JP2014228679A - Recording material conveying device and image forming apparatus - Google Patents

Abstract

[PROBLEMS] To suppress a cooling effect by preventing a detent member from coming into contact with an end portion of a cooling member while fixing the cooling member to an apparatus structure. In a recording material transport apparatus that sandwiches and transports a recording material by a first transport mechanism (31) and a second transport mechanism (32) arranged to face each other, the first transport mechanism and the second transport At least one of the mechanisms includes a belt (56, 59), a tension member (55, 57, 58) for stretching the belt, and a cooling member (33) for cooling the recording material, and the inner peripheral surface of the belt. Is provided with a detent member (83) for preventing skewing with respect to the stretching member, and the cooling member is in contact with the inner peripheral surface of the belt and has a heat absorption surface (34) that takes heat of the recording material through the belt. A protrusion (71) protruding outward in the longitudinal direction from the heat absorption surface, and a connecting portion (72) for engaging the protrusion with the device structure, the protrusion being an interference with the detent member (83) A retreat space (84) is provided to prevent this. [Selection] Figure 7

Description

  The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine including these, and a recording material conveying apparatus used therefor.

  In an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction machine equipped with these, the toner transferred onto the recording material is fixed by heating and pressing with a fixing device. At this time, if the recording material is stacked on the paper discharge tray with heat, the toner is softened by the heat accumulated in the stacked recording materials, and the recording materials are further overlapped to generate pressure due to its own weight. As a result, the recording materials are blocked and stuck. This phenomenon is called a blocking phenomenon, and if a recording material in which the blocking phenomenon occurs is forcibly peeled off, the toner image will be broken. In order to suppress the blocking phenomenon, a cooling device (recording material conveying device) that sufficiently cools the recording material after heat fixing is necessary.

  2. Description of the Related Art Conventionally, there has been known a recording material conveyance device in which a cooling member is disposed on the inner periphery of a belt and heat of a recording medium conveyed via the belt is taken away by the cooling member (Patent Document 1).

  Also, there is a belt provided with a convex detent at the end of the inner circumference of the belt so that the conveyor belt does not meander (Patent Document 2).

  Moreover, in order to fix the position of a cooling member, there exists a thing which inserts the convex part of the edge part of a cooling member in the hole of a flame | frame, and abuts the side edge part of a cooling member to a flame | frame (patent document 3).

  In the case of Patent Document 3, the belt can be prevented from being skewed by the side surface of the main body frame, but the skew of the stretching roller that stretches the belt cannot be restrained. Therefore, in order to suppress skewing with respect to the stretching roller, when the offset of Patent Document 2 is provided, the cooling surface of the cooling member shown in Patent Document 3 and the offset are opposed to each other. There is a gap in Therefore, the cooling performance decreases due to the gap.

  On the other hand, if the position of the detent is outside the end of the cooling member in order to prevent the detent from coming into contact with the end of the cooling member, it becomes difficult to fix the cooling member and the frame.

  Therefore, an object of the present invention is to suppress a reduction in the cooling effect by preventing the detent member from coming into contact with the end of the cooling member while fixing the cooling member to the apparatus structure.

  In order to solve this problem, in the present invention, in a recording material conveying apparatus that sandwiches and conveys a recording material by a first conveying mechanism and a second conveying mechanism that are arranged to face each other, the first conveying mechanism and the first conveying mechanism At least one of the two transport mechanisms includes a belt, a tension member that stretches the belt, and a cooling member that cools the recording material, and an inner peripheral surface of the belt is inclined with respect to the tension member. A detent member is provided to prevent the line, and the cooling member protrudes outwardly in the longitudinal direction from the heat absorbing surface, which contacts the inner peripheral surface of the belt and takes the heat of the recording material through the belt. And a connecting portion for engaging the protrusion with an apparatus structure, and the protrusion has a retreat space for preventing interference with the detent member. Propose the device.

  Since the cooling member has a retracting space, interference between the cooling member and the detent member is prevented. Thereby, it is prevented that a gap is generated between the belt and the cooling member, and deterioration of the cooling performance is also prevented.

1 is a schematic configuration diagram of a color image forming apparatus according to an embodiment. It is a schematic block diagram of the cooling device which concerns on embodiment. It is a schematic block diagram of the back side of a cooling device. It is a schematic block diagram of the cooling device which concerns on other embodiment. It is a partial rear view of a 1st conveyance mechanism and a 2nd conveyance mechanism. It is the schematic which shows a detent member, Comprising: It is CC sectional drawing in FIG. It is a schematic perspective view which shows the relationship between a cooling member, a main body structure, and a belt. It is a schematic sectional drawing which shows Example 1 of a cooling member. It is a schematic sectional drawing which shows Example 2 of a cooling member. It is a schematic sectional drawing which shows Example 3 of a cooling member. It is the schematic of the internal passage flow path which is a flow path of a cooling fluid.

