Photosensitive resin recovery device

Abstract

The invention provides a photosensitive resin recovery device, and belongs to the technical field of 3D printing equipment, the photosensitive resin recovery device comprises a support, a recovery box is fixedly connected to the support, the interior of the recovery box is hollow, the upper end of the recovery box is communicated with the outside, a recovery pipe is fixedly connected to the upper surface of the recovery box, and a sealing cover is fixedly connected to one end of the recovery pipe; one end of the recycling pipe penetrates through the sealing cover and then extends below the liquid level of resin in the resin tank, a sealing mechanism used for improving the sealing performance between the sealing cover and the upper surface of the resin tank is arranged on the sealing cover, and an air blowing mechanism used for introducing air into the sealing cover is arranged on the upper surface of the sealing cover; the resin recovery device has the advantage that an operator can conveniently recover resin in the resin tank.

Description

Technical Field

[0001] The invention belongs to the technical field of 3D printing equipment, in particular to a photosensitive resin recovery device. Background Art

[0002] SLA is the earliest practical rapid prototyping technology, using liquid photosensitive resin as raw material. Its process is to first design a three-dimensional solid model through CAD, slice the model using discrete programs, design the scanning path, and the generated data will accurately control the movement of the laser scanner and the lifting platform; the laser beam passes through the scanner controlled by the CNC device and irradiates the surface of the liquid photosensitive resin according to the designed scanning path, so that a layer of resin in a specific area of ​​the surface is solidified. When a layer is processed, a cross section of the part is generated; then the lifting platform is lowered a certain distance, and another layer of liquid resin is covered on the solidified layer, and then the second layer is scanned. The second solidified layer is firmly bonded to the previous solidified layer, and the three-dimensional workpiece prototype is formed by stacking layers.

[0003] After the 3D product is printed using photosensitive resin, the photosensitive resin in the print cylinder is discharged from the inner wall of the print cylinder and some photosensitive resin will remain. The remaining photosensitive resin needs to be manually cleaned by the staff, which is troublesome and wastes manpower. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems in the prior art and to provide a photosensitive resin recovery device, which is convenient for the operator to recover the resin in the resin tank.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A photosensitive resin recovery device comprises a bracket, a recovery box is fixedly connected to the bracket, the interior of the recovery box is hollow and the upper end is connected to the outside, a recovery pipe is fixedly connected to the upper surface of the recovery box, a sealing cover is fixedly connected to one end of the recovery pipe, one end of the recovery pipe passes through the sealing cover and extends below the resin liquid level in the resin tank, a sealing mechanism for improving the sealing between the sealing cover and the upper surface of the resin tank is provided on the sealing cover, and an air blowing mechanism for introducing air into the sealing cover is provided on the upper surface of the sealing cover.

[0007] Furthermore, the sealing mechanism includes a sealing plate fixedly connected to the lower surface of the sealing cover, a sealing groove opened on the lower surface of the sealing plate, a sealing strip installed in the sealing groove, a sealing rubber strip fixedly connected to the lower surface of the sealing strip, and a locking member arranged on the sealing cover for locking the sealing cover to the upper surface of the resin tank.

[0008] Furthermore, the locking member includes two fixing seats fixedly connected to the upper surface of the inner wall of the sealing cover, a locking plate rotatably connected to the fixing seat, a locking plate rotatably connected to the lower end of the locking plate, a waist-shaped groove provided on the outer wall of the upper end of the locking plate, a locking screw rotatably connected to the upper surface of the inner wall of the sealing cover through a rotating seat, two locking blocks threadedly connected to the outer wall of the locking screw, a locking rod fixedly connected to the outer wall of the locking block, a retaining ring fixedly connected to the outer wall of one end of the locking rod passing through the waist-shaped groove and a servo motor fixedly connected to the upper surface of the inner wall of the sealing cover for driving the locking screw to rotate, and the locking plate is pressed against the inner wall of the resin tank under the drive of the locking plate.

