JP2000120627A - Frame connecting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have the sufficient strength at a projecting and a recessed fitting parts even in the case where a bonding surface for fitting a frame to a base body is small by forming a fitting screw so as to be screwed through a projecting and a recessed fitting parts provided for positioning. SOLUTION: At the time of fitting an arm 6 to a support main body 11, a backing member 9 is inserted into the support main body 11 from an end thereof. A pin 62 is fitted in a fitting hole 111, and a fitting screw is inserted into a screw insertion hole 61 from a tip side of the arm 6 in the condition that the arm 6 is positioned in relation to the support main body 11, and screwed for fastening with a screw hole 91 provided in the backing member 9. The arm 6 is fixed to the support main body 11 by this fastening force while being positioned by the backing member 9 and a base end surface 6a of the arm 6. With this structure, since the fitting screw passes through the inside of the projecting and recessed fitting parts, projection and recess of the projecting and recessed fitting parts are necessarily formed larger than the diameter of the fitting screw, and especially, the sufficient strength can be naturally given to the projection.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for connecting members, and more particularly to a structure for connecting frames constituting a desk or the like.

[0002]

2. Description of the Related Art Conventionally, when members are connected to each other in an accurate positional relationship, a pin and a concave portion that fits the pin are provided on a joint surface of each member, and the pin and the concave portion are fitted to each other so that the members can be mutually connected. After the mounting position is determined, a structure in which members are connected to each other by mounting screws or the like is often adopted.

For example, in a desk or the like having a structure in which a top plate is supported by a support constituted by connecting a plurality of long members, a frame is required if the frames are not accurately positioned and connected. Since the entire body may be distorted and hinder assembly, the frames are positioned and connected using the structure.

[0004]

However, in such a case, since the end face of the frame must be joined to another frame, it is difficult to increase the area of the joint face. If an insertion hole or screw hole for inserting or screwing the mounting screw is opened, and a positioning pin or a concave portion that fits into this is provided, the pin can be made thinner due to the limitation of the joint area. I have to help. As a result, there is a possibility that the pin may be broken when the frame is attached or when an unexpected external force acts after the attachment. In addition, in order to avoid such a problem, measures such as enlarging the outer shape near the joint surface on the frame side to increase the joint area may cause a problem that an inexpensive extruded product cannot be used for the frame. .

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a frame connecting structure for connecting a frame and a base so that an end face of the frame faces the base and is provided for positioning. With the configuration in which the mounting screw is screwed through the uneven fitting portion, the uneven fitting portion can have sufficient strength even if the area of the joining surface for mounting the frame to the base is small. The main purpose is to do so.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A frame connecting structure according to the present invention connects a frame and a base using mounting screws so that an end face of the frame faces the base. Positioning means including an uneven fitting portion is provided between the frame and the base for positioning with respect to the base, and a mounting screw is screwed through the uneven fitting portion.

In such a case, since the mounting screw penetrates the inside of the concave and convex fitting portion, the projections and concave portions constituting the concave and convex fitting portion are necessarily larger than the diameter of the mounting screw. Sufficient strength can be reasonably imparted to the concave and convex fitting portions, particularly to the projections. In addition, since the concave-convex fitting portion and the mounting screw are in a superimposed state, the present invention can be applied to those having a small joint area at the connecting portion.
Furthermore, as a result, measures such as enlarging the outer shape of the base end on the frame side, which were conventionally performed to increase the joint area, are not required, and an inexpensive extruded product having a constant cross-sectional shape can be used for the frame. Become like

In order to realize a more flexible connection, for example, the direction of connection of the frame to the base can be easily changed without changing the shape of the frame or the base, the base and the frame are connected via an arm. In such a configuration, it is preferable that the positioning means is constituted mainly by the arm, and the concave and convex fitting portion is formed between the base end face of the arm and the base.

As a specific embodiment in consideration of simplification of assembly and operability of screwing of a mounting screw, a base and a frame are both formed of a pipe member, and an uneven fitting portion is formed by an arm. Is formed by fitting a projection protruding from the base end face of the base with a recess formed to penetrate the outer wall of the base, and a screw insertion hole for inserting a mounting screw is inserted through the projection. Along with the provision, a backing member having a screw hole is inserted into the inner periphery of the base, and the mounting screw having the screw insertion hole and the recess inserted therein is screwed and tightened to the backing member, whereby the arm is provided. One that is attached to the frame such that the outer wall of the frame is sandwiched between the base end surface and the backing member.

