JP2010252853A - Seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a seat which permits durability to be improved and the posture of a frame for a seatback to be well-maintained. <P>SOLUTION: The seat has first friction portions 42 and 22c connecting the frame 2 for the seatback with the frame 1 for a seat cushion swingably around a horizontal shaft core X1 and provided in the frame 2 for the seatback, a pair of second friction portions 50 provided in the frame 1 for the seat cushion, a switch operating portion 43 capable of operating the second friction portions 50, and an operating lever 41 capable of operating the switch operating portion 43. The sandwiching of the first friction portions 42 and 22c between the second friction portions 50 permits the frame 2 for the seatback to be held at required angles. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a seat in which a seat back frame is swingably connected to a seat cushion frame around a horizontal axis.

  In general, as a seat that can adjust the posture of the seat back frame, for example, one engagement engagement portion having a number of pawls is provided on the seat back frame, and the reclining adjustment lever is attached to the seat cushion frame so as to be swingable. When the other engaging engagement part having a number of claws is provided at the end opposite to the grip part of the reclining adjustment lever, and the reclining adjustment lever is operated to one side, the engaging engagement between these engaging engagement parts Is released so that the posture of the seatback frame can be adjusted, and when the reclining adjustment lever is operated to the other side, the meshing engagement portions are engaged with each other so that the posture of the seatback frame is maintained. There is something to configure.

  As described above, when the meshing engagement portions are engaged with each other to maintain the posture of the seatback frame, the posture of the seatback frame may not be maintained in an appropriate posture. In other words, since the pitch of the claw portion of the meshing engagement portion is the minimum unit for changing the posture, the posture of the seat back frame cannot be adjusted within a range smaller than the minimum unit. It may not be possible to maintain the posture.

  Therefore, in order to avoid the above inconvenience, it can be considered that the posture of the seat back frame is adjusted steplessly by the frictional action of the friction portion provided on the seat cushion frame and the friction portion provided on the seat back frame.

  For example, in Patent Document 1, the seatback frame 18 is provided with a seatback rotation shaft 18, and the seat cushion frame is provided with two shafts 24 and 26 parallel to the seatback rotation shaft 18. 26, a pair of eccentric roller-shaped stoppers 28, 30 are rotatably attached, and a coil spring 32 is provided for abutting the pair of stoppers 28, 30 against the seat back rotating shaft 18, and the pair of stoppers 28, There are described wires 40 and 42 for separating 30 from the seat back rotating shaft 18 and a reclining adjustment lever for pulling the wires 40 and 42.

  When the reclining adjustment lever is operated, the wires 40 and 42 move away from each other, and one stopper 30 moves away from the seat back rotating shaft 18 while rotating counterclockwise against the urging force of the coil spring 32. The other stopper 28 moves away from the seat back rotating shaft 18 while rotating in the clockwise direction. As a result, the posture of the seat back frame can be adjusted.

  After adjusting the posture of the seat back frame to an appropriate posture, the operation of the reclining adjustment lever is stopped. At this time, one stopper 30 contacts the seat back rotating shaft 18 while rotating clockwise by the biasing force of the coil spring 32, and the other stopper 28 contacts the seat back rotating shaft 18 while rotating counterclockwise. .

  In this state, when a force is applied to the seat back frame and the seat back frame swings to one side, and the seat back rotating shaft 18 tries to rotate counterclockwise, the seat back rotating shaft 18 and one stopper 30 are rotated. One stopper 30 rotates in the clockwise direction due to the frictional force between the stopper 30 and the contact portion 30C of the one stopper 30 moves to the side where the distance between the contact portion 30C and the shaft 26 increases, and the one stopper 30 moves. Since the seat back rotating shaft 18 is pressed in the radial direction, further rotation of the seat back rotating shaft 18 is prevented.

  Further, when the seat back frame swings to the other side and the seat back rotating shaft attempts to rotate clockwise, the other stopper 28 presses the seat back rotating shaft 18 in the radial direction, and the seat back rotating shaft 18 Prevent further rotation of the. In this manner, the posture of the seat back frame can be maintained in an appropriate posture (note that the above-mentioned reference numerals correspond to those in Patent Document 1).

