JP2004264593A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanism maintaining a clutch, transmitting and cutting off the driving force to a resist roll, from interfering even when a gear driving a process unit is a large diameter gear as well as easy to exchange and retained at a good precision and also taking into account heat discharging property in an image forming apparatus provided with a driving force transmitting mechanism to transmit the driving force to a paper feeding and carrying system, a process unit system constituted by a photoreceptor and a developing device and a fixing/paper ejecting system by a sigle motor and a clutch to transmit and shut off driving force. <P>SOLUTION: In the image forming apparatus, the clutch is a resist clutch assembly retaining a first gear transmitting the driving force from a motor to the clutch with a second gear transmitting and cutting off the driving force from the clutch in a clutch holder. The resist clutch assembly is installed one step upstream of a resist roll 7, in a position not interfering with a process unit driving gear. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine using the electrophotographic method, and more particularly, to a process unit system mainly composed of a photoconductor and a developing device by a single motor, In an image forming apparatus provided with a gear train for transmitting a driving force to a paper discharging system, a paper feeding / conveying system, etc., a means for transmitting and cutting a driving force to a registration roller provided near a process unit at a necessary timing is attached and detached. The present invention relates to an image forming apparatus having an easy and accurate installation mechanism.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine using an electrophotographic method, a recording paper accommodated in a recording paper accommodation device or a recording paper placed in a manual paper feed mechanism is picked up. A paper feed / transport system that sends the image to the registration rollers, a photoconductor that exposes the image to form a latent image, and develops the latent image on the photoconductor into a toner image. It is necessary to drive various parts, such as a process unit system for transferring an image to recording paper sent from a printer, a fixing / discharge system for heating and fixing and discharging the recording paper on which the toner image has been transferred. For this reason, conventionally, an image forming apparatus using a motor for each drive system has also been manufactured. However, with the personalization of the image forming apparatus itself, the need for miniaturization and cost reduction has arisen. An image forming apparatus which is reduced in size and excellent in assemblability has been demanded.
[0003]
Therefore, a single motor is used to transmit the driving force to the required driving force in the image forming apparatus, such as a paper feed / transport system, a process unit system composed of a photoconductor and a developing device, and a fixing / paper discharging system. An image forming apparatus in which a force transmitting mechanism is arranged on one sheet material, a clutch for transmitting and disconnecting the driving force at a required timing is arranged, and when a conveyance command is received, the clutch is connected to convey the recording paper. Various devices have been proposed, for example, as shown in Patent Document 1.
[0004]
Of these, the process unit system having the photoreceptor and the developing device requires the largest driving force, so a motor is arranged relatively near these process unit systems, and the driving force of the motor is increased by using extra gears. It is preferable in terms of cost to reduce the speed of transmission with one large-diameter gear without transmitting the gear. However, a registration roller that corrects the attitude of the recording sheet that has been sent and sends it to the transfer position in accordance with the timing of forming a toner image on the photoconductor is generally provided near the process unit. When a driving force is transmitted to the process unit system using a gear, if a clutch is directly connected to the registration roller, there is a possibility that the clutch will interfere with the process unit driving gear.
[0005]
In order to prevent such a situation, as shown in Patent Document 1, a reduction gear is further provided between the motor and the process unit to reduce the diameter of the process unit driving gear to a relatively small value. As shown in FIG. 2, there is a method of driving the process unit and the registration roller by different motors.
[0006]
Further, the registration roller has a function of correcting the attitude of the recording sheet sent as described above and sending it to the transfer position. For that purpose, it is necessary to hold the registration clutch with high accuracy. Since the registration roller is provided near the process unit, depending on the method of arranging the clutch, it may be necessary to remove the process unit drive gear and motor before removing the clutch for maintenance. Worsen. In addition, since the registration clutch needs to be energized in order to convey the recording paper, if the image formation is performed continuously, the energization is continuously energized and the temperature becomes extremely high. Therefore, when installing the resist clutch, it is necessary to consider its heat dissipation.
[0007]
[Patent Document 1]
JP-A-6-314001
[Patent Document 2]
JP-A-9-43928
[0008]
[Problems to be solved by the invention]
However, the method disclosed in Patent Document 1 in which a gear is disposed between a motor and a process unit to make the diameter of the process unit driving gear itself relatively small requires a separate gear, which increases the cost. Further, the method of driving the process unit and the registration roller by different motors as disclosed in Patent Document 2 also requires a plurality of motors, which increases costs.
