JP2005278348A - Regenerated energy utilizing device of dc motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regenerated energy utilizing device of a DC motor that further reduces power supply to an image forming device effectively utilizing regenerated energy of a motor that drives a load. <P>SOLUTION: This regenerated energy utilizing device of a DC motor, provided with: a DC motor M that drives a prescribed load; a control circuit 6 that controls the drive of the DC motor M to prescribed revolutions; and a capacitor 5 that accumulates electric power when the DC Motor M is braked by regeneration by the control circuit 6, includes an accumulated power supply circuit 3 that supplies the accumulated power in the capacitor 5 when the DC motor M is started. The regenerated energy utilizing device that further reduces power supply to the image forming device effectively is obtained utilizing the regenerated energy of the DC motor that drives the load. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a DC motor regenerative energy utilization device, and more particularly to a DC motor regenerative energy utilization device used for a main drive motor of an electrophotographic image forming apparatus.

  Power-saving mode control that stops power supply to heaters and other loads of thermal fixing devices that do not need to be operated during standby to reduce power consumption during standby for image forming devices that use electrophotographic systems such as copying machines The technology for reducing power consumption is attracting more attention.

On the other hand, in a step motor drive control device that rotates a rotor by sequentially switching a plurality of excitation phases, the regenerative current generated in the excitation coil of the excitation phase that is turned off by switching the excitation phase is temporarily stored in the capacitor. A technique for securing torque even at high speed rotation has been proposed by making the above voltage higher than the power supply voltage and using this increased voltage for driving the exciting coil of the exciting phase to be newly excited.
Japanese Patent Laid-Open No. 8-223993

  However, according to the prior art described in Patent Document 1 described above, the back electromotive force obtained in the excitation phase of the step motor is very small and is used only for excitation of the next excitation coil of the same step motor. There is room for further improvement in that the power supplied to the image forming apparatus is more effectively used. The generated power is consumed directly during the operation of the device, and if the load is driven with a fluctuating generated power, there is a possibility that it cannot be stably driven, and there is a possibility that the copying job may be hindered. was there.

  In view of the above-described conventional drawbacks, the present invention provides a regenerative energy utilization device for a DC motor that can further reduce the power supplied to an image forming apparatus by effectively utilizing the regenerative energy of a motor that drives a load. In the point.

  In order to achieve the above-described object, the regenerative energy utilization apparatus for a DC motor according to the present invention includes a DC motor for driving a predetermined load, and the DC motor as described in claim 1 of the claims. A control circuit that drives and controls the motor to a predetermined number of revolutions; and a capacitor that stores electric power generated when the DC motor is regeneratively braked by the control circuit, and the electric power stored in the capacitor is activated A storage power supply circuit that is sometimes supplied is provided, and the regenerative energy of the DC motor is stored in the battery as direct current power, and the power is supplied at startup when the DC motor consumes the most power. To get.

  The DC motor is preferably a main drive motor of an electrophotographic image forming apparatus. If such a main drive motor is used, the inertial force is large, and a larger generated power can be obtained when regenerative braking is performed.

  In addition, it is preferable to provide a stored power supply circuit that supplies power stored in the battery to another load mounted on the image forming apparatus in terms of reducing the consumption of commercial power.

  Furthermore, it is preferable to provide a storage power supply circuit that supplies the power stored in the capacitor to a load in the power saving mode of the image forming apparatus, and in a power saving mode in which a large load does not operate. This is effective in that power can be supplied stably and consumption of commercial power can be reduced.

  As described above, according to the present invention, there is provided a regenerative energy utilization device for a DC motor that can further reduce the power supplied to the image forming apparatus by effectively utilizing the regenerative energy of the motor that drives the load. I was able to do it.

  An example in which the DC motor regenerative energy utilization apparatus according to the present invention is applied to an image forming apparatus will be described below. As shown in FIG. 1, a digital copying machine 1 as an example of an image forming apparatus has an upper surface of a main body on which an exposure mechanism 2 as an image reading unit for reading document image information, a printing mechanism 3 and a recording paper transport mechanism 4 are arranged. A contact glass 5 for placing a document to be copied (copied document) and an operation display unit 6 are provided. An automatic document feeder 7 is disposed on the contact glass 5, and a paper feed cassette is provided on one side of the main body. 8 is arranged.

  The exposure mechanism 2 includes a first slider 2A including an exposure lamp 21 for exposing and scanning a document placed on the contact glass 5, and a first mirror 22 for reflecting reflected light from the document, and a first mirror. A second slider 2B having second and third mirrors 23 and 24 for guiding the light reflected by the lens 22 to the lens 25, and a CCD for converting the optical information obtained by the condenser lens 25 into an electrical signal. And the like, a control unit 27 to which image information obtained by the solid-state image sensor 26 is input, and a laser unit 28 that converts image data from the control unit 27 into an optical signal.

  The print mechanism 3 includes a photosensitive drum 31 that is driven to rotate in the direction of an arrow by a main drive motor (not shown), and the surface of the photosensitive drum 31 is exposed around the photosensitive drum 31 in the order of the rotation direction. A charger 32 for charging the layer, a developing device 33 for visualizing the electrostatic latent image formed on the photosensitive layer as a toner visible image, and a transfer device for transferring the toner visible image formed on the photosensitive layer to recording paper Discharger 34, separation discharger 35 for separating the recording paper from the photosensitive drum 31, cleaning device 36 for removing toner remaining on the photosensitive drum 31 after transfer, and charge on the surface of the photosensitive drum 31 Each of the static eliminators 37 is disposed to irradiate the photosensitive layer uniformly charged by the charger 32 with the laser beam output from the laser unit 28, thereby forming an electrostatic latent image.

