Internal sub-pipe joint

Abstract

To provide an inner sub pipe joint capable of ensuring more work space inside a manhole.SOLUTION: An inner sub-pipe joint 1 has a cylindrical vertical tube 11 extending in the vertical direction on the front side. Since the width dimension of the upper part of the vertical tube 11 is formed to be longer than the depth dimension, sufficient volume for wastewater that flows in from drain pipe 3 is secured in the vertical tube 11. Also, since the bottom width dimension of the vertical tube 11 is formed to be gradually narrower toward the lower drainage outlet 13a, and the short drainage outlet 13a is formed in both the width direction and the depth direction, a smaller diameter tube than the vertical tube 11 can be installed near the inner wall of manhole 2. With this, a larger workspace can be ensured in the manhole 2. Also, since the width dimension of the lower part of vertical tube 11 is formed so that the width gets gradually narrower from the lowermost position of the wastewater inlet 19 toward the wastewater outlet 13a, sufficient volume for the vertical direction of the vertical tube 11 is ensured.SELECTED DRAWING: Figure 5

Description

Technical Field

[0007] , , , ,

[0001] The present invention relates to an inner auxiliary pipe joint installed in a manhole.

Background Art

[0002] Conventionally, in a manhole into which drainage flows, when the drop of the drainage from the inflow pipe on the inflow side to the bottom of the manhole is large, an inner auxiliary pipe may be installed on the inner wall of the manhole. The inner auxiliary pipe consists of an inner auxiliary pipe joint that changes the downward flow direction of the drainage and a sub-pipe connected to the inner auxiliary pipe joint that guides the drainage downward. By discharging the drainage from near the bottom of the manhole, there are those that prevent the scattering of the drainage flowing into the manhole, erosion of the bottom of the manhole, noise, etc. (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention 、 aims to provide an inner auxiliary pipe joint that can secure a larger working space inside the manhole.

Means for Solving the Problems

[0007] In order to solve the above problems, the inner auxiliary pipe joint according to claim 1 of the present invention is <000°032>an inner auxiliary pipe joint installed on the inner wall of the manhole, an inflow port into which drainage from the inflow pipe flows, a vertical pipe portion that allows the drainage flowing in from the inflow port to flow out from the lower outflow port, and is provided with the upper part of the vertical pipe portion has a width dimension along the circumferential direction of the inner wall of the manhole that does not change vertically, The lower part of the vertical pipe section is such that the width dimension is at the lowest end of the inlet. Place It is formed to gradually narrow towards the outlet. It consists of a reduced diameter section and a connecting section extending from the reduced diameter section to the outlet, the connecting section being formed to gradually widen from the top towards the outlet downwards, and further tapering to narrow, and a water-sealing ring is provided on the inner surface of the lower end of the connecting section. It is characterized by the following. This feature ensures sufficient volume within the vertical pipe section into which wastewater flows from the inlet pipe. Furthermore, the width of the lower part of the vertical pipe section gradually narrows towards the outlet, allowing for the installation of a pipe with a smaller diameter than the vertical pipe section, thus providing more working space within the manhole. In addition, sufficient volume is ensured in the vertical direction of the vertical pipe section, allowing for ample capacity to discharge wastewater into the outlet even if the amount of wastewater flowing into the inlet temporarily increases. Moreover, blind spots within the vertical pipe section from above can be minimized. Furthermore, the width of the lower part of the vertical pipe section is approximately equal to the lowest point of the inlet. Place By gradually narrowing the width towards the outlet, sufficient vertical volume can be secured in the vertical direction of the vertical pipe section. The internal sub-pipe joint of claim 2 of the present invention is the internal sub-pipe joint described in claim 1, The lower part of the vertical pipe section is directed toward an outlet with a roughly circular cross-section, where the width dimension and the depth dimension extending inward into the inner wall of the manhole are roughly the same. The shape It has been done It is characterized by the following. According to this feature, the lower part of the vertical pipe section has a width dimension that extends towards the outlet, which has a roughly circular cross-section. Formed Therefore, the drainage flow becomes smoother. The internal sub-pipe joint of claim 3 of the present invention is the internal sub-pipe joint according to claim 1 or 2, The vertical pipe section comprises an upper vertical pipe section whose width dimension does not change from top to bottom, and a section molded separately from the upper vertical pipe section and connected below the upper vertical pipe section. be It consists of a lower vertical pipe section and It is characterized by the following. This feature allows for connecting the lower vertical pipe section below the upper vertical pipe section and connecting it to a pipe shorter than the width dimension of the upper vertical pipe section, or, without connecting the lower vertical pipe section, connecting it to a pipe below the upper vertical pipe section that is the same width dimension as the first vertical pipe section. The internal sub-pipe joint of claim 4 of the present invention is an internal sub-pipe joint according to any one of claims 1 to 3, An inspection port is formed in the vertical pipe section at a position opposite the inlet. The inspection opening is larger than the inner diameter of the inlet pipe. It is characterized by the following. This feature allows for a wide view of the inside of the inlet pipe from the inspection opening, as the inspection opening is larger than the inner diameter of the inlet pipe. The internal sub-pipe joint of claim 5 of the present invention is an internal sub-pipe joint according to any one of claims 1 to 4, The vertical pipe section is provided with temporary fixing holes for temporarily securing it to the inner wall of the manhole. It is characterized by the following. This feature allows the vertical pipe section to be positioned by temporarily securing it using the temporary fixing holes. Claims of the present invention 6 The internal sub-pipe joint is as described in claim 1~ 5 An internal sub-pipe joint as described in any of the following: The internal sub-pipe joint is provided with a gripping portion capable of gripping it. It is characterized by the following. This feature allows the internal sub-pipe joint to be positioned stably inside the manhole by gripping its gripping portion. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional perspective view of a manhole in which an internal sub-pipe joint is installed, as an embodiment to which the present invention is applied. [Figure 2] This is an external perspective view of the internal sub-pipe fitting of this embodiment. [Figure 3] This is an exploded perspective view of the internal sub-pipe joint of this embodiment. [Figure 4] (a) to (e) are the front view, side view, top view, rear view, and bottom view of the joint body, respectively. [Figure 5] This is a cross-sectional view AA of Figure 4(b). [Figure 6](a) is a partially broken perspective view of the joint body, and (b) is a cross-sectional view taken along line B-B of FIG. 4(d). [Figure 7] (a) to (f) are respectively a front view, a side view, a cross-sectional view taken along line C-C of (a), a top view, a rear view, and a bottom view of the spacer. [Figure 8] (a) to (d) are top views of the inner auxiliary pipe joint in a state of being installed on the inner wall of the manhole. [Figure 9] (a) and (b) are diagrams showing the mounting situation of the inner auxiliary pipe joint with respect to a drain pipe connected by a flexible joint attached to the inner wall of the manhole. [Figure 10] It is a diagram showing the mounting situation of the inner auxiliary pipe joint with respect to a drain pipe connected by a flexible joint attached to the outer wall of the manhole. [Figure 11] (a) and (b) are cross-sectional views showing the state in which the inner auxiliary pipe joint is installed in the manhole. [Figure 12] (a) to (c) are diagrams showing the inner auxiliary pipe joint in Modification 1. [Figure 13] (a) and (b) are diagrams showing the inner auxiliary pipe joint in Modification 2. [Figure 14] (a) to (c) are diagrams showing the inner auxiliary pipe joint in Modification 3. [Figure 15] (a) and (b) are diagrams showing the inner auxiliary pipe joint in Modification 4. [Figure 16] (a) is a diagram showing the concave notch, and (b) is a diagram showing a modification of the concave notch. [Figure 17] (a) to (c) are diagrams showing modifications of the spacer.

Mode for Carrying Out the Invention

[0009] [Mode [1]] Conventionally, in manholes into which wastewater flows, if there is a large drop in the water level from the inflow pipe to the bottom of the manhole, an internal sub-pipe may be installed on the inner wall of the manhole. The internal sub-pipe consists of an internal sub-pipe joint that changes the direction of wastewater flow downward, and a sub-pipe connected to this internal sub-pipe joint that guides the wastewater downward. By discharging the wastewater from near the bottom of the manhole, it prevents splashing of wastewater flowing into the manhole, erosion of the bottom of the manhole, and noise (for example, Japanese Patent Publication No. 2005-30162).

[0010] Such internal sub-pipes are installed protruding from the inside of the manhole, which reduces the working space inside the manhole. On the other hand, although the amount of wastewater flowing from the inlet pipe into the internal sub-pipe may increase temporarily, this condition does not persist. If the internal sub-pipe fitting has a certain capacity that takes this inflow into account, drainage is possible even if the diameter of the sub-pipe is smaller than that of the inlet pipe. Therefore, by making the sub-pipe smaller in diameter than the inlet pipe, it is possible to secure working space inside the manhole.

