JP3912467B2 - Engine crank angle sensor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a crank angle sensor for detecting the rotational position of a crankshaft of an engine.
[0002]
[Prior art]
When an engine such as an automobile is electronically controlled, it is necessary to accurately detect the rotational position of the crankshaft in order to use it as a base for fuel injection timing, ignition timing, cylinder discrimination, and the like. Therefore, conventionally, for example, an annular sensor plate having equidistant teeth on the outer peripheral portion is attached so as to rotate integrally with the crankshaft, and a sensor body such as a pickup coil is opposed to the outer peripheral teeth of the sensor plate. A crank angle sensor is known which is fixed and obtains a rotational position of a crankshaft by detecting an electric pulse signal generated by rotation of a sensor plate.
[0003]
[Problems to be solved by the invention]
By the way, in such a crank angle sensor, the clearance between the sensor plate and the sensor body (usually about 0.8 mm to 1.3 mm) needs to be accurately taken. However, the sensor plate is arranged in the crankcase and When the sensor body is fixed to the side wall of the cylinder block so as to face each other, the facing portion between the sensor plate and the sensor body cannot be visually observed. For this reason, the accuracy of the clearance depends on the mounting dimensions of the sensor plate and the sensor body, and there is a problem that it is difficult to manage the accuracy of the clearance.
[0004]
The present invention has been made in view of the above points, and an object of the present invention is to provide an engine crank angle sensor in which the clearance from the sensor plate can be visually observed after the sensor body is assembled. .
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 is directed to a sensor plate attached so as to rotate integrally with a crankshaft, and a sensor body fixed to the side wall of the cylinder block so as to face the outer periphery of the sensor plate. An engine crank angle sensor for detecting the rotational position of the crankshaft, wherein the sensor plate is attached to the crankshaft so as to rotate integrally with the crankshaft, and a partition partitioning the crankcase An opening facing the facing portion between the sensor plate and the sensor body is provided.
[0006]
With this configuration, in the engine assembly process, the clearance between the sensor plate and the sensor body can be visually observed through the opening provided in the partition wall of the crank chamber.
[0007]
According to a second aspect of the present invention, in the configuration of the first aspect, the sensor plate is disposed at a position adjacent to the timing chamber in the crank chamber, and the opening is formed in an end wall of the cylinder block on the timing chamber side. It is provided.
[0008]
With this configuration, the clearance between the sensor plate and the sensor body can be visually observed through the opening provided in the end wall of the cylinder block.
[0009]
According to a third aspect of the present invention, in the configuration of the first or second aspect, the opening is a blow-by gas passage.
[0010]
Blow-by gas flows through an opening provided in the partition wall in the crank chamber and the timing chamber.
[0011]
According to a fourth aspect of the present invention, there is provided the sensor according to any one of the first to third aspects, wherein the sensor is disposed near a center of a region surrounded by the crankshaft and a central axis of an engine accessory driven by the crankshaft. The main body is arranged.
[0012]
With such a configuration, it is possible to effectively use the dead space between the engine accessories.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
A first embodiment will be described with reference to FIGS. 1 to 3 show the vicinity of the crankshaft on the timing mechanism side (the opposite side of the flywheel) of the engine according to this embodiment. Reference numeral 1 denotes a cylinder block, 2 denotes a crankshaft, 3 denotes a bearing cap, 3A , 3B are bolts for attaching the bearing cap to the cylinder block 1, 4 is a cylinder liner, 5 is a piston, 6 is a connecting rod, 7 is a water jacket, and 8 is an oil pan (shown only in FIGS. 2 and 3). Yes.
[0014]
A timing sprocket 9 is attached to the end of the crankshaft 2 projecting from the end of the cylinder block 1, and the timing sprocket 9 drives a valve mechanism (not shown) of an intake / exhaust valve of the cylinder head. A timing chain 10 is wound around. At the end of the cylinder block 1, a timing cover 11 (FIG. 1) covers a timing mechanism comprising a timing sprocket 9, a timing chain 10 and a cam sprocket (not shown) of a valve mechanism around which the timing chain 10 is wound. In FIG. 2, only a part is shown by being broken, and a timing chamber 12 is formed in the timing cover 11.
[0015]
The tip of the crankshaft 2 is inserted into the timing cover 11 and drives an oil pump 13 provided integrally with the timing cover 11. A crank pulley 14 is attached to the tip of the crankshaft 2 that protrudes outward from the timing cover 11. As shown in FIG. 1, a water pump 15 (engine auxiliary machine) is integrally provided on the side of the end face of the cylinder block 1 on the timing mechanism side, and the side of the cylinder block 1 below the water pump 15 is provided. Is attached with an alternator 16 (engine accessory) via a bracket 16A (only part of which is shown in FIG. 1). A V belt 19 is wound around the crank pulley 14, the water pump pulley 17 and the alternator pulley 18, and the water pump 15 and the alternator 16 are driven by the crankshaft 2.