  FIG. 1 is a schematic configuration diagram of a color image forming apparatus according to an embodiment. The image forming apparatus shown in FIG. 1 includes a tandem type image forming unit in which four process units 1Y, 1C, 1M, and 1Bk as image forming units are arranged side by side. Each of the process units 1Y, 1C, 1M, and 1Bk is configured to be detachable from the image forming apparatus main body 200, and yellow (Y), cyan (C), magenta (M), and magenta (M) corresponding to the color separation components of the color image. The configuration is the same except that toners of different colors of black (Bk) are accommodated.

  Specifically, each of the process units 1Y, 1C, 1M, and 1Bk includes a drum-shaped photosensitive member 2 as a latent image carrier, a charging roller 3 as a charging unit that charges the surface of the photosensitive member 2, and a photosensitive member. 2 is provided with a developing device 4 as a developing means for forming a toner image on the surface of 2 and a cleaning blade 5 as a cleaning means for cleaning the surface of the photoreceptor 2. In FIG. 1, only the photoconductor 2, the charging roller 3, the developing device 4, and the cleaning blade 5 included in the yellow process unit 1 </ b> Y are denoted by reference numerals. Omitted.

  In FIG. 1, an exposure device 6 as an exposure means for exposing the surface of the photoreceptor 2 is disposed above each process unit 1Y, 1C, 1M, 1Bk. The exposure device 6 includes a light source, a polygon mirror, an f-θ lens, a reflection mirror, and the like, and irradiates the surface of each photoconductor 2 with laser light based on image data.

  A transfer device 7 is disposed below each process unit 1Y, 1C, 1M, 1Bk. The transfer device 7 has an intermediate transfer belt 10 constituted by an endless belt as a transfer body. The intermediate transfer belt 10 is stretched around a plurality of rollers 21 to 24 as support members, and when one of the rollers 21 to 24 rotates as a driving roller, the intermediate transfer belt 10 is changed to an arrow in the figure. It is configured to run around (rotate) in the direction shown.

  Four primary transfer rollers 11 as primary transfer means are disposed at positions facing the four photoconductors 2. Each primary transfer roller 11 presses the inner peripheral surface of the intermediate transfer belt 10 at each position, and a primary transfer nip is formed at a location where the pressed portion of the intermediate transfer belt 10 and each photoconductor 2 are in contact with each other. ing. Each primary transfer roller 11 is connected to a power source (not shown), and a predetermined direct current voltage (DC) and / or alternating current voltage (AC) is applied to the primary transfer roller 11.

  A secondary transfer roller 12 as a secondary transfer unit is disposed at a position facing one roller 24 that stretches the intermediate transfer belt 10. The secondary transfer roller 12 presses the outer peripheral surface of the intermediate transfer belt 10, and a secondary transfer nip is formed at a location where the secondary transfer roller 12 and the intermediate transfer belt 10 are in contact with each other. Similar to the primary transfer roller 11, the secondary transfer roller 12 is connected to a power source (not shown) so that a predetermined direct current voltage (DC) and / or alternating current voltage (AC) is applied to the secondary transfer roller 12. It has become.

  A plurality of paper feed cassettes 13 that contain sheet-like recording material P such as paper or OHP are disposed below the image forming apparatus main body 200. Each paper feed cassette 13 is provided with a paper feed roller 14 for feeding out the stored recording material P. A paper discharge tray 20 for stocking the recording material P discharged outside the apparatus is provided on the left outer surface of the image forming apparatus main body 200 in the drawing.

  In the image forming apparatus main body 200, a transport path R for transporting the recording material P from the paper feed cassette 13 to the paper discharge tray 20 through the secondary transfer nip is disposed. In the transport path R, a registration roller 15 is disposed upstream of the position of the secondary transfer roller 12 in the recording material transport direction. Further, a fixing device 8, a cooling device 9, and a pair of discharge rollers 16 are sequentially arranged on the downstream side in the recording material conveyance direction from the position of the secondary transfer roller 12. The fixing device 8 includes, for example, a fixing roller 17 as a fixing member having a heater (not shown) therein, and a pressure roller 18 as a pressure member that presses the fixing roller 17. A fixing nip is formed at a position where the fixing roller 17 and the pressure roller 18 are in contact with each other.

