Image forming device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an image forming apparatus provided with a rotation driving mechanism for transmitting and driving the rotation of a motor to each part of a copying machine, a facsimile machine, a printer and the like.

【0002】

[Conventional technology]

FIG. 6 is an exploded perspective view showing a rotation drive mechanism in a conventional image forming apparatus. In FIG. 6, one ends of the metal studs 2a, 2b, 2c, 2d, 2e, and 2f are caulked and fixed to the side plate 1 of a sheet metal or the like, or press-fitted to fix the metal studs 2a, 2b, 2c, 2d, 2e, and 2f. The metal studs 2a to 2f are inserted, and resin gears 3a, 3b, 3c, 3d, 3e, and 3f are rotatably attached from the other end side. Further, the E-ring 4 for preventing the gears 3a to 3f from coming off is fitted and fixed in the concave portion at the other end of the metal studs 2a to 2f.

【0003】

Further, the side plate 4 is arranged so as to face the side plate 1, and the motor rotation drive mechanism 5 is fixed to the side plate 4. The rotational drive of the motor rotation drive mechanism 5 is transmitted to the shaft 6, and both ends of the shaft 6 are rotatably inserted into bearings 7 and 8 fixed to through holes 1a and 4a of the side plates 1 and 4. .. Further, a gear 9 for transmitting rotation from the gear 3b to the gear 3f is rotatably attached to the shaft 6. Further, a gear 10 that meshes with a gear of a motor shaft (not shown) of the motor rotation drive mechanism 5 is rotatably attached to the shaft 6.

【0004】

In such a rotation drive mechanism, the gears 3a to 3f, 9, 10 rotate at high speed and become a heavy load. For this reason, Hasuba gear is often used. In this case, the shaft 6 and the metal studs 2a to 2f are twisted due to the influence of the thrust force of the hasva gear, which causes unevenness in the copied image and uneven wear of the hasva gear is likely to occur. To improve this, a large diameter thick shaft 6 and metal studs 2a to 2f are used.

【0005】

Further, heat is generated due to rotational friction in the rotating portion of each part. This rotational friction heat is accumulated in the bearings 7 and 8 and is not transmitted to the side plates 1 and 4, and the rotational friction increases. For this reason, friction is reduced by using ball bearings, which have high transmission torque for high-load bearings (7,8).

【0006】

An example of Japanese Patent Application Laid-Open No. 60-190159 is known as an example of improvement of such a rotation drive mechanism. This publication example has a tubular portion that is inserted into the mounting hole of the bracket and inserts and supports the shaft end portion, and the substrate and the coupling that inserts this tubular portion into the mounting hole of the bracket and holds the bracket by sandwiching it. The members are integrally molded with abrasion resistant resin.

【0007】

[Problems to be Solved by the Invention]

However, in the image forming apparatus of the above-mentioned conventional example, the configuration is complicated and a large number of parts are required, and a tool (holder) for attaching the retaining E-ring 4 is also required, resulting in poor workability and recycling. It takes time and effort to disassemble when trying. Furthermore, if a thick shaft is used when using the Hasba gear, or if a ball bearing is used to reduce friction, the cost increases. In the example of the publication, the bracket is provided with a tubular portion for inserting and supporting the shaft end portion, which may complicate the configuration and increase the cost.

【0008】

The present invention solves the problems in such a conventional technique, the number of parts can be reduced, the cost can be reduced, the rotary support shaft is reinforced, and the heat generated by the rotation in the bearing portion is reduced. An object of the present invention is to provide an image forming apparatus capable of reducing frictional wear, obtaining accurate and reliable rotational drive, and forming an even image.

【0009】

[Means for solving problems]

In order to achieve the above object, the invention according to claim 1 conveys an image carrier, a developing device for developing an electrostatic latent image of the image carrier, and a transfer body, and displays a toner image on the transfer body. In an image forming apparatus including a rotation driving device for driving rotation in a transfer material conveying device to be fixed, the rotation driving device has both end shafts formed integrally with a gear, and one or both of the both end shafts are made of sheet metal. It is rotatably arranged by inserting it into a burring hole formed in the side plate.

