JP5549490B2 - Coating film forming device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating film forming apparatus for forming a coating film by applying a paint to a cylindrical outer peripheral surface of an object to be coated, for example, PPC (plain paper copying machine), LBP (laser beam printer), facsimile, etc. In an image forming apparatus employing the electrophotographic method, a coating film forming apparatus suitable for forming an elastic layer of a fixing member (fixing belt, fixing roller) for fixing an unfixed toner image on a recording paper by heating and pressing About .

  In an image forming apparatus such as a copying machine and a printer based on the principle of electrophotography, the toner image is passed through a recording sheet on which a toner image is transferred between a heated fixing member and a pressure member pressed against the fixing member. The toner is melted and fixed on the recording paper. Fixing members such as fixing belts and fixing rollers used in this fixing process are cylindrical cored bars made of aluminum, iron, etc., endless bases made of resin such as polyimide or metal such as Ni, etc. Obtained by applying a primer (adhesive) to the outer peripheral surface of, and applying a coating containing heat-resistant rubber such as silicone rubber on the outer surface to form an elastic layer having a thickness of about 100 to 300 μm. It is done.

  It is generally known that the elastic layer improves the granularity of the image by making the pressure for pressing the toner against the recording paper uniform in the fixing process described above. In addition, the thickness of the elastic layer affects the fixed image quality and affects the rise time (time to reach a predetermined temperature) of the fixing member. Therefore, the thickness of the elastic layer is required to be uniform. It has been.

  And as a method of forming the elastic layer described above, conventionally, a spray coating method or a dip coating method has been used. Since these methods control the film thickness by diluting the paint with a solvent and lowering the viscosity, the load on the environment is large. On the other hand, an annular curtain coating method (see, for example, Patent Document 1) can be given.

  In this annular curtain coating method, as illustrated in FIG. 19, a coating material is directly supplied from an annular coating nozzle 71 to the outer peripheral surface of the object to be coated 70, and the coating nozzle 71 is axially directed to the object to be coated 70. In order to perform the coating by moving the coating material, the coating material only needs to be supplied to the object to be coated 70, and there is no need to dilute with a solvent. However, in order to form a coating film with uniform thickness, it is required to hold an object to be coated such as a cylindrical cored bar or an endless substrate in a perfect circle, and the coating nozzle 71 It is necessary to make the gap between the outer periphery of the object 70 and the outer peripheral surface of the object 70 uniform.

  Therefore, conventionally, the object to be coated 70 is held on the outer periphery of the columnar support member, or the object to be painted is floated on the outer periphery of the support member 72 by gas, and the application nozzle. 71 is moved along the axis of the support member 72. However, when the outer diameter of the object to be coated 70 is increased, the coating nozzle 71 becomes large and heavy, and it becomes difficult to move the coating nozzle 71 along the axial center with high accuracy, thereby ensuring accuracy. However, it is necessary to increase the accuracy and rigidity of the entire apparatus, which greatly increases the cost and tends to increase the adjustment time until the work starts.

  For this reason, in the coating film forming apparatus shown in Patent Document 1, a large and heavy coating nozzle is fixed, and the object to be coated centered by being fitted to the outer periphery of a cylindrical support member is supported. It has been moved along the axis of the member. In the coating film forming apparatus shown in Patent Document 1, the entire length of the support member is about the total length of the object to be coated in order to fit the object to be coated on the outer periphery of the support member and position the object to be coated. It is about twice.

  However, since the inner diameter of the object to be coated is generally not uniform in the axial direction, the above-described coating film forming apparatus disclosed in Patent Document 1 has a large frictional force between the support member and the object to be coated. Thus, it becomes difficult to move the object to be coated at a constant speed. In addition, as shown in FIG. 19, a space is provided between the support member 72 and the object to be coated 70, and a pressurized gas is supplied into the space, whereby the object to be coated is formed on the outer peripheral surface of the support member 72. Although it is also described that the object 70 is slid, since the support member 72 has a total length that is approximately twice the total length of the object to be coated 70, The space between the object to be coated 70, that is, the length of the flow path until the pressurized gas is released to the atmosphere, changes, and the position of the object to be coated 70 changes, so that the support member 72 and the object to be coated are changed. The pressure in the space with 70 fluctuates. For this reason, it is difficult to always keep the distance between the outer peripheral surface of the object to be coated 70 and the application nozzle 71 constant.

The present invention aims to solve the above problems. That is, the present invention provides a coating film forming apparatus that can keep the distance between the outer peripheral surface of the object to be coated and the coating nozzle constant while allowing the object to be moved at a constant speed. for the purpose of Rukoto Kyosu.

  In order to solve the above problems and achieve the object, a coating film forming apparatus according to the present invention includes a support member that passes through a cylindrical object to be coated, and an outer peripheral surface of the object to be coated. An upper end of the support member in the coating film forming apparatus, comprising: an application nozzle for applying a paint; and a moving unit that moves the object to be coated relative to the application nozzle along an axis of the object to be coated. The portion is provided with a jet port for jetting gas toward the inner peripheral surface of the object to be coated, and a discharge port for discharging the paint of the coating nozzle is opposed to the upper end portion of the support member. It is characterized by being provided.

  A coating film forming apparatus according to a second aspect of the present invention is the coating film forming apparatus according to the first aspect, wherein the nozzles are provided at equal intervals in the circumferential direction of the support member. It is a feature.

  A coating film forming apparatus according to a third aspect of the present invention is the coating film forming apparatus according to the first or second aspect, wherein an exhaust port penetrating the support member is provided below the ejection port. It is characterized by having.

  A coating film forming apparatus according to a fourth aspect of the present invention is the coating film forming apparatus according to any one of the first to third aspects, wherein the support member is passed inside and the inner diameter is the same. It is formed smaller than the outer diameter of the object to be coated and larger than the outer diameter of the support member, and the object to be coated is placed on the end surface and moved along the axis of the support member by the moving means. Accordingly, a moving support member for moving the member to be coated relative to the application nozzle is provided.

  A coating film forming apparatus according to a fifth aspect of the present invention is the coating film forming apparatus according to the fourth aspect, in which a second jet that jets gas toward the outer peripheral surface of the supporting member on the movable supporting member. It is characterized by an exit.

  A coating film forming apparatus according to a sixth aspect of the present invention is the coating film forming apparatus according to the fifth aspect, wherein a second exhaust port is provided between the end face and the second jet port. It is characterized by that.

  A coating film forming apparatus according to a seventh aspect of the present invention is the coating film forming apparatus according to any one of the first to sixth aspects, wherein the support member is passed through the inside. Measuring means capable of measuring the outer diameter of the coated object, changing means capable of changing the pressure of the gas supplied into the jet port, and changing the gas pressure to the changing means according to the outer diameter of the object to be coated It is characterized by having a control means for making it possible.

  According to the first aspect of the present invention, since the pressurized gas is ejected toward the inner peripheral surface of the workpiece through which the support member is passed inward through the jet port, on the outer peripheral surface of the support member Thus, the object to be coated is floated, and the object to be coated can be easily and surely moved at a constant speed.

  In addition, since the ejection port for ejecting gas toward the inner peripheral surface of the object to be coated is provided at the upper end of the support member, the total length of the support member is much shorter than twice the entire length of the object to be painted. The total length of the support member can be made substantially equal to the total length of the object to be coated. For this reason, since the flow path until the gas ejected from the ejection port is opened to the atmosphere is always a space between the ejection port and the upper end of the support member, the support is supported even if the position of the object to be coated changes. The pressure in the space between the outer peripheral surface of the member and the base does not fluctuate. Therefore, the distance between the outer peripheral surface of the object to be coated and the application nozzle can be kept constant, and a coating film having no variation in thickness can be formed.