  The basic operation of the image forming apparatus will be described below with reference to FIG. When the image forming operation is started, the photoreceptors 2 of the process units 1Y, 1C, 1M, and 1Bk are rotated counterclockwise in the drawing, and the surface of each photoreceptor 2 is made to have a predetermined polarity by the charging roller 3. It is charged like this. Based on image information of a document read by a reading device (not shown), the surface of each photoconductor 2 charged from the exposure device 6 is irradiated with laser light, and an electrostatic latent image is formed on the surface of each photoconductor 2. Is done. At this time, the image information to be exposed on each photoconductor 2 is monochromatic image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. As the electrostatic latent image formed on the photosensitive member 2 is supplied with toner by each developing device 4, the electrostatic latent image is visualized (visualized) as a toner image.

  One of the rollers that stretches the intermediate transfer belt 10 is driven to rotate, and the intermediate transfer belt 10 runs around in the direction of the arrow in the figure. Also, a primary transfer nip between each primary transfer roller 11 and each photoreceptor 2 is applied to each primary transfer roller 11 by applying a constant voltage or a voltage controlled by a constant current opposite to the charging polarity of the toner. A transfer electric field is formed. Then, the toner images of the respective colors formed on the respective photoconductors 2 are sequentially superimposed and transferred onto the intermediate transfer belt 10 by the transfer electric field formed in the primary transfer nip. Thus, the intermediate transfer belt 10 carries a full-color toner image on its surface. Further, the toner on each photoreceptor 2 that could not be transferred to the intermediate transfer belt 10 is removed by the cleaning blade 5.

  As the paper feed roller 14 rotates, the recording material P is carried out of the paper feed cassette 13. The discharged recording material P is timed by the registration roller 15 and sent to the secondary transfer nip between the secondary transfer roller 12 and the intermediate transfer belt 10. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the intermediate transfer belt 10 is applied to the secondary transfer roller 12, thereby forming a transfer electric field in the secondary transfer nip. Then, the toner images on the intermediate transfer belt 10 are collectively transferred onto the recording material P by the transfer electric field formed in the secondary transfer nip. Thereafter, the recording material P is fed into the fixing device 8, and the recording material P is pressurized and heated by the fixing roller 17 and the pressure roller 18 to fix the toner image on the recording material P. The recording material P is cooled by the cooling device 9 and then discharged to the paper discharge tray 20 by the pair of discharge rollers 16.

  The above description is an image forming operation when a full-color image is formed on a recording material. A single color image is formed using any one of the four process units 1Y, 1C, 1M, and 1Bk, and 2 Two or three process units can be used to form a two or three color image.

  By the way, as shown in FIG. 2, the cooling device as the recording material conveying device includes a cooling member 33 for cooling the sheet-like recording material P conveyed by the belt traveling of the belt conveying means 30. The belt conveying means 30 is arranged on the first conveyance mechanism 31 arranged on one surface (front surface or upper surface) side of the sheet-like recording material P and on the other surface (back surface or lower surface) side of the sheet-like recording material P. The second transport mechanism 32 is provided. Each transport mechanism is provided with a cooling member 33, and a cooling member 33a as a first cooling unit is disposed on one surface (back surface or lower surface) side of the sheet-like recording material P, and serves as a second cooling unit. The cooling member 33b is disposed on the other surface (front surface or upper surface) side of the sheet-shaped recording material P, and the cooling member 33c as the third cooling unit is disposed on the other surface (rear surface or lower surface) side of the sheet-shaped recording material P. Has been.

  The cooling members 33a, 33b, and 33c are arranged so as to be shifted along the traveling direction of the sheet-like recording material. Also, one cooling member 33b is a flat arc-shaped heat absorbing surface 34b whose bottom surface is slightly expanded, and the other cooling members 33a and 33c are flat arc-shaped heat absorbing surfaces whose top surface is slightly expanded. 34a and 34c. In each of the cooling members 33a, 33b, and 33c, a coolant flow path through which the coolant flows is formed.

  As shown in FIG. 3, the cooling device includes a heat receiving part 45 that receives heat from the recording material P as a heat generating part, a heat radiating part 46 that radiates heat from the heat receiving part 45, a heat receiving part 45, and a heat radiating part 46. A coolant circulation circuit 44 having a circulation path 47 through which the coolant circulates. In this circulation path 47, a pump 48 for circulating the coolant and a liquid storage tank 49 for storing the coolant are arranged. Then, the cooling members 33 a, 33 b, and 33 c that are liquid cooling plates are caused to function as the heat receiving unit 45. Further, the heat dissipating part 46 is composed of a radiator or the like. The coolant includes, for example, water as a main component, propylene glycol or ethylene glycol for lowering the freezing temperature, and a rust preventive for preventing rust of metal parts (for example, phosphate-based material: phosphorus Acid potassium salt, inorganic potassium salt and the like).

