JP6195151B2 - Speed conversion mechanism and image forming apparatus - Google Patents

Description

  The present invention relates to a speed conversion mechanism having a clutch mechanism for drivingly connecting / disconnecting a rotational driving force of a driving source to a rotated body, and an image forming apparatus including the speed conversion mechanism.

Conventionally, speed conversion mechanisms having various configurations are known as a speed conversion mechanism having a clutch mechanism capable of connecting and disconnecting a drive source to a driven body (driven system) during a rotation operation of the drive source. ing.
For example, Patent Document 1 describes an image forming apparatus provided with the following planetary gear clutch mechanism (planetary gear clutch mechanism) as a speed conversion mechanism having a clutch mechanism. The planetary gear clutch mechanism is provided with a solenoid as a second drive source for driving a switching means for driving connection and disconnection from the first drive source for driving the driven system to the driven system. An input-side internal gear (member with internal gear), a planetary gear meshing with the internal gear (planetary gear), a sun gear meshing with the planetary gear (sun gear member), and an output-side planetary gear And a planet carrier for holding (planet gear holding member). The sun gear that is drivingly connected to the first drive source via the internal gear and the planetary gear is driven and connected to a ratchet portion (constraint portion) that is a first rotation restricting member having a protrusion. It is provided to rotate.

  In this planetary gear clutch mechanism, the rotational driving force input to the internal gear on the input side is the output side only when the ratchet portion that rotates integrally with the sun gear is restricted in rotation (hereinafter referred to as the fixed state). The function of the planetary gear mechanism that is driven and transmitted to the planetary carrier is obtained. That is, it is in a drive-coupled state. Conversely, in the rotation restriction release state (hereinafter referred to as the fixed release state) in which the ratchet part has been released from rotation restriction, the function of the planetary gear mechanism in which the rotational driving force input to the internal gear is transmitted to the planet carrier. Cannot be obtained, resulting in a blocked state.

  From the description of FIG. 2 of Patent Document 1, it is considered that the switching means for switching between the drive-coupled state and the disconnected state is configured as follows. The switching means includes a restricting arm (switching lever) that is a rotatable first restricting member having a claw at the tip, and a flapper type solenoid that generates a suction force when the second drive source is turned on. And a tension spring and a solenoid case for holding them. When the solenoid power is turned off, the regulating arm is rotated by the tension of the tension spring, and the claw portion engages with the protrusion of the ratchet portion to be fixed, and the planetary clutch mechanism is driven and connected. . Conversely, when the solenoid power is turned on, the restricting arm is attracted to the solenoid side, its claw portion is separated from the protrusion of the rotation restricting member, and the fixed clutch is released, and the planetary clutch mechanism is disconnected. Become.

  However, in the planetary clutch mechanism described in Patent Document 1, the second drive source is always used to cut off the transmission of the rotational driving force from the first drive source to the driven system while the first drive source is being driven. I have to energize the solenoid. Since it is necessary to energize in this way, the energization time of the solenoid becomes longer, and the possibility that the solenoid temperature rises abnormally and breaks down increases. In order to suppress the temperature rise of the solenoid, it is necessary to reduce the current flowing through the solenoid coil of the solenoid. To reduce the current and generate the desired stroke and force in the solenoid, the number of turns of the electromagnetic coil is increased. Inevitably, the solenoid becomes larger. And even if the current to be energized to the solenoid can be reduced to a current that can keep the temperature of the solenoid within a range that does not rise abnormally, if the energized time is long, the power consumption will increase. was there.

  The present invention has been made in view of the above problems, and an object thereof is to provide the following speed conversion mechanism. Miniaturization of the second drive source that switches the drive connection and disconnection between the driven body and the first drive source that drives the driven body by operating the first regulating member that regulates the rotation of the first driven regulating member. And a speed conversion mechanism including a clutch mechanism capable of energy saving.

To achieve the above object, an invention according to claim 1, Oite the driving force of the first drive source to the speed conversion mechanism having a clutch mechanism for transmitting or blocking the driven member, the clutch mechanism, A planetary gear mechanism including a sun gear, a planetary gear, a planet carrier that rotatably holds the planetary gear, and an internal gear, and any one of the sun gear, the planet carrier, and the internal gear is driven. A coupled first rotation restricting member, a first restricting member capable of contacting or retracting the first rotation restricting member to rotate or release the rotation restriction of the first rotation restricting member; A second drive source that operates the first restriction member, and the clutch mechanism restricts rotation of the first rotation restriction member by contact of the first restriction member with the first rotation restriction member. , Through the other than the one The driving force of the driving source is transmitted to the driven body, or the rotation restriction of the first rotation restriction member is released by retracting the first restriction member with respect to the first rotation restriction member, and the one In the idling state, the transmission of the driving force of the first driving source to the driven body is interrupted, and a cam is used for the driving train that transmits the driving force from the second driving source to the first regulating member. It is characterized by this.

  The present invention operates the first regulating member that regulates the rotation of the first rotation regulating member, and switches the driving connection between the driven body and the first drive source that drives the driven body, and the second drive that switches between the driving and blocking. A speed conversion mechanism including a clutch mechanism capable of reducing the size of the source and saving energy can be provided.

1 is an overall schematic explanatory diagram of a printer that is an image forming apparatus according to Embodiment 1. FIG. FIG. 4 is an explanatory diagram of a driving gear train of a photosensitive member and a developing roller when an image forming unit according to a reference example is rotated forward. The perspective explanatory drawing of the planetary gear clutch mechanism which concerns on a reference example. Explanatory drawing of the operation principle of a planetary gear clutch mechanism. Explanatory drawing of the switching means using the solenoid which concerns on a reference example. Explanatory drawing of the meshing surface at the time of the protrusion part of the ratchet part which concerns on a reference example, and the nail | claw part of a control arm mesh | engage. FIG. 3 is an explanatory diagram of a driving gear train of a photosensitive member and a developing roller when the image forming unit according to the first embodiment is rotated forward. FIG. 3 is an explanatory perspective view of the planetary gear clutch mechanism according to the first embodiment. Explanatory drawing of the drive connection and interruption | blocking operation | movement by the 1st ratchet part and 1st control arm which concern on Embodiment 1. FIG. Explanatory drawing of the structure which rotates the cam which rotates the 1st control arm which concerns on Embodiment 1, and a cam. The graph which shows the locus | trajectory of the boss | hub part of the 1st control arm which moves by rotation of the cam which concerns on Embodiment 1. FIG. FIG. 6 is a perspective explanatory view of a planetary gear clutch mechanism according to a second embodiment. Explanatory drawing of the 1st ratchet part and slider part which concern on Embodiment 2. FIG. Explanatory drawing of the drive connection and interruption | blocking operation | movement by the slider part which concerns on Embodiment 2. FIG.

[Embodiment 1]
Hereinafter, as an embodiment in which the present invention is applied to an image forming apparatus (hereinafter, this embodiment is referred to as “Embodiment 1”), an example in which the present invention is applied to an intermediate transfer type tandem color printer (hereinafter, referred to as printer 300). Will be described with reference to the drawings. FIG. 1 is an overall schematic explanatory diagram of a printer 300 that is an image forming apparatus according to the first embodiment.

  First, the overall configuration and operation of the printer 300 according to the first embodiment will be described. As shown in FIG. 1, the printer 300 includes image forming units 10K, M, and C corresponding to four color toners of black (K), magenta (M), cyan (C), and yellow (Y), respectively. , Y are provided. Each image forming unit 10 is arranged so as to come into contact with the driving roller 22, the driven roller 23, which is also a corresponding roller of the secondary transfer roller 25, and the intermediate transfer belt 24 spanned by a plurality of stretching rollers from below. ing.

  Further, the image forming units 10Y, 10C, 10M, and 10K are arranged in this order from the upstream side in the endless movement direction of the intermediate transfer belt 24 (the driven roller 23 side). Each image forming unit 10 is provided with drum-shaped photoreceptors 1K, M, C, and Y, which are latent image carriers corresponding to the respective colors. Around each photoreceptor 1, charging devices 2K, M, C, and Y, developing devices 3K, M, C, and Y, photoreceptor cleaning devices 7K, M, C, and Y are provided.

  In the printer 300, when image information is transmitted from a personal computer or the like, each photoconductor 1 is rotated and each photoconductor 1 is uniformly charged by each charging device 2. Thereafter, the optical writing device 30 disposed below each photoconductor 1 irradiates the surface of each photoconductor 1 with laser light based on image information transmitted from a personal computer or the like to form an electrostatic latent image. To do. The electrostatic latent images are visualized as toner images by attaching toner with the developing devices 3 provided respectively.

  Each color toner image formed on the surface of each photoconductor 1 is opposed to each other through an intermediate transfer belt 24 that moves endlessly in the clockwise direction as the photoconductor 1 rotates counterclockwise in FIG. Is conveyed to the position of the primary transfer roller 21 provided on the surface. Then, the primary transfer bias applied to the primary transfer roller 21 causes primary transfer so that the images are sequentially superposed on the surface of each photoconductor 1 from the surface of the intermediate transfer belt 24 so that the color is transferred onto the intermediate transfer belt 24. A toner image is formed. The color toner image primarily transferred onto the intermediate transfer belt 24 is subjected to a secondary transfer in which the secondary transfer roller 25 is disposed opposite to the driving roller 22 via the intermediate transfer belt 24 by the endless movement of the intermediate transfer belt 24. It is transported to the position.

  Further, the sheet P, which is a recording medium such as transfer paper or an OHP sheet, is conveyed from the sheet feeding device 40 to a conveyance path 41 indicated by a solid line in FIG. 1 in accordance with the timing at which the color toner image is conveyed to the secondary transfer position. Are fed by a plurality of sheet conveying rollers. The paper feeding device 40 is provided below the optical writing device 30. Then, the color toner image is collectively transferred by the secondary transfer bias applied to the secondary transfer roller 25 onto the sheet P conveyed to the secondary transfer position by the registration roller pair 42.

  The sheet P on which the color toner images are collectively transferred is conveyed along the conveyance path 41 to the fixing device 11 provided downstream of the secondary transfer position in the sheet conveyance direction, and the color toner image is formed on the sheet P. It is fixed. Then, the fixed sheet P is discharged from the discharge outlet 43 by the rotation of the discharge roller, and is stacked on the discharge tray 44. Further, the untransferred toner that has not been completely transferred from the photoreceptor 1 to the intermediate transfer belt 24 at the primary transfer position is provided downstream of the primary transfer position of the photoreceptor 1 in the photoreceptor rotation direction. The photosensitive member cleaning device 7 cleans it. The transfer residual toner that could not be completely transferred from the intermediate transfer belt 24 to the sheet P at the secondary transfer position is also cleaned by the intermediate transfer belt cleaning device 26 to prepare for the image formation again.

  Here, when the developing roller 4 and the developer agitating and conveying screws 5 and 6 that are the developer carrying members included in the photosensitive member 1 and the developing device 3 of each image forming unit 10 are rotationally driven, individually by a driving source. A certain drive motor may be provided. However, the printer 300 according to the first embodiment is configured to transmit the rotational driving force from one driving motor to the plurality of image forming units 10 in consideration of cost, consumed energy, and the like. Specifically, the image forming units 10Y, 10C, and 10M that are operated during color image formation share one drive motor, and the image forming unit 10K that supports the frequently used black uses one drive motor. Yes. In each image forming unit 10, the developing roller 4 and the developer agitating and conveying screws 5 and 6 included in the photosensitive member 1 and the developing device 3 are configured to transmit a rotational driving force by a driving gear train. Yes. Thus, by configuring the rotational drive system, the printer 300 is reduced in cost and energy saving.

  Further, as in the image forming units 10 of the first embodiment, in the configuration in which the rotating members such as the photosensitive member 1, the developing roller 4 in the developing device 3, the developer stirring and conveying screws 5 and 6 are provided, the photosensitive member 1 However, the deterioration with the operation time of the developing roller 4 tends to progress faster. For this reason, it is desirable to keep the rotation of the developing roller 4 to the minimum necessary. In addition, toner, additives, lubricants, paper dust and other deposits may adhere to the edge of the cleaning blade of the photoconductor cleaning device 7 that cleans the surface of the photoconductor 1 to cause poor cleaning. is there. Therefore, every time a predetermined period has elapsed or every time a predetermined number of times of image formation has been performed, it is necessary to drive the photosensitive member 1 in the reverse rotation direction so as to remove deposits attached to the edge portion of the cleaning blade. is there. Thus, when performing the removal operation | movement of a deposit | attachment, not only the photoreceptor 1 but the developing roller 4 will normally be rotationally driven in a reverse rotation direction.

