JP2002022078A - Joint and floor heating panel using this joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint facilitating the laying work of a panel body and dispensing with a hose and a floor heating panel using this joint. SOLUTION: This joint comprises an outer cylinder 27, an inner cylinder 23 to be inserted into the outer cylinder 27, stopper mechanisms 24, 25, 30, and 32 for preventing the inner cylinder 23 from dropping out from the outer cylinder 21, and an annular seal member 29 for sealing the inside of the outer cylinder 27 to the outside of the inner cylinder 23. The outer cylinder 21 and the inner cylinder 23 are relatively movable in the axial direction while keeping the sealed state between the both by the seal member 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint used for connecting pipes, for example, and a floor heating panel using the joint.

[0002]

2. Description of the Related Art FIGS. FIG.
Shows a panel body a of a floor heating panel using hot water. The panel main body a is buried between the front plate 1 and the back plate 2, the front plate 1 positioned on the upper side when used as a floor, the back plate 2 attached to the lower surface of the front plate 1. And a pipe mat m. The pipe mat m has a mat shape by connecting thin heat exchange pipes 5 arranged at a fine pitch between a pair of thick main pipes 3 and 4. The main pipes 3, 4
The heat exchange pipe 5 is made of a synthetic resin and has flexibility. The heat exchange pipes 5 are fitted into a plurality of grooves (not shown) formed in the back plate 2 so as to keep the pitch constant.

[0003] The panel body a as described above is
To reduce the overall thickness. When the back plate 2 is made thinner in this way, the diameter of the main pipes 3 and 4 becomes larger than the thickness of the back plate 2. Therefore, through holes 6 and 7 are formed in the back plate 2, and the main pipes 3 and 4 protrude from the through holes 6 and 7. Connectors 8 and 9 are provided at the ends of the main pipes 3 and 4 in a direction perpendicular to the axis thereof. And these connectors 8,
The hot water is supplied to the pipe mat m from 9 and the hot water in the pipe mat m is discharged.

FIG. 1 shows a state in which the panel main body a as described above is laid in a building constructed by a conventional wooden construction method.
4 and 15. As shown in FIG.
Are bonded in a direction orthogonal to the joist 10. However, as shown in FIG.
0, and maintains the strength of the portion where it abuts with the adjacent panel body a. Further, when the panel main body a is laid as described above, the connectors 8 and 9 project below the floor. A hose H is connected to these connectors 8 and 9, and the pipe mats m of the adjacent panel main bodies a are communicated through the hoses H.

[0005] The puller 15 below the panel body a
A heat insulating material 11 is laid on the top. This heat insulating material 11
Is to prevent the heat of the panel body a from escaping below the floor. The heat insulating material 11 has the hose H
Through holes 12 and 13 are formed to pass through. In addition,
In the figure, reference numeral 14 denotes a bundle, and reference numeral 16 denotes a base 16.

On the other hand, FIG. 16 shows a state in which a panel main body a is laid in a building constructed by the panel construction method. In the case of this panel construction method, a main panel 17 is laid on the joist 10, and the strength of the building is maintained by the main panel 17. Therefore, the panel main body a is laid directly on the main panel 17. Since the panel main body a is laid directly on the main panel 17 in this manner, through holes 18 and 19 are formed in the main panel 17 and the main pipes 3 and
4 and connectors 8 and 9 are facing. Then, the hoses H are connected to the connectors 8 and 9 facing the through holes 18 and 19, respectively.
And the main pipes 3 and 4 of both panel bodies a are connected via the hose H. Also in this case, through holes 12 and 13 are formed in the heat insulating material 11 so that the hose H passes therethrough.

[0007]

In the above-mentioned conventional example, the adjacent panel main bodies a are connected by using the connectors 8 and 9 and the hose H.
The main pipes 3 and 4 are connected to each other. However, since the connectors 8 and 9 are mounted at right angles to the axial direction of the main pipes 3 and 4, when the panel body a is laid, the connectors 8 and 9 are connected. , 9 project below the floor. Therefore, when laying the panel main body a, the worker had to go under the floor and connect the hose H to the main pipes 3 and 4, and the workability was poor. Also, the heat insulating material 11
And the main panel 17 have through holes 12, 13, 18, 19
Has to be formed, and there is a problem that processing cost is required. In particular, the main panel 17 has through holes 18, 1
There is also a problem that the strength is reduced when 9 is opened.

