Inner sub-pipe joint

Abstract

To provide an inner auxiliary pipe joint capable of further securing a working space in a manhole.SOLUTION: The inner sub-pipe joint 1 has a cylindrical vertical pipe part 11 extending in the vertical direction on the front surface side, and the width dimension of the upper part of the vertical pipe part 11 is formed longer than the depth dimension, so that the volume in the vertical pipe part 11 into which drainage flows from the drain pipe 3 is sufficiently secured. Since the lateral size of the lower part of the vertical pipe part 11 is gradually narrowed toward the lower drain outlet side 13a to form the drain outlet side 13a short in both the lateral direction and the depth direction, a pipe having a diameter smaller than that of the vertical pipe part 11 can be installed in a position near the internal wall of the manhole 2, and a working space in the manhole 2 can be further secured.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an internal secondary pipe joint to be installed in a manhole. [Background technology]

[0002] Conventionally, in manholes into which wastewater flows, if there is a large difference in the drop of the wastewater from the inlet pipe on the inflow side to the bottom of the manhole, an internal secondary pipe is sometimes installed on the inner wall of the manhole. The internal secondary pipe consists of an internal secondary pipe joint that changes the flow direction of the wastewater downward, and a secondary pipe that is connected to this internal secondary pipe joint and guides the wastewater downward, and by discharging the wastewater from near the bottom of the manhole, there is one that prevents the wastewater flowing into the manhole from scattering, eroding the bottom of the manhole, making noise, etc. (See, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-30162 Summary of the Invention [Problem to be solved by the invention]

[0004] The internal secondary pipe described in Patent Document 1 is installed so as to protrude into the inside of the manhole, narrowing the working space inside the manhole. On the other hand, the amount of wastewater flowing from the inlet pipe into the internal secondary pipe may temporarily increase, but this condition does not continue. If the internal secondary pipe fitting has a certain capacity that takes this inflow amount into account, sufficient drainage can be achieved even if the diameter of the secondary pipe is smaller than that of the inlet pipe. Therefore, by making the diameter of the secondary pipe smaller than that of the inlet pipe, working space inside the manhole can be secured.

[0005] However, in the case of an internal secondary pipe fitting having a circular cross-sectional shape as in Patent Document 1, if the diameter is reduced to match the diameter of the secondary pipe connected to the outlet of the internal secondary pipe fitting while taking into consideration the amount of wastewater flowing in from the inlet pipe, the secondary pipe will have a smaller diameter, and although working space inside the manhole can be secured, the space created between the secondary pipe and the inner wall of the manhole will be wasted, and the space created by the secondary pipe having a smaller diameter cannot be fully utilized.

[0006] The present invention has been made in view of these problems, and has an object to provide an internal secondary pipe joint that can secure more working space inside a manhole. [Means for solving the problem]

[0007] In order to solve the above problems, the internal sub-pipe joint of claim 1 of the present invention comprises: An internal pipe joint to be installed on the inner wall of a manhole, an inlet into which wastewater flows from the inlet pipe; A vertical pipe portion that allows the wastewater flowing in from the inlet to flow out from a lower outlet; Equipped with The upper portion of the vertical pipe portion is formed so that the width dimension along the circumferential direction of the inner wall of the manhole is longer than the depth dimension extending inwardly of the inner wall of the manhole, The width of the lower portion of the vertical pipe portion is gradually narrowed toward the outlet port. It is characterized by the following. According to this feature, the width dimension of the upper part of the vertical pipe section along the circumferential direction of the inner wall of the manhole is longer than the depth dimension extending inside the manhole, thereby ensuring sufficient volume within the vertical pipe section into which wastewater flows from the inlet pipe, and the width dimension of the lower part of the vertical pipe section is gradually narrowed toward the outlet below, forming an outlet that is short in both the width and depth directions.This means that a pipe with a smaller diameter than the vertical pipe section can be installed closer to the inner wall of the manhole, ensuring more working space within the manhole.

[0008] The internal sub-pipe joint of claim 2 of the present invention is the internal sub-pipe joint of claim 1, An inspection port is formed in the vertical pipe portion at a position opposite the inlet, The inspection hatch has an inner diameter larger than the inner diameter of the inlet pipe. It is characterized by the following. According to this feature, the inspection hatch is larger than the inner diameter of the inlet pipe, so that the inside of the inlet pipe can be seen widely from the inspection hatch.

[0009] The internal sub-pipe joint of claim 3 of the present invention is the internal sub-pipe joint according to claim 1 or 2, a mounting portion for mounting the vertical pipe portion to an inner wall of the manhole; A spacer corresponding to the shape of the inner wall of the manhole can be attached to the attachment portion. It is characterized by the following. According to this feature, by attaching a spacer that corresponds to the inner wall shape of the manhole to the attachment part, it becomes possible to install a common inner secondary pipe joint in manholes having different inner wall shapes. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cutaway perspective view of a manhole in which an internal secondary pipe joint according to an embodiment of the present invention is installed. [Figure 2] FIG. 2 is an external perspective view of the inner sub-pipe joint of the present embodiment. [Figure 3] FIG. 2 is an exploded perspective view of the inner sub-pipe joint of the present embodiment. [Figure 4] 1(a) to 1(e) are a front view, a side view, a top view, a back view, and a bottom view of the joint body, respectively. [Figure 5] FIG. 4(b) is a cross-sectional view taken along the line AA in FIG. [Figure 6] 4(a) is a partially cutaway perspective view of the joint body, and FIG. 4(b) is a cross-sectional view taken along line BB in FIG. 4(d). [Figure 7] 10(a) to 10(f) are a front view, a side view, a cross-sectional view taken along the line CC in 10(a), a top view, a back view, and a bottom view of the spacer, respectively. [Figure 8] 10(a) to 10(d) are top views of the internal secondary pipe fitting installed on the inner wall of a manhole. [Figure 9] 10(a) and 10(b) are diagrams showing the installation state of an internal secondary pipe joint to a drainage pipe connected by a flexible joint attached to the inner wall of a manhole. [Figure 10] FIG. 10 is a diagram showing the installation of an internal secondary pipe joint to a drainage pipe connected by a flexible joint attached to the outer wall of a manhole. [Figure 11] 10(a) and 10(b) are cross-sectional views showing the state in which the internal secondary pipe joint is installed in a manhole. [Figure 12] 10(a) to 10(c) are diagrams showing an internal sub-pipe joint in a first modified example. [Figure 13] 10(a) and 10(b) are diagrams showing an internal sub-pipe joint in Modification 2. FIG. [Figure 14] 10(a) to 10(c) are diagrams showing an internal sub-pipe joint in a third modified example. [Figure 15] 10(a) and 10(b) are diagrams showing an internal sub-pipe joint in Modification 4. FIG. [Figure 16] FIG. 10(a) is a diagram showing a recessed portion, and FIG. 10(b) is a diagram showing a modified example of the recessed portion. [Figure 17] 10(a) to 10(c) are diagrams showing modified examples of the spacer. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Form 1] Conventionally, in manholes into which wastewater flows, if there is a large difference in the drop of the wastewater from the inlet pipe on the inflow side to the bottom of the manhole, an internal secondary pipe may be installed on the inside wall of the manhole. The internal secondary pipe consists of an internal secondary pipe joint that changes the flow direction of the wastewater downward, and a secondary pipe connected to this internal secondary pipe joint that guides the wastewater downward. By discharging the wastewater from near the bottom of the manhole, some internal secondary pipes are designed to prevent the wastewater flowing into the manhole from scattering, eroding the bottom of the manhole, making noise, etc. (For example, see JP 2005-30162 A).

[0012] Because such internal secondary pipes are installed protruding into the inside of the manhole, the working space inside the manhole becomes narrow. On the other hand, the amount of wastewater flowing from the inlet pipe into the internal secondary pipe may temporarily increase, but this condition does not continue. If the internal secondary pipe fitting has a certain capacity that takes this inflow amount into account, sufficient drainage can be achieved even if the diameter of the secondary pipe is smaller than that of the inlet pipe. Therefore, by making the diameter of the secondary pipe smaller than that of the inlet pipe, working space inside the manhole can be secured.

[0013] However, in the case of an internal secondary pipe fitting having a circular cross section as in Patent Publication No. 2005-30162, if the diameter is reduced to match the diameter of the secondary pipe connected to the outlet of the internal secondary pipe fitting while taking into consideration the amount of wastewater flowing in from the inlet pipe, the working space inside the manhole can be secured since the diameter of the secondary pipe becomes smaller, but the space created between the secondary pipe and the inner wall of the manhole is wasted, and the space created by the smaller diameter of the secondary pipe cannot be fully utilized.