[0009]
Therefore, in the present invention, a single motor is used to drive the image forming apparatus where driving force is required, such as a paper feed / transport system, a process unit system including a photoconductor and a developing device, and a fixing / paper discharge system. It has a driving force transmission mechanism that transmits force, and a clutch that transmits and disconnects this driving force to the conveyance rollers of the paper feed / conveyance system. When a conveyance command is received, the clutch is connected to convey the recording paper. In the image forming apparatus described above, the clutch for transmitting and disconnecting the driving force to the registration roller is prevented from interfering even if the gear for driving the process unit is a large-diameter gear, and can be easily exchanged and accurately held, and It is an object to provide an image forming apparatus having a mechanism considering heat dissipation.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention,
A drive plate composed of a single sheet of gear train that transmits driving force to a process unit system mainly composed of a photoconductor and a developing device, a fixing / discharge system, a paper feed / transport system, etc. by a single motor. And a registration roller that drives the recording paper to be fed at a predetermined timing to a transfer position of the toner image formed on the photoconductor by a clutch that transmits and disconnects the driving force from the gear train. ,
The clutch is a registration clutch assembly held by a clutch holder together with a first gear for transmitting a driving force from a motor to the clutch, and a second gear for transmitting and disconnecting the driving force by the clutch. The clutch assembly may be disposed at a position that does not interfere with the process unit drive gear and one stage upstream of the registration roller in the drive plate.
[0011]
In this way, by disposing the registration roller clutch as a registration clutch assembly one stage upstream of the registration roller so as not to interfere with the process unit drive gear, the process unit drive gear can be a single large-diameter gear. In addition, the shaft of the registration roller may be extended to a position where it meshes with the second gear in the registration clutch assembly. Therefore, the registration roller may be driven by a plurality of gears as in the conventional apparatus, or a plurality of motors may be used. It is not necessary to adopt a costly method, and the shaft can be shortened by that amount, so that the image forming apparatus can be provided at low cost.
[0012]
By arranging the registration roller clutch as a registration clutch assembly one stage upstream of the registration roller in this way, the driving force from the motor is an intermediate gear for the first gear in the registration clutch assembly. A fourth gear for transmitting the driving force from the motor to the intermediate gear, the first gear, and transmitting the driving force from the intermediate gear to another sheet feeding system. Since the third gear and the third gear are arranged at substantially equal intervals, even if the drive plate is formed of a single plate, the intermediate gear is evenly applied from the periphery, so that the gear shaft is stable without falling down. To transmit the driving force.
[0013]
Further, by providing a receiving hole for holding one end of the shaft portion of the second gear in the registration clutch assembly on the main body side of the image forming apparatus, the registration clutch assembly can be used in both the drive plate and the image forming apparatus main body. As a result, even if the resist clutch assembly protrudes from the drive plate, the driving force can be transmitted and disconnected accurately and stably.
[0014]
Further, the second gear has an outer diameter smaller than that of the first gear, and the resist clutch assembly is detachable from the drive plate while holding the second gear, thereby improving the assemblability. As a result, the image forming apparatus can be provided at low cost, and the registration clutch assembly can be easily removed for maintenance or the like.
[0015]
In addition, since the drive plate is made of metal, even if the registration roller clutch becomes hot due to continuous image formation, heat is transmitted to the metal drive plate and radiated, thereby promoting a cooling effect. Thus, overheating of the clutch can be prevented.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be illustratively described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention to them unless otherwise specified, and are merely mere descriptions. This is just an example.
[0017]
FIG. 1 is a conceptual diagram for explaining the main components of the image forming apparatus according to the present invention and the conveyance path of the recording paper. FIG. 2 is a view from the driving force transmission mechanism side excluding the outer cover of the image forming apparatus according to the present invention. FIG. 3 is a view showing a positional relationship between a gear train and a registration roller constituting a driving force transmission mechanism in the image forming apparatus of the present invention. FIG. 4 is a view showing a driving force transmission mechanism in the image forming apparatus of the present invention. FIG. 5 is a diagram showing a positional relationship between a gear train and a registration clutch, FIG. 5 is a plan view of a gear train forming a driving force transmission mechanism in the image forming apparatus of the present invention, and FIG. 6 is a base of the image forming apparatus according to the present invention. FIG. 7 is a diagram showing a receiving hole for holding one end of a shaft portion of a gear in a registration clutch assembly provided on a frame. FIG. 7 is a plan view (A) of a registration clutch assembly of an image forming apparatus according to a first embodiment of the present invention. And back (B), and left side view and (C) is a right side view (D), left and right side view is represented by vertical rotated for clarity. 8 is a rear perspective view (A) and a plan perspective view (B) of the first embodiment of the registration clutch assembly of the image forming apparatus according to the present invention, and FIG. 9 is a registration clutch of the image forming apparatus according to the present invention. A rear perspective view (A) and a plan perspective view (C) of a clutch holder according to a first embodiment of the assembly, and a view (B) showing a registration clutch main body, and FIG. 10 shows a registration clutch assembly according to the present invention. FIG. 11 is a perspective view of a second embodiment of a registration clutch assembly in an image forming apparatus according to the present invention, and FIG. 12 is a perspective view of a clutch holder according to the second embodiment. FIG. 13 is a perspective view of the clutch body, FIG. 13 is a perspective view of the clutch body according to the second embodiment, and FIG. The figure 14 is likewise perspective view of removing the gear assembly of the clutch body in the second embodiment (A) and viewed gear assembly from the back Fig. (B).