[0011] However, in the case of an internal sub-pipe joint with a circular cross-sectional shape, as described in Japanese Patent Publication No. 2005-30162, if the diameter is reduced to match the diameter of the sub-pipe connected to the outlet of the internal sub-pipe joint, while considering the amount of wastewater flowing in from the inlet pipe, although the smaller diameter of the sub-pipe allows for more working space inside the manhole, the space created between the sub-pipe and the inner wall of the manhole becomes wasted, and the space created by the smaller diameter of the sub-pipe cannot be fully utilized.

[0012] In contrast, the internal sub-pipe joint of form 1 is, An internal sub-pipe joint installed on the inner wall of a manhole, The inlet through which wastewater flows in from the inlet pipe, A vertical pipe section that allows wastewater flowing in from the aforementioned inlet to be discharged from the outlet below, Equipped with, The upper part of the vertical pipe section is formed such that the width dimension along the circumferential direction of the inner wall of the manhole is longer than the depth dimension extending inward from the inner wall of the manhole. The lower part of the vertical pipe section is formed so that its width gradually narrows towards the outlet. It is characterized by the following. According to this feature, the upper part of the vertical pipe is formed so that the width dimension along the circumferential direction of the manhole's inner wall is longer than the depth dimension extending into the manhole, thereby ensuring sufficient volume within the vertical pipe into which wastewater flows from the inlet pipe. Furthermore, the lower part of the vertical pipe is formed so that the width dimension gradually narrows towards the outlet below, creating a short outlet in both the width and depth directions. This allows a pipe with a smaller diameter than the vertical pipe to be installed closer to the manhole's inner wall, thereby securing more working space inside the manhole.

[0013] [Form 2] The internal sub-pipe fitting of form 2 is the internal sub-pipe fitting described in form 1, The lower part of the vertical pipe section does not change in depth toward the outlet. It is characterized by the following: According to this feature, the lower part of the vertical pipe section is formed with a gradually narrowing width towards the outlet, while the depth does not change towards the outlet, thus keeping the shape of the lower part of the vertical pipe section simple.

[0014] [Form 3] The internal sub-pipe fitting of form 3 is the internal sub-pipe fitting described in form 1 or 2, The lower part of the vertical pipe section has a roughly elliptical cross-section where the width is greater than the depth, and the width gradually narrows towards the outlet, which has a roughly circular cross-section where the width and depth are roughly the same. It is characterized by the following: According to this feature, the width of the lower part of the vertical pipe gradually narrows from a roughly elliptical cross-section to a roughly circular cross-section towards the outlet, resulting in a smoother drainage flow.

[0015] [Form 4] The internal sub-pipe fitting of form 4 is an internal sub-pipe fitting described in any of forms 1 to 3, The lower part of the vertical pipe section is formed so that the width dimension gradually narrows from a position below the lowest end of the inlet toward the outlet. It is characterized by the following. This feature allows the width of the lower part of the vertical pipe to gradually narrow from below the lowest point of the inlet towards the outlet, and sufficient vertical volume can be secured in the vertical direction of the vertical pipe. Therefore, even if the amount of wastewater flowing into the inlet temporarily increases, it can be discharged to the outlet with ample margin.

[0016] [Form 5] The internal sub-pipe fitting of form 5 is an internal sub-pipe fitting described in any of forms 1 to 4, An upper inspection opening is formed on the upper surface of the vertical pipe section. The upper inspection opening is formed such that its width is longer than its depth. It is characterized by the following. According to this feature, the upper inspection opening is formed with a width dimension that is longer than the depth dimension, just like the upper part of the vertical pipe section, thus minimizing blind spots inside the vertical pipe section when viewed from the upper inspection opening.

[0017] [Form 6] The internal sub-pipe fitting of form 6 is an internal sub-pipe fitting described in any of forms 1 to 5, The aforementioned vertical pipe section is, The first vertical pipe section, which constitutes the upper part of the aforementioned vertical pipe section, The lower part of the vertical pipe section is formed by a second vertical pipe section connected to the lower part of the first vertical pipe section, Equipped with It is characterized by the following. This feature allows for the connection of a second vertical pipe section below the first vertical pipe section, or to connect a pipe shorter than the width of the first vertical pipe section, or to connect a pipe the same width as the first vertical pipe section below the first vertical pipe section without connecting the second vertical pipe section.

[0018] [Form 7] Conventionally, in manholes into which wastewater flows, if there is a large drop in the water level from the inflow pipe to the bottom of the manhole, an internal sub-pipe may be installed on the inner wall of the manhole. The internal sub-pipe consists of an internal sub-pipe joint that changes the direction of wastewater flow downward, and a sub-pipe connected to this internal sub-pipe joint that guides the wastewater downward. By discharging the wastewater from near the bottom of the manhole, it prevents splashing of wastewater flowing into the manhole, erosion of the bottom of the manhole, and noise (for example, Japanese Patent Publication No. 2005-30162).

[0019] The internal sub-pipe joints that make up such internal sub-pipes are bent in an L-shape when viewed from the side, and change the direction of wastewater flowing in from the side downwards. As a result, wastewater may accumulate in the bent pipe, and the foreign matter and materials contained in the accumulated wastewater may affect the drainage performance.

[0020] In contrast, the internal sub-pipe joint of form 7 is, An internal sub-pipe joint installed on the inner wall of a manhole, The inlet through which wastewater flows in from the inlet pipe, A vertical pipe section that allows wastewater flowing in from the aforementioned inlet to be discharged from the outlet below, An extension pipe section extending from the vertical pipe section to the inlet section, Equipped with, A recessed portion extending into the vertical pipe portion is formed on the inner bottom surface of the extension pipe portion. It is characterized by the following. According to this feature, a recessed section extending into the vertical pipe is formed on the inner bottom surface of the extension pipe section that extends from the vertical pipe section to the inlet. This prevents wastewater from accumulating in the extension pipe section by allowing it to flow out into the vertical pipe section through the recessed section, thereby suppressing the impact on drainage performance caused by foreign matter and conveyed materials contained in the accumulating wastewater.

[0021] [Form 8] The internal sub-pipe fitting of form 8 is the internal sub-pipe fitting described in form 7, The recessed portion has a bottom surface that gradually becomes steeper from the extension pipe portion towards the vertical pipe portion. It is characterized by the following. This feature allows wastewater that flows into the recessed area to be discharged smoothly.

[0022] [Form 9] The internal sub-pipe fitting of form 9 is an internal sub-pipe fitting described in any of forms 1 to 8, An inspection port is formed in the vertical pipe section at a position opposite the inlet. The inspection opening is larger than the inner diameter of the inlet pipe. It is characterized by the following. This feature allows for a wide view of the inside of the inlet pipe from the inspection opening, as the inspection opening is larger than the inner diameter of the inlet pipe.

[0023] [Form 10] The internal sub-pipe fitting of form 10 is an internal sub-pipe fitting described in any of forms 1 to 9, The internal sub-pipe joint is provided with a gripping portion capable of gripping it. It is characterized by the following. This feature allows the internal sub-pipe joint to be positioned stably inside the manhole by gripping its gripping portion.

[0024] [Form 11] The internal sub-pipe fitting of form 11 is an internal sub-pipe fitting described in any of forms 1 to 10, The outlet has a receiving opening that is equipped with a mechanism to prevent the pipe inserted from below from coming loose. It is characterized by the following. This feature allows for easy connection of a pipe to the outlet.

[0025] [Form 12] The internal sub-pipe fitting of form 12 is an internal sub-pipe fitting described in any of forms 1 to 11, The vertical pipe section is provided with an attachment part for attaching it to the inner wall of the manhole, The mounting portion has a mounting hole through which the mounting member can be inserted, and a temporary fixing hole for temporarily fixing it to the inner wall of the manhole. It is characterized by the following. According to this feature, the internal sub-pipe joint can be temporarily fixed using the temporary fixing holes to position it, and then the mounting part can be attached to the inner wall of the manhole using the mounting member.

[0026] [Form 13] The internal sub-pipe fitting of form 13 is an internal sub-pipe fitting described in any of forms 1 to 12, The vertical pipe section is provided with an attachment part for attaching it to the inner wall of the manhole, The mounting portion is formed with an indicator portion that shows the center position of the inlet. It is characterized by the following. This feature allows workers to confirm the center position of the inlet, which is not visible from the worker's side, while installing it on the inner wall of a manhole.

[0027] [Form 14] The internal sub-pipe fitting of form 14 is an internal sub-pipe fitting described in any of forms 1 to 13, The vertical pipe section is provided with an attachment part for attaching it to the inner wall of the manhole, It is possible to attach a spacer to the mounting portion that corresponds to the shape of the inner wall of the manhole. It is characterized by the following. This feature allows a common internal sub-pipe fitting to be installed in manholes with different internal wall shapes by attaching a spacer to the mounting part that corresponds to the shape of the manhole's inner wall.