  According to the second aspect of the present invention, since the ejection ports are provided in the support member at equal intervals in the circumferential direction, the pressure in the space between the outer peripheral surface of the support member and the object to be coated is in the circumferential direction. It will be even. Therefore, the distance between the outer peripheral surface of the object to be coated and the application nozzle can be always constant.

  According to the third aspect of the present invention, since the exhaust port is provided below the ejection port, the gas ejected from the ejection port is exhausted from between the support member and the object to be coated through the exhaust port. The For this reason, it can prevent that the pressure of the space between a supporting member and a to-be-coated object becomes high too much. Therefore, the distance between the outer peripheral surface of the object to be coated and the application nozzle can be kept constant, and a coating film having no variation in thickness can be formed.

  According to the fourth aspect of the present invention, the object to be coated is stacked on the end surface of the moving support member whose inner diameter is smaller than the outer diameter of the object to be coated and larger than the outer diameter of the support member. By moving the support member, the object to be coated can be moved smoothly. Therefore, the object to be coated can be easily and reliably moved at a constant speed by moving the movable support member at a constant speed.

  According to the fifth aspect of the present invention, since the second jet port for ejecting gas toward the outer peripheral surface of the support member is provided on the inner peripheral surface of the movable support member, the gas is passed through the second jet port. By ejecting, the moving support member and the support member can be kept coaxial.

  According to the sixth aspect of the present invention, since the second exhaust port is provided between the end face and the second ejection port, the gas ejected from the second ejection port moves through the second exhaust port. It exhausts from between a support member and a support member. For this reason, it can prevent that the gas spouted inside the movement support member penetrate | invades between a support member and a to-be-coated object, and the pressure of the space between the said support member and to-be-coated object becomes too high. Can be prevented. Therefore, the distance between the outer peripheral surface of the object to be coated and the application nozzle can be kept constant, and a coating film having no variation in thickness can be formed.

  According to the seventh aspect of the present invention, the pressure of the gas supplied between the support member and the object to be coated through the ejection port according to the outer diameter of the object to be coated measured by the measuring means by the control means. change. For this reason, the pressure of the gas supplied between a support member and a to-be-coated object through a jet nozzle can be changed so that the outer diameter of to-be-coated object may become constant. Therefore, the distance between the outer peripheral surface of the object to be coated and the application nozzle can be kept constant, and a coating film having no variation in thickness can be formed.

  According to the present invention described in claim 8, a coating film having no variation in thickness can be obtained.

  According to the ninth aspect of the present invention, since the electrophotographic fixing member having a coating film with no variation in thickness is provided, an image forming apparatus with high image quality can be provided.

It is sectional drawing which shows the structure of the outline of the coating-film formation apparatus which concerns on the 1st Embodiment of this invention. It is sectional drawing which expands and shows the II section in FIG. It is sectional drawing of the principal part which shows the state which the coating-film formation apparatus shown by FIG. 1 has applied the coating material to the outer peripheral surface of a base | substrate. It is sectional drawing of the principal part which shows the state in which the coating-film formation apparatus shown by FIG. 3 has applied the coating material to the outer peripheral surface of a base | substrate with a large internal diameter. It is sectional drawing of the principal part which shows the state which the coating-film formation apparatus shown by FIG. 3 has applied the coating material to the outer peripheral surface of a base | substrate with a small internal diameter. FIG. 2 is a perspective view of a fixing belt obtained by forming a coating film with the coating film forming apparatus shown in FIG. 1. It is sectional drawing which follows the VII-VII line in FIG. FIG. 7 is a cross-sectional view illustrating an image forming apparatus including the fixing belt illustrated in FIG. 6. It is explanatory drawing which shows the flow of Couette Poiseuille between parallel plates. It is sectional drawing of the mandrel and base | substrate of the coating-film formation apparatus shown by FIG. It is sectional drawing which shows the schematic structure of the coating-film formation apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the principal part which shows the state which the coating-film formation apparatus shown by FIG. 11 has applied the coating material to the outer peripheral surface of a base | substrate. It is sectional drawing which shows the schematic structure of the coating-film formation apparatus which concerns on the 3rd Embodiment of this invention. It is explanatory drawing which shows the internal diameter of the base | substrate attached to the coating-film formation apparatus of this invention product. It is explanatory drawing which shows the position of the outer peripheral surface of a base | substrate when this invention 1 thru | or this invention product 3 and the base | substrate attached to the coating-film formation apparatus of a comparative example are moved. (A) is sectional drawing which shows the state which the coating head of the coating-film formation apparatus of this invention product 1 faced the upper end part of a base | substrate, (b) is a coating head of the coating-film formation apparatus of this invention product 1 to a base | substrate. It is sectional drawing which shows the state facing the lower end part of this, (c) is sectional drawing which shows the state by which the coating head of the coating-film formation apparatus of this invention product 1 was located below the jet nozzle. It is explanatory drawing which shows the dispersion | variation in the position of the outer surface of a base | substrate with respect to the deviation of the internal diameter of the base | substrate attached to this invention 1 thru | or this invention product 3, and the coating-film formation apparatus of a comparative example. It is explanatory drawing which shows the dispersion | variation in the thickness of the coating film with respect to the deviation of the internal diameter of the base | substrate attached to this invention product thru | or this invention product 3, the coating-film formation apparatus of a comparative example. It is sectional drawing which shows the schematic structure of the conventional coating-film formation apparatus.

  FIG. 1 is a cross-sectional view showing a schematic configuration of a coating film forming apparatus according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a portion II in FIG. 3 to 5 are cross-sectional views of main parts showing a state in which the coating film forming apparatus shown in FIG. FIG. 6 is a perspective view of a fixing belt (fixing member) obtained by forming the elastic layer 5 with the coating film forming apparatus shown in FIG. FIG. 7 is a sectional view taken along line VII-VII in FIG.

  A coating film forming apparatus 1 shown in FIG. 1 is a paint that forms an elastic layer 5 on a base 4 of a fixing belt 2 as an electrophotographic fixing member constituting an image forming apparatus 101 (shown in FIG. 8) such as a copying machine. 7 is an apparatus for forming a coating film 8 by coating 7.

  The fixing belt 2 is used as an electrophotographic fixing member for fixing a toner image on a recording paper 107 (shown in FIG. 8), and is formed in a cylindrical shape (endless tubular shape) as shown in FIG. . As shown in FIG. 7, the fixing belt 2 is composed of a base 4 made of a synthetic resin such as polyimide and formed in a cylindrical shape, a primer (adhesive) layer 3, and a heat-resistant rubber such as silicone rubber. The elastic layer 5, the primer layer 3, and the release layer 6 made of a fluororesin are laminated in order. The elastic layer 5 has a thickness of about 100 to 300 μm, and the combined thickness of the base 4 and the primer layer 3 is about 110 μm.

  Further, the elastic layer 5 is formed from one end portion (upper end portion when the paint 7 is applied by the coating film forming apparatus 1) 4a in the direction of the axis P of the base body 4 (indicated by a one-dot chain line in FIG. 1). 4 is formed over the other end portion 4b in the axis P direction (the lower end portion when the paint 7 is applied by the coating film forming apparatus 1) 4b. In the heated state, the fixing belt 2 presses the toner image against the recording paper 107 and fixes the toner image on the recording paper 107.

  The paint 7 is obtained by mixing silicone rubber and a known solvent, and the viscosity thereof is sufficiently larger than the viscosity of the paint used when forming the primer layer 3 and the release layer 6 described above. The paint 7 is applied to the outer surface of the substrate 4 (corresponding to the object to be coated in the claims) on which the primer layer 3 is formed by the coating film forming apparatus 1, that is, on the primer layer 3 described above. It is applied to form the elastic layer 5 described above.

  As shown in FIG. 1, the coating film forming apparatus 1 includes a paint supply unit 10 as a paint supply unit, a coating unit 11, a pressurized gas supply unit 12 as a pressurized gas supply unit, and a control as a control unit. Device 13. The paint supply unit 10 includes a unit main body 14 installed on a factory floor, a pipe 15, and the like. The unit body 14 includes a plurality of stock solution tanks, a plurality of pumps, a mixer, and the like.

