JPH09196152A - Rotation force transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the gear noise caused by the back lash or play of the gear based on the fluctuation of the load applied on a gear train in a rotation transmission device using the gear train. SOLUTION: A rotation transmission device is provided with a gear train GA to transmit the rotation of a drive motor M1 to a feed roller 2a which is a rotary member, a clutch CR2 as a load fluctuating device to fluctuate the load to be transmitted to the gear train GA from the feed roller 2a, and a load adjusting device T1 to keep the load on gears G5-G8 arranged on the end side of the gear train GA constantly above the prescribed value according to the fluctuation of the load of the gear train GA by the clutch CR2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational force transmission device for transmitting a rotational force of a drive motor to a rotary operating member by using a gear train, and more particularly, a load transmitted from the rotary operating member to an output gear is changed. The present invention relates to a rotational force transmission device having a load variation device.

[0002]

2. Description of the Related Art Conventionally, gear noise has been a problem in a torque transmission device using a gear train. As a gear noise countermeasure, a method of applying a lubricant to the gear surface, a method of forming a tooth profile with a helical gear, and the like are generally adopted. The following techniques (J01) and (J02) are known as methods other than the general method for the noise countermeasure of the torque transmitting device. (J01) Japanese Unexamined Patent Publication No. 4-27961 This publication describes an image carrier for image exposure driven by a single common drive source through a rotational force transmission device and various types for image formation. In an image forming apparatus having a rotating member, a technique for preventing deterioration of an image due to the vibration of the image carrier due to the vibration of the rotating member by adopting an elastic material gear as a gear of the image carrier that meshes with the rotational force transmission device is described. However, this is accompanied by the problems of increased cost and reduced transmission efficiency.

(J02) Technology disclosed in Japanese Patent Laid-Open No. 55-45081 In this publication, in order to prevent the occurrence of vibration and noise in the moving direction due to the abrupt start of the reciprocating member, the driving force at the start of the moving However, this method has a problem that the required working time becomes long and the working efficiency is lowered.

(J03) Technology disclosed in Japanese Utility Model Laid-Open No. 63-165956 In this publication, a plurality of rotating members driven by a single drive source via a rotational force transmitting device (gear) and requiring forward / reverse switching. In an image forming apparatus or the like having a structure, a technique for constantly applying a light braking force to gears to prevent noise caused by backlash of a rotational force transmission device (gear) that occurs when switching the forward and reverse rotations of the plurality of rotating members is provided. Stated.
In this method, an extra load is always applied, which may cause step-out of the step motor due to an increase in load, and it is necessary to increase the capacity of the motor, resulting in an increase in noise of the motor itself.

In view of the above circumstances and examination results, the present invention has an object to be described in (O01) below. (O01) To reduce gear noise caused by backlash and rattling of gears due to fluctuations in load applied to the gear train in a torque transmission device using the gear train.

[0006]

The present invention devised to solve the above problems will now be described. The elements of the present invention are to facilitate correspondence with the elements of the embodiments described later. , The elements of the embodiments are enclosed in parentheses (when there are a plurality of elements of the corresponding embodiments, they are also described together). In addition,
The reason why the present invention is described in correspondence with the reference numerals of the embodiments described below is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(1st invention) In order to solve the aforementioned problem,
The torque transmission device of the first invention of the present application has the following requirements (Y01) drive motor (M1; M)
Gear trains (GA; GB) and (Y02) for transmitting the rotational force of 2) to the rotation operating member (2a; 72a), the rotation operating member (2)
a; 72a) load change devices (CR2; CR5) for changing the load transmitted to the gear train (GA; GB), (Y0
3) The gear train (GA; GB;) in accordance with the load fluctuation of the gear train (GA; GB) by the load fluctuation device (CR2; CR5).
Gears (G5 to G8; G12 to G1) arranged on the terminal side of GB)
A load adjustment device that constantly maintains the load of 4) above a specified value.

(2nd invention) Further, the rotational force transmitting apparatus of the second invention of the present application is characterized in that, in the rotational force transmitting apparatus of said 1st invention, the following requirements are satisfied: (Y04) copy The rotation actuating member (2a; 72a) constituted by a feed roller (2a; 72a) that conveys the paper taken out by the take-out roller (1; 78) from the paper feed tray (36-40) of the machine (F), (Y05) The shaft of the feed roller (2a; 72a) and the gear (G8;
G14), the load fluctuation device (CR2; CR5) constituted by a clutch (CR2; CR5) provided between
(Y06) The end gear (G8; G1) of the gear train (GA; GB) rotated by the rotational force of the drive motor (M1; M2)
4) Rotating force of the terminal side rotating member (1, 2a, 3)
a, G9 to G11; 71, 72a, 72b, 78, G16 to G2
4) and a rotary braking device (T1; T2) that applies a rotary braking force to any of the gears (G5 to G8; G12 to G14) arranged on the terminal side of the gear train (GA; GB), and the clutch. From the feed roller (2a; 72a) generated by turning on and off (CR2; CR5), the gear train (GA;
The gears (G5 to G8; G) arranged on the terminal side of the gear train (GA; GB) according to the fluctuation of the load transmitted to GB).
12 to G14) and a load control device configured to control the operation of the rotary braking device (T1; T2) so as to always keep the load above a predetermined value.

(Supplementary explanation of means for solving the problem)
The "gear (G5 to G8; G12 to G14) arranged on the terminal side of the gear train (GA; GB)" is a gear train (GA; GB) from the viewpoint of noise suppression effect of the entire gear train (GA; GB). Of all the gears included in GB), the gears except for half the gears close to the drive motor (that is, half the gears closest to the gear arranged at the farthest end from the drive motor) are meant.

