阅读说明：本技术 一种能够自动调整迎风受力面的风力发电叶轮 (Wind power generation impeller capable of automatically adjusting windward stress surface ) 是由 钟小燕 于 2021-09-13 设计创作，主要内容包括：本发明涉及风力发电的技术领域,特别是涉及一种能够自动调整迎风受力面的风力发电叶轮,其使风力发电叶轮的迎风受力面积能够随风力自动调节,提升风力发电机的发电效率；包括：轴管,轴管内部安装有风力感应装置,轴管的外壁上设置有传动装置；套管,套管同轴转动安装在轴管上,套管的圆周外壁上固定安装有第一半壳,套管的圆周外壁上安装有第二半壳,第一半壳上固定设置有第一叶片,第二半壳上固定设置有第二叶片,第一半壳和第二半壳之间安装有调节装置,调节装置用于在无外力作用下,使第一叶片和第二叶片重合；其中,风力感应装置用于根据风力大小,通过传动装置来驱动调节装置使第一叶片和第二叶片错位。(The invention relates to the technical field of wind power generation, in particular to a wind power generation impeller capable of automatically adjusting a windward stress surface, which enables the windward stress area of the wind power generation impeller to be automatically adjusted along with wind power and improves the power generation efficiency of a wind power generator; the method comprises the following steps: the wind power induction device is arranged in the shaft tube, and the transmission device is arranged on the outer wall of the shaft tube; the sleeve is coaxially and rotatably arranged on the shaft tube, a first half shell is fixedly arranged on the circumferential outer wall of the sleeve, a second half shell is arranged on the circumferential outer wall of the sleeve, a first blade is fixedly arranged on the first half shell, a second blade is fixedly arranged on the second half shell, an adjusting device is arranged between the first half shell and the second half shell, and the adjusting device is used for enabling the first blade and the second blade to be overlapped under the action of no external force; the wind power induction device is used for driving the adjusting device through the transmission device according to the wind power so as to enable the first blade and the second blade to be staggered.)

1. A wind power generation impeller capable of automatically adjusting a windward force-bearing surface is characterized by comprising:

the wind power generation device comprises a shaft tube (1), wherein a wind power induction device is installed inside the shaft tube (1), and a transmission device is arranged on the outer wall of the shaft tube (1);

the shaft tube (2), the coaxial rotation of sleeve pipe (2) is installed on central siphon (1), fixed mounting has first half shell (3) on the circumference outer wall of sleeve pipe (2), install half second shell (5) on the circumference outer wall of sleeve pipe (2), fixed being provided with first blade (4) on half first shell (3), fixed being provided with second blade (6) on half second shell (5), install adjusting device between half first shell (3) and half second shell (5), adjusting device is used for under no exogenic action, makes first blade (4) and second blade (6) coincide;

the wind power induction device is used for driving the adjusting device through the transmission device according to the wind power so as to enable the first blade (4) and the second blade (6) to be staggered.

2. The wind power generation impeller capable of automatically adjusting a windward force bearing surface according to claim 1, wherein the adjusting device comprises a plurality of groups of connecting rods (8) and first springs (9), universal joints (7) are arranged at two ends of each connecting rod (8), the connecting rods (8) are obliquely arranged between the inner end of the first half shell (3) and the inner end of the second half shell (5) through the universal joints (7), and the groups of connecting rods (8) are arranged in a circumferential array by taking the axis of the sleeve (2) as an axis;

the outside at sleeve pipe (2) is established to first spring (9) cover, and first spring (9) and a plurality of groups connecting rod (8) contactless all the time, the both ends of first spring (9) are connected with first half shell (3) inner and second half shell (5) inner rotation respectively.

3. The wind power generation impeller capable of automatically adjusting the windward force bearing surface according to claim 2, wherein the transmission device comprises a connecting sleeve ring (10) slidably mounted on the shaft tube (1) and a push ring (12) slidably mounted on the shaft tube (1), a plurality of groups of support rods (11) are fixedly arranged between the connecting sleeve ring (10) and the push ring (12), the push ring (12) is used for pushing the second half shell (5) to approach the first half shell (3) against the elastic force of the first spring (9), and the connecting sleeve ring (10) is used for linking with the wind sensing device.

