JP2014186315A - Fixing pressing member and fixing device - Google Patents

Abstract

A fixing pressing member capable of maintaining the wear resistance and slidability of a pressing member and an inner peripheral surface of a fixing belt in a good condition for a long time even when driven at a high temperature for a long time and preventing an increase in driving torque. And a fixing device.
A fixing pressing member used in a fixing unit of a fixing device includes a sliding sheet that slides on an inner peripheral surface of a fixing belt of the fixing unit to form a sliding surface, and a sliding sheet. The elastic member 11 is impregnated and held with oil, and the sliding sheet 10 is provided with a plurality of through holes 13.
[Selection] Figure 1

Description

  The present invention relates to a fixing pressing member and a fixing device including an elastic member, and is particularly suitable for use in a fixing portion of an image forming apparatus such as a copying machine, a facsimile machine, or a laser beam printer.

  In an image forming apparatus, a toner image is fixed by heating and pressing a recording medium carrying an unfixed toner image in a fixing device. Such a fixing device includes an endless fixing belt and a pressure roll disposed to face the fixing belt. Inside the fixing belt, there is provided a pressing member that presses the fixing belt against the pressure roll from the inner surface to form a predetermined nip portion.

  It is known that the pressing member provided inside the fixing belt slides with the inner peripheral surface of the fixing belt and wears on the surface of each other. For this reason, normally, a lubricant such as silicone oil is interposed between the pressing member and the inner peripheral surface of the fixing belt to maintain wear resistance. In order to hold such a lubricant well and improve the wear resistance on the sliding surface, a pressing member is proposed in which the surface of the pressing member is coated with a sheet-like member made of a heat-resistant resin and has a concavo-convex shape. (For example, refer to Patent Document 1).

  However, even if the surface of the pressing member is covered with a sheet-like member or has an uneven shape, the lubricant interposed between the pressing member and the fixing belt is squeezed out by long-time driving or high-temperature driving. There is a problem that the torque increases.

JP 2009-047960 A

  In view of such circumstances, the present invention can maintain the wear resistance and slidability of the pressing member and the inner peripheral surface of the fixing belt in a good state for a long time even when driven at a high temperature for a long time, It is an object of the present invention to provide a fixing pressing member and a fixing device that can prevent the increase.

  An aspect of the present invention that solves the above-described problem is a fixing pressing member used in a fixing unit of a fixing device, which slides with an inner peripheral surface of a fixing belt of the fixing unit to form a sliding surface. A sheet and an elastic member fixed to the inner surface of the sliding sheet, wherein the elastic member is impregnated and held with oil, and the sliding sheet has a plurality of through holes. And a fixing pressing member.

  According to this invention, an appropriate amount of oil is automatically applied to the sliding surface on which the pressing member and the fixing belt slide through the through hole provided in the sliding sheet from the elastic member impregnated and held with oil. Small quantities can be supplied. As a result, even when the fixing device is driven at a high temperature for a long time, the wear resistance and slidability of the pressing member and the inner peripheral surface of the fixing belt can be maintained in a good state for a long time, and the fixing that can prevent an increase in driving torque is possible. The pressing member for use can be realized.

  Here, the oil impregnated in the elastic member is preferably impregnated in the elastic member in advance.

  According to this invention, since the elastic member is impregnated with the oil in advance, it is possible to easily and reliably supply the oil to the sliding surface.

  Furthermore, it is preferable that an oil storage section for storing oil to be supplied to the elastic member is provided on the side opposite to the sliding sheet side.

  In this case, the oil impregnated in the elastic member can be supplied from the oil storage unit to the elastic member. As a result, oil impregnation can be performed reliably.

  The oil is preferably silicone oil.

  In this case, the silicone oil excellent in lubricity is impregnated and held in the elastic member, so that the lubrication state on the sliding surface can be kept good.

  The elastic member is preferably silicone rubber.

  In this case, since the silicone rubber capable of stably impregnating and holding oil is applied to the elastic member, the oil can be stably supplied to the sliding surface.

  Moreover, it is preferable that the said sliding sheet is extended from the said sliding surface to the surface which cross | intersects the said sliding surface and the longitudinal direction of the said elastic member.

