A tilting liquid rocket engine thrust frame with composite constraint structure

Abstract

The application discloses a tilting liquid rocket engine thrust frame with a composite constraint structure, and solves the problem that current tilting thrust frames only adopt flexible spring plate support structures as constraint limiting modes, or only increase a kind of radial deformation adjustable constraint device to reinforce the middle section of a movable frame and resist radial deformation of the middle section of the movable frame, so that the stability of the movable frame and a thrust axis cannot be guaranteed when a larger thrust engine is tested, and the precision of thrust measurement is affected; the tilting liquid rocket engine thrust frame comprises a fixed frame with a full-surrounding frame structure and a movable frame with a two-section conical frustum structure, the movable frame is installed in the fixed frame through a composite constraint structure, and the composite constraint structure comprises a front section constraint device, a middle section constraint device and a rear section constraint device; the front section constraint device comprises a limiting rod, a front constraint limiting roller and a front spring plate; the middle section constraint limiting device comprises a flexible connecting support assembly and a disc spring support assembly; and the rear section constraint device comprises a rear constraint limiting roller and a rear spring plate.

Description

TECHNICAL FIELD

[0001] The present application relates to a thrust frame for engine test, in particular to an inclined liquid rocket engine thrust frame with a composite constraint structure. BACKGROUND

[0002] The thrust frame is the main bearing equipment in liquid rocket engine test, and an inclined thrust frame is commonly used, which mainly consists of a fixed frame and a movable frame. The movable frame is the main force transmission structure, and the gravity direction of the movable frame and the axial direction of the engine thrust exist an angle, so the structure of the movable frame needs to be supported and constrained to ensure the stability of the structure; the support and constraint support point of the engine relative to the movable frame is a cantilever structure when the engine is installed, which will produce a bending moment effect; at the same time, the liquid rocket engine test has a large vibration, and due to the influence of assembly accuracy, the thrust will have some lateral forces (non-thrust axis direction), including radial, tangential and other directions, the direction is uncertain; the above gravity, bending moment and lateral force need to be borne by the constraint structure between the fixed frame and the movable frame. In addition, the load characteristics of the large end, middle section and small end of the movable frame also exist differences: the large end is closest 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 is mainly from the deformation and displacement of the movable frame itself, and is closest to the position of the gravity center of the movable frame structure; the small end contacts the force sensor, and needs to ensure the accurate and stable contact position, the bending moment of the gravity is the largest, and the axial deformation is the smallest. The movable frame transmits the thrust load to the force sensor, and due to the deformation of the force sensor itself, the movable frame as a whole will have a displacement of 0.2-1.0mm towards the force sensor. The movable frame is generally a two-section conical structure piece welded by plates and pipes, and under the action of the thrust load, the structure piece will produce elastic deformation in the thrust axis direction, and the deformation amount is generally 2-3mm. In the middle section area, it will be "expanded" by pressure and produce elastic deformation in the radial direction, and the deformation amount is generally 0.5-1mm. As can be seen, the constraint structure of the inclined thrust frame not only needs to overcome the gravity, lateral force and bending moment, but also needs to have elastic compensation capability. In order to ensure the accuracy of the thrust measurement, the stiffness of the constraint structure in the thrust axial direction needs to be as small as possible, so that the thrust transmission efficiency is as high as possible.

[0003] In the prior art, some thrust frames only use the constraint limiting method of flexible spring plate support structure, and the spring plate structure will have a great risk of structural failure under the moment effect of large mass engine and adapter frame, resulting in the separation of the movable frame. Chinese patent CN118049331A discloses a radial deformation adjustable constraint device and a liquid rocket engine test thrust frame, which adopts a radial deformation adjustable constraint device in the middle section of the movable frame to reinforce the middle section of the movable frame, which can resist the radial deformation of the middle section of the movable frame, but it is difficult to ensure the stability of the movable frame and the engine thrust axis as a whole, thereby affecting the measurement accuracy of the thrust. SUMMARY

[0004] The present application aims to solve the technical problems that the current inclined thrust frame only uses flexible spring plate support structure as a constraint limiting method, which will cause structural failure under the torque effect of large mass engine and adapter frame, thus leading to the huge risk of dynamic frame disengagement, or only increases a radial deformation adjustable constraint device to reinforce the middle section of the dynamic frame to resist the radial deformation of the middle section of the dynamic frame, which cannot guarantee the stability of the dynamic frame and the thrust axis when testing large thrust engine, and affects the precision of thrust measurement.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] The present application adopts the following technical solutions:

[0007] The front segment constraint device is installed between the fixed frame and the large end of the dynamic frame, and includes a limiting rod, a front constraint limiting roller and a front spring plate.

