JPH08240132A - Crank angle position sensing device and recording/ reproducing method for crank angle position signal - Google Patents

Abstract

PURPOSE: To sense a crank angular position, revolving speed, and the like of an engine without influence of the dislocation of the initial setting. CONSTITUTION: A magnetic recording part is furnished with a rotary shaft 2 in such a way as capable of writing a crank angular position signal to represent the crank angular position corresponding to the piston position of at least one specific cylinder. and a magnetic head 19 is provided which is located in the position confronting the recording part and can at least reproduce the recorded crank angular position signal, and a sensing part is formed from the magnetic recording part and the magnetic head 19. A recording means 25 is provided to write the crank angular position signal in the magnetic recording part after assembly of engine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crank angle position detecting device for an engine, which is provided with a detecting portion for detecting a crank angle position corresponding to at least a piston position of a specific cylinder around a rotary shaft which is interlocked with a piston movement of the engine. And a method for recording / reproducing a crank angle position signal.

[0002]

2. Description of the Related Art Recently, in automobiles, by introducing electronic control of power train system including electronic fuel injection control of engine, it is necessary to meet social demands such as reduction of air pollution and reduction of fuel consumption. Became possible.

In order to realize such electronic control of the powertrain system, preparation and production of rotational position signals, rotational speed signals and cylinder discrimination signals of crankshafts and camshafts, which are rotary shafts interlocked with the piston movement of the engine, Detection is indispensable, and at the same time, the detection accuracy has a great influence on the power train system control accuracy.

Conventionally, a crank pulley portion of a crank shaft is provided with a plurality of protrusions (electromagnetic type) as shown in FIG. 7A or a plurality of holes (optical type) as shown in FIG. 7B. Plates are provided, electromagnetic pickups or optical pickups are arranged so as to face these plates, and crank angle position signals and rotation speed signals are detected and cylinder discrimination based on electrical signals detected by these electromagnetic pickups or optical pickups is performed. A crank angle sensor configured to perform is known.

Further, as disclosed in, for example, Japanese Unexamined Patent Publication No. 63-101708, a rotating body that rotates in synchronization with the crankshaft of an engine and has an appropriate number of unit angular magnetic poles formed on its circumferential surface. , A crank angle sensor provided with a magnetoelectric conversion means such as a Hall element fixedly arranged in the vicinity of this rotating body has also been proposed. In this crank angle sensor, a specific unit angular magnetic pole and another unit angular magnetic pole are provided. Cylinder discrimination is also performed by making the magnetic flux densities different from each other.

[0006]

By the way, in an engine equipped with the crank angle sensor having the above-mentioned structure, the detection accuracy of the crank angle position signal and the rotation speed signal depends on the shape and assembly of the plate or the rotating body. It is greatly affected by the mechanical accuracy of, and the positional deviation during assembly is particularly fatal.

However, the above-mentioned crank angle sensor has a problem that the positional deviation at the time of assembly, that is, the deviation of the initial set cannot be corrected.

In view of the above-mentioned circumstances, the present invention provides a crank angle position detecting device capable of detecting the crank angle position and the number of revolutions of an engine and the recording / reproducing of the crank angle position signal without being affected by the shift of the initial set. The purpose is to provide a method.

[0009]

SUMMARY OF THE INVENTION An engine crank angle position detecting device according to the present invention detects a crank angle position corresponding to at least a piston position of a specific cylinder around a rotary shaft which is interlocked with a piston movement of the engine. In a crank angle position detecting device for an engine including a magnetic recording unit, the detecting unit is a magnetic recording device provided on the rotating shaft, which is capable of writing a crank angle position signal indicating a crank angle position corresponding to at least a piston position of a specific cylinder. And a magnetic head capable of reproducing at least a crank angle position signal recorded in the magnetic recording unit, the magnetic head being disposed at a position facing the magnetic recording unit, and further, the crank angle position signal is generated after the engine is assembled. Recording means for writing to the magnetic recording portion is provided.

The magnetic head may have not only a signal reproducing function, but also a function capable of recording the crank angle position signal in the magnetic recording section, in which case the recording means is configured to record the magnetic field. It is configured to include a head.

