JPH0214651B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an excitation device used for vibration testing of large equipment.

In this type of vibration device, horizontal vibration can be achieved by arranging the drive source that vibrates the vibration table on which the test object is mounted so that the drive direction is parallel to the mounting surface of the vibration table. Moreover, if the driving direction is arranged perpendicular to the mounting surface, vertical vibration can be performed.

Conventionally, when excitation is performed in the vertical direction, if the exciter is small, one shaft of the drive source can be connected to the center of the excitation table, and the shaft of the drive source can serve both as vibration transmission and as a guide in the driving direction. However, with a large vibration exciter,
If the center of gravity of the test object is far from the center of the vibration table, a large bending stress will be applied to the drive shaft, which may cause damage. Therefore, in the case of large equipment, there are two methods: arranging multiple drive shafts around the vibration table, and placing the drive shaft in the center and using a guide so that the plane vibrates parallel to the vibration table. There is a way to arrange it.

In Fig. 1, a plurality of drive shafts are arranged around a vibration table, and in the figure, 1 is a vibration table on which a test object is attached, 2a and 2b are hydraulic pistons as an example of a driving source, 3a, 3b is a hydraulic cylinder, 4a,
4b is a frame for fixing the hydraulic cylinders 3a and 3b, and 5a and 5b are inflow and outflow ports for oil that drives the hydraulic pistons. In this method, since the drive source is located around the vibration table, the bending stress acting on the drive shaft is small even if the center of gravity of the test object is some distance from the center of the vibration table. However, in this case, if the plurality of hydraulic pistons 2a and 2b do not move in the same way, they will not function as an exciter, and the plurality of hydraulic pistons 2
The axes a and 2b must be parallel, and precision is required in the work. Note that there is also a problem of parallelism when one drive shaft is placed at the center of the vibration table and guides are placed around the vibrating table.

Considering these issues, as shown in Figure 2,
A vibration device has been proposed in which a single drive shaft is arranged at the center of a vibration table and guides a pair of cylinders having the same axis center as this shaft center and having a circumferential surface around the vibration table. That is, in FIG. 2, 1 is an excitation table, 2 is an example of a hydraulic piston that is a driving source, 3 is a hydraulic cylinder, 4 is a mount for fixing the hydraulic cylinder, 5 is an oil inlet and outlet, and 6 is an excitation The inner cylinder 7 of the cylindrical guide attached to the stand is the outer cylinder of the cylindrical guide which is slidably fitted with the inner cylinder 6. With this method, it is only necessary to align the centers of the axis of the piston 2 and the axes of the inner cylinder 6 and outer cylinder 7, which are the cylindrical guides, and the dimensional accuracy required by using multiple drive shafts and guides as described above is reduced. The problem will disappear.

However, when excitation is performed using this method,
If the center of gravity of the mounted object is shifted,
During vibration, the vibration table may rotate around the cylindrical axis of the guide. When such a phenomenon occurs, electric wires for supplying power to the test object from the outside, pressure hoses for obtaining pressure, etc. are pulled, resulting in a drawback that the test cannot be performed.

It was also used as a biaxial vibration testing device in 1983.
There is a technique disclosed in Publication No. 124783. This uses parallel links or hydrostatic bearings to suppress rotational vibrations that are harmful to the rotational motion of the vibration table, that is, the direction of motion of the vibration exciter piston. In the case of the former, that is, a parallel link, the structure is such that lateral movement of the shaft is compensated for by bending or rotation of the bearing part, and axial movement is compensated for by air suspension.
This cannot stop the actual harmful vibrations in the other direction. On the other hand, the hydrostatic bearing structure shown in FIGS. 3 and 4 of the same publication is found to be effective to some extent. However, since this uses the same static pressure bearing surface in both the horizontal and vertical directions, only two parallel planes can be used, and if vertical vibration occurs before and after the horizontal excitation direction, the parallel link However, there is a problem in that this cannot be prevented.

This invention was made to solve the problems of the prior art, and is capable of suppressing rotational vibrations in all directions, and can also be used with an excitation table if necessary.
The purpose of the present invention is to obtain a large vertical vibrator that can be rotated 90 degrees and adjusted to correspond to the displacement of the center of gravity of an object to be measured.

That is, the present invention includes a cylindrical guide consisting of an inner cylinder attached to an excitation table and an outer cylinder that slides together with the inner cylinder over a long range in the excitation direction. A recess is provided vertically at each position,
Furthermore, wedges are provided on the inside of the outer cylinder at 180° intervals and are moved forward and backward by adjustment screws that can be operated from the outside to engage and disengage from the recess of the inner cylinder.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In the figure, numerals 1 to 7 are the same as in FIG. 2 above. Reference numeral 10 denotes a vertically elongated recess that is arranged at a pitch of 180° in the outer cylinder 7 and is opened toward the inside.Adjustment screws 9 are passed through the recess 10 from the outside in two places, upper and lower, and a vertically elongated recess is inserted at the tip of the recess 10. A wedge 8 is attached. On the other hand, 11 is vertically installed over almost the entire length of the inner cylinder 6 at a pitch of 90 degrees on the outer peripheral surface of the inner cylinder 6 which is fitted to the outer cylinder 7 so as to be slidably fitted over a long range in the excitation direction. The wedge 8 is slidably fitted in and out of the inner cylinder 6 by selecting two mutually disposed positions of the recess 11, thereby fixing the inner cylinder 6 in the circumferential direction, that is, serving as a rotation stopper. ing. In addition, when the vibration table 1 is rotated together with the inner cylinder 6, the wedge 8 may be retracted toward the outer cylinder 7 and removed from the recess 11.

