Passenger conveyor tooth skipping detection device

Abstract

To provide a tooth skipping detection device for a passenger conveyor capable of detecting tooth skipping of an output sprocket of a reducer.SOLUTION: A tooth skipping detection device for a passenger conveyor comprises a motor 20, a reducer 82 having an input shaft 84 connected to the rotating shaft of the motor 20, a plurality of steps 30 connected endlessly, a step sprocket 24 for driving the steps 30, a first sprocket 92 provided coaxially with the step sprocket 24, an endless drive chain 22 stretched between an output sprocket 90 of the reducer 82 and the first sprocket 92, a handrail drive wheel 72 driven by the step sprocket 24, a handrail driven wheel 74 which runs with the handrail drive wheel 72 and a handrail belt 38 sandwiched therebetween, an input shaft speed sensor 52 which outputs a first pulse signal corresponding to a first rotation speed of the input shaft 84, a handrail speed sensor 54 which outputs a second pulse signal corresponding to a second rotation speed of the handrail driven wheel 74, and a control unit 50 which detects a tooth skip of the output sprocket 90 based on the second pulse signal output during the output of a predetermined number of the first pulse signals.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a tooth skip detection device for a passenger conveyor. [Background technology]

[0002] Conventionally, passenger conveyors such as escalators and moving walkways rotate multiple steps in a circular manner using a drive device with a motor. In order to rotate the steps in a circular manner, multiple power transmission devices are interposed from the motor to the drive sprocket that drives the steps. Among them, the drive chain that transmits power between the output sprocket of the reducer connected to the motor and the drive sprocket is provided with a break sensor and a slack sensor to detect breaks and slack in the drive chain. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4504407 [Patent Document 2] Patent No. 6305321 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, a sensor is provided to detect abnormalities in the drive chain, but wear on the output sprocket of the reducer can cause the drive chain to unintentionally skip teeth. However, there has been a problem in the past in that there was no device to detect tooth skipping on the output sprocket. For example, if a tooth skip occurs on the output sprocket and causes other safety devices to accidentally activate and stop the passenger conveyor, it takes a lot of time to identify that the true cause is the tooth skipping on the output sprocket.

[0005] In view of the above problems, an embodiment of the present invention has an object to provide a tooth skipping detection device for a passenger conveyor that can detect tooth skipping of an output sprocket of a reduction gear. [Means for solving the problem]

