A PVB film cooling and shaping equipment

Abstract

The invention discloses a PVB film cooling and shaping device, and relates to the technical field of film processing. The heating roller in the invention is heated by high-temperature liquid, and can heat the PVB film quickly and evenly, ensuring that the film has reached an appropriate temperature before entering the stretching roller. Since a plurality of discharge ports are arranged in the heating roller, the high-temperature liquid can be discharged from the heating roller more evenly, which can effectively improve the heating efficiency, ensure that the film is heated evenly, and improve the product quality; the diameters of a plurality of driving pulleys are reduced in sequence, and the driving of the linkage driving belt is combined to gradually increase the rotation speed of each stretching roller, so as to realize multi-stage stretching of the PVB film, ensure the stability and uniformity of the stretching process, and gradually reach the set thickness requirements, improve the stretching effect, and make the PVB film have excellent physical properties.

Description

Technical Field

[0001] The invention relates to the technical field of film processing, in particular to a PVB film cooling and shaping device. Background Art

[0002] At present, the production method of PVB film has some obvious shortcomings. The traditional heating method is usually heated by electric heating wire or electric heating plate, which has low thermal efficiency and uneven heating, which can easily cause local overheating or overcooling of the film, affecting product quality. During the stretching process, a single-speed stretching roller is usually used, and multi-level control cannot be achieved, resulting in an unstable stretching process and inability to ensure the uniformity and consistency of the film. The traditional cooling method mainly relies on natural cooling or a simple water cooling system, which has low cooling efficiency and cannot effectively control the temperature of the coolant, resulting in uneven cooling of the film and affecting the cooling and shaping effect. In addition, the existing cooling system generally lacks temperature control and cannot flexibly adjust the cooling parameters according to actual needs, resulting in a lack of flexibility and efficiency in the entire production process. Summary of the invention

[0003] In order to overcome the defects of the above-mentioned prior art, the present invention provides the following technical solutions: a PVB film cooling and shaping equipment, comprising two bases, the two bases are fixedly mounted on a bottom plate, two symmetrically arranged supporting side plates are fixedly mounted on the bases, a plurality of cross-arranged stretching rollers are rotatably mounted between the two supporting side plates, one of the stretching rollers is arranged in a cooling pool fixed to the supporting side plates, and a coolant is arranged in the cooling pool; a heating roller is also rotatably mounted between the two supporting side plates, and the heating roller is used to heat the PVB film; a reinforcing side plate is fixedly fitted on the side of one of the supporting side plates, and the same number of drive pulleys as all the stretching rollers are rotatably mounted on the reinforcing side plate, all the drive pulleys are coaxially fixedly matched with the corresponding stretching rollers, and a drive pulley coaxially fixedly matched with the heating roller is also rotatably mounted on the reinforcing side plate, the diameters of all the drive pulleys decrease successively from the first drive pulley fixed to the heating roller to the last drive pulley fixed to the stretching roller, and all the drive pulleys are matched through linkage drive belt transmission.

[0004] Preferably, two openings are provided on both sides of the bottom of the cooling pool, and the two openings are connected by a curved main circulation pipe, and a secondary circulation pipe is also provided in parallel on the main circulation pipe, wherein a heat absorption chamber is provided in series in the secondary circulation pipe; a first valve and a second valve are provided in series on the secondary circulation pipe and the main circulation pipe, and a water pump is also provided in series at the position of the main circulation pipe and the opening at the bottom of the cooling pool to drive the circulation of the coolant.

[0005] Preferably, an evaporation pool is provided on the main circulation pipeline, the interior of the evaporation pool is hollow, and a window is provided on one side of the upper surface of the evaporation pool, and a cooling fin is fixedly sealed at the window. Electronic fluoride liquid is provided inside the evaporation pool, and the liquid level can completely cover the main circulation pipeline. The interior of the cooling fin is hollow, and the hollow part of the cooling fin is communicated with the interior of the evaporation pool.

[0006] Preferably, refrigeration fins are provided between the opposing surfaces of the heat absorption chamber and the evaporation pool through contact with thermally conductive silicone grease, an exhaust nozzle is provided between the heat absorption chamber and the cooling pool, one of the openings of the exhaust nozzle is aligned with the cooling fins for blowing air toward the cooling fins, the other opening of the exhaust nozzle is fixedly connected to an air intake duct, a gas turbine is coaxially rotatably installed in the air intake duct, and the air intake duct is fixed on the base.

