JP4715383B2 - Transport cart - Google Patents

Description

  The present invention relates to a transport carriage, and is particularly suitable for transporting a transported object such as a cassette for storing a semiconductor wafer, a liquid crystal, a magnetic disk, an optical disk, a compact disk and the like in a clean environment. It relates to a transport cart.

  Semiconductor wafers, liquid crystals, magnetic disks, optical disks, compact disks, and the like are manufactured in a clean room because fine particles such as dust greatly affect the accuracy and yield of products. In a clean room used for this kind of purpose, a system is constructed in which clean air flows down from the ceiling (down flow) and this clean air is exhausted from the entire surface of the floor, called a grating, which can be ventilated in a mesh shape. . And by this down flow, fine particles such as dust in the clean room are quickly discharged out of the clean room, thereby purifying the room.

  In such a clean room, a transport carriage for transporting the above-described transported object (such as a cassette containing semiconductor wafers) is disposed so as to be able to travel on a travel path on the floor or on a track provided on the floor. . When this transport carriage is driven to travel, turbulent flow is generated in the downflow, and dust and tire dust adhering to the grating are rolled up in the air by this turbulent flow, causing dust generation.

  In order to solve such problems, there have been contrivances such as molding the cart body into a shape that is unlikely to generate turbulence. However, no matter how much the shape of the cart body is modified, turbulence may be generated. Although it can be suppressed to a small value, it has been difficult to suppress dust generation. Therefore, in order to prevent the clean room and transported goods from being polluted by dust generated by turbulent flow, the conventional transport cart sucks the outside air containing dust with a suction fan and directs it toward the grating floor. A mechanism for forcibly exhausting air containing dust is provided.

Specifically, in Patent Document 1, a suction grill is provided on the upper surface of the transport carriage, outside air is sucked from the suction grill by a suction fan, and the outside air is discharged from a discharge hole disposed downward on the lower surface of the transport carriage. A conveying cart configured to discharge directly to the floor of the grating is disclosed (see Patent Document 1). Further, Patent Document 2 discloses that dust collected from a drive wheel is sent to a blower fan disposed downward in the lower center of the main body by a collecting fan provided in a motor for driving the drive wheel. Has been disclosed (see Patent Document 2).
JP-A-10-181882 JP-A-11-171337

  Certainly, like the carriages disclosed in Patent Document 1 and Patent Document 2 described above, air containing dust is sucked into the inside of the carriage, and this is exhausted directly from the discharge hole to the grating floor. For example, a certain effect can be expected to prevent contamination of clean rooms and transported goods due to dust generation.

  However, since it is difficult to suck the dust generated by the traveling of the transport carriage into the transport carriage without omission, it is impossible to completely suppress contamination due to the dust generation. On the contrary, by discharging air downward from the lower part of the main body, turbulent flow is likely to occur, and on the contrary, dust on the floor surface is wound up, which may cause such contamination. As described above, a clean room transport cart is expected to have a configuration that can effectively prevent dust generated by traveling.

  In view of the above, the present invention relates to a transport carriage that solves the above-described conventional problems, and an object thereof is to provide a transport carriage that can effectively suppress dust generation due to traveling.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, in a transport cart that travels in a clean room in which a large number of air exhaust holes are formed in a travel path, a cart main body provided with a transport object placing portion for placing a transport object, and the cart A blowout opening that is opened at the outer edge of the lower surface of the main body, and an air discharge means that discharges air obliquely downward from the blowout opening toward the center of the carriage main body and blows air on the upper surface of the traveling path. Is.

  According to a second aspect of the present invention, the exhaust means includes a ventilation duct that communicates with the outlet and is provided along an outer edge of the cart body, and a blower that blows air to the outlet through the ventilation duct. It is provided.

  According to a third aspect of the present invention, the air exhaust means is such that the flow velocity of the air discharged from the outlet is larger than the traveling speed of the cart body.

  As effects of the present invention, the following effects can be obtained.

  Since it was set as the structure shown in Claim 1, the air which is going to wind up around a trolley | bogie main body is forced by driving | running | working, blowing air on the upper surface of the driving | running | working path of the center part direction from the lower surface of a trolley | bogie main body. The air can be exhausted from the air to the exhaust hole, and dust generation due to traveling can be effectively suppressed.

