JP2010172623A - Cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool which is easy to assemble and the expected cutting performance is provided. <P>SOLUTION: An electric scissors 1A is provided with a first movable blade 2A and second movable blade 3A supported rotataly on the shaft 4A. In the shaft 4A, the shaft part 43A is inserted to the bearing hole of the first movable blade 2A and the second movable blade 3A, and A washer 45A and an O-ring 46A are attached to the washer receiving part 47b formed in an end of the shaft part 43A. When a screw 44A is fixed to the extent that the washer 45A is pressed to the washer receiving part 47b, the first movable blade 2A and the second movable blade 3A are pressed in the thickness direction by the O-ring 46A and assembled so as not to cause a rattle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cutting tool that opens and closes a blade portion to cut an object to be cut.

  As a cutting tool that opens and closes a blade and cuts an object to be cut, scissors that manually open and close the blade are known. Conventionally, humans have been opening and closing scissors by hand and pruning branch trees, etc., but in order to save labor, the blades are opened and closed by the driving force of the motor to cut cutting objects such as branches. Electric scissors that can be cut have been proposed.

  The electric scissors have a fixed blade and a movable blade that can rotate about a shaft, and a structure called a link type and a structure called a gear type are known as driving methods for the movable blade.

  In the link type electric scissors, the movable blade has a blade portion on one side of the shaft and an arm portion on the other side, and is configured in an L shape, for example. Further, a ball screw for converting the rotation operation of the motor into a linear operation of the nut portion and a link for connecting the nut portion and the arm portion of the movable blade are provided. In such a configuration, the linear movement of the nut portion is transmitted to the arm portion of the movable blade via the link, and the movable blade rotates about the shaft as a fulcrum (see, for example, Patent Document 1).

  In the gear-type electric scissors, the movable blade has an arc-shaped gear coaxial with the shaft, and the rotational operation of the motor is transmitted to the movable blade by a mechanism combining a bevel gear and a flat gear ( For example, see Patent Document 2).

Japanese Patent No. 2735218 Japanese Patent No. 3537649

  In conventional scissors, threading is performed on a shaft hole on one side of a scissor blade, and the blade portion is fixed by the scissor shaft subjected to threading. Furthermore, it is fixed with a nut to prevent the shaft from loosening. When it is necessary to polish the blade edge due to spillage or wear of the blade edge, the nut and shaft are removed, and the blade is polished or replaced.

  However, if the shaft is tightened too much when the shaft is fastened in the assembly after polishing or replacement, the movement of the blade portion becomes worse, and if the tightening method is loose, the blade edge opens and causes a cutting failure. For this reason, with the conventional scissors, it is difficult to tighten the shaft, and in order to obtain the desired cutting performance, assembly is required.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a cutting tool that can be easily assembled and can obtain a desired cutting performance.

  In order to solve the above-described problem, the present invention provides a first blade portion that is rotatably supported by a shaft as a fulcrum, and a second object that sandwiches a cutting object by the rotation operation of the first blade portion that has the shaft as a fulcrum. The shaft is attached to a shaft portion that is inserted into a bearing hole formed in the first blade portion and the second blade portion, and a receiving portion that is formed at an end portion of the shaft portion, The pressing member whose position in the axial direction is regulated by the receiving portion and the pressing member fastened to the end portion of the shaft portion and attached to the receiving portion are pressed along the axial direction. The fastening member that is fastened until the position in the direction is regulated, and the fastening member is fastened to the shaft portion, so that the pressing member whose axial position is regulated by the receiving portion is pressed by the first blade portion. It is a cutting tool provided with the elastic member which presses a 2nd blade part in the thickness direction.

  In the present invention, the first blade portion and the second blade portion are rotatably supported by inserting the shaft portion into the bearing hole. A pressing member is attached to the receiving portion of the shaft portion inserted into the bearing holes of the first blade portion and the second blade portion. When the fastening member is fastened until the position of the pressing member in the axial direction is restricted by the receiving portion, the elastic member is pressed by the pressing member whose axial position is restricted by the receiving portion, and the first blade portion and the second blade portion are pressed. The blade is pressed in the thickness direction.

  According to the present invention, the fastening member may be fastened until the axial position of the pressing member is regulated by the receiving portion, and it is not necessary to adjust the fastening force of the fastening member. And since the 1st blade part and the 2nd blade part are pressed in the thickness direction by the elastic force of an elastic member, the good movement of the 1st blade part and the 2nd blade part is not spoiled, and each component It is possible to cope with changes in thickness due to tolerance accumulation in the thickness direction. Thereby, even if it performs the exchange operation | work of a blade, and the attachment or detachment for sharpening a blade, the expected cutting performance can be obtained, without adjusting the fastening force of a fastening member.

It is a sectional side view which shows an example of a structure of the electric scissors of 1st Embodiment. It is a sectional side view which shows an example of a structure of the electric scissors of 1st Embodiment. It is a side view which shows an example of a structure of the electric scissors of 1st Embodiment. It is AA sectional drawing which shows 1st Embodiment of the attachment structure of a blade part. It is a disassembled perspective view which shows 1st Embodiment of the attachment structure of a blade part. It is sectional drawing which shows the modification of the attachment structure of the blade part in 1st Embodiment. It is a sectional side view which shows an example of a structure of the electric scissors of 2nd Embodiment. It is a sectional side view which shows an example of a structure of the electric scissors of 2nd Embodiment. It is sectional drawing which shows 2nd Embodiment of the attachment structure of a blade part.

  Hereinafter, an embodiment of electric scissors as an example of a cutting tool of the present invention will be described with reference to the drawings.

<Configuration example of the electric scissors of the first embodiment>
1 and 2 are side sectional views showing an example of the configuration of the electric scissors according to the first embodiment. FIG. 1 shows a state in which the blade is opened, and FIG. 2 shows a state in which the blade is closed. . FIG. 3 is a side view showing an example of the configuration of the electric scissors according to the first embodiment.

