Automatic injection molding equipment for light guide plate

Abstract

The invention discloses automatic injection molding equipment for a light guide plate, which comprises an equipment main body, a purification tower is mounted at the top of the equipment main body, the purification tower is communicated with a mold locking part assembly in the equipment main body through a smoke exhaust pipe I, a smoke exhaust pipe II is fixedly connected in the purification tower, and the automatic injection molding equipment further comprises a spraying assembly; a driving assembly; a linkage oscillation assembly; and a cleaning assembly. The motor is started to drive the driving shaft to rotate, the spraying head is driven to rotate through gear transmission, water mist sprayed out when the spraying head rotates covers harmful waste gas entering the purification tower more widely and more uniformly, the treatment effect on the harmful gas is better, and the treatment effect is better. Meanwhile, a second water pipe at the top of the spraying head is rotationally connected with the top of the whole purification tower through a bearing, and the upper end of the second water pipe movably sleeves the outer wall of the first water pipe, so that water source conveying of the first water pipe and the second water pipe is not affected when the spraying tower rotates, and the spraying method has a better adsorption effect on harmful substances in harmful gas.

Description

Technical Field

[0001] The invention relates to the field of injection molding equipment, and in particular to automatic injection molding equipment for light guide plates. Background Art

[0002] Injection molding of light guide plates is an important process for making large optical components. Due to its excellent optical properties and good light transmittance, it is widely used in LED lighting, automotive lamps, flat-panel TVs and other fields. The main raw material of injection molding of light guide plates is PC (polycarbonate) resin, and its content is generally between 85% and 90%. In addition, auxiliary materials such as light scattering agents and light stabilizers need to be added. During the production process, various materials need to be mixed evenly in a certain proportion to ensure the quality of the finished product. The raw materials and auxiliary materials are formed through melting, injection cooling, demolding and other steps. Some waste gas may be generated during this process.

[0003] The existing Chinese patent publication number is: CN212219088U, which provides a new type of injection molding equipment, including: a machine body, a clamping mechanism, an injection mechanism, a hydraulic mechanism and an exhaust gas treatment mechanism, the clamping mechanism and the hydraulic mechanism are both arranged on the machine body, and both sides of the clamping mechanism are provided with movable opening and closing observation windows, the injection mechanism is driven and connected with the clamping mechanism and the hydraulic mechanism, the exhaust gas treatment mechanism is arranged on the top of the clamping mechanism, the exhaust gas treatment mechanism includes an exhaust gas cooling component, an exhaust gas filtering component and a box body, the box body is arranged on the top of the clamping mechanism, the exhaust gas cooling component is arranged on the box body, the exhaust gas filtering component is arranged in the box body, the bottom of the box body is provided with a first through hole, and the exhaust gas filtering component is connected with the clamping mechanism. By arranging the exhaust gas cooling component and the exhaust gas filtering component, the high-temperature exhaust gas is discharged after being cooled by the exhaust gas cooling component, and various additives and decomposition substances remain in the high-temperature exhaust gas. The exhaust gas can be released into the atmospheric environment through the adsorption and filtration of the residues by the exhaust gas filtering component, while protecting human health.

[0004] The above-mentioned injection molding machine also has the following problems during use: the harmful gases generated during the operation of the above-mentioned injection molding machine are only adsorbed by a single filter component, the overall filtering effect is slow, and the filter element of the filter component needs to be replaced frequently to ensure that the filtering effect meets the standard.

[0005] Therefore, it is necessary to invent an automatic injection molding device for light guide plates to solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide an automatic injection molding device for a light guide plate to solve the problem raised in the above-mentioned background technology that the harmful gases generated during the operation of the above-mentioned injection molding machine are only adsorbed by a single filter component, the overall filtering effect is slow, and the filter element of the filter component needs to be replaced frequently to ensure that the filtering effect meets the standard.

