Characteristic measuring device

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, durability, etc. under high load of a test object (e.g., anti-vibration rubber or anti-vibration parts) for automobiles, etc. [Background technology]

[0002] In recent years, in addition to vehicles using conventional gasoline engines, hybrid type vehicles that utilize 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 and the like, it is generally necessary to apply a predetermined load (hereinafter referred to as "preload") to the test specimen, simulating the actual vehicle conditions, and then measure the load generated by vibrations (displacement, acceleration, etc.) input from the outside.

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

[0005] [Patent Document 1] JP 2014-006056 A 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 base plate 622 (hereinafter referred to as a "floating mass state") (see Fig. 5(a)), and a state in which the reaction section 624 is fastened and fixed to the intermediate base plate 622 by a fastening mechanism 700 (hereinafter referred to as a "fixed state") (see Fig. 5(b)). As a result, when the input vibration frequency is about 100 to 150 Hz or less, the fixed state is used, and when the input vibration frequency is between 150 Hz and several kHz, the floating mass state is used.

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

[0008] First, when transitioning from a fixed state to a floating mass state (from FIG. 5(b) to FIG. 5(a)), driving oil is supplied to the upper sealed space C1 defined by the cylinder 711 and the top 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. As a result, a restoring force is generated in the compressed air spring 623, and the reaction force portion 624 moves 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)), the movable part 712 moves upward (see the black arrow A2 in FIG. 5(b)) by supplying driving oil to the lower sealed space C2 defined by the cylinder 711 and the lower surface of the upper expanded diameter part 712b, and the lower expanded diameter part 712a engages with the engaging member 720. As a result, the actuator 710 compresses the air spring 623 while moving the reaction part 624 downward until it abuts against the stopper 625 (see the white arrow B2 in FIG. 5(b)).

[0010] In this way, when switching between the floating mass state and the fixed state, the height position of the reaction force part 624 fluctuates with respect to the intermediate surface plate 622. In addition to this, 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)), so air leakage from the air spring 623 to the outside is likely to occur. As a result, the positional fluctuation of the reaction force part 624 occurring when switching from the fixed state to the floating mass state is not reproducible and may not be the same. Such a fluctuation in the position of the reaction force part 624 also fluctuates the distance between the pair of mounting jigs that applied a predetermined preload to the test object, resulting in a problem that the preload on the test object fluctuates significantly (hereinafter referred to as "problem of the prior art (fluctuation of preload)").

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

[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 problems, a characteristic measuring device is provided which comprises a base, a support part placed on top of the base, and a measurement part arranged between the base and the support part and to which a test specimen is attached, wherein the support part comprises an intermediate base plate fixed to the base, a reaction part that functions as a weight, and an air spring and a double fastening mechanism respectively arranged between the intermediate base plate and the reaction part, wherein the air spring and the double fastening mechanism support 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 specimen, and the double fastening mechanism comprises a first actuator fixed to the reaction part and a second actuator fixed to the intermediate base plate, and wherein the reaction part is not supported by the first actuator and the second actuator in the floating mass state, and is 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 is detachable 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 engagement part that is detachable 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 are axially spaced apart 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 abut against 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 part without changing the height of the reaction part in a temporary fixed state between the floating mass state and the fixed state, and the reaction part in the temporary fixed state may be supported only by the first actuator.

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

[0017] Moreover, the above-mentioned 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. Effect 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 description 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 (a) is a front view including a partial cross section, and (b) is a top view. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the double fastening mechanism of FIG. 1. [Diagram 3] 3A to 3C are diagrams illustrating the operating states of the double fastening mechanism in FIG. 2, where (a) shows a floating mass state, (b) shows a provisionally fixed state, and (c) shows a fixed state. [Figure 4] 2 is a diagram illustrating a reaction force portion height holding means in the characteristic measuring device of FIG. 1. [Diagram 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 PREFERRED EMBODIMENTS

[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 the claims, "upper" and "lower" correspond to the upper and lower in Fig. 1(a) and indicate the relative positional relationship of each member, not the absolute positional relationship. The "air spring" in the claims refers to the "support part air spring" in the specification.

[0022] <About the characteristic measuring device> An example of a characteristic measuring device 100 according to an embodiment of the present invention will be described with reference to Fig. 1. Note that the left side of the characteristic measuring device 100 in the figure is shown partially as a cross-sectional view for the purpose of explanation. 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 includes a base 110, a support part 120 that is placed on the upper part of the base 110 and supports a reaction part 124 functioning 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 stand 113 , and an electrodynamic vibration exciter 114 .

