Vibration test device

Abstract

To provide a vibration test device of a linear motor system which applies a sufficient vibration on a test piece with a large weight.SOLUTION: A vibration test device 10 is a device which has a linear motor 20 for moving a movable element 21 forward and backward in a linear direction and applies vibrations of a linear direction on a test piece C. More than one liner motor are set to move its corresponding movable element forward and backward in parallel and vibrate a supporting member 11 for supporting a test piece. The supporting member has an air spring mechanism 40 having a moving plate 41, which moves in parallel to the direction of moving the movable elements of the linear motors, and adding an elastic force.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vibration test device that applies vibration to a test specimen. [Background technology]

[0002] Vibration test equipment that forcibly applies vibrations to evaluate the durability and performance of various components and equipment that are subjected to vibrations is known, and hydraulic equipment is often used in this type of vibration test equipment to vibrate heavy test specimens. However, hydraulic vibration test equipment requires a large hydraulic source, consumes high energy, and has high maintenance costs. In addition, hydraulic control valves have poor output characteristics for high-frequency (40 Hz or higher) acceleration and do not move as commanded, so processing to expand or reduce the command signal is required, which is time-consuming. For this reason, in recent years, devices that use linear motors (actuators) that move in a straight line have been considered (for example, Patent Documents 1 and 2). This linear motor vibration testing device requires no electricity except when in operation, so it is expected to reduce energy consumption, and maintenance such as changing lubricating oil or disassembling and cleaning hydraulic valves is not required, making it simple and easy to use. Furthermore, it operates according to commands for acceleration vibrations of relatively high frequencies up to about 100 Hz, so tests can be carried out without signal processing time. Another advantage is that there is little time delay in response to commands (less than a fraction of that of hydraulic pressure), and it has good response to changes in command values ​​in real time during tests simulating operating conditions, making it easy to use. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5466031 [Patent Document 2] Patent No. 4885222 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such a linear motor vibration test device, the driving force of the linear motor is smaller than that of a hydraulic actuator of a similar size. For this reason, the output driving force is insufficient to support a test specimen that requires a large driving force, for example, a shock absorber that is attached to a wheel to ensure the running quality of a vehicle and reduces the behavior (vibration) of the wheel, and a vibration test to evaluate the durability and performance of the shock absorber is performed. In addition, if the output driving force is small, it is also impossible to apply a large acceleration vibration to the test specimen during the vibration test.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a linear motor type vibration testing device capable of applying sufficient vibration even to a heavy test piece. [Means for solving the problem]

[0006] One aspect of the invention of a linear motor type vibration test device that solves the above problems is a vibration test device that is equipped with a linear motor that moves a movable element back and forth in a linear direction to apply linear vibration to a test specimen, and is characterized in that a plurality of the linear motors are installed so that their respective movable elements can move back and forth in parallel directions to vibrate a support member that supports the test specimen. Effect of the Invention

[0007] Thus, according to one aspect of the present invention, a linear motor type vibration testing device can be provided that can vibrate the support member supporting the test specimen using the driving force of multiple linear motors, thereby applying sufficient vibration even to heavy test specimens. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a front view showing a schematic overall configuration of an automobile vibration test system equipped with a linear motor type vibration test device according to one embodiment of the present invention. [Diagram 2]FIG. 2 is a conceptual structural diagram showing a schematic overall configuration of a linear motor type vibration test device. [Diagram 3] FIG. 3 is a diagram showing the structure of one linear motor, where (a) is an enlarged vertical cross-sectional view of an upper part as seen from the same direction as in FIG. 2, and (b) is a schematic diagram showing the magnet configuration of the mover. [Figure 4] FIG. 4 is a cross-sectional view of one linear motor. [Diagram 5] FIG. 5 is a conceptual block diagram illustrating the control of the vibration testing system. [Figure 6] FIG. 6 is a vertical cross-sectional view showing a state of one linear motor before preparation for testing. [Figure 7] FIG. 7 is a vertical cross-sectional view showing a state in which one linear motor is being prepared. [Figure 8] FIG. 8 is a vertical cross-sectional view showing a state in which one linear motor is being tested. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figures 1 to 8 are diagrams showing a linear motor type vibration test device according to one embodiment of the present invention.

