JP4084882B2 - Universal joint for piping - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a universal joint for piping used for gas piping and the like.
[0002]
[Prior art]
A conventional universal joint for piping will be described with reference to FIGS. This universal joint for piping is provided with an outer cylinder 1 and an inner cylinder 5 which are phase-fitted in an axially slidable manner, and a pipe connection port is provided at the outer end of each of the outer cylinder 1 and the inner cylinder 5. Ball joint mechanisms 2 and 6 having portions 21 and 61 are provided. Each of these ball joint mechanisms 2 and 6 has spherical sliding surfaces 22 and 62, and the pipe connection port portions 21 and 61 are connected to the outer cylinder 1 and the inner cylinder by the sliding action of these sliding surfaces 22 and 62. An angular displacement can be made within a certain range with respect to the axis of the cylinder 5. Therefore, according to this universal joint for piping, a pipe (not shown) connected to the pipe connection port portion 21 of one ball joint mechanism 2 and a pipe connected to the pipe connection port portion 61 of the other ball joint mechanism 6. (Not shown) can be connected with a certain bending angle.
[0003]
Moreover, the cylindrical slide housing 3 is attached to the inner side edge part of the outer cylinder 1 of this universal joint for piping. The slide housing 3 holds a dust seal 31, a slide ring 32, an airtight seal material 33, a fireproof packing 34, an airtight seal material 35, and a slide ring 36 arranged in order from the outside to the inside. The materials 33 and 35 are slidable in close contact with the seal surface 51 formed by the outer peripheral surface of the inner cylinder 5. The outer cylinder 1 and the inner cylinder 5 are slidable in the axial direction while the airtight sealing materials 33 and 35 are in close contact with the sealing surface 51 of the inner cylinder 5. Therefore, the displacement in the perspective direction between the pipe connected to the pipe connection port portion 21 of one ball joint mechanism 2 and the pipe connected to the pipe connection port portion 61 of the other ball joint mechanism 6 at the time of an earthquake or the like is reduced. The outer cylinder 1 and the inner cylinder 5 are absorbed by the axial sliding.
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional universal joint for piping, the sealing surface 51 on which the sealing materials 33 and 35 for preventing gas leakage from the pipe slide in close contact is exposed to the outside. It is formed by the outer peripheral surface of the cylinder 5. For this reason, foreign matters such as dust adhere to the seal surface 51, and particularly in outdoor piping, the seal surface 51 is corroded due to rainwater or the like adhering to the seal surface 51. There was a risk of adversely affecting Furthermore, when the entire surface of the universal joint is painted to maintain the aesthetics of the building, such as a gas pipe used for a building lead-in pipe, the coating applied to the sealing surface 51 has an adverse effect on the sealing performance. There was a fear of affecting.
[0005]
The present invention has been made under the above circumstances, and by forming a seal portion for maintaining the airtightness of the gap between the outer tube and the inner tube in a portion that is not exposed to the outside, the outer surface of the inner tube is formed. It is an object of the present invention to provide a universal joint for piping that does not adversely affect the sealing performance of the sealed portion even if foreign matter such as dust or rainwater adheres or a coating film is applied.
[0006]
The present invention also provides a universal joint for piping capable of protecting the sealing surface by preventing dust and rainwater from entering the gap between the outer cylinder and the inner cylinder inserted into the outer cylinder. For the purpose.
[0007]
Furthermore, in the present invention, when a fireproof packing is used for the seal portion for keeping the airtightness of the universal joint for piping, the shavings of the fireproof packing adhere to the airtight seal material. And it aims at providing the universal joint for piping which does not reduce the sealing performance.
[0008]
[Means for Solving the Problems]
A universal joint for piping according to a first aspect of the present invention has a spherical sliding surface and a pipe connection port portion at the outer end of each of an outer cylinder and an inner cylinder that are phase-fitted in an axially slidable manner. In the universal joint provided with the ball joint mechanism, the inner peripheral surface of the outer cylinder is formed as a sealing surface, and can slide on the inner end of the inner cylinder in close contact with the sealing surface. There is provided a sealing material holding portion that holds a sealing material for airtightness, and a gap is provided between the sealing surface and the slide ring that can slide on the sealing surface of the outer cylinder. The refractory packing that is formed and is not in contact with the sealing surface is held.
[0009]
In the universal joint for piping according to the present invention, a sealing surface for maintaining the airtightness of a pipe line and an airtight sealing material sliding in close contact with the sealing surface are inserted into the inner peripheral surface of the outer cylinder and the outer cylinder. The sealing surface and the airtight sealing material are not exposed to the outside because they are provided separately from the sealing material holding portion of the inner cylinder. Therefore, there is no possibility that dust or rainwater adheres to the sealing surface or the airtight sealing material and adversely affects the sealing performance, or a coating film is applied to the sealing surface and adversely affects the sealing performance.
