JP5906612B2 - Driving force transmission mechanism - Google Patents

Description

  The present invention relates to a driving force transmission mechanism that transmits a driving force output from a driving source.

  Conventionally, various configurations have been proposed as a driving force transmission mechanism that transmits a driving force output from a driving source (see, for example, Patent Document 1). The driving force transmission mechanism described in Patent Literature 1 extends in parallel with an input-side first-stage small gear formed at an end portion on a free end side of a rotating shaft (driving shaft) of a motor (driving source) and a rotating shaft of the motor. A first-stage large gear formed on one end of a rotatable parallel shaft and meshed with the input-side first-stage gear, a final-stage small gear formed on the other end of the parallel shaft, and a shaft extension line of the rotation shaft of the motor And a final-stage large gear that is fitted to the end of the arranged output shaft and meshes with the final-stage small gear of the parallel shaft. Then, the driving force of the motor is transmitted from the input side first stage gear to the first stage large gear of the parallel shaft by driving and rotating the rotary shaft, and then the parallel shaft is driven to rotate so that the final stage small gear and the final stage gear are driven. It is transmitted to the output shaft through a large gear.

JP 2007-187236 A

  By the way, in the above-described driving force transmission mechanism, the rotating shaft of the motor serving as the driving shaft is cantilevered with the end portion where the input side first stage gear is formed as a free end. The parallel first-stage large gear meshes with one side in the direction orthogonal to the axial direction of the input-side first-stage gear. Therefore, for example, when the load applied to the parallel shaft that is the driven shaft is large, when the driving force of the motor is transmitted, the input-side first-stage gear moves away from the first-stage large gear in the direction that intersects the rotation axis of the motor. In response to the directed reaction force, the motor is displaced in the same direction, and as a result, the rotating shaft of the motor may be eccentric.

  This invention is made | formed in view of such a situation, The objective is to provide the driving force transmission mechanism which can suppress that a drive shaft decenters at the time of transmission of a driving force.

In order to achieve the above object, the driving force transmission mechanism of the present invention is cantilevered so as to be rotationally driven based on the driving force transmitted from the driving source, and the driving gear is provided on the free end side so as to be integrally rotatable. And a first driven shaft provided with a first driven gear supported at a distance from the drive shaft and meshing with the drive gear so as to be integrally rotatable, and the first driven shaft. A shaft and the drive shaft are supported at a position farther from the first driven shaft than the drive shaft at a distance from the first driven shaft in a direction connecting the shaft and the drive shaft, and viewed from the drive shaft with respect to the drive gear. A second driven shaft on which a second driven gear meshed from the side opposite to the side on which the first driven gear meshes is provided so as to be integrally rotatable, the first driven shaft and the second driven shaft driven shaft is different from the driving load each other, the first driven shaft, It is connected to a cutting member that cuts by moving a target conveyed along a feeding path in a direction intersecting the conveying direction of the target based on a driving force transmitted from the driving source so that power can be transmitted. The second driven shaft is provided with a measuring member for measuring the amount of rotation of the second driven gear that specifies the amount of movement of the cutting member, and at least one of the driven shafts having the smaller driving load. The second driven shaft, which is the driven shaft of the two, is supported at both ends .

According to the above configuration, the first driven gear and the second driven gear mesh with the drive gear from the direction against the reaction force received from the counterpart driven gear when the driving force is transmitted. Even if the drive gear receives a reaction force in a direction away from one of the driven gears, displacement of the drive gear in the same direction is restricted by the other driven gear. In particular, the driven gear provided on the driven shaft that is supported at both ends reliably restricts the drive gear from being displaced in the direction intersecting the axial direction of the drive shaft due to the reaction force from the other driven gear. To do. Therefore, it is possible to suppress the eccentricity of the drive shaft during transmission of the drive force from the drive source.
In general, the drive gear receives a reaction force from a driven gear provided on a driven shaft with a large drive load, and receives a reaction force from a driven gear provided on a driven shaft with a small drive load. However, it is easy to displace in the direction intersecting the axial direction of the drive shaft. In this regard, according to the above configuration, even when the driving shaft receives a reaction force from the driven gear provided on the driven shaft having the larger driving load of the two driven shafts, the driving gear from the opposite side to the driven gear. Since the driven shaft with the smaller driving load provided with the driven gear meshing with the both ends is supported at both ends, displacement of the driving shaft provided with the driving gear can be suppressed by the driven shaft supported at both ends.

