolling grooves 11a ... are formed so that the two rolling element rolling grooves 11a, 11a are close to each other and are arranged in parallel so that each two pieces form one set. In particular, for the four rolling element rolling grooves 11a ... formed on the upper surface of the track rail 11, each set is arranged at a position close to both outer sides of the upper surface. A set of two rolling element rolling grooves 11a, 11a brought close to both outer sides of the upper surface, and a set of two rolling element rolling grooves 11a, 11a formed on the side surface close to these sets; Are arranged at corresponding positions across the upper corner of the track rail 11. In the case of the track rail 11 according to the present embodiment, it may be formed in a linear shape as shown in FIG. 1 as in the case of the prior art, or may be curved with a certain curvature. May be formed.

  On the other hand, a total of eight moving blocks 21 (only two are visible in FIG. 1) are installed on the moving block main body 22 made of a metal material and both end surfaces of the moving block main body 22 in the moving direction. The return member 23 includes a pair of end plates 24 and 24 that are attached to both end surfaces of the moving block body 22 in the relative movement direction so as to cover the return member 23.

  Here, FIG. 4 is shown as an external front view for explaining the configuration of the moving block main body 22 according to the present embodiment. As shown in more detail in FIG. 4, the moving block main body 22 according to the present embodiment forms a loaded rolling element rolling path 32 in cooperation with the rolling element rolling groove 11 a formed in the track rail 11. The load rolling element rolling groove 25 is provided on the surface facing the track rail 11 during assembly. Further, a through-hole 26 penetrating in parallel with the load rolling element rolling groove 25 is provided at a position spaced apart from the rolling element rolling groove 25 by a predetermined distance.

  The through hole 26 formed through the moving block main body 22 is for introducing and installing the resin member 27 formed by combining the divided bodies 27a and 27b made of two resin materials (FIG. 1 and FIG. 1). See also FIG. 2). Two grooves constituting a part of the unloaded rolling element rolling path 33 are formed in the first divided body 27 a, while the second divided body 27 b has the no-load rolling element rolling path 33. Two grooves constituting the remaining portion are formed. Then, by forming the resin member 27 by combining the first divided body 27a and the second divided body 27b, the groove described above is combined in the central portion of the resin member 27, whereby two rows of unloaded rolling elements are formed. The rolling paths 33 and 33 are completed.

  Further, as shown in FIG. 2, by introducing and installing the resin member 27 to the through hole 26, it is parallel to the load rolling element rolling path 32 formed by the rolling element rolling groove 11 a and the load rolling element rolling groove 25. The arranged no-load rolling element rolling path 33 will be formed.

  In addition, the no-load rolling element rolling path 33 according to the present embodiment is configured by a set of two rolling roads arranged in close proximity and in parallel in consideration of minimization of a waving phenomenon to be described later. Therefore, the configuration in which two unloaded rolling element rolling paths 33 are formed and introduced into the resin member 27 made of a resin material using the through holes 26 formed through the moving block main body portion 22 is processed. Therefore, it has an effect of being easy and inexpensive, and is a very suitable configuration.

  Next, the configuration of the return member 23 will be described with reference to FIG. 5A and 5B are diagrams for explaining the return member 23 according to the present embodiment. FIG. 5A shows a contact surface with the moving block main body 22 and FIG. 5B shows the moving block main body. The surface standing upright with respect to the attachment surface of the part 22 is shown, (c) has shown the surface adjacent to the surface of (b) in the figure.

  The return member 23 according to the present embodiment is a member that is attached to both end surfaces of the moving block main body 22 in the relative movement direction, and two protrusions are formed on the contact surface of the return member 23 with the moving block main body 22. Is formed. One protrusion formed on the return member 23 is a convex portion 23 a that fits into the concave portion 28 (see FIGS. 2 and 4) formed on the moving block main body portion 22, and the other protrusion formed on the return member 23. The protrusion is a locking projection 23 b that fits into a locking groove 29 (see FIG. 2) having a semi-cylindrical shape formed on the resin member 27. In particular, the positions where the recesses 28 and the projections 23a, the locking grooves 29 and the locking projections 23b are formed are strictly defined, and the installation position of the return member 23 with respect to the movable block main body 22 is extremely high. It is highly accurate. In addition, since the locking groove 29 and the locking projection 23b have a fitting structure using a semi-cylindrical shape, as a detent or positioning of the return member 23 and the resin member 27 with respect to the moving block main body 22 It is possible to exhibit a suitable action.

