JPS582371B2 - Shindoshi Kenki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration testing machine for conducting vibration resistance tests of various structures.

Figure 1 shows the configuration of a conventional vibration tester. In the figure, 1 is the foundation of the vibration tester, 2 is a vibration table, 3 is a horizontal shaker, and 4 is the flow rate of pressure oil to the shaker 3. 5 is an accumulator, 6 is a hydraulic power source, and 7 is an oil tank.

The vibration table 2 is restrained in a horizontal plane by a guide bearing 8.

The displacement of the vibration table 2 is detected by a detector 9.

The servo amplifier 11 operates in a direction that reduces the deviation between this displacement feedback signal and the input signal from the signal generator 10.
drives the servo valve 4.

The hydrostatic bearing connection joint 12 is connected to the piston rod 3a of the vibrator 3.
It consists of a fork 13 directly connected to the vibration table 2, and a left bracket 14 and a right bracket 15 that are directly connected to the vibration table 2 and sandwich the fork 13 therebetween.

The gap between the fork 13 and the brackets 14 and 15 in the vibration direction is kept to a small value of about several tens of microns.

The hydrostatic bearing surfaces of the brackets 14 and 15 facing the fork 13 are provided with pockets 16 and 17, respectively.

This pocket 16 has a hydraulic chamber 19 on the vibration table side of the vibrator 3.
Pressure oil is supplied from through a throttle 20.

Further, pressure oil is supplied to the pocket 17 from a hydraulic chamber 18 on the side opposite to the vibration table via a throttle 21.

When pressure oil is now supplied to the hydraulic chamber 18 of the vibrator 3 by the servo valve 4, pressure oil is also supplied to the pocket 17 through the throttle 21 at the same time.

Therefore, when the piston rod 3a is pushed to the right, the pressure in the right pocket 17 increases, and a rightward force moves on the bracket 15, driving the vibration table 2 to the right.

The same holds true when driving the vibration table 2 to the left.

The vibration table 2 can be vibrated by the above-described operation.

However, in the conventional vibration testing machine shown in FIG. Because the inflow of pressure oil is delayed by the supply pipe system, the piston rod 3a and fork 13 move before an oil film is formed on the hydrostatic bearing surface of the hydrostatic bearing coupling joint 12, and come into contact with the bracket 14.15 and become static. There is a possibility of damaging the pressure bearing surface.

In addition, if an abnormal situation such as destruction of the test object occurs and the hydraulic pump is brought to an emergency stop, both hydraulic chambers 18 and 19 of the vibrator 3 and the pocket 16 of the hydrostatic bearing coupling joint 12
．． The pressure at section 17 suddenly drops and the piston rod 3a stops, but due to the movement of the vibration table 2 due to inertial force, the fork 13 and brackets 14 and 15 of the hydrostatic bearing coupling joint 12
may come into contact and damage the hydrostatic bearing surface.

In view of the above points, it is an object of the present invention to prevent the oil film of the hydrostatic bearing coupling joint from running out even during startup and emergency stop, and to prevent damage due to contact between the static pressure bearing surfaces.

The present invention has a structure in which the power from the vibrator is transmitted to the vibration table via a static pressure bearing connection joint, and the pressure fluid acting on both hydraulic chambers of the vibrator is connected to the static pressure bearing through a throttle. In a vibration testing machine led to the pocket of the silent pressure bearing of the joint, the hydraulic pressure is used to supply pressure oil directly from the hydraulic source to the silent pressure bearing joint for a certain period of time during startup and emergency stop as a means of supplying pressure oil to the silent pressure bearing joint. It is equipped with a circuit.

An embodiment of the apparatus of the present invention will be described below with reference to the drawings.

FIG. 2 shows an example of the apparatus of the present invention, and in the figure, the same reference numerals as in FIG. 1 indicate the same parts.

Pressure oil from the hydraulic source 6 is supplied to the servo valve 4 through a main circuit switching valve 22 controlled by a switch 29.

Pockets 16 and 17 of brackets 14 and 15 of hydrostatic bearing coupling joint 12 are supplied with pressure oil from both hydraulic chambers 18 and 19 of vibrator 3, and check valve 2
4.25 and its upstream check valve 23 with pilot
Pressure oil is also supplied from the hydraulic source 2B through the hydraulic pressure source 2B.

