Ceiling transport vehicle

Abstract

To prevent items from shaking or tilting.SOLUTION: A ceiling transport vehicle (1) includes: a lifting body (20) having a main body (21), a gripping portion (22) for gripping an item P, an elastic portion (23) for elastically supporting the gripping portion (22), and a locking mechanism (24) for locking the elastic portion (23) so as not to permit movement; and a switching portion (30) that switches the lock mechanism (24) between a locked state and an unlocked state. The switching portion (30) switches the locking mechanism (24) from the locked state to the unlocked state after a sway suppression unit (40) has completed clamping the item P.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an overhead transport vehicle for transporting articles. [Background technology]

[0002] There is known an overhead transport vehicle that uses a lifting unit to lift and hold an object and transport it. When the object is transported or transferred by the overhead transport vehicle, the object may sway, and various measures have been taken to reduce the effects of this swaying. For example, Patent Document 1 describes an overhead transport vehicle that has a locking mechanism that locks the relative positional relationship between a lifting member mounting unit and a base unit on which a gripping unit is provided, and that locks the locking mechanism when the vehicle is lifted or lowered and unlocks the locking mechanism when the vehicle is traveling.

[0003] Patent document 2 also describes an article transport vehicle in which the contact portion of the vibration suppression mechanism, which contacts the side of the article to suppress vibration, is elastically supported in the vertical direction, thereby suppressing lateral vibration while mitigating the transmission of vertical vibration. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 0429203 [Patent Document 2] Japanese Patent Publication No. 2022-125650 Summary of the Invention [Problem to be solved by the invention]

[0005] however, In the conventional technology, the overhead transport vehicle starts moving as soon as an article is placed inside, and a vibration suppression mechanism that contacts the side of the article to suppress vibration and a fall prevention mechanism that protrudes from the bottom of the article to prevent it from falling are activated. Therefore, there are problems in that the article will shake and tilt immediately after starting to move, or the article will get caught in the fall prevention mechanism in a tilted state, causing it to move while tilted.

[0006] One aspect of the present invention has been made in view of the above-mentioned problems, and its object is to realize an overhead transport vehicle that suppresses shaking and tilting of articles. [Means for solving the problem]

[0007] In order to solve the above-mentioned problem, one embodiment of the present invention provides a ceiling transport vehicle that transports items, and includes a running section that runs along a track, a lifting body that is suspended from the running section so that it can be raised and lowered and that grips the item, and a sway suppression section that clamps the item to suppress swaying of the item, and the lifting body has a main body section, a gripping section that grips the item, an elastic section that elastically supports the gripping section relative to the main body section, and a locking mechanism that locks the gripping section to a locked state that does not allow the elastic section to move relative to the main body section, and further includes a switching section that switches the locking mechanism between a locked state and an unlocked state, and the switching section switches the locking mechanism from the locked state to the unlocked state after the item has been lifted and the gripping of the item by the sway suppression section has been completed. [Effects of the Invention]

[0008] According to one aspect of the present invention, the locking mechanism is unlocked after the sway suppression unit has completed clamping the item, so that the locking mechanism is unlocked before the sway suppression unit has completed clamping the item, thereby preventing the item from swaying or tilting. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing an overhead transport vehicle according to an embodiment of the present invention; [Figure 2] FIG. [Figure 3] 10A and 10B are diagrams for explaining the operation of the lifting body. [Figure 4] 10A and 10B are diagrams illustrating a state in which the vibration suppression unit and the fall prevention unit are operating. [Figure 5]10A and 10B are diagrams illustrating the timing of switching the lock mechanism when an article is scooped and transported. [Figure 6] 10A and 10B are diagrams illustrating the timing of switching the lock mechanism when an article is scooped and transported. [Figure 7] 10A and 10B are diagrams illustrating timings for switching the lock mechanism when transferring an article being transported. [Figure 8] 10A and 10B are diagrams illustrating timings for switching the lock mechanism when transferring an article being transported. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described in detail below. An overhead transport vehicle 1 according to this embodiment transports an article P such as a FOUP (Front Opening Unified Pod) by traveling along a track provided at a position higher than the floor surface, such as a ceiling. The FOUP contains, for example, multiple semiconductor wafers.

