JP2022177495A - Ceiling transport vehicle - Google Patents

Abstract

To provide a ceiling transport vehicle that can accurately detect oscillation of a holding unit.SOLUTION: A ceiling transport vehicle 1 includes: a holding unit 7 that is provided vertically movable and holds an FOUP 200; an elevation driving unit 6 that vertically moves the holding unit 7 by delivering and winding of multiple belts connected to the holding unit 7; a horizontally adjustment part 9 that adjusts the inclination of the holding unit 7 so that the holding unit 7 keeps the horizontal condition; an oscillation detection sensor 10 that is provided on the holding unit 7 and has its optic axis positioned facing upward and its light receiving surface facing upward; a reflection plate RL that is provided on the elevation driving unit and is positioned on an upper part of the oscillation detection sensor 10; and a transport vehicle controller 8 that detects the oscillation of the holding unit 7 based on the light receiving condition of the oscillation sensor 10.SELECTED DRAWING: Figure 1

Description

The present invention relates to an overhead transport vehicle.

As a technology related to the ceiling transport vehicle, for example, a transport vehicle described in Patent Document 1 is known. The transport vehicle described in Patent Document 1 includes a body portion, a lifting table (holding unit) having a holding portion for holding an article, an elevation drive unit that raises and lowers the lifting table by extending and winding a hanging member, A reflector provided on the top surface of the elevator, and a shake detection sensor provided in the elevator drive unit that irradiates the reflector downward with a laser beam and detects the shake of the elevator from the reflected light. . In the transport vehicle described in Patent Literature 1, an actuator is used to change the attitude of the shake detection sensor, thereby correcting the deviation of the irradiation direction of the laser light.

WO2017/199593

In the above-described ceiling guided vehicle, even if the holding unit is not shaking, for example, if the elevation drive unit is tilted, the shaking detection sensor cannot properly receive light and the shaking of the holding unit is erroneously detected. is still a concern.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an overhead transport vehicle capable of accurately detecting shaking of a holding unit.

An overhead transport vehicle according to the present invention includes a holding unit that is provided to be able to move up and down, and holds an article; a horizontal adjustment unit for adjusting the inclination of the holding unit so that the holding unit is maintained in a horizontal state; a light projector provided in the holding unit and arranged with the optical axis directed upward; , a light receiver arranged with the light receiving surface facing upward, a reflector provided in the elevation drive unit and arranged above the light emitter and the light receiver, and a holding unit based on the light receiving state of the light receiver and a first controller that detects the shaking of the

In this ceiling transport vehicle, a projector is provided in a holding unit that is maintained in a horizontal state by a leveling unit. Therefore, it is possible to prevent the optical axis of the projector from tilting along with the inclination of the holding unit, to keep the optical axis of the projector always pointing upward, and to prevent the optical axis of the projector from deviating from the reflector. can be suppressed. Therefore, for example, when the holding unit is not shaken, even if the up/down drive unit is tilted, the light from the projector is surely reflected by the reflector and received by the light receiver, resulting in erroneous detection of shaking of the holding unit. can be suppressed. That is, it is possible to accurately detect the shaking of the holding unit.

An overhead transport vehicle according to the present invention includes a holding unit that is provided to be able to move up and down, and holds an article; a horizontal adjustment unit for adjusting the inclination of the holding unit so that the holding unit is maintained in a horizontal state; a projector provided in the holding unit and arranged with its optical axis directed upward; A light receiver arranged with a light receiving surface facing downward, and a first controller detecting shaking of the holding unit based on the light receiving state of the light receiver are provided.

In this ceiling transport vehicle, a projector is provided in a holding unit that is maintained in a horizontal state by a leveling unit. Therefore, it is possible to prevent the optical axis of the projector from tilting along with the inclination of the holding unit, and to keep the optical axis of the projector always pointing upward, thereby preventing the optical axis of the projector from deviating from the receiver. can be suppressed. Therefore, for example, when the holding unit is not shaken, even if the elevation drive unit is tilted, the light from the light projector is reliably received by the light receiver, and erroneous detection of shaking of the holding unit can be suppressed. . That is, it is possible to accurately detect the shaking of the holding unit.