[0028] [Form 15] The internal sub-pipe fitting of form 15 is the internal sub-pipe fitting described in form 14, The spacer is provided with a locking portion for locking the mounting portion, The spacer can be installed on the inner wall of the manhole in an integrated state with the mounting portion, as the mounting portion is locked by the locking portion. It is characterized by the following. This feature allows the spacer and mounting part to be installed as a single unit on the inner wall of the manhole, enabling efficient installation of the internal sub-pipe joint.

[0029] [Form 16] The internal sub-pipe fitting of form 16 is the internal sub-pipe fitting described in form 14 or 15, The spacer is separable. It is characterized by the following. This feature allows the spacer to be easily brought inside even if the manhole entrance is narrow, by dividing it into sections.

[0030] [Form 17] The internal sub-pipe fitting of form 17 is an internal sub-pipe fitting described in any of forms 14 to 16, The spacer is formed of a flexible material. It is characterized by the following. This feature allows the spacer to be easily brought inside even if the manhole entrance is narrow, by bending it.

[0031] [Form 18] The internal sub-pipe fitting of form 18 is an internal sub-pipe fitting described in any of forms 14 to 17, The mounting portion has temporary fixing holes formed in it for temporarily fixing it to the inner wall of the manhole. The spacer has temporary fixing holes formed in it at positions corresponding to the temporary fixing holes in the mounting portion. It is characterized by the following. This feature allows for temporary fastening of the internal sub-pipe joint using the temporary fastening hole, even when the internal sub-pipe joint is installed via a spacer.

[0032] [Form 19] The internal sub-pipe fitting of form 19 is an internal sub-pipe fitting described in any of forms 14 to 18, The surface of the spacer that is installed on the inner wall of the manhole has an annular first recess and an annular second recess located outside the first recess. When installing the manhole on its inner wall, the soft material is placed in either the first recess or the second recess. It is characterized by the following. According to this feature, one of the recesses is sealed by placing a soft material inside, and the spacer can be made lighter by including a recess that is not used for sealing.

[0033] [Form 20] The internal sub-pipe fitting of form 20 is an internal sub-pipe fitting described in any of forms 14 to 19, The spacer has a fitting portion formed therein that allows a part of a flexible joint connecting the inlet pipe to the inner wall of the manhole to be fitted into it. It is characterized by the following. This feature allows the spacer to be installed while the thickness of the flexible joint is accommodated within the fitting portion by fitting a portion of the flexible joint into the fitting portion.

[0034] The embodiments of the internal sub-pipe joint according to the present invention will be described below based on examples. [Examples]

[0035] Figure 1 is a cross-sectional perspective view of a manhole with the internal sub-pipe joint of this embodiment installed. As shown in Figure 1, the internal sub-pipe joint 1 of this embodiment is installed inside a manhole 2 buried below the ground surface as a relay facility for the sewer system. It redirects the flow direction of wastewater flowing in from the drain pipe 3 connected to the upper side of the manhole 2 downwards and guides it to the invert section 9 formed at the bottom of the manhole 2, described later, via a straight pipe 4 and / or curved pipe 5 connected below the internal sub-pipe joint 1, thereby preventing splashing, erosion, and noise from the wastewater. The internal sub-pipe is composed of the internal sub-pipe joint 1 and the straight pipe 4 and / or curved pipe 5 described above.

[0036] [About manholes] Manhole 2 is a concrete structure, and as shown in Figure 1, a slender cylindrical body is buried vertically in the ground. The upper part of the body of manhole 2 is formed in a conical shape (not shown) that narrows in diameter towards the top, and an opening 6 is provided at its upper end. A disc-shaped cover 7 that allows the opening 6 to be opened and closed is detachably attached to the opening 6, and the cover 7 is fitted into the opening 6 with its upper side aligned with the ground surface. At the inner bottom of manhole 2, an invert section 9 with a roughly semicircular cross-section is formed, which slopes toward the drain pipe 8 connected to the lower side of manhole 2.

[0037] [Regarding internal sub-pipe joints] Figure 2 is an external perspective view of the internal sub-pipe joint of this embodiment, and Figure 3 is an exploded perspective view of the internal sub-pipe joint of this embodiment. As shown in Figures 2 and 3, the internal sub-pipe joint 1 consists of a joint body 10 and a spacer 30.

[0038] [Regarding the fitting body] Figures 4(a) to 4(e) are the front view, side view, top view, rear view, and bottom view of the joint body 10, respectively. Figure 5 is a cross-sectional view of section AA of Figure 4(b). Figure 6(a) is a partially broken perspective view of the joint body. Figure 6(b) is a cross-sectional view of section BB of Figure 4(d).

[0039] The joint body 10 is integrally molded from a synthetic resin such as polyvinyl chloride. At one end of the joint body 10 (hereinafter, the side facing the center of the manhole 2 when the internal sub-pipe joint 1 is installed in the manhole 2 will be referred to as the first end, and the side facing the outer wall of the manhole 2 when the internal sub-pipe joint 1 is installed in the manhole 2 will be referred to as the second end), a cylindrical vertical pipe section 11 extending in the vertical direction is formed, as shown in Figures 2 to 6. The upper part 11a of the vertical pipe section 11 (see Figures 4 and 6) has a width dimension (the dimension along the circumferential direction of the inner wall of the manhole 2) that is greater than the depth dimension (the dimension extending toward the inner diameter side of the manhole 2), and is formed in a substantially elliptical cross-section in which the width dimension and depth dimension do not change from the upper end to the lower end, with the upper end being open to form an upper inspection port 12. Furthermore, the width dimension of the upper part 11a of the vertical pipe section 11 is greater than the outer diameter of the drain pipe 3, and the depth dimension is smaller than the outer diameter of the drain pipe 3. The shape of the upper inspection opening 12 is the same as the cross-sectional shape of the upper part 11a of the vertical pipe section 11, and is an approximately elliptical shape in which the width dimension is greater than the depth dimension.

[0040] 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 cross-sectional shape as the upper part 11a of the vertical pipe section 11, that is, it is an approximately elliptical shape in which the width dimension is greater than the depth dimension. From a position below the lower end 19U of the drain inlet 19, which will be described later, the width dimension gradually narrows downwards, forming a tapered shape, while the depth dimension remains the same and does not change downwards. The lower end of the lower part 11b of the vertical pipe section 11 is reduced in diameter to a circular shape with a cross-sectional shape smaller than the outer diameter of the drain pipe 3, with both the width and depth dimensions being smaller than the outer diameter of the drain pipe 3.

[0041] Below the vertical pipe section 11, as shown in Figures 2 to 6, a sub-pipe connection section 13 is formed continuously with the lower part 11b of the vertical pipe section 11. As shown in Figures 5 and 6(b), the sub-pipe connection section 13 has a drain outlet 13a at its lower end that is approximately the same size as the outer diameter of the insertion opening of the straight pipe 4 or curved pipe 5, and an annular groove 13c is formed on the inner surface of the sub-pipe connection section 13 into which a water-stopping ring 13b made of a soft material such as rubber is fitted. The water-stopping ring 13b has an annular protrusion 13d that protrudes upward and inward, and the protrusion 13d prevents the straight pipe 4 or curved pipe 5 inserted into the sub-pipe connection section 13 from below from being pulled out downward. Furthermore, the sub-pipe connection section 13 has an enlarged diameter section 13e formed above the groove section 13c, that is, an enlarged diameter section 13e that tapers in the opposite direction to the opening (drain outlet 13a) of the sub-pipe connection section 13. This allows the insertion angle of the straight pipe 4 or curved pipe 5 to be adjusted within the range of the inner diameter of the enlarged diameter section 13e even after the insert of the straight pipe 4 or curved pipe 5 has been inserted into the sub-pipe connection section 13.

[0042] As shown in Figure 3, the joint body 10 has an inspection port 14 that opens on one end of the vertical pipe section 11 and extends toward the other end, with an inspection port 14a opening at the end of the inspection port section 14. As shown in Figure 9(b), the inner diameter of the inspection port 14a is larger than the inner diameter of the drain pipe 3 connected to the internal sub-pipe joint 1. The inspection port 14a can be closed with an inspection port cover 15.

[0043] The inspection port cover 15 is molded from a synthetic resin such as polyvinyl chloride. As shown in Figure 3, one end has a flange portion 15a with a larger diameter than the inspection port 14a, and the other end has a projection portion 15b that fits into the inspection port portion 14 to close the inspection port 14a. An annular recess (not shown) is formed around the projection portion 15b, and a water-stopping ring 15c made of a soft material such as rubber is attached to it.

