Overload detection device suitable for motor transmission

Abstract

The invention discloses an overload detection device suitable for motor transmission, which comprises a driving unit, a bidirectional force sensor and a signal processing unit, and is characterized in that the driving unit comprises a power output shaft connected with an equipment main body and a power source for driving the power output shaft; one end of the bidirectional force sensor is connected with a stress structure of a power source through a first force transmission mechanism, the other end of the bidirectional force sensor is connected with an equipment body through a second force transmission mechanism, and the signal processing unit is configured to generate an overload signal based on a force signal output by the bidirectional force sensor. Two-way detection of tension and pressure is supported through the two-way force sensor, jamming of the cargo carrying table can be monitored, jamming of the balance weight can also be detected, and the device is suitable for various complex working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent logistics, and particularly relates to an overload detection device applicable to motor drive. Background Art

[0002] Each device has an essential parameter of the maximum rated load, which is particularly important for lifting equipment. In actual use, there is a dangerous situation where an operator puts goods heavier than the maximum rated load into the equipment and makes it run. In addition, during the lifting operation of equipment equipped with a lifting function, the lifting may be jammed due to external interference or loose goods, which is also very dangerous.

[0003] Currently, there are two common solutions for overload detection devices: One is to design a spring structure at the lifting point in cooperation with a toggle switch. When the lifted object is overweight and overloaded, the spring undergoes elastic deformation to trigger the toggle switch to send an overload signal. However, this overload detection device with a spring structure has obvious drawbacks. The spring deformation is large, which will reduce the positioning accuracy in actual use and is also prone to situations of "non-triggering" or "false triggering". Moreover, when there are multiple lifting points on the same device, multiple overload detection devices need to be equipped, which will lead to unstable signals and extremely difficult calibration. At the same time, this device is installed at the lifting point, making daily maintenance and spare part replacement difficult.

[0004] The other is to design a pin shaft with built-in strain gauges and an integrated PCB board at the lifting point. When the lifted object is overweight and overloaded, the strain gauges in the pin shaft undergo a small amount of elastic deformation, affecting the magnitude of the internal current. When the current reaches the set value, an overload signal is sent. However, in this solution, the stress direction of the lifting point strain pin shaft is fixed, and when the reverse component on the lifting rope gets stuck (such as when the counterweight rises and gets stuck), it cannot be detected. Similarly, in a multi-lifting-point device, multiple devices are required, resulting in problems of unstable signals and difficult calibration, and being installed at the lifting point is not conducive to daily maintenance and spare part replacement.

[0005] Therefore, how to solve the deficiencies existing in the above-mentioned prior art has become the subject to be studied and solved in this application. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an overload detection device applicable to motor drive.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] An overload detection device applicable to motor drive, comprising:

[0009] A drive unit, which includes a power output shaft connected to the equipment main body and a power source for driving the power output shaft;

[0010] A bidirectional force sensor, one end of which is connected to the force-bearing structure of the power source through a first force transmission mechanism, and the other end is connected to the device main body through a second force transmission mechanism;

[0011] A signal processing unit configured to generate an overload signal based on the force signal output by the bidirectional force sensor.

[0012] Furthermore, the power source includes a motor, and the power output shaft is the drive shaft of the motor.

[0013] Furthermore, the first force transmission mechanism includes a first torsion arm link and a first torsion arm mounting seat. The first torsion arm mounting seat is mounted on the outer shell of the motor through a first fixing bolt. One end of the first torsion arm link is connected to the first torsion arm mounting seat, and the other end is connected to the input end of the bidirectional force sensor.

[0014] Furthermore, the second force transmission mechanism includes a second torsion arm link and a second torsion arm mounting seat. The second torsion arm mounting seat is mounted on the device main body through a second fixing bolt. One end of the second torsion arm link is connected to the second torsion arm mounting seat, and the other end is connected to the output end of the bidirectional force sensor.

[0015] Furthermore, the drive shaft is mounted on a pedestal bearing, and the pedestal bearing is mounted on the device main body through a third fixing bolt.

[0016] Furthermore, a synchronous pulley is mounted on the drive shaft.

[0017] Furthermore, the signal processing unit includes a threshold comparison module and a determination output module. The threshold comparison module is configured to compare the force signal with a preset tensile threshold and pressure threshold; the determination output module is configured to generate an overload signal when the force signal exceeds any one of the thresholds.

[0018] Furthermore, the bidirectional force sensor is a strain gauge sensor, including an elastic body and strain gauges attached to the surface of the elastic body. The strain gauges are configured to convert the deformation of the elastic body into an electrical signal.

[0019] Furthermore, the bidirectional force sensor, the first force transmission mechanism, and the second force transmission mechanism are integrated within the visual range of the maintenance platform on the side of the motor.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: By detecting overload through a bidirectional force sensor, the problems caused by the deformation of the mechanical structure are avoided, thereby ensuring the operation accuracy of the device, effectively eliminating the phenomena of "non-triggering" or "false triggering", ensuring accurate and reliable detection. The bidirectional force sensor supports bidirectional detection of tensile force and pressure, can monitor both the jamming of the loading platform and the jamming of the counterweight, and is applicable to various complex working conditions. In addition, the overload detection device is installed at the position of the motor, and can be synchronously detected when the motor is inspected on the maintenance platform, greatly simplifying the maintenance process, reducing the maintenance cost, and improving the operation and maintenance efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Attached Figure 1 is a structural schematic diagram of an embodiment of the present application.

