JPH09306726A - Magnet roll shaft body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable inexpensive manufacturing, and sufficiently exhibit performance of a magnet roll. SOLUTION: A shaft body 1A of a magnet roll is constituted of a shaft member and shafts 11, 12 connected to both ends of the shaft member. The shaft member is constituted of the main frame member 41 and a cover member 42 covering an opening portion 29 of the main frame member 41, and the main frame member 41 and the cover member 42 are formed by pressing. Thus, the initial cost is reduced. In addition, by causing the shaft member to have a closed polygonal cross section, a permanent magnet fixed on the shaft member is uniformly arranged in a circumferential direction, thus reducing unevenness in the magnetic field as much as possible and realizing stabilization of performance of the magnet roll.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet roll shaft used in, for example, a magnet roll for electrostatic development of an electrostatic copying machine to which a photoelectric effect and an electrostatic phenomenon are applied.

[0002]

2. Description of the Related Art Conventionally, magnet rolls for electrostatic development are
A plurality of rod-shaped permanent magnets are fixed to a resin-made support body arranged at a predetermined interval on a non-magnetic shaft. However, since the cost of the non-magnetic shaft is high, in order to reduce the cost, only the both ends are composed of the non-magnetic shaft and the permanent magnet is supported in order to reduce the cost. A magnet roll has been proposed in which the body portion to be formed is formed by pressing.

In the above-mentioned conventional example, by fixing the permanent magnet on a plane formed by press working,
A magnet roll is configured, and the body part can be manufactured at low cost by press working, and the expensive shaft part is reduced, so that it can be manufactured at low cost as a whole.

[0004]

However, in the above-mentioned conventional structure, the number of surfaces for fixing the magnets is small, and the number of magnets that can be held is limited. Also, since the position close to the shaft is the fixed surface of the magnet, in order to bring the working surface of the magnet close to the inner peripheral surface of the sleeve, the shape of the magnet itself must be large, and the size of the magnet must be large. However, there is a drawback that the area of the working surface of the magnet facing the sleeve is reduced.

On the other hand, in recent years, the performance of electrostatic copying machines has been improved day by day, and higher performance printing performance has been demanded, so that the magnetic poles of the magnet roll are set to have less unevenness in the circumferential and axial directions. Has been requested. In order to meet such a request, it is necessary to arrange a large number of magnets at equal intervals in the circumferential direction, and it is preferable to widen the working surface of the magnet. Further, if the fixed surface for fixing the magnet is distorted, a problem such as a gap being formed between the magnet and the fixed surface occurs, and unevenness occurs in the magnetic field emitted from the magnet. Further, if the number of fixed surfaces is increased to increase the number of magnets, it becomes difficult to improve the flatness of each fixed surface.

When the flatness of the fixed surface is impaired and the magnetic field generated by the magnet is uneven, the performance of the magnet roll is deteriorated and the quality of printing is deteriorated. Further, in order to reduce the weight of the entire printing apparatus, it is desirable to use a small and strong magnet, but it is difficult to reduce the size of the magnet with the above-described conventional configuration.

An object of the present invention is to provide a shaft body for a magnet roll which can be manufactured at low cost and can sufficiently bring out the performance of the magnet roll.

[0008]

The above objects are achieved by the present invention as described below.

(1) A shaft body for a magnet roll, which has a shaft member having a plurality of flat surfaces, to which permanent magnets are fixed, and a shaft fixed to an end of the shaft member. The shaft member includes a main body member in which three or more flat surfaces are formed by press molding, and a lid that covers an opening formed as a result of press molding of the main body member, and has a cross-sectional shape of the shaft member. A shaft body for a magnet roll, which has a closed polygonal shape.

(2) The lid body has any one of a contact surface contacting an inner side surface adjacent to the opening of the body member, an inner side surface contacting the contact surface of the body member, and the contact surface. One of the convex portions is provided, and the other has a space that accommodates the convex portion and restricts the movement of the accommodated convex portion, and the convex portion and the space are provided at predetermined intervals. A plurality of shaft bodies for a magnet roll according to (1) above, which are provided in a plurality of directions.

(3) The magnet roll shaft body according to the above (2), wherein the lid body has a leg portion whose tip is in contact with the inner surface of the main body member.

(4) Further, the magnet according to (3), wherein the lid has an abutting portion which is formed on an end side of the convex portion formed at the most end and which abuts on the shaft. Shaft for rolls.

