Dynamic characteristics measuring device

Abstract

To accurately measure horizontal motion characteristics of a work-piece when a vertical load is applied to the work-piece.SOLUTION: A dynamic characteristic measurement apparatus 1 includes: an upper-side holding part 8 and a lower-side holding part 7 that clamp and hold a work-piece W in a vertical direction V; a preload generation mechanism 9 that applies a preload P to the work-piece in the vertical direction through the upper-side holding part; an excitation device 3 that applies vibration U in a horizontal direction H to the work-piece; a load cell 10 that detects a load F applied to the work-piece by the excitation device; and a controller 12 that measures dynamic characteristics K in the horizontal direction of the work-piece on the basis of the load detected by the load cell. The upper-side holding part holds the work-piece in a non-contact manner through an air bearing 20.SELECTED DRAWING: Figure 1

Description

[[TECHNICAL FIELD]]

[0001] The present disclosure relates to a dynamic characteristic measuring apparatus. [[BACKGROUND ART]]

[0002] A dynamic characteristic measuring apparatus for measuring dynamic characteristics of a workpiece is known. The dynamic characteristic measuring apparatus according to Patent Document 1 includes: a base; a support portion placed on an upper part of the base via an air spring so that the support portion can be in a floating state; an electrodynamic exciter provided on the base side of a workpiece attached between the base and the support portion, and configured to apply vertical vibration to the workpiece; and a load washer provided on the support portion side of the workpiece and configured to measure a dynamic load applied to the workpiece. The electrodynamic exciter also applies a vertical preload to the workpiece. [[PRIOR ART DOCUMENTS]] [[PATENT DOCUMENTS]]

[0003] [[Patent Document 1]] Japanese Unexamined Patent Publication No. 2020-085528 [[SUMMARY OF THE INVENTION]] [[Problem to be Solved by the Invention]]

[0004] In the dynamic characteristic measuring apparatus according to Patent Document 1, by applying vertical vibration to the workpiece while applying a vertical preload to the workpiece, it is possible to measure the vertical dynamic characteristic of the workpiece in a state where a vertical static load is applied to the workpiece.

[0005] By the way, there are cases where it is desired to measure the horizontal dynamic characteristic of a workpiece in a state where a vertical static load is applied to the workpiece. In this case, while the workpiece is held by being vertically sandwiched between a pair of holding portions, a vertical preload is applied to the workpiece, and horizontal vibration is applied to the workpiece by an exciter.

[0006] However, in the above configuration, when a workpiece is subjected to vertical preload and horizontal vibration, the workpiece is constrained by the upper and lower holding parts and cannot be freely displaced horizontally. If the workpiece cannot be freely displaced horizontally, this becomes a source of error when measuring the workpiece's horizontal dynamic characteristics.

[0007] Therefore, there was a problem in that it was not possible to accurately measure the horizontal dynamic characteristics of a workpiece when a static load was applied to the workpiece in the vertical direction.

[0008] This disclosure has been made in view of the above, and its purpose is to accurately measure the horizontal dynamic characteristics of a workpiece when a static load is applied to the workpiece in the vertical direction. [Means for solving the problem]

[0009] The dynamic characteristics measuring device according to this disclosure comprises an upper holding part and a lower holding part that hold a workpiece by clamping it in the vertical direction; a preload generating part that applies a vertical preload to the workpiece through the upper holding part or the lower holding part; an excitation part that applies horizontal vibration to the workpiece; a load sensor that detects the load applied to the workpiece by the excitation part; and a control unit that measures the horizontal dynamic characteristics of the workpiece based on the load detected by at least the load sensor, wherein at least one of the upper holding part and the lower holding part holds the workpiece without contact.

[0010] In this configuration, the dynamic characteristics measuring device holds the workpiece by clamping it vertically between the upper and lower holding parts, applies a vertical preload to the workpiece using the preload generation unit, and applies horizontal vibration to the workpiece using the vibration excitation unit. The load on the workpiece by the vibration excitation unit is detected by a load sensor, and the horizontal dynamic characteristics of the workpiece are measured by the control unit based on this load.

