JP5285261B2 - Chair reaction force adjustment device - Google Patents

Description

  The present invention relates to a chair reaction force adjusting device. More specifically, the present invention relates to a chair reaction force adjusting device having a reaction force mechanism that generates a reaction force by a reaction force spring.

  An example of a chair reaction force adjusting device is disclosed in Japanese Utility Model Publication No. 33-12133. FIG. 15 shows the chair reaction force adjusting device. The chair reaction force adjusting device includes a pair of left and right coil springs 103 between a receiving plate 101 and a pressing plate 102. The length of the coil spring 103 is adjusted by operating a female spiral 105 screwed into a screw shaft 104. The magnitude of the reaction force generated by the coil spring 103 is adjusted. Seat support beams 107 fixed to the swing frame 108 are provided on both sides of the fixed frame 106, and left and right coil springs 103 are disposed between the seat support beams 107.

Actual Kosho 33-12133

  However, in the above-described reaction force adjusting device, the length of the coil spring 103 is changed by changing the screwing amount of the female spiral 105 with respect to the screw shaft 104. Therefore, when the coil spring 103 is compressed, its axial direction is changed. A compressive force is applied to. For this reason, a large force is required for compression of the coil spring 103, and an operation force necessary for adjusting the reaction force is increased. In particular, when the two coil springs 103 arranged in parallel have to be compressed at the same time as in the above-described reaction force adjusting device, the operating force is further increased.

  An object of the present invention is to provide a chair reaction force adjusting device that can reduce an operation force required for reaction force adjustment.

In order to achieve this object, a chair reaction force adjusting device according to claim 1 includes a base, a back support that is supported on the rear side of the base by a first support shaft so as to be swingable up and down, and a base. A seat support whose upper part is supported so as to be swingable up and down and whose rear part is pivotally connected to the back support by a second support shaft located behind the first support shaft, and a base A reaction force mechanism for urging the back support and the seat support, and a reaction force adjusting mechanism for changing the force applied to the seat support by the reaction force mechanism. A spring support that is swingably supported by the base so as to be positioned and slidably supported by the seat support, and a reaction force spring provided between the spring support and the seat support The reaction force adjustment mechanism supports the seat by changing the angle of the reaction force spring around the vertical axis. It is intended to change the force to be applied to.

  Therefore, when the user of the chair sits on the seat and leans on the backrest, the back support rotates backward and the seat support swings downward while moving backward. For this reason, the reaction force spring is compressed, and a reaction force for returning the seat support body and the back support body is generated. Since the spring support is supported so as to be swingable with respect to the base so as to be always located in the seat support, the reaction force spring extends in the seat support. When the angle of the reaction force spring is changed around the vertical axis by the reaction force adjustment mechanism, that is, when the inclination angle of the reaction force spring in the width direction of the chair is changed, the load of the reaction force spring is changed. The component force that actually contributes to the drive changes, and the magnitude of the generated reaction force changes. The back support is connected to the rear portion of the seat support by a second support shaft that is located rearward of the first support shaft, which is a connection position with the base. For this reason, the generated reaction force acts at a position behind the back support.

In the chair reaction force adjusting device according to claim 2 , the reaction force spring has a pair of left and right reaction forces, and the reaction force adjustment mechanism changes the angle of the pair of reaction force springs symmetrically. Accordingly, the lengths of the pair of left and right reaction force springs are adjusted at the same time, and the reaction force can be applied without bias to the left and right of the chair.

Furthermore, the reaction force adjusting device for a chair according to claim 3 , wherein the reaction force adjusting mechanism has a single screw shaft that is rotatably supported by the seat support and has the direction of the screw reversed on the left and right sides, A spring mounting piece is screwed to each of the left and right sides of the screw shaft, and a reaction force spring is provided between the spring mounting piece and the spring support.

  Therefore, when the screw shaft is rotated, the left and right spring mounting pieces approach or separate from each other depending on the rotation direction. Thereby, the angle of a pair of left and right reaction force springs can be simultaneously changed in opposite directions.

  Since the spring mounting piece moves linearly along the screw shaft, the reaction force spring expands and contracts by adjusting the reaction force by rotating the screw shaft. In order to increase the reaction force, when the angle of the reaction force spring with respect to the front-rear direction is reduced, the reaction force spring is compressed, thereby obtaining a stronger reaction force.

According to a fourth aspect of the present invention, there is provided a chair reaction force adjusting device comprising: a base; a back support that is supported by a first support shaft on a rear side of the base so as to be swingable up and down; A seat support body that is freely supported and has a rear portion pivotally connected to the back support body by a second support shaft that is positioned behind the first support shaft, and the back support body and the seat with respect to the base body A reaction force mechanism for urging the support body, and a reaction force adjustment mechanism for changing the force applied to the seat support body by the reaction force mechanism. A spring support that is swingably supported and slidably supported with respect to the seat support, and a reaction force spring provided between the spring support and the seat support are provided. The force applied to the seat support is changed by changing the length of the reaction force spring.

  Therefore, when the user of the chair sits on the seat and leans on the backrest, the back support rotates backward and the seat support swings downward while moving backward. For this reason, the reaction force spring is compressed, and a reaction force for returning the seat support body and the back support body is generated. Since the spring support is supported so as to be swingable with respect to the base so as to be always located in the seat support, the reaction force spring extends in the seat support. When the length of the reaction force spring is changed by the reaction force adjustment mechanism, the magnitude of the generated reaction force changes. The back support is connected to the rear portion of the seat support by a second support shaft that is located rearward of the first support shaft, which is a connection position with the base. For this reason, the generated reaction force acts at a position behind the back support.

