TWI382950B - Transfer system - Google Patents

Description

Transfer system

The present invention relates to a system in which a load table (heavy crane, overhead traveling vehicle, railed trolley, unmanned vehicle, etc.) and a scaffolding and the like are combined. More particularly, the present invention relates to systems for correcting the tilt of a transfer device.

When the article is transferred by a sliding fork or the like, it is known that the weight of the sliding fork itself or the load of the article is deformed. Therefore, Patent Document 1 discloses that the elevating table on which the sliding fork is mounted is tilted to correct the deformation of the sliding fork. In order to correct the correction correctly, the deformation of the sliding fork must be correctly detected. However, when a detector such as a strain gauge is used, the acceleration caused by the advancement and retreat of the sliding fork and the vibration cause an error, so that it is difficult to accurately detect the deformation.

[Patent Document 1] Japan Shikaiping 7-9811

The object of the present invention is to achieve the transfer of articles in a high speed, space saving, and low impact. An additional object of the invention of claim 2 is that the tilt detection can be performed without waiting for the advancement and retreat of the transfer device to be completed. An additional object of the invention of claim 3 is that the tilt of the transfer device can be detected more accurately.

The transfer system of the present invention is provided with: an arm capable of retreating freely a transfer system comprising: a transfer table for carrying out an article of articles by the transfer device; wherein at least two portions of the article table are provided at the same height as the article table mounting surface Marking; in the arm portion of the transfer device, a detecting means for detecting a height difference of the at least two portions of the mark; and a gap for determining a height position obtained by the detecting means is provided for moving the The tilting means of the carrier device tilting along the advancing and retracting direction of the arm portion.

Preferably, the marking is formed by a continuous line parallel to the article mounting surface. Preferably, the detecting means is constituted by at least one pair of optical sensors arranged at intervals along the advancing and retracting direction of the arm portion.

According to the present invention, the arm portion is advanced toward the article table side, and the height difference of the marks of at least two portions is detected. When the arm portion and the article mounting surface are parallel, the height difference between the marks does not occur when viewed from the detecting side; however, when it is not parallel, a height difference occurs between the marks. Therefore, in order to eliminate the gap and tilt the transfer device, the arm portion and the article mounting surface can be formed in parallel. When the arm portion and the article placing surface are formed in parallel, the impact when the article is received between the article table and the arm portion becomes small. Further, the stroke in which the arm is slightly lifted and lowered is shortened, so that the transfer time can be shortened and the space on the side of the article can be reduced. Thereby, it is possible to achieve low impact, high speed and space saving transfer.

Further, when the mark is constituted by a continuous line parallel to the article mounting surface, the mark can be detected over a wide range of the arm portion advancing and retracting. The mark of at least one part is first detected and its height is stored, and then the arm is detected to be tilted as long as the height of the mark is detected. Therefore, even if the arm does not enter or exit to a predetermined position, the tilt can be detected. Using the mark height difference to detect When tilting, the wider the interval between mark detection positions, the higher the accuracy. Therefore, if the detecting means is disposed at intervals in the advancing and retracting direction of the arm portion, the inclination of the arm portion can be more accurately detected.

The preferred embodiments for carrying out the invention are described below.

[Examples]

Fig. 1 to Fig. 8 show a stacker crane showing the transfer system of the embodiment. In each of the figures, 2 represents a lifting platform, for example, a lifting and lowering along a pair of towers 4, 4, and a trolley (not shown) of a stacking crane is provided at a lower portion thereof, and travels on a traveling rail (not shown). The trolley is provided with a motor for traveling and a lifting motor for the lifting platform 2. The elevating table 2 is composed of, for example, left and right guiding units 6, 6 and a linear moving guide (LM guide) 7, and is movable up and down along the tower 4. 8 represents the upper frame of the lifting platform 2, and is attached to the guiding unit 6 by the pins 10 and 12 with the latch 10 as a rocking center.

As shown in FIG. 2, the tilting mechanism 14 is attached to the guiding unit 6, and penetrates the long hole 18 provided in the upper frame 8 and the tilting mechanism 14, and is fixed to the nut 20 and the linear moving guide 24: nut The 20 series is moved left and right along the ball screw 21 by the tilt motor 22. 26 represents a guiding unit for guiding the linear movement guide 24. When the tilting motor 22 is actuated, the upper frame 8 and the tilting mechanism 14 move left and right with respect to the latch 12, but since the upper frame 8 cannot move left and right with respect to the latch 10, the lifting platform 2 moves left and right with the latch 10 as a fulcrum. . Knot As a result, the lifting platform 2 is inclined in the advancing and retracting direction of the sliding fork 16 .

Fig. 3 and Fig. 4, Fig. 30, represent the scaffold support members, which are provided along the scaffolding of the automatic warehouse for the stacking cranes, in which the pillars of the scaffold support member 30 and the like are omitted. The upper and lower linear marks 31 and 32 are provided so as to be parallel to the longitudinal direction of the scaffold support 30, in other words, parallel to the article placement surface of the scaffold support 30. The marks 31, 32 are, for example, optical marks using a color tape or the like. The slide type yoke 16 is fixed to the elevating table 2 with its bottom unit, and has an intermediate unit 34 and a top unit 35, and image sensors 36 and 37 are provided near the left and right ends of the top unit 35 at the front end. For example, the image sensors 36 and 37 use a one-dimensional optical sensor whose visual field direction is the vertical direction, but a CCD camera having a planar field of view or the like can also be used.

