Pulling-out tool and method for ceramic lining pipe with round hole without step and smooth inner wall

Abstract

The invention discloses a pulling tool and method for a ceramic lining pipe with a round hole and a step-free smooth inner wall, and belongs to the technical field of mechanical tools. Comprising a round hole piece base body, a positioning barrel, a lock cone and a spring cotter. A plurality of lining pipe bolt holes are formed in the wall surface of the ceramic lining pipe in the circumferential direction; the positioning cylinder is of a hollow circular ring structure, and the outer diameter of the positioning cylinder is matched with the inner diameter of the lining pipe. A plurality of positioning cylinder bolt holes are formed in the wall surface of one end of the positioning cylinder relative to the lining pipe bolt holes; an inner bulge is arranged on the inner wall surface of the positioning cylinder, and an outer bulge is arranged on the outer wall surface of the positioning cylinder; the lock cone is of a stepped cylindrical structure and sequentially comprises a small-end cylindrical section, a slope section, a middle cylindrical section and a large-end cylindrical section from the end, extending into the positioning barrel, of the lock cone. The tool is used for applying uniform torsion / tensile load to the liner tube with the step-free smooth inner wall of the round hole, so that the liner tube in the round hole is smoothly taken out, the liner tube can be effectively, conveniently and quickly taken out, the working efficiency is improved, and the labor and accessory cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical tools, and relates to a tool and a method for extracting a ceramic lined pipe with a round hole and a smooth inner wall without steps. Background Art

[0002] Due to the need for a non-magnetic environment for mechanical components, it is often necessary to place a liner made of special materials on the inner wall of the circular hole of a metal pipe fitting, such as a non-metallic ceramic liner used in a rotary steerable instrument for drilling, so that the local area is in a non-magnetic environment. The liner and the circular hole fitting are clearance-matched during assembly. During use, due to corrosion of the inner wall of the circular hole fitting or other impurities entering the annulus between the liner and the circular hole fitting, the liner and the inner wall of the circular hole fitting are often tightly adhered together. When removing the liner, it is difficult to remove the liner efficiently because the inner wall of the liner is smooth and there is no grip available. The traditional way to disassemble the ceramic liner of the rotary steerable instrument is to break it and then remove it, which consumes labor costs and wastes the cost of accessories. The traditional method of pulling the liner in the petroleum industry usually uses the slip teeth to expand and bite the inner wall of the liner before pulling, which will leave slip bite marks on the inner wall of the liner, causing certain damage to the liner, and the slip teeth are difficult to bite on the high-hardness ceramic liner. Therefore, there is an urgent need for an extraction device suitable for a ceramic lined tube with a smooth inner wall and round holes in a rotary guide instrument. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problems in the prior art of low efficiency and damage to the liner tube when extracting the liner tube, and to provide a tool and method for extracting a ceramic liner tube with a round hole, smooth inner wall and no steps.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In the first aspect, the present invention provides a tool for extracting a ceramic lined tube with a round hole having a smooth inner wall without steps, comprising a round hole base, a positioning cylinder, a locking cone and a spring latch; a ceramic lined tube is installed in the round hole base, and a plurality of lined tube latch holes are circumferentially arranged on the wall surface of the ceramic lined tube; the positioning cylinder is a hollow circular ring structure, and its outer diameter matches the inner diameter of the lined tube; a plurality of positioning tube latch holes are arranged on the wall surface of one end of the positioning cylinder relative to the lined tube latch holes; an inner protrusion is arranged on the inner wall surface of the positioning cylinder, and an outer protrusion is arranged on the outer wall surface; the locking cone is a stepped cylindrical structure, which is arranged in sequence from the end extending into the positioning cylinder, namely, a small end cylindrical section, a ramp section, an intermediate cylindrical section and a large end cylindrical section; the outer protrusion contacts the end surface of the lined tube to limit the length of the positioning cylinder extending into the lined tube; the inner protrusion contacts the step surface of the large end cylindrical section to limit the length of the locking cone extending into the positioning cylinder;

[0006] During assembly, the spring latch is installed into the latch hole of the positioning tube, and one end of the positioning tube is inserted into the inner liner tube. As the locking cone is inserted into the positioning tube, the end face of the spring latch first contacts the outer wall surface of the small end cylindrical section, and then reaches the middle cylindrical section along the slope section. The spring latch is inserted into the latch hole of the inner liner tube, and the assembly is completed; the positioning tube is rotated to expose one end of the inner liner tube, driving the spring latch and the inner liner tube to rotate, and the inner liner tube is pulled out.