[0023] Description of the reference numerals and components involved in the drawings:

[0024] 1. Driving unit; 11. Motor; 12. Driving shaft; 2. Bidirectional force sensor; 3. First torsion arm connecting rod; 4. First torsion arm mounting seat; 5. First fixing bolt; 6. Second torsion arm connecting rod; 7. Second torsion arm mounting seat; 8. Second fixing bolt; 9. Pillow block bearing; 10. Third fixing bolt; 13. Synchronous pulley. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Hereinafter, the technical solutions of the present invention will be clearly and completely described through specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] Refer to the attached Figure 1 As shown, an overload detection device applicable to motor drive includes a driving unit 1, a bidirectional force sensor 2 and a signal processing unit. The driving unit 1 includes a power output shaft connected to the device main body and a power source for driving the power output shaft. One end of the bidirectional force sensor is connected to the force-bearing structure of the power source through a first force transmission mechanism, and the other end is connected to the device main body through a second force transmission mechanism. The signal processing unit is configured to generate an overload signal based on the force signal output by the bidirectional force sensor.

[0027] Among them, the power source includes the motor 11, the power output shaft is the drive shaft 12 of the motor 11, the first force transmission mechanism includes the first torsion arm link 3 and the first torsion arm mounting seat 4. The first torsion arm mounting seat 4 is mounted on the housing of the motor 11 through the first fixing bolt 5. One end of the first torsion arm link 3 is connected to the first torsion arm mounting seat 4, and the other end is connected to the input end of the bidirectional force sensor 2. The second force transmission mechanism includes the second torsion arm link 6 and the second torsion arm mounting seat 7. The second torsion arm mounting seat 7 is mounted on the equipment main body through the second fixing bolt 8. One end of the second torsion arm link 6 is connected to the second torsion arm mounting seat 7, and the other end is connected to the output end of the bidirectional force sensor 2. The motor 11 outputs torque through the drive shaft 12 to drive the equipment to operate. Preferably, the first torsion arm mounting seat 4 is rigidly fixed on the housing of the motor 11 through the first fixing bolt 5. One end of the first torsion arm link 3 is hinged to the first torsion arm mounting seat 4, and the other end is connected to the input end of the bidirectional force sensor 2, forming a tensile force transmission path from the motor housing to the first torsion arm link 3 and then to the bidirectional force sensor 2. The second torsion arm mounting seat 7 is fixed on the equipment main body through the second fixing bolt 8. One end of the second torsion arm link 6 is hinged to the second torsion arm mounting seat 7, and the other end is connected to the output end of the bidirectional force sensor 2, forming a pressure transmission path from the bidirectional force sensor 2 to the second torsion arm link and then to the equipment main body.

[0028] Preferably, the bidirectional force sensor 2 is a strain type sensor, including an elastic body and strain gauges attached to the surface of the elastic body. The strain gauges are configured to convert the deformation of the elastic body into an electrical signal. The elastic body functions as a force-deformation conversion element, and its deformation has a linear relationship with the external load. The strain gauges are attached to the surface of the elastic body and are composed of metal resistance wires or semiconductor materials. When the elastic body deforms, the strain gauges are stretched or compressed accordingly, resulting in a change in their resistance values. The resistance increases during stretching and decreases during compression, that is, the strain effect.

[0029] When the device is operating normally, the torque of the motor 11 is transmitted to the load through the drive shaft 12. At this time, only the torque reaction force of the motor 11 housing itself is borne, and the two-way force sensor 2 is in a balanced state under force. Tensile overload: If the loading platform cannot move due to overweight or jamming, the continuous output of torque by the motor 11 will cause the drive shaft 12 to be blocked, and the torque arm will generate abnormal tensile force in the stretching direction. This tensile force is transmitted to the input end of the two-way force sensor 2 through the first torque arm connecting rod 3. The strain gauge inside the two-way force sensor 2 deforms, resulting in a change in resistance value, and an electrical signal proportional to the tensile force is output. Pressure overload: If the counterweight system cannot fall back due to jamming, the motor 11 needs to output reverse torque to overcome the resistance, and the torque arm will generate abnormal pressure in the compression direction. This pressure is transmitted to the output end of the two-way force sensor 2 through the second torque arm connecting rod 6. The two-way force sensor 2 detects the pressure signal through reverse deformation and outputs an electrical signal proportional to the pressure. The two-way monitoring of tensile force and pressure is realized through the same sensor. In the tensile force mode, it can capture the abnormal tensile force of the motor torque arm when the loading platform is stuck in real time, avoiding potential safety hazards caused by overweight or lifting jamming of the goods. In the pressure mode, it accurately monitors the reverse pressure generated when the counterweight system is stuck, solves the defect that the traditional single-way detection scheme cannot identify reverse loads, and covers the overload monitoring requirements of all working conditions of lifting equipment.