[0010]

Next, the operation of the present invention having the above features will be described. (Operation of the first invention) The rotational force of the drive motor (M1; M2) is applied to the rotation operating member (2a;
72a). The load acting on the rotary operation member (2a; 72a) is transmitted to the gear train (GA; GB). The load changing device (CR2; CR5) changes the load transmitted from the rotation operating member (2a; 72a) to the gear train (GA; GB). This load fluctuation device (CR2; C
When the load transmitted from the rotary actuating member (2a; 72a) to the gear train (GA; GB) by R5) changes, for example, suddenly changes to a no-load state, the drive motor (M1;
Backlash may occur between the gears from M2) to the output gears (G7; G13), which may adversely affect noise and vibration. The load adjusting device is the load changing device (CR
2; CR5), the load of the gears (G5 to G8; G12 to G14) arranged at the end side of the gear train (GA; GB) is always set to a predetermined value in accordance with the variation of the load of the gear train (GA; GB). Keep above. As described above, when the gears (G5 to G8; G12 to G14) arranged on the terminal side of the gear train (GA; GB) are constantly subjected to a load of a predetermined value or more, the gears are arranged on the terminal side on which the load acts. Than the gears (G5 to G8; G12 to G14)
The gears arranged on the drive motor (M1; M2) side are always subjected to a load of a predetermined value or more. In a gear to which a load equal to or more than the predetermined value acts, noise due to backlash or the like is eliminated.

(Operation of Second Invention) Rotational actuating member (2a;
72a) is composed of a feed roller, and the paper taken out by the take-out roller (1; 78) from the paper feed tray (36-40) of the copying machine (F) is taken by the feed roller (2a; 72a). Be transported. The load changing device (CR2; CR5) is provided with the feed roller (2a;
72a) and a gear (G8; G14) mounted on the shaft of the clutch (CR2; CR5). That is, the feed roller (2a; 72a)
The sheet is intermittently conveyed by means of the clutch (C
R2; CR5) is turned on and off at predetermined time intervals. When the clutch (CR2; CR5) is switched from on to off, noise may occur due to backlash of the gears of the gear train (GA; GB).

The braking control device of the load adjusting device includes a gear train (G) from the feed roller (2a; 72a) generated by turning on and off the clutch (CR2; CR5).
The operation of the rotary braking device (T1; T2) is controlled according to the fluctuation of the load transmitted to A; GB). The rotary braking device (T1; T2) is a terminal side to which the torque of a gear (G8; G14) at the end of the gear train (GA; GB) that is rotated by the torque of the drive motor (M1; M2) is transmitted. Rotating members (1, 2a, 3a, G9 to G11; 71, 72a, 72b, 7
8, G16 to G24) and any of the gears (G5 to G8; G12 to G14) arranged on the terminal side of the gear train (GA; GB) are subjected to rotational braking force. At this time, the gears (G5 to G8; G) arranged on the terminal side of the gear train (GA; GB)
The load of 12 to G14) is always kept above a predetermined value. In this case, the gear (G
5 ~ G8; G12 ~ G14) than the drive motor (M1; M2)
A load of a predetermined value or more always acts on the gear arranged on the side. In a gear to which a load equal to or more than the predetermined value acts, noise due to backlash or the like is eliminated.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An example (that is, an example) of an embodiment of the present invention will be described below with reference to the drawings.
The present invention is not limited to the following examples. In order to facilitate understanding of the following description, the orthogonal coordinate axis X in the directions of arrows X, Y, Z orthogonal to each other in the drawings.
The axes, Y-axis, and Z-axis are defined, and the arrow X direction is the front, the arrow Y direction is the left, and the arrow Z direction is the up. In this case, the direction opposite to the X direction (front) (-X direction) is the rear, the direction opposite to the Y direction (left) is the right (-Y direction), and the direction opposite to the Z direction (upper) (-Z direction). Is below. Also, forward (X direction)
And including the back (-X direction) is referred to as the front-back direction or the X-axis direction, including the left (Y direction) and the right (-Y direction) is referred to as the left-right direction or the Y-axis direction, and upward (Z direction) And the lower side (-Z direction) are also referred to as the vertical direction or the Z-axis direction. Furthermore, in the figure, the ones with "・" in the "○" mean the arrows from the back of the paper to the front, and the ones with "X" in the "○" are from the front of the paper. It means an arrow pointing to the back.

(Embodiment) Next, Embodiments 1 and 2 of the torque transmission device of the present invention will be described with reference to FIGS. FIG. 1 is an overall explanatory view of a copying machine F having an automatic document feeder B incorporating a first embodiment of a torque transmission device of the present invention and a copying machine main body A incorporating a second embodiment. FIG. 2 is a plan view of the rotational force transmitting device according to the first embodiment incorporated in the document taking-out portion of the automatic document feeder. FIG.
FIG. 3 is a front cross-sectional explanatory view of a transmission mechanism of the rotational force transmission device of FIG. 2. FIG. 4 is an explanatory view of a paper feeding unit in which the second embodiment is incorporated, and is an enlarged view of a main part of FIG. FIG. 5 is a perspective view of a paper feeding unit in which the second embodiment is incorporated. FIG.
FIG. 8 is a perspective view of a main portion of a second embodiment of the torque transmission device incorporated in the paper feeding unit of FIG. 4, showing a pressing mechanism of a retard roller against a feed roller and the like. FIG. 7 is an explanatory diagram of the transmission mechanism of the second embodiment. FIG. 8 is an explanatory view of the arrangement of the rotation braking device clutch on the feed roller according to the second embodiment, and is a plan view of relevant parts of FIG. 6. FIG. 9 shows the second embodiment.
FIG. 3 is an explanatory view of a support structure of the retard roller of FIG.

In FIG. 1, a copying machine F is composed of a copying machine main body A having a platen glass A1 at its upper end, and an automatic document feeder B which is rotatably supported on the upper surface of the copying machine main body A. The automatic document feeder B includes a document feed tray TRk on which documents Ki of various sizes to be copied are stacked and placed, and a document discharge tray TRh on which the copied document Ki is discharged. The document discharge tray TRh includes a tray body and an auxiliary tray supported so that it can be extended to the position indicated by the chain double-dashed line in FIG. 1 when a large document Ki is stored at the tip of the tray body. .