JP 2000-300371 A

  In the conventional seat, when the operation of the reclining adjustment lever is stopped, the stoppers 28 and 30 press the seat back rotating shaft 18 in the radial direction. For this reason, a radial force is applied to the seat back rotating shaft 18, and the durability of the seat back rotating shaft 18 may be reduced by using the seat for a long period of time.

  Further, when the shafts 24 and 26 and the seat back rotating shaft 18 are inclined from the parallel state due to an attachment error or the like, the stoppers 28 and 30 are inclined and contacted with the seat back rotating shaft 18. There may be a portion where 30 does not sufficiently contact the seat back rotating shaft 18. For this reason, there is a possibility that slip may occur between the stoppers 28 and 30 and the seat back rotating shaft 18 (the reference numerals are the corresponding parts of Patent Document 1).

  An object of the present invention is to provide a seat capable of improving durability and maintaining a good posture of a seat back frame.

  A first characteristic configuration of the seat of the present invention includes a first friction portion provided in the seat back frame, wherein the seat back frame is connected to the seat cushion frame so as to be swingable around a horizontal axis, A pair of second friction parts provided on the seat cushion frame and disposed on both sides of the first friction part, and a switching operation part capable of operating and holding the second friction part on the clamping side of the first friction part And an operation lever capable of operating the switching operation unit by being manually operated, and the first friction unit is clamped by the second friction unit via the switching operation unit by the operation lever. Thus, the seat back frame can be held at a desired angle with respect to the seat cushion frame.

  According to this configuration, since the pair of second friction parts are operated to the first friction part to sandwich the first friction part, one second friction part presses the first friction part. The force generated sometimes is opposite to the force generated when the other second friction portion presses the first friction portion, and the force of the pair of second friction portions cancels each other. The force of the part does not act on the seat back frame. Thereby, durability of a sheet | seat can be improved.

  In addition, since the pair of second friction parts are operated to the first friction part to sandwich the first friction part, the contact surface of the second friction part and the contact surface of the first friction part are in a parallel state. Even if the pair of second friction parts is operated to the clamping side of the first friction part, the contact surface of the second friction part and the contact surface of the first friction part become parallel to each other. The contact surface of 2 friction parts contacts the contact surface of a 1st friction part reliably. Thereby, the attitude | position of the frame for seat backs can be favorably maintained, without producing a slip between a 2nd friction part and a 1st friction part.

  According to a second characteristic configuration of the present invention, the operation lever and the switching operation unit are swingably supported on the seat cushion frame, and a pressing unit provided on the operation lever contacts the switching operation unit and pushes it. By operating, the second friction part is configured to be operated to the clamping side of the first friction part, and at the contact point between the pressing part and the switching operation part, and the swing fulcrum of the operation lever, A virtual straight line passing through the contact point and the swing fulcrum is set, and the virtual straight line is switched in the clamping state in which the first friction part is clamped by the second friction part via the switching operation part by the operation lever. The operation unit is configured to be substantially orthogonal.

  For example, as shown in FIG. 11, by operating the operation lever 41, the pressing portion 45 b comes into contact with the switching operation portion 43 and pushes the switching operation portion 43. At this time, the second friction part is operated to the clamping side of the first friction part, and the first friction part is clamped by the second friction part, and the contact point P of the operation lever 41 and the swing fulcrum X5 are The virtual straight line L1 passing through and the switching operation unit 43 are substantially orthogonal, in other words, the virtual straight line L1 is along the direction of the normal L2 of the switching operation unit 43. In such a posture of the operation lever 41, the vertical drag N acting on the pressing portion 45b acts on the swing fulcrum X5, and the operation lever 41 maintains its posture. As described above, the clamped state of the second friction portion can be maintained by a simple operation of operating the operation lever 41 so that the virtual straight line L1 and the switching operation portion 43 are substantially orthogonal to each other without a special lock mechanism.

  The third characteristic configuration of the present invention includes the seat cushion frame, the seat back frame, an armrest frame rotatably connected to the seat back frame and supporting an armrest, the armrest frame and the seat cushion. A four-point link mechanism configured to maintain a use posture of the armrest.

