JP3602499B2 - Image forming device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fixing device and an image forming apparatus, and more particularly, to a mechanism for moving a peeling member for peeling a sheet from a roller in a rotation axis direction of the roller.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying machine or a printer, a sheet is inserted into a nip portion of a fixing roller including a heat roller and a pressure roller, and an unfixed image (unfixed toner image) is heated on the sheet. A fixing device for pressure fixing is provided, and a claw-shaped peeling member is arranged to contact the heat roller and the pressure roller with a predetermined contact pressure in order to prevent winding of the sheet. If the peeling member is in contact with the heat roller or the pressure roller at the same position for a long time, there is a problem that the roller surface is damaged due to abrasion. When the toner adheres, there is a problem that the abrasion is promoted and the surface of the roller becomes severely damaged, and excess toner adheres to the paper to cause the paper to become dirty or to cause paper jam. Therefore, a fixing device has been proposed in which a mechanism for linearly moving (thrust moving) the peeling member in contact with the roller surface in the rotation axis direction of the roller is provided, and the time for which the peeling member contacts the roller surface at the same position is shortened. ing.
[0003]
[Problems to be solved by the invention]
However, in the conventional fixing device as described above, a driving source such as a solenoid is separately required in addition to a driving source for the fixing roller in order to move the peeling member in the thrust direction. is there. Also, a drive mechanism using a one-way bearing to move the peeling member in the thrust direction by using the driving force of the drive source of the fixing roller has been proposed, but the configuration of the drive mechanism becomes complicated, and in this case, However, there is a problem that the manufacturing cost is increased.
[0004]
The present invention has been made in order to solve the above-described problems, it is possible to linearly move the peeling member in the rotation axis direction of the roller with a simple configuration without the need for a unique drive source, An object of the present invention is to provide a fixing device and an image forming apparatus with reduced manufacturing costs.
[0005]
[Means for Solving the Problems]
[0006]
In addition, the invention according to claim 1, a peeling member that peels the paper from a roller that comes into contact with the paper,
A guide member that supports the peeling member and guides a sheet conveying direction in a sheet conveying path on the downstream side of the roller,
A side plate that supports the guide member so as to be able to linearly reciprocate in the rotation axis direction of the roller,
The axis of rotation of the rollerIn the directionAround the extended rotation axisThe side plate is pivotally supported so as to rotate, and the peeling member and the guide member come into contact with and separate from the paper transport path.A support member rotatable in the direction;
The rotational driving force of the driving source of the roller or the transport roller disposed downstream of the roller is converted into a linear driving force in the rotation axis direction of the roller, and with this linear driving force,Press the guide memberDriving means for linearly reciprocating the peeling member in the rotation axis direction of the roller;
EquippedPictureAn image forming apparatus.
[0007]
According to this configuration, it is not necessary to provide a new driving source for the reciprocating movement of the peeling member by utilizing the rotational driving force of the driving source of the roller or the transport roller disposed downstream of the roller. Further, by rotating the guide member with respect to the support member, the peeling member can be separated from the roller, and the guide member can be separated from the paper conveyance path in a state of being bent with respect to the support member, The peeling member, the guide member, and the support member can be separated from the roller or the sheet transport path without requiring a large space.
[0008]
The invention according to a second aspect is the image forming apparatus according to the first aspect, wherein the driving unit includes the roller.ofA worm that is rotated by the rotational driving force of the drive source of the transport roller disposed on the downstream side, a worm wheel that meshes with the worm, and a cam that is provided on the rotation shaft of the worm wheel and rotates together with the worm wheel. Have
The cam isWhen the guide member is at a position where the peeling member comes into contact with the roller, a pressing force is applied to the guide member in this state.While rotating, the guide memberAccording to the rotation of this cam,The roller is configured to reciprocate linearly in the direction of the rotation axis of the roller.ToThings.
[0009]
According to this configuration,the aboverollerofSince a large reduction ratio can be obtained when transmitting the rotational driving force of the drive source of the transport roller disposed downstream from the worm to the worm wheel,the aboveThe rotational driving force of a driving source such as a roller can be converted into a driving force of a magnitude suitable for the reciprocating movement of the peeling member. Further, unlike the case where a solenoid is provided to linearly reciprocate the peeling member, a thrust bearing is not required, and the configuration can be simplified.
[0010]
The invention described in claim 3 is:3. The image forming apparatus according to claim 1, wherein the guide member is fixed to the image forming apparatus main body side, and the guide member moves in the direction of contact and separation of the sheet conveyance path by rotation of the support member. 4. Regulating means for regulating the posture of the side plate and the guide member,
A pin that is provided on each of the side plates provided on both sides of the guide member and that engages with the restricting means;
When the guide member moves in the direction of contact and separation with the paper transport path by the rotation of the support member, the pin engages with the regulating means, and the posture of the side plate and the guide member near the roller surface. Is regulatedThings.
[0011]
In addition, the invention described in claim 4 is an embodiment of the present invention.1Or claim3The image forming apparatus according to any one of the above, wherein the guide member is rotated by a predetermined amount with respect to the support member when the guide member moves in a direction of contacting and separating from a sheet conveyance path by rotation of the support member. At that point,A contact portion formed at an end of the guide member on the support member side is engaged with an inner wall of the support member, and a posture of the guide member with respect to the support member is regulated.Things.
[0012]
According to this configuration, when the support member rotates,AbutmentRegulates the posture of the guide member with respect to the support member, so that the posture of the guide member when the guide member moves toward and away from the paper transport path can be appropriately adjusted appropriately.
