Concentric and sealing structure of nodular cast iron pipe jacking concrete protection layer pouring mold

Abstract

The utility model discloses a concentric and sealing structure of a nodular cast iron jacking pipe concrete protection layer pouring mold, and relates to the field of nodular cast iron jacking pipes. The device comprises a spigot end and a socket end, the spigot end and the socket end are assembled and connected with a pouring mold through bolts, positioning stop blocks are evenly welded to the periphery of the inner wall of the spigot end, internal rotation positioning bolts are additionally arranged on the inner edge of an inverted cone of the socket end in the circumferential direction, and two annular grooves are formed in the socket end in advance. And sealing strips are embedded in the two annular grooves. The casting mold solves the problems of eccentricity and poor sealing performance during assembly of an existing casting mold, ensures concentricity and consistency during production and mold assembly of the nodular cast iron jacking pipe through the positioning stop block welded at the spigot end and the positioning bolt movably arranged at the socket end, ensures uniform thickness of a cast concrete protective layer, and improves the production efficiency. The embedded sealing strip is mounted at the socket end of the pouring mold, so that a sealing effect is achieved, and the sealing strip is detachably arranged, so that the sealing strip is convenient to replace.

Description

Technical Field

[0001] The utility model relates to the field of ductile iron jacking pipes, in particular to a concentric and sealing structure for a casting mold of a concrete protective layer of a ductile iron jacking pipe. Background Art

[0002] An important application scenario of ductile iron pipes is trenchless technology. Trenchless construction technology is used to lay and renew ductile iron pipelines without excavating the ground surface. Trenchless construction has the characteristics of not damaging the environment and not affecting traffic, and can carry out the construction of various underground pipelines in some areas where excavation construction cannot be implemented, such as bustling urban areas, historical site protection areas, crop and vegetation protection areas, and crossing highways, railways, buildings, rivers and lakes, etc. Common trenchless construction technologies are mainly divided into the traction method and the pipe jacking method. The casting of the concrete protective layer of the pipe jacking is completed through a mold, and the casting production process is roughly as follows: First, assemble the ductile iron pipe and the mold. The mold consists of a mold body, a base and a casting cap. Then, use a crane and a pipe turning machine to make the pipe stand vertically in the casting pit. At this time, the socket is at the bottom, and the bottom support of the mold catches the socket, and the spigot is at the top, which is convenient for installing the casting cap. Finally, install the casting cap and start casting the concrete layer. During the casting process, vibration compaction is accompanied to ensure that the concrete layer is dense. When assembling the pipe jacking mold, the concentricity between the ductile iron pipe and the pipe jacking casting mold is crucial for the appearance quality of the concrete layer.

[0003] However, due to the requirements for the thickness of the concrete layer of ductile iron jacking pipes of various diameters, and the tolerance range of the size of the socket D1 during the production of ductile iron jacking pipes, it is very easy for the two to be eccentric when assembling the casting mold. At the same time, because the ductile iron pipe itself is relatively heavy, it is difficult to manually adjust, resulting in uneven thickness of the cast concrete layer in the circumferential direction, affecting the appearance and use. Moreover, the base of the conventional mold in use is connected to the mold body by bolts, and the sealing performance is not good. During the casting and compaction of the concrete layer, slurry bubbling is very likely to occur, resulting in obvious pitted surfaces and exposed aggregates at the socket end of the concrete layer, with a large amount of repair work, affecting the quality and production efficiency of ductile iron jacking pipes. Therefore, it does not meet the existing requirements, and for this reason, we propose a concentric and sealing structure for a casting mold of a concrete protective layer of a ductile iron jacking pipe. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a concentric and sealing structure for a casting mold of a concrete protective layer of a ductile iron jacking pipe, which has the characteristics of concentric positioning and sealing, and solves the problems in the prior art.

[0005] To achieve the above object, the present utility model provides the following technical solution: A concentric and sealing structure for a pouring mold of a ductile iron jacking pipe concrete protective layer, comprising a socket end and a spigot end. Both the socket end and the spigot end are assembled and connected to the pouring mold through bolts. Positioning blocks are evenly welded around the inner wall of the socket end, and internal rotation positioning bolts are installed circumferentially on the inner edge of the inverted cone of the spigot end. Two annular grooves are preset in the spigot end, and sealing strips are embedded in both of the two annular grooves.

