JP2017065838A - Sheet feeding roller and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeding roller and image formation apparatus which can suppress conveyance failure of sheets.SOLUTION: A sheet feeding roller includes: a bearing part 110 which is rotationally driven to a rotation drive shaft; and a rubber part 120 which is held on the outer peripheral surface of the bearing part 110 and is brought into contact with a sheet P. The bearing part 110 includes: a holding bearing section 111 which holds the rubber part 120; and a bearing part side first locking section 112 which locks the rubber part 120 in the rotation direction C of the bearing part 110 and rubber part 120. The rubber part 120 includes: a cylindrical contact rubber section 121 which is brought into contact with the sheet P; and a rubber part side first locking section 122 which is locked to the bearing part side first locking section 112 in the rotation direction C. The rubber part side first locking section 122 is provided in a non-contact area E being an area in which the rubber part 120 is not brought into contact with the sheet P in the rotation axial line B direction of the bearing part 110 and rubber part 120.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a paper feed roller for conveying paper and an image forming apparatus.

  In the image forming apparatus, a paper feed roller is used when transporting sheets stacked in a cassette. The paper feed roller is composed of a bearing portion (also referred to as a collar or the like) held on the rotation drive shaft and a rubber portion held on the outer peripheral surface of the bearing portion. Then, the rotational driving force of the rotational drive shaft is transmitted from the bearing portion to the rubber portion, and the rubber portion in contact with the paper rotates, whereby the paper is conveyed. For this reason, in the paper feed roller, it is important that the rubber portion does not idle with respect to the bearing portion.

  Therefore, in Patent Document 1, a protruding portion extending in the axial direction is formed on the outer peripheral surface of the bearing portion, and a concave portion into which the protruding portion is inserted is formed on the inner peripheral surface of the rubber portion. Prevents idling of parts.

Japanese Patent Laid-Open No. 2001-039549

  However, in the technique described in Patent Document 1, the thickness of the rubber part becomes nonuniform in the circumferential direction due to the protruding part and the concave part extending in the axial direction. As a result, the rebound resilience of the rubber part becomes non-uniform in the circumferential direction of the rubber part, so that a paper conveyance failure is likely to occur.

  SUMMARY An advantage of some aspects of the invention is that it provides a paper feed roller and an image forming apparatus that can suppress paper conveyance failure.

  A paper feed roller according to the present invention is a paper feed roller including a bearing portion that is rotationally driven by a rotational drive shaft, and a rubber portion that is held on an outer peripheral surface of the bearing portion and abuts against a sheet. The bearing portion has a holding bearing portion that holds the rubber portion, and a bearing portion side first latching portion that latches the rubber portion in the rotation direction of the bearing portion and the rubber portion, and the rubber portion contacts the paper A cylindrical abutting rubber portion, and a rubber portion side first hooking portion hooked to the bearing portion side first hooking portion in the rotation direction. The rubber part is provided in a non-contact area which is an area where the rubber part does not contact the paper in the rotation axis direction of the bearing part and the rubber part.

  In the paper feed roller according to the present invention, the rubber part side first hooking part is hooked on the bearing part side first hooking part in the rotation direction, so that idling of the rubber part relative to the bearing part in the rotation direction is suppressed. The And since the rubber part side 1st latching part is provided in the non-contact area | region which is not contact | abutted with a paper, the thickness of the contact rubber part contact | abutted to a paper can be made uniform. Thereby, the conveyance failure of a sheet | seat can be suppressed, suppressing the idle rotation of the rubber part with respect to the bearing part in a rotation direction.

  In this case, the rubber part side first latching part has a first groove part extending in the rotation axis direction, and the bearing part side first latching part has a first projection part press-fitted into the first groove part. Also good. In this paper feed roller, the first protrusion is press-fitted into the first groove, so that the rubber part-side first hook can be easily hooked to the bearing part-side first hook in the rotation direction. .

  In addition, the width of at least a part of the first protrusion may be larger than the width of the first groove in the rotation direction. Similarly, the width of at least a part of the first protrusion may be larger than the width of the first groove in the radial direction orthogonal to the rotation axis direction. In this paper feeding roller, when the first protrusion is inserted into the first groove, the first protrusion bites into the side surface of the first groove, so that the displacement of the rubber portion with respect to the bearing portion in the rotation axis direction can be suppressed. it can.

  The bearing portion side first latching portion may be provided at one end portion of the bearing portion, and the rubber portion side first latching portion may be provided at one end portion of the rubber portion. In this paper feed roller, the bearing portion side first latching portion and the rubber portion side first latching portion are provided at one end of the bearing portion and the rubber portion. The end opposite to the portion 112 can be formed into a flat cylindrical shape. Thereby, a bearing part can be easily inserted in a rubber part.

  In this case, the bearing portion has a bearing portion-side second latching portion that is provided at an end of the bearing portion opposite to the bearing portion-side first latching portion and latches the rubber portion in the rotation direction. The rubber part is provided at the end of the rubber part opposite to the first hook part on the rubber part side and is hooked on the second hook part on the bearing part side in the rotational direction. The rubber part side second hook part may be provided in the non-contact area. In this paper feed roller, a bearing portion side second latching portion similar to the bearing portion side first latching portion is provided at the end of the bearing portion opposite to the bearing portion side first latching portion. Moreover, the rubber part side 2nd latching part similar to the rubber part side 1st latching part is provided in the edge part on the opposite side to the rubber part side 1st latching part of a rubber part. Thereby, since a rubber part is latched by a bearing part in the both ends in a rotation axis direction, it can control idling of a rubber part to a bearing part in a rotation direction, further suppressing twist of a rubber part.

  Further, the rubber part side second latching part may have a second groove part extending in the rotation axis direction, and the bearing part side second latching part may have a second projection part press-fitted into the second groove part. Good. In this paper feed roller, the second protrusion is press-fitted into the second groove, so that the rubber part side second hooking part can be easily hooked to the bearing part side second hooking part in the rotation direction. .

  Furthermore, the width of at least a part of the second protrusion may be larger than the width of the second groove in the rotation direction. Similarly, the width of at least a part of the second protrusion may be larger than the width of the second groove in the radial direction orthogonal to the rotation axis direction. In this paper feeding roller, when the second protrusion is inserted into the second groove, the second protrusion bites into the side surface of the second groove, so that the displacement in the rotation axis direction of the rubber portion with respect to the bearing portion can be suppressed. it can.

