Opening and closing structure of universal feeding frame for substrate packaging preassembled sizing material

Abstract

The invention discloses an opening and closing structure of a universal feeding frame for substrate packaging preassembled sizing materials, which is mounted on a frame body and comprises a plurality of left telescopic rods, a plurality of right telescopic rods, a left control beam and a right control beam, the right ends of the plurality of left telescopic rods are respectively fixed on the left sides of a plurality of left half discs, and the right ends of the plurality of right telescopic rods are respectively fixed on the right sides of a plurality of right half discs; the left ends of the multiple right telescopic rods penetrate through a left through groove of the left side beam and a pipe hole of a tubular cross shaft of the left telescopic frame to stretch out, and the multiple right telescopic rods are installed on the left control beam in a front-back sliding mode; the right end penetrates through a right through groove of the right side beam and a pipe hole of a tubular cross shaft of the right side telescopic frame, extends out and can be mounted on a right control beam in a front-back sliding manner; the left control beam and the right control beam move back to back at the same time by applying acting force, and the left control beam and the right control beam move oppositely at the same time by applying the acting force, so that all the left half plates and the corresponding right half plates are separated and clamped. The device has the advantages that the free row pitch of the opening and closing discs can be realized, and meanwhile, all the opening and closing discs can be synchronously opened and closed without being interfered by a row pitch mechanism.

Description

Technical Field

[0001] The invention relates to an opening and closing structure of a universal loading rack for pre-installed adhesive material for substrate packaging, belonging to the technical field of chip packaging. Background Art

[0002] After the chip is mounted on the substrate, it needs to be injection molded and packaged in the mold. Generally, a number of chips are mounted in rows and columns on a substrate. During injection molding, the substrate with the chips mounted is placed in the mold cavity, and then heated and injected. The glue (epoxy resin) used for injection molding is initially a short cylindrical shape, generally with a diameter of more than ten millimeters and a height of about twenty millimeters. On the upper mold of the mold, there is a row of feed holes (POT) set at equal intervals. There are generally 8 or 9 feed holes in a row. Before heating and injection molding, 8 or 9 columnar glues need to be filled into the feed holes respectively, and then pressed into the mold runner into the mold cavity after being melted at high temperature.

[0003] Put the columnar rubber into the feed hole. In a non-automated (robot) processing workshop, manual filling is required. In order to increase the discharge speed, the traditional practice in the industry is to use a pre-loading device, which is provided with pre-loading holes whose number is consistent with the number of feed holes on the upper mold, and a support plate is arranged under the pre-loading holes. Now the pre-loading device is placed above the upper mold so that each pre-loading hole is located directly above the corresponding feed hole, and then the columnar rubber is placed in the pre-loading hole, and then the support plate is removed so that the columnar rubber falls into the corresponding feed holes at the same time.

[0004] The drawback of the above method is that the pre-installed holes are fixed and cannot be changed according to the spacing of the mold feed holes. Therefore, it is often necessary to prepare pre-installed devices with various pre-installed hole spacings, which undoubtedly increases the purchase cost of the pre-installed devices.

[0005] To solve the above problems, the patent document with application number 202211377354.9 discloses a dual-axis adjustable spacing glue cake picking and placing head device and a semiconductor plastic packaging machine, including a sliding seat, a guide post and a guide sleeve, a spacing adjustment component and a clamping claw group, the guide post is slidably connected to the sliding seat, and the guide sleeve is rotatably connected to the guide post, the guide post and the guide sleeve are used to realize the lifting and rotation of the picking and placing head, the spacing adjustment component includes an adjusting frame, a scissor rod group and a ball screw, the adjusting frame is rotatably connected to the guide sleeve, the ball screw is rotatably connected to the adjusting frame, the scissor rod group is connected to the nut of the ball screw, and can be extended and retracted following the rotation of the screw, the clamping claw group includes multiple pneumatic clamps, the pneumatic clamps are connected to the scissor rod group, and can be equidistantly adjusted along with the extension and retraction of the scissor rod group, so that the glue cake picking and placing head device can clamp the glue cakes on barrels with different spacings and place the glue cakes on lead frames with different placement methods.