[0010] In Fig. 1, the vibration test device 10 is assembled to a vibration test system 100 for an automobile C (specimen) C, which performs evaluation tests such as durability and vibration-damping performance by applying vibration to each of the four wheels W of the automobile C (specimen) C in a vertical direction V (reciprocating in a linear direction), and the vibration test system 100 is constructed so that a vibration test can be performed while the automobile C, which is supported so that each of the four wheels W cannot rotate, is placed in a stationary state on an adjustment plate 101. Here, in this vibration test system 100, the vibration test device 10 for each of the four wheels W is arranged in a space 103 dug in the ground surface (height) on which the automobile C runs, and the vibration test device 10 is installed below an adjustment plate 101 that is prepared to stop each of the four wheels W from rotating. The adjustment plate 101 is equipped with a mechanism (not shown) that adjusts the position of the automobile C in the forward and backward directions and in the left and right directions at ground level.

[0011] Four sets of the vibration test apparatus 10 are mounted on the vibration test system 100 so as to function positioned under adjustment plates 101 for each of the four wheels W of the automobile C, and the same or individual vibration is applied to each of the four wheels W to reproduce the behavior received from the road surface during driving, and the desired driving force is output through vibration control by a control system (control device) 50 described below. Here, the control system 50 may be prepared for each of the four sets of vibration test apparatus 10 and set and control them individually, but in this embodiment, it is configured so as to centrally control the four sets of vibration test apparatus 10 and drive them equally or separately to perform vibration tests.

[0012] 2, the vibration test device 10 has two linear motors (actuators) 20 and one air spring mechanism 40 housed integrally in a housing 10F. In this vibration test device 10, the support members 11 connected and fixed under the adjustment plates 101 for each of the four wheels W of the vibration test system 100 are connected to one end of the movers 21 of the plate-like members of the two linear motors 20 and the moving plate 41 of the plate-like member of the one air spring mechanism 40, respectively, and are integrated, and the movers 21 of the linear motors 20 and the moving plate 41 of the air spring mechanism 40 move up and down (reciprocate) in a linear vertical direction V to apply vibration to the four wheels W of the automobile C on the adjustment plate 101. That is, one end of each of the movers 21 of the linear motors 20 and the moving plate 41 of the air spring mechanism 40 is connected and fixed to a common support member 11, and reciprocates vertically and in parallel directions to vibrate the wheels W (shock absorbers) of the automobile C under test, thereby enabling a vibration test to be performed. The vibration test device 10 is positioned and fixed by connecting a base member 10Fb at the bottom of the housing 10F to a base within the installation space 103 of the vibration test system 100.

[0013] The linear motors 20 are disposed at symmetrical positions sandwiching the air spring mechanism 40, and the pair of movers 21 move up and down simultaneously (synchronously) to apply two sets of driving forces to the support member 11, thereby applying vibration to the four wheels W of the automobile C on the adjustment plate 101, thereby performing a vibration test of a shock absorber (not shown). Here, in this embodiment, the vibration test device 10 equipped with two sets of linear motors 20 will be described as an example, but it goes without saying that it is not limited to two sets, and may be equipped with three or more sets.

[0014] Specifically, as shown in Figures 3 and 4, the linear motor 20 is assembled in the form of a rectangular parallelepiped with the wall portions 10Fw of the housing 10F positioned opposite the plate-shaped movers 21 and the legs 10Ff sandwiched between the wall portions 10Fw, and a pair of stators 31 are fixed to the inner surface of the wall portions 10Fw so as to face each of the plate-shaped movers 21 which move up and down while facing each other.

[0015] The mover 21 of the linear motor 20 has a yoke 23 made of a plate-shaped iron member that passes magnetic flux so as to receive power (magnetic force) to move up and down while facing a stator 31 installed on the inner side of the wall 10Fw of the housing 10F, and magnets 25 are arranged such that positive and negative poles are alternately positioned at the portions of the yoke 23 facing the stator 31. The stator 31 of the linear motor 20 also has a coil (not shown) arranged therein so that it is supplied with power from a power source to load a magnetic force that moves the mover 21 back and forth.

[0016] The movable member 21 of this linear motor 20 is supported by a pair of end edge rollers 33 rotatably supported on the leg portions 10Ff of the housing 10F, one of which is supported in face-to-face contact with both end edges 21e of the plate-shaped member in the width direction S so as to be movable up and down.Similarly, two sets of end surface rollers 35 rotatably supported on the wall portions 10Fw of the housing 10F are supported by two sets of end surface rollers 35 rotatably supported on the wall portions 10Fw of the housing 10F, each of which is supported in face-to-face contact with both ends 21s of the plate-shaped member in the width direction S so as to be movable up and down.

