JPH04372840A - Torsional shaker - Google Patents

Abstract

PURPOSE:To obtain a torsional shaker which can conduct precise torsion tests. CONSTITUTION:A torsional shaker is provided with a first motor 20, a second motor 20A, a locking device 22 for locking one end of a body under test 10 and the shaft of the first motor 20 and a locking device 22A for locking the other end of the body under test 10 and the shaft of the second motor 20A. Furthermore, a first inverter 30 for performing the speed feedback control for the first motor 20, a second inverter 30A for performing the speed feedback control for the second motor 20A and a shaking command device 32 for changing the speed command which is imparted to the first inverter 30 with respect to the second inverter are provided. Synchronizing means 40 and 40A for synchronizing the rotary angles of both motors are provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torsional vibration exciter used for testing specimens such as automobile joints by applying torsional vibrations to the specimens.

0002

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional torsional vibration exciter. In the figure, 10 is the specimen, 2
0, 20A are motors with the same rating (induction motor), 21,
21A, speed detector (pulse generator) PLG,
22 and 22A are lock devices, 30 and 30A are inverters, 31 is a reference speed command, 32 is an excitation command, and 33 is a switch. This vibration command device 32 generates a vibration command signal ΔN shown in FIG. 4(a).

In this configuration, when the vibration command signal from the vibration command unit 32 is not applied, both the motor 20 and the motor 20A are only receiving the reference speed command NK from the reference speed command unit 31. , same rotation speed NK
Rotate with. In this state, when the switch 33 is closed and the excitation command signal is generated from the excitation command unit 32, a signal obtained by adding the above excitation command signal to the reference rotation speed command signal NK from the reference speed command unit 31 is generated. is given to the inverter 30A as a speed command signal, and the electric motor 0 is applied to the specimen 10.
Torsion is added due to the speed difference of 20A and 20A.

0004

[Problem to be Solved by the Invention] In the conventional torsion testing machine, the speed difference between the electric motors 20 and 20A is simply controlled, and the rotation angle θ of the rotating shafts of both electric motors is ignored. As the required accuracy for torsion testing becomes higher, there is a problem that it cannot be adequately addressed, and this torsion testing machine has the following problems:
Since torque excitation cannot be performed, it is inconvenient that a torsion test by speed difference excitation and a torsion test by torque excitation cannot be performed on the same specimen using a single vibrator.

The present invention was made to solve this problem, and it is an object of the present invention to provide a torsional vibrator that can perform more precise torsion tests than conventional ones.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a locking device for locking a first electric motor, a second electric motor, one end side of a specimen and a shaft of the first electric motor, and a locking device for locking a shaft of the first electric motor. a locking device that locks the other end of the specimen and the shaft of the second electric motor; a first inverter that performs speed feedback control of the first electric motor; and a second inverter that performs speed feedback control of the second electric motor. in a torsional vibrator comprising an inverter and an excitation command device that varies a speed command given to the first inverter with respect to the second inverter, synchronization means for synchronizing the rotation angles of the two electric motors. The configuration has the following.

According to a second aspect of the present invention, the synchronizing means is a synchronizing electric machine connected to the rotating shafts of the first electric motor and the second electric motor, respectively.

According to a third aspect of the present invention, a first electric motor and a second electric motor, a locking device for locking one end side of the specimen and the shaft of the first electric motor, and a locking device for locking the shaft of the first electric motor and the other end side of the specimen; a locking device that locks the shaft of the electric motor; a first inverter that performs speed feedback control of the first electric motor; a second inverter that controls the torque of the second electric motor; The configuration includes a reference torque command device that gives a torque command, and an excitation command device that gives a variable torque command to the second inverter. Torsional vibration exciter.

[0009] According to a fourth aspect of the present invention, a first electric motor and a second electric motor, a locking device for locking one end side of the specimen and the shaft of the first electric motor, and a locking device for locking the shaft of the first electric motor and the other end side of the specimen; a locking device that locks the shaft of the electric motor; a first inverter that performs speed feedback control of the first electric motor; a second inverter that performs speed feed control of the second electric motor; and a reference speed command for both of the inverters. a reference speed command that gives an excitation command to one of the two inverters, an excitation command that gives an excitation command to one of the two inverters, synchronization means for synchronizing the rotation angles of the two electric motors, and a method for electrically opening the synchronization means. a first switch, the torque command device for supplying a reference torque command to the one inverter, and a second switch for switching and connecting the reference speed command device and the torque command device to the one inverter; The vibration command device is configured to be able to switch output variable torque/variable speed command signals.

