JP4466502B2 - Feed guide device - Google Patents

Description

  The present invention relates to a feed guide device used for a table or the like of a machine tool or the like, and more particularly to a device that suppresses the table from being lifted and tilted by the dynamic pressure of lubricating oil generated during high-speed feed.

  In this type of table feeder, a flat guide surface is formed on a base, and the table is slidably guided thereon. Lubricating oil is dripped on the guided surface of the table. The table is sent on the base by an appropriate driving device.

  In such a conventional apparatus, when the table S is fed on the base B at a high speed as shown in FIG. 1A, the lubricating oil O is caught at the front end in the traveling direction, and the solid line in FIG. Since the dynamic pressure is generated and the movable body S is lifted and tilted by this dynamic pressure, the frictional force and the sliding resistance increase, and a large feed power is required. As a result, non-uniformity of the sliding surface contact state of the guided surface of the movable body S and fluctuations in the feed force occur. The broken line in FIG. 1B shows the distribution of pressure acting on the guided surface S1 of the movable body S during low speed feeding.

  In order to solve this, it is conceivable to narrow the width over the entire length in the longitudinal direction of the guided surface of the movable body S, but by narrowing the width over the entire length in the longitudinal direction of the guided surface, the inclination of the table increases. Deterioration in feed and machining accuracy. The coefficient of friction also increases, and abnormalities in the feed torque acting on the motor also occur, so there is a limit to reducing the width of the table.

According to the present invention, as described in claim 1, a guide surface is formed on the base, and the movable body is slidably guided by the dynamic pressure action with lubricating oil interposed on the guide surface. in feeding guide device which, the oil groove to which the opposite ends are communicated with the atmosphere extends in the feed direction and perpendicular direction before Symbol movable body, so as to equally divide the guided surface of the movable member in the feeding direction of said movable member more by providing Rukoto, is characterized in that the pressure was to divide the dynamic pressure generated in the guided surface open to the atmosphere in the oil groove to.
According to a second aspect of the present invention, the oil groove has a width of about 10 mm and a depth of about 5 mm.

According to the invention described in claim 1, the oil groove to which the opposite ends are communicated with the atmosphere extends in the feed direction and perpendicular direction before Symbol movable body, the guided surface of the movable member in the feeding direction of said movable member the plurality Rukoto to evenly split by the pressure in the oil groove portions so as to divide the dynamic pressure generated in the guided surface open to the atmosphere, based on the traveling direction front end portion of said movable member It can be pressed onto the guide surface of the table to suppress excessive lifting and tilting of the movable body.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 2, a flat guide surface 2 is formed on a base 1, and a table (movable body) 3 having a guided surface 3a slidingly engaged with the flat guide surface 2 on the lower surface is shown in the horizontal direction in the figure. It is slidably guided. A lubricating oil pipe 10 is attached to the table 3, and the pipe 10 drops, for example, lubricating oil fed from the lubricating oil supply device 9 via the flexible pipe 10 a onto the guide surface 2 from the front and rear ends of the table.

  A spindle head 6 is fixed on the table 3, and a spindle 8 rotated by a motor 7 is rotatably supported on the spindle head 6. A cutting tool T is attached to the tip of the main shaft 8. The spindle head 6 is moved forward and backward in the illustrated left-right direction integrally with the table 3 by a screw feed mechanism 12 driven by the servo motor 4. When the table 3 is a rectangular slide member, the front end in the forward direction of the guided surface 3a of the table 3 entrains lubricating oil during high-speed feeding, and the dynamic pressure generated between this and the flat guide surface 2 causes the table 3 3 floats so that the front end portion in the feed direction is inclined upward, and as a result, the contact state of the slide surface is not uniform and the required power of the motor varies.

  In this invention, it is comprised so that the pressure distribution of the lubricating oil which acts on the to-be-guided surface 3a of the lower surface of the table 3 may become substantially uniform over the full length direction of a table. In general, considering the effect of the width of the guided surface of the table on the lift, tilt, friction force, and coefficient of friction of the table, the lift decreases as the width, that is, the pressure receiving area decreases, and the tilt decreases the width of the table. As the table length is constant, the friction force increases as the table width decreases, and the friction coefficient increases rapidly.

  Accordingly, considering the lifting of the table 3, it is desired to make the width of the table 3 narrower. However, in this case, the inclination of the table 3 increases, the friction coefficient increases rapidly, and the lubricity deteriorates. Need a width. Therefore, in the first embodiment of the present invention, as shown in FIG. 3, the guided surface 3a of the table 3 is provided with a V-shaped notch 30 from the both side portions 3L, 3R of the table to the central portion in the longitudinal direction. Thus, the width of the central portion is narrower than both end portions in the feeding direction. Preferably, the width b of the central portion is about 80% of the total width B, and the width of the notch 30 in the table longitudinal direction is about 1/3 to 1/4 of the total length L.

