Middle large debonding combustion chamber structure

Abstract

The invention discloses a middle large debonding combustion chamber structure which comprises a shell, a heat insulation layer, a lining layer and a grain, the grain is firmly bonded with the heat insulation layer through the lining layer, the heat insulation layer is bonded with the head and the tail of the shell, the middle of the shell is not bonded, and the interface of the heat insulation layer and the shell is in a free debonding state at the non-bonding part. The stress of the solid grain is released through free debonding at the interface of the heat insulating layer of the barrel section and the shell, the problem of debonding of the interface of a propellant / lining / heat insulating layer caused by deformation of the solid grain in curing cooling and low-temperature harsh environments is solved, the charging structure is effectively prevented from being damaged, and the service life of the solid grain is prolonged. And meanwhile, compared with a traditional combustion chamber in which grains are freely filled, the structure is simpler in process, the production period can be greatly shortened, the cost is lower, and high universality is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engine combustion chamber structure design, and in particular relates to a combustion chamber structure with a large middle debonding portion. Background Art

[0002] The charge in the combustion chamber is one of the important parts of the solid rocket engine structure. The integrity of the solid propellant charge structure is directly related to the thrust performance and reliability of the engine. When the end-burning solid grain is cooled and solidified in a harsh low-temperature environment, the grain shape will shrink inward due to the stress generated inside, causing the charge interface (propellant / liner / insulation layer) between the grain and the insulation layer to debond, resulting in charge defects, which will lead to an abnormal increase in the combustion surface of the engine during operation, causing a sudden increase in thrust and pressure.

[0003] At present, free-loading grains with coating sleeves are mainly used as a means to prevent solid grains from producing charging defects due to debonding at the interface of propellant / liner / insulation layer. However, the setting of the coating sleeve not only reduces the charge amount of the engine, but also increases the difficulty of charge design. If the gap between the coating sleeve and the insulation layer is too small, it is not conducive to the charging of the grain. If it is too large, it will lead to an increase in gas in the gap, which is not conducive to thermal protection, and the reliability of the combustion chamber will be reduced. In addition, the free-loading grain column needs to consider the assemblability. When it interferes with the insulation layer and is difficult to load, it needs to be manually polished before loading. Compared with wall casting, the combustion chamber production cycle of the free-loading grain column is longer and the process is more complicated. Summary of the invention

[0004] In order to overcome the deficiencies in the prior art, the present invention provides a combustion chamber structure with a large middle debonding. Through the free debonding at the interface between the barrel section insulation layer and the shell, the stress of the solid grain is released, and the problem of debonding at the interface of the propellant / liner / insulation layer caused by deformation of the solid grain during curing cooling and low-temperature harsh environments is solved. The damage of the charge structure is effectively prevented, which is beneficial to improving the working reliability of the solid rocket engine. At the same time, compared with the traditional combustion chamber with free loading of grain, the structure and process are simpler, can greatly shorten the production cycle, have lower costs and have higher versatility.

[0005] The specific technical solutions of the present invention are as follows:

[0006] A combustion chamber structure with a large middle debonding portion comprises a shell, an insulating layer, a lining layer and a charge, wherein the charge is firmly bonded to the insulating layer through the lining layer, the insulating layer is bonded to the head and tail of the shell, but not to the middle portion, and the interface between the insulating layer and the shell is in a free debonding state in the non-bonded portion.

[0007] The free debonding state at the interface between the thermal insulation layer and the middle section of the shell has the effect of releasing the stress of the charge column to prevent debonding at the interface between the charge column and the thermal insulation layer, which may lead to damage to the charge structure.

[0008] Preferably, the length of the free debonding portion of the thermal insulation layer accounts for 82% of the total length of the drug column.

[0009] Preferably, the thermal insulation layer is EPDM rubber.

[0010] Preferably, the lining layer is made of an adhesive that has good bonding with the insulation layer material.

[0011] Preferably, the shell is made of high-strength alloy steel.