[0013]
In addition, the invention described in claim 5 is an embodiment of the present invention.4An image forming apparatus, wherein the rotation of the support member,When the guide member is separated from the paper transport path, the guide memberTo the contact part ofHolding means for holding the guide member in a position substantially perpendicular to the paper transport direction is provided;,
A hole is provided in the support member at a position corresponding to the holding means, and the holding means is engaged with the contact part of the guide member through the hole.Things.
[0014]
According to this configuration, when the guide member is separated from the paper transport path, the guide member is held in a posture substantially orthogonal to the paper transport direction.the aboveLowLa,The open area of the paper transport path is widened, and a wide work area for paper jam clearance and the like can be secured.
[0015]
In addition, the invention described in claim 6 is an embodiment of the present invention.1Or claim5The image forming apparatus according to any one of the above, wherein the guide member is provided with a covering unit that covers the peeling member so as to be able to be taken in and out,
The covering unit is elastically urged in a direction to cover the peeling member, and in a state where the guide member is in the paper transport path.The protrusion formed on the covering means is engaged with a cover for covering the roller, whereby the covering means is pressed against the guide member against the elastic force, and the peeling member is exposed. To contact the roller,In a state where the guide member is separated from the paper transport path, the peeling member is covered by elastic force.Configuration andIs what is being done.
[0016]
According to this configuration, when the guide member is separated from the paper conveyance path, the peeling member is covered with the covering means, so that the safety at the time of work such as paper jam processing is improved, and breakage of the peeling member is also prevented. .
[0017]
The invention according to claim 7 isContractRequestAny one of items 1 to 65.The image forming apparatus according to claim 1, wherein the peeling member performs the reciprocating movement by a movement amount equal to or larger than a width of the peeling member in a rotation axis direction of the roller.UThings.
[0018]
According to this configuration, the time required for the peeling member to come into contact with the surface of the roller at the same position can be reliably shortened. Adhesion of the toner that has entered into the release member is also reduced.
[0019]
The invention described in claim 8 isContractRequest1Or claim75. The image forming apparatus according to claim 1, wherein the peeling member performs the reciprocating movement within a range of a width of the sheet conveyed to the roller.Is Umono.
[0020]
According to this configuration, the peeling member isthe aboveEven if it moves in the direction of the rotation axis of the roller, it does not come off the paper.the aboveThere is no hindrance to the operation of peeling the paper from the rollers.
[0021]
The invention according to claim 9 isContractThe image forming apparatus according to any one of claims 1 to 8, wherein one cycle of the reciprocating movement of the peeling member is obtained by multiplying a peripheral speed of the roller by one cycle time of the reciprocating movement of the peeling member. The rotation distance L of the roller is 0.5 m ≦ L ≦ 20 mThings.
[0022]
According to this configuration,the aboveAvoid abrupt movement of the peeling member with respect to the rotation of the roller.the aboveIt is possible to prevent the roller surface from being damaged, and also maintain the effect of removing toner adhering to the roller contact surface of the peeling member and preventing the paper edge from entering between the peeling member and the roller surface. be able to.
[0023]
Further, the invention described in claim 10 is1Or claim9The image forming apparatus according to any one of the above, wherein the support memberToIs locked to the apparatus housing when the guide member is separated from the paper transport path and is in a posture substantially orthogonal to the paper transport direction.The locking part is formedThings.
[0024]
According to this configuration, since the support member is locked to the apparatus housing, it is possible to prevent the support member from falling in the direction of closing the work area during work such as paper jam processing. improves.
[0025]
Further, the invention described in claim 11 is the same as the invention.1Or claim10In the image forming apparatus according to any one of the above, the supporting member may be configured such that a locking member for locking the guide member on a sheet conveyance path rotates around a same fulcrum as the guide member. The guide member is held or released by the rotation of the locking member.
[0026]
According to this configuration, the posture of the guide member when the guide member moves in the contact / separation direction with respect to the paper conveyance path can be held with a simple configuration.
[0027]
Further, the invention described in claim 12 is1Or claim115. The image forming apparatus according to claim 1, wherein the roller is a fixing roller that is rotated to fix an unfixed image on a sheet.
[0028]
Further, the invention according to claim 13 is:Claim 12An image forming apparatus according toWhen the guide member is separated from the paper conveyance path by the rotation of the support member, the upper part of the downstream area of the fixing roller is opened.Things.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a fixing device and an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a schematic configuration of an image forming apparatus according to the present invention. As shown in FIG. 1, in the copying machine (an example of an image forming apparatus) 1, a photosensitive drum 4 rotating in a direction A in the drawing is uniformly charged by a charging unit 3 and read by a document reading unit 5. An electrostatic latent image is formed on the photosensitive drum 4 by a laser beam from a laser scanning unit (not shown) based on the original document image, and toner is formed on the electrostatic latent image by the developing unit 7 to form a toner image. You.
[0030]
The paper is conveyed from the paper feeding mechanism 9 via the paper conveyance path 10 toward the photoconductor drum 4 on which the toner image is formed as described above, and the toner image on the surface of the photoconductor drum 4 is transferred to the paper. . Then, the sheet on which the toner image has been transferred is separated from the photosensitive drum 4 and is conveyed to a fixing device 12 having a heat roller 121 and a pressure roller 122, where the toner image is fixed. The sheet that has passed through the nip portion between the heat roller 121 and the pressure roller 122 is directly discharged to the discharge unit 14 by the discharge roller pair 13, or is transported by the branch member 16 provided at the branch point of the paper transport path 15 in the transport direction of the sheet. Is switched to be conveyed to the switchback unit 17, and after the sheet is turned over, the toner image is transferred again to the back side at the transfer position of the photosensitive drum 4, and both sides are copied and discharged to the discharge unit 14.
