A nozzle throat insert press fitting device and method

Abstract

The application provides a nozzle throat insert press-fitting device and method, which comprises a bottom plate and a top press plate arranged in parallel and coaxially, and a pressure fitting element arranged between the bottom plate and the top press plate; the pressure fitting element comprises a positioning press plate and a pressure sensor coaxially arranged on the positioning press plate, and the lower end surface of the positioning press plate is completely attached to the top outer surface of the throat insert; the top press plate is coaxially arranged with the pressure sensor and closely attached to the pressure sensor, and the top press plate is used for applying pressure to the throat insert through the pressure fitting element; the bottom plate is used for placing a nozzle assembly, and the bottom plate and the top press plate are connected through a plurality of connecting elements which are uniformly and centrally symmetrically arranged, and the connecting elements are used for changing the distance between the bottom plate and the top press plate so as to control the pressure applied to the throat insert. The application can ensure that the throat insert and the nozzle assembly always bear axial vertical force during press fitting, improve the press fitting precision, and ensure the press fitting quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid rocket engine parts, in particular to a nozzle throat liner body press-fitting device and method. BACKGROUND

[0002] The nozzle of a solid rocket engine is a part that converts the energy of the combustion chamber into kinetic energy by controlling the expansion of the exhaust gas, thereby providing thrust to the aircraft. The nozzle is an important energy conversion device during the operation of the solid rocket engine, and is assembled from multiple parts. The throat liner of the nozzle is located at the throat of the nozzle, and its ablation state is the most severe. The inner surface of the throat liner is damaged by the ablation of the high-temperature, high-pressure, high-speed and corrosive particle heat flow, which is manifested as an enlarged throat diameter, a rough and uneven surface, an irregular profile, etc. Especially at the moment of engine ignition, the throat liner is heated at a speed of more than 2000℃ / s from room temperature, resulting in a large temperature gradient and thermal stress, which easily causes cracks or ruptures in the throat liner, thereby directly affecting the thrust and efficiency of the engine, and even losing the working ability.

[0003] The press-fitting of the throat liner in the nozzle assembly is a key link in the production of the nozzle. The stress condition and assembly gap during the press-fitting of the throat liner will affect the production quality of the nozzle, thereby affecting the operation of the engine. Currently, the press-fitting of the nozzle throat liner is generally performed on a numerical control press, and the nozzle semi-finished product needs to be placed on the equipment. At the same time, the pressurization and solidification time of the press-fitting of the throat liner is more than 96h, which often causes product accumulation, delays the construction period, and the cost of purchasing the numerical control press is too high. SUMMARY

[0004] The purpose of the present application is to provide a nozzle throat liner press-fitting device and method to overcome the defects of the prior art.

[0005] In order to solve the above technical problems, in a first aspect, the present application provides a nozzle throat liner press-fitting device, comprising a bottom plate and a top pressing plate arranged in parallel and coaxially, and a pressure fitting part arranged between the bottom plate and the top pressing plate.

[0006] The pressure fitting part comprises a positioning pressing plate and a pressure sensor coaxially arranged on the positioning pressing plate, and the shape of the lower end surface of the positioning pressing plate is adapted to the shape of the top outer surface of the throat liner, so as to completely fit the top outer surface of the throat liner.

[0007] The top pressing plate is coaxially arranged with the pressure sensor, and the top pressing plate is in close contact with the pressure sensor. The top pressing plate is used to apply pressure to the throat liner through the pressure fitting part.

[0008] The bottom plate is used to place the nozzle assembly, and the bottom plate and the top pressing plate are connected by a plurality of connecting pieces. The plurality of connecting pieces are uniformly and centrally symmetrically arranged, and the connecting pieces are used to change the distance between the bottom plate and the top pressing plate, thereby controlling the size of the pressure applied to the throat liner.

[0009] The present application can ensure that the throat liner and the nozzle assembly always bear axial vertical force during pressure fitting, improve pressure fitting precision, and ensure pressure fitting quality by arranging the top pressing plate, the bottom plate, the positioning pressing plate, and the pressure sensor coaxially.