[0017] In addition, in the mover 21 of the linear motor 20, magnets 25a (e.g., N pole) and magnets 25b (e.g., S pole) are arranged so that the magnetic poles (S pole, N pole) alternate in the up-down direction V of the yoke 23 and the magnetic poles are also reversed on both sides in the thickness direction T of the yoke 23. Note that the yoke 23 of the mover 21 has backing plates 39a fixed to both end edges 21e in the width direction S with which the end side rollers 33 rotatably contact, and backing plates 39b fixed to both end sides 21s in the width direction S with which the end face rollers 35 rotatably contact, thereby ensuring durability, but these may be omitted and the various rollers 33, 35 may be directly supported by contacting the yoke 23 face-to-face.

[0018] Here, by adopting such a configuration for the mover 21 of the linear motor 20, the magnet 25 can be arranged without considering magnetic pole saturation caused by the magnet 25, and the thickness of the yoke 23 in the thickness direction T can be minimized. Furthermore, the mass of the mover 21 can be reduced, and the output acceleration and responsiveness of the vibration operation can be improved. Note that since the mover 21 does not include the weight of the stator 31 and rollers 33 and 35 on the housing 10F side, there is no need to unnecessarily increase the magnetic force (output) when moving up and down, and it is possible to avoid a decrease in acceleration and a decrease in lifespan due to weight.

[0019] Returning to FIG. 2, the air spring mechanism 40 is housed within the housing 10F so as to be positioned between the two sets of linear motors 20, and the moving plate 41 of the air spring mechanism 40, like the plate-shaped movable element 21 of the linear motor 20, is supported by two sets of pairs of rollers 43, 45 located above and below and installed freely rotatable, in face-to-face contact on both side surfaces 41s, respectively, so as to be freely movable up and down.

[0020] The movable plate 41 of the air spring mechanism 40 is formed in a hollow plate shape having an internal space 41a and an opposite end 41e opposite to the support member 11, and a plate-shaped rib 41r is formed on the opposite end 41e of the support member 11, protruding outward in a perpendicular direction from both side surfaces 41s.

[0021] The air spring mechanism 40 includes a damper 47 disposed between the walls 10Fw of the housing 10F on both sides so as to cover the entire end 41e having the plate-shaped rib 41r of the moving plate 41, and the damper 47 is in contact with the end edge 43re of the plate-shaped rib 41r of the moving plate 41 so as to be movable up and down while maintaining airtightness. The damper 47 of the air spring mechanism 40 has an internal space 47a that communicates with the internal space 41a via an opening 41o between the plate-shaped ribs 41r of the moving plate 41, and a valve 47v that fills (encloses) the internal spaces 47a, 41a with the outside air A at a desired pressure and maintains (seals) the internal spaces 47a, 41a in a closed state is disposed at a bottom 47b.

[0022] With this structure, the air spring mechanism 40 can urge the moving plate 41 upward, that is, in a direction parallel to the moving direction of the mover 21 of the linear motor 20, as an elastic force by filling a desired amount of external air A from a pressure source P (shown in FIG. 5) into the internal space 47a and the internal space 41a of the moving plate 41 via the valve 47v of the damper 47, and functions as an elasticity adding mechanism that supports the support member 11 together with the pair of linear motors 20. The air pressure of the air spring mechanism 40 can be adjusted by adjusting the amount of external air A filled in the damper 47 and the internal spaces 47a and 41a of the moving plate 41 using the valve 47v, and the elastic force (air pressure) applied to the support member 11 can be adjusted according to the weight of the test specimen.

[0023] As shown in FIG. 5, the vibration test device 10 is configured to detect the behavior of the support member 11 by detecting the up and down movements of each of the movers 21 of the pair of linear motors 20 using a high-resolution encoder 57 installed on the wall portion 10Fw of the housing 10F on the stator 31 side, and is configured so that the drive of the pair of linear motors 20 and the air spring mechanism 40 is controlled by a control system (control unit) 50 based on the detection information (signal) of each encoder 57.

[0024] The control system 50 is constructed so that a host control device 51, an air tandem controller 53, and a pair of motor drivers 55A, 55B are connected so as to be able to exchange various signals and operate in coordination, and the host control device 51 passes drive signals to the controller 53 and the motor drivers 55A, 55B so as to centrally control the entire vibration test apparatus 10, causing the motor drivers 55A, 55B to send drive power to the stator 31 of the linear motor 20 to move the mover 21 up and down, and also opens and closes a valve 47v in the damper 47 of the air spring mechanism 40 to supply compressed air A from the pressure source P and adjust the amount of air filled into the internal spaces 41a, 47a of the moving plate 41 and the damper 47, thereby adjusting the elastic force that urges the moving plate 41 upward.