[0009] Furthermore, the sealing strip is slidably connected in the sealing groove, a sealing spring is fixedly connected to the outer side wall of the sealing strip, a driving groove is provided on the inner wall of the sealing groove, a driving hole is provided on the lower surface of the sealing plate, a driving block is fixedly connected to the side wall of one side of the sealing strip, a guide surface is provided on the lower surface of the end of the driving block away from the sealing strip, the guide surface is arranged downward, a driving rod is slidably connected in the driving hole, the upper end of the driving rod abuts against the guide surface, the lower end of the driving rod protrudes out of the driving hole, a driving spring is sleeved on the outer wall of the upper end of the driving rod, the two ends of the driving spring are respectively fixedly connected to the outer wall of the driving rod and the lower surface of the inner wall of the driving groove, and the cross-section of the sealing rubber strip is arranged in a regular triangle.

[0010] Furthermore, an installation groove is provided on the side wall of the lock plate away from the resin tank, the installation groove is vertically arranged, a rotating rod is fixedly connected between the inner walls on both sides of the installation groove, a locking rod is rotatably connected to the outer wall of the rotating rod, a clamping plate is rotatably connected to one end of the locking rod, a torsion spring is sleeved on the outer wall of the rotating rod, and when the torsion spring is in the original length state, the end of the locking rod away from the rotating rod is inclined upward.

[0011] Furthermore, a mounting hole is provided on the bottom of the mounting groove, a mounting spring is fixedly connected to the bottom of the mounting hole, and the other end of the mounting spring is fixedly connected to a side wall of one side of the locking rod.

[0012] Furthermore, the inflation mechanism includes an air pump fixedly connected to the sealing cover and an air outlet pipe fixedly connected to the air outlet of the air pump, and the other end of the air outlet pipe is fixedly connected to the sealing cover and communicated with the interior of the sealing cover.

[0013] Furthermore, one end of the recovery tube located in the resin tank is flexibly arranged, an absorption tube is fixedly connected to the end face of the recovery tube located in the resin tank, a plurality of through grooves are provided on the outer wall of the end of the absorption tube away from the recovery tube, a mounting ring is fixedly connected to the inner wall of the end of the absorption tube away from the recovery tube, a fixing seat is fixedly connected to the upper surface of the mounting ring, a sliding groove is provided on the inner walls on both sides of the fixing seat, a sliding rod is slidably connected in the sliding groove, a sliding block is fixedly connected between the two sliding rods, a one-way plate is fixedly connected to the end face of one end of the sliding block, the one-way plate is circularly arranged, and the one-way plate abuts against the upper surface of the mounting ring.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. The present invention places a sealing cover on the upper surface of the resin tank, and one end of the recovery pipe extends below the resin liquid level of the resin tank. A sealing mechanism is used to form a seal between the sealing cover and the upper surface of the resin tank. The sealing cover and the resin tank form a closed cavity. Air is ventilated into the sealing cover through an air blowing mechanism. The pressure of the air in the cavity between the sealing cover and the resin tank increases. Under the action of atmospheric pressure, the resin in the resin tank is pressed into the recovery pipe, and the resin enters the recovery box through the recovery pipe. Through such an arrangement, the structure is simple and the operation is convenient, which makes it convenient for the operator to recover the resin in the resin tank.

[0016] 2. In the present invention, the sealing cover is placed on the upper surface of the resin tank, the servo motor drives the locking screw to rotate, the locking screw drives the locking block to move, the locking block drives the locking plate to rotate through the locking rod, the locking plate drives the locking plate to move, the locking plate drives the retaining plate to press against the inner wall of the resin tank, under the action of the locking rod and the friction between the retaining plate and the inner wall of the resin tank, the locking plate drives the sealing cover to move downward, the sealing cover presses against the upper surface of the resin tank, when the sealing cover presses against the upper surface of the resin tank, the driving rod moves upward, the driving rod drives the sealing strip to slide in the sealing groove through the driving block, the sealing rubber strip presses against the upper surface of the resin tank and deforms. Through such an arrangement, the structure is simple, the operation is convenient, and the sealing performance of the sealing cover and the upper surface bracket of the resin tank is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a schematic diagram of the structure on the sealing plate in the present invention.

[0019] Figure 3 It is a cross-sectional view of the sealing cover in the present invention.

