JP2022176734A - Connector of square pipe and joint therefor - Google Patents

Abstract

To provide a connector of a square pipe, capable of obtaining a connection fixed state which is enhanced in the endurance strength between the square pipes and stability.SOLUTION: A joint (J) which is interposingly set to a connection part between square pipes (P) comprises: a joint main body (A) which is formed into a closed cross section having a substantially-X shape as a whole; and a pair of fore-and-aft hexagon socket head cap bolts (B) which are assembled to an intermediate position of the joint main body in an applicative/horizontal bridged-connection state. By operably turning the bolts (B) from the outside of the square pipe, and moving left-and-right opposing both side faces (13L), (13R) of the joint main body (A), the joint main body is elastically deformed so as to be expanded in its inside hollow part as a whole, and circular arc protrusive curved faces (14) of four corner parts are made to press four angular parts corresponding to the square pipe so as to stretch them from the inside.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a device for connecting square pipes having a rectangular cross section in series, and a joint for square pipes therefor.

Patent Documents 1 to 3 disclose a structure in which rectangular pipes having a rectangular cross section are connected in a straight line by inserting a joint serving as a core.

Among them, the pipe joint (B) described in FIGS. 3 and 4 of Patent Document 1 rotates the bolts (2) (2) from the outside of the double-sided pipes (7) (7) to The abutting pieces (1)(1) are moved in the direction of relatively approaching and separating, and the tip edges (11)(11) of the abutting pieces (1)(1) are connected to the square pipes (7)(7). The square pipes (7) (7) are connected and fixed to each other by pressing the square pipes (7) (7) against the corners of the pipes from the inside.

JP-A-8-68405 Japanese Patent No. 3877868 JP 2007-170564 A

However, in the structure of the pipe joint (B) disclosed in Patent Document 1, the pipe inner surface contact pieces (1) and (1) are bent from a plate material, and a separate pair (two pieces) thereof Since the corners of the square pipes (7) and (7) are pressed separately, the ridges of the tip edges (11) (11) of the contact pieces (1) (1) are aligned with the square pipe (7). ) In addition to the fact that the corners of (7) are only in contact with each other as a single line, the strong pushing force from the inside against the corners of the square pipes (7) (7) is The pieces (1)(1) cannot be exerted, and the thrust pressing force cannot be exerted equally to the pair of contact pieces (1)(1).

As a result of dispersing the thrusting pressure force from the inside by the pair of contact pieces (1) (1), the square pipes (7) (7) can be used, for example, as a guide rail for running a feeder in a poultry house or for construction work. When the square pipes (7) (7) are used as temporary scaffolding, etc., if the square pipes (7) (7) are repeatedly subjected to loads and vibrations from the outside, the contact pieces (1) (1 ) may deform improperly, cause rattling, or cause a step at the joint between the square pipes (7) (7). Unable to get connection fixed state.

The abutting pieces (1) and (1) are made of plate material, and since they are separate and independent as a pair (two pieces), external pressure applied from a direction orthogonal to the axis of the bolts (2) and (2) Since the resistance to the load is weak and the bolts (2) (2) are useful for exerting the resistance, it is necessary to keep the bolts (2) (2) in a vertical position as shown in Figs. 3 and 4. There are restrictions on how to use and use the pipe joint (B).

Further, the abutment pieces (1) and (1) are bent from a plate material into a pseudo-isosceles trapezoid, and when a pair (two pieces) of the abutment pieces (2 pieces) are in a back-to-back state, one (upper side in FIGS. 3 and 4) The abutting piece (1) is screwed with the threaded shafts of the bolts (2) (2) in the screw holes (14) (14), but the remaining other (similarly the lower side in FIGS. 3 and 4) abuts. The contact piece (1) is only in contact with the tip (lower end) of the bolt (2) (2) at the central connecting plate (13) (13) (claim 3 and paragraph [ 0030]), not pre-assembled with its bolts (2)(2).

In this way, the fact that the other contact piece (1) is not assembled with the bolts (2) (2) is also a strong resistance against external forces such as loads and vibrations applied from the outside of the square pipes (7) (7). It causes the inability to exercise power.

