1. A helical drill assembly, comprising:

the first drill rod comprises a first core rod and a first spiral blade, the first spiral blade is fixedly connected with the outer peripheral surface of the first core rod, a first water flow channel extending along the extending direction of the first core rod is arranged on the first core rod, the first core rod is provided with a first end and a second end opposite to the extending direction of the first core rod, a first joint is arranged at the first end of the first core rod, and the first joint can be matched with a drill rod joint on a driving shaft of the spiral drilling machine; and

the second drill rod comprises a second core rod and a second spiral blade, the maximum outer diameter of the second spiral blade is larger than that of the first spiral blade, the second spiral blade is fixedly connected with the outer peripheral surface of the second core rod, a second water flow channel extending along the extending direction of the second core rod is arranged on the second core rod, the second core rod is provided with a first end and a second end opposite to each other in the extending direction of the second core rod, the first end of the second core rod is provided with a second joint, and the second joint can be matched with the drill rod joint.

2. The spiral drill assembly of claim 1, wherein the first sub is in a plug-in engagement with the drill pipe joint and the second sub is in a plug-in engagement with the drill pipe joint.

3. The spiral drill assembly of claim 2, wherein each of the first and second joints is an inner octagon joint.

4. The auger assembly according to any one of claims 1-3 further comprising a small diameter drill bit having a bit sub disposed thereon, the second end of the first core rod having a third sub disposed thereon, the third sub being engageable with the bit sub.

5. Spiral drill assembly according to claim 4, wherein the first drill rod is provided in plurality, and the third joint is engageable with the first joint.

6. The auger assembly according to any one of claims 1-3, further comprising a large diameter drill bit having a counterbore joint thereon, the second end of the second core rod having a fourth joint thereon, the fourth joint being engageable with the counterbore joint.

7. Spiral drill assembly according to claim 6, wherein the second drill rod is provided in plurality, and the fourth joint is engageable with the second joint.

8. The auger assembly according to claim 6, further comprising a guide rod connected to the second end of the large diameter drill bit.

9. The spiral drill assembly of any one of claims 1-3, wherein the diameter of the first core and the diameter of the second core are equal, and the bore diameters of the first water flow passage and the second water flow passage are equal.

10. An auger drill, comprising:

the driving shaft is provided with a first end and a second end which are opposite in the extending direction of the driving shaft, and the second end of the driving shaft is provided with a drill rod joint; and

a helical drill assembly according to any one of claims 1 to 9, the first and second subs being interchangeably engageable and connectable with the drill pipe joints.

Background

Coal mining technology is increasing day by day, and the advancing speed of working face is faster and faster, and gas mining in high gas mine faces higher and higher requirement. The technology of drilling a hole with an ultra-large diameter by using a tunnel drilling machine and inserting a large-diameter extraction pipeline into the hole instead of a tunnel gradually obtains more and more people's approval, and the technology of drilling the hole with the large diameter instead of the tunnel not only greatly reduces investment and is easy for later management, but also can obviously improve the gas extraction effect of a coal face. However, in the large-diameter drilling construction, if a large-diameter drilling tool is used to form a hole at one time, the position of a final hole cannot be controlled in the construction process because of the heavy weight of a drill rod and a drill bit of the large-diameter drilling tool, so that the drilling is prone to deflection and the precision of the final hole is low. Meanwhile, the large-diameter drilling tool is easy to drill to the top plate and the bottom plate, so that drilling holes are scrapped, and the construction efficiency and the reliability of the spiral drilling machine are reduced. Because the final hole position of the small-diameter drilling hole is accurate, the method that the small-diameter drilling hole is firstly constructed by the small-diameter drilling tool and then the large-diameter drilling hole is reamed by the large-diameter drilling tool to form the large-diameter drilling hole is mostly adopted in the related technology, so that the precision of the final hole of the large-diameter drilling hole is improved.

In the related technology, the size difference between the core rod of the large-diameter drilling tool and the core rod of the small-diameter drilling tool is large, two spiral drilling machines are needed to be used for successively and respectively constructing the small-diameter drilling hole and the large-diameter drilling hole, and the problems of low construction efficiency, inaccurate drilling hole positioning after the spiral drilling machines are replaced and the like exist.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.