In order to use an inexpensive and easily manufactured member such as an extruded product for the arm, it is desirable that the projection and the arm are formed separately. As a specific embodiment in such a case, a protrusion is formed by inserting a cylindrical pin having a screw insertion hole formed along the axis thereof into a pin insertion hole having a predetermined depth opened at the base end surface of the arm. It is preferable that the arm is inserted and its distal end projects from the base end surface of the arm.

In order to allow a plurality of frames to be connected in different directions from the base with one backing member, recesses are provided in a plurality of outer walls of the base in different directions, respectively. Is preferably provided with an abutting portion that abuts on the inner surfaces of the plurality of outer walls, and is preferably configured so that a plurality of arms can be bonded to one base from different directions.

In order to reduce the number of members and improve the appearance, it is preferable to integrally provide a backing member with a lid for closing the end surface of the base.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a desk to which the connection structure according to the present invention is applied. This desk, as shown in FIG.
The upper ends of the leg posts 1 are connected via a frame 2, and the frame 2 supports the top plate 3.

The leg post 1 is a column main body 11 which is a square pipe having a square cross section formed by extruding aluminum or the like, a cover body 14 fitted to the column main body 11 and a bottom surface of the column main body 11. It is composed of an adjuster portion 12 provided and a lid 13 for closing the upper end surface of the support body 11, and is provided with the upper end opposed to the four corners of the rectangular top plate 3 or the lower surface in the vicinity thereof. You.

The frame 2 is composed of a pair of side frame members 21 connecting the opposing surfaces near the upper ends of the front and rear leg posts 1 along the depth direction, and the upper ends of the left and right leg posts 1 disposed at the rear end side. Rear frame member 22 that connects the opposing surfaces in the vicinity along the width direction
And a reinforcing frame member 23 that connects the opposing surfaces slightly behind the center of the left and right side frame members 21 along the width direction. The support S having the property is constituted. Each of the frame members 21 and 22 has a square pipe shape obtained by cutting a common extruded body made of a rigid material such as aluminum into a required length as shown in a cross section in FIG. The grooves 21a and 22a are opened, and the pair of inner walls 21b and 22b are formed symmetrically between the upper wall and the bottom wall.
The reinforcing frame member 23 is the same as the frame members 21 and 22 except that rail grooves 23a are opened on both sides.

The top plate 3 has a top plate supporting bracket 4 attached to the front and rear side frame members 21 at two locations before and after using the rail grooves 21a, respectively, and a rail groove 23a at the center of the reinforcing frame member 23. Is mounted on the top plate support fitting 4 attached thereto, screwed from below and fixedly supported. The top plate 3 is formed by stacking a large number of top plate materials in the depth direction so that the wood grain appears in the width direction. Even if it is only supported, a high strength can be exhibited with respect to the overhead load.

In this embodiment, in the present embodiment, the column body 11 and the frame members 21 and 22 or the left and right side frame members 2 are used in this embodiment.
1 and the reinforcing frame member 23 are connected using connection structures 5, 5A described below. The connecting structure 5 is a use end side of a desk,
In addition, the present invention is applied to the connection between the column body 11 serving as the base and the frame members 21 and 22 serving as the frame at the upper corner portion on the non-use end side. The connection structure 5 at the upper corner portion on the non-use end side will be typically described. As shown in FIGS. 2, 3, and 4, the connection structure 5 cuts an extruded product such as aluminum into a predetermined length. A first connecting portion 7 for joining the arm 6 having the I-shaped vertical cross section to the outer wall 11a of the column main body 11, and an arm 6 joined to the column main body 11
And a second connecting portion 8 for externally fitting and fixing the side frame material 21 or the rear frame material 22 to the support body 1 by positioning means mainly constituted by the arm 6.
1, the frame members 21 and 22 can be connected while being positioned.

