JP5954966B2 - Chair - Google Patents

Description

  The present invention relates to a chair characterized by a connecting structure between members.

In a chair , members are often connected by a shaft (pin). In particular, in a rocking chair, a shaft connection is an essential element in order to relatively rotate the members. Further, in a synchro-type chair in which the seat tilts backward in conjunction with the backrest when locking, there are many members that rotate relative to each other, and the number of connecting portions by the shaft increases.

Then, usually, when connecting the members together in axes, provided with a bearing portion of the cylindrical such that the round hole is vacant member connected, a shaft, a bearing hole in a longitudinal direction are moved member Although the insertion of the shaft is troublesome, the shaft is fixedly provided on the first member, and the second member is moved from the direction perpendicular to the shaft, It has been proposed to fit the bearings of the two members into the shaft. In this manner, the bearing portion of the second member is provided with a groove cut open in order to permit the fitting in the axial.

The example is disclosed by patent document 1, for example. In Patent Document 1, it is applied to connect the seat support frame to the base and back frame, the base and the back frame, while providing a bearing portion in which grooves are formed cut open above-facing opening, the seat support frame In addition, a horizontally long support shaft is integrally provided.

And, the slit groove of the bearing part is formed in a keyhole shape whose upper part is narrow, and by sliding the non-loop-shaped missing circle bush fitted into the support shaft into the slit groove, The support shaft is held in the bearing portion so as not to be detached. The cutout bush is made of a material that is elastically deformed, and the interval between the openings is smaller than the outer diameter of the shaft, and can be fitted into the shaft by pushing it wide.

JP 2008-194128 A

  Since the non-circular bushing of Patent Document 1 is inserted into the shaft after being expanded, there is a possibility that it will break too much. In particular, there is a concern that the risk of breakage increases in winter when the resin is difficult to deform.

  In addition, for some reason, it cannot be said that a person does not pull upward while holding the front end or rear end of the seat by hand, but in this case, the front or rear support shaft will be pulled upward, Then, it can be said that the slit of the bearing portion is expanded by the pulling of the support shaft, and as a result, the bearing portion is easily broken.

Furthermore, in Patent Document 1, since the outer periphery of the missing circle bush and the inner circumference of the bearing portion are merely arcs, the load due to the seating is applied to a narrow portion at the lower end of the missing circle bush and the bearing hole. If there is a high possibility of concentration, it is easy to wear out, and it is easy to cause partial reduction. As a result, it may be difficult to ensure high durability.

  The present invention has been made in view of such a situation, and an object thereof is to improve the connection strength while ensuring the speed of the connection operation.

The chair according to the invention of claim 1
“It has first and second members connected to each other so as to be rotatable relative to each other. The shaft is held by the first member, while the second member has an end of the shaft. A bearing part into which the part fits is formed, and the bearing part is formed with a slit groove that can be fitted by moving the shaft from a direction orthogonal to the axis . ''
In the basic configuration
" The slit groove of the bearing portion in the second member opens in a direction substantially orthogonal to the direction in which the second member rotates relative to the first member, and the second member A cylindrical bush that fits into the shaft is fitted into the bearing portion of the shaft from the outside, and is mounted.
And, a flat surface is formed on the inner peripheral surface of the bearing portion and the outer peripheral surface of the bush so as to overlap substantially from the front-rear direction.
The configuration of is added.

  In the present invention, the bush is cylindrical and is fitted into the bearing portion from the outside of the shaft, and is not expanded and deformed and fitted into the shaft. For this reason, it is not damaged by mounting on the bearing portion and is excellent in reliability. Moreover, since the bush of this invention is cylindrical and the inner periphery and outer periphery are continuing in the circumferential direction, it is excellent also in the bearing function.

  Now, for example, when the seated person leans against the backrest and the back frame tilts backwards and is held in a state where it cannot be tilted backward by the stopper, the back frame receives the action of rotating around the stopper. For this reason, a load in the same direction as the rotational direction of the back frame acts on the connecting portion of the back frame to the shaft. For this reason, when the slit groove is opened in the rotation direction of the back frame, as in Patent Document 1, the slit groove is subjected to the action of being widened and is likely to break.

  On the other hand, in the present invention, the slit groove opens in a direction orthogonal to the rotation direction (or the rotatable direction) of the second member such as the back frame. Even if a moment acts, the slit groove does not receive an expanding action, and as a result, a high connection strength can be secured.

In addition, when the configuration of the present invention is adopted, the pressing force due to locking is supported by a flat surface, so that the bushing is not partially reduced or stress is partially concentrated, and high durability can be obtained. it can.

