JP6849423B2 - Sheet transfer device and image forming device - Google Patents

Description

The present invention relates to a sheet conveying equipment for use in an image forming apparatus and an image forming apparatus such as forming an image on a sheet.

Some image forming devices such as printers and copiers are provided with a drive control mechanism that controls a movable member inside the device by controlling the phase of a rotating body. For example, a mechanism for changing the position of a movable member moving along a cam surface by locking a rotating body having a cam surface to any of a plurality of locking positions is widely known.

Patent Document 1 includes a cam mechanism capable of raising and lowering a bottom plate on which paper is loaded, a disc integrally formed with the cam, an arm capable of locking the disc, and a solenoid for driving the arm. Is disclosed. The disc is formed with a first and second claw portion and a third claw portion whose radial position is different from that of the first and second claw portions. Then, the cam mechanism moves the bottom plate to the ascending position or the descending position by engaging the arm with either the first or second claw portion, and engages the arm with the third claw portion. It is possible to execute the operation of returning the disk position to the initial position with.

Japanese Unexamined Patent Publication No. 2011-126676

By the way, unlike the configuration described in the above document, in addition to the rotating body (first rotating body) such as a cam, a second rotating body having a locking portion is arranged and the second rotating body is engaged. A drive control mechanism capable of positioning the first rotating body by locking with a stopping means can be considered. In this case, when the second rotating body is locked, the driving transmission from the drive source to the second rotating body is released, so that, for example, the locking means is released from the locking portion. It is conceivable to reduce the drive load at the time of driving. However, assuming such a configuration, the second rotating body stops at a position different from the original locking position due to the rotational resistance received from the locking means, and the operation stability of the drive control mechanism becomes poor. There was a risk of deterioration.

Therefore, an object of the present invention is to provide a sheet transfer device and an image forming device capable of improving the stability of operation.

The sheet transport device according to one aspect of the present invention has a sheet transport means for transporting a sheet, a first posture for guiding the sheet transported by the sheet transport means to a first transport path, and a second transport for the sheet. A seat transfer device including a second posture for guiding to a route, a guide member changed to, and a drive control mechanism for changing the posture of the guide member, wherein the drive control mechanism is drive control. The mechanism includes a driving means, a first rotating body that rotates by a driving force from the driving means , a peripheral surface that surrounds the axis of the first rotating body, and a locking portion provided on the peripheral surface. , The second rotating body that is rotated by the driving force from the driving means, the first position that can be engaged with the locking portion, and the second position that is disengaged from the locking portion can be moved. A locking means capable of positioning the first rotating body by locking the second rotating body, and a transmission state in which the driving force from the driving means is transmitted to the first rotating body and the second rotating body. , A release state in which the transmission state is released, and a drive transmission means that switches from the transmission state to the release state when the second rotating body is locked by the locking means. And, in a state where the locking means can be moved from the second position to the first position and the locking means is held at the first position by the moving means, from the moving means. It is characterized by comprising a regulating means capable of regulating a force acting on the peripheral surface of the second rotating body via the locking means.
The image forming apparatus according to another aspect of the present invention is an image forming apparatus including an image forming means for forming an image on a sheet and a drive control mechanism, and the drive control mechanism is a drive means and a drive control mechanism. It has a first rotating body that rotates by a driving force from the driving means, a peripheral surface that surrounds the axis of the first rotating body, and a locking portion provided on the peripheral surface, and is driven by the driving means. It is movable between a second rotating body that rotates by force, a first position that can engage with the locking portion, and a second position that is disengaged from the locking portion, and engages with the second rotating body. The locking means capable of positioning the first rotating body by stopping, the transmission state in which the driving force from the driving means is transmitted to the first rotating body and the second rotating body, and the transmission state are released. The drive transmission means for switching from the transmission state to the release state when the second rotating body is locked by the locking means, and the locking means. A moving means that can move from the second position to the first position, and a state in which the locking means is held at the first position by the moving means, from the moving means via the locking means. It is characterized by comprising a regulating means capable of regulating a force acting on the peripheral surface of the second rotating body.

By the present invention lever, it is possible to improve the stability of the operation.

The schematic diagram which shows the structure of the printer which concerns on 1st Embodiment. The schematic diagram which shows the structure of the printer which concerns on 1st Embodiment. Exploded view of the switching mechanism according to the first embodiment. Exploded view of the switching mechanism according to the first embodiment. A side view (a) of the switching mechanism according to the first embodiment, and a schematic view (b) showing a main part of the switching mechanism. Regarding the switching mechanism according to the first embodiment, a side view (a) showing the first stage of the switching operation and a schematic view (b, c) showing a main part of the switching mechanism. The side view which shows the 2nd stage of the switching operation about the switching mechanism which concerns on 1st Embodiment. Regarding the switching mechanism according to the first embodiment, a side view (a) showing a state after the switching operation is completed, and a schematic view (b) showing a main part of the switching mechanism. The side view which shows an example of the state before the initialization operation about the switching mechanism which concerns on 1st Embodiment. The side view which shows the 1st stage of the initialization operation about the switching mechanism which concerns on 1st Embodiment. The side view which shows the 2nd stage of the initialization operation about the switching mechanism which concerns on 1st Embodiment. The side view which shows the 3rd stage of the initialization operation about the switching mechanism which concerns on 1st Embodiment. The side view which shows the 4th stage of the initialization operation about the switching mechanism which concerns on 1st Embodiment. A side view (a) and a schematic view (b) for explaining the force acting on the cam disk during the initialization operation of the switching mechanism according to the first embodiment. The side view of the switching mechanism which concerns on 2nd Embodiment. The perspective view of the switching mechanism which concerns on 3rd Embodiment. The side view of the switching mechanism which concerns on 3rd Embodiment. A side view (a) and a cross-sectional view (b) of the clutch mechanism of the switching mechanism according to the third embodiment. The perspective view of the clutch mechanism of the switching mechanism which concerns on 3rd Embodiment. A side view (a) and a cross-sectional view (b) of the clutch mechanism of the switching mechanism according to the third embodiment. The side view for demonstrating the force acting on the cam disk in the middle of the initialization operation about the switching mechanism which concerns on 3rd Embodiment. The perspective view of the switching mechanism which concerns on 3rd Embodiment.

Hereinafter, the drive control mechanism according to the present disclosure will be described with reference to the drawings.

First, the configuration of a laser beam printer (hereinafter referred to as a printer) 1 which is an example of an image forming apparatus will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, the printer 1 roughly includes an image forming unit 4, a sheet conveying unit 5, a sheet ejection reversing unit 6, and a control unit 7. The sheet S used as a recording material is paper such as paper and envelopes, plastic film such as sheets for overhead projectors (OHP), and recording media such as cloth.

The sheet feeding unit 3 has a feeding cassette 21 as a seat storage section and a feeding roller 30 as a feeding means for feeding the sheet S stored in the sheet storage section. The feeding cassette 21 has a middle plate 32 that can be raised and lowered while supporting a bundle of sheets S, and is attached to a printer main body 2 that is a main body of an image forming apparatus so that it can be pulled out. The feeding roller 30 comes into contact with the uppermost sheet S as the middle plate 32 rises, and feeds the sheet S toward the sheet conveying section 5. Further, the sheet feeding section 3 is provided with a separating section 31 capable of separating the sheet S conveyed by the feeding roller 30 from other sheets. The separation unit 31 is composed of a separation pad 31b facing the outer peripheral surface of the feeding roller 30 and a separation holder 31a for pressing the separation pad 31b against the feeding roller 30. Therefore, the sheets S housed in the feed cassette 21 are delivered to the sheet transport unit 5 in a state of being separated one by one. The separation unit 31 is an example of a separation mechanism capable of separating sheets, and other separation mechanisms such as a retard roller method and an air feeding method may be used.

