阅读说明：本技术 一种城市道路绿化结构 (Urban road greening structure ) 是由 不公告发明人 于 2019-10-17 设计创作，主要内容包括：一种城市道路绿化结构,属于市政工程领域。绿化结构包括导水沟、立柱、缓冲器。其中,导水沟包括盖板、沟底以及相对布置的第一沟壁和第二沟壁。立柱包括竖直地固定于第一沟壁和第二沟壁的第一柱体和第二柱体。缓冲器包括支撑体、两个防护板,支撑体的两端分别与两个防护板连接,两个防护板还分别与第一柱体、第二柱体连接。支撑体具有弹性两个防护板中的每一个具有波浪形的防撞面,且防撞面的波峰和波谷在道路的长度方向交替出现并延伸至道路的全长。绿化结构被用于道路以减轻车辆冲击或撞击绿化带时产生的损害。(An urban road greening structure belongs to the field of municipal engineering. The greening structure comprises a water guiding ditch, an upright post and a buffer. The water guide ditch comprises a cover plate, a ditch bottom, a first ditch wall and a second ditch wall which are oppositely arranged. The upright includes first and second columns vertically fixed to the first and second channel walls. The buffer comprises a supporting body and two protection plates, wherein two ends of the supporting body are respectively connected with the two protection plates, and the two protection plates are respectively connected with the first cylinder and the second cylinder. The supporting body is provided with two elastic protective plates, each of the two protective plates is provided with a wavy anti-collision surface, and wave crests and wave troughs of the anti-collision surfaces alternately appear in the length direction of the road and extend to the full length of the road. Green structures are used on roads to mitigate damage that occurs when a vehicle impacts or hits a green belt.)

1. An urban road greening structure, is arranged and is located the road middle part along the length direction of road in order to separate two lanes, its characterized in that, greening structure includes:

the water guide ditch comprises a cover plate, a ditch bottom and a first ditch wall and a second ditch wall which are oppositely arranged, wherein the cover plate is detachably paved on the first ditch wall and the first ditch wall, and the ditch bottom is connected between the first ditch wall and the second ditch wall to jointly limit the water guide channel;

the upright post comprises a first post body and a second post body, the first post body is formed by extending from a first root part to a first top part, the second post body is formed by extending from a second root part to a second top part, and the first post body and the second post body are vertically fixed on the first trench wall and the second trench wall respectively in a corresponding mode through the first root part and the second root part;

the buffer comprises a supporting body and two protection plates, wherein two ends of the supporting body are respectively connected with the two protection plates, and the two protection plates are also respectively connected with the first top of the first column body and the second top of the second column body;

the supporting body has elasticity, each of the two protective plates is provided with a wavy anti-collision surface, and wave crests and wave troughs of the anti-collision surfaces alternately appear in the length direction of the road and extend to the full length of the road;

the stop table comprises a base body and two arc-shaped parts combined on the two sides of the base body in the width direction of the road, the arc-shaped parts are provided with concave surfaces sunken from a lane to a greening structure, the sunken depths of the concave surfaces at the positions adjacent to the road surface are greater than the sunken depths at the positions far away from the road surface, the concave surfaces are connected with bearing pieces at two ends in the vertical direction, each bearing piece comprises a plurality of connecting blocks, and the two adjacent connecting blocks are hinged.

2. The urban road greening structure of claim 1, wherein the peaks and valleys of the impact-resistant surface are smoothly transitioned.

3. The urban road greening structure of claim 2, wherein the ratio of the wavelength to the amplitude of the impact surface is 10 to 20.

4. The urban road greening structure of any one of claims 1 to 3, wherein the supporting body has two distal sections adjacent to the two protection plates, one proximal section remote from the two protection plates and located between the two distal sections, each of the two distal sections having a greater coefficient of elasticity than the proximal section.

5. Urban road greening structure according to claim 4, wherein said support body is a variable diameter spring defining a section perpendicular to the axis, the projected area of each of said two distal sections in said section being greater than the projected area of said proximal section in said section.

6. The urban road greening structure of claim 5, wherein the variable diameter spring is internally wrapped with a rubber ball.

