Inclined liquid rocket engine thrust frame with composite constraint structure

Abstract

The invention discloses an inclined liquid rocket engine thrust frame with a composite constraint structure, and solves the problems that the existing inclined thrust frame only adopts a flexible spring plate supporting structure as a constraint limiting mode, or only adopts a radial deformation adjustable constraint device to reinforce the middle section of a movable frame to resist the radial deformation of the middle section of the movable frame, so that the thrust frame is difficult to deform. The stability of a movable frame and a thrust axis cannot be ensured when a large-thrust engine is tested, and the thrust measurement precision is influenced; comprising a fixed frame and a movable frame, the fixed frame is obliquely installed and fully surrounds a frame structure, the movable frame is of a two-section frustum structure, the movable frame is installed in the fixed frame through a composite restraining structure, and the composite restraining structure comprises a front-section restraining device, a middle-section restraining device and a rear-section restraining device; the front section restraint device comprises a limiting rod, a front restraint limiting roller and a front spring plate; the middle section restraining and limiting device comprises a flexible connection supporting assembly and a belleville spring supporting assembly; and the rear section restraint device comprises a rear restraint limiting roller and a rear spring plate.

Description

Technical Field

[0001] The invention relates to a thrust frame for engine testing, in particular to an inclined liquid rocket engine thrust frame with a composite constraint structure. Background Art

[0002] The thrust frame is the main load-bearing equipment during the test of liquid rocket engines. Among them, an inclined thrust frame is commonly used, which is mainly composed of a fixed frame and a dynamic frame. The dynamic frame is the main force transmission structure. There is an angle between the gravity direction of the dynamic frame and the axial direction of the engine thrust. The dynamic frame structure needs to be supported and constrained to ensure the stability of the structure; when the engine is installed, the support and constraint fulcrum relative to the dynamic frame is a cantilever structure, which will produce a bending moment; at the same time, the liquid rocket engine test has a large vibration. Affected by the assembly accuracy, the thrust will have some lateral forces (non-thrust axis direction), including radial, tangential, etc., and the direction is uncertain; the above gravity, bending moment and lateral force all need to be borne by the constraint structure between the fixed frame and the dynamic frame. In addition, there are differences in the load characteristics of the large end, middle section and small end of the dynamic frame: the large end is close to the test liquid rocket engine, the vibration degree is the largest, the lateral load is large, and the axial displacement is the largest; the middle section load mainly comes from the load deformation and displacement of the dynamic frame itself, which is closest to the center of gravity of the dynamic frame structure; the small end contacts the force sensor, and it is necessary to ensure that the contact position is accurate and stable, the bending moment of gravity is the largest, and the axial deformation is the smallest. The movable frame transfers the thrust load to the force sensor. Due to the deformation of the force sensor itself, the movable frame as a whole will have a displacement of 0.2 to 1.0 mm in the direction of the force sensor. The movable frame is generally a two-section cone structure welded by plate and tube. Under the action of the thrust load, the structure will produce elastic deformation in the direction of the thrust axis, and the deformation is generally 2 to 3 mm. The middle section will be compressed and "expanded", producing elastic deformation in the radial direction, and the deformation is generally 0.5 to 1 mm. It can be seen that the constraint structure of the inclined thrust frame must not only overcome gravity, lateral force, and bending moment, but also have elastic compensation capabilities. In order to ensure the accuracy of thrust measurement, the stiffness of the constraint structure in the thrust axial direction needs to be as small as possible to make the thrust transmission efficiency as high as possible.

[0003] In the prior art, some thrust frames only use a flexible spring plate support structure to limit the position. The spring plate structure will have a huge risk of structural failure under the torque of a large-mass engine and an adapter frame, resulting in a huge risk of the dynamic frame being detached. Chinese patent CN118049331A discloses a radially deformable adjustable constraint device and a thrust frame for liquid rocket engine testing. The thrust frame uses a radially deformable adjustable constraint device in the middle section of the dynamic frame to reinforce the middle section of the dynamic frame and resist radial deformation of the middle section of the dynamic frame. However, it is difficult to ensure the stability of the dynamic frame and the engine thrust axis as a whole, thereby affecting the measurement accuracy of the thrust. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems that the current inclined thrust frame only uses a flexible spring plate support structure as a constraint and limit method, which may cause structural failure under the torque of a large-mass engine and an adapter frame, thereby causing a huge risk of the dynamic frame detaching, or only adds a radial deformation adjustable constraint device to reinforce the middle section of the dynamic frame to resist radial deformation of the middle section of the dynamic frame, and cannot ensure the stability of the dynamic frame and the thrust axis when testing a larger thrust engine, thereby affecting the thrust measurement accuracy. A tilted liquid rocket engine thrust frame with a composite constraint structure is provided.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A tilted liquid rocket engine thrust frame with a composite constraint structure, comprising a fixed frame of a tilted fully enclosed frame structure, and a movable frame of a two-stage frustum structure, wherein the movable frame is installed inside the fixed frame through a constraint structure; the special feature of the invention is that the constraint structure is a composite constraint structure, comprising a front-stage constraint device, a middle-stage constraint device, and a rear-stage constraint device;