  Since it was set as the structure shown in Claim 2, an exhaust means can be assembled | attached to a trolley | bogie main body with a simple structure.

  Since it was set as the structure shown in Claim 3, even if it receives the wind pressure at the time of driving | running | working, air can be accurately blown toward the center part of a trolley | bogie main body.

Next, the best mode for carrying out the invention will be described.
1 is a front view showing an overall configuration of a transport carriage according to an embodiment of the present invention, FIG. 2 is a bottom view of FIG. 1, and FIG. 3 is an enlarged view of the vicinity of a blowout opening opened on the bottom face of the carriage body. FIG. 4 is a bottom view, FIG. 4 is a longitudinal sectional view of the air outlet and the air direction adjusting member, and FIG. 5 is a diagram showing a ventilation path until the air in the ventilation duct is discharged from the air outlet.
Hereinafter, in FIG. 1, the front-rear direction of the transport carriage 10 is a horizontal arrow direction (X direction) in the figure, and the transport carriage 10 is configured to be able to drive in the X direction.

First, the overall configuration of the transport carriage 10 will be outlined below.
As shown in FIG. 1, the transport cart 10 is an automatic guided vehicle that is driven to travel along a travel path 1 formed on a floor surface of a clean room in a state where a transported object is placed. That is, the transport cart 10 automatically travels to a position where the transported material is delivered by a control device provided inside or outside, and transported between the transport cart 10 and the process device by a transfer device (not shown). Things are transferred.

  The clean room has a system in which a downflow, which is clean air, flows down from a ceiling (not shown), and the downflow is exhausted from the entire surface of the grating 1a in which a large number of ventilation holes that allow ventilation are formed in a mesh shape. Has been built. In this way, the downflow is constantly flowing down from the top to the bottom in the clean room, so that the air in the clean room is recirculated, and fine particles such as dust are quickly discharged out of the clean room, thereby purifying the room. Done.

  In the transport carriage 10, a transported article placement unit 12 is formed on the upper surface 11 a of the carriage body 11, and the transported article is placed on the transported article placement unit 12. In addition, a crane, a conveyor, a fork, etc. may be provided in the conveyance trolley 10 as a transfer apparatus, and the conveyed product mounting part 12 is formed in upper horizontal surfaces, such as this crane.

  Drive wheels 13 serving as traveling drive means for the carriage main body 11 are rotatably supported at the lower portion of the carriage main body 11, and the drive wheels 13 are rotated and driven by a drive motor (not shown) to convey the wheels. The carriage 10 is allowed to travel on the travel path 1. The drive wheel 13 is disposed at a position hidden by the cart body 11 in plan view, and is disposed such that the roller surface protrudes downward from the lower surface 11 b of the cart body 11. By arranging the drive wheels 13 in this manner, the transport carriage 10 can be configured compactly, and the separation H between the lower surface 11b and the floor surface is configured to be low. For example, when the transport carriage 10 is configured to be able to travel on a track, the drive wheel 13 as the travel drive means is shaped so as not to be removed from the track.

  As shown in FIGS. 1 and 2, the cart body 11 of the present embodiment is provided with the above-described drive motors and control devices for the drive wheels 13, and from the bottom surface 11 b of the cart body 11 to the center of the cart body 11. An air exhaust mechanism 2 is provided to exhaust air downward obliquely to the part. The transport carriage 10 is configured to travel while blowing air at a high speed on the upper surface of the traveling path 1 (the upper surface of the grating 1a) from the lower surface 11b of the cart body 11 toward the center of the body by the exhaust mechanism 2. ing.

  Specifically, the bogie body 11 has a plurality of air outlets 20, 20... Opened along the outer edge of the lower surface 11 b, and the air outlet 20. A ventilation duct 21 communicated with the external space through 20... And an axial fan 22 as a blower that sucks external air and sends it to the ventilation duct 21 are configured.