In addition, the driving force transmission mechanism of the present invention, the first driven shaft is detachably mounted on a unit-by-unit basis together with the cutting member.
According to the above configuration, even when the driving gear receives the reaction force due to the driving load when the cutting member cuts the target from one driven gear connected to the cutting member so that power can be transmitted, the driven gear Since the driven shaft provided with the other driven gear that meshes with the drive gear from the opposite side of the gear is supported at both ends, the cutting member that can suppress the displacement of the drive gear and the eccentricity of the drive shaft and is easy to wear out Can be easily replaced by attaching and detaching the unit.
In addition, the driving force transmission mechanism of the present invention further includes a partition wall that partitions an arrangement area of the gears and a movement area of the cutting member.
According to the above configuration, the partition walls restrict the chips generated when the cutting member moves and cuts the target from reaching each gear of the driving force transmission mechanism. Therefore, it is possible to prevent the drive force transmission operation through each gear in the driving force transmission mechanism from being hindered by the target chips being sandwiched between the meshing portions of the gears of the driving force transmission mechanism.
In the driving force transmission mechanism of the present invention, the first driven shaft and the second driven shaft may sandwich the drive shaft between the driven shafts in a direction intersecting the axial direction of the drive shaft. Arranged in the opposite position.

  According to the above configuration, one driven gear of the two driven gears applies a reaction force to the drive gear from a direction opposite to the reaction direction of the reaction force acting on the drive gear from the other driven gear when the drive force is transmitted. Therefore, the displacement of the drive gear toward the direction away from the other driven gear is effectively suppressed. Therefore, it is possible to more reliably suppress the drive shaft from being eccentric when the driving force is transmitted from the drive source.

1 is a schematic sectional side view of an ink jet printer according to an embodiment of the present invention. The perspective view of a cutter mechanism. (A) is the perspective view which looked at the principal part of the cutter mechanism from the left front diagonally upper direction, (b) is the perspective view which looked at the principal part of the cutter mechanism from the left rear diagonally upward. The perspective view which abbreviate | omitted the frame body of the cutter unit from the state shown in FIG.3 (b). The perspective view which abbreviate | omitted a part of drive motor, the fixed frame, and the attachment frame from the state shown to Fig.3 (a). The fragmentary sectional view at the time of seeing a cutter unit from diagonally right forward. It is drawing which shows typically the gear mechanism of a comparative example, Comprising: (a) is a principal part front view, (b) is a principal part side view, (c) is a principal part side view when a drive shaft is eccentric. BRIEF DESCRIPTION OF THE DRAWINGS It is drawing which shows typically the gear mechanism in embodiment of this invention, Comprising: (a) is a principal part front view, (b) is a principal part side view.

Hereinafter, an embodiment in which the present invention is embodied in an ink jet printer which is a kind of recording apparatus will be described with reference to FIGS.
As shown in FIG. 1, the apparatus main body 12 having a housing shape in the printer 11 has an upper surface 12a formed in a substantially rectangular flat shape along the horizontal direction. On the rear side of the apparatus main body 12, a roll body accommodating portion 15 is rotatably attached via a rotation shaft 16 extending in the left-right direction. Inside the roll body accommodating portion 15, an accommodation space is formed that can accommodate a roll body R <b> 1 in which a sheet S <b> 1 as a long target such as continuous paper is rolled up. Then, the roll body R1 accommodated in the accommodation space rotates around the winding shaft 15a, whereby the sheet S1 is unwound from the roll body R1 and conveyed from the roll body accommodation portion 15 toward the downstream side in the conveyance direction. The