It is an external view of the chair which concerns on embodiment, (A) is a perspective view, (B) is a side view. (A) and (B) are the separated perspective views of the main structural member of a chair. (A) is the isolation | separation perspective view of a seat outer shell , a base, and a back frame, (B) is the perspective view which looked at the base from the downward direction. It is a separated side view of a chair. It is a partial separation side view of a chair. (A) is a plan view of the base and the back frame, and (B) is an exploded perspective view for supporting the seat outer shell . FIG. 3B is a perspective view of the base, the back frame, and the seat outer shell, and FIG. 4B is a perspective view of the first shaft, the back frame, and the bush. Each of the drawings is a perspective view for illustrating a connection structure between the seat outer shell and the back frame. (A) is a longitudinal side view of the main part, (B) is a vertical front view of the main part.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description, to use the word "longitudinal", "lateral" to identify the direction, the front and rear left and right wording is based on the person seated. The front view direction is the direction facing the seated person, and therefore the left and right in the front view are opposite to the left and right viewed from the seated person.

(1). Outline of Chair First, an outline of a chair will be described mainly based on FIGS. This embodiment is applied to a swivel chair which are widely used in office and the like, as shown in FIG. 1, the chair, the leg device 2 having a leg support post 1 and casters, fixed to the upper end of the leg support post 2 The base 3, the seat 4 disposed on the base 3, and the backrest 5 on which a seated person can lean.

A resin seat outer shell (seat receiving member) 6 that supports the seat 4 is disposed on the base 3, and the seat 4 is attached to the seat outer shell 6. Seat 4 has a resin seat inner shell (seat plate), and a seat cushioning material disposed stacked on the top surface thereof.

As shown in FIG. 2, the base 3, the back frame 7 is coupled in a freely rear tilt by the first axis 8 made left and right horizontal pipes, this back frame 7, and the back outer shell 9 is mounted . As can be understood from FIG. 2, the back frame 7, the left and right side arms 10 extending substantially longitudinal direction, a rear portion 11 of the left and right horizontally long led to integrally at its rear end, rises from the rear end of the rear portion 11 back and a support portion 12, to the back support portion 12, the back outer shell 9 is mounted. A backrest 5 is attached to the back outer shell 9 and the back column portion 12. In FIG. 2A, the back inner shell 13 which is a main element of the backrest 5 is displayed.

As can be seen from FIG. 3, the front portion of the seat outer shell 6 is coupled with the base 3 by a second shaft 14 pipes made of, the rear of the seat outer shell 6, the third shaft which is provided on the back frame 7 15 is connected. As shown in FIG. 2B, the base 3 is covered with an upper cover 16 and a lower cover 17 from above and below. As shown in FIG. 3 (B), a column support cylinder 19 is welded to the rear part of the base 3, and the leg column 1 is fitted to the column support cylinder 19 from below.

Further, as shown in FIG. 3B, the first shaft 8 is fixed by welding to a portion in front of the support column 19 on the lower surface of the rear portion of the base 3. On the other hand, the front end portion 10 a of the left and right side arms 10 constituting the back frame 7 is a bearing portion connected to the first shaft 8. As shown in FIG. 3 , an arcuate recess 3 a into which the first shaft 8 is fitted is formed on the lower surface of the base 3. For this reason, the 1st axis | shaft 9 and the base 3 can ensure high joint strength by surface-contacting in a wide range, and being able to widen the space | interval of the welding build-up part. Of course, the first shaft 8 may be inserted through the base 3 instead of welding.

Then, a slit groove 20 is formed in the front end portion 10a of the side arm 10 so as to open forward, which is a direction orthogonal to the rotational direction of the side arm 10, as shown in FIG. , bearing hole 21 communicating with the cut open groove 20 is open to the left and right outward, the first bushing 22 is inserted from the outside in the axial receiving holes 21, fitting the first bush 22 from the outside to the first shaft 8 it allows the side arms 10, are connected in a freely rear tilt depending on the base 3 to the first axis 8. Therefore, the present invention is applied to a connecting structure using the first shaft 8 . Details thereof will be described later.

As shown in FIG. 2 (B) and FIG. 6, the second shaft 14 is fitted freely the longitudinal slide in a second bushing 23 mounted on the front of the seat outer shell 6. Thus, the side plate and the second bushing 23 of the base 3, is empty before and after the longitudinal oblong hole. Retraction of the second shaft 14 is elastically supported by coil type locking spring 24. Therefore, the second shaft 14, before the spring bearing 26 is fitted from behind.