[0006] An embodiment of the present invention includes a motor, a reducer whose input shaft is connected to the rotating shaft of the motor, a plurality of steps connected endlessly, a step sprocket that drives the steps, a first sprocket that is provided coaxially with the step sprocket, an endless drive chain that is stretched between the output sprocket of the reducer and the first sprocket, a handrail drive wheel that is driven by the step sprocket, a handrail driven wheel that runs with a handrail belt sandwiched between the handrail drive wheel and the handrail belt, a first speed sensor that outputs a first pulse signal corresponding to a first rotation speed of the input shaft, a second speed sensor that outputs a second pulse signal corresponding to a second rotation speed of the handrail driven wheel, a control unit that detects tooth skipping of the output sprocket based on the second pulse signal output while a predetermined number of first pulse signals are output, and a When the steps are ascending, the control unit determines that the output sprocket is skipping teeth if the second pulse signal continues to be ON or OFF while a predetermined number of the first pulse signals are being output. This is a tooth skipping detection device for passenger conveyors. Another embodiment of the present invention includes a motor, a reducer whose input shaft is connected to the rotating shaft of the motor, a plurality of steps connected endlessly, a step sprocket that drives the steps, a first sprocket that is provided coaxially with the step sprocket, an endless drive chain that is stretched between an output sprocket of the reducer and the first sprocket, a handrail drive wheel that is driven by the step sprocket, a handrail driven wheel that runs with a handrail belt sandwiched between the handrail drive wheel and the handrail belt, a first speed sensor that outputs a first pulse signal corresponding to a first rotation speed of the input shaft, a second speed sensor that outputs a second pulse signal corresponding to a second rotation speed of the handrail driven wheel, and a control unit that detects tooth skipping of the output sprocket based on the second pulse signal output while a predetermined number of the first pulse signals are output. and when the steps are moving downward, the control unit determines that the output sprocket is skipping teeth if the pulse interval of the second pulse signal is narrower than the pulse interval of the second pulse signal in a normal state in which no skipping occurs while a predetermined number of pulses of the first pulse signal are being output. This is a tooth skipping detection device for passenger conveyors. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is an explanatory diagram of the escalator of the first embodiment as viewed from the left side. [Diagram 2] FIG. 2 is an enlarged explanatory diagram of the drive unit, step sprocket, handrail sprocket, and handrail drive unit. [Diagram 3] FIG. [Figure 4] 4 is a time chart showing a state in which the output sprocket is in a normal state. [Diagram 5] 11 is a time chart showing a state in which tooth skipping occurs in an output sprocket during an ascending operation. [Figure 6] 11 is a time chart showing a state in which tooth skipping occurs in an output sprocket during a descending operation. [Figure 7] 11 is a time chart showing a state in which the handrail belt slips during operation. [Figure 8] FIG. 11 is an explanatory diagram of a drive device, a step sprocket, and a handrail sprocket in the second embodiment. [Figure 9] FIG. 11 is an explanatory diagram of the drive unit, step sprockets, and handrail sprockets during normal descent operation in the second embodiment. [Figure 10] FIG. 11 is an explanatory diagram of the drive unit, step sprocket, and handrail sprocket during descent operation when one tooth skips in the second embodiment. [Figure 11] 11 is an actual time chart showing a state in which tooth skipping occurs in an output sprocket during a descending operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a tooth skipping detection device for a passenger conveyor according to an embodiment of the present invention will be described with reference to the drawings. In the embodiment, an escalator 10 will be described as the passenger conveyor.

[0009] An escalator 10 according to a first embodiment of the present invention will be described with reference to FIGS.

[0010] (1) Escalator 10 First, the structure of escalator 10 will be described. Fig. 1 is an explanatory diagram of escalator 10 as seen from the left side. However, in order to make the internal structure of escalator 10 easier to understand, illustration of components on one side (the left side) of escalator 10 is omitted. Note that when describing the front-to-rear direction of escalator 10, it is assumed that the viewer is looking down from an upper floor to a lower floor, with the upper floor being the rear side and the lower floor being the front side.

[0011] A truss 12, which is the framework of an escalator 10, is supported across the upper and lower floors of a building 1 using support angles 2 and 3.

[0012] Inside the upper floor machine room 14 at the top end of the truss 12, there are provided a drive unit 18 for driving the steps 30, a pair of left and right step sprockets 24, 24, and a pair of left and right handrail sprockets 27, 27. The drive unit 18 has a motor 20 and a reducer 82. The drive chain 22 is driven by an output sprocket 90 attached to the output shaft of the reducer 82, and the step sprocket 24 rotates. The pair of left and right step sprockets 24, 24 and the pair of left and right handrail sprockets 27, 27 are connected by a connecting belt and rotate synchronously. The structures of the drive unit 18, the step sprocket 24, and the handrail sprocket 27 will be explained in detail later. Inside the upper floor machine room 14, there is provided a control unit 50 for controlling the motor 20 and the like.

[0013] A driven sprocket 26 is provided inside the lower floor machine room 16 at the lower end of the truss 12. A pair of endless step chains 28, 28 are stretched between the step sprocket 24 on the upper floor side and the driven sprocket 26 on the lower floor side. That is, wheels 301 of a plurality of steps 30 are attached at equal intervals to the pair of step chains 28, 28 on the left and right. The wheels 301 of the steps 30 run along a guide rail (not shown) fixed to the truss 12, and engage with a recess on the outer periphery of the step sprocket 24 and a recess on the outer periphery of the driven sprocket 26 to turn upside down. The wheels 302 run on a guide rail 25 fixed to the truss 12.