On the other hand, the hose H connected to the connectors 8 and 9 has a U-shape as shown in the figure. When the hose H has a U-shape as described above, air is accumulated in the main pipes 3 and 4 due to the difference in height. It will be easier. Further, once air is accumulated in the main pipes 3 and 4, it cannot be easily removed. If the air remains in the main pipes 3 and 4, the flow path resistance increases. Therefore, when a plurality of panel bodies a are connected in parallel, hot water is supplied to the main pipes 3 and 4 where the air is stored. It is hard to be done. As a result, the panel body a composed of the main pipes 3 and 4
Has a lower temperature than the surface temperature of the other panel body a, and there is a problem that uneven temperature occurs on the floor. SUMMARY OF THE INVENTION An object of the present invention is to provide a joint capable of simplifying the work of laying a panel body and solving the various problems described above, and a floor heating panel using the joint.

[0009]

According to a first aspect of the present invention, there is provided an outer cylinder,
An inner cylinder inserted into the outer cylinder, a stopper mechanism for restricting the inner cylinder from coming off from the outer cylinder, and an annular seal member for sealing between the inner periphery of the outer cylinder and the outer periphery of the inner cylinder are provided. The outer cylinder and the inner cylinder are relatively movable in the axial direction while maintaining a state in which the two cylinders are sealed by a seal member.

[0010] The second invention is the above-mentioned first invention, wherein:
The stopper mechanism is characterized in that when the inner cylinder inserted into the outer cylinder to the base end is moved by a predetermined amount in the removal direction, the inner cylinder is prevented from coming off.

A third invention is characterized in that, in the first and second inventions, the outer cylinder and the inner cylinder are flattened.

According to a fourth aspect of the present invention, in a floor heating panel in which a pipe mat in which a plurality of heat exchange pipes are connected between a pair of main pipes is embedded in a panel body, joints are formed at both ends of the main pipe. One of the outer cylinder and the inner cylinder to be connected is connected in the same direction as the axis of the main pipe, while the joint has a stopper mechanism for restricting the inner cylinder inserted into the outer cylinder from coming off, and a An annular seal member for sealing between the periphery and the outer periphery of the inner cylinder, wherein the outer cylinder and the inner cylinder are relatively movable in the axial direction while maintaining a state in which the two cylinders are sealed by the seal member. It is characterized by.

According to a fifth aspect of the present invention, in a floor heating panel in which a pipe mat in which a plurality of heat exchange pipes are connected between a pair of main pipes is embedded in a panel body, the main pipe is bent at 90 degrees. A sub pipe is connected to the tip via a first joint consisting of an outer cylinder and an inner cylinder,
Also, this sub-pipe is connected to the main pipe in the opposite direction 90.
And the distal end thereof is connected to one of the outer cylinder and the inner cylinder constituting the second joint.
The joint is provided with a stopper mechanism that regulates the inner cylinder inserted into the outer cylinder from coming off, and an annular seal member that seals between the inner periphery of the outer cylinder and the outer periphery of the inner cylinder. The outer cylinder and the inner cylinder are relatively movable in the axial direction while maintaining a sealed state between the cylinders.

[0014]

1 to 5 show a first embodiment. The joint shown in FIG. 1 includes a first joint portion 20 and a second joint portion 21. As shown in FIG. 2, the first joint portion 20 includes a pair of first pipes 23, 2 inside a body 22 thereof.
3 and one ends of the first pipes are projected from the body 22. The inner pipe of the present invention is constituted by the first pipes 23 protruding from the body 22. The body 22 of the first joint portion 20 is formed with a pair of arm portions 24 constituting a stopper of the present invention. These arm parts 2
4 and 24 have elasticity such that their tips bend toward the body 22 side. And this arm part 24, 2
Stoppers 25, 25 are formed at the tip of 4.

On the other hand, the second joint portion 21 has a pair of second pipes 2 corresponding to an outer cylinder of the present invention in a body 26 thereof.
7, 27 are incorporated. These second pipes 27, 2
The inner diameter of 7 is slightly larger than the outer diameter of the first pipes 23, 23 so that the first pipes 23, 23 can be inserted into the second pipes 27, 27. In addition, one end of each of the second pipes 27 is protruded from the body 26, and the outer diameter of the protruded portion is increased. And on the inner circumference of the part where the outer diameter is increased,
The annular recesses 28, 28 are formed, and these annular recesses 28, 2 are formed.
8, an O-ring 29 corresponding to the seal member of the present invention,
29 is incorporated.