[0006] The defect of the technical solution provided by the patent document is that multiple pneumatic grippers cannot accurately grab one from the scattered columnar rubber materials at the same time. The columnar rubber materials to be grabbed need to be placed accurately under the corresponding grippers first, and then grabbed by the grippers and moved to the corresponding position and then put down. This is actually equivalent to adding a procedure of grabbing and moving the grabbed columnar rubber materials to just above the corresponding position, which greatly reduces the loading speed. At the same time, the setting of the grippers requires the installation of a pneumatic device and multiple air supply pipelines, which complicates the device. Summary of the invention

[0007] In order to design a universal loading device that can quickly adjust the radiotherapy spacing according to needs and overcome the technical defects of the solutions disclosed in the above patent documents, our company has developed a universal loading rack for pre-loading glue before substrate packaging (a patent application was filed on the same day as this application). The loading rack involves an opening and closing plate that can be opened and closed by sandwiching two half plates for placing and dropping solid glue, and further involves an opening and closing structure that can make the opening and closing plate separate back to back and sandwiched towards each other. The opening and closing structure is required to be able to quickly realize automatic opening and closing while meeting the free and equidistant spacing of multiple opening and closing plates. There are design difficulties and it is a key technical part to ensure that the universal loading rack achieves its target function.

[0008] The technical problem to be solved by the present invention is: how to achieve synchronous opening and closing of all opening and closing disks while meeting the requirement of free and equidistant spacing of multiple opening and closing disks.

[0009] In view of the above problems, the technical solution proposed by the present invention is: The invention discloses an opening and closing structure of a universal loading rack for pre-installed adhesive material for substrate packaging, which is installed on a rack body and comprises a plurality of left telescopic rods, a plurality of right telescopic rods, a left control beam and a right control beam. The right ends of the plurality of left telescopic rods are respectively fixed to the left sides of a plurality of left half-disks, the left ends extend through the left through slot of the left beam and the tube hole of the tubular cross axis of the left telescopic rack and are installed on the left control beam in a manner that they can slide back and forth. The left ends of the plurality of right telescopic rods are respectively fixed to the right sides of a plurality of right half-disks, the right ends extend through the right through slot of the right beam and the tube hole of the tubular cross axis of the right telescopic rack and are installed on the right control beam in a manner that they can slide back and forth. The separation and clamping of all left half-disks and corresponding right half-disks are achieved by applying a force to make the left control beam and the right control beam move back to back at the same time and applying a force to make the left control beam and the right control beam move towards each other at the same time.

[0010] The opening and closing structure also includes rectangular frames whose number corresponds to the number of opening and closing disks. The opening and closing disks are arranged in the rectangular frames. The left telescopic rod and the right telescopic rod pass through the left end wall and the right end wall of the rectangular frame respectively.

[0011] The opening and closing structure also includes a left sleeve and a right sleeve, which are respectively fixed at the left end and the right end of the rectangular frame. The left sleeve passes through the left through slot of the left beam to the left and is then sleeved into the tube hole of the tubular cross axis of the left telescopic frame. The left telescopic rod is sleeved into the tube hole of the left sleeve, and the left end of the left telescopic rod extends out from the left end of the left sleeve. The right sleeve passes through the right through slot of the right beam to the right and is then sleeved into the tube hole of the tubular cross axis of the right telescopic frame. The right telescopic rod is sleeved into the tube hole of the right sleeve, and the right end of the right telescopic rod extends out from the right end of the right sleeve.

[0012] The right side of the left control beam and the left side of the right control beam are respectively provided with a T-shaped groove composed of a horizontal groove and a vertical groove, the left end of the left telescopic rod and the right end of the right telescopic rod respectively have a rectangular flange protruding radially outward, the left end of the left telescopic rod and the right end of the right telescopic rod are respectively inserted into the T-shaped grooves of the left control beam and the right control beam and can slide in the T-shaped grooves, and the rectangular flanges of the left end of the left telescopic rod and the right end of the right telescopic rod are located in the vertical groove.

[0013] The opening and closing structure also includes a left outer beam arranged outside the left side of the left control beam and a right outer beam arranged outside the right side of the right control beam.

