JP2017173749A - Belt conveying device, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress, in a configuration that causes an endless belt to circulate through contact with a driving member, wear of the ends in a rotation axis direction of the belt compared with a configuration that brings the ends in the rotation axis direction of the belt into contact with a surface orthogonal to the rotation axis direction of the belt to prevent a movement in the rotation axis direction of the belt.SOLUTION: A fixing device comprises: an endless belt that is in surface contact with a conveyance target member; a driving member that is in contact with the outer periphery of the belt to drive the belt to circulate; and a conversion member that is in contact with the inner periphery or outer periphery of the belt at the ends in the rotation axis direction to convert a movement in the rotation axis direction of the belt into an inclination with respect to the rotation axis direction of the driving member.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a belt conveyance device, a fixing device, and an image forming apparatus.

  In Patent Document 1, in order to restrict the movement of the endless belt in the rotation axis direction, belt regulating members are provided at both ends of the belt in the rotation axis direction.

JP 2006-051804 A

  In the present invention, in an arrangement in which an endless belt is circulated by contact with a driving member, the end of the belt in the rotation axis direction is brought into contact with a surface orthogonal to the rotation axis direction of the belt to move the belt in the rotation axis direction. The object is to suppress the wear of the end portion of the belt in the direction of the rotation axis, as compared with the configuration to prevent.

  The belt conveyance device according to claim 1, an endless belt that comes into contact with a member to be conveyed on the surface, a driving member that is in contact with an outer periphery of the belt and drives the belt to rotate, and rotation of the belt A conversion member that contacts an inner periphery or an outer periphery of the end portion in the axial direction and converts the movement of the belt in the rotation axis direction into an inclination of the drive member with respect to the rotation axis direction.

  The belt conveying device according to claim 2 is the belt conveying device according to claim 1, wherein the conversion member is viewed in a cross section along the rotation axis direction of the drive member with respect to the rotation axis direction of the drive member. And an inclined portion on which the end of the belt moving in the direction of the rotation axis rides.

  The belt conveyance device according to claim 3 is the belt conveyance device according to claim 2, wherein the inclined portion is disposed upstream of the contact portion between the belt and the driving member in the rotation direction of the belt. It contacts the inner periphery at the end of the belt in the direction of the rotation axis.

  The belt conveyance device according to claim 4 is the belt conveyance device according to claim 2, wherein the inclined portion is disposed downstream of the contact portion between the belt and the drive member in the rotation direction of the belt. It contacts the outer periphery at the end of the belt in the direction of the rotation axis.

  A fixing device according to a fifth aspect includes the belt conveyance device according to any one of the first to fourth aspects, and a heating source disposed inside the driving member or the belt.

The image forming apparatus according to claim 6, an image forming unit that forms an image on a transported member;
The fixing device according to claim 5, wherein an image formed on the transported member by the image forming unit is fixed to the transported member.

  According to the configuration of the belt conveying device according to claim 1, in the configuration in which the endless belt is circulated by contact with the driving member, the end of the belt in the rotation axis direction is a surface orthogonal to the rotation axis direction of the belt. Compared with the configuration in which the movement of the belt in the rotation axis direction is prevented, the wear of the end portion of the belt in the rotation axis direction can be suppressed.

  According to the configuration of the belt conveyance device of the second aspect, the conversion member has a step with respect to the rotation axis direction of the drive member as viewed in a cross section along the rotation axis direction of the drive member. The rotation axis direction can be tilted smoothly.

  According to the configuration of the belt conveyance device of the third aspect, the inclined portion is arranged on the downstream side in the rotation direction of the belt with respect to the contact portion between the belt and the driving member, and contacts the inner circumference at the end portion in the rotation axis direction of the belt. Compared with the configuration, it is possible to suppress wear of the end portion of the belt in the rotation axis direction.

