WO2021249486A1

WO2021249486A1 - Flange-less jacking pipe and casting method therefor

Info

Publication number: WO2021249486A1
Application number: PCT/CN2021/099407
Authority: WO
Inventors: 张同波; 李军; 刘俊锋; 徐军; 田建军; 张俊杰; 宋佳男; 岳江峰; 陈建波; 孟新; 朱盼; 张文军; 未永斌; 李云鹏
Original assignee: 新兴铸管股份有限公司; 新兴河北工程技术有限公司
Priority date: 2020-06-11
Filing date: 2021-06-10
Publication date: 2021-12-16

Abstract

A flange-less jacking pipe comprises a pipe body (4), a bell portion (1), and a spigot portion (2), and further comprises a jacking force bearing member (3). The jacking force bearing member (3) is arranged on an annular surface (11) disposed at the bottom of the bell portion (1) and perpendicular to a pipe axis. The jacking force bearing member (3) fits with a spigot portion (2) of an adjacent jacking pipe to transmit a jacking force between the two adjacent jacking pipes. The flange-less jacking pipe can effectively transmit jacking forces between adjacent jacking pipes by means of the jacking force bearing member (3) arranged on the annular surface disposed at the bottom of the bell portion (1) and perpendicular to the pipe axis. A centrifugal casting method for a flange-less jacking pipe comprises: sleeving a jacking force bearing member (3) on a sand core (8); disposing the sand core (8) sleeved with the jacking force bearing member (3) on a core frame of a centrifugal casting machine; and performing centrifugal casting on a space between the sand core (8) and a pipe mold (9) and a pipe wall of the pipe mold (9). The production process is simple and low cost, and provides a high-strength jacking pipe capable of withstanding large jacking forces.

Description

Flangeless pipe jacking and its casting method

Technical field

The invention relates to a pipe jacking, in particular to a flangeless pipe jacking made by centrifugal casting and a casting method thereof.

Background technique

Ductile iron pipe jacking for trenchless is one of the existing metal pipe jacking technologies. It is a product applied to trenchless jacking construction by improving on the basis of ordinary ductile iron pipes. The outer wall of the cast iron pipe is lined with a certain thickness of cement mortar, and the jacking flange and ribs are welded at the socket part to form a pushing force transmission structure that uses the socket to push the flange to push the end face of the socket, and realize the jacking construction of the pipe . This type of ductile iron pipe jacking product adopts the traditional slide-in interface and rubber ring, which is reliable in sealing and simple and convenient to install. However, the jacking flange and ribs are fixed on the ordinary ductile iron pipe body by welding, and the welding cost is higher. , The welding strength is greater.

Ordinary ductile iron pipes are not suitable for withstanding large pushing force. At the beginning of the design, the convenience of interface installation is considered. The structural design of sockets and sockets is not suitable for pushing operations. Actual tests and engineering installation cases show that ordinary sockets Even if the spheroidal graphite cast iron pipe interface bears a small axial thrust, the socket will be drilled into the straight pipe section of the socket end.

In the application publication number CN106247009A document, a metal tube axial thrust transmission system is proposed. An annular flange is provided at the contact position of the socket and the socket. According to the existing centrifugal casting process, the radial position of the metal tube is changed under the action of centrifugal force. The flange is difficult to produce. The water-cooled centrifugal process is used to set a downward slope in the direction of the socket. Through the centrifugal casting test of small pipe diameter, although the static pressure head of the molten iron can be used to produce a convex structure, its forming rate and product structure The degree of stability is not high, far below the normal production and use standards.

Summary of the invention

The technical problem to be solved by the present invention is to provide a flangeless pipe jacking which has simple production process, low cost and can withstand large pushing force.

The flangeless type jacking pipe of the present invention includes a pipe body, a socket and a socket, and also includes a thrust bearing member. The thrust bearing member is arranged on the ring surface perpendicular to the pipe axis at the bottom of the socket, so The thrust bearing member cooperates with the socket of the adjacent jacking pipe to transmit the pushing force between the two adjacent jacking pipes, and the jacking force member is added to the ring surface at the bottom of the socket during the centrifugal casting process or It is detachably installed on the ring surface of the bottom of the socket formed by centrifugal casting.