In the overhead transport vehicle according to the present invention, the horizontal adjustment section includes a guide roller around which the suspension member is wound, a body section for supporting the winding drum and the guide roller for winding and feeding the suspension member, and By moving the relative position of the guide roller, the holding unit is maintained in a horizontal state based on the position adjustment unit that moves the connecting part of the suspension member to the holding unit in the vertical direction, and the information on the inclination of the holding unit. and a second controller that controls movement of the guide roller by the position adjustment unit so as to perform the movement of the guide roller. In this case, it is possible to maintain the horizontal state of the holding unit with a relatively simple configuration.

According to the present invention, it is possible to provide an overhead transport vehicle capable of accurately detecting shaking of a holding unit.

FIG. 1 is a side view of an overhead transport vehicle of one embodiment. FIG. 2 is a front view of the holding unit. FIG. 3 is a perspective view of a first cushioning mechanism and a second cushioning mechanism. FIG. 4 is a front view of the lift drive unit. FIG. 5A is a front view showing the operation of the elevation drive unit. FIG. 5B is a front view showing another operation of the elevation drive unit. FIG. 6 is a front view for explaining the shake detection sensor during transfer of the overhead transport vehicle.

A preferred embodiment of one aspect of the present invention will be described in detail below with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

As shown in FIG. 1, an overhead transport vehicle 1 of one embodiment travels along a track 20 laid near the ceiling of a clean room where semiconductor devices are manufactured. The track 20 forms a travel path for the overhead transport vehicle 1 . The overhead transport vehicle 1 transports a FOUP (Front Opening Unified Pod) (article) 200 containing a plurality of semiconductor wafers, and loads the FOUP 200 to a load port 300 or the like provided in a processing apparatus for performing various processes on semiconductor wafers. Carry out transfer.

The ceiling transport vehicle 1 includes a frame unit 2, a traveling unit 3, a lateral unit 4, a sheeter unit 5, an elevation drive unit 6, a holding unit 7, and transport vehicle controllers (first controller and second controller) 8. and have. 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 side in the running direction of the overhead transport vehicle 1). The rear frame 17 extends downward from the rear end of the center frame 15 (the rear side in the running direction of the overhead transport vehicle 1).

The traveling unit 3 is arranged above the center frame 15 . The traveling unit 3 travels along the track 20 by being supplied with electric power in a non-contact manner from, for example, 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 sheeter unit 5, the lifting drive unit 6, and the holding unit 7 in the lateral direction (sideways in the traveling direction of the overhead transport vehicle 1). The theta unit 5 is arranged below the lateral unit 4 . The sheeter unit 5 rotates the elevation drive unit 6 and the holding unit 7 in the horizontal plane.

The elevation drive unit 6 is arranged below the sheeter unit 5 . The elevation drive unit 6 raises and lowers the holding unit 7 by extending and winding a plurality of belts (suspension members) B connected to the holding unit 7 . The holding unit 7 is arranged below the elevation drive unit 6 . The holding unit 7 is provided so as to be movable up and down by the elevation driving unit 6 . A holding unit 7 holds the flange 201 of the FOUP 200 .

The carrier controller 8 is arranged on the center frame 15 . The transport vehicle controller 8 is an electronic control unit including a CPU (Central Processing Unit), a ROM (Read only memory), a RAM (Random access memory), and the like. The transport vehicle controller 8 controls each part of the overhead transport vehicle 1 . The transport vehicle controller 8 may be composed of a plurality of electronic control units.

As an example, the ceiling guided vehicle 1 configured as described above operates as follows. When transferring the FOUP 200 from the load port 300 to the overhead transport vehicle 1 , the overhead transport vehicle 1 that does not hold the FOUP 200 stops at a predetermined position above the load port 300 . When the position in the horizontal plane of the holding unit 7 lowered at the stop position deviates from the predetermined position with respect to the load port 300 (the FOUP 200 placed on the load port 300), the lateral unit 4 and the theta unit 5 are driven. , to adjust the horizontal position and horizontal angle of the holding unit 7; Subsequently, the lift drive unit 6 lowers the holding unit 7 , and the holding unit 7 holds the flange 201 of the FOUP 200 placed on the load port 300 . Subsequently, the elevation drive unit 6 raises the holding unit 7 to the upper end to place the FOUP 200 between the front frame 16 and the rear frame 17 . Subsequently, the ceiling transport vehicle 1 holding the FOUP 200 starts traveling.

