JP7124684B2 - crankshaft device - Google Patents

Description

The present invention relates to a crankshaft device.

Conventionally, there has been proposed a torsional damper in which a drive plate is integrated with a crankshaft of an engine (see, for example, Patent Document 1).

JP 2004-218694 A

When adding a dynamic damper function to the rear end of the crankshaft to reduce engine vibration, from the viewpoint of cost and mounting space constraints, rather than installing a new part and adding a dynamic damper function, the existing Adding a dynamic damper function to the part is more realistic. In this case, it is conceivable to add a dynamic damper function to the flywheel or drive plate in order to suppress bending resonance of the crankshaft. However, considering the necessary inertia, material, diameter, thickness, etc., it is necessary to adjust the resonance frequency of the dynamic damper function to a high frequency band such as 1 kHz to 2 kHz, which corresponds to the bending resonance of the crankshaft, in flywheels and drive plates. is difficult.

A main object of the crankshaft device of the present invention is to provide a crankshaft device capable of suppressing bending resonance of the crankshaft and reducing vibration of the engine.

The crankshaft device of the present invention employs the following means in order to achieve the above main object.

The crankshaft device of the present invention includes:
A crankshaft device comprising a rotation sensor including a sensor plate that rotates integrally with a crankshaft of an engine and a detector that detects a plurality of teeth of the sensor plate,
Having a mass provided on the outer periphery of the sensor plate,
The sensor plate and the mass are configured to have a dynamic damper function with a resonance frequency substantially matching the bending resonance frequency of the crankshaft.
This is the gist of it.

The crankshaft device of the present invention includes a rotation sensor including a sensor plate that rotates integrally with the engine crankshaft and a detector that detects a plurality of teeth of the sensor plate. In this crankshaft device, a mass is provided on the outer periphery of the sensor plate, and the sensor plate and the mass are configured to have a dynamic damper function with a resonance frequency substantially matching the bending resonance frequency of the crankshaft. By providing the mass body on the outer peripheral portion of the sensor plate, the sensor plate and the mass body can function as a dynamic damper by utilizing the spring action of the sensor plate in the surface tilt direction. As a result, it is possible to provide a crankshaft device capable of suppressing bending resonance of the crankshaft and reducing vibration of the engine. Here, the resonance frequency of the dynamic damper can be adjusted mainly by adjusting the spring constant of the sensor plate in the tilt direction and the inertial mass of the mass body in the tilt direction. Further, the spring constant of the sensor plate in the tilt direction can be adjusted by forming an adjustment hole in the sensor plate.

In such a crankshaft device of the present invention, the plurality of teeth of the sensor plate protrude in the axial direction, and the detector has a detection surface that is substantially perpendicular to the tooth tips of the plurality of teeth of the sensor plate. It is good also as what is arranged so that it may face. In this way, even if the sensor plate runs out, it is possible to suppress a change in the gap between the detection surface of the detector and the tooth portion, and it is possible to suppress the occurrence of detection failure of the rotation sensor.

1 is a cross-sectional view of a crankshaft device 10 as an embodiment of the invention; FIG. 4 is a front view of the base plate 20; FIG. 3 is a front view of a toothed plate 30; FIG. 4 is a partial perspective view of a toothed plate 30; FIG. FIG. 4 is an explanatory diagram showing an example of crank bending resonance; FIG. 4 is an explanatory diagram showing the relationship between vibration acceleration and frequency of each crankshaft device of an example and a comparative example; FIG. 5 is an explanatory diagram showing how the gap between the toothed plate 30 and the detection element 40 changes with three-node bending resonance of the crankshaft. FIG. 11 is a cross-sectional view of a crankshaft device 110 of a modified example; It is a cross-sectional view of a crankshaft device 210 of a modified example. 4 is a partial perspective view of sensor plate 230. FIG.

Next, a mode for carrying out the present invention will be described using examples.

1 is a cross-sectional view of a crankshaft device 10 as an embodiment of the present invention, FIG. 2 is a front view of a base plate 20, FIG. 3 is a front view of a toothed plate 30, and FIG. 4 is a partial perspective view of the toothed plate 30. FIG. The crankshaft device 10 includes a crankshaft 12 of an engine (for example, an in-line four-cylinder engine) (not shown) as a prime mover mounted on a vehicle, a base plate 20, a toothed plate 30, a detection element 40, and a mass ring (inertia ring). ) 50; An oil seal 16 seals between the inner peripheral surface of the opening of the cylinder block 14 through which the crankshaft 12 passes and the outer peripheral surface of the crankshaft 12 . Further, the rear end of the crankshaft 12 is connected to a torque converter to which power is to be transmitted via a drive plate or the like.

