JP7234754B2 - overhead carrier - Google Patents

Description

The present invention relates to an overhead transport vehicle.

2. Description of the Related Art In a holding unit having a holding portion that holds an object to be conveyed, there is known an overhead transport vehicle in which the state of the holding portion can be switched between a vibration-proof state and a locked state by a dedicated actuator (see, for example, Patent Document 1). In such an overhead transport vehicle, when traveling while holding an object to be conveyed, the state of the holding portion is switched to a vibration-proof state in which the holding portion is supported by an elastic member, and vibration transmitted to the object to be conveyed is eliminated. On the other hand, when the object to be transported is transferred to the transfer destination, the state of the holding portion is switched to a locked state in which the position of the holding portion is locked. Therefore, the transfer of objects to be conveyed can be stabilized.

JP 2018-39659 A

However, in the overhead guided vehicle described above, since the state of the holding portion is switched by the actuator, if a problem occurs in the control of the actuator, the state of the holding portion cannot be switched at a predetermined timing, resulting in vibration isolation during travel. There is a risk that stabilization of the transfer at the time of validation and transfer will not be realized.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an overhead guided vehicle capable of achieving effective vibration isolation during travel and stable transfer during transfer.

The overhead transport vehicle of the present invention includes a traveling unit that travels along a track, a holding unit that has a holding section that holds an object to be conveyed, an elevation driving unit that has an elevation driving section that raises and lowers the holding unit, and a holding unit. A switching mechanism that brings the holding part into a floating state when the holding unit is positioned at the rising end and puts the holding part into a locked state when the holding unit is positioned below the rising end, and an elastic member that supports the holding part in the floating state. and the switching mechanism brings the holding portion into the floating state or the locked state in conjunction with the movement of the holding unit up and down.

In the overhead transport vehicle of the present invention, when the holding unit is positioned at the raised end, the holding section is brought into a floating state by the switching mechanism, and the holding section in the floating state is supported by the elastic member. As a result, vibration isolation for reducing vibration transmitted to the object to be conveyed when the object to be conveyed is traveling while holding the object to be conveyed can be made effective. Further, when the holding unit is positioned below the rising end, the holding portion is locked by the switching mechanism. As a result, when the object to be transported is transferred to the transfer destination, the transfer of the object to be transported can be stabilized. Here, in the overhead guided vehicle of the present invention, the switching mechanism for switching the holding section to the floating state or the locked state switches the state of the holding section in conjunction with the movement of the holding unit to move up and down. That is, in the switching mechanism, it is not necessary to employ a dedicated actuator for switching the state of the holding portion. As described above, according to the overhead guided vehicle of the present invention, it is possible to reliably realize effective vibration isolation during traveling and stable transfer during transfer.

In the overhead transport vehicle of the present invention, the elevation drive section includes a belt from which the holding unit is suspended and a drum that winds the belt, the switching mechanism has a support arm provided in the elevation drive unit, The support arm supports the elevation driving section when the holding unit is positioned below the rising end, thereby locking the elevation driving section and the holding unit, and the winding diameter of the drum increases when the holding unit rises. The lifting drive and the holding unit may be floated by being operated by the increasing belt, and the elastic member may be provided on the lifting drive unit to support the lifting drive in the floating state. In this way, by configuring the support arm so as to be operated by the belt whose winding diameter increases on the drum when the holding unit is lifted, the reduction ratio is increased and the load on the drum drive motor is reduced. can be done. Further, by providing the lifting drive unit with an elastic member so as to support the lifting drive unit and the holding unit that are in a floating state, vibration isolation can be effectively achieved even for a heavy object to be conveyed. Even if the weight of the object changes, the same level of anti-vibration effect can be expected.

In the overhead transport vehicle of the present invention, a plurality of elastic members may be provided in the elevation drive unit, and may be arranged evenly with respect to the center of gravity of the elevation drive section and the holding unit in the elevation drive section. As a result, even if it is necessary to provide a guide for vertically guiding the lift drive unit that is in a floating state and is supported by a plurality of elastic members, the design of the guide (for example, strength against bending, installation position, number of units, etc.) etc.) can be improved.

