RF chip test electromagnetic shielding box

Abstract

The present invention discloses an electromagnetic shielding box for testing radio frequency chips, which belongs to the field of electromagnetic shielding boxes. The present invention comprises a shielding box body, a bearing plate body is arranged inside the shielding box body, a hollow screw tube is connected to the right side of the shielding box body through a rotating shaft, the right end of the hollow screw tube extends to the inside of the shielding box body, and a threaded sleeve is connected to the outer wall through a thread, a fixed block is fixedly connected to the front right side of the inside of the shielding box body, the outer wall of the fixed block is connected to a concave piece through a rotating shaft, and an inclined abutment sheet is fixedly connected to the rear surface of the concave piece; the bearing plate body is used to place the radio frequency chip, and can slide along the shielding box body, and together form a radio frequency chip protection shell, which is plugged into the inner side of the snap-fit ​​seat through the plug-in box on the cover plate, and can be snapped into the inside of the snap-fit ​​port through the snap-fit ​​block, so that the cover plate can cover the shielding box body, realize the closed shielding effect of the radio frequency chip, and facilitate subsequent testing.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic shielding boxes, in particular to an electromagnetic shielding box for radio frequency chip testing. Background Art

[0002] Electromagnetic shielding box is a shielding body of various shapes such as shells, plates, and sleeves made of conductive or magnetic materials. It is a metal body that limits electromagnetic capabilities within a certain space range to suppress radiation interference, and processes conduction and radiation to provide a non-interference test environment for the wireless communication equipment under test.

[0003] Patent Publication No. (CN217564011U) discloses a 5G radio frequency chip shielding device, which relates to the technical field of radio frequency chip matching devices. The utility model includes a radio frequency carrying structure, the top of the radio frequency carrying structure is connected to the limited shielding structure, both sides of the limited shielding structure are provided with matching locking connection structures, the bottom of the matching locking connection structure penetrates the limited shielding structure and is matched with the radio frequency carrying structure, and the radio frequency carrying structure includes a circuit board, a chip body, a matching hole and a locking hole, the inside of the four ends of the circuit board are provided with matching holes, the inner side of the circuit board is provided with a locking hole, and the top of the circuit board is fixedly connected with the chip body. The utility model makes it easy to shield the radio frequency chip through the coordinated design of the radio frequency carrying structure, the limited shielding structure and the matching locking connection structure, and to complete the elastic limit of the chip, and to complete the convenient matching and connecting of the overall shielding device, which greatly improves the convenience of use;

[0004] In the above technology, it is inconvenient to open the box, and it is not convenient to adjust the clamping according to the different thickness of the chip. The applicability is small. In addition, when opening the box to take out the chip, the RF mounting structure and the limiting shielding structure need to be separated. The integrated effect is poor and needs to be improved. For this reason, we proposed an electromagnetic shielding box for RF chip testing. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a device for stably clamping a chip; another purpose of the present invention is to provide a device for facilitating the removal of a chip.

[0006] Technical solution: An electromagnetic shielding box for radio frequency chip testing, comprising a shielding box body, a bearing plate body is arranged inside the shielding box body, a hollow spiral tube is rotatably connected to the right side of the shielding box body through a rotating shaft, the right end of the hollow spiral tube extends to the inside of the shielding box body, and a threaded sleeve is threadedly connected to the outer wall, a fixed block is fixedly connected to the front of the right side of the inside of the shielding box body, the outer wall of the fixed block is rotatably connected to a concave piece through a rotating shaft, an inclined abutment piece is fixedly connected to the rear surface of the concave piece, a rear end of the inclined abutment piece is located on the outside of the threaded sleeve and a notch is provided, the inner upper surface and the inner lower surface of the notch are both rotatably connected to a rotating column through a rotating shaft, and the opposite ends of the two rotating columns are rotatably connected to the outer wall of the threaded sleeve through a rotating shaft;

[0007] The front of the upper surface of the bearing plate body is provided with two through-type slide grooves 1, and a slider 1 is slidably connected inside the slide groove 1. A through-type slide groove 2 is provided at the rear of the upper surface of the bearing plate body, and two sliders 2 are slidably connected inside the slide groove 2. A clamping plate is fixedly connected to the upper surfaces of the slider 1 and the slider 2 which are opposite to each other front and back, and a push block is fixedly connected to the bottom end of the slider 2 located on the right inside the slide groove 2, and the right side of the push block contacts the left side of the inclined abutment piece.

