Chain clamp overload protection device and two-way stretching equipment

Abstract

The utility model discloses a chain clamp overload protection device and two-way stretching equipment, the chain clamp overload protection device comprises a driving motor, a transmission shaft and a driving chain wheel, the transmission shaft is sleeved on the periphery of a driving shaft of the driving motor, and the driving chain wheel is sleeved on the periphery of the transmission shaft. The overload protection device comprises a driving chain wheel, a transmission shaft, a shaft sleeve, a safety pin, a first overload protection piece, a second overload protection piece and a mechanical switch, the shaft sleeve is fixedly installed at the top end of the driving chain wheel and arranged on the periphery of the transmission shaft in a sleeving mode, and the shaft sleeve is fixedly connected with the transmission shaft in the circumferential direction through the safety pin; a plurality of first protruding parts are formed on the outer circumferential face of the first overload protection piece at intervals, the second overload protection piece is located above the shaft sleeve and annularly arranged on the periphery of the transmission shaft, and a plurality of second protruding parts corresponding to the first protruding parts are formed on the inner circumferential face of the second overload protection piece. According to the utility model, the double-zipper clamp and the track can be prevented from being damaged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of film stretching, in particular to a chain clip overload protection device and bidirectional stretching equipment. Background Art

[0002] In the wet-process diaphragm synchronous stretching process, a biaxial stretching device is required to synchronously stretch the film in the transverse and longitudinal directions. The current mainstream double-stretching method is mechanical, that is, the change of the track is used to guide the change of the shape of the double zipper clamp, thereby achieving the transverse and longitudinal stretching of the film. Biaxial stretching equipment generally includes a track, a double zipper clamp and a sprocket device. There are two sprocket devices, both of which are arranged on the inner side of the track and correspond to the two semicircular tracks of the track respectively. The sprocket device generally includes a drive motor, a transmission shaft and a drive sprocket. The drive sprocket cooperates with the double zipper clamp, the transmission shaft sleeve is arranged on the outer periphery of the drive shaft of the drive motor, and the drive sprocket sleeve is arranged on the outer periphery of the drive shaft. During normal operation, the drive motor drives the transmission shaft to rotate through its drive shaft, the rotation of the transmission shaft can drive the drive sprocket to rotate, and the rotation of the drive sprocket can drive the double zipper clamp to move along the track, and the change of the track guides the change of the shape of the double zipper clamp, thereby achieving the transverse and longitudinal stretching of the film.

[0003] As the double zipper clamp moves along the track, its linear speed becomes faster and faster. During this period, the double zipper clamp also has to withstand the lateral tension of the film and turn at the semicircular track of the track. When the double zipper clamp is stuck, for example, the torque of the drive motor will increase. After the torque is transmitted to the drive sprocket through the transmission shaft, the double zipper clamp is easily separated from the track under the drive sprocket with large torque, which can easily cause damage to the track and the double zipper clamp, increasing the maintenance cost. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the utility model provides a chain clip overload protection device and a bidirectional stretching device, which can avoid damage to the double zipper clips and the track and reduce the maintenance cost.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] The first aspect of the utility model provides a chain clamp overload protection device, including a driving motor, a transmission shaft and a driving sprocket, the transmission shaft sleeve is arranged on the outer periphery of the driving shaft of the driving motor, the driving sprocket is arranged on the outer periphery of the transmission shaft, and also includes a sleeve, a safety pin, a first overload protection plate, a second overload protection plate and a mechanical switch, the sleeve is fixedly mounted on the top end of the driving sprocket and sleeved on the outer periphery of the transmission shaft, the sleeve is circumferentially fixedly connected to the transmission shaft through the safety pin, the first overload protection plate is fixedly arranged on the top end of the transmission shaft, a plurality of first convex portions are formed at intervals on the outer peripheral surface of the first overload protection plate, the second overload protection plate is located above the sleeve and is arranged around the outer periphery of the transmission shaft, a plurality of second convex portions corresponding to the plurality of first convex portions are formed on the inner peripheral surface of the second overload protection plate, respectively, the second convex portions are located below the corresponding first convex portions and abut against the corresponding first convex portions, and adjacent An avoidance groove is formed between the two second protrusions, and the avoidance groove is used to avoid the adjacent first protrusions. An avoidance groove is formed between the two adjacent second protrusions. The second overload protection sheet and the top end of the sleeve are connected by multiple elastic parts, and the elastic parts are in a compressed state. The mechanical switch is arranged above the second overload protection sheet, and the second overload protection sheet is used to touch the mechanical switch. The driving motor is used to drive the transmission shaft to rotate through its driving shaft, so as to drive the first overload protection sheet to rotate synchronously and the sleeve to rotate synchronously through the safety pin. The rotation of the sleeve can drive the driving sprocket, multiple elastic parts, and the second overload protection sheet to rotate synchronously. When the safety pin breaks, the transmission shaft is separated from the sleeve, and the rotation of the transmission shaft only drives the first overload protection sheet to rotate synchronously without driving the sleeve to rotate, and thus will not drive the driving sprocket, multiple elastic parts, and the second overload protection sheet to rotate synchronously.

