阅读说明：本技术 一种整流罩的轴向分离装置以及运载火箭 (Axial separation device of fairing and carrier rocket ) 是由 周思博 翟海涛 胡吉军 徐国伟 代志刚 刘家欣 李义飞 严波 黄小青 王震 于 2021-10-25 设计创作，主要内容包括：本发明公开了一种整流罩的轴向分离装置以及运载火箭。该发明属于运载火箭技术领域,其中的整流罩的轴向分离装置的推杆的第一端可伸缩地连接在套筒的第二端内；弹性件两端分别和套筒的第一端和推杆的第一端连接；锁杆的第一端可拆卸地连接在套筒的第一端,锁杆的第二端穿过弹性件并与推杆的第一端连接；推杆的第二端滑动连接在滑槽中,推杆的中心轴和滑槽的长度方向的中心轴之间具有倾角。本发明能够避免整流罩在分离时与有效载荷发生碰撞,其中的整流罩的轴向分离装置的安装方式充分利用了空间结构,不会占用整流罩过多的包络空间,同时也便于整流罩与末级之间的装配,具有很好的实用性、新颖性以及创造性。(The invention discloses an axial separation device of a fairing and a carrier rocket. The invention belongs to the technical field of carrier rockets, wherein a first end of a push rod of an axial separation device of a fairing is telescopically connected into a second end of a sleeve; two ends of the elastic piece are respectively connected with the first end of the sleeve and the first end of the push rod; the first end of the lock rod is detachably connected to the first end of the sleeve, and the second end of the lock rod penetrates through the elastic piece and is connected with the first end of the push rod; the second end of the push rod is connected in the sliding groove in a sliding mode, and an inclination angle is formed between the central shaft of the push rod and the central shaft of the sliding groove in the length direction. The invention can avoid the collision of the fairing with the effective load when separating, the installation mode of the axial separation device of the fairing fully utilizes the space structure, does not occupy excessive enveloping space of the fairing, is convenient for the assembly between the fairing and the final stage, and has good practicability, novelty and creativity.)

1. An axial fairing separation device suitable for the separation of a fairing (1) from a final stage (3) on a launch vehicle, characterized in that it comprises:

a sleeve (4) having opposite first and second ends;

a push rod (5) having opposite first and second ends, the first end of the push rod (5) being telescopically connected within the second end of the sleeve (4);

an elastic member (6) having a first end and a second end opposite to each other, the first end of the elastic member (6) being connected to the first end of the sleeve (4), the second end of the elastic member (6) being connected to the first end of the push rod (5);

the locking rod (7) is provided with a first end and a second end which are opposite, the first end of the locking rod (7) is detachably connected to the first end of the sleeve (4), and the second end of the locking rod (7) penetrates through the elastic piece (6) and is connected with the first end of the push rod (5);

the base (8) is provided with a sliding groove (9), the second end of the push rod (5) is connected in the sliding groove (9) in a sliding mode, and an inclination angle is formed between the central shaft of the push rod (5) and the central shaft of the sliding groove (9) in the length direction.

2. An axial fairing separation as recited in claim 1, further comprising:

a first fixing piece (10), wherein a first end of the first fixing piece (10) is connected with a first end of the sleeve (4), and a second end of the first fixing piece (10) is used for being connected with the inner circumferential surface of the fairing (1);

and a second fixing piece (11), wherein a first end of the second fixing piece (11) is connected with a second end of the sleeve (4), and a second end of the second fixing piece (11) is used for being connected with the inner peripheral surface of the fairing (1).

3. An axial fairing separation as recited in claim 1, further comprising:

the screw rod (12) is connected with the first end of the lock rod (7) and penetrates through an opening at the end part of the first end of the sleeve (4);

and the nut (13) is in threaded connection with the screw (12) and is arranged outside the sleeve (4).

4. A fairing axial separation as claimed in claim 1, characterised in that said device further comprises a mass (14) disposed in said sleeve (4) with clearance, having opposite first and second ends, said second end of said spring (6) and said second end of said locking bar (7) being connected to said first end of said mass (14), said second end of said mass (14) being connected to said first end of said push bar (5).

