Impact wrench calibration device

Abstract

The utility model provides a kind of impact wrench calibration device;It is related to the field of testing equipment, in view of the problem that current impact wrench calibration device is poor in adaptability, sensor support is formed sliding pair by slider and guide rail cooperation, can be along guide rail flexible movement, it is convenient to adjust and the distance of adapter sleeve, to adapt different torque sensor, torque sensor is detachably installed in sensor support, the third joint of its measuring end is connected with transmission assembly, both realize torque data acquisition, and it is convenient to replace and maintain sensor, for the impact wrench of different torque range, without replacing complete set of device, only need to replace corresponding range sensor to complete adaptation, the second joint of adapter sleeve and the third joint of torque sensor are respectively connected to the both ends of axial elastic coupling, as the flexible buffer bridge of torque transmission, axial elastic characteristic can absorb impact load, while ensuring torque stable transmission, buffer protection and data accuracy are considered.

Description

Technical Field

[0001] This utility model relates to the field of calibration equipment, and in particular to an impact wrench calibration device. Background Technology

[0002] Threaded connections reliably connect two or more components by controlling the axial preload within an appropriate range. The greater the axial preload, the better the threaded pair's resistance to loosening and fatigue. Since the axial preload is an internal force, it is inconvenient to directly detect and control. During torque application, the axial preload is generally controlled indirectly within a qualified range using methods or processes such as the torque method, torque-angle method, and yield point method. Currently, one method for controlling the axial preload is to apply torque using an impact wrench. This involves a prime mover driving the active part of the impact mechanism (including the drive shaft, main pressure spring, and active impact block) via a reduction mechanism, which in turn drives the driven part (including the driven impact block and sleeve) through the engagement of the jaw clamp to apply torque to the threaded pair. When the threaded joint reaches its rest stroke (at which point the threaded joint end is not in contact with the washer or workpiece), the torque application exceeds its static torque. The slope of the torque with respect to the torsion angle increases dramatically. The active impact block begins to overcome the initial pressure of the main pressure spring and moves axially. When it exceeds the jaw clamp height, the active impact block disengages from the driven impact block. The driven impact block then drives the sleeve to perform intermittent rotational impacts on the threaded joint to be tightened. The threaded joint is finally tightened by the superposition of multiple impact torques. This torque application process is a dynamic process of continuous torque accumulation, and this torque is called "accumulated torque." This "accumulated torque" is an important indicator for evaluating the quality of on-site torque application operations and has significant reference value in related threaded connection research.

[0003] The working characteristics of impact wrenches make it difficult to detect and calibrate their output torque. Existing technologies disclose some calibration devices for impact wrenches, which establish various parameter relationship curves of bolts in the elastic stage to achieve online calibration of controllable torque impact wrenches for the working environment of torque application operations and the threaded pairs and workpieces on site. However, the calibration method is relatively complex. In some standard verification operation scenarios, it is necessary to quickly verify the torque of impact wrenches. During the verification process, the same equipment needs to be adapted to different models and specifications of impact wrenches. Existing calibration equipment and methods are difficult to meet the needs of rapid verification. In addition, when measuring torque, it is also necessary to deal with the impact. The impact can cause impact damage to the torque sensor. The cumulative damage will cause a large data deviation and affect the verification accuracy. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an impact wrench calibration device. The sensor support forms a sliding pair with the guide rail via a slider, allowing it to move flexibly along the guide rail. This facilitates adjustment of the distance between the sensor support and the adapter sleeve, thus adapting to different torque sensors. The torque sensor is detachably mounted on the sensor support, and its third connector at the measuring end connects to the transmission assembly. This enables torque data acquisition and facilitates sensor replacement and maintenance. For impact wrenches with different torque ranges, there is no need to replace the entire device; only the sensor with the corresponding range needs to be replaced to achieve adaptation, thus expanding the calibration coverage of the device.

[0005] To achieve the above objectives, the following technical solution is adopted:

[0006] An impact wrench calibration device, comprising:

[0007] The base plate and top surface are equipped with bearing seats and guide rails at intervals.

[0008] The adapter sleeve has a one-way bearing and a two-way bearing sequentially fitted on its outer ring and installed in the bearing housing. One end of the adapter sleeve is the first joint of the impact plate, and the other end is provided with a second joint.

[0009] The sensor support forms a sliding pair with the guide rail through a slider. A torque sensor is detachably installed on the sensor support, and the measuring end of the torque sensor is equipped with a third connector.

[0010] The transmission assembly includes an axial flexible coupling, one end of which is connected to a second joint and the other end to a third joint, to transmit torque.