Further, in the chair reaction force adjusting device according to claim 5 , the reaction force adjusting mechanism includes a screw shaft disposed in the chair width direction and rotatably supported by the seat support, and a screw shaft. A cam body that is screwed and a follower that is moved in the front-rear direction of the chair by the cam body, a reaction spring is provided between the follower and the spring support, and the cam body is rotated by rotating the screw shaft. When the chair moves in the width direction, the follower moves in the front-rear direction of the chair and changes the length of the reaction spring, thereby changing the force applied to the seat support.

  Therefore, when the screw shaft is rotated, the cam body moves in the width direction of the chair and pushes the driven body against the reaction force of the reaction force spring, or conversely, the drive body is pushed back by the spring force of the reaction force spring. Thereby, the length of the reaction force spring is changed, and the magnitude of the generated reaction force is changed.

Further, in the chair reaction force adjusting device according to claim 6 , the spring support is supported by the base so as to be swingable, and the rear is supported slidably with respect to the seat support. It is. When the seat support body or the seat support body and the back support body swings with respect to the base body, such as when the user sits on a chair, the spring support body is centered on the front part while sliding the rear part against the seat support body. Oscillate as a whole. That is, the movement of the spring support is induced by the movement of the seat support. By making the position supported slidably with respect to the seat support at the rear part of the spring support, this position can be separated from the swing center.

By the reaction force adjustment device chair 請 Motomeko 1 wherein the substrate and the back support member which is supported freely swing vertically by a first support shaft on the rear side of the substrate, freely swing vertically upper side of the base body And a seat support whose rear portion is pivotally connected to the back support by a second support shaft positioned behind the first support shaft, and the back support and the seat support with respect to the base body. A reaction force mechanism that urges the body, and a reaction force adjustment mechanism that changes a force applied to the seat support by the reaction force mechanism, and the reaction force mechanism swings against the base body so as to be always located in the seat support body. A spring support that is movably supported and slidably supported with respect to the seat support, and a reaction force spring provided between the spring support and the seat support. The adjustment mechanism changes the force applied to the seat support by changing the angle of the reaction force spring around the vertical axis. Since it is possible to adjust the magnitude of the reaction force generated by changing the angle of the reaction force spring. For this reason, the operation force for reaction force adjustment is small, and usability can be improved. In addition, since the size of the seat of the chair is determined by the human body, the seat support must originally be enlarged to some extent and can be enlarged, but the reaction force mechanism is located in the seat support, A large space can be secured for arranging the force mechanism. Therefore, since the range in which the reaction force spring is tilted or expanded / contracted can be increased, the adjustable range of the reaction force can be greatly increased. Further, since the seat support is adjacent to the lower side of the seat, even if it is enlarged, the appearance is hardly impaired. On the other hand, a substrate that is conspicuous in appearance can be made compact. For these reasons, the design can be improved.

  Further, a reaction force is applied to the back support through the second support shaft, but the seat support can be enlarged as described above, so that the first support shaft and the second support shaft can be made larger. The distance between the two spindles (moment arm L) can be increased. For this reason, the moment which rotates the larger back support body by the load of reaction force spring can be generated, and the load of reaction force spring can be used more effectively as reaction force with respect to locking. Therefore, the load of the reaction force spring itself can be small. As a result, the operating force required for reaction force adjustment can be further reduced, and the reaction force adjustable range can be further increased.

In the chair reaction force adjusting device according to claim 2 , the reaction force spring has a pair of left and right reaction forces, and the reaction force adjustment mechanism changes the angle of the pair of reaction force springs to be bilaterally symmetrical. Therefore, a reaction force can be applied and stable locking operability can be obtained.

Furthermore, in the reaction force adjusting device for a chair according to claim 3 , the reaction force adjusting mechanism has a single screw shaft that is rotatably supported by the seat support and has the direction of the screw reversed on both the left and right sides. Since the spring mounting pieces are screwed to the left and right sides of the screw shaft, and the reaction force spring is provided between the spring mounting piece and the spring support, the angle of the pair of left and right reaction force springs is adjusted by the rotation of the screw shaft. It can be changed at the same time, a reaction force can be applied to the right and left sides of the chair without any bias, and stable rocking operability can be obtained.

According to a fourth aspect of the present invention, there is provided a chair reaction force adjusting device in which a reaction force mechanism is arranged in a seat support body. Here, since the size of the seat of the chair is determined by the human body, the seat support must originally be enlarged to some extent and can be enlarged. By making the reaction force mechanism located in the seat support body, a large space can be secured for arranging the reaction force mechanism. Accordingly, since the range in which the reaction force spring is expanded and contracted can be increased, the adjustable range of the reaction force can be greatly increased. In addition, since the seat support is adjacent to the lower side of the seat, even if a space for accommodating the reaction force spring is ensured, the appearance is hardly impaired. On the other hand, a substrate that is conspicuous in appearance can be made compact. For these reasons, the design can be improved. Furthermore, since the number of reaction force springs is one, which is the minimum number, not only the reaction force spring itself but also the number of parts for adjusting the length of the reaction force spring and the spring receivers are reduced. Thus, the manufacturing cost can be reduced, and the chair can be reduced in size and weight. In addition, since the space for accommodating the reaction force spring can be reduced, the chair can be reduced in size and weight, and the degree of design freedom can be improved.

In the chair reaction force adjusting device according to claim 5 , the cam body is moved in the axial direction of the screw shaft by the rotation operation of the screw shaft, and the follower is moved in the front-rear direction of the chair by the movement of the cam body. Since the length of the force spring is changed and the magnitude of the generated reaction force is adjusted, the operation force for adjusting the reaction force can be reduced, and the usability can be improved.

