JPH11327266A - Wire cleaning device for electrifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and smoothly operate a wire cleaning device for an electrifier by using an inexpensive motor as a driving source. SOLUTION: This wire cleaning device is provided with a cleaning member holding tool 31 facing inside the shielding case 21 of and electrifier in which a discharge wire 22 is stretched and moving back and forth in a wire stretching direction, and a feeding means 36 for moving the tool 31 back and forth in the wire stretching direction. The tool 31 is provided with a cleaning member 32 which can slide in contact with the wire 22. The feeding means 36 is provided with a screw shaft 38 to be rotated in forward and reverse directions by a driving mechanism 37, a screw barrel 36 for locking on the tool 31 and screwed on the shaft 38, and a coil spring 42 inserted to be fit in non-screw parts 38a formed at both ends of the shaft 38, pushed and energized by the barrel 39 screwing and advancing to the part 38a and pressing the barrel 39 in an opposite direction to the screwing and advancing direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire cleaning device for a charger provided in an image forming apparatus such as an electrostatographic copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art For example, in an electrostatographic copying machine, a photoreceptor is used for main charging of a drum surface, transfer of a toner image to an image recording sheet, separation of the sheet from the drum surface, and elimination of residual charges on the drum surface. A charger is placed around the drum.

[0003] Among them, as a charger for main charging, for example, a charger of a type in which a discharge wire is stretched along a longitudinal direction of a case in a shield case in which an opening for discharge is formed, or a discharge wire other than the above. There is a so-called scorotron type charger in which a plurality of grid wires are stretched.

In any of these types of chargers,
A wire cleaning device is provided to prevent the toner or paper powder from adhering to the wire and preventing proper corona discharge from being obtained.

[0005] For example, as a wire cleaning device for a charger of a type in which only discharge wires are stretched, a shield case in which discharge wires are stretched along the longitudinal direction of the case,
A slider held by the shield case so as to be able to reciprocate in the wire extending direction, a cleaning member holder provided on the slider, and a feeding means for reciprocating the cleaning member holder together with the slider in the wire extending direction. Some are provided with

[0006] In this case, the feeding means has, for example, a helical shaft arranged in a wire extending direction, a helical cylinder engaged with the cleaning member holder is screwed to the helical shaft, and the helical shaft is rotated by a motor. It is configured to rotate in reverse. With this configuration, the cleaning member holder moves forward and backward by the forward and reverse rotation of the spiral shaft, and the discharge wire is cleaned by the cleaning holder provided on the cleaning member holder.

[0007]

However, in the above configuration, a high-precision pulse motor is used as a motor for rotating the helical shaft in the forward and reverse directions in order to accurately stop the cleaning member holder at the home position or the turning position. However, there is a problem that the cost is high. When the direction of the helical tube is changed, the helical tube in the non-helical portion of the helical shaft may not be able to smoothly screw into the helical portion, and there is a problem that the wire cleaning device is likely to malfunction.

In view of the above-mentioned conventional drawbacks, the present invention provides a wire cleaning device for a charger which can operate accurately and smoothly using an inexpensive motor as a driving source. .

[0009]

In order to achieve the above object, a first aspect of the present invention provides a cleaning member which faces at least a shield case of a charger on which a discharge wire is stretched and which can reciprocate in a wire stretching direction. A wire for a charging device, comprising: a holding unit; a cleaning member provided on the cleaning member holding unit, the cleaning member being slidable at least against the discharge wire; and a feeding unit for reciprocating the cleaning member holding unit in a wire extending direction. In the cleaning device, the feed unit includes a helical shaft that is rotationally driven by a rotary drive mechanism in a forward and reverse direction, a female screw member that is engaged with the cleaning member holding unit and is screwed to the helical shaft, A spring member provided on a non-spiral portion formed at both ends and being pushed by the female screw member screwed into the non-spiral portion to accumulate and bias the female screw member in a direction opposite to the screwing direction; Also have It is characterized in that was. According to this configuration, even when an inexpensive motor with inferior precision is used as the motor of the rotary drive mechanism, when the female screw member reaches the non-spiral portion at the end of the helical shaft, the female screw member stops properly at this position. become. Further, at this position, the spring member is pressed by the female screw member, and the female screw member is urged in the opposite direction by the spring member and pressed against the spiral portion of the helical shaft. At the start of the movement, the female screw member is securely screwed into the helical portion of the helical shaft, so that the movement of the wire cleaning device from the home position can be started and the turning operation at the turning position can be performed smoothly and reliably. it can.