The image forming unit 4 provided as the image forming means has an electrophotographic structure. That is, the image forming unit 4 includes a photosensitive drum 40 which is a drum-shaped photoconductor, a laser scanner unit 41, a developing unit 42, a transfer roller 43, and a fixing unit 44. When the printer 1 is requested to start the image forming operation, a charging device (not shown) uniformly charges the surface of the photosensitive drum 40. The laser scanner unit 41 irradiates the photosensitive drum 40 with laser light based on the image information received by the control unit 7 from an external computer or an image reading device, and forms an electrostatic latent image on the drum surface. The developing unit 42 supplies toner to the photosensitive drum 40 to develop an electrostatic latent image into a toner image. The toner image supported on the photosensitive drum 40 is transferred to the sheet S by the transfer bias voltage applied to the transfer roller 43. The sheet S to which the unfixed toner image is transferred is delivered to the fixing portion 44. The fixing portion 44 includes a roller pair that sandwiches and conveys the sheet S and a heat source (not shown), and applies heat and pressure to the toner particles to fix the toner image on the sheet S.

The control unit 7 includes a CPU, which is a central processing unit, and a memory such as a ROM and a RAM, and controls the operation of each unit of the printer 1 by reading and executing a program stored in the ROM or the like. The image forming unit 4 is an example of an image forming means, and may be an electrophotographic method provided with an intermediate transfer body such as an intermediate transfer belt, or may be replaced with another known image forming mechanism such as an inkjet method.

The sheet transport unit 5 is a sheet transport device including a first transport path 50, a second transport path 51, a transport roller pair 52, and a re-transport roller pair 53. The first transport path 50 is a transport path for forming an image on the sheet S. That is, the sheet S fed from the feed cassette 21 by the feed roller 30 is supplied to the image forming unit 4 through the first transport path 50. A transport roller pair 52, a photosensitive drum 40 and a transfer roller 43, and a roller pair of the fixing portion 44 are arranged on the path of the first transport path 50. The sheet S forms an image on one surface in the process of being sequentially delivered to these roller pairs and conveyed upward in the drawing.

The second transport path 51 is a transport path for re-transporting the sheet S having an image formed on one side to the first transport path 50 when double-sided printing is performed. The second transport path 51 extends downward in the drawing from the sheet discharge reversing portion 6 provided downstream of the first transport path 50, and joins the first transport path 50 upstream of the transport roller pair 52. Further, in the second transport path 51, a re-transport roller pair 53 that receives the sheet S from the sheet discharge reversing portion 6 and delivers it to the transport roller pair 52 is arranged. The roller pairs (52, 40, 43, 44, 53) arranged in the first transport path 50 and the second transport path 51 are all examples of sheet transport means for transporting the sheet S.

The sheet discharge reversing unit 6 has a discharge roller pair 60, a reversing roller pair 70, and a switching flap 72. As shown in FIGS. 1 and 2, the switching flap 72 is a guide member capable of switching the transport path of the sheet S transported through the first transport path 50. That is, the switching flap 72 guides the sheet S to the first posture (FIG. 1) for guiding the sheet S to the first transport path toward the discharge roller pair 60 and the second transport path for guiding the sheet S to the reversing roller pair 70. It is possible to switch to the second posture (Fig. 2). The discharge roller pair 60 discharges the sheet S to the discharge tray 22 provided on the upper part of the printer main body 2. The reversing roller pair 70 is a roller pair capable of normal rotation and reversing, and switches back the sheet S received from the first transport path 50 and sends it to the second transport path 51.

[Switching mechanism]
Next, a drive control mechanism for switching the switching flap 72 between the first posture and the second posture will be described. As shown in FIGS. 3 and 4, the switching mechanism 71, which is the drive control mechanism according to the present embodiment, includes an input gear 82, a guide cam 83, a cam disc 84, a cam stopper 85, a solenoid unit 87, and a solenoid link 88. I'm out. However, FIGS. 3 and 4 are both exploded views of the switching mechanism 71.

The input gear 82 has gear teeth 82b that mesh with a drive gear connected to a drive source, and is rotatably supported by a gear shaft 89. The guide cam 83 and the cam disc 84 that receive the driving force from the input gear 82 and rotate are arranged on the same axis X1 as the gear shaft 89. Hereinafter, the direction of the axis X1 is referred to simply as "axial direction". The guide cam 83, the cam disc 84, and the cam stopper 85 form an integrally rotatable rotating unit. However, as will be described later, the cam disc 84 can rotate relative to the guide cam 83 within a predetermined range.

The guide cam 83 corresponds to a first rotating body that is rotated by a driving force transmitted from the input gear 82 and is positioned by another member of the switching mechanism 71. The input gear 82 and the drive source for driving the input gear 82 correspond to a drive means for driving the rotating body. As the drive source, for example, a stepping motor can be preferably used. Further, the drive of the input gear 82 by the drive source and the ON / OFF control of the solenoid unit 87 are performed by the control unit 7, which is an example of the control means capable of controlling these.

The guide cam 83 has a cam surface 83a that abuts on the flap link 72b integrally provided on the switching flap 72, and is a rotating member that can rotate about the axis X1. The flap body of the switching flap 72 and the flap link 72b are integrally formed via the flap shaft 72a and can rotate about the flap shaft 72a. The cam surface 83a is formed to have a different outer diameter according to the rotation phase of the guide cam 83, and the switching flap 72 is moved from one of the first position and the second position to the other each time the guide cam 83 rotates half a turn. It is set to let. A spring (not shown) is connected to the switching flap 72, and the flap link 72b is pressed against the cam surface 83a by the urging force of the spring.

The cam stopper 85 is a swinging member that can swing around the shaft portion 83b provided on the guide cam 83, that is, about the axis X2 of the shaft portion 83b that moves with the rotation of the guide cam 83. .. The inner peripheral portion of the input gear 82 (the back side of the gear teeth 82b) is provided with an engaging surface 82a having periodic irregularities formed in the circumferential direction, and the end portion of the cam stopper 85 is engaged with the engaging surface 82a. An engaging portion 85b that can be fitted is provided. The cam stopper 85 can swing between an engaging position where the engaging portion 85b engages with one of the irregularities of the engaging surface 82a and a disengagement position where the engaging portion 85b disengages from the engaging surface 82a. .. A stopper spring 86 is stretched between the end of the cam stopper 85 opposite to the engaging portion 85b and the protrusion 83c provided on the guide cam 83. The stopper spring 86 corresponds to an urging means for urging the cam stopper 85 from the disengaged position to the engaging position.

When the cam stopper 85 is in the engaging position, the driving force of the input gear 82 is transmitted to the guide cam 83 via the contact portion between the engaging portion 85b and the engaging surface 82a, and the input gear 82 and the guide cam 83 are moved. It rotates integrally. On the other hand, when the cam stopper 85 is in the detached position, the guide cam 83 and the input gear 82 can rotate relative to each other, and the transmission of the driving force to the guide cam 83 is released. That is, the cam stopper 85 corresponds to a drive transmission means capable of taking a transmission state (engagement position) in which the driving force of the input gear 82 is transmitted to the guide cam 83 and a release state (disengagement position) in which the transmission state is released. ..

The cam disc 84 is arranged between the input gear 82 and the guide cam 83 in the axial direction. A plurality of cylindrical portions 84e formed in a cylindrical shape centered on the axis X1 are provided on the outer peripheral portion of the cam disk 84, and a plurality of cylindrical portions 84e are locked on the outer peripheral surface and the inner peripheral surface of the cylindrical portion 84e by solenoid links 88. The locking portions 84a, 84b, 84c of the above are projected. Hereinafter, the outer peripheral surface and the inner peripheral surface of the cam disk 84 shall refer to the outer peripheral surface and the inner peripheral surface of the cylindrical portion 84e. As will be described in detail later, the cam disk 84 acts as a drive release means capable of switching the cam stopper 85 from the transmission state to the release state when locked by the solenoid link 88.