4. The wind power generation impeller capable of automatically adjusting the windward force bearing surface according to claim 3, wherein the wind sensing device comprises two sets of wire guide wheels (14), two sets of connecting ropes (15), a top rod (17) and a force bearing plate (20), two sets of installation grooves (13) are symmetrically arranged on the outer wall of the shaft tube (1) in a penetrating manner, the two sets of wire guide wheels (14) are respectively rotatably installed inside the two sets of installation grooves (13), the axes of the two sets of wire guide wheels (14) are perpendicular to the axis of the shaft tube (1), and the two sets of connecting ropes (15) are respectively lapped around the two sets of wire guide wheels (14);

a supporting plate (18) is fixedly arranged in the shaft tube (1), the ejector rod (17) movably penetrates through the supporting plate (18), the axis of the ejector rod (17) is parallel to the axis of the shaft tube (1), a connecting rod (16) is fixedly arranged at one end, close to the connecting lantern ring (10), of the ejector rod (17), one ends, located outside the shaft tube (1), of the two groups of connecting ropes (15) are fixedly connected with the connecting lantern ring (10), and one ends, located inside the shaft tube (1), of the two groups of connecting ropes (15) are fixedly connected with two ends of the connecting rod (16) respectively;

the other end of the ejector rod (17) is coaxially and fixedly provided with a stress plate (20), a second spring (19) is sleeved on the ejector rod (17), and the second spring (19) is located between the stress plate (20) and the supporting plate (18).

5. A wind power impeller capable of automatically adjusting the force-bearing surface facing the wind according to claim 4, characterized in that the end of the shaft tube (1) remote from the attachment collar (10) is coaxially provided with an amplifying tube (21), the force-bearing plate (20) is located inside the amplifying tube (21), the diameter of the amplifying tube (21) is larger than the diameter of the shaft tube (1), and the diameter of the amplifying tube (21) is smaller than the diameter of the first half-shell (3);

and a positioning device (22) is arranged on the outer wall of the stress plate (20) and used for manually adjusting the windward stress area of the impeller.

6. The wind power generation impeller capable of automatically adjusting the windward force bearing surface according to claim 3, wherein a plurality of groups of first guide grooves (23) are arranged on the outer wall of the shaft tube (1), a plurality of groups of protrusions (24) are arranged on the inner wall of the connection sleeve ring (10) corresponding to the plurality of groups of first guide grooves (23), and the plurality of groups of first guide grooves (23) are respectively slidably mounted inside the plurality of groups of protrusions (24).

7. The wind power generation impeller capable of automatically adjusting the windward force-bearing surface according to claim 5, wherein the positioning device (22) comprises a boss (25) and a sliding block (27) which are fixedly arranged on the amplifying tube (21), the boss (25) is provided with a strip-shaped groove (26) which penetrates through the amplifying tube (21), and the extension line of the strip-shaped groove (26) is parallel to the axis of the amplifying tube (21);

the slide block (27) is slidably mounted inside the strip-shaped groove (26), one end, located inside the amplifying tube (21), of the slide block (27) is fixedly connected with the side wall of the stress plate (20), a mounting hole (28) is formed in the other end of the slide block (27), a third spring (29) is mounted inside the mounting hole (28), a connecting disc (30) is rotatably mounted at one end, far away from the stress plate (20), of the third spring (29), two groups of side arms (31) are symmetrically and fixedly arranged on the side wall of the connecting disc (30), two groups of clamping grooves (32) for clamping the side arms (31) are formed in the slide block (27), and limiting columns (33) are arranged on the two groups of side arms (31);

the boss (25) is symmetrically provided with a plurality of groups of limiting holes (34) at two sides of the strip-shaped groove (26) and used for clamping limiting columns (33) on the side arms (31); and a pull rod (35) is fixedly arranged on the connecting disc (30).

8. The wind power generation impeller capable of automatically adjusting the windward force bearing surface according to claim 2, wherein the sleeve (2) is provided with a second guide groove (36) on the outer circumferential wall, and the second half shell (5) is provided with a spherical sliding block corresponding to the second guide groove (36), and the spherical sliding block is slidably mounted inside the strip-shaped groove (26).