【0010】

In the image forming apparatus according to claim 2, a metal stud is fixed between the two side plates by caulking, press-fitting, or screwing to hold the space between the two side plates, and the hasba gear is rotatably attached to the metal stud. It is a thing.

【0011】

The image forming apparatus according to claim 3 is such that the rotation driving device is arranged in the vicinity of a discharge fan provided in the device.

【0012】

With such a configuration, the rotary drive device in the image forming apparatus according to claim 1 rotatably inserts one or both ends of the shaft portions integrally formed with the gear into the burring holes formed in the side plates. And arrange it. Therefore, it is not necessary to use a metal stud or a preventive E-ring as in the conventional example, the number of parts is reduced, and the cost is reduced. Further, the rotation support shaft is reinforced, and the heat generated by the rotation of the bearing portion is reduced to reduce the frictional wear. As a result, accurate and reliable rotational drive can be obtained, and even image formation becomes possible.

【0013】

The image forming apparatus according to claim 2 fixes a metal stud between two side plates by caulking, press-fitting, or screwing to accurately and surely hold the space between the two side plates, and rotates a bearing on the metal stud. Since it is freely attached, the influence of the thrust force of the Hasba gear can be minimized, and the advantage of using the Hasba gear can be utilized by eliminating the need for expensive bearings such as ball bearings. Therefore, the rigidity and high accuracy of the rotary drive device can be obtained without increasing the number of parts.

【0014】

In the image forming apparatus according to claim 3, the rotary drive device is arranged close to the discharge fan in the device. In this case, the heat generated by the burring hole due to the rotation of the gear is directly transmitted to the side plate, and the heat is satisfactorily dissipated, so that the life of the rotation drive mechanism can be extended.

【0015】

BEST MODE FOR CARRYING OUT THE INVENTION

Next, an embodiment of the image forming apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing the configuration of an embodiment of the image forming apparatus of the present invention. In FIG. 1, around the photoconductor 1 rotating in the direction of the arrow, a charging device 2 for charging the photoconductor 1, a laser optical system 3 for writing information to the photoconductor 1 with laser light, a cleaning device 6, and the like. A developing device 4 for irradiating the laser beam L from the laser optical system 3 and supplying toner 5 to reveal a latent image on the photoconductor 1, and transferring the toner image of this developing device 4 to paper. A transfer device 7 and the like are arranged.

【0016】

Further, the paper p in the paper feed cassette 20 which is arranged on the lower side in the drawing and can be attached and detached in the direction of arrow a is supported by the middle plate 22, and is connected to the paper feed roller via the arm 21 by the elasticity of a spring (not shown). Be pressed.

【0017】

Further, the paper feed roller 24 rotates under the control of the control unit of the printed circuit board (engine driver) 51, and the top paper in the paper p in the paper feed cassette 20 is the separation pad 23 to prevent the overlapping feed. , It is conveyed to the resist roller 25 on the downstream side, and is sent to the transfer device 7 at the timing synchronized with the image written by the laser beam L on the photoconductor 1.

【0018】

The transfer device 7 conveys the paper on which the toner image is transferred from the photoconductor 1 to the fixing device 30, where the paper passes between the fixing roller 32 containing the heater 31 and the pressure roller 33 that opposes pressure welding. The toner image is heated and pressed to be fixed. After that, the image-formed paper is ejected from the output roller 40 onto the output tray portion 45 with the image side facing down. The discharge paper stopper 46 can be moved in the direction of arrow b in order to correspond to the size of the discharge paper.

【0019】

In the figure, the operation surface is provided on the upper right, and the operation panel 47 projects on the entire upper surface of the exterior body 50 (the upper end of the device in the figure). In addition, the paper feed tray 49 is rotatably attached by pin 48.