[0016]
Next, the configuration of the crank angle sensor 20 will be described. The crank angle sensor 20 includes a disk-shaped sensor plate 21 that rotates integrally with the crankshaft 2, and a sensor main body 22 that detects the rotation of the sensor plate 21. Sensor plate 21, in the thus formed crankcase to the cylinder block 1 and the oil pan 8, the crankshaft 2 No. No. 1 journal 23 (the journal closest to the timing chamber 12), that is, No. 1 journal. 1 journal 23 and counterweight No. It is attached between one web 24 (the web closest to the timing chamber 12) and rotates integrally with the crankshaft 2. The sensor plate 21 has a diameter larger than that of the crankpin 25 of the crankshaft 2 and the counterweight web, and the outer peripheral portion extends to the vicinity of the inner wall of the crank chamber. A plurality of sensor plates 21 are provided at predetermined intervals (eight in the illustrated example). The external teeth 26 are projected. A plurality of lightening holes 21a are provided for weight reduction.
[0017]
The sensor body 22 of the crank angle sensor 20 is mounted on the side wall of the cylinder block 1 so that the pickup portion 27 faces the outer periphery of the sensor plate 21 with a predetermined clearance (usually about 0.8 mm to 1.3 mm). It is inserted through the hole 28 and attached by a bolt 30 using a bracket 29. Further, the sensor body 22 is disposed substantially at the center of the region surrounded by the respective central axes of the crankshaft 2, the water pump 15, and the alternator 16. The sensor body 22 can output an electrical pulse signal in accordance with the rotation of the sensor plate 21 using, for example, a pickup coil.
[0018]
As shown in FIGS. 4 to 6, the crank chamber in the cylinder block 1 has four crank chambers 34a, 34b, 34c, 34d communicating with each cylinder bore by three partition walls 31, 32, 33 (see FIG. 6). It is divided into. The end wall 35 (partition wall) on the timing chamber 12 side of the cylinder block 1 is provided with a bearing portion 36 that supports the No. 1 journal 21 of the crankshaft 2, and the partition walls 31, 32, and 33 each have a crankshaft. No.2 to No.4 bearings 37, 38 and 39 for supporting No.2 to No.4 journals (not shown) are provided, and the end wall 40 on the flywheel side is provided with a crankshaft. A No. 5 bearing portion 41 for supporting the No. 5 journal (not shown) is provided.
[0019]
The partition walls 31, 32, 33 of the cylinder block 1 are provided with blow-by gas passages 42, 43, 44 for communicating the crank chambers 34 a, 34 b, 34 c, 34 d with each other, and an end wall on the timing chamber 12 side. 35 is provided with a blow-by gas passage 45 that allows the crank chamber 34a and the timing chamber 12 to communicate with each other. The blow-by gas passage 45 of the end wall 35 is disposed at a position facing a facing portion between the sensor plate 21 attached to the crankshaft 2 and the sensor main body 22 attached to the attachment hole 28. The blow-by gas passages 42, 43, 44, 45 are arranged on the same axis along the axial direction of the crankshaft 2.
[0020]
Next, the operation of the present embodiment configured as described above will be described.
When the crankshaft 2 rotates, the sensor body 22 outputs an electrical pulse signal according to the rotation of the sensor plate 21 that rotates integrally with the crankshaft 2, and the rotational position of the crankshaft 2, that is, the crank angle is detected based on this pulse signal. can do.
[0021]
Further, in the engine assembly process, the opposing portion between the sensor plate 21 attached to the crankshaft 2 and the sensor main body 22 attached to the cylinder block 1 passes through the blow-by gas passage 45 provided in the end wall 35 of the cylinder block 1. Visible from the outside. Thereby, the clearance C between the sensor plate 21 and the sensor main body 22 can be easily confirmed visually or using a gap gauge or the like, and the clearance can be easily managed. Then, for example, that more be adjusted with the mounting position adjustment screws or shims or the like of the sensor main body 22 to the cylinder block 1 of the mounting hole 28, to accurately adjust the clearance C between the sensor plate 21 and the sensor body 22 Can do.
[0022]
Furthermore, the sensor main body 22 is arranged at substantially the center of the region surrounded by the central axis of the crankshaft 2, the water pump 15 and the alternator 16, so that the dead space between these engine accessories can be effectively utilized. And space efficiency can be improved. Further, by arranging the blow-by gas passages 42, 43, 44, 45 on the same axis along the axial direction of the crankshaft 2, the blow-by gas passages 42, 43, 44, 45 can be easily processed.
