JP2022089667A - Method for manufacturing pressure unit - Google Patents

Abstract

To assemble an endless belt to an outside of a slide sheet before applying grease, thereby manufacturing a pressure unit that uniformly holds the grease between the endless belt and the slide sheet.SOLUTION: A pressure unit 82 comprises: an endless belt 130; a slide sheet 150; a pressure pad P; and grease GR. The slide sheet 150 is in contact with an inner peripheral surface 131 of the endless belt 130. The pressure pad P sandwiches the slide sheet 150 between the endless belt 130 and the pressure pad. The pressure pad P has a first pressure pad P1 and a second pressure pad P2 separated in a circumferential direction. The grease GR is located between the endless belt 130 and the slide sheet 150. A method for manufacturing the pressure unit 82 includes inserting a nozzle NZ capable of discharging the grease GR from its leading end between the endless belt 130 and the slide sheet 150 and between the first pressure pad P1 and the second pressure pad P2 in the circumferential direction, and discharging the grease GR while pulling out the nozzle NZ.SELECTED DRAWING: Figure 6

Description

The present invention relates to a method for manufacturing a pressurizing unit in a fixing device.

Conventionally, a method of discharging a lubricant to the inner peripheral surface of an endless belt in a fixing device has been disclosed (see Patent Document 1). In Patent Document 1, the lubricant is uniformly supplied to the endless belt by moving the nozzle at a constant speed inside the endless belt while dropping the lubricant from the tip of a dispenser having a horizontally long nozzle at a constant discharge amount. Is described.

Japanese Unexamined Patent Publication No. 2016-118657

When assembling the pressurizing unit of the fixing device, there is a step of assembling the endless belt on the outside of the sliding sheet that is in sliding contact with the endless belt. For example, when the endless belt is attached to the outside of the sliding sheet after applying a lubricant such as grease to the inner peripheral surface of the endless belt, the applied grease easily adheres to other members, so that the pressure unit Even after assembly, it is difficult to ensure that the grease is uniform in the longitudinal direction of the endless belt.

Therefore, the present invention provides a method for manufacturing a pressure unit in which an endless belt is assembled on the outside of a sliding sheet and then grease is applied to uniformly hold the grease between the endless belt and the sliding sheet. With the goal.

The pressure unit according to the present invention for solving the above problems includes an endless belt, a sliding sheet, a pressure pad, and grease. The sliding sheet is in contact with the inner peripheral surface of the endless belt. The pressure pad sandwiches the sliding sheet between the endless belt and the pressure pad. The pressure pad has a first pressure pad and a second pressure pad arranged apart from the first pressure pad in the circumferential direction of the endless belt. The grease is located between the endless belt and the sliding sheet. In the method of manufacturing the pressurizing unit, a nozzle capable of discharging grease from the tip is inserted between the endless belt and the sliding sheet and between the first pressurizing pad and the second pressurizing pad in the circumferential direction. In the method of manufacturing the pressurizing unit, after inserting the nozzle, grease is discharged while pulling out the nozzle.

According to this configuration, after assembling the endless belt to the outside of the sliding sheet, grease is applied between the first pressure pad and the second pressure pad to apply grease between the endless belt and the sliding sheet. It is possible to manufacture a pressurizing unit that is uniformly held in the air. Further, since the grease is applied directly between the endless belt and the sliding sheet, the grease can be interposed between the endless belt and the sliding sheet from the start of movement of the endless belt. Further, since the nozzle is inserted between the first pressure pad and the second pressure pad, it is easy to insert the nozzle.

Further, in the method for manufacturing the pressure unit described above, before the nozzle is inserted between the endless belt and the sliding sheet, the endless belt covering the sliding sheet is moved in the width direction of the endless belt to move the sliding sheet. The nozzle may be inserted between the endless belt and the sliding sheet after the nozzle is exposed.

According to this, since the endless belt is moved in the width direction to expose a part of the sliding sheet and then the nozzle is inserted, it is easy to insert the nozzle between the endless belt and the sliding sheet.

Further, in the above-mentioned manufacturing method of the pressurizing unit, when the nozzle is inserted between the endless belt and the sliding sheet, the nozzle is brought into contact with the outer peripheral surface of the sliding sheet and inserted while being pressed against the sliding sheet. May be good.

According to this, it is easy to insert the nozzle between the endless belt and the sliding sheet.

Further, in the width direction of the endless belt, the dimension of the endless belt may be larger than the dimension of the sliding sheet.

According to this, it is possible to prevent the grease located between the endless belt and the sliding sheet from leaking to the endless belt side.

Further, in the pressure unit described above, the size of the pressure pad is smaller than the size of the sliding sheet in the width direction of the endless belt, and in the method for manufacturing the pressure unit described above, grease is applied in the width direction. The nozzle may be configured to discharge from the nozzle in a range wider than the range in which the pressure pad is arranged and narrower than the range in which the sliding sheet is arranged.

According to this, the grease can be distributed to the required range in the nip, and the grease can be prevented from leaking from between the endless belt and the sliding sheet.

