JP2022129304A - Sheet conveyance device and image forming device - Google Patents

Abstract

To provide a sheet conveyance device capable of improving the assemblability of a member for grounding a rotary shaft, and capable of proper electricity conduction.SOLUTION: An image forming device 1 includes: a register roller 35a having a metal rotary shaft 351; a conveyance frame 31 for supporting the rotary shaft 351; an earth spring 82 having a first end part 82b connected to the rotary shaft 351 and a circular second end part 82c; and an earth sheet metal 37 that is grounded, and inserted into the conveyance frame 31 via a slit 314 formed at the conveyance frame 31 and coming into contact with the second end part 82c. The conveyance frame 31 includes a spring support part 313 to which the second end part 82c comes into contact. The second end part 82c can move between a first position to come into contact with the spring support part 313, and a second position to come into contact with the earth sheet metal 37. An upper side edge part 314a on the second position side in the movement direction of the second end part 82c of the slit 314 is positioned further on the first position side than a center C in the movement direction of the second end part 82c in the first position.SELECTED DRAWING: Figure 11

Description

The present invention relates to a sheet conveying device and an image forming apparatus.

Conventionally, in a sheet conveying device provided in an image forming apparatus, a conveying roller is used for conveying a sheet, and when the rotating shaft of the conveying roller is made of metal, it is necessary to ground the rotating shaft. .

Various configurations for grounding the rotating shaft have been devised. For example, in Japanese Unexamined Patent Application Publication No. 2002-100000, the rotating shaft is grounded by electrically connecting the rotating shaft of the conveying roller and a metal reinforcing member using a grounding member made of spring steel or the like.

Further, in Patent Document 2, a metal plate spring that is grounded on a metal structure is directly pressed against a metal rotating shaft, so that the rotating shaft and the structure are electrically connected to each other. I am grounded.

JP 2019-026406 A Japanese Patent Application Laid-Open No. 2001-341881

As described above, when grounding the rotating shaft of the transport roller, it is necessary to connect a plurality of members to establish electrical continuity. may occur, which may complicate the assembly of the parts. In addition, if the assembly of the members becomes complicated, the connected members are not properly connected to each other, resulting in incomplete grounding of the rotating shaft, which causes disturbance of the image in the image forming apparatus and adversely affects the electronic equipment inside the apparatus. may cause it to occur.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a sheet conveying apparatus and an image forming apparatus capable of improving the ease of assembly of a member for grounding the rotating shaft of a conveying roller and allowing the members to be properly connected to each other.

A sheet conveying device and an image forming apparatus that solve the above problems have the following features.

That is, the sheet conveying device has a rotating shaft made of metal, and includes a conveying roller that conveys a sheet, a frame member that supports the rotating shaft, a first end connected to the rotating shaft, and a circular shape. a ground spring having a second end formed thereon and grounded and passed through the frame member through a slit formed in the frame member to contact the second end of the ground spring. a grounding sheet metal that is detachable from the frame member, the frame member contacting the second end of the grounding spring when the grounding sheet metal is detached from the frame member. The second end of the ground spring has a first position abutting against the spring support when the ground sheet metal is removed from the frame member, and the ground sheet metal contacts the frame member. and a second position in which the second end of the slit is in contact with the ground sheet metal in a state of being attached to a member, and the second end of the slit in the movement direction between the first position and the second position. The edge portion on the 2nd position side is located on the first position side of the center of the second end portion located at the first position in the moving direction.

As a result, it is possible to improve the assembling property of the ground metal plate for grounding the rotating shaft, and to properly conduct the ground metal plate and the ground spring.

Further, the frame member has a support wall that is arranged adjacent to the ground spring in the axial direction of the rotating shaft and supports the rotating shaft, and the frame member has a support wall that supports the rotating shaft, and the ground spring is interposed in the axial direction. A rib member located on the opposite side of the support wall and protruding toward the ground spring is provided.

As a result, the rib member restricts the movement of the second end portion of the ground spring in the axial direction, suppresses the second end portion from falling off from the ground metal plate, and prevents the ground spring from falling off from the ground metal plate. good continuity can be maintained.

Further, the rib member protrudes in the axial direction to a position overlapping with the ground metal plate attached to the frame member when viewed in a direction orthogonal to the axial direction.

Thus, the rib member can further prevent the second end of the ground spring from coming off the ground metal plate.

The spring support portion of the frame member protrudes from the support wall toward the rib member in the axial direction to a position having a gap with the rib member, and the gap is the ground. It is smaller than the axial width of the second end of the spring.

Accordingly, it is possible to prevent the second end portion of the ground spring, which has moved in the axial direction, from passing through the gap and falling off from the spring support portion.

Further, a metallic guide member for guiding the sheet to the conveying roller is provided on the upstream side of the conveying roller in the sheet conveying direction, and the guide member and the ground metal plate are electrically connected.

As a result, the guide member can be grounded through the grounding sheet metal.