[0010] Further, the positioning pressing plate comprises a bottom pressing plate and a sleeve, the sleeve is arranged on the upper end face of the bottom pressing plate, the lower end face of the bottom pressing plate is used for completely matching the top outer surface of the throat liner, the pressure sensor is arranged in the sleeve, and the inner wall of the sleeve matches the outer wall of the pressure sensor.

[0011] The present application can prevent the horizontal movement of the pressure sensor and ensure the vertical force of the pressure sensor by arranging the pressure sensor in the sleeve.

[0012] Further, the upper end face of the bottom pressing plate is coaxially provided with a downwardly recessed positioning table, the sleeve is arranged on the positioning table, and the positioning table is used for limiting the horizontal displacement of the sleeve.

[0013] The present application can prevent the horizontal displacement of the sleeve by arranging the positioning table.

[0014] Further, the upper end face of the bottom plate is coaxially provided with an annular limiting groove, and the limiting groove is used for limiting the horizontal displacement of the nozzle assembly.

[0015] The present application can prevent the horizontal displacement of the nozzle assembly by arranging the limiting groove on the bottom plate.

[0016] In the second aspect, the present application provides a nozzle throat liner pressure fitting method, comprising:

[0017] S1, the throat liner and the nozzle assembly are trial fitted, and the actual gap value of each bonding surface between the throat liner and the nozzle assembly is detected;

[0018] S2, the critical pressure value when the throat liner is pressure fitted is calculated;

[0019] S3, according to the actual gap value measured in step S1, the bonding surface of the throat liner and / or the nozzle assembly is smeared with putty;

[0020] S4, after the throat liner and the nozzle assembly are butt jointed, they are put into the nozzle throat liner pressure fitting device, and the nozzle throat liner pressure fitting device is used to pressure fit the throat liner and the nozzle assembly.

[0021] Further, the step S1 comprises: the bonding surface between the throat insert and the nozzle assembly comprises a gap surface and a fit surface, wherein the fit surface is a contact stress surface and the gap surface is a non-stress surface; the actual gap value of the fit surface is detected to be zero, and the actual gap value of the gap surface is detected to be within the range of the theoretical gap value.

[0022] The present application can judge whether the throat insert and the nozzle assembly meet the assembly standard in advance by trial fitting the throat insert and the nozzle assembly, so as to prevent the nozzle formed by the throat insert and the nozzle assembly which do not meet the assembly standard from not meeting the use requirement after pressure fitting.

[0023] Further, the step S2 comprises: calculating the area S of the fit surface of the throat insert and the nozzle assembly S = π (D1 / 2) 2 - π (D2 / 2) 2 According to P = (F + F1) / S ≤ P1, F ≤ P1 * S - F1, wherein D1 is the outer diameter of the fit surface, D2 is the inner diameter of the fit surface, P is the pressure received by the nozzle assembly, F is the pressure applied by the nozzle throat insert pressure fitting device, F1 is the weight of the throat insert, and P1 is the safe compression strength that can be borne by the throat insert and the nozzle assembly.

[0024] The present application can prevent the damage of the throat insert or the nozzle assembly caused by excessive pressure by calculating the maximum pressure that can be applied by the nozzle throat insert pressure fitting device.

[0025] Further, the step S3 comprises: after smearing a layer of putty on the fit surfaces of the throat insert and the nozzle assembly and then wiping off the putty, smearing the putty only on the gap surface of the throat insert for the gap surface with an actual gap value less than 0.1 mm, and smearing the putty on the gap surfaces of the throat insert and the nozzle assembly for the gap surface with an actual gap value not less than 0.1 mm.

[0026] The present application can ensure that the gap between the throat insert and the nozzle assembly is completely filled with the putty by smearing the putty on the gap surfaces of the throat insert and the nozzle assembly according to the size of the actual gap value, and the putty has the characteristic of resisting ablation, so as to prevent the flame from penetrating into the gap when the solid rocket engine is ignited.

[0027] Further, the step S4 comprises: after the throat insert is pressurized to the preset pressure by the nozzle throat insert pressure fitting device and the pressure is maintained, the actual gap value of the outermost bonding surface between the throat insert and the nozzle assembly is measured; if the actual gap value of the outermost bonding surface between the throat insert and the nozzle assembly is greater than the theoretical gap value, the pressurization and pressure maintenance are continued and the actual gap value is measured again until the actual gap value is within the range of the theoretical gap value, then the last pressurization and pressure maintenance are performed, and the final pressure value is less than the critical pressure value.