  In this case, the oil impregnated and held in the elastic member is prevented from oozing out from the surface intersecting the sliding surface and the longitudinal direction of the elastic member. As a result, the oil impregnated and held in the elastic member is reliably used to supply the sliding surface from the through hole, so that the oil can be stably supplied to the sliding surface little by little.

  Another aspect of the present invention is a fixing device comprising the fixing pressing member according to any one of the above aspects and the fixing belt.

  According to the present invention, it is possible to realize a highly reliable fixing device that can maintain the wear resistance and sliding property of the pressing member and the inner peripheral surface of the fixing belt in a good state for a long time and can prevent an increase in driving torque. be able to.

  According to the present invention, an appropriate amount of oil can be automatically supplied little by little to the sliding surface on which the pressing member and the fixing belt slide through the through hole provided in the sliding sheet from the elastic member. . Thereby, even when driven at a high temperature for a long time, the pressing member and the fixing belt can maintain the wear resistance and the sliding property of the inner peripheral surface of the fixing belt in a good condition for a long time and can prevent an increase in driving torque. And a fixing device can be realized.

3 is a perspective view of a fixing pressing member according to Embodiment 1. FIG. It is a cross-sectional view of a fixing pressing member for explaining an oil impregnation step into an elastic member. It is a cross-sectional view for explaining the manufacturing process of the fixing pressing member. 1 is a cross-sectional view of a fixing device including a fixing pressing member according to Embodiment 1. FIG. 6 is a cross-sectional view of a fixing pressing member according to Embodiment 2. FIG. 6 is a cross-sectional view of a fixing pressing member according to Embodiment 3. FIG. FIG. 6 is a perspective view of a fixing pressing member according to a fourth embodiment. FIG. 8 is a cross-sectional view of the fixing pressing member in FIG. 7. It is a cross-sectional view of an example of a fixing pressing member according to another embodiment. It is a cross-sectional view of an example of a fixing pressing member according to another embodiment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
The fixing pressing member (hereinafter referred to as “pressing member”) according to the present invention is suitable for use in a fixing unit of an image forming apparatus.
FIG. 1 is a perspective view of the pressing member. A pressing member 1 shown in FIG. 1 has a length (longitudinal dimension) substantially equal to the width of the fixing belt and a width (short direction dimension) for forming a necessary nip, and has an inner peripheral surface of the fixing belt. The sliding sheet 10 that slides to form the sliding surface 14, the elastic member 11 fixed to the inner surface of the sliding sheet 10, and the elastic member 11 on the side opposite to the sliding sheet 10 side. And the support 12. The sliding sheet 10 is provided with a plurality of through holes 13.

  The sliding surface 14 side of the elastic member 11 is formed into a concavo-convex shape, and the sliding sheet 10 is joined along the concavo-convex convex portion. The plurality of through holes 13 are provided in concave and convex portions. The elastic member 11 according to the present embodiment is made of an elastic body that can be pre-impregnated and held with a predetermined amount of oil through these through holes 13. For this reason, the elastic member 11 needs to have a certain amount of absorbability with respect to oil. A certain level of absorbency is sufficient if it can hold a required amount of oil and the pressure member 1 is pressed so that the oil oozes out little by little from the elastic member 11. In the case of a solid elastic body (non-foamed elastic body), the oil absorption amount is about 5% by mass to 15% by mass with respect to the mass of the elastic member. In the case of a foamed elastic body, the amount of oil absorbed can be further increased. Further, when the foamed elastic body has an open cell structure, the amount of absorption can be further increased. Such an elastic member 11 is selected in consideration of oil absorbability. Therefore, a silicone rubber that can stably impregnate and hold oil is preferable. The oil is preferably a silicone oil having excellent lubricity.

  The through-hole 13 of the sliding sheet 10 is provided to supply the oil impregnated and held in the elastic member 11 to the sliding surface 14. Such a through hole 13 is not particularly limited as long as it can automatically supply oil to the sliding surface 14 in small amounts, and the number, shape, size, and the like of the through holes are not particularly limited. A method for forming the through hole 13 will be described later.