Further, in the above-mentioned pressurizing unit, after the grease has been discharged, the nozzle is reciprocated in the width direction of the endless belt with the tip of the nozzle between the endless belt and the sliding sheet, and then the endless belt. It may be configured to be pulled out from between the sliding sheet and the sliding sheet.

According to this, it is possible to suppress the grease from being pulled from the tip of the nozzle and to prevent the grease from adhering to the outside in the width direction of the sliding sheet.

Further, the second pressure pad may be arranged downstream of the first pressure pad in the rotation direction of the endless belt, and may have a higher durometer hardness than the first pressure pad.

According to this, by discharging grease to the upstream side of the second pressurizing pad having the largest nip pressure, when the endless belt is rotated after assembling the pressurizing unit, it is first niped by the second pressurizing pad. Grease can reach the part.

Further, in the above-mentioned pressurizing unit, a constant amount of grease may be discharged from the nozzle with respect to the amount of movement in the width direction of the endless belt.

According to this, it is possible to hold a uniform amount of grease in the width direction.

Further, in the above-mentioned pressurizing unit, after the grease has been discharged and the nozzle is pulled out, the endless belt may be rotated while being heated.

According to this, by rotating the endless belt while heating, the grease can be uniformly spread on the inner peripheral surface of the endless belt.

Further, the facing surface of the sliding sheet facing the inner peripheral surface of the endless belt may have a contact portion that contacts the endless belt and a plurality of recesses that are recessed from the contact portion and do not contact the endless belt.

According to this, friction can be reduced by reducing the contact area with the endless belt, and grease can be held in the recess.

Further, the base material of the endless belt and the base material of the sliding sheet may be configured to be polyimide.

According to this, the wear resistance of the endless belt and the sliding sheet is improved.

Further, the grease may be composed of a base oil containing perfluoropolyether and polytetrafluoroethylene as a thickener.

According to the present invention, it is possible to manufacture a pressurizing unit in which grease is uniformly applied between the endless belt and the sliding sheet by applying grease after assembling the endless belt to the outside of the sliding sheet.

It is sectional drawing which shows the laser printer which concerns on one Embodiment of this invention. It is sectional drawing which shows the fixing device. FIG. 2 is an enlarged view (a) showing a part of the endless belt and the sliding sheet in FIG. 2, and a perspective view (b) showing an enlarged view of the facing surface of the sliding sheet. It is a figure explaining the dimensional relationship in the width direction of an endless belt, a sliding sheet and a pressure pad. It is a perspective view of a pressurizing unit and a dispenser which discharges grease. It is sectional drawing of the heating unit seen from the width direction before inserting a nozzle (a) and in a state (b) with a nozzle inserted. It is a perspective view of the heating unit in the state (a) in which the endless belt is moved in the width direction to expose a part of the sliding sheet, and in the state (b) in which the nozzle is pressed against a part of the sliding sheet. The heating unit in the state (a) in which the nozzle is inserted between the endless belt and the sliding sheet from the state of FIG. 7 (b) and the state (b) in which the endless belt is returned to the original position after the nozzle is inserted. It is a perspective view. It is a perspective view of the heating unit in the state of discharging grease while pulling out a nozzle. It is sectional drawing of the heating unit in the state (a) in which the discharge of grease is completed, and the state (b) in which the nozzle is reciprocated in the width direction.

Hereinafter, an embodiment of the invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the fixing device 8 according to the embodiment is used in an image forming device 1 such as a laser printer. The image forming apparatus 1 includes a main body housing 2, a sheet supply unit 3, an exposure apparatus 4, a developer image forming unit 5, and a fixing device 8.

The sheet supply unit 3 is provided in the lower part of the main body housing 2 and includes a sheet tray 31 for accommodating a sheet S such as paper, and a sheet supply mechanism 32. The sheet S in the sheet tray 31 is supplied to the developer image forming unit 5 by the sheet supply mechanism 32.

The exposure device 4 is arranged in the upper part of the main body housing 2 and includes a light source device (not shown), a polygon mirror shown by omitting a reference numeral, a lens, a reflecting mirror, and the like. The exposure device 4 exposes the surface of the photoconductor drum 61 by scanning a light beam (see one-dot chain line) based on image data emitted from the light source device on the surface of the photoconductor drum 61 at high speed.

The developer image forming unit 5 is arranged below the exposure apparatus 4. The developer image forming unit 5 is configured as a process cartridge, and is removable from the main body housing 2 through an opening formed when the front cover 21 provided on the front portion of the main body housing 2 is opened. The developer image forming unit 5 includes a photoconductor drum 61, a charger 62, a transfer roller 63, a developing roller 64, a supply roller 65, and a developer accommodating unit 66 for accommodating a developer made of dry toner. I have.

The developer image forming unit 5 uniformly charges the surface of the photoconductor drum 61 by the charger 62. After that, the surface of the photoconductor drum 61 is exposed by the light beam from the exposure apparatus 4, so that an electrostatic latent image based on the image data is formed on the surface. Further, the developer image forming unit 5 supplies the developer in the developer accommodating unit 66 to the developing roller 64 via the supply roller 65.