[0007] The front section restraining device is installed between the fixed frame and the large end of the movable frame, and includes a limit rod, a front restraining limit roller and a front spring plate; there are 4 limit rods, one end of which is fixedly installed at the four corners of the fixed frame, and the other end passes through the corner of the movable frame, and is provided with a stopper to prevent the movable frame from slipping; there are 4 front restraining limit rollers, which are respectively installed on the inner sides of the four corners of the fixed frame through roller brackets, and their side walls are respectively in contact with the four corners of the movable frame; there are 4 groups of front spring plates, each group has 2, which are respectively installed between the front end of the fixed frame and the large end of the movable frame;

[0008] The middle section restraining and limiting device is installed between the fixed frame and the middle section of the movable frame, and includes a flexible connection support assembly and a disc spring support assembly; there are two flexible connection support assemblies, which are installed on the inner side wall of the lower part of the fixed frame, and the upper end thereof is in contact with the outer side surface of the lower part of the middle section of the movable frame; there are two disc spring support assemblies, which are installed on the inner side wall of the upper part of the fixed frame, and the lower end thereof is in contact with the outer side surface of the upper part of the middle section of the movable frame; the installation positions of the flexible connection support assembly and the disc spring support assembly correspond to each other up and down;

[0009] The rear section constraint device is installed between the fixed frame and the small end of the movable frame, and includes a rear constraint limit roller and a rear spring plate; there are 3 rear constraint limit rollers on the left and right, and the 3 rear constraint limit rollers on the left and right are installed in a U-shaped distributed manner on the fixed frame through roller brackets, and are in contact with the outer side wall of the movable frame extending between the 3 rollers; there are 4 groups of rear spring plates, each group has 2, which are respectively installed between the rear end of the fixed frame and the small end of the movable frame.

[0010] Furthermore, the front spring plate is a rectangular variable cross-section structure, the ratio of length to width is 3 to 5, and the width is 150 to 250 mm; the cross-section change sequence of the front spring plate is thick-thin-thick-thin-thick, and the thickness-thin ratio is 2:1. In order to ensure sufficient structural strength and small stiffness of the front spring plate, the thickness of the thin part is generally 5 to 10 mm; the method for determining the thickness of the thin part is: ((radial force)×1.5 / (radial cross-sectional area)×2.5)<allowable stress of the material, and the axial and radial stiffness ratio is generally less than 1:500; the length ratio of each part of the front spring plate is 1:1:2:1:1, which ensures that the movable frame is stably installed while having a certain flexibility in the thrust transmission axial direction; the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends, and the thin parts are elastic deformation areas that can provide elastic compensation in the thrust axis direction.

[0011] Furthermore, the rear spring plate is a rectangular variable cross-section structure, the ratio of length to width is 3 to 5, and the width is 150 to 250 mm; the cross-section change sequence of the rear spring plate is thick-thin-thick-thin-thick, the thickness ratio is 2:1, and the thickness of the thin part is 5 to 10 mm; the length ratio of each part of the rear spring plate is 1:1:5:1:1, and the axial and radial stiffness ratio is less than 1:500, which ensures that the movable frame is stably installed while having a certain flexibility in the thrust transmission axial direction; the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends, and the thin parts are elastic deformation areas that can provide elastic compensation in the thrust axis direction.

[0012] Furthermore, each of the limit rods includes a fixed seat, a transverse adjustment screw rod, and a stopper; a through bolt hole is provided on one side of the fixed seat and at a corresponding position on the fixed frame, and the fixed seat is installed on the fixed frame by a fixing bolt; one end of the transverse adjustment screw rod passes through the fixed frame and is threadedly connected to the fixed seat, and the other end passes through a first through hole correspondingly provided on the movable frame and is slidably connected to the first through hole, and the end is provided with the stopper, and the diameter of the stopper is larger than the diameter of the end of the transverse adjustment screw rod; the distance between the stopper and the first through hole is 2 to 3 mm, and the distance between the stopper and the first through hole can be adjusted by rotating the transverse adjustment screw rod;

[0013] The angle between the axis of each front constraint limit roller and the two frame beams of the corresponding fixed frame is 45°; each group of two front spring plates are respectively installed on both sides of the four front constraint limit rollers, are perpendicular to the two frame beams of the corresponding fixed frame, and are symmetrically arranged about the diagonal of the corresponding fixed frame; the front constraint limit roller is a bearing type roller, and a height adjustment structure is provided on its roller bracket, and the positioning height of the roller can be adjusted by a screw rod, thereby adjusting the position of the moving frame in the fixed frame.

