JPH06265071A - Coupling for bellows pipe - Google Patents

Abstract

PURPOSE:To provide a coupling which is constituted to prevent the drop of an engaging member before a connection work for a bellows pipe, perform simple and reliable connection of the bellows pipe, prevent the occurrence of slip-off thereof, and have excellent sealing ability. CONSTITUTION:An approximate annular engaging member 50 is mounted in an resiliently expanded state on the outer periphery of the receipt part 33 of a support member 30 contained in a body 20. The engaging member 50 is contained in the first containing recessed part 28 of the body 20. When the support member 30 is pressed by a bellows pipe 10 against the force of a coil spring 40, the engaging member 50 is disengaged from the support member 30 and fitted in the root part 10b of the bellows pipe 10. Through locking operation of the engaging member 50 to the lock part 29 of the body, the bellows pipe 10 is prevented from slip-off. Further, a seal member 60 on the outer periphery of which a plurality of annular protrusions 61 are formed is contained in the second containing space 24a of the body 20. A relation of nD not equal to mP (n and m are an integral number) is established between a distance D between the protrusions 61 and the pitch P of the crest part 10a of the bellows pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for easily connecting a bellows tube used for supplying gas at home.

[0002]

2. Description of the Related Art Japanese Utility Model Laid-Open No. 3-52493 discloses a joint which can be easily connected by inserting a bellows tube. In detail, the body of this joint has a through hole provided at one end as an inlet. In the through hole, first and second accommodating recesses having an annular shape are formed axially away from the inlet. The first accommodating recess accommodates an annular engagement member that connects both ends of the coil spring, and the second accommodating recess accommodates an annular seal member. Of the two side surfaces that define the first accommodation recess, the side surface closer to the inlet is tapered, and the other side surface is orthogonal to the axis. The engaging member and the seal member are attached to the body in advance before connecting the bellows tube. When the tip portion of the bellows tube is inserted from one end of the through hole, every time the crest portion of the bellows tube passes through the engaging member, all the winding portions of the engaging member are deformed from a circular shape to an elliptical shape, and a valley portion is formed. All winding members return to their original circular shape each time they pass through the engaging members. While repeating this several times, the bellows tube further advances to insert the tip of the bellows tube into the seal member. The tip of the bellows tube hits a step formed on the body and is prevented from further entering. In this way, the bellows tube is connected to the joint, and in the connected state, the seal member is brought into close contact with the outer periphery of the bellows tube in an elastically deformed state, thereby sealing the bellows tube and the body. When a pulling force is applied to the bellows tube, radial and outward forces are applied to the engaging member from the inclined surface of the bellows tube, but radial and inward forces from the tapered surface of the first accommodating recess, that is, bellows. Since the force for pushing back to the valley portion of the pipe is applied, the engaging member is prevented from overcoming the crest portion of the bellows pipe while deforming into the elliptical diameter.

Even the joints disclosed in FIGS. 3 and 4 or the joints disclosed in FIGS. 5 and 6 of Japanese Utility Model Publication No. 3-91592 can be easily connected by inserting a bellows tube. More specifically, in this joint, the through hole of the body has an annular accommodation recess whose inner peripheral surface is tapered, and the accommodation recess is provided with a seal member and an annular engagement member whose outer peripheral surface is tapered. Is installed in advance. The engaging member is
It is formed in an annular shape by connecting both ends of the coil spring, and is fixed to the end of the seal member when the seal member is molded. The seal member is biased toward the entrance of the through hole by another coil spring. In the joint having such a structure, when the bellows tube is inserted into the through hole of the body, the leading edge of the bellows tube hits the engaging member, and the engaging member and the sealing member are moved toward the back of the housing recess. . When the seal member hits the inner end of the accommodating recess and the movement of the seal member is restricted, the bellows tube is inserted further into the seal member after passing through the engaging member. The engaging member elastically expands in diameter each time the crest portion of the bellows tube passes, and then reduces in diameter after the peak portion passes and fits into the trough portion. After that, when the worker releases the bellows tube, the force of the coil spring moves the seal member, the engagement member and the bellows tube in the direction opposite to the insertion direction, and the taper outer peripheral surface of the seal member is tapered by the accommodation recess. It contacts the inner peripheral surface of the body, which seals the body and the bellows tube. In addition, the engaging member hits a tapered locking surface formed at the entrance of the through hole in a state where the engaging member is fitted in the valley portion of the bellows tube,
The bellows tube is prevented from coming off.

