JP5146391B2 - Pulley - Google Patents

Description

  The present invention relates to a pulley attached to a crankshaft or the like of an engine (internal combustion engine) mounted on a vehicle or the like.

  An engine mounted on a vehicle or the like includes a piston that is housed in a cylinder block that constitutes each cylinder so as to be reciprocally movable, and each piston is connected to a crankshaft that is an output shaft via a connecting rod. ing. A cylinder head is provided at the upper end of the cylinder block, and a combustion chamber is formed between the cylinder head and each piston. The piston reciprocates due to the combustion / explosion of the air-fuel mixture in the combustion chamber of each cylinder, and the reciprocating motion of the piston is converted into rotation of the crankshaft by the connecting rod.

  The engine is provided with various accessories such as a water pump, an alternator, a power steering pump, and an air conditioner compressor. Pulleys are attached to the rotation shafts of these auxiliary machines. A belt is wound around each auxiliary machine pulley and a crank pulley attached to the crankshaft of the engine, and the pulleys are compensated according to the rotation of the crankshaft. Belt transmission devices that drive machinery are widely used.

  The engine is also provided with a crank angle detection device that detects the rotation angle (crank angle) of the crankshaft. The crank angle detection device includes, for example, a sensor plate (rotation angle detection rotor) attached to the crankshaft, and a crank angle sensor (for example, an electromagnetic pickup sensor) disposed to face the sensor plate. The sensor plate is formed with a plurality of teeth (projections) formed at equal angles along the rotation direction of the crankshaft and a missing tooth portion lacking the same teeth.

  Detection of the crank angle by such a crank angle detection device is performed as follows. When the sensor plate rotates with the rotation of the crankshaft, a pulse signal is output from the crank angle sensor in accordance with the passage of the teeth each time the teeth pass near the crank angle sensor. The number of pulse signals output from the crank angle sensor after the output of the reference position signal is made the signal output from the crank angle sensor when the toothless portion passes in the vicinity of the crank angle sensor. The crank angle is detected on the basis of the value of the counter that counts.

  The sensor plate is attached to, for example, a crankshaft between a crank pulley (hereinafter simply referred to as “pulley”) disposed at an end portion (end portion on the engine front side) of the crankshaft and a timing sprocket. In addition, the sensor plate is arranged outside the engine in consideration of the fact that the detection accuracy of the crank angle is improved as the sensor plate becomes larger (larger diameter) and the workability of the adjustment operation of the crank angle detection device is taken into consideration. In some cases.

  As a technique for arranging the sensor plate outside the engine, there is one described in Patent Document 1 below. In the technique described in Patent Document 1, a sensing plate (corresponding to a sensor plate) is integrally fitted and attached to the outer peripheral portion of the crank pulley, thereby exposing the sensing plate to the outside of the engine.

  As a technique related to the sensor plate, in Patent Document 2, a signal plate (sensor plate) and a torsional timing belt pulley are used, and the cylindrical part of the signal plate is press-fitted and fixed to the cylindrical part of the torsional timing belt pulley. Thus, a structure in which the signal plate and the torsional timing belt pulley are integrated is described.

JP 2000-073813 A JP-A-8-135478 JP 2008-169730 A Japanese Patent Laid-Open No. 2000-126838

  By the way, in the structures described in Patent Documents 1 and 2, the pulley and the sensor plate, which are separate parts, are assembled by fitting, press-fitting, and the like. In some cases, the shape accuracy of the projections is lowered, and the accuracy of detecting the crank angle cannot be ensured.

  In addition, in the structure which assembles | attaches the pulley and sensor plate of another component, the number of parts and an assembly man-hour increase, and there also exists a subject that manufacturing cost becomes high.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a pulley having a sensor plate with good crank angle detection accuracy.

According to the present invention, in a pulley made of sheet metal having a cylindrical belt hook portion having a belt groove formed on the outer peripheral surface, a sensor plate having a plurality of teeth on the outer periphery is provided as a guide portion (ear portion) of the belt hook portion. A technical feature is that the sensor plate is integrally formed and each tooth of the sensor plate is formed in a curved shape curved in a direction parallel to the pulley rotation center .

  Thus, by providing the sensor plate integrally with the guide portion (ear portion) of the belt hanging portion, it is possible to ensure the accuracy of the shape of the teeth of the sensor plate and the coaxiality between the pulley and the sensor plate. The crank angle detection accuracy can be increased. Also, by providing a sensor plate integrally on the pulley guide, manufacturing costs and assembly man-hours are reduced compared to a structure in which a pulley and a sensor plate, which are separate parts, are assembled and integrated by fitting and press-fitting. Can be achieved.

  Here, when the sensor plate is integrally provided on the pulley, the sensor plate is externally arranged (externally attached), and therefore the teeth of the sensor plate (sensing part) are deformed by a collision with a stepping stone, etc. There is a concern that the detection accuracy may decrease.

