JP2003232062A - Drain pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate bothersome work of incorporating a backflow preventive plate into a conventional two-body drain pipe joint consisting of an upper joint and a lower joint each having a horizontal branch pipe receptacle, at a location on an upper side of a lower inflow port, at the time of mounting the drain pipe joint, the backflow preventive plate being produced separately from the drain pipe joint, the bothersome work being required in order to prevent drain of human waste flowing from an upper horizontal branch pipe from flowing backward into a lower horizontal branch pipe for waste water, and to provide a new two-body drain pipe joint which dispenses with bothersome incorporating work at the time of mounting the drain pipe joint. <P>SOLUTION: According to the new drain pipe joint, a backflow preventive projection 30 for preventing drain of human waste L1 flowing from an upper stage is formed at an upper portion of a waste water inflow port 22a of a lower joint 20, in a manner protruding toward the interior of the pipe, and a leftward inclining surface 30a for generating swirl is formed on an upper surface of the backflow preventive projection 30. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drainage pipe joint for connecting a lateral branch pipe of each floor to a vertical pipe drainage route in a drainage route of a high-rise apartment, for example.

[0002]

2. Description of the Related Art Conventionally, a drain pipe joint of this type is provided with a so-called two-body type drain pipe joint which is divided into an upper joint on the upstream side and a lower joint on the downstream side. An upstream stand pipe and a horizontal branch pipe for draining a toilet, for example, are connected to the upper joint, and a downstream stand pipe and a horizontal branch pipe for, for example, miscellaneous draining are connected to the lower joint. According to this two-body joint, the relative position around the pipe axis of the upper branch side horizontal branch pipe receiving port and the lower joint side horizontal branch pipe receiving port can be arbitrarily selected, so construction is performed according to the site. Therefore, the versatility of the drainage pipe joint can be improved. In addition, in this specification, the tube axis refers to the tube axis of a vertical pipe unless otherwise specified.

However, in this two-body type joint, as described above, when the horizontal branch pipe for draining the toilet bowl is connected to the upper joint side and the horizontal branch pipe for miscellaneous drainage is connected to the lower joint side. ,
When the side branch pipe outlet for miscellaneous drainage is positioned on the opposite side of the side branch pipe outlet for toilet drainage, the inflowing toilet flush flows back into the side branch pipe for miscellaneous drainage through the side branch pipe outlet on the opposite side. Problem occurs. Therefore, a construction mode in which the downstream side branch pipe receiving port is located on the side opposite to the upstream side branch pipe receiving port is generally avoided. However, such a construction form may be required in some cases, and in this case, it is necessary to solve the above-mentioned problem of backflow. Conventionally, in order to solve this backflow problem, for example, Japanese Patent Laid-Open No. 9-273
As disclosed in Japanese Laid-Open Patent Publication No. 197, there is known a technique of providing a wall portion for preventing backflow at an opening portion of a side branch pipe receiving port for miscellaneous wastewater on a pipe inner wall surface side. According to the backflow prevention wall portion, it is possible to prevent the toilet drainage flowing from the upstream side from colliding with the backflow prevention wall portion and flowing back into the lateral branch pipe on the downstream side.

[0004]

However, the above-mentioned conventional backflow prevention wall portion is provided on the inner peripheral side of the annular support pipe portion prepared separately from the drain pipe joint, and the support pipe is provided. By interposing the portion between the upper joint and the lower joint, the backflow prevention wall portion is positioned above the lateral branch pipe receiving port on the downstream side. As described above, the conventional backflow prevention wall portion needs to be separately prepared and incorporated between the upper joint and the lower joint at the time of construction. Therefore, it is an object of the present invention to provide a two-body type drain pipe joint that requires no trouble during construction and can prevent backflow to the lateral branch pipe receiving port on the downstream side.

