阅读说明：本技术 辊以及图像形成装置 (Roller and image forming apparatus ) 是由 荻岛和也 于 2019-09-05 设计创作，主要内容包括：在辊及图像形成装置中,与不在轴的安装环状构件的部分设置固定部,且不在环状构件设置被固定于所述固定部的被固定部的情况相比,抑制因经时等的因素导致经由环状构件与弹性层之间产生的间隙发生放电的现象。辊(6)包括：导电性的轴(61)；弹性层(62),设于轴(61)；以及非导电性的环状构件(64),以与所述弹性层的端面(62e)接触的状态,安装于轴(61)中的从弹性层的轴方向(D)的两端面(62e)突出的两端部(61a、61b)中的至少一者,在轴(61)的两端部(61a、61b)中的安装环状构件(64)的部分,设有对环状构件(64)的安装位置进行固定的固定部(71),在环状构件(64)的内周面,设有被轴(61)的固定部(71)所固定的被固定部(73)。(In the roller and the image forming apparatus, compared with the case that the fixing part is not arranged on the part of the shaft where the annular component is installed and the fixed part fixed on the fixing part is not arranged on the annular component, the phenomenon that the discharge is generated through the gap between the annular component and the elastic layer due to the factors such as time is inhibited. The roller (6) comprises: a conductive shaft (61); an elastic layer (62) provided on the shaft (61); and a nonconductive annular member (64) that is attached to at least one of both end portions (61a, 61b) of the shaft (61) that protrude from both end surfaces (62e) of the elastic layer in the axial direction (D) in a state of being in contact with the end surface (62e) of the elastic layer, wherein a fixing portion (71) that fixes the attachment position of the annular member (64) is provided at a portion of the shaft (61) at which the annular member (64) is attached, and a fixed portion (73) that is fixed by the fixing portion (71) of the shaft (61) is provided on the inner circumferential surface of the annular member (64).)

1. A roller, comprising:

a conductive shaft;

an elastic layer disposed on the shaft; and

a non-conductive annular member attached to at least one of both end portions of the shaft protruding from both end surfaces of the elastic layer in the axial direction in a state of being in contact with the end surface of the elastic layer,

fixing portions for fixing the mounting positions of the annular members in the axial direction are provided at portions where the annular members are mounted, of both end portions of the shaft,

a fixed portion to be fixed by the fixing portion of the shaft is provided at a portion of an inner peripheral surface of the annular member in an axial direction.

2. The roller of claim 1, wherein

The portion of the inner peripheral surface of the annular member other than the portion where the fixed portion is formed is configured as a press-fitting portion that is press-fitted to an end portion of the shaft.

3. The roller of claim 1, wherein

The portions of both ends of the shaft to which the annular members are attached are two-step stepped portions including a small diameter portion and a large diameter portion,

the annular member is a two-stage member having a small diameter portion and a large diameter portion, the small diameter portion and the large diameter portion being attached to the small diameter portion and the large diameter portion of the stepped portion of the shaft, respectively,

the fixing portion is provided at a small diameter portion of the stepped portion of the shaft portion,

the fixed portion is provided on an inner peripheral surface of the small diameter portion of the annular member.

4. The roller of claim 1, wherein

The portions of both ends of the shaft to which the annular members are attached are two-step stepped portions including a small diameter portion and a large diameter portion,

the annular member is a two-stage member having a small diameter portion and a large diameter portion, the small diameter portion and the large diameter portion being attached to the small diameter portion and the large diameter portion of the stepped portion of the shaft, respectively,

the fixing portion is provided on the large diameter portion of the stepped portion of the shaft portion,

the fixed portion is provided on an inner peripheral surface of the large diameter portion of the annular member.

5. The roller of claim 3, wherein

The large diameter portion of the annular member is configured to be press-fitted to a press-fitting portion of the large diameter portion of the shaft.

6. The roller of claim 4, wherein

The small diameter portion of the annular member is configured to be press-fitted to a press-fitting portion of the small diameter portion of the shaft.