  As the circulation path 47, a pipe 50 that connects one opening of the cooling member 33c and the liquid storage tank 49, and a pipe 60 that connects the other opening of the cooling member 33a and one opening of the cooling member 33b. A pipe 51 connecting the other opening of the cooling member 33b and one opening of the cooling member 33c, a pipe 52 connecting the other opening of the cooling member 33c and the radiator as the heat radiating section 46, and heat radiation A pipe 53 connecting the radiator as the section 46 and the pump 48 and a pipe 54 connecting the pump 48 and the liquid storage tank 49 are provided. The circulation path 47 having the pipes 50, 60, 51, 52, 53, and 54 forms one flow path, but meanders in the cooling members 33a, 33b, and 33c, so that the cooling liquid is effectively used. The cooling member is cooled.

  The first transport mechanism 31 includes a plurality of (four in the illustrated example) rollers (driven rollers) 55, a belt (conveyance belt) 56 that is wound around the rollers 55, and presses the belt 56 from the outside. One roller (driven roller) 55e for adjusting the tension of the belt 56 is provided. The second transport mechanism 32 includes a plurality (four in the illustrated example) of rollers (driven rollers) 57c, 57d, 58, a drive roller 57a, and a belt (conveyance belt) 59 wound around the rollers 57, 58. With. Each roller is a tension member for the belt.

  Therefore, when the recording material P is conveyed, the recording material P is nipped and conveyed by the belt 56 of the first conveying mechanism 31 and the belt 59 of the second conveying mechanism 32 which are arranged to face each other. Become. That is, when the driving roller 57a is driven, as shown in FIG. 2, the belt 59 travels in the direction of the arrow A, and the second transport mechanism 32 passes through the recording material P sandwiched between the belts 56 and 59. As the belt 59 travels, the belt 56 of the first transport mechanism 31 travels in the arrow B direction. As a result, the recording material P is conveyed from the upstream side to the downstream side along the arrow C direction.

  Here, the driven roller 55e presses the belt 56 from the outside by a spring and adjusts the tension of the belt 56 appropriately. However, if the release is released, the belt 56 bends. Can be removed.

  Next, the operation of the cooling device configured as described above will be described. When the recording material P is nipped and conveyed, as shown in FIG. 2 and the like, the first conveyance mechanism 31 and the second conveyance mechanism 32 are brought close to each other. In the state shown in FIG. 2, if the driving roller 57a of the second transport mechanism 32 is driven to rotate, the belts 56 and 59 run in the direction of the arrow as described above, and the recording material P moves in the direction of the arrow. Run. In this state, the coolant is circulated in the coolant circulation circuit 44. That is, by driving the pump 48, the cooling liquid is caused to flow in the cooling liquid flow paths of the cooling members 33a, 33b, and 33c.

  At this time, the inner surface of the belt 56 of the first transport mechanism 31 slides on the heat absorbing surface 34b of the cooling member 33b, and the inner surface of the belt 59 of the second transport mechanism 32 cools with the heat absorbing surface 34a of the cooling member 33a. The heat absorbing surface 34c of the member 33c is slid. Therefore, the cooling member 33 b absorbs the heat of the recording material P from the front surface (upper surface) side of the recording material P via the belt 56. Further, the cooling members 33 c and 33 a absorb the heat of the recording material P through the belt 59 from the back surface (lower surface) side of the recording material P. In this case, the cooling members 33a, 33b, and 33c are kept at a low temperature by transporting the amount of heat absorbed by the cooling members 33a, 33b, and 33c to the outside.

  That is, by driving the pump 48, the coolant circulates in the coolant circulation circuit 44, flows through the coolant flow paths of the cooling members 33 a, 33 b, 33 c, absorbs heat, and becomes a high temperature coolant. By passing through a radiator that functions as a heat radiating section, heat is radiated to the outside air, and the temperature is lowered. Then, the coolant having a low temperature flows again in the coolant flow path, and the cooling members 33 a, 33 b, 33 c function as the heat radiating portion 46. For this reason, the recording material P is cooled from both sides by repeating this cycle.

  In this example, the cooling members 33 are arranged in order of the lower side, the upper side, and the lower side from the upstream side to the downstream side in the conveyance direction C of the recording material P. The cooling members 33a, 33b, and 33c have substantially the same shape, and the number of cooling members on the second transport mechanism 32 side is larger than that on the first transport mechanism 31 side. Accordingly, the total contact area of the cooling members 33a and 33c with the inner peripheral surface of the belt is larger than the contact area of the cooling member 33b with the inner peripheral surface of the belt, and the belt rotation resistance in the first transport mechanism 31 is the second It becomes smaller than the belt rotation resistance in the transport mechanism 32. The drive roller 57a is provided on the second transport mechanism 32 side having a higher belt rotation resistance.