The automatic document feeder B detects a document presence / absence sensor S1 for detecting the presence / absence of a document Ki placed on the document feed tray TRk and a plurality of documents Ki placed on the document feed tray TRk. It has a document take-out roller 1 which takes out from the upper side and conveys it to the downstream side in the conveying direction. Further, the automatic document feeder B is a separation roller device 2 that separates the documents extracted from the document extraction roller 1 one by one and conveys the documents to the downstream side, and a takeaway roller sequentially arranged on the downstream side of the separation roller device 2. 3, a document registration roller 4, a transport belt device 6, a discharge side transport roller 7, a discharge roller 8 and the like. In FIGS. 1 and 3, the take-out roller 1 is
The document Ki is rotated while frictionally contacting the document Ki by the pressing force of gravity, and the document Ki is taken out from the document feed tray TRh. The separation roller device 2 includes a drive motor M.
1 (see FIG. 2) is composed of a feed roller 2a as a rotary operation member to which a rotational force is transmitted, and a non-rotatable retard roller 2b contacting the feed roller 2a. The takeaway roller 3 is a drive roller 3a and a driven roller. It is composed of 3b. Further, the document registration roller 4, the conveyor belt device 6, the ejection side conveyor roller 7, the ejection roller 8 and the like are composed of a driving roller and a driven roller, respectively. Then, the original document Ki taken out from the original document feeding tray TRk is transferred to the platen glass A1.
After being copied in a state of being stopped at the above predetermined copying position, it is conveyed to the downstream side and discharged to the document discharge tray TRh.

2 and 3, the drive motor M1
Is constituted by a step motor and is supported by the rear frame Fr (see FIG. 2) of the automatic document feeder B. The rotational force transmission device for transmitting the rotational force from the drive motor M1 to the feed roller 2a as a rotary operation member is a drive motor shaft mounting gear G1 mounted on the output shaft of the drive motor M1 and the gear G1 in order. It has gears G2 to G11 which mesh with each other and transmit the rotational force. A clutch CR1 is provided between the shaft of the take-out roller 1 and the gear (take-out roller shaft mounting gear) G10 mounted on the shaft, and the shaft of the feed roller 2a and the gear mounted on the shaft. A clutch CR2 is provided between the gear (feed roller shaft mounting gear) G8. The gears G10 and G8 can freely rotate on their shafts when the clutches CR1 and CR2 are off, respectively, but can rotate integrally with these shafts when the clutches CR1 and CR2 are on.

The gears (G1 to G8) of the gear train GA composed of the gears G1 to G8 have a function of transmitting the rotational force of the drive motor M1 to the feed roller 2a as the rotary operation member. . The gear G7 on the terminal side of the plurality of gears (G1 to G8) forming the gear train GA is supported by its shaft via a clutch CR3, and freely rotates when the clutch CR3 is off, but the clutch CR3. When is on, it is configured to rotate integrally with the shaft. Further, the gear G11 is supported on the shaft of the drive roller 3a of the takeaway roller 3 via the clutch CR4, and freely rotates when the clutch CR4 is off, but is integrated with the shaft when the clutch CR4 is on. It is configured to rotate. That is, when the clutch CR4 is off, the drive roller 3a of the takeaway roller 3 is stopped.

Of the drive rollers 3a of the take-out roller 1, the feed roller 2a, and the take-away roller 3 which take out and convey the original document Ki by receiving the rotational force transmitted from the drive motor M1, the feed roller 2a is the feed roller 2a. ,
Since the document Ki is conveyed while contacting the non-rotatable retard roller 2b, the load during operation is the largest. Therefore, when the clutch CR2 arranged between the feed roller shaft and the gear (feed roller shaft mounting gear) G8 mounted on the feed roller shaft is ON and OFF, the gears of the gear train GA from the feed roller 2a ( The load transmitted to G1 to G8) fluctuates greatly.

The load of the drive roller 3a of the takeaway roller 3 when the clutch CR4 is on and the load of the take-out roller 1 when the clutch CR1 is on are also transmitted to the gear train GA. However, their transmission load is small, and the variation of the transmission load is smaller than that of the feed roller 2a. Therefore, noise generated in the gears (G1 to G8) of the gear train GA when the load transmitted from the take-out roller 1 and the drive roller 3a of the takeaway roller 3 to the gear train GA is reduced from the feed roller 2a. When the load transmitted to the gear train GA is reduced, there is no problem compared to the magnitude of noise generated in the gears (G1 to G8) of the gear train GA. That is, the influence of the load fluctuation due to the ON / OFF of the feed roller 2a in the clutch CR2 is greater than the influence of the clutch CR1 of the take-out roller 1 and the clutch CR4 of the takeaway roller 3 in the gear train GA (G1 to G8). Dominates the generation of noise in. Therefore, in the first embodiment, the gears on the terminal side of the gears (G1 to G8) forming the gear train GA according to the fluctuation of the load transmitted from the feed roller (rotational operation member) 2a to the gear train GA. Braking force is being applied to G7. That is, the braking force is applied to the gear G7 according to the on / off state of the clutch CR2. Therefore, in the first embodiment, the clutch CR2
Corresponds to the load variation device of the present invention.

The gear G7 is supported on its shaft via a clutch CR3. That is, when the clutch CR3 is off, the gear G7 can freely rotate about its shaft G7a, and when the clutch CR3 is on, the gear G7 rotates integrally with its shaft G7a. A braking plate P1 is fixed to the shaft G7a. The braking plate P1 is pressed by the friction braking member P2 fixed to the frame F. Therefore, the clutch CR3 is turned on,
When the rotation of the gear G7 is transmitted to the shaft G7a and the braking plate P1, the friction contact between the braking plate P1 and the friction braking member P2 causes
A braking force acts on the gear G7. Therefore, the braking plate P1 and the friction braking member P2
Thus, a brake BR1 that applies a rotational braking force to the gear G7 arranged at the end of the gear train GA that is rotated by the rotational force of the drive motor M1 is configured.