(5) The magnet roll shaft body according to (2), wherein the surface of the lid body facing the main body member is in contact with the end of the open portion of the main body member.

(6) The body member and the lid are
The magnet roll shaft body according to any one of (1) to (5) above, wherein a positioning protrusion for positioning the magnet is formed integrally with the main body member and the lid body.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is an exploded perspective view showing a first embodiment of the present invention, FIG. 2 is an assembled view of the same, and FIG. 3 is a transverse sectional view of the same in an assembled state. The magnet roll shaft 1A of the first embodiment is
It has five outer surfaces 21, 22, 23, 24, 25, and each outer surface 21-25 has a permanent magnet 31, 32, 33, 34 ,.
A shaft member 2 to which 35 is fixed, and shafts 11 and 12 fixed to both ends of the shaft member 2 are provided.

The shaft member 2 comprises a main body member 41 and a lid 42. The main body member 41 and the lid 42 are made of a magnetic material such as steel. Body member 41
Is formed by press molding to have a U-shaped cross-sectional shape whose opening side is widened, and has three outer surfaces 21, 22, 23.
And is formed into a rod-shaped body having three inner side surfaces 26, 27, 28 and an opening portion 29. Positioning projections 411 and 411 for positioning the shafts 11 and 12 are provided at both ends of the main body member 41, and end members 412 and 412 are provided at both ends. Protrusion 4
11, 411 and the end members 412, 412 are the main body member 4
It is formed integrally with 1 and is bent at the time of press working.

The positioning protrusions 411 and 411 are formed with semicircular locking holes to which the base ends of the shafts 11 and 12 are connected (see FIG. 7), and are formed in the same sectional shape as these holes. The base ends of the shafts 11 and 12 are connected to the holes to ensure the integral rotation of the shaft member 2 and the shafts 11 and 12. Further, the shafts 11 and 12 are fixed to the inner surface 27 of the main body member 41 by welding. By fixing the shafts 11 and 12 by welding, the mounting positions of the shafts 11 and 12 with respect to the shaft member 2 can be made more accurate. Particularly, in the case of spot welding, the shafts 11 and 12 can be mounted with higher accuracy. It becomes possible to fix it.

Although not shown, the shafts 11 and 12
And the shaft 1 for adjusting the positional relationship of the shaft member 2.
A spacer may be inserted between the inner surface 27 and the inner surface 27. When inserting such a spacer, holes are formed at both ends of the outer surface 22 of the main body member 41, the spacer and the main body member 41 are spot-welded on both sides of the hole, and then the spacer and the shaft are inserted. Spot welding 11 and 12. In this case, the electrode for welding is pressed directly against the spacer through the hole. Locking parts 412, 4
12 has a hole 41 for inserting the shafts 11 and 12.
3 are provided.

A pair of claws 414, 415, which are projections for positioning the permanent magnets 31, 32, 33, are provided at two or three locations on each of the outer side surfaces 21, 22, 23, respectively. The claws 414 and 415 are respectively provided on the opposite side surfaces of the outer side surfaces 21, 22, and 23 so as to be positioned by sandwiching the permanent magnets 31, 32, and 33 from both sides.

Also, the inner surface 26 adjacent to the opening 29,
Three elongated holes 416 are formed at a position close to the side edge of the open portion 29 side on the 28, and a space for accommodating a convex portion described later is formed in the elongated hole 416. There is.

On the other hand, the lid body 42 is formed by press molding so that the cross-sectional shape thereof is a dogleg shape.
25 is formed into a rod-shaped body. On both sides of the lid 42, a pair of legs 421 bent downward in the drawing are formed.
(One leg is hidden behind the lid 42 and is not shown in FIG. 1.) A plurality (three pairs in the case of the present embodiment) are provided at equal intervals. In addition, the long hole 416
421 arranged at a position corresponding to the formation position of the
The outer surfaces of a and 421b are contact surfaces 422 that come into contact with the inner side surfaces 26 and 28 of the main body member 41 when the lid 42 is fitted to the main body member 41, and are located at the positions where the long holes 416 are formed. The contact surface 422 of the leg portion 421a provided at the corresponding position is provided with a convex portion 423 that bulges outward.

As a result of forming the cross-section into a dogleg shape by press molding, the lid 42 has two outer surfaces 24 and 25, as shown in FIG. A pair of claws 424 and 425, which are projections for positioning the permanent magnets 34 and 35 as shown in FIG. 3, are provided on each of the outer surfaces 24 and 25 at two to three locations, respectively. ing. The claws 424 and 425 are formed on the outer side surfaces 24,
The permanent magnets 3 are provided on both opposite sides of 25, respectively.
Positioning is performed by sandwiching 4, 35 from both sides.