7. The urban road greening structure of claim 1, wherein the bumper further comprises a wavy back plate, the back plate is combined on one surface of the protection plate, which faces away from the collision-prevention surface, the peak area of the back plate corresponds to the valley area of the protection plate, and the valley area of the back plate corresponds to the peak area of the protection plate.

8. The urban road greening structure of claim 1, wherein the protection plate has a first side edge and a second side edge distributed in a vertical direction, the height of the first side edge relative to the road surface is greater than the height of the second side edge relative to the road surface, the first side edge defines a first projection on the road surface, and the second side edge defines a second projection on the road surface;

the protection plate is arranged obliquely in a vertical direction and is defined as: the first projection is far away from the middle of the road and the second projection is close to the middle of the road along the width direction of the road.

9. The urban road greening structure of claim 1, wherein the first column and the second column are both curved.

10. The urban road greening structure of claim 9, wherein the curved portions of the first column and the second column are both far from the ground.

Technical Field

The invention relates to the field of municipal engineering, in particular to an urban road greening structure.

Background

Road-greening structures are usually in the form of isolation or green belts. It has the functions of beautifying road, eliminating noise, relieving visual fatigue, blocking dust, etc. and thus has important function in planning and building city road. Although the greening structure has a certain role in the above aspects, the role in the safety function of the greening structure is still to be explored to increase and improve the application value of the greening structure.

Disclosure of Invention

Based on the defects of the prior art, the invention provides an urban road greening structure, and solves the problem that the safety effect of the existing road greening structure is not good enough.

The invention is realized by the following steps:

an urban road greening structure is arranged along the length direction of a road and is positioned in the middle of the road to separate two lanes.

The greening structure comprises:

the water guide ditch with the water delivery channel comprises a cover plate, a ditch bottom and a first ditch wall and a second ditch wall which are oppositely arranged, wherein the cover plate is detachably paved on the first ditch wall and the ditch wall, and the ditch bottom is connected between the first ditch wall and the second ditch wall to jointly limit the water delivery channel;

the upright post comprises a first post body and a second post body, the first post body is formed by extending from a first root part to a first top part, the second post body is formed by extending from a second root part to a second top part, and the first post body and the second post body are vertically fixed on the first trench wall and the second trench wall respectively in a corresponding mode through the first root part and the second root part;

the buffer comprises a supporting body and two protection plates, wherein two ends of the supporting body are respectively connected with the two protection plates, and the two protection plates are also respectively connected with the first top of the first column body and the second top of the second column body;

the supporting body has elasticity, each of the two protective plates is provided with a wavy anti-collision surface, and wave crests and wave troughs of the anti-collision surfaces alternately appear in the length direction of the road and extend to the full length of the road;

the stop table comprises a base body, two arc-shaped parts combined on the base body along the two sides of the road width direction, the arc-shaped parts are provided with concave surfaces sunken from a lane to a greening structure, the sunken depth of the concave surfaces at the positions adjacent to the road surface is greater than the sunken depth of the concave surfaces at the positions far away from the road surface, the concave surfaces are connected with bearing parts at the two ends of the vertical direction, each bearing part comprises a plurality of connecting blocks, and the two adjacent connecting blocks are hinged.

Optionally, the bump surface has smooth transitions between peaks and valleys.

Optionally, the ratio of the wavelength to the amplitude of the impact surface is 10 to 20.

Optionally, the support body has two distal sections adjacent to the two guard plates, one proximal section remote from and between the two distal sections, each of the two distal sections having a greater coefficient of elasticity than the proximal section.

Optionally, the support is a variable diameter spring defining a cross-section perpendicular to the axis, the projected area of each of the two distal segments in the cross-section being greater than the projected area of the proximal segment in the cross-section.

Optionally, the variable diameter spring is internally wrapped with a rubber ball.

Optionally, the bumper further comprises a wavy back plate, the back plate is combined on one surface of the protection plate, which is away from the anti-collision surface, the wave crest area of the back plate corresponds to the wave trough area of the protection plate, and the wave trough area of the back plate corresponds to the wave crest area of the protection plate.

Optionally, the protection plate has a first side edge and a second side edge distributed in a vertical direction, the height of the first side edge relative to the road surface is greater than that of the second side edge relative to the road surface, the first side edge is defined to form a first projection on the road surface, and the second side edge is defined to form a second projection on the road surface;

the protection plate is arranged obliquely in the vertical direction and is defined as: along the width direction of the road, the first projection is far away from the middle of the road, and the second projection is close to the middle of the road.

