JP4702742B2 - Chair - Google Patents

Description

The present invention relates to a chair that is preferably used in an office or the like, and more particularly to a chair that can obtain an appropriate backrest reaction force.

This type of chair is generally provided with a reaction force device, and many of the chairs can be adjusted to a desired locking state by adjusting the backrest reaction force according to the physique.

For example, Patent Document 1 discloses a working portion that is set in the vicinity of a rotation support shaft of a back support rod by engaging a retainer serving as an input / output unit that causes elastic displacement with a coil spring that is an elastic body. The repulsive force is accumulated by compressing the coil spring through the retainer when the back support pivots due to the load, and the repulsive force output to the retainer according to the elastic displacement of the coil spring. The back support rod is configured to be urged in the standing direction.
JP 2003-189963 A

However, with such a structure, when you lean on the backrest, you will receive a reaction force from the spring in proportion to the tilting angle. There is a problem that smooth locking operation is hindered. As soon as the initial reaction force is reduced, it will start to fall just by lightly leaning on the backrest, and an appropriate backup function cannot be obtained.

On the other hand, it is conceivable to prepare a plurality of elastic bodies having different coefficient of restitution in advance and selectively switch them to realize a desired reaction force characteristic, but the structure becomes complicated.

The present invention has been made paying attention to such a problem, and is a novel useful device that can obtain an appropriate reaction force with respect to the tilting angle according to the purpose and application even when the backrest tilts even with a simple structure. The purpose is to provide a comfortable chair.

In order to achieve this object, the present invention takes the following measures.

In other words, the chair of the present invention includes an input / output unit that causes elastic displacement in the elastic body, and an operating unit that moves together with the back support rod is engaged on the input / output unit so that the back support rod and the operation unit are interposed. The input / output unit is moved or deformed by the input operation force to accumulate the repulsive force while elastically displacing the elastic body, and is output from the input / output unit via the action unit according to the elastic displacement of the elastic body. The reaction force device is configured so that the back support rod is urged in the standing direction by the repulsive force. Then, the reaction force device is configured such that when the engagement position of the action part on the input / output part is different, the magnitude of the repulsive force entering and exiting through the action part is different even if the elastic displacement of the elastic body is the same. As the back support rod is tilted, the engagement position of the action portion on the input / output portion is changed, and the elastic displacement of the elastic body defined by the tilt angle of the back support rod and the engagement position of the action portion is changed. Accordingly, the magnitude of the repulsive force entering and exiting from the input / output unit via the action unit is changed.

As such, depending on which part on the input / output part the engagement position of the action part is moved along with the tilting of the back support rod, the repulsive force entering and exiting from the input / output part via the action part, As a result, the back reaction force received by the user can be variously set in relation to the tilt angle. For this reason, depending on the purpose and application, the elastic displacement of the elastic body is shifted in a decreasing direction or shifted in an increasing direction from the history of the original tracing, and further increased at a certain position and decreased at a certain position. Setting can be performed. In addition, a single elastic body is sufficient, and it is not necessary to take a complicated structure in which a plurality of elastic bodies are prepared in advance and selectively used. Therefore, the structure is simplified.

To smoothly achieve the desired reaction force characteristics, the input / output part and the action part are tilted with respect to the input / output part while maintaining the engaged state of the action part of the back supporter with respect to the input / output part of the reaction force device. Accordingly, it is desirable to move in different directions and continuously change the engagement position.

In order to obtain a pressure relief characteristic along with the tilting when the backrest is tilted, the history of the elastic body's elastic displacement following the tilting angle of the back support rod unless the engagement position of the action part changes On the other hand, it is desirable to set the history so that the elastic displacement is reduced by changing the engagement position of the action portion with the backward inclination of the back support rod. According to this, it is possible to realize a smooth rocking operation without falling the backrest while putting the weight on.

In such a setting, the input / output unit rotates or deforms around the center of displacement, and the action unit rotates around the axis set at a position away from the center of displacement while maintaining the engaged state with the input / output unit. By configuring so, it can be easily realized.

When the reaction force device has an elastic body that accumulates the repulsive force by fixing one end side and applying a twisting force to the other end side, the input / output unit is placed in the direction crossing the twisting direction from the other end side. As the back support rod tilts backward, the action part is moved in the direction of twisting the elastic body through the input / output part, and the engagement position is displaced in the extension direction of the input / output part. It is good to keep. Examples of such elastic bodies include rubber torsion springs, metal torsion springs, and winding springs.

In this case, the tilt angle at which the reaction force relaxation characteristic is effective varies with the subsequent tilting of the back support rod depending on the initial engagement position on the input / output unit. The first reaction force adjustment mechanism that makes the initial engagement position of the action portion variable when the back support rod is upright with respect to the input / output portion extending from the other end side of the elastic body. It is desirable to provide

In pursuit of a wider variety of reaction force characteristics, and in preparation for cases where the reaction force characteristics are not as expected with the first reaction force adjustment mechanism alone due to individual differences and assembly errors of the elastic bodies, It is also effective to provide a second reaction force adjusting mechanism that can change the fixing position on the side in the torsion direction of the elastic body.

In addition, when the reaction force device has an elastic body that accumulates the repulsive force by fixing one end side and applying a bending force to the other end side, the surface intersecting with the bending direction of the elastic body is input / output. As the back support rod tilts backward, the operating portion is moved in the direction in which the elastic body is bent and deformed through the input / output portion, and the engagement position is displaced in the extending direction of the input / output portion. It is good to have a configuration. An example of such an elastic body is a leaf spring.

Also in this case, the tilt angle at which the reaction force relaxation characteristic is effective varies with the subsequent tilting of the back support rod depending on the initial engagement position on the input / output unit. In order to make effective adjustment, the first reaction position in which the initial engagement position of the action portion in the standing state of the back support rod is variable with respect to the input / output portion set on the surface intersecting with the bending direction of the elastic body. It is desirable to provide a force adjustment mechanism.

Similarly, in pursuit of a wider variety of reaction force characteristics, and in case the reaction force characteristics are not as expected with the first reaction force adjustment mechanism alone due to individual differences and assembly errors of elastic bodies, input / output It is also effective to provide a second reaction force adjusting mechanism that makes the engagement depth with the action part variable in the bending direction of the elastic body through the extension angle of the part.