Further, at both ends of the lid 42, projections are formed on the back side surfaces of the outer side surfaces 24 and 25, and contact portions 426 are provided. The contact portion 426 is provided on the shaft 1 when the lid 42 is fitted to the body member 41.
It abuts on the side surfaces of 1 and 12.

When assembling the main body member 41 and the lid 42 configured as described above, as shown in FIG. 1, the leg portion 421 is attached to the open portion 29 of the main body member 41. The lid 42 is press-fitted by being pushed into the inside 41. At this time, the protrusion 423 provided on the leg 421a
Enters the main body member 41 while pushing open the open portion 29 of the main body member 41, and as shown in FIG.
When the position 16 is reached, the body member 41 is housed in the space inside the elongated hole 416, and the main body member 41 returns to the original undistorted state. At this time, the tips 42 of the legs 421a and 421b are simultaneously formed.
0 abuts on the inner side surface 27 of the body member 41.
In the case of this embodiment, as shown in FIG. 3, the shaft member 2 has a pentagonal cross-sectional shape.

The lid 42 and the main body member 41 can be combined by welding or press fitting, but when these methods are used, the lid 42 and the main body member 41 are distorted, and the required accuracy is sufficiently high. Can't get to. For example, each outer surface 21, 22, 23, 24, 25 is curved to allow the permanent magnet 3
There arises a problem that 1, 32, 33, 34, 35 cannot be fixed with a designed desired accuracy. However, according to the configuration of the present invention, since the convex portion 423 is housed in the space of the long hole 416, once the lid body is fitted into the body member 41, the lid body 42 and the body member 41 are provided. The lid 42 can be fixed to the main body member 41 without causing distortion. Further, even if a force for further pushing the lid 42 into the main body member 41 is applied, the distal ends 420 of the leg portions 421a and 421b are in contact with the inner side surface 27 of the main body member 41, so that the lid 42 is distorted or damaged. The deformation of the main body member 41 due to the lid body 42 being further pushed into the main body member 41 is also suppressed. Further, since the hole is long in the axial direction, a processing error can be absorbed and the lid 42 can be easily attached. Further, regarding the end portion of the lid body 42, the shafts 11 and 12 contact the contact portion 426 to suppress the deformation of the end portion. The positioning of the lid 42 in the axial direction is performed by contacting both ends of the lid 42 with the inner side surfaces of the locking portions 412, 412.

The outer side surfaces 21, 22, 23, 24, 25 of the magnet roll shaft 1A constructed as described above.
The permanent magnets 31, 32, 33, 34, 35 are attached to the respective magnets, and the shafts 11, 12 are concentrically provided in the non-magnetic sleeve 5, as shown in FIG.

Next, the configuration of the second embodiment will be described in detail. FIG. 4 is an exploded perspective view showing a second embodiment of the present invention,
5 is an assembly drawing of the same, and FIG. 6 is a transverse sectional view of the same in an assembled state. In the magnet roll shaft body 1B of the second embodiment, the shaft member 6 has a quadrangular cross-sectional shape.

Shaft 1 for magnet roll of the second embodiment
B has four outer side surfaces 61, 62, 63 and 64, and the shaft member 6 to which the permanent magnets 36, 37, 38 and 39 are fixed to the respective outer side surfaces 61 to 64, and both end portions of the shaft member 6. Shafts 13 and 14 fixed to.

The shaft member 6 has a main body member 71 and a lid 72. The main body member 71 and the lid 72 are made of a magnetic material such as steel. The main body member 71 is formed by press molding to have a U-shaped cross-sectional shape in which the opening side is widened, and the three outer side surfaces 61, 62,
63, three inner surfaces 65, 66, 67 and the opening 6
8 is formed into a rod-shaped body.

The shaft 1 is provided at both ends of the main body member 71.
Positioning projections 711 for positioning 3, 4;
711 is projectingly provided, and the end members 71 are provided at both ends.
2, 712 are provided. The protrusions 711, 711 and the end members 712, 712 are formed integrally with the main body member 71, and are formed by being bent during press working. The relationship between the positioning protrusions 711 and 711, the end members 712 and 712, and the shafts 13 and 14 is the same as that of the configuration of the first embodiment, and thus the description thereof is omitted. The locking portions 712, 712 are provided with holes 413 for inserting the shafts 13, 14.