5. A fairing axial separation device as claimed in claim 1, characterised in that the second end of the push rod (5) is provided with a slider (15), the two sides of the slider (15) are circular planes, the circumference of the slider (15) is curved, and the circumference of the slider (15) is connected to the second end of the push rod (5).

6. A fairing axial separation device as claimed in claim 5, characterized in that the two side faces of the runner (9) are plane, the bottom face of the runner (9) is arc-shaped, the two side faces of the sliding block (15) are arranged with clearance from the two side faces of the runner (9), and the peripheral face of the sliding block (15) is connected with the bottom face of the runner (9).

7. A launch vehicle, characterized in that it comprises a plurality of fairing axial separation devices according to any of claims 1-6, said devices being arranged at equi-angular intervals around the central axis of the fairing (1), said sleeve (4) being attached to the inner circumferential surface of the fairing (1), the distance between the first end of the sleeve (4) and the central axis of the fairing (1) being less than the distance between the second end of the sleeve and the central axis of the fairing (1), said base (8) being attached to the final stage (3), the central axis of the chute (9) in the length direction being located in the plane formed by the central axis of the sleeve (4) and the central axis of the fairing (1).

8. A launch vehicle according to claim 7, characterised in that the angle between the central axis of the sleeve (4) and the central axis of the fairing (1) is α, the angle between the length of the chute (9) and a plane perpendicular to the central axis of the fairing (1) is θ, and the equation for α and θ satisfies the following equation:

μ＜tan(α+θ)；

wherein the friction coefficient between the second end of the push rod (5) and the sliding groove (9) is mu.

9. A launch vehicle according to claim 8, characterised in that the length-wise dimension of said chute (9) satisfies the following formula:

K≥Lsinα/cosθ；

the length direction of the sliding groove (9) is K, and the maximum extension length of the push rod (5) is L.

10. A launch vehicle according to any one of claims 8 to 9, characterised in that α is in the interval 0 < α ≦ 20 °.

Technical Field

The invention belongs to the technical field of carrier rockets, and particularly relates to an axial separation device of a fairing and a carrier rocket.

Background

When the carrier rocket flies to the height with rarefied atmosphere, the atmospheric resistance to the carrier rocket is very small, at the moment, the protection of the fairing is not needed for the effective load, and meanwhile, in order to reduce the weight of the structure to save fuel and improve the flight characteristic, the fairing needs to be separated. The current fairing separation mode mainly comprises axial separation and peeling separation, wherein the axial separation mode of the fairing is to unlock the connection between the fairing and the final stage through an explosive bolt and then realize the separation of the fairing from the upper part of the final stage along the axial direction through the action of an axial separation device arranged between the fairing and the final stage.

In the fairing separation process, because a long overlapping distance exists between the fairing and the final stage, the inertia of the fairing, the deviation of the acting force of the separation device, the form and position tolerance of the separation device and the like can cause the fairing to collide with an effective load, in addition, along with the continuous improvement of the carrying capacity of a carrier rocket, the effective load occupies more and more effective enveloping space inside the fairing, the space for installing the separation device is more and more limited, meanwhile, the existing fairing is mainly divided into a conical section and a column section, particularly, when the axial width of the column section part is small, the axial installation of the separation device is not enough, the separation device needs to be displaced towards the direction of a central shaft of the fairing so as to realize the axial installation of the separation device, and the separation device occupies too much enveloping space of the fairing.

Disclosure of Invention

The invention aims at solving at least to some extent the technical problems of the fairing colliding with the payload during separation, the separation device taking up too much space for the fairing envelope and the fairing not being easy to fit onto the final stage. Therefore, the invention provides an axial separation device of a fairing and a carrier rocket.

