JP4089613B2 - Overhead traveling car - Google Patents

Description

  The present invention relates to an overhead traveling vehicle, and more particularly to prevention of vibration of a transported article in an overhead traveling vehicle.

  The overhead traveling vehicle travels along a traveling rail provided at a high place such as near the ceiling, and conveys articles. For example, a cover is provided on the front and back of the overhead traveling vehicle, and a vibration preventing member is advanced from the cover to support the four corners of the conveyed article, thereby suppressing vibration of the article. Here, Patent Document 1 discloses that the vibration preventing member of the overhead traveling vehicle is advanced and retracted using a parallel link. FIG. 5 shows the vibration preventing mechanism 110 of Patent Document 1. The cassette 52 is held by an upper flange 54 by a chuck (not shown). The vibration prevention mechanism 110 uses a parallel link, and the support portion advances to the bottom of the cassette 52 by the parallel link. At this time, the friction piece 112 of the vibration prevention member contacts and presses the side surface of the cassette 52, and the cassette The vibration of 52 is suppressed.

The inventors then found the following with the mechanism of FIG. Since the friction piece 112 presses the cassette 52 from one direction, the cassette 52 receives a horizontal force from the four friction pieces 112. However, since the cassette 52 is supported by the friction piece 112 during traveling, vibration is unlikely to occur. However, when the friction piece 112 is moved backward to transfer the cassette, the cassette 52 is vibrated.
JP 2003-165687 A

An object of the present invention is to suppress vibration after the vibration preventing member is separated from the conveyed article .
An additional object of the present invention is to provide a simple vibration preventing mechanism.
An additional object of the present invention is to prevent rubbing against the article when the vibration preventing member is advanced or retracted.

The overhead traveling vehicle of the present invention is an overhead traveling vehicle that grips an article and supports the four corners of the lower part of the article with a vibration preventing member to suppress vibration of the article during traveling.
A rotating piece that is rotatable in a horizontal plane is provided at the four lower corners of the article, and a vibration preventing member is attached to each rotating piece,
By turning the rotation pieces at the four corners into pairs of two adjacent corners, the anti-vibration members at the two corners of each pair are horizontally rotated in opposite directions to move away from the lower part of the article. The corner vibration preventing member is provided symmetrically with respect to the center of the article in a plan view, and is provided with an exit / withdrawing means for exiting and retracting the lower part of the article,
Further, the vibration prevention member is supported in contact with the lower part of the side surface of the article while the line connecting the rotation center of each rotation piece and the vibration prevention member is oblique to the side surface of the article. Features.

In the present invention, the vibration preventing member supports the lower four corners of the article symmetrically with respect to the center of the article in plan view. For this reason, the force applied to the article from the vibration preventing member is offset between the two vibration preventing members along the diagonal direction of the article, and the article is supported by being shifted from the stable position by the force from the vibration preventing member. There is no. Accordingly, when the vibration preventing member is separated from the article, the position of the article is a stable position, and the vibration of the article after the vibration preventing member is released can be suppressed .

In the present invention, since the vibration preventing member is attached to the rotating piece that rotates horizontally, the rotating piece can be accommodated in the overhead traveling vehicle compactly, unlike the rotation in the vertical plane. If the turning direction of the turning piece is opposite to each other at the left and right or front and rear two pairs of the overhead traveling vehicle, the four corners of the article can be easily supported symmetrically with respect to the center of the article in plan view.

In this invention, the vibration preventing member is supported in contact with the lower part of the side surface of the article, where the line connecting the vibration preventing member and the rotation center of the rotating piece is oblique with respect to the side surface of the article. To support. Then, when the vibration preventing member is rotated and brought into contact with the side surface of the article, the vibration preventing member does not rub against the side surface of the article. For this reason, it is possible to prevent the vibration preventing member and the article from being worn, or the accompanying dust generation.

  In the following, an optimum embodiment for carrying out the present invention will be shown.

  1 to 4 show examples and their characteristics. FIG. 1 shows the relationship between the traveling rail 2 and the power supply rails 5 and 6 and the overhead traveling vehicle 7. The traveling rail 2 is suspended from the ceiling of a clean room by suspension bolts 4 or the like, and left and right power supply rails 5 and 6 are attached to the lower portion of the traveling rail 2 by, for example, fitting. The overhead traveling vehicle 7 includes a traveling unit 8, a power feeding unit 10, and an overhead traveling vehicle main body 14, and the overhead traveling vehicle main body 14 includes a lateral feed unit 16, a lifting drive unit 18, and a lifting platform 20. Then, the lateral feed unit 16 laterally feeds the elevator drive unit 18 and the elevator platform 20 in a direction perpendicular to the traveling rail 2, the elevator drive unit 18 moves the elevator table 20 up and down, and the elevator platform 20 rotates in a horizontal plane. Let The lifting platform 20 conveys a conveyance article such as a cassette 52 such as a semiconductor by chucking it at the bottom of the flange 54, for example. Reference numeral 56 denotes a flange on the side of the cassette 52.