Moreover, the one (upper) contact piece (1) screwed with the bolts (2) and (2) and the remaining (lower) contact piece (1) are separated from each other. Because of this state, the pipe joint (B) in such a state cannot be quickly and accurately inserted into the double-sided pipes (7) (7). When inserting and setting as the core, it is difficult to keep the pair of contact pieces (1) (1) in an accurate back-to-back facing state, and the positional displacement of the square pipes (7) (7) along the longitudinal direction. is inevitable, and workability (workability) is inferior.

The object of the present invention is to completely solve such problems. A device connected in a straight series state by a joint,
The above joint is

a joint body shaped to have an overall substantially X-shaped closed cross-sectional shape in which both the upper and lower surfaces and the left and right surfaces are recessed in a substantially V-shaped groove, and all four corners form arcuate convex curved surfaces;

A pair of front and rear parallel bolts assembled in an active bridging connection state between the upper and lower surfaces facing each other or between the left and right side surfaces facing each other in the joint body,

Rotate the bolts clockwise from the outside of the square pipes to be connected to rotate either one of the upper and lower surfaces facing each other or either of the left and right side surfaces facing each other in the joint body relative to the remaining other. If you move it in the direction of approaching,

Due to the expansive elastic deformation that spreads over the entire joint body as it moves, the circular arc convex curved surfaces at the four corners press the corners of the two-sided pipes to be connected from the inside so as to stretch them,

Similarly, each of the bolts is rotated counterclockwise from the outside of the double-sided pipe to bring either one of the upper and lower surfaces facing each other or either of the left and right side surfaces facing each other in the joint body relatively close to the other. If you move it in the direction to

Due to the contractive or restorative elastic deformation that spreads over the entire joint body as it moves, there is a state in which the corners of the two-sided pipe are pressed from the inside by the arc convex curved surfaces of the four corners. It is characterized by being determined to be released.

Further, in claim 2, the joint body of the joint is formed into a substantially X-shaped closed cross-sectional shape elongated in the vertical direction with short sides on both upper and lower sides and long sides on both left and right sides,

A pair of front and rear bolts are assembled in an active horizontal bridging connection state between the flat surfaces facing each other, with the middle height position of the left and right side surfaces, which are the long sides, being parallel flat surfaces, and

By turning the bolts of the joint clockwise or counterclockwise from the outside of the two-sided rectangular pipe to be connected, which corresponds to the joint body and has a rectangular cross-section that is elongated in the vertical direction,

It is characterized in that either one of the left and right side surfaces of the joint body that face each other is set to be moved in the direction of separating or approaching the remaining other side.

In claim 3, when the arc convex curved surface of the joint body of the joint presses the corners of the two-sided square pipes to be connected from the inside so as to stretch, each of the arc convex curved surfaces forms two lines parallel to the corners of the two-sided square pipes. It is characterized by maintaining a line contact state.

In claim 4, one insertion hole for a bolt turning operation tool corresponding to a pair of front and rear bolts assembled to the joint main body of the joint is circular and larger in diameter than the bolt to the connecting portion of the two-sided pipe to be connected. It is characterized by forming openings one by one.

In claim 5, a joint used in the square pipe connection device according to claim 1,

Square pipes of the same size and shape as the square pipes to be connected are used as materials, and press working, rolling, and other plastic working are performed so that both the upper and lower sides and the left and right sides are depressed inward into a substantially V-shaped groove. a joint body integrally molded into an overall substantially X-shaped closed cross-sectional shape with four corners projecting radially toward the squares of the square pipes to be connected, forming arcuate convex curved surfaces;

A pair of front and rear screw holes are distributed on either one of the upper and lower surfaces facing each other or on either of the left and right surfaces of the joint body, and the screw shaft portion is kept in a screwed state, and corresponds to the remaining other surface. A straight shaft portion having a diameter smaller than that of the screw shaft portion is inserted into the formed pair of front and rear blank holes, and the tip of the straight shaft portion is crimped via a washer or a retaining ring. and a hexagon socket head bolt.

In claim 6, a joint used in the square pipe connection device according to claim 1,

Both the upper and lower sides and the left and right sides are recessed inward in a substantially V-shaped groove, and the four corners form an arc convex curved surface that radiates toward the square part of the square pipe to be connected. a fitting body extruded into an X-shaped closed cross-sectional shape;

A pair of front and rear screw holes are distributed on either one of the upper and lower surfaces facing each other or on either of the left and right surfaces of the joint body, and the screw shaft portion is kept in a screwed state, and corresponds to the remaining other surface. A straight shaft portion having a diameter smaller than that of the screw shaft portion is inserted into the formed pair of front and rear blank holes, and the tip of the straight shaft portion is crimped via a washer or a retaining ring. and a hexagon socket head bolt.