  According to this configuration, the seat cushion frame, the seat back frame, the armrest frame, and the connecting link constitute a four-point link mechanism. For example, as shown in FIG. Even if the posture is changed, the posture of the armrest frame 3 that supports the armrest 31 does not change. For this reason, it is possible to maintain the use posture of the armrest 31 regardless of the posture of the seat back frame 2 and to prevent the driver from feeling uncomfortable.

  According to a fourth characteristic configuration of the present invention, the seat cushion frame removably supports the seat cushion, and the seat back frame removably supports the seat back.

  According to this configuration, since the seat cushion and the seat back can be changed, the seat cushion and the seat back can be replaced with another seat cushion and the seat back without changing each frame as a base of the seat. Thus, variations of the sheet can be increased without causing an increase in cost.

It is a side view which shows the state which attached the reclining seat to the driving | running part of the tractor. It is a side view which shows a reclining seat. It is a side view which shows a slide mechanism and a cushion adjustment mechanism. It is a front view which shows a slide mechanism and a cushion adjustment mechanism. It is a top view which shows a slide mechanism and a cushion adjustment mechanism. It is a perspective view which shows a reclining seat. It is a side view which shows an attitude | position adjustment mechanism. It is a longitudinal cross-sectional view which shows an attitude | position adjustment mechanism. It is a figure which shows each state of a switching operation part. It is a disassembled perspective view which shows a switching operation part. It is a figure which shows an operation lever and a rocking | swiveling member. It is a figure which shows an operation lever and a rocking | swiveling member.

[Overall structure of tractor]
As shown in FIG. 1, the tractor (an example of a work vehicle) includes a front wheel 13 configured to be steerable and drivable, and a pair of left and right drivable wheels 14. The front part of the airframe is provided with an engine 15 and the like, and the rear part of the airframe is provided with a steering handle 16, a driving part 17, a lops frame 18 and the like. And the reclining seat which concerns on this invention is equipped in the operation part 17. FIG.

[Composition of reclining seat]
As shown in FIGS. 2 and 6 to 8, the reclining seat includes a seat cushion frame 1 and a seat back frame 2 connected to the seat cushion frame 1 so as to be swingable about a horizontal axis X1. An armrest frame 3 rotatably connected to the seatback frame 2 about the horizontal axis X4; a connecting link 4 rotatably connecting the armrest frame 3 and the seat cushion frame 1; A seat cushion 5 detachably supported on the cushion frame 1, a seat back 6 detachably supported on the seat back frame 2, and supported on the armrest frame 3 so as to be swingable about the horizontal axis X 10. Armrest 31.

(Frame 1 for seat cushion)
As shown in FIGS. 2 and 6 to 8, the seat cushion frame 1 is formed to be a long and plate-like first support member 7 and bend on both lateral sides of the first support member 7. A plate-like second support member 8 having a parallelogram shape. The first support member 7 is provided with bolt insertion holes 11 on the front, rear, left and right. The second support member 8 is provided with a first projecting pin 10 and a second projecting pin 12.

  A rectangular plate-shaped sheet metal mounting member 9 is attached to the lower surface of the seat cushion 5. The bolt is fastened to the mounting member 9 through the bolt insertion hole 11. The mounting member 9 (seat cushion 5) is attached to the first support member 7 (seat cushion frame 1) by fastening the bolt, and the mounting member 9 (seat cushion 5) is attached to the first support member by removing the bolt. 7 (seat cushion frame 1).

(Frame 2 for seat back)
As shown in FIGS. 2 and 6 to 8, the seat back frame 2 is formed by bending a long and plate-like third support member 21 and both lateral sides of the third support member 21. A plate-like fourth support member 22. Bolt insertion holes 27 are formed in the third support member 21 vertically and horizontally. The fourth support member 22 has a rectangular plate-shaped arm portion 22a, a flange portion 22b provided on the long side portion of the arm portion 22a, and a base end side (side of the horizontal axis X1) of the arm portion 22a. And a provided disc portion 22c.