[0008] Furthermore, the bottom of the slider 1 is located below the supporting plate body and is fixedly connected to a rack 1, the lower surface of the supporting plate body is located between the two racks 1 and is fixedly connected to a gear 1, the gear 1 is meshed with the rack 1, and a spring 4 is fixedly connected between the slider 1 and the slide groove 1.

[0009] Furthermore, the shielding box body is symmetrically provided with anti-slip grooves, and anti-slip blocks are fixedly connected to the insides of the two anti-slip grooves at the rear of both sides of the bearing plate body.

[0010] Furthermore, two transmission wheels are rotatably connected to the lower left side of the interior of the shielding box through a rotating shaft, and the outer side walls of the two transmission wheels are commonly connected to a transmission belt. Gear 2 is fixedly connected to the right side of the transmission wheel located at the front of the interior of the shielding box, and rack 2 is fixedly connected to the left side of the lower surface of the supporting plate, and gear 2 is meshingly connected to rack 2.

[0011] Furthermore, the right side of the transmission wheel at the rear of the shielding box is fixedly connected to a hollow tube, the interior of the hollow tube and the interior of the hollow spiral tube are slidably connected to a rotating rod, the outer wall of the rotating rod is located at the opposite ends of the hollow spiral tube and the hollow tube and is fixedly connected to two abutment plates, the right end of the rotating rod passes through the right end of the hollow spiral tube and is fixedly connected to a knob.

[0012] Furthermore, a limiting plate is provided on the outer wall of the rotating rod between the two abutment plates, a fixing bar is fixedly connected to the lower surface of the shielding box, a guide rod is slidably connected to the inside of the fixing bar, the right end of the guide rod is fixedly connected to the limiting bar, a limiting groove is provided on the top of the limiting bar on the outside of the limiting plate, and a spring is fixedly connected between the fixing bar and the limiting bar.

[0013] Furthermore, a snap-fit ​​seat is fixedly connected to the inner upper surface of the shielding box, and snap-fit ​​openings are provided on both sides of the inner side of the snap-fit ​​seat.

[0014] Furthermore, the front surface of the bearing plate body is fixedly connected to a cover plate, the rear surface of the cover plate is fixedly connected to a plug-in box, the interior of the plug-in box is slidably connected to two movable pieces, the opposite sides of the two movable pieces are fixedly connected to locking blocks, the opposite ends of the two locking blocks respectively pass through the front surface and the rear surface of the plug-in box, a spring 2 is fixedly connected between the two movable pieces, and the locking seat is adapted to the plug-in box.

[0015] Furthermore, a locking box is fixedly connected to the front surface of the cover plate, a locking block is slidably connected to the interior of the locking box, the rear end of the locking block passes through the interior of the plug-in box, and the outer side wall is in contact with the opposite sides of the two movable sheets, a plurality of springs are fixedly connected between the locking block and the locking box, a hand-held rod is rotatably connected to the inner upper surface of the locking box via a rotating shaft, a traction rope is fixedly connected between the hand-held rod and the locking block, the bottom end of the hand-held rod passes through the bottom of the locking box, and a rubber sleeve is fixedly connected to the outer side wall.

[0016] Beneficial effects:

[0017] The carrier plate is used to place the RF chip and can slide along the shielding box to form a RF chip protection shell. The carrier plate is plugged into the inner side of the snap-fit ​​seat through the plug-in box on the cover plate, and can be snapped into the inside of the snap-fit ​​port through the snap-fit ​​block, so that the cover plate can cover the shielding box to achieve a closed shielding effect of the RF chip, which is convenient for subsequent testing.

[0018] Under normal conditions, the locking block will be against the two movable pieces, so that the engaging block cannot be retracted toward the inside of the plug-in box. Therefore, when the plug-in box is engaged or pulled out into the engaging seat, it is necessary to rotate the hand-held rod to pull the locking block away from the movable piece. At this time, the plug-in box can be engaged into the engaging seat or pulled out from the engaging seat. This method can facilitate the cover plate to open and pull out the bearing plate body, and can ensure that the cover plate is not easy to open when it covers the shielding box body.

