JPH0740113Y2 - Crankshaft pulley - Google Patents

Description

[Detailed description of the device]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a crankshaft pulley which is attached to an end portion of a crankshaft of an engine and drives driven parts such as accessory parts. And a structure for reducing the transmission of torque fluctuations to the belt.

[Prior art]

A crankshaft pulley for transmitting the rotation of the engine to driven components such as an alternator and a water pump, an oil pump for driving a power steering, and an air conditioner compressor is attached to an end of a crankshaft of the engine. A pulley member provided with a groove for winding a belt (for example, a V belt) for driving an auxiliary machine is provided on the outer peripheral portion of the crankshaft pulley. FIG. 3 is a perspective sectional view specifically showing the structure of the V-belt. The V-belt 1 covers the upper surface and the lower surface of the rubber 2 with a cloth 3 and has a core wire 4 made of polyester fiber or the like inside.
It is configured by burying. The rubber 2, the cloth 3, and the core wire 4 are integrally formed by vulcanization adhesion. When such a V-belt is wound around a crankshaft pulley, the V-belt experiences tension fluctuations associated with engine rotation fluctuations and torque fluctuations. That is, in the engine, the rotational fluctuation due to the action of the explosion pressure in the combustion chamber and the torque fluctuation due to the action of the gas pressure in the combustion chamber and the inertial force of the piston, connecting rod, etc. repeatedly occur, and the angular velocity of the crankshaft varies. The rotation becomes unstable. When the rotation of the crankshaft becomes unstable due to fluctuations in rotation and torque, the tension of the V-belt wound around the crankshaft pulley increases when the rotational force increases (when the angular velocity increases), and the rotational force increases. It will decrease when becomes low (when the angular velocity becomes low). When the tension fluctuation occurs in this way, especially when the tension increases, a shearing force acts between the core wire embedded in the V-belt and the rubber,
This may induce peeling between the core wire and rubber. This is because there is a difference in elasticity (rigidity) between the rubber that comes into contact with the side surface of the groove formed in the pulley member of the crankshaft pulley and the core wire that is embedded inside. A speed difference is generated in the circumferential direction between the two, and a shearing force acts between them, and at the same time, the V-belt moves in the radial direction (inward) of the crankshaft pulley, which causes frictional resistance between the V-belt and the groove side surface. It occurs because a peeling force acts between the rubber and the core wire. In particular, this phenomenon is likely to occur in a low rotation range including idle rotation. Therefore, in order to reduce the transmission of rotation and torque fluctuations in the engine to the belt, there has been conventionally proposed a crankshaft pulley in which a pulley member having a groove on the outer peripheral portion is attached via an elastic member (for example, actual Kaisho 59-1316
42 publication). FIG. 4 and FIG. 5 are views showing the above-mentioned conventional crankshaft pulley, FIG. 4 is a plan view in which a part is broken away for explanation, and FIG. 5 is a line IV-IV of FIG. It is sectional drawing cut | disconnected along. In the crankshaft pulley 100, an inner elastic member 120, a vibrating ring 130, an outer elastic member 140 and a pulley member 150 are concentrically bonded and fitted to an outer peripheral surface of a hub 110 that constitutes a mounting portion with a crankshaft end portion. It is composed of The inner elastic member 120 and the vibrating ring 130 form a desired vibration system by appropriately setting the respective elastic coefficients (spring constants) and weights, and form a damper that reduces the torsional vibration of the crankshaft. As shown in FIG. 4, the outer elastic member 140 has a plurality of connecting portions 141 bonded to the outer peripheral surface 131 of the vibrating ring 130 and the inner peripheral surface 151 of the pulley member 150, and the outer peripheral surface of the vibrating ring. 131 and a plurality of protrusions 142 and 143 protruding from the inner peripheral surface 151 of the pulley member at predetermined intervals. A groove 153 is formed on the outer peripheral surface 152 of the pulley member 150, and a belt (not shown) is wound around the groove 153. According to the above-described conventional crankshaft pulley structure, the outer elastic member 140 has a plurality of protrusions 142 protruding at predetermined intervals.
Since it is composed of 143 and 143, the hub 110 and the pulley member 150 can be relatively moved in the circumferential direction even if torque fluctuations are transmitted to the hub 110 due to the rotation of the engine, and rotation, Direct transmission of torque fluctuations to the belt is suppressed. That is, even if the rotational force of the crankshaft increases due to rotation and torque fluctuations and the angular velocity of the hub 110 directly connected to the crankshaft end increases, the elastic force of the outer elastic member 140 absorbs the change in the angular velocity of the hub 110. And pulley member 150
The change in the angular velocity of is small, and the increase in the rotational force acting on the belt is reduced. Therefore, since the tensile force acting on the belt is reduced, the speed difference in the circumferential direction between the rubber and the core wire forming the belt is reduced, and the action of the shearing force between them is reduced. Therefore, the peeling of the rubber and the core wire is suppressed, and the durability of the belt can be improved.