0010

According to the first aspect of the invention, since there is a synchronizing means, it is possible to perform a torsion test on a specimen while preventing deviation in the rotation angles of both electric motors.

In the third aspect of the invention, since the second inverter is given an output deviation between the reference torque command device and the vibration command device, it is possible to apply torsional torque vibration to the specimen.

[0012] Torque excitation can be applied.

In the fourth aspect of the invention, since the vibration command device is capable of outputting a differential velocity vibration command and a torque vibration command signal,
By switching both switches, one vibrator can
Both differential speed excitation and torque excitation can be performed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 40 and 40A are synchro electric machines whose secondary sides are connected via a resistor R, and whose primary sides are both connected to an excitation power source (voltage: vo, frequency: fo) AC.
It is connected to the. The synchro electric machine 40 has one end of its rotating shaft connected to the electric motor 20 via the locking device 22, and the other shaft end connected to the common specimen 10. One shaft end of the synchro electric machine 40A is connected to the electric motor 20A via a locking device 22A, and the other shaft end is connected to the common specimen 10.
It is connected to the shaft. 41 is a detector that detects and amplifies the secondary induced voltage v2 of the synchro electric machine 40 and 40A. 42 is a rotation angle detector that detects the rotation angle θ of the co-specimen 10 from the detection value of the detector 41. The other configurations are the same as those in FIG.

FIG. 4 shows an example of the vibration command signal generated by the vibration command device (differential velocity vibration command device) 32 of this embodiment. (a) is a constant level excitation command signal, (b) is a sine wave excitation command signal, and (c) is a triangular wave excitation command signal.

In this configuration, when the vibration command signal from the vibration command device 32 is not applied, both the electric motor 20 and the electric motor 20A rotate at the same rotational speed NK. In this state, the switch 33 is closed and the excitation command device 32 is activated (see FIG. 4).
When the sine wave excitation command signal ΔN sin ωt shown in b) is generated, a signal obtained by adding the above excitation command signal to the reference rotation speed command signal NK from the reference speed command unit 31 is given to the inverter 30A as a speed command signal. .

As a result, the period t1 to t2 in FIG. 4(b)
Then, the output frequency f2 of the inverter 30A is higher than the output frequency f1 of the inverter 30, and during the period t2 to t3 in FIG. is subjected to torsional angle excitation that varies at a constant period.

Since the synchro electric machines 40 and 40A generate synchronizing forces so that the slip frequencies are the same, the rotation angle θ1 of the rotating shaft of the electric motor 20 and the rotation angle θ2 of the rotating shaft of the electric motor 20 are synchronized ( θ=θ1 =θ2). This rotation angle θ is detected by a rotation angle detector 42 and guided to a display or recorder (not shown).

FIG. 2 shows a block diagram of a torsional torque exciter. In the figure, 50 and 50A are torque detectors. The torque detector 50 is connected to the locking device 22
The locking device 2 is coupled to the electric motor 20 via the
3, and detects the torque T1 generated by the electric motor 20 and the rotational speed N1 of the electric motor 20. Torque detector 50A is coupled to electric motor 20A via locking device 22A, and locking device 23A.
The electric motor 20A detects the torque T2 generated by the electric motor 20 and the rotational speed N2 of the electric motor 20A. A torque difference detector 51 detects a relative torque difference ΔT from a detection value T1 of the torque detector 50 and a detection value T2 of the torque detector 50. This detected relative torque difference ΔT is guided to a display or recorder (not shown). 52 is a reference torque command device, which is a reference torque command T1
is applied to the inverter 30A. The vibration command device 32A is a torque vibration command device, and sends out torque vibration command signals having waveforms shown in FIGS. 4(a) to 4(c).

