JPH08262926A - Earth plate structure of photoreceptor drum - Google Patents

Abstract

PURPOSE: To provide the earth plate structure of a photoreceptor drum capable of completely preventing the winding of the contact piece of an earth plate, for attaining safe and sure grounding and reducing the cost, without adversely affecting the drum. CONSTITUTION: The earth plate 1 fixed on a flange 7 fitted into the side end of the drum 6 of the photoreceptor drum 5 is composed of a fixing plate 2 which is fixed on the side surface of the fitting side of the flange 7 and provided with a brush 9, a flexible plate 3 which is bent from the periphery of the plate 2 and extended in the axial direction of the drum 6 and the contact piece 4 bent into a case shape on the extended end of the flexible plate 3. The circular arcuate abutting part, 16 of the contact piece 4 comes into contact with the inside surface of the drum 6, to bend the plate 3 inward and prevent the winding of the contact piece 4. The abutting part 16 comes into contact with the inside surface of the drum 6, to fulfill a grounding function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground plate structure of a photosensitive drum provided in a photosensitive section of a copying machine, a printer, a fax machine, etc., and in particular, it can be manufactured at a low cost without involving the drum side. The present invention relates to a ground plate structure for a photosensitive drum.

[0002]

2. Description of the Related Art As shown in FIG. 15, a flange 7 is fitted in the opening of a drum 6 and the ground plate 1 is attached to the flange 7.
f is fixed. The ground plate 1f contacts the inner surface of the drum 6 to perform drum grounding. Conventionally, as shown in FIG. 13, an earth plate 1f which is used relatively often is adopted. This is a fixing plate 2f fixed to the end surface of the fitting side of the flange 7, a flexible plate 3f bent and extending from the outer edge thereof, and a curl-shaped contact piece formed at the extending end of the flexible plate 3f. Formed from 40.

The contact piece 40 is formed by bending the extension end of the flexible plate 3f in an arc shape.
It has the same width dimension b as f. The fixing plate 2f has a brush 9 connected to the ground side of the device.
f is formed to be bendable. As shown in FIG. 14, the ground plate 1 f is fixed to the flange 7 in advance, and the ground plate 1 f is fitted into the opening of the drum 6.

Since the outer end of the curled contact piece 40 of the ground plate 1f is larger than the inner diameter of the drum 6, the contact piece 40 is pressed against the inner surface of the drum 6 as the flange 7 is fitted. Therefore, the flexible plate 3f is inclined downward, and the state shown in FIG. 15 is obtained. The drum grounding is performed as described above.

As one of the known techniques for drum grounding, there is one disclosed in Japanese Utility Model Laid-Open No. 1-166376. This "ground flange mounting structure on the photoconductor drum"
Has a structure in which a claw piece projecting outwardly from the peripheral edge of the earth plate is provided, and the claw piece is bited into the drum to be grounded.

[0006]

In the case of the conventional ground plate 1f shown in FIG. 13, the flexible plate 3 is used as described above.
A curled contact piece 40 having the same width as f contacts the inner surface of the drum 6. In this case, if the plate thickness t of the flexible plate 3f is too thin, the pressing force acting on the contact piece 40 causes the flexible plate 3f to largely bend. Therefore, the contact piece 40 is not pressed against the inner surface of the drum 6, and the earth effect is reduced.

On the other hand, when the plate thickness t is increased, the pressure contact force becomes large and a convex portion is formed on the surface of the drum 6. Therefore, in order to stably exert the earth effect by the earth plate 1f, it is necessary to form the size and shape of each part of the earth plate 1f with high accuracy, and also to fix the flange 7 to the flange 7 with high accuracy. is there. Further, since the contact piece 40 has the same width dimension b as that of the flexible plate 3f as described above, the total area of the ground plate 1f in the unfolded state of the contact piece 40 becomes considerably large.

Further, as shown in FIG. 16, in the case of the earth plate 1f having the above-mentioned structure, the contact piece 40 and the contact piece 40 are provided when the accuracy of the above-mentioned size and shape is not maintained or the accuracy of mounting on the flange 7 is insufficient. The contact piece 40 is generated by the frictional force between the inner surface of the drum 6 and
The curled shape of the contact piece 40 is deformed, as shown in FIG.
May be sandwiched between the inner surface of the drum 6 and the fitting portion of the flange 7. Therefore, the drum 6 is pushed up from the inside, and the convex portion 20 is formed on the surface of the drum 6.

