阅读说明：本技术 阀球结构及其球阀开关 (Valve ball structure and ball valve switch thereof ) 是由 郑如松 于 2019-02-27 设计创作，主要内容包括：本发明提供一种阀球结构,其包括阀球本体,其外观大致呈球状且一体制成,阀球本体穿设有第一开口及第二开口,阀球本体设有用以连通第一开口及该第二开口的通道,所述通道由第一开口往第二开口渐缩延伸,阀球本体的各个轴线当中,阀球本体的两侧垂直于第一开口的轴线与第二开口的轴线分别穿设有一卡掣孔,使阀球本体以各卡掣孔为中心转动；本发明阀球结构的通道呈渐缩设计,能有效干扰及破坏液态介质中的颗粒流动,因而达到降低通道残留颗粒的功效,以提升液态介质的流通效率。(The invention provides a valve ball structure, which comprises a valve ball body, wherein the appearance of the valve ball body is approximately spherical and is integrally manufactured, a first opening and a second opening are arranged in the valve ball body in a penetrating way, a channel for communicating the first opening with the second opening is arranged on the valve ball body, the channel gradually shrinks and extends from the first opening to the second opening, and in each axis of the valve ball body, a clamping hole is respectively arranged on two sides of the valve ball body, which are vertical to the axis of the first opening and the axis of the second opening in a penetrating way, so that the valve ball body rotates by taking each clamping hole as a center; the passage of the valve ball structure is designed in a gradually reducing mode, and can effectively interfere and destroy the flow of particles in the liquid medium, so that the effect of reducing the residual particles in the passage is achieved, and the circulation efficiency of the liquid medium is improved.)

1. A valve ball structure, comprising:

the valve ball body is roughly spherical in appearance and integrally manufactured, a first opening and a second opening are formed in the valve ball body in a penetrating mode, a channel used for communicating the first opening with the second opening is formed in the valve ball body, the channel gradually shrinks and extends from the first opening to the second opening, and clamping holes are formed in two sides of the valve ball body in a penetrating mode along the axial direction perpendicular to the first opening and the axial direction perpendicular to the second opening.

2. The valve ball structure of claim 1, wherein the second opening is defined by two beveled edges and an arcuate edge, one end of the beveled edges being connected to each other and the beveled edges being disposed at an acute angle, the arcuate edge being connected to the other end of the beveled edges, the linear distance between the middle point of the arcuate edge and the point of connection of the beveled edges being equal to the diameter of the first opening.

3. The valve ball structure of claim 2, wherein the valve ball body has a flat surface on each of two sides thereof, the two flat surfaces being parallel to each other, a spherical surface being disposed between the two flat surfaces, each of the detent holes passing through each of the flat surfaces and communicating with the passage, the first and second ports passing through the spherical center of the valve ball body and being parallel to the two flat surfaces, the second port having a second imaginary surface obtained by translating a straight line from the middle point of the arc-shaped edge to the connecting point of the two oblique edges, and the second imaginary surface being coincident with the first imaginary surface.

4. The valve ball structure of claim 1 wherein said valve ball body has a first axis that passes through and is collinear with the centerline of both said detent holes, and a second axis that is collinear with the centerline of said valve ball body, said two detent holes passing through respective ends of said second axis, said first axis and said second axis being non-collinear.

5. The valve ball structure of claim 1 wherein the channel inner wall has a flat section and a sloped section, the flat section is connected to the first opening, the sloped section is connected to the second opening, and each detent hole penetrates at an intersection of the sloped section and the flat section.

6. The valve ball structure of claim 1 wherein each detent hole is generally regular hexagonal and the valve ball body is made of duplex stainless steel.

7. The valve ball structure of claim 1 wherein the first opening is generally circular for input of media and the second opening is generally fan shaped for output of media.

