JP2009180304A - Gear abnormality detection method, gear abnormality detection device and image forming device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear abnormality detection method, a gear abnormality detection device and an image forming device using the same which allow the replacement before a crack of a gear. <P>SOLUTION: A gear abnormality detection method for detecting abnormalities of respective gears A-E in a gear drive system consisting of a plurality of gears A-E, stores drive system data for indicating meshing frequencies of respective gears A-E and meshing data for indicating meshing frequency and amplitude value of a gear drive mechanism 48 in normal times, detects a rotational signal of the gear drive mechanism 48 and executes the Fourier transformation of the rotational signal so as to acquire the relationship between the frequency and amplitude value. On the basis of the meshing data and the frequency and amplitude value after the Fourier transformation, the amplitude value having a frequency bigger than the amplitude value in normal times has is acquired. In the gears A-E in the drive system data, any of the gear A-E corresponding to the frequency is specified as an abnormal part, which is displayed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gear abnormality detection method, a gear abnormality detection device, and an image forming apparatus using the same.

  In general, in an image forming apparatus, for example, a rotating body such as a photoconductor and a driving roller is used. These rotating bodies are rotated by receiving power from a power source through gears.

  In order to obtain a high-quality image, it is necessary to keep the rotational speed of these rotating bodies constant.

  For example, Patent Document 1 describes an image forming apparatus that keeps the number of rotations of a rotating body constant by detecting and correcting the amount of change in the rotational speed of the rotating body such as a drive roller for each rotating body. Yes.

  Patent Document 2 discloses an image in which rotation is controlled when rotation fluctuation of the photoconductor occurs, and the photoconductor can be rotated in a constant rotation state by adding a drive correction value for correcting the rotation fluctuation to the photoconductor. A forming apparatus is described.

  However, in any of the image forming apparatuses described in the patent documents, there is a problem in that the image quality deteriorates because the rotation speed cannot be kept constant if the gears that transmit the driving force to the photosensitive member and the driving roller are deteriorated and cracked. .

Japanese Patent Application No. 2004-309871 Japanese Patent Application No. 2000-327449

  The present invention has been made in view of the above-described conventional problems, and it is an object of the present invention to provide a gear abnormality detection method, a gear abnormality detection device, and an image forming apparatus using the gear abnormality detection method that can be exchanged before breaking the gear. To do.

  As a means for solving the above-mentioned problems, a gear abnormality detection method according to the present invention is a gear abnormality detection method for detecting abnormality of each gear of a gear drive system composed of a plurality of gears. Storing the drive system data and the meshing data indicating the meshing frequency and amplitude value of the gear drive system in a normal state, detecting the rotation signal of the gear drive system, and Fourier transforming the rotation signal to perform frequency and amplitude values Based on the frequency and amplitude value after the Fourier transform and the meshing data, a frequency that is larger than the amplitude value at normal time is obtained, and corresponds to the frequency among the gears of the drive system data. A gear to be operated is specified as an abnormal location, and the abnormal location is displayed. Here, the rotation signal is a pulse signal output at every fixed rotation speed, and means an output signal from an encoder, a Doppler sensor or the like, or an FG signal of a motor.

  If the gear has an abnormality such as wear, cracking or breakage, the rotation signal of the gear drive system is disturbed, and the amplitude value obtained by Fourier transforming this rotation signal changes. Therefore, the abnormal portion of the gear can be identified based on the frequency and amplitude values obtained by Fourier transforming the rotation signal, the mesh data, and the drive system data.

  Further, since the abnormal part of the gear is displayed, it is possible to detect an abnormality caused by the deterioration of the gear and replace it before the gear is deteriorated and cracked.

  In the gear abnormality detection device for detecting an abnormality of each gear of the gear drive system composed of a plurality of gears, drive system data indicating the meshing frequency of each gear, and the meshing frequency and amplitude of the gear drive system in a normal state Storage means for storing meshing data representing the rotation, rotation detection means for detecting a rotation signal of the gear drive system, calculation means for Fourier-transforming the rotation signal to obtain a relationship between a frequency and an amplitude value, and after the Fourier transformation A frequency that is greater than the amplitude value at the time of normality based on the frequency and amplitude value of the gear and the meshing data, and that identifies the gear corresponding to the frequency among the gears of the drive system data as an abnormal location It is preferable to have a means and a display means for displaying the abnormal part.