[0007] As a preferred technical solution, the transmission shaft includes a first part and a second part formed at the top of the first part, the first part is a hollow structure, the second part is a solid structure, the first part is sleeved on the outer periphery of the drive shaft, the drive sprocket and the bushing are both sleeved on the outer periphery of the second part, the bushing is circumferentially fixedly connected to the second part through the safety pin, the first overload protection plate is fixedly arranged at the top of the second part, and the second overload protection plate is ring-arranged on the outer periphery of the second part.

[0008] As a preferred technical solution, a rotating bearing is provided between the driving sprocket, the shaft sleeve and the second part, and the rotating bearing sleeve is arranged on the outer periphery of the second part.

[0009] As a preferred technical solution, the sleeve has a first pin hole radially extending through the sleeve, the second part has a second pin hole radially extending through the second part, the second pin hole corresponds to the first pin hole, and the safety pin is inserted into the first pin hole and the second pin hole.

[0010] As a preferred technical solution, a screw hole is provided at the top of the sleeve, the screw hole is connected to the first pin hole, a positioning fastener is installed in the inner thread of the screw hole, and the end of the positioning fastener is abutted against the safety pin to fix the safety pin in the first pin hole and the second pin hole.

[0011] As a preferred technical solution, the top of the sleeve is provided with a plurality of guide rods corresponding to the plurality of elastic members, the elastic members are sleeved on the outer periphery of the corresponding guide rods, the second overload protection sheet has a plurality of through holes corresponding to the plurality of guide rods, and one end of the guide rod away from the sleeve passes through the corresponding through hole and is located above the second overload protection sheet.

[0012] As a preferred technical solution, a limit block is sleeved on the outer periphery of one end of the guide rod away from the shaft sleeve, and the outer diameter of the limit block is larger than the inner diameter of the through hole.

[0013] As a preferred technical solution, an annular mounting portion is formed on the outer circumferential surface of the bottom end of the sleeve, and the mounting portion is provided with a plurality of arc-shaped waist-shaped holes, and the plurality of waist-shaped holes are distributed in a ring-shaped manner around the sleeve. The top end of the driving sprocket has a recess, and the bottom of the recess is provided with a plurality of circular holes corresponding to the plurality of waist-shaped holes, and sleeve fasteners are installed in the circular holes and the corresponding waist-shaped holes.

[0014] As a preferred technical solution, the mechanical switch is detachably mounted on one end of the L-shaped bracket via an L-shaped support.

[0015] The second aspect of the utility model provides a bidirectional stretching device, comprising the chain clip overload protection device described in the above technical solution.

