JPS6014689A - Insertion type pipe joint for thin metallic pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a plug-in type pipe joint that is made of the same material as the thin-walled metal pipe to be joined, has an enlarged pipe portion formed at the end of the pipe, and has a sealing hole on its inner surface. a contraction link having an inner surface which is connected to the expanded tube portion of the plug-in type pipe fitting body in advance and which reduces the diameter of the expanded tube portion of the plug-in type pipe joint body by suppressing movement; The pipe method, which temporarily fastens the thin-walled metal pipe to be joined which is fitted inside the shrink ring and inserted into the connection body between the plug-in type pipe joint body and the shrink ring, has workability and sealing performance using a retaining ring. This invention relates to a plug-in type pipe joint for thin-walled metal pipes that has excellent properties.

Traditionally, thick inner pipes such as lead pipes and vinyl pipes have been used as water pipes and other liquid transfer pipes, but each has drawbacks such as strength and temperature adaptability, so Instead, in recent years, thin-walled metal pipes, typified by stainless steel pipes, have come into widespread use. Taking stainless steel pipes, which are the most commonly used thin-walled metal pipes, as an example, thin-walled stainless steel pipes have excellent strength and are resistant to temperature changes, but they are harder and more durable than sticky materials. Because the pipes are thin, it is impossible to perform processes such as thread cutting, so the following method of joining has been adopted using pipe joints.

As shown in Fig. 1, the sleeve C is assembled by screwing the loop-shaped tightening member A, which has a female thread on the inner surface, to the joint body B, which has a male thread on the outer surface of the end. A method has been adopted in which the sleeve C is pressed against the outer circumferential surface of the thin-walled metal pipe to be joined and the end of the joint body B by pressing one end of the pipe to form a liquid seal. In the case of the mouth,
In general, the tightening member A and the joint body B are harder than the sleeve C, and in order to increase the pressure resistance of the joint in the axial direction and to ensure a more secure seal, the tightening member A and the joint body B are tightened (q. As shown in FIG. 1, the end of the sleeve C on the side of the tightening member A was bitten into the outer circumferential surface of the thin metal pipe to be welded.

However, when such a pipe joint is used, the tightening member A must have a female thread on the inner surface, and the joint body B must also have a male thread on the outer surface of the end. Therefore, thick-walled castings are used for both, which increases the size and weight of the necessary components, resulting in an increase in cost and poor economic efficiency.

Tokuko Sho 5 b-46! is a method for joining thin-walled metal tubes that prevents such defects. l! A method using a plug-in pipe joint disclosed in No. 13 [Coupling device for joining cylindrical members] has been put into practice. In this method, the plug-in pipe fitting body is made of a relatively thin metal material, and a contraction ring with a truncated conical inner circumferential surface is fitted onto the outer periphery of the pipe fitting body from the end side of the pipe fitting body. This is a method of joining the pipe fitting body and the thin-walled metal pipe to be joined by reducing the diameter of the end of the pipe fitting body by the opening, and bringing the thin-walled metal pipe to be joined and the pipe fitting body into close contact at the reduced diameter part. . Method C is an excellent method in terms of economy, but if method C is to be implemented, a shrink ring must be loosely fitted in advance to the outer periphery of the thin metal pipe to be joined which is inserted into the plug-in type pipe fitting body. Insert each of the thin-walled metal pipes to be welded into the plug-in type pipe fitting body from both sides, and then simultaneously press and move the contraction rings on both sides toward the joint body using a compression tool to reduce the diameter of both ends of the pipe joint body. Therefore, this method is only possible when the pipe fitting body is in the shape of a straight pipe and the forces acting on each contraction ring are the same opposing forces. This was impossible in cases where the main body force is curved, such as an elbow, or where there is no insertion part for a thin metal tube on the other side, such as in a branch pipe such as a tee.