A grounded metal frame is provided, and the grounding sheet metal includes a first portion that contacts the contact surface of the frame member, a second portion that is fixed to the fixing surface of the metal frame, the first portion and the a third portion connected to the second portion and bent with respect to the first portion and the second portion; and the third portion is in contact with the restricting surface.

As a result, deformation of the ground metal plate can be suppressed when the second portion of the ground metal plate is fixed to the fixing surface of the metal frame.

Further, a harness having a connector connected to one end thereof is provided, and the frame member includes a holding hole formed to hold the rotating shaft and to have a size through which the connector can pass, and a holding hole extending radially outward from the holding hole. and a through groove extending through the harness through which the harness can pass.

As a result, there is no need to separately provide a hole for allowing the connector of the harness to pass between the outside and the inside of the frame member, and the strength of the frame member can be maintained. In addition, the harness connected to the connector that has passed through the frame member through the holding hole can be routed through the through groove into the frame member, so that the space for routing the harness can be reduced and the size of the device can be reduced.

Further, the frame member has a protrusion that protrudes into the through-groove at an intermediate portion in the extending direction of the through-groove and restricts the harness passing through the through-groove from moving toward the holding hole.

Thereby, the harness passing through the through groove can be held at a desired position.

Further, the ground sheet metal includes a substrate arranged at one end portion of the frame member in the axial direction and arranged at an end portion opposite to the ground sheet metal across the conveying roller in the axial direction, A harness extends in the axial direction below the transport roller and has the other end connected to the substrate.

As a result, the harness connected to the substrate can be routed around in a space-saving manner within the frame member.

Further, an image forming apparatus includes: the sheet conveying device according to any one of claims 1 to 9; and an image forming section that forms an image on the sheet conveyed by the sheet conveying device.

As a result, in the image forming apparatus, it is possible to improve the assembling property of the ground metal plate for grounding the rotating shaft, and to properly conduct the ground metal plate and the ground spring.

ADVANTAGE OF THE INVENTION According to this invention, while improving the assembly|attachment property of the ground metal plate for grounding a rotating shaft, an earth metal plate and a ground spring can be electrically connected appropriately.

1 is a central sectional view showing an image forming apparatus; FIG. 2 is a perspective view showing the inside of an apparatus main body in the image forming apparatus; FIG. 3 is a perspective view showing a sheet conveying unit; FIG. 3 is a central sectional view showing a sheet conveying unit; FIG. 4 is a perspective view showing the left end portion of the sheet conveying unit; FIG. FIG. 10 is a side cross-sectional view showing the left end of the sheet conveying unit, showing a state where the second end of the ground spring is in contact with the ground metal plate; FIG. 10 is a side cross-sectional view showing the left end of the sheet conveying unit, showing a state where the second end of the ground spring is in contact with the spring support; FIG. 11 shows a ground spring; It is a perspective view which shows a ground metal plate. FIG. 4 is a perspective view showing a grounding sheet metal attached to a carrier frame; FIG. 4B is a side cross-sectional view showing the second end of the ground spring in the first position; 3 is a front cross-sectional view showing the left end portion of the sheet conveying unit; FIG. 3 is a plan sectional view showing the left end portion of the sheet conveying unit; FIG. FIG. 8A is a side view showing the right end portion of the sheet conveying unit, in which (a) shows a state in which the substrate is not attached to the second support wall, and (b) shows a state in which the substrate is attached to the second support wall; It is a figure which shows the state which is. 3 is a front cross-sectional view showing a sheet conveying unit; FIG.

Next, a mode for carrying out the present invention will be described with reference to the accompanying drawings.

[Image forming device]
An image forming apparatus 1 shown in FIG. 1 is an embodiment of an image forming apparatus equipped with a sheet conveying device according to the present invention, and is a color laser printer that forms images of multiple colors on a sheet S by electrophotography. .

In the following description, the right side in FIG. 1 is defined as the front side of the image forming apparatus 1, the left side in FIG. The back side of the paper is defined as the right side of the image forming apparatus 1 . Further, the upper side and the lower side in FIG. 1 are defined as the upper side and the lower side of the image forming apparatus 1, respectively.

The image forming apparatus 1 includes an apparatus main body 2, a sheet feeding section 3 having a sheet feeding tray 10 for supporting a sheet S and a sheet conveying unit 30 for conveying the sheet S, and a sheet S conveyed by the sheet feeding section 3. and an image forming unit 5 for forming an image. The sheet conveying unit 30 is an example of a sheet conveying device.

The apparatus main body 2 is formed in a substantially rectangular parallelepiped shape, and accommodates the paper feeding section 3 and the image forming section 5 . An opening 2A is opened in the upper surface of the apparatus main body 2, and the apparatus main body 2 has a top cover 23 capable of opening and closing the opening 2A.

The top cover 23 is configured to be rotatable about a rotating shaft 23a at its rear end, and rotates about the rotating shaft 23a to move between a closed position for closing the opening 2A and a closed position for closing the opening 2A. It is movable between an open position to open 2A. A top cover 23 of the apparatus main body 2 is formed with a discharge tray 23b that slopes downward from the front side to the rear side.

