阅读说明：本技术 链条监视系统 (Chain monitoring system ) 是由 冈崎吉洋 柴山智成 关野祐司 于 2019-07-29 设计创作，主要内容包括：本发明提供一种链条监视系统,设置空间较小,不会增大制造成本和维护成本,能够检测中央链节和侧链节的局部断裂。设置在环状链条(1)的循环路径的规定部位的链条异常检测装置(10)具备测定开始位置检测单元(21)、基准位置检测单元(22)以及距离测定单元(23)。测定开始位置检测装置(21)检测测定开始位置(20)来到了第一规定位置(P1)的情况,基准位置检测装置(22)检测基准位置(RP)来到了第二规定位置(P2)的定时。距离测定部件(23)按照所述定时来测定从基准位置(RP)到后续的基准位置(RP)的距离(D)。具备：在同一基准位置(RP)计算本次测定出的距离(D)与上次测定出的距离(D)的差分；以及断裂判定单元,基于由所述差分计算单元计算出的差分来判定有无局部断裂。(The invention provides a chain monitoring system which has a small installation space, does not increase the manufacturing cost and the maintenance cost, and can detect the local fracture of a central chain link and a side chain link. A chain abnormality detection device (10) provided at a predetermined position of a circulation path of an endless chain (1) is provided with a measurement start position detection means (21), a reference position detection means (22), and a distance measurement means (23). A measurement start position detection device (21) detects when the measurement start position (20) has reached the first predetermined position (P1), and a reference position detection device (22) detects when the Reference Position (RP) has reached the second predetermined position (P2). A distance measuring unit (23) measures the distance (D) from the Reference Position (RP) to the subsequent Reference Position (RP) in accordance with the timing. The disclosed device is provided with: calculating the difference between the distance (D) measured this time and the distance (D) measured last time at the same Reference Position (RP); and a fracture determination unit that determines whether or not there is a local fracture based on the difference calculated by the difference calculation unit.)

1. A chain monitoring system for monitoring the state of an endless chain by a chain abnormality detection device provided at a predetermined position of a predetermined circulation path in a chain facility including the endless chain formed by connecting a plurality of links and a drive device therefor, in a state where the endless chain is circulated along the predetermined circulation path,

the chain abnormality detection device is provided with a measurement start position detection means, a reference position detection means, and a distance measurement means,

the measurement start position detection means detects that the measurement start position of the endless chain has reached a first predetermined position,

the reference position detecting means detects that the measurement reference position of the endless chain has reached a second predetermined position,

the distance measuring means measures a distance from the measurement reference position to a subsequent measurement reference position each time the reference position detecting means detects that the measurement reference position has reached the second predetermined position,

the chain monitoring system includes:

a storage unit that stores the distance measured by the distance measuring unit in accordance with the measurement reference position;

a difference calculation unit that calculates a difference between the distance measured this time and the distance measured the previous time and/or the previous time at the same measurement reference position; and

and a breakage determination unit configured to determine whether or not the endless chain has a partial breakage based on the difference calculated by the difference calculation unit.

2. A chain monitoring system for monitoring the state of an endless chain by a chain abnormality detection device provided at a predetermined position of a predetermined circulation path in a chain facility including the endless chain formed by connecting a plurality of links and a drive device therefor, in a state where the endless chain is circulated along the predetermined circulation path,

the chain abnormality detection device is provided with a measurement start position detection means, a reference position detection means, and a distance measurement means,

the measurement start position detection means detects that the measurement start position of the endless chain has reached a first predetermined position,

the reference position detecting means detects that the measurement reference position of the endless chain has reached a second predetermined position,

the distance measuring means measures a distance from the measurement reference position to a subsequent measurement reference position each time the reference position detecting means detects that the measurement reference position has reached the second predetermined position,

the chain monitoring system includes:

a storage unit that stores the distance measured by the distance measuring unit in accordance with the measurement reference position, and stores an initial distance that is the distance when the endless chain first circulates in the chain facility; and

and a breakage determination unit configured to determine whether or not the endless chain has partially broken at the same measurement reference position based on the distance measured this time and the initial distance.

3. The chain monitoring system as recited in claim 1 or 2,

the chain abnormality detection device is provided on the endless chain upstream of and near a tension-maximizing portion where the tension applied to the endless chain is maximized.

4. The chain monitoring system as set forth in claim 3,

the chain abnormality detection device is provided on the endless chain upstream of a driven portion of the endless chain driven by the drive device and in the vicinity of the driven portion.