[0007] In order to achieve the above-mentioned object, the present invention provides the following technical solutions: an automatic injection molding device for a light guide plate, comprising a device body, a purification tower is installed on the top of the device body, and the purification tower is connected to the clamping part assembly inside the device body through a smoke exhaust pipe 1, and the interior of the purification tower is also fixedly connected to a smoke exhaust pipe 2, an inspection port is opened in the tower body of the purification tower, and a bracket is fixedly sleeved on the outer wall of the purification tower, and a filter plate is movably sleeved inside the purification tower, and also includes:

[0008] A spray assembly, wherein a water tank is embedded inside the main body of the equipment, a spray head is rotatably connected inside the purification tower, and the top of the spray head is connected to a second water pipe, and the second water pipe is movably sleeved on the outer wall of the first water pipe, and the bottom of the purification tower is connected to the top of the water tank through a third water pipe;

[0009] A driving assembly, wherein the outer wall of the purification tower is fixedly connected to a motor, and the output shaft of the motor is drivingly connected to a driving shaft, and a gear is fixedly sleeved on the outer wall of the driving shaft, and the gear is meshedly connected with a gear ring fixed on the top wall of the spray head;

[0010] A linkage oscillating assembly, wherein the bottom of the filter plate is fixedly connected with a wedge-shaped block, and the two ends of the filter plate are movably sleeved on the outer wall of the short rod;

[0011] A cleaning component, wherein the bottom wall of the spray head is fixedly connected with a connecting rod, and a brush is movably sleeved on the outer ring of the connecting rod.

[0012] Preferably, a closed door is hinged on the inner wall of the inspection opening via a hinge shaft, and the transverse middle section of the inspection opening is flush with the filter plate.

[0013] Preferably, the lower pipe opening of water pipe 2 is fixedly connected to the water inlet at the top of the sprinkler head, and the outer wall of the upper pipe opening of water pipe 2 is rotatably connected to the water inlet reserved at the top of the purification tower through a bearing, the upper pipe opening of water pipe 1 extends to the inner wall of the upper pipe opening of water pipe 2 and is rotatably connected to the upper pipe opening of water pipe 2, and the inner wall of the pipe opening of water pipe 2 and the outer wall of the pipe opening of water pipe 1 are both smooth surfaces.

[0014] Preferably, the spray head is columnar, and the annular outer wall of the spray head is fitted with and rotatably connected to the inner wall of an open annular groove reserved inside the purification tower body.

[0015] Preferably, the filter plate includes a fitting groove and a filter element in addition to its own plate body, and an annular fitting groove with an open top and a closed bottom is provided inside the filter plate body, and two symmetrical fan-shaped filter elements are completely fitted inside the fitting groove, and the outer wall of the filter element is fitted with and slidably connected to the annular inner wall of the annular fitting groove.

[0016] Preferably, a columnar channel is provided in the middle of the filter plate, wherein the diameter of the columnar channel is equal to the diameter of the outer wall of the connecting rod, and the inner wall of the columnar channel and the outer wall of the connecting rod are both smooth surfaces, and the connecting rod is rotatably connected to the inner wall of the columnar channel inside the filter plate;

[0017] A wedge-shaped block is fixedly connected to the center line of the bottom of the filter plate, and the top of the "hook-shaped" rod body at the lower end of the connecting rod is in contact with the inclined end of the wedge-shaped block.

[0018] Preferably, there are two short rods, which are symmetrically arranged with the vertical rod body of the connecting rod as the symmetry axis, and both short rods are fixedly connected to the inner wall of the purification tower close to the short rods through a connecting plate, and the height of the short rod is slightly larger than the sum of the heights of the filter plate and the wedge block.

[0019] Preferably, a cylindrical through hole that passes through from top to bottom is opened in the middle position of the brush handle at the top of the brush, and a limiting rod is fixedly connected to the inner wall of the through hole, the limiting rod divides the through hole into two areas, and the outer wall of the limiting rod and the inner wall of a part of the through hole area are in contact with the outer wall of the connecting rod and the inner wall of the groove opened inside the connecting rod, and are slidably connected up and down.

