JP2003172194A - Cylinder discriminating device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for cylinder discrimination of a cylinder discriminating device for an internal combustion engine. <P>SOLUTION: The cylinder discriminating device for the internal combustion engine is provided with a camshaft having a first signal member, a cam sensor arranged near a camshaft, a crankshaft having a second signal member, and a crank angle sensor arranged near a crankshaft. A plurality of generating parts for cam signals detectable by the cam sensor are provided on the first signal member, a plurality of generating parts for crank angle signals detectable by the crank angle sensor are provided on the second signal member, and a discriminating means is provided for carrying out the cylinder discrimination by an existence pattern of the cam signals detected between the continuously generated crank angle signals when the crankshaft rotates twice. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder discriminating apparatus for an internal combustion engine, and more particularly, to a cylinder discriminating apparatus for an internal combustion engine which shortens the time required for cylinder discrimination as compared with a conventional apparatus. It concerns the device. 2. Description of the Related Art An internal combustion engine mounted on a vehicle or the like generally has a plurality of cylinders, and any one of the cylinders is used to control ignition timing, fuel injection timing, and the like of each cylinder. It is necessary to determine whether. A cylinder discriminating apparatus for discriminating a cylinder of an internal combustion engine having a plurality of cylinders is disclosed in
There are those disclosed in Japanese Patent Application Laid-Open Nos. 1-311147 and 11-31148. [0003] Japanese Unexamined Patent Publication No. 11-31147 discloses a signal member mounted on a camshaft,
A cylinder determining device for a multi-cylinder engine having a plurality of concave groups or convex groups formed on the signal member and a crank angle sensor, wherein the concave groups or convex groups include the number of the groups of the engine. The number of cylinders is set to be the same as the number of cylinders, and the number of concave portions or convex portions is set to different numbers. A cylinder angle is determined by detecting a signal based on the group of concave portions or convex portions with a crank angle sensor. Japanese Unexamined Patent Application Publication No. 11-31148 discloses a crank angle which is disposed opposite to a first signal member and a second signal member mounted on a camshaft and opposed to the first signal member and the second signal member. Sensor and a cam sensor, the first signal member includes the same number of concave or convex groups as the number of cylinders of the engine, and one of the concave or convex groups determines the number of the concave or convex parts. The number is different from the number of the other groups, and the second signal member has the same number of valve opening / closing timing concave portions or convex portions as the number of cylinders of the engine, and transmits a signal based on the first signal member and the second signal member. The cylinder is determined by detecting the crank angle sensor and the cam sensor. [0005] In a conventional cylinder discriminating apparatus for an internal combustion engine, a cylinder discrimination of 2.0 to 2.0 is required.
There is a disadvantage that 2.5 rotations are required and the time required for cylinder determination becomes longer, and as a result, the starting time becomes longer. In an internal combustion engine provided with a variable valve timing mechanism (also referred to as "VVT") for varying the valve timing of intake and exhaust valves, the camshaft also has a cam sensor and a pattern (or "teeth"). Provided, but only used to control cam timing. SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides a camshaft having a first signal member, a cam sensor disposed near the camshaft, and a second camshaft. In a cylinder discriminating apparatus for an internal combustion engine including a crankshaft having a signal member and a crank angle sensor disposed near the crankshaft,
The first signal member is provided with a plurality of cam signal generators that can be detected by a cam sensor, the second signal member is provided with a plurality of crank angle signal generators that can be detected by a crank angle sensor, When rotating, a discriminating means for discriminating a cylinder based on a presence / absence pattern of a cam signal detected between continuously generated crank angle signals is provided. [0008] The invention as described above,
When the crankshaft makes two rotations, the discriminating means performs cylinder discrimination based on the presence / absence pattern of a cam signal detected between successively generated crank angle signals. , The starting time is shortened, and the erroneous determination when the engine speed fluctuates greatly is eliminated. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 to FIG. 5 show an embodiment of the present invention. 3, 2 is an internal combustion engine, 4 is a cylinder block, 6 is a cylinder head, 8 is a head cover,
Is an oil pan. This internal combustion engine 2 has a plurality of cylinders,
In this embodiment, three of the first cylinder # 1 to the third cylinder # 3
It has a cylinder, and is provided with an air cleaner 12, a throttle body 14, an intake pipe 16, and an intake manifold 18 as an intake system, and an exhaust manifold 20, a catalytic converter 22, an exhaust pipe 24, and a muffler 26 as an exhaust system. The internal combustion engine 2 supports a crankshaft 28 on a cylinder block 4, an intake camshaft 30 and an exhaust camshaft 32 on a cylinder head 6, and a crank pulley 3 on one end of the crankshaft 28.
4, an intake cam pulley 36 and an exhaust cam pulley 38 are provided at one end of each of the intake camshaft 30 and the exhaust camshaft 32, and a timing chain (not shown) wound around the crank pulley 34, the intake cam pulley 36, and the exhaust cam pulley 38, The intake camshaft 3 is synchronized with the rotation of the crankshaft 28 by a timing belt or the like.
