JP7816638B2 - Ceiling transport vehicle - Google Patents

Description

This disclosure relates to an overhead transport vehicle.

As an example of technology related to overhead transport vehicles, Patent Document 1 describes a transport vehicle equipped with a running section (running carriage) that runs along a track section, a main body section suspended from the running section, and a loading section (transfer device) that can move forward and backward from the main body section in a horizontal direction. The transport vehicle described in Patent Document 1 has outrigger sections that can move toward the track section on the surface of the main body section facing the track section.

JP 2009-12916 A

However, with overhead transport vehicles, when the transfer device is advanced from the main body in a horizontal direction, for example, when transferring an item, the attitude of the transfer device may unintentionally change due to the influence of the transfer device's own weight, etc. In this regard, the technology mentioned above attempts to suppress changes in the attitude of the transfer device using outriggers, but there is still room for improvement. Furthermore, with user demands for vibration, for example, becoming increasingly strict in recent years, there is also a demand for suppressing vibration in the main body while the vehicle is traveling.

Therefore, the present disclosure aims to provide an overhead transport vehicle that can suppress vibration of the main body during travel and adjust the posture of the main body during transfer.

(1) The ceiling transport vehicle disclosed herein is an ceiling transport vehicle comprising a traveling carriage that travels along a track, a main body unit suspended from the traveling carriage, and a transfer device that can move forward and backward from the main body unit in a forward and backward direction along the horizontal direction, wherein the main body unit is rotatably attached to the traveling carriage via a horizontal rotation axis that is perpendicular to the forward and backward direction, and comprises an elastic unit interposed between the traveling carriage and the main body unit that maintains the attitude of the main body unit relative to the traveling carriage in the rotation direction around the horizontal rotation axis, and an adjustment unit provided on the main body unit that adjusts the amount of rotation of the main body unit relative to the traveling carriage in the rotation direction against the elastic force of the elastic unit.

In this overhead transport vehicle, an elastic section interposed between the traveling carriage and the main body section allows the posture of the main body section relative to the traveling carriage to be maintained while traveling, and vibrations transmitted from the traveling carriage to the main body section to be suppressed. Furthermore, during transfer, the adjustment section adjusts the amount of rotation of the main body section relative to the traveling carriage in the direction of rotation around the horizontal rotation axis, thereby adjusting the posture of the transfer device. Therefore, it is possible to suppress vibrations of the main body section while traveling, and adjust the posture of the main body section during transfer.

(2) In the ceiling transport vehicle described in (1) above, if the direction in which the transfer device protrudes from the main body is defined as the advance direction among the advance and retreat directions, and the direction opposite to the advance direction is defined as the retreat direction, the adjustment unit may be positioned on the retreat direction side of the horizontal rotation axis of the main body, protrude upward, the amount of protrusion is adjustable, and have a protrusion that can abut against the track from below. In this case, the posture of the transfer device can be easily adjusted by the protrusion.

(3) In the ceiling transport vehicle described in (2) above, the adjustment unit is positioned further forward than the horizontal rotation axis of the main body unit, protrudes upward and is configured so that the amount of protrusion is adjustable, and has another protrusion that can abut against the track from below, and when the protrusion unit and the other protrusion unit protrude until they abut against the track, the amount of protrusion of the other protrusion unit may be smaller than the amount of protrusion of the protrusion unit. In this case, the other protrusion unit can further stabilize the posture of the transfer device and suppress unintended shaking of the main body unit.

(4) In the overhead transport vehicle described in any one of (1) to (3) above, a bushing formed of an elastic body that is deformable in the radial direction of the horizontal rotation shaft may be provided around the horizontal rotation shaft. In this case, vibrations transmitted from the traveling carriage to the main body can be further suppressed.

