JP2006088256A - Work support mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of clamp distortion in a work in pressing the work to a work support mechanism and stably support the work. <P>SOLUTION: This work support mechanism 11 includes: a semi-spherical member 13 having a flat top face 17 for placing a work W and a spherical base 19; and a bearing seat 15 having a spherical recessed part 21 shaped substantially complementary to the spherical base 19 of the semi-spherical member 13. The spherical base 19 of the semi-spherical member 13 is faced to the surface of the spherical recessed part 21 and fitted to the bearing seat 15, and the semi-spherical member 13 is rotatable to the bearing seat 15. Further, the surface of the spherical recessed part 21 is provided with a jet hole 25 for jetting a fluid between the spherical base 19 of the semi-spherical member 13 and the surface of the spherical recessed part 21, and a relief groove 27 extending from the jet hole 25 to the opening edge of the spherical recessed part 21 is formed on the surface of the part 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a workpiece support mechanism for supporting a workpiece with a machine tool or the like.

  In a machine tool such as a machining center, a boring machine, or a milling machine, when machining a workpiece, the workpiece is placed on a fixture, and the edge of the workpiece is pressed toward the fixture to be fixed to the fixture. However, when the workpiece seating surface is cast, it is often not flat. When the workpiece is pressed against the fixture as it is, the workpiece seating surface that is in partial contact with the reference surface of the fixture will be As a result of the force to be brought into contact, the workpiece may be distorted and the machining accuracy may be adversely affected. Therefore, for example, as described in Patent Document 1, there is a case in which a work support mechanism that can freely change the angle of the contact surface in accordance with the inclination of the surface of the work is provided on the fixture side.

  A workpiece support mechanism as described in Patent Document 1 includes a hemispherical member having a top surface to be brought into contact with the workpiece and a spherical bottom surface, and a spherical recess having a shape complementary to the spherical bottom surface of the hemispherical member. And a receiving seat. The hemispherical member is fitted to the receiving seat with the spherical bottom surface of the hemispherical member facing the surface of the spherical concave portion, and the hemispherical member is fitted around the center point of the spherical bottom surface. It can be rotated freely. Therefore, when the work is pressed against the top surface of the hemispherical member, the hemispherical member rotates relative to the receiving seat, and the top surface of the hemispherical member comes into contact with the seating surface of the work. As a result, the top surface of the hemispherical member and the seating surface of the workpiece are easily in contact with each other, thereby suppressing the occurrence of clamp distortion.

Japanese Patent Publication No. 63-22934

  However, when the work support mechanism is used to support the work on the table with a machine tool or the like, a force in the direction of pressing the work toward the table acts to fix the work to the table, so that the work comes into contact with the work. A force to press the hemispherical member toward the receiving seat positioned on the table side also acts. For this reason, the hemispherical member is pressed against the spherical concave portion of the receiving seat, and the friction between the spherical bottom surface of the hemispherical member and the surface of the spherical concave portion of the receiving seat increases, and the hemispherical member rotates with respect to the receiving seat. The top surface of the hemispherical member is not necessarily in parallel with the seating surface of the workpiece and does not come into contact with the workpiece.

  In order to deal with such a problem, an air outlet is provided on the surface of the spherical concave portion of the receiving seat and compressed into a minute gap between the spherical bottom surface of the hemispherical member and the surface of the spherical concave portion of the receiving seat. A method has been proposed in which, by supplying air, the hemispherical member is kept lifted with respect to the concave surface of the receiving seat by the static pressure of the compressed air, and the friction is reduced. In this case, the force toward the receiving seat acting on the hemispherical member through the workpiece overcomes the force that the hemispherical member floats from the surface of the spherical concave portion of the receiving seat with compressed air, so that the spherical bottom surface of the hemispherical member becomes The hemispherical member can be easily rotated with respect to the seat until it is pressed against the surface of the spherical recess of the seat and closes the air outlet. However, when the spherical bottom surface of the hemispherical member approaches the surface of the spherical concave portion of the receiving seat due to the pressing force, the resistance to the ejection of air from the ejection port increases, resulting in pressure vibration due to the compressibility of the air. It has been found that this causes a problem that the hemispherical member vibrates and vibrates the workpiece.