In the overhead guided vehicle of the present invention, the switching mechanism has a push rod provided in the elevation drive unit and a support plate provided in the holding unit, and the support plate is arranged such that the holding unit is located below the rising end. The holding portion is locked by supporting the holding portion when the holding portion is positioned at the position of the holding portion, and the holding portion is brought into the floating state by being pushed by the push rod when the holding unit is raised, and the elastic member is provided in the holding unit. and may support the holding portion in a floating state. As a result, it is possible to prevent the configuration of the elevation drive unit from becoming complicated.

According to the present invention, it is possible to provide an overhead transport vehicle that can reliably achieve effective vibration isolation during travel and stable transfer during transfer.

It is a side view of the overhead transport vehicle of the first embodiment. FIG. 4 is a configuration diagram of the lifting drive unit and the holding unit when the holding section is in the locked state in the ceiling transport vehicle of the first embodiment; FIG. 4 is a configuration diagram of the lifting drive unit and the holding unit when the holding section is in a floating state in the ceiling guided vehicle of the first embodiment; FIG. 11 is a configuration diagram of the lifting drive unit and the holding unit when the holding section is in the locked state in the ceiling guided vehicle of the second embodiment; FIG. 12 is a configuration diagram of the lifting drive unit and the holding unit when the holding section is in a floating state in the ceiling guided vehicle of the second embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.
[First embodiment]

As shown in FIG. 1, the overhead carrier 1 of the first embodiment travels along a track 100 laid near the ceiling of a clean room where semiconductor devices are manufactured. The overhead transport vehicle 1 of the first embodiment is provided in a processing apparatus that transports a FOUP (Front Opening Unified Pod) (object to be transported) 200 containing a plurality of semiconductor wafers and performs various processes on the semiconductor wafers. The FOUP 200 is transferred to the load port 300 .

The ceiling transport vehicle 1 includes a frame unit 2, a traveling unit 3, a lateral unit 4, a sheeter unit 5, an elevation driving unit 6, a holding unit 7, and a controller 8. The frame unit 2 has a center frame 21 , a front frame 22 and a rear frame 23 . The front frame 22 extends downward from the front end of the center frame 21 (the front side in the running direction of the overhead transport vehicle 1). The rear frame 23 extends downward from the rear end of the center frame 21 (the rear side in the running direction of the overhead transport vehicle 1).

The traveling unit 3 is arranged above the center frame 21 . The traveling unit 3 travels along the track 100 by being supplied with power without contact from, for example, a high-frequency current line laid along the track 100 . The lateral unit 4 is arranged below the center frame 21 . 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 driving unit 6 has an elevation driving section 60 for raising and lowering the holding unit 7 . The holding unit 7 is arranged below the elevation drive unit 6 . The holding unit 7 has a holding portion 70 that holds the flange portion 201 of the FOUP 200 . The controller 8 is arranged on the center frame 21 . The controller 8 is an electronic control unit including a CPU, ROM, RAM, and the like. The controller 8 controls each part of the ceiling transport vehicle 1 .

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 above the load port 300 . Subsequently, the lifting drive section 60 lowers the holding unit 7 , and the holding section 70 holds the flange section 201 of the FOUP 200 placed on the load port 300 . Subsequently, the elevation driving section 60 raises the holding unit 7 to the upper end to arrange the FOUP 200 between the front frame 22 and the rear frame 23 . Subsequently, the ceiling transport vehicle 1 holding the FOUP 200 starts traveling.

On the other hand, when transferring the FOUP 200 from the overhead transport vehicle 1 to the load port 300 , the overhead transport vehicle 1 holding the FOUP 200 stops above the load port 300 . Subsequently, the lifting drive section 60 lowers the holding unit 7 to place the FOUP 200 on the load port 300 , and the holding section 70 releases the holding of the flange section 201 of the FOUP 200 . Subsequently, the elevation driving section 60 raises the holding unit 7 to the upper end. Subsequently, the overhead transport vehicle 1 not holding the FOUP 200 starts running.