[0005]

For this reason, the present invention provides a drainage pipe joint having the construction described in the respective claims. According to the drain pipe joint of claim 1, when the upper joint and the lower joint are connected in a state in which the receiving port for connecting the lower lateral branch pipe is located on the side opposite to the receiving port for connecting the upper lateral pipe. To
For example, urinal drainage flowing from the upper side branch pipe collides with the backflow prevention convex portion on the opposite surface side after flowing into the pipe, thereby preventing the urinal drainage from flowing back to the lower side branch pipe. . The flow of the toilet drainage that has collided with the backflow prevention protrusion changes into a flow along the pipe inner wall surface due to the inclined surface of the backflow prevention protrusion, whereby the drainage smoothly flows down along the pipe inner wall surface. In this way, since the backflow preventing convex portion for preventing the backflow of the drainage to the lateral branch pipe receiving port on the lower joint side is integrally provided on the inner peripheral surface of the lower joint, the labor of the conventional construction is reduced. It is possible to prevent the backflow of the drainage to the lateral branch pipe receiving port on the downstream side without applying the pressure. According to the drainage pipe joint of the second aspect, in addition to the above-described function and effect, the drainage flowing along the inner wall surface of the rear pipe after colliding with the backflow preventing convex portion can be efficiently placed on the swivel guide, and thereby the swirling flow can be reliably performed. Can be generated to maintain an air core (a cavity communicating with the atmosphere) along the tube axis.

According to the drainage pipe joint of the third aspect, in addition to the above-mentioned effects, the drainage flown into the pipe joint through the upper lateral branch pipe collides with the backflow preventing convex portion, so that the drainage pipe is counteracted. A clockwise swirling flow is provided, which prevents backflow to the lateral branch pipe on the lower side of the drainage and allows the drainage to flow down smoothly. According to the drain pipe joint of claim 4, in addition to the above-described function and effect, the drainage flowing into the pipe joint through the upper side branch pipe collides with the backflow preventing convex portion and is branched leftward and rightward. The backflow to the lower side branch pipe is prevented, and a counterclockwise swirling flow and a clockwise swirling occur to smoothly flow down the drainage. According to the drainage pipe joint of claim 5, in addition to the above-described effects, the drainage flowing into the pipe joint through the horizontal branch pipe on the upper stage side collides with the backflow preventing convex portion to the horizontal branch pipe on the lower stage side. The reverse flow is prevented, and the flow direction of the inflowing drainage changes to the flow toward the pipe center side of the pipe joint, whereby the drainage smoothly flows down.

According to the drainage pipe joint of the sixth aspect, since the backflow preventing portion is provided at the opening of the horizontal branch pipe receiving port on the lower stage side, the drainage flowing from the horizontal branch pipe on the upper stage side is on the lower stage side. Backflow to the side-branch receptacle is prevented. The lower side branch pipe receiving port is prepared separately from the downstream joint body, and is attached to the joint body when necessary, for example, when constructing the drainage pipe joint. The backflow prevention portion is provided at the lower lateral branch pipe receiving port. Therefore, if the lateral branch pipe receiving port is attached to the joint body of the lower joint on the downstream side, the backflow prevention portion can be made to function without performing any particular work on the backflow prevention portion. Regarding the above, it is possible to prevent the backflow of drainage to the lateral branch pipe receiving port on the downstream side without taking the trouble of construction. According to the drainage pipe joint of claim 7, in addition to the above-described effects, the drainage flown from the upper lateral branch pipe collides with the backflow prevention portion, so that the drainage flows leftward or rightward or the pipe center side. It can be drained smoothly. According to the drainage pipe joint of claim 8, since the lateral branch pipe receiving port can be surely attached to the joint main body at a correct position with respect to the position around the pipe axis, an attaching mistake by an operator can be avoided. The function of the backflow prevention unit can be reliably exerted.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a drainage pipe joint 1 of the first embodiment. The drainage pipe joint 1 is a so-called two-body pipe joint, and includes an upstream side upper joint 10 and a downstream side lower joint 20 which are connected to each other. The upper joint 10 includes an upper connecting portion 11 for connecting the upstream side standpipe 2 and a horizontal branch pipe receiving port 12 for connecting the upper side branch pipe 4. The lower joint 20 includes a lower connecting portion 21 for connecting the vertical pipe 3 on the downstream side and a horizontal branch pipe receiving port 22 for connecting the horizontal pipe 5 on the lower stage side.