[0018]
In FIG. 1, the same components are denoted by the same reference numerals. In FIG. 1, 1 is a paper feed cassette containing recording paper 2, 3 is a paper feed pickup roller that picks up and feeds the recording paper 2, and 4 is A separation / feed roller for reliably separating and feeding the picked-up recording paper 2 one by one; 5 an intermediate roller; 6 a second paper feed roller for feeding the recording paper placed in a manual paper feed unit one by one; A registration roller that corrects the attitude of the recording paper 2 sent thereto and sends the recording paper to a transfer position in accordance with the timing of forming a toner image on the photoconductor 8, 8 is a photoconductor (image carrier), 9 is a transfer roller, 10 is a fixing roller, 11 is a discharge roller, 12 is a pickup roller 3, an intermediate roller 5, a second paper feed roller 6, and a registration roller 7 (a pair of rollers consisting of a metal roller 7a and a rubber roller 7b). Motor for sending a driving force to the photosensitive member (image carrier) 8, fixing roller 10, discharge roller 11, etc., 13 is a conveyance path for recording paper from the paper feed cassette 1, and 14 is a path from the manual paper feed unit. A manual paper feed path 15 for the recording paper is a feed path from the intermediate roller 5 to the discharge roller 11. Of these, a pickup roller 3, an intermediate roller 5, a second sheet supply roller 6, and a registration roller 7 constitute a sheet supply / transport system. Around the photosensitive member 8, a charging device (not shown) An exposure opening, a developing device, a cleaning blade (cleaning means) and the like are arranged to constitute a process unit, and a fixing / discharge system is constituted by the fixing roller 10 and the discharge roller 11. A transport guide and a transport roller (not shown) are provided from the separation / feed roller 4 to the intermediate roller 5, from the intermediate roller 5 to the registration roller 7, from the photoconductor 8 to the fixing roller 10, from the fixing roller 10 to the discharge roller 11. Have been. The process unit includes not only the above-described photoconductor (image carrier), charging device, exposure opening, developing device, cleaning blade, but also at least the photoconductor (image carrier) and the exposure opening and the developing device. It may include a device and may be integrated with some of these components.
[0019]
In FIG. 2, reference numeral 20 denotes an apparatus main body from which an outer cover of the image forming apparatus is removed, 21 denotes a base frame of the image forming apparatus in which a driving force transmission mechanism is disposed, 22 denotes a drive plate constituting the driving force transmission mechanism, and 23 denotes an image forming apparatus. Is a flapper solenoid that controls a spring clutch 25 that transmits and cuts a driving force to a second paper feed roller 6 for sending recording paper from the manual feed path 14 to the registration roller 7, and 26 is an intermediate roller 5 An intermediate clutch 27 controls rotation and stop of the registration roller 27 is a registration clutch assembly including a registration clutch body and a clutch holder that controls rotation and stop of the registration roller 7, 28 is a paper feed clutch that controls rotation and stop of the pickup roller 3 It is.
[0020]
3 to 5, reference numeral 30 denotes a gear provided on the drive shaft of the motor 12, reference numeral 31 denotes a process unit driving gear for transmitting driving force to the process unit, and reference numeral 32 denotes a driving force to a sheet feeding / transport system and a fixing / discharge system. , A second intermediate gear composed of a two-stage gear for transmitting the driving force from the first intermediate gear 32 to a third intermediate gear 34, and 35 a third intermediate gear The driving force is transmitted from the clutch gear 35 to the clutch gear 35 of the registration clutch assembly 27 which receives the driving force from the clutch gear 35 by the engagement and disengagement of the clutch. The transmission gear shafts 39 to 42 are gears for transmitting the driving force to the fixing roller 10, and the driving force is further transmitted to the discharge roller 11 from the gear on the fixing roller 10 by a gear train. . 43 is a two-stage gear that transmits driving force from the third intermediate gear 34 to the gear 44 of the intermediate clutch 26; 45 and 46 are gears that transmit driving force to the spring clutch 25; This is a gear for transmitting the driving force to the gear 48 of the second embodiment.
[0021]
In FIG. 6, reference numeral 74 denotes a gear shaft side end 73 of a shaft 75 (see FIGS. 7 and 9) of the resist clutch assembly 27 provided on the base frame 21. The shaft 73 is coaxial with the rotatably inserted hole 65. 7 to 10, reference numeral 60 denotes a holder of the resist clutch assembly 27; 61, a clutch body 77 integrated with the holder 27 and the gear shaft 36; 62, 63 A positioning cross-shaped projection for attaching the clutch assembly 27 to the drive plate 22, 64 is a hole into which the clutch shaft 76 (see FIG. 9) is inserted, 65 is a hole in the boss 72, and 66 is a rotation stop 79 of the clutch 61. Notch, 67 is a detent member for locking the rotation stopper 79, 68 is a notch for adjusting the detachment strength of the clutch body 61, Reference numeral 9 denotes a position regulating projection when the resist clutch assembly 27 is mounted on the drive plate 22; 70, an escape hole of an oil protect portion 78 of the clutch 61; 71, a gear shaft 36 fitted into the clutch body 61; A notch provided so as to be able to mesh with the boss, a boss 72 disposed coaxially with a hole 65 for rotatably fitting a shaft 75 of the clutch body 61, and driving forces 75 and 76 when the clutch is engaged. (See FIG. 9) of the gear shaft 36, 77 is a clutch main body, 78 is an oil protect portion of the clutch, 79 is a rotation stop of the clutch main body, 80 is a power input terminal of the clutch main body 77, 81 is a drive plate 22 To form the retaining projection 82 when the holder clutch assembly 27 is inserted into the Numeral 83 denotes a grip portion for pressing the projection 82 when the resist clutch assembly 27 secured by the projection 82 is removed from the drive plate 22; 84, a harness processing bracket; The fixing member 87 is a beam having a tapered portion 81, a retaining projection 82, and a grip 83.