[0020] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0021] 1. Start the motor to mobilize the drive shaft to rotate, which in turn drives the gear fixed on the outer wall of the drive shaft to rotate. The gear is meshed with the toothed ring fixed on the top wall of the spray head, which drives the spray head to rotate. The rotation of the spray head makes the sprayed water mist cover the harmful exhaust gas entering the purification tower more widely and more evenly, and the treatment effect of harmful gas is better. At the same time, the water pipe 2 on the top of the spray head is rotatably connected to the top of the entire purification tower through the bearing, and the upper end of the water pipe 2 is movably sleeved on the outer wall of the water pipe 1, which ensures that the spray tower does not affect the transportation of water source by the water pipe 1 and the water pipe 2 when rotating, and the spray method has a better adsorption effect on harmful substances in harmful gases;

[0022] 2. At the same time, during the rotation of the spray tower, the connecting rod fixed at the bottom of the spray pipe is driven to rotate synchronously. During the rotation, the lower end of the connecting rod abuts against the wedge-shaped block fixed at the bottom of the filter plate, thereby pushing the filter plate to move upward. When the connecting rod rotates away from the wedge-shaped block, there is no supporting force at the bottom of the filter plate. The fall of the filter plate causes the filter plate body to collide with the connecting blocks fixed at the upper and lower ends of the short rod to generate vibration, which facilitates the rapid return of water contained in the filter element embedded in the filter plate into the water tank, making it convenient for the filtered water in the water tank to be reused again;

[0023] 3. The filter element embedded inside the filter plate is easy to remove and replace. At the same time, the brush movably sleeved on the outer wall of the connecting rod above the filter element synchronizes the rotation of the connecting rod to clean the impurities on the surface of the filter element to prevent the impurities on the surface of the filter element from clogging the filter element and affecting the drainage. At the same time, the brush is movably connected to the connecting rod up and down. When the filter plate moves up and down, under the action of the brush's own gravity, the bristles of the brush can always stick to the surface of the filter element to keep it clean.

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a three-dimensional diagram of the overall structure of the present invention;

[0026] Figure 2 It is a first-view stereoscopic diagram of the purification tower (partially cut away) of the present invention;

[0027] Figure 3 It is a second perspective stereogram of the purification tower (partially cut away) of the present invention;

[0028] Figure 4 It is an exploded view of the overall structure of the filter plate of the present invention;

[0029] Figure 5 It is a three-dimensional diagram of the internal structure of the filter plate (partially cut away) of the present invention;

[0030] Figure 6 It is a stereoscopic diagram of the overall structure of the driving assembly of the present invention;

[0031] Figure 7 It is an exploded view of the connecting rod and the brush of the present invention.

[0032] Description of reference numerals:

[0033] 1. Equipment body; 2. Exhaust pipe 1; 3. Purification tower; 4. Exhaust pipe 2; 5. Inspection port; 51. Closed door; 6. Bracket; 7. Spray assembly; 71. Water pipe 1; 72. Water pipe 2; 73. Water pipe 3; 74. Spray head; 75. Annular groove; 76. Water tank; 8. Drive assembly; 81. Motor; 82. Drive shaft; 83. Gear; 84. Gear ring; 9. Filter plate; 91. Fitting groove; 92. Filter element; 10. Linkage oscillation assembly; 101. Short rod; 102. Wedge block; 11. Cleaning assembly; 111. Brush; 112. Limit rod; 113. Channel; 114. Through hole; 12. Connecting rod. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] The present invention provides Figure 1-7 The light guide plate automatic injection molding device shown in the figure includes an equipment body 1, a purification tower 3 is installed on the top of the equipment body 1, and the purification tower 3 is connected to the clamping part assembly inside the equipment body 1 through a smoke exhaust pipe 2, and the interior of the purification tower 3 is also fixedly connected to a smoke exhaust pipe 2 4, an inspection port 5 is opened in the tower body of the purification tower 3, and a bracket 6 is fixedly sleeved on the outer wall of the purification tower 3, and a filter plate 9 is movably sleeved inside the purification tower 3, and also includes:

[0036] Spray assembly 7, a water tank 76 is embedded inside the equipment body 1, a spray head 74 is rotatably connected in the purification tower 3, and the top of the spray head 74 is connected to a water pipe 2 72, and the water pipe 2 72 is movably sleeved on the outer wall of the water pipe 1 71, and the bottom of the purification tower 3 is connected to the top of the water tank 76 through the water pipe 3 73, which is convenient for the supply of water;