The lower portion of the upper joint 10 is watertightly connected to the upper portion of the lower joint 20. In FIG. 1, the joint surface between the upper joint 10 and the lower joint 20 is indicated by an arrow L0. The standpipe 2 on the upstream side is connected to the upper connecting portion 1 via a packing (not shown).
1 is connected in a watertight manner. Further, the lower connecting portion 21 of the lower joint 20 is watertightly connected to the receiving port 3a of the vertical pipe 3 on the downstream side via a packing (not shown). In the present embodiment, the upper joint 10 and the lower joint 20 are connected so that the lateral branch pipe receiving port 22 is located on the opposite side of the lateral branch pipe receiving port 12 with respect to the position around the pipe axis. Further, the lateral branch pipe 4 connected to the upper joint 10 is connected to the lower joint 20.
Is arranged at a position one step lower than the horizontal branch pipe 5 connected to (the position where the height in the pipe axis direction is low), and the horizontal branch pipe 4 corresponds to the horizontal branch pipe on the upper stage side described in the claims. And branch pipe 5
Corresponds to the horizontal branch pipe on the lower stage side. The lateral branch pipe 4 is watertightly connected to the lateral branch pipe receiving port 12 of the upper joint 10 via a packing (not shown). The lateral branch pipe 4 is connected to a toilet bowl (not shown). Therefore, the toilet drainage flows into the drainage pipe joint 1 through the lateral branch pipe 4. The flow of waste water from the toilet bowl is indicated by the white arrow L1 in FIG.
Indicated by. The lateral branch pipe 5 is watertightly connected to the lateral branch pipe receiving port 22 of the lower joint 20 via a packing (not shown). So-called sewage from a kitchen sink or a bathtub in a bathroom flows into the lower joint 20 through the lateral branch pipe 5.

Next, a backflow preventing convex portion 30 is integrally formed on the inner wall surface of the lower joint 20. The backflow preventing convex portion 30 has an opening 22a on the pipe inner wall surface side of the lateral branch pipe receiving port 22.
It is provided on the upper side of the above and at a position where it is possible to prevent the backflow of the toilet drainage into the opening 22a. This backflow prevention convex portion 3
As shown in FIG. 2, 0 is formed so as to project inward of the pipe along the arcuate shape of the inner wall surface of the pipe, and has a substantially flat plate-shaped left inclined surface 30a. The left inclined surface 30a is inclined in a direction that descends to the left when viewed from the center side of the pipe (a direction that descends in a counterclockwise direction when seen in a plan view (the same applies in the direction of the arrow H in FIG. 1). Therefore, the backflow prevention convex portion 3
The toilet drainage that collides with the left-side inclined surface 30a of 0 is flown along the inner wall surface of the pipe while turning counterclockwise when viewed in plan. The flow of the toilet effluent at this stage is shown by a white arrow L2 in the figure. Further, the left inclined surface 30a is
It also inclines at a slight angle in the direction toward the center of the pipe.

Next, a taper pipe portion 20a is formed in the range of the downstream half of the lower joint 20, the taper pipe portion 20a being inclined in a direction in which the diameter becomes smaller toward the downstream side. A lower connecting portion 21 is continuously formed below the tapered pipe portion 20a. On the inner surface side of the taper pipe portion 20a, two turning guides 23,
24 are formed to face each other. Both turning guides 2
Similarly to the backflow preventing convex portion 30, the reference numerals 3 and 24 are also inclined in the counterclockwise downward direction. Further, the upper surfaces of the two turning guides 23 and 24 are also inclined at a slight angle toward the center of the pipe. Further, as shown in FIG. 3, with respect to the position of the lower joint 20 around the pipe axis, both the turning guides 23, 2
The positions of the two swivel guides 23 and 24 around the tube axis are set so that the backflow preventing convex portion 30 is located between the two.