The technical scheme of the invention is as follows:

in one aspect, the present invention provides an axial fairing separation apparatus for use in the separation of a fairing from a final stage on a launch vehicle, the apparatus comprising:

a sleeve having opposing first and second ends;

a push rod having opposite first and second ends, the first end of the push rod being telescopically coupled within the second end of the sleeve;

an elastic member having opposite first and second ends, the first end of the elastic member being connected to the first end of the sleeve, the second end of the elastic member being connected to the first end of the push rod;

the locking rod is provided with a first end and a second end which are opposite, the first end of the locking rod is detachably connected to the first end of the sleeve, and the second end of the locking rod penetrates through the elastic piece and is connected with the first end of the push rod;

the base is provided with a sliding groove, the second end of the push rod is connected in the sliding groove in a sliding mode, and an inclination angle is formed between the central shaft of the push rod and the central shaft of the sliding groove in the length direction.

Further, the apparatus further comprises:

the first end of the first fixing piece is connected with the first end of the sleeve, and the second end of the first fixing piece is used for being connected with the inner peripheral surface of the fairing;

and a first end of the second fixing piece is connected with a second end of the sleeve, and a second end of the second fixing piece is used for being connected with the inner peripheral surface of the fairing.

Further, the apparatus further comprises:

the screw rod is connected with the first end of the lock rod and penetrates through the opening at the end part of the first end of the sleeve;

and the nut is in threaded connection with the screw rod and is arranged outside the sleeve.

Further, the device still includes that the clearance sets up the briquetting in the sleeve has relative first end and second end, the second end of spring with the second end of locking lever all with the first end of briquetting is connected, the second end of briquetting with the first end of push rod is connected.

Further, the second end of push rod is provided with the slider, two sides of slider are the circular plane, the global of slider is the arc, the global of slider with the second end of push rod is connected.

Further, two sides of the sliding chute are planes, the bottom surface of the sliding chute is arc-shaped, two sides of the sliding block and two sides of the sliding chute are arranged in a clearance mode, and the peripheral surface of the sliding block is connected with the bottom surface of the sliding chute.

In another aspect, the invention further provides a launch vehicle comprising the above-mentioned fairing axial separation device, wherein a plurality of the devices are arranged at equal angular intervals around a central axis of the fairing, the sleeve is connected to an inner circumferential surface of the fairing, a distance between a first end of the sleeve and the fairing central axis is smaller than a distance between a second end of the sleeve and the fairing central axis, the base is connected to the final stage, and a central axis of the chute in a length direction is located in a plane formed by the sleeve central axis and the fairing central axis.

Further, an included angle between the central axis of the sleeve and the central axis of the fairing is alpha, an included angle between the length direction of the sliding groove and a plane perpendicular to the central axis of the fairing is theta, and the alpha and the theta satisfy the following formula:

μ＜tan(α+θ)；

wherein the coefficient of friction between the second end of the push rod and the chute is mu.

Further, the size of the sliding chute in the length direction satisfies the following formula:

K≥Lsinα/cosθ；

the sliding groove is formed in the bottom of the push rod, the K is the size of the sliding groove in the length direction, and the L is the maximum extending length of the push rod.

Furthermore, the range of alpha is more than 0 and less than or equal to 20 degrees.

The embodiment of the invention at least has the following beneficial effects:

the application provides a carrier rocket, which comprises an axial separation device of a fairing, wherein two ends of a lock rod are respectively connected with a sleeve and a push rod, an elastic piece is in a compression state at the moment, a first end of a chute is far away from the inner circumferential surface of the fairing, a second end of the chute is close to the inner circumferential surface of the fairing, then the first end of the chute is connected with a second end of the push rod, the second end of the chute is far away from the second end of the push rod relative to the first end of the chute in the axial direction of the push rod, after the fairing is fixedly connected with a final stage by an explosion bolt, the first end of the lock rod is released from being connected with the first end of the sleeve, at the moment, the fairing cannot move because of being fixedly connected with the final stage, the elastic piece is still in the compression state, so that the installation of the device on the carrier rocket is realized, after the explosion bolt is unlocked, the fairing is fixedly connected with the final stage, under the action force of the elastic piece, the push rod stretches out from the sleeve, so that the second end of the push rod moves from the first end of the sliding groove to the second end of the sliding groove, the fairing axially moves relative to the final stage, the collision between the fairing and the effective load caused by the deviation of the acting force of the device and the form and position tolerance of the device is avoided, along with the full stretching out of the push rod, the fairing is separated from the final stage under the action of inertia, the second end of the push rod is separated from the sliding groove, and finally the axial separation of the fairing is realized.