  In the electric scissors 1A of the first embodiment, the first movable blade 2A and the second movable blade 3A are supported so as to be rotatable about the shaft 4A.

  In the electric scissors 1A, the rotation operation of the motor 5 is converted into a linear operation by the ball screw mechanism 6, and the driving force of the motor 5 converted into the linear operation is converted into the first movable blade 2A and the second by the toggle link mechanism 7A. Transmitted to the movable blade 3A, the first movable blade 2A and the second movable blade 3A are opened and closed by a rotating operation with the shaft 4A as a fulcrum.

  The electric scissors 1A are provided with two frames 8A sandwiching the ball screw mechanism 6, the shaft 4A is supported by the frame 8A, and the movement of the ball screw mechanism 6 and the toggle link mechanism 7A is guided by the frame 8A. Further, the electric scissors 1 </ b> A has a configuration in which each component described above is attached to the housing 9, and the user can work with the housing 9.

  Details of each component will be described below. The first movable blade 2A is an example of a first blade portion. The first movable blade 2A is provided with a blade forming portion 20A on one side across the support position by the shaft 4A, and the angle formed with the blade forming portion 20A is predetermined on the other side. The blade arm 21A is provided as a transmission portion formed at an obtuse angle. In the first movable blade 2A, the blade forming portion 20A and the blade arm 21A may be integrated. However, in order to facilitate replacement of the blade forming portion 20A, the blade forming portion 20A and the blade arm 21A are independent components. It is good to configure.

  The second movable blade 3A is an example of a second blade portion. The second movable blade 3A is provided with a blade forming portion 30A on one side across the support position by the shaft 4A, and the angle formed with the blade forming portion 30A is predetermined on the other side. The blade arm 31A is provided as a transmission portion formed at an obtuse angle. Similarly to the first movable blade 2A, the second movable blade 3A may be configured such that the blade forming portion 30A and the blade arm 31A are integrated, but in order to facilitate replacement of the blade forming portion 30A, the blade forming portion 30A and the blade arm 31A may be composed of independent parts.

  4 is a cross-sectional view taken along the line AA of FIG. 1 showing the first embodiment of the blade attachment structure, and FIG. 5 is an exploded perspective view showing the first embodiment of the blade attachment structure. .

  The first movable blade 2 </ b> A and the second movable blade 3 </ b> A include a first mounting bracket 40 </ b> A fixed to one frame 8 </ b> A and the housing 9, and a second frame 8 </ b> A and second housing fixed to the housing 9. It is supported and attached to the shaft 4A between the attachment fittings 41A.

  The first mounting bracket 40A is formed of a component in which a bearing portion 42c in which a bearing hole 42b is formed is independent of the mounting portion 42a fixed to the frame 8A and the housing 9. The first mounting bracket 40A is fixed to the housing 9 with, for example, four screws 42d, the bearing portion 42c is fixed to the mounting portion 42a with two screws 42d, and the two screws 42d are removed, It can be attached to and detached from the attachment portion 42a. The second mounting bracket 41A is constituted by a part in which a part fixed to the frame 8A and the housing 9 and a part where the bearing hole 42b is formed are integrated.

  The first mounting bracket 40A has a step on the inner surface in contact with the first movable blade 2A around which the washer 42e is inserted around the bearing hole 42b. Further, the second mounting bracket 41A has a step in which a washer 42e can be inserted around the bearing hole 42b on the inner surface in contact with the second movable blade 3A.

  The first mounting bracket 40A and the second mounting bracket 41A fixed to the frame 8A and the housing 9 have bearing holes 42b arranged coaxially. Further, the interval between the first mounting bracket 40A and the second mounting bracket 41A in which the washer 42e is inserted in the stepped portion is configured to be approximately equal to the thickness of the first movable blade 2A and the second movable blade 3A overlapped. Is done.

  In the first movable blade 2A, the blade forming portion 20A and the blade arm 21A are overlapped with each other by aligning the positions of the bearing hole 22A formed in the blade forming portion 20A and the bearing hole 23A formed in the blade arm 21A. Further, a pin (not shown) protruding from the blade arm 21A is inserted into a hole 24A formed in the blade forming portion 20A, so that the blade forming portion 20A and the blade arm 21A are integrated.

  In the second movable blade 3A, the blade forming portion 30A and the blade arm 31A are overlapped by aligning the positions of the bearing hole 32A formed in the blade forming portion 30A and the bearing hole 33A formed in the blade arm 31A. Further, the pin 34A protruding from the blade arm 31A is inserted into the hole 35A formed in the blade forming portion 30A, and the blade forming portion 30A and the blade arm 31A are integrated.

  The first movable blade 2A and the second movable blade 3A are overlapped with the position of the bearing hole aligned, and are inserted between the first mounting bracket 40A and the second mounting bracket 41A. Washers 42e are inserted between the first movable blade 2A and the first mounting bracket 40A and between the second movable blade 3A and the second mounting bracket 41A, respectively.

  Then, the shaft 4A is inserted into the bearing holes 42b of the first mounting bracket 40A and the second mounting bracket 41A and the bearing holes of the first movable blade 2A and the second movable blade 3A, so that the first movable blade 2A and the second movable blade 3A are rotatably supported by the first mounting bracket 40A and the second mounting bracket 41A.

  When the first mounting bracket 40A and the second mounting bracket 41A are made of aluminum and the first movable blade 2A and the second movable blade 3A are made of iron, each mounting bracket and the movable blade are directly connected to each other. When in contact, the mounting bracket is worn by the rotation of the movable blade. Therefore, a washer 42e is sandwiched between the first mounting bracket 40A and the first movable blade 2A, and between the second mounting bracket 41A and the second movable blade 3A, respectively, and the mounting bracket and the movable blade are movable. The blade is not in direct contact.