  Here, the top surfaces of the heat absorbing surfaces 34a and 34c arranged on one side across the recording material conveyance path and the top surface of the heat absorption surface 34b arranged on the other side across the recording material conveyance path are in the recording material conveyance direction. It is located so as to be intertwined in the direction intersecting. As a result, the belts are intricately in contact with each other so that the rotation of the belt is stabilized and the difference in rotational speed generated between the conveyance belts is reduced, thereby achieving high-precision conveyance of the recording material by the conveyance belts. Can do.

The present invention is not limited to the cooling device using the coolant circulation circuit 44. Instead, the exhaust heat promoting shape portion 106 may be provided as shown in FIG. The exhaust heat promoting shape portion 106 is an air-cooled heat sink having a large number of fins. The above-described embodiment can be applied to the relationship between the heat absorbing surfaces 34a, 34b, 34c and the belts 56, 59 at this time.
Thus, by using the air-cooled heat sink structure, the coolant circulation circuit 44 can be omitted, and the apparatus can be made compact and low in cost.

FIG. 5 is a partial rear view of the first transport mechanism 31 and the second transport mechanism 32.
In the second transport mechanism 32, the rotation shaft 62 of the drive motor 61 as drive means rotates in the clockwise direction in the figure. The belt 63 is wound around a rotary shaft 62 and a large-diameter pulley such as a step pulley 64. The belt 65 is wound around the small-diameter pulley of the step pulley 64 and the shaft 66 that is the drive shaft of the drive roller 57a, and the drive is transmitted to the drive roller 57a.

  As shown in the drawing, at the recording material outlet of the cooling device 9, the driving roller 57a and the driven roller 55a facing each other via the two belts are separated from each other in the recording material conveyance direction and are arranged on the lower side. The upper end surface of 57a is located below the lower end surface of the driven roller 55a disposed on the upper side. The same applies to the rollers 55d and 57d arranged at the recording material inlet of the cooling device 9. Therefore, the recording material P conveyed from the fixing device 8 can smoothly enter the cooling device 9. Therefore, when the recording material P enters the cooling device 9 or is discharged, the recording material P is not subjected to a large load and the fixed image carried on the recording material P is not disturbed. The portion of the belt 56 that is in contact with the outer periphery of the driven roller 55a and the portion of the belt 59 that is in contact with the outer periphery of the drive roller 57a are not in contact.

  After all, the belt 56 of the first transport mechanism 31 and the belt 59 of the second transport mechanism 32 are in contact with each other at least in a region facing the heat absorbing surfaces 34a, 34b, and 34c of the cooling member 33c. The driving roller 57a and the driven roller 55a, and the driven roller 57d and the driven roller 55d are not in contact with each other. Therefore, when the driving roller 57a rotates in the direction of the arrow and the belt 59 of the second transport mechanism 32 rotates, the belts in the portion between the cooling member 33a and the cooling member 33c come into contact with each other, so The belt 56 of the first transport mechanism 31 is rotated.

FIG. 6 is a schematic view showing the detent member 83 and is a cross-sectional view taken along the line CC in FIG.
As shown in the figure, the detent member 83 provided on the belt 56 comes into contact with the end of the aluminum driven roller 55d. The detent member 83 is attached to the end portion of the belt 56 over the entire inner circumference of the belt. The other end (not shown) is similarly configured. This prevents the belt 56 from shifting in the width direction with a simple configuration. The length of the driven roller 55e that presses the belt 56 from the outside is set so as to contact the belt 56 but not the friction portion 82. The material of the belt 56 is a thin film resin material such as polyimide.

  Further, as described above, the driven roller 55e presses the belt 56 from the outside. Here, when the driven roller 55 e is longer than the belt width and the friction portion 82 is provided on the belt 56, the driven roller 55 e comes into contact with the belt 56 and the friction portion 82. At this time, if the thickness of the friction part 82 is large, a difference in rotational speed occurs between the friction part 82 contacting the driven roller 55e and the belt 56, and the belt is easily loaded and easily damaged. Therefore, in order to avoid this, the thickness from the top of the rubber layer to the bottom of the bonding means is preferably about 0.1 to 0.5 mm. Silicon rubber, urethane rubber, nitrile rubber, ethylene propylene rubber, or the like may be used for the rubber layer. Further, dimples and protrusions may be formed on the surface of the rubber layer, thereby increasing the frictional force of the rubber layer and making it difficult to wear. The material of the belts 56 and 59 which are endless belts is a thin film resin material such as polyimide, and the thickness thereof is, for example, about 0.08 mm. Therefore, the friction part 82 is thicker than the belts 56 and 59. The length of the driven roller 55e may be set so as to contact the belt 56 but not to contact the friction portion 82.