[0007] The present invention is further improved in that:

[0008] An outer sleeve is provided on the outside of the positioning cylinder, and one end face of the outer sleeve cooperates with the end face of the circular hole component base to limit the length of the circular hole component base extending into the outer sleeve; the inner diameter of the outer sleeve is larger than the outer diameter of the inner liner tube, and the depth is larger than the sum of the lengths of the inner liner tube and the positioning cylinder after assembly; an internal thread is provided on the inner wall surface of one end of the positioning cylinder where the positioning cylinder pin hole is not provided, and the positioning cylinder is connected to a screw rod via the internal thread, and the end of the screw rod extending out of the outer sleeve is connected to a back cap.

[0009] One end of the spring pin is inserted into the pin hole of the positioning tube and is connected to a stop ring. The outer diameter of the stop ring is larger than the inner diameter of the pin hole of the positioning tube and smaller than the inner diameter of the pin hole of the liner tube, and is used to prevent the spring pin from withdrawing from the pin hole of the positioning tube.

[0010] The inner liner tube has two pin holes which are symmetrical with respect to the axis of the positioning tube.

[0011] The inclination angle of the slope section is 20°-30°.

[0012] One end of the spring latch in contact with the slope section is also provided with a slope, and the inclination angle of the write slope is the same as the inclination angle of the slope section.

[0013] The screw rod is a screw rod with a strength grade of 12.9.

[0014] The main body material of the positioning tube and the spring latch is 17-4 stainless steel.

[0015] The cross section of the outer wall of the end of the positioning tube that is not inserted into the liner tube is polygonal.

[0016] In a second aspect, the present invention provides a method for extracting a ceramic lined pipe with a round hole having a smooth inner wall without steps using the above-mentioned extraction tool, comprising the following steps:

[0017] Step 1: Install the spring latch into the latch hole of the positioning tube and install the stop ring; install the positioning tube into the inner liner tube and adjust the position so that the latch hole of the inner liner tube and the latch hole of the positioning tube are aligned; then push the locking cone into the inner hole of the positioning tube so that the spring latch passes through the latch hole of the inner liner tube;

[0018] Step 2: Rotate the positioning tube to expose one end of the liner tube, drive the spring latch and the liner tube to rotate, loosen the liner tube to eliminate the adhesion state, and pull out the liner tube;

[0019] Step three, after completing step one, do not pull out the inner liner tube by rotating the positioning tube, install the screw into the end of the positioning tube with the internal thread, then install the outer sleeve, connect the part of the screw exposed from the outer sleeve to the hollow hydraulic jack, and then install the back cap to the end of the screw extending out of the hollow hydraulic jack. Apply thrust to the back cap through the hollow hydraulic jack to drive the screw, and the screw drives the positioning tube, spring pin and inner liner tube to pull out the inner liner tube.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The invention discloses a tool for extracting a ceramic liner tube with a smooth inner wall of a circular hole without steps. During assembly, a spring latch is installed in the latch hole of a positioning tube, and one end of the positioning tube is inserted into the liner tube. As the locking cone is inserted into the positioning tube, the end face of the spring latch first contacts the outer wall of the small-end cylindrical section, and then, after reaching the middle cylindrical section along the slope section, the spring latch is inserted into the latch hole of the liner tube, and assembly is completed; the positioning tube is rotated to expose one end of the liner tube, driving the spring latch and the liner tube to rotate, and the liner tube is extracted. The tool applies a uniform torsional / tensile load to the liner tube with a smooth inner wall of the circular hole without steps, so that the adhesion state of the liner tube to the inner wall of the circular hole caused by corrosion, static friction and the like is loosened, thereby smoothly removing the liner tube in the circular hole, avoiding the problems of being unable to be extracted manually, being time-consuming and labor-intensive to manually break and remove the liner tube, and wasting the cost of accessories. The tool has the characteristics of high reliability and convenient operation, can effectively realize convenient and quick removal of the liner tube, improve work efficiency, and reduce labor and accessory costs.

