JP3526014B2 - Transfer equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device.

[0002]

2. Description of the Related Art A transport device transports fragile items such as liquid crystal substrates,
When transferring a fragile item by the transfer device of the transfer device, the entire transfer cycle is performed at a low speed in order to prevent damage to the product. However, in this case, the transportation efficiency is low.

[0003]

An object of the present invention is to transfer an article with a relatively short cycle time while preventing damage to the article (claims 1 to 3).

[0004]

According to the present invention, in a transfer device in which a holder for holding an article is moved up and down by a lifter and moved forward and backward by a telescopic arm, a telescopic control section for driving the telescopic arm is provided. An elevating control section for driving the lifter is provided, and the article is transferred after the telescopic arm is extended at a low speed during extension during a unloading operation and at a high speed during extension during a loading operation. The lifter is moved up and down at high speed until the time of transshipment with the other party, slowed down before the timing of transshipment, accelerated after passing the timing of transshipment and then moved up and down at high speed, and then the unloading operation is performed. The retractable arm is retracted at a high speed at the time of retreating, and at a low speed at the time of retreating during the loading operation (claim 1).

Preferably, a turntable is provided to rotate the holder, and the turntable is rotated at the same angular velocity simultaneously with the extension of the telescopic arm and when the holder is empty and there is an article, Further, at the same time as the retractable arm is retracted, the holder is swung at the same angular velocity when the holder is empty and there is an article. More preferably, the transfer device is mounted on an article conveying device.

[0006]

In the present specification, the point of time at which the articles are transferred between the holder of the transfer device and the transfer partner is called the transfer timing. In this invention, the lifter is moved up and down at a high speed before the transshipment timing, at a low speed in the vicinity of the transshipment timing, and then at a high speed again after the transshipment timing is passed, so that the article is picked up by the holder or released from the holder. The impact at the moment of wear can be reduced, and damage can be prevented even for easily fragile products such as liquid crystal substrates. In addition, the cycle time can be shortened comparatively because it moves up and down at a high speed except near the transshipment timing. Further, not only the moment of the transshipment timing but also the vicinity thereof is moved up and down at a low speed, so that it is not necessary to know exactly when the transshipment timing occurs (claims 1 to 3). Therefore, according to the present invention, the article held by the holder is moved up and down by the lifter, and at the time of unloading, the holder is lowered at high speed.
Low-speed descending, high-speed descending in this order by the lifter, at the time of loading, the holder is lifted in the order of high-speed ascending, low-speed ascending, high-speed ascending, during the low-speed descending and low-speed ascending Is transshipped with the transfer partner.

Further, according to the present invention, when the holder is holding the article, the telescopic arm is extended at a low speed, and when it is not, the telescopic arm is extended at a high speed, so that vibration applied to the article and displacement of the article are prevented. However, the arm can be expanded and contracted in a relatively short cycle time. According to the invention of claim 3, the transfer device is provided in the transfer device such as the automatic guided vehicle, so that it is not necessary to provide the transfer device in the station such as the automatic warehouse or the processing device, and the number of transfer devices is reduced as a whole. be able to.

[0008]

1 to 4 show an example of application of a transfer device to an automated guided vehicle. The transfer device of the present invention may be applied to a transfer device of a stacker crane, a transfer device of a track guided vehicle, or the like, or the transfer device may be independently arranged in a transfer station. . In the embodiment, since the automatic guided vehicle is taken as an example, the transfer partner is referred to as a mounting table, but in the case of a stacker crane or the like, the shelf is the transfer partner. When the transfer device according to the present invention is mounted on the automatic guided vehicle, it is not necessary to provide the transfer device at a station such as an automatic warehouse or a processing device, and the number of transfer devices can be reduced as a whole. The transferred article is a fragile item such as a cassette containing a liquid crystal substrate, but is not limited to this.

FIG. 1 shows the structure of the automatic guided vehicle 2. Reference numeral 4 denotes a travel control unit, which travels so as to travel to a target position instructed by a control device (not shown) even if it has a travel route map. The mechanical unit 6 is controlled. When the automatic guided vehicle 2 stops near the target position, the position sensor 8 detects the stop position with respect to the mounting table or the like, and obtains the deviation from the position at the time of teaching.
In the embodiment, the detection of the shift of the stop position from the teaching time is performed in the horizontal plane. The position sensor 8 has only to detect the position of the automatic guided vehicle, and is not limited to the one for obtaining the deviation from the position at the time of teaching.

The position sensor 8 determines the shift of the stop position from the time of teaching, thereby determining the amount of expansion and contraction and the turning angle of the arm necessary for transfer. As the lift amount of the lifter, the value at the time of teaching is used as it is. Reference numeral 10 is a turning control unit for controlling the turntable 16, 12 is an expansion / contraction control unit for controlling an expansion / contraction arm 18 made of, for example, a scalar arm, and 14
Controls the lifter 20 with the lifting control unit. Telescopic arm 1
For example, a slide fork or the like may be used for 8, and if, for example, the root joint of the scalar arm can be rotated independently of the other joints, the scalar arm can turn the turntable 16
Will also serve. The lifter 20 may be provided at the tip of the telescopic arm 18, or the telescopic arm 18 and the turntable 16 may be mounted on the lifter 20 as long as the fork 22 can be raised and lowered. The fork 22 may be provided at the tip of the telescopic arm 18, the lifter 20, or the like, and may scoop the bottom surface of the article from below, or may grasp the projection at the top of the cassette or the like containing the article. The turntable 16 may be omitted.

