JP2012192461A - Hybrid guide apparatus for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid guide apparatus capable of compensating for a defect of a rolling guide that machining ability deteriorates due to vibration caused during the machining and a defect of a slide guide that machining ability deteriorates due to a large difference between a coefficient of kinetic friction and a coefficient of static friction.SOLUTION: The problem is solved by the guide apparatus for a machine tool including: a guide unit for supporting a machining table; a guide rail inserted into the guide unit which has a guide surface extending along the guide rail; and a pressing means having a sliding guide surface that projects from a position apart from the guide surface to a position for pressing the guide surface and can press the guide surface to the machining table.

Description

  The present invention relates to a guide device used in a machine tool. In particular, the present invention relates to a hybrid machine tool guide device in which a rolling guide and a sliding guide are combined.

  A conventional machine tool guide device will be described. The machine tool guide device reduces friction during sliding. Generally, a rolling guide or a sliding guide is common as a guide device for machine tools.

  A conventional rolling guide device for machine tools will be described in detail with reference to FIGS. 5A and 5B. FIG. 5A shows a conventional rolling guide device for machine tools. FIG. 5B shows an enlarged cross section of the one-dot chain line portion 5B of the guide rail 53 in FIG. 5A. A work table (hereinafter referred to as “table”) 51 straddles the guide rails 53, 54 on two guide rails 53, 54 arranged horizontally and in parallel on a bed 50 installed in a base (not shown). Installed. Guide units 52a and 52b are attached to the table 51 on the guide rail 53 side. The same applies to the other guide rail 54. The guide unit 52a will be described as a representative example with reference to FIG. 5B. The same applies to the other guide units. As shown in FIG. 5B, the guide unit 52a is inserted into the guide rail 53. The table 51 can slide on the guide rail 53 while maintaining the set posture. Therefore, the position where the guide unit 52a and the guide unit 52b are attached so as to have an optimal balance is determined according to the size and weight of the table 51. For example, with respect to one guide rail 53, the guide unit 52a and the guide unit 52a are arranged so as to be targeted with respect to the longitudinal center line of the table 51 along the longitudinal direction of the guide rail 53 in a state where the table 51 is placed. A guide unit 52b is arranged. A guide unit is similarly arranged on the other guide rail 54 side. Although not shown in FIGS. 5A to 5B, a ball screw is disposed along the guide rails 53 and 54 at the lower portion of the table 51, so that the table 51 slides along the guide rails 53 and 54. .

  The guide unit 52a will be described with reference to FIG. 5B. As shown in FIG. 5B, a predetermined annular groove is formed in the guide unit 52a. In this annular groove, a plurality of rolling elements are continuously arranged in a chain, and constitute rolling element rows 55a and 55b. Examples of the rolling element include a roller (cylindrical body) or a rolling element (sphere). Various arrangements of the annular grooves are possible. For example, in the example of FIG. 5B, the surface formed by the rolling element group of the rolling element row 55a and the surface formed by the rolling element group of the rolling element row 55b intersect at a certain angle. An annular groove is drilled. Both side surfaces of the guide rail 53 constitute recessed side surfaces that are recessed over the entire longitudinal direction of the guide rail 53. For example, a sliding surface 53 a and a sliding surface 53 b along the longitudinal direction of the guide rail 53 are provided on one hollow side surface. The annular groove on the sliding surface 53a side and the annular groove on the sliding surface 53b side are opened on the sliding surface 53a side and the sliding surface 53b side, and the rolling element groups of the respective rolling element rows 55a and 55b are exposed. Yes. Thereby, the rolling element group of rolling element row | line | column 55a, 55b can contact the sliding surface 53a and the sliding surface 53b, respectively. With this configuration, when the guide unit 52a is moved along the guide rail 53, the rolling element group of the rolling element row 55a moves and circulates in the annular groove while rolling on the sliding surface 53a. Similarly, the rolling element group of the rolling element row 55b moves while circulating in the annular groove while rolling on the sliding surface 53b. By rolling the rolling element rows 55a and 55b on the sliding surface 53a and the sliding surface 53b, the guide unit 52a can move relatively smoothly with respect to the guide rail 53.

  Similarly, the other hollow side surface of the guide rail 53 is provided with a sliding surface 53a and a sliding surface 53b along the longitudinal direction of the guide rail 53, and a sliding surface 53c and a sliding surface 53d. . An annular groove and a rolling element row are also arranged on the sliding surface 53c and the guide unit 52a on the sliding surface 53d side (not shown).