Technical Field

The invention relates to the technical field of wind power generation, in particular to a wind power generation impeller capable of automatically adjusting a windward force bearing surface.

Background

The kinetic energy of wind is converted into mechanical kinetic energy, and then the mechanical energy is converted into electric kinetic energy, namely wind power generation. The principle of wind power generation is that wind power drives windmill blades to rotate, and then the rotating speed is increased through a speed increaser, so that a generator is promoted to generate electricity. According to the windmill technology, the breeze speed of about three meters per second can start to generate electricity; wind power generation is forming a hot tide in the world because it does not require the use of fuel and does not produce radiation or air pollution.

In the use process of the small wind driven generator, the windward stress area of the power generation impeller can influence the power generation efficiency of the generator to a great extent, and the windward stress area of the power generation impeller of the existing small wind driven generator is fixed, so that automatic adjustment can not be carried out according to wind power, and the power generation efficiency of the generator is lower.

Disclosure of Invention

In order to solve the technical problems, the invention provides the wind power generation impeller which can automatically adjust the windward stress surface, enables the windward stress area of the wind power generation impeller to be automatically adjusted along with the wind power, and improves the power generation efficiency of the wind power generator.

The invention relates to a wind power generation impeller capable of automatically adjusting a windward force bearing surface, which comprises:

the wind power induction device is arranged in the shaft tube, and the transmission device is arranged on the outer wall of the shaft tube;

the coaxial rotating shaft comprises a sleeve, a first half shell, a second half shell, a first blade, a second blade, an adjusting device and a second rotating shaft, wherein the sleeve is coaxially and rotatably installed on a shaft tube, the first half shell is fixedly installed on the circumferential outer wall of the sleeve, the second half shell is installed on the circumferential outer wall of the sleeve, the first half shell is fixedly provided with the first blade, the second half shell is fixedly provided with the second blade, the adjusting device is installed between the first half shell and the second half shell, and the adjusting device is used for enabling the first blade and the second blade to coincide under the action of no external force;

the wind power induction device is used for driving the adjusting device through the transmission device according to the wind power so as to enable the first blade and the second blade to be staggered.

Furthermore, the adjusting device comprises a plurality of groups of connecting rods and a first spring, universal joints are arranged at two ends of each connecting rod, the connecting rods are obliquely arranged between the inner ends of the first half shell and the second half shell through the universal joints, and the plurality of groups of connecting rods are in a circumferential array by taking the axis of the sleeve as a shaft;

the first spring sleeve is arranged outside the sleeve, the first spring is always in contactless with the plurality of groups of connecting rods, and two ends of the first spring are respectively in rotating connection with the inner end of the first half shell and the inner end of the second half shell.

Further, transmission includes the connection lantern ring of slidable mounting on the central siphon and slidable mounting push ring on the central siphon, it is provided with a plurality of groups bracing piece to connect fixedly between lantern ring and the push ring, the push ring is used for promoting half shell of second and overcomes first spring elasticity and is close to half shell, the connection lantern ring is used for linking with wind-force induction system.

Furthermore, the wind power induction device comprises two groups of wire guide wheels, two groups of connecting ropes, a top rod and a stress plate, wherein two groups of mounting grooves are symmetrically arranged on the outer wall of the shaft tube in a penetrating manner, the two groups of wire guide wheels are respectively rotatably mounted inside the two groups of mounting grooves, the axes of the two groups of wire guide wheels are vertical to the axis of the shaft tube, and the two groups of connecting ropes are respectively lapped on the two groups of wire guide wheels;

a supporting plate is fixedly arranged in the shaft tube, the ejector rod movably penetrates through the supporting plate, the axis of the ejector rod is parallel to the axis of the shaft tube, a connecting rod is fixedly arranged at one end, close to the connecting lantern ring, of the ejector rod, one ends, located outside the shaft tube, of the two groups of connecting ropes are fixedly connected with the connecting lantern ring, and one ends, located inside the shaft tube, of the two groups of connecting ropes are fixedly connected with the two ends of the connecting rod respectively;

the other end of the ejector rod is coaxially and fixedly provided with a stress plate, a second spring is sleeved on the ejector rod and is positioned between the stress plate and the supporting plate.