Next, the configurations of the elevation drive unit 6 and the holding unit 7 will be described in detail. As shown in FIGS. 2 and 3 , the elevation drive section 60 of the elevation drive unit 6 has a base 61 , multiple belts 62 , multiple drums 63 , and a drive motor 64 . Each drum 63 is supported by the base 61 so as to be rotatable. A drive motor 64 is a drive source for rotating each drum 63 and is fixed to the base 61 . One end of each belt 62 is connected to each drum 63 and the other end of each belt 62 is connected to the holding unit 7 . Each belt 62 is guided to a predetermined position by a plurality of guide pulleys 65 provided in the elevation drive section 60 . The lifting drive unit 60 configured as described above raises the holding unit 7 by causing the drum 63 to wind up a plurality of belts 62 from which the holding units 7 are suspended, thereby moving the plurality of belts from which the holding units 7 are suspended. The holding unit 7 is lowered by the drum 63 feeding out the belt 62 .

In the elevation drive unit 6 , the base 61 is arranged inside the housing 66 . The housing 66 has a bottom wall 66a, a top wall 66b, and side walls 66c. The base 61 is movable only in the vertical direction by a linear motion mechanism 67 provided inside the housing 66 . The linear motion mechanism 67 is, for example, an LF guide mechanism, a ball spline mechanism, or the like. A plurality of elastic members 11 are arranged between the bottom wall 66 a and the base 61 . Each elastic member 11 is, for example, a gel material, a rubber material, a compression spring, or the like. A plurality of stoppers 68 for stopping upward movement of the base 61 are provided on the top wall 66b.

The holding portion 70 of the holding unit 7 has a base 71 and a pair of gripping portions 72 . The pair of grips 72 are supported by the base 71 so that they can be opened and closed in the horizontal direction. The pair of grips 72 are opened and closed by a drive motor (not shown) and a link mechanism (not shown). In the holding unit 7 , the base 71 constitutes the bottom wall of the housing 73 and is fixed in position relative to the housing 73 . The base 71 and the other end of each belt 62 are connected.

A switching mechanism 9 is provided in the elevation drive unit 6 . The switching mechanism 9 brings the holding portion 70 into a floating state (the state shown in FIG. 3) when the holding unit 7 is positioned at the rising end, and the holding portion 70 when the holding unit 7 is positioned below the rising end. to the locked state (the state shown in FIG. 2). The floating state is a state in which the holding portion 70 is directly or indirectly supported by the plurality of elastic members 11 . The locked state is a state in which the holding portion 70 is directly or indirectly supported by some supporting portion having a larger supporting force in the vertical direction than the plurality of elastic members 11 . The switching mechanism 9 brings the holding portion 70 into a floating state or a locked state in conjunction with the movement of the holding unit 7 up and down.

In the first embodiment, the switching mechanism 9 has a support arm 91 and a biasing member 92 . An intermediate portion of the support arm 91 is supported by a shaft 61a provided on the base 61, and one end portion 91a and the other end portion 91b of the support arm 91 are allowed to swing in a vertical plane. One end portion 91 a is configured as, for example, a roller and positioned near one drum 63 . The other end portion 91b is configured as a roller, for example, and positioned between the bottom wall 66a and the base 61. As shown in FIG. The biasing member 92 is, for example, a torsion coil spring attached to the shaft 61a, and biases the support arm 91 so that the other end 91b moves toward the bottom wall 66a.

As shown in FIG. 2, when the holding unit 7 is positioned below the rising end, regardless of whether the holding unit 7 is raised or lowered, the force is applied by the biasing member 92. The other end 91 b of the support arm 91 is pressed against the bottom wall 66 a so that the support arm 91 supports the lifting drive section 60 together with the holding unit 7 . At this time, the base 61 comes into contact with the plurality of stoppers 68, thereby fixing the position of the elevation driving section 60. As shown in FIG. In this manner, the support arm 91 supports the elevation drive section 60 to lock the elevation drive section 60 and the holding unit 7 .

As shown in FIG. 3, when the holding unit 7 is positioned at the raised end, the other end 91b of the support arm 91 whose one end 91a is pushed by the belt 62 whose winding diameter is increased on the drum 63 is pushed to the bottom wall. By moving away from 66 a , the support arm 91 brings the lifting drive section 60 into a floating state together with the holding unit 7 . At this time, the plurality of elastic members 11 provided in the elevation drive unit 6 support the elevation drive section 60 in the floating state. In this manner, the support arm 91 is operated by the belt 62 whose winding diameter increases on the drum 63 when the holding unit 7 is lifted, thereby bringing the lifting drive section 60 and the holding unit 7 into a floating state. The holding portion 70 in the floating state is supported by the plurality of elastic members 11 via the elevation driving portion 60 .