[0014] In contrast, the internal pipe joint of type 1 is An internal pipe joint to be installed on the inner wall of a manhole, an inlet into which wastewater flows from the inlet pipe; A vertical pipe portion that allows the wastewater flowing in from the inlet to flow out from a lower outlet; Equipped with The upper portion of the vertical pipe portion is formed so that the width dimension along the circumferential direction of the inner wall of the manhole is longer than the depth dimension extending inwardly of the inner wall of the manhole, The width of the lower portion of the vertical pipe portion is gradually narrowed toward the outlet port. It is characterized by the following. According to this feature, the width dimension of the upper part of the vertical pipe section along the circumferential direction of the inner wall of the manhole is longer than the depth dimension extending inside the manhole, thereby ensuring sufficient volume within the vertical pipe section into which wastewater flows from the inlet pipe, and the width dimension of the lower part of the vertical pipe section is gradually narrowed toward the outlet below, forming an outlet that is short in both the width and depth directions.This means that a pipe with a smaller diameter than the vertical pipe section can be installed closer to the inner wall of the manhole, ensuring more working space within the manhole.

[0015] [Form 2] The internal sub-pipe joint of form 2 is the internal sub-pipe joint according to form 1, The depth dimension of the lower portion of the vertical pipe portion does not change toward the outlet. It is characterized by According to this feature, the width dimension of the lower part of the vertical pipe section is gradually narrowed toward the outlet, while the depth dimension does not change toward the outlet, so the shape of the lower part of the vertical pipe section does not become complex.

[0016] [Form 3] The internal sub-pipe joint of form 3 is the internal sub-pipe joint according to form 1 or 2, The lower part of the vertical pipe portion has a generally elliptical cross section in which the width dimension is greater than the depth dimension, and the width dimension gradually narrows toward the outlet port having a generally circular cross section in which the width dimension and the depth dimension are generally the same. It is characterized by According to this feature, the width of the lower part of the vertical pipe gradually narrows from the generally elliptical cross section toward the outlet with a generally circular cross section, which allows for a smooth flow of wastewater.

[0017] [Form 4] The internal pipe joint of form 4 is the internal pipe joint according to any one of forms 1 to 3, The width of the lower portion of the vertical pipe portion is gradually narrowed from a position below the lowest end of the inlet toward the outlet. It is characterized by the following. According to this feature, the width dimension of the lower part of the vertical pipe section is gradually narrowed from a position below the lowest point of the inlet towards the outlet, and the vertical volume of the vertical pipe section can be sufficiently secured, so that even if the amount of wastewater flowing into the inlet temporarily increases, it can be discharged to the outlet with ease.

[0018] [Form 5] The internal sub-pipe joint of aspect 5 is the internal sub-pipe joint according to any one of aspects 1 to 4, An upper inspection port is formed on the upper surface of the vertical pipe portion, The upper inspection hatch is formed so that the width dimension is longer than the depth dimension. It is characterized by the following. According to this feature, the upper inspection hatch is formed so that its width dimension is longer than its depth dimension, just like the upper part of the vertical pipe section, thereby minimizing blind spots within the vertical pipe section from the upper inspection hatch.

[0019] [Form 6] The internal pipe joint of aspect 6 is the internal pipe joint according to any one of aspects 1 to 5, The vertical pipe portion is a first vertical pipe portion that constitutes an upper portion of the vertical pipe portion; a second vertical pipe portion that forms a lower portion of the vertical pipe portion and is connected to a lower portion of the first vertical pipe portion; Equipped with It is characterized by the following. According to this feature, the second vertical pipe section can be connected below the first vertical pipe section and connected to a pipe having a width dimension shorter than that of the first vertical pipe section, or the second vertical pipe section can be not connected and the first vertical pipe section can be connected below to a pipe having a width dimension equal to that of the first vertical pipe section.

[0020] [Form 7] Conventionally, in manholes into which wastewater flows, if there is a large difference in the drop of the wastewater from the inlet pipe on the inflow side to the bottom of the manhole, an internal secondary pipe may be installed on the inside wall of the manhole. The internal secondary pipe consists of an internal secondary pipe joint that changes the flow direction of the wastewater downward, and a secondary pipe connected to this internal secondary pipe joint that guides the wastewater downward. By discharging the wastewater from near the bottom of the manhole, some internal secondary pipes are designed to prevent the wastewater flowing into the manhole from scattering, eroding the bottom of the manhole, making noise, etc. (For example, see JP 2005-30162 A).

[0021] The internal secondary pipe fittings that make up such internal secondary pipes are bent in an L-shape when viewed from the side, and change the direction of wastewater flowing in from the side so that it flows downward.As a result, the wastewater may become stagnant in the bent pipe, and there is a risk that the drainage performance will be affected by impurities and transported materials contained in the stagnant wastewater.

[0022] In contrast, the internal pipe joint of form 7 is An internal pipe joint to be installed on the inner wall of a manhole, an inlet into which wastewater flows from the inlet pipe; A vertical pipe portion that allows the wastewater flowing in from the inlet to flow out from a lower outlet; an extension pipe portion extending from the vertical pipe portion to the inlet; Equipped with A recessed portion extending into the vertical pipe portion is formed on the inner peripheral bottom surface of the extending pipe portion. It is characterized by the following. According to this feature, a recess extending into the vertical pipe section is formed on the inner bottom surface of the extension pipe section extending from the vertical pipe section to the inlet.Therefore, by allowing the wastewater that flows into the extension pipe section to flow out into the vertical pipe section through the recess, it is possible to prevent the wastewater from stagnating in the extension pipe section, thereby suppressing the impact on drainage performance caused by impurities and transported materials contained in the stagnant wastewater.

[0023] [Form 8] The internal sub-pipe joint of form 8 is the internal sub-pipe joint according to form 7, The recessed portion has a bottom surface that gradually becomes steeper from the extending pipe portion toward the inside of the vertical pipe portion. It is characterized by the following. According to this feature, the wastewater that has flowed into the recessed portion can be smoothly discharged.

[0024] [Form 9] The internal sub-pipe joint of aspect 9 is the internal sub-pipe joint according to any one of aspects 1 to 8, An inspection port is formed in the vertical pipe portion at a position opposite the inlet, The inspection hatch has an inner diameter larger than the inner diameter of the inlet pipe. It is characterized by the following. According to this feature, the inspection hatch is larger than the inner diameter of the inlet pipe, so that the inside of the inlet pipe can be seen widely from the inspection hatch.

[0025] [Form 10] The internal sub-pipe joint of aspect 10 is the internal sub-pipe joint according to any one of aspects 1 to 9, A gripping portion capable of gripping the internal secondary pipe joint is provided. It is characterized by the following. According to this feature, by gripping the grip portion of the internal secondary pipe joint, the internal secondary pipe joint can be placed in the manhole in a stable state.

[0026] [Form 11] The internal sub-pipe joint of aspect 11 is the internal sub-pipe joint according to any one of aspects 1 to 10, The outlet is formed with a receiving port having a mechanism for preventing the pipe inserted from below from falling out. It is characterized by the following. This feature allows for easy connection of a pipe to the outlet.

[0027] [Form 12] The internal sub-pipe joint of aspect 12 is the internal sub-pipe joint according to any one of aspects 1 to 11, a mounting portion for mounting the vertical pipe portion to an inner wall of the manhole; The mounting portion is formed with a mounting hole through which a mounting member can be inserted and a temporary fastening hole for temporarily fastening the mounting member to the inner wall of the manhole. It is characterized by the following. According to this feature, after the internal secondary pipe joint has been positioned by temporarily fastening it using the temporary fastening hole, the mounting portion can be attached to the inner wall of the manhole using the mounting member.

[0028] [Form 13] The internal sub-pipe joint of aspect 13 is the internal sub-pipe joint according to any one of aspects 1 to 12, a mounting portion for mounting the vertical pipe portion to an inner wall of the manhole; The mounting portion is formed with an indicator portion that indicates the center position of the inlet. It is characterized by the following. According to this feature, when installing the device on the inner wall of a manhole, the worker can check the center position of the inlet, which is not visible from the worker's side.

[0029] [Form 14] The internal sub-pipe joint of aspect 14 is the internal sub-pipe joint according to any one of aspects 1 to 13, a mounting portion for mounting the vertical pipe portion to an inner wall of the manhole; A spacer corresponding to the shape of the inner wall of the manhole can be attached to the attachment portion. It is characterized by the following. According to this feature, by attaching a spacer that corresponds to the inner wall shape of the manhole to the attachment part, it becomes possible to install a common inner secondary pipe joint in manholes having different inner wall shapes.

[0030] [Form 15] The internal sub-pipe joint of aspect 15 is the internal sub-pipe joint according to aspect 14, the spacer includes a locking portion that locks the mounting portion, The spacer is capable of being installed on the inner wall of the manhole in a state where the mounting portion is engaged with the engaging portion and the spacer is integrated with the mounting portion. It is characterized by the following. According to this feature, the spacer and the mounting portion can be installed in an integrated state on the inner wall of the manhole, so that the internal secondary pipe joint can be installed efficiently.

[0031] [Form 16] The internal sub-pipe joint of aspect 16 is the internal sub-pipe joint according to aspect 14 or 15, The spacer is separable It is characterized by the following. According to this feature, even if the entrance of the manhole is narrow, the spacer can be easily brought inside by dividing it.

[0032] [Form 17] The internal sub-pipe joint of aspect 17 is the internal sub-pipe joint according to any one of aspects 14 to 16, The spacer is made of a flexible material. It is characterized by the following. According to this feature, even if the entrance of the manhole is narrow, the spacer can be easily bent to bring it inside.