[0008] The middle segment constraint limiting device is installed between the fixed frame and the middle segment of the dynamic frame, and includes a flexible connection support assembly and a disc spring support assembly.

[0009] The rear segment constraint device is installed between the fixed frame and the small end of the dynamic frame, and includes a rear constraint limiting roller and a rear spring plate.

[0010] Further, the front spring plate is a rectangular variable cross-section structure, the ratio of length and width is 3-5, and the width is 150-250 mm; the cross-section of the front spring plate changes in the order of thick-thin-thick-thin-thick, the thick-thin ratio is 2:1, and the thin part is generally 5-10 mm thick in order to ensure sufficient structural strength and smaller rigidity of the front spring plate; the thin part is valued by ((radial force received) x 1.5 / (radial cross-sectional area) x 2.5) < material allowable stress, and the axial and radial rigidity 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 stable installation of the movable frame and has a certain flexibility in the axial direction of the thrust transmission; the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends, and the thin part is an elastic deformation area that can provide elastic compensation in the thrust axial direction.

[0011] Further, the rear spring plate is a rectangular variable cross-section structure, the ratio of length and width is 3-5, and the width is 150-250 mm; the cross-section of the rear spring plate changes in the order of thick-thin-thick-thin-thick, the thick-thin ratio is 2:1, and the thin part is 5-10 mm thick; the length ratio of each part of the rear spring plate is 1:1:5:1:1, the axial and radial rigidity ratio is less than 1:500, which ensures stable installation of the movable frame and has a certain flexibility in the axial direction of the thrust transmission; the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends, and the thin part is an elastic deformation area that can provide elastic compensation in the thrust axial direction.

[0012] Further, each of the limiting rods comprises a fixed seat, a transverse adjusting screw rod, and a stop head; one side of the fixed seat and a corresponding position on the fixed frame are provided with a through bolt hole, and the fixed seat is installed on the fixed frame by a fixing bolt; one end of the transverse adjusting screw rod is threadedly connected to the fixed seat through the fixed frame, the other end passes through a first through hole provided on the movable frame and is slidably connected to the first through hole, and the end part is provided with the stop head whose diameter is larger than that of the end part of the transverse adjusting screw rod; the distance between the stop head and the first through hole is 2-3 mm, and the distance between the stop head and the first through hole can be adjusted by rotating the transverse adjusting screw rod;

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

[0014] Further, the rear constraint limiting roller is a bearing type roller, and a height adjusting structure is arranged on the roller support of the roller, the positioning height of the roller can be adjusted by a screw rod, and then the position of the movable frame in the fixed frame is adjusted; each group of two rear spring plates are respectively arranged between the outer side surfaces of the four frame beams of the fixed frame and the end surfaces of the small end of the movable frame; the installation positions of the rear spring plates meet the following conditions: the distance between the two rear spring plates in the transverse direction is greater than the distance between the two rear spring plates in the longitudinal direction, and the two rear spring plates in each group are parallel to each other and perpendicular to the frame beam of the fixed frame on which the two rear spring plates are installed.

[0015] Further, the flexible connection support assembly comprises an adjustable support seat and a flexible support piece, the flexible support piece has a structure of thin in the middle and thick at both ends, one end of the flexible support piece is installed on the adjustable support seat, and the other end of the flexible support piece is provided with a first connecting seat, and the first connecting seat is provided with a first roller;

[0016] The adjustable support seat comprises a first adjusting seat connected with one end of the flexible support piece, a first support seat arranged below the first adjusting seat, a first locking nut fixedly connected with the inner side wall at the bottom of the first adjusting seat, and a first adjusting screw rod; the screw rod end of the first adjusting screw rod penetrates through the first support seat and extends into the interior of the first adjusting seat, is threadedly connected with the first locking nut, and is rotationally connected with the first support seat; one side of the lower end of the first adjusting seat is provided with a first guide plate, and the inner side wall of the first guide plate is attached to the side wall of the first support seat;

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

[0018] The first support seat is arranged on the inner side wall of the lower part of the fixed frame; the first locking nut threadedly connected with the first adjusting screw rod drives the first adjusting seat to ascend or descend under the guidance of the first guide plate by rotating the first adjusting screw rod, so as to adjust the attachment of the first roller to the outer side surface below the middle section of the movable frame; the first roller ensures that the friction in the direction of the thrust axis is small when the flexible connection support assembly is attached to the outer side surface below the middle section of the movable frame, and the flexible support piece is made of spring steel and can support a certain lateral deformation.