  According to the configuration of the belt conveyance device of the fourth aspect, the inclined portion is disposed on the upstream side in the rotation direction of the belt with respect to the contact portion between the belt and the driving member and is in contact with the outer periphery at the end portion in the rotation axis direction of the belt. As compared with the above, it is possible to suppress wear at the end of the belt in the rotation axis direction.

  According to the configuration of the fixing device of the fifth aspect, the life of the belt is extended as compared with the configuration having no belt conveying device according to any one of the first to fourth aspects.

  According to the configuration of the image forming apparatus of the sixth aspect, power consumption can be suppressed as compared with the configuration having no fixing device according to the fifth aspect.

1 is a configuration diagram illustrating an image forming apparatus according to a first embodiment. 1 is a schematic cross-sectional view illustrating a configuration of a fixing device according to a first embodiment. (A) It is a front view of the conversion member used with the belt conveyance apparatus of 1st Embodiment. (B) It is a BB sectional view of the conversion member of Drawing 3 (A). (C) It is the side view which looked at the conversion member of Drawing 3 (A) in the direction of arrow 3C. FIG. 3 is a front view of the belt of FIG. 2 as viewed from a direction orthogonal to the rotation direction. FIG. 5 is an enlarged view of a portion indicated by an arrow 5 in FIG. 4, showing a state in which the belt has moved to one side in the rotation axis direction. FIG. 7 is an enlarged view of a portion indicated by an arrow 6 in FIG. 4, showing a state where the belt has moved to the other side in the rotation axis direction. It is a front view of the modification of the belt conveying apparatus of 1st Embodiment. FIG. 7 shows a state where the belt has moved to one side in the rotation axis direction. It is a front view of the other modification of the belt conveyance apparatus of 1st Embodiment. FIG. 9 shows a state where the belt has moved to one side in the rotation axis direction. It is a graph which shows the relationship between the moving amount | distance of the rotating shaft direction of a belt, and time in the belt conveying apparatus of Comparative Examples 1-3. It is a graph which shows the relationship between the moving amount | distance of the rotating shaft direction of the belt in the belt conveying apparatus of Examples 1-3, and time.

  A belt conveyance device, a fixing device, and an image forming apparatus according to an embodiment of the present invention will be described.

<First Embodiment>
FIG. 1 shows an image forming apparatus 10 according to the first embodiment. In the following description, the direction indicated by the arrow Y in FIG. 1 is the apparatus height direction, and the direction indicated by the arrow X is the apparatus width direction. In addition, a direction (indicated by Z) orthogonal to each of the apparatus height direction and the apparatus width direction is defined as an apparatus depth direction. Then, when the image forming apparatus 10 is viewed from the front, the apparatus height direction, the apparatus width direction, and the apparatus depth direction are described as a Y direction, an X direction, and a Z direction. Further, when it is necessary to distinguish one side and the other side in the X direction, the Y direction, and the Z direction, when the image forming apparatus 10 is viewed from the front, the upper side is the Y side, the lower side is the -Y side, and the right side is X side, left side is described as -X side, back side is described as Z side, and front side is described as -Z side.

  As an example, the image forming apparatus 10 includes a transport unit 12 including a roll pair 13 that transports the paper P, and an image forming unit 14 that forms a toner image G using toner T on the paper P transported by the transport unit 12. And a fixing device 30 that heats and pressurizes the toner image G and fixes the toner image G on the paper P. A line indicated by a symbol K shown in FIG. The paper P of the present embodiment is an example of a transported member in the present invention.

  The image forming unit 14 includes an image forming unit 20 and a control unit 22 that controls the operation of each unit of the image forming unit 20 to form a toner image G on the paper P. For example, the image forming unit 20 is configured to perform each process of charging, exposure, development, and transfer, which are known electrophotographic methods.

[Main part configuration]
Next, the configuration of the main part in the present invention will be described.

First, the fixing device 30 will be described.
2, the fixing device 30 includes a belt 32, a heating roll 34 as an example of a driving member, side guides 36 and 38 (see FIG. 4) as an example of a conversion member, an inclined portion 37, 39, a belt conveyance device 40. Further, the fixing device 30 includes a halogen lamp 42 as an example of a heating source disposed inside the heating roll 34.