  The unit main body 14 mixes the liquid that is the base of the above-described paint 7 in a plurality of stock solution tanks with a mixer, and sends the paint 7 obtained by the mixing by a pumping machine to the pipe 15. The pipe 15 connects the mixer of the unit main body 14 and a coating nozzle 19 described later included in the coating unit 11 to each other. The paint supply unit 10 supplies the paint 7 from the unit main body 14 into the application nozzle 19 via the pipe 15.

  The coating unit 11 includes a frame 17, a holding unit 18, and a coating nozzle 19. The frame 17 includes a base portion 21 installed on a factory floor, a plate-like extended plate portion 22 extending upward from an edge of the base portion 21, a plurality of nozzle support pillars 23, And a nozzle support table 24. The nozzle support column 23 is formed in a rod shape extending upward from the base portion 21, and its axis is provided in parallel to the vertical direction. In addition, the nozzle support pillars 23 are provided around a mandrel 25 to be described later at an interval. The nozzle support table 24 is formed in an annular shape, is attached to the upper end of the nozzle support column 23, and both surfaces thereof are provided in parallel with the horizontal direction.

  The holding unit 18 includes a mandrel 25 as a supporting member and a moving support unit 26 as a moving unit. The mandrel 25 is formed in a cylindrical shape and is erected upward from the upper surface of the base 21, and its axis is parallel to the vertical direction. The mandrel 25 is formed so that its outer diameter is slightly larger than the inner diameter of the base 4 in a state where it is not elastically deformed. This means that the base body 4 is expanded from the inside by the pressure of a gas layer composed of a gas ejected from a later-described jet outlet 28 of the mandrel 25, and the inner diameter of the base body 4 is made larger than the outer shape of the mandrel 25 by elastic deformation. This is because by slightly increasing the effect, the effect of reducing the influence of the inner diameter deviation of the substrate 4 to be described later can be obtained remarkably. The total length of the mandrel 25 is sufficiently shorter than twice the total length of the base 4 and slightly longer than the total length of the base 4 (substantially equal to the total length of the base 4). The mandrel 25 described above is passed through the base 4.

  The mandrel 25 is provided with a tapered surface 27 that tapers the mandrel 25 at its upper end. Note that the upper end of the mandrel 25 as a support member in the present invention is released from the gas supplied by the pressurized gas supply unit 12 and flowing between the outer peripheral surface of the mandrel 25 and the inner peripheral surface of the substrate 4 to the atmosphere. In this embodiment, it refers to the base portion 27a of the tapered surface 27 described above. An airtight chamber 46 is provided at the upper end of the mandrel 25 to keep the inside thereof airtight. Further, the mandrel 25 is provided with a plurality of jet outlets 28 communicating with the inside and outside of the hermetic chamber 46 at the upper end thereof and opening on the outer peripheral surface of the mandrel 25. The ejection port 28 is for ejecting the pressurized gas supplied by the pressurized gas supply unit 12 toward the inner peripheral surface of the base body 4 through which the mandrel 25 is passed. The plurality of jet nozzles 28 are provided at equal intervals in the circumferential direction of the mandrel 25.

  The movement support unit 26 includes a linear actuator 29, a support plate 30, a movement support member 31, and a linear encoder (not shown). The linear actuator 29 includes a stator 32 that is attached to the extending plate portion 22 and extends linearly in the vertical direction, and a movable element 33 that is movable along the longitudinal direction of the stator 32. It has.

  The support plate 30 includes a flat main body portion 34 and an annular ring portion 35 attached to the main body portion 34. The main body 34 is provided with its upper and lower surfaces parallel to the horizontal direction. One end of the main body 34 is attached to the mover 33 of the linear actuator 29. The annular portion 35 is formed in an annular shape whose inner diameter is sufficiently larger than the outer diameter of the mandrel 25. The annular portion 35 passes through the mandrel 25 inside thereof, and is attached to the other end portion of the main body portion 34 on the side away from the linear actuator 29. The annular portion 35 is provided coaxially with the mandrel 25. A ball roller 36 is placed on the surface of the annular portion 35.

  As shown in FIG. 2, the moving support member 31 is formed in a thick annular shape having an inner diameter larger than the outer diameter of the mandrel 25 and smaller than the outer diameter of the base body 4 on which the primer layer 3 is formed. The movement support portion 26 is arranged on the ball roller 36, that is, on the annular portion 35 of the support plate 30 via the ball roller 36 with the mandrel 25 passed therethrough. Further, the movement support member 31 is formed in a taper shape such that the movement support member 31 gradually tapers as the end surface 31a located above the movement support member 31 moves upward. The movement support member 31 is provided with a recessed space 37 that is recessed from the inner peripheral surface thereof, and a partition wall 38 that partitions the recessed space 37 up and down. The lower end 4b of the base 4 is placed on the end surface 31a of the moving support member 31.

  Further, as shown in FIG. 2, the movement support member 31 is provided with a plurality of second ejection ports 39 and second exhaust ports 40. The second ejection port 39 and the second exhaust port 40 penetrate the outer wall of the movement support member 31 and are provided at equal intervals in the circumferential direction of the movement support member 31. The second spout 39 communicates the outside of the movement support member 31 and the lower space 37 a of the two spaces 37 a and 37 b partitioned by the partition wall 38 of the recessed space 37.

  The 2nd jet nozzle 39 spouts the pressurized gas supplied by the pressurized gas supply part 12 toward the outer peripheral surface of the mandrel 25 through the space 37a mentioned above. The pressurized gas ejected from the second ejection port 39 is filled in the space 37a described above, attempts to get over the partition wall 38 and enter the space 37b. It tries to leak out of the movable support member 31 from between. At this time, the moving support member 31 is positioned at a position coaxial with the mandrel 25 by the pressure of the gas supplied from the pressurized gas supply unit 12 described above, and the base 4 on the end surface 31a of the moving support member 31 is moved to the mandrel. Position at a position coaxial with 25. The second exhaust port 40 communicates the outside of the movement support member 31 and the upper space 37 b of the two spaces 37 a and 37 b partitioned by the partition wall 38 of the recessed space 37. That is, the second exhaust port 40 is provided between the end surface 31 a of the movement support member 31 and the second jet port 39. The second exhaust port 40 exhausts the pressurized gas that has entered the space 37 b described above to the outside of the moving support member 31. The second exhaust port 40 is configured so that the opening is made as large as possible to reduce the flow velocity of the exhausted gas, and the pressure of the exhausted gas immediately becomes equal to the pressure of the surrounding atmosphere.

  The linear encoder detects the position of the moving support member 31. The linear encoder outputs the detected position of the moving support member 31 toward the control device 13.

  As described above, the holding unit 18 holds the base body 4 as an object to be coated by passing the mandrel 25 through the base body 4 and overlapping the base body 4 on the end surface 31 a of the moving support member 31. In addition, the movement support unit 26, that is, the holding unit 18 moves the moving element 33 of the linear actuator 29 in the vertical direction, so that the base body 4 stacked on the end surface 31 a of the movement support member 31 is moved to the axis P of the base body 4. Is moved along the vertical direction. In this way, the movement support part 26 moves the base 4 relative to the coating nozzle 19 along the axis P of the base 4.