[0010]
According to a second aspect of the present invention, there is provided a pipe universal joint according to the first aspect, in which a cylindrical ring holding a slide ring slidable on the outer peripheral surface of the inner cylinder at an inner end portion of the outer cylinder. A slide housing is provided, and at the end of the slide housing, a dust-proof cover that is formed into a cylindrical shape with a flexible synthetic resin and whose inner surface is slidably contacted with the outer peripheral surface of the inner cylinder is fitted. It is held.
[0011]
The universal joint for piping according to the present invention not only enables the axial displacement of the outer cylinder and the inner cylinder to be smoothly performed by the action of the slide ring, but also allows dust to be collected in the gap between the outer cylinder and the inner cylinder by the dustproof cover. Therefore, the sealing surface and the hermetic sealing material described above are protected from dust and the sealing performance by them is kept good.
[0012]
The universal joint for piping of the invention according to claim 3 is the one according to claim 1 or 2, wherein the pipe universal joint slides on the outer peripheral surface of the inner cylinder on the outer side in the axial direction of the slide ring holding portion in the slide housing. It is said that a waterproof sealing material that adheres freely in a watertight state is held.
[0013]
According to the universal joint for piping of the present invention, moisture such as rainwater enters the gap between the slide housing and the outer cylinder and the inner cylinder by the waterproof seal material held on the outer side in the axial direction of the slide ring holding portion in the slide housing. Therefore, corrosion caused by rusting on the slide ring and seal surface is prevented.
[0014]
[0015]
In the universal joint for piping according to the first aspect of the present invention, not only the axial displacement of the outer cylinder and the inner cylinder is smoothly performed by the action of the slide ring, but also the refractory packing is the inner peripheral surface of the outer cylinder. Because it is non-contact with the seal surface formed by the fire, it is fireproof due to axial displacement (sliding in the axial direction) between the outer cylinder and the inner cylinder during normal operation due to expansion and contraction of the outer cylinder and inner cylinder The packing does not rub against the sealing surface and cause scraping. For this reason, the refractory packing is scraped off, but there is no possibility that it adheres to the hermetic sealing material held in the sealing material holding portion together with the refractory packing and deteriorates the sealing performance.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
1 is a side view of a universal joint for piping according to the present invention, FIG. 2 is a half sectional view showing an enlarged main part of FIG. 1, and FIG. 3 is a partial cross section showing an enlarged main part of FIG. FIG.
[0017]
The piping universal joint of FIG. 1 includes an outer cylinder 1 and an inner cylinder 5 that are fitted together so as to be slidable in the axial direction, and at the outer end of each of the outer cylinder 1 and the inner cylinder 5, The ball joint mechanisms 2 and 6 having the pipe connection ports 21 and 61 are provided. Each of the ball joint mechanisms 2 and 6 has spherical sliding surfaces 22 and 62, and FIG. 4 shows that the pipe connection ports 21 and 61 can be angularly displaced within a certain range with respect to the axis of the outer cylinder 1 or the inner cylinder 5 by the sliding action of the sliding surfaces 22 and 62. The same as described above. Therefore, according to the universal joint for piping of FIG. 1, the pipe (not shown) connected to the pipe connection port portion 21 of one ball joint mechanism 2 and the pipe connection port portion 61 of the other ball joint mechanism 6 are connected. It is possible to connect a pipe (not shown) having an arbitrary bending angle within a certain range. It should be noted that various known configurations can be adopted as specific configurations of the ball joint mechanisms 2 and 6.
[0018]
In FIG. 1, a seal material holding portion is denoted by reference numeral 7. The sealing material holding portion 7 is provided at an inner end portion of the inner cylinder 5 that is slidably inserted in the outer cylinder 1 in the axial direction. As shown in FIGS. 2 and 3, the sealing material holding portion 7 is provided with two recesses 71 and 72 having a shallow depth and two recesses 73 and 74 having a deep depth in an annular shape. Among the two shallow recessed portions 71 and 72, the slide ring 75 is accommodated and held in the recessed portion 71 on the innermost end side, and the fireproof packing 76 is accommodated and held in the other recessed portion 72. Airtight sealing materials 77 and 78 made of rubber rings such as O-rings are accommodated and held in the respective recessed portions 73 and 74. The inner peripheral surface of the outer cylinder 1 is formed as a seal surface 12, and the airtight seal materials 77 and 78 are slidably in contact with the seal surface 12 and the slide ring 75. Are in slidable contact. On the other hand, a small gap S is secured between the fireproof packing 76 and the seal surface 12, and the fireproof packing 76 is not in contact with the seal surface 12 by the gap S. The size of the gap S formed between the refractory packing 76 and the seal surface 12 is such that the flame does not pass or is very difficult to pass when a fire occurs. Therefore, even if the outer cylinder 1 and the inner cylinder 5 slide in the axial direction at normal times, the refractory packing 76 is rubbed against the seal surface 12 and the refractory packing 76 is scraped. , 78 to reduce the sealing performance. Further, even if a flame enters the gap between the outer cylinder 1 and the inner cylinder 5 at the time of the occurrence of a fire, the flame is blocked at the refractory packing 76 and the hermetic sealing material 77 disposed inside the flame is used as a flame. The situation of being exposed to is also prevented.