The clutch CR3 is connected at the timing opposite to the occurrence of load fluctuation (for example, instantaneous loss of load) when the clutch CR2 is switched from ON to OFF, and the rotational braking force by the brake BR1 is rotated by the gear G7. Act on the shaft,
The load applied to the gear G7 and the gears G1 to G6 connected to the drive source side of the gear G7 is constantly maintained at a constant value equal to or higher than a predetermined value. Therefore, the rotation braking device T1 is configured to constantly maintain the load acting on the terminal gear G7 of the gear train GA at a predetermined value or more by the clutch CR3 and the brake BR1. Further, by the rotary braking device T1 and the braking control device for controlling the operation of the rotary braking device T1, a load adjusting device for constantly maintaining the load of the gear G7 arranged at the end side of the gear train GA at a predetermined value or more. Is configured.

The brake BR1 is connected to the gear G7.
Instead of being provided on the shaft G7a, it may be provided on any shaft of the gears G6 to G10. And the braking device BR
It is possible to always apply a load of a predetermined value or more to the gear arranged on the drive motor M1 side of the gear provided with 1. It is possible to prevent the generation of noise due to backlash, backlash, etc., for the gear to which a load that is constantly above a predetermined value acts. Therefore, the brake B
R1 is more effective in preventing noise as it is provided in a gear farther from the drive motor M1.

Next, the copying machine main body A will be described. In FIG. 1, a document illumination unit 11 that scans while illuminating a document on the platen glass A1 is arranged below the platen glass A1. Original lighting unit 1
Reference numeral 1 has a document illumination light source 12 and a first mirror 13. A mirror unit 14 is arranged below the platen glass A1.
Is configured to move at a speed half of the moving speed of the document illumination unit 11 in order to make the optical path length of the document reflected light to the image forming position constant. Mirror unit 1
4 is emitted from the illumination light source and reflected by the original document Ki,
It has a second mirror 16 and a third mirror 17 that reflect the original image light reflected by the first mirror 13. The original image light reflected by the third mirror 17 forms an image forming lens 18
Through the fixed mirrors 19, 21, and 22, and an image is formed on the surface of the drum-shaped image carrier 23. An IIT (image input terminal) is constructed from the elements indicated by the reference numerals 11 to 23.

Next, the IOT (image output terminal) arranged below the image input terminal IIT will be described with reference to FIGS. 1 and 2. The image carrier (photosensitive drum) 23 is arranged so that an electrostatic latent image is formed on the surface thereof by the original image light imaged at the latent image writing position Q1 while being rotationally driven.
A charging charger 24 that uniformly charges the surface of the image carrier 23 is arranged around the image carrier 23.
A red developing unit 26 and a black developing unit 2 that sequentially develop the electrostatic latent image into a toner image are provided downstream of the latent image writing position Q1 along the surface of the image carrier 23.
7, a transfer unit 28 for transferring the toner image on the image carrier 23 to the sheet at the transfer position Q2, a cleaner unit 29 for scraping off the toner remaining on the image carrier 23 without being transferred to the sheet, and the like. ing. As described above, the copying machine F shown in FIG. 1 has developing units 26 and 27 for two colors, but it is possible to provide developing units for one color or four colors. Further, in FIG. 1, on the left side of the transfer position Q2, a fixing device 31 for heating and fixing the toner image transferred onto the sheet is arranged. An unfixed paper transport path 32 for transporting the paper on which the unfixed toner image is transferred is provided between the transfer position Q2 and the fixing device 31.

Further, the IOT has a sheet supply device H, and the sheet supply device H includes a plurality of sheet feed trays 36 to 40 corresponding to the type of sheet and a reversing tray 42 used for double-sided copying. , The paper sent from each of the trays 36 to 40 is transferred to the transfer position (the transfer device 28).
Between the image carrier 23 and the image carrier 23). A plurality of paper transport rollers R are arranged in the paper carry-in path 43. In FIG. 4, the paper carrying roller R is composed of a driving roller R1 and a driven roller R2.

In FIG. 1, the reversing conveyance path 4 for reversing the sheet on which the toner image is fixed (that is, the fixing sheet) and then conveying it to the reversing tray 42 in the fixing device 31.
4 and the paper discharge path 46 are connected. A switching gate 47 is provided at a branch portion of the reverse conveyance path 44 and the paper discharge path 46. At the end of the paper discharge path 46, a discharge roller 48 for discharging the paper to the discharge tray 49 is arranged.

As shown in FIG. 1, each of the paper feed trays 3
A sheet placement plate 53 on which a sheet is placed is housed on the upper surface of the bottom plate 52 of 6 to 40. The paper loading plate 53 has a left end rotatably supported on the inner bottom surface of each of the paper feed trays 36 to 40. Further, when the sheet placed on the sheet placing plate 53 is sent out, both side ends along the conveying direction of the sheet are configured to be guided by the sheet side end positioning member 54.

In FIGS. 1 and 4, the paper feed trays 36 to
A front end (right end in the figure) of the sheet 40 in the sheet conveying direction is supported by a sheet front end support wall 56. A lever through hole 57 is formed in the lower portion of the paper front end support wall 56,
A rotary shaft 58 for raising the paper is arranged on the outer side thereof.
One end of an L-shaped paper lifting lever 59 is fixed to the paper lifting rotary shaft 58, and the other end thereof penetrates the lever through hole 57 and slidably contacts the lower surface of the paper loading plate 53. Touching. Rotating shaft 5 for raising the paper
Reference numeral 8 is for holding the upper end position of the paper at an appropriate position when rotated by a drive motor M2 of a paper feeding unit (paper feeding unit) U1 described later through a reverse rotation transmitting one-way clutch in FIG. It is configured.