In recent years, in order to prevent such defects, as shown in Fig. 2, a plug-in type pipe fitting main body E is provided with a protrusion [a] on the outer periphery that engages with a fixing claw of a pressing tool. A combination h (proposed) of a shrink ring F and a shrink ring F is proposed.However, providing this protrusion Ea would be expensive because the plug-in pipe joint body E would have to be manufactured by means such as casting. In addition, there is a drawback that the thin-walled metal pipe to be joined and the plug-in pipe fitting main body E are formed of different materials, causing potential corrosion, resulting in concerns about sealing performance. In addition, even if the thin-walled metal pipe to be joined is inserted into the plug-in type pipe fitting body E in an attempt to temporarily assemble piping, the shrink ring F is only loosely fitted around the outer periphery of the plug-in type pipe fitting body E. Because of this, temporarily assembling the pipes is not possible, or when attempting to perform joining work by attaching a suppression tool to the plug-in pipe fitting body E, the thin-walled metal pipes to be joined or the shrink ring F may be attached to the plug-in pipe fitting body E. There was a drawback of poor workability, such as the main body E easily falling downward.

The present inventors have endeavored to eliminate the drawbacks of the above-mentioned conventional plug-in pipe joints used for plug-in joints of thin-walled metal pipes.]
As a result of the investigation, it was found that a cylindrical expansion tube of a predetermined length with an inner diameter slightly larger than the outer diameter of the thin-walled metal tube to be welded was attached to the tube end of a thin-walled metal tube of the same age as the thin-walled metal tube to be welded and whose inner diameter was approximately +ili+-. The plug-in type pipe fitting body is formed with a section, and the expanded tube part of the plug-in type pipe fitting body is connected to the plug-in type pipe fitting body by being fitted onto the outside of the plug-in type pipe joint body in advance and is joined by pressing movement. A contracting diameter ring having an inner surface that reduces the diameter to less than the outer diameter of the thin-walled metal pipe, a sealing material attached to the inner surface of the expanding section of the plug-in pipe fitting body, and a sealing material fitted inside the shrinking ring. A method of temporarily fixing thin-walled metal pipes to be joined that are inserted into the connecting body of the plug-in type pipe fitting body and the contraction ring. The present invention was completed by researching a plug-in type pipe joint for thin-walled metal pipes that has reliable sealing properties without the need for any trouble, and has good workability.

That is, in the present invention, an enlarged tube portion having a predetermined length and an inner diameter slightly larger than the outer diameter of the thin-walled metal tube to be welded is formed at the tube end of a thin-walled metal tube made of the same material and having approximately the same diameter as the thin-walled metal tube to be welded. At the large diameter end of the plug-in type pipe fitting body and the truncated conical inner surface, there is also a large diameter cylindrical inner surface at the small diameter end with an inner diameter slightly smaller than the outer diameter of the expanded tube part of the plug-in type pipe fitting body. has an inner surface in which small diameter cylindrical inner surfaces each having a small inner diameter are formed in succession to reduce the inner diameter of the expanded tube portion of the plug-in type pipe joint body to less than the outer diameter of the thin-walled metal tube to be joined; a contraction ring that is connected to the plug-in pipe fitting main body by fitting the end of the pipe-expanding part of the plug-in pipe fitting main body into a slightly reduced diameter state with a cylindrical inner surface; a sealing material adhered to the inner surface of the expanded tube portion of the plug-in pipe joint body so that the thin-walled metal pipe to be joined can be inserted into the connecting body consisting of the plug-in pipe joint body and the shrink ring; The plug-in type pipe joint body is fitted inside the small-diameter cylindrical inner surface of the ring and is interposed between the outer surface of the thin-walled metal tube to be joined, which is inserted into the connecting body, and the small-diameter cylindrical inner surface of the shrink ring. The present invention provides a plug-in pipe joint for thin-walled metal pipes, which is characterized by comprising a retaining ring and a retaining ring.

Hereinafter, the plug-in pipe joint for thin-walled metal pipes according to the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a side view (2) showing a cross section of the right half of one embodiment of the plug-in pipe joint for thin-walled metal pipes according to the present invention, and FIG. 4 shows the thin-walled metal pipes to be joined according to the embodiment of FIG. An explanatory diagram showing a cross section of the right half of the joined state, FIG. An explanatory diagram showing in cross section the right half of the state in which the thin-walled metal pipes to be joined are joined according to the embodiment shown in the figure, and FIG. FIG. 8 is a sectional view taken along the line X--X in FIG. 7.