[0016] The beneficial effect of the utility model is that the utility model provides the shaft sleeve, the safety pin, the first overload protection sheet, the second overload protection sheet and the mechanical switch. When the double zipper clip is stuck, for example, the torque of the driving motor increases, thereby increasing the torque of the driving shaft. After the torque of the driving shaft is transmitted to the safety pin through the transmission shaft, the safety pin breaks due to the excessive torque, thereby separating the transmission shaft from the shaft sleeve. At this time, the transmission shaft idles and drives the first overload protection sheet to rotate. The rotation of the first overload protection sheet drives the first convex parts to rotate synchronously. When the first convex part rotates to above the adjacent avoidance groove, the first convex part is separated from the corresponding second convex part. Since the second convex part is not subjected to the squeezing force of the first convex part, under the action of the reset elastic force of the multiple elastic parts, the multiple elastic parts can drive the second overload protection sheet to move upward and touch the mechanical switch. The mechanical switch sends a signal to the control system. After receiving the signal sent by the mechanical switch, the control system controls the driving motor to stop working, thereby realizing the automatic shutdown function of the bidirectional stretching device. In this way, damage to the double zipper clip and the track can be avoided, and the maintenance cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a structural schematic diagram of a chain clip overload protection device provided by an embodiment of the utility model;

[0019] Figure 2 yes Figure 1 A schematic diagram of the structure of the chain clip overload protection device as seen from above;

[0020] Figure 3 yes Figure 1 A schematic cross-sectional view of a chain clip overload protection device is shown;

[0021] Figure 4 yes Figure 1 A cross-sectional schematic diagram of the chain clip overload protection device without the support frame, support seat and track;

[0022] Figure 5 yes Figure 1 The schematic diagram of the chain clip overload protection device shown is shown after removing the drive sprocket, the shaft sleeve, and the second overload protection sheet;

[0023] Figure 6 yes Figure 1 The schematic diagram of the structure of the chain clip overload protection device shown is shown after removing the support frame, support seat and drive motor;

[0024] Figure 7 yes Figure 6 A local enlarged schematic diagram of point A shown;

[0025] Figure 8 yes Figure 1 A schematic structural diagram of a transmission shaft and a first overload protection sheet of the chain clip overload protection device shown;

[0026] Fig. 9 yes Figure 1 A schematic structural diagram of a shaft sleeve, a first overload protection sheet, and a second overload protection sheet of a chain clip overload protection device;

[0027] Fig.10 yes Figure 1 Schematic diagram of the structure of the safety pin of the chain clip overload protection device shown. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the concept, specific structure and technical effects of the utility model in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the utility model. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the formation of a better connection structure by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the creation of the utility model can be combined interchangeably without conflicting with each other.

[0029] Please refer to Figures 1 to 8 A chain clamp overload protection device provided in one embodiment of the utility model is mainly used in bidirectional stretching equipment. The chain clamp overload protection device includes a drive motor 30, a transmission shaft 40, a drive sprocket 50, a shaft sleeve 60, a safety pin 70, a first overload protection plate 80, a second overload protection plate 90 and a mechanical switch 100.

[0030] The driving motor 30 is used to be arranged at the bottom end of the support seat 202 of the biaxial stretching device. The driving shaft 31 of the driving motor 30 is used to be arranged to penetrate the through hole 2021 of the support seat 202. The driving motor 30 is used to be electrically connected to the control system of the biaxial stretching device.

[0031] The transmission shaft 40 is used to pass through the through hole 2021 of the support seat 202 and is sleeved on the outer periphery of the driving shaft 31. The driving sprocket 50 and the bushing 60 are both sleeved on the outer periphery of the transmission shaft 40. The bushing 60 is fixedly installed at the center of the top of the driving sprocket 50. The bushing 60 is circumferentially fixedly connected to the transmission shaft 40 through the safety pin 70. In actual application, the driving motor 30, the transmission shaft 40, the driving sprocket 50, and the bushing 60 are all located on the inner side of the track 203, and the driving sprocket 50 is used to cooperate with the double zipper clamp, and the driving sprocket 50 is used to drive the double zipper clamp to move along the track 203. The driving motor 30 is used to drive the transmission shaft 40 to rotate through its driving shaft 31, so that the bushing 60 can be driven to rotate synchronously through the safety pin 70, and the rotation of the bushing 60 can drive the driving sprocket 50 to rotate synchronously. Fig.10 As shown, the safety pin 70 of this embodiment preferably adopts an existing metal cylindrical pin with a groove 71 in the middle. The groove 71 of the safety pin 70 is located between the sleeve 60 and the transmission shaft 40. Figure 3 shown.