  A cutout 23 is provided on the outer peripheral portion of the disc portion 22c. Between the side surface 23a of the notch 23 and the first projecting pin 10, there is provided an engagement space that allows the seat back frame 2 to swing within a predetermined range. Thereby, it is possible to prevent the seat back frame 2 from being moved forward or backward more than necessary.

  A connecting bolt 24 (an example of a seat back rotating shaft) that penetrates the disk portion 22c and the second support member 8 is provided. A cylindrical ring member 26 is provided between the disc portion 22 c and the second support member 8. A torsion spring 25 is wound between the head 24a of the connecting bolt 24 and the disc portion 22c. One end 25 a of the torsion spring 25 abuts on the flange portion 22 b and the other end 25 b of the torsion spring 25 abuts on the first protruding pin 10. The seat back frame 2 is urged toward the standing posture by the urging force of the torsion spring 25.

  The bolt is fastened to the seat back 6 through the bolt insertion hole 27. The seat back 6 is attached to the third support member 21 (the seat back frame 2) by fastening the bolts, and the seat back 6 is detached from the third support member 21 (the seat back frame 2) by removing the bolts. . The seat back 6 is formed with a recessed portion 28 into which the third support member 21 can be fitted.

(Armrest frame 3)
As shown in FIG. 2 and FIG. 6, the armrest frame 3 is formed by bending a trapezoidal plate so that a portion closer to the lower side from the middle part is mountain-folded on the outer surface and closer to the upper side from the middle part. The part 3 is bent so as to be valley-folded on the outer surface, and the upper part 3a spreads outward as it goes forward.

  An armrest 31 is supported on the upper portion 3a of the armrest frame 3 so as to be swingable about the horizontal axis X10 and detachable. An appropriate frictional force is set between the upper portion 3a and the armrest 31. For example, when the driver gets into the driving unit 17 and sits on the reclining seat, the armrest 31 is directed upward. At this time, since the armrest 31 maintains an upward posture by the frictional force, the driver does not need to support the armrest 31 with fingers when sitting on the reclining seat, so that the driver can easily sit on the reclining seat.

  The armrest 31 is provided with a stopper (not shown). When the armrest 31 swings downward and assumes a horizontal posture (usage posture), the armrest 31 comes into contact with the upper portion 3a and the armrest 31 exceeds that. Is configured to prevent the rocking of the motor. For example, after the driver sits on the reclining seat, the arm is placed on the armrest 31. At this time, the armrest 31 swings downward against the frictional force, and the horizontal posture of the armrest 31 is maintained by the contact between the stopper and the upper portion 3a.

  According to the above configuration, since the seat cushion 5 and the seat back 6 can be changed, the seat cushion 5 and the seat back 6 can be changed to another seat cushion 5 without changing the respective frames 1 to 3 as the base of the seat. In addition, the seat variation can be increased by replacing the seat back 6 with the seat back 6.

  Furthermore, by making each frame 1-3 into an independent frame structure, each frame 1-3 can be exchanged according to the model of the tractor, etc., and seat variations can be further increased. In particular, if the armrest frame 3 is replaced with another armrest frame 3 having a different vertical height, the height of the armrest 31 can be adjusted.

(Link 4)
As shown in FIGS. 2, 6, and 7, the connecting link 4 is formed in a long shape. The distal end side of the connecting link 4 is connected to the lower part 3b of the armrest frame 3 so as to be rotatable around the horizontal axis X3. The base end side of the connection link 4 is connected to the second support member 8 so as to be rotatable around the horizontal axis X2.

(4-point link mechanism)
As shown in FIG. 2, the seat cushion frame 1, the seat back frame 2, the armrest frame 3, and the connecting link 4 constitute a four-point link mechanism that maintains the horizontal posture of the armrest 31.

As shown by a two-dot chain line in FIG. 2, when the seat back frame 2 swings to one side, the posture of the armrest 31 maintains a horizontal posture. Further, as shown by the solid line in FIG. 2, when the seat back frame 2 swings to the other side, the posture of the armrest 31 maintains the horizontal posture.
Thus, since the horizontal posture of the armrest 31 can be maintained regardless of the posture of the seatback frame 2, when the seatback frame 2 swings, the armrest 31 moves along with the movement of the seatback frame 2. The ideal driving posture can be maintained without deviating from the horizontal posture.