According to the drainage pipe joint 1 of the first embodiment configured as described above, the toilet drainage flowing in from the horizontal branch pipe 4 on the upper stage side is provided with the backflow preventing projections arranged so as to face each other around the pipe axis. Collide with the unit 30. The backflow preventing convex portion 30 is formed in a protruding shape on the upper side of the opening portion 22a on the pipe inner wall surface side of the lateral branch pipe receiving port 22. Therefore, the backflow of the toilet drainage flowing in through the lateral branch pipe 4 to the opening 22a and thus the lateral branch pipe 5 is prevented. In addition, the backflow prevention convex portion 30 of the first embodiment.
Since it is formed integrally with the inner wall surface of the pipe, it is possible to omit the work of installing a separately prepared one between the upper joint and the lower joint at the time of construction as in the conventional construction. It is possible to improve work efficiency during construction.

Further, the left inclined surface 30 of the backflow preventing convex portion 30.
Since a is inclined in the counterclockwise downward direction when viewed two-dimensionally, the toilet bowl drainage that has collided with the backflow preventing convex portion 30 is swung along the pipe inner wall surface as shown by an arrow L2 in the figure. Therefore, the drainage can smoothly flow down. In addition, the backflow prevention convex portion 30 causes the water film of the toilet drainage flowing in from the upper side lateral branch pipe 4 and the vertical pipe drainage flowing in from the upstream side vertical pipe 2 to form the opening 2
Since 2a is prevented from being blocked, the miscellaneous wastewater from the lateral branch pipe 5 smoothly flows in, thereby suppressing the pressure fluctuation in the lateral branch pipe 5 and trapping water of various drainage devices. Breaking can be prevented. In addition, the backflow prevention convex portion 3
0 indicates both turning guides 23, 24 with respect to the position around the pipe axis.
It is located between the two, which also facilitates the smooth flow of toilet bowl drainage.

Various modifications can be added to the first embodiment described above. For example, the backflow prevention convex portion 30 has the left inclined surface 30a inclined only to the left side when viewed from the center side of the pipe, but instead, the backflow prevention convex portion 30 is bent in a substantially V shape as shown in FIG. The part 31 may be provided. The backflow preventing convex portion 31 includes a left inclined surface 31a that inclines to the left and a right inclined surface 31 that inclines to the right when viewed from the center side of the pipe.
b. Both the inclined surfaces 31a and 31b are also inclined toward the center of the pipe in a direction descending at a slight angle. Further, this backflow preventing convex portion 31 is similar to the backflow convex portion 30 in that it is integrally provided on the upper side of the opening 22a on the pipe inner wall surface side of the lateral branch pipe receiving port 22. The inverted V-shaped backflow preventing convex portion 31 prevents the toilet drainage that has flowed in through the upper side branch pipe 4 from flowing back into the lower side branch pipe 5 through the opening 22a. At the same time, the water films of the toilet bowl drainage and the vertical pipe drainage are branched leftward and rightward by the left and right inclined surfaces 31a and 31b to prevent the opening 22a from being blocked, thereby suppressing the pressure fluctuation in the lateral branch pipe 5. Therefore, it is possible to prevent breakage of trap sealing water of various drainage devices.

Further, in place of the backflow preventing projections 30 and 31, a backflow preventing projection 32 as shown in FIG. 5 may be used.
The backflow prevention convex portion 32 is also integrally formed on the upper side of the opening 22a on the inner wall surface side of the lateral branch pipe receiving port 22. Further, the upper surface 32a of the backflow prevention convex portion 32 has the left and right inclined surfaces 30a, 31a, 31b of the backflow prevention convex portions 30, 31.
Unlike the above, it does not incline along the inner wall surface of the tube, but it inclines downward at a slight angle to the tube center side like an eaves.
According to this backflow prevention convex portion 32, the toilet effluent drainage flowing from the upper side lateral branch pipe 4 collides and flows toward the pipe center side, and therefore flows back to the lower side lateral branch pipe 5 through the opening 22a. Is prevented.

