JPS6356123B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a count control method for a longitudinally moving body.

For example, in a rotating rack equipped with a large number of trays that are connected endlessly and move in any direction in the forward or reverse direction on a circulation path, the rack passes through the load handling position in order to control a specific tray to be called to the load handling position. The tray number of the tray is detected by a counting method. In other words, a tray passing through a specific position,
An addition/subtraction counter is used that adds up when the tray moves forward and subtracts when it moves backward, and compares the count value of this counter with the set calling tray number as the tray number of the tray passing through the cargo handling position. Tray call control is being performed to

In the conventional method, the addition/subtraction switching of the addition/subtraction counter was performed in synchronization with the switching of the rotational direction of the motor that drives the tray, so the counter could be changed by chattering when stopped or by manual inching operation. A malfunction had occurred.

The present invention aims to provide a count control method capable of solving the above-mentioned problems, and one embodiment thereof will be described below with reference to the attached illustrative drawings.

In FIG. 1, 1 is an endless drive chain suspended between a drive gear 2 and an idling gear 3; 4 is a tray attached to the endless chain 1 at regular intervals; 5;
is a tray drive motor which is interlocked with the drive gear 2 through a chain transmission means 6. Second
As shown in the figure and FIG. 3, each tray 4 is equipped with a detection plate 7, and is comprised of a support guide roller 8, a support guide rail 9, a steady rest guide roller 10, and a steady rest guide rail 11. Then,
It is supported so that it can circulate in a fixed position on a horizontal circulation path. PHS-F and PHS-R are a pair of photoelectric switches for detecting the plate 7 to be detected, and are attached at a detection point beside the tray movement path at intervals such that both the front and rear ends of the plate 7 to be detected can be detected simultaneously.

Incidentally, among the series of trays 4, the origin tray 4a which is tray No. 1 is attached with an origin detection plate 7a, and an origin detection photoelectric switch PHS- detects only this origin detection plate 7a. X is arranged between the pair of photoelectric switches PHS-F and PHS-R.

In FIG. 4, 12 is a means for detecting the tray number of the tray passing through the cargo handling position (home position), and the photoelectric switch PHS-F, PHS
Using the detection signal from -R, an addition/subtraction counter function that adds up during normal rotation and subtracts during reverse rotation outputs a unique tray number for each tray passing through the cargo handling position. In addition, the photoelectric switch PHS-
The X detection signal uses the counter value as the origin (No. 1)
used to restore. Reference numeral 13 is a comparison rotation, in which the calling tray number input and the detection tray number input from the tray number detection means 12 are input.
When the next tray in the tray movement direction passes the called tray, deceleration command A is output, and a match occurs when the called tray number and the detected tray number match. Outputs signal C.

14 is an OR gate element, 15 is an AND gate element, and by the functions of both gate elements,
When a detection signal from either of the photoelectric switches PHS-F and PHS-R is output while the deceleration command A is being output, a stop command B is output.
Reference numeral 16 denotes a stop position check circuit, which outputs a coincidence signal C after a certain period of time (a time set slightly longer than the expected time required for stopping) after the stop command B is output and checks both the photoelectric switches. If a detection signal is output from either PHS-F or PHS-R, a stop completion signal D is used as a start signal for the automatic load transfer device at the load handling position.
is output, and if not, a stop position correction command E is output for inching the drive device 17 including the tray drive motor 5 so that it is in the stopped state.

Next, the counting control method of the present invention in the tray number detecting means 12 will be explained. This counting control is based on program control using a computer, and is programmed as shown in the flowchart of FIG. It is processed.

For this count control, the photoelectric switch
In addition to the detection signals of PHS-F, PHS-R, and PHS-X, memory flags such as FE, FM, RE,
Four RMs are used. As shown in Figure 6,
Flags FE and RE are photoelectric switches PHS-F and
The flags FM and RM correspond to the rising edge of the PHS-R detection signal, and the flags FM and RM correspond to the falling edge of the signal.