5. The chain monitoring system as set forth in any one of claims 1 to 4,

the endless chain includes:

a center link formed of an elongated annular member or a rod-like member having pin holes penetrating in the vertical direction at front and rear end portions;

a pair of upper and lower links each formed of a plate-like member having a pin hole penetrating in a vertical direction at front and rear end portions thereof; and

a connecting pin connecting the center link and the pair of upper and lower side links,

the reference position is a front end portion of the center link.

6. The chain monitoring system as set forth in claim 1,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

7. The chain monitoring system as set forth in claim 3,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

8. The chain monitoring system as set forth in claim 4,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

9. The chain monitoring system as set forth in claim 5,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

10. The chain monitoring system as set forth in claim 1,

the chain device further includes an automatic oil supply unit that supplies oil to the endless chain when the rate of change of the difference calculated by the difference calculation unit becomes a predetermined value or more.

Technical Field

The present invention relates to a chain monitoring system for monitoring a state of an endless chain by a chain abnormality detection device provided at a predetermined position of a predetermined circulation path in a chain facility including the endless chain connecting a plurality of links and a drive device thereof, in a state where the endless chain circulates along the predetermined circulation path.

Background

As a chain monitoring system for detecting breakage of an endless chain, there is a system in which: the stop of the chain when the chain of the sludge scraper is completely broken due to corrosion, abrasion, external force, or the like is detected, an alarm is issued, and the drive motor is stopped (for example, see patent document 1).

As a chain monitoring system that detects an abnormal state causing a complete breakage before the endless chain is completely broken, there is a system in which: in a conveyor chain in which a center link and a side link pin are coupled to each other for use in a coating line of an automobile or the like, complete breakage of the chain is prevented by directly detecting breakage (partial breakage) of one side (one connecting portion) of the center link due to fatigue (see, for example, patent document 2).

Patent document 1: japanese Kokoku publication Sho 57-20320

Patent document 2: japanese examined patent publication (Kokoku) No. 07-52096

The chain monitoring system (the conveyor chain breakage detection device 1) of patent document 2 includes one of right and left detection portions 3 and 4 disposed so as to face the side portion of the chain 2 at an interval in the moving direction of the conveyor chain 2.

Each of the detection units 3 and 4 has a permanent magnet 5, and an induction coil 8 is wound around one of the iron materials 6 and 7 attached to both poles of the magnet 5.

A nonconductive member 9 is provided to cover the tip ends of the two iron materials 6 and 7, and the magnet 5 and the nonconductive member 9 are fixed to a movable base 10.

The movable stand 10 is disposed on the fixed stand 11 and is guided by the guide rail 12, and therefore can move in a direction perpendicular to the chain 2.

Since the movable stand 10 is biased toward the chain 2 by the coil spring 13 and the opposite-chain hydraulic shock absorber 14 is activated, the chain 2 is always in close contact with the non-conductive member 9 and the distance from the detection portions 3 and 4 is substantially constant.

A projector is disposed on one side and a pair of right and left photoelectric cells 15 as light receivers are disposed on the other side with respect to the chain 2, and the photoelectric cells 15 detect the inspection timing and reset the counter.

When the chain 2 moves, the central link 21 and the side links 22 of the chain 2 alternately pass through a magnetic field to cause a change in magnetic flux, and thus induced electromotive force is detected by the detection portions 3 and 4. The induced electromotive force thus detected is an amount that is generated once more when one of the connecting portions of center link 21 breaks, and therefore, it is possible to directly detect that one side (one of the connecting portions) of center link 21 is broken (partially broken).

However, in the chain monitoring system as in patent document 2, since the two detection sections 3 and 4 provided on both sides of the conveyor chain 2 are large-scale structures each including the permanent magnet 5, the iron materials 6 and 7, the induction coil 8, the non-conductive member 9, the movable table 10, the fixed table 11, the guide rail 12, the coil spring 13, the hydraulic shock absorber 14, and the like, a large installation space is required on both the left and right sides of the chain 2, and the manufacturing cost increases.

Further, since the non-conductive members 9 of the detection units 3 and 4 need to be brought into close contact with the moving chain 2, abrasion or the like occurs in the non-conductive members 9, and thus maintenance cost is increased.

Further, although a local breakage of the center link 21 of the chain 2 can be detected, a breakage of one of the upper and lower pair of side links 22, 22 cannot be detected.