[0014] Furthermore, the rear constraint limit roller is a bearing type roller, and a height adjustment structure is provided on its roller bracket, and the positioning height of the roller can be adjusted by a screw rod, thereby adjusting the position of the movable frame in the fixed frame; each group of two rear spring plates are respectively installed between the outer side surfaces of the four frame beams of the fixed frame and the end surface of the small end of the movable frame; the installation position of the rear spring plates meets the following conditions: the spacing between the two rear spring plates in the transverse direction is greater than the spacing between the two rear spring plates in the longitudinal direction, and each group of two rear spring plates are parallel to each other and perpendicular to the frame beams of the fixed frame where they are installed.

[0015] Furthermore, the flexible connection support assembly includes an adjustable support seat and a flexible support member, the flexible support member is a structure with a thin middle and thick ends, one end of which is mounted on the adjustable support seat, and the other end is provided with a first connection seat, and the first connection seat is provided with a first roller;

[0016] The adjustable support seat includes a first adjustment support seat connected to one end of the flexible support member, a first support seat placed below the first adjustment support seat, a first anti-loosening nut fixedly connected to the inner side wall of the bottom of the first adjustment support seat, and a first adjustment screw rod; the screw end of the first adjustment screw rod passes through the first support seat and extends into the interior of the first adjustment support seat, and is threadedly connected to the first anti-loosening nut, and the first adjustment screw rod and the first support seat are rotatably connected; a first guide plate is provided on one side of the lower end of the first adjustment support seat, and the inner side wall of the first guide plate is in contact with the side wall of the first support seat;

[0017] The length of the middle thin section of the flexible support is smaller than the length of the thick sections at both ends, and the ratio of the diameter of the middle thin section of the flexible support to the diameter of the thick sections at both ends is smaller than 1 / 3;

[0018] The first support seat is installed on the inner wall of the lower part of the fixed frame; by rotating the first adjusting screw rod, the first anti-loosening nut threadedly connected thereto drives the first adjusting support seat to rise and fall under the guidance of the first guide plate, so as to adjust the first roller to fit the outer side surface of the lower middle section of the moving frame; the first roller ensures that when the flexible connection support assembly fits the lower middle section of the moving frame, the friction force in the thrust axis direction is small, and the flexible support is made of spring steel, which can support a certain lateral deformation.

[0019] Furthermore, the disc spring support assembly includes a second support seat installed on the inner side wall of the upper part of the fixed frame, a second adjusting support placed below the second support seat, a second connecting seat slidably connected to the second adjusting support, a second adjusting screw and a second anti-loosening nut; the second adjusting support is provided with a second through hole, a boss is provided on the inner wall of the second through hole, the nut end of the second adjusting screw extends into the second through hole and abuts against the boss, the screw end extends into the second support seat and is threadedly connected to the second anti-loosening nut, and the second anti-loosening nut is rotatably connected to the inner side wall of the bottom of the second support seat; a limiting plate is sleeved on the second adjusting screw, and the limiting plate is fixedly connected to the upper surface of the second adjusting support;

[0020] The small end of the second connecting seat extends into the second through hole and is slidably connected to the second adjusting support. At least two disc springs are sleeved on both sides of the small end between the second adjusting support and the large end of the second connecting seat. A second roller is provided at the large end of the second connecting seat.

[0021] An opening is provided on one side of the second supporting seat, and a second guide plate is provided below the opening, and the inner side wall of the second guide plate is fitted with the side wall of the second adjusting support; by rotating the second anti-loosening nut, it is made to rotate on the inner side wall of the bottom of the second supporting seat, and the second adjusting screw rod threadedly connected thereto drives the second adjusting support to rise and fall under the guidance of the second guide plate to adjust the second roller to fit with the outer side surface above the middle section of the moving frame; the second roller ensures that when the disc spring supporting assembly fits with the upper part of the middle section of the moving frame, the friction force in the thrust axis direction is small, and the disc spring can withstand a certain upper and lower lateral force.

[0022] Beneficial effects of the present invention:

[0023] 1. The present invention provides an inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the front spring plate and the rear spring plate are both of rectangular variable cross-section design, and the axial and radial stiffness ratio is less than 1:500, which ensures that the radial direction can stably withstand the lateral force while the smaller axial stiffness can also ensure the efficient transmission of thrust.