[0007] Preferably, a flow isolation tube is coaxially fixedly sealed inside the heating roller, a heating inlet and a second row of ports are provided at both ends of the flow isolation tube, a first row of ports is provided in the middle of the flow isolation tube, wherein a heating tube is coaxially arranged inside the flow isolation tube, the heating tube is located between one end of the heating inlet and the flow isolation tube and is fixedly sealed with a separating sealing ring, a rotating interface is installed as a rotary seal at one end of the flow isolation tube, the rotary seal of the rotating interface is sleeved on the outer surface of the heating tube, high-temperature liquid enters the flow isolation tube through the heating tube, and then enters the space between the flow isolation tube and the heating roller through the heating inlet, and is discharged to the position of the rotating interface through the first row of ports and the second row of ports, the rotating interface discharges the high-temperature liquid for secondary heating, and the heated liquid circulates into the heating tube again.

[0008] Preferably, a first transmission support plate and a second transmission support plate are also fixedly mounted on the base plate, wherein two mutually meshing control gears and a planetary gear plate are rotatably mounted on the first transmission support plate, a center gear is provided at a coaxial position on the side of the planetary gear plate, the center gear and the gas turbine are fixedly transmitted through a transmission shaft, and three planetary gears meshing with the center gear are also rotatably mounted on the side of the planetary gear plate.

[0009] Preferably, a gear ring mounting disk is rotatably mounted on the second transmission support plate, a gear ring is fixedly mounted on the gear ring mounting disk, and the gear ring is meshed with the three planetary gears.

[0010] Preferably, a regulating motor and a driving motor are fixedly mounted on the second transmission support plate, wherein the output shaft of the regulating motor is fixed to the regulating gear, and a driving pulley is fixedly mounted on the output shaft of the driving motor, and the driving pulley is connected to the gear ring mounting plate through a driving transmission belt.

[0011] Preferably, a driving pulley is fixedly mounted on the output shaft of the driving motor, and the driving pulley drives all the driving pulleys to rotate via a linkage transmission belt.

[0012] Compared with the prior art, the present invention has the following beneficial effects: (1) The heating roller in the present invention is heated by high-temperature liquid, which can heat the PVB film quickly and evenly, ensuring that the film has reached an appropriate temperature before entering the stretching roller. Since multiple discharge ports are provided in the heating roller, the high-temperature liquid can be discharged from the heating roller more evenly, which can effectively improve the heating efficiency, ensure that the film is heated evenly, and improve the product quality; (2) The present invention reduces the diameter of multiple drive pulleys in sequence, and combines the drive of the linkage drive belt to gradually increase the rotation speed of each stretching roller, thereby realizing multi-stage stretching of the PVB film. The stability and uniformity of the stretching process are ensured, and the set thickness requirements can be gradually achieved, the stretching effect is improved, and the PVB film has excellent physical properties; (3) The coolant circulation system in the cooling pool of the present invention is combined with the design of the refrigeration plate, so that the coolant is always kept at an appropriate low temperature state, effectively cooling and shaping the stretched PVB film. By adjusting the first valve and the second valve, the temperature of the coolant can be flexibly controlled to ensure the stability of the cooling process of the PVB film, avoid quality problems caused by temperature fluctuations, and improve the effect and efficiency of cooling and shaping. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 It is a schematic diagram of the cooling fin structure of the present invention.

[0015] Figure 3 It is a schematic diagram of the structure of the driving belt of the present invention.

[0016] Figure 4 It is a structural schematic diagram of the planetary gear disc of the present invention.

[0017] Figure 5 It is a schematic diagram of the cooling pool structure of the present invention.

[0018] Figure 6 It is a structural schematic diagram of the linkage transmission belt of the present invention.

[0019] Figure 7 This is a position distribution diagram of the stretching roller and the heating roller of the present invention.

[0020] Figure 8 It is a schematic diagram of the internal structure of the heating roller of the present invention.