[0019] Further, the disc spring support assembly comprises a second support seat arranged on the inner side wall of the upper part of the fixed frame, a second adjusting seat arranged below the second support seat, a second connecting seat in sliding connection with the second adjusting seat, a second adjusting screw rod, and a second locking nut; a second through hole is formed in the second adjusting seat, a boss is arranged on the inner wall of the second through hole, the nut end of the second adjusting screw rod extends into the second through hole and abuts against the boss, the screw rod end extends into the interior of the second support seat and is threadedly connected with the second locking nut, and the second locking nut is rotationally connected with the inner side wall at the bottom of the second support seat; a limiting plate is sleeved on the second adjusting screw rod, and the limiting plate is fixedly connected with the upper surface of the second adjusting seat;

[0020] The small end of the second connecting seat extends into the second through hole and is in sliding connection with the second adjusting support, and at least two disc springs are arranged on both sides of the small end between the second adjusting support and the large end of the second connecting seat; and a second roller is arranged at the end of the large end of the second connecting seat;

[0021] One side of the second supporting seat is provided with an opening, and a second guide plate is arranged below one side of the opening, and the inner side wall of the second guide plate is attached to the side wall of the second adjusting support; by rotating the second lock nut, the second adjusting screw threadedly connected with the second lock nut is driven to drive the second adjusting support to ascend or descend under the guidance of the second guide plate, so that the second roller is adjusted to be attached to the outer side surface above the middle segment of the movable frame; the second roller ensures that the frictional force in the thrust axis direction is small when the disc spring supporting assembly is attached to the upper side of the middle segment of the movable frame, and the disc spring can bear a certain up-down lateral force.

[0022] The beneficial effects of the present application are as follows:

[0023] 1. The inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the front spring plate and the rear spring plate are both designed as rectangular variable cross sections, and the axial and radial stiffness ratio is less than 1:500, so that the radial direction can stably bear the lateral force, and the small axial stiffness can also ensure efficient transmission of the thrust.

[0024] 2. The inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the front constraint limiting roller, the rear constraint limiting roller and the middle segment constraint limiting device jointly assist in supporting the gravity of the movable frame and overcoming the lateral force, and the roller structure in the front constraint limiting roller, the rear constraint limiting roller and the middle segment constraint limiting device reduces the frictional force borne by the movable frame, thereby ensuring efficient and accurate transmission of the thrust.

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

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

[0027] 5. The inclined liquid rocket engine thrust frame with a composite constraint structure, wherein the flexible connecting supporting assembly and the disc spring supporting assembly are correspondingly installed above and below, can elastically compensate the radial deformation of the middle segment of the movable frame due to stress expansion, and increase the stability of the movable frame. BRIEF DESCRIPTION OF DRAWINGS

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

[0029] Figure 2 is a structural schematic diagram of a front constraint device of the embodiment of the application;

[0030] Figure 3 is a structural schematic diagram of a middle constraint device of the embodiment of the application;

[0031] Figure 4 is a structural schematic diagram of a rear constraint device of the embodiment of the application;

[0032] Figure 5 is a structural schematic diagram of a front spring plate and a rear spring plate of the embodiment of the application, wherein (a) is the front spring plate and (b) is the rear spring plate;

[0033] Figure 6 is an enlarged view of a limiting rod connecting portion of the front constraint device of the embodiment of the application;

[0034] Figure 7 is a structural schematic diagram of a flexible connecting support assembly of the embodiment of the application;

[0035] Figure 8 is a structural schematic diagram of a disc spring support assembly of the embodiment of the application.

[0036] Reference signs:

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

[0038] The technical solutions of the present application will be described clearly and completely below in combination with the drawings and embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0039] The tilt liquid rocket engine thrust frame with the composite constraint structure provided by the embodiments of the present application comprises a fixed frame 4 of a full-enclosing frame structure installed obliquely, and a movable frame 5 in a two-section frustum structure, the movable frame 5 being installed inside the fixed frame 4 through a composite constraint structure. Figure 1 The composite constraint structure comprises a front section constraint device 1, a middle section constraint device 2 and a rear section constraint device 3.