  The belt 32 has an endless shape, and comes into contact with the paper P at the surface (outer peripheral surface) 32S. Inside the belt 32, a main frame 44 extending in the Z-axis direction, a pad member 46 that presses the belt 32 from the inside to press the surface 32S against the heating roll 34, and attached to the main frame 44 to support the pad member 46. A pressure contact unit 50 including a support member 48 is provided.

  The heating roll 34 is rotatably supported by a frame member (not shown) with the Z direction as the rotation axis direction. The heating roll 34 is rotated by a driving force from an electric motor (not shown). Further, the heating roll 34 is in contact with the belt 32, and rotates the belt 32 (turning in the direction of arrow R2 in FIG. 2) as the heating roll 34 rotates (in the direction of arrow R1 in FIG. 2). . Note that the rotation axis direction of the belt 32 that is not moved in the rotation axis direction is the Z direction.

  As shown in FIG. 4, the side guide 36 is attached to one end portion in the longitudinal direction of the main frame 44 (the left end portion in FIG. 4), and one end portion in the rotation axis direction (width direction) of the belt 32. It is arranged outside the rotational axis direction than 32A.

  As shown in FIGS. 3A to 3C, the side guide 36 includes a plate-like base portion 52 and an arc-shaped support portion 54 protruding from one plate surface 52 </ b> A of the base portion 52. I have. The support portion 54 is configured such that the outer surface 54 </ b> A contacts the inner surface of the belt 32. Sliding oil is applied to the inner surface of the belt 32 in order to suppress scratches and wear on the inner surface of the belt 32 and to suppress a torque increase.

  In addition, the plate surface 52 </ b> A of the base portion 52 is a facing surface 53 where the portion between the peripheral edge portion and the support portion 54 faces the one end portion 32 </ b> A of the belt 32. When the one end portion 32A of the belt 32 comes into contact with the facing surface 53, the movement of the belt 32 in the rotation axis direction is prevented.

  The inclined portion 37 is formed on the outer surface 54 </ b> A of one of the two support portions 54. Further, since the inclined portion 37 is formed on the support portion 54, the inclined portion 37 is disposed on the inner side in the rotational axis direction of the belt 32 than the facing surface 53. Here, as shown in FIG. 5, when the belt 32 moves in the rotation axis direction, one end portion 32 </ b> A of the belt 32 rides on the inclined portion 37, and the rotation axis direction of the belt 32 is the rotation axis direction of the heating roll 34. (In FIG. 5, the inclination angle is indicated by the symbol θ). In other words, the moving force that moves the belt 32 in the rotation axis direction is converted into a force that tilts the rotation axis direction of the belt 32 with respect to the rotation axis direction of the heating roll 34. Specifically, the inclined portion 37 is inclined with respect to the rotation axis direction of the heating roll 34 when viewed in a cross section along the rotation axis direction of the heating roll 34 (in other words, the Z direction and the longitudinal direction of the main frame 44). ing. 4 to 6, the rotation axis of the belt 32 is indicated by reference numeral 32AL, and the rotation axis of the heating roll 34 is indicated by reference numeral 34AL.

  Further, the inclined portion 37 is disposed on the upstream side in the rotation direction of the belt 32 with respect to the contact portion between the belt 32 and the heating roll 34 (hereinafter referred to as “nip portion N” as appropriate). Further, the inclined portion 37 is viewed from the rotation axis direction of the belt 32 in a state where the rotation axis direction of the belt 32 is not inclined with respect to the rotation axis direction of the heating roll 34 (in other words, the Z direction, the longitudinal direction of the main frame 44). As viewed from the direction), it is formed in an arc shape along the outer surface 54A of the support portion 54.

  The side guide 38 is attached to the other end portion in the longitudinal direction of the main frame 44 (the right end portion in FIG. 4), and is more in the direction of the rotation axis than the other end portion 32B in the rotation axis direction (width direction) of the belt 32. It is arranged outside.