[0011] Here, since at least one of the upper and lower holding parts does not contact the workpiece, even if a horizontal vibration is applied to the workpiece while a vertical preload is applied to it, the workpiece can be freely displaced horizontally between the upper and lower holding parts. Because the workpiece can be freely displaced horizontally, errors are less likely to occur when measuring the horizontal dynamic characteristics of the workpiece.

[0012] This allows for accurate measurement of the horizontal dynamic characteristics of a workpiece when a static load is applied to it in the vertical direction.

[0013] In one embodiment, at least one of the upper holding portion and the lower holding portion is provided with an air bearing that supports the workpiece without contact.

[0014] With this configuration, an air layer is formed between the surface of the air bearing and the workpiece, allowing the workpiece to be freely displaced horizontally on the surface of the air bearing while the air layer holds the workpiece in the vertical direction.

[0015] In one embodiment, the air bearing is pivotable by a joint.

[0016] This configuration improves the ability of the air bearing to follow the displacement of the workpiece.

[0017] In one embodiment, the workpiece is placed on the lower holding portion, and the upper holding portion holds the workpiece from above without contact.

[0018] With this configuration, the upper and lower holding parts facilitate the holding of the workpiece.

[0019] In one embodiment, a displacement sensor that detects displacement of the workpiece by the excitation unit is provided, and the control unit measures a dynamic spring constant as the dynamic characteristic of the workpiece in the horizontal direction based on the load detected by the load sensor and the displacement detected by the displacement sensor.

[0020] According to this configuration, the dynamic spring constant in the horizontal direction of the workpiece, which is a representative index indicating the dynamic characteristic of the workpiece in the horizontal direction, can be measured with high accuracy.

[0021] In one embodiment, the apparatus comprises: an upper mass portion that holds the upper holding portion; a lower mass portion that holds the lower holding portion; and a frame placed on a foundation, wherein the upper mass portion and the lower mass portion are each supported by the frame via elastic bodies.

[0022] According to this configuration, transmission of resonance from the frame to the upper mass portion and the lower mass portion (the upper holding portion and the lower holding portion) can be suppressed, so that the dynamic characteristic of the workpiece in the horizontal direction can be measured with higher accuracy. Effects of the Invention

[0023] According to the present disclosure, the dynamic characteristic of the workpiece in the horizontal direction in a state where a static load in the vertical direction is applied to the workpiece can be measured with high accuracy. Brief Description of the Drawings

[0024] [Figure 1] Figure 1 is a front view showing the dynamic characteristic measuring apparatus. [Figure 2] Figure 2 is an enlarged front view showing the vicinity of the workpiece in Figure 1. [Figure 3] Figure 3 is a front cross-sectional view showing an air bearing. Mode for Carrying Out the Invention

[0025] Embodiments of the present disclosure will be described in detail below with reference to the drawings. The following description of preferred embodiments is illustrative in nature and is not intended to limit the present disclosure, its applications, or its uses in any way.

[0026] Figure 1 shows a front view of the dynamic characteristics measuring device 1. The dynamic characteristics measuring device 1 measures the dynamic spring constant K as the dynamic characteristics of the workpiece W in the vertical direction (indicated by V) and the horizontal direction (indicated by H). The vertical direction is the vertical direction. The horizontal direction is the direction perpendicular to the vertical direction, and is the left-right direction and / or the front-back direction.

[0027] As shown in Figure 1, the dynamic characteristics measuring device 1 comprises a base 2, a vibration exciter 3 as an excitation unit, a horizontal measuring frame 4, a horizontal measuring lower mass unit 5, a horizontal measuring upper mass unit 6, a horizontal measuring lower holding unit 7, a horizontal measuring upper holding unit 8, a preload generation mechanism 9 as a preload generation unit, a load cell 10 as a load sensor, a displacement sensor 11, a controller 12 as a control unit, a vertical measuring frame 13, a vertical measuring mass unit 14, a vertical measuring lower holding unit 15, and a vertical measuring upper holding unit 16.