  The shaft 4A includes a bearing hole 42b of the first mounting bracket 40A and the second mounting bracket 41A, a shaft portion 43A inserted into the bearing holes of the first movable blade 2A and the second movable blade 3A, and a shaft portion. A screw 44A fastened to 43A, a washer 45A and an O-ring 46A for pressing the first movable blade 2A and the second movable blade 3A in the axial direction are provided.

  The shaft portion 43A is a cylinder having a diameter inserted into the bearing holes 42b of the first mounting bracket 40A and the second mounting bracket 41A and the bearing holes of the first movable blade 2A and the second movable blade 3A. In shape, a flange portion 47a is formed on the outer periphery of one end portion.

  Further, the shaft portion 43A is provided with a step whose diameter decreases on the outer periphery of the other end portion, and a washer receiving portion 47b to which the washer 45A is attached is formed. Further, the shaft portion 43A is formed with a screw portion 47c to which the screw 44A is fastened on the inner periphery of the other end portion.

  The shaft portion 43A has a length from the flange portion 47a to the stepped portion of the washer receiving portion 47b, the first mounting bracket 40A and the second mounting bracket 41A, the first movable blade 2A and the second movable blade 3A. It is configured to be slightly longer than the stacked thickness.

  The screw 44A is an example of a fastening member, and a flange portion 47d that presses the washer 45A is formed. The washer 45A is an example of a pressing member, and is configured to be slightly thicker than the length of the washer receiving portion 47b of the shaft portion 43A. In addition, the washer 45A has a configuration in which an annular groove is formed on the surface facing the second mounting bracket 41A, and the O-ring 46A is prevented from being displaced.

  The O-ring 46A is an example of an elastic member, and is inserted between the washer 45A and the second mounting bracket 41A.

  The flange portion 47a of the shaft portion 43A inserted into the bearing holes 42b of the first mounting bracket 40A and the second mounting bracket 41A and the bearing holes of the first movable blade 2A and the second movable blade 3A has the first flange portion 47a. The washer receiving portion 47b protrudes from the second mounting bracket 41A.

  The washer 45A fitted to the washer receiving portion 47b of the shaft portion 43A protruding from the second mounting bracket 41A is a step between the flange portion 47d of the screw 44A fastened to the screw portion 47c of the shaft portion 43A and the washer receiving portion 47b. It is sandwiched between the parts.

  The washer 45A is configured to be slightly thicker than the length of the washer receiving portion 47b of the shaft portion 43A. When the screw 44A is fastened until the washer 45A contacts the stepped portion of the washer receiving portion 47b, the flange portion 47d of the screw 44A, A gap is formed between the end of the washer receiving portion 47b of the shaft portion 43A.

  Thus, when the screw 44A is fastened until the washer 45A comes into contact with the stepped portion of the washer receiving portion 47b, the screw 44A cannot be tightened any further. The washer 45A is sandwiched between the flange portion 47d of the screw 44A and the stepped portion of the washer receiving portion 47b, and movement in the axial direction is restricted.

  On the other hand, the shaft portion 43A has a length from the flange portion 47a to the stepped portion of the washer receiving portion 47b, the first mounting bracket 40A and the second mounting bracket 41A, the first movable blade 2A and the second movable blade. Since it is configured to be slightly longer than the thickness of the blade 3A, the gap is generated between the second mounting bracket 41A and the washer 45A.

  In the washer 45A, an O-ring 46A is inserted into an annular groove formed on the surface facing the second mounting bracket 41A. The O-ring 46A projects from the surface of the washer 45A that faces the second mounting bracket 41A. The protruding amount of the O-ring 46A is configured to be larger than the gap between the second mounting bracket 41A and the washer 45A.

  Accordingly, when the screw 44A is fastened until the washer 45A comes into contact with the stepped portion of the washer receiving portion 47b, the O-ring 46A is crushed between the second mounting bracket 41A and the washer 45A. The first movable blade 2A and the second movable blade 3A between the first mounting bracket 40A and the second mounting bracket 41A are along the axis by the elastic force generated by the O-ring 46A being crushed. Pressed in the direction.

  Therefore, by fastening the screw 44A until the washer 45A contacts the stepped portion of the washer receiving portion 47b, the blade forming portion 20A of the first movable blade 2A and the second without adjusting the tightening force of the screw 44A. The movable blades 3A are assembled with no backlash between the blade forming portions 30A.

  On the other hand, the first movable blade 2A and the second movable blade 3A are formed by attaching / detaching the shaft 4A by removing the screw 44A and attaching / detaching the bearing portion 42c of the first mounting bracket 40A. It can be exchanged.

  In this example, the shaft 4A has an oiling function. That is, the shaft portion 43 </ b> A has an oil filling space 48 formed inside one end portion, and an oil supply port 48 a connected to the oil filling space 48 is formed at one end portion. An oil supply port 48b connected to the oil supply space 48 is formed on the outer periphery.

  Further, the oil supply space 48 is fastened to a ball 49a that can be opened and closed, a coil spring 49b that presses the ball 49a, and a screw portion 47c of the shaft portion 43A to seal the oil supply space 48. In addition, a lid portion 49c is provided that presses the ball 49a against the oil filler port 48a with a coil spring 49b.

  In the shaft 4A, the oil filler port 48a is normally closed with a ball 49a. When lubricating, the ball 49a is pushed with a nozzle (not shown). As a result, the coil spring 49b is pushed by the ball 49a, and the oil supply port 48a is opened. When oil is supplied to the oil supply space 48 with a nozzle (not shown) and the nozzle is removed, the ball 49a is pressed against the oil supply port 48a by the coil spring 49b, and the oil supply port 48a is closed with the ball 49a to prevent oil leakage.