In the drawing, reference numeral 1 denotes a plug-in type pipe joint body, which is composed of a thin-walled metal tube with the same thickness and approximately the same diameter as the thin-walled metal tube 5 to be joined, and the inner diameter of the tube end is the same as that of the thin-walled metal tube 5 to be joined. An expanded tube portion 1a having a predetermined length slightly longer than the outer diameter of the metal tube 5 is formed, and therefore, the thin-walled metal tube 5 to be joined is formed in the expanded tube portion 1a.
can be inserted freely. 2 is a contraction ring whose inner surface consists of three inner surfaces. That is, the inner surface of the central part has a truncated conical shape facing inward 2a, and a large diameter cylindrical inner surface 21+ having an inner diameter slightly smaller than the outer diameter of the expanded tube portion 1a of the plug-in pipe joint body 1 is continuous on the large diameter side. Ori,
Further, a small-diameter cylindrical inner surface 2C having a small inner diameter that reduces the inner diameter of the expanded tube portion 1a of the plug-in type pipe joint body 1 to less than the outer diameter of the thin-walled metal tube 5 to be joined is continuous to the small-diameter side of the truncated conical inner surface 2a. In this way, the shrink ring 2 is attached to the three inner surfaces 2.
It has an inner surface formed continuously by a, 211, and 2C. As shown in FIGS. 3 and 5, the contraction ring 2 is attached to the large-diameter cylindrical inner surface 2 with a + on the expanded tube portion 1a of the plug-in type pipe fitting body 1, with the end portion of the expanded tube portion 1a slightly contracted in diameter. It is fitted onto the outside and forms a connecting body with the plug-in pipe joint main body 1. If the edge of the shrink ring 2 on the large diameter cylindrical inner surface 21) side is chamfered as shown in FIGS. This is preferable in terms of facilitating the pressing movement described later. Reference numeral 3 denotes a sealing material, which is adhered to the inner surface of the expanded pipe portion 1a of the plug-in pipe joint body 1 in such a state that the thin-walled metal tube 5 to be joined can be inserted into the connecting body. This sealing material 3 may be attached after the shrink ring 2 is connected to the plug-in type pipe fitting main body 1, but it can be applied in advance to the expanded tube portion 1a of the plug-in type pipe joint main body 1 before the shrink ring 2 is connected. It may also be attached to.

Reference numeral 4 denotes a pipe stopper ring which is fitted inside the small-diameter cylindrical inward direction 2C of the contraction ring 2, and when the thin-walled metal tube 5 to be joined is inserted into the connecting body, the outer surface 5a of the contraction ring and the contraction ring 4 are fitted. This is to prevent the thin-walled metal tube 5 inserted between the small-diameter cylindrical inner surface 2C of the tube 2 and the small-diameter cylindrical inner surface 2C of the tube 2 from coming out in the direction of the container, and to temporarily fasten the tube 5. There are several types of this tube method [pull stopper ring 4].
The cylindrical body 4 is fitted into the small diameter cylindrical inner surface 2C of the
The outer surface 5 of the thin-walled metal pipe 5 to be joined is inserted into the connecting body consisting of the plug-in type pipe fitting main body 1 and the contraction ring 2 at the tip of a.
A slanted claw portion 4L+ that presses against the tip 4L+ is formed, and a locking portion 4C that locks onto the end surface 2d on the small-diameter cylindrical inner surface 2C side of the contraction ring 2 is provided at the end opposite to the tip. The pipe ring 4 has a structure shown in FIG. Since the portion 4C is locked to the end 1f[i2d of the contraction ring 2, the retaining ring 4 does not move in the insertion direction.
Since the claw portion 4b is inclined at an obtuse angle with respect to the insertion direction, the thin metal tube 5 to be joined can pass through the claw portion 4[). On the other hand, when the welded thin-walled metal tube 5 that has been inserted once is about to be pulled out, the welded thin-walled metal tube 5 that is in pressure contact with the welded thin-walled metal tube is The claw portion 4b is hooked to the outer surface 5a of the contraction ring 2, and in the pipe method, the cylindrical body portion 4a of the retaining ring 4 comes into strong pressure contact with the small diameter cylindrical inner surface 2C of the contraction ring 2, increasing friction and causing the stop ring 4 to be pulled out.
-1 does not move in the unloading direction, and therefore the thin-walled metal tube 5 to be joined is prevented from being pulled out. The embodiment shown in FIG. 5 is installed in an annular groove 2e formed by a part of the small-diameter cylindrical inner surface 2C of the shrink ring 2, and consists of 10 rings whose inner diameter is smaller than the outer diameter of the thin-walled metal tube 5 to be welded. Pipe method [Pull ring 4. The tube method consisting of the above-mentioned O-ring is such that the retaining ring 4 is extended in the circumferential direction and is therefore contracted in the circumferential direction. A tube method consisting of a thin-walled metal tube 5 and an O-ring that are in pressure contact with each other due to the force applied increases the frictional resistance with the retaining ring 4 and makes sliding difficult; Since it is mounted in the groove 2e of No. 2, it does not move, and therefore, the thin-walled metal tube 5 to be joined is prevented from being pulled out unless it is pulled out with a particularly strong force.

