JP3455787B2 - Developing device - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention is plain paper for copiers BACKGROUND OF THE, printer, relates to a developing apparatus of an electrophotographic scheme such as a facsimile.

[0002]

2. Description of the Related Art Magnet rolls are used in electrophotographic developing devices such as copying machines and facsimiles.
The magnet roll has a function of picking up the developer from the developer box and delivering the developer to the photoconductor, and its specific mode is, as shown in FIGS. The developing cylinder r, which is formed by rotatably enclosing the sleeve s, is arranged so as to face the photosensitive drum D. The operation of delivering the developer by the magnet roll m is carried by each of a plurality of magnetic poles magnetized on the surface of the magnet roll, and the strength of the magnetic force of each magnetic pole and the magnetic pattern depend on the role of each magnetic pole. It is set.

As a conventional magnet roll m, as shown in FIG. 41 (a), a metal shaft b is inserted through the entire length of a cylindrical magnet body a obtained by extruding a resin magnet material (hereinafter referred to as shaft insertion magnet roll). Referred to as (), and (b) without using a metal shaft, the entire shaft including both end shafts c, c is integrally molded by injection molding using a resin magnet material (hereinafter, a metal shaftless solid magnet roll). It is known that the short-axis rods d and d are insert-molded at both ends of a solid cylindrical magnet body e (hereinafter referred to as rod-projecting solid magnet rolls), as shown in (c). ing.

[0004]

By the way, there are various problems in such a magnet roll. First, a shaft-insertion magnet roll having a metal shaft inserted over the entire length thereof requires an expensive metal shaft, and the fabrication thereof is performed by extruding the tubular magnet body a by extrusion molding or injection molding, and then making the hollow of the tubular magnet body a. Since it is necessary to insert the metal shaft b whose surface is coated with an adhesive, the manufacturing process is complicated and the productivity is low. Further, since the metal shaft is present at the center in the radial direction, the volume of the magnet is small and it is difficult to strengthen the surface magnetic force.

The metal shaftless solid magnet roll, which is made entirely of resin magnets including the shaft portion, is solid so that the magnet volume can be increased and a strong surface magnetic force can be realized. Since it does not have it, it has poor mechanical strength and may bend due to its own weight. Also,
There is a problem that the productivity is lower than that of the extrusion molding, because the molding can be performed only by the injection molding.

The rod-protruding solid magnet roll having the short-axis rod projecting at both ends is solid, so that the magnet volume can be increased, but the manufacturing process is more complicated than that of the shaft-inserting magnet roll. There is a problem that is not suitable for mass production. These three types of conventionally used magnet rolls have the above-mentioned problems, respectively. However, in addition to the above problems, these magnet rolls also have a problem regarding the positioning means when they are assembled in the developing device.

That is, the magnetic poles formed on the outer peripheral surface of the magnet roll each have a unique function regarding the transfer of the developer, and each magnetic pole is a developer box, a doctor blade,
It is necessary to arrange the magnet roll at a predetermined position and an angular relationship with respect to the photosensitive drum and the like. Therefore, positioning when the magnet roll is assembled to the developing device is extremely important. In the conventional magnet roll, positioning is performed by providing the D-cut portion g on the tip side of the shaft f as shown in FIGS. 42 and 43. However, when the shaft portion is a metal shaft, there is a problem that the processing cost increases. If the shaft portion is made of a resin magnet, there is a problem that the strength is insufficient.

[0008] The present invention has been made in view of such current situation, while maintaining high productivity and mechanical strength, also a magnet roll obtained also easily and strong surface magnetic force can make positioning, current By disclosing a structure suitable for being incorporated in an image device, it is intended to provide a developing device having a novel structure in which cost can be reduced while maintaining high productivity.

[0009]

DISCLOSURE OF THE INVENTION As a result of reexamination of the structure of the magnet roll in order to satisfy the above requirements regarding the magnet roll, the present inventor formed a magnet roll using a resin magnet material using a hard synthetic resin as a binder. In addition, by eliminating the shaft portion protruding from both ends of the magnet roll main body and forming the positioning means conventionally provided on the shaft portion directly on the surface of the magnet roll main body, the above-mentioned object can be achieved. Inspiring ideas
However, due to the structure of this magnet roll,
The assembling method is also different from the conventional magnet roll.
The present invention is a set suitable for the shaftless magnet roll.
Propose a new finding method and assemble in this way
The present invention provides a novel developing device.

That is, according to the present invention, magnetic powder is added to a hard synthetic resin.
A substantially cylindrical magnet body made of dispersed resin magnet material.
For the magnetless roll
The development sleeve is covered with a cylindrical sleeve that rotates freely.
The shaftless magnet is configured as a linder.
Fix both ends of the roll directly to the side wall of the developing device body.
The developing cylinder into the main body of the developing device.
A developing device including the shaftless magnet.
Grooves, holes or positioning means on the outer circumference of the end of the roll
Forms a notch surface, and is a member corresponding to the groove, hole or notch surface.
The joint part is formed on the inner surface and the upper part is open.
Inner surface shape that matches the curved shape of the outer surface of the magnet roll
-Shaped receiving member is integrally formed with the side wall of the developing device body
Or a separate structure to secure it to the side wall of the developing device body.
End of the magnet roll mounted on the receiving member
Touch the outer peripheral surface of the remaining part exposed from the receiving member on the outer periphery of the part.
A lid having a curved inner surface that matches the curved shape of the remaining outer peripheral surface
Cover the member and attach the end of the shaftless magnet roll.
A developing device configured by engaging and fixing is configured.

