JP7632912B2 - Swing joint - Google Patents

Description

This invention relates to joints for water pipes and the like, and in particular to a swinging joint that absorbs the swinging motion of pipes before and after the joint.

It has long been known that swing-type pipe joints are used in water piping to absorb earthquakes and other vibrations when connecting pipes with joints.

JP 2013-249894 A JP 2015-187499 A

All of these known technologies are called expandable flexible joints, and when the joint body and joint pipe are connected, the joint pipe is configured to expand and contract within a certain range relative to the joint body, and at the same time, to swing within a certain angle range. This is intended to absorb stress by allowing the joint body and joint pipe to swing using a ball joint when vertical vibrations such as those caused by an earthquake are applied to the joint, and by allowing the joint pipe to expand and contract relative to the joint body when a certain amount of stress is applied.

These known technologies have the problem that the number of parts is increased because it is necessary to incorporate a configuration for rocking and a configuration for expansion and contraction into the joint structure. In addition, because the configuration for expansion and contraction and the configuration for rocking must be concentrated in the same location, there is also the problem that the overall size increases, and it is difficult to achieve space saving due to the size of the joint.

Conventionally, in order to absorb vibrations caused by earthquakes and the like, it was thought that this type of joint needed to have a structure in which the joint body and the joint pipe could swing and expand and contract at the same time, and joints had been developed to achieve this. However, in order to achieve both of these, structures according to each function were required, which resulted in a problem of a large number of parts. In other words, because each of these functions corresponds to a different movement, there are few areas where the parts used can be shared.

On the other hand, earthquake vibrations are characterized by P waves arriving first, followed by S waves. P waves themselves are often micro-vibrations, while the subsequent S waves are much larger and have more energy than P waves. However, if the energy is too great, the joint structure cannot absorb the energy even if it uses both sway and expansion, and the joint is destroyed. In other words, in the case of a large earthquake, even if the sway mechanism and contraction mechanism are applied simultaneously, the joint cannot absorb the stress without breaking. If this is the case, a structure that omits the expansion function and uses only the sway function to handle earthquakes up to medium scale can reduce the number of parts, rather than using known expansion joints that are structurally complex. The inventor focused on this point and developed a swing-type joint that can handle sway such as earthquakes by reducing the number of parts.

In order to achieve these objectives, the swing joint of the present invention is basically composed of a joint body and a joint pipe connected to the joint body. The joint body has a water passage hole in the center of the longitudinal direction and a large diameter section on the inside of the tip side that expands from the side of the water passage hole. The joint pipe has a spherical section on the outer surface of the joint body side and a cylindrical section extending from this spherical section. A spherical section restriction ring is attached to the inner circumference of the large diameter section and has a negative curved surface section that matches the curvature of the spherical section on the inner circumference, allowing the spherical section to swing relative to the negative curved surface section. In this configuration, a tightening ring is used to connect the joint pipe to the joint body, and a swing joint can be completed with just three parts.

The tip of the spherical part is also terminated by cutting off the outer arc surface. In this case, the straight pipe does not protrude toward the fitting body from the arc configuration as in Patent Document 2, for example, so no extra space is required even when the fitting pipe is swung, making it possible to save space.

Furthermore, for the purpose of watertightness, an O-ring is provided in the space formed by the sphere, the tightening ring, and the expanding portion of the fitting body. Conventionally, a number of O-rings were used for watertightness according to the locations where watertightness is required, but in this invention, one O-ring is used to simultaneously watertightly watertight two locations, which contributes to reducing the number of parts.

In the present invention, the above-mentioned measures are adopted, so that the number of parts required is reduced and the joint pipe can be allowed to swing relative to the joint body. In addition, the number of parts can be further reduced by using only one O-ring.

FIG. 2 is a perspective view of a swing joint of the present invention; Same, disassembled diagram. The same, half-cut longitudinal section view.

Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. FIG. 1 is a perspective view showing one embodiment of the swing joint of the present invention, and FIG. 2 is a perspective view showing the components constituting the joint in an exploded form, in which 1 is a joint body with a water passage formed in the longitudinal center, and 2 is a joint pipe. Basically, these two components are combined to form the swing joint of the present invention. The joint pipe 2 has a straight cylindrical portion 3 and a spherical portion 4 on the joint body 1 side, and the cylindrical portion 3 and the spherical portion 4 are integrated. In addition, a water passage 5 is provided in the longitudinal center. 6 is an O-ring that is sandwiched between the joint body 1 and the joint pipe 2 to stop water. 7 is a tightening ring whose outer thread portion 7a is screwed into the large diameter portion 1a formed on the tip side of the expansion portion of the joint body 1, and is used to connect the joint pipe 2 to the joint body 1, and its inner surface has a negative curved surface portion 7b with a negative curvature that matches the curvature of the spherical portion 4 of the joint pipe 2. 8 is a boot made of soft resin to prevent dirt and dust from entering the joint body 1, joint pipe 2, and tightening ring 7, etc.