[0032] Combination Fig. 9 As shown, the first overload protection sheet 80 is circular, and the first overload protection sheet 80 is fixed to the top end of the transmission shaft 40 by fasteners such as bolts. The rotation of the transmission shaft 40 can drive the first overload protection sheet 80 to rotate synchronously. A plurality of first protrusions 81 are formed at intervals on the outer circumference of the first overload protection sheet 80. The second overload protection sheet 90 is an annular structure, and the second overload protection sheet 90 is located above the shaft sleeve 60 and is arranged around the outer circumference of the transmission shaft 40. A plurality of second protrusions 91 corresponding to the plurality of first protrusions 81 are formed on the inner circumference of the second overload protection sheet 90, and the second protrusions 91 are located below the corresponding first protrusions 81 and abut against the corresponding first protrusions 81, and an avoidance groove 911 is formed between two adjacent second protrusions 91 (see Fig. 9 ), the width and depth of the avoidance groove 911 are greater than the width and length of the first protrusion 81, and the avoidance groove 911 is used to avoid the adjacent first protrusion 81. In this embodiment, the end of the second protrusion 91 (the end is the end of the second protrusion 91 away from the second overload protection sheet 90) is against the end of the corresponding first protrusion 81 (the end is the end of the first protrusion 81 away from the first overload protection sheet 80). There are three first protrusions 81, and the three first protrusions 81 are distributed at intervals on the outer peripheral surface of the first overload protection sheet 80. The number of second protrusions 91 corresponds to the number of first protrusions 81, which is also three. The three second protrusions 91 are distributed at intervals on the inner peripheral surface of the second overload protection sheet 90. It can be understood that the number of first protrusions 81 and second protrusions 91 can be set according to actual conditions. A plurality of elastic members 110 (see Figure 3), the elastic member 110 is, for example, a spring, and a plurality of elastic members 110 are distributed in an annular manner around the transmission shaft 40. The elastic member 110 is in a compressed state.

[0033] Combination Fig. 9 As shown, the top of the sleeve 60 is provided with a plurality of guide rods 1111 corresponding to the plurality of elastic members 110, and the elastic members 110 are sleeved on the outer periphery of the corresponding guide rods 1111. The second overload protection sheet 90 has a plurality of through holes corresponding to the plurality of guide rods 1111, and one end of the guide rod 1111 away from the sleeve 60 passes through the corresponding through holes and is located above the second overload protection sheet 90. The number of elastic members 110, guide rods 1111, and through holes can be set according to actual conditions. The rotation of the sleeve 60 can drive the plurality of elastic members 110, the second overload protection sheet 90, and the plurality of guide rods 1111 to rotate synchronously. The guide rods 1111 play a guiding role in the up and down movement of the second overload protection sheet 90.

[0034] A stopper 1112 is sleeved on the outer periphery of one end of the guide rod 1111 away from the shaft sleeve 60, and the outer diameter of the stopper 1112 is larger than the inner diameter of the through hole. The stopper 1112 limits the upward movement of the second overload protection sheet 90. It can be understood that the guide rod 1111 can also be replaced by a screw rod, and the stopper 1112 can also be replaced by a nut.

[0035] When the safety pin 70 breaks from its cutting groove 71, the transmission shaft 40 is separated from the sleeve 60, and the rotation of the transmission shaft 40 only drives the first overload protection plate 80 to rotate synchronously. The rotation of the transmission shaft 40 will not drive the sleeve 60 to rotate, and will not drive the driving sprocket 50, multiple elastic members 110, multiple guide rods 1111, and the second overload protection plate 90 to rotate synchronously.

[0036] The mechanical switch 100 is disposed above the second overload protection sheet 90, and the second overload protection sheet 90 is used to touch the mechanical switch 100. In the initial state, the mechanical switch 100 does not contact the second overload protection sheet 90. The mechanical switch 100 is used to be electrically connected to the control system. In this embodiment, the mechanical switch 100 is detachably mounted on one end of the L-shaped bracket 101 through the L-shaped bracket 102, and the other end of the L-shaped bracket 101 is used to be set on the top of the support seat 202.