[0028] For simplicity, the horizontal measuring frame 4, the horizontal measuring lower mass section 5, the horizontal measuring upper mass section 6, the horizontal measuring lower holding section 7, and the horizontal measuring upper holding section 8 will be simply referred to as frame 4, lower mass section 5, upper mass section 6, lower holding section 7, and upper holding section 8.

[0029] The base 2 is placed on the foundation B, which is, for example, the floor surface of a floor. The base 2 is made of, for example, metal. The base 2 extends horizontally.

[0030] The vibration excitation device 3 is mounted on the mounting plate 13b (described later) of the vertical measurement frame 13 via an air spring (not shown). The vibration excitation device 3 includes an attachment 3a that contacts the object to be excited. The vibration excitation device 3 can change the orientation of the attachment 3a between an orientation facing vertically (not shown) and an orientation facing horizontally (see Figure 1). As a result, the vibration excitation device 3 can excite the object to be excited in both the vertical and horizontal directions.

[0031] The frame 4 is mounted on the base 2 via the slide rail 17. That is, the frame 4 is mounted on the foundation B via the slide rail 17 and the base 2. The frame 4 is made of, for example, metal.

[0032] The frame 4 includes a base plate 4a, a middle plate 4b, a top plate 4c, and support columns 4d. The base plate 4a is placed on the base 2 via a slide rail 17. The middle plate 4b is positioned above the base plate 4a. The top plate 4c is positioned above the middle plate 4b. The base plate 4a, middle plate 4b, and top plate 4c are, for example, rectangular in shape and extend horizontally. The support columns 4d extend vertically and connect the base plate 4a, middle plate 4b, and top plate 4c to each other at their outer periphery.

[0033] The lower mass portion 5 is supported on the bottom plate 4a of the frame 4 via a first air spring 18, which acts as an elastic body. The upper mass portion 6 is supported on the middle plate 4b of the frame 4 via a second air spring 19, which acts as an elastic body. The lower mass portion 5 and the upper mass portion 6 are each, for example, block-shaped weights made of metal. The weight, size, and shape of the lower mass portion 5 and the upper mass portion 6 are set appropriately to avoid resonance. The lower mass portion 5 and the upper mass portion 6 are also called floating masses.

[0034] The lower holding portion 7 is located above the lower mass portion 5. The lower mass portion 5 holds the lower holding portion 7. Specifically, the lower holding portion 7 is fixed to the upper part of the lower mass portion 5. The lower holding portion 7 is, for example, a metal block and extends in the vertical direction. The lower holding portion 7 may be integrally formed with the lower mass portion 5 or it may be composed of a separate component. A plate-shaped mounting base 23 extending in the horizontal direction is fixed to the upper part of the lower holding portion 7 (see Figure 2). As will be described in detail later, a load cell 10 is positioned between the lower holding portion 7 and the mounting base 23.

[0035] The upper holding portion 8 is located below the upper mass portion 6. The upper mass portion 6 holds the upper holding portion 8. Specifically, the upper holding portion 8 is fixed to the lower part of the upper mass portion 6. The upper holding portion 8 is, for example, a metal block and extends in the vertical direction. The upper holding portion 8 penetrates the middle plate 4b of the frame 4 and extends below the middle plate 4b. The upper holding portion 8 may be integrally formed with the upper mass portion 6 or may be composed of a separate component.

[0036] Figure 2 shows an enlarged front view of the vicinity of the workpiece W in Figure 1. As shown in Figure 2, the workpiece W is positioned between the lower holding portion 7 and the upper holding portion 8. The workpiece W rests on the upper surface of the mounting base 23, which is fixed above the lower holding portion 7. The workpiece W is an elastic material, such as vibration-damping rubber. A metal support plate 24 extending horizontally is fixed to the upper surface of the workpiece W.