Further, an amplifying tube is coaxially arranged at one end, away from the connecting sleeve ring, of the shaft tube, the stress plate is located inside the amplifying tube, the diameter of the amplifying tube is larger than that of the shaft tube, and the diameter of the amplifying tube is smaller than that of the first half shell;

and a positioning device is arranged on the outer wall of the stress plate and used for manually adjusting the windward stress area of the impeller.

Further, be provided with the first guide way of a plurality of groups on the outer wall of central siphon, it is provided with a plurality of groups archs, a plurality of groups to correspond the first guide way of a plurality of groups on the inner wall of the connection lantern ring first guide way slidable mounting has a plurality of protruding insides of group respectively.

Furthermore, the positioning device comprises a boss and a sliding block which are fixedly arranged on the amplifying tube, a strip-shaped groove which penetrates through the amplifying tube is arranged on the boss, and the extension line of the strip-shaped groove is parallel to the axis of the amplifying tube;

the slide block is slidably mounted in the strip-shaped groove, one end, located inside the amplifying tube, of the slide block is fixedly connected with the side wall of the stress plate, the other end of the slide block is provided with a mounting hole, a third spring is mounted in the mounting hole, one end, far away from the stress plate, of the third spring is rotatably mounted with a connecting disc, two groups of side arms are symmetrically and fixedly arranged on the side wall of the connecting disc, two groups of clamping grooves for clamping the side arms are formed in the slide block, and limiting columns are arranged on the two groups of side arms;

the lug bosses are symmetrically provided with a plurality of groups of limiting holes at two sides of the strip-shaped groove and used for clamping limiting columns on the side arms; and a pull rod is fixedly arranged on the connecting disc.

Furthermore, a second guide groove is formed in the circumferential outer wall of the sleeve, a spherical sliding block is arranged on the second half shell corresponding to the second guide groove, and the spherical sliding block is slidably mounted inside the strip-shaped groove.

Compared with the prior art, the invention has the beneficial effects that: in the electricity generation impeller course of operation, when the wind speed is less than a definite value, first blade and the coincidence of second blade, the windward stress area of electricity generation impeller this moment is minimum, when the wind speed changes, under wind induction system's effect, make transmission drive adjusting device work, thereby make half shell of second rotate along the sleeve axis, thereby make first blade and second blade take place the dislocation, through the aforesaid setting, the windward stress area that makes the wind power generation impeller can be along with wind power automatically regulated, promote aerogenerator's generating efficiency.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is an axial schematic view of the present invention;

FIG. 3 is a cross-sectional view of the structure of the shaft tube and sleeve;

FIG. 4 is an exploded view of the first housing half and sleeve configuration;

FIG. 5 is a schematic view of the connection between the support rod and the push ring;

FIG. 6 is a schematic view of the connection between the carrier rod and the supporting plate;

FIG. 7 is an enlarged schematic view of section A of FIG. 2;

FIG. 8 is an enlarged view of the positioning device;

in the drawings, the reference numbers: 1. an axle tube; 2. a sleeve; 3. a first half shell; 4. a first blade; 5. a second half shell; 6. a second blade; 7. a universal joint; 8. a connecting rod; 9. a first spring; 10. a connecting lantern ring; 11. a support bar; 12. a push ring; 13. mounting grooves; 14. a wire guide wheel; 15. connecting ropes; 16. a connecting rod; 17. a top rod; 18. a support plate; 19. a second spring; 20. a stress plate; 21. an amplifying tube; 22. a positioning device; 23. a first guide groove; 24. a protrusion; 25. a boss; 26. a strip-shaped groove; 27. a slider; 28. mounting holes; 29. a third spring; 30. a connecting disc; 31. a side arm; 32. a card slot; 33. a limiting column; 34. a limiting hole; 35. a pull rod; 36. a second guide groove.

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.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like are based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, or may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. This embodiment is written in a progressive manner.

