Excitation Equipment Applicable to Modal and Vibration Transfer Function Tests

Abstract

The present invention discloses an excitation device applicable to modal and vibration transfer function tests, which includes an excitation head having the functions of controlling the excitation force, marking the excitation point, and recording the excitation angle; a telescopic support arm for installing the excitation head and having the function of greatly adjusting the position of the excitation head; and a base for installing the telescopic support arm. The advantages of the present invention are reflected in the following aspects: 1. It realizes automated excitation measurement, avoiding the problems of secondary knocking caused by manual excitation and the inconsistencies in excitation force, excitation angle, and excitation position during the test; 2. The excitation device designed in the present invention can record the magnitude of the excitation force, excitation angle, and excitation position during the test through the process data recording function, achieving the consistency of excitation conditions in comparative tests; 3. It realizes the excitation force adjustment function.

Description

Technical Field

[0001] The present invention relates to vibration testing technology, and particularly to an excitation device suitable for modal and vibration transfer function tests. Background Art

[0002] Modal testing, also known as experimental modal analysis, is a vibration test conducted to determine the modal parameters of a linear vibration system.

[0003] Vibration transfer function testing refers to a test for verifying the relationship between the output (vibration) and input (vibration, noise) of a system at a given frequency.

[0004] During modal and vibration transfer function tests, the impact hammer and shaker are one of the key pieces of equipment in the test. An impulse excitation can be generated on the structure of the object under test through the impact hammer or shaker, and then data is collected at the response position through vibration or noise sensors. In this way, the frequency response function (transfer function test) is obtained, and a series of vibration frequency response data is subjected to modal identification to obtain modal data (modal test).

[0005] In the traditional test process, the impact hammer and shaker are one of the most common tools, and both have their own advantages and disadvantages: The impact hammer is convenient and fast, but it has relatively high requirements for the test personnel. It is required that the test personnel hold the hammer firmly and steadily (to prevent double impacts), and at the same time, the impact force, impact angle, and impact position during one impact process (generally, an excitation point needs to be struck five times) should be kept basically the same. Only in this way can an ideal frequency response function be obtained, and it is difficult for untrained test personnel to master the above capabilities in a short time. When using the shaker, the sensor needs to be pasted on the surface of the object under test, and then the sensor is excited. The shaker can stably output excitation during the test, but the weight of the sensor itself and the pasting quality (such as the thickness of the glue, the smoothness of the paste, etc.) also have a certain impact on the test results. Since there are no measurement and recording requirements for the magnitude, excitation angle, and excitation position of the excitation force during the test in the traditional modal and transfer function test methods, this results in inconsistent test data between two consecutive tests or tests conducted by different test personnel, and thus data analogical analysis cannot be carried out.

[0006] Chinese invention patent (authorization announcement number: CN108132130B) discloses a full-automatic modal impact hammer for test modal testing. The inner core of the modal impact hammer includes an inner shell, and a force measuring mechanism, a distance measuring mechanism, and a force adjusting mechanism installed in the inner shell. The inner shell is integrally embedded in the outer shell. A handle is fixedly installed below the outside of the outer shell. A wrench mechanism is installed between the handle and the force adjusting mechanism. The wrench mechanism passes through the outer shell and the inner shell and is clamped with the force adjusting mechanism. When in use, according to the actual situation and the object to be measured, the applied force size, the knocking point, and the distance between the thimble and the counterweight are adjusted; the pulse knocking force is adjusted; the trigger structure is pulled, and the inner core pops out; the trigger is released, and the inner core retracts; the excitation signal is viewed through a computer. This modal impact hammer claims to solve the problems of high requirements for the user to hold the hammer steadily, accurately hit the point, be prone to double hitting, and prevent the impact point from slipping on the test piece when using the modal impact hammer, greatly reducing the difficulty of using the modal impact hammer, making it easy to master the operation key points, and improving the test accuracy and test efficiency of modal parameters. However, there are still defects that the knocking position and knocking angle cannot be guaranteed to be consistent during the test in manual operation, and there is no record and preservation of the excitation force, knocking position, and knocking angle during the test process, and accurate data cannot be obtained during the repeated comparison test process.

