JPS6214767B2 - - Google Patents

Description

Detailed Description of the Invention The present invention fixes one end of a specimen of various dimensions to a certain coordinate body, and the other end contacts or is fixed to the end of the excitation shaft (excitation end) of a vibration generator. The present invention also relates to a vibration test method in which a predetermined dynamic deflection or dynamic load is applied to the specimen while a predetermined static deflection or static load is applied to the specimen.

Generally, a vibration generator generates a predetermined force between the outer container body and a movable part (excitation shaft) using electromagnetic force or hydraulic pressure, and is used with the outer container body fixed to the foundation. be done. In this case, the reaction force is transmitted to the foundation, vibrates the foundation, causes the fixed end of the specimen to vibrate, and affects the specimen, the displacement sensor, and the load sensor. Therefore, a method is used in which the outer container body is provided with air springs to provide vibration isolation to reduce vibrations at the fixed end of the specimen. In this method, when a predetermined static deflection or static load is applied to the specimen, the relative distance between the vibration generator's excitation axis and the outer container body becomes larger than the predetermined static deflection due to the reaction force. The position of the outer container body of the vibration generator must be adjusted by adjusting the internal pressure of the air spring so that the displacement does not exceed the maximum displacement of the vibration generator.

However, this adjustment operation has to be repeated many times when the predetermined static deflection is large and the maximum displacement of the vibration generator is small.
Furthermore, when using a displacement sensor with excellent measurement resolution for measuring dynamic deflection, it is necessary to use a sensor with an effective stroke smaller than the maximum variation of the vibration generator, making the above situation even worse. was.

The present invention focuses on such conventional problems and aims to solve them. That is, the present invention
Even when using a displacement sensor with a small effective stroke, it is possible to apply a relatively large static deflection to specimens of various sizes, and the internal pressure of the air spring can be adjusted only once. The purpose is to make it possible.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

In FIG. 1 or 2, 1 is an electrodynamic or hydraulic type vibration generator. The vibration generator 1 itself is one that has been well known in Japan since before 1955, and is used as is. For example, JP-A-1983-
As illustrated in Publication No. 31466, etc., an excitation shaft is inserted inside the outer container body, and this excitation shaft is controlled by an excitation coil with a constant voltage and a drive coil through which a variable control current is passed. Excitation is a completely known technique. Moreover, by passing a predetermined current through the internal drive coil, the protruding length of the excitation shaft - that is, the distance that the excitation end of the excitation shaft protrudes from the outer container body - can be arbitrarily selected. It is also well known that

In the embodiment shown in FIG. 1, such a conventionally known vibration generator 1 is used as is in a horizontal configuration. However, in order to horizontally support the entire vibration generator 1, in this embodiment, a guide cylinder 5 is provided protruding from the outer peripheral surface of the outer container body 6.
Furthermore, a frame 3 is used. That is, to explain in detail, a frame 3 is fixed and erected on a stationary coordinate body 2 such as a floor or a base, and arrows A, B are attached to guide shafts 4 arranged in the horizontal direction of the frame 3. A guide cylinder 5 is fitted onto the outer circumferential surface of the outer container body 6 of the vibration generator 1 so as to be slidable in the direction.
By protruding the outer container body 6, the frame body 3
It is supported so as to be movable in the horizontal directions A and B along the guide shafts 4 . In addition, protruding pieces 7, 7 are provided to protrude from the outer peripheral surface of the outer container body 6 to the left and right sides, and air springs 8 are interposed between the outer container body 6 and the frame body 3,
The pressure of the air spring 8 causes the outer container body 6 to move in the direction of arrows A and B.
It is movable in the direction and resiliently held in a neutral position.

Reference numeral 9 denotes a vibration shaft of the vibration generator 1, which projects horizontally from the outer container body 6. Reference numeral 10 is a specimen, which is a fixed base 1 of a coordinate body 11 on the left side of the figure.
One end of the specimen 10 is fixed to the fixed end 13 of No. 2. Further, the other end of the specimen 10 is in contact with or fixed to the excitation end 14 of the excitation shaft 9.

15 is a position sensor for detecting the position of the outer container body 6 in the directions of arrows A and B with respect to the stationary coordinate body 2; the position sensor 15 includes a position sensor head 16 attached to the outer container body 6; A position sensor scale 17 is correspondingly fixed to the stationary coordinate body 2.

Thus, in FIG. 1, the movable rod 18 is provided in a protruding manner from the left end surface of the outer container body 6, and the fixed rod 20 is provided in a protruding manner from the fixed base 19 of the stationary coordinate body 2, The movable rod 18 and the fixed rod 20 are arranged close to each other and parallel to each other. 21 is the guide arm,
A displacement sensor 22 is attached to the tip of the guide arm 21, and the guide arm 21 is detachably fixed to the movable rod 18 via an attachment/detachment mechanism 23, and is also detachably attached to the fixed rod 20 via an attachment/detachment mechanism 24. is fixed to. Specifically, a pair of electromagnets that can be attached to and detached from the rods 18 and 20 alternately are attached to the guide arm 21 to form attachment and detachment mechanisms 23 and 24. In this way, it can be operated more automatically. It should be noted that each of the attachment/detachment mechanisms 23 and 24 may be composed of a boss portion having a hole that is slidably inserted into the rod 18 or the rod 20, and a thumbscrew that can be screwed forward and backward into the screw hole of the boss portion. preferable. Further, a displacement sensor target 25 is attached to the excitation end 14 in a protruding manner and corresponds to the displacement sensor 22.