FIG. 7 is a schematic perspective view showing the relationship among the cooling member, the main body structure 85 and the belts 56 and 59. FIG. 7A is an exploded view, and FIG. 7B is an assembly view. In addition, although only the cooling member 33a is taken out and described, since the other cooling members have the same configuration, the description is omitted.
As shown in FIG. 7A, the cooling member 33a includes a convex portion 90 on one end side in the longitudinal direction. A plurality of convex portions 90 are formed in the recording material conveyance direction, and engage with the engagement holes 92 of the main body structure 85.

  On the other hand, the cooling member 33a includes a connecting portion 72 to which pipes 52 and 51 shown in FIG. The connection portion 72 has a cylindrical shape and engages with the engagement hole 91 of the main body structure 85. In the case of the air-cooling type cooling device in FIG. 4, the pipe for transporting heat corresponds to the connection portion 72 because it is not a liquid cooling type.

  In this manner, the cooling member 33a is engaged with the engagement holes 91 and 92 of the main body structure 85, and both end surfaces in the longitudinal direction of the cooling member 33a abut against the main body structure 85. Thereby, the position of the longitudinal direction of the cooling member 33a is decided. It is more preferable to fix the cooling member to the main body structure 85 by a fixing means (not shown).

  Further, an endothermic surface 34 that takes away the heat of the recording material P is formed from the center of the cooling member 33a to both ends. The endothermic surface 34 has a width sufficient to face the recording material having the maximum width being conveyed. Further, on the end side from the heat absorbing surface 34, a protruding portion 71 having a retracting space 84 for accommodating the detent member 83 in a non-contact manner is formed.

  Accordingly, the skew of the belts 56 and 59 is suppressed by the detent member 83, while the detent member 83 passes through the retreat space 84, so that a gap is not generated between the belt and the heat absorbing surface 34. In addition, a decrease in cooling performance can be prevented.

  In the case of the drive transmission mechanism as described above, there is a case in which a sufficient frictional force necessary for the accompanying rotation cannot be obtained because it is not a configuration in which the rollers that stretch the belt are in pressure contact with each other. In particular, when the rotation of the belt 59 is started, the resistance force of the driven belt 56 is large, so that the belt 56 may slip. Therefore, it is preferable to stabilize the accompanying movement of the first conveying mechanism 31, that is, to improve the accompanying responsiveness of the first conveying mechanism 31 at the start of driving.

  Therefore, in the present invention, at least one of the belts has a friction portion on the opposite surface of the belt protruding portion protruding outward in the longitudinal direction from the heat absorbing surface of the cooling member, and the belt protruding portion is stretched by the cooling member. This friction part is brought into contact with the other belt protruding part or the friction part. The friction portion is provided on the opposed surfaces of the belts 56 and 59 in a region corresponding to the detent member 83.

  FIG. 8 is a schematic cross-sectional view showing Example 1 of the cooling member. FIG. 8A is a cross-sectional view taken along line AA in FIGS. 2 and 4, and is an enlarged view of the vicinity of the belt end portion on the near side in the direction penetrating the paper surface in FIG. FIG. 8B is a cross-sectional view taken along the line BB in FIGS. 2 and 4, the periphery of the belt end portion on the back side in the direction penetrating the paper surface has the same configuration, and the description is omitted.

  The belts 56 and 59 are stretched by the cooling member 33, and the belt portions (protruding portions) in the range of L1 protruding from the heat absorbing surface 34 of the cooling member are in tension as shown in FIG. At this time, it is preferable that the length of the protruding portion of the belt 59 is such that the force of F1 is applied upward to come into contact with the belt 56. If the protruding portion of the belt 59 is longer than L1, it is not preferable because the force with which the end portion of the belt 59 presses the belt 56 becomes weak even if the belt 56 is stretched by the cooling member.

  A friction portion 81 is provided in a region L1 where the end portion of the belt 59 shown in FIG. Further, a friction portion 82 is provided at a portion facing the friction portion 81 at the end portion of the belt 56. The friction portion may be provided at at least one end of the belt 59 or the belt 56. The belts 56 and 59 include a contact portion that contacts the cooling member, and a belt protrusion that protrudes from the cooling member on the outer side in the longitudinal direction of the cooling member.

  With this configuration, in addition to the sliding contact between the belts in the region facing the cooling member, the first more stable by the sliding contact between the belt end portions via the friction portions 81 and 82 provided on at least one belt. The accompanying rotation of the transport mechanism 31 is realized. Further, if the friction portions 81 and 82 are provided on both the belts 56 and 59, the belt can be more reliably rotated. In particular, it is possible to reduce slip between the belts by the frictional portions 81 and 82 acting immediately after the start of driving.

  Since the friction portions 81 and 82 are arranged outside the maximum conveyance width of the recording material, the recording material does not interfere with the friction portions 81 and 82 even if the maximum width recording material is conveyed. Further, the endothermic surface covers the maximum conveyance width of the recording material. Therefore, the image of the recording material conveyed is not scraped off by the friction portions 81 and 82, and the recording material can be cooled.