[0037] The L-shaped bracket 101 includes a bracket vertical portion 1011 and a bracket horizontal portion 1012. One end of the bracket vertical portion 1011 is used to be arranged at the top of the support seat 202, the bracket horizontal portion 1012 is located above the driving sprocket 50 and the second overload protection sheet 90, and one end of the bracket horizontal portion 1012 is connected to the other end of the bracket vertical portion 1011. A first mounting hole is provided at the top of the other end of the bracket horizontal portion 1012. The first mounting hole is a threaded hole, and the L-shaped support 102 is provided with a second mounting hole corresponding to the first mounting hole. The second mounting hole is a bar hole. Fasteners such as screws are installed in the first mounting hole and the second mounting hole. The number of the first mounting hole and the second mounting hole can be set according to actual conditions. One end of the L-shaped support 102 extends in a direction close to the bracket vertical portion 1011, and the other end of the L-shaped support 102 is located above the second overload protection sheet 90. The mechanical switch 100 is provided at the other end of the L-shaped support 102. The mechanical switch 100 can be assembled and disassembled by disassembling the fasteners installed in the first mounting hole and the second mounting hole.

[0038] Through the above structure, when the utility model is actually applied, in normal operation, the control system controls the start-up of the drive motor 30, and the drive motor 30 drives the transmission shaft 40 to rotate, for example, in a counterclockwise direction through its drive shaft 31, thereby driving the first overload protection sheet 80 to rotate synchronously and the shaft sleeve 60 to rotate synchronously through the safety pin 70, thereby driving the drive sprocket 50, multiple elastic members 110, multiple guide rods 1111, and the second overload protection sheet 90 to rotate synchronously. The rotation of the drive sprocket 50 can drive the double zipper clip matched therewith to move along the track 203. During the movement of the double zipper clamp, when the double zipper clamp is stuck, for example, the torque of the drive motor 30 increases, thereby increasing the torque of the drive shaft 31. After the torque of the drive shaft 31 is transmitted to the safety pin 70 via the transmission shaft 40, the safety pin 70 breaks from its groove 71 due to the excessive torque, thereby separating the transmission shaft 40 from the sleeve 60. At this time, the rotation of the transmission shaft 40 will not drive the sleeve 60, the drive sprocket 50, the multiple elastic members 110, the multiple guide rods 1111, and the second overload protection sheet 90 to rotate synchronously, but only drives the first overload protection sheet 80 to rotate synchronously, that is, the transmission shaft 40 idles, and the rotation of the first overload protection sheet 80 will drive the multiple first protrusions 81 to rotate synchronously. When the first convex part 81 is rotated to the upper side of the adjacent avoidance groove 911, the first convex part 81 is separated from the corresponding second convex part 91. When the first convex part 81 is separated from the second convex part 91, the second convex part 91 is not subjected to the squeezing force of the first convex part 81. Thus, under the action of the restoring elastic force of the plurality of elastic members 110, the plurality of elastic members 110 can drive the second overload protection sheet 90 to move upward relative to the plurality of guide rods 1111 and touch the mechanical switch 100. The mechanical switch 100 sends a signal to the control system. After receiving the signal sent by the mechanical switch 100, the control system controls the driving motor 30 to stop working, thereby realizing the automatic shutdown function of the bidirectional stretching device, thereby avoiding damage to the double zipper clip and the track 203 and reducing the maintenance cost. Since the avoidance groove 911 plays a role of avoiding the adjacent first convex part 81, the first convex part 81 will not block the second overload protection sheet 90 during the upward movement of the second overload protection sheet 90. When the second overload protection sheet 90 touches the mechanical switch 100 , the second overload protection sheet 90 abuts against the limit block 1112 of the plurality of guide rods 1111 at one end away from the shaft sleeve 60 , and the first protrusion 81 is located below the adjacent avoidance groove 911 .

[0039] In this embodiment, the first protrusion 81 and the second protrusion 91 are staggered up and down, that is, only a part of the end of the second protrusion 91 is against the end of the first protrusion 81. In this way, when the transmission shaft 40 only drives the first overload protection plate 80 to rotate, the first protrusion 81 can be quickly rotated to the top of the adjacent avoidance groove 911, so that the first protrusion 81 can be quickly separated from the corresponding second protrusion 91, so that the equipment can be quickly shut down.