Further, in claim 7, a parallel flat surface is formed at an intermediate position between the upper and lower surfaces of the joint body or an intermediate position between the opposite left and right side surfaces of the joint body. while forming

Similarly, a pair of front and rear clearance holes are correspondingly formed in the remaining other of the two flat surfaces facing each other, and screw shaft portions of hexagon socket head bolts respectively inserted into the clearance holes and straight shaft portions having a smaller diameter than the screw shaft portions are formed. By the boundary step surface,

It is characterized in that when the bolt is rotated clockwise, the remaining other of the two flat surfaces is pushed toward the tip of the bolt along the rotation axis.

According to the structure of claim 1, the joint body of the joint for connecting square pipes having a rectangular cross section has both upper and lower surfaces and left and right side surfaces recessed inward in a substantially V-shaped groove shape, and furthermore, the four corner portions are recessed. Since both of them are integral parts molded into an overall substantially X-shaped closed cross-sectional shape (hollow) that forms a circular convex curved surface, in a state in which this is inserted as a core into the connection part of the square pipe, a pair of front and rear When the bolts are rotated clockwise or counterclockwise from the outside of the two pipes to be connected, the upper and lower sides or the left and right sides of the joint body move relatively away from each other or approach each other. , along with the movement, the entire joint body is elastically deformed so as to expand or contract the hollow interior, thereby causing the circular arc convex curved surfaces of the four corners to move to the corresponding square portions of the square pipe from the inside. The square pipes can be pressed as if they were stretched, and the pressed state can be released. As a result, the square pipes can be connected and fixed in a state of high durability and stability, and all the problems of the known technology mentioned at the beginning can be solved. There is

In that case, especially if the configuration of claim 2 is adopted, the joint body of the connecting joint should correspond to the vertical (vertical) direction of the rectangular pipe in relation to the rectangular pipe in cross section. A pair of front and rear bolts are installed horizontally between flat surfaces formed at mid-height positions on both left and right sides, which are the long sides of the cross section. Since it is assembled in a bridging connection state, the left and right side surfaces move relatively apart or approach each other due to the turning operation of the bolt, and the expansion or contraction that spreads over the entire joint body. The elastic deformation action is performed extremely smoothly, and the above effect of claim 1 can be further improved.

Further, if the configuration of claim 3 is adopted, the circular arc convex curved surfaces at the four corners of the joint body are pressed against the corresponding quadrangular portions of the double-sided pipes to be connected in a line contact state with two parallel lines. As a result, the state of pressing from the inside becomes remarkably stable and strong, and together with the fact that the joint body is a single hollow piece as a whole, external forces such as loads and vibrations applied from the outside of the double-sided pipe. can exert excellent resistance against

Further, if the configuration of claim 4 is adopted, the insertion holes for the bolt turning operation tool corresponding to the pair of front and rear bolts in the joint body are formed one by one at the connecting portions of the two-sided pipes to be connected. Therefore, a joint of a certain length is inserted into the connection part of the double-sided pipe, half in the front half and half in the rear half, and a bolt turning operation tool is inserted through the large-diameter circular insertion hole, The bolt can be rotated without error, and the work of connecting double-sided pipes can be performed efficiently and conveniently.

On the other hand, according to the configuration of the joint for square pipes described in claims 5 and 6, the joint main body can be easily manufactured by plastic working of a steel pipe material or extrusion molding of an aluminum material. By adopting a square pipe of the same size and shape as the square pipe to be connected as in item 5 as a material for the joint body, there is no need to procure special materials for manufacturing the joint body, and the maximum possible There is a practical advantage that a mass production effect can be expected.