[0040] As shown in Figure 2 The front section constraint device 1 is installed between the fixed frame 4 and the large end of the movable frame 5, and comprises a limiting rod 11, a front constraint limiting roller 12 and a front spring plate 13.

[0041] The limiting rod 11 is provided in four pieces, one end of each of which is fixedly installed at a corner position of the fixed frame 4, and the other end of each of which penetrates through a corner of the movable frame 5 and is provided with a stopper head 113. Figure 6 Each of the limiting rods 11 comprises a fixed seat 111, a transverse adjusting screw rod 112 and the stopper head 113. One side of the fixed seat 111 and a corresponding position on the fixed frame 4 are provided with a penetrating bolt hole, and the fixed seat 111 is installed on the fixed frame 4 through a fixing bolt 114. One end of the transverse adjusting screw rod 112 penetrates through the fixed frame 4 and is threadedly connected with the fixed seat 111, the other end of the transverse adjusting screw rod 112 penetrates through a first through hole 51 provided in the movable frame 5 and is slidably connected with the first through hole 51, and the end of the transverse adjusting screw rod 112 is provided with the stopper head 113, the diameter of which is larger than that of the end of the transverse adjusting screw rod 112. The distance between the stopper head 113 and the first through hole 51 can be adjusted by rotating the transverse adjusting screw rod 112, and the distance is 2-3 mm. The stopper head 113 can prevent the movable frame 5 from slipping off, the transverse adjusting screw rod 112 is slidably connected with the first through hole 51, and the distance between the stopper head 113 and the first through hole 51 is 2-3 mm, which can meet the requirement of displacement and deformation of the movable frame in the thrust axial direction during the engine thrust test.

[0042] The four front constraint limiting rollers 12 are installed on the inner side of the four corners of the fixed frame 4 through roller supports, and the side walls thereof are in contact with the four corners of the movable frame 5; the angle between the axis of each front constraint limiting roller 12 and the two frame beams of the corresponding fixed frame 4 is 45°; each group of two front spring plates 13 is installed on the two sides of the four front constraint limiting rollers 12, is perpendicular to the two frame beams of the corresponding fixed frame 4, and is symmetrically arranged about the diagonal line of the corresponding fixed frame 4; the front constraint limiting roller 12 is a bearing type roller, and a height adjusting structure is arranged on the roller support thereof, so that the positioning height of the roller can be adjusted through a screw rod, and then the position of the movable frame 5 in the fixed frame 4 is adjusted.

[0043] As shown in Figure 3 , the middle segment constraint limiting device 2 is installed between the middle segment of the fixed frame 4 and the movable frame 5, and includes a flexible connection support assembly 21 and a disc spring support assembly 22.

[0044] Referring to Figure 7 , the flexible connection support assembly 21 includes an adjustable support seat 211 and a flexible support 212, the length of the middle thin segment of the flexible support 212 is less than the length of the two end thick segments, and the ratio of the diameter of the middle thin segment to the diameter of the two end thick segments is less than 1 / 3; one end of the flexible support 212 is installed on the adjustable support seat 211, and the other end is provided with a first connecting seat 213, and the first connecting seat 213 is provided with a first roller 214.

[0045] The adjustable support seat 211 includes a first adjusting seat 2111 connected with one end of the flexible support 212, a first support seat 2112 below the first adjusting seat 2111, a first lock nut 2113 fixedly connected with the inner side wall of the bottom of the first adjusting seat 2111, and a first adjusting screw rod 2114; the screw end of the first adjusting screw rod 2114 passes through the first support seat 2112 and extends into the interior of the first adjusting seat 2111, is threadedly connected with the first lock nut 2113, and is rotationally connected with the first support seat 2112; the first adjusting seat 2111 is provided with a first guide plate 2115 on one side of the lower end thereof, and the inner side wall of the first guide plate 2115 is in abutment with the side wall of the first support seat 2112.