[0033] [Form 18] The internal sub-pipe joint of aspect 18 is the internal sub-pipe joint according to any one of aspects 14 to 17, The mounting portion is formed with a temporary fastening hole for temporarily fastening to the inner wall of the manhole, The spacer has temporary fastening holes formed at positions corresponding to the temporary fastening holes of the mounting portion. It is characterized by the following. According to this feature, even when the internal secondary pipe joint is attached via a spacer, the internal secondary pipe joint can be temporarily fixed by utilizing the temporary fixing hole.

[0034] [Form 19] The internal sub-pipe joint of aspect 19 is the internal sub-pipe joint according to any one of aspects 14 to 18, a first annular recess and a second annular recess located outside the first recess are formed on a surface of the spacer that is installed on the inner wall of the manhole; When the manhole is installed on the inner wall, a soft material is placed in one of the first recess and the second recess. It is characterized by the following. According to this feature, one of the recesses is sealed by disposing a soft material in it, and the spacer can be made lighter by providing a recess that is not used for sealing.

[0035] [Form 20] The internal sub-pipe joint of aspect 20 is the internal sub-pipe joint according to any one of aspects 14 to 19, The spacer is formed with a fitting portion into which a part of a flexible joint that connects the inlet pipe to the inner wall of the manhole can be fitted. It is characterized by the following. According to this feature, by fitting a part of the flexible joint into the fitting portion of the spacer, the spacer can be installed with the thickness of the flexible joint relieved inside the fitting portion.

[0036] Hereinafter, an embodiment of the internal pipe joint according to the present invention will be described based on an example. [Example]

[0037] Fig. 1 is a cutaway perspective view of a manhole in which an internal secondary pipe fitting of this embodiment is installed. As shown in Fig. 1, the internal secondary pipe fitting 1 of this embodiment is installed in a manhole 2 buried below the ground surface as a sewerage relay facility. It redirects the flow of wastewater flowing in from a drainage pipe 3 connected to the upper side of the manhole 2 downward and guides it through a straight pipe 4 and / or a curved pipe 5 connected below the internal secondary pipe fitting 1 to an inverted section 9 formed at the bottom of the manhole 2, as described below, to prevent the wastewater from scattering, erosion, noise, etc. The internal secondary pipe fitting 1 and the straight pipe 4 and / or the curved pipe 5 constitute an internal secondary pipe.

[0038] [About manholes] Manhole 2 is a concrete structure, and as shown in Figure 1, its thin cylindrical body is buried vertically underground. The upper part of manhole 2's body is formed in a conical shape (not shown) that tapers upward, and an opening 6 is provided at its upper end. A disk-shaped cover 7 that allows opening 6 to be opened and closed is removably attached to opening 6, and cover 7 is fitted into opening 6 with its upper surface aligned with the ground surface. At the inner bottom of manhole 2, an inverted section 9 with a roughly semicircular cross section is formed, sloping toward a drainage pipe 8 connected to the lower side of manhole 2.

[0039] [About internal sub-pipe fittings] Fig. 2 is an external perspective view of the internal sub-pipe fitting of this embodiment, and Fig. 3 is an exploded perspective view of the internal sub-pipe fitting of this embodiment. As shown in Figs. 2 and 3, the internal sub-pipe fitting 1 is composed of a fitting body 10 and a spacer 30.

[0040] [About the fitting body] 4(a) to 4(e) are a front view, a side view, a top view, a back view, and a bottom view of the joint body 10, respectively, FIG. 5 is a cross-sectional view taken along line AA in FIG. 4(b), FIG. 6(a) is a partially cutaway perspective view of the joint body, and FIG. 6(b) is a cross-sectional view taken along line BB in FIG. 4(d).

[0041] The fitting body 10 is integrally molded from a synthetic resin such as polyvinyl chloride. At one end of the fitting body 10 (hereinafter, the side facing the center of the manhole 2 when the internal pipe fitting 1 is installed in the manhole 2 will be referred to as the one end, and the side facing the outer wall of the manhole 2 when the internal pipe fitting 1 is installed in the manhole 2 will be referred to as the other end), a cylindrical vertical pipe section 11 extending in the vertical direction is formed, as shown in FIGS. 2 to 6 . The upper portion 11a of the vertical pipe section 11 (see FIGS. 4 and 6 ) has a width dimension (the dimension along the circumferential direction of the inner wall of the manhole 2) greater than a depth dimension (the dimension extending toward the inner diameter of the manhole 2), and is formed with a generally elliptical cross section whose width and depth dimensions do not change from the upper end to the lower end. The upper end is open, forming an upper inspection hatch 12. The width dimension of the upper portion 11a of the vertical pipe section 11 is greater than the outer diameter of the drainage pipe 3, and its depth dimension is smaller than the outer diameter of the drainage pipe 3. The shape of the upper inspection hatch 12 is the same as the cross-sectional shape of the upper portion 11a of the vertical pipe portion 11, and is a substantially elliptical shape with a width dimension greater than a depth dimension.

[0042] As shown in Figures 2 to 6, the lower part 11b of the vertical pipe section 11 (see Figures 4 and 6) has an upper end that is the same shape as the cross-sectional shape of the upper part 11a of the vertical pipe section 11, i.e., an approximately elliptical shape with a width dimension greater than a depth dimension, and is tapered so that the width dimension gradually narrows downward from a position below the lower end part 19U of the wastewater inlet 19 described later, while the depth dimension remains the same and does not change downward, and the width and depth dimensions of the lower end of the lower part 11b of the vertical pipe section 11 are reduced in diameter to a circular cross-section that is smaller than the outer diameter of the drainage pipe 3.

[0043] As shown in Figures 2 to 6, a secondary pipe connection section 13 is formed below the vertical pipe section 11, continuing from the lower part 11b of the vertical pipe section 11. As shown in Figures 5 and 6(b), a drainage outlet 13a having approximately the same size as the outer diameter of the insertion opening of the straight pipe 4 or curved pipe 5 opens at the lower end of the secondary pipe connection section 13, and an annular groove 13c is formed on the inner surface of the secondary pipe connection section 13 into which a water stop ring 13b made of a soft material such as rubber is fitted. An annular ridge 13d that protrudes upward and inward is formed on the water stop ring 13b, and the ridge 13d prevents the straight pipe 4 or curved pipe 5 inserted into the secondary pipe connection section 13 from below from being pulled out downward. In addition, the secondary pipe connection portion 13 has an expanded diameter portion 13e formed therein, which expands in diameter upward from the groove portion 13c, i.e., expands in a tapered manner in the opposite direction to the opening (wastewater outlet 13a) of the secondary pipe connection portion 13, so that even after the insertion opening of the straight pipe 4 or curved pipe 5 is inserted into the secondary pipe connection portion 13, the insertion angle of the straight pipe 4 or curved pipe 5 can be adjusted within the range of the inner diameter of the expanded diameter portion 13e.

[0044] As shown in Figure 3, the fitting body 10 has an inspection hatch 14 that opens at one end of the vertical pipe 11 and extends toward that end, with an inspection hatch 14a opening at the end of the inspection hatch 14. The inner diameter of the inspection hatch 14a is larger than the inner diameter of the drain pipe 3 that is connected to the internal secondary pipe fitting 1, as shown in Figure 9(b). The inspection hatch 14a can be closed with an inspection hatch cover 15.

[0045] The inspection hatch cover 15 is molded from a synthetic resin such as polyvinyl chloride, and as shown in Figure 3, one end has a flange portion 15a with a larger diameter than the inspection hatch 14a, and the other end has a protrusion 15b that fits into the inspection hatch portion 14 to close the inspection hatch 14a, and a ring-shaped recess (not shown) is formed around the protrusion 15b, and a water-stop ring 15c made of a soft material such as rubber is attached to it.

[0046] As shown in Figures 2 and 3, the inspection hatch cover 15 has a locking groove 15d formed in the vertical direction, and locking portions 16, 16 are formed at the upper and lower positions of the inspection hatch portion 14, respectively, which protrude outward and have locking holes 16a that penetrate in the vertical direction.When the inspection hatch 14a is blocked by the inspection hatch cover 15, a locking pin 17 is inserted from above into the locking holes 16a of the locking portions 16, 16, and the opening of the inspection hatch cover 15 is restricted by the locking pin 17 locked in the locking groove 15d.

[0047] As shown in Figures 2 to 4 and 6, the joint body 10 is formed with a short-tube-shaped extension pipe section 18 that opens at the other end of the vertical pipe section 11, extends toward the other end, and has a wastewater inlet 19 opening inside an attachment section 21, which will be described later. The inner circumferential surface of the extension pipe section 18 expands slightly in diameter over its entire circumference from the vertical pipe section 11 at one end toward the wastewater inlet 19 at the other end. In addition, a recessed portion 20 is formed in the inner circumferential bottom surface of the extension pipe section 18, i.e., in a portion of the central area of ​​the lower half or less of the inner circumferential surface of the extension pipe section 18, as shown in Figures 5 and 6(a) and (b). The recessed portion 20 is cut out so as to extend at an angle downward toward the inner circumferential surface 11c of the vertical pipe section 11. As shown in FIG. 6(b), the bottom surface of the recess 20 is formed in a substantially arc shape with an inclination angle θ of the bottom surface gradually becoming steeper from the extended pipe portion 18 toward the inner peripheral surface 11c of the vertical pipe portion 11.

