JPH11310349A - High friction roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high friction roller wherein the paper quality of a sheet to be carried is not a problem, the influence of paper powders is limited over a long term, wearing is limited, durability is provided and paper feeding accuracy is high. SOLUTION: Since a high friction layer 4 uses, as a material, an adhesive material 6 where wear resistant particles 5 are dispersed nearly uniformly, sharp contact is made with a sheet by the dispersed particles, high friction resistance is stably provided not only for ordinary paper but also for a smooth sheet such as a glossy film, and carrying accuracy is stable without being affected by paper quality. Further, since the high friction layer 4 is made of the wear resistance particles 5 having nearly uniform particle sizes, a roller diameter is uniform not only in the longitudinal direction but also the circumferential direction of a roller surface 3, and paper feeding accuracy is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sheet, for example,
The present invention relates to a high friction roller used in a printer or the like for conveying various sheets such as plain paper, coated paper, OHP (overhead projector) sheets, glossy paper, glossy film, and the like.

[0002]

2. Description of the Related Art As a prior art of this kind of high friction roller, there is one disclosed in Japanese Patent Laid-Open Publication No. 1-256438. This high friction roller constitutes a paper feed roller for a paper feed device, and is formed by coating an outer peripheral surface of a roller body made of rubber, synthetic resin, metal, or the like with silicone rubber. Due to the high frictional resistance of the coating layer made of the silicone rubber, the paper can be held and fed without slipping.

[0003]

However, the coating layer made of silicone rubber can stably exhibit a high frictional resistance to plain paper and the like, and can be transported with high precision. Such a sheet is inadvertently slippery during conveyance, resulting in poor conveyance accuracy.
That is, there is a problem that the conveyance accuracy is easily influenced by the paper quality. Further, even with plain paper, in the long term, paper powder gradually adheres to the surface of the coating layer made of silicone rubber, and as a result, there is a problem that the frictional resistance gradually decreases, and the conveyance accuracy decreases.

An object of the present invention is to provide a high friction roller which is not affected by the paper quality of a sheet to be conveyed, is not easily affected by long-term paper dust, is less likely to be worn, is durable, and has high paper feeding accuracy. It is in.

[0005]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 of the present application is directed to a high friction roller having a high friction layer adhered to a roller surface, wherein the high friction layer has a particle size. It is characterized in that it comprises an adhesion layer in which abrasion-resistant particles substantially uniformly arranged are substantially uniformly dispersed.

According to the present invention, the high friction layer is made of an adhesive material in which abrasion-resistant particles are substantially uniformly dispersed, so that the dispersed particles can make an acute contact with a sheet, and a plain paper can be obtained. High frictional resistance can be stably exerted not only on the sheet or the like but also on a smooth sheet such as a glossy film. Therefore, the transport accuracy is stable regardless of the paper quality. Further, since the paper powder hardly adheres to the particle portion and peels off immediately if it arrives, the frictional resistance does not decrease over the long term, and the conveyance accuracy can be maintained high. Furthermore, since the high friction layer according to the present invention is formed by substantially uniformly dispersing wear-resistant particles having a substantially uniform particle diameter, the roller diameter becomes uniform in the longitudinal direction of the roller surface as well as in the circumferential direction. , Paper feeding accuracy can be improved.

According to a second aspect of the present invention, there is provided a high-friction roller having a high-friction layer adhered to a roller surface, wherein the high-friction layer is formed around a particle diameter A [μm] having a selected particle diameter. It is characterized by comprising an adhesion layer in which abrasion-resistant particles arranged in a range of ± 20% are substantially uniformly dispersed. According to the present invention, the same functions and effects as those of the first aspect are obtained. That is, since the particle size of the wear-resistant particles is aligned within a range of ± 20% around the selected particle size A [μm], the uniformity of the roller diameter can be easily and sufficiently secured, and the paper Feeding accuracy can be improved.

According to a third aspect of the present invention, in the first aspect of the invention, the wear-resistant particles are made of a ceramic such as alumina or silicon carbide. Since the ceramic particles are used in this manner, the conveyance accuracy is not affected by the paper quality and the effect of being not affected by the paper dust can be obtained more reliably, and based on the property of being hard and less susceptible to plastic deformation. The durability is further improved. Moreover, it is inexpensive.

According to a fourth aspect of the present invention, in the first aspect of the invention, the distribution of the wear-resistant particles on the surface of the high friction layer is 20% to 20%.
It is characterized by being 80%. Thus, it is possible to reliably prevent the occurrence of a layered (dense) state of the particles based on the distribution density being too large and the shortage of the projections due to the particles based on the distribution density being too small and the reduction of the frictional resistance due to the shortage.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a high friction roller according to the present invention, and FIG. 2 is an enlarged sectional view of a main part showing a use state of a sheet conveying device in which the high friction roller is assembled. As shown in these figures, the high friction roller 1 has a high friction layer 4 adhered to the surface 3 of the roller 2. The material of the roller 2 includes metal, rubber, plastic (including elastomer), and the like. In this embodiment, the material is a highly rigid metal.