In the joint according to either claim 5 or claim 6, if the structure of claim 7 is adopted, the joint body is formed at an intermediate position between the upper and lower surfaces or at an intermediate position between the left and right sides of the joint body. In addition to being able to stably assemble a hexagon socket head bolt between the flat surfaces facing each other in a locked state, one of the two flat surfaces facing each other has a pair of front and rear blank holes for receiving bolts. As the bolt rotates in the clockwise direction (spiral direction), the boundary step surface between the screw shaft portion and the straight shaft portion of the bolt pushes the bolt toward the tip. Also, there is an effect that the overall elastic deformation action of the joint body can be smoothly performed.

It is a side view which shows the connection part of the square pipe which concerns on embodiment of this invention. FIG. 2 is a front view of FIG. 1; Fig. 2 is a side view showing the square pipe joint of Fig. 1; 4 is an enlarged front view of FIG. 3; FIG. FIG. 2 is a side view of a state in which a joint is inserted and set in the square pipe of FIG. 1; It is an enlarged front view of a state in which the joint is similarly inserted and set in the square pipe. 7 is a reduced cross-sectional view taken along line 7-7 of FIG. 6; FIG. FIG. 10 is an explanatory diagram showing elastic deformation action in which the joint body expands or contracts as a whole; FIG. 7 is a front view corresponding to FIG. 6 in a state of use in which the arc convex curved surface of the expanded joint body presses the corner of the square pipe from the inside. FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 9;

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. 1 and 2 show a connecting portion of a square pipe (P) according to an embodiment of the present invention, and FIGS. 3 and 4 show a joint (J) for connecting the square pipe (P).

The square pipe (P) to be the object of the present invention has a rectangular cross section, but in the illustrated embodiment, it is a steel pipe or aluminum extruded pipe having a rectangular cross section elongated in the vertical (longitudinal) direction. ): 60 mm × short side (x): 30 mm × thickness (t): a plurality of square pipes (P) having a size of 1.6 mm and having a certain unit length (for example, 5 m) that is easy to handle , under an appropriate overall length (e.g., 50m) connected (extended) in a straight series state, for example, a guide rail on which a poultry house feeder runs, a temporary scaffold on which construction workers walk, and a warehouse framework Widely used for pillars and various other uses.

(10) is a circular bolt turning hole drilled in one of the left and right side surfaces (11L) and (11R) forming the long side (y) of the square pipe (P) (the right side surface (11R) in FIG. 2). It is an insertion hole for an operation tool, and is opened at a position where a constant distance (d) of, for example, 25 mm is maintained from the cut-off end of the square pipe (P) (the butt end of the square pipes), and the joint (J ) has a larger diameter (for example, 12 mm) than the bolt described later.

On the other hand, the joint (J) has a certain length (L) (for example, 80 mm) necessary for stable and firm connection of the square pipes (P), and a core is attached to the joint between the square pipes (P). is inserted as In other words, each half of the joint (J) having a fixed length (L) is inserted into the hollow interior of the double-sided pipe (P) to be connected from its separated end. It is also possible to withdraw each from the hollow interior.

The joint (J) consists of a series of joint bodies (A) formed in a substantially X-shaped closed cross-sectional shape elongated in the vertical (longitudinal) direction corresponding to the square pipe (P), and the joint body (A). It consists of a pair of front and rear bolts (B) assembled in an operative horizontal bridging connection state to an intermediate height position.

3 and 4, the joint body (A) of the joint (J) has upper and lower surfaces (12U) and (12D) that form the short sides (X) and left and right sides that form the long sides (Y). Both sides (13L) and (13R) are recessed inward in a substantially V-shaped groove, and all four corners protrude radially toward the square (corner) of the square pipe (P) ( In other words, an overall elongated, substantially X-shaped closed cross-sectional shape in the up-down (longitudinal) direction forming arcuate convex curved surfaces (14) projecting in opposite directions along diagonal lines that can also function as braces for square pipes. (Hollow) is shaped.

That is, for the V-shaped grooves in which the upper and lower surfaces (12U) and (12D) of the joint body (A) are recessed symmetrically, the opening (crossing angle) (α) is a narrow small angle (acute angle) such as 85 degrees. ), and the left and right sides (13L) and (13R) of the joint body (A) are recessed symmetrically with each other. The angle (obtuse angle) is shallow and is formed in a relationship that changes differently.