  Therefore, in the printer 300 of the first embodiment, in each image forming unit 10, the driving gear train of the photosensitive member 1, the developing roller 4 in the developing device 3, and the developer agitating and conveying screws 5 and 6 is branched. Then, a planetary gear clutch mechanism 200 is provided as a clutch mechanism corresponding to bi-directional rotational driving in the driving gear train that transmits the rotational driving force to the developing roller 4 and the developer stirring and conveying screws 5 and 6 in the developing device 3. By configuring in this way, the rotation of the developing roller 4 can be kept to a minimum, and the drive control for removing the deposits on the edge of the cleaning blade can be performed.

Next, the configuration of the planetary gear clutch mechanism 200 that also functions as a speed conversion mechanism including a clutch mechanism that drives the developing roller 4 of each image forming unit 10 provided in the printer 300 of the first embodiment will be described.
As will be described in detail later, the planetary gear clutch mechanism 200 of the first embodiment performs a clutch operation corresponding to bidirectional rotation driving by one planetary gear unit 210 and one switching means 230, that is, one set of planetary gear unit 210. And switching means 230. Conventionally, a planetary gear clutch mechanism that also functions as a speed conversion mechanism, such as a reversing drive device that supports bidirectional rotation drive described in Patent Document 1, to realize clutch operation corresponding to bidirectional rotation drive. A configuration using two is also known. Since the planetary gear clutch mechanism 200 according to the first embodiment can support bidirectional rotational driving with a pair of planetary gear units 210 and switching means 230, the planetary gear unit and the planetary gear unit 200 are similar to the reverse driving device described in Patent Document 1. There is no need to provide two sets of switching means. Therefore, the cost of the planetary gear clutch mechanism can be reduced and the power consumption of a drive source such as a solenoid used for the switching means can be reduced as compared with the reverse drive device described in Patent Document 1.

  However, in recent years, the demand for energy saving has increased more than ever. For this reason, the planetary gear clutch mechanism 200 that transmits the driving force to the developing roller 4 or the like to be driven is made energy-saving only by making the planetary gear unit 210 and the switching unit 230 support bidirectional rotation driving. It has become difficult to meet the demands of computerization. Therefore, the planetary gear clutch mechanism 200 according to the first embodiment is configured to further reduce power consumption by shortening the energization time to the solenoid 231 that is a drive source used for the switching unit 230. In addition, this invention is not limited to the structure of the planetary gear clutch mechanism 200 corresponding to the bidirectional | two-way rotational drive demonstrated below. For example, the present invention can be applied to a planetary gear clutch mechanism corresponding to one-way rotation driving, and power consumption of a driving source such as a solenoid used for the switching means can be reduced.

  First, in order to clarify the characteristic part of the planetary gear clutch mechanism 200 of the first embodiment, a reference planetary gear part 110 and switching means 130 are used as a reference example having substantially the same structure except for the structure related to the characteristic part. A configuration of the planetary gear clutch mechanism 100 corresponding to the bidirectional rotation drive will be described. In the following description, the members that perform the same function in the planetary gear clutch mechanism 200 of the first embodiment and the planetary gear clutch mechanism 100 of the reference example, or the names of the same members will be described using the same terms. Further, with respect to the reference numerals, except for some members, the same two digits are used for the last two digits, and the third digit is “2” for the planetary gear clutch mechanism 200 of the first embodiment. The mechanism 100 will be described individually using “1”.

Further, the drive gear train of each image forming unit 10 provided in the printer 300 of the first embodiment is the same as the reference example, except for the gears engaged with the developing roller drive gear train 90, and the basic configuration is the same. The following reference example will be described.
Since the configuration of each planetary gear clutch mechanism 100 provided in each image forming unit 10 is the same, in the following description, the image forming unit 10K will be described, and symbols K, M, C and Y will be omitted as appropriate.

(Reference example)
A configuration of a planetary gear clutch mechanism 100 that is a reference example of the planetary gear clutch mechanism 200 of the first embodiment will be described with reference to the drawings. FIG. 2 is an explanatory diagram of the drive gear train 70 of the photosensitive member 1 and the developing roller 4 when the image forming unit 10 according to this reference example is rotated forward. Here, FIG. 2 shows a cross section of the planetary gear clutch mechanism 100 as viewed from the side of the internal gear 101 from the ratchet portion 112 that is drivingly connected to the sun gear 111 and rotates integrally. In the drawing, the outer shapes of the output gear 116, the photosensitive member 1, and the developing roller 4 arranged on the front side are also indicated by broken lines.

  3 is a perspective explanatory view of the planetary gear clutch mechanism 100 according to this reference example, FIG. 4 is an explanatory view of the operating principle of the planetary gear clutch mechanism, and FIG. 5 uses the solenoid 131 according to this reference example. Explanatory drawing of the switching means 130. FIG. FIG. 6 is an explanatory view of the meshing surface when the projection 113 of the ratchet 112 and the claw 125 of the restriction arm 121 according to this reference example mesh with each other, and FIG. 6A shows the meshing state in the forward rotation direction. FIG. 6B shows the meshing state in the reverse rotation direction. Here, with respect to the gear portions in each of the above drawings excluding the protrusion 113 of the ratchet portion 112, the tooth profile is omitted and only the reference pitch circle is described.

  Further, in the following description, unless otherwise specified, with respect to the rotation direction of each gear and the rotating body such as the intermediate transfer belt 24, the rotation direction during image formation is the normal rotation direction, and the rotation direction is opposite to that during image formation. Is called the reverse rotation direction. Further, when it is necessary to indicate the absolute rotation direction instead of the relative rotation direction, the clockwise direction or the counterclockwise direction in each drawing is simply referred to as a clockwise direction or a counterclockwise direction. Moreover, in FIG. 1, FIG. 5, the part which becomes a hidden line originally is described with the continuous line so that the shape of each spring may be understood easily.

  First, the drive gear train 70 of the image forming unit 10 will be described with reference to FIG. 2, taking as an example the case where the photosensitive member 1, the developing roller 4, and the developer agitating and conveying screws 5 and 6 are rotated in the forward rotation direction. The drive gear train 70 includes a photoconductor drive gear train 80 on the left side of the drive gear 71 formed directly on the output shaft of a drive motor (not shown) as a first drive source, and a developing roller drive gear on the right side of the diagram. Branching to column 90. Here, the photosensitive member driving gear train 80 constitutes a driving train for rotationally driving the photosensitive member 1 as a driven member, and the developing roller driving gear train 90 is a driving for rotationally driving the developing roller 4 as a driven member. Constitutes a column. A planetary gear clutch mechanism 100 is provided in the developing roller drive gear train 90. Further, screw gears (not shown) that respectively rotate the developer stirring and conveying screws 5 and 6 (not shown) are provided downstream of the developing roller drive gear 94 that rotates the developing roller 4 in the driving force transmission direction. .

  Here, the image forming unit 10K is different from the image forming units 10Y, 10C, and 10M corresponding to other colors in the following points. For each image forming unit, a driving gear that transmits driving force to the photosensitive member driving gear train 80 and the developing roller driving gear train 90 is connected to motor driving gear trains (not shown) of the image forming units 10Y, 10C, and 10M. This is a driving gear (not shown). However, the configurations of the photosensitive member driving gear train 80 and the developing roller driving gear train 90 that transmit the rotational driving force to the photosensitive members 1 of the image forming units 10Y, 10C, and 10M are the same except for the above differences.

  The photoconductor drive gear train 80 of each image forming unit 10 includes a first photoconductor gear 81 that meshes with the drive gear 71 from the left side in the drawing, and a photoconductor drive gear 82 that meshes with the first photoconductor gear 81 from the lower left side in the drawing. I have. Further, the developing roller driving gear train 90 includes a first developing roller gear 91 that meshes with the driving gear 71 from the right side in the drawing, and a planetary gear clutch mechanism 100 that has an input gear portion that meshes with the first developing roller gear 91. . A second developing roller gear 92 that meshes with the output gear 116 of the planetary gear clutch mechanism 100 and a third developing roller gear 93 that meshes with the second developing roller gear 92 are also provided. Further, a developing roller driving gear 94 that meshes with the third developing roller gear 93 and rotationally drives the developing roller 4 is also provided. Here, in the case where the external gear 103 formed on the outer periphery of the internal gear 101 that is the input gear of the planetary gear clutch mechanism 100 and the output gear 116 of the external tooth are in a driving connection state, It is configured to rotate in the same direction even if it is rotationally driven.

  As shown in FIG. 2, when the photosensitive member 1 and the developing roller 4 are rotated in the forward rotation direction in a state where the planetary gear clutch mechanism 100 is drivingly connected, the driving gear 71 rotates counterclockwise. When the driving gear 71 rotates counterclockwise, in the photosensitive member driving gear train 80, the photosensitive member driving gear 82 also rotates counterclockwise, which is the positive rotation direction, via the first photosensitive member gear 81. In the developing roller drive gear train 90, the first developing roller gear 91 rotates clockwise, and the internal gear 101 that is the input gear of the planetary gear clutch mechanism 100 rotates counterclockwise. Then, the output gear 116 of the planetary gear clutch mechanism 100 rotates counterclockwise, which is the normal rotation direction. The counterclockwise rotation of the output gear 116 is transmitted via the second developing roller gear 92 and the third developing roller gear 93, and the developing roller driving gear 94 rotates clockwise in the forward rotation direction.

  When the planetary gear clutch mechanism 100 is disconnected, the counterclockwise rotational driving force of the internal gear 101 is not transmitted to the output gear 116 of the planetary gear clutch mechanism 100. Therefore, the output gear 116 does not rotate in either direction. That is, when the planetary gear clutch mechanism 100 is in the disconnected state, when the drive motor is driven to rotate in the forward rotation direction, the photoreceptor 1 is driven to rotate in the forward rotation direction. However, the developing roller 4 and the developer stirring and conveying screws 5 and 6 in the developing device 3 do not rotate in either direction. In the reverse rotation direction as well, the respective rotations are performed in the same manner in the drive-coupled state and the disconnected state of the planetary gear clutch mechanism 100.

  Next, the planetary gear clutch mechanism 100 will be described in detail. As shown in FIG. 3, the planetary gear clutch mechanism 100 used in the printer 300 of the present reference example includes a planetary gear unit 110 having a planetary gear mechanism, an output gear 116, and a ratchet unit 112 that is a first rotation restricting unit. I have. Further, a rotation restricting portion 120 having a restricting arm 121 that is a first restricting member, and a switching means 130 that provides an operation of switching the engagement state and the non-engagement state of the restriction arm 121 are also provided.

  The planetary gear unit 110 of the planetary gear clutch mechanism 100 is an planetary carrier that is an internal gear 101 that is an input gear, three planetary gears 105, and a member that holds each planetary gear 105 rotatably and revolving. And a carrier 104. A sun gear 111 that meshes with each planetary gear 105 is also provided. Further, the carrier 104 holding each planetary gear 105 is connected so that the carrier 104 and the output gear 116 that transmits the rotation of the carrier 104 to the drive unit on the downstream side are driven and connected to rotate integrally. An output shaft 109 is also provided. Further, the sun gear 111 is provided with a ratchet portion 112 that is a rotation restricting portion so as to be driven and connected (in a drive-connected state). The internal gear 101, the carrier 104, the sun gear 111, the ratchet portion 112, the output shaft 109, and the output gear 116 are arranged coaxially.

  Here, the planetary gear unit 110 performs the following rotational motion. While the rotational driving force is transmitted to the external gear portion 103 formed on the outer periphery of the internal gear 101 via the first developing roller gear 91 (see FIG. 2), the internal gear portion of the internal gear 101. Each planetary gear 105 meshed with 102 always rotates. However, the carrier 104 holding each planetary gear 105 rotates only under certain conditions. That is, the planetary gear clutch mechanism 100 has a drive coupling function that enables the drive transmission function of the planetary gear mechanism that transmits drive to the downstream drive unit of the planetary gear unit 110 under certain conditions, and under other conditions. And a shut-off function for shutting off drive transmission to the downstream drive unit. For this reason, the output gear 116 also rotates only under certain conditions. Next, the drive coupling function and the cutoff function of the planetary gear clutch mechanism 100 will be described.

  First, the drive transmission method of the planetary gear unit 110 will be described. As shown in FIG. 4, the drive transmission unit of the planetary gear unit 110 mainly includes three types of gears, that is, the internal gear unit 102 of the internal gear 101, the planetary gear 105, and the sun gear 111. . The elements that can rotate coaxially with the rotation shaft of the internal gear 101 include the internal gear 101, the carrier 104 that holds the planetary gear 105 so as to rotate and revolve, and the sun gear 111. And the planetary gear part 110 becomes effective for the drive transmission function for the first time by allocating the rotatable input, the output, and the fixed to which the rotation is restricted to the three rotatable elements.