In this way, the attachment/detachment mechanisms 23 and 24 allow the outer container body 6 and the stationary coordinate body 2 to be alternately attached and detached.
A displacement sensor 22 is provided. Next, the displacement sensor 2
2 is fixed to the outer container body 6 by an attachment/detachment mechanism 23, and the position of the excitation end 14 with respect to the outer container body 6 is detected by the displacement sensor 22. As is well known in the art, by increasing or decreasing the current flowing through the drive coil inside the outer container body 6, the protruding length of the excitation shaft 9 - that is, the distance C of the excitation end 14 with respect to the outer container body 6 can be adjusted.
- can be controlled. Therefore, the displacement sensor 22
If the current flowing through the drive coil is controlled using the detector as the detector, it is possible to easily maintain the distance C of the excitation end 14 at a desired value. Therefore,
Through servo control using the displacement sensor 22 as a detection unit, the distance C of the excitation end 14 with respect to the outer container body 6 is kept constant until the position of the outer container body 6 with respect to the stationary coordinate body 2 reaches the command value. The excitation end 14 is positioned by increasing or decreasing the pressure (internal pressure) of the air springs 8 that support the vibration generator 1. Alternatively, by servo control using the displacement sensor 22 as a detection part, the air springs 8... The excitation end 14 is positioned by increasing or decreasing the pressure.

That is, as shown in the air spring pressure increase/decrease control system diagram in FIG. teeth,
Each air spring 8 in the direction of decreasing position or load.
Adjust the pressure. When the signal is too small c, the reverse is done. When the coincidence signal a is output, the positioning operation of the excitation end 14 is completed.

After the operation is completed, the displacement sensor 22 is attached to the movable rod 18 of the outer container body 6 by the attachment/detachment mechanisms 23 and 24.
It is detached from the stationary coordinate body 2 and fixed to the fixed rod 20 of the stationary coordinate body 2. If the displacement sensor 22 is fixed to the stationary coordinate body 2 in this way, the displacement sensor 22 can be used as a detection part,
Servo control in which the position of the excitation end 14 with respect to the stationary coordinate body 2 is the controlled variable is configured as shown in FIG.
Vibration is applied to the specimen 10.

In the servo control system diagram shown in Fig. 2, i is the vibration command input, 26 is the vibration command permission switch, and when this is turned on, the servo
7. The signal is sent to the actuator or drive coil of the vibration generator 1 through the servo valve or power amplifier 28 in order, and the vibration shaft 9 is excited. Displacement sensor 2
2 and load sensor 29 are connected in parallel on the system diagram,
Selector switch 30 selects either sensor 22,
29 is selected and the detected amount is fed back.

Next, in FIG. 4, the position of the outer container body 6 of the vibration generator 1 with respect to the stationary coordinate body 2 is similarly detected by the position sensor 15. A displacement sensor 22 facing a target 25 attached to the excitation end 14 is attached to the tip of the holding member 31, and on the other hand, a control motor such as a servo motor or a pulse motor is mounted on a fixed base 19 fixed to the stationary coordinate body 2. 32 is provided, and the base portion of the holding member 31 is attached to the control motor 32 to reciprocate in the directions of arrows D and E, thereby making it possible to adjust the position of the displacement sensor 22.

In this way, the displacement sensor 2 is reciprocated in a direction parallel to the vibration axis 9 with the stationary coordinate body 2 as a reference.
Open loop control as shown in FIG. 5 is configured in which the position of 2 is detected, the position is used as the control amount, and the output of the position sensor 15 is used as the reference input, or closed loop control as shown in FIG. 6 is configured. do.

FIG. 5 shows a system diagram of open loop control in which the reference input from the position sensor 15 is sent to the pulse motor drive circuit 33 and its output is input to the control motor 32 such as a pulse motor. In addition, in FIG. 6, a closed loop is shown in which the reference input from the position sensor 15 is amplified by a servo amplifier 34, the output thereof is input to a control motor 32 such as a servo motor, and then passed through an encoder 35 for feedback. A control system diagram is shown.

Through such open-loop or closed-loop control, the position of the displacement sensor 22 with respect to the stationary coordinate body 2 is made to follow the position of the outer container body 6 with respect to the stationary coordinate body 2, and at the same time, the displacement sensor 22 is used as a detection unit and vibration While the position of the excitation end 14 with respect to the displacement sensor 22 is kept constant by servo control using the generator 1 as the operating unit, the position of the outer container body 6 with respect to the stationary coordinate body 2 or the load applied to the specimen 10 is set to the command value. The excitation end is positioned by increasing or decreasing the pressure of the air spring 8 (as shown in FIG. 3) until the excitation end is reached.