Here, the positional relationship between the cam disc 84 and the guide cam 83 will be described. The cam stopper 85 has a boss 85a that projects axially from the engaging portion 85b, and the cam disk 84 is formed with an elongated hole 84d that fits into the boss 85a. The elongated hole 84d extends in a direction inclined with respect to the radial direction centered on the axis X1 and has a moving distance of the engaging portion 85b when the cam stopper 85 swings between the engaging position and the disengaging position. It is set to the corresponding length.

Therefore, the cam disc 84 and the guide cam 83 can rotate relative to each other within a certain range as the cam stopper 85 swings. That is, when the cam stopper 85 moves between the engaging position and the disengaging position, the boss 85a moves along the longitudinal direction of the elongated hole 84d. At this time, the guide cam 83 and the cam disc 84 are displaced by an angle about the axis X1 of the locus on which the boss 85a has moved. Therefore, the cam disc 84 and the guide cam 83 rotate relative to each other within the range in which the boss 85a of the cam stopper 85 is regulated by the elongated hole 84d. In other words, the elongated hole 84d acts as a regulating unit that regulates the range in which the cam disc 84 and the guide cam 83 can rotate relative to each other.

The solenoid unit 87 includes a frame 87d fixed to the frame of the printer main body 2, a solenoid 87s held by the frame 87d, and a flap 87a attracted by the magnetic force generated by the solenoid 87s. The flap 87a, which is a movable piece, is rotatably supported by the frame 87d around the fulcrum 87c. A tension spring 87b as an urging member is stretched between the flap 87a and the frame 87d to urge the flap 87a in a direction away from the solenoid 87s.

The solenoid link 88 driven by the solenoid unit 87 is an example of a locking means capable of locking the cam disk 84. The solenoid link 88 includes a first locking claw 88b and a second locking claw 88c (see FIG. 5A) that can be engaged with the locking portions 84a, 84b, 84c of the cam disk 84, and the link shaft 88a is provided. It can swing in the radial direction with respect to the cam disk 84 at the center. The solenoid link 88 and the tip end portion 87f of the flap 87a are connected by a link spring 90, and the flap 87a is provided with a contact portion 87e capable of contacting the solenoid link 88. When the solenoid portion 87 is energized, the flap 87a is attracted to the solenoid 87s, and the solenoid link 88 is pulled by the link spring 90 to be urged outward in the radial direction with respect to the cam disk 84. Further, when the solenoid portion 87 is in the non-energized state, the contact portion 87e of the flap 87a urged by the tension spring 87b presses the solenoid link 88, so that the solenoid link 88 is radial with respect to the cam disk 84. It is urged inward.

As shown in FIG. 5A, the locking portions (84a, 84b, 84c) of the cam disk 84 are arranged separately on the inner peripheral surface 84f and the outer peripheral surface 84g of the cylindrical portion 84e. That is, the attitude-changing locking portions 84a and 84b used for the attitude-changing operation of switching the attitude of the switching flap 72 are projected from the outer peripheral surface 84g and are used for the initialization operation of the switching mechanism 71. The portion 84c projects from the inner peripheral surface 84f. The locking portion 84a is a locking portion corresponding to the first posture of the switching flap 72, and the locking portion 84b is a locking portion corresponding to the second posture of the switching flap 72.

The solenoid link 88 is either a first position that can be engaged with the locking portion 84c for initialization by the first locking claw 88b, or the locking portions 84a and 84b for changing the posture by the second locking claw 88c. It is movable to and from a second position where it can engage with the claw. That is, the locking portion 84c corresponds to the first locking portion that can be engaged with the locking means located at the first position, and the locking portions 84a and 84b are engaged with the locking means located at the second position. Corresponds to the second locking portion that can be fitted.

[Switching flap switching operation]
Hereinafter, the switching operation in which the switching mechanism 71 switches the posture of the switching flap 72 will be described with reference to FIGS. 5 to 8. However, FIG. 5A shows a state before the switching operation in which the switching flap 72 is held in the first posture, FIG. 6A shows the first stage of the switching operation, and FIG. 7 shows the second stage of the switching operation, FIG. (A) is a side view showing a state after the switching operation in which the switching flap 72 is held in the second posture. 5 (b), 6 (b), (c), and 8 (b) are schematic views showing the cam stopper 85 and the cam disc 84 in each operation stage.

As shown in FIG. 5A, in the state before the switching operation, the solenoid unit 87 is held in the non-energized state, and the solenoid link 88 is held in the second position by the urging force of the tension spring 87b. That is, in this state, the second locking claw 88c of the solenoid link 88 is in contact with the outer peripheral surface 84g of the cam disk 84 and is engaged with the locking portion 84a corresponding to the first posture. As a result, the rotation of the cam disk 84 in the arrow R1 direction is restricted. At this time, the flap link 72b is pressed against the small diameter portion of the cam surface 83a by the urging force of a spring (not shown), and the switching flap 72 is held in the first posture.

Further, as shown in FIG. 5B, in the state before the switching operation, the cam stopper 85 is held at the detached position, and the drive transmission to the guide cam 83 is released. The stopper spring 86 applies an urging force to the cam stopper 85 in the direction of the arrow R2 toward the engaging position, but the flap link 72b regulates the rotation of the cam disc 84, so that the cam stopper 85 swings. Is regulated.

As shown in FIG. 6A, when the switching operation is performed, the solenoid unit 87 is energized for a short time based on the command from the control unit 7 of the printer 1. As a result, the flap 87a is attracted to the solenoid 87s, and the solenoid link 88 swings in the direction of arrow R3 toward the first position via the link spring 90. Then, the solenoid link 88 is disengaged from the locking portion 84a, and the cam disk 84 becomes rotatable.

As shown in FIG. 6C, when the cam disc 84 is unlocked, the cam stopper 85 swings in the direction of arrow R2 from the disengagement position to the engagement position due to the urging force of the stopper spring 86. At this time, as shown in FIG. 6B, the boss 85a of the cam stopper 85 moves while sliding in contact with the peripheral wall of the elongated hole 84d of the cam disc 84, so that the cam disc 84 rotates in the direction of arrow R1. As a result, the input gear 82 and the guide cam 83 are connected via the cam stopper 85, and the cam disc 84 is further connected to the input gear 82 via the contact portion between the boss 85a of the cam stopper 85 and the elongated hole 84d. It will be in the state of being.

Then, as the input gear 82 rotates, the guide cam 83 and the cam disc 84 start to rotate integrally in the direction of arrow R1. At this time, as the guide cam 83 rotates, the cam surface 83a presses the flap link 72b, so that the switching flap 72 starts to rotate from the first posture to the second posture. The drive source for driving the input gear 82 is controlled so as to start driving substantially at the same time as the energization of the solenoid unit 87, for example.

As shown in FIG. 7, the energization of the solenoid unit 87 is cut off at the timing when the first set time T1 has elapsed from the start of energization. Then, the solenoid link 88 swings in the direction of arrow R4 about the link shaft 88a toward the second position by the urging force of the tension spring 87b, and comes into contact with the outer peripheral surface 84g of the cam disk 84. The first set time T1 is set shorter than the time when the locking portion 84b corresponding to the second posture reaches the position facing the second locking claw 88c. Therefore, as shown in FIG. 8A, the locking portion 84b is locked by the second locking claw 88c of the solenoid link 88 held at the second position, so that the locking portion 84b is locked in the direction of the arrow R1 of the cam disk 84. Stops rotating.