  Furthermore, the return member 23 according to the present embodiment has an inner peripheral side that connects a part of the loaded rolling element rolling path 32 and a part of the unloaded rolling element rolling path 33 when installed on the moving block main body 22. A direction changing groove 35a is formed. About this inner peripheral side direction change groove | channel 35a, by the effect | action of the recessed part 28 and the convex part 23a, and the latching groove | channel 29 and the latching convex part 23b, a part of load rolling-element rolling path 32 and the unloaded rolling-element rolling path 33 are provided. Since it is possible to communicate with a part of the outer surface side direction change groove 35b formed on the end plate 24 side described later, the load is changed when the direction change path 35 is formed. The connection between the rolling element rolling path 32 and the no-load rolling element rolling path 33 can be realized without a step.

  In addition, the fixed fixing of the return member 23 according to the present embodiment to the moving block main body portion 22 is realized by using a fixing means such as a screw hole formed in the return member 23, for example, to realize a stronger fixed state. Can do.

  Next, the configuration of the end plate 24 according to this embodiment will be described with reference to FIG. The end plate 24 according to the present embodiment is a member that covers and attaches the return member 23 to both end surfaces of the moving block main body 22 in the relative movement direction. The end plate 24 is formed with an outer peripheral side direction changing groove 35b on the mounting surface side with the moving block main body 22, and the outer peripheral side direction changing groove 35b and the inner peripheral side direction changing groove 35a of the return member 23 By cooperating with each other, it is possible to form a direction changing path 35 that connects the loaded rolling element rolling path 32 and the unloaded rolling element rolling path 33. The outer peripheral side direction changing groove 35b formed in the end plate 24 is not required to have the dimensional accuracy as the inner peripheral side direction changing groove 35a of the return member 23, and may be formed with a certain allowance. It is preferable from the viewpoint of facilitating the mounting. The dimensional accuracy of the infinite circulation path is not a problem because strict accuracy is obtained on the inner circumferential side direction changing groove 35a side of the return member 23.

  By assembling the members described above, a loaded rolling element rolling path 32, an unloaded rolling element rolling path 33, and a pair of direction changing paths 35, 35 are formed, and an infinite circulation path formed by these rolling paths is formed. The plurality of balls 12 arranged circulate in the infinite circulation path with the relative movement of the moving block 21 with respect to the track rail 11.

  Here, the rolling element rolling grooves 11a and 11a of the motion guide apparatus 10 according to the present embodiment are configured as a set unit of two rolling grooves that are close and parallel as described above. This is because the purpose is to improve the accuracy of the motion guide device 10 such as minimization of the motion.

  In addition, the ball 12 employed in the present embodiment has a smaller diameter (specifically, a diameter equal to or less than 1/10 of the rail width of the track rail 11) compared to a general motion guide device. Thus, the number of balls 12 installed is increased compared to the motion guide device according to the prior art. The reason for adopting such a configuration is that the number of balls 12 installed in the motion guide device 10 can be increased by “reducing the diameter of the ball”, so that the load or surface pressure per ball is reduced. This is because a significant effect can be obtained. Due to such operational effects, improvement in motion accuracy in the motion guide device 10 (for example, minimization of posture fluctuation and vibration (pulsation) of the moving block 21) is realized.

  Furthermore, “reducing the diameter of the ball” contributes to an increase in the volume of the moving block 21 since the dimensions of the rolling element rolling groove 11a and the no-load rolling element rolling path 33 can be reduced, so that the rigidity of the moving block 21 is improved. From this point, the accuracy improvement of the motion guide apparatus 10 is realized.

  And these knowledge became clear by the original numerical analysis performed in the research institution which this applicant has. Therefore, the details of this unique numerical analysis will be described in detail.

  FIG. 7 shows a coordinate system of the motion guide device defined by numerical analysis. The external load assumed in this numerical analysis is assumed to act on the coordinate origin taken at the center of the motion guide device as shown in FIG. 7, and the waving value at the coordinate origin is calculated. In addition, the analysis is performed focusing on the z-axis direction, that is, the vertical direction waving.