The high friction layer 4 is made of an adhesive material 6 in which abrasion-resistant particles 5 are substantially uniformly dispersed, as shown in FIG. Unevenness is formed on the surface by the dispersion of. Abrasion resistant particles 5
By using a material having a relatively sharp and pointed shape, unevenness with higher friction is obtained. Furthermore, wear-resistant particles 5
The roller is formed such that the particle diameters thereof are substantially uniform, and the roller diameter is uniform both in the longitudinal direction of the roller surface and in the circumferential direction.

In the present embodiment, as shown in FIGS. 1 and 2, the roller surface 3 is provided with abrasion-resistant particles 5 in the radial direction.
Are almost non-overlapping, and one is present, and are dispersed at a slight distance in the longitudinal direction. That is, it substantially corresponds to one in which the wear-resistant particles 5 are arranged one by one on the roller surface 3. Of course, this alignment does not mean that it is strictly, but that it is almost so. Therefore, the diameter of the roller is more abrasion-resistant particles 5 than the diameter of the surface 3
Therefore, if there is a large variation in the particle size, the variation in the diameter of the roller itself also becomes large. Therefore, in the present invention, the particle sizes are made uniform. The present inventors will make the roller diameter uniform in the circumferential direction and in the longitudinal direction if the particle size of the wear-resistant particles 5 is aligned within a range of ± 20% around the selected particle size A [μm]. Has confirmed that there is almost no problem.

The material of the wear-resistant particles 5 is made of a ceramic such as alumina or silicon carbide in this example. The selected particle size A is selected from the range of 20 μm to 70 μm, and is 50 μm in the present embodiment. Selective particle size A from 20 μm to 7
If the particle size in this range is selected from the range of 0 μm, the selected particle size A is not too large, so that the sheet can be reliably prevented from being damaged, and because it is not too small, paper dust on the surface can be reliably prevented. This is because the required friction coefficient can be easily obtained. Furthermore, the distribution density on the surface of the high friction layer 4 is formed to be 20% to 80%.

The adhesive 6 is used to disperse the abrasion-resistant particles 5 and firmly adhere to the surface 3 of the roller 2 to integrate them, and can be appropriately selected from this viewpoint. In this example,
Adhesive in the sense of including paint is used. Specifically, examples of the adhesive 6 include a thermosetting epoxy adhesive, a room temperature curing acrylic adhesive, a UV curing polyurethane adhesive, and a two-component reactive epoxy adhesive.

Here, an example of a method for manufacturing the high friction roller 1 shown in FIG. 1 is described. The adhesive 6 in a fluid state in which the wear-resistant particles 5 are mixed is directly sprayed on the roller surface 3 and dried. It is formed by having When the adhesive used as the adhesive 6 is a heat-curable adhesive, the adhesive 6 is firmly fixed to the surface 3 of the roller 2 by heat treatment (for example, at 160 ° C. for 20 minutes) to be integrated. I do. When a room temperature-curable or UV-curable adhesive is used, a curing process suitable for the adhesive is employed.

As shown in FIG. 2, the sheet conveying apparatus having the high friction roller 1 assembled therein is used for a printer or the like. The high friction roller 1 is used as a driving roller and forms a pair with a driven roller 10. ing. S is a sheet. The driving roller 1 is driven to rotate, for example, in the direction of arrow f by driving means (not shown). The driven roller 10 has its shaft 11 urged toward the drive roller 1 by urging means (not shown). With this urging force, the driven roller 10 is pressed against the drive roller 1 and driven. Accordingly, when the sheet S is supplied between the driving roller 1 and the driven roller 10, the sheet S is nipped by the driving roller 1 and the driven roller 10 and conveyed in the direction of arrow a as shown in the figure. become.

The driven roller 10 is formed by providing a coating layer 13 of a low friction material on the surface of an elastic roller 12 made of rubber or the like. In this embodiment, it is composed of a fluorine coating layer and has a thickness of 5 μm to 20 μm. 20μ
When the distance exceeds m, smooth elastic deformation of the elastic roller 12 itself is hindered. On the other hand, when the distance is less than 5 μm, the friction coefficient of the driven roller 10 with respect to the sheet S cannot be reduced. The hardness of the elastic roller 12 is 60 ° to 95 ° in rubber hardness. High hardness (9
5 °), the width (length in the sheet conveying direction) of the nipping portion (so-called nip portion) N with respect to the sheet S when pressed against the drive roller 1 becomes insufficient, and the sheet feeding operation becomes unstable. Conversely, if the hardness is low (less than 60 °), the driven roller 10 is excessively deformed and the sheet S
This is because the bite becomes unstable.