  Therefore, the object of the present invention is to solve the above-described problems in the prior art and prevent the workpiece from being clamped and stably generated when the workpiece is pressed against the workpiece support mechanism for supporting the workpiece. The goal is to be able to support the workpiece.

  To achieve the foregoing object, the present invention provides a hemispherical member having a flat top surface and a spherical bottom surface for placing a workpiece, and is substantially complementary to the spherical bottom surface of the hemispherical member. A receiving seat having a spherical concave portion, and the spherical bottom surface of the hemispherical member faces the surface of the spherical concave portion and is fitted to the receiving seat, and the workpiece is fitted to the hemispherical member. In the workpiece support mechanism in which the hemispherical member can rotate with respect to the receiving seat so that the top surface of the hemispherical member is parallel to the surface of the workpiece when contacting the top surface. A spout is provided on the surface of the spherical concave portion between the spherical bottom surface of the member and the surface of the spherical concave portion, and a groove extending from the spout to the opening edge of the spherical concave portion is formed. A workpiece support mechanism configured to be provided is provided. .

Since the fluid is ejected from the spout provided in the spherical concave portion of the receiving seat between the spherical bottom surface of the hemispherical member and the surface of the spherical concave portion of the receiving seat, the hemispherical member is received by the static pressure of the fluid. Thus, the friction between the spherical bottom surface of the hemispherical member and the surface of the spherical recess of the receiving seat is remarkably reduced. Therefore, the force in the pressing direction acting on the receiving seat acting on the hemispherical member through the workpiece overcomes the static pressure of the fluid that causes the hemispherical member to float from the surface of the spherical concave portion of the receiving seat, and the spherical bottom surface of the hemispherical member becomes Until the surface of the spherical concave portion of the receiving seat comes into contact, the hemispherical member freely rotates with respect to the spherical concave portion of the receiving seat, and the top surface of the hemispherical member becomes easily parallel to the seating surface of the workpiece. Further, since a groove extending from the jet outlet to the opening edge of the spherical concave portion is formed on the surface of the spherical concave portion of the receiving seat, the spherical bottom surface of the hemispherical member is a spherical surface around the jet outlet of the receiving seat. Even when it comes into contact with the surface of the concave portion, the fluid ejected from the outlet can flow along the groove formed on the surface of the spherical concave portion. Therefore, even if the spherical bottom surface of the hemispherical member and the spout of the spherical concave portion of the receiving seat approach or come into contact with each other, the resistance to the fluid ejected from the spout does not increase abruptly. It is possible to prevent the occurrence of pressure vibration due to this pressure rise.
Note that the term “hemispherical member” in the present application may consist of a part larger than the hemisphere or a part smaller than the hemisphere in the complete spherical surface.

  In the work support mechanism, the jet port is provided at the center of the surface of the spherical recess, and the grooves extend from the jet port in opposite directions toward the opening edge of the spherical recess. Is preferred.

  According to the present invention, the hemisphere is generated by the static pressure of the fluid ejected between the spherical bottom surface of the hemispherical member and the surface of the spherical concave portion of the receiving seat from the outlet provided on the surface of the spherical concave portion of the receiving seat. Since the shaped member floats up with respect to the receiving seat and can rotate freely with respect to the receiving seat so that the top surface of the hemispherical member can be easily parallel to the seating surface of the workpiece, a pressing force is applied to the workpiece. It is possible to suppress clamp distortion that sometimes occurs in the workpiece. In addition, even if the spherical bottom surface of the hemispherical member approaches or contacts the surface of the spherical concave portion of the receiving seat due to the action of the groove formed on the surface of the spherical concave portion of the receiving seat, As a result, a sudden pressure increase of the fluid does not occur, and the vibration of the hemispherical member caused by the rapid pressure increase can be avoided, so that the workpiece can be supported stably.