[0044] As shown in Figures 2 and 3, the inspection port cover 15 has a locking groove 15d formed in the vertical direction, and locking parts 16, 16 are formed at the upper and lower positions of the inspection port 14, each having a locking hole 16a that protrudes outward and penetrates in the vertical direction. When the inspection port 14a is closed by the inspection port cover 15, the locking pin 17 is inserted from above into the locking holes 16a of the respective locking parts 16, 16, thereby restricting the opening of the inspection port cover 15 by the locking pin 17 which is locked in the locking groove 15d.

[0045] As shown in Figures 2 to 4 and 6, the joint body 10 has a short, tubular extension pipe section 18 that opens to the other end of the vertical pipe section 11, extends toward the other end, and has a drainage inlet 19 opening inside the mounting section 21, which will be described later. The inner circumferential surface of the extension pipe section 18 is slightly wider in diameter along its entire circumference from the vertical pipe section 11 at one end toward the drainage inlet 19 at the other end. In addition, a recessed portion 20 is formed in the inner bottom surface of the extension pipe section 18, that is, in a part of the area near the center of the lower half of the inner circumferential surface of the extension pipe section 18, as shown in Figures 5 and 6(a) and 6(b), which is cut out to extend downward toward the inner circumferential surface 11c of the vertical pipe section 11. As shown in Figure 6(b), the bottom surface of the recessed portion 20 is formed in a substantially arc shape, where the inclination angle θ of the bottom surface gradually becomes steeper from the extended pipe portion 18 towards the inner circumferential surface 11c of the vertical pipe portion 11.

[0046] As shown in Figures 2-6, a roughly rectangular mounting portion 21 is formed on the other end of the joint body 10, with a drainage inlet 19 opening on the inside. The mounting portion 21 has a curved mounting surface 21a with a curvature that follows the inner circumference of manhole a2 (see Figure 8(a)), as shown in Figures 4(c) and 4(e). The mounting portion 21 also has through holes 22 that penetrate in the front-to-back direction for mounting members such as fixing bolts B, formed at the four corners. The through holes 22 are elongated holes that extend from the center of the mounting portion 21 towards the four outer corners. In addition, a temporary fixing portion 23 that protrudes upward is formed on the upper edge of the mounting portion 21, and a temporary fixing hole 23a that penetrates in the front-to-back direction is formed in the temporary fixing portion 23. Furthermore, as shown in Figure 5, indicator protrusions 24a, 24a are formed at both the left and right ends of the mounting portion 21 at positions where the horizontal center line C1 of the drain inlet 19 passes through, and an indicator protrusion 24b is formed at the upper end of the temporary fixing portion 23 at a position where the vertical center line C2 of the drain inlet 19 passes through.

[0047] As shown in Figures 4(a) and 6(a)(b), the mounting surface 21a of the mounting portion 21 has a notch 21b that is cut out in an annular shape around the drain inlet 19. The notch 21b has an inner diameter that allows the flange portion 40b of the flexible joint 40, which will be described later and connect the drain pipe 3 to the manhole 2, to be fitted. In addition, an annular groove 21c is formed on the outside of the notch 21b on the mounting surface 21a, and an annular groove 21d is formed on the outside of the groove 21c. An annular water-sealing packing P (see Figure 9(b)) is attached to the groove 21d. Note that the water-sealing packing P is not attached when the manhole 2 is mounted using the spacer 30. The groove 21c is intended to reduce the weight of the joint body 10 and the amount of material used. Furthermore, the portions defining these grooves 21c and 21d act as ribs, increasing the structural strength of the mounting portion 21 and stabilizing its shape.

[0048] As shown in Figures 2 to 4, gripping portions 25, 25 are formed on both sides of the joint body 10, extending from the mounting portion 21 to the side of the vertical pipe portion 11 and inclined diagonally upward toward one end, making it possible to grip the joint body 10 from both sides.

[0049] [About spacers] Figures 7(a) to 7(f) are the front view, side view, CC cross-section view, top view, rear view, and bottom view of the spacer 30, respectively, and Figures 8(a) to 8(d) are top views of the internal sub-pipe joint 1 installed on the inner wall of the manhole 2.

[0050] 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 circumference of the spacer 30 is substantially the same as the outer circumference of the mounting portion 21 of the joint body 10, and a drainage inlet 31 with the same diameter as the drainage inlet 19 of the joint body 10 is formed on the inside. In addition, the spacer 30 has through holes 32 formed at positions corresponding to the through holes 22 formed in the mounting portion 21 of the joint body 10, and a temporary fixing hole 33 formed at a position corresponding to the temporary fixing hole 23a.

[0051] As shown in Figures 2 and 3, the outer diameter of the spacer 30 is slightly larger than that of the mounting portion 21. The non-mounting surface 30a of the spacer 30 has an annular receiving portion 34 that protrudes toward the joint body 10 side on its outer edge. 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.

[0052] As shown in Figures 2, 3, and 7, the spacer 30 has two pairs of locking pieces 35, 35 facing the joint body 10, each having a locking claw 35a that protrudes inward at its tip and is elastically deformable outward. 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 to its original state, causing the locking claws 35a to lock both sides of the mounting portion 21 of the joint body 10, thereby assembling the joint body 10 and the spacer 30 as a single unit.

[0053] As shown in Figures 7(d) and 7(f), the non-mounting surface 30a of the spacer 30 has a curved shape with a curvature that is in line with the mounting surface 21a of the mounting portion 21. Around the drain inlet 31 on the non-mounting surface 30a of the spacer 30, as shown in Figures 7(a) and 7(c), annular protrusions 36a, 36b, and 36c are formed that protrude toward the joint body 10 at positions corresponding to the notches 21b, grooves 21c, and grooves 21d formed on the mounting surface 21a. When the joint body 10 is attached to the spacer 30, the protrusions 36a, 36b, and 36c fit into the notches 21b, grooves 21c, and grooves 21d formed on the mounting surface 21a, respectively.

[0054] The mounting surface 30b of the spacer 30 is either a curved or flat shape with a curvature that follows the inner circumferential surface of manholes 2b to 2d other than manhole 1 2a, as shown in Figures 8(b) to 8(d). As for the spacer 30, the shape of its mounting surface 30b can be a curved surface that follows the inner circumferential surface of manhole 2b (e.g., manhole 0) whose inner wall curvature is greater than that of manhole 1 2a, as shown in Figure 8(b); a curved surface that follows the inner circumferential surface of manhole 2c (e.g., manholes 2 and 3) whose inner wall curvature is smaller than that of manhole 1 2a, as shown in Figure 8(c); or a flat shape that follows the inner circumferential surface of manhole 2d whose inner wall is flat, as shown in Figure 8(d). By selecting the appropriate spacer 30 according to the manhole to be installed, it is possible to install the internal sub-pipe joint 1 on manholes with different inner wall shapes. Furthermore, since the mounting surface 21a of the mounting portion 21 is a curved surface that follows the inner circumference of the No. 1 manhole 2a, when attaching to the No. 1 manhole 2a, the joint body 10 can be attached directly without using the spacer 30, as shown in Figure 8(a).

[0055] As shown in Figures 7(a) and 7(c), the mounting surface 30b of the spacer 30 has a notch 37a that is cut out in an annular shape around the drain inlet 31. The notch 37a has an inner diameter that allows the flange portion 40b of the flexible joint 40, which will be described later and connect the drain pipe 3 to the manhole 2, to be fitted. In addition, an annular groove 37b is formed on the mounting surface 30b of the spacer 30 outside the notch 37a, and an annular groove 37c is formed on the outside of groove 37b. An annular water-stopping packing P (see Figure 9(b)) is attached to groove 37c. The groove 37b is intended to reduce the weight of the spacer 30 and the amount of material used. Furthermore, the parts defining these grooves 37b and 37c act as ribs, increasing the structural strength of the spacer 30 and stabilizing its shape.

[0056] [Regarding the installation status of internal sub-pipe fittings in manholes] Next, we will explain how the internal sub-pipe joint 1 is attached to the manhole 2.

[0057] Figure 9 shows the installation of an internal sub-pipe joint 1 to a drain pipe 3 connected by a flexible joint 40 attached to the inner wall of a manhole 2. The flexible joint 40 is molded from a soft material such as rubber and, as shown in Figures 9(a) and 9(b), consists of a cylindrical portion 40a into which one end of the drain 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 joint body 10 and the notch 37a formed in the mounting surface 30b of the spacer 30, so that when the joint body 10 or the spacer 30 is installed, the outer circumference of the flange portion 40b can be fitted into the notch 21b or the notch 37a.