Furthermore, when the reaction force device includes an elastic body that stores one repulsion force by fixing one end side and applying a compressive force or a pulling force to the other end side, the direction crossing the expansion / contraction direction from the other end side The input / output part is extended to perform a rotation operation to compress or pull the elastic body around the fulcrum, and the action part is compressed or the elastic body is compressed through the input / output part as the back support rod tilts backward. The engagement position may be displaced in the extending direction of the input / output unit while moving in the pulling direction. Examples of such an elastic body include a compression spring, a tension spring, and a gas spring using a compressible gas.

Also in this case, the tilt angle at which the reaction force relaxation characteristic is effective varies with the subsequent tilting of the back support rod depending on the initial engagement position on the input / output unit. In order to effectively adjust, the first reaction force adjustment mechanism that makes the initial engagement position of the action portion variable when the back support rod is upright with respect to the input / output portion extending from the other end side of the elastic body It is desirable to provide

Similarly, in pursuit of a wider variety of reaction force characteristics, and in preparation for cases where the reaction force characteristics are not as expected with the first reaction force adjustment mechanism alone due to individual differences and assembly errors of the elastic bodies, It is effective to provide a second reaction force adjusting mechanism that can change the fixing position on one end side of the lens in the compression or pulling direction.

Since the present invention has the above-described configuration, it is possible to provide a new and useful chair that can obtain an appropriate reaction force with respect to the tilt angle according to the purpose and application when the backrest tilts even with a simple structure. It becomes possible.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

The chair of this embodiment is provided with a function for appropriately adjusting the reaction force of the backrest at the time of rocking, and the basic configuration is as shown in FIG. The seat base 3 and the back support rod 4 are attached to the support base 2, and the reaction force device 5 is assembled between the support base 2 and the back support rod 4, and the reaction force is applied to the first support force. The reaction force adjustment mechanism (first adjustment unit) 6 can be adjusted.

More specifically, as shown in FIGS. 1 to 3, the support base 2 is made of die-cast, in which a front wall 22, a rear wall 23, and a side wall 24 are integrally formed on the front, rear, left and right of the bottom wall 21. Then, a rear support shaft 25 is installed between the left and right side walls 24, 24 in the rear inner space of the support base 2, and the base end portion 41 of the back support rod 4 is integrated with both ends of the rear support shaft 25. It is rotatably supported.

A front support shaft 26 is installed between the left and right side walls 24, 24 in the space inside the front portion of the support base 2, and between the front support shaft 26 and the back support rod 2, A link mechanism 7 is provided for interlocking the seat 3 with the backward tilting operation. The link mechanism 7 has a front end 73a attached to a first link 71 having a base end 71a pivotally attached to a cylindrical portion of the front support shaft 26 and a floating shaft 72 installed between the front end portions 71b of the first link 71. And a second link 73 pivotally connected to the middle portion of the back support rod 4 via a shaft 74, and when the back support rod 4 is in an upright state (when no person is seated). As shown in FIG. 3, the first link 71 is given a slightly leaning posture and the second link 73 is given a substantially horizontal posture, and when the back support rod 4 is tilted backward as shown in FIG. The rear end of the link 73 is rotated rearward and downward, and the first link 71 is shifted to a slightly tilted posture after standing up through the second link 73, and a state where the second link 73 sinks backward is taken. I try to make it. Since the seat receiver 3 is formed on the upper portion of the second link 73, the seat is locked.

The reaction force device 5 is mainly composed of an elastic body 51, and the elastic body 51 of this embodiment is an elastic material such as a rubber between the inner cylinder 51a and the outer cylinder 51b as shown in FIGS. The inner cylinder 51a is configured to be integrally rotatable with the front support shaft 26 and the inner layer portion of the elastic material 51c, and the outer cylinder 51b is configured to be integrally rotatable with the outer layer portion of the elastic material 51c. The elastic material 51c can be torsionally deformed between the inner layer portion and the outer layer portion. The outer cylinder 51b corresponding to the one end side of the present invention is fixed, and a rotational force is applied to the inner cylinder 51a corresponding to the other end side of the present invention via the front support shaft 26, whereby the elastic material 51c is elastically displaced. The repulsive force based on the torsional elasticity that causes the return torque is accumulated. The prismatic portion of the front support shaft 26 is provided with an arm-like input / output portion 52 in which the base end 52c is fixed so as to be integrally rotatable and the tip 52b extends in a direction substantially perpendicular to the torsion direction. As the portion 52 moves in a direction substantially orthogonal to the extending direction, a rotational force is applied to the front support shaft 26. On the other hand, in order to input and output a repulsive force between the elastic body 51 and the back support rod 4, an axial action portion that moves in association with the back support rod 4 and rotates with the back support rod 4. 53 is provided, and the action part 53 is engaged with the input / output part 52. That is, the input / output unit 52 is rotated by an operation force input from the back support rod 4 via the action unit 53, thereby repelling the elastic body 51 while elastically displacing the elastic body 51, and the elastic body 51 A repulsive force corresponding to the elastic displacement is output from the input / output unit 52 via the action unit 53, and the back support rod 4 is urged in the standing direction by this repulsive force.

At this time, the engagement between the action part 53 and the input / output part 52 adopts a structure necessary for adjusting the repulsive force. Specifically, an elongated hole-like second guide portion 52a is provided in the input / output portion 52 in a direction substantially perpendicular to the direction in which the repulsive force enters and exits (see arrow Z in FIG. 3), and the second guide portion 52a is provided with the second guide portion 52a. When the action portion 53 is slidably engaged and the engagement position of the action portion 53 on the input / output portion 52 is different, the repulsive force that enters and exits through the action portion 53 even when the elastic displacement of the elastic body 51 is the same. It is comprised so that a magnitude | size may take a different value. That is, the closer the engagement position is to the front support shaft 26, the shorter the moment arm r becomes and the greater the repulsive force (see FIG. 9), and the farther away the front support shaft 26 is, the longer the moment arm r becomes and the repulsive force becomes. It becomes small (refer FIG. 10).