As shown in FIG. 4, when detecting the tilt of the top unit 35 against the scaffold support member 30, 40, 41 represents the field of view of the image sensors 36, 37 of FIG. 3, for example, the upper and lower two marks 31, 32 can be identified. The distance d1 and d2 between the average height and the center of the field of view are obtained. Further, when only one of the marks 31 and 32 can be detected, the height of the detected mark and the center of the field of view may be obtained. When the top unit 35 is horizontal, the height of the field of view and the heights d1, d2 of the marks 31, 32 are common to both. The difference between d1 and d2 represents the inclination of the top unit 35. By tilting the lifting table 2 by the tilting mechanism 14 of Fig. 2, the tilt of the top unit 35 of the sliding fork (corrected to 0) can be eliminated.

Fig. 5 shows the elevator control unit 50 and its periphery. 51 represents the lifting motor used to lift the lifting platform; 52 represents the driving sliding fork The drive motor for the sliding fork. 22 is the aforementioned tilting motor. The signals of the image sensors 36 and 37 are input to the tilt detecting unit 54, and the tilting of the top unit 35 of the sliding fork is detected based on the difference between d1 and d2 in Fig. 4. According to the difference between d1 and d2, the remaining lifting distance between the arrival and the scaffold support 30 for the degree of article reception can also be obtained. When the tilt detection is performed using the image sensors 36 and 37, it is necessary to detect the tilt after the at least one image sensor detects the marks 31 and 32. Then, when the top unit 35 starts to advance or retreat from the elevating table 2 or returns to the elevating table 2, the tilt correction pattern map at this time is stored in the correction pattern map storage unit 56. The data of the correction pattern storage unit 56 includes: a forward and backward position of the sliding fork, and a target inclination angle for distinguishing the loading or unloading. In the area where the image sensor cannot detect the marks 31, 32, the data of the correction pattern storage unit 56 is used to tilt the lifting table.

Figure 6 shows the transfer calculation steps of the embodiment. Until the image sensors 36, 37 are advanced into the scaffold support 30, the tilt of the sliding yoke cannot be detected. In the case of loading and unloading, the inclination of the advance and retreat amount with respect to the sliding fork 16 is measured in advance, and the correction pattern is stored. When the slide fork 16 starts to advance, the elevating table 2 is tilted in accordance with the information of the correction pattern storage unit 56 to advance the upper portion of the top unit 35 of the slide fork in a horizontal state. When the detector of at least one of the pair of image sensors 36, 37 detects the mark 31 or the mark 32, the mark height is stored. When the top of the top unit 35 is horizontal, there should be no change even if the sliding fork advances the height. Therefore, the elevating table is tilted in such a manner as to suppress the height variation with respect to the stored value. Keep the top of the sliding fork horizontal. When the left and right image sensors 36 and 37 detect the marks 31 and 32, the inclination of the upper surface of the top unit 35 can be accurately measured, and the inclination of the lifting table can be performed in a manner of eliminating the inclination.

When the sliding fork is advanced, the tilt of the sliding fork is detected by the image sensors 36, 37, and the tilting motor 2 is tilted by the tilting motor to perform the tilt correction, and the lifting platform 2 is The low-speed lift is switched to the micro-speed lift, during which the article between the scaffold support member 30 is instructed, and then the lift table 2 is again switched to the low-speed lift to end the transfer. During this period, since the load applied to the sliding yoke varies depending on the weight of the article, the inclination of the sliding yoke is also changed, and the inclination of the lifting platform 2 is performed in such a manner as to correct the inclination. After the receipt of the article, correct the tilt of the sliding fork and retreat.

Fig. 7 is a view showing the speed pattern of the lifting table of the embodiment and the conventional example. Although the lifting table is raised, the case of the lowering is the same. The collection of articles is carried out during the period in which the lifting platform is slightly increased. In the conventional example, since the sliding fork is deformed or the like, the height of the sliding fork cannot be correctly defined. Therefore, it is necessary to estimate the height change of the front end of the sliding fork caused by deformation or the like in advance, and therefore it is necessary to expand the micro-speed rising region. In this way, the transfer time is prolonged, and the lifting stroke of the sliding fork is increased during the transfer, and the storage efficiency of the articles on the scaffold side is deteriorated. In the embodiment, since the front end of the sliding fork can be kept horizontal, the bottom surface of the article and the upper surface of the sliding fork are initially in surface contact, so that the impact is small, and the vibration of the sliding fork after the receiving is small.