  Further, the bearing portion side second latching portion may be detachably attached to the holding bearing portion. In this paper feed roller, since the bearing portion side second latching portion is detachably attached to the holding bearing portion, the bearing portion side second latching portion must be removed when inserting the bearing portion into the rubber portion. Thus, the bearing portion can be easily inserted into the rubber portion. On the other hand, after the bearing portion is inserted into the rubber portion, both end portions in the rotation axis direction of the rubber portion can be hooked in the rotation direction by attaching the bearing portion side second hooking portion.

  In this case, the bearing portion has an elastic latching portion that extends in the opposite direction from the first latching portion on the bearing portion side and elastically deforms in the radial direction of the rubber portion, and the second latching portion on the bearing portion side is held. It may be latched by the elastic latching part from the opposite side to the bearing part side 1st latching part with respect to a bearing part. In this paper feed roller, the elastic hooking portion that locks the bearing portion side second hooking portion is elastically deformed in the radial direction of the rubber portion. For this reason, when inserting a bearing part into a rubber part, a bearing part can be easily inserted in a rubber part by elastically deforming an elastic latching part to the inside of a rubber part in the radial direction. On the other hand, after the bearing portion is inserted into the rubber portion, the elastic latching portion is restored to the radially outer side of the rubber portion, and the bearing portion side from the opposite side of the bearing portion side first latching portion with respect to the holding bearing portion is restored. Lock the second hook. Thereby, it can suppress that the bearing part side 2nd latching | locking part falls off.

  An image forming apparatus according to the present invention includes any one of the paper feed rollers described above. In the image forming apparatus according to the present invention, since the above-described paper feed roller is provided, it is possible to suppress paper conveyance failure while suppressing idling of the rubber portion with respect to the bearing portion in the rotation direction.

  According to the present invention, it is possible to suppress paper conveyance failure.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an exemplary embodiment. It is the perspective view which looked at the paper feed roller of a first embodiment from the right side. FIG. 3 is a left side view of the paper feed roller as seen from the direction of the arrow II in FIG. 2. It is sectional drawing in the IV-IV line shown in FIG. FIG. 3 is an exploded perspective view of the paper feed roller shown in FIG. 2. It is a figure for demonstrating the relationship between a 1st projection part and a 1st groove part. It is the perspective view which looked at the paper feed roller of a second embodiment from the left. FIG. 8 is a left side view of the paper feed roller as seen from the direction of the arrow VIII in FIG. 7. It is sectional drawing in the IX-IX line shown in FIG. FIG. 8 is an exploded perspective view of the paper feed roller shown in FIG. 7. It is sectional drawing of the paper feed roller of 2nd embodiment. It is a top view which shows a part of paper feed roller of 2nd embodiment. It is sectional drawing in the XIII-XIII line | wire shown in FIG. It is sectional drawing which shows the modification of the bearing part side 2nd latching | locking part in 2nd embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

[First embodiment]
(Overall configuration of image forming apparatus)
First, a schematic configuration of the image forming apparatus according to the present embodiment will be described. The image forming apparatus 1 is an apparatus that forms a color image using magenta, yellow, cyan, and black colors. As shown in FIG. 1, the image forming apparatus 1 includes a recording medium transport unit 10 that transports a sheet P, a developing device 20 that develops an electrostatic latent image, and a transfer unit 30 that performs secondary transfer of a toner image onto the sheet P. A photosensitive drum 40 that is an electrostatic latent image carrier on which an image is formed on the peripheral surface, and a fixing unit 50 that fixes the toner image onto the paper P.

  The recording medium transport unit 10 transports the paper P as a recording medium on which an image is formed on the transport path R1. The paper P is stacked and accommodated in the cassette K, picked up by the paper feed roller 100 and conveyed. The recording medium transport unit 10 causes the paper P to reach the secondary transfer region R2 via the transport path R1 at the timing when the toner image transferred onto the paper P reaches the secondary transfer region R2.

  Four developing devices 20 are provided for each color. Each developing device 20 includes a developing roller 21 that carries toner on the photosensitive drum 40. In the developing device 20, the toner and the carrier are adjusted so as to have a desired mixing ratio, and further mixed and stirred to uniformly distribute the toner and adjust the developer to which the optimum charge amount is given. The developer is carried on the developing roller 21. When the developer is transported to a region facing the photosensitive drum 40 by the rotation of the developing roller 21, toner in the developer carried on the developing roller 21 is formed on the peripheral surface of the photosensitive drum 40. The electrostatic latent image is developed and the electrostatic latent image is developed.

  The transfer unit 30 conveys the toner image formed by the developing device 20 to the secondary transfer region R2 where the toner image is secondarily transferred to the paper P. The transfer unit 30 includes a transfer belt 31, suspension rollers 31a, 31b, 31c, and 31d that suspend the transfer belt 31, a primary transfer roller 32 that sandwiches the transfer belt 31 together with the photosensitive drum 40, and a transfer belt together with the suspension roller 31d. And a secondary transfer roller 33 that sandwiches 31.

  The transfer belt 31 is an endless belt that circulates and moves by suspension rollers 31a, 31b, 31c, and 31d. The primary transfer roller 32 is provided so as to press the photosensitive drum 40 from the inner peripheral side of the transfer belt 31. The secondary transfer roller 33 is provided so as to press the suspension roller 31 d from the outer peripheral side of the transfer belt 31.

  Four photosensitive drums 40 are provided for each color. Each photoconductor drum 40 is provided along the moving direction of the transfer belt 31. On the circumference of the photosensitive drum 40, a developing device 20, a charging roller 41, an exposure unit 42, and a cleaning unit 43 are provided.

  The charging roller 41 is a charging unit that uniformly charges the surface of the photosensitive drum 40 to a predetermined potential. The charging roller 41 moves following the rotation of the photosensitive drum 40. The exposure unit 42 exposes the surface of the photosensitive drum 40 charged by the charging roller 41 according to an image formed on the paper P. As a result, the potential of the portion exposed by the exposure unit 42 on the surface of the photosensitive drum 40 changes, and an electrostatic latent image is formed. The four developing devices 20 develop the electrostatic latent image formed on the photosensitive drum 40 with toner supplied from a toner tank N provided opposite to each developing device 20, and generate toner images. . Each toner tank N is filled with magenta, yellow, cyan and black toners. The cleaning unit 43 collects the toner remaining on the photosensitive drum 40 after the toner image formed on the photosensitive drum 40 is primarily transferred to the transfer belt 31.