As described above, according to the present invention, the inner cylinder 6 and the outer cylinder 7
It is possible to move in the axial direction within the wedge 8, and the displacement of rotation around the axis is regulated by the side surface of the wedge 8. At this time, if the metal sliding surfaces come into contact with each other, there is a risk of seizure, so an oil film is formed on the outer surface of the inner tube 6, the inner surface of the outer tube 7, and the side surface of the wedge 8 to prevent the metal surfaces from coming into contact with each other. It is a good idea to avoid. In addition, as shown in Fig. 4, recesses 11 are provided in the inner cylinder 6 at a pitch of 90°, and the wedge 8 can be slid into the recesses from the outside of the outer cylinder with the adjusting screw 9, so that the vibration table 1 can be moved freely. It becomes possible to rotate it 90 degrees, change its position, hold it with a wedge 8, and excite it.

That is, this example shows the case where a vertical vibration means is provided, but as mentioned above, in general, in this type of vibration device, vibration is applied to the vibration table on which the test object is mounted. driving means,
Horizontal vibration can be performed by arranging the drive direction parallel to the mounting surface of the vibration table.Therefore, by placing the horizontal vibration means on the vibration table 1 shown in FIG. If the test object is mounted on a vibration table (not shown) which is vibrated by this horizontal vibration means, it is possible to vibrate not only in the vertical direction but also in the horizontal direction. In this case, by simply rotating the inner cylinder 6 by 90 degrees and holding it with the wedge 8, it is possible to apply horizontal vibration to the test object in a direction different by 90 degrees. To describe the specific method of use in more detail, it includes a horizontal vibration means for the mounting surface of the vibration table 1 shown in FIG. It may be necessary to fix the vibration table to the vibration table 1 and perform vibration in the horizontal direction to the left, right, front, and back. For example, in a system where a power transmission line is connected from a steel tower to a transformer installed on the ground using a drop-in wire, when testing the vibration resistance of the bushing part of the transformer, it is necessary to test the vibration resistance of the bushing of the transformer. To explain the case in which the transformer is to be tested, first, when the transformer is mounted on the above-mentioned horizontal vibration table and horizontal vibrations are performed in the left, right, front, and rear directions. After the vibration is applied in the right direction, the transformer is lifted up from the horizontal vibration platform, and serves to prevent the inner cylinder 6 from rotating in the circumferential direction as shown in FIGS. 3 and 4. After rotating the inner cylinder 6 by 90 degrees by operating the wedge 8 and adjusting screw 9,
Using the adjusting screw 9, the wedge 8 is set in the recess 11 vertically provided on the outer circumferential surface of the inner cylinder 6 to stop the inner cylinder 6 from rotating in the circumferential direction, and the suspended transformer is subjected to the horizontal vibration. By placing it on a stand, it is possible to perform horizontal vibration in the front and rear directions of the transformer.

For this reason, the inner cylinder 6 is provided with vertical recesses 11 on its outer circumferential surface at a pitch of 90 degrees. In addition,
The reason why the wedges 8, which can be operated with adjustment screws 9 on both sides of the circumference at a pitch of 180° on the outer cylinder 7, is provided is that the inner cylinder 6 can be stopped from rotating at only one place on the circumference of the outer cylinder 7. , since the inner cylinder 6 is pressed to one side, they are arranged at 180° pitch to maintain balance.

As described above, according to the present invention, in order to prevent the rotation of the cylindrical guide consisting of the inner and outer cylinders, a wedge is provided in the outer cylinder part that can be inserted and removed with an adjustment screw at a pitch of 180°, and this wedge is inserted into the inner cylinder at a pitch of 90°. Since the wedge is selectively slid into the arranged recess, it is possible to freely insert and remove the wedge from the outside, and at the same time, by operating the adjustment screw, the inner cylinder connected to the vibration table can be rotated 90 degrees around the vertical axis. It has the advantage that it can be stopped at different positions, that is, the vibration table can be adjusted and rotated by 90 degrees as needed. According to this invention, the entire circumference of the inner and outer cylinders that slide together over a long range in the excitation direction is used as a static pressure bearing surface, so it is possible to suppress rotational vibration in any direction. can.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional vibrator, in which multiple driving pistons are placed around the vibrator, and a second vibrator.
The figure is a cross-sectional view of a conventional vibrator, in which one driving piston and a cylindrical guide are arranged concentrically, FIG. 3 is a cross-sectional view showing an embodiment of the present invention, and FIG. FIG. 4 is a sectional view of a main part taken along the - line in FIG. 3; In the figure, 1 is the vibration table, 2 is the hydraulic piston, 3 is the hydraulic cylinder, 6 is the inner cylinder of the guide, 7 is the outer cylinder of the guide, 8 is the wedge, 9 is the adjustment screw, and 10 is the external cylinder. A recess 11 is a recess provided in the inner cylinder.
Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A vibration exciter that applies vibration in a direction perpendicular to the vibration table mounting surface of the vibration testing machine, which includes an actuator whose center is concentric with the vibration table, an inner cylinder attached to the vibration table, and this inner cylinder. In a large-sized vibrator equipped with a cylindrical guide consisting of a cylinder and an outer cylinder that slide together over a long range in the excitation direction, recesses are vertically provided at 90° pitches on the outer peripheral surface of the inner cylinder, On the other hand, the outer cylinder is provided with adjustment screws that can be operated from the outside at 180° pitches, and wedges attached to each tip of the adjustment screws. A large-sized vibration exciter characterized by being able to be freely engaged and disengaged from and inserted into the machine.