Optionally, the first and second cylinders are both curved.

Optionally, the curved portions of the first and second columns are both remote from the ground.

Has the advantages that:

the urban road greening structure provided by the invention can be integrated into the existing greening structure as a whole, and the existing road is not changed too much, so that the urban road greening structure is beneficial to implementation and the construction workload is reduced. In terms of protecting vehicles traveling on a road, the green structure is valuable at least in reducing impact injuries when the vehicle impacts a green belt. The road greening structure can buffer the impact of vehicles, so that severe impact can not occur. In particular, it achieves unloading of the large loads generated in the event of a vehicle impact by means of a damping action, so that the vehicle is correspondingly subjected to a smaller counter force. Wherein, the deformation of guard plate, stand has all played the cushioning effect. And the buffer plate is directly contacted with the vehicle in advance, and plays a role in buffering through self deformation, and the secondary buffering is realized through the complementary deformation generated by the upright column along with the limit reached by the deformation of the buffer plate. In addition, since the fender has a curved surface in a wave shape, it can guide and change the direction of the acting force of the vehicle, thereby making it possible to avoid the occurrence of direct collision. That is, the curved surface of the shield can guide the vehicle to change direction of motion rather than directly causing it to be intercepted and severely slowed down (severe slowing may result in a large impact force failing and thereby causing impact injury).

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of a road on which a greening structure is provided according to an embodiment of the present invention;

FIG. 2 is a schematic view of the greening structure provided by the embodiment of the present invention and the road shown in FIG. 1;

FIG. 3 is a schematic cross-sectional view of a protection plate in a greening structure according to an embodiment of the present invention;

FIG. 4 is a schematic view of a protection plate in a greening structure according to an embodiment of the present invention;

FIG. 5 is a schematic view of a support body in a greening structure provided by an embodiment of the present invention;

FIG. 6 is a schematic view of a gutter in a greening structure according to an embodiment of the present invention;

FIG. 7 is a schematic view of a stopping table in a greening structure provided by an embodiment of the present invention at a first viewing angle (excluding a bearing member);

FIG. 8 is a schematic view of a stopping table in a greening structure according to an embodiment of the present invention at a second viewing angle;

fig. 9 is a schematic view of a carrier in a greening structure according to an embodiment of the present invention.

Icon:

101-a first lane; 102-a second lane;

201-a first cylinder; 202-a second cylinder; 203-a support; 204-protective plate;

301-trough; 302-wave peak; 303-a first side edge; 304-a second lateral edge;

400-variable diameter spring; 401-proximal segment; 402-a distal segment;

500-a gutter; 501-trench bottom; 502-a first sidewall; 503-a second side wall; 504-water delivery channel; 505-a cover plate;

600-a stop table; 601-a substrate; 602-an arc; 603-concave surface; 604-a carrier; 605-connecting block; 606-articulated shaft.

Detailed Description

See fig. 1-4.

The urban road greening structure (hereinafter referred to as greening structure) mainly comprises an anti-collision structure, and does not relate to plants, decorations and the like. However, such auxiliary objects may also be designed as desired based on actual needs and are not specifically and further elaborated on in the present invention.

Before describing the solution of the invention, for a clearer explanation, the road is described as follows, with reference to fig. 1. The road defines a length direction a and a width direction B. The road has two lanes (e.g., a first lane 101 and a second lane 102) in two directions (opposite) separated by a green structure. The width direction may thus be defined as the direction of the first lane 101 to the second lane 102. Accordingly, the middle of the road may be where the green structure is located, while the first lane 101 and the second lane 102 are located on both sides of the road. The first lane 101 has an inner side which is a portion close to the greening structure and an outer side which is a portion far from the greening structure (curb portion/curb, curb); similarly, the second lane 102 has an inner side which is a portion close to the greening structure and an outer side which is a portion far from the greening structure (curb portion/curb, curb).

Thereby, the environment to which the greening structure is attached is clearly illustrated and defined, and the following detailed structure of the greening structure is clearly defined and illustrated based on the aforementioned roads.