A pair of claws 714 and 715, which are projections for positioning the permanent magnets 31, 32 and 33, are provided at two or three places on each of the outer side surfaces 61, 62 and 63, respectively. The claws 714, 715 are respectively provided on opposite sides of the outer side surfaces 61, 62, 63 so as to sandwich the permanent magnets 31, 32, 33 from both sides for positioning. Furthermore, each outer surface 6
Claws 718 similar to the above-mentioned claws 714 and 715 are provided at both ends of 1, 62 and 63, respectively, and the permanent magnets 31, 32 and 33 to be fixed are axially positioned by these claws 718.

Further, the inner side surface 65 adjacent to the opening 68,
Three elongated holes 716 are formed in the 67 at positions close to the side end portions 717, 717 on the open portion 68 side at equal intervals, and a space for accommodating a convex portion described later is formed in the elongated hole 716. Has been formed. Further, at the side end 717 of the outer side surface 61, an engaging portion 719 is formed at a position corresponding to the elongated hole 716 close to the shaft 13 so as to project upward from the side end 717. The engaging portion 719 engages with an engaging concave portion 728 formed in the lid 72 described later.

On the other hand, the lid 72 is formed in a plate shape and constitutes one outer surface 64 of the shaft member 6. A pair of legs 721 bent downward in the drawing (one leg is behind the lid 72 and is not shown in FIG. 4) are formed on both sides of the lid 72. A plurality (three pairs in the case of the present embodiment) are provided at substantially equal intervals. Also, the legs 721, 7
The outer surface of 21 is a contact surface 722 that comes into contact with the inner surfaces 65 and 67 of the main body member 71 when the lid body 72 is fitted to the main body member 71, and the elongated hole 716 in the contact surface 722. The protrusions 723 protruding outward are provided at the positions corresponding to the formation positions of.

Since each leg portion 721 is formed by bending, the base end portion of each leg portion 721 is a concave portion that is recessed inward from the side of the lid body 72. Among the concave portions formed at the base ends of the leg portions 721, the engaging portion 719 is provided.
The concave portion at the position corresponding to the above
9 is an engaging recess 728 with which 9 is engaged. A pair of claws 724 and 72, which are projections for positioning the permanent magnet 39 as shown in FIG. 6, are provided on both sides of the lid body 72.
5 are provided at each of four locations.

When assembling the main body member 71 and the lid 72 configured as described above, as shown in FIG. 4, the leg portion 721 is attached to the open portion 68 of the main body member 71. The lid 72 is press-fitted by being pushed into the inside 71. At this time, the convex portion 723 provided on the leg portion 721 is
The body member 7 is pushed while the opening 68 of the body member 71 is widened.
1 into the slot 716, as shown in FIG.
When the position is reached, the body member 71 housed in the space in the slot 716 and expanded is restored to its original shape without distortion. In the case of this embodiment, as shown in FIG. 6, the cross-sectional shape of the shaft member 6 is a quadrangle.

Also in the case of this embodiment, the same effects as those of the first embodiment are obtained, and according to the structure of this embodiment, the convex portion 7 is formed.
Since 23 is accommodated in the space of the elongated hole 716, once the lid is fitted into the main body member 71, the lid 72
Alternatively, the lid body 7 can be formed without causing distortion in the main body member 71.
2 can be fixed to the main body member 71.

Further, in the case of this embodiment, the lid 72
Since the side end portion 726 of each of them contacts the both end portions 717 and 717 of the opening portion 68 of the main body member 71, even if a force for further pushing the lid body 72 into the main body member 71 is applied, the lid body 72 is not distorted. Deformation of the main body member 71 due to occurrence of the lid body 72 or further pushing of the lid body 72 into the main body member 71 is also suppressed. The lid 72 is axially positioned by the engagement between the engaging portion 719 and the engaging recess 728. The engaging recess 728 is a recess formed when the leg 721 is formed. Therefore, there is an advantage that it is not necessary to make a special positioning structure. Further, since the engaging portion 719 is also provided on the side end portion 717 and can be formed integrally with the main body member 71 at the time of punching, there is an advantage that no special processing is required.

The outer surfaces 61, 62, 63, 64 of the magnet roll shaft 1B constructed as described above are
Permanent magnets 36, 37, 38, 39 are attached respectively, and shafts 13, 14 are concentrically provided in a non-magnetic sleeve (not shown) as in the first embodiment.