0 and the exhaust camshaft 32 is rotated. The internal combustion engine 2 is provided with a cylinder discriminating device 40. The cylinder discriminating device 40 includes the intake camshaft 3
A first signal member 42 is provided on one end side of the zero using an intake cam pulley 36, and a cam sensor 44 for detecting a cam signal from the first signal member 42 is provided. At this time, the cam sensor 44 is provided with a variable valve timing mechanism (“V
VT) (not shown). As shown in FIG. 1, the signal of the cam sensor 44 is a conventional two signal (see signal a and signal b) 17.5.
The signal c is added at a position delayed by CA degrees and delayed by 120 degrees CA from the signal a. A current cam sensor (for cylinder determination, ignition, and injection control) (also referred to as "sensor 2 (VVT)")
Is set such that only one cycle of the signal is shorter than the other signals, and the signal position of this short cycle is determined by a predetermined cylinder, for example, the second cylinder #
2 is determined. In such a case, it is necessary to sense a signal of a predetermined short cycle and a signal of another long cycle, and a time of 240 ° CA to 890 ° CA is required. Further, the cylinder discriminating device 40 is provided with a second signal member 50 using a crank pulley 34 at one end side of the crankshaft 28.
Crank angle sensor 52 for detecting a crank angle signal from 0
Is provided. The advance control of a variable valve timing mechanism (not shown) (also referred to as "VVT") can be used similarly to the conventional one. When the crankshaft 28 makes two rotations, there is provided a discriminating means 54 for discriminating a cylinder based on the presence / absence pattern of a cam signal detected between successive crank angle signals. More specifically, the second signal member 50 has six teeth for generating the signal pattern of the crank angle sensor 52, and the signal pattern of the cam sensor 44 generated between the signals of the crank angle sensor 52. Is determined, cylinder discrimination is performed between 240 ° CA and 600 ° CA. That is, the second signal member 50 includes:
As shown in FIG. 5, six first to sixth crank angle signal generators 56-1 to 56-6 are provided. At this time, the first to sixth crank angle signal generators 56-1 to 56-6 are set to a 70-degree CA interval and a 50-degree CA
The first, third, and fifth crank angle signal generators 56-1, 56-3, 56-5 are arranged so that the intervals are alternated.
75 ° CA signal before top dead center of each cylinder, that is, # 1-
75, # 2-75, # 3-75, and the second,
Fourth and sixth crank angle signal generators 56-2, 56-4,
56-6 is a signal of 5 degrees CA before the compression top dead center of each cylinder, that is, # 1-5, # 2-5, and # 3-5, and is used as an ignition reference. Next, the operation will be described. The internal combustion engine 2 includes a crankshaft 28
The intake camshaft 30 and the exhaust camshaft 32 are rotated in synchronization with the rotation of, and the intake and exhaust valves, not shown, are opened and closed. As shown in FIG. 1, the cylinder discriminating device 40 uses a crank angle sensor 52 to detect six first to sixth crank angle signals of a second signal member 50 provided at one end of the crankshaft 28. Generators 56-1 to 56-6
, Ie, # 1-75 ·
# 1-5, # 2-75, # 2-5, # 3-75, # 3-
5 is detected. The signals detected by the cam sensor 44 and the crank angle sensor 52 are input to a discriminating means 54. The determination means 54 determines the cylinder based on the signal pattern of the cam sensor 44 detected between successive crank angle signals when the crankshaft 28 makes two rotations. That is, as shown in FIG. 1, when the signal pattern of the cam sensor 44 when the crankshaft 28 makes two rotations is "10010", it is determined to be # 3-75, that is, the third cylinder # 3. The shortest crank angle required for cylinder discrimination at this time is 360 ° CA (1.0 rotation), and the longest crank angle is 480 ° CA
(1.33 rotations). When the signal pattern of the cam sensor 44 is "0000", it is determined to be # 2-75, that is, the second cylinder # 2. The shortest crank angle required for cylinder discrimination at this time is 290 ° CA (0.81 rotation), and the longest crank angle is 600 ° CA (1.
