JP2011163504A - Linear guide device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear guide device which is easy to manufacture and is excellent in durability. <P>SOLUTION: The linear guide device includes a shaft body 11 having a circular cross-section, and including a plurality of linear grooves 11a formed on the outer periphery thereof at circumferential intervals so as to extend in the longitudinal direction; a columnar body 12 received in each linear groove 11a, the columnar body having a circular cross section and extending in the longitudinal direction of the linear grooves 11; and an outer cylinder 13 which receives the shaft body 11 so as to be non-rotatable but slidable through the columnar body 12. In a cross section along a direction vertical to the central axis of the shaft body 11, the shape of each linear groove 11a of the shaft body 11 has a shape of a circular arc 19 having a radius R<SB>2</SB>larger than the radius R<SB>1</SB>of the columnar body 12, and the center O<SB>1</SB>of the circular arc 19, the center O<SB>2</SB>of the columnar body 12, and the center O<SB>3</SB>of the shaft body 11 are set to be aligned in the same straight line. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear motion guide device that can be used particularly advantageously as a component of an electronic component mounting apparatus that mounts an electronic component on the surface of a printed wiring board.

  Conventionally, a shaft body having a nozzle with an electronic component adsorbed on the lower end is arranged above the printed wiring board, and the shaft body is rotated and moved in the circumferential direction so that the electronic component is disposed at a predetermined angle. Then, an electronic component mounting apparatus is known in which the electronic component is mounted at a predetermined position on the surface of the printed wiring board at a predetermined angle by linearly moving downward (to the printed wiring board side). In order to mount a large number of electronic components on the surface of the printed wiring board in a short time, the shaft body for moving the electronic components is repeatedly rotated and linearly moved at a high speed.

  In order to realize the rotational movement and the linear movement of the shaft body, a linear motion guide device including an outer cylinder that slidably accommodates the shaft body without rotation is used. The shaft body is linearly moved (slided) in the length direction by, for example, operating a linear drive device connected to the shaft body. The shaft body is accommodated in the outer cylinder in a non-rotating state (a state in which relative rotational movement with respect to the outer cylinder is prevented). For example, by operating a rotary drive device connected to the outer cylinder, Rotate with the outer cylinder.

  In Patent Document 1, a shaft body (spline shaft) in which a plurality of linear grooves (spline grooves) are formed on the outer peripheral surface, a plurality of spheres (balls) accommodated in each linear groove of the shaft body, A linear motion guide device is disclosed that includes an outer cylinder (nut body) that accommodates a shaft body in a non-rotatable manner through a plurality of spherical bodies. A cage is provided inside the outer cylinder, and the plurality of rolling elements are accommodated in a circulation path formed by the outer cylinder and the cage.

  FIG. 7 of Patent Document 2 includes a linear motion guide device including an outer cylinder (sleeve) that accommodates a shaft body (spline shaft) through a plurality of columnar bodies (rollers) in a non-rotatable manner. (Spline) is disclosed. A plurality of straight grooves (wide grooves) are formed on the outer peripheral surface of the shaft body. Round grooves are respectively formed at corners of both side surfaces of each linear groove and the outer peripheral surface of the shaft body. And the said columnar body is accommodated in each round groove of each linear groove. In order to adjust the clearance between the round groove and the columnar body of the shaft body, a pressing plate for moving the columnar body to the round groove side is provided between the outer cylinder and the columnar body. The outer cylinder is divided into two, and a taper gib used for driving the holding plate is installed between them.

  This document describes that the columnar body rotates little by little in the direction of load, change in size, and vibration, so that the entire surface of the columnar body is evenly worn and has a long life.

JP 2009-299796 A (FIGS. 1 and 2) Japanese Utility Model Publication No. 53-108677 (FIG. 7)

  In the linear motion guide device of Patent Document 1, when the shaft body linearly moves in the length direction, each rolling element housed in each linear groove of the shaft body rolls in the length direction of the linear groove. That is, the shaft body linearly moves while being supported by a plurality of rolling spheres. For this reason, since the shaft body and the rolling element hardly slide, wear of the shaft body and the rolling element due to the friction between them is suppressed. For this reason, the linear motion guide device exhibits excellent durability. However, the linear motion guide device of Patent Document 1 requires a complicated process for its manufacture because the structure of the cage forming the spherical circulation path is complicated.