Disclosure of Invention

In view of the above circumstances, an object of the present invention is to provide a chain monitoring system that has a small installation space, does not increase the manufacturing cost and the maintenance cost, and can detect a breakage of one of the pair of upper and lower side links in addition to a partial breakage of the center link.

The gist of the present invention is as follows.

[1] A chain monitoring system for monitoring the state of an endless chain by a chain abnormality detection device provided at a predetermined position of a predetermined circulation path in a chain facility including the endless chain formed by connecting a plurality of links and a drive device therefor, in a state where the endless chain is circulated along the predetermined circulation path,

the chain abnormality detection device is provided with a measurement start position detection means, a reference position detection means, and a distance measurement means,

the measurement start position detection means detects that the measurement start position of the endless chain has reached a first predetermined position,

the reference position detecting means detects that the measurement reference position of the endless chain has reached a second predetermined position,

the distance measuring means measures a distance from the measurement reference position to a subsequent measurement reference position each time the reference position detecting means detects that the measurement reference position has reached the second predetermined position,

the chain monitoring system includes:

a storage unit that stores the distance measured by the distance measuring unit in accordance with the measurement reference position;

a difference calculation unit that calculates a difference between the distance measured this time and the distance measured the previous time and/or the previous time at the same measurement reference position; and

and a breakage determination unit configured to determine whether or not the endless chain has a partial breakage based on the difference calculated by the difference calculation unit.

[2] A chain monitoring system for monitoring the state of an endless chain by a chain abnormality detection device provided at a predetermined position of a predetermined circulation path in a chain facility including the endless chain formed by connecting a plurality of links and a drive device therefor, in a state where the endless chain is circulated along the predetermined circulation path,

the chain abnormality detection device is provided with a measurement start position detection means, a reference position detection means, and a distance measurement means,

the measurement start position detection means detects that the measurement start position of the endless chain has reached a first predetermined position,

the reference position detecting means detects that the measurement reference position of the endless chain has reached a second predetermined position,

the distance measuring means measures a distance from the measurement reference position to a subsequent measurement reference position each time the reference position detecting means detects that the measurement reference position has reached the second predetermined position,

the chain monitoring system includes:

a storage unit that stores the distance measured by the distance measuring unit in accordance with the measurement reference position, and stores an initial distance that is the distance when the endless chain first circulates in the chain facility; and

and a breakage determination unit configured to determine whether or not the endless chain has partially broken at the same measurement reference position based on the distance measured this time and the initial distance.

[3] The chain monitoring system according to [1] or [2], wherein,

the chain abnormality detection device is provided on the endless chain upstream of and near a tension-maximizing portion where the tension applied to the endless chain is maximized.

[4] The chain monitoring system according to [3], wherein,

the chain abnormality detection device is provided on the endless chain upstream of a driven portion of the endless chain driven by the drive device and in the vicinity of the driven portion.

[5] The chain monitoring system according to any one of the above [1] to [4], wherein,

the endless chain includes:

a center link formed of an elongated annular member or a rod-like member having pin holes penetrating in the vertical direction at front and rear end portions;

a pair of upper and lower links each formed of a plate-like member having a pin hole penetrating in a vertical direction at front and rear end portions thereof; and

a connecting pin connecting the center link and the pair of upper and lower side links,

the reference position is a front end portion of the center link.

[6] The chain monitoring system according to item [1], wherein,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

[7] The chain monitoring system according to [3], wherein,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

[8] The chain monitoring system according to [4], wherein,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

[9] The chain monitoring system according to [5], wherein,

the breakage determination means determines whether or not the endless chain has partially broken, based on the rate of change of the difference calculated by the difference calculation means.

[10] The chain monitoring system according to item [1], wherein,

the chain device further includes an automatic oil supply unit that supplies oil to the endless chain when the rate of change of the difference calculated by the difference calculation unit becomes a predetermined value or more.

ADVANTAGEOUS EFFECTS OF INVENTION

As described above, the chain monitoring system according to the present invention mainly has the following operational effects.

(1) A chain abnormality detection device provided at a predetermined position of a circulation path of an endless chain in a chain facility can be configured compactly and simply, and an installation space of a chain monitoring system can be reduced and an increase in manufacturing cost can be suppressed.

(2) By configuring the sensor of the chain abnormality detection device to be a non-contact sensor that does not contact the endless chain, it is possible to suppress an increase in maintenance cost.

