JPH0160714B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pipe joint for connecting pipes such as flexible hoses and pipes. The invention can be used, for example, in pipe fittings made from plastic or aluminum.

[Prior Art] A pipe joint generally has a first pipe connected to one pipe.
It consists of a pipe connecting member and a second pipe connecting member connected to the other pipe. The male threaded portion of the first pipe connecting member and the female threaded portion of the second pipe connecting member are screwed together and tightened to connect one pipe to the other pipe.

In such a pipe joint configured to tighten the male threaded portion of the first pipe connecting member and the female threaded portion of the second pipe connecting member, there is a risk that the screws may loosen depending on the place of use.

Therefore, in order to prevent screws from loosening,
A pipe joint configured to fasten the first pipe connecting member and the second pipe connecting member with a tangled wire, a pipe joint configured to fasten the first pipe connecting member and the second pipe connecting member with screws, and a pipe joint configured to fasten the first pipe connecting member and the second pipe connecting member with screws. A pipe joint is provided in which an adhesive is interposed between a male threaded portion and a female threaded portion of a second pipe connection member.

However, in the pipe joint having the above-mentioned structure, the effect of preventing screw loosening is not necessarily sufficient.

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems, and its purpose is to improve the connection between the male threaded portion of the first pipe connecting member and the female threaded portion of the second pipe connecting member. To provide a pipe joint that can effectively prevent loosening between parts. Another object of the present invention is to provide a pipe joint that is advantageous in preventing over-tightening or under-tightening of the male threaded portion and the female threaded portion in the case of an embodiment in which an elastic sealing member is provided.

[Means for Solving the Problems] The pipe joint according to the present invention has one end connected to one pipe, has a central through hole communicating with the hole of the one pipe, and has a central through hole in the outer periphery of the other end. a first pipe connecting member having a male thread; one end connected to the other pipe; a central through hole communicating with the hole of the other pipe; In a pipe joint configured with a second pipe connecting member having a female threaded portion to be screwed together, the first pipe connecting member has an annular shape that coaxially covers the first pipe connecting member and is prevented from rotating in the circumferential direction. a locking member movable in the axial direction; urging the locking member toward the other end of the first pipe connecting member in the axial direction; and the female threaded portion is screwed into the male threaded portion. an urging member that presses the locking member into contact with the second pipe connection member, and the contact surface between the locking member and the second pipe connection member that are pressed into contact with each other is The second pipe connecting member is a one-way locking surface that is rotatable in the screw tightening direction and unrotatable in the screw unscrewing direction.

The pipe joint according to the present invention includes a first pipe connecting member having a threaded portion on the outer periphery, and a second pipe connecting member having a female threaded portion on the inner periphery. Here, the names, pitches, etc. of the female threaded portion and male threaded portion may be the same as those of conventional pipe joints. Both the first tube connecting member and the second tube connecting member have a cylindrical shape, and thus have a central through hole. The diameter, shape, etc. of the central through hole can be the same as those of conventional pipe joints.

A locking member and a biasing member are attached to the first pipe connecting member. The locking member has an annular shape,
This is a member that coaxially covers the first pipe connecting member. The locking member is prevented from rotating in the circumferential direction while being attached to the first pipe connecting member, and is movable in the axial direction. In such a configuration, a key and a keyway can be used. For example, a key groove extending in the axial direction may be formed on the outer circumference of the first pipe connecting member, a key may be formed on the inner circumference of the locking member, and the key and the key groove may be fitted together. Can be done.

The biasing member is a member that has a resilient force and biases the locking member in the axial direction toward the other end side of the first tube connecting member. Here, the other end side of the first tube connecting member means a portion opposite to one end of the first tube connecting member, which is a portion to which one tube is connected. Typical biasing members include coil springs,
A spring member such as a leaf spring or a highly elastic rubber member can be used.

Now, in the pipe joint according to the present invention, the locking member and the second
The abutting surface with the pipe connecting member is a one-way locking surface that allows the second pipe connecting member to rotate in the screw tightening direction and that does not allow the second pipe connecting member to rotate in the screw unscrewing direction. .

