KR100273554B1 - Cylinder position determining system and engine revolution number calculation method - Google Patents

Abstract

PURPOSE: A cylinder distinguishing apparatus of a cylinder and a method for calculating engine rpm by using the same are provided to distinguish the cylinder all section angle of a cam shaft regardless of a reference signal. CONSTITUTION: A cylinder distinguishing apparatus of a cylinder includes a disc(2) mounted to be rotated by being accompanied with a cam shaft(1) and different in the distance from a predetermined point outside the outer peripheral surface to the outer peripheral surface according to the operation range of each cylinder, a distance sensor(3) mounted at the predetermined point outside the outer peripheral surface and sensing the distances for outputting, a counter(4) performing count operation if the distances are uniform and outputting data with resetting the data if the distances are changed, and an engine control unit(5) recognizing the point when the data is input at the counter as cylinder change, and calculating engine rpm by using count period, data, and the output signal of the distance sensor.

Description

Cylinder discrimination device and engine speed calculation method using the cylinder

1 is a block diagram showing a cylinder cylinder discriminating apparatus according to an embodiment of the present invention,

2 is an output signal waveform diagram of a sensor and a counter shown in FIG.

3 is a flowchart illustrating a method for calculating an engine speed according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

1: Camshaft 2: Disc

3: distance sensor 4: counter

5: engine control unit

The present invention relates to a cylinder cylinder judging device and a method for calculating the engine speed using the same, and more specifically, a disc formed to be thresholded by a predetermined distance according to the cylinder of each cylinder to rotate along with a cam shaft, and detected by a sensor. The present invention relates to a cylinder cylinder discrimination device and a method for calculating an engine speed using the same, wherein the cylinder is counted and reset according to the distance to the disc, and the engine speed can be calculated based on the count value.

According to the techniques known to date, the angle measurement and cylinder discrimination method of the engine crankshaft are performed by angle grooves and cylinder discrimination by digging grooves on the rotating disks along with the camshaft or the crankshaft or forming gear teeth around the disks. I am trying to.

That is, the sensor input consists of two types of information such as high or low when measuring / discriminating, and the engine control unit (ECU) performs angle measurement and cylinder determination using this input signal. do.

By the way, the cylinder discrimination method currently used as described above can be cylinder identification only at a predetermined range of angles of the camshaft by the combination of the angle detection signal and the cylinder identification signal. In addition, when a sensor that outputs a reference signal is broken, the above known technology has a problem that it is impossible to determine a cylinder.

Therefore, an object of the present invention is to solve the conventional technical problems as described above, the disk is made to be rotated along the camshaft, the shape of the disk is formed so that the distance detected by the sensor according to the cylinder cylinder, and the sensor A cylinder cylinder judging device using the distance sensed by the cylinder cylinder determination and engine speed calculation information and an engine speed calculation method using the same are provided.

As a means for achieving the above object, the configuration of the cylinder cylinder discriminating device according to the characteristics of the present invention is mounted to rotate along the camshaft, the distance from the predetermined point outside the outer peripheral surface to the outer peripheral surface according to the operating range of each cylinder A disc made of a shape such that (D1, D2, D3, D4) are different; A distance sensor mounted at a predetermined point outside the outer circumferential surface of the disc and sensing and outputting distances (D1, D2, D3, D4) to the outer circumferential surface of the disc; A counter for performing a count operation when the distance sensed by the distance sensor is constant, and outputting a count value up to that time and resetting the count value when the distance changes; And an engine control unit for recognizing that there is a cylinder change at the time when the count value is input from the counter, and calculating the engine speed using the count period, the count value, and the output signal of the distance sensor.

In the above configuration of the present invention, the disc is fixed to the cam shaft such that the point of change of the distance from the center to the outer circumferential surface is the top dead center of each cylinder.

Further, as a means for achieving the above object, the configuration of the engine speed calculation method according to the features of the present invention comprises the first step of fetching the increment period (T) of the counter from the internal timer of the engine control unit; ; A second step of inputting a count value Data input from the counter; A third step of calculating a time TE for one revolution of the engine crankshaft by using the increment period T fetched in the first step and the count value Data input in the second step; And a fourth step of calculating the number of revolutions per minute of the crankshaft by using the time TE for one revolution of the engine crankshaft calculated in the third step.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a cylinder cylinder discriminating apparatus according to an embodiment of the present invention. FIG. 2 is a waveform diagram of output signals of the sensor and counter shown in FIG. 1, and FIG. It is a flowchart explaining the engine speed calculation method which concerns on an example.

First, with reference to FIG. 1, the structure of the cylinder cylinder discriminating apparatus which concerns on embodiment of this invention is demonstrated.

As shown in FIG. 1, the cylinder cylinder discriminating apparatus according to the embodiment of the present invention is mounted to rotate along with the camshaft 1, and the distance D1, from each of the four outer peripheral surfaces divided into quarters, is determined. A disc 2 formed such that D2, D3, and D4 are different from each other; A distance sensor 3 installed at a predetermined point outside the outer circumferential surface of the disc 2; A counter 4 connected to receive an output signal of the distance sensor 3; And an engine control unit 5 connected to receive the output signal of the counter 4 and the distance sensor 3.