[0019] The adjustable inclined abutment sheet has different inclinations, which controls the relative movement range of the clamping plates to be different, thereby facilitating the clamping of chips of different sizes. After the carrier plate is pulled out, the two clamping plates are automatically separated under the push of the spring 4, making it easy to remove the chip.

[0020] By holding the knob and pushing it forward or backward, the two abutment plates abut against the hollow spiral tube or the hollow tube. At this time, turning the knob can control the rotation of the hollow spiral tube or the hollow tube, thereby facilitating the adjustment of the inclination of the inclined abutment sheet or controlling the bearing plate to slide along the inside of the shielding box body.

[0021] Under normal conditions, under the pull of spring 1, the two contact plates will be away from the hollow screw tube and the hollow tube respectively, to avoid the hollow screw tube or the hollow tube from being rotated when the rotating rod is rotated by accidentally touching the knob. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the left side inside the shielding box of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the right side inside the shielding box of the present invention;

[0025] Figure 4 It is a schematic diagram of the connection structure of the bearing plate body, the transmission belt, the inclined abutment sheet and the rotating rod of the present invention;

[0026] Figure 5 It is a bottom view structural schematic diagram of the bearing plate body of the present invention;

[0027] Figure 6 It is a schematic diagram of the connection structure of the inclined abutment sheet, the concave member and the threaded sleeve of the present invention;

[0028] Figure 7 It is a schematic diagram of the internal structure of the plug-in box of the present invention;

[0029] Figure 8 is a schematic diagram of a side view of a vertical cross-section of a connection structure of a hand-held rod and a locking box of the present invention;

[0030] Fig. 9 The present invention Figure 4 A is an enlarged structural diagram of FIG.

[0031] In the figure: 1, shielding box; 2, bearing plate; 3, hollow screw tube; 4, threaded sleeve; 5, fixed block; 6, concave member; 7, inclined abutment sheet; 8, notch; 9, rotating column; 10, slide groove 1; 11, slider 1; 12, slide groove 2; 13, slider 2; 14, clamping plate; 15, push block; 16, rack 1; 17, gear 1; 18, anti-slip groove; 19, anti-slip block; 20, transmission wheel; 21, transmission belt; 22, gear 2; 23, rack 2; 24, Hollow tube; 25. Rotating rod; 26. Abutment plate; 27. Knob; 28. Limiting plate; 29. ​​Fixing strip; 30. Guide rod; 31. Limiting strip; 32. Limiting groove; 33. Spring one; 34. Snap-fit ​​seat; 35. Snap-fit ​​mouth; 36. Cover plate; 37. Plug-in box; 38. Snap-fit ​​block; 39. Spring two; 40. Locking box; 41. Locking block; 42. Spring three; 43. Hand-held rod; 44. Towing rope; 45. Rubber sleeve; 46. Movable sheet; 47. Spring four. DETAILED DESCRIPTION

[0032] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, an electromagnetic shielding box for radio frequency chip testing is provided, including a shielding box body 1, a bearing plate body 2 is arranged inside the shielding box body 1, anti-slip grooves 18 are symmetrically opened inside the shielding box body 1, and anti-slip blocks 19 are fixedly connected to the inside of the two anti-slip grooves 18 at the rear of both sides of the bearing plate body 2;

[0035] The carrier plate 2 is used to place the radio frequency chip and can slide along the shielding box 1 to form a radio frequency chip protection shell.

