KR102810488B1 - Connecting device for metal pipes - Google Patents

Abstract

A metal pipe connecting device including an insertion portion provided at one end of a first metal pipe, an expansion portion provided at one end of a second metal pipe, and a locking bolt, wherein the expansion portion is provided with a plurality of locking holes penetrating a wall of the expansion portion, a ring-shaped protrusion is provided along an outer circumference of the insertion portion, the insertion portion is inserted into the expansion portion and the insertion portion and the expansion portion are combined in a combined state, and in the combined state, a separation space is provided between the inner circumference of the expansion portion and the outer circumference of the insertion portion, and the separation space includes a first separation space at a front end side of the insertion portion and a second separation space at a front end side of the expansion portion based on the protrusion, two locking holes form a pair, and the locking bolt is inserted so as to penetrate the pair of locking holes and the second separation space to lock the combined state to form a locked state, and in the locked state, the locking bolt is caught on the protrusion to prevent the insertion portion from arbitrarily moving backward and the combined state from becoming loose.

Description

{Connecting device for metal pipes}

The present invention relates to a connecting device provided at the end of a metal pipe to connect the metal pipe and lock the connection.

When transporting fluids over long distances using pipes, multiple pipes are sometimes connected to each other.

The methods used to connect pipes include a method of forming a flange at the end of a pipe and connecting it, a method of inserting the end of a pipe into a coupling and connecting it, and a method of forming a spiral at the end of a pipe and connecting it with a screw.

When connecting pipes, the larger the diameter of the pipe, the more difficult it is to ensure airtightness at the connection. In the flange connection method, airtightness is maintained by inserting airtightness material between the flange plates, but if the connected pipes are not in a horizontal state due to ground subsidence or vibration, the flange joint surface may not maintain sufficient joint strength, which may damage airtightness. In the case of using a connection sleeve, airtightness is maintained by inserting airtightness material into the joints of the pipes on both sides inside the connection sleeve. This method using a connection member not only requires a separate connection member, but also has problems such as complicated construction.

In addition, in the case of large-diameter metal pipes installed horizontally, the downward pressing force of the sealing member may be strong due to the load of the pipe itself and the load of the passing fluid, resulting in excessive pressing. If such downward excessive pressing occurs, the pressure applied to the upper direction of the sealing member may be reduced, and the sealing effect due to the elasticity of the sealing member may not be sufficiently secured in the upper direction.

Prior art patent No. 10-0909887 relates to a sewer pipe for fixing connection, in which a separate connecting device is attached to pipes to be connected, and then the pipes are connected through this connecting device. A groove is formed by digging a part of the outer surface of the insertion part of the connecting device, and a locking bolt is inserted into this groove to fix the connection. However, digging the outer surface of the insertion part may damage the insertion part, so it is not suitable for pressure pipes. The method of digging the outer surface of the insertion part can be applied when the wall thickness of the insertion part is thick. Normally, the thickness of a metal pipe is much thinner than that of a plastic pipe, so the structure of digging the outer surface of the insertion part to form a groove is difficult to apply. If the wall of the metal pipe is made thick, there is a problem that the weight of the pipe becomes excessively heavy.

Patent No. 10-0909887

The present invention aims to provide a connecting device capable of easily connecting metal pipes and easily locking the connection.

The present invention aims to provide a connecting device having excellent pressure resistance and airtightness at a portion where metal pipes are connected.

A metal pipe connecting device according to the present invention includes an insertion portion provided at one end of a first metal pipe, an expansion portion provided at one end of a second metal pipe, and a locking bolt.

The expansion member is provided with a plurality of locking holes penetrating the wall of the expansion member.

A ring-shaped protrusion is provided along the outer surface of the insert.

The insertion part is inserted into the expansion part, and the insertion part and the expansion part are combined in a combined state. In the combined state, there is a separation space between the inner surface of the expansion part and the outer surface of the insertion part, and the separation space includes a first separation space at the front end of the insertion part and a second separation space at the front end of the expansion part based on the protrusion.