[0024] 2. The present invention provides an inclined liquid rocket engine thrust frame with a composite constraint structure. The front constraint limit roller, the rear constraint limit roller and the middle section constraint limit device jointly assist in supporting the gravity of the dynamic frame and overcoming the lateral force. The front constraint limit roller, the rear constraint limit roller and the roller structure in the middle section constraint limit device reduce the friction force on the dynamic frame, thereby ensuring efficient and accurate transmission of thrust.

[0025] 3. The present invention provides an inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the front constraint limit roller is at a 45° angle to the front spring plate, mainly assisting in bearing the lateral force in the non-orthogonal direction when the front spring plate is orthogonally installed, thereby improving the stability of the front spring plate.

[0026] 4. The present invention provides an inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the rear constraint limit roller and the front constraint limit roller are distributed at an angle of 45° in space, thereby increasing the stress points of the entire movable frame and improving the stability of the movable frame.

[0027] 5. The present invention provides an inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the flexible connection support assembly and the disc spring support assembly are installed correspondingly up and down, which can elastically compensate for the radial deformation caused by the "expansion" of the middle section of the dynamic frame due to the force, thereby increasing the stability of the dynamic frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of an embodiment of a tilted liquid rocket engine thrust frame with a composite constraint structure of the present invention;

[0029] Figure 2 It is a schematic structural diagram of the front section restraint device in an embodiment of the present invention;

[0030] Figure 3 It is a schematic structural diagram of a middle section restraining device in an embodiment of the present invention;

[0031] Figure 4 2 is a schematic diagram of the structure of the rear section restraint device in an embodiment of the present invention;

[0032] Figure 5 Schematic diagram of the structure of the front spring plate and the rear spring plate in an embodiment of the present invention, wherein (a) is the front spring plate and (b) is the rear spring plate;

[0033] Figure 6 is an enlarged view of the connection portion of the limit rod in the front section restraint device of the embodiment of the present invention;

[0034] Figure 7 is a schematic structural diagram of a flexible connection support assembly in an embodiment of the present invention;

[0035] Figure 8 Schematic diagram of the structure of the disc spring support assembly in an embodiment of the present invention.

[0036] Figure Number:

[0037] 1-front section restraint device, 11-limit rod, 111-fixed seat, 112-lateral adjustment screw, 113-stop head, 114-fixing bolt, 12-front restraint limit roller, 13-front spring plate, 2-middle section restraint device, 21-flexible connection support assembly, 211-adjustable support seat, 2111-first adjustment support, 2112-first support seat, 2113-first anti-loosening nut, 2114-and first adjustment screw, 2115-first guide plate, 212-flexible support, 213-first connection Seat, 214-first roller, 22-disc spring supporting assembly, 221-second supporting seat, 2211-second guide plate, 222-second adjusting support, 2221-second through hole, 2222-boss, 223-second connecting seat, 224-second adjusting screw, 225-and second anti-loosening nut, 226-limiting plate, 227-disc spring, 228-second roller, 3-rear section restraining device, 31-rear restraining limiting roller, 32-rear spring plate, 4-fixed frame, 5-moving frame, 51-first through hole. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] An embodiment of the present invention provides a tilted liquid rocket engine thrust frame with a composite constraint structure, such as Figure 1 As shown, it includes a fixed frame 4 with an inclined installed full-enclosed frame structure, and a movable frame 5 with a two-stage frustum structure. The movable frame 5 is installed inside the fixed frame 4 through a composite constraint structure; the composite constraint structure includes a front section constraint device 1, a middle section constraint device 2, and a rear section constraint device 3.

[0040] like Figure 2 As shown, the front section restraint device 1 is installed between the fixed frame 4 and the large end of the movable frame 5, and includes a limit rod 11, a front restraint limit roller 12 and a front spring plate 13;

[0041] There are 4 limit rods 11, one end of which is fixedly mounted on the four corners of the fixed frame 4, and the other end passes through the corner of the movable frame 5 and is provided with a stopper 113; Figure 6 Each limit rod 11 includes a fixed seat 111, a transverse adjustment screw rod 112, and a stopper 113; a through bolt hole is provided on one side of the fixed seat 111 and at a corresponding position on the fixed frame 4, and the fixed seat 111 is installed on the fixed frame 4 by a fixing bolt 114; one end of the transverse adjustment screw rod 112 passes through the fixed frame 4 and is threadedly connected to the fixed seat 111, and the other end passes through the first through hole 51 correspondingly provided on the movable frame 5, and is slidably connected to the first through hole 51, and a stopper 113 is provided at the end, and the diameter of the stopper 113 is greater than the diameter of the end of the transverse adjustment screw rod 112; the distance between the stopper 113 and the first through hole 51 can be adjusted by rotating the transverse adjustment screw rod 112, and the distance is 2 to 3 mm; the stopper 113 can prevent the movable frame 5 from slipping, the transverse adjustment screw rod 112 is slidably connected to the first through hole 51, and the distance between the stopper 113 and the first through hole 51 is 2 to 3 mm, which can meet the displacement and deformation requirements of the movable frame in the thrust axis when conducting an engine thrust test.