[0058] When attaching an internal sub-pipe joint 1 to a drain pipe 3 connected by a flexible joint 40 attached to the inner wall of manhole 2, as shown in Figure 9(a), the cylindrical portion 40a of the flexible joint 40 is inserted from the inside of manhole 2 into a drain inlet hole 2h drilled in manhole 2 to match the position of the drain pipe 3, the flange portion 40b is fixed to the inner wall of manhole 2 with adhesive or the like, and then one end of the drain pipe 3 is pressed into the cylindrical portion 40a so that one end faces the inside of manhole 2.

[0059] Next, as shown in Figure 9(b), the notch 37a of the spacer 30, which is integrated with the joint body 10, is fitted into the flange portion 40b, and the mounting surface 30b is brought into contact with the inner wall of the manhole 2. Then, it is temporarily fixed to the inner wall of the manhole 2 with temporary fixing bolts KB inserted through the temporary fixing holes 23a and 33. This brings one end of the drain pipe 3 to face the drain inlets 19 and 31. At this time, since the joint body 10 is provided with gripping portions 25 on both sides, even when a straight pipe 4 or curved pipe 5 is attached to the joint body 10 and has a considerable weight, it is possible to align it relatively easily by gripping the gripping portions 25 from both sides. In addition, since the flange portion 40b is fitted into the notch 37a and the flange portion 40b is housed within the notch 37a, it is possible to bring the mounting surface 30b into contact with the inner wall of the manhole 2 even if the flange portion 40b is thick.

[0060] In this state, the spacer 30 and mounting part 21 are fixed to the inner wall of the manhole 2 using mounting means such as bolts B inserted through the four through holes 22 and 32. Then, the outer circumference of the spacer 30 is sealed with caulking material, thereby attaching the internal sub-pipe joint 1 to the inner wall of the manhole 2. Since the through holes 22 and 32 are elongated holes extending radially from the center, even if the fixing position of the mounting means such as bolts B is slightly off, it is possible to adjust and attach the internal sub-pipe joint 1 to the optimal position.

[0061] When installing to manhole 1 2a, the spacer 30 is not used. Instead, the notch 21b of the mounting portion 21 of the joint body 10 is fitted into the flange portion 40b, the mounting surface 21a is brought into contact with the inner wall of manhole 2, and then the mounting portion 21 is temporarily fixed to the inner wall of manhole 2 with temporary fixing bolts KB inserted through the temporary fixing holes 23a. Finally, the mounting portion 21 is fixed to the inner wall of manhole 2a with fixing means such as bolts B inserted through the four insertion holes 22.

[0062] Furthermore, although the above configuration involves temporarily fastening the manhole 2 to the inner wall using temporary fastening bolts KB, if the fitting strength of the flange portion 40b to the notches 37a and 21b is high, the temporary fastening may be performed solely by fitting the flange portion 40b to the notches 37a and 21b without using temporary fastening bolts KB.

[0063] Figure 10 shows the installation of an internal sub-pipe joint 1 to a drain pipe 3 connected by a flexible joint 50 attached to the outer wall of a 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 drain pipe 3 is press-fitted, and an annular flange portion 50b that extends outward from one end of the cylindrical portion 50a.

[0064] When attaching an internal sub-pipe joint 1 to a drain pipe 3 connected by a flexible joint 50 attached to the outer wall of manhole 2, as shown in Figure 10, the flange portion 50b of the flexible joint 50 is fixed to the outer wall of manhole 2 with adhesive or the like, in line with the drain inlet hole 2h drilled in manhole 2 to match the position of the drain pipe 3, and then one end of the drain pipe 3 is pressed into the cylindrical portion 50a, with the other end facing the inside of manhole 2.

[0065] Next, as shown in Figure 10, the mounting surface 30b of the spacer 30, which is integrated with the joint body 10, is brought into contact with the inner wall of the manhole 2. After aligning the position, it is temporarily fixed to the inner wall of the manhole 2 with temporary fixing bolts KB inserted through the temporary fixing holes 23a and 33. This brings one end of the drain pipe 3 to face the drain inlets 19 and 31.

[0066] In this state, the spacer 30 and the mounting part 21 are fixed to the inner wall of the manhole 2 using mounting means such as bolts B inserted through the four insertion holes 22 and 32, and then the outer circumference of the spacer 30 is sealed with caulking material, thereby attaching the internal sub-pipe joint 1 to the inner wall of the manhole 2.

[0067] When installing to manhole 1 2a, the spacer 30 is not used. Instead, the mounting surface 21a of the mounting portion 21 of the joint body 10 is brought into contact with the inner wall of the manhole 2a, and the mounting portion 21 is temporarily fixed to the inner wall of the manhole 2a with temporary fixing bolts (not shown) inserted through the temporary fixing holes 23a. Finally, the mounting portion 21 is fixed to the inner wall of the manhole 2a with fixing means such as bolts B inserted through the four insertion holes 22.

[0068] As shown in Figure 11(a), if the position facing the drain pipe 3 is higher than the bottom of the manhole 2, one end of the straight pipe 4, which has both ends cut to match the height of the drain pipe 3, is fitted into the sub-pipe connection part 13 of the internal sub-pipe joint 1 for connection, and the other end is fitted into the socket 5a of the curved pipe 5, which has a socket 5a on one side and an opening 5b on the other side for connection, so that the wastewater discharged from below the internal sub-pipe joint 1 is discharged through the straight pipe 4 and curved pipe 5 to the invert part 9 of the manhole 2.

[0069] Furthermore, as shown in Figure 11(b), if the position facing the drain pipe 3 is lower than the bottom of the manhole 2, the opening 5b of the curved pipe 5 can be fitted into the sub-pipe connection part 13 of the internal sub-pipe joint 1 to connect them, so that the wastewater discharged from below the internal sub-pipe joint 1 is discharged through the curved pipe 5 to the invert part 9 of the manhole 2.

[0070] In this case, by using a curved pipe 5 having an insertion end and a receiving end 5a at the other end, a common curved pipe 5 can be used whether the curved pipe 5 is connected to the internal sub-pipe joint 1 via a straight pipe 4 or whether the curved pipe 5 is connected directly to the internal sub-pipe joint 1.

[0071] [Regarding the effects and benefits] In this embodiment, the internal sub-pipe joint 1 has a cylindrical vertical pipe section 11 extending vertically at one end. The width dimension of the upper part 11a of the vertical pipe section 11 is formed to be longer than the depth dimension, ensuring sufficient volume within the vertical pipe section 11 into which wastewater flows from the drain pipe 3. Furthermore, the width dimension of the lower part 11b of the vertical pipe section 11 gradually narrows towards the drain outlet 13a below, forming a drain outlet 13a that is short in both the width and depth directions. This allows a sub-pipe with a smaller diameter than the vertical pipe section 11 (for example, a straight pipe 4, a curved pipe 5, etc.) to be installed closer to the inner wall of the manhole 2, thereby securing more working space inside the manhole 2.

[0072] In this embodiment, the upper part 11a of the vertical pipe section 11 has a width dimension greater than the depth dimension, and the width and depth dimensions do not change from the upper end to the lower end, forming a roughly elliptical cross-section. The lower part 11b of the vertical pipe section 11 is formed in a tapered shape where the width dimension gradually narrows downwards from a position below the lower end of the drain inlet 19, while the depth dimension remains the same and does not change downwards, and the width and depth dimensions are reduced to a circular cross-section 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 section 11 The above effect can be achieved if the pipe section is formed to be longer than its depth dimension, and the width dimension of the lower part 11b of the vertical pipe section 11 gradually narrows toward the drain outlet 13a below. The upper part 11a of the vertical pipe section 11 does not necessarily have to be substantially elliptical in cross-section, nor does the lower part 11b of the vertical pipe section 11 have to be reduced in diameter from substantially elliptical to circular in cross-section toward the bottom. For example, the shape before reduction may be other than substantially elliptical in cross-section, and the shape after reduction may be other than substantially circular in cross-section. Furthermore, the depth dimension of the lower part 11b of the vertical pipe section 11 may gradually narrow toward the bottom. Furthermore, the width dimension of the lower part 11b of the vertical pipe section 11 may gradually narrow toward the bottom from a position above the lower end of the drain inlet 19. Furthermore, the shape of the lower part 11b of the vertical pipe section 11, which is formed to gradually narrow towards the lower drain outlet 13a, may be any of the following: a shape that narrows at a constant slope, a shape that becomes steeper as it goes downwards, or a shape that becomes gentler as it goes downwards.

[0073] Furthermore, in this embodiment, the width dimension of the lower part 11b of the vertical pipe section 11 gradually narrows towards the drain outlet 13a, while the depth dimension does not change towards the drain outlet 13a. Therefore, the shape of the lower part 11b of the vertical pipe section 11 does not become complex.

[0074] Furthermore, in this embodiment, the lower part 11b of the vertical pipe section 11 gradually narrows in width from a roughly elliptical cross-section towards the roughly circular cross-section of the drain outlet 13a, resulting in a smoother drainage flow.