Therefore, in the present invention, by a respective tooth curved shape is curved (sensing unit) in the pulley rotation center and parallel to the direction of the sensor plate, the section modulus of the tooth rigidity becomes higher increases, flying stones Even if it hits the teeth, the deformation of the teeth can be prevented.

In the pulley, each tooth of the sensor plate may be curved such that a central portion in the rotation direction protrudes to the front side as compared with both end portions.

In the pulley, a hub may be integrally provided on the belt hanging portion via a flange portion, and a crankshaft may be attached to the hub.

It is a perspective view which shows an example of a crank pulley. It is a front view of the crank pulley shown in FIG. It is XX sectional drawing of FIG. It is a figure which shows typically the state which attached the crank pulley of FIG. 1 to the crankshaft of the engine. It is a perspective view which shows the pulley of FIG. 1 in use condition. It is a perspective view which shows the other example of a crank pulley. It is sectional drawing of the tooth | gear of the sensor plate provided in the crank pulley of FIG. It is principal part sectional drawing which shows an example of the structure which prevents a deformation | transformation of the tooth | gear of the sensor plate provided in the crank pulley. It is a perspective view which shows another example of a crank pulley. It is sectional drawing of the tooth | gear of the sensor plate provided in the crank pulley of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1
An example of the pulley of the present invention will be described with reference to FIGS.

  As shown in FIG. 4, the crank pulley 1 of this example is attached to the end of the crankshaft 301 of the engine 300, and the rotational force of the crankshaft 301 is auxiliaries via a belt wound around the outer peripheral surface of the pulley. (For example, water pumps, alternators, power steering pumps, air conditioner compressors, etc.).

  Note that the crank pulley 1 is disposed on the side of the chain case 302 outside the engine 300.

  The crank pulley 1 is a sheet metal pulley obtained by processing a plate material such as a steel plate by press working or the like, and includes a pulley portion 2 and a sensor plate 3 to be described later, as shown in FIGS.

  The pulley portion 2 includes a cylindrical hub 21 and a cylindrical belt hooking portion 23 formed integrally with the hub 21 via a flange portion 22.

  A key groove 21 a extending in the axial direction is machined on the inner surface of the hub 21. A key (not shown) for determining the rotational positional relationship between the crankshaft 301 and the crank pulley 1 shown in FIG. 4 is inserted into the key groove 21a. The flange portion 22 has a plurality of holes 22a having a circular front shape.

  A plurality of V grooves 23a extending in the circumferential direction are formed on the outer peripheral surface of the belt hooking portion 23, and a belt 400 for power transmission is wound around these V grooves 23a (see FIG. 5).

  At both ends of the belt hooking portion 23 (both ends in the axial direction of the crank pulley 1), ear portions (guide portions) 23b and 23c for preventing belt detachment are formed.

  In the crank pulley 1 of this example, the sensor plate 3 is attached to the ear 23c on the side close to the chain case 302 of the engine 300 shown in FIG. 4 among the ears 23b, 23c at both ends of the belt hook 23. This is a technical feature of the present invention. The sensor plate 3 is provided with a plurality of teeth 3a and a missing tooth portion 3b (see FIG. 2) on the outer periphery thereof.

  The above crank pulley 1 is attached to the end of the crankshaft 301 of the engine 300 with a set bolt 310 as shown in FIG. In addition, although not shown, auxiliary machinery pulleys are attached to the respective rotation shafts of each auxiliary machinery (for example, a water pump, an alternator, a power steering pump, an air conditioner compressor, etc.). A belt transmission is configured in which a belt 400 is wound between the pulleys of the crank pulley 1 and the accessories are driven in accordance with the rotation of the engine 300 (rotation of the crankshaft 301).

  When removing the crank pulley 1 from the crankshaft 301, the set bolt 310 is loosened and removed while the rotation of the crank pulley 1 is fixed using the hole 22a of the flange portion 22, and then the hole 22a of the flange portion 22 is removed. The crank pulley 1 can be removed by a procedure in which a jig or the like is hooked on the periphery of the crankshaft and the crank pulley 1 is pulled out from the crankshaft 301.

  Further, as shown in FIG. 5, a crank angle sensor (for example, an electromagnetic pickup sensor) 500 is disposed on the side of the crank pulley 1 at a position facing each tooth 3a (missing tooth portion 3b) of the sensor plate 3. ing. The crank angle sensor 500 is attached to the wall of the chain case 302 of the engine 300. The sensor plate 3 and the crank angle sensor 500 constitute a crank angle detection device.