  Next, a conventional machine tool slide guide will be described with reference to FIG. 6A. FIG. 6A shows a conventional slide guide for a machine tool. FIG. 6B shows a cross-section 6B-6B of the guide rail 56 portion in FIG. 6A. Similar to the rolling guide, the table 51 is placed on two parallel guide rails 56 and 57 installed horizontally on a bed 50 installed on a base (not shown). The guide rails 56 and 57 have projecting portions 56a and 57a that project from the guide rail width, respectively. On the table 51 on the side of one guide rail 56, an extending portion 58a is disposed so as to wrap around the protruding portion 56a of the guide rail 56. An extension part 58 b is arranged on the table 51 on the other guide rail 57 side so as to wrap around the extension part 57 a of the guide rail 57. An overhanging portion 56 a is sandwiched between the surface of the table 51 and the extending portion 58 a of the table, and an overhanging portion 57 a is sandwiched between the surface of the table 51 and the extending portion 58 b of the table 51.

  The surface of the guide surface 56b on the side of the guide rail 56 that comes into contact with the table 51 is quenched and polished to reduce the frictional force when the table 51 slides.

  On the other hand, a polyester-based plastic resin plate is attached to the guide surface 51a on the table 51 side facing the guide surface 56b on the guide rail 56 side, and the resin surface on the side that contacts the guide surface 56b on the guide rail 56 side. The surface is scraped. The same processing is performed on the contact surface between the projecting portion 56a of the guide rail 56 and the table 51 and the contact surface between the projecting portion 56a and the extending portion 58b of the guide rail 56. Thereby, the table 51 can move relatively smoothly with respect to the guide rails 56 and 57.

Comparing the performance of the rolling guide and the sliding guide, the sliding guide is vulnerable to high-speed movement and the manufacturing cost is high. In addition, the positioning accuracy is inferior to that of rolling guides.In particular, the difference between the coefficient of static friction at the start of movement and the coefficient of dynamic friction at the time of movement is large. is there.
On the other hand, the rolling guide is suitable for high-speed movement, has good positioning accuracy, and is low in manufacturing cost. However, the rolling guide has a lower damping performance at the time of cutting than the sliding guide, and the cutting accuracy of the rolling guide as a whole is worse than that of the sliding guide. For this reason, for example, as shown in Patent Document 1 and Patent Document 2, a machine tool using a hybrid guide device in which a rolling guide and a sliding guide are combined has been proposed.

JP 2003-326430 A Japanese Patent Application Laid-Open No. 2004-421869 Japanese Patent No. 4218831

  However, in the conventional hybrid type guide device in which the rolling guide and the sliding guide are combined, the switching operation between the rolling guide and the sliding guide is complicated. For example, in Patent Document 1, the specifications of a rolling guide and a sliding guide are switched by attaching and removing a block member having a sliding guide surface. Moreover, in patent document 2, it does not switch a rolling guide and a sliding guide arbitrarily.

In particular, in recent years, a technology that reduces the frictional force by applying a diamond-like carbon (hereinafter referred to as “DLC”) film on the sliding surface in various fields has been popular. Expectation is high as a guide surface treatment. For example, as described in Patent Document 3, when the DLC film coating process is performed on the guide surface of the machine tool, the friction coefficient of the guide surface is improved and the positioning accuracy is improved.
Therefore, a hybrid type guide device that can utilize the advantages of the rolling guide and the sliding guide is desired.

  A guide unit that supports the work table; a guide rail that is inserted into the guide unit, the guide rail including a guide surface that extends along the guide rail; and the guide that is spaced from the guide surface. This is solved by a guide device for a machine tool that includes a pressing means having a sliding guide surface that protrudes to a position for pressing the surface and can press the guide surface against the work table.

  According to the present invention, the advantages of the rolling guide and the sliding guide can be exhibited according to the object to be cut and the cutting situation.

It is a perspective view of the hybrid type guide device of a first embodiment in the present invention. It is sectional drawing which looked at the hybrid type guide apparatus of 1st embodiment in this invention from the direction along a guide rail. It is sectional drawing which looked at the hybrid type guide apparatus of 1st embodiment in this invention from the direction perpendicular | vertical to a guide rail. It is sectional drawing of the guide unit part of the hybrid type guide apparatus of 1st embodiment in the cross section 2A-2A part of FIG. 1C, Comprising: It is a figure at the time of using the rolling guide. It is sectional drawing of the guide unit part of the hybrid type guide apparatus of 1st embodiment in the cross section 2A-2A part of FIG. 1C, Comprising: It is a figure in the case of using a rolling guide and a sliding guide together. It is a perspective view of the hybrid type guide apparatus of 2nd embodiment in this invention. It is the figure which showed the hybrid type guide apparatus of 2nd embodiment in this invention from the direction perpendicular | vertical to a guide rail. It is the figure which showed the hybrid type guide apparatus of 3rd embodiment in this invention. It is a perspective view of the conventional rolling guide apparatus. It is sectional drawing of the guide unit part of the conventional rolling guide apparatus. It is a perspective view of the conventional sliding guide apparatus. It is sectional drawing of the guide unit part of the conventional sliding guide apparatus.

