JPH0792772A - Discharge wire fixing structure for corona discharger - Google Patents

Abstract

PURPOSE:To make it possible to easily and surely mount a discharge wire and simplify the work for demounting it when it is replaced. CONSTITUTION:The discharge wire fixing structure consists of a cylindrical member 31 provided with a fitting recessed portion 31a, plural elastic hook members 32 arranged around the fitting recessed portion 31a and provided with a first locking portion 42 elastically deformable in the direction apart from the fitting recessed portion 31a, and an engaging member 33 provided with a protrusion 35 fitted to the fitting recessed portion 31a so as to fix one end of a discharge wire 24 and the second locking portion 36 which can be locked to the first locking portion 42 in such a state that the protrusion 35 in engaged with the fitting recessed portion 31a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a discharge wire fixing structure,
In particular, the present invention relates to a discharge wire fixing structure for fixing one end of a discharge wire stretched on a corona discharger provided in an image forming apparatus such as a copying machine.

[0002]

2. Description of the Related Art Generally, in a copying machine or the like, an electrostatic latent image is formed on a photoconductor according to image information of an original, and the electrostatic latent image is visualized by a developing device to form a toner image, which is printed on a sheet. The toner image is transferred and the image information of the original is copied onto a sheet. In order to form an electrostatic latent image on a photoconductor, a process for charging the surface of the photoconductor to a constant potential is required as a pre-step. As this charging process,
A method using corona discharge (hereinafter referred to as corona charging) is generally used.

The corona discharger used for corona charging is
It has a shield case, a pair of insulating blocks supported at both ends of the shield case, and a discharge wire stretched in the shield case. One end of the discharge wire is fixed to one of the insulating blocks via a spring, the other end is fixed to the other of the insulating block, and tension is applied by the biasing force of the spring.

In order to fix the discharge wire in such a corona discharger, for example, Japanese Utility Model Laid-Open No. 63-15514.
The structure disclosed in Japanese Patent No. 6 is used. Here, a fitting recess is provided in the insulating block at the end of the shield case, and the discharge wire is locked by a locking member that fits into this fitting recess. The locking member is formed in a screw shape having a body and a head. The body has a guide portion of a predetermined width for guiding the discharge wire formed on the tip side, and an upper portion of the guide portion of the guide portion. A sandwiching portion having a gap smaller than the width is formed.

In this structure, the discharge wire is guided by the guide portion and is clamped by the clamp portion. Then, in this state, the locking member is press-fitted into the fitting recess, whereby the end portion of the discharge wire is fixed.

[0006]

The discharge wire in the corona discharger needs to be maintained at regular intervals, and must be replaced if the deterioration is severe. In the above-mentioned conventional structure, it is necessary to take out the locking member from the fitting recess in order to replace the discharge wire.
Once the locking member is fitted into the fitting recess, it is difficult to remove it. Therefore, maintenance work is difficult.

An object of the present invention is to provide a corona discharger,
The purpose of the present invention is to enable the discharge wire to be attached easily and surely, and also to facilitate the removal of the discharge wire when reattaching.

[0008]

The present invention comprises a fixing portion having a fitting recess, a plurality of elastic hook members, and an engaging member capable of engaging with and disengaging from the fitting recess. Each of the elastic hook members has a first locking portion and is elastically deformable in a direction away from the fitting recess. The engaging member is
A convex portion that engages with the fitting concave portion and fixes one end of the discharge wire together with the fitting concave portion, and a second locking portion that can be locked with the first locking portion while the convex portion is engaged with the fitting concave portion. And have.

The engaging member may have an abutting portion for abutting the first locking portion to deform the plurality of elastic hook members in a direction away from the fitting recess. Further, the abutment portion may be configured to elastically deform the first locking portion by rotating with the engagement member engaged with the fitting recess.