  In the linear motion guide device of Patent Document 2, round grooves are formed at the corners of both side surfaces of each linear groove of the shaft body and the outer peripheral surface of the shaft body, and a presser for adjusting the clearance between each round groove and the columnar body. Since the plate is installed and the taper gib used to drive the holding plate has a complicated configuration installed between the two outer cylinders, a complicated process is required for its manufacture and assembly.

  On the other hand, when a shaft that moves linearly is rotated at a high speed (with a large acceleration) together with the outer cylinder, for example, a large load may be momentarily applied in the circumferential direction. . In such a case, the shaft body moves linearly while receiving a large load in the circumferential direction.

  In the linear motion guide device of Patent Document 2, in order to prevent rotational movement of the shaft body in the circumferential direction, the columnar body housed in each round groove of each linear groove is formed by a pressing plate provided inside the outer cylinder. Each is pressed against each round groove so as to rotate and move the shafts in opposite directions. Thus, the shaft body is tightly supported by the plurality of columnar bodies pressed against the respective round grooves of the linear groove so as not to rotate and move in the circumferential direction. For this reason, when a large load is momentarily applied in the circumferential direction of the shaft body as described above, the friction between the shaft body and the columnar body increases, and the wear tends to occur in each. For this reason, there is a possibility that the linear motion guide device disclosed in this document cannot exhibit sufficient durability as a component of an electronic component mounting device in which the rotational movement and linear movement of the shaft body are repeated at high speed.

  An object of the present invention is to provide a linear motion guide device that is easy to manufacture and excellent in durability.

  In the present invention, a cross section in which a plurality of linear grooves each extending in the length direction on the outer peripheral surface is formed at intervals in the circumferential direction is accommodated in a circular shaft body, and each linear groove of the shaft body. A linear motion guide device comprising a columnar body having a circular cross section and extending in a length direction of the linear groove, and an outer cylinder that slidably accommodates a shaft body through the columnar body in a non-rotatable manner. In a cross section cut along a direction perpendicular to the center axis of the body, the shape of each linear groove of the shaft body is an arc shape having a radius larger than the radius of the columnar body, and the center of the arc, In the linear motion guide device, the center of the columnar body and the center of the shaft body are set so as to be aligned on a straight line.

Preferred embodiments of the linear motion guide device of the present invention are as follows.
(1) The radius of the arc of the straight groove is in the range of 1.01 to 1.4 times the radius of the columnar body.
(2) The number of linear grooves of the shaft body is three or more.
(3) The inner peripheral surface of the outer cylinder is provided with a plurality of linear grooves that accommodate the respective columnar bodies. More preferably, a pair of circumferential grooves are formed on the inner circumferential surface of the outer cylinder with a space between each other, and an annular stopper is provided in a state where the outer circumferential portion is fitted to each circumferential groove, and Each said columnar body is arrange | positioned between the inner peripheral parts of both annular stoppers.

  The linear motion guide device of the present invention does not need to further form a round groove in each linear groove of the shaft body, and does not include a complicated structure cage, presser plate, and taper gib that form a circular circulation path. Therefore, it is not necessary to divide the outer cylinder into two parts, so that the manufacture is extremely easy.

  In the linear motion guide device of the present invention, the shaft body can be slightly rotated (slightly rotated) in the circumferential direction. As a result, for example, when a large load is momentarily applied to the shaft body in the circumferential direction, the shaft body rotates slightly, so that an increase in friction between the shaft body and the columnar body based on the load is suppressed. Therefore, the occurrence of wear of the shaft body and columnar body is suppressed. For this reason, the linear motion guide device of the present invention exhibits excellent durability.

It is sectional drawing which shows the structural example of the linear motion guide apparatus of this invention. It is sectional drawing of the linear guide apparatus 10 cut | disconnected along the cutting line II-II line entered in FIG. It is sectional drawing which shows another structural example of the linear motion guide apparatus of this invention. It is sectional drawing of the linear guide apparatus 30 cut | disconnected along the cutting line IV-IV line entered in FIG.