To the right of each of the paper feed trays 36-40,
A sheet feeding unit U1 as a sheet feeding device is arranged.
The paper feeding unit U1 is fixedly supported by a body frame (not shown) of the copying machine F. In FIG. 5, the sheet feeding unit U1 has a unit frame 61. The unit frame 61 includes a front frame 62, a frame-shaped rear frame 63, and a connecting frame 64 connecting them.
Etc. A supporter (support member) 66 is supported on the connection frame 64. The frame-shaped rear frame 63 is arranged on the outer side (rear side) of the side surface (rear side surface, that is, the side surface on the −X side) of each of the paper feed trays 36 to 40 and the reversal tray 42 along the paper transport direction. .

In FIG. 5, the frame-shaped rear frame 6 is shown.
3 is a drive motor M composed of a step motor
2. Solenoid SL etc. are supported. Further, as shown in FIG. 7, the rear frame 63 includes a plurality of gears Gb rotatably driven by the drive motor M2, gears G12 to G14 rotatably driven via the plurality of gears Gb, and the like. The gear train GB to be supported is supported.
That is, the gear train GB is composed of a plurality of gears Gb and gears G12 to G14.

The rear frame 63 and the supporter 66
The feed roller shaft 71 is rotatably supported by (see FIG. 5), and a feed roller 72a serving as a rotation operating member is fixed to the feed roller shaft 71. The feed roller 72a and a retard roller 7 described later
A separating roller device 72 is constituted by 2b. The feed roller shaft 71 is rotationally driven by the drive motor M2 via the plurality of gears (the plurality of gears shown in FIG. 7 arranged between the drive motor M2 and the gear G12) Gb and gears G12 to G14. Is configured. In FIG. 8, the gear G14 is supported via a clutch CR5 on a feed roller shaft 71 that rotates integrally with the feed roller 72a, and is freely rotatable on the feed roller shaft 71 when the clutch CR5 is off. , Is turned on, the feed roller shaft 71 is integrally rotated. Therefore, when the clutch CR5 is on, the load acting on the feed roller 72a is the load roller shaft 71, the clutch CR5, the gear G14, the gears G13 and G12, and the plurality of gears (the gear G12 and the drive motor M2). Is transmitted to a plurality of gears Gb provided between. However, when the clutch CR5 is off, the load acting on the feed roller shaft 71 is
The gears G14, G13, G12 and the plurality of gears Gb
(See FIG. 7).

Therefore, the clutch CR5 is connected to the gear G1 from the feed roller 72a as a rotary operation member.
It has a function as a load changing device for changing the load transmitted to the gear train GB constituted by 4, G13, G12 and the plurality of gears Gb (see FIG. 7). That is,
The clutch CR5 is the load fluctuation device CR5 in the second embodiment of the torque transmission device of the present invention. Also, the gear G13
Is supported on the rotatable shaft G13a via a clutch CR6, and is freely rotatable on the shaft G13a when the clutch CR6 is off, and rotates integrally with the shaft G13a when the clutch CR6 is on. Has become.

A braking plate P3 is fixed to the rotatable shaft G13a of the gear G13, and the braking plate P3 is mounted on the rear frame 63.
It is in frictional contact with the friction braking member P4 fixed to the. A brake BR2 is constituted by the braking plate P3 and the friction braking member P4 on the shaft G13a. Further, the drive motor M2 is controlled by the brake BR2 and the clutch CR5.
A rotary braking device T2 that applies a rotary braking force to a gear G13 arranged on the terminal side of the gear train GB (see FIGS. 7 and 8) between the feed roller shaft 71 and the feed roller shaft 71 is configured. In the control device for controlling the operation of the rotation braking device T2, the clutch (load fluctuation device) CR5 is turned off, and the load acting on the feed roller (rotation operation) 72a is the gear G1.
When the transmission to the gear train GB composed of 4 to G12 and the plurality of gears Gb is stopped, the rotation braking device T2 is operated to constantly apply the load of the gear G13 arranged at the end side of the gear train GB. Hold above a predetermined value. The rotational braking device T2 and its control device constitute a load adjusting device of the second embodiment of the rotational force transmitting device of the present invention.

5 and 6, a swing arm 73 is rotatably supported on the feed roller shaft 71.
The swing arm 73 has a flat top plate and a side plate bent downward from its side end. And
The swing arm 73 receives a force of rotating downward due to the action of gravity and a weak spring (not shown), but the lower surface of the rear end (−X side end) of the swing arm 73 moves downward. It is supported by an elevating lever 74 as an arm position control member for controlling the rotation to the. The elevating lever 74 is fixed to an arm elevating shaft 75 extending in the front-rear direction. In FIG. 6, the arm lifting shaft 75 has a rear end (-X side end).
Are rotatably supported by the rear frame 63 (see FIG. 5).

A lever (not shown) that is connected to a telescopic rod (not shown) of the solenoid SL is fixed to the rear end (-X side end) of the arm lifting shaft 75,
The solenoid SL is expanded and contracted so that it is rotated around the axis by a constant angle. As can be seen from FIG. 6, the arm lifting shaft 75 rotates about its axis,
When the solenoid SL is off, the lifting lever 74 is held in the raised position, and when the solenoid SL is turned on, the lifting lever 74 is held in the lowered position.
When the lifting lever 74 is held in the lowered position, the swing arm 73 swings downward due to gravity and a spring (not shown).

