Composite torsion sensor with speed measuring device

Abstract

The utility model discloses a kind of composite torsion sensors with speed measuring device, including elastomer, transmission mechanism and torsion cover cap.The elastomer is internally hollow structure, is formed with the shaft hole of axial penetration, its outer surface is attached with strain gauge, and the shaft hole bottom is fixed with the rotational speed sensor module containing magnetic induction element inside;The transmission mechanism includes rotatable and axially movable bolt, and the end of its insertion shaft hole is equipped with magnet.In initial state, the distance between magnet and rotational speed sensor module is greater than effective induction distance;When external torque drives bolt to rotate, it generates axial displacement by overcoming pre-tightening force, drives magnet to move to effective induction distance inside.At this time, rotational speed sensor module exports rotational speed signal by detecting the magnetic field change of rotating magnet, while elastomer generates deformation due to transmission torque, and strain gauge exports torsion signal by detecting resistance change.The utility model realizes the synchronous, common source measurement of torque and rotational speed, solves the problem of single function of traditional sensor.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology, specifically relating to a composite torque sensor capable of simultaneously measuring torque and rotational speed. Background Technology

[0002] Torque sensors are the core measuring components in torque testing equipment, and their performance directly determines the accuracy and reliability of the entire device. These devices are widely used for the calibration and testing of various torque tools, including electric and pneumatic screwdrivers and hand tools, which are indispensable in the automotive industry, aerospace manufacturing, and precision equipment assembly. Therefore, the performance of torque sensors is of paramount importance.

[0003] In practical applications, it has been found that the output characteristics of many torque tools (such as electric and pneumatic screwdrivers) are related to their torque and rotational speed. When testing the torque of a tool, users generally need to simultaneously obtain its rotational speed value. Only by comparing the actual measured value of the rotational speed with the set value can the performance parameters of the tool be fully calibrated and optimized to ensure that it works in its best condition.

[0004] However, traditional torque sensors on the market are limited in function, typically only outputting torque signals and failing to meet the requirement of synchronous, co-source measurement of rotational speed. If simultaneous rotational speed measurement is required, users must configure an additional independent rotational speed sensor. This not only increases system complexity and cost but also, because torque and rotational speed signals originate from different measurement points (non-co-source measurement), can lead to problems such as data asynchrony, installation inconvenience, and increased measurement errors. Therefore, developing a composite torque sensor capable of integrating synchronous torque and rotational speed measurement has become an urgent technical problem to be solved in this field. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a composite torque sensor with a speed measuring device to solve the technical problems of traditional torque sensors having a single function and being unable to measure torque and speed synchronously and from the same source.

[0006] The technical problem of this utility model is solved by the following technical solution: A composite torque sensor with a speed measuring device includes an elastic body and a transmission mechanism. The elastic body has a hollow internal structure with a through-hole along its axial direction. A strain gauge for detecting torque is attached to its outer surface. A speed sensor module is fixedly mounted at the bottom of the through-hole, and a magnetic induction element is disposed inside the speed sensor module. The transmission mechanism has a bolt that is driven to rotate by an external torque and can move along its axial direction. A magnet is disposed at one end of the bolt that extends into the through-hole. In the initial state, the magnet and the magnetic induction element of the speed sensor module are axially spaced by a distance greater than the effective distance of magnetic induction coupling. When the external torque drives the bolt to rotate, the bolt overcomes a preload and generates axial displacement, causing the magnet to move toward the speed sensor module and into the effective distance of magnetic induction coupling. At this time, the speed sensor module outputs a speed signal by detecting the change in the magnetic field generated by the rotating magnet. Simultaneously, the elastic body deforms due to the transmission of torque, and the strain gauge outputs a torque signal by detecting the change in its resistance.

[0007] The transmission mechanism includes: a bolt; a mounting plate that is threaded to the shank of the bolt and positioned on top of the elastic body; a planar bearing that is sleeved on the outside of the bolt; and a spring that is sleeved on the outside of the bolt and compressed between the mounting plate and the planar bearing.