  Therefore, in the planetary gear unit 110 of this reference example, the drive transmission function of the planetary gear mechanism is validated by assigning the input to the internal gear 101, the output to the carrier 104, and the sun gear 111 in a fixed manner. Then, the sun gear 111 assigned to the fixed state is switched to a fixed state in which the rotation is restricted, thereby bringing the planetary gear unit 110 into a drive transmission state in which the rotational driving force can be transmitted to the downstream drive unit. In addition, by switching to the rotatable fixed release state, the drive transmission function of the planetary gear mechanism is lost, that is, the carrier 104 stops rotating, and the rotation drive force is not transmitted to the downstream drive unit. .

  An external gear 103 is formed coaxially on the outer periphery of the internal gear 101 and meshes with the first developing roller gear 91 shown in FIG. 2 to transmit the rotational driving force to the internal gear 101. Further, the carrier 104 has a reference side plate 106 on the side away from the output gear 116, a pin 108 that is supported by the reference side plate 106 and rotatably supports the planetary gear 105, and an end side plate that supports the other end side of the pin 108. 107 (see FIG. 3). An output shaft 109 that transmits a rotational driving force to the output gear 116 is connected to the reference side plate 106. The cross section of the portion of the output shaft 109 that is fitted to the output gear 116 is provided with a rotation preventing process so that the rotational driving force can be reliably transmitted to the output gear 116.

  In addition, the end side plate 107 is provided with a hole for allowing the sun gear 111 to face in a rotatable state. The ratchet 112 (see FIG. 3) is coaxially driven and connected to the sun gear 111 and the sun gear 111, and is provided with a hole through which the output shaft 109 passes in a rotatable state. ing. Next, a specific configuration in which the sun gear 111 is switched between a fixed state in which rotation is restricted and a free fixed release state, that is, a specific configuration in which the planetary gear clutch mechanism 100 is switched between a drive connection state and a cutoff state. A detailed configuration will be described.

  As shown in FIG. 5, the ratchet portion 112, which is driven and connected coaxially with the sun gear 111 and is provided to rotate integrally, meshes with the claw portion 125 provided on the restriction arm 121. A plurality of protrusions 113, which are a plurality of protrusions, are provided at equal intervals over the entire circumference. Further, the rotation restricting portion 120 that restricts the rotation of the sun gear 111 rotates the restricting arm 121 and the restricting arm 121 which are first restricting members provided with claw portions 125 that mesh with any one of the protrusions 113 of the ratchet portion 112. It is comprised from the support shaft 123 supported so that it is possible. The restricting arm 121 has an arm output portion 122 on the distal end side where the claw portion 125 is provided from the support shaft 123, and an arm input portion 124 on the opposite side of the protrusion from the support shaft 123.

  The switching means 130 for switching between a fixed state in which the claw portion 125 provided on the arm output portion 122 of the rotation restricting portion 120 is engaged with the protruding portion 113 of the ratchet portion 112 and a fixed release state in which the claw portion 125 is separated is included in the solenoid 131 and the compression spring 136. It has. The solenoid 131 is provided with a plunger 133 which is a cylindrical member that moves substantially horizontally in FIG. An engagement pin 134 that passes through a long hole (not shown) provided in the arm input portion 124 of the restriction arm 121 is provided at the tip of the plunger 133, and the restriction arm 121 is supported by the support shaft 123 by the movement in the substantially horizontal direction. Is rotated about the rotation center.

  A compression spring 136 is provided on the outer periphery of the plunger 133 of the solenoid 131. An end ring 135 is provided on the engagement pin 134 side of the plunger 133 at a position that does not hinder the rotation of the arm input portion 124 of the restriction arm 121 to restrict one end side of the compression spring 136, and the other end side is a solenoid. It is regulated by a solenoid case 132 that holds 131. By the reaction force of the compression spring 136, the engaging pin 134 of the arm input portion 124 is configured to be pushed out in the right direction (arrow A direction) in FIG.

  By configuring the switching means 130 in this way, the plunger 133 moves to the right in FIG. 5 by the action of the compression spring 136 when the power of the solenoid 131 is turned off. Along with this movement, the regulating arm 121 rotates about the support shaft 123 and rotates counterclockwise (arrow C direction) in the figure. Then, any one side surface of the claw portion 125 provided at the tip of the arm output portion 122 comes into surface contact with any one side surface of the projection 113 of the ratchet portion 112 to be in a fixed state. Further, when the power of the solenoid 131 is turned on, the plunger 133 moves in the left direction (arrow B direction) in FIG. Along with this movement, the regulating arm 121 rotates about the support shaft 123 and rotates clockwise in the figure (arrow D direction), and the claw portion 125 provided at the tip of the arm output unit 122 has a ratchet portion. It is separated from the protrusion 113 of 112 and it will be in a fixed release state.

  6 (a) and 6 (b), in the planetary gear clutch mechanism 100 of the present reference example, any one of the protrusions 113 provided in the ratchet part 112 and the claw part 125 provided in the restriction arm 121 are provided. The surface where the two mesh with each other varies depending on the rotational direction of the rotational driving force for driving transmission. Here, FIG. 6A shows the meshing state in the forward rotation direction, and FIG. 6B shows the meshing state in the reverse rotation direction. With this configuration, the planetary gear clutch mechanism 100 of the present reference example has a bi-directional rotational driving force with respect to the developing roller driving gear train 90 corresponding to the bi-directional rotational driving of the driving motor that is a driving source. Can be transmitted, or the rotational driving force can be interrupted. Therefore, the cost of the planetary gear clutch mechanism can be reduced and the power consumption of a drive source such as a solenoid used for the switching means can be reduced as compared with the reverse drive device described in Patent Document 1.

However, in order to maintain the planetary gear clutch mechanism 100 in the disconnected state while the drive motor that is the first drive source is being driven, the solenoid 131 that is the second drive source must always be energized. Since it is necessary to energize in this way, the energization time to the solenoid 131 is prolonged, and the possibility that the temperature of the solenoid 131 rises abnormally and breaks down increases. In order to suppress the temperature rise of the solenoid 131, it is necessary to reduce the current flowing through the electromagnetic coil of the solenoid 131. To reduce the current and generate a desired stroke and force in the solenoid, the number of turns of the electromagnetic coil is reduced. The solenoid 131 is inevitably increased in size. Even if the current supplied to the solenoid 131 can be reduced to a value that can keep the temperature of the solenoid 131 within a range where the temperature of the solenoid 131 does not rise abnormally, if the time for supplying the solenoid 131 is increased, the power consumption increases. There was a problem that.
Therefore, in the planetary gear clutch mechanism 200 of the first embodiment, the energization time to the solenoid 231 that is the second drive source used for the switching unit 230 is shortened, and the solenoid 231 can be reduced in size and energy can be saved. It was.

  Next, the configuration of the planetary gear clutch mechanism 200 including the clutch mechanism that is the speed conversion mechanism of the first embodiment will be described with reference to the drawings. The planetary gear clutch mechanism 100 of the reference example described above and the planetary gear clutch mechanism 200 of the first embodiment are the same in basic operation and configuration except for the configuration related to the following points. Detailed operations and configurations will be omitted as appropriate. In the planetary gear clutch mechanism 200 of the first embodiment, the planetary gear clutch mechanism 100 of the reference example is a first restriction member that is a first restriction member that restricts rotation of the first ratchet portion 212 that is a first rotation restriction member. The point which concerns on the structure of the switching means 230 which operates the arm 221 differs. Further, with the arrangement of the switching means 230 described later in detail, the difference is that the output shaft 209 and the output gear 116 of the planetary gear clutch mechanism 200 are provided on the opposite side of the switching means 230 via the internal gear 201.

  Here, FIG. 7 is an explanatory diagram of the drive gear train 70 of the photosensitive member 1 and the developing roller 4 during the forward rotation of the image forming unit 10 according to the first embodiment, and FIG. 8 is a planet according to the first embodiment. 3 is a perspective explanatory view of a gear clutch mechanism 200. FIG. FIG. 9 is an explanatory diagram of the drive coupling and blocking operation by the first ratchet part 212 and the first regulating arm 221 according to the first embodiment, and FIG. 9A is an explanatory diagram of the blocking operation, and FIG. ) Is an explanatory diagram of the connecting operation.

  FIG. 10 is an explanatory diagram of a cam 241 that rotates the first restricting arm 221 according to the first embodiment and a configuration that rotates the cam 241. 10A rotates the first restricting arm 221 until the state where the rotation of the first ratchet portion 212 is restricted, and FIG. 10B rotates the operation until the state where the rotation of the first ratchet portion 212 is released. ) And the configuration for rotating the cam 241. FIG. 11 is a graph showing the trajectory of the boss portion 226 of the first restriction arm 221 that moves due to the rotation of the cam 241 according to the first embodiment. Here, with respect to the gear portions in each of the drawings excluding the protrusions of the ratchet portions, the tooth profile is omitted as in the above-described reference example, and only the reference pitch circle is described.

As shown in FIG. 7, the basic configuration of the drive gear train 70 of the photosensitive member 1 and the developing roller 4 provided with the planetary gear clutch mechanism 200 of the first embodiment is the same as that of the reference example. In FIG. 7, only the first ratchet portion 212 and the first restricting arm 221 are shown, and the main configuration of the switching unit 230 is not shown because the drawing is complicated.
Further, as shown in FIG. 8, the planetary gear clutch mechanism 200 of the first embodiment is connected to the planetary gear clutch mechanism 100 of the reference example and the switching means 230, the output shaft 209, and the output shaft 209 which are characteristic parts. Only the point relating to the output gear 216 is different. Accordingly, similar operations and configurations will be omitted as appropriate.

  Also in the planetary gear clutch mechanism 200 of the first embodiment, it is necessary to assign any of input, output, and fixed functions to the sun gear 211, the carrier 204, and the internal gear 201 of the planetary gear unit 210. Therefore, a fixed function is assigned to the sun gear 211, and is fixedly connected to the sun gear 211 so as to restrict the rotation of the first ratchet portion 212, which is a first rotation restricting member provided to rotate integrally. The driving force transmission function of the planetary gear mechanism is obtained. In addition, the driving force transmission function of the planetary gear mechanism is lost in the unlocked state where the rotation of the first ratchet portion 212 is not restricted. The planetary gear clutch mechanism 200 of the first embodiment is also a clutch mechanism that is compatible with bidirectional rotational drive, like the planetary gear clutch mechanism 100 of the reference example.

  Further, the rotation restricting portion 220 that restricts the rotation of the sun gear 211 rotates the first restricting arm 221 and the first restricting arm 221 provided with the claw portion 225 that meshes with any of the protrusions 213 of the first ratchet portion 212. It comprises a support shaft (not shown) that can be supported. Here, the support shaft that rotatably supports the first restriction arm 221 is fixed to a bracket (not shown) fixed to the apparatus main body.

  As shown in FIG. 8, in the planetary gear unit 210 of the planetary gear clutch mechanism 200 of the first embodiment, unlike the reference example, an output shaft 209 is provided on the reference side plate 206 on the lower side in FIG. It connects to the output gear 216 arrange | positioned under 201. FIG. The output shaft 209 has a hole through which the support shaft 215 is passed. The support shaft 215 transmits the driving force of the sun gear 211, the cam 241, and the solenoid 231 that is the second drive source to rotate the cam 241 by a predetermined angle and regulate the position after the rotation. The restricting member is rotatably supported. The other end side of the support shaft 215 is supported by a bracket (not shown) fixed to the casing of the printer 300. In addition, the sun gear 211 is connected to the first ratchet portion 212 in the same manner as in the reference example so as to rotate integrally.

  A feature of the planetary gear clutch mechanism is that the fixing and releasing operations are easy. Also in the planetary gear clutch mechanism 200 of the first embodiment, a bracket (not shown) that holds a shaft member that rotatably supports and holds the cylindrical portion 223 of the first restriction arm 221 is assembled and fixed to the main body. For this reason, as shown in FIGS. 9A and 9B, the claw 225 provided on the arm output portion 222 of the first restriction arm 221 is engaged with the protrusion 213 of the first ratchet portion 212. Similarly to the reference example, the first ratchet portion 212 can be restricted or released. Here, the 1st control arm 221 is comprised by the substantially L shape which made the breakage the cylindrical part 223 which lets a shaft member pass, and the nail | claw part 225 is provided in the one end part of the arm output part 222 which comprises one side. It has been. Further, at one end of the arm input portion 224 constituting the other side, a cylindrical boss portion 226 fitted into a groove portion 242 formed on the upper surface in FIG. 8 of the cam 241 described later is shown in FIG. It is provided so as to extend toward the middle downward.