At the timing when the rotation of the cam disk 84 is stopped, the cam stopper 85 is in the engaging position, and the guide cam 83 receives the driving force from the input gear 82 and continues to rotate in the arrow R1 direction. Then, as shown in FIG. 8B, the cam stopper 85 moves from the engaging position to the disengaging position as the cam disc 84 and the guide cam 83 rotate relative to each other. That is, since the cam stopper 85 tries to move in the direction of arrow R1 while the position of the elongated hole 84d is fixed, the boss 85a is guided along the elongated hole 84d and the cam stopper 85 is directed toward the detached position in the direction of arrow R5. Swing to.

As a result, the drive transmission from the input gear 82 to the guide cam 83 is released, and the rotation of the guide cam 83 is stopped. At this time, the stopper spring 86 is stretched as the cam stopper 85 swings, and a force for moving the cam stopper 85 to the engaging position is charged. The switching flap 72 is held in the second posture by pressing the flap link 72b against the cam surface 83a of the guide cam 83 by a spring (not shown). As a result, the operation of switching from the first posture to the second posture is completed.

After the switching operation is completed, the rotation of the guide cam 83 is regulated by the flap link 72b as in the case before the switching operation, and the phase difference between the guide cam 83 and the cam disk 84 is fixed. That is, after the switching operation is completed, the released state in which the drive transmission from the input gear 82 to the guide cam 83 is released is maintained. Therefore, the drive source for driving the input gear 82 can be stopped at an arbitrary timing after the switching mechanism 71 is released. For example, it is preferable to stop the drive source at the timing required from the start of energization of the solenoid unit 87 and the start of driving the drive source to the time required for the cam stopper 85 to move to the detached position again.

The switching operation when the switching flap 72 is switched from the second posture to the first posture is the same as the above-mentioned operation except for the moving direction of the flap link 72b. That is, the solenoid unit 87 is energized for the length of the first set time T1 in accordance with the start of driving the input gear 82. Then, the lock of the cam disc 84 is released, the cam disc 84 rotates relative to the guide cam 83, and the cam stopper 85 moves from the disengaged position to the engaging position. As a result, the guide cam 83 and the cam disc 84 rotate integrally with the input gear 82, and the flap link 72b moves along the cam surface 83a, so that the switching flap 72 switches to the first posture. After that, when the locking portion 84a corresponding to the first posture is locked by the solenoid link 88, the rotation of the cam disk 84 is stopped. Then, after the cam stopper 85 moves to the detached position with the rotation of the guide cam 83, the rotation of the guide cam 83 is stopped in a state where the switching flap 72 is changed to the first posture.

The first set time T1 is set shorter than the time from when the cam disk 84 starts rotating until the locking portion 84c for initialization reaches the position of the first locking claw 88b. Therefore, during the switching operation of the switching flap 72 from the second posture to the first posture, the solenoid link 88 engages with the locking portion 84c for initialization, and the rotation of the cam disk 84 and the guide cam 83 is stopped. Can be avoided.

In this way, the switching mechanism 71 performs a switching operation of switching the posture of the switching flap 72 by performing ON / OFF control of the solenoid unit 87 and rotation control of the input gear 82 based on the command from the control unit 7. Run. Then, at the end of the switching operation, the cam stopper 85 moves to the detached position and is held in the detached position until the next switching operation. That is, at the timing of starting the next switching operation, the switching mechanism 71 is in a state in which the drive transmission is released, and the input gear 82 is in a state of idling with respect to the guide cam 83. Further, in this state, a force corresponding to the urging force of the stopper spring 86 acts from the locking portions 84a and 84b on the solenoid link 88 that locks the cam disk 84. The urging force of the stopper spring 86 is sufficient to rotate the cam disk 84 so that the locking portions 84a and 84b pass through the second locking claw 88c when the solenoid link 88 is released. is there. Therefore, when the solenoid unit 87 is energized, the force applied from the cam disk 84 to the solenoid link 88 is small, so that the cam disk 84 is unlocked even when the output of the solenoid unit 87 is small. That is, the cost can be reduced by using a solenoid having a small output while ensuring the stability of the switching operation.

[Initialization operation of switching mechanism]
Subsequently, the initialization operation of the switching mechanism 71 will be described with reference to FIGS. 9 to 14. If a failure occurs during the switching operation, it is conceivable that the switching flap 72 stops at an unspecified position different from the first posture or the second posture. Therefore, the switching mechanism 71 is configured to be able to execute an initialization operation in which the switching mechanism 71 and the switching flap 72 are in the initial state. In this embodiment, the switching flap 72 is held in the first posture, the first locking portion 84a of the cam disk 84 is locked by the solenoid link 88, and the switching mechanism 71 is in the drive release state. It is set as the initial state.

FIG. 9 is a side view showing a switching mechanism 71 in which the cam disk 84 is stopped in an unspecified position. However, the following initialization operation can be applied even when the cam disk 84 is stopped at an arbitrary position other than the position shown in the drawing. In the state before the start of the initialization operation shown in FIG. 9, the solenoid unit 87 is in a non-energized state, and the first locking claw 88b of the solenoid link 88 is in contact with the outer peripheral surface of the cam disk 84. Even if the input gear 82 is driven to rotate the cam disk 84 in this state, it is unknown which of the locking portions 84a and 84b for changing the posture the second locking claw 88c engages.

When performing the initialization operation, as shown in FIG. 10, the control unit 7 of the printer 1 starts energizing the solenoid unit 87 and also starts driving the input gear 82. Then, the flap 87a is sucked by the solenoid 87s, and the solenoid link 88 is urged by the link spring 90, so that the flap 87a swings in the direction of arrow R3 about the link shaft 88a. As a result, the solenoid link 88 moves to the first position, and the first locking claw 88b comes into contact with the inner peripheral surface 84f of the cam disk 84. Further, the cam stopper 85 is located at the engaging position in the state before the initialization operation, or moves to the engaging position when the cam disk 84 is released from the lock by energizing the solenoid portion 87. Therefore, the guide cam 83 and the cam disc 84 rotate in the arrow R1 direction as the input gear 82 rotates.

The control unit 7 rotates the input gear 82 while continuing to energize the solenoid unit 87 until the second set time T2, which is set longer than the time required for the cam disk 84 to rotate once, elapses. .. Then, as shown in FIG. 11, the cam disk 84 rotates while the inner peripheral surface 84f is in sliding contact with the first locking claw 88b while the solenoid link 88 is held at the first position. Then, as shown in FIG. 12, the locking portion 84c for initialization is locked by the first locking claw 88b at any time until the energization of the solenoid portion 87 is completed. Hereinafter, the position of the cam disk 84 in which the locking portion 84c for initialization is locked by the solenoid link 88 is set as the initialization standby position. After the cam disc 84 is stopped, the guide cam 83 is released from the input gear 82 by the cam stopper 85 moving to the detached position and stops rotating.

As shown in FIG. 13, the control unit 7 shuts off the energization of the solenoid unit 87 at the timing when the second set time T2 has elapsed from the start of energization. Then, the solenoid link 88 moves from the first position to the second position by the urging force of the tension spring 87b, the first locking claw 88b is released from the locking portion 84c for initialization, and the second locking is performed. The claw 88c comes into contact with the outer peripheral surface 84g of the cam disk 84. Further, the urging force of the stopper spring 86 causes the cam stopper 85 to swing from the disengaged position to the engaging position, and the cam disc 84 rotates in the direction of arrow R1 accordingly. Then, as the input gear 82 rotates, the guide cam 83 and the cam disc 84 resume rotation in the direction of arrow R1.

After that, when the locking portion 84a comes into contact with the second locking claw 88c as the cam disc 84 rotates, the cam disc 84 is locked by the solenoid link 88, and the rotation of the cam disc 84 stops. After the cam disc 84 is stopped, the guide cam 83 stops rotating when the cam stopper 85 moves to the detached position. At this time, the guide cam 83 keeps the switching flap 72 in the first posture, which is the initial position. That is, the switching mechanism 71 and the switching flap 72 return to the initial state (see FIG. 5A), and the initialization operation of the switching mechanism 71 is completed.