The disc 2 is fixed to the camshaft 1 such that a change point of the distances D1, D2, D3, D4 from a predetermined point outside the outer circumferential surface becomes a top dead center (TDC) of each cylinder.

Next, the operation of the cylinder cylinder discriminating apparatus according to the embodiment of the present invention will be described with reference to the configuration of FIG. 1 and the waveform diagram of FIG.

When the operation of the engine starts, the cam shaft 1 rotates in association with the rotation of the crankshaft, and the disc 2 also rotates with the cam shaft 1.

In the sensor 3, the distances D1, D2, D3, and D4 from a predetermined point outside the outer circumferential surface of the disc 2 to the outer circumferential surface are detected, and a signal relating to the detected distance is output to the counter 4.

The point of change of the distances D1, D2, D3, and D4 shown in FIG. 1 is the top dead center of each cylinder and is the starting point of the explosion stroke. In addition, the four change points indicate the first cylinder, the third cylinder, the fourth cylinder and the second cylinder in the clockwise direction, respectively. This arrangement is because the explosion of each cylinder is performed in the same order as described above.

(A) of FIG. 2 shows the waveform of the signal output from the distance sensor 3, and the output signal of the sensor 3 changes according to the distances D1, D2, D3, D4 to the outer circumferential surface. Is showing.

The counter 4 performs an up count operation while the output signal of the distance sensor 3 is kept constant, and performs a reset operation when there is a change in the output signal of the distance sensor 3. . At this time, the counter 4 outputs the count value at that time to the engine control unit 5 together with the reset.

(B) of FIG. 2 shows the count state of the counter 4.

The engine control unit 5 determines the cylinder of the cylinder every time the output value of the counter 4 is input, and sets the control reference angle from the signal output from the distance sensor 3. That is, when the output signal of the distance sensor 3 is within a predetermined range, the control reference angle can be set by recognizing it as the top dead center of the first cylinder.

Next, an engine speed calculation method according to an embodiment of the present invention will be described with reference to the configuration of FIG. 1 and the flowchart of FIG. 3.

When the operation is started (S1), the increment period T of the counter 4 is fetched from the timer inside the engine control unit 5 (S2). This increment period T is the time taken when the counter 4 performs one count operation.

Next, a counter value Data is input from the counter 4 (S3). This count value Data is consequently the time it takes for one cylinder to operate.

Using the increment period T and the count value Data of the step S2, a time TE for the engine to rotate 1 is calculated (S4). Equation for calculating the time (TE) for the engine to rotate 1 is as follows.

TE = 2 × T × Data

For reference, the embodiment of the present invention assumes application to a four-cylinder engine, and in a four-cylinder engine, since the camshaft rotates once when the crankshaft rotates in two revolutions, the crankshaft rotates once by the explosion stroke of two cylinders. can do. The T × Data is the time taken for one cylinder to perform an explosive stroke, so by doubling this to the outer circumferential surface, the time (TE) for the engine to make one revolution can be obtained.

Next, the revolution per minute (RPM) of the engine is calculated using the time TE for one revolution of the engine obtained in the step S4 (S5), and the equation is as follows.

RPM = 60 / TE

When the revolutions per minute is calculated as described above, the operation of the engine speed calculation method according to the embodiment of the present invention is completed (S6), and control is returned to return to the main program.

As described above, according to the embodiment of the present invention, all section angles of the cam shaft are performed by performing cylinder discrimination and engine speed calculation by the distance detected by the disc 2 and the sensor 3 rotating along the cam shaft. In addition to the determination of cylinders, the cylinders can be distinguished independently of the reference signal. In addition, the software implementation for calculating the engine speed is simplified, and it is easy to check the failure of the cylinder discrimination sensor.

Claims (3)

A disc mounted to rotate along the camshaft, the disc being shaped such that distances (D1, D2, D3, D4) from a predetermined point outside the outer circumferential surface to the outer circumferential surface differ according to the operating range of each cylinder; A distance sensor mounted at a predetermined point outside the circumferential surface of the disc and sensing and outputting distances (D1, D2, D3, D4) to the outer circumferential surface of the disc; A counter for performing a count operation when the distance detected by the distance sensor is constant, and outputting a count value up to that time and resetting the count value when the distance changes; Recognizing that there is a change in cylinder when the count value is input from the counter, characterized in that it comprises an engine control unit for calculating the engine speed using the count cycle, the count value and the output signal of the distance sensor Cylinder discrimination device. 2. The cylinder cylinder discrimination apparatus according to claim 1, wherein the disc is fixed to the cam shaft such that a change point of the distance from the center to the outer circumferential surface is a top dead center of each cylinder. Fetching an increment period T of the counter from the internal timer of the engine control unit; A second step of inputting a count value Data input from the counter; A third step of calculating a time TE for one revolution of the engine crankshaft by using the increment period T fetched in the first step and the count value Data input in the second step; And a fourth step of calculating the number of revolutions per minute of the crankshaft by using the time (TE) of one revolution of the engine crankshaft calculated in the third step.