  Further, a door 17 formed in a rectangular plate shape is provided at the rear lower part of the apparatus main body 12 so as to be openable and closable. Further, a roll in which a sheet S2 as a long target is wound in a roll shape at a position below the inside of the apparatus main body 12 and inside the door 17 in the same manner as the roll body accommodating portion 15. A tray 18 containing the body R2 is disposed. The tray 18 can be taken out of the apparatus main body 12 by moving in a direction (front-rear direction) intersecting the vertical direction (up-down direction). Then, the roll body R2 accommodated in the tray 18 rotates about the winding shaft 18a, whereby the sheet S2 is unwound from the roll body R2 and conveyed from the tray 18 toward the downstream side in the conveyance direction.

  A flat support plate 19 that can support the sheets S1 and S2 that are unwound from the roll bodies R1 and R2 and conveyed is disposed at a position above the tray 18 in the apparatus main body 12. A carriage 20 is provided above the support plate 19 and opposed to the support plate 19 so as to be reciprocally movable in the left-right direction intersecting with the conveying direction of the sheets S1 and S2 by a driving means (not shown). Yes. A recording head 21 is supported on the lower surface of the carriage 20. The lower surface of the recording head 21 is a horizontal nozzle forming surface in which a plurality of nozzles (not shown) for ejecting ink are opened. The recording head 21 performs recording by ejecting ink onto the sheets S <b> 1 and S <b> 2 that are transported through the support plate 19.

  Further, in the apparatus main body 12, the sheet S1, S2 unwound from the roll bodies R1, R2 accommodated in the roll body accommodating portion 15 and the tray 18 is conveyed on the support plate 19 along the conveyance path. A mechanism 22 is provided. The conveyance mechanism 22 receives the sheet S1 unwound from the roll body R1 of the roll body accommodating portion 15 along the conveyance path, and the sheet S2 unwound from the roll body R2 of the tray 18. And a second receiving plate 24 received along the transport path. The transport mechanism 22 includes a plurality of transport rollers 25 to 30 and transport roller pairs 31 and 32 that are disposed along the transport path of the sheet S1 and the sheet S2. The transport mechanism 22 switches the transport path of the sheet S1 and the transport path of the sheet S2, and transports one of the sheets to the support plate 19 side.

  Further, in the apparatus main body 12, a discharge conveyance mechanism 33 that discharges the sheets S <b> 1 and S <b> 2 recorded by the recording head 21 to the outside of the apparatus main body 12 is provided. The discharge conveyance mechanism 33 includes a reversing unit 34 for reversing the sheets S1 and S2 recorded by the recording head 21, and a conveyance roller pair 35 and 36 for conveying the sheets S1 and S2. The reversing part 34 is constituted by two guide plates 34a and 34b having a substantially arc-shaped cross section. Both guide plates 34a, 34b are arranged in parallel with a gap in the front-rear direction. That is, a curved inversion path is formed between the guide plates 34a and 34b. Further, the upper end portions of the guide plates 34 a and 34 b are positioned above the upper surface 12 a of the apparatus main body 12. The conveying roller pair 35 is disposed at a position corresponding to the upstream end of the reversing path in the reversing unit 34. Further, the transport roller pair 36 is disposed at a position corresponding to the downstream end of the reversing path in the reversing unit 34.

  Then, the sheets S1 and S2 on which recording is performed by the recording head 21 are conveyed downstream, and both the front and back surfaces are reversed by passing through the reversing path of the reversing unit 34. The inverted sheets S1 and S2 are discharged to the upper surface 12a of the apparatus main body 12 from the discharge port 37 located on the front side of the apparatus main body 12.

  Further, at a position downstream of the conveyance roller pair 32 and upstream of the conveyance roller pair 35 in the conveyance path of the sheets S1 and S2, the width direction (right and left) of the sheets S1 and S2 intersects the conveyance direction. A cutter mechanism 38 that can be cut in a direction) is provided. That is, when the sheets S1 and S2 are cut from the continuous paper state to the single sheet state by the cutter mechanism 38, each time the sheets S1 and S2 are cut, the sheets S1 and S2 are conveyed to the downstream side by the discharge conveyance mechanism 33 one by one. It is discharged to the upper surface 12a of the main body 12.