[0010]

In the discharge wire fixing structure of the corona discharger according to the present invention, one end of the discharge wire is fixed by engaging the convex portion of the engaging member with the fitting concave portion. At this time, the second engaging portion of the engaging member is engaged with the first engaging portion of the elastic hook member to fix the engaging member at a predetermined position.

When the discharge wire is replaced, the elastic hook member is elastically deformed in the direction away from the fitting recess to
The locking between the locking portion and the second locking portion is released. This allows the engaging member to be easily separated from the fitting recess. When the engaging member is provided with the abutting portion, when the engaging member is disengaged, the abutting portion deforms the plurality of elastic hook members in the direction away from the fitting recess.

By rotating the contact portion, the first
When the locking portion is configured to be elastically deformed, it is possible to easily disengage it from the fitting recess simply by rotating the engaging member.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a copying machine having a corona discharger in which an embodiment of the present invention is adopted. In the figure, an original placing table 2 is fixed to the upper surface of a copying machine main body 1.
A document retainer 3 is mounted on the document placing table 2 so as to be openable and closable. On the other hand, on the right side of the copying machine main body 1, paper feed cassettes 5 and 6 are detachably mounted, and on the left side, a paper discharge tray 7 for discharging the copied paper is mounted.

Inside the main body 1 of the copying machine, an optical system 8 for reading a document is provided above the main body. A photoconductor drum 9 is arranged substantially in the center of the apparatus main body 1. Around the photosensitive drum 9, a main charging corona discharger 10 for charging the photosensitive drum 9 to a predetermined charge, a developing device 11, a transfer corona discharger 12, a separation corona discharger 13, and a cleaning device 14 are provided. It is arranged.

Further, between the image forming section formed by the photosensitive drum 9 and the like and the sheet feeding cassettes 5 and 6, there is provided a sheet feeding device 15 for conveying the sheet to the image forming section. Further, a sheet conveying device 16 is provided on the downstream side of the image forming unit. A fixing device 18 for fixing the toner image on the conveyed sheet is provided between the sheet conveying device 16 and the discharge roller 17.

As shown in FIG. 2, the main charging corona discharger 20 includes a shield case 21 and a pair of front and rear first and first cases.
It has the second insulating blocks 22 and 23 and the discharge wire 24 stretched in the shield case 21. The shield case 21 has a U-shaped cross section and extends along the axial direction of the photosensitive drum 9. Space 25 of shield case 21
Discharge wires 24 are stretched inside, and insulating blocks 22 and 23 are supported at both ends. Both insulating blocks 22,
23 is formed in a box shape with an open upper part, and notches 22a, 2 through which the discharge wire 24 passes are formed on the opposite side walls.
3a is formed. Recess 2 of first insulating block 22
A boss 27 for mounting the discharge wire 24 is formed on the plate 6. The boss 27 has a spring 2 for tension adjustment.
One end of the discharge wire 24 is locked via 8. Also,
The recess 30 of the second insulating block 23 is provided with a discharge wire fixing structure according to an embodiment of the present invention.

The discharge wire fixing structure has a cylindrical member 31 formed in the recess 30 as a fixing portion having a fitting recess 31a and two elastic hook portions 32, 32. Then, the other end of the discharge wire 24 is held and fixed in the fitting recess 31a by an engaging member 33 that engages with the fitting recess 31a of the cylindrical member 31. As shown in an enlarged manner in FIGS. 3 and 4, the engaging member 33 has a columnar convex portion 35 that engages with the fitting concave portion 31 a, and a discharge wire is provided at the tip of the convex portion 35. A wire guide groove 35a for guiding is formed. On the upper portion of the convex portion 35, a columnar second locking portion 36 having a diameter larger than that of the convex portion 35 is provided. The second locking portion 36 is provided with the elastic hook member 3 described later.
The first locking portion 2 is locked. A grip portion 37 that is operated when the engagement member 33 is engaged with and disengaged from the fitting recess 31 a is provided further above the second locking portion 36.
The grip portion 37 has an elongated rhombus shape, and a short diagonal portion is shorter than a distance between the pair of opposing elastic hook portions 32, and a long diagonal portion is longer than a distance between the elastic hook portions 32. For this reason,
By rotating the engaging member 33, the end portion of the engaging member 33 contacts the elastic hook member 32, whereby the elastic hook member 32 is elastically deformed.

