JP2003009995A - Structure of attaching backrest board for chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of attaching a backrest board which allows to make an easy and accurate decision on a position in welding an attachment board to a back rod and is utilized for a chair with high weld strength. SOLUTION: The structure of attaching a backrest board is used for a chair with the backrest board 4 attached through the attachment boards 3 respectively provided on the back rods 2 extending from the right and left sides of a seat part to the backrest board 4. A groove 2a with a V-shaped cross section which opens on a side opposing to the other backrest bar is provided along the length to attach the attachment board 3 on the opposing sides of the both right and left backrest bars. A back surface 3a' at the end on the side of the backrest bar located on the attachment board 3 abuts on a back surface 2a' in the V-shaped groove 2a, and a front end surface 3b on the back rod side and a front surface 3a" at the end on the side of the backrest bar located on the attachment board 3 is welded to a front surface 2a" in the V-shaped, groove 2a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back plate mounting structure for a chair in which a back plate is mounted via mounting plates respectively provided on back rods extending from the left and right of a seat portion to the back plate.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, there has been known a back plate mounting structure for a chair in which a back plate is mounted on a back rod extending from the right and left of a seat portion to the back plate. Figure 6 (a)
Is a partial cross-sectional view showing a back plate attached to one of the back rods, and FIG. 6B is a side view thereof. Chair 0
The backrest of No. 1 is such that a mounting plate 03 made of a metal plate is welded to a back rod 02 extending from a seat formed by bending a metal pipe or the like, and the mounting plate 03 is slightly curved in a cross-sectional shape into an arc shape. It has a structure in which the back plate 04 is screwed.

The welding is, for example, welding using a welding machine, and in order to firmly fix the mounting plate 03 to the back rod 02, welding is performed from the front and rear of the mounting plate 03. Therefore, after welding, the backside welded portion 06a and the frontside welded portion 06b are in a raised state.

As shown in FIG. 6 (b), the screw fastening is
Screws 05 may be screwed into the upper and lower two positions from the back side of the mounting plate 03 to the nut portion 04a in which the female screw is previously cut on the back plate 04, whereby the back plate 04 is fixed to the mounting plate 03. .

[0005]

However, even in the back plate mounting structure of the chair 01 described above, the following problems to be solved remain. That is, when performing positioning before welding, the back rod 02 is, for example, tubular and the mounting plate 03
If the plate is plate-shaped, the alignment for the butting may become unstable, and temporary fixing welding may be troublesome.
The deviation of the mounting position due to the misalignment during positioning affects the accuracy of the screwing position after welding, and there is a possibility that the back plate 04 cannot be mounted on the mounting plate 03.

Further, since the contact area between the outer side surface of the back rod 02 and the mounting plate 03 at the time of welding is small, the welding strength is weak, and it is necessary to raise the welding portion to reinforce the welding strength. Therefore, the back welded portion 06a is exposed from the back side of the chair 01 and does not look so good. Moreover, when an external force acts on the back welded portion 06a and an external force acts, the back welded portion 06a may be cracked. There was also.

Further, as shown in FIG. 6 (a), in order to change the front position of the back plate 04 to a position flush with the tip of the back rod 02 shown by the broken line, the welding position of the mounting plate 03 is changed. Although it is conceivable that the back plate 02 is made thicker by changing the above, it is a labor-intensive work that increases the cost.

The present invention has been made in order to solve the above problems, and provides a back plate mounting structure for a chair which allows easy and accurate positioning when the mounting plate is welded to the back rod and has high welding strength. The purpose is to do.

[0009]

In order to achieve the above object, the back plate mounting structure in a chair according to the present invention includes mounting plates provided on the back rods extending from the left and right sides of the seat portion to the back plate. A back plate mounting structure in a chair to which a back plate is mounted, wherein a V-shaped groove having a cross section having an opening on the facing surface side is provided on the facing surface of the left and right back rods over the mounting length of the mounting plate.
The rear surface of the mounting plate on the side of the back rod is in contact with the rear surface of the V-shaped groove, and the front surface of the mounting plate on the side of the back rod and the front surface of the front end are the V.
It is characterized by being welded to the front surface of the groove. According to this feature, since the rear surface of the tip end portion of the mounting plate on the back rod side is in surface contact with the V-shaped groove, the mounting plate can be easily and accurately positioned when welding, and the welding position Since it is welded to the front surface of the V-shaped groove over a wide range including the end surface on the back rod side of the mounting plate, the welding strength is also high.

In the back plate mounting structure of the above chair,
The back rod is preferably formed of a hollow pipe.
With this configuration, if the back rod is a hollow pipe, the V-shaped groove can be easily formed by making a notch and pressing the V-shape.

In the back plate mounting structure of the above chair,
The welded region is preferably in the V groove. In this way, the welded portion is contained in the V-shaped groove, so that the welded portion cannot be directly seen from the outside, and V
Since it is surrounded by the groove, the welded part can be stored in a protected form.