On the other hand, when transferring the FOUP 200 from the ceiling transport vehicle 1 to the load port 300 , the ceiling transport vehicle 1 holding the FOUP 200 stops at a predetermined position above the load port 300 . If the position in the horizontal plane of the holding unit 7 (FOUP 200) lowered at the stop position deviates from the predetermined position with respect to the load port 300, the lateral unit 4 and the theta unit 5 are driven to adjust the horizontal position and the horizontal position of the holding unit. adjust the angle. Subsequently, the lift drive unit 6 lowers the holding unit 7 to place the FOUP 200 on the load port 300 , and the holding unit 7 releases the holding of the flange 201 of the FOUP 200 . Subsequently, the elevation drive unit 6 raises the holding unit 7 to the raised end. Subsequently, the overhead transport vehicle 1 not holding the FOUP 200 starts running.

Next, the configuration of the holding unit 7 will be described in detail. As shown in FIGS. 1 and 2 , the holding unit 7 has a base 11 , a pair of grippers (holding portions) 12 and 12 and a housing 13 . A pair of grippers 12, 12 are supported by the base 11 so that they can be opened and closed along the horizontal direction. The pair of grippers 12, 12 are opened and closed by a drive motor (not shown) and a link mechanism (not shown). In the holding unit 7 , the base 11 constitutes the bottom wall of the housing 13 and is fixed in position relative to the housing 13 .

As shown in FIG. 3 , one end of the belt B is connected to the holding unit 7 of the present embodiment via a first buffer mechanism 50 and a second buffer mechanism 40 . The first damping mechanism 50 and the second damping mechanism 40 are mechanisms that connect the belt B and the holding unit 7 (see FIG. 1). It is a mechanism for suppressing transmission to the FOUP 200 .

The first cushioning mechanism 50 has an elastic member 58 that supports the base 11 vertically from below so as to be vertically movable. placed on one side. In this embodiment, the first buffer mechanism 50 is provided on the right side of the holding unit 7 in the left-right direction. The first buffer mechanism 50 has a connection member 51, a swing member 53, a first body member 54, a second body member 56, and a pair of elastic members 58,58.

The connecting member 51 is a member attached to the belt B. As shown in FIG. The swinging member 53 is a member connected to the connecting member 51 . The swinging member 53 is connected to the connecting member 51 via the pin member 52 so as to be bidirectionally rotatable. The first body member 54 is a substantially L-shaped member, and the bottom portion thereof is formed to be flat. The first body member 54 is connected to the swing member 53 at its upper end. The bottom of the first body member 54 is connected to the second body member 56 by bolts or the like. The second body member 56 supports the elastic member 58 from below and the bottom of the first body member 54 .

A pair of elastic members 58, 58 are coil springs having a predetermined spring constant. A pair of elastic members 58, 58 are supported by the second body member 56 and support the base 11 from below. A lower end of the elastic member 58 is fixed to the second body member 56 . The upper end of the elastic member 58 is not fixed to the base 11, but supports the base 11 by contact. That is, when each of the pair of elastic members 58 and 58 is in a contracted state in contact with both the second body member 56 and the base 11, each of the elastic members 58 and 58 moves away from the second body member 56 and the base 11 from each other. energize. The elastic member 58 has a role of reducing vibration transmitted between members in contact with each other. In addition, it may be fixed to the base 11 and provided to the second body member 56 so as to be separable and contactable.

The second cushioning mechanism 40 has an elastic member 48 that supports the base 11 vertically from below so as to be vertically movable. It is arranged on the other side (the side opposite to the first buffer mechanism 50 in the width direction). In this embodiment, the second buffer mechanism 40 is provided on the left side of the holding unit 7 in the left-right direction. The second buffer mechanism 40 has connection members 41, 41, a swing member 43, a third body member 45, a fourth body member 46, a regulation member 47, and a pair of elastic members 48, 48. is doing.