On the other hand, the fitting recess 31a of the cylindrical member 31 is
The inner diameter is set to be substantially the same as the outer diameter of the convex portion 35 of the engaging member 33. The elastic hook member 32 is arranged so as to face the circumference of the cylindrical member 31, and includes a base member 40, an elastic neck portion 41 extending upward from the base member 40, and a cylinder located above the elastic neck portion 41. It has the 1st latching part 42 which projected to the member 31 side. The first locking portion 42 has a substantially conical shape whose diameter increases from the upper side to the lower side, and the gap between the lower ends of the opposing first locking portions 42 is equal to that of the second locking portion 36 of the engaging member 33. It is smaller than the outer diameter, and the gap between the lower end surface of the first locking portion 42 and the upper end surface of the cylindrical member 31 is set to be substantially the same as the longitudinal length of the second locking portion 36.

Next, the attaching / detaching operation of the discharge wire will be described. When installing the discharge wire 24, the discharge wire 2
One end of 4 is attached to the spring 28, and this spring 28 is fixed to the boss 27 of the insulating block 22. Then, the discharge wire 24 is housed in the wire housing space 25 of the shield case 21 through the cutouts 22 a and 23 a of the insulating blocks 22 and 23. Next, the other end of the discharge wire 24 is locked in the wire guide groove 35a of the engaging member 33, and the convex portion 35 is engaged with the fitting concave portion 31a in this state.

At this time, the second locking portion 36 of the engaging member 33.
Thus, the first locking portion 42 of the elastic hook member 32 is pushed outward and the elastic neck portion 41 is elastically deformed outward. Further, the convex portion 35 fits into the fitting concave portion 31a. Then, when the lower end surface of the second locking portion 36 comes into contact with the upper surface of the cylindrical member 31, the elastic neck portion 41 returns to the original position, and the lower end surface of the first locking portion 42 of the second locking portion 36. Contact the top surface. In this state, the engagement member 33 is locked by the elastic hook member 32 while being engaged with the fitting recess 31a. At the same time, the discharge wire 24 has the convex portion 35 outer peripheral surface of the engaging member 33, the fitting concave portion 31 a inner peripheral surface, and the second locking portion 36 of the engaging member 33.
The lower surface and the upper surface of the cylindrical member 31 are sandwiched and securely mounted.

When the discharge wire 24 is replaced, the grip portion 37 of the engaging member 33 is held and rotated. As a result, both ends of the grip portion 37 spread the first locking portion 42 of the elastic hook member 32 and elastically deform the elastic neck portion 41 in a direction away from the fitting recess 31a. By deforming the elastic neck portion 41, the first locking portion 42 of the elastic hook member 32 is formed.
The engagement between the engagement member 33 and the second engagement portion 36 is released. In this state, the engaging member 33 is easily fitted into the fitting recess 31.
It can be pulled out from a.

After that, the old discharge wire may be removed and a new discharge wire may be attached as described above. According to this embodiment, the discharge wire 24 can be firmly fixed only by inserting the engaging member 33 into the fitting recess 31a. Also,
Even when the discharge wire is reattached, for example, when the gripping portion 37 of the engaging member 33 is rotated, the engaging member 33 is unlocked and can be easily operated with one hand.

[Other Embodiments] (a) The shape of the grip portion 37 of the engaging member 33 is not limited to the above embodiment. For example, the head portion of the screw member may have the same shape. In this case, the engaging member 33 is fitted into the fitting recess 3
When pulling out from the la 1a,
Is elastically deformed outward, and the engaging member 33 may be pulled out in this state.

