Belt unwinding and winding mechanism capable of automatically switching tension

Abstract

The utility model discloses a belt unwinding and winding mechanism capable of automatically switching pulling force, and relates to the technical field of belt unwinding and winding mechanisms, the belt unwinding and winding mechanism comprises a fixed-position driving wheel and a movable-position driven wheel, the driven wheel is located above the driving wheel, and a driving gear of the driving wheel is in meshing transmission with a driven gear of the driven wheel; a belt strip penetrates through the position between a driving pressing wheel of the driving wheel and a driven pressing wheel of the driven wheel, a force applying assembly is installed on an installation shaft of the driven wheel, the force applying assembly is connected with an adjusting driving mechanism, and the force applying assembly comprises a first-stage spring and a second-stage spring. The adjusting driving mechanism is used for controlling deformation of the first-stage spring or simultaneous deformation of the first-stage spring and the second-stage spring so as to adjust the meshing tightness degree of the driving gear and the driven gear, and then the contact force exerted on the belt by the driving pressing wheel and the driven pressing wheel is adjusted. The device can apply force to the belt in stages, so that the working efficiency is high, and long-time high load of the motor can be avoided.

Description

Technical Field

[0001] This application relates to the technical field of belt feeding and retracting mechanisms, specifically to a belt feeding and retracting mechanism capable of automatically switching tension. Background Technology

[0002] A strapping machine is a device that uses strapping tape to bundle items. The entire strapping process involves several steps: tape feeding, tape retraction, tensioning, and heat sealing. To ensure reliable tape retraction and tensioning, the common structure typically uses a pair of roller sets for both tape feeding / retraction and tensioning. These roller sets generally consist of a drive roller and driven rollers that can be against or away from the drive roller. To simplify the structure, strapping machines using only one pair of roller sets for both tape feeding / retraction and tensioning have emerged, such as CN103086000B. However, existing devices usually only provide single-stage force application. To tighten the tape, the contact force between the pair of roller sets is directly adjusted to the required force for pulling the tape. A high contact force between the roller sets results in a slow tape retraction speed, leading to low efficiency. Furthermore, it keeps the motor at high power for extended periods, consuming a lot of electricity and wasting resources. Prolonged high loads also shorten the motor's lifespan. Utility Model Content

[0003] In view of this, this application provides a belt feeding and retracting mechanism that can automatically switch the tension to solve the technical problem of low work efficiency caused by the single-stage force application in the prior art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A belt feeding and take-up mechanism capable of automatically switching tension includes a stationary drive wheel and a movable driven wheel. The driven wheel is located above the drive wheel. The drive gear of the drive wheel meshes with the driven gear of the driven wheel for transmission. The belt passes between the drive pressure wheel of the drive wheel and the driven pressure wheel of the driven wheel. A force-applying component is mounted on the mounting shaft of the driven wheel. The force-applying component is connected to an adjustment drive mechanism. The force-applying component includes a primary spring and a secondary spring. The adjustment drive mechanism is used to control the deformation of the primary spring or the simultaneous deformation of the primary and secondary springs to adjust the meshing tightness of the drive gear and the driven gear, thereby adjusting the contact force applied to the belt by the drive pressure wheel and the driven pressure wheel.

[0006] Furthermore, the force-applying assembly also includes a connecting rod and a spring sleeve fitted on the connecting rod. One end of the connecting rod is connected to the mounting shaft. Both the primary spring and the secondary spring are fitted on the connecting rod. The length of the primary spring is greater than that of the secondary spring. The spring sleeve is connected to the adjustment drive mechanism.

[0007] Furthermore, the connecting rod includes a connecting screw and an adjusting screw. The adjusting screw is connected to the mounting shaft, and the connecting screw is threadedly connected to the adjusting screw. The spring sleeve, the primary spring, and the secondary spring are all sleeved on the connecting screw.

[0008] Furthermore, the primary spring is located inside the secondary spring.