The first connecting portion 7 is a component of the positioning means as shown in FIGS. 2 and 4, and includes an uneven fitting portion 71 for positioning the joint position of the arm 6 with respect to the support body 11, And a fixing portion 72 for fixing the arm 6 to the support body 11. The concave / convex fitting portion 71 includes a pin 62 that forms a columnar protrusion protruding from the base end surface 6 a of the arm 6 so as to form a pair up and down, and the outer wall 1 of the support body 11.
The pin 62 is formed through fitting with a pair of recessed fitting holes 111 which are provided to penetrate the upper end portion of the first hole 1a and which can fit the pins 62 almost without any gap. On the other hand, the fixing portion 72
Is a screw hole 91 of the backing member 9 in which the mounting screw 10 inserted through the screw insertion hole 61 and the fitting hole 111 penetrating along the longitudinal direction of the arm 6 is inserted into the inner periphery of the column body 11. The backing member 9 and the base end surface 6a of the arm 6 form an outer wall 1
The arm 6 is fixed to the column main body 11 by pressing the portion 1a. As shown in FIG. 5, the backing member 9 is a substantially solid prism that is integrally hung from a lid 13 that closes the end surface of the column main body 11. Fit with almost no gap. On the three side surfaces 9a, which are the contact portions of the backing member 9,
A screw hole 91 having a counterbore 92 is opened. In each side surface 9a of the opening of each screw hole 91, the pin 6
2 or screw holes 91 are provided in pairs corresponding to the fitting holes 111.

In the present embodiment, as shown in FIG. 4, one end of each screw insertion hole 61 is opened at the tip end face 6b of the arm 6, and the other end is opened at the tip end face of the pin 62.
That is, this screw insertion hole 61 penetrates the pin 62,
The pin 62 surrounds the periphery of the opening of the screw insertion hole 61.
Is formed. Also, the pin 62
It is opened in the base end face 6a of the arm 6, and is press-fitted into a pin insertion hole 66 having a predetermined depth, that is, a depth such that the distal end of the pin 62 can protrude to form a projection. Pin insertion hole 6
6 has a larger diameter than the screw insertion hole 61 provided on the arm 6 side, and is formed so that its axis coincides with the screw insertion hole 61. As described above, by forming the pin 62 separately from the arm 6, an inexpensive extrusion member can be used for the arm 6.

The method of attaching the arm 6 to the column body 11 is as follows. First, the backing member 9 is attached to the support body 11.
And into it from its end. Then, with the pin 62 fitted in the fitting hole 111 and the arm 6 positioned with respect to the support body 11, the mounting screw 10 is inserted into the screw insertion hole 61 from the distal end side of the arm 6, and the backing member 9 is screwed and tightened. With this tightening force, the outer wall 11 of the column body 11 is formed by the backing member 9 and the base end surface 6 a of the arm 6.
a is clamped, and the arm 6 is positioned and fixed to the column main body 11. In such a state, the head 10a of the mounting screw 10
Is pressed against the distal end surface 6b of the arm 6, but the distal end shape of the arm 6 is set so that the head 10a does not protrude laterally beyond the arm distal end surface 6b. This will be described later.
0a does not interfere.

As shown in FIGS. 3, 4 and 6, the second connecting portion 8 is provided with an arm 6 attached to the support body 11.
For fixing the frame members 21 and 22 to each other, and includes a fixing portion 82 and a taper engaging portion 81 which is a component of the positioning means. The fixing portion 82 allows the screw holes 63 opened at two positions on the side surface of the arm 6 to pass through the insertion holes 21 e provided at the positions corresponding to the screw holes 63 on the inner wall 21 b inside the side frame member 21. The screw B is formed by screwing and tightening the countersunk screw B. The taper engagement portion 81
Tapered surfaces T1 and T2 are provided on the inner surface of the inner wall 21b inside the side frame member and on the side surface of the arm 51 so as to be inclined so as to expand and contract along the tightening direction of the countersunk screw B. It is formed by taper engagement.