4 and 5, the swing arm 73 is provided with a position control protruding piece 73a extending leftward (Y direction). The position control protruding piece 73a moves up and down according to the swing of the swing arm 73. A swing arm attitude sensor S as a pickup roller position sensor including a light emitting element Sa and a light receiving element Sb at a position sandwiching the movement path of the position control protruding piece 73a from the front-rear direction (X axis direction).
Is arranged. When the swinging posture of the swinging arm 73 drops below a predetermined position, the position control projection 7
3a is moved downward between the light emitting element Sa and the light receiving element Sb, and the swing arm attitude sensor S is turned from OFF to ON. The swing arm attitude sensor S is arranged corresponding to each of the paper feed trays 36-40.

A take-out roller shaft 77 extending forward (in the X direction) is rotatably supported at the left end (tip) of the swing arm 73. A pair of front and rear take-out rollers 78 and a gear G15 are fixed to the take-out roller shaft 77. The swing arm posture sensor S for detecting the paper height is turned off when the take-out roller 78 is above the paper take-out position, which is set slightly below the raised position, and is lowered below the paper take-out position. It is configured to be turned on at times. Therefore, the sheet is fed out when the swing arm posture sensor S is OFF, and when it is ON, the sheet is lifted until it is OFF. The gear G15 is a gear (feed roller shaft mounting gear) G19 fixed to the feed roller shaft 71 via gears G16 to G18 (see FIGS. 5 and 6) rotatably mounted on the swing arm 73. It is in mesh. Therefore, when the feed roller shaft 71 rotates, the feed roller 72a and the gear G19 fixed to the feed roller shaft 71 rotate, and at the same time, the gear G19 and the gear G19.
The gear G15 rotates via 18 to G16. When the gear G15 rotates, the take-out roller shaft 77 and the take-out roller 78 rotate.

4 and 6, the feed roller 7 is
The unit frame 61 is provided below 2a (see FIG. 5).
A rocking support member 82 (see FIGS. 6 and 9) that is rockable around a rocking shaft 81 that is fixedly supported by is disposed. On the retard roller shaft 83 fixed to the swing support member 82 (see FIGS. 6 and 9), the hub 8 formed integrally with the gear G21 is provided.
4 (see FIG. 9) is rotatably supported. A retard roller 72b is fixed on the hub 84 of the gear G21. Therefore, the retard roller 72b and the gear G21 can rotate integrally on the retard roller shaft 83. In FIG. 5, the swing support member 82
A rotational force is applied around the swing shaft 81 by a tension spring 86 (see FIG. 6) whose one end is connected to the connection frame 64. The retard roller 72b is pressed against the feed roller 72a by the action of the tension spring 86.

A torque limiter 87 is attached to the swing shaft 81 supported by the connecting frame 64 so as not to rotate. In FIG. 8, the torque limiter 87 is shown.
Is an output hub 87a fixed to the non-rotatable swing shaft 81, an input hub 87b arranged around the output hub 87a, and an input hub 87b.
And a magnetic powder 87d housed between the magnet 87c and the output hub 87a. The gear G21 meshes with a gear G24 that rotates integrally with the input hub 87b via gears G22 and G23 supported by the swing support member 82.

When the rotational force of the retard roller 72b driven by the feed roller 72a is transmitted to the input hub 87b of the torque limiter 87 via the gears G21, G22, G23, the output hub 87a cannot rotate. The input hub 87b runs idle. At that time, since the magnetic powder 87d between the input hub 87b and the output hub 87a moves while frictionally contacting each other,
Braking force acts on the input hub 87b. This braking force is applied to the retard roller 72b via the gears G24 to G21.
Is transmitted to the feed roller 72a that contacts the retard roller 72b.

(Operation of Embodiment) Next, the operation of Embodiment 1 of the present invention (the embodiment of the torque transmission device incorporated in the automatic document feeder B) will be described. FIG.
2 is a diagram showing a state in which the load and noise generated in the gear train GA change when the load transmitted from the feed roller 2a of the first embodiment to the gear train GA in FIG. 2 is turned on and off by the clutch CR2. FIG. 10A is a diagram showing a state in which the load adjusting device is not used, and FIG.
[Fig. 3] is a diagram showing a state in which a load adjusting device is used.

2 and 3, when copying is started by an operation command from the user interface of the copying machine main body A, the drive motor M1 rotates counterclockwise as shown in the example of FIG. The rotational force is the same as that of the gears G1 to G11 shown in FIGS.
Is transmitted to the drive roller 3a of the takeaway roller 3, the feed roller 2a, the take-out roller 1 and the like. The document K is fed from the document feed tray TRk by the take-out roller 1 and the feed roller 2a.
When i is taken out and conveyed, the clutch CR1 of the take-out roller 1, the clutch CR2 of the feed roller 2a, the clutch CR4 of the drive roller 3a of the takeaway roller 3 are taken.
And the clutch C of the rotary braking device T1
Turn off R3. When the clutch CR3 is off, the gear G7 is free to rotate on its axis G7a and the axis G7a does not rotate. Further, since the clutches CR1 and CR2 are turned on, the take-out roller 1 and the feed roller 2a as a rotation actuating member rotate to take out and convey the document. The clutches CR1, CR2 and CR4 are turned on and off at predetermined timings (original take-out, conveyance or stop timing).

When the clutches CR1 and CR2 are on, the feed roller 2a is a non-rotatable retard roller 2b.
Since it rotates while being pressed by the feed roller 2a
A load (braking force) is acting on. When the originals Ki are taken out in an overlapping manner, the lower originals Ki are stopped by the friction braking force of the retard roller 2b, and the originals Ki are separated one by one and conveyed to the takeaway roller 3. The document is taken out and conveyed by the take-out roller 1 and the feed roller 2a intermittently. Therefore, the feed roller 2
Timing charts of the operation of a are as shown in FIGS. 10A and 10B.