  The cutting device of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a configuration example of a linear guide apparatus according to the present invention, and FIG. 2 is a cross-sectional view of a linear guide apparatus 10 cut along a cutting line II-II written in FIG. It is.

The linear motion guide device 10 includes a shaft body 11 having a circular cross section in which a plurality of linear grooves 11a each extending in the longitudinal direction are formed on the outer peripheral surface with a space therebetween in the circumferential direction, and each linear groove of the shaft body 11 11a, a columnar body 12 having a circular cross section and extending in the length direction of the linear groove 11a, and an outer cylinder 13 that accommodates the shaft body 11 through the columnar body 12 so as to be slidable without rotation. It is configured. As shown in FIG. 2, in the linear motion guide device 10, the shape of each linear groove 11 a of the shaft body 11 is the radius of the columnar body 12 in a cross section cut along a direction perpendicular to the central axis of the shaft body 11. than R ₁ have a shape of a circular arc 19 with a large radius R _2, and the center O ₁ of the circular arc 19, the center O ₂ of the columnar body 12, and the center O ₃ of the shaft body 11 in a straight line The main characteristic is that they are set so as to line up (on the straight line L).

  The shaft body 11 is accommodated in the outer cylinder 13 via a plurality of columnar bodies 12 accommodated in the respective linear grooves 11a, and is guided in the lengthwise direction by being guided by the plurality of columnar bodies 12. A linear movement (sliding) is possible. The shaft body 11 is also in a non-rotating state (a state in which relative rotational movement with respect to the outer cylinder 13 is prevented) due to the engagement between the linear grooves 11 a and the columnar bodies 12. However, in the linear motion guide device 10 of the present invention, as described below, the shaft body 11 can be slightly rotated relative to the outer cylinder 13 (slightly rotated in the circumferential direction). ing.

As described above, when the shape of each linear groove 11 a of the shaft body 11 is the shape of the arc 19 having a radius R ₂ larger than the radius R _{1 of the} columnar body 12, each columnar body 12 corresponds to the shaft body 11. Line contact is made with the inner surface of the linear groove 11a. The shaft body 11 is in a state in which a load is applied in a direction from each columnar body 12 sandwiched between the outer cylinder 13 and the shaft body 11 toward the center O _{3 of the} shaft body 11. The body 11 is tightly supported by the plurality of columnar bodies 12 with almost no load applied in the circumferential direction.

Therefore, when a load is applied to the shaft body 11 in the circumferential direction, the radius R ₂ of the arc 19 of each linear groove 11a of the shaft body 11 is larger than the radius R ₁ of the columnar body 12, Since a slight gap is formed between the two, the shaft body 11 can be slightly rotated (slightly rotated) in the circumferential direction. However, when the rotational movement of the shaft body 11 progresses (when the angle of the rotational movement of the shaft body 11 increases), the shaft body 11 is further engaged by the engagement between the linear grooves 11a of the shaft body 11 and the columnar bodies 12. The rotational movement is prevented. When the application of the load to the shaft body 11 is stopped, the shaft body 11 is the direction of the fine rotation so that each columnar body 12 is arranged at a position where the depth of each linear groove 11a is maximum. A slight rotation in the reverse direction returns to the initial position shown in FIG.

A large load may be momentarily applied to the shaft body of the linear motion guide device in the circumferential direction.
For example, the shaft body of a linear motion guide device incorporated in an electronic component mounting device has a circumferential direction when the outer cylinder is rotated and moved together with the shaft body at a high speed (with a large acceleration) in order to rotate the electronic component. A large load may be momentarily applied to the. In addition, for example, when external vibration (eg, vibration generated by a driving device that linearly moves or rotationally moves the shaft body at high speed in the electronic component device apparatus) is applied to the shaft body, A load may be momentarily applied in the circumferential direction.

  In the linear motion guide device 10 of the present invention, for example, when a large load is momentarily applied to the linearly moving shaft body 11 in the circumferential direction, the shaft body 11 is slightly rotated. Accordingly, an increase in friction between the shaft body 11 and the columnar body 12 based on the above is suppressed, and therefore, wear of the shaft body 11 and the columnar body 12 is suppressed. For this reason, the linear guide apparatus 10 of the present invention exhibits excellent durability.