7. The roller according to any one of claims 1 to 6, wherein

The fixed portion is configured as a concave portion, and the fixed portion is configured as a convex portion fitted into the concave portion.

8. The roller according to any one of claims 1 to 6, wherein

The annular member has an end surface in contact with the elastic layer, and a protruding portion inserted into the end surface of the elastic layer is provided.

9. An image forming apparatus includes:

a roller having a conductive shaft, an elastic layer provided on the shaft, and a non-conductive annular member attached to at least one of both end portions of the shaft protruding from both end surfaces in an axial direction of the elastic layer; and

a power supply member for supplying a voltage to the shaft of the roller,

the roller comprises the roller of any one of claims 1 to 8.

Technical Field

The present invention relates to a roller (roll) and an image forming apparatus.

Background

Conventionally, patent document 1 below discloses a technique relating to a roller (roller) or the like in which leakage (leak) is less likely to occur even when a high voltage is applied.

Patent document 1 describes a roller member in which an elastic layer is formed on an outer peripheral surface of a mandrel bar having a protruding portion formed so as to protrude from a range in which the elastic layer is formed toward an end portion in an axial direction, and a non-conductive member formed of a non-conductive material and provided on the protruding portion so as to bite into an end surface of the end portion in the axial direction in the elastic layer, and an image forming apparatus using the roller member as a transfer roller or a transfer counter roller.

[ Prior art documents ]

[ patent document ]

Patent document 1: japanese patent laid-open publication No. 2017-9985

Disclosure of Invention

[ problems to be solved by the invention ]

The invention provides a roller and an image forming apparatus using the same, the roller is provided with at least an elastic layer on a conductive shaft which can be supplied with a voltage capable of generating discharge, and is provided with a non-conductive annular component, the non-conductive annular component is mounted on an end part protruding from the end part of the elastic layer in the shaft direction in a state of contacting with the end surface of the elastic layer, in the roller, compared with a case that a fixing part is not arranged on the part of the shaft where the annular component is mounted, and a fixed part fixed on the fixing part is not arranged on the annular component, the phenomenon of generating discharge through a gap generated between the annular component and the elastic layer due to time and other factors can be inhibited.

[ means for solving problems ]

The roller of the present invention (a1) is, as described in claim 1, provided with:

a conductive shaft;

an elastic layer disposed on the shaft; and

a non-conductive annular member attached to at least one of both end portions of the shaft protruding from both end surfaces of the elastic layer in the axial direction in a state of being in contact with the end surface of the elastic layer,

fixing portions for fixing the mounting positions of the annular members in the axial direction are provided at portions where the annular members are mounted, of both end portions of the shaft,

a fixed portion to be fixed by the fixing portion of the shaft is provided at a portion of an inner peripheral surface of the annular member in an axial direction.

The roller of the invention (a2) is the roller of the invention a1, wherein a portion of the inner circumferential surface of the annular member other than the portion where the fixed portion is formed is configured as a press-fitting portion that is press-fitted to an end portion of the shaft.

The roller according to the invention (A3) is the roller according to the invention a1, wherein the portion of the shaft at the both ends to which the annular member is attached is a two-step stepped portion including a small diameter portion and a large diameter portion, the annular member is a two-step member having a small diameter portion and a large diameter portion, the small diameter portion and the large diameter portion are attached to the small diameter portion and the large diameter portion of the stepped portion of the shaft, respectively, the fixing portion is provided at the small diameter portion of the stepped portion of the shaft portion, and the fixed portion is provided at the inner peripheral surface of the small diameter portion of the annular member.

The roller according to the invention (a4) is the roller according to the invention a1, wherein the portion of the shaft at the both ends to which the annular member is attached is a two-step stepped portion including a small diameter portion and a large diameter portion, the annular member is a two-step member having a small diameter portion and a large diameter portion, the small diameter portion and the large diameter portion are attached to the small diameter portion and the large diameter portion of the stepped portion of the shaft, respectively, the fixing portion is provided on the large diameter portion of the stepped portion of the shaft portion, and the fixed portion is provided on the inner peripheral surface of the large diameter portion of the annular member.