[0075] Furthermore, in this embodiment, the width dimension of the lower part 11b of the vertical pipe section 11 is formed to gradually narrow from a position below the lowest end of the drainage inlet 19 toward the drainage outlet 13a. As a result, sufficient vertical volume of the vertical pipe section 11 can be secured, and even if the amount of wastewater flowing into the drainage inlet 19 temporarily increases, it can be discharged to the drainage outlet 13a with ample margin.

[0076] In this embodiment, an upper inspection opening 12 is formed on the upper surface of the vertical pipe section 11. The upper inspection opening 12 is formed so that its width is greater than its depth, just like the upper part 11a of the vertical pipe section 11. This minimizes blind spots within the vertical pipe section 11 from the upper inspection opening 12. In this embodiment, the shape of the upper inspection opening 12 is the same as the inner circumference shape of the upper part 11a of the vertical pipe section 11. However, it is not necessary for the shape to be identical. As long as the width is greater than the depth, just like the upper part 11a of the vertical pipe section 11, the same effect as described above will be achieved.

[0077] In this embodiment, the internal sub-pipe joint 1 has a cylindrical vertical pipe section 11 extending vertically at one end and an extension pipe section 18 extending from the vertical pipe section 11 to the drainage inlet 19. A recessed portion 20 is formed on the inner bottom surface of the extension pipe section 18, sloping downward toward the inner surface 11c of the vertical pipe section 11. By allowing wastewater flowing into the extension pipe section 18 to flow out to the vertical pipe section 11 through the recessed portion 20, wastewater can be prevented from accumulating in the extension pipe section 18, thereby suppressing the impact on drainage performance by foreign matter and conveyed materials contained in the accumulating wastewater.

[0078] In particular, in this embodiment, in order to facilitate the removal of the molded product from the mold during injection molding, the inner circumferential surface of the extension pipe section 18 is slightly widened in diameter along its entire circumference from the vertical pipe section 11 at one end toward the drain inlet 19 at the other end. As a result, drainage tends to accumulate inside the extension pipe section 18. However, by forming a recessed portion 20 on the inner bottom surface of the extension pipe section 18 that slopes downward toward the inner circumferential surface 11c of the vertical pipe section 11, it is possible to prevent drainage from accumulating inside the extension pipe section 18, even though the inner bottom surface of the extension pipe section 18 is slightly widened in diameter toward the drain inlet 19.

[0079] In this embodiment, the inner circumferential surface of the extension pipe section 18 is shaped to slightly increase in diameter from the vertical pipe section 11 at one end towards the drainage inlet 19 at the other end along its entire circumference. However, the inner circumferential surface of the extension pipe section 18 may be shaped to have the same diameter from the vertical pipe section 11 at one end towards the drainage inlet 19 at the other end, or the inner circumferential surface of the extension pipe section 18 may be shaped to increase in diameter from the drainage inlet 19 at the other end towards the vertical pipe section 11 at one end.

[0080] Furthermore, in this embodiment, the angle of inclination of the bottom surface of the recessed portion 20 gradually becomes steeper from the extended pipe portion 18 toward the inner circumferential surface 11c of the vertical pipe portion 11, so that the wastewater that flows into the recessed portion 20 can be smoothly discharged.

[0081] Furthermore, in this embodiment, a recessed portion 20 is formed in the inner bottom surface of the extended pipe portion 18, that is, in a part of the area near the center of the lower half or less of the inner surface of the extended pipe portion 18. Since wastewater tends to collect in the recessed portion 20, wastewater that flows into the recessed portion 20 can be smoothly discharged even when the wastewater flow rate is low.

[0082] In this embodiment, the width dimension of the upper part 11a of the vertical pipe section 11 is formed to be longer than the depth dimension, and the width dimension of the lower part 11b of the vertical pipe section 11 is formed to gradually narrow toward the drain outlet 13a below. However, the above effect can be achieved as long as the configuration includes at least a cylindrical vertical pipe section 11 extending in the vertical direction and an extension pipe section 18 extending from the vertical pipe section 11 to the drain inlet 19, and a recessed portion 20 is formed on the inner bottom surface of the extension pipe section 18, sloping downward toward the inner surface 11c of the vertical pipe section 11. Therefore, it is not necessarily required that the width dimension of the upper part 11a of the vertical pipe section 11 be longer than the depth dimension, nor is it necessary that the width dimension of the lower part 11b of the vertical pipe section 11 gradually narrow toward the drain outlet 13a below. For this reason, the vertical pipe section 11 may be formed in a cylindrical shape with a substantially circular cross-section. Furthermore, the lower part 11b of the vertical pipe section 11 may not be configured to be reduced in diameter toward the drain outlet 13a.

[0083] In this embodiment, an inspection port 14a is formed in the vertical pipe section 11 at a position opposite the drainage inlet 19. Since the inner diameter of the inspection port 14a is larger than the inner diameter of the drainage inlet 19, the inside of the drainage inlet 19 can be viewed broadly from the inspection port 14a.

[0084] In this embodiment, gripping portions 25 capable of gripping the internal sub-pipe joint 1 are provided on both sides of the joint body 10. By gripping the gripping portions 25 of the internal sub-pipe joint 1, the internal sub-pipe joint 1 can be placed in the manhole 2 in a stable state. In this embodiment, gripping portions 25 are provided on both sides of the joint body 10, but it is also possible to have a configuration with only one gripping portion. Alternatively, holes into which a hand can be inserted may be provided on the upper left and right sides, or on one end of the upper part of the vertical pipe portion 11, and these may also serve as gripping portions.

[0085] In this embodiment, a water-stopping ring 13b is attached to the sub-pipe connection section 13 having a drain outlet 13a, and an annular protrusion 13d that protrudes upward is formed on the water-stopping ring 13b, which functions as a mechanism to prevent the pipe inserted from below from coming loose, so that the pipe can be easily connected to the drain outlet 13a.

[0086] Furthermore, in this embodiment, the sub-pipe connection portion 13 has an expanded diameter portion 13e that tapers upward, allowing the insertion angle of the straight pipe 4 or curved pipe 5 to be adjusted within the range of the inner diameter of the expanded diameter portion 13e even after the spool of the straight pipe 4 or curved pipe 5 has been inserted into the sub-pipe connection portion 13. However, the sub-pipe connection portion 13 may also be configured without the expanded diameter portion 13e. Alternatively, the sub-pipe connection portion 13 may be a simple socket without a water-sealing ring 13b. In this case, the sub-pipe can be inserted into the socket and fixed with adhesive.

[0087] In this embodiment, the joint body 10 has a mounting portion 21 formed therein for attaching the internal sub-pipe joint 1 to the inner wall of the manhole 2. The mounting portion 21 has an insertion hole 22 through which a mounting 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. After positioning the internal sub-pipe joint 1 by temporarily fixing it using the temporary fixing hole 23a, the mounting portion 21 can be attached to the inner wall of the manhole 2 with a mounting member.

[0088] Furthermore, in this embodiment, indicator protrusions 24a and 24b are formed on the mounting portion 21 to indicate the center position of the drain inlet 19, allowing workers to confirm the center position of the drain inlet 19, which is not visible from the worker's side when installing it on the inner wall of the manhole 2. In this embodiment, the indicators for the center position of the drain inlet 19 are formed by creating protrusions on the mounting portion 21, but the indicators for the center position of the drain inlet 19 may also be formed by creating grooves. The position of the indicators may also be on the side of the mounting portion 21.

[0089] In this embodiment, a spacer 30 corresponding to the shape of the inner wall of the manhole 2 can be attached to the mounting portion 21, making it possible to install a common internal sub-pipe joint 1 in manholes 2 with different inner wall shapes.

[0090] Furthermore, in this embodiment, the spacer 30 has a locking piece 35 that engages with the mounting portion 21 of the joint body 10. The mounting portion 21 is locked by the locking piece 35, and the spacer can be installed on the inner wall of the manhole 2 in an integrated state with the mounting portion 21, thus enabling efficient installation of the internal sub-pipe joint 1.

[0091] In this embodiment, two pairs of locking pieces 35, 35 are provided approximately in the 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 the spacer 30 can be locked to the mounting portion 21 of the joint body 10, and the same effect can be achieved. Alternatively, a separate locking fitting may be attached to the groove portion of the spacer 30, and the spacer 30 may be locked to the mounting portion 21 of the joint body 10 via the locking fitting. Furthermore, without using locking pieces or locking fittings, the protruding portions 36a, 36b, and 36c may be fitted into the notches 21b, grooves 21c, and grooves 21d formed on the mounting surface 21a, and the force of the protruding portions 36a, 36b, and 36c being clamped will cause the spacer 30 to become integrated with the mounting portion 21. Alternatively, without using locking pieces or locking fittings, the mounting portion 21 may be fitted into a receiving portion 34 formed on the spacer 30, and the force of being held by the receiving portion 34 may cause the spacer 30 to become integrated with the mounting portion 21. Or, an elastic material such as a rubber ring for preventing slippage may be attached inside the receiving portion 34, and the mounting portion 21 fitted into the receiving portion 34 may be held by its elastic force, causing the spacer 30 to become integrated with the mounting portion 21. In addition, multiple inward-facing ribs may be provided on the receiving portion 34, and the force of being held by the multiple ribs on the mounting portion 21 fitted into the receiving portion 34 may cause the spacer 30 to become integrated with the mounting portion 21.