The first reaction force adjusting mechanism 6 is capable of relatively moving the action portion 53 along the second guide portion 52a of the input / output portion 52 when the back support rod 4 shown in FIG. The initial engagement position of the action part 53 on the input / output part 52 is continuously changed without changing the elastic displacement of the elastic body 51. Specifically, as shown in FIGS. 3, 5, 6, and the like, a rotating body 61 is rotatably provided on a cylindrical portion of the rear support shaft 25 that can rotate integrally with the back support rod 4. The action portion 53 is taken out via the pair of links 62, and a drive arm 63 having a long hole-shaped first guide portion 63a is attached to the rear support shaft 25 so as to be integrally rotatable, and the action portion is attached to the first guide portion 63a. 53 is slidably engaged. The link 62 has an angle shape, and its base end is pivotally attached to a portion displaced from the rear support shaft 25 of the rotating body 61 via a shaft 62 a parallel to the rear support shaft 25. When the base end of the link 62 moves as a result, the action portion 53 installed between the tip ends of the link 62 moves along the first guide portion 63a. Thus, the initial engagement position of the action portion 53 along the extending direction of the input / output portion 52 is changed.

Then, the distance from the support shaft 25 to the action portion 53 is adjusted through the operation portion 64 shown in FIGS. 3 and 6 and is kept constant through the fixing portion 65 shown in FIG. As a premise, the rotating body 61 is a spur gear having teeth formed on the outer periphery, and the driving gear 66 is engaged with the outer periphery of the rotating body 61 so that the driving gear 66 can be rotated around the operation shaft 66a. Axis wearing. The rotating body 61 can be rotated via the drive gear 66 by rotating the grip-like operating portion 64 provided at the outer end of the operating shaft 66a.

On the other hand, as shown in FIGS. 6 and 7, the fixing portion 65 includes a stopper 65a attached to a connection wall 63x provided at the rear end of the pair of driving arms 63 via a guide 65d, and a stopper 65a. And a biasing spring 65b that meshes the teeth formed on the front surface of the stopper 65a with the outer periphery of the rotating body 61. In order to enable the operation by the operation unit 64 described above, the teeth of the stopper 65a must be separated from the outer periphery of the rotating body 61. For example, a wire transmission element is provided between the operation unit 64 and the stopper 65a. It is preferable that the connection is made via 65c, and the wire of the wire transmission element 65c is pulled when the operation portion 64 is pulled, so that the stopper 65a can be retracted against the biasing spring 65b.

Thus, when the operation portion 64 is pulled and rotated, the drive gear 66 is rotated via the operation shaft 66a, and a rotational displacement is given to the rotating body 61 meshing with the drive gear 66, so that the link 62 is pivotally attached. As a result of the rotation of 62a around the rear support shaft 25, the action portion 53 moves along the first guide portion 63a. When the operation portion 64 is pushed in or released from the required position, the stopper 65a is urged by the urging spring 65b, and the teeth on the front face mesh with the outer periphery of the rotator 61, so that the rotator 61 is stopped by the stopper 65a. The guide shaft 65d, the connection wall 63x, and the drive arm 63 are fixed to the rear support shaft 25 so as to be integrally rotatable.

When the rotating body 61 is fixed to the rear support shaft 25 so as to be integrally rotatable, the drive arm 63 is also fixed to the rear support shaft 25 so as to be integrally rotatable. The link 62 whose side is engaged with the first guide portion 63 a of the drive arm 63 via the action portion 53 is also integrated with the rear support shaft 25, and when the rear support shaft 25 rotates, the link 62 also moves together with the rotating body 61. Even if the back support rod 4 is rotated integrally, the distance from the rear support shaft 25 of the action portion 53 is kept constant.

During this time, since the drive gear 66 and the rotating body 61 remain engaged with each other, when the rotating body 61 rotates together with the rear support shaft 25, the drive gear 66 rotates together with the operating shaft 66a and the operating portion 64 while rotating the rotating body 61. Will be allowed.

In this way, as shown in FIG. 8, the action portion 53 integrally rotates on the locus P around the rear support shaft 25 together with the back support rod 4, and the input / output portion 52 (for example, the tip) is connected to the front support shaft 26. Around the trajectory R.

3, the reaction force support member 67 such as a bolt that is screwed to the support base 2 is brought into contact with at least one of the input / output unit 52 or the drive arm 63 when the back support rod 4 is in the standing state. Thus, further forward tilting operation of the back support rod 4 is prohibited, and at the same time, no repulsive force acts on the action portion 53. Also, at this time, as shown in FIG. 5, the first guide portion 63a and the second guide portion 52a are set to be parallel, and when the rotating body 61 rotates, the action portion 53 is smoothly moved between the guide portions 63a, The elastic body 51 is not caused to be elastically displaced by sliding along 52a.

In addition, as shown in FIGS. 3 and 11, this embodiment is provided with a second reaction force adjusting mechanism 8 that makes the fixing position of one end side of the elastic body 51 variable in the torsion direction of the elastic body 51. . The second reaction force adjusting mechanism 8 is provided with a pressure receiving protrusion 51b1 on an outer cylinder 51b corresponding to one end of the elastic body 51, and a bolt-like shape screwed into the pressure receiving protrusion 51b1 to the bottom wall 21 of the support base 2. The adjusting member 81 is contacted and fixed, and the adjusting member 81 is screwed back and forth to adjust the initial phase of the outer cylinder 51b relative to the inner cylinder 51a, and hence the initial twist amount.

From the viewpoint of the operating force during reaction force adjustment, the above configuration can be said to be a configuration that provides an effect of reducing the operating force. That is, as shown in FIG. 3, the initial displacement of the action portion 53 on the input / output portion 52 is not changed without changing the elastic displacement of the elastic body 51 in the standing state of the back support rod 4, in other words, without twisting the elastic body 51. Since the engaging position is variable, the operating force becomes substantially constant as shown in FIG. 17A, unlike the conventional device in which the operating force increases as the reaction force is adjusted as shown in FIG. Moreover, since the initial engagement position of the action portion 53 on the input / output portion 52 is variable while the repulsive force of the reaction force device 5 is received by the reaction force support member 67, the link 62, the rotating body 61, and thus the operation portion 6. There is no repulsive force, and only a small amount of operating force is needed for adjustment. And if the engaging position of the action part 53 on the input / output part 52 is different, the action part depends on the length r of the moment arm even if the tilt angle of the back support rod 4 is the same as shown in FIGS. 17 (B) b1 to b3 through 53, the magnitude of the repulsive force entering and exiting is different (exactly, the amount of elastic displacement (angle) φ changes, so each curve b1 to b3 is actually Although the shape is as shown in FIG. B4, this will be described later), it is possible to appropriately adjust the strength of the backrest reaction force through a slight operating force.