(5) The ceiling transport vehicle described in any one of (1) to (4) above is equipped with a control unit that controls the adjustment unit, and the control unit stores the amount of rotation by the adjustment unit in advance associated with each of multiple placement units that are the transfer destination or transfer source of the transfer device, and the control unit may control the operation of the adjustment unit so that when the transfer device moves forward or backward in the forward/backward direction to transfer an item between one of the multiple placement units and the transfer device, the amount of rotation is the amount associated with the one placement unit. In this case, when performing lateral transfer to the multiple placement units, the attitude of the transfer device can be adjusted according to the state of each of the multiple placement units.

This disclosure makes it possible to provide an overhead transport vehicle that can suppress vibration of the main body during travel and adjust the posture of the main body during transfer.

FIG. 1 is a side view showing an overhead transport vehicle according to an embodiment. FIG. 2 is a rear view of the ceiling transport vehicle of FIG. FIG. 3 is a partial cross-sectional view taken along line III-III in FIG. FIG. 4 is a partial cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a rear view illustrating an example of the operation of the adjustment unit in the ceiling transport vehicle of FIG. FIG. 6 is a rear view showing a continuation of FIG.

The following describes the embodiments in detail with reference to the drawings. In the description of the drawings, identical elements are given the same reference numerals and duplicate explanations are omitted.

As shown in FIG. 1, the ceiling transport vehicle 1 travels along a track 20 installed near the ceiling of a clean room where semiconductor devices are manufactured. The ceiling transport vehicle 1 transports items 200, such as FOUPs (Front Opening Unified Pods) containing multiple semiconductor wafers, and transfers the items 200 to load ports (mounting sections) installed in processing equipment that performs various processes on the semiconductor wafers. The items 200 may be containers that store multiple semiconductor wafers, containers that store glass substrates, reticle pods, general parts, etc. The track 20 forms the travel path of the ceiling transport vehicle 1.

The overhead transport vehicle 1 comprises a frame unit (main body) 2, a traveling carriage 3, a lateral unit 4, a theta unit 5, a lifting drive unit 6, a holding unit (transfer device) 7, and a transport vehicle controller (control unit) 8. The frame unit 2 is suspended from the traveling carriage 3. The frame unit 2 has a center frame 15, a front frame 16, and a rear frame 17. The front frame 16 extends downward from the front end of the center frame 15 (the front end in the traveling direction of the overhead transport vehicle 1). The rear frame 17 extends downward from the rear end of the center frame 15 (the rear end in the traveling direction of the overhead transport vehicle 1).

The traveling carriage 3 is arranged above the center frame 15. The traveling carriage 3 travels along the track 20 by receiving a contactless supply of power, for example, from a high-frequency current line laid along the track 20. The lateral unit 4 is arranged below the center frame 15. The lateral unit 4 moves the theta unit 5, lifting drive unit 6, and holding unit 7 laterally (to the side, left and right, and horizontally in the direction of travel of the ceiling transport vehicle 1) relative to the frame unit 2. The theta unit 5 is arranged below the lateral unit 4. The theta unit 5 rotates the lifting drive unit 6 and holding unit 7 in a horizontal plane.

The lifting drive unit 6 is arranged below the theta unit 5. The lifting drive unit 6 raises and lowers the holding unit 7 by unwinding and winding multiple belts (hanging members) B connected to the holding unit 7. The holding unit 7 is arranged below the lifting drive unit 6. The holding unit 7 is arranged so that it can be raised and lowered by the lifting drive unit 6. The holding unit 7 has a pair of grippers 12 that can be opened and closed in the horizontal direction. The holding unit 7 holds the flange 201 of the item 200 with the pair of grippers 12. The holding unit 7 can be advanced and retreated from the frame unit 2 in the lateral direction (advancing and retreating direction along the horizontal direction) by the lateral unit 4.

The transport vehicle controller 8 is arranged on the center frame 15. The transport vehicle controller 8 is an electronic control unit composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The transport vehicle controller 8 controls each part of the ceiling transport vehicle 1. The transport vehicle controller 8 may be composed of multiple electronic control units. The transport vehicle controller 8 may also be arranged on the front frame 16, etc.