  The oil supplied to the oil supply space 48 is supplied between the outer periphery of the shaft portion 43A and the bearing holes of the first movable blade 2A and the second movable blade 3A from the oil supply port 48b.

  1 and 2, the motor 5 and the ball screw mechanism 6 are examples of a drive unit, and the motor 5 is connected to a speed reducer 50 whose drive shaft uses, for example, a planetary gear. The ball screw mechanism 6 includes a screw shaft 60 connected to the output shaft of the speed reducer 50 and a nut portion 61 in which a ball (not shown) to be inserted into a screw groove of the screw shaft 60 is incorporated.

  In the ball screw mechanism 6, a guide shaft 62 provided on the nut portion 61 is inserted into a guide groove 80 provided on the frame 8 </ b> A in a direction parallel to the screw shaft 60. In the ball screw mechanism 6, when the screw shaft 60 is driven to rotate, the rotation of the nut portion 61 about the screw shaft 60 is regulated by the guide shaft 62 being guided in the guide groove 80, and the nut portion 61 is screwed. Move linearly along axis 60.

  Thereby, in the ball screw mechanism 6, the rotation operation of the motor 5 is converted into the linear operation of the nut portion 61, and the moving direction of the nut portion 61 is switched according to the rotation direction of the motor 5.

  The toggle link mechanism 7A includes a first link 71A and a second link 72A that are rotatably connected by a drive shaft 70A. In the toggle link mechanism 7A, one end of the first link 71A and the blade arm 21A of the first movable blade 2A are rotatably connected with a shaft 73A as a fulcrum. In addition, one end of the second link 72A and the blade arm 31A of the second movable blade 3A are rotatably connected with the shaft 74A as a fulcrum. Furthermore, the other end portion of the first link 71A and the other end portion of the second link 72A are rotatably connected with the drive shaft 70A as a fulcrum.

  The toggle link mechanism 7A is configured such that the blade arm 21A of the first movable blade 2A and the first link 71A are bent at the connecting portion by the shaft 73A, and the blade arm 31A and the second link of the second movable blade 3A. 72A is bent at the connecting portion by the shaft 74A. Further, the first link 71A and the second link 72A are bent at the connecting portion by the drive shaft 70A.

  The toggle link mechanism 7A is supported such that the drive shaft 70A is guided by the guide groove 80 of the frame 8A and is movable in a direction parallel to the screw shaft 60. In the toggle link mechanism 7A, the drive shaft 70A is connected to the nut portion 61 by the transmission member 75, and the ball screw mechanism 6 linearly moves in conjunction with the nut portion 61 in which the rotation operation of the motor 5 is converted into a linear operation.

  The first movable blade 2A and the second movable blade 3A are opened and closed by a rotation operation about the shaft 4A, and the blade arm 21A of the first movable blade 2A and the blade arm 31A of the second movable blade 3A are opened and closed. It closes by turning in the opening direction.

  In the toggle link mechanism 7A, the first link 71A and the second link 72A, which are bent at the connection portion by the drive shaft 70A, are operated so that the first movable blade 2A and the second movable blade 3A are closed. In conjunction with this, the drive shaft 70A that moves linearly rotates around the fulcrum in the direction in which the angle between the first link 71A and the second link 72A opens. Then, when the first movable blade 2A and the second movable blade 3A are closed, the dimensions and angles of the respective parts are determined so that the angle formed by the first link 71A and the second link 72A approaches 180 °. . If the angle formed by the first link 71A and the second link 72A exceeds 180 °, the first movable blade 2A and the second movable blade 3A rotate in the opening direction, so the first link 71A. And the second link 72A are configured so that the angle does not exceed 180 °.

  The electric scissors 1A includes an operation unit 10 that opens and closes the first movable blade 2A and the second movable blade 3A. The operation unit 10 includes a sub-trigger 12 that operates in conjunction with a first switch 11 that switches on and off the power supplied to the motor 5, and a second switch 13 that controls the rotation direction, rotation amount, and rotation speed of the motor 5. The main trigger 14 interlocking with is provided.

  The sub trigger 12 is attached to the housing 9 so as to be rotatable about a shaft 12a, and includes a regulation protrusion 12b that regulates the operation of the main trigger 14. The main trigger 14 is attached to the shaft 13 a of the second switch 13. When the shaft 13a rotates by operating the main trigger 14, the second switch 13 outputs a control signal corresponding to the rotation direction, the rotation amount, and the rotation speed, and the motor 5 is synchronized with the movement of the main trigger 14. Be controlled.

  In the electric scissors 1A, when the sub-trigger 12 is not operated and the first switch 11 is off, the restricting projection 12b is locked to the main trigger 14, and the operation of the main trigger 14 is restricted.

  When the sub trigger 12 is operated to displace the sub trigger 12 to a position where the first switch 11 is turned on, the power is turned on and the regulating projection 12b is detached from the main trigger 14. Thereby, the main trigger 14 can be operated. When the main trigger 14 is operated while the sub trigger 12 is operated, a control signal corresponding to the rotation direction, rotation amount, and rotation speed of the main trigger 14 is output by the second switch 13, and the movement of the main trigger 14. Accordingly, the motor 5 is controlled.

<Operation example of the electric scissors of the first embodiment>
Next, the operation of the electric scissors 1A according to the first embodiment will be described with reference to the drawings. The user holds the housing 9 and operates the sub trigger 12 to displace the sub trigger 12 to a position where the first switch 11 is turned on. As a result, in the electric scissors 1A, the power is turned on, and the restricting projection 12b is detached from the main trigger 14, so that the main trigger 14 can be operated.

  The user operates the main trigger 14 while operating the sub trigger 12. In the electric scissors 1A, a control signal corresponding to the rotation direction, rotation amount, and rotation speed of the main trigger 14 is output by the second switch 13, and the motor 5 is controlled in accordance with the movement of the main trigger 14.