In the second invention, a slider is provided on the shield case so as to be slidable in the wire extending direction, and the cleaning member holding means is swingably supported on the slider, so that the cleaning member holding means can reciprocate. It is characterized in that the switching of the cleaning member holding means between the cleaning posture and the cleaning release posture is regulated by the slider in response thereto. According to this configuration, the cleaning member holder can be switched between the cleaning posture and the cleaning release posture in accordance with the forward and backward movements of the wire cleaning device.

A third aspect of the present invention is characterized in that the charger is a scorotron type in which a grid wire in addition to the discharge wire is stretched in the same direction as the discharge wire in the shield case. According to this configuration, even when a scorotron type charger is targeted, the discharge wire can be cleaned smoothly and reliably.

In the fourth invention, the cleaning member holding means includes:
It is characterized in that a cleaning member for the grid wire is provided in addition to the cleaning member for the discharge wire. According to this configuration, in the case of a scorotron-type charger, not only the discharge wire but also the grid wire can be smoothly and reliably cleaned.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 show a cross-sectional view and an external perspective view of an image forming apparatus equipped with a wire cleaning device for a charger of this embodiment. The image forming apparatus 1 is an electrostatographic copying machine having a full-color copying function, and is configured by mounting a copying machine main body 3 on a paper feeding desk 2.

The paper supply desk 2 includes a plurality of paper supply cassettes 4 provided so as to be able to be inserted into and removed from the front surface, and a combined conveyance path 5 for papers fed and fed from these paper supply cassettes 4. . The copying machine main body 3 includes an image forming unit 7 including a photosensitive drum 6 and the like, and a sheet feeding unit 9 that conveys a sheet fed from the merged conveyance path 5 and the manual feed table 8 to an image forming unit of the image forming unit 7. A paper feed path 11 for feeding the sheet after image formation to the fixing device 10; and a sheet discharge path 13 for discharging the sheet after fixing to the sheet discharge tray 12.

The above-described image forming unit 7 converts a scorotron type charger 14 for main charging and image reading information from an optical device 15 around a photosensitive drum 6 laid across the copying machine body 3. An exposure device 16 for forming a latent image on the surface of the drum based on the developing device, and a developing device for accommodating cyan, yellow, magenta, and black toners separately to visualize the latent image formed on the drum surface 17, a transfer / separation unit 18 for transferring the toner image to the paper and separating the paper, a cleaning device 19, and a static eliminator 2
0.

The above charger 14 is, as shown in FIG.
It has a shield case 21 in which an opening for discharging is formed.
A discharge wire 22 is stretched along the axial direction of the shield case 21), and a grid wire 23 is stretched along the longitudinal direction of the case at the discharge opening of the shield case 21.

The wire cleaning device 24 for cleaning the discharge wire 22 is configured as shown in FIGS. That is, a long hole 26 is formed in the bottom plate 25 of the shield case 21 in the wire extending direction, and the slider 28 is held so as to be able to reciprocate with the edges on both sides of the long hole 26 as guide rails 27.

The slider 28 is provided with a pair of shaft supports 29, 29 whose axes are orthogonal to the direction in which the wires are extended. Further, the slider 28 is provided with stoppers 30a, 30b on both sides in the direction in which the wires are extended. Are formed. The cleaning member holder 31 is a member that holds the cleaning member 32 of the discharge wire 22, and includes a shaft 33, a U-shaped member 34 suspended from the shaft 33, and an intermediate position between the shaft 33. A cleaning member 32 is provided at a lower end of the U-shaped member 34. In this cleaning member holder 31, both ends of the shaft body 33 are pivotally attached to the shaft supports 29, 29 of the slider 28 in a state where the lever 35 is inserted through the penetrating portion 30 of the slider 28.

