Monitoring device for calibrating concentricity of fatigue testing instrument

Abstract

The utility model discloses a monitoring device for calibrating the concentricity of a fatigue testing instrument, and relates to the technical field of fatigue testing, and the monitoring device comprises a calibration shaft, a strain testing piece and a signal acquisition module. The calibration shaft comprises a concentric shaft and a test shaft, in the calibration process, the concentric shaft and the test shaft make contact with each other to cause deformation of a grating of a strain test piece, transverse force and lateral force are collected through a signal collection module according to the change, and collected data are displayed in upper computer software. Whether the two mounting ends are coaxial or not can be visually fed back through data fluctuation conditions of the transverse force and the lateral force.

Description

Technical Field

[0001] This utility model relates to the field of fatigue testing technology, and in particular to a monitoring device for calibrating the concentricity of fatigue testing instruments. Background Technology

[0002] Fatigue testing machines are experimental devices used to conduct fatigue stress loading tests on mechanical parts. Based on their working principles, they can be classified into electro-hydraulic servo fatigue testing machines, hydraulic pulse fatigue testing machines, mechanical fatigue testing machines, and electromagnetic resonance fatigue testing machines, among others. Among these, electro-hydraulic servo fatigue testing machines are widely used and researched in aerospace, automotive, shipbuilding, construction, and machinery fields due to their high output power, wide frequency range, and fast dynamic response. Fatigue testing machines simulate cyclic loads under actual usage conditions, continuously loading and unloading the tested object to evaluate its performance over long-term use.

[0003] Concentricity is the degree of deviation between the axis or centerline of an object or component and its ideal axis or centerline during manufacturing or processing. In practical applications, the level of concentricity directly affects the accuracy, performance, and service life of an object or component.

[0004] The problems with existing fatigue testing instruments' concentricity monitoring devices are: 1. poor accuracy and lack of simplicity and intuitiveness; 2. the testing method using resistance strain gauge load sensors is large in size and expensive. Utility Model Content

[0005] This invention provides a monitoring device for calibrating the concentricity of fatigue testing instruments, thereby solving the problems in the prior art.

[0006] The technical problem solved by this utility model is achieved by the following technical solution:

[0007] A monitoring device for calibrating the concentricity of a fatigue testing instrument includes a calibration shaft, a strain gauge, and a signal acquisition module. The calibration shaft comprises a concentric shaft and a test shaft. One end of the concentric shaft is connected to a first mounting end of the fatigue testing instrument, and the other end of the concentric shaft is provided with a tip for contacting the test shaft. One end of the test shaft is connected to a second mounting end of the fatigue testing instrument, and the other end of the test shaft contacts the tip. The strain gauge is disposed on the outer periphery of the test shaft and is connected to the signal acquisition module, which is used to acquire the physical signals of the strain gauge.

[0008] The beneficial effects of this utility model are:

[0009] The monitoring device of this utility model includes a calibration shaft, a strain gauge, and a signal acquisition module. The calibration shaft includes a concentric shaft and a test shaft, which are used together to calibrate the concentricity of the fatigue testing instrument. The two parts are respectively connected to the two mounting ends of the fatigue testing instrument. The concentric shaft is driven by the fatigue testing instrument to apply force towards the test shaft. The concentric shaft achieves point contact with the test shaft by setting a tip, so as to more accurately sense the force. During the calibration process, the contact between the concentric shaft and the test shaft will cause the grating of the strain gauge to deform. This change will be collected by the signal acquisition module to collect the lateral force and the side force. The collected data is presented in the host computer software. The fluctuation of the lateral force and the side force data can intuitively reflect whether the two mounting ends are coaxial. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the monitoring device in this application;

[0012] Figure 2 yes Figure 1 Isometric sectional view;

[0013] Figure 3 yes Figure 1 Vertical cross-sectional view of the center alignment axis;

[0014] Figure 4 This is a schematic diagram of the annular shell structure in this application;

[0015] Figure 5 This is a partial structural diagram of the signal acquisition module (only a semi-circular shell is shown);