  The locking spring 24 is received from the rear by a rear spring receiver 27. The rear spring receiver 27 is supported by a wedge body 29 that moves to the left and right by the rotation of the strength adjustment handle 28. It is supported by the front plate of the base bracket 36 disposed behind. The support bracket 19 penetrates the base bracket 36, and the support bracket 19 is also welded to the base bracket 36.

  The seat outer shell 6 is configured to receive the seat 4 in a wide area, and has a planar shape that is almost square. Then, for example, as shown in FIG. 6B, the front surface of the seat outer shell 6 is located on the front side of the lower surface of the base 3 and overlaps with the end of the second shaft 14 when viewed from the bottom. A front bearing portion 31 extending long in the front-rear direction is formed, and a bearing groove 32 into which an end portion of the second shaft 14 is fitted is formed on the inner surface of the front bearing portion 31 so as to open backward.

  Accordingly, after the second shaft is set on the base 3 in advance, the seat outer shell 6 is moved from the front to the back, and the front bearing portion 31 is fitted into the end portion of the second shaft 14, thereby allowing the seat outer The shell 6 can be pivotally connected to the base 3. Although not described in detail, the second shaft 14 and the front spring receiver 26 are fitted so as not to be laterally movable. Therefore, the second shaft 14 is positioned when the seat outer shell 6 is assembled.

As shown in FIG. 2B, the left and right side arms 10 constituting the back frame 7 are connected to a front and rear middle joint portion 33 with a horizontally long joint portion 33, and the third shaft 15 is integrally formed with the joint portion 33. Has been. Back frame 7 is a molded article of high performance engineering plastics such as glass fiber filled polyamide resin, the third shaft 15 is integrally formed to the joint portion 33. As well as a back frame 7 or fixed by welding the third shaft 15 as made of a metal such as aluminum die-casting, it is also possible to or formed integrally by insert molding. In any case, the left and right end portions of the third shaft 15 protrude to the left and right outer sides of the joint portion 33, while the rear bearing portion 34 that fits on the end portion of the third shaft 15 is provided at the rear portion of the seat outer shell 6. Is formed.

  The rear bearing portion 34 is set so as to protrude outwardly from the left and right sides of the third shaft 15. The rear bearing portion 34 has a slit groove 35 that opens toward the end of the third shaft 15, and the slit groove 35. A communicating hole 36 penetrating to the left and right is formed. Then, the rear bush 37 is fitted into the bearing hole 36 and the third shaft 15 from the left and right outer sides, whereby the rear portion of the bearing hole 36 is connected to the back frame 7 so as to be relatively rotatable. For example, as shown in FIG. 2B, the front bearing portion 31 and the rear bearing portion 34 of the bearing hole 36 are connected by a protrusion 6a, but may be completely independent.

(2). Connection structure with first shaft Next, details of the connection structure with the first shaft 8 will be described mainly with reference to FIGS. The connection by the first shaft 8 corresponds to the claims in which the base 3 corresponds to the first member and the back frame 7 corresponds to the second member. The first bush 22 is a molded product made of a resin having excellent wear resistance and a small friction coefficient, such as POM resin.

As described above, the front end portion 10a of the side arm 10 in the back frame 7 is formed with the slit groove 20 that opens forward and the bearing hole 21 that communicates with the slit groove 20 and opens left and right outward. Yes. The groove width of the slit groove 20 is set to be slightly larger than the outer diameter of the first shaft 8. In addition, a complete cylindrical portion 53 whose inner periphery is completely continuous is formed outside the slit groove 20 in the front end portion 10 a of the side arm 10. As best shown in FIG. 7, the portion of the full cylindrical portion 53 opposite are present inside plate 54, only the cut open groove 20 is formed in the inner plate 54. Therefore, the bearing hole 22 does not penetrate the entire left and right of the front end portion (bearing portion) 10a.

The bearing hole 21 has a wide portion 21a that is nearly trapezoidal in a side view, and a long groove 55 that extends in the left-right direction is formed on the inner surface of the wide portion 21a. An engagement hole 56 is formed as an example of the portion. On the other hand, the 1st bush 22 has the cylinder part 22a and the flange 22b located in the outer side, and the cylinder part 22a is block | closed by the flange 22b. A semicircular portion 57 and a wide portion 58 having a shape close to a trapezoid are formed in the cylindrical portion 22a so as to fit into the bearing hole 21 of the side arm 10 exactly. A rear engagement claw 59 is provided on the rear surface of the wide portion 58 to be engaged with the engagement hole 56 of the bearing hole 21 from the left and right inner sides.

For example, as shown in FIG. 8, more to the wide portion 58 of the first bush 22 is trapezoidal, the surface 58a after the wide portion 58 is flat surface. On the other hand, the rear surface 55a of the bearing hole 21 (and the slit groove 20) is also a flat surface with which the rear surface 58a of the wide portion 58 is in close contact, and the long groove 55 is formed on the flat rear surface 55a.