[Problems to be solved by the device]

However, in the conventional structure in which the pulley member is attached via the elastic member, a shock is generated when the vibration ring 130 and the pulley member 150 relatively move to the plurality of protrusions 142 and 143 forming the outer elastic member 140. Since the structure exerts a force, the projections 142 and 143 may rub due to the impact, or in an extreme case, a crack may occur due to the impact. There was a problem of causing a decrease. That is, the crankshaft pulley having the conventional structure has a structure in which, when the vibration ring 130 and the pulley member 150 relatively move, the projections 142 and 143 collide with each other to regulate the amount of movement in the circumferential direction. It was Therefore, when there are large fluctuations in rotation and torque, each protrusion 14
The impact force when the 2 and 143 collide becomes large, and the impact force is repeatedly applied, so that the surface of the protrusion rubs or cracks occur at the bonding portion, and the vibration ring 130 and the pulley member 150
The ability to regulate the movement of the car will decline. Further, in the conventional structure, since the pulley member 150 is a single structure and is adhered to the vibration ring 130 via the outer elastic member 140, the vibration ring 130 and the pulley member 150 are rotated and torque-varied. If a relative movement occurs between them, deformation will occur over the entire area of the outer elastic member 140, and a load such as shearing force will continue to act on the entire area of the outer elastic member 140 during the rotation of the engine. And the durability was lowered due to settling. Further, since the pulley member 150 is restricted from moving in the radial direction, when the belt moves in the radial direction (inwardly) when tension fluctuations occur, the friction resistance of the side surface of the groove 153 causes the belt rubber and the core wire to move. The peeling force will be applied during this period. Therefore, the durability of the belt cannot be improved sufficiently. Therefore, according to the present invention, it is possible to improve the durability of the belt by suppressing the fluctuation of the tension of the belt due to the fluctuation of the rotation and the torque, and to improve the durability of the elastic member provided for suppressing the fluctuation of the tension. To aim.

[Means for solving problems]

Therefore, the present invention is characterized in that the structure of the contact portion with the belt and the formation position of the elastic member are changed in order to solve the above problems. Specifically, referring to FIGS. 1 and 2 of the present invention as an example, a crankshaft pulley (for transmitting engine rotation to a driven component) is provided at an end portion (21) of the crankshaft (20). 10) is installed. The hub (3 that composes this crankshaft pulley (10)
A pulley member (50) is fitted around the outer periphery of (0),
A groove (51) for winding the belt (1) for driving the auxiliary machine is formed on the surface of the pulley member (50). Elastic members (60) are adhered to both side surfaces (51a and 51b) of the groove (51), and contact surfaces with the belt (1) are formed on the surfaces at predetermined intervals in the circumferential direction. A plurality of contact members (70) are attached. And, in the joint between the contact members (70) adjacent to each other in the circumferential direction, so that the surface thereof is at the same level as the contact surface of the contact member (70),
The elastic member (60) is provided in a so-called flush state.

[Action]

When the angular velocity of the crankshaft pulley (10) changes with the rotation and torque fluctuations of the engine, a tensile force acts in a direction to increase the tension of the wound belt (1). A contact member (70) forming a contact surface when a tensile force is applied.
The contact member (70) relatively moves in the circumferential direction and the radial direction by the elastic force of the elastic member (60) inserted between the groove (51) and the groove (51). The relative movement of the contact member (70) in the circumferential direction together with the belt (1) reduces the shearing force acting on the belt (1). Further, the contact member (70) sinks in the radial direction together with the belt (1), so that the peeling force acting on the belt (1) is reduced. Since the contact member (70) is composed of a plurality of members in the circumferential direction of the pulley, the elastic member (60) that deforms when the tension increases is limited to only the contact region with the belt (1). Then, the elastic member (6) is provided at the joint between the plurality of contact members (70) arranged at a predetermined interval in the circumferential direction.
0) is filled to the same height as the contact surface, so the contact member (70) does not tilt when it is displaced in the circumferential direction, so only the circumferential and radial compressive forces act and the radial direction The generation of shearing force is suppressed.