Further, from the viewpoint of the reaction force characteristics, the above structure can be said to be a structure that provides a reaction force relaxation characteristic that gradually reduces the rate of increase of the reaction force as the back support rod 4 tilts. That is, as the back support rod 4 is tilted, the action portion 53 moves on the locus P around the rear support shaft 25 as shown in FIG. 8, and the input / output portion 52 (for example, the tip) moves on the locus about the front support shaft 26. As a result of moving on R, the input / output unit 52 and the action unit 53 move in different directions as the back support rod 4 tilts. That is, once the reaction device 5 determines the engagement position of the action part a as shown in FIG. 28, the back support rod together with the input / output part b without moving the action part a on the input / output part b. If it rotates around the support shaft d of c, the backrest reaction force increases as shown in FIG. 17B b1 in proportion to the tilt angle of the back support rod. As shown in FIG. 5, the engagement position of the action portion 53 on the input / output portion 52 also changes as the back support rod 4 tilts, so that the elastic displacement (reaction force) inherently follows in FIG. A history such as b4 that gradually curves in a gradually decreasing direction from the history of 4 is traced. Thus, since the reaction force is relaxed in the second half of the locking, a smooth locking operation can be performed without forcibly leaning on the backrest so as to place the weight.

By the way, if the initial engagement position of the action portion 53 by the reaction force adjusting mechanism 7 is different, the engagement position of the action portion 53 accompanying the subsequent tilting of the back support rod 4 also shifts, so the tilt angle of the back support rod 4 The displacement (backrest reaction force) of the elastic body defined by the engagement position of the action portion 53 changes as shown in FIG. Accordingly, when the back support rod 4 is tilted backward, it is necessary to appropriately adjust whether the reaction force relaxation action is desired in the latter half as in c3 or whether the reaction force relaxation action is desired in the middle or the first half as in c2 or c1. Is possible. However, when such adjustment is performed, the initial reaction force also changes. Therefore, the reaction force characteristic can be further adjusted using the second reaction force adjustment mechanism 8 provided in this embodiment. That is, the second reaction force adjusting mechanism 8 can change the initial reaction force by translating the characteristic curve up and down as shown in FIG. By combining these adjustment functions, it is possible to effectively pursue various characteristics and the like such that the initial reaction force is the same as shown in FIG.

Further, when the above configuration is viewed from the viewpoint of the adjustment range, it can be said that such a configuration provides a wide range adjustment function that significantly changes the reaction force with a few operations. That is, when the action portion 53 is adjusted in the direction toward the tip of the input / output portion 52 as shown in FIG. 10 by the first reaction force adjusting mechanism 7 according to the present embodiment, the repulsive force that enters and exits is small (that is, the moment The arm r2 is long) and the elastic displacement (angle) φ2 is small with respect to the movement amount (kθ) of the back support rod, which is the force receiving body, so that the repulsive force accumulation of the elastic body 51 is reduced and reduced. When the operating portion 53 is adjusted in the direction toward the proximal end of the input / output portion 52 as shown in FIG. 9, the repulsive force that enters and exits is in a state suitable for the load receiving force (low load receiving state). By increasing the elastic displacement amount (angle) φ1 with respect to the same movement amount kθ of the back support rod 4 (ie, the moment arm r1 is short), the repulsive force accumulation increases and the load of the high load is increased. It will be in a suitable state (high load force receiving state). Therefore, by setting the low load receiving state when the external load is small and setting the high load receiving state when the external load is large, the back support rod 4 can be stopped at substantially the same position even if the external load is different. Thus, it is possible to support the load effectively by tilting the back support rod 4 equally regardless of the size of the seated person. In addition, when only the distance r from the displacement center changes as shown in FIG. 30A, or when only the displacement amount (angle) φ changes as shown in FIGS. 29 and 30B, In the present embodiment, the reaction force appearing on the back support rod 4 is increased / decreased in proportion to φ / r by changing these in conjunction with each other. Therefore, the effect of adjusting the strength of the reaction force is doubled even with a slight adjustment amount. The reaction force can be adjusted over a wide range. As is clear from FIG. 18C, there is a significant difference in the magnitude of the reaction force adjustment between when φ is constant and r is changed, and when both φ and r are changed.

In particular, the present embodiment is provided with the second reaction force adjusting mechanism 8, and the initial reaction force can be further adjusted if necessary, so that it further exceeds the adjustment range by the first reaction force adjusting mechanism 7. It is possible to adjust the reaction force in a wide range.

Hereinafter, the modification 1 of the said embodiment is demonstrated.

The modified example shown in FIG. 12 does not bring out the action part via the rotating body and the link as in the above-described embodiment, but is provided so as to be movable along the first guide part 63a and the second guide part 52a. An action portion 53 is attached to 165, and the fixing portion 165 can be fixed to the driving arm 63 provided with the first guide portion 63a at the initial engagement position.

Also in this case, the input / output part 52 extends from the elastic body 51 in a direction perpendicular to the twisting direction, and the repulsive force entering and exiting through the action part 53 differs depending on the engagement position of the action part 53. It is. Further, the two guide portions 63a and 52a are set so as to be parallel when the back support rod 4 is in the standing state, and the action portion 53 is formed in an axial shape so as to penetrate through both the guide portions 63a and 52a. is there.

On the other hand, the fixed portion 165 operates both the guide portions 63a and 53a by operating the grip-like operation portion 164 which is caused to pass through the action portion 53 through the sandwiching plate 165a disposed outside the pair of drive arms 63 and hangs downward. The operating portion 53 can be moved along the position of the operating portion 164, and the operating portion 164 is operated at a predetermined position, whereby the driving arm 63 is clamped between the clamping plates 165 a and 165 a, so It can be fixed in the engaged position.