[0022] Furthermore, if the liner tube cannot be pulled out by manually rotating the positioning tube, a screw rod can be installed on the positioning tube, and an outer sleeve can be installed outside the positioning tube, and a hollow hydraulic jack can be connected through the screw rod. A back cap is installed on the exposed end of the screw rod. The hollow hydraulic jack applies thrust to the back cap, and the thrust is sequentially transmitted from the back cap to the screw rod, the positioning tube, the spring latch and the liner tube, so that the liner tube is pulled out from the base of the round hole member. Improve work efficiency.

[0023] Furthermore, the inclination angle of the slope section on the locking cone is 20°-30°, which can avoid the thrust required to push the locking cone due to a large angle, and avoid the travel required to push the locking cone due to a small angle. The spring latch and the inclined surface of the locking cone have the same inclination angle, which prevents the spring latch from tilting when being pushed radially by the locking cone.

[0024] Furthermore, the screw rod has a strength grade of 12.9, and the main body material of the spring pin and the positioning tube is 17-4 stainless steel, which ensures that the bearing capacity of the parts is greater than the adhesion between the liner pipe and the round hole part. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is an assembly diagram of an extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps in the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the extraction tool of the ceramic lined pipe with a round hole and a smooth inner wall without steps after the extraction is completed in the present invention;

[0028] Figure 3 It is a front view of a positioning cylinder in an extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps in the present invention;

[0029] Figure 4 It is a cross-sectional view of a positioning cylinder in an extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps in the present invention;

[0030] Figure 5 It is a schematic diagram of the structure of a spring latch in an extraction tool for a ceramic lined pipe with a round hole having a smooth inner wall without steps in the present invention;

[0031] Figure 6 It is a schematic structural diagram of a locking cone in an extraction tool for a ceramic lined pipe with a round hole having a smooth inner wall without steps in the present invention;

[0032] Figure 7 It is a schematic diagram of the structure of the screw rod in the extraction tool of the ceramic lined pipe with round hole and smooth inner wall without steps in the present invention;

[0033] Figure 8 It is a structural schematic diagram of the outer sleeve of the extraction tool for the ceramic lined pipe with a round hole and a smooth inner wall without steps in the present invention;

[0034] Fig. 9 It is a schematic structural diagram of the back cap in the extraction tool of the ceramic lined pipe with round hole and smooth inner wall without steps in the present invention.

[0035] Among them: 1-positioning cylinder; 2-spring latch; 3-locking cone; 4-screw rod; 5-outer sleeve; 6-hollow hydraulic jack; 7-back cap; 8-inner liner; 9-circular hole base; 101-latch hole; 102-hexagonal section; 201-spring; 202-retaining ring; 301-slope section; 302-small end cylindrical section; 303-middle cylindrical section; 304-large end cylindrical section. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0040] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0043] See also Figure 1 and Figure 2 The embodiment of the present invention discloses a tool for extracting a ceramic lined pipe with a round hole having a smooth inner wall without steps, comprising a round hole base 9, a positioning tube 1, a locking cone 3 and a spring latch 2; a ceramic lined pipe 8 is installed in the round hole base 9, and two symmetrical inner lined pipe latch holes are arranged on the wall surface of the ceramic lined pipe 8 in the circumferential direction relative to the axis of the positioning tube 1; Figure 3 and Figure 4 The positioning tube 1 is a hollow ring structure, and its outer diameter matches the inner diameter of the inner liner tube 8. The outer wall cross section of the end of the positioning tube 1 that is not inserted into the inner liner tube 8 is a hexagonal structure. Two positioning tube pin holes 101 are provided on the wall surface of one end of the positioning tube 1 relative to the inner liner tube pin hole; the inner wall surface of the positioning tube 1 is provided with an inner protrusion, and the outer wall surface is provided with an outer protrusion; Figure 6 As shown, the locking cone 3 is a stepped cylindrical structure, which is composed of a small end cylindrical section 302, a ramp section 301, an intermediate cylindrical section 302 and a large end cylindrical section 304 from one end extending into the positioning cylinder 1; the inclination angle of the ramp section 301 is 20°-30°. This can avoid the thrust required to push the locking cone due to a large angle, and avoid the travel required to push the locking cone due to a small angle. The inclination angles of the spring latch and the inclined surface of the locking cone are consistent, which prevents the spring latch from tilting when being pushed radially by the locking cone.