[0020] Figure 4 It is a schematic diagram of the structure of the absorber tube in the present invention.

[0021] In the figure, 1, bracket; 2, recycling box; 3, recycling pipe; 4, sealing cover; 5, sealing mechanism; 6, blowing mechanism; 7, sealing plate; 8, sealing groove; 9, sealing strip; 10, sealing rubber strip; 11, locking piece; 12, fixing seat; 13, locking plate; 14, locking plate; 15, waist groove; 16, locking screw; 17, locking block; 18, locking rod; 19, retaining ring; 20, servo motor; 21, sealing spring; 22, driving groove ; 23. Drive hole; 24. Drive block; 25. Guide surface; 26. Drive rod; 27. Drive spring; 28. Mounting groove; 29. ​​Turn rod; 30. Lock rod; 31. Clamping plate; 32. Torsion spring; 33. Mounting hole; 34. Mounting spring; 35. Air pump; 36. Air outlet pipe; 37. Absorption pipe; 38. Through groove; 39. Mounting ring; 40. Support; 41. Sliding groove; 42. Sliding rod; 43. Sliding block; 44. One-way plate. DETAILED DESCRIPTION

[0022] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0023] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, a photosensitive resin recovery device includes a bracket 1, a recovery box 2 is fixedly connected to the bracket 1, the interior of the recovery box 2 is hollow and the upper end is connected to the outside, a cover plate is rotatably connected to the upper surface of the recovery box 2, a recovery pipe 3 is fixedly connected to the cover plate, one end of the recovery pipe 3 is connected to the interior of the recovery box 2, and a sealing cover 4 is fixedly connected to the other end of the recovery pipe 3, the sealing cover 4 is arranged on the upper surface of the resin tank, and one end of the recovery pipe 3 passes through the sealing cover 4 and extends into the resin liquid level in the resin tank.

[0024] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, an air blowing mechanism 6 for introducing air into the sealing cover 4 is provided on the upper surface of the sealing cover 4, and the air blowing mechanism 6 includes an air pump 35, and the air pump 35 is fixedly connected to the upper surface of the sealing cover 4, and an air outlet pipe 36 is fixedly connected to the air outlet of the air pump 35, and one end of the air outlet pipe 36 is fixedly connected to the upper surface of the sealing cover 4 and communicated with the interior of the sealing cover 4.

[0025] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, a sealing mechanism 5 for improving the sealing performance between the sealing cover 4 and the upper surface of the resin tank is provided on the lower surface of the sealing cover 4, and the sealing mechanism 5 includes a sealing plate 7, which is fixedly connected to the lower surface of the sealing cover 4. The lower end of the sealing cover 4 is rectangular, and a sealing plate 7 is fixedly connected to the four sides of the lower surface of the sealing cover 4. A sealing groove 8 is provided on the lower surface of the sealing plate 7, and a sealing strip 9 is installed in the sealing groove 8. A plurality of sealing rubber strips 10 are fixedly connected to the lower surface of the sealing strip 9. The cross-section of the sealing rubber strip 10 is an equilateral triangle, and the plurality of sealing rubber strips 10 are evenly spaced along the width direction of the sealing strip 9. A locking member 11 for locking the sealing cover 4 to the upper surface of the resin tank is provided on the sealing cover 4.

[0026] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the locking member 11 includes a fixing seat 12, the fixing seat 12 is fixedly connected to the upper surface of the inner wall of the sealing cover 4, two fixing seats 12 are fixedly connected to the upper surface of the inner wall of the sealing cover 4, a locking plate 13 is rotatably connected to the fixing seat 12, a locking plate 14 is rotatably connected to the lower end surface of the locking plate 13, the locking plate 14 is vertically arranged, the locking plate 14 is pressed against the inner wall of the resin tank under the drive of the locking plate 13, a waist-shaped groove 15 is provided on the outer wall of the upper end of the locking plate 13, and the locking plate 14 is rotated on the upper surface of the inner wall of the sealing cover 4 through the rotating seat A locking screw 16 is connected, and the threads on the outer walls at both ends of the locking screw 16 have opposite rotation directions. A locking block 17 is threadedly connected to the outer walls at both ends of the locking screw 16, and a locking rod 18 is fixedly connected to the outer wall of the locking block 17. One end of the locking rod 18 passes through the waist-shaped groove 15, and a retaining ring 19 is fixedly connected to the outer wall of the end of the locking rod 18 passing through the waist-shaped groove 15. A servo motor 20 is fixedly connected to the upper surface of the inner wall of the sealing cover 4, and the output shaft of the servo motor 20 is fixedly connected to one end of the locking screw 16 through a coupling.