[0011] Fig. 1 is a front view of an overhead transport vehicle 1. As shown in Fig. 1, the overhead transport vehicle 1 includes a running section 10 that runs along a track (not shown), a lifting body 20 that is suspended from the running section 10 so as to be able to rise and fall and that grips an article P, and a switching section 30 that switches a locking mechanism 24. Furthermore, the overhead transport vehicle 1 includes a vibration suppression section 40 that suppresses vibration when transporting the article P, and a fall prevention section 50 that prevents the article P from falling.

[0012] In this embodiment, the direction in which the overhead transport vehicle 1 travels is the X direction, the direction perpendicular to the traveling direction on a horizontal plane is the Y direction, and the direction in which the lifting body 20 moves up and down is the Z direction. In the overhead transport vehicle 1 shown in Fig. 1, the X direction is from left to right in the drawing, the Y direction is from front to back, and the Z direction is from bottom to top.

[0013] The lifting body 20 has a main body portion 21, a gripping portion 22 that grips the item P, an elastic portion 23 that elastically supports the gripping portion 22 relative to the main body portion 21, and a locking mechanism 24 that locks the gripping portion 22 so that the elastic portion 23 does not allow the gripping portion 22 to move relative to the main body portion 21.

[0014] The gripping portion 22 grips the article P by pinching a part of the article P between a pair of members.

[0015] The elastic portions 23 may be provided on each of the pair of members of the gripping portion 22, and may elastically support the gripping portion 22 in the up-down direction relative to the main body portion 21. By elastically supporting the gripping portion 22, it is possible to mitigate swinging of the gripping portion 22 in the up-down direction (Z direction). In other words, it is possible to mitigate swinging of the article P gripped by the gripping portion 22 in the up-down direction.

[0016] Furthermore, the elastic portions 23 are provided for each of the pair of members of the gripping portion 22 and are arranged side by side in the horizontal direction. That is, the elastic portions 23 that provide elastic support in the vertical direction are arranged side by side in the horizontal direction. This prevents the article P being gripped by the gripping portion 22 from being gripped at an angle. Here, the horizontal direction is the direction parallel to the horizontal plane (XY plane).

[0017] An example of the locking mechanism 24 is shown in Figure 2. Figure 2 is a front view of the lifting body 20 of the ceiling transport vehicle 1. 201 in Figure 2 shows a locked state in which the elastic part 23 does not allow the gripping part 22 to move relative to the main body part 21, and 202 in Figure 2 shows an unlocked state in which the elastic part 23 allows the gripping part 22 to move relative to the main body part 21.

[0018] The locking mechanism 24 is in a locked state by fixing the relative position of the gripping portion 22 with respect to the main body portion 21 so that the elastic portion 23 cannot expand or contract. On the other hand, the locking mechanism 24 is in an unlocked state by not fixing the relative position of the gripping portion 22 with respect to the main body portion 21 so that the elastic portion 23 can expand and contract freely.

[0019] FIG. 3 shows the operation of the lifting body 20. As shown in FIG. 3, the lifting body 20 descends in the Z direction and grips the item P by opening and closing the gripping section 22 in the X direction. More specifically, the lifting body 20 descends in the Z direction and opens the gripping section 22 near the item P. It then continues to descend in the Z direction and closes the gripping section 22 at a position where the gripping section 22 can grip a portion of the item P. This allows the gripping section 22 to grip the item P, and the lifting body 20 rises while gripping the item P. This allows the ceiling transport vehicle 1 to transfer and transport the item P using the lifting body 20.

[0020] FIG. 4 shows the state in which the vibration suppression unit 40 and the fall prevention unit 50 are operating. As shown in FIG. 4, when the vibration suppression unit 40 operates, it protrudes from the side wall of the traveling unit 10 so as to clamp the item P. In other words, the vibration suppression unit 40 protrudes from the side wall of the traveling unit 10 in the X direction so as to clamp the item P. When the overhead transport vehicle 1 is traveling, acceleration and deceleration can cause the item P to sway back and forth in the traveling direction. By operating the vibration suppression unit 40, it can clamp the item P from the front and back in the traveling direction, so that the item P can be prevented from swaying back and forth in the traveling direction while the overhead transport vehicle 1 is transporting the item P.