In conclusion, the carrier rocket provided with the fairing axial separation device can avoid the fairing from colliding with the effective load during separation, the installation mode of the device fully utilizes the space structure, does not occupy excessive enveloping space of the fairing, is convenient for assembly between the fairing and the final stage, and has good practicability, novelty and creativity.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic view of an axial fairing separation apparatus according to an embodiment of the present invention;

fig. 2 is a schematic view of the structure of the apparatus of fig. 1 assembled in a launch vehicle.

Reference numerals:

1-a fairing; 2-payload; 3-the final stage; 4-a sleeve; 5-a push rod; 6-an elastic member; 7-locking bar; 8-a base; 9-a chute; 10-a first fixture; 11-a second fixture; 12-a screw; 13-a nut; 14-briquetting; 15-sliding block.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

The invention is described below with reference to specific embodiments in conjunction with the following drawings:

fig. 1 shows an axial separating device of a fairing according to an embodiment of the present invention, which, in conjunction with fig. 1, includes a sleeve 4, a push rod 5, an elastic member 6, a lock rod 7, a base 8 and a sliding groove 9.

The sleeve 4 in the embodiment of the present application has opposite first and second ends, the sleeve 4 has opposite first and second ends, the first end of the push rod 5 is telescopically connected in the second end of the sleeve 4, the elastic member 6 has opposite first and second ends, the first end of the elastic member 6 is connected with the first end of the sleeve 4, the second end of the elastic member 6 is connected with the first end of the push rod 5, the lock rod 7 has opposite first and second ends, the first end of the lock rod 7 is detachably connected with the first end of the sleeve 4, the second end of the lock rod 7 passes through the elastic member 6 and is connected with the first end of the push rod 5, the base 8 is provided with a sliding groove 9, the second end of the push rod 5 is slidably connected in the sliding groove 9, and an inclination angle is formed between the central axis of the push rod 5 and the central axis of the sliding groove 9 in the length direction.

Further, the device is suitable for separation of a fairing 1 and a final stage 3 on a launch vehicle, in the launch vehicle, a plurality of devices are arranged at equal angular intervals around the central axis of the fairing 1, a sleeve 4 is connected on the inner circumferential surface of the fairing 1, the distance between the first end of the sleeve 4 and the central axis of the fairing 1 is smaller than the distance between the second end of the sleeve 4 and the central axis of the fairing 1, a base 8 is connected on the final stage 3, and the central axis of the sliding chute 9 in the length direction is positioned in the plane formed by the central axis of the sleeve 4 and the central axis of the fairing 1.

Specifically, with reference to fig. 1 and 2, two ends of a lock rod 7 are respectively connected with a sleeve 4 and a push rod 5, at this time, an elastic member 6 is in a compressed state, a first end of a chute 9 is far away from the inner circumferential surface of a fairing 1, a second end of the chute 9 is close to the inner circumferential surface of the fairing 1, then the first end of the chute 9 is connected with a second end of the push rod 5, the second end of the chute 9 is far away from the second end of the push rod 5 relative to the first end of the chute 9 in the axial direction of the push rod 5, after the fairing 1 is fixedly connected with a final stage 3 by using an explosive bolt, the first end of the lock rod 7 is released from being connected with the first end of the sleeve 4, at this time, the fairing 1 cannot move because of being fixedly connected with the final stage 3, at this time, the elastic member 6 is still in a compressed state, so as to realize the installation of the device on a carrier rocket, and after the explosive bolt is unlocked, the fairing 1 and the final stage 3 lose the fixed connection, under the action of the elastic element 6, the push rod 5 protrudes from the sleeve 4, so that the second end of the push rod 5 moves from the first end of the sliding slot 9 to the second end of the sliding slot 9, the fairing 1 moves axially relative to the final stage 3, so as to avoid the deviation of the acting force of the device and the form and position tolerance of the device to cause the collision of the fairing 1 and the payload 2, along with the full extension of the push rod 5, the fairing 1 is separated from the final stage 3 under the action of inertia, the second end of the push rod 5 is also separated from the sliding groove 9, and finally the axial separation of the fairing 1 is realized, besides, since the distance between the first end of the sleeve 4 and the central axis of the fairing 1 is smaller than the distance between the second end of the sleeve 4 and the central axis of the fairing 1, the device is obliquely arranged in the fairing 1, and the limited enveloping space of the fairing 1 is reasonably utilized, so that the device does not occupy too much enveloping space of the fairing 1.

