Characteristics measuring equipment

Abstract

To provide a characteristic measuring device capable of maintaining a predetermined preload and smoothly switching a floating mass state and a fixed state.SOLUTION: In a characteristic measuring device 100, a support part 120 includes an air spring 123 and a double fastening mechanism 200 disposed between a middle surface plate 122 and a reaction force part 124, the double fastening mechanism 200 includes a first actuator 210 fixed to the reaction force part 124 and a second actuator 220 fixed to the middle surface plate 122, and the reaction force part 124 is supported in a fixed state while the same is not supported in a floating mass state by the first actuator 210 and the second actuator 220. Accordingly, a conventional problem (variation in a preload) is solved and the floating mass state and the fixed state can be switched smoothly.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] In particular, the present invention relates to a characteristic measuring device that applies a predetermined preload to the test object and then measures the dynamic characteristics and durability under high load of a test object (e.g., vibration-proof rubber or vibration-proof parts) for automobiles, etc. [Background technology]

[0002] In recent years, in addition to vehicles using conventional gasoline engines, hybrid vehicles that use the rotational force of electric motors and electric vehicles (hereinafter referred to as "electric vehicles, etc.") have rapidly become popular, and the vibration range of these electric motors is expanding toward the higher frequency band side than the vibration range of conventional reciprocating engines.

[0003] In characteristic tests on test specimens used in electric vehicles, etc., it is generally necessary to apply a predetermined load (hereinafter referred to as "preload") to the test specimen, assuming the actual vehicle conditions, and then measure the load generated by externally input vibrations (displacement, acceleration, etc.).

[0004] For example, Patent Document 1 (see particularly Figures 2 and 6) describes a characteristic measuring device (hereinafter referred to as a "conventional characteristic measuring device") that includes a base having a vibrator, a measuring unit that measures the characteristics of a test object using a load detector, and a support unit that is placed on the base and supports a reaction unit that functions as a weight via an air spring and a fastening mechanism. Prior to measurement, this characteristic measuring device performs a process in which the test object is sandwiched from above and below by a pair of mounting jigs fixed to the base and the support unit, respectively, and the distance between the pair of mounting jigs is adjusted, and a predetermined preload is applied to the test object, after which vibrations are applied to the test object using the vibrator, and the characteristic values ​​of the test object are measured. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-006056 Summary of the Invention [Problem to be solved by the invention]

[0006] As shown in Fig. 5, in order to accommodate a wide range of vibration frequencies input by a vibrator during a characteristic test, the support section 620 in a conventional characteristic measuring device had to be switched between a state in which the reaction section 624 is supported by air springs 623 relative to an intermediate surface plate 622 (hereinafter referred to as the "floating mass state") (see Fig. 5(a)), and a state in which the reaction section 624 is fastened and fixed to the intermediate surface plate 622 by fastening mechanisms 700 (hereinafter referred to as the "fixed state") (see Fig. 5(b)). As a result, the fixed state is used when the input vibration frequency is below approximately 100 to 150 Hz, and the floating mass state is used from 150 Hz to several kHz.

[0007] Specifically, support unit 620 in the conventional characteristic measuring device includes air spring 623 in a sealed state, stopper 625, and fastening mechanism 700 between intermediate surface plate 622 and reaction force unit 624. Fastening mechanism 700 includes actuator 710 fixed to the lower surface of reaction force unit 624 and locking member 720 fixed to the upper surface of intermediate surface plate 622. Actuator 710 includes cylinder 711 fixed to the lower surface of reaction force unit 624 and movable unit 712 having lower enlarged diameter portion 712a and upper enlarged diameter portion 712b. Here, lower enlarged diameter portion 712a of movable unit 712 can be locked with locking member 720, while upper enlarged diameter portion 712b of movable unit 712 is housed in cylinder 711.

[0008] First, when transitioning from the fixed state to the floating mass state (from FIG. 5(b) to FIG. 5(a)), drive oil is supplied to the upper sealed space C1 defined by the cylinder 711 and the upper surface of the upper expanded diameter portion 712b, causing the movable portion 712 to move downward (see the solid arrow A1 in FIG. 5(a)), and the engagement between the lower expanded diameter portion 712a and the locking member 720 is released. This generates a restoring force in the compressed air spring 623, causing the reaction force portion 624 to move upward (see the hollow arrow B1 in FIG. 5(a)).

[0009] Next, when transitioning from the floating mass state to the fixed state (from FIG. 5(a) to FIG. 5(b)), drive oil is supplied to the lower sealed space C2 defined by the cylinder 711 and the lower surface of the upper expanded diameter portion 712b, causing the movable portion 712 to move upward (see the solid arrow A2 in FIG. 5(b)), and the lower expanded diameter portion 712a to engage with the engaging member 720. As a result, the actuator 710 compresses the air spring 623, while moving the reaction force portion 624 downward until it abuts against the stopper 625 (see the hollow arrow B2 in FIG. 5(b)).