A typical one-way locking surface can be formed by a claw portion formed by an inclined surface and a vertical surface. In this case, the locking member and the second pipe connecting member are each formed with claw portions that correspond to each other.
When the claws are formed in this way, when the inclined surfaces of the claws come into contact with each other, the locking member moves in the axial direction while resisting the biasing force of the biasing member due to the so-called "wedge principle". Therefore, the second pipe connecting member can be rotated in the screw tightening direction. Further, when the vertical surfaces of the claws come into contact with each other, they are locked with each other, so that the second pipe connecting member cannot be rotated.Therefore, the second pipe connecting member cannot be rotated in the unscrewing direction. Note that there is a space between the first pipe connecting member and the second pipe connecting member when the male threaded portion and the female threaded portion are tightened. It is preferable to provide an elastic sealing member that provides a seal without being removed. This elastic sealing member can be attached to the first tube connecting member.

[Function] A method of using the pipe joint according to the present invention will be explained. First, the first tube connecting member and the second tube connecting member are held with fingers or a spanner, and the male threaded portion of the first tube connecting member and the female threaded portion of the second tube connecting member are screwed together. As the screwing progresses in this manner, the locking member comes into contact with the second pipe connecting member. At this time, the locking member is pressed against the second pipe connecting member by the elastic force of the urging member. Here, since the contact surface between the locking member and the second pipe connection member is a one-way locking surface as described above, the second pipe connection member can be rotated in the screw tightening direction. , the second pipe connecting member cannot be rotated in the unscrewing direction.

Further, when the elastic seal member is provided, there is no space between the first pipe connecting member and the second pipe connecting member when the male threaded portion and the female threaded portion are screwed together and tightened. In other words, the first pipe connecting member and the second pipe connecting member collide through the elastic sealing member. When such a collision occurs, the resistance during screwing increases rapidly, allowing the operator to know that the tightening is almost complete. When the tightening is almost completed in this way, the elastic sealing member is elastically deformed by screwing it further by a predetermined amount, and the first pipe connecting member and the second pipe connecting member are screwed together.
Sealing performance between the pipe connecting member and the pipe connecting member can be ensured.

[Effects of the Invention] As described above, in the pipe joint according to the present invention, the contact surface between the locking member and the second pipe connecting member is such that the second pipe connecting member can rotate in the screw tightening direction. The second pipe connecting member is configured as a one-way locking surface that cannot be rotated in the direction of unscrewing. Therefore, even if the pipe joint is used in a place where vibrations, shocks, etc. are applied, loosening of screws can be suppressed compared to conventional pipe joints.

In addition, when an elastic seal member is provided, as mentioned above, the operator can know that the tightening of the male thread part and the female thread part is almost completed, and therefore the operator can screw the male thread part and the female thread part further together by a predetermined amount. That's fine. This is advantageous in preventing over-tightening or under-tightening.

[Example] One embodiment of the present invention is shown in FIGS. 1-10.

(Structure of Example) The pipe joint according to this example is composed of a first pipe connecting member 1 and a second pipe connecting member 2. The first pipe connecting member 1 has a nipple shape with a central through hole 12 and a nut portion 14 for fluid passage. A tapered thread 10 is formed on the outer periphery of one end 1a of the first pipe connecting member 1. As shown in FIG. Although not shown, one pipe is screwed and connected to the tapered screw 10. As shown in FIG. 2, the first pipe connecting member 1
A male threaded portion 13, which is a parallel pipe thread, is formed on the outer periphery of the other end 1b. Further, on the outer periphery of the other end 1b side of the first pipe connecting member 1, there are
As shown in the figure, the keyway 15 extends parallel to the axial direction.
Individually formed.