  Further, an image forming unit that forms a toner image on the photoconductor based on the image data, a transfer unit that transfers the toner image on the photoconductor to a sheet, and a fixing unit that fixes the toner image transferred to the sheet And a gear drive system that drives the image forming unit, the transfer unit, and the fixing unit via gears, and drive system data that indicates the meshing frequency of each gear, and the gear drive in a normal state. Storage means for storing meshing data representing the meshing frequency and amplitude of the system, rotation detecting means for detecting the rotation signal of the gear drive system, and arithmetic means for obtaining a relationship between the frequency and the amplitude value by Fourier transforming the rotation signal And, based on the frequency and amplitude value after the Fourier transform and the mesh data, obtain a frequency where the amplitude value is larger than the normal amplitude value, and the gear of the drive system data Specifying means for specifying a gear corresponding to Chi the frequency as abnormal part, a display means for displaying the abnormal place, it is preferable provided with a gear abnormality detection device including a.

  According to the gear abnormality detection method, the gear abnormality detection device and the image forming apparatus using the same according to the present invention, the abnormality portion of the gear is determined based on the frequency and amplitude values obtained by Fourier transforming the rotation signal, the mesh data, and the drive system data. Since it identifies, the more detailed abnormal part of a gear in a unit can be identified, and the workability of gear replacement improves.

  Further, since the abnormal part of the gear is displayed, the user can detect the abnormality due to the deterioration of the gear and replace it before the gear is deteriorated and broken.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows an image forming apparatus 12 that implements the gear abnormality detection method of the present invention and uses the gear abnormality detection device 11 of the present invention. First, a schematic configuration of the image forming apparatus 12 will be described. The image forming apparatus 12 includes an intermediate transfer belt 13 as an image carrier at a substantially central portion inside the image forming apparatus main body 12a. The intermediate transfer belt 13 is supported on the outer periphery of the rollers 14a and 14b and is driven to rotate in the direction of arrow A. The drive roller 14a is connected to a drive motor (not shown), and the driven roller 14b is driven to rotate as the drive roller 14a rotates. Below the lower horizontal portion of the intermediate transfer belt 13 are four print units 15Y, 15M, 15C, and 15K corresponding to the respective colors of yellow (Y), magenta (M), cyan (C), and black (K). Arranged along the transfer belt 13 side by side. The print units 15Y, 15M, 15C, and 15K have the same shape. Each print unit 15Y, 15M, 15C, 15K has a photosensitive drum 16, a developing device 17, and the like. Around each photosensitive drum 16, a primary transfer roller 18 facing each photosensitive drum 16 with the intermediate transfer belt 13 interposed therebetween is disposed. The developing device 17 communicates with a toner cartridge 21 detachably provided in a cartridge mounting portion 19 disposed above the intermediate transfer belt 13 via a toner supply passage (not shown). . A portion of the intermediate transfer belt 13 supported by the driving roller 14 a is in pressure contact with a secondary transfer roller (transfer roller) 23, and a nip portion between the secondary transfer roller 23 and the intermediate transfer belt 13 is a transfer portion 24. It has become. A fixing roller 26 and a pressure roller 27 are disposed further downstream of the sheet passing path 25 a, and the pressure contact portion serves as a fixing portion 28.

  A paper feeding unit 29 is provided below the image forming apparatus 12. The sheets S stacked and accommodated in the sheet feeding unit 29 are sent one by one from the uppermost one to the sheet passing path 25b. A circulation path 31 is provided on the side of the image forming apparatus 12. The single-sided printed paper that is switched back by the paper discharge roller 32 is conveyed downward through the circulation path 31, and is conveyed upward again through the paper passing path 25c with the unprinted surface facing the intermediate transfer belt 13 side. It has become so. A manual paper feeder 33 is provided below the circulation path 31. A sheet feeding roller 34 for feeding the sheet S is disposed in the sheet feeding path 25c from the manual sheet feeding device 33 and the sheet feeding unit 29 as representatively shown in FIG. Reference numeral 35 denotes an exposure unit 35 that exposes the print units 15Y, 15M, 15C, and 15K based on image signals.

