JP3885487B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus having a structure in which a fixing unit can be easily attached and detached.
[0002]
[Prior art]
Conventionally, in an image forming apparatus, a fixing unit is fixed to an apparatus main body with screws. Such fixing cannot absorb the thermal expansion of the fixing unit. Moreover, there was a problem that it took time to install.
[0003]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing unit fixing means that solves the above-mentioned problems, and to provide an image forming apparatus including a fixing unit that can be easily mounted and can absorb thermal expansion. It is.
[0004]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems, and is an image forming apparatus characterized by taking the following technical means. That is, the present invention is an image forming apparatus having a fixing unit formed by housing a roller pair consisting of a pressure roller for fixing an unfixed toner on a recording sheet and the heat roller in the housing, the side of the fixing unit guide The member is provided with a hook-like projection that is engaged with the main body device, and the main body of the device is composed of a hole that is large enough to allow the hook-shaped flange portion to enter and a slit-like hole that can move up and down only the web portion. In addition, a vertically long hole is provided for guiding and fixing the hook-like protrusions up and down, and the hook-like protrusions are inserted into the vertically long holes so that the side guide member can be moved up and down with respect to the apparatus main body. And a mechanism for fixing the fixing unit at a predetermined position of the apparatus main body by vertically moving the side guide member after the fixing unit is inserted into the apparatus main body along the side guide member. A forming apparatus.
[0005]
More specifically, in the image forming apparatus, the fixing unit includes U-shaped guides provided on both end faces of the fixing unit, and the side guide member includes a guide path for guiding the U-shaped guide , and the U-shaped guide. It is preferable to use an image forming apparatus provided with a long hole that movably holds a pin engaged in the U-shape .
[0006]
The apparatus main body is provided with a positioning member for positioning the fixing unit at a predetermined position, and the positioning member has dimensions to engage with U-shaped guides provided at a plurality of locations of the fixing unit, and the side guide member An image forming apparatus having a mechanism in which the U-shaped guide is sandwiched between a side guide member and an apparatus main body side positioning member in accordance with the movement to a predetermined position and the fixing unit is fixed is provided.
[0007]
In addition, when a diode or an electrical contact is provided at a corresponding position of the side guide member that contacts the contact on the fixing unit side with the side guide member fixed, the fixing unit is maintained at an appropriate potential. The desired conduction can be obtained.
[0008]
The side guide member may be provided with a drop-off preventing projection that is locked to the apparatus main body, and a regulating member that regulates the movement of the side guide member within a certain range.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
FIG. 11 is an explanatory diagram showing the entire image forming apparatus 100 to which the present invention is applied. The image forming apparatus 100 applies static electricity from the electrostatic roll 104 to the photosensitive drum 102 to charge it, and irradiates light such as laser from the exposure apparatus 106 to form a latent image on the photosensitive drum 102, and develops the developing device. The powder is supplied by the developing roll 110 and an image appears on the photosensitive drum 102. The paper supplied through the paper supply path 126 is passed between the photosensitive drum 102 and the transfer roll 112 to transfer the image onto the paper, and then the fixing roll 114 fixes the image on the paper. In the paper supply path, the paper is pulled out from the paper feed cassette 120, advanced by the feed rolls 122 and 124, positioned by the registration roll 126, and passed between the photosensitive roll 102 and the transfer roll 112 via the paper supply path 128 at the paper feed timing. To supply. The paper onto which the image has been transferred is fixed by the fixing roll 114 and discharged by the discharge roll 140. Reference numerals 130 and 132 denote paper feed levers. The present invention provides an apparatus characterized by the thermal fixing device 150 of the image forming apparatus 100.
[0011]
FIG. 10 is a perspective view of the image forming apparatus 100 showing a state before the fixing unit 10 is attached. The fixing unit 10 is configured by housing a roller pair composed of a fixing roller and a heating roller for fixing unfixed toner on a recording sheet in a housing. The left and right ends of the fixing unit 10 are locked to the left side L side guide member 30 and the right side R side guide member 60 as viewed from the depth side in FIG. The L-side side guide member 30 and the R-side side guide member 60 are attached to the main body of the image forming apparatus 100, and then the fixing unit 10 is horizontally mounted on the L-side side guide member 30 and the R-side side guide member 60 from the front side in FIG. Then, when both side guide members 30 and 60 are pushed down, the fixing unit 10 and the main body are fixed.
[0012]
FIG. 1 is a perspective view of an L-side end and an L-side side guide member 30 of the fixing unit 10 of the image forming apparatus according to the embodiment as viewed from the L-side outer side, and FIG. 2 is an L-side end and an L-side of the same fixing unit 10 as FIG. It is the perspective view which looked at the side side guide member 30 from the L side inner side. The L-side side guide member 30 has an L-shaped hook-like protrusion 42 protruding on the outer surface, and the protrusion 42 is inserted into a locking hole provided in the wall of the main body and temporarily held. A plurality of U-shaped guides 14 protruding from the outer surface of the fixing unit are provided outside the left end frame 12 of the fixing unit 10 in a U-shaped shape. Guide paths 32 and 34 for guiding the U-shaped guides are provided inside the L-side side guide member 30, respectively. The fixing unit 10 is horizontally inserted into the L-side guide member 30 as indicated by the arrow 16 while the U-shaped guide 14 and the guide paths 32 and 34 are aligned . With the insertion into the L-side side guide member 30 of the constant wearing unit 10, the pin 36 is engaged in the U-shaped U-shaped guide 14. The pin 36 is held in a vertically long slot 38 that passes through the wall of the L-side side guide member 30.