[0036] like Figure 7 and Figure 8 As shown, a snap-fit ​​seat 34 is fixedly connected to the inner upper surface of the shielding box 1, snap-fit ​​openings 35 are provided on both sides of the inner part of the snap-fit ​​seat 34, a cover plate 36 is fixedly connected to the front surface of the bearing plate body 2, a plug-in box 37 is fixedly connected to the rear surface of the cover plate 36, two movable pieces 46 are slidably connected to the inner part of the plug-in box 37, and snap-fit ​​blocks 38 are fixedly connected to the opposite sides of the two movable pieces 46, and the opposite ends of the two snap-fit ​​blocks 38 respectively penetrate the front surface and the rear surface of the plug-in box 37, a spring 2 39 is fixedly connected between the two movable pieces 46, and the snap-fit ​​seat 34 is adapted to the plug-in box 37;

[0037] The plug-in box 37 on the cover plate 36 is plugged into the inner side of the snap-fit ​​seat 34, and the snap-fit ​​block 38 can be snapped into the inside of the snap-fit ​​opening 35, so that the cover plate 36 can cover the shielding box 1, achieving a closed shielding effect of the RF chip, which is convenient for subsequent testing;

[0038] The front surface of the cover plate 36 is fixedly connected with a locking box 40, and a locking block 41 is slidably connected inside the locking box 40. The rear end of the locking block 41 penetrates into the interior of the plug-in box 37, and the outer side wall is in contact with the opposite sides of the two movable pieces 46. A plurality of springs 42 are fixedly connected between the locking block 41 and the locking box 40. A hand-held rod 43 is rotatably connected to the upper surface of the inner part of the locking box 40 through a rotating shaft. A traction rope 44 is fixedly connected between the hand-held rod 43 and the locking block 41. The bottom end of the hand-held rod 43 penetrates the bottom of the locking box 40, and a rubber sleeve 45 is fixedly connected to the outer side wall.

[0039] Under normal conditions, under the push of spring three 42, the locking block 41 will abut between the two movable pieces 46, so that the locking block 38 cannot shrink toward the inside of the plug-in box 37. Therefore, when the plug-in box 37 is engaged or pulled out to the inside of the engaging seat 34, it is necessary to rotate the hand-held rod 43, and by winding the traction rope 44, pull the locking block 41 away from the movable piece 46. At this time, the plug-in box 37 can be engaged into the inside of the engaging seat 34, or pulled out from the inside of the engaging seat 34. This method can facilitate the cover 36 to open and pull out the bearing plate body 2, while ensuring that the cover 36 is not easy to open when covering the shielding box body.

[0040] like Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the right side of the shielding box 1 is rotatably connected with a hollow spiral tube 3 through a rotating shaft, the right end of the hollow spiral tube 3 extends to the interior of the shielding box 1, and the outer wall is threadedly connected with a threaded sleeve 4, and the front of the inner right side of the shielding box 1 is fixedly connected with a fixed block 5, the outer wall of the fixed block 5 is rotatably connected with a concave part 6 through a rotating shaft, and the rear surface of the concave part 6 is fixedly connected with an inclined abutment piece 7, and the rear end of the inclined abutment piece 7 is located on the outer side of the threaded sleeve 4 and is provided with a recess 8, and the inner upper surface and the inner lower surface of the recess 8 are rotatably connected with a rotating column 9 through a rotating shaft, and the opposite ends of the two rotating columns 9 are rotatably connected to the outer wall of the threaded sleeve 4 through a rotating shaft, and two through-type slide grooves 10 are provided in the front of the upper surface of the bearing plate body 2, and the inner part of the slide groove 10 A slider 11 is slidably connected, a through-type slide groove 12 is provided at the rear of the upper surface of the bearing plate body 2, two sliders 13 are slidably connected inside the slide groove 12, a clamping plate 14 is fixedly connected to the upper surfaces of the sliders 11 and 13 facing each other, a push block 15 is fixedly connected to the bottom end of the slider 13 located on the right inside the slide groove 12, the right side of the push block 15 contacts the left side of the inclined abutment piece 7, the bottom of the slider 11 is located below the bearing plate body 2 and is fixedly connected to a rack 16, the lower surface of the bearing plate body 2 is located between the two racks 16 and is fixedly connected to a gear 17, the gear 17 is meshed with the rack 16, and a spring 47 is fixedly connected between the slider 11 and the slide groove 10;

[0041] By rotating the hollow screw tube 3, the inclination of the inclined abutment sheet 7 can be adjusted, so that when the chip placed on the upper surface of the carrier plate body 2 slides toward the inside of the shielding box body 1, the push block 15 contacts the inclined abutment sheet 7, and under the meshing action of the rack 16 and the gear 17, the two clamping plates 14 can be controlled to move relative to each other, so as to facilitate clamping the chip. According to the different inclinations of the adjusted inclined abutment sheet 7, the relative movement range of the clamping plates 14 can be controlled to be different, which is convenient for clamping chips of different sizes. After the carrier plate body 2 is pulled out, the two clamping plates 14 are automatically separated under the push of the spring four 47, so as to facilitate the removal of the chip.