[0042] There are four front constraint limit rollers 12, which are respectively installed on the inner sides of the four corners of the fixed frame 4 through roller brackets, and their side walls are in contact with the four corners of the movable frame 5 respectively; the angle between the axis of each front constraint limit roller 12 and the two frame beams of the corresponding fixed frame 4 is 45°; each group of two front spring plates 13 is respectively installed on both sides of the four front constraint limit rollers 12, and is perpendicular to the two frame beams of the corresponding fixed frame 4, and is symmetrically arranged about the diagonal of the corresponding fixed frame 4; the front constraint limit roller 12 is a bearing type roller, and its roller bracket is provided with a height adjustment structure, and the positioning height of the roller can be adjusted by a screw, thereby adjusting the position of the movable frame 5 in the fixed frame 4.

[0043] like Figure 3 As shown, the middle section restraining and limiting device 2 is installed between the fixed frame 4 and the middle section of the moving frame 5, and includes a flexible connection support assembly 21 and a disc spring support assembly 22;

[0044] Reference Figure 7 The flexible connection support assembly 21 includes an adjustable support seat 211 and a flexible support member 212. The length of the middle thin section of the flexible support member 212 is less than the length of the thick sections at both ends, and the ratio of the diameter of the middle thin section to the diameter of the thick sections at both ends is less than 1 / 3; one end of the flexible support member 212 is installed on the adjustable support seat 211, and the other end is provided with a first connection seat 213, and the first connection seat 213 is provided with a first roller 214;

[0045] The adjustable support seat 211 includes a first adjustment support seat 2111 connected to one end of the flexible support member 212, a first support seat 2112 placed below the first adjustment support seat 2111, a first anti-loosening nut 2113 fixedly connected to the inner side wall of the bottom of the first adjustment support seat 2111, and a first adjustment screw rod 2114; the screw end of the first adjustment screw rod 2114 passes through the first support seat 2112 and extends into the interior of the first adjustment support seat 2111, and is threadedly connected to the first anti-loosening nut 2113, and the first adjustment screw rod 2114 is rotatably connected to the first support seat 2112; a first guide plate 2115 is provided at one side of the lower end of the first adjustment support seat 2111, and the inner side wall of the first guide plate 2115 is in contact with the side wall of the first support seat 2112;

[0046] The first support seat 2112 is installed on the inner wall of the lower part of the fixed frame 4; by rotating the first adjusting screw rod 2114, the first anti-loosening nut 2113 threadedly connected thereto drives the first adjusting support seat 2111 to rise and fall under the guidance of the first guide plate 2115, so as to adjust the first roller 214 to fit with the outer side surface of the lower middle section of the moving frame 5; the first roller 214 ensures that when the flexible connection support assembly 21 fits with the lower middle section of the moving frame 5, the friction force in the thrust axis direction is small, and the flexible support member 212 is made of spring steel, which can support a certain lateral deformation.

[0047] Reference Figure 8 The disc spring support assembly 22 includes a second support seat 221 installed on the inner side wall of the upper part of the fixed frame 4, a second adjusting support 222 placed below the second support seat 221, a second connecting seat 223 slidably connected to the second adjusting support 222, a second adjusting screw rod 224 and a second anti-loosening nut 225; a second through hole 2221 is opened on the second adjusting support 222, a boss 2222 is arranged on the inner wall of the second through hole 2221, a nut end of the second adjusting screw rod 224 extends into the second through hole 2221 and abuts against the boss 2222, and the screw end extends into the second support seat 221 and is threadedly connected with the second anti-loosening nut 225, and the second anti-loosening nut 225 is rotatably connected to the inner side wall of the bottom of the second support seat 221; a limiting plate 226 is sleeved on the second adjusting screw rod 224, and the limiting plate 226 is fixedly connected to the upper surface of the second adjusting support 222;

[0048] The small end of the second connecting seat 223 extends into the second through hole 2221 and is slidably connected to the second adjusting support 222. At least two disc springs 227 are sleeved on both sides of the small end between the second adjusting support 222 and the large end of the second connecting seat 223. A second roller 228 is provided at the large end of the second connecting seat 223.