[0013]
3 is a perspective view of the R-side end and the R-side guide member 60 of the fixing unit 10 as viewed from the R-side inside, and FIG. 4 is a perspective view of the R-side end and the R-side guide member 60 of the fixing unit 10 as viewed from the R-side outside. FIG. R-side side guide member 60 also has L-shaped hook-like projections 7 2 protruding on the outer surface, temporarily holding the projections 7 2 is inserted in the engaging hole provided in the wall of the body. On the outside of the right end frame 22 of the fixing unit 10, a plurality of U-shaped guides 24 in which the left end frame is similarly turned U-shaped are provided. Guide paths 62 and 64 for guiding the U-shaped guide are provided inside the R-side side guide member 60. The fixing unit 10 is inserted horizontally into the R-side side guide member 60 as indicated by the arrow 26 while the U-shaped guide 24 and the guide paths 62 and 64 are aligned . With the insertion, the pin 66 is engaged in the U-shaped U-shaped guide 24. The pin 66 is held in a vertically long slot 68 that passes through the wall of the R-side side guide member 60. As shown in FIG. 4, a diode 74 is mounted on the R-side side guide member 60, and a contact 28 is provided on the frame 22 of the fixing unit 10. This diode 74 is grounded so as to keep the heating roll and pressure roll of the fixing unit at a predetermined potential. When the fixing unit 10 is assembled, the contact 28 automatically contacts to form a ground circuit. Has been placed.
[0014]
As described above, the left and right side guide members 30 and 60 are assumed to be attached to the main body, and after the fixing unit 10 is horizontally inserted and engaged with them, the side guide members 30 and 60 on both sides are attached. When pressed down, the fixing unit 10 is fixed to the main body of the image forming apparatus 100. The fixing unit 10 may be removed by a procedure reverse to the above procedure.
[0015]
FIG. 5 is a schematic perspective view of a locking mechanism that locks the side guide member to the main body. Here, the locking mechanism portion of the side guide member 30 or 60 is schematically shown. 6 and 7 are attachment explanatory views for explaining attachment of the side guide member 30 or 60 to the main body. The side guide member 30 or 60 protrudes from an L-shaped protrusion 42 or 72 that is locked to the main body and prevents the side guide member from falling off. Moreover, the long hole 38 or 68 and 46 long in the vertical direction is provided. A locking pin 36 or 66 is fitted in the long hole 38 or 68 so as to be movable in the vertical direction.
[0016]
FIG. 6 schematically shows a wall 80 on the main body side to which the side guide member 30 or 60 is locked. The wall 80 is provided with a hole 82 through which the L-shaped protrusion 42 or 72 enters. The hole 82 is a square hole into which the entire upper end including the flange portion of the L-shaped protrusion 42 or 72 can enter, and below the hole 82 is a slit in which only the web portion of the L-shaped protrusion 42 or 72 can move up and down. It is a hole. The flange of the protrusion 42 or 72 prevents the side guide member from dropping off at the slit-like portion. When the L-shaped protrusion 42 or 72 of the side guide member 30 or 60 enters the upper end portion of the hole 82 of the wall 80 and the side guide member 30 or 60 is pushed down as indicated by an arrow 48, the L-shaped protrusion 42. Or 72 descend | falls and falls to the position shown by the code | symbol 42a or 72a. At this time, the long holes 38, 68, 46 of the side guide member 30 or 60 are lowered to positions indicated by reference numerals 38a, 68a. As shown in FIG. 7, when the screw 84 attached to the main body wall 80 enters the hole 46, the vertical movement range of the locking member 40 is restricted to the range 86 shown in FIG. 6.
[0017]
8 and 9 show an example of a mechanism in which the U-shaped guide 24 is sandwiched between the side guide member and the apparatus main body side positioning member and the fixing unit is fixed.
[0018]
As shown in FIG. 8, when the fixing unit 10 is inserted in the direction of the arrow 26, the pin 66 enters the U-shaped guide 24. The side guide 60 is provided with fixing unit fixing flat portions 51 and 52 as positioning members, and the U-shaped guide 24 is also provided with fixing flat portions 53 and 54 as positioning members. Next, as shown in FIG. 9, when the side guide 60 is moved in the direction of the arrow 48, the guide-side fixing flat portions 51 and 52 and the U-shaped guide-side fixing flat portions 53 and 54 which are positioning members are brought into contact with each other. The U-shaped guide 24 is sandwiched between the guide-side fixing flat portions 51 and 52 and the pin 66, and the fixing unit 10 is fixed at a predetermined position. At this time, if the side guide 60 has strength between the elongated hole 68 and the fixing flat portions 51 and 52, it is sufficient for fixing the fixing unit 10.