  For example, the traveling unit 8 is provided with a pair of left and right traveling wheels 22 and 22, and the upper portion is provided with a pair of left and right guide rollers 24 and 24, and branch rollers 25 and 26 are provided on both outer sides thereof. To guide. The branching rollers 25 and 26 can be moved up and down by an elevating unit 30 and are moved up and down between a position guided by the guide rail 28 and a position not guided, thereby controlling branching and straight traveling at the branching unit. Reference numeral 32 denotes a fixed shaft fixed to the overhead traveling vehicle main body 14, which transmits the weight of the overhead traveling vehicle main body 14 to the traveling unit 8, and a rotating shaft 34 that is coaxial with this is attached to the traveling unit 8. Extend down from the opening. The rotation shaft 34 rotates together with the axis of the traveling wheel 22. Further, the fixed shaft 32 and the traveling unit 8 are rotatably connected by the bearing 36.

  In the power feeding unit 10, there are power receiving units 12 and 12 on the left and right of the rotating shaft 34. For example, a magnetic core 38 having an E-shaped cross section is provided, and power is received by a power receiving coil 40. The power supply for the overhead traveling vehicle 7 is used. For example, a pair of upper and lower litz wires 44 serving as a power supply line and a communication line are arranged on the power supply rails 5 and 6, and the upper and lower litz wires 44 and 44 are looped. A dog 46 is provided on the heel side (outside in the left-right direction) of the upper and lower litz wires 44, 44 for teaching the stop position and the like.

  A linear sensor 48 is provided, for example, on the overhead traveling vehicle main body 14 and the like, and its principle is well known. Reference numeral 50 denotes a plate to be detected, which is composed of a plate such as a magnetic material or a diamagnetic material, and is attached to the traveling rail 2 or the like and passes through the linear sensor 48. Then, the detected plate 50 is separated from the litz wire 44 as much as possible to reduce the noise of the linear sensor 48. The linear sensor 48 detects the position with respect to the plate 50 to be detected. If the position of the plate 50 to be detected is known, the absolute position of the overhead traveling vehicle 7 is found.

  Reference numeral 60 denotes a fall prevention cover, for example, a pair provided on the front and rear of the overhead traveling vehicle 7, but a pair may be provided on the left and right instead of the front and rear. At the lower part of each of the front and rear fall prevention covers 60, there are left and right turning pieces 62, 63, which turn in the horizontal plane and drop to the lower side of the cassette 52 by the support portion 64. To prevent. Preferably, a slight gap is provided between the support portion 64 and the bottom surface of the cassette 52. Further, a friction piece 66 using an elastic member such as rubber is provided at a step portion in the vertical direction of the rotating pieces 62 and 63, which is an example of a vibration preventing member. The friction pieces 66 come into contact with the four corners at the lower side of the cassette 52 to prevent the cassette 52 from vibrating.

  2 and 3 show the horizontal turning mechanism of the turning pieces 62 and 63. FIG. Reference numeral 68 denotes a disk which can be rotated in a horizontal plane around a shaft 69, for example. Reference numerals 70 and 71 denote cranks having one end rotatably attached to the disk 68, and the other ends of the cranks 70 and 71 are attached to the rotary pieces 62 and 63 by shafts 72 and 73, respectively. The rotating pieces 62 and 63 are freely rotatable in a horizontal plane via a shaft 74. The mounting plate 76 fixed to the fall prevention cover 60 rotates the disk 68 by fixing the actuator 78 for rotating the disk 68 and the shaft 69 of the disk 68 so as not to rotate. Install the brake 80 to be prohibited. That is, the disk 68 is horizontally rotated by the actuator 78, the disk 68 is fixed by the brake 80, and the rotating pieces 62 and 63 are also fixed. As shown in FIG. 3, the flange 54 at the upper part of the cassette 52 is supported on the lifting platform by a chuck 82.

  When the friction piece 66 comes into contact with the cassette 52, the line connecting the friction piece 66 and the shaft 74 is inclined with respect to the side surface of the cassette 52, and this angle θ is set to 15 ° to 45 °, for example. In other words, the friction piece 66 has an offset D in the left-right direction with respect to a line extending perpendicularly from the shaft 74 to the side surface of the cassette 52, so that the friction piece 66 contacts obliquely when contacting the side surface of the cassette 52. There is no rubbing.

  The operation of the embodiment will be described. The elevator and the cassette 52 are chucked, and the elevator is raised by the elevator drive unit. Next, when the disk 68 is rotated by the actuator 78, the rotating pieces 62 and 63 are horizontally rotated from the state hidden in the fall prevention cover 60, and the support portion 64 is rotated to the lower side of the bottom surface of the cassette 52. To do. At this time, there is a gap between the bottom surface of the cassette 52 and the support portion 64. The rotating pieces 62 and 63 are bent downward from a height near the attachment portion to the shaft 74 through a step in the vertical direction and connected to the support portion 64. Then, there is a friction piece 66 at the stepped portion, and the friction piece 66 rotates and contacts the four corners at the lower side of the cassette 52 to prevent vibration.