  The fixing unit 50 attaches and fixes the toner image secondarily transferred from the transfer belt 31 to the paper P on the paper P. The fixing unit 50 includes a heating roller 52 that heats the paper P, and a pressure roller 54 that presses the heating roller 52. The heating roller 52 and the pressure roller 54 are formed in a cylindrical shape, and the heating roller 52 includes a heat source such as a halogen lamp inside. A fixing nip portion which is a contact area is provided between the heating roller 52 and the pressure roller 54, and the toner image is melted and fixed on the paper P by passing the paper P through the fixing nip portion.

  Further, the image forming apparatus 1 is provided with discharge rollers 62 and 64 for discharging the paper P on which the toner image is fixed by the fixing unit 50 to the outside of the apparatus.

  Subsequently, a printing process by the image forming apparatus 1 will be described. When an image signal of an image to be recorded is input to the image forming apparatus 1, the control unit of the image forming apparatus 1 rotates the paper feed roller 100 to pick up and convey the paper P stacked on the cassette K. Based on the received image signal, the charging roller 41 uniformly charges the surface of the photosensitive drum 40 to a predetermined potential (charging process). Thereafter, the exposure unit 42 irradiates the surface of the photosensitive drum 40 with laser light to form an electrostatic latent image (exposure process).

  In the developing device 20, the electrostatic latent image is developed to form a toner image (developing process). The toner image thus formed is primarily transferred from the photosensitive drum 40 to the transfer belt 31 in a region where the photosensitive drum 40 and the transfer belt 31 face each other (transfer process). On the transfer belt 31, toner images formed on the four photosensitive drums 40 are sequentially stacked to form one stacked toner image. The laminated toner image is secondarily transferred onto the paper P conveyed from the recording medium conveyance unit 10 in the secondary transfer region R2 where the suspension roller 31d and the secondary transfer roller 33 face each other.

  The sheet P on which the laminated toner image is secondarily transferred is conveyed to the fixing unit 50. By passing the paper P between the heating roller 52 and the pressure roller 54 while applying heat and pressure, the laminated toner image is melted and fixed on the paper P (fixing step). Thereafter, the paper P is discharged to the outside of the image forming apparatus 1 by the discharge rollers 62 and 64.

(Conveyor unit configuration)
Next, the paper feed roller 100 will be described in more detail. As shown in FIGS. 2 to 5, the paper feed roller 100 is formed in a substantially cylindrical shape, and is a member that conveys the paper P by being rotationally driven by a rotational drive shaft (not shown). The paper feed roller 100 includes a bearing portion 110 that is rotationally driven by a rotational drive shaft, and a rubber portion 120 that is held on the outer peripheral surface of the bearing portion 110 and abuts against the paper P.

  The bearing portion 110 is formed in a substantially cylindrical shape, and a through hole through which the rotation drive shaft is inserted is formed in the center portion in the radial direction A (not shown) of the paper feed roller 100. The radial direction A is the same as the radial direction of the bearing portion 110 and the rubber portion 120. The bearing portion 110 includes a holding bearing portion 111, a bearing portion side first latching portion 112, and a connection portion 113.

  The holding bearing portion 111 is a portion that holds the rubber portion 120. The holding bearing portion 111 is formed in a cylindrical shape centered on the rotation axis B of the paper feed roller 100. Specifically, the holding bearing portion 111 is formed in a cylindrical shape having the same cross section over the entire region of the rotation axis B direction. The rotation axis B is the same as the rotation axis of the bearing part 110 and the rubber part 120.

  The bearing portion side first latching portion 112 is a portion that latches the rubber portion 120 in the rotation direction C of the paper feed roller 100. The rotation direction C is the same as the rotation direction of the bearing portion 110 and the rubber portion 120. The bearing portion side first latching portion 112 is provided at one end of the bearing portion 110. The bearing portion side first latching portion 112 includes a flange portion 114 and a first protrusion 115.

  The flange portion 114 extends outward in the radial direction A from the outer peripheral surface of the holding bearing portion 111. The inner diameter of the flange portion 114 is the same as the inner diameter of the holding bearing portion 111. The outer diameter of the flange portion 114 is larger than the outer diameter of the holding bearing portion 111.

  The first protrusion 115 is a part that hooks the rubber part 120 in the rotation direction C. The first projecting portion 115 is provided on the surface of the flange portion 114 on the holding bearing portion 111 side. One or more first protrusions 115 are provided on the flange 114. When a plurality of the first protrusions 115 are provided, they are provided at equal angular intervals on the same circle in the rotation direction C. In the present embodiment, it is assumed that four first protrusions 115 are provided on the same circle in the rotation direction C at 90 ° intervals in the flange portion 114.

  The first protruding portion 115 extends from the flange portion 114 toward the holding bearing portion 111 (the opposite side of the holding bearing portion 111 from the bearing portion side first latching portion 112). The first projecting portion 115 may be connected to the holding bearing portion 111 or may be separated from the holding bearing portion 111. The first projecting portion 115 has a body portion 115a and a widened portion 115b.

  The trunk portion 115 a is a portion connected to the flange portion 114. In the rotation direction C, the width of the trunk portion 115a is the same over the entire region in the rotation axis B direction. Although the outer diameter of the trunk | drum 115a is not specifically limited, It is preferable that it is the same as the outer diameter of the flange part 114. FIG.

  The widened portion 115b is a portion connected to the distal end side of the trunk portion 115a (the side opposite to the flange portion 114 of the trunk portion 115a). In the rotation direction C, the widened portion 115b is widened from the distal end side of the first projecting portion 115 toward the trunk portion 115a. In the rotation direction C, the maximum width of the widened portion 115b is larger than the width of the trunk portion 115a.