[0031]
Reference numeral 18 denotes a cleaning unit that removes residual toner and the like on the photosensitive drum 4. Reference numeral 19 denotes a document transport unit that transports a document to the document reading unit 5 to read a document image. The paper feed mechanism 9 is detachably attached to the copying machine main body 2 and includes paper feed cassettes 91, 92, 93, and 94 for storing paper, and a paper feed tray 95 provided above the paper feed cassettes. These are connected to the developing unit 7 and the photosensitive drum 4 by a paper transport path 10.
[0032]
Although not shown in FIG. 1, the fixing device 12 is provided with a peeling member that comes into contact with the surface of the heat roller 121 and peels off the paper from the roller. And linearly move in the rotation axis direction of the heat roller 121 (a characteristic part of the present invention). The pressure roller 122 is also provided with a peeling member.
[0033]
Next, the fixing device 12 will be described. FIG. 2 is a side view showing a schematic configuration of the fixing device. The fixing device 12 has a fixing roller pair including a heat roller 121 having a built-in heater and a pressure roller 122 pressed against the heat roller 121, and is separated from the heat roller 121 in order to prevent the paper from being wound. The member 123 is provided on the pressure roller 122, and the peeling member 123 is provided on the pressure roller 122. The heat roller 121 and the pressure roller 122 rotate in the directions indicated by arrows in FIG. 2, and the paper on which the toner image has been transferred by the photosensitive drum 4 (see FIG. 1) is passed through the nip portion of both rollers. The unfixed toner image is heated and pressed on the sheet.
[0034]
A guide member 125 is provided downstream of the fixing roller pair 120 to guide the sheet in the transport direction of the sheet passing through the fixing roller pair. The lower portion of the guide member 125 forms a part of the paper transport path 15, and the peeling member 123 on the heat roller 121 side is rotatably attached. The peeling member 123 is set so that the leading end thereof abuts on the heat roller 121 with a predetermined contact pressure by a pull spring 126 attached to the guide member 125. Further, a contact portion 127 that contacts an eccentric cam described later is provided on a side surface portion of the guide member 125. The guide member 125 is configured to move linearly (thrust motion) in the rotation axis direction of the heat roller 121 when the contact portion 127 is pressed by rotation of an eccentric cam described later (details will be described later). ).
[0035]
Next, a drive mechanism for linearly and thrust-moving the peeling member 123 and the guide member 125 in the rotation axis direction of the heat roller 121 will be described. 3A is a plan view showing a peeling member and a guide member and the drive mechanism, FIG. 3B is a side view showing a gear mechanism constituting the drive mechanism, and FIG. 3C is an eccentric cam and a guide member of the drive mechanism. FIG.
[0036]
A thrust drive mechanism 150 for thrustly moving the peeling member 123 and the guide member 125 includes a worm 151a provided around a rotation shaft 151b of the fixing roller rotary knob 151, and a helical gear 152 as a worm wheel meshing with the worm 151a. The eccentric cam 152b is provided coaxially with the rotation shaft 152a of the helical gear 152. The guide member 125 is provided with a protrusion 128 on a side surface opposite to the side surface on which the contact portion 127 is provided, and is provided in a hole (not shown) formed in the housing 129 of the fixing device 12. It is slidably supported. A push spring 130 is attached to the protruding portion 128 to urge the guide member 125 in the direction of the eccentric cam 152b (to the right in FIG. 3A).
[0037]
The fixing roller rotating knob 151 has a gear 151c provided on the rotating shaft 151b meshed with the rotation driving gear 121a of the heat roller 121. When the fixing roller rotating knob 151 is rotated, the heat roller 121 is manually rotated. It is configured to be able to. On the other hand, when the heat roller 121 is rotated by a drive source (not shown) that meshes with the rotary drive gear 121a, the fixing roller rotary knob 151 rotates by meshing the rotary drive gear 121a and the gear 151c.
[0038]
As shown in FIG. 3B, the helical gear 152 is disposed so as to mesh with the upper part of the worm 151a. The eccentric cam 152b provided on the rotation shaft 152a of the helical gear 152 is arranged such that a side portion thereof is in contact with the contact portion 127 of the guide member 125, and the eccentric cam 152b has a It rotates while rubbing.
[0039]
In this configuration, when the heat roller 121 rotates at the time of transferring a toner image, the fixing roller rotation knob 151 and the worm 151a also rotate, and the helical gear 152 meshing with the worm 151a also rotates. When the helical gear 152 rotates, the eccentric cam 152b provided on the same rotating shaft 152a also rotates, and the side portion of the eccentric cam 152b presses the contact portion 127 of the guide member 125. Thus, the guide member 125 and the peeling member 123 reciprocate in the directions of the arrows (the rotation axis direction of the heat roller 121) in FIGS. 3A and 3C according to the shape of the eccentric cam 152b. That is, the rotational driving force of the driving source of the heat roller 121 is converted into a linear driving force in the rotation axis direction of the heat roller 121, and the peeling member 123 is moved by the linear driving force. . Therefore, when the heat roller 121 rotates, the peeling member 123 moves in a thrust direction with respect to the heat roller 121, and the time during which the peeling member 123 contacts the surface of the heat roller 121 at the same position is shortened.
[0040]
In such a configuration, when the peeling member 123 is caused to perform a thrust motion by the driving force from the driving source of the heat roller 121, a large reduction ratio is generated when the driving force of the driving source of the heating roller 121 is transmitted from the worm 151a to the helical gear 152. Obtainable. In addition, by changing the gear ratio between the worm 151a and the helical gear 152 or the gear ratio between the rotary drive gear 121a and the gear 151c, the reciprocating movement cycle of the peeling member 123 and the rotation distance of the heat roller 121 (the peripheral speed of the heat roller × The relationship of one cycle time of the reciprocating movement of the peeling member can be easily changed.