Next, a specific configuration of the cutter mechanism 38 will be described.
As shown in FIG. 2, the cutter mechanism 38 includes a rectangular parallelepiped main body 39 extending long in the left-right direction. A pair of left and right leg portions 39a and 39b are formed at the left and right ends of the main body 39, and the cutter mechanism 38 is screwed onto a bracket (not shown) in the apparatus main body 12 with each leg 39a and 39b of the main body 39. As a result, it is attached to a predetermined position in the apparatus main body 12. The leg portions 39a and 39b have a substantially U-shape in which the cross-sectional shape of the leg portions 39a and 39b is open at both ends in the longitudinal direction (both left and right sides) of the main body 39. A bent wall portion having a substantially L shape in plan view is formed on the side.

  As shown in FIGS. 2 to 4, a mounting frame 40 having a substantially L shape with the left end bent backward in plan view is fixed to the front surface of the front bent wall portion of the left leg 39 a of the main body 39. It is fixed by a screw 40a. Further, a fixed frame 41 having a substantially U shape with the rear side opened in plan view is fixed to the front surface of the mounting frame 40 by a set screw 41a, and a drive motor 42 as a drive source is supported via the fixed frame 41. Has been. A notch groove 43 is formed downward from the upper end surface of the side wall portion along the front-rear direction on the left end side of the mounting frame 40, and a part of the exterior of the cutter unit 44 is formed with respect to the notch groove 43. A plate-like frame body 45 is inserted from vertically above.

  As shown in FIG. 4, a concave groove 46 is formed downward from the upper end surface of the front wall portion along the left-right direction in the mounting frame 40, and the upper end surface of the front wall portion along the left-right direction in the fixed frame 41. A concave groove 47 corresponding to the concave groove 46 of the mounting frame 40 in the front-rear direction is formed downward. The tip of the drive shaft 42 a in a cantilever-supported state in the drive motor 42 is inserted behind the front wall portion of the mounting frame 40 through the concave groove 46 and the concave groove 47. Therefore, the drive gear 48 (drive gear) provided at the tip which is the free end of the drive shaft 42a of the drive motor 42 so as to rotate integrally with the drive shaft 42a is connected to the front bent wall portion of the left leg portion 39a and to this. The mounting frame 40 is located in a disposition area partitioned rearward from the mounting frame 40.

  As shown in FIGS. 3B, 4, and 5, the first driven shaft 49 a is vertically rotatable with respect to the frame body 45 of the cutter unit 44 on the vertical upper side of the drive shaft 42 a. The cantilever is supported so as to be parallel to the drive shaft 42 a of the drive motor 42. At the tip of the first driven shaft 49a, a driven gear 49 as a first driven gear is provided so as to be integrally rotatable with the first driven shaft 49a, and is perpendicular to the drive gear 48 positioned below the first driven shaft 49a. It meshes so that power can be transmitted from above.

  Also, as shown in FIG. 5, vertically below the drive shaft 42a (ie, a position farther away from the first driven shaft 49a than the drive shaft 42a in the direction connecting the first driven shaft 49a and the drive shaft 42a). The second driven shaft 50 a is supported so as to be parallel to the drive shaft 42 a of the drive motor 42. One end (rear end in FIG. 5) of the second driven shaft 50a is concentrically connected to the rotary shaft 52a of the rotary encoder 52 that supports the slit disk 51, and the other end (front end in FIG. 5). ) Is rotatably supported with respect to a bearing hole 40b (see FIG. 8) penetratingly formed below the groove 46 in the front wall portion of the mounting frame 40.

