JP5622489B2 - Thin metal joint - Google Patents

Description

  The present invention relates to a metal joint that connects two pipes in a state of intersecting at a right angle.

  A conventional product of this type of metal joint is three-dimensionally formed using a cold-rolled steel plate (for example, SPCC). As shown in Patent Document 1, two halves divided along the axis of the socket portion are used. The two pipes are sandwiched between the two members, the bolts are inserted into the connecting holes formed in the two members, screwed into the nuts, and tightened to be connected. It has become.

Design Registration No. 646222

  Recently, in order to reduce material costs and transportation costs for this type of metal joint, it has been required to reduce the thickness and weight. Attempts were made to reduce the thickness from 2.6 mm, but the reduction in wall thickness was limited to 20-30%, and the consumption of the press die, which is one of the production equipment, was severely deteriorated. Due to high costs, mass production was not achieved.

  In addition, since this type of metal joint can be used in the same shape as a half-shaped member, there is an advantage that there is no directionality of the parts, but there is a problem such as dropping the nut during assembly work, which has been strongly demanded in recent years. It is not possible to cope with the reduction of assembly man-hours. On the other hand, it was first attempted to integrate the nut by welding or caulking the nut to one of the half-shaped members, but it takes considerable effort to integrate. For this reason, recently, it has been proposed to cut the taps by making the communication holes sharp in order to make one half-divided member directly serve as a nut to achieve nutlessness. Thus, when the thickness and weight are reduced, the strength is inevitably lowered, and the screw is easily damaged.

  In order to solve the above-mentioned problems, the present invention is a metal joint that connects two pipes in a state of intersecting at right angles. Even if the wall thickness is reduced by 50% or more than the conventional product, the product strength is reduced and the cost is increased. The purpose is to provide something that is never invited.

  As a result of thought and error, the present inventor can achieve reduction in thickness and weight without degrading product strength or incurring high costs by concentrating on the selection and processing of materials and the shape of halved members. As a result, the present invention was completed.

According to the first aspect of the present invention, two pipes are held in a half-shaped member divided into two along the axis of the socket portion, and the two pipes are connected at a right angle by tightening bolts and nuts. In a thin metal joint, each half member is hardened by quenching after three-dimensional forming, and a groove that can be fitted in parallel to the axial direction on each split edge of the two socket parts of each half member irregularities engage portion is formed with, said split edge of the connecting portion located between the two socket part is formed per unit formed by being folded into a flat surface, the half-shaped member facing tightening The thin metal joint is characterized in that the respective contact portions are almost flush with each other, the contact edges of the respective contact portions hit each other, and the uneven engagement portion is engaged.

  The invention of claim 2 is the thin metal joint according to claim 1, wherein both side edges of the groove of the concave-convex engagement portion extend in a direction substantially parallel to the axis of the socket portion. .

  According to a third aspect of the present invention, in the thin metal joint according to the first or second aspect, the bolt insertion hole of any one of the half-shaped members forms a cylindrical body by burring, and the cylindrical shape A thin metal joint characterized in that a thread portion is formed on the inner surface of the body.

  The invention of claim 4 is the thin metal joint according to any one of claims 1 to 3, wherein the half-shaped member is made of boron steel.

  According to the thin metal joint of the present invention, reduction in thickness and weight can be achieved without reducing product strength or shortening the life of production equipment. The nut-side thin-walled member can be made nutless.

It is a perspective view of the connection state of two pipes by the thin metal joint which concerns on embodiment of this invention. It is a perspective view of the connection state of two pipes by the thin metal joint seen from the direction different from FIG. It is a perspective view of the nut side thin-walled half member of FIG. It is a side view of the nut side thin-walled half-shaped member of FIG. FIG. 4 is a partial cross-sectional view of the nut-side thin half member in FIG. 3.