It is possible to record a plurality of crank angle position signals of different types corresponding to each cylinder of the engine in the magnetic recording unit. Further, the plurality of crank angle positions of the specific cylinder can be recorded. It is also possible to record a plurality of crank angular position signals represented at equal intervals in the circumferential direction of the rotary shaft.

The magnetic recording portion can be provided on the peripheral surface of the rotary shaft, but is provided on the peripheral surface of a cylindrical body fitted around the rotary shaft in the vicinity of the bearing portion of the rotary shaft. Is also good.

Next, in the method of recording and reproducing the crank angle position signal according to the present invention, the crank angle position signal representing the crank angle position corresponding to at least the piston position of the specific cylinder is written on the rotary shaft that interlocks with the piston movement of the engine. A magnetic recording unit capable of performing the above, and a crank angle position signal is written in the magnetic recording unit by the recording means in association with the piston position of the specific cylinder after the engine is assembled. Reproduction is performed by a magnetic head arranged at a position facing the recording unit.

The recording means can be provided in an engine assembly line or an inspection line.

[0015]

The crank angle position detecting device according to the present invention is provided with a magnetic recording portion provided on the circumferential surface of the rotary shaft so that a crank angle position signal can be written, and a position facing the magnetic recording portion. Since a magnetic head capable of reproducing the generated crank angle position signal and recording means for writing the crank angle position signal in the magnetic recording unit after the engine is assembled, the deviation of the initial set can be prevented. It is possible to detect the crank angle position signal and the rotation speed signal without being affected, and thus it is possible to realize powertrain control with high control accuracy.

The magnetic head has not only a signal reproducing function but also a function of recording the crank angle position signal in the magnetic recording section.
The crank angle position detecting device can be made compact and the configuration can be simplified.

Further, by recording a plurality of different crank angle position signals corresponding to each cylinder of the engine in the magnetic recording section, cylinder discrimination can be performed with high accuracy.

Further, by recording a plurality of crank angle position signals representing a plurality of crank angle positions of a specific cylinder at equal intervals in the circumferential direction of the rotation shaft, it is possible to detect rotation fluctuation with high accuracy.

Further, by providing the magnetic recording portion on the peripheral surface of the cylindrical body fitted to the outer periphery of the rotary shaft in the vicinity of the bearing portion of the rotary shaft, the magnetic recording portion can be easily formed. At the same time, the fluctuation of the detection signal due to the eccentricity of the rotating shaft can be reduced. Further, in the crank angle position signal recording / reproducing method according to the present invention, since the crank angle position signal is written to the magnetic recording unit after the engine is assembled, the crank angle position signal is not affected by the shift of the initial set. Further, it becomes possible to detect the rotation speed signal, and thereby to realize powertrain control with high control accuracy.

In this case, by providing the recording means on the engine assembly line or the inspection line, it becomes unnecessary to provide the recording means on the engine side.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an in-line four-cylinder four-cycle engine equipped with a first embodiment of a crank angle position detecting device according to the present invention. In the figure, reference numeral 2 denotes a crankshaft of the engine 1, and five bearings 4 provided on a cylinder block 3 at predetermined intervals in the axial direction thereof.
Is rotatably supported by the crankshaft 2, and four pistons 5 are connected to the crankshaft 2 via connecting rods 6, respectively. Crankshaft 2 protruding from cylinder block 3
Crank pulley 7 for driving auxiliary equipment
And a timing pulley 9 for driving the camshaft 8, and a flywheel 10 is attached to the other end of the crankshaft 2. Cylinder head 11
The camshaft 8 provided on the camshaft pulley 1
A timing belt 1 having a camshaft pulley 12 and a timing pulley 9 mounted thereon.
The camshaft 8 is rotationally driven at a speed half the rotational speed of the crankshaft 2 via the valve 3, so that the valve 14 of each cylinder is driven.

The outer circumference of the crankshaft 2 is shown in FIGS.
As shown in, the cylindrical body 15 is fitted in the portion on the back side of the timing pulley 9. This cylindrical body 15
Has a magnetic recording layer 16 formed on its circumferential surface to form a magnetic recording portion, and has a key groove 2a formed on the crankshaft 2.
Is attached to the crankshaft 2 together with the timing pulley 9 via a key 17 inserted in
Further, it is fixed to the crankshaft 2 by bolts 18 together with the timing pulley 9. The mounting position of the cylindrical body 15 on the crankshaft 2 is preferably near the bearing 4 closest to the timing pulley 9.

