JPS6246446B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a double-row chain conveyor in which a conveyor is straddled between rotary chains provided symmetrically,
In particular, the present invention relates to an abnormality prediction device for a double-row chain conveyor.

Conventionally, a double-row chain conveyor is constructed by suspending an endless chain on chain wheels arranged symmetrically on both walls of a pond such as a settling tank, and a conveyor is placed between the chains. A stress detector is interposed in the supporting part of the conveyor, and a proximity detector facing the rotating orbit of the conveyor is provided to constitute a conveyor abnormality detection device. With this configuration, even if it is difficult to monitor the conveyor due to turbid water, the tension caused by the take-up device and the operating load can be detected by the stress detector, and the rotation period of the conveyor can be detected by the proximity detector. They try to find out what is wrong.

However, with this device, even if there are problems that are common to chain conveyors, such as a decrease in tension due to wear of the chain or poor engagement with the chain wheel, the chain driven by the chain wheel will break or become misaligned. Since the conveyance device is driven with a normal rotation period, it is not possible to predict such accidents in advance and prevent them from occurring.

SUMMARY OF THE INVENTION In view of the above drawbacks, it is an object of the present invention to provide a device that predicts the above-mentioned accident in advance and prevents it by knowing the state of elongation of the chain.

Chains elongate over time due to elongation of the material, abrasion of connecting parts, etc., and if this elongation exceeds a certain value, accidents such as breakage and misalignment may occur. The inventor discovered that the elongation of the chain is proportional to the speed of the chain at that time. That is, with the same conveyor and under the same driving conditions, the chain speed will increase, albeit slightly, as the operation progresses.

Therefore, by installing a pair of proximity detectors in the tensioned part of the chain and detecting the time it takes for a detection piece attached to the chain to pass between the pair of proximity detectors, the passing time will decrease as the chain stretches. . Then, if the passing time corresponding to the limit chain elongation that causes chain cutting or misalignment is compared with a preset reference time, and measures such as stopping the drive device are taken based on the results, the chain can be cut in advance. ,
Misalignment can be predicted.

The configuration of an embodiment of this invention will be described next.

FIG. 1 shows a front view of this embodiment, FIG. 2 shows a direction taken along the line A--A in FIG. 1, FIG. 3 shows a control-related block diagram, and FIG. 4 shows a time chart.

In Figures 1 and 2, main chain wheels 2a, 2b, tension chain wheels 3a, 3b, and submersible chain wheels 4a, 4b are installed symmetrically on both sides of the settling basin 1, and a chain 5
Suspend a and 5b. Between the chains 5a and 5b, conveyors 6 are straddled at approximately equal intervals.

Chains 5a, 5 suspended on main chain wheels 2a, 2b
In consideration of the rotational trajectory of these chains, respective proximity detectors 8a and 8b are provided on the tension side of b.
The proximity detectors 7a, 7b are connected to the chains 5a, 5b at a further distance from the proximity detectors 8a, 8b.
Detection pieces 9a and 9b are attached to the chains 5a and 5b, respectively.

In FIG. 3, the proximity detectors 7a, 7b have timer devices 10a, 10 to which signals should be input.
Connect b. The proximity detectors 8a and 8b are connected in parallel to an electromagnetic switch 11 of the electric circuit for driving power of the main chain wheel via time-limiting devices 10a and 10b, respectively.

Next, the functions of each part will be explained.

Since the reference numeral a side and the reference numeral b side of the above structure are symmetrical, the reference numerals will be omitted for explanation, and FIG. 4 shows a time chart of the operation.