As described above, the plug-in type pipe fitting according to the present invention includes the plug-in type pipe joint main body 1, the shrink ring 2, the sealing material 3, and the pipe fitting ring 4, as shown in FIGS. 3 and 5. It is configured.

Next, the implementation of joining thin-walled metal pipes to be joined using the plug-in pipe joint according to the present invention will be described.

That is, as shown in FIGS. 3 and 5, the thin-walled metal tube 5 to be joined is inserted into the plug-in type pipe joint according to the present invention.

At this time, the tube expansion end portion 1b of the plug-in pipe joint body 1 serves as a stopper. Inserted thin-walled metal tube 5 to be joined
In the pipe method, the action of the retaining ring 4 allows the pipe to be temporarily fixed without falling even when it is inserted vertically from below as shown in Figures 3 and 5, so the pipe is temporarily assembled and the piping condition is adjusted. can do.

After inserting the thin-walled metal pipe 5 to be welded into an appropriate position, use a suitable pressing tool to press the shrink ring 2 and press the large-diameter cylindrical inner surface 2b side first into the plug-in type pipe fitting body 1-. When the expanded tube portion 1a is moved, the expanded tube portion 1a is first reduced in diameter by the large diameter cylindrical inner surface 2b of the contraction ring 2, then by the truncated conical inner surface 2a, and then by the small diameter cylindrical inner surface 2G, and at least @ Small diameter cylindrical inner surface 2C in the later stage
Since the diameter of the inner surface of the expanded tube portion 1a is reduced to less than the outer diameter of the thin-walled metal tube 5 to be joined, as shown in FIGS. The outer surface 5a of the metal tube 5 is in close contact with the outer surface 5a of the metal tube 5 through the sealing material 3, thereby creating a perfect seal. When the contraction ring 2 is moved by pressing, the tube is not pulled out and the ring 4 remains at the pressing start position as shown in FIG. 4 in the case of the small embodiment shown in FIG. In this case, the shrink ring 2 is moved while being attached to the groove 20 of the shrink ring 2, as shown in FIG.