Here, the magnet roll is positioned
One or more grooves or one or more notches as a
Directly on the outer peripheral surface of the magnet body alone or in combination
At the same time, both ends of the magnet body are formed on the developing device.
Preferable as a direct attachment to the wall
Yes.

The groove or notch surface as the positioning means is made of a magnetic material.
It is also possible to provide the entire length of the stone in the longitudinal direction.
It may be provided on the outer circumference of one end or on the outer circumference of both ends in the hand direction.
Yes.

Further, a groove is formed over the entire length of the magnet body in the longitudinal direction.
Or, with a cutout surface, outside the one end of the magnet body in the longitudinal direction.
A groove or a groove different from the groove or the cutout surface is formed on the peripheral portion or both end outer peripheral portions.
A notch surface may be provided.

Further , a groove or notch surface as a positioning means
May be provided on the outer peripheral surface of the magnet body in the circumferential direction.
Yes, in this case the shape or size of each positioning means
Are preferably different.

Further , a groove or a cut as the positioning means is provided.
At least three cutouts in the circumferential direction on the outer circumferential surface of the magnet body
The above is provided and the distances between the respective positioning means are different.
Those formed are preferred.

In addition, the positioning means such as the groove and the notch surface are magnetized.
When installing over the entire length of the body, the magnet body of that part
There is concern about a decrease in magnetic force due to a decrease in product. Therefore position
The formation position of the means is a plurality of magnetic poles magnetized on the outer peripheral surface.
The magnetic pole formation position that requires magnetic force suppression.
And are preferred.

In the above-mentioned one, the positioning means is provided on the magnet body.
Although it was formed on the outer peripheral surface, the positioning means is a magnet
It may be provided on one or both end faces in the longitudinal direction of the body.
It

Further, on the outer peripheral surface or the longitudinal end surface of the magnet body,
In addition to providing positioning means , magnet roll
The length of the magnet to facilitate the assembly of the
Taper both ends in the hand direction outward to taper
Good.

As a supporting structure of a cylindrical sleeve rotatably mounted on a magnet roll, for example, the sleeve may be pierced through a hole formed in a side wall of the developing device main body and the sleeve may be directly supported by the side wall. Be considered. A sliding member may be interposed between the sleeve and the side wall hole portion, or may be directly supported without being interposed. Alternatively, a recess may be formed on the side wall of the developing device main body, and the recess may directly support the sleeve.

As the sliding member, for example, a rolling bearing, a sliding bearing, or the like can be adopted, and a coating layer of synthetic resin or metal having abrasion resistance may be provided and used as a substitute for the sliding member. As the plain bearing, a synthetic resin or a sintered metal in which a solid lubricant is dispersed or a liquid lubricant is impregnated can be used.

[0021]

The magnet roll used in the developing device of the present invention does not have a metal shaft, but since the resin magnet material uses a hard synthetic resin as a binder, it exhibits sufficient rigidity and bending due to its own weight occurs. There is nothing to do. Further, when a plurality of grooves, holes or cutout surfaces as the positioning means are provided on the outer peripheral surface of the magnet body in the circumferential direction and the shape or the size of each positioning means is different, pay attention to the shape and size of each positioning means. By paying, it is possible to more clearly recognize the assembling posture of the magnet roll, and it is possible to more reliably prevent the careless mistake of assembling the magnet roll in an incorrect posture. Also, when at least three or more grooves or notched surfaces of the same shape are provided on the outer peripheral surface of the magnet body in the circumferential direction and the distances between the respective positioning means are different, the assembling direction is not erroneous.

The developing device according to the present invention is a side wall of a main body device.
Place the end of the magnet roll on the receiving member fixed to
After that, cover the exposed end of the magnet roll with the lid member.
It has a support structure that covers and engages and fixes it.
The workability of assembling the Gunnet Roll to the main unit is significantly improved.
Will be improved.

The longitudinal ends of the field toward outward reduced in diameter in a tapered shape if the magnet body attached to the developing device body sidewall becomes easier.

[0024] Rotation of the outer circumference of the magnet roll in a non-contact state Sri chromatography blanking is in the state of being supported without intervention or is supported while interposing a sliding member on the side wall of the developing device main body, or the sliding member To do.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to illustrated embodiments. 1, 2, and 3 show the outline of the shaftless magnet roll of the present invention. The shaftless magnet roll M is a solid, substantially cylindrical magnet body 1 (hereinafter referred to as a magnet body 1) formed by extruding a resin magnet material in which magnetic powder is dispersed in a hard synthetic resin. A groove as a positioning means, a groove 2 having a U-shaped cross section in the illustrated example
a is formed over the entire length of the magnet body 1. Both ends of the shaftless magnet roll M are directly attached to the main body side member W such as a peripheral device or a developing container wall.