  As shown in FIG. 1, the application nozzle 19 is formed in a hollow annular shape. A pipe 15 is connected to the coating nozzle 19, and the paint 7 is supplied from the pipe 15, that is, the above-described paint supply unit 10 to the space inside thereof. It is desirable that a plurality of pipes 15 are connected at intervals in the circumferential direction of the application nozzle 19 in order to reduce non-uniform pressure distribution due to the supply of the coating material 7 into the application nozzle 19. The application nozzle 19 is fixed on the nozzle support table 24 in a state where the mandrel 25 is passed inside. The application nozzle 19 is disposed coaxially with the mandrel 25 and the base body 4 through which the mandrel 25 is passed, and the inner peripheral surface thereof is provided at a position facing the upper end of the mandrel 25 with a gap. ing. Further, the inner diameter of the application nozzle 19 is larger than the outer diameter of the base body 4 through which the mandrel 25 is passed. That is, the inner peripheral surface 41 of the coating nozzle 19 is opposed to the outer peripheral surface 4c of the base 4 (the outer surface of the primer layer 3) with a gap CG, and is coaxial with the base 4 held by the holding portion 18. Has been placed.

  A coating slit 19 b serving as a discharge port that communicates the inside and outside of the coating nozzle 19 is formed on the inner peripheral surface 41 of the coating nozzle 19 over the entire circumference of the coating nozzle 19. The coating slit 19 b is provided between the base portion 27 a of the tapered surface 27 serving as the upper end of the mandrel 25 in the axial direction of the mandrel 25 and the ejection port 28. Thus, the coating slit 19 b is provided at a position facing the upper end portion of the mandrel 25.

  The coating nozzle 19 discharges the coating material 7 supplied from the coating material supply unit 10 through the coating slit 19b in the horizontal direction toward the outer peripheral surface 4c of the base body 4 through which the mandrel 25 of the holding unit 18 is passed. At this time, the paint 7 is uniformly discharged from the entire circumference of the coating slit 19b, and the discharged paint 7 forms a conical paint film. In the present specification, a conical coating film that is discharged from the coating slit 19b and adheres to the outer peripheral surface 4c of the substrate 4 is referred to as a “curtain film”.

  The pressurized gas supply unit 12 includes a pressurized gas supply source (not shown), a pair of pipes 42a and 42b connected to the pressurized base supply source and branched in the middle, and changes provided in the pipes 42a and 42b, respectively. Regulators 43a and 43b and valves 44a and 44b are provided as means. The pressurized gas supply source is composed of a blower such as a tank or a compressor filled with pressurized gas. The pressurized gas supply source supplies pressurized gas to the pipes 42a and 42b.

  One of the pipes 42a and 42b passes through the lower end portion of the mandrel 25 and is connected to the above-described airtight chamber 46 to supply the pressurized gas supplied from the pressurized gas supply source to the airtight chamber. 46 is supplied into the nozzle 28. The other pipe 42 b is connected to a second jet 39 provided in the movement support member 31, and pressurized gas supplied from a pressurized gas supply source is placed in a space 37 a below the recessed space 37. Supply.

  The regulators 43a and 43b can change the pressure of the gas in the pipes 42a and 42b, that is, the pressure of the gas supplied into the hermetic chamber 46 and the ejection port 28 and the pressure of the gas supplied into the recessed space 37 described above. is there. The valves 44 a and 44 b switch between blocking and opening the gas supply into the hermetic chamber 46 and the jet outlet 28 and blocking and opening the gas supply into the recessed space 37 described above.

  The pressurized gas supply unit 12 guides the pressurized gas from the pressurized gas supply source to the ejection port 28 and ejects the gas between the outer circumferential surface of the mandrel 25 and the inner circumferential surface of the base body 4 through the ejection port 28. Then, the pressurized gas from the pressurized gas supply source is guided to the second ejection port 39 and is ejected between the outer peripheral surface of the mandrel 25 and the moving support member 31 through the second ejection port 39. Moreover, the pressurized gas supply part 12 can change the pressure of the gas supplied in the jet nozzles 28 and 39 mentioned above.

  The control device 13 is a computer having a known RAM, ROM, CPU and the like. The control device 13 is connected to the paint supply unit 10, the application unit 11, and the pressurized gas supply unit 12, and controls them to control the entire coating film forming apparatus 1. That is, the control device 13 receives information from the linear encoder of the movement support unit 26 of the holding unit 18 and moves the holding unit 18 based on information according to the position of the coating nozzle 19 from the linear encoder. The operation of the linear actuator 29 of the support portion 26, the regulators 43a and 43b and valves 44a and 44b of the pressurized gas supply portion 12, the pumping pump of the unit main body 14 of the paint supply unit 10 and the like are controlled to control the application nozzle 19. The coating 7 is applied to the outer peripheral surface 4 c of the base 4 while moving along the axis P to form the coating film 8, that is, the elastic layer 5.

  The coating film forming apparatus 1 according to the embodiment described above forms the coating film 8, that is, the elastic layer 5 as follows. First, the movement support member 31 of the movement support part 26 of the holding part 18 is positioned at the lowest position. Then, the base 4 is placed on the mandrel 25 so that the lower end 4 b overlaps the end surface 31 a of the moving support member 31, and the mandrel 25 is passed through the base 4. Then, in the coating film forming apparatus 1, the control device 13 opens the valves 44 a and 44 b to eject the gas pressurized from the pressurized gas supply unit from the ejection port 28 and the second ejection port 39.

  Then, as shown in FIG. 3, an air layer is formed between the inner peripheral surface of the base 4 and the mandrel 25 by the gas ejected from the ejection port 28, and these are kept coaxial with each other and come into contact with each other. Absent. Further, as shown in FIG. 3, an air layer is formed between the mandrel 25 and the moving support member 31 by the gas ejected from the second ejection port 39, and these are maintained coaxially and in contact with each other. There is no.

  Then, the control device 13 starts supplying the paint 7 from the paint supply unit 10 to the application nozzle 19 and moves the moving element 33 of the linear actuator 29 upward at a constant speed. By the movement of the moving support member 31, that is, the base 4, the paint 7 adheres to the outer peripheral surface 4 c of the base 4, and the coating film 8 is formed on the outer peripheral surface 4 c of the base 4. When the movable support member 31 is positioned at the uppermost position and the coating film 8 is formed over substantially the entire length of the base body 4, the control device 13 supplies the paint 7 from the paint supply unit 10 to the application nozzle 19. And the moving element 33 of the linear actuator 29 is stopped. Then, the substrate 4 on which the coating film 8 is formed is removed from the moving support member 31. In the next step, the coating layer 8 is cured by vulcanization (heating) to form the elastic layer 5. By repeating the above-described steps, the elastic layer 5 is formed on the new substrate 4.

  The gas flow when forming the coating film 8 will be described below. The pressurized gas supplied into the hermetic chamber 46 is ejected toward the inner peripheral surface of the substrate 4 through the ejection port 28. And since the spout 28 is provided in the upper end part of the mandrel 25, the gas spouted from the spout 28 is made into the outer peripheral surface of the mandrel 25 and the internal peripheral surface of the base | substrate 4 along the arrow in FIG. Then, the air is released from the base 27 a of the tapered surface 27, that is, the base 27 a as the upper end of the mandrel 25. As described above, since the ejection port 28 is provided at the upper end portion of the mandrel 25, even if the base body 4 moves upward due to the progress of the formation of the coating film 8, the tapered surface 27 extends from the ejection port 28 described above. The length of the gas flow path reaching the base 27a, that is, the upper end of the mandrel 25 does not vary. For this reason, the pressure in the space between the mandrel 25 and the base body 4 does not change even when the base body 4 moves, and the base body 4 always passes through a substantially constant range with respect to the mandrel 25.

  Even if the inner diameter of the base 4 varies, the pressure in the space between the mandrel 25 and the base 4 is exhausted from between the base portion 27 a of the tapered surface 27 as the upper end of the mandrel 25 and the inner peripheral surface of the base 4. The base body 4 always passes through a substantially constant range with respect to the mandrel 25 because the flow rate varies depending on the flow rate of the gas to be produced. Specifically, when the inner diameter of the base body 4 is large, as shown in FIG. 4, the base body 4 swells due to the pressure of the gas ejected from the ejection port 28, and the tapered surface 27 serving as the upper end of the mandrel 25 The flow rate of the gas exhausted from between the base portion 27a and the inner peripheral surface of the base 4 increases.