8. A ball valve switch including a valve ball structure according to any one of claims 1 to 7, comprising:

the valve body is internally provided with a containing chamber, an axial flow passage, a radial through hole and a trepanning, the containing chamber is communicated with the axial flow passage, the radial through hole and the trepanning, the trepanning is aligned to the radial through hole, the containing chamber is internally provided with the valve ball body, two clamping holes of the valve ball body respectively correspond to the radial through hole and the trepanning, and a channel of the valve ball body can be selectively communicated with the axial flow passage by pivoting along with the valve ball body;

the positioning rod is sleeved in the sleeve hole of the valve body, and one end of the positioning rod protrudes out of the axial flow channel and is embedded in one clamping hole of the valve ball body; and

the shaft rod penetrates through the radial through hole of the valve body, one end of the shaft rod is embedded in the other clamping hole of the valve ball body, the shaft rod can rotate 90 degrees in the forward and reverse directions, the positioning rod can be synchronously driven to rotate, and the valve ball body is closed or the axial flow channel is opened.

9. The ball valve switch according to claim 8, further comprising a leakage preventing member disposed in an axial flow passage of the valve body, wherein the valve body has an input end and an output end, the axial flow passage penetrates the input end and the output end, the output end of the valve body is provided with an inner tube connected to the axial flow passage through a screw, the leakage preventing member is disposed around an aperture of the inner tube, the valve ball body abuts against the leakage preventing member, so that the leakage preventing member elastically abuts between the valve ball body and the inner tube, and a second opening of the valve ball body faces the inner tube, so that the axial flow passage communicates with the inner tube through a passage of the valve ball body.

10. The ball valve switch according to claim 9, wherein the anti-leaking member comprises an elastic body, an O-ring and an abutting ring, the elastic body abuts against the inner tube, the O-ring is tightly fitted around the elastic body, one side of the abutting ring abuts against the O-ring and the elastic body, so that the O-ring is embedded between the elastic body and the abutting ring, the other side of the abutting ring is arcuately recessed with a sealing groove, and the valve ball body is tightly embedded in the sealing groove; the elastic body can be a spring or a shrapnel, and the O-shaped ring is made of elastic materials with a net-shaped structure.

Technical Field

The invention relates to the field of fluid switches, in particular to a valve ball structure and a ball valve switch thereof.

Background

Ball valve devices are widely used in fluid delivery pipelines for opening, closing or regulating flow, and are commonly used in industrial, petrochemical, medical and other fields besides household pipelines in the construction industry.

Generally, a ball valve device in the prior art mainly includes a valve body, a valve ball and a valve rod, wherein a chamber is disposed inside the valve body, the valve ball is mounted inside the valve body and accommodated in the chamber, and the valve rod is used to drive and control the rotation of the valve ball, so that the ball valve device achieves the purpose of opening and closing the flow rate.

However, the conventional valve ball has some disadvantages, for example, most of the through holes of the conventional valve ball are circular openings, and when suspended matter or granular media in fluid flows through the through holes of the valve ball, the suspended matter or granular media are easily remained due to the uniform flow rate of the through holes, and the through holes of the valve ball are blocked or the flow port is shrunk after long-term use, so that the valve ball cannot regulate the flow.

Furthermore, the existing valve ball is usually made of stainless steel 304, and due to the material factor of the valve ball, spray welding hardening, processing and grinding are required after forming to complete the final product, but the whole manufacturing process is complicated, the production flow is long, and further the production cost is increased; moreover, when the valve ball and the water stop ring rub for a long time, the friction loss phenomenon of the valve ball or the water stop ring is easily caused, so that the service life of the ball valve device is further influenced, and meanwhile, the potential safety hazard is also accompanied.

In addition, the existing ball valve is fixed by a pneumatic or electric actuator in a single side and serves as a driving force for rotation, but during the operation of the ball valve, the ball valve is continuously shaken, deviated and rubbed due to fluid impact, so that the ball valve generates a gap due to abrasion, and further cannot be accurately positioned at the center of the valve body, thereby causing the fluid outflow condition, and even causing the problem of reduction of the control accuracy of the ball valve device.

Disclosure of Invention

In view of the above, it is necessary to provide a ball structure and a ball valve switch thereof, aiming at the problem that the existing ball valve is easy to block and leak.