[0004]

However, the above-mentioned actual Kaihei 3
The joint of No. 52493 had the following disadvantages. That is, since the engaging member is simply accommodated in the first accommodating recess, a relatively small impact is applied to the joint while the joint having the engaging member mounted on the body is transported to the construction site at the factory. Occasionally, the engagement member will fall out of the joint.
Further, when the bellows tube is inserted, the engaging member rides over the peak portion of the bellows tube due to the elastic deformation of each winding portion, so that the engaging member receives a force from the inner peripheral surface of the first accommodating recess toward the trough. The insertion resistance was large. Also, the actual Kaihei 3-91
In the joint of Japanese Patent No. 592, although the insertion resistance varies each time the engaging member crosses the crest portion of the bellows tube a plurality of times, the operator can clearly confirm the end of the connecting work of the bellows tube to the joint. There wasn't. An object of the present invention is to prevent the engaging member from falling off the body before the work of connecting the bellows tube, to easily connect the bellows tube, and to clearly recognize the connection of the bellows tube to the operator. It is an object of the present invention to provide a joint in which the connection can be ensured and the seal between the bellows tube and the joint can be surely performed.

[0005]

The gist of the invention of claim 1 is a joint for a bellows pipe having alternating peaks and valleys, which has (a) a through hole. One end of which is provided as an inlet for inserting the bellows tube, and an inner periphery of the through hole has an annular first accommodating recess formed in order toward the inlet, an annular engaging portion, and an annular engaging portion. A body in which a second accommodation recess is formed; (b) a support member that is accommodated in the body and has a tubular shape, and the end portion on the inlet side is provided as a receiving portion; and (c) the support member. To the inlet, and a coil spring for arranging the receiving portion of the supporting member at a position facing the inner peripheral surface of the first accommodating recess, and (d) forming a substantially annular shape of the receiving portion of the supporting member. A bellows tube that is attached to the outer periphery in an elastically expanded state and is inserted from the inlet. When the tip portion pushes the support member in the direction away from the inlet against the spring, it deviates from the inlet side end of the receiving portion of the support member and contracts in diameter to fit into the outer periphery of the valley of the bellows tube. An engaging member that prevents the bellows tube from coming off by locking a part of the bellows tube projecting from the outer periphery of the crest in the fitted state of the bellows tube with a locking part of the body,
(E) A plurality of annular protrusions, which are accommodated in the second accommodating concave portion, have an inner diameter smaller than the outer diameter of the mountain portion of the bellows tube, and have a plurality of annular protrusions axially separated from each other on the outer periphery. A bellows pipe joint, comprising: an annular seal member that is in contact with the inner peripheral surface. The gist of the invention of claim 2 is that the distance between the protrusions of the seal member is D, the pitch of the crests of the bellows tube is P, and n is equal to or less than the number of the protrusions minus one. When n is a small integer and m is an integer equal to or smaller than the maximum value of the number of peaks located in the seal member when the bellows pipe passes through the seal member or smaller than this, nD ≠ mP It is related to a joint for a bellows pipe.

[0006]

According to the present invention, since the engaging member is housed in the housing recess of the body and is mounted on the outer periphery of the receiving portion of the support member, it is possible to reliably prevent the engaging member from falling off the body. it can. When the bellows tube is inserted into the joint, its tip pushes the support member against the spring. On this occasion,
Since the engagement member is prohibited from moving by the side surface of the accommodating recess, when the bellows tube is inserted into the joint by a predetermined amount, the engagement member separates from the receiving section, and its elastic force reduces the diameter of the bellows tube. Fit in the valley. The impact sound and the vibration at that time allow the operator to clearly recognize that the engagement between the engaging member and the bellows tube is completed and the connection between the bellows tube and the joint is completed. The engaging member fitted in the valley portion of the bellows tube is locked to the locking portion of the body to prevent the bellows tube from coming off the joint. Moreover, since the inner periphery of the seal member elastically deforms contacts the bellows tube, and the projection on the outer periphery thereof strongly abuts the inner peripheral surface of the second accommodating recess, ensuring the seal between the joint and the bellows tube. Can be done. According to the invention of claim 2, in the process of connecting the bellows tube, it is possible to prevent a plurality of peaks of the bellows tube from simultaneously passing through a plurality of protrusions of the seal member, so that the insertion resistance caused by the seal member is sharp. The rise and the sudden drop do not occur, and the insertion resistance due to only this seal member changes comparatively gently. Therefore, when the bellows tube is further inserted deeply and the insertion resistance caused by the spring is received, the operator can clearly recognize the increase of the insertion resistance and that the tip of the bellows tube has reached the slider. Therefore, the bellows tube can be connected more reliably.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A joint A according to an embodiment of the present invention will be described below with reference to the drawings. First, the bellows tube 10 (FIG. 2) as a gas tube connected to the joint A will be described. The bellows tube 10 is made of metal, has alternating peaks 10a and valleys 10b, is thin, and can be easily bent by human power.

