JPS59105911A - Phase difference detecting device for internal- combustion engine - Google Patents

Abstract

PURPOSE:To detect an accurate phase difference between a crankshaft and a camshaft by a method wherein pulse generators are respectively arranged on the camshaft and on the crankshaft and the phase difference is calculated from the interval between the adjoining pulses of said pulse generators and the rotational frequency of an engine. CONSTITUTION:A pulse generator, which generate a pulse every time a crankshaft makes a turn, consists of an indicator piece 62 on a crankshaft 10 and a magnetic sensor 64 facing to the piece 62 and a pulse generator, which generates a pulse every time a camshaft makes a turn, consists of an indicator piece 66 on a camshaft 18 and a magnetic sensor 68 facing to the piece 66. The two magnetic sensors 64 and 68 are connected through wires 70 and 72 to a control circuit 74, which has a function to calculate the phase difference based upon the pulse signals from said pulse generators. The sensor 68 on the camshaft 18 issues one signal every time the sensor 68 faces to the indicator piece 66 correctly during one turn of the camshaft. Similarly, the sensor 64 on the crankshaft 10 issues one signal every time the sensor 64 faces to the indicator piece 64 correctly during one turn of the crankshaft. Consequently, the phase difference is detected and can be accurately measured by measuring the time interval between the adjoining pulses and the rotational frequency of an engine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase difference detection device that is used in a variable pulp timing device of the type that alters pulp timing by shifting the phase of a camshaft relative to a crankshaft.

There is a pulp timing control device proposed by the present applicant in which a pair of slits are provided adjacent to an inner sleeve on the camshaft side and an outer sleeve on the timing sleeve side. The pair of slits are arranged in directions that are inclined to each other, and a roller bearing is installed within the slit. The roller bearing is supported by a cylindrical moving body that is movable in the camshaft direction. The rotary drive motor is connected to the movable body through a rotary motion-linear motion conversion means consisting of a threaded portion on its output shaft and a nut engaged with the threaded portion. Depending on the direction of rotation of the motor, the intersecting slit inner roller bearing moves f4 in the camshaft direction, which causes the pair of sleeves to rotate relative to each other. As a result, the pulp timing changes between the motor's rotation limit position in one direction and the rotation pole position in the other direction for 1 hour.
”, and changes in multiple stages.

With this Yuzu variable pulp timing device, it is necessary to know exactly how far the camshaft is turned relative to the flang/curve. The present invention has been made in response to such a request, and in order to achieve the object of the patent, which is characterized by providing a device for detecting a net phase difference between a shift flank shaft and a camshaft, the present invention provides a device for detecting a net phase difference between a shift flank shaft and a camshaft. Pulse generators are provided at the cranks 1+l+, and means are provided for calculating the phase difference from the spacing between adjacent pulses of these pulse generators and the engine rotating string.

The following will be explained with reference to Figure 1: 1 is the cylinder block, 2 is the cylinder head 1♂, 3t is to the cylinder, the rear cover, 4 is the intake pipe, 6 is the throttle valve, and 8 is the exhaust noise. 10 is a crankshaft, and a connecting rod 12 is connected to a piston 14. Cam 2 on camshaft 18
0 is formed, and the cam 20 acts against the valve spring 26 on the intake valve 24 and the air intake valve 25 via the rocker arm 22.23. A timing pulley 28 is positioned at one end of the cam 1lill 18 for a relative rotation of 1'',
It is wound around a pulley 32 on the crankshaft 10 via a timing belt 30. The timing pulley 28 and the camshaft 18 are the valve timing control device 3 according to the present invention.
It is concluded by 4.