The paper feeding section 3 is arranged in the lower part of the apparatus main body 2 and conveys the sheet S supported by the paper feeding tray 10 to the image forming section 5 by the sheet conveying unit 30 . The paper feed tray 10 is configured to be slidable in the front-rear direction, and is configured to be movable between an accommodation position accommodated in the apparatus main body 2 and a separation position pulled forward from the accommodation position.

The sheet conveying unit 30 includes a conveying frame 31, a paper feed roller 32, a separation roller 33, a conveying roller 34a, a registration roller 35a, and a guide member . The registration roller 35a is an example of a conveying roller that conveys a sheet. The paper feed unit 3 includes a separation pad 33 a arranged to face the separation roller 33 . In the apparatus main body 2, a conveying path P for the sheet S is configured from the paper feed tray 10 to the paper discharge tray 23a via the image forming section 5. As shown in FIG.

The sheets S supported by the paper feed tray 10 are separated one by one by the paper feed roller 32, the separation roller 33 and the separation pad 33a, and sent to the transport path P. As shown in FIG. The paper feed roller 32 is a roller that conveys the sheet S from the paper feed tray 10 toward the image forming section 5 . The separation roller 33 and the separation pad 33a constitute separation means for separating the sheets S supported by the paper feed tray 10 one by one.

The sheet S sent to the conveying path P is conveyed to the image forming section 5 by a conveying roller 34a and a roller 34b arranged to face the conveying roller 34a, and a registration roller 35a and a registration roller 35b arranged to face the registration roller 35a. transported towards

The guide member 36 is located upstream of the registration roller 35a in the sheet conveying direction, and guides the sheet S conveyed by the conveying roller 34a to the registration roller 35a. The guide member 36 is made of a metal member. The registration rollers 35a regulate the movement of the leading edge of the conveyed sheet S to temporarily stop it, and then convey the sheet S toward the image forming unit 5 at a predetermined timing.

A pre-registration sensor S1 is arranged upstream of the registration roller 35a in the sheet conveying direction, and a post-registration sensor S2 is arranged downstream of the registration roller 35a in the sheet conveying direction.

The pre-registration sensor S1 and the post-registration sensor S2 are sensors for detecting the sheet S being conveyed. When the position S2 is reached, the pre-registration sensor S1 and the post-registration sensor S2 are turned on to detect the sheet S. When the trailing edge of the sheet S transported along the transport path P in the transport direction reaches the positions of the pre-registration sensor S1 and the post-registration sensor S2, the pre-registration sensor S1 and the post-registration sensor S2 are turned off, and the sheet S is transported. no longer detected.

The feed roller 32 , separation roller 33 , transport roller 34 a , registration roller 35 a , registration roller 35 b , guide member 36 , pre-registration sensor S<b>1 , and post-registration sensor S<b>2 are supported by transport frame 31 . Separation pad 33 a and roller 34 b are supported by paper feed tray 10 .

The image forming section 5 is arranged above the paper feeding section 3 and has four process cartridges 50 arranged side by side in the front-rear direction. Each process cartridge 50 is provided for each color of black, yellow, magenta, and cyan. The process cartridge 50 is detachably attached to the apparatus main body 2 . The process cartridge 50 includes a photosensitive drum 51 , a developing roller 52 , a supply roller 53 and a charger 54 .

The process cartridge 50 is mounted in the apparatus main body 2 in such a posture that the axis of the photosensitive drum 51 extends in the horizontal direction. The developing roller 52 is configured to be movable between a contact position where it contacts the photosensitive drum 51 and a separated position where it separates from the photosensitive drum 51 . The supply roller 53 supplies toner contained in the process cartridge 50 to the developing roller 52 .

The apparatus main body 2 has an exposure head 59 that exposes the surface of the photosensitive drum 51 . The exposure head 59 is supported by the top cover 23 . Four exposure heads 59 are provided corresponding to each photosensitive drum 51, and each exposure head 59 is arranged side by side in the front-rear direction. The exposure head 59 extends downward from the top cover 23 and has an exposure portion 59a at its lower end. The exposure unit 59a is arranged above and close to the photosensitive drum 52 when the top cover 23 is closed. The exposure unit 59a is configured by an LED array having a plurality of LED elements arranged side by side in the left-right direction.

A transfer belt 41 is arranged below the photosensitive drum 51 with the transport path P interposed therebetween. The transfer belt 41 is stretched between a drive roller 42 and a driven roller 43 arranged in front of the drive roller 42 . A belt device 40 is configured by the transfer belt 41 , the drive roller 42 , and the driven roller 43 . Transfer rollers 44 are arranged at positions facing the respective photosensitive drums 51 with the transfer belt 41 interposed therebetween.

In the image forming section 5 , the photosensitive drums 51 uniformly charged by the charger 54 are selectively exposed by the exposure heads 59 . This exposure selectively removes charges from the surface of the photosensitive drum 51 and forms an electrostatic latent image on the surface of the photosensitive drum 51 .