As shown in FIGS. 1 and 2, the joint A includes a body 20 and a slider 30 (supporting member), a coil spring 40, an engaging member 50, and a sealing member 60 which are housed in the body 20, respectively. I have it.

The body 20 is composed of two metal cylinders 2.
It is configured by connecting 1 and 23. One cylinder 21 has a through hole 22 extending in the axial direction. The diameter of the through hole 22 gradually increases toward the right in the figure. More specifically, the through holes 22 have four different diameters.
It has two inner peripheral surfaces. These inner peripheral surfaces are numbered 22a, 22b, 22c and 22d in order from the left. An annular convex portion 22e is formed in the middle portion of the innermost surface 22a on the leftmost side. The side surface of the convex portion 22e on the inlet 24x side is provided as a spring receiving step 22e 'for the coil spring 40 as described later. Further, the step formed at the boundary between the inner peripheral surfaces 22a and 22b, and the inner peripheral surface 22
The steps formed on the borders of b and 22c are respectively denoted by reference numeral 22.
f and 22g are attached. Screws 21x on the inner peripheral surface 22c
Are formed. A taper screw 21y for connecting to a gas appliance is formed on the outer peripheral surface of the left end of the cylinder 21.

The other cylinder 23 has a through hole 2 extending in the axial direction.
Have four. The right end 24x of the through hole 24 is provided as an inlet for inserting the bellows tube 10. A screw 23x is formed on the outer periphery of the left end of the cylinder 23.

The above-mentioned pair of cylinders 21 and 23 are coaxially connected by screwing together screws 21x and 23x, and the through holes 22 and 24 are provided as the through holes of the body 20. . In this connected state, the cylinder 2
Between the inner peripheral surface 22d of 1 and the outer peripheral surface of the cylinder 23, a seal member 27 for sealing between the two is disposed. Tube 2
1 inner peripheral surface 22c, step 22g, and tip surface 23a of the cylinder 23
The annular receiving recess 28 for the engaging member 50
A (first housing recess) is formed. In addition, an annular locking surface 29 that is tapered adjacent to the front end surface 23a of the cylinder 23 is formed.
(Locking part) is formed. The inner diameter of the locking surface 29 gradually becomes smaller toward the inlet 24x.

The inner peripheral surface 22b of the cylinder 21 is provided as a guide portion for slidably guiding the metal slider 30. The slider 30 includes a cylindrical base portion 31 and an annular flange 3 formed on an inner circumference of an intermediate portion of the base portion 31.
2 and the axial direction from the base 31 to the right (inlet 24x direction)
The receiving portion 33 has a cylindrical shape that protrudes to the outside, and an annular protrusion 34 formed on the outer periphery of the right end portion of the receiving portion 33. Base 3
The outer diameter of 1 is 10 μm to 50 μm larger than the inner diameter of the guide portion 22b.
It is formed in a small size of about μm, and silicone oil or grease is interposed in the slight gap between them,
The frictional resistance between the two is reduced. The outer diameter of the receiving portion 33 is smaller than that of the base portion 31, and a step 35 is formed between them. The surface of the flange 32 opposite the inlet 24x is provided as a spring receiving step 32a for the coil spring 40. Base 31 of slider 30
On the inner periphery of the ring-shaped projection 3 that faces the step 32a at a distance.
8 is formed. Further, the slider 30 includes
An accommodation recess 36a is formed facing the inlet 24x, and an annular seal member 36 made of an elastic material is accommodated in the accommodation recess 36a.

The slider 30 is biased to the right (in the direction of the inlet 24x) by the coil spring 40 in a compressed state. The left end of the coil spring 40 is the step 2 of the cylinder 21.
2e ', and the right end is the step 32a of the slider 30.
Is hitting. Inlet 24 of this coil spring 40
Almost one turn portion on the x side has the protrusion 38 and the step 32.
It is supported by interposing with a.

