阅读说明：本技术 一种航空航天用钛合金板激光切割装置 (Titanium alloy plate laser cutting device for aerospace ) 是由 刘娟 于 2021-09-18 设计创作，主要内容包括：本发明涉及一种切割装置,尤其涉及一种航空航天用钛合金板激光切割装置。一种航空航天用钛合金板激光切割装置,包括有：支撑架,支撑架两侧均连接有安装板和第一固定板；第一连接板,两侧第一固定板顶部一侧均连接有第一连接板；第一导向杆,第一连接板顶部连接有第一导向杆。本发明通过驱动机构中的双轴电机来驱动推料机构中的推板推动钛合金板移动,在推动钛合金板移动的过程中,通过激光切割器来对钛合金板进行切割,从而实现了自动对钛合金板进行切割的效果。(The invention relates to a cutting device, in particular to a titanium alloy plate laser cutting device for aerospace. A titanium alloy plate laser cutting device for aerospace comprises: the two sides of the support frame are both connected with a mounting plate and a first fixing plate; the first connecting plate is connected to one side of the top of the first fixing plate on two sides; the top of the first connecting plate is connected with a first guide rod. According to the invention, the push plate in the material pushing mechanism is driven to push the titanium alloy plate to move by the double-shaft motor in the driving mechanism, and the titanium alloy plate is cut by the laser cutter in the process of pushing the titanium alloy plate to move, so that the effect of automatically cutting the titanium alloy plate is realized.)

1. The utility model provides an aerospace titanium alloy board laser cutting device which characterized in that, including:

the device comprises a support frame (1), wherein both sides of the support frame (1) are connected with a mounting plate (2) and a first fixing plate (3);

the first connecting plate (4) is connected to one side of the top of the first fixing plate (3) on two sides;

the top of the first connecting plate (4) is connected with a first guide rod (5);

the second connecting plate (7) is connected between the first guide rods (5) at two sides in a sliding manner; the first springs (6) are connected between the first spring (6), the second connecting plate (7) and the two first connecting plates (4);

the laser cutter (8) is mounted on the second connecting plate (7), and the laser cutter (8) is used for cutting the titanium alloy plate;

the mounting plate (2) is provided with a material pushing mechanism (9), and the material pushing mechanism (9) is used for pushing the titanium alloy plate to move;

the driving mechanism (10) is arranged between the mounting plate (2) and the support frame (1), and the driving mechanism (10) is used for driving the pushing mechanism (9) to operate.

2. The aerospace titanium alloy plate laser cutting device as claimed in claim 1, wherein the material pushing mechanism (9) comprises:

the mounting plate (2) is connected with a second guide rod (92);

the second guide rod (92) is connected with the connecting block (91) in a sliding mode;

the second spring (93) is connected between the connecting block (91) and the mounting plate (2);

the top of the connecting block (91) is connected with a bidirectional nut (94);

the push plate (95) is connected to the two-way nut (94), and the push plate (95) is used for pushing the titanium alloy plate to move.

3. A laser cutting device for titanium alloy sheets for aerospace according to claim 2, wherein the driving mechanism (10) comprises:

the two sides of the top of the mounting plate (2) are both connected with the second fixing plate (101);

the two-way screw (102) is rotatably connected between the second fixing plates (101) on the two sides of the two-way screw (102), and the two-way nut (94) is in threaded fit with the two-way screw (102);

the double-shaft motor (103) is arranged on the support frame (1);

bevel gears (104) are connected to two output shafts of the double-shaft motor (103) and the two bidirectional screw rods (102), and the bevel gears (104) on the double-shaft motor (103) are meshed with the bevel gears (104) on the bidirectional screw rods (102).

4. The aerospace titanium alloy plate laser cutting device according to claim 3, further comprising a blanking mechanism (11), wherein the blanking mechanism (11) comprises:

the first fixing rods (111), four first fixing rods (111) are arranged, and the four first fixing rods (111) are respectively connected to the tops of the two first fixing plates (3);

the first rotating shafts (113) are respectively and rotatably connected to the two first fixing rods (111);

the other two first fixing rods (111) are respectively and rotatably connected with a second rotating shaft (114);

the blanking plate (112) is connected to the first rotating shaft (113) and the second rotating shaft (114), and the blanking plate (112) is used for placing a titanium alloy plate;

the lower part of the first rotating shaft (113) and the lower part of the second rotating shaft (114) are both connected with a belt pulley (117);

a flat belt (118), wherein the flat belt (118) is wound between the belt pulley (117) on the first rotating shaft (113) and the belt pulley (117) on the second rotating shaft (114);

the second rotating shaft (114) is connected with a one-way gear (115);

the top of the push plate (95) is connected with a first rack (116), and the first rack (116) is meshed with the one-way gear (115).

5. The aerospace titanium alloy plate laser cutting device according to claim 4, further comprising a clamping mechanism (12), wherein the clamping mechanism (12) comprises:

the third guide rod (123) is connected with the first connecting plate (4) in a sliding mode;

the bottom of the third guide rod (123) is connected with a pressure plate (121), and the pressure plate (121) is used for limiting the titanium alloy plate;

the third connecting plate (122) is connected to the pressing plate (121);

the third spring (124) is connected between the pressure plate (121) and the first connecting plate (4); the two sides of the bottom of the first rack (116) are both connected with the deflector rod (125), and the deflector rod (125) is matched with the third connecting plate (122).

6. The aerospace titanium alloy plate laser cutting device according to claim 5, further comprising a lifting mechanism (13), wherein the lifting mechanism (13) comprises:

the upper parts of the first connecting plates (4) on two sides of the third fixing plate (131) are connected with the third fixing plate (131); the third rotating shaft (132), the third fixing plate (131) is rotatably connected with the third rotating shaft (132), and the third rotating shaft (132) is connected with a transmission gear (133) and a crank (135);

the top of the pressing plate (121) is connected with a second rack (134), and the second rack (134) is meshed with the transmission gear (133);

fourth connecting plate (136), second connecting plate (7) top both sides all are connected with fourth connecting plate (136), and fourth connecting plate (136) and crank (135) cooperation.

7. The aerospace titanium alloy plate laser cutting device according to claim 6, further comprising a blocking mechanism (14), wherein the blocking mechanism (14) comprises:

the second fixing rods (141), wherein the second fixing rods (141) are connected to the two first fixing rods (111) in a sliding manner;

the first baffle (142) is connected to the second fixing rod (141);

the other two first fixing rods (111) are respectively and rotatably connected with a rotating rod (143);

the second baffle (144) is connected to the rotating rod (143);

the sliding rod (145) is connected between the two second baffles (144) in a sliding manner.

8. The aerospace titanium alloy plate laser cutting device of claim 7, wherein the slide bar (145) is detachably arranged, and the slide bar (145) is used for fixing the two second baffle plates (144).

Technical Field

The invention relates to a cutting device, in particular to a titanium alloy plate laser cutting device for aerospace.

Background

The titanium alloy plate is an important plate used for manufacturing in the aerospace industry in the modern society, and when the titanium alloy plate is processed and manufactured, the titanium alloy plate is generally required to be subjected to laser cutting.

At present, the mode of carrying out laser cutting to titanium alloy board is usually placed the titanium alloy board on laser cutting machine by the manual work, and after finishing placing, promote the titanium alloy board again and remove and cut through laser cutting machine, above-mentioned mode needs the manual work to promote the titanium alloy board when the operation usually, comparatively consumes the manpower to when cutting, can not carry on spacingly to the titanium alloy board, lead to the titanium alloy board easily and rock the influence cutting.

Therefore, it is necessary to design a laser cutting device for an aerospace titanium alloy plate, which can save labor during operation and can limit the position of the titanium alloy plate during cutting.

Disclosure of Invention

(1) Technical problem to be solved

In order to overcome the defects that the titanium alloy plate is pushed manually in the operation process, the labor is consumed, the titanium alloy plate cannot be limited in the cutting process, and the titanium alloy plate is prone to shaking and affecting the cutting, the invention provides the laser cutting device for the titanium alloy plate for aerospace, which can save the labor in the operation process and can limit the titanium alloy plate in the cutting process.

(2) Technical scheme

In order to solve the technical problem, the invention provides a laser cutting device for a titanium alloy plate for aerospace, which comprises a support frame, wherein two sides of the support frame are both connected with a mounting plate and a first fixing plate; the first connecting plate is connected to one side of the top of the first fixing plate on two sides; the top of the first connecting plate is connected with a first guide rod; the second connecting plate is connected between the first guide rods on the two sides in a sliding manner; the first springs are connected between the second connecting plate and the two first connecting plates; the laser cutter is mounted on the second connecting plate and used for cutting the titanium alloy plate; the mounting plate is provided with a pushing mechanism, and the pushing mechanism is used for pushing the titanium alloy plate to move; and the driving mechanism is arranged between the mounting plate and the support frame and is used for driving the pushing mechanism to operate.

Preferably, the pushing mechanism comprises a second guide rod, and the mounting plate is connected with the second guide rod; the second guide rod is connected with the connecting block in a sliding manner; the second spring is connected between the connecting block and the mounting plate; the top of the connecting block is connected with a bidirectional nut; the push plate is connected to the bidirectional nut and used for pushing the titanium alloy plate to move.

Preferably, the driving mechanism comprises a second fixing plate, and the two sides of the top of the mounting plate are both connected with the second fixing plate; the two-way screw is rotatably connected between the second fixing plates on the two sides, and the two-way nut is in threaded fit with the two-way screw; the support frame is provided with the double-shaft motor; the bevel gears are connected to two output shafts of the double-shaft motor and the two bidirectional screw rods, and the bevel gears on the double-shaft motor are meshed with the bevel gears on the bidirectional screw rods.

Preferably, the blanking device further comprises a blanking mechanism, wherein the blanking mechanism comprises four first fixing rods, and the four first fixing rods are respectively connected to the tops of the two first fixing plates; the two first fixing rods are respectively connected with a first rotating shaft in a rotating mode; the other two first fixing rods are rotatably connected with a second rotating shaft; the first rotating shaft and the second rotating shaft are connected with blanking plates, and the blanking plates are used for placing titanium alloy plates; the lower parts of the first rotating shaft and the second rotating shaft are connected with belt pulleys; the flat belt is wound between the belt pulley on the first rotating shaft and the belt pulley on the second rotating shaft; the second rotating shaft is connected with a one-way gear; the top of the push plate is connected with a first rack which is meshed with the one-way gear.

Preferably, the clamping mechanism comprises a third guide rod, and the first connecting plate is connected with the third guide rod in a sliding manner; the bottom of the third guide rod is connected with a pressing plate, and the pressing plate is used for limiting the titanium alloy plate; the pressing plate is connected with a third connecting plate; the third spring is connected between the pressing plate and the first connecting plate; the two sides of the bottom of the first rack are both connected with a shifting lever, and the shifting lever is matched with the third connecting plate.

Preferably, the lifting mechanism comprises a third fixing plate, and the upper parts of the first connecting plates on two sides are connected with the third fixing plate; the third rotating shaft is rotatably connected to the third fixing plate, and a transmission gear and a crank are connected to the third rotating shaft; the top of the pressing plate is connected with a second rack which is meshed with the transmission gear; and both sides of the top of the second connecting plate are connected with fourth connecting plates, and the fourth connecting plates are matched with the crank.

Preferably, the device further comprises a blocking mechanism, wherein the blocking mechanism comprises second fixing rods, and the second fixing rods are connected to the two first fixing rods in a sliding manner; the second fixing rod is connected with a second baffle; the other two first fixing rods are respectively and rotatably connected with a rotating rod; the rotating rod is connected with a second baffle; and a sliding rod is connected between the two second baffles in a sliding manner.

Preferably, the slide bar is detachably arranged and used for fixing the two second baffles.

(3) The invention has the beneficial effects that:

1. according to the invention, the push plate in the material pushing mechanism is driven by the double-shaft motor in the driving mechanism to push the titanium alloy plate to move, and the titanium alloy plate is cut by the laser cutter in the process of pushing the titanium alloy plate to move, so that the effect of automatically cutting the titanium alloy plate is realized, and the titanium alloy plate is not required to be manually pushed when being cut, so that the labor is effectively saved.

2. When the laser cutting machine is used for carrying out laser cutting on the titanium alloy plate, the titanium alloy plate can be limited through the pressing plate in the clamping mechanism, so that the effect of limiting the titanium alloy plate and avoiding the titanium alloy plate from shaking to influence the cutting is achieved.

3. According to the invention, the titanium alloy plate is added through the blanking mechanism, and the titanium alloy plate does not need to be frequently placed manually, so that the labor is further saved.

Drawings

Fig. 1 is a schematic perspective view of the present invention.

Fig. 2 is a schematic partial perspective view of a first embodiment of the present invention.

Fig. 3 is a second partial perspective view of the present invention.

Fig. 4 is a schematic perspective view of the pushing mechanism of the present invention.

Fig. 5 is a schematic partial perspective view of the pushing mechanism of the present invention.

Fig. 6 is a schematic perspective view of the driving mechanism of the present invention.

Fig. 7 is a partial perspective view of the driving mechanism of the present invention.

Fig. 8 is a schematic perspective view of the blanking mechanism of the present invention.

Fig. 9 is a schematic partial perspective view of the blanking mechanism of the present invention.

Fig. 10 is a perspective view of the clamping mechanism of the present invention.

Fig. 11 is a schematic perspective view of a portion of the clamping mechanism of the present invention.

Fig. 12 is a schematic perspective view of the ascending mechanism according to the present invention.

Fig. 13 is a partial perspective view of the lifting mechanism of the present invention.

Fig. 14 is a schematic perspective view of the blocking mechanism of the present invention.

Fig. 15 is a schematic perspective view of a portion of the blocking mechanism of the present invention.

The labels in the figures are: 1-support frame, 2-mounting plate, 3-first fixing plate, 4-first connecting plate, 5-first guide bar, 6-first spring, 7-second connecting plate, 8-laser cutter, 9-pushing mechanism, 91-connecting block, 92-second guide bar, 93-second spring, 94-two-way nut, 95-push plate, 10-driving mechanism, 101-second fixing plate, 102-two-way screw, 103-two-axis motor, 104-bevel gear, 11-blanking mechanism, 111-first fixing rod, 112-blanking plate, 113-first rotating shaft, 114-second rotating shaft, 115-one-way gear, 116-first rack, 117-belt pulley, 118-flat belt, 12-clamping mechanism, 121-a pressing plate, 122-a third connecting plate, 123-a third guide rod, 124-a third spring, 125-a deflector rod, 13-a lifting mechanism, 131-a third fixing plate, 132-a third rotating shaft, 133-a transmission gear, 134-a second rack, 135-a crank, 136-a fourth connecting plate, 14-a blocking mechanism, 141-a second fixing rod, 142-a first baffle, 143-a rotating rod, 144-a second baffle and 145-a sliding rod.

Detailed Description

The invention is further described below with reference to the figures and examples.

Example 1

A laser cutting device for titanium alloy plates for aerospace, which is shown in figures 1-7 and comprises a support frame 1, a mounting plate 2, a first fixing plate 3, a first connecting plate 4 and a first guide rod 5, first spring 6, second connecting plate 7, laser cutter 8, pushing equipment 9 and actuating mechanism 10, support frame 1 left and right sides is equallyd divide and is connected with mounting panel 2 and first fixed plate 3 respectively, first fixed plate 3 is located the 2 outsides of mounting panel, 3 top front sides of the first fixed plate in both sides all are connected with first connecting plate 4, 4 tops of first connecting plate are connected with first guide bar 5, slidingtype connection has second connecting plate 7 between the first guide bar 5 in both sides, all be connected with first spring 6 between second connecting plate 7 and two first connecting plates 4, install laser cutter 8 on the second connecting plate 7, be equipped with pushing equipment 9 on the mounting panel 2, be equipped with actuating mechanism 10 between mounting panel 2 and the support frame 1.

The material pushing mechanism 9 comprises a connecting block 91, a second guide rod 92, a second spring 93, a two-way nut 94 and a push plate 95, the second guide rod 92 is connected to the mounting plate 2, the connecting block 91 is connected to the second guide rod 92 in a sliding mode, the second spring 93 is connected between the connecting block 91 and the mounting plate 2, the two-way nut 94 is connected to the top of the connecting block 91, and the push plate 95 is connected to the two-way nut 94.

The driving mechanism 10 comprises second fixing plates 101, two-way screws 102, a double-shaft motor 103 and bevel gears 104, the front side and the rear side of the top of the mounting plate 2 are connected with the second fixing plates 101, the two-way screws 102 are rotatably connected between the two corresponding front and rear second fixing plates 101, the two-way nuts 94 are in threaded fit with the two-way screws 102, the double-shaft motor 103 is installed on the rear side of the support frame 1, the bevel gears 104 are respectively connected to the two output shafts of the double-shaft motor 103 and the rear sides of the two-way screws 102, and the bevel gears 104 on the double-shaft motor 103 and the bevel gears 104 on the two-way screws 102 are meshed with each other.

When the titanium alloy plate needs to be subjected to laser cutting, the device can be used, firstly, a user can place the titanium alloy plate between the two side mounting plates 2, then the user can start the double-shaft motor 103 to drive the two-way screw rods 102 to rotate through the bevel gear 104, the two-way screw rods 102 rotate to drive the two-way nuts 94 to move backwards, after the two-way nuts 94 move backwards to the limit, the two-way screw rods 102 continue to rotate to drive the two-way nuts 94 to move forwards, the two-way nuts 94 drive the push plate 95 to move together when moving, when the two-way nuts 94 drive the push plate 95 to move forwards to be contacted with the titanium alloy plate, the titanium alloy plate can be pushed to move forwards, at the moment, the second connecting plate 7 can be pulled to drive the laser cutter 8 to move upwards, the first spring 6 is stretched, when the titanium alloy plate moves to the position below the laser cutter 8, the second connecting plate 7 can be loosened, under the action of the first spring 6, can make laser cutter 8 remove downwards, at this moment, can start laser cutter 8 and cut the titanium alloy board, after two-way nut 94 moved forward to the limit, laser cutter 8 also accomplished the cutting of titanium alloy board, at this moment two-way screw 102 continues to rotate and drives two-way nut 94 and remove the reseing backward, can place the titanium alloy board again afterwards and cut, so relapse, just can cut the titanium alloy board, after the cutting is accomplished, it can to close double-shaft motor 103, two-way nut 94 drives connecting block 91 and removes together when moving in the front and back, second spring 93 plays the cushioning effect.

Example 2

On the basis of embodiment 1, as shown in fig. 1, 8 and 9, the blanking device 11 further includes a blanking mechanism 11, the blanking mechanism 11 includes a first fixing rod 111, a blanking plate 112, a first rotating shaft 113, a second rotating shaft 114, a one-way gear 115, a first rack 116, a flat belt 118 and a belt pulley 117, the two first fixing rods 111 are connected to the rear side of the top of the first fixing plate 3, the two first fixing rods 111 are arranged in front and rear, the first rotating shaft 113 is rotatably connected to the two first fixing rods 111 on the front side, the second rotating shaft 114 is rotatably connected to the two first fixing rods 111 on the rear side, the blanking plate 112 is connected to the first rotating shaft 113 and the second rotating shaft 114, the belt pulley 117 is connected to the lower portions of the first rotating shaft 113 and the second rotating shaft 114, the flat belt 118 is wound between the belt pulley 117 on the first rotating shaft 113 and the belt pulley 117 on the second rotating shaft 114, the one-way gear 115 is connected to the second rotating shaft 114, the top of the push plate 95 is connected with a first rack 116, and the first rack 116 is meshed with the one-way gear 115.

When titanium alloy plates are placed, a plurality of titanium alloy plates can be respectively inserted between different gaps on four blanking plates 112, when the bidirectional nut 94 drives the push plate 95 to move backwards, the push plate 95 drives the first rack 116 to move backwards together, the first rack 116 drives the one-way gear 115 to rotate when moving backwards, the one-way gear 115 rotates to drive the second rotating shaft 114 to rotate, the second rotating shaft 114 rotates to drive the first rotating shaft 113 to rotate through the belt pulley 117 and the flat belt 118, the first rotating shaft 113 and the second rotating shaft 114 drive the blanking plate 112 to rotate when rotating, the blanking plate 112 conveys the titanium alloy plates downwards when rotating, when the first rack 116 moves backwards to the limit, the blanking plate 112 just sends the lowermost titanium alloy plate down, at the moment, the lowermost titanium alloy plate falls between the two mounting plates 2, then the push plate 95 moves forwards to push the titanium alloy plates, at the moment, the first rack 116 moves forwards to poke the one-way gear 115 to rotate reversely, because the one-way gear 115 is arranged in a one-way mode, the one-way gear 115 cannot drive the second rotating shaft 114 to rotate when rotating in the reverse direction, and therefore the titanium alloy plate does not need to be placed frequently manually, and manpower is effectively saved.

As shown in fig. 1, 10 and 11, the clamping device 12 further includes a clamping mechanism 12, the clamping mechanism 12 includes a pressing plate 121, a third connecting plate 122, a third guide rod 123, a third spring 124 and a shift lever 125, the first connecting plate 4 is slidably connected with the third guide rod 123, the bottom of the third guide rod 123 is connected with the pressing plate 121, the third spring 124 is connected between the pressing plate 121 and the first connecting plate 4, the pressing plate 121 is connected with the third connecting plate 122, the shift lever 125 is connected to both the front and rear sides of the bottom of the first rack 116, and the shift lever 125 is matched with the third connecting plate 122.

When the first rack 116 moves back and forth, the driving lever 125 is driven to move back and forth, when the driving lever 125 moves forward to be in contact with the third connecting plate 122, the driving lever 125 continues to move forward to push the third connecting plate 122 to move downwards, the third connecting plate 122 moves downwards to drive the pressing plate 121 to move downwards, the third spring 124 is stretched, and the pressing plate 121 can limit the titanium alloy plate after moving downwards, so that the cutting is prevented from being influenced by sloshing when the titanium alloy plate is subjected to laser cutting.

Example 3

On the basis of the embodiment 2, as shown in fig. 1, 12 and 13, the lifting mechanism 13 is further included, the lifting mechanism 13 includes a third fixing plate 131, a third rotating shaft 132, a transmission gear 133, a second rack 134, a crank 135 and a fourth connecting plate 136, the upper portion of the front side of the left first connecting plate 4 and the upper portion of the rear side of the right first connecting plate 4 are both connected with the third fixing plate 131, the third fixing plate 131 is rotatably connected with the third rotating shaft 132, the third rotating shaft 132 is respectively connected with the transmission gear 133 and the crank 135, the crank 135 is located inside the transmission gear 133, the left side and the right side of the top of the second connecting plate 7 are both connected with the fourth connecting plate 136, the fourth connecting plate 136 is matched with the crank 135, the top of the pressing plate 121 is connected with the second rack 134, and the second rack 134 is meshed with the transmission gear 133.

The clamp plate 121 drives the second rack 134 to move downwards when moving downwards, the second rack 134 moves downwards to poke the transmission gear 133 to rotate, the transmission gear 133 rotates to drive the third rotating shaft 132 to rotate, the third rotating shaft 132 rotates to drive the crank 135 to rotate, after the crank 135 rotates to contact with the fourth connecting plate 136, the crank 135 continues to rotate to push the fourth connecting plate 136 to move upwards, the fourth connecting plate 136 drives the second connecting plate 7 to move upwards when moving upwards, thereby driving the laser cutter 8 to move upwards, and therefore, the second connecting plate 7 does not need to be pulled manually to drive the laser cutter 8 to move upwards, and manpower is effectively saved.

As shown in fig. 1, 14 and 15, the blocking device 14 further includes a blocking mechanism 14, the blocking mechanism 14 includes a second fixing rod 141, a first baffle 142, a rotating rod 143, a second baffle 144 and a sliding rod 145, the two first fixing rods 111 on the front side are both slidably connected with the second fixing rod 141, the second fixing rod 141 is connected with the first baffle 142, the two first fixing rods 111 on the rear side are both rotatably connected with the rotating rod 143, the rotating rod 143 is connected with the second baffle 144, and the sliding rod 145 is slidably connected between the two second baffles 144.

The sliding rod 145 is detachably disposed, and the sliding rod 145 is used for fixing the two second baffles 144.

After the titanium alloy plate is added between the four blanking plates 112, the titanium alloy plate can be blocked through the matching of the first baffle 142 and the second baffle 144, the titanium alloy plate is prevented from sliding off, when the titanium alloy plate needs to be added, the sliding rod 145 can be drawn out, the rotating rod 143 is twisted to drive the second baffle 144 to stop the two blanking plates 112 on the rear side, the titanium alloy plate can be added later, after the titanium alloy plate is added, the rotating rod 143 is twisted to drive the second baffle 144 to reset, and then the sliding rod 145 is inserted between the two second baffles 144.

The above examples are merely representative of preferred embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, various changes, modifications and substitutions can be made without departing from the spirit of the present invention, and these are all within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.