[0048] As shown in Figures 2 to 6, a substantially rectangular mounting portion 21 is formed on the other end of the joint body 10, with a wastewater inlet 19 opening on the inside. As shown in Figures 4(c) and (e), the mounting portion 21 has a curved mounting surface 21a with a curvature that follows the inner circumferential surface of the No. 1 manhole a2 (see Figure 8(a)). Furthermore, the mounting portion 21 has insertion holes 22 formed at its four corners that penetrate in the front-rear direction for mounting members such as fixing bolts B. The insertion holes 22 are elongated holes that extend from the center of the mounting portion 21 toward the four corners of the outer edge. Furthermore, a temporary fastening portion 23 that protrudes upward is formed on the upper side of the mounting portion 21, and a temporary fastening hole 23a that penetrates in the front-rear direction is formed in the temporary fastening portion 23. Also, as shown in Figure 5, indicator protrusions 24a, 24a are formed on both the left and right ends of the mounting portion 21 at positions where the horizontal center line C1 of the wastewater inlet 19 passes, and an indicator protrusion 24b is formed on the upper end of the temporary fixing portion 23 at a position where the vertical center line C2 of the wastewater inlet 19 passes.

[0049] As shown in Figures 4(a) and 6(a) and (b), the mounting surface 21a of the mounting portion 21 has a notch 21b formed in a circular shape around the drainage inlet 19. The notch 21b has an inner diameter that allows a flange portion 40b of a flexible joint 40 (described below) that connects the drainage pipe 3 to the manhole 2 to be fitted therein. An annular groove 21c is formed on the mounting surface 21a outside the notch 21b, and an annular groove 21d is further formed outside the groove 21c. An annular watertight gasket P (see Figure 9(b)) is attached to the groove 21d. Note that when the spacer 30 is used for attachment to the manhole 2, the watertight gasket P is not attached. The groove 21c is intended to reduce the weight of the fitting body 10 and the amount of material used. Furthermore, the portions that define these grooves 21c and 21d act as ribs to increase the structural strength of the attachment portion 21 and stabilize its shape.

[0050] As shown in Figures 2 to 4, on both sides of the joint body 10, gripping portions 25, 25 are formed that are inclined diagonally upward from the mounting portion 21 to the side surface of the vertical pipe portion 11 toward one end, making it possible to grip the joint body 10 from both sides.

[0051] [About spacers] Figures 7(a) to (f) are respectively a front view, a side view, a CC cross-sectional view of (a), a top view, a back view, and a bottom view of the spacer 30, and Figures 8(a) to (d) are top views of the internal secondary pipe fitting 1 installed on the inner wall of the manhole 2.

[0052] The spacer 30 is integrally molded from a synthetic resin such as polyvinyl chloride. As shown in Figures 7(a) and 7(e), the outer peripheral shape of the spacer 30 is substantially the same as the outer peripheral shape of the mounting portion 21 of the joint body 10, and a drainage inlet 31 having the same diameter as the drainage inlet 19 of the joint body 10 is formed on the inside. Furthermore, the spacer 30 has insertion holes 32 formed at positions corresponding to the insertion holes 22 formed in the mounting portion 21 of the joint body 10, and temporary fastening holes 33 formed at positions corresponding to the temporary fastening holes 23a.

[0053] As shown in Figures 2 and 3, the outer peripheral shape of the spacer 30 is slightly larger in diameter than the outer peripheral shape of the mounting portion 21, and the non-mounting surface 30a of the spacer 30 has an annular receiving portion 34 formed on the outer edge that protrudes toward the joint body 10, and when the joint body 10 is attached to the spacer 30, the mounting portion 21 of the joint body 10 fits inside the receiving portion 34.

[0054] As shown in Figures 2, 3 and 7, approximately in the center of both the left and right sides of the spacer 30, two pairs of locking pieces 35, 35 which have locking claws 35a protruding inward at their tips and which are elastically deformable outward are formed toward the joint body 10, and as shown in Figure 2, when the joint body 10 is fitted into the spacer 30, each locking piece 35 deforms outward, and then the deformation of the locking pieces 35 returns, so that the locking claws 35a lock both sides of the mounting portion 21 of the joint body 10, and the joint body 10 and the spacer 30 are assembled together.

[0055] As shown in Figures 7(d) and (f), the non-mounting surface 30a of the spacer 30 has a curved surface shape with a curvature that follows the mounting surface 21a of the mounting portion 21, and around the wastewater inlet 31 on the non-mounting surface 30a of the spacer 30, annular ridge portions 36a, 36b, and 36c that protrude toward the fitting body 10 are formed at positions corresponding to the cutout portion 21b, groove portion 21c, and groove portion 21d formed on the mounting surface 21a, as shown in Figures 7(a) and (c), and when the fitting body 10 is mounted to the spacer 30, the ridge portions 36a, 36b, and 36c respectively fit into the cutout portion 21b, groove portion 21c, and groove portion 21d formed on the mounting surface 21a.

[0056] As shown in Figures 8(b) to 8(d), the mounting surface 30b of the spacer 30 has a curved or flat shape with a curvature that conforms to the inner circumferential surface of manholes 2b to 2d other than the No. 1 manhole 2a. There are various types of spacers 30 whose mounting surface 30b has a curved shape that conforms to the inner circumferential surface of manhole 2b (e.g., No. 0 manhole) whose inner wall has a greater curvature than No. 1 manhole 2a, as shown in Figure 8(b), a curved shape that conforms to the inner circumferential surface of manhole 2c (e.g., No. 2 or No. 3 manhole) whose inner wall has a smaller curvature than No. 1 manhole 2a, as shown in Figure 8(c), and a flat shape that conforms to the inner circumferential surface of manhole 2d whose inner wall has a flat surface, as shown in Figure 8(d). By selecting an appropriate spacer 30 according to the manhole to be installed, it is possible to attach the internal secondary pipe fitting 1 to manholes with different inner wall shapes. Furthermore, since the mounting surface 21a of the mounting portion 21 has a curved surface shape that follows the inner surface of the No. 1 manhole 2a, when mounting it to the No. 1 manhole 2a, the fitting body 10 can be attached directly without using a spacer 30, as shown in Figure 8(a).

[0057] As shown in FIGS. 7(a) and 7(c), the mounting surface 30b of the spacer 30 has a notch 37a formed in a circular shape around the drainage inlet 31. The notch 37a has an inner diameter that allows a flange 40b of a flexible joint 40 (described later) that connects the drainage pipe 3 to the manhole 2 to be fitted therein. The mounting surface 30b of the spacer 30 also has an annular groove 37b formed outside the notch 37a, and an annular groove 37c formed outside the groove 37b. An annular watertight gasket P (see FIG. 9(b)) is attached to the groove 37c. The groove 37b is intended to reduce the weight and material of the spacer 30. The portions that define the grooves 37b and 37c function as ribs, enhancing the structural strength of the spacer 30 and stabilizing its shape.

[0058] [Installation status of internal sub-pipe fittings in manholes] Next, the installation of the internal secondary pipe joint 1 into the manhole 2 will be described.

[0059] 9 is a diagram showing the installation of the internal pipe joint 1 to a drainage pipe 3 connected by a flexible joint 40 attached to the inner wall of a manhole 2. The flexible joint 40 is made of a soft material such as rubber, and as shown in FIGS. 9(a) and 9(b), consists of a cylindrical portion 40a into which one end of the drainage pipe 3 is press-fitted, and an annular flange portion 40b that extends outward from one end of the cylindrical portion 40a. The outer diameter of the flange portion 40b is approximately the same as the inner diameter of the notch 21b formed in the mounting surface 21a of the mounting portion 21 of the fitting body 10 and the notch 37a formed in the mounting surface 30b of the spacer 30. When the fitting body 10 or the spacer 30 is installed, the outer periphery of the flange portion 40b can be fitted into the notch 21b or the notch 37a.

[0060] When attaching an internal pipe joint 1 to a drainage pipe 3 connected by a flexible joint 40 attached to the inner wall of a manhole 2, as shown in Figure 9(a), the cylindrical portion 40a of the flexible joint 40 is inserted from inside the manhole 2 into a drainage inlet hole 2h drilled in the manhole 2 to match the position of the drainage pipe 3, and the flange portion 40b is fixed to the inner wall of the manhole 2 with an adhesive or the like, and then one end of the drainage pipe 3 is pressed into the cylindrical portion 40a so that one end faces the inside of the manhole 2.