[0008] The axial displacement of the bolt is configured such that when the bolt moves to its maximum displacement, a safe gap is still maintained between the magnet and the speed sensor module.

[0009] The preload of the spring is set such that the bolt will only produce axial displacement when the external torque reaches a set threshold, so that the magnet enters the effective distance for magnetic induction coupling with the speed sensor module.

[0010] The elastomer is a one-piece molded structure, and its outer surface is provided with a strain region that deforms due to torque, and the strain gauge is attached to the strain region.

[0011] The strain region is located in the axial middle of the elastic body.

[0012] The elastomer includes a mounting portion and a deformation portion; the mounting portion is located at the top of the elastomer and is positioned and mounted with a mounting plate; the deformation portion is located in the middle of the elastomer, and the strain gauge is attached to its outer surface.

[0013] It also includes a torque cover, which is sleeved on the elastic body and forms a positioning fit and circumferential limit with the bottom of the elastic body; the torque cover has a wire hole for leading out the torque lead wire of the strain gauge.

[0014] The bottom of the elastic body is provided with a non-circular shaft, and the bottom of the torsion cover is provided with a non-circular hole that matches the non-circular shaft. The cooperation between the non-circular shaft and the non-circular hole realizes the positioning and circumferential limiting.

[0015] It also includes a signal output interface, wherein the strain gauge and speed sensor module are connected to an external circuit via ribbon cables or connectors for synchronously outputting torque and speed signals.

[0016] Compared with the prior art, the composite torque sensor with speed measuring device provided by this utility model has the following advantages: Firstly, the core of this invention lies in its functional integration and synchronous, same-source measurement: Through a unique structural design, it integrates a torque sensing unit and a speed sensing unit into a single unit. By utilizing the hollow shaft hole in the elastic body, the built-in speed sensor module, and the synergistic effect with the magnet in the transmission mechanism, synchronous and same-source acquisition of torque and speed signals is achieved. That is, the two signals originate from the same measurement action and physical structure, ensuring a high degree of data synchronization and accuracy, fundamentally solving the problem of the single function of traditional torque sensors.

[0017] Secondly, the structure is compact and the measurement is accurate: the transmission mechanism utilizes the rotation and axial movement of the bolts, combined with the spring preload, to ensure that the magnet only enters the sensing area under effective torque. This not only constitutes a non-contact speed measurement triggering mechanism but also avoids false triggering. The entire sensor structure is rationally laid out and compact in size, avoiding problems such as messy wiring and bulky structure caused by external sensors, while ensuring the accuracy and reliability of the measurement. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 for Figure 1 3D exploded view.

[0020] Figure 3 This is a schematic diagram of the installation structure of the elastomer.

[0021] Figure 4 This is a schematic diagram of a one-piece molded elastomer.

[0022] Figure 5 This is a schematic diagram of the structure of an elastomer assembled from parts.

[0023] Figure 6 This is a schematic diagram of the transmission mechanism.

[0024] Figure 7 for Figure 6 3D exploded view. Detailed Implementation

[0025] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0026] like Figures 1-7 As shown, 1. Elastomer, 101. Mounting part, 102. Deformation part, 11. Screw hole, 12. Shaft hole, 13. Strain zone, 14. Non-circular shaft, 15. Mounting groove, 2. Transmission mechanism, 21. Bolt, 22. Mounting plate, 23. Spring, 24. Surface bearing, 3. Torque cover, 31. Wire hole, 4. Mounting plate, 5. Strain gauge, 51. Torque lead wire, 6. Speed ​​sensor module, 61. Speed ​​lead wire, 7. Magnet. The same labels in each figure represent the same components.

[0027] A composite torque sensor with a speed measuring device, such as Figure 1 , Figure 2 As shown, it can be widely used for the calibration and testing of various torque tools such as electric and pneumatic screwdrivers and manual tools. Its structure includes an elastomer 1, a transmission mechanism 2, and a torque cover 3.