By the second connecting portion 8, the frame members 21, 2
2 is externally fitted to each arm 6, and its end surface is brought into contact with the outer wall 11 a of the column body 11, and then a countersunk screw B is screwed and fixed. Thus, on the non-use end side of the desk described above, the arm 6 extends from the column body 11 in two orthogonal directions so that the rear frame member 22 and the side frame member 21 can be connected to the column body 11. On the use end side of the desk, as shown in FIG. 1, the arm 6 extends only in one direction from the column main body 11 so that only the side frame member 21 can be connected to the column main body 11. In this embodiment, the support body 11 and the backing member 9 are used.
Are square in cross section, and three side surfaces 9a of the backing member 9
Since the screw holes 91 are respectively opened, only by changing the fitting direction of this one type of backing member 9 (lid 13), all the left and right sides of the desk use end side or the non-use end side are used. It is possible to cope with the connection between the frame members 21 and 22 and the support body 11 at the upper corner portion.

The connection structure 5A applied to the connection between the reinforcing frame member 23 and the side frame member 21 joins the arm 6 having the same shape to the side frame member 21 as shown in FIGS. Connecting portion 7A for fixing the reinforcing frame member 23 to the arm 6 joined to the side frame member 21 by external fitting.
(The reinforcing frame member 23 is not shown in FIG. 7).

The first connecting portion 7A is connected to the side frame member 2 of the arm 6.
The arm 6 includes a concave-convex fitting portion 71A for positioning the joining position with respect to the first frame 1 and a fixing portion 72A for fixing the arm 6 to the side frame member 21. The concave / convex fitting portion 71A includes a pair of pins 62 protruding from the base end surface 6a of the arm 6,
Partially circular cutout portion 211 serving as a pair of concave portions provided so as to face the opening edge of rail groove 21 a of side frame member 21.
Formed by fitting. On the other hand, the fixing portion 72A has a screw insertion hole 61 penetrating along the longitudinal direction of the arm 6.
Into the inner wall 21b of the side frame member 21.
Formed by screwing and tightening into a screw hole 91A of a backing member 9A inserted between the outer back wall member 21A and the outer wall 21c.
The arm 9A is fixed to the side frame member 21 by pressing the outer wall 21c of the side frame member 21 between the backing member 9A and the base end surface 6a of the arm 6. The backing member 9A has a rectangular plate shape,
Screw hole 91 having a counterbore 92A to correspond to
A is provided in pairs up and down. In the same manner as described above, one end of each screw insertion hole 61 is opened at the distal end surface of the arm 6, and the other end is opened at the distal end surface of the pin 62. Also, the pin 62 is press-fitted into a pin insertion hole 66 which is open in the base end face 6a of the arm 6 and has a depth such that the distal end of the pin 62 protrudes to form a projection.

The method of attaching the arm 6 to the side frame member 21 is as follows. First, the backing member 9A is inserted between the inner wall 21b and the outer wall 21c from the end face of the side frame member 21 and slid to a predetermined position. Then, insert the pin 62 into the notch 2
11 and the arm 6 is positioned with respect to the side frame member 21, the mounting screw 10 is inserted into the screw insertion hole 61 from the distal end side of the arm 6, and the screw hole 91A provided in the backing member 9A. Screw tightly. With this tightening force, the outer wall 21 of the side frame member 21 is formed by the backing member 9A and the base end surface 6a of the arm 6.
c is pressed, and the arm 6 is accurately fixed to the side frame member 21. In such a state, the head 10a of the mounting screw 10 is
As described above, the head 10a does not protrude laterally beyond the arm end surface 6b.

Since the second connecting portion 8A has exactly the same structure as the second connecting portion 8 in the connecting structure 5, the description is omitted. According to the connecting structures 5 and 5A, the pins 62 and the recesses 111 and 211 constituting the concave and convex fitting portions 71 and 71A are provided.
Since the mounting screw 10 penetrates through, the outer diameter of the pin 62 can be greatly increased as compared with the conventional one even if the joint area at the connecting portion between the arm 6 and the column body 11 or the side frame member 21 is small. As a result, sufficient strength can be imparted to the pin 62 without difficulty. Further, the base end face 6 of the arm 6
If the pin 62 is formed by processing only the a
Thus, an inexpensive extruded product having a constant cross-sectional shape can be used.