  As shown in FIGS. 2 to 5, a slide mechanism 71 and a cushion adjustment mechanism 72 are arranged in a vertically arranged manner between the reclining seat and the lower frame T of the operation unit 17.

(Slide mechanism 71)
The slide mechanism 71 slides the reclining seat in the front-rear direction, and includes a slide adjustment lever 75 that can be swung laterally, a guided member 73 attached to the mounting member 9, and a guided body thereof. And a guide member 74 for guiding the member 73.

  The guided member 73 includes a rectangular plate-shaped flat plate portion 73a, a pair of rectangular plate-shaped bent portions 73b extending from both ends of the flat plate portion 73a in a direction perpendicular to the flat plate portion 73a, and the pair of folded portions. A pair of curved portions 73c that are curved inward from the respective end portions of the curved portion 73b.

  A first projecting piece 81 extending forward is attached to the upper surface of the flat plate portion 73a. A mounting member support portion 82 that supports the mounting member 9 is attached to the lower surface of the mounting member 9. The 1st protrusion piece 81 and the mounting member support part 82 are connected so that rotation around the horizontal axis X8 is possible. A second projecting piece 83 extending rearward is attached to the upper surface of the flat plate portion 73a. The second projecting piece 83 has a first contact portion 83 a that contacts the lower surface of the mounting member 9.

  Accordingly, when the rear side of the seat cushion 5 is lifted around the horizontal axis X8, the reclining seat falls forward, so that maintenance work can be easily performed.

  The guide member 74 includes a rectangular plate-like flat plate portion 74a, a pair of rectangular plate-like bent portions 74b extending from both ends of the flat plate portion 74a in a direction perpendicular to the flat plate portion 74a, and the pair of bent portions. And a pair of flange portions 74c extending outward from the respective end portions of the portion 74b. The upper surface of the flange portion 74c supports the flat plate portion 73a. The side surface of the bent portion 74b abuts on the curved portion 73c. The bent portion 74b is provided with a plurality of engagement holes 74d along the front-rear direction.

  A lever support member 84 is attached to the slide adjustment lever 75. The lever support member 84 can be rotated around the vertical axis of the guided member 73 by a lever mounting portion 84a for attaching the slide adjusting lever 75, a hook portion 84c having an engaging claw 84b engaged with the engaging hole 74d. And a connecting portion 84d connected to the connecting portion. A spring 76 is provided between the hook portion 84 c and the guided member 73.

  When the slide adjustment lever 75 is swung in the lateral direction, the lever support member 84 rotates in one direction against the biasing force of the spring 76, and the engagement claw 84 b is disengaged from the engagement hole 74 d of the guide member 74. Thereby, a reclining seat can be slid back and forth.

  When the swinging operation of the slide adjusting lever 75 is stopped, the lever support member 84 is rotated in the other direction by the biasing force of the spring 76, and the engaging claw 84b is an opening provided in the bent portion 74b and the curved portion 73c ( It engages with the engagement hole 74d through (not shown). Thereby, the reclining seat can be fixed at a desired position in the front-rear direction.

(Cushion adjustment mechanism 72)
The cushion adjusting mechanism 72 adjusts the cushion of the reclining seat, and includes a cushion adjusting lever 85 that can be rotated, a support frame 86 with a cross-sectional shape attached to the guide member 74, and a lower part. Provided between the fifth support member 87 attached to the frame T, the triangular swing link 77 connecting the fifth support member 87 and the support frame 86, and the fifth support member 87 and the swing link 77. The spring 79 is provided.

  The swing link 77 is provided on the front, rear, left, and right, and a third projecting pin 88 that projects outward is provided on the upper side of each of the swing links 77. Each of the pair of support frames 86 is provided with a pair of bearing portions 89 that pivotally support the third protruding pin 88. The third projecting pin 88 is located at a portion corresponding to the upper left corner of the three corners of the swing link 77 on the paper surface.