[0022]
11 to 14, reference numeral 100 denotes a second embodiment of the registration clutch assembly in the image forming apparatus of the present invention, 101 denotes a holder of the registration clutch assembly according to the second embodiment, and 102 denotes a clutch and a gear which are also integrated. 103, a wall on the clutch body side; 104, a hole into which the gear shaft 117 of the clutch enters; 105, 106, positioning bosses of the resist clutch assembly 100; 107, an escape hole for the oil protect portion 112 of the clutch 102; Is a boss, 109 is a hole in the boss 108, 110 is a gear shaft, 111 is a clutch gear, 112 is an oil protector, 113 is a clutch body, 114 is a power input terminal, 115 is a rotation stop, 116 is a bush, 117 is a shaft, 118 is a D cut portion of the shaft 117, and 119 is the clutch body 1 Center hole to put the third gear shaft 110, 120 is a portion cut away to lock the rotation stopper 115 of the clutch body.
[0023]
First, the outline of the image forming apparatus according to the present invention will be described. The image forming apparatus according to the present invention uses a driving force from a single motor 12 provided on one surface of a drive plate 22 as shown in FIG. A gear train as shown in FIG. 5 provided on the surface opposite to the mounting surface of the motor 12 when viewed from the drive plate 22 allows a process unit system mainly composed of a photoconductor and a developing device, a fixing / discharge system, A large-diameter process unit driving gear 31 that is configured to be transmitted to a paper feed / transport system and that has the largest load and that is directly driven by a gear 30 provided on the shaft of the motor 12 is arranged. When the transmission loss is reduced and the process unit driving gear 31 having such a large diameter is provided, the driving force is transmitted to and cut off from the registration roller 7 provided near the process unit. The problem that it is difficult to attach the latch directly to the shaft of the registration roller 7 is solved by the fact that the latch 37 is mounted on the drive plate 22 as a registration clutch assembly 27 as shown in FIGS. As shown in FIG. 6, one end of the boss 72 of the registration clutch assembly 27 is held by a hole 74 provided in the base frame 21, and the registration clutch assembly 27 By arranging the solid 27 one stage upstream of the registration roller 7, the third intermediate gear 34 transmitting the driving force to the registration clutch assembly 27 becomes a second intermediate gear 33 transmitting the driving force from the motor 12. And the gear 43 for transmitting the driving force to the other sheet feeding system, and the gear of the registration clutch assembly 27 are arranged at substantially equal intervals. And or vibrate falling axes of A 34 is obtained so as to avoid driving force transmission becomes unstable.
[0024]
By doing so, the process unit drive gear 31 can be a single large-diameter gear, and the shaft of the registration roller 7 can be extended to a position where it meshes with the gear shaft 36 in the registration clutch assembly 27. Therefore, it is necessary to take a costly method such as driving the process unit with a plurality of gears as in the device disclosed in Patent Document 1, or using a plurality of motors as in the device disclosed in Patent Document 2. And the shaft of the registration roller 7 can be shortened by that amount, so that the image forming apparatus can be provided at low cost. Further, the boss 72 at one end of the registration clutch assembly 27 is held by a hole 74 provided in the base frame 21 of the image forming apparatus 20, so that the registration clutch assembly 27 has both ends with the drive plate 22. Although the state protrudes from 22, the driving force can be stably transmitted and cut off without any problem in the driving force transmission accuracy. In addition, since the drive plate 22 is made of metal, even if the clutch constituting the resist clutch assembly 27 becomes hot due to continuous image formation, heat is transmitted to the drive plate 22 and radiated, thereby allowing natural cooling. Promotes overheating of the clutch.
[0025]
1 and 2, an embodiment of an image forming apparatus using a driving force transmission mechanism according to the present invention in order to clarify the positional relationship between a process unit and a drive system in the image forming apparatus according to the present invention. 1 will be described with reference to FIG. 1 which is a conceptual diagram showing the main components of the image forming apparatus and the conveyance path of the recording paper. FIG. 1 is a conceptual diagram for explaining the main components of the image forming apparatus and the conveyance path of the recording sheet. The motor 12 provided on one surface of a drive plate 22 (see FIG. 2) controls the sheet feeding cassette 1. A pickup roller 3 for picking up the stored recording paper 2, a paper feeding roller 4 for feeding out the recording paper 2, an intermediate roller 5, a second paper feeding roller 6 for feeding out recording paper placed in a manual paper feeding unit one by one, The registration roller 7 that corrects the attitude of the recording paper 2 sent thereto and sends the recording paper to a transfer position in accordance with the timing of forming a toner image on the photoconductor 8, is disposed around the photoconductor (image carrier) 8 and the periphery thereof. And a process unit including a charging device, an exposure device, a developing device, and a cleaner (not shown), a fixing roller 10, a discharge roller 11, and the like. Of these, the pickup roller 3, the intermediate roller 5, the second paper supply roller 6, the registration roller 7, the fixing roller 10, and the discharge roller 11 are provided with a paper supply clutch 28 (corresponding to the pickup roller 3) as shown in FIG. An intermediate clutch 26 (corresponding to the intermediate roller 5), a spring clutch 25 (corresponding to the second paper feed roller 6), a registration clutch assembly 27 including the clutch body 61 and the clutch holder 60 (corresponding to the registration roller 7), Further, a fixing clutch, a discharge clutch and the like (not shown) are attached, and a driving force is transmitted and rotated when necessary.