  The sliding sheet 10 is made of a resin having slidability and heat resistance, such as a fluorine resin, a polyimide resin, and the like, and is made of a woven fabric, a knitted fabric or a nonwoven fabric, or a resin film made of resin fibers. A woven fabric, a knitted fabric or a non-woven fabric made of resin fibers is preferable in terms of retaining the lubricant on the sliding surface 14, but a resin film, particularly a film of a fluororesin such as PFA or PTFE is preferable in terms of sliding properties.

  Examples of the support 12 include members such as metals and heat-resistant resins. The support 12 and the elastic member 11 are joined via an adhesive (not shown). The support 12 may not be provided, and the pressing member 1 may be provided by providing the sliding sheet 10 only on the elastic member 11.

  Here, a method for impregnating and holding oil in the elastic member 11 will be described. FIG. 2 is a cross-sectional view of the pressing member for explaining a process of impregnating the elastic member with oil. FIG. 2A shows the pressing member before the elastic member 11 is impregnated with oil. As shown in FIG. 2 (b), the elastic member 11 is impregnated with oil and held by immersing the pressing member 1 in oil for a certain period of time. The oil is impregnated and held up to the oil holding surface 30 of the elastic member 11 in the direction of the arrow shown in FIG. Here, the oil retaining surface 30 refers to a boundary surface between a portion impregnated with oil and a portion not impregnated in the elastic member 11. Such impregnation of oil from the side of the sliding sheet 10 does not require a special process, and can be performed by an extremely easy method of simply immersing the elastic member 11 in oil using the through hole 13. In addition, what is necessary is just to select immersion time suitably with the absorptivity of the oil of the elastic member 11 to be used, and the formation position of the oil holding surface 30. FIG.

  The oil impregnated and held up to the oil holding surface 30 of the elastic member 11 is pressed in the direction of the arrow shown in FIG. 2C when the pressing member 1 is pressed when the pressing member 1 and the fixing belt 15 slide. In addition, a small amount is automatically supplied to the sliding surface 14 through the through hole 13 of the sliding sheet 10. As a result, a lubricant can always be interposed between the pressing member 1 and the fixing belt 15, and the wear resistance and slidability on the sliding surface 14 can be maintained in a good state for a long time.

  According to the pressing member 1 of the present embodiment, even when the lubricant interposed between the pressing member 1 and the fixing belt 15 is easily squeezed out by long-time driving or high-temperature driving, the oil is elastic member 11. Thus, a small amount is automatically supplied to the sliding surface 14 through the through hole 13 of the sliding sheet 10. As a result, the wear resistance and slidability between the pressing member 1 and the fixing belt 15 can be maintained in a good state for a long time without replenishing the lubricant during driving, and an increase in driving torque is prevented. can do.

  Here, the manufacturing method of the pressing member which concerns on this embodiment is demonstrated. FIG. 3 is a cross-sectional view for explaining the manufacturing process of the pressing member.

  The pressing member 1 shown in FIG. 3 (a), for example, integrally forms the sliding sheet 10, the elastic member 11, and the support body 12 by a simple method using a molding die, and on the sliding sheet 10. It can be manufactured by performing uneven processing and forming the through-hole 13 in the sliding sheet 10.

  First, the support 12, the elastic member 11 made of silicone rubber or the like, and the sliding sheet 10 are arranged in the molding die. Next, a pressing member having a concavo-convex shape can be obtained by installing a mold provided with a concavo-convex process or a mold provided with a metal mesh or the like on the sliding sheet 10 and heating with pressure. And the boundary of the sliding sheet 10 and the elastic member 11 is made by making a hole in the recessed part of the sliding sheet 10 of the obtained pressing member, specifically, the recessed part inside the dotted line shown in FIG. It is possible to obtain the pressing member 1 shown in FIG. 3B which has an uneven shape on the surface and in which the through hole 13 is provided in the sliding sheet 10.

  The sliding sheet 10 may be subjected to surface treatment such as etching treatment on the surface opposite to the sliding surface 14 before being subjected to integral molding. This is performed in order to improve the bonding strength with the elastic member 11. Note that the support 12 and the elastic member 11 and the elastic member 11 and the sliding sheet 10 are joined by an adhesive or a primer (not shown).