(3) The chain abnormality detection device includes a measurement start position detection means, a reference position detection means, and a distance measurement means, and is capable of detecting a partial fracture of a center link and a partial fracture of a pair of side links by sequentially measuring the link lengths of the endless chain in accordance with the link numbers by these means and determining whether or not the endless chain is partially fractured by the fracture determination means.

(4) By providing the chain abnormality detection device upstream of and in the vicinity of a tension maximum portion where the tension acting on the endless chain becomes maximum in the endless chain, the elongation of the link length due to wear and the elongation of the link length due to partial breakage can be clearly distinguished, and the partial breakage of the endless chain can be reliably detected.

Drawings

Fig. 1 is a schematic plan view showing a chain monitoring system according to an embodiment of the present invention.

Fig. 2 is an exploded perspective view of the endless chain.

Fig. 3 is a perspective view of the chain abnormality detection device.

Fig. 4 is a partial longitudinal sectional view of the chain abnormality detection device as viewed from the front.

Fig. 5 is a front perspective view showing a sensor of the chain abnormality detecting device.

Fig. 6 is a front view of the chain abnormality detecting device.

Fig. 7 is a plan view showing a partially broken center link taken out.

Fig. 8 is a graph showing the relationship between the link number and the difference in link length.

Description of the symbols

1 Ring chain

2 drive device

3 drive sprocket

4 steering wheel

5 steering roll

6 tensioner

7 sliding vehicle

8 running roller

9 guide rail

10 chain abnormality detection device

10A transceiver

10B control part

10C memory cell

11 center link

11A pinhole

12 side chain segment

12A pin hole

13 connecting pin

20 reflecting plate

21 reflection type photoelectric sensor (measurement start position detection unit)

22 transmission type photoelectric sensor (reference position detecting unit)

22A projector

22B light receiver

23 laser CCD Length measuring sensor (distance measuring unit)

23A projector

23B light receiver

24 support member

25 sensor controller

A chain equipment

B driven part

C circulation path

Initial link length of D0

D distance (chain link length) from measurement reference position to subsequent measurement reference position

E magnetic yoke

Local fracture of F

L1, L2, L3 light

P1 first prescribed position

P2 second prescribed position

RP measurement reference position

Width of measurement of W

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

In the following embodiments, the left and right sides are defined with the traveling direction of the endless chain set to front and the opposite direction set to back and directed forward, and the left side is taken as a front view.

< chain device >

In a chain apparatus a shown in a schematic plan view in fig. 1, an endless chain 1 is stretched over a drive sprocket 3, diverting pulleys 4, … …, and diverting rollers 5, … … of a drive device 2, and tension is applied by a tensioner 6. The endless chain 1 circulates on a predetermined circulation path C while traveling in the direction of the arrow in the figure.

The chain apparatus a includes a chain monitoring system for monitoring the state of the endless chain 1 by the chain abnormality detection device 10.

The chain facility a of the present invention is preferably a conveyor line of an automobile, for example, and the endless chain 1 is preferably a conveyor chain used for a conveyor line of an automobile, and more preferably a rivetless chain.

In the chain apparatus a, the endless chain 1 is repeatedly bent in a state where tension is applied, and stress is repeatedly applied to the endless chain 1. Therefore, a local fracture of one side of the center link or a fracture of one of the pair of upper and lower links occurs due to fatigue. Even when such a break occurs, the chain apparatus a can be operated without any problem for a certain period of time.

In the present application, "partial breakage" of one side of the center link of the endless chain 1 and "breakage" of one of the upper and lower pairs of side links of the endless chain 1, that is, "partial breakage" of the upper and lower pairs of side links, are included, and are referred to as "partial breakage" of the endless chain 1.

The chain monitoring system detects a partial breakage of the endless chain 1 before the endless chain 1 is completely broken and the chain apparatus a becomes inoperable, and thereby, the partially broken center link or side link can be replaced. This prevents the endless chain 1 from being completely broken and the chain device a from becoming inoperable.

For example, the partially broken link is replaced while the partially broken link is moved to a position where the tension acting on the endless chain 1 is minimum and the endless chain 1 is stopped.

< chain monitoring System >

In the chain monitoring system according to the embodiment of the present invention, in the chain equipment a, the state of the endless chain 1 is monitored by the chain abnormality detection device 10 provided at a predetermined position of the circulation path C in a state where the endless chain 1 circulates along the circulation path C.