[0026]
Now, when an image forming instruction is received from a control device (not shown), the photoconductor 8 is exposed by an exposure device (not shown) to form a latent image, and the latent image is developed by a developing device (not shown). Thus, a toner image is formed. On the other hand, the recording paper 2 stored in the paper cassette 1 is picked up by the pickup roller 3, sent to the intermediate roller 5 by the paper feed roller 4, and further sent to the registration roller 7. The toner image is transferred to the transfer position at the timing when the toner image is formed on the photoconductor 8 by the registration roller 7, and the toner image on the photoconductor 8 is transferred by the transfer roller 9 to which the bias is applied. The recording paper 2 on which the toner image has been transferred in this manner is sent to a fixing roller 10 to be fixed, and is discharged by a discharge roller 11. That is, the pickup roller 3 picks up the recording paper 2 stored in the paper supply cassette 1 by connecting the paper supply clutch 28 when an image forming instruction is received, and the second paper supply roller 6 When the recording paper 2 is placed and the spring clutch 25 is connected, the recording paper 2 rotates and sends the recording paper 2 to the intermediate roller 5. On the other hand, when the recording paper 2 is fed by the pickup roller 3 and the second paper feeding roller 6, the intermediate roller 5 connects the intermediate clutch 26 to send the recording paper 2 to the registration roller 7, and the registration roller 7 When the registration clutch 27 is engaged at the timing when a toner image is formed on the body 8 and the leading end of the toner image comes to the position of the transfer roller 9, the recording paper 2 is sent to the transfer position.
[0027]
In the present invention, the motor 12 is disposed on one surface of the drive plate 22 as described above, and the shaft of the motor 12 is mounted on the opposite surface where the drive plate 22 is mounted, as shown in FIGS. And a gear train for transmitting the driving force from the gear 30 disposed in the driving force transmission mechanism. For the process unit, a single large-diameter process unit driving gear 31 is provided, and as shown in FIG. 3, the registration roller 7 provided near the process unit is provided with the process gear shown in FIG. The registration clutch assembly 27 including the clutch body 61 and the clutch holder 60 as shown in FIG. 11 is arranged and driven on the drive plate 22 one stage upstream (the motor 12 side) of the gear 37 on the shaft of the registration roller 7. I try to convey the power.
[0028]
Further, one end of the registration clutch assembly 27 can be held by a hole 74 for receiving a boss 72 of the registration clutch assembly 27 provided on the base frame 21 of the image forming apparatus 20 as shown in FIG. As shown in FIG. 5, a third intermediate gear 34 for transmitting the driving force from the motor 12 to the registration clutch assembly 27 includes a second intermediate gear for transmitting the driving force from the motor 12 to the third intermediate gear 34. 33, a clutch gear 35 in the registration clutch assembly 27, and a two-stage gear 43 for transmitting a driving force from the third intermediate gear 34 to another sheet feeding system are arranged at substantially equal intervals, and are configured by a single plate. Even in the case of the drive plate 22, the third intermediate gear 34 is evenly applied from the surroundings so that the third intermediate gear 34 does not fall or vibrate.
[0029]
Further, as apparent from FIGS. 2 and 4, the resist clutch assembly 27 is attached to the drive plate 22 in a close proximity to the motor 12 but independently, and constitutes the resist clutch assembly 27. Since the gear shaft 36 for transmitting the driving force to the registration roller 7 has an outer diameter smaller than that of the clutch gear 35 for transmitting the driving force to the clutch, the registration clutch assembly 27 can be easily attached to and detached from the drive plate 22. As a result, the image forming apparatus can be provided at low cost, and the registration clutch assembly can be easily removed during maintenance or the like.
[0030]
The registration clutch assembly 27 in the image forming apparatus according to the present invention has a clutch body 77 and a boss 72 of a holder 60 of the registration clutch assembly 27, as shown in FIGS. An end 73 of a shaft 75 in the gear shaft 36 integrated 61 is fitted, and a clutch shaft 76 is further fitted into a hole 64 into which the clutch shaft 76 enters, and integrated. 9B, the clutch body 77 and the gear shaft 36 are integrated to form a clutch body 77, an oil protector 78 for preventing oil from entering the clutch body 77, and a motor 12 as shown in FIG. 9B. Gear 35 for transmitting the driving force from the clutch to the clutch main body 77. A gear for transmitting the driving force from the clutch gear 35 by the engagement and disengagement of the clutch, and transmitting the driving force to registration gears 37 and 38 provided on the registration roller 7. The shaft 36, the rotation stop 79 of the clutch body 77, a power input terminal 80 for supplying power to the clutch body 77, and the like.