The above purpose is realized by the following technical scheme:

a valve ball structure comprising: the valve ball body is roughly spherical in appearance and integrally manufactured, a first opening and a second opening are formed in the valve ball body in a penetrating mode, a channel used for communicating the first opening with the second opening is formed in the valve ball body, the channel gradually shrinks and extends from the first opening to the second opening, and clamping holes are formed in two sides of the valve ball body in a penetrating mode along the axial direction perpendicular to the first opening and the axial direction perpendicular to the second opening.

In one embodiment, the second opening is defined by two oblique edges and an arc edge, one ends of the two oblique edges are connected with each other, an acute angle is formed between the two oblique edges, the arc edge is connected to the other ends of the two oblique edges, and the linear distance between the middle point of the arc edge and the connection point of the two oblique edges is equal to the diameter of the first opening.

In one embodiment, the valve ball body has a flat surface on each of two sides thereof, the two flat surfaces are parallel to each other, a spherical surface is disposed between the two flat surfaces, each of the locking holes is formed through each of the flat surfaces and communicates with the channel, the first open/close ports and the second open/close ports are formed through the spherical surface, the valve ball body has a first imaginary surface, the first imaginary surface passes through the spherical center of the valve ball body and is parallel to the two flat surfaces, the second opening has a second imaginary surface, the second imaginary surface is obtained by translating a straight line from the middle point of the arc edge to the connection point of the two oblique edges, and the second imaginary surface is overlapped with the first imaginary surface.

In one embodiment, the valve ball body has a first axis, the first axis penetrates through the two detent holes and is collinear with the center lines of the two detent holes, the valve ball body has a second axis, the second axis is collinear with the center line of the valve ball body, the two detent holes are respectively arranged at two ends of the second axis, and the first axis and the second axis are not collinear.

In one embodiment, the inner wall of the channel has a plane section and an inclined section, the plane section is connected to the first opening, the inclined section is connected to the second opening, and each of the locking holes penetrates through an intersection of the inclined section and the plane section.

In one embodiment, each of the detent holes is generally in the shape of a regular hexagon, and the valve ball body is made of duplex stainless steel.

In one embodiment, the first opening is substantially circular for inputting media, and the second opening is substantially fan-shaped for outputting media.

The present invention also provides a ball valve switch including the ball structure of any one of the above embodiments, comprising:

the valve body is internally provided with a containing chamber, an axial flow passage, a radial through hole and a trepanning, the containing chamber is communicated with the axial flow passage, the radial through hole and the trepanning, the trepanning is aligned to the radial through hole, the containing chamber is internally provided with the valve ball body, two clamping holes of the valve ball body respectively correspond to the radial through hole and the trepanning, and a channel of the valve ball body can be selectively communicated with the axial flow passage by pivoting along with the valve ball body;

the positioning rod is sleeved in the sleeve hole of the valve body, and one end of the positioning rod protrudes out of the axial flow channel and is embedded in one clamping hole of the valve ball body; and

the shaft rod penetrates through the radial through hole of the valve body, one end of the shaft rod is embedded in the other clamping hole of the valve ball body, the shaft rod can rotate 90 degrees in the forward and reverse directions, the positioning rod can be synchronously driven to rotate, and the valve ball body is closed or the axial flow channel is opened.

In one embodiment, the ball valve switch further includes a leakage-proof member, which is sleeved in an axial flow passage of the valve body, the valve body has an input end and an output end, the axial flow passage penetrates through the input end and the output end, the output end of the valve body is provided with an inner tube connected and communicated with the axial flow passage through a thread, the leakage-proof member is disposed around the caliber of the inner tube, the valve ball body abuts against the leakage-proof member, so that the leakage-proof member elastically abuts against between the valve ball body and the inner tube, and a second opening of the valve ball body faces the inner tube, so that the axial flow passage is communicated with the inner tube through a passage of the valve ball body.