[0014] A pair of left and right balustrades 36, 36 are erected on the left and right sides of the truss 12. A handrail rail 39 is provided on the top of the balustrade 36, and an endless handrail belt 38 moves along this handrail rail 39. An upper floor front skirt guard 40 is provided on the lower front part of the upper floor side of the balustrade 36, and a lower floor front skirt guard 42 is provided on the lower front part of the lower floor side, and inlets 46, 48, which are entrances and exits for the handrail belt 38, protrude from the front skirt guards 40, 42, respectively.

[0015] A skirt guard 44 is provided on the lower side of the balustrade 36, and the steps 30 run between a pair of left and right skirt guards 44, 44.

[0016] When the escalator 10 is operating in an upward direction, the pair of left and right handrail belts 38 each enter the front skirt guard 40 from the inlet portion 46 on the upper floor side, and each handrail belt 38 is driven by a handrail drive device 70 driven by the handrail sprocket 27, moves within the skirt guard 44, and emerges outside the front skirt guard 42 from the inlet portion 48 on the lower floor side. When the escalator 10 is operating in a downward direction, it enters the skirt guard 44 from the inlet portion 48 on the lower floor side, and emerges outside the front skirt guard 40 from the inlet portion 46 on the upper floor side.

[0017] An upper floor boarding / alighting plate 32 is provided horizontally at the boarding / alighting opening on the ceiling surface of the upper floor machine room 14, and a lower floor boarding / alighting plate 34 is provided horizontally at the boarding / alighting opening on the ceiling surface of the lower floor machine room 16. A comb-tooth-shaped comb 60 is provided at the tip of the boarding / alighting plate 32, and the steps 30 advance from or enter this comb 60. A comb-tooth-shaped comb 62 is also provided on the boarding / alighting plate 34.

[0018] (2) Structure of the drive unit 18, step sprocket 24, and handrail sprocket 27 Next, the structures of the drive unit 18, the step sprocket 24, and the handrail sprocket 27 will be described with reference to FIGS.

[0019] The drive unit 18 is installed on the truss 12 in the machine room 14 on the upper floor, and as shown in Fig. 3, the rotating shaft 86 of the motor 20 is connected to the input shaft 84 of the reducer 82 via a coupling device 88. Note that the means for connecting the input shaft 84 and the rotating shaft 86 is not limited to the coupling device 88, and a V-belt may also be used.

[0020] 2 and 3, an output sprocket 90 is provided on the output shaft of the reduction gear 82. Output teeth (not shown) protrude from the outer periphery of the output sprocket 90 at regular intervals.

[0021] As shown in Fig. 2, a first sprocket 92 is provided coaxially with the step sprocket 24. An endless drive chain 22 is stretched between the output sprocket 90 of the reducer 82 and the first sprocket 92. A second sprocket 94 is also attached coaxially with the step sprocket 24. In addition, a third sprocket 96 is provided coaxially with the handrail sprocket 27. An endless transmission chain 98 is stretched between the second sprocket 94 and the third sprocket 96.

[0022] 2 and 3, an input shaft speed sensor (first speed sensor) 52 made of a proximity sensor is provided on the input shaft 84 of the reducer 82, and outputs a first pulse signal having a pulse interval corresponding to a first rotation speed, which is the rotation speed of the input shaft 84, to the control unit 50. For example, a detection piece is provided on the input shaft 84, and the input shaft speed sensor 52, which is a proximity sensor, detects the detection piece every time the input shaft 84 rotates once and outputs one pulse (first pulse signal). The control unit 50 detects the stoppage of operation and deceleration of the motor 20 based on the first pulse signal of the input shaft speed sensor 52, and also detects an abnormality in the V-belt if a V-belt is used.