[0016] Figure 6 This is a front view of a fatigue testing instrument in the prior art;

[0017] The annotations in the attached figures are explained as follows:

[0018] 100. Calibration shaft; 110. Concentric shaft; 111. Tip; 120. Test shaft; 121. First disk; 1211. Tapered hole; 122. First cylinder; 123. Second disk; 1231. Positioning step; 124. Second cylinder;

[0019] 200. Strain test specimen;

[0020] 300. Signal acquisition module; 310. Ring-shaped housing; 311. Semi-circular housing; 312. Connecting ear; 313. Locking component; 314. Heat dissipation hole; 320. Acquisition board; 330. Power component; 331. Power display screen; 332. Switch; 333. Charging interface; 334. Battery;

[0021] 400. Fatigue testing instrument; 410. First mounting end; 420. Second mounting end. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0023] like Figure 1 and Figure 2 As shown in the figure, this embodiment discloses a monitoring device for calibrating the concentricity of a fatigue testing instrument. The monitoring device includes a calibration shaft 100, a strain test piece 200, and a signal acquisition module 300, as detailed below:

[0024] like Figure 2 and Figure 3 As shown, the calibration shaft 100 includes a concentric shaft 110 and a test shaft 120. The concentric shaft 110 is cylindrical in shape. The concentric shaft 110 and the test shaft 120 are detachably mounted vertically. The upper end of the concentric shaft 110 is connected to the first mounting end 410 (i.e., the upper clamp) of the fatigue testing instrument 400. The lower end of the concentric shaft 110 has a tapered structure with a tip 111 facing the test shaft 120. The lower end of the test shaft 120 is connected to the fatigue testing instrument 400. The second mounting end 420 of the instrument 400 is connected (i.e., the lower clamp). When the fatigue testing instrument 400 needs to be calibrated, the first mounting end 410 drives the tip 111 of the concentric shaft 110 to abut against the upper end of the test shaft 120, and the physical signals of the test shaft 120 are collected through the strain test piece 200, namely, the transverse force (B1) and the lateral force (B2). By collecting the transverse force and lateral force data, the coaxiality of the fatigue testing instrument 400 can be observed intuitively.

[0025] In some preferred embodiments, the upper end of the concentric shaft 110 is threaded to the first mounting end 410, and the lower end of the test shaft 120 is threaded to the second mounting end 420, making the connection simple and quick.

[0026] In this embodiment, as Figure 6 As shown, the fatigue testing instrument 400 to be tested is the electro-hydraulic servo dynamic and static fatigue testing machine of China Machinery Testing Equipment Co., Ltd.

[0027] like Figure 3As shown, the test shaft 120 includes a first disk 121, a first cylinder 122, a second disk 123, and a second cylinder 124 that are coaxially connected in sequence along the height direction;

[0028] The upper end of the first disk 121 can contact the tip 111 of the concentric shaft 110. In some preferred embodiments, the first disk 121 is provided with a tapered hole 1211. The tapered hole 1211 is coaxial with the first disk 121. The size of the tapered hole 1211 matches the tip 111 of the concentric shaft 110, so that the inner circumferential surface of the tapered hole 1211 can be in close contact with the outer circumferential surface of the tip 111.

[0029] The outer diameter of the first cylinder 122 is smaller than the outer diameter of the second cylinder 124. The strain gauge 200 is fitted onto the outer circumference of the first cylinder 122. In this embodiment, the strain gauge 200 is positioned at the thinnest end of the test shaft 120 (i.e., the first cylinder 122), allowing for precise monitoring of the force transmitted by the concentric shaft 110, thus ensuring the accuracy of the calibration work. In some preferred embodiments, there are at least two strain gauges 200 (preferably two in this embodiment). The two strain gauges 200 are glued to the first cylinder 122 of the test shaft 120 and compacted to ensure linear deformation testing. Various bonding methods, bonding angles, and types of glue can be used to attach the strain gauges. To monitor different strain types, various bridging methods, sizes, and types of strain gauges can be used to monitor lateral and transverse forces during the calibration process.