  The fifth support member 87 includes a lateral side wall portion 87a positioned on the left and right sides, a front side wall portion 87c positioned on the front side, and a rear side wall portion 87b positioned on the rear side, and is configured in a box shape having an upper opening. It is. A lower side of each of the swing links 77 and a lateral side wall portion 87a of the fifth support member 87 are bolted so as to be rotatable around the lateral axis X9. The bolt is located at a portion corresponding to the lower corner portion of the three corner portions of the swing link 77 on the paper surface.

  The cushion adjusting lever 85 has a male threaded portion 85a on the distal end side. A nut 94 is fastened to the front end of the male screw portion 85a through the rear side wall portion 87b. A washer 93 is provided between the rear side wall 87 b and the nut 94. In the middle of the male screw portion 85a, a columnar first rod-like member 90 that is screwed with the male screw portion 85a is provided. A second rod-shaped member 78 is stretched around the pair of swing links 77 on the front side. A pair of springs 79 is provided between the first rod-shaped member 90 and the second rod-shaped member 78.

  Due to the urging force of the spring 79, the nut 94 and the washer 93 attached to the cushion adjustment lever 85 abut against the rear side wall portion 87b to prevent the cushion adjustment lever 85 from coming off. Therefore, the cushion adjustment lever 85 is rotatably attached to the rear side wall portion 87b of the fifth support member 87.

When the driver is not sitting on the reclining seat, the urging force of the spring 79 causes the swing link 77 to abut on the fourth projecting pin 92, and when the driver is sitting on the reclining seat, the spring 79 resists the urging force of the spring 79. Thus, the swing link 77 is separated from the fourth projecting pin 92. The second rod-shaped member 78 is located at a portion corresponding to the upper right corner of the three corners of the swing link 77 on the paper surface.
Thereby, the reclining seat has a cushioning action. When the cushion adjustment lever 85 is turned, the first rod-like member 90 moves to the front and rear side, and the tension of the spring 79 changes, so that the cushioning force can be adjusted according to the driver's preference.

  The swing link 77 has a second contact portion 80 formed by bending a plate extending from the side, and when the swing link 77 swings to the other side to a predetermined angle, the second contact portion 80 is formed. Is configured to abut against the stopper 91 of the lower frame T.

[Configuration of attitude adjustment mechanism TK]
A posture adjusting mechanism TK for adjusting the posture of the reclining seat is provided across the seat cushion frame 1 and the seat back frame 2. In the present embodiment, the posture adjustment mechanism TK is illustrated as being provided on the left side of the reclining seat, but may be provided on the right side of the reclining seat, and is not particularly limited.

  As shown in FIGS. 7 to 11, the posture adjusting mechanism TK includes an operation lever 41 that can be manually operated, and a disk portion 22 c (corresponding to a first friction portion) of the fourth support member 22 of the seat back frame 2. The first friction pad 42 (corresponding to the first friction part) provided on both sides of the first and second switching pads 43 and a switching operation part 43 that holds the first friction pad 42 by operating the operation lever 41 are provided.

(Operation lever 41)
The operation lever 41 includes a shaft 44 having a grip portion and a base end side plate 45 fixed to the shaft 44, and the second support member 8 has a horizontal axis X <b> 5 (an example of a swing fulcrum) around it. It is supported so that it can swing.

  A connecting bolt 55 penetrating the base end side of the base end side plate 45 and the second support member 8 is provided. A long side portion of the base end side plate 45 is provided with an arcuate recessed portion 45a that can be contacted while accommodating the connecting bolt 55 when the operation lever 41 is operated to the unlock position. On the side of the base end plate 45 opposite to the shaft 44 of the connecting bolt 55 (on the side of the switching operation portion 43), a triangular pressing portion 45b having a rounded tip is provided.

(Switching operation unit 43)
As shown in FIGS. 9 and 10, the switching operation unit 43 includes a swing member 46 supported by the second support member 8 so as to swing about the horizontal axis X6, and a pair of second friction pads 47 (first A clamping member 48 that can be operated and held on the clamping side of the first friction pad 42.

  The swing member 46 is formed in a strip shape. A round hole is formed at the end of the swing member 46 opposite to the horizontal axis X6, and a steel ball 49 is forcibly fitted into the round hole.