[0049] An opening is provided on one side of the second supporting seat 221, and a second guide plate 2211 is provided below the opening. The inner side wall of the second guide plate 2211 fits with the side wall of the second adjusting support 222; by rotating the second anti-loosening nut 225, it is made to rotate on the inner side wall of the bottom of the second supporting seat 221, and the second adjusting screw rod 224 threadedly connected thereto drives the second adjusting support 222 to rise and fall under the guidance of the second guide plate 2211, so as to adjust the second roller 228 to fit with the outer side surface above the middle section of the moving frame 5; the second roller 228 ensures that when the disc spring supporting assembly 22 fits with the upper middle section of the moving frame 5, the friction force in the thrust axis direction is small, and the disc spring 227 can withstand a certain upper and lower lateral force.

[0050] The installation positions of the flexible connection support assembly 21 and the disc spring support assembly 22 correspond to each other up and down.

[0051] like Figure 4 As shown, the rear section restraint device 3 is installed between the fixed frame 4 and the small end of the movable frame 5, and includes a rear restraint limit roller 31 and a rear spring plate 32;

[0052] There are three rear constraint limit rollers 31 on the left and right, and the three rear constraint limit rollers 31 on the left and right are distributedly installed on the fixed frame 4 in a U shape through roller brackets, and are in contact with the outer side wall of the movable frame 5 extending between the three rollers; the rear constraint limit roller 31 is a bearing type roller, and its roller bracket is provided with a height adjustment structure, and the positioning height of the roller can be adjusted by a screw rod, thereby adjusting the position of the movable frame 5 in the fixed frame 4; there are four groups of rear spring plates 32, each group has two, and each group of two rear spring plates 32 is respectively installed between the outer side surfaces of the four frame beams of the fixed frame 4 and the small end surface of the movable frame 5; the installation position of the rear spring plates 32 meets the following conditions: the spacing between the two rear spring plates 32 in the transverse direction is greater than the spacing between the two rear spring plates 32 in the longitudinal direction, and each group of two rear spring plates 32 is parallel to each other and perpendicular to the frame beam of the fixed frame 4 where they are installed.

[0053] like Figure 5 As shown, the front spring plate 13 is a rectangular variable cross-section structure, the ratio of length to width is 5, and the width is 200mm; the cross-section change sequence of the front spring plate 13 is thick-thin-thick-thin-thick, the thickness ratio is 2:1, and the thickness of the thin part is 8mm; the length ratio of each part of the front spring plate 13 is 1:1:2:1:1, and the axial and radial stiffness ratio is less than 1:500, which ensures that the movable frame 5 is installed stably while having a certain flexibility in the thrust transmission axial direction; the thick parts at both ends of the front spring plate 13 are connected to the fixed frame and the movable frame as connecting ends, and the thin parts are used as elastic deformation areas to provide elastic compensation in the thrust axis direction;

[0054] The rear spring plate 32 is a rectangular variable cross-section structure, and the order of cross-section change is thick-thin-thick-thin-thick. Except that the length of the middle thick part is different from that of the front spring plate 13, the other parameters are consistent with the front spring plate 13. The length ratio of each part of the rear spring plate 32 is 1:1:5:1:1; because the large end of the moving frame 5 is closer to the test liquid rocket engine, the vibration and axial deformation are greater, so the front spring plate 13 is selected to be short to ensure its axial stability; the small end of the moving frame 5 is far away from the engine and the axial deformation is small, so the rear spring plate 32 is selected to be long to ensure low axial stiffness and improve the thrust transfer ratio.

[0055] In summary, the present embodiment provides a tilted liquid rocket engine thrust frame with a composite constraint structure, and its composite constraint structure can withstand the gravity of the dynamic frame 5 in the thrust frame, so that the force transmission path of the dynamic frame 5 is guaranteed to be on the thrust axis. At the same time, it can also withstand the bending moment generated by the engine and the lateral force caused by vibration and other reasons during the engine test, thereby ensuring the stability of the thrust frame and the thrust axis, thereby realizing accurate transmission and measurement of thrust.