  When the electric scissors 1A are displaced in the direction of gripping the main trigger 14, the first movable blade 2A and the second movable blade 3A are closed, and when the main trigger 14 is moved away, the first movable blade 2A The motor 5 is controlled in the direction in which the second movable blade 3A is opened.

  When the motor 5 is rotationally driven in the direction in which the first movable blade 2A and the second movable blade 3A are closed, the nut portion 61 linearly moves in the direction of the arrow F1 according to the rotational direction of the screw shaft 60.

  When the motor 5 is rotationally driven in a predetermined direction and the nut portion 61 moves linearly in the direction of the arrow F1, the drive shaft 70A of the toggle link mechanism 7A connected by the nut portion 61 and the transmission member 75 is moved to the first movable blade 2A. And linearly moves in the direction of arrow F1, which is a direction approaching the axis 4A of the second movable blade 3A.

  In the toggle link mechanism 7A, the displacement due to the linear movement of the drive shaft 70A is transmitted to the first movable blade 2A by the first link 71A and also transmitted to the second movable blade 3A by the second link 72A. .

  As shown in FIG. 1, when the drive shaft 70A of the toggle link mechanism 7A moves linearly in the direction of arrow F1 from the state in which the first movable blade 2A and the second movable blade 3A are opened, the connecting portion by the drive shaft 70A The bent first link 71A and second link 72A rotate in a direction in which an angle formed by the first link 71A and the second link 72A opens with the driving shaft 70A moving linearly as a fulcrum. To do.

  The first movable blade 2A, in which the first link 71A is connected to the blade arm 21A, and the second movable blade 3A, in which the second link 72A is connected to the blade arm 31A, have the shaft 4A as a fulcrum, and the blade The angle formed by the arm 21A and the blade arm 31A rotates in the opening direction. When the angle between the blade arm 21A and the blade arm 31A is rotated in the opening direction, the first movable blade 2A and the second movable blade 3A are closed.

  When the first movable blade 2A and the second movable blade 3A are closed, the angle formed by the first link 71A and the second link 72A approaches 180 °. In the toggle link mechanism 7A, when the first movable blade 2A and the second movable blade 3A are closed, the angle formed by the first link 71A and the second link 72A approaches 180 °. The link 71 </ b> A and the second link 72 </ b> A approach the form of being aligned on a straight line.

  Accordingly, the first movable blade 2A and the second movable blade as shown in FIG. 2 are compared with the first closed state of the first movable blade 2A and the second movable blade 3A as shown in FIG. The cutting force generated by the blade forming portion 20A of the first movable blade 2A and the blade forming portion 30A of the second movable blade 3A increases when 3A is closed.

  When the motor 5 is rotationally driven in the direction in which the first movable blade 2A and the second movable blade 3A are opened, the nut portion 61 linearly moves in the direction of the arrow F2 in accordance with the rotational direction of the screw shaft 60.

  When the motor 5 is rotationally driven in a predetermined reverse direction and the nut portion 61 moves linearly in the direction of the arrow F2, the drive shaft 70A of the toggle link mechanism 7A is moved to the shaft 4A of the first movable blade 2A and the second movable blade 3A. Move linearly in the direction of arrow F2, which is the direction away from the direction.

  As shown in FIG. 2, when the drive shaft 70A of the toggle link mechanism 7A moves linearly in the direction of the arrow F2 from the state in which the first movable blade 2A and the second movable blade 3A are closed, the first link 71A and the first link 71A The second link 72A rotates in the direction in which the angle formed by the first link 71A and the second link 72A closes with the drive shaft 70A moving linearly as a fulcrum.

  The first movable blade 2A in which the first link 71A is connected to the blade arm 21A and the second movable blade 3A in which the second link 72A is connected to the blade arm 31A are arranged with the shaft 4A as a fulcrum. The angle formed by the arm 21A and the blade arm 31A rotates in the closing direction. When the angle formed by the blade arm 21A and the blade arm 31A rotates in the closing direction, the first movable blade 2A and the second movable blade 3A are opened.

  Next, the exchange operation of the blade forming portion in the first movable blade 2A and the second movable blade 3A will be described. When exchanging the blade forming portions of the first movable blade 2A and the second movable blade 3A, first, the screw 44A is loosened and removed from the shaft portion 43A. When the screw 44A has a hexagonal head, the screw 44A can be attached and detached with a hexagon wrench.

  The screw 44A is removed from the shaft portion 43A, the washer 45A and the O-ring 46A are removed from the shaft portion 43A, and the shaft portion 43A is connected to the bearing holes 42b of the first mounting bracket 40A and the second mounting bracket 41A and the first movable member. The blade 2A and the second movable blade 3A are extracted from the bearing holes. Then, the screw 42d is removed, and the bearing portion 42c is removed from the first mounting bracket 40A.

  As a result, the first movable blade 2A can move the blade forming portion 20A and the blade arm 21A in the thickness direction along the axis, and a pin (not shown) formed on the blade arm 21A is formed on the blade forming portion 20A. The blade forming portion 20A can be removed by pulling out from the hole 24A. Further, in the second movable blade 3A, the blade forming portion 30A and the blade arm 31A can move in the thickness direction along the axis, and the pin 34A formed on the blade arm 31A is inserted into the hole formed in the blade forming portion 30A. The blade forming part 30A can be removed by removing from the part 35A.

  When attaching the blade forming portion, a hole 24A formed in the blade forming portion 20A is inserted into a pin (not shown) formed in the blade arm 21A, and the bearing hole 22A of the blade forming portion 20A and the bearing of the blade arm 21A are inserted. The blade forming part 20A and the blade arm 21A are integrated by overlapping the positions of the holes 23A.

  Further, the hole 35A formed in the blade forming portion 30A is inserted into the pin 34A formed in the blade arm 31A, and the positions of the bearing hole 32A of the blade forming portion 30A and the bearing hole 33A of the blade arm 31A are aligned. The blade forming part 30A and the blade arm 31A are integrated together.