Then, the developer image forming unit 5 supplies the developer on the developing roller 64 to the electrostatic latent image formed on the photoconductor drum 61. As a result, the electrostatic latent image is visualized and a developer image is formed on the photoconductor drum 61. After that, the developer image forming unit 5 conveys the sheet S supplied from the sheet supply unit 3 between the photoconductor drum 61 and the transfer roller 63, so that the developer image on the photoconductor drum 61 is transferred to the sheet S. Transcribe.

The fixing device 8 is arranged behind the developer image forming unit 5. The details of the fixing device 8 will be described later. The fixing device 8 heat-fixes the developer image to the sheet S by passing the developer image through the transferred sheet S. The image forming apparatus 1 discharges the sheet S on which the developer image is heat-fixed onto the paper discharge tray 22 outside the main body housing 2 by the transport roller 23 and the discharge roller 24.

As shown in FIG. 2, the fixing device 8 includes a heating unit 81 and a pressurizing unit 82. The pressurizing unit 82 is urged toward the heating unit 81 by a pressing mechanism (not shown). In the following description, the direction in which the pressurizing unit 82 is urged to the heating unit 81 is referred to as a “predetermined direction”. In the present embodiment, the predetermined direction is a direction orthogonal to the width direction and the moving direction described later, and is a direction in which the heating unit 81 and the pressurizing unit 82 face each other.

The heating unit 81 includes a heater 110 and a rotating body 120. Further, the pressure unit 82 includes an endless belt 130, a pressure pad P, a holder 140, a sliding sheet 150, an upstream belt guide 160, a downstream belt guide 170, a stay 180, and a grease GR. ing. In the following description, the width direction of the endless belt 130 is simply referred to as "width direction". The width direction is the direction in which the rotation axis X1 of the rotating body 120 extends. The width direction is orthogonal to a predetermined direction.

The heater 110 heats at least one of the rotating body 120 and the endless belt 130. In the present embodiment, the heater 110 is arranged inside the rotating body 120 and heats the rotating body 120.

The rotating body 120 is a cylindrical roller and has a raw tube 121 and an elastic layer 122. The raw pipe 121 is a metal pipe. The elastic layer 122 is rotatable about the rotation axis X1. The rotating body 120 is driven by a motor (not shown) provided in the image forming apparatus 1 to rotate. The elastic layer 122 is provided on the outer periphery of the raw tube 121. In other words, the rotating body 120 has an elastic layer 122 on its surface. The elastic layer 122 has elasticity.

The endless belt 130 is an endless belt made of metal or the like. The endless belt 130 has a width larger than the width of the maximum sheet S conveyed by the image forming apparatus 1. The endless belt 130 comes into contact with the outer peripheral surface of the rotating body 120. The endless belt 130 is conveyed with the sheet S sandwiched between the endless belt 130 and the rotating body 120. The endless belt 130 rotates clockwise in FIG. 2 due to friction with the rotating body 120 or the seat S when the rotating body 120 rotates.

The pressure pad P is a member that sandwiches the endless belt 130, the sliding sheet 150, and the sheet S with the rotating body 120 to form the nip portion NP. The pressure pad P sandwiches the sliding sheet 150 with the endless belt 130. In the following description, the moving direction of the endless belt 130 in the nip portion NP is simply referred to as “moving direction”. In addition, in this embodiment, the moving direction is a direction along the outer peripheral surface of the rotating body 120, but since this direction is a direction along a direction substantially orthogonal to a predetermined direction and a width direction, it is a predetermined direction. It is shown as a direction orthogonal to the width direction. The moving direction is the same as the transport direction of the sheet S at the nip portion NP.

The pressure pad P has a first pressure pad P1 and a second pressure pad P2. The second pressure pad P2 is located away from the first pressure pad P1 on the downstream side in the moving direction. The second pressure pad P2 has a higher durometer hardness than the first pressure pad P1.

Durometer hardness is specified in ISO7619-1. The durometer hardness is a value obtained from the pushing depth of the pushing needle when the specified needle is pushed into the test piece under the specified conditions. For example, when the durometer hardness of the elastic layer 122 is 5, the durometer hardness of the first pressure pad P1 is preferably 6 to 10, and the durometer hardness of the second pressure pad P2 is preferably 70 to 90.

The first pressure pad P1 is a rectangular parallelepiped member. The first pressure pad P1 is made of rubber such as silicon rubber. The first pressure pad P1 has elasticity and is elastically deformable. Since the first pressure pad P1 is thicker than the elastic layer 122, the amount of deformation of the elastic layer 122 when the rotating body 120 and the first pressure pad P1 are pressed against each other is the first pressure pad P1. Is smaller than the amount of deformation of. The first pressure pad P1 sandwiches the endless belt 130 with the rotating body 120 to form the first nip portion NP1.