[0025] Four legs 111 are arranged at positions in contact with the ground to secure characteristic measuring device 100 to the ground.

[0026] The base air springs 112 are elastic bodies placed on the tops 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] The base mount part 113 is made of a metal such as iron and has a relatively large mass, has a generally square plate shape in a plan view, and has an opening 113a in the center that expands in diameter in a stepped manner toward the bottom. The base mount part 113 is installed via the base air spring 112 so that the upper surface of the base mount part 113 is horizontal.

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

[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. However, this is not limited to the above, and for example, the base 110 may have any form as long as it prevents the transmission of vibrations and can withstand external factors such as earthquakes.

[0030] <About the support> The support portion 120 includes a support column 121, a middle 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, with their lower portions fixed to base mount section 113 and their upper portions fixed to intermediate surface plate 122. In this embodiment, support columns 121 are extendable in the axial direction, and for example, by extending them in the axial direction, it is possible to house measuring section 130 in a thermostatic chamber and measure a large-sized test object 132.

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

[0033] The support part air springs 123 are elastic bodies arranged between the intermediate base plate 122 and the reaction part 124. In a high-frequency vibration state or the like, the support part air springs 123 can be in a floating mass state that blocks transmission of vibrations such as resonance between the base part 110 and the reaction part 124. In this embodiment, for the sake of explanation, eight support part air springs 123 are used, but the present invention is not limited to this, and any other number of support part 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 base 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), which will be described in detail later. In addition, the double fastening mechanism 200 firmly connects the base mount portion 113, the support 121, the intermediate base plate 122, and the reaction force portion 124 in a fixed state, has high rigidity, and can measure the static spring constant of the test object 132 and can measure at a low vibration frequency of about 100 to 150 Hz or less. In this embodiment, for the sake of explanation, four double fastening mechanisms 200 are used, but the present invention is not limited to this, and other numbers of double fastening mechanisms 200 may be used as long as a fixed state having sufficient connection rigidity can be configured. Although details will be described later, the double fastening mechanism 200 of this embodiment can maintain the height position of the reaction force section 124 unchanged via the double fastening mechanism 200 and the support section air spring 123 when switching between the floating mass state, the temporary fixed state, and the fixed state by driving two actuators. 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 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 section 130 includes a pair of mounting jigs 131, a test object 132, a load washer 133, and an electrodynamic vibration table 134.

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

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

[0039] The load washer 133 is disposed above the test object 132 via the upper mounting jig 131a. The load washer 133 is a high-rigidity piezoelectric element with a fast response speed and a small measurement threshold, and therefore constitutes a dynamic load measuring instrument for measuring the dynamic load applied to the test object 132.

[0040] The electrodynamic vibration exciter vibration table 134 is installed on top of 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 magnetic field is disposed 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 thereto and may be, for example, 3 kHz or more.

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

[0042] The main control device controls the characteristic measuring device 100, and is connected to a power source and the characteristic measuring device 100 via an actuator and an operation line. The main control device mainly includes a main servo controller, a charge amplifier, a vibration exciter operation panel, an uninterruptible power supply, a user interface, etc. Signals of dynamic load, displacement, etc. are input to the main servo controller from various sensors of the characteristic measuring device 100, and various measurements and calculations are performed.

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

[0044] <Details of the double fastening mechanism> A detailed configuration of the double fastening mechanism 200 will be described with reference to Fig. 2. Note that the double fastening mechanism 200 in the figure is shown partially in 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 and discharge path 213, a first biasing means 214 that biases the first movable part 212 downward, and a fixing member 215 that is fixed to the lower end of the first movable part 212 and supports the lower side of the first biasing means 214.

[0047] The first cylinder 211 is a hollow cylindrical member fixed to the upper part of the intermediate base plate 122, and has a stepped inner peripheral surface penetrating along the direction of the axis C. On this inner peripheral surface, an upper end small diameter portion 211a, a first piston accommodating portion 211b, a lower guide portion 211c, and a first spring accommodating portion 211d are continuously formed so as to repeatedly reduce and increase in diameter from top to bottom. Also, a recess 122b is formed in the intermediate base plate 122 so as to be continuous with the inner peripheral surface of the first cylinder 211.

[0048] The first movable part 212 is a hollow cylindrical member housed in the first cylinder 211 and the recess 122b of the intermediate platen 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 successively formed so as to increase in diameter from top to bottom, while a step part 212d, a lower shaft part 212e, and a spring abutment part 212f are successively formed so as to decrease in diameter.