There are no restrictions on the method of forming the joint body (A) of the joint (J) into such a closed cross-sectional shape, and it may be freely designed. Square pipes of the same size and shape as (P) (steel pipes whose sizes are shown as examples above) are used as materials, and press (drawing), rolling, and other plastic working are applied to them. Therefore, it is preferable that the joint body (A) is integrally formed into an overall substantially X-shaped closed cross-sectional shape having the same peripheral length as that of the square pipe (the steel pipe described above) of its material.

In this way, there is no need to procure special materials for the production of the joint body (A), and scraps of the square pipe (P) to be connected and other parts can be utilized, thereby maximizing mass production. This is because the effect can be obtained.

However, it is not limited to the method of plastically deforming the joint body (A) from the steel pipe of the same size and shape as the square pipe (P) to be connected into a substantially X-shaped closed cross-sectional shape. etc. may be used as the material for the joint body (A), and these metal materials may be extruded into an overall substantially X-shaped closed cross-sectional shape.

Regarding the left and right side surfaces (13L) and (13R) forming the long side (Y) of the joint body (A), it has been explained that both of them are recessed inward in a substantially V-shaped groove. The intermediate height positions of (13L) and (13R) are formed as flat surfaces (15L) and (15R) as shown in FIG. A pair of front and rear screw holes (16) are provided on the flat surface (15R) formed on the right side surface (13R) of FIG. A pair of front and rear clearance holes (17) corresponding to the screw holes (16) are distributed on the surface (15L).

In that case, the flat surface (15R) of one of the left and right side surfaces (13L) and (13R) (the right side surface (13R)) is burred to increase the depth of the screw hole (16). , a nut (not shown) instead of burring and tapping is welded to the flat surface (15R) of the one (right side surface (13R)) from the outside, and the weld nut sufficiently closes the screw hole (16). depth.

As the pair of front and rear bolts (B) in the joint (J), for example, a threaded shaft portion (18) having an outer diameter of 8 mm and a straight (non-threaded) shaft portion (19) having a smaller diameter (6 mm) are used. Therefore, it is desirable to adopt bolts with the same M8 hexagonal socket (20) that do not have heads larger in diameter than the screw shaft (18).

Then, the threaded shaft portion (18) of the bolt (B) with the hexagonal hole (20) is attached to one of the left and right side surfaces (13L) and (13R) of the joint body (A) (the right side surface (13R)). screw into the screw hole (16) opening in the flat surface (15R) of the straight shaft (19) while screwing from the screw hole (16) toward the tip (leftward in FIG. 4). Similarly, the left and right side surfaces (13L) and (13R) of the joint body (A) are inserted into the blank holes (17) opening in the flat surface (15L) of the remaining other side (the left side surface (13L)), and the other ( By crimping the tip protruding outward from the flat surface (15L) of the left side surface (13L), the left and right side surfaces (13L) and (13R) of the joint body (A) are placed horizontally horizontally between the facing each other. assembled in the

(21) is the crimped portion at the tip, (22) is a washer or retaining ring inserted into the straight shaft portion (19) from the outside, and (23) is the screw shaft portion (18) and a diameter smaller than this. The boundary step surface (vertical surface) with the straight shaft portion (19), and the left and right side surfaces (13L) of the joint body (A) are formed by the boundary step surface (23) and the washer (22) or retaining ring. The flat surface (15L) on the other side (the left side surface (13L)) of (13R) where the blank hole (17) opens is sandwiched from the inside and outside.

The intermediate height position of the joint body (A) formed in such a vertically elongated, substantially X-shaped closed cross-sectional shape, and the left and right side surfaces (13L) (13R) forming the long side (Y) of the joint body (A). As a completed joint (J) in which the bolt (B) with the hexagonal socket (20) is horizontally assembled between the opposed flat surfaces (15L) (15R) formed in the Due to the relationship with the square pipe (P) (steel pipe or aluminum extruded pipe whose dimensions are exemplified above) having a rectangular cross section elongated in the (longitudinal) direction, for example, the long side of the joint body (A) ( Y) is 53.6 mm, and the short side (X) is sized to 23.6 mm, so that it can be inserted and set into the hollow interior of the square pipe (P) without difficulty in that state. .

In that case, the fixed length (Z) from the recessed base end of the hexagonal hole (20) to the crimped portion (21) at the tip of the bolt (B) is the short side ( X) shorter than (23.6 mm above), for example 21 mm. The thickness (T) of the joint body (A) is 1.6 mm, which is the same as the thickness (t) of the square pipe (P).