When the plug-in pipe fitting main body 1 has a straight pipe shape, it is not possible to use various known pressing tools to apply the same opposing pressing force to the contraction rings 2 at both ends. It's easy. Furthermore, even if the plug-in type pipe fitting main body 1 is curved or branched and the contraction rings 2 on both sides are not located in opposing positions, when using the plug-in type @ fitting according to the present invention, for example, A pressing force can be applied to each contraction ring 2 separately in the following manner. That is, in FIGS. 7 and 8, 6 is a split-shaped grip piece, and its inner surface 6a has an inner diameter that almost matches the outer diameter of the expanded tube end portion 11) of the plug-in type pipe joint body 1. The outer surface 61] is securely held by a U-shaped fixing claw of a suppression tool, which will be described later. Reference numeral 7 denotes a pressing tool that applies force to reduce the diameter of the end of the plug-in pipe joint body 1 (the attached sealing material is omitted to simplify the drawing). Built-in pipe fitting body 1
Grip heath 6 attached to the outer periphery of the tube expansion end portion 1b
is held on the inner peripheral surface of the pressing tool 7, and further the grip heath 6
U to which an opening prevention and opening/closing bar 7b' is attached which securely holds the opening from opening due to the pressing force of the contraction ring 2.
A main body 7a to which a letter-shaped fixing claw 7b is fixed and its main body 1a
It consists of a U-shaped moving pawl 7d that is moved by a hydraulic cylinder 1G mounted on the body to press the contraction ring 2 and move it over the expanded tube portion 1a of the plug-in type pipe joint body 1. In this pressing tool 7, the fixed claw 7b and the movable claw 7
(J and J form a U-shape when the thin-walled metal tube 5 to be joined is inserted into the plug-in type pipe joint body 1 and after the joining operation is completed.) This is because it must be possible to easily attach and detach the plug-in pipe joint body '1.However, in order to join the thin-walled metal pipes 5 to be joined using the plug-in pipe joint according to the present invention, , first, the thin-walled metal tube 5 to be welded is connected so that its tube end is the tube expansion end portion 1b.
(Hereinafter, the description regarding the stop ring 4 will be omitted when removing the pipe.) Next, the pressing tool 7 is attached to the fixing claw 711 so that one grip piece 6 holds the tube expansion end portion 111 of the plug-in type pipe joint body 1.
Also, install the movable claw 7d so that it is located on the opposite side of the shrink ring 2 from the plug-in pipe joint body 1, and then attach the other grip piece 6 to the fixed claw 711, and then attach the opening prevention opening/closing lever 7L) 1 (71) after firmly holding the grip piece 6 with 1 (71
When it is moved to the 1 side, the moving claw 111 presses the contraction ring 2 and moves it over the expansion tube portion la of the insertion type tube iI+main body 1. When the joining of the thin-walled metal pipe 5 to be joined and the plug-in pipe fitting main body 1 is completed in this way, the pressing tool 7
After releasing the hydraulic pressure supplied to the hydraulic cylinder 7G of It is only necessary to remove it from the tube expansion end portion 1b of the plug-in type pipe joint body 1. If the plug-in pipe joint according to the present invention is used like a socket, it is possible to apply a pressing force to each contraction link 2 on both sides separately. It is also easy to join.

The plug-in type pipe joint for thin-walled metal pipes according to the present invention described in detail above has various advantages as listed below, and its industrial value is extremely great.

1) As a plug-in type pipe fitting body, there is no need to use a cast product like the small plug-in type pipe joint body shown in Fig. 2, which has a protrusion on the outer periphery that engages with the fixing claw of a conventional suppression tool. Since the plug-in type pipe fitting main body is made of the same or almost the same thin-walled metal pipe as the thin-walled metal pipe to be joined and is expanded to a predetermined length, the plug-in type pipe fitting main body can be produced easily and inexpensively. There is no concern about potential growth and there is no concern about sealing performance.

2) The disadvantage of not having a protrusion on the outer periphery that reliably engages with the fixing claw of a pressing tool as in conventional plug-in pipe joint bodies is eliminated by utilizing the end of the pipe expansion that occurs when a thin-walled metal pipe is expanded. For example, by holding the entire circumference of the tube expansion end using a pressing tool with a leek-shaped grip piece, and using the tube expansion end as a stopper against the pressing force of the shrink ring. This is an innovative plug-in pipe joint for thin-walled metal pipes that allows joining of both sides of the plug-in pipe joint to be carried out separately, and allows the thin-walled metal pipes to be joined to each other at low cost, easily, and reliably.

() As long as only the joint part of the plug-in type pipe joint body is straight, the other end can be in the shape shown below, so it can be joined in a shape appropriate for various situations. It has the advantage of being able to implement

4) Even if the thin-walled metal pipes inserted into the plug-in type pipe fitting body are not joined, temporary assembly of the pipes is possible because they do not fall off due to the action of the retaining ring, and the joining work can be carried out stably. It has excellent workability.