[0041]
Next, the thrust motion of the peeling member 123 will be described. FIG. 4 is a diagram illustrating the amount of movement of the peeling member 123, and FIG. 5 is a diagram illustrating a movable region of the peeling member 123 with respect to the sheet. As shown in FIG. 4, it is preferable that the amount of movement of the peeling member 123 due to the thrust motion is at least equal to or greater than the width of the peeling member 123 in the rotation axis direction of the heat roller 121. Therefore, the eccentric cam 152b has a shape in which the rotating shaft 152a is eccentric so that the peeling member 123 moves in a thrust manner by a moving amount larger than the width. Then, in relation to the width of the paper P conveyed to the fixing device 12, the peeling members 123 at both ends supported by the guide member 125 reciprocate within the width of the paper P as shown in FIG. The positioning of the guide member 125 and the peeling member 123 with respect to the heat roller 121 is set so as to move.
[0042]
As described above, the toner that has entered between the peeling member 123 and the heat roller 121 can be accurately removed by thrust-moving the peeling member 123 by a moving amount equal to or greater than the width of the peeling member 123. Contact time at the same position with the surface can be shortened. Further, by setting the movable region of the peeling member 123 within the range of the width of the paper P, the peeling member 123 can be thrust-moved without impairing the original function of peeling the paper P wound around the heat roller 121. .
[0043]
The relationship between the rotation distance of the heat roller 121 and the reciprocating cycle of the thrust movement of the peeling member 123 is determined by the rotation distance of the heat roller 121 per one cycle of the reciprocating movement of the peeling member 123 (the peripheral speed of the heat roller 121 × the peeling member). It is preferable that the length L of one cycle of the reciprocating movement of L) is 0.5 m ≦ L ≦ 20 m. According to this, abrupt movement of the peeling member 123 with respect to the rotation of the heat roller 121 can be avoided, and damage to the surface of the heat roller 121 due to contact with the peeling member 123 can be prevented. The effect of reducing toner adhesion to the contact surface can also be maintained.
[0044]
Furthermore, if the rotation distance L of the heat roller 121 per one cycle of the reciprocating movement by the peeling member 123 is set to 1 m ≦ L ≦ 10 m, the surface of the heat roller 121 is more reliably damaged by the contact with the peeling member 123. Is prevented, and the effect of reducing toner adhesion to the roller contact surface of the peeling member 123 can be maintained. For example, the width of the peeling member 123 in the rotation axis direction of the heat roller 121 is about 2 mm, the thrust moving amount of the peeling member 123 is about 2.4 mm, the peripheral speed of the heat roller 121 is about 290 mm / s, and the reciprocating movement of the peeling member 123 is performed. If the cycle is about 13 sec, the rotation distance L of the heat roller 121 per one cycle of the thrust movement of the peeling member 123 is about 3.8 m, the wear of the heat roller surface is extremely small, and the contact surface of the peeling member 123 is small. Alternatively, it is possible to maintain a state in which the toner is hardly attached to the surface of the heat roller 121 on the surface of the toner.
[0045]
The present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible. For example, the present invention may be configured as follows.
[0046]
(1) In the above embodiment, the helical gear 152 is used as the worm wheel that meshes with the worm 151a. However, a simple gear may be used for the worm wheel instead of the helical gear.
[0047]
(2) In the above-described embodiment, the eccentric cam 152b is slid and rotated by the guide member 125 in order to move the guide member 125 in the thrust direction. Good.
[0048]
(3) In the above embodiment, the peeling member 123 and the guide member 125 are configured to move in a thrust manner by using the rotational driving force of the driving source of the heat roller 121, but the driving source and the fixing of the pressure roller 122 are fixed. The thrust movement may be performed using the rotational driving force of the driving source of the transport roller disposed downstream of the roller.
[0049]
(4) In the above-described embodiment, the thrust movement of the peeling member 123 is preferably performed in a region equal to or larger than the width of the peeling member 123 in the rotation axis direction of the heat roller 121. It may be performed in the following areas.
[0050]
(5) The reciprocating movement cycle of the peeling member 123, the movable region of the peeling member 123, and the like are not limited to the numerical values shown in the above embodiment, and can be appropriately changed.
[0051]
Next, a mechanism for releasing the peeling member 123 from the heat roller 121 and releasing the guide member 125 from the paper transport path downstream of the fixing device 12 to open the paper transport path will be described with reference to FIGS. Will be explained. 6 to 9 show the opening / closing mechanism without the thrust drive mechanism 150.
[0052]
FIG. 6 is a side view illustrating a schematic configuration of an opening / closing mechanism that detaches the peeling member 123 from the heat roller 121 and opens a sheet conveyance path on the downstream side of the fixing device 12. This opening / closing mechanism can include the above-described thrust mechanism 150. However, in order to clarify the configuration and operation of the opening / closing mechanism, first, the opening / closing mechanism is provided with the thrust mechanism 150 using FIGS. 6 to 9. No open / close mechanism will be described. A lower portion of the guide member 125 on the downstream side of the fixing roller pair forms a part of the sheet transport path 15, and a peeling member 123 on the heat roller 121 side is rotatably attached to a side portion. A covering member 167 for covering and protecting the peeling member 123 is provided above the guide member 125. The covering member 167 is slidably attached to the guide portion 168 above the guide member 125, and is urged by a pressing spring 169 in a direction away from the guide member 125 (to the right in FIG. 6). A protrusion 167 a is formed on the top of the covering member 167, and the protrusion 167 a is locked to the fixing roller cover 170, so that the covering member 167 is pressed against the guide member 125 against the urging force of the pressing spring 169. Is done. As a result, the peeling member 123 is exposed and comes into contact with the heat roller 121.