  The friction portions 81 and 82 may be formed of a PET base material that is a thin film base material and a rubber layer that is a rubber member, and these may be attached to the belt surface by an adhesive means such as a double-sided tape. In this case, as shown in FIG. 8, the end portion of the belt spreads in a Y-shape and becomes thick. However, by forming the retracting space 84 for accommodating the stopper member 83 in the cooling member, it is possible to prevent the stopper member 83 at the belt end from interfering with the cooling member during belt rotation.

  In the above description, the friction portions 81 and 82 are attached to the belt. However, the friction portion may be formed by performing uneven surface treatment on the belt surface.

FIG. 9 is a schematic sectional view showing Example 2 of the cooling member. FIG. 9A is a cross-sectional view taken along the line AA in FIGS. 2 and 4, and is an enlarged view of the vicinity of the belt end portion on the near side in the direction penetrating the paper surface in FIG. FIG. 9B is a cross-sectional view taken along the line BB in FIGS. 2 and 4, the periphery of the belt end portion on the back side in the direction penetrating the paper surface has the same configuration, and the description is omitted.
The shape of the cooling member is not limited to the shape shown in FIGS. 7 and 8. For example, as shown in FIG. 9, a groove-like retracting space 84 may be formed in the protruding portion 71. By configuring the retreat space 84 that accommodates the detent member 83 in this manner, the contact area between the main body structure 85 and the protrusion 71 of the cooling member increases, so that the cooling member can be more stably incorporated into the main body structure. Can be installed.

FIG. 10 is a schematic sectional view showing Example 3 of the cooling member. 10A is a cross-sectional view taken along the line AA in FIGS. 2 and 4, and is an enlarged view of the vicinity of the belt end portion on the near side in the direction penetrating the paper surface in FIG. FIG. 10B is a cross-sectional view taken along the line BB in FIGS. 2 and 4, the periphery of the belt end portion on the back side in the direction penetrating the paper surface has the same configuration, and the description is omitted.
If the cooling member is formed as shown in FIGS. 7, 8 and 9, the processing is relatively difficult or the processing cost is increased. Therefore, as shown in FIG. 10, the retraction space 84 for accommodating the detent member 83 may be formed by separately configuring the heat absorption surface 34 and the protruding portion 71. For example, the protrusion 71 is formed of a flat plate-like member extending in the longitudinal direction, and a coolant flow path is formed inside the protrusion. Further, the endothermic surface 34 is installed on the protrusion 71. As a result, the heat of the recording material is transmitted to the protruding portion 71 via the endothermic surface 34, and the recording material is cooled.

  Even if the shape of the flat arcuate endothermic surface 34 is complicated, by processing separately from the projecting portion 71, the workability becomes easy and the processing cost can be reduced.

  The present invention may be a mechanism that drives both the first transport mechanism 31 and the second transport mechanism 32. Further, at least one of the first transport mechanism 31 and the second transport mechanism 32 may be stretched by a belt, and the other may be configured by a guide plate or a roller.

Next, an internal passage channel that is a passage for cooling fluid will be described with reference to FIG.
As shown in FIG. 11A, the cooling member 33 provided in the cooling device 9 according to the present embodiment includes a plurality of parallel (parallel) plurality provided in a crossing (orthogonal) manner in the sheet conveyance direction. A straight flow path portion 112 which is a straight flow path portion is provided. Further, there is also a folded flow path portion 115 that guides the coolant by changing the flow direction in the vicinity of the end of the cooling member 33 from the adjacent straight flow path portion 112 on the upstream side in the cooling liquid conveyance direction to the downstream straight flow path portion 112. It is equipped. The plurality of straight flow channel portions 112 and the folded flow channel portion 115 constitute an internal flow channel that is a flow channel for the coolant in the cooling member 33. Further, the coolant is fed in the direction of the arrow in the drawing from the connection portion 72 connected to the inflow port of the straight linear flow channel portion 112 at the upper left portion in the drawing, and each folded flow channel portion 115 and the straight flow channel portion. 112. Then, the coolant that has passed through each folded flow path portion 115 and the straight flow path portion 112 flows out to the connection portion 72 connected to the outlet of the straight flow path portion 112 arranged in the lower left portion in the figure. Become.

  Further, in the cooling device 9 of the present embodiment, for the reason described below, a sheet passage area which is a passage area where the widest recording material P passing through the printer 200 passes over the heat absorbing surface 34 of the cooling member 33. Each folded flow path portion 115 is arranged outside the (recording material maximum conveyance width).