[0025] Specifically, in order to carry out a vibration test of a test specimen (automobile) C based on various setting input information in accordance with a control program previously stored in a memory not shown, the upper control device 51 acquires displacement information of the mover 21 (support member 11) from an encoder 57 via motor drivers 55A, 55B to derive vibration conditions, and sends instruction information according to the vibration conditions to the motor drivers 55A, 55B to supply a driving current to the stator 31 of each linear motor 20.

[0026] This higher-level control device 51 is configured to send instruction information corresponding to the support conditions of the test specimen C to the controller 53 based on displacement information from the encoder 57 acquired via the motor drivers 55A, 55B, so that a vibration test of the test specimen C can be performed in accordance with the above control program, and to supply a driving current that adjusts and controls the opening and closing of the valve 47v of the damper 47 of the air spring mechanism 40.

[0027] Here, the signal commands used in the above-mentioned sections 51, 53, 55A, and 55B of the control system 50 may be either analog signals or digital signals, and may be selected taking into consideration the effects of noise, etc., and in this control system 50, the wiring lengths of the signal lines and power supply lines of a pair of motor drivers 55A, 55B and encoder 57, which are driven with similar functions, are made equal and arranged so that various conditions (signal strength, timing, etc.) are equalized.

[0028] The air tandem controller 53, like the upper control device 51, executes drive control to generate pressure in the air spring mechanism 40 to hold the automobile C at a desired height so that a vibration test can be performed on the specimen C according to a control program previously stored in a memory (not shown). At this time, the controller 53 supplies a drive current that controls the opening and closing of the valve 47v so that the damper 47 and the internal spaces 47a, 41a of the moving plate 41 of the air spring mechanism 40 are filled with compressed air A from the pressure source P so that the air pressure is such that the elastic force is exerted to support the specimen C at a height that can ensure the amplitude during the vibration test independently without cooperating with the drive force of the pair of linear motors 20.

[0029] In detail, the controller 53 of this embodiment monitors the driving force (driving current supplied to the stator 31) output by the pair of linear motors 20 by the motor drivers 55A, 55B, and controls the opening and closing of the valve 47v of the damper 47 of the air spring mechanism 40 so that the load as thrust becomes zero, and closes the valve 47v at the timing when the test piece C is supported independently to maintain the supporting state. In short, the air pressure (elastic force) of the air spring mechanism 40 is made large enough to make the driving force of the linear motor 20 zero, and a large air pressure is secured to the extent that the vibration of the vibration test by the linear motor 20 can be suppressed from fluctuating the air pressure of the air spring mechanism 40, thereby preventing large fluctuations in the air pressure from becoming a disturbance in the vibration test.

[0030] Here, when the vibration test device 10 is used as a vibration test device for shock absorbers of the wheels W of an automobile C, when the four wheels of the automobile C are placed on or removed from the adjustment plate 101, a switch is provided to display preparation, waiting, or testing so that the vibration operation is not started inadvertently, and the vibration test by the pair of linear motors 20 will not start unless the controller 53 detects that the air spring mechanism 40 is supporting the specimen C alone, and the vibration test of the specimen C is started by turning on the test start switch.

[0031] In short, as shown in FIG. 6, before the wheels W (four wheels) of the automobile C are prepared to be placed on the adjustment plate 101, the vibration test device 10 has the internal space 47a at the minimum volume V1 without supplying compressed air A into the damper 47 of the air spring mechanism 40, and the bottom ends of the movable members 21 of the pair of linear motors 20 enter the escape grooves 29 opening into the base member 10Fb of the housing 10F to position the support member 11 at the pre-preparation height.

[0032] 7, in the vibration test device 10, during preparation for holding the wheels W (four wheels) of the automobile C placed on the adjustment plate 101 at the vibration test height, the host control device 51 and the controller 53 supply compressed air A from the pressure source P into the damper 47 of the air spring mechanism 40 so that the internal space 47a becomes the test volume V2, and the displacement of the mover 21 is grasped based on the detection signal from the encoder 57, and the valve 47v is controlled to open and close, thereby positioning the support member 11 at the preparation / pre-test (during test) height. At this time, the host control device 51 may supply power to the stators 31 of the pair of linear motors 20 to drive the mover 21, thereby assisting the rise of the specimen C. In this case, after the support member 11 is held at the preparation height, the power supply to the stators 31 of the pair of linear motors 20 is gradually reduced to zero the lift load of the specimen C caused by the mover 21.