  As shown in FIG. 2, the air outlets 20, 20... Are arranged so as to have a substantially square shape in plan view with a predetermined interval on the outer edge of the lower surface 11 b. Specifically, the blowout ports 20, 20... Are provided along the shape of the lower surface 11b at the front and rear and left and right edges of the carriage body 11. The ventilation duct 21 and the external space of the carriage main body 11 are communicated with each other through the outlets 20, 20. However, the shape, the number, the arrangement, and the like of the blowout port 20 are not particularly limited. For example, the blowout port 20 is opened at the front and rear edges of the carriage body 11 and the left and right edges are opened. You may comprise so that a shape, a number, etc. may differ with the blower outlet 20. FIG.

  Here, as shown in FIGS. 3 and 4, a wind direction adjusting member 30 for discharging the air blown from the ventilation duct 21 in a predetermined direction is attached to the outlet 20. The wind direction adjusting member 30 includes a frame 30a formed in a rectangular shape so as to coincide with the shape of the opening of the outlet 20, and a long plate-like fin 30b bridged between a pair of opposing side walls of the frame 30a. -It is comprised with 30b .... The fins 30b are arranged at substantially equal intervals, and are attached to be inclined so as to obliquely intersect the vertical axis.

  In the present embodiment, the fin 30b is adjusted in inclination angle and direction so as to discharge the air in a predetermined direction. Specifically, the air in the ventilation duct 21 is supplied to each of the outlets 20, 20,. The direction and angle are adjusted so that the cart body 11 is discharged obliquely downward toward the center in a plan view of the cart body 11. The wind direction adjusting member 30 attached to the front and rear outlets 20, 20... Of the cart body 11 is configured such that the front wind direction adjusting member 30 discharges air toward the lower rear of the cart body 11. The rear wind direction adjusting member 30 is configured to be discharged toward the lower front side of the carriage main body 11. Similarly, the air direction adjusting members 30 provided on the left and right sides of the carriage main body 11 are also configured to discharge air toward the left and right central portions of the carriage main body 11.

  Note that the inclination angle of the fin 30b depends on the air volume / flow velocity of the air blown to the air direction adjusting member 30, the vehicle height of the conveyance carriage 10 (the separation H between the travel path 1 and the lower surface 11b of the carriage main body 11), the conveyance carriage, and the like. It is set according to the traveling speed of 10 or the like, and can be configured to be adjustable by rotating around the upper or lower part as a fulcrum.

  For example, the wind direction adjusting member 30 may project part or all of the fins 30b downward from the lower surface 11b of the carriage main body 11. Further, the wind direction adjusting member 30 is not necessarily provided in the transport carriage 10, and the shape is such that air is discharged obliquely downward toward the center of the carriage body 11 through the opening of the outlet 20 and the ventilation duct 21. And it is sufficient.

  As shown in FIGS. 1 and 5, the ventilation duct 21 is extended inside the cart body 11, and guides the external air sucked into the cart body 11 from the axial fan 22 to the outlet 20. Configured to do. In this embodiment, the ventilation duct 21 is composed of a horizontal duct 21a extending in the horizontal direction with respect to the carriage body 11 and a plurality of vertical ducts 21b, 21b,. ing.

  The horizontal duct 21a is extended below the interior of the carriage body 11 so as to have a substantially rectangular shape in plan view along the shape of the lower surface 11b, and communicates with the external space via the outlets 20, 20. Has been.

  The plurality of vertical ducts 21b extend from the horizontal duct 21a in a substantially vertical direction, and are connected so that one end communicates with the inside of the horizontal duct 21a. Specifically, the vertical duct 21b is connected to each of the horizontal ducts 21a on the left and right sides of the carriage body 11 and the horizontal ducts 21a on the front and rear sides. One or a plurality of blower chambers 11c in which an axial fan 22 is disposed are disposed above the carriage main body 11, and the other ends of the vertical ducts 21b communicate with the inside of the ducts in the blower chamber 11c. It is connected to the. The vertical duct 21b is tapered so that the duct gradually narrows as the distance from the connection with the blower chamber 11c increases (see FIG. 5), and the air blown from the blower chamber 11c is efficiently collected in the vertical duct 21b. It is configured as follows.

  In the ventilation duct 21, the air sucked into the blower chamber 11 c is sent from the blower chamber 11 c to the horizontal duct 21 a via each vertical duct 21 b and is circulated in the horizontal duct 21 a, and any one of the outlets 20. -It discharges from 20 ... to external space (refer the arrow in FIG. 5).