[0028] The present application gradually reaches the theoretical gap value of the pressure fitting of the throat lining and the nozzle assembly through repeated pressurization, pressure maintaining and measurement, which is beneficial to improve the pressure fitting precision and effect; and the throat lining and the nozzle assembly are not damaged in the pressure fitting process by controlling the final pressure maintaining pressure value to be less than the critical pressure value

[0029] Further, in step S4, after each pressure maintaining of the throat lining, a plurality of actual gap values are measured along the outermost bonding surface, the plurality of actual gap values are compared, and if the maximum difference of the plurality of actual gap values is greater than 0.02 mm, the connecting member of the nozzle throat lining pressure fitting device is adjusted so that the throat lining is vertically pressed towards the nozzle assembly.

[0030] The present application can determine whether the pressure received by the throat lining is vertically downward by measuring a plurality of actual gap values along the outermost bonding surface, and the connecting member can be fine-tuned according to the size of the plurality of actual gap values, so as to adjust the stress condition of the throat lining.

[0031] The present application has the following beneficial effects: the present application provides a nozzle throat lining pressure fitting device, which can ensure that the throat lining and the nozzle assembly always bear axial vertical force during pressure fitting by coaxially arranging the top pressing plate, the bottom plate, the positioning pressing plate and the pressure sensor, thereby improving the pressure fitting precision and ensuring the pressure fitting quality; the pressure sensor is used for monitoring the applied pressure to prevent the throat lining and the nozzle assembly from being damaged by excessive pressure; the bottom plate and the top pressing plate are connected by a plurality of connecting members, and the applied pressure of the top pressing plate can be accurately adjusted by adjusting the connecting members. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 Fig. 1 is a structural schematic diagram of the present application nozzle;

[0033] Figure 2 Fig. 2 is a structural schematic diagram of the present application nozzle throat lining pressure fitting device in use;

[0034] Figure 3 Fig. 3 is a structural schematic diagram of the present application throat lining.

[0035] Fig. 1 is a structural schematic diagram of the present application nozzle; DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0037] As Figure 1As shown in the drawings, the nozzle of the solid rocket engine comprises a throat liner and a nozzle assembly, the throat liner comprises a throat liner 1 and a back liner 2, the cross sections of the throat liner 1 and the back liner 2 are annular, the back liner 2 is fixedly arranged on the outer periphery of the throat liner 1, and the nozzle assembly comprises a diffusion section heat insulation layer 5, a nozzle shell 4 and an inverted cone heat insulation layer 3 arranged layer by layer from inside to outside, and the cross sections of the diffusion section heat insulation layer 5, the nozzle shell 4 and the inverted cone heat insulation layer 3 are annular.

[0038] As shown in the drawings, Figure 1 , 3 the throat liner comprises 11 bonding surfaces of B, C, D, E, F, G, H, J, K, P and L, and the nozzle assembly also corresponds to the 11 bonding surfaces, wherein the bonding surface H is a force surface during press fitting, the bonding surface H of the throat liner is completely attached to the corresponding bonding surface of the nozzle assembly without leaving a gap, and the other bonding surfaces of the throat liner and the corresponding bonding surfaces of the nozzle assembly all leave gaps, and the gaps are bonded by D03 putty.

[0039] As shown in the drawings, Figure 2 the nozzle throat liner press fitting device provided by the embodiment comprises a bottom plate 12 and a top pressing plate 6 arranged coaxially in parallel and a pressure fitting part arranged between the bottom plate 12 and the top pressing plate 6.

[0040] The pressure fitting part comprises a positioning pressing plate and a pressure sensor 10 arranged coaxially on the positioning pressing plate, the positioning pressing plate comprises a bottom pressing plate 11 and a sleeve 9, a downwardly recessed positioning table is arranged coaxially on the upper end surface of the bottom pressing plate 11, the sleeve 9 is movably arranged on the positioning table, the inner wall of the positioning table is tightly attached to the outer wall of the sleeve 9, the positioning table is used for limiting the horizontal displacement of the sleeve 9, the shape of the lower end surface of the bottom pressing plate 11 is adapted to the shape of the top outer surface of the throat liner, and the bottom pressing plate 11 is used for being completely attached to the top outer surface of the throat liner, and the pressure sensor 10 is arranged in the sleeve 9, and the inner wall of the sleeve 9 is attached to the outer wall of the pressure sensor 10.