The feeding means 36 of the wire cleaning device 24 includes a helical shaft 38 which is driven to rotate forward and backward by a rotation driving mechanism 37,
A helical cylinder 39 which is a female screw member screwed to the helical shaft 38
And The spiral shaft 38 is arranged outside the shield case 21 along the wire extending direction, and both ends thereof are rotatably supported by a pair of shaft supports 40, 40. A portion of a predetermined length near the center from a position supported by the shaft supports 40 at both ends of the spiral shaft 38 is a non-spiral portion 38 having no spiral.
The spiral cylinder 39 is in a loosely fitted state in the non-spiral portion 38a. That is, the outer diameter of the non-spiral portion 38 a is formed slightly smaller than the minimum inner diameter of the spiral cylinder 39. Further, the spiral tube 3 is provided in both non-spiral portions 38a.
9 and the coil spring 42 are connected to the seat plate 4.
1 and the shaft support member 40 are inserted so as to sandwich the coil spring 42 therebetween.

On the outer side of the helical cylinder 39, locking members 43, 44 for locking with the lever 35 of the cleaning member holder 31 are protruded. The rotation drive mechanism 37 includes a drive motor 45 capable of normal and reverse rotation, and a rotation output of the drive motor 45,
8 and gears 46 and 47 for transmitting the gears.

The right part of FIG. 6A shows a state where the cleaning member holder 31 of the wire cleaning device 24 is waiting at the home position. At this time, the spiral cylinder 39 constituting the feeding means 36 is in a state of being loosely fitted to the non-spiral portion 38a at one end of the spiral shaft 38, and is urged in the X direction by the compressed coil spring 42. That is, the spiral cylinder 39 is in a state of being pressed against the end of the spiral portion of the spiral shaft 38. Therefore, when the helical shaft 38 is driven to rotate in the forward rotation direction, the helical cylinder 39 is securely screwed into the helical portion of the helical shaft 38, and the wire cleaning device 2 from the home position is rotated.
4 is smoothly started.

Further, as shown in the right part of FIG. 6B, when the spiral cylinder 39 is moved forward in the X direction, the spiral cylinder 3
9, the lever 35 of the cleaning member holder 31 is locked to the locking body 43 at the rear in the screwing direction, and the lever 35 is
The cleaning member holder 31 rotates around the shaft 33 until the stopper 30b contacts the stopper 30b. By the rotation of the lever 35, the posture of the cleaning member holder 31 is switched to a wire cleaning posture in which the cleaning member 32 slides on the discharge wire 22, and the slider 28 is moved in the X direction with the forward movement of the spiral tube 39. The discharge wire 22 is moved to the cleaning member 3.
2 will be cleaned.

As shown in the left part of FIG. 6B, the spiral cylinder 39 has a non-spiral portion 38a which is the end of the spiral shaft 38 in the X direction.
When the helical tube 39 is screwed forward, the helical tube 39 is loosely fitted to the non-spiral portion 38a. Therefore, even if the helical shaft 38 is continuously driven to rotate in the same helical direction, the helical tube 39 is correctly stopped at the X direction end position. I do. That is, even if an inexpensive and inexpensive motor is used as the drive motor 45 of the rotation drive mechanism 37,
The cleaning member holder 31 of the wire cleaning device 24 can be properly stopped at the direction change position. In this state, the coil spring 42 inserted into the non-spiral portion 38a is
It is pushed by the helical cylinder 39 via 1 and compressed.

At the stop position, the spiral cylinder 39 is urged in the Y direction opposite to the X direction by the compressed coil spring 42, so that the spiral cylinder 39 is pressed against the end of the spiral portion of the spiral shaft 38. is there. For this reason, when the rotation of the spiral shaft 38 is switched to the rotation reverse to that in the forward movement, the spiral tube 39 is securely screwed into the spiral portion of the spiral shaft 38, and thereafter, the spiral tube 39
Starts the backward screwing in the Y direction as shown in the left part of FIG. By the start of the return screw advance, the spiral cylinder 3
9, the lever 35 of the cleaning member holder 31 is locked to the locking body 44 at the rear in the screwing direction, and the lever 35 is
The cleaning member holder 31 rotates around the shaft 33 until the stopper 30a contacts the stopper 30a. By the rotation of the lever 35, the posture of the cleaning member holder 31 is switched to the cleaning release posture in which the cleaning member 32 is separated from the discharge wire 22. When the spiral cylinder 39 moves backward in this posture, the cleaning member holder 31 is sent to the end in the Y direction.