  An encoder gear 50 as a second driven gear is provided at the central portion of the second driven shaft 50a so as to be able to rotate integrally with the second driven shaft 50a, with respect to the drive gear 48 positioned above the encoder gear 50. It meshes so that power can be transmitted from vertically below. That is, the encoder gear 50 meshes with the drive gear 48 from the side opposite to the side with which the driven gear 49 meshes when viewed from the drive shaft 42a. Specifically, each shaft 49a, 42a, 50a is located on the same straight line extending in the vertical direction with the drive shaft 42a interposed between the first driven shaft 49a and the second driven shaft 50a. The driven gear 49 and the encoder gear 50 are arranged at opposite positions sandwiching the drive gear 48 from the upper and lower sides.

  The rotary encoder 52 is fixed to a support frame (not shown) provided in an arrangement area on the rear side of the mounting frame 40. Therefore, the second driven shaft 50a in which the encoder gear 50 is provided so as to be integrally rotatable is different from the drive shaft 42a and the first driven shaft 49a in a form in which only one end is cantilevered. Both ends are supported in such a manner that both ends thereof are rotatably supported.

  6 is a partial sectional view in which the main body 39 is omitted from the cutter mechanism 38. As shown in FIG. 6, a round blade 53 as a cutting member is rotated on the front surface of the frame body 45 of the cutter unit 44. A freely mounted cutter carriage 54 is supported so as to be capable of reciprocating in the left-right direction intersecting the conveying direction of the sheets S1, S2. The round blade 53 is provided substantially at the center of the lower surface of the cutter carriage 54 and protrudes downward from the lower surface of the cutter carriage 54. As shown in FIG. 2, a lower blade 55 is provided at a position in the frame body 45 that faces the round blade 53 in the vertical direction. The lower blade 55 extends over substantially the entire region of the frame body 45 in the left-right direction.

  In addition, a driven gear (not shown) is freely rotatable at the right end of the frame body 45 opposite to the position where the driven gear 49 is disposed across the moving area of the cutter carriage 54 (also the moving area of the round blade 53). Is provided. These driven gears 49 are stepped gears, and a toothed portion that can mesh with the drive gear 48 is formed on the large-diameter portion on the distal end side in the axial direction, and a small-diameter portion that continues to the proximal end side of the large-diameter portion. Is a pulley part 49b having a circular arc surface. An endless belt 56 partially connected to the cutter carriage 54 is hung between the pulley portions 49b of the pair of left and right driven gears 49.

  Next, the operation of the printer 11 configured as described above will be described below, particularly focusing on the operation when the driving gear 48 of the driving motor 42 transmits the driving force to the cutter carriage 54.

  Now, in the printer 11 of this embodiment, when the drive shaft 42a of the drive motor 42 is rotationally driven, the drive gear 48 provided at the tip of the drive shaft 42a rotates. Then, the driven gear 49 and the encoder gear 50 meshed with the drive gear 48 are driven to rotate along with the drive gear 48. The driven gear 49 and the encoder gear 50 drive a load (the cutter carriage 54 and the slit disk 51) to which the driven gear 49 and the encoder gear 50 are connected so as to be able to transmit power, and apply a reaction force corresponding to the driving load to the drive gear 48. Act against.

  First, in the case of the driven gear 49, when the driven rotation is performed based on the driving force transmitted from the driving gear 48, the belt 56 that is hooked on the pulley portion 49 b moves around, and as a result, the cutter carriage 54 connected to the belt 56. Is moved left and right. Then, the round blade 53 mounted on the cutter carriage 54 rolls in the left-right direction with respect to the cutting edge of the lower blade 55, and the sheets S 1 and S 2 sandwiched between the round blade 53 and the lower blade 55 move in the moving direction of the round blade 53. Is cut in the left-right direction. Accordingly, the driven gear 49 and the first driven shaft 49a that supports the driven gear 49 are loaded with the power required to move the cutter carriage 54 on which the round blade 53 is mounted and the belt 56 connected thereto. A reaction force corresponding to the load acts on the drive gear 48 and the drive shaft 42a that supports the drive gear 48.