[0019]
【The invention's effect】
According to the present invention, the following excellent effects can be obtained.
[0020]
(A) The positioning of the fixing unit is easy and reliable.
[0021]
(B) If the strength of a part of the guide member is maintained, it is not moved by driving the fixing unit after being fixed. Therefore, it is possible to reduce banding and wear of the drive unit by maintaining the meshing accuracy of the gear train.
[0022]
(C) Since it is easy to mount the fixing unit, it is possible to reduce the number of man-hours for assembling or periodic replacement. Moreover, exchange by a customer is also easy.
[0023]
(D) Since the number of parts is small, the cost can be reduced.
[0024]
(E) Since the fixing unit is not fixed in the thermal expansion direction, the lamp is not easily damaged.
[Brief description of the drawings]
FIG. 1 is a perspective view of an L-side end and an L-side side guide member of a fixing unit as viewed from the outside of an L side.
FIG. 2 is a perspective view of an L side end and an L side guide member of the fixing unit as viewed from the L side inner side.
FIG. 3 is a perspective view of an R-side end and an R-side side guide member of the fixing unit as viewed from the R-side inner side.
FIG. 4 is a perspective view of an R-side end and an R-side side guide member of the fixing unit as viewed from the R-side outer side.
FIG. 5 is a perspective view of a locking member.
FIG. 6 is an explanatory drawing of attachment of the attachment portion of the locking member.
FIG. 7 is an explanatory drawing of attachment of the attachment portion of the locking member.
FIG. 8 is a diagram illustrating an example of a mechanism in which a U-shaped guide is sandwiched between a side guide member and an apparatus main body side positioning member and a fixing unit is fixed.
FIG. 9 is a diagram illustrating an example of a mechanism in which a fixing unit is fixed by sandwiching a U-shaped guide between a side guide member and an apparatus main body side positioning member.
FIG. 10 is a perspective view of the image forming apparatus showing a state before the heat fixing housing is attached.
FIG. 11 is an overall explanatory view of an image forming apparatus.
[Explanation of symbols]
10 fixing unit 12 left end frame 14 U-shaped guide 16 arrow 22 right end frame 24 U-shaped guide 26 arrow 28 contact 30 L side guide members 32, 34 guide path 36 pin 38 long hole 42 protrusion 46 long hole 48 arrow 51, 52 plane Part (positioning member)
53, 54 Plane portion (positioning member)
60 R-side side guide members 62 and 64 Guide path 66 Pin 68 Long hole 72 Protrusion 74 Diode 80 Wall 82 Long hole 84 Screw 86 Restriction range 100 Image forming apparatus 102 Photosensitive drum 104 Electrostatic roll 106 Exposure apparatus 108 Developer 110 Development Roll 112 Transfer roll 114 Fixing roll 120 Paper feed cassette 122, 124 Feed roll 126 Registration roll 128 Paper supply path 130, 132 Paper feed lever 140 Discharge roll 150 Thermal fixing device

Claims (5)

In an image forming apparatus including a fixing unit in which a pair of rollers each including a pressure roller and a heating roller for fixing unfixed toner on a recording sheet is housed in a housing, a side guide member of the fixing unit is attached to a main body device. The hook-shaped protrusions to be engaged are provided, and the apparatus main body is composed of a hole having a size that allows the hook-shaped flange portion to enter and a slit-shaped hole in which only the web portion can be raised and lowered. A vertically long hole is provided for guiding and fixing the protrusions up and down, and the hook-shaped protrusion is inserted into the vertically long hole so that the side guide member can be moved up and down with respect to the apparatus main body. An image forming apparatus comprising: a mechanism for fixing a fixing unit at a predetermined position of the apparatus main body by moving the side guide member up and down after being inserted into the apparatus main body along the member. The fixing unit comprises a U-shaped guides provided on both end surfaces of the fixing unit, the side guide member is a guide passage for guiding the U-shaped guide, a pin which engages in the U-shaped guide of the U-shape in the vertical The image forming apparatus according to claim 1, further comprising a long hole that is movably held .   The apparatus main body is provided with a positioning member for positioning the fixing unit at a predetermined position, and the positioning member has a size to be engaged with U-shaped guides provided at a plurality of locations of the fixing unit. 3. A mechanism for fixing a fixing unit, wherein the U-shaped guide is sandwiched between a side guide member and an apparatus main body side positioning member as it moves to a predetermined position. Image forming apparatus.   4. A diode or an electrical contact is provided at a corresponding position of the side guide member that contacts the contact on the fixing unit side in a state where the side guide member is fixed. Image forming apparatus.   5. The side guide member according to any one of claims 1 to 4, wherein a drop-off preventing protrusion that is locked to the apparatus main body is provided, and a restriction member that restricts the movement of the side guide member within a certain range is provided. The image forming apparatus described.

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