Further, in the drainage pipe joint 1 of the first embodiment described above, the backflow preventing convex portion 30 is integrally provided on the inner peripheral surface of the lower joint 20, but it is separate from the lower joint. The backflow prevention unit 44 can also be used. In Figure 6,
The drainage pipe joint 40 of the second embodiment including the separate type backflow preventing convex portion 44 is shown. The drainage pipe joint 40 of the second embodiment is different from the first embodiment in the configuration of the lateral branch pipe receiving port 42 in the lower joint 41 on the downstream side, and other configurations and the configuration of the upper joint 10 are as described above. Since it is similar to the first embodiment, the same reference numerals are used and the description thereof is omitted. As shown in FIG. 6, the lateral branch pipe receiving port 42 in the lower joint 41 of the second embodiment is manufactured separately from the joint body 43. A mounting hole 43a for mounting the separate lateral branch pipe receiving port 42 is provided in the body portion of the joint body 43 corresponding to the position where the lateral branch pipe receiving port 22 in the first embodiment is provided. It is formed to penetrate. The lateral branch pipe receiving port 42 is attached to the side portion of the lower joint 41 through the mounting hole 43a.

FIG. 7 shows the lateral branch pipe receiving port 42 alone. The lateral branch pipe receiving port 42 includes a flange portion 42 a that abuts on the outer surface of the joint body 43. A boss portion 42b is formed on the inner surface side of the flange portion 42a (the side that contacts the outer surface of the joint body 43). The boss portion 42b is formed with a diameter that allows the boss portion 42b to be inserted into the mounting hole 43a of the joint body 43 with almost no gap. The end surface (flat surface on the inner side of the pipe) of the boss portion 42b is provided with an opening 42c on the pipe inner wall surface side through which the lateral branch pipe drainage flows. Further, a backflow preventing wall portion 44 is integrally formed on the end surface of the boss portion 42b so as to cover the upper half of the opening portion 42c. The backflow prevention wall portion 44 has a spherical shape obtained by dividing a hollow sphere into four equal parts, as shown in the figure, and has a boss portion 42.
It is provided so as to project inward of the pipe along the upper half circumference of b. A fitting portion 42d for positioning is provided on an upper portion on the inner surface side of the flange portion 42a so as to project to the outer surface side of the pipe joint. The fitting portion 42d is provided on the flange portion 4
When 2a is brought into contact with the outer surface of the joint body 43, the joint body 4
3 is fitted into a fitting recess (not shown) formed on the outer surface of the lateral branch pipe 42, and thus the flange portion 42a, and thus the position of the lateral branch pipe receiving port 42 with respect to the joint body 43, around the pipe axis of the lateral branch pipe receiving port 42 (described later). Around the pipe axis of the connecting pipe portion 47 to be positioned. The fitting portion 42d corresponds to one embodiment of the positioning means described in claim 8. In addition, in the four corners of the flange portion 42a,
An insertion hole for bolting is formed. The horizontal branch pipe receiving port 42 is fixed to the joint body 43 by tightening the bolts 45 inserted into the respective insertion holes 42e to 42e into the joint body 43.