[0046] The first support seat 2112 is installed on the inner side wall of the lower part of the fixed frame 4; by rotating the first adjusting screw rod 2114, the first lock nut 2113 threadedly connected with the first adjusting screw rod 2114 drives the first adjusting seat 2111 to ascend or descend under the guidance of the first guide plate 2115, so as to adjust the abutment of the first roller 214 with the outer side of the lower part of the middle segment of the movable frame 5; the first roller 214 ensures that the friction force in the direction of the thrust axis is small when the flexible connection support assembly 21 is in abutment with the lower part of the middle segment of the movable frame 5, and the flexible support 212 is made of spring steel and can support a certain lateral deformation.

[0047] Referring toFigure 8 The disc spring supporting assembly 22 comprises a second supporting seat 221 mounted on the inner side wall of the upper part of the fixed frame 4, a second adjusting seat 222 arranged below the second supporting seat 221, a second connecting seat 223 in sliding connection with the second adjusting seat 222, a second adjusting screw 224, and a second lock nut 225; the second adjusting seat 222 is provided with a second through hole 2221, and a boss 2222 is arranged on the inner wall of the second through hole 2221; the screw cap end of the second adjusting screw 224 extends into the second through hole 2221 and abuts against the boss 2222, the screw rod end extends into the second supporting seat 221 and is in threaded connection with the second lock nut 225, and the second lock nut 225 is rotatably connected with the inner side wall of the bottom of the second supporting seat 221; a limiting plate 226 is sleeved on the second adjusting screw 224, and the limiting plate 226 is fixedly connected with the upper surface of the second adjusting seat 222;

[0048] The small end of the second connecting seat 223 extends into the second through hole 2221 and is in sliding connection with the second adjusting seat 222; at least two disc springs 227 are sleeved on both sides of the small end between the second adjusting seat 222 and the large end of the second connecting seat 223; and the large end of the second connecting seat 223 is provided with a second roller 228;

[0049] One side of the second supporting seat 221 is provided with an opening, and a second guide plate 2211 is arranged below the opening; the second guide plate 2211 is in abutment with the side wall of the second adjusting seat 222; the second lock nut 225 is rotated on the inner side wall of the bottom of the second supporting seat 221, and the second adjusting screw 224 in threaded connection with the second lock nut 225 drives the second adjusting seat 222 to ascend or descend under the guidance of the second guide plate 2211, so as to adjust the abutment of the second roller 228 with the outer side surface above the middle segment of the movable frame 5; the second roller 228 ensures that the friction force in the direction of the thrust axis is small when the disc spring supporting assembly 22 is in abutment with the middle segment of the movable frame 5, and the disc spring 227 can bear a certain upward and lateral force.

[0050] The installation positions of the flexible connecting supporting assembly 21 and the disc spring supporting assembly 22 correspond to each other in up and down directions.

[0051] As shown in Figure 4 , the rear segment constraint device 3 is installed between the fixed frame 4 and the small end of the movable frame 5, and comprises a rear constraint limiting roller 31 and a rear spring plate 32.

[0052] The three rear constraint limiting rollers 31 on the left and right are each arranged in a U-shaped distribution on the fixed frame 4 through a roller support, and are in contact with the outer side wall of the part of the movable frame 5 extending into the three rollers; the rear constraint limiting rollers 31 are bearing type rollers, and a height adjusting structure is arranged on the roller support, so that the positioning height of the roller can be adjusted through a screw rod, and the position of the movable frame 5 in the fixed frame 4 is adjusted; the rear spring plates 32 are four groups, each group has two, and each of the two rear spring plates 32 in each group is arranged between the outer side of the four frame beams of the fixed frame 4 and the end face of the small end of the movable frame 5; the installation position of the rear spring plates 32 meets the following conditions: the distance between the two rear spring plates 32 in the transverse direction is greater than the distance between the two rear spring plates 32 in the longitudinal direction, and the two rear spring plates 32 in each group are parallel to each other and perpendicular to the frame beam of the fixed frame 4 where they are installed.

[0053] As shown in Figure 5 The front spring plate 13 is of a rectangular variable cross-section structure, the ratio of the length to the width is 5, and the width is 200 mm; the cross-section of the front spring plate 13 changes in the order of thick-thin-thick-thin-thick, the thick-thin ratio is 2:1, and the thickness of the thin part is 8 mm; the length ratio of each part of the front spring plate 13 is 1:1:2:1:1, and the ratio of the axial and radial stiffness is less than 1:500, so as to ensure the stable installation of the movable frame 5 and the flexibility in the axial direction of the thrust transmission.