[0023] As shown in FIG. 2, the drive chain 22 is stretched between the output sprocket 90 and the step sprocket 24, so that when the motor 20 of the drive unit 18 rotates, the output sprocket 90 of the reducer 82 rotates together with it, and the first sprocket 92 rotates via the drive chain 22. When the first sprocket 92 rotates, the step sprocket 24 rotates and the step 30 moves. When the step sprocket 24 rotates clockwise in FIG. 2, the step 30 rises, and when it rotates counterclockwise, the step 30 descends. With the rotation of the first sprocket 92, the second sprocket 94 also rotates, and the third sprocket 96 rotates via the transmission chain 98. When the third sprocket 96 rotates, the handrail sprocket 27 rotates, which drives the handrail drive unit 70 described next, and the handrail belt 38 moves.

[0024] (3) Structure of the handrail drive device 70 Next, the handrail drive device 70 will be described with reference to Figures 1 and 2. The handrail drive device 70 is provided inside the escalator 10, surrounded by the skirt guard 44. The handrail drive device 70 is of a linear drive type, and has a horizontally elongated base plate 64 provided above the truss 12 and inside the skirt guard 44, four handrail drive wheels 72, four handrail driven wheels 74, four handrail drive sprockets 66, and an auxiliary sprocket 68.

[0025] 1, the four handrail drive sprockets 66 are aligned horizontally in a straight line and rotatably mounted on the base plate 64. An auxiliary sprocket 68 is provided between the two central handrail drive sprockets 66, 66. No handrail drive wheels 72 are attached to the auxiliary sprocket 68.

[0026] As shown in FIG. 1, the four handrail drive wheels 72 arranged in a straight line are attached coaxially to the four handrail drive sprockets 66 , and the handrail drive wheels 72 rotate together with the handrail drive sprockets 66 .

[0027] On the base plate 64, four handrail driven wheels 74 are provided below the four handrail drive wheels 72, aligned in a straight line so as to face each of the four handrail drive wheels 72. The handrail belt 38 runs between the four handrail drive wheels 72 and the four handrail driven wheels 74, and the four handrail driven wheels 74 press the handrail belt 38 against the four handrail drive wheels 72.

[0028] Two guide sprockets 76, 78 are rotatably provided between the handrail sprocket 27 and the handrail drive device 70 described above. An endless handrail chain 80 is stretched across the handrail sprocket 27, the four handrail drive sprockets 66, the one auxiliary sprocket 68, and the guide sprockets 76, 78. In other words, the handrail chain 80 passes over the lower circumferential surface of the handrail sprocket 27, the upper circumferential surface of the first handrail drive sprocket 66, the upper circumferential surface of the second handrail drive sprocket 66, the lower circumferential surface of the auxiliary sprocket 68, the upper circumferential surface of the third handrail drive sprocket 66, and the upper circumferential surface of the fourth handrail drive sprocket 66, guided by the guide sprockets 76 and 78, before returning to the handrail sprocket 27.

[0029] As a result, when the handrail sprocket 27 rotates in sync with the step sprocket 24 that drives the steps 30, the four handrail drive wheels 72 that are mounted coaxially with the four handrail drive sprockets 66 also rotate. Then, the handrail belt 38 sandwiched between the four rotating handrail drive wheels 72 and the four handrail driven wheels 74 runs.

[0030] Of the four handrail driven wheels 74 described above, one of the handrail driven wheels 74 is provided with a handrail speed sensor (second speed sensor) 54 made of a proximity sensor. This handrail speed sensor 54 outputs a second pulse signal having a pulse interval corresponding to the second rotation speed, which is the rotation speed of the handrail driven wheel 74, to the control unit 50. For example, a detection piece is provided on the handrail driven wheel 74, and the handrail speed sensor 54, which is a proximity sensor, detects the detection piece every time the handrail driven wheel 74 rotates once and outputs one pulse (second pulse signal). The control unit 50 detects the stoppage, slippage, etc. of the handrail belt 38 based on the second pulse signal of the handrail speed sensor 54.