[0007] Chinese invention patent (authorization announcement number: CN204043882U) discloses a workbench type automatic impact hammer device, which mainly consists of components such as a motor, a base, a vertical seat, a positioning spring, a positioning gear sleeve rocker arm, an optical encoder, and a force hammer clamping movable force hammer, etc.; it claims that it can save the cost of manufacturing an additional hammer head, and at the same time ensure that the magnitude, direction of the excitation force have good consistency, repeatability, and adjustability. However, this device is affected by the fixed position and knocking angle, and it is difficult to replace the knocking point of the object to be measured. Therefore, this device is only suitable for some bench tests. Summary of the Invention

[0008] The purpose of the present invention is to provide an excitation device suitable for modal and vibration transfer function tests in view of the defects of the above-mentioned existing technologies. While ensuring and recording the excitation force, excitation angle, and excitation position during the test process, this device can also move and meet the requirements of most excitation positions.

[0009] To achieve the above purpose, the present invention can adopt the following technical solutions:

[0010] The excitation device suitable for modal and vibration transfer function tests according to the present invention includes

[0011] An excitation head, which has the functions of controlling the excitation force, marking the excitation point, and recording the excitation angle;

[0012] A telescopic support arm, which is used to install the excitation head and has the function of realizing a large-scale adjustment of the position of the excitation head;

[0013] A base, which is used to install the telescopic support arm.

[0014] The excitation head of the present invention comprises a shell, a hammer body composed of a stud for mounting a hammer head, a force sensor and a counterweight block is placed in the shell, the stud extends from the front end of the shell, and a tension spring is fixedly connected between the shell and the counterweight block; the front end of a rack horizontally arranged at the rear of the counterweight block is fixedly connected to the counterweight block, and a gear meshing with the rack is connected to a motor located in the shell through a transmission member;

[0015] An infrared calibrator is arranged on the front end surface of the shell, and an angle sensor is arranged on the side wall of the shell.

[0016] In order to prevent the double-click problem during the test, a blind hole is opened on the inner surface of the side wall of the shell, and an electromagnetic spring button is installed in the blind hole. A locking hole matching the electromagnetic spring button is provided on the hammer body corresponding to the position of the electromagnetic spring button.

[0017] To facilitate adjustment of the position of the excitation head, the telescopic support arm of the present invention is composed of a primary telescopic rod and a secondary telescopic rod hinged together as one, the end of the primary telescopic rod is hinged to the connecting ear of the excitation head through a connecting shaft, and the lower end of the secondary telescopic rod is installed on the base; an angle adjustment component is arranged between the primary telescopic rod and the secondary telescopic rod.

[0018] The first-stage telescopic rod and the second-stage telescopic rod are both composed of a telescopic arm and a telescopic sleeve arm mounted thereon; the angle adjustment assembly includes a slide groove arranged on the telescopic arm of the second-stage telescopic rod and an adjustment slide sliding along the slide groove, and the other end of the slide rod hinged to the adjustment slide is hinged to the connecting ear on the telescopic sleeve arm of the first-stage telescopic rod.

[0019] The telescopic sleeve arms of the primary telescopic rod and the secondary telescopic rod are both provided with positioning bolts.

[0020] The connecting shaft is a locking screw.

[0021] A fastening screw is arranged on the adjusting slide seat.

[0022] It also includes a controller, which is used to receive data information from the angle sensor and the force sensor, and send control information to the motor.

[0023] The advantages of the present invention are embodied in the following points:

[0024] 1. It realizes automated excitation measurement, avoiding the secondary knocking problem caused by artificial excitation and the inconsistency of excitation strength, excitation angle and excitation position during the test;

[0025] 2. The excitation device designed by the present invention can record the magnitude of the excitation force, the excitation angle, and the excitation position during the test through the process data recording function, achieving the consistency of excitation conditions in the comparative test;

[0026] 3. The excitation force adjustment function is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the present invention.