Next, the operation of the above embodiment will be described. According to the above-described embodiment, the high friction layer 4 is made of the adhesive material 6 in which the wear-resistant particles 5 having a substantially uniform particle size are dispersed almost uniformly, and thus is shown in FIG. Thus, the dispersed particles 5 can make sharp contact with the sheet S, and can stably exhibit high frictional resistance not only on plain paper and the like but also on a smooth sheet S such as a glossy film. At the same time, the roller diameter can be made uniform in the circumferential direction and the longitudinal direction. That is, since the roller diameter becomes uniform, the paper feed accuracy is improved, and the paper feed accuracy is not affected by the paper quality due to the acute contact. Further, even when plain paper or the like is continuously transported, the generated paper dust hardly adheres to the portion of the particles 5, and even if it arrives, it is immediately peeled off. Therefore, even if paper dust is generated, the frictional resistance does not decrease and the conveyance accuracy can be maintained high.

Further, those using ceramic particles such as alumina and silicon carbide as the wear-resistant particles 5 have more excellent durability based on the properties of the ceramics such that they are hard and not easily plastically deformed. The effect that the conveyance accuracy is not affected by the paper quality and that the paper is not affected by the paper dust is further ensured. In addition, the distribution density of the wear-resistant particles 5 on the surface of the high friction layer is 20% to 80%.
Since the distribution density is not too high, it is possible to reliably prevent the formation of a layered (dango) state of the particles, and since it is not too low, the number of contact points between the particles and the sheet S can be sufficiently ensured, so that the necessary frictional resistance can be ensured. Can be obtained.

FIG. 3 shows the high friction roller 1 according to the present invention.
FIG. 1 is a schematic side view illustrating an example of an ink jet printer using a printer. This ink jet printer includes a sheet conveying device 30 including a high friction roller 1 as a driving roller and a driven roller 10, and a sheet S
Feeding device 40 for supplying the sheet, and sheet conveying device 30
A print head 50 that forms an image (including characters) by discharging ink onto the surface of the sheet S conveyed by the printer, and a discharge roller pair 60 that discharges the printed sheet S.
Further, a main frame 70 for mounting these devices and the like, a first sub-frame 71, a second sub-frame 72, and a pair of side frames (not shown) are provided.

A driving roller (high friction roller) 1 of the sheet conveying device 30 is supported by a side frame (not shown), and is driven by an appropriate driving means. The driven roller 10 is supported by a support mechanism to be described later such that the driven roller 10 can be driven to rotate in a slightly pressed state with respect to the driving roller 1.

The sheet supply device 40 includes a supply roller 41
A hopper (not shown) for urging the sheet S toward the supply roller 41, and a separation pad 42 for pressing the sheet S between the supply roller 41 and separating the sheet S. A plurality of sheets S are set in the hopper,
The sheet S is held in such a manner that the sheet S is pressed by a hopper toward a supply roller 41 that rotates once, is separated by a separation pad 42, and is fed only to the sheet conveying device 30. Has become. The supplied sheet S is guided toward the sheet conveying device 30 by a lower guide 80 attached to the first sub-frame 71 and an upper guide 90 attached to the main frame 70.

The print head 50 is mounted on a carriage 51. The carriage 51 is a main frame 70
And the carriage guide shaft 52,
It is mounted movably in the direction perpendicular to the paper.
An ink tank 53 is mounted on the carriage 51. The printing operation is performed in such a manner that one line of printing is performed by ejecting ink from the print head 50 while the carriage 51 moves in a direction orthogonal to the paper surface. At 30, the sheet S is conveyed at a predetermined pitch (normal line spacing), and these operations are repeated. Reference numeral 54 denotes a sheet for supporting and guiding the lower surface of the sheet S, and the sheet S and the print head 50.
Is a base member that defines the distance between the base member. Discharge roller pair 60
Is composed of a driving roller 61 and a driven star wheel 62 urged toward the driving roller 61, and discharges the printed sheet S out of the apparatus. The driven star wheel 62 is attached to the second sub-frame 72.

Next, the driven roller 1 of the sheet conveying device 30
The support structure No. 0 will be described with reference to FIGS. As shown in these figures, the driven roller 10 is rotatably supported by the distal end of the upper guide 90. The upper guide 90 has a substantially plate shape as a whole, and
The base 91 is rotatably attached to the support shaft 20 as shown in FIG. The support shaft 20 has a hook portion 7 bent at the lower end of the main frame 70.
It is supported so as to be sandwiched from above and below by 3, 74. The left side of the support shaft 20 in FIG. 4 is in contact with the back surface (the right side surface in FIG. 4) 75 of the main frame 70. As a result, the support shaft 20 is arranged parallel to the axis of the drive roller 1 of the sheet conveying device 30.