The connecting members 41, 41 are members to which the belts B, B are attached. The swinging member 43 is a member that connects the pair of connection members 41 and 41 and the third main body member 45 . The pair of connecting members 41 and 41 and the swinging member 43 are bidirectionally rotatably connected and connected via a pair of pin members 42 and 42 . The rocking member 43 and the third main body member 45 are rotatably connected in both directions and connected via a pin member 44 . The fourth body member 46 supports the elastic members 48, 48 from below.

A pair of elastic members 48, 48 are coil springs having a predetermined spring constant. A pair of elastic members 48, 48 are supported by the fourth body member 46 and support the base 11 from below. A lower end of the elastic member 48 is fixed to the fourth body member 46 . The restricting member 47 restricts the base 11 from being separated from the fourth body member 46 by a predetermined distance or more. More specifically, the restricting member 47 locks the upper surface of the base 11 that is about to leave the fourth body member 46 by a predetermined distance or more. The upper end of the elastic member 48 is not fixed to the base 11 and supports the base 11 by making contact. That is, each of the pair of elastic members 48 , 48 urges the fourth body member 46 and the base 11 away from each other when in contact with both the fourth body member 46 and the base 11 . The elastic member 48 has a role of reducing vibration transmitted between members in contact with each other. In addition, the elastic member 48 may be fixed to the base 11 and provided to the fourth main body member 46 so as to be separable and contactable.

Although not shown, the first damping mechanism 50 and the second damping mechanism 40 are connected, and the distance between the first damping mechanism 50 and the base 11 in the vertical direction and the distance between the second damping mechanism 40 in the vertical direction and the distance between the base 11 and the base 11 may be provided.

Next, the configuration of the elevation drive unit 6 will be described in detail. As shown in FIG. 4, the lift drive unit 6 includes a base (body) 61, a support 62, four (plural) winding drums 63, a drive motor 63A, and a first idler roller 65A. , a second idler roller (guide roller) 65B, a third idler roller 64, a linear motion mechanism (position adjusting portion) 67, a swinging member 68, and four (plurality) belts B. there is

The base 61 supports the winding drum 63, the first idler roller 65A and the third idler roller 64 via the supporting portion 62. As shown in FIG. The support portion 62 rotatably supports the four winding drums 63 . The four winding drums 63 are arranged in the front-rear direction. The winding drum 63 winds up and lets out each of the four belts B by being driven by a drive motor 63A. The support portion 62 swingably supports the first idler roller 65A and one end portion 68A of the swing member 68 .

Each winding drum 63 is attached to the base 61 via a support portion 62 so as to be rotatable. The drive motor 63A is a drive source for rotating each winding drum 63 and is fixed to the base 61 . The four winding drums 63 are driven by one drive motor 63A by being attached to a common rotating shaft (not shown) or linked by an interlocking mechanism (not shown).

One end of each belt B is connected to the holding unit 7 and the other end of each belt B is connected to each winding drum 63 . In this embodiment, the four belts B are provided so as to suspend the holding unit 7 at three points. More specifically, the holding unit 7 is suspended by four belts B, and two of the four belts B are provided to swing with respect to the holding unit 7. Each of the remaining two of the four belts is connected to a member 43 (see FIG. 3) via a connecting member 41, and each of the remaining two belts has a swinging member 53 provided swingably with respect to the holding unit 7. (see FIG. 3) through a connecting member 51.

The first idler roller 65A and the second idler roller 65B guide movement of the belt B connected to the first cushioning mechanism 50 . The belt B is wound around the first idler roller 65A and the second idler roller 65B. There are two belts B connected to the first buffer mechanism 50, and a first idler roller 65A and a second idler roller 65B are also provided corresponding to each belt B. As shown in FIG. The first idler roller 65A is provided on the support portion 62 . The first idler roller 65A does not move relative to the base 61 . The second idler roller 65B is provided on the swing member 68. As shown in FIG. The second idler roller 65B moves relative to the base 61 . A configuration in which the second idler roller 65B moves relative to the base 61 will be described later. The third idler roller 64 guides movement of the belt B connected to the second cushioning mechanism 40 . The belt B is wound around the third idler roller 64 . There are two belts B connected to the second buffer mechanism 40, and the third idler rollers 64 are also provided corresponding to the respective belts B. As shown in FIG.