[0037] Here, an air bearing 20 is provided in the upper holding portion 8. The air bearing 20 is located below the upper holding portion 8 and above the workpiece W. The air bearing 20 extends horizontally. The lower surface (front surface) of the air bearing 20 faces the upper surface of the workpiece W via a support plate 24. There is a small gap A (for example, about a few μm) between the lower surface of the air bearing 20 and the upper surface of the support plate 24. The air bearing 20 is made of, for example, metal.

[0038] Figure 3 shows a front cross-sectional view of the air bearing 20. As shown in Figure 3, the air bearing 20 is connected to the upper holding part 8 via a ball joint 21. The ball joint 21 is a rod-shaped body that extends in the vertical direction. The upper end of the ball joint 21 is fixed to the lower surface of the upper holding part 8. A spherical portion 21a is formed at the lower end of the ball joint 21. The air bearing 20 is connected to the spherical portion 21a of the ball joint 21 and is able to swing vertically and horizontally (forward and backward and left and right) with respect to the spherical portion 21a of the ball joint 21. The air bearing 20 can swing vertically and horizontally relative to the upper holding part 8 by the spherical portion 21a of the ball joint 21.

[0039] A nozzle 20a is formed on the lower surface of the air bearing 20. The nozzle 20a communicates with an external compressor (not shown) via a communication passage 20b that extends inside the air bearing 20. Air is ejected downward from the nozzle 20a. As a result, an air layer (hereinafter sometimes referred to as "air layer A") is formed in the gap A between the lower surface of the air bearing 20 and the upper surface of the support plate 24 (which is fixed to the upper side of the workpiece W). The air bearing 20 supports the workpiece W from above without contact via the air layer A. The upper holding part 8 presses down on the workpiece W from above without contact via the air bearing 20 (air layer A).

[0040] Returning to Figure 2, the upper holding part 8 and the lower holding part 7 hold the workpiece W by sandwiching it in the vertical direction. The upper holding part 8 holds the workpiece W non-contact via the air bearing 20 (air layer A).

[0041] Returning to Figure 1, the preload generation mechanism 9 is comprised of a known electric screw jack mechanism. The preload generation mechanism 9 includes a threaded rod 9a, a support base 9b, and a motor 9c. The threaded rod 9a extends vertically from the base 2 to the middle plate 4b of the frame 4. The support base 9b is engaged with the threaded rod 9a and supports the middle plate 4b of the frame 4 from below. The motor 9c moves the support base 9b vertically by rotating the threaded rod 9a.

[0042] When the support base 9b moves vertically, the middle plate 4b, upper mass section 6, and upper holding section 8 of the frame 4 also move vertically in conjunction. By moving the support base 9b of the preload generation mechanism 9 downward, the upper holding section 8 presses the workpiece W from above downward via the air bearing 20 (air layer A). The preload generation mechanism 9 applies a vertical preload P to the workpiece W through the upper holding section 8 (air bearing 20). The vertical preload P on the workpiece W corresponds to the vertical static load on the workpiece W, and is equivalent to, for example, the weight of the engine in a vehicle. The preload P is, for example, several hundred [N] to several thousand [N].

[0043] As shown in Figure 2, the attachment 3a of the vibration device 3 faces the side of the support plate 24, which is positioned above the workpiece W, and contacts the support plate 24. The vibration device 3 vibrates the attachment 3a in the horizontal direction, thereby imparting a horizontal vibration U to the workpiece W via the support plate 24.

[0044] The load cell 10 is positioned between the mounting base 23, which is located below the workpiece W, and the lower holding portion 7. Various known types of load cells 10 can be applied.