The toner contained in the process cartridge 50 is positively charged between the supply roller 53 and the developing roller 52 and carried on the surface of the developing roller 52 . A developing bias is applied to the developing roller 52 , and when the electrostatic latent image formed on the photosensitive drum 51 faces the developing roller 52 , the potential difference between the electrostatic latent image and the developing roller 52 causes the developing roller 52 to supplies toner to the electrostatic latent image. Thereby, a toner image is formed on the surface of the photosensitive drum 51 .

When the sheet S conveyed toward the image forming unit 5 reaches the transfer belt 41 , it is conveyed by the transfer belt 41 and sequentially passes between the transfer belt 41 and each photosensitive drum 51 . Then, the toner image on the surface of the photosensitive drum 51 is transferred onto the sheet S by the transfer bias applied to the transfer roller 44 when facing the sheet S. As shown in FIG.

In this embodiment, the transfer belt 41 is configured as a conveying belt that conveys the sheet S onto which the toner image is transferred. It is also possible to construct an intermediate transfer belt to be transferred to S.

The sheet S onto which the toner image has been transferred is conveyed to the fixing device 60 . The fixing device 60 has a heating roller 61 and a pressure roller 62 that presses against the heating roller 61 . The toner image is thermally fixed on the surface.

The sheet S on which the toner image is thermally fixed is conveyed from the fixing device 60 to the downstream side in the conveying direction. It is conveyed by pair 64 and ejected to paper ejection tray 23b.

As shown in FIG. 2, the apparatus main body 2 includes a first main body frame 24 and a second main body frame 25 which are arranged apart from each other in the left-right direction. The first body frame 24 is located at the right end of the device body 2 and extends in the front-back direction and the up-down direction. The second body frame 25 is located at the left end of the device body 2 and extends in the front-back direction and the up-down direction.

[Sheet transport unit]
As shown in FIGS. 2 and 3, the sheet conveying unit 30 includes a front frame 26 extending in the left-right direction and connecting the first body frame 24 and the second body frame 25 . The front frame 26 connects the first body frame 24 and the second body frame 25 at the front end and upper portion of the device body 2 . The front frame 26 is formed of a sheet metal member and is grounded. The front frame 26 is an example of a grounded metal frame.

The conveying frame 31 of the sheet conveying unit 30 is arranged between the first body frame 24 and the second body frame 25 at the front end of the apparatus body and below the front frame 26 . The transport frame 31 is supported by the first body frame 24 and the second body frame 25 .

As shown in FIGS. 4 to 7, the registration roller 35a has a rotating shaft 351 made of metal that extends in the left-right direction, and is configured to be rotatable about the axis X of the rotating shaft 351. . The sheet conveying unit 30 has a bearing 81 that supports the left end of the rotating shaft 351 . The bearing 81 has a bearing portion 81a that supports the rotating shaft 351, and a locking portion 81b that extends radially outward from the bearing portion 81a.

The transport frame 31 has a first support wall 311 that supports the left end of the rotating shaft 351 . The first support wall 311 is positioned at the left end of the transport frame 31 . The first support wall 311 is an example of a support wall arranged adjacent to the ground spring and supporting the rotating shaft. The rotary shaft 351 is rotatably supported by the first support wall 311 via the bearing portion 81 a of the bearing 81 . The transport frame 31 is an example of a frame member that supports the rotating shaft.

The sheet conveying unit 30 has an earth spring 82 supported by a bearing 81 . As shown in FIG. 8, the ground spring 82 is a wire spring formed by processing a wire rod, and has a support portion 82a, a first end portion 82b, and a second end portion 82c.

The support portion 82a is formed in a circular shape by winding a wire rod a plurality of times, and is fitted to the bearing portion 81a of the bearing 81. As shown in FIG. The earth spring 82 is supported by the bearing 81 by fitting the support portion 82a to the bearing portion 81a. The first end portion 82 b extends radially outward from the support portion 82 a and is locked to the locking portion 81 b of the bearing 81 . By locking the first end portion 82b to the locking portion 81b, the ground spring 82 as a whole is restricted from rotating in the circumferential direction.

The bearing 81 is formed of a conductive member, and the support portion 82a is fitted to the bearing portion 81a, and the first end portion 82b is locked to the locking portion 81b, thereby connecting the bearing 81 and the earth spring 82 together. are in contact and are electrically connected. That is, the bearing 81 and the earth spring 82 are electrically connected. The second end portion 82c extends radially outward from the support portion 82a, and has a circular tip formed by winding a wire material multiple times. That is, the second end portion 82c is formed in a circular shape.

The conveying frame 31 includes a front wall 312 positioned at a front end and facing in the front-rear direction, a spring support portion 313 extending rearward from the front wall 312 , and a front wall 312 passing through the front wall 312 above the spring support portion 313 in the front-rear direction. It has a slit 314 that The spring support portion 313 is formed in a flat plate shape facing in the vertical direction, and the slit 314 is formed in a rectangular shape elongated in the horizontal direction. The second end portion 82c of the ground spring 82 can contact the upper surface of the spring support portion 313, and has a downward biasing force when in contact with the upper surface of the spring support portion 313 (see FIG. 7). ing.