[0030] Force transmission path:

[0031] Tensile force scenario: From the motor 11 housing to the first torque arm mounting seat 4 to the first torque arm connecting rod 3 to the input end of the two-way force sensor 2 to the elastic body of the sensor being stretched to the output end of the sensor to the second torque arm connecting rod 6 to the second torque arm mounting seat 7 to the equipment main body.

[0032] Pressure scenario: From the motor 11 housing to the first torque arm mounting seat 4 to the first torque arm connecting rod 3 to the input end of the two-way force sensor 2 to the elastic body of the sensor being compressed to the output end of the sensor to the second torque arm connecting rod 6 to the second torque arm mounting seat 7 to the equipment main body.

[0033] Preferably, the signal processing unit of this embodiment includes a threshold comparison module and a determination output module. The threshold comparison module is configured to compare the force signal with a preset tensile force threshold and pressure threshold, and the determination output module is configured to generate an overload signal when the force signal exceeds any threshold.

[0034] Preferably, as shown in the attached Figure 1 As shown, through the rigid connection of the pillow block bearing 9 with the equipment main body in this embodiment, the stable support and torque transmission of the drive shaft 12 are realized. The pillow block bearing 9 is installed on the equipment main body through the third fixing bolt 10. The combination of the pillow block bearing 9 and the third fixing bolt 10 constitutes the rigid support system of the drive shaft 12, and its core function is to ensure the stable transmission of the torque of the motor 11, suppress vibration and facilitate maintenance.

[0035] Preferably, refer to the appendix Figure 1 As shown, in this embodiment, by integrating the synchronous pulley 13 on the drive shaft 12, the efficient transmission of the torque of the motor 11 and the coordinated work of overload protection are realized. The synchronous pulley 13 transmits the torque output by the motor 11 to the loading platform or the counterweight system.

[0036] Preferably, refer to the appendix Figure 1 As shown, the lengths of the first torsion arm link 3 and the second torsion arm link 6 in this embodiment are equal, and the connection points of both to the bidirectional force sensor 2 are located on the same force axis. The design of equal-length links and coaxial lines eliminates the non-axial force interference at the root through mechanical symmetry and structural constraints, which is the basis for realizing high-precision bidirectional force detection. This design not only improves the reliability of overload detection, but also reduces the manufacturing and maintenance costs through a standardized structure, and is especially suitable for industrial scenarios with high requirements for precision and stability.

[0037] Preferably, refer to the appendix Figure 1 As shown, the bidirectional force sensor 2, the first torsion arm link 3 and the second torsion arm link 6 in this embodiment are integrated within the visible range of the maintenance platform on the side of the motor 11.

[0038] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An overload detection device applicable to motor drive, characterized in that, Comprising: A drive unit, which includes a power output shaft connected to the device body and a power source for driving the power output shaft; A bidirectional force sensor, one end of which is connected to the force-bearing structure of the power source through a first force transmission mechanism, and the other end is connected to the device body through a second force transmission mechanism; A signal processing unit configured to generate an overload signal based on the force signal output by the bidirectional force sensor.

2. The overload detection device applicable to motor drive according to claim 1, characterized in that The power source includes a motor, and the power output shaft is the drive shaft of the motor.

3. An overload detection device applicable to motor drive according to claim 2, characterized in that, The first force transmission mechanism includes a first torsion arm link and a first torsion arm mounting seat. The first torsion arm mounting seat is mounted on the outer shell of the motor through a first fixing bolt. One end of the first torsion arm link is connected to the first torsion arm mounting seat, and the other end is connected to the input end of the bidirectional force sensor.

4. The overload detection device applicable to motor drive according to claim 2, characterized in that, The second force transmission mechanism includes a second torsion arm link and a second torsion arm mounting seat. The second torsion arm mounting seat is mounted on the device body through a second fixing bolt. One end of the second torsion arm link is connected to the second torsion arm mounting seat, and the other end is connected to the output end of the bidirectional force sensor.

5. An overload detection device applicable to motor drive according to claim 2, characterized in that, The drive shaft is mounted on a pedestal bearing, and the pedestal bearing is mounted on the device body through a third fixing bolt.

6. An overload detection device applicable to motor drive according to claim 2, characterized in that, A synchronous pulley is mounted on the drive shaft.

7. The overload detection device applicable to motor drive according to claim 2, characterized in that, The signal processing unit includes a threshold comparison module and a determination output module. The threshold comparison module is configured to compare the force signal with a preset tensile threshold and a pressure threshold; The determination output module is configured to generate an overload signal when the force signal exceeds any one of the thresholds.

8. An overload detection device applicable to motor drive according to claim 2, characterized in that, The bidirectional force sensor is a strain gauge sensor, which includes an elastic body and strain gauges attached to the surface of the elastic body. The strain gauges are configured to convert the deformation of the elastic body into an electrical signal.

9. The overload detection device applicable to motor drive according to claim 2, characterized in that, The bidirectional force sensor, the first force transmission mechanism and the second force transmission mechanism are integrated within the visual range of the maintenance platform on the side of the motor.

Images