  As a result, the pressure in the space between the mandrel 25 and the base 4 becomes relatively low, and the swelling of the base 4 is suppressed. In addition, when the inner diameter of the base 4 is small, as shown in FIG. 5, the base 4 swells due to the pressure of the gas ejected from the jet outlet 28, and the base 27 a of the tapered surface 27 serving as the upper end of the mandrel 25 The flow rate of the gas exhausted from the space between the inner peripheral surface of the base 4 is reduced. As a result, the pressure in the space between the mandrel 25 and the base 4 becomes relatively high, and the swelling of the base 4 is increased. Thus, even if the inner diameter of the base body 4 varies, the base body 4 always passes through a substantially constant range with respect to the mandrel 25, and the base body 4 has a large inner diameter or a small base diameter 4. Always passes within a substantially constant range with respect to the mandrel 25.

  This means that the following formula 1 (the formula showing the Couette-Poiseuille flow between the parallel plates that can be derived by the Naviestokes formula), formula 2 (the formula of the tension in the circumferential direction of the base 4) and formula 3 (the base 4) The base 27a of the tapered surface 27 as the upper end of the mandrel 25 and the base 4 are made constant with the pressure of the pressurized gas supplied from the pressurized gas supply unit 12 constant. Since the flow rate of the gas exhausted from between the inner peripheral surface and the pressure of the space between the mandrel 25 and the base body 4 is inversely proportional, the position of the outer peripheral face 4c of the base body 4 is expressed by Equation 4 below. The relationship between the change amount ΔG and the change amount ΔD of the inner diameter of the substrate 4 can be obtained.

  However, ΔG: Displacement amount of the outer peripheral surface 4c of the base body 4, ΔD: Displacement amount of the inner diameter of the base body 4, D: Inner diameter of the base body 4, μ: Viscosity coefficient of gas, L: Length of the flow path (from the jet port 28) Length of the taper surface 27 to the base 27a), δ: Young's modulus of the substrate 4, i: coefficient, Q: flow rate of the gas ejected from the ejection port 28, P: pressure of the gas ejected from the ejection port 28, T: The tension of the substrate 4 is used.

  That is, according to Equation 4, the displacement amount ΔG of the outer peripheral surface 4c of the base body 4 is a function of the 0.4th power of the displacement amount ΔD of the inner diameter of the base body 4, and the influence on ΔG increases as ΔD increases. Therefore, the variation in the position of the outer peripheral surface 4c of the base 4 can be kept within a small range with respect to the inner diameter of the base 4. Further, according to Equation 4, it has been clarified that the position of the outer peripheral surface 4c of the base 4 varies if the length L of the flow path does not become a constant value. As described above, with the configuration of the above-described embodiment, the distance between the outer peripheral surface 4c of the base 4 and the coating slit 19b of the coating nozzle 19 can be maintained at a constant distance with high accuracy. The coating film 8 having a thickness, that is, the elastic layer 5 can be formed.

  In addition, the above-mentioned Formula 1, Formula 2, Formula 3, and Formula 4 are calculated | required as follows. First, Equation 1 will be described. The flow of Couette Poiseuille between the parallel plates 200 shown in FIG. 9 derived by the Naviestokes equation, which is the equation of motion of the viscous fluid, is as follows, assuming that the length of the parallel plates 200 is L and the interval between the parallel plates 200 is 2b. This can be expressed by Equation 5.

  When the above formula 5 is applied to the coating film forming apparatus 1 of the present embodiment, the distance G = 2b between the outer peripheral surface of the mandrel 25 and the substrate 4, so the above formula 5 becomes the following formula 6.

  Here, since the pressure at the base portion 27a of the tapered surface 27 which is the upper end of the mandrel 25 is atmospheric pressure, ΔP = P−0 = P in the above equation 6, so that the above equation 6 becomes the above equation 1. .

  Next, Formula 2 will be described. In the cross section shown in FIG. 10, assuming that the change in tension of the base 4 is ΔT, the circumferential extension ΔX of the base 4 and the Young's modulus δ is the spring constant of the base 4, the circumferential tension of the base is as follows: It can be shown by Equation 7.

  Here, if the change in the distance between the outer peripheral surface of the mandrel 25 and the base 4 is ΔG and this ΔG is converted into the circumferential direction of the base 4, the following equation 8 is established from the relationship of the circumferential length of 2π × radius. To do.

  Substituting Equation 8 into Equation 7 yields Equation 2 above.

  Next, Formula 3 will be described. In the cross section shown in FIG. 10, the total sum of the forces applied to the inner peripheral surface of the base body 4 can be expressed by the length in the circumferential direction × pressure, and therefore can be expressed by PπD. Therefore, the following formula 9 is established. Therefore, the above formula 3 is obtained.

  Next, Formula 4 will be described. If ΔT is eliminated from Equation 2 and Equation 3, PπΔD = 2δπΔG is obtained, and Equation 10 below is obtained.

  Here, in the above-described embodiment, when the flow rate of the gas exhausted from between the mandrel 25 and the base 4, that is, the gas exhausted between the mandrel 25 and the base 4, increases between the mandrel 25 and the base 4. Therefore, if I is a constant, the flow rate Q and the pressure P are inversely proportional, and the following equation 11 is established.

  Substituting Equation 11 into Equation 1 yields Equation 12 below.

  When P is deleted from the above formula 10 and the above formula 12, the following formula 13 is obtained.

Here, since I is a constant, when (3I) ^0.2 = i (constant), the above equation 4 can be obtained.

  As described above, the fixing belt 2 on which the elastic layer 5 is formed constitutes the image forming apparatus 101 shown in FIG. The image forming apparatus 101 forms an image, that is, a color image of each color of yellow (Y), magenta (M), cyan (C), and black (K) on a recording sheet 107 as a single transfer material. Note that units corresponding to yellow, magenta, cyan, and black colors are denoted by Y, M, C, and K at the end of the reference numerals.

  As shown in FIG. 8, the image forming apparatus 101 includes an apparatus main body 102, a paper feed unit 103, a registration roller pair 110, a transfer unit 104, a fixing unit 105, and a plurality of laser writing units 122Y, 122M, and 122C. , 122K and a plurality of process cartridges 106Y, 106M, 106C, 106K.

  The apparatus main body 102 is formed in a box shape, for example, and is installed on a floor or the like. The apparatus main body 102 includes a paper feed unit 103, a registration roller pair 110, a transfer unit 104, a fixing unit 105, a plurality of laser writing units 122Y, 122M, 122C, and 122K, and a plurality of process cartridges 106Y, 106M, and 106C. , 106K.

  A plurality of paper feed units 103 are provided in the lower part of the apparatus main body 102. The paper feed unit 103 includes a paper feed cassette 123 that can accommodate the above-described recording paper 107 in a stacked manner and can be taken in and out of the apparatus main body 102, and a paper feed roller 124. The paper feed roller 124 is pressed against the uppermost recording paper 107 in the paper feed cassette 123. The paper feed roller 124 sends out the uppermost recording paper 107 between the transfer belt 129 (to be described later) of the transfer unit 104 and the photosensitive drums included in the process cartridges 106Y, 106M, 106C, and 106K.

  The registration roller pair 110 is provided in a conveyance path of the recording paper 107 conveyed from the paper supply unit 103 to the transfer unit 104, and includes a pair of rollers 110a and 110b. The registration roller pair 110 sandwiches the recording paper 107 between the pair of rollers 110a and 110b, and the transfer unit 104 and the process cartridges 106Y, 106M, 106C, and 106K at a timing at which toner images can be superimposed on the sandwiched recording paper 107. Send between.