Furthermore, in the reaction force adjusting device for a chair according to claim 6 , the position of the slidably supported relative to the seat support is set to the rear part of the spring support so that the movement of the spring support is performed by the seat support. The guided position (rear part) can be separated from the swing center (front part), and the movement of the spring support can be stabilized. That is, since the movement of the spring support that induces the swing of the reaction force spring can be stabilized, the swing of the reaction force spring can be stabilized.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  1 to 5 show an example of an embodiment of a chair reaction force adjusting device of the present invention. The chair reaction force adjusting device includes a base body 1, a seat support body 2 supported on the upper side of the base body 1 so as to be swingable up and down, and a reaction force mechanism 3 for biasing the seat support body 2 against the base body 1. The reaction force mechanism 3 includes a reaction force adjustment mechanism 4 that changes the force applied to the seat support 2, and the reaction force mechanism 3 is swingable with respect to the base 1 so as to be always located in the seat support 2. And a spring support 5 slidably supported with respect to the seat support 2, and a reaction force spring 6 provided between the spring support 5 and the seat support 2. The reaction force adjusting mechanism 4 changes the force applied to the seat support 2 by changing the angle of the reaction force spring 6 around the axis A in the vertical direction. In the present embodiment, a back support 8 is provided on the rear side of the base 1 so as to be swingable up and down by a first support shaft 7, and the rear portion of the seat support 2 is more than the first support shaft 7. The second support shaft 9 located rearward is rotatably connected to the back support 8.

  The base body 1 is, for example, a main frame, and a cylindrical portion 1a to which an upper end of a chair leg 10 is attached is fixed to a rear portion thereof. The left and right side walls 1b, 1b at the front of the base 1 are provided with first long holes 11 that are elongated in the front-rear direction.

  The seat support 2 is, for example, a seat frame, and a seat 12 is attached so as to cover the seat frame, for example, as shown in FIG. The seat support 2 has a structure in which, for example, the left and right supports 2a and 2a are connected by a connecting portion 2b. The front portion of the seat support 2 is connected to the front portion of the base 1 by a third support shaft 13 so as to be swingable up and down. The third support shaft 13 passes through the first long hole 11 of the base body 1, and the seat support 2 is located with respect to the base body 1 within a range in which the third support shaft 13 moves in the first long hole 11. To move back and forth. The seat support 2 may be made of metal or resin, for example.

  The back support 8 is a synchro frame, for example, and a pair of left and right are provided. The lower portions of the respective back supports 8 are disposed between the left and right supports 2a and 2a of the seat support 2 and the base 1 as viewed from above. The lower end of the back support 8 is connected to the base 1 by a first support shaft 7 so as to be swingable up and down. Further, an intermediate position of the back support 8 is rotatably connected to the rear portion of the seat support 2 by the second support shaft 9. The first support shaft 7 and the second support shaft 9 are separated by a distance L. The left and right back supports 8 extend obliquely upward, and a backrest (not shown) is attached to these upper portions.

  The spring support 5 of the reaction force mechanism 3 is composed of, for example, two side plates 5a and 5a and a spring pressing plate 5b fixed to the rear ends thereof, and the left and right supports of the seat support 2 when viewed from the side. Between 2a and 2a, it is arrange | positioned inside the base | substrate 1 in the state seen from the top. The front end of the spring support 5 is connected to the base body 1 by a fourth support shaft 14 so as to be swingable up and down. Further, a second long hole 16 through which the screw shaft 15 passes is formed behind the position where the fourth support shaft 14 passes through the side plates 5a, 5a. The second long hole 16 is elongated in the front-rear direction of the chair, and the width in the vertical direction is substantially the same as the diameter of the screw shaft 15. For this reason, when the spring support 5 moves relative to the base body 1, the outer peripheral surface of the screw shaft 15 slides against the edge of the second long hole 16. That is, the spring support 5 is slidable with respect to the seat support 2 that supports the screw shaft 15. Further, ball bearing type rear spring receivers 17 are attached to both ends of the spring pressing plate 5b. The shape of the second long hole 16 is such that even if the seat support 2 moves, the plane parallel to the upper surface or the lower surface of the seat support 2 passes through the central axis of the third support shaft 13. The shape always passes through the center of 17 spherical surfaces.

  For example, a pair of left and right reaction force springs 6 of the reaction force mechanism 3 are provided between the reaction force adjustment mechanism 4 attached to the seat support 2 and the spring support 5.

  The reaction force adjustment mechanism 4 changes the angle of the pair of left and right reaction force springs 6 to be bilaterally symmetric. For example, as shown in FIG. It has one screw shaft 15 that is reversed. Spring mounting pieces 18 are screwed to the left and right sides of the screw shaft 15, and a reaction force spring 6 is provided between the spring mounting pieces 18 and the spring support 5.

  The screw shaft 15 is disposed on the connecting portion 2b of the seat support 2 and is rotatably supported by the left and right supports 2a and 2a. One end of the screw shaft 15 protrudes greatly to the side of one support body 2a, and a grip 20 is attached to the protruding portion. Therefore, the screw shaft 15 can be turned by turning the grip 20. The screws of the screw shaft 15 are reversed at the portion where the left and right spring mounting pieces 18 are screwed together, and the left and right spring mounting pieces 18 are brought closer to each other by changing the rotation direction of the screw shaft 15 (FIG. 2). ) Can be moved away (Fig. 1).

  Ball bearing type front spring receivers 19 are attached to the left and right spring mounting pieces 18. A reaction force spring 6 is provided between the front spring receiver 19 of the spring mounting piece 18 and the rear spring receiver 17 of the spring support 5.

  A gas spring 21 with a length lock mechanism is provided between the base 1 and the seat support 2 (shown in FIGS. 4B and 5B). In this embodiment, a gas spring 21 is provided between the first support shaft 7 and the third support shaft 13 that supports the seat support 2 on the base 1. By providing the gas spring 21 between the first support shaft 7 and the third support shaft 13, the gas spring 21 can be disposed in the base 1.