The sheet conveying unit 30 has a ground metal plate 37 attached to the front wall 312 of the conveying frame 31 . The ground metal plate 37 is formed of a metal plate member and is grounded. The ground metal plate 37 is positioned at the left end of the transfer frame 31 . The left end is an example of one end in the X-axis direction.

As shown in FIGS. 9 and 10, the ground metal plate 37 includes a body portion 37a, a conducting portion 37b, a first fixing portion 37c, a contact portion 37d, a second fixing portion 37e, and a restricting portion 37f. have. The main body portion 37a extends in the vertical direction, and abuts on the front wall 312 of the transport frame 31 with its plate surface facing in the front-rear direction.

The conductive portion 37b is connected to the lower and right portion of the main body portion 37a, and is formed by bending a sheet metal member rearward from the main body portion 37a. The conductive portion 37b has a plate surface facing in the vertical direction, and is inserted through the slit 314 of the front wall 312 from the front.

As shown in FIGS. 5 and 6 , the conductive portion 37 b inserted through the slit 314 is positioned above the spring support portion 313 behind the front wall 312 . In the state in which the conductive portion 37b is inserted through the slit 314, the second end portion 82c of the ground spring 82 is in contact with the upper surface of the conductive portion 37b. The second end portion 82c of the ground spring 82 has a downward biasing force when in contact with the upper surface of the conducting portion 37b (see FIG. 6).

The ground spring 82 and the ground metal plate 37 are electrically connected by the second end 82c of the ground spring 82 coming into contact with the upper surface of the conducting portion 37b. Since the second end portion 82c in contact with the upper surface of the conductive portion 37b has a downward biasing force, the ground spring 82 and the ground metal plate 37 can be properly connected.

The first fixing portion 37c extends downward from the lower end of the main body portion 37a, and is fixed to the front wall 312 of the transport frame 31 by being fastened with a fastening member such as a screw. At the boundary between the body portion 37a and the first fixing portion 37c, the sheet metal member is bent to form a stepped portion 37g. Since the stepped portion 37g is formed between the main body portion 37a and the first fixing portion 37c, the rigidity of the ground metal plate 37 is improved. It is possible to suppress deformation of the sheet metal 37 .

As shown in FIGS. 3 and 10, a connection piece 36a extends leftward from the left end of the guide member 36, and the connection piece 36a and the first fixing portion 37c are fastened together to the front wall 312 by a fastening member. It is The connection piece 36a and the first fixing portion 37c are in contact with each other and are electrically connected by being fastened together. In other words, the guide member 36 and the ground metal plate 37 are electrically connected. Since the ground metal plate 37 is grounded, the guide member 36 can be grounded through the ground metal plate 37 by conducting the guide member 36 and the ground metal plate 37 .

The contact portion 37d is connected to the upper and left end portions of the body portion 37a and extends vertically. The plate surface of the contact portion 37d faces the front-rear direction. The conveying frame 31 has a contact surface 315 on the left and upper end of the front wall 312, which faces forward and faces the contact portion 37d in the front-rear direction. A contact portion 37 d of the ground metal plate 37 is in contact with the contact surface 315 . The contact portion 37d is an example of the first portion of the ground metal plate. At the boundary between the body portion 37a and the contact portion 37d, the sheet metal member is bent to form a step portion 37h. The ground metal plate 37 has a stepped portion 37h between the body portion 37a and the contact portion 37d, thereby improving rigidity.

The plate surface of the second fixing portion 37e faces the front-rear direction, and is fixed to the front surface 26a of the front frame 26 by being fastened with a fastening member such as a screw. By fixing the second fixing portion 37e to the front surface 26a, the ground metal plate 37 and the front frame 26 are brought into contact with each other and electrically connected, so that the ground metal plate 37 can be grounded. The front surface 26a of the front frame 26 is an example of a fixing surface of the metal frame, and the second fixing portion 37e is an example of a second portion fixed to the fixing surface of the metal frame.

The restricting portion 37f connects the contact portion 37d and the second fixing portion 37e, and has a plate surface facing in the left-right direction. The restricting portion 37f is an example of a third portion that connects the first portion and the second portion. The restriction portion 37f is formed by bending a sheet metal member with respect to the contact portion 37d and the second fixing portion 37e. The conveying frame 31 has a regulation surface 316 formed continuously from the right end of the contact surface 315 and facing rightward. The regulation surface 316 intersects the contact surface 315 of the transport frame 31 and the front surface 26 a of the front frame 26 . The restricting portion 37 f abuts on the restricting surface 316 .

The restricting portion 37f is bent with respect to the contact portion 37d and the second fixing portion 37e, and forms a step portion formed between the contact portion 37d and the second fixing portion 37e. The ground metal plate 37 has a restricting portion 37f between the contact portion 37d and the second fixing portion 37e, thereby improving rigidity.