[0019]
Further, as described above, when the seal surface 12 is formed by the inner peripheral surface of the outer cylinder 1, it is difficult for dust and rainwater to adhere to the seal surface 12. Similarly, when the sealing material holding part 7 is provided at the inner end of the inner cylinder 5 inserted into the outer cylinder 1, the airtight sealing materials 77 and 78 held by the sealing material holding part 7 It is difficult for dust and rain water to adhere to the slide ring 75 and the fireproof packing 76. Therefore, the sealing performance exhibited by the sealing surface 12 and the hermetic sealing materials 77 and 78 is favorably maintained over a long period of time. The same effect is exhibited when the entire surface of the pipe joint is painted.
[0020]
As shown in FIGS. 1 and 2, a cylindrical slide housing 3 is attached to an inner end portion of the outer cylinder 1 of the pipe joint via a taper screw portion 13. The slide housing 3 is formed with a deep recessed portion 37 and a shallow recessed portion 38 that are annularly arranged in order from the outside to the inside, and each of the recessed portions 37 and 38 is waterproof. The sealing material 39 and the slide ring 36 are accommodated and held. The slide ring 36 is slidably in contact with the outer peripheral surface 52 of the inner cylinder 5, and the waterproof sealing material 39 is slidably in contact with the outer peripheral surface 52 of the inner cylinder 5. Further, a dustproof cover 8 formed in a cylindrical shape with a flexible synthetic resin such as elastomer is press-fitted and attached to the end of the slide housing 3, and the inner peripheral surface 81 of the dustproof cover 8 is the inner cylinder 5. Is slidably in contact with the outer peripheral surface of the. Therefore, the situation where dust enters from the outside into the gap between the slide housing 3 and the outer cylinder 1 and the inner cylinder 5 is mainly prevented by the dust-proof cover 8, and the situation where rainwater enters is prevented by the waterproof sealing material 39. This helps to maintain the sealing performance by the sealing surface 12 and the airtight sealing materials 77 and 78 well over a long period of time.
[0021]
In the above-described universal joint for piping, the axial displacement between the outer cylinder 1 and the inner cylinder 5 is smoothly performed by the action of the two slide rings 75 and 36 held by the seal material holding portion 7 and the slide housing 3. . Therefore, the displacement in the perspective direction between the pipe connected to the pipe connection port portion 21 of one ball joint mechanism 2 and the pipe connected to the pipe connection port portion 61 of the other ball joint mechanism 6 at the time of an earthquake or the like is reduced. The outer cylinder 1 and the inner cylinder 5 are absorbed by the axial sliding.
[0022]
【The invention's effect】
According to the present invention, since the seal portion for maintaining the airtightness of the gap between the outer cylinder and the inner cylinder is not exposed to the outside, foreign matter such as dust or rainwater adheres to the outer peripheral surface of the inner cylinder, or the coating film Even if it is applied, there is no possibility that the sealing performance of the sealing portion will be adversely affected, and the initial sealing performance is effectively maintained over a long period of time.
[Brief description of the drawings]
FIG. 1 is a side view of a universal joint for piping according to the present invention.
FIG. 2 is a half cut sectional view showing an enlarged main part of FIG. 1;
FIG. 3 is a partial cross-sectional view showing a main part of FIG. 2 further enlarged.
FIG. 4 is a side view of a conventional universal joint for piping.
5 is an enlarged half-sectional view showing the main part of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Outer cylinder 2,6 Ball joint mechanism 3 Slide housing 5 Inner cylinder 7 Seal material holding part 8 Dust-proof cover 12 Seal surface 21, 61 Pipe connection port part 22, 62 Sliding surface 36 Slide ring 39 Waterproof seal material 77, 78 Airtight Sealing material 75 Slide ring 76 Fireproof packing 81 Inner peripheral surface of dustproof cover

Claims (3)

In a universal joint provided with a ball joint mechanism having a spherical sliding surface and a pipe connection port at the outer end of each of an outer cylinder and an inner cylinder that are phase-fitted in an axially slidable manner,
A sealing material holding portion in which an inner peripheral surface of the outer cylinder is formed as a sealing surface and an airtight sealing material slidable in close contact with the sealing surface is held at an inner end of the inner cylinder It is provided, on the sealing material holding portion, and the seal surface and the slidable slide ring of the outer tube, the non-contact with the sealing surface to form a gap between the seal surface A universal joint for piping, wherein the fireproof packing is held.   A cylindrical slide housing that holds a slide ring that can slide with the outer peripheral surface of the inner cylinder is provided at the inner end of the outer cylinder, and the end of the slide housing is formed into a cylinder with a flexible synthetic resin. The universal joint for piping according to claim 1, wherein a dustproof cover that is formed and whose inner surface is slidably brought into contact with the outer peripheral surface of the inner cylinder is held in a fitting state.   The universal joint for piping according to claim 2, wherein a waterproof sealing material that is slidably and closely contacted with the outer peripheral surface of the inner cylinder is held on the outer side in the axial direction of the slide ring holding portion in the slide housing. .

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