  When the length of the gas spring 21 can be changed by releasing the lock of the length lock mechanism of the gas spring 21, the distance between the first support shaft 7 and the third support shaft 13 can be changed. Therefore, the seat support 2 can be moved back and forth with respect to the base 1, and thus the back support 8 can be rotated with respect to the base 1, and the inclination angle of the back support 8 can be changed. .

  On the other hand, when the length lock mechanism of the gas spring 21 is locked and the length of the gas spring 21 is fixed, the back support 8 cannot be moved back and forth with respect to the base 1. The back support 8 cannot be rotated relative to the back support 8, and the inclination angle of the back support 8 cannot be changed. That is, the locking can be fixed by the gas spring 21. The operation link 21 a of the length lock mechanism of the gas spring 21 is connected to an operation lever (not shown) by an operation wire 22. For example, the operation lever is disposed below the seat 12, and the operation link 21 a is moved by operating the operation lever to operate the length lock mechanism of the gas spring 21.

  Next, the operation of the reaction force adjusting device will be described.

  When the user sits on a seat (not shown) and leans on a backrest (not shown) from the state shown in FIG. 4 where the user does not sit on the chair, the seat support 2 swings downward about the third support shaft 13. At the same time, the back support 8 falls back (rotates) around the first support shaft 7. At this time, the back support 8 falls backward with the first support shaft 7 as the center, so that the seat support 2 is also moved backward while swinging downward. That is, the third support shaft 13 moves rearward in the first long hole 11 of the base 1, and the seat support 2 also moves rearward while swinging downward. For this reason, as shown in FIG. 5, the spring attachment piece 18 attached to the screw shaft 15 also moves rearward, and the reaction force spring 6 is compressed to generate a reaction force.

  With the movement of the seat support 2, the screw shaft 15 moves in the second long hole 16 provided in the spring support 5. Even if the seat support 2 moves, the shape of the second long hole 16 is such that the plane parallel to the upper surface or the lower surface of the seat support 2 passes through the central axis of the third support shaft 13. Since the shape always passes through the center of the spherical surface and the screw shaft 15 slides on the edge of the second long hole 16, the spring support 5 is swung downward in the same manner as the seat support 2. From the viewpoint, the reaction force spring 6 and the spring support 5 can always be positioned in the seat support 2. That is, the reaction force mechanism 3 can be prevented from protruding above or below the seat support 2. Moreover, since the angle of the seat support body 2 and the reaction force spring 6 seen from the side can be matched, the reaction force spring 6 can be efficiently expanded and contracted by the movement of the seat support body 2. That is, although the seat support 2 and the spring support 5 have different rotation centers, the swinging of the spring support 5 and the reaction force spring 6 with respect to the seat support 2 can be suppressed when the seat support 2 swings.

  When the length lock mechanism of the gas spring 21 is locked, the backrest can be fixed at a desired angle against the reaction force of the reaction force spring 6.

  On the other hand, when the seated person leaves the backrest and the lock of the length lock mechanism of the gas spring 21 is released, the back support 8 and the seat support 2 are returned to their original positions by the reaction force of the reaction force spring 6 and the gas spring 21. The backrest can be returned to its original position.

  The magnitude of the reaction force of the reaction force mechanism 3 by the reaction force adjustment mechanism 4 is adjusted as follows. That is, the reaction force adjusting device 4 of the present embodiment moves the front end of the reaction force spring 6 around the rear end of the reaction force spring 6 in the width direction of the chair. Change the angle and adjust the reaction force.

  The seat support 2 is supported by the third support shaft 13 so as to be swingable up and down with respect to the base body 1, and the third support shaft 13 passes through the first long hole 11 provided in the base body 1. The movement of the seat support 2 with respect to the base body 1 is restricted by rotation about the front-rear direction and the left-right direction as rotation axes. For this reason, it is the component force in the front-rear direction that actually contributes to driving the movement of the seat support 2 relative to the base body 1 in the load of the reaction force spring 6. Therefore, if the inclination of the reaction force spring 6 with respect to the front-rear direction increases as shown in FIG. 1, the component force in the front-rear direction decreases, and the reaction force acting on the seat support 2 and the back support 8 decreases. On the other hand, when the inclination of the reaction force spring 6 with respect to the front-rear direction is reduced as shown in FIG. 2, the component force in the front-rear direction is increased, and the reaction force acting on the seat support 2 and the back support 8 is increased.

  In the present embodiment, since the pair of left and right reaction force springs 6 are symmetrically inclined, the left and right component forces of the left and right reaction force springs 6 cancel each other. For this reason, the stability of operation can be improved.

  When the user of the chair rotates the grip 20 to separate the left and right spring mounting pieces 18, the left and right reaction force springs 6 are inclined toward the outside in the width direction of the chair around the rear spring receiver 17. For this reason, as shown in FIG. 1, the inclination angle of the reaction force spring 6 increases, and the component force (component force in the front-rear direction) that actually contributes to the drive of the seat support 2 out of the load of the reaction force spring 6 decreases. However, the reaction force generated is weakened. At the same time, the length of the reaction force spring 6 is increased, that is, the amount compressed is reduced, and the reaction force generated from this is weakened.

  On the other hand, when the grip 20 is reversely rotated to narrow the interval between the left and right spring mounting pieces 18, the left and right reaction force springs 6 are inclined toward the inner side in the width direction of the chair around the rear spring receiver 17. For this reason, as shown in FIG. 2, the inclination angle of the reaction force spring 6 is reduced, the component force that actually contributes to the drive of the seat support 2 in the load of the reaction force spring 6 is increased, and the reaction force to be generated is Become stronger. At the same time, the length of the reaction force spring 6 is shortened, that is, the amount to be compressed is increased, and the reaction force generated from this also increases.