[0011] Furthermore, the base plate is provided with two parallel guide rails, and the sensor support is connected to the two guide rails by two sets of sliders. The sliding direction of the sensor support is parallel to the axis of the adapter sleeve.

[0012] Furthermore, multiple torque sensors are provided, and different torque sensors are installed on the sensor support.

[0013] Furthermore, the inner rings of the one-way bearing and the two-way bearing are fitted with an adapter sleeve, and the outer rings are mounted on the bearing housing.

[0014] Furthermore, the outer ring of the one-way bearing is provided with a locking groove, and the bearing housing is provided with a threaded hole that communicates with the locking groove. The threaded hole is fitted with a locking bolt, which can push the locking ball part into the locking groove to lock the outer ring of the one-way bearing, or cause the locking ball to retract from the locking groove to release the locking of the outer ring of the one-way bearing.

[0015] Furthermore, a locking component is installed on the sensor support, which works with the guide rail to maintain the relative position of the sensor support and the guide rail, or to allow the sensor support to slide and adjust along the guide rail.

[0016] Furthermore, the axial elastic coupling includes a first sleeve, a second sleeve, and a drive pin. One end of the first sleeve is connected to the second connector, and the other end is slidably fitted with the drive pin. One end of the second sleeve is slidably fitted with the drive pin, and the other end is connected to the third connector. An elastic element that can elastically expand and contract along the axial direction is abutted between the first sleeve and the second sleeve.

[0017] Furthermore, the transmission pin is rotatably connected to the first sleeve and the second sleeve, and is slidably fitted along the axial direction.

[0018] Furthermore, the elastic element includes multiple disc springs, which are sleeved outside the transmission pin to apply axial elastic force.

[0019] Furthermore, the base plate has through holes for use with fasteners to fix the base plate.

[0020] Compared with the prior art, the advantages and positive effects of this utility model are:

[0021] To address the current issue of poor compatibility in impact wrench calibration devices, the sensor support, through a slider and guide rail mechanism, forms a sliding pair that allows for flexible movement along the guide rail. This facilitates adjustment of the distance between the sensor support and the adapter sleeve, enabling compatibility with different torque sensors. The torque sensor is detachably mounted on the sensor support, with its third connector at the measuring end interfacing with the transmission assembly. This not only enables torque data acquisition but also facilitates sensor replacement and maintenance. For impact wrenches with different torque ranges, only the sensor with the corresponding range needs to be replaced, without replacing the entire device. This expands the calibration coverage of the device and solves the maintenance difficulties associated with fixed installations. As a flexible buffer bridge for torque transmission, the axial elastic coupling connects to the second connector of the adapter sleeve and the third connector of the torque sensor at both ends. The axial elasticity of the coupling absorbs impact loads while ensuring stable torque transmission, balancing buffer protection and data accuracy.

[0022] The inner ring of the one-way bearing and the outer ring of the adapter sleeve are tightly fitted together. The outer ring is fixedly installed in the bearing housing to ensure the coaxiality of the bearing, the adapter sleeve, and the bearing housing, and to avoid radial runout caused by installation clearance, thus providing a stable rotational reference for torque transmission. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0024] Figure 1 This is a schematic diagram of the impact wrench calibration device in an embodiment of this utility model.

[0025] In the diagram, 1 is the base; 2 is the bearing housing; 3 is the threaded hole; 4 is the one-way bearing; 5 is the first sleeve; 6 is the elastic element; 7 is the second sleeve; 8 is the torque sensor; 9 is the sensor support; 10 is the slider; and 11 is the guide rail. Detailed Implementation

[0026] In a typical embodiment of this utility model, such as Figure 1 As shown, an impact wrench calibration device is proposed.

[0027] In impact wrench calibration equipment, the torque sensor 8 is usually fixedly installed. When the sensor malfunctions or needs to be replaced with a sensor of a different range to adapt to impact wrenches with different torque ranges, the disassembly and installation process is complex. Impact wrenches generate instantaneous impact torque during operation. Existing calibration equipment lacks a targeted buffer structure, and the impact load is directly transmitted to the torque sensor 8, leading to cumulative damage. Accumulated damage causes data drift, resulting in torque measurement deviations and severely affecting calibration accuracy. Therefore, this embodiment provides an impact wrench calibration device equipped with a detachable torque sensor 8. For impact wrenches with different torque ranges, it is not necessary to replace the entire device; only the sensor with the corresponding range needs to be replaced to achieve adaptation, expanding the calibration coverage of the device. Simultaneously, an axial flexible coupling is configured to absorb axial impact during torque transmission, reducing impact damage to the torque sensor 8, thereby improving its service life and ensuring detection accuracy.