To this end, embodiments of the present invention provide a spiral drill assembly that is capable of constructing drill holes having different diameters.

The embodiment of the invention provides a spiral drilling machine, which can be used for replacing drill rods of different types on the same spiral drilling machine so as to construct drill holes of different diameters.

A helical drill assembly according to an embodiment of the present invention comprises:

the first drill rod comprises a first core rod and a first spiral blade, the first spiral blade is fixedly connected with the outer peripheral surface of the first core rod, a first water flow channel extending along the extending direction of the first core rod is arranged on the first core rod, the first core rod is provided with a first end and a second end opposite to the extending direction of the first core rod, a first joint is arranged at the first end of the first core rod, and the first joint can be matched with a drill rod joint on a driving shaft of the spiral drilling machine; and

the second drill rod comprises a second core rod and a second spiral blade, the maximum outer diameter of the second spiral blade is larger than that of the first spiral blade, the second spiral blade is fixedly connected with the outer peripheral surface of the second core rod, a second water flow channel extending along the extending direction of the second core rod is arranged on the second core rod, the second core rod is provided with a first end and a second end opposite to each other in the extending direction of the second core rod, the first end of the second core rod is provided with a second joint, and the second joint can be matched with the drill rod joint.

The spiral drilling tool assembly provided by the embodiment of the invention has the advantages of high drilling efficiency, good final hole precision and the like.

In some embodiments, the first sub is in a plug-in fit with the drill pipe sub and the second sub is in a plug-in fit with the drill pipe sub.

In some embodiments, each of the first and second joints is an inner eight-way joint.

In some embodiments, the auger assembly further comprises a small diameter drill bit having a bit sub disposed thereon, the second end of the first core rod having a third sub, the third sub being mateable with the bit sub.

In some embodiments, the first drill pipe is provided in plurality, and the third sub is capable of mating with the first sub.

In some embodiments, the auger assembly further comprises a large diameter drill bit having a counterbore joint thereon, the second end of the second core rod having a fourth joint thereon, the fourth joint being mateable with the counterbore joint.

In some embodiments, the second drill pipe is provided in plurality, and the fourth sub is capable of mating with the second sub.

In some embodiments, the auger assembly further comprises a guide rod connected to the second end of the large diameter drill bit.

In some embodiments, the diameter of the first core and the diameter of the second core are equal, and the diameter of the first water flow channel and the second water flow channel are equal.

An auger drill according to an embodiment of the present invention includes:

the driving shaft is provided with a first end and a second end which are opposite in the extending direction of the driving shaft, and the second end of the driving shaft is provided with a drill rod joint; and a helical drill assembly according to any one of the preceding embodiments, wherein the first and second subs are interchangeably engageable and connectable with the drill pipe joints.

According to the spiral drilling machine provided by the embodiment of the invention, drill rods with different models can be replaced on the same spiral drilling machine, and drill holes with different diameters are constructed, so that the problem that spiral drilling machines with different models are required for the construction of the original small-diameter drill hole and the large-diameter drill hole is solved, the construction efficiency of the large-diameter drill hole is improved, the double promotion of the hole forming rate and the construction efficiency of the large-diameter drill hole is realized, and the safe and efficient production of a mine is effectively ensured.

Drawings

FIG. 1 is a schematic view of a first drill of a helical drill assembly according to an embodiment of the present invention.

Fig. 2 is a schematic view of the first drill rod of fig. 1.

Fig. 3 is a schematic view of the small diameter drill bit of fig. 1.

Fig. 4 is a schematic view of fig. 2 at a first joint.

Fig. 5 is a schematic view of fig. 2 at a third joint.

Fig. 6 is a schematic view of a drive shaft of a screw drill according to an embodiment of the present invention.

FIG. 7 is a schematic view of a second drill of the helical drill assembly according to an embodiment of the present invention.

Fig. 8 is a schematic view of the second drill rod of fig. 7.

Fig. 9 is a schematic view of the large diameter drill bit of fig. 7.