In this configuration, the vibration command unit 32A is now
Assume that a sine wave excitation command signal shown in FIG. 4(b) is generated. The electric motor 20 rotates at a rotation speed NK,
Generates torque T1. The electric motor 20A is shown in FIG. 4(b).
During the period t1 to t2, the output W of the inverter 30A
2 is higher than the output W1 of the inverter 30, and as shown in FIG.
), W2 of the inverter 30A
is lower than the output W1 of the inverter 30, and the specimen 10 is subjected to torsional torque excitation that varies at a constant cycle.

FIG. 3 shows a torsional vibration exciter that can be switched between a torsional angle vibration exciter and a torsional torque vibration vibration machine by switching a switch. , the power switch 34, and the vibration command changeover switch 35 are closed, and when torsional torque vibration is to be performed, both switches 34 and 35 are opened. The vibration command device 32B is a vibration command device that can switch and output the differential speed vibration command and the torque vibration command signal.

In this embodiment, an excitation command unit 32B for giving a fluctuation command is provided separately from the reference speed command unit 31 and reference torque command unit 52, and this excitation command unit 32B receives the differential speed excitation command and the torque command. Since an excitation command signal can be output, by switching both switches 34 and 35, one vibrator can perform both differential velocity excitation and torque excitation.

[0024]

[Effects of the Invention] As explained above, the present invention provides a synchronizing means for synchronizing the rotation angles of the first electric motor and the second electric motor, thereby making it possible to prevent deviations in the rotation angles of the two electric motors. Therefore, a highly accurate torsion test can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing still another embodiment of the present invention.

FIG. 4 is a diagram showing a vibration command signal generated in the above embodiment.

FIG. 5 is a block diagram showing a conventional torsional vibration exciter.

[Explanation of symbols]

10 Specimen 20, 20A Electric motor 21, 21A Speed detector 22, 22A Lock device 23, 23A Lock device 30, 30A Inverter 31 Reference speed command device 32, 32A, 32B Excitation command device 34, 35
Switch 40, 40A Synchro electric machine 42 Rotation angle detector 50, 50A Torque detector 51 Relative torque difference detector 52 Reference torque command AC Excitation power supply

Claims (4)

[Claims] Claim 1: A first electric motor, a second electric motor, a locking device for locking one end of the specimen and the shaft of the first electric motor, and the other end of the specimen and the shaft of the second electric motor. a first inverter that performs speed feedback control of the first electric motor; a second inverter that performs speed feedback control of the second electric motor; and a speed command given to the first inverter. A torsional vibration exciter including a vibration command device that varies the vibration with respect to the second inverter, characterized in that the torsion vibration exciter has a synchronization means for synchronizing the rotation angles of both the electric motors. Shaking machine. 2. The torsional vibration exciter according to claim 1, wherein the synchronizing means is a synchronized electric machine connected to the rotating shafts of the first electric motor and the second electric motor, respectively. 3. A first electric motor, a second electric motor, a locking device for locking one end of the specimen and the shaft of the first electric motor, and the other end of the specimen and the shaft of the second electric motor. a lock device for locking the first electric motor, a first inverter for controlling the speed feedback of the first electric motor, a second inverter for controlling the torque of the second electric motor, and a second inverter for controlling the torque of the second electric motor;
A torsional vibration exciter comprising: a reference torque command device that gives a reference torque command to the second inverter; and a vibration command device that gives a variable torque command to the second inverter. 4. A first electric motor, a second electric motor, a locking device for locking one end of the specimen and the shaft of the first electric motor, and the other end of the specimen and the shaft of the second electric motor. a first inverter that performs speed feedback control of the first electric motor; a second inverter that performs speed feed control of the second electric motor; and a standard that provides a reference speed command to both of the inverters. a speed command device, a vibration command device for giving a vibration command to one of the two inverters, a synchronization means for synchronizing the rotation angles of the two electric motors, and a first one for electrically opening the synchronization means.
a switch, the torque command device for giving a reference torque command to the one inverter, and a second switch for switching and connecting the reference speed command and the torque command to the one inverter; The device has variable torque/
A torsional vibration exciter characterized by being capable of outputting a variable speed command signal by switching.