The flangeless jacking pipe of the present invention, wherein for the pushing bearing member added to the socket in the centrifugal casting process, the pushing bearing member is pre-installed on the sand core required for centrifugal casting and located on the sand core and At the corresponding part of the annular surface of the bottom of the socket, the thrust bearing member is added to the annular surface of the bottom of the socket by centrifugal casting.

The flangeless jacking pipe of the present invention, wherein for the thrust bearing member detachably installed on the annular surface of the bottom of the socket, a sand core required for centrifugal casting is provided with a ring surface that can form the bottom of the socket The sand mold is formed by centrifugal casting to form the annular surface at the bottom of the socket, and then the thrust bearing member is installed on the annular surface of the socket.

The flangeless pipe jacking of the present invention, wherein the pushing bearing member is an annular body, the inner diameter of the pushing bearing member is equal to or smaller than the inner diameter of the bare metal pipe of the jacking pipe, and the outer diameter of the pushing bearing member The inner diameter of the bare metal pipe larger than the top pipe.

The flangeless type jacking pipe of the present invention, wherein the end surface of the pushing force-bearing member and the socket of the adjacent jacking pipe is provided with an annular groove.

The flangeless jacking pipe of the present invention, wherein an elastic gasket or a deformable metal sheet or a deformable metal sheet and an elastic gasket are arranged between the pushing force member and the socket of the adjacent jacking pipe, and the deformable metal The sheet is located between the socket of the adjacent top pipe and the elastic gasket.

The flangeless jacking pipe of the present invention, wherein the outer peripheral side of the pushing bearing member is in the shape of a column, a cone, an arc, a step, or any combination of a taper, an arc, and a step.

The flangeless jacking pipe of the present invention, wherein the cross section of the pushing bearing member is L-shaped, and the stepped surface of the pushing bearing member abuts on the annular surface of the bottom of the socket and protrudes from the The stepped ring body of the thrust bearing member is inserted into the tube body, and the socket of the adjacent jacking tube abuts on the end surface of the thrust bearing member close to the outer end of the socket.

The flangeless type jacking pipe of the present invention has a buffer pad between the jacking force member and the annular surface at the bottom of the socket.

The flangeless jacking pipe of the present invention, wherein the pushing bearing member is formed by splicing a plurality of bearing unit members arranged in an annular array, and the adjacent bearing unit members are connected by a connecting device.

The invention provides a method for centrifugal casting of the flangeless pipe jacking:

a. Manufacture the sand core corresponding to the socket of the flangeless pipe jacking;

b. At the position of the sand core corresponding to the annular surface at the bottom of the socket, set the thrust bearing member;

c. Install the above-mentioned sand core set with pusher bearing components on the core frame of the centrifugal casting machine;

d. Centrifugal casting the space between the sand core and the pipe mold and the pipe wall of the pipe mold;

e. After centrifugal casting, pull out the flangeless pipe from the pipe mold.

a. Manufacture a sand core corresponding to the socket of the flangeless jacking pipe, and the sand core is provided with a sand mold that can form the annular surface at the bottom of the socket;

b. Install the above-mentioned sand core on the core frame of the centrifugal casting machine;

c. Centrifugal casting the space between the sand core and the pipe mold and the pipe wall of the pipe mold;

d. After centrifugal casting, pull out the flangeless pipe jacking from the pipe mold;

e. Install the thrust bearing member on the ring surface of the socket of the jacking pipe.

Compared with the prior art, the flangeless pipe jack of the present invention has the following beneficial effects:

1. The flangeless pipe jacking of the present invention can effectively transmit the pushing force between adjacent jacking pipes through the pushing bearing member arranged on the ring surface at the bottom of the socket and perpendicular to the pipe axis. The production process is simple and the cost is low. , And the structure is stable, the strength is high, and it can withstand a large pushing force.