  Here, since the fall prevention covers 60 are respectively provided at the front and rear of the overhead traveling vehicle, the rotary pieces 62 and 63 are located at four positions on the front, rear, left and right of the lower part of the cassette 52, and are symmetrical in the horizontal plane with respect to the center of the cassette 52 in plan view. And the four parts at the lower side of the cassette 52 are supported by the friction pieces 66. The direction in which the friction piece 66 contacts the cassette 52 is outward from the side surface of the cassette 52 in a plan view, and the force applied to the cassette 52 from the friction piece 66 cancels out as a whole, and no moment of force is generated. Is supported by the friction piece 66 in its original stable position. Therefore, when the friction piece 66 moves away from the cassette 52, the cassette 52 remains stable at that position and no vibration occurs.

  FIG. 4 shows a vibration preventing mechanism 90, 100 according to a modified example. In the vibration preventing mechanism 90, a friction piece 66 is attached to each of the left and right members 62 ′, 63 ′, and these are paired to the left and right to move forward and backward by an appropriate forward / backward moving mechanism. The four corners of the lower side of the cassette 52 are supported. In the vibration preventing mechanism 100, the rotating pieces 62 and 63 are horizontally rotated between the broken line position and the solid line position in FIG. 4, and the friction piece 66 is brought into contact with the four corners at the lower side of the cassette 52. Also in the case of the vibration preventing mechanism 100 of FIG. 4, the left and right rotating pieces 62 and 63 can be rotated by one actuator as in the mechanisms of FIGS. In any case, the forces acting on the cassette 52 from the friction pieces 66 at the four corners are symmetrical with respect to the center of the cassette 52 in plan view, cancel each other, and no moment of force for rotating the article is generated.

In the embodiment, the following effects can be obtained.
(1) Since the friction pieces are in contact with the four corners at the lower side of the cassette symmetrically with respect to the center of the cassette in a plan view and in opposite directions with the left and right friction pieces, the forces applied to the cassette from the friction pieces cancel each other. For this reason, vibration hardly occurs when the friction piece is separated from the cassette.
(2) Two rotating pieces can be driven by one actuator or one brake. The operation of the rotating piece is compact because it is horizontally rotated. Further, since a parallel link or the like is not used, the configuration is easy.
(3) Since the friction piece can be moved in and out without rubbing the side of the cassette, there is little dust generation, wear, and contamination of the cassette.
(4) In the unlikely event that the cassette chuck is removed, the cassette can be prevented from dropping at the support part at the bottom of the cassette.

Cross-sectional view of the main part showing the overhead traveling vehicle, the traveling rail, and the power supply rail used in the examples. Horizontal cross-sectional view of the main part of the fall prevention cover in the embodiment Vertical sectional view of the main part of the vibration prevention mechanism and the surrounding fall prevention cover in the embodiment The figure which shows typically the motion of the friction piece in an Example and a modification. The figure which shows typically the motion of the friction piece in the vibration prevention mechanism of a prior art example

Explanation of symbols

2 traveling rail 4 suspension bolt 5, 6 feeding rail 7 overhead traveling vehicle 8 traveling unit 10 power feeding unit 11 communication unit 12 power receiving unit 14 overhead traveling vehicle main body 16 lateral feeding unit 18 lifting drive unit 20 lifting platform 22 traveling wheel 24 guide roller 25 , 26 Branch roller 28 Guide rail 30 Lifting section 32 Fixed shaft 34 Rotating shaft 36 Bearing 38 Magnetic core 40 Power receiving coil 42 Substrate 44 Litz wire 46 Dog 48 Linear sensor 50 Detected plate 52 Cassette 54, 56 Flange 60 Fall prevention Cover 62, 63 Rotating piece 64 Support portion 66 Friction piece 68 Disk 69 Shaft 70, 71 Crank 72-74 Shaft 76 Mounting plate 78 Actuator 80 Brake 82 Chuck 90, 100 Vibration prevention mechanism 110 Vibration prevention mechanism 112 Friction piece

Claims (1)

In the overhead traveling vehicle that grips the article and supports the four corners of the lower part of the article with a vibration preventing member to suppress the vibration of the article while traveling,
A rotating piece that is rotatable in a horizontal plane is provided at the four lower corners of the article, and a vibration preventing member is attached to each rotating piece,
By turning the rotation pieces at the four corners into pairs of two adjacent corners, the anti-vibration members at the two corners of each pair are horizontally rotated in opposite directions to move away from the lower part of the article. The corner vibration preventing member is provided symmetrically with respect to the center of the article in a plan view, and is provided with an exit / withdrawing means for exiting and retracting the lower part of the article,
Further, the vibration prevention member is supported in contact with the lower part of the side surface of the article while the line connecting the rotation center of each rotation piece and the vibration prevention member is oblique to the side surface of the article. A featured overhead traveling vehicle.

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