[0041] A hole is formed in the sleeve 9, the pressure sensor 10 is connected with an external pressure instrument display 13 through the hole formed in the sleeve 9, and the current pressure is displayed.

[0042] The top pressing plate 6 is arranged coaxially with the pressure sensor 10, the top pressing plate 6 is tightly attached to the pressure sensor 10, and the top pressing plate 6 is used for applying pressure to the throat liner through the pressure fitting part.

[0043] A ring-shaped limiting groove is coaxially formed in the upper end surface of the bottom plate 12, the nozzle assembly is placed in the limiting groove, the limiting groove is used for limiting the horizontal displacement of the nozzle assembly, the bottom plate 12 and the top pressing plate 6 are connected through a plurality of connecting parts, in the embodiment, the connecting parts are screw rods 8, the plurality of connecting parts are uniformly and centrally arranged, the distance between the bottom plate 12 and the top pressing plate 6 can be changed by rotating the nuts 7 on the screw rods 8, so that the size of the pressure applied to the throat liner is controlled, and the vertical downward pressure applied by the top pressing plate 6 can be ensured by fine adjustment of each nut 7.

[0044] The embodiment also provides a method for pressing the nozzle throat liner, comprising:

[0045] S1, fitting the throat liner with the nozzle assembly: vertically placing the nozzle assembly, coaxially placing the throat liner on the upper end of the nozzle assembly, and detecting the actual gap values of each bonding surface between the throat liner and the nozzle assembly.

[0046] The bonding surface between the throat liner and the nozzle assembly includes a gap surface and a fitting surface, wherein the fitting surface is a stress contact surface, i.e. Figure 3 the bonding surface H in the formula (1), and the gap surface is a non-stress surface, i.e. all the bonding surfaces except the bonding surface H in the formula (2), the actual gap value of the fitting surface should be detected to see whether it is zero, and the actual gap value of the gap surface should be detected to see whether it is within the theoretical gap value range, wherein the theoretical gap value range of each gap surface is as follows: the bonding surface B: 0.08-0.12 mm, the bonding surface C: 0.05-0.10 mm (single side), the bonding surface D: 0.03-0.08 mm, the bonding surface E: 0.03-0.08 mm (single side), the bonding surface F: 0.05-0.10 mm, the bonding surface G: 0.05-0.10 mm (single side), the bonding surface J: 0.03-0.08 mm (single side), the bonding surface K: 0.03-0.08 mm, the bonding surface L: 0.03-0.08 mm (single side), and the bonding surface P: 0.05-0.15 mm. The gap value of the single side refers to the difference between the radii of two cylindrical surfaces, for example, the bonding surface C is a cylindrical surface, and thus the actual gap value of the single side is considered, and the bonding surface D is not a cylindrical surface, and thus the actual gap value of the single side is not considered.

[0047] Since there is no putty between the throat liner and the nozzle assembly at this time, after the throat liner is coaxially placed on the nozzle assembly, the bonding surface H of the throat liner directly fits the corresponding bonding surface of the nozzle assembly, and the remaining bonding surfaces have gaps. If the bonding surface H cannot be fitted or the actual gap value of the gap surface is not within the theoretical gap value range, the throat liner or the nozzle assembly can be replaced.

[0048] S2, calculating the critical pressure value when the throat liner is pressed: calculating the area S of the fitting surface of the throat liner and the nozzle assembly = π(D1 / 2) 2 - π(D2 / 2) 2 , according to P = (F + F1) / S ≤ P1, F ≤ P1·S - F1, wherein D1 is the outer diameter of the fitting surface, i.e. the outer diameter of the bonding surface H, D2 is the inner diameter of the fitting surface, i.e. the inner diameter of the bonding surface H, P is the pressure received by the nozzle assembly, F is the pressure applied by the nozzle throat liner pressing device, F1 is the weight of the throat liner itself, and P1 is the safe compression strength that can be borne by the throat liner and the nozzle assembly;

[0049] In the embodiment, S = 3985.4 mm 2 .