In general, the greening structure mainly includes three parts of a gutter 500, a pillar, and a bumper. The gutter 500 is a foundation of a greening structure, and other pillars, dampers, and specific components thereof are arranged depending on the gutter 500. While the posts and bumpers mainly serve a supporting and cushioning function. The various parts of the greening structure in the example will be explained in more detail below with reference to the drawings. The relative position of the road and the green structure is given and disclosed by the diagram shown in fig. 2.

The structure of the water chute 500 is shown in fig. 6.

As the name implies, the gutter 500 is a structure for guiding and transporting water. Generally, it can be made of reinforced cement in the construction industry, or be built up of bricks or stones. Or it is assembled and welded by steel. In general, the gutter 500 is a tubular structure as a whole, and is arranged along the length direction of the road (which may be curved or straight, depending on the road). In a specific embodiment, the gutter 500 includes a cover 505, a gutter bottom 501, a first gutter wall, and a second gutter wall. The end surface of the gutter 500 thus formed is square (rectangular, square, etc.). The water channeling 500 is installed/buried in the ground as a base capable of providing a stable supporting force and resisting the influence of external impact, crushing, etc. In other words, the road is previously dug with a three-sided square groove from the ground. The structures constituting the gutter 500 are then installed and fixed in the gutter. Specifically for the present embodiment, the trench bottom 501 is laid on the bottom in the trench, and then the first trench wall and the second trench wall are laid on both sides (in the width direction of the road) of the trench bottom 501. The trench bottom 501 and the trench wall may be cemented or welded or bolted, and may have different expressions according to the implementation form of the water guiding trench 500. After that, a cover plate 505 is covered over the first trench wall and the second trench wall. The cover plate 505 may be a fixed cover or a removable cover. In a preferred embodiment, the cover 505 is detachably arranged so that no cleaning or required operations can be performed inside the raceway 500 (i.e. the water channel 504, which is formed and defined by the cover 505, the raceway bottom 501, the first raceway wall and the second raceway wall). The cover plate 505 may be in the form of a grid (e.g., a metal grid), or a steel plate, etc. The inside of the gutter 500 may be defined as a path for transporting water, but it is not limited to only transporting water. For example, various electric devices or power supply circuits may be provided inside the gutter 500, such as the side walls (the first and second gutter walls) to supply electric power to a street lamp, a monitor, and the like.

Referring to fig. 7, 8 and 9, the greening structure is further provided with stopping platforms at the outer sides of both ends of the water guiding gutter (i.e., both sides of the road in the width direction B). The stopper platform is an external structure of the greening structure, and is used as a stopper when the vehicle accidentally contacts the greening structure. The stopper table includes a base body and an arc portion.

Wherein the base is the main body portion of the stopper table, as shown in fig. 7, which provides the entire structural strength of the stopper table and resistance to the outside. The arc-shaped parts are combined on two sides of the base body and are used as main (contact with a vehicle) stress parts.

As shown in fig. 7 and 8, the arcuate portion is a concave structure. It is recessed inwardly with respect to the base, specifically from the lanes on both sides of the road to the green structure (isolation zone/green zone) in the middle of the road. As a specific way of recessing, the stop table is defined as follows: the concave surface has a greater depth of concavity adjacent the road surface than at a distance from the road surface. Thus, the thickness of the stop table in the portion adjacent to the road surface is relatively smaller and the thickness of the stop table in the portion away from the road surface is relatively larger as a whole. The concave surface is connected with the bearing piece at two ends in the vertical direction.

Referring to fig. 9, the carrier includes a plurality of connecting blocks, and two adjacent connecting blocks are hinged to each other. The bearing piece formed by hinging a plurality of connecting blocks can adjust (rotate) the shape under the action of impact force, so that the orientation or the movement direction of a vehicle can be changed to a certain degree, and meanwhile, the bearing piece can also relieve the reaction force of the impact through deformation. The arc-shaped part of the stopping table forms a concave space which can be used as an accommodating space for deformation of the bearing piece, so that the bearing piece is allowed to protrude into the concave space when deformed. Therefore, the stop table, the bearing piece and the buffer are matched with each other, and a better anti-collision effect can be achieved. Further, an elastic layer is arranged in the concave space of the stop table. The elastic layer is bonded to the concave surface. The elastic layer can prevent the bearing part from colliding with the surface of the arc-shaped part, and meanwhile, the vibration reduction effect is achieved. Further, since the both sides of the arc-shaped portion of the stopper body are different in extension distance in the horizontal direction, the carriers connected to both ends of the arc-shaped portion are obliquely arranged. The bearing part also has a certain guiding function on the vehicle, and the bearing part bears force on the part close to the ground and the part far away from the ground, so that the vehicle is more easily restrained from moving, the mechanical damage of the bearing part is favorably reduced, and the service life of the bearing part is improved.