[Brief explanation of drawings]

Figure 1 is a cross-sectional side view of the right half of a conventional thin-walled metal pipe @ fitting in use; Figure 2 is a cross-sectional side view of the right half of a conventional plug-in fitting for thin-walled metal pipes; Fig. 3 is a side view showing the right half of an embodiment of the plug-in pipe joint for thin-walled metal pipes according to the present invention in cross section, and Fig. 4 shows the state in which the thin-walled metal pipes to be joined are joined by the embodiment of Fig. 3. Shown as a cross section of the right half? i
Explanatory drawings, FIG. 5 is a side view in cross section of the right half of another embodiment of the plug-in pipe joint for thin-walled metal pipes according to the present invention, and FIG. FIG. 7 is an explanatory diagram showing a cross section of the right half of the joined state; FIG. 7 is a side view showing a cross section of the right half of an example of a joined state of the plug-in pipe joint for thin-walled metal pipes according to the present invention; FIG. is shown in Figure 7 (Puru x-X
FIG. 1...Plug-in type pipe joint body 1a...Tube expansion part 11)...Tube expansion end part 2...Contraction ring 2a...Frusto-conical inner surface 21+...Large Cone circular inner surface 2C... Small diameter cylindrical inner surface 2 (1... End surface 2e... Groove 3... Seal material 4... Piping method is stop ring 4a... Cylindrical body part 4b... Claw part 4G... Locking part 4G b... Thin-walled metal tube to be joined 5a... External surface 6... Grip heath 6a... Inward direction 6 ( )...Outer surface 7...Suppression tool 1a...Body 7...Fixing claw 11)'...Opening prevention opening/closing lever 7C...
・Hydraulic cylinder 7d...Moving claw patent applicant Nisshin Steel Co., Ltd. Fig. 1R Fig. 2 Fig. 5 Fig. 6

Claims (1)

[Scope of Claims] 1. Forming an enlarged tube portion of a predetermined length at the tube end of a thin-walled metal tube made of the same material and having approximately the same diameter as the thin-walled metal tube to be welded, the inner diameter of which is slightly larger than the outer diameter of the thin-walled metal tube to be welded. The large diameter end of the plug-in type pipe fitting main body and the truncated conical inner surface have a large diameter cylindrical inner surface with an inner diameter slightly smaller than the outer diameter of the expanded tube part of the plug-in pipe fitting main body, and the small diameter end of the truncated conical inner surface The plug type pipe fitting body has an inner surface in which small diameter cylindrical inner surfaces each having a small inner diameter are successively formed to reduce the inner diameter of the expanded tube portion of the plug-in type pipe joint body to less than the outer diameter of the thin-walled metal pipe to be joined. a contraction ring having a large-diameter cylindrical inner surface that is fitted onto the expanded tube part of the plug-in type pipe fitting body with the end of the expanded tube part slightly reduced in diameter and connected to the plug-in type pipe fitting body; a sealing material adhered to the inner surface of the expanded tube portion of the plug-in pipe joint body so that the thin-walled metal pipe to be joined can be inserted into the connecting body consisting of the plug-in pipe joint body and the shrink ring; The plug-in pipe joint is fitted inside the small diameter cylindrical inner surface of the shrink ring and is interposed between the outer surface of the thin-walled metal tube to be joined which is inserted into the coupling body and the small diameter cylindrical inner surface of the shrink ring. A plug-in type pipe joint for thin-walled metal pipes, characterized in that a pipe puller for temporarily fixing the thin-walled metal pipes to be joined inserted into the main body includes a retaining ring. ? A stop ring is fitted into the small-diameter cylindrical inner surface of the shrink ring.The tip of the cylindrical body is a thin-walled metal pipe to be inserted into the connecting body consisting of the plug-in pipe fitting body and the shrink ring. A structure in which an inclined claw part is formed that presses against the outer surface of the contraction ring, and a locking part is provided at the end opposite to the above-mentioned tip to lock the end surface of the small diameter cylindrical inner side of the contraction ring. A plug-in pipe joint for a thin-walled metal pipe according to claim 1, comprising: 3. Pipe extraction [Patent claim of the present invention, in which the retaining ring is attached to an annular groove formed by a part of the small-diameter cylindrical inner surface of the shrink ring, and comprises an O-ring whose inner diameter is slightly smaller than the outer diameter of the thin-walled metal tube to be welded. Plug-in pipe fitting for thin-walled metal pipes as described in item 1 of the scope.