[0012] Preferably, the head, middle and tail of the shell are respectively a front head, a cylinder section and a rear head, and each part is welded by vacuum electron beam welding.

[0013] Preferably, the charge is a solid propellant.

[0014] Preferably, the charge column is an end-burning solid charge column, the inner diameter of the charge column is φ282mm~φ282mm, the length is 3172mm, and the elongation rate is greater than 40%.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The combustion chamber structure provided by the present invention effectively releases the stress of the solid grain caused by temperature change through free debonding at the interface between the barrel insulation layer and the shell, avoids debonding at the charge interface between the propellant and the insulation layer, ensures the integrity of the charge structure, and is conducive to improving the working reliability of the solid rocket engine;

[0017] (2) Compared with the conventional combustion chamber using free-loading powder columns, the combustion chamber structure provided by the present invention avoids the need to set a coating sleeve, which not only eliminates the risk caused by the unreasonable gap between the coating sleeve and the insulation layer, but also simplifies the production process. At the same time, it avoids the limitation that the combustion chamber of the free-loading powder column must have a large opening at one end. The front and rear joints of the combustion chamber shell provided by the present invention can change the opening size according to the actual task requirements, and have high versatility.

[0018] (3) The grain of the present invention is reliably bonded to the insulation layer through the lining layer, and the insulation layer is reliably bonded to the head and tail of the shell, which effectively ensures that the grain will not be displaced relative to the shell during the transportation of the engine;

[0019] (4) The new combustion chamber structure provided by the present invention has the advantages of simple structure, strong operability and high filling ratio, which is conducive to achieving cost reduction and efficiency improvement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions disclosed in the present invention, the following briefly introduces the drawings required to be used in some embodiments disclosed in the present invention. Obviously, the drawings described below are only drawings of some embodiments disclosed in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the products involved in the embodiments disclosed in the present invention, the actual process of the method, etc.

[0021] Figure 1 A front half-section view of a large middle debonding combustion chamber structure provided by an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the debonding position of a large middle debonding combustion chamber structure provided in an embodiment of the present invention.

[0023] The accompanying drawings are marked as follows: 1. Shell; 2. Insulation layer; 3. Lining layer; 4. Grain. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] The present invention provides a combustion chamber structure with a large middle debonding, comprising a shell, an insulating layer, a lining, and a charge, wherein the charge is firmly bonded to the insulating layer through the lining, the insulating layer is bonded to the head and tail of the shell, and the middle part is not bonded, and the interface between the insulating layer and the shell is in a free debonding state in the non-bonded part.

[0026] The free debonding state at the interface between the thermal insulation layer and the middle section of the shell has the effect of releasing the stress of the charge column to prevent debonding at the interface between the charge column and the thermal insulation layer, which may lead to damage to the charge structure.

[0027] Preferably, the length of the free debonding portion of the thermal insulation layer accounts for 82% of the total length of the drug column.

[0028] Preferably, the thermal insulation layer is EPDM rubber.

[0029] Preferably, the lining layer is made of an adhesive that has good bonding with the insulation layer material.

[0030] Preferably, the shell is made of high-strength alloy steel.

[0031] Preferably, the head, middle and tail of the shell are respectively a front head, a cylinder section and a rear head, and each part is welded by vacuum electron beam welding.

[0032] Preferably, the charge is a solid propellant.

[0033] Preferably, the charge column is an end-burning solid charge column, the inner diameter of the charge column is φ282mm~φ282mm, the length is 3172mm, and the elongation rate is greater than 40%.

[0034] Example

[0035] like Figure 1 As shown, an embodiment of the present invention provides a large middle debonding combustion chamber structure, comprising a shell (1), an insulation layer (2), a lining (3), and a charge (4).