[0045] The load cell 10 detects the horizontal load F applied to the workpiece W by the vibration device 3. Multiple load cells 10 may be provided to correspond to the front-rear and left-right directions. In addition, although not shown in the figures, a load sensor for detecting the vertical preload P applied to the workpiece W may be provided separately. The placement of the load cells 10 varies depending on the system. For example, the load cells 10 may be attached to the side of the mounting base 23 opposite to the vibration device 3.

[0046] The displacement sensor 11 detects the horizontal displacement δ of the workpiece W caused by the vibration device 3. The displacement δ of the workpiece W is mainly caused by the elastic deformation of the workpiece W. Various known methods can be applied as the displacement sensor 11. Alternatively, an acceleration sensor may be used instead of the displacement sensor 11, and the displacement δ may be calculated by integrating the obtained acceleration with the controller 12 described later. In this case, the acceleration sensor functions as the displacement sensor 11. Various known methods can be applied as the acceleration sensor.

[0047] Multiple displacement sensors 11 may be provided to correspond to the front-rear and left-right directions. The displacement sensors 11 are positioned on the side of the support plate 24, which is located above the workpiece W, opposite to the vibration device 3. The placement of the displacement sensors 11 varies depending on the system.

[0048] The controller 12 consists of a microcontroller and a program. The controller 12 is connected to the vibration exciter 3, the preload generation mechanism 9, the load cell 10, and the displacement sensor 11. The controller 12 measures (calculates) the horizontal dynamic spring constant (dynamic characteristic) K of the workpiece W based on the horizontal load F detected by the load cell 10 and the horizontal displacement δ detected by the displacement sensor 11. The dynamic spring constant K [N / mm] is obtained by load F [N] / displacement δ [mm]. If the detected values ​​of load F and displacement δ include vertical components, the controller 12 may convert them to horizontal components.

[0049] As described above, the vibration device 3 can vibrate the object to be vibrated in the vertical direction by positioning the attachment 3a in a position (not shown) facing vertically. Therefore, the dynamic characteristics measuring device 1 has the following configuration in order to measure the vertical dynamic spring constant (dynamic characteristics) K of the workpiece W.

[0050] The vertical measurement frame 13 is placed on the base 2. The vertical measurement frame 13 includes a top plate 13a, a support column 13b that extends vertically and supports the top plate 13a, and a mounting plate 13c that is located below the top plate 13a and supported by the support column 13b. The vertical measurement mass section 14 is supported on the top plate 13a of the vertical measurement frame 13 via a third air spring 22. The vibration exciter 3 is supported on the mounting plate 13c via an air spring (not shown). The vertical measurement lower holding section 15 is connected to the attachment 3a of the vibration exciter 3 when the attachment 3a faces vertically (not shown). The vertical measurement upper holding section 16 is held below the vertical measurement mass section 14.

[0051] The lower and upper holding parts 15 and 16 for vertical measurement hold the workpiece W by clamping it in the vertical direction. The lower and upper holding parts 15 and 16 for vertical measurement apply a vertical preload to the workpiece W through the upper holding part 16 by an electric screw jack mechanism (not shown). The vibration device 3 applies vertical vibration to the workpiece W via the lower holding part 15 for vertical measurement by vibrating the attachment 3a in the vertical direction. Although not shown, there is a vertical load cell for detecting the vertical load applied to the workpiece W by the vibration device 3. There is also a vertical displacement sensor for detecting the vertical displacement of the workpiece W by the vibration device 3. The vertical load cell and vertical displacement sensor are connected to the controller 12.

[0052] (Effects and Benefits) According to this embodiment, the dynamic characteristics measuring device 1 holds the workpiece W between the upper holding part 8 and the lower holding part 7 in the vertical direction, applies a vertical preload P to the workpiece W using the preload generation mechanism 9, and applies a horizontal vibration U to the workpiece W using the vibration excitation device 3. The horizontal load F and horizontal displacement δ of the workpiece W applied by the vibration excitation device 3 are detected by the load cell 10 and the displacement sensor 11, and the horizontal dynamic spring constant (dynamic characteristics) K of the workpiece W is measured by the controller 12 based on the load F and displacement δ.

