JPH0334543Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a joint for buried pipes, and more specifically, by fastening a fastener to the joint body, the packing provided on the outer periphery of the pipe can be tightened. The present invention relates to a joint for buried pipes that connects pipes by compressing the pipes and biting the outer periphery of the pipes with a biting member.

[Prior art and its problems]

Buried pipes used for water supply piping, etc., are designed to allow for slight angle changes at the joints, and to be able to change angles in the axial direction, taking into consideration cases where they are subjected to external forces such as the weight of vehicles running on the ground or ground subsidence. It is also possible to expand and contract by sliding relative to the joint. Typical joints classified as so-called telescoping flexible joints according to the standards of the Japan Water Works Association include the joints shown in FIGS. 6 and 7.

FIG. 6 shows a state in which the components of the joint are inserted over the buried pipes to be connected, before the connection is completed, and FIG. 7 shows a state in which the connection is completed.

In FIG. 6, 71 is a cap nut, 72 is an O-ring, 73 is a lock ring, 74 is a biting member, and 7
5 is a washer, 76 is a rubber packing, 77 is a joint body, and 78 is a buried pipe to be connected. Buried pipe 7
8 are inserted into the buried pipe in the order shown in the figure from the end 78a side. The biting member 74 is made of an annular coil or the like, and is positioned in a shallow annular groove 78b provided on the outer periphery of the pipe 78. From this state, the cap nut 71 and the joint body are brought close to each other, and the threaded portions 71a and 77a are screwed together, resulting in the state shown in FIG. 7. In this state, the rubber packing 76 is compressed between the joint body 77 and the pipe 78 to keep this portion liquid-tight. At the same time, the biting member 74 is pressed by the similarly inclined inner surface 73a of the lock ring 73 which contacts the inner inclined surface 71b of the cap nut 71, and is fixed to the tube 78 by biting in the groove 78b. As mentioned earlier, this fixing force is set to a level that allows the pipe and joint to slide when an excessive external force exceeding a certain value is applied in the axial direction due to the weight of a car, etc., and this can cause damage to the buried pipe. prevent. Although not shown broken, the other end of the joint main body 77 has a similar configuration, and the buried pipes are successively connected thereto.

As is clear from the figure, the joint configured as described above has a large number of parts. Additionally, in order to prevent loss of parts, these fittings are usually sold with all parts attached to both ends of the fitting body, and then transported to the site where they will be used as is. be. Therefore, when using this joint, it is necessary to disassemble the assembled joint into one set and then assemble it on the pipe as described above. Since there are a large number of parts, this operation takes a relatively long time, and it often happens that the order of inserting each part onto the tube is incorrect and the operation has to be repeated.

[Means for solving problems]

The present invention has been made to solve the above problem, and according to the present invention, there is a joint body having a hole into which a pipe to be connected is inserted, and a joint body that is screwed to the end of the joint body. A fastening member having a threaded portion and an inclined inner circumferential wall, a locking ring in contact with the inner circumferential wall, and a biting member cooperating with the locking ring, and by screwing the fastening member to the joint body, the In the joint for buried pipes, the pipe and the joint are connected by compressing a packing disposed on the outer periphery of the pipe and attaching the biting member to the outer periphery of the pipe via the lock ring, wherein the lock ring consists of an annular portion in which a plurality of through holes are provided in the peripheral wall, and a bent portion that is bent radially outward from one end of the annular portion to form a substantially V-shape, and the biting member is configured such that a portion of the biting member protrudes from the through hole of the annular portion to the inner side of the annular portion and is held between the annular portion and the bent portion.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a partially cutaway sectional view showing a state in which the pipe joint according to the present invention is fastened to the end of a buried pipe;
FIG. 2 is a front view of an assembly of a locking ring and a ball as a biting member used in this embodiment.
FIG. 3 is a sectional view taken along the - line in FIG. 2.

As shown in FIGS. 2 and 3, the lock ring 3 in this embodiment has a ring part 11 and a ring part 1.
1 and are separated from each other by a notch 12, and further radially outward to form a substantially V shape.
It is made up of a plurality of bent parts 13 that are bent to form a letter shape. A plurality of through holes 14 are provided in the annular portion 11 . The through holes 14 and the bent portions 13 are arranged so as to correspond to each other in the circumferential direction of the ring. In addition, each through hole has
A ball 4 having a diameter larger than the diameter of this through hole is fitted from the outside of the annular portion, and is set so that a portion thereof protrudes inside the annular portion 11.
Since the head portion of the ball 4 on the outside of the annular portion 11 is held down by each bent portion 13, the ball 4 will not come off the lock ring 3. The ball 4 acts as a biting member. still,
When the ball 4 and the lock ring 3 are integrated, the bent portion 13 does not need to be in contact with the head of the ball, and there may be sufficient clearance to prevent the ball 4 from coming off.