Next, a connecting pipe portion 47 is formed on the outer surface side of the flange portion 42a (opposite to the boss portion 42b). The connecting pipe portion 47 communicates with the opening 42c. A cap nut 48 is attached to the rear end of the connecting pipe portion 47. The lateral branch pipe 5 is inserted into the connecting pipe portion 47 via the inner peripheral side of the cap nut 48, and when the cap nut 48 is tightened with respect to the connecting pipe portion 47 in this inserted state, the packing attached to the inner peripheral side thereof. Is pressed against the outer peripheral surface of the lateral branch pipe 5, and the lateral branch pipe 5 is water-tightly connected to the connecting pipe portion 47. The separate side branch pipe receiving port 42 configured as described above is attached to the lower joint 41 at the time of construction of the drainage pipe joint 40 or before and after the construction. The construction of the drainage pipe joint 40 is the upper joint 1
0 and the lower joint 41 are connected to each other and fixed to the concrete slab. Regarding the relative positions of the upper joint 10 and the lower joint 41 around the pipe axis, the upper branch side horizontal branch pipe receiving port 12 and the lower stage side horizontal branch pipe receiving port 42 are arranged.
The (mounting holes 43a) are connected to each other so as to face each other. When the lateral branch pipe receiving port 42 is attached to the joint body 43, the flange portion 42a is fixed to the joint body 43 with bolts 45 to 45 with the fitting portion 42d inserted in the fitting recess of the joint body 43. In this attached state, the packing 46 for preventing water leakage is sandwiched between the flange portion 42a and the outer surface of the joint body 43. Further, in this attached state, the boss portion 42b is attached to the joint body 4
The backflow prevention portion 44 is located above the opening 42c and shields the upper side of the opening 42c. Therefore, the drainage flowing from the lateral branch pipe 4 on the upper joint 10 side collides with the backflow prevention portion 44,
It is possible to prevent the drainage flowing from the upper stage side into the lateral branch pipe receiving port 42 on the lower joint 41 side and further to the lateral branch pipe 5 from flowing backward.

As described above, the backflow preventing portion 44 for preventing the drainage flowing from the upper side branch pipe 4 from flowing back to the lower side branch pipe 5 is different from the joint body 43 of the lower joint 41. Since it is provided integrally with the side branch pipe receiving port 42 prepared as a separate body, if the side branch pipe receiving port 42 is attached to the joint body 43, the backflow preventing portion 44 causes the backflow preventing portion 44 to It is located at a position that shields the upper side of the opening 42c), and thereby the backflow prevention function is achieved. From this, according to the drainage pipe joint 40 of the second embodiment, it is possible to prevent the backflow of the drainage of the horizontal branch pipe 5 on the lower stage side without taking special trouble for attaching the backflow prevention member as in the conventional case. You can Various modifications can be made to this second embodiment as well. For example, although the backflow prevention portion 44 corresponding to a shape obtained by dividing a hollow sphere into four has been illustrated, the split sphere shape of the backflow prevention portion may be a split sphere shape of three divisions or five or more divisions, if necessary. Further, as a connection method of the lateral branch pipe 5 to the connecting pipe portion 47 of the lateral branch pipe receiving port 42, a so-called cap nut type in which the lateral branch pipe 5 is water-tightly connected by tightening the cap nut 48 and pressing the packing is illustrated. However, instead of this, a flange portion is provided on the connection pipe portion 47 and the lateral branch pipe 5, and the flange portions are butted and connected by bolting, or a cylindrical packing is provided on the inner peripheral side of the connection pipe portion 47. It is also possible to use a so-called one-touch packing method in which the side branch pipe 5 is inserted and connected to the inner peripheral side of the packing.

Further, the construction in which the fitting portion 42d is provided as means for positioning the lateral branch pipe receiving port 42 in the joint main body 43 with respect to the position around the pipe axis is exemplified, but other various forms of positioning means are used. You can For example, as shown in FIG. 8, the end portion of the boss portion 42b is partially cut away to form a fitting portion 42f, and correspondingly, the fitting hole 42a on the joint body 43 side is extended to the inner peripheral side. By providing a projecting portion (not shown) for projecting, and engaging the fitting portion 42f with this projecting portion in the direction around the pipe axis of the lateral branch pipe receiving port 42, the lateral branch pipe receiving port is provided around the pipe axis. Regarding the position, the joint main body can be attached only at one place, and also with this constitution, it is possible to avoid the mistaken attachment by the operator and to surely exhibit the function of the backflow preventing portion. Further, by eccentricizing the positions of the insertion holes 42e to 42e for bolting with respect to the center of the boss portion 42b, the lateral branch pipe receiving port can be attached to the joint body 43 at only one position around the pipe axis. Since such a structure can be adopted, a similar positioning function can be obtained.