The roller of the invention (a5) is the roller of the invention A3, wherein the large diameter portion of the annular member is configured to be press-fitted to a press-fitting portion of the large diameter portion of the shaft.

The roller according to invention (a6) is the roller according to invention a4, wherein the small diameter portion of the annular member is configured to be press-fitted into a press-fitting portion of the small diameter portion of the shaft.

The roller of the invention (a7) is the roller according to any one of the inventions a1 to a6, wherein the fixed portion is configured as a concave portion, and the fixed portion is configured as a convex portion fitted into the concave portion.

The roller of the invention (A8) is the roller according to any one of the inventions a1 to a6, wherein, at an end surface of the annular member that is in contact with the elastic layer, a protruding portion that is inserted into the end surface of the elastic layer is provided.

Further, an image forming apparatus according to (B) of the present invention includes: a roller having a conductive shaft, an elastic layer provided on the shaft, and a non-conductive annular member attached to at least one of both end portions of the shaft protruding from both end surfaces in an axial direction of the elastic layer; and a power supply member for supplying a voltage to the shaft of the roller,

the roller comprises the roller of any one of inventions a1 to A8.

[ Effect of the invention ]

According to the roller of invention a1, as compared with a case where the fixing portion is not provided at the portion of the shaft to which the annular member is attached and the fixed portion fixed to the fixing portion is not provided at the annular member, it is possible to suppress the occurrence of discharge through the gap between the annular member and the elastic layer due to factors such as time.

According to the roller of invention a2, as compared with a case where a portion other than a portion where a fixed portion is formed in the inner circumferential surface of the annular member is not configured as a press-fit portion, it is possible to more reliably suppress a phenomenon in which discharge occurs via a gap between the annular member and the elastic layer due to factors such as time.

According to the roller of invention a3, the two-stage annular member can be attached in close contact with the elastic layer, and the occurrence of the discharge can be more reliably suppressed.

According to the roller of invention a4, the two-stage annular member can be attached in close contact with the elastic layer, and the occurrence of the discharge can be more reliably suppressed.

According to the roller of invention a5, the two-stage annular member can be attached in close contact with the elastic layer more stably, and the occurrence of the discharge can be suppressed more reliably.

According to the roller of invention a6, the two-stage annular member can be attached in close contact with the elastic layer more stably, and the occurrence of the discharge can be suppressed more reliably.

According to the roller of invention a7, the fixing portion and the fixed portion can be easily provided, compared to a case where the fixing portion is not a concave portion and the fixed portion is not a convex portion.

According to the roller of invention A8, the generation of the discharge can be more reliably suppressed than in the case where the annular member is not provided with the protruding portion inserted into the end face of the elastic layer.

According to the image forming apparatus of invention B, as compared with the case where the fixing portion is not provided in the portion of the shaft of the roller to which the ring-shaped member is attached, and the fixed portion fixed to the fixing portion is not provided in the ring-shaped member of the roller, it is possible to suppress the occurrence of discharge through the gap generated between the ring-shaped member of the roller and the elastic layer due to factors such as time, and also suppress the occurrence of secondary failure due to the discharge.

Drawings

Fig. 1 is a schematic diagram showing a configuration of an image forming apparatus according to embodiment 1.

Fig. 2 is a schematic diagram showing a part (mainly, an image forming apparatus) of the image forming apparatus of fig. 1.

Fig. 3 is a schematic view showing another part (mainly, a part of the secondary transfer) of the image forming apparatus of fig. 1.

Fig. 4(a) is a schematic view showing the entire secondary transfer roller to which the roller of embodiment 1 is applied, and fig. 4(B) is a schematic view showing one end of the roller of fig. 4(a) in an enlarged manner.