The second in which the O-rings 29, 29 are incorporated is described.
The first pipe 2 is connected to the pipes 27, 27 as shown in FIG.
3 and 23, the O-ring 2 is inserted as shown in FIG.
9 and 29 are pressed against the outer periphery of the first pipes 23 and 23. The O-rings 29, 29 are connected to the first pipe 2
The first pipes 23, 2 are pressed against
The sealing performance between the outer periphery of 3 and the inner periphery of the second pipes 27, 27 is maintained.

As shown in FIG. 2, a pair of holding pieces 30, 30 are provided in the body 26 of the second joint portion 21, and guide holes 31, 31 are formed in the holding pieces 30, 30. . Then, as shown in FIG.
When the first pipes 23, 23 are inserted into the insides 7, 27, the tapered surfaces 25b, 25b formed on the stoppers 25, 25
The arm portions 24 are inserted into the guide holes 31 while being pressed by the restricting portions 32 provided on the holding pieces 30. Then, as shown in FIG. 4, the first pipe 23,
When the first pipes 23, 23 are inserted until the flanges 23a, 23a abut on each other, the end surfaces 25a, 25a of the stoppers 25, 25 provided on the arms 24, 24, and the regulating portions provided on the holding pieces 30, 30. 32, 32 end face 32
a and 32a are set so as to have a predetermined interval T therebetween.

When the first joint portion 20 moves in the detaching direction from this state, the end faces 25a, 25a of the stopper 25
When it hits the end faces 32a, 32a of the regulating portions 32, 32,
The relative movement between the first joint 20 and the second joint 21 is restricted. That is, the first joint portion 20 and the second joint portion 21 can be relatively moved in the axial direction by the distance T. When the first joint portion 20 and the second joint portion 21 move relative to each other, the first pipe 23
The state of being inserted into the pipe 27 is maintained, and between the two pipes is sealed by an O-ring 29. The arms 24, 24, the stoppers 25 provided on the arms 24, 24, and the holding pieces 3
0, 30 and regulating portions 3 provided on the holding pieces 30, 30
2, 32 constitute the stopper mechanism of the present invention.

FIG. 6 shows a panel body A using the first and second joint portions 20 and 21. The panel main body A includes a front plate 33, a back plate 34, and a pipe mat M. The main pipe 35 constituting the pipe mat M,
36 has a rectangular cross section, and the thickness of its short side is substantially the same as that of the back plate 34. The main pipes 35, 36 thus formed are connected to through holes 37, 3 formed in the back plate 34.
8 so that the main pipes 35 and 36 do not protrude from the back plate 34.

The first and second joint portions 20, 21 are also
As shown in FIG. 5, the bodies 22 and 26 have a rectangular shape, and the short sides thereof have a thickness substantially equal to the thickness of the back plate 34. The first and second joint portions 20 and 21 are fixed to both ends of the main pipes 35 and 36 in the same direction as the axes of the main pipes 35 and 36. The body 2 of the first and second joints 20 and 21 is used.
Reference numerals 2 and 26 are made of synthetic resin, and the first and second joint portions 20 and 21 and the main pipes 35 and 36 are fixed by thermal welding.

FIG. 7 is a view showing a state in which a plurality of the panel main bodies A are laid from the back plate 34 side. As shown in the figure, a plurality of panel bodies A1 to A6 are arranged side by side, and a first joint part 20 and a second joint part 21 provided on each panel body are opposed to each other. Then, the first joint portion 20 and the second joint portion 21 facing each other are connected. With this connection, the panel bodies A1 to A6 are connected in parallel.

The main headers 36 of the panel bodies A3 and A6 are connected to the supply header 3 via a pipe 37.
8 and a return header 39 is connected to the main pipe 35 of the panel bodies A1 and A4 via a pipe 37. Then, the hot water is supplied from the supply header 38 to the pipe mats M of the panel bodies A1 to A6, and the hot water guided to the pipe mats M is returned to the return header 39.
To be discharged through. A pipe 56 is connected to the supply header 38, and hot water from a hot water supply source (not shown) is supplied from the pipe 56. Further, a pipe 57 is connected to the return header 39, and the hot water is returned to the hot water supply source via the pipe 57.