A thin metal joint 1 according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the thin metal joint 1 includes a nut-side thin half-shaped member 3 and a bolt-side thin half-shaped member 5 as a set, and includes two pipes. Are connected in a state of crossing at right angles.
Since the nut-side thin half-shaped member 3 and the bolt-side thin half-shaped member 5 have substantially the same shape, first, a common shape based on the nut-side thin half-shaped member 3 and its manufacturing method will be described. 3 to FIG. 5, and next, the difference between the bolt-side thin half member 5 will be described.

  The nut-side thin-walled half-shaped member 3 is three-dimensionally formed by press molding using a metal mold using a single metal plate, and includes a first socket portion 7, a second socket portion 9, and their The first socket 7 and the second socket 9 are each curved in an arc shape on the same plate surface side to form a holding surface, and the holding surface has a curved surface. Along the curved surfaces of the pipes P1 and P2 to be inserted. Further, the first socket portion 7 and the second socket portion 9 intersect at a right angle.

An uneven engagement portion 11 is formed on the divided edge of the first socket portion 7. The dividing edge is provided with a step at an intermediate portion in the axial direction, and one end side is lowered by one step. The step side surface is cut out in a rectangular groove shape so that the side edge extends in a direction substantially parallel to the axis of the first socket portion 7 toward the other end side, and the outer side is the engagement convex portion 13, The side is an engagement recess 15. The depth of the groove is such that it can be assembled and disassembled.
At the dividing edge of the second socket portion 9, the other end side is lowered one step symmetrically with respect to the first socket portion 7, and a groove is formed on one end side, and an uneven engagement portion 11 having the same shape is formed. As described above, the concave and convex engaging portions 11 and 11 are formed in the first socket portion 7 and the second socket portion 9 in a point-symmetrical arrangement, respectively.

The connecting portion 17 has a central main body portion 19 which remains substantially flat, but both side portions 21 are bent in the same manner on the side of the holding surface, and when viewed from the outer side shown in FIG. Is doing.
In the upper side portion 21 of the both side portions 21, 21, the almost half side near the second socket portion 9 among the dividing edges is folded in the shape of a plane and formed on the surface side to form a contact portion 23. The front end of the contact portion 23 is a contact edge 25. The lower side portion 21 is also formed with a contact portion 23 on the almost half side near the first socket portion 7 in the divided edge. Thus, the contact portions 23 and 23 are formed in the point-symmetrical arrangement on the both side portions 21 and 21 of the connecting portion 17, respectively, and the contact portions 23 and 23 are arranged substantially parallel to each other.

  In addition, a short cylindrical body 27 protrudes from the center portion of the main body 19 on the holding surface side. This cylindrical body 27 is formed by burring. A threaded portion 29 is formed on the inner surface of the cylindrical body 27. The screw portion 29 has three or more threads.

The nut-side thin half-shaped member 3 uses a single metal plate as a raw material, and is stamped by a press to form an outer contour line. The first socket part 7, the second socket part 9, and the connecting part 17 The contact portion 23 is formed and burring is performed, and then the screw portion 29 is formed on the inner surface of the cylindrical body. And after that, it hardens and hardens to make the final product.
The bolt side thin half member 5 is formed in the same manner using the same material as the nut side thin half member 3 except that a connecting hole is formed instead of burring.

The assumed thickness of the half-shaped members 3 and 5 is 1.3 mm or less. Since the thickness of the half-shaped member manufactured using the conventional cold-rolled steel plate as a raw material is about 2.6 mm, it is halved.
The material uses a quenching effect in order to have sufficient extensibility at the processing stage such as bending, drilling, drawing, etc., and high surface hardness and strength at the final product stage. By quenching and, if necessary, subsequent tempering, the surface hardness Hv is 480 to 540, which is about 6 to 7 times higher than the hardness before quenching, and the strength is 1,600 to 1,850 MPa. It is preferable to use a material whose strength before treatment is increased from about 270 MPa to about 6.5 times. As a candidate, boron steel containing boron in low carbon steel equivalent to S20C is promising.