As described above, the switching mechanism 71 according to the present embodiment can execute both the switching operation and the initialization operation by changing the energization time of the solenoid unit 87. That is, in the initialization operation, the solenoid unit 87 is energized during the second set time T2, which is longer than the length corresponding to one rotation of the cam disk 84, so that the cam is cam regardless of the position before the initialization operation. The disk 84 is moved to the initialization standby position. Further, in the switching operation, by energizing the solenoid only during the relatively short first set time T1, the solenoid link 88 is rotated at the timing when the cam disk 84 is rotated by the interval of the locking portions 84a and 84b for changing the posture. It is configured to be locked by.

[Action of regulatory measures]
Here, the force acting on the cam disk 84 while the initialization operation is in progress will be described with reference to FIG. FIG. 14A is a side view showing a state in which the cam disk 84 is being rotated to the initialization standby position while the solenoid link 88 is held at the first position in the initialization operation. b) is a schematic view of the stopper spring 86 in this state.

As shown in FIG. 14A, the magnitude of the force with which the link spring 90 pulls the solenoid link 88 while the solenoid unit 87 is energized is defined as F2. Further, the magnitude of the normal force received by the inner peripheral surface 84f of the cam disk 84 from the second locking claw 88b of the solenoid link 88 is set to N1, and the first locking claw 88b of the solenoid link 88 and the inner peripheral surface of the cam disk 84 are set to N1. The coefficient of friction with 84f is μ1. At this time, the frictional force F4 (= μ1 × N1) received from the first locking claw 88b acts on the cam disk 84.

Further, as shown in FIG. 14B, the magnitude of the urging force that the stopper spring 86 urges the cam stopper 85 in the state where the cam stopper 85 is in the engaging position is defined as F1. At this time, the magnitude of the torque that the cam stopper 85 can transmit to the cam disc 84 changes depending on the value of F1. That is, when F1 is small, the cam stopper 85 is in a detached position due to the force f1 received by the boss 85a from the peripheral wall of the elongated hole 84d even when the rotational resistance of the cam disk 84 in the direction of arrow R1 is relatively small. Will move to. On the other hand, when F1 is large, the cam stopper 85 stays at the engaging position against the force f1 received from the cam disc 84, so that the cam disc 84 is directed by the arrow R1 through the contact portion between the boss 85a and the elongated hole 84d. Power is transmitted. The inclination angle of the unevenness of the input gear 82 is set so as not to generate a moment centered on the shaft portion 83b with respect to the cam stopper 85 or to be sufficiently small. In this case, the upper limit of the torque that can be transmitted to the cam disc 84 is substantially determined by the urging force F1 of the stopper spring 86.

Here, assuming that the magnitude of the force in the arrow R1 direction received by the cam disc 84 via the cam stopper 85 is F3, it is necessary that F3 does not fall below the frictional force F4 in order for the cam disc 84 to continue rotating. Is. In other words, when the frictional force F4 acting on the cam disk 84, which is the second rotating body, from the locking means exceeds the force F3 for rotating the cam disk 84, the cam disk 84 is in the middle of the initialization operation. There is a risk that it will stop and the initialization operation will not end normally.

Therefore, in this embodiment, the solenoid link 88 as the locking means and the solenoid portion 87 as the moving means are connected by the link spring 90, and the link spring 90 is configured so as to satisfy the following equation (1). ing.
μ1 × N1 <F3 ・ ・ ・ (1)

In other words, when the solenoid link 88 is held in the first position, the magnitude of the force N1 acting on the inner peripheral surface 84f of the cam disk 84 from the solenoid unit 87 via the solenoid link 88 is regulated by the link as a regulating means. It is regulated by a spring 90. As a result, it is possible to avoid a situation in which the cam disk 84 is stopped during the initialization operation, and it is possible to improve the stability of the operation of the switching mechanism 71.

In order to avoid stopping the cam disk 84 during the initialization operation, it is conceivable to configure the stopper spring 86 so that the urging force F1 of the stopper spring 86 becomes a sufficiently large value. However, in this case, the force required to unlock the cam disk 84 by the locking means becomes large. That is, for example, in the initial stage of the switching operation shown in FIG. 5A, the solenoid link 88 moves against the frictional force f2 received from the cam disk 84 urged in the direction of arrow R1 by the urging force of the stopper spring 86. There is a need. The frictional force f2 in this case becomes a larger value as the urging force of the stopper spring 86 increases. Then, in order to reliably move the solenoid link 88, it becomes necessary to use the solenoid unit 87 having a large output, which causes an increase in cost.

On the other hand, according to the configuration of this embodiment, the force acting on the inner peripheral surface 84f of the cam disk 84 from the solenoid link 88 by a simple configuration in which the flap 87a of the solenoid portion 87 and the solenoid link 88 are connected by the link spring 90. Is being reduced. Thereby, the stability of the operation of the switching mechanism 71 can be improved with a simple and inexpensive configuration.

[Modification example]
In the first embodiment, the link spring 90 has been illustrated as an example of the regulating means, but it may be replaced with another elastic member. For example, a stretchable rubber material may be interposed between the flap 87a of the solenoid portion 87 and the solenoid link 88. Even with such a configuration, the force transmitted from the solenoid portion 87, which is a moving means, to the solenoid link 88, which is a locking means, is regulated, and the force acting from the solenoid link 88 on the inner peripheral surface 84f of the cam disk 84 is reduced. be able to.

Further, in the first embodiment, the first locking claw 88b of the solenoid link 88 held at the first position is described as facing the inner peripheral surface 84f of the cam disk 84, but the moving direction of the solenoid link 88. And the arrangement of the locking portions 84a to 84c may be changed as appropriate. For example, the locking portions 84c for initialization may be arranged on the outer peripheral surface 84g of the cam disk 84, and the locking portions 84a and 84b for changing the posture may be arranged on the inner peripheral surface 84f. In short, in the configuration in which the locking portion is arranged on the peripheral surface of the second rotating body, the force acting on the peripheral surface from the locking means may be regulated by the regulating means. Further, the member provided with the peripheral surface is not limited to the cylindrical member as in the above-mentioned cylindrical portion 84e, and may have another shape.

Further, in the first embodiment, the possibility that the rotation of the cam disk 84 is stopped mainly in the middle of the initialization operation is mentioned, but according to the above configuration, the cam disk 84 is sufficiently rotated at the start of the switching operation. The possibility of not doing so can also be reduced. That is, according to the configuration of the first embodiment, the stability of the operation of the drive control mechanism can be improved in the configuration in which the first rotating body is positioned by locking the second rotating body.

Next, the switching mechanism 100 according to the second embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in that a stop member 101 capable of contacting the solenoid link 102 is used as a regulating means for regulating the force acting on the peripheral surface of the second rotating body from the locking means. ing. Other components similar to those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

FIG. 15 is a side view of the switching mechanism 100 in a state where the solenoid unit 87 is energized and the solenoid link 102 is held at the first position. As shown in FIG. 15, a stop member 101 supported by a frame body of the printer main body 2 is arranged in the switching mechanism 100. The stopping member 101 corresponds to an abutting portion capable of abutting on the locking means held at the first position and restricting contact between the locking means and the peripheral surface of the second rotating body.

The solenoid link 102 is engaged with the flap 87a of the solenoid unit 87, and swings around the link shaft 102a in conjunction with ON / OFF of the solenoid unit 87. The stop member 101 is arranged at a position where it comes into contact with the solenoid link 102 and can be restricted from moving to the left in the drawing when the solenoid portion 87 is energized. As a result, the solenoid link 102 is held at a position where the first locking claw 88b is not in contact with the inner peripheral surface 84f of the cam disk 84 and can be engaged with the locking portion 84c for initialization.