[0030] like Figure 3 As shown, a positioning step 1231 is provided on the second disk 123. At least part of the signal acquisition module 300 (specifically the annular housing 310) is disposed on the positioning step 1231. The positioning step 1231 provides an installation position for the annular housing 310 of the signal acquisition module 300 and also serves as a positioning function.

[0031] The signal acquisition module 300 includes an annular housing 310, an acquisition plate 320, and a power supply component 330. The annular housing 310 is coaxially sleeved on the first column 122. Along the height direction, the annular housing 310 is located between the first disk 121 and the second disk 123. The two disks close the openings at the top and bottom of the annular housing 310, thus protecting the internal components of the annular housing 310. The inner side of the annular housing 310 rests on the positioning step 1231 to achieve positioning of the annular housing 310. The acquisition plate 320 and the power supply component 330 are both disposed on the annular housing 310. The acquisition plate 320 can be electrically connected to the strain test piece 200 in a one-to-one correspondence. The acquisition plate 320 acquires lateral force and side force data. In some preferred embodiments, the acquisition plate 320 is directly or indirectly connected to a host computer, which can receive the lateral force and side force data and display them in a digital or graphical manner. The power supply component 330 is electrically connected to the acquisition plate 320 and is used to supply power to the acquisition plate 320.

[0032] In some preferred embodiments, such as Figure 4 As shown, the annular housing 310 includes two detachably connected semicircular housings 311. The two semicircular housings 311 can be closed to form a complete circle. The annular housing 310 adopts a detachable structure, which facilitates quick disassembly and assembly and is simple to assemble.

[0033] In this embodiment, two semi-circular shells 311 surround the outer periphery of the first column 122. The second disk 123 is provided with positioning steps 1231 corresponding to the semi-circular shells 311, and the inner sides of the two semi-circular shells 311 are correspondingly positioned on the positioning steps 1231. In some preferred embodiments, the two semi-circular shells 311 are detachably connected in the following ways: Figure 4 As shown, each of the two semi-circular shells 311 has a corresponding connecting ear 312 on its outer periphery. The locking member 313 passes through the connecting ear 312 of the two semi-circular shells 311 and tightens the two connecting ears 312 by screwing the nut of the locking member 313, thereby realizing the connection and fastening of the two semi-circular shells 311.

[0034] In some preferred embodiments, such as Figure 4 As shown, the semi-circular housing 311 is provided with heat dissipation holes 314 to facilitate heat dissipation of the internal components of the semi-circular housing 311.

[0035] like Figure 5As shown, the power component 330 includes a power display screen 331, a switch 332, a charging interface 333, and a battery 334. The power display screen 331 is mounted on a semi-circular housing 311 and is visible on the outside of the annular housing 310, allowing external personnel to easily observe the power status of the battery 334. The switch 332 is mounted on the semi-circular housing 311 and is electrically connected to the acquisition board 320, controlling whether the acquisition board 320 is activated. The charging interface 333 is mounted on the semi-circular housing 311 and is electrically connected to the battery 334, allowing external devices to charge the battery 334. The battery 334 is located inside the semi-circular housing 311 and is electrically connected to the acquisition board 320, providing power to the acquisition board 320.

[0036] In this embodiment, the semi-circular shell 311 encloses components such as the acquisition board 320 and the battery 334, providing protection.

[0037] During the calibration process, the fatigue testing instrument 400 to be calibrated drives the concentric shaft 110 to move downward. The tip 111 of the concentric shaft 110 comes into contact with the test shaft 120, which will cause the grating of the strain test piece 200 to deform. This change will be collected by the acquisition plate 320 to collect the transverse force (B1) and the lateral force (B2).

[0038] The collected data can be sent to a PC or PLC. In this embodiment, the collected data is mainly presented in the host computer software. When the concentricity is low, the host computer software will detect obvious signal abrupt changes (increase or decrease) in B1 or B2, that is, the upper and lower mounting ends are not in the same axial position. It is necessary to adjust the lateral position of the upper and lower mounting ends to optimize the concentricity. When the host computer software detects that there is no obvious micro-strain in B1 and B2, it means that the fatigue testing instrument 400 is highly concentric. At this time, the state of the fatigue testing instrument 400 can ensure the accuracy and validity of the fatigue test results.