If the panel body A provided with the first and second joint portions 20 and 21 is used, the main pipes 35 and 3 facing each other can be used.
6 can be directly connected via the first and second joint portions 20 and 21. In addition, since the thickness of the first and second joint portions 20 and 21 is substantially the same as the thickness of the back plate 34, the connecting portion of the main pipes 35 and 36 does not protrude below the floor.
Therefore, when laying the plurality of panel main bodies A, the pipe mats M of the adjacent panel main bodies A can be easily connected to each other without the worker getting under the floor.

Further, since the main pipes 35 and 36 and the first and second joint portions 20.21 do not protrude from the lower surface of the panel main body A, the panel main body A is directly laid on the main panel in a panel construction method building. In addition, it is not necessary to form a through hole in the main panel. Therefore, the operation cost when laying the panel main body A can be reduced. Further, since no through hole is formed in the main panel, the strength of the main panel does not decrease. Further, in the panel body A, the conventional hose is unnecessary, so that the through-hole conventionally formed for passing the hose does not need to be formed in the heat insulating material. Further, since no hose is used, there is no problem that air is accumulated in the main pipe and temperature unevenness occurs.

On the other hand, the positions of both ends of the main pipes 35 and 36 provided in the panel body A are defined as panel body A
May be displaced in the axial direction due to an error generated when manufacturing the panel body, an assembly error generated when laying the panel body A, or the like. When the positions of both ends of the main pipes 35 and 36 are shifted in the axial direction, the positions of the first joint portion 20 and the second joint portion 21 fixed to both ends are also shifted, so that the first joint portion 20 and the second joint portion opposed to each other. The interval with the part 21 changes.

The panel body A is adapted to cope with a change in the distance between the first joint portion 20 and the second joint portion 21 as described above. That is, as described above, the first and second joint portions 20, 21 can be adjusted in the axial direction by the distance T in the connected state. Therefore, the opposing first and second joint portions 20, 21
Even if the distance between them changes due to an assembling error or the like, if the connection position of the first and second joint portions 20 and 21 is adjusted in the axial direction, they face each other via the first and second joint portions 20 and 21. The main pipe 35 or 36 can be connected. That is, the connection portion of the joint can absorb a dimensional error in the axial direction of the main pipe.

The second embodiment shown in FIGS.
This is a modification of the configuration of the first and second pipes of the embodiment.
That is, as shown in FIG. 8, the first pipe 41 is incorporated into the body 46 of the first joint portion 40 and the second joint portion 42
The second pipe 43 is incorporated in the body 47 of the first embodiment.
As shown in FIG. 10, the first and second pipes 41 and 43 have a thin and long cross-sectional shape. Then, as shown in FIG. 9, the first pipe 41 can be inserted into the second pipe 43. As shown in FIG. 8, an annular groove 44 is formed on the inner periphery of the second pipe 43, and an O-ring 45 is incorporated in the annular groove 44.
When the first pipe 41 is inserted into the second pipe 43, the O-ring 45 is pressed against the outer periphery of the first pipe 41 to seal between the two pipes 41, 43. I do.

According to the second embodiment, the cross section of the first and second pipes 41 and 43 is flattened, so that the thickness of the first and second joints 40 and 42 themselves is kept constant, and The area is larger than that of the first embodiment.
If the flow path area is increased in this way, the flow resistance can be reduced when a large flow rate flows. The first pipe 41 corresponds to the inner cylinder of the present invention, and the second pipe 4
Reference numeral 3 corresponds to the outer cylinder of the present invention. The shapes of the inner cylinder and the outer cylinder are determined according to the flow rate passing therethrough and the flow path resistance.

FIG. 11 is a diagram showing a state in which panel bodies B1 to B3 using the joints of the second embodiment are laid from the back plate 41 side. A through hole 49 is formed in the back plate 48 of the panel body B2, and a cutout portion 50 is formed at one end of the through hole 49. In this notch 50, FIG.
As shown in (1), one end of the main pipe is located, and an elbow pipe 51 bent at 90 degrees is connected to one end of the main pipe.