A locking member 3 and a coil spring 4 as a biasing member are attached to the first pipe connecting member 1. The locking member 3 has an annular shape as shown in FIGS. 4 and 5. Side surface 33 of this locking member 3
Eight pawls 30 are formed in series in the circumferential direction at equal intervals, that is, at intervals of 45 degrees. This claw part 30
is a vertical surface 31 substantially parallel to the axial direction of the locking member 3
and an inclined surface 32 whose axial dimension gradually decreases from the tip of the vertical surface 31. Further, two keys 34 are formed on the inner peripheral portion of the locking member 3 so as to face each other. By fitting the key 34 and the keyway 15 into each other, the locking member 3 is attached to the first pipe connecting member 1 in a rotationally prevented manner. Here, if the key 34 is moved along the key groove 15, the locking member 3 can be moved along the axial direction of the first pipe connecting member 1 while remaining in the non-rotating state. The locking member 3 is prevented from coming off the first pipe connecting member 1, and this is done by means of a pin fixed to the locking member 3.

A coil spring 4 as a biasing member is interposed between the nut portion 14 of the first tube connecting member 1 and the locking member 3. The coil spring 4 uses its elastic force to warp the locking member 3 in the axial direction and connect it to the first pipe connecting member 1.
The other end 1b is biased toward the other end 1b. Note that FIG. 6 shows a state in which the locking member 3 is biased toward the other end 1b by the coil spring 4. On the other hand, FIG. 7 shows a state in which the locking member 3 is moved toward the nut portion 14 against the coil spring 4.

As shown in FIGS. 1 and 8, the second pipe connecting member 2 includes a union nut portion 20 having a central through hole 20a, and a cylindrical body 21 inserted into the union nut portion 20 and having a central through hole 21a. Become. As shown in FIG. 1, the protrusion 210 of the cylinder 21 comes into contact with the protrusion 200 of the union nut part 20, so that the cylinder 21 is prevented from coming off from the union nut part 20. The socket 50 of the other tube 5 is caulked into the groove 21b at one end of the cylindrical body 21, and as a result, the other tube 5 is connected to the second tube connecting member 2. A female threaded portion 23 is formed on the inner peripheral portion of the union nut portion 20 of the second pipe connecting member 2 . This female threaded portion 23 is connected to the first pipe connecting member 1.
It is screwed together with the male threaded portion 13 of. Further, the union nut portion 20 has a claw portion 2 as shown in FIGS. 9 and 10.
Eight pieces 2 are formed at equal intervals in the circumferential direction, that is, at intervals of 45 degrees. This claw portion 22 corresponds to the claw portion 30 of the locking member 3, and is formed of a vertical surface 220 parallel to the axial direction and an inclined surface 221.

In this embodiment, the one-way locking surfaces include the vertical surface 31 and the inclined surface 32 of the claw portion 30 of the locking member 3, the vertical surface 220 of the claw portion 22 of the union nut portion 20, and the inclined surface 2.
21.

In FIG. 1, 6 is an elastic sealing member;
It is attached to the recess 16 on the other end 1b side of the first pipe connecting member 1. As a result, the elastic seal member 6 can come into contact with the end surface 21c of the cylindrical body. This elastic seal member 6 has an O-ring shape,
Made from vulcanized rubber.

(Operation of the embodiment) A typical usage method of the pipe joint according to the present embodiment will be explained. First, with fingers, a spanner, or the like, the male threaded portion 13 of the first tube connecting member 1 and the female threaded portion 23 of the second tube connecting member 2 are turned in the tightening direction to screw them together. Then, the inclined surface 32 of the claw portion 30 of the locking member 3
and the inclined surface 221 of the claw portion 22 of the second pipe connecting member 2 come into contact with each other. After the inclined surfaces 32 and 221 contact each other in this way, if the screwing is continued in the tightening direction, the locking member 3 will be pressed against the inclined surfaces 221 by the so-called "wedge principle" and the coil spring will spring up. It moves in the direction of arrow A shown in FIG. 7 while resisting the elastic force of 4. Therefore, the screwing between the second pipe connecting member 2 and the first pipe connecting member 1 progresses. As the screwing progresses in this manner, the end surface 21c of the cylindrical body 21 and the elastic seal member 6 come into contact with each other. When the end surface 21c of the cylindrical body 21 and the elastic seal member 6 come into contact with each other, the resistance when turning in the screw tightening direction increases rapidly. After the resistance suddenly increases in this way, turn the union nut part 20 in the screw tightening direction so that the claw part 30 advances a predetermined pitch, for example, 4 to 6 pitches, and then tighten the first pipe connecting member 1. The connection with the second pipe connecting member 2 is completed.