[0028] like Figure 1 As shown, the impact wrench calibration device mainly includes a base plate, an adapter sleeve, a sensor support 9, and a transmission assembly. The adapter sleeve is mounted on the base plate via a bearing and a bearing seat 2. The sensor support is mounted on the base plate via a guide rail 11 and a slider 10. Torque is transmitted between the adapter sleeve and the torque sensor 8 on the sensor support through the transmission assembly.

[0029] The base plate serves as the fundamental load-bearing structure of the device, with bearing seats 2 and guide rails 11 spaced apart on its top surface. The bearing seats 2 provide a stable mounting reference for the adapter sleeve, ensuring coaxiality during the rotation of the adapter sleeve; the guide rails 11 provide guidance for the movement of the sensor support 9, which is the basis for realizing the adaptability and adjustment flexibility of the device.

[0030] The adapter sleeve plays a crucial role in docking the impact wrench and initially transmitting torque. A one-way bearing 4 and a double-way bearing are sequentially fitted onto the outer ring of the adapter sleeve and mounted in the bearing housing 2. The one-way bearing 4 limits torque interference when the impact wrench rotates in the opposite direction, allowing for torque accumulation and preventing reverse loads from affecting measurements. The double-way bearing counteracts radial runout, ensuring stable rotation of the adapter sleeve under impact loads. The first connector at one end of the adapter sleeve is used to dock the impact wrench. This first connector uses a square hole with a standard square head, and can also be configured with various adapters to adapt to different specifications. The second connector at the other end connects to the transmission assembly, forming the first link in torque transmission.

[0031] The sensor support 9 forms a sliding pair with the guide rail 11 through the slider 10, which can move flexibly along the guide rail 11. This facilitates the adjustment of the distance between the sensor support 9 and the adapter sleeve, adapting to transmission components of different lengths, and also adapting to torque sensors 8 of different lengths. The torque sensor 8 is detachably installed on the sensor support 9, and its third connector at the measuring end connects to the transmission component, which not only realizes torque data acquisition, but also facilitates the replacement and maintenance of the sensor, solving the maintenance problems caused by fixed installation.

[0032] The transmission assembly employs an axially flexible coupling, which serves as a flexible buffer bridge for torque transmission. Both ends of the axially flexible coupling are respectively connected to the second joint of the adapter sleeve and the third joint of the torque sensor 8. Its axial elasticity absorbs impact loads while ensuring stable torque transmission, balancing buffer protection and data accuracy.

[0033] Understandably, the first connector of the adapter sleeve can use a square hole that fits a standard square head. For impact wrenches of different models and specifications, most have the same standard square head, so there is no need to adjust the overall structure of the device. At the same time, the sensor support 9 can move along the guide rail 11 through the sliding pair, and the distance between it and the adapter sleeve can be flexibly adjusted. When using different torque sensors 8 and transmission components, the axial length of the torque sensor 8 or transmission component is different. Therefore, by adjusting the position of the sensor support 9, it is possible to adapt to torque sensors 8 or transmission components of different lengths, avoiding adaptation difficulties caused by size mismatch.

[0034] In this embodiment, during the calibration process, after the impact wrench is started, the output torque is transmitted to the adapter sleeve through the first connector, and then transmitted to the torque sensor 8 through the axial elastic coupling. The sensor directly collects the torque data, which simplifies the calibration steps and realizes a rapid calibration process of docking-start-measurement, meeting the efficiency requirements of standard calibration scenarios.

[0035] When the impact wrench outputs instantaneous impact torque, the torque first enters the adapter sleeve. The double-direction bearing counteracts the runout caused by the radial impact, and the one-way bearing 4 limits the interference of reverse torque, thus initially stabilizing the torque transmission path. Subsequently, the torque is transmitted to the axial elastic coupling, whose elastic structure undergoes slight deformation in the axial direction, absorbing the peak energy of the impact load and converting the rigid impact into a flexible transmission, thus avoiding the axial impact from directly acting on the torque sensor 8.

[0036] Flexible couplings absorb shocks while maintaining the continuity and stability of torque transmission, avoiding interruptions or fluctuations in torque transmission caused by shocks.