In Japanese Utility Model Laid-Open No. 1-166376, a small claw piece is pressed against the inner surface of the drum to provide a grounding effect, but the claw piece locally presses the inner surface of the drum. Therefore, when the dimensional control of the claw pieces is insufficient, there is a problem that the surface of the drum is adversely affected as in the above-mentioned conventional technique.

The present invention solves the above-mentioned problems. The drum grounding is reliably and stably performed, the winding of the contact piece is completely prevented, the development area of the grounding plate is small, and the cost is low. An object of the present invention is to provide a ground plate structure for a photoconductor drum that can be reduced.

[0011]

In order to achieve the above object, a ground plate structure for a photosensitive drum according to a first aspect of the present invention includes a hollow cylindrical drum having openings at both ends thereof,
The earth plate structure in a photoconductor drum, comprising: a flange fitted into the opening; and a ground plate having a contact piece fixed to the flange and abutting against an inner surface of the drum when the flange is fitted, The earth plate is a fixing plate having a brush fixed to the end surface of the flange on the fitting side and engaging with the earth side; and a flange extending from the outer edge of the fixing plate and extending substantially along the axial direction of the drum. Of the flexible plate, at least the tip side of which is housed in a notched groove that is recessed in the fitting side of the flexible plate, and the contact piece that is bent in a box shape at substantially right angles from the extended end of the flexible plate. The contact piece is surrounded by a contact portion that contacts the inner surface of the drum, a bent line portion of the contact piece, and a rising portion that connects the bent line portion and the end portion of the contact portion. Characterized by comprising the ones of the claw-shaped.

According to a second aspect of the present invention, the grounding plate structure of the photosensitive drum is characterized in that the contact portion of the contact piece is formed by an arc-shaped, polygonal-shaped, or linear contour line.

According to a third aspect of the present invention, in the ground plate structure for a photosensitive drum, an intersection angle β between the rising portion of the contact piece and the flexible plate on the surface of the contact piece is at least 90.
It is characterized by being ° or higher.

According to a fourth aspect of the present invention, in the ground plate structure for a photosensitive drum, at least the base end side of the rising portion having an intersection angle β exceeding 90 ° abuts and engages with the bottom surface of the cutout groove of the flange. Is characterized in that.

According to a fifth aspect of the present invention, the ground plate structure for the photosensitive drum is characterized in that an inwardly intersecting angle α between the flexible plate and the fixing plate is 90 ° or 90 ° or less.

According to a sixth aspect of the present invention, there is provided a grounding plate structure for a photosensitive drum, wherein a narrow portion is formed at the flexible plate and / or a connecting portion between the flexible plate and the fixing plate. To do.

[0017]

The contact piece is made of a claw piece having a thin plate thickness and bent in a box shape. When the flange is fitted into the drum, the inner surface of the drum comes into contact with the contact portion of the claw piece contact piece. Since the contact portion has an arcuate contour and the intersection angle α of the base end side of the flexible plate is 90 ° or less, the contact between the contact portion and the inner surface of the drum causes the flexible plate to move inward (to the drum's inner surface). Tilt toward the center). Therefore, unlike the prior art, the involvement does not occur. Further, since it is not necessary to prevent the contact portion from being deformed by the plate thickness of the contact piece itself against the pressing force acting on the contact piece, the plate thickness itself can be made thin. Therefore, the soft contact of the contact piece to the inner surface of the drum can be easily performed with ease. This prevents adverse effects on the drum surface.

Further, the crossing angle β of the rising portion of the contact piece is set to 9
The strength of the contact piece can be increased by setting the angle to 0 ° or more, and the proximal end side of the rising portion is brought into contact with the bottom surface of the cutout groove to facilitate the inward deformation of the flexible plate and wrap it up. Can be completely prevented.
Further, by setting the intersection angle α of the flexible plate to 90 ° or less and providing the narrow portion at the connecting portion with the fixing plate, it is possible to more easily deform the flexible plate inward.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axial sectional view showing the overall structure of a photosensitive drum provided with a ground plate of this embodiment, FIG. 2 is a perspective view showing the shape of the ground plate of this embodiment, and FIG. 3 is a ground plate of this embodiment. FIG. 4 is a partial side view showing the shape around the contact piece, and FIG. 4 is a partial plan view showing a developed state of the ground plate of the present embodiment.