Hereinafter, a hybrid guide device 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1A to 1C and FIGS. 2A to 2B.
(First embodiment)
FIG. 1 shows a hybrid guide device 1 according to a first embodiment of the present invention. FIG. 1B is a diagram showing a cross section 1B-1B in FIG. 1, and FIG. 1C is a diagram viewed from the arrow 1C-1C in FIG. 1A. The guide device 1 includes guide rails 3 and 4, pressing means 5 and 6, and guide units 9, 10, 11, and 12.

  The guide rails 3 and 4 are horizontally arranged on a bed 20 installed on a base (not shown). The guide rail 4 is disposed in parallel to the guide rail 3. The guide rails 3 and 4 are provided with a guide surface 3 a and a guide surface 4 a extending along the guide rail 3 and the guide rail 4, respectively. In the present embodiment, the guide surface 3a and the guide surface 4a are upper surfaces that are parallel to the bed 20 and horizontal among the surfaces of the guide rails 3 and 4, but are not limited thereto.

  The guide units 9, 10, 11, and 12 support the table 2 and are fixed to the table 2 in order to slide the table 2 along the guide rails 3 and 4. The guide units 9 and 10 are inserted into the guide rail 3, and the guide units 11 and 12 are inserted into the guide rail 4. In the guide units 9, 10 and 11, 12, the table 2 is arranged across the guide rails 3 and 4, respectively. Although not shown in FIGS. 1A to 1C, ball screws are arranged along the guide rails 3 and 4 at the lower part of the table 2, so that the table 2 slides along the guide rails 3 and 4.

  For example, as shown in FIG. 1C, the pressing means 5 is disposed between the guide unit 9 and the guide unit 10 on the guide rail 3 side, and is fixed to the table 2. The other pressing means 6 is disposed between the guide unit 11 and the guide unit 12 on the guide rail 4 side. The pressing means 5 and the pressing means 6 include a guide means 7 and a guide means 8, respectively. Each of the guide means 7 and the guide means 8 includes a sliding guide surface 7a and a sliding guide surface 8a at the tip. The sliding guide surface 7a and the sliding guide surface 8a are opposed to the guide surface 3a of the guide rail 3 and the guide surface 4a of the guide rail 4, respectively.

  The sliding guide surface 7a of the guide means 7 protrudes from a retracted position away from the guide surface 3a of the guide rail 3 to a pressing position that presses the guide surface 3a of the guide rail 3, and can press the guide surface 3a of the guide rail 3. It is. On the other hand, the sliding guide surface 8a of the guide means 8 protrudes from a retracted position separated from the guide surface 4a of the guide rail 4 to a pressing position that presses the guide surface 4a of the guide rail 4 so that the guide surface 4a of the guide rail 4 is It can be pressed. As the pressing means 5 and the pressing means 6, for example, a hydraulic cylinder can be typically applied. The pressing means 5 extends the guide means 7 in the normal direction of the guide surface 3a and in the direction of gravity, so that the guide surface 3a is separated from the guide unit 9 (or 10). 7a presses the guide surface 3a. Similarly, the pressing means 6 extends the guide means 8 in the direction normal to the guide surface 4a of the guide rail 4 and in the direction of gravity so that the guide surface 4a is separated from the guide unit 11 (or 12). The sliding guide surface 8a of the guide means 8 presses the guide surface 4a.

  The sliding guide surface 7a and the sliding guide surface 8a are coated with a DLC film. For example, a DLC film having an amorphous structure mainly composed of carbon is coated. Further, a nitride diffusion layer is formed on the surfaces of the sliding guide surfaces 7a and 8a made of chromium molybdenum steel by radical nitridation, and nitride such as chromium nitride formed on the nitrogen diffusion layer by PVD sputtering. It is also conceivable to coat a DLC film on this film.

  The operation of the guide means 7, the guide means 8, the pressing means 5, and the pressing means 6 and the relationship between the guide units 9, 10, 11, 12 will be described in detail. As an example, with reference to FIG. 2A and FIG. 2B, attention is paid to the guide unit 9 inserted in the guide rail 3, and the relationship with the guide means 7 will be described. The same applies to the other guide units 10, 11, 12 and the guide means 8. FIG. 2A is a diagram showing a cross section 2A-2A of FIG. 1C. FIG. 2A shows the guide unit 9 with the sliding guide surface 7a in the retracted position, and FIG. 2B shows the guide unit 9 with the sliding guide surface 7a in the pressing position.

  The guide rail 3 is inserted into the guide unit 9. The first side surface of the guide rail 3 includes a first sliding surface 3b extending along the guide rail 3 at a constant angle with respect to the guide surface 3a of the guide rail 3, and a first sliding surface. And a second sliding surface 3c extending along the guide rail 3 at a constant angle with respect to 3b. On the other second side surface, an angle formed with respect to the guide surface 3a is constant, and a third sliding surface 3d extending along the guide rail 3 and an angle formed with respect to the third sliding surface 3d And a fourth sliding surface 3 e extending along the guide rail 3. The first sliding surface 3b and the third sliding surface 3d are line symmetric with respect to the normal line of the guide surface 3a. The second sliding surface 3c and the fourth sliding surface 3e are line symmetric with respect to the normal line of the guide surface 3a.

