JPS5978007A - Detector for elongation in conveyor driving chain - Google Patents

Abstract

PURPOSE:To make the constant indication of elongation in a chain attainable, by installing each detector in reference positions at both inlet and outlet sides of a conveyor, while synchronizing the phase difference between both detecting signals in time of chain elongation, and counting and indicating the number of generated pulses. CONSTITUTION:A hanger 6 attached to a chain 1 is detected by detectors 4 and 5 installed in each reference position in the vicinity of an inlet and an outlet of a conveyance passage. This hanger 6 is installed in position at every 20 chain links at regular intervals, and in time of starting the chain 1 in operation, positions of these detectors 4 and 5 are preset so as to cause them to detect the hanger 6. When the chain 1 increases in length, a detecting signal b5 out of the detector 5 advances farther by phase alpha in proportion to the chain elongation than a singal b4 of the detector 4 so that if a pulse a1 generated in the duration of time t commensurate to the phase alpha is counted and each lamp 9 in a lamp line indicator 8 is lighted as many as the counted value only, the elongation of the chain 1 can be indicated with the number of links.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conveyor drive chain elongation detection device.

Conveyors transport goods by attaching hangers, carriers, etc. to a drive chain that moves on ceilings, floors, etc.
The drive chain gradually elongates with use, and this elongation is an indicator of the service life of the drive chain. Particularly when the chain is several hundred meters long, it is necessary to detect the length of the chain because the length has a large effect on control and processing measures related to the position of the conveyed items.

However, until now, no detection device that can be easily used for such purposes has been found.

The present invention has been made in view of the current situation, and an object of the present invention is to provide a conveyor drive chain extension detection device that can display the extension of a conveyor drive chain at any given time.

In the present invention, an object to be detected that has been removed from the conveyor drive chain with a certain pinch is detected by detectors installed at the reference position on the entrance side and the reference position on the exit side of the conveyor, and the use of the drive chain is started. Sometimes, the reference position is set so that both detectors emit detection signals at the same time, and the phase difference between the rain detection signals when the chain is extended is calculated by calculating the dl number by the number of pulses generated in synchronization with the chain movement. The length of the drive chain is displayed on the display according to the numerical value. As the object to be detected, a hanger, carrier, dog, various axotiment, etc. connected to the drive chain can be used, and as the detector, various contact type or non-contact type limit switches or photoelectric elements can be used.

Therefore, according to the present invention, the extent of deterioration and aging of the chain can be known by reading the length of the drive chain from the display device, thereby making it easier to predict and determine when it is time to replace the chain. This is extremely useful for planning and executing conveyor operation plans.

An embodiment of the present invention will be described below. In FIG. 1, a conveyor drive chain 1 has a driving chain wheel 2 and a driven chain wheel 3.
and move in the direction of the arrow. Reference numerals 4 and 5 denote an entrance side detector and an exit side detector provided at reference positions near the entrance q and exit (zJ) of the conveyance path, respectively, to detect the hanger 6 attached to the chain 1.The hanger 6 is, for example, a chain link 20
The positions of both detectors 4 and 5 are determined so that the detectors 4 and 5 simultaneously detect the hanger 6 when the chain 1 starts to be used. As a pulse generation source, a pulse generator 7 is used which rotates in synchronization with the driving chain wheel 2 and generates a pulse for each link.

FIG. 2 shows the operation chart 1, where a is a pulse signal from the pulse transmitter 7, and b is a detection signal from the detectors 4 and 5 at the beginning of use of the chain 1, which are generated at every pitch p of the hanger 6. When the chain 1 is extended, the detection signal b of the detector 5
5 advances the detection signal b4 of the detector 4 by a phase α proportional to the extension, so the pulses al generated during the time t corresponding to the phase α are counted, and the lamps 9 of the lamp array display device 8 are counted.
By lighting up or counting, the length of the chain can be displayed in terms of the number of links.

When the chain 1 is extended, the phase difference between the detection signal b5 of the detector 5 near the pulse transmitter 7 and the pulse a is almost constant, and the detection signal b4 of the detector 4 has a large phase shift with respect to the pulse a. Since, the number of pulses al is relatively stable for the same extension. However, in a long drive chain,
Since the overall extension is estimated by the extension of the intermediate section, if the detectors 4.5 are provided at the reference positions at both ends of the section, the phase difference between the Mi detection signal b5 and the pulse signal a will vary greatly depending on the extension. Therefore, the number of pulses al can vary for the same length. However, if the length and position of the section are appropriately selected, it is possible to obtain practically sufficient detection accuracy for purposes such as determining when to change the chain and controlling the position of conveyed objects.

FIG. 3 shows a block diagram of the detection circuit. Signals a, b4,
The signal b5 is input to the counter 11 via the waveform shaping circuit 10, and the counter 11 generates a set of pulses a using the signals b5 and b4 as a counter start signal and a count stop signal, respectively.

The counter 11 transmits the count signal to the duder 12 by the signal b4.
It is cleared by the next signal b5. The driver 13 operates the display device 8 according to the output signal of the chain 12.

The present invention is as described above, and has the feature that the length of the conveyor drive chain can be easily determined when it is cold.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic elevational view, FIG. 2 is an operational chart 1-1, and FIG. 3 is a block diagram of a detection circuit. ■... Conveyor drive chain 4... Inlet side detector 5... Outlet side detector 7.
...Pulse transmitter 11...Counter 8...Display device agent Patent attorney Yuyosuke - 1 other person

Claims (1)

[Claims] Detectors attached to the conveyor drive chain at a constant pitch are detected at the same time at the reference position when the chain and the chain begin to be used. side detector;
a pulse generator that generates a pulse every time the chain moves a certain amount that is sufficiently smaller than the pinch; a counter that counts the pulses from the detection point of the outlet side detector to the detection point of the inlet side detector; and a counter counter. A conveyor drive chain elongation detection device having a display device that displays numerical values.