[0010] As described above, when switching between the floating mass state and the fixed state, the height position of the reaction force portion 624 fluctuates relative to the intermediate surface plate 622. Furthermore, in the fixed state (see FIG. 5(b)), the air spring 623 is compressed further downward by the actuator 710 compared to the floating mass state (see FIG. 5(a)), which makes it easier for air to leak from the air spring 623 to the outside. As a result, the positional fluctuation of the reaction force portion 624 that occurs when switching from the fixed state to the floating mass state is not reproducible and may not be the same fluctuation. This fluctuation in the position of the reaction force portion 624 also fluctuates the distance between the pair of mounting jigs that apply a predetermined preload to the test object, resulting in a problem of significant fluctuation in the preload on the test object (hereinafter referred to as the "conventional problem (preload fluctuation)").

[0011] To solve this conventional problem (preload fluctuation), it was necessary to adjust the distance between a pair of mounting jigs that support the test object from above and below each time the test object was switched between the floating mass state and the fixed state, which was time-consuming and labor-intensive.

[0012] An object of the present invention is to provide a characteristics measuring device that can smoothly switch between a floating mass state and a fixed state while maintaining a predetermined preload. [Means for solving the problem]

[0013] In order to solve the above problem, a characteristic measuring device is provided which comprises a base, a support part placed on top of the base, and a measurement part which is arranged between the base and the support part and to which a test object is attached, the support part comprising an intermediate base plate fixed to the base, a reaction part which functions as a weight, and an air spring and a double fastening mechanism which are respectively arranged between the intermediate base plate and the reaction part, the air spring and the double fastening mechanism supporting the reaction part without changing its height in a floating mass state and a fixed state in order to maintain a predetermined preload on the test object, the double fastening mechanism comprising a first actuator fixed to the reaction part and a second actuator fixed to the intermediate base plate, the reaction part not being supported by the first actuator and the second actuator in the floating mass state, and being supported by the first actuator and the second actuator in the fixed state.

[0014] In addition, in the above-mentioned characteristic measuring device, the first actuator may include a first movable part that can be attached to and detached from the lower surface of the reaction part, and the second actuator may include a second movable part that passes through the reaction part and the first movable part and has an engaging part that can be attached to and detached from the lower end of the first movable part, and in the floating mass state, the upper and lower ends of the first movable part may be spaced apart in the axial direction from the reaction part and the second movable part, respectively, and in the fixed state, the upper and lower ends of the first movable part may be in contact with the reaction part and the second movable part, respectively.

[0015] In addition, in the above-mentioned characteristic measuring device, the air spring and the double fastening mechanism support the reaction section without changing its height in a temporary fixed state between the floating mass state and the fixed state, and the reaction section may be supported only by the first actuator in the temporary fixed state.

[0016] In addition, in the above-mentioned characteristic measuring device, the first actuator may have a first movable part that can be attached to and detached from the underside of the reaction part, and the second actuator may have a second movable part that passes through the reaction part and the first movable part and has an engaging part that can be attached to and detached from the lower end of the first movable part, and in the temporarily fixed state, the upper end of the first movable part may be abutted against the reaction part and the lower end of the first movable part may be separated from the second movable part, thereby supporting the reaction part relative to the intermediate base without changing the height of the reaction part.

[0017] The characteristic measuring device may further include a displacement detector that measures the displacement of the reaction force section at least in the floating mass state, and a reaction force section height holding means that controls the pressure supplied to the air spring based on a displacement signal from the displacement detector. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a characteristics measuring device that can smoothly switch between a floating mass state and a fixed state while maintaining a predetermined preload. [Brief explanation of the drawings]

[0019] [Figure 1] 1A and 1B are schematic diagrams showing an example of a characteristic measuring device according to an embodiment of the present invention, in which FIG. 1A is a front view including a partial cross section, and FIG. 1B is a top view. [Figure 2] FIG. 2 is an enlarged cross-sectional view of the double fastening mechanism of FIG. 1. [Figure 3] 3A to 3C are diagrams illustrating the operating states of the double fastening mechanism of FIG. 2, where (a) shows the floating mass state, (b) shows the provisionally fixed state, and (c) shows the fixed state. [Figure 4] 2 is a diagram illustrating a reaction force portion height holding means in the characteristic measuring device of FIG. 1. FIG. [Figure 5] 1A and 1B are enlarged cross-sectional views of a fastening mechanism and an air spring used in a conventional characteristic measuring device, where (a) shows the floating mass state and (b) shows the fixed state. DETAILED DESCRIPTION OF THE INVENTION

[0020] An embodiment of the present invention will be described in detail with reference to Figures 1 to 4. However, the present invention is not limited to this embodiment.

[0021] <Terminology> In this specification and claims, "upper" and "lower" correspond to the upper and lower in Figure 1(a) and indicate the relative positional relationship of each component, not the absolute positional relationship. The "air spring" in the claims refers to the "support portion air spring" in this specification.

[0022] <About the characteristic measurement equipment> An example of a characteristic measuring device 100 according to an embodiment of the present invention will be described using Fig. 1. Note that, for the sake of explanation, the left side of the characteristic measuring device 100 in the figure is shown as a partial cross section. This characteristic measuring device 100 is a measuring device that measures the dynamic properties of anti-vibration rubber for automobiles, etc., as standardized in, for example, SRIS3503 (Japan Rubber Association Standard).