Further, in FIG. 8, the arm output portion 222 in which the claw portion 225 meshes with the projection portion 213 of the first ratchet portion 212 provided below, and the arm in which the boss portion 226 is fitted in the groove portion 242 of the cam 241 provided above. The input unit 224 is connected to the cylindrical unit 223 at different levels.
As shown in FIG. 9 (a), when the claw portion 225 of the first restricting arm 221 is not engaged with the protruding portion 213 of the first ratchet portion 212, it does not rotate because there is a unit load on the output side. The first ratchet portion 212 idles. On the other hand, as shown in FIG. 9B, when the claw portion 225 of the first restricting arm 221 is engaged with the protrusion 213 of the first ratchet portion 212, the first ratchet portion 212 and the sun gear 211 are in a rotationally fixed state. It becomes. Then, the rotational driving force of the driving motor is output to the driven system side through the planetary gear unit 210, and is in a drivingly connected state.

  8 and 10 (a) and 10 (b), a plurality of claw portions 244 are formed on the upper surface of the cam 241 provided above the first ratchet portion 212 in FIG. The second ratchet portion 243 is coaxially driven and connected, and is provided to rotate integrally. Further, a groove portion 242 is formed on the upper surface of the cam 241 so as to fit the boss portion 226 of the first restricting arm 221 functioning as a follower. As shown in the graph of FIG. 11, the groove portion 242 has an output displacement from the center of the support shaft 215 that is the rotation center of the cam 241 at the center position of the cylindrical boss portion 226 every 45 [°]: r [ mm] is switched to two boss part positions a and boss part positions b.

  Further, the boss part position a and the boss part position b are set so that the output displacement: r [mm] is substantially constant within the range of the predetermined rotation angle of the cam 241, and the boss part position a is the first restriction. The boss portion position b corresponds to the fixed state of the arm 221, and the boss portion position b corresponds to the fixed state. By configuring the cam 241 in this manner, the driving force of the solenoid 231 is maintained to maintain the position of the boss 226 that is a follower that contacts the groove 242 of the cam 241 after the first restricting arm 221 is operated. It can be configured not to be required. Therefore, the solenoid 231 can be configured not to be energized to maintain the position of the boss 226 contacting the groove 242 of the cam 241 after the first restricting arm 221 is operated. Can be shortened with a simple configuration. That is, the configuration is such that the driving force of the solenoid 231 is not required to maintain the position of the boss portion 226 that is a follower that contacts the cam 241 after the first restricting arm 221 is operated. The energization time to the solenoid 231 can be shortened. In the first embodiment, a configuration for switching the boss portion position a and the boss portion position b every 45 [°] will be described, but the present invention is not limited to such a configuration, and the first ratchet It can be set as appropriate according to the size of the part and cam and the position of the first restricting arm.

A driving force for rotating the cam 241 by 45 [°] is given from a solenoid 231 that is a second driving source. Then, the boss 226 of the first restriction arm 221 fitted in the groove 242 drives the solenoid 231 that rotates the cam 241 by 45 [°], thereby driving the claw 225 and the first ratchet 212 of the first restriction arm 221. The engagement with the protrusion 213 is controlled.
Here, as described above, the cam 241 needs to stop at each rotation angle corresponding to the boss portion position a and the boss portion position b, that is, at each step. Therefore, in the first embodiment, the following configuration is provided.

  As shown in FIGS. 8 and 10 (a) and 10 (b), the reciprocating operation of the solenoid 231 provided on one end side of the second restricting arm which is the second restricting member is moved to the other end side of the second restricting arm. This is transmitted to a push claw 256 which is a provided rotary claw. And the cam 241 is rotated by pushing the claw part 244 provided in the 2nd ratchet part 243 which is a 2nd to-be-rotated regulating member with the front-end | tip of the pushing claw 256. FIG. The shape of the claw portion 244 formed in the second ratchet portion 243 is formed into a claw shape that can be rotated in one direction by abutting the tip of the push claw 256 with the rotation of the second restriction arm. Further, the pitch of the claw portions 244 of the second ratchet portion 243 and the amplitude of the second restricting arm 251 are set to be approximately equal.

  Here, as described above, the second ratchet portion 243 and the cam 241 are drivingly connected, and the pitch angle of the claw portion 244 of the second ratchet portion 243 and the boss portion position a and the boss portion position b of the cam 241 are set. Corresponding pitch angles are equal. That is, when the solenoid 231 reciprocates once, the engagement between the claw portion 244 and the push claw 256 of the second ratchet portion 243 is shifted to the next, the groove portion 242 of the cam 241 rotates, and the boss portion position a or the boss portion is rotated. The position is shifted to the position corresponding to the part position b and shifted to the next. As described above, the cam 241 has a groove 242 formed so as to correspond to the two boss position a and the boss position b, which are the movement positions of the boss 226 of the first restriction arm 221 that is the follower. There is.

  The boss portion 226 of the first restriction arm 221 that is a follower of the groove portion 242 is fitted and the groove portion 242 of the cam 241 rotates, so that the position of the boss portion 226 of the first restriction arm 221 is the boss portion position a or the boss portion. The first restricting arm 221 reciprocates by moving to the part position b. Among the reciprocating operations, when the position of the boss portion 226 is changed from the boss portion position b to the boss portion position a by one reciprocating operation of the solenoid 231, the claw portion 225 of the first restricting arm 221 is moved to the first ratchet. The sun gear 211 is fixed by meshing with the protrusion 213 of the portion 212. On the other hand, when the position of the boss part 226 transitions from the boss part position a to the boss part position b, the meshing between the claw part 225 of the first restricting arm 221 and the protrusion part 213 of the first ratchet part 212 is released, and the sun gear 211 is in a fixed release state. That is, when the groove portion 242 of the cam 241 rotates, the position of the boss portion 226 of the first restriction arm 221 transitions to the boss portion position a or the boss portion position b, so that the first restriction arm 221 reciprocates, The planetary gear clutch mechanism 200 is driven and disconnected.

Next, the configuration of the second ratchet portion 243 that is driven and connected to the cam 241 and rotates integrally, the solenoid 231 that rotates the second ratchet portion 243, the second restriction arm 251, the push pawl 256, and the like will be described in detail.
As shown in FIGS. 8 and 10A and 10B, the second restriction arm 251 as the second restriction member includes a cylindrical portion 253, an arm input portion 254, and an arm output portion 252. The cylindrical portion 253 is inserted into the support shaft 215 penetrating the second ratchet portion 243 and is rotatably supported by the support shaft 215 together with the arm input portion 254 and the arm output portion 252 that are linearly connected to the left and right. The arm input portion 254 has a connection pin 233 supported at the tip end of the plunger 232 of the solenoid 231 held by a bracket (not shown) fixed to the apparatus main body (not shown) inserted at one end side away from the cylindrical portion 253. A long hole is formed. On the other hand, an arm output unit 252 connected to the opposite side of the arm input unit 254 via the cylindrical unit 253 is provided on one end side away from the cylindrical unit 253 so as to extend downward and rotate a push claw 256. A rotating shaft 255 that is freely supported is provided.

  The solenoid 231 is supported by the bracket fixed to the apparatus main body as described above. Further, in the off state in which no power is supplied, the force of the compression coil spring disposed between the stopper member provided on the plunger 232 and the case of the solenoid 231 causes the arrow E in FIG. The plunger 232 is pushed out in the direction. Then, in the energized ON state, as shown in FIG. 10B, the plunger 232 moves in the direction of arrow F in the drawing against the force of the compression coil spring. In the solenoid 231, by providing a compression coil spring on the plunger 232, the solenoid 231 can be energized only for a predetermined time, whereby the reciprocating motion of the plunger 232 with a desired stroke and force can be obtained.

  As the solenoid 231 reciprocates, the second restricting arm 251 rotates about the support shaft 215, and the push pawl 256 rotatably held by the arm output unit 252 rotates. One end portion of a torsion coil spring 257 that is an elastic member that applies a rotational force (one direction) to the claw portion 244 side of the second ratchet portion 243 is hooked on the push claw 256. The other end is hooked on the arm output portion 252 of the second restriction arm 251. Further, a rotating shaft 255 provided in the arm output portion 252 is passed through the winding portion of the torsion coil spring 257, and is configured to prevent the torsion coil spring 257 from falling off.

The second ratchet portion 243 rotates counterclockwise in the drawing from a base point having a cross section of the reference circle (the cross section having the smallest radius), for example, a corner immediately above the center of the support shaft 215 in FIG. 10A. A range having the same radius by a predetermined angle is provided upstream of the cam 241 in the rotation direction. An inclined portion that is curved in an arc shape from the upstream end having the same radius to the outer peripheral side by about 45 [°] is formed, passes through the center of the support shaft 215 from the upstream end portion of the inclined portion, and is 45 to the vertical. A claw portion 244 having a straight line connecting points on the reference circle forming an angle of [°] is provided every 45 °.
Further, at the tip of the push claw 256, as shown in FIG. 10 (a), a surface contact portion that is substantially in surface contact with the reference circle portion of the second ratchet portion 243 is formed in a state where the solenoid 231 is turned off. On the upstream side, an arc portion is formed in point contact with the inclined portion of the claw portion 244.

When the solenoid 231 is turned on, the plunger 232 is pulled in the direction of arrow F in FIG. 10B, and the push claw 256 provided on the second restriction arm 251 rotates in the direction of arrow H. Then, the tip of the push pawl 256 pushes the straight portion of the second ratchet portion 243 to rotate the second ratchet portion 243 in the direction of arrow I by about 45 [°], and the state shown in FIG.
When this state is reached, the solenoid 231 is turned off. Then, due to the force of the compression coil spring, the plunger 232 is pushed out in the direction of the arrow E in FIG. 10A, and the pushing claw 256 provided on the second restricting arm 251 rotates in the direction of the arrow G, Start returning to the state. At this time, the push claw 256 is pressed against the inclined portion side of the claw portion 244 by the torsion coil spring 257. Here, the shape of the inclined portion of the claw portion 244 and the arc portion of the push claw 256 is formed so that the second ratchet portion 243 does not reversely rotate, and the surface contact portion provided at the tip of the push claw 256 is Overcoming the end of the inclined portion of the claw portion 244, the surface of the claw portion 244 is substantially in surface contact with the reference circular portion.

  The surface contact portion provided at the tip of the push claw 256 is pressed by the torsion coil spring 257 to the reference circular portion of the claw portion 244 on the upstream side of the second ratchet portion 243 and is in substantially surface contact. This state is maintained until the second restricting arm 251 swings again. In other words, until the solenoid 231 is turned on again and the second restricting arm 251 swings, the push claw 256 transitions and meshes with the claw portion 244 on the one upstream side of the second ratchet portion 243, so that about 45 [ The state of the second ratchet portion 243 rotated by [°] can be maintained.

  Here, as described above, the second ratchet portion 243 is drivingly connected to the cam 241 and rotates integrally with the cam 241. Therefore, for example, the first restricting arm 221 is moved from the unlocked state shown in FIGS. 9A and 10A to the fixed state shown in FIGS. 9B and 10B. ) It can be switched by rotating in the direction of arrow A in the figure. On the other hand, from the fixed state shown in FIGS. 9 (b) and 10 (b) to the unlocked state shown in FIGS. 9 (a) and 10 (a), it rotates in the direction of arrow B in FIG. 9 (a). Can be switched. That is, every time the solenoid 231 is turned on for a predetermined time, the planetary gear clutch mechanism 200 can be switched between the state where it is driven and connected and the state where it is disconnected.

  As described above, in the planetary gear clutch mechanism 200 of the first embodiment, the first restriction arm is moved from the solenoid 231 that makes the claw part 225 of the first restriction arm 221 contact or retract with respect to the protrusion 213 of the first ratchet part 212. A cam 241 is used for driving transmission to the motor 221. The cam 241 does not require a driving force from the solenoid 231 to maintain the position of the boss portion 226 provided on the first restriction arm 221 that is the follower moved by the operation of the cam 241 as described above. It is configurable. That is, by using the cam 241 in the drive train that transmits the drive to the first restriction arm 221, the position of the follower such as the boss 226 that operates the first restriction arm 221 is moved to the position after the first restriction arm 221 is operated. The driving force of the solenoid 231 is not required to maintain.

Therefore, the energization time to the solenoid 231 can be performed only during the operation of bringing the claw portion 225 of the first restricting arm 221 into contact with or retracting from the protrusion 213 of the first ratchet portion 212. That is, it can be performed only during the operation of switching the drive connection and disconnection between the developing roller 4 and the like and the drive motor that drives the developing roller 4 and the like. As described above, the energization time to the solenoid 231 is shortened only when the connection operation and the disconnection operation are performed, thereby suppressing the temperature rise of the solenoid 231 and reducing the current energizing the solenoid 231 and increasing the number of turns of the magnetic coil. The desired stroke and force can be obtained.
That is, the solenoid 231 included in the planetary gear clutch mechanism 200 can be reduced in size and energy can be saved.