(B) FIG. 5 is a front view of another embodiment.
The elastic hook member 50 has the same base member 51 and elastic neck portion 52 as described above. Further, the first locking portion 53 is formed on the elastic neck portion 52. First locking portion 53
Has an insertion guide surface 53a that bulges downward from the upper end toward the fitting recess 31a side, and a disengagement guide surface 53b that bulges upward from the lower end toward the fitting recess 31a side. The guide surface 53b at the time of disengagement also serves as a locking surface that contacts the upper surface of the second locking portion 36 of the engaging member 33.

In the embodiment having such a structure, when the engaging member 33 is inserted into the fitting concave portion 31a when the discharge wire 24 is attached, the second engaging portion 36 of the engaging member 33 becomes the first engaging portion. When inserting 53, the guide surface 53a is pushed to elastically deform the elastic neck portion 52. Engagement member 33 is fitted recess 31 to a predetermined position
When inserted in a, that is, when the second locking portion 36 passes through the guide surface 53a during insertion, the elastic neck portion 52 restores. Then, the guide surface 53b at the time of disengagement brings the second locking portion 36 into the locked state.

When the engaging member 33 is to be disengaged, the second engaging portion 3 is held by holding the grip portion 37 and pulling it upward.
6 pushes the guide surface 53b when the first locking portion 53 is disengaged, and elastically deforms the elastic neck portion 52. Therefore, in particular, the engaging member 3
It is possible to easily pull out the engaging member 33 without performing an operation such as rotating the member 3. In this embodiment, the engagement and disengagement of the engagement member 33 can be easily performed with one touch, so that the work of reattaching the discharge wire becomes easier.

[0027]

According to the present invention, in the corona discharger, the discharge wire can be easily attached only by engaging the engaging member with the fitting concave portion, and the elastic hook member is expanded to engage. The member can be easily pulled out from the fitting recess.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional configuration diagram of a copying machine to which an embodiment of the present invention is applied.

FIG. 2 is a partially exploded perspective view of a corona discharger provided in the copying machine.

FIG. 3 is a perspective view of a discharge wire fixing structure according to an embodiment of the present invention.

FIG. 4 is a front view of the fixing structure.

FIG. 5 is a front view of a discharge wire fixing structure according to another embodiment of the present invention.

[Explanation of symbols]

 24 Discharge Wire 33 Engagement Member 31a Fitting Recess 32 Elastic Hook Member 36 Second Locking Part 42 First Locking Part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toru Katamoto 1-2-2 Tamatsukuri, Chuo-ku, Osaka City Mita Industrial Co., Ltd. (72) Norimasa Kishigami 1-2-2 Tamatsukuri, Chuo-ku, Osaka City Mita Kogyo Co., Ltd. (72) Inventor Hiroshi Ito 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (72) Yasunori Ueno 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Business

Claims (3)

[Claims] 1. A discharge wire fixing structure for fixing one end of a discharge wire stretched to a corona discharger, comprising: a fixing portion having a fitting concave portion, and a fixing portion arranged around the fitting concave portion. A plurality of elastic hook members having one locking portion and elastically deformable in a direction in which the first locking portion is separated from the fitting recess; and the discharge wire together with the fitting recess to engage with the fitting recess. Has a convex portion for fixing one end of the concave portion, and a second locking portion that can be locked with the first locking portion in a state where the convex portion is engaged with the fitting concave portion. A discharge wire fixing structure for a corona discharger, comprising a mating and disengaging engagement member. 2. The engaging member has an abutting portion for abutting against the first locking portion and deforming the plurality of elastic hook members in a direction away from the fitting recess. Item 1
The structure for fixing the discharge wire of the corona discharger described in. 3. The abutment portion of the engaging member elastically deforms the first engaging portion by rotating in a state where the engaging member engages with the fitting recess. Fixing structure for discharge wire of corona discharger.