[0028] For ease of description, this embodiment uses Figure 1 The top of the view shown is the top of the elastic body 1, and the bottom is the bottom. The torsion cover 3 is fitted over the elastic body 1, covering its bottom and fixing the bottom of the elastic body; the elastic body is rotatably supported on a mounting plate 4 by a bearing, and the mounting plate is fixedly connected to the torsion cover 3 after it is covered; the transmission mechanism 2 is installed on the top of the elastic body 1.

[0029] The elastic body 1 has an internal hollow structure and has a through hole 12 extending along its axial direction.

[0030] The elastomer can be implemented in the following two preferred embodiments: Implementation Method 1 (One-piece molding): such as Figure 4 As shown, the elastomer 1 is a one-piece molded structure. Its outer surface is provided with strain regions 13 that deform due to torque. These strain regions are preferably located in the axial middle of the elastomer 1, specifically on two symmetrical sides. Strain gauges 5 are attached to both strain regions 13, which can be used to detect the torque borne by the elastomer 1.

[0031] Implementation Method Two (Combined): such as Figure 5As shown, the elastomer 1 is composed of a mounting part 101 and a deformation part 102. The mounting part 101 is located at the top of the elastomer 1, and the deformation part 102 is located in the middle. The deformation part and the mounting part can be connected and fixed by a positioning and fitting structure, such as a square shaft and a square hole, or a hexagonal shaft and a hexagonal hole. The outer surface of the deformation part 102 is also provided with two symmetrically positioned strain regions 13, and strain gauges 5 are attached thereon. When assembled, its overall shape is consistent with that of the integrally formed elastomer.

[0032] A speed sensor module 6 is fixedly installed at the bottom of the shaft hole 12 of the elastic body 1. The speed sensor module contains a magnetic induction element, such as a speed sensor chip that integrates a Hall element.

[0033] The torsion cover 3 forms a positioning fit and circumferential limit with the bottom of the elastic body 1, that is, the torsion cover 3 fixes the bottom of the elastic body 1 in a fixed state. In a preferred embodiment, such as Figure 1 , Figure 4 As shown, the bottom of the elastic body 1 is provided with a non-circular shaft 14, and the bottom of the torque cover 3 is provided with a matching non-circular hole, such as a flat shaft and a flat hole. Therefore, the positioning fit and circumferential limit can be achieved by the cooperation of the non-circular shaft and the non-circular hole. Since the speed sensor module 6 located at the bottom of the elastic body 1 is directly exposed in the non-circular hole, its speed lead wire 61 can be directly led out.

[0034] The torque cover 3 has a wire hole 31 for leading out the torque lead wire 51 of the strain gauge 5.

[0035] The transmission mechanism 2 includes a bolt 21, a mounting plate 22, a plane bearing 24, and a spring 23.

[0036] The mounting plate 22 is threadedly connected to the shank of the bolt 21 and positioned within the mounting groove 15 on the top of the elastomer 1. The mounting plate 22 can also be fixed by inserting fastening screws into the pre-drilled screw holes 11 on the side of the mounting groove. Therefore, when the bolt 21 rotates, it will directly pass through the mounting plate 22 and extend into the shaft hole 12 of the elastomer 1.

[0037] A magnet 7 is provided at one end of the bolt 21 that extends into the shaft hole 12. The magnet can be fixed to the end of the bolt by means of bonding, interference fit or snap-fit.

[0038] The planar bearing 24 and spring 23 are sequentially sleeved around the bolt 21. The spring 23 is compressed between the mounting plate 22 and the planar bearing 24, thereby providing a preload force to the bolt 21. The planar bearing 24 ensures that the bolt 21 can still rotate flexibly while bearing the preload force of the spring 23.

[0039] The core working principle of this utility model is as follows: In the initial state, the magnet 7 and the magnetic induction element of the speed sensor module 6 are axially spaced by a distance, which is greater than the effective distance of magnetic induction coupling.

[0040] When the external torque drives the bolt 21 to rotate, the bolt, through its threaded engagement with the mounting plate 22, overcomes the preload of the spring 23 and generates axial displacement, thereby driving the magnet 7 to move toward the speed sensor module 6.