【0020】

The power supply 50, the printed circuit board (engine driver) 51, and the controller board 52 are housed in the case 53 arranged on the left side in the figure. A substantially inverted U-shaped optical writing unit is formed in the laser beam L of the laser optical system 3, and a polygon motor 3a that displaces the laser beam L according to the writing information is arranged below the photoconductor 1 and the developing device 4. Has been done.

【0021】

The cover 41 constituting the output tray portion 45 is arranged so as to rotate the fulcrum portion 42 and to be removable. Further, the pin 48 detachably supports the structure on the right side in the drawing, facilitating the paper removal of the paper jam and the replacement and maintenance of the photoconductor 1 and the developing device 4. Further, a detector 54 for detecting the remaining state of the toner 5 is provided, and a fan F for exhausting internal heat is also provided. The paper detectors S1 and S2 provided in the paper transport path turn on / off a clutch (not shown) to detect the paper and drive the resist roller 25, and also detect a jam of the paper. ..

【0022】

FIG. 2 is a perspective view showing the rotation drive mechanism in the image forming apparatus shown in FIG. 1 in an exploded manner. In FIG. 2, this rotary drive mechanism has side plates 91, 92 of sheet metal and a main motor portion 93, and burring holes 95a, 95b, 95c, 95d, 95e, 95f are formed in the side plate 91. One end of each of the studs 98a and 98b is fixed by caulking or press-fitting into a hole (not shown) of the side plate 91, and a gear 90a and a gear similar to this gear 90a are inserted from the other end side of each of the studs 98a and 98b. Can be mounted freely.

【0023】

Further, the shaft portions of the gears 90b, 90c, 95d are rotatably inserted into the burring holes 95b, 95c, 95d. Further, a gear shaft portion similar to the gear 90d is rotatably inserted into the burring hole 95e. Further, the shaft portion of the gear 90f is rotatably inserted into the burring hole 95f. Further, one end of the stud 98c is fixed by caulking or press-fitting into a hole (not shown) of the side plate 91, and the gear 90f is rotatably inserted and attached from the other end side of the stud 98c.

【0024】

The gear is integrally formed with the shaft by plastic molding. Further, as the gears 90a and 90f inserted through the studs 98a, 98b and 98c, a hasba gear for high load is used.

【0025】

The side plate 92 is arranged so as to face such a side plate 91. In this case, the side plate 92 is fixed to the side plate 91 by inserting the screws 108a and 108b through the through holes of the side plate 92 and screwing them into the screw holes provided at the other ends of the studs 98c and 98b. That is, the side plates 91 and 92 are held and fixed at a constant level. At this time, the shaft portion at the other end of the gear 90c is rotatably inserted into the burring hole 109a of the side plate 92.

【0026】

Further, the shaft portion at the other end of the gear 90b is rotatably inserted into the burring hole 110 of the side plate 92. Further, the other end of the stud 98b is inserted into the burring hole 109c of the side plate 92, and the shaft portion at the end of the gear 90d is rotatably inserted into the burring holes 109b and 109c.

【0027】

Further, the shaft portion at the end of the gear 90e is rotatably inserted into the burring hole 109d. In this configuration, the rotational drive of the main motor unit 93 is transmitted to the photoconductor 1, the laser optical system 3, the cleaning device 6, the developing device 4, the transfer device 7, etc. by engaging the gears 90a to 90f to drive the rotation. Is.

【0028】

FIG. 3 is a cross-sectional view showing the mounting state of the gear 90c and the like. In FIG. 3, gears 115a and 115b are formed in the center of the gear 90c, the shaft portions 116a at one end on both sides thereof are rotatably inserted into the burring holes 90c of the side plate 91, and the shaft portion 116b at the other end is the side plate 92. It is rotatably inserted into the burring hole 109a. Other gears having the same configuration have the same configuration.

【0029】

FIG. 4 is a cross-sectional view showing the mounting state of the gear 90b. In FIG. 4, gears 118a and 118b are formed on both sides of the gear 90b, and the shaft portion 119a at one end on both sides thereof is rotatably inserted into the burring hole 95b of the side plate 91, and the gear 118a protrudes from the side plate 91. .. Further, the shaft portion 119b at the other end is rotatably inserted into the burring hole 110 of the side plate 92.