[0021] In the figure: 101-base; 102-bottom plate; 103-transmission shaft; 104-support side plate; 105-central gear; 106-stretching roller; 107-heating roller; 108-heating pipe; 109-rotating interface; 110-first row port; 111-heating inlet; 112-second row port; 113-separation sealing ring; 114-flow isolation pipe; 115-cooling pool; 116-reinforced side plate; 117-transmission pulley; 118-driving pulley; 119-linked transmission belt; 120-main circulation pipeline; 121-first valve; 12 2-second valve; 123-heat absorption chamber; 124-refrigeration plate; 125-water pump; 126-secondary circulation pipeline; 127-air intake pipeline; 128-gas turbine; 129-exhaust nozzle; 130-evaporation pool; 131-cooling fins; 132-first transmission support plate; 133-second transmission support plate; 134-regulating motor; 135-driving motor; 136-driving pulley; 137-driving transmission belt; 138-gear ring mounting plate; 139-regulating gear; 140-gear ring; 141-planetary gear plate; 142-planetary gear. DETAILED DESCRIPTION

[0022] Combine the following Figure 1-Figure 8 , and further illustrate the technical solution of the present invention through specific implementation methods.

[0023] The present invention provides a PVB film cooling and shaping device, comprising two bases 101, the two bases 101 are fixedly mounted on a bottom plate 102, two symmetrically arranged supporting side plates 104 are fixedly mounted on the base 101, a plurality of cross-arranged stretching rollers 106 are rotatably mounted between the two supporting side plates 104, one of the stretching rollers 106 is arranged in a cooling pool 115 fixed to the supporting side plates 104, and a cooling liquid is arranged in the cooling pool 115; a heating roller 107 is also rotatably mounted between the two supporting side plates 104, and the heating roller 107 is used to heat the PVB film; one of the supporting side plates 104 A reinforcing side plate 116 is fixedly provided on the side, and the same number of transmission pulleys 117 as all the stretching rollers 106 are rotatably mounted on the reinforcing side plate 116. All the transmission pulleys 117 are coaxially fixed with the corresponding stretching rollers 106. There is also a rotatable transmission pulley 117 coaxially fixed with the heating roller 107 on the reinforcing side plate 116. The diameters of all the transmission pulleys 117 decrease successively from the first transmission pulley 117 fixed with the heating roller 107 to the last transmission pulley 117 fixed with the stretching roller 106, and all the transmission pulleys 117 are coupled together by an interlocking transmission belt 119. Two openings are arranged on both sides of the bottom of the cooling pool 115, and the two openings are connected through a curved main circulation pipe 120. A secondary circulation pipe 126 is also connected in parallel to the main circulation pipe 120, wherein a heat absorption chamber 123 is arranged in series in the secondary circulation pipe 126; a first valve 121 and a second valve 122 are arranged in series on the secondary circulation pipe 126 and the main circulation pipe 120, wherein a water pump 125 is also connected in series between the main circulation pipe 120 and the bottom opening of the cooling pool 115, for driving the circulation of the coolant. An evaporation pool 130 is sleeved on the main circulation pipe 120, and the interior of the evaporation pool 130 is hollow, and a window is opened on one side of the upper surface of the evaporation pool 130, and a cooling fin 131 is fixedly sealed at the window, and an electronic fluoride liquid is arranged inside the evaporation pool 130, and the liquid level height can completely cover the main circulation pipe 120, and the interior of the cooling fin 131 is hollow, and the hollow part of the cooling fin 131 is connected to the interior of the evaporation pool 130. The cooling fins 124 are provided between the opposite surfaces of the heat absorption chamber 123 and the evaporation pool 130 through thermal grease contact. An exhaust nozzle 129 is provided between the heat absorption chamber 123 and the cooling pool 115. One of the openings of the exhaust nozzle 129 is aligned with the cooling fins 131 for blowing air toward the cooling fins 131. The other opening of the exhaust nozzle 129 is fixedly connected to an air intake duct 127. A gas turbine 128 is coaxially rotatably installed in the air intake duct 127. The air intake duct 127 is fixed on the base 101.A flow separator 114 is coaxially and fixedly sealed in the heating roller 107. A heating inlet 111 and a second row of ports 112 are provided at both ends of the flow separator 114. A first row of ports 110 is provided in the middle of the flow separator 114. A heating tube 108 is coaxially arranged in the flow separator 114. The heating tube 108 is located between one end of the heating inlet 111 and the flow separator 114 and is fixedly sealed and matched by a separating sealing ring 113. A rotating interface 109 is installed on one end of the flow separator 114 for rotational sealing. The rotating interface 109 is rotationally sealed on the outer surface of the heating tube 108. High-temperature liquid enters the flow separator 114 through the heating tube 108, and then enters the space between the flow separator 114 and the heating roller 107 through the heating inlet 111, and is discharged to the position of the rotating interface 109 through the first row of ports 110 and the second row of ports 112. The rotating interface 109 discharges the high-temperature liquid for secondary heating, and the heated liquid circulates into the heating tube 108 again. The bottom plate 102 is also fixedly mounted with a first transmission support plate 132 and a second transmission support plate 133, wherein two mutually meshing regulating gears 139 and a planetary gear plate 141 are rotatably mounted on the first transmission support plate 132, a central gear 105 is provided at a coaxial position on the side of the planetary gear plate 141, the central gear 105 is fixedly driven with the gas turbine 128 through the transmission shaft 103, and three planetary gears 142 meshing with the central gear 105 are rotatably mounted on the side of the planetary gear plate 141. A gear ring mounting plate 138 is rotatably mounted on the second transmission support plate 133, a gear ring 140 is fixedly mounted on the gear ring mounting plate 138, and the gear ring 140 meshes with the three planetary gears 142. A regulating motor 134 and a driving motor 135 are fixedly mounted on the second transmission support plate 133, wherein the output shaft of the regulating motor 134 is fixed to the regulating gear 139, a driving pulley 136 is fixedly mounted on the output shaft of the driving motor 135, and the driving pulley 136 is connected to the gear ring mounting plate 138 via a driving transmission belt 137. A driving pulley 118 is also fixedly mounted on the output shaft of the driving motor 135, and the driving pulley 118 drives all the driving pulleys 117 to rotate via a linkage transmission belt 119.