[0041] When the magnet 7 enters the effective distance of magnetic induction coupling, the rotating magnet 7 will cause a change in the magnetic field. The speed sensor module 6 detects this change and outputs a speed signal.

[0042] At the same time, the torque is transmitted to the elastic body 1 through the transmission mechanism 2. Since the torque cover 3 restricts the rotation of the bottom of the elastic body 1, the strain area 13 is deformed. The strain gauge 5 attached to the strain area 13 can output a torque signal by detecting the change in its own resistance.

[0043] The signal output generated by the change in magnetic field refers to the change in the electrical signal of the Hall element caused by the magnet 7 approaching the speed sensor module 6, which is then converted into a speed signal output to achieve the function of speed measurement.

[0044] The principle of measuring rotational speed using the Hall effect is as follows: First, the Hall effect principle: The movement of charge carriers generates a magnetic field. When a magnet approaches a Hall element, the magnetic field of charge carriers is distorted. This disrupts the straight-line flow of charge carriers. The force that disrupts the direction of charge carrier flow is called the Lorentz force.

[0045] The Hall effect principle states that when a current-carrying conductor or semiconductor is introduced into a perpendicular magnetic field, the voltage can be measured at a position perpendicular to the current path, as shown in the following formula:

[0046] In the formula, R H It is the Hall coefficient; I It is electric current; B It is the magnetic flux density; d It refers to the thickness of the conductor being cut.

[0047] The change in voltage inside the Hall chip generates a sinusoidal pulse signal, which the speed sensor module can then convert into a speed value based on the period of these pulse signals.

[0048] The strain gauge 5 mounted on the elastic body 1 is also a sensor. It has a certain resistance value, and its resistance value changes when it is deformed by an external force. The strain gauge is typically designed based on the Wheatstone bridge principle to test torque values.

[0049] Strain gauges exhibit very small resistance changes during operation. Therefore, for strain measurement, a Wheatstone bridge is constructed to convert the resistance change into a voltage change. Assuming the resistance is... R 1 , R 2 , R 3 and R 4 The excitation voltage V is E Then, the output voltage V can be obtained through the following equation, i.e. The voltage value reflects the deformation of the strain gauge, and the torque on the elastic body can be calculated from the voltage value. This is the principle of the strain gauge sensor.

[0050] Furthermore, based on the above structure, this utility model also has preferred features, namely, it has a safety and triggering mechanism: First, it has a safety clearance, that is, the axial displacement of bolt 21 is designed such that when it moves to the maximum displacement, a safety clearance is still maintained between magnet 7 and speed sensor module 6 to prevent physical collision between the two. Secondly, it has a trigger threshold, meaning the preload of spring 23 is set so that bolt 21 will only undergo axial displacement and bring magnet 7 into the effective distance for magnetic induction coupling with speed sensor module 6 when the external torque reaches a set threshold. This constitutes a non-contact intelligent trigger speed measurement mechanism.

[0051] The strain gauge 5 and the speed sensor module 6 can be connected to an external circuit via ribbon cables or connectors, and synchronously output torque and speed signals through a signal output interface.

[0052] After the above structural improvements, the present invention mainly has the following beneficial effects: Firstly, functional integration and synchronous measurement from the same source: The core of this invention lies in its unique structural design, which integrates the torque sensing unit and the speed sensing unit into one unit. Through the hollow shaft hole 12 in the elastic body 1, the built-in speed sensor module 6, and the synergistic effect with the magnet of the transmission mechanism, synchronous and co-source acquisition of torque and speed signals is achieved. That is, the two signals originate from the same measurement action and physical structure, ensuring a high degree of data synchronization and accuracy, fundamentally solving the problem of the single function of traditional torque sensors.

[0053] Secondly, the structure is compact and the measurement is accurate: the transmission mechanism uses the rotation and axial movement of the bolt 21, combined with the preload of the spring 23, so that the magnet 7 only enters the sensing area under the action of effective torque. This not only constitutes the triggering mechanism of non-contact speed measurement, but also avoids false triggering.