As shown in fig. 1 to 2, a wind power generation impeller capable of automatically adjusting a windward force-bearing surface according to the present invention includes:

the wind power generation device comprises a shaft tube 1, wherein a wind power induction device is arranged in the shaft tube 1, and a transmission device is arranged on the outer wall of the shaft tube 1;

the device comprises a sleeve 2, wherein the sleeve 2 is coaxially and rotatably arranged on a shaft tube 1, a first half shell 3 is fixedly arranged on the circumferential outer wall of the sleeve 2, a second half shell 5 is arranged on the circumferential outer wall of the sleeve 2, a first blade 4 is fixedly arranged on the first half shell 3, a second blade 6 is fixedly arranged on the second half shell 5, and an adjusting device is arranged between the first half shell 3 and the second half shell 5 and is used for enabling the first blade 4 and the second blade 6 to coincide under the action of no external force;

the wind power induction device is used for driving the adjusting device through the transmission device according to the wind power so as to enable the first blade 4 and the second blade 6 to be staggered;

in this embodiment, in the working process of the power generation impeller, when the wind speed is less than a certain value, the first blade 4 and the second blade 6 are overlapped, the windward stress area of the power generation impeller is the minimum at the moment, when the wind speed changes, under the action of the wind sensing device, the transmission device drives the adjusting device to work, so that the second half shell 5 rotates along the axis of the sleeve 2, the first blade 4 and the second blade 6 are staggered, through the arrangement, the windward stress area of the wind power generation impeller can be automatically adjusted along with the wind power, and the power generation efficiency of the wind power generator is improved.

Preferably, as shown in fig. 4, the adjusting device includes a plurality of groups of connecting rods 8 and first springs 9, universal joints 7 are respectively disposed at two ends of each connecting rod 8, the connecting rods 8 are obliquely mounted between the inner end of the first half-shell 3 and the inner end of the second half-shell 5 through the universal joints 7, and the plurality of groups of connecting rods 8 are circumferentially arrayed with the axis of the sleeve 2 as an axis;

the first spring 9 is sleeved outside the sleeve 2, the first spring 9 is always in non-contact with the plurality of groups of connecting rods 8, and two ends of the first spring 9 are respectively in rotating connection with the inner end of the first half shell 3 and the inner end of the second half shell 5;

in this embodiment, through setting up connecting rod 8, when making second half shell 5 keep away from first half shell 3 under the spring action of first spring 9, can rotate along sleeve pipe 2 axis, thereby make second blade 6 and first blade 4 take place to overlap, and under the transmission effect promotes, make second half shell 5 when being close to first half shell 3, make second half shell 5 rotate along sleeve pipe 2 axis, thereby make second blade 6 and first blade 4 take place to misplace, be convenient for adjust windward force area.

As shown in fig. 3 to 6, the transmission device preferably includes a connecting sleeve ring 10 slidably mounted on the shaft tube 1 and a push ring 12 slidably mounted on the shaft tube 1, a plurality of sets of support rods 11 are fixedly disposed between the connecting sleeve ring 10 and the push ring 12, the push ring 12 is used for pushing the second half shell 5 to approach the first half shell 3 against the elastic force of the first spring 9, and the connecting sleeve ring 10 is used for linking with the wind sensing device.

As shown in fig. 3 to 6, the wind sensing device preferably includes two sets of wire guiding wheels 14, two sets of connecting ropes 15, a top rod 17 and a stressed plate 20, two sets of mounting grooves 13 are symmetrically arranged on the outer wall of the shaft tube 1 in a penetrating manner, the two sets of wire guiding wheels 14 are respectively rotatably mounted inside the two sets of mounting grooves 13, the axes of the two sets of wire guiding wheels 14 are perpendicular to the axis of the shaft tube 1, and the two sets of connecting ropes 15 are respectively wound around the two sets of wire guiding wheels 14;