[0037] The drive assembly 8, the outer wall of the purification tower 3 is fixedly connected with a motor 81, and the output shaft of the motor 81 is drivingly connected with a drive shaft 82, and the outer wall of the drive shaft 82 is fixedly sleeved with a gear 83, and the gear 83 is meshed with a toothed ring 84 fixed on the top wall of the spray head 74. The motor 81 drives the drive shaft 82 to rotate, driving the gear 83 fixedly sleeved on the outer wall of the drive shaft 82 to rotate, thereby driving the rotation of the spray head 74 meshed with the gear 83 and fixedly connected to the bottom of the toothed ring 84;

[0038] The linkage oscillation component 10 has a wedge-shaped block 102 fixedly connected to the bottom of the filter plate 9, and both ends of the filter plate 9 are movably sleeved on the outer wall of the short rod 101;

[0039] The cleaning component 11 and the bottom wall of the spray head 74 are fixedly connected with a connecting rod 12, and a brush 111 is movably sleeved on the outer ring of the connecting rod 12. The brush 111 is driven to rotate by the rotation of the connecting rod 12. The rotation of the brush 111 cleans some granular impurities on the surface of the filter element 92 to prevent the impurities on the surface of the filter element 92 from clogging the filter element 92 and affecting the drainage.

[0040] A closed door 51 is hinged on the inner wall of the inspection opening 5 via a hinge shaft, and the transverse middle section of the inspection opening 5 is flush with the position of the filter plate 9, so that the closed door 51 can be opened conveniently to replace the filter element 92.

[0041] The lower pipe mouth of water pipe 2 72 is fixedly connected to the water inlet at the top of the spray head 74, and the outer wall of the upper pipe mouth of water pipe 2 72 is rotatably connected to the water inlet reserved at the top of the purification tower 3 through a bearing, the upper pipe mouth of water pipe 1 71 extends to the inner wall of the upper pipe mouth of water pipe 2 72 and is rotatably connected to the upper pipe mouth of water pipe 2 72, and the inner wall of the pipe mouth of water pipe 2 72 and the outer wall of the pipe mouth of water pipe 1 71 are both smooth surfaces, so that the water supply of water pipe 1 71 to water pipe 2 72 will not be affected during the rotation of the spray head 74.

[0042] The spray head 74 is columnar, and the annular outer wall of the spray head 74 is in contact with and rotatably connected to the inner wall of an open annular groove 75 reserved in the body of the purification tower 3 , thereby ensuring the stability of the rotation of the spray head 74 .

[0043] In addition to the filter plate body itself, the filter plate 9 also includes an embedding groove 91 and a filter element 92. The filter plate 9 is provided with an annular embedding groove 91 with an open top and a closed bottom inside the plate body, and two symmetrical fan-shaped filter elements 92 are fully embedded inside the embedding groove 91. The outer wall of the filter element 92 is in contact with the annular inner wall of the annular embedding groove 91 and is slidably connected, so that the filter element 92 is easy to replace.

[0044] A columnar channel is provided in the middle of the filter plate 9, wherein the diameter of the columnar channel is equal to the diameter of the outer wall of the connecting rod 12, and the inner wall of the columnar channel and the outer wall of the connecting rod 12 are both smooth surfaces, and the connecting rod 12 is rotatably connected to the inner wall of the columnar channel inside the filter plate 9, and the filter plate 9 will not be driven to rotate during the rotation of the connecting rod 12;

[0045] A wedge block 102 is fixedly connected to the center line of the bottom of the filter plate 9, and the top of the "hook-shaped" rod body at the lower end of the connecting rod 12 contacts the inclined end of the wedge block 102, which facilitates the rotation of the connecting rod 12. The lower end of the connecting rod 12 abuts against the wedge block 102, thereby lifting the filter plate 9 as a whole.

[0046] There are two short rods 101, which are symmetrically arranged with the vertical rod body of the connecting rod 12 as the symmetry axis, and the two short rods 101 are fixedly connected to the inner wall of the purification tower 3 close to the short rods 101 through connecting plates. The height of the short rod 101 is slightly larger than the sum of the heights of the filter plate 9 and the wedge block 102, thereby ensuring the stability of the up and down movement of the filter plate 9.