  The transfer unit 104 is provided above the paper feed unit 103. The transfer unit 104 includes a driving roller 127, a driven roller 128, a conveyance belt 129, and transfer rollers 130Y, 130M, 130C, and 130K. The drive roller 127 is disposed on the downstream side in the conveyance direction of the recording paper 107 and is driven to rotate by a motor or the like as a drive source. The driven roller 128 is rotatably supported by the apparatus main body 102 and is disposed on the upstream side in the conveyance direction of the recording paper 107. The conveyor belt 129 is formed in an endless annular shape and is stretched over both the driving roller 127 and the driven roller 128 described above. The conveyance belt 129 circulates (endless travel) around the driving roller 127 and the driven roller 128 described above in the counterclockwise direction in the drawing as the driving roller 127 is rotationally driven.

  The transfer rollers 130Y, 130M, 130C, and 130K sandwich the conveyance belt 129 and the recording paper 107 on the conveyance belt 129 between the photosensitive drums of the process cartridges 106Y, 106M, 106C, and 106K, respectively. In the transfer unit 104, the transfer rollers 130Y, 130M, 130C, and 130K press the recording paper 107 sent out from the paper feed unit 103 against the outer surface of the photosensitive drum of each process cartridge 106Y, 106M, 106C, and 106K, and thereby The toner image on the body drum is transferred to the recording paper 107. The transfer unit 104 sends the recording paper 107 onto which the toner image is transferred toward the fixing unit 105.

  The fixing unit 105 is provided downstream of the transfer unit 104 in the conveyance direction of the recording paper 107, and includes a pair of belts 2 and 2a that sandwich the recording paper 107 therebetween. This belt 2 is the above-described fixing belt 2 and constitutes an electrophotographic fixing member in the scope of claims. A pressure bell (pressure member) 2 a that the belt 2 a is in pressure contact with the fixing belt 2. The fixing unit 105 sandwiches the recording paper 107 sent out from the transfer unit 104 between the pair of belts 2 and 2 a and presses and heats the toner image transferred from the photosensitive drum 108 onto the recording paper 107. Then, it is fixed on the recording paper 107.

  The laser writing units 122Y, 122M, 122C, and 122K are attached to the upper part of the apparatus main body 102, respectively. The laser writing units 122Y, 122M, 122C, and 122K correspond to one process cartridge 106Y, 106M, 106C, and 106K, respectively. The laser writing units 122Y, 122M, 122C, and 122K irradiate the outer surface of the photosensitive drum uniformly charged by the charging roller included in the process cartridges 106Y, 106M, 106C, and 106K with laser light, thereby forming an electrostatic latent image. Form.

  The process cartridges 106Y, 106M, 106C, and 106K are provided between the transfer unit 104 and the laser writing units 122Y, 122M, 122C, and 122K, respectively. The process cartridges 106Y, 106M, 106C, and 106K are detachable from the apparatus main body 102. The process cartridges 106Y, 106M, 106C, and 106K are arranged side by side along the conveyance direction of the recording paper 107. The process cartridges 106Y, 106M, 106C, and 106K include a charging roller as a charging device, a photosensitive drum as an electrostatic latent image carrier, a cleaning blade as a cleaning device, and a developing device. Therefore, the image forming apparatus 101 includes at least a charging roller, a photosensitive drum, a cleaning blade, and a developing device.

  The image forming apparatus 101 forms an image on the recording paper 107 as described below. First, the image forming apparatus 101 rotates the photosensitive drum and uniformly charges the outer surface of the photosensitive drum by the charging roller. Laser light is irradiated on the outer surface of the photosensitive drum to form an electrostatic latent image on the outer surface of the photosensitive drum. When the electrostatic latent image is positioned in the development area, the developer adsorbed on the outer surface of the developing sleeve provided in the developing device is adsorbed on the outer surface of the photosensitive drum, and the electrostatic latent image is developed. Are formed on the outer surface of the photosensitive drum.

  In the image forming apparatus 101, the recording paper 107 conveyed by the paper supply roller 124 of the paper supply unit 103 is transferred to the photosensitive drums of the process cartridges 106Y, 106M, 106C, and 106K and the conveyance belt 129 of the transfer unit 104. The toner image formed on the outer surface of the photosensitive drum is transferred to the recording paper 107. The image forming apparatus 101 uses a fixing unit 105 to fix the toner image on the recording paper 107. Thus, the image forming apparatus 101 forms a color image on the recording paper 107.

  According to the present embodiment, since the pressurized gas is ejected toward the inner peripheral surface of the base body 4 through which the mandrel 25 is passed through the jet port 28, the base body 4 is floated on the outer peripheral surface of the mandrel 25. Thus, the substrate 4 can be easily and reliably moved at a constant speed.

  Further, since the ejection port 28 for ejecting gas toward the inner peripheral surface of the base body 4 is provided at the upper end portion of the mandrel 25, the total length of the mandrel 25 is much shorter than twice the total length of the base body 4. The total length of the mandrel 25 can be made substantially equal to the total length of the substrate 4. For this reason, the flow path until the gas ejected from the ejection port 28 is released to the atmosphere is always a space between the ejection port 28 and the base portion 27a of the tapered surface 27 as the upper end of the mandrel 25. Even if the position of 4 changes, the pressure in the space between the outer peripheral surface of the mandrel 25 and the base 4 does not fluctuate. Therefore, the distance between the outer peripheral surface 4c of the substrate 4 and the coating nozzle 19 can be made constant at all times, and the coating film 8, that is, the elastic layer 5 with no variation in thickness can be formed.

  Since the ejection ports 28 are provided in the mandrel 25 at equal intervals in the circumferential direction, the pressure in the space between the outer peripheral surface of the mandrel 25 and the base 4 is uniform in the circumferential direction. Therefore, the distance between the outer peripheral surface of the base body 4 and the coating nozzle 19 can be always constant.

  Since the base 4 is stacked on the end surface 31a of the moving support member 31 whose inner diameter is smaller than the outer diameter of the base 4 and larger than the outer diameter of the mandrel 25, the base 4 can be smoothly moved by moving the moving support member 31. Can be moved. Therefore, the base 4 can be easily and reliably moved at a constant speed by moving the movable support member 31 at a constant speed.

  Since the second ejection port 39 for ejecting gas toward the outer peripheral surface of the mandrel 25 is provided in the movement support member 31, by ejecting the gas through the second ejection port 39, the movement support member 31 and the mandrel 25 Can be kept coaxial.

  Since the second exhaust port 40 is provided between the end surface 31 a and the second jet port 39, the gas ejected from the second jet port 39 passes through the second exhaust port 40 to form the movement support member 31 and the mandrel 25. It is exhausted from between. For this reason, it can prevent that the gas spouted inside the movement support member 31 penetrate | invades between the mandrel 25 and the base | substrate 4, and prevents gas leaking from the clearance gap between the base | substrate 4 and the end surface 31a. And it can prevent that the other end part 4b of the base | substrate 4 spreads outside. Therefore, the distance between the outer peripheral surface 4c of the substrate 4 and the coating nozzle 19 can be made constant at all times, and the coating film 8, that is, the elastic layer 5 with no variation in thickness can be formed.

  In addition, according to the present embodiment, it is possible to obtain the fixing belt 2 having the coating film 8 that does not vary in thickness, that is, the elastic layer 5.

  Furthermore, since the image forming apparatus 101 includes the fixing belt 2 having the elastic layer 5 with no variation in thickness, high image quality can be obtained.