Further, since the column body 11 and the frame members 21 and 22 or the side frame member 21 and the reinforcing frame member 23 are connected via the arm 6, the column body 11 and the frame members 21, 22, and 2 are connected.
Inexpensive extruded products can also be used for 3, and the manufacturing cost can be reduced. In addition, the support body 11 and each frame material 2
Since the arms 1, 2, and 23 are pipe members, and the arm 6 is attached using the backing member 9 inserted into the inner periphery of the pipe member, the arm 6 can be formed in the same shape, and standardization of parts can be achieved. Not only can this be achieved, but also the simplification of assembly and the operability of screwing the mounting screw 10 can be improved.

On the other hand, by bending the arm 6, it is possible to easily change the connection direction without changing the shapes of the column body 11 and the frame members 21, 22, and 23. This is shown in FIGS. 9 and 10. FIG. In the above-described embodiment, the arm 6 has a linear shape extending perpendicularly from the column main body 11 or the side frame member 21. However, in this modification, the arm 6B is bent halfway, It is made to extend diagonally. This arm 6
B comprises an arm body 64B and a base end 65B. The arm main body 64B has the same I-shaped cross section as in the above embodiment, and the arm main body 64B has frame members 21, 22, 2,
3 can be fitted externally. On the other hand, the base end portion 65B has a bent shape in the middle, and its outer diameter is set to
1, or the same as the frame members 21, 22, and 23. Then, the base end surface 6aB of the base end portion 65B is brought into close contact with, for example, the outer wall 11a of the column main body 11, and is connected in the same manner as in the above embodiment. Since the base end portion 65B is bent in the middle, one end of the screw insertion hole 61B is opened on the side surface of the arm body 64B.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible. For example, FIG. 11 shows a modification of the backing member. The backing member 9C is provided integrally with the lid 13, and has screw holes 91C opened on two opposing side surfaces. Further, a screw hole may be provided on the pin side and a screw insertion hole may be provided on the backing member. The pin is not limited to a columnar shape. For example, if the pin has a conical shape whose diameter gradually decreases in the protruding direction, it is easy to fit the concave portion and more accurate positioning can be obtained. Can be. Further, the pin does not need to be fixed to the arm, and may be configured to be fitted into the pin insertion hole without any gap so that it can be inserted and removed. In addition, in the above-described embodiments and the like, the frame material serving as the frame is connected via the arm. However, even when the frame is directly positioned and connected to the base body, the main connection that allows the mounting screw to penetrate the concave / convex fitting portion is provided. Structure can be applied. Of course, the present invention can be applied not only to a support constituting a desk, but also to a portion connecting frames such as shelves and chairs to achieve a similar effect.

In addition, the configuration of each section is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0031]

As described in detail above, according to the present invention,
Since the mounting screw will penetrate the inside of the uneven fitting part,
The protrusions and recesses constituting the concave-convex fitting portion are necessarily larger than the diameter of the mounting screw, and sufficient strength can be easily imparted to the concave-convex fitting portion, especially the projection. Moreover,
Since the concave and convex fitting portion and the mounting screw are in a superposed state, it can be applied to those having a small joint area at the connecting portion. Furthermore, it is no longer necessary to take measures such as enlarging the outer shape of the base end of the frame, which has been conventionally performed to improve the strength of the protrusion, and it is possible to use an inexpensive extruded product having a constant cross-sectional shape for the frame. .

In the structure in which the base and the frame are connected via the arm, the positioning means is mainly constituted by the arm, and the concave / convex fitting portion is provided between the base end face of the arm and the base. As long as it is formed in various shapes such as a bent arm only, without changing the shape of the frame or the base,
A more flexible connection can be easily realized, for example, the connection direction of the frame to the base can be easily changed, and such a connection structure can be made optimal according to the application location.

Each of the base and the frame is formed of a pipe member, and the concave / convex fitting portion is formed by fitting a protrusion protruding from the base end face of the arm with a concave formed through the outer wall of the base. A screw insertion hole for inserting a mounting screw is provided so as to penetrate the projection, and a backing member having a screw hole is inserted into the inner periphery of the base, and the screw is inserted. The arm is joined to the frame such that the outer wall of the frame is sandwiched between the base end surface and the backing member by screwing and tightening the mounting screw inserted through the insertion hole to the backing member. If you have
It is possible to simplify the assembly and improve the operability of screwing the mounting screws.