Accordingly, the first restriction arm 221 that restricts the rotation of the first ratchet portion 212 is operated to reduce the size of the solenoid 231 that switches between driving connection and disconnection between the developing roller 4 and the driving motor that drives the developing roller 4 and the like. And energy saving. Thus, the planetary gear clutch mechanism 200 in which the solenoid 231 can be reduced in size and energy can be provided.
Therefore, the first driving member that restricts the rotation of the first rotation regulating member is operated to switch the driving connection between the driven body and the first driving source that drives the driven body. A speed conversion mechanism including a clutch mechanism that can be reduced in size and energy can be provided.
Also, by reducing the energization time to the solenoid 231 and reducing the size of the solenoid 231, the solenoid 231 can be reduced in weight, and the amount of copper used for the magnetic coil can be reduced, further promoting cost reduction. You can also

  A planetary gear clutch mechanism 200, which is one of the planetary clutch mechanisms using a planetary mechanism, is used as a clutch mechanism for switching between driving connection and disconnection between the developing roller 4 and the like and a drive motor that drives the developing roller 4 and the like. Yes. Here, as an advantage of the planetary clutch mechanism, there is a deceleration function. In other words, the clutch mechanism also has a speed reduction function for the planetary mechanism, so the number of reduction gears such as stepped gears from the drive source to the driven system can be reduced, reducing the number of gears and reducing the size of the drive motor. Can contribute. Moreover, by having the planetary mechanism part in the clutch mechanism, it is possible to obtain a high reduction ratio in a space-saving manner and to withstand a high load torque.

  Further, as described above, the cam 241 has two or more positions of the boss portion 226 which is a follower provided on the first restriction arm 221 to be selectively moved, such as the boss portion position a and the boss portion position b. Provided. Therefore, the operation | movement which the 1st control arm 221 controls or cancels | releases the rotation of the 1st ratchet part 212 is realizable by simple structure.

  The switching means 230, which is a drive train for transmitting drive from the solenoid 231 to the first restricting arm 221, has a second ratchet portion 243, a push claw 256, and a torsion coil spring that applies a one-way rotational force to the push claw 256. 257. Since the second ratchet portion 243 is driven and connected to the cam 241 so as to rotate integrally with the cam 241, the second ratchet portion 243 can be rotated by a predetermined angle by the push pawl 256. Thus, by rotating the second ratchet portion 243 by a predetermined angle, the boss portion 226 that is a follower provided on the first restriction arm 221 can be selectively moved. Therefore, the configuration in which the solenoid 231 is energized can be realized with a simple configuration only when the rotation restriction and release state by the first restriction arm 221 of the first ratchet portion 212 is changed. Further, since the push claw 256 is hooked on the second ratchet portion 243, the cam 241 does not rotate (operate) without permission.

Further, since the solenoid 231 is used as the second drive source for swinging (operating) the second restricting arm 251, the second drive source for operating the first restricting arm 221 can be configured at low cost.
Further, a cam 241 that is a flat groove cam is used as a cam used for a drive train that transmits a driving force from the solenoid 231 to the first restriction arm 221. Therefore, the structure which operates the 1st control arm 221 is provided in the one end part of the 1st control arm 221, and the boss | hub part 226 which is a follower which operates the 1st control arm 221 is made into the groove part of the cam 241 which is a plane groove cam. It is possible to make a simple configuration that fits to 242.

  Here, in the planetary gear clutch mechanism 200 of the first embodiment, as described above, the shape of the inclined portion of the claw portion 244 of the second ratchet portion 243 and the shape of the arc portion of the push claw 256 of the second restriction arm 251 are the first. The two ratchet portions 243 are configured not to reversely rotate. However, the present invention is not limited to such a configuration. For example, as shown in FIGS. 8 and 10 (a) and 10 (b), a reverse rotation preventing claw 246 and a torsion coil spring 247 are separately supported by a bracket 249 and the like, and the cam 241 has an outer periphery for preventing reverse rotation. The third ratchet portion 245 may be provided. With this configuration, even when the claw portion 244 of the second ratchet portion 243 and the push claw 256 of the second restricting arm 251 are worn or the processing accuracy and assembly accuracy are low, a stable cam can be obtained. 241 can be rotated.

  In Patent Document 2, a clutch mechanism using the following cam is described. An input gear that meshes with a motor gear that is drive-coupled to a motor that is a first drive source is guided by a guide shaft that is considered to also serve as a rotation shaft in a state where the meshing with the motor gear is maintained, and the length of the guide shaft Displaceable in the vertical direction. Further, the tooth width of the motor gear is configured so as to maintain the meshing even when the input side gear slides. An output side gear is provided on the same rotational axis as the input side gear, and this output side gear meshes with a driven system gear on the downstream side in the drive transmission direction.

  Further, on the side surfaces of the input side gear and the output side gear that are opposed to each other, a coupler having a cross section inclined with respect to the side surface is integrally provided, and the guide shaft is surrounded between the couplers (outside). A coil spring (spring) is provided so as to fit. And, on the side of the side opposite to the side where the coupler of the input side gear is provided, the state of fitting the coupler of the input side gear and the output side gear and the state of releasing the fitting are changed by rotating. The cam to be abutted is provided. In addition, an elongated hole is provided on the opposite side to the side where the cam abuts on the side surface of the input side gear, and a solenoid plunger (actuator) for rotating the cam is supported in the elongated hole. ing.

  When the solenoid is not energized, the plunger is extended, and the input side gear is displaced to a position away from the output side gear side by the force of the coil spring and is in contact with the cam. The coupling between the side gear and the output side gear is released. That is, the drive connection between the driven body and the drive source is cut off. On the other hand, when the solenoid is energized, the plunger is retracted to rotate the cam, and the rotating cam pushes the side surface of the input side gear against the output side of the coil spring against the force of the coil spring. Fit the coupler. When the couplers of the input side gear and the output side gear are engaged with each other in this way, the rotational driving force of the motor is driven and connected to be transmitted to the output side gear through the input side gear. Here, in this clutch mechanism, it is possible to achieve an effect that the current supplied to the solenoid to maintain the state where the input side gear and the output side gear are drivingly connected can be made smaller than when the cam is rotated. .

  However, unlike the planetary gear clutch mechanism 200 of the first embodiment in which the cam 241 is used in the drive train that rotates the first restriction arm 221 that is the first restriction member, the clutch mechanism described in Patent Document 2 rotates. The cam is brought into contact with the input side gear, which is also a rotating body that transmits the driving force. In this way, the cam is brought into contact with the side surface of the input side gear and pushed to the output side gear side so that the drive connection is made. Slides. If the cam slides on the input side gear as described above, it causes wear of the input side gear and the cam, vibration and noise, which is not preferable.

  Furthermore, although maintaining the state where the input side gear and the output side gear are connected to each other can be made smaller than when the cam is rotated, it is necessary to energize the solenoid, thereby reducing power consumption. Is smaller than the planetary gear clutch mechanism 200 of the first embodiment.

  In the first embodiment, the present invention is applied to the drive gear train 70 of the image forming unit 10 that drives the photosensitive member 1 as a latent image carrier and the developing roller 4 as a developer carrier, that is, an image forming system. Although the applied example has been described, the present invention is not limited to such a configuration. For example, a paper feed resist system for driving the registration roller pair 42 and the sheet conveying roller, a paper discharge system for driving the fixing roller pair, a decompression cam, and a paper discharge roller, and the primary transfer roller 21 and the intermediate transfer belt 24. The present invention can also be applied to a drive system such as a medium-indirect separation system that contacts and separates. However, although vibrations to the image forming unit 10 and the writing unit affect the image quality, the image forming system drive gear train 70 is particularly likely to be a problem because it is disposed close to the unit.

  Further, the description has been given of the planetary gear clutch mechanism 200 of the type in which the ratchet portion, which is the rotation restricting portion, is coaxially driven and connected to the sun gear and is provided so as to rotate integrally (drive-connected). However, the present invention is not limited to such a configuration. Any type of planetary gear clutch mechanism that enables the drive transmission function of the planetary gear mechanism by drivingly connecting the ratchet portion to any one of the sun gear, carrier, and internal gear and restricting the rotation thereof. Is also applicable. For example, the present invention can also be applied to a planetary gear clutch mechanism of a two-body type that is drivingly connected using a coupling or the like.

  Further, the configuration using the planetary gear clutch mechanism 200 having the planetary gear portion 210 as the clutch mechanism has been described, but the present invention is not limited to such a configuration. For example, a planetary roller clutch mechanism having a planetary roller mechanism may be used. However, although the planetary roller clutch mechanism has an advantage that backlash can be suppressed, the configuration of the clutch mechanism is complicated and it is necessary to increase the processing accuracy of the constituent members. For this reason, the configuration using the planetary gear clutch mechanism can be made cheaper than the configuration using the planetary roller clutch mechanism.

  Further, the example of the planetary gear clutch mechanism 200 in which the groove portion 242 of the cam 241 is formed so that the boss portion 226 of the first restricting arm 221 transitions to the two boss portion positions a and b is described. Is not limited to such a configuration. For example, when the groove portion 242 of the cam 241 is moved at a certain angle, the boss portion 226 of the first restricting arm 221 is output at three boss portion positions a, boss portion b, and boss portion position c: r [mm] (boss It can also be formed so as to switch to the part position a> the boss part position b> and the boss part position c). Then, the boss portion 226 of the first restriction arm 221 is transitioned to the boss portion position a to place the sun gear 211 in the fixed state, and the boss portion position b is transitioned to place the sun gear 211 in the unlocked state. The first restricting arm 221 is further rotated by shifting to the position c.

By using the further rotation of the first restricting arm 221, another clutch mechanism is switched, or a switching claw provided in the transport path is operated to drive other drive systems. The solenoid 231 can also be used for further energy saving. That is, by providing three or more positions of the boss portions 226 of the first restriction arm 221 that is the follower, the solenoid 231 can also serve as a drive source for switching operation of other drive systems, and further energy saving can be achieved. It becomes possible.
However, the boss portion 226 of the first restriction arm 221 is camped so as to transition in the order of, for example, the boss portion position a, the boss portion position b, the boss portion position c, the boss portion position b, the boss portion position a,. It is assumed that the groove portion 242 of 241 is formed. Then, after the sun gear 211 is released from the fixed state, the solenoid 231 needs to be turned on and off three times in order to change the sun gear 211 to the fixed state, that is, from the boss part position b to the boss part position a again. The responsiveness of the clutch operation of the planetary gear clutch mechanism 200 is deteriorated. That is, if the position of the output displacement of the boss 226 of the first restricting arm 221 that moves by being fitted to the groove 242 of the cam 241 is increased, the responsiveness of the clutch operation of the planetary gear clutch mechanism 200 is deteriorated.

The cam 241 of the planetary gear clutch mechanism 200 of the first embodiment is a flat groove cam having a groove portion 242 that is a cam groove to which the boss portion 226 of the first restriction arm 221 that is a follower is fitted and brought into contact. . Then, each time the cam 241 rotates 45 [°], a groove portion 242 having a closed curve locus in which the center line is closed and the distance between the rotation center position of the cam 241 and the boss portion 226 is provided is provided.
The first restricting arm 221 has two arm portions, namely, an arm output portion 222 and an arm input portion 224 with a cylindrical portion 223 that is a rotation fulcrum as a break point. One arm output portion 222 is provided with a claw portion 225 that engages or releases the engagement with the protrusion 213 provided on the first ratchet portion 212 according to the rotation of the cam 241. Yes. A boss portion 226 which is a follower is provided at one end portion of the other arm input portion 224.

By configuring the first restriction arm 221 that is the first restriction member and the cam 241 that operates the first restriction arm 221 as described above, the following effects can be achieved. The boss 226 for operating the first restricting arm 221 can be simply configured to fit into the groove 242 of the cam 241 that is a flat groove cam. Further, by rotating the cam 241 by 45 [°], it is possible to surely switch between driving connection and disconnection between the developing roller 4 as the driven body and the driving motor as the first driving source. Further, as described above, it is easy to provide three or more follower positions depending on the shape of the groove portion 242, and the solenoid 231 as the second drive source also serves as a drive source such as a switching operation of another drive system. It is possible to save energy.
Further, since the groove portion 242 has a locus of a closed curve in which the center line is closed, the solenoid 231 that is the second drive source is not locked even if the cam 241 is excessively rotated.

Further, the planetary gear clutch mechanism 200 of the first embodiment is configured such that the first ratchet portion 212 that is the first rotation restricting member and the rotation shaft of the cam 241 of the switching unit 230 are used as the support shaft that is the rotation shaft of the planetary gear portion 210. It also serves as 215. That is, the planetary gear clutch mechanism 200 is a main component of a planetary gear unit 210 that is a planetary gear mechanism and a fixing mechanism that fixes one of the three rotating elements of the planetary gear unit 210. One ratchet portion 212 and a cam 241 are provided on the same axis.
By providing coaxially in this way, as shown in FIG. 8, it is possible to arrange other components of the rotation restricting portion 220 and the switching means 230 in the vicinity of the axis of the support shaft 215 of the planetary gear portion 210. Become. Therefore, the area occupied by the planetary gear clutch mechanism 200 when projected onto a plane perpendicular to the axis of the support shaft 215 of the planetary gear unit 210 can be reduced, and the planetary gear clutch mechanism 200 can be arranged in a space-saving manner. Can do.