[0021] Furthermore, when the fall prevention unit 50 operates, the protrusion protrudes from the lower part of the side wall of the traveling unit 10 toward the bottom surface of the article P. The protrusion of the fall prevention unit 50 protrudes so as to overlap with at least a part of the bottom surface of the article P when viewed from the Z direction, so that the article P can be prevented from falling from the ceiling transport vehicle 1 even if the gripping unit 22 loses grip on the article P.

[0022] The vibration suppression unit 40 and the fall prevention unit 50 may be connected to each other by a link mechanism (not shown) and configured to operate simultaneously using a common drive unit (not shown), thereby allowing the vibration suppression unit 40 and the fall prevention unit 50 to operate simultaneously.

[0023] In other words, the fall prevention unit 50 prevents the article P from falling by projecting its protrusion below the bottom surface of the article P. The fall prevention unit 50 operates simultaneously with the sway suppression unit 40. This allows the locking mechanism 24 to be set to the unlocked state after the projection of the fall prevention unit 50, in addition to the sway suppression unit 40, is completed.

[0024] The switching unit 30 switches the locking mechanism 24 between a locked state and an unlocked state. After the item P is lifted and the sway suppression unit 40 has completed clamping the item P, the switching unit 30 switches the locking mechanism 24 from a locked state to an unlocked state. Lifting the item P means raising the lifting body 20 holding the item P to its upper limit position. The upper limit position is the position of the lifting body 20 when the ceiling transport vehicle 1 is traveling. In other words, it means raising the lifting body 20 holding the item P to the position at which the ceiling transport vehicle 1 is traveling.

[0025] The timing of switching of the lock mechanism 24 by the switching unit 30 will be described in detail later.

[0026] [Switching Timing by Switching Unit 30] Next, the timing of switching the lock mechanism 24 by the switching unit 30 will be described with reference to FIGS.

[0027] The switching unit 30 may perform switching of the lock mechanism 24 mechanically or by software. When the switching unit 30 is performed by software, the switching unit 30 may include an electronic control unit including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc.

[0028] First, a case where an empty ceiling transport vehicle 1 scoops up and transports an article P will be described with reference to Figures 5 and 6. Figures 5 and 6 are diagrams showing the switching timing of the lock mechanism 24 when scooping up and transporting an article P.

[0029] As shown in 501 of Fig. 5, when the overhead transport vehicle 1 is not transporting an article P, i.e., when the vehicle is empty, the locking mechanism 24 is in an unlocked state. When the overhead transport vehicle 1 travels in this state to the location of the article P to be transferred, as shown in 502 of Fig. 5, the overhead transport vehicle 1 lowers the lifting body 20 and opens and closes the gripping part 22 to grip the article P. The locking mechanism 24 is in an unlocked state until the article P is gripped.

[0030] Then, as shown at 503 in Fig. 5, when the gripping unit 22 grips the article P, the switching unit 30 locks the locking mechanism 24. As shown at 504 in Fig. 5, when the lifting body 20 is raised to its upper limit position while the locking mechanism 24 remains locked, the sway suppression unit 40 and the fall prevention unit 50 are operated while the locking mechanism 24 remains locked, as shown at 505 in Fig. 6. At this point, the ceiling transport vehicle 1 also starts traveling and begins transporting the article P. Then, as shown at 506 in Fig. 6, after the operation of the sway suppression unit 40 and the fall prevention unit 50 is completed, the switching unit 30 unlocks the locking mechanism 24.

[0031] In other words, the traveling section 10 starts traveling of the ceiling transport vehicle 1 when the locking mechanism 24 is in the locked state, and the vibration suppressing section 40 starts clamping the article P simultaneously with or after the start of traveling. Therefore, the traveling section 10 is still in the locked state at the start of traveling, and the vibration of the article P due to traveling can be suppressed.