[0047] A cylindrical through hole 114 is provided in the middle position of the brush handle at the top of the brush 111, and the inner wall of the through hole 114 is fixedly connected to a limiting rod 112. The limiting rod 112 divides the through hole 114 into two areas, and the outer wall of the limiting rod 112 and the inner wall of a part of the through hole 114 are in contact with the outer wall of the connecting rod 12 and the inner wall of the groove 113 provided inside the connecting rod 12, and are connected by sliding up and down, ensuring that the brush 111 can rotate with the rotation of the connecting rod 12, and can also move up and down with the lifting and lowering of the filter plate 9 during the rotation, without affecting the cleaning of the filter element 92 by the brush 111.

[0048] Working principle: When using a light guide plate automatic injection molding device, first start the motor 81, and the drive shaft 82 connected to the output shaft of the motor 81 rotates, thereby driving the gear 83 fixedly sleeved on the outer wall of the drive shaft 82 to rotate, and the gear 83 is meshed with the gear ring 84 fixedly connected to the top wall of the spray head 74, thereby driving the spray head 74 to rotate. The spray head 74 rotates in the annular groove 75 preset inside the purification tower 3, ensuring the stability of the rotation of the spray head 74. At the same time, the spray sprayed by the spray head 74 has a larger overall coverage area and more uniform coverage as the spray head 74 rotates;

[0049] During the rotation of the spray head 74, the connecting rod 12 fixedly connected to the bottom of the spray head 74 rotates synchronously, and the lower end of the connecting rod 12 will contact the wedge block 102 fixedly connected to the bottom of the filter plate 9 during the rotation. As the connecting rod 12 rotates, when the lower end of the connecting rod 12 contacts the inclined portion of the wedge block 102, it will support the wedge block 102 and the filter plate 9 fixedly connected to the top of the wedge block 102 to move upward. When the connecting rod 12 rotates and no longer contacts the wedge block 102, the wedge block 102 and the bottom of the filter plate 9 have no supporting force and fall down accordingly. The falling of the filter plate 9 causes the plate body of the filter plate 9 to collide with the connecting body blocks fixed at the upper and lower ends of the short rod 101 to generate vibrations, which facilitates the water contained in the filter element 92 embedded in the filter plate 9 to quickly flow back into the water tank 76, so that the water filtered by the filter assembly in the water tank 76 can be reused for the second time.

[0050] At the same time, when the filter element 92 needs to be replaced, the closed door 51 is opened, and the two symmetrical filter elements 92 that are embedded in the embedding groove 91 are conveniently installed at the mouth of the filter element 92, and then the new filter element 92 is installed;

[0051] During the rotation of the spray head 74, the connecting rod 12 fixedly connected to the bottom of the spray head 74 rotates synchronously, thereby driving the rotation of the brush 111 movably sleeved on the outer wall of the connecting rod 12. The rotation of the brush 111 allows the bristles of the brush 111 to clean some granular impurities on the surface of the filter element 92, thereby preventing the impurities on the surface of the filter element 92 from clogging the filter element 92 and affecting the drainage. At the same time, the brush 111 can rotate with the rotation of the connecting rod 12, and the brush 111 can also move up and down with the rise and fall of the filter plate 9 during the rotation, which does not affect the cleaning of the filter element 92 by the brush 111.

[0052] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An automatic injection molding device for a light guide plate, comprising a device body (1), a purification tower (3) is installed on the top of the device body (1), and the purification tower (3) is connected to the clamping part component inside the device body (1) through a smoke exhaust pipe (2), and the interior of the purification tower (3) is also fixedly connected to a smoke exhaust pipe (4), an inspection port (5) is opened in the tower body of the purification tower (3), and a bracket (6) is fixedly sleeved on the outer wall of the purification tower (3), and a filter plate (9) is movably sleeved inside the purification tower (3), characterized in that: Also includes: A spray assembly (7), wherein a water tank (76) is embedded inside the equipment body (1), a spray head (74) is rotatably connected inside the purification tower (3), and the top of the spray head (74) is connected to a second water pipe (72), and the second water pipe (72) is movably sleeved on the outer wall of the first water pipe (71), and the bottom of the purification tower (3) is connected to the top of the water tank (76) through a third water pipe (73); A drive assembly (8), wherein the outer wall of the purification tower (3) is fixedly connected to a motor (81), and the output shaft of the motor (81) is drivingly connected to a drive shaft (82), and the outer wall of the drive shaft (82) is fixedly sleeved with a gear (83), and the gear (83) is meshingly connected to a gear ring (84) fixed to the top wall of the spray head (74); A linked oscillation component (10), wherein the bottom of the filter plate (9) is fixedly connected with a wedge block (102), and both ends of the filter plate (9) are movably sleeved on the outer wall of the short rod (101); A cleaning component (11), wherein the bottom wall of the spray head (74) is fixedly connected to a connecting rod (12), and a brush (111) is movably sleeved on the outer ring of the connecting rod (12).