[0044] See also Figure 5 The end of the spring latch 2 that contacts the slope section 301 is also provided with a slope, and the inclination angle of the writing slope is the same as the inclination angle of the slope section 301. The outer protrusion contacts the end surface of the inner liner 8 to limit the length of the positioning tube extending into the inner liner 8; the inner protrusion contacts the step surface of the large end cylindrical section 304 to limit the length of the locking cone 3 extending into the positioning tube 1; Figure 8 As shown, an outer sleeve 5 is provided on the outside of the positioning cylinder 1, and one end face of the outer sleeve 5 cooperates with the end face of the circular hole member base 9 to limit the length of the circular hole member base 9 extending into the outer sleeve 5; the inner diameter of the outer sleeve 5 is larger than the outer diameter of the inner liner 8, and the depth is larger than the sum of the lengths of the inner liner 8 and the positioning cylinder 1 after assembly; an internal thread is provided on the inner wall surface of the end of the positioning cylinder 1 that is not provided with the positioning cylinder pin hole 101, and the positioning cylinder 1 is connected to a screw rod 4 through the internal thread, as shown in FIG. Fig. 9 As shown, one end of the screw rod 4 extending out of the outer sleeve 5 is connected to a back cap 7. Figure 7 As shown, the screw rod 4 is a screw rod with a strength grade of 12.9, and the main body material of the positioning cylinder 1 and the spring latch 2 is 17-4 stainless steel. It is ensured that the bearing capacity of the parts is greater than the adhesion between the liner pipe and the round hole part.

[0045] During assembly, the spring latch 2 is installed into the positioning tube latch hole 101, and one end of the spring latch 2 is inserted into the positioning tube latch hole 101 and is connected to a stop ring 202. The outer diameter of the stop ring 202 is larger than the inner diameter of the positioning tube latch hole 101 and smaller than the inner diameter of the inner liner tube latch hole, which is used to prevent the spring latch 2 from withdrawing from the positioning tube latch hole 101. One end of the positioning tube 1 is inserted into the inner liner tube 8, and as the locking cone 3 is inserted into the positioning tube 1, the end face of the spring latch 2 first contacts the outer wall surface of the small end cylindrical section 302, and then reaches the middle cylindrical section 302 along the ramp section 301. The spring latch 2 is inserted into the inner liner tube latch hole, and the assembly is completed; the positioning tube 1 is rotated to expose one end of the inner liner tube 8, driving the spring latch 2 and the inner liner tube 8 to rotate, and the inner liner tube 8 is pulled out.

[0046] The embodiment of the present invention also discloses a method for extracting a ceramic lined pipe with a round hole and a smooth inner wall without steps, comprising the following steps:

[0047] Step 1: Install the spring latch 2 into the latch hole 101 of the positioning tube, and install the stop ring 202; install the positioning tube 1 into the inner liner tube 8, and adjust the position so that the inner liner tube latch hole and the positioning tube latch hole 101 are aligned; then push the locking cone 3 into the inner hole of the positioning tube 1, so that the spring latch 2 passes through the inner liner tube latch hole;

[0048] Step 2: Rotate the positioning cylinder 1 to expose one end of the liner tube 8, drive the spring latch 2 and the liner tube 8 to rotate, so that the liner tube 8 is loosened and the adhesion state is eliminated, and the liner tube 8 is pulled out;

[0049] Step three, after completing step one, without pulling out the inner lining tube 8 by rotating the positioning tube 1, install the screw rod 4 into the end of the positioning tube 1 provided with the internal thread, then install the outer sleeve 5, connect the part of the screw rod 4 exposed from the outer sleeve 5 to the hollow hydraulic jack 6, and then install the back cap 7 to the end of the screw rod 4 extending out of the hollow hydraulic jack 6, and apply thrust to the back cap 7 through the hollow hydraulic jack 6 to drive the screw rod 4, and the screw rod 4 drives the positioning tube 1, the spring pin 2 and the inner lining tube 8 to pull out the inner lining tube 8.