[0054] The rear spring plate 32 is of a rectangular variable cross-section structure, the cross-section changes in the order of thick-thin-thick-thin-thick, and the parameters are the same as those of the front spring plate 13 except that the length of the thick part in the middle is different; the length ratio of each part of the rear spring plate 32 is 1:1:5:1:1; because the large end of the movable frame 5 is closer to the test liquid rocket engine, the vibration and axial deformation are larger, so the front spring plate 13 is selected to be short, so as to ensure the axial stability; the small end of the movable frame 5 is farther away from the engine, and the axial deformation is small, so the rear spring plate 32 is selected to be long, so as to ensure the low axial stiffness and improve the thrust transmission ratio.

[0055] In summary, the inclined liquid rocket engine thrust frame with a composite constraint structure provided in the embodiment can bear the gravity of the movable frame 5 in the thrust frame, ensure that the force transmission path of the movable frame 5 is on the thrust axis, and also bear the bending moment generated by the engine and the lateral force caused by vibration and other reasons during the engine test, so as to ensure the stability of the thrust frame and the thrust axis, and thus realize the accurate transmission and measurement of the thrust.

Claims

1. A tilting liquid rocket engine thrust stand with a composite restraint structure, comprising a stationary frame (4) of a tilting mounted full-enclosing frame structure, and a movable frame (5) in the form of a two-stage frustum structure, said movable frame (5) being mounted inside the stationary frame (4) by a restraint structure; characterized in that: The constraint structure is a composite constraint structure, comprising a front constraint device (1), a middle constraint device (2) and a rear constraint device (3); The front constraint device (1) is installed between the fixed frame (4) and the large end of the movable frame (5), and comprises limiting rods (11), front constraint limiting rollers (12) and front spring plates (13); the limiting rods (11) are four in number, one end of each of which is fixedly installed at the four corner positions of the fixed frame (4), and the other end of each of which penetrates through the corner of the movable frame (5) and is provided with a stop head to prevent the movable frame (5) from slipping off; the front constraint limiting rollers (12) are four in number, each of which is installed on the inner side of the four corner positions of the fixed frame (4) through a roller support, and the side wall of each of which is in contact with the four corner positions of the movable frame (5); the front spring plates (13) are four in number, each of which is installed between the front end of the fixed frame (4) and the large end of the movable frame (5); the front spring plates (13) are of a rectangular variable cross-section structure, the ratio of the length to the width is 3-5, and the width is 150-250 mm; the cross-section of the front spring plates (13) changes in the order of thick-thin-thick-thin-thick, the thick-thin 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 plates (13) is 1:1:2:1:1, the axial and radial stiffness ratio is less than 1:500, so that the movable frame (5) is stably installed while having a certain flexibility in the axial direction of the thrust transmission; and the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends; The middle constraint device (2) is installed between the middle sections of the fixed frame (4) and the movable frame (5), and comprises flexible connection support assemblies (21) and disc spring support assemblies (22); the flexible connection support assemblies (21) are two in number, are installed on the inner side walls of the lower part of the fixed frame (4), and the upper ends thereof are in contact with the outer side surfaces below the middle section of the movable frame (5); the disc spring support assemblies (22) are two in number, are installed on the inner side walls of the upper part of the fixed frame (4), and the lower ends thereof are in contact with the outer side surfaces above the middle section of the movable frame (5); and the installation positions of the flexible connection support assemblies (21) and the disc spring support assemblies (22) correspond to each other in up-down direction; The rear constraint device (3) is installed between the small ends of the fixed frame (4) and the movable frame (5), and comprises rear constraint limiting rollers (31) and rear spring plates (32); the rear constraint limiting rollers (31) are three in number on the left and the right, and the three rear constraint limiting rollers (31) on the left and the right are installed on the fixed frame (4) in a U-shaped distribution through roller supports and are in contact with the outer side walls of the part of the movable frame (5) that extends into the three rollers; the rear spring plates (32) are four in number, each of which is installed between the rear end of the fixed frame (4) and the small end of the movable frame (5).