[0006] Preferably, the positioning blocks are made of carbon steel and have a triangular structure.

[0007] Preferably, a jacking flange is pre-welded on the socket end, and the positioning blocks are in contact with the outer edge of the jacking flange until they touch.

[0008] Preferably, the positioning blocks are evenly distributed on the circumferential surface of the inner wall of the socket end, and the number of positioning blocks is set correspondingly according to the size of the ductile iron jacking pipe.

[0009] Preferably, the positioning bolts are made of carbon steel, the number of positioning bolts is not less than 4, and the positioning bolts are evenly distributed at a 90° angle in the circumferential direction of the inner edge of the inverted cone of the spigot end of the pouring mold.

[0010] Preferably, the screwing depth of the positioning bolts is 2 mm - 5 mm.

[0011] Preferably, the sealing strips are detachably arranged, and the cross-section of the sealing strips is circular.

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0013] 1. For the concentric and sealing structure of the pouring mold of the ductile iron jacking pipe concrete protective layer of the present utility model, the concentric positioning design of the spigot end and the socket end of the pouring mold is simple and convenient to use. Among them, the concentric positioning design of the socket end is the positioning blocks welded at fixed positions. During use, no installation operation is required. During mold assembly, the positioning blocks and the jacking flange pre-welded on the socket end are directly fitted, so as to accurately position. And the concentric design of the spigot end is the movable positioning bolts. The positioning bolts can freely adjust the screwing-in size according to different size requirements to ensure the concentricity of the spigot end. The design of the movable positioning bolts for the spigot end positioning ensures that the screwing-in positioning size is flexible and variable, and can adapt to the situation where the d3 values of ductile iron jacking pipes of the same caliber fluctuate differently.

[0014] 2. The concentric and sealing structure of the pouring mold for the concrete protective layer of the ductile iron jacking pipe of the present utility model has a simple sealing design at the bottom of the socket end. When assembling the vertical pipes of the mold, due to its own weight, the socket surface of the ductile iron jacking pipe presses tightly on the inner sealing strip to form an inner seal, and the end face of the socket end of the pouring mold presses tightly on the outer sealing strip to form an outer seal. When concrete is poured from the spigot end accompanied by vibration, it can prevent the leakage of cement slurry at the bottom, thus ensuring good apparent quality of the concrete layer at the socket of the ductile iron jacking pipe. The sealing design is simple to use and maintain. Usually, only cleaning is required. When the sealing strip is deformed or damaged, clean the groove and replace it with a new sealing strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the spigot end positioning block of the present utility model;

[0016] Figure 2 It is a schematic diagram of the socket end positioning bolt of the present utility model;

[0017] Figure 3 It is a schematic diagram of the socket end sealing strip of the present utility model;

[0018] Figure 4 It is a schematic diagram of the outer diameter dimensions of the socket and spigot of the ductile iron jacking pipe of the present utility model.

[0019] In the figure: 1, positioning block; 2, spigot end; 3, socket end; 4, positioning bolt; 5, annular groove; 6, sealing strip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0021] To solve the technical problems that due to the requirements for the thickness of the concrete layer of ductile iron jacking pipes of various calibers and the tolerance range of the d1 dimension of the socket during the production of ductile iron jacking pipes, it is extremely easy for the two to be eccentric when assembling the pouring mold. At the same time, due to the relatively heavy weight of the ductile iron jacking pipe itself, it is very difficult to manually adjust, resulting in uneven thickness of the concrete layer in the circumferential direction after pouring, affecting the appearance and use. Moreover, the base of the conventional pouring mold in use and the mold body are connected by bolts, and the sealing performance is not good. During the pouring and compaction of the concrete layer, it is very easy to have the phenomenon of slurry bubbling, thus affecting the quality and production efficiency of the ductile iron jacking pipe. Please refer to Figures 1 - 4 , the following technical solutions are provided in this embodiment:

[0022] A concentric and sealed structure for a pouring mold of a ductile iron jacking pipe concrete protective layer, including a socket end 2 and a spigot end 3. Both the socket end 2 and the spigot end 3 are assembled and connected to the pouring mold through bolts (the socket end 2 is the pouring cap of the pouring mold, and the spigot end 3 is the base of the pouring mold. The pouring mold is composed of a mold body, a base, and a pouring cap). Positioning blocks 1 are evenly welded around the inner wall of the socket end 2. Inner rotating positioning bolts 4 are installed circumferentially on the inner edge of the inverted cone of the spigot end 3. Two annular grooves 5 are preset in the spigot end 3, and sealing strips 6 are embedded in both of the two annular grooves 5.

[0023] Specifically, the socket end 2, the spigot end 3 and the pouring mold are assembled and connected using bolts. Positioning blocks 1 are evenly welded around the inner wall of the socket end 2 of the pouring mold. When installing the ductile iron jacking pipe, the positioning blocks 1 and the jacking flange pre-welded and fixed to the socket end 2 of the pouring mold naturally adhere closely, thus ensuring the concentricity of the socket end 2. The concentricity of the spigot end 3 is achieved by the inner rotating positioning bolts 4 installed circumferentially on the inner edge of the inverted cone of the spigot end 3. According to the measured value of the pipe source d3 dimension, the screwing-in values of all positioning bolts 4 are adjusted. During mold assembly, the d3 surface of the ductile iron jacking pipe socket and the positioning bolts 4 are tightened, thus ensuring the concentricity of the spigot end 3. Two annular grooves 5 are opened along the circumferential direction on the inner lower surface of the spigot end 3 of the pouring mold, and sealing strips 6 are embedded in both of the two annular grooves 5. After the vertical pipes are assembled into the mold, due to their own weight, the socket surface of the ductile iron jacking pipe and the end face of the spigot end 3 of the pouring mold are respectively pressed against the sealing strips 6, forming a good internal and external sealing effect to prevent the leakage of cement slurry during pouring vibration.

[0024] It should be noted that as a special application of ductile iron pipes, the main production process of ductile iron jacking pipes is to assemble the ductile iron jacking pipe and the pouring mold in advance, and then use a crane and a pipe turning machine to make the ductile iron jacking pipe stand vertically in the pouring pit of the pouring mold. At this time, the socket of the ductile iron jacking pipe is at the bottom, and the bottom support of the pouring mold holds the socket of the ductile iron jacking pipe to ensure sealing. The socket of the ductile iron jacking pipe is at the top, which is convenient for installing the pouring cap. The pouring cap is composed of a receiving hopper and a feeding hopper. During pouring, the concrete falls on the feeding hopper, then flows along the inner wall of the feeding hopper into the receiving hopper, and then into the cavity between the pouring mold and the ductile iron jacking pipe. At the same time of feeding, vibration requirements are accompanied. The purpose is to discharge the air bubbles in the concrete layer and make the whole structure dense to obtain good strength. The pouring mold and the spigot end 3 are designed and manufactured according to the external dimensions of different DN ductile iron jacking pipes and the thickness of the concrete layer. The main dimensions include the inner diameter of the pouring mold, the length of the pouring mold, the outer diameter of the inverted cone of the spigot end 3, etc. The inner diameter of the pouring mold is normally the sum of the outer diameter of the socket of the ductile iron jacking pipe and twice the thickness of the concrete. The length of the pouring mold is the effective length of the ductile iron jacking pipe. The outer diameter of the inverted cone of the spigot end 3 is the lower limit of the standard value of the d3 of the socket of the ductile iron jacking pipe. The main function of the inverted cone is to assist in the concentric positioning of the socket to ensure the concentricity of the ductile iron jacking pipe and the pouring mold during mold assembly.

[0025] The positioning stop block 1 is made of carbon steel and has a triangular structure. A pushing flange is pre-welded at the socket end 2. The positioning stop block 1 is in contact with the outer edge of the pushing flange until they touch. The positioning stop blocks 1 are evenly distributed on the inner wall circumferential surface of the socket end 2. The number of positioning stop blocks 1 is set correspondingly according to the size of the ductile iron jacking pipe. If the size of the ductile iron jacking pipe is DN600 - DN1000, the number of positioning stop blocks 1 is 4 - 10, and 8 is recommended. If the size of the ductile iron jacking pipe is DN1200 - DN2600, the number of positioning stop blocks 1 is 8 - 16, and 12 is recommended.