The overhead transport vehicle 1 configured as described above operates, for example, as follows during lateral transfer of an item 200 from a load port located laterally. At a stop position corresponding to the load port, the overhead transport vehicle 1 drives the lateral unit 4 to move the holding unit 7 in the forward direction relative to the frame unit 2. At the same time, if necessary, the theta unit 5 is driven to adjust the orientation of the holding unit 7. The forward direction is the lateral direction in which the holding unit 7 advances so as to protrude from the frame unit 2. Next, the overhead transport vehicle 1 drives the lifting drive unit 6 to lower the holding unit 7, thereby holding the flange 201 of the item 200 on the load port with the holding unit 7. The overhead transport vehicle 1 drives the lifting drive unit 6 to raise the holding unit 7 to the upper end. The overhead transport vehicle 1 then drives the lateral unit 4 to move the holding unit 7 in the retreat direction, which is the opposite direction to the forward direction, and positions the holding unit 7 between the front frame 16 and the rear frame 17.

On the other hand, when transferring an item 200 to a load port located laterally, the ceiling transport vehicle 1 operates, for example, as follows: At a stop position corresponding to the load port, the ceiling transport vehicle 1 drives the lateral unit 4 to move the holding unit 7 holding the item 200 in the forward direction relative to the frame unit 2. At the same time, if necessary, the theta unit 5 is driven to adjust the orientation of the holding unit 7. Next, the ceiling transport vehicle 1 drives the lifting drive unit 6 to lower the holding unit 7, placing the item 200 on the load port, and the holding unit 7 releases its hold on the flange 201 of the item 200. The ceiling transport vehicle 1 drives the lifting drive unit 6 to raise the holding unit 7 to the upper end. Then, the ceiling transport vehicle 1 drives the lateral unit 4 to move the holding unit 7 in the retreating direction, positioning the holding unit 7 between the front frame 16 and the rear frame 17.

In this embodiment, as shown in Figures 1, 3, and 4, the traveling carriage 3 has a suspension shaft 3F that suspends and supports the frame unit 2. The suspension shaft 3F is a cylindrical shaft that extends downward in the vertical direction at the bottom of the traveling carriage 3. A pair of suspension shafts 3F are arranged spaced apart in the fore-and-aft direction (travel direction) of the overhead transport vehicle 1. The suspension shafts 3F are also called bogie shafts.

The center frame 15 of the frame unit 2 is rotatably attached to the suspension axis 3F of the traveling carriage 3 via a horizontal rotation axis 41. Rotatable means that it can rotate in both directions of rotation (hereinafter simply referred to as the "rotation direction") around the horizontal rotation axis 41 as the base axis. The horizontal rotation axis 41 is a shaft with a circular cross section that is perpendicular to the forward/backward direction. The horizontal rotation axis 41 extends along the front-to-rear direction. The horizontal rotation axis 41 is also referred to as the rotation shaft. The horizontal rotation axis 41 is fixed to the center frame 15.

In the example shown in Figure 3, the center frame 15 has a pair of openings 15A aligned in the front-to-rear direction. The horizontal rotation shaft 41 is fixed to the center frame 15 so as to pass through the pair of openings 15A in the center frame 15 and be exposed from each of the pair of openings 15A. The horizontal rotation shaft 41 is rotatably attached to the suspension shaft 3F within each opening 15A. The horizontal rotation shaft 41 intersects with the suspension shaft 3F within each opening 15A. A cylindrical bushing 42 formed of an elastic body that is deformable in the radial direction of the horizontal rotation shaft 41 is provided around the horizontal rotation shaft 41. The horizontal rotation shaft 41 is connected to the suspension shaft 3F via the bushing 42.