Upright post

In the example shown in the above, the first,the column comprises two parts, a first cylinder 201 and a second cylinder 202. The two bodies correspond to both sides of the green belt in the width direction of the road, respectively. I.e. one column adjacent to a first lane and the other body adjacent to a second lane. The two bodies are linked and supported by a linking structure to be mentioned later so as to provide corresponding assistance against impact force with each other.

The two bodies have the same or substantially the same structure without substantial difference, thereby reducing the difficulty of fabrication. The first column 201 is formed by extending from a first root to a first top. The length of the first cylinder 201 is substantially equal to the distance between the first root and the first crest. The length of the first cylinder 201 may also be considered the height of the first cylinder 201 in terms of its particular manner of use. Accordingly, the second post 202 also has corresponding structural features, and for the sake of brevity, the description of the second post 202 is simply provided by extending from the second root to the second top for avoiding redundant description.

In the present invention, the first column 201 and the second column 202 are vertically fixed to the first trench wall and the second trench wall with the first root and the second root, respectively, corresponding to each other. That is, the first cylinder 201 is maintained upright and stable in the upright state by being fixed (inserted/welded) at the first root of the first trench wall. Likewise, the second cylinder 202 is kept upright and stable in the upright state by being fixed (inserted/welded) at the second root portion of the second trench wall. Furthermore, given that the green structure serves to provide cushioning, and thus a cushioning effect for movement of the vehicle, it is apparent that the upright is desired to be stable and strong. On the one hand, this can be achieved by making the stud have a considerable portion embedded in the first trench wall, i.e. the first root has a greater length. On the other hand, it is also possible to make the first root portion have a relatively large thickness.

The foregoing illustrates the arrangement of the posts, and the specific construction of the posts is described herein. The columns can be used in various configurations such as prismatic or cylindrical or elliptical columns, and can be selected as desired. In the above type of upright, it may be straight or curved. For curved uprights, it may be desirable for the curved portions to be all remote from the ground. Or, further, the upright post can be solid or hollow. Although illustrated as hollow, it may also provide sufficient structural strength and stability by having a suitable wall thickness. For hollow structures, it may be an outer metal material wrapped around an inner resilient or flexible material (e.g., a plastic or rubber bar, etc.).

Buffer (connecting structure)

The bumper is generally the portion that was previously in contact with the impacting vehicle as compared to other portions of the green structure. The bumper mainly comprises a supporting body 203 and two protection plates 204. The two protection plates 204 and the support body 203 are supported as a whole by the column to be fixed in an approximately lifted manner, and specifically, the two protection plates 204 are further connected to a first top portion of the first column 201 and a second top portion of the second column 202, respectively. Inside the bumper, two ends of the supporting body 203 are connected to two protection plates 204, respectively.

Wherein the support 203 has elasticity. Functionally, the constraint is provided on the one hand so that the two guard plates 204 cannot be easily separated from each other and cannot be easily brought close to each other. Therefore, the support body 203 is firmly connected with the two guard plates 204 while having appropriate structural strength. As far as its elasticity is concerned, it may have the same or substantially the same elasticity throughout the respective portions in the longitudinal direction. As a modification, the elasticity of the support 203 is different in different portions. For example, referring to fig. 5, which shows a partial structure of the support body 203 (one distal segment 402 and one proximal segment 401), the support body 203 has two distal segments 402 adjacent to the two guard plates 204, and one proximal segment 401 distal to the two guard plates 204 and located between the two distal segments 402. And, the elastic modulus of each of the two distal segments 402 is greater than the elastic modulus of the proximal segment 401. This can be achieved by varying the thickness and material of the different parts of the support 203.