【Example】

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing a crankshaft pulley according to an embodiment of the present invention. FIG. 1 is a plan view with a partially broken section for explanation, and FIG. 2 is FIG. It is sectional drawing cut | disconnected along the II line of FIG. Crankshaft pulley 10 is the end of crankshaft 20
A pulley member (50) is concentrically bonded and fitted to an outer peripheral portion of a hub (30) having a boss (31) to be fitted into the hub (21) via a damper rubber (40). The damper rubber 40 and the pulley member 50 are integrally assembled, for example, by means such as vulcanization adhesion and press fitting. A groove 51 around which the V-belt 1 is wound is formed on the circumference of the pulley member 50.
Are formed. On both side surfaces 51a and 51b of the groove 51, a contact member 70 constituting a contact surface with the V-belt 1 is attached via an elastic member 60. The contact member 70 is integrally molded with the elastic member 60 by vulcanization adhesion, for example. The elastic member 60 is provided over the entire circumference of the groove 51. As shown in FIG. 1, a plurality of contact members 70 are provided side by side at predetermined intervals in the circumferential direction, each of which is individually movable. ,
The elastic member 60 is provided in a so-called flush state so as to be at the same level as the contact surface of the contact member 70. The operation of this embodiment having the above configuration will be described. By winding the V-belt 1 around the groove 51, the rubber side surface of the V-belt 1 is pressed against the contact member 70, and slippage of the crankshaft pulley 10 in the circumferential direction is suppressed. Therefore, the rotation of the engine is transmitted to the V-belt 1 and driven parts such as an alternator and a compressor attached thereto are driven. The crankshaft 20 causes so-called torsional vibration during rotation, and this torsional vibration is applied to the V-belt 1 at this portion by the damper rubber 40 and the pulley member 50 provided on the outer peripheral portion of the hub 30 forming a kind of vibration system. The vibration transmission is absorbed. Further, during the rotation of the engine, so-called rotational fluctuation and torque fluctuation in which the rotational angular velocity changes due to the action of the explosion pressure and gas pressure in the combustion chamber and the inertial force associated with the rotation of the piston, connecting rod, etc. occur. Since the rotation and torque fluctuations are transmitted to the crankshaft pulley 10 attached to the crankshaft end 21, the angular velocity of the crankshaft pulley 10 also changes. When the angular velocity of the crankshaft pulley 10 fluctuates due to fluctuations in rotation and torque, a tensile force corresponding to the fluctuation in angular velocity acts on the V-belt 1 wound around the groove 51 of the pulley member 50, causing tension fluctuations. The tension of the V-belt 1 increases when the angular velocity increases, and decreases when the angular velocity decreases. When tension fluctuations occur in this way, especially when the tension increases, shearing force acts on the V-belt 1 in the circumferential direction of the crankshaft pulley 10, but the V-belt 1 is supported by the elastic member 60. Since it is in contact with the contact member 70,
The contact member 70 also moves in the circumferential direction (the direction in which the tensile force acts) according to the displacement of the belt 1. At the same time, the V-belt 1 is pressed in the radial direction of the crankshaft pulley 10. Since the elastic member 60 is compressed by the action of the pressing force in the radial direction, the V-belt 1 moves in the radial direction (inward) together with the contact member 70. In this way, the contact member 70 is V-shaped in the circumferential direction and the radial direction.
By moving according to the displacement of the belt 1, the speed difference between the rubber and the core wire becomes small, and the frictional resistance between the V belt 1 and the groove side surfaces 51a, 51b becomes small, so that the shear acting on the V belt 1 is reduced. The force and peel force will be reduced. In particular, since the joint between the contact members 70 is filled with the elastic member 60 so as to be flush with each other, tilting of the contact member 70 is suppressed. Therefore, peeling between the rubber and the core wire forming the V-belt 1 is suppressed, and the durability of the V-belt 1 can be improved. Further, in the present embodiment, since a plurality of contact members 70 are provided at predetermined intervals in the circumferential direction, the contact member in the portion not in contact with the V-belt 1 is circumferentially and radially oriented. Movement does not occur. That is, the elastic member 60 does not deform. Therefore, the elastic member 60 in the non-contact portion has a compressive force,
The shearing force does not act together, and the elastic member 60 receives the compressive force and the shearing force only in the portion in contact with the V belt 1. Therefore, the load acting on the elastic member 60 can be reduced, the fatigue of the elastic member 60 can be suppressed during long-term use, and the durability can be improved. Furthermore, when the tension of the V-belt 1 increases, a bending force acts in the direction perpendicular to the axis of the crankshaft 20, bending the crankshaft 20 and eccentric the crankshaft pulley 10. According to the example, due to the elasticity of the elastic member 60, the V-belt 1 and the contact member
Since the 70 can move in the radial direction, the eccentricity of the entire crankshaft pulley 10 and the crankshaft
Curvature of 20 can be suppressed. The specific embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and various embodiments are included within the scope of the claims of the utility model. For example, the contact member may have a structure in which a plurality of contact members are provided side by side at predetermined intervals in the circumferential direction, and the contact member is an integral structural member formed from one end to the other end of the groove side surface, and the elastic member is a gap between the contact member and the groove. It is also possible to have a structure in which it is filled in and then vulcanized and bonded. With the above structure, since the elastic member is filled between the contact member and the groove bottom surface, it is possible to prevent the contact member from extremely moving in the radial direction of the pulley, and the action of the shearing force of the elastic member in the radial direction. Therefore, the durability of the elastic member can be further improved.