Since the U-shaped groove 2a is formed over the entire length of the magnet body 1, it can be formed at the same time as extrusion molding by providing a convex portion for groove formation on the molding die. This shaftless magnet roll is preferably extruded from the viewpoint of productivity, but it can also be formed by injection molding, and a groove is formed on the surface of a cylindrical magnet body formed by extrusion or injection molding by cutting or the like. You may form.

As the magnetic powder contained in the resin magnet material, barium ferrite, strontium ferrite, rare earth magnetic powder, or the like is used. Although a hard synthetic resin is used as the binder, the concept of this hard synthetic resin is to maintain sufficient rigidity even under the temperature inside the device in which the magnet roll is incorporated, and to bend the self-weight of the magnet roll of a size that poses a practical problem. It means a synthetic resin having a hardness that can prevent the above, and is intended for both thermoplastic resins and thermosetting resins. Specifically, it refers to one that can maintain sufficient rigidity even when exposed to a temperature environment of 60 ° C. for a long time. For example, a thermoplastic resin such as polyester, polyamide, or polyphenylene sulfide, or a thermosetting resin such as an epoxy resin is used. Can be adopted.

As shown in FIG. 2, such a shaftless magnet roll M is magnetized with the groove forming position as a mark, and a plurality of magnetic poles are formed on the surface. Since each magnetic pole has a predetermined arrangement relationship with the groove forming position, in the subsequent work, each shaft is attached to the developing device while paying attention to the groove arrangement position. It can be set so as to satisfy a predetermined relationship with the developer box, the doctor blade and the photosensitive drum.

In the above-mentioned embodiment, the shape of the groove provided on the outer peripheral surface of the substantially cylindrical magnet body 1 is U-shaped, but this shape may be another shape, for example, the V-shaped groove 2b ( (Fig. 4)
Alternatively, it may be an arcuate groove 2c (FIG. 5). Further, the positioning means may be something other than the groove, and for example, a flat notch surface 3 as shown in FIG. 6 can also be adopted.

These are cases where a single groove or cutout surface is provided. However, when the magnetized form of the magnetic poles formed on the outer peripheral surface is asymmetric in the radial cross section, such a single positioning means is used for the magnet roll. There is a possibility that the "direction" of will be wrong. What is shown in FIG. 7 is a case where a groove 2d having an asymmetric cross-sectional shape is formed in order to solve such a problem. Further, as a method for solving the above problem, as shown in FIG.
As shown in (b), a plurality of grooves having different shapes may be provided, or
It is also considered to use a groove and a notch surface together as shown in (c). Incidentally, the groove and the notch surface are provided not only over the entire length in the longitudinal direction of the magnet roll, but also, for example, at one end or both ends in the longitudinal direction, or further, the groove is provided over the entire length in the longitudinal direction and at one end or both ends in the longitudinal direction. Providing a notch surface is also considered. The main purpose of providing a plurality of positioning means in this manner is to prevent the "direction" of the magnet roll from being mistakenly incorporated.
Even if the magnetic poles formed on the outer peripheral surface are symmetrical and the "direction" at the time of assembly does not matter, it is possible to call more attention by providing multiple positioning means, so careless It can contribute to eliminating the mistake of installation.

The above-mentioned is a case where different kinds of positioning means are used together, but by forming a plurality of grooves of the same shape, it is possible to prevent a mistake in assembling. When forming a plurality of grooves of the same shape, it is necessary to consider the number of grooves and the distance between the grooves. That is, as shown in FIG. 9A, when two U-shaped grooves 2a having the same shape are provided, the "direction" of the magnet roll cannot be specified. Therefore, when a plurality of grooves having the same shape are used, it is necessary to set the number to three or more as shown in FIG. 9B and to make the distance between adjacent U-shaped grooves different.

As described above, the "direction" of the magnet roll can be specified by forming a plurality of grooves on the outer peripheral surface of the substantially columnar magnet body 1. However, all of these plurality of grooves are accurately formed at their forming positions. However, if only one groove is formed with high precision, the formation positions of the other grooves are not necessarily required to have high precision.

In the above description, the outer peripheral surface of the magnet body 1 is formed with grooves or notches over the entire length in the longitudinal direction. However, the grooves or notches as the positioning means are provided in a predetermined range at both ends of the magnet body 1. It may be provided only in. FIG. 10 shows this embodiment, (a) is a case where the U-shaped groove 2a ′ is provided at the end, and (b) is a case where a plurality of U-shaped grooves 2a ′, 2a ′ are provided at the end. . FIG. 11 shows a case where a notch surface is formed instead of the groove. In this embodiment, the notch surface 3a 'having the step 3b' is formed at one end, and the notch surface 3'having no step is provided at the other end so that the "direction" of the magnet roll can be easily identified. It is devised.