  The crank angle is detected by the crank angle detection device as follows. When the sensor plate 3 rotates along with the rotation of the crankshaft 301, each time the tooth (sensing unit) 3a of the sensor plate 3 passes in the vicinity of the crank angle sensor 500, the pulse signal is cranked in accordance with the passage of the tooth 3a. Output from the angle sensor 500. When the toothless portion 3b of the sensor plate 3 passes in the vicinity of the crank angle sensor 500, a signal output from the crank angle sensor 500 is used as a reference position signal, and the crank angle sensor is output after the output of the reference position signal. The crank angle can be detected based on a counter value obtained by counting the number of pulse signals output from 500.

  The above-described crank pulley 1 made of sheet metal shown in FIGS. 1 to 5 is a known manufacturing method (see, for example, Japanese Patent Laid-Open Nos. 2000-126838, 7-269678, and 7-236932). Can be manufactured by.

<Effect>
According to the crank pulley 1 of this example, since the sensor plate 3 is integrally provided on the ear 23c of the belt hook 23, the shape accuracy of the teeth 3a of the sensor plate 3, and the pulley 2 and the sensor plate 3 are provided. And the like can be ensured, and the crank angle detection accuracy can be improved. In addition, by providing a sensor plate integrally with the ear 23c of the pulley portion 2, compared to a structure in which a pulley and a sensor plate manufactured separately in a separate process are assembled and integrated by fitting and press-fitting. Thus, the manufacturing cost and the number of assembly steps can be reduced.

Embodiment 2
FIG. 6 is a perspective view showing another example of the crank pulley. FIG. 7 is a cross-sectional view of the teeth (sensing portion) of the sensor plate provided on the crank pulley. FIG. 7 is a cross-sectional view of the sensor plate teeth cut along a plane parallel to the pulley rotation center.

  This example is characterized in that the teeth 103a of the sensor plate 103 formed integrally with the crank pulley 101 are curved in a direction parallel to the pulley rotation center (the pulley front side). Other configurations are the same as those in [Embodiment 1].

  When the teeth 103a are curved in this way, the section modulus of the teeth 103a is increased and the rigidity is increased. Therefore, even if a stepping stone or the like hits the teeth 103a, the deformation of the teeth 103a can be prevented. This can prevent a decrease in crank angle detection accuracy.

  As another configuration for preventing deformation of the teeth of the sensor plate, ribs 320 that cover the teeth 3a of the sensor plate 3 may be provided on the wall 302a of the chain case 302 as shown in FIG. By adopting such a configuration, it is possible to prevent a stepping stone or the like from hitting the teeth 3a of the sensor plate 3 and to prevent deformation of the teeth 3a as the sensing unit. A decrease can be prevented. The rib 320 is preferably disposed so as to cover substantially the entire outer peripheral edge of the sensor plate 3 (excluding the portion where the crank angle sensor 500 is disposed).

Embodiment 3
FIG. 9 is a perspective view showing another example of the crank pulley. FIG. 10 is a cross-sectional view of the sensor plate teeth (sensing portion) provided on the crank pulley. FIG. 10 is a cross-sectional view of the sensor plate teeth cut along a plane parallel to the pulley rotation center.

  First, in the crank pulley 1 shown in FIGS. 1 to 5, the teeth (sensing part) 3 a of the sensor plate 3 has a flat plate shape, and the teeth 3 a. There is a concern that abnormal noise (wind noise) may be generated when the sensor plate 3 rotates with rotation (rotation of the crankshaft 301).

  In consideration of such points, in this example, as shown in FIGS. 9 and 10, the pulley rotation direction side of each tooth 203a of the sensor plate 203 integrally formed with the crank pulley 201 (air (wind) during pulley rotation) The shape of the part that hits is streamlined. With such a structure, wind noise generated when the sensor plate 203 rotates can be reduced. In this example, the configuration other than the shape of each tooth 203a of the sensor plate 203 is the same as [Embodiment 1] described above.

  The present invention is also applicable to pulleys other than crank pulleys.

  The present invention can be used for a pulley attached to a crankshaft or the like of an engine (internal combustion engine) mounted on a vehicle or the like.

DESCRIPTION OF SYMBOLS 1 Crank pulley 2 Pulley part 21 Hub 22 Flange part 23 Belt hook part 23a V groove 23b, 23c Ear | edge part (guide part)
3 Sensor plate 3a Teeth (Sensing part)
3b Missing tooth part 300 Engine 300a Chain case 301 Crankshaft

Claims (3)

A pulley made of sheet metal provided with a cylindrical belt hanging portion having a belt groove formed on the outer peripheral surface,
A sensor plate having a plurality of teeth on the outer periphery is provided integrally with the guide portion of the belt hanging portion ,
Each of the teeth of the sensor plate is formed in a curved shape curved in a direction parallel to the pulley rotation center . The pulley according to claim 1, wherein
Each of the teeth of the sensor plate is curved so that a central portion in the rotation direction protrudes to the front side as compared with both end portions . The pulley according to claim 1 or 2 ,
A hub is integrally provided on the belt hanging portion via a flange portion,
A pulley having a crankshaft attached to the hub .

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