[0009] Furthermore, the connecting screw is threaded with a pre-compression adjusting nut that abuts against the spring sleeve.

[0010] Furthermore, the connecting screw is threaded with a locking nut that abuts against the adjusting screw.

[0011] Furthermore, the adjustment drive mechanism includes a swing arm with a swinging configuration and a drive cam mounted on one side of the swing arm. The swing arm is connected to a spring sleeve, and the drive cam has a first force-applying protrusion and a second force-applying protrusion arranged sequentially to contact the swing arm.

[0012] Furthermore, the height of the second force-adding protrusion is greater than that of the first force-adding protrusion, and the drive cam is also provided with a force-relieving notch. The second force-adding protrusion is located between the first force-adding protrusion and the force-relieving notch.

[0013] Furthermore, the mounting shaft is a driven eccentric shaft, and the driven wheel is rotatably mounted on the driven eccentric shaft so that the driven wheel can rotate and deflect.

[0014] As can be seen from the above technical solution, the advantages of this utility model are:

[0015] 1. In this application, a primary spring is used to achieve primary force application, ensuring that the belt can be reliably wound up. The simultaneous deformation of the primary and secondary springs further increases the contact force between the driving and driven pressure rollers, ensuring that the belt can be reliably pulled up. This phased process avoids the motor being in a high-power state for a long time, saving resources. Furthermore, the phased winding up and pulling up improves winding efficiency. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0017] Figure 1 This is a schematic diagram of the front view of this application.

[0018] Figure 2 This is a side view structural diagram of this application.

[0019] Figure 3 This is a schematic diagram of the driven eccentric shaft of this application.

[0020] Figure 4 This is a schematic diagram of the driven wheel in this application.

[0021] Figure 5 This is a schematic diagram of the drive wheel in this application.

[0022] Figure 6 This is a schematic diagram of the force-adding component of this application.

[0023] Figure 7 This is a schematic diagram of the drive cam in this application.

[0024] Explanation of reference numerals in the attached drawings: Base 1, Drive wheel 2, Drive gear 21, Drive pressure wheel 22, Driven wheel 3, Driven gear 31, Driven pressure wheel 32, Force-applying assembly 4, Spring sleeve 41, Lower connector 42, Connecting screw 43, Washer 44, First-stage spring 45, Second-stage spring 46, Pre-compression adjusting nut 47, Adjusting screw 48, Anti-reverse nut 49, Drive cam 5, First force-applying protrusion 51, Second force-applying protrusion 52, Force-relieving notch 53, Rocker arm 6, Roller 61, Driven eccentric shaft 7, Drive shaft 8, Coupling 9, Servo motor 10. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and their descriptions are used to explain this application, but are not intended to limit it.

[0026] refer to Figures 1 to 7 ,like Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, this embodiment provides a belt feeding and retracting mechanism capable of automatically switching tension, including a base 1, a stationary drive wheel 2 mounted on the base 1, and a movable driven wheel 3 mounted on the base 1. The driven wheel 3 is located above the drive wheel 2. The drive gear 21 of the drive wheel 2 meshes with the driven gear 31 of the driven wheel 3 for transmission. The belt passes between the drive pressure wheel 22 of the drive wheel 2 and the driven pressure wheel 32 of the driven wheel 3. The frictional force applied to the belt by the drive pressure wheel 22 and the driven pressure wheel 32 causes the belt to retract and tighten. A force-applying assembly 4 is mounted on the mounting shaft of the driven wheel 3. The force-applying assembly 4 is connected to the adjustment drive mechanism. The force-applying assembly 4 includes a primary spring 45 and a secondary spring 46. The adjustment drive mechanism is used to control the deformation of the primary spring 45 or the simultaneous deformation of the primary spring 45 and the secondary spring 46 to adjust the meshing tightness of the driving gear 21 and the driven gear 31, thereby adjusting the contact force applied to the belt by the driving pressure wheel 22 and the driven pressure wheel 32. The primary spring 45 and the secondary spring 46 can also be replaced by other elastic components.