[0042] Two transmission wheels 20 are rotatably connected to the lower left side of the shielding box 1 through a rotating shaft, and the outer walls of the two transmission wheels 20 are commonly connected to a transmission belt 21 for transmission. A gear 22 is fixedly connected to the right side of the transmission wheel 20 located in the front of the shielding box 1, and a rack 23 is fixedly connected to the left side of the lower surface of the bearing plate 2, and the gear 22 is meshed with the rack 23. A hollow tube 24 is fixedly connected to the right side of the transmission wheel 20 at the rear of the shielding box 1, and a rotating rod 25 is slidably connected to the inside of the hollow tube 24 and the inside of the hollow spiral tube 3. The outer wall of the rotating rod 25 is located at the opposite ends of the hollow spiral tube 3 and the hollow tube 24 and is fixedly connected to two abutment plates 26. The right end of the rotating rod 25 penetrates to the right end of the hollow spiral tube 3 and is fixedly connected to a knob 27.

[0043] When the hollow tube 24 rotates, the second gear 22 is controlled to rotate under the transmission of the transmission belt 21, and the gear 22 is meshed with the second rack 23 to control the movement of the bearing plate 2. The two abutment plates 26 abut against the hollow spiral tube 3 or the hollow tube 24 by pushing the knob 27 forward or backward. At this time, the knob 27 is turned to control the rotation of the hollow spiral tube 3 or the hollow tube 24, so as to adjust the inclination of the inclined abutment sheet 7 or control the bearing plate 2 to slide along the inside of the shielding box body 1.

[0044] The outer wall of the rotating rod 25 is provided with a limit plate 28 between the two abutment plates 26, the lower surface of the shielding box 1 is fixedly connected with a fixing bar 29, the inside of the fixing bar 29 is slidably connected with a guide rod 30, the right end of the guide rod 30 is fixedly connected with a limit bar 31, the top of the limit bar 31 is located on the outer side of the limit plate 28 and a limit groove 32 is provided, and a spring 33 is fixedly connected between the fixing bar 29 and the limit bar 31;

[0045] Under normal conditions, under the pull of the spring 1 33 , the two contact plates 26 will be away from the hollow spiral tube 3 and the hollow tube 24 , respectively, to avoid the hollow spiral tube 3 or the hollow tube 24 being driven to rotate when the rotating rod 25 is driven to rotate by mistake when the knob 27 is touched.

