JPH0827568B2 - Transfer paper separating device in image forming apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer paper separating device for forcibly separating the transfer paper after transfer from the surface of the photoconductor in an image forming apparatus such as a copying machine. .

[Conventional technology]

In a general separating device, a separating claw is provided in contact with the surface of the photosensitive drum, and the transfer paper after transfer is separated from the drum surface by the separating claw.

Also, to prevent the separated transfer paper from pushing the separation claw toward the photoconductor drum side and damaging the drum surface or rolling it up to the downstream side, immediately guide the separated transfer paper toward the conveyance path to the fixing unit. A guide member is provided near the separation claw.

[Problems to be Solved by the Invention]

In this case, the separation claws are axially fixed by being provided with position restriction members such as E-rings on both sides in a state of being fitted in the mounting shaft in the axial direction. Further, the guide member is fixed with screws or the like in order to keep the angle constant.

For this reason, the number of parts for mounting both of them is large, the cost is high, and the mounting work is troublesome.

Further, when replacing the separation claw according to the friction of the tip, etc., (a) the separation claw must be removed from the mounting shaft and then detached from the mounting shaft.

(B) When attaching and detaching the separation claws, a laborious work of attaching and detaching the position regulating member such as the E-ring is required.

(C) In addition, the guide members that are close to each other get in the way at this time.

For this reason, the efficiency of replacement work of the separation claw is poor.

Therefore, the present invention provides a transfer paper separating device in an image forming apparatus, which has a simple mounting structure for the separating claw and the guide member, has a small number of parts, and facilitates replacement work of the separating claw.

[Means for solving the problem]

 The invention of claim 1 has the following configuration.

(I) A separation claw for separating the transfer paper after the transfer from the surface of the photoconductor and a guide member for guiding the transfer paper separated by the separation claw toward the transport path are arranged in the axial direction with respect to the common mounting shaft. Be installed side by side.

(II) Each of the separating claw and the guide member has a fitting portion having a C-shaped cross section with a notch in a part in the circumferential direction, and the fitting portion is detachably mounted on the mounting shaft in the radial direction. To be done.

(III) Of these, the guide member mounting portion of the pressing shaft is formed in a D-shaped cross section having a flat surface, and the fitting portion of the guide member is axially and circumferentially fixed to the guide member mounting portion. Be fitted with.

(IV) The separation claws should be attached with one side in the axial direction being in contact with this guide member and being regulated in one side in the axial direction.

In addition, the invention of claim 2 is the structure of claim 1,
The separation claw is rotatable with respect to the mounting shaft between an operating position where the tip contacts the surface of the photoconductor and a non-acting position where the tip is separated from the surface of the photoconductor, and the separation claw naturally moves toward the acting position. The guide member is mounted in a rotatable state, and on the other hand, a guide member rotating mechanism for rotating the guide member between two fixed positions around the axis of the mounting shaft is provided. A claw operating portion is provided to prevent rotation to the operating position at one of the two positions and allow it at the other position.

[Action]

According to this structure, first, the guide member also serves as one position regulating member for fixing the separation claw in the axial direction (the position regulating member on one side is unnecessary). Secondly, the guide member is automatically fixed in the axial direction and the circumferential direction in a state of being fitted to the mounting shaft (the axial and circumferential position regulating members of the guide member are not required).

Therefore, the structure for mounting the separation claw and the guide member on the mounting shaft is simple, and the number of parts for mounting the far smaller than in the prior art.

In addition, since the separation claw and the guide member can be attached and detached in the radial direction with respect to the mounting shaft, it is not necessary to remove the mounting shaft when replacing the separation claw, and the attachment / detachment operation of both of them with respect to the mounting shaft is easy. The separation claw replacement work becomes easy.

Further, according to the structure of claim 2, in addition to the above-mentioned basic operation and effect, the guide member also serves as a switching means for switching the separation claw between the operating position and the non-operating position, so that the number of parts is further reduced. Can be made.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 is a photosensitive drum, 2 is a transfer charging device provided facing the photosensitive drum 1, and 3 is a separation charging device.

The transfer paper (generally referred to as a transferable sheet material) is guided by a transfer guide plate 4 and fed to the transfer charging device 2 as shown by an arrow in FIG. 1, and the toner image on the drum 1 is transferred thereto. After that, it is separated from the drum surface by the separation charging device 3 and is sent to the conveyor belt 5 toward the fixing portion.