In short, around the joint body (A), which is shaped in the overall substantially X-shaped closed cross-sectional shape of the joint (J), there is provided a suitable constant for pre-playing with the square pipe (P) to be connected. The gap (S) is preferably secured by a numerical value (dimension) corresponding to the thickness (T) (1.6 mm as exemplified above) of the joint body (A).

Since the joint (J) for square pipes of the illustrated embodiment has the above-described configuration, when connecting square pipes (P) by using the joint (J), first, the fixed length (L) of the joint (J) is adjusted. 5 to 7, insert and set the front half of the pipe into either one of the double-sided pipes (P) to be connected. At that time, positioning adjustment is made so that the bolt (B) with the hexagonal hole (20) of the joint (J) and the insertion hole (10) for the bolt turning operation tool of the square pipe (P) correspond to each other.

Then, a bolt turning operation tool (24) (hex wrench) is inserted through the insertion hole (20) from the outside (lateral direction to the left or right as shown) of the square pipe (P), and The hexagonal hole (20) of the bolt (B) in the joint (J) is engaged with the hexagonal hole (20), and the bolt (B) with the hexagonal hole (20) is rotated clockwise (spiral direction).

Then, one of the left and right side surfaces (13L) and (13R) of the joint body (A) of the joint (J) (the left side surface (13L) in FIGS. 6 and 8) is a flat surface at the intermediate height position. (15L) is moved toward the tip of the bolt (B) (to the left in FIGS. 6 and 8) by the boundary step surface (23) between the screw shaft portion (18) and the straight shaft portion (19) of the bolt (B). At the same time as the joint body (A ), the right side face (13R) screwed to the other bolt (B) through the screw hole (16) moves away from the left side face (13L) in a screw-retracting direction (Fig. 6, 8) until it contacts (is pressed against) the corresponding right side surface (11R) of the square pipe (P). The entire body, including upper and lower surfaces (12U) and (12D) forming a shape, is elastically deformed so as to expand the hollow interior, as indicated by the dotted and solid lines in FIG. As shown in FIGS. 8 to 10, the arc convex curved surface (14) in the square pipe (P) presses the corresponding square part of the square pipe (P) from the inside so that the front half of the joint (J) and the One of the square pipes (P) is strongly fixed and integrated, and there is no risk of separation from each other.

Therefore, next, the other square pipe (P) to be connected is inserted into the rear half of the joint (J) that is still exposed from the square pipe (P), as indicated by the chain line in FIG. , and the square pipe (P) on one side, the insertion hole (10) for the bolt turning operation tool of the square pipe (P) and the bolt (B) with the hexagon socket (20) of the joint (J) are aligned. , naturally correspond to each other exactly.

Therefore, a bolt turning operation tool (24) (same hexagonal bar wrench) is also inserted through the insertion hole (10) from the outside of the square pipe (P) (in the same right lateral direction as shown), The bolt (B) of the joint (J) is engaged with the hexagonal hole (20), and the bolt (B) is rotated clockwise (in the spiral direction).

By rotating the bolt (B) with the hexagon socket (20), the left and right side surfaces (13L) and (13R) of the joint body (A) of the joint (J) move in the direction of being relatively separated, and the movement Based on this, the entire joint body (A), including the upper and lower surfaces (12U) and (12D), is interlocked as shown in FIG. (14) presses the corresponding square portions of the square pipe (P) from the inside as shown in FIGS. The fixing relationship with (P) is the same as the operation described with reference to FIGS. 6 to 8, and the rear half of the joint (J) is also fixed and integrated with the other square pipe (P) so as not to be detachable.

By operating the bolt rotating operation tool (24) two times, the square pipes (P) are connected to each other to form a joint (J) of a certain length (L) inserted as a core. It is connected and fixed in an orderly manner in a straight series state through the intermediary, and by repeating this, it is possible to form the traveling guide rails and temporary scaffolds exemplified above. The bolt turning operation tool insertion hole (10) formed in the square pipe (P) may be closed with a decorative cap (not shown) as required.