In the embodiment of the present application, 3, 4, 5, etc. devices may be disposed in the launch vehicle, which is not limited in the embodiment of the present application.

Preferably, the installation is provided with 4 in the launch vehicle, to ensure a better balance of forces between the fairing 1 and the final stage 3 when they are detached.

In the embodiment of the present application, the elastic member 6 may be a member having elasticity, such as a spring, which is not limited in the embodiment of the present application.

Further, with reference to fig. 1, the device further includes a first fixing member 10 and a second fixing member 11, a first end of the first fixing member 10 is connected to a first end of the sleeve 4, a second end of the first fixing member 10 is used for being connected to an inner circumferential surface of the fairing 1, a first end of the second fixing member 11 is connected to a second end of the sleeve 4, and a second end of the second fixing member 11 is used for being connected to the inner circumferential surface of the fairing 1, so that the sleeve 4 is fixed to the inner circumferential surface of the fairing 1 in an inclined manner, and the purpose that the sleeve does not occupy too much enveloping space in the fairing 1 is achieved.

In the embodiment of the present application, the first end of the first fixing element 10 and the first end of the second fixing element 11 may be fixed to the sleeve 4 by welding, and of course, an integrally formed processing method, a detachable fixing method, and the like may also be adopted, which is not limited in the embodiment of the present application.

Preferably, the first end of the first fixing piece 10 and the first end of the second fixing piece 11 are detachably fixed to the sleeve 4, so that different installation requirements can be met by connecting the first fixing piece 10 and the second fixing piece 11 of different types, the universality of the sleeve 4 is improved, and the production cost is saved.

Further, a through hole can be formed in the first end of the first fixing member 10, a connecting member with the through hole can be arranged at the end portion of the first end of the sleeve 4, the bolt penetrates through the through hole of the first end of the first fixing member 10 and the through hole of the connecting member of the first end of the sleeve 4 to be connected with the nut, the first end of the first fixing member 10 and the first end of the sleeve 4 are fixed through threaded connection, meanwhile, the first end of the second fixing member 11 can be arranged to be a hoop, the first end of the second fixing member 11 is sleeved on the outer peripheral face of the second end of the sleeve 4, and the first end of the second fixing member 11 can be fixed to the second end of the sleeve 4 through locking of the first end of the second fixing member 11.

The second ends of the first fixing member 10 and the second fixing member 11 may be detachably connected to the inner circumferential surface of the cowl 1 by bolts, or may be fixed by welding, which is not limited in the embodiments of the present application.

Preferably, the second end of the first fixing element 10 and the second end of the second fixing element 11 are in bolt connection with the inner circumferential surface of the fairing 1, and bolts are respectively threaded through holes formed in the second end of the first fixing element 10 and the second end of the second fixing element 11 and threaded holes correspondingly formed in the inner circumferential surface of the fairing 1, so that the installation is convenient.

Further, referring to fig. 1, the device further includes a screw 12 and a nut 13, the screw 12 is connected to the first end of the locking rod 7 and passes through the opening of the end of the first end of the sleeve 4, and the nut 13 is connected to the screw 12 in a threaded manner and is disposed outside the sleeve 4, so that the first end of the locking rod 7 is detachably connected to the first end of the sleeve 4.

In this application embodiment, the opening of the tip of sleeve 4 first end and screw rod 12 are clearance fit, through screwing nut 13 and screw rod 12, make elastic component 6 compress to demand length, can realize the fixed of locking lever 7 first end on sleeve 4 first end, after fairing 1 finishes with final stage 3 installation, back is unscrewed nut 13, can unblock the locking lever 7 first end and be connected with sleeve 4 first end, prepare for the separation of follow-up fairing 1.