In the back plate mounting structure of the chair,
It is preferable that a tip end portion of the attachment plate on the back rod side is integrally formed with a back plate joining portion to which the back plate is attached via a bent portion. With this configuration, even if a load is applied to the back plate, the load applied to the welded portion can be reduced due to the elastic deformation of the bent portion.

In the back plate mounting structure of the above chair,
It is preferable that the front position of the back plate can be adjusted according to the degree of bending of the bent portion. In this way, the front position of the back plate can be made flush with the position of the tip of the back rod, and a comfortable back seat position can be set according to the user's physique and taste.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the chair 1 to which the present invention is applied includes a support leg 12, a cylinder column 10, a seat 9, and two chairs extending upward from the left and right of the seat 9. The support rod 2 and the back plate 4 are provided, and casters 13 are attached to the lower ends of the five legs of the support leg 12. The cylinder support 10 supports the seat 9 and
It has a cylinder structure of, for example, a hydraulic / pneumatic type, and the expansion and contraction of the cylinder column 10 can be adjusted by operating the vertical adjustment device 11.

The backrest of the chair 1 is composed of a support tube 8, a pipe-shaped back rod 2 and a back plate 4, and one end of each of the two back rods 2 is made of a hard material which is provided horizontally from below the seat 9. The left and right ends of the support tube 8 made of metal are welded to each other and extend upward while partially curving, and the other end is attached with the back plate 4 via the attachment plate 3 (FIG. 2). .

Next, referring to FIG. 2 which is a rear view of the chair 1 and FIG. 3 which is a side view thereof, the structure of the chair will be described. The caster 13 supports a cylinder column 10 mounted on a movable support leg 12. In the seat portion 9, a cushioning material 9d such as a sponge is placed on a top surface of the seat plate 9c made of a material suitable for a seat material such as veneer plywood so as to be surrounded by the seat frame 9b, and the seat plate 9c is placed around the seat frame 9b. The seat 9 is assembled by stretching cloth or leather to form the seat surface 9a.

The base member 14 formed so as to wrap around the cylinder column 10 downward from the lower end surface of the seat portion 9 is
It is for holding the support tube 8, and is attached to the lower end surface side of the seat plate 9c by the attachment bolt 14a.

In order to attach the back plates 4 to the left and right back rods 2 and 2 attached to both ends of the support tube 8, the attachment plates 3 are welded to both back rods 2 and 2, respectively, and the back plate 4 is attached to the chair 1. After contacting the mounting plate 3 from the front side, the back plate 4 is mounted on the mounting plate 3 from the rear side of the chair 1 using the bolts 5.

5 is an exploded perspective view of the back plate mounting structure shown in FIG. 4 and a sectional view taken along the line AA in FIG.
The back plate mounting structure will be described in detail with reference to (a) and FIG. 5 (b), which is a partially broken view taken along the line BB of FIG.

On the opposing surfaces of the left and right back rods 2, mounting grooves 3a, which are recessed in a V-shaped cross section from the outer surface toward the inner side, are attached to the mounting plate 3 so that the facing surfaces are opened. It is provided over the length.

The V-shaped groove 2a is formed on the upper and lower sides of the back rod 2.
It suffices to provide cut slits 2b, 2b (FIG. 4) at required positions over a required length and press the V-shape between both slits. Particularly, if the back rod 2 is pipe-shaped, it is very easy to perform V-shape.
A groove can be formed.

To weld the mounting plate 3 to the V-shaped groove 2a, as shown in FIG. 5 (a), the rear surface 3a 'of the tip 3a of the mounting plate 3 on the back rod side is replaced with the rear surface 2a of the V-shaped groove 2a. 'With a welding tool. Welding is not limited to welding with a welding rod, and, for example, a laser welding method may be used.

The welded portion 6 welded by the welding tool includes the back rod-side tip surface 3b of the mounting plate 3 and the front surface 3 of the back rod-side tip portion 3a.
Since the a "is welded to the front surface 2a" of the V-shaped groove 2a, a large bonding area can be obtained and mounting with high welding strength can be realized.

Further, since the rear surface 3a 'of the back rod-side tip portion 3a of the mounting plate 3 is welded in a state of being in surface contact with the rear surface 2a' of the V-shaped groove 2a, the mounting plate 3 can be easily positioned with respect to the back rod 2. In addition to being accurate, the connection strength after welding is also large.

After welding the mounting plate 3 to the back rod 2, as shown in FIG.
As shown in (b), the two bolt holes 3c provided in the upper and lower portions of the mounting plate 3 and the nut portions 4a embedded in the upper and lower portions of the back plate 4 are positioned so as to overlap with each other, and the two bolts are attached. 5 (FIG. 5a) is inserted into the bolt hole 3c from the back side of the chair 1 and screwed into the nut portion 4a,
The back plate 4 is fixed to the mounting plate 3.