The flow rate from this hydraulic source 2B is the check valve with pilot 2.
Controlled by 3.

Pilot pressure for the pilot check valve 23 is supplied from a hydraulic source 28 through a pilot switching valve 26 .

The pilot switching valve 26 is controlled by a control device 27 that operates in conjunction with the pump switch of the hydraulic power source 6 and the main circuit switching valve 22.

FIG. 3 schematically shows the switch circuit of the control device 27. In the figure, the switch SWI is in contact with the hydraulic power source 6 when it is on, and is separated when it is off.

The switch SW2 is in contact with the main circuit switching valve 22 when it is OFF, and is separated when it is ON.

Switch SW3 is connected when the timer signal is ON, and the switch SW3 is turned ON.
Leave with F.

The switch SW1 and the switch SW2 are connected in series, and the switch SW3 is connected in parallel to generate a control signal for the pilot switching valve 26.

In addition, in FIG. 2, the pilot check valve 23 is removed, and the check valve 24. Even if 25 is replaced with a pilot check valve, it has the same function.

Next, the operation of one embodiment of the apparatus of the present invention described above will be explained along the operation diagram of FIG. 4.

FIG. 4 is a diagram showing the operating order of each element of this device,
From the top, the operation of the hydraulic power source 6, the main circuit switching valve 22, the pilot switching valve 26, and the timer in the control device are shown, respectively.

At the time of startup, when the hydraulic power source 6 is turned on, the pilot switching valve 26 is operated by the control device 27, and pilot pressure is generated.

The check valve 23 with a pilot is oriented so that the pressure oil from the hydraulic source 28 passes through the hydrostatic bearing coupling joint 12 only when pilot pressure is applied. An oil film is formed on the surface.

Next, by turning on the switch 29 of the main circuit switching valve 22, pressure oil is supplied to the drive system of the vibration testing machine.

The timer in the control device 27 turns on the main circuit switching valve 22.
, starts operating when OFF.

Therefore, at this time, the timer turns on and turns off after a certain period of time.
Becomes FF.

That is, by the switch circuit shown in FIG. 3, pressure oil is supplied from the hydraulic source 2B to the silent pressure bearing coupling joint 12 from the time when the hydraulic source 6 is started until the timer is turned off.

Next, at the time of emergency stop, when the hydraulic power source 6 is switched off, the switching valve 22 of the main circuit is also turned off, and the timer in the control device 27 is turned on.

The timer turns off after a certain period of time. While the timer is ON, the check valve 23 with pilot opens and the hydraulic power source 2
Pressure oil is supplied from 8 to the hydrostatic bearing connection joint 12 .

Therefore, in the conventional method, there was a possibility of damage due to contact with the bearing surface of the silent pressure bearing connection joint during startup or emergency stop, but the present invention can prevent this and improve its practicality. The effect is extremely large.

Note that the present invention is also effective for a vibration testing machine that is equipped with a vertical vibrator and has a hydrostatic bearing coupling joint device having a similar configuration.

[Brief Description of the Drawings] Figure 1 is a partial cross-sectional view of the configuration of a conventional vibration testing machine, and Figure 2 is a partial cross-sectional view of an embodiment of the vibration testing machine of the present invention. 3 is a circuit diagram of a control switch for a pilot switching valve used in the device of the present invention, and FIG. 4 is a diagram for explaining the operation of one embodiment of the device of the present invention. 2... Vibration table, 3... Vibrator, 24, 25... Check valve, 23... Check valve with pilot, 26... Solenoid switching valve, 27... Control device.

Claims (1)

[Claims] 1 A vibration testing machine in which the pressure fluid acting on both hydraulic chambers of the vibrator is guided through a restriction into the hydrostatic bearing pocket of the hydrostatic bearing coupling joint that transmits the power from the vibrator to the vibration table. A vibration testing machine characterized in that the hydrostatic bearing coupling joint is provided with a hydraulic circuit that directly guides pressure oil for a certain period of time from a hydraulic source during startup and emergency stop.