The ceiling transport vehicle 1 includes an elastic portion 51 and an adjustment portion 52. The elastic portion 51 is interposed between the suspension shaft 3F of the traveling carriage 3 and the center frame 15 of the frame unit 2. Specifically, the elastic portion 51 is provided within each opening 15A, between one lateral side of the outer circumferential surface of the suspension shaft 3F and the inner wall surface of the opening 15A, and between the other lateral side of the outer circumferential surface of the suspension shaft 3F and the inner wall surface of the opening 15A. The elastic portion 51 and the inner wall surface of the opening 15A are bonded together, for example, with adhesive tape. The elastic portion 51 and the outer circumferential surface of the suspension shaft 3F are in contact with each other without being bonded together.

The elastic portion 51 maintains the position of the frame unit 2 relative to the traveling carriage 3 in the rotational direction. The elastic portion 51 applies an elastic force to the center frame 15 that prevents the center frame 15 from rotating around the horizontal rotation axis 41. The elastic portion 51 is made of an elastic body made of a high-hardness material (for example, an elastic body harder than the material of the bushing 42). The elastic portion 51 is also called a damper.

The adjustment portion 52 is provided on the frame unit 2. The adjustment portion 52 adjusts the amount of rotation of the frame unit 2 relative to the traveling carriage 3 in the rotational direction against the elastic force of the elastic portion 51. The adjustment portion 52 has a first protrusion 52A and a second protrusion 52B. As shown in Figures 2, 5, and 6, the first protrusion 52A is arranged on one lateral side of the horizontal rotation axis 41 on the center frame 15. The second protrusion 52B is arranged on one lateral side of the horizontal rotation axis 41 on the center frame 15.

The first protrusion 52A and the second protrusion 52B are provided in the central portion in the front-to-rear direction on the center frame 15. The first protrusion 52A and the second protrusion 52B protrude upward, and the amount of protrusion is adjustable. The first protrusion 52A and the second protrusion 52B are not particularly limited, but for example, a configuration is used in which rollers rise and fall from roller blocks due to the driving force of a motor. The first protrusion 52A and the second protrusion 52B can abut against the underside of the track 20 from below. The first protrusion 52A and the second protrusion 52B are also referred to as outrigger portions.

The first protrusion 52A and the second protrusion 52B each protrude by an appropriate amount, thereby bracing themselves against the underside of the track 20 and generating a rotational force (a rotational force greater than or equal to the elastic force of the elastic portion 51) that resists the elastic force of the elastic portion 51 in the rotational direction, thereby rotating the frame unit 2 in the rotational direction. The first protrusion 52A and the second protrusion 52B are connected to the transport vehicle controller 8.

The transport vehicle controller 8 controls the adjustment unit 52. The transport vehicle controller 8 stores the rotation amount by the adjustment unit 52 in advance as a rotation amount data table, associated with each of multiple load ports that are the transfer destination or source of the holding unit 7. The rotation amount in the rotation amount data table is teaching data for the rotation amount that enables the lateral unit 4 to move horizontally (without tilting relative to the horizontal direction) during lateral transfer.

When performing lateral transfer between one of multiple load ports, the transport vehicle controller 8 controls the operation of the adjustment unit 52 so that the rotation amount is the amount associated with that load port in the rotation amount data table. The rotation amount by the adjustment unit 52 can be adjusted using various known methods, for example, based on the positional relationship between the first protrusion 52A, the second protrusion 52B, and the horizontal rotation axis 41 on the frame unit 2. The rotation amount may be adjusted using only either the first protrusion 52A or the second protrusion 52B.

Next, an example of the operation of the adjustment unit 52 will be described. In the initial state shown in Figure 2, for example, when a lateral transfer command is received to transfer an item 200 to the right-hand load port in the lateral direction of the ceiling transport vehicle 1, the transport vehicle controller 8 controls the operation of the first protrusion 52A and the second protrusion 52B as follows.

That is, as shown in Figure 5, the first protrusion 52A, which is located further back than the horizontal rotation shaft 41 in the retreating direction, is caused to protrude upward until it abuts the underside of the track 20, and then the protrusion amount is increased. At the same time, the second protrusion 52B, which is located further forward than the horizontal rotation shaft 41, is caused to protrude upward until it abuts the underside of the track 20. In other words, when the first protrusion 52A and the second protrusion 52B have protruded until they abut against the track 20, the protrusion amount of the second protrusion 52B is made smaller than the protrusion amount of the first protrusion 52A. Note that the second protrusion 52B only needs to protrude so that it slightly contacts the track 20, and does not need to protrude at all.