At the end of the elbow pipe 51, a second
The joint 42 is fixed, and the first joint 40 is connected to the second joint 42. And these first and second joints 4
0, 42 constitute the first joint 54 of the present invention. Note that, without using the elbow pipe 51, one end of the main pipe 36 is bent at 90 degrees, and
The joint 54 may be connected.

The first joint 40 has a sub-pipe 52
Are connected. The sub-pipe 52 is also bent at 90 degrees.
Reversed to 1. The second joint 42 is fixed to the tip of the sub pipe 52. On the other hand, a crank-shaped pipe 53 is connected to one end of the main pipe 36 of the panel main body B1 adjacent to the panel main body B2, and a first joint portion 40 is fixed to an end of the pipe 53.
Then, the first joint portion 40 is connected to the second joint portion 42 connected to the sub-pipe 52 to form a second joint 55.

As described above, the first joint 54 and the second joint 55
The panel body B2 having the structure described above can absorb the dimensional error in the X-axis direction shown in FIG. 12 by the second joint 55, and can absorb the dimensional error in the Y-axis direction by the first joint 54. That is, according to the panel body B, not only the dimensional error in the X-axis direction that occurs when a plurality of panel bodies are laid,
Dimensional errors occurring in the Y-axis direction can also be absorbed by the joints of the joint. Therefore, when a plurality of panel bodies B are laid, the main pipe 3 of each panel body B
5, 36 can be reliably connected.

The joint of the first embodiment may be used as the joint of the panel bodies B1 to B3, and the joint of the second embodiment may be used as the joint of the panel body A shown in FIGS. Is also good. In the first and second embodiments, the O-rings 29, 45 are provided on the second pipes 27, 43 side.
These O-rings 29, 45 are connected to the first pipe side 23, 41.
May be provided.

[0034]

According to the first aspect of the invention, since the two tubes can be connected by inserting the inner tube into the outer tube, the connection work can be simplified. Further, since a hose or the like is not required to connect the outer cylinder and the inner cylinder, it is not necessary to form a through-hole for passing the hose or the like. Further, there is no inconvenience such as accumulation of air in the hose and difficulty in flowing the fluid. Furthermore, since the outer cylinder and the inner cylinder can move relative to each other in the axial direction while maintaining a state of being sealed by the seal member, even if the distance between the two cylinders varies due to dimensional errors, etc. It can be connected to the inner cylinder.

According to the second aspect, the inner cylinder is prevented from coming off from the outer cylinder by the stopper mechanism, and the two cylinders can be relatively moved in the axial direction by a predetermined amount while maintaining the connected state. it can. According to the third aspect, since the outer cylinder and the inner cylinder are flattened, the thickness of the joint itself can be reduced.

According to the fourth aspect, the outer pipe or the inner pipe forming the joint is connected to both ends of the main pipe in the axial direction of the main pipe.
Do not protrude under the floor. Therefore, the main pipes of adjacent panel bodies can be connected to each other even when the worker does not go under the floor when laying the panel bodies. Therefore, workability when laying the panel body can be improved.

Further, since the main pipes are connected to each other without using a hose, it is not necessary to form a through hole for passing a hose or the like. Further, there is no inconvenience such as accumulation of air in the hose, which makes it difficult for hot water to flow. Furthermore, since the outer cylinder and the inner cylinder can be moved in the axial direction while maintaining the connected state, even if the distance between the main pipes of adjacent panels changes due to an axial dimensional error, these two main pipes can be moved. Pipes can be connected.

According to the fifth aspect, the dimensional error in the direction perpendicular to the axis of the main pipe can be absorbed by the first joint, and the dimensional error in the axial direction of the main pipe can be absorbed by the second joint. Therefore, the main pipes of adjacent panels can be securely connected to each other.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment, showing a state before connecting a first joint portion 20 and a second joint portion 21.

FIG. 2 is a cross-sectional view of the first embodiment, showing a state before connecting a first joint 20 and a second joint 21. FIG.

FIG. 3 is a perspective view of the first embodiment, showing a state in which a first joint portion 20 and a second joint portion 21 are connected.

FIG. 4 is a cross-sectional view of the first embodiment, showing a state in which a first joint 20 and a second joint 21 are connected.