  Similar to a conventional rolling guide, the guide unit 9 has an annular groove formed therein. In the case of the present embodiment, an annular groove 9 a and an annular groove 9 b are formed in the guide unit 9 on the first side surface side of the guide rail 3, and the guide unit 9 on the second side surface side of the guide rail 3. An annular groove 9c and an annular groove 9d are formed in the inner surface. The annular groove 9a has a surface formed by the annular groove 9a perpendicular to the first sliding surface 3b, and the annular groove 9b has a surface formed by the annular groove 9b perpendicular to the second sliding surface 3c. It is perforated. The annular groove 9c has a surface formed by the annular groove 9c perpendicular to the third sliding surface 3d, and the annular groove 9d has a surface formed by the annular groove 9d perpendicular to the fourth sliding surface 3e. It is perforated.

  In each of the annular groove 9a, the annular groove 9b, the annular groove 9c, and the annular groove 9d of the guide unit 9, a plurality of rolling elements form a row to form a rolling element group as in the conventional rolling guide. The guide unit 9 slides along the guide rail 3. Each of the annular groove 9a and the annular groove 9b has a first rolling element group row that rolls on the first sliding surface 3b and a second rolling element group row that rolls on the second sliding surface 3c. ing. Similarly, in each of the annular groove 9c and the annular groove 9d, a third rolling element group row rolling on the third sliding surface 3d and a fourth rolling element group row rolling on the fourth sliding surface 3e are provided. have. In the guide unit 9, the annular groove 9a, the annular groove 9b, the annular groove 9c, and the annular groove 9d have openings on the guide rail 3 side. Of the rolling elements in each of the rolling element groups arranged in the annular groove 9a, the annular groove 9b, the annular groove 9c, and the annular groove 9d, the rolling elements 13a, 13b, 13c, and 13d (respectively, located on the guide rail 3 side). From the opening, each of the plurality is in contact with the first sliding surface 3b, the second sliding surface 3c, the third sliding surface 3d, and the fourth sliding surface 3e, and can roll.

  In the case of the present embodiment, the first sliding surface 3b and the second sliding surface 3c constitute a hollow surface on the first side surface of the guide rail 3, and the third sliding surface 3d and the fourth sliding surface. 3e forms a recessed surface on the second side surface, which is the other side surface of the guide rail 3. A preload is applied to the rolling element group row in the guide unit 9. The rolling element 13a has a force component in a direction that pushes up the first sliding surface 3b and the rolling element 13c pushes up the third sliding surface 3d, and the rolling element 13b of each rolling element group row in the guide unit 9 has this preload. Balances the second sliding surface 3c and the rolling element 13d with a force component in a direction to push down the fourth sliding surface 3e. The relationship between the guide rail 3 and the guide unit 10 and the relationship between the guide rail 4 and the guide units 11 and 12 are the same.

  The guide rail 3 and the guide rail 4 receive a load from the table 2 through the guide units 9, 10, 11, and 12. The load load corresponds to the weight of the table 2 and the weight of the machine tool part. The load load from the table 2 is apportioned by the number of guide rails, and the load is apportioned by the number of guide units inserted into the guide rails in each guide rail. In the state of FIG. 2A in which the pressing means 5 is not driven and the sliding guide surface 7a of the guide means 7 is not in contact with the guide surface 3a of the guide rail 3, each of the rolling elements 13a, 13b, 13c, 13d and the first The following load relationships occur between the sliding surface 3b, the second sliding surface 3c, the third sliding surface 3d, and the fourth sliding surface 3e.

  The guide unit 9 is pressed against the guide rail 3 with a load apportioned to the guide unit 9 by the load from the table 2. Since the load is received by the second sliding surface 3c and the fourth sliding surface 3e via the rolling elements 13b and 13d, the guide unit 9 has a direction of the load apportioned to the guide unit 9 (in FIG. 2A). (Downward direction) The preload of the rolling elements 13a and 13c on the first sliding surface 3b and the third sliding surface 3d decreases, and the preload of the rolling elements 13b and 13d on the second sliding surface 3c and the fourth sliding surface 3e increases. To do. Thus, when the load from the table 2 is taken into consideration, the preload of the rolling element group that has been balanced in each guide unit inserted and fitted into all the guide rails is the total guide unit from the table 2. A load imbalance is caused by the load.