The second pressure pad P2 is a rectangular parallelepiped member. The second pressure pad P2 is made of rubber such as silicon rubber. The second pressure pad P2 has elasticity and is elastically deformable. The second pressure pad P2 has a higher durometer hardness than the elastic layer 122, but the second pressure pad P2 is thicker than the elastic layer 122, so that the rotating body 120 and the first pressure pad P1 are mutually. When pressed, the amount of deformation of the elastic layer 122 is smaller than the amount of deformation of the first pressure pad P1. The second pressure pad P2 sandwiches the endless belt 130 with the rotating body 120 to form the second nip portion NP2.

In the moving direction, between the first nip portion NP1 and the second nip portion NP2, there is a third nip portion NP3 on which the pressure from the pressurizing unit 82 does not directly act. In the third nip portion NP3, although the endless belt 130 comes into contact with the rotating body 120, almost no pressure is applied because there is no member sandwiching the endless belt 130 with the rotating body 120. Therefore, the sheet S passes through the third nip portion NP3 while being heated by the rotating body 120 and with almost no pressure. In the present embodiment, the region from the upstream end of the first nip portion NP1 to the downstream end of the second nip portion NP2, that is, the entire region where the outer peripheral surface of the endless belt 130 and the rotating body 120 come into contact with each other is referred to as the nip portion NP. Refer to. That is, in the present embodiment, the nip portion NP includes a portion to which the pressing force from the first pressurizing pad P1 and the second pressurizing pad P2 is not applied.

Of the nip portion NP in which the rotating body 120 and the endless belt 130 are in contact, the range in which neither the first pressurizing pad P1 nor the second pressurizing pad P2 is pressed, that is, in the moving direction of the third nip portion NP3. The size is 20 to 50% of the size in the moving direction of the entire range of the nip portion NP. The pressing range of the second pressure pad P2, that is, the size of the second nip portion NP2 in the moving direction is 10 to 20% of the size of the entire range of the nip portion NP in the moving direction.

The holder 140 is a member that holds the pressure pad P.

The sliding sheet 150 is arranged so as to be sandwiched between the inner peripheral surface 131 of the endless belt 130 and the pressure pad P. The sliding sheet 150 is in contact with the inner peripheral surface 131 of the endless belt 130. The sliding sheet 150 is in contact with the inner peripheral surface 131 of the endless belt 130. When the rotating body 120 rotates, the sliding sheet 150 always comes into contact with the endless belt 130. On the other hand, when the rotating body 120 rotates, each part of the inner peripheral surface 131 of the endless belt 130 alternately repeats a state of being in contact with the sliding sheet 150 and a state of not being in contact with the sliding sheet 150.

The sliding sheet 150 is a sheet-like member. The base material of the sliding sheet 150 is a heat-resistant resin having a glass transition temperature of 140 ° C. or higher. In this embodiment, the sliding sheet 150 is made of polyimide. That is, in this embodiment, the base material of the endless belt 130 and the base material of the sliding sheet 150 are both polyimide. As the sliding sheet 150, those having various coatings on the surface can be adopted.

As shown in FIG. 3A, the sliding sheet 150 has a facing surface 151 facing the inner peripheral surface 131 of the endless belt 130. As shown in FIG. 3B, the facing surface 151 is formed in an uneven shape in which a plurality of polygonal sides serve as ridges. In the present embodiment, the facing surface 151 is formed in an uneven shape in which the sides of a plurality of squares are ridges. The facing surface 151 has a contact portion 152 that contacts the endless belt 130, and a plurality of recesses 153 that do not contact the endless belt 130.

The ratio of the area of the contact portion 152 to the facing surface 151 having a predetermined area is 50% or less. The contact portion 152 is located on the side of the square formed on the facing surface 151. The contact portion 152 extends obliquely with respect to the rotation direction, that is, the movement direction of the endless belt 130. The contact portion 152 is formed with a groove 154 extending along the extending direction of the contact portion 152.

The groove 154 extends diagonally with respect to the moving direction of the endless belt 130. The depth of the groove 154 is 0.1 to 0.005 times the depth of the recess 153. The groove 154 has a first groove 154A and a second groove 154B.

The first groove 154A extends in a direction approaching the center C in the width direction of the sliding sheet 150 toward the moving direction of the endless belt 130. The first groove 154A extends continuously. The second groove 154B extends in a direction away from the center C in the width direction of the sliding sheet 150 toward the moving direction of the endless belt 130. The second groove 154B is divided into the first groove 154A and extends intermittently.

The recess 153 is a portion recessed from the contact portion 152 in a direction away from the endless belt 130. The recess 153 is surrounded by the contact portion 152. In the present embodiment, since the contact portion 152 is formed in a square shape, the recess 153 has a quadrangular pyramid shape with the bottom as the apex.

As shown in FIG. 4, in the width direction, the dimension L1 of the endless belt 130 is larger than the dimension L2 of the sliding sheet 150 (L1> L2). In the width direction, the dimension L3 of the pressure pad P is smaller than the dimension L2 of the sliding sheet 150 (L3 <L2). In the present embodiment, the distance D1 from the end of the endless belt 130 at one end in the width direction to the sliding sheet 150 is the pressure pad P from the end of the sliding sheet 150 at one end in the width direction. Distance to is smaller than D2.