The joint A includes an engaging member 50 having a substantially annular shape. The engagement member 50 is formed by bending a coil spring in a circular shape, and both ends thereof are not connected to each other and overlap each other in a natural state. In a state before the bellows tube 10 is inserted into the joint A, the engagement member 50 is mounted on the outer periphery of the receiving portion 33 of the slider 30 and is accommodated in the accommodation recess 28 of the body 20, as shown in FIG. 1. In this mounted state, the engagement member 50 is elastically expanded in diameter, and both ends thereof are separated. The slider 30 is pushed to the right by the force of the coil spring 40. However, since the engaging member 50 is interposed between the step 35 and the tip end surface 23a of the cylinder 23, the slider 30 moves to the right. Directional movement is restricted. In this state, the receiving portion 33 of the slider 30 has the receiving recess 2
8 is arranged so as to face the inner peripheral surface 22c of 8 and closes the accommodation recess 28. The diameter of one turn of the engaging member 50 is
The inner peripheral surface 22c of the accommodation recess 28 and the receiving portion 3 of the slider 30.
It is smaller than the gap with the outer peripheral surface of No. 3.

An accommodating recess 24a (second accommodating recess) is formed on the inner peripheral surface of the through hole 24 of the cylinder 23 and is separated from the inlet 24x by a predetermined distance. An annular seal member 60 made of soft rubber is housed in the housing recess 24a. The inner diameter of the seal member 60 is smaller than the outer diameter of the peak portion 10a of the bellows tube 10 and larger than the outer diameter of the valley portion 10b. On the outer periphery of the seal member 60, three annular protrusions 61 are formed at equal intervals.

The interval D (FIG. 2) between the protrusions 61 is different from the pitch P (FIG. 2) of the bellows tube 10. What is important is that, in the process of inserting the bellows tube 10, when one peak portion 10a is in a position corresponding to one protrusion 61, another peak portion 10a is in a position corresponding to any of the other protrusions 61. Is something that does not exist. In other words, the relationship between the distance D and the pitch P can be expressed by the following equation. nD ≠ mP However,
“N” is an integer equal to or smaller than the number of the protrusions 61 minus 1. “M” indicates the mountain portion 1 that comes into contact with the seal member 60 when the bellows tube 10 passes through the seal member 60.
It is an integer equal to or less than the maximum number of 0a minus 1. In this embodiment, “n” is 1 or 2 because there are three protrusions 61. Also, "m" is 1
Is. Therefore, in this embodiment, the distance D between the protrusions 61 is preferably 0.70 to 0.80 times the pitch P, and is actually 0.75 times.

In the joint A having the above structure, as shown in FIG. 1, the engaging member 50 is housed in the housing recess 28 of the body 20 and the slider 30 that closes the housing recess 28.
Since it is mounted on the outer periphery of the receiving portion 33 of the
Can be reliably prevented from falling off the body 20.

The joint A is attached to a gas appliance by previously screwing a taper screw 21y into a screw hole of a gas appliance such as a gas stopper, a header, or cheese. In this state,
The end of the bellows tube 10 is connected to the joint A. When the end portion of the bellows tube 10 is inserted from the inlet 24x of the joint A, the inclined surface of the topmost peak portion 10a contacts the seal member 36 of the slider 30. In this state, the right end of the receiving portion 33 of the slider 30 is
It is located at a position corresponding to the mountain portion 10 a of the bellows tube 10.

When the bellows tube 10 is further advanced, the slider 30 is moved leftward against the force of the coil spring 40. At this time, the receiving portion 33 of the slider 30 is inserted into the accommodation recess 2
8, but the engagement member 50 is not the step 22 of the body 20.
g, that is, the side surface of the accommodating recess 28 prevents movement to the left. As a result, the engaging member 50 is disengaged from the receiving portion 33, the diameter thereof is reduced by the elastic force, and the engaging member 50 is fitted into the valley portion 10b of the bellows tube 10. At the moment when the engaging member 50 is fitted into the valley portion 10b of the bellows tube 10, an impact sound is generated, and
The vibration associated with this shock is transmitted to the operator's hand through the bellows tube 10, so that the operator completes the engagement between the engagement member 50 and the bellows tube 10, and thus the connection between the bellows tube 10 and the joint A is completed. You can clearly recognize that it has been completed. Even when the engagement member 50 is fitted in the valley portion 10b of the bellows tube 10, both ends are apart from each other and the diameter thereof is elastically expanded. Touches.