The base plate 20 is formed by pressing a flexible plate material (metal plate). As shown in FIG. 2, the base plate 20 has a flat disk-shaped connecting portion 21 provided in the center, and a flat disk-shaped connecting portion 21 protruding from the connecting portion 21 to the opposite side of the crankshaft 12 on the outer peripheral side of the connecting portion 21. and a flat annular portion 23 .

A plurality of (six in the embodiment) connecting holes 22 are formed in the connecting portion 21 at regular intervals in the circumferential direction. A plurality of (four in the embodiment) fixing holes 24 are formed in the annular portion 23 at regular intervals in the circumferential direction. A plurality of (four in the embodiment) adjustment holes 25 are formed in the annular portion 23 at regular intervals in the circumferential direction out of phase with the fixing holes 24 .

The toothed plate 30 is formed by pressing a plate material (metal plate). This toothed plate 30 constitutes a sensor plate together with the base plate 20, and as shown in FIGS. and a tubular portion 34 extending toward the block 14 . A plurality of teeth 35 projecting in the extending direction are formed on the tubular portion 34 at regular intervals in the circumferential direction. The plurality of tooth portions 35 has, for example, 34 teeth with two missing teeth.

The detection element 40, together with the sensor plate (the base plate 20 and the toothed plate 30), constitutes a rotation sensor that detects the rotation position and rotation speed of the crankshaft 12. For example, it is configured as an MR (Magneto Resistance) sensor. . The detection element 40 is fixed to the cylinder block 14 so that its detection surface faces perpendicularly to the tip of the tooth portion 35 of the toothed plate 30 .

The crankshaft 12 of the engine and the connecting portion 21 of the base plate 20 are fastened together by bolts inserted through the connecting holes 22 . The annular portion 23 of the base plate 20 and the annular portion 32 of the toothed plate 30 are connected to each other by rivets R inserted through the fixing holes 24 and 33 .

The mass ring 50 has a flat annular portion 52 and a tubular portion 54 axially bent from the outer peripheral edge of the annular portion 52 and extending toward the cylinder block 14 . The mass ring 50 is attached to the base plate 20 by press-fitting the inner peripheral surface of the cylindrical portion 54 into the outer peripheral edge of the annular portion 23 . A friction plate (disc spring) 60 is arranged between the annular portion 23 of the base plate 20 and the annular portion 52 of the mass ring 50 .

In the crankshaft device 10 of the embodiment, the sensor plate (base plate 20 and toothed plate 30) and mass ring 50 are configured to function as a dynamic damper that reduces engine vibration. In this embodiment, the sensor plate and the mass ring 50 suppress the three-node bending resonance of the crankshaft 12 shown in FIG. (bending resonance frequency f1). Here, the vibration resonance frequency f0 of the sensor plate is determined by the spring constant kb of the base plate 20 in the tilt direction, the inertia mass Ma of the toothed plate 30 in the tilt direction, and the inertia mass Mc of the friction plate 60 in the tilt direction. and the inertial mass Md of the mass ring 50 in the tilt direction. Therefore, by adjusting the spring constant kb in the tilt direction of the base plate 20 by forming the adjustment hole 25 or the like and by adjusting the inertia mass Md in the tilt direction of the mass ring 50, the vibration resonance frequency can be relatively easily obtained. f0 can be matched to the bending resonance frequency f1. The inventors of the present application created a model of the crankshaft 12, the sensor plate, and the mass ring 50 and verified the effect of the dynamic damper function by performing an analysis using the created model. FIG. 6 is an explanatory diagram showing the relationship between the vibration acceleration and the frequency of each of the crankshaft devices of the example and the comparative example. In the figure, the solid line indicates the analysis result using the sensor plate of the comparative example, and the dashed-dotted line indicates the analysis result using the sensor plate of the example. The sensor plate of the comparative example has the same structure as the sensor plate (base plate 20 and toothed plate 30) of the example except that the mass ring 50 and the friction plate 60 are not provided. As shown in the figure, in the range of 2 kHz or less where radiated sound (vehicle noise) becomes a problem, the vibration resonance frequency of the sensor plate is made to match the three-node bending resonance frequency (1.55 kHz) of the crankshaft 12. It was confirmed that the vibration acceleration can be effectively suppressed by providing the sensor plate with a dynamic damper function.