  The clamping member 48 includes a pair of clamping parts 50 (corresponding to a second friction part) and a connecting bolt 51 that couples the pair of clamping parts 50 to each other.

  The holding part 50 accommodates a rectangular notch 52 provided in the middle of the long side part, a cylindrical member 53 provided adjacent to the notch 52, and a steel ball 49 on one end side of the cylindrical member 53. A teardrop-shaped groove 54 that can be provided and a second friction pad 47 provided on the other end side of the cylindrical member 53 are provided.

  In a state where the pair of sandwiching portions 50 are overlapped, the cylindrical member 53 of one sandwiching portion 50 enters the notch 52 of the other sandwiching portion 50, and the cylindrical member 53 of the other sandwiching portion 50 is While entering into the notch 52, the center axis | shaft of the cylindrical member 53 of these pair of clamping parts 50 is comprised so that the axial center X7 may be followed.

  Accordingly, the pair of sandwiching portions 50 are overlapped and the connecting bolt 51 is passed through the cylindrical member 53 of the pair of sandwiching portions 50, so that each of the pair of sandwiching portions 50 swings around the axis X7. It is configured to be movable.

Hereinafter, the clamping operation of the clamping member 48 will be described.
As shown in FIG. 9, when the pressing portion 45 b pushes the swing member 46 by swinging the operation lever 41, the swing member 46 swings to one side around the axis X <b> 6. A steel ball 49 attached to the opposite side of the shaft core X6 is in sliding contact with the inclined surface 54a of the groove 54, and one end side of the clamping part 50 swings to the open side by the cam action of the steel ball 49, and the other end of the clamping part 50 The pair of second friction pads 47 attached to the other end side of the holding part 50 moves to the holding side of the first friction pad 42 to hold the first friction pad 42.

  At this time, since the force of one second friction pad 47 and the force of the other second friction pad 47 cancel each other, the force of the pair of second friction pads 47 does not act on the seat back frame 2. Moreover, even if the contact surface of the second friction pad 47 and the contact surface of the first friction pad 42 are slightly deviated from the parallel state, the second friction pad 47 is operated to the clamping side of the first friction pad 42. Thus, the contact surface of the second friction pad 47 and the contact surface of the first friction pad 42 are parallel to each other, so that the contact between the second friction pad 47 and the first friction pad 42 is good. Thereby, the attitude | position of the frame 2 for seat backs can be maintained favorable.

Hereinafter, an operation for adjusting the posture of the seat back frame 2 will be described.
As shown in FIG. 11, the operation lever 41 is operated to the locked position (position where the second projecting pin 12 abuts). The pressing portion 45 b pushes the swing member 46, the swing member 46 swings to one side, and the sandwiching member 48 is in a sandwiched state in which the first friction pad 42 is sandwiched by the second friction pad 47. The imaginary straight line L1 passing through the contact point P of the operation lever 41 and the swing fulcrum X5 and the swing member 46 are orthogonal to each other. In other words, the virtual straight line L1 is along the direction of the normal L2 of the swing member 46. At this time, the vertical drag N acting on the pressing portion 45b acts on the swing fulcrum X5, and the operation lever 41 maintains its posture. In this way, by operating the operation lever 41 until it comes into contact with the second projecting pin 12, the clamping state of the clamping member 48 can be maintained without a special locking mechanism.

[Another embodiment]
(1) In the above embodiment, the reclining seat is exemplified by the configuration equipped in the driving unit 17 of the tractor. However, the reclining seat is not limited to the tractor, and examples thereof include a combiner, a rice transplanter, a lawn mower, and a construction machine. It can be applied to seats installed on different work vehicles.

(2) In the above embodiment, the configuration in which the virtual straight line L1 and the swing member 46 are orthogonal to each other is illustrated. However, the virtual straight line L1 and the swing member 46 may be substantially orthogonal.