FIG. 5 is a partial axial sectional view showing the engagement state with the drum when the flange provided with the ground plate of this embodiment is fitted,
FIG. 6 is a partial axial sectional view showing the engagement state of the ground plate and the drum when the fitting of the flange provided with the ground plate of this embodiment is completed, and FIGS. 7 (a) and 7 (b) are other embodiments of the present invention. FIG. 8 is a partial perspective view showing an example of the shape around the contact piece, and FIG. 8 is a partial axial sectional view for explaining the problem at the time of fitting the earth plate.

FIG. 9 is a partial perspective view showing a grounding plate having a contact piece which solves the above problems, and FIG. 10 is a partial axial sectional view for explaining the action when the grounding plate of FIG. 9 is fitted.
12A and 12B are a partial perspective view showing a ground plate of still another embodiment of the present invention, and FIGS. 12A and 12B are a partial perspective view and a developed plan view of a ground plate of still another embodiment.

First, the overall structure of the ground plate 1 according to one embodiment of the present invention will be described with reference to FIG. The ground plate 1 is composed of a fixing plate 2, a flexible plate 3 that is bent from the outer edge of the flexible plate 3 and extends, and contact pieces 4 and 4 that are bent in a box shape at right angles from the extended end of the flexible plate 3.

On the other hand, as shown in FIG.
The photosensitive drum 5 to be mounted is a hollow cylindrical drum 6 having openings at both ends, flanges 7 and 8 fitted in the openings, a ground plate 1 fixed to the flange 7 side, and the like. Consists of. The fixing plate 2 of the ground plate 1 has a brush 9 at the center thereof and has mounting holes 10 and 11 formed therein. The ground plate 1 is fixed to the side end surface of the flange 7 on the fitting side by the mounting holes 10 and 11, as shown in FIG.

The brush 9 is bent and formed as shown in FIG. 1, and the brush 9 is connected to the ground side of the apparatus by means not shown. As shown in FIG. 2, the ground plate 1 has a plate thickness t.
1 is formed by bending a flat plate having a width b (excluding the area around the brush 9 at the center), and as shown in FIG. 1, the intersection of the fixing plate 2 and the flexible plate 3 is an inner hole on the fitting side of the flange 7. Is arranged at a position corresponding to the outer edge of the bottom surface of the.

The flexible plate 3 extends substantially along the inner circumference of the inner hole and along the axial direction of the drum 6, and the contact piece 4
The tip side of the flexible plate 3 in the vicinity of the groove is housed in the notch groove 12 of the flange 7 and the notch groove 12 is formed.
Is guided in the width direction.

As shown in FIG. 4, the contact piece 4 and the flexible plate 3 are formed by bending a flat plate having a developed contour shape in which claw pieces 13 having a shape corresponding to the contact piece 4 are formed on the tip side of the flat plate having the width b. It is formed by bending the line portions 14, 14 and 15. As shown in FIGS. 3 and 4, the claw-shaped contact piece 4 has a contact portion 16, the bent line portion 14, and a rising portion 17 that connects the respective end portions of the contact portion 16 and the bent line portion 14. It consists of claw pieces surrounded by and.

As shown in FIG. 3, the angle of intersection between the rising portion 17 of the contact piece 4 and the flexible plate 3 on the surface of the contact piece 4 is β, and the bending line portion of the flexible plate 3 and the fixing plate 2 is defined as β. The intersection angle at 15 is α. In this embodiment, both the crossing angles β and α are 90 °. Further, in this embodiment, the contact portion 16 has an arcuate contour. Further, as shown in FIG. 5, in the free state before fitting in which the ground plate 1 is fixed to the flange 7, the outer end side of the abutting portion 16 of the contact piece 4 is at least a position protruding outward from the inner surface of the drum 6. It is formed to come to.

As shown in FIG. 5, when the flange 7 to which the ground plate 1 is fixed is engaged with the opening of the drum 6, the contact piece 4 is formed.
The abutting portion 16 of the abuts against the edge of the inner hole of the drum 6 on the opening side. By pressing the flange 7 in the fitting direction, the pressing force F acts on the contact portion 16.

Since the intersection angle α of the flexible plate 3 is 90 °,
As the flange 7 is fitted, the flexible plate 3 is inclined inward, and the contact portion 16 contacts the inner surface of the drum 6 as shown in FIG. The contact piece 4 is made of a claw piece having a plate thickness t as described above, the contact area between the contact portion 16 and the inner surface of the drum 6 is small, and the frictional force at the time of fitting is small.