In that case, each of the arcuate convex curved surfaces (14) projecting radially from the joint body (A) has an arcuate shape with a larger radius than the inner corner of each corresponding corner of the square pipe (P). Therefore, when the corners of the double-sided pipe (P) are pressed from the inside so as to be stretched, the arc convex curved surfaces (14) of the double-sided pipe (P) are formed as shown in FIGS. A line contact state is maintained by two lines (a) and (b) parallel to the inner corner of the corner.

Therefore, the joint body (A) of the joint (J) is used as a core of a square pipe (P) having a rectangular cross section elongated in the vertical (longitudinal) direction. The square pipe (P) is uniformly stretched and pressed from the inside as a whole that is elastically deformed in a series, and the square pipe (P) It is possible to obtain a connected and fixed state with high durability strength and stability, and even if the square pipe (P) is subjected to repeated vibrations and loads from the outside, the joint body (A) will deform improperly or rattle. There is no risk of causing a crack or creating a step at the joint between the square pipes (P).

Further, the bolt (B) is turned counterclockwise by the turning operation tool (24) (hexagon wrench) to rotate both left and right side surfaces (13L) of the joint body (A) of the joint (J). (13R) can also be moved in a relatively approaching direction, and based on that movement, the entire joint body (A) including the upper and lower surfaces (12U) and (12D) will interlock as shown in FIG. As a result, the hollow interior is elastically deformed so as to shrink or restore slightly from the state shown in FIG. 9 to the state shown in FIG. The corresponding square portions of the double-sided square pipes (P) can be released from the state of being pushed from the inside, so that the connection state between the square pipes (P) can be disassembled, and the joint ( J) can also be pulled out and replaced.

In the illustrated embodiment, a square pipe (P) having a rectangular cross section elongated in the vertical (longitudinal) direction and a closed sectional shape (hollow) elongated in the vertical (longitudinal) direction corresponding to the rectangular pipe (P) are formed. Although the specific configuration and operation (connection method) of the integrated joint body (A) have been described, the square pipe (P) to be connected may have a square cross section, and the connection Although not shown as the joint body (A) of the joint (J), the two orthogonal sides of the upper and lower sides (12U) and (12D) and the left and right sides (13L) and (13R) have no length difference and are almost the same. An X-shaped closed cross-section (hollow) shaped integral piece can be employed and is within the scope of the present invention. The configuration and action (connecting method) of the joint (J) for connecting the square pipes (P) having a square cross section are substantially the same as those of the illustrated embodiment described above, and thus the description thereof will be omitted.

(10)...Insertion hole for bolt turning operation tool (11L) (13L)...Left side (11R) (13R)...Right side (12U)...Upper surface (12D)...Lower surface (14)...Circular convex curved surface (15L)...(Left) Flat surface (15R)...(Right) Flat surface (16)...Screw hole (17)...Bug hole (18) Screw shaft portion (19) Straight shaft portion (20) Hexagonal hole (21) Crimp portion (22) Washer (23) Boundary step surface (24 )・・・Bolt rotation operation tool (P)・・・Square pipe (J)・・・Joint (A)・・・Joint body (B)・・・Bolt (L)・・・Coupling length (Z) Bolt length (X) (x) Short side (Y) (y) Long side (S) Gap (a) (b) ... 2 lines (T) (t) ... thickness

Rotate the bolts clockwise from the outside of the square pipes to be connected to rotate either one of the upper and lower surfaces facing each other or either of the left and right side surfaces facing each other in the joint body relative to the remaining other. If you move them away from each other,

Claims (7)