Fig. 5(a) is a schematic view showing a state where a holder or the like at one end of the secondary transfer roller of fig. 4(a) and 4(B) is removed, and fig. 5(B) is a perspective view showing one end of the roller of fig. 5 (a).

Fig. 6(a) is a perspective view showing one end of the shaft in the secondary transfer roller of fig. 5(a) and 5(B), and fig. 6(B) is a perspective view showing the annular member in the secondary transfer roller of fig. 5(a) and 5 (B).

Fig. 7(a) and 7(B) are schematic diagrams showing respective states when the ring-shaped member of fig. 6(B) is viewed from different directions.

Fig. 8(a) is a schematic view showing one end portion of the shaft in the secondary transfer roller of fig. 5(a) and 5(B), and fig. 8(B) is a schematic cross-sectional view of the annular member of fig. 7(B) taken along the line Q-Q.

Fig. 9(a) is a partial cross-sectional view showing a state in which the annular member at one end portion of the secondary transfer roller of fig. 5(a) and 5(B) is attached, and fig. 9(B) is a vertical cross-sectional view of one end portion of the secondary transfer roller of fig. 5(a) and 5 (B).

Fig. 10(a) and 10(B) are cross-sectional views each showing a configuration of one end portion of the secondary transfer roller according to embodiment 2.

Fig. 11(a) and 11(B) are schematic diagrams showing a state in which the annular member in the secondary transfer roller of fig. 10(a) and 10(B) is viewed from different directions.

Fig. 12(a) and 12(B) are views showing the secondary transfer roller according to embodiment 3, fig. 12(a) is a schematic view showing one end portion of a shaft in the secondary transfer roller, and fig. 12(B) is a schematic cross-sectional view showing an annular member in the secondary transfer roller.

Fig. 13 is each sectional view showing a configuration of one end portion of the secondary transfer roller according to embodiment 4.

Fig. 14(a) is a schematic view showing one end portion of the shaft in the secondary transfer roller of fig. 13, and fig. 14(B) is a schematic cross-sectional view showing an annular member in the secondary transfer roller of fig. 13.

Fig. 15(a) and 15(B) are schematic cross-sectional views showing the structure of the annular member and the state at the time of discharge occurrence in the secondary transfer roller of comparative example 1.

Fig. 16(a) and 16(B) are schematic cross-sectional views showing the structure of the annular member and the state at the time of discharge occurrence in the secondary transfer roller of comparative example 2.

[ description of symbols ]

1: image forming apparatus with a toner supply device

6: roller

15: power supply device (an example of a power supply member)

61: shaft (an example of shaft)

61a, 61 b: two ends of the tube

62: elastic layer

62 e: end face

64: ring-shaped member (an example of a ring-shaped member)

71: groove (an example of a fixed part and a concave part)

73: projection (fixed part and projection example)

75: pressed-in part

80: protrusion (example of inserted protrusion)

351: secondary transfer roller

612: large diameter part of shaft

613: small diameter part of shaft

641: small diameter part of annular member

642: large diameter part of ring member

D: axial direction

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[ embodiment 1]

Fig. 1 shows an image forming apparatus 1 according to embodiment 1. In other drawings including fig. 1, arrows denoted by symbols X, Y, and Z indicate directions of width, height, and depth assumed in the drawings. Further, in fig. 1, 2, and the like, the circle symbol at the portion where the arrows of the symbol X, Y intersect indicates that the direction of the symbol Z is directed vertically downward in the drawing.

< image forming apparatus >

The image forming apparatus 1 is an apparatus that forms an image containing toner as a developer on a sheet 9 as an example of a recording medium by an image forming method such as an electrophotographic method. The image forming apparatus 1 is configured as a printer (printer) that forms an image corresponding to image information input from an external device such as an information terminal or an image reading apparatus, for example.