[0040] In this embodiment, combined with Figure 8 As shown, the transmission shaft 40 includes a first portion 42 and a second portion 43 formed at the top of the first portion 42. The first portion 42 is a hollow structure, and the second portion is a solid structure. The first portion 42 is used to be provided with a through hole 2021 that penetrates the support seat 202 and is sleeved on the outer periphery of the drive shaft 31. The drive sprocket 50 and the shaft sleeve 60 are both sleeved on the outer periphery of the second portion 43. The shaft sleeve 60 is circumferentially fixedly connected to the second portion 43 through a safety pin 70, and the groove 71 of the safety pin 70 is located between the shaft sleeve 60 and the second portion 43. The first overload protection sheet 80 is fixedly provided at the top of the second portion 43, and the second overload protection sheet 90 is arranged around the outer periphery of the second portion 43.

[0041] The outer circumference of the first portion 42 of the transmission shaft 40 is provided with a bearing seat 130, and the bearing seat 130 is used to be arranged on the top of the support seat 202. A support bearing 140 (see Figure 3 ), the support bearing 140 is sleeved on the outer periphery of the first part 42, and the support bearing 140 provides support for the rotation of the transmission shaft 40. A cover plate 1311 is provided at the top of the bearing seat 130, and the cover plate 1311 is arranged around the outer periphery of the first part 42. The cover plate 1311 plays a protective role for the support bearing 140.

[0042] A rotating bearing 120 is provided between the driving sprocket 50, the sleeve 60 and the second part 43, and the rotating bearing 120 is sleeved on the outer periphery of the second part 43. In normal operation, the rotating bearing 120 can rotate synchronously with the transmission shaft 40 and the driving sprocket 50, and when the transmission shaft 40 is idling, the rotating bearing 120 can provide support for the rotation of the transmission shaft 40.

[0043] The sleeve 60 is circumferentially fixedly connected to the second portion 43 by a safety pin 70. Figure 8 and Fig. 9 As shown, specifically: the sleeve 60 has a first pin hole 63 that penetrates the sleeve 60 in the radial direction, the second portion 43 has a second pin hole 41 that penetrates the second portion 43 in the radial direction, the second pin hole 41 corresponds to the first pin hole 63, and the safety pin 70 is inserted into the first pin hole 63 and the second pin hole 41. The two parts of the safety pin 70 located on both sides of the slot 71 are respectively located in the first pin hole 63 and the second pin hole 41, as shown in FIG. Figure 3 shown.

[0044] A screw hole 64 is provided at the top end of the sleeve 60, and the screw hole 64 is connected to the first pin hole 63. A positioning fastener 62, such as a screw, is installed in the inner thread of the screw hole 64. The end of the positioning fastener 62 abuts against the safety pin 70 to fix the safety pin 70 in the first pin hole 63 and the second pin hole 41 to prevent the safety pin 70 from moving out of the first pin hole 63 and the second pin hole 41.

[0045] In this embodiment, the sleeve 60 is fixedly mounted at the center of the top of the driving sprocket 50. Fig. 9 As shown, the outer peripheral surface of the bottom end of the sleeve 60 is formed with an annular mounting portion 61, and the mounting portion 61 is provided with a plurality of waist-shaped holes 611 in the shape of circular arcs, and the number of waist-shaped holes 611 can be set according to actual conditions. The plurality of waist-shaped holes 611 are distributed in an annular manner around the sleeve 60, and a recess 51 is provided at the center of the top end of the driving sprocket 50, and the bottom of the recess 51 is provided with a plurality of circular holes corresponding to the plurality of waist-shaped holes 611, respectively, and the circular holes are threaded holes, and sleeve fasteners are installed in the circular holes and the corresponding waist-shaped holes 611. The sleeve fastener includes a screw and a nut 612, and the screw is installed in the corresponding circular hole and waist-shaped hole 611, and the nut 612 is threadedly matched with the head of the screw and abuts against the top end of the mounting portion 61.