67 rotations). Further, when the signal pattern of the cam sensor 44 is "X1010" (X: arbitrary), # 1-7
5, that is, the first cylinder # 1 is determined. The shortest crank angle required for the cylinder discrimination at this time is 240 ° CA
(0.67 rotations) and the longest crank angle is 530 degrees CA (1.47 rotations). Thus, when the crankshaft 28 makes two rotations, the presence / absence pattern of the cam signal of the cam sensor 44 detected between the successively generated crank angle signals differs for each cylinder. The cylinder discrimination can be performed between the degrees CA to 600 ° CA, and the time required for the cylinder discrimination can be reduced and the start time can be reduced as compared with the conventional one. Also, since the cylinder discrimination is performed based on the number of cam signals from the cam sensor 44, even if the engine speed greatly changes, no erroneous determination is made and the reliability can be improved. It is practically advantageous. It should be noted that the present invention is not limited to the above-described embodiment, and various application modifications are possible. For example, in the embodiment of the present invention, the pattern of the cam sensor and / or the crank angle sensor, that is, the position and the number of teeth may be changed. In the embodiment of the present invention, the first signal member is provided at one end of the intake camshaft of the internal combustion engine by utilizing the intake cam pulley. However, the first signal member is provided at the exhaust cam pulley of the exhaust camshaft. A special configuration in which members are provided is also possible. Furthermore, it is also possible to adopt a special configuration in which a signal member is provided for each of the intake cam pulley of the intake camshaft and the exhaust cam pulley of the exhaust camshaft of the internal combustion engine. That is, when a signal member is provided on each of the intake cam pulley of the intake camshaft and the exhaust cam pulley of the exhaust camshaft, the position where the signal member is formed is shifted. Then, it is possible to discriminate the cylinder in a short time from the signal patterns on both the intake camshaft side and the exhaust camshaft side, which is practically advantageous. Further, in the embodiment of the present invention,
Although the first signal member is provided on one end side of the intake camshaft of the internal combustion engine using the intake cam pulley, a special configuration in which the first signal member is provided on another shaft portion interlocked with the crankshaft is also possible. It is. That is, for example, the first signal member is provided in an oil pump, a water pump, an alternator, and other auxiliary shaft parts. By providing the first signal member in the auxiliary shaft portion, the degree of freedom of layout when providing the first signal member is increased, and the first signal member is provided.
It is intended to improve the attachment of the signal member. It is also possible to provide a small structure in which a small pulley is provided on the intake cam pulley of the intake camshaft and the cylinder is distinguished for each rotation of the small pulley. That is, for example, the small pulley is formed to have a size corresponding to one cycle, and the first rotation of the small pulley is determined to be the third cylinder, and the second rotation of the small pulley is determined to be the second cylinder. Then, the third cylinder is sequentially distinguished from the first cylinder at the third rotation. In this case, by performing the cylinder discrimination (discrimination of the cylinder in the compression stroke state) for each rotation of the small pulley, the cylinder discrimination can be easily performed, and the usability can be improved. As described above in detail, according to the present invention, a camshaft having a first signal member, a cam sensor disposed near the camshaft, and a crank having a second signal member In a cylinder discriminating apparatus for an internal combustion engine including a shaft and a crank angle sensor disposed near the crankshaft, a plurality of cam signal generators that can be detected by a cam sensor are provided on the first signal member. A plurality of crank angle signal generation units detectable by a crank angle sensor are provided on a two-signal member, and a presence / absence pattern of a cam signal detected between continuously generated crank angle signals when the crankshaft makes two rotations Is provided, a crank angle signal generated continuously when the crankshaft makes two rotations is provided. The presence / absence pattern of the cam signal of the cam sensor detected between the cylinders differs for each cylinder.
The time required for cylinder determination can be shortened, and the starting time can be shortened. In addition, since the cylinder discrimination is performed based on the number of cam signals of the cam sensor, even if the engine speed fluctuates greatly, erroneous determination is not performed, reliability can be improved, and practically advantageous. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing cylinder discrimination based on a cam signal and a crank angle signal of a cylinder discrimination device according to an embodiment of the present invention. FIG. 2 is a diagram showing angles required for cylinder discrimination. FIG. 3 is a schematic configuration diagram of a cylinder discriminating device of an internal combustion engine. FIG. 4 is a front view of a first signal member. FIG. 5 is a front view of a second signal member. DESCRIPTION OF SYMBOLS 2 Internal combustion engine 12 Air cleaner 14 Throttle body 16 Intake pipe 18 Intake manifold 20 Exhaust manifold 22 Catalytic converter 24 Exhaust pipe 26 Muffler 28 Crankshaft 30 Intake camshaft 32 Exhaust camshaft 34 Crank pulley 36 Intake cam pulley 38 Exhaust cam pulley 40 cylinder discriminating device 42 first signal member 44 cam sensor 46-2, 46-3 second and third cylinder cam signal generating unit 48 specific cylinder discriminating cam signal generating unit 50 second signal member 52 crank angle sensor 54 discriminating means 56 -1 to 56-6 First to sixth crank angle signal generator

Claims (1)

Claims: 1. A camshaft having a first signal member, a cam sensor disposed near the camshaft,
In a cylinder discriminating device for an internal combustion engine including a crankshaft having a second signal member and a crank angle sensor disposed near the crankshaft, a plurality of cam signals detectable by a cam sensor are provided in the first signal member. A plurality of crank angle signal generators which can be detected by a crank angle sensor in the second signal member, and detects between successive crank angle signals when the crankshaft rotates twice. A cylinder discriminating device for an internal combustion engine, comprising a discriminating means for discriminating a cylinder based on a presence / absence pattern of a cam signal.