  In addition, the formation method of the through-hole 13 of the sliding sheet 10 is not specifically limited. Without integrally forming the sliding sheet 10 and the elastic member 11, for example, after the concave and convex processing is performed on the elastic member 11, the sliding sheet in which the through holes 13 are formed in advance is bonded to the elastic member via an adhesive or a primer. 11 may be joined, or a meshed sliding sheet or the like may be joined.

  Next, a fixing device including the pressing member 1 according to the first embodiment will be described. The fixing device is used in a fixing unit of an image forming apparatus, and fixes an unfixed toner image on a recording medium with heat and pressure.

  FIG. 4 is a cross-sectional view of a fixing device including a pressing member. As shown in FIG. 4, the fixing device 2 is provided inside the fixing belt 15, a pressure roll 16 that is provided at a position facing the fixing belt 15 and that is driven to rotate while pressing the fixing belt 15, and the fixing belt 15. And a pressing member 1 that presses the pressure roll 16 via the fixing belt 15 to form a predetermined nip portion. Further, heating means 17 for heating the fixing belt 15 to a predetermined temperature is provided inside the fixing belt 15. A lubricant (not shown) made of silicone oil or the like is interposed on the sliding surface between the pressing member 1 and the fixing belt 15.

  The fixing belt 15 only needs to be able to form a predetermined nip portion by pressure contact with the opposing pressure roll 16. For example, the fixing belt 15 is formed on a metal base having at least one seamless electroformed belt and an outer peripheral surface of the metal base. What comprises an elastic layer is suitable.

  The pressure roll 16 includes a core body 18 made of, for example, metal, and an elastic layer 19 made of rubber or the like formed around the core body 18. The shape of the core 18 is not particularly limited, and may be hollow or not hollow. Moreover, you may provide the tube and coating layer which consist of fluorine-type resins, such as PFA, a silicone rubber, etc. on the surface of the elastic layer 19, as needed.

  The heating unit 17 may be any unit that can heat the fixing belt, and may be provided outside the fixing belt or inside the pressure roll. The heating means 17 is not particularly limited, and examples thereof include a halogen heater, a heating wire heater, an infrared heater, and an electromagnetic induction heater.

  The fixing device 2 having such a configuration includes the pressing member 1 according to the first embodiment. As described above, the oil impregnated and held up to the oil holding surface 30 of the elastic member 11 passes from the elastic member 11 through the through hole 13 of the sliding sheet 10 when the pressing member 1 and the fixing belt 15 slide. The sliding surface 14 is automatically supplied in small amounts. As a result, the wear resistance and slidability between the pressing member 1 and the fixing belt 15 can be maintained in a good state for a long time without replenishing the lubricant during driving, and an increase in driving torque can be prevented. A highly reliable fixing device 2 can be realized.

(Embodiment 2)
FIG. 5 is a cross-sectional view of the pressing member according to the second embodiment. The same members as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  A pressing member 1 </ b> A according to Embodiment 2 includes a sliding sheet 10, an elastic member 11, and a support 12. The sliding sheet 10 has a plurality of through holes 13.

  Unlike the first embodiment, the through-hole 13 of the sliding sheet 10 used in the second embodiment is formed by integrally forming the sliding sheet 10, the elastic member 11, and the support body 12 without performing uneven processing, and then sliding. It is formed by making a hole in the sheet 10. In addition, the sliding sheet | seat in which the through-hole 13 was formed previously may be joined to the elastic member 11 via an adhesive agent or a primer, without integrally molding the sliding sheet | seat 10 and the elastic member 11.

  Further, impregnation and holding of oil in the elastic member 11 is performed by immersing the pressing member 1A in oil for a certain period of time as in the first embodiment. As a result, the oil is impregnated and held up to the oil holding surface 30 of the elastic member 11 in the direction of the arrow shown in FIG. The oil impregnated and held in the elastic member 11 is pressed through the through hole 13 of the sliding sheet 10 when the pressing member 1 is pressed when the pressing member 1A and the fixing belt are slid, and is shown in FIG. A small amount is automatically supplied to the sliding surface 14 in the direction opposite to the direction of the arrow shown. Thereby, the wear resistance and slidability between the pressing member 1A and the fixing belt can be maintained in a good state for a long time, and an increase in driving torque can be prevented.