  When a blade forming portion is attached to each blade arm, washers 42e are respectively inserted between the first movable blade 2A and the first mounting bracket 40A and between the second movable blade 3A and the second mounting bracket 41A. The bearing portion 42c is attached to the first mounting bracket 40A and fixed with screws 42d.

  When the bearing portion 42c is fixed to the first mounting bracket 40A, the movement of each movable blade in the thickness direction is restricted, and the first movable blade 2A and the second movable blade 3A are overlapped with the positions of the bearing holes aligned. Then, the shaft portion 43A is inserted into the bearing holes 42b of the first mounting bracket 40A and the second mounting bracket 41A and the bearing holes of the first movable blade 2A and the second movable blade 3A.

  When the shaft portion 43A is inserted into the bearing holes 42b of the first mounting bracket 40A and the second mounting bracket 41A and the bearing holes of the first movable blade 2A and the second movable blade 3A, the flange portion 47a is While being in contact with the first mounting bracket 40A, the washer receiving portion 47b protrudes from the second mounting bracket 41A.

  The washer 45A and the O-ring 46A are fitted into the washer receiving portion 47b of the shaft portion 43A protruding from the second mounting bracket 41A, and the screw 44A is fastened to the screw portion 47c of the shaft portion 43A.

  When the screw 44A is fastened until the washer 45A comes into contact with the stepped portion of the washer receiving portion 47b, the screw 44A cannot be tightened any further. The washer 45A is sandwiched between the flange portion 47d of the screw 44A and the stepped portion of the washer receiving portion 47b, and movement in the axial direction is restricted.

  On the other hand, when the screw 44A is fastened until the washer 45A comes into contact with the stepped portion of the washer receiving portion 47b, the O-ring 46A is crushed between the second mounting bracket 41A and the washer 45A. The first movable blade 2A and the second movable blade 3A between the first mounting bracket 40A and the second mounting bracket 41A are along the axis by the elastic force generated by the O-ring 46A being crushed. Pressed in the direction.

  Accordingly, the screw 44A is fastened until the washer 45A comes into contact with the stepped portion of the washer receiving portion 47b, so that the space between the blade forming portion 20A of the first movable blade 2A and the blade forming portion 30A of the second movable blade 3A. Thus, it is assembled in a state where no play occurs.

  Thus, the user or the like only needs to fasten the screw 44A until the washer 45A contacts the stepped portion of the washer receiving portion 47b, and does not need to adjust the tightening force of the screw 44A. Since the first movable blade 2A and the second movable blade 3A are pressed in the thickness direction by the elastic force of the O-ring 46A, the good movement of the first movable blade 2A and the second movable blade 3A is good. It is possible to cope with a change in thickness due to tolerance accumulation in the thickness direction of each part without being damaged. Therefore, even when the blade forming portion is exchanged, the desired cutting performance can be obtained without adjusting the tightening force of the screw or the like.

  Further, the shaft 4A has a flange portion 47a of the shaft portion 43A in contact with the first mounting bracket 40A, and a washer 45A is in contact with the second mounting bracket 41A through an O-ring 46A, both of which are movable blades that rotate. Not in direct contact with. As a result, the screws 44A can be prevented from loosening without providing a locking stopper, and the desired cutting performance can be continuously obtained.

  FIG. 6 is a cross-sectional view showing a modification of the blade attachment structure in the first embodiment. In the modification shown in FIG. 6, a spring spring 46B is provided as an elastic member. A washer 45B, which is an example of a pressing member, is provided with a step portion to which the spring 46B is attached between the second attachment fitting 41A. The other configuration is the same as the blade mounting structure in the first embodiment. Note that the number of the spring springs 46B is not limited to one and may be a plurality.

<Configuration example of the electric scissors of the second embodiment>
7 and 8 are side sectional views showing an example of the configuration of the electric scissors according to the second embodiment. FIG. 7 shows a state in which the blade is opened, and FIG. 8 shows a state in which the blade is closed. . 7 and 8, a mechanism for driving the blade in the electric scissors is shown, and the casing, the operation unit, and the like are not shown.

  The electric scissors 1B of the second embodiment have a movable blade 2B and a fixed blade 3B, and the movable blade 2B is supported rotatably about the shaft 4B.

  In the electric scissors 1B, the rotation operation of the motor 5 is converted into a linear operation by the ball screw mechanism 6, and the driving force of the motor 5 converted into the linear operation is transmitted to the movable blade 2B by the toggle link mechanism 7B. 2B is opened and closed by a rotation operation with the shaft 4B as a fulcrum.

  Details of each component will be described below. The movable blade 2B is an example of a first blade portion. The movable blade 2B is provided with a blade forming portion 20B on one side across the support position by the shaft 4B, and the angle formed with the blade forming portion 20B on the other side is a predetermined obtuse angle. A blade arm 21B is provided as a transmission portion to be formed. In the movable blade 2B, the blade forming portion 20B and the blade arm 21B are integrated.

  The fixed blade 3B is an example of a second blade portion, and includes a blade forming portion 30B and a blade arm 31B as a transmission portion. In the fixed blade 3B, the blade forming portion 30B and the blade arm 31B are integrated.

  FIG. 9 is a cross-sectional view showing a second embodiment of the blade mounting structure. The shaft 4B includes a shaft portion 43B inserted into the bearing hole 22B of the movable blade 2B and a bearing hole 32B of the fixed blade 3B, a screw 44B fastened to the shaft portion 43B, and the movable blade 2B and the fixed blade 3B in the axial direction. A washer 45C and an O-ring 46C to be pressed and a spacer 45D are provided.