2. The flangeless pipe jacking of the present invention adds the thrust bearing member in the centrifugal casting link of the normal production process of the flangeless pipe jack, so that the molten iron and the thrust bearing member can be cast during the centrifugal operation. In the centrifugal pouring process, the production effect of pushing bearing components can be added to the jacking pipe. The process is simple, the forming rate is high, the structure is stable, the additional cost is low, and it can withstand larger pushing forces.

3. The flangeless pipe jacking of the present invention forms a ring surface in the socket that matches the thrust bearing member through the centrifugal casting link in the normal production process of the flangeless pipe jacking. During the subsequent installation of the thrust bearing member , It can make the thrust bearing member be installed in the socket more accurately, and it is not easy to cause deviations, etc., to ensure that the thrust force is transmitted more effectively, and the rear-mounted thrust bearing member is easy to disassemble. By arranging the thrust bearing member as a structure formed by splicing a plurality of bearing unit pieces arranged in an annular array, the installation of the thrust bearing member is more convenient and faster.

4. The flangeless pipe jack of the present invention reduces the inner diameter of the pipe body at the socket by designing the cross section of the thrust bearing member to be L-shaped, which can effectively prevent the sockets of adjacent jacking pipes from escaping into the pipe body, ensuring The coaxiality when the two jacking pipes are connected.

The embodiments of the flangeless pipe jacking of the present invention will be further described below with reference to the accompanying drawings.

Description of the drawings

Fig. 1 is a schematic cross-sectional view of the flangeless jack pipe of the first embodiment and the fourth embodiment of the present invention;

2 is a cross-sectional schematic diagram of the matching relationship between the tube mold and the sand core during the centrifugal casting process of the flangeless pipe jacking of the present invention in the first embodiment;

Figure 3 (a) to (h) are schematic cross-sectional views of the thrust bearing member of the flangeless pipe jack of the present invention in the first embodiment;

4 is a schematic cross-sectional view of the flangeless jack pipe of the second embodiment of the present invention;

Fig. 5 is a schematic cross-sectional view of the flangeless pipe jack of the present invention in the third embodiment;

6 is a schematic cross-sectional view of the matching relationship between the tube mold and the sand core during the centrifugal casting process of the flangeless pipe jacking of the fourth embodiment of the present invention;

Fig. 7 is a schematic cross-sectional view of the flangeless pipe jack of the present invention in the fifth embodiment;

8 is a schematic cross-sectional view of the flangeless pipe jack of the present invention in the sixth embodiment;

Fig. 9 is a schematic cross-sectional view of the flangeless jack pipe of the seventh embodiment of the present invention.

detailed description

In the first embodiment, as shown in FIG. 1, the flangeless jacking pipe of the present invention includes a pipe body 4, a socket 1, a socket 2 and a thrust bearing member 3. The thrust bearing member 3 is arranged on the annular surface 11 perpendicular to the pipe axis at the bottom of the socket 1, and the left end surface of the thrust bearing member 3 is used to cooperate with the end surface of the socket 2 of the adjacent jacking pipe to transmit the two phases. Pushing force between adjacent flangeless jacking pipes. The circumferential inner wall of the socket 1 on the left side of the thrust bearing member 3 may also be provided with a socket guide surface 5, so that the sockets of adjacent top pipes can be inserted into the socket 1 more easily. The inner diameter of the pushing support member 3 is equal to or smaller than the inner diameter of the bare metal pipe of the jacking pipe, and the outer diameter of the pushing support member 3 is greater than the inner diameter of the bare metal pipe of the jacking pipe. The right end surface of the thrust bearing member 3 is in mating contact with the ring surface 11 at the bottom of the socket 2, and the right end surface of the socket 2 of the adjacent jack pipe abuts against the left end surface of the thrust bearing member 3. The thrust bearing member 3 is ferrous metal, such as cast iron, cast steel, forged steel or alloy steel. As shown in Figure 1 and Figure 3(a), the cross section of the thrust bearing member 3 of this embodiment is a simple rectangle, and its processing technology is simple, easy to shape, and low production cost, while being able to withstand greater thrust .