The chain abnormality detection device 10 detects the length of each link as described later, and determines a local breakage based on a change in the length due to the local breakage, and is therefore provided at a location where the tension acting on the endless chain 1 is estimated to be equal to or greater than a predetermined value. This is to clearly distinguish between elongation of the link length due to wear and elongation of the link length due to local breakage.

Therefore, the chain abnormality detection device 10 is preferably provided in the endless chain 1 on the upstream side of and in the vicinity of the tension maximizing portion where the tension applied to the endless chain 1 is maximized.

The tension acting on the endless chain 1 for clearly distinguishing the elongation of the link length due to wear from the elongation of the link length due to partial breakage is appropriately determined depending on the type, material, and the like of the endless chain.

For example, in the case where the chain equipment a of the present invention is an automobile conveyor line, if the tension acting on the endless chain 1 is 2000N or more as a place where the chain abnormality detection device 10 is installed, the elongation of the link length due to wear and the elongation of the link length due to local breakage can be clearly distinguished, and if the tension is 5000N or more, the elongation of the link length due to wear and the elongation of the link length due to local breakage can be more clearly distinguished.

As shown in fig. 1 in particular, a more preferred embodiment of the chain abnormality detection device 10 is arranged in the vicinity of the driven portion B on the upstream side of the driven portion B of the endless chain 1 driven by the drive device 2 in the endless chain 1. Therefore, since the chain abnormality detection device 10 is located near the drive device 2 to be inspected, the chain abnormality detection device 10 can be effectively inspected and the like.

(Ring chain)

As shown in the exploded perspective view of fig. 2, the endless chain 1 is composed of, for example, a center link 11, upper and lower pairs of side links 12, and connecting pins 13, 13.

The center link 11 is formed of an elongated annular member having pin holes 11A penetrating in the vertical direction at the front and rear ends. The center link 11 may be a rod-shaped member having pin holes 11A penetrating in the vertical direction at the front and rear ends.

The side links 12 are formed of plate-like members having pin holes 12A penetrating in the vertical direction at the front and rear ends.

The connecting pin 13 is inserted through the pin hole 12A of one side link 12, the pin hole 11A of the center link 11, and the pin hole 12A of the other side link 12, and is turned by 90 °, thereby connecting the center link 11 to the pair of upper and lower side links 12, 12.

As shown in the perspective view of fig. 3 and the front view of fig. 6, pulleys 7, … … are attached to the endless chain 1, the left and right running rollers 8, 8 of the pulley 7 are supported by the guide rails 9, and the guide rails 9, 9 are supported by the yoke E (see fig. 4).

As shown in the perspective view of fig. 3 and the partial longitudinal sectional view of fig. 4, the guide rails 9 and 9 are a pair of left and right channel steels having a substantially コ -shaped cross section, with openings facing each other at a distance in the left-right direction, but the traveling rollers may be engaged on the left and right sides thereof as one guide rail formed of I-shaped steel.

(constitution of chain abnormality detecting device)

As shown in the perspective view of fig. 3, the partial longitudinal sectional view of fig. 4, and the front view of fig. 6, the chain abnormality detecting device 10 is supported by a support member 24, and includes a sensor controller 25 such as a reflection type photosensor 21 as measurement start position detecting means, a transmission type photosensor 22 as reference position detecting means, a laser type CCD length measuring sensor 23 as distance measuring means, and an amplifier including these sensors.

The chain abnormality detection device 10 includes a transmission/reception unit 10A, a control unit 10B, and a storage unit 10C.

The reflection type photoelectric sensor 21 detects a detection object by projecting light L1 (see fig. 5) to the detection object and receiving reflected light.

The transmissive photosensor 22 includes a projector 22A and a light receiver 22B that are disposed to face each other, and projects light L2 (see fig. 5) from the projector 22A to the light receiver 22B, and detects interruption of the light L2 by an object passing between the projector 22A and the light receiver 22B.

The laser type CCD length measuring sensor 23 includes a light projector 23A and a light receiver 23B, projects light L3 (see fig. 5) having a measurement width W from the light projector 23A to the light receiver 23B, and detects, at a predetermined timing, a position in a traveling direction of an object passing between the light projector 23A and the light receiver 23B when the object blocks the light L3.