[0028] Figure 2 is Figure 1 the structural diagram of the excitation head in

[0029] Figure 3 is Figure 2 the sectional view of

[0030] Figure 4 is Figure 3 the A-A view of

[0031] Figure 5 、 Figure 6 is Figure 1 the structural diagram of the telescopic support arm in

[0032] Figure 7 is the usage state diagram of the present invention.

[0033] Figure 8 is the circuit principle block diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be described in more detail below with reference to the drawings for the understanding of those skilled in the art.

[0035] Those skilled in the art should understand that this embodiment is only used to explain the technical principle of the present application and is not used to limit the protection scope of the present application. For example, although the components in the drawings are drawn according to a certain proportional relationship, this proportional relationship is not fixed. Those skilled in the art can adjust it according to needs to adapt to specific application scenarios, and the adjusted technical solution will still fall within the protection scope of the present application.

[0036] It should be noted that in the description of the present application, the terms indicating directions or position relationships such as "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or position relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application.

[0037] In addition, it should be noted that in the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] like Figure 1 As shown, the excitation device suitable for modal and vibration transfer function tests described in the present invention includes an excitation head 1, which has the functions of controlling the exciting force, marking the excitation point and recording the excitation angle; a telescopic support arm 2, which is used to install the excitation head 1 and has the function of realizing a large-scale adjustment of the position of the excitation head; and a base 3, which is used to install the telescopic support arm 2.

[0039] Specifically, the excitation head structure of the present invention is as follows Figure 2 , Figure 3 , Figure 4 As shown, it includes a shell 101 (blind hole structure), an infrared calibrator 102 is arranged on the front end surface of the shell, and an angle sensor 103 is arranged on the side wall of the shell.

[0040] like Figure 3 As shown, a hammer body consisting of a stud 104 for mounting a hammer head (the hammer head is not shown in the figure), a force sensor 105 and a counterweight 106 is placed in a shell 101, and the stud 104 extends out from the front end opening of the shell, and two tension springs 107 are symmetrically fixed between the shell 101 and the counterweight 106; the front end of a rack 108 horizontally placed at the rear of the counterweight 106 is fixedly connected to the counterweight 106, and a gear 109 meshing with the rack 108 is transmission-connected to the working shaft of a motor 110 located in the shell through a transmission member.

[0041] During operation, the controller controls the motor 110 to be powered on, and the motor 110 works, transmitting the torque to the rack 108 through the transmission parts and the gear 109, and the rack 108 drives the hammer composed of the stud 104, the force sensor 105 and the counterweight 106 to move backward, thereby pulling the two tension springs 107 to extend. When the controller controls the motor 110 to be powered off, the two tension springs 107 drive the hammer to be ejected forward to realize the excitation function.

[0042] In order to prevent the double-click problem during the test, the present invention provides a blind hole on the inner surface of the side wall of the housing 101, such as Figure 4As shown in the figure, an electromagnetic snap button 111 (such as a common solenoid valve with a valve core) is installed therein, and a locking hole 112 matching the electromagnetic snap button 111 is provided on the hammer body corresponding to the position of the electromagnetic snap button 111; in actual production, the electromagnetic snap button 111 and the locking hole 112 can be designed such that one side is an inclined surface and the other side is a vertical surface.

[0043] During the energization of the motor, the electromagnetic snap button 111 is attracted and closed with the energization, and the hammer body moves forward. When the locking hole 112 cooperates with the electromagnetic snap button 111, the electromagnetic snap button 111 can be compressed, and the electromagnetic snap button 111 allows the hammer body to pass through. After the motor is powered off, the electromagnetic snap button 111 pops forward with the power-off. When the locking hole 112 cooperates with the electromagnetic snap button 111, the electromagnetic snap button 111 is inserted into the locking hole 112 to prevent the hammer body from passing through. This structure can effectively prevent the problem of double-clicking of the hammer body.