The grease GR is arranged in a range wider than the range in which the pressure pad P is arranged (the range of the dimension L3) and narrower than the range in which the sliding sheet 150 is arranged (the range of the dimension L2). (In FIG. 4, it is indicated by L4.). Since the grease GR flows when the endless belt 130 is rotated, it does not necessarily stay in this range (range of L4).

The base material of the endless belt 130 is made of a heat-resistant resin having a glass transition temperature of 140 ° C. or higher. Examples of the heat-resistant resin having a glass transition temperature of 140 ° C. or higher include polyimide (glass transition temperature 220 ° C.), polyether ether ketone (glass transition temperature 143 ° C.), and polyetherimide (glass transition temperature 216 ° C.). In this embodiment, the endless belt 130 is made of polyimide. The surface of the endless belt 130 may be coated with a fluororesin or the like.

The micro-hardness of the endless belt 130 by the nanoindentation method is larger than the micro-hardness of the sliding sheet 150. The micro-hardness is measured according to the ultra-micro load hardness test method specified in Japanese Industrial Standards JIS Z2255. The minute hardness is the minute hardness of the contact portion 152 on the inner peripheral surface 131 of the endless belt 130 and the facing surface 151 of the sliding sheet 150. For example, the minute hardness may be measured by using a film material which is a material of the endless belt 130 and the sliding sheet 150.

The surface roughness Ra of the inner peripheral surface 131 of the endless belt 130 measured along the rotation direction of the endless belt 130 is the surface roughness of the facing surface 151 of the sliding sheet 150 facing the endless belt 130 measured along the rotation direction. Is smaller than Ra. The surface roughness Ra is measured according to the method specified in Japanese Industrial Standards JIS B0601.

Returning to FIG. 2, the upstream belt guide 160 is a member that guides the movement of the endless belt 130 upstream of the nip portion NP in the transport direction of the seat S. The upstream belt guide 160 has a curved surface so that the endless belt 130 can rotate smoothly.

The downstream belt guide 170 is a member that guides the movement of the endless belt 130 downstream of the nip portion NP in the transport direction of the seat S. The upstream belt guide 160 has a curved surface so that the endless belt 130 can rotate smoothly.

The stay 180 is a member that supports the holder 140, the upstream belt guide 160, and the downstream belt guide 170. The stay 180 is formed by press-molding a metal plate.

The grease GR (see FIG. 4) is provided between the endless belt 130 and the sliding sheet 150, and is for reducing the friction between the endless belt 130 and the sliding sheet 150. The grease GR is located on the inner peripheral surface 131 of the endless belt 130, the contact portion 152 of the sliding sheet 150, the recess 153, and the groove 154.

Grease GR contains a base oil, a thickener, and an additive. The grease GR preferably has a consistency of 330 to 385 at 25 ° C. It is more desirable that the grease GR has a consistency of 335 to 350 at 25 ° C. The yield stress of the grease GR is 50 to 250 Pa.

The consistency and yield stress of the grease GR can be adjusted by the mixing ratio of the base oil and the thickener.

Consistency is measured according to the method specified in Japanese Industrial Standards JIS K2220. The consistency of the grease GR is determined by dropping the cone attached to the consistency meter onto the sample filled in the pot at 25 ° C and reading the depth of entry for 5 seconds (see JIS K2220 7.1).

The yield stress in the present application is a stress value when the storage elastic modulus G ′ = loss elastic modulus G ″. The storage elastic modulus G ′ and the loss elastic modulus G ″ are defined by the Japanese Industrial Standard JIS K7244-10. It is measured with a leometer (viscous modulus measuring device). In this case, the measurement frequency of the rheometer is 1 Hz.
For the storage elastic modulus G'and the loss elastic modulus G', the strain γ0, the phase difference δ, and the stress peak σ0 can be measured by measuring the stress while gradually increasing the strain.
The storage elastic modulus G'is obtained by dividing the peak value of the elastic body component by the peak value of the strain (G'= σ0 × cosδ ÷ γ0).
The loss elastic modulus G "is obtained by dividing the peak value of the viscous component by the peak value of strain (G" = σ0 × sinδ ÷ γ0).

The base oil consists of fluorine oil. Fluorine oil is, for example, perfluoropolyether (PFPE), chlorotrifluoroethylene (CTFE). In this embodiment, the base oil contains a perfluoropolyether. The viscosity of the base oil of this embodiment is 100 to 400 mm ² / S at 40 ° C.

The thickener consists of a solid lubricant containing fluorine. In this embodiment, the fluorine-containing solid lubricant is polytetrafluoroethylene (PTFE).

The additive is a solid lubricant with layered crystals and no fluorine. Fluorine-free layered solid lubricants are, for example, melamine cyanurate (MCA), molybdenum disulfide, graphite. In this embodiment, the solid lubricant is melamine cyanurate (MCA). The particle size of melamine cyanurate is 10 to 20 times larger than the particle size of polytetrafluoroethylene (PTFE).