[0024] The working principle of a PVB film cooling and shaping device disclosed in the present invention is as follows: the PVB film is passed through the heating roller 107 in sequence, cross-passed through all the stretching rollers 106, and then drawn out from a stretching roller 106 above the cooling pool 115, and one end of the PVB film is fixed on the traction reel for collection. The heating roller 107 is heated by a high-temperature liquid (such as silicone oil), and then the PVB film is preheated so that the edge of the PVB film is plastically stretched in sequence by a plurality of cross-arranged stretching rollers 106 to reach a set thickness. Since the diameters of the plurality of transmission pulleys 117 are reduced in sequence, here it means that along the moving direction of the PVB film, the diameters of the corresponding transmission pulleys 117 are reduced in sequence. Since the transmission pulleys 117 drive the corresponding stretching rollers 106 to rotate, each stretching roller 10 6 are all the same diameter, and all the drive pulleys 117 are connected together through the linkage drive belt 119, so their rotational linear speeds are the same, which results in different rotational speeds of all the drive pulleys 117, and thus the rotational speeds of all the stretching rollers 106 along the moving direction of the PVB film increase in sequence, achieving the purpose of gradually stretching the PVB film (since the rotational speed of the previous stretching roller 106 is greater than that of the latter, the PVB film between the two stretching rollers 106 can be pulled). The linkage drive belt 119 is driven by the driving pulley 118, and the driving pulley 118 is driven to rotate by the output shaft of the driving motor 135.

[0025] The output shaft of the driving motor 135 will also drive the active pulley 136 to rotate. The active pulley 136 drives the gear ring mounting plate 138 to rotate through the driving transmission belt 137. The gear ring mounting plate 138 drives the gear ring 140 to rotate. The gear ring 140 drives the central gear 105 to rotate through the planetary gear 142. The central gear 105 drives the gas turbine 128 to rotate through the transmission shaft 103. The gas turbine 128 draws external air into the intake duct 127 and then discharges it through the exhaust nozzle 129. The air discharged from the exhaust nozzle 129 passes through the cooling fins 131 to cool the cooling fins 131. In order to increase the air flow passing through the cooling fins 131, a gap is left between the cooling fins 131 and the exhaust nozzle 129. The air between the exhaust nozzle 129 and the cooling fins 131 is in a flowing state. Therefore, the pressure of the air between the cooling fins 131 and the exhaust nozzle 129 is reduced. At this time, the surrounding air will be sucked in, thereby increasing the air flow and improving the cooling effect on the cooling fins 131. The rotation speed of the center gear 105 determines the rotation speed of the gas turbine 128, that is, the air intake. The rotation of the center gear 105 needs to ensure that the planetary gear 141 is in a fixed state or a force-limited state. Therefore, it is necessary to limit the rotation of the planetary gear 141 by adjusting the rotation of the gear 139, so that the planetary gear 141 is in a force state. The force state of the planetary gear 141 determines the rotation speed of the center gear 105. Therefore, by controlling the rotation direction and speed of the output shaft of the control motor 134, the rotation speed of the center gear 105 can be controlled, thereby realizing the adjustment of the air intake of the gas turbine 128, and then adjusting the heat dissipation effect of the cooling fins 131.

