公开(公告)号：JPH06160234A

公开(公告)日：1994-06-07

申请号：JP32898092

申请日：1992-11-16

Applicant: NAT AEROSPACE LAB

Inventor： ANDO YASUYOSHI ,  HANZAWA ASAO ,  SUZUKI SEIZO ,  MATSUSHITA KO ,  FUJII KENJI ,  SUZUKI KOICHI ,  SOTODATE MASATAKA

IPC: G01M9/04

Abstract: PURPOSE:To provide an automatic flutter stopper for lowering Mach line or dynamic pressure automatically below a limit level immediately upon occurrence of flutter in a model thus allowing high speed flutter wind tunnel test in transonic region without collapsing the model. CONSTITUTION:In a wind tunnel equipped with an air extraction chamber 8 for flutter test in transonic region, a flutter stop member 2 having resistance effect is contained in the wall surface at a measuring part 1. The flutter stop member 2 is inserted into the measuring part by means of an actuator 6 based on a flutter occurrence signal delivered from a flutter detector, i.e., a strain gauge 5.

公开(公告)号：JPH09269274A

公开(公告)日：1997-10-14

申请号：JP10610696

申请日：1996-04-01

Applicant: NAT AEROSPACE LAB

Inventor： SOTODATE MASATAKA ,  SUZUKI SEIZO ,  ANDO YASUYOSHI ,  MATSUSHITA KO

IPC: G01M9/08

Abstract: PROBLEM TO BE SOLVED: To provide a flutter stop device moving the center-of-gravity of a wing element instantaneously and positively with simple mechanism at the time of the generation of flutter and fittable also to a thin wing by connecting a mass to a wing body on the rear edge side using a conductor wire such as a steel wire in the state of applying tension to the mass by an elastic body in the direction of pushing it out onto the front edge side. SOLUTION: In a wing 1, damping by aerodynamic force decreases with the increase of aerodynamic force, and vibration increases rapidly to generate flutter. When this initial indication is detected to send a flutter stop signal to a flutter stop device, a switch 30 is closed, and a current of such a grade as to fuse in about 15msec flows to a steer wire 11. Since tension is previously applied to a mass 6 by an elastic body 8, the steel wire 11 expanded and fused becomes unable to withstand the tension and breaks, and the mass 6 jumps out toward the front edge side. Upon reaching the end of the front edge, the mass 6 hits cushioning material 13 so as to be reduced in speed, and an iron plate 7 is attracted to a magnet 12, so that the mass 6 is captured and stopped.

公开(公告)号：JPS60150481A

公开(公告)日：1985-08-08

申请号：JP766184

申请日：1984-01-19

Applicant: NAT AEROSPACE LAB

Inventor： SOTODATE MASATAKA

IPC: F03D7/04 ,  F03D7/02

Abstract: PURPOSE:To improve a control characteristic as well as to aim at securability in an overspeed limiting device for a windmill, by making the device so as to control oil pressure for a hydraulic cylinder being connected to a pitch variable mechanism, with a solenoid proportional relief valve whose current is controlled by a speed of rotation in the windmill and its pitch angle. CONSTITUTION:When a coil current of a solenoid proportional relief valve 13 is once raised up to a allowable maximum current from 0mA and again varied down to the 0mA, variations in a pitch angle theta and a pitch angle signal theta' show a hysteresis characteristic as shown in illustration. And, the pitch angle theta' is partially fed back to a drive circuit 24 of the solenoid proportional relief valve 13, thus making it work to negate the hysteresis characteristic. That is to say, oil pressure in a hydraulic cylinder connected to a pitch variable mechanism is controlled by the relief valve 13 after a speed of rotation and the pitch angle signal theta' of a windmill 3 are fed back to the drive circuit 24. With this constitution, the windmill's overspeed limitation in time of a strong wind is made so as to be performable in a sure and highly accurate manner.

公开(公告)号：JPS6073067A

公开(公告)日：1985-04-25

申请号：JP17991483

申请日：1983-09-28

Applicant: NAT AEROSPACE LAB

Inventor： SOTODATE MASATAKA

IPC: F03D7/04 ,  F03D7/02

Abstract: PURPOSE:To prevent the overspeed rotation of a windmill, by controlling the hydraulic pressure of a hydraulic cylinder with the use of an electo-magnetically proportional relief valve. CONSTITUTION:When a windmill catches the wind so that the rotating torque exceeds the load side torque, the maximum current runs through an electro-magnetically proportional relief valve 13 which is therefore fully closed. If a solenoid valve 12 is opened for Tsec, oil is fed into a hydraulic cylinder 7 which moves a pitch drive rod 5 rightward so that the pitch angle of blades 3 is started to be shifted to its starting pitch. Simultaneously, the rotational speed of a windmill shaft 1 is started to be accelerated. The hydraulic pressure increases as the rotational speed increases so that the pitch drive rod 5 is further pushed and then is stopped by a mechanical stopper 18. With this arrangement the shift from the starting pitch to the running pitch is completed.

公开(公告)号：JPS6394130A

公开(公告)日：1988-04-25

申请号：JP23991686

申请日：1986-10-08

Applicant: NAT AEROSPACE LAB

Inventor： KIKUCHI TAKAO ,  KAYABA SHIGEO ,  SUZUKI SEIZO ,  MUROTA KATSUICHI ,  ANDO YASUYOSHI ,  SOTODATE MASATAKA

IPC: G01M9/00 ,  G01M9/04

Abstract: PURPOSE:To stop a test body from fluttering and to prevent the test body from being broken owing to excitation by a panel which has many ventilation holes while stood against an air flow at an upstream position of a test body support position in a wind channel. CONSTITUTION:The panel 1 consisting of the frame 3 and a wire gauge 2 is stood pivotally on the floor 6 of a blade model 7 at the upstream position in the wind channel. The panel 1 is laid face-down on the floor 6 first and the wind velocity in the wind channel is increased gradually. The signal of an accelerometer 8 mounted on the blade model 7 is monitored during this period and when the blade model 7 begins to flutter, a signal is sent out to an unshown panel driving device to raise the panel 1 speedily from the floor 6. An air flow is reduced in speed and rectified by the many ventilation holes of the panel 1 to stop the blade model 7 from fluttering. At this time, the disturbance of the air flow behind the panel 1 is small, so the blade model 7 never flutters owing to excitation after the stop of the fluttering.