[0023] The characteristic measuring device 100 comprises a base 110, a support part 120 that is placed on top of the base 110 and supports a reaction part 124 that functions as a weight in a floating mass state or a fixed state via a support part air spring (air spring) 123 and a double fastening mechanism 200, a measuring part 130 that is arranged between the base 110 and the support part 120, and a control system (not shown). Each component of the characteristic measuring device 100 will be described below in order.

[0024] <About the base> The base 110 includes legs 111 , a base air spring 112 , a base mount 113 , and an electrodynamic vibration exciter 114 .

[0025] Four legs 111 are arranged at positions that come into contact with the ground, and fix characteristic measurement device 100 to the ground.

[0026] The base air springs 112 are elastic bodies placed on the top of the four legs 111, and four of them are arranged. By providing these base air springs 112, it is possible to prevent vibrations from being transmitted between the ground and the characteristic measuring device 100 during a vibration test.

[0027] Base mount unit 113 is made of a metal such as iron and has a relatively large mass, has a roughly square plate shape in a plan view, and has an opening 113a in the center that widens in diameter in a stepped manner toward the bottom. Base mount unit 113 is installed via base air springs 112 so that the top surface of base mount unit 113 is horizontal.

[0028] The electrodynamic vibration exciter 114 is fixed to the base mount 113 with its upper portion housed in an opening 113a of the base mount 113. The electrodynamic vibration exciter 114 is electrically connected to a control system and drives an electrodynamic vibration exciter vibration table 134 installed above the electrodynamic vibration exciter 114. The electrodynamic vibration exciter 114, together with the base mount 113, has sufficient mass, and therefore, like the base air spring 112, plays a role in preventing vibration transmission.

[0029] In the present embodiment, the base 110 has the base air springs 112 arranged between the four legs 111 and the base stand 113, and the lower parts of the legs 111 are fixed to the ground, but this is not limited to this. For example, the base 110 may be in any form as long as it prevents the transmission of vibrations and can withstand external factors such as earthquakes.

[0030] <About the support part> The support portion 120 includes a support column 121, an intermediate surface plate 122, a support portion air spring 123, a double fastening mechanism 200, and a reaction portion .

[0031] Four support columns 121 are arranged, and the lower portions are fixed to the base mount section 113, and the upper portions are fixed to the intermediate surface plate 122. The support columns 121 in this embodiment are extendable in the axial direction, and for example, by extending them in the axial direction, it becomes possible to house the measurement section 130 in a thermostatic chamber and measure a large-sized test object 132.

[0032] Intermediate surface plate 122 has a frame shape in a plan view and includes a through-hole 122a in the center. Double fastening mechanisms 200 are disposed at the corners of intermediate surface plate 122, and two support air springs 123 are disposed on each side connecting the corners. In this embodiment, double fastening mechanisms 200 and support air springs 123 are disposed at the corners and sides of intermediate surface plate 122, respectively, but this is not limiting, and for example, support air springs 123 and double fastening mechanisms 200 may be disposed at the corners and sides of intermediate surface plate 122, respectively.

[0033] The support air springs 123 are elastic bodies disposed between the intermediate surface plate 122 and the reaction force portion 124. In a high-frequency vibration state or the like, the support air springs 123 can be in a floating mass state that blocks transmission of vibrations such as resonance between the base 110 and the reaction force portion 124. For the sake of explanation, this embodiment shows the use of eight support air springs 123, but the number is not limited to this and any other number of support air springs 123 may be used as long as a floating mass state can be formed.

[0034] The double fastening mechanism 200 is disposed between the intermediate surface plate 122 and the reaction force portion 124, and includes two actuators (see the first actuator 210 and the second actuator 220 in FIG. 2 ), as will be described in detail later. In a fixed state, the double fastening mechanism 200 firmly connects the base pedestal portion 113, the support column 121, the intermediate surface plate 122, and the reaction force portion 124, providing high rigidity and enabling static spring constant measurement of the test object 132 and measurements at low vibration frequencies of approximately 100 to 150 Hz or less. While the present embodiment illustrates the use of four double fastening mechanisms 200 for the sake of explanation, other numbers of double fastening mechanisms 200 may be used as long as a fixed state with sufficient connection rigidity can be configured. As will be described in detail later, the double fastening mechanism 200 of this embodiment drives two actuators to maintain the height position of the reaction force section 124 unchanged when switching between the floating mass state, the temporary fixed state, and the fixed state via the double fastening mechanism 200 and the support air spring 123. This eliminates the conventional problem (fluctuations in preload) and enables smooth switching between the floating mass state and the fixed state.

[0035] The reaction force part 124 functions as a weight, and its lower part is inserted into the through-hole 122a of the intermediate surface plate 122. The resonance frequency of this reaction force part 124 needs to be higher than the frequency of the measurement area to be measured, so it is set to a relatively large mass (for example, 1500 kg or more).