2. The automatic injection molding equipment for light guide plates according to claim 1, characterized in that: A closed door (51) is hingedly connected to the inner wall of the inspection opening (5) via a hinge shaft, and the transverse middle section of the inspection opening (5) is flush with the filter plate (9).

3. The automatic injection molding equipment for light guide plates according to claim 1, characterized in that: The lower pipe opening of the water pipe 2 (72) is fixedly connected to the water inlet at the top of the spray head (74), and the outer wall of the upper pipe opening of the water pipe 2 (72) is rotatably connected to the water inlet reserved at the top of the purification tower (3) through a bearing, the upper pipe opening of the water pipe 1 (71) extends to the inner wall of the upper pipe opening of the water pipe 2 (72) and is rotatably connected to the upper pipe opening of the water pipe 2 (72), and the inner wall of the pipe opening of the water pipe 2 (72) and the outer wall of the pipe opening of the water pipe 1 (71) are both smooth surfaces.

4. The automatic injection molding equipment for light guide plates according to claim 3, characterized in that: The spray head (74) is columnar, and the annular outer wall of the spray head (74) is in contact with and rotatably connected to the inner wall of an open annular groove (75) reserved in the body of the purification tower (3).

5. The automatic injection molding equipment for light guide plates according to claim 1, characterized in that: The filter plate (9) includes a fitting groove (91) and a filter element (92) in addition to its plate body. The filter plate (9) is provided with an annular fitting groove (91) with an open top and a closed bottom inside the plate body. Two symmetrical fan-shaped filter elements (92) are completely fitted inside the fitting groove (91). The outer wall of the filter element (92) is fitted with the annular inner wall of the annular fitting groove (91) and is slidably connected.

6. The automatic injection molding equipment for light guide plates according to claim 5, characterized in that: A columnar channel extending vertically through the filter plate (9) is provided in the middle of the filter plate (9), wherein the diameter of the columnar channel is equal to the diameter of the outer wall of the connecting rod (12), and the inner wall of the columnar channel and the outer wall of the connecting rod (12) are both smooth surfaces, and the connecting rod (12) is rotatably connected to the inner wall of the columnar channel inside the filter plate (9); A wedge-shaped block (102) is fixedly connected to the centerline position of the bottom of the filter plate (9), and the top of the "hook-shaped" rod body at the lower end of the connecting rod (12) contacts the inclined end of the wedge-shaped block (102).

7. The automatic injection molding equipment for light guide plates according to claim 1, characterized in that: The short rods (101) are provided in two numbers, and the two short rods (101) are symmetrically arranged with the vertical rod body of the connecting rod (12) as the symmetry axis, and the two short rods (101) are fixedly connected to the inner wall of the purification tower (3) close to the short rods (101) through a connecting plate, and the height of the short rods (101) is slightly greater than the sum of the heights of the filter plate (9) and the wedge block (102).

8. The automatic injection molding equipment for light guide plates according to claim 1, characterized in that: A columnar through hole (114) is provided in the middle of the brush handle at the top of the brush (111), and the inner wall of the through hole (114) is fixedly connected to a limiting rod (112), the limiting rod (112) divides the through hole (114) into two areas, and the outer wall of the limiting rod (112) and the inner wall of a part of the through hole (114) are in contact with the outer wall of the connecting rod (12) and the inner wall of a groove (113) provided inside the connecting rod (12), and are connected by sliding up and down.

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