As described above, the contact piece 4 is never caught between the drum 6 and the flange 7. Further, although the contact piece 4 and the inner surface of the drum 6 are in contact with each other in a small area, they are sufficiently contacted to fulfill the ground function. However, since the pressing force is small, there is no adverse effect on the surface side of the drum 6.

7 (a) and 7 (b) show ground plates 1a, 1b having contact pieces 4a, 4b having a different shape from the contact piece 4 of the ground plate 1 described above. The ground plates 1a and 1b are different from each other only in the contour shape of the contact portions 16a and 16b of the contact pieces 4a and 4b, and the other parts are the same as the ground plate 1 of the above-mentioned embodiment.

The contact portion 16a of the ground plate 1a shown in FIG. 7 (a)
Is a polygonal shape, and FIG. 7B is a linear shape. In any case, the same operational effect as that of the above-mentioned embodiment is obtained. The shape of the contact portion is not limited to the contact portion 16 and the contact portions 16a and 16b shown in FIG. 7, and other contour shapes may be adopted.

In the case of the ground plates 1, 1a, 1b of the above-mentioned embodiment, the rising portions 17, 1 of the contact pieces 4, 4a, 4b.
Since the intersection angle β of 7a, 17b, etc. is 90 °, the problem shown in FIG. 8 tends to occur. That is, when the pressing force F acts when the flange 7 is fitted, the pressing force F concentrates at the intersection A between the rising portion 17 and the flexible plate 3, and only the contact piece 4 is locally deformed. To do.

FIG. 9 shows an embodiment for solving this problem. The contact piece 4c of the ground plate 1c of FIG. 9 is shown in FIG.
As also shown in FIG. 6, the intersection angle β between the rising portion 17c and the flexible plate 3 is 90 ° or more, and the base end portion (shown by point B) of the rising portion 17c on the flexible plate 3 side is the flange 7.
The cutout groove 12 is formed so as to come into contact with the bottom surface 18 of the cutout groove 12.

From the above, the concentration force at the point B due to the pressing force F is eliminated, and the rising portion 17c is inclined so that the bottom surface 1
Since it is supported by 8, the flexible plate 3 is smoothly deformed inward. As described above, the flange 7 is smoothly fitted, and the contact piece 4c is not locally deformed.

FIG. 11 shows a ground plate 1d according to still another embodiment of the present invention. The earth plate 1d has an intersection angle α between the flexible plate 3 and the fixing plate 2 of 90 ° or less. Of course, the shape of the contact piece 4d in this case may be any of those in the above-mentioned embodiments. By setting the intersecting angle α to 90 ° or less, the inward deformation of the flexible plate 3 can be performed more smoothly and reasonably.

12 (a) and 12 (b) show a ground plate 1e according to another embodiment of the present invention. This earth plate 1e
Is composed of a flexible plate 3 and a narrow portion 19 formed at a connecting portion between the flexible plate 3 and the fixing plate 2. By forming the narrow portion 19, the flexible plate 3 is more easily deformed inward. The shape of the contact piece 4e in this embodiment may be any of those in the above embodiments, and the intersection angle α may be 90 ° or 90 ° or less.

[0038]

According to the present invention, the following remarkable effects are obtained. 1) The contact piece of the ground plate has a box-like bent claw piece shape, and the contact portion is pressed against the inner surface of the drum, so that the winding between the drum and the flange is completely eliminated. can do. 2) Since the abutting portion of the contact piece is reliably pressed against the inner surface of the drum, the grounding effect can be secured. 3) Unlike the conventional method in which the pressing force from the drum side is received only by the thickness and width of the ground plate, the contact piece bent into a box shape can receive the pressing force sufficiently even if the plate thickness is thin. it can. 4) By adopting a structure in which the crossing angle β on the rising side of the contact piece is 90 ° or more and the base end side of the rising side is in contact with the bottom surface of the cutout groove of the drum, The deformation to one side is made easier, and the entrainment is more completely prevented. 5) By setting the intersection angle α of the flexible plates to 90 ° or less, the inward tilting of the flexible plates can be facilitated. 6) By forming the narrow portion on the base end side of the flexible plate, the flexible plate can be more easily inwardly collapsed, thereby completely preventing entrainment.