The ground sheet metal 37 has improved rigidity due to the restricting portion 37f, and the restricting portion 37f is in contact with the restricting surface 316. Therefore, when the second fixing portion 37e is fastened to the front surface 26a of the front frame 26, the sheet metal A force tending to deform the member can be received by the restricting surface 316 . Thereby, when the second fixing portion 37 e is fixed to the front surface 26 a of the front frame 26 , deformation of the ground metal plate 37 can be suppressed.

The ground metal plate 37 can be removed from the transfer frame 31 by releasing the fixing of the first fixing portion 37c to the front wall 312 and the fixing of the second fixing portion 37e to the front surface 26a. Therefore, the sheet conveying unit 30 has a state in which the ground sheet metal 37 is attached to the conveying frame 31 (state shown in FIG. 6) and a state in which the ground sheet metal 37 is removed from the conveying frame 31 (state shown in FIG. 7). can take

As shown in FIG. 7, when the ground metal plate 37 is removed from the transfer frame 31, the second end 82c of the ground spring 82 is moved to the first position where it abuts on the upper surface of the spring support portion 313. As shown in FIG. Become. On the other hand, as shown in FIG. 6, in a state in which the ground metal plate 37 is attached to the conveying frame 31 and the conductive portion 37b is inserted through the slit 314 behind the front wall 312 of the conveying frame 31, the ground spring The second end 82c of 82 is in a state of being moved to the second position in contact with the upper surface of the conducting portion 37b. When the second end portion 82c of the ground spring 82 is in the second position where it contacts the conductive portion 37b, the ground spring 82 and the ground metal plate 37 are electrically connected, and the rotary shaft 351 is grounded.

When the ground sheet metal 37 is removed from the conveying frame 31 and the second end 82c of the ground spring 82 is at the first position, when the conductive portion 37b of the ground sheet metal 37 is inserted through the slit 314, the second end 82c is pushed upward by the inserted conducting portion 37b and moves to the second position. Conversely, when the ground sheet metal 37 is attached to the conveying frame 31 and the second end 82c of the ground spring 82 is at the second position, when the ground sheet metal 37 is removed, the second end 82c is attached downward. Move to the first position by force.

Thus, the second end portion 82c of the ground spring 82 is movable between a first position in contact with the spring support portion 313 and a second position in contact with the conduction portion 37b. In this embodiment, the movement direction between the first position and the second position of the second end portion 82c is the vertical direction.

As shown in FIG. 11, the slit 314 has an upper edge portion 314a, which is the edge portion on the second position side in the moving direction between the first position and the second position of the second end portion 82c. Also, the circular center C of the second end portion 82c of the ground spring 82 is the center in the moving direction between the first position and the second position of the second end portion 82c. The upper edge portion 314a of the slit 314 is located on the first position side by a distance D from the center C in the movement direction between the first position and the second position of the second end portion 82c at the first position. is doing.

In such a configuration, even if the conductive portion 37b of the ground sheet metal 37 is inserted through the slit 314 and is closest to the upper edge portion 314a of the slit 314, the conductive portion 37b is It abuts below the center C of the circular shape of the second end portion 82c at the 1st position. Therefore, when the conducting portion 37b is inserted through the slit 314, the conducting portion 37b always hits below the center C of the circular shape of the second end portion 82c regardless of the vertical position of the conducting portion 37b when it is inserted through the slit 314. will come into contact with

The conducting portion 37b is brought into contact with the second end portion 82c below the center C of the circular shape of the second end portion 82c, so that the conducting portion 37b slips below the second end portion 82c along the circular shape of the second end portion 82c. , and the second end 82c can be smoothly pushed upward and moved to the second position. As a result, it is possible to improve the assembling property of the ground metal plate 37 for grounding the rotating shaft 351 and to properly connect the ground metal plate 37 and the ground spring 82 .

As shown in FIGS. 12 and 13 , an input gear 352 is fixed to the left end of the rotating shaft 351 to which a driving force to the rotating shaft 351 is input. A gear cover 38 that covers the input gear 352 from the left side is attached to the left end portion of the transport frame 31 . The gear cover 38 is positioned to the left of the earth spring 82 in the axial center X direction of the rotating shaft 351 . The gear cover 38 has a rib 381 that protrudes rightward on the side of the ground spring 82 in the axial center X direction.

The first support wall 311 of the conveying frame 31 is arranged adjacent to the right side of the ground spring 82 in the axial center X direction, and the rib 381 is the first supporting wall 311 sandwiching the ground spring 82 in the axial center X direction. It is located on the opposite side of wall 311 . The rib 381 is an example of a rib member protruding toward the ground spring. The rib 381 protrudes to the right in the X-axis direction to a position where it overlaps the conductive portion 37b of the ground metal plate 37 attached to the conveying frame 31 by a distance W2 when viewed in the direction orthogonal to the X-axis direction.