Further, the two-body type drain pipe joint 1 exemplified above.
In the above, the case where the lower side branch pipe receiving ports 22 and 42 are located on the opposite side of the upper side branch pipe receiving ports 12 (positions of 180 ° with respect to each other about the pipe axes of the vertical pipes 2 and 3) has been exemplified. Needless to say, the same can be applied to the case where the vertical tubes 2 and 3 are positioned at 90 ° with respect to each other about the tube axis or at other angles (for example, 45 °, 30 °, etc.). Here, as described above, in the case of the conventional two-body joint (when the backflow prevention convex portion according to the present invention is not provided), the side branch pipe for miscellaneous drainage is provided on the side opposite to the side branch pipe receiving port for draining the toilet bowl. When the receiving port is located, there arises a problem that the inflowing toilet flush flows back through the opposite side branch pipe receiving port into the miscellaneous drainage side branch pipe. In order to avoid this backflow problem, conventionally, for example, a concavo-convex fitting part is provided at the joint between the upper joint and the lower joint, and the lower horizontal branch pipe inlet is opposed to the upper horizontal pipe inlet at the time of construction. In order not to be erroneously installed in the side position, measures were taken such that the upper joint and the lower joint were connected only in a fixed relationship with respect to the relative position of the vertical pipe around the pipe axis. This measure has been particularly effective in that it is possible to prevent the construction from being redone when the lower joint is directly backfilled in the concrete slab. In addition, it was also effective in preventing construction errors when performing construction in which the lower joint was connected to the receiving port backfilled in the concrete slab. As described above, in the case of the conventional two-body type pipe joint, it is unavoidable to perform the construction in which the horizontal branch pipe receiving port on the lower stage side is located opposite to the horizontal branch pipe receiving port on the upper stage side, which is unavoidable. In this case, it was inevitable to employ the backflow prevention wall portion of the type interposed between the upper joint and the lower joint as described above, but by providing the backflow prevention convex portion according to the present invention, It saves construction work and avoids the problem of backflow when the horizontal branch pipe inlet on the lower stage is located on the opposite side of the horizontal branch pipe inlet on the upper stage side. The degree of freedom can be greatly increased.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment of the present invention and is a vertical cross-sectional view of a two-body type drain pipe joint.

FIG. 2 is a front view of the backflow preventing projection viewed from the tube center side.

FIG. 3 is a view taken in the direction of arrow H in FIG. 1, and is a plan view of the lower joint.

FIG. 4 is a front view of a backflow preventing convex portion according to another embodiment.

FIG. 5 is a front view of a backflow preventing convex portion according to another embodiment.

FIG. 6 is a view showing a second embodiment of the present invention and is a vertical cross-sectional view of a two-piece drain pipe joint.

FIG. 7 is a view showing the second embodiment of the present invention, and is a perspective view of the horizontal branch pipe receiving port on the lower stage side in a state of being removed from the joint body.

FIG. 8 is a view showing a positioning means in another form for positioning the lateral branch pipe receiving port around the pipe body with respect to the joint body, and is a perspective view of the lower lateral branch pipe receiving port removed from the joint body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Two-body type drain pipe joint (1st Embodiment) 2 ... Upstream side stand pipe 3, ... Downstream side stand pipe 4 ... Upper stage side branch pipe 5 ... Lower stage side branch pipe 10 ... Upper joint 12 ... Horizontal branch pipe receiving port 20 ... Lower joint, 20a ... Tapered pipe part 22 ... Horizontal branch pipe receiving port, 22a ... Opening part on pipe inner wall side (miscellaneous drainage inflow port) 23, 24 ... Swirling guide 30 ... Backflow prevention convex part (tilt to the left) Shape), 30a ... Left sloping surface 31 ... Backflow preventing convex portion (diversion type), 31a ... Left sloping surface, 3
1b ... Right inclined surface 32 ... Backflow preventing convex portion (overhanging shape), 32a ... Upper surface L0 ... Joining surface L1 of upper joint and lower joint ... Horizontal side branch pipe drainage flow (toilet bowl drainage) L2 ... Along pipe inner wall surface Side branch pipe drainage flow 40 ... Two-body type drain pipe joint (second embodiment) 41 ... Lower joint 42 ... Side branch pipe receiving port, 42d, 42f ... Fitting portion (positioning means) 43 ... Joint body 44 ... Backflow Prevention part (split sphere shape)