The structure of the pulp multi-timing control device 34 is shown in the second part. Is the inner sleeper 36 connected to one end of the camshaft 18? It is fixedly installed by a bolt 37. Is it the timing mentioned above?
U 28 is mounted on this inner sleeve 36 by bearings 39. An outer sleeve 38 extends coaxially with the inner sleeve 36 from the boss portion of the timing pulley 28 . The inner sleeve 36 and the outer sleeve 38 have adjacent slits 40 and 42. As shown in Figure 3, one side 40 is straight, but the other side 40 is straight.
2 are slanted, and as a result, they intersect with each other. Bearings 44 and 46 are located within the slits 40 and 42, respectively. The bearings 44 and 46 are pivotally supported by a shaft portion 48'l that integrally extends in the radial direction from a cylindrical moving body 48 that reciprocates along the direction of the camshaft.

Reference numeral 50 is a step motor, which is connected to the movable body 48 via rotational motion-linear motion conversion means.

This means is constructed as a so-called recirculating kale screw. That is, the output shaft 50'l of the motor 50
The nut 52 has an external thread, and the nut 52 has an endless internal thread, and a ball 54 is located between these threads. Nine guided outer parts 51 extend from the housing of the motor 50.
Cam shaft direction guide formed on the putt 52: J￥52
’ is fitted. From such ladle J coin, motor 50
It will be clear that the rotational movement of the power meter 150' is converted into a linear movement of the nut 52. The nut 52 is connected to the moving body 48 via a bearing 60, and
4 and 46 are driven in the camshaft direction.

62 is a case and one end is 7J? The timing pulley 28 is fixed to the hub portion of the timing pulley 28 by a bolt 64, and the other end is rotatably connected to the motor housing by a bearing 66. Reference numeral 68 denotes a timing belt cover which houses the timing belt 30 and also includes the pulp timing control device of the present invention.

During cranking, 1100 rotations are transmitted to the timing pulley 28 via the timing pulley 32 and the timing belt 30. The rotation of the timing pulley 28 is transmitted to the shaft portion 48' via a roller bearing 46 located within a slit 42 of an outer sleeve 36 integral with the timing pulley 28. The rotation of the shaft portion 48' is transmitted to the inner sleeve 38 through the roller bearing 44 located within the slit 40, and the camshaft 18 is rotationally driven. When the cam 20 on the camshaft 18 reaches the peak, it pushes the stem of the valve 24.25 via the rocker arm 22.23, and the valve spring 26
The valves 24 and 25 are opened against this.

When the step motor 50 is driven, its output shaft 50'
rotates, and the nut 52 moves in the direction A or B in FIG. Therefore, the roller bearings 44 and 46 provided on the shaft of the movable body 48 that move together with the nut 52 also move in the respective slots 40 and 42 in the same direction. The slits 40 and 42 intersect with each other as shown in FIG.
The linear motion of the inner sleeve 46 and the outer sleeve 38 in the camshaft direction is converted into relative rotation of the inner sleeve 46 and the outer sleeve 38 in the direction C or D in FIG. Therefore, the outer sleeve 38 on the driving side of the camshaft 18 connected to the inner sleeve 38 on the driven side, that is, the timing pulley 2
8 Furthermore, the rXγ phase I'' with respect to the crankshaft 10 changes by 1. Therefore, the pulp timing, which is the crank angular displacement 1i= when the cam 20 acts on the pulp 24°25, changes af. The position of the movable body 48 in the axial direction is determined depending on the rotation angle of the step motor 50 from the reference position.

It is clear that with the above structure, it is possible to obtain valve timing that changes continuously in accordance with the rotation of the motor 50. 11' There is something that the mouse must know. For this reason, we have installed the following detection equipment.