As the tray 4 moves, each photoelectric switch PHS-F, PHS-R, and PHS-X outputs a detection signal at the timing shown in FIG. At this time, if tray 4 is moving forward, the photoelectric switch is turned on in the order of PHS-F → PHS-R (detection state).
When moving backwards, the order is reversed. As shown in FIG. 5, the memory flag FE is set at the rising edge of the detection signal of the photoelectric switch PHS-F, and the memory flag FE is set at the rising edge of the detection signal of the photoelectric switch PHS-F.
It is reset at the falling edge of the detection signal. The memory flag RE is set at the rising edge of the detection signal of the photoelectric switch PHS-R, and each photoelectric switch
It is reset when the detection signal of PHS-F and PHS-R falls. Furthermore, the memory flag FM is set when the detection signal of the photoelectric switch PHS-F falls and the photoelectric switch PHS-R is OFF (non-detection state), and when the detection signal of the photoelectric switch PHS-R falls and the photoelectric switch PHS-F
Reset when turned OFF. Memory flag RM
is set when the detection signal of the photoelectric switch PHS-R falls and the photoelectric switch PHS-F is OFF (non-detection state), and the photoelectric switch PHS-F
The detection signal falls and the photoelectric switch PHS
-Reset when R is OFF.

As is clear from the operating conditions of this memory flag, the state of the memory flag FM → ON and RM → OFF means that it is remembered that the immediately previous detected tray 4 passed the detection point in the backward direction. The state of the memory flag FM→OFF and RM→ON means that it is remembered that the immediately previous detected tray 4 passed the detection point in the forward direction. In Figure 5, CNT shows the ring counter function,
(CNT←CNT-1) means a subtraction count process, and (CNT←CNT+1) means an addition count process. Also, (CNT←1) means the process of returning the counter count value to the origin 1.

Figure 7 shows photoelectric switches PHS-F and PHS-R.
It specifically shows the relationship between the operating status of each memory flag FE, FM, RE, and RM and the counted value of the counter. In this Figure 7, Examples 1 to 9 are No. 8.
The operation is shown when each tray 4 of No. 10 is moving in the forward direction, and in Examples 9 to 17, each tray 4 of No. 10 and No. 9 that has passed the detection point is moving back in the backward direction. In this figure, each memory flag FE to RM operates under the above-mentioned operating conditions. As is clear here, the memory flags FM→OFF and RM→ON in Examples 1 to 12 indicate that the immediately preceding detected tray (in FIG. 7, trays No. 8 to 10 shown in Examples 1 to 9) This indicates that the detection point has been moved in the forward direction, and the memory flag FM in Examples 13 to 17 →
ON, RM→OFF indicates that the immediately preceding detected tray (trays No. 10 and 9 shown in Examples 9 to 17 in FIG. 7) has moved the detection point in the backward direction.

Therefore, as is clear from the description in Figure 7,
Only when the tray 4 to be detected moving through the detection point is moving in the same direction as the moving direction of the tray 4 that passed this detection point immediately before when it passed the detection point,
When the photoelectric switches PHS-F and PHS-R detect both the front and rear ends of the detection plate 7 of the detection tray 4, the counter CNT advances with an addition count when moving forward and a subtraction count when moving backward. It turns out. and examples 9 to 13
As shown in FIG. 7, when the tray 4 immediately after passing the detection point turns back in the opposite direction and moves to the detection point again, the detection plate 7 of the tray (Tray No. 10 in FIG. 7) is exposed to both photoelectric switches. The counter CNT does not operate even when detected by PHS-F and PHS-R, and the counted value is the number of tray 4 that just passed the detection point in the opposite direction (therefore, the current
The number of the tray 4 which is passing through the detection point or has passed the detection point is displayed.

The detected plate 7a of the origin tray 4a is detected by the origin detection photoelectric switch PHS-X, and both ends of the detected plate 7a are detected by the photoelectric switch PHS-X.
It is easy to understand from the flowchart in Fig. 5 that when the origin tray 4a is detected by the F, PHS-R, that is, when the origin tray 4a reaches the detection point, the count value of the counter CNT is returned to the origin 1. It will be.