Furthermore, numerical analysis targets five types of model numbers ( ^# 15, ^# 25, ^# 45, ^# 55, ^# 65, each of which indicates the width dimension (unit: mm) of the track rail). The waving value when changing the ball diameter and the loaded rolling element rolling groove length of the moving block to give the optimum crowning shape for each ball diameter and the loaded rolling element rolling groove length of the moving block Is calculated. The external load at this time was a pure radial load of 0.1 C, and the optimum crowning depth was the value of the maximum ball elastic deformation when a pure radial load of 0.1 C was applied without applying crowning. The crowning shape is a straight crowning. The details of the analysis conditions for the numerical analysis are shown in Table 1.

As a result of performing numerical analysis under the above conditions, analysis results as shown in FIGS. 8 to 12 were obtained. Here, FIGS. 8 to 12 show the ball diameters when the load rolling element rolling groove length reference value l _t is changed in each model number ( ^# 15, ^# 25, ^# 45, ^# 55, ^# 65). It is a figure which shows the relationship with a waving value. 8 to 12 exemplify the product series of the conventional motion guide device manufactured and sold by the applicant, and the product A and the product B in FIG. 8 to FIG. Is used as _a reference value by drawing a vertical line segment.

Then, it was found from the numerical analysis results shown in FIGS. 8 to 12, in either the loaded rolling member rolling groove length reference value l _t, as waving value smaller ball diameter decreases the smaller It was to become.

Moreover, in order to grasp the influence by the difference in the external load applied to the motion guide device from obtaining the above knowledge, when model number ^# 25, load rolling element rolling groove length reference value l _t = 100, The relationship between the ball diameter and the waving value when the external load was changed from 0.10 C to 0.50 C was determined. The analysis result is shown in FIG. As can be seen from FIG. 13, it was expected that the greater the external load, the greater the waving value. On the other hand, the ball diameter can be reduced for any external load. It became clear that there was no change in the tendency that the smaller the value, the smaller the waving value.

  As a result of obtaining the above results, the present applicant assumes that an ultra-precise motion guide device having a waving accuracy of 0.01 μm to 0.05 μm, or an ultra-super-precision motion guide device having a waving accuracy of 0.01 μm or less. In order to obtain the optimum ball diameter, the waveform of the numerical analysis results shown in FIGS. 8 to 12 is enlarged, and the relationship between the waving value and the ball diameter when the waving value is 0.05 μm or less is obtained. It was. The results are shown in FIGS.

  From the analysis results shown in FIG. 14 to FIG. 18, the waveform shown in FIG. 14 to FIG. 18 is changed at the portion indicated by the vertical broken line in the figure, and the ball diameter on the left side of this broken line is larger. It was found that the change in the waving value was large (that is, the effect of reducing the ball diameter was large), and the change in the waving value was small on the right side of the broken line (that is, the ball diameter was made smaller than the broken line value). However, there is little effect on the suppression of the waving value).

Further, as understood from the analysis results shown in FIG. 14 to FIG. 18, in the case of model number ^# 15, the waving value is stably reduced when the ball diameter is smaller than 1.5 mm, and in the case of model number ^# 25, the ball diameter is reduced. Is less than 3.0 mm, the waving value is stably reduced. In the case of model ^# 45, the ball diameter is stably reduced when the ball diameter is less than 4.5 mm, and in the case of model ^# 55, the ball diameter is 5 waving value becomes smaller than .7mm decreases stable, in the case of model number ^# 65 waving value when the ball diameter is smaller than 6.5mm may be mentioned that stably reduced.

To summarize this result as the relation between the width of the ball diameter and the track rail, if the model number ^# 15 the change point appears when the diameter of the ball becomes 1/10 of the width of the track rail, model ^# 25 In the case of, the above change point appears when the ball diameter becomes 1 / 8.33 of the track rail width, and in the case of model ^# 45, the ball diameter becomes 1/10 of the track rail width. to the change point appears, model number ^# for 55 the change point appears when the diameter of the ball becomes 1 / 9.65 of the width of the track rail, orbit diameter of the ball in the case of model number ^# 65 rails It became clear that the above change point appeared when the width became 1/10. Moreover, these results show that even when all model numbers are combined, the change point satisfies the waving value of 0.008 μm to 0.002 μm or less, and the ball diameter is 1/10 or less of the width of the track rail. It is shown that if the motion guide device is configured so that an ultra-high precision motion guide device with a waving accuracy of 0.01 μm or less can be realized.