At this time, the transfer sheet may not be smoothly separated from the surface of the drum and may wind up on the downstream cleaning device 6 side. Therefore, the separation device 7 is provided on the downstream side of the separation charging device 3.

The separating device 7 includes a sharpened separation claw 8 for forcibly separating the transfer paper from the drum surface, and a guide member 9 for directing the transfer paper separated by the separation claw 8 to the conveyor belt 5 immediately. It has.

The separation claw 8 and the guide member 9 are mounted side by side in the axial direction on a common mounting shaft 10. This mounting structure will be described in detail with reference to FIGS.

On the mounting shaft 10, a guide member mounting portion 11 having a flat cut surface 11a on the lower surface side and having a D-shaped cross section is formed. Further, an E-ring 12 as a position regulating member is provided at a position separated from one end of the guide member mounting portion 11 by the width dimension of the separation claw 8.
Is installed.

On the other hand, the separation claw 8 has a pointed claw portion 13 and a lever portion 14, and a fitting portion 15 fitted into the mounting shaft 10 between them.
Is provided.

The fitting portion 15 is formed in a C-shaped cross section with a cutout 15a on the rear surface side (the side opposite to the photosensitive drum 1 side). As shown by the arrow in FIG. 2, the fitting portion 15 has a cutout 15a. The separation claw 8 is attached to the mounting shaft 10 by being fitted into the guide member mounting portion 11 of the mounting shaft 10 from the front side through and then being slid to the E ring 12 side.

Here, the fitting portion 15 is formed such that the inner diameter dimension thereof is slightly larger than the diameter dimension of the mounting shaft 10 so that the fitting portion 15 can freely rotate with respect to the mounting shaft 10.

Further, the center of gravity of the separating claw 8 is set on the lever portion 14 side, and in the natural state, the center of gravity tends to rise due to the setting of the center of gravity.

The guide member 9 is formed by providing a transfer paper guide portion 17 on the lower surface of a flat substrate 16 and an arcuate projecting piece 18 on the intermediate portion of the upper surface. A corresponding fitting portion 19 is formed.

The cross-sectional size of the fitting portion 19 is set to be slightly smaller than that of the guide member mounting portion 11, and after the separation claw is mounted, the fitting portion 19 is elastically fitted to the guide member mounting portion 11 so that the guide The member 9 is attached to the guide member attaching portion 11.

In addition, in order to facilitate this fitting operation, the tip end portion 18a of the protruding piece 18 forming the fitting portion 19 is bent outward.

In this mounting state, the guide member 9 has a guide member mounting portion.
By the fitting action of 11 and the fitting portion 19, the position is automatically fixed in the axial direction and the circumferential direction.

Also, by attaching this guide member 9,
The separation claw 8 is sandwiched between the E ring 12 and the guide member 9 and fixed in position in the axial direction.

Further, the guide member 9 is integrally provided with a claw pushing portion 20 projecting upward in an L shape on the side surface of the rear end portion of the substrate 16,
In the installed state, as shown in Figs. 3 and 4, the claw pushing part 20
Comes into contact with the lever portion 14 of the separation claw 8 from below.

On the other hand, a shaft rotating mechanism as shown in FIG. 3 is provided at one end or both ends of the mounting shaft 10.

This shaft rotation mechanism includes a solenoid 21 as a drive source,
It is composed of a link transmission mechanism 22 that transmits the pulling force of the solenoid 21 to the mounting shaft 10 as a rotational force in a fixed direction, and a return spring 23.

 Next, the operation of this separating device will be described.

The solenoid 21 is energized only when the transfer paper separating action is required. Specifically, for example, when the supply of the transfer paper to the photoconductor drum 1 is started, the sensor detects the rotation of the registration roller or the movement of the transfer paper toward the transfer charging unit 2, and the solenoid 21 is energized. To be done.

In the state where this solenoid 21 does not operate (de-energize),
As shown in FIG. 4, the claw pushing portion 20 of the guide member 9 comes into contact with the lever portion 14 of the separation claw 8 from below to prevent the separation claw 8 from moving upward. Therefore, the separation claw 8 is
13 is separated from the surface of the photosensitive drum 1.

In this way, in order to protect the drum surface, the separation claw 8 is separated from the drum surface when unnecessary transfer paper separating action is not performed, so that the drum surface is not unnecessarily pressed.

Next, when the solenoid 21 is energized to operate, the mounting shaft 10 rotates by a fixed angle, the guide member 9 rotates in the upward direction as shown in FIG. Away from the lever portion 14 of.

