JPS6258454B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turbine blade rotation control device used for inspecting turbine blades of a jet engine.

If the turbine blades of a jet engine, especially a jet engine for aircraft, are damaged or broken, it will cause a serious accident, so the turbine blades, which are the heart of the jet engine, should be checked regularly to make sure there is no damage. Needs to be inspected.

The current method of inspecting turbine blades is to insert a fiberscope called a borescope into the engine through an inspection opening provided in each engine, and then maintenance personnel can see the condition of the turbine blades as shown on the fiberscope. It is common practice to perform visual inspection with the naked eye or through a television screen. However,
A large number of turbine blades, for example, more than 100, are arranged radially around the rotor shaft, and for inspection, these turbine blades must be mechanically rotated by a desired angle accurately and reliably.

Conventionally, methods for mechanically rotating turbine blades from the outside for inspection include engaging a ratchet trench or box wrench with a gearbox through a turning port and feeding the turbine blades by hand, or using an air motor to rotate the turbine blades from the turning port. A method is adopted in which the air motor is mounted and adjusted using a foot-operated regulator while feeding the turbine blades. However, using any of the above methods, it is difficult to reliably feed the turbine blades one by one, and it takes time to feed and position the turbine blades.
The drawback was that it was not possible to confirm whether all turbine blades had been inspected.

The rotation control device for inspecting turbine blades of a jet engine according to the present invention includes a pulse motor for feeding the turbine blades, a drive circuit for driving the pulse motor, and a drive circuit that controls the drive circuit to intermittently operate the pulse motor. The control device includes a pulse oscillator, which drives the drive circuit in response to pulses from the pulse oscillator, counts pulses from the pulse oscillator, and brakes when the counting result reaches a predetermined value. The vehicle includes a first circuit that generates a signal, and a second circuit that generates a drive signal after a predetermined time has elapsed after the generation of the braking signal.

That is, in the device of the present invention, a pulse motor is used to feed the turbine blades, a first circuit counts the pulses of a pulse oscillator sent to the pulse motor, and when the counted value reaches a predetermined value, a braking signal is generated. is generated to stop the pulse motor, and after a predetermined period of time has elapsed, the second circuit generates a drive signal to drive the pulse motor. Therefore, it becomes easy to feed the turbine blades one by one and to position the turbine blades.

The present applicant had previously proposed a system for detecting damage occurring in jet engine turbine blades under the title ``Flaw Detection System for Jet Engines'' (Japanese Patent Application No. 136446/1983, ie, Japanese Patent Application Laid-open No. 60843/1983).
issue). The device of the invention is compatible with this system.

The present invention will be described below with reference to illustrated embodiments. In the drawing, the device of the present invention includes a pulse motor 10 with a high shaft output, and the rotational power of this pulse motor is transmitted to a gear box through a suitable gear (not shown), and is connected to a turbine blade of a jet engine (not shown). (not shown). The pulse motor 10 is driven and controlled by a driver 12 via an amplifier 11. This driver 12 has a pulse motor 1
A command signal for switching and controlling the rotational direction of 0 is sent from the control panel 13. The input of the command signal is simply indicated by an arrow in the drawing.

A signal for driving and controlling the pulse motor 10 is sent to the driver 12 from the control device. The control device includes a pulse oscillator 15 that generates the pulses necessary to drive the pulse motor 10. This pulse oscillator 15 is configured such that its pulse rate can be changed by a command signal from the control panel 13.

The pulses generated by the pulse oscillator 15 are sent to the gate circuit 16. Gate circuit 16 continues to drive pulse motor 10 by sending pulses to driver 12 while it is open. On the other hand, gate circuit 1
6 sends the pulse output to a counter 17, which counts the pulses. Thus, the count result of the counter 17 is sent to the comparator 18.

The comparator 18 sets a value corresponding to the feed amount per turbine blade determined from the number of turbine blades of the engine to be inspected as a reference value, and is equipped with a decoder (not shown) for decoding this value. There is. The comparator 18 generates a signal at its output when the pulse input from the counter 17 reaches a set reference value. The output signal is sent to gate circuit 16, which closes it.
As a result, no pulses are sent to the driver 12, and the pulse motor 10 is stopped. In other words, the pulse motor 10 rotates the turbine blade 1 until the comparator 18 generates the output signal.
I will send you a portion.