As shown in the front perspective view of fig. 5 and the front view of fig. 6, the reflective photosensor 21 as the measurement start position detection means is disposed at the first predetermined position P1, and the transmissive photosensor 22 as the reference position detection means is disposed at the second predetermined position P2 on the downstream side of the first predetermined position P1.

The laser CCD length measuring sensor 23 as the distance measuring means is disposed such that the center of the measurement width W is located upstream of the second predetermined position P2 by, for example: the initial link length (the distance from the measurement reference position RP of the center link 11 to the measurement reference position RP of the subsequent center link 11) D0 (see fig. 6) when the endless chain 1 is first set in the chain apparatus a.

The laser CCD length measuring sensor 23 is disposed at a predetermined distance D0 from the second predetermined position P2, and is positioned in advance by a reference plate or the like that determines the distance.

(operation of chain abnormality detector: measurement of chain Link Length)

A reflection plate 20 for determining a measurement start position is attached to the endless chain 1. Light L1 is projected from the reflection type photosensor 21 as measurement start position detection means, and the link number of the center link 11 when the reflection plate 20 is detected upon receiving the reflection light from the reflection plate 20 is set to 1.

Light L2 is projected from the transmission type photosensor 22 as reference position detecting means, and the timing at which the detected light L2 is blocked by the measurement reference position RP, which is the tip end portion of the center link 11, is triggered by the laser type CCD length measuring sensor 23, which is distance measuring means.

As shown in fig. 5, at the above-described timing, the laser CCD length measuring sensor 23 detects the position of the measurement reference position RP of the subsequent center link 11 when the measurement reference position RP of the distal end portion of the subsequent center link 11 blocks the light L3, and thereby the distance D from the measurement reference position RP to the subsequent measurement reference position RP, that is, the link length, can be sequentially measured for each of the link numbers 1, 2, 3, and … ….

When the reflection plate 19 of the endless chain 1 is detected by the reflection type photoelectric sensor 21, the measurement of the link lengths of all the links of the endless chain 1 is completed, and thus the measurement is completed.

The link lengths measured for each of the link numbers 1, 2, 3, and … … are stored in the storage unit 10C.

(operation of chain abnormality detecting device: first breakage judging method)

The control unit 10B of the chain abnormality detection device or the control unit of the server device that receives the link length transmitted from the transmission/reception unit 10A includes a difference calculation unit and a breakage determination unit.

The difference calculation unit calculates the difference between the link length measured this time and the link length measured the previous time and/or before at the same measurement reference position RP.

The breakage determination means determines whether or not the endless chain 1 is partially broken, based on the difference calculated by the difference calculation means.

Here, the breakage determination means may determine whether or not the endless chain 1 is partially broken, based on the rate of change of the difference calculated by the difference calculation means.

(operation of chain abnormality detecting device: second breakage judging method)

The storage unit 10C also stores an initial link length D0 when the endless chain 1 is initially circulated in the chain apparatus a.

The control unit 10B of the chain abnormality detection device 10 or the control unit of the server device that receives the link length transmitted from the transmission/reception unit 10A includes a breakage determination unit.

The breakage determination means determines whether or not the endless chain 1 has partially broken, based on the link length D measured this time at the same measurement reference position RP and the initial link length D0. For example, the breakage determination means determines whether or not the endless chain 1 is partially broken, based on whether or not the ratio of the link length D measured this time at the same measurement reference position RP to the initial link length D0 exceeds a predetermined value.

Further, the difference calculating means may calculate the difference between the link length D measured this time and the link length measured the previous time at the same measurement reference position RP, and the breakage determining means may determine whether or not the endless chain 1 has been partially broken based on the difference calculated by the difference calculating means and the initial link length D0. This can reduce the amount of information on the link length to be stored in the storage unit 10C, and can determine whether or not the endless chain 1 has a partial fracture with less information.

As a method of determination, for example, it may be determined whether or not the endless chain 1 is partially broken, based on whether or not the ratio of the difference calculated by the difference calculating means to the initial link length D0 exceeds a predetermined value.

For example, in the case where the chain equipment a of the present invention is a conveyor line of an automobile, if the elongation by local breakage after excluding the elongation by wear of the link length in which local breakage occurs in the endless chain 1 is of the order of 2 to 3mm, the elongation by local breakage of the link length by wear and the elongation by local breakage can be more clearly distinguished.

In a conveyor line for automobiles, a link length for the endless chain 1 is generally 150mm to 350 mm.