[0031] (4) Device for detecting skipped teeth of output sprocket 90 Next, the tooth skipping detection device for the output sprocket 90 of the reduction gear 82 will be described with reference to Figs. 4 to 7. The tooth skipping detection device is composed of the control unit 50, the input shaft speed sensor 52, and the handrail speed sensor 54. Here, "tooth skipping" refers to a phenomenon in which the gears (output teeth) of the chain, sprocket, etc. do not mesh well, and when force is applied, the chain slips, and the input force is not transmitted to the driven object. In the time charts of Figs. 4 to 7, the horizontal axis is time t, and the vertical axis shows, from top to bottom, a conceptual diagram of the state of the output teeth of the output sprocket 90, the waveform of the first pulse signal output by the input shaft speed sensor 52, and the waveform of the second pulse signal output by the handrail speed sensor 54.

[0032] The diagrams in the first column are conceptual diagrams of output teeth in which a vertical line is displayed when the output tooth of the output sprocket 90 rotates by one revolution, with a solid vertical line indicating that the output tooth operates normally and a dotted vertical line indicating that the output tooth has skipped due to wear, etc. The time required for one output tooth to rotate to the position of the adjacent output tooth is designated as a.

[0033] The first pulse signal in the second row is output with the rotation of the input shaft 84, and when the first rotation speed, which is the rotation speed of the input shaft 84, is constant, the pulse signal has a constant pulse interval. A predetermined number of pulses are output during the time a required for one output tooth to rotate. For example, when the input shaft 84 rotates twice, the first pulse signal outputs two pulses as shown in Figs. 4 to 7.

[0034] The second pulse signal in the third column is output along with the rotation of the handrail driven wheel 74, and when the second rotation speed, which is the rotation speed of the handrail driven wheel 74, is constant, the pulse signal has a constant pulse interval. If the handrail driven wheel 74 rotates four times during the time a required for one output tooth to rotate, for example, the second pulse signal will output four pulses as shown in Figure 4, and the faster the second rotation speed becomes, the more pulses there are during the time a (see Figure 6).

[0035] (4-1) Normal state A case where the output teeth of the output sprocket 90 are in a normal state will be described with reference to the time chart of FIG.

[0036] When the output teeth of the output sprocket 90 are normal, the solid vertical line in the conceptual diagram of the output teeth protrudes every time a, which is the time it takes for one output tooth to rotate. The number of pulses of the first pulse signal during this time a can be calculated from the rotational speed of the motor 20, the reduction ratio of the reducer 82, and the number of output teeth of the output sprocket 90. Fig. 4 is an example of a normal state, in which the first pulse signal includes two pulses with a constant pulse interval during the time a, and the second pulse signal includes four pulses with a constant pulse interval during the time a.

[0037] When the control unit 50 receives the first pulse signal and the second pulse signal in such a state, it determines that no tooth skipping has occurred in the output teeth of the output sprocket 90.

[0038] (4-2) Tooth skipping during ascent In the following, detection of a tooth skip when a tooth skip occurs by one tooth (n=1), that is, when a first pulse signal of two pulses is output, will be described. However, even if a tooth skip occurs, the time is usually short and there is little change in the second pulse signal, so detection when multiple tooth skips occur is more clear. In that case, the number of first pulse signals during a time period x n (n>1) is counted. This n may be determined in advance.

[0039] First, a case where a tooth skip occurs in an output tooth of the output sprocket 90 while the steps 30 are moving upward will be described with reference to the time chart of FIG.

[0040] In the conceptual diagram of the first row of output teeth in the time chart of FIG. 5, the dotted vertical line indicates that one tooth has skipped.

[0041] Regarding the input shaft 84, since it is located before the output sprocket 90 in the power transmission system, the first pulse signal has a constant pulse number and pulse interval, similar to the pulse signal when the output teeth are normal.