After that, the follow-up control of the displacement sensor 22 is canceled,
The displacement sensor 22 is fixed to the stationary coordinate body 2. That is, the motor 32 is kept in a stopped state. While maintaining this state, as shown in FIG. 2, an excitation command input i is input, the displacement sensor 22 is used as a detection part, and servo control is performed using the position of the excitation end 14 with respect to the stationary coordinate body 2 as a control amount. and test specimen 1
Various tests are performed by adding vibration to 0.

It should be noted that the present invention is not limited to the above-described embodiments, and is of course open to various design changes. It is also possible to mount the vibration generator 1 facing downward. moreover,
A certain coordinate body 11 may be the same object as the stationary coordinate body 2 or may be integrally connected, but it is also preferable that the coordinate body 11 be an object movable in a direction parallel to the vibration axis 9 by a drive source not shown. Furthermore, it is also possible to move a certain coordinate body 11 in one direction or in multiple axial directions other than the axial direction of the excitation shaft 9, but in that case, the spherical coupling or the plane coupling What is necessary is just to interpose it between and the excitation end 14.

The present invention effectively achieves the intended purpose with the configuration described in detail above, and even when the maximum allowable displacement between the excitation shaft of the vibration generator and the outer container body is small,
The internal pressure of the air spring only needs to be adjusted once and can be set quickly. In addition, it has become possible to use a displacement sensor with a small effective stroke and excellent measurement resolution for specimens of various sizes and specimens to which a large static deflection is to be applied.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the present invention, Fig. 2 is a servo control system diagram, Fig. 3 is an air spring pressure adjustment control system diagram, and Fig. 4 is a side view showing an embodiment of another invention. FIG. 5 is an open loop control system diagram, and FIG. 6 is a closed loop control system diagram. 1... Vibration generator, 2... Stationary coordinate body, 6...
Outer container body, 8... Air spring, 9... Vibration axis, 10
... Specimen, 14 ... Excitation end, 15 ... Position sensor, 22 ... Displacement sensor, 23, 24 ... Attachment/detachment mechanism.

Claims (1)

[Claims] 1. The position of the outer container body 6 of the vibration generator 1 with respect to the stationary coordinate body 2 is detected by the position sensor 15, and the position of the outer container body 6 and the stationary coordinate body 2 is detected by the attachment/detachment mechanisms 23 and 24. A displacement sensor 22 is provided so that it can be attached and detached alternately. First, the displacement sensor 22 is fixed to the outer container body 6 by the attachment and detachment mechanism 23, and the vibration generator 1 is attached to the outer container body 6 by the displacement sensor 22.
Detects the position of the excitation end 14 of the displacement sensor 22
The position of the outer container body 6 with respect to the stationary coordinate body 2 or the load applied to the specimen 10 is adjusted to the command value while maintaining the distance C of the excitation end 14 with respect to the outer container body 6 constant through servo control using the detector as a detection unit. until it becomes
By increasing or decreasing the pressure of the air spring 8 that supports the vibration generator 1, the excitation end 14 is positioned;
After that, the displacement sensor 22 is attached to the attachment/detachment mechanism 2.
3 and 24, it is detached from the outer container body 6 and fixed to the stationary coordinate body 2, and constitutes servo control in which the position of the excitation end 14 with respect to the stationary coordinate body 2 is used as a control amount using the displacement sensor 22 as a detection part. , a vibration test method characterized by applying vibration to the specimen 10. 2 The position of the outer container body 6 of the vibration generator 1 with respect to the stationary coordinate body 2 is detected by the position sensor 15, and the vibration generator 1 is reciprocated in a direction parallel to the excitation axis 9 with the stationary coordinate body 2 as a reference. The stationary coordinates of the displacement sensor 22 are determined by open-loop or closed-loop control in which the position of the displacement sensor 22 is detected, the position is used as a control variable, and the output of the position sensor 15 is used as a reference input. position relative to body 2,
The position of the excitation end 14 with respect to the displacement sensor 22 is controlled to follow the position of the outer container body 6 with respect to the stationary coordinate body 2, and at the same time, the position of the excitation end 14 with respect to the displacement sensor 22 is controlled by servo control using the displacement sensor 22 as a detection section and the vibration generator 1 as an operation section. While keeping constant, the pressure of the air spring 8 supporting the vibration generator 1 is increased or decreased until the position of the outer container body 6 with respect to the stationary coordinate body 2 or the load applied to the specimen 10 reaches the command value. After positioning the swing end, the follow-up control of the displacement sensor 22 is released, the displacement sensor 22 is kept fixed to the stationary coordinate body 2, and the displacement sensor 22 is used as a detection part, and the stationary coordinate body 2 is fixed. A servo control is configured in which the position of the excitation end 14 relative to
A vibration test method characterized by applying vibration to.