Bidirectional telescopic device of small rail car

Abstract

The invention provides a bidirectional telescopic device of a small rail car, and belongs to the technical field of automatic material carrying. The bidirectional telescopic device of the small rail car comprises a fixing plate, an upper sliding plate is arranged below the fixing plate in a sliding mode, a lower sliding plate is arranged below the upper sliding plate in a sliding mode, the sliding direction of the upper sliding plate is the same as that of the lower sliding plate, and a driving mechanism is arranged between the fixing plate and the upper sliding plate. A linkage mechanism is arranged between the upper sliding plate and the lower sliding plate, and a clamping device is arranged below the lower sliding plate. A first sensor and a second sensor are fixed to the two ends of one side of the lower surface of the fixing plate correspondingly, and an original point sensor is fixed to one end of the other side of the lower surface of the fixing plate. According to the invention, not only is the cost saved, but also the movement time is saved, and the clamping device can be protected when the driving motor fails and does not run according to the set stroke.

Description

technical field [0001] The invention belongs to the technical field of automatic material handling, and relates to a rail trolley, in particular to a bidirectional telescopic device for a rail trolley. Background technique [0002] In the AMHS (Automatic Material Handling System) system, the track trolley (OHT) runs along the track, and the track is fixed on the ceiling of the semiconductor manufacturing workshop. Normally, each semiconductor device is equipped with a Loadport (loading and unloading device). The Loadport is located directly under the rail trolley, and the rail trolley can grab or put down the load on the Loadport. If only like this, the track car needn't stretch out or retract along the direction perpendicular to the track. But in the following cases, the track car needs to be able to extend or retract along the direction perpendicular to the track. [0003] 1. When there is an exchange station or OHB (over-the-air buffer station) between the two tracks, o...

AI Technical Summary

Problems solved by technology

There may be installation errors, resulting in a positional deviation between the Loadport and the OHT perpendicular to the direction of the track. When this deviation exceeds the allowable deviation for the OHT to grab the load, it is necessary for the OHT to expand and contract in a direction perpendicular to the track. That is to say, OHT is required to be able to scale horizontally, and the existence of this deviation may be bidirectional, so OHT is required to be able to perform bidirectional horizontal scaling

[0005] 3. For a more flexible layout of the semiconductor workshop, if the OHT cannot expand and contract in the direction perpendicular to the track, the Loadport of each device in the semiconductor workshop must be directly below the track, which is completely restricted by the erection of the track

Because of the different dimensions of semiconductor equipment, or because of obstacles (such as columns) in the semiconductor workshop, some Loadports cannot be installed just below the track, and because the semiconductor workshop is expensive, it may not be possible for the Loadport to be located directly below the track. To make full use of the space, there is a problem of wasting cost. In these cases, it is necessary for the OHT to have the function of being able to expand and contract in the direction perpendicular to the track.

[0006] In order to increase the telescopic length of the OHT, an upper and lower two-layer motion mechanism is usually used. The traditional upper and lower two-layer motion mechanism generally uses two driving elements, that is, the upper layer and the lower layer each have a driving element driven by a motor or a cylinder. This technology is adopted. The produced OHT has the following disadvantages: first, the production cost is too high; second, the control is more complicated, and the error or failure rate increases; third, the upper and lower layers of moving parts may move asynchronously, resulting in low work efficiency.

In addition, if the drive mechanism fails to operate according to the set stroke during the two-way telescopic process, it will cause the upper moving parts to move out of its stroke range, which may affect the use of the upper moving parts, and there are potential safety hazards

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