  Here, it is assumed that the folded flow path portions 115 are arranged on the inner side of the sheet passing area through which the recording material P passes on the heat absorbing surface 34 of the cooling member 33. As a result, each folded flow path portion 115 and the portion of the endothermic surface 34 close to each folded flow path portion 115 become colder than other portions. In other words, a portion near the both ends of the cooling member 33 in the direction perpendicular to the paper transport direction (hereinafter referred to as the longitudinal direction in the cooling member) has a wider portion that is cooler than the other portions. For this reason, a large deviation in the longitudinal direction occurs in the temperature of the sheet passing region of the heat absorbing surface 34 where the recording material P conveyed from the fixing device 8 toward the paper discharge tray 20 comes into sliding contact.

  The above-mentioned phenomenon is mainly caused by the area where the cooling liquid contacts the inner peripheral surface of the internal passage channel and performs heat exchange per unit width in the longitudinal direction of the cooling member 33. This is because the folded flow path portion 115 becomes larger than the range.

  11B and 11C, the retreat space 84 is also formed outside the maximum conveyance width of the recording material, and is at a position corresponding to the folded flow path portion 115. Therefore, the detent member 83 is also disposed outside the maximum conveyance width of the recording material, and is at a position corresponding to the folded flow path portion 115. Here, FIG.11 (b) is AA sectional drawing in Fig.11 (a), and respond | corresponds to the cooling member 33b. FIG.11 (c) is AA sectional drawing in Fig.11 (a), and respond | corresponds to the cooling members 33a and 33c. However, in FIGS. 11B and 11C, the friction portions 81 and 82 are omitted.

Next, an example of how to provide such an internal passage in the cooling member 33 will be described.
The following method is conceivable as an example of processing the cooling member 33 having an internal passage for cooling liquid having a plurality of folded flow path portions 115 inside. For example, first, a base material having a plurality of straight flow path portions 112 of a coolant having a circular cross section in parallel is made by extrusion processing of an aluminum material. Next, it is preferable to cut the folded flow path portion 115 of the coolant passage flow path so that the upstream and downstream straight flow path portions 112 are connected and finally sealed (sealed) by the sealing member 116. At this time, sealing with an O-ring, an adhesive, or a resin (for example, Nanomold, manufactured by Taisei Plus Co., Ltd.) is performed in order to reliably prevent the coolant from leaking with the sealing member 116.

9 Cooling device (recording material transport device)
31 1st conveyance mechanism 32 2nd conveyance mechanism 33 Cooling member 34 Endothermic surface 56,59 Belt 57a Drive roller (stretching member)
55, 57c, 57d, 58 Followed roller (stretching member)
71 Protruding portion 72 Connecting portion 81, 82 Friction portion 83 Shifting member 84 Retraction space

JP 2012-98677 A JP 2008-170478 A JP 2013-025038 A

Claims (6)

In the recording material conveying apparatus for nipping and conveying the recording material by the first conveying mechanism and the second conveying mechanism arranged to face each other,
At least one of the first transport mechanism and the second transport mechanism includes a belt, a stretching member that stretches the belt, and a cooling member that cools the recording material,
On the inner peripheral surface of the belt, a detent member that prevents skewing with respect to the tension member is provided,
The cooling member has a heat absorbing surface that contacts the inner peripheral surface of the belt and takes heat of the recording material via the belt, a protruding portion that protrudes outward in the longitudinal direction from the heat absorbing surface, and the protruding portion includes an apparatus structure. A connecting portion to be engaged with the body,
The recording material conveying apparatus according to claim 1, wherein the protrusion has a retreat space that prevents interference with the detent member. The belt of the second transport mechanism travels by being driven by driving means, and the belt of the first transport mechanism is rotated by the travel of the belt of the second transport mechanism,
The belt has a contact portion that contacts the cooling member, and a belt protrusion that protrudes outward in the longitudinal direction of the cooling member,
At least one of the belts has a friction portion on an opposing surface of the belt protrusion,
2. The recording material conveying apparatus according to claim 1, wherein in a state in which the belt protruding portion is stretched by the cooling member, the friction portion contacts the belt protruding portion or the friction portion facing each other.   3. The recording material conveying apparatus according to claim 1, wherein the friction portion is provided on an opposite surface of the belt in a region corresponding to the detent member.   The recording material conveying apparatus according to claim 1, wherein the evacuation space is formed outside the maximum recording material conveyance width on the cooling member.   The cooling member has a plurality of linear flow channel portions and at least one folded flow channel portion inside as a flow path for cooling liquid, and the retreat space is at a position corresponding to the folded flow channel portion. The recording material conveyance device according to claim 1, wherein the recording material conveyance device is a recording material conveyance device.   An image forming apparatus comprising: an image forming unit that forms an image on the recording material; and the recording material conveyance device according to claim 1 that conveys the recording material after image formation.

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