In this completed state, the elastic seal member 6 is pressed by the end surface 21c of the cylinder 21 and is appropriately elastically deformed, so that the union nut portion 20 of the second pipe connection member 2 and the first pipe connection member 1 Good sealing performance between the two can be ensured.

Incidentally, even when the pipe joint according to the above embodiment is used in a place where screws are likely to loosen due to vibrations or shocks, the locking member 3 biased by the elastic force of the coil spring 4 is engaged with the claw portion 22 of the union nut portion 20 of the second pipe connecting member 2, so that the screw does not loosen. That is, when the first pipe connecting member 1 or the second pipe connecting member 2 tries to turn in the direction in which the screws loosen, the vertical surface 31 of the claw portion 30 of the locking member 3
and the vertical surface 220 of the claw portion 22 of the union nut portion 20 of the second pipe connecting member 2 are engaged with each other.
The second pipe connecting member 2 cannot be rotated in the direction of loosening the screw.

On the other hand, when removing the first pipe connecting member 1 and the second pipe connecting member 2, the locking member 3 is moved toward the nut portion 14 while resisting the coil spring 4, that is, in the direction of arrow A shown in FIG. This releases the lock between the claw portion 30 of the locking member 3 and the claw portion 22 of the union nut portion 20 of the second pipe connecting member 2. In this state, turn at least one of the first pipe connecting member 1 and the second pipe connecting member 2 in the unscrewing direction, and
Male thread part 13 of pipe connecting member 1 and second pipe connecting member 2
The threaded connection with the female threaded portion 23 is released, thereby separating the first pipe connecting member 1 and the second pipe connecting member 2.

(Effects of Example) As described above, in this example, loosening of the male threaded portion 13 of the first pipe connecting member 1 and the female threaded portion 23 of the second pipe connecting member 2 can be effectively suppressed. Can be done.

Further, in this embodiment, after the screwing resistance in the screw tightening direction increases rapidly, if the claw portion 30 is turned in the screw tightening direction so as to advance by a predetermined pitch, the male thread portion 13 and the female thread portion 23 can be separated. The tightening strength of is always a nearly constant value. Therefore, both under-tightening and over-tightening can be effectively prevented. Therefore, it is possible to effectively prevent fluid leakage due to insufficient tightening and damage to the pipe joint due to excessive tightening. Therefore, it is suitable for pipe fittings made of plastic or aluminum, which are prone to breakage if over-tightened.

Furthermore, in this embodiment, by appropriately selecting the predetermined number of pitches described above, the tightening strength can be finely adjusted in stages.

(Test Example) In the pipe joint according to the above example, the claw portion 3
The degree to which 0 influences the increase in tightening torque was tested.

In this test, the first tube connecting member 1 and the second tube connecting member 2 were formed from glass fiber-containing resin. The thread sizes of the male threaded portion 13 and female threaded portion 23 were PF1/2 (JISBO202). In this case, the union nut breaking torque when the union nut part 20 is damaged is 500 kg-cm, and after turning the union nut part 20 in the tightening direction and suddenly feeling resistance, turn the union nut part 20 by a predetermined amount to tighten the claw part 30 to a predetermined position. I made a lot of progress and did it. The test results are shown in FIG. In FIG. 11, the horizontal axis indicates the number of pitches of the claw portion 30, and the vertical axis indicates the obtained tightening torque. As shown in Fig. 11, after suddenly feeling resistance, push the claw part 30 4 to 6 pitches (union nut part 2
When proceeding at a rotation speed of 0.5 to 0.75 rotations), the tightening torque was 100 to 150 kg-cm, and an appropriate tightening torque value (tightening torque that provides a pressure resistance of 280 kg/cm ² ) was obtained. From this result, it was found that one pitch of the claw portion 30 after the resistance suddenly increased was 25 kg-cm.