  As described above, the reaction force can be adjusted only by rotating the grip 20, so that it is easy to use. The rotation operation of the grip 20 can be performed in a state where the user is not sitting on the chair, and can also be performed while sitting on the chair. Moreover, even if the back support body 8 is not tilted as shown in FIG. 4, the back support body 8 is tilted as shown in FIG. Further, the length lock mechanism of the gas spring 21 can be locked, or the lock can be released.

  Adjustment of the component force that actually contributes to the drive of the seat support 2 out of the load of the reaction force spring 6 (hereinafter referred to as component force adjustment) and the length adjustment of the reaction force spring 6 change the angle of the reaction force spring 6. Therefore, it can be adjusted with a small operating force compared to the case where the length is adjusted by applying a force in the axial direction to the reaction force spring 6. For this reason, it is excellent in usability. In addition, in the case of changing the angle, the component force adjustment of the reaction force spring 6 and the fine adjustment of the length of the reaction force spring 6 are easy. From this point of view, it is easy to use. Further, since the angle of the reaction force spring 6 is changed by sliding the spring mounting piece 18 by the rotation of the screw shaft 15, the component force adjustment of the reaction force spring 6 and the length of the reaction force spring 6 can be finely adjusted from this point. It becomes easy.

  Since the spring support 5 is swingably supported with respect to the base body 1 so as to be always located in the seat support 2, the reaction force spring 6 extends in the seat support 2. Since the size of the seat of the chair is determined by the human body, the seat support 2 must originally be made somewhat large and can be made large. Since the reaction force mechanism 3 is always located in the seat support body 2 having such a property, a large space can be secured in the seat support body 2 in order to arrange the reaction force mechanism 3. Therefore, since the range in which the reaction force spring 6 is tilted and expanded / contracted can be increased, the adjustable range of the reaction force can be greatly increased. In addition, since the reaction force spring 6 is inclined to the left and right, the length of the initial state is the same even if the space in which the reaction force spring 6 is arranged is the same in the front-rear direction as compared to the case where the reaction force spring 6 is arranged straight. Can be used, and the amount of expansion and contraction of the reaction force spring 6 can be increased. From this point, the adjustable range of the reaction force can be increased.

  Furthermore, since the seat support 2 is adjacent to the lower side of the seat 12, even if the seat support 2 is enlarged, it is difficult to impair the appearance. On the other hand, it is not necessary to provide the reaction force mechanism 3 and the reaction force adjustment mechanism 4 on the substrate 1 that is conspicuous in appearance, and it can be made compact. For these reasons, the design can be improved.

  In the present embodiment, since the gas spring 21 is disposed in the base body 1, the gas spring 21 is not conspicuous in appearance, and the design can be improved from this point.

  In the present embodiment, the back support 8 is connected to the rear portion of the seat support 2 by a second support shaft 9 that is located behind the first support shaft 7, which is a connection position with the base 1. For this reason, the reaction force of the reaction force spring 6 can be applied to a position behind the back support 8. That is, a reaction force is applied to the back support 8 via the second support shaft 9, but the seat support 2 can be enlarged as described above. Since the distance (moment arm L) between the shaft 7 and the second support shaft 9 can be increased, a larger moment can be generated by the load of the reaction force spring 6. The load can be used more effectively as a reaction force against locking. For this reason, the load of the reaction force spring 6 can be small. As a result, the operating force necessary for reaction force adjustment can be further reduced, and the reaction force adjustable range can be further increased.

  In addition, since the pair of reaction force springs 6 are provided on the left and right sides, and these angles are changed to be bilaterally symmetric, the pair of left and right reaction force springs 6 can be expanded and contracted. Reaction force can be applied. For this reason, stable locking operability can be obtained.

  Moreover, the grip 20 of the reaction force adjusting mechanism 4 can be provided on the seat support 2 by always positioning the spring support 5 in the seat support 2. Here, when the grip 20 is provided on a member other than the seat support 2, for example, the base 1, the grip 20 cannot be moved in conjunction with the movement of the seat support 2. For this reason, if the seat supporter 2 moves rearward by tilting the backrest, the positional relationship between the seat supporter 2 and the grip 20 changes and the operability is deteriorated. In addition, since the positional relationship between the seat 12 that covers the seat support 2 and the screw shaft 15 to which the grip 20 is attached is changed by the movement of the seat support 2, a large cut is made to avoid interference between the seat 12 and the screw shaft 15. It is necessary to provide a notch.

  On the other hand, in the present invention, since the grip 20 can be provided on the seat support 2, the grip 20 can be moved together with the seat support 2 even if the seated person tilts the backrest. A relationship can be maintained. For this reason, it is excellent in operability and easy to use. Further, since the positional relationship between the seat 12 and the screw shaft 15 can be maintained, as shown in FIG. 7, the notch 12a for avoiding interference with the screw shaft 15 formed on the seat 12 can be reduced, and the appearance can be reduced. Deterioration can be suppressed.

  Further, the front end of the spring support 5 is connected to the base body 1 by the fourth support shaft 14 so as to be vertically swingable, and the screw shaft 15 is slid on the edge of the second long hole 16 when the seat support 2 is moved. By doing so, the movement of the spring support 5 is limited to a certain movement. Moreover, shakiness of the spring support 5 can be prevented. For these reasons, the reaction force mechanism 3 always generates the reaction force in the same manner, and a stable operation can be obtained.