  Hereinafter, an embodiment of a work support mechanism of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view of a workpiece support mechanism of the present invention, and FIG. 2 is a view of a receiving seat of the workpiece support mechanism of FIG. The workpiece support mechanism is mounted on a fixture provided on a table or the like of the machine tool and constitutes a reference plane of the fixture.

  Referring to FIG. 1, the work support mechanism 11 includes a hemispherical member 13 and a receiving seat 15. The hemispherical member 13 has a flat top surface 17 on which the workpiece W is placed and a spherical bottom surface 19. The hemispherical member 13 does not have to be a strict hemisphere, and may be a smaller part than a hemisphere obtained by cutting a complete sphere below the equator, and may be a hemisphere obtained by cutting a complete sphere above the equator. May be a large part.

  On the other hand, a spherical concave portion 21 having a shape substantially complementary to the spherical bottom surface 19 of the hemispherical member 13 is formed on the upper surface of the receiving seat 15, and the spherical bottom surface 19 of the hemispherical member 13 is formed on the spherical concave portion 21. The hemispherical member 13 is fitted in the spherical concave portion 21 in a state of facing the surface of. Specifically, the spherical concave portion 21 of the receiving seat has a slightly larger radius than the spherical bottom surface 19 of the hemispherical member 13, and the center point of the spherical bottom surface 19 of the hemispherical member 13 and the spherical concave portion. When arranged so as to coincide with the center point of 21, a gap is formed between the spherical bottom surface 19 of the hemispherical member 13 and the surface of the spherical recess 21 of the receiving seat 15.

  Further, as in the embodiment shown in FIG. 1, the spherical concave portion 21 formed in the receiving seat 15 has a hemispherical shape, and the hemispherical member 13 has a shape obtained by cutting a complete sphere above the equator. An annular member 29 having a spherical inner peripheral surface so as to cover a portion above the equator of the hemispherical member 13 accommodated in the spherical concave portion 21 of the receiving seat 15. Is preferably attached to the upper surface of the receiving seat 15. By adopting such a structure, it is possible to hold the hemispherical member 13 in the receiving seat 15 and prevent it from dropping out of the spherical recess 21.

  The receiving seat 15 is further provided with a fluid supply passage 23, and the fluid supply passage 23 opens on the surface of the spherical recess 21 to form a jet outlet 25. Accordingly, by supplying fluid to the fluid supply passage 23 of the receiving seat 15, fluid is ejected from the spout 25 of the spherical recess 21 between the spherical bottom surface 19 of the hemispherical member 13 and the surface of the spherical recess 21. It can be made to. Since the fluid ejected from the ejection port 25 tends to circulate evenly in the space between the spherical bottom surface 19 of the hemispherical member 13 and the surface of the spherical recess 21, the ejection port 25 is formed on the surface of the spherical recess 21. Is preferably formed at the lowest position of the spherical recess 21. As the fluid, compressed air, coolant, lubricating oil, or the like can be used.

  Further, as shown in FIG. 2, the surface of the spherical recess 21 has a relief groove extending from the jet outlet 25 to the opening edge of the spherical recess 21 in the opposite direction along the surface of the spherical recess 21. 27 is formed, and even when the hemispherical member 13 comes into contact with the spherical concave portion 21, the fluid ejected from the ejection port 25 passes between the spherical bottom surface 19 of the hemispherical member 13 and the surface of the spherical concave portion 21. It can be discharged to the outside of the receiving seat 15 along the escape groove 27. Accordingly, even when the spherical bottom surface 19 of the hemispherical member 13 is close to or in contact with the surface of the spherical concave portion 21, the fluid can be ejected from the ejection port 25, and the fluid pressure does not increase rapidly. It is possible to prevent the fluid pressure vibration caused by the rapid pressure rise and the hemispherical member 13 vibration caused thereby. Although the illustrated escape groove 27 is composed of only one piece, a plurality of escape grooves 27 may be provided.