As a result, the first protrusion 52A is strongly pushed between the underside of the track 20 and the center frame 15, generating a rotational force in the frame unit 2 that resists the elastic force of the elastic portion 51 in the rotational direction around the horizontal rotation axis 41. The frame unit 2 is rotated relative to the traveling carriage 3 in a direction such that the right side, which is the forward direction of the frame unit 2, rises (in other words, the left side, which is the backward direction, falls).

At this time, the rotation amount associated with the load port to which the item 200 is transferred is obtained from the rotation amount data table stored in the transport vehicle controller 8, and the protrusion amounts of the first protrusion 52A and the second protrusion 52B are controlled to achieve that rotation amount. As a result, as shown in Figure 6, only the frame unit 2 can be tilted, and when the lateral unit 4 is driven and the holding unit 7 is moved in the advancing direction relative to the frame unit 2, the lateral unit 4 moves straight along the horizontal direction, making it possible to keep the lateral unit 4 horizontal.

As described above, in the ceiling transport vehicle 1, the elastic part 51 interposed between the traveling carriage 3 and the frame unit 2 allows the orientation of the frame unit 2 relative to the traveling carriage 3 to be maintained during travel, and vibrations transmitted from the traveling carriage 3 to the frame unit 2 to be suppressed. Furthermore, during lateral transfer, the orientation of the holding unit 7 can be adjusted by adjusting the amount of rotation of the frame unit 2 relative to the traveling carriage 3 in the direction of rotation about the horizontal rotation axis 41 using the adjustment part 52. A mechanism can be added to prevent the lateral unit 4 from tilting during lateral transfer, making it possible to eliminate the need for an automatic optical axis adjustment mechanism for the sensor that detects the shaking of the holding unit 7 and the sensor that detects obstacles below which the holding unit 7 descends.

In the ceiling transport vehicle 1, the adjustment section 52 has a first protrusion 52A located laterally to one side (left side) of the horizontal rotation axis 41 in the frame unit 2. In this case, the first protrusion 52A makes it easy to adjust the posture of the holding unit 7 when transferring laterally between the load port on the other side (right side) in the horizontal direction.

In the ceiling transport vehicle 1, the adjustment unit 52 has a second protrusion 52B positioned laterally on the other side of the horizontal rotation axis 41 in the frame unit 2. When the first protrusion 52A and the second protrusion 52B protrude until they abut the track 20, the protrusion amount of the second protrusion 52B is smaller than the protrusion amount of the first protrusion 52A. In this case, when transferring laterally between the load port on the other side in the lateral direction, the second protrusion 52B can further stabilize the posture of the lateral unit 4 and the holding unit 7, thereby suppressing unintended shaking of the frame unit 2.

In the ceiling transport vehicle 1, a bushing 42 is provided around the horizontal rotation axis 41. In this case, vibrations transmitted from the traveling carriage 3 to the frame unit 2 can be further suppressed.

The ceiling transport vehicle 1 is equipped with a transport vehicle controller 8 that controls the adjustment unit 52. A rotation amount data table is stored in the transport vehicle controller 8, and when performing lateral transfer between one of multiple load ports, the transport vehicle controller 8 controls the operation of the adjustment unit 52 so that the amount of rotation associated with that load port is achieved based on the rotation amount data table. In this case, when performing lateral transfer between multiple load ports, the posture of the holding unit 7 can be adjusted according to the state of each of the multiple load ports.

In the above, when transferring laterally between a load port on the other lateral side (right side), the first protrusion 52A constitutes the protrusion, and the second protrusion 52B constitutes the other protrusion. Furthermore, when transferring laterally between a load port on one lateral side (left side), the second protrusion 52B constitutes the protrusion, and the first protrusion 52A constitutes the other protrusion.