(Embodiment 3)
FIG. 6 is a cross-sectional view of the pressing member according to the third embodiment. The same members as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In addition to the sliding sheet 10, the elastic member 11, and the support 12 provided on the opposite side of the elastic member 11 from the sliding sheet 10, the pressing member 1B according to the third embodiment further includes the oil storage unit 20. It has.

  The oil storage unit 20 is filled with oil serving as a supply source of oil to be impregnated into the elastic member 11. One side of the oil storage unit 20, that is, the elastic member 11 side, is provided with an open oil supply port 22, and the other is provided with a plug 21 for enclosing oil. Oil is supplied to the elastic member 11 little by little from the oil supply port 22 and impregnated and held in the elastic member 11. Thereby, the oil holding surface 30 is formed in the vicinity of the oil supply port 22. The oil impregnated and held in the elastic member 11 is automatically supplied to the sliding surface 14 little by little through the through hole 13 of the sliding sheet 10.

  Such an oil storage unit 20 is a space provided in the elastic member 11 and the support 12, and is manufactured, for example, by being embedded in the elastic member 11 and the support 12. Note that a tank or the like having a pipe or a hole may be fitted as necessary. The material, shape, size, and the like of the pipe, hole, or tank are not particularly limited as long as they can be impregnated and retained with oil. The number of tubes, holes, or tanks may be single or plural, or a combination thereof.

  According to the pressing member 1 </ b> B of the present embodiment, by providing the oil storage unit 20, the elastic member 11 can be reliably impregnated with oil, and an appropriate amount of oil can be obtained via the through hole 13 of the sliding sheet 10. Can be automatically supplied to the sliding surface 14 little by little. As a result, the wear resistance and slidability between the pressing member 1B and the fixing belt can be maintained in a good state for a long time without replenishing the lubricant during driving, and an increase in driving torque is prevented. can do.

(Embodiment 4)
FIG. 7 is a perspective view of a pressing member according to the fourth embodiment. FIG. 8 is a cross-sectional view of the pressing member in FIG. The same members as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIGS. 7 and 8, the pressing member 1 </ b> C is the same as in the first embodiment except that the sliding sheet 10 is continuous from the sliding surface 14 and extends to the side surface 11 a of the elastic member. Here, the side surface 11 a of the elastic member refers to a surface that intersects the sliding surface 14 and the longitudinal direction of the elastic member 11. The term “extending to the side surface 11a of the elastic member” means that the sliding sheet 10 is provided continuously from the sliding surface 14 so as to cover a part of the side surface 11a of the elastic member. In the fourth embodiment, the sliding sheet 10 is provided on the entire side surface 11a of the elastic member. The sliding sheet 10 is joined to the elastic member 11 via an adhesive or primer (not shown).

  The elastic member 11 is impregnated and held with oil by immersing the pressing member 1C in oil for a certain period of time, as in the first embodiment. Thereby, the oil is impregnated and held up to the oil holding surface 30 of the elastic member 11. In the present embodiment, since the sliding sheet 10 is provided on the entire side surface 11a of the elastic member continuously from the sliding surface 14, the oil impregnated and held in the elastic member 11 oozes out from the side surface 11a of the elastic member. It is prevented. That is, the sliding sheet 10 of the present embodiment is a sliding member that keeps the slidability between the pressing member 1C and the fixing belt good, and prevents oil from seeping out from the side surface 11a of the elastic member. Also functions as a seal member. As a result, the oil impregnated and held in the elastic member 11 is reliably used to supply the sliding surface 14 from the through hole 13, so that the oil can be stably supplied to the sliding surface 14 little by little. It becomes. As a result, even when the fixing device is driven at a high temperature for a long time, the wear resistance and slidability between the pressing member 1C and the fixing belt are maintained in a good state for a long time without replenishing the lubricant during the driving. In addition, the driving torque can be further prevented from being increased while being stably maintained.

(Other embodiments)
Although one embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the above-described embodiment.

