JP2016080931A - Driving mechanism, fixing unit, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an abnormal noise caused by backlash between a rotary member and a driving member during drive.SOLUTION: A driving mechanism includes: a rotary member that rotates in the circumferential direction of a cylinder; a driving member that is in contact with an end of the cylinder to be driven in the circumferential direction of the cylinder; a recess that is provided at an end of the cylinder; a projection that is provided on the inner surface of the driving member, projects in the direction of the peripheral surface comprising the outer peripheral surface of the rotary member through the recess, and transmits a driving force to the rotary member; and an inclined surface that is provided on the inner surface of the driving member and projects obliquely from the outside to the inside of the outer peripheral surface of the rotary member as approaching the projection from the front side in the driving direction of the driving member.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a driving structure, a fixing device, and an image forming apparatus.

  Conventionally, a fixing device that thermally fixes an unfixed toner image on a sheet to the sheet and an image forming apparatus including such a fixing unit are known.

  For example, Patent Document 1 discloses a fixing unit 19 having a heating roller 52 in which a roller driving gear 65 is attached to one end of a metal base tube 64. The metal pipe 64 is formed with a recess 71 cut out in an approximately U-shape from the end edge inward in the axial direction, and the roller drive gear 65 is engaged with the recess 71 on the inner peripheral surface. A convex portion 75 is formed. Then, the concave portion 71 and the convex portion 75 are aligned so that the concave portion 71 and the convex portion 75 are opposed to each other, and one end portion of the metal base tube 64 is inserted into the inner peripheral surface of the roller driving gear 65.

JP 2006-39433 A (paragraphs [0051] to [0054])

  Since the end of the rotating member is inserted into and engaged with the driving member, there is a gap between the outer peripheral surface of the rotating member and the inner peripheral surface of the driving member, and the rotating member and the driving member rotate during driving. A contact sound between the member and the driving member is generated.

  An object of the present invention is to reduce contact noise caused by rattling between a rotating member and a driving member during driving.

The drive structure according to claim 1 is:
A rotating member having a cylindrical shape and rotating in a circumferential direction of the cylinder;
A driving member that contacts the end of the cylinder and is driven in the circumferential direction of the cylinder;
A recess provided at an end of the cylinder;
A protrusion provided on an inner surface of the driving member, protruding in a direction of a peripheral surface not from an outer peripheral surface of the rotating member through the recess, and transmitting a driving force to the rotating member;
A slope that is provided on the inner surface of the drive member and protrudes obliquely from the outside to the inside of the outer peripheral surface of the rotating member as it approaches the protrusion from the front in the drive direction of the drive member;
It is provided with.

The fixing device according to claim 2 is:
A rotating member having a cylindrical shape and rotating in a circumferential direction of the cylinder;
A pressure member for fixing the toner image on the surface of the recording medium by sandwiching and pressing the recording medium holding the unfixed toner image on the surface between the rotation member; and
A heat source for heating the recording medium sandwiched between the rotating member and the pressure member;
A driving member that contacts the end of the cylinder and is driven in the circumferential direction of the cylinder;
A recess provided at an end of the cylinder;
A protrusion provided on an inner surface of the driving member, protruding in a direction of a peripheral surface not from an outer peripheral surface of the rotating member through the concave portion, and transmitting a driving force to the rotating member;
A slope that is provided on the inner surface of the drive member and protrudes obliquely from the outside to the inside of the outer peripheral surface of the rotating member as it approaches the protrusion from the front in the drive direction of the drive member;
It is provided with.

The fixing device according to claim 3 is:
A plurality of the recesses are provided at intervals in the circumferential direction of the cylinder,
A plurality of sets of the protruding portion and the slope are provided corresponding to each of the plurality of concave portions.

An image forming apparatus according to claim 4 comprises:
A rotating member having a cylindrical shape and rotating in a circumferential direction of the cylinder;
A pressure member for fixing the toner image on the surface of the recording medium by sandwiching and pressing the recording medium holding the unfixed toner image on the surface between the rotation member; and
A heat source for heating the recording medium sandwiched between the rotating member and the pressure member;
A driving member that contacts the end of the cylinder and is driven in the circumferential direction of the cylinder;
A recess provided at an end of the cylinder;
A protrusion provided on an inner surface of the driving member, protruding in a direction of a peripheral surface not from an outer peripheral surface of the rotating member through the concave portion, and transmitting a driving force to the rotating member;
A slope that is provided on the inner surface of the drive member and protrudes obliquely from the outside to the inside of the outer peripheral surface of the rotating member as it approaches the protrusion from the front in the drive direction of the drive member;
And an image forming device that forms the unfixed toner image on the surface of the recording medium;
It is provided with.