  Further, the linear motion guide device 10 of the present invention does not need to further form a round groove in each linear groove 11a of the shaft body 11, but has a complicated structure for forming a circular circulation path, a holding plate, and a taper give. Therefore, since it is not necessary to divide the outer cylinder into two parts, its manufacture is extremely easy.

  Therefore, the linear motion guide device of the present invention can be used particularly advantageously as a component that constitutes an electronic component mounting device in which the rotational movement and linear movement of the shaft body at high speed are repeated.

Radius R ₂ of the arc 19 of the linear groove 11a of the shaft 11, to be in the range of 1.01 to 1.4 times the radius R ₁ of the columnar body 12 (particularly from 1.02 to 1.2-fold) preferable. As a result, the shaft body 11 can be finely rotated, and the accuracy of linear movement of the shaft body 11 can be improved. In FIG. 2, the arc 19 of the linear groove 11a is shown with a radius larger than the actual radius so that the shape of the linear groove 11a of the shaft 11 can be easily understood. In the linear motion guide device 10 shown in FIGS. 1 and 2, the radius R ₂ of the arc 19 of the linear groove 11 a of the shaft body 11 is actually set to 1.04 times the radius R ₁ of the columnar body 12. .

  The depth of the linear groove 11a of the shaft body 11 is 5 to 40% of the diameter of the columnar body 12 in order to ensure prevention of the rotational movement of the shaft body 11 (a large rotational movement exceeding the fine rotation) (preferably Is preferably in the range of 10 to 40%).

  The “arc shape” used in this specification does not mean only a strict arc shape. When the straight groove is not in the shape of a strict arc, the “arc shape having a radius larger than the radius of the columnar body” used in the present specification means “a radius of curvature larger than the radius of the columnar body”. Or “a shape formed from two or more curves”. And, “the setting that the center of the arc, the center of the columnar body, and the center of the shaft are aligned in a straight line” is “the position where the depth of the linear groove is greatest in the width direction of the linear groove” , “A setting in which the center of the columnar body and the center of the shaft body are aligned in a straight line”. Thus, even when the linear groove is not in the shape of a strict arc, the same fine rotation of the shaft body as described above can be realized.

  The number of linear grooves of the shaft body 11 is preferably 3 or more. The number of linear grooves is more preferably in the range of 3 to 10, and particularly preferably in the range of 3 to 8. When the number of linear grooves is three or more, the shaft body is stably supported by a plurality of columnar bodies accommodated in each linear groove. Further, when the number of linear grooves is 10 or less, the shaft body can be easily manufactured. The plurality of linear grooves of the shaft body are preferably formed at equal intervals on the outer peripheral surface of the shaft body. In addition, a plurality of (for example, 2 to 10) columnar bodies can be accommodated in each linear groove of the shaft body side by side in the length direction of the linear groove.

  A through hole may be formed on the central axis of the shaft body 11. By exhausting the gas inside the through hole from one end of the shaft body, the electronic component is sucked into the opening at the other end of the shaft body (or the suction nozzle of the electronic component connected to the opening). Can be made.

  A plurality of linear grooves 13 a for accommodating the respective columnar bodies 12 are provided on the inner peripheral surface of the outer cylinder 13 of the linear guide apparatus 10 shown in FIGS. 1 and 2. Further, a pair of circumferential grooves 13c are formed on the inner circumferential surface of the outer cylinder 13 with a space between each other, and an annular stopper (e.g., publicly known) in a state where the outer circumferential portion is fitted in each circumferential groove 13c. ) 14, and the columnar bodies 12 are arranged between the inner peripheral portions of the annular stoppers 14.

  By adopting such a configuration, each columnar body 12 disposed between the outer cylinder 13 and the shaft body 11 cannot move relative to the outer cylinder 13. For this reason, jumping out from the end of the outer cylinder 13 of each columnar body 12 is prevented.

  However, each columnar body 12 can be rotationally moved in the circumferential direction. For this reason, each columnar body 12 slightly rotates in the circumferential direction under the influence of a change in the direction and magnitude of the load applied to the columnar body 12 when the linear motion guide device 10 is used or an external vibration. In particular, in the linear motion guide device 10 of the present invention, the fine rotation generated in the shaft body 11 as described above dramatically promotes the fine rotation of each columnar body 12. Thereby, since the extremely uniform wear of the outer peripheral surface of each columnar body 12 is realized, the durability of the linear motion guide device 10 becomes particularly good.