Claims (8)

[Claims] 1. An upstream upper joint and a downstream lower joint that are connected to each other are provided, and the upper joint includes an upper connecting portion for connecting an upstream stand pipe and an upper horizontal branch pipe. The lower joint is provided with a horizontal branch pipe receiving port for connecting, and the lower joint is provided with a lower connecting part for connecting the downstream stand pipe and a horizontal branch pipe receiving port for connecting the lower side horizontal branch pipe. In order to prevent the drainage flowing from the horizontal branch pipe on the upper stage side from flowing back to the horizontal branch pipe on the lower stage side in the inner peripheral surface of the upper branch of the opening on the pipe inner wall surface side of the horizontal branch pipe receiving port. Of the backflow prevention convex portion is provided integrally with the pipe by projecting inwardly of the pipe.
A drainage pipe joint provided with an inclined surface for changing the flow of drainage flowing from the upper lateral pipe into a flow along the inner wall surface of the pipe. 2. The drainage pipe joint according to claim 1, wherein the lower joint has a taper pipe portion having a diameter that becomes smaller toward the downstream side, and the drainage flowing down to the inner surface of the taper pipe portion is around the pipe axis. Swirl guides for giving swirl flow are provided facing each other,
A drainage pipe joint in which the positions of the two swivel guides around the pipe axis are set to positions where the backflow preventing convex portions are located between the two swivel guides. 3. The drainage pipe joint according to claim 1, wherein the backflow preventing convex portion has an inclined surface for bending the drainage to the left in the downflow direction when viewed from the pipe center side. 4. The drainage pipe joint according to claim 1 or 2, wherein the backflow preventing convex portion has an inclined surface for branching the drainage to the left and right sides in the downflow direction when viewed from the pipe center side. 5. An upstream-side upper joint and a downstream-side lower joint that are connected to each other are provided, and the upper joint includes an upper-side connecting portion for connecting the upstream side standpipe and an upper-stage side branch pipe. The lower joint is provided with a horizontal branch pipe receiving port for connecting, and the lower joint is provided with a lower connecting part for connecting the downstream stand pipe and a horizontal branch pipe receiving port for connecting the lower side horizontal branch pipe. Of the inner peripheral surface of the horizontal branch pipe, the inclined surface for changing the flow of the drainage flowing from the horizontal branch pipe on the upper stage side toward the center of the pipe at the upper part of the opening on the pipe inner wall surface side of the horizontal branch pipe receiving port. Drainage pipe joint that is integrally provided with a backflow prevention convex portion having. 6. An upstream-side upper joint and a downstream-side lower joint that are connected to each other are provided, and the upper joint includes an upper-side connecting portion for connecting the upstream side standpipe and an upper-stage side branch pipe. A lower branch joint is provided with a lateral branch pipe receiving port for connecting, and a joint body having a lower connecting portion for connecting the downstream stand pipe,
A horizontal branch pipe receiving port which is prepared separately from the joint main body and which is attached to the joint main body to connect the horizontal branch pipe on the lower stage side when necessary is provided. Drainage provided above the opening on the inner wall surface side of the pipe to prevent backflow of the drainage flowing from the horizontal branch pipe on the upper stage side to the horizontal branch pipe receiving port on the lower stage side through the opening. Pipe fittings. 7. The drainage pipe joint according to claim 6, wherein the backflow prevention portion has a split sphere shape obtained by dividing a hollow sphere into four parts. 8. The drainage pipe joint according to claim 6 or 7, wherein the lateral branch pipe receiving port is provided with a means for positioning the position around the pipe axis with respect to the joint body.