[Embodiment 2]
Hereinafter, a second embodiment (hereinafter, referred to as a second embodiment) of an image forming apparatus to which the present invention is applied will be described.
The printer 300 as the image forming apparatus according to the second embodiment is different from the printer according to the first embodiment only in the following configuration, and the other configuration is the same as that of the printer of the first embodiment. Therefore, in the second embodiment, description of the overall configuration and operation of the printer 300 is omitted.
The configuration similar to that of the first embodiment and the operation and effect thereof will be omitted as appropriate, and the components that perform the same functions as the components of the printer of the first embodiment and the same components Unless otherwise specified, the same reference numerals are used for explanation.

The difference between the printer 300 of the second embodiment described above and the printer of the first embodiment is that the configuration relates to the configuration of the slider unit 260 and the switching unit 230 that function as the rotation regulating unit 220 of the planetary gear clutch mechanism 200. . In addition, the number of the projection parts 213 provided in the 1st ratchet part 212 which is a 1st to-be-rotated regulating member is also different.
The difference between the second embodiment and the first embodiment will be described below with reference to the drawings.

  Here, FIG. 12 is an explanatory perspective view of the planetary gear clutch mechanism 200 according to the second embodiment. 12 (a) is an overall perspective explanatory view looking down from the cam drive motor 271 side that is the second drive source, and FIG. 12 (b) is the first ratchet portion 212 looking up from the output gear 216 side and switching. FIG. FIGS. 13A and 13B are explanatory diagrams of the first ratchet portion 212 and the slider portion 260 according to the second embodiment, in which FIG. 13A is an explanatory view of a drive connection state, and FIG. 13B is an enlarged view of the slider portion 260. It is explanatory drawing.

FIG. 14 is an explanatory diagram of drive coupling and blocking operations by the slider portion 260 according to the second embodiment. 14A is an explanatory diagram of a first state in which the slider protruding portion 265 of the slider 261 contacts (fits) the protruding portion 213 of the first ratchet portion 212. FIG. FIG. 14B is an explanatory diagram of a second state in which the slider protruding portion 265 of the slider 261 is separated from the protruding portion 213 of the first ratchet portion 212. FIG. 14C is an explanatory diagram of a separated state in which the slider protruding portion 265 of the slider 261 is completely separated from the protruding portion 213 of the first ratchet portion 212.
Here, with respect to the gear portions in each of the drawings excluding the protrusions of the ratchet portions, the tooth profile is omitted as in the first embodiment, and only the reference pitch circle is described.

As shown in FIG. 12A, the planetary gear clutch mechanism 200 of the second embodiment functions as a rotation restricting portion 220 that restricts rotation of the first ratchet portion 212 that is the first rotation restricting member or releases the rotation restriction. The slider portion 260 is provided. As a switching means 230 for operating the slider portion 260, a cam 241 and a cam drive motor 271 as a second drive source for rotating the cam 241 are also provided. Since it is configured in this way, the planetary gear clutch mechanism 200 of the second embodiment is particularly simple in the configuration of the switching means 230 compared to the planetary gear clutch mechanism of the first embodiment described with reference to FIG. Can be a thing.
As described above, the number of the protrusions 213 of the first ratchet part 212 is different from that of the first embodiment, but the functions of the protrusions 213 of the first ratchet part 212 and the first ratchet part 212 are the same. The description is omitted.

  The slider portion 260 includes a slider 261 that is a moving member that functions as a first restricting member that restricts rotation of the first ratchet portion 212 or releases the rotation restriction, and a slider frame portion 262 that supports the slider 261 in a movable manner. doing. Further, as shown in FIGS. 12A and 12B, the slider 261 facing the cam 241 is fitted to a groove 242 that is a cam groove formed in the cam 241 and moved (driven). A slider boss portion 266 that is a node (follower) is provided. On the other hand, on the side facing the first ratchet portion 212, the slider 261 moves to engage (contact) the projection 213 of the first ratchet portion 212, or release (retract) the engagement. A slider protrusion 265 is provided. The two coil springs 263 that urge the slidably supported slider 261 toward the approximate center of the moving range of the slider frame 262 are opposed to the approximate center of the short surface of the slider 261 in the moving direction. The unit 262 is connected to each other.

The cam 241 is provided with a groove 242 on the side facing the slider portion 260 (first ratchet portion 212). By rotating, the slider 261 is provided with a slider boss portion 266 fitted in the groove 242. Is moved within the slider frame portion 262.
Here, the groove portion 242 of the cam 241 according to the second embodiment has a center line whose radial line has a circular locus coaxial with the rotation axis of the cam 241, an inner circular groove portion 242 a on the inner side, and an outer circular groove portion 242 b on the outer side. Have two circular grooves. Further, the connecting groove 242c for guiding the slider boss 266 provided on the slider 261 to one of the two circular grooves of the inner circular groove 242a and the outer circular groove 242b according to the rotation direction of the cam 241 is rotated by the cam 241. There are two axisymmetric axes.
On the other hand, on the opposite side of the cam 241, there are external teeth that mesh with external teeth formed near the end of the motor output shaft 272 of the cam drive motor 271 and transmit the rotational drive force of the cam drive motor 271 to the cam 241. The formed external tooth boss 248 is provided coaxially with the rotation shaft of the cam 241.
The cam 241 is provided with a hole through which the support shaft 215 of the planetary gear unit 210 is fitted and fitted. The support shaft 215 fitted into the hole serves as a rotation shaft of the cam 241.

The cam drive motor 271 is arranged such that the motor output shaft 272 is parallel to the rotation shaft of the cam 241 and the external teeth formed on the motor output shaft 272 are engaged with the external tooth boss portion 248 provided on the cam 241. ing.
Then, by rotating the motor output shaft 272 of the cam drive motor 271 in any direction, the cam 241 rotates in the direction opposite to the rotation direction of the motor output shaft 272.

  Further, as shown in FIG. 13A, the slider 260 has a support shaft whose moving direction of the slider 261 as the first restricting member is the rotation axis of the first ratchet 212 as the first rotation restricting member. It is provided in a direction perpendicular to the axis 215. Further, when the slider boss portion 266 provided on the slider 261 is fitted in the inner circular groove portion 242 a provided on the cam 241, the slider protruding portion 265 provided on the slider 261 is formed on the first ratchet portion 212. The protrusions 213 are engaged with each other.

Thus, the state of the slider part 260 when the slider protrusion part 265 of the slider 261 meshes with the protrusion part 213 of the first ratchet part 212 is as shown in FIG. That is, the slider 261 moves to a side closer to the rotation axis of the first ratchet portion 212 in the slider frame portion 262 (hereinafter referred to as the inner side), and the inner coil spring 263 contracts, and is separated from the rotation axis of the first ratchet portion 212. The coil spring 263 on the other side (hereinafter referred to as the outside) extends. As the two coil springs 263 are deformed in this way, an urging force that moves the slider 261 toward the approximate center of the moving range of the slider frame portion 262 acts.
Then, the cam 241 and the slider are arranged so that the position of the slider boss 266 of the slider 261 moved to approximately the center of the moving range in the slider frame 262 is approximately the center in the radial direction of the inner circular groove 242a and the outer circular groove 242b. Part 260. For this reason, the slider boss 266 is biased so that the position of the slider boss 266 is approximately the center in the radial direction of the inner circular groove 242a and the outer circular groove 242b.

  Next, referring to FIG. 14, the first ratchet portion with reference to the second state in which the connection groove portion 242c and the slider boss portion 266 are fitted at the approximate center in the radial direction of the inner circular groove portion 242a and the outer circular groove portion 242b. The operation of the rotation restriction 212 or the rotation restriction release will be described.

  In the second state shown in FIG. 14B, the slider boss portion 266 is fitted to the connection groove portion 242c at the approximate center in the radial direction of the inner circular groove portion 242a and the outer circular groove portion 242b of the connection groove portion 242c. In this second state, the slider protruding portion 265 provided on the slider 261 and the projection 213 of the first ratchet portion 212 (not shown) are not in contact, that is, in a non-contact state. For this reason, in the second state, the first ratchet portion 212 is in a state where the rotation restriction is released, the sun gear 211 rotates, the carrier 204 does not rotate, and the drive connection by the planetary gear clutch mechanism 200 is not performed. It becomes a cut-off state. Hereinafter, the position of the slider 261 shown in FIG. 14B is referred to as a neutral position.

  When the cam 241 is rotated clockwise (CW) from the second state, the slider boss portion 266 is guided along the connecting groove portion 242c that draws a locus so as to approach the inside of the cam 241 from the outer circular groove portion 242b, and outward. It moves to the inner circular groove 242a against the urging force. As the slider boss portion 266 moves, the slider 261 provided with the slider boss portion 266 moves inward to enter the first state shown in FIG. In this first state, the slider protruding portion 265 provided on the slider 261 and the projection 213 of the first ratchet portion 212 (not shown) are in contact with each other. Therefore, in the first state, the first ratchet portion 212 is in a state where the rotation is restricted, the rotation of the sun gear 211 is fixed, the carrier 204 is rotated, and the drive connection by the planetary gear clutch mechanism 200 is performed. It becomes a state. Hereinafter, the position of the slider 261 shown in FIG.

  When the cam 241 is rotated counterclockwise (CCW) from the second state, the slider boss portion 266 is guided along the connection groove portion 242c that draws a trajectory that leaves the inner circular groove portion 242a to the outside of the cam 241. It moves to the outer circular groove 242b against the biasing force. Along with the movement of the slider boss 266, the slider 261 provided with the slider boss 266 moves to the outside and enters the third state shown in FIG. In this third state, the slider protruding portion 265 provided on the slider 261 and the projection 213 of the first ratchet portion 212 (not shown) are further separated from each other and are not in contact with each other, that is, in a non-contact state. Therefore, in the third state, the first ratchet portion 212 is in a state in which the rotation restriction is released, the sun gear 211 rotates, the carrier 204 does not rotate, and the drive connection by the planetary gear clutch mechanism 200 is not performed. It becomes a cut-off state. Hereinafter, the position of the slider 261 shown in FIG.

When the cam 241 is rotated counterclockwise (CCW) from the first state, the slider boss portion 266 is guided along the connection groove portion 242c that draws a locus that approaches the outside of the cam 241 from the inner circular groove portion 242a. The outer circular groove 242b is moved to the third state. Here, when the counterclockwise rotation of the cam 241 is stopped so that the slider boss portion 266 is substantially in the radial center of the inner circular groove portion 242a and the outer circular groove portion 242b of the connection groove portion 242c, the second state is obtained.
In addition, when the cam 241 is rotated clockwise (CW) from the third state, the slider boss 266 is guided along the connection groove 242c that draws a locus that approaches the inside of the cam 241 from the outer circular groove 242b. It moves to the inner circular groove 242a and enters the first state. Here, when the rotation of the cam 241 in the clockwise direction is stopped so that the slider boss 266 is substantially in the radial center of the inner circular groove 242a and the outer circular groove 242b of the connection groove 242c, the second state is obtained.

In the planetary gear clutch mechanism 200 according to the second embodiment, as described above, the rotation restriction or the rotation restriction release operation of the first ratchet portion 212 according to the rotation direction of the cam 241, that is, the drive connection of the planetary gear clutch mechanism 200. Switching to the shut-off state can be performed.
Then, after the cam 241 is rotated clockwise (CW) from the second state or the third state and changed to the first state, that is, after the rotation of the sun gear 211 is fixed, until the fixing is released. Since the slider 261 need not be moved, the cam 241 need not be rotated. In addition, after the cam 241 is rotated counterclockwise (CCW) from the first state and changed to the second state or the third state, that is, after the rotation of the sun gear 211 is released and fixed. Since the slider 261 need not be moved, the cam 241 need not be rotated.

As described above, in the planetary gear clutch mechanism 200 of the second embodiment, the rotation restriction or rotation restriction release operation of the first ratchet portion 212, that is, the switching operation between the driving connection and the cutoff state of the planetary gear clutch mechanism 200 is performed. It is only necessary to rotate the cam 241 at this time.
Therefore, the cam drive that is the second drive source is used to maintain the position of the slider boss portion 266 that is the follower that contacts the cam 241 that operates the slider 261 that is the first restricting member after the slider 261 is operated. The driving force of the motor 271 can be eliminated. That is, the cam drive motor 271 can be driven only during an operation of switching between driving connection and disconnection between the developing roller 4 and the driving motor that drives the developing roller 4 and the like.
Thus, energy saving of the cam drive motor 271 included in the planetary gear clutch mechanism 200 can be achieved only during the operation of switching the drive of the cam drive motor 271.