Next, a method of manufacturing the pressurizing unit 82 will be described with reference to FIGS. 5 to 9.
In the present embodiment, when the pressurizing unit 82 is manufactured, the grease GR is supplied and held between the endless belt 130 and the sliding sheet 150 after being assembled without arranging the grease GR. Here, a method of filling the pressure unit 82, which is a feature of the present invention, with grease GR after assembly will be described.

As shown in FIG. 5, in order to fill the grease GR, a dispenser DI having a nozzle NZ capable of discharging the grease GR from the tip is used. The tip of the nozzle NZ has a tapered shape, and has substantially the same length as the dimension L1 of the endless belt 130 in the width direction. In the present embodiment, the dispenser DI is moved in the width direction with the pressurizing unit 82 fixed.

As shown in FIGS. 6A and 6B, when the grease GR is discharged, the nozzle NZ is inserted between the endless belt 130 and the sliding sheet 150 and with the first pressure pad P1 in the circumferential direction. It is inserted between the second pressure pads P2. The circumferential direction is the direction in which the endless belt 130 rotates, and coincides with the moving direction of the endless belt 130 in the nip portion NP.

To insert the nozzle NZ between the endless belt 130 and the sliding sheet 150, first, as shown in FIG. 7A, before inserting the nozzle NZ between the endless belt 130 and the sliding sheet 150, The endless belt 130 covering the sliding sheet 150 is moved in the width direction of the endless belt 130. Then, the end portion of the sliding sheet 150 is exposed.

Next, as shown in FIG. 7B, the tip of the nozzle NZ is brought into contact with the end of the exposed sliding sheet 150, and the tip of the nozzle NZ is pushed downward. Then, a gap GA is formed between the end of the sliding sheet 150 and the endless belt 130. In order to push the tip portion of the nozzle NZ downward, a method of pressing the nozzle NZ downward by a pressing member (not shown) may be used, or a method of moving the entire nozzle NZ downward may be used.

Next, as shown in FIG. 8A, the nozzle NZ is inserted into the gap GA formed between the end of the sliding sheet 150 and the endless belt 130. In this way, when the nozzle NZ is inserted between the endless belt 130 and the sliding sheet 150, after the sliding sheet 150 is exposed, the nozzle NZ is brought into contact with the outer peripheral surface of the sliding sheet 150 and slides. Insert while pressing against the sheet 150.

Next, as shown in FIG. 8B, the nozzle NZ is inserted to a predetermined position. Then, as shown in FIG. 9, the grease GR is discharged while pulling out the nozzle NZ from a predetermined position.
In this case, a constant amount of grease GR is discharged from the nozzle NZ with respect to the amount of movement of the endless belt 130 in the width direction.

As shown in FIG. 4, the predetermined position PS1 is a range wider than the range in which the pressure pad P is arranged (the range of the dimension L3) in the width direction, and the sliding sheet 150 is arranged. It is a range narrower than the existing range (range of dimension L2).

Next, as shown in FIG. 10 (a), after the discharge of the grease GR is completed, the tip of the nozzle NZ is between the endless belt 130 and the sliding sheet 150 as shown in FIG. 10 (b). Then, the nozzle NZ is reciprocated in the width direction of the endless belt 130, and then pulled out from between the endless belt 130 and the sliding sheet 150. That is, after the discharge is completed, the tip of the nozzle NZ is slightly reciprocated so that the grease GR does not string.

Next, after the discharge of the grease GR is completed and the nozzle NZ is pulled out, the rotating body 120 is brought into contact with the rotating body 120, and the endless belt 130 is rotated while being heated. When the endless belt 130 is rotated about 10 times while being heated, the grease GR spreads over the inner peripheral surface 131 of the endless belt 130.

Based on the above, the following effects can be obtained in the present embodiment.
The pressurizing unit 82 holds the grease GR between the endless belt 130 and the sliding sheet 150 to reduce the sliding resistance. If the endless belt 130 is attached to the outside of the sliding sheet 150 after the grease GR is applied to the inner peripheral surface of the endless belt 130, the applied grease GR tends to adhere to other members, so that the pressure unit is used. Even after assembling the 82, it is difficult to reliably make the grease GR uniform in the width direction of the endless belt 130.
However, according to the method for manufacturing the pressurizing unit 82 in the present embodiment, the nozzle NZ capable of discharging the grease GR from the tip is provided between the endless belt 130 and the sliding sheet 150 and in the circumferential direction of the first pressurizing pad. It is inserted between P1 and the second pressure pad P2, the nozzle NZ is inserted, and then the grease GR is discharged while pulling out the nozzle NZ. Therefore, after assembling the endless belt 130 to the outside of the sliding sheet 150, the grease GR is applied between the first pressure pad P1 and the second pressure pad P2 to slide the grease GR with the endless belt 130. It is possible to manufacture a pressurizing unit that is uniformly held between the moving sheets 150. Further, since the grease is applied directly between the endless belt 130 and the sliding sheet 150, the grease GR can be interposed between the endless belt 130 and the sliding sheet 150 from the start of movement of the endless belt 130. Further, since the nozzle NZ is inserted between the first pressure pad P1 and the second pressure pad P2, it is easy to insert the nozzle NZ.