  9 and 10 are cross-sectional views of pressing members according to other embodiments. The pressing member 1D shown in FIG. 9 is the same as that of the second embodiment except that the sliding sheet 10 is continuously provided from the sliding surface 14 and provided on the entire side surface 11a of the elastic member. Further, the pressing member 1E shown in FIG. 10 is the same as that of the third embodiment except that the sliding sheet 10 is continuously provided from the sliding surface 14 and provided on the entire side surface 11a of the elastic member.

  Also in such pressing members 1D and 1E, the oil impregnated and held up to the oil holding surface 30 of the elastic member 11 is prevented from oozing out from the side surface 11a of the elastic member. As a result, the oil impregnated and held in the elastic member 11 is reliably used to supply the sliding surface 14 from the through hole 13, so that the oil can be stably supplied to the sliding surface 14 little by little. It becomes.

  Moreover, the pressing members 1C, 1D, and 1E described above can be manufactured by integrally forming the sliding sheet 10, the elastic member 11, and the support 12 by a simple method. Specifically, the sliding sheet 10 having a length and a width that can cover the entire sliding surface 14 (bottom surface) and the side surface 11a of the elastic member 11, the elastic member 11, and the support 12 are bonded. The sliding sheet 10, the elastic member 11, and the support 12 are integrally formed by placing in a molding die having a desired shape via an agent and a primer, and pressurizing and heating. Thereafter, the through hole 13 is formed in the sliding sheet 10. In addition, about the press member 1E, it is necessary to provide the oil storage part 20 separately.

  In the molding of the pressing members 1C, 1D, and 1E, in order to arrange the sliding sheet 10 having a length and a width that can cover the entire bottom surface and the side surface 11a of the elastic member 11 in the molding die, Such arrangement is simpler and more reliable, and the moldability is improved.

  Further, the sliding sheet 10 of the pressing members 1C, 1D, and 1E does not have to be provided continuously from the sliding surface 14 so as to cover the entire side surface 11a of the elastic member. It may be provided so as to cover the part. Here, when covering a part, it is preferable to cover the oil holding surface 30 to the upper side. If the sliding sheet 10 is covered above the oil holding surface 30, the oil impregnated and held in the elastic member 11 oozes out from the side surface 11 a of the elastic member without covering the entire side surface 11 a of the elastic member. Is prevented. As a result, the oil impregnated and held in the elastic member 11 is reliably used to supply the sliding surface 14 from the through hole 13, so that the oil can be stably supplied to the sliding surface 14 little by little. It becomes. Note that the sliding sheet 10 does not have to be formed by integral molding with the elastic member 11. For example, the sliding sheet 10 in which the through holes 13 are formed in advance may be joined to the elastic member 11.

1, 1A, 1B, 1C, 1D, 1E Pressure member 2 Fixing device 10 Sliding sheet 11 Elastic member 11a Elastic member side surface 12 Support body 13 Through hole 14 Sliding surface 15 Fixing belt 16 Pressure roll 17 Heating means 18 Core Body 19 Elastic layer 20 Oil reservoir 21 Plug 22 Oil supply port 30 Oil holding surface

Claims (7)

A fixing pressing member used in a fixing unit of a fixing device,
A sliding sheet that slides with the inner peripheral surface of the fixing belt of the fixing unit to form a sliding surface, and an elastic member fixed to the inner surface of the sliding sheet,
Oil is impregnated and held in the elastic member,
A fixing pressing member, wherein the sliding sheet is provided with a plurality of through holes. The fixing pressing member according to claim 1,
The oil impregnated in the elastic member is
A fixing pressing member, wherein the elastic member is impregnated in advance. The fixing pressing member according to claim 1 or 2,
A fixing pressing member, wherein an oil storage part for storing oil to be supplied to the elastic member is provided on the side opposite to the sliding sheet side. The fixing pressing member according to any one of claims 1 to 3,
The fixing pressing member, wherein the oil is silicone oil. In the fixing pressing member according to any one of claims 1 to 4,
The fixing pressing member, wherein the elastic member is silicone rubber. In the fixing pressing member according to any one of claims 1 to 5,
The fixing pressing member, wherein the sliding sheet extends from the sliding surface to a surface intersecting the sliding surface and a longitudinal direction of the elastic member. A fixing device comprising the fixing pressing member according to claim 1 and the fixing belt.

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