[0053] Here, since the upper holding part 8 (air bearing 20) does not contact the workpiece W, even if a horizontal vibration U is applied to the workpiece W while a vertical preload P is applied to the workpiece W, the workpiece W can be freely displaced horizontally between the upper holding part 8 (air bearing 20) and the lower holding part 7. Because the workpiece W can be freely displaced horizontally, errors are less likely to occur when measuring the horizontal dynamic spring constant (dynamic characteristic) K of the workpiece W.

[0054] This allows for accurate measurement of the horizontal dynamic spring constant (dynamic characteristic) K of the workpiece W when a static load is applied to the workpiece W in the vertical direction.

[0055] The dynamic characteristics measuring device 1 according to this embodiment is particularly advantageous for accurately measuring, for example, the dynamic spring constant (dynamic characteristics) K of vibration-damping rubber applied to an engine mount that supports the engine with respect to the vehicle body. Furthermore, the dynamic characteristics measuring device 1 is particularly advantageous for accurately measuring the horizontal dynamic spring constant (dynamic characteristics) K of a workpiece W when a high-frequency vibration U (for example, 3 kHz or higher) is applied to the workpiece W.

[0056] An air layer A is formed in the gap A between the surface (bottom surface) of the air bearing 20 and the top surface of the support plate 24 (located above the workpiece W). This allows the workpiece W to be freely displaced horizontally on the surface (bottom surface) of the air bearing 20, while the air layer A holds the workpiece W in the vertical direction.

[0057] Since the air bearing 20 is pivotable via the ball joint 21, the air bearing 20's ability to follow the displacement of the workpiece W is improved.

[0058] The workpiece W is placed on the lower holding part 7, and the upper holding part 8 (air bearing 20) presses the workpiece W from above without contact, making it easier for the upper holding part 8 (air bearing 20) and the lower holding part 7 to hold the workpiece W.

[0059] Since the dynamic characteristics measuring device 1 is equipped not only with a load cell 10 but also with a displacement sensor 11, it can accurately measure the horizontal dynamic spring constant K of the workpiece W, which is a typical indicator representing the horizontal dynamic characteristics of the workpiece W.

[0060] The upper mass section 6 and the lower mass section 5 are supported by the frame 4 via the second air spring 19 and the first air spring 18. This prevents the transmission of resonance from the frame 4 to the upper mass section 6 and the lower mass section 5 (upper holding section 8 and lower holding section 7). It also prevents the transmission of resonance from the frame 4 to the load cell 10 and the displacement sensor 11. As a result, the horizontal dynamic spring constant (dynamic characteristic) K of the workpiece W can be measured with greater accuracy.

[0061] The dynamic characteristics measuring device 1 according to this embodiment is effective in achieving SDG Goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation."

[0062] (Other embodiments) Although this disclosure has been described above with reference to preferred embodiments, this description is not limiting, and various modifications are, of course, possible.

[0063] The air bearing 20 is constructed separately from the upper holding part 8 and connected to the upper holding part 8 by a ball joint 21, but is not limited to this. The type of joint is not limited to a ball joint 21. The joint may be a highly rigid universal joint (flexible joint) (that does not affect high-frequency characteristics), a joint with a curved surface other than a sphere, etc. The joint absorbs vertical vibration vibration when vibration occurs in the horizontal direction. It is preferable that the joint is rigid. The joint is not required. The air bearing 20 may be integrally formed with the upper holding part 8.

[0064] The air bearing 20 may be provided in the lower holding portion 7 instead of the upper holding portion 8. Alternatively, the air bearing 20 may be provided in both the upper holding portion 8 and the lower holding portion 7. In other words, the air bearing 20 only needs to be provided in at least one of the upper holding portion 8 and the lower holding portion 7. At least one of the upper holding portion 8 and the lower holding portion 7 should hold the workpiece W in a non-contact manner via the air bearing 20.