[0027] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, in order to improve the stability of the lock plate 14 against the inner wall of the resin tank, a mounting groove 28 is provided on the side wall of the lock plate 14 close to the inner wall of the resin tank. The mounting groove 28 is vertically arranged. A rotating rod 29 is fixedly connected between the inner walls on both sides of the mounting groove 28. A locking rod 30 is rotatably connected to the outer wall of the rotating rod 29. A locking plate 31 is rotatably connected to one end of the locking rod 30. The rotating shaft of the locking rod 30 on the locking plate 31 is located at the upper end of the side wall of the locking plate 31. A torsion spring 32 is sleeved on the outer wall of 29, and the two ends of the torsion spring 32 are respectively fixedly connected to the outer walls of the rotating rod 29 and the locking rod 30. When the torsion spring 32 is in the original length state, the end of the locking rod 30 away from the rotating rod 29 is tilted upward, and the clamping plate 31 is vertically arranged. A mounting hole 33 is opened on the bottom of the mounting groove 28, and a mounting spring 34 is fixedly connected to the bottom of the mounting hole 33. The other end of the mounting spring 34 is fixedly connected to the outer wall of the end of the locking rod 30 away from the rotating rod 29.

[0028] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, in order to improve the sealing between the sealing cover 4 and the upper surface of the resin tank, the sealing strip 9 is slidably connected in the sealing groove 8, and a sealing spring 21 is fixedly connected to the outer side wall of the sealing strip 9, and the other end of the sealing spring 21 is pressed against the inner wall of the sealing groove 8, and a driving groove 22 is provided on the inner wall of the sealing groove 8, and a driving hole 23 is provided on the lower surface of the sealing plate 7, and the driving hole 23 is connected with the driving groove 22, and a driving block 24 is fixedly connected to the side wall of one side of the sealing strip 9, and the driving block 24 is slidably connected in the driving groove 22, and a guide surface 25 is provided on the lower surface of the end of the driving block 24 away from the sealing strip 9, and the guide surface 25 is arranged downward, and a driving rod 26 is slidably connected in the driving hole 23, and the upper end of the driving rod 26 is pressed against the guide surface 25, and a driving spring 27 is sleeved on the outer wall of the upper end of the driving rod 26, and the two ends of the driving spring 27 are respectively fixedly connected to the outer wall of the driving rod 26 and the lower surface of the inner wall of the driving groove 22.

[0029] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, an inflation mechanism 6 is provided on the upper surface of the sealing cover 4, and the inflation mechanism 6 includes an air pump 35, and the air pump 35 is fixedly connected to the upper surface of the sealing cover 4, and an air outlet pipe 36 is fixedly connected to the air outlet of the air pump 35, and one end of the air outlet pipe 36 is fixedly connected to the upper surface of the sealing cover 4 and communicated with the interior.

[0030] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, one end of the recovery tube 3 located in the resin tank is flexibly arranged, and an absorption tube 37 is coaxially fixedly connected to the end face of the recovery tube 3 located in the resin tank, and a plurality of through grooves 38 are provided on the outer wall of the end of the absorption tube 37 away from the recovery tube 3, and the through grooves 38 are connected to the inside of the absorption tube 37, and a mounting ring 39 is fixedly connected to the inner wall of the end of the absorption tube 37 away from the recovery tube 3, and the inner wall of the mounting ring 39 is circular, and a support 40 is fixedly connected to the upper surface of the mounting ring 39, and a sliding groove 41 is provided on the inner walls on both sides of the support 40, and a sliding rod 42 is slidably connected in the sliding groove 41, and a sliding block 43 is fixedly connected between the two sliding rods 42, and a one-way plate 44 is fixedly connected to the end face of one end of the sliding block 43, and the one-way plate 44 is circular, and the one-way plate 44 abuts against the upper surface of the mounting ring 39.