  From the analysis results shown in FIG. 14 to FIG. 18, it is clear that the smaller the lower limit value of the ball diameter is, the smaller the waving value tends to be suppressed. It is expected that the ball diameter is better as long as it is as close to 0 (zero) as possible. However, in view of the current manufacturing technology, the realistic lower limit of the ball diameter can be about 0.7 mm to 0.5 mm.

  Further, the applicant's researchers have conceived that the number L of the infinite circuit is increased as a countermeasure against the reduction of the rated load by reducing the ball diameter, and decided to verify the effect. .

  As a specific verification method, as shown in Table 2 below, the motion guide device of the product series called SNS45, which the applicant has manufactured and sold in the past, is used to reduce the diameter of the conventional SNS45 and SNS45 balls. (In other words, the ball diameter is 1/10 or less of the width of the track rail, and the number of infinitely circulated balls is 4) and the ball is reduced in diameter by SNS45. Three types of products were assumed: the number of balls infinitely circulating was eight. Then, for each type of product, the basic dynamic load rating, the waving value (Waving amplitude), and the radial displacement were calculated by analysis software. The analysis results are shown in Table 2 and FIG. FIG. 19 is a line graph for comparing the analysis results shown in Table 2 for each type.

  As a result, comparing the conventional SNS45 with the SNS SNS ball with a smaller diameter, the SNS45 with a smaller sphere has a reduced waving value and radial displacement (improvement). The dynamic load rating is also decreasing (deteriorating) at the same time, and there is a concern that the guiding ability of the motion guiding device may be reduced.

  However, when the diameter of the ball is reduced by SNS45 and the number of balls that circulate infinitely is eight, the waving value and the radial displacement are further reduced compared to the case where the diameter of the ball of SNS45 is only reduced. Although (improved), the basic dynamic load rating is greatly improved (improved). From this analysis result, the motion guide device of the type combining two features such as “reducing the diameter of the ball” and “a total of 8 rolling element rolling grooves each consisting of 2 pairs” is about the same as the conventional one. It was clarified that a very significant effect of dramatically improving the motion accuracy can be achieved while maintaining the motion guide function (basic dynamic load rating).

  As for the number of balls that circulate infinitely, the number of balls that circulate infinitely is L = 4 × N (N is 2 or more) in consideration of obtaining a balanced and stable motion guide device. It is considered suitable to be configured to be a natural number). However, as long as the realistic value of the number L is satisfied as long as the above formula is satisfied, the number L may be set to 8 as a value assuming an ISO-compliant motion guide device. Would be preferred.

  In summary, the diameter of the ball used in the motion guide device is reduced, specifically, the diameter of the ball is configured to be 1/10 or less of the width of the track rail, thereby minimizing the occurrence of waving. It became clear that we could do it.

  In addition, the number of strips of the infinitely circulating ball is increased. Specifically, the number L of balls is L = 4 × N (N is a natural number of 2 or more), and more preferably L = 8. By configuring as described above, the number of balls used in the motion guide device is increased, and it is possible to prevent a decrease in the rated load which has been a concern due to a reduction in the diameter of the balls. Furthermore, it has also been clarified that the increase in the number of balls is effective in suppressing the occurrence of waving (see FIG. 19).

  Note that “reducing the diameter of the ball” and “increasing the number of strips” lead to an increase in the number of balls installed as described above while maintaining the ISO-compliant moving block length. Therefore, the improvement of motion accuracy through the synergistic effect of “reducing the diameter of the ball” and “increasing the number of strips” and the realization of the request for expansion of the application range by realizing the motion guide device within the standard are realized at the same time Yes.

  As mentioned above, although the main structure of the exercise | movement guide apparatus 10 which can exhibit a suitable effect is demonstrated, the exercise | movement guide apparatus 10 which concerns on this embodiment can show a further significant effect. It has. Therefore, such a significant configuration will be described with reference to FIGS. 20 and 21. FIG.