As shown in Figure 3(b)-3(h), the left end surface of the thrust bearing member 3 can also be provided with an annular groove 31 corresponding to the socket 2 on a plane basis. The annular groove 31 is convenient for the installation process The position of the middle socket end prevents the deflection of the jacking pipe due to the effect of non-axial force during the pushing process. In order to further increase the contact area between the thrust bearing member 3 and the inner wall of the socket 1, so that the force of the flangeless pipe jacking is more uniform, as shown in Figure 3(e)-3(h), the thrust bearing member 3 The outer diameter can gradually decrease from one end close to the socket to the other end far away from the socket. The outer peripheral surface 32 of the thrust bearing member 3 can be cylindrical, tapered, arc, stepped or cylindrical, Any combination of conical, arc, and stepped shapes. As shown in Fig. 3(d), the thrust bearing member 3 can also be provided with a boss extending in the axial direction of the pipe body 4, which can further prevent the socket 2 from escaping into the pipe body 4.

As shown in Fig. 2, the thrust bearing member 3 is integrated with the socket 1 by centrifugal casting or inlaid together or a combination of fusion casting and inlaid. Before centrifugal casting the flangeless pipe jacking of the present invention, first pre-install the thrust bearing member 3 on the sand core 8 required for centrifugal casting, and ensure that the thrust bearing member 3 is located on the sand core 8 and at the bottom of the socket 1. In the centrifugal casting process, the temperature of the injected molten iron determines the final state between the thrust bearing member 3 and the socket 1. For example, the temperature of the molten iron is higher than the top The melting point of the thrust member 3 can be integrated into the thrust member 3 and the socket 1. If the temperature of the molten iron is lower than the melting point of the thrust member 3, between the thrust member 3 and the socket 1 For the existence of the inlay form, if the molten iron problem lies within the upper and lower ranges of the melting point of the thrust bearing member 3, the thrust bearing member 3 and the socket 1 are a combination of inlay and fusion casting. In the normal production process of the pipe jacking, through the melting of molten iron and the jacking support member 3 in the centrifugal casting operation, the jacking member 3 is added to the jacking pipe. The process is simple, the forming rate is high, and the structure is Stable and low additional cost; at the same time, the thrust bearing member 3 itself is a rigid component, which can effectively transmit the axial force of the thrust process to the tube body 4 as a whole. During the pushing process, if the pushing force is too large, the pushing bearing member will break, which will cause the stress to redistribute and reduce the impact on the pipe itself.

As shown in Figure 2, the centrifugal casting method for flangeless pipe jacking of the present invention is:

(1) Manufacture the sand core 8 corresponding to the socket 1 of the jacking pipe;

(2) Put the thrust bearing member 3 on the above-mentioned sand core 8, and ensure that the thrust bearing member 3 is located on the sand core 8 corresponding to the bottom ring surface 11 of the socket 1;

(3) Install the above-mentioned sand core 8 with the pusher bearing 3 on the core frame of the centrifugal casting machine;

(4) Centrifugal pouring the space between the sand core 8 and the tube mold 9 and the tube wall of the tube mold 9;

(5) After centrifugal casting, pull out the top tube from the tube mold 9.

The flangeless pipe jack of the present invention adds a thrust bearing member to the socket during the centrifugal casting process, and its production process is simple, the forming rate is high, the structure is stable and the production cost is low; the thrust bearing member is a rigid part and is located in the bearing The bottom of the mouth is perpendicular to the ring surface of the pipe axis, which can effectively transmit the pushing force between adjacent jacking pipes and effectively prevent the sockets of adjacent jacking pipes from drilling into the straight pipe at the socket end. The flangeless pipe jacking of the present invention effectively improves the production efficiency of the enterprise, reduces the production cost, and also greatly improves the work efficiency during the jacking operation. During on-site operation, only the sockets of the adjacent jacking pipes need to be inserted into the sockets And make sure that the end face of the socket abuts on the thrust bearing member.

