JPH0158021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a conveyance system, and particularly to a conveyance method that reduces waiting time for a conveyance request and conveys without congestion.

[Technical background of the invention and its problems]

For example, in a semiconductor process, when transporting objects such as silicon wafers between stations A to F, as shown in FIG. This is done by moving in the direction. Note that each of the stations A to F has a lead-in track 2a branched from the loop-shaped track 2, respectively. As an example, when transporting from station E to station B, first, the transport vehicle 1e in the waiting zone 3 goes to station E in response to a transport request from station E, loads the transport object, and
After going to station B and unloading the goods, when the car becomes empty, it returns to the waiting zone and waits for the next transport request. Similarly, when transporting from station A to station F, the transport vehicle loads the goods from the waiting zone at station A, moves in the direction of the arrow, passes through the loop-shaped track 2, and goes to station F. After putting it down, return to the standby zone again. Transport between each station is carried out by constantly repeating such operations.

In the prior art, when a car becomes empty, it always returns to the standby zone to wait for a transport request, which increases the number of times the empty car moves on the track and lengthens the time it occupies the track. Therefore, congestion occurred on the track, and the time from when a transport request was issued until the actual transport was completed was long, and the transport capacity was limited.

Therefore, there is a need for a transport system that is space efficient and has a high transport capacity that can solve these problems.

[Purpose of the invention]

In a transport method in which the object is transported to a plurality of stations provided on each of a plurality of pull-in tracks connected to a loop-shaped track by a plurality of transport vehicles traveling in a fixed direction on the loop-shaped track, the object is transported after being transported. An empty conveyance vehicle is placed on standby in the lead-in track of a station that is located in front of a specific station that is frequently transported in the above-mentioned fixed traveling direction and that is rarely transported, or it is placed on a branch track within a loop-shaped track. is set up and placed on standby on either or both of the branch track and the lead-in track,
This waiting transport vehicle is made to travel in response to a transport request from the specific station.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Note that the same parts as in FIG. 3 used to explain the prior art are given the same symbols, and detailed explanation will be omitted.

As shown in FIG. 1, if among the stations A to F, the station that is transported a particularly large number of times is designated as a specific station B, and conversely, the stations that are transported less frequently are designated as A and F, then the loop-shaped trajectory Empty carriers 1a and 1b are always kept on standby on the pull-in tracks 2a of stations A and F, where the moving direction of the carriers 1a to 1e, which move in the direction of the arrow along 2, corresponds to the front side. Then, in response to a transport request from station B, which has a large number of transports, an empty vehicle at a closer station A, such as a transport vehicle 1a, goes to station B, loads the goods, and then goes to the destination station and unloads the goods. The empty transport vehicle 1b from station F goes to station A, which is no longer empty, or a nearby transport vehicle that has become empty at another station goes there and waits for the next transport request. . For example, when a waiting vehicle arrives at station A or station F with a load, after the empty vehicle leaves station F, the empty vehicle reenters station F's lead-in track 2a and waits. Repeat operation.

According to the transport method of the embodiment, the congestion on the track caused by empty cars that occurred in the conventional technology can be eliminated, and the loss time can be reduced in response to transport requests from stations that have a large number of transports, thereby improving the capacity of the entire transport system. can be made,
Very high conveying capacities can be achieved. Also, because the waiting zone can be reduced,
Space can be used effectively.

In addition, as a place for empty cars to wait, it is not limited to the station, but as shown in Figure 2, empty cars can be made to wait at the branch track 2b provided in the loop-shaped track, or between the branch track 2b and the pull track. The same effect can be obtained even if either one of 2a is operated on standby. Further, both a station and a bypass may be used as a waiting area for empty cars.

〔Effect of the invention〕

According to the present invention, congestion on the tracks due to empty cars is eliminated, and furthermore, it is possible to reduce loss time in response to transport requests from stations that have a large number of transports, so the capacity of the entire transport system can be improved, which is extremely High conveyance capacity can be achieved. Furthermore, since the number of waiting zones can be reduced, space can be used effectively.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conveyance method according to one embodiment of the present invention, FIG. 2 is an explanatory diagram of a conveyance method according to another embodiment of the present invention, and FIG. 3 is an explanatory diagram of a conventional conveyance method. A to F: Station, 1a to 1e: Transport vehicle, 2: Loop-shaped track, 2a: Retraction track, 2
b: Branched trajectory.

Claims (1)

[Scope of Claims] 1. A transport method in which objects are transported to a plurality of stations provided on each of a plurality of retraction tracks connected to a loop-shaped track using a plurality of transport vehicles running in a fixed direction on the loop-shaped track. , the conveyance vehicle, which has become empty after conveying the conveyed object, is placed in the above-mentioned pull-in track that is located in front of the specified station in the fixed traveling direction and connected to the station that is conveyed less frequently than the specific station that is frequently conveyed. A transportation method characterized in that the transportation vehicle is placed on standby and the transportation vehicle that is on standby is caused to travel in response to a transportation request from the specific station. 2. The transportation system according to claim 1, wherein a branch track is provided within the loop-shaped track, and the empty conveyance vehicle is made to wait on either or both of the branch track and the pull-in track. Method.