[0036] <About the measurement unit> The measuring unit 130 includes a pair of mounting jigs 131, a test object 132, a load washer 133, and an electrodynamic vibration exciter vibration table 134.

[0037] The pair of mounting jigs 131 includes an upper mounting jig 131a installed below the reaction force portion 124 and a lower mounting jig 131b installed above the electrodynamic vibration exciter vibration table 134.

[0038] The test object 132 is a vibration-isolating rubber that includes a phase element, such as a mass-equipped vibration-isolating rubber for automobiles or a liquid-filled vibration-isolating rubber. The test object 132 is measured while being held between a pair of mounting jigs 131. Note that the test object 132 in this embodiment is a vibration-isolating rubber for automobiles or the like, but is not limited to this and may be general industrial rubber.

[0039] The load washer 133 is placed above the test object 132 via an upper mounting jig 131a. The load washer 133 is a highly rigid piezoelectric element with a fast response speed and a small measurement threshold, and therefore constitutes a dynamic load measuring instrument that measures the dynamic load applied to the test object 132.

[0040] The electrodynamic vibration exciter vibration table 134 is installed above the electrodynamic vibration exciter 114 and is controlled by a control system. A diaphragm (not shown) and a coil section (not shown) are directly connected to the electrodynamic vibration exciter vibration table 134, and an alternating current magnetic field is arranged around them, and the electrodynamic vibration exciter vibration table 134 is driven by applying an alternating current to this coil. Note that the vibration frequency range of the electrodynamic vibration exciter 114 in this embodiment is up to 3 kHz, but is not limited to this and may be, for example, 3 kHz or higher.

[0041] <About the control system> Although not shown, the control system mainly includes a main control device and a power amplifier housing.

[0042] The main control device controls the characteristics measuring device 100 and is connected to the power supply and characteristics measuring device 100 via a starter and control lines. The main control device mainly includes a main servo controller, a charge amplifier, a vibration exciter control panel, an uninterruptible power supply, a user interface, etc. Signals such as dynamic load and displacement are input to the main servo controller from various sensors in the characteristics measuring device 100, and various measurements and calculations are performed.

[0043] The power amplifier housing is controlled by signals from the vibration exciter operation panel of the main control device, and controls, for example, the operation of the vibration table 134 of the electrodynamic vibration exciter 114 of the characteristic measuring device 100 .

[0044] <Details of the double fastening mechanism> The detailed configuration of the double fastening mechanism 200 will be described with reference to Figure 2. Note that the double fastening mechanism 200 in the figure is shown in partial cross section for the purpose of explanation.

[0045] The dual fastening mechanism 200 includes a first actuator 210 and a second actuator 220 .

[0046] <About the first actuator> The first actuator 210 comprises a first cylinder 211, a first movable part 212 housed in the first cylinder 211, a first hydraulic supply / discharge path 213, a first biasing means 214 that biases the first movable part 212 downward, and a fixed member 215 that is fixed to the lower end of the first movable part 212 and supports the lower part of the first biasing means 214.

[0047] The first cylinder 211 is a hollow cylindrical member fixed to the upper part of the intermediate surface plate 122, and has a stepped inner circumferential surface that penetrates along the direction of the axis C. On this inner circumferential surface, an upper small diameter portion 211a, a first piston accommodating portion 211b, a lower guide portion 211c, and a first spring accommodating portion 211d are formed successively so that the diameter repeatedly decreases and increases from top to bottom. In addition, a recess 122b is formed in the intermediate surface plate 122 so as to be continuous with the inner circumferential surface of the first cylinder 211.

[0048] The first movable part 212 is a hollow cylindrical member accommodated in the first cylinder 211 and the recess 122b of the intermediate surface plate 122, and has a through-hole 212a that penetrates with the same diameter along the direction of the axis C, and a stepped outer circumferential surface. On this outer circumferential surface, an upper shaft part 212b and a first piston part 212c are formed successively from top to bottom, with the diameters of which successively increase, and a stepped part 212d, a lower shaft part 212e, and a spring abutment part 212f are formed successively with the diameters of which successively decrease.

[0049] Here, the relative positioning of the first movable part 212 and the first cylinder 211 will be described. First, a radial gap is formed between the upper shaft part 212b and the upper small diameter part 211a. Furthermore, a predetermined radial gap is formed between the step part 212d and the first piston accommodating part 211b, and between the spring abutment part 212f and the first spring accommodating part 211d, in order to define the first sealed space S1 and a space for accommodating the first biasing means 214, as will be described in detail later. Furthermore, a very small gap is formed between the first piston part 212c and the first piston accommodating part 211b, and between the lower shaft part 212e and the lower guide part 211c, in order to enable relative sliding in the direction of the axis C.

[0050] The first hydraulic supply / discharge path 213 penetrates from the outer peripheral surface to the inner peripheral surface of the first cylinder 211, and by switching between a connected state allowing supply / discharge or a non-connected state, it is possible to supply, discharge, and maintain the driving fluid in the first sealed space S1 defined by the first cylinder 211 and the first movable part 212.