FIG. 20 is a longitudinal sectional view of the motion guide apparatus 10 according to the present embodiment when viewed in a cross section orthogonal to the longitudinal direction of the track rail 11. As already described above, in the track rail 11 according to the present embodiment, the two rolling element rolling grooves 11a, so that two of each of the eight rolling element rolling grooves 11a. 11a is formed so as to be close and parallel. That is, with respect to the load rolling element rolling path 32 included in the motion guide apparatus 10 according to the present embodiment, two sets of load rolling element rolling paths 32 and 32 are arranged close to each other in parallel, thereby forming one set of double row load rolling paths. A moving body rolling path 36 is formed. And about these four sets of double row load rolling-element rolling paths 36, contact angle (theta) ₁ , (theta) ₂ with the ball | bowl 12 is mutually different in _two load rolling-element rolling paths 32 and 32 which comprise a group. It has the characteristic that it is comprised.

The configuration of the double-row load rolling element rolling path 36 will be described in detail by taking the double-row load rolling element rolling path 36 formed on the right side of the track rail 11 shown in FIG. 20 as an example. In the double row rolling element rolling path 36 formed on the upper right side, the contact angle θ ₁ between the rolling element rolling path 32 and the ball 12 positioned on the center side of the track rail 11 (left side in FIG. 20) and the ball 12 is 60 °. The contact angle θ ₂ between the loaded rolling element rolling path 32 and the ball 12 located outside the track rail 11 (on the right side in FIG. 20) is 30 °. Further, in the double-row load rolling element rolling path 36 formed on the right side surface of the track rail 11, the load rolling element rolling path 32 and the ball 12 positioned on the lower side of the track rail 11 (the lower side in FIG. 20). The contact angle θ ₁ is 60 °, and the contact angle θ ₂ between the load rolling element rolling path 32 located on the upper side of the track rail 11 (the upper side in FIG. 20) and the ball 12 is 30 °. It is configured. Note that two sets of double row rolling element rolling paths 36 formed on the left side (upper left side and left side surface) of the track rail 11 shown in FIG. The load rolling element rolling path 36 and the center perpendicular C of the track rail 11 are formed in line symmetry.

In the motion guide apparatus 10 according to the present embodiment, the two load rolling element rolling paths 32 and 32 that form a pair as described above are configured to have different contact angles θ ₁ and θ ₂ , respectively. An optimum load can be received according to the direction of the load applied to the guide device 10. That is, when a load is applied from the radial direction and the reverse radial direction with respect to motion guide device 10 shown in FIG. 20, of the loaded rolling member rolling passage 32, 32 of two paths, the contact angle θ ₁ = 60 ° The loaded rolling element rolling path 32 on the side formed in this manner functions as a main path that mainly receives the load from the ball 12, and the loaded rolling element rolling path 32 on the side formed at a contact angle θ ₂ = 30 ° Thus, it functions as a sub-path for supplementarily receiving a load from the ball 12. On the other hand, when a load is applied from the horizontal direction, the load rolling element rolling path 32 on the side formed at the contact angle θ ₂ = 30 ° of the _two rolling rolling element rolling paths 32, 32 extends from the ball 12. The load rolling element rolling path 32 on the side formed at the contact angle θ ₁ = 60 ° at this time serves as a main path that mainly accepts the load from the ball 12. It will function as. As described above, in the motion guide apparatus 10 according to the present embodiment, the contact angle with the ball 12 is different between the two load rolling element rolling paths 32 and 32 forming a pair. It is possible to receive an optimum load for a load in any direction applied.

  Moreover, about the said structure which has a different contact angle, the effect that the guidance accuracy fall influence resulting from the process error which exists in the case of the process of the load rolling-element rolling path 32 can be made small can also be exhibited. Can do. Therefore, the principle of this effect will be described with reference to FIG.

  For example, the formation accuracy of the loaded rolling element rolling path 32 is determined depending on the positional accuracy of the rolling element rolling groove 11a and the loaded rolling element rolling groove 25 or the dimensional accuracy of these groove shapes. If the machining error is included in these machinings, the load distribution applied to the motion guide device becomes non-uniform due to the machining error, leading to a reduction in guidance accuracy and a reduction in device life. However, minimizing machining errors and reducing machining costs are contradictory, and there is a limit to the complete elimination of machining errors, so even if machining errors exist, the influence of machining errors should be minimized. The technology which can do was demanded. As a result of earnest efforts, the inventors who have recognized the existence of such a problem are configured such that the contact angle with the ball 12 is different between the two rolling rolling element rolling paths 32, 32 forming the above-described set. By doing so, it has been confirmed that the above-mentioned problems can be solved.