  The recording paper transport mechanism 4 feeds the recording paper in the paper feed cassette 8 and feeds the recording paper sent by the paper feed roller 41 to the photosensitive drum 31 at a predetermined timing. A conveyance belt 43 is provided for conveying the recording paper on which the toner image formed on the registration roller 42 and the photosensitive drum 31 is transferred and peeled off from the photosensitive drum 31 to the fixing roller 44. The transfer paper subjected to the fixing process by the fixing roller 44 is discharged onto a discharge tray through a discharge mechanism (not shown).

  A DC motor is used as the main drive motor described above, and in addition to the photosensitive drum 31, the registration roller 42, the transport belt 43, the fixing roller 44, and the like via the drive transmission mechanism such as a belt and a chain, A load that needs to transport the recording paper in synchronism with the peripheral speed is driven. The registration roller 42 is provided with an electromagnetic clutch in the drive unit, and is configured so that the drive can be controlled on and off.

  As shown in FIG. 2, the regenerative energy utilization device of the DC motor M includes a DC power supply circuit 2 that outputs a DC 24V DC voltage from a commercial AC power source that is stepped down via a transformer (not shown), and a DC power supply circuit 2 A motor driver circuit 7 for supplying a direct current to the armature of the DC motor M, and a control circuit 6 for controlling the current value supplied from the motor driver circuit 7 to control the start, stop, and rotation speed of the DC motor; The battery 5 is configured to store the generated power when the DC motor M is regeneratively braked by the control circuit, and the power amount counter 10 that detects the storage capacity of the battery 5.

  An output signal of an encoder that monitors the rotational speed of the DC motor is input to the control circuit 6 through output lines L3 and L4, and the electric motor of the DC motor M is input through the motor driver circuit 7 and the power supply lines L1 and L2. It is configured to supply power to the slave winding, and is configured to adjust the supply current via the motor driver circuit 7 so that the DC motor is driven to rotate at a predetermined constant speed based on the output pulse of the encoder. Yes.

  The DC motor M is stopped when the power supply from the motor driver circuit 7 is stopped by the control circuit 6, but after the power supply is stopped, the rotation operation is continued by the inertial force until it mechanically stops. Therefore, a capacitor 5 is provided for accumulating the generated power induced in the armature winding until the motor M stops, and is stored via the diode 4 each time the DC motor M is stopped. It is configured.

  When it is detected by the power amount counter 10 that a sufficient amount of power has been stored in the battery 5, the battery is received via the transistor 3 when the DC motor M is started by the control circuit 6 after receiving the signal. 5 is controlled to be supplied with a starting current. In other words, a transistor 3, a control circuit 6 that controls the transistor 3, and a stored power supply circuit that supplies power stored in the battery 5 by the power amount counter 10 when the DC motor M is started up are configured, and the DC motor is the most powered. The stored power is supplied at the start-up time to be consumed, and a large power saving effect can be obtained.

  Further, the control circuit 6 receives a power saving mode signal for identifying whether or not it is in the power saving mode from a system control unit (not shown). When it is detected that a sufficient amount of power has been stored, the transistor 9 is turned on to control the stored power to be supplied to another load 1 to which power is supplied from the DC power supply circuit 2.

  When it is detected by the power amount counter 10 that the storage capacity of the battery 5 has decreased, the transistor 9 is turned off, the battery 5 is disconnected, and control is switched so that power is supplied from the DC power supply circuit 2.

  Here, the other load 1 supplied in the power saving mode is, for example, display power supplied to the operation display unit 6, and a key input detection circuit that detects an input of a key arranged on the operation display unit 6. The load that is operating even in the power saving mode.

  In the above-described embodiment, the DC motor regenerative energy utilization device that stores electric power generated during regenerative braking of the main drive motor of the image forming apparatus has been described. However, the present invention is not used only in the image forming apparatus. The present invention can be provided to a device including a DC motor that drives a predetermined load.

Schematic configuration diagram of an image forming apparatus Circuit block diagram of DC motor regenerative energy utilization device

Explanation of symbols

2: DC power supply circuit 5: capacitor 6: control circuit 7: motor driver circuit 8: control circuit 10: electric energy counter M: DC motor

Claims (4)

A DC motor that drives a predetermined load; a control circuit that drives and controls the DC motor at a predetermined rotation speed; and a capacitor that stores electric power generated when the DC motor is regeneratively braked by the control circuit. A regenerative energy utilization device for a DC motor provided with a stored power supply circuit for supplying the electric power stored in the motor when the DC motor is started. The regenerative energy utilization apparatus for a DC motor according to claim 1, wherein the DC motor is a main drive motor of an electrophotographic image forming apparatus. The regenerative energy utilization apparatus for a DC motor according to claim 2, further comprising a stored power supply circuit that supplies power stored in the battery to another load mounted on the image forming apparatus. The regenerative energy utilization apparatus for a DC motor according to claim 2, further comprising: a stored power supply circuit that supplies power stored in the battery to a load in a power saving mode of the image forming apparatus.

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