Further, referring to fig. 1, the device further includes a pressing block 14 having a first end and a second end opposite to each other and disposed in the sleeve 4 with a gap therebetween, the second end of the elastic member 6 and the second end of the locking lever 7 are both connected to the first end of the pressing block 14, and the second end of the pressing block 14 is connected to the first end of the push rod 5, so as to ensure that the push rod 5 performs an axial movement in the sleeve 4.

With reference to fig. 1, the diameter of the opening of the end of the second end of the sleeve 4 is smaller than the diameter of the pressure piece 14, so as to ensure that the push rod 5 can remain inside the sleeve 4 without falling off after the separation of the fairing 1 from the final stage 3.

Referring to fig. 1, a sliding block 15 is disposed at the second end of the push rod 5, two side surfaces of the sliding block 15 may be circular planes, a circumferential surface of the sliding block 15 may be arc-shaped, a circumferential surface of the sliding block 15 is connected to the second end of the push rod 5, two side surfaces of the sliding chute 9 may be planes, a bottom surface of the sliding chute 9 may be arc-shaped, two side surfaces of the sliding block 15 and two side surfaces of the sliding chute 9 are arranged in a gap manner, and a circumferential surface of the sliding block 15 is connected to the bottom surface of the sliding chute 9, so as to better realize the movement of the sliding block 15 in the sliding chute 9.

In addition, the sliding block 15 may also be spherical, and the sliding groove 9 may also be provided as an arc shape in clearance fit with the sliding block 15, which is not limited in the embodiment of the present application.

Further, an included angle between the central axis of the sleeve 4 and the central axis of the fairing 1 is α, an included angle between the length direction of the sliding groove 9 and a plane perpendicular to the central axis of the fairing 1 is θ, and α and θ satisfy a formula μ < tan (α + θ), wherein a friction coefficient between the second end of the push rod 5 and the sliding groove 9 is μ, that is, a friction coefficient between the sliding block 15 and the sliding groove 9 is μ, so as to ensure that the sliding block 15 can move in the sliding groove 9 when the fairing 1 and the final stage 3 are separated.

In the embodiment of the present application, grease is provided between the slider 15 and the sliding slot 9 to reduce the friction coefficient μ and facilitate the movement of the slider 15 in the sliding slot 9.

Further, the size of the sliding chute 9 in the length direction satisfies the formula K is greater than or equal to lssin α/cos θ, where K is the size of the sliding chute 9 in the length direction, and L is the maximum extension length of the push rod 5 to ensure that the push rod 5 is fully extended, and the acting force of the push rod can completely act on the sliding chute 9, that is, the maximum thrust is achieved when the fairing 1 and the final stage 3 are separated fully, so that the fairing 1 and the final stage 3 are prevented from colliding with each other.

In the embodiment of the application, the range of alpha is more than 0 and less than or equal to 20 degrees, so that the device has the best installation mode on the carrier rocket.

Compared with the fairing inclined-pushing axial separation device disclosed in the patent (publication date: 2021, 12.02/12, publication number: CN112357129A), the flat ball head (equivalent to the sliding block 15) is arranged in the groove (different from the sliding groove 9) of the invention), only the rotation of the flat ball head can be realized, the connection between the sleeve (equivalent to the sleeve 4) and the fairing is a hinge connection (the sleeve can rotate during assembly), and the arrangement mode of the separation spring (equivalent to the elastic piece 6) leads to certain inconvenience and difficulty in installation when the fairing (equivalent to the fairing 1) is assembled on the final stage (equivalent to the final stage 3) of the invention.

In conclusion, the carrier rocket provided with the fairing axial separation device can avoid the fairing from colliding with the effective load during separation, the installation mode of the device fully utilizes the space structure, does not occupy excessive enveloping space of the fairing, is convenient for assembly between the fairing and the final stage, and has good practicability, novelty and creativity.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be considered as limiting the present invention.

It should be noted that all the directional indications in the embodiments of the present invention are only used to explain the relative position relationship, the motion situation, and the like between the components in a certain posture, and if the certain posture is changed, the directional indication is changed accordingly.

In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.