The positioning means has the most important function as a mark for determining the setting posture when the magnet roll is incorporated in the developing device. However, the positioning means uses the shape of the positioning means to make the shaft. It can also serve as a fixing means when the less magnet roll is directly attached to the peripheral device or the wall of the developing device. For example, as shown in FIG. 12A, a mounting hole 4 having a protrusion 5 corresponding to the groove of the magnet body 1 is formed at the inner edge of the main body member W of the developing device, and the magnet body 4 is attached to the mounting hole 4. Inlaying one end is considered. After the fitting, the U-shaped groove 2a of the magnet body 1 as shown in FIG.
And the projection 5 of the mounting hole 4 are engaged with each other to be in a fixed state, and positioning and fixing are performed at the same time. Needless to say, the combined use of the positioning means and the fixing means is also applicable to the case where the U-shaped groove 2a 'is provided only on the end portion of the magnet body 1 as shown in FIG.

In the above-mentioned embodiment, the groove is used as the positioning means to mount and fix the member on the main body side member of the developing device. However, as shown in FIG. 14, the cap-shaped connection having the projection 6 formed on the inner surface thereof is used. It is also possible to employ fixing to the peripheral device or the developing device wall via the member X.

When a groove or cutout surface is formed on the outer peripheral surface of the magnet body 1, the magnet volume at that portion decreases, and as a result, the surface magnetic force at that portion tends to decrease. Therefore, in consideration of this, it is preferable to set the forming positions of the groove and the notch surface as the positioning means so as to overlap with the forming positions of the magnetic poles for which it is necessary to suppress the surface magnetic force.
When the positioning means is provided only at both ends of the magnet body 1 in the longitudinal direction, only the surface magnetic force at both end portions of the magnet roll decreases, and the magnetic force in the usage area of the magnet roll does not decrease.

The formation position of the positioning means on the magnet body 1 may be formed on the end surface of the magnet body 1 as shown in FIGS. The positioning means may be formed on both end faces, but may be formed on only one end face. Various specific shapes of the positioning means formed on the end surface are considered, and for example, V
V-shaped groove 7a (FIG. 16), a pair of large and small cylindrical bottomed holes 7
b, 7b '(FIG. 17), an arcuate cross-section groove 7c (FIG. 18) having a recess at a position deviated to the one side from the middle, a keyhole-shaped bottomed hole 7d (FIG. 19), and a V-shaped groove 7a on one end surface. And a cylindrical bottomed hole 7b is provided on the other end surface (see FIG. 2).
0), a circular arc groove 7e having a wide cross section is provided on one end surface and an arc groove 7e 'having a narrow cross section is provided on the other end surface (FIG. 21), and a large diameter bottomed hole is provided at an eccentric position on the one end surface. It is possible to provide 7b 'and to provide a bottomed hole 7b having a small diameter on the other end surface (Fig. 22).

Further, as shown in FIGS. 23 and 24, a taper surface 8 having an outwardly reduced diameter is provided at the end of the magnet body 1 to facilitate the assembly of the magnet body 1 into the developing device. It is also preferable to

Although the above description relates to the shaftless magnet roll, a developing device in which the assembling mode of the shaftless magnet roll is devised will be described next. The developing device of the present invention is characterized in that the developing device is configured by directly fixing both ends of the shaftless magnet roll M to the side wall of the developing device main body. FIG. 25 shows an example of a method of supporting the shaftless magnet roll M. Although the sleeve is omitted in the illustrated example, a cylindrical sleeve is rotatably mounted on the shaftless magnet roll M by an appropriate method when used. In the illustrated embodiment, the side wall W1 is
This is a case where a through hole 10 having a projection 9 formed on the inner edge is opened, and the end of the magnet body 1 is fitted and supported in the through hole 10 as shown in FIG.

FIG. 26 shows a case where a bottomed recess 11 for receiving the end of the magnet body 1 is formed on the side wall W2, and the end of the magnet body 1 is fitted into the bottomed recess 11. In this case as well, the inner peripheral surface of the bottomed concave portion 11 is provided with the protrusion 12 corresponding to the groove on the outer peripheral surface of the magnet body 1.

FIG. 27 shows an accommodating space 14 in which an annular wall 13 is erected on the side wall W3 to receive the end of the magnet body 1.
And the projection 15 is erected at an eccentric position on the bottom surface of the accommodation space, and the end portion of the magnet body 1 having the bottomed hole 7b 'as a positioning means on the end surface is fitted into the accommodation space 14. This is the case. FIG. 28 shows a case in which the magnet roll M is supported only by fitting the protrusions 15 ′, 15 projectingly formed on the side wall W3 ′ into the bottomed holes 7b, 7b ′ formed on the end face of the magnet roll without providing the annular wall. Is. In the example shown in the drawing, the diameter of the bottomed holes 7b and 7b 'and the formation positions of the bottomed holes 7b and 7b' in the radial cross section of the magnet body are deviated to change the "direction" of the magnet roll at the time of mounting. We are trying to prevent mistakes.