  When the table 3 is fed at a high speed, lubricating oil is caught between the front end portion of the guided surface 3a of the table 3 in the traveling direction and the flat guide surface 2 of the base 1, and dynamic pressure is generated therebetween. However, by forming the guided surface 3a of the table 3 in such a shape, in this embodiment, the pressure receiving area at the central portion in the longitudinal direction of the table 3 is reduced, so that the lifting force at the central portion is increased. Is smaller than that of the conventional apparatus, and the tilt and the amount of lifting of the table are suppressed.

  According to the experiment on the guide device having the guided surface shape of the table 3 described above, it was possible to reduce the lift by 5%, the inclination by 5%, and the friction force by 3% as compared with the conventional device. The table dimensions used in this experiment were 800 mm long, 135 mm wide, and 70 mm high. In this experiment, the table was sent at a speed of 30 m / min.

  As a modification of the embodiment related to the guided surface 3a of the table 3, as shown in FIG. 4 (a), both ends in the feed direction are connected by the radius of curvature R, or as shown in FIG. It is also possible to adopt a shape in which up to a straight line is connected, or a shape in which only the central portion in the longitudinal direction is connected by a single arc as shown in FIG. In each of the above-described embodiments, the present invention is achieved by changing the pressure receiving area of the guided surface 3a of the table 3. However, according to other embodiments described below, the present invention operates on a conventional table guide. The present invention can be achieved by providing means for canceling the ridge-shaped pressure distribution at one or several places in the longitudinal direction of the table.

  FIG. 5 (a) shows an example of this solution. One or several oil grooves 15 are arranged on the guided surface 3a of the table 3 perpendicular to the feed direction. More specifically, three oil grooves 15 having a width of about 10 mm and a depth of about 5 mm are equally inserted in the guided surface 3a of the table 3 having the above dimensions. Both ends of each oil groove 15 are opened to the atmosphere. It is desirable that the number of divisions of the guided surface 3 a by the oil groove 15 is 2 to 4 according to the size of the table 3.

  With this configuration, the pressure is released to the atmosphere in the oil groove and becomes 0, so that the dynamic pressure generated on the lower surface of the table 3 can be divided as shown in FIG. In this case, a large pressure is generated at the last part in the traveling direction. Due to this pressure (reaction force F), a rotational moment is generated in the table 3, and the front in the traveling direction is pressed onto the guide surface 2 of the base 1, and excessive lifting and tilting of the table 3 are suppressed.

  A function similar to this can be achieved by other than the groove. For example, a plurality of holes communicating with the atmosphere in place of the grooves 15 may be formed in the direction along the grooves 15 at the positions where the grooves 15 are formed on the guided surface 3a of the table. In the embodiment having the groove 15 described above, the lift and inclination of the table 3 decrease with an increase in the number of divisions, and the pressure distribution in the traveling direction acting on the guided surface 3a has a reaction force at the rear end portion in the traveling direction. The distribution state is effectively generated, and the inclination of the table is suppressed.

  In each of the embodiments described above, the feed guide device of the type in which the table 3 slides on the single flat guide surface 2 is mentioned. However, the present invention can be applied only to the flat guide surface of the above-described embodiment. It is not limited. For example, a type having two guide surfaces that are separated from each other in the direction perpendicular to the feed direction, both of the two guide surfaces being flat guide surfaces, or one of the two guide surfaces being V-shaped. The present invention can also be applied to a type in which the other is a flat guide surface.

  Further, each of the pair of guide surfaces spaced apart in the direction perpendicular to the feed direction is formed in a “U” shape, and guided portions on both sides of the lower surface of the movable body are guided by the “U” shape guide surfaces. The present invention is also applicable to a type of feeding guide device.

The state figure at the time of the movable body movement in the conventional feed guide apparatus. The side view of the feed guide apparatus of the machine tool to which this invention is applied. The bottom view which shows the shape of the to-be-guided surface of the movable body by 1st Embodiment of this invention. The bottom view which shows the modification of the to-be-guided surface in the said 1st Embodiment. The side view of the movable body by 2nd Embodiment of this invention, a bottom view, and explanatory drawing which shows the behavior of the movable body at the time of high-speed feeding, and the pressure distribution which acts on a to-be-guided surface.

Explanation of symbols

1 Base 2 Flat guide surface 3 Table (movable body)
3a Guided surfaces 3L, 3R Table both sides 6 Spindle head 9 Lubricating oil supply device 10 Pipe 15 Oil groove 30 Notch

Claims (2)

In a feed guide device in which a guide surface is formed on a base, and a movable body is slidably guided by a dynamic pressure action with lubricating oil interposed on the guide surface.
The oil groove whose ends are communicated with the atmosphere extends in the feed direction and perpendicular direction before Symbol movable body, a plurality Rukoto to evenly divide the guided surface of the movable member in the feeding direction of said movable member The feed guide device according to claim 1, wherein pressure is released to the atmosphere in the oil groove and the dynamic pressure generated on the guided surface is divided .   The feed guide apparatus according to claim 1, wherein the oil groove has a width of about 10 mm and a depth of about 5 mm.