[0042] Regarding the second pulse signal, since a tooth skip occurs in the output tooth of the output sprocket 90, the drive chain 22 stops temporarily, the step sprocket 24 does not rotate, and the steps 30 also stop temporarily, and the stop time at that time is proportional to the number of teeth skipped. In other words, it is the product of the time a required for the output sprocket 90 to rotate by one output tooth and the number of teeth n where a tooth skip occurs. In FIG. 5, the number of teeth is n=1. When the drive chain 22 stops, the stop is transmitted in order to the first sprocket 92, the step sprocket 24, the second sprocket 94, the third sprocket 96, and the handrail sprocket 27, and further to the handrail chain 80 and the handrail drive wheel 72. During that time, the movement of the handrail belt 38 stops, so the handrail driven wheel 74 does not rotate either, and the handrail speed sensor 54 cannot detect the rotation of the handrail driven wheel 74, and the second pulse signal does not change. That is, the ON or OFF state of the second pulse signal continues for a time a (where n=1).

[0043] If, during ascending operation, the first pulse signal of the input shaft speed sensor 52 is normal but the second pulse signal of the handrail speed sensor 54 stops for a certain period of time (n times time a), the control unit 50 determines that a tooth skip has occurred in the output sprocket 90 and records this, and if necessary, reports it to the outside.

[0044] (4-3) Tooth skipping during descent Next, a case where a tooth skip occurs in the output sprocket 90 when the steps 30 are descending will be described with reference to the time chart of FIG.

[0045] The conceptual diagram of the output teeth and the first pulse signal of the input shaft speed sensor 52 are similar to those in the case where tooth skipping occurs during the above-mentioned ascending operation.

[0046] If the output sprocket 90 skips one tooth during a descending operation, the force driving the drive chain 22 is lost, and the step 30 descends to the lower floor due to its own weight, so that the drive chain 22 is pulled by the movement of the step 30, and the step sprocket 24 momentarily rotates faster than the rotation speed of the output sprocket 90. Then, the high-speed rotation is transmitted to the first sprocket 92, the step sprocket 24, the second sprocket 94, the third sprocket 96, and the handrail sprocket 27, and further to the handrail driving wheel 72, so that the handrail belt 38 also moves at a high speed temporarily. As a result, the handrail driven wheel 74 also rotates at a high speed, and the second pulse signal of the handrail speed sensor 54 has a narrower pulse interval due to this abnormal acceleration. For example, FIG. 6 shows an example in which the pulse is compressed to 1 / 2 on average during a time. However, the extent to which the pulse interval becomes narrower is determined by the number of output teeth on output sprocket 90, first sprocket 92, step sprocket 24, second sprocket 94, third sprocket 96, and handrail sprocket 27 and the ratio of the numbers of output teeth, and 1 / 2 is an example. Note that a case in which one tooth skip occurs on output sprocket 90 during this descending operation will be explained more clearly using embodiment 2, which has a simpler structure than embodiment 1.

[0047] When the first pulse signal is normal and the pulse interval of the second pulse signal is narrower than normal during a downward operation, the control unit 50 determines that a tooth skip has occurred in the output sprocket 90, records this, and notifies the outside if necessary.

[0048] (4-4) In case of slippage of the handrail belt 38 during ascending or descending operation There are cases where the output sprocket 90 does not have a tooth jump, but the handrail belt 38 slips while moving. The difference between this slip state and the state when a tooth jump occurs will be explained with reference to the time chart in FIG.

[0049] The conceptual diagram of the output teeth and the first pulse signal of the input shaft speed sensor 52 are the same as in the normal state.

[0050] However, if the handrail belt 38 slips for some reason, the handrail driving wheel 72 rotates normally, but the speed of the handrail belt 38 drops, causing the handrail driven wheel 74 to also drop, and at least one of the pulse width and pulse interval of the second pulse signal of the handrail speed sensor 54 becomes wider than normal. This makes it possible to distinguish this from a tooth skip of the output sprocket 90.

[0051] In this way, when the pulse width or pulse interval of the second pulse signal from the handrail speed sensor 54 becomes wider than normal even though the first pulse signal from the input shaft speed sensor 52 is normal, the control unit 50 determines that slippage of the handrail belt 38 has occurred rather than a tooth skip.