[0027] One installation configuration of the driven wheel 3 is as follows: the mounting shaft of the driven wheel 3 is slidably mounted on the base 1, and the primary spring 45 and the secondary spring 46 are mounted on the side of the driven wheel 3 closer to the driving wheel 2. An adjustment drive mechanism is used to push the driven wheel 3 to move closer to the driving wheel 2. When the driven wheel 3 initially moves, it will drive the primary spring 45 to compress and deform. When the primary spring 45 is deformed to the same length as the secondary spring 46, the continued movement of the driven wheel 3 will cause the primary spring 45 and the secondary spring 46 to deform simultaneously. The adjustment drive mechanism can be a linear drive mechanism or a swing drive mechanism.

[0028] Another installation configuration of the driven wheel 3 is as follows: the mounting shaft of the driven wheel 3 is slidably mounted on the base 1, and the primary spring 45 and the secondary spring 46 are located on the side of the driven wheel 3 away from the driving wheel 2. The drooping sections of the primary spring 45 and the secondary spring 46 are connected to the corresponding sliders mounted on the base 1. The driven wheel 3 is moved closer to the driving wheel 2 by an adjustment drive mechanism. When the driven wheel 3 initially moves, it pushes the slider connected to the primary spring 45 to move, causing the primary spring 45 to stretch and deform. When the primary spring 45 is deformed to the same length as the secondary spring 46, the continued movement of the driven wheel 3 will cause the primary spring 45 and the secondary spring 46 to stretch and deform simultaneously. The adjustment drive mechanism can be a linear drive mechanism or a swing drive mechanism.

[0029] like Figure 1 and Figure 3 As shown, in this embodiment, preferably, the driven wheel 3 is installed as follows: the mounting shaft is a driven eccentric shaft 7, the driven eccentric shaft 7 is mounted on the base 1 through a bearing, and the driven wheel 3 is rotatably mounted on the driven eccentric shaft 7 through the bearing. When the driven eccentric shaft 7 rotates, it can drive the driven wheel 3 to rotate and deflect.

[0030] In this application, the drive wheel 2 is connected to the drive shaft 8 via a flat key. The drive shaft 8 is mounted on the base 1 via bearings. The drive shaft 8 is connected to the servo motor 10 via a coupling 9. When the servo motor 10 is activated, it drives the drive pressure wheel 22 and the driven pressure wheel 32 to rotate synchronously through the meshing of the drive gear 21 and the driven gear 31, so that the belt unwinding and belt pulling are reliable.

[0031] like Figure 6 As shown, in this embodiment, the force-applying component 4 also includes a connecting rod and a spring sleeve 41 sleeved on the connecting rod. One end of the connecting rod is connected to the mounting shaft. The primary spring 45 and the secondary spring 46 are both sleeved on the connecting rod. The length of the primary spring 45 is greater than that of the secondary spring 46. The spring sleeve 41 is connected to the adjustment drive mechanism. By driving the spring sleeve 41 to move, the primary spring 45 and the secondary spring 46 are compressed and deformed.

[0032] Specifically, the primary spring 45 and the secondary spring 46 are located inside the spring sleeve 41. The lower end of the spring sleeve 41 has a lower connector 42 connected to the adjustment drive mechanism, so that the primary spring 45 and the secondary spring 46 are hidden and safe to use. The side wall of the spring sleeve 41 is provided with observation strip holes for easy observation of the status of the primary spring 45 and the secondary spring 46.

[0033] In this embodiment, the connecting rod includes a connecting screw 43 and an adjusting screw 48. The adjusting screw 48 is hinged to the mounting shaft, and the connecting screw 43 is threaded to the adjusting screw 48. A spring sleeve 41, a primary spring 45, and a secondary spring 46 are all fitted onto the connecting screw 43, and a washer 44 is fitted onto the connecting screw 43 to abut against the lower ends of the primary spring 45 and the secondary spring 46. The connecting rod, composed of the connecting screw 43 and the adjusting screw 48, allows for adjustment of the connecting rod's length as needed, making installation more convenient and adaptable.