  In the present embodiment, the vertical duct 21 b connected to the horizontal duct 21 a on the front and rear sides (both sides in the X direction) of the transport carriage 10 is connected to the horizontal duct 21 a at a position directly above the outlet 20. Therefore, most of the air blown from the vertical duct 21b is discharged from the outlet 20 to the external space. On the other hand, the vertical duct 21b connected to the horizontal duct 21a on the left and right sides (both sides orthogonal to the X direction) is connected to the horizontal duct 21a at a position shifted in the front-rear direction from the position immediately above the outlet 20. Therefore, the air blown from the vertical duct 21b is discharged from the outlet 20 and a part of the air flows back through the horizontal duct 21a.

  In other words, the transport carriage 10 is configured such that the amount of air discharged from the outlet 20 opened to the front and rear sides is larger than the amount of air discharged from the outlet 20 opened to the left and right sides. By setting it as such a structure, the influence by the wind pressure at the time of the conveyance trolley | bogie 10 drive | working is reduced. However, the axial fan 22 disposed on the front and rear sides may be a fan having a large air volume.

  As shown in FIGS. 1 and 5, the axial fan 22 is housed in the air blowing chamber 11 c described above, and is attached so that the axial direction is substantially vertical. The air blowing chamber 11c communicates with an external space above the carriage main body 11 through an inlet 23 which is an upper surface 11a of the carriage main body 11 and is opened above the air blowing chamber 11c. When the axial fan 22 is rotated, air is sucked into the interior through the suction port 23, passes through the axial fan 22 in the rotation axis direction (vertical direction), and is connected to the lower portion of the blower chamber 11 c. The air is blown to the vertical duct 21b (see the arrow in FIG. 5).

  The air exhaust mechanism 2 configured as described above is configured such that the flow velocity of the air discharged from the air outlet 20 is at least greater than the traveling speed of the carriage main body 11. Specifically, in the transport carriage 10 that travels on the travel path 1 at a travel speed of about 2 to 3 (m / s), the flow rate of air discharged from the outlet 20 is about 5 (m / s). It is preferable to be configured as follows. By making the flow velocity of the air discharged from the blowout port 20 larger than the traveling speed of the transport carriage 10, even if it receives wind pressure when the transport carriage 10 travels, the blowout opening 20 is directed toward the center of the cart body 11. Air can be accurately blown onto the upper surface of the travel path 1.

  In order to increase the flow velocity of the air discharged from the outlet 20, first, a blower such as the axial fan 22 having a predetermined air volume / static pressure characteristic is used as a basic performance. Specifically, the external air sucked into the blower chamber 11c is provided with an air volume / static pressure characteristic that allows the external air to be discharged at a predetermined flow rate from the outlet 20 toward the upper surface of the travel path 1 through the ventilation duct 21. Things are used. Further, the ventilation duct 21 is preferably short.

  As described above, the transport carriage 10 of the present embodiment includes the above-described air exhaust mechanism 2, so that the air sucked into the ventilation duct 21 by the axial fan 22 is sent from the outlet 20 to the center of the carriage body 11. It is possible to travel while spraying downward on the upper surface of the traveling path 1 (upper surface of the grating 1a) toward the lower part (see FIG. 1).

  When air is blown from the outlet 20 toward the central portion of the cart body 11, the central portion of the lower surface 11b of the cart body 11 is sealed, so that the air that has gone out of place is forced downward to the grating 1a. Exhausted. Therefore, the air that is about to wind up around (especially between the transport carriage 10 and the travel path 1) can be forcibly exhausted below the grating 1 a by the travel of the transport carriage 10. Turbulent flow in the lower part of the vehicle is suppressed, so that dust or the like on the travel path 1 is not scattered around the transport carriage 10. Further, since the surrounding air is forcibly exhausted below the grating 1a, the air discharged from the outlet 20 does not necessarily need to be clean air, and a filter or the like is not necessary. Furthermore, since the dust exhaust mechanism 2 described above exhausts dust to the lower side of the grating 1a to suppress dust generation due to running, the upper shape of the carriage body 11 can be freely designed.