  On the other hand, in the case of the encoder gear 50, when the driven rotation is performed based on the driving force transmitted from the driving gear 48, the slit disk 51 connected through the second driven shaft 50a and the rotating shaft 52a rotates, and the round blade The rotation amount of the encoder gear 50 corresponding to the rotation amount of the driven gear 49 that specifies the movement amount of 53 is measured by the rotary encoder 52. The encoder gear 50 and the second driven shaft 50a that supports the encoder gear 50 are applied with a power necessary for rotating the slit disk 51 as a load, and a reaction force corresponding to the load is applied to the drive gear 48 and this. It acts on the drive shaft 42a that supports the motor.

  It should be noted that the driving load for moving the cutter carriage 54 and the like on the driven gear 49 and the first driven shaft 49a is larger than the driving load for rotating the slit disk 51 on the encoder gear 50 and the second driven shaft 50a. large. Therefore, when both the upper driven gear 49 and the lower encoder gear 50 are driven to rotate with the driving rotation of the driving gear 48, the reaction force from the driven gear 49 having a relatively large driving load is relatively higher. Therefore, in order to overcome the reaction force from the encoder gear 50 having a small drive load, the reaction force acts on the drive gear 48 in a vertically downward direction away from the driven gear 49. It should be noted that the drive shaft 42a of the drive gear 48 is cantilevered so that only the front side, which is one side in the axial direction, can rotate. Therefore, the drive gear 48 and the drive shaft 42a are likely to be displaced in the same direction when a reaction force acts vertically downward from the driven gear 49.

  Here, as in the gear mechanism of the comparative example shown in FIGS. 7A to 7C, the second driven of the encoder gear 50 provided on the opposite side of the driven gear 49 with the drive gear 48 interposed therebetween. It is assumed that the shaft 50a is cantilevered so that only one side in the axial direction (only the front side in FIG. 7B) can rotate. In the case of such a cantilever support form, the encoder gear 50 and the second driven shaft 50a that supports the encoder gear 50 are likely to be displaced in the same direction when a force acts in a direction intersecting the axial direction. As a result, when the drive gear 48 is pressed vertically downward by the reaction force acting from the driven gear 49, the encoder gear 50 cannot restrict the drive gear 48 from being displaced vertically downward. Therefore, when the driving force is transmitted from the driving gear 48 to the driven gear 49, the driving gear 48 is displaced vertically downward together with the encoder gear 50 as shown in FIG. Move away. Then, the drive shaft 42 a of the drive motor 42 is eccentric with the displacement of the drive gear 48.

  In this regard, as shown in FIGS. 8A and 8B, in this embodiment, the second driven shaft of the encoder gear 50 provided on the opposite side of the driven gear 49 with the drive gear 48 interposed therebetween. 50a is supported at both ends in the axial direction so as to be rotatable. In this case, the encoder gear 50 is not easily displaced in the same direction even if a force is applied in a direction intersecting the axial direction. As a result, when the drive gear 48 is pressed vertically downward by the reaction force acting from the driven gear 49, the encoder gear 50 restricts the drive gear 48 from being displaced vertically downward. Therefore, when the driving force is transmitted from the driving gear 48 to the driven gear 49, the driving gear 48 is hardly displaced vertically downward so as to move away from the driven gear 49, and the driving shaft 42a of the driving motor 42 is eccentric. Is suppressed.

  In particular, in this embodiment, the encoder gear 50 is disposed at a position opposite to the driven gear 49 with the drive gear 48 interposed therebetween. When the driving force is transmitted from the driving gear 48 to the driven gear 49, the driving gear 48 meshes with the driving gear 48 from the direction opposite to the direction of the reaction force acting on the driving gear 48 from the driven gear 49. Therefore, the encoder gear 50 more reliably suppresses the displacement of the drive gear 48 in the direction away from the driven gear 49. Therefore, the drive shaft 42a is more reliably prevented from being eccentric when the drive force is transmitted from the drive motor 42.

