A lightweight quick-installation connection structure for an engine

Abstract

The invention discloses a lightweight quick-install connection structure for an engine, comprising an engine casing, a top cover, a positioning block and screws, wherein the engine casing is evenly designed with matching grooves along the circumference, each matching groove is divided into a load-bearing groove, an opening groove and an annular groove in sequence along the circumference, the top cover is designed with an equal number of load-bearing blocks corresponding to the load-bearing grooves of the engine casing, the bottom of the load-bearing groove of the engine casing and the bottom of the load-bearing block of the top cover are docking reference surfaces, the positioning block is a "Z"-shaped structural member, installed in the opening groove of the engine casing, wherein the lower end side surface of the positioning block presses the load-bearing block of the top cover into the corresponding load-bearing groove of the engine casing to prevent the load-bearing block of the top cover from rotating in the load-bearing groove of the engine casing; the upper end top surface of the positioning block is fixed in the annular groove of the engine casing by screws to fix the positioning block to the engine casing; the engine casing and the top cover are designed in a graduated load-bearing manner of a flange structure, and the load-bearing block of the top cover is embedded in the load-bearing groove of the casing to reduce the flange structure and realize a lightweight structure.

Description

Technical Field

[0001] The invention relates to a lightweight quick-installation connection structure for an engine, belongs to the technical field of solid rocket engines, is used for connecting an engine head and a fixed body, and is suitable for lightweight quick-installation connection of small low-pressure engines. Background Art

[0002] The connection structure of a solid rocket engine is a docking sealing device between the shell and the top cover. Common connection structures include flange connection and threaded connection. The main features of the flange connection are high strength and good sealing. Its installation method is to align the docking surface on the shell and the docking surface on the top cover, and fix them by applying a pre-tightening force of a certain torque through a large number of screws. However, when used for installation on the engine, the sealing surface is required to be flat. At the same time, due to the strength requirements of the threaded holes and through-hole structures designed and processed on the docking surface, the docking surface structure is usually relatively thick, resulting in a relatively large mass of the connection structure; the main feature of the threaded connection method is that the outer dimensions are small and self-locking can be easily achieved; its installation method is to align the internal thread on the shell and the external thread on the top cover (or the external thread on the shell and the internal thread on the top cover), rotate the top cover clockwise (or counterclockwise) and tighten it. When tightening, a large axial pre-tightening force is generated, which is beneficial to sealing. However, considering the connection strength, the number of turns of the threaded connection is large, and when applied to the engine, the mass of the connection structure is also relatively large. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a lightweight quick installation connection method to achieve quick installation connection between the engine housing and the top cover, which is suitable for small low-pressure working engines;

[0004] The technical solution of the present invention is:

[0005] A lightweight quick-installation connection structure for an engine, comprising an engine housing (1), a top cover (2), a positioning block (3) and a screw (4), wherein the engine housing (1) is evenly provided with matching grooves along the circumference, each matching groove being divided into a bearing groove (11), an opening groove (12) and an annular groove (13) in sequence along the circumference, the top cover (2) is provided with a number of bearing blocks (21) corresponding to the bearing grooves (11) of the engine housing (1), the bottom of the bearing grooves (11) of the engine housing (1) and the bottom of the bearing blocks (21) of the top cover (2) being butt joint reference surfaces, the positioning block (3) being a "Z"-shaped structural component, and being installed in the opening grooves (12) of the engine housing (1). ), wherein the lower end side surface of the positioning block (3) presses the load-bearing block (21) of the top cover (2) into the corresponding load-bearing groove (11) of the engine housing (1), thereby preventing the load-bearing block (21) of the top cover (2) from rotating in the load-bearing groove (11) of the engine housing (1); the upper end top surface of the positioning block (3) is fixed in the annular groove (13) of the engine housing (1) by means of screws (4), thereby fixing the positioning block (3) to the engine housing (1); the engine housing (1) and the top cover (2) are designed in a graduated load-bearing manner of a flange structure, and the load-bearing block (21) of the top cover (2) is embedded in the load-bearing groove (11) of the housing (1), thereby reducing the flange structure and achieving a lightweight structure;

[0006] The indexed load-bearing method includes determining the number and angle of the matching grooves of the engine housing (1), which are respectively: the number of matching grooves N = ▏k*(πRP) / σ ▏, wherein ▏ ▏ is a rounding symbol, k is a dimensionless coefficient, which is determined based on the material and working pressure of the engine housing (1) and has a value range of 1.7 to 4.6, P is the engine working pressure, σ is the allowable stress of the material, and R is the inner radius of the matching groove of the engine housing (1); the matching groove angle θ1 = ▏360 / N-θ0▏, wherein θ0 is an initial angle, which is determined based on the material and working pressure of the engine housing (1) and has a value range of 4° to 15°;