A front engagement claw 60 is formed on the front surface of the first bush 22 so as to be hooked and engaged with the inner end surface 22a of the slit groove 20 (for example, as shown in FIGS. 8A and 8B) , A front groove 21b is formed in the bearing hole 21 to allow movement of the front engaging claw 60). Therefore, in this case, the inner end surface 22a of the slit groove 20 corresponds to a locking portion. In addition, the first bush 22 has an inward opening 61 in which the end of the first shaft 8 is fitted . As shown in FIG. 6D , the flange 22b is prevented from becoming too thick. Ribs 62 for equalizing the thickness of the holes 61 are provided.

Connecting the back frame 7 of the base 3, first, the side of the front end of the arm 10 is fitted from behind both ends of the first shaft 8, then, the first bushing 22 bearing hole 21 from the outside, and the first shaft 8 fitted from the outside, it is performed in a very simple procedure of. In the fitting of the first bush 22, the engaging claws 59 and 60 engage the engaging Goana 56 and cut open groove 20 by return after once elastically deformed deformation. Thereby, the 1st bush 22 is hold | maintained so that removal is impossible.

  A rocking load acts on the first shaft 8 via the back frame 7, and this load acts mainly to push the first shaft 8 forward. And since the side arm 10 is opened to the front which is the direction opposite to the acting direction of the backrest load, the side arm 10 is not subjected to the action of the slit groove 20 being widened by the backrest load. For this reason, although it is a simple attachment structure, it has high support strength and safety.

  Further, since the rear surface 58a of the first bush 22 and the rear surface 55a of the bearing hole 21 are flat and overlap each other, the backrest load acts on the first bush 22 through the flat surface. The first bush 22 is not rotated by the backrest load. For this reason, the first bush 22 is not partially worn or stress is partially concentrated, and high durability can be maintained.

Now, in this embodiment, the maximum rearward tilt angle of the backrest 5 is regulated by the seat outer shell 6 hitting a stopper (not shown) provided on the base 3 in the same manner as a normal synchro-type chair. It has become. Accordingly, in a state in which the backrest 5 taken tilted backward, the back frame 7, acted as it is pivoted (moment) to the third shaft 15 as a fulcrum.

Accordingly, the front end portion 10a of the side arm 10 is stretched from the rear with respect to the first shaft 8 and also receives an action of being moved upward. However, the slit groove 20 is opened to the front, and the front end portion 10a of the side arm 10 is opened in a direction perpendicular to the direction in which the side arm 10 is to be rotated. Therefore, the slit groove 20 is expanded by a backrest load. I will not receive it. Therefore, high connection strength can be secured.

As in the present embodiment, when the complete cylindrical portion 53 having a continuous inner periphery is formed in the bearing portion such as the front end portion 10a of the side arm 10, resistance to an external force that deforms so as to widen the slit groove 20 is remarkably increased. The connection strength can be further increased. This is one of the advantages of this embodiment .

(3). Others The present invention can be embodied in various ways other than the above embodiment. For example, the bearing hole and the second bush may adopt a square cross-sectional shape such as a quadrangle or a hexagon. The bushing retaining means is not limited to the claw means, and screws and snap rings can also be employed. Shaft need not be integrated with the first member of the base, etc., or merely a state of just inserted, but it may also be or be retained so as not to escape by retaining member such as a snap ring.

The present invention may be embodied in the chair. Therefore, it can be used industrially.

4 seats 3 base (first member)
6 Seat outer shell 7 Back frame (second member)
8 First axis (Axis described in claims)
DESCRIPTION OF SYMBOLS 10 Side arm which comprises back frame 10a Front end part which is a bearing part 14 2nd axis | shaft 15 3rd axis | shaft 20 Notch groove 21 Bearing hole 22 1st bush 53 Complete cylinder part
54 Inner plate 55a, 58a flat surface

Claims (1)

The first member and the second member are connected to each other so as to be relatively rotatable with a shaft, and the shaft is held by the first member, while the second member has an end portion of the shaft. Is formed with a slit groove that can be fitted by moving the shaft from a direction perpendicular to the axis thereof.
The slit groove of the bearing portion in the second member opens in a direction substantially orthogonal to the direction in which the second member rotates relative to the first member, and the second member A cylindrical bush fitted to the shaft is fitted into the bearing portion from the outside of the shaft, and is mounted.
And on the inner peripheral surface of the bearing portion and the outer peripheral surface of the bush, a flat surface is formed that overlaps substantially from the front-rear direction.
Chair.

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