As shown in FIG. 5, the driven roller 10
A shaft 11 and a pair of driven rollers 10 ′, 10 ′ mounted on the shaft 11 symmetrically with respect to the axial center portion 11 a of the shaft 11 and avoiding the central portion 21 a. I have. On the other hand, elongated holes 92, 92 which support both ends 11b, 11b of the shaft 11 and extend in the vertical direction (direction toward the drive roller 1) are provided at the distal end of the upper guide 90.
A pressing portion 93 that is in contact with the central portion 11a is formed. The elongated holes 92, 92 are provided at the base 91, that is, the support shaft 20.
Are provided at the same distance from each other.

A torsion spring 100 is mounted on the support shaft 20. One end 101 of the torsion spring 100 is, as shown in FIG.
6, the other end 102 abuts against the pressing portion 93 of the upper guide 90 and urges it toward the drive roller 1. Therefore, the driven roller 10 includes both ends 11 b of the shaft 11,
11b is supported so as to be movable only in the direction of the drive roller 1 and only the central portion 11a of the shaft 11 is urged toward the direction of the drive roller 1;
Is the central portion 1a independently of the support shaft 20 (in a front view)
It can swing around and is pressed against the drive roller 1 along the drive roller 1. Although not shown, in the printer, a plurality of driven rollers 10 having the above-described structure are provided for the driving roller 1 in the axial direction.

Since the elongated holes 92, 92 for supporting both ends 11b, 11b of the shaft 11 are provided at an equal distance from the support shaft 20, the shaft 11 and the support shaft 20 are parallel to each other.
In addition, since the support shaft 20 is pressed against the back surface 75 of the main frame 70 by the torsion spring 100, the parallelism between the support shaft 20 and the driving roller 1 is maintained with high accuracy. The parallelism between the shaft 11 and the axis of the drive roller 1 is maintained with high accuracy.
In particular, since the shaft 11 of the driven roller 10 can swing around the central portion 11a (in a front view) independently of the support shaft 20, the parallelism in the front view is maintained with extremely high precision. Become.

The driven roller 10 has both ends 11b, 11b of the shaft 11 supported so as to be movable only in the direction of the driving roller 1 as described above.
Since only the central portion 11a is urged toward the drive roller 1, the sheet S is evenly pressed against the drive roller 1, and the sheet S is conveyed straight.

[0029]

According to the present invention, since the high-friction layer is made of an adhesive material in which abrasion-resistant particles are substantially uniformly dispersed, the dispersed particles can make an acute contact with a sheet. High friction resistance can be stably exhibited not only on paper and the like but also on a smooth sheet such as a glossy film. Therefore, the transport accuracy is stable regardless of the paper quality. Further, since the paper powder hardly adheres to the particle portion and peels off immediately if it arrives, the frictional resistance does not decrease over the long term, and the conveyance accuracy can be maintained high. Further, since the high friction layer according to the present invention is formed by dispersing the wear-resistant particles having substantially uniform particle diameters substantially uniformly, the roller diameter becomes uniform in the longitudinal direction of the roller surface as well as in the circumferential direction. , Paper feeding accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a high friction roller according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part showing an example of a transport device in which a high friction roller according to the present invention is assembled.

FIG. 3 is a schematic side view showing an ink jet printer in which a high friction roller according to the present invention is assembled.

FIG. 4 is a partially enlarged view of FIG. 3;

FIG. 5 is a perspective view showing an example of a support structure of a driven roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High friction roller 2 Roller 3 Roller surface 4 High friction layer 5 Abrasion resistant particles 6 Adhesive material 10 Follower roller 11 shaft

Claims (4)

[Claims] 1. A high-friction roller having a high-friction layer adhered to a roller surface, wherein the high-friction layer is an adhesion layer in which wear-resistant particles having a substantially uniform particle size are substantially uniformly dispersed. A high-friction roller comprising: 2. A high-friction roller having a high-friction layer adhered to a roller surface, wherein the high-friction layer has a particle size uniform within a range of ± 20% around a selected particle size A [μm]. A high-friction roller comprising an adhesion layer in which abrasion-resistant particles are substantially uniformly dispersed. 3. The high friction roller according to claim 1, wherein the wear-resistant particles are made of a ceramic such as alumina or silicon carbide. 4. The abrasion-resistant particles according to claim 1, wherein a distribution density on the surface of the high friction layer is 20.
% To 80%.