Close the electromagnetic switch 11 in FIGS. 3 and 4,
When the main chain wheel 2 shown in Figs. 1 and 2 is driven to rotate,
Speed Q/ of chain 5 rotated by main chain wheel 2
S is expressed as N×ω/S (where Q is the pitch number of the chain 5, S is the unit time, N is the number of teeth of the main chain wheel 2, and ω is the rotation angle per unit time). When the chain 5 wears out and the pitch length P increases by △P, the radius R of the pitch circle where the chain 5 meshes with the main chain wheel 2 increases by △R, and the size of R + △R becomes the main chain wheel 2. When the radius of the tooth tip circle is exceeded, the main chain wheel 2 and chain 5
become disengaged and no longer engage. Expressing the speed of chain 5 in terms of length per time, (P+△
P) Q/S, but △P has a limit along with the above △R.

The detection piece 9 attached to the chain 5 (each piece 9-1, 9
-2, 9-3...) passes in front of the proximity detector 7 and in front of the proximity detector 8, respectively, a detection signal (7-1, 7-2, 7-3,...) is detected. Send signals (8-1, 8-2, 8-3...). The time from when the proximity detector 7 detects the detection piece 9 to when the proximity detector 8, which is separated by the distance L, detects the detection piece 9, is calculated by dividing the distance L by the speed (P + △P) Q/S. The value becomes smaller as the pitch dimension P+ΔP of the chain 5 increases.

Here, the time limit device 10 has a limit that is shorter than the initial passing time T ₀ of the chain (the time it takes for one detection piece to pass between two proximity detectors), causing the chain to break or misalignment. Set Ts to be slightly larger than or equal to the transit time m corresponding to the chain elongation (confirmed in advance) close to .

The timer 10 starts counting the set time Ts at the same time as the signal from the proximity detector 7 is input. When the signal from the proximity detector 8 is input to the timer 10 after the count of Ts is completed,
The time limit device 10 does not relay the signal to the electromagnetic switch 11 and prevents the electromagnetic switch from operating.
The power circuit therefore remains closed and the chain continues to drive. Then, when the next signal from the proximity detector 7 is input, the above operation is repeated again.

However, if the signal from the proximity detector 8 is input before the time limit device 10 finishes counting Ts, the signal is relayed to the electromagnetic switch 11, the electromagnetic switch is activated, and the power circuit is activated. Open and stop the chain drive.

As explained above, as the chain stretches, the speed of the chain increases, and the time it takes for the detection piece attached to the chain to pass between two fixed proximity detectors is determined by the time it takes for the chain to break or disengage. It is now possible to predict chain breakage and misalignment before they occur by stopping the chain drive when the time limit approaches. .

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of an embodiment of the present application, and FIG. 2 is a cross-sectional view taken along arrow AA in FIG. FIG. 3 is a control block diagram, and FIG. 4 is an operation time chart. 2a, 2b...main chain wheel, 5a, 5b...chain. 7a, 7b, 8a, 8b... Proximity detector, 1
0a, 10b...Time limit device.

Claims (1)

[Scope of Claims] 1. In a double-row chain conveyor in which a conveyor is straddled between rotary chains provided laterally symmetrically, a plurality of detection pieces 9 are provided in each of the left and right chains 5a and 5b.
a, 9b are attached, and proximity detectors 7a, 7b facing the chains 5a, 5b are provided on the chain pulling side of the driving chain wheels 2a, 2b that suspend the chains 5a, 5b, and the proximity detectors 7a, 7b and the driving Chain wheel 2a, 2
Proximity detectors 8a and 8b are provided between the proximity detectors 7a and 7b at a predetermined interval, respectively, and the proximity detectors 8a and 8b are connected to the timer devices 10a and 10a, respectively.
10b is relayed to electrically connect the electromagnetic switch 11, and the detection piece 9a or 9b is connected to the proximity detector 7a, 8.
a or the time to pass between 7a and 8b, To is the time when the chain was first installed, Tm is the limit close to the abnormal state that you want to predict, and the setting time of the timer.
An abnormality prediction device for a chain conveyor, characterized in that when Ts, To>Ts≧Tm, and an electromagnetic switch is opened when Ts becomes Tm.