[0046] After the biaxial stretching equipment is automatically shut down, the safety pin 70 needs to be replaced. The specific steps are as follows: after the safety pin 70 is broken, the transmission shaft 40 only drives the first overload protection plate 80 to rotate. At this time, the first pin hole 63 of the sleeve 60 is not corresponding to the second pin hole 41 of the transmission shaft 40. First, remove the mechanical switch 100 from the L-shaped bracket 101, then loosen the nut 612 of the sleeve fastener and remove the screw of the sleeve fastener from the corresponding waist-shaped hole 611 and the round hole, and then remove the sleeve 60 and the mounting portion 61 of the sleeve 60 from the second part 43 of the transmission shaft 40. Then remove the positioning fastener 62 from the screw hole 64, so that it is easy to remove the part of the safety pin 70 located in the first pin hole 63. Then remove the part of the safety pin 70 located in the first pin hole 63 and the part located in the second pin hole 41 respectively. Then, the sleeve 60 is re-sleeved on the outer periphery of the second part 43, and the sleeve 60 and the mounting portion 61 are rotated so that the first pin hole 63 of the sleeve 60 corresponds to the second pin hole 41 of the transmission shaft 40, and the second overload protection sheet 90 is pressed downward so that the end of the second protrusion 91 abuts against the end of the first protrusion 81, and then the screw of the sleeve fastener is re-installed in the corresponding waist-shaped hole 611 and the round hole, and the nut 612 of the sleeve fastener is re-installed on the head of the corresponding screw and abuts against the top of the mounting portion 61 of the sleeve 60. Then, a new safety pin 70 is inserted into the first pin hole 63 and the second pin hole 41. Then, the positioning fastener 62 is re-installed in the screw hole 64, and the end of the positioning fastener 62 abuts against the safety pin 70. Then, the mechanical switch 100 is re-installed on the L-shaped bracket 101. In this way, the replacement of the safety pin 70 is completed. By providing a plurality of arc-shaped waist-shaped holes 611 on the mounting portion 61, it is convenient to adjust the relative position between the bushing 60 and the transmission shaft 40 so that the first pin hole 63 corresponds to the second pin hole 41, thereby ensuring that the safety pin 70 can be smoothly inserted into the first pin hole 63 and the second pin hole 41. Compared with the prior art, the replacement of the safety pin 70 is relatively simple, which can save installation time and difficulty.

[0047] The utility model also provides a bidirectional stretching device, including a support frame 201, a support seat 202, a track 203, a double zipper clip and the above-mentioned chain clip overload protection device. The support seat 202 is arranged at the top of the support frame 201, and the track 203 is arranged at the top of the support seat 202. There are two chain clip overload protection devices, and the two chain clip overload protection devices are both located on the inner side of the track 203 and correspond to the two semicircular tracks of the track 203 respectively. The driving motors 30 of the two chain clip overload protection devices are respectively arranged at the top of the support seat 202 and located in the support frame 201. The support seat 202 has two through holes 2021 corresponding to the driving motors 30 of the two chain clip overload protection devices, and the driving shaft 31 and the transmission shaft 40 of the driving motor 30 are both arranged through the corresponding through holes 2021. The bearing seat 130 of the chain clip overload protection device is arranged at the top of the support seat 202. By adopting the above-mentioned chain clip overload protection device, an automatic shutdown function can be realized, thereby avoiding damage to the double zipper clip and the track 203 and reducing maintenance costs.