[0061] Next, as shown in FIG. 9(b), the notch 37a of the spacer 30 integrated with the joint body 10 is fitted into the flange 40b, and the mounting surface 30b is brought into contact with the inner wall of the manhole 2. Then, the spacer 30 is temporarily fastened to the inner wall of the manhole 2 with the temporary fastening bolts KB inserted through the temporary fastening holes 23a and 33. This brings one end of the drain pipe 3 into contact with the drainage inlets 19 and 31. Since the joint body 10 is provided with the gripping portions 25 on both sides, even if the straight pipe 4 or curved pipe 5 is attached to the joint body 10 and has a considerable weight, it is relatively easy to align the pipe by gripping the gripping portions 25 from both sides. Furthermore, because the flange 40b fits into the notch 37a and is accommodated in the notch 37a, the mounting surface 30b can be brought into contact with the inner wall of the manhole 2 even if the flange 40b is thick.

[0062] In this state, the spacer 30 and the mounting portion 21 are fixed to the inner wall of the manhole 2 with mounting means such as bolts B inserted into the four insertion holes 22, 32, and then the outer periphery of the spacer 30 is caulked with caulking material, thereby attaching the internal secondary pipe fitting 1 to the inner wall of the manhole 2. Because the insertion holes 22, 32 are elongated holes extending radially from the center, even if the fixing positions of the mounting means such as bolts B are slightly misaligned, they can be adjusted and the internal secondary pipe fitting 1 can be attached to the optimum position.

[0063] Furthermore, when attaching to No. 1 manhole 2a, without using spacer 30, the notch 21b of the mounting portion 21 of the joint body 10 is fitted into the flange portion 40b, and the mounting surface 21a is abutted against the inner wall of the manhole 2, and then the mounting portion 21 is temporarily fixed to the inner wall of the manhole 2 with temporary fixing bolts KB inserted into the temporary fixing holes 23a, and the mounting portion 21 is fixed to the inner wall of the manhole 2a with an attachment means such as bolts B inserted into the four insertion holes 22.

[0064] In addition, in the above configuration, the manhole 2 is temporarily fixed to the inner wall using a temporary fixing bolt KB, but if the fitting strength of the flange portion 40b to the cutout portion 37a or the cutout portion 21b is high, the temporary fixing may be achieved only by fitting the flange portion 40b to the cutout portion 37a or the cutout portion 21b without using the temporary fixing bolt KB.

[0065] Figure 10 is a diagram showing the installation state of the internal pipe joint 1 to the drainage pipe 3 connected by a flexible joint 50 attached to the outer wall of the manhole 2. The flexible joint 50 is molded from a soft material such as rubber, and as shown in Figure 10, consists of a cylindrical portion 50a into which one end of the drainage pipe 3 is press-fitted, and an annular flange portion 50b that extends outward from one end of the cylindrical portion 50a.

[0066] When attaching an internal secondary pipe joint 1 to a drainage pipe 3 connected by a flexible joint 50 attached to the outer wall of a manhole 2, as shown in Figure 10, the flange portion 50b of the flexible joint 50 is fixed to the outer wall of the manhole 2 with adhesive or the like so as to align with the drainage inlet hole 2h drilled in the manhole 2 to match the position of the drainage pipe 3, and then one end of the drainage pipe 3 is pressed into the tubular portion 50a so that one end faces the inside of the manhole 2.

[0067] 10, the mounting surface 30b of the spacer 30 integrated with the joint body 10 is brought into contact with the inner wall of the manhole 2, and after alignment, the spacer 30 is temporarily fixed to the inner wall of the manhole 2 with the temporary fixing bolts KB inserted through the temporary fixing holes 23a, 33. This brings one end of the drain pipe 3 into a state facing the drainage inlets 19, 31.

[0068] In this state, the spacer 30 and the mounting portion 21 are fixed to the inner wall of the manhole 2 using mounting means such as bolts B inserted into the four insertion holes 22, 32, and then the outer periphery of the spacer 30 is caulked with caulking material, thereby attaching the internal secondary pipe fitting 1 to the inner wall of the manhole 2.

[0069] Furthermore, when attaching to No. 1 manhole 2a, without using spacer 30, the mounting surface 21a of mounting portion 21 of joint body 10 is abutted against the inner wall of manhole 2a, and temporarily fixed to the inner wall of manhole 2a with temporary fixing bolts (not shown) inserted into temporary fixing holes 23a, and mounting portion 21 is fixed to the inner wall of manhole 2a with mounting means such as bolts B inserted into four insertion holes 22.

[0070] As shown in Figure 11(a), when the position where the drainage pipe 3 faces is higher than the bottom of the manhole 2, the insertion port on one end of the straight pipe 4, which has both ends cut to match the height position of the drainage pipe 3 and serves as an insertion port, is inserted and connected to the secondary pipe connection portion 13 of the internal secondary pipe fitting 1, and the insertion port on the other end is inserted and connected to the receiving port 5a of the curved pipe 5, which has a receiving port 5a on one side and a receiving port 5b on the other side, so that the drainage water discharged from below the internal secondary pipe fitting 1 is discharged through the straight pipe 4 and the curved pipe 5 into the invert portion 9 of the manhole 2.

[0071] Also, as shown in Figure 11(b), if the position where the drainage pipe 3 faces is lower than the bottom of the manhole 2, the insertion port 5b of the curved pipe 5 can be inserted into and connected to the secondary pipe connection portion 13 of the internal secondary pipe fitting 1, so that the drainage water discharged from below the internal secondary pipe fitting 1 can be discharged through the curved pipe 5 to the invert portion 9 of the manhole 2.

[0072] In this case, by using a curved pipe 5 having an insertion port at one end and a receiving port 5a at the other end, a common curved pipe 5 can be used whether the curved pipe 5 is connected to the internal secondary pipe fitting 1 via a straight pipe 4 or whether the curved pipe 5 is connected directly to the internal secondary pipe fitting 1.

[0073] [About the effects] In this embodiment, the internal secondary pipe fitting 1 has a cylindrical vertical pipe section 11 extending in the vertical direction at one end thereof, and the width dimension of the upper part 11a of the vertical pipe section 11 is made longer than the depth dimension, thereby ensuring sufficient volume within the vertical pipe section 11 into which wastewater flows from the drain pipe 3, and the width dimension of the lower part 11b of the vertical pipe section 11 is made gradually narrower toward the lower wastewater outlet 13a, thereby forming a wastewater outlet 13a that is short in both the width and depth directions.As a result, a secondary pipe (e.g., a straight pipe 4, a curved pipe 5, etc.) with a smaller diameter than the vertical pipe section 11 can be installed closer to the inner wall of the manhole 2, thereby ensuring more working space within the manhole 2.

[0074] In this embodiment, the upper part 11a of the vertical pipe part 11 has a width dimension greater than the depth dimension, and has a cross-sectional shape that is approximately elliptical, with the width and depth dimensions not changing from the upper end to the lower end. The lower part 11b of the vertical pipe part 11 is formed in a tapered shape, with the width dimension gradually narrowing downward from a position below the lower end of the wastewater inlet 19, while the depth dimension does not change downward while remaining the same, and has a cross-sectional shape that narrows to a circular shape with the width and depth dimensions smaller than the outer diameter of the drain pipe 3. However, at least the width dimension of the upper part 11a of the vertical pipe part 11 The above-mentioned effects can be achieved as long as the length is longer than the depth and the width of the lower portion 11b of the vertical pipe portion 11 gradually narrows toward the wastewater inlet 13a. The upper portion 11a of the vertical pipe portion 11 does not necessarily have to have a generally elliptical cross section, and the lower portion 11b of the vertical pipe portion 11 does not necessarily have to narrow from a generally elliptical cross section to a circular cross section toward the bottom. For example, the shape before narrowing may be a shape other than a generally elliptical cross section, and the shape after narrowing may be a shape other than a generally circular cross section. The depth of the lower portion 11b of the vertical pipe portion 11 may also be gradually narrowed toward the bottom. The lower portion 11b of the vertical pipe portion 11 may also be gradually narrowed toward the bottom from a position above the bottom end of the wastewater inlet 19. Furthermore, the shape in which the width dimension of the lower portion 11b of the vertical pipe portion 11 gradually narrows toward the lower wastewater outlet 13a may be any of a shape in which the width narrows at a constant slope, a shape in which the slope becomes steeper as it goes downward, or a shape in which the slope becomes gentler as it goes downward.

[0075] In addition, in this embodiment, the width dimension of the lower part 11b of the vertical pipe section 11 is gradually narrowed toward the wastewater outlet 13a, while the depth dimension does not change toward the wastewater outlet 13a, so the shape of the lower part 11b of the vertical pipe section 11 does not become complex.

[0076] In this embodiment, the width of the lower portion 11b of the vertical pipe portion 11 gradually narrows from a generally elliptical cross section toward the wastewater outlet 13a having a generally circular cross section, which allows for a smooth flow of wastewater.

[0077] In addition, in this embodiment, the width dimension of the lower part 11b of the vertical pipe section 11 is gradually narrowed from a position below the lowest end of the wastewater inlet 19 toward the wastewater outlet 13a, thereby ensuring sufficient vertical volume of the vertical pipe section 11, so that even if the amount of wastewater flowing into the wastewater inlet 19 temporarily increases, it can be discharged to the wastewater outlet 13a with ease.

