JP3373959B2 - Four-wheel steering automatic guided vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-wheel steering automatic guided vehicle capable of traveling stably on two taxiways both in traveling and traversing. 2. Description of the Related Art When transferring goods in a clean room such as a semiconductor manufacturing plant, an automatic guided vehicle is used. In this method, a magnetic or optical guideway is laid along a traveling process in a factory that runs in advance, and a guided vehicle is automatically guided by the guided route and generally runs on the underside of the guided vehicle. As shown in the figure, three running wheels are arranged while maintaining a relative relationship such that a straight line connecting the wheels becomes a triangle, and all three running wheels are provided with a running drive motor and steering means. . [0003] Therefore, in a three-wheeled automatic guided vehicle, guided traveling is possible on two guided paths when traveling, but when traveling in a traverse, all three wheels, that is, three guided paths are required. It will be. In a clean room such as a semiconductor manufacturing plant, an opening for the downflow is generally formed on a floor surface on which a guide path is laid in order to secure a downflow by clean air. Therefore, if three traversing guideways are laid, the opening area of the floor surface will be reduced accordingly, and sufficient clean air downflow cannot be ensured. And the configuration is complicated and expensive. According to the present invention, of the four traveling wheels provided on the carrier, the traveling motor is disposed only on two traveling wheels on the diagonal line of the carrier and all the wheels are operated by steering means provided on all the wheels. Independently operated to achieve stable running on two taxiways for both running and traversing, and to increase the floor opening area for downflow. [0005] Means for Solving the Problems] The invention was made in order to achieve the above object, down by clean air
In an automatic guided vehicle capable of switching between traveling and traversing on a floor surface having a flow opening formed therein, the steering angle can be independently controlled on four traveling wheels provided on the lower surface of the carrier. A steering means is provided, and a traveling drive motor is provided on two traveling wheels arranged on a diagonal line of the carrier to enable traveling / traversing .
The gist is that a taxiway for traversing is arranged . [0006] Of the four running wheels provided on the lower surface of the carrier, only two running wheels diagonally to the carrier are driven by the drive motor, and the remaining two wheels are free rollers.
In addition, since all four wheels can be independently controlled for steering, the driving force for the carrier is balanced, running stability is obtained, and it is possible to use two taxiways for both traveling and traversing. Therefore, it is possible to secure a large downflow opening area on the floor surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A four-wheel steering automatic guided vehicle according to the present invention will be described below with reference to an embodiment shown in the drawings. In the figure, reference numeral 1 denotes a traveling carrier of an unmanned carrier. Although not shown, a battery, a driving device, a control circuit, a device for loading / unloading articles to be carried are provided on the carrier, and a lower surface of the carrier Has four running wheels 21, 22, 2
3, 24 are provided. The traveling wheels 21, 22, 23, 24 are supported by the carrier 1 so that the traveling direction can be arbitrarily changed, that is, the vehicle can be steered, and each traveling wheel has an independent steering direction angle. The steering motors 4 so that they can be controlled
1, 42, 43 and 44 are provided. [0009] Steering motors 41, 4 provided for each running wheel
2, 43, and 44 are provided on a traveling wheel mounting frame or a base, or are disposed on the carrier 1 as shown in the figure, and a rotating frame of the traveling wheel mounting frame and a steering motor are connected by a belt. The direction and angle of the running wheels are controlled independently. The two traveling wheels 21 and 23 on the diagonal line with respect to the carrier 1 are provided with traveling drive motors 3 and 3, respectively, and the traveling wheels 21 and 23 are rolled to travel the carrier 1. Make it possible. In this case, when driving straight, 2
The two running wheels 21 and 23 are rotated at a constant peripheral speed, and when turning, the vehicle can travel with the peripheral speed controlled according to the curve. Numerals 51 and 52 are guideways for traveling of the carrier, and 53 and 54 are guideways for traverse.
When the front and rear running wheels 21 and 24 and 22 and 23 are arranged in a straight line, the front and rear running wheels 21 and 52 are arranged in parallel so as to be equal to the interval between the left and right running wheels 21 and 22. As shown in FIG. 2, the traveling guideways 53 and 54 are turned 90 degrees from the traveling state of the carrier vehicle, that is, the traveling state, as well as the traveling guideways 53 and 54, as shown in FIG. In this state, the left and right running wheels 21 and 22 are arranged in a straight line, and are arranged in parallel with the interval between the front and rear running wheels 21 and 24. The width of the traversing guideway is also made equal to the width of the traveling guideway. In order for the automatic guided vehicle constructed as described above to travel, two traveling wheels 21,
By driving the traveling drive motors 3, 23, the transport vehicle 1 travels straight along the guideways 51, 52 together with the driven wheels 22, 24 on the other diagonal lines. At this time, since the driving wheels for driving are arranged on the diagonal line of the transport vehicle, the driving force on the transport vehicle is balanced, and running stability can be obtained. Further, since the four wheels are provided with steering motors independently of each other, even when the running wheels are steered and traversed, the driving wheels are arranged on a diagonal line as in the case of running, so that stability is maintained even when traversing. And steering can be performed smoothly, stably and reliably. According to the four-wheel steering automatic guided vehicle of the present invention, the four running wheels provided on the lower surface of the carrier are provided with steering means capable of controlling the steering angle independently of each other. Since the traveling drive motors are provided on the two traveling wheels arranged on the diagonal of the car, traveling stability can be obtained, driving can be easily performed, and two taxiways can be used even when traversing. Therefore, there is an advantage that the opening area for downflow on the floor surface can be secured wider than before.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a bottom view of a transport vehicle showing an embodiment of a four-wheel steering automatic guided vehicle according to the present invention. FIG. 2 is a bottom view of the transport vehicle at the time of traversing. FIG. 3 is a plan view of the carrier. FIG. 4 is a bottom view of a known example during traveling of a transport vehicle. FIG. 5 is a bottom view at the time of traversing. [Description of Signs] 1 traveling carrier 21, 23 driving traveling wheels 22, 24 driven traveling wheels 3 traveling driving motor 4 steering motors 51, 52 traveling taxiways 53, 54 traversing taxiways

──────────────────────────────────────────────────の Continuing on the front page (72) Koji Eguchi 3-11-1, Shimosakabe, Amagasaki-shi, Hyogo Nikkachi Electric Industrial Co., Ltd. (72) Inventor Harumasa Yamamoto 3-11, Shimosakabe, Amagasaki-shi, Hyogo No. 1 Nippon Kiden Kogyo Co., Ltd. (72) Inventor Kunihiko Nishibe 3-1-1, Shimosakabe, Amagasaki City, Hyogo Prefecture Institution (72) Nichichi Kiden Kogyo Co., Ltd. Tomohiro Maeda 3 Shimosakabe, Amagasaki City, Hyogo Prefecture JP-A-5-119042 (JP, A) JP-A-56-8758 (JP, A) JP-A-60-166554 (JP, A) JP-A-58-44515 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05D 1/02

Claims (1)

(57) [Claims] [Claim 1] For downflow by clean air
In an automatic guided vehicle capable of switching between traveling and traversing on a floor with an opening formed therein, four traveling wheels provided on the lower surface of the carrier are provided with steering means capable of independently controlling a steering angle. To be installed and arranged on the diagonal of the carrier 2
A traveling drive motor is provided on one traveling wheel to enable traveling / traversing , and for traveling and traversing of each two carriers.
A four-wheel-steering automatic guided vehicle, characterized by the arrangement of taxiways .