In addition, when the back support rod 4 is in the standing state, the operation portion 164 is configured to protrude below the seat cover 20 as shown in FIG. A flight is easily secured.

Even if comprised in this way, since the elastic body 51 is not elastically displaced when the back support rod 4 is in the standing state, the reaction force can be adjusted with a constant operating force. As the back support rod 4 is tilted, the input / output part 52 and the action part 53 move in different directions. Specifically, the engagement position of the action part 53 with respect to the input / output part 52 gradually increases. Since it moves to the extending direction of 52, the reaction force relaxation characteristic accompanying tilting can also be obtained. Further, the closer the initial engagement position of the action portion 53 is to the base end side of the input / output portion 52, the shorter the arm of the moment when twisting the elastic body 51 and the elastic body 51 with respect to the same tilt angle of the back support rod 4. The elastic displacement amount (angle) increases, and conversely, the arm of the moment when twisting the elastic body 51 becomes longer as the elastic body 51 is positioned closer to the distal end side of the input / output unit 52 and Since the amount of elastic displacement (angle) is small, a wide range adjustment function is also provided.

Above all, the structure is simpler than that of the above embodiment, and the structure can be made compact and the effect of cost reduction can be expected.

Of course, this does not prevent the configuration in which a pair of input / output portions 52 are provided on both sides of the drive arm 63 and the fixing portion 165 is attached to the input / output portions 52.

Next, Modification 2 of the above embodiment will be described.

In FIG. 13, the elastic body 51 is attached to a rear support shaft 125 provided on the rear end side of the seat, and the input / output unit 52 is extended from the elastic body 51 forward so as to be orthogonal to the twisting direction. At the same time, the base end of the back support rod 4 is attached to a front support shaft 126 provided on the front end side of the seat through the elastic body 51. The shaft-like action portion 53 is configured to be slidable along the first guide portion 63ax provided on the back support rod 4 itself, and the action portion 53 is provided on the input / output portion 52 and is supported on the back support. When the heel 4 is in the standing state, it is slidably engaged with the second guide portion 52ax that is substantially parallel to the first guide portion 63ax. In order to fix the action part 53, for example, a fixing part 165 x serving as an operation part made up of a bolt and a nut is provided on the back support bar 4, and the action part 53 is fixed to the back support bar 4 by this fixing part 165 x and inserted. The initial engagement position of the action part 53 with respect to the output part 52 is determined.

Even if comprised in this way, there exists an effect completely equivalent to the said modification 1, Moreover, since the back support rod 4 itself can be used as a drive arm, further simplification of a structure is aimed at. Is possible.

Furthermore, the modification 3 of the said embodiment is demonstrated.

The modification shown in FIGS. 14 to 16 includes a first reaction force adjusting mechanism 106 for accurately adjusting the reaction force while experiencing the magnitude of the reaction force by slightly changing the configuration of the above embodiment. This is what is realized. In FIGS. 14 to 16, parts common to the first embodiment are denoted by the same reference numerals as necessary, and description of parts that do not require particular explanation is omitted.

The first reaction force adjusting mechanism 106 takes out the action portion 53 from the rotating body 61 provided to be rotatable around the rear support shaft 25 of the back support rod 4 via the link 62 and removes the action portion 53 from the back support rod. 4 so as to be slidable along the first guide portion 63a of the drive arm 63 that rotates integrally with the drive arm 63, thereby changing the distance from the support shaft 25 to the action portion 53 of the back support rod 4 to the input / output portion 52. It is the same as that of the said embodiment in the point which makes the engagement position of the action part 53 variable. However, the second guide portion 152a of the input / output portion 52 to which the action portion 53 is slidably engaged is parallel to the first guide portion 63a when the back support rod 4 is upright as in the above embodiment. Instead, the guide direction is shifted in a direction that forms a predetermined angle α with respect to the first guide portion 63a.

In the configuration of FIG. 5, since the first guide portion 63a and the second guide portion 52a are parallel, even if the action portion 53 moves, the elastic body 51 is not displaced (compressed). The first guide portion 63a and the second guide portion 152a are not parallel to each other, and the second guide portion 152a is orthogonal to the direction in which the repulsive force enters and exits when the back support rod 4 is in the standing state (the arrow Z direction in FIG. 16). In order to slide the action portion 53 in a direction that forms a predetermined angle α with respect to the direction in which the action is performed, for example, the action portion 53 has a direction in which the back reaction force increases as indicated by arrows in FIGS. When the initial engagement position is changed by moving to the end side), the elastic body 51 is gradually displaced slightly in the compression direction via the input / output unit 52. This repulsive force is transmitted as a load torque to the operation unit 64 shown in FIGS. 6 and 7 through the rotating body 61 and the drive gear 66, so that the operator performs an operation while experiencing an operation force proportional to the backrest reaction force. As a result, accurate adjustment can be performed. In addition, if the reaction force support member 67 is brought into contact with at least one of the input / output unit 52 or the drive arm 63 to receive the reaction force, it is as large as when the retainer of the coil spring is directly operated in the compression direction. Since it is not necessary to receive the operation force, it is possible to maintain a state in which the operation force is greatly reduced.

Next, a second embodiment in which an elastic body of a type different from that of the first embodiment is used for the reaction force device 105 will be described with reference to FIGS. In FIGS. 19 to 21, parts that are the same as those in the above embodiment are given the same reference numerals as necessary, and descriptions of parts that do not require particular explanation are omitted.

The reaction force device 105 of this embodiment uses a leaf spring-like elastic body 151 having one end side 151a fixed to the support base 2 using a fixing plate 150 and the other end side 151b being a free end. The vicinity of one end 151a of the body 151 is pressed by a pressing member 281 described later to extend the other end 151b at a predetermined angle, and an external force is applied to the other end 151b so that the thickness direction indicated by the arrow in FIG. Cause bending deformation. Then, a surface substantially orthogonal to the bending direction of the elastic body 151 (the lower surface of the elastic body 151) is used as the input / output unit 152, and the action unit 53 that rotates together with the back support rod 4 is engaged with the input / output unit 152. ing. Since the input / output part 152 does not have a long hole shape as in the above-described embodiment, the engagement is merely abutment, and the second guide part referred to in the present invention is the input / output part 152 itself in this case. In this structure, as the extension angle of the elastic body 151 becomes deeper, the input / output unit 152 is more strongly pressed against the action part 53, and the repulsive force that enters and exits from the input / output part 152 through the action part 53 increases.