That is, due to the processing error included in the load rolling element rolling path 32, the ball 12 in the main path is in contact with a gap as shown in FIG. Sometimes, if the state of FIG. 21 (a) continues as it is, the load applied to the balls 12 and the loaded rolling element rolling path 32 becomes non-uniform, and problems such as a decrease in guiding accuracy and a decrease in life as described above may occur. Become. However, in the motion guide apparatus 10 according to the present embodiment, when the ball 12 in the main path is in a contact state with a gap, the ball 12 in the sub path changes in contact as shown in FIG. As a result, the gap between the main path and the ball 12 in the main path is eliminated, and an appropriate contact state is realized. Such an action is realized because the _two load rolling element rolling paths 32 and 32 arranged close to each other in parallel have different contact angles θ ₁ and θ ₂ . This is a significant effect based on a new configuration that is not found in the prior art.

  On the other hand, when the balls 12 in the sub path are in contact with a gap, the main path and the balls 12 in the main path cooperate to appropriately receive the load. That is, regarding the machining error included in the sub route, the rated load of the motion guide device 10 originally depends on the main route, and therefore the influence of the machining error remains small in this case.

Note that the combination of the contact angles θ ₁ and θ ₂ illustrated in FIGS. 20 and 21 is θ ₁ = 60 ° and θ ₂ = 30 °. Is possible. For example, combinations such as θ ₁ = 50 °, θ ₂ = 40 °, θ ₁ = 55 °, θ ₂ = 35 ° are possible, and the present inventors have made diligent efforts to double-row load rolling elements of the present invention. The rolling path is configured so that the contact angle θ ₁ with the ball on one of the two rolling elements rolling path of the set satisfies the inequality 45 ° <θ ₁ <90 °, and the set Confirm that the contact angle θ ₂ with the ball in the other loaded rolling element rolling path of the two paths forming the above can be configured to satisfy the inequality of 0 ° <θ ₂ <45 °. Yes.

  As mentioned above, although preferred embodiment of this invention was described, the technical scope of this invention is not limited to the range as described in the said embodiment. For example, the shape of the above-described embodiment shows one application example of the present invention, and various changes or improvements can be added within a range having a configuration capable of exhibiting the above-described effects. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

It is a partially broken perspective view for demonstrating the exercise | movement guide apparatus which concerns on this embodiment. It is a partial longitudinal cross-section front view of the exercise | movement guide apparatus which concerns on this embodiment, the paper surface right side shows an external appearance, and the paper surface left side has shown the cross section orthogonal to a longitudinal direction. It is a partially broken side view of the motion guide device according to the present embodiment. It is an external appearance front view for demonstrating the structure of the movement block main-body part which concerns on this embodiment. It is a figure for demonstrating the return member which concerns on this embodiment, (a) shows a contact surface with a movement block main-body part, and (b) is perpendicular | vertical with respect to the attachment surface of a movement block main-body part in the figure. (C) shows a surface adjacent to the surface (b). It is a figure for demonstrating the structure of the end plate which concerns on this embodiment. It is a figure which shows the coordinate system of the linear motion guide device defined by the numerical analysis. It is a diagram showing the relationship between the ball diameter and the waving value when changing the loaded rolling member rolling groove length reference value l _t in model number ^# 15. It is a diagram showing the relationship between the ball diameter and the waving value when changing the loaded rolling member rolling groove length reference value l _t in model number ^# 25. It is a diagram showing the relationship between the ball diameter and the waving value when changing the loaded rolling member rolling groove length reference value l _t in model number ^# 45. It is a diagram showing the relationship between the ball diameter and the waving value when changing the loaded rolling member rolling groove length reference value l _t in model number ^# 55. It is a diagram showing the relationship between the ball diameter and the waving value when changing the loaded rolling member rolling groove length reference value l _t in model number ^# 65. FIG. 11 is a diagram showing the relationship between the ball diameter and the waving value when the external load is changed from 0.10 C to 0.50 C when the model number ^# 25 and the loaded rolling element rolling groove length reference value l _t = 100. is there. It is the figure which clarified the relationship between the further waving value and a ball diameter by expanding the waveform of the numerical analysis result shown in FIG. It is the figure which clarified the relationship between the further waving value and a ball diameter by expanding the waveform of the numerical analysis result shown in FIG. It is the figure which clarified the relationship between the further waving value and a ball diameter by expanding the waveform of the numerical analysis result shown in FIG. It is the figure which clarified the relationship between the further waving value and a ball diameter by expanding the waveform of the numerical analysis result shown in FIG. It is the figure which clarified the relationship between the further waving value and a ball diameter by expanding the waveform of the numerical analysis result shown in FIG. It is the figure represented with the line graph in order to compare the analysis result shown in Table 2 for every type. It is a longitudinal cross-sectional view at the time of seeing the exercise | movement guide apparatus which concerns on this embodiment in the cross section orthogonal to the longitudinal direction of a track rail. It is a figure for demonstrating the principle of the effect which the exercise | movement guide apparatus which concerns on this embodiment can exhibit. It is an external appearance perspective view which illustrates one form of the motion guidance apparatus which concerns on a prior art. It is sectional drawing for demonstrating the infinite circuit provided with the exercise | movement guide apparatus based on the prior art shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Motion guide apparatus, 11 Track rail, 11a Rolling body rolling groove, 12 Ball, 21 Moving block, 22 Moving block main-body part, 23 Return member, 23a Convex part, 23b Locking convex part, 24 End plate, 25 Load rolling Moving body rolling groove, 26 through-hole, 27 resin member, 27a, 27b divided body, 28 recess, 29 locking groove, 32 loaded rolling element rolling path, 33 no-load rolling element rolling path, 35a inner circumferential side direction changing groove, 35b Outer peripheral side direction change groove, 36 Double row load rolling element rolling path, 40 Motion guide device according to prior art, 41 Track rail, 41a Rolling element rolling groove, 42 Ball, 43 Moving block, 43a Moving block main body, 43b End plate, 43c loaded rolling element rolling groove, 52 loaded rolling element rolling path, 53 unloaded rolling element rolling path, 55 direction turning path.