In one embodiment, the anti-leakage member includes an elastic body, an O-ring and a butting ring, the elastic body is butted against the inner tube, the O-ring is tightly sealed around the elastic body, one side of the butting ring is butted against the O-ring and the elastic body, so that the O-ring is embedded between the elastic body and the butting ring, the other side of the butting ring is arc-shaped and concave with a sealing groove, and the valve ball body is tightly embedded in the sealing groove; the elastic body can be a spring or a shrapnel, and the O-shaped ring is made of elastic materials with a net-shaped structure.

The invention has the beneficial effects that:

the passage of the valve ball structure of the invention is designed in a gradually reducing way, which can effectively interfere and destroy the flow of particles in the liquid medium, thereby achieving the effect of reducing the particles remained in the passage, improving the circulation efficiency of the liquid medium, and leading the valve ball body and the ball valve switch of the invention to be widely applied to various industries.

Moreover, two clamping holes of the valve ball body can be assembled on the fixing effect of the ball valve switch in a lifting mode, and the axis of each clamping hole and the sphere center of the valve ball body are arranged in a double-eccentric mode.

Drawings

FIG. 1 is a perspective view of the valve ball structure of the present invention;

FIG. 2 is a perspective view of another aspect of the valve ball structure of the present invention;

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a front view of FIG. 2;

FIG. 5 is a cross-sectional view of the valve ball structure of the present invention taken along section line A-A of FIG. 3;

FIG. 6 is a cross-sectional view of the valve ball structure of the present invention taken along section line B-B of FIG. 3;

FIG. 7 is a schematic longitudinal cross-sectional view of the ball valve switch of the present invention;

FIG. 8 is a schematic cross-sectional view of the ball valve switch of the present invention showing the axial flow passage of the valve body in a fully open position;

FIG. 9 is a schematic view (I) of the operation of the ball valve switch of the present invention, showing the axial flow path of the valve body in a half-open state;

fig. 10 is a schematic diagram (ii) showing the operation of the ball valve switch of the present invention, showing the axial flow passage of the valve body in a closed state.

Wherein:

ball valve switch 100 trepan 24

Input end 25 of valve ball body 10

Planar 11 output 26

Spherical 12 positioning rod 30

First opening 13 shaft 40

Second opening 14 leak preventer 50

Beveled 141 elastomer 51

O-ring 52 with curved edge 142

Channel 15 abuts ring 53

Planar segment 151 mating groove 531

Inner tube 60 of ramp section 152

The first imaginary plane D1 of the locking hole 16

Second imaginary plane D2 of valve body 20

First axis L1 of chamber 21

Axial flow passage 22 second axis L2

A radial through hole 23.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below by way of embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The numbering of the components themselves, such as "first", "second", etc., is used herein only to distinguish between the objects depicted and not to have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or components must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1 to 6, the present invention provides a valve ball structure, which includes:

the valve ball body 10 is made of a two-phase stainless steel material, so as to improve the casting efficiency and yield, the upper and lower sides of the valve ball body 10 are respectively provided with a plane 11, the two planes 11 are parallel to each other, and a spherical surface 12 located between the two planes 11, a first opening 13 and a second opening 14 are arranged on the spherical surface 12 of the valve ball body 10, as shown in fig. 3 and 4, the first opening 13 is substantially circular for feeding the liquid medium, the second opening 14 is substantially fan-shaped for feeding the liquid medium, the valve ball body 10 is provided with a passage 15 inside to communicate the first opening 13 and the second opening 14, the passage 15 extends from the first opening 13 to the second opening 14 in a tapering manner, the inner wall of the channel 15 has a plane section 151 and a slope section 152, the plane section 151 is connected to the first opening 13, and the slope section 152 is connected to the second opening 14 by the plane section 151 in a tapered manner.

The present invention further describes the manner and the opening direction of the second opening 14, as shown in fig. 3, the second opening 14 is surrounded by two inclined sides 141 and an arc side 142, one ends of the two inclined sides 141 are connected to each other so that an acute angle is formed between the two inclined sides 141, the arc side 142 is connected to the other ends of the two inclined sides 141, and the linear distance between the middle point of the arc side 142 and the connection point of the two inclined sides 141 is equal to the diameter of the first opening 13.