[0014] The opening and closing structure also includes a left opening and closing spring and a right opening and closing spring. The left opening and closing spring is compressed between the left outer beam and the left control beam, and the right opening and closing spring is compressed between the right outer beam and the right control beam, so that the left half disk and the right half disk are closed into an opening and closing disk.

[0015] The opening and closing structure also includes electromagnets arranged on the left outer beam and the right outer beam. The left control beam and the right outer beam are iron beams. The electromagnets on the left outer beam and the right outer beam that are energized can form attractive forces on the left control beam and the right outer beam respectively, so that the left control beam and the right outer beam can simultaneously overcome the elastic resistance of the left opening and closing spring and the right opening and closing spring respectively and separate in their backs.

[0016] The opening and closing structure is arranged on the left outer beam and the right outer beam, and the electromagnets are arranged on the right side of the left outer beam and the left side of the right outer beam respectively.

[0017] Pneumatic cylinders are respectively arranged on the left outer beam and the right outer beam. The pneumatic cylinder on the left outer beam is connected to the left control beam through a piston rod, and the pneumatic cylinder on the right outer beam is connected to the right control beam through a piston rod. By controlling the extension and contraction of the pneumatic cylinder piston rod, the left control beam and the right control beam are moved back to back or towards each other, so that the opening and closing disks are separated or clamped.

[0018] A horizontal left guide rod and a horizontal right guide rod are respectively arranged on the left side of the left beam of the frame and the right side of the right beam. The left control beam and the right control beam are respectively provided with guide holes. The left control beam and the right control beam are respectively installed on the left guide rod and the right guide rod through their respective guide holes. Beneficial Effects

[0019] 1. While being able to realize the free spacing of the opening and closing disks, it can also make all the opening and closing disks open and close synchronously without being interfered by the spacing mechanism; 2. The opening and closing operations of the opening and closing disk are simple and quick. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional schematic diagram of a universal loading rack in Example 1; Figure 2 for Figure 1 A partial schematic diagram of Figure 3 for Figure 1 Schematic diagram of the decomposition; Figure 4 for Figure 3 A partial schematic diagram of Figure 5 This is a three-dimensional schematic diagram of the opening and closing disk of the first embodiment installed in a rectangular frame; Figure 6 It is a cross-sectional schematic diagram of the left side of the universal loading rack described in Example 1; Figure 7 It is a three-dimensional schematic diagram of the universal loading rack described in the second embodiment; Figure 8 for Figure 7 A partial schematic diagram of .

[0021] In the figure: 1, frame; 101, left side beam; 1011, left through slot; 102, right side beam; 1021, right through slot; 2, opening and closing disk; 201, left half disk; 202, right half disk; 203, disk cavity; 3, rectangular frame; 4, telescopic frame; 401, tubular cross axis; 5, left control beam; 6, right control beam; 7, T-shaped slot; 701, horizontal slot; 702, vertical slot; 8, left sleeve; 9, right sleeve; 10, left telescopic rod; 11, right telescopic rod; 12, rectangular flange; 13, left opening and closing spring; 14, right opening and closing spring; 15, left outer beam; 16, right outer beam; 17, left guide rod; 18, right guide rod; 19, electromagnet; 20, pneumatic cylinder; 21, piston rod. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1

[0023] like Figure 1 , 3As shown in Figure 5, a universal loading rack for pre-installed adhesive for substrate packaging has a rack body 1, the rack body 1 has a left beam 101 and a right beam 102, and the left beam 101 and the right beam 102 are respectively provided with a left through groove 1011 and a right through groove 1021 that are connected to each other. A plurality of opening and closing trays 2 for pre-installed adhesive are arranged between the left beam 101 and the right beam 102, and each opening and closing tray 2 is composed of a left half tray 201 and a right half tray 202. On the left side of the left beam 101 and the right side of the right beam 102, scissor-type telescopic racks 4 are symmetrically arranged, which are used to arrange the opening and closing trays 2 in the rack body 1 at equal intervals as needed.