Therefore, in order to eliminate this load imbalance state, the pressing means 5 is driven as shown in FIG. 2B. When the pressing means 5 is driven, the sliding guide surface 7a of the guide means 7 contacts the guide surface 3a of the guide rail 3 and presses the guide surface 3a. As a result, in the guide unit 9, the rolling element group generated by the load from the table 2, the first sliding surface 3 b, the second sliding surface 3 c, the third sliding surface 3 d, and the fourth sliding surface. The state of load imbalance 3e is eliminated, and the preload from each rolling element group to the first sliding surface 3b, the second sliding surface 3c, the third sliding surface 3d, and the fourth sliding surface 3e is balanced. Return to the state. In order to eliminate the load imbalance state, the pressing force when the sliding guide surface 7a of the guide means 7 contacts the guide surface 3a of the guide rail 3 and presses the guide surface 3a is equal to the load applied from the table 2. Correspondingly, the load that is apportioned and loaded on one guide rail (for example, guide rail 3) substantially corresponds to the load that is apportioned to the load from the table 2 by the number of pressing means arranged on the guide rail. For example, the description will be given with reference to the example of FIG. In FIG. 1A, the table 2 is supported by two guide rails 3 and a guide rail 4. In one guide rail 3, one pressing means 5 is arranged. If the load of the table portion 2 is M kilograms, the load apportioned to the guide rail 3 is M / 2 kilograms. Therefore, the force to be pressed by driving the pressing means 5 to press the sliding guide surface 7a of the guide means 7 against the guide surface 3a of the guide rail 3 is M / 2 kilograms. If two pressing means are arranged on the guide rail 3, the load to be apportioned is half of that, and the sliding guide surface 7 a of the guide means 7 should be pressed against the guide surface 3 a of the guide rail 3. The force is M / 4 kilograms. However, in practice, since the load load from the table 2 is not uniform, the pressing force (predetermined pressing force) when each pressing means contacts each guide surface of the guide rail and presses each guide surface is the load load. Will be distributed in consideration.
Further, when the guide rail 3 is inclined, the pressing force by which the sliding guide surface 7a of the guide means 7 presses the guide surface 3a of the guide rail 3 by the pressing means 5 is actually applied in a direction perpendicular to the guide surface 3a. This corresponds to the load (the load in the normal direction of the guide surface 3a).

  Next, how to use the guide device 1 of the present invention will be described. When the table 2 is slid along the guide rails 3 and 4 to a predetermined position when not in the cutting state, the guide means 7 and 8 are retracted without driving the pressing means 5 and the pressing means 6. The table 2 is moved while being stored in the position.

  In a state where the table 2 is moved while performing processing such as cutting, the pressing means 5 is driven to project the guide means 7 to the pressing position, and the sliding guide surface 7 a of the guide means 7 is guided to the guide surface of the guide rail 3. Press 3a. The pressing means 5 includes a pressing force applied to the first sliding surface 3b from the rolling elements 13a of the first rolling element group row (a force in consideration of a load caused by its own weight and a preload), and a second Sliding guide surface with a load that eliminates the load imbalance between the pressing force applied to the second sliding surface 3c from the rolling elements 13b of the rolling element group row (the load caused by its own weight and the force considering the preload). In a state where 7a is pressed against the guide surface 3a, the guide unit 9 slides along the guide rail 3 while the sliding guide surface 7a slides on the guide surface 3a.

  Similarly, the pressing means 5 includes a pressing force applied to the third sliding surface 3d from the rolling elements 13c of the third rolling element group row (a load in consideration of a load caused by its own weight and a preload), and The pressing force applied to the fourth sliding surface 3e from the rolling elements 13d of the fourth rolling element group row (the load caused by its own weight and the force considering the preload) is balanced and is a load that provides appropriate friction. The sliding guide surface 7a is pressed against the guide surface 3a. In this state, the guide unit 9 slides along the guide rail 3 while the sliding guide surface 7a slides on the guide surface 3a. The same applies to the pressing means 6 in the other guide rail 4. Actually, the center of gravity position on the table 2 is not necessarily at the center of the table 2, so that a moment is received by the eccentricity of the center of gravity. The pressing force for pressing the sliding guide surface 7a against the guide surface 3a by the pressing means 5 is adjusted in consideration of this moment.

By pressing the sliding guide surface by the pressing means, the preload state of the rolling guide returns to a balanced state. Thereby, the difference of the dynamic friction coefficient of a rolling guide itself and a static friction coefficient can be made small. Further, it is possible to use a rolling guide and a sliding guide in combination, and the difference between the dynamic friction coefficient and the static friction coefficient can be reduced even when only the sliding guide is used. Further, by applying the DLC film coating to the sliding surface of the sliding guide, there is almost no difference between the dynamic friction coefficient and the static friction coefficient, and a particularly great effect is achieved.
In other words, the difference between the dynamic friction coefficient and the static friction coefficient is compensated for by the hybrid guide that uses both the rolling guide and the DLC-coated sliding guide because the difference between the dynamic friction coefficient and the static friction coefficient is large and the machining accuracy is low. The processing accuracy can be increased by reducing the size. In addition, the hybrid guide can compensate for the disadvantage of the rolling guide that vibration is likely to occur during processing. In particular, in circular arc cutting, processing with high roundness is possible.