In the first embodiment, as shown in FIG. 2, the lifting drive section 60 and the holding unit 7 are locked by the switching mechanism 9 supporting the lifting drive section 60 and the holding unit 7 . That is, when the other end portion 91b of the support arm 91 urged by the urging member 92 is pressed against the bottom wall 66a, the switching mechanism 9 supports the up/down driving section 60 and the holding unit 7 (the switching mechanism in the vertical direction). 9) is greater than the force (supporting force of the plurality of elastic members 11 in the vertical direction) with which the plurality of elastic members 11 support the elevation driving section 60 and the holding unit 7 .

In the first embodiment, the plurality of elastic members 11 are evenly arranged with respect to the position of the center of gravity of the lifting drive section 60 and the holding unit 7 in the lifting drive section 60 . The position of the center of gravity of the lifting drive section 60 and the holding unit 7 in the lifting drive section 60 is the position of the center of weight (center of mass) of the total weight of the lifting drive section 60 and the holding unit 7, and is the position in the horizontal plane. The plurality of elastic members 11 are evenly arranged with respect to the position of the center of gravity (that is, so that the pressure generated on each elastic member 11 by the total weight of the lifting drive section 60 and the holding unit 7 is uniform).

As described above, in the ceiling guided vehicle 1 of the first embodiment, when the holding unit 7 is positioned at the rising end, the holding section 70 is indirectly brought into the floating state by the switching mechanism 9, and the holding portion 70 in the floating state is held. A portion 70 is indirectly supported by the plurality of elastic members 11 . As a result, when the FOUP 200 is held and traveled, vibration isolation for reducing vibration transmitted to the FOUP 200 is made effective. Further, when the holding unit 7 is positioned below the rising end, the holding portion 70 is indirectly locked by the switching mechanism 9 . As a result, when the FOUP 200 is transferred to the load port 300, the transfer of the FOUP 200 is stabilized. Here, in the overhead guided vehicle 1 of the first embodiment, the switching mechanism 9 that switches the holding section 70 to the floating state or the locked state switches the state of the holding section 70 in conjunction with the movement of the holding unit 7 to move up and down. In other words, the switching mechanism 9 does not need to employ a dedicated actuator to switch the state of the holding portion 70 . As described above, according to the overhead guided vehicle 1 of the first embodiment, it is possible to reliably realize effective vibration isolation during traveling and stable transfer during transfer.

In addition, in the ceiling guided vehicle 1 of the first embodiment, the support arm 91 of the switching mechanism 9 supports the elevation driving section 60 when the holding unit 7 is positioned below the rising end, so that the elevation driving section 60 and the holding unit 7 are locked, and when the holding unit 7 is lifted, the belt 62 whose winding diameter increases on the drum 63 is operated, so that the elevation driving section 60 and the holding unit 7 are brought into the floating state. When the support arm 91 of the switching mechanism 9 puts the lifting drive section 60 and the holding unit 7 into the floating state, the plurality of elastic members 11 support the lifting drive section 60 in the floating state. In this way, by configuring the support arm 91 so as to be operated by the belt 62 whose winding diameter increases on the drum 63 when the holding unit 7 is raised, the speed reduction ratio is increased and load can be reduced. In addition, by providing a plurality of elastic members 11 in the lifting drive unit 6 so as to support the lifting drive unit 60 and the holding unit 7 in the floating state, it is possible to achieve effective vibration isolation even for the heavy FOUP 200 . Therefore, even if the weight of the FOUP 200 changes, the same degree of vibration isolation effect can be expected.