[0026] Specifically, as Figure 1 shown, triangular positioning stop blocks 1 made of carbon steel are welded around the hopper at the socket end 2 of the casting mold. No installation operation is required during the use of the positioning stop blocks 1. The positioning stop blocks 1 can be fixed by welding, but are not limited to welding. The positioning stop blocks 1 can also be made of other materials and shapes, but need to meet the requirements of good strength and not being easily worn or rusted. The size of the positioning stop blocks 1 is determined by the slope of the hopper, the outer diameter of the pushing flange, and the welding position at the socket end 2. The ultimate requirement is that after assembling the vertical pipes of the mold, the outer edge of the pushing flange and the positioning stop blocks 1 should be in direct contact, so as to accurately position and ensure a good concentric effect.

[0027] The positioning bolts 4 are made of carbon steel. The number of positioning bolts 4 is not less than 4, and the positioning bolts 4 are evenly distributed at a 90° angle in the circumferential direction of the inner edge of the inverted cone at the socket end 3 of the casting mold. The screwing depth of the positioning bolts 4 is 2 mm - 5 mm.

[0028] Specifically, as Figure 2 and Figure 4As shown in the figure, when the casting mold and the ductile iron jacking pipe are assembled, the inverted cone is embedded inside the socket end 3 to play a role in positioning and finding concentricity. However, it is only a rough alignment. Due to the production and processing deviation of 3-10mm in d3 itself for ductile iron jacking pipes of the same caliber, it cannot achieve relatively accurate positioning. Therefore, internal rotating positioning bolts 4 are installed on the circumferential direction of the inner edge of the inverted cone at the socket end 3. During mold assembly, the screwing depth of the positioning bolts 4 is adjusted according to the measured value of the socket d3 size of the ductile iron jacking pipe to ensure the concentricity of the socket of the ductile iron jacking pipe and the socket end 3. The casting mold is normally designed in two halves, and the sizes of the casting mold and the socket end 3 are fixed. Before mold assembly, measure the actual size of the socket d3 of the ductile iron jacking pipe (the socket of the ductile iron jacking pipe is assisted by a sand core to form, and there is almost no ovality). Then, according to this size, adjust the screwing distance corresponding to any positioning bolt 4 at the socket end 3. When installing the socket end 3 during mold assembly, adjust the installation position and make sure to place the adjusted positioning bolt 4 at the top, forming a straight line with the upper part of the entire ductile iron jacking pipe and the casting mold. After the horizontal pipe and mold insertion are completed, then screw the other three positioning bolts 4 to the non-screwable distance to prevent the socket of the ductile iron jacking pipe from deviating again during vertical pipe installation. The positioning bolts 4 can be freely adjusted in screwing size according to different size requirements to ensure the concentricity of the socket end 3. And the movable positioning bolts 4 at the socket end 3 are designed to ensure that the screwing positioning size is flexible and variable, which can adapt to the situation where the d3 values of ductile iron jacking pipes of the same caliber fluctuate differently.

[0029] Two annular grooves 5 are preset at the socket end 3 of the casting mold, and sealing strips 6 are embedded in the annular grooves 5. Among them, the inner annular groove 5 directly needs to be between the socket d1 and d3 of the ductile iron jacking pipe of the corresponding caliber, and the outer annular groove 5 directly needs to be between the socket d1 of the ductile iron jacking pipe of the corresponding caliber and the outer diameter of the socket end 3. The sealing strips 6 are detachably arranged, so that the sealing strips 6 can be detachably replaced. The cross-section of the sealing strips 6 is circular, and the sealing strips 6 are made of alkali-resistant rubber material.