In FIGS. 10A and 10B, a load acts on the feed roller 2a while the feed roller (rotation actuating member) 2a is rotating (while the clutch CR2 is on), and this load acts as a braking force on the feed roller ( It is transmitted from the rotation operating member) 2a to the gear train GA. If the rotary braking device T1 composed of the brake BR1 and the clutch CR3 does not operate, as shown in FIG. 10A, while the clutch CR2 as the load changing device is off, backlash of the gears G1 to G8 and Noise and vibration occur due to rattling. However, in the first embodiment of the torque transmission device of the present invention, the load acting on the gear train GA due to the operation of the rotary braking device T1 is activated while the clutch CR2 as the load changing device is off. As shown in FIG. Therefore, the gear train G
It is possible to prevent noise and vibration caused by backlash and rattling of the A gears G1 to G8.

Next, a second embodiment of the torque transmission device of the present invention
The operation of the embodiment of the rotational force transmission device incorporated in the paper feeding unit U1 of the copying machine main body A will be described. Copier F
When copying is started in accordance with the operation of the user interface (not shown), as shown in FIGS. 5 and 6, the sheet feeding unit U1 corresponding to the sheet feeding trays 36 to 40 in which sheets of a predetermined size are stored is driven. The motor M2 is normally rotated, the solenoid SL is turned on, and the take-out roller 78, which is normally held at the take-out roller rising position, is in a lowered position (sheet take-out position) where it can contact the paper on the upper surfaces of the paper feed trays 36 to 40. Get off at. In the meantime, the paper raising rotary shaft 58 and the paper placing plate 53, which are connected to the drive motor M2 via the reverse rotation transmitting one-way clutch (not shown), are stopped.

In this state, the feed roller 72a and the take-out roller 78 intermittently receive the forward rotation force of the drive motor M2 by turning on and off the clutch CR4 as a load changing device, and each time one sheet is fed. The operation of rotation and stop is repeated. During that time, the take-out roller 78 is moved up and down for each sheet feeding by turning on / off the solenoid SL (see FIG. 5) which is synchronized with this rotation and stop, and is brought into contact with or separated from the uppermost sheet in the sheet feeding trays 36-40. repeat. That is, the solenoid SL is energized for each sheet, and the lever connected to the telescopic rod (not shown) of the solenoid SL is attracted to the arm lifting shaft 75.
Rotates, the swing arm 73 becomes free, and the take-out roller 78 rotates and descends to the top sheet.

The take-out roller 78 receives the rotational force of the drive motor M2 transmitted to the feed roller 72a via the connected gears G18 to G16, and contacts the uppermost sheet with a proper pressure in the sheet feeding direction. The uppermost sheet is rotated and sequentially fed toward the nip portion of the feed roller 72a and the retard roller 72b (see FIG. 6). The retard roller 72b is rotated by being dragged by the movement of the sheet that has entered the feed roller 72a or the nip portion, and the rotational force thereof is the gear G.
Input hub 87b of the torque limiter 87 via 23-G20
Is transmitted to This transmitted torque is input to the input hub 87.
Rotational energy is absorbed by an appropriate frictional resistance between the cylindrical magnet 87c in the b and the magnetic powder 87d which is a fine particle made of metal, and a certain limit of rotational torque is transmitted to the output hub 87b, and the non-rotatable rocking. It is absorbed by deformation of the shaft 81 and the like. The rotation torque is the retard roller 7
Excess torque that acts on 2b as a rotational braking force, but is still not absorbed, is released in the idle state of the input hub 87a.

Therefore, when two sheets of paper are fed into the nip portion, an appropriate rotational braking force acts on the retard roller 72b which is rotated by the feed roller 72a, so that the lower sheet of paper is affected by the rotation braking force. It stops at the position where the leading edge has passed the nip portion to some extent, and only the upper sheet is conveyed. The sheet thus separated into one sheet is further transported to the downstream side, and further transported to the downstream side (upper side) by the plurality of sheet transport rollers R arranged along the sheet transport path 43, and is transferred to the transfer position. It is transported to Q2 (see Fig. 1). In this way, copying is performed while feeding paper.
When a plurality of sheets are fed and the position of the upper surface of the sheet is lowered and the swing arm posture sensor S is turned on, the drive motor M2 is rotated in the reverse direction by a certain amount to rotate the sheet raising rotary shaft 58. When it is rotated, the sheet raising lever 59 fixed to it is lifted to lift the sheet placing plate 53 and the sheet therein, and the take-out roller 78 is pushed up to the sheet. As a result, when the swing arm posture sensor S is turned off, the reverse rotation of the drive motor M2 is stopped, and the sheet is taken out at that position.

The paper is taken out and conveyed by the take-out roller 78 and the feed roller 72a intermittently.
Therefore, the timing chart of the operation of the feed roller 72a is as shown in FIGS. 10A and 10B. FIG.
0A and FIG. 10B, a load acts on the feed roller 72a while the feed roller (rotational operation member) 72a is rotating (while the clutch CR5 is on), and this load acts as a braking force on the feed roller (rotational operation member). 72a to the gear train GB (gears G14 to G12 and the plurality of gears Gb, etc.).