[0049] Here, the positional relationship between the first movable part 212 and the first cylinder 211 will be described. First, a gap is formed in the radial direction between the upper shaft part 212b and the upper end small diameter part 211a. Furthermore, a predetermined gap is formed in the radial direction between the step part 212d and the first piston accommodating part 211b, and between the spring abutting part 212f and the first spring accommodating part 211d, respectively, to define the first sealed space S1 and a space 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, to enable relative sliding in the direction of the axis C.

[0050] The first hydraulic supply and discharge path 213 penetrates from the outer peripheral surface to the inner peripheral surface of the first cylinder 211, and can 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 by switching between a connected state allowing supply and discharge or a non-connected state.

[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 the 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 the 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 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 biased downward by the first biasing means 214. Therefore, when the first hydraulic supply / discharge path 213 is in a communicated state in which it can be discharged, 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 sufficient to overcome 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 in contact with 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 and 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 peripheral surface penetrating along the axis C direction, and on this inner peripheral surface, a communication hole 221a, a second spring accommodating part 221b, and a second piston accommodating part 221c are successively formed so that the diameters of the communication hole 221a, the second spring accommodating part 221b, and the second piston accommodating part 221c are successively enlarged from the top to the bottom, and a lower end guide part 221d is reduced in diameter. Also, an insertion hole 124b is formed in the flange 124a of the reaction force part 124, which extends with the same diameter along the axis C direction so as to be continuous with the inner peripheral surface of the second cylinder 221.

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

[0056] Here, the positional relationship between the second movable part 222, the second cylinder 221, the flange part 124a, and the first movable part 212 will be described. First, 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, extremely small gaps are formed to enable relative sliding in the direction of the axis C. Furthermore, between the shaft part 222a and the insertion hole 124b, and between the shaft part 222a and the through hole 212a, gaps are formed in the radial direction.

[0057] The second hydraulic 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 non-connected state, the driving fluid can be supplied, discharged, and maintained in 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 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 biased downward by the second biasing means 224. Therefore, when the second hydraulic supply / discharge path 223 is in a dischargeable communication 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 separated 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 sufficient to overcome 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 engagement portion 222c of the second movable part 222 in a position in contact with the fixed member 215.

[0059] <Operation status of the double fastening mechanism> The operating state of the double fastening mechanism 200 will be described with reference to Fig. 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 provisionally 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 the driving oil in the first sealed space S1 can be discharged via the first hydraulic supply and discharge path 213, so that the first movable part 212 is urged downward by the first urging means 214, and the lower surface of the step part 212d of the first movable part 212 is held in a position where 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 the driving oil in the second sealed space S2 can be discharged via the second hydraulic supply and discharge path 223, so that the second movable part 222 is urged downward by the second urging means 224, and the lower surface of the second piston part 222b of the second movable part 222 is held in a position where 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 engagement 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 supply and discharge path 213 and the second hydraulic supply and discharge path 223 are in a state in which the driving oil can be discharged or in a non-communicating state.

[0062] Next, the double fastening mechanism 200 that transitions from the floating mass state to the provisionally fixed state will be described. As shown in FIG. 3(b), the first actuator 210 is supplied with driving oil through the first hydraulic supply and discharge path 213 to the first sealed space S1 (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 driving oil is stopped at a position where the first movable part 212 abuts against the flange part 124a of the reaction part 124. At this time, the amount of driving oil supplied to the first actuator 210 is controlled so that the first movable part 212 softly lands on the reaction part 124, so that the reaction part 124 does not move upward before and 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 supply / discharge path 213 is in a non-communicating state, while the second hydraulic supply / discharge path 223 is in a state in which the driving oil can be discharged or in a non-communicating state.

[0064] Further, the double fastening mechanism 200 that 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 have the driving oil supplied to the first sealed space S1 through the first hydraulic supply and discharge path 213, so the first movable part 212 does not move. On the other hand, the second actuator 220 has the driving oil supplied to the second sealed space S2 through the second hydraulic supply and 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 the driving oil is stopped at a position where 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 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 and discharge path 213 and the second hydraulic pressure supply and discharge path 223 are in a non-communicating state.