[0050] The working process of the present invention is as follows:

[0051] Rotary extraction:

[0052] Assembly: The spring latch 2 is placed in the latch hole 101 of the positioning tube, and the locking cone 3 is pushed into the inner hole of the positioning tube 1, so that the spring latch 2 passes through the pin hole of the positioning tube 1. The positioning tube 1 is placed in the inner liner 8, and the locking cone 3 is continuously pushed so that the spring latch 2 passes through the round hole of the inner liner 8. Use: Rotate the exposed hexagonal structure of the positioning tube 1 to drive the spring latch 2 and the inner liner 8 to rotate, so that the inner liner 8 is loosened and the adhesion state is eliminated, and the inner liner 8 can be taken out.

[0053] Screw extraction:

[0054] Assembly: The spring latch 2 is placed in the latch hole 101 of the positioning tube, the locking cone 3 is pushed into the inner hole of the positioning tube 1, and the spring latch 2 is pushed through the pin hole of the positioning tube 1. The screw 4 is screwed into the inner thread of the positioning tube 1 to prevent the locking cone 3 from withdrawing. The positioning tube 1 is placed in the inner liner tube 8, and the screw 4 is screwed in continuously until the spring latch passes through the inner liner tube 8. The outer sleeve 5 is sleeved on the outside of the screw 4, and the left end face is positioned with the end face of the circular hole member base 9. The hollow hydraulic jack 6 is sleeved on the outside of the screw 4, and the left end face is positioned with the end face of the outer sleeve 5. The back cap 7 is screwed into the screw 4, and the left end face is positioned with the hollow hydraulic jack 6. Use: Start the hollow hydraulic jack 6 and extend the hydraulic rod, so that the back cap 7 moves to the right, and the back cap 7 drives the screw 4, the positioning tube 1, the spring latch 2, and the inner liner tube 8 to move to the right, and the inner liner tube 8 is taken out.

[0055] The present invention discloses a tool and method for extracting a ceramic lined pipe with a round hole and a smooth inner wall without steps. The tool and method are pulled by a hollow hydraulic jack, which solves the problems of low extraction efficiency, waste of accessories and high cost caused by the crushing method for extracting the ceramic lined pipe, reduces the labor intensity of personnel operation, saves 97% of the disassembly time, has the characteristics of high reliability and easy operation, and can remove the lined pipe conveniently, quickly and non-destructively.

[0056] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tool for extracting a ceramic lined pipe with a round hole and a smooth inner wall without steps, characterized in that: The invention comprises a circular hole component base (9), a positioning tube (1), a locking cone (3) and a spring latch (2); a ceramic inner liner tube (8) is installed in the circular hole component base (9), and a plurality of inner liner tube latch holes are arranged on the circumferential surface of the wall of the ceramic inner liner tube (8); the positioning tube (1) is a hollow circular ring structure, and its outer diameter matches the inner diameter of the inner liner tube (8); a plurality of positioning tube latch holes (101) are arranged on the wall surface of one end of the positioning tube (1) relative to the inner liner tube latch hole; the inner wall surface of the positioning tube (1) is provided with a plurality of positioning tube latch holes (101); There is an inner protrusion, and the outer wall surface is provided with an outer protrusion; the locking cone (3) is a stepped cylindrical structure, and from the end extending into the positioning tube (1), there are a small end cylindrical section (302), a slope section (301), an intermediate cylindrical section (302) and a large end cylindrical section (304) in sequence; the outer protrusion contacts the end surface of the inner liner tube (8) to limit the length of the positioning tube extending into the inner liner tube (8); the inner protrusion contacts the step surface of the large end cylindrical section (304) to limit the length of the locking cone (3) extending into the positioning tube (1); During assembly, the spring latch (2) is inserted into the latch hole (101) of the positioning tube, and one end of the positioning tube (1) is inserted into the inner lining tube (8). As the locking cone (3) is inserted into the positioning tube (1), the end face of the spring latch (2) first contacts the outer wall of the small end cylindrical section (302), and then reaches the middle cylindrical section (302) along the slope section (301). The spring latch (2) is inserted into the latch hole of the inner lining tube, and the assembly is completed; the positioning tube (1) is rotated to expose one end of the inner lining tube (8), driving the spring latch (2) and the inner lining tube (8) to rotate, and the inner lining tube (8) is pulled out.

2. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: An outer sleeve (5) is arranged on the outside of the positioning sleeve (1), and one end face of the outer sleeve (5) cooperates with the end face of the circular hole component base (9) to limit the length of the circular hole component base (9) extending into the outer sleeve (5); the inner diameter of the outer sleeve (5) is greater than the outer diameter of the inner liner (8), and the depth is greater than the sum of the lengths of the inner liner (8) and the positioning sleeve (1) after assembly; an internal thread is arranged on the inner wall surface of one end of the positioning sleeve (1) where the positioning sleeve pin hole (101) is not arranged, and the positioning sleeve (1) is connected to a screw rod (4) through the internal thread, and one end of the screw rod (4) extending out of the outer sleeve (5) is connected to a back cap (7).

3. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: One end of the spring latch (2) is inserted into the positioning tube latch hole (101) and connected to a stop ring (202), the outer diameter of the stop ring (202) being larger than the inner diameter of the positioning tube latch hole (101) and smaller than the inner diameter of the liner tube latch hole, and being used to prevent the spring latch (2) from withdrawing from the positioning tube latch hole (101).

4. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: The inner liner tube has two pin holes which are symmetrical with respect to the axis of the positioning tube (1).

5. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: The inclination angle of the slope section (301) is 20°-30°.

6. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 5, characterized in that: One end of the spring latch (2) in contact with the slope section (301) is also provided with a slope, and the inclination angle of the write slope is the same as the inclination angle of the slope section (301).

7. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: The screw rod (4) is a screw rod with a strength grade of 12.

9.

8. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: The main body material of the positioning cylinder (1) and the spring latch (2) is 17-4 stainless steel.

9. The extraction tool for a ceramic lined pipe with a round hole and a smooth inner wall without steps according to claim 1, characterized in that: The cross section of the outer wall of the end of the positioning tube (1) that is not inserted into the liner tube (8) is polygonal.

10. A method for extracting a ceramic lined pipe with a round hole having a smooth inner wall without steps using the extraction tool as claimed in any one of claims 3 to 9, comprising the following steps: Step 1: Install the spring latch (2) into the latch hole (101) of the positioning tube, and install the stop ring (202); install the positioning tube (1) into the inner liner tube (8), and adjust the position so that the latch hole of the inner liner tube and the latch hole (101) of the positioning tube are aligned; then push the locking cone (3) into the inner hole of the positioning tube (1), so that the spring latch (2) passes through the latch hole of the inner liner tube; Step 2: Rotate the positioning tube (1) to expose one end of the inner lining tube (8), drive the spring latch (2) and the inner lining tube (8) to rotate, so that the inner lining tube (8) is loosened to eliminate the sticking state, and then the inner lining tube (8) is pulled out; Step three, after completing step one, without pulling out the inner liner tube (8) by rotating the positioning tube (1), the screw rod (4) is installed into the end of the positioning tube (1) provided with an internal thread, and then the outer sleeve (5) is installed, and the part of the screw rod (4) exposed from the outer sleeve (5) is connected to the hollow hydraulic jack (6), and then the back cap (7) is installed to the end of the screw rod (4) extending out of the hollow hydraulic jack (6), and the back cap (7) is applied with a thrust through the hollow hydraulic jack (6) to drive the screw rod (4), and the screw rod (4) drives the positioning tube (1), the spring latch (2) and the inner liner tube (8), and the inner liner tube (8) is pulled out.

Images