First, a detection piece 62 made of a magnetic material is provided at a rectangular position of the crank 4U+10, and a magnetic sensor 64 is provided facing this, which generates a pulse for each rotation of the crankshaft. Configure the generator. On the other hand, Kamusuke 1
Similarly, a detection piece 66 made of a magnetic material is also placed at a predetermined position on the top 8.
A magnetic sensor 68 is provided facing the magnetic sensor 68, and a magnetic sensor 68 is provided facing the magnetic sensor 68.
Configure a pulse generator. The magnetic sensors 64 and 68 for these two pulse generators 2 are connected to a control circuit 74 via lines 7o and 72 7'L. The control circuit 74 has the function of a computer programmed to calculate the phase difference based on the pulse signal from the pulse generator, and has a configuration as shown in FIG. 4 in the block diagram. That is, the magnetic sensors 64 and 68 are connected to the input port 80 and the output port 82 is connected to the motor 50 via the motor control circuit 84. The input and output ports 82 are the components of the converter system, including a path 87 to a microprocessing unit 82 (MPU), a 'J-only memory 84 (ROM), and a random access memory 86 (M). are connected via.

88 is a clock signal generator (CLOCK). R.O.
The M84 stores software for detecting a phase difference according to the present invention.

The sensor 68 of the camshaft 18 outputs a signal once per revolution as shown in FIG. 5(a) every time it directly faces the detection piece 66. Similarly, the center t64 of the crankshaft 1o outputs a signal as shown in FIG.

In the present invention, the time interval between adjacent pulses is measured and the engine rotational speed and phase difference are detected by software. This software is stored as a program in the ROM84. This program will be explained below with reference to the flowchart shown in FIG.

100 indicates the start of this routine, which is an interrupt routine executed at predetermined intervals. When an interrupt request is applied to the interrupt port of the MPU 82, the flag f is first verified at 102. This flag f is a flag that is set while measuring the phase difference and is set down when the measurement is completed. non-tears
If the standard width is tL, the flag is 0, and the judgment of 102 is NO.
becomes. Therefore, 104104K. At 104, Cam In
It is determined whether the signal from the sensor 68 that detects the detection piece 66 on l118 is on the rise or not.If NO, nothing is done, but if Yes (time tl in FIG. 5), the timer TI is set at 108. is set. Then, at 110, flag f is set.

When the next interrupt routine begins execution, the determination in 102 is Yes.
It becomes s. Next, at 112, it is determined whether the signal from the sensor 64 that detects the detection piece 62 on the crankshaft 10 is a signal that has been detected. If NO, nothing will be done, but Ye8 (4th
If it is time tz ) in the figure, the value of the timer T1 at that time is stored in the NT area of the RAM 86 at step 114. The value of this timer is the time interval between adjacent mother routes (a) and (b). In the next step 116, the phase difference CR is calculated from the engine rotational speed Ne at that time and the above NT. This CR is stored in a predetermined area of the RAM 86 and used for pulp timing switching control. Club f at 118
or will be reset.

According to the present invention described above, a means for generating a pulse r is provided for each rotation of the camshaft and crankshaft, and the distance between the adjacent pulses from each pulse generating means and the engine rotation speed are determined. Accurate phase difference can be measured.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an internal combustion engine equipped with the phase difference detection device of the present invention; Fig. 2 is a vertical sectional view showing an example of the UJ variable valve timing mechanism; Figure 4 shows the control circuit professional, and Figure 5 shows the two A? Fig. 6 is a flowchart showing the phase difference calculation software Fig. 10...Crankshaft, 18...Camshaft, 62...
Detection piece, 64...Magnetic sensor, 66...Detection piece, 6
8... Magnetic sensor, 74... Control circuit. Patent Applicant: Toyota Motor Corporation Patent Application Agent: Akira Aoki, Patent Attorney: Kazuyuki Nishidate, Patent Attorney: Yasushi Tsuchiyama, Patent Attorney: Akira Tsuchiyama, Patent Attorney: Figure 1

Claims (1)

[Scope of Claims] A device for detecting a phase difference between a crankshaft and a camshaft of an internal combustion engine, comprising: a first pulse signal generating means that generates a full pulse signal for each revolution of the crankshaft; a second pulse signal generating means that generates an A' pulse signal every time; a means for measuring the interval between adjacent pulse signals between the first pulse signal generating means and the second A' pulse signal generating means; A phase difference detection device consisting of: