JP2006266400A - Clutch mechanism and powder conveyance device and sheet conveyance device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clutch mechanism having an inexpensive and simple configuration. <P>SOLUTION: This clutch mechanism has a chipped tooth gear connected with and driven to a driven side and having a chipped tooth region without tooth in at least one section of the outer periphery, a planetary gear movable in a predetermined area in substantially circumferential direction of the chipped tooth gear and capable of inputting drive into the chipped tooth gear by opposing to the chipped tooth gear, a driving means for rotating and driving the planetary gear, and a locking means for locking a position of the planetary gear. The planetary gear is energized in one direction by self-weight or an energizing means. The locking means can lock travel of the planetary gear in the direction of energization. As a result, the clutch mechanism having the inexpensive and simple configuration and the powder conveyance device and the sheet conveyance device using the clutch mechanism are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a clutch mechanism, a powder conveying apparatus and a sheet conveying apparatus using the clutch mechanism.

  Regarding the present invention, the background art will be described using an image forming apparatus as an example. In consumer products such as image forming devices, in order to provide high-quality products at a low price, a drive system that was previously controlled by an expensive electromagnetic clutch or dedicated motor is combined with a toothless gear and a solenoid. A method of substituting an inexpensive mechanical clutch mechanism is generally employed.

  An example of a typical mechanical clutch mechanism is shown in FIG.

  When the elements are roughly classified, this mechanism is composed of a drive input gear 36, a control gear train 30, a driven gear 37, a biasing means 34, and a solenoid SL. The drive input gear 36 is drivingly connected to the motor. The driven gear 37 is drivingly connected to the driven side. The control gear train 30 includes a first toothless gear 31 facing the drive input gear 36, a second toothless gear 32 facing the driven gear 37, and a claw shape 33a for engaging with the solenoid SL, The cam portion 33 is integrally formed with a cam shape 33b for applying a rotational biasing force to the control gear train 30 by contact with the leaf spring 34 as the biasing means. The first segmented gear 31, the second segmented gear 32, and the cam portion 33 have a fixed phase relationship with each other and operate as a unit.

  When the solenoid SL is turned on and the engagement between the flapper 35 and the claw shape 33a is released, the control gear train 30 is unlocked and the control gear train 30 is rotated by the action of the biasing plate spring 34. When the first tooth 31a of the first toothless gear 31 meshes with the drive input gear 36, the control gear train 30 starts rotating by the drive supply of the drive input gear 36, and then the second toothless gear 32 is driven. Engage with 37. The second toothless gear 32 transmits the drive to the driven gear 37, and when the missing tooth portion returns to the position facing the drive input gear 36 again, the drive transmission to the driven gear 37 is cut off. Thereafter, the tooth missing portion of the first toothless gear 31 also returns to the position opposed to the drive input gear 36, so the drive connection between the first tooth missing gear 31 and the drive input gear 36 is also cut off, and the control gear train 30 is The biasing plate spring 34 returns to the standby phase that engages with the flapper 35 of the solenoid SL.

  In an image forming apparatus, this mechanism is widely employed particularly in a paper feeding device, in which a driven gear 37 is drivingly connected to a paper feeding roller or a pickup roller. Further, in many cases, a control cam for bringing the pickup roller into and out of contact with the surface of the sheet material stacked on the sheet stacking tray is integrally provided on the control gear train 30. The toothless gears and cams on the control gear train 30 can be driven with the same control profile every time by one rotation cycle control with the solenoid ON as a trigger. Can be controlled stably. Further, since the drive connection with the driven side is disconnected at the timing of the rotation start and rotation end of the first partial gear 31, the control operation itself is not affected by the drive load, and an operation margin is secured. Yes.

  However, since the conventional clutch mechanism described above is configured to drive the driven gear with the missing gear, the moment when the first tooth 32a of the second missing gear 32 meshes with the driven gear 37. The amount of rotation of the driven gear 37 varies each time depending on the phase relationship between the two and the presence or absence of tooth skipping of the first teeth 32 a when the second missing gear 32 and the driven gear 37 are engaged.

  In addition, since this variation accumulates as the operation is repeated, for example, like a toner replenishment mechanism of the image forming apparatus, every time the solenoid is turned on, a predetermined amount of toner is accurately replenished from the toner cartridge to the image forming unit. This method is not suitable for high-precision control such as managing the remaining amount of toner in the toner cartridge by monitoring the number of replenishment operations. Had to be monitored).

  As a mechanical clutch mechanism capable of increasing the control accuracy, there is a conventional example as shown in FIG. In this configuration, the control gear train 40 is made up of a toothless gear 41 facing the drive input gear 45, a claw shape 42 a for engaging with the flapper 44 of the solenoid SL, and a leaf spring 43 as an urging means. The cam portion 42 is integrally formed with a cam shape 42b for applying a rotation biasing force to the control gear train 40, and is always driven and connected to the driven side.

  This is different from the prior art in that the drive input gear 45 drives the toothless gear 41 directly connected to the driven side, and there is no variation in the amount of rotation for each rotation operation, and there is also a variation in the accumulated amount of rotation. not exist.

  However, in this mechanism, the control gear train 40 is always carrying the driven load on the driven side. Therefore, the setting of the urging force by the urging plate spring 43 must be adjusted so that the control gear 40 can be rotated by overcoming the driving load and less than the allowable load of the solenoid SL. There is a disadvantage that there are few.

  In a system in which the drive load on the driven side varies depending on the situation, it is particularly easy to exceed the operation margin, and as a result, the control gear train 40 does not return to the standby position and the final tooth 41a of the missing gear and the drive input gear 45 are not connected. Troubles that repeat the first contact, fatal troubles that cannot be started due to poor suction of the solenoid SL, and the like may occur. In the case of the toner replenishing device of the image forming apparatus mentioned above as an example, the load torque applied to the drive system differs greatly when the toner fluidity is good and when the toner is blocked after being left for a long period of time. For various applications, it was difficult to adopt due to the above problems.

JP-A-11-189338 JP 2000-118768 A

  As described above, in the conventional mechanical clutch mechanism, both “removal of rotation amount and cumulative rotation amount for each operation” and “stable operation that is not affected by load fluctuation on the driven side” must be compatible. I can't. Therefore, an electrical rotation amount detection means and a control means have to be provided, resulting in an increase in product cost. Development of an inexpensive and simple mechanical clutch mechanism that can solve this problem has been demanded.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an inexpensive and simple clutch mechanism, and a powder conveying apparatus and a sheet conveying apparatus using the clutch mechanism.

  In order to achieve the above-mentioned object, the present invention provides a missing tooth gear that is drivingly connected to a driven side and has a missing tooth region without teeth at at least one position on the outer periphery, and a predetermined area in a substantially circumferential direction of the missing tooth gear. A planetary gear that is movable within the planetary gear and capable of being input to the partial gear in opposition to the partial gear, driving means for rotationally driving the planetary gear, and locking the position of the planetary gear The planetary gear is biased in one direction by its own weight or biasing means, and the locking means can lock the movement of the planetary gear in the biasing direction. It is characterized by being.

  According to the present invention, a mechanical clutch mechanism that achieves both an accurate operation without variation in rotational amount and cumulative rotational amount for each operation and a stable operation that is not influenced by load fluctuation on the driven side, with an inexpensive and simple configuration. Can be realized.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS.

  FIG. 1 is an external view of a mechanical clutch mechanism according to the present invention.

  The drive output shaft 11 is a rotatable shaft that is drivingly connected to the driven side, and the toothless gear 2 is fixed to the drive output shaft 11. The idler gear 10 is rotatably mounted on the drive output shaft 11, receives the drive supply from the motor M, and transmits the rotational drive to the planetary gear 1.

  The planetary gear 1 is supported by a swing arm 3 that can swing around a drive output shaft 11. The swing arm 3 is restricted in its swingable limit angle region by the engagement relationship between the protrusion 3b formed on the swing arm 3 and the elongated hole 13a formed on the drive side plate 13. The planetary gear 1 is movable within the movable area set thereby.

  Hereinafter, in the movable area of the planetary gear 1, the end on the biasing direction side is defined as “start end”, and the end in the direction opposite to the bias is defined as “end”. The planetary gear 1 is disposed so as to be able to mesh with both the idler gear 10 and the toothless gear 2. The swing arm 3 that swings and supports the planetary gear 1 is biased clockwise by a biasing spring 4 in the left view of FIG. 1 (counterclockwise in the right view of FIG. 1). The tooth tip shape of the toothless gear 2 is tapered so as not to cause contact with the tip when meshing with the planetary gear (in this embodiment, the teeth on the entire circumference are tapered). However, since it is a problem only at the time of meshing, essentially only the first 1-2 teeth are sufficient).

  In addition, the mechanical clutch mechanism according to the present embodiment includes a control cam 5 that rotates in synchronization with the toothless gear 2 and a swing area of the swing arm 3 (= planetary gear 1) in conjunction with the control cam 5. A planetary gear position control mechanism (position control means) comprising a control lever 6 capable of variably controlling the movable area). The front end of the control lever 6 can be engaged with the engaging portion 3 c of the swing arm 3, and the swing arm 3 depends on the phase of the control cam 5 (that is, the phase of the missing gear 2). The swingable region is variably controlled.

  Here, the basic operation of the mechanical clutch mechanism according to the present embodiment will be described with reference to FIGS. The left diagram in each figure shows the positional relationship between the toothless gear and the planetary gear, and the right diagram shows the engagement relationship between the control cam and the control lever.

  In the standby state (see FIG. 2), the position of the swing arm 3 is locked by the flapper 12 of the solenoid SL, and the missing tooth gear 2 is held in a phase where the missing tooth portion faces the swing gear 1. ing. In this state, the control lever 6 is largely separated from the engaging portion 3a of the swing arm, and the movable area of the planetary gear 1 is maximized.

  When the solenoid SL is turned on, the flapper 12 and the swing arm claw portion 3c are disengaged, so that the planetary gear 1 moves toward the start end 13a by the urging of the urging spring 4 and Meshes with the teeth 2a (see FIG. 3). When the planetary gear 1 and the partial gear 2 mesh with each other, a rotational driving force corresponding to the driving load torque is generated between the idler gear 10 and the partial gear 2 via the planetary gear 1. At this time, in the planetary gear, a transmission force received from the idler gear and a reaction force received from the missing gear act. Although these two forces are theoretically offset, an interaxial force is generated between the idler gear, the toothless gear and the planetary gear due to the influence of the pressure angle of the gear accompanying the drive transmission. And although it is not large by the load resistance etc. resulting from this interaxial force, the force which moves a planetary gear to the movable area terminal end 13b side generate | occur | produces. Hereinafter, this force is defined as “the restoration torque of the planetary gear”.

  When the restoration torque of the planetary gear exceeds the urging force of the swing arm (see FIG. 4A), the planetary gear 1 and the toothless gear 2 mesh with each other, and the planetary gear 1 moves between the idler gear 10 and the toothless gear 2. It moves to the terminal end 13b together with the toothless gear 2 and the idler gear 10 while being relatively stopped with respect to both. Then, when the planetary gear 1 reaches the end 13b of the movable area, the swinging arm 3 receives the restoring torque applied to the planetary gear 1, and the planetary gear 1 starts to rotate the idler gear 10. Eventually, the rotation of the toothless gear 2 advances, and when the toothless portion returns to the position facing the planetary gear 1, the planetary gear 1 and the toothless gear 2 are disengaged and the drive is cut off. Along with this, the driving torque acting on the planetary gear 1 disappears, and the planetary gear 1 returns to the standby position by the action of the biasing spring 4.

  On the other hand, when the restoration torque of the planetary gear is less than the urging force of the swing arm (see FIG. 4B), the planetary gear 1 cannot move to the end 13b of the movable area and remains at the start end 13a. Then, the toothless gear 2 is driven to rotate. Eventually, the control lever 6 swings by the action of the control cam 5 and lifts the swing arm 3, so that the planetary gear 1 is forcibly moved to the vicinity of the end of the movable area (FIG. 5). When the protruding portion 6a of the control lever gets over the stepped portion 5a of the control cam immediately before the missing tooth portion of the missing gear 2 returns to the position facing the planetary gear 1, the control lever 6 and the swing arm 3 are moved. Is released, and the swing arm 3 returns to the standby position by the action of the biasing spring 4. At the same time, the planetary gear 1 and the toothless gear 2 are disengaged.

  With the above sequence, one rotation cycle control with the solenoid ON as a base point is performed.

  In order to realize the above operation, there are conditions that must be satisfied at least in design. First, the relationship between the missing tooth region of the missing gear 2, the movable area of the planetary gear 1, and the locking position by the solenoid SL will be described (see FIG. 6).

  The maximum movable angle range (from the start end to the end of the movable area) of the planetary gear 1 with respect to the center of the missing gear 2 is θ, the angular range in which the planetary gear 1 can move without meshing with the missing gear 2 is α, and the planetary gear 1 The angle from the end of the movable area to the locking position by the solenoid SL is β.

  When the solenoid is turned on next time after completion of one rotation cycle operation, the missing tooth gear 2 is always positioned at the position where the planetary gear 1 and the missing gear 2 can mesh with each other. I have to. Also, when the planetary gear 1 returns to the standby position, the first tooth 2a of the missing gear must not mesh with the planetary gear 1 before the solenoid is turned on next time. As described above, the angle α that defines the range of the missing tooth portion needs to satisfy the following condition.

β <α <θ
Next, conditions regarding the urging force of the swing arm will be described.

  The pitch circle radius of the toothless gear 2 is Rk, the pitch circle radius of the planetary gear 1 is Rs, the idling torque of the planetary gear 1 is Ts, and the swing direction of the force received by the swing arm 3 from the biasing spring 4 at the standby position F is the component, Ry is the distance from the pivot center of the swing arm 3 to the point of action of the biasing spring 4, and the pivot center moment of the swing mechanism generated by the weight of the swing arm 3 and the planetary gear 1 is It is assumed that My (My changes depending on the position of the swing arm, and is the maximum value in the moving area here).

  When each value is defined as described above, the force acting around the swing arm rotation center can be calculated as follows.

Moment that the swing arm 3 receives counterclockwise due to the idling torque of the planetary gear 1: (Ts / Rs) * Rk
Moment received by the oscillating arm 3 in the clockwise direction by the urging spring 4: F * Ry
Using the above, the condition for the rocking arm to be reliably urged clockwise in standby is
(Ts / Rs) * Rk <F * Ry + My
It becomes. Satisfying this condition is a condition for triggering the operation when the solenoid is turned on. Usually, since Ts is a sufficiently small value, this condition can be satisfied if it is designed normally. However, it is necessary to design in consideration of an increase in frictional resistance associated with continuous operation (not to mention the biasing force is It must be set to be within the allowable load of the solenoid).

  The basic operation of the mechanical clutch mechanism based on the present invention has been described above. Next, the concept of other disturbances is outlined.

  Depending on the application to the device, there may be cases where the drive system is not scheduled to be rotated from the output side, in addition to the normal usage where the drive system is rotated from the input side. For example, when the user deliberately operates the driven side, or the springback due to backlash or distortion of the driving system (when the driving connection is released and the driving load is released, the driven train on the driven side This phenomenon is a phenomenon that rotates in the opposite direction. In this embodiment, it is possible to cope with these cases without causing a problem. First, in the case where the output side is rotated in the forward direction (in the case where the drive output shaft 11 is rotated counterclockwise in FIG. 2), it is possible to return to the standby state at the same time as the motor is turned on, which is not a problem.

  On the other hand, even in the case where the output side is rotated in the reverse direction (when the drive output shaft 11 is rotated in the clockwise direction in FIG. 2), if the planetary gear 1 and the missing gear 2 mesh with each other, the motor is turned on at the same time. Automatically returns to the state. Even if the phase of the toothless gear 2 is moved within the range in which the two do not mesh, when the solenoid is turned on and the planetary gear 1 moves to the start end, it is designed to always mesh with the first tooth 2a of the toothless gear. Because it is, it can be operated without problems. The only countermeasure is required when the tooth missing gear 2 is moved and the phase of the tip of the last tooth of the tooth missing gear 2 and the tooth tip of the planetary gear 1 is just right. In this case, there is a possibility that an abnormal noise due to the contact between both teeth is generated.

  In the present embodiment, the above-described planetary gear position control mechanism prohibits reverse rotation of the missing gear 2 from the standby state to prevent this problem from occurring. Specifically, as can be seen from the right diagram in FIG. 2, when the drive output shaft 11 is rotated clockwise in the standby state, the control lever protrusion 6a and the control cam step 5a form a ratchet mechanism. Engage and lock its rotation.

  In addition, depending on use conditions, when the planetary gear 1 and the toothless gear 2 are engaged with each other, there is a possibility that the teeth of the planetary gear and the first tooth of the missing gear may continuously skip. . This phenomenon is more likely to occur when the planetary gear is smaller in diameter than the missing gear when the rotational speed of the planetary gear is high or the driven load on the driven side is large. There are various ways to deal with this problem, such as adjusting the biasing force of the oscillating arm and using a leaf spring shape so that the first tooth of the missing tooth can be retracted in the radial direction of the missing tooth gear. However, it is easiest and most effective to lower the back of the first tooth of the missing gear. By lowering the back of the first tooth, the force vector acting at the moment when the first gear of the planetary gear and the missing gear meshes becomes a more obtuse angle with respect to the line connecting the shafts of both gears. The effect of preventing jumping is obtained.