FIG. 29 shows another method of incorporating the magnet roll M. According to this method, a half-cylindrical receiving member 22 having an engaging projection 21 corresponding to a U-shaped groove 2a formed on the outer periphery of the end portion of the magnet roll M and corresponding to a U-shaped groove 2a formed on the inner surface and having an upper opening. Is integrally formed from the side wall W3 "of the developing device main body, or is separately formed and fixed to the side wall W3" of the developing device main body, while at the outer periphery of the end of the magnet roll M placed on the receiving member 22. A semi-cylindrical cylindrical lid member 23 is covered on the remaining outer peripheral surface exposed from the receiving member to engage and fix the end portion of the magnet roll M.

Engaging projection 2 formed on the inner surface of the receiving member 22
1 may correspond to the groove shape formed on the magnet roll M side, and the shape is appropriately set corresponding to the groove shape. In addition, when the cutout surface 3'as shown in FIG. 11 is formed on the outer periphery of the end portion of the magnet roll M, as shown in FIG.
A receiving member 22a provided with an engaging portion 21a corresponding to the cutout surface 3'is used as shown in FIG.

Only the curved shape of the inner peripheral surface of the receiving member needs to match the curved shape of the outer peripheral surface of the magnet roll M, and the outer surface shape is not limited. Therefore, as shown in FIG. 32, the receiving member 22b and the lid member 23 having a square outer shape.
The use of b is also optional.

As a method of fixing the receiving member 22 and the lid member 23, various methods other than the method of adhesively fixing the joint end faces of both members are adopted. For example, as shown in FIG.
An engaging convex portion 24 having a bulged tip end is formed at a portion which becomes a joint portion of the receiving member 22c, and on the other hand, the engaging convex portion 24 can be passed over and engaged with the engaging convex portion 24 on the lid member 23c side. The elastic engaging piece 25 is provided and the lid member 23c is received by the receiving member 2
It is conceivable to elastically fit the 2c. When the end portion of the magnet roll M is placed on the receiving member fixed to the side wall of the main body apparatus as described above, and then the support structure is adopted in which the lid member is externally fitted to the exposed portion of the end portion of the magnet roll, The workability of assembling to the main unit is remarkably improved.

Although the above description has described only the method of supporting the shaftless magnet roll M, such a magnet roll functions as a developing cylinder when the sleeve is packaged. Although the method of supporting the sleeve is not described in each of the above-described embodiments, the supporting structure of the sleeve adapted to the structure of the shaftless magnet roll M of the present invention will be described here. FIG. 34
Is an example of the support structure of the sleeve. In this embodiment, the outer wall W4 is provided with a recess 16 for receiving the end of the magnet body 1.
And an inner wall W5 having a through hole 17 through which the sleeve S can be inserted, and the magnet body 1 is formed by the outer wall W4.
Directly supports the sleeve S by the inner wall W5.
Is rotatably supported. The edge of the through hole 17 is preferably surface-treated so that the sleeve S rotates smoothly. A metal plate can be used as the inner wall 17, but a resin plate can also be used. When a resin plate is used, it is easy to make the rim of the through hole 17 slippery, and it is possible to cut off electrical conduction with the sleeve S, so that the charged state of the sleeve surface can be maintained.
Reference numeral 18 in the drawing denotes a drive gear for transmitting the rotational force to the sleeve. As the sleeve S, a metal cylinder such as aluminum is generally used, but a synthetic resin cylinder or a paper cylinder can also be used. However, in this case, since it is not possible to apply a potential to the sleeve, it is necessary to devise a method of delivering the developer to the photosensitive drum.

A sliding member may be interposed between the inner wall W5 and the sleeve S for the purpose of improving sliding. As the sliding member, as shown in FIG.
Alternatively, the plain bearings 20 and 20 formed in a ring shape as shown in FIG. 36 can be used. As the plain bearings, those with both low friction coefficient and high wear resistance are adopted.For example, those in which solid lubricant is dispersed in synthetic resin or sintered metal or those in which liquid lubricant is impregnated are used. Can be used. Polyamide, polyimide, polyacetal, etc. can be adopted as the synthetic resin, and graphite, lead, graphite fluoride, molybdenum difluoride, etc. are effective as the solid lubricant, and are generally used as the liquid lubricant. Machine oil or grease can be used. Also, although not shown,
Instead of interposing a sliding member as a separate member between the inner wall W5 and the sleeve S, Teflon resin or the like may be applied to the inner edge of the through hole 17.

In FIGS. 34 to 36, the inner wall W5 for supporting the sleeve is provided separately from the outer wall W4. However, as shown in FIG. 37, the rolling bearing 19 is interposed between the outer wall W4 and the sleeve S. If the outer wall W4 supports the sleeve S, the inner wall can be omitted. Also in FIG.
As shown in, the rolling bearing 19 is provided between the magnet body 1 and the sleeve S.
Even when the sleeve S is supported with the interposition of, the inner wall can be omitted. In the embodiment shown in FIGS. 37 and 38, it is also possible to use a slide bearing instead of the rolling bearing 19.