The method of manufacturing the main body member described above will be described by taking the main body member 71 of the second embodiment as an example. As shown in FIG. 7, a plate member having a positioning protrusion 711, a locking portion 712, a hole 713, and claws 714 and 715 is formed by punching. Next, as shown in FIG. 8, the claws 714, 715 are bent and raised, and then pressed to form a body having a U-shaped cross section as shown in FIGS. 4 and 6. Member 71
Is formed. Further, the open portion 68 is formed by pulling out the press die. This method is similarly performed for the main body member 41 and the lid 42 of the first embodiment. In this way, the positioning projections, the locking portions, the claws, and the like can be integrally formed from a single plate material, so that they can be manufactured inexpensively and quickly.

In the embodiment of the present invention described above, the case where the shaft member has a quadrangular or pentagonal sectional shape has been described, but other polygonal shapes may be used. The space may be formed not only by the long holes 416 and 716 but also by a recess. Further, it is not limited to the long hole, but may be a circular hole. Further, the convex portion may be formed on the inner side surface of the main body member, and the elongated hole may be formed on the leg portion of the lid.

[0041]

According to the shaft body for a magnet roll of the present invention as described above, the flatness of the side surface to which the magnet is fixed is secured, so that the performance of the magnet can be sufficiently exhibited and the magnet can be made uniform. A magnetic field can be emitted. Also, by increasing the diameter of the shaft member, the side surface to which the magnet is fixed can be brought closer to the inner peripheral surface of the sleeve, so a thinner magnet can be used than before, and the inner peripheral surface can be opposed. Since the area of the working surface of the magnet can be widened, a lightweight and high-performance magnet roll can be obtained.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a first embodiment of the present invention.

FIG. 2 is an overall perspective view of the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of the first embodiment of the present invention.

FIG. 4 is an exploded perspective view of a second embodiment of the present invention.

FIG. 5 is an overall perspective view of a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of the second embodiment of the present invention.

FIG. 7 is an overall perspective view showing a state before pressing of the main body member of the second embodiment.

FIG. 8 is an overall perspective view showing a state before pressing the main body member of the second embodiment.

[Explanation of symbols]

 1A, B Magnet roll shaft body 11-14 Shaft 2 Shaft member 21-25 Outer side surface 26-28 Inner side surface 29 Opening portion 31-39 Permanent magnet 41 Main body member 411 Positioning protrusion 412 Locking portion 413 Hole 414 Claw 415 Claw 416 Long hole 42 Lid body 420 Tip 421 Leg portion 422 Contact surface 423 Convex portion 424 Claw 425 Claw 426 Abutting portion 5 Sleeve 6 Shaft member 61-64 Outer side surface 65-67 Inner side surface 68 Opening portion 71 Body member 711 Positioning protrusion 712 Stop 713 Hole 714 Claw 715 Claw 716 Long Hole 717 End 718 Claw 719 Engagement Part 72 Lid 721 Leg 722 Contact Surface 723 Convex 724 Claw 725 Claw 726 Side End 727 Claw 728 Engagement Recess

Claims (6)

[Claims] 1. A shaft body for a magnet roll, comprising a shaft member having a plurality of flat surfaces, to which permanent magnets are fixed, and a shaft fixed to an end portion of the shaft member. The member includes a main body member having three or more side surfaces formed by press molding, and a lid that covers an open portion formed as a result of press molding of the main body member, and the cross-sectional shape of the shaft member is closed. A shaft body for a magnet roll, which has a polygonal shape. 2. The lid body has a contact surface that contacts an inner side surface of the body member adjacent to the opening, and an inner side surface that contacts the contact surface of the body member.
A convex portion provided on any one of the contact surfaces, and a space provided on the other for accommodating the convex portion and restricting the movement of the accommodated convex portion, the convex portion and the The magnet roll shaft body according to claim 1, wherein a plurality of spaces are provided at predetermined intervals in the axial direction. 3. The shaft body for a magnet roll according to claim 2, wherein the lid body further has a leg portion whose tip is in contact with an inner surface of the main body member. 4. The magnet roll according to claim 3, further comprising an abutting portion formed on the end side of the convex portion formed at the most end and abutting on the shaft, in the lid body. Shaft. 5. The magnet roll shaft body according to claim 2, wherein a surface of the lid body facing the main body member is in contact with an end portion of the open portion of the main body member. 6. The magnet roll according to claim 1, wherein the main body member and the lid body have a projection for positioning the permanent magnet, which is formed integrally with the main body member and the lid body. Shaft.