[0078] In this embodiment, an upper inspection hatch 12 is formed on the top surface of the vertical pipe section 11, and the width dimension of the upper inspection hatch 12 is longer than the depth dimension, just like the upper part 11a of the vertical pipe section 11, so it is possible to minimize blind spots within the vertical pipe section 11 from the upper inspection hatch 12. Note that in this embodiment, the shape of the upper inspection hatch 12 is the same as the inner peripheral shape of the upper part 11a of the vertical pipe section 11, but this does not necessarily have to be the same shape, and as long as the width dimension is at least formed to be longer than the depth dimension, just like the upper part 11a of the vertical pipe section 11, the same effect as above will be achieved.

[0079] In this embodiment, the internal pipe fitting 1 has a cylindrical vertical pipe section 11 extending in the vertical direction at one end thereof, and an extended pipe section 18 extending from the vertical pipe section 11 to the wastewater inlet 19, and a recessed section 20 extending at a downward incline toward the inner surface 11c of the vertical pipe section 11 is formed on the inner bottom surface of the extended pipe section 18.Therefore, by allowing the wastewater that flows into the extended pipe section 18 to flow out into the vertical pipe section 11 through the recessed section 20, it is possible to prevent the wastewater from stagnating in the extended pipe section 18, thereby suppressing the impact on drainage performance caused by impurities and transported materials contained in the stagnant wastewater.

[0080] In particular, in this embodiment, in order to make it easier to remove the molded product from the mold during injection molding, the inner surface of the extended pipe section 18 is slightly expanded in diameter around its entire circumference from the vertical pipe section 11 at one end toward the wastewater inlet 19 at the other end, which results in a structure in which wastewater is likely to stagnate within the extended pipe section 18.However, by forming a recess 20 on the inner bottom surface of the extended pipe section 18 that extends at a downward angle toward the inner surface 11c of the vertical pipe section 11, it is possible to prevent wastewater from stagnating within the extended pipe section 18, even though the inner bottom surface of the extended pipe section 18 is slightly expanded in diameter toward the wastewater inlet 19.

[0081] In this embodiment, the inner surface of the extended pipe section 18 has a shape that slightly expands in diameter around its entire circumference from the vertical pipe section 11 at one end to the wastewater inlet 19 at the other end, but the inner surface of the extended pipe section 18 may have a shape that maintains the same diameter from the vertical pipe section 11 at one end to the wastewater inlet 19 at the other end, or the inner surface of the extended pipe section 18 may have a shape that expands in diameter from the wastewater inlet 19 at the other end to the vertical pipe section 11 at one end.

[0082] In addition, in this embodiment, the bottom surface of the recess 20 gradually becomes steeper from the extended pipe section 18 toward the inner surface 11c of the vertical pipe section 11, so that wastewater that flows into the recess 20 can be smoothly discharged.

[0083] In addition, in this embodiment, a recess 20 is formed on the inner bottom surface of the extended pipe section 18, i.e., in a portion of the area near the center of the lower half or less of the area on the inner surface of the extended pipe section 18, and since wastewater tends to collect in the recess 20, wastewater that has flowed into the recess 20 can be smoothly discharged even when the flow rate of wastewater is low.

[0084] In this embodiment, the width of the upper portion 11a of the vertical pipe portion 11 is longer than the depth, and the width of the lower portion 11b of the vertical pipe portion 11 gradually narrows toward the wastewater outlet 13a below. However, the above-mentioned effect can be achieved as long as the vertical pipe portion 11 has a cylindrical shape extending at least in the vertical direction and an extended pipe portion 18 extending from the vertical pipe portion 11 to the wastewater inlet 19, and the extended pipe portion 18 has an inner circumferential bottom surface formed with a recessed portion 20 that slopes downward toward the inner circumferential surface 11c of the vertical pipe portion 11. It is not necessary for the width of the upper portion 11a of the vertical pipe portion 11 to be longer than the depth, and it is not necessary for the width of the lower portion 11b of the vertical pipe portion 11 to gradually narrow toward the wastewater outlet 13a below. Therefore, the vertical pipe portion 11 may be formed in a cylindrical shape with a substantially circular cross section. Further, the lower portion 11b of the vertical pipe portion 11 may not be configured to have a reduced diameter toward the wastewater outlet 13a.

[0085] In this embodiment, an inspection hatch 14a is formed at a position opposite the wastewater inlet 19 of the vertical pipe section 11, and since the inner diameter of the inspection hatch 14a is larger than the inner diameter of the wastewater inlet 19, a wide view of the inside of the wastewater inlet 19 can be obtained from the inspection hatch 14a.

[0086] In this embodiment, gripping portions 25 capable of gripping the internal secondary pipe fitting 1 are provided on both sides of the fitting body 10, and therefore, by gripping the gripping portions 25 of the internal secondary pipe fitting 1, the internal secondary pipe fitting 1 can be placed in a stable state inside the manhole 2. Note that in this embodiment, the fitting body 10 is configured to have gripping portions 25 on both sides, but a configuration in which a single gripping portion is provided may also be used. Also, holes into which a hand can be inserted may be provided on the upper left and right sides or on one end side of the upper part of the vertical pipe portion 11, and used as gripping portions.

[0087] In this embodiment, a water stop ring 13b is attached to the secondary pipe connection part 13 having the wastewater outlet 13a, and the water stop ring 13b has an upwardly protruding annular ridge 13d formed thereon, which functions as a mechanism to prevent the pipe inserted from below from coming loose, making it easy to connect the pipe to the wastewater outlet 13a.

[0088] In this embodiment, the secondary pipe connecting portion 13 is formed with an expanded diameter portion 13e that expands in diameter in an upward tapered manner, so that even after the insertion opening of the straight pipe 4 or curved pipe 5 is inserted into the secondary pipe connecting portion 13, the insertion angle of the straight pipe 4 or curved pipe 5 can be adjusted within the range of the inner diameter of the expanded diameter portion 13e. Note that the secondary pipe connecting portion 13 may not have the expanded diameter portion 13e. Furthermore, the secondary pipe connecting portion 13 may simply be a socket without the watertight ring 13b. In this case, the secondary pipe is inserted into the socket and fixed with adhesive.

[0089] In this embodiment, the fitting body 10 is formed with an attachment portion 21 for attaching the internal secondary pipe fitting 1 to the inner wall of the manhole 2, and the attachment portion 21 is formed with an insertion hole 22 through which an attachment member such as a bolt B can be inserted, and a temporary fixing hole 23a for temporarily fixing to the inner wall of the manhole 2, and after the internal secondary pipe fitting 1 is positioned by temporarily fixing it using the temporary fixing hole 23a, the attachment portion 21 can be attached to the inner wall of the manhole 2 with an attachment member.

[0090] Furthermore, in this embodiment, indicator protrusions 24a, 24b indicating the center position of the wastewater inlet 19 are formed on the mounting portion 21, and this allows the worker to check the center position of the wastewater inlet 19, which is not visible from the worker's side, when installing the manhole 2 on the inner wall. In this embodiment, the mounting portion 21 is formed with protrusions to serve as indicators indicating the center position of the wastewater inlet 19, but grooves may also be formed to serve as indicators indicating the center position of the wastewater inlet 19. The indicators may also be located on the side surfaces of the mounting portion 21.

[0091] In this embodiment, a spacer 30 that corresponds to the inner wall shape of the manhole 2 can be attached to the mounting portion 21, making it possible to install a common inner secondary pipe fitting 1 in manholes 2 with different inner wall shapes.

[0092] Furthermore, in this embodiment, the spacer 30 is formed with a locking piece 35 that locks onto the mounting portion 21 of the fitting body 10, and the mounting portion 21 is locked by the locking piece 35, allowing the spacer 30 to be installed on the inner wall of the manhole 2 in a state integrated with the mounting portion 21, thereby enabling efficient installation of the internal secondary pipe fitting 1.

[0093] In this embodiment, two pairs of locking pieces 35, 35 are provided in the approximate center of both the left and right sides of the spacer 30, and are configured to be locked to the mounting portion 21 of the joint body 10. However, the number, shape, and position of the locking pieces can be changed in various ways as long as they can lock the spacer 30 to the mounting portion 21 of the joint body 10, and the same effect can be achieved. Also, locking fittings separate from the spacer 30 may be attached to grooves of the spacer 30, and the spacer 30 may be locked to the mounting portion 21 of the joint body 10 via the locking fittings. Also, without using locking pieces or locking fittings, the ridges 36a, 36b, and 36c may be fitted into the notches 21b, grooves 21c, and grooves 21d formed in the mounting surface 21a, respectively, and the spacer 30 may be integrated with the mounting portion 21 by the clamping force of the ridges 36a, 36b, and 36c. Alternatively, without using a locking piece or locking metal fitting, the mounting portion 21 may be fitted into a receiving portion 34 formed on the spacer 30, and the spacer 30 may be integrated with the mounting portion 21 by the force of being clamped by the receiving portion 34, or an elastic material such as a rubber ring for preventing it from coming off may be attached inside the receiving portion 34, and the mounting portion 21 fitted into the receiving portion 34 may be clamped by the elastic force of the rubber ring, thereby integrating the spacer 30 with the mounting portion 21. Alternatively, the receiving portion 34 may be provided with a plurality of inward-facing ribs, and the spacer 30 may be integrated with the mounting portion 21 by the force of the mounting portion 21 fitted into the receiving portion 34 being clamped by the plurality of ribs.