As shown in fig. 1, the image forming apparatus 1 includes, in an internal space of a housing 10 as an example of an apparatus main body, the following components: an image forming member 2 for forming a toner image as an unfixed image; an intermediate transfer member 3 for temporarily holding and conveying the toner image formed by the image forming member 2 and secondarily transferring the toner image to a sheet 9; a paper feeding member 4 that receives and feeds a sheet of paper 9 to be fed to the secondary transfer position of the intermediate transfer member 3; and a fixing member 5 for fixing the toner image secondarily transferred by the intermediate transfer member 3 to the sheet 9.

The frame 10 is a structure assembled by various materials such as support members and exterior materials into a desired structure and shape. The frame 10 has a discharge housing portion 12 formed in a part of an upper surface thereof, and the discharge housing portion 12 houses the sheets 9 discharged after the images are formed in a stacked state. A chain line of one dot in fig. 1 indicates a main conveyance path when the sheet 9 is conveyed in the housing 10.

The image forming means 2 includes, for example, four image forming devices 2Y, 2M, 2C, and 2K, and the four image forming devices 2Y, 2M, 2C, and 2K form toner images of four colors of yellow (Y), magenta (M), cyan (C), and black (K) in a dedicated manner, respectively. The four imaging devices 2(Y, M, C, K) in embodiment 1 are arranged inside the housing 10 shown in fig. 1 in a state inclined to the upper right.

As shown in fig. 1 or 2, each of the four image forming apparatuses 2(Y, M, C, K) includes a photosensitive drum 21 as an example of an image holding member, and the photosensitive drum 21 rotates in a direction indicated by an arrow.

Further, the image forming apparatus 2(Y, M, C, K) includes the following devices disposed around the photosensitive drum 21: a charging device 22 for charging the image holding area of the photosensitive drum 21; an exposure device 23, which is an example of an exposure means, for forming an electrostatic latent image by exposing the charged image holding area of the photosensitive drum 21 in accordance with image information; a developing device 24(Y, M, C, K) for developing the electrostatic latent image formed on the image forming surface of the photosensitive drum 21 with toner of a corresponding color to form a toner image; and a1 st cleaning device 26 for cleaning the image forming surface of the photosensitive drum 21.

In fig. 1, for convenience, all of the symbols 21 to 24 and 26 are described for the black (K) image forming device 2K, and only a part of the other color image forming devices 2Y, 2M and 2C is described, and the rest is omitted.

The charging device 22 is a charging device of a contact charging system, that is, a charging roller 221 as an example of a contact charging member is used, and a necessary charging voltage is supplied from the power supply device 15 to the charging roller 221 to perform charging. Reference numeral 223 in fig. 2 is a cleaning roller which comes into contact with the charging roller 221 to clean the roller surface.

The developing device 24(Y, M, C, K) has substantially the same configuration, except that the toner contained in the developer contained in the main body (housing) 241 is different in color from the toner contained in the developer contained in the main body (housing) in any of the four colors (Y, M, C, K). That is, as shown in fig. 2, the developing device 24(Y, M, C, K) is configured by arranging, in its main body 241, a developing roller 242, an agitating member 243 such as an auger (auger), and a layer thickness regulating member 244, wherein the developing roller 242 holds and rotationally conveys the developer so as to pass through the developing process region facing the photosensitive drum 21, the agitating member 243 rotationally conveys the developer in the main body 241 while agitating the developer so as to supply the developer to the developing roller 242, and the layer thickness regulating member 244 regulates the amount (thickness) of the developer held by the developing roller 242. The developing roller 242 is supplied with a required developing voltage from the power supply device 15 and performs development.

The intermediate transfer member 3 is disposed inside the housing 10 above the image forming apparatus 2(Y, M, C, K) serving as the image forming member 2.

The intermediate transfer member 3 is configured by arranging apparatuses such as an intermediate transfer belt 31, a primary transfer device 33, a secondary transfer device 35, and a2 nd cleaning device 36, the intermediate transfer belt 31 rotates after receiving and holding toner images formed by the image forming devices 2(Y, M, C, K) by primary transfer to convey them to a position where they are secondarily transferred to the paper 9, the primary transfer device 33 primarily transfers the toner images formed on the photosensitive drums 21 of the image forming devices 2(Y, M, C, K) to an image holding area on the outer peripheral surface of the intermediate transfer belt 31, the secondary transfer device 35 secondarily transfers the toner image on the intermediate transfer belt 31 to the paper 9, and the 2 nd cleaning device 36 cleans the outer peripheral surface of the intermediate transfer belt 31.