[0065] A magnetic bearing may be used instead of the air bearing 20. Furthermore, other holding methods may be employed as long as at least one of the upper holding portion 8 and the lower holding portion 7 holds the workpiece W in a non-contact manner.

[0066] The mounting base 23 and support plate 24 are optional.

[0067] The preload generation mechanism 9 may apply a vertical preload P to the workpiece W through the lower holding part 7 instead of the upper holding part 8. In this case, the preload generation mechanism 9 may move the bottom plate 4a of the frame 4, the lower mass part 5, and the lower holding part 7 upward. The preload generation mechanism 9 may be hydraulic instead of electrically operated. The preload generation mechanism 9 may apply a vertical preload P to the workpiece W through both the upper holding part 8 and the lower holding part 7.

[0068] The dynamic characteristic K may include not only the dynamic spring constant but also various other indicators that represent the dynamic properties of the workpiece W. The workpiece W is not limited to vibration-damping rubber, but may also be, for example, a coil spring. The vertical direction may include some horizontal component relative to the vertical direction. The horizontal direction may not be perfectly perpendicular to the vertical direction but may intersect it diagonally.

[0069] The displacement sensor 11 is optional. The controller 12 only needs to measure the horizontal dynamic characteristics K of the workpiece W based on the load F detected by at least the load cell 10. [Industrial applicability]

[0070] This disclosure is extremely useful and has high industrial applicability because it can be applied to dynamic characteristics measuring devices. [Explanation of symbols]

[0071] Double job V vertical direction H horizontal direction K is the dynamic spring constant (dynamic characteristics). B. Basics A. Air layer (gap) P Preload U-vibration F load δ displacement 1. Dynamic characteristics measuring device 3. Vibration device (vibration section) 4. Frame for horizontal measurement 5 Lower mass part for horizontal measurement 6 Upper mass part for horizontal measurement 7 Lower holding part for horizontal measurement 8 Upper holding part for horizontal measurement 9. Preload generation mechanism (preload generation unit) 10 Load cell (load sensor) 11 Displacement Sensor 12 Controller (Control Unit) 18. First air spring (elastic body) 19. Second air spring (elastic body) 20 Air Bearings 21 Ball joint (joint)

Claims

1. An upper holding part and a lower holding part that hold the workpiece by clamping it in the vertical direction, A preload generation unit that applies a vertical preload to the workpiece through the upper holding portion or the lower holding portion, An excitation unit that applies horizontal vibration to the workpiece, A load sensor for detecting the load applied to the workpiece by the vibration unit, The system comprises a control unit that measures the horizontal dynamic characteristics of the workpiece based on the load detected by at least the load sensor, At least one of the upper holding portion and the lower holding portion holds the workpiece without contact, A dynamic characteristics measuring device wherein at least one of the upper holding portion and the lower holding portion is provided with an air bearing that supports the workpiece without contact.

2. In the dynamic characteristics measuring device according to claim 1, The aforementioned air bearing is a dynamic characteristics measuring device that can be oscillated by a joint.

3. In the dynamic characteristics measuring device according to claim 1, The workpiece is placed on the lower holding portion. The aforementioned upper holding portion is a dynamic characteristics measuring device that non-contactually holds the workpiece from above.

4. In the dynamic characteristics measuring device according to claim 1, The system includes a displacement sensor that detects the displacement of the workpiece caused by the vibration unit, The control unit is a dynamic characteristics measuring device that measures the dynamic spring constant as the horizontal dynamic characteristic of the workpiece based on the load detected by the load sensor and the displacement detected by the displacement sensor.

5. In the dynamic characteristics measuring device according to claim 1, An upper mass portion that holds the upper holding portion, The lower mass portion that holds the lower holding portion, It comprises a frame that is placed on a foundation, A dynamic characteristics measuring device in which the upper mass portion and the lower mass portion are each supported by the frame via an elastic body.

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