[0030] Specifically, as Figure 3 and Figure 4 shown in the figure, after the pipeline is assembled and the formwork is erected, due to its own weight, the ductile iron jacking pipe is tightly pressed on the inner sealing strip 6, forming an inner sealing effect, which can prevent the overflow of cement slurry during pouring. And the end face of the socket end 3 of the casting mold is tightly pressed on the outer sealing strip 6, and the sealing strip 6 in this area is compressed and deformed under force, forming an outer sealing effect, which can prevent the overflow of cement slurry during pouring. The concrete is poured into the cavity between the inner wall of the casting mold and the outer wall of the pipe through a special pouring cap at the socket, forming an outer concrete protection layer for the ductile iron jacking pipe. Since the sealing strip 6 between the bottom of the socket of the ductile iron jacking pipe and the socket end 3 plays an internal and external sealing role, when the concrete is vibrated and compacted during pouring, there will be no overflow of cement slurry to pollute the inside of the socket of the ductile iron jacking pipe and the casting mold, avoiding the situation of large-area pitting and exposed aggregates on the concrete layer at the socket end 3 due to the lack of cement.

[0031] Working principle: Through the positioning block 1 welded to the socket end 2 of the casting mold, no installation operation is required during use. During mold assembly, the positioning block 1 directly fits with the pushing flange pre-welded on the socket end 2, thereby accurately positioning to ensure the concentricity of the socket end 2. The socket end 3 is designed with a movable positioning bolt 4, and the positioning bolt 4 can freely adjust the screwing-in dimension according to different size requirements to ensure the concentricity of the socket end 3. The design of the movable positioning bolt 4 for positioning the socket end 3 can ensure that the screwing-in positioning dimension is flexible and variable, and can adapt to the situation where the d3 values of ductile iron jacking pipes of the same diameter fluctuate differently. There are two annular grooves 5 opened along the circumferential direction on the inner lower surface of the socket end 3 of the casting mold, and sealing strips 6 are embedded in both of the two annular grooves 5. After the vertical pipes of the mold are assembled, due to their own weight, the socket surface of the ductile iron jacking pipe and the end surface of the socket end 3 of the casting mold are respectively pressed against the sealing strip 6, which can form a good internal and external sealing effect, thereby preventing the leakage of cement slurry during casting vibration.

[0032] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0033] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A concentric and sealed structure for pouring a concrete protective layer of a ductile iron pipe jacking, comprising a spigot end (2) and a socket end (3), wherein the spigot end (2) and the socket end (3) are assembled and connected to the pouring mold by bolts, characterized in that: Positioning blocks (1) are uniformly welded around the inner wall of the socket end (2); an inner-rotating positioning bolt (4) is installed in the circumferential direction of the inner edge of the inverted cone of the socket end (3); the socket end (3) is preset with two annular grooves (5), and sealing strips (6) are embedded in the two annular grooves (5).

2. A concentric and sealed structure for pouring a ductile iron pipe jacking concrete protective layer according to claim 1, characterized in that: The positioning block (1) is made of carbon steel and has a triangular structure.

3. The concentric and sealed structure of a ductile iron pipe jacking concrete protective layer casting mold according to claim 1, characterized in that: The socket end (2) is pre-welded with a push flange, and the positioning stopper (1) is in contact with the outer edge of the push flange.

4. The concentric and sealed structure of a ductile iron pipe jacking concrete protective layer casting mold according to claim 1, characterized in that: The positioning blocks (1) are evenly distributed on the inner wall circumference of the socket end (2), and the number of the positioning blocks (1) is set correspondingly according to the size of the ductile iron jacking pipe.

5. The concentric and sealed structure of a ductile iron pipe jacking concrete protective layer casting mold according to claim 1, characterized in that: The positioning bolts (4) are made of carbon steel, the number of the positioning bolts (4) is not less than 4, and the positioning bolts (4) are evenly distributed at an angle of 90° in the circumferential direction of the inner edge of the inverted cone of the socket end (3) of the casting mold.

6. The concentric and sealing structure of a ductile iron pipe jacking concrete protective layer casting mold according to claim 1, characterized in that: The screw-in depth of the positioning bolt (4) is 2 mm to 5 mm.

7. The concentric and sealing structure of a ductile iron pipe jacking concrete protective layer casting mold according to claim 1, characterized in that: The sealing strip (6) is detachably arranged, and the cross section of the sealing strip (6) is circular.

Images