  Further, the screw shaft 15 passed through the second long hole 16 is for changing the angle of the reaction force spring 6, but the screw shaft 15 is passed through the second long hole 16 of the spring support 5. Thus, the control of the movement of the spring support 5 and the support of the screw shaft 15 that must be long over the entire width of the seat support 2 can be used together, and the number of parts can be reduced.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

  For example, in the above description, the pair of left and right reaction force springs 6 is provided, but the number of reaction force springs 6 is not limited to two, and may be one or three or more.

  In the above description, the gas spring 21 is provided, but the gas spring 21 may be omitted.

  In the above description, the angle of the reaction force spring 6 is changed by linearly moving the front end of the reaction force spring 6 by the screw shaft 15; You may make it move. For example, you may move along the circular arc centering on the rear end of the reaction force spring 6. FIG.

  In the above description, the angle of the reaction force spring 6 is changed by moving the front end around the rear end. However, the present invention is not limited to this. For example, the rear end is moved around the front end. The angle of the reaction force spring 6 may be changed by changing the angle, and the angle of the reaction force spring 6 is changed by moving both front and rear ends around the position of the reaction force spring 6 in the axial direction. You may do it.

  That is, it is only necessary that the angle of the reaction force spring 6 can be changed in the width direction of the chair.

  In the above description, the seat support body 2 and the back support body 8 are provided separately, and a so-called synchro-rocking type chair that locks them in conjunction with each other is taken as an example, but a chair other than the synchro-rocking type may be used. . For example, a chair of a type in which the back seat is locked together may be used. That is, a base, a seat support supported on the upper side of the base so as to be swingable up and down, a reaction force mechanism that urges the seat support against the base, and the reaction force mechanism is applied to the seat support. A reaction force adjusting mechanism for changing the force, and the reaction force mechanism is slidably supported by the base so as to be always located in the seat support body and slidably supported by the seat support body And a reaction force spring provided between the spring support and the seat support, and the reaction force adjusting mechanism changes the angle of the reaction force spring around the vertical axis. The force applied to the seat support may be changed.

  In the above description, the reaction force adjustment mechanism 4 changes the force applied to the seat support 2 by changing the angle of the reaction force spring 6 around the vertical axis A. However, it is not necessarily limited to this configuration, the reaction force spring 6 is changed to one, and the length of the reaction force spring is changed by converting the displacement in the width direction of the chair into the displacement in the front-rear direction by the cam mechanism, thereby supporting the seat. The force applied to the body 2 may be changed.

  The reaction force adjusting mechanism 4 having such a configuration is shown in FIGS. The reaction force adjusting mechanism 4 includes a single screw shaft 15 disposed in the width direction of the chair and rotatably supported by the seat support 2, a cam body 23 screwed to the screw shaft 15, a cam The body 23 has a follower 24 that is moved in the front-rear direction of the chair, the reaction force spring 6 is provided between the follower 24 and the spring support 5, and the cam body 23 is attached to the chair by rotating the screw shaft 15. When it moves in the width direction, the follower 24 moves in the front-rear direction of the chair and changes the length of the reaction force spring 6, thereby changing the force applied to the seat support 2.

  The screw shaft 15 is, for example, a cylindrical screw portion 15b fitted to a shaft portion 15a so as not to be relatively rotatable, and a cam body 23 is screwed into the screw portion 15b. The rear side surface of the cam body 23 is, for example, an inclined surface in which one side in the width direction of the chair protrudes from the other side, and constitutes a cam surface 23a. Further, the front surface of the follower 24 is, for example, an inclined surface that protrudes from the other side of the chair in the width direction, and constitutes a sliding surface 24a.

  The screw portion 15b, the cam body 23, and the driven body 24 are accommodated in a cam chamber 25 provided below the connecting portion 2b of the seat support body 2. The side walls 25a and 25a of the cam chamber 25 are provided with holes 26 having a diameter larger than that of the shaft portion 15a of the screw shaft 15 and smaller than that of the screw portion 15b. The shaft portion 15 a passes through the left and right holes 26. The distance between the left and right side walls 25a, 25a is substantially equal to the length of the threaded portion 15b.

  A front spring receiver 19 is formed at the rear portion of the driven body 24. The receiving portion 19 a of the front spring receiver 19 has a larger diameter than the driven body 24. The rear wall 25b of the cam chamber 25 is provided with a hole 27 having a diameter larger than that of the driven body 24 and smaller than that of the receiving portion 19a of the front spring receiver 19, and the driven body 24 enters the cam chamber 25 through the hole 27. Has been inserted. Since the receiving portion 19a cannot pass through the hole 27, it functions as a stopper that prevents the driven member 24 from being pushed back more than necessary by the reaction force spring 6 by hitting the rear wall 25b. Further, the follower 24 is provided with a stopper 24b. The stopper 24b hits the rear wall 25b when the driven body 24 is pushed out to the rearmost position by the cam body 23, and prevents the driven body 24 from being pushed out more than necessary.

  A rear spring receiver 17 is attached to the spring support 5, and the reaction force spring 6 is provided between the front spring receiver 19 and the rear spring receiver 17. The reaction force spring 6 is disposed in the center of the seat support 2 and the spring support 5 in the width direction along the front-rear direction of the chair. Therefore, the generated reaction force is balanced without being biased to the left or right, and the reaction force can be transmitted smoothly, so that the comfort of the chair can be improved.