If the projection and the arm are formed separately, an inexpensive and easily manufactured member such as an extruded product can be used for the arm. The projection inserts a cylindrical pin having a screw insertion hole formed along the axis thereof into a pin insertion hole having a predetermined depth opened in the base end face of the arm, and the distal end thereof is inserted into the base of the arm. As long as it protrudes from the end face, even if the protrusion and the arm are formed separately, the production and the process are not complicated.

A concave portion is provided on each of a plurality of outer walls of the substrate facing in different directions, and the backing member is provided with an abutting portion which is in contact with the inner surfaces of the plurality of outer walls. The plurality of arms are configured to be connectable from different directions respectively. With one backing member, the plurality of frames can be connected to the base so as to extend in different directions.

In order to reduce the number of members and to improve the appearance, it is preferable to integrally provide a backing member with a lid for closing the end face of the base.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is an overall perspective view of a desk to which a connection structure is applied.

FIG. 2 is an exploded perspective view mainly showing a connection structure 5 in the embodiment.

FIG. 3 is an exploded perspective view mainly showing a connection structure 5 in the embodiment.

FIG. 4 is a partial longitudinal sectional view showing a connection structure 5 in the embodiment.

FIG. 5 is a plan view showing a backing member in the embodiment.

FIG. 6 is a longitudinal sectional view showing an arm and a side frame member in the embodiment.

FIG. 7 is an exploded perspective view mainly showing a connecting structure 5A in the embodiment.

FIG. 8 is a partial longitudinal sectional view showing a connecting structure 5 in the embodiment.

FIG. 9 is an exploded perspective view showing a modification of the present invention.

FIG. 10 is a transverse sectional view in FIG. 9;

FIG. 11 is a plan view showing a backing member according to another modification of the present invention.

[Explanation of symbols]

 5, 5A ... connecting structure 6, 6B ... arm 9, 9A ... backing member 9a ... attaching part 10 ... mounting screw 11 ... pillar body (base) 11a, 21c ... outer wall 13 ... lid 21 ... side frame material ( 22) Rear frame member (frame) 23 ... Reinforcement frame member 61, 61B ... Screw insertion hole 62, 62B ... Pin (projection) 71, 71A ... Concavo-convex fitting part 111 ... Fitting hole (recess) 211 ... Notch (recess)

Claims (7)

[Claims] A frame and a base are connected by using mounting screws so that an end face of the frame faces the base, and the frame and the base are positioned between the frame and the base to position the frame with respect to the base. A frame coupling structure, comprising: a positioning means including a concave-convex fitting portion, wherein the mounting screw is screwed through the concave-convex fitting portion. 2. The apparatus according to claim 1, wherein the base is connected to the frame via an arm, wherein the positioning means is formed mainly of the arm, and the concave / convex fitting portion is formed between the base end face of the arm and the base. 2. The frame connection structure according to claim 1, wherein the frame connection structure is formed between the frames. 3. The base and the frame are each formed of a pipe member, and the concave / convex fitting portion includes a protrusion protruding from a base end surface of the arm and a recess formed through the outer wall of the base. A screw insertion hole for inserting a mounting screw is provided so as to penetrate the projection, and a backing member having a screw hole is inserted in the inner periphery of the base, By screwing and tightening the mounting screw through which the screw insertion hole and the recess are inserted into the backing member,
The frame connecting structure according to claim 2, wherein the frame connecting structure is attached to the frame such that an outer wall of the frame is sandwiched between the base end surface and the backing member. 4. The frame connecting structure according to claim 3, wherein the projection and the arm are formed separately. 5. A cylindrical pin having a projection formed with a screw insertion hole along the axis thereof is inserted into a pin insertion hole having a predetermined depth opened at a base end face of the arm, and the tip of the pin is inserted into the pin insertion hole. The frame connecting structure according to claim 4, wherein the portion is formed to protrude from a base end surface of the arm. 6. A substrate, wherein a plurality of outer walls facing the different directions of the base are provided with recesses, respectively, and the backing member is provided with an abutting portion for abutting the inner surfaces of the plurality of outer walls. 4. The apparatus according to claim 3, wherein the plurality of arms are configured to be joined from different directions.
Or the frame connection structure according to 5. 7. A backing member integrally provided on a lid for closing an end surface of a base body.
The desk according to 4, 5 or 6.