  The connection part 113 is a part meshed with the rotation drive shaft. The connection portion 113 is provided on the surface of the flange portion 114 opposite to the holding bearing portion 111. The connection portion 113 is formed in a rod shape and extends from the flange portion 114 toward the opposite side of the bearing portion side first latching portion 112. A plurality of connection portions 113 are provided in the flange portion 114, and are provided at positions that are equiangular with each other on the same circle of the flange portion 114. In the drawing, a case where six connecting portions 113 are provided in the flange portion 114 is shown. Then, in the rotation direction C, the rotation drive shaft is engaged (or latched) with the connection portion 113, whereby the rotation drive force of the rotation drive shaft is transmitted from the connection portion 113 to the bearing portion 110.

  The rubber part 120 has a contact rubber part 121 and a rubber part side first hook part 122.

  The abutting rubber portion 121 is a cylindrical portion that abuts on the paper P. The contact rubber portion 121 is formed of a soft resin so that the paper P stacked on the cassette K can be picked up. As a resin material of the contact rubber part 121, for example, urethane, EPDN, or silicon can be used.

  The contact rubber part 121 is formed in a cylindrical shape with the rotation axis B as the center. Specifically, the contact rubber portion 121 is formed in a cylindrical shape having the same cross section over the entire region in the rotation axis B direction. That is, the thickness (wall thickness) of the contact rubber portion 121 is uniform throughout the rotation axis B direction and the rotation direction C.

  In the direction of the rotation axis B, the length of the contact rubber portion 121 is shorter than the length of the holding bearing portion 111 so that the tip end portion of the bearing portion 110 protrudes from the contact rubber portion 121.

  The outer diameter of the contact rubber portion 121 is larger than the outer diameter of the flange portion 114 so that the flange portion 114 does not contact the paper P. When the state of the contact rubber part 121 removed from the bearing part 110 is a natural state, the inner diameter of the contact rubber part 121 in the natural state is the same as the outer diameter of the holding bearing part 111 or outside the holding bearing part 111. Smaller than the diameter. When the inner diameter of the contact rubber part 121 is smaller than the outer diameter of the holding bearing part 111, the dimensional difference between the inner diameter of the contact rubber part 121 and the outer diameter of the holding bearing part 111 is determined by the operator. The value is preferably such that the holding bearing portion 111 can be easily inserted. For example, when the outer diameter of the holding bearing portion 111 is 10 mm and the outer diameter of the contact rubber portion 121 is 20 mm, the inner diameter of the contact rubber portion 121 in the natural state is 8.8 mm, and the contact in the natural state The thickness of the rubber part 121 in the radial direction A can be 5.6 mm. The length of the contact rubber portion 121 in the direction of the rotation axis B can be set to 30 mm, for example.

  The rubber part side first hook part 122 is a part that is hooked to the bearing part side first hook part 112 in the rotation direction C. The rubber part side first latching part 122 is provided in a non-contact area that is an area where the rubber part does not contact the paper in the direction of the rotation axis B.

  Specifically, the rubber part side first hooking part 122 is provided at one end of the rubber part 120. Here, the end portion on one side of the rubber portion 120 where the rubber portion side first latching portion 122 is provided is the bearing portion side first latching portion 112 with respect to the holding bearing portion 111 in the rotation axis B direction. It is the edge part of the side provided.

  The rubber part side first latching part 122 extends from one end surface of the contact rubber part 121 toward the side opposite to the contact rubber part 121. The rubber part side first latching part 122 is formed in a cylindrical shape with the rotation axis B as the center. The outer diameter of the rubber part side first hooking part 122 is smaller than the outer diameter of the contact rubber part 121 so that the rubber part side first hooking part 122 does not contact the paper P. For this reason, in the rubber part 120, the area where the rubber part 120 abuts on the paper P in the direction of the rotation axis B is only the abutting rubber part 121, and the area where the rubber part side first latching part 122 is provided is. The rubber portion 120 is an area where the sheet P is not in contact with the rotation axis B direction. That is, the rubber part 120 is provided in the contact area D, which is the area where the rubber part 120 contacts the paper P in the rotation axis B direction, and the rubber part side first hooking part 122 is arranged in the rotation axis B direction. The rubber part 120 is provided in a non-contact area E that is an area where the rubber part 120 does not contact the paper P.

  Moreover, it is preferable that the outer diameter of the rubber part side first latching part 122 is larger than the outer diameter of the flange part 114. The inner diameter of the rubber part side first hook 122 is the same as the inner diameter of the contact rubber part 121 or larger than the inner diameter of the contact rubber part 121. In this case, from the viewpoint of ease of manufacture, it is preferable that the inner diameter of the rubber part side first latching part 122 is the same as the inner diameter of the contact rubber part 121.

  The rubber part side first latching part 122 has one or a plurality of first groove parts 123 extending in the rotation axis B direction. The first groove portion 123 is a groove into which the first protrusion 115 is press-fitted. For this reason, the number of the first groove portions 123 is the same as the number of the first protrusion portions 115. When a plurality of first groove portions 123 are provided, they are provided at equal angular intervals in the rotation direction C on the same circle having the same radius as the first groove portion 123. In the present embodiment, since four first groove portions 123 are provided, four first groove portions 123 are provided in the same circular shape in the rotation direction C at 90 ° intervals on the rubber portion side first hook portion 122. Yes.

  The first groove portion 123 extends from the end surface of the rubber portion side first hooking portion 122 on the side opposite to the contact rubber portion 121 toward the contact rubber portion 121 side in the rotation axis B direction. The first groove portion 123 may extend to the end of the rubber portion side first hook portion 122 on the contact rubber portion 121 side in the direction of the rotation axis B, and the rubber portion side first hook portion 122 may contact rubber. It does not need to extend to the end on the part 121 side. In the present embodiment, the first groove portion 123 will be described as extending to the end of the rubber portion side first latching portion 122 on the contact rubber portion 121 side in the rotation axis B direction.

  The first groove portion 123 extends in the radial direction A. In the radial direction A, the first groove 123 may penetrate the rubber part side first hook part 122 or may not penetrate the rubber part side first hook part 122. In the present embodiment, the first groove portion 123 will be described as passing through the rubber portion side first latching portion 122 in the radial direction A.

  In the rotation direction C, the width of the first groove portion 123 is smaller than the maximum width of the widened portion 115b. For this reason, as shown in FIG. 6, when the first protrusion 115 is inserted into the first groove 123, the widened portion 115 b bites into the side surface of the first groove 123.