[0032] As described above, the switching unit 30 switches the locking mechanism 24 from the locked state to the unlocked state after the article P has been lifted and the sway suppression unit 40 has completed clamping the article P. As a result, the locking mechanism 24 becomes unlocked after the sway suppression unit 40 has completed clamping the article P, and therefore, the locking mechanism 24 becomes unlocked before the sway suppression unit 40 has completed clamping the article P, thereby preventing the article P from swaying or tilting.

[0033] Next, a case where the article P being transported is placed at a transfer destination will be described with reference to Fig. 7. Fig. 7 is a diagram showing the switching timing of the lock mechanism 24 when the article P being transported is placed at a transfer destination.

[0034] As shown in 701 in Fig. 7, the locking mechanism 24 is in an unlocked state while the article P is being transported. In this state, when the article P approaches the transfer destination, that is, when the article P reaches a point a predetermined distance ahead of the predetermined stop position that will be the transfer destination, the switching unit 30 switches the locking mechanism 24 from the unlocked state to the locked state, as shown in 702 in Fig. 7.

[0035] In other words, when the ceiling transport vehicle 1 stops at a predetermined stopping position that is the transfer destination, the switching unit 30 switches the locking mechanism 24 from the unlocked state to the locked state at a point a predetermined distance before the stopping position. As a result, when the ceiling transport vehicle 1 stops, the locking mechanism 24 is switched from the unlocked state to the locked state at a point a predetermined distance before the stopping position, so when the ceiling transport vehicle 1 arrives at the stopping position, the locking mechanism 24 is in the locked state, and the next operation can be started promptly.

[0036] The switching of the locking mechanism 24 from the unlocked state to the locked state by the switching unit 30 and the start of the release of the clamping of the article P by the sway suppression unit 40 may occur simultaneously, or the switching of the locking mechanism 24 from the unlocked state to the locked state by the switching unit 30 may be followed by the start of the release of the clamping of the article P by the sway suppression unit 40. In either configuration, the clamping of the article P by the sway suppression unit 40 is released in the locked state, thereby reducing the situations in which the article sways.

[0037] Thereafter, as shown in 703 of Fig. 7, with the locking mechanism 24 in the locked state, the sway suppression unit 40 and the fall prevention unit 50 are released. Then, as shown in 704 of Fig. 7, the lifting body 20 is lowered to place the article P at the destination. Once the bottom surface of the article P is placed at the destination, as shown in 705 of Fig. 8, the switching unit 30 switches the locking mechanism 24 from the locked state to the unlocked state.

[0038] That is, when the lifting body 20 is gripping an item P and descending, the switching unit 30 unlocks the locking mechanism 24 when the item P reaches the destination. As a result, when the lifting body 20 is gripping an item P and descending, the locking mechanism 24 remains locked until the item reaches the destination, allowing the item P to be accurately placed in the placement position at the destination. If the locking mechanism 24 were to be unlocked while the lifting body 20 was gripping an item P and descending, the weight of the item P would cause the gripping unit 22 to swing up and down, making it difficult to accurately determine the position of the item P in the height direction (Z direction), and the item P would not be accurately placed in the placement position at the destination. The above configuration can suppress such adverse effects.

[0039] 〔summary〕 The ceiling transport vehicle according to aspect 1 of the present disclosure is a ceiling transport vehicle for transporting items, and comprises: a running section that runs along a track; a lifting body that is suspended from the running section so as to be able to rise and fall and that grips the item; and a sway suppression section that clamps the item to suppress swaying of the item. The lifting body has a main body section, a gripping section that grips the item, an elastic section that elastically supports the gripping section relative to the main body section, and a locking mechanism that locks the gripping section to a locked state that does not allow the elastic section to move relative to the main body section. The lifting body further comprises a switching section that switches the locking mechanism between a locked state and an unlocked state. After the item is lifted and the gripping of the item by the sway suppression section is completed, the switching section switches the locking mechanism from the locked state to the unlocked state.

[0040] According to the above configuration, the locking mechanism is unlocked after the sway suppression unit has completed clamping the item, so that the locking mechanism is unlocked before the sway suppression unit has completed clamping the item, thereby preventing the item from swaying or tilting.