A device for connecting square pipes with a rectangular cross section in a straight series state by a joint of a fixed length that is inserted as a core into the connection part,
The above joint is
a joint body shaped to have an overall substantially X-shaped closed cross-sectional shape in which both the upper and lower surfaces and the left and right surfaces are recessed in a substantially V-shaped groove, and all four corners form arcuate convex curved surfaces;
A pair of front and rear parallel bolts assembled in an active bridging connection state between the upper and lower surfaces facing each other or between the left and right side surfaces facing each other in the joint body,
Rotate the bolts clockwise from the outside of the square pipes to be connected to rotate either one of the upper and lower surfaces facing each other or either of the left and right side surfaces facing each other in the joint body relative to the remaining other. If you move it in the direction of approaching,
Due to the expansive elastic deformation that spreads over the entire joint body as it moves, the circular arc convex curved surfaces at the four corners press the corners of the two-sided pipes to be connected from the inside so as to stretch them,
Similarly, each of the bolts is rotated counterclockwise from the outside of the double-sided pipe to bring either one of the upper and lower surfaces facing each other or either of the left and right side surfaces facing each other in the joint body relatively close to the other. If you move it in the direction
Due to the contractive or restorative elastic deformation that spreads over the entire joint body as it moves, there is a state in which the corners of the two-sided pipe are pressed from the inside by the arc convex curved surfaces of the four corners. A connection device for square pipes, characterized in that it is determined to be released. The joint body of the joint is formed into a vertically elongated substantially X-shaped closed cross-sectional shape with short sides on both upper and lower sides and long sides on both left and right sides,
A pair of front and rear bolts are assembled in an active horizontal bridging connection state between the flat surfaces facing each other, with the middle height position of the left and right side surfaces, which are the long sides, being parallel flat surfaces, and
By turning the bolts of the joint clockwise or counterclockwise from the outside of the two-sided rectangular pipe to be connected, which corresponds to the joint body and has a rectangular cross-section that is elongated in the vertical direction,
2. The connecting device for square pipes according to claim 1, wherein one of the left and right side faces of the joint body is moved in a direction of separating from or approaching the other side of the joint body. . When the arc convex curved surface of the joint body of the joint presses the corners of the two-sided square pipes to be connected from the inside so as to stretch each, the arc convex curved surfaces form a line contact state with two lines parallel to the corners of the two-sided square pipes. 3. The connection device for square pipes according to claim 1 or 2, wherein Insertion holes for bolt rotation operation tools corresponding to a pair of front and rear bolts assembled to the joint main body of the joint are formed into circular openings each having a larger diameter than the bolts to the connecting portions of the two-sided square pipes to be connected. 3. The connection device for square pipes according to claim 1 or 2, characterized in that: A joint used in the square pipe connection device according to claim 1,
Square pipes of the same size and shape as the square pipes to be connected are used as materials, and press working, rolling, and other plastic working are performed so that both the upper and lower sides and the left and right sides are depressed inward into a substantially V-shaped groove. a joint body integrally molded into an overall substantially X-shaped closed cross-sectional shape with four corners projecting radially toward the squares of the square pipes to be connected, forming arcuate convex curved surfaces;
A pair of front and rear screw holes are distributed on either one of the upper and lower surfaces facing each other or on either of the left and right surfaces of the joint body, and the screw shaft portion is kept in a screwed state, and corresponds to the remaining other surface. A straight shaft portion having a diameter smaller than that of the screw shaft portion is inserted into the formed pair of front and rear blank holes, and the tip of the straight shaft portion is crimped via a washer or a retaining ring. A joint for a square pipe, comprising: a hexagon socket head bolt. A joint used in the square pipe connection device according to claim 1,
Both the upper and lower sides and the left and right sides are recessed inward in a substantially V-shaped groove, and the four corners form an arc convex curved surface that radiates toward the square part of the square pipe to be connected. a fitting body extruded into an X-shaped closed cross-sectional shape;
A pair of front and rear screw holes are distributed on either one of the upper and lower surfaces facing each other or on either of the left and right surfaces of the joint body, and the screw shaft portion is kept in a screwed state, and corresponds to the remaining other surface. A straight shaft portion having a diameter smaller than that of the screw shaft portion is inserted into the formed pair of front and rear blank holes, and the tip of the straight shaft portion is crimped via a washer or a retaining ring. A joint for a square pipe, comprising: a hexagon socket head bolt. A pair of front and rear screw holes are formed on either one of the two flat surfaces, one of which is burred and a parallel flat surface is formed at the intermediate position between the upper and lower surfaces facing each other or the intermediate position between the opposite left and right surfaces of the joint body, and a pair of screw holes are formed.
Similarly, a pair of front and rear clearance holes are correspondingly formed in the remaining other of the two flat surfaces facing each other, and screw shaft portions of hexagon socket head bolts respectively inserted into the clearance holes and straight shaft portions having a smaller diameter than the screw shaft portions are formed. By the boundary step surface,
7. The method according to claim 5, wherein when the bolt is rotated clockwise, the remaining other of the two flat surfaces is pushed toward the tip of the bolt along the rotation axis. Fittings for square pipes.

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