According to the count control method of the present invention as in the above embodiment, a large number of movable bodies (tray 4 in the embodiment) are connected in a daisy chain and move back and forth on a fixed path.
A detected part (detected plate 7 in the embodiment) is provided at each of the fixed side detection points, and a pair of detection switches (in the embodiment) are installed at the fixed side detection point at intervals that allow simultaneous detection of both the front and rear ends of the detected part when the moving object passes. Example photoelectric switch
PHS-F, PHS-R) is installed to determine and memorize whether the moving object that recently passed the detection point passed in the forward direction or in the backward direction, based on the detection operation history of the pair of detection switches. , in a state where the moving object currently moving through the detection point is moving in the same direction as the memorized passing direction, only when the pair of detection switches both detect the detected part of the moving object, the moving object moves forward. Since the feature is that the count is performed under the condition that the count is added when passing in a direction and subtracted when passing in reverse, there is no need for any information regarding the rotational direction of the motor that drives the moving body forward and backward, and movement to move the detection point is possible. It is possible to judge whether or not a body should be counted based on the passing direction of the moving body that just passed this detection point, and to count only when it is a moving body that should be counted, so it can eliminate chattering when stopped. Even when inching manually or when moving the moving object manually with the drive motor free, in other words, no matter how the moving object moves at the detection point, it will be accurate without malfunction. This makes it possible to reliably detect the number of a moving object that is actually passing through the detection point.

In the above embodiment, the tray number detected by the tray number detection means 12, that is, the counter CNT
The tray number obtained as the count value is used as follows.

That is, in order to call the tray 4 with the selected specific number to the load handling position, when the drive device 17 is operated with the call tray number set and the series of trays 4 are circulated by the motor 5, they pass through the load handling position. The numbers of the trays 4 are sequentially outputted from the detection means 12 as described above, and the detected tray numbers and the called tray numbers are compared in the comparator circuit 13.
When the tray 4 in front passes the load handling position, a deceleration command A is output, and the drive device 17 receives this deceleration command and automatically reduces the rotational speed of the motor 5 to a predetermined low speed. After the series of trays 4 are moved at low speed in this way,
Photoelectric switch PHS-F (when the tray moves forward) or PHS-R located at the front in the direction of tray movement
(during backward movement of the tray) detects the detected plate 7 of the tray 4, a stop command B is output, and the drive device 1
7 receives the stop command B, stops driving the tray by the motor 5, and switches the motor 5 to a dynamic braking state. Therefore, the series of trays 4 will move a certain distance due to inertia and then stop. As a result, the calling tray 4 is placed at the cargo handling position by connecting both ends of the detection plate 7 with a pair of photoelectric switches PHS-F,
This means that the PHS-R has stopped accurately within the range of ±10 mm, for example.

Although the embodiment shown in FIG. 4 uses individual control means or circuits, it is actually possible to use a computer in conjunction with the program control method.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view illustrating the configuration of the rotary rack, Fig. 2 is a plan view showing the relationship between the tray and the detection switch, Fig. 3 is a side view of the same, and Fig. 4 is a block diagram illustrating the entire control device. 5 is a flowchart showing an embodiment of the present invention, FIG. 6 is an operation timing chart of each photoelectric switch, and FIG. 7 is a diagram showing the movement status of the detected plate at the detection point, the photoelectric switch, and the memory flag. FIG. DESCRIPTION OF SYMBOLS 1...Endless chain, 2...Drive gear, 3...Idle gear, 4...Tray, 5...Tray drive motor, 7, 7a...Detected plate (detected part), 12
... Tray No. detection means, 13 ... Comparison circuit, 16
... Stop position check circuit, 17 ... Tray drive device, PHS-F, PHS-R, PHS-X ... Photoelectric switch (detection switch), A ... Deceleration command, B
...Stop command.

Claims (1)

[Claims] 1 A detected part is provided for each of a large number of movable bodies that are connected in a daisy chain and move back and forth on a fixed path, and at a fixed side detection point, both front and rear ends of the detected part are simultaneously detected when the movable body passes. A pair of detection switches are arranged at intervals of 1 to 100 mm, and based on the detection operation history of the pair of detection switches, it is stored whether the moving object that recently passed the detection point passed in the forward direction or in the reverse direction, and the current , only when the pair of detection switches both detect the detected portion of the moving object while the moving object moving through the detection point is moving in the same direction as the memorized passing direction, the moving object passes in the forward direction. A counting control method for a forward-reverse moving body, characterized in that the count is added at times and subtracted when passing in reverse.