On the other hand, a magnetic head is arranged on the front surface of the cylinder block 3 so as to face the magnetic recording layer 16 on the peripheral surface of the cylindrical body 15 and is capable of recording and reproducing signals on the magnetic recording layer 16. 19 is fixed via a mounting jig 20.

When the cylinder body 15 and the magnetic head 19 are assembled, after the engine body is assembled and the cylinder head 11 is assembled, the cylinder body 15 is first inserted into the tip of the crankshaft 2 and then the magnetic body is assembled. The magnetic head 19 is attached to the front surface of the cylinder block 3 via the attachment jig 20 so as to face the recording layer 16. In this case, as shown in FIG. 3, the magnetic head 19 has a thickness of about 10
A coating layer 21 of 0 μm of non-magnetic material is applied. The coating layer 21 is preferably made of a material, such as an epoxy resin adhesive, which is worn by contact with the rotating magnetic recording layer 16. Then, the magnetic head 19 is attached with the coating layer 21 in contact with the magnetic recording layer portion 16. By mounting the magnetic head 19 as described above, it is possible to reliably set the gap between the magnetic head 14 and the magnetic recording unit 13 that affects the detection accuracy of the magnetic signal to about 100 μm.

After the cylinder body 15 and the magnetic head 19 have been assembled in this way, the timing pulley 9 and the timing belt 13 are attached and the cylinder body 15 and the timing pulley 9 are bolted in accordance with the normal engine assembly procedure. After fixing with, the crank pulley 7 may be assembled with the bolt 22. The electric signal line 23 led from the magnetic head 19 is led to the outside through a small hole 24 a provided in the timing belt cover 24.

The magnetic head 19 has a recording signal output circuit 25 for recording a pulsed magnetic signal on the magnetic recording layer 16 and a magnetic signal recorded on the magnetic recording layer 16 and reproduced by the magnetic head 19. A rotation speed detection circuit 26 and a code identification circuit 27, which output a rotation speed signal and a crank angle position signal, respectively, based on the signal, are connected.

Next, the recording procedure of the magnetic signal on the magnetic recording layer 16 will be described.

FIG. 4 shows the relationship between the recording signal recorded on the magnetic recording layer 16 and the piston position of the # 1 cylinder. In this embodiment, one magnetic pulse signal is used as the signal corresponding to the top dead center (TDC) position of the # 1 cylinder (FIG. 4A), and the signal corresponding to the 90 ° position after the top dead center (ATDC) of the # 1 cylinder. 2 magnetic pulse signals (FIG. 4B), three magnetic pulse signals corresponding to the 180 ° position after the top dead center of the # 1 cylinder (FIG. 4C), and 270 ° position after the top dead center of the # 1 cylinder. There are four magnetic pulse signals as signals corresponding to (FIG. 4D).

FIG. 5 is a flow chart showing the recording procedure of the magnetic signal.
It is a chart. First, the crankshaft 2 is rotated so that the piston position of the # 1 cylinder corresponds to the top dead center position (S1). In this state, the recording signal output circuit 25
To output an electric pulse signal to the magnetic head 19 to record a pulsed magnetic signal on the magnetic recording layer 16 via the magnetic head 19 (S2). Next, it is determined whether or not the required number of magnetic pulse signals have been recorded (S3). At this position, one magnetic pulse signal may be recorded, so the determination in S3 is YES, but the determination in S4 is Because it becomes NO, S1
Then, the crankshaft 2 is rotated to align the piston position of the cylinder # 1 with the 90 ° position after top dead. In this state, an electric pulse signal is output from the recording signal output circuit 25 to the magnetic head 19 as before, and a pulsed magnetic signal is recorded on the magnetic recording layer 16 via the magnetic head 19 (S2). Since it is necessary to record two pulse-shaped magnetic signals at this position, the magnetic signals are similarly recorded after rotating the crankshaft 2 by about 1 ° (S5) (S2).
By performing this operation a necessary number of times, the magnetic signal shown in FIG. 4 can be recorded in the magnetic recording layer 16 (S4: YES).