[0066] <When transitioning from fixed state to temporary fixed state to floating mass state> Description that overlaps with the above-mentioned case in which 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, the double fastening mechanism 200 that transitions from the fixed state to the provisionally fixed state will be described. As shown in FIG. 3(c), in the first actuator 210, the first hydraulic supply and discharge path 213 is in a non-communicating state, so the first movable part 212 does not move. On the other hand, the second actuator 220 is in a state in which the driving oil in the second sealed space S2 can be discharged through the second hydraulic supply and discharge path 223 (see arrow d3 in the figure), so 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 driving oil is stopped at a position where the engaging part 222c of the second movable part 222 is separated from the first movable part 212.

[0068] Next, the double fastening mechanism 200 that 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 in a state in which the driving oil in the first sealed space S1 can be discharged via the first hydraulic supply and discharge path 213 (see arrow d4 in the figure), so 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 driving oil is stopped at a position where the first movable part 212 is separated from the flange part 124a of the reaction force part 124.

[0069] Further, the dual fastening mechanism 200 in the floating mass state will be described. As shown in Fig. 3(a), since the driving oil is not 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 part 124 is supported and fixed to the intermediate base plate 122 while maintaining the height position of the reaction force part 124 in the floating mass state, so that when the floating mass state is attained again, the reaction force part 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 (see reference height h0 in FIG. 3) of the reaction force portion 124 unchanged via the double fastening mechanism 200 and the support air spring 123 when switching between the floating mass state, the provisionally fixed state, and the fixed state by driving the first actuator 210 and the second actuator 220. This eliminates the conventional problem (variation of preload) and enables smooth switching between the floating mass state and the fixed state. In addition, since the vertical compression force applied to the support air spring 123 of this embodiment does not change in the floating mass state, the provisionally fixed state, and the fixed state, it is possible to suppress the internal pressure of the support air spring 123 from suddenly increasing and causing air leakage when switching between each state. Furthermore, unlike the conventional fastening mechanism 700 (see FIG. 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 the fixed state, the temporary fixed state, to the 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 part> As described above, in the characteristic measuring device 100 of this embodiment, the double fastening mechanism 200 is adopted instead of the conventional fastening mechanism 700 (see Figs. 5(a) and 5(b)), thereby eliminating the conventional problem (preload fluctuation) without changing the height position of the reaction force part 124, and it is possible to sufficiently smoothly switch between the floating mass state and the fixed state. In addition, the inventors further considered the vertical behavior of the reaction force part 124 when the double fastening mechanism 200 is adopted. As a result, they found 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 part 124 may change slightly below the desired reference height h0, and that this is due to the airtightness of the support part air spring 123. Specifically, when in a fixed state, the support part 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 part air spring 123 supports the reaction part 124 alone.

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

[0074] The 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 the 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 thereof a pressure supply source 320 that supplies high-pressure (0.4 MPa or more) compressed air and a silencer 330 that silences and exhausts the air to the external environment, and to the other side thereof a support air spring 123.

[0076] The displacement detector 340 is a wire-type displacement meter including a wire portion 340a. The upper end of the 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 that 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 (for example, a laser-type displacement meter) may be used.

[0077] The PID control unit 350 is a combination of proportional control, integral control, and differential control, and calculates a control value u from three elements, namely, the error e between the displacement position H1 and the target position Hr, and its integral and differential, to control the supply pressure PS. By controlling the supply pressure PS using this PID control unit 350, it is possible to make the displacement position H1 of the reaction force portion 124 stably and quickly reach the target position Hr while suppressing overshooting.

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

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

[0080] In this way, the reaction force section height retaining 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 retaining 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, for example, at all times (floating mass state, temporary fixed state, and fixed state).

[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 fixtures 131a Upper mounting fixture 131b Lower mounting fixture 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 Movable 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 exhaust line 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 receiving part 222c Engagement part 223 Second hydraulic supply and exhaust 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 measurement unit disposed between the base and the support unit and to which a test object is attached; A characteristic measuring apparatus comprising: The support portion includes an intermediate base plate fixed to the base, a reaction portion functioning as a weight, and an air spring and fastening mechanism at least a portion of which is disposed between the intermediate base plate and the reaction 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 portion, a reaction force portion 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 portion that is movable toward and away from a lower surface of the reaction portion, the second actuator includes a second movable portion having an engagement portion that is inserted through the reaction portion and the first movable portion and 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 characteristic measuring device according to claim 1, wherein in the fixed state, an upper end and a lower end of the first movable portion are in contact with 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 provisional fixed state between the floating mass state and the fixed state.

4. the first actuator includes a first movable portion that is movable toward and away from a lower surface of the reaction portion, the second actuator includes a second movable portion having an engagement portion that is inserted through the reaction portion and the first movable portion and 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 abutted against 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 a 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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