The linear motion mechanism 67 mainly has a drive motor 67A, a screw shaft 67B, and a ball nut 67C. The linear motion mechanism 67 is a known mechanism that converts the rotary motion of the drive motor 67A into linear motion. The direct acting mechanism 67 is fixed to the base 61 via a bracket 66 . The ball nut 67C is driven by the drive motor 67A to move along the screw shaft 67B. The other end 68B of the swing member 68 is swingably connected to the ball nut 67C. In this embodiment, the movement of the ball nut 67C along the screw shaft 67B causes the swinging member 68 to swing. to move. In this manner, the linear motion mechanism 67 positions the second idler roller 65B so that the connecting portion (one end of the belt B) of the belt B to the holding unit 7 (first buffer mechanism 50) moves in the vertical direction. move. That is, the linear motion mechanism 67 moves the connection portion of the belt B to the holding unit 7 in the vertical direction by moving the relative position of the second idler roller 65B with respect to the base 61 . The rocking member 68 is changed to a vertically movable member that is cantilevered by the linear motion mechanism 67, and by vertically moving this member, the position of the second idler roller 65B is moved linearly. good too.

When the FOUP 200 is transferred in the ceiling transport vehicle 1, the transport vehicle controller 8 controls the operation of the linear motion mechanism 67 so that the holding unit 7 is maintained in a horizontal state. d) adjusting the inclination of the holding unit 7 with respect to the horizontal plane; Based on the tilt information about the tilt of the holding unit 7, the transport vehicle controller 8 causes the linear motion mechanism 67 to move the second idler roller 65B so that the holding unit 7 is maintained in a horizontal state. Control movement.

A state in which the holding unit 7 is horizontal is, for example, a state in which the upper surface of the holding unit 7 is along a horizontal plane. A state in which the holding unit 7 is horizontal is, for example, a state in which the direction in which the pair of grippers 12 opens and closes is along the horizontal direction. The tilt information may be acquired by, for example, sensors (three-axis sensor and acceleration sensor) provided in the holding unit 7 . For example, the inclination information is stored in a storage unit (not shown) in association with the Z-coordinate of the holding unit 7, etc., by teaching in advance and measuring a correction value for maintaining the horizontal state of the holding unit 7 in advance. You can store it.

For example, as shown in FIG. 5A, even if the lift drive unit 6 is tilted so that the right side of the base 61 is positioned upward (the left side is downward), the linear motion mechanism 67 is operated to By moving the second idler roller 65B upward (closer to the base 61), the holding unit 7 can be maintained in a horizontal state. Further, for example, as shown in FIG. 5B, even when the elevation drive unit 6 is tilted so that the right side of the base 61 is positioned downward (the left side is upward), the linear motion mechanism 67 is operated. If the second idler roller 65B is moved downward (away from the base 61), the holding unit 7 can be maintained in a horizontal state.

Returning to FIG. 1, the ceiling guided vehicle 1 includes a shake detection sensor 10 and a reflector RL. A shake detection sensor 10 is provided in the holding unit 7 . As an example, the shake detection sensor 10 is provided in the center of the upper portion of the holding unit 7 . The shake detection sensor 10 is arranged with its optical axis directed upward, and emits light (laser light or the like) upward. The shake detection sensor 10 is arranged with its light receiving surface facing upward, and receives light from above. The shake detection sensor 10 constitutes a light projector and a light receiver. The shake detection sensor 10 is connected to the carrier controller (first controller) 8 .

The reflector RL is provided in the elevation drive unit. As an example, the reflector RL is provided in the center of the lower portion of the elevation drive unit. Reflector RL is arranged above shake detection sensor 10 . The reflector RL is arranged with its reflective surface facing downward, and reflects downward light from below. The reflector RL is arranged directly above the shake detection sensor 10 when the holding unit 7 is horizontal. The reflector RL is not particularly limited, and various reflectors can be used.