[0053]
In the housing of the fixing device 12, a support member 172 is rotatably provided around a rotation support shaft 171 as a rotation axis, and the guide member 125 is attached to the support member 172. The support member 172 and the guide member 125 constitute an opening / closing mechanism 160. When the support member 172 rotates counterclockwise in FIG. 6, the guide member 125 also rotates in the same direction together with the support member 172. By the rotation of the support member 172, the guide member 125 is separated from the paper transport path 15, and the paper transport path 15 is opened.
[0054]
The guide member 125 is rotatably attached to the support member 172 about a rotation support shaft 173 as a center of rotation, and a contact portion 125 a formed on the guide member 125 engages with an inner wall 172 a of the support member 172. It is configured to be rotatable until it stops. Further, a pin 125b is formed on a side portion of the guide member 125, and is engaged with a guide rail 175 provided in a housing of the fixing device 12. By the engagement between the pin 125b and the guide rail 175, the attitude of the guide member 125 with respect to the support member 172 when the opening and closing mechanism 160 is opened and closed is regulated. By devising the guide direction of the pin 125b by the guide rail 175, the posture of the guide member 125 when the opening and closing mechanism 160 is opened and closed can be adjusted to a desired angle.
[0055]
The support member 172 is provided with a locking member 177 for holding the support member 172 and the guide member 125 on the paper transport path 15. The locking member 177 is provided on the support member 172 so as to rotate on the same rotation support shaft 173 as the guide member 125, and is engaged with a pin 180 provided on the housing of the fixing device 12. Is formed. The locking member 177 is rotated about the rotation supporting shaft 173 to switch whether or not to engage the pin 180, thereby switching the holding or release of the guide member 125 on the paper transport path 15. .
[0056]
Further, when the guide member 125 is separated from the paper conveyance path 15, the housing (housing of the fixing device) 181 located on the upper left side of the support member 172 is engaged with the contact portion 125 a of the guide member 125 so as to engage with the guide member 125. A holding unit 182 that holds the sheet 125 in a posture substantially orthogonal to the sheet conveyance direction is provided. A hole (not shown) is provided at a position corresponding to the holding portion 182 of the support member 172, and the holding portion 182 is engaged with the contact portion 125a of the guide member 125 through the hole. ing.
[0057]
Next, the operation of the guide member 125 and the support member 172 when the opening and closing mechanism 160 is opened and closed will be described. 7 and 8 are views showing the operating state of the guide member 125 and the support member 172 during the opening / closing operation, and FIG. 9 is a view showing the state where the guide member 125 and the support member 172 are locked to the housing 181.
[0058]
When opening the paper transport path 15 for paper jam processing or the like, first, the fixing device 12 is pulled out from the body (image forming apparatus housing) 2 of the copying machine 1 toward the user. Then, the locking member 177 is rotated clockwise in FIG. 7 to release the locking between the locking member 177 and the pin 180. As a result, the support member 172 can be rotated upward, and the guide member 125 can be separated from the paper transport path 15. When the support member 172 is rotated upward, the guide member 125 is bent with respect to the support member 172 by the guide of the pin 125 b by the guide rail 175, and is gradually separated from the paper transport path 15 in this state. To go.
[0059]
Then, as shown in FIG. 8, when the guide member 125 moves further upward and the pin 125b separates from the guide rail 175, the guide member 125 is released from the movement regulation by the guide rail 175. Then, the guide member 125 rotates clockwise in FIG. 8 until the contact portion 125a of the guide member 125 is locked to the inner wall 172a of the support member 172. When the contact portion 125a and the inner wall 172a are locked, the posture of the guide member 125 with respect to the support member 172 is fixed. At this time, the covering member 167 of the guide member 125 is released from the engagement of the protrusion 167a with the fixing roller cover 170, and covers the peeling member 123 by the urging of the pressing spring 169 (the direction of arrow B in FIG. 8). Slide to. Then, the peeling member 123 is also released from contact with the heat roller 121, and is rotated in the counterclockwise direction in FIG.
[0060]
When the support member 172 is further rotated in the counterclockwise direction, the support member 172 comes into contact with the housing 181, as shown in FIG. At this time, the holding portion 182 engages with the contact portion 125 a of the guide member 125 through the hole of the support member 172 described above, and holds the guide member 125 in a posture substantially orthogonal to the paper transport path 15. When the guide member 125 is in this position, the distal end portion 125c of the guide member 125 also comes into contact with the upper part of the housing 181, whereby the position of the guide member 125 is maintained.
[0061]
At this time, the protrusion 177a of the locking member 177 is locked to the side end 181a of the housing 181, and the support member 172 is moved by the locking of the protrusion 177a and the side end 181a. It is fixed to the housing 181 so as not to rotate (to fall down) toward the transport path 15. Accordingly, the support member 172 can be fixed to the housing 181 with the guide member 125 being in a state of being substantially perpendicular to the paper transport path 15, so that a wide work area for paper jam processing and the like can be secured. Besides, the safety at the time of work is improved by preventing the support member 172 from falling down. Further, as described above, since the peeling member 123 is rotated by the pulling spring 126 and the covering member 167 is moved in a direction to cover the peeling member 123 by the pressing spring 169, the tip of the peeling member 123 is covered with the covering member 167. To further improve safety during operation and prevent breakage of the peeling member 123.
[0062]
When closing the opening / closing mechanism 160 (when closing the paper transport path 15), the locking member 177 is released from locking with the side end portion 181a of the housing 181, and the support member 172 is rotated clockwise in FIG. Let's move. Then, the contact portion 125a of the guide member 125 is separated from the holding portion 182, and the pin 125b of the guide member 125 is engaged with the guide rail 175 again, whereby the posture of the guide member 125 is regulated, and the guide member 125 is gradually supported. The state becomes parallel to the member 172, and the peeling member 123 comes into contact with the heat roller 121. When the lower part of the guide member 125 moves to the upper part of the paper transport path 15, the locking member 177 is locked to the pin 180, and the support member 172 and the guide member 125 are fixed on the paper transport path 15. As a result, the sheet transport path 15 is closed, and the fixing device 12 becomes operable.