[0034] Preferably, in this embodiment, the primary spring 45 is located inside the secondary spring 46. This facilitates observation of the compression status of the primary spring 45 and the secondary spring 46.

[0035] In this application, a pre-compression adjusting nut 47 is threaded onto the connecting screw 43 and abuts against the spring sleeve 41. By turning the pre-compression adjusting nut 47, the pre-compression amount of the primary spring 45 can be adjusted. The pre-compression amount of the primary spring 45 can ensure that the driving gear 21 and the driven gear 31 maintain a stable meshing state during belt feeding, and that the belt can also have a certain contact friction force with the driving pressure roller 22 and the driven pressure roller 32 during belt feeding, so that the belt feeding process is continuous and stable.

[0036] In this application, a locking nut 49 is threaded onto the connecting screw 43, which abuts against the adjusting screw 48. The locking nut 49 prevents the connecting screw 43 from automatically rotating and loosening.

[0037] like Figure 2 and Figure 7In this embodiment, the adjustment drive mechanism includes a swing arm 6 and a drive cam 5 mounted on one side of the swing arm 6. The swing arm 6 has a roller 61 that works in conjunction with the drive cam 5. The swing arm 6 is hinged to the lower connector 42. The drive cam 5 has a first force-applying protrusion 51 and a second force-applying protrusion 52 that are arranged sequentially to contact the swing arm 6. The height of the second force-applying protrusion 52 is greater than that of the first force-applying protrusion 51. The swing amplitude of the swing arm 6 is adjusted by using force-applying protrusions of different heights, thereby adjusting the sliding displacement of the spring sleeve 41 relative to the connecting screw 43, and thus controlling the first-stage spring. Spring 45 or primary spring 45 and secondary spring 46 are compressed simultaneously. By setting the central angle of the convex top of the force-adding protrusion, the compression time of primary spring 45 and the simultaneous compression time of primary spring 45 and secondary spring 46 are controlled by mechanical structure without stopping the drive cam 5. The compression time of primary spring 45 is the tape unwinding and rewinding time, and the simultaneous compression time of primary spring 45 and secondary spring 46 is the tape pulling time. By controlling it in two stages, tape unwinding and rewinding are smooth and fast, and the servo motor 10 has low power, short tape pulling time, and short high load time.

[0038] The adjustment drive mechanism in this application can also be a linear drive mechanism.

[0039] In this embodiment, the drive cam 5 is also provided with a pressure relief notch 53, and the second pressure-applying protrusion 52 is located between the first pressure-applying protrusion 51 and the pressure relief notch 53. After the secondary pressure is applied, the driven pressure roller 32 can quickly relax the bag strip, allowing the belt head to quickly return to its original shape for reuse. The area between the pressure relief notch 53 and the first pressure-applying protrusion 51 is an arc segment. When the arc segment contacts the roller 61, the driven pressure roller 32 applies a certain preload, causing the belt to move. The friction between the belt and the driven pressure roller 32 and the driving pressure roller 22 drives the driving roller 2 and the driven roller 3 to rotate, thus stabilizing the belt feeding.