[0052] (5) Effects According to this embodiment, tooth skipping of the output sprocket 90 can be reliably detected whether the escalator 10 is in an ascending or descending operation.

[0053] In addition, slippage of the handrail belt 38 can be distinguished from tooth skipping, and slippage of the handrail belt 38 can also be detected.

[0054] In addition, the input shaft speed sensor 52 and the handrail speed sensor 54 can be the ones already installed to detect the speed of the motor 20 and the speed of the handrail belt 38, respectively, so there is no need to install new ones to detect tooth skipping of the output sprocket 90, and there is no increase in cost or installation work.

[0055] Next, an escalator 10 according to a second embodiment will be described with reference to Fig. 8. This embodiment differs from the first embodiment in that the structure for driving the handrail belt 38 is different.

[0056] In this embodiment, it is not the handrail sprocket 27 that is coaxially attached to the third sprocket 96, but rather the handrail drive wheel 100 that drives the handrail belt 38. In order to press the handrail belt 38 against this handrail drive wheel 100, multiple handrail driven wheels 102 are provided on the lower outer periphery of the handrail drive wheel 100. A handrail speed sensor 54 is provided on one of these handrail driven wheels 102. In addition, multiple guide rollers 104 that guide the handrail belt 38 to the handrail drive wheel 100, and multiple guide rollers 106 that guide the handrail belt 38 from the handrail drive wheel 100 into the inside of the skirt guard 44 are provided.

[0057] As a result, the second sprocket 94 rotates together with the step sprocket 24, and when the third sprocket 96 rotates via the transmission chain 98, the handrail drive wheel 100 rotates and moves the handrail belt 38. When the handrail belt 38 moves, the handrail driven wheel 102 also rotates, and the handrail speed sensor 54 outputs a second pulse signal corresponding to the speed of the handrail belt 38.

[0058] In this embodiment, too, it is possible to detect tooth skipping of the output sprocket 90 during ascending or descending operation in the same manner as in the above-described embodiment 1. Furthermore, it is also possible to detect slippage of the handrail belt 38, in distinction from tooth skipping.

[0059] Based on this embodiment, a case where one tooth skip occurs in the output sprocket 90 of the reduction gear 82 during a downward operation will be described with reference to Figs.

[0060] 9 and 10, during descending operation, the output sprocket 90, the first sprocket 92, the second sprocket 94, the third sprocket 96, and the handrail drive wheel 100 rotate counterclockwise, and the handrail driven wheel 102 rotates clockwise. In the drawings, one of the reference teeth is represented by a thick line so that the rotation state can be seen.

[0061] As shown in Figure 9, under normal circumstances, four pulse rises occur while the output sprocket 90 advances one tooth from the 0 o'clock position (see Figure 9(a)) to the 9 o'clock position (see Figure 9(b)) (corresponding to time a in Figure 11), and the handrail drive wheel 100 (the detection piece of the handrail speed sensor 54) rotates from the 0 o'clock position to the 4 o'clock position (four pulses).

[0062] As shown in FIG. 10, if a tooth skip occurs at the 0 o'clock position (see FIG. 10(a)) of the output sprocket 90 of the reducer 82 during descent operation, the handrail drive wheel 100 rotates from 0 to 4 o'clock position (see FIG. 10(b)) due to the idling of the drive chain 22. During that time, the output sprocket 90 rotates from 0 to 9 o'clock position as usual, so the handrail drive wheel 100 rotates from 4 to 8 o'clock position (see FIG. 10(c)). The above occurs while the output sprocket 90 advances one tooth (time a in FIG. 11), and the handrail speed sensor 54, which has a detection piece that rotates in the same way as the handrail drive wheel 100, generates 8 pulses, which is twice as long as usual. As shown in FIG. 6, when averaged within time a, the pulse interval is 1 / 2 of the normal interval, but in reality, as shown in FIG. 11, the interval is extremely narrow only immediately after the tooth skip, and becomes normal halfway through. In other words, the drive chain 22 is caught on the tooth behind the tooth skip. Modified Example

[0063] In the above embodiment, proximity sensors were used for the input shaft speed sensor 52 and the handrail speed sensor 54, but instead, high-resolution sensors such as an encoder that rotates with the input shaft 84 or a rotary encoder that rotates with the handrail driven wheel 74 may be used.