When the FOUP 200 is transferred in the overhead transport vehicle 1, the transport vehicle controller 8 causes the shake detection sensor 10 to emit light, and accordingly the shake detection sensor 10 detects the reflected light reflected by the reflector RL. The vibration of the holding unit 7 is detected based on the light receiving state of . For example, when the amount of light received by the shake detection sensor 10 is equal to or less than the threshold, the transport vehicle controller 8 determines that the light emitted by the shake detection sensor 10 is off the reflector RL due to the shake of the holding unit 7, or It is determined that the reflected light reflected by the reflector RL is off the shake detection sensor 10, and the occurrence of shake is detected.

Here, for example, as shown in FIG. 6, when the lateral unit 4 is driven to move the elevation drive unit 6 and the holding unit 7 in the lateral direction and the FOUP 200 is transferred in this state, During a long transfer in which the FOUP 200 is transferred by extending the belt B downward beyond a certain level, the lateral unit 4 may tilt, and the lift drive unit 6 may tilt accordingly.

In this case, in this embodiment, the operation of the linear motion mechanism 67 (see FIG. 5) is controlled by the carrier controller 8, and the holding unit 7 is held so as to maintain a horizontal state (a horizontal state). The tilt of the unit 7 with respect to the horizontal plane is adjusted. Therefore, even when the elevation drive unit 6 is tilted, the shake detection sensor 10 can emit the light L0 toward the reflecting plate RL directly above it, and the light L0 can be reliably applied to the reflecting plate RL. can. It is possible to prevent the light emitted from the shake detection sensor 10 from deviating from the reflector RL due to the tilt of the elevation drive unit 6 . Further, even when the elevation drive unit 6 is tilted, the reflected light L1 reflected by the reflector RL can be reliably received by the shake detection sensor 10 directly below.

As described above, in the overhead transport vehicle 1 , the shake detection sensor 10 is provided in the holding unit 7 that is maintained in a horizontal state by the horizontal adjustment section 9 . Therefore, tilting of the optical axis of the shake detection sensor 10 due to the inclination of the holding unit 7 can be suppressed, and the optical axis of the shake detection sensor 10 can always be oriented upward. deviating from the reflector plate. Therefore, for example, when the holding unit 7 is not shaken, even if the elevation drive unit 6 is tilted, the light from the shake detection sensor 10 is reliably reflected by the reflector RL and is received by the shake detection sensor 10. , erroneous detection of shaking of the holding unit 7 can be suppressed. That is, it becomes possible to detect the shaking of the holding unit 7 with high accuracy. In addition, it is possible to accurately detect the shaking of the holding unit 7 with a simple configuration.

The overhead transport vehicle 1 includes a second idler roller 65B around which the belt B is wound, a base 61 that supports the take-up drum and the second idler roller 65B, and the relative position of the second idler roller 65B with respect to the base 61. a linear motion mechanism 67 for vertically moving the connecting portion of the belt B to the holding unit 7 by means of the linear motion mechanism 67; a controller 8; In this case, it is possible to maintain the horizontal state of the holding unit 7 with a relatively simple configuration.

In the above description, the base 61, the second idler roller 65B, the linear motion mechanism 67, and the transport vehicle controller 8 constitute a horizontal adjustment section that adjusts the inclination of the holding unit 7 so that the holding unit 7 is kept horizontal.

Although one embodiment has been described above, one aspect of the present invention is not limited to the above embodiment. Various modifications are possible without departing from the gist of one aspect of the invention.

Although the shaking detection sensor 10 is provided in the holding unit 7 in the above embodiment, the light projector and the light receiver may be provided in the holding unit 7 instead. The projector is arranged with its optical axis directed upward. The light receiver is arranged close to the light projector with the light receiving surface facing upward.

In the above-described embodiment, the shake detection sensor 10 is provided in the holding unit 7 and the reflector RL is provided in the elevation drive unit 6. may be provided. That is, the overhead guided vehicle according to one aspect of the present invention includes a holding unit 7, an elevation drive unit 6, a horizontal adjustment section that adjusts the inclination of the holding unit 7 so that the holding unit 7 is maintained in a horizontal state, A light projector provided in the holding unit 7 and arranged with its optical axis facing upward, a light receiver provided in the elevation drive unit 6 and arranged with its light receiving surface facing downward, and a holding unit based on the light receiving state of the light receiver. A transport vehicle controller 8 (first controller) that detects the shaking of 7 may be provided.