With such a configuration, when the solenoid unit 87 is energized, the solenoid link 102 and the cam disk 84 are in a non-contact state, so that a frictional force acting as a rotational load acts on the cam disk 84 from the solenoid link 102. Can be regulated. Therefore, it is possible to avoid a situation in which the rotation of the cam disk 84 is stopped in a scene such as during the initialization operation. That is, according to the configuration of the present embodiment, the stability of the operation of the switching mechanism 71 can be improved with a simple and inexpensive configuration as in the first embodiment.

Next, the switching mechanism 109, which is the drive control mechanism according to the third embodiment, will be described with reference to FIGS. 16 to 22. The switching mechanism 109 according to the present embodiment is different from the above-described first and second embodiments in that the clutch mechanism 110 including the two missing tooth gears 111 and 112 is used. Other components similar to those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

First, the configuration of the clutch mechanism 110 will be described with reference to FIGS. 16 and 17. FIG. 16 is a perspective view of the switching mechanism 109, and FIG. 17 is a side view of the switching mechanism 109. As shown in FIG. 16, the clutch mechanism 110 includes a first missing tooth gear 111 and a second missing tooth gear 112 that are arranged coaxially and can rotate integrally. The first missing tooth gear 111 and the second missing tooth gear 112 both have tooth portions 111b and 112b that mesh with the tooth portions 115a of the input gear 115 as driving means and missing tooth portions 111a and 112 that do not mesh with the input gear 115. It has a and.

The first missing tooth gear 111 corresponds to a first rotating body positioned by the switching mechanism 109, and the second missing tooth gear 112 corresponds to a second rotating body provided with a locking portion. The tooth portions 111b and 112b correspond to the first tooth portion and the second tooth portion, and the missing tooth portions 111a and 112a correspond to the first missing tooth portion and the second missing tooth portion. Further, as will be described later, the tooth portions 111b, 112b and the missing tooth portions 111a, 112a are released from the transmission state and the transmission state in which the driving force from the input gear 115 is received according to the relative phases of the gears 111 and 112. It functions as a drive transmission means that switches to the released state.

The second missing tooth gear 112 includes a cylindrical cylindrical portion 112f, and a plurality of locking portions 112c, 112d, 112e are formed on the inner peripheral surface 112g and the outer peripheral surface 112h of the cylindrical portion 112f (FIG. 17). reference). The tooth-missing portions 112a of the second tooth-missing gear 112 are arranged at three positions facing the input gear 115 in a state where any of the locking portions 112c to 112e is locked by the solenoid link 88. Further, the missing tooth portions 111a of the first missing tooth gear 111 are arranged at three positions at equal intervals with the missing tooth portions 112a of the second missing tooth gear 112. The configuration of the solenoid link 88 as the locking means for locking the second missing tooth gear 112 and the solenoid portion 87 as the moving means is substantially the same as that of the first embodiment.

As shown in FIG. 17, the first missing tooth gear 111 is integrally formed with a recess 111c to which the stopper 113 can be engaged with a disk 111d formed at three locations on the outer peripheral portion. The recess 111c is arranged at a position where the missing tooth portion 111a of the first missing tooth gear 111 can be engaged with the stopper 113 while facing the input gear 115. In other words, the stopper 113 can be held at any of the three holding positions where the first missing tooth gear 111 does not mesh with the input gear 115 by engaging with any of the recesses 111c. The switching mechanism 109 switches the guide cam 83 as in the first embodiment by replacing the disc 111d or integrally forming the disc 111d and connecting the guide cam 83 to the first missing tooth gear 111. The driving force can be transmitted to a controlled object such as the flap 72.

Subsequently, a configuration for limiting the relative phases of the first missing tooth gear 111 and the second missing tooth gear 112 will be described with reference to FIGS. 18 to 20. 18 (a) and 20 (a) are side views of the clutch mechanism 110, and FIGS. 18 (b) and 20 (b) are the positions shown in FIGS. 18 (a) and 20 (b). It is sectional drawing of the clutch mechanism 110 in.

As shown in FIG. 18B, an urging spring 114 is arranged as an urging means between the first missing tooth gear 111 and the second missing tooth gear 112. The urging spring 114 is a spring member that connects the first support portion 111k provided on the first missing tooth gear 111 and the second support portion 112k provided on the second missing tooth gear 112. The urging spring 114 can urge the second missing tooth gear 112 in a predetermined rotation direction with reference to the first missing tooth gear 111, that is, in the direction of arrow R6 in the drawing.

Further, in the clutch mechanism 110, the first contact portion 111j and the second contact portion 111j of the first missing tooth gear 111 and the second A second contact portion 112j of the missing tooth gear 112 is provided. As shown in FIGS. 18A and 18B, the first contact portion 111j and the second contact portion 112j are separated from each other when the phases of the first missing tooth gear 111 and the second missing tooth gear 112 are aligned. It is arranged so that it will be in the state of being. Further, as shown in FIGS. 19 and 20 (a) and 20 (b), the first contact portion 111j and the second contact portion 112j have the phases of the first missing tooth gear 111 and the second missing tooth gear 112. They are arranged so as to come into contact with each other in a displaced state.

As a result, the first missing tooth gear 111 and the second missing tooth gear 112 have the urging spring 114 up to a predetermined angle, that is, up to the angle at which the first contact portion 111j and the second contact portion 112j come into contact with each other. Relative rotation according to the urging direction is allowed. In particular, as shown in FIG. 20B, when the first missing tooth gear 111 and the second missing tooth gear 112 are rotated relative to each other as much as possible, the missing tooth portions 111a and 112a of one of the gears when viewed from the axial direction. Is in a state of overlapping with the tooth portions 111b and 112b of the other gear. In this state, the first missing tooth gear 111 and the second missing tooth gear 112 connected by the contact portions 111j and 112j and the urging spring 114 behave as an integral rotating member.

[Switching operation]
Next, the switching operation of the switching mechanism 71 using the clutch mechanism 110 will be described. In the state before the switching operation, as shown in FIGS. 16 and 17, the solenoid unit 87 is held in the non-energized state, and the solenoid link 88 is held in the second position by the urging force of the tension spring 87b. In this case, the second locking claw 88c of the solenoid link 88 engages with the locking portion 112d of the second missing tooth gear 112, and the rotation of the second missing tooth gear 112 in the arrow R6 direction is restricted. Further, the first missing tooth gear 111 and the second missing tooth gear 112 face the input gear 115 at the missing tooth portions 111a and 112a, and the drive transmission from the input gear 115 is released. Further, the first missing tooth gear 111 is engaged with the stopper 113 at any recess 111c of the disc 111d.

When the switching operation is performed, the solenoid unit 87 is energized for a short time (first set time T1). As a result, the flap 87a is attracted to the solenoid 87s, the solenoid link 88 swings toward the first position via the link spring 90, and the solenoid link 88 is disengaged from the locking portion 112d. Then, the urging force of the urging spring 114 causes the second missing tooth gear 112 to rotate in the direction of arrow R6, the tooth portion 112b of the second missing tooth gear 112 meshes with the input gear 115, and the driving force from the input gear 115. The second missing tooth gear 112 starts to rotate.

After that, the first contact portion 111j of the first missing tooth gear 111 comes into contact with the second contact portion 112j of the second missing tooth gear 112 (see FIG. 20B). Then, the first missing tooth gear 111 is separated from the stopper 113, and the first missing tooth gear 111 and the second missing tooth gear 112 start to rotate integrally. The energization of the solenoid portion 87 is cut off before the missing tooth portion 112a corresponding to the locking portion 112e for initialization reaches the input gear 115. As a result, when the tooth missing portion 112a faces the input gear 115, the second tooth missing gear 112 receives the driving force from the first tooth missing gear 111 via the urging spring 114 to continue the rotation. Then, when the locking portion 112d is locked by the solenoid link 88, the rotation of the second missing tooth gear 112 is stopped. At this time, the second missing tooth gear 112 is in a state of facing the input gear 115 at the missing tooth portion 112a.

