JPS62140904A - Arm support structure in stacker crane - Google Patents

Abstract

PURPOSE:To prevent a small article from being damaged when it is taken out, by detecting a load exerted to the front end of an taken out, by detecting a load exerted to the front end of an arm in a stacker crane so that the operation of the stacker crane is stopped when the detected load is abnormal. CONSTITUTION:If an article A set on a fork 18 at the front end of an arm 12 is caught on one end of a storage rack which is not shown, and is raised as it is, an arm base plate 13 in inclined rightward down. Thereby, a left microswitch 30 is turned off to stop the operation of a crane. On the other hand if the article is caught while it is lowered, the arm base plate 13 is inclined leftward down so that a right microswith 30 is turned off, resulting in that the operation of the crane is stopped. With this arrangement it is possible to prevent a small article and the arm from being damaged when the article is taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a support structure for an arm in a stacker crane that handles small articles such as containers, particularly with safety in mind.

(Prior art) A stacker crane, which is attached to a vertically movable carriage attached to a column with an arm that is telescopic and movable from side to side, is installed in a passageway between storage transoms with grid-like openings. A storage shelf equipped with a conveying device that moves back and forth and extends its arm at a desired location to take out or store small items is well known.

In such a stacker crane, the movement of the column, carriage, and arm that reciprocate on the rail is controlled by a computer, but in the unlikely event that there is a misalignment in the relative relationship between the arm and the storage shelf, small items or Usually, there is no means to detect when the tip of the arm gets caught on a storage shelf.

(Problems to be Solved by the Invention) Normally, in a storage shelf, small items are not necessarily placed symmetrically with respect to the center line of the shelf, and the arms are also not necessarily placed in the center of the shelf. Because it does not stop in alignment with the line, when the tip of the arm lifts and pulls out small items, the small items may hit the inside of the shelf or be pressed against the ceiling, causing damage, or the arm may be damaged. There was a problem.

Especially when the small item is an expensive semiconductor wafer,
If these are damaged and become defective, the loss will be large.

(Means for solving the problem) The present invention provides a detection means for detecting abnormal force applied to the fork at the end of the arm of the stacker crane and stopping the operation of the stacker crane.
An object of the present invention is to provide an arm support structure for a stacker crane that can prevent damage accidents when taking out small articles.

That is, in the stacker crane according to the present invention, a carriage is mounted on a vertical column that can be moved by being guided by a horizontal rail so as to be able to move up and down, and an arm equipped with a fork for placing an article on the upper surface is attached to the carriage. In the stacker crane provided, the retranslation arm is supported by the carriage with a required biasing force so that it can be in a horizontal state when unloaded and slightly tilted when loaded, and a sensor for detecting the amount of inclination of the arm. Means is provided so that the operation of the stacker crane can be stopped when the fork is overloaded.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

- (1) is a storage, which is equipped with a pair of left and right storage shelves (3) and (4) that open toward the central passage (2).

Rails (5) and (6) are installed above and below the central passageway (2), facing in the front-rear direction.

(7) is a stacker crane, which includes a truck (8) guided by a lower rail (6), and a column (9) supported by this truck (8) and whose upper end is guided by the rail (5).
and a carriage (11) that moves up and down along a pair of left and right vertical rails (10) provided in front of this column (9).
It is roughly composed of. Since these driving means and structures are well known, detailed explanation will be omitted.

(12) is an arm, and a movable arm (15) and a fork (18) are respectively attached to a fixed arm (14) fixed to an arm board (13) so as to be movable relative to each other. It can be expanded and contracted in any direction.

The combined structure of these components will be explained in more detail with reference to FIG. 4. The arm board (13) is a groove material whose top surface and left and right end faces are open, and an inward facing groove is laid on the inner surface of the arm board (13). A fixed arm (14) is formed by a pair of front and rear groove members (14b) having grooves (14a).

The movable arm (15) has a groove material (15c) having an outward groove (15b) fixed to the front and rear end surfaces of the horizontal plate (15a), and is suspended from the lower surface near the front and rear end surfaces of the horizontal plate (15a). Axle (16) pivoted to hanging piece (15d)
(16) is guided by the groove (14a) of the fixed arm (14), so that it is movable left and right along the fixed arm (14).

A fork (18) for placing a small article (A) has an axle (17) (1
7) can move relative to the movable arm (15) by being guided by the groove (L5b) of the movable arm (15).

Reference numeral (19) shown in FIG. 3 is a driving means consisting of, for example, a motor, which is attached to a mounting plate (20) protruding rearward from the lower surface of the left end of the arm board (13). 19), the moving arm (15), and the fork (18) are linked to each other by a known linking means consisting of a chain and a splot (not shown).