Next, the procedure for detecting the rotation speed signal and the crank angle position signal by the magnetic signal recorded in the above procedure will be described.

A rotation speed detection circuit 26 for detecting a rotation speed signal
The operation of is as follows. That is, to obtain a signal for each revolution of the crankshaft 2, one pulse-shaped magnetic signal corresponding to the compression top dead center position of the # 1 cylinder is sent to the magnetic head 1.
The time detected through 9 is measured by a timer. In order to obtain a signal for every 90 ° of the crankshaft 2, a timer measures the time for detecting the first pulsed magnetic signal recorded at each position.

The operation of the code identification circuit 27 for detecting the crank angle position signal is as follows. That is, when the magnetic head 19 detects one pulse-shaped magnetic signal,
Output a signal indicating that it is the top dead center position of the # 1 cylinder,
When two pulsed magnetic signals are detected, a signal indicating that the # 1 cylinder is at a 90 ° position after top dead center is output, and 3
When the number of pulse-shaped magnetic signals is detected, a signal indicating that the position is 180 ° after the top dead center of the # 1 cylinder is output.
When one pulse-shaped magnetic signal is detected, a signal indicating that the position is 270 ° after the top dead center of the # 1 cylinder is output.

As described above, according to the first embodiment of the crank angle position detecting apparatus of the present invention, the rotation speed signal and the crank angle position signal can be detected without being affected by the shift of the initial set.

Next, a second embodiment of the crank angle position detecting device according to the present invention will be described with reference to FIG. 6 corresponding to FIG. In this embodiment, the camshaft pulley 12
A cylindrical body 15 'having a magnetic recording layer as a magnetic recording portion formed on its peripheral surface is attached to the camshaft 8 on the rear side of
As in the first embodiment, the magnetic head 19 is arranged so as to face the magnetic recording layer. Since other configurations are the same as those in FIG. 1, the portions corresponding to those in FIG. 1 are designated by the same reference numerals, and the duplicated description will be omitted. However, in the present embodiment, the crankshaft 2 rotates at a speed half that of the crankshaft 2. Since the magnetic recording layer is provided on the camshaft 8, it becomes possible to record the magnetic signal at the position corresponding to the compression top dead center of each cylinder in the magnetic recording layer, which allows the rotation speed signal and the crank signal to be recorded. In addition to the detection of the angular position signal, the cylinder discrimination signal can be detected.

Furthermore, a third embodiment in which the first and second embodiments are combined is also conceivable. That is, in this embodiment, the magnetic recording portion and the magnetic head are provided on both the crankshaft 2 and the camshaft 8, respectively.

The feature of the present embodiment is that magnetic signals are recorded in both magnetic recording portions at the same timing, whereby this embodiment is the same as the first and second embodiments. Of course, it has the function provided, but when there is no deviation in the rotation of the crankshaft 2 and the camshaft 8, the magnetic signal can be detected at the same timing. On the other hand, for example, when a metal piece or the like is caught between the camshaft pulley 12 and the timing belt 13 and the timings of the two are delicately deviated from each other, the signals detected by the two magnetic heads are deviated. Therefore, when this deviation is detected, an alarm is given that the timing deviation has occurred between the crankshaft 2 and the camshaft 8, and the correction of the timing deviation is controlled within a controllable range based on this deviation time. Can be done.

In the above embodiment, the cylindrical body 15 or 15 'having the magnetic recording layer formed on the peripheral surface is provided.
When the cylindrical body is fitted to the crankshaft 2 and / or the camshaft 8 and the cylindrical body is made of a magnetic material, the peripheral surface of the cylindrical body is used as a magnetic recording portion without a magnetic recording layer. It is also possible to record magnetic signals directly,
Further, it is also possible to directly record the magnetic signal on the crankshaft 2, the camshaft 8 or the crank pulley which is a magnetic material.

Further, although the magnetic head 19 for both recording and reproduction is used in the above-described embodiment, the magnetic head is attached to the engine at a position where it can be replaced, and then the engine assembly line or inspection is performed. In the line, after recording the magnetic signal in the magnetic recording section using the recording-only magnetic head, remove the recording-only magnetic head,
A magnetic head dedicated to reproduction or a magnetoelectric conversion element such as a Hall element or a magnetoresistive element may be attached to the same position to detect a magnetic signal.