Next, assembly work will be described.
The pipe P1 is held in the first socket portion 7 of any one of the half-shaped members 3 and 5 and the pipe P2 is held in the second socket portion 9. Next, the pipe P1 is held in the second socket part 9 of the other half-shaped member, and the pipe P2 is held in the first socket part 7, while the concave-convex engagement of the first socket part 7 of the nut-side thin half-shaped member 3 is held. The concave and convex portions 11 and the concave and convex engaging portions 11 of the second socket portion 9 of the bolt-side thin half-like member 5 are fitted into the concave and convex portions 15 by fitting the engaging convex portions 13 in parallel with the axial direction, and the nut side thin wall The concave / convex engaging portion 11 of the second socket portion 9 of the half-shaped member 3 and the concave / convex engaging portion 11 of the first socket portion 7 of the bolt-side thin half-shaped member 5 are used as the engaging recess 15 and the engaging convex portion 13 in the axial direction. Concave / concave fitting is achieved by inserting them in parallel. The enlarged view of FIG. 1 is for explaining the fitting relationship, and the second half of the bolt-side thin half member 5 is formed on the concave and convex engagement portion 11 of the first socket part 7 of the nut side thin half member 3. A state in which the bolt-side uneven engagement portion 11 is raised by one step with respect to the nut-side uneven engagement portion 11 immediately before the uneven engagement portion 11 of the socket portion 9 is engaged, and as shown in FIG. The shape of the edge of 15 is the same as the shape of the edge of the engagement convex part 13.

Next, a bolt is inserted from the communicating hole side of the bolt-side thin half-shaped member 5 and screwed into the threaded portion 29 of the nut-side thin half-shaped member 3 and tightened. The contact portion 23 of the nut-side thin half-shaped member 3 and the contact portion 23 of the bolt-side thin half-shaped member 5 are opposed to each other and are substantially flush with each other. As the tightening progresses, the respective contact edges 25 approach each other, and finally, further tightening is prevented, so that the tightening can be performed appropriately. Moreover, since the screw part 29 is not damaged, disassembly and reassembly are possible.
If there is no contact portion 23, the divided edges of the side portions 21 of the connecting portions 17 of the halved members 3 and 5 facing each other will come into contact with each other, but the divided edges will contact each other in an obliquely intersecting state. Therefore, the tightening proceeds without stopping and the concave and convex engagement portions 11 and 11 of the half-shaped member are opened up and down.

Upon completion of the assembly operation, the pipe P1 and the pipe P2 are connected as shown in FIGS. In FIGS. 1 and 2, the bolt is not shown for the convenience of visual recognition.
According to this thin metal joint 1, the material is hardened and strengthened, and the concave / convex engagement portion 11 is difficult to come off, so that even if force is applied in the twisting direction, the pipe is difficult to twist. .
Moreover, since the engagement convex part 13 of the uneven | corrugated engagement part 11 can be engage | inserted in parallel with an axial direction with respect to the engagement recessed part 15, an assembly and a disassembly are easy.

  As described above, the nut-side thin half-shaped member 3 and the bolt-side thin half-shaped member 5 are sufficiently hardened and strengthened, and the contact portion 23 and the uneven engagement portion 11 are formed. As a result, it can be tightened and assembled properly, and is difficult to twist during use. In addition, since the screw part 29 is not damaged and can be easily disassembled, it can be reused.

Using nut steel (plate thickness: 1.2 mm) as a raw material, the nut-side thin-walled half-shaped member 3 having the above-described shape was manufactured. The height dimension of the inner peripheral surface of the cylindrical body 27 of the nut-side thin half member 3 was 3 mm or more, and the screw thread was 3 or more. At the time of manufacture, the production equipment conventionally used was used, and the mold was modified to be thin.
It was heated in a non-oxidizing furnace under the conditions of a heating temperature of 870 to 900 ° C. and a holding time of 30 minutes, put into oil and quenched, and then tempered.