[0037] The torque sensor 8 is detachably mounted on the sensor support 9. When the sensor malfunctions, requires calibration, or needs to be replaced with a sensor of a different range to adapt to impact plates with different torque ranges, only the connection structure between the sensor and the support needs to be disassembled for quick sensor replacement. This eliminates the need to disassemble other components, significantly reducing maintenance time and further meeting the flexible requirements of rapid calibration scenarios. The impact absorption function of the axial flexible coupling reduces the impact load on the sensor, minimizing cumulative damage and extending sensor lifespan. Simultaneously, the stable torque transmission path and reverse interference limitation significantly reduce torque measurement deviation, ensuring calibration accuracy meets standard requirements. The combination of the double-direction bearing and the one-way bearing 4 ensures stable rotation of the adapter sleeve, while the axial flexible coupling compensates for installation errors and impact loads.

[0038] like Figure 1 As shown, the base plate has two parallel guide rails 11. The sensor support 9 is connected to the guide rails 11 by two sets of sliders 10, and the sliding direction is parallel to the axis of the adapter sleeve. In this embodiment, the guide rails 11 can have a dovetail cross-section, and the sliders 10 are provided with dovetail grooves adapted to the guide rails 11.

[0039] Compared to the single guide rail 11, the two-point support structure of the double guide rail 11 and the double slider 10 can limit the lateral displacement of the sensor support 9, ensuring that its sliding trajectory is always consistent with the axis of the adapter sleeve, avoiding misalignment between the axial elastic coupling and the joint due to sliding displacement, and providing guidance accuracy guarantee for stable torque transmission.

[0040] Multiple torque sensors 8 with different ranges are configured and can be replaced and installed on the sensor support 9 as needed. For impact wrenches with different torque ranges (such as low-torque household wrenches and high-torque industrial wrenches), there is no need to replace the entire device. Only the corresponding range sensor needs to be replaced to complete the adaptation, which expands the calibration coverage of the device and further strengthens the core advantage of "the same device can adapt to multiple scenarios".

[0041] The one-way bearing 4 fits tightly with the inner ring of the double-direction bearing via an adapter sleeve, which is fixedly mounted on the bearing housing 2. This ensures the coaxiality of the bearing, adapter sleeve, and bearing housing 2, preventing radial runout caused by installation clearances and providing a stable rotational reference for torque transmission.

[0042] The outer ring of the one-way bearing 4 has a locking groove, and the bearing housing 2 has a threaded hole 3 with a locking bolt. The threaded hole 3 engages with the locking bolt, which can push the locking ball into the locking groove to lock the outer ring of the one-way bearing 4, or remove the locking ball from the locking groove to release the lock on the outer ring of the one-way bearing 4. When performing torque testing on the impact wrench, the torque of each tightening cycle can be accumulated to prevent the adapter sleeve from reversing. After the testing is completed, the locking ball is removed, and the position of the one-way bearing 4 can be adjusted to reset the adapter sleeve, ready for the next testing.

[0043] A locking device is installed on the sensor support 9. The locking device can be abutted or released against the guide rail 11 by means of locking bolts, handle-type locks, etc. After the sensor support 9 is adjusted to the appropriate position, its relative position with the guide rail 11 is fixed by the locking device to prevent the support from shifting due to impact and vibration during the calibration process, and to ensure the docking stability of the torque sensor 8 and the axial flexible coupling. When adjusting the position, the locking device is loosened to maintain the flexibility of sliding.

[0044] The axial flexible coupling includes a first sleeve 5, a second sleeve 7, and a drive pin. One end of the first sleeve 5 is connected to a second connector, and the other end is slidably fitted with the drive pin. One end of the second sleeve 7 is slidably fitted with the drive pin, and the other end is connected to a third connector. An elastic element 6 that expands and contracts axially is abutted between the first sleeve 5 and the second sleeve 7.

[0045] The transmission pin enables torque transmission between the two sleeves, achieving synchronous rotation while allowing the two sleeves to slide relative to each other along the axial direction. The disc spring provides axial elastic force. When impact torque is applied, the two sleeves compress the disc spring to absorb the impact energy, converting the instantaneous impact into the elastic deformation of the disc spring, thus preventing rigid impact from being transmitted to the sensor. Furthermore, the multi-plate structure of the disc spring can adjust the elastic coefficient by stacking the number of plates, adapting to plates with different impact intensities.

[0046] The base plate has through holes for fasteners such as bolts and expansion bolts. These fasteners secure the base plate to the ground or workbench, preventing the entire device from shifting due to impact or vibration during calibration. This provides a stable installation foundation for the entire system and avoids measurement errors caused by device shaking.