[0051] 2, the first sealed space S1 never becomes zero and is always fluidly connected to the first hydraulic supply / discharge path 213, so that hydraulic pressure can be smoothly supplied to and discharged from the first sealed space S1. By controlling the hydraulic pressure of the driving fluid via this first hydraulic supply / discharge path 213, the first movable part 212 can be moved to a desired position in the direction of the axis C, and the first movable part 212 can be moved toward and away from the reaction force part 124.

[0052] The first biasing means 214 is made of, for example, a disc spring, and is accommodated in the first spring accommodating portion 211d and the recess 122b of the intermediate surface plate 122, and is sandwiched in the direction of the axis C by the lower guide portion 211c and a fixing member 215 fixed to the lower end portion of the first movable portion 212. As a result, the first movable portion 212 is constantly urged downward by the first biasing means 214. Therefore, when the first hydraulic supply / discharge path 213 is in a dischargeable communicating state, the driving fluid is discharged from the first sealed space S1, and the first movable portion 212 is disposed at a position spaced downward from the reaction force portion 124. On the other hand, when the first hydraulic supply / discharge path 213 is in a connected state allowing supply, hydraulic pressure of the driving fluid that overcomes the combined force of the biasing force of the first biasing means 214 and the weight of the first movable part 212 is supplied to the first sealed space S1, thereby positioning the first movable part 212 in a position abutting the reaction force part 124.

[0053] <About the second actuator> The second actuator 220 includes a second cylinder 221, a second movable part 222 housed in the second cylinder 221, a second hydraulic supply / discharge path 223, and a second biasing means 224 that biases the second movable part 222 downward.

[0054] The second cylinder 221 is a hollow cylindrical member fixed to the upper part of the flange 124a of the reaction force part 124, and has a stepped inner circumferential surface penetrating along the direction of the axis C. On this inner circumferential surface, a communication hole 221a, a second spring accommodating part 221b, and a second piston accommodating part 221c are formed successively from top to bottom, with the diameters successively increasing, and a lower end guide part 221d being formed with a diameter decreasing. In addition, an insertion hole 124b is formed in the flange 124a of the reaction force part 124, which extends with the same diameter along the direction of the axis C so as to be continuous with the inner circumferential surface of the second cylinder 221.

[0055] The second movable part 222 is a solid cylindrical member that extends with the same diameter along the direction of the axis C and has an axial part 222a that is inserted into the insertion hole 124b of the flange part 124a and the through hole 212a of the first movable part 212, a second piston part 222b that is provided with an expanded diameter at the upper end of the axial part 222a and is accommodated in the second cylinder 221, and an engagement part 222c that is formed with an expanded diameter at the lower end of the axial part 222a and is accommodated in the recess 122b of the intermediate base plate 122.

[0056] Here, we will describe the relative positions of the second movable part 222, the second cylinder 221, the flange part 124a, and the first movable part 212. First, very small gaps are formed between the second piston part 222b and the second piston accommodating part 221c, and between the shaft part 222a and the lower end guide part 221d to enable relative sliding in the direction of the axis C. Furthermore, gaps are formed in the radial direction between the shaft part 222a and the insertion hole 124b, and between the shaft part 222a and the through-hole 212a.

[0057] The second hydraulic pressure supply / discharge path 223 penetrates from the outer peripheral surface to the inner peripheral surface of the second cylinder 221, and by switching between a connected state allowing supply / discharge and a disconnected state, can supply, discharge, and maintain the driving fluid to the second sealed space S2 defined by the second cylinder 221 and the second movable part 222. By controlling the hydraulic pressure of the driving fluid via this second hydraulic pressure supply / discharge path 223, the second movable part 222 can be moved to a desired position in the direction of the axis C, and the second movable part 222 can be moved toward or away from the first movable part 212.

[0058] The second biasing means 224 is made of, for example, a coil spring, is housed in the second cylinder 221, and is sandwiched in the direction of the axis C by the second spring housing portion 221b and a spring bearing portion 222b1 provided on the second piston portion 222b. As a result, the second movable portion 222 is constantly urged downward by the second biasing means 224. Therefore, when the second hydraulic pressure supply / discharge path 223 is in a dischargeable communicated state, the driving fluid is discharged from the second sealed space S2, and the engaging portion 222c of the second movable portion 222 is disposed at a position spaced downward from the fixed member 215. On the other hand, when the second hydraulic supply / discharge path 223 is in a connected state allowing supply, hydraulic pressure of the driving fluid that overcomes the combined force of the biasing force of the second biasing means 224 and the weight of the second movable part 222 is supplied to the second sealed space S2, thereby positioning the engaging part 222c of the second movable part 222 in a position abutting the fixed member 215.

[0059] <Operation status of the double fastening mechanism> The operating state of the double fastening mechanism 200 will be described using Figure 3. Note that the reference height h0 in the figure indicates the height of the lower surface of the flange portion 124a of the reaction force portion 124, and indicates that there is no vertical movement of the reaction force portion 124 in any of the floating mass state, the temporarily fixed state, and the fixed state.