  Next, a schematic operation of the image forming apparatus 12 having the above configuration will be described. Color print data obtained by reading an image with the image reading unit 36 or image data output from a personal computer or the like is subjected to predetermined signal processing by the exposure unit 35, and then yellow (Y), magenta (M ), Cyan (C), and black (K) image signals are supplied to the print units 15Y, 15M, 15C, and 15K. In each of the print units 15Y, 15M, 15C, and 15K, a laser beam modulated with an image signal is projected onto the respective photosensitive drums 16 to form an image latent image. Yellow, magenta, cyan, and black toner images are formed on each photosensitive drum 16. The formed yellow, magenta, cyan, and black toner images are primarily transferred onto the moving intermediate transfer belt 13 by being sequentially superimposed by the action of the primary transfer roller 18. The superimposed toner images formed on the intermediate transfer belt 13 in this way reach the transfer unit 24 as the intermediate transfer belt 13 moves. In the transfer unit 24, the superimposed toner images are secondarily transferred collectively onto the paper S supplied from the paper supply unit 29 or the manual paper supply device 33 by the action of the secondary transfer roller 23. Next, the sheet S on which the toner image is secondarily transferred reaches the fixing unit 28. In the fixing unit 28, the toner image is fixed on the paper S by the action of the fixing roller 26 and the pressure roller 27. The sheet S on which the toner image is fixed is discharged to a discharge tray 37 via a discharge roller 32.

  As shown in FIG. 2, the image forming apparatus 12 includes a gear abnormality detection device 11 that is configured around a CPU 41. The gear abnormality detection device 11 includes a CPU 41, a control unit 44 having a RAM 42 and a ROM 43 connected thereto, a rotation detection device 46 that detects the rotation of the gears A to E, and a display device 47 that displays the abnormal part. ing.

  The RAM 42 and ROM 43 of the control unit 44 constitute storage means of the present invention, and the CPU 41 constitutes calculation means and identification means of the present invention.

  The ROM 43 of the control unit 44 meshes the gears A to E of the drive device 48 that is a gear drive system such as the print units 15Y, 15M, 15C, and 15K, the transfer unit 24, and the fixing unit 28 of the image forming apparatus 12, for example. The drive system data (refer FIG. 3) showing a frequency and the meshing data (refer FIG. 4) showing the meshing frequency and amplitude of the drive device 48 at the time of normal are memorize | stored. The meshing frequency shown in FIG. 3 is obtained by multiplying the number of teeth by the number of rotations (rps).

  The drive device 48 includes a gear A that meshes with the drive gear of the motor 49, a gear B that meshes with the gear A, gears C and D that mesh with the gear B, and a gear E that meshes with the gear D. ing.

  The rotation detection device 46 can be configured to detect a signal from an encoder or a Doppler sensor attached to at least one of the gears A to E, but outputs from the motor 49 without using them. The detected FG signal can also be detected. A detection signal from the rotation detection device 46 is input to the control unit 44.

  The display device 47 is configured by a liquid crystal panel provided in the image forming apparatus 12.

  The CPU 41 of the control unit 44 detects an abnormality of the drive device 48 of the image forming apparatus 12 based on the detection signal from the rotation detection device 46 and the drive system data and meshing data stored in the ROM 43, and the signal Is displayed on the display device 47.

  Next, the operation of the gear abnormality detection device 11 having the above configuration, that is, the procedure of the gear abnormality detection method will be described. As shown in the flowchart of FIG. 5, in step S1, the rotation detector 46 detects the FG signal of the motor 49 shown in FIG. In step S2, the CPU 41 performs FFT analysis (fast Fourier transform) on the FG signal to calculate the frequency and amplitude as shown in FIG. If any of the gears A to E of the driving device 48 is worn, deteriorated, or damaged, the FG signal is disturbed, and the operation amplitude value of each frequency obtained by Fourier transforming this is changed. In step S <b> 3, the CPU 41 detects the calculated amplitude value of each frequency shown in the graph subjected to Fourier transform. In step S4, the CPU 41 determines whether or not the calculated amplitude value is larger than the target value by comparing the calculated amplitude value with the amplitude value of each normal frequency shown in FIG. If the calculated amplitude value is within, for example, twice the normal amplitude value, it is determined that the calculated amplitude value is appropriate, and the abnormality detection of the gears A to E is terminated.

  On the other hand, in step S4, if the CPU 41 determines that the calculated amplitude value is, for example, twice or more than the normal amplitude value as shown in FIG. 4 and FIG. It judges that it is improper, and it progresses to step S5, and CPU41 collates the frequency with which an operation amplitude value is improper, and the meshing frequency shown by the drive system data of ROM43 by step S5, and the gear which has an abnormal location A to E are specified. Specifically, in the drive system data of FIG. 3, the mesh frequency of 110 Hz indicates the mesh between the motor 49 and the gear A, and therefore it can be specified that the mesh is abnormal. In step S6, the CPU 41 outputs a signal for displaying the gear A identified as having an abnormality to the display device 47, and the abnormal location is displayed on the display device 47 as shown in FIG. In FIG. 7, a message notifying that an abnormal location has been detected, a specific abnormal location, and a message for prompting replacement of the abnormal gear are displayed, and the abnormal location is visually displayed on the illustration map with a surrounding line. Is displayed. In step S7, the service person repairs and replaces the gear A having the abnormal part based on the display.