[0050] The throat liner body self-weight F1 = 21.8 KN.

[0051] The throat liner 1 material Z-direction compressive strength is ≥ 160 MPa, the back liner 2 Z-direction compressive strength is ≥ 54 MPa, taking the minimum value 54 MPa, P1 = 54 MPa.

[0052] It is calculated that F ≤ 193.4 KN, so in the process of pressing, the pressure instrument display 13 shows that the pressure is less than 193.4 KN, which will not cause damage to the product.

[0053] S3, according to the actual gap value measured in step S1, the bonding surface of the throat liner and / or the nozzle assembly is smeared with putty; after the bonding surface H of the throat liner and the corresponding bonding surface of the nozzle assembly are smeared with a layer of putty, they are wiped clean; for the gap surface with an actual gap value less than 0.1 mm, putty is only smeared on the gap surface of the throat liner; for the gap surface with an actual gap value not less than 0.1 mm, putty is smeared on the gap surface of the throat liner and the corresponding gap surface of the nozzle assembly; this can ensure that the gap between the throat liner and the nozzle assembly is completely filled with putty, and the putty has the characteristics of resisting ablation, which can prevent the flame from penetrating into the gap when the solid rocket engine is ignited.

[0054] S4, after the throat liner and the nozzle assembly are butted, they are slowly placed on the bottom plate 12 of the nozzle throat liner pressing device, the bottom pressing plate 11 is placed vertically on the upper end surface of the throat liner, then the sleeve 9 and the pressure sensor 10 are installed, the initial pressure of the pressure sensor 10 is set to zero, the top pressing plate 6 is lifted and aligned, then the top pressing plate 6 is connected with the bottom plate 12 by using the nut 7.

[0055] After the throat liner is pressurized to the preset pressure by rotating the nut 7, the pressure is maintained, in this embodiment, the preset pressure is 10 KN, the actual gap value of the outermost bonding surface between the throat liner and the nozzle assembly is measured, the outermost bonding surface is the bonding surface B, if the actual gap value of the outermost bonding surface between the throat liner and the nozzle assembly is greater than the theoretical gap value, the pressure is continuously increased, maintained and measured again, in this embodiment, the pressure is increased by 5 KN each time, until the actual gap value is within the range of the theoretical gap value, then the pressure is increased for the last time and maintained, in this embodiment, the last time the pressure is increased by 3 KN, but the final pressure value during the maintenance should be less than the critical pressure value, the pressure value during the maintenance is recorded, the gap value of the bonding surface B is re-measured after four hours, and any violation operation such as pressure supplementing, display value adjusting and the like during the solidification process is strictly prohibited, and the pressure value change during the solidification process should be recorded. During the solidification process, the temperature should be maintained at 18-25℃, and the solidification time is more than 96 h, after the overflowed putty is completely solidified, the nozzle throat liner pressing device can be disassembled, and the solidification start and end time are recorded.

[0056] It should be noted that after each time the throat liner is pressed, the actual gap values are measured along the outermost bonding surface in a ring shape, the actual gap values are compared, and if the maximum difference among the actual gap values is greater than 0.02 mm, the connecting piece of the nozzle throat liner press-fitting device is adjusted so that the throat liner is vertically pressed against the nozzle assembly. In addition, whether the outermost bonding surface between the throat liner and the nozzle assembly has a uniform circle of putty overflow can be observed to determine whether the throat liner is vertically pressed against the nozzle assembly.