[0092] Alternatively, the structure may be designed so that the spacer 30, such as a locking piece, and the mounting portion 21 are not integrated, and the spacer 30 and the joint body 10 are attached separately. In this case, for example, the spacer 30, which fits the inner diameter of the manhole 2, is temporarily fixed to the inner wall of the manhole 2 with temporary fixing bolts or adhesive, and then the joint body 10 is positioned appropriately relative to the temporarily fixed spacer 30 and fixed together with the spacer 30 to the inner wall of the manhole 2 using mounting members such as bolts.

[0093] Furthermore, in this embodiment, the spacer 30 has temporary fixing holes 33 formed at positions corresponding to the temporary fixing holes 23a formed in the mounting portion 21, so that even when attaching the internal sub-pipe joint 1 via the spacer 30, the internal sub-pipe joint 1 can be temporarily fixed using the temporary fixing holes 23a.

[0094] Furthermore, by making the outer shape of the spacer 30, including the shape of the temporary fixing portion 23, approximately the same as the outer diameter of the mounting portion 21, the caulking work when attaching the internal sub-pipe joint 1 to the inner wall of the manhole 2 via the spacer 30 becomes easier.

[0095] In this embodiment, the mounting surface 21a of the mounting portion 21 has double annular grooves 21c and 21d. When installed on the inner wall of the manhole 2, a water-sealing packing P is placed in the groove 21d to provide a seal. The joint body 10 can be made lighter by including the groove 21c, which is not used for sealing. Alternatively, both grooves 21c and 21d may be sealed.

[0096] Furthermore, 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 contained within the notch 21b.

[0097] In this embodiment, the mounting surface 30b of the spacer 30, which is installed on the inner wall of the manhole 2, has double annular grooves 37b and 37c. When installed on the inner wall of the manhole 2, a water-sealing packing P is placed in the groove 37c to seal it, and the spacer 30 can be made lighter by including the groove 37b which is not used for sealing. Alternatively, both grooves 37b and 37c may be sealed.

[0098] Furthermore, in this embodiment, an annular notch 37a is formed on the mounting surface 30b of the spacer 30, which is installed on the inner wall of the manhole 2, 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 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 contained within the notch 37a.

[0099] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0100] [Regarding Variant 1] In the internal sub-pipe joint 1 of this embodiment, the vertical pipe section 11 was integrally molded. However, in the internal sub-pipe joint 101 of the modified example 1, as shown in Figure 12(a), the shape of the vertical pipe section 111 is almost the same as that of the vertical pipe section 11, but it is integrally molded with the joint body 110 and has a two-piece structure consisting of an upper vertical pipe section 111a that has no change in width and depth dimensions, and a lower vertical pipe section 111b that is molded separately from the upper vertical pipe section 111a and has no change in depth dimension but gradually narrows in width. The structure other than the vertical pipe section 111 is the same as that of the internal sub-pipe joint 1.

[0101] The lower vertical pipe section 111b has a socket 111c formed at its upper end into which the lower end of the upper vertical pipe section 111a can be fitted, and the lower end of the upper vertical pipe section 111a can be fitted into the socket 111c to connect them together.

[0102] 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 sockets of the straight pipe 4 and curved pipe 5 can be connected to the sub-pipe connection section 13 integrally formed at the lower end of the lower vertical pipe section 111b. Alternatively, as shown in Figure 12(c), it is also possible to directly connect the sockets 104a and 105a of the elliptical straight pipe 104 and elliptical curved pipe 105, which have the same cross-sectional shape as the upper vertical pipe section 111a and have sockets 104a and 105a formed at one end into which the lower end of the upper vertical pipe section 111a can be fitted, without using the lower vertical pipe section 111b.

[0103] Furthermore, although not specifically shown in the figures, it is preferable to provide a water-sealing ring in the socket 111c that functions as a retaining mechanism, similar to the sub-pipe connection part 13. With this configuration, the lower end of the upper vertical pipe section 111a can be easily connected to the socket 111c. Also, similar to the sub-pipe connection part 13, it is preferable that the socket 111c has an enlarged diameter section that tapers in the opposite direction to the opening of the socket 111c. With this configuration, even after inserting the lower end of the upper vertical pipe section 111a into the socket 111c, the insertion angle of the lower end of the upper vertical pipe section 111a can be adjusted within the range of the inner diameter of the enlarged diameter section. Note that the socket 111c may also be a simple socket without a water-sealing ring. In this case, the lower end of the upper vertical pipe section 111a can be inserted into the socket 111c and fixed with adhesive.

[0104] Furthermore, although the internal sub-pipe joint 101 has a socket 111c formed at the upper end of the lower vertical pipe section 111b, it is also possible to have a socket 111c not formed at the upper end of the lower vertical pipe section 111b, and instead have a socket (not shown) formed at the lower end of the upper vertical pipe section 111a into which the upper end of the lower vertical pipe section 111b can be fitted, and the upper end (insertion) of the lower vertical pipe section 111b can be fitted into this socket to connect them together. With such a configuration, the insertion ports of straight pipes 104 and curved pipes 105, which have the same cross-sectional shape as the upper vertical pipe section 111a, can be directly connected.

[0105] Furthermore, in this configuration, it is preferable to provide a water-stopping ring that functions as a retaining mechanism, similar to the sub-pipe connection part 13, in the socket formed at the lower end of the upper vertical pipe section 111a. With this configuration, the upper end of the lower vertical pipe section 111b can be easily connected to the socket formed at the lower end of the upper vertical pipe section 111a. Also, it is preferable that the socket formed at the lower end of the upper vertical pipe section 111a has an enlarged diameter section that tapers in the opposite direction to the opening of the socket, similar to the sub-pipe connection part 13. With this configuration, even after inserting the upper end of the lower vertical pipe section 111b, the straight pipe 104, or the curved pipe 105 into the socket, the insertion angle of the upper end of the lower vertical pipe section 111b, the straight pipe 104, or the curved pipe 105 can be adjusted within the range of the inner diameter of the enlarged diameter section. Furthermore, the socket formed at the lower end of the upper vertical pipe section 111a may be a simple socket without a water-sealing ring. In this case, the straight pipe 104 and the curved pipe 105 can be inserted into the socket and fixed with adhesive.

[0106] [Regarding Variation 2] In the modified example 2 of the internal sub-pipe joint 201, as shown in Figures 13(a) and (b), the vertical pipe section 211 has a width dimension greater than its depth dimension, and is formed in a substantially elliptical cross-section in which the width and depth dimensions do not change from the upper end to the lower end. Its upper end is open, forming an upper inspection port 212, and its lower end is also open, forming a lower outlet 213. The cross-sectional shape of the vertical pipe section 211 is the same as the cross-sectional shape of the upper part 11a of the vertical pipe section 11 of the internal sub-pipe joint 1. The structure other than the vertical pipe section 111 is the same as that of the internal sub-pipe joint 1.

[0107] A socket 214 is formed at the lower end of the vertical pipe section 211 into which the upper end of the vertical pipe section 11 of the internal sub-pipe joint 1 and the upper end of the internal sub-pipe joint 201 can be fitted. The upper end of the vertical pipe section 11 of the internal sub-pipe joint 1 or the upper end of the internal sub-pipe joint 201 can be fitted into the socket 214 and connected to the upper end of the vertical pipe section 11 of the internal sub-pipe joint 1 or the upper end of the vertical pipe section 211 of the internal sub-pipe joint 201.

[0108] As a result, as shown in Figures 13(a) and 13(b), it becomes possible to install one or more internal sub-pipe fittings 201 and internal sub-pipe fittings 1 vertically connected to multiple drain pipes 3, 3 that are vertically connected to the inner wall of manhole 2. In this way, wastewater discharged from multiple drain pipes 3, 3 can be collected.