The second end portion 82c of the ground spring 82 has elasticity, and if an impact is applied to the image forming apparatus 1 during normal use or when the image forming apparatus 1 is dropped, for example, the second end portion 82c moves toward the axis X. It can move in any direction. When the second end portion 82c moved in the direction of the axis X moves to the left of the left end of the conducting portion 37b, the second end portion 82c drops out of contact with the upper surface of the conducting portion 37b, and the earth spring 82 and the earth spring 82 move. There is a possibility that the state of continuity with the ground metal plate 37 will be cancelled.

However, since the sheet conveying unit 30 has the rib 381 projecting toward the ground spring 82, the rib 381 can restrict the leftward movement of the second end portion 82c in the axial center X direction. It is possible to prevent the second end portion 82c from coming off the conducting portion 37b. Accordingly, proper conduction between the ground spring 82 and the ground metal plate 37 can be maintained.

In particular, since the rib 381 protrudes in the direction of the axis X to a position where it overlaps with the conducting portion 37b when viewed from the direction orthogonal to the direction of the axis X, the apparatus is subjected to shock when the ground sheet metal 37 is attached to the transfer frame 31. When applied, the leftward movement of the second end portion 82c can be effectively restricted. This makes it possible to further prevent the second end portion 82c from falling off from the conducting portion 37b.

The spring support portion 313 of the transfer frame 31 protrudes leftward from the first support wall 311 toward the rib 381 in the direction of the axis X. As shown in FIG. The spring support portion 313 protrudes to a position having a gap W3 between itself and the rib 381 in the axial center X direction. As shown in FIG. 8B, the circular portion of the second end 82c of the ground spring 82 has a width W1 in the axial center X direction. The gap W3 is smaller than the width W1.

Thus, the gap W3 between the spring support portion 313 and the rib 381 is formed smaller than the width W1 of the second end portion 82c. Therefore, even if the ground sheet metal 37 is removed from the conveying frame 31 and the second end portion 82c is in contact with the spring support portion 313 and an impact is applied to the device, the second end portion 37 moved to the left in the axial center X direction. It is possible to prevent the end portion 82c from passing through the gap W3 and falling off from the spring support portion 313 .

As shown in FIG. 14, the transport frame 31 has a second support wall 317 that holds the right end of the rotating shaft 351 of the registration roller 35a. The second support wall 317 is positioned at the right end of the transport frame 31 . The sheet conveying unit 30 has a bearing 83 that supports the right end of the rotating shaft 351 . The second support wall 317 has a holding hole 317a into which the bearing 83 is fitted. The holding hole 317a penetrates the second support wall 317 in the left-right direction. The rotary shaft 351 is rotatably held by the second support wall 317 via a bearing 81 fitted in the holding hole 317a.

The second support wall 317 has a through groove 317b extending radially outward from the outer peripheral edge of the holding hole 317a. The through groove 317b penetrates the second support wall 317 in the left-right direction. The through groove 317b extends forward and downward from the outer peripheral edge of the holding hole 317a and then extends downward.

As shown in FIGS. 14 and 15, the second support wall 317 has an outer surface 317A facing rightward, which is the outer side of the transfer frame 31 in the left-right direction, and a left side surface, which is the inner side of the transfer frame 31 in the left-right direction. It has a facing inner surface 317B. A substrate 84 is attached to the outer surface 317A of the second support wall 317 . A pre-registration sensor S1 and a post-registration sensor S2 are mounted on the substrate 84 . The substrate 84 is arranged at the right end opposite to the ground metal plate 37 with the registration roller 35a interposed therebetween in the axial center X direction.

The sheet conveying unit 30 has a harness 85 having one end connected to a connector 86 and the other end connected to a connector 87 . A connector 87 connected to the other end of the harness 85 is mounted on the board 84 . The holding hole 317a of the second support wall 317 is formed in a size that allows the connector 86 connected to one end of the harness 85 to pass through, and the through groove 317b of the second support wall 317 allows the harness 85 to pass through. formed.

When mounting the board 84 to the second support wall 317 , the connector 87 is mounted on the board 84 and the other end of the harness 85 is connected to the board 84 . After the substrate 84 is attached to the second support wall 317, the connector 86 on one end side of the harness 85 is passed through the holding hole 317a from the outer surface 317A side of the second support wall 317 to the inner surface 317B side of the second support wall 317, and the conveying frame 31 is mounted. infiltrate the interior of

Further, the harness 85 is passed from the outer side surface 317A side of the second support wall 317 to the inner side surface 317B side through the through groove 317b and pulled into the conveying frame 31 . After pulling the harness 85 into the transport frame 31, the harness 85 is positioned at the lower end of the through groove 317b.

As described above, in the sheet conveying unit 30, when the harness 85 extending from the substrate 84 attached to the outer surface 317A of the second support wall 317 is routed inside the conveying frame 31, the connector 86 is conveyed through the holding hole 317a. The harness 85 is configured to enter the interior of the frame 31 and be drawn into the interior of the transport frame 31 through the through groove 317b.