The intermediate transfer belt 31 is rotated in the direction indicated by the arrow while sequentially passing through the photosensitive drums 21 of the image forming apparatus 2(Y, M, C, K), the secondary transfer device 35, and the like in a state of being stretched over a plurality of support rollers 32a to 32 d. The backup roller 32a is configured as a drive roller, and the backup roller 32b is configured as a secondary transfer opposing roller.

As shown in fig. 1 or 2, the primary transfer device 33 is applied to a contact transfer type transfer device that uses a primary transfer roller 331 as an example of a contact transfer member and performs primary transfer by supplying a primary transfer voltage necessary for primary transfer from a power supply device 15 to the primary transfer roller 331.

Further, as shown in fig. 1 or 3, the secondary transfer device 35 is applied to a transfer device of a contact transfer method in which a secondary transfer roller 351, which is an example of a contact transfer member, is used, and a necessary secondary transfer voltage is supplied from a power supply device 15 to the secondary transfer roller 351 to perform secondary transfer.

The sheet feeding unit 4 is configured by arranging apparatuses such as a sheet container 41 for containing the sheets 9 and a feeder 43 for feeding the sheets 9 one by one from the sheet container 41. The sheet 9 fed from the sheet feeding member 4 is conveyed to a secondary transfer position between the intermediate transfer belt 31 and the secondary transfer device 35 in the intermediate transfer member 3 via a sheet feeding conveyance path including a sheet conveyance roller 45, a conveyance guide (guide) not shown, and the like.

The fixing member 5 is disposed above the secondary transfer position of the intermediate transfer member 3. The fixing member 5 is configured by disposing devices such as a rotating body 51 for heating and a rotating body 52 for pressurizing in the inner space of the housing 50. The sheet 9 fed from the fixing member 5 after fixing is conveyed to the discharge accommodating unit 12 via a discharge path including a sheet conveying roller 47, a conveying guide not shown, and the like.

< Secondary transfer roller >

The secondary transfer roller 351 is configured as an example of the roller 6 of the present invention.

As shown in fig. 3 to 5(a) and 5(B), the secondary transfer roller 351 includes the following structure: a shaft 61; an elastic layer 62 and a surface layer 63 provided on the shaft 61; and annular members 64, which are an example of an annular member, attached to both end portions 61a, 61b of the shaft 61, which protrude from both end surfaces 62e of the elastic layer 62 in the axial direction D, respectively, in a state of being in contact with the end surfaces 62e of the elastic layer 62.

In fig. 4(a) and 4(B), reference numeral 65 denotes a non-conductive holder used when the secondary transfer roller 351 is mounted on a mounting portion such as a support frame (not shown) as a whole while holding both end portions 61a and 61B of the shaft 61. Further, reference numeral 66 denotes a secondary gear including a gear for receiving the rotational power transmitted from the not-shown rotational driving device by the secondary transfer roller 351 and a relay gear for relaying the rotational power to a rotating component other than the secondary transfer roller 351, and reference numeral 67 denotes a nonconductive cover for covering a gap between the masking holder 65 and an annular member (64) described later.

Bearings for rotatably supporting both end portions 61a, 61b of the shaft 61 are disposed in the two holders 65, and a power feeding member, not shown, which is in contact with the shaft 61 and supplies a secondary transfer voltage from the power feeding device 15 is disposed in the holder 65 on one side of the cover 67. The power feeding member is in a state of being in contact with and connected to a power transmitting member from the power feeding device 15 when the secondary transfer roller 351 is attached.

The shaft 61 is a substantially cylindrical member having a desired diameter and length as a whole, and is made of a conductive material such as stainless steel (SUS).