The second embodiment, as shown in Fig. 4, the flangeless jacking pipe of the present invention is different from the first embodiment in that an elastic gasket 61 is installed between the jacking force member 3 and the socket 2 of the adjacent jacking pipe. . The elastic gasket 61 may be a material with certain elasticity, such as a wooden gasket or a fiber gasket.

The flangeless pipe jack of the present invention adds an elastic gasket 61 on the basis of the first embodiment, which can also prevent the occurrence of stress concentration during the jacking operation, and effectively buffer the jacking force of the socket of the adjacent jacking pipe against the jacking force. The impact force of the part 3 ensures the effective transmission of the pushing force during the pushing operation and increases the service life of the pushing force-bearing parts.

The third embodiment, as shown in FIG. 5, the difference between the flangeless jack pipe of the present invention and the second embodiment is that a variable metal sheet 62 is installed between the socket 2 of the adjacent jack pipe and the elastic gasket 61. The variable metal sheet 62 is an annular sheet and is made of easily deformable metal material. When the socket 2 of the adjacent jacking pipe transmits the pushing force to the flexible metal sheet 62, the elastic gasket 61 located on the right side of the flexible metal sheet 62 is elastically deformed under the force, and the flexible metal 62 is elastic on the elastic gasket 61 When deformed, it also deforms under the pushing force and wraps the spigot end of the adjacent jacking pipe, which can effectively protect and position the spigot end of the adjacent jacking pipe, ensuring that the pushing force between adjacent jacking pipes is more stable and effective Of delivery.

In the fourth embodiment, the flangeless pipe jacking of the present invention is different from the first embodiment in that the method for adding the thrust bearing member 3 is different from that in the first embodiment, and the jacking member 3 is detachably installed on the jacking pipe The bottom ring surface of the socket 1 is at 11 points.

As shown in Figure 6, the centrifugal casting method of the flangeless pipe jacking of the present invention is:

(1) Manufacture the sand core 8 corresponding to the socket 1 of the jacking pipe, and the sand core 8 is provided with a sand mold 81 that can form the ring surface 11 at the bottom of the socket 1;

(2) Install the above-mentioned sand core 8 on the core frame of the centrifugal casting machine;

(3) Centrifugal pouring the space between the sand core 8 and the tube mold 9 and the tube wall of the tube mold 9;

(4) After centrifugal casting, pull out the top tube from the tube mold 9;

(5) Install the detachable thrust bearing member 3 on the ring surface 11 of the socket 1 of the jacking pipe.

The thrust bearing member of the flangeless pipe jacking of the invention can be detachably installed at the socket, which is beneficial to the later maintenance and replacement of the thrust bearing member.

The fifth embodiment, as shown in FIG. 7, the difference between the flangeless jacking pipe of the present invention and the fourth embodiment is that the detachable thrust bearing member 3 is composed of a plurality of bearing unit members 34 arranged in a circular array. It is formed by splicing, the load-bearing unit member 34 is an arc-shaped part, and the adjacent load-bearing unit members 34 are connected by a connecting device 35. The connecting device 35 includes a connecting plate that connects two adjacent load-bearing unit members 34 together. One end of the connecting plate is fixed to the inner wall of one of the load-bearing unit members 34 by bolts, and the other end of the connecting plate is fixed to the inner wall of the other adjacent load-bearing unit member by bolts. When installing the thrust bearing components, it is only necessary to put the bearing unit components into the ring surface of the bottom surface of the socket one by one, and connect them through the connecting device, which greatly saves the labor intensity during installation.

The detachable thrust bearing member 3 of the flangeless pipe jacking of the present invention is formed by splicing a plurality of bearing unit parts 34, and its installation is simple and easy to operate, which greatly reduces the difficulty and labor intensity of the installation of the thrust bearing member 3 .