[0024] like Figure 1 , 2 6 shows an opening and closing structure of a universal loading rack for pre-installed adhesive material for substrate packaging, which is installed on a rack body 1 and includes a plurality of left telescopic rods 10, a plurality of right telescopic rods 11, a left control beam 5 and a right control beam 6. The right ends of the plurality of left telescopic rods 10 are respectively fixed to the left sides of the plurality of left half-plates 201, and the left ends extend through the left through slots 1011 of the left beam 101 and the tube holes of the tubular cross shaft 401 of the left telescopic rack 4 and are installed on the left control beam 5 so as to be slidable forward and backward. The left ends of the plurality of right telescopic rods 11 are respectively fixed to the plurality of right half-plates 201. On the right side of the right half disk 202, the right end of the right half disk 201 extends through the right through slot 1021 of the right beam 102 and the tube hole of the tubular cross shaft 401 of the right telescopic frame 4 and is installed on the right control beam 6 to slide forward and backward. By applying a force to make the left control beam 5 and the right control beam 6 move backward at the same time and applying a force to make the left control beam 5 and the right control beam 6 move toward each other at the same time, the separation and clamping of all left half disks 201 and the corresponding right half disk 202 are realized. The left half disk 201 and the corresponding right half disk 202 are clamped to form an opening and closing disk 2 with a disk cavity 203. In this way, while the opening and closing disks 2 can be freely spaced, all the opening and closing disks 2 can be synchronously separated and closed without being interfered by the spacing mechanism.

[0025] like Figure 1 , 5 As shown, the opening and closing structure also includes a rectangular frame 3 corresponding to the number of the opening and closing disks 2, and the opening and closing disks 2 are arranged in the rectangular frame 3, and the left telescopic rod 10 and the right telescopic rod 11 respectively pass through the left end wall and the right end wall of the rectangular frame 3. The arrangement of the rectangular frame 3 makes the opening and closing disk 2 composed of the left half disk 201 and the right half disk 202 have integrity, which is convenient for spacing and meets the opening and closing requirements.

[0026] The opening and closing structure also includes a left sleeve 8 and a right sleeve 9, which are fixed at the left and right ends of the rectangular frame 3, respectively. The left sleeve 8 passes through the left through slot 1011 of the left beam 101 to the left and then is sleeved into the tube hole of the tubular cross shaft 401 of the left telescopic frame 4. The left telescopic rod 10 is sleeved into the tube hole of the left sleeve 8, and its left end extends out from the left end of the left sleeve 8. The right sleeve 9 passes through the right through slot 1021 of the right beam 102 to the right and then is sleeved into the tube hole of the tubular cross shaft 401 of the right telescopic frame 4. The right telescopic rod 11 is sleeved into the tube hole of the right sleeve 9, and its right end extends out from the right end of the right sleeve 9. In this way, the opening and closing plate 2 is stably installed on the frame body to accept the telescopic spacing of the telescopic frame 4, and at the same time, the left telescopic rod 10 and the right telescopic rod 11 can be stretched left and right without interference from external structures.

[0027] like Figure 4 , 5 As shown in Figures 6, a T-shaped groove 7 consisting of a horizontal groove 701 and a vertical groove 702 is respectively provided on the right side of the left control beam 5 and the left side of the right control beam 6, and the left end of the left telescopic rod 10 and the right end of the right telescopic rod 11 respectively have a rectangular flange 12 protruding radially outward, and the left end of the left telescopic rod 10 and the right end of the right telescopic rod 11 are respectively inserted into the T-shaped groove 7 of the left control beam 5 and the right control beam 6 and can slide in the T-shaped groove 7, and the rectangular flange 12 of the left end of the left telescopic rod 10 and the right end of the right telescopic rod 11 is located in the vertical groove 702, one is to implement left and right limit of the left telescopic rod 10 and the right telescopic rod 11, and the other is to prevent the left telescopic rod 10 and the right telescopic rod 11 from rotating.

[0028] To prevent the rectangular frame 3 from rotating, an anti-rotation structure is set between the left telescopic rod 10 and the left sleeve 8 and between the right telescopic rod 11 and the right sleeve 9, such as a conventional ridge axially arranged outside the rod body and a groove axially arranged inside the tube wall to accommodate the ridge, and the ridge can slide axially in the groove.

[0029] like Figure 1 , 3 As shown, the opening and closing structure further includes a left outer beam 15 arranged outside the left side of the left control beam 5 and a right outer beam 16 arranged outside the right side of the right control beam 6.

