JPH072783Y2 - Fume tube - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fume pipe for an underground burial propulsion method.

[Prior Art] The structure of a conventional fume tube will be described with reference to FIG.
In FIG. 7, reference numeral 1 denotes a cylindrical tubular body, and the tubular body 1 is made of concrete or the like with high pressure resistance. An annular frame body 2 made of an iron plate is provided on the edge of the opening of the tube body 1. The annular frame 2 was formed by bending a strip-shaped iron plate into an annular shape, and butt-welding both ends 3 and 4 of the groove as shown in FIG. 5 shows a butt welding part.

Then, as shown in FIG. 8, a large number of fume pipes are propelled in the soil in series while fitting the base ends of the other fume pipes to the inner circumference of the protruding portion of the annular frame body 2 of one fume pipe. While being connected, it is buried underground.

[Problems to be Solved by the Invention] By the way, when the internal pressure increases due to the fluid flowing through the pipe body 1, the increase in pressure expands the annular frame body 2.
If this expansion exceeds the limit, there is a problem that the butt welded portion 5 is separated and fractured. Further, when the fume pipe is connected, if gravel as shown in FIG. 8 is mixed, the joint strength of the welded portion is weak and the frame 2 is easily separated.

An object of the present invention is to provide a fume tube in which the annular frame does not easily break due to an increase in internal pressure and the like, and which has improved durability as a whole.

[Means for Solving the Problems] In order to achieve the above object, the fume tube according to the present invention comprises:
A fume tube having a tubular body and an annular frame body provided at an opening edge of the tubular body, the annular frame body being formed by bending a long steel plate into an annular shape and welding both ends thereof to each other in a fume pipe; The both ends of the steel plate are formed in a concavo-convex shape that meshes with each other, and a plurality of pins are projectingly provided on the inner peripheral surface of the annular frame that interferes with the tubular body.

Here, it is preferable that the convex portion is widened toward the tip and the concave portion is correspondingly widened toward the back. The joint strength is increased by engaging them.

[Operation] When the concavo-convex portions on both ends of the steel plate are meshed with each other and then welded, the welding length and contact area at both ends can be significantly increased as compared with a case where simple flat surfaces are butted.
As a result, even if an expanding force due to internal pressure is applied in the welded state, the rupture resistance increases due to the increase in the contact area, and the pressure resistance as a whole increases. Further, according to the present invention, since a plurality of pins are provided on the inner peripheral surface of the annular frame, which interferes with the tubular body, a plurality of pins are provided when the annular frame is attached to the tubular body. Is in a state of biting into the tubular body, and the annular frame body is more firmly attached to the tubular body as compared with a case where the inner peripheral surface of the annular frame body is smooth.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. Both ends 3 of a long steel plate forming the annular frame 2,
Reference numeral 4 is an uneven shape and is formed so as to mesh with each other. In this embodiment, the projections at both ends widen toward the tip, and accordingly, the recesses between the adjacent projections widen toward the back side. As a result, when both ends 3 and 4 are engaged with each other, the projections at both ends engage with each other in the circumferential direction of the annular frame body, and separate even if a tensile force in the circumferential direction of the frame body 2 is applied. Will disappear. In addition to this meshed state, as shown in FIG. 3, the edges of both end portions 3 and 4 are groove-processed and welded to each other as indicated by reference numeral 5 to be integrated. From the viewpoint of manufacturing and strength, it is preferable that the inclination angle α of both side edges of the convex portion (concave portion) with respect to the longitudinal direction of the steel plate is about 45 degrees. Further, since welding is performed along the meshing contact portions of the both end portions 3 and 4, the area of the welded portion 5 is increased as compared with the conventional butt welding, and thus the shear strength is also increased.

Even if an expanding force is applied to the annular frame body 2 due to an increase in pressure in the tube body 1 or the like, the frame body does not easily break because the frame body has increased tensile strength and shear strength. Generally, in the conventional structure with only welding, the average strength against breakage is JIS3106 SM5.
For 0C, has been calculated to 390~470N · kg / mm ^2, the average strength was experimentally confirmed was 385N · kg / mm ^2. On the other hand, the average strength of the annular frame body according to the above-mentioned embodiment is improved to 460 Nkg / mm ² , which is comparable to the strength of iron itself which is the structural material, and the strength reliability as a product. Has been significantly increased.