FIG. 1 is a sectional view showing a state in which pipes are connected by a pipe joint using an assembly of a lock ring and a ball as a biting member as described above. Fastening member 1, O-ring 2, washer 5, in FIG.
The packing 6, the joint body 7, and the pipe 8 are basically the same as the corresponding parts of the conventional example described above, although there are some differences in shape. And fastener 1, O to pipe 8
- ring 2, ball and lock ring assembly;
The connection is completed by inserting the washer 5, packing 6, and joint body 7, and fastening the joint body 7 and the fastener using their respective threads. In this state, the packing 6 is compressed on the outer periphery of the tube 8, keeping the inside of the tube 8 liquid-tight from the outside. At this time, the ball 4 as a biting member is pressed by the bent part 13 of the lock ring 3 that comes into contact with the inner inclined wall of the fastener 1, and bites into the circumferential groove 8b of the tube with a certain holding force. It will be attached.

The lock ring 3 in this embodiment has an axial split 15 in a part of the annular portion 11. Therefore, the lock ring and the ball can be easily formed by producing a blank in the developed shape of the lock ring by punching or the like from a flat plate, bending the bent portion 13 with the balls 4 set in the through holes 14, and then rolling it into an annular shape. You can build an assembly with. Of course, it is also easy to set the ball by pushing out the bent portion of the lock ring after completing the lock ring. Further, since the ball rotates, tightening with the fastener can be easily performed, and there are advantages such as no excessive force is applied to the lock ring.

FIG. 4 is a plan view of the biting member 44 used in the second embodiment of the present invention. This biting member 44 forms a plurality of serrated protrusions 46 along the inner circumference of the ring,
The ring is shaped like a slit of a certain width cut into two halves, top and bottom. A sectional view of the assembly of the biting member 44 and lock ring 43 is shown in FIG. The lock ring 43 may have the same shape as the lock ring 3 of the first embodiment. A serrated projection 48 projects into the annular portion of the lock ring 43 from a through hole 47 of the lock ring 43, and the outer peripheral portion of the biting member 44 is restricted by a bent portion 49 of the lock ring to prevent it from coming off. Since the biting member in this embodiment can be manufactured by a simple press punching operation, a very inexpensive joint can be provided.

[Effect of idea]

As mentioned above, in the joint for buried pipes according to the present invention, the lock ring and the biting member are integrally assembled, so when the joint is used to connect buried pipes, Since the number of parts to be handled is smaller than that of the conventional example, handling becomes easier, work time can be shortened, and errors in assembly work can be reduced. Further, the bending portion of the lock ring need only be bent with an accuracy within a range that the biting member does not come off, so precise dimensional accuracy is not required, and manufacturing costs can be reduced.

Further, in the present invention, the biting member does not directly contact the inner circumferential wall of the fastening member, but is pressed by the inner circumferential wall through the bent portion of the lock ring that makes surface contact with the inner circumferential wall. Therefore, even if the fastening members are made of inexpensive copper alloys, etc., which have been widely used in these materials, the inner peripheral wall surface of the fastening member is depressed by the fastening member during fastening, and the amount of fastening to the pipe is reduced. There is no possibility that the connecting force with the pipe will decrease. Furthermore, even if an excessive force is applied from the outside, causing the pipe to come off and the locking ring to be forcibly moved in the axial direction relative to the fastening member, the inner circumferential surface of the fastening member will hardly be damaged and can be used again. obtain.

Furthermore, the annular portion of the lock ring of the present invention is partially cut off. That is, instead of using a cylindrical material to begin with, it can be manufactured at low cost by using a flat plate material and using relatively simple operations such as pressing.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the first embodiment of the present invention, Fig. 2 is a plan view of an assembly of a lock ring and a biting member used in the first embodiment, and Fig. 3 is a - of Fig. 2. A cross-sectional view along the line, FIG. 4 is the second part of the present invention.
A plan view of the biting member used in the example, FIG.
6 and 7 are half-sectional side views showing the state of the conventional buried pipe joint before and after assembly. 1... Fastening member, 3, 43... Lock ring,
4, 44... Biting member, 5... Washer, 6...
Packing, 7... Fitting body, 8... Buried pipe.

Claims (1)

[Scope of utility model registration request] A fastener comprising a joint body having a hole into which a pipe to be connected is inserted, a threaded part threaded onto an end of the joint body, and an inner circumferential wall whose diameter gradually increases toward the threaded part. a lock ring that contacts the inner peripheral wall, and a biting member that cooperates with the lock ring, and compresses the packing disposed on the outer periphery of the pipe by screwing the fastening member to the joint body. In addition, in the buried pipe joint that connects the pipe and the joint by biting the biting member to the outer periphery of the pipe via the locking ring, the locking ring has a plurality of through holes spaced apart in the circumferential direction. An annular part is provided and separated at one point in the circumferential direction, and a substantially V-shape is formed radially outward from one end of the annular part at a position corresponding to the position of the through hole in the circumferential direction. The biting member is formed of a plurality of bent parts bent as shown in FIG. When the fastening member is screwed onto the joint body while being held between the bent portions, the inclined inner peripheral wall of the fastening member comes into contact with the bent portions of the lock ring, thereby gradually reducing the diameter of the lock ring; A joint for a buried pipe, characterized in that the biting member is pressed and bitten onto the outer periphery of the pipe via the bent portion.