  In the present embodiment, as described above, the guide unit 9 and the guide unit 10 which are two guide units with respect to one guide rail 3, and the pressing means 5 are arranged between the guide unit 9 and the guide unit 10. The form to be described was explained. However, the same effect can be produced with one guide unit 9 and one pressing means 5.

(Second embodiment)
Next, a hybrid guide device according to a second embodiment of the present invention will be described with reference to FIGS. 3A and 3B. FIG. 3A is a perspective view of the hybrid guide device according to the second embodiment of the present invention, and FIG. 3B is a cross-sectional view of the hybrid guide device according to the second embodiment of the present invention as viewed from the direction perpendicular to the guide rail. It is. Also in the second embodiment, the guide device 1 is common in that it includes guide rails 3 and 4 and guide units 9, 10, 11, and 12. However, the second embodiment is different from the first embodiment in that the guide rail 3 and the guide rail 4 are arranged so as to extend in the vertical direction with respect to the base (not shown). Hereinafter, differences from the first embodiment will be described.

  When the table 2 is arranged so as to slide in the vertical direction as in the second embodiment, the position of the center of gravity of the table 2 is away from the guide rails 3 and 4. A moment force is generated around the virtual rotation center A. The virtual rotation center A is a substantially middle point on an imaginary line connecting the fixed center of the guide unit 9 in the guide rail 3 and the fixed center of the guide unit 10 in the guide rail 3. The direction of the force F exerted on the guide rail by the guide unit 9 on the upper side in the vertical direction of the guide rail 3 is opposite to the direction of the force F exerted on the guide rail by the guide unit 10 and has the same magnitude. Here, the fixed center of the guide unit 9 in the guide rail 3 is, for example, as shown in FIG. 2A, in the cross section of the guide rail 3 and the guide unit 9, the rolling elements 13a of the first rolling element group row and the first sliding member. The contact point with the moving surface 3b and the contact point between the rolling element 13b of the second rolling element group row and the second sliding surface 3c are almost the midpoint.

Furthermore, when the inside of the guide unit 9 in the second embodiment is viewed in detail, there is a difference in the pressing force applied to the sliding surface from the rolling elements in the guide unit. Also in the second embodiment, the rolling elements 13a, 13b, 13c, and 13d located on the guide rail 3 side are respectively the first sliding surface 3b, the second sliding surface 3c, It arrange | positions so that the 3rd sliding surface 3d and the 4th sliding surface 3e may be contacted in the state where the preload was loaded so that it might be pressed. However, considering the state of FIG. 2A in the case of the second embodiment, the load is opposite to that of the first embodiment. That is, the guide unit 9 by the applied load W ₁ of the weight fraction of its own weight and machine tool parts of the table 2, it receives the rotational moment about a virtual rotation axis A that is loaded toward the underside of the table 2. When the distance between the load center of the load W ₁ and the virtual axis of rotation A and R _1, the magnitude of the rotational moment becomes W ₁ R _1. Due to the rotational moment W ₁ R ₁ , the guide unit 9 receives a force F in a direction away from the guide rail 3. On the other hand, the guide unit 10 is pressed against the guide rail 3 with the force F having the same magnitude as that force and in the opposite direction. Therefore, in the guide unit 9, in the guide unit 9, the preload applied to the rolling elements 13a and 13c increases, and the preload applied to the rolling elements 13b and 13d decreases. That is, in this case, when the guide unit 9 receives a force in a direction away from the guide rail 3, the rolling elements 13a and 13c are further pressed against the first sliding surface 3b and the third sliding surface 3d. . Conversely, in the guide unit 10, the preload applied to the rolling elements 13a and 13c decreases, and the preload applied to the rolling elements 13b and 13d increases. That is, in this case, because the guide unit 10 is pressed against the guide rail 3, the rolling elements 13b and 13d are further pressed against the second sliding surface 3c and the fourth sliding surface 3e. The same applies to the guide rail 4, the guide unit 11 positioned vertically above is in the same state as the guide unit guide unit 9, and the guide unit 12 positioned below vertically is in the same state as the guide unit guide unit 10. . Thus, the guide units 9, 10, 11, 12 are in a load imbalance state due to the moment generated by the load applied to the table 2 in the vertical direction.