When the spiral tube 39 is screwed up to the non-spiral portion 38a, which is the terminal in the Y direction of the spiral shaft 38, the spiral tube 39 is loosely fitted to the non-spiral portion 38a, as in the operation at the terminal in the X direction. Therefore, even if the helical shaft 38 is continuously driven to rotate in the same advancing direction, the helical cylinder 39 correctly stops at the end position in the Y direction. That is, the cleaning member holder 31 of the wire cleaning device 24 can be properly stopped at the home position even if an inexpensive motor with low precision is used as the drive motor 45 of the rotation drive mechanism 37. In this state, the coil spring 42 inserted into the non-spiral portion 38a is pressed by the helical cylinder 39 via the seat plate 41 and compressed.

In the above embodiment, the discharge wire 22
Although the configuration example in which only the cleaning is performed is shown, a cleaning member for the grid wire 23 may be provided in the cleaning member holder 31 in addition to the cleaning member 32 for the discharge wire 22.

In the above-described embodiment, the case where the scorotron type charger is used has been described. However, the present invention can be similarly applied to a case where a wire cleaning device is used for a charger provided with only discharge wires.

[0028]

The present invention is configured as described above.
The following effects are obtained. According to the first aspect of the present invention, even when an inexpensive motor with low precision is used as the motor of the rotary drive mechanism, when the female screw member reaches the non-spiral portion at the end of the helical shaft, the female screw member stops correctly at this position. Will do. Further, at this position, the spring member is pressed by the female screw member, and the female screw member is urged in the opposite direction by the spring member and pressed against the spiral portion of the helical shaft. At the start of the movement, the female screw member is securely screwed into the helical portion of the helical shaft, so that the movement of the wire cleaning device from the home position can be started and the turning operation at the turning position can be performed smoothly and reliably. it can.

According to the second aspect of the present invention, the cleaning member holder can be switched between the cleaning position and the cleaning release position according to the forward and backward movements of the wire cleaning device.

According to the third aspect of the present invention, even when a scorotron-type charger is used, the discharge wire can be cleaned smoothly and reliably.

According to the fourth aspect of the present invention, in the case of a scorotron type charger, not only the discharge wire but also the grid wire can be cleaned smoothly and reliably.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an image forming apparatus equipped with a wire cleaning device for a charger according to an embodiment of the present invention.

FIG. 2 is an external perspective view of the image forming apparatus.

FIG. 3 is a side sectional view of a wire cleaning device of a charger provided in the image forming apparatus.

FIG. 4 is a front view of the wire cleaning device.

FIG. 5 is an exploded perspective view showing a main part of the wire cleaning device.

FIG. 6 is an operation explanatory view of the wire cleaning device.

[Description of Signs] 14 ... Charger, 21 ... Shield case, 22 ... Discharge wire, 23 ... Grid wire, 24 ... Wire cleaning device, 2
Reference numeral 8: slider, 31: cleaning member holder, 32: cleaning member, 36: feeding means, 37: rotary drive mechanism, 38: spiral shaft, 38a: non-spiral portion, 39: spiral cylinder (female screw member),
42 ... Coil spring (spring member)

Claims (4)

[Claims] 1. A cleaning member holding means which faces at least a shield case of a charger on which a discharge wire is stretched and which can reciprocate in a wire stretching direction; and a cleaning member holding means provided on the cleaning member holding means; A wire cleaning device for a charger, comprising: a cleaning member capable of sliding contact; and a feeding unit for reciprocating the cleaning member holding unit in a wire stretching direction, wherein the feeding unit is driven by a rotation driving mechanism in a reverse direction. A helical shaft that is driven to rotate, a female screw member that engages with the helical shaft while being engaged with the cleaning member holding unit, and a non-spiral portion formed at both ends of the helical shaft,
A spring member that is pushed by the female screw member screwed into the non-spiral portion to accumulate and urge the female screw member in a direction opposite to the screwing direction. 2. A shield is provided on the shield case so as to be slidable in a wire extending direction, and the cleaning member holding means is swingably supported by the slider, and in response to a reciprocating operation of the cleaning member holding means. 2. The wire cleaning device for a charger according to claim 1, wherein the cleaning member holding means is controlled by the slider to switch between a cleaning posture and a cleaning release posture. 3. A scorotron type charger in which a grid wire is stretched in the shield case in the same direction as the discharge wire, in addition to the discharge wire, in the shield case. 4. The wire cleaning device for a charger according to claim 1. 4. The wire cleaning device for a charger according to claim 3, wherein the cleaning member holding means is provided with a cleaning member for the grid wire in addition to the cleaning member for the discharge wire. .