[0060] <When transitioning from floating mass state to temporary fixed state to fixed state> First, the double fastening mechanism 200 in the floating mass state will be described. As shown in Fig. 3(a), the first actuator 210 is in a state in which drive oil can be discharged from the first sealed space S1 via the first hydraulic supply / discharge path 213, so the first movable part 212 is urged downward by the first biasing means 214, and the lower surface of the step part 212d of the first movable part 212 is held in a position in which it abuts against the upper surface of the lower guide part 211c of the first cylinder 211. Similarly, the second actuator 220 is in a state in which drive oil can be discharged from the second sealed space S2 via the second hydraulic supply / discharge path 223, so the second movable part 222 is urged downward by the second biasing means 224, and the lower surface of the second piston part 222b of the second movable part 222 is held in a position in which it abuts against the upper surface of the lower end guide part 221d of the second cylinder 221.

[0061] As a result, the first movable part 212 is separated from the flange part 124a of the reaction part 124 by a distance l1 in the direction of the axis C, and the first movable part 212 is separated from the engaging part 222c of the second movable part 222 by a distance l2 in the direction of the axis C. Therefore, the reaction part 124 is not supported by the first actuator 210 and the second actuator 220, and is in a floating mass state. In this floating mass state, the first hydraulic pressure supply / discharge path 213 and the second hydraulic pressure supply / discharge path 223 are in a state in which drive oil can be discharged or are in a non-communicating state.

[0062] Next, the double fastening mechanism 200, which transitions from the floating mass state to the provisionally fixed state, will be described. As shown in FIG. 3(b), drive oil is supplied to the first sealed space S1 of the first actuator 210 via the first hydraulic supply / discharge path 213 (see arrow d1 in the figure), and the first movable part 212 moves upward against the first biasing means 214 (see arrow M1 in the figure). Thereafter, the supply of drive oil is stopped when the first movable part 212 abuts against the flange 124a of the reaction force part 124. At this time, the amount of drive oil supplied to the first actuator 210 is controlled so that the first movable part 212 softly lands on the reaction force part 124, and therefore the reaction force part 124 does not move upward before or after the abutment. On the other hand, since no driving oil is supplied to the second sealed space S2 of the second actuator 220 via the second hydraulic supply / discharge path 223, the second movable part 222 does not move.

[0063] As a result, the reaction force portion 124 is in a temporarily fixed state in which it is supported from below only by the first actuator 210. In this temporarily fixed state, the first hydraulic pressure supply / discharge path 213 is in a non-communicating state, while the second hydraulic pressure supply / discharge path 223 is in a state in which the driving oil can be discharged or is in a non-communicating state.

[0064] Next, the double fastening mechanism 200, which transitions from the provisionally fixed state to the fixed state, will be described. As shown in FIG. 3(c), the first actuator 210 does not receive drive oil from the first sealed space S1 via the first hydraulic supply / discharge path 213, and therefore the first movable part 212 does not move. On the other hand, the second actuator 220 receives drive oil from the second sealed space S2 via the second hydraulic supply / discharge path 223 (see arrow d2 in the figure), and the second movable part 222 moves upward against the second biasing means 224 (see arrow M2 in the figure). Thereafter, the supply of drive oil is stopped when the engaging part 222c of the second movable part 222 abuts against the fixed part 121e of the first movable part 212. At this time, the second movable part 222 is fixed to the reaction part 124 in the direction of the axis C via the first movable part 212, so that the intermediate base plate 122 to which the first actuator 210 is fixed and the reaction part 124 to which the second actuator 220 is fixed can be firmly fastened and fixed.

[0065] As a result, the reaction force portion 124 is in a fixed state in which it is firmly fastened and fixed from below by the first actuator 210 and the second actuator 220. In this fixed state, the first hydraulic pressure supply / discharge path 213 and the second hydraulic pressure supply / discharge path 223 are in a non-communicating state.

[0066] <When transitioning from fixed state to temporary fixed state to floating mass state> A description that overlaps with the case where the double fastening mechanism 200 transitions from the floating mass state to the provisionally fixed state and then to the fixed state will be omitted.

[0067] First, we will explain the double fastening mechanism 200, which transitions from the fixed state to the provisionally fixed state. As shown in FIG. 3(c), in the first actuator 210, the first hydraulic pressure supply / discharge path 213 is in a non-communicating state, and therefore the first movable part 212 does not move. On the other hand, the second actuator 220 is in a state in which the drive oil in the second sealed space S2 can be discharged via the second hydraulic pressure supply / discharge path 223 (see arrow d3 in the figure), and therefore the second movable part 222 is biased by the second biasing means 224 and moves downward (see arrow M3 in the figure). Thereafter, the discharge of the drive oil stops when the engaging part 222c of the second movable part 222 is positioned away from the first movable part 212.

[0068] Next, the double fastening mechanism 200, which transitions from the provisionally fixed state to the floating mass state, will be described. As shown in Fig. 3(b), the first actuator 210 is set in a state in which the drive oil in the first sealed space S1 can be discharged via the first hydraulic supply / discharge path 213 (see arrow d4 in the figure), and the first movable part 212 is biased by the first biasing means 214 and moves downward (see arrow M4 in the figure). Thereafter, the discharge of the drive oil stops when the first movable part 212 is positioned away from the flange 124a of the reaction force part 124.