  According to the drive structure according to claim 1, the fixing device according to claim 2, and the image forming apparatus according to claim 4, contact noise caused by rattling between the rotation member and the drive member during driving is reduced. be able to.

  According to the fixing device of the third aspect, the deviation between the center of the rotating member and the center of the rotational drive is small as compared with the case where the set of the projecting body and the inclined surface is one set.

1 is a schematic configuration diagram of a printer which is an embodiment of an image forming apparatus of the present invention. FIG. 2 is a cross-sectional view of a fixing device and a discharge device in the printer shown in FIG. It is a perspective view showing a heating roll. It is a figure showing the structure of the keyway of a heating roll. It is a front view showing the structure of a drive gear. It is a perspective view showing the structure of a drive gear. It is a figure which shows the state at the time of the drive start in the operation | movement with which a drive gear and a heating roll are fixed. It is a figure which shows the state at the time of the fixation start in the operation | movement with which a drive gear and a heating roll are fixed. It is a figure which shows the state at the time of completion of fixation in the operation | movement with which a drive gear and a heating roll are fixed.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a printer which is an embodiment of the image forming apparatus of the present invention.

  The printer 10 shown in FIG. 1 is a monochrome printer, and the printer 10 incorporates an embodiment of a fixing device of the present invention.

  An image signal representing an image created outside the printer 10 is input to the printer 10 via a signal cable (not shown). The printer 10 includes a control unit 11 that controls the movement of each component in the printer 10, and an image signal is input to the control unit 11. In the printer 10, an image is formed based on the image signal under the control of the control unit 11.

  A paper tray 21 is provided below the printer 10, and the paper P is stored in the paper tray 21 in a stacked state. The paper tray 21 is configured to be freely drawn out for replenishing the paper P.

  The paper P in the paper tray 21 is sent to the standby roll 24 by the pickup roll 22 and the separating roll 23. The paper P that has reached the standby roll 24 is further transported after the transport timing is adjusted.

  The printer 10 includes a photoreceptor 12 that rotates in a direction indicated by an arrow A above a standby roll 24. A charger 13, an exposure device 14, a developing device 15, a transfer device 16, and a photoconductor cleaner 17 are disposed around the photoconductor 12.

  The charger 13 charges the surface of the photoconductor 12, and the exposure device 14 exposes the surface of the photoconductor 12 to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 15 to form a toner image.

  Here, the standby roll 24 sends out the paper P so that the toner image on the photoconductor 12 reaches that position in accordance with the timing when it reaches the position facing the transfer device 16. The toner image on the photoconductor 12 is transferred to the fed paper P under the action of the transfer device 16.

  The toner remaining on the photoconductor 12 after the transfer of the toner image is removed from the photoconductor 12 by the photoconductor cleaner 17.

  A combination of the photoconductor 12, the charger 13, the exposure device 14, the developing device 15, and the transfer device 16 corresponds to an example of the image forming device referred to in the present invention.

The sheet P that has received the transfer of the toner image further proceeds in the direction of arrow B, and is heated and pressed by the fixing device 100 to fix the toner image on the sheet P. As a result, an image composed of a fixed toner image is formed on the paper P. The fixing device 100 corresponds to an embodiment of the fixing device of the present invention.

  The paper P that has passed through the fixing device 100 proceeds in the direction of arrow C toward the discharge device 200, and is further sent in the direction of arrow D by the discharge device 200 to be discharged onto the paper discharge tray 18.

  FIG. 2 is a view showing a cross section of the fixing device and the discharging device in the printer 10 shown in FIG.

  The fixing device 100 includes a heating roll 101 and a pressure roll 102. The heating roll 101 is obtained by coating the outer peripheral surface of a metal cylinder with a release material, and a heat source 103 is disposed inside the heating roll 101. The pressure roll 102 is also cylindrical, and the circumferential surface of the pressure roll 102 is pressed against the circumferential surface of the heating roll 101. The sheet that has advanced in the direction of arrow B and has reached the fixing device 100 enters the contact portion between the pressure roll 102 and the heating roll 101. The sheet is sandwiched between the heating roll 101 and the pressure roll 102 at the contact portion. At this time, the sheet is in a state where the surface on which the toner image is formed faces the heating roll 101 side.

  The heating roll 101 and the pressure roll 102 rotate in the direction of arrow F while being in contact with each other. For this reason, the paper that has entered the contact portion passes through the contact portion by the rotation of the heating roll 101 and the pressure roll 102 and proceeds in the direction of arrow C toward the discharger 200. Then, during the passage, the toner image is fixed on the sheet by being heated by the heat source 103 inside the heating roll 101 and being pressurized by the pressure roll 102, and an image composed of the fixed toner image is formed. The sheet is fed from the discharger 200 in the direction of arrow D by the discharge roll 203 and discharged onto the discharge table 18.