[0041] In the ceiling transport vehicle according to aspect 2 of the present disclosure, in the above-mentioned aspect 1, the running unit starts running when the locking mechanism is in a locked state, and the vibration suppression unit starts clamping the item simultaneously with or after the start of the running.

[0042] According to the above configuration, since the article is still in a locked state when the travel starts, it is possible to prevent the article from shaking during travel.

[0043] The ceiling transport vehicle of aspect 3 of the present disclosure is, in aspect 1 or 2, provided with a fall prevention unit that prevents the item from falling by protruding a protrusion below the bottom surface of the item, and the fall prevention unit operates simultaneously with the sway suppression unit.

[0044] According to the above configuration, after the protrusion of the protrusion portion by the fall prevention portion in addition to the vibration suppression portion has been completed, the locking mechanism can be set to the unlocked state.

[0045] In the ceiling transport vehicle according to aspect 4 of the present disclosure, in any of aspects 1 to 3, when the vehicle stops at a predetermined stopping position after carrying the item and traveling, the switching unit switches the locking mechanism from the unlocked state to the locked state at a point where the vehicle is a predetermined distance ahead of the stopping position.

[0046] According to the above configuration, when stopping, the locking mechanism is switched from the unlocked state to the locked state at a point a predetermined distance before the stopping position, so that when the vehicle arrives at the stopping position, the locking mechanism is in the locked state and the next operation can be started promptly.

[0047] In the ceiling transport vehicle of aspect 5 of the present disclosure, in aspect 4, the sway suppression unit releases the clamping of the item after or at the same time as the switching unit switches the locking mechanism from the unlocked state to the locked state.

[0048] According to the above configuration, the clamping of the article by the sway suppression section is released in the locked state, thereby reducing the number of situations in which the article sways.

[0049] In the ceiling transport vehicle according to aspect 6 of the present disclosure, in aspect 4 or 5, when the lifting body is descending while holding the item, the switching unit switches the locking mechanism to the unlocked state when the item reaches its destination.

[0050] According to the above configuration, when the lifting body is lowering while gripping an article, the article remains locked until it reaches the destination, so that the article can be accurately placed at the placement position of the destination.

[0051] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0052] 1. Ceiling transport vehicle 10 Running part 20 Elevating body 21 Main body 22 Gripping part 23 Elastic part 24 Locking mechanism 30 Switching section 40 Vibration suppression unit 50 Fall prevention part

Claims

1. An overhead transport vehicle for transporting articles, a running unit that runs along a track; a lifting body that is suspended from the traveling section so as to be able to lift and lower and that grips an article; a vibration suppression unit that suppresses vibration of the article by clamping the article, The lifting body is a main body; a gripping portion that grips the article; an elastic portion that elastically supports the grip portion relative to the main body portion; a locking mechanism that locks the gripping portion so as not to allow the elastic portion to move relative to the main body portion, moreover, a switching unit that switches between a locked state and an unlocked state of the locking mechanism; The switching unit switches the locking mechanism from the locked state to the unlocked state after the item is lifted and the sway suppression unit has completed clamping the item.

2. the traveling unit starts traveling when the locking mechanism is in a locked state, The ceiling transport vehicle according to claim 1 , wherein the vibration suppression unit starts clamping the article simultaneously with or after the start of the travel.

3. a fall prevention part that prevents the article from falling by having a protrusion protrude below the bottom surface of the article; The ceiling transport vehicle according to claim 1 , wherein the fall prevention unit operates simultaneously with the vibration suppression unit.

4. When the robot stops at a predetermined stopping position after gripping the article and traveling, The overhead transport vehicle according to claim 2 , wherein the switching unit switches the locking mechanism from the unlocked state to the locked state at a point where the vehicle is a predetermined distance ahead of the stopping position.

5. The ceiling transport vehicle according to claim 4 , wherein the vibration suppression unit releases the clamping of the article after or simultaneously with the switching unit switching the locking mechanism from the unlocked state to the locked state.

6. 6. The ceiling transport vehicle according to claim 5, wherein, when the lifting body is lowering while gripping the article, the switching unit switches the locking mechanism to the unlocked state when the article reaches a transfer destination.

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