When the back plate 4 is attached, as shown in FIG. 5 (a), the welded portion 6 is surrounded by the side end portion of the back plate 4 and the V-shaped groove 2a so that it is almost invisible from the outside. Not only does it look good, but it is stored in the V-shaped groove in a form protected from the outside without being damaged or deteriorated by external force.

The mounting plate 3 is constructed by integrally forming a back rod-side front end portion 3a, a back plate joint portion 3d in which a bolt hole 3c is formed, and a bent portion 3e for connecting these two portions. When an external force is applied to the back plate 4, the portion 3e can elastically deform to reduce the load applied to the welded portion.

Further, since the front surface position of the back plate 4 can be changed by adjusting the bending degree of the bent portion 3e, the back plate 4 can be changed, for example, as shown in FIG. 5 (a).
It is also possible to make the front surface position of the front surface flush with the position of the front end portion of the back rod 2 and set a back plate position that is comfortable to sit in according to the physique and preference of the user.

After attaching the back plate 4 to the mounting plate 3,
The cap insertion portion 7a of the cap 7 is connected to the upper end portion 2c of the back rod 2.
Then, the end of the back rod 2 is processed by pressing it into the pipe.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific structure is not limited to these embodiments. For example, in the present embodiment, the back rod is considered in terms of lightness and workability. Although a pipe-shaped material is used, it may be a solid body. Further, the connection between the mounting plate and the back plate was a screw connection using bolts and nuts, but the invention is not limited to this, and any known connection means may be adopted. Although two separate members are used, one continuous pipe may be used, and any modifications or additions within the scope of the invention are included in the present invention.

[0032]

According to the present invention, the following effects can be obtained.

(A) According to the first aspect of the invention, since the rear surface of the tip of the mounting plate on the side of the back rod is in surface contact with the V-shaped groove, the mounting plate can be easily positioned when welding. The welding can be performed accurately, and since the welding portion is welded to the front surface of the V-shaped groove over a wide range including the end surface on the back rod side of the mounting plate, the welding strength is high.

(B) According to the second aspect of the invention, if the back rod is a hollow pipe, the V-shaped groove can be easily formed by making a notch and pressing the V-shape.

(C) According to the invention described in claim 3, since the welded portion is contained in the V-shaped groove, the welded portion cannot be directly seen from the outside and is surrounded by the V-shaped groove. Therefore, the welded part can be stored in a protected form.

(D) According to the invention described in claim 4, even if a load is applied to the back plate, the load applied to the welded portion can be reduced by the elastic deformation of the bent portion.

(E) According to the invention as defined in claim 5, it is possible to make the front surface of the back plate flush with the position of the tip of the back rod, depending on the physique and preference of the user. You can set a comfortable backboard position.

[Brief description of drawings]

FIG. 1 is a perspective view of a chair showing an embodiment of the present invention.

2 is a partially cutaway rear view of the chair of FIG. 1. FIG.

3 is a partially cutaway side view of the chair of FIG.

FIG. 4 is an exploded perspective view of the back plate mounting structure of the present invention.

5 (a) is a sectional view taken along line AA of FIG. (B) It is the figure partially broken as seen from the line BB of FIG.

FIG. 6 (a) is a partial cross-sectional view showing a back plate attached to a back rod of a conventional chair. (B) Similarly, it is a side view.

[Explanation of symbols]

1 chair 2 back rod 2a V-shaped groove 2a 'V-shaped groove rear surface 2a "V-shaped groove front 2b Notch slit 2c upper end 3 Mounting plate 3a Back rod side tip 3b Back rod end surface 3c bolt hole 3d back plate joint 4 backboard 4a Nut part 5 Volts 6 welds 7 cap 7a insertion part 8 Support tube 9 seats 9a Seat surface 9b Seat frame 9c seat plate 9d cushioning material 10 cylinder support 11 Vertical adjustment device 12 Support legs 13 casters 14 Base member 14a Mounting bolt

Claims (5)

[Claims] 1. A back plate mounting structure for a chair, wherein a back plate is mounted via mounting plates respectively provided on back rods extending from the left and right sides of the seat portion to the back plate, and the back plate mounting structure is provided on opposing surfaces of the left and right back rods. A cross-section V-shaped groove having an opening on the opposite surface side is provided over the mounting length of the mounting plate, and a back rod-side tip rear surface of the mounting plate abuts a rear surface of the V-shaped groove, and a back rod side of the mounting plate. A back plate mounting structure for a chair, characterized in that a front end surface and a front surface of the front end portion are welded to a front surface of the V-shaped groove. 2. The back plate mounting structure for a chair according to claim 1, wherein the back rod is formed of a hollow pipe. 3. The back plate mounting structure for a chair according to claim 1, wherein the welded region is in the V groove. 4. The chair according to any one of claims 1 to 3, wherein a back rod-side tip end portion of the mounting plate is integrally configured with a back plate joining portion to which the back plate is mounted via a bent portion. Back plate mounting structure. 5. The back plate mounting structure for a chair according to claim 4, wherein the front position of the back plate can be adjusted according to the degree of bending of the bent portion.