The output of comparator 18 is blade counter 1
9 is also supplied. Therefore, each time a turbine blade is fed, a count is incremented, and the count is digitally displayed to inform the operator of the total number of turbine blades that have been fed so far.

The output of comparator 18 is also sent to and triggers rest time oscillator 20. Rest time oscillator 20 therefore generates a pulse and sends the pulse to counter 21 . This counter counts pulses and sends a count output to comparator 22. Comparator 22 is a decoder (not shown)
A value corresponding to the time required to inspect one turbine blade using this decoder is set as a reference value. Therefore, comparator 22
compares the pulse sent from the counter 21 with a set reference value, and when a match is found, generates a drive control signal and sends it to the gate circuit 16. The gate circuit 16 opens the previously closed gate in response to the received drive control signal, and the pulse oscillator 15 supplies pulses to the driver 12 again to drive the pulse motor 10. The stop time setting circuit that defines the stop time of the turbine blades and generates the drive control signal is composed of a rest time oscillator 20, a counter 21, and a comparator 22 in the illustrated embodiment, but other suitable circuits, such as a time constant It can be constructed using a circuit or a monostable multivibrator.

In the present invention, as described above, the pulse motor 10 is driven in response to a drive control signal to feed one turbine blade, the turbine blade is stopped for a predetermined period of time in response to a braking control signal, and this operation is repeated. It is something to do.

In the device of the present invention, as described above, the feeding speed of the turbine blade can be set by changing the pulse rate of the pulse oscillator, and the rotation angle of the turbine blade can be set according to the reference of the comparator 18 as desired or according to the type of jet engine. The stop time of the turbine blades can be set appropriately by changing the set value, and the stop time of the turbine blades can also be set appropriately by changing the standard set value of the comparator 22. This can be achieved by adjusting the The device of the invention is therefore very flexible.

As described above, according to the present invention, the pulses for driving the pulse motor that feeds the turbine blades are counted, the pulse motor is braked according to the counted value, and then the pulse motor is driven after a predetermined period of time has elapsed. Therefore, when inspecting the turbine blades, the feeding and positioning of the turbine blades are automated, significantly improving the efficiency of inspection work.

Furthermore, according to the present invention, the above advantages are combined to improve inspection accuracy and reliability.

[Brief explanation of the drawing]

The drawing is a block diagram showing one embodiment of the apparatus of the present invention. [Explanation of symbols of main parts] Pulse motor……
10. Drive circuit……12. Pulse oscillator……
15, 1st circuit……16, 17, 18, 2nd circuit
The circuit......20, 21, 22.

Claims (1)

[Claims] 1. A pulse motor for feeding turbine blades, a drive circuit for driving the pulse motor, and a control device that controls the drive circuit to rotate the pulse motor intermittently, the control device a pulse oscillator; a first circuit that drives the drive circuit in response to pulses from the pulse oscillator, counts the pulses from the pulse oscillator, and generates a braking signal when the counting result reaches a predetermined value; and a second circuit that generates a drive signal after a predetermined period of time has elapsed after generation of the braking signal. A rotation control device for inspecting turbine blades of a jet engine. 2. The rotation control device according to claim 1, wherein the first circuit counts the occurrence of the braking signal as a count of the number of blades to be inspected. 3. In the device according to claim 1 or 2, the first circuit that generates the braking signal includes a counter, and the output of the counter is set to a preset reference value corresponding to the rotation angle of the turbine blade. A rotation control device comprising: a comparator that compares and outputs a comparator. 4. In the device according to claim 1,
A second circuit for generating a drive signal includes a pulse oscillator triggered in response to the output of the first circuit for generating a braking signal, a pulse counter, and a pulse counter for adjusting the output of the counter in response to the stopping time of the turbine blade. A rotation control device comprising a comparator that compares with a preset reference value and outputs an output. 5. The rotation control device according to claim 3 or 4, wherein the control device includes a gate circuit and gates the pulse from the pulse oscillator in response to the output of the comparator. 6. In the device according to claim 1,
1. A rotation control device, wherein the pulse oscillator is configured to set a pulse repetition period according to a desired rotational speed of the turbine blades. 7. In the device according to claim 1,
A rotation control device characterized in that the drive circuit is capable of switching the rotation direction of the pulse motor.