Various means can be adopted as means for fixing the drive gear to the sleeve S, for example, FIG.
As shown in (a), a threaded hole 26 is provided at a predetermined position on one end of the sleeve in the longitudinal direction, while the threaded hole 2 is provided on the drive gear 18a.
7, the drive gear 18a is externally fitted to the end of the sleeve S, and the drive gear 18a is fixed to the sleeve S by using a screw 28. Alternatively, as shown in FIG. It is possible to adopt a method in which a cutout portion 29 is provided in the outer peripheral surface of the drive gear 18b, and the drive gear 18b having the fitting protrusion 30 formed on the inner peripheral surface thereof is externally fitted to the cutout portion 29. Although not shown, it is also considered that the sleeve and the drive gear are integrally formed by insert molding. In this case also, in order to prevent the drive gear from idling, a hole, groove, or notch is provided at the end of the sleeve. Is preferred.

[0050]

According to the developing device of the present invention,
Place the end of the magnet roll on the receiving member fixed to the side wall.
After placing, place the lid member on the exposed part of the end of the magnet roll.
Has a support structure that covers and engages and fixes the
The workability of assembling the magnet roll into the main unit is remarkably high.
Will be improved. The shaftless magnet roll can be set in the developing device by using the positioning means directly formed on the outer peripheral surface of the magnet body as a mark. Since this shaftless magnet roll does not require an expensive metal shaft, the cost of parts for the metal shaft can be reduced, and since the shaft itself is eliminated, the step of inserting the metal shaft is not required, and high productivity can be realized. Although this magnet roll does not have a metal shaft, its resin magnet material uses hard synthetic resin as a binder, so it exhibits sufficient rigidity, and due to its own weight even when exposed to the temperature in the operating environment for a long time. It does not bend. Furthermore, since the magnet is solid and has a large volume, it is easy to increase the surface magnetic force. Further, the positioning at the time of incorporation into the developing device is easy, and since both ends of the magnet body are directly attached to the developing device wall, the number of parts can be reduced. In this way, the shaftless magnet roll can reduce the number of parts and simplify the assembly process while maintaining high productivity.

When the groove or the notch surface as the positioning means is provided over the entire length in the longitudinal direction of the magnet body, since the magnet roll has a uniform cross-sectional shape over the entire length, the one manufactured by extrusion molding is end-processed. It can be used as it is without post-processing such as, and productivity can be dramatically improved.

Further , a groove, a hole or a notch as a positioning means
The surface of the outer peripheral surface at one end or both ends in the longitudinal direction of the magnet body.
Only one side or both ends of the magnet body in the longitudinal direction
When a groove or hole is provided on the surface as positioning means,
It does not reduce the surface magnetic force in the usage area.
Yes.

As positioning means, a plurality of grooves or cutout surfaces having different shapes or different sizes are provided in the outer circumferential surface of the magnet body in the circumferential direction, or at least three grooves or cutout surfaces having the same shape are provided in the outer circumferential surface of the magnet body in the circumferential direction. When the distances between the respective positioning means are different from each other, the "direction" of the magnet roll can be accurately grasped, and inadvertent assembling errors can be prevented as much as possible.

Further, grooves, holes provided on the surface of the magnet body,
Among the positioning means of the cut surface or the like, parts component located longitudinal end of the magnet body can be utilized as a mounting fixing means to the developing device wall.

The developing device of the present invention can reduce the number of parts and simplify the assembling process, and can provide a highly accurate developing device at low cost.

[Brief description of drawings]

A front view showing an outline of shaftless magnet roll according to the invention, FIG

FIG. 2 is a radial cross-sectional view of one embodiment of the shaftless magnet roll.

FIG. 3 is a perspective view of a main part of a magnet body when a groove having a U-shaped cross section is adopted as a positioning means.

FIG. 4 is a perspective view of a main part of a magnet body when a groove having a V-shaped cross section is adopted as a positioning means.

FIG. 5 is a perspective view of an essential part of a magnet body when a groove having an arcuate cross section is adopted as a positioning means.

FIG. 6 is a perspective view of a main part of a magnet body when a notch surface is used as a positioning means.

FIG. 7 is a perspective view of a main part of a magnet body when a groove having an asymmetric cross-sectional shape is used as a positioning unit.

[Fig. 8] (a), (b), (c) are cross-sectional views of the magnet body when different types of positioning means are combined.

9 (a) and 9 (b) are sectional views of a magnet body when a plurality of positioning means of the same shape are used.

10 (a) and 10 (b) are perspective views of a main part of the magnet body when the positioning means is provided only on the end portion of the magnet body.

FIG. 11 is a perspective view of a main part of the magnet body in which a notch surface as a positioning means is provided only on both ends of the magnet body and a step is provided on the notch surface on one end side.

FIG. 12 shows an embodiment in which the groove of the shaftless magnet roll also has a function as a fixing means,
(A) is an explanatory perspective view showing a state before fitting, and (B) is a sectional view showing a state after fitting.

FIG. 13 is an explanatory perspective view showing another embodiment in which the groove of the shaftless magnet roll also has a function as a fixing means.

FIG. 14 is an explanatory perspective view showing an embodiment in which a groove of the shaftless magnet roll also has a function as a fixing means and a cap-shaped fixture is attached.