[0031]
On the other hand, as shown in FIG. 9 (C), the holder 60 has the shape of an inner box of a match box having an open side, so that the twist, which tends to occur when the holder 60 is molded, is less likely to occur. At one end of the short side, the hole 65 of the boss 72 for inserting the end 73 of the shaft 75 in the integrated body 61 of the clutch body 77 and the gear shaft 36 as described above, and the fitted gear shaft 36 are provided. A notch 71 (see FIGS. 7A and 8A) for meshing with the registration gear 37, a hole 64 into which the shaft 76 of the clutch is fitted, and a rotation stopper 79 of the clutch body are provided at the other end. The long side has a notch 66 for inserting a rotation stopper 79 of the clutch body, and a positioning member for positioning the resist clutch assembly 27 when fixing it to the drive play 22. Fixing members 85 and 86 having U-shaped protrusions 62 and 63, beams 87 having a tapered portion 81, a retaining projection 82, and a grip portion 83 and having a long-side wall having a two-stage structure; The bottom plate has a role of releasing heat generated during operation of the clutch, and has a relief hole 70 for releasing the oil protect portion 78 of the clutch 61 to make it compact, and a holder clutch assembly on the back side shown in FIG. 27, a notch 68 for adjusting the attachment / detachment strength of the clutch body 61 at a corner, and a harness processing bracket 84 on the power input terminal 80 side.
[0032]
Among them, the positioning cross-shaped projections 62 and 63 provided on the fixing members 85 and 86 have different lengths. For example, when the registration clutch assembly 27 is attached to the drive plate 22 by groping during maintenance, it is long. Since the short protrusion is inserted after the other protrusion is inserted into the hole, the resist clutch assembly 27 can be easily attached and detached. Further, the beam 87 having the tapered portion 81, the retaining projection 82, and the grip portion 83 has a two-stage structure with the long side wall of the holder 60 and is shorter than the long side wall. ing. As shown in FIG. 10, when the resist clutch assembly 27 is inserted into the drive plate 22 from the left side in the figure, the retaining projection 82 provided on the beam 87 is provided on the drive plate 22. Since the tapered portion 81 is narrowed by the edge of the hole, and when the edge exceeds the retaining projection 82, the retaining projection 82 returns to the position shown in the drawing. 82, the fixing members 85 and 86, and the position regulating projection 69 sandwich the drive plate 22, and the boss portion 72 is held by the hole 74 provided in the base frame 21 as shown in FIG. Even if the resist clutch assembly 27 protrudes from the drive plate 22, the driving force can be transmitted and disconnected accurately and stably. In addition, since the resist clutch assembly 27 is protruded from the drive plate 22 in this manner, heat dissipation is improved, and the holder 60 is made of a material such as inexpensive polyacetal (POM) which does not have much heat resistance. can do.
[0033]
Then, as shown in FIG. 7, the end 73 of the shaft 75 of the integrated body 61 of the clutch body 77 and the gear shaft 36 is fitted into the boss 72 of the holder 60 of the resist clutch assembly 27. Then, the rotation stopper 79 is inserted into the hole 64 in which the shaft 76 of the clutch enters so as to enter the notch 66 while riding over the rotation preventing member 67 provided on the holder 60 and is integrated. Then, as shown in FIG. 10, the integrated resist clutch assembly 27 is inserted into a hole for inserting the resist clutch assembly 27 of the drive plate 22, and first, the positioning cross-shaped projections 62 and 63 are fitted into the corresponding holes. The tapered portion 81 of the beam 87 is formed so that the gear shaft 36 meshes with the registration gear 37 as shown in FIG. 3, and a boss 72 at one end is formed in the base frame 21 as shown in FIG. Push it in so that it fits into 74. Then, the tapered portion 81 of the beam 87 is narrowed, and when the edge of the hole provided in the live plate 22 exceeds the retaining projection 82, the retaining projection 82 returns to the position shown in the drawing. The registration clutch assembly 27 is fixed in such a manner that the drive plate 22 is sandwiched between the retaining projection 82, the fixing members 85 and 86, and the position regulating projection 69. To remove the loaded resist clutch assembly 27 from the drive plate 22, the grip portion 83 of the beam 87 is picked up and the retaining projection 82 is provided on the drive plate 22. By making the width smaller than the width of the hole for inserting the hole, it can be easily removed.
[0034]
Then, the resist clutch assembly 27 mounted on the drive plate 22 in this manner is moved from the gear 30 provided on the shaft of the motor 12 to the first intermediate gear 32, the second intermediate gear 33, The driving force is transmitted to the clutch gear 35 via the third intermediate gear 34, and when the clutch is further engaged, the driving force is transmitted to the large-diameter gear 37a shown in FIGS. The registration roller 7b is driven, and a driving force is transmitted to a registration gear 38 meshing with a small-diameter gear 37b provided coaxially, so that the registration roller 7 is driven.