2. The inclined liquid rocket engine thrust frame with a composite constraint structure according to claim 1, 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 of the rear spring plate (32) changes in the order of thick-thin-thick-thin-thick, the thick-thin ratio is 2:1, and the thin part has a thickness of 5-10 mm; the length ratio of each part of the rear spring plate (32) is 1:1:5:1:1, the axial and radial stiffness ratio is less than 1:500, which ensures the stable installation of the movable frame (5) and has a certain flexibility in the axial direction of the thrust transmission; the thick parts at both ends are connected to the fixed frame and the movable frame as connecting ends, and the thin part is an elastic deformation area providing elastic compensation in the direction of the thrust axis.

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

4. The inclined liquid rocket engine thrust frame with a composite constraint structure according to claim 1, characterized in that: The rear constraint limiting roller (31) is a bearing type roller, and a height adjusting structure is arranged on the roller support of the rear constraint limiting roller (31), the positioning height of the rear constraint limiting roller is adjusted by a screw rod, and then the position of the movable frame (5) in the fixed frame (4) is adjusted; each group of two rear spring plates (32) is installed between the outer side surface 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 plate (32) meets the following conditions: the distance between the two rear spring plates (32) in the transverse direction is greater than the distance 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 it is installed.

5. The tilting liquid rocket engine thrust frame with composite constraint structure according to claim 1, characterized in that: the flexible connecting support assembly (21) comprises an adjustable support seat (211) and a flexible support (212), the flexible support (212) is of a structure with thin middle and thick ends, one end of which is mounted on the adjustable support seat (211), and the other end is provided with a first connecting seat (213), and the first connecting seat (213) is provided with a first roller (214); the adjustable support seat (211) comprises a first adjusting seat (2111) connected with one end of the flexible support (212), a first support seat (2112) disposed below the first adjusting seat (2111), a first lock nut (2113) fixedly connected with the inner side wall of the bottom of the first adjusting seat (2111), and a first adjusting lead screw (2114); the screw end of the first adjusting lead screw (2114) penetrates through the first support seat (2112) and extends into the interior of the first adjusting seat (2111), and is in threaded connection with the first lock nut (2113); the first adjusting lead screw (2114) is in rotational connection with the first support seat (2112); one side of the lower end of the first adjusting seat (2111) is provided with a first guide plate (2115), and the inner side wall of the first guide plate (2115) is in abutment with the side wall of the first support seat (2112); the length of the thin middle section of the flexible support (212) is less than the length of the thick end sections, and the ratio of the diameter of the thin middle section to the diameter of the thick end sections is less 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 adjusting lead screw (2114), the first lock nut (2113) threadedly connected therewith drives the first adjusting seat (2111) to ascend or descend under the guidance of the first guide plate (2115), so as to adjust the abutment of the first roller (214) with the outer side surface below the middle section of the movable frame (5).

6. The tilting liquid rocket engine thrust frame with composite constraint structure according to claim 1, characterized in that: The disc spring supporting assembly (22) comprises a second supporting seat (221) mounted on the inner side wall of the upper part of the fixed frame (4), a second adjusting seat (222) arranged below the second supporting seat (221), a second connecting seat (223) in sliding connection with the second adjusting seat (222), a second adjusting screw (224) and a second lock nut (225); the second adjusting seat (222) is provided with a second through hole (2221) in which a boss (2222) is arranged on the inner wall, the screw nut end of the second adjusting screw (224) extends into the second through hole (2221) and abuts against the boss (2222), the screw rod end extends into the second supporting seat (221) and is in threaded connection with the second lock nut (225), and the second lock nut (225) is rotatably connected with the inner side wall of the bottom of the second supporting seat (221); a limiting plate (226) is sleeved on the second adjusting screw (224), and the limiting plate (226) is fixedly connected with the upper surface of the second adjusting seat (222); The small end of the second connecting seat (223) extends into the second through hole (2221) and is in sliding connection with the second adjusting seat (222), and at least two disc springs (227) are sleeved on both sides of the small end between the second adjusting seat (222) and the large end of the second connecting seat (223); the large end of the second connecting seat (223) is provided with a second roller (228); One side of the second supporting seat (221) is provided with an opening, and a second guide plate (2211) is arranged below one side of the opening, and the inner side wall of the second guide plate (2211) is in abutment with the side wall of the second adjusting seat (222); by rotating the second lock nut (225), the second adjusting screw (224) in threaded connection with the second lock nut (225) drives the second adjusting seat (222) to ascend or descend under the guidance of the second guide plate (2211), so as to adjust the abutment of the second roller (228) with the outer side surface above the middle part of the movable frame (5).

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