When the engaging member 50 separates from the receiving portion 33, the engaging member 50 has to be further expanded in diameter in order to get over the protrusion 34. At this time, the insertion resistance of the bellows tube 10 temporarily increases. Then, the engaging member 50 becomes the projection 3
After overcoming 4 and fitting in the valley portion 10b of the bellows tube 10, the insertion resistance suddenly decreases. The operator can also clearly recognize that the engagement between the engaging member 50 and the bellows tube 10 is completed by the change in the insertion resistance.

By inserting the left end of the slider 30 into the step 22f of the body 20, the insertion depth of the bellows tube 10 is regulated. When the operator releases the bellows tube 10, as shown in FIG. 2, the slider 30 and the bellows tube 10 are returned to the right by the force of the coil spring 40, and the engaging member 50 is moved to the tubular portion 2.
It is locked to the locking surface 29 formed at the tip of the No. 3. Thus, by confirming that the bellows tube 10 is returned by the force of the coil spring 40, it is possible to confirm the completion of the connecting work of the bellows tube 10. Further, by locking the engaging member 50 to the locking surface 29, the bellows tube 10 can be prevented from coming off the joint A even when the bellows tube 10 is pulled to the right. When the bellows tube 10 is pulled to the right, the inclined portion of the bellows tube 10 applies a force to the engaging member 50 in the radial direction and the outward direction. Since the force in the direction is applied, it is possible to reliably prevent the diameter from being elastically expanded.

When the bellows tube 10 is connected to the joint A, since the seal member 60 is in elastically deformed contact with the peak portion 10a of the bellows tube 10, the body 20 and the bellows tube 1 are connected.
A seal with zero can be made. Moreover, since the protrusion 61 of the seal member 60 hits the inner peripheral surface of the accommodation recess 24a relatively strongly, the sealing performance can be further improved.

Further, by using the slider 30, the sealing property can be further enhanced. More specifically, the outer peripheral surface of the base portion 31 of the slider 30 is the body 20.
Is in contact with the inner peripheral surface of the guide portion 22b of the
The slanted surface at the end portion of is in contact with the seal member 36 of the slider 30 over the entire circumference. Therefore, the amount of gas that leaks toward the seal member 60 is small, and this minute amount of gas can be reliably prevented from leaking by these seal members 60. In particular, even when the seal member 60 or the like is burned or deteriorated due to a fire or the like, the metal body 20, the slider 30, the coil spring 40, and the bellows tube 10 do not disappear,
Since the mutual contact state can be maintained, it is possible to prevent a large amount of gas from leaking, and it is possible to prevent a situation in which the scale of a fire due to gas leakage is enlarged.

Next, the insertion resistance caused by the seal member 60 when the bellows tube 10 is inserted will be described in detail with reference to FIG. When the bellows tube 10 is inserted into the joint 20, the insertion depth (the insertion depth is the tip of the bellows tube 10 and the tubular portion 2).
3 (which means the distance from the right end surface of 3) increases, the insertion resistance due to the seal member 60 changes. At this time, it is possible to prevent the plurality of peaks 10a from passing through the plurality of protrusions 61 at the same time by the above-described relational expression of nD ≠ mP. Therefore, the rapid increase and the rapid decrease in the insertion resistance due to the seal member 60 do not occur. Does not happen. The insertion resistance caused only by the seal member 60 is shown in FIG.
Appears in G). When the insertion depth is further increased, the bellows tube 1
Since the tip portion of 0 hits the slider 30, insertion resistance due to the coil spring 40 is added,
Insertion resistance increases. Further, the engaging member 5 described above
Insertion resistance caused by the fact that 0 passes over the protrusion 34 of the slider 30 is also added. Therefore, the insertion resistance sharply rises and sharply drops at the moment when the engaging member 50 is disengaged from the slider 30. In FIG. 3, the peak of the insertion resistance generated at this time is indicated by the symbol PK. The operator can prevent the insertion resistance from rapidly increasing and decreasing at this time by the sealing member 60.
It is possible to clearly distinguish it from the comparatively gentle and low insertion resistance caused by the above, and thus it is possible to clearly confirm the completion of the connecting work of the bellows tube 10. The slider 30
Even if there is no protrusion 34 on the inner surface of the bellows tube 1 due to the rapid increase in insertion resistance due to the coil spring 40.
Since it can be recognized that the tip end of 0 has reached the slider 30, the bellows tube 10 can be reliably connected.