The first reaction force adjusting mechanism 206 is operated through the same operation unit as in the first embodiment, thereby rotating the drive gear 66, thereby changing the phase of the rotating body 61, The tip of the link 62 attached via the shaft 62a is slid to the first guide portion 63a of the drive arm 63 that rotates integrally with the rear support shaft 25 via the action portion 53, and the action portion when the back support rod 4 is in the standing state. The initial engagement position 53 can be adjusted. And the distance from the back support shaft 25 to the action part 53 is kept constant when the back support rod 4 tilts by the fixed part similar to the said embodiment.

Also in this embodiment, a second reaction force adjustment mechanism (second adjustment unit) 208 that adjusts the initial reaction force of the elastic body 151 is provided. The second reaction force adjusting mechanism is configured to screw the pressing member 281 into the fixing plate 150 and change the extension angle of the other end side 151b of the elastic body 151 according to the screwing position, so that the action portion 53 The engagement depth is variable in the bending direction of the elastic body 151 so that the initial reaction force can be adjusted.

Also in this configuration, the reaction force adjusting mechanism 206 can relatively change the initial engagement position of the action portion 53 with respect to the input / output portion 152 along the direction substantially perpendicular to the bending direction when the back support rod 4 is in the standing state. Therefore, the elastic body 151 is hardly bent and deformed at the time of adjustment, and the influence of the repulsive force can be eliminated to ensure a substantially constant operating force. In particular, if the drive arm 63 is supported by the reaction force support member 67 similar to that of the above-described embodiment, the operation force may be small.

Also, in this case, as the back support rod 4 tilts backward, the action portion 53 moves on a circle P centered on the rear support shaft 25 shown in FIG. The elastic body 151 pressed by the member 281 moves on a circle R centering on the pressing point X, and these moving directions are different. Therefore, when the back support rod 4 is tilted backward, the action portion 53 is input / output unit. The reaction force relaxation characteristics are obtained by gradually displacing the tip of 152.

Furthermore, in the state of FIG. 21 in which the action portion 53 is adjusted in the direction toward the tip of the input / output portion 52, the repulsive force that enters and exits is small (that is, the moment arm r is long) and the force receiving force, as in FIGS. The elastic displacement amount (angle) φ at a position a unit distance away from the pressing point X, which is the center of displacement, with respect to the movement amount (kθ) of the back support rod, which is the body, decreases, so that the repulsive force of the elastic body 51 is reduced. The accumulated energy is reduced and a state suitable for a low load receiving force (low load receiving state) is obtained, and conversely, the action portion 53 is adjusted in a direction toward the base end of the input / output portion 52 as indicated by an imaginary line in FIG. In this case, the repulsive force entering and exiting is large (that is, the moment arm r is short), and the elastic displacement amount (angle) φ is increased with respect to the same movement amount kθ of the back support rod 4, thereby storing the repulsive force. Increases to a state suitable for high load receiving force (high load receiving state). Similar wide range adjustment function and facilities embodiment also so that the facilities.

In this embodiment as well, when the reaction force adjusting mechanism 206 is configured to relatively move the action portion 53 in a direction that forms a predetermined angle with respect to a direction substantially orthogonal to the bending direction when the back support rod 4 is in the standing state. In addition, it is possible to realize the operability that allows the elastic body 151 to be slightly displaced to experience the reaction force.

Furthermore, a third embodiment in which an elastic body of a type different from that of the first embodiment is used for the reaction force device 205 will be described with reference to FIGS. 22 and FIG. 23, the same reference numerals are given to portions common to the above-described embodiment as necessary, and descriptions of portions that do not need to be described are omitted.

The first reaction force adjustment mechanism 306 according to this embodiment takes out the action part 53 from the rotating body 61 provided rotatably around the rear support shaft 25 of the back support rod 4 via the link 62, and the action part. The initial engagement position of the action portion 53 with respect to the input / output portion 52 can be varied by allowing the 53 to slide along the first guide portion 63a of the drive arm 63 that rotates integrally with the back support rod 4. This is the same as in the first embodiment. In addition, the input / output unit 52 to which the action unit 53 is slidably engaged is rotatably supported by the front support shaft 26, and the second guide portion 52 a of the input / output unit 52 is the back support rod 4. The point that is parallel to the first guide part 63a in the standing state and that the distance from the rear support shaft 25 to the action part 53 is kept constant when the back support rod 4 is tilted is the same as in the first embodiment. .

However, this embodiment is structurally different from the first embodiment in that the reaction force device 205 is configured using a compression spring type elastic body 251. This elastic body 251 accumulates a repulsive force by fixing one end side 251a and applying a compressive force to the other end side 251b. The input / output unit 52 is extended from the other end side 251b in a direction substantially orthogonal to the expansion / contraction direction. It is extended. The input / output portion 52 is pivotally attached to the front support shaft 26, and a pressure receiving protrusion 252 extends integrally on the front end side of the front support shaft 26, and the other end side 251 b of the elastic body 251 is elastically contacted with the pressure receiving protrusion 252. I'm allowed. The rotation operation of the input / output unit 52 around the front support shaft 26 and the expansion / contraction operation of the elastic body 251 are interlocked. The larger the amount of compression of the elastic body 251, the more repulsive force that enters and exits from the input / output unit 52 via the action unit 53. growing.

Also in this embodiment, a second reaction force adjustment mechanism (second adjustment unit) 308 for adjusting the initial reaction force is provided. The second reaction force adjusting mechanism 308 is configured to screw the pressing member 381 into the support base 2 and change the fixing position of the one end side 251a of the elastic body 251 according to the screwing position, so that the one end side 251a and the other end The amount of compression between the side 251b is variable, and the initial reaction force can be adjusted.