  In particular, in this embodiment, as the air exhaust mechanism 2, the air outlet 20 opened at the outer edge of the lower surface 11 b of the cart body 11, and the air duct provided along the outer edge of the cart body 11 connected to the air outlet 20. 21 and the axial flow fan 22 that blows air to the outlet 20 through the ventilation duct 21, and can be assembled to the cart body 11 with a simple configuration.

Hereinafter, another embodiment of the transport carriage 10 described above will be described.
In the present embodiment, an example in which the conveyance cart is applied to an unmanned unmanned conveyance cart has been described, but the conveyance cart is not limited to this configuration, and the cart is run along a track provided on a ceiling or a floor surface. The present invention can also be applied to a tracked transport cart, and may be a manned transport cart.

  In order for the air exhaust mechanism 2 to accurately blow from the outlet 20 toward the center of the carriage main body 11 toward the upper surface of the traveling path 1 while the transport carriage 10 is traveling, the lower surface 11b of the carriage main body 11 and the floor surface A configuration in which the separation H is as short as possible is preferable (see FIG. 1).

  The ventilation duct 21 is not limited to the above-described configuration. For example, the ventilation duct 21 extends not only inside the cart body 11 but also protrudes laterally along the shape of the lower portion of the side wall outside the cart body 11. You may comprise. Moreover, if the ventilation duct 21 is not only the structure which consists of the horizontal duct 21a and the vertical duct 21b but the structure which guides the ventilation from the ventilation chamber 11c to the blower outlet 20, for example, it will blow off from each ventilation chamber 11c. It may be extended while being bent (curved) so as to blow directly to the mouth 20. The horizontal duct 21a is extended in consideration of the arrangement configuration when the lower surface 11b cannot be smoothed due to the handling of rails, power supply devices, and the like extended to the travel path 1.

  The type and number of the blower are not particularly limited, and in addition to the axial fan 22, a centrifugal fan, a mixed flow fan, a blower, or the like can be used. Etc. may be used in combination. Moreover, the structure of the blower outlet 20, the ventilation duct 21, and the ventilation chamber 11c mentioned above can be changed according to the kind and number of blowers to be used. The suction port 23 may be configured to open on the side wall of the carriage body 11 or to protrude from the upper surface 11a.

  When a line flow fan is used as the blower, the line flow fan is disposed inside the ventilation duct 21 (horizontal duct 21a) and the exhaust port is located above the blowout port 20, and the exhaust The air exhausted from the mouth is attached so as to be exhausted to the central portion of the carriage body 11 through the outlet 20. When a line flow fan is used, the above-described wind direction adjusting member may not be provided. Moreover, it can comprise so that air may be discharged | emitted directly toward the center part of the trolley | bogie main body 11 from a line flow fan, and it does not necessarily need to provide other fans etc. by the ventilation capability of a line flow fan. Further, as described above, the large-scale handling of the ventilation duct 21 is not necessary, and the carriage main body 11 can be configured compactly.

The front view which showed the whole structure of the conveyance trolley | bogie which concerns on one Example of this invention. The bottom view of FIG. 1 similarly. The enlarged bottom view of the vicinity of the blowout opening opened on the bottom surface of the cart body. The longitudinal cross-sectional view of a blower outlet and a wind direction adjustment member. The figure showing the ventilation path | route until the air in a ventilation duct is discharged | emitted from an outlet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Traveling path 1a Grating 2 Exhaust mechanism 10 Conveyor trolley 11 trolley | bogie main body 12 Conveyed material mounting part 20 Outlet 21 Ventilation duct 21a Horizontal duct 21b Vertical duct 22 Axial fan

Claims (3)

  In a transport cart that travels in a clean room with a large number of exhaust holes formed in the travel path, the transport body is provided with a transport body placing portion for placing a transport object, and is opened at the outer edge of the lower surface of the cart body. And a blow-out means for discharging air obliquely downward from the blow-out opening toward the center of the carriage main body and blowing air on the upper surface of the travel path.   The air exhaust means includes a ventilation duct that is communicated with the outlet and provided along the outer edge of the cart body, and a blower that blows air to the outlet through the ventilation duct. The conveyance cart according to claim 1, wherein   The conveyance cart according to claim 1 or 2, wherein the air exhaust means has a flow velocity of air exhausted from the outlet, which is higher than a traveling speed of the cart body.

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