[0094] Furthermore, the spacer 30 and the joint body 10 may be attached separately, without providing a structure such as a locking piece that integrates the spacer 30 and the mounting portion 21. In this case, for example, a spacer 30 that fits the inner diameter of the manhole 2 may be temporarily fixed to the inner wall of the manhole 2 with temporary fixing bolts, adhesive, or the like, and then the joint body 10 may be placed in an appropriate position relative to the temporarily fixed spacer 30, and then fixed together with the spacer 30 to the inner wall of the manhole 2 with mounting members such as bolts.

[0095] In addition, in this embodiment, temporary fixing holes 33 are formed in the spacer 30 at positions corresponding to the temporary fixing holes 23a formed in the mounting portion 21, and even when the internal secondary pipe fitting 1 is attached via the spacer 30, the internal secondary pipe fitting 1 can be temporarily fixed using the temporary fixing holes 23a.

[0096] Furthermore, by making the outer shape of the spacer 30, including the shape of the temporary fastening portion 23, approximately the same as the outer diameter of the mounting portion 21, the caulking work when attaching the internal secondary pipe fitting 1 to the inner wall of the manhole 2 via the spacer 30 becomes easier.

[0097] In this embodiment, double annular grooves 21c and 21d are formed on the mounting surface 21a of the mounting portion 21, and a waterproof gasket P is placed in groove 21d to seal when the fitting is installed on the inner wall of the manhole 2, and the provision of groove 21c that is not used for sealing can reduce the weight of the fitting body 10. Note that a configuration in which both grooves 21c and 21d are sealed may also be used.

[0098] In addition, in this embodiment, an annular notch 21b is formed on the mounting surface 21a of the mounting portion 21, into which the flange portion 40b of the flexible joint 40 that connects the drain pipe 3 to the inner wall of the manhole 2 can be fitted.By fitting the flange portion 40b of the flexible joint 40 into the notch 21b of the mounting portion 21, the mounting portion 21 can be installed on the inner wall of the manhole with the thickness of the flange portion 40b of the flexible joint 40 relieved within the notch 21b.

[0099] In this embodiment, double annular grooves 37b and 37c are formed on the mounting surface 30b of the spacer 30 that is installed on the inner wall of the manhole 2, and a waterproof gasket P is placed in groove 37c to seal when the spacer 30 is installed on the inner wall of the manhole 2, and the provision of groove 37b that is not used for sealing can reduce the weight of the spacer 30. Note that a configuration in which both grooves 37b and 37c are sealed may also be used.

[0100] In addition, in this embodiment, the mounting surface 30b of the spacer 30, which is installed on the inner wall of the manhole 2, has an annular notch 37a formed thereon into which the flange portion 40b of the flexible joint 40, which connects the drain pipe 3 to the inner wall of the manhole 2, can be fitted.By fitting the flange portion 40b of the flexible joint 40 into the notch 37a of the spacer 30, the spacer 30 can be installed on the inner wall of the manhole with the thickness of the flange portion 40b of the flexible joint 40 relieved within the notch 37a.

[0101] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0102] [About Variation 1] In the internal sub-pipe fitting 1 of this embodiment, the vertical pipe portion 11 is integrally molded, but in the internal sub-pipe fitting 101 of Modification 1, as shown in Fig. 12(a), the shape of the vertical pipe portion 111 is substantially the same as that of the vertical pipe portion 11, but it has a two-piece structure consisting of an upper vertical pipe portion 111a that is molded integrally with the fitting body 110 and whose width and depth dimensions do not change, and a lower vertical pipe portion 111b that is molded separately from the upper vertical pipe portion 111a and whose depth dimension does not change but whose width dimension gradually narrows. Note that the structure other than the vertical pipe portion 111 is the same as that of the internal sub-pipe fitting 1.

[0103] The lower vertical pipe portion 111b has a socket 111c formed at its upper end into which the lower end of the upper vertical pipe portion 111a can be fitted, and the lower end of the upper vertical pipe portion 111a can be fitted into the socket 111c to connect them together.

[0104] As a result, as shown in Figure 12(b), by connecting the lower end of the upper vertical pipe section 111a to the lower vertical pipe section 111b, the insertion port of a straight pipe 4 or a curved pipe 5 can be connected to the secondary pipe connection section 13 formed integrally at the lower end of the lower vertical pipe section 111b.On the other hand, as shown in Figure 12(c), without using the lower vertical pipe section 111b, it is also possible to directly connect the insertion ports 104a, 105a of an elliptical straight pipe 104 and an elliptical curved pipe 105, which have the same cross-sectional shape as the upper vertical pipe section 111a and have receiving ports 104a, 105a formed at one end into which the lower end of the upper vertical pipe section 111a can be inserted.

[0105] Although not specifically shown, it is preferable to provide a water stop ring in the socket 111c that functions as a retaining mechanism, similar to the secondary pipe connection portion 13. This configuration allows the lower end of the upper vertical pipe portion 111a to be easily connected to the socket 111c. Similarly to the secondary pipe connection portion 13, it is also preferable that the socket 111c be formed with an expanded diameter portion that tapers in the opposite direction to the opening of the socket 111c. This configuration allows the insertion angle of the lower end of the upper vertical pipe portion 111a to be adjusted within the range of the inner diameter of the expanded diameter portion even after the lower end of the upper vertical pipe portion 111a is inserted into the socket 111c. Note that the socket 111c may be a simple socket without a water stop ring. In this case, the lower end of the upper vertical pipe portion 111a is simply inserted into the socket 111c and fixed with an adhesive.

[0106] Furthermore, the internal secondary pipe fitting 101 has a receiving port 111c formed at the upper end of the lower vertical pipe section 111b, but instead of having a receiving port 111c formed at the upper end of the lower vertical pipe section 111b, a receiving port (not shown) into which the upper end of the lower vertical pipe section 111b can be inserted may be formed at the lower end of the upper vertical pipe section 111a, and the upper end (insertion port) of the lower vertical pipe section 111b may be inserted into this receiving port to connect them together.With this configuration, it is possible to directly connect the insertion ports of straight pipes 104 and curved pipes 105 whose cross-sectional shape is the same as that of the upper vertical pipe section 111a.

[0107] In this configuration, it is preferable to provide a water stop ring in the receiving port formed at the lower end of the upper vertical pipe section 111a, which functions as a stop mechanism similar to the secondary pipe connecting section 13. This configuration makes it possible to easily connect the upper end of the lower vertical pipe section 111b to the receiving port formed at the lower end of the upper vertical pipe section 111a. It is also preferable that the receiving port formed at the lower end of the upper vertical pipe section 111a be formed with an expanded diameter section that tapers in the opposite direction to the receiving port opening, similar to the secondary pipe connecting section 13. This configuration makes it possible to adjust the insertion angle of the upper end of the lower vertical pipe section 111b, the straight pipe 104, or the curved pipe 105 within the range of the inner diameter of the expanded diameter section, even after the upper end of the lower vertical pipe section 111b or the openings of the straight pipe 104 or the curved pipe 105 are inserted into the receiving port. Furthermore, the receiving port formed at the lower end of the upper vertical pipe portion 111a may be a simple receiving port without a watertight ring, in which case the straight pipe 104 and the curved pipe 105 may be inserted into the receiving port and fixed with adhesive.

[0108] [About Variation 2] 13(a) and 13(b), in the internal secondary pipe fitting 201 of the second modification, the vertical pipe portion 211 is formed in a generally elliptical cross section in which the width dimension is greater than the depth dimension and the width dimension and depth dimension do not change from the upper end to the lower end, and the upper end is open to form an upper inspection hatch 212, and the lower end is also open to form a lower outlet 213. The cross-sectional shape of the vertical pipe portion 211 is the same as the cross-sectional shape of the upper portion 11a of the vertical pipe portion 11 of the internal secondary pipe fitting 1. Note that the structure other than the vertical pipe portion 111 is the same as that of the internal secondary pipe fitting 1.

[0109] A receiving port 214 is formed at the lower end of the vertical pipe portion 211, into which the upper end of the vertical pipe portion 11 of the internal secondary pipe fitting 1 and the upper end of the internal secondary pipe fitting 201 can be inserted, and the upper end of the vertical pipe portion 11 of the internal secondary pipe fitting 1 or the upper end of the internal secondary pipe fitting 201 can be inserted into the receiving port 214, making it possible to connect it to the upper end of the vertical pipe portion 11 of the internal secondary pipe fitting 1 or the upper end of the vertical pipe portion 211 of the internal secondary pipe fitting 201.

[0110] 13(a)(b), it is possible to install one or more internal sub-pipe fittings 201 and internal sub-pipe fittings 1 connected vertically to a plurality of drainage pipes 3, 3 connected vertically to the inner wall of a manhole 2. In this way, it is possible to aggregate the wastewater discharged from the plurality of drainage pipes 3, 3.