If the rotary braking device T2 composed of the brake BR2 and the clutch CR6 does not operate, as shown in FIG. 10A, while the clutch CR5 as the load changing device is off, the gear train GB is turned on. Noise and vibration occur due to backlash and rattling of the constituent gears G14 to G12, Gb. However, in the second embodiment of the torque transmission device of the present invention, while the clutch CR5 serving as the load varying device is off, the load acting on the gear train GB due to the operation of the rotary braking device T2 is as shown in FIG. 10B. As shown in FIG. Therefore, it is possible to prevent noise and vibration generated due to backlash and rattling of the gears G14 to G12 constituting the gear train GB and the plurality of gears (not shown). When the take-out roller 78 descends and comes into contact with the paper,
When it rises and is located away from the paper, the load transmitted from the take-out roller 78 to the gear train GB between the take-out roller 78 and the drive motor M2 changes. However, this load fluctuation has a smaller effect than the fluctuation caused by the disconnection of the clutch CR5.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. A modified embodiment of the present invention is illustrated below. (H01) It is possible to arrange an appropriate number of idler gears (including 0) between the retard roller shaft mounting gear and the torque limiter shaft mounting gear of the embodiment. (H02) In the application of the present invention in the paper feeding unit,
The mechanism for contacting or separating the take-out roller with respect to the paper can be omitted. In that case, the take-out roller may be kept in contact with the paper at all times, and may be rotationally driven by the clutch only when necessary. (H03) Brake BR that constitutes rotary braking device T1, T2
Various well-known braking means can be adopted as 1 and BR2. (H04) The present invention can be applied to a technology provided with a load varying device for varying a load acting on a gear train and the gear train in a technical field other than a copying machine. (H05) Brake BR1 constituting the rotary braking device T1
Is a terminal rotating member (1, 2a, 3a, G9 to G11) rotated by a gear G8 at the end of the gear train GA instead of acting on a gear G7 arranged at the end of the gear train GA.
And a gear (G5,
It is possible to act on either G6, G8). (H06) Clutch CR5 constituting the rotary braking device T2
Is provided between the feed roller shaft 71 and the feed roller 7 instead of being provided between the feed roller shaft 71 and the gear G14.
2a, or between the retard roller shaft 83 and the retard roller 72b. In that case, since the feed roller shaft 71 continues to rotate even if the clutch CR5 is turned off, the gears G15 to G19 are
Also continues to rotate. In this case, the brake BR2 constituting the rotary braking device T2 does not act on the gears G7 and G13 arranged at the terminal side of the gear train GB, but instead the gear train G2.
A: Terminal rotation members (71, 72a, 72b, 78, G16 to G24) rotated by the gear G14 at the end of GB and gears (G12, G1) arranged at the end of the gear train GB.
It is possible to act on any of 4). (H07) The gear train (GA; GB) does not need to be composed of only gears, but may be composed of a pulley and a timing belt.

[0053]

The above-described torque transmission device of the present invention can achieve the following effects. (E01) In a torque transmission device using a gear train, gear noise and vibration due to gear backlash and rattling due to fluctuations in the load on the gear train are reduced. (E02) The noise reduction described in the preceding paragraph can be realized without increasing the capacity of the drive motor and using gear materials.

[Brief description of the drawings]

FIG. 1 is an overall explanatory view of a copying machine F having an automatic document feeder B incorporating a first embodiment of a torque transmission device of the present invention and a copying machine body A incorporating a second embodiment. .

FIG. 2 is a plan view of a rotational force transmission device of a document taking-out portion in the document feeding device of the embodiment.

FIG. 3 is a front cross-sectional explanatory view of a transmission mechanism of the rotational force transmission device of FIG.

FIG. 4 is an explanatory view of a sheet feeding unit of the embodiment,
It is a principal part enlarged view of the said FIG.

FIG. 5 is a perspective view of the sheet feeding unit of the embodiment.

FIG. 6 is a perspective view of a main part of the sheet feeding unit of the embodiment, showing a mechanism for pressing the retard roller against the feed roller and the like.

FIG. 7 is an explanatory diagram of a transmission mechanism of the sheet feeding unit according to the embodiment.

FIG. 8 is an explanatory view of the arrangement of the rotation braking device clutch on the feed roller of the paper feeding unit of the embodiment, and is a plan view of relevant parts of FIG. 6;

9 is an explanatory view of a support structure of the retard roller of the embodiment, and is a view corresponding to FIG. 6. FIG.

10 is a diagram showing the load and noise generated in the gear train GA when the load transmitted from the feed roller 2a of the first embodiment in FIG. 2 to the gear train GA is turned on and off by the clutch CR2. It is a figure which shows the state which changes, FIG. 10A is a figure which shows a state when not using a load adjusting device, and FIG. 10B is a figure which shows a state when using a load adjusting device.

[Explanation of symbols]

B ... Automatic document feeder, BR1 ... Brake, BR2 ... Brake, CR2 ... Clutch (load changer), CR5 ... Clutch (load changer), F ... Copier, G ... Gear train, G1 ...
G24 ... Gear, G8 ... Feed roller shaft mounting gear, Ki (i
= 1,2, ...) Document, M1 ... Drive motor, M2 ... Drive motor, TRk ... Document feed tray, U1 ... Paper feed unit (paper feeder), T1 ... Rotation braking device (BR1 + CR2), T2 …
Rotational braking device (BR2 + CR5), 1 ... Take-out roller, 2a
... feed roller (rotation actuating member), 2b ... retard roller, 36-40 ... paper feed tray, 71 ... feed roller shaft, 72a ... feed roller, 72b ... retard roller,
78 ... take-out roller,

Claims (2)

[Claims] 1. A rotational force transmission device having the following requirements: (Y01) a gear train for transmitting the rotational force of a drive motor to a rotary operating member; (Y02) the rotary operating member to the gear train. (Y03) A load changer for changing the load transmitted to the gear train, (Y03) The load of the gear arranged at the terminal side of the gear train is always maintained at a predetermined value or more in accordance with the change in the load of the gear train by the load changer. Load adjustment device. 2. The rotational force transmission device according to claim 1, characterized by having the following requirements: (Y04) a feed roller configured to convey a sheet taken out by a take-out roller from a paper feed tray of a copying machine. The rotation actuating member,
(Y05) the load changing device configured by a clutch provided between the shaft of the feed roller and a feed roller shaft mounting gear mounted on the shaft, (Y06) the load varying device rotated by the rotational force of the drive motor. A rotary braking device that applies a rotary braking force to one of a distal rotary member that transmits the rotational force of the gear at the end of the gear train and a gear that is arranged at the distal end of the gear train, and on / off of the clutch. The operation of the rotary braking device so that the load of the gear arranged on the terminal side of the gear train is always maintained at a predetermined value or more according to the fluctuation of the load transmitted from the feed roller to the gear train by The load adjustment device configured by a braking control device that controls the load control device.