[0048] The above is a specific description of the preferred implementation of the utility model, but the invention of the utility model is not limited to the described embodiments. Technical personnel familiar with the field can also make various equivalent deformations or substitutions without violating the spirit of the utility model. These equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A chain clip overload protection device, comprising a drive motor, a transmission shaft and a drive sprocket, wherein the transmission shaft is sleeved on the outer periphery of the drive shaft of the drive motor, and the drive sprocket is sleeved on the outer periphery of the transmission shaft, characterized in that: It also includes a shaft sleeve, a safety pin, a first overload protection sheet, a second overload protection sheet and a mechanical switch, wherein the shaft sleeve is fixedly mounted on the top end of the driving sprocket and sleeved on the outer circumference of the transmission shaft, the shaft sleeve is circumferentially fixedly connected to the transmission shaft through the safety pin, the first overload protection sheet is fixedly arranged on the top end of the transmission shaft, a plurality of first convex portions are formed at intervals on the outer circumferential surface of the first overload protection sheet, the second overload protection sheet is located above the shaft sleeve and is arranged around the outer circumference of the transmission shaft, a plurality of second convex portions corresponding to the plurality of first convex portions are formed on the inner circumferential surface of the second overload protection sheet, the second convex portions are located below the corresponding first convex portions and abut against the corresponding first convex portions, an avoidance groove is formed between two adjacent second convex portions, and the avoidance groove is used to avoid the adjacent first convex portions. The second overload protection sheet and the top end of the sleeve are connected by a plurality of elastic members, the elastic members are in a compressed state, the mechanical switch is arranged above the second overload protection sheet, the second overload protection sheet is used to touch the mechanical switch, the driving motor is used to drive the transmission shaft to rotate through its driving shaft, thereby driving the first overload protection sheet to rotate synchronously and driving the sleeve to rotate synchronously through the safety pin, the rotation of the sleeve can drive the driving sprocket, the plurality of elastic members, and the second overload protection sheet to rotate synchronously, when the safety pin breaks, the transmission shaft is separated from the sleeve, the rotation of the transmission shaft only drives the first overload protection sheet to rotate synchronously but does not drive the sleeve to rotate, and further does not drive the driving sprocket, the plurality of elastic members, and the second overload protection sheet to rotate synchronously.

2. The chain clip overload protection device according to claim 1, characterized in that: The transmission shaft includes a first part and a second part formed at the top of the first part, the first part is a hollow structure, the second part is a solid structure, the first part is sleeved on the outer circumference of the drive shaft, the drive sprocket and the bushing are both sleeved on the outer circumference of the second part, the bushing is circumferentially fixedly connected to the second part through the safety pin, the first overload protection plate is fixedly set on the top of the second part, and the second overload protection plate is ring-arranged on the outer circumference of the second part.

3. The chain clip overload protection device according to claim 2, characterized in that: A rotating bearing is arranged between the driving sprocket, the shaft sleeve and the second part, and the rotating bearing sleeve is arranged on the outer periphery of the second part.

4. The chain clip overload protection device according to claim 2, characterized in that: The sleeve has a first pin hole that penetrates the sleeve radially, the second part has a second pin hole that penetrates the second part radially, the second pin hole corresponds to the first pin hole, and the safety pin is inserted into the first pin hole and the second pin hole.

5. The chain clip overload protection device according to claim 4, characterized in that: A screw hole is provided at the top end of the sleeve, the screw hole is connected to the first pin hole, a positioning fastener is installed in the inner thread of the screw hole, and the end of the positioning fastener abuts against the safety pin to fix the safety pin in the first pin hole and the second pin hole.

6. The chain clip overload protection device according to claim 1, characterized in that: A plurality of guide rods corresponding to the plurality of elastic members are respectively provided at the top end of the sleeve, and the elastic members are sleeved on the outer circumference of the corresponding guide rods. The second overload protection sheet has a plurality of through holes corresponding to the plurality of guide rods, and one end of the guide rod away from the sleeve passes through the corresponding through hole and is located above the second overload protection sheet.

7. The chain clip overload protection device according to claim 6, characterized in that: A limiting block is sleeved on the outer periphery of one end of the guide rod away from the shaft sleeve, and the outer diameter of the limiting block is greater than the inner diameter of the through hole.

8. The chain clip overload protection device according to claim 1, characterized in that: An annular mounting portion is formed on the outer circumferential surface of the bottom end of the sleeve, and the mounting portion is provided with a plurality of arc-shaped waist-shaped holes, and the plurality of waist-shaped holes are distributed in a ring-shaped manner around the sleeve. The top end of the driving sprocket has a recess, and the bottom of the recess is provided with a plurality of circular holes corresponding to the plurality of waist-shaped holes, and sleeve fasteners are installed in the circular holes and the corresponding waist-shaped holes.

9. The chain clip overload protection device according to claim 1, characterized in that: The mechanical switch is detachably mounted on one end of the L-shaped bracket via an L-shaped bracket.

10. A biaxial stretching device, characterized in that: The invention comprises a chain clip overload protection device as claimed in any one of claims 1 to 9.

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