[0063]
In the embodiment to which the opening / closing mechanism 160 is applied, an example in which the present invention is applied to the fixing roller portion of the fixing device 12 is shown. However, for example, the following configuration may be adopted.
[0064]
(1) The opening / closing mechanism 160 may be applied to a peeling member provided in the photosensitive drum 4, the document conveying mechanism, the sheet post-processing mechanism, and the like.
[0065]
(2) In an image forming apparatus provided with a photoreceptor belt, a transfer belt, a transport belt, and the like, the opening / closing mechanism 160 can be applied to a peeling member that peels a sheet from each of these belts.
[0066]
(3) The opening / closing mechanism 160 can be applied to a peeling member that peels a sheet from a transfer drum and a transfer belt in a color image forming apparatus.
[0067]
Further, the opening / closing mechanism 160 is not limited to the configuration of the guide member 125, the support member 172, and the locking member 177 described in the above embodiment, and may be configured as follows, for example.
[0068]
(4) In the above embodiment, the locking member 177 of the support member 172 is configured to rotate on the same rotation support shaft 173 as the guide member 125. May be configured to rotate around a separate rotation support shaft.
[0069]
(5) The fixing of the support member 172 to the housing 181 when the sheet transport path 15 is opened is realized by locking the protrusion 177a of the locking member 177 to the side end 181a of the housing 181. However, the present invention is not limited to this configuration, and a member that locks to the housing 181 may be provided separately from the locking member 177 to lock the support member 172 to the housing 181.
[0070]
(6) In the above embodiment, the paper transport path 15 on the downstream side of the fixing roller is opened by rotating the guide member 125, the support member 172, and the locking member 177. A paper transport roller may be provided, and the paper transport path may be opened.
[0071]
FIG. 10 is a side view showing a schematic configuration of an opening / closing mechanism 160 provided with a thrust drive mechanism 150. FIG. 11 is a side view schematically showing a thrust moving operation of the guide member 125. FIG. FIG. 6B is a diagram illustrating a state where the guide member 125 is not pressed by the cam 152b, and FIG. 7B is a diagram illustrating a state where the guide member 125 is pressed by the eccentric cam 152b.
[0072]
The opening / closing mechanism 160 provided with the thrust drive mechanism 150 is supported by a rotation support shaft 173 such that the side plate 165 can rotate with respect to the support member 172. A guide member 125 for supporting the peeling member 123 is attached to the side plate 165 so as to be slidable in the rotation axis direction of the side plate 165 (the depth direction in FIG. 10). The worm 151 a and the helical gear 152 meshing with the worm 151 a are arranged beside the guide member 125 and the side plate 165 in a state where the opening / closing mechanism 160 is closed and the peeling member 123 is in contact with the heat roller 121.
[0073]
Support shafts 125d and 125e are provided on the side of the guide member 125. The support shafts 125d and 125e are slidably supported by the side plates 165 by being fitted into holes formed in the side plates 165 provided on both sides of the guide member 125. The support shaft 125d on the eccentric cam 152b side has a guide member 125 side portion.Side plate 165A tension spring 130a is provided so as to be interposed between the guide member 125 and the support shaft 125e opposite to the support shaft 125d.Side plate 165A pressing spring 130b is provided so as to be interposed between the two. The guide member 125 is urged toward the eccentric cam 152b by the pull spring 130a and the push spring 130b.
[0074]
On the side of the guide member 125 on the side of the eccentric cam 152b, a contact portion 127 is provided at a position separated from the side plate 165 (above the side plate 165 in FIG. 11). When the eccentric cam 152b rotates and presses the contact portion 127 in the horizontal direction via the pressing member 190 that can move in the horizontal and horizontal directions, the guide member 125 pulls the tension spring 130a in accordance with the rotation of the eccentric cam 152b. The guide member 125 and the peeling member 123 perform thrust movement linearly reciprocating in the direction of the rotation axis against the force and the urging force of the pressing spring 130b. Therefore, the side plate 165 is not pressed by the eccentric cam 152b and does not move in the thrust direction, and only the guide member 125 moves in the thrust direction.
[0075]
The pressing member 190 includes a pressing shaft 190a supported by the housing 129 so as to be movable in the horizontal and horizontal directions, and a pressing plate 190b attached to one end of the pressing shaft 190a and moving in the horizontal and horizontal directions together with the pressing shaft 190a. Become. The housing 129 is provided with a support portion 129a that supports the pressing shaft 190a so as to be movable in the horizontal direction. The end of the pressing shaft 190a to which the pressing plate 190b is not attached is in contact with the side of the eccentric cam 152b. The pressing shaft 190a is fitted into a hole formed in the support portion 129a and the housing 129, and penetrates through the hole from the eccentric cam 152b side to the guide member 125 side. When the opening / closing mechanism 160 is closed, the pressing plate 190b contacts the contact portion 127 of the guide member 125, and presses the guide member 125 in the same direction as the pressing shaft 190a moves in the horizontal and horizontal directions.