[0031] The working principle of the embodiment of the present invention is as follows: when the operator needs to recycle the resin in the resin tank, the sealing cover 4 is placed on the upper surface of the resin tank, and under the gravity of the sealing cover 4, the driving rod 26 moves upward, and the driving rod 26 drives the sealing strip 9 to move through the driving block 24, and the sealing strip 9 drives the sealing rubber strip 10 to move, and the sealing rubber strip 10 is deformed;

[0032] The servo motor 20 drives the locking screw 16 to rotate, the locking screw 16 drives the locking block 17 to move, the locking block 17 drives the locking plate 13 to rotate through the locking rod 18, the locking plate 13 drives the locking plate 14 to move, and the locking plate 14 drives the abutting plate 31 to abut against the inner wall of the resin tank;

[0033] Air is introduced into the sealing cover 4 through the air pump 35 and the air outlet pipe 36 . Under the action of atmospheric pressure, the resin in the resin tank is pressed into the recovery pipe 3 and enters the recovery box 2 through the recovery pipe 3 .

[0034] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0035] Although this article uses more 1, bracket; 2, recycling box; 3, recycling pipe; 4, sealing cover; 5, sealing mechanism; 6, blowing mechanism; 7, sealing plate; 8, sealing groove; 9, sealing strip; 10, sealing rubber strip; 11, locking piece; 12, fixing seat; 13, locking plate; 14, locking plate; 15, waist groove; 16, locking screw; 17, locking block; 18, locking rod; 19, retaining ring; 20, servo motor; 21, sealing spring; 22, driving groove; 23, driving The present invention is not limited to the following terms: 1, hole; 2, driving block; 2, guide surface; 2, driving rod; 2, driving spring; 2, mounting groove; 2, rotating rod; 3, locking rod; 3, pressing plate; 3, torsion spring; 3, mounting hole; 3, mounting spring; 3, air pump; 3, air outlet pipe; 3, absorption pipe; 3, through groove; 3, mounting ring; 4, support; 4, sliding groove; 4, sliding rod; 4, sliding block; 4, one-way plate, etc., but the possibility of using other terms is not excluded. The use of these terms is only for the purpose of more conveniently describing and explaining the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A photosensitive resin recovery device, characterized in that: The invention comprises a support (1), a recovery box (2) is fixedly connected to the support (1), the recovery box (2) is hollow inside and the upper end is connected to the outside, a recovery pipe (3) is fixedly connected to the upper surface of the recovery box (2), a sealing cover (4) is fixedly connected to one end of the recovery pipe (3), one end of the recovery pipe (3) passes through the sealing cover (4) and extends into the resin liquid level in the resin tank, a sealing mechanism (5) for improving the sealing performance between the sealing cover (4) and the upper surface of the resin tank is provided on the sealing cover (4), and an air blowing mechanism (6) for introducing air into the sealing cover (4) is provided on the upper surface of the sealing cover (4).

2. A photosensitive resin recycling device according to claim 1, characterized in that: The sealing mechanism (5) comprises a sealing plate (7) fixedly connected to the lower surface of the sealing cover (4), a sealing groove (8) provided on the lower surface of the sealing plate (7), a sealing strip (9) installed in the sealing groove (8), a sealing rubber strip (10) fixedly connected to the lower surface of the sealing strip (9), and a locking member (11) provided on the sealing cover (4) for locking the sealing cover (4) on the upper surface of the resin tank.