  Next, how to assemble the paper feed roller 100 will be described.

  First, the end of the rubber part 120 opposite to the bearing part side first latching part 112 is inserted from the rubber part side first latching part 122 side. Then, the holding bearing portion 111 is passed through the rubber portion 120 and the first protrusion 115 is press-fitted into the first groove portion 123.

  Then, the rubber part side first hook part 122 is hooked on the bearing part side first hook part 112 in the rotation direction C, and the movement of the rubber part 120 in the rotation direction C with respect to the bearing part 110 is restricted. Further, the widened portion 115b bites into the side surface of the first groove portion 123, and the movement of the rubber portion 120 with respect to the bearing portion 110 in the direction of the rotation axis B is restricted. Thereby, the paper feed roller 100 in which the rubber part 120 is held on the outer peripheral surface of the bearing part 110 is obtained.

  As described above, in the paper feed roller 100 according to the present embodiment, the rubber part side first hooking part 122 is hooked on the bearing part side first hooking part 112 in the rotation direction C, whereby the bearing in the rotation direction C is obtained. The idling of the rubber part 120 with respect to the part 110 is suppressed. And since the rubber part side 1st latching part 122 is provided in the non-contact area | region E which is not contact | abutted with the paper P, the thickness of the contact rubber part 121 contact | abutted to the paper P can be made uniform. it can. Thereby, the conveyance failure of the paper P can be suppressed while suppressing idling of the rubber part 120 with respect to the bearing part 110 in the rotation direction C.

  Further, in this paper feed roller 100, the first protrusion 115 is press-fitted into the first groove 123, so that the rubber part-side first hook 122 can be easily moved in the rotation direction C. 112 can be hooked.

  Further, in this paper feed roller 100, when the first protrusion 115 is inserted into the first groove 123, the widened portion 115 b of the first protrusion 115 bites into the side surface of the first groove 123. Deviation in the direction of the rotation axis B of the portion 120 can be suppressed.

  Further, in this paper feed roller 100, the bearing portion side first latching portion 112 and the rubber portion side first latching portion 122 are provided at one end of the bearing portion 110 and the rubber portion 120. The end on the opposite side of the bearing portion side first latching portion 112 can be formed into a flat cylindrical shape. Thereby, the bearing part 110 can be easily inserted into the rubber part 120.

[Second Embodiment]
Next, a second embodiment will be described. The second embodiment is basically the same as the first embodiment, but only a part of the paper feed roller is different from the first embodiment. For this reason, below, only the matter which is different from 1st embodiment is demonstrated, and description of the matter similar to 1st embodiment is abbreviate | omitted.

  As shown in FIGS. 7 to 10, the paper feed roller 200 according to the second embodiment includes a bearing unit 210 that is rotationally driven by a rotational drive shaft (not shown), and is held on the outer peripheral surface of the bearing unit 210 to form a sheet. And a rubber part 220 to be abutted.

  The rubber part 220 is basically the same as the rubber part 120 of the first embodiment, and only a part thereof is different from the rubber part 120. The rubber part 220 includes a cylindrical contact rubber part 121 that is in contact with the paper P, a rubber part side first hook part 122 that is hooked on the bearing part 210 in the rotation direction C, and a bearing in the rotation direction C. And a rubber part side second hooking part 222 hooked on the part 210.

  The rubber part side second hooking part 222 is provided at the end of the rubber part 220 opposite to the rubber part side first hooking part 122. The rubber part side first hook part 222 is provided on the opposite side to the rubber part side first hook part 122 with respect to the rubber part side first hook part 122. The same as 122. That is, the rubber part side second hooking part 222 is in the non-contact area E, which is an area where the rubber part is not in contact with the paper in the rotation axis B direction, like the rubber part side first hooking part 122. The second groove portion 223 corresponding to the first groove portion 123 is provided.

  The bearing part 210 is basically the same as the bearing part 110 of the first embodiment. The bearing portion 210 includes a holding bearing portion 111 that holds the rubber portion 220, a bearing portion-side first hook portion 112 that hooks the rubber portion 220 in the rotation direction C, and a connection portion 113 that is meshed with the rotation drive shaft. The bearing portion side second latching portion 212 that latches the rubber portion 220 in the rotation direction C, and the attachment portion 213 that detachably attaches the bearing portion side second latching portion 212 to the holding bearing portion 111.

  The attachment portion 213 is provided at an end portion of the holding bearing portion 111 opposite to the bearing portion side first latching portion 112. The attachment part 213 includes a position restricting part 214 and an elastic hooking part 215.

  The position restricting portion 214 extends from the end surface of the holding bearing portion 111 opposite to the bearing portion side first latching portion 112 toward the side opposite to the bearing portion side first latching portion 112. The position restricting portion 214 is formed in a substantially cylindrical shape divided into a plurality in the rotation direction C. And each piece of the position control part 214 divided | segmented into plurality is mutually spaced apart, and the clearance gap is formed between each piece. In the present embodiment, the position restricting unit 214 is divided into four. The inner diameter of the position restricting portion 214 is the same as the inner diameter of the holding bearing portion 111. The outer diameter of the position restricting portion 214 is the same as the outer diameter of the holding bearing portion 111.

  The elastic latching part 215 is arrange | positioned in the clearance gap between each piece of the position control part 214 divided | segmented into plurality. The elastic hooking portion 215 includes a leaf spring portion 215a and a hook portion 215b.

  The leaf spring part 215a is a part that cantilever-supports the hook part 215b. The leaf spring portion 215a extends from the end surface of the holding bearing portion 111 opposite to the bearing portion side first hook portion 112 toward the opposite side of the bearing portion side first hook portion 112. The leaf spring portion 215a is formed in a thin plate shape in the radial direction A so as to be elastically deformed in the radial direction A. The inner diameter of the leaf spring portion 215a is larger than the inner diameter of the holding bearing portion 111 so that the leaf spring portion 215a can be bent inward in the radial direction A in a state where the rotation drive shaft is inserted into the bearing portion 110. The outer diameter of the leaf spring portion 215a is the same as the outer diameter of the holding bearing portion 111.