FIG. 5 is a side view of FIG.

FIG. 6 is a perspective view showing a panel main body A using a first joint portion 20 and a second joint portion 21.

FIG. 7 is a view of a state in which panel main bodies A1 to A6 are laid, as viewed from the back side.

FIG. 8 is a cross-sectional view of the second embodiment, showing a state before the first joint 40 and the second joint 42 are connected.

FIG. 9 is a cross-sectional view of the second embodiment, showing a state in which a first joint 40 and a second joint 42 are connected.

FIG. 10 is a side view of FIG. 9;

FIG. 11 is a view of a state in which panel bodies B1 to B3 are laid, as viewed from the back side.

FIG. 12 is an enlarged view of a main part of FIG. 11;

FIG. 13 is a view showing a conventional example, and is a perspective view of a panel main body a.

FIG. 14 is a perspective view showing a laid state of the panel main body a.

FIG. 15 shows a panel body a in a wooden conventional construction method.
It is sectional drawing which shows the state which laid.

FIG. 16 is a cross-sectional view showing a state in which a panel main body a is laid in a building by the panel construction method.

[Explanation of symbols]

 A, B Panel main body M Pipe mat 5 Heat exchange pipe 23, 41 First pipe 27, 43 corresponding to inner cylinder of the present invention Second pipe 24 corresponding to outer cylinder of the present invention Arm constituting stopper mechanism of the present invention Part 25 Stopper 29, 45 of the stopper mechanism of the present invention 29, 45 O-ring of the seal member of the present invention 30 Holding piece, 32 of the stopper mechanism of the present invention 32 Restrictor 35, 36 of the stopper mechanism of the present invention Main Pipe 54 First joint 55 Second joint

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H104 JA08 JB02 JC09 JD09 KA04 KB11 LF05 LG03 LG23 3J106 AB01 AB07 BA01 BB01 BC04 BC11 BD01 BE29 CA02 EA03 EB03 EC01 EC06 ED06 EE02 EF04 EF05 FA08 3L070 BD01

Claims (5)

[Claims] An outer cylinder, an inner cylinder inserted into the outer cylinder,
A stopper mechanism that regulates the inner cylinder from coming off from the outer cylinder, and an annular seal member that seals between the inner periphery of the outer cylinder and the outer periphery of the inner cylinder are provided. A joint characterized by being relatively movable in the axial direction while maintaining a state in which a seal is provided between the two cylinders. 2. The stopper mechanism, when the inner cylinder inserted into the outer cylinder up to the base end is moved by a predetermined amount in the removal direction,
2. The joint according to claim 1, wherein the joint is restricted from coming off. 3. The joint according to claim 1, wherein the outer cylinder and the inner cylinder are made flat. 4. In a floor heating panel in which a pipe mat in which a plurality of heat exchange pipes are connected between a pair of main pipes is embedded in a panel body, an outer cylinder or an inner pipe forming a joint is provided at both ends of the main pipe. One of the tubes,
While connected in the same direction as the axis of the main pipe, the joint has a stopper mechanism for restricting the inner cylinder inserted into the outer cylinder from coming off, and a seal between the inner circumference of the outer cylinder and the outer circumference of the inner cylinder. A floor heating panel comprising an annular seal member, wherein the outer cylinder and the inner cylinder are relatively movable in the axial direction while maintaining a state in which the two cylinders are sealed by the seal member. 5. In a floor heating panel in which a pipe mat in which a plurality of heat exchange pipes are connected between a pair of main pipes is embedded in a panel body, the main pipe is bent at 90 degrees and an outer cylinder is provided at the end thereof. A sub-pipe is connected via a first joint consisting of an inner cylinder and an inner cylinder, and the sub-pipe is bent at 90 degrees in a direction opposite to that of the main pipe, and the distal end of either the outer cylinder or the inner cylinder constituting a second joint is formed. The first and second joints are connected to each other, and a stopper mechanism for restricting the inner cylinder inserted into the outer cylinder from coming off, and a seal between the inner circumference of the outer cylinder and the outer circumference of the inner cylinder are provided. A floor provided with an annular seal member, wherein the outer cylinder and the inner cylinder of the first and second joints are relatively movable in the axial direction while maintaining a state in which the two cylinders are sealed by the seal member. Heating panel .