Next, the movement of the slider 261 when switching the driving connection and disconnection state of the planetary gear clutch mechanism 200 will be described in more detail with reference to Tables 1 and 2.

As shown in Table 1, when the slider 261 is in the first position, the repulsive force is received from the coil spring 263 connected to the inside between the slider frame portion 262 and the slider 261 and connected to the outside. The coil spring 263 receives a tensile force. As a result, the slider 261 receives an outward urging force as a resultant force of the two coil springs 263.
In other words, when the slider boss portion 266 of the slider 261 is in the first state where the slider boss portion 266 is fitted into the inner circular groove portion 242a, the slider 261 receives an outward biasing force as a resultant force of the two coil springs 263 provided on the slider portion 260.

In this state, when the cam 241 is rotated counterclockwise (CCW), the slider boss portion 266 draws a trajectory such that the slider boss portion 266 moves away from the inner circular groove portion 242a to the outside of the cam 241. It moves along the groove side wall and moves to the second state. After that, through the second state, while receiving the urging force inward as the resultant force of the two coil springs 263, against the urging force, along the groove sidewall on the upstream side in the rotational direction of the cam 241 of the connecting groove 242c. The slider 261 moves so as to be pushed outward and moves to a third state where the slider 261 is at the outer position.
That is, when the cam 241 is rotated counterclockwise (CCW) when the slider boss portion 266 of the slider 261 is in the first state where the slider boss portion 266 is fitted in the inner circular groove portion 242a, the slider boss portion 266 passes through the connection groove portion 242c. It moves to the groove 242b.

By moving the slider boss portion 266 in this way, the position of the slider 261 provided with the slider boss portion 266 moves from the inner position to the outer position through the neutral position. When the slider 261 moves in this way, the contact of the slider protruding portion 265 provided on the slider 261 with the first ratchet portion 212 is released and a non-contact state is established.
Then, the rotation of the sun gear 211 that rotates integrally with the first ratchet portion 212 is released, the sun gear 211 rotates, the carrier 204 does not rotate, and the drive connection by the planetary gear clutch mechanism 200 is not performed. It becomes a cut-off state.

On the other hand, when the slider 261 is in the third state at the outer position, it receives a repulsive force between the slider frame portion 262 and the slider 261 from the coil spring 263 connected to the outside, and from the coil spring 263 connected to the inside. Receives tensile force. As a result, the slider 261 receives an inward biasing force as a resultant force of the two coil springs 263.
That is, when the slider boss portion 266 of the slider 261 is in the third state in which the slider boss portion 266 is fitted into the outer circular groove portion 242b, the slider 261 receives an inward biasing force as a resultant force of the two coil springs 263 provided on the slider portion 260.

In this state, when the cam 241 is rotated in the clockwise direction (CW), the slider boss 266 draws a trajectory such that the slider boss 266 approaches the inside of the cam 241 from the outer circular groove 242b on the upstream side in the rotation direction of the cam 241. It moves along the groove side wall and moves to the second state. After that, through the second state, while receiving an outward biasing force as a resultant force of the two coil springs 263, against the biasing force, along the groove sidewall on the downstream side in the rotational direction of the cam 241 of the connecting groove 242c. The slider 261 moves so as to be pushed inward, and moves to the first state where the slider 261 is in the inner position.
In other words, when the slider boss portion 266 of the slider 261 is in the third state in which the slider boss portion 266 is fitted to the outer circular groove portion 242b, when the cam 241 is rotated clockwise (CW), the slider boss portion 266 passes through the connection groove portion 242c. Move to 242a.

By moving the slider boss portion 266 in this way, the position of the slider 261 provided with the slider boss portion 266 moves from the outer position to the inner position through the neutral position. When the slider 261 moves in this manner, a contact state is brought into contact with the first ratchet portion 212 of the slider protrusion 265 provided on the slider 261.
Then, the rotation of the sun gear 211 that rotates integrally with the first ratchet portion 212 is fixed, and the carrier 204 is rotated to be in a drive connection state in which the drive connection by the planetary gear clutch mechanism 200 is performed.

As shown in Table 2 below, even when the cam 241 is rotated clockwise (CW) in the first state, it remains in the first state. Moreover, even if the cam 241 is rotated counterclockwise (CCW) in the third state, it remains in the third state.

The reason why the first state can be maintained even when the cam 241 is rotated clockwise (CW) in the first state as described above is as follows.
In the first state, the slider 261 receives an outward biasing force as a resultant force of the two coil springs 263 provided on the slider portion 260, while the cam 241 rotates clockwise, the outer side of the inner circular groove portion 242a. It slides on the groove side wall. As described above, when sliding on the outer groove side wall of the inner circular groove portion 242a, when the cam 241 rotates clockwise, the slider boss portion 266 is again reached when the connection position with the connection groove portion 242c is reached. Tries to move outward (on the side of the connecting groove 242c). However, since the connecting groove 242c is formed so as to draw a locus in which the center line approaches the rotation axis of the cam 241 as the cam 241 rotates clockwise, it is pushed back to the inner circular groove 242a side again. .

On the other hand, the third state can be maintained even when the cam 241 is rotated counterclockwise (CCW) in the third state for the following reason.
In the third state, the slider 261 receives the urging force inward as the resultant force of the two coil springs 263 provided in the slider portion 260, and the inner side of the outer circular groove portion 242b as the cam 241 rotates counterclockwise. It slides on the groove side wall. As described above, when sliding on the inner groove side wall of the outer circular groove portion 242b, when the cam 241 rotates counterclockwise, the slider boss portion is again reached when the connection position with the connection groove portion 242c is reached. 266 tends to move inward (on the side of the connecting groove 242c). However, since the connecting groove portion 242c is formed so as to draw a locus in which the center line of the cam 241 rotates counterclockwise and away from the rotation axis of the cam 241, it is pushed back to the outer circular groove portion 242b side again. Become.

  Further, the cam 241 of the planetary gear clutch mechanism 200 of the second embodiment includes an inner circular groove portion 242a, an outer circular groove portion 242b, and a connecting groove portion 242c, which are cam grooves to which a slider boss portion 266 that is a follower is fitted and brought into contact. This is a flat groove cam having a groove portion 242. In addition, a slider 261 that is a first restricting member that is movable in a direction perpendicular to the axis of the support shaft 215 that functions as the rotation shaft of the first ratchet portion 212 that is the first rotation restricting member is provided. The slider 261 includes a slider protruding portion 265 that engages with and releases the protrusion 213 of the first ratchet portion 212 and the slider boss portion 266 that fits in each groove portion of the cam 241. Yes. Then, the two coil springs 263 are arranged so that the position of the slider boss portion 266 (the position of the slider 261) is a neutral position that is substantially the center in the radial direction of the two circular groove portions of the inner circular groove portion 242a and the outer circular groove portion 242b. It is energized by.

By configuring the slider 261 as the first restricting member and the cam 241 for operating the slider 261 as described above, the following effects can be obtained.
The boss portion 226 for operating the first restricting arm 221 can be simply configured to be fitted to each groove portion of the flat groove cam, and the drive connection and disconnection between the driven body and the first drive source are performed according to the rotation direction of the cam 241. Can be switched.
Further, since the two circular groove portions of the inner circular groove portion 242a and the outer circular groove portion 242b have a locus of a closed curve, the cam drive motor 271 as the second drive source is locked even if the cam 241 is excessively rotated. There is nothing.
In addition, the position where the rotation of the cam 241 is stopped when switching the driving connection and disconnection between the driven body and the first driving source is a position avoiding the connection groove 242c, so that the driven body and the first driving source are stopped. The drive connection and disconnection with one drive source can be switched reliably. For this reason, by reducing the number of connection grooves 242c (for example, two locations) and increasing the degree of freedom of the stop position of the cam 241, a DC brush motor or the like that is less expensive than a stepping motor or the like is used as the second drive source. You can also

Further, the planetary gear clutch mechanism 200 according to the second embodiment is configured such that the first ratchet portion 212 that is the first rotation restricting member and the rotation shaft of the cam 241 of the switching unit 230 are the support shaft that is the rotation shaft of the planetary gear portion 210. It also serves as 215. That is, the planetary gear clutch mechanism 200 is a main component of a planetary gear unit 210 that is a planetary gear mechanism and a fixing mechanism that fixes one of the three rotating elements of the planetary gear unit 210. One ratchet portion 212 and a cam 241 are provided on the same axis.
As shown in FIG. 12A, the slider part 260 that functions as the rotation restricting part 220 and the other constituent members of the switching unit 230 are also provided on the same axis as the axis of the support shaft 215 of the planetary gear part 210. It becomes possible to arrange | position in the vicinity. Therefore, the area occupied by the planetary gear clutch mechanism 200 when projected onto a plane perpendicular to the axis of the support shaft 215 of the planetary gear unit 210 can be reduced, and the planetary gear clutch mechanism 200 can be arranged in a space-saving manner. Can do.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A first rotation restricting member such as a first ratchet portion 212 that is drivingly connected to a first drive source such as a drive motor that drives a driven member such as the photosensitive member 1 and the developing roller 4; and the first rotation restricting member. A first restricting member such as a first restricting arm 221 that can contact or retreat with respect to the first rotation restricting member and release the rotation restriction, and a solenoid 231 that operates the first restricting member. In a speed conversion mechanism such as a planetary gear clutch mechanism 200 having a clutch mechanism having a second drive source, a cam such as a cam 241 is attached to a drive train that transmits drive from the second drive source to the first restricting member. It is characterized by being used.
According to this, as described in the first embodiment (or the second embodiment), the following effects can be achieved. By using the cam in the drive train that transmits the drive to the first restricting member, the position of the follower such as a protrusion that contacts the cam that operates the first restricting member is maintained after the first restricting member is operated. However, the driving force of the second driving source can be eliminated.

Since it can be configured as described above, the energization time to the second drive source is driven only during the operation of bringing the first restriction member into contact with or retracting from the first rotation restriction member, that is, the driven body and the driven body are driven. This is possible only during the operation of switching between driving connection and disconnection with the first driving source. In this way, the energization time to the second drive source is shortened only when the connection operation and the disconnection operation are performed, thereby suppressing the temperature increase of the second drive source and reducing the current to be supplied to the second drive source. A desired stroke and force can be obtained without increasing the number of turns of the magnetic coil. Therefore, the second drive source included in the clutch mechanism can be reduced in size and energy can be saved.
Therefore, the first driving member that restricts the rotation of the first rotation regulating member is operated to switch the driving connection between the driven body and the first driving source that drives the driven body. A speed conversion mechanism including a clutch mechanism that can be reduced in size and energy can be provided.

(Aspect B)
In (Aspect A), the cam such as the cam 241 has a position of a follower such as a protrusion such as a boss 226 provided on a first restricting member such as the first restricting arm 221 in contact with the cam. It is characterized in that the driving force of the second driving source such as the solenoid 231 is not required to maintain the regulating member after it is operated.
According to this, as described in the first embodiment (or the second embodiment), the following effects can be achieved. With a simple configuration in which the driving force of the second drive source is not required to maintain the position of the follower in contact with the cam after the first restricting member is operated, The energization time can be shortened.

(Aspect C)
In (Aspect A) or (Aspect B), the clutch mechanism is a planetary clutch mechanism such as a planetary gear clutch mechanism 200.
According to this, as described in the first embodiment (or the second embodiment), the planetary clutch mechanism is used as the clutch mechanism included in the speed conversion mechanism, which contributes to reduction of the gear portion and downsizing of the drive motor. it can. Further, a high reduction ratio can be obtained in a space-saving manner and can withstand a high load torque.

(Aspect D)
In (Aspect C), the planetary clutch mechanism includes a sun gear such as a sun gear 211, a planetary gear such as a planetary gear 205, a planet carrier such as a carrier 204 that rotatably holds the planetary gear, and an internal gear 201. A planetary gear clutch mechanism such as a planetary gear clutch mechanism 200 including a planetary gear mechanism such as a planetary gear portion 210 having an internal gear, and the first rotation restricting member such as a first ratchet portion 212 includes the sun gear One of the gear, the planet carrier, and the internal gear is drivingly connected, and the cam such as the cam 241 is driven by the second drive source such as the solenoid 231 and the first rotation restricting member. The sun gear, the planet carrier, and the sun gear driven to and connected to the first rotation regulating member Is characterized in that performed is one of the rotation restriction or rotation regulation release of the gears.
According to this, as described in the first embodiment (or the second embodiment), the effect of (Aspect C) can be realized with an inexpensive configuration as compared with a configuration using a planetary roller clutch mechanism or the like as a clutch mechanism.