Fig. 8 is a view schematically showing the process of ascending from the slide fork 16 to the article 17 placed. In the embodiment, the elevating table 2 is tilted. Here, the two support portions that can independently adjust the height with respect to the elevating table 2 are used to tilt the entire sliding fork frame 16. The deformation is corrected on the side of the lifting platform 2, and the article is brought into contact with the article 17 while the sliding fork is horizontal. Therefore, the sliding fork and the article are in surface contact. When the slide fork 16 is unloaded to the scaffold support member 30, the article comes into surface contact with the scaffold support member 30 from the beginning, so that the impact of the article is reduced. Further, when the article is received, the load applied to the sliding fork is deformed to be deformed, and the lifting table is tilted so that the deformation can be suppressed. Therefore, the vibration generated by the deformation can be suppressed. Thereby, the article can be accepted with a very small impact, the micro-speed lifting time can be shortened, and the article can be transferred in a short time, and the top unit of the sliding fork can be advanced and retracted in a state of maintaining the level, thereby lifting the shed Shelf side containment efficiency.

The stacking device of the embodiment uses a stacker crane, but the same applies to an overhead traveling vehicle, an orbiting trolley, an unmanned vehicle, and the like. Further, in the case of a transfer system fixed to the ground by a combination of a lifting platform and a sliding fork, the embodiment in which the tilting mechanism is provided in the transfer device such as the sliding fork is similarly applied. In the embodiment, a sliding fork is used as the arm, but a multi-joint robot (SCARA arm) can also be used. In addition, it is also possible to replace a pair of left and right image sensors, and to use a CCD camera having a wide horizontal field of view, but the detection accuracy of the tilt is deteriorated.

2‧‧‧ lifting platform

4‧‧‧ tower

6‧‧‧Guide unit

7‧‧‧Linear moving guide (LM guide)

8‧‧‧ upper frame

10, 12‧‧‧ latch

14‧‧‧ tilting mechanism

16‧‧‧Sliding fork

17‧‧‧ Items

18‧‧‧ long hole

20‧‧‧ nuts

21‧‧‧Rolling screw

22‧‧‧ tilting motor

24‧‧‧Linear moving guide

26‧‧‧Guide unit

30‧‧‧ Scaffolding support

31, 32‧‧‧ mark

34‧‧‧Intermediate unit

35‧‧‧top unit

36, 37‧‧‧ image detector

40, 41‧‧ vision

50‧‧‧ Lifting Platform Control Department

51‧‧‧Moving motor

52‧‧‧Sliding fork drive motor

54‧‧‧ tilt detection department

56‧‧‧Revision pattern storage

Fig. 1 is a view showing a lifting platform of a stacker of the embodiment.

Fig. 2 is a view showing the tilting mechanism of the lifting platform of the embodiment.

Fig. 3 is a view showing an image sensor of the embodiment provided on the scaffold support member and provided on the top unit of the slide fork.

Fig. 4 is a view showing the tilt detecting method of the sliding fork of the embodiment.

Fig. 5 is a block diagram showing the elevation control unit of the embodiment, the lift motor around the periphery, the slide fork drive motor, the tilt motor, the tilt detecting unit, the storage unit of the tilt correction pattern, and the like.

Fig. 6 is a flow chart showing the transfer method of the embodiment.

Fig. 7 is a view showing the speed pattern of the lifting table of the embodiment (upper paragraph) and the conventional example (lower section).

Figure 8 is a schematic illustration of the process of lifting the article from the sliding fork and article contact until lifting the article from the scaffolding support.

2‧‧‧ lifting platform

16‧‧‧Sliding fork

30‧‧‧ Scaffolding support

31, 32‧‧‧ mark

34‧‧‧Intermediate unit

35‧‧‧top unit

36, 37‧‧‧ image detector

Claims (3)

A transfer system includes: a transfer device having an arm portion that can move forward and backward, and a transfer system configured to receive articles by the transfer device; wherein the article platform is Providing a mark formed by a continuous line parallel to the article placement surface of the article table and along the advancing and retracting direction of the transfer device; and a sensor for detecting the height of the mark on the arm portion of the transfer device, And a storage means for storing the height detected by the sensor; and a tilt detecting portion, which is determined according to the difference between the height of the mark detected by the sensor and the height of the mark stored by the storage means The tilting of the transfer device; in order to eliminate the tilt of the transfer device, a tilting means for tilting the transfer device in the advancing and retracting direction of the arm portion during the advance and retreat of the arm portion is provided. The transfer system of claim 1, wherein the mark is formed by two continuous lines that are parallel in parallel, and the sensor is configured to determine the average height of the two continuous lines as the height of the mark. The transfer system of claim 1 or 2, wherein the sensor is composed of at least one pair of optical sensors arranged at intervals along the advancing and retracting direction of the arm portion; The height of the mark detected by the optical sensor in front of the arm in the forward and backward direction is used in the forward and backward movement of the arm. The tilting means tilts the transfer device in the advancing and retracting direction of the arm portion, thereby eliminating the difference between the mark height detected by the optical sensor in the forward and backward direction of the arm portion and the stored height; In the raising and lowering of the arm portion, the transfer device is inclined in the advancing and retracting direction of the arm portion by the tilting means in accordance with the difference in the mark height detected by the pair of optical sensors.