  In order to eliminate these load imbalances, in the second embodiment, two pressing means of the first embodiment are arranged between the guide unit 9 and the guide unit 10 that are inserted into the guide rail 3. . That is, the first pressing means 5a is arranged between the guide unit 9 and the guide unit 10 on the upper side in the vertical direction, and between the first pressing means 5a and the lower guide unit 10 and below the first pressing means 5a in the vertical direction. 2nd press means 5b is arrange | positioned. The first pressing means 5 a can project the first guide means 7 a having the first sliding guide surface 7 aa from a storage position separated from the guide surface 3 a of the guide rail 3 to a pressing position for pressing the guide surface 3 a. As a result, the first sliding guide surface 7a can be pressed against the guide surface 3a. The second pressing means 5b can project the second guide means 7b having the second sliding guide surface 7ba from a storage position separated from the guide surface 3a of the guide rail 3 to a pressing position for pressing the guide surface 3a. As a result, the second sliding guide surface 7ba can be pressed against the guide surface 3a. Similarly, two pressing means are arranged on the guide rail 4 side.

  And the 1st press means 5a and the 2nd press means 5b are the pressing force loaded with respect to the sliding surface from the rolling element group row | line | column of the guide unit 9 which is a 1st guide unit, and the guide unit 10 which is a 2nd guide unit. The first sliding guide surface 7aa and the second sliding guide surface 7ba are pressed against the guide surface 3a so that the pressing force applied to the sliding surface from the rolling element group row of The guide unit 9 and the guide unit 10 can slide along the guide rail 3 while sliding on the one sliding guide surface 7a and the second sliding guide surface 7b. The same applies to the guide unit 11 and the guide unit 12 for the other guide rail 4. The sliding guide surface 7a and the sliding guide surface 8a are the same as in the first embodiment in that the DLC film is coated.

The pressing force fa (first pressing force) of the first pressing means 5a and the pressing force fb (second pressing force) of the second pressing means 5b are set as follows. First, fa and fb may be set based on the following (1) so that the rotational moment W ₁ R ₁ around the virtual rotation center A and the reverse rotational moment are balanced.

W ₁ R ₁ + fa · ra ₁ = fb · ra ₂ (1)

For example, first, the pressing force fb of the second pressing means 5b is determined so as to satisfy the expression (2) without considering (ignoring) the pressing force fa of the first pressing means 5a. Then, in order to obtain optimal sliding on the premise of the pressing force fb, the pressing force fa of the first pressing means 5b is set to guide the first sliding guide surface 7a and the guide rail so as to satisfy the expression (2). It is determined from the coefficient of friction with the surface 3a. Although ra ₁ and ra ₂ are generally set as different distances, they may be equidistant. The set pressing force fa, selects the optimal distance from the balance of the moment by moment and W ₁ by fb.

(Third embodiment)
Then, the hybrid type guide apparatus of 3rd embodiment of this invention is demonstrated with reference to FIG. The hybrid guide device of the third embodiment is an embodiment in which a guide rail is further provided in the vertical direction with the guide rail arranged to extend in the vertical direction in the second embodiment. That is, the guide rail 9 and the guide rail 10 are arranged on the base 12 in the vertical direction, and the guide rail 13 and the guide rail 14 are arranged so as to extend in a direction perpendicular to the guide rail 9 and the guide rail 10. A guide unit 15 and a guide unit 16 are inserted into the guide rail 13 and the guide rail 14, respectively. Although not shown so that the base 12 slides smoothly on the guide rail 13 and the guide rail 14, the guide rail 13 and the guide rail 14 include guide units other than the guide unit 15 and the guide unit 16. Evenly arranged.

A third pressing means 17 is arranged between the guide units inserted into the guide rails 13 so that the guide surfaces of the guide rails 13 can be pressed by the sliding guide surfaces. Similarly, a fourth pressing means 18 is disposed between the guide units inserted into the guide rails 14 so that the guide surfaces of the guide rails 14 can be pressed by the sliding guide surfaces. Guide unit 15 positioned above the guide unit 16 positioned below the by the load size W ₂ by a load applied load weight, such as the base 12 and the guide rails 3 and 4 to the applied load W ₁ of Table 2 A rotational moment around the virtual rotation center B is received. From the virtual rotation center B, which is the midpoint of the virtual line connecting the center of the cross section of the guide rail 15 and the center of the cross section of the guide rail 16, the base 12, the guide rails 3, 4 and the guide units 9, 10, 11, 12 If the distance between the center of gravity of the total load weight W ₂ was R _2, including the torque amount about the virtual center of rotation B is a W ₂ R _2. Therefore, as in the second embodiment, the sliding guide surfaces of the third pressing means 17 and the fourth pressing means 18 are the guide surfaces of the guide rails 13 and 14, respectively, so that the rotational moments around the virtual rotation center B are balanced. The pressing forces fc and fd for pressing are set as follows, similarly to the pressing forces fa and fb in the second embodiment.

First, fc and fd may be set based on the following (2) so that the rotational moments in the opposite direction are balanced against the rotational moment W ₂ R ₂ around the virtual rotation center B.