The locking holes are paired in two, and the locking bolt is inserted through the pair of locking holes and the second separation space to lock the joint state of the pipe and create a locked state.

When the pipe joint is locked, the locking bolt catches on the protrusion, preventing the insertion part from moving backwards arbitrarily against the user's will and loosening the pipe joint.

The protrusion height of the projection may be greater than or equal to the wall thickness of the insert.

The locking hole may have a locking hole extension portion protruding from the outer surface of the expansion member.

The locking bolt may be in tangential contact with the inner periphery of the expansion member or the outer periphery of the insert member.

A ring-shaped sealing member made of elastic material is installed in the first separation space, and may come into contact with the outer surface of the insertion part and the inner surface of the expansion part.

The protrusion may have a protrusion height of the lower section that is higher than the protrusion height of the upper section by an additional protrusion portion, and the additional protrusion portion may also function as an anti-overpressure member.

A foreign matter prevention cap made of resin may be inserted into the annular space between the tip of the expansion section and the insert section to prevent the inflow of foreign matter. The foreign matter prevention cap may include an over-pressure prevention member made of metal in its lower section.

Meanwhile, the connecting device of the present invention may be provided with two sealing members isolated from each other, a pressure check space defined by the two sealing members and the outer surface of the insertion part and the inner surface of the expansion part, and a pressure check hole penetrating the wall of the expansion part and communicating with the pressure check space.

According to the present invention, metal pipes can be easily joined and the joining can be easily locked.

According to the present invention, the pressure resistance and airtightness of the portion where the metal pipe is connected are excellent.

According to the present invention, metal pipes having thin wall thickness can be connected.

The present invention can solve the problem of leakage due to excessive pressing and, furthermore, can be expected to have the effect of extending the life of the pipe.

In particular, the present invention is advantageous in connecting large-diameter metal pipes having a diameter of 80 mm or more and performing sealing.

FIG. 1 illustrates step-by-step a method for connecting metal pipes using a connecting device according to an embodiment of the present invention.
Figure 2 is a perspective view of a pipe connecting device according to an embodiment of the present invention.
FIG. 3 is a longitudinal cross-sectional view showing a state in which an insertion portion of a first metal pipe is inserted into an expansion portion of a second metal pipe according to an embodiment of the present invention.
FIG. 4 is a perspective view of a pipe having a locking hole extension portion according to an embodiment of the present invention.
Figures 5 and 6 are cross-sectional views of a point where a locking hole is located in a connected pipe according to an embodiment of the present invention.
Figure 7 is a perspective view of a metal pipe according to an embodiment of the present invention.
Figures 8 and 9 are cross-sectional views of a connecting device according to an embodiment of the present invention.
FIGS. 10 and 11 are cross-sectional views of points where protrusions are located in connected pipes according to embodiments of the present invention.
Figure 12 is a perspective view of a metal pipe according to an embodiment of the present invention.
Figures 13 to 17 are cross-sectional views of a connecting device according to an embodiment of the present invention.
Fig. 18 is a perspective view of a foreign matter prevention cap according to an embodiment of the present invention.

In the present invention, 'lower' means the direction in which gravity faces when piping a metal pipe horizontally, and 'upper' means the opposite direction.

In the present invention, the 'retraction' of the pipe refers to movement in the direction in which the pipe is released from its joint.

The present invention relates to a connecting device provided in a metal pipe itself, and the metal pipe to be connected is made of a material such as stainless steel, steel pipe, or cast iron.

The metal pipe connecting device of the present invention may have a sealing member, a pressure sensor, a compression member, an anti-over-pressure member, or a foreign matter prevention cap.

The two ends of the metal pipes to be connected may have the same shape or different shapes. For example, a metal pipe may have only an insertion part or only an expansion part at both ends, or may have an insertion part at one end and an expansion part at the other end. The connected objects are a metal pipe having an insertion part and a metal pipe having an expansion part, and the metal pipes are connected by inserting the insertion part into the expansion part.

Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 illustrates a method for connecting metal pipes using a connecting device according to an embodiment of the present invention step by step. FIG. 1 (a) shows a state in which a first metal pipe (1) and a second metal pipe (2) are separated, FIG. 1 (b) shows a state in which the first metal pipe (1) and the second metal pipe (2) are joined, and FIG. 1 (c) shows a state in which the first metal pipe (1) and the second metal pipe (2) are joined in a locked state.

Figure 2 is a perspective view of a pipe connecting device according to an embodiment of the present invention.

Figure 3 is a cross-sectional view showing a state in which the insertion portion (110) of the first metal pipe (1) is inserted into the expansion portion (120) of the second metal pipe (2) according to an embodiment of the present invention. This insertion state can be locked using a locking bolt (130).

FIG. 4 is a perspective view of a pipe having a locking hole extension portion (121a) according to an embodiment of the present invention, and FIGS. 5 and 6 are cross-sectional views of a point where a locking hole (121) is located in a connected pipe according to an embodiment of the present invention.

Fig. 7 is a perspective view of a metal pipe according to an embodiment of the present invention, and Figs. 8 and 9 are cross-sectional views of a connecting device according to an embodiment of the present invention. Figs. 10 and 11 are cross-sectional views of a point where a protrusion (111) is located in a connected pipe according to an embodiment of the present invention, and Fig. 12 is a perspective view of a metal pipe according to an embodiment of the present invention. Figs. 13 to 17 are cross-sectional views of a connecting device according to an embodiment of the present invention, and Fig. 18 is a perspective view of a foreign matter prevention cap (180) according to an embodiment of the present invention.

Insert

The first metal pipe (1) to be connected has an insertion portion (110) at one end.

The insertion portion (110) has a cylindrical shape and has a ring-shaped protrusion (111) on its outer surface.

The ring-shaped protrusion (111) may be one or two or more. Fig. 7 is an example of one protrusion (111), and Fig. 12 is an example of two protrusions (111).

The insertion part (110) having one protrusion (111) is advantageous for connecting metal pipes having a diameter of 80 mm to 500 mm and a maximum pressure of 10 bar. The insertion part (110) having two protrusions (111) can also use a plurality of U-bolts, for example, as locking bolts (130), and is advantageous for connecting metal pipes having a diameter of 500 mm to 1500 mm and a maximum pressure of 5 bar.

The side surface of the protrusion (111) may be a plane perpendicular to the longitudinal center line of the first metal pipe (1), but may not be perpendicular or may not be a plane.

When the insertion part (110) is inserted into the expansion part (120) and the metal pipe is combined, and the locking bolt (130) inserted through the locking hole (121) comes into contact with the side of the protrusion (111), the locking bolt (130) acts as a lock and the protrusion (111) acts as a catch on which the lock is engaged, thereby preventing the insertion part (110) from being arbitrarily retracted against the user's will, thereby loosening or releasing the connection of the pipe.

Referring to Fig. 3, the locking function of the locking bolt (130) is advantageous when the protrusion height (h1) of the protrusion (111) protruding from the outer surface of the insertion portion (110) is high, because the lock is locked more reliably.

In the case where a groove is formed by digging the wall of the insertion portion as in the prior art patent No. 10-0909887, so that the locking bolt passes through the inside of the groove and the groove serves as a catch for the locking bolt, the dug portion of the wall inevitably reduces the ability to resist external force applied to the wall. In addition, although the groove must be deep to more reliably engage the lock, it is completely impossible to make the depth of the groove greater than the wall thickness of the insertion portion. Furthermore, the deeper the groove, the lower the resistance of the wall to external force.

In contrast, in the present invention, there is no particular limitation on the protrusion height (h1) of the protrusion (111). The protrusion height (h1) of the protrusion (111) may have a size equal to or greater than the wall thickness (t1) of the insertion portion (110). Since there is no limitation on the protrusion height (h1) of the protrusion (111), a locking bolt (130) having a large body diameter can also be used without particular limitation. In addition, compared to the prior art of digging a groove in the wall of the insertion portion (110), when the protrusion (111) is formed in the wall of the insertion portion (110) as in the present invention, the resistance capacity of the wall against external force applied to the wall is improved.