Further, in the ceiling guided vehicle 1 of the first embodiment, the plurality of elastic members 11 are evenly arranged with respect to the center of gravity of the lifting drive section 60 and the holding unit 7 in the lifting drive section 60 . As a result, the linear motion mechanism 67, which is a guide for vertically guiding the lifting drive unit 60 which is in a floating state and is supported by the plurality of elastic members 11, is designed (for example, the strength against bending, the installation position, the number, etc.). setting) can be improved.
[Second embodiment]

The ceiling guided vehicle 1 of the second embodiment travels along the track 100 , carries the FOUP 200 , and transfers the FOUP 200 to the load port 300 in the same manner as the ceiling guided vehicle 1 of the first embodiment. The ceiling guided vehicle 1 of the second embodiment differs from the ceiling guided vehicle 1 of the first embodiment in the configuration of the elevation drive unit 6 and the holding unit 7 . Hereinafter, the configuration of the elevation drive unit 6 and the holding unit 7 in the ceiling guided vehicle 1 of the second embodiment will be described in detail.

As shown in FIGS. 4 and 5 , the elevation drive section 60 of the elevation drive unit 6 has a base 61 , multiple belts 62 , multiple drums 63 , and a drive motor 64 . The base 61 is arranged in a housing 66 and fixed in position relative to the housing 66 . The holding portion 70 of the holding unit 7 has a base 71 and a pair of gripping portions 72 . The pair of grips 72 are opened and closed by a drive motor (not shown) and a link mechanism (not shown). The other end of each belt 62 is connected to the bottom wall 73 a of the housing 73 . A plurality of elastic members 11 are arranged between the bottom wall 73 a and the base 71 . Each elastic member 11 is, for example, a gel material, a rubber material, a compression spring, or the like. Note that the base 71 may be movable only in the vertical direction by a linear motion mechanism (for example, an LF guide mechanism, a ball spline mechanism, etc.) provided inside the housing 73 .

A switching mechanism 9 is provided in the elevation drive unit 6 and the holding unit 7 . The switching mechanism 9 brings the holding portion 70 into a floating state (the state shown in FIG. 5) when the holding unit 7 is positioned at the rising end, and the holding portion 70 when the holding unit 7 is positioned below the rising end. to the locked state (the state shown in FIG. 4). The switching mechanism 9 brings the holding portion 70 into a floating state or a locked state in conjunction with the movement of the holding unit 7 up and down.

In the second embodiment, the switching mechanism 9 has a push rod 93 , a support plate 94 and an urging member 95 . The push rod 93 is provided in the elevation drive unit 6 and extends downward from the housing 66 . A support plate 94 is provided on the holding unit 7 . More specifically, the support plate 94 is arranged between the bottom wall 73 a and the base 71 and can come into contact with the peripheral portion of the opening 71 a formed in the base 71 . The opening 71a faces the push rod 93 in the vertical direction. The biasing member 95 is, for example, a compression spring disposed between the bottom wall 73a and the support plate 94, and biases the support plate 94 so that the support plate 94 moves toward the peripheral portion of the opening 71a. .

As shown in FIG. 4, when the holding unit 7 is positioned below the rising end, regardless of whether the holding unit 7 is raised or lowered, the force is applied by the biasing member 95. The support plate 94 supports the holding portion 70 by being pressed against the peripheral portion of the opening 71 a in the base 71 . In this manner, the support plate 94 supports the holding portion 70 to lock the holding portion 70 .

As shown in FIG. 5, when the holding unit 7 is positioned at the raised end, the support plate 94 pushed downward by the push rod 93 is separated from the surrounding portion of the opening 71a in the base 71, so that the support plate 94 floats the retainer 70 . At this time, the plurality of elastic members 11 provided in the holding unit 7 support the holding portion 70 in the floating state. In this way, the support plate 94 is pushed by the push rod 93 when the holding unit 7 rises, thereby bringing the holding section 70 into the floating state.

In the second embodiment, as shown in FIG. 4, the holding portion 70 is locked by the switching mechanism 9 supporting the holding portion 70 . In other words, the support plate 94 urged by the urging member 95 is pressed against the peripheral portion of the opening 71a in the base 71, so that the switching mechanism 9 supports the holding portion 70 (supporting force of the switching mechanism 9 in the vertical direction). is greater than the force with which the plurality of elastic members 11 support the holding portion 70 (the supporting force of the plurality of elastic members 11 in the vertical direction).