  As the reaction force spring 6 of the present embodiment, a coil spring having a spring constant with a value that generates reaction forces corresponding to two reaction force springs 6 used in the reaction force adjusting device of FIG. 1 is used. However, the spring constant is not limited to this value, and coil springs having other values can be used. The action of the reaction force (spring reaction force) generated by the reaction force spring 6 on the locking reaction force can be adjusted by adjusting the position of the second support shaft 9. For example, by bringing the position of the second support shaft 9 closer to the first support shaft 7 of the back support body 8, the arm of the rotational moment (rocking reaction force) of the back support body 8 is shortened. The effect on the locking reaction force can be reduced. On the other hand, the arm of the rotational moment (rocking reaction force) of the back support 8 becomes longer by moving the position of the second support shaft 9 away from the first support shaft 7 of the back support 8, so that the reaction force spring The action of the six reaction forces on the locking reaction force can be increased. Further, the action of the spring reaction force on the locking reaction force is as follows. The angle θ in FIG. 14 (the line connecting the center of the third support shaft 13 and the center of the second support shaft 9 as viewed from the side) The angle can also be adjusted by adjusting the angle at which the line connecting the support shaft 7 and the center of the second support shaft 9 intersects. For example, the locking reaction force can be increased by increasing the angle θ. Conversely, the locking reaction force can be reduced by reducing the angle θ. For example, when the reaction force spring with a low spring constant or the reaction force spring with a high spring constant is used due to the adjustment range of the reaction force spring 6 (the amount of expansion and contraction of the reaction force spring 6 that can be secured) or the like, The rocking reaction force can be adjusted by changing the position of the support shaft 9 and the angle θ in FIG.

  When the user of the chair rotates the grip 20 and moves the cam body 23 to the position indicated by the solid line in FIG. 8, the driven body 24 is pushed back by the reaction force spring 6 until the stopper (receiving portion 19a) hits the rear wall 25b. This increases the length of the reaction force spring 6. That is, the amount of compression of the reaction force spring 6 is reduced, and the reaction force to be generated is weakened.

  On the other hand, when the grip 20 is rotated in the reverse direction and the cam body 23 is moved to the opposite side (two-dot chain line position in FIG. 8), the cam surface 23a of the cam body 23 and the sliding surface 24a of the driven body 24 slide, The follower 24 is pushed backward. For this reason, the length of the reaction force spring 6 is shortened, that is, the amount to be compressed is increased, and the reaction force to be generated is increased.

  As described above, the reaction force adjustment mechanism 4 of FIG. 8 can perform the reaction force adjustment only by the rotation operation of the grip 20, similarly to the reaction force adjustment mechanism 4 of FIGS. On the other hand, in the reaction force adjusting mechanism 4 of FIG. 8, since the number of reaction force springs 6 is one, not only the reaction force spring 6 itself but also components for adjusting the length of the reaction force spring 6 The number of spring receivers 17 and 19 can be reduced, the manufacturing cost can be reduced, and the chair can be reduced in size and weight. Moreover, since the accommodation space of the reaction force spring 6 can be reduced, the chair can be reduced in size and weight and the degree of freedom in design can be improved. In the reaction force adjusting mechanism 4 in FIG. 8 as well, the reaction force spring 6 is disposed in the seat support 2, so that the length of the reaction force spring 6 in the initial state can be increased, and the amount of expansion and contraction can be increased. The reaction force adjustment range can be enlarged.

  In the above description, the first elongated hole 11 has a shape elongated in the front-rear direction. However, for example, as shown in FIG. 10, the first elongated hole 11 may be inclined according to or near the expansion / contraction direction of the gas spring 21. . By doing so, the movement direction of the third support shaft 13 when the seat support 2 is displaced relative to the base body 1 can be made to coincide with or approach the expansion / contraction direction of the gas spring 21. Can be reduced. Actually, the inclination angle is appropriately determined in relation to other members such as the gas spring 21, the base body 1, the seat support body 2, and the reaction force spring 6. It is conceivable to incline about 15 to 30 degrees with respect to the horizontal in the lowering direction. In FIG. 10, the first long hole 11 is inclined, for example, 25 degrees with respect to the horizontal.

  Further, in the above description, as is apparent from FIGS. 1A, 2A, 4B, 5B, etc., the second long hole 16 is formed on the spring support 5. By providing in the vicinity of the front portion, the vicinity of the front portion of the spring support 5 is slidably supported with respect to the seat support 2. However, the configuration is not necessarily limited to this, and the rear portion is supported by the seat support. 2 may be slidably supported. That is, the spring support 5 may be supported by the base 1 so as to be swingable, and supported by the rear support so as to be slidable with respect to the seat support 2. That is, an example of this case is shown in FIG. The second long holes 16 are provided in the left and right supports 2a, 2a of the seat support 2, for example. The second elongated hole 16 is provided at a position facing the rear portion of the spring support 5 and penetrates the fifth support shaft 28 that supports the rear portion of the spring support 5. The second long hole 16 is elongated in the front-rear direction of the chair, and the width in the vertical direction is substantially the same as the diameter of the fifth support shaft 28. For this reason, when the spring support 5 moves relative to the base body 1, the outer peripheral surface of the fifth support shaft 28 slides with respect to the edge of the second long hole 16. That is, the spring support 5 is slidable with respect to the seat support 2 that supports the fifth support shaft 28. The spring support 5 avoids interference with the screw shaft 15 by passing below the screw shaft 15.

  The spring support 5 swings around the fourth support shaft 14 when the fifth support shaft 28 moves in the second long hole 16 when the seat support 2 is displaced. Yes, the second slot 16 guides the movement of the spring support 5. The swing of the reaction force spring 6 is induced by the spring support 5. As shown in the example of FIG. 11, by supporting the rear portion of the spring support 5 slidably with respect to the seat support 2, the portion (rear portion) that induces the movement of the spring support 5 is set to the swing center position ( It can be separated from the front part. Therefore, rattling of the spring support 5 is suppressed, and the swinging is further stabilized, and the swinging of the reaction force spring 6 can be further stabilized.