  The side guide 38 has the same configuration as the side guide 36 and has a shape obtained by inverting the side guide 36. 6 is an inclined portion of the side guide 38, 56 and 56A are the base portion of the side guide 38 and one plate surface of the base portion, and 57 is the opposite of the side guide 38. Reference numerals 58 and 58A denote a support portion of the side guide 38 and an outer surface of the support portion. In FIG. 6, the inclination angle when the other end portion 32 </ b> B of the belt 32 rides on the inclined portion 39 and the rotation axis direction of the belt 32 is inclined with respect to the rotation axis direction of the heating roll 34 is indicated by a sign −θ. ing.

Next, the operation of this embodiment will be described.
FIG. 4 shows a state before the belt 32 moves in the rotation axis direction. Here, for example, when the belt 32 moves to one side (left side in FIG. 5) in the rotation axis direction as shown in FIG. 5 due to an assembly error between the belt 32 and the pressure contact unit 50, The inner periphery of the one end portion 32A of the belt 32 is in contact with the inclined portion 37, and the one end portion 32A is inclined to the inclined portion 37 as the belt 32 rotates while the rotating shaft direction of the belt 32 is inclined with respect to the rotating shaft direction of the heating roll 34. Get on. That is, the moving force in the rotation axis direction of the belt 32 is converted into a force for inclining the rotation axis direction of the belt 32 with respect to the rotation axis direction of the heating roll 34 by the inclined portion 37, so . At this time, the one end portion 32A of the belt 32 riding on the inclined portion 37 pivots around the other end portion 32B, so the other side in the rotation axis direction in the vicinity of the nip portion N of the belt 32 (the right side in FIG. 5). ) (Force in the direction of arrow F shown in FIG. 5) is applied. Therefore, the belt 32 can balance the force that moves the belt 32 to one side in the rotation axis direction (force in the direction of the arrow -F shown in FIG. 5) and the force that moves the belt 32 to the other side in the rotation axis direction. Move to position.

  Further, as shown in FIG. 6, when the belt 32 moves to the other side (right side in FIG. 6) in the rotation axis direction, the inner periphery of the other end 32B of the belt 32 is inclined by the side guide 38. The other end portion 32 </ b> B rides on the inclined portion 39 as the belt 32 rotates while the rotating shaft direction of the belt 32 is inclined with respect to the rotating shaft direction of the heating roll 34. Then, the other end portion 32B of the belt 32 riding on the inclined portion 39 turns around the one end portion 32A so that the belt 32 moves the belt 32 to the other side in the rotation axis direction (in FIG. 6). (The force in the direction indicated by arrow F) and the force for moving the belt 32 to one side in the direction of the rotation axis (the force in the direction indicated by arrow -F shown in FIG. 6) are moved to a position where a balance can be obtained.

  Therefore, in the belt conveyance device 40, the belt 32 is inclined by the inclined portion 37 as compared with the configuration in which the one end portion 32A of the belt 32 is brought into contact with the facing surface 53 of the side guide 36 to prevent the belt 32 from moving on one side in the rotation axis direction. Since the one end portion 32A of the belt 32 is prevented from coming into contact with the facing surface 53, the wear of the one end portion 32A of the belt 32 is suppressed. Further, as compared with the configuration in which the one end portion 32A is in contact with the facing surface 53, an increase in torque due to movement of the belt 32 on one side in the rotation axis direction is suppressed. Similarly, in the belt conveyance device 40, compared to the configuration in which the other end portion 32 </ b> B of the belt 32 is brought into contact with the facing surface 57 of the side guide 38 and the movement of the belt 32 on the other side in the rotation axis direction is prevented, the inclined portion 39 is used. Since it is suppressed that the other end part 32B of the belt 32 contacts the opposing surface 57, wear of the other end part 32B of the belt 32 is suppressed. Further, as compared with the configuration in which the other end portion 32B is brought into contact with the facing surface 57, an increase in torque due to movement of the belt 32 on the other side in the rotation axis direction is suppressed. As a result, the life of the belt 32 is extended compared to the configuration in which the one end portion 32A and the other end portion 32B of the belt 32 are in contact with the facing surfaces 53 and 57, respectively, and the torque of the heating roll 34 that circulates the belt 32 is increased. It is suppressed and an increase in power consumption of the belt conveyance device 40 is suppressed.