<Other embodiments>
The present invention is not limited to the contents described above.

  In the above embodiment, the planetary gear position control mechanism is provided to realize the clutch mechanism that is not affected by the load fluctuation on the driven side, but the load fluctuation on the driven side is small, and the planetary gear is restored during operation. In the case of a driving device in which the torque stably exceeds the biasing force of the swing arm, the planetary gear position control mechanism can be omitted.

  Further, in the above embodiment, the missing gear 2 is provided with only one missing tooth portion, but there may be a plurality of missing tooth portions. By adopting this configuration, it is possible to divide the control operation performed during one rotation of the missing gear, and it is possible to control a plurality of divided operations at an arbitrary timing.

  In the above embodiment, the planetary gear is supported by the swing arm. However, for example, a configuration may be adopted in which the rotation center axis of the planetary gear is regulated and supported so as to be movable by the elongated groove (planetary gear position control mechanism). When using, lift the planetary gear shaft directly with the control lever).

  In addition, in the above embodiment, the toothless gear 2 is fixed to the drive output shaft 11, but the driven gear is supported by another gear that rotatably supports the toothless gear and operates integrally with the toothless gear. The effect is the same even if the drive transmission is transmitted to the other gear train.

  Finally, in the present embodiment, a planetary gear position control mechanism that lifts the swing arm 3 with the control lever 6 is adopted as a method for securing a margin for operation stability. However, a mechanism for controlling the position of the planetary gear is different. There may also be a configuration of

  For example, by providing resistance applying means for bringing the brake member into contact with the planetary gear according to the rotational phase of the toothless gear and applying rotational resistance to the planetary gear during operation, the planetary gear tries to move to the terminal side itself. It is also effective to make the restoring torque to be larger than the urging force of the swing arm. As a similar configuration, the same effect can be obtained even with a brake mechanism that generates resistance between the swing arm and the drive output shaft.

  The field to which the present invention can be applied covers the entire rotary drive system, and contributes to cost reduction and quality improvement of all products.

It is an external view of the mechanical clutch mechanism based on this invention. It is explanatory drawing of the operation standby state of the mechanical clutch mechanism based on this invention. It is explanatory drawing immediately after the operation | movement start of the mechanical clutch mechanism based on this invention. It is explanatory drawing in operation | movement of the mechanical clutch mechanism based on this invention. It is explanatory drawing just before completion | finish of operation | movement of the mechanical clutch mechanism based on this invention. It is a mechanics explanatory view of the mechanical clutch mechanism based on this invention. It is an example of a conventional mechanical clutch mechanism. It is an example of a conventional mechanical clutch mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planetary gear 2 Partial gear 3 Rocking arm 4 Energizing spring 5 Control cam 6 Control lever 10 Idler gear 11 Drive output shaft 12 Solenoid flapper M Motor SL Solenoid

Claims (7)

A toothless gear that is drivingly connected to the driven side and has a toothless region without teeth in at least one location on the outer periphery;
A planetary gear that is movable within a predetermined area in a substantially circumferential direction of the toothless gear, and that can be driven and input to the toothless gear facing the toothless gear;
Drive means for rotationally driving the planetary gear;
Locking means capable of locking the position of the planetary gear,
The planetary gear is biased in one direction by its own weight or biasing means,
The clutch mechanism is characterized in that the locking means can lock the movement of the planetary gear in the urging direction.   The clutch mechanism according to claim 1, further comprising position control means capable of controlling the position of the planetary gear.   2. The clutch mechanism according to claim 1, further comprising resistance applying means capable of applying / releasing rotational resistance to the planetary gear.   The relationship between the missing tooth region of the toothless gear, the movable area of the planetary gear, and the locking position of the planetary gear by the locking means is at least the movable area of the planetary gear regardless of the phase of the missing gear. Somewhere, both the toothless gear and the planetary gear can mesh with each other, and when the toothless gear is in a predetermined phase, from the counter-biasing direction end of the planetary gear movable area. 2. The clutch mechanism according to claim 1, wherein at any position up to the locking position, the two do not mesh with each other.   The clutch mechanism according to claim 1, wherein the restricting means is a solenoid.   6. A powder conveying apparatus using the clutch mechanism according to claim 1 to convey a predetermined amount of powder.   A sheet conveying apparatus capable of conveying a predetermined amount of sheet material by driving a roller using the clutch mechanism according to claim 1.

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