  Next, the coating film formation apparatus 1 concerning the 2nd Embodiment of this invention is demonstrated based on FIG.11 and FIG.12. The same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In the coating film forming apparatus 1 of the present embodiment, as shown in FIGS. 11 and 12, the airtight chamber 46 provided at the upper end of the mandrel 25 is formed with a larger diameter than the other parts of the mandrel 25. An exhaust port 47 is provided at both the upper and lower sides of the airtight chamber 46 and the upper end surface of the mandrel 25 at the upper end of the mandrel 25. The exhaust port 47 is a hole that communicates the inside and outside of the mandrel 25 (that is, penetrates the mandrel 25), and the exhaust port 47 that is provided both above and below the hermetic chamber 46 extends in the circumferential direction of the mandrel 25. An exhaust port 47 provided at an equal interval and provided at the upper end surface of the mandrel 25 is provided at the center of the upper end surface. That is, the exhaust port 47 is provided immediately below the jet port 28. In the present embodiment, an exhaust port 47 penetrating the mandrel 25 (communication between the inside and outside of the mandrel 25) is provided at the lower end portion of the mandrel 25.

  In the present embodiment, the gas jetted between the outer peripheral surface of the mandrel 25 and the inner peripheral surface of the base 4 from the jet port 28 flows as shown by the arrows in FIG. That is, the air is exhausted from between the mandrel 25 and the base body 4 to the outside thereof. Then, the gas is exhausted out of the mandrel 25 through the exhaust port 47.

  According to this embodiment, in addition to the effects of the first embodiment described above, the exhaust port 47 is provided below the jet port 28, so that the gas ejected from the jet port 28 passes through the exhaust port 47 and passes through the mandrel 25. And the base 4 are exhausted. For this reason, it can prevent that the pressure of the space between the mandrel 25 and the base | substrate 4 becomes high too much. Therefore, the distance between the outer peripheral surface 4c of the substrate 4 and the coating nozzle 19 can be made constant at all times, and the coating film 8, that is, the elastic layer 5 with no variation in thickness can be formed.

  Next, the coating film formation apparatus 1 concerning the 3rd Embodiment of this invention is demonstrated based on FIG. The same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 13, the coating film forming apparatus 1 according to the present embodiment includes a laser displacement meter 45 as a measuring unit. The laser displacement meter 45 is attached to the nozzle support table 24 in a state facing the upper end portion of the mandrel 25. The laser displacement meter 45 irradiates the laser toward the outer peripheral surface 4c of the base body 4 through which the mandrel 25 is passed, and receives the laser reflected from the outer peripheral surface 4c of the base body 4, whereby the laser displacement meter 45 is received. And the distance between the outer peripheral surface 4c of the substrate 4 is measured. The laser displacement meter 45 measures the outer diameter of the substrate 4 (information corresponding to the outer diameter) by measuring the distance from the upper end of the substrate 4. The laser displacement meter 45 outputs the measurement result to the control device 13.

  The control device 13 causes the regulator 43b to change the gas pressure according to the outer diameter of the base 4 measured by the laser displacement meter 45. Specifically, when the outer diameter of the substrate 4 measured by the laser displacement meter 45 is lower than a predetermined value, the gas pressure is increased in the regulator 43b, and the laser displacement meter 45 measured. If the outer diameter of the substrate 4 exceeds a predetermined value, the pressure of the gas is lowered in the regulator 43b so that the distance between the substrate 4 and the coating slit 19b is always constant at a predetermined value. The gas pressure is changed so that

  According to the present embodiment, in addition to the effects of the first embodiment described above, the control device 13 causes the mandrel 25, the substrate 4 and the substrate 4 to pass through the ejection port 28 according to the outer diameter of the substrate 4 measured by the laser displacement meter 45. The pressure of the gas supplied during the period is changed. For this reason, the pressure of the gas supplied between the mandrel 25 and the base body 4 through the ejection port 28 can be changed so that the outer diameter of the base body 4 becomes constant. Therefore, the distance between the outer peripheral surface 4c of the base 4 and the coating nozzle 19 can be always constant, and the coating film 8, that is, the elastic layer 5 with no variation in thickness can be reliably formed. Also in the present embodiment, the above-described ejection port 28 may be provided.

  In the above-described embodiment, the elastic layer 5 of the fixing belt 2 is formed. However, the present invention is not limited to the fixing belt 2, and a coating film is applied to various objects to be coated such as a fixing roller. Of course, it may be formed.

  Next, the inventors of the present invention confirmed the effect of the coating film forming apparatus 1 of the present invention. First, in the first experiment whose result is shown in FIG. 14, in the following product 1 of the present invention, the substrate 4 made of polyimide, having an inner diameter of 147.1 mm, a length of 420 mm, and a thickness of 110 μm has a viscosity of 20000 Pa · An s (pascal second) two-component mixed addition type thermosetting resin liquid silicone elastomer was applied as paint 7. The coating film 8 was formed so as to have a thickness of 200 ± 30 μm (thickness for obtaining good image quality required for the fixing belt 2) after vulcanization. In addition, after application | coating, 25 mm of each both ends of the base | substrate 4 are cut | disconnected, and the said base body 4 is made into 370 mm full length.

  In the product 1 of the present invention, in the coating film forming apparatus 1 of the first embodiment described above, the mandrel 25 having an outer diameter of 147.21 mm and a length of 560 mm is used, and the width provided at the upper end of the mandrel 25 is 2 mm. Sixteen outlets 28 having a diameter of 1 mm and having a diameter of 1 mm were formed at equal intervals in the circumferential direction. Further, the distance between the V groove and the base portion 27a of the tapered surface 27 as the upper end of the mandrel 25 is 15 mm, the pressure of the gas to be ejected is 0.08 MPa, and the inner diameter of the coating slit 19b portion of the coating nozzle 19 is 148. It was 2 mm. In the product 1 of the present invention, in order to obtain a uniform thickness, the distance between the coating slit 19b of the coating nozzle 19 and the outer peripheral surface 4c of the substrate 4 must be within 330 ± 20 μm. In the product 1 of the present invention, the inner diameter of the moving support member 31 is 147.35 mm, the pressure of the gas ejected from the ejection port 28 is 0.1 MPa, the ascending speed of the moving support member 31 is 30 mm / s, and the paint The discharge flow rate of 7 was 2.7 cc / sec.

  In this case, FIG. 14 shows the inner diameter of the substrate 4 when the substrates 4 having different inner diameters are attached to the coating film forming apparatus 1 of the product 1 of the present invention. 14 indicates the inner diameter of each substrate 4 before being attached to the coating film forming apparatus 1, and the vertical axis in FIG. 14 is the inner diameter of each substrate 4 after being attached to the coating film forming apparatus 1. Is shown.

  According to FIG. 14, even when the base 4 has an inner diameter of 0.1 mm, the difference in the inner diameter becomes 20 μm or less when attached to the coating film forming apparatus 1 of the product 1 of the present invention. That is, in the product 1 of the present invention, it has been clarified that the distance between the outer peripheral surface 4c of the substrate 4 and the coating slit 19b of the coating nozzle 19 can be within a certain range.

  Next, in the second experiment whose result is shown in FIG. 15, in addition to the product 1 of the present invention, in the product 2 of the present invention, the product 3 of the present invention and the comparative example, it is made of polyimide, the inner diameter is 147.1 mm, the length is A two-component mixed addition-type thermosetting resin liquid silicone elastomer having a viscosity of 20000 Pa · s (Pascal second) was applied as a coating 7 to a base 4 having a thickness of 420 mm and a thickness of 110 μm. The coating film 8 was formed so as to have a thickness of 200 ± 30 μm (thickness for obtaining good image quality required for the fixing belt 2) after vulcanization. In addition, after application | coating, 25 mm of each both ends of the base | substrate 4 are cut | disconnected, and the said base body 4 is made into 370 mm full length.

  In the product 2 of the present invention, in the coating film forming apparatus 1 of the second embodiment described above, the total length of the airtight chamber 46 is 30 mm, the outer diameter is 148.21 mm, and the width provided at the upper end of the mandrel 25 is 2 mm. Sixteen 16 mm diameter nozzle outlets 28 and exhaust outlets 47 were formed at equal intervals in the circumferential direction and opened at the bottom of the V groove. Further, the outer diameter of the mandrel 25 other than the airtight chamber 46 was set to 145.14 mm, and other conditions were the same as those of the product 1 of the present invention described above.