【0030】

With such a configuration, it is not necessary to use the E-ring for preventing the gear from coming off, which is inserted through the metal stud and attached as in the conventional example, the number of parts is reduced, and the cost is reduced. In addition, the rotary support shaft is reinforced. In addition, heat generation due to gear rotation is reduced, and frictional wear is reduced. Further, since the two side plates 91 and 92 are fixed by caulking, press-fitting or screwing the metal studs 98a to 98c, the space between the two side plates 91 and 92 is stably held.

【0031】

In addition, the influence of the thrust force of the hasba gears (gears 90a, 90f) attached to the metal studs 98a to 98c can be minimized, and the rigidity and high accuracy of the rotary drive device can be improved without increasing the number of parts. can get. As a result, accurate and reliable rotational drive can be obtained, and even image formation becomes possible.

【0032】

FIG. 5 is a schematic view showing a state in which the rotation drive mechanism having the configurations of FIGS. 2 to 4 is arranged in the image forming apparatus shown in FIG. In FIG. 5, a fan F for releasing the heat generated here and discharging ozone is provided in the apparatus. The fan F and the rotation drive mechanism 200 are arranged close to each other, and the heat generated when the gear shaft rotates in the burring hole is directly transmitted to the side plates 91 and 92. Therefore, the heat generated by the rotary drive mechanism 200 is efficiently discharged to the outside of the device, and as a result, the life of the rotary drive mechanism can be extended.

【0033】

[Effect of the invention]

As is clear from the above description, according to the image forming apparatus of the invention according to claim 1, one or both ends of the shaft portions of both ends formed integrally with the gear in the rotary drive device are formed in the burring holes formed in the side plates. Since it is rotatably inserted and arranged, it is not necessary to use an E-ring for preventing the gear from coming off, which is inserted and attached to the metal stud, and the number of parts is reduced and the cost is reduced. Further, the rotary support shaft is reinforced, and the heat generated by the rotation of the bearing portion is reduced to reduce the frictional wear, and as a result, an accurate and reliable rotary drive can be obtained. That is, it becomes possible to form an image without unevenness.

【0034】

According to the image forming apparatus according to claim 2, the metal studs are fixed between the two side plates by caulking, press-fitting, or screwing to hold the space between the two side plates, and the hasba gear can be rotated around the metal studs. Since it is attached, the influence of the thrust force of the Hasba gear can be minimized, and the advantage of using the Hasba gear can be utilized. Therefore, the rigidity and high accuracy of the rotary drive device can be obtained without increasing the number of parts.

【0035】

According to the image forming apparatus according to claim 3, since the rotary drive device is arranged close to the discharge fan in the device, heat generated by the burring hole due to the rotation of the gear directly transmitted to the side plate is dissipated. It is done well and the life of the rotary drive mechanism can be extended.

[Simple explanation of drawings]

[Figure 1]

It is a side view which shows the structure of embodiment of the image forming apparatus of this invention.

[Figure 2]

It is a perspective view which shows disassembled the rotation drive mechanism in the image forming apparatus shown in FIG.

[Fig. 3]

It is sectional drawing which shows the attachment state of the gear in embodiment.

[Fig. 4]

It is sectional drawing which shows the attachment state of the gear of another structure in embodiment.

[Fig. 5]

It is the schematic which shows the arrangement state of the rotation drive mechanism.

[Fig. 6]

It is an exploded perspective view which shows the rotation drive mechanism in the conventional image forming apparatus.

[Explanation of symbols]

1 Photoreceptor 2 Charging device 3 Laser optical system 6 Cleaning equipment 5 toner 4 developing device 7 Transfer device 20 Paper cassette 30 Fixing device 51 Printed circuit board 91,92 side plate 93 Main motor section 95a ~ 95f, 109a ~ 109d, 110 Burling holes 98a, 98b stud 90a ~ 90f gear 108a ~ 108c screw 115a, 116b gears 200 rotation drive