FIG. 15 is a cross-sectional explanatory view showing an example of a magnetic pattern of a magnet body.

FIG. 16 is a perspective view of an essential part of the magnet body when a groove having a V-shaped cross section is adopted as the positioning means when the positioning means is provided on the end surface of the magnet body.

FIG. 17 is a perspective view of a main part of a magnet body in the case where a positioning means is provided on an end surface of the magnet body and a pair of large and small bottomed holes is adopted as the positioning means.

FIG. 18 is a perspective view of a main part of a magnet body in the case where a positioning means is provided on an end surface of the magnet body and a groove having an arcuate cross section in which a recess is formed at an eccentric position is used as the positioning means.

FIG. 19 is a perspective view of a main part of a magnet body when a positioning means is provided on an end surface of the magnet body and a keyhole-shaped bottomed hole is used as the positioning means.

FIG. 20 shows a groove having a V-shaped cross section on one end surface as positioning means when the positioning means is provided on the end surface of the magnet body.
Perspective view of essential parts of magnet body when bottomed hole is adopted on the other end surface

FIG. 21 shows a magnet body in the case where a positioning means is provided on the end surface of the magnet body and a groove having a wide cross-sectional arc shape is used at one end surface and a narrow width arc-shaped groove at the other end surface as the positioning means. Perspective view of main parts

FIG. 22 is a perspective view of a main part of a magnet body in the case where a positioning means is provided on the end surface of the magnet body and a bottomed hole is formed at the eccentric position of one end surface and the center position of the other end surface as the positioning means.

FIG. 23 is a front view when a groove is provided on the outer peripheral surface of the magnet body and a tapered surface is provided at an end portion of the magnet body.

FIG. 24 is a front view when a V groove is provided on the end surface of the magnet body and a taper surface is provided on the end portion of the magnet body.

FIG. 25 shows an example of a method for supporting a shaftless magnet roll, (a) is a front explanatory view, and (b) is a radial cross-sectional explanatory view.

FIG. 26 shows an example of a method of supporting a shaftless magnet roll, (a) is a front explanatory view, and (b) is a radial cross-sectional explanatory view.

FIG. 27 shows an example of a method for supporting a shaftless magnet roll, (a) is a front explanatory view, and (b) is a radial cross-sectional explanatory view.

FIG. 28 shows an example of a method for supporting a shaftless magnet roll, (a) is a front explanatory view, (b) and (c) are radial direction sectional explanatory views.

FIG. 29 is an exploded perspective view showing an example of a method of supporting a shaftless magnet roll.

FIG. 30 is a radial cross-sectional view showing a state where a magnet roll is supported by the same supporting method.

FIG. 31 is an exploded perspective view showing another example of the receiving member and the lid member.

FIG. 32 is an exploded perspective view showing another example of the receiving member and the lid member.

FIG. 33 is a radial cross-sectional view showing a state in which the lid member is elastically fitted to the receiving member.

FIG. 34 is a partial cross-sectional explanatory view showing an example of a method of supporting the sleeve, in the case where the sleeve is directly supported by a through hole formed in the inner wall.

FIG. 35 is a partial cross-sectional explanatory view showing an example of a sleeve supporting method, in which a rolling bearing is supported between the sleeve and the inner wall;

FIG. 36 (a) is a partial cross-sectional explanatory view showing an example of a method of supporting the sleeve, and when the sliding bearing is supported between the sleeve and the inner wall, (b) is a perspective view showing the appearance of the sliding bearing. Figure

FIG. 37 is a partial cross-sectional explanatory view showing an example of a sleeve supporting method, in which a rolling bearing is supported between the sleeve and the outer wall;

FIG. 38 is a partial cross-sectional explanatory view showing an example of a method of supporting the sleeve, in the case where the rolling bearing is interposed between the sleeve and the magnet body.

39 (a) and 39 (b) are explanatory views showing a method of fixing the drive gear to the sleeve end portion.

FIG. 40A is an explanatory view showing a general structure of a conventional developing device, and FIG. 40B is a sectional explanatory view of a conventional developing cylinder.

FIG. 41 shows an aspect of a conventional magnet roll,
(A) is a shaft-insertion magnet roll, (B) is a metal shaftless solid magnet roll, and (C) is a rod protruding solid magnet roll.

FIG. 42 is a perspective view of an essential part showing an example of a conventional magnet roll positioning means.

FIG. 43 is a perspective view of an essential part showing an example of a conventional magnet roll positioning means.