Also in this configuration, the reaction force adjusting mechanism 308 relatively positions the initial engagement position of the action portion 53 with respect to the input / output portion 52 along the direction substantially perpendicular to the expansion / contraction direction of the elastic body 251 when the back support rod 4 is in the standing state. Therefore, the elastic body 251 is hardly compressed at the time of adjustment, and the reaction force can be adjusted with a constant operating force by eliminating the influence of the repulsive force. This is also the same as the above embodiment in that if the drive arm 63 is supported by the reaction force support member 67 similar to that in the above embodiment, the operation force is very small.

Further, as the back support rod 4 tilts backward, the action portion 53 moves on a circle P centered on the rear support shaft 25 as shown in FIG. 26, since these move in different directions, the action portion 53 is displaced toward the front end side of the input / output portion 52 when the back support rod 4 is tilted backward, The point that the relaxation characteristics can be obtained from the middle is the same as in the first embodiment.

Further, when the action portion 53 is adjusted in the direction toward the tip of the input / output portion 52, the repulsive force that enters and exits is small (that is, the moment arm r is long) and the force receiving body, as in FIGS. The amount of elastic displacement (angle) φ at a position that is a unit distance away from the pressing point X, which is the center of displacement, with respect to the movement amount (kθ) of the back support rod is reduced, so that the repulsive force of the elastic body 51 is stored. When the operating portion 53 is adjusted in the direction toward the base end of the input / output portion 52, the repulsive force that enters and exits is large (that is, the load receiving force is low). The moment arm r is short) and the elastic displacement amount (angle) φ is increased with respect to the same movement amount kθ of the back support rod 4, so that the repulsive force accumulation increases and it is suitable for a high load receiving force. (High load force receiving state), the same wide range adjustment function as in the first embodiment So that the Waru.

In this embodiment as well, when the reaction force adjusting mechanism 306 is configured to relatively move the action portion 53 in a direction that forms a predetermined angle with respect to a direction substantially orthogonal to the bending direction when the back support rod 4 is in the standing state. In addition, it is possible to realize the operability that allows the elastic body 251 to be slightly displaced to feel the reaction force.

Furthermore, a fourth embodiment of the present invention will be described with reference to the drawings.

On the other hand, the chair shown in FIGS. 24 to 27 has a structure for changing the relative initial engagement position of the action portion 453 of the back support rod 4 with respect to the input / output portion 452 of the reaction force device 405. Is different.

That is, the chair reaction force adjusting mechanism 406 moves the reaction force device 405 to move the reaction force device 405 relative to the input / output unit 452 of the reaction force device 405 relative to the initial engagement position of the action portion 453 of the back support rod 4. The action portion 453 can be rotated together with the back support rod 4 in a state where the reaction force device 405 is fixed.

The reaction force device 405 uses the same elastic body 51 as in the first embodiment. In this embodiment, the reaction device 405 is used in reverse to fix the inner cylinder 451a corresponding to one end of the elastic body 51 to the case 410. The input / output part 452 extending substantially orthogonal to the twisting direction is extended from the outer cylinder 451b corresponding to the other end side. The case 410 is movable with respect to the support base 2, and the input / output part 452 is provided with a long hole-shaped guide part 452. On the other hand, the back support rod 4 is rotatably supported by the support base 2 via a support shaft 425, and an axial action portion 453 is provided in the vicinity of the support shaft 425, and this action portion 453 is connected to the input / output portion 452. The second guide portion 452a is engaged with the second guide portion 452a.

Then, the relative movement direction of the reaction force device 405 and the back support rod 4 in the standing state of the back support rod 4 shown in FIG. 25 is set to a predetermined angle β with respect to the relative slide direction of the action portion 453 and the guide portion 452a. It is set to make. If β is set to 0, the relative movement direction of the reaction force device 405 and the back support rod 4 can be kept parallel to the relative sliding direction of the action portion 453 and the guide portion 452a. It can also be a certain value.

When β is set to 0, the reaction force adjusting mechanism 406 is initially engaged with the input / output unit 452 in the direction substantially perpendicular to the torsional direction of the elastic body 51 when the back support rod 4 is upright. Since the position is relatively variable, the elastic body 51 is hardly compressed at the time of adjustment, and the reaction force can be adjusted with a constant operation force by eliminating the influence of the repulsive force.

When β is set to a value other than 0, the reaction force adjusting mechanism 406 sets the action portion 453 in a direction that forms a predetermined angle β with respect to a direction substantially orthogonal to the twisting direction when the back support rod 4 is in the standing state. Since the relative movement is performed, it is possible to realize an operability that allows the elastic body 51 to be slightly displaced to feel the reaction force.

Also in this case, as the back support rod 4 tilts backward from the state of FIG. 25 toward the state of FIG. 27, the action portion 453 is on a circle P centered on the rear support shaft 25 as shown in FIG. In contrast, the input / output unit 452 moves on a circle R centering on the shaft 526 of the elastic body 51 and moves in different directions. Therefore, when the back support rod 4 is tilted backward, Similar to the first embodiment, the action portion 553 is displaced toward the distal end side of the input / output portion 552 and a relaxation characteristic is obtained from the middle.

Further, when the action portion 453 is adjusted in the direction toward the tip of the input / output portion 452, the repulsive force that enters and exits is small (that is, the moment arm r is long) and the force receiving body is the same as in FIGS. As the amount of elastic displacement (angle) φ at a position a unit distance away from the shaft 426 which is the center of displacement with respect to the amount of movement (kθ) of the back support rod is reduced, accumulation of repulsive force of the elastic body 51 is reduced. Therefore, when the acting portion 453 is adjusted in the direction toward the base end of the input / output portion 452, the repulsive force that enters and exits is large (that is, the moment) The arm r is short) and the elastic displacement amount (angle) φ is increased with respect to the same movement amount kθ of the back support rod 4, so that the repulsive force accumulation increases and is suitable for a high load receiving force ( High load receiving state), so the same wide range adjustment as in the first embodiment. Function so that the facilities.

As mentioned above, although several embodiment of this invention was described, the structure of each part is not limited to the example of illustration.