[0057] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the foregoing embodiments of the present application are described in detail, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for press-fitting a nozzle throat liner, characterized in that, include: S1. Test-fit the throat liner and the nozzle assembly, and check the actual gap value of each bonding surface between the throat liner and the nozzle assembly. Step S1 includes: the bonding surface between the throat liner and the nozzle assembly includes a gap surface and a mating surface, wherein the mating surface is the contact force surface and the gap surface is the non-force surface; the actual gap value of the mating surface is detected as zero; and the actual gap value of the gap surface is detected as within the theoretical gap value range. S2. Calculate the critical pressure value during throat liner press-fitting; S3. Apply putty to the bonding surface of the throat liner and / or nozzle assembly based on the actual gap value measured in step S1. Step S3 includes: applying a layer of putty to both the mating surface of the throat liner and the mating surface of the nozzle assembly, and then scraping it clean. For gap surfaces with an actual gap value of less than 0.1 mm, putty is applied only to the gap surface of the throat liner. For gap surfaces with an actual gap value of not less than 0.1 mm, putty is applied to both the gap surface of the throat liner and the gap surface of the nozzle assembly. S4. After connecting the throat liner and the nozzle assembly, place them into the nozzle throat liner pressing device and use the nozzle throat liner pressing device to press and fit the throat liner and the nozzle assembly. Step S4 includes: pressurizing the throat liner to a preset pressure using a nozzle throat liner press-fitting device and holding the pressure; measuring the actual gap value of the outermost bonding surface between the throat liner and the nozzle assembly; if the actual gap value of the outermost bonding surface between the throat liner and the nozzle assembly is greater than the theoretical gap value, then continue to pressurize, hold the pressure and measure again until the actual gap value is within the range of the theoretical gap value, then perform a final pressurization and hold the pressure, and finally hold the pressure value less than the critical pressure value.

2. The nozzle throat liner press-fitting method according to claim 1, characterized in that: Step S2 includes: calculating the area S = π(D1 / 2) of the mating surface between the throat liner and the nozzle assembly. 2 -π(D² / 2) 2 According to P=(F+F1) / S≤P1, we have F≤P1·S-F1, where D1 is the outer diameter of the mating surface, D2 is the inner diameter of the mating surface, P is the pressure on the nozzle assembly, F is the pressure applied by the nozzle throat liner press fitting device, F1 is the weight of the throat liner itself, and P1 is the safe compressive strength that the throat liner and nozzle assembly can withstand.

3. The nozzle throat liner press-fitting method according to claim 1, characterized in that: In step S4, after each pressure holding of the throat liner, multiple actual gap values ​​are uniformly measured circumferentially along the outermost bonding surface. The magnitudes of the multiple actual gap values ​​are compared. If the maximum difference among the multiple actual gap values ​​is greater than 0.02mm, the connector of the nozzle throat liner pressing device is adjusted so that the throat liner is vertically pressed against the nozzle assembly.

4. A nozzle throat liner press-fitting apparatus for implementing the nozzle throat liner press-fitting method according to any one of claims 1 to 3, characterized in that: It includes a base plate (12) and a top pressure plate (6) arranged in parallel and coaxially, and a pressure fitting between the base plate (12) and the top pressure plate (6); The pressure fitting component includes a positioning pressure plate and a pressure sensor (10) coaxially mounted on the positioning pressure plate. The shape of the lower end face of the positioning pressure plate is adapted to the shape of the top outer surface of the throat liner, so as to completely fit with the top outer surface of the throat liner. The top pressure plate (6) is arranged coaxially with the pressure sensor (10), the top pressure plate (6) is in close contact with the pressure sensor (10), and the top pressure plate (6) is used to apply pressure to the throat liner through the pressure fitting; The base plate (12) is used to place the nozzle assembly. The base plate (12) and the top pressure plate (6) are connected by multiple connectors. The multiple connectors are evenly and centrally symmetrically arranged. The connectors are used to change the distance between the base plate (12) and the top pressure plate (6) to control the pressure applied to the throat liner.

5. The nozzle throat liner press-fitting device according to claim 4, characterized in that: The positioning pressure plate includes a bottom pressure plate (11) and a sleeve (9). The sleeve (9) is disposed on the upper end face of the bottom pressure plate (11). The lower end face of the bottom pressure plate (11) is used to completely fit the top outer surface of the throat liner. The pressure sensor (10) is disposed inside the sleeve (9). The inner wall of the sleeve (9) is fitted with the outer wall of the pressure sensor (10).

6. The nozzle throat liner press-fitting device according to claim 5, characterized in that: The bottom pressure plate (11) has a downwardly recessed positioning platform coaxially arranged on its upper end face. The sleeve (9) is arranged on the positioning platform, and the positioning platform is used to limit the horizontal displacement of the sleeve (9).

7. The nozzle throat liner press-fitting device according to any one of claims 4 to 6, characterized in that: The upper surface of the base plate (12) is coaxially provided with an annular limiting groove, which is used to limit the horizontal displacement of the nozzle assembly.

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