3. A photosensitive resin recovery device according to claim 2, characterized in that: The locking member (11) comprises two fixing seats (12) fixedly connected to the upper surface of the inner wall of the sealing cover (4), a locking plate (13) rotatably connected to the fixing seats (12), a locking plate (14) rotatably connected to the lower end of the locking plate (13), a waist-shaped groove (15) provided on the outer wall of the upper end of the locking plate (13), a locking screw (16) rotatably connected to the upper surface of the inner wall of the sealing cover (4) via the rotating seat, two locking blocks (17) threadedly connected to the outer wall of the locking screw (16), and a locking block (17) fixedly connected to the locking block (18). 17) a locking rod (18) on the outer wall, a retaining ring (19) fixedly connected to the outer wall of one end of the locking rod (18) passing through the waist-shaped groove (15), and a servo motor (20) fixedly connected to the upper surface of the inner wall of the sealing cover (4) for driving the locking screw (16) to rotate, the threads on the outer walls at both ends of the locking screw (16) have opposite rotation directions, and the two locking blocks (17) are respectively threadedly connected to the outer walls at both ends of the locking screw (16), and the locking plate (14) is pressed against the inner wall of the resin tank under the drive of the locking plate (13).

4. A photosensitive resin recovery device according to claim 3, characterized in that: The sealing strip (9) is slidably connected in the sealing groove (8); a sealing spring (21) is fixedly connected to the outer side wall of the sealing strip (9); a driving groove (22) is provided on the inner wall of the sealing groove (8); a driving hole (23) is provided on the lower surface of the sealing plate (7); a driving block (24) is fixedly connected to the side wall of one side of the sealing strip (9); a guide surface (25) is provided on the lower surface of one end of the driving block (24) away from the sealing strip (9); and the guide surface (25) ) is arranged downward, a driving rod (26) is slidably connected in the driving hole (23), the upper end of the driving rod (26) abuts against the guide surface (25), the lower end of the driving rod (26) exceeds the driving hole (23), a driving spring (27) is sleeved on the outer wall of the upper end of the driving rod (26), and the two ends of the driving spring (27) are respectively fixedly connected to the outer wall of the driving rod (26) and the lower surface of the inner wall of the driving groove (22), and the cross-section of the sealing rubber strip (10) is arranged in the shape of an equilateral triangle.

5. A photosensitive resin recovery device according to claim 4, characterized in that: A mounting groove (28) is provided on a side wall of the lock plate (14) close to the resin tank. The mounting groove (28) is vertically arranged. A rotating rod (29) is fixedly connected between the inner walls on both sides of the mounting groove (28). A locking rod (30) is rotatably connected to the outer wall of the rotating rod (29). A pressing plate (31) is rotatably connected to one end of the locking rod (30). A torsion spring (32) is sleeved on the outer wall of the rotating rod (29). When the torsion spring (32) is in the original length state, the end of the locking rod (30) away from the rotating rod (29) is tilted upward.

6. A photosensitive resin recovery device according to claim 5, characterized in that: A mounting hole (33) is provided on the bottom of the mounting groove (28), a mounting spring (34) is fixedly connected to the bottom of the mounting hole (33), and the other end of the mounting spring (34) is fixedly connected to a side wall of one side of the locking rod (30).

7. The photosensitive resin recycling device according to claim 1, characterized in that: The inflation mechanism (6) comprises an air pump (35) fixedly connected to the sealing cover (4) and an air outlet pipe (36) fixedly connected to the air outlet of the air pump (35); the other end of the air outlet pipe (36) is fixedly connected to the sealing cover (4) and communicates with the interior of the sealing cover (4).

8. The photosensitive resin recycling device according to claim 1, characterized in that: One end of the recovery pipe (3) located in the resin tank is flexibly arranged. An absorption pipe (37) is fixedly connected to the end surface of the recovery pipe (3) located in the resin tank. A plurality of through grooves (38) are provided on the outer wall of the end of the absorption pipe (37) away from the recovery pipe (3). A mounting ring (39) is fixedly connected to the inner wall of the end of the absorption pipe (37) away from the recovery pipe (3). A support (40) is fixedly connected to the upper surface of the mounting ring (39). A sliding groove (41) is provided on the inner walls on both sides of the support (40). A sliding rod (42) is slidably connected in the sliding groove (41). A sliding block (43) is fixedly connected between the two sliding rods (42). A one-way plate (44) is fixedly connected to the end surface of one end of the sliding block (43). The one-way plate (44) is circularly arranged and abuts against the upper surface of the mounting ring (39).

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