  Further, in the belt conveyance device 40, the side guide 36 is provided with the inclined portion 37 that is inclined with respect to the rotation axis direction of the heating roll 34 when viewed in a cross section along the rotation axis direction of the heating roll 34. Compared to the configuration having a step with respect to the rotation axis direction of the belt 32, the one end portion 32A can smoothly get on and off the inclined portion 37, so that the rotation axis direction of the belt 32 is smoothly inclined. The same action as described above can be obtained for the inclined portion 39 of the side guide 38.

  Further, in the belt conveyance device 40, the inclined portion 37 of the side guide 36 is disposed upstream of the nip portion N in the rotational direction of the belt 32 and is in contact with the inner periphery of the one end portion 32A of the belt 32. Compared to the configuration in which the belt 32 is arranged downstream of the portion N in the rotation direction of the belt 32 and is in contact with the inner periphery of the one end portion 32A of the belt 32, the one end portion 32A riding on the inclined portion 37 immediately before the nip portion N is the other end Compared with the part 32B, it can turn around. For this reason, the force (refer FIG. 5) which acts on the other side of the rotating shaft direction which acts in the nip part N vicinity of the belt 32 becomes large, and the torque raise accompanying the movement of the rotating shaft direction one side of the belt 32 is suppressed. The same action as described above can be obtained for the inclined portion 39 of the side guide 38.

  In the fixing device 30, the life of the belt 32 is extended as compared with the configuration in which the belt conveying device 40 is not provided.

  In the image forming apparatus 10, power consumption can be suppressed compared to a configuration that does not include the fixing device 30.

  In the above-described embodiment, the inclined portion 37 is formed on the outer surface 54A of the support portion 54 of the side guide 36, but the present invention is not limited to this configuration. For example, a configuration may be adopted in which the side guide 62 is attached to one end portion in the longitudinal direction of the main frame 44 as in the belt conveyance device 60 of the modification shown in FIGS. 7 and 8. In the side guide 62, a support portion 68 projects from the peripheral edge portion of the plate-like base portion 66, and an inclined portion 70 is formed at the tip portion of the support portion 68. The inclined portion 70 is in contact with the outer periphery of the one end portion 32 </ b> A of the belt 32 and is disposed downstream of the nip portion N in the rotational direction of the belt 32. Note that another side guide having the same configuration as the side guide 62 and having an inverted shape may be attached to the other end of the main frame 44 in the longitudinal direction, or the side guide 38 of the above-described embodiment may be attached. It may be attached. According to the said structure, the effect | action similar to the belt conveying apparatus 40 of above-mentioned embodiment is acquired.

  In the above-described embodiment, the inclined portion 37 is formed in the side guide 36, but the present invention is not limited to this configuration. For example, it is good also as a structure which provides the inclination part 82 in the one end part of the longitudinal direction of the main frame 44 like the belt conveyance apparatus 80 of the other modification shown by FIG.9 and FIG.10. The inclined portion 82 is in contact with the inner periphery of the one end portion 32 </ b> A of the belt 32 and is disposed on the upstream side of the nip portion N in the rotational direction of the belt 32. The other end of the main frame 44 in the longitudinal direction may be provided with another inclined portion having the same configuration as the inclined portion 82 and the shape reversed, or the side guide 38 of the above-described embodiment. It may be attached. According to the said structure, the effect | action similar to the belt conveying apparatus 40 of above-mentioned embodiment is acquired. In the case of the above configuration, the main frame 44 is an example of the conversion member of the present invention.

