JPH0714848Y2 - Dynamometer - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a dynamometer for testing a drive train.

B. Outline of the Invention The present invention improves the test performance of a dynamometer for testing a power transmission system by switching the torque control amplifier to a low gain when the absorption torque or drive torque from the test piece approaches zero. The hunting phenomenon is suppressed without lowering.

C. Conventional technology The power transmission system of an automobile includes a clutch, a transmission, a propeller shaft, a differential gear, and a rear axle, and the test equipment is also a part of the power transmission system's unit test equipment or a chassis dynamometer. An endurance test,
It is designed to perform noise and vibration tests.

FIG. 2 shows a test apparatus for the transmission alone. A direct-current motor 2 is prepared in place of the engine as the drive source of the transmission 1 to be the sample, and the speed and torque are controlled. The control of the electric motor 2 is performed by the control device 3 including an operation program command device and a power conversion device. On the other hand, a DC generator 4 including power measuring means is prepared as an output absorption source of the transmission 1, and the generator 4 itself is configured to have an electric inertia force or a structure in which a flywheel is coupled to absorb the absorption torque or The speed is controlled by the controller 5.

D. Problems to be Solved by the Invention In a power transmission system test device, the transmission, etc. to be tested contains a gear inside, so backlash of the gear may cause hunting on the drive side and the absorption side. .

For example, in the test device of FIG. 2, when the drive side DC motor 2 is in steady operation (acceleration / constant speed / deceleration, etc.) and the absorption torque of the absorption side DC generator 4 is small, when the drive side decelerates or reduces torque. The backlash of the transmission gears in the transmission 1 may cause hunting with the absorption side, which may lower the test performance or damage the test piece and the test apparatus.

In order to suppress this hunting phenomenon, it is conceivable to lower the responsiveness of the control system on the driving side and the absorbing side, but this is difficult to secure the test performance such as responsiveness.

An object of the present invention is to provide a dynamometer capable of suppressing the hunting phenomenon without deteriorating the test performance.

E. Means and Actions for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a dynamometer using a power transmission system as a test piece for controlling the torque of the test piece in a normal gain control state and a low gain control state. A torque control amplifier that can be switched to a state, a first switching means that switches the torque control amplifier to a low gain control state when the absorption or drive torque for the sample is close to zero, and when the control state for the sample changes And a second switching means for forcing the torque control amplifier to a normal gain, and when the absorption or drive torque for the test piece approaches zero, the torque control amplifier is set to a low gain to suppress the hunting phenomenon with the test piece. Then, when the control state for the test piece changes, the torque control amplifier is returned to the normal gain and returned to the normal response required for the test.

F. Embodiment FIG. 1 is a circuit diagram of an absorption side control system showing an embodiment of the present invention. The torque control amplifier 6 calculates the proportional integral (PI) of the deviation by matching the torque setting value and the torque detection value, and this output is used as the current command of the current control amplifier 7.
The output of the current control amplifier 7 is used as a control signal for a control target (for example, the DC generator 4 in FIG. 2).

In a control system having such a torque control system and a current control system, switching means for switching the gain of the torque control amplifier 6 is provided for suppressing hunting. This switching means will be described below.

In the torque control amplifier 6, the operational amplifier 11 is provided with two feedback circuits in parallel. Both feedback circuits are made into a series circuit of resistors 12 and 13, capacitors 14 and 15, and a switching contact 17 of the relay 16, respectively,
The time constants of resistor 12 and capacitor 14 are resistor 13 and capacitor 15
And the proportional gain of the torque control amplifier by the resistor 12 and the capacitor 14 is made equal to the conventional one, and the proportional gain by the resistor 13 and the capacitor 15 is lowered.

The operation of the relay 16 is controlled by a series circuit of a normally closed contact 19 of the relay 18 and a normally open contact 21 of the relay 20. The relay 18 is controlled by the output of the setting change monitoring circuit 22, and this circuit 22 monitors the torque setting value and the speed setting value, and when at least one of the both setting values changes, the relay 18 is turned on for a fixed time. To operate. The relay 20 is controlled by the output of the torque zero monitoring circuit 23, and this circuit 23 turns on the relay 20 when the detected torque value becomes substantially zero.

In such a configuration, in the normal control, the detected torque value deviates from the vicinity of zero, the relay 20 is turned off, and the relay 16 is turned off to hold the output contact 17 in the illustrated state. In this state, the torque control amplifier 6 has a high gain and obtains torque control maintaining the same high responsiveness as the conventional one.

Next, when the detected torque value is near zero, the zero torque monitoring circuit 23 detects zero torque and turns on the relay 20.
At this time, the contact 21 is closed, the relay 16 is turned on, the contact 17 is switched from the state shown in the figure, the torque control amplifier 6 is made to have a low gain, and the response due to the backlash of the sample is lowered, and the hunting and vibration due to the backlash occur. Suppress.

In the above control, the setting change monitoring circuit 22 turns on the relay 18 to open the contact 19 and restores the relay 16 when the torque setting value or the speed setting value changes. By this control, the torque control amplifier 6 is returned to the original high gain when the control such as changing the torque setting value is started from the low gain control state near the torque zero, and the control in which the high response is forced is obtained.

In the embodiment, the case of application to the control system on the power absorption side of the dynamometer is shown, but it is needless to say that this is applied to the drive control system and has the same effect.

Further, the switching means between the torque zero monitoring circuit 23 and the relay 20 for switching the torque control amplifier to a low gain, and the switching means between the setting change monitoring circuit 22 and the relay 18 for forcing the gain to the normal gain include the relay 16 and the switch 17. The design will be changed as appropriate.

G. Effect of the Invention As described above, according to the present invention, the torque control amplifier is switched from the normal gain to the low gain when the absorption torque or the driving torque for the sample becomes close to zero. This has the effect of suppressing the hunting phenomenon due to the backlash that it has, and returning the normal gain to the original normal value from the change monitoring of the control state to ensure test performance.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a transmission test apparatus. 6 ... Torque control amplifier, 17 ... Changeover switch, 22 ... Setting change monitoring circuit, 23 ... Torque zero monitoring circuit.

Claims (1)

[Scope of utility model registration request] 1. A dynamometer using a power transmission system as a specimen, a torque control amplifier capable of switching between a normal gain control state and a low gain control state for torque control of the specimen, and absorption or driving torque for the specimen. A first switching means for switching the torque control amplifier to a low gain control state when it is close to zero, and a second switching means for forcing the torque control amplifier to a normal gain when the control state for the specimen changes. Dynamometer characterized by having.