  In the product 3 of the present invention, in the coating film forming apparatus 1 of the above-described third embodiment, a CCD type having a resolution of 1 μm is used as the laser displacement meter, and regulators 43a and 43b having a pressure adjustment accuracy of 1 kPa are used. . Other conditions were the same as those of the product 1 of the present invention described above.

  In the comparative example, in the conventional coating film forming apparatus shown in FIG. 19, the total length of the mandrel as the support member 72 was set to 950 mm, and the length was at least twice the total length of the substrate as the object to be coated 70.

  In FIG. 15, the position of the outer peripheral surface 4 c of the base body 4 when the base bodies 4 having the same inner diameter are moved along the axis of the mandrel 25 in the above-described invention products 1 to 3 and the comparative example. Measured with a laser displacement meter. The horizontal axis indicates the position of the base 4 in the axis P direction, and the vertical axis indicates the position of the outer peripheral surface 4c of the base 4 (the outer diameter of the base 4 and the distance between the outer peripheral surface 4c of the base 4 and the coating nozzle 19). Show.

  According to FIG. 15, the positions of the outer peripheral surface 4c of the substrate 4 are substantially constant in any of the products 1 to 3 of the present invention except for the portions within 15 mm from the ends of both end portions 4a and 4b of the substrate 4. On the other hand, in the comparative example, it became clear that the outer diameter of the base 4 becomes wider toward the center of the base 4 in the comparative example. This is because with the movement of the base body 4, the distance from the jet port for jetting the gas to the position where the air is released to the atmosphere changes, and the pressure in the space between the mandrel 25 and the base body 4 changes. In particular, in a state where the central portion of the base body 4 reaches the jet port 28, the resistance until the gas is released to the atmosphere is the highest, and the pressure in the space between the mandrel 25 and the base body 4 is the highest. The base 4 is also in the most swelled state.

  Further, according to FIG. 15, also in the product 1 of the present invention, the pressure in the space between the mandrel 25 and the substrate 4 when reaching the spout 28 within 15 mm from the ends of both ends 4 a and 4 b of the substrate 4. The distance between the outer peripheral surface 4c of the substrate 4 and the coating slit 19b of the coating nozzle 19 cannot be kept constant, and the coating film 8 having a uniform thickness cannot be formed. As shown in FIGS. 16A and 16B, when the coating nozzle 19 is disposed between the base portion 27a of the tapered surface 27 serving as the upper end of the mandrel 25 and the ejection port 28, Ls and Le The coating film 8 having a uniform thickness cannot be obtained. As shown in FIG. 16 (c), when the coating nozzle 1 is arranged below the jet nozzle 28, the range in which the coating film 8 having a uniform thickness cannot be obtained is a range longer than Ls + Le indicated by Lo in the drawing. turn into. That is, the shortest axial length of the flow path from the jet outlet 28 until the gas flows along the inner periphery of the base 4 and is released to the atmosphere is the length outside the thickness tolerance application at both ends 4a and 4b of the base 4 It became clear that it was necessary to make it less than the sum.

  Next, in the inventive product 1, the inventive product 2, the inventive product 3 and the comparative example described above, the base 4 having a different inner diameter is held and the base 4 is moved along the axis of the mandrel 25. The variation in the position of the outer peripheral surface 4c of the base 4 was measured. The measurement results are shown in FIG. In FIG. 17, the horizontal axis indicates the variation (deviation) of the inner diameter of the substrate 4, and the vertical axis indicates the variation in the position of the outer peripheral surface 4 c of the substrate 4. In FIG. 17, the product 1 of the present invention is indicated by white diamonds, the product 2 of the present invention is indicated by white triangles, the product 3 of the present invention is indicated by white circles, and a comparative example is indicated by a black square. According to FIG. 17, in the comparative example, when the inner diameter of the base 4 is increased, the variation in the position of the outer peripheral surface 4c of the base 4 is also increased. However, in the products 1 to 3 of the present invention, the inner diameter of the substrate 4 is large. Even in this case, it became clear that the variation in the position of the outer peripheral surface 4c of the base body 4 did not increase while maintaining less than 40 μm.

  Moreover, the deviation of the thickness of the coating film 8 when the coating film forming apparatus 1 of this invention 1 thru | or this invention product 3 and a comparative example formed the coating film 8 in each base | substrate 4 shown in FIG. 17 is shown in FIG. . In FIG. 18, the product 1 of the present invention is indicated by white diamonds, the product 2 of the present invention is indicated by white triangles, the product 3 of the present invention is indicated by white circles, and a comparative example is indicated by a black square.

  According to FIG. 18, in the comparative example, when the inner diameter of the substrate 4 is increased, the variation in the thickness of the coating film 8 is increased, but in the products 1 to 3 of the present invention, even if the inner diameter of the substrate 4 is increased. It has been clarified that the variation in the thickness of the coating film 8 does not increase while keeping the thickness below 60 μm. In FIGS. 17 and 18, four locations are measured in the circumferential direction at locations of 40 mm, 210 mm, and 380 mm from the upper end of the base 4, and the deviations at a total of 12 locations are obtained to obtain the value on the vertical axis. Yes.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention. The coating film forming apparatus of the present invention is a coating of cylindrical members (belts and tubes) and columnar members used for fixing, pressing, charging, developing, etc. in image forming apparatuses such as copying machines, facsimiles, and LBPs. It can be applied to.

DESCRIPTION OF SYMBOLS 1 Coating film formation apparatus 2 Fixing belt (electrophotographic fixing member)
4 Substrate (object to be coated)
4c Outer peripheral surface 7 Paint 8 Paint 13 Control device (control means)
19 Application nozzle 19b Application slit (Discharge port)
25 Mandrel (supporting member)
26 Moving support (moving means)
27b Base (top)
28 Spout 31 Member for movement support 31a End face 39 Second spout 40 Second exhaust 43b Regulator (change means)
45 Laser displacement meter (measuring means)
47 Exhaust port 101 Image forming apparatus

Japanese Patent Laid-Open No. 2004-290853

Claims (7)

A support member that passes through a cylindrical object to be coated, an application nozzle that applies the paint to the outer peripheral surface of the object to be coated, and the object to be coated along the axis of the object to be coated with the application nozzle. In the coating film forming apparatus having a moving means for relatively moving,
The upper end portion of the support member is provided with an outlet for ejecting gas toward the inner peripheral surface of the object to be coated, and the discharge port for discharging the paint of the application nozzle is provided at the upper end of the support member. It is provided in the position facing a part, The coating-film formation apparatus characterized by the above-mentioned.   The coating film forming apparatus according to claim 1, wherein the jet nozzles are provided at equal intervals in a circumferential direction of the support member.   The coating film forming apparatus according to claim 1, wherein an exhaust port penetrating the support member is provided below the jet port.   The supporting member is passed inside, the inner diameter is smaller than the outer diameter of the object to be coated and larger than the outer diameter of the supporting member, and the object to be coated is placed on an end surface by the moving means. 4. A moving support member that moves the member to be coated relative to the coating nozzle by moving the shaft along the axis of the support member is provided. The coating-film formation apparatus as described in any one.   5. The coating film forming apparatus according to claim 4, wherein the moving support member is provided with a second jet port for jetting gas toward the outer peripheral surface of the support member.   The coating film forming apparatus according to claim 5, wherein a second exhaust port is provided between the end face and the second jet port.   Measuring means capable of measuring the outer diameter of the object through which the support member is passed, change means capable of changing the pressure of the gas supplied into the ejection port, and the change means to the object to be coated The coating film forming apparatus according to any one of claims 1 to 6, further comprising a control unit that changes the pressure of the gas according to an outer diameter.

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