[0007] The positioning block (3) is made of forged metal, such as 30CrMnSiA or D406A;

[0008] The left side surface of the load-bearing block (21) is a butt joint surface (22) between the top cover (2) and the engine housing (1), and the right side surface of the load-bearing block (21) is a butt joint surface (23) between the top cover (2) and the positioning block (3);

[0009] The left side surface of the positioning block (3) is a docking stop surface (31) for connecting the top cover (2) and the housing (1); the right side hole of the positioning block (3) is a mounting positioning hole (32) for connecting the engine housing (1) and the positioning block (3) via screws (4);

[0010] The advantages of the present invention compared with the prior art are

[0011] (1) Compared with the flange connection structure, the structure is compact and lightweight; the design utilizes a graduated load-bearing method to reduce the thickness and weight of the structure;

[0012] (2) Compared with the threaded connection structure, the structure is quick and convenient to install and connect. During installation and connection, the load-bearing block on the top cover corresponds to the open groove on the engine casing, is pushed to the docking reference surface of the matching groove of the engine casing, and then rotated a certain angle to the seating surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments;

[0014] Figure 1 A schematic diagram of the lightweight quick-installation connection structure of the engine according to the present invention;

[0015] Figure 2 A structural diagram of an engine casing of the connection structure of the present invention;

[0016] Figure 3 A top cover structure diagram of the connection structure of the present invention;

[0017] Figure 4 A structural diagram of a positioning block of the connection structure of the present invention;

[0018] Figure 5 It is an assembly structure diagram of the engine housing and the top cover of the connection structure of the present invention;

[0019] Figure 6 This is a structural diagram of the engine housing, top cover, positioning block and screw assembly of the connection structure of the present invention;

[0020] Figure 7 It is a cross-sectional view of the engine housing, top cover, positioning block and screws of the connection structure of the present invention after being assembled;

[0021] Figure 8 A top view of the engine casing of the connection structure of the present invention;

[0022] Fig. 9 This is an end view of the engine casing of the connection structure described in the present invention. DETAILED DESCRIPTION

[0023] like Figure 1 and Figure 2As shown, the engine lightweight quick installation connection structure of the present invention comprises an engine housing (1), a top cover (2), a positioning block (3) and a screw (4), wherein the engine housing (1) is evenly provided with matching grooves along the circumference, and each matching groove is sequentially divided into a load-bearing groove (11), an opening groove (12) and an annular groove (13) along the circumference, and the top cover (2) is provided with a load-bearing block (21) of the same number as the load-bearing groove (11) of the engine housing (1), and the bottom of the load-bearing groove (11) of the engine housing (1) and the bottom of the load-bearing block (21) of the top cover (2) serve as a docking reference surface, and the positioning block (3) is a "Z"-shaped structural member, which is installed in the opening groove of the engine housing (1). (12), wherein the lower end side surface of the positioning block (3) presses the load-bearing block (21) of the top cover (2) into the corresponding load-bearing groove (11) of the engine housing (1), thereby preventing the load-bearing block (21) of the top cover (2) from rotating in the load-bearing groove (11) of the engine housing (1); the upper end top surface of the positioning block (3) is fixed in the annular groove (13) of the engine housing (1) by means of screws (4), thereby fixing the positioning block (3) to the engine housing (1); the engine housing (1) and the top cover (2) are designed in a graduated load-bearing manner of a flange structure, and the load-bearing block (21) of the top cover (2) is embedded in the load-bearing groove (11) of the housing (1), thereby reducing the flange structure and achieving a lightweight structure;

[0024] The positioning block (3) is made of forged metal, such as 30CrMnSiA or D406A;

[0025] The left side surface of the load-bearing block (21) is a butt joint surface (22) between the top cover (2) and the engine housing (1), and the right side surface of the load-bearing block (21) is a butt joint surface (23) between the top cover (2) and the positioning block (3);

[0026] like Figure 4 As shown, the left side surface of the positioning block (3) is a docking stop surface (31) for connecting the top cover (2) and the housing (1), and the right side hole of the positioning block (3) is a mounting positioning hole (32) for connecting the engine housing (1) and the positioning block (3) via a screw (4);