  Each linear groove 13a of the outer cylinder 13 is also in the shape of an arc having a radius larger than the radius of the columnar body 12, like the linear grooves 11a of the shaft body 11, and the center of the arc is on the straight line (see FIG. 2 is preferably on the straight line L shown in FIG. A preferable aspect regarding the depth, number, or arrangement of the linear grooves 13a of the outer cylinder 13 is the same as that of the linear grooves 11a of the shaft body 11.

  In addition, when the columnar body 12 is fixed to the outer cylinder 13 directly or indirectly via another part (for example, an annular stopper 14), the straight line is formed on the inner peripheral surface of the outer cylinder 13. The groove 13a may not be provided.

  In the linear motion guide device 10 shown in FIGS. 1 and 2, a known linear motion guide for circulating and moving a plurality of spheres supporting the shaft body between the outer tube and the shaft body as the outer tube 13. By using the outer cylinder of the apparatus as it is, further simplification of the production is realized. The plurality of linear grooves 13b included in the outer cylinder 13 are used to form the trajectory of the sphere, and are not used in the present invention.

  The material forming each of the shaft body 11, the columnar body 12, the outer cylinder 13, and the annular stopper 14 constituting the linear motion guide device 10 of the present invention is the same as in the case of a known linear motion guide device, Examples thereof include metal materials typified by steel, resin materials, and ceramic materials. If all of the shaft body 11, the columnar body 12, the outer cylinder 13, and the annular stopper 14 are formed of a metal material, the rigidity of the linear motion guide device 10 is increased and the heat resistance is also improved.

  FIG. 3 is a cross-sectional view showing another configuration example of the linear motion guide device of the present invention, and FIG. 4 shows a linear motion guide device 30 cut along the cutting line IV-IV written in FIG. It is sectional drawing.

  The configuration of the linear motion guide device 30 shown in FIGS. 3 and 4 is the same as that of the linear motion guide device 10 shown in FIGS. 1 and 2 except that the shape of the outer cylinder 33 is different.

  The linear motion guide device 30 is easy to manufacture because the outer cylinder 33 has a simple shape in which the outer peripheral edge and the inner peripheral edge of the cross section are circular and a plurality of linear grooves 33a are formed on the inner peripheral surface. It is.

10,30 radius R ₂ linear groove of the linear guide apparatus 11 the shaft body 11a linear groove 12 the column 13 the outer cylinder 13a, 13b straight grooves 13c circumferential groove 14 annular stop 19 arc 33 the outer tube 33a linear grooves R ₁ pillar The radius of the arc of O ₁ The center of the arc of the straight groove O ₂ The center of the columnar body O The center of the _3- axis body L Straight

Claims (5)

A cross section in which a plurality of linear grooves extending in the length direction on the outer peripheral surface are formed at intervals in the circumferential direction is a circular shaft body, and the cross section is accommodated in each linear groove of the shaft body. A linear guide device comprising a columnar body extending in the length direction of the linear groove, and an outer cylinder that slidably accommodates a shaft body through the columnar body in a non-rotating manner,
In a cross section cut along a direction perpendicular to the central axis of the shaft body, the shape of each linear groove of the shaft body is an arc shape having a radius larger than the radius of the columnar body, and A linear motion guide device characterized in that the center, the center of a columnar body, and the center of a shaft body are set so as to be aligned.   The linear motion guide device according to claim 1, wherein the radius of the arc of the straight groove is within a range of 1.01 to 1.4 times the radius of the columnar body.   The linear motion guide device according to claim 1, wherein the number of linear grooves of the shaft body is three or more.   The linear motion guide device according to any one of claims 1 to 3, wherein a plurality of linear grooves that respectively accommodate the columnar bodies are provided on an inner peripheral surface of the outer cylinder.   A pair of circumferential grooves are formed on the inner circumferential surface of the outer cylinder with a space between each other, and an annular stopper is provided in a state in which the outer circumferential portion is fitted to each circumferential groove, and both annular stoppers are provided. The linear motion guide device according to claim 4, wherein the columnar bodies are arranged between inner peripheral portions of the tool.

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