[Brief description of drawings]

FIG. 1 is an axial sectional view showing the overall structure of a photosensitive drum provided with a ground plate according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the shape of a ground plate of this embodiment.

FIG. 3 is a partial side view showing the shape around the contact piece of the ground plate of the present embodiment.

FIG. 4 is a partial plan view showing a developed state of the ground plate of the present embodiment.

FIG. 5 is a partial axial sectional view showing an engaged state with the drum when the flange provided with the ground plate of the present embodiment is fitted.

FIG. 6 is a partial axial cross-sectional view showing the engagement state of the ground plate and the drum when the fitting of the flange provided with the ground plate of the present embodiment is completed.

FIG. 7 (a) is a partial perspective view of another embodiment of the ground plate of the present invention, and FIG. 7 (b) is a partial perspective view showing another embodiment of the ground plate.

FIG. 8 is a partial axial sectional view for explaining a problem when the ground plate of the embodiment is fitted.

9 is a partial perspective view showing another embodiment of the present invention which solves the problem of the ground plate shown in FIG.

FIG. 10 is a partial axial cross-sectional view for explaining the action when the ground plate of FIG. 9 is fitted.

FIG. 11 is a partial perspective view showing still another embodiment of the ground plate of the present invention.

12A is a partial perspective view showing another embodiment of the ground plate of the present invention, and FIG. 12B is a development view thereof.

FIG. 13 is a perspective view showing an example of a conventional ground plate.

FIG. 14 is a partial axial cross-sectional view showing a state before fitting a flange provided with a conventional ground plate.

15 is a partial axial cross-sectional view showing a correct engagement state of the ground plate shown in FIG. 13 with a drum.

16 is a partial axial sectional view for explaining a problem of the ground plate shown in FIG.

[Explanation of symbols]

 1 earth plate 1a earth plate 1b earth plate 1c earth plate 1d earth plate 1e earth plate 1f earth plate 2 fixing plate 2f fixing plate 3 flexible plate 3f flexible plate 4 contact piece 4a contact piece 4b contact piece 4c contact piece 4d Contact piece 4e Contact piece 5 Photosensitive drum 6 Drum 7 Flange 8 Flange 9 Brush 10 Mounting hole 11 Mounting hole 12 Notch groove 13 Claw piece 14 Bending line portion 15 Bending line portion 16 Abutting portion 16a Abutting portion 16b Abutting portion 16c contact part 16d contact part 16e contact part 17 rising part 17a rising part 17b rising part 17c rising part 17d rising part 17e rising part 18 bottom surface 19 narrow part 20 convex part 40 contact piece

Claims (6)

[Claims] 1. A hollow cylindrical drum having openings at both ends, a flange fitted in the opening, and a contact fixed to the flange and abutting against an inner surface of the drum when the flange is fitted. A ground plate structure in a photoconductor drum having a ground plate having a piece, wherein the ground plate is fixed to an end face of the flange on the fitting side, to the ground side,
At least the tip side of a fixing plate having a brush to be engaged, and a notch groove bent from the outer edge of the fixing plate and extending substantially along the axial direction of the drum and recessed on the fitting side of the flange. A flexible plate that is housed and a contact piece that is bent in a box shape at a substantially right angle from an extended end of the flexible plate, and the contact piece has a contact portion that contacts the inner surface of the drum. The ground plate of the photoconductor drum, which is formed of a claw piece surrounded by the bent line portion of the contact piece and each rising portion connecting the bent line portion and the end of the contact portion. Construction. 2. The contact portion of the contact piece has an arc shape, a polygon shape,
The ground plate structure for a photosensitive drum according to claim 1, wherein the ground plate structure is formed from a linear contour line. 3. The ground plate structure for a photosensitive drum according to claim 1, wherein an intersection angle β between the rising portion of the contact piece and the flexible plate on the surface of the contact piece is at least 90 ° or more. 4. A ground plate structure for a photosensitive drum according to claim 3, wherein at least a base end side of a rising portion having an intersection angle β exceeding 90 ° is in abutting engagement with a bottom surface of the cutout groove of the flange. . 5. The crossing angle α on the inner side between the flexible plate and the fixing plate is 90 ° or 90 ° or less.
Ground plate structure of the photoconductor drum. 6. The ground plate structure for a photosensitive drum according to claim 1, wherein a narrow portion is formed at a connecting portion between the flexible plate and / or the flexible plate and the fixing plate.