(Aspect E)
In any one of (Aspect A) to (Aspect D), the cam is a flat groove cam such as a cam 241 in which a groove portion 242 is formed.
According to this, as described in the first embodiment (or the second embodiment), a structure for operating the first restricting member is provided at one end of the first restricting member, and a follower for operating the first restricting member is provided. And it can be set as the simple structure fitted to the groove part of a plane groove cam.

(Aspect F)
In any one of (Aspect A) to (Aspect E), the cam such as the cam 241 is a follower such as a boss 226 provided on the first restriction member such as the first restriction arm 221 that is selectively moved. There are two or more positions.
According to this, as described in the first embodiment (or the second embodiment), the first restricting member realizes the operation of restricting or releasing the rotation of the first rotation restricting member with a simple configuration. be able to. Further, by providing three or more follower positions, the second drive source such as the solenoid 231 can also be used as a drive source for switching operation of another drive system, and further energy saving can be achieved.

(Aspect G)
In any one of (Aspect A) to (Aspect F), a drive train such as a switching unit 230 that transmits drive from the second drive source such as the solenoid 231 to the first restriction member such as the first restriction arm 221 2 a second rotation restricting member such as a ratchet portion 243, a rotating claw such as a push claw 256 that rotates the second rotation restricting member, and a torsion coil spring 257 that applies a rotational force in one direction to the rotating claw And an elastic member.
According to this, as described in the first embodiment, the configuration in which the second drive source is energized only when the rotation restriction state and the release state by the first restriction member of the first rotation restriction member are changed is simplified. It can be realized by configuration. Further, since the rotating claw is hooked on the second rotation restricting member, the cam does not rotate (operate) without permission.

(Aspect H)
In any one of (Aspect A) to (Aspect G), the second drive source is a solenoid such as a solenoid 231.
Accordingly, as described in the first embodiment, the second drive source that operates the first restricting member can be configured at low cost.

(Aspect I)
In any one of (Aspect A) to (Aspect H), the cam such as the cam 241 is a flat groove cam having a cam groove with which a follower such as the boss portion 226 is fitted and contacted, and 45 [°]. The cam groove such as the groove portion 242 having a closed curve locus whose center line is closed, and the distance between the axis of the rotation shaft such as the support shaft 215 of the cam and the follower is switched each time the cam is rotated by a predetermined angle. The first restricting member such as the first restricting arm 221 has two arm portions having a turning fulcrum such as the cylindrical portion 223 as a break point, and one arm output portion such as the arm output portion 222 A claw portion that engages with a projection portion such as the projection portion 213 provided on the first rotation restricting member such as the first ratchet portion 212 or that is disengaged according to the rotation of the cam. Nail parts such as 225 Provided, at one end of the other arm an input section such as the arm input unit 224 is characterized in that said follower is provided, such as the boss portion 226.

According to this, as described in the first embodiment, the following effects can be obtained. The follower that operates the first restricting member can be simply configured to fit into the groove portion of the flat groove cam. Further, by rotating the cam by a predetermined angle, it is possible to surely switch between driving connection and disconnection between the driven body such as the developing roller 4 and the first driving source such as the driving motor. In addition, it is easy to provide three or more follower positions depending on the shape of the cam groove, and the second drive source such as the solenoid 231 can also serve as a drive source for switching operation of other drive systems. Energy saving can be achieved.
Further, since the cam groove has a closed curved locus whose center line is closed, the second drive source is not locked even if the cam is rotated excessively.

(Aspect J)
In any one of (Aspect A) to (Aspect H), the cam such as the cam 241 is a flat groove cam having a cam groove to which a follower such as a slider boss portion 266 is fitted and contacted, and the groove portion 242 and the like. The cam groove has a circular groove portion such as an inner circular groove portion 242a on the radially inner side and a circular groove portion such as an outer outer circular groove portion 242b on the outer side having a circular locus whose center line is coaxial with the rotation axis of the cam. The first restricting member such as the slider 261 has a circular groove and a connection groove such as a connection groove 242c that guides the follower to one of the two circular grooves according to the rotation direction of the cam. The first ratchet portion 212 or the like is provided so as to be movable in a direction perpendicular to the axis of the rotation shaft such as the support shaft 215 of the first rotation restricting member, and the first rotation according to the rotation of the cam. Regulation A projecting portion such as a slider projecting portion 265 that meshes with or releases the projecting portion such as the projecting portion 213 provided on the material, and the follower, and the position of the follower is the two The circular groove is biased so as to be substantially in the center of the radial neutral position or the like.

According to this, as described in the second embodiment, the following effects can be obtained. The follower for operating the first restricting member can be simply configured to fit into the groove portion of the flat groove cam, and the driving connection and blocking between the driven body and the first driving source can be switched depending on the rotation direction of the cam. . In addition, since the two circular grooves both have a locus of a closed curve, the second drive source such as the cam drive motor 271 is not locked even if the cam is rotated excessively.
In addition, the position where the rotation of the cam is stopped when switching the driving connection and disconnection between the driven body and the first drive source is set to a position avoiding the connection groove, so that the driven body and the first drive The drive connection and disconnection with the source can be switched reliably. For this reason, by reducing the number of connection grooves (for example, two places) and increasing the degree of freedom of the cam stop position, a DC brush motor or the like that is less expensive than a stepping motor or the like can be used as the second drive source. .

(Aspect K)
An image forming apparatus such as a printer 300 that includes a single or a plurality of drive trains that drive a plurality of driven bodies such as the photoreceptor 1 and the developing roller 4 with a single drive source, and that forms an image on a recording medium such as a sheet P. And a speed conversion mechanism such as the planetary gear clutch mechanism 200 of any one of (Aspect A) to (Aspect J) is provided in at least one of the drive train or the plurality of drive trains. It is.
According to this, as described in the first embodiment (or the second embodiment), the same effect as the speed conversion mechanism provided with the planetary gear clutch mechanism of any one of (Aspect A) to (Aspect J) can be obtained. It is possible to provide an image forming apparatus that can

(Aspect L)
In (Aspect K), a plurality of driven members driven by a drive train including the speed conversion mechanism such as the planetary gear clutch mechanism 200 include a latent image carrier such as the photosensitive member 1 and a developer such as the developing roller 4. And a carrier.
According to this, as described in the first embodiment (or the second embodiment), for example, the following effects can be obtained. A planetary gear clutch mechanism corresponding to bidirectional rotation driving is provided in the driving gear train that branches the driving gear train of the latent image carrier and the developer carrier and transmits the rotational driving force to the developer carrier. With this configuration, in addition to the effect of (Aspect K), the rotation of the developer carrying member can be kept to a minimum, and the operation for removing the deposit on the edge of the cleaning blade can be performed. The drive control of the image unit is also possible.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Developing device 4 Developing roller 5,6 Developer stirring conveyance screw 7 Photoconductor cleaning device 10 Image forming unit 11 Fixing device 21 Primary transfer roller 25 Secondary transfer roller 26 Intermediate transfer belt cleaning device 22 Drive Roller 23 Followed roller 24 Intermediate transfer belt 30 Optical writing device 40 Paper feeding device 41 Transport path 42 Registration roller pair 43 Paper discharge port 44 Paper discharge tray 70 Drive gear train 71 Drive gear 80 Photoconductor drive gear train 81 First photoconductor gear 82 Photosensitive member driving gear 90 Developing roller driving gear train 91 First developing roller gear 92 Second developing roller gear 93 Third developing roller gear 94 Developing roller driving gear 100, 200 Planetary gear clutch mechanism 101, 201 Internal gear 102 Internal tooth Gear part 103 External gear part 104,204 Carry 105, 205 Planetary gear 106, 206 Reference side plate 107 End side plate 108 Pin 109, 209 Output shaft 110, 210 Planetary gear portion 111, 211 Sun gear 112 Ratchet portion 113, 213 Projection portion 116, 216 Output gear 120, 220 Rotation Restriction part 121 Restriction arm 122, 222, 252 Arm output part 123, 215 Support shaft 124, 224, 254 Arm input part 125, 225, 244 Claw part 130, 230 Switching means 131, 231 Solenoid 132 Solenoid case 133, 232 Plunger 134 Engagement pin 135 End ring 212 First ratchet portion 221 First restriction arm 223, 253 Cylindrical portion 226 Boss portion 233 Connection pin 241 Cam 242 Groove portion 242a Inner circular groove portion 242b Outer circular groove portion 242c Connection groove portion 243 2 ratchet portion 245 3rd ratchet portion 246 Reverse rotation prevention claws 247 and 257 Torsion coil spring 248 External tooth boss portion 249 Bracket 251 Second restriction arm 255 Rotating shaft 256 Push claw 260 Slider portion 261 Slider 262 Slider frame portion 263 Coil spring 265 Slider protrusion 266 Slider boss 271 Cam drive motor 272 Motor output shaft 300 Printer P Sheet

JP 2009-073648 A Japanese Patent No. 3434457

Claims (10)

In a speed conversion mechanism having a clutch mechanism for transmitting or interrupting the driving force of the first driving source to the driven body,
The clutch mechanism includes a sun gear, a planetary gear, a planetary carrier that rotatably holds the planetary gear, and a planetary gear mechanism that includes an internal gear, and the sun gear, the planetary carrier, and the internal gear. A first rotation restricting member that is drivingly connected to any one of the first rotation restricting member, and a first rotation restricting member that is in contact with or withdraws from the first rotation restricting member and capable of releasing the rotation restriction or the rotation restriction of the first rotation restricting member; A regulating member, and a second drive source for operating the first regulating member,
The clutch mechanism restricts the rotation of the first rotation restricting member by the contact of the first restricting member with respect to the first rotation restricting member, and the driving force of the first drive source via other than the one Is transmitted to the driven body, or the rotation restriction of the first rotation restricting member is released by retracting the first restricting member with respect to the first rotation restricting member, and the one is put in an idling state. Interrupting transmission of the driving force of the first driving source to the driven body;
A speed conversion mechanism characterized in that a cam is used in a drive train for transmitting drive from the second drive source to the first restricting member. The speed conversion mechanism according to claim 1,
The speed conversion characterized in that the cam does not require the driving force of the second drive source to maintain the position of a follower such as a protrusion contacting the cam after the first regulating member is operated. mechanism. In the speed conversion mechanism according to claim 1 or 2,
A speed conversion mechanism, wherein the cam is a flat groove cam. In the speed conversion mechanism according to any one of claims 1 to 3,
The speed conversion mechanism according to claim 1, wherein the cam has two or more follower positions provided on the first restricting member to be selectively moved. In the speed conversion mechanism according to any one of claims 1 to 4,
A drive train that transmits drive from the second drive source to the first restricting member, a second rotation restricting member, a rotating claw that rotates the second rotated restricting member, and a rotational force in one direction on the rotating claw; A speed conversion mechanism comprising: an elastic member that gives In the speed conversion mechanism according to any one of claims 1 to 5,
A speed conversion mechanism characterized in that the second drive source is a solenoid. The speed conversion mechanism according to any one of claims 1 to 6,
The cam is a flat groove cam having a cam groove with which a follower is fitted and brought into contact, and each time the cam rotates by a predetermined angle, the distance between the axis of the rotation shaft of the cam and the follower is switched. A cam groove having a locus of a closed curve with a closed center line is provided;
The first restricting member has two arm portions with a turning fulcrum as a break point, and one arm output portion has a cam provided on a protrusion provided on the first rotation restricting member at one end portion. A speed conversion mechanism characterized in that a claw portion that engages or releases the engagement according to rotation of the arm is provided, and the follower is provided at one end of the other arm input portion. In the speed conversion mechanism according to any one of claims 1 to 4 ,
The cam is a flat groove cam having a cam groove with which a follower is fitted and contacted,
The cam groove has two circular grooves, a circular groove on the inner side in the radial direction of the cam and a circular groove on the outer side, the center line of which has a circular locus coaxial with the rotation axis of the cam, and the rotational direction of the cam. And a connecting groove for guiding the follower to one of the two circular grooves,
The first restricting member is provided to be movable in a direction perpendicular to the axis of the rotation shaft of the first rotation restricting member, and is provided on the first rotation restricting member according to the rotation of the cam. A projecting portion that engages with or disengages from the protruding portion and the follower, and is biased so that the position of the follower is approximately the center in the radial direction of the two circular groove portions. A speed conversion mechanism characterized by In an image forming apparatus that includes one or a plurality of drive trains that drive a plurality of driven bodies with a single drive source, and that forms an image on a recording medium,
An image forming apparatus comprising the speed conversion mechanism according to any one of claims 1 to 8 in at least one of the one or a plurality of drive trains. The image forming apparatus according to claim 9.
An image forming apparatus, comprising: a plurality of driven members driven by a driving train including the speed conversion mechanism, a latent image carrier and a developer carrier.

Images