[0033] After that, as shown in Fig. 8, in the vibration test device 10, during a test in which the wheels W (four wheels) of the automobile C placed on the adjustment plate 101 are held at the vibration test height, the controller 53 maintains the valve 47v of the damper 47 in a closed state in order to maintain the holding of the specimen C at the test height by the air spring mechanism 40, and the host control device 51 executes the supply of current to the stators 31 of each pair of linear motors 20 by the motor drivers 55A and 55B based on the displacement information from the encoder 57 to perform the vibration test of the specimen C. Note that Fig. 8 illustrates the timing during a test in which an upward acceleration is applied to the support member 11 to load a shock to the wheels W of the automobile C on the adjustment plate 101 to overcome an obstacle, and the movable element 21 of the linear motor 20 rises and the moving plate 41 of the air spring mechanism 40 is pulled up, so that the internal space 47a of the damper 47 reaches the maximum volume V3 and the air pressure also drops.

[0034] At this time, the vibration test device 10 adjusts and controls the power supply to the stator 31 so as to uniformly move up and down the movable elements 21 of each pair of linear motors 20 and maintain the horizontal state of the adjustment plate 101, and furthermore, is also capable of changing the vibration conditions for each of the wheels W (four wheels) of the automobile C.

[0035] Therefore, by providing a pair (multiple) of linear motors 20 as necessary, the vibration test device 10 does not need to prepare linear motors with unnecessarily large driving force, and conversely, it is possible to avoid a situation in which vibration cannot be applied at the desired acceleration due to insufficient driving force. Also, by providing the air spring mechanism 40 that can easily and simply adjust the air pressure and ensures stable air pressure, the vibration test device 10 can reduce the driving force required for the linear motor 20, and further, by supporting the test specimen C with the air spring mechanism 40 without requiring the driving force of the linear motor 20 before vibration, the driving force required for the linear motor 20 can be further reduced.

[0036] In this way, in the vibration test device 10 of this embodiment, a vibration test can be performed in which the test specimen automobile C is supported by the air pressure of the air spring mechanism 40 while the wheels W of the automobile C are vibrated by the driving force of a pair of linear motors 20, and each wheel W of the heavy automobile C can be vibrated with sufficient acceleration.

[0037] The scope of the present invention is not limited to the exemplary embodiments shown and described, but includes all embodiments that achieve equivalent effects to the object of the present invention. Moreover, the scope of the present invention is not limited to the combination of inventive features specified in each claim, but may be defined by any desired combination of each and every particular feature disclosed. [Explanation of symbols]

[0038] 10...Vibration test equipment 10F... Cabinet 11...Support member 20...Linear motor 21……Movable element 23...York 25...Magnet 31……Stator 40...Air spring mechanism 41...Moving plate 41a……Internal space 47...Damper 47a……Internal space 47v...valve 50...Control system 51... Upper control device 53...Controller 55A, 55B...Motor driver 57...Encoder 100...Vibration test system A... External air (compressed air) C...Automobile (specimen) W...Wheel

Claims

1. A vibration test device that applies linear vibration to a test piece by using a linear motor that reciprocates a movable element in a linear direction, A vibration test device characterized in that a plurality of the linear motors are installed so that their respective movers can reciprocate in parallel directions to vibrate a support member that supports the test piece.

2. 2. The vibration test device according to claim 1, wherein each of the movers of the linear motors is connected to a common support member.

3. 2. The vibration test device according to claim 1, wherein the support member includes an elasticity applying mechanism that applies an elastic force to move the linear motors in a direction parallel to a moving direction of the movers of the linear motors.

4. 4. The vibration test device according to claim 3, further comprising an air spring mechanism as the elasticity adding mechanism.

5. 5. The vibration test device according to claim 4, wherein the air spring mechanism has a structure that makes it possible to adjust the air pressure that applies the elastic force.

6. 5. The vibration testing device according to claim 4, wherein the air spring mechanism has a capacity sufficient to suppress fluctuations in air pressure caused by the vibration operation of the support member by the multiple linear motors, as the enclosed air that generates the air pressure that applies the elastic force.

7. 2. The vibration test device according to claim 1, further comprising a control unit that executes a control operation for each of the plurality of movers of the linear motor so as to apply the same vibration operation to the support member.

8. 8. A vibration test system comprising a plurality of vibration test apparatuses according to claim 1 arranged under a test specimen, the vibration test apparatuses being configured to perform a vibration test on the test specimen.

9. 9. An automobile shock absorber testing device, comprising: a vibration test system according to claim 8, and a plurality of vibration test devices arranged under the wheels of an automobile to perform a performance test of the shock absorbers of the automobile.

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