  The heating roll 101 corresponds to an example of a rotating member according to the present invention, the pressure roll 102 corresponds to an example of a pressing member according to the present invention, and the heat source 103 corresponds to an example of a heat source according to the present invention.

  Here, details of the heating roll 101 will be described.

  FIG. 3 is a perspective view showing a heating roll.

  A driving gear 104 that rotates the heating roll 101 is fitted to one end of the heating roll 101. The drive gear 104 has teeth (not shown) arranged around it, and receives a driving force from the motor via the teeth. The drive gear 104 is provided with a key 105 protruding inward, and this key 105 is fitted in a key groove 106 provided at the end of the heating roll 101. The driving force received by the drive gear 104 from the motor is transmitted to the heating roll 101 through the key 105, and the heating roll 101 receives the driving force in the key groove 106. The heating roll 101 rotates in the direction of arrow F in the figure by its driving force.

  The drive gear 104 corresponds to an example of a drive member according to the present invention, and the key 105 corresponds to an example of a protruding portion according to the present invention. The key groove 106 corresponds to an example of a recess according to the present invention. Moreover, the structure part provided with the heating roll 101 and the drive gear 104 is equivalent to one Embodiment of the drive structure of this invention.

  FIG. 4 is a diagram illustrating the structure of the keyway of the heating roll.

  FIG. 4 shows only the end portion of the heating roll 101. The heating roll 101 is provided with two key grooves 106, one for each half circumference of the heating roll 101. Each key groove 106 extends from the end side of the heating roll 101 to the center side, and is a so-called opening groove that penetrates the inside and outside of the heating roll 101. The drive gear 104 is fitted on the end of the heating roll 101 so as to be covered. In other words, the end of the heating roll 101 is inserted into the drive gear 104.

  FIG. 5 is a front view showing the structure of the drive gear, and FIG. 6 is a perspective view showing the structure of the drive gear.

  Two keys 105 are provided on the inner peripheral surface of the drive gear 104, one for each half of the drive gear 104. Each key 105 protrudes from the inner peripheral wall toward the center of the drive gear 104. The drive gear 104 rotates in the direction of arrow F in the figure, and a slope 107 is provided in front of the rotation direction with respect to each key 105. The slope 107 is inclined so that the side close to the key 105 protrudes to the center side of the drive gear 104. The end of the inclined surface 107 closer to the key 105 reaches the inner side of the outer peripheral surface of the heating roll 101 inserted into the drive gear 104 (that is, the center side of the drive gear 104). Of the both ends of the slope 107, the end far from the key 105 is positioned outside the outer peripheral surface of the heating roll 101.

  As described above, since the drive gear 104 is fitted into the end of the heating roll 101, the inner peripheral surface of the drive gear 104 is larger in diameter than the outer peripheral surface of the heating roll 101, and the inner peripheral surface of the driving gear 104 and the heating roll 101. However, as will be described below, the driving gear 104 and the heating roll 101 are strongly fixed to each other during driving by the inclined surface 107 of the driving gear 104 as described below.

  FIGS. 7 to 9 are diagrams for explaining the principle of operation in which the drive gear and the heating roll are fixed. FIG. 7 shows the state at the start of driving, and FIG. 8 shows the state at the start of fixing. FIG. 9 shows a state when the fixing is completed. 7 to 9 are diagrams conceptually showing the principle of fixing the drive gear and the heating roll, so the dimensions are not accurate.

  The drive gear 104 meshes with the drive gear 110, and when the drive source gear 110 rotates in the direction of arrow G in the figure, the drive gear 104 rotates in the direction of arrow F in the figure. On the other hand, since the heating roll 101 is subjected to a resistance that restricts rotation due to contact with the pressure roll 102 described above, the heating roll 101 is relatively moved by the rotation of the driving gear 104 and the key 107 and the key. Move in a direction approaching 105.

  As the heating roll 101 approaches the slope 107, the edge of the key groove 106 of the heating roll 101 moves on the slope 107 so as to bite into the slope 107. As a result, the outer peripheral surface of the heating roll 101 is pressed against the inner peripheral surface of the drive gear 104 via the inclined surface 107. When the edge of the key groove 106 reaches the key 105, the edge of the key groove 106 bites into the inclined surface 107, and as a result, the heating roll 101 and the drive gear 104 are firmly fixed to each other. Therefore, although there is a gap between the inner peripheral surface of the drive gear 104 and the outer peripheral surface of the heating roll 101, rattling during driving of the heating roll 101 and the driving gear 104 is prevented, and the contact sound Is also prevented.