Further, when the nozzle NZ is inserted between the endless belt 130 and the sliding sheet 150, the nozzle NZ is brought into contact with the outer peripheral surface of the sliding sheet 150 and inserted while being pressed against the sliding sheet 150. Therefore, it is easy to insert the nozzle NZ between the endless belt 130 and the sliding sheet 150.

Further, when the nozzle NZ is inserted between the endless belt 130 and the sliding sheet 150, the nozzle NZ is brought into contact with the outer peripheral surface of the sliding sheet 150 and inserted while being pressed against the sliding sheet 150. Therefore, it is easy to insert the nozzle NZ between the endless belt 130 and the sliding sheet 150.

Further, in the width direction of the endless belt 130, the dimension L1 of the endless belt 130 is larger than the dimension L2 of the sliding sheet 150. Therefore, it is possible to prevent the grease GR located between the endless belt 130 and the sliding sheet 150 from leaking to the endless belt 130 side.

Further, in the width direction of the endless belt 130, the dimension L3 of the pressure pad P is smaller than the dimension L1 of the sliding sheet 150. Then, when the pressurizing unit 82 is manufactured, the grease GR is set in a range L4 wider than the range in which the pressurizing pad P is arranged (the range of the dimension L3) and the range in which the sliding sheet 150 is arranged (the range in which the sliding sheet 150 is arranged). Discharge from the nozzle NZ to a range L4 narrower than the range of the dimension L2). Therefore, the grease GR can be spread over the range required for the nip, and the grease GR can be prevented from leaking from between the endless belt 130 and the sliding sheet 150.

Further, after the discharge of the grease GR is completed, the nozzle NZ is reciprocated in the width direction of the endless belt 130 with the tip of the nozzle NZ between the endless belt 130 and the sliding sheet 150, and then the endless belt 130 is reciprocated. And pull out from between the sliding sheet 150. Therefore, it is possible to suppress the grease GR from being pulled from the tip of the nozzle NZ and to prevent the grease GR from adhering to the outside in the width direction of the sliding sheet 150.

Further, the second pressure pad P2 is arranged downstream of the first pressure pad P1 in the rotation direction of the endless belt 130, and has a higher durometer hardness than the first pressure pad P1. Therefore, when the endless belt 130 is rotated after assembling the pressurizing unit 82 by discharging the grease GR to the upstream side of the second pressurizing pad P2 having the largest nip pressure, the second pressurizing pad P2 first. The grease GR can reach the portion nipped by.

Further, in the pressurizing unit 82, a constant amount of grease GR is discharged from the nozzle NZ with respect to the amount of movement in the width direction of the endless belt 130. Therefore, a uniform amount of grease GR can be held in the width direction.

Further, in the pressurizing unit 82, after the discharge of the grease GR is completed and the nozzle NZ is pulled out, the endless belt 130 is rotated while being heated. Therefore, by rotating the endless belt 130 while heating, the grease GR can be uniformly spread on the inner peripheral surface 131 of the endless belt 130.

Further, the facing surface 151 of the sliding sheet 150 facing the inner peripheral surface 131 of the endless belt 130 has a contact portion 152 that contacts the endless belt 130 and a plurality of recesses that are recessed from the contact portion 152 and do not contact the endless belt 130. It has 153 and. Therefore, the friction can be reduced by reducing the contact area with the endless belt 130, and the grease GR can be held in the recess 153.

Further, the base material of the endless belt 130 and the base material of the sliding sheet 150 are polyimide. Therefore, the wear resistance of the endless belt 130 and the sliding sheet 150 is improved.

The present invention is not limited to the above embodiment, and can be used in various forms as illustrated below.
In the above embodiment, the dispenser DI is moved in the width direction with the pressurizing unit 82 fixed when the grease GR is discharged, but the dispenser DI is fixed and the pressurizing unit 82 is moved in the width direction. May be.

In the above embodiment, when the nozzle NZ is inserted between the endless belt 130 and the sliding sheet 150, the nozzle NZ in contact with the sliding sheet 150 is pushed to create a gap between the endless belt 130 and the sliding sheet 150. I had opened the GA, but I am not limited to this method. For example, the sliding sheet 150 itself may be pushed instead of the nozzle NZ to open a gap GA between the endless belt 130 and the sliding sheet 150.

In the above embodiment, a cylindrical roller having a built-in heater 110 is exemplified as the rotating body, but the present invention is not limited to this, and for example, an endless belt in which the inner peripheral surface is heated by the heater may be used. .. Further, an external heating method in which the heater is arranged outside the rotating body to heat the outer peripheral surface of the rotating body, or an IH (Induction Heating) method may be used. Further, a heater may be arranged inside the endless belt to indirectly heat the rotating body in contact with the outer peripheral surface of the endless belt. Further, the rotating body and the endless belt may each have a built-in heater.