  In the above-described embodiment, the inclined portions are arranged on both end sides in the rotation axis direction of the belt 32, but the present invention is not limited to this configuration. When the direction of movement of the belt 32 in the rotation axis direction is known in advance, the inclined portion may be arranged only on the side where the belt 32 moves.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made without departing from the spirit of the present invention. For example, you may combine the principal part structure of Embodiment 1-3 shown above suitably.

<Experimental example>
Next, in order to confirm the effect of the present invention, the following experiment was performed using the belt conveyance device of the example and the belt conveyance device of the comparative example.

(Experiment contents)
The amount of movement of each belt in the direction of the rotation axis when the belts of the belt conveyance devices of Comparative Examples 1 to 3 and Examples 1 to 3 described below were continuously rotated for a certain time was measured. The experimental results of Comparative Examples 1 to 3 are shown graphically in FIG. 11, and the experimental results of Examples 1 to 3 are shown graphically in FIG. In FIGS. 11 and 12, the horizontal axis indicates time, the vertical axis indicates the amount of movement of the belt in the rotation axis direction, and the vertical axis and the horizontal axis are the same scale.

(Belt conveyor used in the experiment)
Example 1: A belt conveyance device having the same structure as that of the first embodiment has an alignment error of 1 mm.
Example 2: An alignment error is 2 mm in the belt conveyance device having the same structure as that of the first embodiment.
Example 3: The belt conveyance device having the same structure as that of the first embodiment has an alignment error of 3 mm.
Comparative Example 1: The alignment error is 1 mm in the belt conveyance device in which the inclined portion is not formed on the side guide in the first embodiment.
Comparative Example 2: Alignment error is 2 mm with a belt conveyance device having the same structure as Comparative Example 1.
Comparative Example 3: The belt conveyance device having the same structure as Comparative Example 1 has an alignment error of 3 mm.

  From the results of FIGS. 11 and 12, it can be seen that the belt conveyance device of the example can suppress the movement amount of the belt in the rotation axis direction even with the same alignment error as compared with the belt conveyance device of the comparative example.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 30 Fixing apparatus 32 Belt 32A One end part (end part of belt rotating shaft direction)
32B The other end (the end of the belt in the rotation axis direction)
34 Heating roll (drive member)
36 Side guide (conversion member)
37 Inclined part 38 Side guide (conversion member)
39 Inclined part 40 Belt conveyor 42 Halogen lamp (heating source)
60 Belt conveying device 62 Side guide 66 Base portion 68 Supporting portion 70 Inclining portion 80 Belt conveying device 82 Inclining portion P Paper (conveyed member)

Claims (6)

An endless belt in contact with the conveyed member on the surface;
A driving member that contacts the outer periphery of the belt and drives the belt to circulate;
A conversion member that contacts an inner periphery or an outer periphery at an end of the belt in the rotation axis direction and converts the movement of the belt in the rotation axis direction into an inclination of the drive member with respect to the rotation axis direction;
A belt conveyance device having   The conversion member is inclined with respect to the rotation axis direction of the drive member as seen in a cross section along the rotation axis direction of the drive member, and has an inclined portion on which the end of the belt moving in the rotation axis direction rides. The belt conveyance device according to claim 1, comprising:   The said inclined part is arrange | positioned rather than the contact part of the said belt and the said drive member in the rotation direction upstream of the said belt, and contacts the inner periphery in the edge part of the rotating shaft direction of the said belt. Belt conveyor.   The belt according to claim 2, wherein the inclined portion is disposed downstream of the contact portion between the belt and the driving member in the rotation direction of the belt and contacts an outer periphery at an end portion in the rotation axis direction of the belt. Conveying device. The belt conveyance device according to any one of claims 1 to 4,
A heating source disposed inside the drive member or the belt;
A fixing device. An image forming unit that forms an image on a transported member;
The fixing device according to claim 5, wherein an image formed on the transported member by the image forming unit is fixed to the transported member.
An image forming apparatus.