Confirmation Department

The second metal pipe (2) to be connected has an expansion member (120) at one end. The expansion member (120) has a cylindrical shape and is sized to accommodate the insertion member (110) of the first metal pipe (1).

The expansion member (120) has two or more locking holes (121) penetrating the wall. The locking holes (121) are formed chordwise along the inner circumference of the expansion member (120). Two locking holes (121) formed on the same axis form a pair, and the expansion member (120) may have two or more pairs of locking holes (121).

As shown in FIGS. 7, 8, and 12, the expansion member (120) may be a two-stage structure composed of an outer end (120a) and an inner end (120b). The outer end (120a) is a portion toward the front end of the expansion member (120), and the inner diameter of the outer end (120a) is larger than the inner diameter of the inner end (120b), and the inner diameter of the inner end (120b) is larger than the outer diameter of the insertion part (110). In this case, a sealing member (140), a protrusion (111) of the first metal pipe (1), and a locking bolt (130) may be arranged in the area of the outer end (120a). The difference between the inner diameter of the inner end (120b) and the outer diameter of the insertion portion (110) may be less than half the difference between the inner diameter of the outer end (120a) and the outer diameter of the protrusion (111). The inner end (120b) having a smaller inner diameter than the outer end (120a) stabilizes the connected metal pipe. In addition, the inner end (120b) may also function as an over-pressure prevention member (200).

When the insertion part (110) of the present invention is inserted into the expansion part (120) and connected to each other, a separation space (190) is created between the inner surface of the expansion part (120) and the outer surface of the insertion part (110). The separation space (190) includes a first separation space (191) on the front end side of the insertion part (110) with respect to the protrusion (111) and a second separation space (192) on the opposite side (i.e., on the front end side of the expansion part).

Meanwhile, when pressure is applied internally while the pipes are joined, the pipe receives a force that causes it to retreat in the longitudinal direction. If the internal pressure is large, the locking bolt (130) may be damaged by a strong shear force when the pipe retreats in the longitudinal direction.

Breakage of the locking bolt (130) can be prevented by expanding the area where the locking bolt (130) comes into contact with the locking hole (121). To this end, in the present invention, the locking hole (121) may be extended from the outer surface of the expansion member (120).

Figure 4 illustrates an example in which a locking hole extension portion (121a) protrudes from the outer surface of an expansion member (120), and shows the locking hole extension portion (121a) separately and enlarged. The locking hole extension portion (121a) is a part of the locking hole (120).

The locking hole extension part (121a) can be manufactured separately and attached to the expansion part (120), or it can be formed integrally with the pipe during the manufacture of the pipe.

FIG. 5 and FIG. 6 are cross-sectional views of a pipe at a point where a locking hole (121) is located when the pipe is connected according to an embodiment of the present invention. FIG. 5 is an example in which there is no locking hole extension portion (121a) protruding from the outer surface of the expansion portion (120), and C1 is an area where the locking hole (121) and the locking bolt (130) come into contact. FIG. 6 is an example in which there is a locking hole extension portion (121a), and C2 is an area where the locking hole (121) and the locking bolt (130) come into contact. The case of C2 is more advantageous than the case of C1 in preventing damage to the locking bolt (130) due to shear force.

locking bolt

The locking bolt (130) is inserted into the locking hole (121) and comes into contact with the side of the protrusion (111) provided in the insertion portion (110), thereby preventing the protrusion (111) from accidentally or suddenly retracting and releasing the connection state of the metal pipe against the user's intention.

The locking holes (121) are paired in two, and the locking bolt (130) is inserted so as to penetrate the pair of locking holes (121) and passes through the second separation space (192). The locking bolt (130) penetrating the pair of locking holes (121) may tangentially contact the inner circumference of the expansion portion (120) or the outer circumference of the insertion portion (110).