[0064] Furthermore, in the above embodiment, the present invention has been described as being applied to the escalator 10, but it may instead be applied to a moving walkway.

[0065] In addition, although one embodiment of the present invention has been described above, this embodiment is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0066] DESCRIPTION OF SYMBOLS 10 escalator, 18 drive device, 20 motor, 22 drive chain, 24 step sprocket, 27 handrail sprocket, 28 step chain, 30 step, 38 handrail belt, 52 input shaft speed sensor, 54 handrail speed sensor, 70 handrail drive device, 72 handrail drive wheel, 74 handrail driven wheel, 80 handrail chain, 82 reducer, 84 input shaft, 90 output sprocket

Claims

1. A motor; a reducer having an input shaft connected to a rotating shaft of the motor; A plurality of steps connected endlessly; A step sprocket that drives the steps; A first sprocket provided coaxially with the step sprocket; an endless drive chain stretched between an output sprocket of the reducer and the first sprocket; A handrail drive wheel driven by the step sprocket; A handrail driven wheel that runs by sandwiching the handrail driving wheel and the handrail belt; a first speed sensor that outputs a first pulse signal corresponding to a first rotation speed of the input shaft; A second speed sensor that outputs a second pulse signal corresponding to a second rotation speed of the handrail driven wheel; a control unit that detects tooth skipping of the output sprocket based on the second pulse signal output while a predetermined number of the first pulse signals are output; having When the steps are moving upward, the control unit determines that the output sprocket is skipping teeth if the second pulse signal continues to be ON or OFF while a predetermined number of the first pulse signals are being output. A tooth skipping detection device for passenger conveyors.

2. A motor; a reducer having an input shaft connected to a rotating shaft of the motor; A plurality of steps connected endlessly; A step sprocket that drives the steps; A first sprocket provided coaxially with the step sprocket; an endless drive chain stretched between an output sprocket of the reducer and the first sprocket; A handrail drive wheel driven by the step sprocket; A handrail driven wheel that runs by sandwiching the handrail driving wheel and the handrail belt; a first speed sensor that outputs a first pulse signal corresponding to a first rotation speed of the input shaft; A second speed sensor that outputs a second pulse signal corresponding to a second rotation speed of the handrail driven wheel; a control unit that detects tooth skipping of the output sprocket based on the second pulse signal output while a predetermined number of the first pulse signals are output; having When the steps are descending, the control unit determines that the output sprocket is skipping teeth if the pulse interval of the second pulse signal is narrower than the pulse interval of the second pulse signal in a normal state where no skipping occurs while a predetermined number of pulses of the first pulse signal are being output. A tooth skipping detection device for passenger conveyors.

3. The predetermined number of pulses of the first pulse signal is the number of pulses output during a time equal to the product of a time required for the output sprocket to rotate by one output tooth and a predetermined number of teeth n (n=>1).

3. The tooth skipping detection device for a passenger conveyor according to claim 1 or 2.

4. Handrail sprocket; A second sprocket provided coaxially with the step sprocket; A third sprocket provided coaxially with the handrail sprocket; an endless transmission chain stretched between the second sprocket and the third sprocket; an endless handrail chain stretched across a plurality of the handrail drive wheels and the handrail sprockets; 3. The tooth skipping detection device for a passenger conveyor according to claim 1 or 2, further comprising:

5. A second sprocket provided coaxially with the step sprocket; A third sprocket provided coaxially with one of the handrail drive wheels; an endless transmission chain stretched between the second sprocket and the third sprocket; 3. The tooth skipping detection device for a passenger conveyor according to claim 1 or 2, further comprising:

Images