  In the present embodiment, the drive gear 48, the driven gear 49, and the encoder gear 50 are spaces partitioned by the bent leg portions 39 a and the mounting frame 40 with respect to the cutting regions of the sheets S 1 and S 2 by the cutter mechanism 38. Is located in the area. In this respect, the leg portion 39a having the bent wall portion and the mounting frame 40 function as a partition wall that partitions the arrangement region of the gears 48 to 50 and the movement region of the round blade 53. Therefore, the leg 39a and the mounting frame 40 restrict the chips generated when the cutter mechanism 38 cuts the sheets S1 and S2 from reaching the drive gear 48, the driven gear 49, and the encoder gear 50. Therefore, the cutting operation of the driving force through the driving gear 48 is inhibited by the chips of the sheets S1 and S2 being sandwiched between the meshing portions of the driving gear 48, the driven gear 49, and the encoder gear 50. .

  In the present embodiment, the cutter unit 44 having the round blade 53 is detachably inserted into the mounting frame 40 from vertically above. Therefore, the exchange of the round blade 53 that is easily consumed is easily performed by attaching and detaching the cutter unit 44 in units.

According to the above embodiment, the following effects can be obtained.
(1) The drive gear 48 moves away from the driven gear 49 because the encoder gear 50 meshes with the drive gear 48 in a direction against the reaction force received from the driven gear 49 when the driving force is transmitted. Even if a reaction force is applied in the direction, the encoder gear 50 restricts displacement in the same direction. In particular, the encoder gear 50 provided on the second driven shaft 50a that is supported at both ends receives the reaction force from the driven gear 49, and the drive gear 48 is displaced toward the direction intersecting the axial direction of the drive shaft 42a. Be sure to regulate what you do. Therefore, the drive shaft 42a can be prevented from being eccentric when the drive force is transmitted from the drive motor 42.

  (2) Even when the drive shaft 42a receives a reaction force from the driven gear 49 provided on the first driven shaft 49a having the larger driving load of the driven shafts 49a and 50a, it is opposite to the driven gear 49. Since the second driven shaft 50a having a smaller driving load and provided with an encoder gear 50 that meshes with the drive gear 48 from the side is supported at both ends, the second driven shaft 50a that is supported at both ends supports the drive. The displacement of the drive shaft 42a provided with the gear 48 can be suppressed.

  (3) Since the encoder gear 50 causes the reaction force to act on the drive gear 48 from the direction opposite to the direction of the reaction force acting on the drive gear 48 from the driven gear 49 when the drive force is transmitted, the drive gear 48 is driven. Displacement toward the direction away from the gear 49 is effectively suppressed. Therefore, it is possible to more reliably suppress the drive shaft 42a from being eccentric when the driving force is transmitted from the drive motor 42.

  (4) Even when the driving gear 48 receives the reaction force due to the driving load when the round blade 53 cuts the sheets S1 and S2 from the driven gear 49 connected to the round blade 53 so that power can be transmitted, Since the second driven shaft 50a provided with the encoder gear 50 that meshes with the drive gear 48 from the opposite side to the driven gear 49 is supported at both ends, the displacement of the drive gear 48 and the eccentricity of the drive shaft 42a are suppressed. In addition, it is possible to easily replace the round blade 53 that is easily consumed by attaching and detaching the cutter unit 44 in units.

  (5) The attachment frame 40 restricts the chips generated when the round blade 53 moves and cuts the sheets S1, S2 from reaching the gears 48, 49, 50. Therefore, when the chips of the sheets S1, S2 are sandwiched between the meshing portions of the gears 48, 49, 50, it is possible to prevent the transmission operation of the driving force through the gears 48, 49, 50 from being hindered.

In addition, you may change the said embodiment into another embodiment as follows.
In the above embodiment, the arrangement region of the drive gear 48, the driven gear 49, and the encoder gear 50 and the cutting region of the sheets S1, S2 by the cutter mechanism 38 are configured by the left leg 39a, the mounting frame 40, and the like. It is good also as a structure which is not partitioned off by a partition wall.