[0044] To facilitate the adjustment of the position of the excitation head, the telescopic support arm 2 of the present invention is composed of a first-stage telescopic rod and a second-stage telescopic rod that are hinged together. Figure 5 It is the structure of the first-stage telescopic rod. Figure 6 It is the structure of the second-stage telescopic rod; the upper end of the first-stage telescopic rod is hinged to the connecting ear 5 of the excitation head 1 through the connecting shaft 4. To facilitate the positioning after the position is adjusted appropriately, the connecting shaft 4 can adopt a locking screw and is fastened with a nut after the adjustment is in place; the first-stage telescopic rod is composed of an upper telescopic arm 201 and an upper telescopic sleeve arm 202 sleeved outside it, and an upper positioning bolt 203 is provided on the upper telescopic sleeve arm 202; the lower end of the second-stage telescopic rod is installed on the base 3. The second-stage telescopic rod is composed of a lower telescopic arm 204 and a lower telescopic sleeve arm 205 sleeved outside it. The upper end of the lower telescopic arm 204 is connected to the upper telescopic sleeve arm 202 of the first-stage telescopic rod through a hinge shaft 206 (with a locking function, which can be realized by a bolt cooperating with a nut). A lower positioning bolt 207 is provided on the lower telescopic sleeve arm 205; an angle adjustment component is also provided between the first-stage telescopic rod and the second-stage telescopic rod: including a chute 208 opened on the lower telescopic arm 204 of the second-stage telescopic rod and an adjustment sliding seat 209 sliding along the chute. The upper end of a sliding rod 210 whose lower end is hinged to the adjustment sliding seat 209 is hinged to the connecting ear 211 on the telescopic sleeve arm of the first-stage telescopic rod, as Figure 7 shown in the figure, to realize the free adjustment of the excitation position and meet the excitation requirements; similarly, to achieve accurate positioning, a fastening screw 212 is provided on the adjustment sliding seat 209.

[0045] The present invention can realize functions such as excitation function, anti-double-click function, position adjustment function, excitation force adjustment function, and process data recording function:

[0046] 1. Position adjustment function:

[0047] The excitation head 1 can rotate and lock with the upper telescopic arm 201 of the first-stage telescopic rod through the connecting shaft 4. The first-stage telescopic rod and the second-stage telescopic rod can rotate and lock at 90° through the hinge shaft 206. During the selection process, the sliding rod 210 cooperates with the adjustment sliding seat 209 (after sliding to the appropriate position, the adjustment sliding seat 209 can be locked and positioned through the fastening screw 212), providing stable support for the hammer head to work; the first-stage telescopic rod and the second-stage telescopic rod can freely extend and lock themselves. Through the above structure, the excitation device of the present invention can freely adjust the excitation position to meet the excitation requirements.

[0048] 2. Excitation function:

[0049] When the position is adjusted appropriately, the controller controls the motor 110 to work. The torque is transmitted to the rack 108 through the transmission parts and the gear 109, and the rack 108 drives the hammer body composed of the stud 104, the force sensor 105 and the counterweight 106 to move backward, thereby pulling the two tension springs 107 to elongate. When the controller controls the motor 110 to cut off the power, the two tension springs 107 drive the hammer body to move forward and excite, realizing the excitation function.

[0050] 3. Anti-double-click function:

[0051] During the power-on process of the motor, the effective cooperation of the electromagnetic snap button 111 and the locking hole 112 is utilized: the electromagnetic snap button 111 is attracted and closed with the power-on, and the hammer body moves forward. When the locking hole 112 cooperates with the electromagnetic snap button 111, the electromagnetic snap button 111 can be compressed, and the electromagnetic snap button 111 allows the hammer body to pass through. When the motor is powered off, the electromagnetic snap button 111 pops forward with the power-off. When the locking hole 112 cooperates with the electromagnetic snap button 111, the electromagnetic snap button 111 is inserted into the locking hole 112 to prevent the hammer body from passing through, so as to realize only one excitation and effectively prevent the double-click problem of the hammer body.