[0054] The sensor structure is rationally laid out and compact in size, avoiding problems such as messy wiring and bulky structure caused by external sensors, while ensuring the accuracy and reliability of the measurement.

[0055] The above are merely preferred embodiments of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are within its protection scope. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within its protection scope.

Claims

1. A composite torque sensor with a speed measuring device, comprising an elastic body (1) and a transmission mechanism (2), characterized in that, The elastic body (1) has an internal hollow structure and a shaft hole (12) that runs through it along its axial direction. A strain gauge (5) for detecting torque is attached to its outer surface. A speed sensor module (6) is fixedly installed at the bottom of the shaft hole (12). A magnetic induction element is installed inside the speed sensor module. The transmission mechanism (2) has a bolt (21) that is driven to rotate by an external torque and can move along its axial direction, and a magnet (7) is provided at one end of the bolt that extends into the shaft hole (12). In the initial state, the magnet (7) and the magnetic induction element of the speed sensor module (6) are axially spaced by a distance greater than the effective distance of magnetic induction coupling. When the external torque drives the bolt (21) to rotate, the bolt overcomes a preload and generates an axial displacement, which drives the magnet (7) to move toward the speed sensor module (6) and enter the effective distance of magnetic induction coupling. At this time, the speed sensor module (6) outputs a speed signal by detecting the change in the magnetic field generated by the rotating magnet (7). At the same time, the elastic body (1) deforms due to the transmission of torque, and the strain gauge (5) outputs a torque signal by detecting the change in its resistance.

2. A composite torque sensor with a speed measuring device according to claim 1, characterized in that, The transmission mechanism (2) includes: Bolt (21); Mounting plate (22), which is threaded to the shank of bolt (21) and positioned on top of the elastomer (1); A planar bearing (24) is fitted over the bolt (21); A spring (23) is fitted over the bolt (21) and compressed between the mounting plate (22) and the planar bearing (24).

3. A composite torque sensor with a speed measuring device according to claim 2, characterized in that, The axial displacement of the bolt (21) is configured such that when the bolt (21) moves to its maximum displacement, a safe gap is still maintained between the magnet (7) and the speed sensor module (6).

4. A composite torque sensor with a speed measuring device according to claim 2, characterized in that, The preload of the spring (23) is set such that the bolt (21) will only produce axial displacement when the external torque reaches a set threshold, so that the magnet (7) enters the effective distance of magnetic induction coupling with the speed sensor module (6).

5. A composite torque sensor with a speed measuring device according to claim 1, characterized in that, The elastomer (1) is an integrally molded structure, and its outer surface is provided with a strain region (13) that deforms due to torque, and the strain gauge (5) is attached to the strain region (13).

6. A composite torque sensor with a speed measuring device according to claim 5, characterized in that, The strain region (13) is located in the axial middle of the elastic body (1).

7. A composite torque sensor with a speed measuring device according to claim 1, characterized in that, The elastic body (1) includes a mounting part (101) and a deformation part (102); the mounting part (101) is located at the top of the elastic body (1) and forms a positioning installation with the mounting plate (22); the deformation part (102) is located in the middle of the elastic body (1), and the strain gauge (5) is attached to its outer surface.

8. A composite torque sensor with a speed measuring device according to claim 1, characterized in that, It also includes a torque cover (3), which is sleeved on the outside of the elastic body (1) and forms a positioning fit and circumferential limit with the bottom of the elastic body (1); the torque cover (3) is provided with a wire hole (31) for leading out the torque lead wire (51) of the strain gauge (5).

9. A composite torque sensor with a speed measuring device according to claim 8, characterized in that, The bottom of the elastic body (1) is provided with a non-circular shaft (14), and the bottom of the torque cover (3) is provided with a non-circular hole that matches the non-circular shaft (14). The cooperation between the non-circular shaft (14) and the non-circular hole realizes the positioning and circumferential limiting.

10. A composite torque sensor with a speed measuring device according to claim 1, characterized in that, It also includes a signal output interface, wherein the strain gauge (5) and the speed sensor module (6) are connected to an external circuit via a ribbon cable or connector for synchronously outputting torque and speed signals.

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