W ₂ R ₂ + fc · rb ₁ = fd · rb ₂ (2)

For example, first, the pressing force fd of the fourth pressing means 18 is determined so as to satisfy the expression (2) without considering (ignoring) the pressing force fc of the third pressing means 17. Then, in order to obtain optimal sliding on the premise of the pressing force fd, the sliding guide surface and the guide rail between which the pressing unit presses the pressing force fc of the third pressing unit 17 so as to satisfy the expression (2) are satisfied. It is determined from the coefficient of friction with the guide surface. rb ₁ and rb ₂ are generally set as equidistant. The set pressing force fc, selects the optimal distance from the balance of the moment by moment and W ₂ by fd. The sliding guide surfaces of the third pressing means 17 and the fourth pressing means 18 are the same as in the first embodiment in that a DLC film coating process is performed.

DESCRIPTION OF SYMBOLS 1 Guide apparatus 2 Table 3, 4 Guide rail 5, 6 Press means 7, 8 Guide means 7a, 8a Sliding guide surface 9, 10, 11, 12 Guide unit 13 Rolling body

Claims (10)

A guide unit for supporting the work table;
A guide rail inserted into the guide unit, the guide rail having a guide surface extending along the guide rail;
A machine tool guide device comprising: a pressing means having a sliding guide surface protruding from a position spaced from the guide surface to a position pressing the guide surface and capable of pressing the guide surface against the work table. ,
The guide unit has a rolling element group row for the guide unit to slide along the guide rail,
The pressing means presses the sliding guide surface against the guide surface with a predetermined pressing force, and the guide unit moves along the guide rail while the sliding guide surface slides on the guide surface in this state. A machine tool guide device characterized by being slidable. The machine tool guide device according to claim 1,
A guide device for a machine tool, wherein the sliding guide surface is coated with a DLC film. The machine tool guide device according to claim 1 or 2,
The predetermined pressing force is a force having, as a component in the gravitational direction, a gravitational load that is apportioned to the guide rail in response to a gravitational load from the work table. Guide device. The machine tool guide device according to any one of claims 1 to 3, wherein the machine tool guide device further includes:
Equipped with another guide unit that supports and slides the work table,
The other guide unit has a rolling element group row for sliding along the guide rail,
The guide device, wherein the pressing means is disposed between the guide unit and the other guide unit. A first guide unit for supporting the work table;
A second guide unit for supporting a work table below the first guide unit; a guide rail inserted into the first guide unit and the second guide unit, the guide extending along the guide rail A guide rail with a surface;
A first pressing means having a first sliding guide surface protruding from a position spaced from the guide surface to a position for pressing the guide surface and capable of pressing the guide surface against the work table;
A second pressing means having a second sliding guide surface protruding from a position spaced from the guide surface to a position for pressing the guide surface and capable of pressing the guide surface against the work table;
A machine tool guide device comprising:
Each of the first guide unit and the second guide unit has a rolling element group row for sliding along the guide rail,
The first pressing means presses the first sliding guide surface against the guide surface with a first pressing force, the second pressing means presses the second sliding guide surface against the guide surface with a second pressing force, In this state, the first guide unit and the second guide unit can slide along the guide rail while the first sliding guide surface and the second sliding guide surface slide on the guide surface. A machine tool guide device. The machine tool guide device according to claim 5,
A guide device for a machine tool, wherein the first sliding guide surface and the second sliding guide surface are coated with a DLC film. The machine tool guide device according to claim 5 or 6,
The guide device for a machine tool, wherein the second pressing force is larger than the first pressing force. A first guide rail that is inserted and fitted into a first guide unit that supports the work table, the first guide rail having a first guide surface extending along the first guide rail;
A second guide rail disposed below the first guide rail and inserted into a second guide unit that supports the work table, and has a second guide surface extending along the second guide rail. A second guide rail,
A first guide unit inserted into the first guide race;
A second guide unit inserted into the second guide race;
A first pressing means having a first sliding guide surface protruding from a position spaced from the first guide surface to a position for pressing the first guide surface and capable of pressing the first guide surface against the work table; ,
A second pressing means having a second sliding guide surface protruding from a position spaced from the second guide surface to a position for pressing the second guide surface and capable of pressing the second guide surface against the work table; ,
The first guide unit and the second guide unit each have a rolling element group row for sliding along the first guide rail and the second guide rail,
The first pressing means presses the first sliding guide surface against the guide surface with a first pressing force, the second pressing means presses the second sliding guide surface against the guide surface with a second pressing force, In this state, the first guide unit and the second guide unit can slide along the guide rail while the first sliding guide surface and the second sliding guide surface slide on the guide surface. A machine tool guide device. A machine tool guide device according to claim 8,
A guide device for a machine tool, wherein the first sliding guide surface and the second sliding guide surface are coated with a DLC film. The machine tool guide device according to claim 8 or 9,
The guide device for a machine tool, wherein the second pressing force is larger than the first pressing force.

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