[0026] After being heated and stretched, the PVB film needs to be cooled and shaped. In the final stage of stretching the PVB film, it is immersed in the cooling pool 115. The coolant in the cooling pool 115 will cool and shape the PVB film. In order to ensure that the coolant in the cooling pool 115 is always in a low temperature state and to ensure the cooling and shaping effect of the PVB film, the coolant needs to be cooled. At this time, the water pump 125 is started, and the water pump 125 discharges the coolant in the cooling pool 115 into the heat absorption chamber 123, and then circulates it into the cooling pool 115 (at this time, the first valve 121 is in an open state, and the second valve 122 is in a closed state), and the refrigeration plate 124 is started, and the cooling surface of the refrigeration plate 124 absorbs the heat in the heat absorption chamber 123, so that the heat absorption chamber 12 3, the temperature of the coolant inside the cooling pool 115 is reduced, and the heating surface of the cooling fin 124 will introduce heat into the evaporation pool 130, heating the electronic fluoride liquid inside the evaporation pool 130, and the electronic fluoride liquid evaporates under the heat, and the evaporated gas will float into the cooling fin 131. Since the temperature of the cooling fin 131 is lower than the boiling point of the electronic fluoride liquid, the gaseous electronic fluoride liquid will condense at this time, and then fall back into the evaporation pool 130 under the action of gravity. The cooling fin 131 absorbs the gaseous electronic fluoride liquid, which will cause its own temperature to rise. Therefore, the gas ejected from the exhaust nozzle 129 will reduce the temperature of the cooling fin 131, thereby ensuring that the temperature of the cooling fin 131 is lower than the boiling point of the electronic fluoride liquid. At the same time, the inside of the evaporation pool 130 and the cooling fin 131 can also be set to a negative pressure environment to improve the heat dissipation effect. If the temperature of the coolant in the cooling pool 115 is too low, the first valve 121 needs to be closed and the second valve 122 needs to be opened (the opening and closing amounts of the first valve 121 and the second valve 122 are selected as needed). Since the main circulation pipeline 120 is also arranged in the evaporation pool 130, the heat of the evaporation pool 130 will be partially transferred to the main circulation pipeline 120, thereby heating the coolant in the main circulation pipeline 120. At this time, the heated coolant will enter the cooling pool 115, thereby increasing the temperature of the coolant in the cooling pool 115. The temperature inside the cooling pool 115 can be controlled by the opening and closing amounts of the first valve 121 and the second valve 122, ensuring that the temperature of the coolant in the cooling pool 115 is in the required state, thereby ensuring the cooling and shaping quality of the PVB film.