The manufacturing method of the annular frame is as follows. Long steel plate with both ends sheared into uneven shapes (see Fig. 10) is bent into an annular shape by a three-roll machine, and then both ends are engaged. And welded by CO ₂ arc welding (GMAW).

FIGS. 4 to 6 are front views of main parts showing other embodiments in which the uneven shapes are different from each other. Needless to say, the concavo-convex shape of the present invention is not limited to these. Sixth
As shown in the figure, different shapes of unevenness may be mixed, and as shown in FIG. 9 to be described later, a simple mountain-shaped or rectangular uneven shape may be used.

FIG. 9 shows an embodiment in which a large number of stud pins 6 are provided on the inner surface of the annular frame body 2 shown in FIG. 2 to prevent the frame body 2 from coming off the tube body. Conventionally, long round steel is welded and fixed to the inner circumference of the frame body 2 along the circumferential direction, whereby
Although the annular frame 2 was prevented from being unintentionally detached from the tube 1, the round steel was easily separated from the frame due to the pressure of earth and sand during the propulsion work, and it could not be said to be sufficient. In this embodiment, since a plurality of stud pins 6 are welded by pressure welding instead of long round steel, the adhesive strength between each stud pin 6 and the frame body 2 is increased, and each stud pin 6 is attached to the tube body 1. Since it is in the bite state, even if the annular frame 2 receives a large amount of earth and sand resistance at the time of burying, it is possible to reduce the risk of accidentally detaching from the tube 1. Further, a stud welder can be used for welding the stud pin 6, and its welding operation is extremely easy as compared with the case of welding a long round steel bar.

FIG. 10 shows a plan view of the annular frame body 2 of FIG. 9 in a developed state, and the stud pins 6 are provided only at the portions where they interfere with the pipe body. The frame body 2 of this embodiment has a total length L of 3072, for example.
mm, width W 240 to 250 mm, stud pin spacing l is 95 m
m, thickness is 4.5 mm, distance between stud pins in the width direction is 70 m
m is preferred.

11 to 13 show examples of the stud pin 6, respectively. FIG. 11 shows that the part that bites into the concrete pipe body 1 is cylindrical, FIG. 12 shows that the part is stepped, and FIG. 13 shows , The one in which a funraji is formed on the top of the portion is shown. Considering the reliable fixation of the stud pin by biting into the pipe body 1, the one shown in FIG. 12 or FIG. 13 is preferable. The part indicated by reference numeral 12 is a welded portion to the frame body 2.

[Effects] According to the present invention, since both ends of the uneven shape are meshed and welded, even if an expanding force is applied to the annular frame, they are not easily separated or broken. As a result, the pressure resistance of the entire product can be improved and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a fume tube according to the present invention, FIG. 2 is an enlarged plan view of a connecting portion of an annular frame body of the same embodiment, and FIG. 3 is a III-III line in FIG. And FIG. 4 to FIG. 6 are cross-sectional views taken along the line of FIG.
FIG. 7 is a perspective view of a conventional fume tube, FIG. 8 is a cross-sectional view of the relevant portion, and FIG. 9 is a perspective view showing another embodiment of the present invention.
FIG. 10 is a development view of that of FIG. 9, and FIGS. 11 to 13 are front views showing modified examples of the stud pin. 1 ... Tube 2 ... Annular frame 5 ... Welded part

Claims (1)

[Scope of utility model registration request] 1. A tubular body and an annular frame body provided at an end edge of an opening of the tubular body, the annular frame body being formed by bending a long steel plate into an annular shape and welding both ends thereof. In the fume tube, the both ends of the steel plate to be welded are formed in a concavo-convex shape that meshes with each other, and a plurality of pins are projectingly provided on the inner peripheral surface of the annular frame body that interferes with the tube body. Fume tube characterized by.