[Effect of device]

As described above, according to the present invention, when the angular velocity of the crankshaft fluctuates due to the fluctuation of rotation and the torque and the tension of the V-belt fluctuates, the contact member and the elastic member are displaced in accordance with the displacement of the V-belt. Therefore, the shearing force acting on the V-belt in the circumferential direction of the pulley and the peeling force in the radial direction are reduced, and the peeling between the rubber and the core wire forming the V-belt is suppressed. Therefore, the durability of the V-belt can be improved over long-term use. Further, since the elastic member is simply interposed between the contact member and the groove formed in the pulley member and has no structure for receiving an impact, the durability does not deteriorate due to wear or cracks. Further, a plurality of contact members are provided side by side at predetermined intervals along the circumferential direction of the pulley, and the joint between the contact members adjacent in the circumferential direction is filled with an elastic member flush with the surface of the contact member. Therefore, the action of the compressive force and the shearing force on the elastic member is limited to only the portion in contact with the V belt. Therefore, the load acting on the elastic member can be reduced, and the durability of the elastic member can be prevented from decreasing due to settling or the like.

[Brief description of drawings]

FIGS. 1 and 2 are views showing a crankshaft pulley according to an embodiment of the present invention, FIG. 1 is a plan view with a partially broken section for explanation, and FIG. 2 is FIG. FIG. 3 is a sectional view taken along line I-I of FIG. 3, FIG. 3 is a perspective sectional view specifically showing the structure of the V belt, and FIGS. 4 and 5 are views showing the conventional crankshaft pulleys. FIG. 4 is a plan view in which a part is broken away for the sake of explanation, and FIG. 5 is a sectional view taken along line IV-IV in FIG. 1 …… Belt (V belt) 2 …… Rubber 3 …… Cloth 4 …… Core wire 10 …… Crankshaft pulley 20 …… Crankshaft 21 …… Crankshaft end 30 …… Hub 50 …… Pulley member 51 …… Grooves 51a, 51b …… Groove side surface 60 …… Elastic member 70 …… Contact member

Claims (1)

[Scope of utility model registration request] 1. A crankshaft pulley mounted on an end of a crankshaft for transmitting engine rotation to a driven component through a belt, wherein a groove around which a belt for driving an auxiliary machine is wound is formed on an outer peripheral portion of a hub. A plurality of contact members that form contact surfaces with the belt are held at predetermined intervals in the circumferential direction on both inner side surfaces of the groove of the pulley member, and While being attached via an elastic member,
A crankshaft pulley in which a joint between circumferentially adjacent contact members is filled with an elastic member such that the surface of the contact member is flush with the contact surface of the contact member with the belt.