[0069] Next, the double fastening mechanism 200 in the floating mass state will be described. As shown in Fig. 3(a), since no driving oil is supplied to the first actuator 210 and the second actuator 220, the first movable part 212 and the second movable part 222 do not move.

[0070] In this way, in the temporary fixed state and the fixed state, the reaction force section 124 is supported and fixed to the intermediate base plate 122 while maintaining the height position of the reaction force section 124 in the floating mass state, so when the floating mass state is resumed, the reaction force section 124 does not move in the vertical direction.

[0071] As described above, the double fastening mechanism 200 of this embodiment can maintain the height position of the reaction force portion 124 (see the reference height h0 in FIG. 3 ) unchanged via the double fastening mechanism 200 and the support air spring 123 when switching between the floating mass state, the temporary fixed state, and the fixed state by driving the first actuator 210 and the second actuator 220. This eliminates the conventional problem (preload fluctuation) and enables smooth switching between the floating mass state and the fixed state. Furthermore, because the vertical compressive force applied to the support air spring 123 of this embodiment does not change between the floating mass state, the temporary fixed state, and the fixed state, it is possible to prevent a sudden increase in the internal pressure of the support air spring 123, which would otherwise cause air leakage, when switching between these states. Furthermore, unlike the conventional fastening mechanism 700 (see Figure 5), the double fastening mechanism 200 in this embodiment employs a temporary fixed state, and by gradually increasing the supporting force for the reaction force portion 124 from an unsupported floating mass state, to a temporary fixed state in which it is supported by a soft landing from below, to a fixed state in which it is firmly fastened and fixed from below, or conversely, by gradually decreasing the supporting force from a fixed state, to a temporary fixed state, to a floating mass state, it is possible to prevent sudden fluctuations from occurring in the reaction force portion 124.

[0072] <Means for maintaining the height of the reaction force part> As described above, the characteristic measuring device 100 of this embodiment employs the double fastening mechanism 200 instead of the conventional fastening mechanism 700 (see FIGS. 5(a) and 5(b)). This eliminates the conventional problem (preload fluctuation) without changing the height position of the reaction force portion 124, and sufficiently enables smooth switching between the floating mass state and the fixed state. Furthermore, the inventors further considered the vertical behavior of the reaction force portion 124 when the double fastening mechanism 200 is employed. As a result, they discovered that, particularly when switching from the fixed state (see FIG. 3(c)) to the floating mass state (see FIG. 3(a)), the height position of the reaction force portion 124 may shift slightly below the desired reference height h0, and that this is due to the airtightness of the support portion air spring 123. Specifically, when in a fixed state, the support air spring 123 is compressed for a long period of time, causing a small amount of air leakage, which then leads to a floating mass state, and this can occur because the support air spring 123 supports the reaction force part 124 alone.

[0073] To solve this new problem (hereinafter referred to as "fluctuation of the reaction force part in a floating mass state"), a reaction force part height maintaining means 300 is employed in addition to a double fastening mechanism 200 in the support part 120, as shown in Figure 4. Here, for convenience of explanation, Figure 4 shows one support part air spring 123 provided with one reaction force part height maintaining means 300, but the other support part air springs 123 are also provided with similar reaction force part height maintaining means 300.

[0074] Reaction force portion height maintaining means 300 includes a proportional pressure control valve 310, a pressure supply source 320, a silencer 330, a displacement detector 340, and a PID control unit 350. Each component of reaction force portion height maintaining means 300 will be described below in order.

[0075] The proportional pressure control valve 310 adjusts the supply pressure PS steplessly based on an external control value u, and is fluidly connected to one side with a pressure supply source 320 that supplies compressed air at high pressure (0.4 MPa or more) and a silencer 330 that discharges noise into the external environment, and to the other side with a support air spring 123.

[0076] The displacement detector 340 is a wire-type displacement meter equipped with a wire portion 340a. The upper end of this wire portion 340a is fixed to the flange portion 124a of the reaction force portion 124, and the wire portion 340a outputs a displacement position H1, which is a displacement signal corresponding to expansion and contraction. Note that the displacement detector 340 in this embodiment is a contact-type displacement meter, but is not limited to this, and for example, a non-contact displacement meter (e.g., a laser-type displacement meter) or the like may also be used.

[0077] The PID control unit 350 combines proportional control, integral control, and differential control, and calculates a control value u from three elements: the error e between the displacement position H1 and the target position Hr, and its integral and derivative, to control the supply pressure PS. By controlling the supply pressure PS using this PID control unit 350, the displacement position H1 of the reaction force unit 124 can be made to reach the target position Hr stably and quickly while suppressing overshoot.

[0078] <Operation of the reaction force section height maintaining means> The reaction force section height maintaining means 300 is set to operate particularly when switching from the provisionally fixed state to the floating mass state, and in the floating mass state, in which the height position of the reaction force section 124 may fluctuate.