[0036] The shell (1) is made of high-strength alloy steel and adopts a front head + barrel section + rear head design, and each section is welded by vacuum electron beam welding; the inner surface of the combustion chamber shell (1) after the above molding is sandblasted to make the inner surface rough, so as to improve the bonding performance between the insulation layer (2) and the shell (1); adhesive is evenly sprayed on the head and tail of the shell (1), that is, the front head + part of the barrel section where it connects with the front head and the rear head + part of the barrel section where it connects with the rear head; the insulation layer (2) is firmly bonded to the head and tail of the shell (1) by air bag pressurization, and the remaining parts are debonded, and the specific debonding positions are as follows: Figure 2 As shown, the insulation layer (2) is not bonded to the shell (1) from point a to point b, and is in a free debonding state. The length from a to b is 2600 mm, accounting for 82% of the total length of the charge (4), so as to release the stress of the charge and effectively prevent the damage to the charge structure.

[0037] The shell (1) to which the insulation layer (2) is bonded is placed in an oven for curing. The curing conditions are: oven temperature +60°C, and the shell is allowed to stand in the oven for curing for 5-7 days. The inner surface of the cured insulation layer (2) is roughened, and then a lining layer (3) (i.e., an adhesive layer) is evenly coated. Finally, a charge column (4) is vacuum-casted onto the inner surface of the lining layer (3). The entire assembly is placed in an oven for curing to obtain a combustion chamber. The curing conditions are: oven temperature +60°C, and the shell is allowed to stand in the oven for curing for 5-7 days.

[0038] The material of the thermal insulation layer (2) is EPDM rubber, and the complex profiles of the head and tail are manufactured by an aluminum alloy mold, and polytetrafluoroethylene is sprayed on the surface of the mold. The barrel section adopts a variable thickness design method according to the exposure time to the combustion gas, which can effectively prevent heat from being transferred to the shell (1) and play a role in protecting the shell (1); the grain (4) is a solid propellant, and the grain shape is an end-burning solid grain, and the elongation is greater than 40%, which meets the axial and radial deformation rates of the grain.

[0039] Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the above disclosed content without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall belong to the protection scope of the technical solution of the present invention. The protection scope of the present invention shall be subject to the attached claims.

[0040] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A combustion chamber structure with a large middle debonding, comprising a shell (1), a heat insulating layer (2), a lining layer (3), and a charge (4), wherein the charge (4) is firmly bonded to the heat insulating layer (2) through the lining layer (3), and is characterized in that: The heat insulating layer (2) is bonded to the head and tail of the shell (1), but not bonded to the middle portion; the interface between the heat insulating layer (2) and the shell (1) is in a free debonding state at the non-bonded portion.

2. A large middle debonding combustion chamber structure according to claim 1, characterized in that: The free debonding state at the interface between the heat insulating layer (2) and the middle section of the shell (1) has the function of releasing the stress of the charge (4), and is used to prevent the interface between the charge (4) and the heat insulating layer (2) from debonding, thereby preventing the charge structure from being damaged.

3. The large middle debonding combustion chamber structure according to claim 1 is characterized in that: The length of the free debonding portion of the thermal insulation layer (2) accounts for 82% of the total length of the drug column (4).

4. The large middle debonding combustion chamber structure according to claim 1 is characterized in that: The heat insulating layer (2) is EPDM rubber.

5. The large middle debonding combustion chamber structure according to claim 1 is characterized in that: The lining layer (3) is made of an adhesive that has excellent bonding with the material of the thermal insulation layer (2).

6. The large middle debonding combustion chamber structure according to claim 1, characterized in that: The shell (1) is made of high-strength alloy steel.

7. The large middle debonding combustion chamber structure according to claim 1 is characterized in that: The head, middle and tail of the shell (1) are respectively a front head, a cylinder section and a rear head, and each part is welded by vacuum electron beam welding.

8. The large middle debonding combustion chamber structure according to claim 1 is characterized in that: The drug column (4) is a solid propellant.

9. A large middle debonding combustion chamber structure according to claim 1 or 8, characterized in that: The type of the drug column (4) is an end-burning solid drug column, the inner diameter of the drug column is φ282mm~φ282mm, the length is 3172mm, and the elongation rate is greater than 40%.

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