As described above, in the ceiling guided vehicle 1 of the second embodiment, when the holding unit 7 is positioned at the rising end, the holding section 70 is directly brought into the floating state by the switching mechanism 9, and the holding portion 70 in the floating state is held. A portion 70 is directly supported by the plurality of elastic members 11 . As a result, when the FOUP 200 is held and traveled, vibration isolation for reducing vibration transmitted to the FOUP 200 is made effective. Further, when the holding unit 7 is positioned below the rising end, the holding portion 70 is directly locked by the switching mechanism 9 . As a result, when the FOUP 200 is transferred to the load port 300, the transfer of the FOUP 200 is stabilized. Here, in the ceiling guided vehicle 1 of the second embodiment, the switching mechanism 9 that switches the holding section 70 to the floating state or the locked state switches the state of the holding section 70 in conjunction with the movement of the holding unit 7 up and down. In other words, the switching mechanism 9 does not need to employ a dedicated actuator to switch the state of the holding portion 70 . As described above, according to the overhead transport vehicle 1 of the second embodiment, it is possible to reliably realize effective vibration isolation during traveling and stable transfer during transfer.

In addition, in the ceiling guided vehicle 1 of the second embodiment, the support plate 94 of the switching mechanism 9 supports the holding portion 70 when the holding unit 7 is positioned below the rising end. By being pushed by the push rod 93 of the switching mechanism 9 when the holding unit 7 is lifted in the locked state, the holding portion 70 is brought into the floating state. When the support plate 94 of the switching mechanism 9 brings the holding portion 70 into the floating state, the plurality of elastic members 11 support the holding portion 70 in the floating state. As a result, complication of the configuration of the elevation drive unit 6 can be prevented.
[Modification]

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, the object to be transferred according to the present invention is not limited to the FOUP 200, and may be other articles such as a reticle pod containing a plurality of glass substrates. Further, the track on which the overhead transport vehicle of the present invention travels is not limited to the track 100 laid near the ceiling of the clean room where semiconductor devices are manufactured, and may be a track laid near the ceiling of other facilities. good. Moreover, the elastic member of the present invention is not limited to the plurality of elastic members 11, and may be at least one elastic member.

DESCRIPTION OF SYMBOLS 1... Ceiling carrier, 3... Traveling unit, 6... Lifting drive unit, 7... Holding unit, 9... Switching mechanism, 11... Elastic member, 60... Lifting drive part, 62... Belt, 63... Drum, 70... Holding part , 91... Support arm, 93... Push rod, 94... Support plate, 100... Track, 200... FOUP (object to be conveyed).

Claims (4)

a traveling unit that travels along a track;
a holding unit having a holding portion that holds an object to be conveyed;
a lifting drive unit having a lifting drive unit for lifting and lowering the holding unit;
a switching mechanism that brings the holding portion into a floating state when the holding unit is positioned at the rising end and puts the holding portion into a locked state when the holding unit is positioned below the rising end;
an elastic member that supports the holding portion in the floating state;
The overhead transport vehicle, wherein the switching mechanism puts the holding section in the floating state or the locked state in conjunction with the lifting operation of the holding unit. The lifting drive unit includes a belt from which the holding unit is suspended, and a drum that winds the belt,
The switching mechanism has a support arm provided in the elevation drive unit,
The support arm supports the elevation driving section when the holding unit is positioned below the rising end, thereby placing the elevation driving section and the holding unit in the locked state and raising the holding unit. When the belt is operated by the belt whose winding diameter increases in the drum, the lifting drive unit and the holding unit are placed in the floating state,
2. The overhead transport vehicle according to claim 1, wherein said elastic member is provided in said elevation drive unit and supports said elevation drive section in said floating state. 3. The overhead transport according to claim 2, wherein a plurality of said elastic members are provided in said lifting drive unit, and are arranged evenly with respect to the center of gravity of said lifting drive part and said holding unit in said lifting drive part. car. The switching mechanism has a push rod provided in the elevation drive unit and a support plate provided in the holding unit,
The support plate supports the holding portion when the holding unit is located below the rising end, thereby placing the holding portion in the locked state and pushing the push rod when the holding unit is raised. by pushing the holding part to the floating state,
2. The overhead transport vehicle according to claim 1, wherein said elastic member is provided in said holding unit and supports said holding section in said floating state.

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