[0047] The dual guide rails 11 are parallel and aligned with the axis of the adapter sleeve. The tight fit between the dual sliders 10 and the guide rails 11 restricts the lateral freedom of the sensor support 9, ensuring that the third connector of the torque sensor 8 is always coaxial with the second sleeve 7 of the axial elastic coupling during adjustment. This avoids torque transmission loss or connector wear caused by misalignment and maintains high-precision alignment when adapting to wrenches of different lengths. When calibrating a small-torque impact wrench, a small-range sensor is installed; when calibrating a large-torque wrench, the original sensor is removed and a large-range sensor is installed. The support position is fixed with the locking device. No other structural adjustments are required, allowing for quick range switching and covering a wider range of calibration needs.

[0048] When the impact wrench outputs instantaneous impact torque, the torque is transmitted to the first sleeve 5 via the adapter sleeve. The first sleeve 5 moves along the transmission pin to the second sleeve 7, compressing the disc spring. The elastic force of the disc spring offsets part of the impact energy. At the same time, the transmission pin drives the second sleeve 7 to rotate synchronously, transmitting the buffered and stable torque to the sensor, preventing the impact peak from directly acting on the sensor. After the impact ends, the disc spring resets and pushes the two sleeves back to their original positions, ensuring continuous subsequent torque transmission.

[0049] The disc spring-type axial flexible coupling can adjust its elastic coefficient according to the impact intensity, achieving precise buffering for wrenches with different impact levels. This further reduces the impact load on the sensor and extends its lifespan by over 30%. The replaceable multi-range sensor design allows the device to calibrate torques from 50 N•m to 5000 N•m, covering various impact wrenches for household and industrial use, significantly enhancing its versatility. A fixed base plate and locked support prevent device displacement, reducing operational risks. Simultaneously, all adjustment mechanisms (locking parts, locking bolts) are easy to operate and can be completed without specialized tools, further improving calibration efficiency.

[0050] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An impact wrench calibration apparatus, characterized by, include: The base plate and top surface are equipped with bearing seats and guide rails at intervals. The adapter sleeve has a one-way bearing and a two-way bearing sequentially fitted on its outer ring and installed in the bearing housing. One end of the adapter sleeve is the first joint of the impact plate, and the other end is provided with a second joint. The sensor support forms a sliding pair with the guide rail through a slider. A torque sensor is installed on the sensor support, and the measuring end of the torque sensor is equipped with a third connector. The transmission assembly includes an axial flexible coupling, one end of which is connected to a second joint and the other end to a third joint, to transmit torque.

2. The impact wrench calibration apparatus of claim 1, wherein, The base plate is provided with two parallel guide rails. The sensor support is connected to the two guide rails by two sets of sliders. The sliding direction of the sensor support is parallel to the axis of the adapter sleeve.

3. An impact wrench calibration apparatus as claimed in claim 1 or 2, wherein, Multiple torque sensors are provided, and different torque sensors are installed on the sensor support.

4. The impact wrench calibration apparatus of claim 1, wherein, The inner rings of the one-way and two-way bearings are fitted with adapter sleeves, and the outer rings are mounted on the bearing housings.

5. The impact wrench calibration apparatus of claim 4, wherein, The outer ring of the one-way bearing has a locking groove, and the bearing housing has a threaded hole that connects to the locking groove. The threaded hole is fitted with a locking bolt. The locking bolt can push the locking ball part into the locking groove to lock the outer ring of the one-way bearing, or cause the locking ball to retract from the locking groove to release the locking of the outer ring of the one-way bearing.

6. The impact wrench calibration apparatus of claim 1, wherein, The sensor support is equipped with a locking device, which works with the guide rail to maintain the relative position of the sensor support and the guide rail, or to allow the sensor support to slide and adjust along the guide rail.

7. The impact wrench calibration apparatus of claim 1, wherein, The axial elastic coupling includes a first sleeve, a second sleeve, and a drive pin. One end of the first sleeve is connected to the second connector, and the other end is slidably fitted with the drive pin. One end of the second sleeve is slidably fitted with the drive pin, and the other end is connected to the third connector. An elastic element that expands and contracts axially is abutted between the first sleeve and the second sleeve.

8. The impact wrench calibration apparatus of claim 7, wherein, The transmission pin is rotatably connected to the first sleeve and the second sleeve, and slides along the axial direction.

9. An impact wrench calibration apparatus as claimed in claim 7 or 8, wherein, The elastic element includes multiple disc springs, which are sleeved outside the transmission pin to apply axial elastic force.

10. The impact wrench calibration apparatus of claim 1, wherein, The base plate has through holes for fasteners to be used to fix the base plate.

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