[0035]
The above is the outline of the image forming apparatus of the present invention having the registration clutch assembly 27 according to the first embodiment. In the image forming apparatus of the present invention, only the registration clutch assembly 27 of such a form is used. Instead, it may be configured using the registration clutch assembly 100 of the second embodiment as shown in FIGS. The registration clutch assembly 100 according to the second embodiment shown in FIGS. 11 to 14 has a tapered portion 81, a retaining projection 82, a grip portion 83, and the like in the holder 60 of the registration clutch assembly 27 described above. The holder 101 can be configured at low cost without using the beam 87 or the cruciform projection for positioning.
[0036]
As shown in FIG. 12, a resist clutch assembly 100 according to the second embodiment is a combination of a holder 101, an integrated clutch and gear 102, and the integrated clutch and gear 102 is Further, as shown in FIG. 13 and FIG. 14, the clutch body 113, the gear shaft 110, the rotation stopper 115, the power input terminal 114, and the like are configured. The clutch body 113 has a bush 116 as shown in FIG. 14A, and a clutch gear 111 for transmitting the driving force from the motor 12 shown in FIG. After covering the main body 113 with an oil protector 112 for preventing oil from entering, and having the configuration as shown in FIGS. 13A and 13B, the driving force is transmitted from the clutch gear 111 by the engagement and disengagement of the clutch. The D-cut portion 118 formed on the shaft 117 of the gear shaft 110 that transmits the driving force to the registration gears 37 and 38 provided on the registration roller 7 is inserted into the center hole 119 of the clutch body 113, as shown in FIG. It is in such a form.
[0037]
On the other hand, as shown in FIG. 12A, the holder 101 has the shape of an inner box of a match box whose one side is open, so that the twist that easily occurs when the holder 101 is molded is less likely to occur. One end of the short side thereof has a hole 109 of a boss 108 for fitting the end of the shaft 117 in the integrated body 102 of the clutch body 113 and the gear shaft 110, and the other end has a D-cut portion of the shaft 117 of the clutch. A notch portion 120 for locking a rotation stop 115 of the clutch body on the long side, and a positioning boss for positioning when the resist clutch assembly 100 is fixed to the drive play 22. 105 and 106 are provided. The bottom plate has a function of releasing heat generated during operation of the clutch, and has a relief hole 107 for releasing the oil protect portion 112 of the clutch 102 to make the clutch compact.
[0038]
Then, the end 200 of the shaft 117 of the integrated body 102 of the clutch body 113 and the gear shaft 110 is fitted into the boss 108 of the holder 101 of the resist clutch assembly 100, and then the D-cut 118 side of the shaft 117 of the clutch is rotated. The stopper 115 is inserted into the hole 104 into which the shaft 118 of the clutch is inserted while being inserted into the cutout portion 120 provided in the holder 101, and integrated as shown in FIG. Then, the integrated resist clutch assembly 100 is inserted into the hole for inserting the resist clutch assembly 100 of the drive plate 22 in the same manner as described in FIG. 10, and the positioning cross-shaped projections 105 and 106 are inserted into the corresponding holes. The gear shaft 110 is engaged with the registration gear 37 as shown in FIG. 3 and the boss 108 at one end is fitted into the hole 74 provided in the base frame 21 as shown in FIG. Push in and fix. By doing so, the resist clutch assembly 100 of the second embodiment can be mounted on the drive plate 22.
[0039]
Then, the resist clutch assembly 100 mounted on the drive plate 22 in this manner is moved from the gear 30 provided on the shaft of the motor 12 to the first intermediate gear 32, the second intermediate gear 33, The driving force is transmitted to the clutch gear 111 via the third intermediate gear 34, and when the clutch is further engaged, the driving force is transmitted from the gear shaft 110 to the registration gears 37 and 38 provided on the registration roller 7 shown in FIG. That is, the registration roller 7 is driven.
[0040]
【The invention's effect】
As described above, according to the present invention, a resist clutch assembly in which a clutch is held by a clutch holder together with a first gear for transmitting driving force from a motor and a second gear for transmitting and disconnecting driving force by the clutch. By arranging the resist clutch assembly at a position that does not interfere with the process unit drive gear and one stage upstream of the resist roller in the drive plate, the process unit drive gear is a single large-diameter gear. In addition, the shaft of the registration roller may be extended to a position where the shaft of the registration roller meshes with the second gear in the registration clutch assembly. There is no need to take costly methods, and the shaft can be shortened accordingly. It is possible to provide an inexpensive forming apparatus.
[0041]
By disposing the registration roller clutch as a registration clutch assembly one stage upstream of the registration roller, the driving force from the motor is transmitted to the first gear in the registration clutch assembly via the intermediate gear. The intermediate gear includes a gear for transmitting the driving force from the motor to the intermediate gear, a first gear, and a third gear for transmitting the driving force from the intermediate gear to another sheet feeding system at substantially equal intervals. With this arrangement, even in the case of a drive plate composed of a single plate, a force is uniformly applied to the intermediate gear from the periphery, so that the driving force can be transmitted stably without the gear shaft falling or vibrating. .