  In the above embodiment, the driven gear 49 may mesh with the drive gear 48 from vertically above. Further, the encoder gear 50 may be engaged with the drive gear 48 from vertically below. That is, if the driven gear 49 and the encoder gear 50 are configured to mesh with the drive gear 48 from the opposite side, the driven gear 49 and the encoder gear 50 are not necessarily arranged at positions opposite to each other with the drive gear 48 interposed therebetween.

  In the above embodiment, the cutter unit 44 may be mounted on the main body 39 from below vertically. In this case, it is desirable that the encoder gear 50 meshes with the drive gear 48 from the upper side opposite to the driven gear 49 with the drive gear 48 interposed therebetween.

In the embodiment described above, the first driven shaft 49a having the driven gear 49 may be supported on both sides in the axial direction so as to be rotatable.
In the above embodiment, the driving force transmission mechanism may be constituted by four or more gears including a driving gear. In this case, it is desirable that the rotating shaft of at least one of the gears meshed with the drive gear from both sides sandwiching the drive gear is rotatably supported.

  In the above embodiment, the target to be transported is not limited to the sheets S1 and S2, and any transport medium may be employed. Moreover, a conveyance medium is not limited to the elongate conveyance medium wound by roll shape, You may employ | adopt a sheet-form conveyance medium.

  In the above embodiment, the driven gear that meshes from the opposite side of the driven gear 49 across the drive gear 48 is not limited to the encoder gear 50, but any driven gear that can mesh with the drive gear 48. A gear may be adopted.

  In the above embodiment, the driving target to which the driven gear 49 transmits the driving force from the driving motor 42 is not limited to the cutter carriage 54, and an arbitrary target is adopted as the driving target to transmit the driving force from the driving motor 42. May be.

  In the above embodiment, the drive source is not limited to the drive motor 42, and a drive source of an arbitrary drive method may be adopted.

  39a ... left leg constituting partition wall, 40 ... mounting frame constituting partition wall, 42 ... drive motor as drive source, 42a ... drive shaft, 48 ... drive gear as drive gear, 49 ... first driven A driven gear as a gear, 49a ... a first driven shaft, 50 ... an encoder gear as a second driven gear, 50a ... a second driven shaft, 53 ... a round blade as a cutting member, S1, S2 ... as a target Sheet.

Claims (4)

A drive shaft which is cantilevered so as to be rotationally driven based on a driving force transmitted from a drive source, and a drive gear is provided on the free end side so as to be integrally rotatable;
A first driven shaft provided with a first driven gear supported at a distance from the drive shaft and meshing with the drive gear so as to be integrally rotatable;
The drive shaft is supported at a distance from the first driven shaft at a position farther from the first driven shaft than the drive shaft in a direction connecting the first driven shaft and the drive shaft. A second driven shaft on which a second driven gear meshed from the side opposite to the side meshed with the first driven gear as viewed from the drive shaft is provided so as to be integrally rotatable;
The first driven shaft and the second driven shaft have different driving loads, and the first driven shaft transmits a driving force transmitted from the driving source to a target transported along a transport path. Is connected to a cutting member that cuts by moving in a direction that intersects the conveying direction of the target, and the second driven shaft specifies the amount of movement of the cutting member. A measuring member for measuring a rotation amount of the second driven gear is provided;
A driving force transmission mechanism in which the second driven shaft, which is a driven shaft having a smaller driving load, is supported at both ends . The driving force transmission mechanism according to claim 1 ,
The drive force transmission mechanism according to claim 1, wherein the first driven shaft is detachable in units with the cutting member. In the driving force transmission mechanism according to claim 1 or claim 2 ,
A driving force transmission mechanism, further comprising a partition wall that partitions an arrangement area of each gear and a movement area of the cutting member. In the driving force transmission mechanism according to any one of claims 1 to 3 ,
The first driven shaft and the second driven shaft are arranged at positions opposite to each other with the drive shaft sandwiched between the driven shafts in a direction intersecting the axial direction of the drive shaft. Drive force transmission mechanism.

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