As is apparent from the above description, according to the crank angle position detecting device for an engine and the crank angle position signal recording / reproducing method shown in the above-mentioned embodiment, the crank angle position detecting device and the crank angle position signal recording / reproducing method are provided on the rotary shaft which is interlocked with the piston motion of the engine. The magnetic recording unit uses the magnetic head to record and reproduce the magnetic signal after the engine is assembled, so that the crank angle position signal and the engine speed signal can be received without being affected by the deviation of the initial set. Etc. can be detected, which enables the control of the power train with excellent control accuracy.

[Brief description of drawings]

FIG. 1 is a first crank angle position detecting device according to the present invention.
Schematic configuration diagram showing an embodiment of

FIG. 2 is an enlarged vertical sectional view of a main part of FIG.

FIG. 3 is an enlarged sectional view taken along line III-III in FIG.

FIG. 4 is an explanatory view showing a recording procedure of a magnetic signal on a magnetic recording layer.

FIG. 5 is a flowchart showing a recording procedure of a magnetic signal on a magnetic recording layer.

FIG. 6 is a second crank angle position detecting device according to the present invention.
Schematic configuration diagram showing an embodiment of

FIG. 7 is a front view of a rotating plate included in a conventional crank angle sensor.

[Explanation of symbols]

 1 Engine 2 Crankshaft 3 Cylinder Block 4 Bearing 5 Piston 8 Camshaft 9 Timing Pulley 11 Cylinder Head 12 Camshaft Pulley 13 Timing Belt 15 Cylindrical Body 16 Magnetic Recording Layer 19 Magnetic Head 20 Magnetic Head Mounting Jig

Claims (8)

[Claims] 1. A crank angle position detection device for an engine, comprising: a detection unit for detecting at least a crank angle position corresponding to a piston position of a specific cylinder around a rotation axis interlocking with a piston movement of the engine. Is a magnetic recording unit provided on the rotary shaft capable of writing a crank angle position signal representing at least a crank angle position corresponding to a piston position of a specific cylinder;
The magnetic recording unit is arranged at a position facing the magnetic recording unit, and is composed of a magnetic head capable of reproducing at least the crank angle position signal recorded in the magnetic recording unit. Further, the crank angle position signal is magnetically recorded after the engine is assembled. A crank angle position detecting device for an engine, characterized in that a recording means for writing to the section is provided. 2. The magnetic head also has a function of recording the crank angle position signal in the magnetic recording portion, and the recording means includes the magnetic head. Crank angle position detection device for the engine described. 3. The crank of an engine according to claim 1, wherein a plurality of crank angle position signals of different types corresponding to respective cylinders of the engine are recorded in the magnetic recording unit. Angular position detection device. Position detection device. 4. A plurality of crank angle position signals representing a plurality of crank angle positions of the specific cylinder are recorded in the magnetic recording section at equal intervals in the circumferential direction of the rotary shaft. Alternatively, the crank angle position detecting device for the engine according to the item 2. 5. The crank angle position detecting device for an engine according to claim 1, wherein the magnetic recording unit is provided on a peripheral surface of the rotating shaft. 6. The magnetic recording portion is provided on the peripheral surface of a cylindrical body fitted around the outer periphery of the rotary shaft in the vicinity of the bearing portion of the rotary shaft. The crank angle position detection device for the engine according to any one of 1. 7. A magnetic recording unit capable of writing a crank angle position signal representing at least a crank angle position corresponding to a piston position of a specific cylinder is provided on a rotary shaft that is interlocked with a piston movement of an engine, and the magnetic recording unit is provided in the magnetic recording unit. On the other hand, after the engine is assembled, the crank angle position signal is written by the recording means in correspondence with the piston position of the specific cylinder,
A method for recording / reproducing a crank angle position signal, characterized in that the crank angle position signal is reproduced by a magnetic head arranged at a position facing the magnetic recording section. 8. The method for recording / reproducing a crank angle position signal according to claim 7, wherein the recording means is provided on an assembly line or an inspection line of the engine.