  The hook part 215b is a part for latching the bearing part side second latching part 212. The hook portion 215b is provided at the distal end portion of the leaf spring portion 215a and protrudes outward in the radial direction A from the leaf spring portion 215a. The hook portion 215 b gradually rises outward in the radial direction A toward the holding bearing portion 111. The end surface of the hook portion 215b on the holding bearing portion 111 side is a flat surface that is substantially perpendicular to the radial direction A. Thereby, the hook part 215b can latch the bearing part side 2nd latching part 212 from the direction on the opposite side to the bearing part side 1st latching part 112 with respect to the holding bearing part 111. FIG.

  The bearing portion side second hooking portion 212 is provided at the end of the bearing portion 210 opposite to the bearing portion side first hooking portion 112. The bearing portion side second latching portion 212 is a separate member from the holding bearing portion 111, the bearing portion side first latching portion 112, and the connection portion 113. The bearing portion side second latching portion 212 is formed in a substantially cylindrical shape, and a through hole through which the attachment portion 213 is inserted is formed in the center portion in the radial direction A. And the bearing part side 2nd latching | locking part 212 is attached to the attachment part 213 so that attachment or detachment is possible by the attachment part 213 being inserted. That is, the bearing portion side second latching portion 212 is detachably attached to the holding bearing portion 111, the bearing portion side first latching portion 112 and the connection portion 113 by the attachment portion 213. The bearing portion side second latching portion 212 includes an annular portion 216, a second projecting portion 217, a radial direction restricting portion 218, and a rotational direction restricting portion 219.

  The annular portion 216 is formed in an annular shape that is long in the radial direction A like the flange portion 114. The inner diameter of the annular portion 216 is the same as or slightly larger than the outer diameter of the attachment portion 213 so that the attachment portion 213 can be inserted into the annular portion 216. The outer diameter of the annular part 216 is smaller than the outer diameter of the contact rubber part 121 so that the rubber part side second hooking part 222 does not contact the paper P.

  Similar to the first protrusion 115, the second protrusion 217 is a part that hooks the rubber part 220 in the rotation direction C. The second projecting portion 217 is provided on one surface of the annular portion 216. The one side surface of the annular portion 216 is a surface facing the holding bearing portion 111 side when the bearing portion side second latching portion 212 is attached to the attachment portion 213. The shape, size, arrangement, and the like of the second protrusion 217 are the same as those of the first protrusion 115. For this reason, the four second protrusions 217 are provided on the annular portion 216 at 90 ° intervals on the same circle in the rotation direction C. Moreover, the 2nd projection part 217 has the same trunk | drum 217a as the trunk | drum 115a, and the wide part 217b same as the wide part 115b.

  The radial direction restricting portion 218 is a portion that restricts the movement of the bearing portion side second hooking portion 212 in the radial direction A with respect to the holding bearing portion 111, the bearing portion side first hooking portion 112, and the connection portion 113. The radial restricting portion 218 extends from the end surface of the annular portion 216 opposite to the second protruding portion 217 toward the opposite side of the second protruding portion 217. The radial direction restricting portion 218 is formed in a substantially cylindrical shape divided into a plurality in the rotation direction C. And each piece of the radial direction control part 218 divided | segmented into plurality is mutually spaced apart, and the clearance gap is formed between each piece. In the present embodiment, the radial direction restricting portion 218 is divided into two. The inner diameter of the radial direction restricting portion 218 is the same as the inner diameter of the annular portion 216. The outer diameter of the radial direction restricting portion 218 is the same as the outer diameter of the annular portion 216 or smaller than the outer diameter of the annular portion 216. The radial direction restricting portion 218 is brought into contact with the outer peripheral surface of the position restricting portion 214 when the attachment portion 213 is inserted into the bearing portion side second latching portion 212, whereby the holding bearing portion 111, the bearing The movement in the radial direction A of the bearing portion side second hooking portion 212 with respect to the portion side first hooking portion 112 and the connecting portion 113 is restricted.

  The rotation direction restricting portion 219 is a portion that restricts movement in the rotation direction C of the bearing side second latching portion 212 relative to the holding bearing portion 111, the bearing portion side first latching portion 112, and the connection portion 113. The rotation direction restricting portion 219 extends inward in the radial direction A from the inner peripheral surface of the radial direction restricting portion 218. In the rotational direction C, the length of the rotational direction restricting portion 219 is the same as or shorter than the separation distance of each piece of the position restricting portion 214 divided into a plurality. And the rotation direction control part 219 is inserted in the clearance gap between each piece of the position control part 214 divided | segmented into plurality when the attachment part 213 is inserted in the bearing part side 2nd latching part 212. Therefore, the movement in the rotation direction C of the bearing portion side second hooking portion 212 relative to the holding bearing portion 111, the bearing portion side first hooking portion 112 and the connection portion 113 is restricted.

  Next, how to assemble the paper feed roller 200 will be described.

  First, the bearing portion side second latching portion 212 is removed from the attachment portion 213.

  Next, the end portion on the attachment portion 213 side of the bearing portion 210 is inserted from the rubber portion side first latching portion 122 side of the rubber portion 220. Then, the holding bearing portion 111 is passed through the rubber portion 220 and the first protrusion 115 is press-fitted into the first groove portion 123.

  Next, the bearing portion side second latching portion 212 is fitted into the mounting portion 213. At this time, the rotation direction restricting portion 219 is inserted into a gap between the pieces of the position restricting portion 214 divided into a plurality of pieces. Further, the second protrusion 217 is press-fitted into the second groove 223.

  Then, the rubber part side first hook part 122 is hooked on the bearing part side first hook part 112 in the rotation direction C, and movement of the rubber part 220 in the rotation direction C with respect to the bearing part 210 is restricted. Further, the widened portion 115b bites into the side surface of the first groove portion 123, and the movement of the rubber portion 120 with respect to the bearing portion 110 in the direction of the rotation axis B is restricted. Further, the rubber part side second hooking part 222 is hooked on the bearing part side second hooking part 212 in the rotation direction C, and movement of the rubber part 220 in the rotation direction C relative to the bearing part 210 is restricted. Further, the widened portion 217b bites into the side surface of the second groove portion 223, and the movement of the rubber portion 220 relative to the bearing portion 210 in the direction of the rotation axis B is restricted. Thereby, the paper feed roller 200 in which the rubber part 220 is held on the outer peripheral surface of the bearing part 210 is obtained.