The elevating controller 14 elevates and lowers the lifter 20 at high speed before the transshipment timing, elevates and lowers at a low speed near the transhipment timing, and elevates and lowers the lifter 20 again at a high speed after the transhipment timing. Preferably, the ascending / descending speed is kept low and constant near the transshipment timing. This is the same when unloading and loading,
In the case of unloading, a speed pattern of high speed descending, low speed descending at a constant speed (near the transfer timing to the mounting table), and high speed descending is adopted. In the case of loading, it takes a speed pattern of high speed rising, low speed rising at a constant speed (near the transfer timing to the mounting table), and high speed rising. High speed and low speed here are high speed and low speed as a relative comparison.

The extension / contraction control unit 12 allows the article to extend / contract.
The expansion / contraction speed of the arm 18 is changed depending on whether the article is held or not, and is set to a relatively low speed when the article is held and a relatively high speed when the article is not held. The turning control unit 10 turns the turntable 16 at the same time as the extension / contraction of the telescopic arm 18, and since the turning angle is small, it is not necessary to change the angular velocity between when there is an empty load and when there is an article.

FIG. 2 shows a timing chart at the time of unloading, and FIG. 3 shows a timing chart at the time of loading. FIG. 4 shows these control algorithms. Automated guided vehicle 2
When the robot stops near the target mounting table, the position sensor 8 detects the horizontal position with reference to the teaching time, and determines the expansion / contraction amount of the arm 18 and the rotation amount of the turning table 16. The operation during unloading will be described below. The telescopic arm 18 is extended at a low speed, and at the same time, the turntable 16 is rotated so that the telescopic arm 18 extends from the optimum direction to the mounting table.

When the expansion and contraction of the telescopic arm 18 is completed, the lifter 20 is lowered at a high speed before the transshipment timing, then at a low speed near the transhipment timing, and then at a high speed again after passing the transhipment timing. In the meantime, the articles are transferred from the fork 22 to the mounting table at the position where the transshipment timing is reached. At this time, the fork 22 is lowered at a low speed at the time of landing the article on the mounting table (reloading timing), so that it is possible to reduce the impact caused by the transshipment and prevent the article from being damaged. In addition, the cycle time can be shortened as compared with the case where the whole system is lowered at a low speed because the rate is lowered at a high speed except near the transshipment timing.

Since the flexure due to the weight of the article acts on the telescopic arm 18 and the position sensor 8 does not determine the position in the height direction, it is difficult to predict when the transshipment will occur. Therefore, in the embodiment, it is not necessary to know the transshipment timing itself by lowering the vicinity of the transshipment timing at a low speed and a constant speed.

When the operation of the lifter 20 is completed, the telescopic arm 18 is retracted at a high speed because there is no article in the telescopic arm 18, and at the same time, the turning table 16 is rotated to return to the original posture. By expanding and contracting the arm 18 at a low speed when the article is on the fork 22, and by expanding and contracting at a high speed when the article is not present, it is possible to prevent displacement of the article and damage due to vibration, etc. Reduce the cycle time.

The operation of loading is basically the reverse of unloading, the turntable 16 is rotated while the empty fork 22 is extended at a high speed, and then the fork 2 is lifted by the lifter 20.
2 is raised at a high speed to near the transshipment timing, then at a low speed and at a constant speed, and again at a high speed after the transshipment timing has elapsed. After that, the telescopic arm 18 is retracted at a low speed. For this reason, the cycle time can be shortened as compared with the case where the shock due to the transshipment from the mounting table to the fork 22 is minimized and the entire speed is increased at a low speed. Further, when the load is empty, the arm is extended at a high speed, and when there is an article, the arm is retracted at a low speed to prevent the article from being displaced or vibrating.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an automated guided vehicle equipped with a transfer device according to an embodiment.

FIG. 2 is a timing chart showing the expansion / contraction speed of the arm and the lifting speed of the lifter at the time of unloading, in the embodiment.

FIG. 3 is a timing chart showing the expansion / contraction speed of the arm and the lifting speed of the lifter during loading in the embodiment.

FIG. 4 is a flowchart showing the transfer algorithm of the embodiment.

[Explanation of symbols]

2 automated guided vehicles 4 Travel control unit 6 Travel mechanism 8 Position sensor 10 Turning control unit 12 Stretch control unit 14 Lifting control section 16 turntable 18 telescopic arm 20 lifters 22 fork

Claims (3)

(57) [Claims] 1. A transfer device in which a holder for holding an article is moved up and down by a lifter and is moved forward and backward by a telescopic arm, wherein a telescopic control unit for driving the telescopic arm and the lifter are provided. An elevating control unit for driving is provided so that the telescopic arm is extended at a low speed at the time of extension during the unloading operation and at a high speed at the time of extension during the loading operation, and then the article is transferred to or from the transfer partner. The lifter is moved up and down at high speed before the reloading timing, decelerated before the reloading timing, accelerated after moving through the reloading timing, and then moved up and down at high speed. The transfer device is characterized in that the retractable arm is retracted at a low speed during the backward movement in the loading operation. 2. A turntable is further provided to rotate the holder, and the turntable is rotated at the same angular velocity at the same time as the extension of the telescopic arm and when the holder is empty and there is an article, Further, at the same time as the retractable arm is retracted, and the holder is swung at the same angular velocity when the holder is empty and there is an article,
The transfer device according to claim 1, wherein: 3. The transfer device according to claim 1, wherein the transfer device is mounted on an article conveying device.