At the timing when the rotation of the second missing tooth gear 112 is stopped, the first missing tooth gear 111 meshes with the input gear 115 and continues to rotate until the missing tooth portion 111a faces the input gear 115. When the missing tooth portion 111a reaches the position facing the input gear 115, the drive transmission to the first missing tooth gear 111 is released, and the stopper 113 causes the first missing tooth gear 111 to move to the second missing tooth gear 112. It is held in a position where it is in phase with. As a result, the switching operation by the switching mechanism 109 is completed. The switching operation in the reverse direction, that is, the switching operation when switching from the state in which the locking portion 112d is locked by the solenoid link 88 to the state in which the locking portion 112c is locked is also in the same process as the above-mentioned operation. Will be done.

As described above, the switching mechanism 109 is configured to execute the switching operation by the ON / OFF control of the solenoid unit 87 and the rotation control of the input gear 115. Then, the first missing tooth gear 111 and the second missing tooth gear 112 are in a state of not engaging with the input gear 115 at the end of the switching operation, and this state is maintained until the next switching operation. In this state, a force corresponding to the urging force of the urging spring 114 acts on the solenoid link 88 from the locking portions 112c and 112d. The urging force of the urging spring 114 is sufficient to rotate the second missing tooth gear 112 to a position where it meshes with the input gear 115 when the solenoid link 88 is unlocked. Therefore, when the solenoid portion 87 is energized, the force applied from the second missing tooth gear 112 to the solenoid link 88 is small, so that the second missing tooth gear 112 is locked even when the output of the solenoid portion 87 is small. Is released. That is, the cost can be reduced by using a solenoid having a small output while ensuring the stability of the switching operation.

[Initialization operation of switching mechanism]
Subsequently, the initialization operation of the switching mechanism 109 will be described with reference to FIGS. 21 and 22. The second missing tooth gear 112 of the switching mechanism 109 according to the present embodiment is provided with a locking portion 112e for initialization, similarly to the cam disc 84 of the first and second embodiments. The locking portion 112e is arranged on the inner peripheral surface 112g of the cylindrical portion 112f of the second missing tooth gear 112, unlike the locking portions 112c and 112d used for the above-mentioned switching operation (see FIG. 19).

When the initialization operation is performed, as shown in FIG. 21, the solenoid unit 87 is energized and the input gear 115 is driven. Then, the flap 87a is sucked by the solenoid 87s, and the solenoid link 88 is urged by the link spring 90, so that the flap 87a swings in the direction of arrow R3 about the link shaft 88a. As a result, the solenoid link 88 moves to the first position, and the first locking claw 88b comes into contact with the inner peripheral surface 112g of the second missing tooth gear 112. Then, the urging force of the urging spring 114 causes the second missing tooth gear 112 to rotate relative to the first missing tooth gear 111, and as the input gear 115 rotates, the first missing tooth gear 111 and the second missing tooth gear 111 are missing. The tooth gear 112 starts rotating in the direction of arrow R6 (see FIG. 22).

After that, the input gear 115 is rotationally driven while the solenoid unit 87 is continuously energized until the second set time T2, which is set longer than the time required for the second missing tooth gear 112 to make one rotation, elapses. Will be done. As a result, the locking portion 112e for initialization comes into contact with the first locking claw 88b at any time until the energization of the solenoid portion 87 is completed, and the solenoid link 88 contacts the second missing tooth gear. 112 is locked in the initialization standby position. Further, when the first missing tooth gear 111 rotates to a position facing the input gear 115 in the missing tooth portion 111a after the second missing tooth gear 112 is stopped, the first missing tooth gear 111 is held by the stopper 113 and rotates. Stop.

When the energization to the solenoid unit 87 is cut off at the timing when the second set time T2 elapses from the start of energization, the solenoid link 88 moves from the first position to the second position, and the first locking claw 88b is initially set. It separates from the locking portion 112e for conversion. As a result, the urging force of the urging spring 114 causes the second missing tooth gear 112 to rotate relative to the first missing tooth gear 111, and is in a state of being meshed with the input gear 115 again. When the first missing tooth gear 111 and the second missing tooth gear 112 are rotationally driven by the input gear 115 and the locking portion 112c comes into contact with the second locking claw 88c, the second missing tooth gear 112 is engaged by the solenoid link 88. It will be stopped. The first missing tooth gear 111 continues to rotate even after the second missing tooth gear 112 is stopped, and is held by the stopper 113 with the missing tooth portion 111a facing the input gear 115. As a result, the switching mechanism 109 returns to the initial state (see FIGS. 16 and 17), and the initialization operation of the switching mechanism 109 is completed.

[Action of regulatory measures]
Here, the force acting on the second missing tooth gear 112 while the initialization operation is in progress will be described with reference to FIG. As shown in FIG. 21, the magnitude of the force with which the link spring 90 pulls the solenoid link 88 while the solenoid unit 87 is energized is F2'. Further, the magnitude of the normal force received from the second locking claw 88b of the solenoid link 88 to the inner peripheral surface 112g of the second missing tooth gear 112 is set to N2, and the first locking claw 88b and the second missing tooth of the solenoid link 88 are set to N2. The coefficient of friction of the gear 112 with the inner peripheral surface 112 g is set to μ2. At this time, the frictional force F7 (= μ2 × N2) received from the first locking claw 88b acts on the second missing tooth gear 112.

Further, when the urging spring 114 is compressed, the magnitude of the urging force received by the second missing tooth gear 112 from the first missing tooth gear 111 via the urging spring 114 is defined as F5 (FIG. 18B). reference). At this time, as shown in FIG. 21, in a state where the second missing tooth gear 112 is not meshing with the input gear 115, the force F6 in the arrow R6 direction received by the second missing tooth gear 112 via the urging spring 114. The size is determined by the size of F5. Then, when the frictional force F7 received from the solenoid link 88 by the second missing tooth gear 112 is larger than the force F6 trying to rotate the second missing tooth gear 112, the initializing operation is in progress. There is a risk that the rotation of the second missing tooth gear 112 will stop.

Therefore, in this embodiment, the solenoid link 88 as the locking means and the solenoid portion 87 as the moving means are connected by the link spring 90, and the link spring 90 is configured so as to satisfy the following equation (2). ing.
μ2 × N2 <F6 ・ ・ ・ (2)

In other words, in a state where the solenoid link 88 is held in the second position, the magnitude of the force N2 acting on the inner peripheral surface 112g of the second missing tooth gear 112 from the solenoid portion 87 via the solenoid link 88 is regulated by means for regulating the magnitude. It is regulated by the link spring 90 as. As a result, it is possible to avoid a situation in which the second missing tooth gear 112 is stopped during the initialization operation, and it is possible to improve the stability of the operation of the switching mechanism 109. Further, the operation of the switching mechanism 71 is performed while the urging force of the urging spring 114 is set to be small, that is, the drive load when the solenoid link 88 is disengaged from the locking portions 112c and 112d in the switching operation is suppressed. Stability can be improved. That is, according to the configuration of this embodiment, the operational stability of the switching mechanism 71 can be improved with a simple and inexpensive configuration.

In this embodiment, the link spring 90, which is an elastic member, is used as the regulating means. However, as in the stop member 101 of the second embodiment, the link spring 90 is brought into contact with the solenoid link 88 to regulate the swing range thereof. A contact portion may be arranged.