  Thus, in the paper feed roller 200 of the present embodiment, the same bearing portion as the bearing portion side first latching portion 112 is provided at the end portion of the bearing portion 210 opposite to the bearing portion side first latching portion 112. A second side hook 212 is provided. Further, a rubber part side second hooking part 222 similar to the rubber part side first hooking part 122 is provided at the end of the rubber part 220 opposite to the rubber part side first hooking part 122. As a result, since the rubber part 220 is hooked to the bearing part 210 at both ends in the rotation axis B direction, the rubber part 220 idles relative to the bearing part 210 in the rotation direction C while further suppressing twisting of the rubber part 220. Can be suppressed.

  Further, in this paper feed roller 200, the second protrusion 217 is press-fitted into the second groove part 223, so that the rubber part side second hook part 222 can be easily connected to the bearing part side second hook part in the rotation direction C. 212 can be hooked.

  Further, in this paper feed roller 200, when the second protrusion 217 is inserted into the second groove 223, the widened portion 217 b of the second protrusion 217 bites into the side surface of the second groove 223. Deviation in the rotation axis B direction of the portion 220 can be suppressed.

  Further, in this paper feed roller 200, since the bearing portion side second latching portion 212 is detachably attached to the holding bearing portion 111, when the bearing portion 210 is inserted into the rubber portion 220, the bearing portion side second engagement portion 212 is attached. By removing the two latching portions 212, the bearing portion 210 can be easily inserted into the rubber portion 220. On the other hand, after inserting the bearing part 210 into the rubber part 220, both end parts in the rotation axis B direction of the rubber part 220 are hooked in the rotation direction C by attaching the bearing part side second hooking part 212. can do.

  In the paper feed roller 200, the elastic latching portion 215 that latches the bearing-side second latching portion 212 is elastically deformed in the radial direction A. For this reason, when the bearing part 210 is inserted into the rubber part 220, the elastic latching part 215 is elastically deformed inward in the radial direction A so that the bearing part 210 can be easily inserted into the rubber part 220. On the other hand, after the bearing portion 210 is inserted into the rubber portion 220, the elastic latching portion 215 is restored to the outer side in the radial direction A and from the side opposite to the bearing portion side first latching portion 112 with respect to the holding bearing portion 111. The bearing portion side second latching portion 212 is locked. Thereby, it can suppress that the bearing part side 2nd latching | locking part 212 falls off.

[Third embodiment]
Next, a third embodiment will be described. The third embodiment is basically the same as the first embodiment, but only a part of the paper feed roller is different from the first embodiment. For this reason, below, only the matter which is different from 1st embodiment is demonstrated, and description of the matter similar to 1st embodiment is abbreviate | omitted.

  As shown in FIGS. 11 to 13, the paper feed roller 300 according to the third embodiment is a bearing unit 310 that is rotationally driven by a rotation drive shaft (not shown), and is held on the outer peripheral surface of the bearing unit 310 to form a sheet. And a rubber part 320 to be abutted.

  The rubber part 320 is the same as the rubber part 220 of the second embodiment, and only a part thereof is different from the rubber part 220. That is, the rubber part 320 includes a cylindrical contact rubber part 121 that is in contact with the paper P, a rubber part-side first hook part 122 that is hooked on the bearing part 310 in the rotation direction C, and a rotation direction C. And a rubber part side second hooking part 222 hooked on the bearing part 310.

  The bearing part 310 is basically the same as the bearing part 110 of the first embodiment. The bearing portion 310 includes a holding bearing portion 111 that holds the rubber portion 320, a bearing portion-side first hook portion 112 that hooks the rubber portion 320 in the rotation direction C, and a connection portion 113 that is meshed with the rotation drive shaft. The bearing portion side second latching portion 312 that latches the rubber portion 320 in the rotation direction C is provided.

  The bearing portion side second latching portion 312 is provided at the end of the holding bearing portion 111 opposite to the bearing portion side first latching portion 112. The bearing portion side second latching portion 312 is a protrusion in which the outer peripheral surface of the holding bearing portion 111 is raised outward in the radial direction A. For this reason, the bearing portion side second latching portion 312 is integral with the holding bearing portion 111. The bearing portion side second hooking portion 312 is inserted into the second groove portion 223 to hook the rubber portion 320 in the rotation direction C. For this reason, the same number of the second groove portions 223 as the second groove portions 223 are provided at the positions corresponding to the second groove portions 223 of the bearing portion side second latching portions 312. For this reason, the holding bearing portion 111 is provided with four bearing portion side second latching portions 312 at 90 ° intervals in the rotation direction C.

  The shape of the bearing portion side second latching portion 312 is not particularly limited. For example, as shown in FIGS. 11 and 12, the bearing portion side second latching portion 312 may have a shape in which the central portion is the highest in the rotation axis B direction and gradually decreases toward both ends. Moreover, as shown in FIG. 14, the bearing part side 2nd latching | locking part 312 becomes high as the rubber part side 1st latching part 122 approaches, and the end surface by the side of the rubber part side 1st latching part 122 is radial direction. The shape may be substantially perpendicular to A.

  In the radial direction A, the height of the bearing portion side second latching portion 312 is lower than the contact rubber portion 121 so that the bearing portion side second latching portion 12 does not abut against the paper P. However, it is preferable that the height in the radial direction A of the bearing portion side second hooking portion 312 is as low as possible so that an operator can easily insert the holding bearing portion 111 into the rubber portion 320.

  Next, how to assemble the paper feed roller 300 will be described.

  First, from the rubber part side first hook part 122 side of the rubber part 320, the end part of the bearing part 310 on the bearing part side second hook part 312 side is inserted. Then, the holding bearing portion 111 is passed through the rubber portion 320 and the first protrusion 115 is press-fitted into the first groove portion 123.

  Then, the rubber part side first hook part 122 is hooked on the bearing part side first hook part 112 in the rotation direction C, and movement of the rubber part 320 in the rotation direction C with respect to the bearing part 310 is restricted. Further, the widened portion 115b bites into the side surface of the first groove portion 123, and the movement of the rubber portion 320 with respect to the bearing portion 110 in the direction of the rotation axis B is restricted. Further, the rubber part side second hooking part 222 is hooked on the bearing part side second hooking part 312 in the rotational direction C, and the movement of the rubber part 320 in the rotational direction C relative to the bearing part 310 is restricted. Thereby, the paper feed roller 300 in which the rubber part 320 is held on the outer peripheral surface of the bearing part 310 is obtained.