[Explanation of symbols]

M shaftless magnet roll S Sleeve W Body side member W1 side wall W2 side wall W3 side wall W3 'side wall W3 "side wall W4 outer wall W5 inner wall X Cap-shaped connecting member 1 Almost cylindrical magnet body 2a U-shaped groove 2b V-shaped groove 2c Arc-shaped groove 2a 'U-shaped groove 2b' U-shaped groove 2b V-shaped groove 2c Arc-shaped groove 3 notch surface 3'notch surface 3a 'notch surface 3b' step 4 Mounting hole 5 Projection 6 Projection 7a V-shaped groove 7b bottomed hole 7b 'bottomed hole 7c Arc-shaped groove 7d Keyhole-shaped bottomed hole 7e Arc-shaped groove 8 Tapered surface 9 Projection 10 Through hole 11 Bottomed recess 12 Projection 13 annular wall 14 accommodation space 15 protrusion 15 'protrusion 16 recess 17 through hole 18 Drive gear 19 Rolling bearing 20 Sliding bearing 21 Engaging protrusion 22 Receiving member 23 Lid member 24 Engagement convex portion 25 Elastic engagement piece 27 screws 28 screws 29 Notch 30 Fitting protrusion

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-81009 (JP, A) JP 61-206204 (JP, A) JP 62-135861 (JP, A) JP 54- 59943 (JP, A) JP 63-7604 (JP, A) JP 63-289908 (JP, A) JP 62-79482 (JP, A) Actual Kaihei 1-135453 (JP, U) Actually open 63-82263 (JP, U) Actually open 63-2958 (JP, U) Actually open 60-36659 (JP, U) Actually open 61-164005 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/08-15/095

Claims (15)

(57) [Claims] 1. A shaftless magnet of a substantially cylindrical magnet body made of a resin magnet material in which magnetic powder is dispersed in a hard synthetic resin.
The magnet roll to the magnet roll.
A developing cylinder is constructed by coating the rotating cylindrical sleeve.
Both of the shaftless magnet rolls
By fixing the end part directly to the side wall of the developing device main body,
The developing cylinder is installed in the main body of the developing device.
An image device, which is positioned on the outer periphery of the end of the shaftless magnet roll.
A groove, a hole or a notch surface as a locking means, and an engaging portion corresponding to the groove, hole or the notch surface is formed on the inner surface.
And the upper part is open and the magnet roll
A receiving member having an inner surface shape that matches the curved shape of the outer peripheral surface.
Is integrally formed with the side wall of the developing device main body, or is
The outer circumference of the end of the magnet roll, which is structured as a body and fixed to the side wall of the developing device main body, is placed on the receiving member.
On the outer peripheral surface exposed from the receiving member in
A lid member having a curved inner surface that matches the curved shape of the outer peripheral surface
Cover and engage the end of the shaftless magnet roll.
A fixed developing device. 2. The magnet roll is a positioning means.
One or more grooves or one or more notches as
Directly formed on the outer peripheral surface of the magnet body in the state of combining
And the both ends of the magnet body to the developing device wall body.
The developing device according to claim 1, wherein the developing device is a direct attachment part of
Place 3. The groove or notch surface as the positioning means is provided over the entire length in the longitudinal direction of the magnet body.
2. The developing device according to 2. 4. A groove or notch surface as the positioning means is provided only on the outer peripheral portion at one end or both outer peripheral portions in the longitudinal direction of the magnet body.
The developing device according to claim 3, wherein the developing device is provided. 5. A longitudinal direction of a magnet body as the positioning means.
A groove or notch surface is provided along the entire length in the
Longitudinally one end outer peripheral portion or both end outer peripheral portions of the stone body before Kimizo or
The groove or notch surface different from the notch surface is provided.
Developing device. 6. A groove or notch surface as the positioning means.
Are provided on the outer peripheral surface of the magnet body in the circumferential direction, and
3. The positioning means are different in shape or size.
4. The developing device according to any one of 4 to 4. 7. A groove or notch surface as the positioning means
At least three or more in the circumferential direction on the outer peripheral surface of the magnet body.
And the distance between each positioning means is different.
The developing device according to any one of claims 2 to 4. 8. A magnetic pole among a plurality of magnetic poles magnetized on the outer peripheral surface.
The magnetic pole formation position that requires force suppression is
Set at a position where a groove or notch surface is provided.
The developing device according to any one of 2 to 7. 9. The magnet roll is the longitudinal direction of a magnet body.
Groove on one or both end faces in the direction
2. One or both of the holes are directly formed.
Developing device. 10. The magnet roll is the length of a magnet body.
Taper both ends in the hand direction outward to taper
The developing device according to any one of claims 1 to 9. 11. The shaftless magnet roll
The developing device is a sleeve that is rotatably mounted on the sleeve.
The hole is formed in the side wall of the main body, and
2. The developing device according to claim 1, wherein the sleeve is directly supported.
Place 12. A contract in which a sleeve which is rotatably mounted on the shaftless magnet roll is directly supported by a recess formed in a side wall of a developing device main body.
The developing device according to claim 1. 13. A sliding member between the sleeve and the side wall hole portion.
13. The developing device according to claim 11, wherein the developing device is interposed. 14. A rolling bearing or a sliding member is used as the sliding member.
Rolled bearing or wear resistant synthetic resin or metal coating layer
14. The developing device according to claim 13, wherein the developing device is adopted. 15. A synthetic resin or a baked material for the sliding bearing.
Contains solid lubricant dispersed in binder metal or liquid lubricant.
15. The developing device according to claim 14, which is soaked.
Place