It should be noted that the valve ball body 10 is provided with a first imaginary plane D1, the first imaginary plane D1 passes through the center of the valve ball body 10 and is parallel to the two planes 11, the second opening 14 is provided with a second imaginary plane D2, the second imaginary plane D2 is obtained by translating a straight line from the middle point of the arc edge 142 to the connecting point of the two inclined edges 141, and the second imaginary plane D2 is overlapped with the first imaginary plane D1; that is, the second opening 14 opens transversely on the spherical surface 12 of the valve ball body 10; when the liquid medium is output from the fan-shaped second opening 14, the inclined surface section 152 in the channel 15 can increase the output flow rate of the liquid medium, so that the particles mixed in the liquid medium are extruded to rub the inclined surface section 152 of the channel 15, and further the particle structure in the liquid medium can be disturbed and destroyed, thereby achieving the effect of reducing the residual particles in the channel 15, improving the circulation efficiency of the liquid medium, and enabling the valve ball body 10 of the present invention to be widely applied to various industries.

In addition, among the axes of the ball body 10, the axis of the ball body 10 perpendicular to the first opening 13 and the axis of the second opening 14 are respectively provided with a detent hole 16, each detent hole 16 is generally in the shape of a regular hexagon, which can improve the limiting effect of each detent hole 16, so that the ball body 10 rotates around each detent hole 16. Specifically, each locking hole 16 is respectively disposed through the two planes 11 of the ball body 10 and communicated to the channel 15, wherein each locking hole 16 penetrates between the plane section 151 and the inclined section 152, as shown in fig. 5.

It should be noted that each detent hole 16 is eccentrically disposed on the valve ball body 10, specifically, the valve ball body 10 has a first axis L1, the first axis L1 penetrates through the two detent holes 16, and the first axis L1 and the center lines of the two detent holes 16 are arranged in a collinear manner, so that the valve ball body 10 rotates around the first axis L1, the valve ball body 10 has a second axis L2, the two detent holes 16 are respectively arranged at two ends of the second axis L2, the first axis L1 and the second axis L2 are not collinear, and the detent holes 16 are doubly eccentrically disposed on the valve ball body 10, so that the valve ball body 10 can achieve the labor saving operation effect during rotation.

Referring to fig. 7 to 10, another embodiment of the present invention provides a ball valve switch 100 including the above-mentioned ball structure, which includes the above-mentioned ball body 10, a valve body 20, a positioning rod 30, a shaft 40 and a leakage-proof member 50.

In this embodiment, the valve body 20 is assembled with the valve ball body 10 in the accommodating chamber 21, the two latching holes 16 of the valve ball body 10 respectively face the radial through hole 23 and the trepan 24, the first opening 13 and the second opening 14 respectively face the axial through hole 22 and the inner tube 60, and the passage 15 of the valve ball body 10 can rotate along with the rotation of the valve ball body 10, and further selectively communicate with the axial through hole 22.

The positioning rod 30 is sleeved in the sleeve hole 24 of the valve body 20, and one end of the positioning rod 30 protrudes out of the axial flow passage 22 and is embedded in one of the locking holes 16 of the valve ball body 10.

The shaft lever 40 penetrates through the radial through hole 23 of the valve body 20, one end of the shaft lever 40 is embedded in the other clamping hole 16 of the valve ball body 10, and at the moment, the valve ball body 10 is respectively fixed by the positioning rod 30 and the two sides of the shaft lever 40, so that the fixing effect of the valve ball body 10 can be improved, and the stability of the valve ball body 10 assembled on the valve body 20 is further stabilized; the ball valve switch 100 of the invention can synchronously drive the positioning rod 30 to rotate by rotating the shaft rod 40 in the forward and reverse directions by 90 degrees, so that the valve ball body 10 achieves the purpose of closing or opening the axial flow passage 22; when the valve ball body 10 rotates to make the second opening 14 face the inner tube 60, the axial flow passage 22 is communicated with the inner tube 60 through the passage 15 of the valve ball body 10 to be in an open state; when the valve ball body 10 rotates to make the spherical surface 12 cover the opening of the inner tube 60, the axial flow passage 22 is closed.

The anti-leakage element 50 is sleeved in the axial flow passage 22 of the valve body 20, the anti-leakage element 50 is arranged around the caliber of the inner pipe 60, the valve ball body 10 abuts against the anti-leakage element 50, so that the anti-leakage element 50 elastically abuts against between the valve ball body 10 and the inner pipe 60 to absorb the vibration and pressure of the valve ball body 10, so as to improve the stability of the valve ball body 10 in operation and further achieve the buffering effect; further, the anti-leaking member 50 includes an elastic body 51, an O-ring 52 and an abutting ring 53, wherein the elastic body 51 can be a spring or a leaf spring abutting against the aperture of the inner tube 60 for elastic compensation; the O-ring 52 is an elastic material with a net structure, and is tightly sealed around the elastic body 51, in the embodiment, the O-ring 52 is used for absorbing the pressure generated by the valve ball body 10 to achieve the buffering effect; one side of the abutting ring 53 abuts against the O-ring 52 and the elastic body 51, so that the O-ring 52 is fitted between the elastic body 51 and the abutting ring 53, the other side of the abutting ring 53 is arcuately recessed with a sealing groove 531, and the spherical surface 12 of the valve ball body 10 is tightly fitted in the sealing groove 531.

Referring to fig. 7 to 10, in an actual operation of the ball valve switch 100 of the present invention, the ball valve body 10 is pivoted to connect the channel 15 and the axial flow channel 22, and the first opening 13 and the second opening 14 respectively face the axial flow channel 22 and the inner tube 60, so that the ball valve switch 100 is in a fully open state, wherein the inclined surface section 152 in the channel 15 can increase an output flow rate of the liquid medium, so that particles mixed in the liquid medium are squeezed to rub against the inclined surface section 152 of the channel 15, thereby interfering and destroying a particle structure in the liquid medium, achieving an effect of reducing particles remaining in the channel 15, and increasing a flow efficiency of the liquid medium, as shown in fig. 8.

When the ball valve body 10 rotates clockwise, the spherical surface 12 of the ball valve body 10 is rotated to partially shield the gap between the axial flow passage 22 and the chamber 21, so that the ball valve switch 100 is in a half-open state, as shown in fig. 9. Then, when the valve ball body 10 continues to rotate and the spherical surface 12 completely covers the abutting ring 53, since the axes of the locking holes 16 and the spherical center of the valve ball body 10 are arranged in a double eccentric manner, the valve ball body 10 can achieve the effect of labor-saving operation when rotating, and when the ball valve switch 100 closes the axial flow passage 22, the spherical surface 12 of the valve ball body 10 can be further completely embedded in the sealing groove 531 of the abutting ring 53 in a sealing manner, so that the ball valve switch 100 is in an open state, and the effect of preventing the ball valve switch 100 from leaking is achieved, as shown in fig. 10; the anti-leaking member 50 elastically abuts between the valve ball body 10 and the inner tube 60 to absorb the shock and pressure of the valve ball body 10, so as to improve the stability of the valve ball body 10, thereby achieving the buffering effect.

The passage 15 of the ball structure of the present invention is designed to be tapered, which can effectively interfere and destroy the flow of particles in the liquid medium, thereby reducing the effect of particles remaining in the passage 15, and increasing the circulation efficiency of the liquid medium, so that the ball body 10 and the ball switch 100 of the present invention can be widely applied to various industries.

Moreover, the two latching holes 16 of the ball body 10 can lift and assemble the fixing function of the ball switch 100, and the axis of each latching hole 16 and the center of the ball body 10 are arranged in a double eccentric manner, so that the ball body 10 can achieve the effect of labor-saving operation when rotating, and when the axial flow passage 22 of the ball switch 100 is closed, the ball body 10 can be further tightly embedded into the anti-leakage element 50 of the ball switch 100, thereby achieving the effect of preventing the ball switch 100 from leaking.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.