[0023]
Next, a second embodiment of the present invention will be described with reference to FIGS. Since the second embodiment is generally similar in structure to the first embodiment except that the type of cylinder block is different, hereinafter, the same reference numerals are given to the same parts as those of the first embodiment. In addition, only different parts will be described in detail.
[0024]
The engine according to the first embodiment uses a deep skirt type cylinder block, whereas the engine according to the second embodiment has a half skirt type cylinder block as shown in FIGS. Is used. As shown in FIGS. 7 and 8, in the engine according to the second embodiment, a lower case 46 having a bearing portion 46a for supporting the journal of the crankshaft 2 is coupled to the lower portion of the cylinder block 1A. The oil pan 8 is coupled, and a crank chamber is formed by the cylinder block 1A, the lower case 46, and the oil pan 8. With this configuration, the same functions and effects as those of the first embodiment can be obtained.
[0025]
In the first and second embodiments, the sensor plate 21 and the sensor body 22 of the crank angle sensor 20 are arranged in the crank chamber 34a closest to the timing chamber 12, but these are the other timing chambers 34b, It is also possible to confirm the clearance C from the blow-by gas passage 42, 43 or 44 provided in the partition wall 31, 32 or 33 by being arranged at 34c or 34d.
[0026]
Moreover, although the said 1st and 2nd embodiment demonstrated what drives the water pump 15 and the alternator 16 with the crankshaft 2, this invention is not limited to this, Other engine auxiliary machines instead of these The present invention can be similarly applied to a device that drives.
[0027]
【The invention's effect】
As described above in detail, according to the invention of claim 1, the partition wall dividing the crank chamber, by providing an opening opposite the portion facing the sensor plate and the sensor body, in the assembly process of the engine, crankcase Since the clearance between the sensor plate and the sensor body can be visually observed through the opening provided in the partition wall, the clearance between the sensor plate and the sensor body can be easily confirmed visually or using a gap gauge or the like. Can be easily managed.
[0028]
According to the second aspect of the present invention, in the configuration of the first aspect, the sensor plate is disposed at a position adjacent to the timing chamber in the crank chamber, and the opening is provided in the end wall on the timing chamber side of the cylinder block. The clearance between the sensor plate and the sensor body can be visually observed through the opening in the end wall of the cylinder block.
[0029]
According to the third aspect of the invention, in the configuration of the first or second aspect, the blow-by gas passage in the crank chamber and the timing chamber can be circulated through the opening provided in the partition wall by using the blow-by gas passage as the opening.
[0030]
According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the sensor main body is disposed near the center of the region surrounded by the crankshaft and the central axis of the engine accessory driven by the crankshaft. By arranging, the dead space between engine auxiliary machines can be used effectively and space efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a front view showing a partially cutaway end portion of a timing chamber side of an engine according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a side surface in the vicinity of a timing chamber of the engine of FIG.
3 is a side view on the opposite side of FIG. 2 near the timing chamber of the engine of FIG.
4 is an end view of the cylinder block of the engine of FIG. 1 on the timing chamber side.
FIG. 5 is an enlarged view of a main part of FIG. 4;
6 is a bottom view showing a partially broken cylinder block of the engine of FIG. 1. FIG.
FIG. 7 is a partially cutaway front view showing an end portion on the timing chamber side of an engine according to a second embodiment of the present invention.
8 is a longitudinal sectional view of a side surface near a timing chamber of the engine of FIG.
[Explanation of symbols]
1 Cylinder block
1A Cylinder block 2 Crankshaft
12 Timing room
15 Water pump (engine accessory)
16 Alternator (engine accessory)
20 Crank angle sensor
21 Sensor plate
22 Sensor body
35 End wall (partition wall)
45 Blow-by gas passage (opening)

Claims (4)

An engine crank for detecting the rotational position of a crankshaft comprising a sensor plate mounted to rotate integrally with the crankshaft and a sensor body fixed to the side wall of the cylinder block so as to face the outer periphery of the sensor plate An angle sensor, wherein the sensor plate is attached so as to rotate integrally with the crankshaft in a crank chamber, and an opening is provided in a partition wall that partitions the crank chamber so as to face a facing portion between the sensor plate and the sensor body. An engine crank angle sensor.   The engine crank according to claim 1, wherein the sensor plate is disposed at a position adjacent to the timing chamber in the crank chamber, and the opening is provided in an end wall of the cylinder block on the timing chamber side. Angular sensor.   The engine crank angle sensor according to claim 1 or 2, wherein the opening is a blow-by gas passage.   The engine crank according to any one of claims 1 to 3, wherein the sensor main body is arranged near the center of a region surrounded by the crankshaft and a central axis of an engine accessory driven by the crankshaft. Angular sensor.

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