[0042]
Further, by providing the image forming apparatus with a receiving hole for holding one end of the shaft portion of the second gear in the resist clutch assembly, the resist clutch assembly is held by both the drive plate and the image forming apparatus main body. In other words, even if the resist clutch assembly protrudes from the drive plate, the driving force can be transmitted and disconnected accurately and stably.
[0043]
Further, the second gear has an outer diameter smaller than that of the first gear, and the resist clutch assembly is detachable from the drive plate while holding the second gear, thereby improving the assemblability. As a result, the image forming apparatus can be provided at low cost, and the registration clutch assembly can be easily removed for maintenance or the like.
[0044]
In addition, since the drive plate is made of metal, even if the temperature of the registration roller clutch becomes high due to continuous image formation, heat is transmitted to the metal drive plate and radiated. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram for explaining main components of an image forming apparatus according to the present invention and a conveyance path of a recording sheet.
FIG. 2 is a side view of the image forming apparatus according to the present invention as viewed from a driving force transmission mechanism side without an outer cover.
FIG. 3 is a diagram showing a positional relationship between a gear train and a registration roller constituting a driving force transmission mechanism in the image forming apparatus of the present invention.
FIG. 4 is a diagram illustrating a positional relationship between a gear train and a registration clutch that constitute a driving force transmission mechanism in the image forming apparatus of the present invention.
FIG. 5 is a plan view of a gear train constituting a driving force transmission mechanism in the image forming apparatus of the present invention.
FIG. 6 is a view showing a receiving hole for holding one end of a shaft portion of a gear in a registration clutch assembly provided on a base frame of the image forming apparatus according to the present invention.
FIG. 7 is a plan view (A) and a rear view (B), and a left side view (C) and a right side view (D) of the first embodiment of the registration clutch assembly of the image forming apparatus according to the present invention. .
FIG. 8 is a rear perspective view (A) and a plan perspective view (B) of the first embodiment of the registration clutch assembly of the image forming apparatus according to the present invention.
FIG. 9 is a rear perspective view (A) and a plan perspective view (C) of the clutch holder in the first embodiment of the registration clutch assembly of the image forming apparatus according to the present invention, and a view showing the registration clutch body (B). ).
FIG. 10 is a view showing a state in which the registration clutch assembly according to the present invention is mounted on a drive plate in the first embodiment.
FIG. 11 is a perspective view of a second embodiment of the registration clutch assembly in the image forming apparatus of the present invention.
FIG. 12 is a perspective view (A) of a clutch holder and a perspective view (B) of a clutch body in a second embodiment of the registration clutch assembly in the image forming apparatus of the present invention.
FIGS. 13A and 13B are perspective views (A) and (B) of a clutch main body and a gear shaft (C) of a registration clutch assembly in a second embodiment of the image forming apparatus of the present invention.
FIG. 14 is a perspective view (A) of the second embodiment of the registration clutch assembly of the image forming apparatus of the present invention, in which a gear assembly of a clutch body is removed, and a view (B) of the gear assembly as seen from the back.
[Explanation of symbols]
7 Registration roller
22 Drive plate
23 Control Box
27 Registration clutch assembly
30 Gears provided on the drive shaft of the motor
31 Process unit drive gear
32 1st intermediate gear
33 Second intermediate gear
34 Third intermediate gear
35 clutch gear
36 gear shaft
37, 38 Registration gear
39-42 Gear for transmitting driving force to fixing roller

Claims (5)

A drive plate composed of a single sheet of gear train that transmits driving force to a process unit system mainly composed of a photoconductor and a developing device, a fixing / discharge system, a paper feed / transport system, etc. by a single motor. And a registration roller that drives the recording paper to be fed at a predetermined timing to a transfer position of the toner image formed on the photoconductor by a clutch that transmits and disconnects the driving force from the gear train. ,
The clutch is a resist clutch assembly held by a clutch holder together with a first gear for transmitting a driving force from a motor to the clutch, and a second gear for transmitting and disconnecting the driving force by the clutch. An image forming apparatus, wherein a clutch assembly is disposed at a position not interfering with a process unit drive gear and one stage upstream of the registration roller in the drive plate. A driving force from a motor is transmitted to the first gear in the registration clutch assembly via an intermediate gear, and a fourth gear for transmitting the driving force from the motor to the intermediate gear is provided to the intermediate gear. 2. The image forming apparatus according to claim 1, wherein the first gear and a third gear for transmitting a driving force from the intermediate gear to another sheet feeding system are arranged at substantially equal intervals. . 2. The image forming apparatus according to claim 1, further comprising a receiving hole that holds one end of a shaft portion of a second gear in the registration clutch assembly on a main body side of the image forming apparatus. 3. 2. The device according to claim 1, wherein the second gear has an outer diameter smaller than that of the first gear, and the resist clutch assembly is detachable from the drive plate while holding the second gear. The described image forming apparatus. The image forming apparatus according to claim 1, wherein the drive plate is made of metal.

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