[0109] Furthermore, although not specifically shown in the figures, it is preferable to provide a water-sealing ring in the socket 214 that functions as a retaining mechanism, similar to the sub-pipe connection part 13. With this configuration, the upper end of the vertical pipe section 11 of the internal sub-pipe joint 1 can be easily connected to the socket 214. Also, similar to the sub-pipe connection part 13, it is preferable that the socket 214 has an enlarged diameter section that tapers in the opposite direction to the opening of the socket 214. With this configuration, even after inserting the upper end of the vertical pipe section 11 of the internal sub-pipe joint 1 into the socket 214, the insertion angle of the upper end of the vertical pipe section 11 can be adjusted within the range of the inner diameter of the enlarged diameter section.

[0110] [Regarding Variation 3] In the modified example 3 of the internal sub-pipe joint 301, as shown in Figures 14(a) to (c) ((b) and (c) are DD cross-sectional views of (a)), instead of the insertion hole 22 formed in the mounting portion 21 of the internal sub-pipe joint 1, insertion holes 302 are formed at the four corners of the mounting portion 321, consisting of a large-diameter circular hole and a small-diameter elongated hole extending upward from this circular hole. The large-diameter circular hole is sized to allow the head of the bolt B to pass through, and the width of the elongated hole is narrower than the head of the bolt B and sized to allow the shaft of the bolt B to pass through. In addition, insertion holes 303, which are the same shape as the insertion holes 302, are formed at positions corresponding to the insertion holes 302 of the spacer 330.

[0111] When installing the internal sub-pipe joint 301 of Modification 3 into the manhole 2, the position of bolt B is determined by bringing the mounting surface 330b of the spacer 330, which is integrated with the joint body 310, into contact with the inner wall of the manhole 2 and aligning the position. At this time, temporary fastening to the inner wall of the manhole 2 may also be performed using temporary fastening bolts (not shown) inserted through temporary fastening holes 23a and 33.

[0112] Then, bolts B are driven into the inner wall of manhole 2 at predetermined positions. After that, as shown in Figure 14(b), the heads of bolts B are inserted through the circular holes 302 and 303, and the mounting surface 330b of the spacer 330, which is integrated with the joint body 310, is brought into contact with the inner wall of manhole 2. As shown in Figure 14(c), the entire inner sub-pipe joint 301 is slid downward, so that the heads of bolts B are supported around the elongated hole 302 in the mounting portion 321, and the inner sub-pipe joint 301 is attached to the inner wall of manhole 2. Furthermore, when installing to manhole 1 2a, the spacer 330 is not used. The mounting surface 321a of the mounting portion 321 of the joint body 310 is brought into contact with the inner wall of manhole 2a, and the position of bolt B is determined by aligning it. Bolt B is then driven into the determined position on the inner wall of manhole 2a. After that, the head of bolt B is inserted through the circular hole of the insertion hole 302, bringing the mounting surface 321a of the mounting portion 321 of the joint body 310 into contact with the inner wall of manhole 2a, and the entire inner sub-pipe joint 301 is slid downward.

[0113] This makes it possible to drive in bolt B with the internal sub-pipe joint 301 temporarily separated from the inner wall of manhole 2.

[0114] [Regarding Variation 4] In the modified example 4, the internal sub-pipe joint 401, as shown in Figures 15(a) and 15(b) (where (b) is a cross-sectional view of (a)), the side wall of the vertical pipe section 411 is connected to the mounting section 421, and a part of the mounting section 421 is formed in a substantially semi-elliptical cross-section that constitutes the wall of the vertical pipe section 411 on the drain inlet 419 side. Furthermore, the vertical pipe section 411 does not have an extension pipe section 18 like the joint body 10 of the internal sub-pipe joint 1, and the drain inlet 419 is formed directly in the vertical pipe section 411. The lower part 11b of the vertical pipe section 411 is formed in a tapered shape, with the width gradually narrowing downwards from a position below the lower end of the drain inlet 419, while the depth remains substantially the same and does not change downwards. The width and depth are reduced to a circular cross-section smaller than the outer diameter of the drain pipe 3, and the sub-pipe connection section 413 is formed below it.

[0115] With this configuration, a portion of the mounting section 421 forms the wall on the drainage inlet 419 side of the vertical pipe section 411, eliminating the need for an extension pipe section connected to the mounting section 421. This reduces the amount of material used, and also reduces the depth of the joint body 410, allowing for more workspace inside the manhole 2 where the internal sub-pipe joint 401 is installed.

[0116] [Regarding Variation 5] In the internal sub-pipe joint 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 portion 18 in the joint body 10, with a shape that extends toward the inner surface of the vertical pipe portion 11. However, as shown in Figure 16(b), a recessed portion 20' is formed in a shape that extends toward the inner surface of the vertical pipe portion 11 over the entire inner bottom surface of the extended pipe portion 18 in the joint body 10.

[0117] [Regarding Variation 6] In this embodiment, the spacer 30 is integrally molded, but the spacer 630 in the modified example 6 has a two-piece structure that is separated into upper and lower parts, as shown in Figure 17. As shown in Figures 17(a) and 17(b), the spacer 630 consists of an upper spacer member 631 and a lower spacer member 632.

[0118] The upper spacer member 631 has a notch 631a formed on its lower mounting surface side, and a protrusion 631b is formed at the lower end of the notch 631a, projecting away from the joint body 10. On the other hand, the lower spacer member 632 has a notch 632a formed on its upper non-mounting surface side, which is substantially the same shape as the notch 631a, and a recess 632b is formed at the lower end of the notch 532a, which is substantially the same shape as the protrusion 631b. In addition, the lower spacer member 632 has two pairs of locking pieces 635, 635, which are the same shape as the spacer 30, formed on both the left and right sides, facing toward the joint body 10.

[0119] Then, as shown in Figure 17(c), by assembling the notch 631a of the upper spacer member 631 into the notch 632a of the lower spacer member 632, the convex portion 631b fits into the concave portion 632b, forming a single spacer 630.

[0120] Furthermore, since 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, 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 sandwiched between the upper non-mounting surface side of the lower spacer member 632 and the mounting portion 21, and the convex portion 631b is fitted into the concave portion 632b, and separation in the vertical direction is also restricted, the upper spacer member 631, the lower spacer member 632 and the joint body 10 are assembled as a single unit, and the upper spacer member 631 and the lower spacer member 632 do not separate.

[0121] With this configuration, the spacer 630 has a two-piece structure that can be separated vertically, so even if the opening 6 of the manhole 2 is narrow, the spacer 630 can be easily brought inside by dividing it. In the modified example 6, the spacer 630 has a two-piece structure that can be separated vertically, but it may also be a two-piece structure that can be separated horizontally, or a configuration that can be divided into three or more pieces, and in such configurations as well, the spacer 630 can be easily brought inside the manhole 2 by dividing it.

[0122] [Regarding 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. With 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]

[0123] 1. Internal sub-pipe joint 2 Manholes 3 Drain pipe (inflow pipe) 10 Fitting body 11 Vertical pipe section 13. Sub-pipe connection 13a Drainage outlet (outlet) 14 Inspection hatch section 14a Inspection hatch 15 Inspection port cover 18 Extension pipe section 19 Drainage inlet (inlet) 20 Notch 21 Mounting part 30 Spacers

Claims

1. An internal sub-pipe joint installed on the inner wall of a manhole, The inlet through which wastewater flows in from the inlet pipe, A vertical pipe section that allows wastewater flowing in from the aforementioned inlet to be discharged from the outlet below, Equipped with, The upper part of the vertical pipe section has a width dimension that does not change vertically along the circumferential direction of the inner wall of the manhole, and the lower part of the vertical pipe section consists of a tapered section in which the width dimension is gradually narrowed from the lowest end of the inlet toward the outlet, and a connecting section extending from the tapered section toward the outlet, the connecting section being formed to gradually widen sequentially from the top toward the outlet downwards and then tapering toward narrowing, and a watertight ring is provided on the inner surface of the lower end of the connecting section. An internal sub-pipe joint characterized by the following features.

2. The lower part of the vertical pipe section is formed such that the width dimension is approximately the same as the depth dimension extending inward into the inner wall of the manhole, and the width dimension is formed toward an outlet with a roughly circular cross-section. The internal sub-pipe joint according to feature 1.

3. The aforementioned vertical pipe section consists of an upper vertical pipe section whose width dimension does not change from top to bottom, and a lower vertical pipe section which is molded separately from the upper vertical pipe section and connected to the lower part of the upper vertical pipe section. An internal sub-pipe joint according to claim 1 or 2, characterized by the above.

4. An inspection port is formed in the vertical pipe section at a position opposite the inlet. The inspection opening is larger than the inner diameter of the inlet pipe. An internal sub-pipe joint according to any one of the features 1 to 3.

5. The vertical pipe section is provided with temporary fixing holes for temporarily securing it to the inner wall of the manhole. An internal sub-pipe joint according to any one of the features 1 to 4.

6. The internal sub-pipe joint is provided with a gripping portion capable of gripping it. An internal sub-pipe joint according to any one of claims 1 to 5.

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