For example, if the engagement position of the action part on the input / output part changes with the tilting of the back support bar, it is not always necessary to make the initial engagement position of the action part variable when the back support bar is upright. is not. For example, as shown in FIG. 29, a structure is also included in which the action portion is fixed to a position where it integrally rotates with the back support rod. Therefore, the function of adjusting the back reaction force in a wide range with a small operation amount is not essential to the present invention.

Other configurations can be variously modified without departing from the spirit of the present invention. For example, the fixed portion in the first embodiment is configured to rotate the action portion around the support shaft by fixing the rotating body to the support shaft so as to be integrally rotatable. However, as another fixing portion, the drive gear is fixed. By doing so, the rotating body may be fixed in a stationary state, and thereby the action portion may be rotated around the pivot point. Even in this case, the distance from the support shaft of the back support rod to the action portion can be maintained within a certain range at the adjusted initial engagement position, and the action portion can be moved in conjunction with the back support rod. .

In addition, the input / output unit has a structure that best draws the operational effects of the present invention that is orthogonal or substantially orthogonal to the elastic displacement direction of the elastic body, but if at least crossed, the basic operational effects of the present invention are It is played.

The perspective view of the chair which concerns on 1st Embodiment of this invention. The partial top view. FIG. The principle diagram. The principal part expansion perspective view. The principal part expansion perspective view. The principal part enlarged plan view. FIG. FIG. FIG. The principal part enlarged view. The figure which shows the modification 1 of the embodiment. The figure which shows the modification 2 of the embodiment. The figure which shows the modification 3 of the embodiment. The principal part perspective view corresponding to FIG. Explanatory drawing corresponding to FIG. The graph which shows the effect | action of the same embodiment. The graph which shows the effect | action of the same embodiment. The sectional side view of the chair which concerns on 2nd Embodiment of this invention. The partial top view. FIG. The sectional side view of the chair which concerns on 3rd Embodiment of this invention. FIG. The perspective view of the chair which concerns on 4th Embodiment of this invention. FIG. The principal part enlarged view. FIG. The figure used for description of the said embodiment. The figure used for description of the said embodiment. The figure used for description of the said embodiment.

Explanation of symbols

4 ... Back support rod 51, 151, 251 ... Elastic body 52, 152, 252, 352, 452 ... Input / output unit 53, 153, 253, 353, 453 ... Action unit 5, 105, 205, 305, 405 ... Reaction force Device 6, 106, 206, 306, 406 ... First reaction force adjustment mechanism 8, 108, 208, 308, 408 ... Second reaction force adjustment mechanism

Claims (13)

The elastic body has an input / output unit that causes elastic displacement, and an operating part that moves together with the back support rod is engaged on the input / output unit, and is input by an operating force input from the back support rod through the operating unit. The output part moves or deforms to accumulate the repulsive force while elastically displacing the elastic body, and the back support rod is caused by the repulsive force output from the input / output part via the action part according to the elastic displacement of the elastic body. Comprising a reaction force device configured to be biased in a standing direction,
The reaction force device is configured such that when the engagement position of the action part on the input / output part is different, the magnitude of the repulsive force entering and exiting through the action part is different even if the elastic displacement of the elastic body is the same,
In accordance with the elastic displacement of the elastic body defined by the tilt angle of the back support rod and the engagement position of the action portion while changing the engagement position of the action portion on the input / output part with the tilt of the back support rod The chair is characterized in that the magnitude of the repulsive force that enters and exits from the input / output part via the action part is changed. The input / output portion and the action portion are set to move in different directions as the back support rod is tilted while maintaining the engaged state of the action portion of the back support rod with respect to the input / output portion of the reaction force device. The chair according to claim 1. If the engagement position of the action part does not change, the engagement position of the action part is changed with the backward inclination of the back support rod against the history that the elastic displacement of the elastic body follows according to the tilt angle of the back support rod. The chair according to claim 1 or 2, wherein the history is set so as to shift the history in a direction in which the elastic displacement decreases. The input / output unit is rotated or deformed around the center of displacement, and the action unit is rotated about an axis set at a position spaced from the center of displacement while maintaining the engaged state with the input / output unit. Item 3. The chair according to item 3. The reaction force device has an elastic body that accumulates the repulsive force by fixing one end and applying torsional force to the other end, and extends the input / output part from the other end in the direction crossing the torsional direction. As the back support rod tilts backward, the engaging part is displaced in the extending direction of the input / output part while moving the action part in the direction of twisting the elastic body through the input / output part. The chair according to claim 1. 6. A first reaction force adjusting mechanism that makes the initial engagement position of the action portion variable when the back support rod is standing is provided for the input / output portion extending from the other end of the elastic body. The listed chair. The chair according to claim 6, further comprising a second reaction force adjusting mechanism that can change a fixed position on one end side of the elastic body in a twisting direction of the elastic body. The reaction force device has an elastic body that accumulates a repulsive force by fixing one end side and applying a bending force to the other end side, and uses a surface intersecting with the bending direction of the elastic body as an input / output unit. As the back support rod tilts backward, the engaging part is displaced in the extending direction of the input / output part while moving the action part in the direction of bending and deforming the elastic body through the input / output part. The chair according to claim 1. A first reaction force adjustment mechanism is provided that makes the initial engagement position of the action portion variable when the back support rod is upright with respect to the input / output portion set on the surface intersecting with the bending direction of the elastic body. The chair according to claim 8. The chair according to claim 9, further comprising a second reaction force adjustment mechanism that makes the engagement depth with the action part variable in the bending direction of the elastic body through the extending angle of the input / output part. The reaction force device includes an elastic body that stores one repulsion force by fixing one end side and applying a compressive force or a pulling force to the other end side, and an input / output unit in a direction intersecting with the expansion / contraction direction from the other end side. Rotating operation is performed to extend or compress or pull the elastic body around the fulcrum, and the elastic body is compressed or pulled through the input / output section as the back support rod tilts backward. The chair according to claim 1, wherein the engagement position is displaced in the extending direction of the input / output unit while being moved in the direction. 12. A first reaction force adjustment mechanism is provided that makes the initial engagement position of the action portion variable when the back support rod is upright with respect to the input / output portion extending from the other end of the elastic body. The listed chair. The chair according to claim 12, further comprising a second reaction force adjusting mechanism that makes the fixing position of one end side of the elastic body variable in the compression or pulling direction.

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