Claims

1. A tilted liquid rocket engine thrust frame with a composite constraint structure, comprising a tilted fixed frame (4) with a fully enclosed frame structure, and a moving frame (5) with a two-stage frustum structure, wherein the moving frame (5) is installed inside the fixed frame (4) through a constraint structure; characterized in that: The restraint structure is a composite restraint structure, comprising a front restraint device (1), a middle restraint device (2), and a rear restraint device (3); The front section restraining device (1) is installed between the fixed frame (4) and the large end of the movable frame (5), and comprises a limit rod (11), a front restraining limit roller (12) and a front spring plate (13); the limit rod (11) is 4 in number, one end of which is fixedly installed at the four corners of the fixed frame (4), and the other end passes through the corner of the movable frame (5), and is provided with a stopper to prevent the movable frame (5) from slipping off; the front restraining limit roller (12) is 4 in number, which is installed at the inner side of the four corners of the fixed frame (4) through the roller bracket, and the side walls thereof are in contact with the four corners of the movable frame (5); the front spring plate (13) has 4 groups, each group has 2, and is installed between the front end of the fixed frame (4) and the large end of the movable frame (5); The middle section restraining and limiting device (2) is installed between the fixed frame (4) and the middle section of the movable frame (5), and comprises a flexible connection support assembly (21) and a disc spring support assembly (22); the number of the flexible connection support assembly (21) is two, which are installed on the inner side wall of the lower part of the fixed frame (4), and the upper end thereof is in contact with the lower outer side surface of the middle section of the movable frame (5); the number of the disc spring support assembly (22) is two, which are installed on the inner side wall of the upper part of the fixed frame (4), and the lower end thereof is in contact with the upper outer side surface of the middle section of the movable frame (5); the installation positions of the flexible connection support assembly (21) and the disc spring support assembly (22) correspond to each other up and down; The rear section restraining device (3) is installed between the fixed frame (4) and the small end of the movable frame (5), and comprises a rear restraining limit roller (31) and a rear spring plate (32); there are three rear restraining limit rollers (31) on the left and right sides, and the three rear restraining limit rollers (31) on the left and right sides are installed on the fixed frame (4) in a U-shaped distributed manner through roller brackets, and are in contact with the outer side wall of the movable frame (5) extending between the three rollers; there are four groups of rear spring plates (32), each group has two, and they are respectively installed between the rear end of the fixed frame (4) and the small end of the movable frame (5).

2. The tilted liquid rocket engine thrust frame with a composite constraint structure according to claim 1, characterized in that: The front spring plate (13) is a rectangular variable cross-section structure, the ratio of length to width is 3-5, and the width is 150-250 mm; the cross-section change sequence of the front spring plate (13) is thick-thin-thick-thin-thick, the thickness ratio is 2:1, and the thickness of the thin part is 5-10 mm; the length ratio of each part of the front spring plate (13) is 1:1:2:1:1, and the axial and radial stiffness ratio is less than 1:500, ensuring that the movable frame (5) is stably installed while having a certain flexibility in the thrust transmission axial direction; the thick parts at both ends are respectively connected to the fixed frame and the movable frame as connecting ends, and the thin parts are used as elastic deformation areas to provide elastic compensation in the thrust axis direction.

3. The tilted liquid rocket engine thrust frame with a composite constraint structure according to claim 1 or 2, characterized in that: The rear spring plate (32) is a rectangular variable cross-section structure, the ratio of length to width is 3-5, and the width is 150-250 mm; the cross-section change sequence of the rear spring plate (32) is thick-thin-thick-thin-thick, the thickness ratio is 2:1, and the thickness of the thin part is 5-10 mm; the length ratio of each part of the rear spring plate (32) is 1:1:5:1:1, and the axial and radial stiffness ratio is less than 1:500, ensuring that the movable frame (5) is installed stably while having a certain flexibility in the thrust transmission axial direction; the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends respectively, and the thin parts are used as elastic deformation areas to provide elastic compensation in the thrust axis direction.

4. The tilted liquid rocket engine thrust frame with a composite constraint structure according to claim 1, characterized in that: Each of the limit rods (11) comprises a fixed seat (111), a transverse adjustment screw rod (112), and a stopper (113); a through bolt hole is provided on one side of the fixed seat (111) and at a corresponding position on the fixed frame (4); the fixed seat (111) is mounted on the fixed frame (4) via a fixing bolt (114); one end of the transverse adjustment screw rod (112) passes through the fixed frame (4) and is threadedly connected to the fixed seat (111); the other end passes through a first through hole (51) correspondingly provided on the movable frame (5) and is slidably connected to the first through hole (51); the end thereof is provided with the stopper (113); the diameter of the stopper (113) is larger than the diameter of the end of the transverse adjustment screw rod (112); the distance between the stopper (113) and the first through hole (51) is 2 to 3 mm; the distance between the stopper (113) and the first through hole (51) can be adjusted by rotating the transverse adjustment screw rod (112); The included angle between the axis of each front restraining and limiting roller (12) and the two frame beams of the corresponding fixed frame (4) is 45°; each group of two front spring plates (13) are respectively installed on both sides of the four front restraining and limiting rollers (12), are respectively perpendicular to the two frame beams of the corresponding fixed frame (4), and are symmetrically arranged about the diagonal line of the corresponding fixed frame (4); the front restraining and limiting roller (12) is a bearing-type roller, and a height adjustment structure is provided on its roller bracket, and the positioning height of the roller can be adjusted by a screw rod, thereby adjusting the position of the movable frame (5) in the fixed frame (4).