  In order to confirm that the repaired and replaced gear A is properly driven, the process proceeds from step S7 to step S1 and similarly from step S1 to step S4. If it is determined in step S4 that the calculated amplitude value is appropriate, the display device 47 displays that the repair is completed and there is no abnormality as shown in FIG.

  Thus, since the gears A to E having the abnormal portions are displayed on the display device 47, the user can sense the abnormality due to the deterioration of the gears A to E and exchange them before breaking the gears A to E. .

  Since the gears A to E having an abnormal portion are specified based on the FG signal of the motor 49, the meshing data, and the drive system data, the gears A to E having a more detailed abnormal portion in the unit can be specified. The replacement workability is improved.

  In the embodiment, the FG signal of the motor 49 is used. However, an encoder or a Doppler sensor may be provided on at least one of the gears A to E to detect the rotation thereof. Further, the degree of abnormality of each gear A to E, for example, the degree of wear, cracks, or breakage can be known from the detected magnitude of the calculated amplitude value.

1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. The drive device provided with the gearwheel, and the block diagram of the gearwheel abnormality detection apparatus of this invention. Drive system data stored in the gear abnormality detection device of the present invention. The meshing data which shows the relationship between the frequency and amplitude value which the gear abnormality detection device of the present invention stores. The flowchart which shows abnormality detection control of the gear abnormality detection apparatus of this invention. (A) The graph which shows the FG signal which the motor of a drive device emits (b) The graph which shows the relationship between the frequency of each gear obtained by Fourier-transforming FG signal, and an amplitude value. The figure which displays the gearwheel detected that the display apparatus of this invention has an abnormal location. The figure which shows the state which the display apparatus of this invention displays that there is no abnormality in a gearwheel.

Explanation of symbols

11 Gear Abnormality Detection Device 12 Image Forming Device 41 CPU
42 RAM
43 ROM
44 Control Unit 46 Rotation Detection Device 47 Display Device 48 Drive Device (Gear Drive System)

Claims (3)

In a gear abnormality detection method for detecting abnormality of each gear of a gear drive system composed of a plurality of gears,
Storing drive system data indicating the meshing frequency of each gear, and meshing data indicating the meshing frequency and amplitude of the gear drive system in a normal state,
Detecting a rotation signal of the gear drive system;
Fourier transform the rotation signal to obtain the relationship between frequency and amplitude value,
Based on the frequency and the amplitude value after the Fourier transform, and the meshing data, a frequency whose amplitude value is larger than the normal amplitude value is obtained, and a gear corresponding to the frequency among the gears of the drive system data Is identified as an abnormal location,
An abnormality detection method for a gear, wherein the abnormality location is displayed. In the gear abnormality detection device for detecting abnormality of each gear of the gear drive system composed of a plurality of gears,
Storage means for storing drive system data indicating the meshing frequency of each gear, and meshing data indicating the meshing frequency and amplitude of the gear drive system in a normal state;
Rotation detection means for detecting a rotation signal of the gear drive system;
An arithmetic means for obtaining a relationship between a frequency and an amplitude value by Fourier transforming the rotation signal;
Based on the frequency and amplitude value after the Fourier transform and the mesh data, a frequency larger than the normal amplitude value is obtained, and the gear corresponding to the frequency among the gears of the drive system data is determined as an abnormal location. A specific means to identify as,
Display means for displaying the abnormal part;
A gear abnormality detection device comprising: An image forming unit that forms a toner image on a photoconductor based on image data; a transfer unit that transfers a toner image on the photoconductor to a sheet; and a fixing unit that fixes the toner image transferred to the sheet; In the image forming apparatus comprising a gear drive system that drives the image forming unit, the transfer unit, and the fixing unit via gears,
Storage means for storing drive system data indicating the meshing frequency of each gear, and meshing data indicating the meshing frequency and amplitude of the gear drive system in a normal state;
Rotation detection means for detecting a rotation signal of the gear drive system;
An arithmetic means for obtaining a relationship between a frequency and an amplitude value by Fourier transforming the rotation signal;
Based on the frequency and amplitude value after the Fourier transform and the mesh data, a frequency larger than the normal amplitude value is obtained, and the gear corresponding to the frequency among the gears of the drive system data is determined as an abnormal location. A specific means to identify as,
Display means for displaying the abnormal part;
An image forming apparatus comprising a gear abnormality detection device having