[0111] Although not specifically shown, it is preferable to provide the receiving port 214 with a water stop ring that functions as a stop mechanism similar to the secondary pipe connecting portion 13, and this configuration makes it possible to easily connect the upper end of the vertical pipe portion 11 of the internal secondary pipe fitting 1 to the receiving port 214. It is also preferable that the receiving port 214 be formed with an expanded diameter portion that expands in diameter in a tapered shape in the opposite direction to the opening of the receiving port 214, similar to the secondary pipe connecting portion 13, and this configuration makes it possible to adjust the insertion angle of the upper end of the vertical pipe portion 11 within the range of the inner diameter of the expanded diameter portion even after the upper end of the vertical pipe portion 11 of the internal secondary pipe fitting 1 is inserted into the receiving port 214.

[0112] [About Variation 3] 14(a) to 14(c) ((b) and (c) are DD cross-sectional views of (a)), in the internal sub-pipe fitting 301 of the third modification, instead of the insertion holes 22 formed in the mounting portion 21 of the internal sub-pipe fitting 1, insertion holes 302 consisting of large-diameter circular holes and small-diameter elongated holes extending upward from the circular holes are formed at the four corners of the mounting portion 321. The large-diameter circular holes are sized to allow the head of the bolt B to be inserted therethrough, and the lateral width of the elongated holes is narrower than the head of the bolt B and is sized to allow the shaft of the bolt B to be inserted therethrough. In addition, insertion holes 303 having the same shape as the insertion holes 302 are formed in the spacer 330 at positions corresponding to the insertion holes 302.

[0113] When installing the internal secondary pipe fitting 301 of the third modification in the manhole 2, the mounting surface 330b of the spacer 330 integrated with the fitting body 310 is brought into contact with the inner wall of the manhole 2, and alignment is performed to determine the position of the bolt B. At this time, the fitting may be temporarily fixed to the inner wall of the manhole 2 using temporary fixing bolts (not shown) inserted through the temporary fixing holes 23a and 33.

[0114] Then, bolt B is driven into a predetermined position on the inner wall of manhole 2, and then, as shown in Figure 14(b), the head of bolt B is inserted into the circular holes of insertion holes 302 and 303, and the mounting surface 330b of the spacer 330 integrated with the fitting body 310 is abutted against the inner wall of manhole 2, and as shown in Figure 14(c), the entire internal secondary pipe fitting 301 is slid downward, whereby the head of bolt B is supported around the elongated hole of insertion hole 302 in the mounting portion 321, and the internal secondary pipe fitting 301 is attached to the inner wall of manhole 2. When attaching to the No. 1 manhole 2a, without using the spacer 330, the mounting surface 321a of the mounting portion 321 of the joint body 310 is brought into contact with the inner wall of the manhole 2a, and the position of the bolt B is determined by aligning the mounting surface 321a, and the bolt B is driven into the determined position on the inner wall of the manhole 2a in advance. Thereafter, the head of the bolt B is inserted into the circular hole of the insertion hole 302, and the mounting surface 321a of the mounting portion 321 of the joint body 310 is brought into contact with the inner wall of the manhole 2a, and the entire internal sub-pipe joint 301 is slid downward.

[0115] This makes it possible to drive the bolt B in while the inner secondary pipe joint 301 is temporarily separated from the inner wall of the manhole 2.

[0116] [About Variation 4] 15(a)(b) ((b) is an E-E cross-sectional view of (a)), in the internal secondary pipe fitting 401 of the fourth modification, the side wall of the vertical pipe portion 411 is connected to the mounting portion 421, and a part of the mounting portion 421 is formed into a substantially semi-elliptical cross-sectional shape that forms the wall of the vertical pipe portion 411 on the waste water inlet 419 side. Moreover, the vertical pipe portion 411 does not have an extended pipe portion 18 like the fitting body 10 of the internal secondary pipe fitting 1, and the waste water inlet 419 is formed directly in the vertical pipe portion 411. The lower portion 11b of the vertical pipe portion 411 is formed into a tapered shape such that the width dimension gradually narrows downward from a position below the lower end of the waste water inlet 419, similar to the vertical pipe portion 11 of the internal secondary pipe fitting 1, while the depth dimension remains substantially the same downward, and the width dimension and depth dimension are reduced to a circular cross-sectional shape smaller than the outer diameter of the drain pipe 3, and the secondary pipe connecting portion 413 is formed below that.

[0117] With this configuration, a part of the mounting portion 421 forms the wall on the wastewater inlet 419 side of the vertical pipe portion 411, so there is no need for an extension pipe portion connected to the mounting portion 421, which allows for a reduction in the amount of material used, and also reduces the depth width of the fitting body 410, making it possible to secure working space inside the manhole 2 in which the internal secondary pipe fitting 401 is installed.

[0118] [Regarding Variation 5] In the internal pipe fitting 1 of this embodiment, as shown in Figure 16(a), a recessed portion 20 is formed in a part of the inner bottom surface of the extended pipe section 18 of the fitting body 10, the recessed portion 20 having a cutout shape extending toward the inner surface of the vertical pipe section 11. However, as shown in Figure 16(b), a recessed portion 20' having a cutout shape extending toward the inner surface of the vertical pipe section 11 may also be formed over the entire inner bottom surface of the extended pipe section 18 of the fitting body 10.

[0119] [About Variation 6] While the spacer 30 of this embodiment is integrally molded, the spacer 630 of Modification 6 has a two-piece structure separated into upper and lower parts, as shown in Fig. 17. As shown in Figs. 17(a) and 17(b), the spacer 630 is composed of an upper spacer member 631 and a lower spacer member 632.

[0120] The upper spacer member 631 has a notch 631a formed on the lower mounting surface side, and a convex portion 631b formed at the lower end of the notch 631a that protrudes toward the opposite side from the joint body 10. On the other hand, the lower spacer member 632 has a notch 632a formed on the upper non-mounting surface side that has substantially the same shape as the notch 631a, and a concave portion 632b formed at the lower end of the notch 632a that has substantially the same shape as the convex portion 631b. In addition, the lower spacer member 632 has two pairs of locking pieces 635, 635 that have the same shape as the spacer 30 formed on both the left and right sides, facing toward the joint body 10.

[0121] 17(c), by fitting the notches 631a of the upper spacer member 631 into the notches 632a of the lower spacer member 632, the convex portions 631b fit into the concave portions 632b, forming an integrated spacer 630. As shown in FIG.

[0122] Furthermore, the locking piece 635 is provided on the lower spacer member 632, which has a notch 632a formed on the upper non-mounting surface side. Therefore, when the spacer 630 is assembled to the mounting portion 21 of the joint body 10 and both sides of the mounting portion 21 are locked by the locking claws 35a, the lower part of the upper spacer member 631 is clamped between the upper non-mounting surface side of the lower spacer member 632 and the mounting portion 21. In addition, the convex portion 631b fits into the concave portion 632b, which also restricts separation in the vertical direction. Therefore, the upper spacer member 631, the lower spacer member 632, and the joint body 10 are assembled together, and the upper spacer member 631 and the lower spacer member 632 will not separate.

[0123] With this configuration, spacer 630 has a two-piece structure that can be separated into upper and lower parts, so even if the opening 6 of manhole 2 is narrow, spacer 630 can be easily brought inside by dividing it. Note that in variant example 6, spacer 630 has a two-piece structure that can be separated into upper and lower parts, but it may also have a two-piece structure that can be separated into left and right parts, or a configuration that can be divided into three or more pieces, and even in such a configuration, spacer 630 can be easily brought inside manhole 2 by dividing it.

[0124] [About Variation 7] In this embodiment, the spacer 30 is made of synthetic resin, but it may also be made of a flexible material such as rubber.By using this configuration, even if the opening 6 of the manhole 2 is narrow, the spacer 630 can be easily brought inside by dividing it. [Explanation of symbols]

[0125] 1 Internal sub-pipe joint 2 Manholes 3 Drain pipe (inflow pipe) 10. Joint body 11 Vertical pipe section 13 Sub-pipe connection 13a Drainage outlet (outlet) 14 Inspection hatch 14a Inspection hatch 15 Inspection Palate 18 Extension pipe section 19 Drain inlet (inlet) 20 Notch 21 Mounting part 30 spacer

Claims

1. An internal pipe joint to be installed on the inner wall of a manhole, an inlet into which wastewater flows from the inlet pipe; A vertical pipe portion that allows the wastewater flowing in from the inlet to flow out from a lower outlet; Equipped with The upper portion of the vertical pipe portion is formed so that the width dimension along the circumferential direction of the inner wall of the manhole is longer than the depth dimension extending inwardly of the inner wall of the manhole, The width of the lower portion of the vertical pipe portion is gradually narrowed toward the outlet port. An internal pipe joint characterized by:

2. An inspection port is formed in the vertical pipe portion at a position opposite the inlet, The inspection hatch has an inner diameter larger than the inner diameter of the inlet pipe.

2. The internal pipe joint according to claim 1 .

3. a mounting portion for mounting the vertical pipe portion to an inner wall of the manhole; A spacer corresponding to an inner wall shape of a manhole different from the inner wall of the manhole can be attached to the attachment portion.

3. The internal pipe joint according to claim 1 or 2.

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