a supporting plate 18 is fixedly arranged inside the shaft tube 1, a top rod 17 movably penetrates through the supporting plate 18, the axis of the top rod 17 is parallel to the axis of the shaft tube 1, a connecting rod 16 is fixedly arranged at one end of the top rod 17 close to the connecting lantern ring 10, one ends of the two groups of connecting ropes 15, which are positioned outside the shaft tube 1, are fixedly connected with the connecting lantern ring 10, and one ends of the two groups of connecting ropes 15, which are positioned inside the shaft tube 1, are fixedly connected with two ends of the connecting rod 16 respectively;

the other end of the ejector rod 17 is coaxially and fixedly provided with a stress plate 20, a second spring 19 is sleeved on the ejector rod 17, and the second spring 19 is positioned between the stress plate 20 and the supporting plate 18;

in the present embodiment, by means of the above arrangement, it is facilitated to convert the thrust of the wind into a power driving the movement of the second half-shell 5.

As a preference of the above technical solution, as shown in fig. 3 to 6, an amplifying tube 21 is coaxially arranged at one end of the shaft tube 1 away from the connection collar 10, the force-bearing plate 20 is positioned inside the amplifying tube 21, the diameter of the amplifying tube 21 is larger than that of the shaft tube 1, and the diameter of the amplifying tube 21 is smaller than that of the first half-shell 3;

the outer wall of the stress plate 20 is provided with a positioning device 22 for manually adjusting the windward stress area of the impeller;

in the present embodiment, the above arrangement is beneficial to make the wind force push the force bearing plate 20.

As a preferred embodiment of the above technical solution, as shown in fig. 5 to 6, a plurality of groups of first guide grooves 23 are formed on the outer wall of the shaft tube 1, a plurality of groups of protrusions 24 are formed on the inner wall of the connection sleeve ring 10 corresponding to the plurality of groups of first guide grooves 23, and the plurality of groups of first guide grooves 23 are respectively slidably installed inside the plurality of groups of protrusions 24;

in this embodiment, guiding the movement of the connection collar 10 is facilitated by the above arrangement.

As shown in fig. 7 to 8, the positioning device 22 preferably comprises a boss 25 and a slider 27 fixedly mounted on the amplifying tube 21, wherein the boss 25 is provided with a strip-shaped groove 26 penetrating through the amplifying tube 21, and the extension line of the strip-shaped groove 26 is parallel to the axis of the amplifying tube 21;

the slide block 27 is slidably mounted in the strip-shaped groove 26, one end of the slide block 27, which is located inside the amplifying tube 21, is fixedly connected with the side wall of the stress plate 20, the other end of the slide block 27 is provided with a mounting hole 28, a third spring 29 is mounted inside the mounting hole 28, one end, which is far away from the stress plate 20, of the third spring 29 is rotatably mounted with a connecting disc 30, two groups of side arms 31 are symmetrically and fixedly arranged on the side wall of the connecting disc 30, two groups of clamping grooves 32 for the side arms 31 to be clamped are formed in the slide block 27, and limiting columns 33 are respectively arranged on the two groups of side arms 31;

the boss 25 is symmetrically provided with a plurality of groups of limiting holes 34 at two sides of the strip-shaped groove 26, and the limiting holes are used for clamping limiting columns 33 on the side arms 31; a pull rod 35 is fixedly arranged on the connecting disc 30;

in this embodiment, through the above arrangement, when the side arm 31 is clamped into the clamping groove 32, the windward stressed area of the impeller can be automatically adjusted, the connection pad 30 is rotated and pulled outwards to enable the limiting post 33 to be inserted into the limiting hole 34, the windward stressed area of the impeller is fixed, and the windward stressed area of the impeller can be manually adjusted by arranging the plurality of groups of limiting holes 34.

As a preferred mode of the above technical solution, as shown in fig. 4, a second guide groove 36 is provided on the circumferential outer wall of the sleeve 2, a spherical slider is provided on the second half-shell 5 corresponding to the second guide groove 36, and the spherical slider is slidably mounted inside the strip-shaped groove 26;

in the present embodiment, the guiding of the movement of the second half-shell 5 is facilitated by the above arrangement.

The wind power generation impeller capable of automatically adjusting the windward force bearing surface is mounted, connected or arranged in a common mechanical mode, and can be implemented as long as the beneficial effects of the wind power generation impeller can be achieved.

The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.