The locking bolt (130) may be a straight type penetrating a pair of locking holes (121), a U-bolt type penetrating two pairs of locking holes (121), or may have other shapes.

The locking bolt (130) inserted into the locking hole (121) can be fixed by fastening a nut.

Absence of confidentiality

When metal pipes are connected by fitting, a gap (190) is created between the inner surface of the expansion portion (120) and the outer surface of the insert portion (110), which may weaken the airtightness. Therefore, in order to maintain airtightness, an airtight member (140) such as an elastic O-ring may be used.

The confidentiality member (140) is provided in the first separation space (191) and contacts the outer surface of the insertion portion (110) and the inner surface of the expansion portion (120).

Over-pressure prevention member

If the lower part of the sealing member (140) is over-pressed and the upper part is under-pressed due to the load of the metal pipe and the load of the fluid flowing inside the metal pipe, the sealing effect of the sealing member (140) may be reduced.

Excessive compression is likely to occur in large-diameter metal pipes. However, even in the case of small-diameter pipes, if the connecting portion is bent or bent due to vibration or uneven settlement, excessive compression may occur on one side of the sealing member (140) and the other side may become relatively loose, which may reduce the sealing performance.

The connecting device of the present invention may be provided with an anti-pressure member (200) that prevents a decrease in confidentiality. One or more anti-pressure members (200) may be provided.

The over-pressure prevention member (200) may have a form indicated by drawing symbols 200a, 200b, 200c, and 200d.

As shown in FIGS. 9 and 10, if the protrusion height of the lower section of the protrusion (111) on the first metal pipe (1) is made higher than the protrusion height of the upper section, the additional protrusion height portion (200a) of the lower section can function as an over-pressure prevention member (200).

In addition, as shown in Fig. 11, a metal plate (200b) inserted into the gap between the lower section of the protrusion (111) and the inner surface of the expansion portion (120) of the second metal pipe (2) may be an anti-overpressure member (200).

In FIGS. 7, 8, and 12, among the two-stage structures (120a, 120b) of the expansion member (120), the inner stage (120b) may be an anti-pressure member (200).

In Figures 16 to 18, a metal anti-pressure member (200) forms part of a foreign matter prevention cap (180).

Foreign body prevention cap

The foreign matter prevention cap (180) prevents foreign substances from entering the separation space (190). The foreign matter prevention cap (180) may be an annular shape made of resin material, and may be installed in the annular space between the tip of the expansion portion (120) and the insertion portion (110).

In FIGS. 15 to 18, the foreign matter prevention cap (180) has an annular insertion projection (180a), and the annular insertion projection (180a) is inserted into an annular space between the tip of the expansion portion (120) and the insertion portion (110). The lower section of the annular insertion projection (180a) may be a metal anti-pressure member (200). In FIG. 17, the annular insertion projection (180a) is provided with a member insertion groove (180b), and the anti-pressure member (200) is inserted into the member insertion groove (180b).

Pressure measuring means

The connecting device according to the present invention may also be provided with means for measuring the pressure of the metal pipe.

The connecting device according to the present invention may have one sealing member (140), but may also have two or more. In FIG. 13, there are two sealing members (140) separated by a metallic isolation member (142). In addition, there is a pressure check space (150) partitioned by these two sealing members (140), the outer surface of the insertion part (110), and the inner surface of the expansion part (120), and there is also a pressure check hole (151) penetrating the wall of the expansion part (120) and communicating with the pressure check space (150). If the pressure check space (150) and the pressure check hole (151) exist in this way, a hydraulic test can be performed to determine the sealing performance by putting water in the pressure check space (150), or a pressure sensor (161) can be attached to the pressure check hole (151) to measure the pressure change in the pressure check space (150). For example, paint can be put in the pressure check space (150) so that the paint comes out when the seal fails, and a sensor that conducts electricity when it comes into contact with water can be put in so that an LED turns on when the seal fails.

In addition, an annular pressure sensor (161) may be installed on the surface of the annular insertion protrusion (180a) of the foreign substance prevention cap (180) or in the groove of the annular insertion protrusion (180a). The foreign substance prevention cap (180) of FIG. 18 is equipped with an annular pressure sensor (161).