In the above embodiment, the base material of the endless belt 130 and the base material of the sliding sheet 150 are both polyimides, but the present invention is not limited to this, and the base material of the endless belt and the base material of the sliding sheet are not limited to this. And, at least one of them may be a polyimide.
For example, the base material of the endless belt may be made of polyimide, and the base material of the sliding sheet may be made of another heat-resistant resin. Further, the base material of the endless belt may be made of another heat-resistant resin, and the base material of the sliding sheet may be made of polyimide.

Further, the base material of the endless belt 130 and the base material of the sliding sheet 150 may both be configured to be non-polyimide.

In the above embodiment, the facing surface 151 of the sliding sheet 150 is formed in an uneven shape in which the sides of a plurality of squares are ridges, but the present invention is not limited to this, and is a rectangle, a parallelogram, or a quadrangle. Other than that, it may be a polygon. For example, the facing surface of the sliding sheet may be formed in an uneven shape having a plurality of hexagonal sides as ridges. Further, the facing surface of the sliding sheet may be formed in an uneven shape in which the sides of a plurality of triangles are ridges.

Each element described in the above-described embodiment and modification may be arbitrarily combined and carried out.

82 Pressurizing unit 130 Endless belt 131 Inner peripheral surface 140 Holder 150 Sliding sheet 151 Facing surface 152 Contact part 153 Recess 154 Groove 154A 1st groove 154B 2nd groove DI dispenser GR Grease NZ Nozzle P Pressurizing pad P1 1st pressurization Pad P2 2nd pressure pad

Claims (12)

With an endless belt,
A sliding sheet in contact with the inner peripheral surface of the endless belt and
A pressure pad that sandwiches the sliding sheet between the endless belt and the first pressure pad, and a second pressure pad arranged apart from the first pressure pad in the circumferential direction of the endless belt. With a pad, with a pressure pad,
Grease located between the endless belt and the sliding sheet,
It is a manufacturing method of a pressurizing unit provided with
A nozzle capable of discharging the grease from the tip is inserted between the endless belt and the sliding sheet, and between the first pressure pad and the second pressure pad in the circumferential direction.
A method for manufacturing a pressurizing unit, which comprises inserting the nozzle and then discharging the grease while pulling out the nozzle. Before inserting the nozzle between the endless belt and the sliding sheet, the endless belt covering the sliding sheet is moved in the width direction of the endless belt to expose the sliding sheet. The method for manufacturing a pressurizing unit according to claim 1, wherein the nozzle is inserted between the endless belt and the sliding sheet. Claim 1 is characterized in that when the nozzle is inserted between the endless belt and the sliding sheet, the nozzle is brought into contact with the outer peripheral surface of the sliding sheet and is inserted while being pressed against the sliding sheet. Alternatively, the method for manufacturing a pressurizing unit according to claim 2. The method for manufacturing a pressure unit according to any one of claims 1 to 3, wherein the dimension of the endless belt is larger than the dimension of the sliding sheet in the width direction of the endless belt. In the width direction of the endless belt, the size of the pressure pad is smaller than the size of the sliding sheet.
It is characterized in that, in the width direction, the grease is discharged from the nozzle in a range wider than the range in which the pressure pad is arranged and narrower than the range in which the sliding sheet is arranged. The method for manufacturing a pressurizing unit according to any one of claims 1 to 4. After the discharge of the grease is completed, the nozzle is reciprocated in the width direction of the endless belt while the tip of the nozzle is between the endless belt and the sliding sheet, and then the endless belt and the said. The method for manufacturing a pressurizing unit according to claim 5, wherein the pressure unit is pulled out from between the sliding sheets. The second pressure pad is
It is arranged downstream of the first pressure pad in the rotation direction of the endless belt.
The method for manufacturing a pressure unit according to any one of claims 1 to 6, wherein the durometer hardness is higher than that of the first pressure pad. The production of the pressurizing unit according to any one of claims 1 to 7, wherein a constant amount of grease is discharged from the nozzle with respect to the amount of movement of the endless belt in the width direction. Method. The method for manufacturing a pressurizing unit according to any one of claims 1 to 8, wherein the endless belt is rotated while being heated after the discharge of the grease is completed and the nozzle is pulled out. .. The facing surface of the sliding sheet facing the inner peripheral surface of the endless belt has a contact portion that contacts the endless belt and a plurality of recesses that are recessed from the contact portion and do not contact the endless belt. The method for manufacturing a pressurizing unit according to any one of claims 1 to 9, wherein the pressurizing unit is manufactured. The method for manufacturing a pressure unit according to any one of claims 1 to 10, wherein the base material of the endless belt and the base material of the sliding sheet are polyimide. The method for producing a pressure unit according to any one of claims 1 to 11, wherein the grease contains polytetrafluoroethylene as a thickener in a base oil containing perfluoropolyether. ..

Images