Even in this case, since the light projector is provided on the holding unit 7 that is maintained in a horizontal state, it is possible to prevent the optical axis of the light projector from tilting as the holding unit 7 tilts. The optical axis of the light projector can always be oriented upward, and it is possible to prevent the optical axis of the light projector from deviating from the light receiver. Therefore, for example, when the holding unit 7 is not shaken, even if the elevation drive unit 6 is tilted, the light from the light projector is reliably received by the light receiver, thereby suppressing erroneous detection of shaking of the holding unit 7. be able to. That is, it becomes possible to detect the shaking of the holding unit 7 with high accuracy.

In the above-described embodiment and modification, a cam mechanism (position adjusting section) having a similar function may be provided instead of the linear motion mechanism 67 having a function of moving the position of the second idler roller 65B. In the overhead transport vehicle 1 of the above-described embodiment, an example in which one end of the belt B is moved in the vertical direction by moving the position of the second idler roller 65B has been described. By moving the position of one idler roller 65A, one end of the belt B may be moved in the vertical direction.

In the above-described embodiment and modified example, an example in which a ball screw is employed as the linear motion mechanism 67 has been described, but a cylinder, a linear guide, or the like may be employed. Although the holding unit 7 of the above-described embodiment and modifications has been described as being connected to one end of the belt B via the first buffer mechanism 50 and the second buffer mechanism 40, it is directly connected to the holding unit 7. may Alternatively, the four belts B may be directly connected to the holding unit 7 as they are. Also, it may be connected to the holding unit 7 by three belts B. FIG.

Various materials and shapes can be applied to each configuration in the above embodiments and modifications without being limited to the materials and shapes described above. Each configuration in the above embodiment or modification can be arbitrarily applied to each configuration in another embodiment or modification. A part of each configuration in the above embodiment or modification can be omitted as appropriate without departing from the gist of one aspect of the present invention.

DESCRIPTION OF SYMBOLS 1... Ceiling carrier, 6... Lifting drive unit, 7... Holding unit, 8... Carrier controller (first controller, second controller), 9... Horizontal adjustment unit, 10... Shake detection sensor (projector, receiver), 61... Base (main body portion), 65B... Second idler roller (guide roller), 67... Linear motion mechanism (position adjusting portion), 200... FOUP (article), RL... Reflector.

Claims (3)

a holding unit that is provided so as to be able to move up and down and holds an article;
an elevation drive unit that raises and lowers the holding unit by extending and winding a plurality of hanging members connected to the holding unit;
a horizontal adjustment unit that adjusts the inclination of the holding unit so that the holding unit maintains a horizontal state;
a projector provided in the holding unit and arranged with an optical axis directed upward;
a light receiver provided in the holding unit and arranged in proximity to the light projector with a light receiving surface facing upward;
a reflector provided in the elevation drive unit and arranged above the light projector and the light receiver;
and a first controller that detects shaking of the holding unit based on the light receiving state of the light receiver. a holding unit that is provided so as to be able to move up and down and holds an article;
an elevation drive unit that raises and lowers the holding unit by extending and winding a plurality of hanging members connected to the holding unit;
a horizontal adjustment unit that adjusts the inclination of the holding unit so that the holding unit maintains a horizontal state;
a projector provided in the holding unit and arranged with an optical axis directed upward;
a light receiver provided in the elevation drive unit and arranged with a light receiving surface facing downward;
and a first controller that detects shaking of the holding unit based on the light receiving state of the light receiver. The horizontal adjustment unit
a guide roller around which the suspension member is wound;
a main body that supports a winding drum for winding and unwinding the suspension member and the guide roller;
a position adjustment unit that vertically moves a connecting portion of the suspension member to the holding unit by moving the relative position of the guide roller with respect to the main body;
3. The apparatus according to claim 1, further comprising a second controller for controlling movement of said guide roller by said position adjusting section so that said holding unit is maintained in a horizontal state, based on information relating to inclination of said holding unit. The overhead carrier described.

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