The sixth embodiment, as shown in Figure 8, the flangeless pipe jacking of the present invention is different from the fifth embodiment in that: the cross-street surface of the detachable pushing bearing member 3 is L-shaped, and the pushing bearing member 3 is L-shaped. The annular body of 3 protruding to the right with a stepped surface at the right end is inserted into the tube body 4 and fits with the inner wall of the tube body 4. A cushion 7 is provided between the stepped surface of the right end of the thrust bearing member 3 and the annular surface 11 at the bottom of the socket 1. The cushion 7 provides a buffering effect to prevent the stepped surface of the right end of the thrust bearing member 3 from directly acting on the socket 1. The annular surface 11 at the bottom of the socket 1 can effectively protect the annular surface 11 at the bottom of the socket 1 from being damaged and increase the service life of the jacking pipe. The inner wall of each force-bearing unit member 34 is also provided with a dismounting threaded hole 36 for disassembling the pushing force-bearing member. When it is necessary to disassemble the thrust bearing member 3 installed on the socket 1, screw the bolt 37 into the disassembly threaded hole 36 so that the end of the bolt 37 abuts the inner wall of the pipe body 4, and continue to rotate the bolt 37. Remove the load-bearing unit 34.

The L-shaped cross section of the detachable thrust bearing member of the flangeless pipe jack of the present invention reduces the inner diameter of the pipe body 4 at the socket 1, which can effectively prevent the sockets of adjacent jacking pipes from escaping into the pipe body 4. To ensure the coaxiality when the two jacking pipes are connected; a cushion 7 is provided between the thrust bearing member 3 and the annular surface 11 at the bottom of the socket 1, which can effectively protect the quality of the inner lining of the socket 1 and improve the top pipe The service life; at the same time, by setting the disassembly threaded hole on the thrust bearing member, the disassembly of the thrust bearing member is more convenient and fast.

The seventh embodiment, as shown in FIG. 9, the difference between the flangeless jacking pipe of the present invention and the sixth embodiment is that: a jack is provided between the detachable jacking force member 3 and the socket of the adjacent jacking pipe Bearing shoe 63, the left end surface of the thrust bearing shoe is provided with an annular groove that matches the socket of the adjacent top pipe, which facilitates the placement of the socket end of the adjacent top pipe during the installation process. Effective positioning of the end to ensure a more stable and effective transmission of the pushing force between adjacent jacking pipes, and to prevent the deflection of the jacking pipe due to the effect of non-axial force during the pushing process.

The thrust bearing shoe 63 can be formed by splicing a plurality of bearing shoe unit parts, and the adjacent bearing shoe unit parts are fixed by connecting plates and bolts, and the installation is simple and the labor intensity is low.

The thrust bearing shoe 63 in this embodiment can also be replaced with the elastic gasket 61 and the variable metal sheet 62 in the third embodiment, which can also realize the technology of effectively protecting and positioning the socket end of the adjacent jacking pipe Effect.

The above embodiments are only a description of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and changes made by those of ordinary skill in the art to the technical solutions of the present invention All improvements should fall within the protection scope determined by the claims of the present invention.

Industrial applicability

The flangeless jacking pipe of the present invention can effectively transmit the pushing force between adjacent jacking pipes through the pushing bearing member arranged on the annular surface at the bottom of the socket and perpendicular to the pipe axis. The production process is simple, and the cost is low. The structure is stable, the strength is high, and it can withstand a large pushing force.