[0027] The present invention is designed to utilize a graduated load-bearing structure to reduce mass and achieve rapid installation. A plurality of matching grooves are designed on the engine housing (1), each matching groove comprising a load-bearing groove (11), an opening groove (12) and an annular groove (13). The lower surface of the load-bearing groove (11) is a docking reference surface, and the upper surface is a load-bearing structural surface. During installation and connection, the load-bearing block (21) on the top cover (2) is placed in the corresponding opening groove (12) on the engine housing (1), and then rotated at a certain angle and pushed into the load-bearing groove (11) of the engine housing (1). Figure 5As shown; then the positioning block (3) is placed in the open groove (12) of the engine housing (1), and then the lower end side of the positioning block (3) presses the load-bearing block (21) of the top cover (2) into the corresponding load-bearing groove (11) of the engine housing (1), so that the docking stop surface (31) fixes the top cover (2) and the housing (1) to prevent the load-bearing block (21) of the top cover (2) from rotating in the load-bearing groove (11) of the engine housing (1); the upper end top surface of the positioning block (3) is fixed in the annular groove (13) of the engine housing (1) by means of screws (4), so that the mounting positioning hole (32) can be used to fix the engine housing (1) and the positioning block (3) by means of screws (4), as shown. Figure 6 and Figure 7 As shown. Among them, Figure 7 The installation position of the load-bearing block (21) of the top cover (2) in the load-bearing groove (11) on the engine housing (1) and the connection relationship between the positioning block (3) and the screw (4) and the engine housing (1) are clearly shown;

[0028] The flange structure of the indexing load-bearing method of the present invention is as follows Figure 8 and Fig. 9 As shown, when connecting and installing, it is only necessary to align the engine housing (1) and the top cover (2) and rotate them by an angle of θ3, thereby achieving quick installation;

[0029] The number N of the matching grooves of the indexing load-bearing method of the present invention is related to the radius R of the docking flange:

[0030] N = ▏k*(πRP) / σ ▏, k is a dimensionless constant with a value of 1.7 ~ 4.6; ………………………(1)

[0031] Where P is the engine operating pressure, σ is the allowable stress of the material;

[0032] The matching groove angle θ1 is related to the number of matching grooves N:

[0033] θ1= ▏360 / N-θ0▏, θ0 is 4°~15°; …………………………………………(2)

[0034] The definitions of the angles are as follows: θ1 is the angle of the matching groove of the engine housing (1), which is related to the number N of matching grooves and is determined by formula (2); θ2 is the angle of the load-bearing groove on the engine housing (1), which is related to the number N of matching grooves and the matching groove angle θ1; θ3 is the angle of the opening groove on the engine housing (1), which is related to the number N of matching grooves and the matching groove angle θ1;

[0035] In the present invention, the parameter values ​​of the indexed load-bearing method follow the principle of minimum structural stress of the engine casing, which are: when the inner radius of the matching groove of the engine casing (1) is in the range of 100 mm to 200 mm, the number of matching grooves is 8, and the matching groove angle θ1 is in the range of 30° to 36°, the load-bearing groove angle θ2 is in the range of 14° to 16°, and the opening groove angle θ3 is in the range of 10° to 12°; when the inner radius of the matching groove of the engine casing (1) is in the range of 200 mm to 300 mm, the number of matching grooves is 10, and the matching groove angle θ1 is in the range of 25° to 28°, the load-bearing groove angle θ2 is in the range of 12° to 14°, and the opening groove angle θ3 is in the range of 8° to 10°; when the inner radius of the matching groove of the engine casing (1) is in the range of 300 mm to 400 mm, the number of matching grooves is 12, and the matching groove angle θ1 is in the range of 20° to 24°, the load-bearing groove angle θ2 is in the range of 10° to 12°, and the range of the opening groove angle θ3 is 6°~8°; when the inner radius of the matching groove of the engine housing (1) is in the range of 400mm~500mm, the number of matching grooves is 16, and the range of the matching groove angle θ1 is 15°~18°, the range of the bearing groove angle θ2 is 7°~9°, and the range of the opening groove angle θ3 is 5°~7°; when the inner radius of the matching groove of the engine housing (1) is in the range of 500mm~600mm, the number of matching grooves is 18, and the range of the matching groove angle θ1 is 12°~16°, the range of the bearing groove angle θ2 is 6°~8°, and the range of the opening groove angle θ3 is 4°~6°; the specific structural parameters are shown in Table 1;