  The shaft portion 43B has a cylindrical shape having a diameter inserted into the bearing hole 22B of the movable blade 2B and the bearing hole 32B of the fixed blade 3B, and a flange portion 47e is formed on the outer periphery of one end portion. The flange portion 47e is in contact with a spacer 45D having a tapered cross section and a tapered cross section. The spacer 45D is made of, for example, a resin material having a low friction coefficient.

  The shaft portion 43B is provided with a step whose diameter decreases on the outer periphery of the other end portion, and a washer receiving portion 47f to which the washer 45C is attached is formed. Further, the shaft portion 43B is formed with a screw portion 47g to which the screw 44B is fastened on the inner periphery of the other end portion.

  The shaft portion 43B is configured such that the length from the flange portion 47e to the step portion of the washer receiving portion 47f is slightly longer than the thickness in which the movable blade 2B and the fixed blade 3B are overlapped.

  The screw 44B is an example of a fastening member, and a flange portion 47h that presses the washer 45C is formed. The washer 45C is an example of a pressing member, and is configured to be slightly thicker than the length of the washer receiving portion 47f of the shaft portion 43B. In addition, the washer 45C has a structure in which an annular groove is formed on the surface facing the fixed blade 3B to prevent the O-ring 46C from being displaced.

  The O-ring 46C is an example of an elastic member, and is inserted between the washer 45C and the fixed blade 3B.

  In the shaft portion 43B inserted into the bearing hole 22B of the movable blade 2B and the bearing hole 32B of the fixed blade 3B, the spacer 45D contacts the movable blade 2B, and the washer receiving portion 47f protrudes from the fixed blade 3B.

  A washer 45C fitted to the washer receiving portion 47f of the shaft portion 43B protruding from the fixed blade 3B is formed between the flange portion 47h of the screw 44B fastened to the screw portion 47g of the shaft portion 43B and the step portion of the washer receiving portion 47f. Sandwiched between them.

  The washer 45C is configured to be slightly thicker than the length of the washer receiving portion 47f of the shaft portion 43B. When the screw 44B is fastened until the washer 45C contacts the stepped portion of the washer receiving portion 47f, the flange portion 47h of the screw 44B, A gap is formed between the end of the washer receiving portion 47f of the shaft portion 43B.

  Thus, when the screw 44B is fastened until the washer 45C comes into contact with the stepped portion of the washer receiving portion 47f, the screw 44B cannot be tightened any further. The washer 45C is sandwiched between the flange portion 47h of the screw 44B and the step portion of the washer receiving portion 47f, and movement in the axial direction is restricted.

  On the other hand, the shaft portion 43B is configured such that the length from the flange portion 47e to the step portion of the washer receiving portion 47f is slightly longer than the thickness of the movable blade 2B and the fixed blade 3B overlapped. There is a gap between 45C.

  In the washer 45C, an O-ring 46C is inserted into an annular groove formed on a surface facing the fixed blade 3B. The O-ring 46C protrudes from the surface facing the fixed blade 3B of the washer 45C. The protruding amount of the O-ring 46C is configured to be larger than the gap between the fixed blade 3B and the washer 45C.

  Thus, when the screw 44B is fastened until the washer 45C contacts the stepped portion of the washer receiving portion 47f, the O-ring 46C is crushed between the fixed blade 3B and the washer 45C. The movable blade 2B and the fixed blade 3B are pressed in the direction along the axis by the elastic force generated by the O-ring 46C being crushed. When the screw 44B is fastened until the washer 45C comes into contact with the step portion of the washer receiving portion 47f, the spacer 45D is elastically deformed in a direction in which the diameter increases due to the tapered shape with the flange portion 47e.

  Accordingly, by tightening the screw 44B until the washer 45C comes into contact with the stepped portion of the washer receiving portion 47f, there is no backlash between the movable blade 2B and the fixed blade 3B without adjusting the tightening force of the screw 44B. Assembled in state.

  On the other hand, the movable blade 2B is configured to be exchangeable by attaching and detaching the shaft 4B by removing the screw 44B.

  Returning to FIGS. 7 and 8, the motor 5 is connected to a reduction gear 50 whose drive shaft uses, for example, a planetary gear. In the ball screw mechanism 6, a screw shaft 60 connected to the output shaft of the speed reducer 50 and a ball (not shown) inserted in a screw groove of the screw shaft 60 are incorporated, and when the screw shaft 60 is driven to rotate, The nut part 61 which moves linearly along is provided.

  In the ball screw mechanism 6, the rotation operation of the motor 5 is converted into the linear operation of the nut portion 61, and the moving direction of the nut portion 61 is switched according to the rotation direction of the motor 5.

  The toggle link mechanism 7B includes a first link 71B and a second link 72B that are rotatably connected by a drive shaft 70B. In the toggle link mechanism 7B, one end of the first link 71B and the blade arm 21B of the movable blade 2B are rotatably connected with a shaft 73B as a fulcrum. Further, one end of the second link 72B and the blade arm 31B of the fixed blade 3B are rotatably connected with the shaft 74B as a fulcrum. Further, the other end portion of the first link 71B and the other end portion of the second link 72B are rotatably connected with the drive shaft 70B as a fulcrum.

  In the toggle link mechanism 7B, the drive shaft 70B is connected to the nut portion 61 by the transmission member 75, and the ball screw mechanism 6 linearly moves in conjunction with the nut portion 61 in which the rotation operation of the motor 5 is converted into a linear operation.

  The movable blade 2B opens and closes with respect to the fixed blade 3B by a rotation operation with the shaft 4B as a fulcrum, and the angle formed by the blade arm 21B of the movable blade 2B and the blade arm 31B of the fixed blade 3B rotates in the opening direction. close.