Compression member

The metal pipe connecting device of the present invention may be provided with a compression member (170) that offsets thermal expansion of the metal pipe. The compression member (170) has an elastic structure formed of rubber, silicone, a corrugated pipe, or the like.

Fig. 14 shows an example in which a compression member (170) is provided between a protrusion (111) and a sealing member (140). When thermally expanded, the protrusion (111) compresses the compression member (170), and the compression member (170) can absorb changes in pipe length due to thermal expansion. In a pipe with significant thermal changes, a compression member (170) may also be installed between the protrusion (111) and the locking bolt (130).

1: 1st metal pipe 2: 2nd metal pipe
110: Insert 111: Protrusion
120: Expansion section 121: Locking hole
121a: Locking hole extension 130: Locking bolt
140: Confidentiality 141: Confidentiality washer
142: Isolation space 150: Pressure check space
151: Pressure check hole 161: Pressure sensor
170: Compression member 180: Foreign matter prevention cap
190: Separation space 191: First separation space
192: Second separation space 200: Over-pressure prevention member

Claims (9)

A metal pipe connecting device including an insertion part (110) provided at one end of a first metal pipe (1), an expansion part (120) provided at one end of a second metal pipe (2), and a locking bolt (130),
The above expansion member (120) is provided with a plurality of locking holes (121) penetrating the wall of the above expansion member (120).
A ring-shaped protrusion (111) is provided along the outer surface of the above insertion portion (110).
The above insertion part (110) is inserted into the above expansion part (120) so that the insertion part (110) and the expansion part (120) are combined into a combined state.
In the above-mentioned combined state, there is a separation space (190) between the inner surface of the expansion member (120) and the outer surface of the insertion member (110).
The above separation space (190) includes a first separation space (191) at the tip of the insertion part (110) based on the protrusion (111) and a second separation space (192) at the tip of the expansion part (120).
The above locking hole (121) includes a locking hole extension portion (121a) protruding from the outer surface of the expansion member (120),
The above locking holes (121) are four or more, and two form a pair.
The above locking bolt (130) is inserted so as to penetrate the pair of locking holes (121) and the second separation space (192) to lock the combined state and create a locked state.
In the above locked state, the locking bolt (130) is caught on the protrusion (111), thereby preventing the insertion part (110) from moving backward arbitrarily and the combined state from becoming loose.
A connecting device for metal pipes. In the first paragraph, a connecting device for a metal pipe in which the protrusion height (h1) of the protrusion (111) is larger than the wall thickness (t1) of the insertion portion (110). delete In the first paragraph, a connecting device of a metal pipe in which the locking bolt (130) is in tangential contact with the inner circumference of the expansion member (120). In the first paragraph, a connecting device of a metal pipe in which the locking bolt (130) is in tangential contact with the outer circumference of the insertion portion (110). In the first paragraph, a metal pipe connecting device having a ring-shaped sealing member (140) made of elastic material that is installed in the first separation space (191) and contacts the outer surface of the insertion portion (110) and the inner surface of the expansion portion (120). In the first paragraph, the protrusion (111) is a metal pipe connecting device in which the protrusion height of the lower section is higher than the protrusion height of the upper section by an additional protrusion portion (200a), and the additional protrusion portion (200a) functions as an over-pressure prevention member (200). In the first paragraph, a metal pipe connecting device having two sealed members (14) isolated from each other; a pressure check space (150) defined by the two sealed members (140) and the outer surface of the insertion part (110) and the inner surface of the expansion part (120); and a pressure check hole (151) penetrating the wall of the expansion part (120) and communicating with the pressure check space (150). In the first paragraph, a foreign matter prevention cap (180) made of resin is inserted into the annular space between the tip of the expansion member (120) and the insertion member (110), and the foreign matter prevention cap (180) includes a metal over-pressure prevention member (200) in the lower section thereof. A metal pipe connecting device.