As an example, the supporting body 203 may be made of an elastic rod or an elastic block. The support 203 in the present example employs a spring. Further, the supporting body 203 is a variable diameter spring 400. The spring defines a cross-section perpendicular to the axis, the projected area of each of the two distal sections 402 of the support body 203 in the cross-section being greater than the projected area of the proximal section 401 of the support body 203 in the cross-section. Thus, if the spring is made of the same material, the variable diameter of the spring can realize different elastic coefficients of different parts and provide different supporting acting forces. In addition, since the supporting body 203 has a spring structure, it has an axially distributed space. Thus, the variable diameter spring is internally wrapped with a rubber ball to provide better cushioning and unloading of impacts.

The two protection plates 204 are of the same structure, and can be connected and fixed with the support body 203 by welding or bolt connection. Preferably, the guard plate 204 is a wave-shaped structure, see fig. 3 and 4. The shielding plate 204 may have a wave shape on one surface in the thickness direction and a plane shape on the other surface in consideration of convenience of connection with the supporting body 203. Or both surfaces thereof are undulated from the viewpoint of ease of fabrication. Such a guard plate 204 may be formed directly from, for example, a steel plate by stamping or pressing. The cross section of the guard plate 204 with the undulating surface forms an undulating surface. For clarity of description of the arrangement, the wavy surface of the fender 204 is defined as the bump surface. The wave crests 302 and wave troughs 301 of the impact surface alternate in the length direction of the road and extend to the full length of the road. In other words, the extending direction E of the impact surface coincides with the longitudinal direction of the road. The peaks 302 and the valleys 301 alternate in the direction of elongation of the impact surface.

Although the wavy guard plate 204 may function as an impact protection, it is verified that if the collision-preventing surface of the guard plate 204 is arranged in the following manner, the collision-preventing effect is not the same as that described above. The following way is: the peaks 302 and valleys 301 of the impact surface alternate in the vertical direction of the road (the height direction of the post).

Due to the wavy structure design, the protective plate 204 can change the direction of the vehicle which collides against the protective plate to a certain extent, so that the vehicle cannot be severely decelerated, and can be gradually decelerated through proper direction change, sliding and collision until the vehicle stops. Meanwhile, the protection plate 204 with such a structure can also absorb impact energy well by changing its shape.

In addition, as a modified scheme, the wave crests 302 and the wave troughs 301 of the collision avoidance surface are smoothly transited, so that a more gentle surface can be provided. As a more preferred option, the ratio of the wavelength C to the amplitude D (wavelength/amplitude ratio, defined as smoothness) of the impact surface is 10 to 20. If the smoothness is too great, the effect on the redirection of the vehicle is not strong, and if the smoothness is too small, it may appear too sharp, and puncture injuries or local force over concentration are likely to occur.

In addition, the improved buffer can be provided with a wavy back plate according to requirements. The back panel is bonded to a surface of the fender panel 204 facing away from the impact surface. And the peak 302 area of the back plate corresponds to the valley 301 area of the guard plate 204, and the valley 301 area of the back plate corresponds to the peak 302 area of the guard plate 204. Thus, when the vehicle comes into contact with a frontal collision, the vehicle and the backboard are located on both sides of the fender 204, respectively. Wherein the guard plate 204 and the back plate together provide support and cushioning.

While the structure of the guard plate 204 is described above, an alternative preferred arrangement is provided below to illustrate the arrangement of the guard plate 204 based on the undulating structure described above. The guard plate 204 has a first side edge 303 and a second side edge 304 (shown in fig. 4) that are distributed in the vertical direction (height direction G). Wherein the height of the first side edge 303 relative to the road surface is greater than the height of the second side edge 304 relative to the road surface.

The first side edge 303 defines a first projection onto the road surface and the second side edge 304 defines a second projection onto the road surface. The shielding plate 204 is arranged inclined in the vertical direction and is defined as: along the width direction of the road, the first projection is far away from the middle of the road, and the second projection is close to the middle of the road. Thus, the guard plate 204 is inclined from the widthwise end view of the road, and is inclined from the road edge to the central portion of the road. In this manner, the fender 204 may inhibit the tendency of the vehicle to bump or tilt up to some extent, thereby providing the possibility of avoiding it from rushing out of the green belt to the opposite lane.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.