[Brief explanation of drawings]

1 to 10 show one embodiment of the present invention,
FIG. 1 is a partially cutaway side view of the pipe joint of this embodiment, FIG. 2 is a plan view of the main part of the first pipe connection member, and FIG. FIG. 4 is a side view of the locking member with its upper half cut away, FIG. 5 is a front view of the locking member, and FIG. 6 is a cross-sectional view of the pipe connecting member. FIG. 7 is a side view of the first pipe connecting member with the locking member and the urging member attached; FIG. 7 is a side view of the first pipe connecting member with the locking member moved against the urging member; Figure 8 is the second
FIG. 9 is a side view of the pipe connecting member; FIG. 9 is a front view of the union nut portion of the second pipe connecting member;
The figure is a side view of the union nut section with the upper half cut away. FIG. 11 is a graph showing the relationship between tightening torque and the number of pitches of the claw portion. In the figure, 1 is the first pipe connecting member, 1a is one end, 1b
is the other end, 10 is a tapered screw, 12 is a central through hole,
13 is a male thread part, 15 is a keyway, 2 is a second pipe connecting member, 20 is a union nut part, 20a is a central through hole, 21 is a cylinder body, 21a is a central through hole, 23 is a female thread part, 22 is a claw part , 220 is a vertical plane, 221
3 is an inclined surface, 3 is a locking member, 30 is a claw portion, 31 is a vertical surface, 32 is an inclined surface, 34 is a key, 4 is a coil spring (biasing member), 5 is the other tube, 50 is a socket,
Reference numeral 6 indicates an elastic seal member.

Claims (1)

[Claims] 1. A first pipe connecting member having one end connected to one pipe, having a central through hole communicating with the hole of the one pipe, and having a threaded portion on the outer periphery of the other end. , a second pipe having one end connected to the other pipe, having a central through hole communicating with the hole of the other pipe, and having a female threaded part screwed with the male threaded part on the inner peripheral part of the other end side.
and a pipe connecting member, the first pipe connecting member comprising: a locking member that coaxially covers the first pipe connecting member and is prevented from rotating in the circumferential direction and is movable in the axial direction; , biasing the locking member along the axial direction toward the other end of the first pipe connecting member, and applying force to the second pipe connecting member whose female threaded portion is screwed into the male threaded portion; and a biasing member that presses the locking member into contact with the locking member, and the contact surface between the locking member and the second pipe connection member that is pressed and abutted against the second pipe connection member in the screw tightening direction. A pipe joint characterized in that the member is rotatable and the second pipe connecting member is a one-way locking surface that cannot be rotated in the unscrewing direction. 2. The locking member has a claw portion formed by at least two vertical surfaces that are arranged in series in the circumferential direction and are substantially parallel to the axial direction, and an inclined surface whose axial dimension gradually decreases from the tip of the vertical surfaces. The second pipe connecting member has a claw portion that corresponds to the claw portion of the locking member, and the one-way locking surface is composed of both of the claw portions, and a male threaded portion and a female threaded portion. When turning the screws in the screw tightening direction, the inclined surfaces of both claws face each other, and when turning the screws in the unscrewing direction, the vertical surfaces of both claws come into contact with each other and lock. A pipe joint according to claim 1, wherein the pipe joint is configured as follows. 3. Between the first pipe connecting member and the second pipe connecting member, there is a space between the first pipe connecting member and the second pipe connecting member when the male threaded part and the female threaded part are tightened. 2. The pipe joint according to claim 1, further comprising an elastic sealing member that seals without being removed. 4 The first pipe connecting member has a keyway on the outer circumference, the locking member has a key on the inner circumference, and the locking member is connected to the first pipe by fitting the key and the keyway. The pipe joint according to claim 1, which is configured to prevent rotation relative to the member. 5. The pipe joint according to claim 1, wherein the first pipe connecting member has a nipple shape, and the second pipe connecting member has a union nut shape.