[0052] 4. Excitation force adjustment function:

[0053] The controller can control the magnitude of the excitation force by controlling the power-on time of the motor 110 (the motor speed remains unchanged), that is, by controlling the stroke of the tension spring 107.

[0054] 5. Process data recording function: As Figure 8 shown, the controller 300 is a PLC integrating a data interface module and a power interface module; as Figure 3 shown, the controller 300 is arranged in the housing 101;

[0055] The data interface module is connected to the host computer through a wire harness, and the power interface module is connected to an external power supply for power supply; the PLC controls the energization time of the motor 110, that is, controls the stroke of the tension spring 107 to control the magnitude of the excitation force; the force sensor 105 is used to record the magnitude of each excitation force and transmit the data to the PLC, and the angle sensor 103 is used to collect the data information of the excitation angle and send it to the PLC; during the excitation process, the infrared calibrator 102 can express the excitation position, and then the experimenter marks it on the object to be measured with a water pen to record the excitation position; the PLC transmits the collected data information to the host computer through the wire harness, realizing the functions of recording the excitation force, excitation angle, and excitation position.

Claims

1. An excitation device suitable for modal and vibration transfer function tests, Features: include The excitation head has the functions of controlling the excitation force, marking the excitation point and recording the excitation angle; The telescopic support arm is used to install the excitation head and has the function of greatly adjusting the position of the excitation head; A base for mounting a telescopic support arm; The excitation head comprises a shell, a hammer body consisting of a stud for mounting a hammer head, a force sensor and a counterweight is placed in the shell, the stud extends from the front end of the shell, and a tension spring is fixedly connected between the shell and the counterweight; the front end of a rack horizontally arranged at the rear of the counterweight is fixedly connected to the counterweight, and a gear meshing with the rack is connected to a motor located in the shell through a transmission member; a blind hole is provided on the inner surface of the side wall of the shell, an electromagnetic spring button is installed therein, and a locking hole matching the electromagnetic spring button is provided on the hammer body corresponding to the position of the electromagnetic spring button; An infrared calibrator is arranged on the front end surface of the shell, and an angle sensor is arranged on the side wall of the shell.

2. The excitation device for modal and vibration transfer function tests according to claim 1, Features: The telescopic support arm consists of a primary telescopic rod and a secondary telescopic rod which are hinged together. The end of the primary telescopic rod is hinged to the connecting ear of the excitation head through a connecting shaft, and the lower end of the secondary telescopic rod is installed on the base; an angle adjustment component is arranged between the primary telescopic rod and the secondary telescopic rod.

3. The excitation device suitable for modal and vibration transfer function testing according to claim 2, Features: The first-stage telescopic rod and the second-stage telescopic rod are both composed of a telescopic arm and a telescopic sleeve arm mounted thereon; the angle adjustment assembly includes a slide groove arranged on the telescopic arm of the second-stage telescopic rod and an adjustment slide sliding along the slide groove, and the other end of the slide rod hinged to the adjustment slide is hinged to the connecting ear on the telescopic sleeve arm of the first-stage telescopic rod.

4. The excitation device for modal and vibration transfer function tests according to claim 3, Features: The telescopic sleeve arms of the primary telescopic rod and the secondary telescopic rod are both provided with positioning bolts.

5. The excitation device suitable for modal and vibration transfer function testing according to claim 2, Features: The connecting shaft is a locking screw.

6. The excitation device suitable for modal and vibration transfer function tests according to claim 3, Features: A fastening screw is arranged on the adjusting slide seat.

7. The excitation device for modal and vibration transfer function tests according to claim 1, Features: It also includes a controller, which is used to receive data information from the angle sensor and the force sensor, and send control information to the motor.

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