Therefore, when the motor (19) rotates normally, the movable arm (15) is guided to the fixed arm (14) through the linking means as described above, and the fork (18) is guided to the movable arm (15). They are guided and stretched to the right one after another, and on the upper surface of the fork plate (18), the storage shelf (3) (
4) After scooping up the small article (A) from below on the shelf (B), return the moving arm (15) and fork (18) and move the small article (A) to the central passage (2). The small articles (A) can be carried to an exit (not shown) by pulling out and then moving the stacker crane (7). Note that since these operations and configurations are well known, detailed explanations will be omitted.

Next, the support structure of the arm (12), which is the main part of the present invention, will be explained. As shown by the broken lines in FIG. 3, the left and right side plates (lla) and (llb) of the rectangular frame-shaped carriage (11) have a pair of parallel mounting plates (21) (21) in the front and rear, respectively. A support 1 (22) is provided that protrudes and has a horizontal piece (22a) at the free end of the mounting plate (21).
are installed respectively.

(23) is a bolt for horizontal adjustment, and the horizontal piece (22a
) and is screwed into the female thread, and the lower end is fitted with a nut (
24) are screwed together to prevent removal.

The arm board (13) is supported by the four bolts (23) mentioned above, and the inclination of the arm (12) can be adjusted by moving the bolts (23) up and down, but it is in a horizontal state when no load is applied. . 1 set of left and right front and rear mounting plates (2
1) In the middle part of (21), a spacer (25) with an inverted cross-section, consisting of a vertical plate (25b) connected to the side edge of a top plate (25a), is installed so as to face the front and rear directions. has been done.

(26) is a set of left and right bolts that penetrate the arm board (13) and the top plate (25a) of the spacing member (25), respectively.
A double nut (27) is screwed into its lower end.

Between the top plate (25a) and the double nut (27),
A pair of upper and lower spring seats (2
8) is fitted and inserted, and a coil spring (29) is compressed between these spring seats (28), so that the arm board (13) is always directed downward so as to be in contact with the four bolts (23). is energized by

(30) is a detection means for detecting the load on the arm (12);
For example, with a microswitch, one set of left and right spacing members (2
rollers (30b) attached to the vertical plates (25b) of 5) and pivoted to the free ends of the swinging pieces (30a);
In an unloaded state, both contact the lower surface of the arm board (13) and are turned on, and this signal is input to the computer that controls the stacker crane (7).

As shown in Fig. 5, when the stacker crane is in operation, small articles (A) at the tips of the forks (18) are caught on the shelves (B) of the storage shelves (4), and the carriage (11) is raised. If the arm board (13) is tilted, the right side of the arm board will be tilted down, as shown by the phantom line.
The left microswitch (30) is turned OFF.

Therefore, the movement of the carriage (11) is stopped, and damage to the arm (12) and the small article (A) can be avoided. If the arm board (13) is tilted upward to the right, contrary to the imaginary line in Figure 5, the right microswitch (30)
is OFF, and the left microswitch (30) is OFF.
It remains N.

In this way, by checking the ON and OFF states of one set of detection means, that is, the microswitch (30), it is possible to detect the inclination of the arm board (13), that is, the overload state, and this signal is used to stop the stacker crane. be able to.

(Modification) In the above-described embodiment, a set of microswitches was used as a means for detecting the inclination of the arm during overload, but instead of this, a known device such as a non-contact switch or a pressure sensor may be used. Sensing means may also be used.

In addition, the means for detecting overload of the arm may be placed anywhere, not between the carriage and the arm board, as long as it can practically detect the fork at the tip of the arm or the inclination of the arm. When a load is applied, the arm tilts, and this tilted state is detected by the detection means, so that the operation of the stacker crane can be immediately stopped. Therefore, there is an advantage that damage to storage shelves, small articles, or the stacker crane can be prevented.

Further, since overload on the arm can be detected by simply detecting the amount of rotation of the arm, the configuration of the arm support structure is simple.

[Brief explanation of drawings]

Figure 2 is a side view; Figure 3 is a partially cutaway plan view of Figure 1; Figure 4 is a side view of Figure 3;
FIG. 5, which is a longitudinal sectional view taken along line IV-IV in the figure, is a schematic configuration diagram showing the operation of the arm. (1) Storage (2) Central passage (3) (
4) Storage 111I (5) (6) Rail (7) Stacker crane (9) Column (11) Carriage
(12) Arm (13) Arm board (
15) Moving arm (18) Fork (2
2) Support plate (2:3) bolt (25)
Spacing material (26) Connection bolt (28) Spring seat (z9) Coil spring (30) Micro switch (detection means) Fig. 1

Claims (1)

[Claims] A vertical column that can be moved guided by horizontal rails,
In a stacker crane in which a carriage is mounted so as to be movable up and down, and an arm is provided on the carriage with a fork on which an article can be placed, the arm is held in a horizontal state with a required biasing force when no load is applied, and when the arm is in a horizontal state when no load is applied. The stacker crane is supported by the carriage so that it may be in a slightly inclined state at times, and a detection means is provided to detect the amount of inclination of the arm, thereby making it possible to stop the operation of the stacker crane when the fork is overloaded. Features: Arm support structure in stacker cranes.