[0040] In use, as the belt advances, the arc segment of the drive cam 5 abuts against the roller 61 of the rocker arm 6. The driven pressure roller 32 applies a certain preload to the belt. The friction between the belt and the driven pressure roller 32 and the driving pressure roller 22 drives the driving roller 2 and the driven roller 3 to rotate. When belt unwinding is required, the drive cam 5 is rotated by a motor, causing the first force-applying protrusion 51 of the drive cam 5 to abut against the roller 61 of the rocker arm 6, deforming the first-stage spring 45, allowing the belt to reliably unwind and making the unwinding length controllable. When belt pulling is required... The drive cam 5 is rotated by a motor to make the second force-applying protrusion 52 of the drive cam 5 abut against the roller 61 of the rocker arm 6, so that the first-stage spring 45 and the second-stage spring 46 deform simultaneously, applying a sufficiently large force to the belt to stabilize the belt pulling and make the belt pulling length controllable. After the belt pulling is completed, the drive cam 5 is rotated by a motor to make the force-relieving notch 53 of the drive cam 5 rotate to the roller 61 of the rocker arm 6. When the belt needs to be fed, the drive cam 5 is rotated by a motor to make the arc segment of the drive cam 5 abut against the roller 61 of the rocker arm 6.

[0041] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to the embodiments of this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A take-up and pay-off mechanism capable of automatically switching the tension, characterized in that, The application relates to a belt tensioner, which comprises a driving wheel (2) and a driven wheel (3), the driven wheel (3) is located above the driving wheel (2), a driving gear (21) of the driving wheel (2) is in mesh transmission with a driven gear (31) of the driven wheel (3), a belt passes between a driving pressing wheel (22) of the driving wheel (2) and a driven pressing wheel (32) of the driven wheel (3), a force adding assembly (4) is arranged on a mounting shaft of the driven wheel (3), the force adding assembly (4) is connected with an adjusting driving mechanism, the force adding assembly (4) comprises a primary spring (45) and a secondary spring (46), the primary spring (45) is deformed or the primary spring (45) and the secondary spring (46) are simultaneously deformed to adjust the meshing tightness of the driving gear (21) and the driven gear (31) by the adjusting driving mechanism, and then the contact force degree of the driving pressing wheel (22) and the driven pressing wheel (32) on the belt is adjusted.

2. The power banding mechanism of claim 1, wherein, The force adding assembly (4) further comprises a connecting rod and a spring sleeve (41) sleeved on the connecting rod, one end of the connecting rod is connected with the mounting shaft, the primary spring (45) and the secondary spring (46) are both sleeved on the connecting rod, the length of the primary spring (45) is greater than that of the secondary spring (46), and the spring sleeve (41) is connected with the adjusting driving mechanism.

3. The power banding mechanism of claim 2, wherein, The connecting rod comprises a connecting screw (43) and an adjusting screw rod (48), the adjusting screw rod (48) is connected with the mounting shaft, the connecting screw (43) is in threaded connection with the adjusting screw rod (48), and the spring sleeve (41), the primary spring (45) and the secondary spring (46) are all sleeved on the connecting screw (43).

4. The power banding mechanism of claim 2, wherein, The primary spring (45) is located in the secondary spring (46).

5. The power banding mechanism of claim 3, wherein, A pre-compression adjusting nut (47) abutting against the spring sleeve (41) is in threaded connection on the connecting screw (43).

6. The power banding mechanism of claim 3, wherein, A retreat-stopping nut (49) abutting against the adjusting screw rod (48) is in threaded connection on the connecting screw (43).

7. The power banding mechanism of claim 2, wherein, The adjusting driving mechanism comprises a swing rod (6) swingly arranged and a driving cam (5) arranged on one side of the swing rod (6), the swing rod (6) is connected with the spring sleeve (41), and the driving cam (5) has a first force adding protruding part (51) and a second force adding protruding part (52) arranged in sequence and capable of contacting the swing rod (6).

8. The power banding mechanism of claim 7, wherein, The height of the second force adding protruding part (52) is greater than that of the first force adding protruding part (51), the driving cam (5) is further provided with a force unloading notch groove (53), and the second force adding protruding part (52) is located between the first force adding protruding part (51) and the force unloading notch groove (53).

9. The power banding mechanism of claim 1, wherein, The mounting shaft is a driven eccentric shaft (7), and the driven wheel (3) is rotatably arranged on the driven eccentric shaft (7) so that the driven wheel (3) can be rotated and offset.

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