(3) In the above embodiment, the swing member 46 is formed in a strip shape, and the upper surface of the swing member 46 on the side of the operation lever 41 is flat. However, when the imaginary straight line L1 passing through the contact point P of the operation lever 41 and the oscillating fulcrum X5 and the oscillating member 46 are substantially orthogonal, the operating lever 41 is placed on the upper surface of the oscillating member 46 on the operation lever 41 side. You may provide the recessed part (not shown) into which the press part 45b enters. Thereby, for example, even when the driver's finger unexpectedly touches the operation lever 41 and the force toward the unlocking position acts on the operation lever 41, the operation lever 41 is difficult to swing from the lock position. It becomes easy to maintain the attitude of the operation lever 41. In addition, as a shape of a recessed part, although semicircle shape, V shape, etc. are mentioned, it is not restricted to these shapes, It does not specifically limit.

  Furthermore, as shown in FIG. 12, when the position of the second projecting pin 12 is slightly tilted from the normal line L2 direction of the swinging member 46 to the side of the swinging direction from the unlocked position to the locked position. In addition, if the operation lever 41 is set to a position where it comes into contact with the second projecting pin 12, the position of the operation lever 41 can be more easily maintained at the lock position.

That is, as shown in FIG. 11, in the above embodiment, when the operation lever 41 is operated until it comes into contact with the second protruding pin 12, the virtual straight line L <b> 1 is along the normal L <b> 2 direction of the swing member 46. At this time, the line of action of the vertical drag N passes through the swing fulcrum X5, and no rotational moment is generated.
On the other hand, in this other embodiment, as shown in FIG. 12, when the operation lever 41 is operated until it comes into contact with the second protruding pin 12, the virtual straight line L1 is inclined from the normal line L2 direction of the swing member 46. ing. At this time, although not shown in FIG. 12, the line of action of the vertical drag N deviates from the oscillating fulcrum X5, and a moment arm is generated as much as the deviated amount, resulting in a rotational moment. Since the operating lever 41 is biased toward the second projecting pin 12 by such a rotational moment, for example, the driver's finger unexpectedly touches the operating lever 41 and the operating lever 41 is forced toward the unlocking position. Even when the operation lever is operated, the operation lever 41 is not easily swung from the locked position, and the posture of the operation lever 41 is easily maintained.

  The present invention can be applied to various seats in which a seat back frame is swingably connected to a seat cushion frame around a horizontal axis.

DESCRIPTION OF SYMBOLS 1 Frame for seat cushion 2 Frame for seat back 3 Armrest frame 4 Connection link 5 Seat cushion 6 Seatback 31 Armrest 41 Operation lever 22c, 42 First friction part 43 Switching operation part 47, 50 Second friction part L1 Virtual straight line P Contact Point X1 Horizontal axis X5 Oscillation fulcrum

Claims (4)

Connect the seat back frame to the seat cushion frame so that it can swing around the horizontal axis.
A first friction part provided on the seat back frame; a pair of second friction parts provided on the both sides of the first friction part provided on the seat cushion frame; and the second friction part. A switching operation unit that can be operated and held on the clamping side of one friction part, and an operation lever that can be operated artificially to operate the switching operation unit,
By sandwiching the first friction part by the second friction part via the switching operation part by the operation lever, the seat back frame can be held at a desired angle with respect to the seat cushion frame. A certain sheet. The operation lever and the switching operation portion are swingably supported on the seat cushion frame, and a pressing portion provided on the operation lever is in contact with the switching operation portion to perform a pressing operation. Configured to be operated to the clamping side of the first friction part,
At the contact point between the pressing unit and the switching operation unit and the swing fulcrum of the operation lever, a virtual straight line passing through the contact point and the swing fulcrum is set.
The virtual straight line and the switching operation unit are configured to be substantially orthogonal to each other in a clamping state in which the first friction unit is clamped by the second friction unit via the switching operation unit by the operation lever. The described sheet.   The seat cushion frame, the seat back frame, an arm rest frame rotatably connected to the seat back frame and supporting an arm rest, and the arm rest frame and the seat cushion frame are rotatably connected. The seat according to claim 1 or 2, comprising a connecting link that is configured to maintain a use posture of the armrest.   The seat according to any one of claims 1 to 3, wherein the seat cushion frame removably supports the seat cushion, and the seat back frame removably supports the seat back.

Images