Therefore, as the predetermined value used for determining the ratio of the difference calculated this time to the initial link length D0, for example, in the case where the chain equipment a of the present invention is an automobile conveyor line, if it is 0.005 or more, it can be determined whether or not the annular chain 1 is partially broken, and more preferably 0.008 or more.

In the case of the configuration including the difference calculation means as in the first breakage determination method, it is preferable that the chain equipment a includes an automatic oil supply means, and the automatic oil supply means supplies oil to the endless chain 1 when the rate of change of the difference calculated by the difference calculation means becomes equal to or greater than a predetermined value.

Since the abrasion of the endless chain 1 is caused by the sliding of the links, the amount of abrasion of the endless chain 1 increases as the friction coefficient of the sliding portion increases. Thereby, the rate of change of the difference becomes large.

Since the friction coefficient of the sliding portion is greatly affected by the oil supply state of the chain, for example, when the rate of change of the difference becomes equal to or greater than a predetermined value, the automatic oil supply unit supplies oil to the endless chain 1, whereby the rate of change of the difference can be kept substantially constant, and therefore, it is possible to make it difficult for a crack to occur.

< confirmation of local breakage detection of endless chain by chain abnormality detection apparatus >

In the chain equipment a shown in the schematic plan view of fig. 1, in a state (F in the drawing) where the center link 11 of the link number 200 of the endless chain 1 is intentionally partially broken as shown in the plan view of fig. 7, the chain abnormality detection device 10 performs breakage determination by the first breakage determination method.

As can be seen from the graph showing the relationship between the link numbers and the difference in link length in fig. 8, only the difference in link length of the link number 200 is made larger than the difference in link length of the other numbers, and the local breakage of the center link 11 as shown in fig. 7 can be effectively detected.

In this way, by including the length of the local break F in the difference in link lengths, it is possible to clearly distinguish between elongation of the link length due to wear and elongation of the link length due to local break.

The length of the partial fracture F changes according to the tension acting on the endless chain 1, and as described above, the chain abnormality detection device 10 is preferably provided at a place where tension acts so as to clearly distinguish between the elongation of the link length due to wear and the elongation of the link length due to the partial fracture F.

Here, if the link is in a state in which no breakage occurs, the difference in link length can be regarded as elongation of the link length due to wear corresponding to the measurement period of the link length. In general, there is almost no difference in the wear amount of each link of the endless chain 1, and therefore, there is almost no difference in the difference in link length between the links in theory. However, as shown in the graph of fig. 8 showing the relationship between the link numbers and the differences in link lengths, the differences in link lengths may be different as a whole due to measurement errors caused by vibration of the endless chain 1 or the like.

Therefore, as a place where the chain abnormality detection device 10 is installed, the following places are preferable: the length of the local break F (elongation of the link length due to the local break F) is larger than the difference between the maximum value and the minimum value of the difference in link lengths calculated in the endless chain 1 in which the links are not broken.

Thus, the difference in link length of the link having only the local fracture F is more greatly increased than the difference in link length of the other links, and the local fracture F can be effectively detected.

Since the link length D in fig. 5 and 6 also includes the length of the side link 12, even if there is a local fracture in the side links 12 and 12 instead of the center link 11, the local fracture can be detected in the same manner.

According to the chain monitoring system of the embodiment of the present invention as described above, since the chain abnormality detection device 10 provided at a predetermined position of the circulation path C of the endless chain 1 in the chain facility a is compact and simple as shown in fig. 3 to 6, the installation space of the chain monitoring system is reduced and the increase in manufacturing cost can be suppressed.

Further, the sensors of the chain abnormality detecting device 10 are the reflection type photosensor 21, the transmission type photosensor 22, and the laser type CCD length measuring sensor 23, which are non-contact sensors that do not contact the endless chain 1, whereby an increase in maintenance cost can be suppressed.

Further, the chain abnormality detecting device 10 includes the measurement start position detecting means 21, the reference position detecting means 22, and the distance measuring means 23, and by these means, the link length of the endless chain 1 is sequentially measured for each of the link numbers 1, 2, 3, and … … and each of the link numbers, and whether or not the endless chain 1 is partially broken is determined by the first breakage determining method or the second breakage determining method, so that the partial breakage of the center link 11 and the partial breakage of the pair of side links 12 and 12 can be detected.

The above description of the embodiments is illustrative, and not restrictive. Various modifications and alterations can be made without departing from the scope of the invention.