Then, when the nut side thin-walled half member 3 was tested, the surface hardness Hv: 480 to 540 and about 6 to 7 times higher than the hardness before the quenching treatment, and the strength was 1,600 to 1,850 MPa by the quenching treatment. It was confirmed that the strength was about 6 to 7 times higher than the strength before quenching.
In addition, a pair of bolt-side thin half-members 5 manufactured in the same way from the same material are engaged and held with two pipes, and tightened with M6 cap screw bolts, a tightening torque of 100 kgf · cm Then, the contact portions 23 and 23 hit and the further tightening was prevented. Further, the screw portion 29 was not damaged.

  After connecting the pipes P1 and P2, when subjected to a torque test for twisting the pipe, the uneven engagement portion 11 is difficult to come off, and is pulled up to 16 kgf · m, which is three times higher than a thick product using a conventional cold rolled steel plate. It was confirmed that it was possible.

In Japan, when resources are high, reducing the thickness and weight of half-divided members is very important for resource-saving in Japan, but not only that, but the effect of reducing the weight is the same as when manufacturing (hoop materials, pressing, quenching, surface treatment). , Finishing, product delivery), transportation equipment can be reduced in weight, and fuel consumption can be improved.
Conventionally, a pair of half-shaped members were manufactured mainly using cold-rolled steel plate (SPCC), and bolts and nuts were tightened together with nuts, but compared to the conventional half-shaped members, If the method of the present invention is used to manufacture a pair of halved members including the bolt side to reduce the thickness and weight, an amazing weight reduction of 60% can be achieved. Since the production volume of 980 tons in 2002 is 448 tons and lighter by 532 tons, it is clear how great the weight reduction effect is.

In recent years, CO ₂ reduction has been demanded due to environmental problems. However, if all of the halved members are reduced in thickness and weight based on the sales volume in 2002, CO _{2 of} 1,329 tons per year is required. ₂ Reduction effect can be expected.
Furthermore, in the method of the present invention, special steel is used as a material, and a quenching process is additionally performed. However, the material is thin, for example, a plate thickness of 2.6 mm in the past is 1.3 mm or less. That is, since it can be replaced with a sheet having a thickness less than half, as a result, it can be sold at almost the same price as the conventional product, and the problem of cost can be solved.

Also, if it is nutless, assembly work at the site can be considerably shortened.
By exchanging the parts of the hole of the mold, it is possible to produce both the nut side thin half member and the bolt side thin half member.

DESCRIPTION OF SYMBOLS 1 ... Thin metal joint 3 ... Nut side thin half member 5 ... Bolt side thin half member 7 ... 1st socket part 9 ... 2nd socket part 11 ... Concavity and convexity joint part 13 Convex part 17 ... Connection concave part 17 ... Connection part 19 ... Body part 21 ... Side part 23 ... Contact part 25 ... Contact edge 27 ... Cylindrical body 29 ... Screw parts P1, P2 ... Pipe

Claims (4)

In a thin metal joint in which two pipes are held in a half-shaped member divided into two along the axis of the socket part and the two pipes are connected at right angles by tightening bolts and nuts,
Each half-shaped member is hardened by quenching after three-dimensional molding,
An uneven engagement portion having a groove that can be fitted in parallel to the axial direction is formed on each split edge of the two socket portions of each half-shaped member,
Wherein the dividing edge of the connecting portion located between the two socket parts per formed by being folded into a flat surface is formed,
A thin-walled metal joint characterized in that, when tightened, the contact portions of the opposing half-shaped members are almost flush with each other, the contact edges of each contact portion hit each other, and the uneven engagement portion engages. In the thin metal joint according to claim 1,
A thin metal joint characterized in that both side edges of the groove of the concave / convex engagement portion extend in a direction substantially parallel to the axis of the socket portion. In the thin metal joint according to claim 1 or 2,
A thin metal joint characterized in that a hole for inserting a bolt of any one of the half-shaped members forms a cylindrical body by burring, and a screw portion is formed on the inner surface of the cylindrical body. In the thin metal joint according to any one of claims 1 to 3,
A thin metal joint characterized in that the half-shaped member is made of boron steel.

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