As a result, there is no need to separately provide a hole for allowing the connector 86 of the harness 85 to pass between the outside and the inside of the transport frame 31 , and the strength of the transport frame 31 can be maintained. In addition, the harness 85 connected to the connector 86 that has passed through the conveying frame 31 through the holding hole 317a can be routed through the through groove 317b into the conveying frame 31, thereby reducing the space for routing the harness 85 and miniaturizing the device. It becomes possible to plan

The harness 85 drawn into the conveying frame 31 through the through groove 317b extends in the direction of the axis X from the right end to the left end of the conveying frame 31 below the registration roller 35a, and is connected to the substrate 84. It is possible to route the harness 85 that is connected to the transport frame 31 in a space-saving manner.

Further, the conveying frame 31 has a protrusion 317c protruding into the through-groove 317b in the middle of the extending direction of the through-groove 317b. The protrusion 317c is positioned closer to the holding hole 317a than the harness 85 positioned at the lower end of the through groove 317b, and restricts the harness 85 passing through the through groove 317b from moving toward the holding hole 317a. As a result, the harness 85 passing through the through groove 317b can be held at the lower end of the through groove 317b at a desired position.

Reference Signs List 1 image forming apparatus 5 image forming section 26 front frame 26a front surface 30 sheet conveying unit 31 conveying frame 35a registration roller 36 guide member 37 ground sheet metal 37d contact section 37e second fixing section 37f regulation section 38 gear cover 27b conduction section 82 ground spring 82b first end 82c second end 84 substrate 85 harness 86 connector 311 first support wall 313 spring support 314 slit 314a upper edge 315 contact surface 316 regulation surface 317a holding hole 317b through groove 317c projection 351 rotating shaft 381 Rib C Center S Seat X Axis W1 Width W3 Gap

Claims (10)

a conveying roller having a rotating shaft made of metal and conveying the sheet;
a frame member that supports the rotating shaft;
a ground spring having a first end connected to the rotating shaft and a circular second end;
A grounding sheet metal that is grounded and that contacts the second end of the grounding spring by being inserted into the frame member through a slit formed in the frame member, the grounding sheet metal being detachable from the frame member. Earth sheet metal,
with
the frame member has a spring support portion with which the second end of the ground spring abuts when the ground sheet metal is removed from the frame member;
The second end of the ground spring has a first position abutting against the spring support portion when the ground sheet metal is removed from the frame member, and a first position where the ground sheet metal is attached to the frame member. movable to a second position in contact with the ground sheet metal;
The edge of the second end of the slit on the side of the second position in the moving direction between the first position and the second position is the moving direction of the second end at the first position. a sheet conveying device positioned closer to the first position than the center of the sheet. the frame member has a support wall arranged adjacent to the ground spring in the axial direction of the rotation shaft and supporting the rotation shaft;
2. The sheet conveying apparatus according to claim 1, further comprising a rib member located on the opposite side of the support wall with the ground spring therebetween in the axial direction and projecting toward the ground spring. 3. The sheet conveying device according to claim 2, wherein said rib member protrudes in said axial direction to a position overlapping said ground metal plate attached to said frame member when viewed in a direction orthogonal to said axial direction. The spring support portion of the frame member protrudes from the support wall toward the rib member in the axial direction to a position having a gap between itself and the rib member,
4. The sheet conveying device according to claim 2, wherein said gap is smaller than the width of said second end of said ground spring in said axial direction. a metal guide member for guiding the sheet to the conveying roller upstream of the conveying roller in the sheet conveying direction;
The sheet conveying device according to any one of claims 1 to 4, wherein the guide member and the ground metal plate are electrically connected. With a grounded metal frame,
Earth sheet metal
a first portion in contact with the contact surface of the frame member;
a second part fixed to the fixing surface of the metal frame;
a third part connecting the first part and the second part and bent with respect to the first part and the second part;
the frame member has a regulating surface that intersects with the contact surface and the fixed surface;
The sheet conveying device according to any one of claims 1 to 5, wherein the third portion abuts on the regulation surface. Equipped with a harness with a connector connected to one end,
The frame member is
a holding hole that holds the rotating shaft and is formed to have a size through which the connector can pass;
The sheet conveying device according to any one of claims 1 to 6, further comprising a through groove extending radially outward from the holding hole and through which the harness can pass. 8. The frame member has a projection that protrudes into the through-groove at an intermediate portion in the extending direction of the through-groove and restricts the harness passing through the through-groove from moving toward the holding hole. The sheet conveying device according to . The ground sheet metal is arranged at one end of the frame member in the axial direction,
a substrate disposed at an end opposite to the ground sheet metal across the conveying roller in the axial direction;
9. The sheet conveying apparatus according to claim 7, wherein the harness extends in the axial direction below the conveying roller and has the other end connected to the substrate. a sheet conveying device according to any one of claims 1 to 9;
an image forming unit that forms an image on a sheet conveyed by the sheet conveying device;
An image forming apparatus comprising:

Images