[0030] like Figure 1 , 2 As shown in Figures 3, 4 and 6, the opening and closing structure also includes a left opening and closing spring 13 and a right opening and closing spring 14. The left opening and closing spring 13 is compressed between the left outer beam 15 and the left control beam 5, and the right opening and closing spring 14 is compressed between the right outer beam 16 and the right control beam 6, so that the left half disk 201 and the right half disk 202 can automatically close into the opening and closing disk 2.

[0031] The opening and closing structure also includes an electromagnet 19 disposed on the left outer beam 15 and the right outer beam 16. The left control beam 5 and the right outer beam 16 are iron beams. The electromagnet 19 on the left outer beam 15 and the right outer beam 16 can respectively form an attraction force on the left control beam 5 and the right outer beam 16, so that the left control beam 5 and the right outer beam 16 can simultaneously overcome the elastic resistance of the left opening and closing spring 13 and the right opening and closing spring 14 and separate in opposite directions. When in use, only the power button for charging the electromagnet 19 needs to be pressed.

[0032] The electromagnets 19 disposed on the left outer beam 15 and the right outer beam 16 are disposed on the right side of the left outer beam 15 and the left side of the right outer beam 16. In this way, the electromagnet 19 on the left side can be made closer to the left control beam 5 to increase the attraction force on the left control beam 5, and the electromagnet 19 on the right side can be made closer to the right control beam 6 to increase the attraction force on the right control beam 6.

[0033] Furthermore, a horizontal left guide rod 17 and a right guide rod 18 are respectively provided on the left side of the left beam 101 and the right side of the right beam 102 of the frame body 1, and guide holes are respectively provided on the left control beam 5 and the right control beam 6. The left control beam 5 and the right control beam 6 are respectively installed on the left guide rod 17 and the right guide rod 18 through their respective guide holes. In this way, the left control beam 5 and the right control beam 6 can smoothly slide left and right on the left guide rod 17 and the right guide rod 18. Embodiment 2

[0034] like Figure 7 , 8 As shown, the difference from the first embodiment lies in that: the universal loading rack is provided with pneumatic cylinders 20 on the left outer beam 15 and the right outer beam 16 respectively, the pneumatic cylinder 20 on the left outer beam 15 is connected to the left control beam 5 through a piston rod 21, and the pneumatic cylinder 20 on the right outer beam 16 is connected to the right control beam 6 through a piston rod 21, and the left control beam 5 and the right control beam 6 are moved back to back or towards each other by controlling the extension and retraction of the piston rod 21 of the pneumatic cylinder 20, so that the opening and closing disk 2 is separated or clamped.

[0035] The above embodiments are only used to more clearly describe the present invention and cannot be regarded as limiting the protection scope of the present invention. Any modifications in equivalent forms should be regarded as falling within the protection scope of the present invention.

Claims

1. An opening and closing structure of a universal loading rack for pre-installed adhesive material for substrate packaging, characterized in that: The invention is installed on a frame body (1), and comprises a plurality of left telescopic rods (10), a plurality of right telescopic rods (11), a left control beam (5) and a right control beam (6). The right ends of the plurality of left telescopic rods (10) are respectively fixed to the left sides of the plurality of left half-plates (201), and the left ends extend through the left through slots (1011) of the left beam (101) and the tube holes of the tubular cross shafts (401) of the left telescopic frame (4) and are installed on the left control beam (5) so as to be able to slide forward and backward. The left ends of the plurality of right telescopic rods (11) are respectively fixed to the left sides of the plurality of left half-plates (201). On the right side of the plurality of right half-disks (202), the right ends extend through the right through slot (1021) of the right beam (102) and the tube hole of the tubular cross shaft (401) of the right telescopic frame (4) and are mounted on the right control beam (6) so as to be able to slide forward and backward. By applying a force to make the left control beam (5) and the right control beam (6) move backwards at the same time and applying a force to make the left control beam (5) and the right control beam (6) move towards each other at the same time, the separation and clamping of all the left half-disks (201) and the corresponding right half-disks (202) are achieved.

2. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 1 is characterized in that: It also comprises rectangular frames (3) whose number corresponds to the number of the opening and closing disks (2), the opening and closing disks (2) being arranged in the rectangular frames (3), and the left telescopic rod (10) and the right telescopic rod (11) respectively passing through the left end wall and the right end wall of the rectangular frame (3).

3. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 2 is characterized in that: The invention also comprises a left sleeve (8) and a right sleeve (9), wherein the left sleeve (8) and the right sleeve (9) are respectively fixed to the left end and the right end of the rectangular frame (3); the left sleeve (8) passes through the left through slot (1011) of the left beam (101) to the left and is then sleeved into the tube hole of the tubular cross shaft (401) of the left telescopic frame (4); the left telescopic rod (10) is sleeved into the tube hole of the left sleeve (8), and the left end of the left telescopic rod (10) protrudes from the left end of the left sleeve (8); the right sleeve (9) passes through the right through slot (1021) of the right beam (102) to the right and is then sleeved into the tube hole of the tubular cross shaft (401) of the right telescopic frame (4); the right telescopic rod (11) is sleeved into the tube hole of the right sleeve (9), and the right end of the right telescopic rod (11) protrudes from the right end of the right sleeve (9).

4. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 1 is characterized in that: The right side of the left control beam (5) and the left side of the right control beam (6) are respectively provided with a T-shaped groove (7) consisting of a horizontal groove (701) and a vertical groove (702); the left end of the left telescopic rod (10) and the right end of the right telescopic rod (11) are respectively provided with a rectangular flange (12) protruding radially outward; the left end of the left telescopic rod (10) and the right end of the right telescopic rod (11) are respectively inserted into the T-shaped groove (7) of the left control beam (5) and the right control beam (6) and are able to slide in the T-shaped groove (7); the rectangular flanges (12) of the left end of the left telescopic rod (10) and the right end of the right telescopic rod (11) are located in the vertical groove (702).

5. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 4 is characterized in that: It also includes a left outer beam (15) arranged outside the left side of the left control beam (5) and a right outer beam (16) arranged outside the right side of the right control beam (6).

6. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 5, characterized in that: It also includes a left opening and closing spring (13) and a right opening and closing spring (14), wherein the left opening and closing spring (13) is compressed between the left outer beam (15) and the left control beam (5), and the right opening and closing spring (14) is compressed between the right outer beam (16) and the right control beam (6), so that the left half disk (201) and the right half disk (202) are closed to form an opening and closing disk (2).

7. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 6, characterized in that: The invention also includes an electromagnet (19) disposed on the left outer beam (15) and the right outer beam (16). The left control beam (5) and the right outer beam (16) are iron beams. The electromagnet (19) on the left outer beam (15) and the right outer beam (16) is energized and can form an attractive force on the left control beam (5) and the right outer beam (16) respectively, so that the left control beam (5) and the right outer beam (16) can simultaneously overcome the elastic resistance of the left opening and closing spring (13) and the right opening and closing spring (14) and separate in opposite directions.

8. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 7, characterized in that: The electromagnets (19) arranged on the left outer beam (15) and the right outer beam (16) are arranged on the right side of the left outer beam (15) and the left side of the right outer beam (16), respectively.

9. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to claim 5, characterized in that: A pneumatic cylinder (20) is provided on the left outer beam (15) and the right outer beam (16), respectively. The pneumatic cylinder (20) on the left outer beam (15) is connected to the left control beam (5) via a piston rod (21), and the pneumatic cylinder (20) on the right outer beam (16) is connected to the right control beam (6) via a piston rod (21). By controlling the extension and retraction of the piston rod (21) of the pneumatic cylinder (20), the left control beam (5) and the right control beam (6) are moved in opposite directions or towards each other, so that the opening and closing disc (2) is separated or clamped.

10. The opening and closing structure of the universal loading rack for substrate packaging pre-installed adhesive according to any one of claims 1 to 9, characterized in that: A horizontal left guide rod (17) and a horizontal right guide rod (18) are respectively provided on the left side of the left beam (101) and the right side of the right beam (102) of the frame body (1), and guide holes are respectively provided on the left control beam (5) and the right control beam (6), and the left control beam (5) and the right control beam (6) are respectively mounted on the left guide rod (17) and the right guide rod (18) through their respective guide holes.

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