Figure 3 is a half-section showing the above-mentioned configuration assembled, in which the joint pipe 2 is inserted into the joint body 1, and the tightening ring 7 is screwed onto the joint body 1. In this case, when the tightening ring 7 is tightened, the tip of the tightening ring 7 abuts against the butt portion 9 of the joint body 1, and at the same time, the spherical portion 4 of the joint pipe 2 is held in abutment against the inner surface expansion portion 10 of the joint body 1. And, since the spherical portion 4 of the joint pipe 2 is supported by two points, the negative curved surface portion 7b of the inner surface of the tightening ring 7 and the inner surface expansion portion 10 of the joint body 1, the joint pipe 2 is allowed to swing relative to the joint body 1. In the structure of this embodiment, the swing angle of the joint pipe 2 is designed to be ±8 degrees, as shown by arrows A and B. If swinging of about ±8 degrees is allowed, it is possible to sufficiently absorb vertical vibrations caused by normal earthquakes. Note that the swing angle of ±8 degrees is for this embodiment, and it is possible to design it to a larger swing angle. In this case, however, the overall structure will be larger, but the basic configuration will be the same as in this embodiment.

The reason why the spherical part 4 is supported at two points, the negative curved surface part 7b of the tightening ring 7 and the inner surface expansion part 10 of the joint body 1, is to suppress rattling when the joint pipe 2 swings and to ensure smooth swinging. However, if the negative curved surface part 7b alone can reliably support the spherical part 4, it is possible to omit the support by the inner surface expansion part 10. In this embodiment, the tightening ring 7 and the large diameter part 1a are connected by a screw, but what is necessary is that the tightening ring and the large diameter part are reliably connected and the spherical part 4 can be accurately positioned. For example, fitting the two parts together is also included in the scope of the present invention. In other words, it is sufficient for the tightening ring 7 to function as a regulating ring for the spherical part 4. Also, 11 is a step part formed on the inner joint body side of the joint pipe 2, and when the polyvinyl chloride pipe is directly inserted, the polyvinyl chloride pipe can be reliably attached by inserting it up to this step part 11. Therefore, other parts such as a polyvinyl chloride socket, which were necessary in the past, are not required.

In the configuration of this embodiment, there are two locations where fluids such as tap water flowing inside can accidentally leak: the contact surface between the spherical portion 4 of the joint pipe 2 and the tightening ring 7, and the screw-on portion between the large diameter portion 1a of the joint body 1 and the tightening ring 7. Therefore, an O-ring 6 is provided in one location to seal both of these simultaneously. In other words, the swing joint of this embodiment achieves sealing in two locations with a single O-ring 6. This not only provides highly accurate watertightness, but also reduces the number of parts and makes parts management easier.

The swing joint shown in this embodiment is just one example, and making the spherical portion 4 larger to further increase the swing angle and lengthening the contact length of the inner expansion portion 10 of the joint body 1 with the spherical portion 4 are part of the design changes and are within the scope of the present invention.

Reference Signs List 1: joint body 2: joint pipe 3: cylindrical portion 4: spherical portion 6: O-ring 7: tightening ring 9: butt portion 10: inner surface expansion portion 11: step portion

Claims (3)

A swing joint comprising a joint body and a joint pipe connected to the joint body,
The joint body includes:
A water vent hole in the longitudinal center;
A large diameter portion that expands from a side surface of the water passage hole and is provided on the inside of the tip side;
Equipped with
The joint pipe is
A spherical portion provided on an outer surface of the joint body;
A cylindrical portion extending from the spherical portion;
a step portion that is tapered and inclined on the inner joint body side inside the spherical portion so that the diameter becomes smaller as the step portion moves away from the cylindrical portion ;
Equipped with
The inner surface of the joint pipe is formed so that a water pipe is inserted through the cylindrical portion to the step portion,
The swing joint further includes a regulating ring that is attached to the inner circumferential side of the large diameter portion of the joint body, has a negative curved surface portion on the inner circumferential side that matches the curvature of the spherical portion, and positions the spherical portion;
A swing joint, characterized in that the spherical portion is capable of swinging relative to the negative curved surface portion. 2. A swing joint according to claim 1 , wherein at least a portion of said step is provided on a side farther away from said cylindrical portion than said restraining ring . 3. A swing joint as claimed in claim 1 or 2, wherein an O-ring is provided in the space formed by the spherical portion, the regulating ring and the expansion portion of the joint body, and at least a portion of the step portion is provided inside the O-ring .

Images