Claims

1. A PVB film cooling and shaping device, characterized in that: The invention comprises two bases (101), wherein the two bases (101) are fixedly mounted on a bottom plate (102), two symmetrically arranged supporting side plates (104) are fixedly mounted on the bases (101), a plurality of cross-arranged stretching rollers (106) are rotatably mounted between the two supporting side plates (104), one of the stretching rollers (106) is arranged in a cooling pool (115) fixed to the supporting side plate (104), and a cooling liquid is arranged in the cooling pool (115); A heating roller (107) is rotatably mounted between the two supporting side plates (104), and the heating roller (107) is used to heat the PVB film; Two openings are provided on both sides of the bottom of the cooling pool (115), and the two openings are connected via a bent main circulation pipe (120). A secondary circulation pipe (126) is also provided in parallel with the main circulation pipe (120), wherein a heat absorption chamber (123) is provided in series in the secondary circulation pipe (126); a first valve (121) and a second valve (122) are provided in series on the secondary circulation pipe (126) and the main circulation pipe (120), wherein a water pump (125) is also provided in series between the main circulation pipe (120) and the bottom opening of the cooling pool (115) for driving the heat absorption chamber (123) to flow in the secondary circulation pipe (126). The cooling liquid circulates; wherein an evaporation pool (130) is provided on the main circulation pipeline (120); the interior of the evaporation pool (130) is hollow; a window is provided on one side of the upper surface of the evaporation pool (130); a cooling fin (131) is fixedly sealed at the window; an electronic fluoride liquid is provided inside the evaporation pool (130); the liquid level of the electronic fluoride liquid is high enough to completely cover the main circulation pipeline (120); the interior of the cooling fin (131) is hollow; and the hollow part of the cooling fin (131) is communicated with the interior of the evaporation pool (130); the opposite surfaces of the heat absorption chamber (123) and the evaporation pool (130) are A refrigeration fin (124) is provided between the heat absorption chamber (123) and the cooling pool (115) via thermally conductive silicone grease; an exhaust nozzle (129) is provided between the heat absorption chamber (123) and the cooling pool (115); one opening of the exhaust nozzle (129) is aligned with the cooling fin (131) and is used to blow air toward the cooling fin (131); another opening of the exhaust nozzle (129) is fixedly connected to an air intake pipe (127); a gas turbine (128) is coaxially rotatably installed in the air intake pipe (127); the air intake pipe (127) is fixed on the base (101); a flow barrier tube (114) is coaxially fixedly sealed in the heating roller (107) A heating inlet (111) and a second row of ports (112) are provided at both ends of the flow isolation tube (114), a first row of ports (110) is provided in the middle of the flow isolation tube (114), a heating tube (108) is provided at a coaxial position in the flow isolation tube (114), the heating tube (108) is located between one end of the heating inlet (111) and is fixedly sealed with the flow isolation tube (114) through a separating sealing ring (113), one end of the flow isolation tube (114) is rotatably sealed with a swivel interface (109), and the swivel interface (109) is swivel-sealed on the outer surface of the heating tube (108); A reinforcing side plate (116) is fixedly attached to the side of one of the supporting side plates (104), and the reinforcing side plate (116) is rotatably mounted with the same number of drive pulleys (117) as all the stretching rollers (106), and all the drive pulleys (117) are coaxially fixedly matched with the corresponding stretching rollers (106). The reinforcing side plate (116) also has a drive pulley (117) rotatably fixedly matched with the heating roller (107), and the diameters of all the drive pulleys (117) decrease in sequence from the first drive pulley (117) fixed with the heating roller (107) to the last drive pulley (117) fixed with the stretching roller (106), and all the drive pulleys (117) are connected to each other through a linkage drive belt (119).

2. A PVB film cooling and shaping device according to claim 1, characterized in that: A first transmission support plate (132) and a second transmission support plate (133) are also fixedly mounted on the bottom plate (102), wherein two mutually meshing regulating gears (139) and a planetary gear plate (141) are rotatably mounted on the first transmission support plate (132), a central gear (105) is coaxially disposed on the side of the planetary gear plate (141), the central gear (105) and the gas turbine (128) are fixedly driven via a transmission shaft (103), and three planetary gears (142) meshing with the central gear (105) are also rotatably mounted on the side of the planetary gear plate (141).

3. A PVB film cooling and shaping device according to claim 2, characterized in that: A gear ring mounting plate (138) is rotatably mounted on the second transmission support plate (133), a gear ring (140) is fixedly mounted on the gear ring mounting plate (138), and the gear ring (140) is meshed with three planetary gears (142).

4. A PVB film cooling and shaping device according to claim 3, characterized in that: A regulating motor (134) and a driving motor (135) are fixedly mounted on the second transmission support plate (133), wherein the output shaft of the regulating motor (134) is fixed to the regulating gear (139), and a driving pulley (136) is fixedly mounted on the output shaft of the driving motor (135), and the driving pulley (136) is connected to the gear ring mounting plate (138) via a driving transmission belt (137).

5. The PVB film cooling and shaping equipment according to claim 4, characterized in that: A driving pulley (118) is also fixedly mounted on the output shaft of the driving motor (135), and the driving pulley (118) drives all the driving pulleys (117) to rotate via a linkage transmission belt (119).

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