5. The tilted liquid rocket engine thrust frame with a composite constraint structure according to claim 1, characterized in that: The rear restraining limit roller (31) is a bearing type roller, and a height adjustment structure is provided on the roller bracket thereof, and the positioning height of the roller can be adjusted by a screw rod, thereby adjusting the position of the movable frame (5) in the fixed frame (4); each group of two rear spring plates (32) are respectively installed between the outer side surfaces of the four frame beams of the fixed frame (4) and the small end surface of the movable frame (5); the installation position of the rear spring plates (32) meets the following conditions: the spacing between the two rear spring plates (32) in the transverse direction is greater than the spacing between the two rear spring plates (32) in the longitudinal direction, and each group of two rear spring plates (32) are parallel to each other and perpendicular to the frame beam of the fixed frame (4) where they are installed.

6. The tilted liquid rocket engine thrust frame with a composite constraint structure according to claim 1, characterized in that: The flexible connection support assembly (21) comprises an adjustable support seat (211) and a flexible support member (212); the flexible support member (212) is a structure thin in the middle and thick at both ends, one end of which is mounted on the adjustable support seat (211), and the other end is provided with a first connection seat (213), and the first connection seat (213) is provided with a first roller (214); The adjustable support seat (211) comprises a first adjustment support seat (2111) connected to one end of the flexible support member (212), a first support seat (2112) disposed below the first adjustment support seat (2111), a first anti-loosening nut (2113) fixedly connected to the inner side wall of the bottom of the first adjustment support seat (2111), and a first adjustment screw rod (2114); the screw end of the first adjustment screw rod (2114) passes through the first support seat (2112) and extends into the interior of the first adjustment support seat (2111), and is threadedly connected to the first anti-loosening nut (2113), and the first adjustment screw rod (2114) and the first support seat (2112) are rotatably connected; a first guide plate (2115) is disposed on one side of the lower end of the first adjustment support seat (2111), and the inner side wall of the first guide plate (2115) is in contact with the side wall of the first support seat (2112); The length of the middle thin section of the flexible support (212) is smaller than the length of the thick sections at both ends, and the ratio of the diameter of the middle thin section of the flexible support (212) to the diameter of the thick sections at both ends is smaller than 1 / 3; The first support seat (2112) is mounted on the inner side wall of the lower part of the fixed frame (4); by rotating the first adjustment screw rod (2114), the first anti-loosening nut (2113) threadedly connected thereto drives the first adjustment support seat (2111) to rise and fall under the guidance of the first guide plate (2115), so as to adjust the first roller (214) to fit the outer side surface of the lower middle section of the movable frame (5).

7. The tilted liquid rocket engine thrust frame with a composite constraint structure according to claim 1, characterized in that: The disc spring support assembly (22) comprises a second support seat (221) mounted on the inner side wall of the upper part of the fixed frame (4), a second adjustment support seat (222) disposed below the second support seat (221), a second connecting seat (223) slidably connected to the second adjustment support seat (222), a second adjustment screw rod (224) and a second anti-loosening nut (225); the second adjustment support seat (222) is provided with a second through hole (2221), and a boss (2221) is provided on the inner wall of the second through hole (2221). 2222), the nut end of the second adjusting screw rod (224) extends into the second through hole (2221) and abuts against the boss (2222), the screw end extends into the second support seat (221) and is threadedly connected with the second anti-loosening nut (225), and the second anti-loosening nut (225) is rotatably connected to the inner side wall of the bottom of the second support seat (221); a limiting plate (226) is sleeved on the second adjusting screw rod (224), and the limiting plate (226) is fixedly connected to the upper surface of the second adjusting support seat (222); The small end of the second connecting seat (223) extends into the second through hole (2221) and is slidably connected to the second adjusting support (222); at least two disc springs (227) are sleeved on both sides of the small end and are located between the second adjusting support (222) and the large end of the second connecting seat (223); a second roller (228) is provided at the large end of the second connecting seat (223); One side of the second support seat (221) is provided with an opening, and a second guide plate (2211) is provided below the opening, and the inner side wall of the second guide plate (2211) is in contact with the side wall of the second adjustment support seat (222); by rotating the second anti-loosening nut (225), the second anti-loosening nut (225) is rotated on the inner side wall of the bottom of the second support seat (221), and the second adjustment screw rod (224) threadedly connected thereto drives the second adjustment support seat (222) to rise and fall under the guidance of the second guide plate (2211), so as to adjust the second roller (228) to be in contact with the outer side surface above the middle section of the movable frame (5).

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