[0039] The monitoring device in this embodiment can achieve high-frequency stable acquisition of lateral and transverse forces (acquisition frequency up to 10240Hz), thereby realizing digital and precise optimization of the concentricity of the equipment, improving the accuracy and reliability of fatigue testing. The overall device is simple, easy to install, and the testing process is convenient.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A monitoring device for calibrating the concentricity of a fatigue testing instrument, characterized in that, The calibration shaft (100), the strain testing piece (200) and the signal acquisition module (300) are included. The calibration shaft (100) includes a concentric shaft (110) and a testing shaft (120), one end of the concentric shaft (110) is connected with a first mounting end (410) of a fatigue testing instrument (400), the other end of the concentric shaft (110) is provided with a sharp end (111) for contacting the testing shaft (120); one end of the testing shaft (120) is connected with a second mounting end (420) of the fatigue testing instrument (400), the other end of the testing shaft (120) contacts the sharp end (111). The strain testing piece (200) is arranged on the outer periphery of the testing shaft (120), the strain testing piece (200) is connected with the signal acquisition module (300), and the signal acquisition module (300) is used for acquiring a physical signal of the strain testing piece (200).

2. The monitoring device of claim 1, wherein, One end of the concentric shaft (110) is threadedly connected with the first mounting end (410); one end of the testing shaft (120) is threadedly connected with the second mounting end (420).

3. The monitoring device of claim 1, wherein, The testing shaft (120) includes a first disc (121), a first cylinder (122), a second disc (123) and a second cylinder (124) which are coaxially connected in sequence; the first disc (121) can contact the sharp end (111), the outer diameter of the first cylinder (122) is smaller than that of the second cylinder (124), and at least two strain testing pieces (200) are arranged on the outer periphery of the first cylinder (122) in a close manner; the second cylinder (124) is connected with the second mounting end (420).

4. The monitoring device of claim 3, wherein, A tapered hole (1211) is arranged on the first disc (121), and an inner periphery surface of the tapered hole (1211) can contact an outer periphery surface of the sharp end (111).

5. The monitoring device of claim 3, wherein, A positioning step (1231) is arranged on the second disc (123), and at least part of the signal acquisition module (300) is arranged on the positioning step (1231).

6. The monitoring device of claim 5, wherein, The signal acquisition module (300) includes a ring-shaped shell (310), an acquisition plate (320) and an electric quantity assembly (330); the ring-shaped shell (310) is sleeved on the first cylinder (122) and located between the first disc (121) and the second disc (123), the ring-shaped shell (310) is arranged on the positioning step (1231); the acquisition plate (320) and the electric quantity assembly (330) are both arranged in the ring-shaped shell (310), the acquisition plate (320) is electrically connected with the strain testing piece (200), and the electric quantity assembly (330) is electrically connected with the acquisition plate (320).

7. The monitoring device of claim 6, wherein, The ring-shaped shell (310) includes two half circular shells (311) which are detachably connected, the two half circular shells (311) are arranged on the outer periphery of the first cylinder (122) and correspondingly arranged on the positioning step (1231).

8. The monitoring device of claim 7, wherein, The outer periphery of each of the two half-circular shells (311) is provided with a corresponding connecting lug (312), the connecting lugs (312) of the two half-circular shells (311) are connected through a locking member (313) to realize detachable connection of the two half-circular shells (311).

9. The monitoring device of claim 7, wherein, The half-circular shell (311) is provided with a heat dissipation hole (314).

10. The monitoring device according to any one of claims 6 to 9, characterized in that The power component (330) comprises a power display screen (331), a switch (332), a charging interface (333) and a battery (334), which are all arranged on the annular shell (310); the power display screen (331) is exposed to the outside of the annular shell (310), the switch (332) is connected with the acquisition board (320), the charging interface (333) is connected with the battery (334), and the battery (334) is connected with the acquisition board (320).

Images