Although the above describes an embodiment, one aspect of the present disclosure is not limited to the above embodiment.

In the above embodiment, the rotation amount (rotation amount data table) stored in the transport vehicle controller 8 may be teaching data regarding the rotation amount of the frame unit 2 in the rotation direction, and may be expressed, for example, as an angle, as the protrusion amount of the first protrusion 52A and the second protrusion 52B, or as the drive amount of the first protrusion 52A and the second protrusion 52B.

In the above embodiment, the amount of rotation stored in the transport vehicle controller 8 is not particularly limited, and may be further associated with at least one of the presence or absence of an item 200 being held, the type of item 200 being held, and the amount of movement (stroke amount) by the lateral unit 4. In the above embodiment, either the first or second protrusion 52A, 52B on the advancing direction side during lateral transfer does not need to abut the track 20 from below.

In the above embodiment, the elastic portion 51 and the inner wall surface of the opening 15A of the center frame 15 are bonded together with adhesive tape or the like, but they may be in contact without being bonded. In the above embodiment, the elastic portion 51 and the outer peripheral surface of the suspension shaft 3F are in contact without being bonded, but they may be bonded together with adhesive tape or the like.

The above embodiments and their respective configurations are not limited to the shapes described above, and various shapes can be applied. Some of the configurations in the above embodiments may be omitted as appropriate, provided that they do not deviate from the spirit of one aspect of the present invention.

1...ceiling transport vehicle, 2...frame unit (main body), 3...traveling cart, 7...holding unit (transfer device), 8...transport vehicle controller (control unit), 20...track, 41...horizontal rotation axis, 42...bush, 51...elastic part, 52...adjustment part, 52A...first protrusion (protrusion, other protrusion), 52B...second protrusion (protrusion, other protrusion), 200...article.

Claims (5)

An overhead transport vehicle comprising: a traveling carriage that travels along a track; a main body that is suspended and supported by the traveling carriage; and a transfer device that can advance and retreat from the main body in a forward and backward direction along a horizontal direction,
the main body is attached to the traveling carriage so as to be rotatable via a horizontal rotation axis perpendicular to the forward/backward direction,
an elastic portion interposed between the traveling carriage and the main body portion and configured to maintain the attitude of the main body portion relative to the traveling carriage in the rotation direction around the horizontal rotation axis;
An adjustment unit provided on the main body portion that adjusts the amount of rotation of the main body portion relative to the traveling carriage in the rotation direction against the elastic force of the elastic unit. In the advancing and retracting directions, the direction in which the transfer device protrudes from the main body is defined as an advancing direction, and the direction opposite to the advancing direction is defined as a retreating direction,
The adjustment unit
2. The ceiling transport vehicle of claim 1, further comprising a protrusion that is positioned on the withdrawal direction side of the horizontal rotation axis of the main body, protrudes upward, the amount of protrusion is adjustable, and is capable of contacting the track from below. The adjustment unit
another protruding portion is disposed on the main body portion closer to the horizontal rotation axis in the advancement direction, protrudes upward, the protruding amount is adjustable, and is capable of contacting the track from below;
The overhead transport vehicle according to claim 2 , wherein when the protruding portion and the other protruding portion protrude until they abut against the track, the protruding amount of the other protruding portion is smaller than the protruding amount of the protruding portion. An overhead transport vehicle as described in claim 1 or 2, wherein a bush formed of an elastic body that can deform radially around the horizontal rotation shaft is provided around the horizontal rotation shaft. a control unit that controls the adjustment unit,
The control unit stores the rotation amount by the adjustment unit in advance in association with each of a plurality of placement units that are transfer destinations or transfer sources of the transfer device,
The control unit
A ceiling transport vehicle as described in claim 1 or 2, wherein when the transfer device is used to transfer an item between one of the plurality of loading sections and the transfer device is moved forward or backward in the forward/backward direction, the operation of the adjustment unit is controlled so that the rotation amount is associated with the one loading section.