Here, when the base plate 20 is positively vibrated in order to suppress the bending resonance of the crankshaft 12, as shown in FIG. When the detection element 40B is protruded and installed so that its detection surface faces the tooth tip of the toothed plate 30B, the gap between the tooth tip of the toothed plate 30B and the detection surface of the detection element 40B when the base plate 20 wobbles. may change significantly, resulting in detection failure. Therefore, in this embodiment, as shown in FIG. 7(b), the tip of the toothed plate 30 is axially protruded, and the detection surface of the detection element 40 is perpendicular to the tip of the toothed plate 30. It should be installed so that it faces the As a result, it is possible to suppress a change in the gap between the detection surface of the detection element 40 and the tooth portion 35 when the base plate 20 is deflected, thereby preventing detection failure.

In this embodiment, since the friction plate (disc spring) 60 is arranged between the annular portion 23 of the base plate 20 and the annular portion 52 of the mass ring 50, the friction damping effect of the friction plate 60 reduces the deflection of the base plate 20. can be kept within an acceptable range.

In the crankshaft device 10 of the embodiment described above, the sensor plate (the base plate 20 and the toothed plate 30) that rotates integrally with the crankshaft 12 of the engine, and the detection element 40 that detects the plurality of teeth 35 of the sensor plate. Prepare. In this crankshaft device 10, a mass ring 50 is provided on the outer peripheral portion of the sensor plate, and the sensor plate and the mass ring 50 are configured to have a dynamic damper function with a resonance frequency substantially matching the bending resonance frequency of the crankshaft 12. do. By providing the mass ring 50 on the outer peripheral portion of the sensor plate, the sensor plate and the mass ring 50 can function as a dynamic damper by utilizing the spring action of the sensor plate in the surface tilt direction. As a result, the crankshaft device 10 can suppress bending resonance of the crankshaft 12 and reduce vibration of the engine.

In the crankshaft device 10 of the embodiment, the friction plate 60 is provided between the annular portion 23 of the base plate 20 and the annular portion 52 of the mass ring 50 . However, if the deflection amount of the base plate 20 is within the allowable range, the friction plate 60 may not be provided as shown in the modified crankshaft device 110 of FIG.

In the crankshaft device 10 of the embodiment, the sensor plate is configured by connecting two members, the base plate 20 and the toothed plate 30 . However, as shown in the modified crankshaft device 210 of FIG. 9, the sensor plate 230 can also be constructed of a single member, depending on the required number of teeth and the required tooth tip length. As shown in FIG. 10, the plurality of tooth portions 235 are formed by forming a plurality of slits in the outer peripheral edge of the sensor plate 230 in the radial direction and bending the portions between the slits in the axial direction.

The correspondence relationship between the main elements of the embodiments and the main elements of the invention described in the column of Means for Solving the Problems will be described. In the embodiment, the crankshaft 12 corresponds to the "crankshaft", the base plate 20 and the toothed plate 30 correspond to the "sensor plate", the detection element 40 corresponds to the "detector", and the mass ring 50 corresponds to the " corresponding to "mass body".

Note that the correspondence relationship between the main elements of the examples and the main elements of the invention described in the column of Means for Solving the Problems is the Since it is an example for specifically explaining the mode for solving the problem, it does not limit the elements of the invention described in the column of the means for solving the problem. That is, the interpretation of the invention described in the column of Means to Solve the Problem should be made based on the description in that column, and the Examples are based on the description of the invention described in the column of Means to Solve the Problem. This is only a specific example.

Although the embodiments for carrying out the present invention have been described above, the present invention is not limited to such embodiments at all, and can be modified in various forms without departing from the scope of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the manufacturing industry of crankshaft devices.

Reference Signs List 10, 110, 210 crankshaft device, 12 crankshaft, 14 cylinder block, 16 oil seal, 20 base plate, 21 connecting portion, 22 connecting hole, 23 annular portion, 24 fixing hole, 25 adjusting hole, 30 toothed plate, 32 Annular part 33 Fixing hole 34 Cylindrical part 35,235 Tooth part 50 Mass ring 52 Annular part 54 Cylindrical part 60 Friction plate 230 Sensor plate.

Claims (1)

A crankshaft device comprising a rotation sensor including a sensor plate that rotates integrally with a crankshaft of an engine and a detector that detects teeth of the sensor plate,
Having a mass provided on the outer periphery of the sensor plate,
The sensor plate and the mass are configured to have a dynamic damper function with a resonance frequency substantially matching the bending resonance frequency of the crankshaft.
A crankshaft device characterized by:

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