The present invention is not limited to the above-mentioned embodiments, and various modes are possible. For example, it can be applied to the case where the body of the gas appliance also serves as the body of the joint. The engagement member may be a coil spring having both ends connected to form an annular shape. Further, it may be a circular elastic ring with a part cut away. Further, it may be an assembly of a coil spring having both ends connected, and a circular elastic ring housed in the coil spring and partially cut away. The intervals of the protrusions formed on the outer periphery of the seal member may be different.

[0026]

As described above, according to the joint of the invention of claim 1, it is possible to prevent the engaging member from falling off before the work of connecting the bellows pipe, the work of connecting the bellows pipe is easy, and the retainer is securely prevented. Thus, the operator can clearly recognize the completion of the connecting work of the bellows tube by the impact when the engaging member fits into the trough of the bellows tube. Moreover, the protrusion of the seal member is the second
Since it strongly hits the inner peripheral surface of the accommodation recess, the seal between the bellows tube and the joint can be performed more reliably. According to the joint of the invention of claim 2, the change in the insertion resistance when the bellows tube passes through the seal member is made smooth so that the operator can clearly recognize this when the bellows tube reaches the slider. Therefore, the work of connecting the bellows tube can be performed more reliably.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state before connecting a bellows pipe of a joint according to the present invention.

FIG. 2 is a cross-sectional view showing a state of the joint after connecting the bellows pipe.

FIG. 3 is a diagram showing insertion resistance corresponding to an insertion depth of a bellows tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Bellows tube 10a ... Mountain part 10b ... Valley part 20 ... Body 22, 24 ... Through hole 24a ... 2nd accommodating recess 24x ... Inlet 28 ... 1st accommodating recess 29 ... Locking part (locking surface) 30 ... Support member (Slider) 33 ... Receiving part 40 ... Coil spring 50 ... Engaging member 60 ... Sealing member 61 ... Protrusion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Wada 4-20-14 Toyohachi, Shinagawa-ku, Tokyo Koyo Industrial Co., Ltd. (72) Keizo Okawa 4-20-14 Toyohachi, Shinagawa-ku, Tokyo No. Koyo Industrial Co., Ltd. (72) Inventor Yasushi Kosugi 4-20-14 Toyohashi, Shinagawa-ku, Tokyo Koyo Industrial Co., Ltd.

Claims (2)

[Claims] 1. A joint for a bellows tube having alternating peaks and valleys, comprising: (a) a through hole, one end of which is provided as an inlet for inserting the bellows tube. On the inner periphery of the through hole, an annular first accommodating recess formed in order toward the inlet, an annular locking portion, and an annular second accommodation recess.
A body having an accommodating recess formed therein; (b) a support member that is accommodated in the body and has a tubular shape, and the end portion on the inlet side is provided as a receiving portion; A coil spring that pushes toward the inlet and positions the receiving portion of the supporting member at a position facing the inner peripheral surface of the first accommodating recess, and (d) forms a substantially annular shape, and is formed on the outer periphery of the receiving portion of the supporting member. It is installed in an elastically expanded state,
When the tip of the bellows tube inserted from the inlet pushes the support member in the direction away from the inlet against the spring,
The diameter of the support member is deviated from the inlet side end of the support member to fit into the outer periphery of the valley portion of the bellows pipe, and in the fitted state of the engaging member, the portion protruding from the outer periphery of the mountain portion of the bellows pipe is An engagement member for preventing the bellows tube from coming off by being locked to the locking part of the body, and (e) an inner diameter smaller than the outer diameter of the mountain portion of the bellows tube, which is housed in the second housing recess. And a plurality of annular projections axially separated from each other, the projections being provided with an annular seal member in contact with the inner peripheral surface of the second accommodating recess. 2. The distance between the protrusions of the seal member is D, the pitch of the peaks of the bellows pipe is P, and n is an integer equal to or smaller than the number of the protrusions minus 1. When m is an integer equal to or less than the maximum value of the number of peaks located on the seal member when the bellows tube passes through the seal member, or an integer smaller than this, a relationship of nD ≠ mP is satisfied. The joint for a bellows tube according to Item 1.