Claims

A flangeless type jacking pipe, comprising a pipe body (4), a socket (1) and a socket (2), and is characterized in that it further comprises a pushing bearing member (3), the pushing bearing member (3) ) Is arranged on the annular surface (11) at the bottom of the socket (1) that is perpendicular to the pipe axis, and the push bearing member (3) cooperates with the socket (2) of the adjacent jack to transmit two phases The pushing force between adjacent jacking pipes, the pushing bearing member (3) is added to the annular surface (11) at the bottom of the socket (1) during the centrifugal casting process or is detachably installed on the ring surface (11) formed by centrifugal casting On the annular surface (11) at the bottom of the socket (1).
The flangeless jacking pipe according to claim 1, characterized in that: for the pushing bearing member (3) added to the socket (1) during the centrifugal casting process, the pushing bearing member (3) ) Is pre-installed on the sand core (8) required for centrifugal casting and located at the corresponding position of the sand core (8) and the annular surface (11) at the bottom of the socket (1). Through centrifugal casting, the force-bearing member ( 3) It is added to the annular surface (11) at the bottom of the socket (1).
The flangeless jacking pipe according to claim 1, characterized in that: for the thrust bearing member (3) detachably installed on the annular surface (11) at the bottom of the socket (1), the The sand core (8) required for casting is provided with a sand mold that can form the ring surface (11) at the bottom of the socket (1). The ring surface (11) at the bottom of the socket (1) is formed by centrifugal casting, and then the top is pushed The bearing member (3) is installed on the annular surface (11) of the socket (1).
The flangeless pipe jacking according to claim 2 or 3, characterized in that: the pushing bearing member (3) is an annular body, and the inner diameter of the pushing bearing member (3) is equal to or smaller than that of the jacking pipe The inner diameter of the bare metal pipe is larger than the inner diameter of the bare metal pipe of the jacking member (3).
The flangeless jack pipe according to claim 4, characterized in that: the end surface of the pushing force-bearing member (3) which is matched with the socket (2) of the adjacent jacking pipe is provided with an annular groove (31).
The flangeless jack pipe according to claim 4, characterized in that: an elastic gasket (61) or easily deformable is provided between the pushing force-bearing member (3) and the socket (2) of the adjacent jacking pipe The metal sheet (62) or the variable metal sheet (62) and the elastic gasket (61), the variable metal sheet (62) is located between the socket (2) of the adjacent top pipe and the elastic gasket (61).
The flangeless jacking pipe according to claim 4, characterized in that: the circumferential outer side surface (32) of the thrust bearing member (3) is cylindrical, tapered, arc-shaped, stepped or tapered Any combination of, arc and ladder shapes.
The flangeless type jacking pipe according to claim 3, characterized in that: the cross section of the thrust bearing member (3) is L-shaped, and the stepped surface of the thrust bearing member (3) abuts on the On the annular surface (11) at the bottom of the socket (1), the annular body protruding from the stepped surface of the thrust bearing member (3) is inserted into the tube body (4), adjacent to the socket of the top tube (2) Abutting on the end surface of the pushing bearing member (3) close to the outer end of the socket (1).
The flangeless jack pipe according to claim 8, characterized in that: a cushion (7) is provided between the thrust bearing member (3) and the annular surface (11) at the bottom of the socket (1).
The flangeless jacking pipe according to any one of claims 3 or 8-9, characterized in that: the thrust bearing member (3) consists of a plurality of bearing unit members (34) arranged in a circular array It is formed by splicing, and the adjacent load-bearing unit pieces (34) are connected by a connecting device (35).
A method for centrifugal casting of flangeless pipe jacking according to claim 2, characterized in that:

a. Manufacture the sand core (8) corresponding to the socket (1) of the flangeless pipe jacking;

b. At the position corresponding to the annular surface (11) at the bottom of the socket (1) of the above-mentioned sand core (8), set the thrust bearing member (3);

c. Install the above-mentioned sand core (8) with the pusher bearing (3) on the core frame of the centrifugal casting machine;

d. Centrifugal casting the space between the sand core (8) and the tube mold (9) and the tube wall of the tube mold (9);

e. After centrifugal casting, pull out the flangeless top tube from the tube mold (9).
A method for centrifugal casting of flangeless pipe jacking according to claim 3, characterized in that:

a. Manufacture a sand core (8) corresponding to the socket (1) of the flangeless jacking pipe, and the sand core (8) is provided with a sand mold that can form the ring surface (11) at the bottom of the socket (1) (81);

b. Install the above-mentioned sand core (8) on the core frame of the centrifugal casting machine;

c. Centrifugal casting the space between the sand core (8) and the tube mold (9) and the tube wall of the tube mold (9);

d. After centrifugal casting, pull out the flangeless pipe jacking from the pipe mold (9);

e. Install the thrust bearing member (3) on the ring surface (11) of the socket (1) of the jacking pipe.