[0076]
Pins 165 b that regulate the posture of the guide member 125 by engaging with the guide rail 175 when the opening and closing mechanism 160 is opened and closed are provided on each side plate 165 on both sides of the guide member 125. The side plate 165 of the side plate 165 on the side of the eccentric cam 152b is provided on the side surface facing the eccentric cam 152b, and the side plate 165 of the side plate 165 on the opposite side is provided on the side surface facing the housing 129. The pin 165b of the side plate 165 on the side of the eccentric cam 152b is set so as not to interfere with the pressing plate 190b even when the pressing plate 190b moves toward the guide member 125 due to the rotation of the eccentric cam 152b. A guide rail 175 is also provided on the housing 129 facing the pin 165b of the side plate 165 on the opposite side, and the pin 165b is configured to engage with the guide rail 175 when the opening and closing mechanism 160 is opened and closed. .
[0077]
The thrust movement of the guide member 125 accompanying the rotation of the eccentric cam 152b will be described. As shown in FIG. 11A, the eccentric cam 152b presses the pressing shaft 190a when the distance l from the rotation shaft 152a of the eccentric cam 152b to the end of the pressing shaft 190a is the shortest. Instead, the pressing plate 190b is set to be in a state of abutting on the inner surface of the housing 129. In this state, the pressing plate 190b does not press the guide member 125 (the contact portion 127).
[0078]
As the eccentric cam 152b rotates from this state and the distance 1 from the rotating shaft 152a to the end of the pressing shaft 190a gradually increases, as shown in FIG. It is detached from the housing 129. The guide member 125 is pressed by the movement of the pressing plate 190b, and slides horizontally (to the right in FIGS. 11A and 11B).
[0079]
When the guide member 125 is moved upward to open the paper transport path 15 (when the opening / closing mechanism 160 is opened), the pin 165b of the side plate 165 moves upward along the guide rail 175. The contact portion 127 of the guide member 125 moves upward while sliding on the pressing plate 190b. Further, the pin 165b is set so as not to interfere with the pressing plate 190b even when the pin 165b approaches the pressing plate 190b. Therefore, the upward movement of the guide member 125 and the side plate 165 does not hinder the presence of the pressing plate 190b.
[0080]
When the guide member 125 and the side plate 165 gradually approach the paper transport path 15 from above when the opening / closing mechanism 160 is closed from the open state, the pressing plate 190b is moved to the housing 129 shown in FIG. The worm 151a and the helical gear 152 may be automatically rotated so that the pressing plate 190b is in contact with the housing 129 so that the worm 151a and the helical gear 152 are automatically rotated so that the pressing plate 190b is in contact with the housing 129. So that it becomes). Accordingly, even if the contact portion 127 is released from being pressed by the pressing plate 190b and is being moved to the eccentric cam 152b side by the pulling force of the pulling spring 130a and the urging force of the pressing spring 130b, the contacting portion 127 is kept in contact. The portion 127 is not hindered from entering the guide rail 175 by the pressing plate 190b, and is smoothly engaged with the guide rail 175.
[0081]
Since the fixing device 12 has the opening / closing mechanism 160 as described above, (1) the peeling member 123 can be reciprocated in the rotation axis direction of the heat roller 121 without providing a new driving source. In addition to the effect that the opening and closing mechanism 160 can be performed, (2) the effect that the peeling member 123 and the like can be retracted from the heat roller 121 without requiring a large space, and (3) the paper transport path 15 is opened. By doing so, it is possible to obtain an effect that the operability during jam processing is excellent.
[0082]
The opening / closing mechanism 160 including the thrust drive mechanism 150 is not limited to the configuration of the above-described embodiment, and various modifications are possible. For example, the opening / closing mechanism 160 may be configured as follows.
[0083]
(1) In the above embodiment, the pressing of the guide member 125 in the horizontal direction with the rotation of the eccentric cam 152b is performed via the pressing member 190. Instead of this configuration, the eccentric cam 152b and the guide member are used. A configuration in which the housing 129 interposed between the guide members 125 is cut out so that the side portion of the eccentric cam 152b directly presses the contact portion 127 of the guide member 125 may be adopted.
[0084]
(2) Although the pressing member 190 is composed of both the pressing shaft 190a and the pressing plate 190b, the configuration of the pressing member 190 is not limited to this configuration, and the eccentric cam 152b and the contact portion Any configuration may be used as long as the guide member 125 can be pressed in accordance with the rotation of the eccentric cam 152b by being interposed between the guide members 125 (or the guide member 125).
[0085]
【The invention's effect】
According to the present invention as described above,By using the rotational driving force of the driving source of the roller or the transport roller disposed downstream of the roller, it is not necessary to provide a new driving source for the reciprocating movement of the peeling member. Further, by rotating the guide member with respect to the support member, the peeling member can be separated from the roller, and the guide member can be separated from the paper conveyance path in a state of being bent with respect to the support member, The peeling member, the guide member, and the support member can be separated from the roller or the sheet transport path without requiring a large space.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a schematic configuration of an image forming apparatus according to the present invention.
FIG. 2 is a side view illustrating a schematic configuration of a fixing device according to the present invention.
3A is a plan view showing a peeling member, a guide member, and a driving mechanism for thrust-moving them, FIG. 3B is a side view showing a gear mechanism constituting the driving mechanism, and FIG. It is a side view which shows an eccentric cam and a guide member.
FIG. 4 is a view showing a movement amount of a peeling member.
FIG. 5 is a diagram illustrating a movable region of a peeling member with respect to a sheet.
FIG. 6 is a side view illustrating a schematic configuration of an opening / closing mechanism that detaches a peeling member from a heat roller and opens a sheet conveyance path downstream of the fixing device.
FIG. 7 is a diagram illustrating an example of an operation state of a guide member and a support member during an opening / closing operation of an opening / closing mechanism.
FIG. 8 is a diagram illustrating an example of an operation state of a guide member and a support member during an opening / closing operation of an opening / closing mechanism.
FIG. 9 is a view showing the opening / closing mechanism in a state where the guide member and the support member are locked in the housing.