  Further, in the example shown here, a set of a key 105 and a slope 107 is provided at a plurality of locations on the inner peripheral surface of the drive gear 104. Since biting occurs, there is less misalignment between the centers of the drive gear 104 and the heating roll 101 than in the case where the set of the key 105 and the slope 107 is provided only in one place.

  In the above embodiment, a monochrome printer has been described as an example of the image forming apparatus. However, the image forming apparatus of the present invention may be a color printer, or may be a facsimile, a copier, or a multifunction machine. Also good.

  In the above embodiment, as an example of the image forming device according to the present invention, an image forming device of a type that transfers a toner image formed on a photoreceptor onto a recording medium has been described. The image forming device may directly form a toner image on a recording medium.

  In the above-described embodiment, an example in which a toner image is formed by electrophotography that undergoes charging, exposure, and development is shown. However, the image forming apparatus according to the present invention directly forms a toner image without forming a latent image. It may be drawn.

  When the electrophotographic method is adopted, the charger may be a contact type charger using a charging roll or the like, or may be a non-contact type charger using a discharge wire or the like. . Further, the exposure device may use laser light as a light source, or may use LED or the like as a light source. Further, the developing device may use a so-called two-component developer in which toner and carrier are mixed, or may use a developer containing toner as a main component. The transfer unit may be a direct type transfer unit that directly transfers a toner image from the photosensitive member onto the paper, or indirectly the toner from the photosensitive member to the paper via an intermediate transfer member or the like. An indirect transfer device that transfers an image may be used.

  Moreover, in the said embodiment, although the thing provided with two recessed parts of the rotating member said to this invention was shown and demonstrated, the rotating member said to this invention may have one recessed part, or a recessed part. It may have three or more.

DESCRIPTION OF SYMBOLS 10 Printer 12 Photoconductor 13 Charger 14 Exposure device 15 Developing device 16 Transfer device 100 Fixing device 101 Heating roll 102 Pressure roll 103 Heat source 104 Driving gear 105 Key 106 Key groove 107 Slope 110 Driving source gear

Claims (4)

A rotating member having a cylindrical shape and rotating in a circumferential direction of the cylinder;
A driving member that contacts an end of the cylinder and is driven in a circumferential direction of the cylinder;
A recess provided at an end of the cylinder;
A protrusion provided on the inner surface of the driving member, protruding in the direction of the peripheral surface not from the outer peripheral surface of the rotating member through the recess, and transmitting a driving force to the rotating member;
A slope that is provided on the inner surface of the drive member and protrudes obliquely from the outside to the inside of the outer peripheral surface of the rotating member as it approaches the protrusion from the front in the drive direction of the drive member;
A drive structure characterized by comprising: A rotating member having a cylindrical shape and rotating in a circumferential direction of the cylinder;
A pressure member for fixing the toner image on the surface by sandwiching and pressing a recording medium holding an unfixed toner image on the surface between the rotation member;
A heat source for heating the recording medium sandwiched between the rotating member and the pressure member;
A driving member that contacts an end of the cylinder and is driven in a circumferential direction of the cylinder;
A recess provided at an end of the cylinder;
A protrusion provided on the inner surface of the driving member, protruding in the direction of the peripheral surface not from the outer peripheral surface of the rotating member through the recess, and transmitting a driving force to the rotating member;
A slope that is provided on the inner surface of the drive member and protrudes obliquely from the outside to the inside of the outer peripheral surface of the rotating member as it approaches the protrusion from the front in the drive direction of the drive member;
A fixing device comprising: A plurality of the recesses are provided at intervals in the circumferential direction,
The fixing device according to claim 2, wherein a plurality of sets of the protruding portion and the inclined surface are provided corresponding to each of the plurality of concave portions. A rotating member having a cylindrical shape and rotating in a circumferential direction of the cylinder;
A pressure member for fixing the toner image on the surface by sandwiching and pressing a recording medium holding an unfixed toner image on the surface between the rotation member;
A heat source for heating the recording medium sandwiched between the rotating member and the pressure member;
A driving member that contacts an end of the cylinder and is driven in a circumferential direction of the cylinder;
A recess provided at an end of the cylinder;
A protrusion provided on the inner surface of the driving member, protruding in the direction of the peripheral surface not from the outer peripheral surface of the rotating member through the recess, and transmitting a driving force to the rotating member;
A slope that is provided on the inner surface of the drive member and protrudes obliquely from the outside to the inside of the outer peripheral surface of the rotating member as it approaches the protrusion from the front in the drive direction of the drive member;
And an image forming device that forms the unfixed toner image on the surface of the recording medium;
An image forming apparatus comprising:

Images