JPH0358068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine rotational fluctuation detection device that is capable of detecting rotational irregularities within one rotation of an engine and analyzing angular velocity, torque, etc. within one rotation.

Automotive engines undergo various performance tests during the manufacturing process, and only those that pass the tests are shipped. Among these engine performance tests is a rotational fluctuation test. The rotational fluctuation test is for measuring the degree of smoothness of engine rotation, and is the most important engine performance test. Conventionally, in order to detect engine rotational fluctuations, the engine was rotated for a predetermined period of time, appropriate processing was performed, and then the rotational fluctuation rate was calculated, which made testing time-consuming.

The present invention has been made in view of these points, and it modulates clock pulses using TDC pulses and crank angle pulses generated from the engine body, and alternately counts the modulated clock pulses with an up-down counter. However, the present invention realizes a rotational fluctuation detection device that can detect rotational fluctuations of the engine from the integrated count value of the counter, and can detect rotational irregularities and the like with just one rotation of the engine.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is an electrical configuration diagram showing an embodiment of the present invention. In the figure, 1 is a clock pulse generator that generates high frequency pulses of about 1MHz to 10MHz, _F1 to _F4 are R/S (reset/set) flip-flops, _G1 to _G3 and _G6 are AND gates,
G ₄ , G ₅ , G ₇ are OR gates, and 2 is an up-down counter. The start pulse is a pulse that sets the circuit to the initial state, and the OR gates G ₄ , G ₅ ,
input to flip-flops F ₁ , F ₂ and F ₃ via G ₇ , and some directly to flip-flop F ₄
and is input to the up-down counter 2.
A TDC (Top Death Center) pulse is a pulse that is output once every rotation of the engine, and a crank angle pulse is a pulse that is output once every 1 degree rotation of the engine. Therefore, 360 crank angle pulses are output per engine revolution. T.D.C.
Pulses and crank angle pulses are generated by a pulse encoder 5 mounted on the shaft 4 of the engine 3, as shown in FIG.

The TDC pulse is input to the set input S of the flip-flop _F1 and the OR gate _G4 , and the crank angle pulse is input to the ungate _G1 . The Q output of flip-flop _F1 is the S output of flip-flop _F2 .
Input and input to or gate G ₅ , or gate G ₅
The output of is input to the R (reset) input of _F2 . The output of AND gate G ₁ is a flip-flop
Input to S input of F ₃ and F ₄ and OR gate G ₇
is also entered. The output of _G7 is input to the R input of _F3 . On the other hand, the clock pulse is output from the clock pulse generator 1 and is output from the AND gate G ₆
is being input. The other input of G ₆ has the Q of F ₄
The output is the input, and the output of G ₆ is the AND gate G ₂ , G ₃
are entered respectively. The Q output and output of F ₃ are input to the other inputs of G ₂ and G ₃ , respectively. The output of G ₂ is input to the down input D of counter 2,
The output of _G3 is input to the up input U of counter 2, respectively. The operation of the device configured in this way will be explained below.

Figure 3 shows TDC pulse P ₁ and crank angle pulse P ₂
FIG. 4 is a timing chart showing the relationship between the crank angle pulse _P2 and the clock pulse _P3 . TDC pulse
The period T ₁ of P ₁ is the time required for one rotation of the engine, and the period T _{2 of the crank angle pulse P 2 is} the time corresponding to ₁ degree of engine rotation angle. In Figure 1,
When the start pulse is applied, the flip-flop
_F1 to _F4 and the up-down counter 2 are reset and set to the initial state. Then TDC
A pulse is generated, and the Q output of flip-flop _F1 becomes "1", and the Q output of _F2 , which receives the Q output, also becomes "1". When the Q output of _F2 becomes "1" and the gate _G1 opens, the first crank angle pulse passes through the gate and the flip-flop
Set the Q output of each of F ₃ and F ₄ to “1”. As a result of the Q output of _F4 becoming "1", gate _G6 is activated and the clock pulse passes through the gate. That is, the flip-flop _F4 and the gate _G6 prevent the clock pulse from being applied to the gates _G2 and _G3 before the first crank angle pulse after the start pulse is applied.

The clock pulse that passed through gate G ₆ is the gate
It passes through _G2 and is input to the up input U of counter 2, where it is added and counted. The same clock is also input to gate _G3 , but _the output of _F3 (="0")
is closed, so the down input D of counter 2
There is no need to enter it. Next, when the second crank angle pulse is generated, this pulse is input to the reset input R of _F3 and resets the flip-flop, so Q becomes "0" and Q becomes "1".
This time, the gate _G3 is opened and input is input to the down input D of the counter 2 for subtraction counting. Since gate _G2 is closed, no clock is input to the U input of counter 2. In this way, repeat the same operation for the 3rd and 4th shots, and count the counter 2.
The difference for every 1 degree of engine rotation angle is accumulated. The counter 2 stores data corresponding to 360 TDC pulses, that is, one revolution of the engine. If the engine does not have uneven rotation or fluctuations in rotational speed, the number of clocks entering the up input U of the clock pulses input to counter 2 and the number of clocks entering the down input should always be the same every 1 degree. , the cumulative value of the counter 2 for one rotation of the engine is 0. The fact that the contents of the counter 2 after one rotation of the engine is not 0 means that some kind of rotational fluctuation has occurred in the engine.
The contents of this counter are sent to a CPU (not shown) and subjected to arithmetic processing to determine rotational unevenness, rotational speed fluctuation rate, and the like. For example, if the number of data stored in the counter 2 after one revolution is N, then the rotational unevenness corresponds to N/360. After data processing is completed, a start pulse is sent out again as necessary to perform a measurement operation. In the present invention, data regarding engine rotational fluctuations is obtained during one revolution of the engine. Therefore, engine performance tests can be performed at high speed.

The frequency of the clock pulse is determined by the rotational speed of the engine, and is 1 to 10MHz as described above.
That's about it. In the above explanation, one TDC pulse is output for every 1° of engine rotation angle. This method can be applied even in such cases. For example, if one crank angle pulse occurs at x°, the rotational unevenness is N/(360/x)
It can be calculated as corresponding to

As explained above in detail, according to the present invention, the clock pulse is modulated by the TDC pulse generated from the engine body and the crank angle, the modulated clock pulse is alternately calculated by the up-down counter, and the integrated value is It is possible to realize an engine rotational fluctuation detection device that can detect rotational irregularities and the like with only one revolution of the engine.

[Brief explanation of drawings]

FIG. 1 is an electrical configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the mounting position of a pulse encoder, and FIGS. 3 and 4 are timing charts showing the relationship between each pulse. 1... Clock pulse generator, 2... Up-down counter, 3... Engine, 4... Axis, 5... Pulse encoder, _F1 to _F4 ... R/S flip-flop,
G ₁ ~ _{G 3} , G ₆ ... and gate, G ₄ , G ₅ ... or gate.

Claims (1)

[Claims] 1 The clock pulse is modulated by the TDC pulse and crank angle pulse generated from the engine body, and the clock pulses counted within a time interval synchronized with the crank angle pulse are counted alternately by an up-down counter, and the accumulated value is calculated from the clock pulse. An engine rotational fluctuation detection device capable of detecting rotational fluctuation within one revolution of the engine.