[0036] Table 1 Connection structure parameters of graduated load-bearing method

[0037] project Butt radius R (mm) Number of matching slots N <![CDATA[Fitting groove angle θ1 (°)]]> <![CDATA[Load-bearing groove angle θ2 (°)]]> <![CDATA[Opening groove angle θ3 (°)]]> 1 100 ~ 200 8 30°~ 36° 14°~ 16° 10°~ 12° 2 200 ~ 300 10 25°~ 28° 12°~ 14° 8°~ 10° 3 300 ~ 400 12 20°~ 24° 10°~ 12° 6°~ 8° 4 400 ~ 500 16 15°~ 18° 7°~ 9° 5°~ 7° 5 500 ~ 600 18 12°~ 16° 6°~ 8° 4°~ 6°

[0038] In this embodiment, the engine operating pressure is 6.0 MPa, the allowable stress of the material is 1080 MPa, the inner radius R of the matching groove of the engine housing (1) is 192 mm, the number N of matching grooves is 8, the initial angle θ0 of the load-bearing structure is 11°, the matching groove angle θ1 is 34°, the load-bearing groove angle θ2 is 16°, and the opening groove angle θ3 is 12°. Figure 8 and Fig. 9 As shown;

[0039] like Figure 3 As shown, in this embodiment, eight corresponding bearing blocks (21) are designed and processed on the top cover (2), and the left surface of the bearing block (21) is the top cover docking surface (22). When installing and connecting, the bearing block (21) on the top cover (2) is placed in the opening groove (12) on the engine housing (1), and then rotated 16° (θ2) to be in place;

[0040] Compared with the flange connection structure, the present invention has a compact structure and light weight, and is more than 10% lighter than the flange connection structure under the same conditions; compared with the threaded connection structure, the present invention is quick and convenient to install and connect;

[0041] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in this field.

Claims

1. A lightweight quick-installation connection structure for an engine, characterized in that: The invention comprises an engine housing (1), a top cover (2), a positioning block (3) and a screw (4), wherein the engine housing (1) is evenly provided with matching grooves along the circumference, each matching groove being divided into a load-bearing groove (11), an opening groove (12) and an annular groove (13) in sequence along the circumference, and the top cover (2) is provided with a load-bearing block (21) of the same number as the load-bearing groove (11) of the engine housing (1), the bottom of the load-bearing groove (11) of the engine housing (1) and the bottom of the load-bearing block (21) of the top cover (2) being a docking reference surface, the positioning block (3) being a "Z"-shaped structural member, installed in the opening groove (12) of the engine housing (1), wherein the positioning block The lower end side surface of the positioning block (3) presses the load-bearing block (21) of the top cover (2) into the corresponding load-bearing groove (11) of the engine housing (1), thereby preventing the load-bearing block (21) of the top cover (2) from rotating in the load-bearing groove (11) of the engine housing (1); the upper end top surface of the positioning block (3) is fixed in the annular groove (13) of the engine housing (1) by means of screws (4), thereby fixing the positioning block (3) to the engine housing (1); the engine housing (1) and the top cover (2) are designed in a graduated load-bearing manner of a flange structure, and the load-bearing block (21) of the top cover (2) is embedded in the load-bearing groove (11) of the housing (1), thereby reducing the flange structure and achieving a lightweight structure.

2. The engine lightweight quick installation connection structure according to claim 1, characterized in that: The indexed load-bearing method includes determining the number and angle of the matching grooves of the engine housing (1), which are respectively: the number of matching grooves N = ▏k*(πRP) / σ ▏, wherein ▏ ▏ is a rounding symbol, k is a dimensionless coefficient, which is determined based on the material and working pressure of the engine housing (1) and has a value range of 1.7 to 4.6, P is the engine working pressure, σ is the allowable stress of the material, and R is the inner radius of the matching groove of the engine housing (1); the matching groove angle θ1 = ▏360 / N-θ0▏, wherein θ0 is an initial angle, which is determined based on the material and working pressure of the engine housing (1) and has a value range of 4° to 15°.

3. The engine lightweight quick installation connection structure according to claim 1, characterized in that: The positioning block (3) is made of forged metal, which is 30CrMnSiA or D406A.

4. The engine lightweight quick installation connection structure according to claim 1, characterized in that: The left side surface of the load-bearing block (21) is a butt joint surface (22) between the top cover (2) and the engine housing (1), and the right side surface of the load-bearing block (21) is a butt joint surface (23) between the top cover (2) and the positioning block (3).

5. The engine lightweight quick installation connection structure according to claim 1, characterized in that: The left side surface of the positioning block (3) is a docking stop surface (31) for connecting the top cover (2) and the housing (1), and the right side hole of the positioning block (3) is a mounting positioning hole (32) for connecting the engine housing (1) and the positioning block (3) via screws (4).

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