Next, the operation of the work support mechanism 11 in FIG. 1 will be described.
First, the workpiece W is placed on the top surface 17 of the hemispherical member 13 of the workpiece support mechanism 11 with the fluid supplied to the fluid supply passage 23 of the receiving seat 15. Then, the hemispherical member 13 passes through the fluid supply passage 23, and the spherical recess 21 is caused by the static pressure of the fluid ejected from the jet outlet 25 between the spherical bottom surface 19 of the hemispherical member 13 and the surface of the spherical recess 21. Of the hemispherical member 13 according to the inclination of the seating surface of the workpiece W so that the contact area with the seating surface of the workpiece W is maximized. The top surface 17 is tilted. That is, the hemispherical member 13 rotates in the spherical recess 21 so that the top surface 17 thereof is parallel to the seating surface of the workpiece W.

  Next, in order to clamp the workpiece W, a pressing force is applied to the workpiece W from above the workpiece W toward the workpiece support mechanism 11. Then, until the pressing force overcomes the force that pushes up the hemispherical member 13 by the fluid ejected from the ejection port 25, the minute unevenness of the seating surface of the work W is crushed on the top surface 17 of the hemispherical member 13 and seated. The hemispherical member 13 is further rotated so that the surface becomes a stable and smooth surface and the top surface of the hemispherical member 13 is parallel to the smooth surface. Thereby, the support of the workpiece W by the workpiece support mechanism 11 is further stabilized.

  When the pressing force is further increased and the pressing force overcomes the pressure of the fluid ejected from the ejection port 25, the hemispherical member 13 approaches the spherical concave portion 21, and the spherical bottom surface 19 of the hemispherical member 13 is at its lowermost portion. In this case, the surface comes into close contact with the surface of the spherical recess 21. Even in this state, the fluid ejected from the ejection port 25 passes through the escape groove 27 formed in the spherical recess 21 of the receiving seat 15, and the spherical bottom surface 19 of the hemispherical member 13 and the surface of the spherical recess 21. Since the liquid flows out from the gap to the outside of the receiving seat 15, the resistance to the fluid ejected from the ejection port 25 does not rapidly increase. Therefore, no pressure vibration is generated due to a sudden rise in fluid pressure, and no vibration is generated in the hemispherical member 13 and the workpiece W supported by the hemispherical member 13. Thus, according to the present invention, even when a strong pressing force is applied to the workpiece W for clamping the workpiece W, stable support can be continuously given to the workpiece W.

It is a sectional side view of the workpiece | work support mechanism of this invention. It is the figure which looked at the receiving seat of the workpiece | work support mechanism of FIG. 1 from upper direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Work support mechanism 13 Hemispherical member 17 Top surface 19 Spherical bottom 21 Spherical recessed part 25 Spout 27 Relief groove

Claims (2)

A hemispherical member having a flat top surface and a spherical bottom surface for placing a workpiece, and a receiving seat having a spherical concave portion that is substantially complementary to the spherical bottom surface of the hemispherical member. The hemispherical member when the spherical bottom surface of the hemispherical member faces the surface of the spherical concave portion and is fitted to the receiving seat, and the workpiece is brought into contact with the top surface of the hemispherical member. In the workpiece support mechanism in which the hemispherical member can rotate with respect to the receiving seat so that the top surface of the workpiece is parallel to the surface of the workpiece,
A spout for ejecting fluid is provided on the surface of the spherical concave portion between the spherical bottom surface of the hemispherical member and the surface of the spherical concave portion, and extends from the spout to the opening edge of the spherical concave portion. A workpiece support mechanism characterized by forming a groove. 2. The workpiece according to claim 1, wherein the ejection port is provided at the center of the surface of the spherical recess, and the grooves extend from the ejection port in opposite directions toward the opening edge of the spherical recess. Support mechanism.

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