[0079] Here, when displacement position H1 is lower than target position Hr, PID control unit 350 controls proportional pressure control valve 310 so that supply pressure PS increases, resulting in an increase in the internal pressure of support portion air spring 123 and movement of reaction force portion 124 upward toward target position Hr (see the upward arrow in FIG. 4). On the other hand, when displacement position H1 is higher than target position Hr, PID control unit 350 controls proportional pressure control valve 310 so that supply pressure PS decreases, resulting in a decrease in the internal pressure of support portion air spring 123 and movement of reaction force portion 124 downward toward target position Hr (see the downward arrow in FIG. 4).

[0080] In this way, the reaction force section height holding means 300 of this embodiment controls the supply pressure PS to the support section air spring 123 when switching from the temporary fixed state to the floating mass state and in the floating mass state, thereby enabling the displacement position H1 of the reaction force section 124 to reach the target position Hr stably and quickly. This solves the new problem (fluctuation of the reaction force section in the floating mass state) and enables smoother switching between the floating mass state and the fixed state.

[0081] In this embodiment, the reaction force section height holding means 300 is set to operate at least in the floating mass state (when switching from the temporary fixed state to the floating mass state, and in the floating mass state), but is not limited to this and may be set to operate at all times (in the floating mass state, temporary fixed state, and fixed state), for example.

[0082] <Other> The present invention is not limited to the above-described embodiment, and appropriate changes and modifications can be made without departing from the technical concept of the present invention.

[0083] 100 Characteristics measuring device 110 Base 111 Legs 112 Base air spring 113 Base stand 114 Electrodynamic vibrator 120 Support part 121 Post 122 Medium surface plate 122a Penetration 122b Recess 123 Support air spring (air spring) 124 Reaction section 124a Tsuba 124b Insertion hole 130 Measuring section 131 Pair of mounting jigs 131a Upper mounting jig 131b Lower mounting jig 132 Test Subject 133 Road washer 134 Electrodynamic vibrator vibration table 200 Double fastening mechanism 210 First Actuator 211 First Cylinder 211a Upper end small diameter section 211b First piston housing 211c Lower guide part 211d First spring housing 212 First moving part 212a Through hole 212b Upper shaft part 212c First piston part 212d Step 212e Lower shaft part 212f Spring contact part 213 First hydraulic supply and discharge route 214 first biasing means 215 Fixing member 220 Second Actuator 221 Second Cylinder 221a Communication hole 221b Second spring housing 221c Second piston housing 221d Lower end guide 222 Second moving part 222a Shaft 222b Second piston part 222b1 Spring bearing part 222c Engagement part 223 Second hydraulic supply and discharge route 224 second biasing means 300 Reaction section height maintaining means 310 Proportional Pressure Control Valve 320 Pressure Supply Source 330 silencer 340 Displacement Detector 340a Wire section 350 PID control unit C axis e error H1 Displacement position Hr target position h0 Reference height l1: Distance between the first movable part and the flange of the reaction part l2: Distance between the first movable part and the engaging part of the second movable part PS supply pressure S1 First enclosed space S2 Second enclosed space u control value

Claims

1. a base having a vibration exciter; a support portion placed on an upper portion of the base portion; a measuring unit disposed between the base and the support unit and to which a test object is attached; A characteristic measuring device comprising: the support portion includes an intermediate surface plate fixed to the base portion, a reaction force portion functioning as a weight, and an air spring and a fastening mechanism, at least a portion of which is disposed between the intermediate surface plate and the reaction force portion; the fastening mechanism includes, in a fixed state, a first actuator fixed to the intermediate platen and a second actuator fixed to the reaction force portion; a reaction force section that is not supported by the first actuator and the second actuator in a floating mass state, and that is supported by the first actuator and the second actuator in the fixed state.

2. the first actuator includes a first movable part that is movable toward and away from a lower surface of the reaction force part, the second actuator includes a second movable portion that is inserted through the reaction force portion and the first movable portion and has an engaging portion that is detachable from a lower end of the first movable portion; In the floating mass state, an upper end and a lower end of the first movable portion are spaced apart from the reaction portion and the second movable portion in the axial direction, respectively; 2. The characteristics measuring device according to claim 1, wherein in the fixed state, the upper and lower ends of the first movable portion abut against the reaction portion and the second movable portion, respectively.

3. 3. The characteristic measuring device according to claim 1, wherein the reaction force portion is supported only by the first actuator in a temporary fixed state between the floating mass state and the fixed state.

4. the first actuator includes a first movable part that is movable toward and away from a lower surface of the reaction force part, the second actuator includes a second movable portion that is inserted through the reaction force portion and the first movable portion and has an engaging portion that is detachable from a lower end of the first movable portion; 4. The characteristic measuring device according to claim 3, wherein in the temporarily fixed state, an upper end of the first movable part is brought into contact with the reaction part, and a lower end of the first movable part is separated from the second movable part.

5. 5. The characteristic measuring device according to claim 1, further comprising a displacement detector that measures the displacement of the reaction force portion at least in the floating mass state, and a reaction force portion height holding means that controls the pressure supplied to the air spring based on a displacement signal from the displacement detector.

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