  12 to 14 show an embodiment in which one reaction force spring 6 is provided, the first elongated hole 11 is inclined, and the rear portion of the spring support 5 is supported swingably with respect to the seat support 2. . In addition, the same code | symbol is attached | subjected to the member same as the above-mentioned member, and detailed description is abbreviate | omitted. In this reaction force adjusting device, since there is one reaction force spring 6, it is not necessary to project both side walls 1b, 1b of the front portion of the base 1 in the width direction unlike the reaction force adjusting device of FIG. For this reason, a width | variety is securable compared with the reaction force adjustment apparatus of FIG. Further, the connecting portion 2 b of the seat support 2 is provided with a window 29 leading to the cam chamber 25, and the screw portion 15 b and the cam body 23 are put into the cam chamber 25 through the window 29. However, the position where the window 29 is provided is not limited to the connecting portion 2 b, and may be provided on another wall around the cam chamber 25. Further, the gas spring 21 is disposed upside down with respect to the gas spring 21 of FIG.

  In the present embodiment, the first long hole 11 and the second long hole 16 have the same shape. Therefore, the same bush 30 can be used, and manufacturing cost can be reduced by sharing parts.

An example of embodiment of the reaction force adjustment apparatus of the chair of this invention is shown, (a) is a perspective view of the state which increased the inclination angle of the reaction force spring, (b) is the state of increasing the inclination angle of the reaction force spring. It is a top view. An example of embodiment of the reaction force adjustment apparatus of the chair of this invention is shown, (a) is a perspective view of the state which made the inclination angle of the reaction force spring small, (b) of the state which made the inclination angle of the reaction force spring small. It is a top view. It is the perspective view which showed an example of embodiment of the reaction force adjustment apparatus of the chair of this invention, and was seen from diagonally forward. An example of embodiment of the reaction force adjustment apparatus of the chair of this invention is shown, (a) is a top view of the state before falling a back support body, (b) is a side view of the state before falling a back support body. . An example of embodiment of the reaction force adjustment apparatus of the chair of this invention is shown, (a) is a top view of the state which fell the back support body, (b) is a side view of the state which fell the back support body. An example of embodiment of the reaction force adjustment apparatus of the chair of this invention is shown, and it is a top view of the screw shaft. It is a side view which shows an example of embodiment of the reaction force adjustment apparatus of the chair of this invention, and shows the relationship between the screw shaft and a seat. Another embodiment of the reaction force adjustment mechanism is shown and is a plan view thereof. Another embodiment of the reaction force adjustment mechanism is shown and is a cross-sectional view thereof. It is a side view which shows other embodiment of a 1st long hole. The example which changed the position of the 2nd long hole is shown, and it is sectional drawing of a seat support body and a spring support body. It is the perspective view which showed other embodiment of the reaction force adjustment apparatus of the chair of this invention, and was seen from diagonally back. It is a top view of the reaction force adjusting device. It is sectional drawing of the reaction force adjustment apparatus. It is a top view of the reaction force adjustment apparatus of the conventional chair.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base body 2 Seat support body 3 Reaction force mechanism 4 Reaction force adjustment mechanism 5 Spring support body 6 Reaction force spring 7 1st support shaft 8 Back support body 9 2nd support shaft 15 Screw shaft 18 Spring attachment piece A Up-down direction axis

Claims (6)

A base, a back support supported on the rear side of the base by a first support shaft so as to swing up and down, supported on the upper side of the base so as to swing up and down, and more than the first support shaft. A seat support whose rear part is pivotally connected to the back support by a second support shaft located at the rear , and a reaction force mechanism for biasing the back support and the seat support against the base And a reaction force adjusting mechanism that changes the force applied to the seat support by the reaction force mechanism, and the reaction force mechanism is swingably supported by the base so as to be always located in the seat support body. And a spring support that is slidably supported with respect to the seat support, and a reaction force spring provided between the spring support and the seat support, and the reaction force adjustment. The mechanism changes the angle of the reaction force spring around the vertical axis to the seat support. The reaction force adjustment device of the chair, characterized in that to change the Azukasuru force. The reaction force adjusting device for a chair according to claim 1, wherein the reaction force spring has a pair of left and right, and the reaction force adjustment mechanism changes an angle of the pair of reaction force springs to be bilaterally symmetric . The reaction force adjusting mechanism has a single screw shaft that is rotatably supported by the seat support and has the screw direction reversed on both the left and right sides, and a spring mounting piece is screwed on each of the left and right sides of the screw shaft. The reaction force adjusting device for a chair according to claim 2, wherein a reaction force spring is provided between the spring mounting piece and the spring support . A base, a back support supported on the rear side of the base by a first support shaft so as to swing up and down, supported on the upper side of the base so as to swing up and down, and more than the first support shaft. A seat support whose rear part is pivotally connected to the back support by a second support shaft located at the rear, and a reaction force mechanism for biasing the back support and the seat support against the base And a reaction force adjusting mechanism that changes the force applied to the seat support by the reaction force mechanism, and the reaction force mechanism is swingably supported by the base so as to be always located in the seat support body. And a spring support that is slidably supported with respect to the seat support, and a reaction force spring provided between the spring support and the seat support, The force applied to the seat support is changed by changing the length of the reaction force spring. Reaction force adjusting device of the chair. The reaction force adjustment mechanism includes a single screw shaft that is disposed in the width direction of the chair and is rotatably supported by the seat support, a cam body that is screwed to the screw shaft, and the cam body. A follower that is moved in the front-rear direction of the chair, the reaction force spring is provided between the follower and the spring support, and the cam body is moved in the width direction of the chair by rotating the screw shaft; Then, the follower moves in the front-rear direction of the chair and changes the length of the reaction spring, thereby changing the force applied to the seat support . Reaction force adjustment device. 6. The spring support is characterized in that a front part is supported by the base body so as to be swingable, and a rear part is supported so as to be slidable with respect to the seat support. The chair reaction force adjusting device according to any one of the above .

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