Reference numerals:

a first drill rod 1; a first core rod 11; a first helical blade 12; a first water flow passage 13; a first joint 14; a third joint 15; a small diameter drill bit 16; a bit sub 161;

a second drill rod 2; a second core bar 21; the second helical blade 22; a second water flow passage 23; a second joint 24; a fourth joint 25; a large diameter drill bit 26; a counterbore joint 261; a threaded joint 262; a guide rod 27;

a driving shaft 3; a tool joint 31.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1 and 9, the auger drill according to the embodiment of the present invention includes a driving shaft 3 and an auger assembly. The drive shaft 3 has a first end and a second end opposite in its extending direction, and the second end of the drive shaft 3 is provided with a tool joint 31.

In order to make the technical solution of the present application easier to understand, the technical solution of the present application is further described below by taking as an example that the extending direction of the first core rod 11 coincides with the left-right direction, which is shown in fig. 1.

The right end of the driving shaft 3 is provided with a drill rod joint 31, and the left end of the driving shaft 3 is connected with a motor on the spiral drilling machine to provide power required by drilling.

A spiral drill assembly according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1 to 9, a spiral drill assembly according to an embodiment of the present invention includes a first drill rod 1 and a second drill rod 2.

The first drill rod 1 comprises a first core rod 11 and a first helical blade 12, wherein the first helical blade 12 is fixedly connected with the outer peripheral surface of the first core rod 11. The first core rod 11 is provided with a first water flow channel 13 extending along the extending direction of the first core rod, the first core rod 11 is provided with a first end and a second end opposite to the extending direction of the first core rod, the first end of the first core rod 11 is provided with a first joint 14, and the first joint 14 can be matched with a drill rod joint 31 on the driving shaft 3 of the spiral drilling machine.

The second drill rod 2 comprises a second core rod 21 and a second spiral blade 22, the maximum outer diameter of the second spiral blade 22 is larger than that of the first spiral blade 12, and the second spiral blade 22 is fixedly connected with the outer peripheral surface of the second core rod 21. The second core rod 21 is provided with a second water flow channel 23 extending along the extending direction of the second core rod 21, the second core rod 21 is provided with a first end and a second end opposite to each other in the extending direction of the second core rod, the first end of the second core rod 21 is provided with a second joint 24, and the second joint 24 can be matched with the drill rod joint 31.

The first drill rod 1 and the second drill rod 2 are replaceably engaged and connected to the drill rod coupling 31.

The first joint 14 is capable of cooperating with a tool joint 31 on the drive shaft 3 of the auger: when a drilling operation with the first drill rod 1 is required, the first joint 14 is matched with the drill rod joint 31 on the driving shaft 3; when the second drill rod 2 is required to be used for drilling, the first connector 14 is not matched with the drill rod connector 31 on the driving shaft 3, and the second connector 24 is matched with the drill rod connector 31 on the driving shaft 3; the first coupling 14 may or may not engage the tool coupling 31 on the drive shaft 3 when drilling operations are not required.

The second joint 24 is capable of cooperating with the tool joint 31 by: when the second drill rod 2 is required to be used for drilling, the second connector 24 is matched with the drill rod connector 31 on the driving shaft 3; when the first drill rod 1 is required to be used for drilling, the second joint 24 is not matched with the drill rod joint 31 on the driving shaft 3, and the first joint 14 is matched with the drill rod joint 31 on the driving shaft 3 of the spiral drilling machine; the second coupling 24 may or may not engage the tool coupling 31 on the drive shaft 3 when drilling operations are not required.

The first sub 14 and the second sub 24 are interchangeably mated with and connected to the tool joint 31 by: the first sub 14 engaged and connected to the tool joint 31 may be removed from the tool joint 31 and the second sub 24 engaged and connected to the tool joint 31; it is also possible to remove the second sub 24 engaged and connected to the tool joint 31 from the tool joint 31 and engage and connect the first sub 14 to the tool joint 31.

According to the spiral drilling tool assembly of the spiral drilling machine, the first core rod 11 and the second core rod 21 are externally provided with the first spiral blade 12 and the second spiral blade 22, and during drilling, the spiral blades (the first spiral blade 12 or the second spiral blade 22) are used for conveniently discharging slag outwards from the drilled hole. The first core rod 11 and the second core rod 21 are internally provided with a first water flow channel 13 and a second water flow channel 23, water is led into the corresponding water flow channel (the first water flow channel 13 or the second water flow channel 23) while drilling, rock soil in the hole is wetted, and the drilling resistance is reduced.

When the spiral drilling machine is used for drilling, the first drill rod 1 and the drill rod joint 31 can be matched and connected, a small-diameter drill hole is drilled by using the first drill rod 1, then the first drill rod 1 is replaced by the second drill rod 2 on the same spiral drilling machine, and then the small-diameter drill hole is reamed by using the second drill rod 2 to obtain a large-diameter drill hole, so that the spiral drilling machine does not need to be replaced when large-diameter drilling construction is carried out. In addition, after the first drill rod 1 is replaced by the second drill rod 2, the auger machine only needs to move axially along the small-diameter drill hole, and positioning between the second drill rod 2 and the small-diameter drill hole is facilitated.

In the related art, when large-diameter drilling construction is performed, two spiral drilling machines are required to be used for successively and respectively constructing small-diameter drilling and large-diameter drilling. On one hand, the spiral drilling machine and the matched drilling tool need to be replaced in the drilling construction process, so that the construction efficiency is low. On the other hand, when the construction is finished for small-diameter drilling, and the auger drill and the drilling tool are replaced for large-diameter drilling, the positioning of the drilling is difficult, so that the tracks of the large-diameter drilling tool and the small-diameter drilling tool are difficult to be completely consistent, and the problems that the large-diameter drilling is easy to deflect and the precision of a final hole is poor are caused.

Therefore, compared with the related art, when the spiral drilling machine disclosed by the embodiment of the invention is used for large-diameter drilling construction, on one hand, the spiral drilling machine does not need to be replaced, so that the drilling construction efficiency can be improved; on the other hand, the second drill rod 2 and the small-diameter drill hole are accurately positioned, so that the tracks of the large-diameter drill hole and the small-diameter drill hole are more easily consistent, and the problems of deflection and poor final hole precision of the large-diameter drill hole are effectively avoided.

Therefore, the spiral drilling tool assembly has the advantages of high drilling efficiency, good final hole precision and the like.

It will be understood by those skilled in the art that the first drill pipe 1 and the second drill pipe 2 are indicated for illustrative purposes and that the auger assembly may also include various types of drill pipes, such as a third drill pipe, a fourth drill pipe, etc. The plurality of drill rods are distinguished in that the maximum outer diameters of the helical blades are different between the drill rods, whereby a plurality of types of drill rods can meet the drilling requirements of different diameters.

In order to make the technical solution of the present application easier to understand, the technical solution of the present application is further described below by taking as an example that the extending direction of the first core rod 11 coincides with the left-right direction, which is shown in fig. 1.

The first end of the first core bar 11 may be a right end of the first core bar 11, the second end of the first core bar 11 may be a left end of the first core bar 11, the right end of the first core bar 11 is provided with a first joint 14, and a cavity is formed inside the first core bar 11 to form a first water flow channel 13.

The first end of the second core rod 21 may be the right end of the second core rod 21, the second end of the second core rod 21 may be the left end of the second core rod 21, the right end of the second core rod 21 is provided with a second joint 24, and the inside of the second core rod 21 is provided with a cavity to form a second water flow channel 23.

In some embodiments, the root of the first helical blade 12 is welded to the outer circumferential surface of the first core rod 11, and the root of the second helical blade 22 is welded to the outer circumferential surface of the second core rod 21. The first helical blade 12 and the second helical blade 22 are used for spiral deslagging during drilling, and the maximum outer diameter of the first helical blade and the second helical blade is manufactured according to the requirement of drilling hole forming.

In some embodiments, the first sub 14 is mated to the rod sub 31 by a plug-in connection, and the second sub 24 is mated to the rod sub 31 by a plug-in connection.

Thereby, the speed of coupling and uncoupling the second coupling 24 and the drill pipe coupling 31 between the first coupling 14 and the drill pipe coupling 31 can be increased, so that the drilling efficiency can be further increased.

For example, as shown in FIGS. 1-5, the first sub 14 and the second sub 24 may be identically shaped and each may mate with a pipe coupling 31.

In the related art, the torque of the auger drill is large, and therefore, the first core rod 11 and the second core rod 21 need to have sufficient strength. In the case where the first core rod 11 and the second core rod 21 are provided with water flow passages, the first core rod 11 and the second core rod 21 need to have sufficient strength only by increasing the wall thickness of the first core rod 11 and the second core rod 21.

In some embodiments, each of the first and second joints 14 and 24 is an inner eight-way joint.

It will be appreciated that the tool joint 31 is now an outer octave joint, fig. 1, capable of mating with an inner octave joint. Therefore, the first joint 14 and the second joint 24 can be formed by only cutting less materials at the first end of the first core rod 11 and the first end of the second core rod 21, so that the wall thickness of the first joint 14 and the second joint 24 is increased, the structural strength of the first joint 14 and the second joint 24 is increased, and the structural strength of the joint of the first joint 14 and the drill rod joint 31 and the joint of the second joint 24 and the drill rod joint 31 is ensured.

It will be appreciated that the positions of the inner and outer square joints may be interchanged. For example, the tool joint 31 is an inner octagon joint, while each of the first joint 14 and the second joint 24 is an outer octagon joint.

Of course, in other embodiments, the first and second fittings 14, 24 may be female hexagonal fittings, female square fittings, male hexagonal fittings, male square fittings, or the like.

When the connector is used specifically, the outer octagonal connector and the inner octagonal connector can be fixed together by a pin shaft or a bolt. For example, as shown in fig. 4 and 5, a plurality of through holes are provided in the outer octagonal joint. Because the inside of interior eight square joint leads to there is rivers, in order to guarantee the leakproofness, be equipped with a plurality of recesses with the through-hole one-to-one on the outer peripheral face of interior eight square joint, mutually support round pin axle or bolt and through-hole, recess in order to realize outer eight square joint and interior eight square joint's fixed.

In some embodiments, the auger assembly further comprises a small diameter drill bit 16, the small diameter drill bit 16 having a bit connector 161 thereon, the second end of the first core rod 11 having a third connector 15 thereon, the third connector 15 being capable of mating with the bit connector 161.

For example, as shown in fig. 1-5, the right end of the small diameter drill bit 16 is provided with a bit adapter 161, the bit adapter 161 being of the same construction as the first adapter 14. Optionally, the bit sub 161 and the first sub 14 are both outer eight-way sub. At the left end of the first core rod 11, a third joint 15 is provided, the third joint 15 being the same as the drill rod joint 31, optionally both the third joint 15 and the drill rod joint 31 being male joints.

Thereby, the small diameter drill 16 can be detached from the first core 11, thereby facilitating replacement of the small diameter drill 16 on the first core 11.

It should be noted that the small-diameter drill bit 16 is provided with a small hole, and the small hole is communicated with the first water flow channel 13, so that water flow in the first water flow channel 13 can be guided into rock soil.

The first drill rod 1, the drive shaft 3 and the small-diameter drill bit 16 constitute a first drilling tool.

In some embodiments, the first drill rod 1 is provided in plurality, the third joint 15 being able to cooperate with the first joint 14.

For example, as shown in fig. 1-5, the third connector 15 and the first connector 14 can be mated with each other. Therefore, a plurality of first drill rods 1 can be connected together in sequence in the extending direction of the drill rods to form different lengths, so that the drilling requirements of different lengths can be met, and meanwhile, the first drill rods 1 are interchangeable and can be connected in sequence conveniently.

In some embodiments, the auger assembly further comprises a large diameter drill bit 26, a reamer joint 261 being provided on the large diameter drill bit 26, and a fourth joint 25 being provided at the second end of the second core rod 21, the fourth joint 25 being capable of mating with the reamer joint 261.

For example, as shown in FIGS. 7-9, the large diameter drill bit 26 is provided with a reamer adapter 261 and a cavity is provided in the core of the large diameter drill bit 26. The left end of the second core rod 21 is provided with a fourth joint 25, when the second drill rod 2 needs to be utilized for reaming, the fourth joint 25 is matched with the reaming joint 261, and meanwhile, a cavity in the large-diameter drill bit 26 is communicated with the second water flow channel 23 in the second core rod 21; fourth sub 25 is not mated with reamer sub 261 when reaming with second drill pipe 2 is not required. Thereby facilitating installation and replacement of the large diameter drill bit 26.

It should be noted that reamer joint 261 is an inner octagonal joint, and fourth joint 25 is an outer octagonal joint. The large-diameter drill bit 26 is provided with a small hole which is communicated with the second water flow channel 23 and can guide water flow in the second water flow channel 23 into rock soil.

In some embodiments, the second drill rod 2 is provided in plurality, the fourth joint 25 being able to cooperate with the second joint 24.

For example, as shown in fig. 7, the fourth joint 25 and the second joint 24 can be mutually matched, so that a plurality of second drill rods 2 can be connected together in sequence in the extending direction of the second drill rods to form different lengths, so as to meet the drilling requirements of different lengths, and simultaneously meet the interchangeability, so as to replace the second drill rods 2.

In some embodiments, the auger assembly further comprises a guide rod 27, the guide rod 27 being connected to a second end of the large diameter drill bit 26.

For example, as shown in fig. 7, the guide rod 27 is located at the left end of the large-diameter drill bit 26, the left end of the guide rod 27 is tapered, a cavity is formed in the guide rod 27 and can be communicated with the second water flow channel 23, and a small hole is formed in the guide rod 27 and can guide the water flow in the second water flow channel 23 into the rock soil.

Therefore, when the large-diameter drill bit 26 is used for reaming, the large-diameter drill bit 26 can be ensured to ream along the extending direction of the small-diameter drill hole processed by the small-diameter drill bit 16 with the help of the guide rod 27, and the drilling precision can be further improved.

Preferably, the right end of the guide rod 27 is threadedly coupled to the left end of the large diameter drill 26. For example, the left end of the large diameter drill 26 is provided with a screw joint 262, and the right end of the guide rod 27 and the large diameter drill 26 are connected together by the screw joint 262.

Thereby, the attachment and detachment between the guide rod 27 and the large-diameter drill 26 is facilitated.

As shown in fig. 6-9, the second drill rod 2, the drive shaft 3, the large diameter drill bit 26 and the guide rod 27 constitute a second drilling tool.

In some embodiments, the diameter of the first core rod 11 is equal to the diameter of the second core rod 21, and the diameter of the first water flow channel 13 is equal to the diameter of the second water flow channel 23.

For example, as shown in fig. 2 and 8, the first core rod 11 and the second core rod 21 are made of steel pipes having the same diameter, thereby facilitating the design process. The first water flow channel 13 and the second water flow channel 23 have the same hole diameter, are conveniently connected with the drill rod joint 31, and can ensure the stability of water flow.

The first core rod 11 and the second core rod 21 are made of 45 steel seamless tubes, and the core rod of the large-diameter drill 26 and the second core rod 21 have the same diameter and material. The first joint 14, the third joint 15, the second joint 24, the fourth joint 25, the drill rod joint 31, the reaming joint 261 and the drill bit joint 161 are all made of 42CrMnA hardened and tempered steel.

The operation of the auger drilling machine will be described below by taking the first drilling tool and the second drilling tool shown in fig. 1-9 as an example: firstly, the position of a drilled hole is determined, before the drilling begins, the driving shaft 3, the plurality of first drill rods 1 and the small-diameter drill bit 16 are connected in sequence, meanwhile, a water source is communicated with the first water flow channel 13, the power supply of the spiral drilling machine is turned on, and the small-diameter drilling begins to be constructed. And after the small-diameter drilling construction is finished, the water source and the power supply are turned off, the first drill rods 1 and the small-diameter drill bits 16 are dismounted, and the position of the driving shaft 3 is kept unchanged. Then, a plurality of second drill rods 2 are connected with the large-diameter drill bit 26 and the guide rod 27 in sequence, a water source and the second water flow channel 23 are connected, the power supply of the spiral drilling machine is turned on, and the construction and reaming are started.

According to the spiral drilling machine provided by the embodiment of the invention, drill rods with different models can be replaced on the same spiral drilling machine, and drill holes with different diameters are constructed, so that the problem that spiral drilling machines with different models are required for the construction of the original small-diameter drill hole and the large-diameter drill hole is solved, the construction efficiency of the large-diameter drill hole is improved, the double promotion of the hole forming rate and the construction efficiency of the large-diameter drill hole is realized, and the safe and efficient production of a mine is effectively ensured.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless explicitly specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In 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.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.