Claims (7)

A track rail in which rolling element rolling grooves are formed along the longitudinal direction;
A moving block in which a loaded rolling element rolling groove facing the rolling element rolling groove is formed;
A plurality of balls installed in a freely rolling manner in a loaded rolling element rolling path constituted by the rolling element rolling groove and the loaded rolling element rolling groove;
A moving guide device in which the moving block is reciprocally movable in the longitudinal direction of the track rail,
The load rolling element rolling path is configured to form a set of double-row load rolling element rolling paths by arranging two load rolling element rolling paths in close proximity and in parallel.
The double row load rolling element rolling path is configured so that the contact angles with the ball are different from each other between the two load rolling element rolling paths forming a set. The motion guide device according to claim 1,
According to the direction of the load applied to the motion guide device, the double row load rolling element rolling path,
The load rolling element rolling path of either one of the two paths forming a set functions as a main path that mainly receives a load from the ball,
One of the two paths forming a set, the other loaded rolling element rolling path functions as a sub-path that supplementarily receives a load from the ball. The motion guide apparatus according to claim 2,
When the motion guide device receives a load,
When the ball in the main path is in a contact state with a gap, the gap between the main path and the ball in the main path is eliminated by causing contact variation of the ball in the sub path,
When the balls in the sub path are in contact with a gap, the main path and the balls in the main path cooperate to receive the load. The motion guide device according to claim 1,
The double row rolling element rolling path is
The contact angle θ ₁ with the ball in any one of the two rolling paths that form a set is configured to satisfy an inequality of 45 ° <θ ₁ <90 °,
The motion characterized in that the contact angle θ ₂ with the ball in the other loaded rolling element rolling path of the two paths forming the set satisfies the inequality of 0 ° <θ ₂ <45 °. Guide device. The motion guide apparatus according to claim 4,
When the motion guide device receives a load,
When the ball in the one rolling rolling element rolling path is in contact with a gap, the ball in the other rolling rolling element rolling path causes contact fluctuations and the one rolling rolling element rolling path The gap with the ball in one of the rolling elements rolling path is eliminated,
When the ball in the other rolling element rolling path is in contact with a gap, the one loaded rolling element rolling path and the ball in the one loaded rolling element rolling path cooperate to A motion guide device characterized by receiving a load. In the exercise | movement guide apparatus of any one of Claims 1-5,
8. An exercise guide apparatus characterized in that eight load rolling element rolling paths are provided. In the exercise | movement guide apparatus of any one of Claims 1-6,
The motion guide device, wherein the plurality of balls are configured with a diameter of 1/10 or less of a rail width of the track rail.

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