[0046] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An electromagnetic shielding box for testing radio frequency chips, comprising a shielding box body (1), characterized in that: A bearing plate (2) is arranged inside the shielding box (1); a hollow spiral tube (3) is rotatably connected to the right side of the shielding box (1) via a rotating shaft; the right end of the hollow spiral tube (3) extends into the interior of the shielding box (1), and the outer wall is threadedly connected to a threaded sleeve (4); a fixing block (5) is fixedly connected to the front right side of the interior of the shielding box (1); the outer wall of the fixing block (5) is rotatably connected to a concave member (6) via a rotating shaft; the rear surface of the concave member (6) is fixedly connected to an inclined abutment sheet (7); a rear end of the inclined abutment sheet (7) is located on the outer side of the threaded sleeve (4) and is provided with a recess (8); the inner upper surface and the inner lower surface of the recess (8) are both rotatably connected to a rotating column (9) via a rotating shaft; the opposite ends of the two rotating columns (9) are rotatably connected to the outer wall of the threaded sleeve (4) via a rotating shaft; Two through-type slide grooves (10) are provided in front of the upper surface of the bearing plate body (2), and a slider (11) is slidably connected inside the slide groove (10). A through-type slide groove (12) is provided at the rear of the upper surface of the bearing plate body (2), and two sliders (13) are slidably connected inside the slide groove (12). A clamping plate (14) is fixedly connected to the upper surfaces of the sliders (11) and (13) facing each other. A push block (15) is fixedly connected to the bottom end of the slider (13) located on the right inside the slide groove (12), and the right side of the push block (15) contacts the left side of the inclined abutment sheet (7). A snap-fit ​​seat (34) is fixedly connected to the inner upper surface of the shielding box (1), and snap-fit ​​openings (35) are provided on both sides of the inner side of the snap-fit ​​seat (34); The front surface of the bearing plate body (2) is fixedly connected to a cover plate (36), the rear surface of the cover plate (36) is fixedly connected to a plug-in box (37), the plug-in box (37) is internally slidably connected to two movable plates (46), the opposite sides of the two movable plates (46) are fixedly connected to locking blocks (38), the opposite ends of the two locking blocks (38) respectively penetrate the front surface and the rear surface of the plug-in box (37), a second spring (39) is fixedly connected between the two movable plates (46), and the locking seat (34) is adapted to the plug-in box (37); The front surface of the cover plate (36) is fixedly connected to a locking box (40), and the interior of the locking box (40) is slidably connected to a locking block (41), the rear end of the locking block (41) passes through the interior of the plug-in box (37), and the outer side wall is in contact with the opposite sides of the two movable sheets (46), a plurality of springs (42) are fixedly connected between the locking block (41) and the locking box (40), and the inner upper surface of the locking box (40) is rotatably connected to a hand-held rod (43) via a rotating shaft, and a traction rope (44) is fixedly connected between the hand-held rod (43) and the locking block (41), the bottom end of the hand-held rod (43) passes through the bottom of the locking box (40), and the outer side wall is fixedly connected to a rubber sleeve (45).

2. The radio frequency chip test electromagnetic shielding box according to claim 1, characterized in that: The bottom of the slider 1 (11) is located below the supporting plate (2) and is fixedly connected to a rack 1 (16); the lower surface of the supporting plate (2) is located between the two racks 1 (16) and is fixedly connected to a gear 1 (17); the gear 1 (17) is meshingly connected to the rack 1 (16); and a spring 4 (47) is fixedly connected between the slider 1 (11) and the slide groove 1 (10).

3. The radio frequency chip test electromagnetic shielding box according to claim 1, characterized in that: Anti-slip grooves (18) are symmetrically provided inside the shielding box (1), and anti-slip blocks (19) are fixedly connected to the insides of the two anti-slip grooves (18) at the rear of both sides of the bearing plate body (2).

4. The radio frequency chip test electromagnetic shielding box according to claim 1, characterized in that: Two transmission wheels (20) are rotatably connected to the lower left side of the shielding box (1) via a rotating shaft, and the outer side walls of the two transmission wheels (20) are commonly connected to a transmission belt (21). A second gear (22) is fixedly connected to the right side of the transmission wheel (20) located at the front of the shielding box (1), and a second rack (23) is fixedly connected to the left side of the lower surface of the supporting plate (2), and the second gear (22) is meshingly connected to the second rack (23).

5. The electromagnetic shielding box for radio frequency chip testing according to claim 4, characterized in that: The right side of the transmission wheel (20) at the rear of the shielding box (1) is fixedly connected to a hollow tube (24); the interior of the hollow tube (24) and the interior of the hollow spiral tube (3) are slidably connected to a rotating rod (25); the outer wall of the rotating rod (25) is located at the opposite ends of the hollow spiral tube (3) and the hollow tube (24) and is fixedly connected to two abutment plates (26); the right end of the rotating rod (25) passes through the right end of the hollow spiral tube (3) and is fixedly connected to a knob (27).

6. The electromagnetic shielding box for radio frequency chip testing according to claim 5, characterized in that: The outer wall of the rotating rod (25) is provided with a limit plate (28) between the two abutment plates (26); the lower surface of the shielding box (1) is fixedly connected with a fixing bar (29); the interior of the fixing bar (29) is slidably connected with a guide rod (30); the right end of the guide rod (30) is fixedly connected with a limit plate (31); the top of the limit plate (31) is located on the outer side of the limit plate (28) and a limit groove (32) is provided; a spring (33) is fixedly connected between the fixing bar (29) and the limit bar (31).

Images