  The toggle link mechanism 7B includes a drive shaft 70B in which the first link 71B and the second link 72B, which are bent at the connecting portion of the drive shaft 70B, move linearly in conjunction with the operation of closing the movable blade 2B. Is rotated in the direction in which the angle formed by the first link 71B and the second link 72B is opened. Then, when the movable blade 2B is closed, the dimensions and angles of the respective parts are determined so that the angle formed by the first link 71B and the second link 72B approaches 180 °.

<Operation example of electric scissors of the second embodiment>
Next, the operation of the electric scissors 1B according to the second embodiment will be described with reference to the drawings. When the motor 5 is rotationally driven in the direction in which the movable blade 2B is closed, the nut portion 61 linearly moves in the direction of the arrow F1 according to the rotational direction of the screw shaft 60.

  When the motor 5 is rotationally driven in a predetermined direction and the nut portion 61 moves linearly in the direction of the arrow F1, the drive shaft 70B of the toggle link mechanism 7B connected to the nut portion 61 and the transmission member 75 is moved to the shaft 4B of the movable blade 2B. Move straight in the direction approaching. In the toggle link mechanism 7B, the displacement due to the linear movement of the drive shaft 70B is transmitted to the movable blade 2B by the first link 71B.

  As shown in FIG. 7, when the drive shaft 70B of the toggle link mechanism 7B moves linearly from the state in which the movable blade 2B is opened, the first link 71B and the first link 71B which are bent at the connecting portion by the drive shaft 70B The second link 72B rotates in a direction in which the angle formed by the first link 71B and the second link 72B opens with the drive shaft 70B moving linearly as a fulcrum.

  The movable blade 2B, in which the first link 71B is connected to the blade arm 21B, rotates in the direction in which the angle formed by the blade arm 21B and the blade arm 31B opens with the shaft 4B as a fulcrum. When the angle formed by the blade arm 21B and the blade arm 31B rotates in the opening direction, the movable blade 2B is closed with respect to the fixed blade 3B.

  When the movable blade 2B is closed, the angle formed by the first link 71B and the second link 72B approaches 180 °. In the toggle link mechanism 7B, when the movable blade 2B is closed, the angle formed by the first link 71B and the second link 72B approaches 180 °, so that the first link 71B and the second link 72B are It approaches a form that is aligned on a straight line.

  Accordingly, the blade forming portion 20B and the fixed blade of the movable blade 2B are more closed when the movable blade 2B is closed as shown in FIG. 8 than when the movable blade 2B is started to close as shown in FIG. The cutting force generated by the 3B blade forming portion 30B increases.

  When the motor 5 is rotationally driven in the direction in which the movable blade 2B opens, the nut portion 61 linearly moves in the direction of the arrow F2 according to the rotational direction of the screw shaft 60.

  When the motor 5 is rotationally driven in a predetermined reverse direction and the nut portion 61 moves linearly in the direction of the arrow F2, the drive shaft 70B of the toggle link mechanism 7B connected by the nut portion 61 and the transmission member 75 becomes the axis of the movable blade 2B. Move linearly away from 4B.

  As shown in FIG. 8, when the drive shaft 70B of the toggle link mechanism 7B moves linearly from the state where the movable blade 2B is closed, the first link 71B and the first link 71B which are bent at the connecting portion by the drive shaft 70B The second link 72B rotates in the direction in which the angle formed by the first link 71B and the second link 72B closes with the drive shaft 70B moving linearly as a fulcrum.

  The movable blade 2B, in which the first link 71B is connected to the blade arm 21B, rotates in a direction in which the angle formed by the blade arm 21B and the blade arm 31B closes with the shaft 4B as a fulcrum. When the angle formed by the blade arm 21B and the blade arm 31B rotates in the closing direction, the movable blade 2B opens with respect to the fixed blade 3B.

  The present invention is applied to a cutting tool having a rotating shaft of a blade portion, such as electric scissors in which the blade portion is driven by a motor, or scissors manually opening and closing the blade portion. In particular, it is suitable for scissors in which the blade part can be replaced or the blade edge is sharpened.

  1A, 1B ... electric scissors, 2A ... first movable blade, 2B ... movable blade, 3A ... second movable blade, 3B ... fixed blade, 4A, 4B ... axis , 40A, first mounting bracket, 41A, second mounting bracket, 43A, 43B, shaft, 44A, 44B, screw, 45A, 45B, 45C, washer, 46A, 46C ... O-ring, 46B ... Belleville spring, 5 ... Motor, 6 ... Ball screw mechanism, 7A, 7B ... Toggle link mechanism, 70A, 70B ... Drive shaft, 71A, 71B ..First link, 72A, 72B ... second link

Claims (4)

A first blade portion rotatably supported on a shaft as a fulcrum;
A second blade portion that sandwiches the object to be cut by the rotational movement of the first blade portion with the shaft as a fulcrum,
The axis is
A shaft portion inserted into a bearing hole formed in the first blade portion and the second blade portion;
A pressing member attached to a receiving portion formed at an end portion of the shaft portion, the position of the axial direction being regulated by the receiving portion;
Fastened to the end portion of the shaft portion, presses the pressing member attached to the receiving portion along the axial direction, and is tightened until the axial position of the pressing member is regulated by the receiving portion. A fastening member
When the fastening member is fastened to the shaft portion, the fastening member is pressed by the pressing member whose position in the axial direction is regulated by the receiving portion, and the first blade portion and the second blade portion are moved in the thickness direction. A cutting tool comprising: an elastic member for pressing. The second blade portion is supported rotatably about the shaft as a fulcrum,
The cutting tool according to claim 1, wherein the first blade portion and the second blade portion are attached between a first attachment fitting and a second attachment fitting that support the shaft portion. The first blade portion and the second blade portion each have a blade forming portion and a transmission portion, and the blade is formed by attaching and detaching the shaft portion, the first mounting bracket, or the second mounting bracket. The cutting tool according to claim 2, wherein the forming part is separated from the transmission part. The cutting tool according to claim 1, wherein the elastic member includes an O-ring.

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