FIG. 10 is a side view showing a schematic configuration of an opening / closing mechanism having a thrust drive mechanism.
11A and 11B are side views schematically showing a thrust moving operation of the guide member, wherein FIG. 11A shows a state where the guide member is not pressed by the eccentric cam, and FIG. 11B shows a state where the guide member is pressed by the eccentric cam. FIG.
[Explanation of symbols]
1 Copier (an example of an image forming apparatus)
2 Copier body
7 Developing section
12 Fixing device
15 Paper transport path
120 fixing roller pair
121 heat roller
122 pressure roller
123 peeling member
125 Guide member
125a contact part
125b pin
125c tip
125d, 125e Support shaft
126 spring
127 Contact part
129 Housing
129a Support
130 spring
130a Extension spring
130b Press spring
150 Thrust drive mechanism
151a warm
152 Hasvagear
152a Rotation axis
152b Eccentric cam
160 opening and closing mechanism
165 side plate
165b pin
167 Covering member
167a Projection
168 Guide part
169 spring
171 Rotation support shaft
172 Supporting member
172a inner wall
173 Rotation support shaft
175 guide rail
177 Locking member
177a Projection
180 pins
181 housing
181a side end
182 Holder
190 pressing member
190a Pressing shaft
190b Press plate

Claims (13)

A peeling member that peels the paper from a roller that is in contact with the paper,
A guide member that supports the peeling member and guides a sheet conveying direction in a sheet conveying path on the downstream side of the roller,
A side plate that supports the guide member so as to be able to linearly reciprocate in the rotation axis direction of the roller,
With pivotally supporting said side plates so as to pivot about pivot axis extending in the rotational axis Direction of the rollers, the release member and the guide member is rotatable in a direction toward or away from the sheet conveying path support Components,
The rotational driving force of the driving source of the roller or the transport roller disposed downstream of the roller is converted into a linear driving force in the rotation axis direction of the roller, and the linear driving force converts the guide member. pressing to images forming apparatus and a drive means for linearly reciprocating the peeling member in the rotation axis direction of the roller. The driving unit is provided on a worm rotated by a rotational driving force of a driving source of a transport roller disposed downstream of the roller , a worm wheel meshed with the worm, and a rotating shaft of the worm wheel, A cam rotating with the worm wheel,
When the guide member is at a position where the peeling member comes into contact with the roller, the cam rotates while applying a pressing force to the guide member in this state. in response to the rotation, the image forming apparatus according to 請 Motomeko 1 that is a linearly reciprocates constituting the rotation axis of the roller. Regulating means fixed to the image forming apparatus main body side, and regulating the posture of the side plate and the guide member when the guide member moves in the direction of contact and separation of the sheet conveying path by the rotation of the support member;
  A pin is provided on each of the side plates provided on both sides of the guide member, and a pin is provided for engaging with the restricting means.
  When the guide member moves in the direction of contact and separation with the paper transport path by the rotation of the support member, the pin engages with the restricting means, and the posture of the side plate and the guide member near the roller surface. The image forming apparatus according to claim 1, wherein the image forming apparatus is regulated. When the guide member is moved in the direction of contact and separation with the sheet transport path by the rotation of the support member, the guide member has an end on the support member side at a point in time when the guide member rotates by a predetermined amount relative to the support member. abutment portion formed in part is the engaged with the inner wall of the supporting member, the image forming apparatus according to any one of claims 1 to 3 orientation relative to the support member is restricted. Holding said by the rotation of the support member, said when the guide member is spaced from the sheet conveying path, to retain in abutment and engagement locks are substantially perpendicular to the guide member in the sheet conveying direction and orientation of the guide member Means are provided ,
The image forming apparatus according to claim 4 , wherein a hole is provided at a position of the support member corresponding to the holding unit, and the holding unit is engaged with the contact portion of the guide member through the hole. apparatus. The guide member is provided with a covering unit that covers the peeling member so as to be able to be taken in and out,
The covering means is elastically urged in a direction to cover the peeling member, and in a state where the guide member is in the paper transport path, a projection formed on the covering means is engaged with a cover for covering the roller. By stopping, the covering means is pressed against the guide member against the elastic bias, the peeling member is exposed and abuts on the roller, and the guide member is separated from the paper transport path. in the image forming apparatus according to any one of claims 1 to 5 has a structure in which the release member is covered by a resilient biasing. The peeling member, an image forming apparatus according to any one of the peeling member width or more mobile amount with the line power sale billed to claim 1 or the reciprocating movement claims in the rotation axis direction of the roller 6. The peeling member, an image forming apparatus according to any one of the reciprocating line cormorants the 請 Motomeko 1 to claim 7 in a range of the width of the sheet conveyed on the rollers. Obtained by multiplying the reciprocal movement one cycle time of the release member to the peripheral speed of the rollers, the rotation distance L of the rollers reciprocate one cycle per by the peeling member, Ru 0.5 m ≦ L ≦ 20 m Der 請 An image forming apparatus according to claim 1. The support member, the guide member is apart from the paper transport direction to claims 1 to that securing portion secured to the apparatus housing is formed when a substantially orthogonal orientation from the sheet conveying path Item 10. The image forming apparatus according to any one of Items 9 . The support member is provided with a locking member for locking the guide member on a paper transport path so as to rotate about the same shaft fulcrum as the guide member. the image forming apparatus according to any one of claims 1 to 10 held or released to the sheet conveying path of the member is switched. The roller, an image forming apparatus according to any one of claims 1 to 11 which is a fixing roller which is rotated to fix the unfixed image on the sheet. The image forming apparatus according to claim 12, wherein when the guide member is separated from the sheet conveyance path by the rotation of the support member, an upper part of a downstream area of the fixing roller is opened .

Images