  As described above, in the paper feed roller 300 according to the present embodiment, the bearing portion side second latching portion 312 is integrated with the holding bearing portion 111, so that the bearing portion 310 can be easily manufactured, and the paper feed roller 300 can be easily assembled.

  Further, in this paper feed roller 300, since the bearing portion side second latching portions 312 are dispersed at four locations, the resistance when the holding bearing portion 111 is inserted into the rubber portion 320 can be reduced. Thereby, the sheet feeding roller 300 can be easily assembled.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the paper feed roller according to the present invention is applied to a roller that picks up the paper P from the cassette K, but may be applied to a roller that transports the paper P in another position of the image forming apparatus. . Further, the image forming apparatus to which the paper feed roller according to the present invention is applied may be a multi-function machine having a printer function and a copying function, a printer, a copying machine, a facsimile machine, or the like. Moreover, in the said embodiment, the width | variety of at least one part of the 1st projection part was demonstrated as a thing larger than the width | variety of a 1st groove part in a rotation direction. However, the width of at least a part of the first protrusion may be larger than the width of the first groove in the radial direction orthogonal to the rotation axis direction. Similarly, in the said embodiment, although the width | variety of at least one part of the 2nd projection part was demonstrated as a thing larger than the width | variety of a 2nd groove part in a rotation direction. However, the width of at least a part of the second protrusion may be larger than the width of the second groove in the radial direction orthogonal to the rotation axis direction.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Recording medium conveyance unit, 12 ... Bearing part side 2nd latching part, 20 ... Developing apparatus, 21 ... Developing roller, 30 ... Transfer unit, 31 ... Transfer belt, 31a, 31b, 31c, 31d: Suspension roller, 32 ... Primary transfer roller, 33 ... Secondary transfer roller, 40 ... Photosensitive drum, 41 ... Charging roller, 42 ... Exposure unit, 43 ... Cleaning unit, 50 ... Fixing unit, 52 ... Heating roller, 54 DESCRIPTION OF SYMBOLS ... Pressure roller, 62, 64 ... Discharge roller, 100 ... Feed roller, 110 ... Bearing part, 111 ... Holding bearing part, 112 ... Bearing part side 1st latching part, 113 ... Connection part, 114 ... Flange part, 115: First protrusion 115a: Body part 115b Wide part 120 ... Rubber part 121 Rubber contact part 122 Rubber part first hook part 123 First groove part 200 Paper feed 210, bearing portion, 212 ... second latching portion on the bearing portion, 213 ... mounting portion, 214 ... position restricting portion, 215 ... elastic latching portion, 215a ... leaf spring portion, 215b ... hook portion, 216 ... Annular part, 217 ... second projection part, 217a ... trunk part, 217b ... widening part, 218 ... radial direction restricting part, 219 ... rotational direction restricting part, 220 ... rubber part, 222 ... rubber part side second latching part 223 ... second groove portion, 300 ... feed roller, 310 ... bearing portion, 312 ... second retaining portion on bearing side, 320 ... rubber portion, B ... rotation axis, C ... rotation direction, D ... contact area, E ... non-contact area, K ... cassette, N ... toner tank, P ... paper, R1 ... conveyance path, R2 ... secondary transfer area.

Claims (12)

A bearing that is rotationally driven by the rotational drive shaft;
A rubber roller that is held on the outer peripheral surface of the bearing portion and is in contact with the paper,
The bearing portion is
A holding bearing portion for holding the rubber portion;
A bearing part side first latching part for latching the rubber part in the rotation direction of the bearing part and the rubber part,
The rubber part is
A cylindrical abutting rubber portion that abuts against the paper;
A rubber part side first hooking part hooked on the bearing part side first hooking part in the rotation direction,
The rubber part side first latching part is provided in a non-contact area where the rubber part is not in contact with the paper in the rotation axis direction of the bearing part and the rubber part.
Feed roller. The rubber part side first latching part has a first groove part extending in the rotation axis direction,
The bearing part side first latching part has a first protrusion part press-fitted into the first groove part,
The paper feed roller according to claim 1. The width of at least a part of the first protrusion is larger than the width of the first groove in the rotation direction.
The paper feed roller according to claim 2. The width of at least a part of the first protrusion is larger than the width of the first groove in the radial direction orthogonal to the rotation axis direction.
The paper feed roller according to claim 2. The bearing portion side first latching portion is provided at one end of the bearing portion,
The rubber part side first latching part is provided at an end part on one side of the rubber part,
The paper feed roller according to any one of claims 1 to 4. The bearing portion is provided at an end of the bearing portion opposite to the bearing portion side first latching portion, and a bearing portion side second latching portion that latches the rubber portion in the rotation direction. Have
The rubber part is provided at an end of the rubber part opposite to the first hook part on the rubber part side and is hooked on the second hook part on the bearing part side in the rotational direction. Side second latching part,
The rubber part side second hooking part is provided in the non-contact area.
The paper feed roller according to claim 5. The rubber part side second latching part has a second groove part extending in the rotation axis direction,
The bearing part side second latching part has a second protrusion part press-fitted into the second groove part,
The paper feed roller according to claim 6. The width of at least a part of the second protrusion is larger than the width of the second groove in the rotation direction.
The paper feed roller according to claim 7. The width of at least a part of the second protrusion is larger than the width of the second groove in the radial direction orthogonal to the rotation axis direction.
The paper feed roller according to claim 7 or 8. The bearing portion side second latching portion is detachably attached to the holding bearing portion.
The paper feed roller according to any one of claims 6 to 9. The bearing portion has an elastic latching portion that extends to the opposite side of the bearing portion side first latching portion and elastically deforms in the radial direction of the rubber portion,
The bearing portion side second latching portion is latched on the elastic latching portion from the opposite side of the bearing portion side first latching portion with respect to the holding bearing portion.
The paper feed roller according to claim 10.   An image forming apparatus comprising the paper feed roller according to claim 1.

Images