[Other Embodiments]
In the first to third embodiments, the case where the drive control mechanism is used as the switching mechanism for switching the posture of the switching flap 72 has been illustrated, but the present technology may be used as the drive control mechanism for other parts of the image forming apparatus. For example, in the feed cassette 21 (see FIG. 1), the middle plate 32 is moved up and down between the feed position where the sheet S abuts on the feed roller 30 and the standby position where the sheet S is separated from the feed roller 30. This technology may be used as a cam mechanism for making the cam mechanism. Further, it may be applied to a drive control mechanism for raising and lowering the feeding roller in a configuration provided with a feeding roller capable of raising and lowering the seat support portion such as a middle plate. Further, it may be applied to a roller pair drive control mechanism that can switch between a closed state in which the seat can be sandwiched between the nip portions and an open state in which the nip portion is open. The image forming apparatus may include an accessory device such as a sheet processing device or an optional sheet feeding device in addition to the main body of the device having a printing function. It may be applied.

1 ... Image forming apparatus (printer) / 4 ... Image forming means (image forming unit) / 5 ... Sheet conveying device (sheet conveying unit) / 7 ... Control means (control unit) / 71, 100, 109 ... Drive control mechanism ( Switching mechanism) / 72 ... Guide member (switching flap) / 82,115 ... Drive means (input gear) / 83,111 ... First rotating body (guide cam, first missing tooth gear) / 84,112 ... Second rotation Body (cam disc, second missing tooth gear) / 84a, 84b, 112c, 112d ... locking portion, second locking portion / 84c, 112e ... locking portion, first locking portion / 84d, 111j, 112j ... Regulatory part (long hole, contact part) / 84e, 112f ... Cylindrical part / 84f, 112g ... Peripheral surface (inner peripheral surface) / 85,111a, 111b, 112a, 112b ... Drive transmission means (cam stopper, missing tooth) Gear teeth and missing teeth) / 86,114 ... Biasing means (stopper spring, urging spring) / 87 ... Moving means (voltaic part) 87a ... Movable piece (flap) 87s ... solenoid / 88 ... Locking means (locking means (stopper spring, urging spring) / 87 ... Solvent link) / 90 ... Regulatory means, elastic member (link spring) / 101 ... Regulatory means, contact part (stop member)

Claims (11)

Sheet transporting means for transporting sheets and
A guide member changed to a first posture for guiding the sheet transported by the sheet transport means to the first transport path and a second posture for guiding the sheet to the second transport path.
A drive control mechanism for changing the posture of the guide member and
It is a sheet transfer device equipped with
The drive control mechanism is
Drive means and
A first rotating body that rotates by the driving force from the driving means, and
A second rotating body having a peripheral surface surrounding the axis of the first rotating body and a locking portion provided on the peripheral surface and rotating by a driving force from the driving means.
It is movable between a first position that can be engaged with the locking portion and a second position that is detached from the locking portion, and by locking the second rotating body, the first rotating body can be moved. Positionable locking means and
It is configured so that a transmission state in which the driving force from the driving means is transmitted to the first rotating body and the second rotating body and a release state in which the transmission state is released can be obtained, and the locking means is used. A drive transmission means that switches from the transmission state to the release state when the second rotating body is locked, and
A moving means capable of moving the locking means from the second position to the first position,
A regulating means capable of regulating a force acting on the peripheral surface of the second rotating body from the moving means via the locking means while the locking means is held at the first position by the moving means. And with
A sheet transfer device characterized by this. The moving means has a movable piece and a solenoid for driving the movable piece.
The regulating means has an elastic member interposed between the movable piece and the locking means.
The sheet transport device according to claim 1. The locking means is a swinging member that can swing between the first position and the second position.
The regulating means has a contact portion capable of restricting the locking means from coming into contact with the peripheral surface of the second rotating body by contacting the locking means located at the first position.
The sheet transport device according to claim 1 or 2, wherein the sheet transport device is characterized by the above. A control means capable of controlling the driving means and the moving means is provided.
The control means makes one rotation of the first rotating body and the second rotating body by the driving means while the locking means is held at the first position by the moving means. By driving for a time equal to or longer than the above, it is possible to execute an operation of engaging the locking means with the locking portion.
The sheet transport device according to any one of claims 1 to 3, wherein the sheet transport device is characterized by this . The locking portion is a first locking portion and
The second rotating body has second locking portions that can be engaged with the locking means held at the second position and are provided at a plurality of positions in the circumferential direction of the second rotating body.
The sheet transport device according to any one of claims 1 to 4, wherein the sheet transport device is characterized by this . The second rotating body has a cylindrical cylindrical portion that surrounds the axis of the first rotating body.
The peripheral surface is the inner peripheral surface of the cylindrical portion.
The first locking portion is projected inward in the radial direction from the inner peripheral surface.
The second locking portion projects radially outward from the outer peripheral surface of the cylindrical portion.
The sheet transporting apparatus according to claim 5. A regulating unit that allows relative rotation of the first rotating body and the second rotating body and restricts the relative rotation of the first rotating body and the second rotating body beyond a predetermined angle.
An urging means that is interposed between the first rotating body and the second rotating body and urges the second rotating body in a predetermined rotation direction with respect to the first rotating body is provided.
When the second rotating body is locked by the locking means, the drive transmitting means changes from the transmission state to the released state by rotating the first rotating body by the driving force from the driving means. When the second rotating body is switched and the locking of the second rotating body is released, the second rotating body is rotated by the urging force of the urging means to switch from the released state to the transmission state.
The sheet transport device according to any one of claims 1 to 6, wherein the sheet transport device is characterized by this . The driving means has a rotating member having irregularities formed on the inner peripheral portion, and has a rotating member.
The drive transmission means has an engageable engaging portion that engages with the unevenness of the drive means, and the engaging position at which the engaging portion engages with the unevenness by the first rotating body and the above. It is a swinging member that is swingably supported between the engaging portion and the disengagement position where it disengages from the unevenness.
The restricting portion is an elongated hole formed in the first rotating body, which engages with the swinging member and guides the swinging member to the engaging position and the disengaging position.
The urging means is a spring member that connects the first rotating body and the swinging member, and biases the second rotating body through a contact portion between the swinging member and the elongated hole.
The sheet transport device according to claim 7. The drive means has an input gear having a tooth portion on the outer peripheral portion, and has an input gear.
The first rotating body and the second rotating body are toothless gears that are rotationally driven by the input gear, respectively.
The drive transmission means includes a first tooth portion that meshes with the input gear, a first missing tooth portion that does not mesh with the input gear, and a second rotating body, which are provided on the outer peripheral portion of the first rotating body. It has a second tooth portion that meshes with the input gear and a second missing tooth portion that does not mesh with the input gear, which are provided on the outer peripheral portion.
The restricting portion is provided on the first rotating body and the second rotating body, and the phase difference between the first rotating body and the second rotating body is the predetermined angle. In some cases, it has a second contact portion that comes into contact with the first contact portion, and has a second contact portion.
The urging means is a spring member that connects the first rotating body and the second rotating body.
The sheet transport device according to claim 7. The sheet transport device according to any one of claims 1 to 9,
An image forming means for forming an image on a sheet is provided.
An image forming apparatus characterized in that. An image forming means for forming an image on a sheet, a drive control mechanism, and
It is an image forming apparatus equipped with
The drive control mechanism is
Drive means and
A first rotating body that rotates by the driving force from the driving means, and
A second rotating body having a peripheral surface surrounding the axis of the first rotating body and a locking portion provided on the peripheral surface and rotating by a driving force from the driving means.
It is movable between a first position that can be engaged with the locking portion and a second position that is detached from the locking portion, and by locking the second rotating body, the first rotating body can be moved. Positionable locking means and
It is configured so that a transmission state in which the driving force from the driving means is transmitted to the first rotating body and the second rotating body and a release state in which the transmission state is released can be obtained, and the locking means is used. A drive transmission means that switches from the transmission state to the release state when the second rotating body is locked, and
A moving means capable of moving the locking means from the second position to the first position,
A regulating means capable of regulating a force acting on the peripheral surface of the second rotating body from the moving means via the locking means while the locking means is held at the first position by the moving means. And with
An image forming apparatus characterized in that.

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