Therefore, the separation claw 8 is released from the rotation restriction and automatically rotates in the forward rising direction. As a result, the tip of the claw portion 13 comes into contact with the surface of the photosensitive drum 1, and in this state, the original transfer paper separating / guide function is performed.

On the other hand, when replacing the separation claw 8 due to wear of the tip or the like, contrary to the above-described mounting, first, the guide member 9 is radially extracted from the guide member mounting portion 11 of the mounting shaft 10 and then removed. Slide the separation claw 8 sideways to guide member mounting portion 11
From the same way. Further, a new separation claw 8 may be attached by the same procedure as the first attachment.

In this way, the replacement work of the separation pawl 8 can be easily performed only by the radial attachment / detachment operation of the guide member 9 with respect to the mounting shaft 10 and the radial attachment / detachment and axial slide operation of the separation pawl 8.

By the way, in the above-mentioned embodiment, the separation claw 8 is operated by the claw pushing portion 20 of the guide member 9 as the switching means for switching the separation claw 8 between the state in which the separation claw 8 is in contact with the drum surface and the state in which the separation claw 8 is separated from the drum surface. Although the means, that is, the guide member 9 is also used as the switching means, in the invention of claim 1, regardless of the guide member 9, the separation claw 8 is directly connected to the contact position and the separation position by a solenoid or the like. You may make it rotate between them.

Further, such a separating claw rotating means is not provided, and the separating claw 8 is
May be always in contact with the drum surface.

〔The invention's effect〕

As described above, according to the present invention, (A) the separation claw and the guide member are provided with a fitting portion having a C-shaped cross section, and the fitting portion allows both to be attached to and detached from the mounting shaft in the radial direction. (B) The guide member mounting portion of the mounting shaft is formed in a D-shaped cross section, and the guide member is mounted in this portion in a positionally fixed position in the axial direction and the circumferential direction. Since the position is regulated to one side in the axial direction, the structure for mounting the separation claw and the guide member on the mounting shaft becomes simple, and the number of parts for mounting can be far smaller than in the conventional case. For this reason, the cost is remarkably low.

There is no need to remove the mounting shaft when replacing the separation claw,
Also, since the attachment / detachment operation of the both with respect to the mounting shaft is simple, the work of exchanging the separation claws becomes very easy.

Further, according to the second aspect of the invention, when the separation claw is switched between the operating position and the non-operating position, the guide member also serves as the switching means, so that the number of parts can be further reduced. it can.

[Brief description of drawings]

FIG. 1 is a front view showing a separation device and its peripheral equipment according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the same device, FIG. 3 is a perspective view of the same assembled state, FIGS. 4 and 5. The figure is an enlarged front view for explaining the operation of the apparatus. 1 ... Photosensitive drum, 7 ... Separation device, 8 ... Separation claw of separation device, 9 ... Same guide member, 10 ... Same mounting shaft, 11 ...
… Mounting part of guide member for mounting shaft, 11a …… Cut surface (flat surface) of the mounting part, 15 …… Separating claw fitting part, 19 …… Guide member fitting part.

Claims (2)

[Claims] 1. A transfer paper separating device in an image forming apparatus comprising the following structure. (I) A separation claw for separating the transfer paper after the transfer from the surface of the photoconductor and a guide member for guiding the transfer paper separated by the separation claw toward the transport path are arranged in the axial direction with respect to the common mounting shaft. Be installed side by side. (II) Each of the separating claw and the guide member has a fitting portion having a C-shaped cross section with a notch in a part in the circumferential direction, and the fitting portion is detachably mounted on the mounting shaft in the radial direction. To be done. (III) Of these, the guide member mounting portion of the mounting shaft is formed into a D-shaped cross section having a flat surface, and the fitting portion of the guide member is axially and circumferentially fixed to the guide member mounting portion. Be fitted with. (IV) The separation claws should be attached with one side in the axial direction being in contact with this guide member and being regulated in one side in the axial direction. 2. A transfer paper separating device in an image forming apparatus according to claim 1, wherein the separating claw has an operating position where the tip contacts the surface of the photoconductor with respect to the mounting shaft, and the tip is separated from the surface of the photoconductor. The guide member is mounted so as to be rotatable between the non-acting position and the natural position toward the actuating position, while the guide member is rotated between two fixed positions around the axis of the mounting shaft. A pawl operating portion is provided with a guide member rotating mechanism for moving the guide member, and the guide member prevents the separation pawl from rotating to the operating position at one of the two positions and allows the other at the other position. A transfer paper separating device in an image forming apparatus, comprising: