阅读说明：本技术 一种多工位轮转设备 (Multi-station wheel rotating equipment ) 是由 郁慰 张鹏远 程亚飞 于 2020-04-02 设计创作，主要内容包括：本发明涉及物料输送设备技术领域,具体公开了一种多工位轮转设备,其包括：支架；至少两组导向机构,沿竖直方向间隔设置于支架；多个载具,滑动设置于支架；第一驱动机构,导向机构的两端均设置有第一驱动机构,第一驱动机构用于驱动载具沿竖直方向运动；第二驱动机构,设置于支架,用于驱动载具在导向机构上滑动,以及驱动载具在第二驱动机构和导向机构之间转换。载具的运动形式为水平运动和竖直运动,支架本身不需要转动,因此,取消了滑环的设置,节约了人力和物料,也不会存在偏摆的问题,提高了载具的位置精度。通过在竖直方向间隔设置至少两组导向机构,从而可以利用纵向空间,减小多工位轮转设备在水平方向上的占用空间。(The invention relates to the technical field of material conveying equipment, and particularly discloses multi-station rotating equipment, which comprises: a support; the at least two groups of guide mechanisms are arranged on the bracket at intervals along the vertical direction; the carriers are arranged on the bracket in a sliding manner; the two ends of the guide mechanism are provided with first driving mechanisms respectively, and the first driving mechanisms are used for driving the carriers to move along the vertical direction; and the second driving mechanism is arranged on the bracket and used for driving the carrier to slide on the guide mechanism and driving the carrier to be switched between the second driving mechanism and the guide mechanism. The motion form of carrier is horizontal motion and vertical motion, and support itself need not rotate, consequently, has cancelled the setting of sliding ring, has practiced thrift manpower and material, also can not have the problem of beat, has improved the position accuracy of carrier. Through set up two sets of at least guiding mechanism at vertical direction interval to can utilize vertical space, reduce the occupation space of multistation wheel equipment on the horizontal direction.)

1. A multi-station rotary apparatus, comprising:

a support (1);

at least two groups of guide mechanisms (2) are arranged on the bracket (1) at intervals along the vertical direction;

a plurality of carriers (3) which are arranged on the bracket (1) in a sliding manner;

the two ends of the guide mechanism (2) are provided with the first driving mechanisms (6), and the first driving mechanisms (6) are used for driving the carriers (3) to move along the vertical direction;

the second driving mechanism (4) is arranged on the support (1) and used for driving the carrier (3) to slide on the guide mechanism (2) and driving the carrier (3) to switch between the second driving mechanism (4) and the guide mechanism (2).

2. A multi-station cycle apparatus according to claim 1, wherein the second driving mechanism (4) comprises a mover assembly (43) and a stator, the mover assembly (43) and the stator can realize electromagnetic effect, each carrier (3) is connected with the mover assembly (43), the stator comprises a moving stator (41) and at least two sets of fixed stators (42), at least two sets of fixed stators (42) are arranged on the support (1) and correspond to the guiding mechanisms (2) in a one-to-one manner, and the moving stator (41) is connected to the output end of the first driving mechanism (6) and can be butted with the fixed stators (42).

3. A multi-station cycle apparatus according to claim 2, wherein the stator is a coil and the mover assembly (43) comprises a permanent magnet.

4. A multi-station wheel turning apparatus according to claim 2, wherein the rotor assembly (43) comprises a fixing member (431) and a rotor (432), the carrier (3) is connected to the fixing member (431), the fixing member (431) is provided with a U-shaped groove (433), the rotor (432) is connected to two opposite groove walls of the U-shaped groove (433), and the stator is inserted into the U-shaped groove (433).

5. A multi-station cycle apparatus according to claim 1, further comprising an adsorption mechanism (5), wherein the adsorption mechanism (5) is connected to the carrier (3) for adsorbing the work pieces.

6. A multi-station rotary equipment according to claim 5, wherein the carrier (3) is provided with a suction hole, the suction mechanism (5) comprises a moving component (51) and a first joint (52), the first joint (52) is arranged on the bracket (1) and is communicated with the vacuum generator, the moving component (51) comprises a check valve (511) and a second joint (512), the check valve (511) is communicated with the suction hole, and the second joint (512) can be communicated with the first joint (52).

7. A multi-station cycle plant according to claim 6, characterized in that it comprises a loading station (101) and a blanking station (107), said carriers (3) being movable to said loading station (101) and to said blanking station (107), said first joint (52) being provided on one side of both said loading station (101) and said blanking station (107).

8. A multi-station cycle apparatus according to claim 6, wherein one of the first joint (52) and the second joint (512) is provided with a slot (513), and the other joint is provided with a projection (521), and the projection (521) can be inserted into the slot (513).

9. A multi-station cycle apparatus according to claim 2, wherein the frame (1) is further provided with a position detection assembly for detecting whether the moving stator (41) is docked with the fixed stator (42).

10. A multi-station cycle apparatus according to claim 2, wherein the first drive mechanism (6) comprises a drive member (61), a screw (62) and a nut, the drive member (61) being in driving connection with the screw (62), the nut being threaded onto the screw (62), the moving stator (41) being connected to the nut.

Technical Field

The invention relates to the technical field of material conveying equipment, in particular to multi-station rotating equipment.

Background

In order to save the space occupied by laser cutting equipment, the existing laser cutting equipment adopts a turntable to bear a plurality of materials, and the turntable rotates to enable the materials to flow among stations.

The method is characterized in that a rotating disc is arranged on a rotating shaft, a sliding ring is arranged on the rotating disc, a sliding ring is arranged on the sliding ring, a rotating center of the rotating disc is arranged on the sliding ring, and the sliding ring is arranged on the rotating shaft and is used for driving the rotating disc to rotate in a 360-degree range.

Disclosure of Invention

The invention aims to provide a multi-station wheel rotating device, which is used for reducing the occupied space, reducing the consumption of manpower and materials and improving the position precision of a carrier.

In order to achieve the purpose, the invention adopts the following technical scheme:

a multi-station rotary apparatus comprising:

a support;

the at least two groups of guide mechanisms are arranged on the bracket at intervals along the vertical direction;

the carriers are arranged on the bracket in a sliding manner;

the two ends of the guide mechanism are provided with the first driving mechanisms respectively, and the first driving mechanisms are used for driving the carriers to move along the vertical direction;

and the second driving mechanism is arranged on the bracket and used for driving the carrier to slide on the guide mechanism and driving the carrier to switch between the second driving mechanism and the guide mechanism.

Preferably, the second driving mechanism comprises a rotor assembly and a stator, the rotor assembly and the stator can achieve an electromagnetic effect, each carrier is connected with the rotor assembly, the stator comprises a moving stator and at least two groups of fixed stators, the at least two groups of fixed stators are arranged on the support and correspond to the guide mechanisms one by one, and the moving stator is connected to the output end of the first driving mechanism and can be in butt joint with the fixed stators.

Preferably, the stator is a coil, and the mover assembly includes a permanent magnet.

Preferably, the rotor assembly comprises a fixing piece and a rotor, the carrier is connected with the fixing piece, the fixing piece is provided with a U-shaped groove, the two opposite groove walls of the U-shaped groove are both connected with the rotor, and the stator is inserted in the U-shaped groove.

Preferably, the multi-station wheel equipment further comprises an adsorption mechanism, and the adsorption mechanism is connected with the carrier and used for adsorbing the workpiece.

Preferably, the carrier is provided with an adsorption hole, the adsorption mechanism comprises a movement assembly and a first joint, the first joint is arranged on the support and communicated with the vacuum generator, the movement assembly comprises a check valve and a second joint, the check valve is communicated with the adsorption hole, and the second joint can be communicated with the first joint.

Preferably, the multi-station wheel equipment comprises a feeding station and a discharging station, the carrier can move to the feeding station and the discharging station, and the first joint is arranged on one side of the feeding station and one side of the discharging station.

Preferably, one of the first joint and the second joint is provided with a slot, and the other joint is provided with a projection which can be inserted into the slot.

Preferably, the bracket is further provided with a position detection assembly, and the position detection assembly is used for detecting whether the moving stator is in butt joint with the fixed stator.

Preferably, the first driving mechanism includes a driving member, a screw, and a nut, the driving member is in driving connection with the screw, the nut is screwed to the screw, and the moving stator is connected to the nut.

The invention has the beneficial effects that: the motion form of carrier is horizontal motion and vertical motion, and support itself need not remove, consequently, has cancelled the setting of sliding ring, has practiced thrift manpower and material, also can not have the problem of beat, has improved the position accuracy of carrier. The multistation wheel equipment that this embodiment provided is through setting up two sets of guiding mechanism at vertical direction interval to can utilize vertical space, reduce the occupation space of multistation wheel equipment on the horizontal direction.

Drawings

Fig. 1 is a schematic front view of a multi-station rotary apparatus according to an embodiment of the present invention;

fig. 2 is a perspective view of a multi-station wheel rotating apparatus provided in an embodiment of the present invention;

FIG. 3 is an enlarged view at A in FIG. 2;

FIG. 4 is a schematic structural diagram of a mover assembly provided in an embodiment of the present invention;

fig. 5 is a schematic diagram comparing the occupied space of the multi-station rotary equipment provided by the embodiment of the invention with that of the rotary table in the prior art;

fig. 6 is a schematic structural diagram of an adsorption mechanism according to an embodiment of the present invention.

In the figure:

10. a turntable; 20. multi-station wheel turning equipment;

1. a support;

2. a guide mechanism; 21. fixing a sliding rail;

3. a carrier;

4. a second drive mechanism; 41. a moving stator; 42. fixing the stator; 43. a mover assembly; 431. a fixing member; 432. a mover; 433. u-shaped groove

5. An adsorption mechanism; 51. a motion assembly; 511. a check valve; 512. a second joint; 513. a slot; 52. a first joint; 521. a bump;

6. a first drive mechanism; 61. a drive member; 62. a screw; 63. mounting a plate; 64. a movable slide rail;

7. a slider;

101. a feeding station; 102. aligning to a station before film tearing; 103. a film tearing station; 104. aligning to a station after tearing the film; 105. a laser processing station; 106. a quality detection station; 107. a blanking station; 108. and cleaning the station.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

In the present invention, the directional terms such as "upper", "lower", "left", "right", "inner" and "outer" are used for easy understanding without making a contrary explanation, and thus do not limit the scope of the present invention.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The embodiment provides a multi-station rotating equipment 20, which is used in a laser cutting equipment for cutting O L ED, but is not limited thereto, and can also be used in other equipment which needs to provide a plurality of carriers 3 and make the carriers 3 continuously rotate, so as to reduce the occupied space of the multi-station rotating equipment 20, reduce the consumption of manpower and materials, and improve the position accuracy of the carriers.

As shown in fig. 1 and fig. 2, the multi-station wheel-rotating apparatus 20 provided in the present embodiment includes a bracket 1 and an executing portion, wherein the bracket 1 is used for mounting the executing portion, and the executing portion includes a first driving mechanism 6, a second driving mechanism 4, at least two sets of guiding mechanisms 2, and a plurality of carriers 3 slidably disposed on the bracket 1. At least two sets of guiding mechanism 2 set up in support 1 along vertical direction interval. Preferably, the guiding mechanism 2 is horizontally arranged, the guiding mechanism 2 comprises a fixed sliding rail 21, the fixed sliding rail 21 is connected with the support 1, the carrier 3 is provided with a sliding block 7, the sliding block 7 is provided with a sliding groove, and the sliding block 7 is slidably connected with the fixed sliding rail 21 through the sliding groove. Of course, in other embodiments, the guiding mechanism 2 may also be a sliding slot, and the carrier 3 is provided with a sliding block 7, and the sliding block 7 is slidably disposed in the sliding slot. Preferably, the number of the guide mechanisms 2 is two, the number of the guide mechanisms 2 can also be set according to actual situations, and the number of the guide mechanisms 2 can be three, four or more, and is not limited specifically herein. The guide mechanism 2 may be disposed to be inclined according to specific conditions, and is not particularly limited herein.

As shown in fig. 1, in the present embodiment, the multi-station rotating apparatus 20 is provided with eight stations, which are a feeding station 101, a pre-tearing alignment station 102, a tearing station 103, a post-tearing alignment station 104, a laser processing station 105, a quality detection station 106, a blanking station 107, and a cleaning station 108 for cleaning the carrier 3. A plurality of carriers 3 slide and set up in support 1, and carriers 3 can rotate to guiding mechanism 2 and with guiding mechanism 2 sliding connection to make every carrier 3 homoenergetic stop on each station, and then make manipulator or manual work operate the work piece that is located on carriers 3. Preferably, the number of the carriers 3 is the same as that of the stations, so that the carriers 3 correspond to the stations one by one after the carriers 3 stop moving. Of course, in other embodiments, the number of stations may be more than eight or less than eight according to specific situations, and is not limited specifically herein.

The two ends of the guide mechanism 2 are provided with first driving mechanisms 6, and the first driving mechanisms 6 are used for driving the carrier 3 to move along the vertical direction, so that the carrier 3 can move to the corresponding position with the same height as the guide mechanisms 2 with different heights. The second driving mechanism 4 is disposed on the bracket 1, and is used for sliding the driving carrier 3 on the guiding mechanism 2, and switching the driving carrier 3 between the second driving mechanism 4 and the guiding mechanism 2. Under the action of the first driving mechanism 6 and the second driving mechanism 4, the carrier 3 can realize an annular motion track, and the carrier 3 is continuously recycled.

The motion form of carrier 3 is horizontal motion and vertical motion, and support 1 itself need not remove, consequently, has cancelled the setting of sliding ring, has practiced thrift manpower and material, also can not have the problem of beat, has improved the position accuracy of carrier 3. The multi-station rotary equipment 20 provided by the embodiment can utilize the longitudinal space and reduce the occupied space of the multi-station rotary equipment 20 in the horizontal direction by arranging at least two groups of guide mechanisms 2 at intervals in the vertical direction.

As shown in fig. 1, in the present embodiment, the first driving mechanism 6 may adopt a screw transmission mode, and includes a driving member 61, a screw 62 and a nut, the driving member 61 may be a motor, an output shaft of the motor is connected with the screw 62, and the nut is screwed with the screw 62. Preferably, as shown in fig. 3, the nut is connected to a mounting plate 63, the mounting plate 63 is connected to a movable slide rail 64, an extending direction of the movable slide rail 64 is the same as an extending direction of the fixed slide rails 21, the slider 7 slides along the extending direction of the movable slide rail 64, and the nut slides up and down to drive the movable slide rail 64 to slide up and down, so that the movable slide rail 64 can be respectively butted with any one of the two fixed slide rails 21, thereby improving the stability of the movement of the carrier 3.

As shown in fig. 2 and 3, the second drive mechanism 4 includes a mover assembly 43 and a stator. The mover assembly 43 and the stator can realize an electromagnetic effect, so that the mover assembly 43 can move relative to the stator, and each carrier 3 is connected with the mover assembly 43, so that the mover assembly 43 drives the carrier 3 to move.

The first driving mechanism 6 is used for moving the carrier 3 up and down, so that the carrier 3 rotates on the two sets of guiding mechanisms 2 arranged at intervals up and down, and then, in order to realize the rotation of the carrier 3 between the first driving mechanism 6 and the guiding mechanisms 2, the stator comprises two sets of moving stators 41 and two sets of fixed stators 42, and the two sets of fixed stators 42 are arranged at intervals on the bracket 1 and are arranged in one-to-one correspondence with the guiding mechanisms 2. The two sets of moving stators 41 are respectively connected to the output ends of the two sets of first driving mechanisms 6 and can be butted with the fixed stators 42. Of course, in other embodiments, when the number of the fixed stators 42 is greater than two, the fixed stators 42 are disposed in one-to-one correspondence with the guiding mechanisms 2, and each group of the first driving mechanisms 6 may be connected to one group of the moving stators 41 or each group of the first driving mechanisms 6 may be connected to multiple groups of the moving stators 41 as needed, where each group of the moving stators 41 corresponds to one or more groups of the fixed stators 42.

As shown in fig. 1 and 2, the carrier 3 located at the laser processing station 105 is connected to the first driving mechanism 6, and the next movement step of the carrier 3 is to move to the guiding mechanism 2 located at the upper side. Specifically, the process of moving the carrier 3 from the first driving mechanism 6 to the guiding mechanism 2 is as follows: the first driving mechanism 6 located on the left side of fig. 1 drives the moving stator 41 to move upward to the position shown in fig. 1, so that the moving stator 41 is butted against the fixed stator 42; the electromagnetic effect is generated between the mover assembly 43 and the moving stator 41 on the carrier 3, so that the carrier 3 moves to the right side in fig. 1 and moves to the guide mechanism 2. The mover assembly 43 and the fixed stator 42 on the carrier 3 are controlled to generate an electromagnetic effect, so that the carrier 3 slides or stops on the guide mechanism 2, and the mover assembly 43 drives the carrier 3 to move to each station on the guide mechanism 2. The principle of the carrier 3 moving from the guiding mechanism 2 to the first driving mechanism 6 is the same as the principle of the carrier 3 moving from the first driving mechanism 6 to the guiding mechanism 2, and is not described herein again.

Preferably, a position detection assembly (not shown) is further disposed on the bracket 1, and the position detection assembly is used for detecting whether the moving stator 41 is butted with the fixed stator 42. The multi-station rotation device provided by the present embodiment may further include a controller (not shown) and a power supply (not shown), and the detection assembly, the power supply and the mover assembly 43 are all electrically connected to the controller. When the detection assembly detects that the moving stator 41 is in butt joint with the fixed stator 42, a signal is transmitted to the controller, the controller controls the power supply to supply power to the stator, so that the stator and the rotor assembly 43 generate an electromagnetic effect, and the rotor assembly 43 moves and drives the carrier 3 to move. The detection component can be a limit switch or a position sensor arranged on the bracket 1. The controller may be a centralized or distributed controller, for example, the controller may be a single-chip microcomputer or may be formed by a plurality of distributed single-chip microcomputers, and a control program may be run in the single-chip microcomputers to control the detection assembly, the power supply, and the mover assembly 43 to implement the functions thereof.

As shown in fig. 2, the fixed slide rail 21 of the guide mechanism 2 is preferably arranged in parallel with the fixed stator 42, and the length of the fixed slide rail 21 is preferably the same as the length of the fixed stator 42 so that the fixed slide rail 21 always guides the carrier 3.

Preferably, the stator is a coil and the mover assembly 43 includes a permanent magnet. The existing linear motor generates relative displacement through an electromagnetic effect generated between a permanent magnet and a coil. In general, a permanent magnet is long and a coil is short, and the permanent magnet is fixed and called a stator, and the coil moves relative to the permanent magnet and called a mover. At this time, the cable for supplying power to the coil is connected to the mover, and thus the cable moves along with the mover. In this embodiment, the coil is arranged longer and the magnet is arranged shorter, and the coil is fixed to the support 1 while the permanent magnet moves relative to the coil. Therefore, in the embodiment, the coil is a stator, and the permanent magnet is a rotor. Therefore, in the present embodiment, the fixed stator 42 does not need to move, and the cable connected to the fixed stator 42 does not need to follow the movement, and the cable winding problem does not occur. Since the moving distance of the moving stator 41 is short and the reciprocating motion between two points is performed, the cable with the moving stator 41 is not twisted.

As shown in fig. 4, in the present embodiment, the mover assembly 43 includes a fixing member 431 and a mover 432, the carrier 3 is connected to the fixing member 431, the fixing member 431 is provided with a U-shaped groove 433, two groove walls opposite to the U-shaped groove 433 are both connected with the mover 432, and the stator is inserted in the U-shaped groove 433, so that the stator and the mover assembly 43 generate an electromagnetic effect.

In the present embodiment, each carrier 3 is connected with two mover assemblies 43, the two mover assemblies 43 are disposed on the carrier 3 at intervals, and the opening of the U-shaped groove 433 in the upper mover assembly 43 faces upward to cooperate with the upper fixed stator 42; the U-shaped groove 433 in the mover assembly 43 located at the lower side is opened downward to be engaged with the fixed stator 42 located at the lower side. Of course, in other embodiments, each carrier 3 may also be connected with only one downward opening mover assembly 43 or upward opening mover assembly 43.

As shown in fig. 5, compared with the rotary tables 10 in the prior art, the multi-station rotary apparatus 20 provided in the present embodiment has a slightly increased length direction, but a significantly decreased width direction, so that six to eight multi-station rotary apparatuses 20 can be arranged in the space originally provided with four rotary tables 10, thereby increasing the number of the multi-station rotary apparatuses 20 that can be accommodated without increasing the occupied space of the laser cutting apparatus in the horizontal direction.

A set of actuators is provided on each of the opposite sides of the frame 1. I.e. one bracket 1 supports two sets of actuators. The multi-station rotary apparatus 20 can further reduce the space occupied by multiple multi-station rotary apparatuses 20 when multiple sets of execution parts are required for one laser cutting apparatus.

In order to improve the stability of the workpiece disposed on the carrier 3, the multi-station wheel rotating apparatus 20 further includes an adsorption mechanism 5, and the adsorption mechanism 5 is connected with the carrier 3 and is used for adsorbing the workpiece.

As shown in fig. 6, preferably, the carrier 3 has a suction hole, the suction mechanism 5 includes a moving component 51 and a first joint 52, and the first joint 52 is disposed on the bracket 1 and is communicated with the vacuum generator. The moving assembly 51 includes a check valve 511 and a second connector 512, the check valve 511 is communicated with the adsorption hole, and the second connector 512 can be communicated with the first connector 52. The moving assembly 51 moves together with the carrier 3, and the first joint 52 does not move. Since the first connector 52 is connected to the vacuum generator by the pipe, the first connector 52 is not moved, and thus, the pipe can be prevented from being entangled. In this embodiment, to facilitate the insertion and extraction of the first connector 52 and the second connector 512, the first connector 52 may be a quick-insertion male connector, and the second connector 512 may be a quick-insertion female connector. Of course, in other embodiments, the first connector 52 may be a quick-connect female connector and the second connector 512 may be a quick-connect male connector.

The multi-station wheel equipment 20 comprises a feeding station 101 and a discharging station 107, the carrier 3 can move to the feeding station 101 and the discharging station 107, and a first joint 52 is arranged on one side of each of the feeding station 101 and the discharging station 107. When the carrier 3 is located at the loading station 101 and the workpiece is loaded, the second joint 512 is communicated with the first joint 52 to enable vacuum to be introduced into the adsorption holes, and the vacuum leakage in the adsorption holes after the second joint 512 is separated is prevented through the check valve 511. When the carrier 3 is located at the blanking station 107 and the workpiece is downloaded, the second connector 512 is communicated with the first connector 52, so that positive pressure or atmosphere is introduced into the adsorption holes, and the vacuum environment of the adsorption holes is destroyed.

Preferably, the adsorption hole is connected to the check valve 511 through a pipe, and the check valve 511 is connected to the second connector 512 through a pipe.

The first joint 52 is provided with a projection 521, the second joint 512 is provided with a slot 513, the projection 521 can be inserted into the slot 513, and the arrangement of the projection 521 and the slot 513 can ensure that the first joint 52 and the second joint 512 are accurately butted, so that the phenomenon that vacuum is not introduced into an adsorption hole or the vacuum environment is not damaged sufficiently is avoided. Of course, in other embodiments, the second joint 512 may be provided with a protrusion 521, and the first joint 52 is provided with a slot 513.

Further, the cross-sectional area of the insertion groove 513 is gradually reduced from the open end to the bottom of the groove to provide a guiding function. Preferably, the slot 513 is a conical structure and the insert is also a conical structure.

Support 1 is made by the marble, and support 1's rigid support structure has guaranteed carrier 3's vertical error, has reduced the design and has assembled the degree of difficulty. Of course, in other embodiments, the bracket 1 may be made of metal, such as by casting the bracket 1, or by welding the bracket 1 with steel pipes or plates.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.